ScienceWeek

SCIENCE-WEEK

A Weekly Email Digest of the News of Science

A journal devoted to the improvement of communication
between the scientific disciplines, and between scientists,
science educators, and science policy makers.

June 11, 1999 -- Vol. 3 Number 24

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Cosmology is one of those aggravating sciences in which
reasonable assumptions often lead to unreasonable results.
-- Anonymous

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Contents of This Issue:

1. Academia vs. Industry: A US$1 Billion Hormone Patent Battle
2. Cosmology: On the Epoch of Galaxy Formation
3. Earth Science: On Mantle Plumes and Mountains
4. On the Evolutionary Tree of Life
5. Neurobiology: Dendrite Morphology Induced by Synaptic Activity
6. Medical Science: Deaths Related to Liposuction

In Focus: On the Evolution of the Vertebrate Brain

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1. ACADEMIA VS. INDUSTRY: A US$1 BILLION HORMONE PATENT BATTLE
One day in the future, synthetic biochemical assembly systems
(synthetic "ribosomes"), in accordance with laboratory controlled
instruction sets, will synthesize any protein on demand. At the
present time, however, the best we can do is use the natural
biochemical machinery of living organisms to achieve such
synthesis, a complicated laboratory process involving the
insertion of one or more appropriate DNA sequences into the
genome of a capable host organism, usually a bacterium, with the
host bacterium cultured in large bacterial populations that
produce the desired protein in useful quantity. Certain
synthesized proteins can be of extreme monetary value, among the
most valuable substances known, with sales in the billions of
dollars, and such is the case with the protein called "human
growth hormone" (*somatotropin), which is used to treat various
growth disorders in children. The first round in a legal battle
concerning the patent rights to a synthetic human growth hormone
has just been completed, and the details of the conflict are an
instructive illustration of how the push for huge profits from
research in molecular biology may be corrupting the practice of
basic science by both industrial and academic researchers. The
elements of this story are as follows:
     1) In the mid 1970s, a young German researcher named Peter
H. Seeburg, bearing a German fellowship, arrived in the US as a
postdoctoral fellow in the laboratory of Howard Goodman at the
University of California San Francisco. During the next few
years, Seeburg, another postdoctoral fellow (John Shine), and
laboratory head Goodman succeeded in cloning the gene for human
growth hormone, and they and the University of California San
Francisco applied for a patent for a DNA sequence for the gene.
     2) Seeburg and his laboratory head, Goodman, evidently had a
falling out, and Seeburg (according to himself) could continue
his research on the hormone expression process only at night and
without support from Goodman.
     3) Denied a position by the university, Seeburg went to work
for a recently formed company in San Francisco named Genentech,
now one of the leading biotechnology companies in the world. (One
of the founders of Genentech was Herbert Boyer, a former
molecular biologist at the University of California San
Francisco.)
     4) At Genentech, Seeburg worked with a postdoctoral
researcher named David V. Goeddel and others to replicate and
extend the human growth hormone work, "aiming to get a complete
sequence that could be put in bacteria for mass production." The
work at Genentech, however, was apparently frustrated by poor
source tissue and many failures.
     5) On New Year's Eve, December 31, 1978, at approximately 11
p.m., Seeburg and a Genentech colleague surreptitiously went to
the Goodman laboratory where Seeburg had previously worked and
took a number of samples, including an essential cloned partial
human growth hormone DNA sequence.
     6) According to Seeburg, the material removed from Goodman's
laboratory was used to complete the Genentech human growth
hormone project by himself and David Goeddel. Seeburg has
testified under oath that he and Goeddel made a secret agreement
to conceal the use of the University of California DNA material
in their Genentech developmental research.
     7) In 1979, Seeburg and his colleagues at Genentech
published the results of the Genentech project in a paper in the
journal _Nature_. Seeburg has recently testified under oath that
in this paper, in order to hide the source of an important part
of the genetic engineering process (the material taken from
Goodman's laboratory), a false DNA entity (a plasmid) was
indicated in the paper, an entity that never existed.
     8) In 1979, after learning of the removal of DNA material
from the Goodman laboratory, the University of California San
Francisco made repeated requests for return of the material,
until finally, in 1980, Genentech paid the university US$2
million for it.
     9) In 1982, the University of California, together with
Goodman, Seeburg, and Shine, was awarded a patent for the DNA
sequence of human growth hormone detailed by the Goodman
laboratory researchers. That same year, Genentech was awarded a
patent for the more complete sequence of human growth hormone and
the genetic engineering process for its biosynthesis. Genetically
engineered human growth hormone was the first "big" product for
Genentech, and the company's valuation increased enormously. The
product was named "Protropin", and since its approval in 1985,
Genentech sales of the drug have amounted to US$2 billion.
     10) In 1990, the University of California San Francisco
brought suit against Genentech for infringement of the
university's patent for DNA for human growth hormone. The
university has been seeking US$400 million in back royalties and
interest, and has asked for triple damages in the amount of
US$1.2 billion because of alleged willful misconduct by
Genentech. The actual trial (before a jury) began only 6 weeks
ago.
     11) In April of 1999, in a completely separate litigation,
Genentech agreed to pay the US government US$50 million to settle
US Federal criminal charges that it had marketed human growth
hormone for unapproved uses from 1985 to 1994. In this
litigation, Genentech pleaded guilty to one criminal charge.
     12) On 27 and 28 May 1999, following reports of Seeburg's
testimony during the University of California-Genentech trial
(Seeburg testified for the University of California and against
Genentech), David V. Goeddel and 6 other co-authors of the 1979
paper published letters in both _Nature_ and _Science_ denying
that any data in that paper had been fabricated. Goeddel also
insists that he and Seeburg never had any "secret" agreement
concerning the material taken from Goodman's laboratory.
     13) On 2 June 1999, after 6 days of deliberation, the jury
in the University of California San Francisco-Genentech case
deadlocked in a vote of 8 to 1 in favor of the university. The
university will apparently request a new trial.
     14) Peter H. Seeburg is presently in the Department of
Molecular Neuroscience, Max Planck Institute for Medical
Research, Heidelberg DE. The University of California San
Francisco human growth hormone patent has been licensed to Eli
Lilly & Co. As co-inventor, Seeburg will receive approximately 10
percent of any royalties, including the same percentage of any
patent infringement award.
     15) David Goeddel is presently founder and chief executive
of the molecular biology company Tularik Inc., of San Francisco,
US. He has testified for Genentech in this case.
     16) The current cash reserve of Genentech has been stated as
US$1.7 billion.
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Editor's note: For background material in the general area, see
the SW Focus Report "Science and Commerce in Conflict" available
at URL [http://www.scienceweek.com/swfr025.htm].
-----------
Andrew Pollack: Genentech trial on patent ends with jury
deadlocked.
(New York Times 3 Jun 99)
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Letters: UC-Genentech trial.
(Letters by D.Henner et al and by P.H. Seeburg)
(Science 28 May 99 284:1465)
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Rex Dalton: Charges fly in $1bn hormone patent battle.
(Nature 27 May 99 399:289)
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Eliot Marshall: Startling revelations in UC-Genentech Battle
(Science 7 May 99 284:883)
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Text Notes:
... ... *somatotropin: This protein hormone is secreted by the
anterior lobe of the pituitary. It promotes body growth, fat
mobilization, and inhibition of glucose utilization. It produces
diabetes when present in excess; a deficiency of the hormone is
associated with various types of dwarfism. The protein has
variants, all of which consist of approximately 200 amino acid
residues per chain.
-------------------
Summary & Notes by SCIENCE-WEEK [http://scienceweek.com] 11Jun99


