bluuebunny/crossref_metadata_2025 huggingface dataset:
Gallium-67 Localization in Rat and Mouse Tumors
Authors: Hayes R. L. , Nelson B. , Swartzenoruber D. C. , Carlton J. F. , Byrd B. L
Published: October 2006

Various nonosseous tumors in mice and rats concentrate gallium-67—ESR-586 preputial gland carcinoma, P-1798 lymphosarcoma, C3H/ HeJ mammary tumor, AKR/J thymic lymphoma, R-3259 giant cell sarcoma, Walker-256 carcinosarcoma, and a new transplantable neoplasm of rats. This last tumor showed the greatest affinity for galliun. Viable tumor cells are mainly responsible for uptake of gallium-67; autoradiographic studies indicate it is chiefly located in tumor cytoplasm.
Experimental Petrology of Lunar Material: the Nature of Mascons, Seas, and the Lunar Interior
Authors: O'Hara Michael J. , Biggar Gordon M. , Richardson Stephen W.
Published: October 2006

One-atmosphere melting data show that Apollo 11 samples are near cotectic. Melting relations at pressures up to 35 kilobars show that clinopyroxenite or amphibole peridotite are possible lunar interiors. Mascons cannot be eclogite; they may be ilmenite accumulate. Hot lunar surface material will boil off alkalis.
Petrogenesis of Lunar Basalts and the Internal Constitution and Origin of the Moon
Authors: Ringwood A. E. , Essene E.
Published: October 2006

Petrographic and electron-microprobe studies combined with high pressure-temperature investigations of phase relationships in average Apollo 11 basalt and possible source material show that the lower parts of maria may be composed of eclogite (density 3.74 grams per cubic centimeter), thus explaining the existence of mascons. The Apollo 11 basalt was probably formed at depths of 200 to 400 kilometers by a small degree of partial melting from pyroxenitic source material [FeO/(FeO + MgO) = 0.25, Al
2
O
3
∼4 percent, CaO ∼3 percent]. This composition may be representative of the lunar interior and yields the observed mean lunar density and moment of inertia. Present data are in conflict with fission, binary planet, and capture hypotheses of lunar origin but are consistent with Ringwood's (1966) precipitation hypothesis.
Silicate Liquid Immiscibility in Lunar Magmas, Evidenced by Melt Inclusions in Lunar Rocks
Authors: Roedder Edwin , Weiblen Paul W.
Published: October 2006

Examination of multiphase melt inclusions in 91 sections of 26 lunar rocks revealed abundant evidence of late-stage immiscibility in all crystalline rock sections and in soil fragments and most breccias. The two individual immiscible silicate melts (now glasses) vary in composition, but are essentially potassic granite and pyroxenite. This immiscibility may be important in the formation of the lunar highlands and tektites. Other inclusions yield the following temperatures at which the several minerals first appear on cooling the original magma: ilmenite (?) liquidus, 1210°C; pyroxene, 1140°C; plagioclase, 1105°C; solidus, ∼1075°C. The glasses also place some limitations on maximum and minimum cooling rates.
Lunar Soil: Size Distribution and Mineralogical Constituents
Authors: Duke Michael B. , Woo Ching Chang , Bird Melvin L. , Sellers George A. , Finkelman Robert B.
Published: October 2006

The lunar soil collected by Apollo 11 consists primarily of submillimeter material and is finer in grain size than soil previously recorded photographically by Surveyor experiments. The main constituents are fine-grained to glassy rocks of basaltic affinity and coherent breccia of undetermined origin. Dark glass, containing abundant nickel-iron spheres, coats many rocks, mineral, and breccia fragments. Several types of homogeneous glass occur as fragments and spheres. Colorless spheres, probably an exotic component, are abundant in the fraction finer than 20 microns.
Magnetic Resonance Properties of Some Lunar Material
Authors: Weeks R. A. , Chatelain A. , Kolopus J. L. , Kline D. , Castle J. G.
Published: October 2006

Paramagnetic resonance spectra of Apollo 11 fines and rocks were measured at 9 and 35 gigahertz and at 4°, 80°, and 300°K. At both frequencies the material has an intense absorption at
g
= 2, with a line width of ∼950 gauss. Fe ions with strong exchange interactions produce this resonance. A comparison of the resonance absorption due to Fe
3+
showed that the energy of the crystal field interaction was ∼0.1 per centimeter. Mn
2+
was identified in several samples, and an absorption at
g
= 1.89 was tentatively attributed to Ti
3+
. The nuclear magnetic resonance spectra of
27
Al had a distribution of asymmetry parameters η ranging from 0.25 to 0.75 and had nuclear quadrupole coupling constants
e
2
qQ
/
h
of approximately 3 megahertz.
Solar Radiation Effects in Lunar Samples
Authors: Hapke B. W. , Cohen A. J. , Cassidy W. A. , Wells E. N.
Published: October 2006

Optical properties of the pulverized crystalline rocks from the Apollo 11 samples are different from the optical properties of lunar soil. Changes in these properties were induced in the samples by ultraviolet and x-irradiation, standing, and heating. The albedo and spectrum of the soil differed significantly from expected values.
5-Hydroxytryptamine: A Cytospecific Growth Stimulator of Cultured Fibroblasts
Authors: Boucek Robert J. , Alvarez T. Ralph
Published: October 2006

5-Hydroxytryptamine (serotonin) in micromolar amounts increased the growth of fibroblasts in culture while not affecting five other cell lines. Serotonin appeared to shorten the lag phase of cell growth. The effect was less when serotonin was added to the fibroblast culture after the initial 24-hour period. The two functional groups of the serotonin molecule were required for growth enhancement. Serotonin in millimolar concentrations was toxic to fibroblasts.
Alanine: Key Role in Gluconeogenesis
Authors: Felig Philip , Pozefsk Thomas , Marlis Errol , Cahill George F.
Published: October 2006

