bluuebunny/crossref_metadata_2025 huggingface dataset:
Cone Inputs to Ganglion Cells in Hereditary Retinal Degeneration
Authors: Cicerone Carol M. , Green Daniel G. , Fisher Leslie J.
Published: October 2006

The photoreceptor layer degenerated, but cone nuclei apparently devoid of outer segments were retained in retinas of aged rats of the Royal College of Surgeons strain from which optic tract activity was recorded. Measures of sensitivity showed these single axons of retinal ganglion cells to have photopic spectral responses. Cone remnants containing a cone pigment may be the photoreceptive elements in these retinas.
Multiple Sclerosis: Presence of Lymphatic Capillaries and Lymphoid Tissue in the Brain and Spinal Cord
Authors: Prineas John W.
Published: October 2006

Thin-walled channels resembling lymphatic capillaries and containing lymphocytes were observed in perivascular spaces throughout the central nervous system of patients with various neurological disorders. This suggests that immunological surveillance in the central nervous system may normally involve lymphocyte circulation through the perivascular compartment. In some old multiple sclerosis plaques, perivascular lymphoid tissue was found which was organized in a manner similar to the antibody-producing medullary region of lymph nodes. This may indicate continuous processing of the putative multiple sclerosis antigen in such lesions.
Dynamic Changes in Circulating 1,25-Dihydroxyvitamin D During Reproduction in Rats
Authors: Pike J. Wesley , Parker Jeffrey B. , Haussler Mark R. , Boass Agna , Toverud Svein U.
Published: October 2006

The concentrations of 1,25-dihydroxyvitamin D [1,25-(OH)
2
D], calcium, and phosphorus were measured in the serum of rats during pregnancy and at various stages of lactation. The concentration of 1,25-(OH)
2
D hormone increased almost twofold during pregnancy and the latter part of lactation, but decreased to control levels or very low values immediately after birth and weaning, respectively. Furthermore, the concentration of 1,25-(OH)
2
D was inversely correlated with the concentration of calcium, suggesting that circulating 1,25-(OH)
2
D fluctuates in concert with calcium demands during the reproductive cycle. Parathyroidectomy in lactating rats caused a 70 percent inhibition of the normally observed 1,25-(OH)
2
D increase, indicating that parathyroid hormone, in response to changes in serum calcium, is a primary modulator of 1,25-(OH)
2
D during lactation.
Should There Be a Commission on Medical Education?
Authors: Chapman Carleton B.
Published: October 2006

In its premedical and preclinical phases our present scheme of education for medicine is intellectually deficient, wasteful of money and time, and in urgent need of overhaul. The author defines conditions under which a national commission might possibly set the educational process on the road to reform.
Parabolic Flight: Loss of Sense of Orientation
Authors: Lackner James R. , Graybiel Ashton
Published: October 2006

On the earth, or in level flight, a blindfolded subject being rotated at constant velocity about his recumbent long body axis experiences illusory orbital motion of his body in the opposite direction. By contrast, during comparable rotation in the free-fall phase of parabolic flight, no body motion is perceived and all sense of external orientation may be lost; when touch and pressure stimulation is applied to the body surface, a sense of orientation is reestablished immediately. The increased gravitoinertial force period of a parabola produces an exaggeration of the orbital motion experienced in level flight. These observations reveal an important influence of touch, pressure, and kinesthetic information on spatial orientation and provide a basis for understanding many of the postural illusions reported by astronauts in space flight.
Conditioned Tolerance to the Hypothermic Effect of Ethyl Alcohol
Authors: Lê A. D. , Poulos Constantine X. , Cappell Howard
Published: October 2006

Results from experiments with rats support the proposition that tolerance to the hypothermic effect of alcohol involves the Pavlovian conditioning of compensatory responses. Tolerance was substantially reduced when alcohol was administered in an environment that had not been associated with alcohol. Direct evidence of a conditioned hyperthermic compensatory response was found.
A Direct Role of Dopamine in the Rat Subthalamic Nucleus and an Adjacent Intrapeduncular Area
Authors: Brown Lucy L. , Markman Maynard H. , Wolfson Leslie I. , Dvorkin B. , Warner Carolyn , Katzman Robert
Published: October 2006