2. COSMOLOGY: ON THE EPOCH OF GALAXY FORMATION
One of the central problems in cosmology is to understand the
entire history of galaxies, from their first gravitational
collapse in the early Universe to the rich variety and detail
observed in the present-day Universe. ... ... Charles C. Steidel
(California Institute of Technology, US) presents a review of
current research concerning galaxy formation, the author making
the following points:
     1) There are essentially two approaches to the problem of
the evolution of galaxies. The first approach is the classical
approach in which observations of the chemical content,
kinematics, and spatial distribution of stars in our Galaxy and
in nearby galaxies are used to infer the sequence of events that
produced what we see today. The second approach to the evolution
of galaxies uses samples of galaxies at progressively larger
distances as snapshots of the increasingly remote past. One
advantage of the second approach is that it may be possible to
observe directly the evolution of galaxy populations and actually
catch incipient galaxies in the process of formation. Relevant to
the second approach is the fact that it is now possible to
observe galaxies over greater than 90 percent of the age of the
Universe, as a result of new telescopes, new instruments, and new
techniques.
     2) In the 1960s and 1970s, there emerged the view that large
galaxies formed through a rapid gravitational collapse that would
have resulted in huge bursts of star formation at early epochs,
leaving behind galaxies that had rapidly exhausted their fuel to
age quietly until the present, such galaxies appearing now as
large collections of old *red stars, e.g., *elliptical galaxies
and the central bulges of *spiral galaxies. This formation
scenario is often referred to as "monolithic collapse".
     3) The modern theoretical framework for understanding galaxy
formation can be said to date back only approximately 20 years.
The modern approach, rather than working backwards from our
present understanding of stellar evolution and stellar dynamics,
works forward from prescribed initial conditions by using the
physics of structure formation. The modern approach attempts to
understand galaxy formation as a natural consequence of the
growth of mass fluctuations resulting from gravitational
instability.
     4) Theoretical arguments and numerous observations suggest
that initial conditions imposed in the early Universe, together
with gravitational instability, would result in a universe in
which the smallest mass fluctuations collapse first and merge
into progressively larger structures as time goes on. The
theoretical models currently favored are all variations on this
general framework, which is often called "hierarchical structure
formation". The basic premise is that *dark matter dominates the
overall mass density, interacts only gravitationally with normal
matter, but ultimately dictates the underlying structure of all
matter.
     5) Recent observational progress has largely involved making
the early stages of the Universe less mysterious by filling in
some of the glaring gaps in empirical information concerning the
earliest observable galaxies. In general, what has emerged over
the last 3 years is an outline of overall energy production by
star formation for nearly the entire history of the Universe, the
ability to discern the detailed morphologies (shapes and sizes)
of the distant galaxies, and the demonstration of efficient
observational techniques that make feasible large-scale surveys
of galaxies in the distant Universe.
     6) The author concludes: "The health of general theoretical
ideas about galaxy formation is quite robust at present, although
the details are still very immature... The uncovering of the
universe of galaxies beyond the epoch that has been explored
already, and more detailed views of the currently accessible
epochs, will be made possible by the Next Generation Space
Telescope, a large infrared-optimized telescope planned for 2007
or 2008. The next decade promises to bring a literal avalanche of
data relevant to the question of galaxy formation. The challenge
will be to make sense of it all."
-----------
Editor's note: In addition to the background material below, see
the SW Focus Report "Astrophysics: Evolution of Galaxies"
available at URL [http://www.scienceweek.com/swfr039.htm].
-----------
Charles C. Steidel: Observing the epoch of galaxy formation.
(Proc. Natl. Acad. Sci. US 13 Apr 99 96:4232)
QY: Charles C. Steidel [ccs@astro.caltech.edu]
-----------
Text Notes:
... ... *red stars: In general, red stars have surface
temperatures between 2500 and 5000 degrees kelvin. Two types of
red stars are recognized: red dwarfs (mass 0.8 to 0.08 solar-
mass) and red giants (diameter 10 to 100 times the Sun). Red
dwarfs are the most common type of star and apparently the
longest lived. Red giants are apparently old stars that have
exhausted their core hydrogen fuel.
... ... *elliptical galaxies: These are galaxies that have no
disc component, the shape varying from almost circular to narrow
ellipses. The stars within elliptical galaxies are predominantly
old stars. Elliptical galaxies display the greatest variation in
mass, ranging down to extreme dwarf galaxies (approximately
10^(6) solar-mass).
... ... *spiral galaxies: A type of galaxy with bright arms of
stars, gas, and dust that extend in a spiral pattern from a
central hub. The arms of the spiral apparently contain young
stars, while the hub contains old stars.
... ... *dark matter: In general, in this context, the term "dark
matter" refers to material whose presence can be inferred from
its effects on the motions of stars and galaxies, but which
cannot be seen directly because it emits little or no radiation.
It is believed that at least 90 percent of the mass in the
Universe exists as some form or dark matter.
-------------------
Summary & Notes by SCIENCE-WEEK [http://scienceweek.com] 11Jun99
-------------------
Related Background:
ON THE EVOLUTION OF GALAXIES IN A CHANGING UNIVERSE
In a detailed review of research in this century concerning the
evolution of galaxies, Alan Dressler (Carnegie Observatories
Pasadena, US) makes the following points: 1) When the century
opened, most astronomers assumed the Universe was eternal and
basically changeless, its general structure immutable. In 1915,
with the publication of Einstein's general theory of relativity,
there were implications of the cosmic role of gravity, but these
implications were for the most part ignored. Indeed, even after
1924 and the proof by *Edwin Hubble (1889-1953) that the spiral
nebulae are other galaxies at vast distances, astronomers were
slow to recognize the implications of the new observations. 2)
The first big step in changing the view of the cosmos was the
construction by *George Ellery Hale (1868-1938) of the 100-inch
Hooker reflector on Mount Wilson (US), a project completed in
1918. This was the telescope used by Hubble and his colleagues to
reveal the large-scale organization of the Universe into
galaxies, the vast size of the Universe, and the expansion of the
Universe. *George Lemaitre (1894-1966) soon proposed that the
expansion of the Universe implied a dense explosive birth of the
Universe at a specific finite time in the past (the event that
came to be called the Big Bang). 3) An even greater telescope was
needed, and again George Hale led the way in the building of the
200-inch reflector on Palomar Mountain (US), that instrument
finally completed in 1948. The 200-inch telescope produced the
first observations of galaxy evolution -- the first evidence that
galaxies observed at high *redshift are unlike galaxies closer to
us in time. An even greater accomplishment of the 200-inch
telescope was a series of observations concerning the spectra of
*quasars, and the evidence for their immense distances and
luminosities. Theorists eventually proposed that quasars were
*black holes of 100 million solar-masses or more. It is now clear
that most galaxies with a central bulge, including our own
Galaxy, harbor massive black holes at their cores. 4) In 1961,
Allan Sandage published a landmark paper outlining the
possibility of testing cosmological models with the 200-inch