Of 20 amino acids measured, alanine is the principal amino acid released by forearm muscle of man, in accord with its being the principal amino acid extracted by liver for gluconeogenesis. This occurs in both the postabsorptive state and after 4 to 6 weeks of starvation, when total amino acid release is markedly diminished.
Rat Thoracic Duct Lymphocytes: Types that Participate in Inflammation
Authors: Koster F. , McGregor D. D.
Published: October 2006

Newly formed small lymphocytes with a short life-span in the blood are the only cells from thoracic duct lymph which accumulate in acutely inflamed tissue. This conclusion is drawn from studies in which rats with induced peritoneal exudates were injected intravenously with radioactively labeled thoracic duct cells. Radioactivity, originally vested in newly formed donor small lymphocytes, was found later in a small number of similar exudate cells. Small lymphocytes generated 10 days or more before the thoracic ducts were cannulated failed to localize in peritoneal exudates, although the cells moved in large numbers from the blood in to lymph nodes.
Unified Account of the Variable Effects of Carbon Dioxide on Nerve Cells
Authors: Walker J. L. , Brown A. M.
Published: October 2006

When the abdominal ganglion of
Aplysia californica
is exposed to 5 percent carbon dioxide, certain neurons are depolarized, others hyperpolarized, and some are unaffected. The effect of increased carbon dioxide is due solely to the concomitant fall in extracellular
p
H, which causes an increase in membrane chloride conductance of responsive cells. The directional change of the membrane potential in different neurons is determined by the relative values of the chloride equilibrium and the resting potentials. The chloride equilibrium potentials are calculated after direct measurement of the intracellular chloride activity with a chloride microelectrode.
Habituation and Dishabituation of the Gill-Withdrawal Reflex in
Aplysia
Authors: Pinsker Harold , Kupfermann Irving , Castellucci Vincent , Kandel Eiuc
Published: October 2006

A behavioral reflex mediated by identified motor neurons in the abdominal ganglion of
Aplysia
undergoes two simple forms of short-term modification. When the gill-withdrawal reflex was repeatedly evoked by a tactile stimulus to the siphon or mantle shelf, the amplitude of the response showed marked decrement (habituation). After a period of rest the response showed spontaneous recovery. The amplitude of a habituated response was facilitated by the presentation of a strong tactile stimulus to another part of the animal (dishabituation). Many characteristics of habituation and dishabituation in
Aplysia
are similar to those in vertebrates.
Atomic Structure of Acetylcholinesterase from
Torpedo californica
: A Prototypic Acetylcholine-Binding Protein
Authors: Sussman Joel L. , Harel Michal , Frolow Felix , Oefner Christian , Goldman Adrian , Toker Lilly , Silman Israel
Published: October 2006

The three-dimensional structure of acetylcholinesterase from
Torpedo californica
electric organ has been determined by x-ray analysis to 2.8 angstrom resolution. The form crystallized is the glycolipid-anchored homodimer that was purified subsequent to solubilization with a bacterial phosphatidylinositol-specific phospholipase C. The enzyme monomer is an α/β protein that contains 537 amino acids. It consists of a 12-stranded mixed β sheet surrounded by 14 α helices and bears a striking resemblance to several hydrolase structures including dienelactone hydrolase, serine carboxypeptidase-II, three neutral lipases, and haloalkane dehalogenase. The active site is unusual because it contains Glu, not Asp, in the Ser-His-acid catalytic triad and because the relation of the triad to the rest of the protein approximates a mirror image of that seen in the serine proteases. Furthermore, the active site lies near the bottom of a deep and narrow gorge that reaches halfway into the protein. Modeling of acetylcholine binding to the enzyme suggests that the quaternary ammonium ion is bound not to a negatively charged "anionic" site, but rather to some of the 14 aromatic residues that line the gorge.
Reactions of Alpha Methylene Lactone Tumor Inhibitors with Model Biological Nucleophiles
Authors: Kupchan S. Morris , Fessler Dyral C. , Eakin M. Allan , Giacobbe Thomas J.
Published: October 2006

Thiols are the most reactive nucleophilic reagents among the biological models investigated. They undergo "Michael-type" addition to the polyfunctional sesquiterpene lactones. The rapid rates of reaction with L-cysteine were measured and the reaction products were characterized. Each addition of thiol successively decreased the cytotoxicity of the adducts formed.
Obesity: Absence of Satiety Aversion to Sucrose
Authors: Cabanac M. , Duclaux R.
Published: October 2006

In obese subjects, ingestion of glucose did not cause the transformation of the gustative sucrose sensation from pleasant to unpleasant as in normal subjects. This result is consistent with the theory of a decreased sensitivity to internal signals in the control of food intake of obese people.
"Hypersexuality" and Behavioral Changes in Cats Caused by Administration of
p
-Chlorophenylalanine
Authors: Ferguson James , Henriksen Steven , Cohen Harry , Mitchell George , Barchas Jack , Dement William
Published: October 2006

The behavior of 26 male cats was systematically observed before, during, and after daily administration of the tryptophan hydroxylase inhibitor,
p
-chlorophenylalanine. These observations established that "hypersexuality," increased aggression, and perceptual disorientation are sequelae of the chronic administration of the drug in cats.
Superconductivity in Layered Structure Organometallic Crystals
Authors: Gamble F. R. , DiSalvo F. J. , Klemm R. A. , Geballe T. H.
Published: October 2006