The subthalamic nucleus, a clinically important component of the extrapyramidal motor system, and a lateral area extending into the peduncle contain catecholamine terminals and dopamine receptors coupled to adenylate cyclase. In addition, dopamine agonists administered in vivo enhance glucose utilization in the region. Thus, neuronal function in this region is directly affected by dopamine and dopaminergic drugs.
Genetic Resistance to Aflatoxin in Japanese Quail
Authors: Marks H. L. , Wyatt R. D.
Published: October 2006

Progress was rapid in attempts to develop lines of quail resistant to acute aflatoxicosis induced by oral dosing with aflatoxin. After five generations of selection, 8- and 11-fold differences were present in mortality between two selected lines and their respective control lines. These quail lines should be of value in investigating the physiological basis of resistance to aflatoxin.
Ultrasound Emission in Infant Rats as an Indicant of Arousal During Appetitive Learning and Extinction
Authors: Amsel Abram , Radek Cathryn C. , Graham Mike , Letz Richard
Published: October 2006

Infant rats rewarded for crawling by being allowed to suckle on the dry nipple of an anesthetized dam showed a decreasing rate of ultrasound production during acquisition and an increasing rate during extinction. These results suggest that infant rats can be stressed and are aroused as a result of successive nonrewards just as adult rats are. In addition, these results do not support the hypothesis that infant rats lack inhibitory mechanisms related to poorly developed neural centers.
Inherited Epilepsy: Spike-Wave and Focal Motor Seizures in the Mutant Mouse Tottering
Authors: Noebels Jeffrey L. , Sidman Richard L.
Published: October 2006

Mice with the mutant gene tottering (
tg
, chromosome 8, autosomal recessive) show, in adolescence, abnormal bursts of bilaterally synchronous spike waves as revealed in electrocorticograms recorded over long periods. The spike waves are accompanied by behavioral "absence" attacks and intermittent focal motor seizures showing somatotopic progression. Cerebral metabolic activity during seizures was assayed by autoradiography of brain sections from mice injected intravenously with
14
C-labeled 2-deoxyglucose. Metabolic activity was increased bilaterally in selected brainstem structures. Spontaneous electrocorticographic and clinical seizures of this general pattern were recognized hitherto only in humans.
Genetic Variance in Nonverbal Intelligence: Data from the Kinships of Identical Twins
Authors: Rose Richard J. , Harris E. L. , Christian J. C. , Nance W. E.
Published: October 2006

The multiple relationships within kinships of adult monozygotic twins permit incisive analyses to be made of genetic and environmental effects on behavioral traits. Data from families of 65 monozygotic twin pairs yield evidence of genetic variance on the Block Design Test, a nonverbal measure of general intelligence.
Ethanol Embryotoxicity: Direct Effects on Mammalian Embryos in Vitro
Authors: Brown Nigel A. , Goulding Eugenia H. , Fabro Sergio
Published: October 2006

Exposure to ethanol retards growth and differentiation in cultured rat embryos during organogenesis. The development of untreated embryos is indistinguishable from growth in utero. These data suggest that the hypoplastic features of children born to chronically alcoholic mothers are due, at least in part, to a direct action of ethanol, which causes reduced embryonic cellular proliferation early in gestation.
Neuroendocrine Response to Estrogen and Sexual Orientation
Authors: Gladue Brian A. , Green Richard , Hellman Ronald E.
Published: October 2006

A neuroendocrine component, the positive estrogen feedback effect, thought to be related to sexual orientation and, indirectly, to sexual differentiation, was evaluated in healthy, noninstitutionalized research volunteers. Men and women with a lifelong heterosexual orientation and men with a lifelong homosexual orientation were administered an estrogen preparation known to enhance the concentration of luteinizing hormone in women but not in men. The secretory pattern of luteinizing hormone in the homosexuals in response to estrogen was intermediate between that of the heterosexual men and that of the women. Furthermore, testosterone was depressed for a significantly longer period in the homosexual men than in the heterosexual men. These findings suggest that biological markers for sexual orientation may exist.
Three-Dimensional Molecular Modeling and Drug Design
Authors: Gund Peter , Andose Joseph D. , Rhodes Joe B. , Smith Graham M.
Published: October 2006