telescope, and over the next two decades Sandage devoted himself
to this project. Unfortunately, the underlying premise of the
project -- that the brightest galaxy in every galactic cluster
has about the same true luminosity -- was demonstrated by
*Beatrice Tinsley (1941-1981) to be untenable. 5) In the fall of
1977, at a Yale University (US) conference on the evolution of
galaxies, Harvey Butcher and Augustus Oemler presented their
evidence for relatively young star-forming galaxies. This
evidence, which implied strong galaxy evolution during relatively
recent cosmic time, met with controversy and skepticism. 6) In
the 1980s, observations by various groups proved that Butcher and
Oemler were correct, and it was now understood that these
relatively young galaxies were often producing new stars in huge
bursts. These bursting galaxies are evidently spirals with a more
disheveled appearance than is common today, and in their twisted
and distorted disks huge numbers of stars were recently born. 7)
During the past 2 years, among the most interesting results of
various observations with various instruments is the formulation
of the so-called Madau diagram (popularized by Piero Madau) that
plots the Universe-wide rate of star formation from early times
to today, spanning almost the whole history of the cosmos. The
rate of star formation apparently rose rapidly in the first few
billion years, the peak rate at about 5 or 6 billion years later
at redshifts of 1 to 2. (Our Sun apparently formed at a time
corresponding approximately to redshift = 0.5.) The author
concludes: "Our generations are fortunate to live to see one of
the great mysteries of where we came from in process of being
solved."
QY: Alan Dressler, Carnegie Observatories, Pasadena, Ca. US.
(Sky & Telescope October 1998) (Science-Week 11 Sep 98)
-------------------
Related Background:
... ... *Edwin Hubble (1889-1953): Hubble first studied law
before switching to astronomy at the age of 25. He began his work
at the Mount Wilson Observatory with the 100-inch telescope at
the age of 30. In 1941, at the age of 52, he tried to join the US
Army to fight the Nazis, but he was persuaded that he could do
more in war-related research. 
... ... *George Ellery Hale (1868-1938): Hale is best known for
his work building large-telescopes (and for obtaining the funds
for the Yerkes Observatory, named after the street-car magnate
Charles Tyson Yerkes), but already at the age of 21 he invented
the spectroheliograph, a device that made it possible to
photograph the light of a single spectral line of the sun, and he
made several ground-breaking observations with this instrument.
... ... *George Lemaitre (1894-1966): Lemaitre began his
professional life as a civil engineer, then at 21 he switched to
physics and mathematics. He also became a Roman Catholic priest
at the age of 22. After obtaining his PhD at the Massachusetts
Institute of Technology in 1927, he settled in Belgium as a
professor of astrophysics at the University of Louvain. At the
time of his death, he was president of the Pontifical Academy of
Sciences at Rome. Lemaitre's theoretical ideas concerning the
origin of the Universe were published in 1927, when he was 31,
but the paper was largely unnoticed until the astrophysicist
Arthur Eddington (1882-1944) called attention to it much later.
... ... *redshift: Redshift (symbol: z) is a lengthening of the
wavelengths of electromagnetic radiation from a source caused
either by the movement of the source (Doppler effect) or by the
expansion of the universe (cosmological redshift). Redshift is
defined as the change in wavelength of a particular spectral line
divided by the unshifted wavelength of that line. Large redshifts
imply large radial velocities (which imply large distances,
according to current cosmological theory), but at redshifts
greater than about 0.2 there is a relativistic divergence from a
linear relation. A redshift of 4.0 corresponds to an object
receding with a radial velocity 92% that of the velocity of
light. The largest astrophysical redshifts so far observed are of
the order of z = 4.9.
... ... *quasars: (quasi-stellar objects). Extremely luminous
sources radiating energy over the entire spectrum from x-rays to
radio waves, and which are apparently the oldest and most distant
objects in the universe.
... ... *black holes: If the terminal stages of star death leave
a remnant star mass greater than 3 solar-masses, the ultimate
gravitational collapse will produce a black hole, a relativistic
singularity. A black hole is a localized region of space from
which neither matter nor radiation can escape. The "trapping"
occurs because the requisite escape velocity, which can be
calculated from the relevant equations, exceeds the velocity of
light and is therefore unattainable. Another view of a black hole
is that it is a mass that has collapsed to such a small volume
that its gravity prevents the escape of all radiation. Space and
time essentially have no meaning in a black hole. The boundary of
the black hole is called the "event horizon", because any event
within the boundary is invisible outside, the invisibility
resulting from the fact that no radiation can escape to be
detected. The radius of the black hole depends upon how much
matter has fallen into the region; it is called the "Schwarzchild
radius", and it is usually a few kilometers. However, massive
black holes are possible and are thought to be the source of
quasars. If quasars indeed involve black holes, the radiation is
from material just outside the black hole, and not from anything
within it. Nothing inside a black hole can get out of it.
... ... *Beatrice Tinsley (1941-1981): During her short life,
Tinsley managed to be a force in astronomy from her first entry
into the field. At the age of 25, an unknown graduate student at
the University of Texas, she rose before an audience about to
hear Allan Sandage and publicly challenged his idea that giant
elliptical galaxies exhibited luminosities constant enough to be
used as "standard candles" to estimate distances. She proved her
point by the age of 36, and the variability of galaxy
luminosities became the consensus view. It was Tinsley who co-
hosted the 1977 Yale conference that set the course of galaxy-
evolution studies. She died 4 years later of cancer. Near the
end, she wrote the following: "Let me be like Bach, creating
fugues; till suddenly the pen will move no more."
-------------------
Summary & Notes by SCIENCE-WEEK [http://scienceweek.com] 11Sep98
-------------------
Related Background:
ON THE AGGREGATION OF YOUNG GALAXIES IN A DARK-MATTER UNIVERSE
The term "semi-analytic modeling" refers to a quantitative
modeling procedure in which empirical data are used in places to
fix the values of parameters or functions, rather than deriving
these from theoretical principles. N-body simulations, which
usually require extraordinary computational resources, are
simulations involving calculations of interactions of a large
population of entities. "Dark matter", which is thought to
comprise as much as 90% or more of the mass of the universe, is
undetectable except by gravitational effects, and "cold dark
matter" refers to dark matter particles created with low velocity
dispersions in the early universe. At the present time, computer
simulations and empirical observations of galaxy clustering favor
the idea that most dark matter in the universe is cold dark
matter. ... ... Governato et al (7 authors at 3 installations, UK
DK US) report the use of a combination of theoretical techniques
(semianalytic modeling and n-body simulations) to show that large
concentrations of young galaxies (i.e., galaxies in existence
when the universe was one-tenth of its current age) should be
quite common in a universe dominated by cold dark matter, and
that such galaxy concentrations are the progenitors of the rich
galaxy clusters seen today. The authors suggest these clustering
properties of primeval galaxies will be compared with data
collected in the near future, and that the comparison will be a
test of our current understanding of galaxy formation within the
framework of a universe dominated by cold dark matter.
QY: C.S. Frenk [c.s.frenk@durham.ac.uk]
(Nature 26 Mar 98) (Science-Week 10 Apr 98)