Superconductivity persists in several, layered, transition metal dichalcogenide superconductors when the layers are spread apart to accommodate organic molecules between them. These materials are of interest not only because of their two-dimensional character but also because they may provide a means for examining hypotheses regarding organic molecules and superconductivity.
Maize Leaf Elongation: Continuous Measurements and Close Dependence on Plant Water Status
Authors: Hsiao Theodore C. , Acevedo Edmundo , Henderson D. W.
Published: October 2006

A simple method was developed for measuring extensive growth of intact leaves of monocots on a minute-by-minute basis. Growth was markedly reduced by a slight reduction in leaf water potential. When plants mildly deficient in water were irrigated, growth resumed virtually instantly. The transitional rapid growth after watering suggests that water deficit increased cell extensibility.
Catecholamine Biosynthesis in Brains of Rats Treated with Morphine
Authors: Clouet Doris H. , Ratner Milton
Published: October 2006

In the brains of rats without tolerance to morphine, the accumulation of [14C]dopamine formed from [14C]tyrosine injected intracisternally is increased, reaching a maximum in the hypothalamus and striatum 1 hour after administration of morphine. In tolerant rats, the rate of incorporation of carbon-14 into dopamine and into norepinephrine in these areas is more than twice that in animals that have received only one injection of morphine.
Endotoxin: Stimulation of Bone Resorption in Tissue Culture
Authors: Hausmann E. , Raisz L. G. , Miller W. A.
Published: October 2006

Bacterial endotoxins can stimulate the release of previously incorporated calcium-45 and tritiated proline from fetal rat bone in tissue culture. Endotoxin from
Bacteroides melaninogenicus
, an organism regularly found in the gingival crevice of man, produces a response similar to parathyroid hormone and is effective at doses as low as 0.1 microgram per milliliter. This response is inhibited by serum and dependent upon the presence of albumin. Endotoxins may play a role in the bone loss characteristic of human periodontal disease.
Formation Flight of Birds
Authors: Lissaman P. B. S. , Shollenberger Carl A.
Published: October 2006

Formation flight of birds improves aerodynamic efficiency. Theoretically, 25 birds could have a range increase of about 70 percent as compared with a lone bird, the advantage being more pronounced when there is a tail wind. A vee formation is required to equally distribute the drag saving, and, contrary to other statements, the lead bird does not necessarily have the most strenuous position. The angle of the predicted vee compares with that observed in nature; stability mechanisms are described which make it easy and natural for the bird to sense optimal formations.
Malaria Resistance: Artificial Induction with a Partially Purified Plasmodial Fraction
Authors: D'Antonio Lawrence E. , Spira Dan T. , Fu Rosa Chang , Dagnillo Donna M. , Silverman Paul H.
Published: October 2006

Plasmodium berghei
were released from mouse erythrocytes by passage through a French pressure cell. The released organisms were washed and disintegrated; the soluble portion was chromatographed on a Sephadex (G-200) column. The void-volume eluate contained an erythrocyte-free plasmodial fraction which behaved as a vaccine, preventing parasitemia, anemia, and death in mice subsequently challenged with living
Plasmodium berghei
.
Motoneuron Morphology and Synaptic Contacts: Determination by Intracellular Dye Injection
Authors: Davis William J.
Published: October 2006

The structure and dendritic connections of an identified crustacean motoneuron were analyzed by intracellular injection of dye. Some processes of the neuron end in the ganglionic neuropil, but most terminate on axons which pass through the ganglion in specific, identifiable tracts. The former processes are ipsilateral to the soma, while the latter, as well as their connections, display bilateral symmetry. Structural and functional evidence suggests that the demonstrated contacts are synaptic junctions, and that the approach can therefore be used to study patterns of synaptic organization in complex neural networks.
California Earthquakes: Why Only Shallow Focus?
Authors: Brace W. F. , Byerlee J. D.
Published: October 2006

Frictional sliding on sawcuts and faults in laboratory samples of granite and gabbro is markedly temperature-dependent. At pressures from 1 to 5 kilobars, stick-slip gave way to stable sliding as temperature was increased from 200 to 500 degrees Celsius. Increased temperature with depth could thus cause the abrupt disappearance of earthquakes noted at shallow depths in California.
Differing Lymphokine Profiles of Functional Subsets of Human CD4 and CD8 T Cell Clones
Authors: Salgame Padmini , Abrams John S. , Clayberger Carol , Goldstein Harris , Convit Jacinto , Modlin Robert L. , Bloom Barry R.
Published: October 2006

Functional subsets of human T cells were delineated by analyzing patterns of lymphokines produced by clones from individuals with leprosy and by T cell clones of known function. CD4 clones from individuals with strong cell-mediated immunity produced predominantly interferon-γ, whereas those clones that enhanced antibody formation produced interleukin-4. CD8 cytotoxic T cells secreted interferon-γ. Interleukin-4 was produced by CD8 T suppressor clones from immunologically unresponsive individuals with leprosy and was found to be necessary for suppression in vitro. Both the classic reciprocal relation between antibody formation and cell-mediated immunity and resistance or susceptibility to certain infections may be explained by T cell subsets differing in patterns of lymphokine production.
Pre-Bötzinger Complex: a Brainstem Region that May Generate Respiratory Rhythm in Mammals
Authors: Smith Jeffrey C. , Ellenberger Howard H. , Ballanyi Klaus , Richter Diethelm W , Feldman Jack L.
Published: October 2006