A discussion of drug-receptor theory is used to show that the three-dimensional structure, or shape, of molecules is important for biological activity. The computer-assisted molecular modeling system at Merck is described, and it is shown that this system is useful for generating and storing molecular structures, determining preferred conformation, comparing molecular shapes, and computing molecular properties. Applications of the system to the study of anti-inflammatory drugs, somatostatin-like compounds, and dihydrofolate reductase inhibitors are summarized.
Aspartate: Possible Neurotransmitter in Cerebellar Climbing Fibers
Authors: Wiklund Leif , Toggenburger Gerhard , Cuénod Michel
Published: October 2006

Autoradiography demonstrated prominent retrograde labeling of olivocerebellar climbing fiber neurons after injection of tritiated D-aspartate into the rat cerebellar cortex or deep nuclei. Mossy fiber systems originating in the brainstem and spinal cord remained unlabeled. Potassium ion-induced depolarization of cerebellar slices resulted in calcium ion-dependent release of endogenous L-aspartate, L-glutamate, γ-aminobutyric acid, and glycine. A 26 percent decrease in aspartate release was observed after 3-acetylpyridine-induced destruction of the inferior olive, supporting the hypothesis that aspartate is a neurotransmitter in climbing fibers.
Schizophrenia: Dopamine β-Hydroxylase Activity and Treatment Response
Authors: Sternberg D. E. , VanKammen D. P. , Lerner P. , Bunney W. E.
Published: October 2006

Cerebrospinal fluid levels of dopamine β-hydroxylase, found to be relatively constant over time in individual patients, were significantly lower in schizophrenic patients who became nonpsychotic during neuroleptic treatment than in those who remained psychotic. Dopamine β-hydroxylase activity may delineate a subgroup of patients who have a dopamine-sensitive brain disorder.
Quantitative Electron Microscopic Autoradiography of Insulin, Glucagon, and Somatostatin Binding Sites on Islets
Authors: Patel Yogesh C. , Amherdt Mylene , Orci Lelio
Published: October 2006

After monolayer cultures of rat islets were exposed to [
125
I]insulin, [
125
I]glucagon, and [
125
I]tyrosinyl somatostatin, specific autoradiographic grains associated with each radioactively labeled ligand were found on B, A, and D cells. The density of labeling of the B, A, and D cells with each labeled ligand correlated well with the known actions of the three hormones on each of the islet cells.
Induction of Hemoglobin Accumulation in Human K562 Cells by Hemin Is Reversible
Authors: Dean Ann , Erard Francois , Schneider Arthur B. , Schechter Alan N.
Published: October 2006

Twenty micromolar hemin causes no change in the rate of division of K562 cells but results in accumulation of 11 to 14 picograms of embryonic and fetal hemoglobins per cell. This effect is reversible, and hemoglobin induction in response to hemin, and loss of hemoglobin upon removal of hemin, can be cyclically repeated. The cells can be indefinitely subcultured in the presence of the inducer. Thus, the control of hemoglobin levels in K562 cells does not depend on irreversible differentiation.
Substance P and Cholecystokinin-Like Peptides in
Helix
Neurons and Cholecystokinin and Serotonin in a Giant Neuron
Authors: Osborne N. N. , Cuello A. C. , Dockray G. J.
Published: October 2006

Immunohistochemical procedures revealed that the serotonin-containing cell situated in each metacerebral ganglion of the snail Helix also contains a cholecystokinin-like peptide, but is devoid of substance P. In radioimmunoassays the cholecystokinin-like material showed similarities to the carboxy terminal regions of mammalian cholecystokinin and gastrin. Since much is known about the morphology and synaptic connections of this serotonin neuron, the role of the cholecystokinin-like peptides can now be investigated by neurophysiological methods, thus opening the way to discovering whether a neuron can use more than one transmitter.
Selective Reduction of Forskolin-Stimulated Cyclic AMP Accumulation by Inhibitors of Protein Synthesis
Authors: Brooker Gary , Pedone Carolyn , Barovsky Kenneth
Published: October 2006

Inhibiting protein synthesis by incubating C6-2B rat astrocytoma cells with cycloheximide or emetine for periods up to 24 hours caused a progressive decrease in the accumulation of adenosine 3′,5′-monophosphate (cyclic AMP) when the cells were challenged for 30 minutes with 100 μ
M
forskolin. In contrast, cholera toxin-stimulated (6 n
M
, 3 hours) cyclic AMP accumulation was not diminished in cycloheximide-treated cells, and cyclic AMP was only minimally diminished in response to a 30-minute challenge with 10 μ
M
(-)-isoproterenol. These experiments suggest the presence of a previously unrecognized cyclase component, which is essential for forskolin-stimulated cyclic AMP accumulation and has a shorter half-life than the β-adrenergic receptor, the guanine nucleotide regulatory proteins, or the cyclase catalytic component.
Far-Ultraviolet Stopped-Flow Circular Dichroism
Authors: Luchins J. , Beychok S.
Published: October 2006