3. EARTH SCIENCE: ON MANTLE PLUMES AND MOUNTAINS
Seismic studies indicate the interior of the Earth consists of
three parts: a metallic core, a dense rocky mantle, and a thin
low-density crust. The central part of the core is solid, but the
outer part of the core is evidently liquid. The mantle, the layer
of dense rock and metal oxides between the molten part of the
core and the surface, has plastic properties (i.e., it is a solid
capable of flow under pressure). The term "lithosphere" refers to
the outer layer of the Earth, comprising the crust and upper
mantle, and extending to a depth of 50 to 70 kilometers. Plate
tectonics is the current consensus theory that the Earth's
lithosphere is broken into fairly rigid plates, seven major
plates and many smaller plates, and that convection within the
underlying less rigid "asthenosphere" causes the plates (and the
associated continents and crust) to move relative to each other,
the movement manifested in continental drift and sea-floor
spreading. The term "hot spot" (also, hotspot) refers to a
relatively long-lasting center of surface volcanism and locally
high heat flow, and about 40 locations are now so labelled. Most
hot spots are in ocean basins, located at points where the
lithosphere has apparently upswelled, elevating the denser mantle
material and creating mass anomalies. "Mantle plumes" are thin
vertical conduits of molten rock material from the core-mantle
boundary to the crust. The term "subduction" refers to the
process of underthrusting of the edge of an oceanic plate into
the mantle underlying an adjacent plate.
... ... J.B. Murphy et al (4 authors at 3 installation, CA US)
present a review of current studies concerning the relation
between mantle plumes and mountain building (orogeny;
orogenesis), the authors making the following points:
     1) Theories of mountain building were revolutionized in the
1960s by plate tectonic theory. The horizontal motions of rigid
plates of material above a pliable mantle helped explain the
creation and destruction of oceans, the generation of mountain
belts and sedimentary basins, the distribution of volcanic and
earthquake activity, and the locations of ore, oil, and gas
deposits. But plate-tectonic theorists have had difficulty
accounting for many of the geological details of southwestern
North America, including the uplifting of the Rocky Mountains,
the extent of the Basin and Range region of Nevada, Utah, and
Arizona, and the extensive volcanic deposits of the Columbia
Plateau.
     2) Established methods of mountain building all depend
either directly or indirectly on subduction zones. Three methods
are currently recognized:
... ... a) A subduction zone may lead directly to mountains
formed by ascending *magma and heat, as is the case in the Andes.
... ... b) The subduction process may also transport
*microcontinental fragments to the continental margin, where they
accrete as "*terranes", a process that has added significantly to
the North American West Coast over the past 400 million years.
... ... c) When an ocean is consumed by colliding continents, as
in the example of India and Asia, spectacular mountain building
can result.
     3) Mantle plumes produce island chains such as the Hawaiian
Islands. The plume remains relatively stationary while the
oceanic plate moves over it. Plumes are thought to rise all the
way from the core-mantle boundary, 2,900 kilometers below the
Earth's surface, in relatively narrow columns. On reaching the
base of the lithosphere, a plume spreads out, underplating a
large area of lithosphere, causing it to heat and be bowed
upward.
     4) Hot spots, the surface manifestations of mantle plumes,
are widely distributed around the Earth, although the exact
number is controversial. Hot spots are essentially stationary
relative to the faster-moving plates. No modern ocean could be
consumed at a subduction zone without a plate margin encountering
a hot spot, so the interaction between subduction zones and hot
spots must be common throughout geological time.
     5) Most of the mountain building activity on the western
margin of North America over the past 300 million years
represents episodes of *magmatism and deformation associated with
microcontinent collisions. The Sonoma, Nevada, and Sevier
mountain-building events are examples. The Rocky Mountain
(Laramide) orogeny, however, is distinctive because it is
characterized by a lack of magmatism coupled with widespread
deformation in the continental interior.
     6) The authors propose that an additional (fourth) method of
mountain building has been largely overlooked and may help
explain not only the Laramide Orogeny but also other unusual
geological features of the southwestern US. Their model involves
the interplay of the horizontal motions of traditional
subduction-related mountain-building processes with vertical
plumes of hot mantle ascending from thousands of kilometers below
the Earth's surface. The authors suggest that "together these
mechanisms may offer a convincing explanation for what long has
been a geologically puzzling part of the world and may lead to
better understanding of mountain building worldwide."
-----------
J.B. Murphy et al: Mantle plumes and mountains.
(American Scientist Mar-Apr 1999 87:146)
QY: J. Brendan Murphy [bmurphy@stfx.ca]
-----------
Text Notes:
... ... *magma: In general, any molten mass of rock.
... ... *microcontinental fragments: In general, any fragment or
remnant of continental crust up to approximately the size of
Madagascar (Malagasy).
... ... *terranes: (terrains) In general, a terrane is any
region of crust with well-defined margins which differs
significantly in apparent tectonic evolution from neighboring
regions.
... ... *magmatism: In general, the development and movement of
magma within the Earth.
-------------------
Summary & Notes by SCIENCE-WEEK [http://scienceweek.com] 11Jun99