The location of neurons generating the rhythm of breathing in mammals is unknown. By microsection of the neonatal rat brainstem in vitro, a limited region of the ventral medulla (the pre-Bötzinger Complex) that contains neurons essential for rhythmogenesis was identified. Rhythm generation was eliminated by removal of only this region. Medullary slices containing the pre-Bötzinger Complex generated respiratory-related oscillations similar to those generated by the whole brainstem in vitro, and neurons with voltage-dependent pacemaker-like properties were identified in this region. Thus, the respiratory rhythm in the mammalian neonatal nervous system may result from a population of conditional bursting pacemaker neurons in the pre-Bötzinger Complex.
Widespread Expression of BDNF But Not NT3 by Target Areas of Basal Forebrain Cholinergic Neurons
Authors: Phillips Heidi S. , Hains Jeanne M. , Laramee Gary R. , Rosenthal Arnon , Winslow John W.
Published: October 2006

Brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) are homologs of the well-known neurotrophic factor nerve growth factor. The three members of this family display distinct patterns of target specificity. To examine the distribution in brain of messenger RNA for these molecules, in situ hybridization was performed. Cells hybridizing intensely to antisense BDNF probe were located throughout the major targets of the rat basal forebrain cholinergic system, that is, the hippocampus, amygdala, and neocortex. Strongly hybridizing cells were also observed in structures associated with the olfactory system. The distribution of NT3 mRNA in forebrain was much more limited. Within the hippocampus, labeled cells were restricted to CA2, the most medial portion of CA1, and the dentate gyrus. In human hippocampus, cells expressing BDNF mRNA are distributed in a fashion similar to that observed in the rat. These findings point to both basal forebrain cholinergic cells and olfactory pathways as potential central targets for BDNF.
Inhibition of Angiogenesis by Recombinant Human Platelet Factor-4 and Related Peptides
Authors: Maione Theodore E. , Gray Gary S. , Petro Joan , Hunt Anthony J. , Donner Amy L. , Bauer Susan I. , Carson Helen F. , Sharpe Richard J.
Published: October 2006

Recombinant human platelet factor-4 (rhPF4), purified from
Escherichia coli
, inhibited blood vessel proliferation in the chicken chorioallantoic membrane in a dose-dependent manner. Treatment of several cell types with rhPF4 in vitro suggested that the angiostatic effect was due to specific inhibition of growth factor-stimulated endothelial cell proliferation. The inhibitory activities were associated with the carboxyl-terminal, heparin-binding region of the molecule and could be abrogated by including heparin in the test samples, an indication that sulfated polysaccharides might modulate the angiostatic activity of platelet factor-4 in vivo. Understanding of the mechanisms of control of angiogenesis by endogenous proteins should facilitate the development of effective treatments for diseases of pathogenic neovascularization such as Kaposi's sarcoma, diabetic retinopathy, and malignant tumor growth.
Localization of an Acetylcholine Receptor Intron to the Nuclear Membrane
Authors: Berman Stephen A. , Bursztajn Sherry , Bowen Barbara , Gilbert Walter
Published: October 2006

The first intron of the RNA for the acetylcholine receptor (AChR) α subunit shows a ringlike distribution around nuclei in multinucleated myotubes by in situ hybridization. This pattern is not observed for an actin intron or U1 RNA. Quantitation of the intron sequences reveals large variations in the amount of both the AChR and actin introns between nuclei within the same myotube, although all nuclei express equivalent amounts of U1 RNA. This differential RNA expression indicates that nuclei can individually control expression of messenger RNAs. The restricted distribution of the AChR intron RNA suggests a previously unknown step in RNA processing.
Functional Evidence for an RNA Template in Telomerase
Authors: Shippen-Lentz Dorothy , Blackburn Elizabeth H.
Published: October 2006

The RNA moiety of the ribonucleoprotein enzyme telomerase from the ciliate
Euplotes crassus
was identified and its gene was sequenced. Functional analysis, in which oligonucleotides complementary to portions of the telomerase RNA were tested for their ability to prime telomerase in vitro, showed that the sequence 5′ CAAAACCCCAAA 3′ in this RNA is the template for synthesis of telomeric TTTTGGGG repeats by the
Euplotes
telomerase. The data provide a direct demonstration of a template function for a telomerase RNA and demarcate the outer boundaries of the telomeric template. Telomerase can now be defined as a specialized reverse transcriptase.
Tubules of Globoid Leukodystrophy: A Right-Handed Helix
Authors: Yunis Eduardo J. , Lee Robert E.
Published: October 2006

Morphologic similarity between the cytoplasmic tubules of globoid leukodystrophy and Gaucher's disease (as demonstrated by thin sectioning, negative staining, and shadowing techniques) and their resemblance to negatively stained beef cerebroside are presented as evidence favoring the accumulation of cerebrosides in globoid cells. The tubules of globoid leukodystrophy have a 60-angstrom periodic banding similar to the tubules of Gaucher's disease. A right-handed helical twisting of the tubules is observed in both diseases.
Absence of Cystathionase in Human Fetal Liver: Is Cystine Essential?
Authors: Sturman John A. , Gaull Gerald , Raiha Neils C. R.
Published: October 2006

Cystathionase activity is not measurable in the livers of 24 human fetuses and 3 premature infants, and the concentration of cystathionine in the liver is higher than that of the brain. The placenta does not subserve the transsulfuration function. Cystine (or cysteine) thus may be an essential amino acid in the immature human.
Ontogeny of the Estrogen Receptor during Early Uterine Development
Authors: Clark James H. , Gorski Jack
Published: October 2006