A stopped-flow circular dichroism instrument, with a total accessible wavelength range of 200 to 750 nanometers, has been constructed and provides a spectroscopic method for kinetic investigations of a wide array of fast reactions in which optical activity changes in absorbing regions are involved. An important biochemical application depends on the far-ultraviolet capability, which allows observation of the rapid alterations in backbone conformation associated with folding and unfolding reactions of proteins. Results obtained by following two such reactions at 222 nanometers represent direct monitoring by circular dichroism of rapid secondary structure changes in proteins.
The Rôle of Epithelium in Experimental Immunization
Authors: Sewall Henry
Published: October 2006

When a small amount of blood serum is dropped into the nose of a guinea pig the serum is absorbed by the mucous membrane and, after a definite period of incubation, the animal can be shown to have become profoundly changed.

Depending upon the number of instillations, the interval between them and, especially, the quantity of serum instilled, the animal becomes either highly hypersensitive or strongly resistant to a toxic injection given by the vein. This resistance withstands a considerable series of increasing toxic injections and is strengthened with lapse of time,—contrary to the state of tolerance produced by traumatic methods.

It is inferred that the absorption of foreign protein by the nose causes the formation of two different antibodies. One of these is
allergic
and excites to anaphylaxis; the other is
protective
and leads to true immunity. The relative amount of either antibody can be regulated by modifying the amount of serum instilled.

Added to a state of general allergy it is easy to produce, in the guinea pig, a special sensitization of the respiratory apparatus which leads, under appropriate stimulation, to attacks resembling those of bronchial asthma in man.

No conclusion can be drawn at present concerning the nature or mode of action of the protective or immunizing antibody; but the indications are that its relations to the circulation and to tissue fixation resemble those which have been developed by other investigators in regard to the anaphylactic antibody.

Evidence has been submitted that the living epithelium mediates between foreign protein and the organism in a way to favor specifically the elaboration of true immunity.
The Engineer and Civilization
Authors: Durand W. F.
Published: October 2006

To sum up the whole matter, the engineer, either as an individual or as a collective type, is simply a link in the chain of human progress—a chain the links of which, in one form or another, run back into a past removed from our own time by tens of thousands of years, to go to no higher figures. With the trend of human progress as it now is, he seems, moreover, to be a very necessary link. He has taken upon himself the peculiar function of developing and translating into use for the needs of civilization the constructive materials of the earth and the inorganic energies of nature, and in connection with the exercise of such function he has acquired peculiar and weighty duties and responsibilities.
Arabinosylcytosine Induces Fetal Hemoglobin in Baboons by Perturbing Erythroid Cell Differentiation Kinetics
Authors: Papayannopoulou Thalia , Torrealba de Ron Ana , Veith Robert , Knitter G. , Stamatoyannopoulos G.
Published: October 2006

Arabinosylcytosine, a compound that inhibits DNA synthesis in rapidly dividing cells, stimulates fetal hemoglobin in adult baboons and produces significant perturbations in the pools of erythroid progenitors. It appears that changes in the kinetics of erythroid cell differentiation rather than direct action on the γ genes underlie stimulation of fetal hemoglobin in the adult animals in vivo. These results also suggest that chemotherapeutic agents selected for their low carcinogenic or mutagenic potential could be used for therapeutic induction of fetal hemoglobin in patients with sickle cell anemia.
Sequence of the Envelope Glycoprotein Gene of Type II Human T Lymphotropic Virus
Authors: Sodroski Joseph , Patarca Roberto , Perkins Dennis , Briggs Debra , Lee Tun-Hou , Essex Myron , Coligan John , Wong-Staal Flossie , Gallo Robert C. , Haseltine William A.
Published: October 2006