4. ON THE EVOLUTIONARY TREE OF LIFE
In general, in a replicating biological system, the genetic
information encoded in DNA is transcribed directly or indirectly
into RNA. The ribonucleic acid molecule transcribed from DNA that
carries the coded information specifying the sequence of amino
acids in a protein is called "messenger RNA" (mRNA), and the
process of translating the information encoded in messenger RNA
occurs on cytoplasmic particles called "ribosomes". These
particles are molecular complexes approximately 25 nanometers in
diameter, containing several types of intrinsic (non-messenger)
RNA (ribosomal RNA; rRNA) and more than 50 different proteins.
Ribosomes are found in many types of living cells, both cells
with internal membrane-bound organelles such as a nucleus
(eukaryotes) and less complex cells without such organelles
(prokaryotes). The evolutionary relationship between prokaryotes
and eukaryotes has commonly been viewed from the perspective of
ribosomal RNA, with analyses of ribosomal RNA from many different
organisms providing the basis for what is called the "clonal
theory" of the evolution of eukaryotes from prokaryotes. In
general, this theory postulates that genes have been passed
directly from generation to generation, with modifications in the
genes resulting in the appearance of new organisms. In recent
years, however, this clonal theory of evolution has been found
inadequate [*Note #1]. ... ... J.A. Lake et al (3 authors at
University of California Los Angeles, US) present a short review
of current research in this area, the authors making the
following points:
     1) Ribosomal RNA genes cannot be used to distinguish genomes
that are mosaics (mixtures) of genes from different sources. By
relying too heavily on ribosomal RNA, attention has been diverted
away from considering the impact of gene acquisition from other
species (horizontal gene transfer) on the evolution of eukaryotic
genomes. Viewed now from the perspective of completed genome
sequences for a number of bacteria and for the yeast
Saccharomyces (a eukaryote), the clonal theory of eukaryotic
genome evolution contains evident flaws.
     2) The clonal theory began to crumble a decade ago when
consideration of a variety of genes from different organisms
indicated that their relationship to each other contradicted the
evolutionary "tree of life" derived from ribosomal RNA analysis
alone.
     3) As genomes contain large numbers of genes from different
functional classes, it is now possible to analyze the
evolutionary history of groups of genes that do similar jobs.
Until recently, phylogenetic conclusions were based on the
analysis of one or a few genes, but at present they are based on
the analysis of hundreds of genes. Thus, it is now possible to
ask questions about genome evolution that in the past could not
have been answered.
     4) The present consensus is that genes fall into 2
functional superclasses: a) information genes (those genes
involved in transcription, translation, and related processes);
b) operational genes (those genes involved in "*housekeeping").
     5) Eukaryotes appear to have obtained their informational
genes from an organism that is more closely related to certain
*archaebacteria than to either *proteobacteria or *cyanobacteria,
but the operational genes of eukaryotes appear to have derived
principally from proteobacteria. These new results begin to
explain the mystifying mixed apparent origins of eukaryotic
genomes [*Note #2]. 
     6) The current view is that even if eukaryotic genomes may
be chimeras (mixes from two or more sources), prokaryotic genomes
have evolved clonally and are not chimeric. However, the authors
suggest there is now growing evidence that in prokaryotes also,
horizontal gene transfer and chimerism prevail.
     7) The authors conclude: "Completion of genome sequencing
projects for prokaryotes... and for eukaryotes... are sure to
spur the dissolution of old paradigms and yield a new wave of
revelations about the evolutionary tree of life."
-----------
J.A. Lake et al: Mix and match in the tree of life.
(Science 26 Mar 99 283:2027)
QY: James A. Lake [lake@mbi.ucla.edu]
-----------
Text Notes:
... ... *Note #1: The phrase "clonal theory of evolution" must be
distinguished from "clonal selection theory", which is a specific
theory in immunology, and of no relevance here.
... ... *housekeeping: So-called "housekeeping" genes are genes
expressed in most cell types because they code for proteins
involved in essential functions such as metabolic cycles.
... ... *archaebacteria: The archaebacteria (also called the
Archaea) are a subkingdom of bacteria considered to be ancient
compared to other bacterial kingdoms, and possibly the most
ancient life forms and the ancestors of all eukaryotes. They
typically exist in extreme environments, and include the
methane-producing bacteria (methanogens), the "salt-loving"
bacteria (halophilic bacteria), and the sulfur-acid tolerant
thermoacidophilic bacteria.
... ... *proteobacteria: (purple bacteria) A general category
comprising a large number of diverse forms (e.g., Escherichia
coli)
... ... *cyanobacteria: (formerly misclassified as blue-green
algae). Photosynthetic bacteria containing chlorophyll.
... ... *Note #2: The current classification schemes used by
biologists for the most primitive organisms are in a state of
flux (see the background material below).
-------------------
Summary & Notes by SCIENCE-WEEK [http://scienceweek.com] 11Jun99
-------------------
Related Background:
BIO-TAXONOMY: EMERGENCE OF A SHARP PERSONAL CONTROVERSY
In a recent report (see Related Background material below) we
briefed a proposal by Ernst Mayr for a return to the *prokaryote-
eukaryote domain dichotomy from the present *archaea-eubacteria-
eukaryote domain trichotomy that has come to be used by many
biologists during the past decade. The details of the distinction
are provided in the report attached below, so we will not repeat
them. The controversy is of some interest in biology, as perhaps
a possible controversy concerning the present standard model
classification scheme of fundamental particles and forces in
physics would be to physicists. The domain trichotomy idea in
bio-taxonomy was first proposed in the 1980s by Carl Woese, who
like Ernst Mayr, is a member of the US National Academy of
Sciences. Writing in the same journal in which Mayr's proposal
appeared a few weeks ago, Woese now attempts to rebut Mayr's
ideas with an apparent singular vehemence, proposing that the
issue is more profound than that of merely assessing the utility
of a classification scheme. Woese writes: "If there were ever an
issue in biological classification that cannot be settled by
pedantry, it is this one." [Editor's note: This is not completely
gratuitous, since in his paper Mayr states, "Here it must be
remembered that Woese was not trained as a biologist and quite
naturally does not have an extensive familiarity with the
principles of classification."] And again from Woese: "To Mayr,
the issue is one of whether we should define two or three domains
and what the classificatory precedents or rules for deciding this
are. However, the *universal phylogenetic tree tells us that the
domains are unique among taxa and that their number and their
composition are not subject to classificatory fiat, but are
naturally defined." Woese's idea, apparently, is that the
trichotomous classification scheme is discovered rather than
constructed, which implies a significant problematic
philosophical subtext that is not amplified in his paper. In
summary, Woese makes the following points concerning his
position: 1) Mayr's article is not a taxonomic quibble but a "de
facto pronouncement on the nature of biology." A biological
classification is in effect an overarching evolutionary theory
that guides our thinking and experimentation, and it must be
structured to reflect evolutionary reality. 2) The prokaryote-
eukaryote dichotomy, which Mayr proposes to reinstitute, is a
failed taxonomic theory that was never recognized as theory and
therefore never tested in a timely fashion, with the consequence
that it has adversely affected the development of biology,
especially microbiology, in the latter half of this century. 3)
The scientifically perceived importance of a group of organisms
must reflect the natural importance of the group. 4) Microbial
diversity is far more than a listing of distinguishable microbial
species. We need to understand the quality of microbial
diversity, for it is the diversity that defines the biosphere of
this planet. 5) Evolution must be integrated into the fabric of
molecular biology... Any comprehensive understanding of a
biological entity, be it an organism or a molecule, necessarily
has an evolutionary component. Woese concludes: "The disagreement
between Dr. Mayr and myself is not actually about classification.
It concerns the nature of Biology itself. Dr. Mayr's biology
reflects the last billion years of evolution; mine, the first
three billion. His biology is centered on multicellular organisms
and their evolutions; mine on the *universal ancestor and its
immediate descendants. His is the biology of visual experience,
of direct observation. Mine cannot be directly seen or touched;
it is the biology of molecules, of genes and their inferred
histories. Evolution for Dr. Mayr is an "affair of phenotypes".
For me, evolution is primarily the evolutionary _process_, not
its outcomes. The science of biology is very different from these
two perspectives, and its future even more so." [Editor's note:
Ignoring the personalized undercurrents, the essential
controversy here is apparently between a classification system
based on utility criteria and observed similarities and
differences among entities (Mayr), and a classification scheme
based on theoretical and experimental molecular-genetic
relationships (Woese). The question of why there must be only one
classification scheme in use by working biologists is not
addressed by either Mayr or Woese.]
-----------
C.R. Woese (University of Illinois Urbana-Champaign)
Default taxonomy: Ernst Mayr's view of the microbial world.
(Proc. Natl. Acad. Sci. US 15 Sep 98 95:11043)
QY: Carl R. Woese [carl@ninja.life.uiuc.edu]
-----------
Text Notes:
... ... *prokaryote-eukaryote domain dichotomy: See reports
attached below.
... ... *archaea-eubacteria-eukaryote domain trichotomy: See
reports attached below.
... ... *universal phylogenetic tree: Refers to the present
taxonomic-evolutionary classification scheme for all life on
Earth.
... ... *universal ancestor: Refers to the common ancestor from
which all life on Earth is considered to have derived. See
Related Background report attached below of SW 3 Jul 98).
-------------------
Summary & Notes by SCIENCE-WEEK [http://scienceweek.com] 16Oct98
-------------------
Related Background:
BIO-TAXONOMY: A PROPOSAL FOR ONLY TWO EMPIRES
The physicist confronting bio-taxonomy for the first time may
experience bewilderment: there are in excess of 30 million
species of life forms, the classification system is far from
simple, the system has some historically based confusions, and
the system is frequently redefined. Perhaps only the organic
chemist can feel a full empathy here, since organic chemistry is
faced with the similar problem of classifying millions of organic
chemical entities. A fundamental consideration is that in the
context of such a diversity of objects, a self-consistent
classification scheme is of extreme importance. At the present
time, in biology, there is a significant controversy concerning
primary categories, and that is the subject of this report. Two
main groups of life forms have been recognized for some time,
prokaryotes and eukaryotes. Prokaryotes are cells without a cell
nucleus and other membrane-bound organelles, and eukaryotes are
cells with a cell nucleus and other membrane-bound organelles.
(Organisms composed of eukaryote cells are also called
"eukaryotes"). For example, all bacteria are prokaryotes; all
complex animals, plants, etc., are eukaryotes. Fifteen years ago,
C.R. Woese (University of Illinois Urbana-Champaign, US) proposed
that the prokaryotes actually consist of two main groups, the
eubacteria and the archaebacteria, and that the differences
between these two groups are as great as the differences between
prokaryotes and eukaryotes, and that as a consequence a
tripartite primary scheme should be used, the primary categories
(kingdoms or empires) consisting of Eubacteria, Archaebacteria,
and Eukaryotes. Woese's differentiation of eubacteria and
archaebacteria was based on *habitats, cell wall constituents,
genome organization, and various aspects of protein synthesis
biochemical machinery, and during the past decade most biologists
have apparently accepted his categorization scheme.
... ... Now Ernst Mayr (1904- ), a prominent biologist, proposes
a rejection of the Woese categorization and a return to a scheme
involving only 2 primary categories (empires), the Prokaryotes
and Eukaryotes. Mayr makes the following points: 1) A
classification scheme is essentially an information storage and
retrieval system, permitting the location of an entity with a
minimum of effort and loss of time, the objective optimally
achieved by arranging entities in a hierarchy of classes, ranked
by degree of similarity. 2) Evidence indicates that the
archaebacteria are so much more similar to the eubacteria than to
the eukaryotes, that their removal from the prokaryotes is not
justified. The eukaryotes differ from the prokaryotes (including
the archaebacteria) not only by the possession of a nucleus and
*mitosis but also by individual protein-rich chromosomes,
*meiotic sexuality (including viable regular cell fusions),
cellular organelles, highly complex sets of regulatory genes, and
all those genes that permit biodiversity... When a biologist
speaks of eukaryotes, he or she has in mind palms, oaks, and
orchids; mice, bats, and whales; and hummingbirds, chickens, and
ostriches. And this world of highly evolved eukaryotes is simply
an entirely different world from the world of the two kinds of
bacteria, the Prokaryotes. 3) Ranking, in any scheme of
classification of items (living or not), is by necessity based on
degree of difference. The two kinds of bacteria, in the vast
majority of their characteristics, are exceedingly similar to
each other and fundamentally so different from the eukaryotes
that they have to be ranked as a single *taxon, the prokaryotes,
different from the only other taxon of this rank, the eukaryotes.
Mayr suggests that only a two-empire classification correctly
reflects this structure of the living world.
-----------
E. Mayr (Harvard University, US)
Two empires of three?
(Proc. Natl. Acad. Sci. US 18 Aug 98 95:9720)
QY: Ernst Mayr [emayr@oeb.harvard.edu]
-----------
Text Notes:
... ... *habitats: Many species of archaebacteria live in hot
acidic conditions, growing best at temperatures approaching 100
degrees centigrade. Because of this, it has been suggested the
lineage is more ancient than eubacteria, arising during
primordial conditions on Earth.
... ... *mitosis: In this context, division of the cell nucleus.
... ... *meiotic sexuality: A reduction division process whereby
a nucleus divides by 2 divisions into 4 nuclei, each containing
half the original number of chromosomes.
... ... *taxon: The organisms comprising a particular taxonomic
entity.
-------------------
Summary & Notes by SCIENCE-WEEK [http://scienceweek.com] 25Sep98