The number of estrogen binding sites in uterine cytoplasm on a per cell basis reaches a maximum by day 10 of life in both intact and castrate female rats. After this peak is reached, the number of binding sites per cell decreases, and the ratio remains constant until days 22 to 23 of life. Thus, the ontogeny of the estrogen binding protein is not dependent upon estrogen from the ovary and is probably an autonomous property of uterine cells. Sedimentation values and dissociation constants of the protein when the animals are 5 to 10 days of age are similar to those of the 22-day-old animal, indicating that the same protein is present throughout postnatal development.
Height and Weight at Menarche and a Hypothesis of Critical Body Weights and Adolescent Events
Authors: Frisch Rose E. , Revelle Roger
Published: October 2006

Height and weight at menarche were found for each subject in three longitudinal growth studies. Early and late maturing girls have menarche at the same mean weight, but late maturers are taller at menarche. Two other major events of adolescence, initiation of the weight growth spurt and maximum rate of weight gain, also occur at an invariant mean weight. The hypothesis is proposed that a critical body weight may trigger each of these adolescent events. Such an interaction would explain the secular trend to an earlier menarche.
Ozone and Vitamin E
Authors: Goldstein Bernard D. , Buckley Ramon D. , Cardenas Ramon , Balchum Oscar J.
Published: October 2006

Vitamin E deficiency in rats is associated with a greater susceptibility to lethal levels of ozone. Exposure of rats to sublethal ozone concentrations produces an accelerated decline in serum vitamin E levels. These findings are consistent with the possibility that lipid peroxidation is a mechanism of ozone toxicity.
Hemolysis Near an Ultrasonically Pulsating Gas Bubble
Authors: Rooney James A.
Published: October 2006

A small volume of an erythrocyte suspension was subjected to the action of a manipulated gas bubble set into stable oscillation at 20 kilohertz. Release of hemoglobin occurred when the oscillation amplitude exceeded a critical threshold. Hydrodynamic stresses resulting from acoustically induced small-scale eddying motion near the bubble may be the mechanism of hemolysis.
Intromission Pattern and Species Vaginal Code in Relation to Induction of Pseudopregnancy
Authors: Diamond Milton
Published: October 2006

Mechanical stimulation was used to mimic normal vaginal stimuli during copulation in the mouse; the number and rate of intromissions were crucial influences on reproductive success. The best combinations for the mechanical induction of pseudopregnancy were comparable to those male behaviors normally seen during mating. The behavior of the male coincides with a species-related vaginal code, increasing chances for reproductive success between cospecifics.
Bonds and Bands in Semiconductors
Authors: Phillips J. C.
Published: October 2006

Many of the most interesting developments in semiconductor physics that have occurred in the last few years and that are anticipated in the next few years appear to lie in the realm between physics and chemistry. In this article I have tried to show how this realm can be treated accurately and realistically within the framework of theory.
Triassic Tetrapods from Antarctica: Evidence for Continental Drift
Authors: Elliot David H. , Colbert Edwin H. , Breed William J. , Jensen James A. , Powell Jon S.
Published: October 2006

During the austral summer of 1969-1970 bones of Lower Triassic vertebrates were excavated from coarse quartzose sandstones forming stream channel deposits of the Fremouw Formation at Coalsack Bluff, in the Transantarctic Mountains of Antarctica. This is the first assemblage of fossil tetrapods of significant geologic age to be found on the Antarctic Continent. The fossils include labyrinthodont amphibians, presumed thecodont reptiles, and therapsid reptiles, including the definitive genus,
Lystrosaurus
. This genus is typical of the Lower Triassic of southern Africa, and is also found in India and China.
Lystrosaurus
and associated vertebrates found in Antarctica were land-living animals: therefore their presence on the South Polar Continent would seem to indicate the contiguity of Antarctica, Africa, and India in Early Triassic times.
Monosodium Glutamate: Feeding of Large Amounts in Man and Gerbils
Authors: Bazzano Gaetano , D'Elia John A. , Olson Robert E.
Published: October 2006

Oral administration of large amounts of glutamic acid to adult humans and animals in a formula diet appeared to cause no clinical pathological changes. The only biochemically demonstrable effect was a decrease in serum cholesterol and associated beta lipoproteins.
Temperature-Sensitive Neurons in the Brain of Brook Trout
Authors: Greer G. L. , Gardner D. R.
Published: October 2006

The brain temperature of trout (
Salvelinus fontinalis
) was altered by perfusion of the gills with warm or cool water. Neuronal activity was recorded with microelectrodes. Twelve neurons responded to an increase in temperature with increased activity, and five neurons responded to a decrease in temperature with an increase in activity.
Auditory Frequency-Following Response: Neural or Artifact?
Authors: Marsh James T. , Worden Frederic G. , Smith James C.
Published: October 2006

An electrical response which reproduces the waveform and frequency of the sound stimulus can be recorded from the central neural pathway for audition. Controversy has existed for some years over whether this frequency-following response (FFR) is neural or an artifact such as remote pickup of the cochlear microphonic or cross talk in the recording system. Two experiments resolve this issue by demonstrating that the frequency-following response depends upon functionally intact neural pathways. The frequency-following response, as well as auditory evoked potentials, is abolished by section of the eighth nerve; it is reversibly abolished by cooling of the cochlear nucleus.
LFA-3, CD44, and CD45: Physiologic Triggers of Human Monocyte TNF and IL-1 Release
Authors: Webb Deborah S. A. , Shimizu Yoji , Van Seventer Gijs A. , Shaw Stephen , Gerrard Theresa L.
Published: October 2006