The sequence of the envelope glycoprotein gene of type II human T lymphotropic virus (HTLV) is presented. The predicted amino acid sequence is similar to that of the corresponding protein of HTLV type I, in that the proteins share the same amino acids at 336 of 488 residues, and 68 of the 152 differences are of a conservative nature. The overall structural similarity of these proteins provides an explanation for the antigenic cross-reactivity observed among diverse members of the HTLV retrovirus family by procedures that assay for the viral envelope glycoprotein, for example, membrane immunofluorescence.
Pituitary Gonadotropin-Releasing Hormone Receptors During the Rat Estrous Cycle
Authors: Savoy-Moore Ruth T. , Schwartz Neena B. , Duncan Joyce A. , Marshall John C.
Published: October 2006

The binding of [6-alanine]gonadotropin-releasing hormone to pituitary plasma membranes increased threefold between metestrus and early proestrus in female rats. Receptor numbers fell rapidly on the afternoon of proestrus coincident with the preovulatory gonadotropin surge. The numbers of receptors for gonadotropin-releasing hormone were positively correlated with concentrations of estradiol in serum; this pattern may be a necessary component of increased pituitary sensitivity to gonadotropin-releasing hormone observed during proestrus.
Outward Currents in Developing
Drosophila
Flight Muscle
Authors: Salkoff Lawrence , Wyman Robert
Published: October 2006

The development of two different voltage-sensitive potassium channels was studied in
Drosophila
flight muscle by voltage clamp techniques. Early in development active channels are not present in the membrane. The first channels to appear are the A current channels, which carry a fast, rapidly inactivating potassium current. The channels for delayed rectification appear later. Channels carrying inward current also appear only after the A current channels. During development, the A current may be easily studied in isolation from other currents and thus provides a desirable system for studying the genetic determinants of this current.
Prolactin and Growth Hormone Release by Morphine in the Rat: Different Receptor Mechanisms
Authors: Spiegel Katharyn , Kourides Ione A. , Pasternak Gavril W.
Published: October 2006

Concentrations of prolactin and growth hormone in the serum of rats were significantly increased by morphine. Dose response studies demonstrated that maximum prolactin release required lower doses of morphine than those needed for the maximum growth hormone response. Selective blockade of μ
1
(high affinity) opiate receptors with the irreversible antagonist naloxazone reduced morphine-induced peak concentrations of prolactin by 80 percent while increasing peak growth hormone levels by 250 percent. These results suggest different receptor mechanisms for the opiate modulation of the two hormones. The μ
1
(high affinity) receptor sites appear to mediate the morphine-induced release of prolactin but not growth hormone.
Physalaemin: An Amphibian Tachykinin in Human Lung Small-Cell Carcinoma
Authors: Lazarus L. H. , DiAugustine R. P. , Jahnke G. D. , Hernandez O.
Published: October 2006

Immunoreactivity to the amphibian peptide physalaemin was characterized from extracts of a human lung small-cell carcinoma by immunological, chemical, and pharmacological means. Tumor-related peptide cross-reacted with three antiserums to physalaemin to yield 1.1 to 1.6 nanomoles per gram of tissue. Physalaemin and tumor peptide had similar retention times on high-performance liquid chromatography after chemical and enzymic modifications that included
p
H changes, oxone oxidation, use of a hydrophilic ion-pairing reagent, and digestion with trypsin and pyroglutamate aminopeptidase. Both physalaemin and the tumor peptide produced a contractile response of isolated guinea pig ileum at threshold concentrations of approximately 100 to 150 picograms per milliliter. These data suggest that small-cell carcinoma of the lung contains a physalaemin-like peptide that has structural and biological homology to its amphibian counterpart.
Homologous Regulation of Gonadotropin-Releasing Hormone Receptors in Cultured Pituitary Cells
Authors: Loumaye Ernest , Catt Kevin J.
Published: October 2006

Specific receptors for gonadotropin-releasing hormone (GnRH) in cultured rat pituitary cells were increased by subnanomolar concentrations of GnRH agonists and decreased by high concentrations of these peptides. The antagonist [D-Phe
2
, Pro
3
, D-Phe
6
]GnRH did not alter GnRH binding capacity and blocked the increase in sites induced by GnRH. These findings provide direct evidence for the homologous regulation of GnRH receptors by physiological concentrations of the hypothalamic peptide, an action that could mediate the cyclical and postcastration increases in GnRH receptors and responsiveness of the pituitary gonadotrophs.
Intracellular Calcium Measurements with Arsenazo III During Cyclic AMP Injections into Molluscan Neurons
Authors: Hockberger Phil , Connor John A.
Published: October 2006