5. NEUROBIOLOGY: DENDRITE MORPHOLOGY INDUCED BY SYNAPTIC ACTIVITY
Viewed as a computing machine analog, the developing brain
consists of a large number of elements (neurons) engaged in
various mechanisms of self-wiring. To the degree that brain
programs are hard-wired, this self-wiring during development (and
apparently after gross development is completed) constitutes
programming of brain functions. "Self-wiring" in the brain is the
biological production of new or increased connections between
neurons, either as a result of genetically programmed biochemical
events, or as a result of functional activity of the neurons
already connected or about to be connected ab initio. These two
aspects constitute two major investigative areas in developmental
neurobiology, each with a long history of intensive research.
Concerning new connections as a result of neuron activity, one
important question is what changes in morphology, if any, occur
in the various parts of nerve cells in response to input from
other nerve cells. Again, viewing the brain as a computing
machine analog, at this level the question concerns how the input
history of a computing element (e.g., the input history of a
transistor) changes the physical architecture (and thus the
input-output behavior) of that element. Neurons, the biological
elements, contain 3 unique structural features that differentiate
them from other biological cells: the "axon", which is
specialized for intracellular information transfer over a
relatively long distance (e.g., impulse propagation); one or more
"dendrites", which are often the sites at which information is
received from other neurons; and the "synapse", which is the
point of information transfer between neurons. In general,
dendrites are neuronal processes that tend to be thicker and much
shorter than axons. Dendrites are often highly branched, giving
rise to a dense network of processes. In certain types of
neurons, close optical examination of dendrites reveals the
presence of numerous finger-like projections or thickenings
(dendritic spines) arising from the main shaft of the dendrite,
and each spine is apparently a synaptic input site at which the
neuron receives information from another nerve cell. Relatively
little is known about the role of activity in the development of
dendritic morphology, and the studies that have been done have
produced inconsistent results. In the mammalian brain, dendrites
develop in a stereotyped sequence: Soon after birth the
relatively smooth dendrites of neonates sprout numerous thin
filamentous extensions of the cell surface ("filopodia-like
protrusions") which are later replaced by dendritic spines as the
brain matures. ... ... M. Maletic-Savatic et al (3 authors at
Cold Spring Harbor Laboratory, US) now report a study using
*vital imaging of dendrites in *living rat brain slices to
directly observe dendritic morphogenesis evoked by synaptic
activity. The authors report their results indicate that synaptic
activity can produce rapid growth in *postsynaptic dendrites.
Growth was input specific, occurring only close to activated
parts of the dendrite, and required synaptic *NMDA receptor
activation. This activity-induced growth was most prominently
expressed as an increase in long thin filopodia-like protrusions.
The authors suggest that if such structures develop into
dendritic spines and synapses, they will have greater likelihood
of connecting with presynaptic axons that were active during the
synaptic stimulus, providing a mechanism for *synaptic plasticity
satisfying *Hebbian rules. The authors suggest such a mechanism
could play a role in the establishment of functional neural
circuits during development and memory storage.
-----------
M. Maletic-Savatic et al: Rapid dendritic morphogenesis in CA1
hippocampal dendrites induced by synaptic activity.
(Science 19 Mar 99 283:1923)
QY: M. Maletic-Savatic, Cold Spring Harbor Laboratory, Cold
Spring Harbor, NY 11724 US.
-----------
Text Notes:
... ... *vital imaging: The visualization technique in this
report involved the infection of neurons in cultured rat brain
slices (CA1 hippocampus pyramidal neurons) by a neurotropic virus
genetically engineered to express a green fluorescent protein.
Living infected neurons were visualized with a custom-built laser
scanning microscope, the infected neurons exhibiting bright
homogeneous fluorescence throughout their dendritic and axonal
branches, with detailed morphology revealed.
... ... *living rat brain slices: "Rat brain slices" are exactly
that, the rat brain removed from the animal and a thin slice of a
particular region prepared in an appropriate solution for
electrophysiological recording of nerve cell activity.
... ... *postsynaptic dendrites: The neuron attachments
associated with a synapse are denoted as follows: the input
attachment is called "presynaptic"; the output attachment is
called "postsynaptic".
... ... *NMDA receptor: (N-methyl-D-aspartate receptor) This is a
type of glutamate receptor. Glutamate is a major excitatory amino
acid neurotransmitter, accounting for an estimated 40 percent of
all nerve signals in the mammalian brain, and involved in
phenomena such as neural development, learning, and memory
formation. A glutamate receptor is a molecular site that mediates
the actions of glutamate neurotransmitters. In this report, the
significance of the requirement of NMDA activation is that it
suggests that the dendrite morphological changes were due to
actual synaptic activity rather than to the electrical fields
produced by electrical stimulation of the tissue. Thus, chemical
blockade of NMDA receptors prevented the morphological changes in
response to electrical stimulation.
... ... *synaptic plasticity: In general, the term "synaptic
plasticity" refers to the changeability of neuronal synaptic
connections, usually as a result of ongoing neural activity.
... ... *Hebbian rules: In 1949, psychologist D.O. Hebb
hypothesized that coordinated activity of a presynaptic terminal
and a postsynaptic neuron would strengthen the synaptic
connections between them. In general, Hebb's postulate implies
that synaptic terminals strengthened by correlated activity will
be retained or sprout new branches, whereas those terminal
connections that are persistently weakened by uncorrelated
activity will eventually lose their hold on the postsynaptic
cell. Another form of the Hebb postulate is as follows: When a
postsynaptic neuron becomes depolarized, it generates a
biochemical reaction or a trophic factor that stabilizes the
excitatory synapses that are firing at that time. Hebb's
postulate has been found useful in explaining various
neurophysiological experimental observations related to learning
and memory.
-------------------
Summary & Notes by SCIENCE-WEEK [http://scienceweek.com] 11Jun99
-------------------
Related Background:
TARGET-SPECIFIC PRESYNAPTIC PLASTICITY IN NEURONS
The term "mossy fibers" refers to a type of nerve fiber in the
brain with large axon terminal endings, and their synapses
(connections to other nerve cells) are among the largest in the
mammalian central nervous system. The term "synaptic transmiss-
ion" refers to the transmission of electrical activity from one
nerve cell to another via the synapse -- the connection between
them. The hippocampus is a deep region of the brain involved with
many fundamental activities, including memory storage. The term
"interneurons" refers to nerve cells localized in a succinct
region (population of nerve cells), with the primary function of
these nerve cells an involvement with information processing in
the region, rather than with input to the region or output from
the region: interneurons are therefore involved in "local
circuitry"... The term "tetanic stimulation" refers to repetitive
stimulation. "Long-term potentiation" is an apparent facilitation
of synaptic transmission following repetitive stimulation under
certain conditions. In this context, the term "depression" refers
to a long-term reduction in efficacy of synaptic transmission.
Cyclic adenosine monophosphate (cAMP) is an important
postsynaptic intracellular substance activated by incoming
synaptic activity, a "messenger" involved in various aspects of
cell regulation and protein synthesis. In general, the term
"afferent pathway" refers to any input pathway, as opposed to an
output pathway (efferent). ... ... Maccaferri et al (3 authors at
National Institutes of Health, US) report a comparison of mossy
fiber synaptic transmission at hippocampal pyramidal cells and
interneurons in rat brain slices, finding that tetanic
stimulation of mossy fibers induces long-term potentiation in
pyramidal neurons, but is either without effect or induces
depression at synapses with interneurons. Furthermore, unlike
transmission onto pyramidal neurons, transmission onto
interneurons was not potentiated after cAMP activation. The
authors suggest their results indicate that synaptic terminals
arising from a common afferent pathway do not behave as a single
computational unit, but are functionally specialized with effects
depending on the postsynaptic target.
QY: Chris J. McBain [crismcb@codon.nih.gov]
(Science 27 Feb 98) (Science-Week 13 Mar 98)
-------------------
Related Background:
A NEW TYPE OF SYNAPTIC PLASTICITY OF NEOCORTICAL NEURONS
The term "synaptic plasticity" refers to a changeability of
synaptic connections and/or the efficacy of particular connect-
ions. "Cultured neurons" are embryological neurons separated from
the animal and growing and making connections in a suitable
experimental chamber. Glutamate is a major excitatory amino acid
neurotransmitter (transmitter substance at synapses) in the
brain, involved in about 40% of all brain activity. The term
"Hebbian modification" (named after the neuropsychologist Donald
Hebb) refers to the Hebbian "rule" that essentially states that
when one nerve cell repeatedly activates another nerve cell,
changes involving growth or metabolism occur in one or both nerve
cells that increase the efficiency of the activation.
... ... Turrigiano et al (5 authors at Brandeis University, US)
report a new form of synaptic plasticity in cultured neurons that
increases or decreases the strength of all of a neuron's synaptic
inputs as a function of activity, the changes partly due to
postsynaptic alterations in the response to glutamate. The
authors suggest that such "synaptic scaling" may help prevent
saturation of firing rates during developmental changes in the
number and strength of synaptic inputs, may stabilize synaptic
strengths during Hebbian modification, and may facilitate
competition between synapses and associated elimination of
synapses during development.
QY: Gina G. Turrigiano [turrigiano@binah.cc.brandeis.edu]
(Nature 26 Feb 98) (Science-Week 13 Mar 98)