The monocyte-derived cytokines, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), are central regulators of the immune response, but the physiologic stimuli for their release remain largely undefined. Engagement of three monocyte glycoproteins, LFA-3, CD44, and CD45, by specific monoclonal antibodies immobilized on plastic induced TNF-α and IL-1β release. In addition, TNF-α was released when monocyte LFA-3 bound immobilized, purified CD2, which is its physiologic receptor. Thus, a receptor-ligand interaction that mediates cell-cell adhesion can transmit the necessary signals for the release of monokines.
CD14, a Receptor for Complexes of Lipopolysaccharide (LPS) and LPS Binding Protein
Authors: Wright Samuel D. , Ramos Robert A. , Tobias Peter S. , Ulevitch Richard J. , Mathison John C.
Published: October 2006

Leukocytes respond to lipopolysaccharide (LPS) at nanogram per milliliter concentrations with secretion of cytokines such as tumor necrosis factor-α (TNF-α). Excess secretion of TNF-α causes endotoxic shock, an often fatal complication of infection. LPS in the bloodstream rapidly binds to the serum protein, lipopolysaccharide binding protein (LBP), and cellular responses to physiological levels of LPS are dependent on LBP. CD14, a differentiation antigen of monocytes, was found to bind complexes of LPS and LBP, and blockade of CD14 with monoclonal antibodies prevented synthesis of TNF-α by whole blood incubated with LPS. Thus, LPS may induce responses by interacting with a soluble binding protein in serum that then binds the cell surface protein CD14.
Spontaneous in vitro Neoplastic Transformation of Adult Human Prostatic Epithelium
Authors: Fraley Elwin E. , Ecker Sidney , Vincent Monroe M.
Published: October 2006

The possible significance of spontaneous transformation of epithelium from a benign prostatic adenoma containing glandular hyperplasia is discussed.
Substrate-Induced Conjugation of Bilirubin in Genetically Deficient Newborn Rats
Authors: Thaler M. Michael
Published: October 2006

Bilirubin appears to induce its own conjugation with glucuronide. Bilibrubin uridine diphosphate-glucuronyltransferase activity is relatively high at birth in heterozygous offspring of permanently jaundiced female rats. The postnatal development of the transferase is accelerated in hyperbilirubinemic heterozygotes.
Marine Sediments: Dating by the Racemization of Amino Acids
Authors: Bada Jeffrey L. , Luyendyk Bruce P. , Maynard J. Barry
Published: October 2006

Isoleucine has been found to undergo a slow racemization reaction in a 5-meter sediment core taken from the Atlantis fracture zone (water depth, 4014 meters; actual location, 30°15.7′N, 43°18.9′W). The amount of racemization increases with increasing depth below the sediment-seawater interface. This isoleucine racemization reaction was used to calculate an age of 1.23 million years for the bottom of the core.
Vascular Lesions: Possible Pathogenetic Basis of the Generalized Shwartzman Reaction
Authors: Gaynor Evelyn , Bouvier Claude , Spaet Theodore H.
Published: October 2006

Evidence of vascular injury was found in rabbits after a single small dose of endotoxin from
Escherichia coli.
Eighty percent of the treated animals developed circulating endothelial cells, leukopenia, and thrombocytopenia, and 50 percent had aortic endothelial lesions as determined by electron microscopy. Prior anticoagulation with heparin did not prevent this response. No control animals showed these abnormalities.
Centrifugal Effects in the Avian Retina
Authors: Miles F. A.
Published: October 2006

Electrical stimulation of the centrifugal fibers to the avian retina can disturb the balance between the excitatory and inhibitory system within the receptive fields of individual retinal ganglion cells. Although the mechanisms may vary from one unit to another, the effect is always to make them fire more readily and to a wider range of visual inputs.
Evoked Response and Behavior in Cats
Authors: Hall R. A. , Rappaport M. , Hopkins H. K. , Griffin R. , Silverman J.
Published: October 2006

Electroencephalographic averaged evoked responses to flashing lights of four different intensities were recorded in ten cats and correlated with behavior. Animals showing a high degree of exploratory behavior, aggressiveness, and activity and little withdrawal showed relatively large increases in amplitude of the averaged evoked response with increases of stimulus intensity. Those showing opposite behavioral traits had small increases or decreases of average evoked response amplitude with increases of stimulus intensity. These findings are compatible with those reported for human subjects. Inference is made about a neurophysiological mechanism for stimulus intensity modulation.
Microcytotoxicity Test: Detection in Sarcoma Patients of Antibody Cytotoxic to Human Sarcoma Cells
Authors: Wood William C. , Morton Donald L.
Published: October 2006

A microcytotoxicity test has been used to detect a factor cytotoxic for human sarcoma cells; the factor was found in serums from 70 percent of sarcoma patients, 58 percent of their family members, and 8 percent of serums from normal blood donors. This cytotoxin is an antibody against a common cell surface sarcoma antigen since it is specific for sarcoma cells, is complement dependent, and is extractable with the globulin fraction of serum.
Marihuana: Studies on the Disposition and Metabolism of Delta-9-Tetrahydrocannabinol in Man
Authors: Lemberger Louis , Silberstein Stephen D. , Axelrod Julius , Kopin Irwin J.
Published: October 2006

Δ9-Tetrahydrocannabinol (the major active component of marihuana) administered intravenously to normal human volunteers persists in plasma for more than 3 days (t1/2= 56 hours). Its metabolites appear in plasma within 10 minutes after administration and persist along with the precursor compound. Δ9-Tetrahydrocannabinol is completely metabolized in man, and the radioactive metabolites are excreted in urine and feces for more than 8 days.
Molecular Cloning and Functional Expression of the Cardiac Sarcolemmal Na
+
-Ca
2+
Exchanger
Authors: Nicoll Debora A. , Longoni Stefano , Philipson Kenneth D.
Published: October 2006