Injections of cyclic adenosine monophosphate into molluscan neurons often produce a transient membrane depolarization. By using the calcium indicator dye arsenazo III, it was found that cyclic nucleotide injections into neurons of
Archidoris montereyensis
resulted in elevation of internal calcium concentrations. However, this was demonstrated to be a secondary consequence of an induced increase in membrane sodium permeability, and not due to any direct effect of cyclic adenosine monophosphate on cellular calcium influx or internal calcium regulating processes.
Colchicine Alters the Nerve Birefringence Response
Authors: Landowne David , Larsen James B. , Taylor Kevin T.
Published: October 2006

The internal perfusion of squid axons with colchicine reversibly and selectively reduces the transient sodium current and the birefringence response to a brief depolarizing voltage pulse.
Potassium Currents in
Drosophila
: Different Components Affected by Mutations of Two Genes
Authors: Wu Chun-Fang , Ganetzky Barry , Haugland Frank N. , Liu An-Xi
Published: October 2006

Electrophysiological analysis of the
Drosophila
behavioral mutants
Eag
and
Sh
and the double mutant
Eag
Sh
indicates that the products of both genes take part in the control of potassium currents in the membranes of both nerve and muscle. In voltage-clamped larval muscle fibers,
Sh
affects the transient A current, whereas
Eag
reduces the delayed rectification and, to a lesser extent, the A current.
Modulation of Synapse Formation by Cyclic Adenosine Monophosphate
Authors: Nirenberg M. , Wilson S. , Higashida H. , Rotter A. , Krueger K. , Busis N. , Ray R. , Kenimer J. G. , Adler M.
Published: October 2006

Synapses between neuroblastoma-hybrid cells and myotubes exhibit a high degree of plasticity. Increase of cyclic adenosine monophosphate (AMP) levels of the hybrid cells for several days results in the appearance of functional voltage-sensitive Ca2+ channels, which are required for evoked secretion of acetylcholine. The results show that cyclic AMP regulates synaptogenesis by regulating the expression of voltage-sensitive Ca2+ channels, and suggest that cyclic AMP affects posttranslational modifications of some glycoproteins and cellular levels of certain proteins.
Drug and Neurotransmitter Receptors in the Brain
Authors: Snyder Solomon H.
Published: October 2006

Biochemical investigation of receptors for neurotransmitters and drugs in the brain has been one of the most active areas of molecular neuroscience during the past decade. This work has permitted fundamental insights into how binding of neurotransmitters to their receptors excites or inhibits neuronal firing or changes cellular metabolism. The recognition of receptor subtypes has suggested subtle ways for neurotransmitters to modulate neuronal functioning. Finally, the ability to measure receptor sites in simple test tube systems and to distinguish readily between agonists and antagonists has provided useful probes for drug discovery programs.
Plasmodium falciparum
Maturation Abolishes Physiologic Red Cell Deformability
Authors: Cranston Hope A. , Boylan Charles W. , Carroll Gregory L. , Sutera Salvatore P. , Williamson Joseph R. , Gluzman Ilya Y. , Krogstad Donald J.
Published: October 2006

Normal red cells deform markedly as they pass through the spleen and the peripheral capillaries. In these studies, the effects of
Plasmodium falciparum
infection and maturation on the deformability of parasitized red cells exposed to fluid shear stress in vitro were examined by means of a rheoscope. Red cells containing the early (ring) erythrocytic stage of the parasite have impaired deformability at physiologic shear stresses, and recover their normal shape more slowly. Red cells containing more mature parasites (trophozoites or schizonts) exhibit no deformation under the same conditions. These results provide a mechanism to explain the ability of the spleen to remove parasitized red cells from the circulation of both immune and nonimmune hosts.
Essential Role of Insulin in Transcription of the Rat 25,000 Molecular Weight Casein Gene
Authors: Chomczynski Piotr , Qasba Pradman , Topper Yale J.
Published: October 2006