6. MEDICAL SCIENCE: DEATHS RELATED TO LIPOSUCTION
Liposuction is the most common cosmetic operation in the US. The
technique of "tumescent liposuction" is a relatively new
procedure that has gained popularity in the past decade, in part
because of its purported safety. Tumescent liposuction involves
the subcutaneous infusion of a solution containing a local
anesthetic drug, followed by the aspiration of fat through
microcannulas. The components of the infusate provide prolonged
local anesthesia and minimize blood loss. Large-volume
liposuction, defined as the removal of more than 1500 milliliters
of fat, may require the infusion of several liters of this
solution. Depending on the extent of liposuction and the
patient's preference, the operation can be performed with the
patient under conscious sedation or with regional (epidural) or
general anesthesia. In contrast, older liposuction techniques
were performed under general anesthesia, used larger cannulas and
no infusate, and often necessitated blood transfusions. In the
single year 1996, according to the American Academy of Cosmetic
Surgery, 292,942 liposuction procedures were performed, an
increase of 300 percent from 1990, and of these procedures, 92
percent involved tumescent perfusions. Since reporting of adverse
events associated with tumescent liposuction is not mandatory,
the incidence of complications and deaths is unknown.
... ... R.B. Rao et al (3 authors 2 installations, US) now report
a study of the medical records of the Office the Chief Medical
Examiner of the City of New York between 1993 and 1998, the study
comprising 48,527 total deaths referred to this office, and the
identification of 5 deaths after tumescent liposuction. A
detailed analysis was made of these 5 patients. Three patients
died as a result of precipitous intraoperative (i.e., during
surgery) hypotension (i.e., low blood pressure) and bradycardia
(i.e., slowing of the heartbeat under 60 beats per minute) with
no definitively identified cause; one patient died of fluid
overload; one patient died of deep venous thrombosis (i.e., blood
clot obstruction) of calf veins after tumescent liposuction of
the legs. The authors conclude: "Tumescent liposuction can be
fatal... There is no mandatory reporting or review of adverse
events associated with this privately performed procedure, so the
true incidence of complications and deaths is unknown. Tumescent
liposuction is not a trivial procedure, because it has the
potential to kill otherwise healthy persons... Deaths due to
cosmetic surgery should be a matter for serious public concern."
-----------
R.B. Rao et al: Deaths related to liposuction.
(New England J. Med. 13 May 99 340:1471)
QY: Rama B. Rao [raorama@pol.net]
-------------------
Summary by SCIENCE-WEEK [http://scienceweek.com] 11Jun99   