The Na
+
-Ca
2+
exchanger of the cardiac sarcolemma can rapidly transport Ca
2+
during excitation-contraction coupling. To begin molecular studies of this transporter, polyclonal antibodies were used to identify a complementary DNA (cDNA) clone encoding the Na
+
-Ca
2+
exchanger protein. The cDNA hybridizes with a 7-kilobase RNA on a Northern blot and has an open reading frame of 970 amino acids. Hydropathy analysis suggests that the protein has multiple transmembrane helices, and a small region of the sequence is similar to that of the Na
+
- and K
+
-dependent adenosine triphosphatase. Polyclonal antibodies to a synthetic peptide from the deduced amino acid sequence react with sarcolemmal proteins of 70, 120, and 160 kilodaltons on immunoblots. RNA, synthesized from the cDNA clone, induces expression of Na
+
-Ca
2+
exchange activity when injected into
Xenopus
oocytes.
Broadly Neutralizing Antibodies Elicited by the Hypervariable Neutralizing Determinant of HIV-1
Authors: Javaherian Kashi , Langlois Alphonse J. , LaRosa Greg J. , Profy Albert T. , Bolognesi Dani P. , Herlihy Walter C. , Putney Scott D. , Matthews Thomas J.
Published: October 2006

The principal neutralizing determinant (PND) of human immunodeficiency virus (HIV)-1 resides within the V
3
loop of the envelope protein. Antibodies elicited by peptides of this region were able to neutralize diverse isolates. Serum from one of three animals immunized with the human T cell lymphoma virus (HTLV)- III
MN
PND peptide, RP142, neutralized MN and the sequence-divergent HTLV- III
B
isolate. Serum from one of three animals immunized with a 13-amino acid III
B
PND peptide (RP337) also neutralized both of these isolates. Characterization of these sera revealed that the cross-neutralizing antibodies bound the amino acid sequence GlyProGlyArgAlaPhe (GPGRAF) that is present in both isolates. This sequence is frequently found in the PNDs analyzed in randomly selected HIV-1 isolates. Sera from two rabbits immunized with a peptide containing only the GPGRAF residues neutralized divergent isolates, including III
B
and MN.
Generation of cAMP-Activated Chloride Currents by Expression of CFTR
Authors: Anderson Matthew P. , Rich Devra P. , Gregory Richard J. , Smith Alan E. , Welsh Michael J.
Published: October 2006

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis. In order to evaluate its function, CFTR was expressed in HeLa, Chinese hamster ovary (CHO), and NIH 3T3 fibroblast cells, and anion permeability was assessed with a fluorescence microscopic assay and the whole-cell patch-clamp technique. Adenosine 3′,5′-monophosphate (cAMP) increased anion permeability and chloride currents in cells expressing CFTR, but not in cells expressing a mutant CFTR (ΔF508) or in nontransfected cells. The simplest interpretation of these observations is that CFTR is itself a cAMP-activated chloride channel. The alternative interpretation, that CFTR directly or indirectly regulates chloride channels, requires that these cells have endogenous cryptic, chloride channels that are stimulated by cAMP only in the presence of CFTR.
Magnetotactic Bacteria
Authors: Blakemore Richard
Published: October 2006

Bacteria with motility directed by the local geomagnetic field have been observed in marine sediments. These magnetotactic microorganisms possess flagella and contain novel structured particles, rich in iron, within intracytoplasmic membrane vesicles. Conceivably these particles impart to cells a magnetic moment. This could explain the observed migration of these organisms in fields as weak as 0.5 gauss.
Determination of Primary Motoneuron Identity in Developing Zebrafish Embryos
Authors: Eisen Judith S.
Published: October 2006

The developmental determination of primary motoneurons was investigated by transplanting identified motoneurons in embryonic zebrafish to new spinal cord positions. Some cells moved from the new positions in which they were placed back to their original positions, thus it was difficult to evaluate whether they were determined. Among cells that remained in their new positions, those transplanted about 1 hour before axogenesis developed axonal trajectories that were appropriate for their original soma positions, whereas those transplanted 2 to 3 hours before axogenesis developed morphologies appropriate for their new soma positions. These results suggest that motoneuronal identity is determined before axogenesis.
Urinary Adenosine 3′,5′-Monophosphate in the Switch Process from Depression to Mania
Authors: Paul Michael I. , Cramer Hinrich , Bunney William E.
Published: October 2006

Marked elevations of urinary adenosine 3′,5′-monophosphate occurred on the day of rapid switch from a depressed into a manic state in patients with manic-depressive illness. It is suggested that this increase might serve a trigger function for the process by which catecholamines are elevated during the manic phase of the illness.
Paradox of Enrichment: Destabilization of Exploitation Ecosystems in Ecological Time
Authors: Rosenzweig Michael L.
Published: October 2006

Six reasonable models of trophic exploitation in a two-species ecosystem whose exploiters compete only by depleting each other's resource supply are presented. In each case, increasing the supply of limiting nutrients or energy tends to destroy the steady state. Thus man must be very careful in attempting to enrich an ecosystem in order to increase its food yield. There is a real chance that such activity may result in decimation of the food species that are wanted in greater abundance.
Mental Rotation of Three-Dimensional Objects
Authors: Shepard Roger N. , Metzler Jacqueline
Published: October 2006