Insulin is essential for the accumulation of rat casein messenger RNA (mRNA) in the presence of glucocorticoid and prolactin. The accumulation of certain mRNA's in other tissues has also been linked to insulin action. The present study shows that the accumulation effect on the 25,000 molecular weight rat casein mRNA does not reflect stabilization of the transcript by insulin. Rather, insulin is essential for its synthesis in the presence of glucocorticoid and prolactin.
Human Brain Tumor—Derived Cell Lines: Growth Rate Reduced by Human Fibroblast Interferon
Authors: Cook Albert W. , Carter William A. , Nidzgorski Florence , Akhtar Longina
Published: October 2006

The biological response modifier human β-interferon had pronounced antigrowth effects on various histologic types of human brain tumor cells but no effects on a nontransformed cell line, MRC-5. The cultures of brain tumor cells showed severe alterations indicative of cell injury and death after exposure to β-interferon for 2 to 6 days. Similar results were obtained with cells freshly explanted from human brain tumors. The results indicate that it may be possible to use fresh, explanted tumor tissue to identify patients who might benefit from therapy with β-interferon.
Blood Cell Surface Changes in
Drosophila
Mutants with Melanotic Tumors
Authors: Rizki T. M. , Rizki Rose M.
Published: October 2006

When wheat germ agglutinin conjugated to fluorescein isothiocyanate is bound to hemocytes from larvae of
Drosophila melanogaster
, two populations of hemocytes are distinguished. One shows a fluorescent speckled surface (spk
+
) and the other lacks this characteristic (spk
-
). In mutant larvae with melanotic tumors and in larval hosts with heterospecific implants, most of the lamellocytes (a hemocyte variant involved in capsule formation and tissue rejection) are spk
+
, whereas the lamellocytes in nontumorous larvae are spk
-
. This suggests that spk
+
lamellocytes are necessary for encapsulation of aberrant tissues in the mutant larvae and are responsible for rejection of foreign tissue implants.
Virus-Like Sensitivity of the Scrapie Agent to Heat Inactivation
Authors: Rohwer Robert G.
Published: October 2006

The resistance of the infectious agent of scrapie disease to sterilization at 100° or 121°C is reputed to be inconsistent with the structure of conventional viruses. However, in kinetic studies the majority of hamster scrapie strain 263K infectivity was (like that of previously characterized viruses) rapidly inactivated at temperatures of 100°C or greater. Small resistant subpopulations remained. Similar heat-resistant subpopulations were observed at 60°C for phage λ but only in the presence of brain homogenate. Brain homogenate may also confer stability to small subfractions of scrapie infectivity. Such refractory subpopulations cannot be used to make structural inferences that are properly obtained from the behavior of the majority population as revealed in the initial inactivation.
Toxicant-Disease-Environment Interactions Associated with Suppression of Immune System, Growth, and Reproduction
Authors: Porter Warren P. , Hinsdill Ronald , Fairbrother Anne , Olson Leon John , Jaeger James , Yuill Thomas , Bisgaard Søren , Hunter William G. , Nolan Katherine
Published: October 2006

The effects of marginal malnourishment, infections, and environmental chemicals on growth and reproductive success in Swiss-Webster white mice and wild deer mice were studied with fractional factorial designs. Interaction effects were discovered. For example, malnourished mice were more sensitive to virus exposure and environmental chemicals (a plant growth regulator or polychlorinated biphenyls). Since several commercial plant growth regulators also appear to suppress the immune system, these results cast doubt on the adequacy of current toxicity testing procedures in which factors are studied individually and not in combination.
Neurophysiological Evidence for a Traveling Wave in the Amphibian Inner Ear
Authors: Hillery Cynthia M. , Narins Peter M.
Published: October 2006

In response to low-frequency sounds (less than 1.0 kilohertz) auditory nerve fibers in the treefrog,
Eleutherodactylus coqui
, discharge at a preferred phase of the stimulus waveform which is a linear function of the stimulus frequency. Moreover, the slopes of the phase-versus-frequency functions (equivalent to the system time delays) systematically increase as the characteristic frequency of the fibers decreases. These neurophysiological observations, coupled with the known tonotopy of the amphibian papilla suggest that a traveling wave occurs in the inner ear of frogs despite the absence of a basilar membrane. Electrical tuning may contribute to these characteristic frequency-dependent delays.
Sulfation and Phosphorylation of the Neural Cell Adhesion Molecule, N-CAM
Authors: Sorkin Barbara C. , Hoffman Stanley , Edelman Gerald M. , Cunningham Bruce A.
Published: October 2006