=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

IN FOCUS: ON THE EVOLUTION OF THE VERTEBRATE BRAIN
"The brain of a fish isn't much. A fish has a notochord or spinal
cord, which it shares with even humbler invertebrates. A
primitive fish also has a little swelling at the front end of the
spinal cord, which is its brain. In higher fish, the swelling is
further developed but still weighs no more than a gram or two.
That swelling corresponds in higher animals to the hindbrain or
brainstem and the midbrain. The brain of modern fish is chiefly
midbrain, with a tiny forebrain; in modern amphibians and
reptiles, it is the other way around. And yet fossil endocasts of
the earliest known vertebrates show that the principal divisions
of the modern brain (hindbrain, midbrain, and forebrain, for
example) were already established. Five hundred million years
ago, swimming in the primeval sea, there were fishy creatures
called ostracoderms and placoderms whose brains had recognizably
the same major divisions as ours. But the relative size and
importance of these components, and even their early functions,
were certainly very different from today. One of the most
engaging views of the subsequent evolution of the brain is a
story of successive accretion and specialization of three further
layers surmounting the spinal cord, hindbrain, and midbrain.
After each evolutionary step, the older portions of the brain
still exist and must still by accommodated. But a new layer with
new functions has been added."

-- Carl Sagan: _The Dragons of Eden_
   (Random House, New York 1977, p.53)   


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