The time required to recognize that two perspective drawings portray objects of the same three-dimensional shape is found to be (i) a linearly increasing function of the angular difference in the portrayed orientations of the two objects and (ii) no shorter for differences corresponding simply to a rigid rotation of one of the two-dimensional drawings in its own picture plane than for differences corresponding to a rotation of the three-dimensional object in depth.
Eye Lens Color: Formation and Function
Authors: Zigman Seymour
Published: October 2006

Aromatic amino acids are photooxidized by near-ultraviolet light to colored products that are bound very tightly to protein amino groups. The resulting colored proteins absorb near-ultraviolet light more strongly and are rendered more hydrophobic than the untreated compounds, and they fluoresce at 440 nanometers when excited at 360 nanometers. Coloration in the lenses of diurnally active animals (including man) may be caused by this reaction, and senile cataracts may result. Such changes in many other proteins (as in the skin and retina) could lead to more serious consequences.
Visual Patterned Reflex Present during Hypothalamically Elicited Attack
Authors: Bandler Richard , Flynn John P.
Published: October 2006

A cat from which attack is elicited by electrical stimulation of the hypothalamus lunges more frequently toward a mouse presented to the eye contralateral to the stimulated site than it does to a mouse presented to the ipsilateral eye. This differential effect does not appear to be attributable to a temporary or permanent defect in the ipsilateral eye.
Chromosome Lesions Produced with an Argon Laser Microbeam without Dye Sensitization
Authors: Berns Michael W. , Cheng Wanny K. , Floyd Alton D. , Ohnuki Yasushi
Published: October 2006

Improvements in the argon laser microbeam have made it possible to cause damage to chromosomes of tissue culture cells without prior treatment of the cells with a photosensitizing agent. These results have been confirmed independently in two laboratories.
Ethacrynic Acid Effect on the Composition of Cochlear Fluids
Authors: Cohn Edward S. , Gordes Ellen H. , Brusilow Saul W.
Published: October 2006

Ethacrynic acid, when administered to six dogs, caused a fall in the concentration of potassium in endolymph from 145 to 21 milliequivalents per liter and a rise in the concentration of sodium from 5.9 to 146 milliequivalents per liter. The composition of perilymph is unaffected. Perilymph and endolymph are slightly hypertonic as compared to plasma.
Age-Associated Changes in the DNA of Mouse Tissue
Authors: Price Gerald B. , Modak S. P. , Makinodan T.
Published: October 2006

The template activity of DNA with calf thymus DNA polymerase has been studied in sections of fixed brain, liver, and heart tissues from young and senescent mice. The enzyme catalyzed greater incorporation of deoxyribonucleotide monophosphates into nuclei of old mouse neurons, astrocytes, Kupffer cells, and heart muscle fibers. The results are interpreted as the accumulation of DNA strand breaks with aging.
Tumor Detection by Nuclear Magnetic Resonance
Authors: Damadian Raymond
Published: October 2006

Spin echo nuclear magnetic resonance measurements may be used as a method for discriminating between malignant tumors and normal tissue. Measurements of spin-lattice (
T
1
) and spin-spin (
T
2
) magnetic relaxation times were made in six normal tissues in the rat (muscle, kidney, stomach, intestine, brain, and liver) and in two malignant solid tumors, Walker sarcoma and Novikoff hepatoma. Relaxation times for the two malignant tumors were distinctly outside the range of values for the normal tissues studied, an indication that the malignant tissues were characterized by an increase in the motional freedom of tissue water molecules. The possibility of using magnetic relaxation methods for rapid discrimination between benign and malignant surgical specimens has also been considered. Spin-lattice relaxation times for two benign fibroadenomas were distinct from those for both malignant tissues and were the same as those of muscle.
Altruism Is Rewarding
Authors: Weiss Robert Frank , Buchanan William , Altstatt Lynne , Lombardo John P.
Published: October 2006

People will learn an instrumental conditioned response, the reward for which is the deliverance of another human being from suffering.
Structural Features that Give Rise to the Unusual Stability of RNA Hairpins Containing GNRA Loops
Authors: Heus Hans A. , Pardi Arthur
Published: October 2006

The most frequently occurring RNA hairpins in 16
S
and 23
S
ribosomal RNA contain a tetranucleotide loop that has a GNRA consensus sequence. The solution structures of the GCAA and GAAA hairpins have been determined by nuclear magnetic resonance spectroscopy. Both loops contain an unusual G-A base pair between the first and last residue in the loop, a hydrogen bond between a G base and a phosphate, extensive base stacking, and a hydrogen bond between a sugar 2′-end OH and a base. These interactions explain the high stability of these hairpins and the sequence requirements for the variant and invariant nucleotides in the GNRA tetranucleotide loop family.
Recognition of a Cell-Surface Oligosaccharide of Pathogenic
Salmonella
by an Antibody Fab Fragment
Authors: Cygler Miroslaw , Rose David R. , Bundle David R.
Published: October 2006

The 2.05 angstrom (Å) resolution crystal structure of a dodecasaccharide-Fab complex revealed an unusual carbohydrate recognition site, defined by aromatic amino acids and a structured water molecule, rather than the carboxylic acid and amide side chains that are features of transport and other carbohydrate binding proteins. A trisaccharide epitope of a branched bacterial lipopolysaccharide fills this hydrophobic pocket (8 Å deep by 7 Å wide) in an entropy-assisted association (association constant = 2.05 × 10
5
liters per mole, enthalpy = -20.5 ± 1.7 kilojoules per mole, and temperature times entropy = +10.0 ± 2.9 kilojoules per mole). The requirement for the complementarity of van der Waals surfaces and the requirements of saccharide-saccharide and protein-saccharide hydrogen-bonding networks determine the antigen conformation adopted in the bound state.