Embryonic chicken brain tissue cultured in media containing
35
S-labeled sulfate or
32
P-labeled phosphate incorporated
35
S or
32
P into the neural cell adhesion molecule (N-CAM). The
35
S label was located in asparagine-linked carbohydrates on both glycopeptides (molecular weights, 170,000 and 140,000) but not in the sialic acid. The
32
P label was detected in phosphoamino acids in the carboxyl-terminal third of both polypeptides, but the ratio of phosphoserine to phosphothreonine differed in the two species. The sulfated saccharides and phosphoamino acids may provide additional sites for functional control of N-CAM.
Rapid Expulsion of
Trichinella spiralis
in Suckling Rats
Authors: Appleton J. A. , McGregor D. D.
Published: October 2006

Orally administered
Trichinella spiralis
muscle larvae were rapidly expelled by rat pups suckling an immune dam. The immunity was delivered in the milk; substantial resistance was conferred on normal rat pups suckled for only 24 hours by a
Trichinella
-immune foster mother. The pups were protected by oral or systemic administration of specific serum antibodies. When infused into a normal lactating dam, these antibodies accumulated in the serum of her suckling pups.
The Source of Solar Energy
Authors: Menzel Donald H.
Published: October 2006

While I have wandered from the main subject of the sun, to consider the source of stellar energy, the two topics are so intimately related that their solutions are identical. I consider that I have demonstrated the reasonableness of Jeans's theory by the manner in which it seems to fit the observed facts. There is, as I can see, no important objection to the hypothesis. It is too much to hope that the foregoing analysis is rigidly complete, but I confidently believe that the main points are established and that further modification will consist in the clearing up of details. The application of astrophysics and atomic theory to a new field appears to have met with considerable success. In spite of this success, however, caution is necessary. The present position of the theory advocated in this paper is somewhat analogous to the place once held by the theory of Helmholtz—
i.e.,
it is the only one sufficiently elastic to stretch over the region of known facts. Our knowledge is yet limited and, with our vision thus impaired, we can not predict the future. Some unforeseen event may upset our present hypothesis as completely as that of Helmholtz; we have built as securely as possible upon observation, and it remains for the future to test the accuracy of this or any other theory so established.

In an attempt to discover a reasonable explanation of the origin and duration of the solar radiation, all possible sources of energy are examined. The following hypotheses are reviewed and discarded, the arguments against their validity being too well known to necessitate a review at this place; (1) Original Heat; (2) Chemical; (3) Gravitational, (a) Meteoric, (b) Contraction; (4) Radioactive.
Intrinsic Mechanisms of Pain Inhibition: Activation by Stress
Authors: Terman Gregory W. , Shavit Yehuda , Lewis James W. , Cannon J. Timothy , Liebeskind John C.
Published: October 2006

Portions of the brain stem seem normally to inhibit pain. In man and laboratory animals these brain areas and pathways from them to spinal sensory circuits can be activated by focal stimulation. Endogenous opioids appear to be implicated although separate nonopioid mechanisms are also evident. Stress seems to be a natural stimulus triggering pain suppression. Properties of electric footshock have been shown to determine the opioid or nonopioid basis of stress-induced analgesia. Two different opioid systems can be activated by different footshock paradigms. This dissection of stress analgesia has begun to integrate divergent findings concerning pain inhibition and also to account for some of the variance that has obscured the reliable measurement of the effects of stress on tumor growth and immune function.
A Conformationally Constrained Vasopressin Analog with Antidiuretic Antagonistic Activity
Authors: Skala Gerald , Smith Clark W. , Taylor Catherine J. , Ludens James H.
Published: October 2006

Application of information derived from a three-dimensional model of vasopressin bound to its antidiuretic receptor resulted in the design and synthesis of a bicyclic vasopressin analog, [5,8-
cyclo
(1-β-mercaptopropionic acid,2-phenylalanine,5-aspartic acid,8-lysine)]vasopressin. The analog acts as an antagonist of the antidiuretic activity of vasopressin.
Balantidia from Pigs and Guinea-Pigs: Their Viability, Cyst Production and Cultivation
Authors: Rees C. W.
Published: October 2006

It has been shown that trophozoites of balantidia from the pig are normal in appearance and reactions when the medium is cooled to room temperature. They may live at room temperature for ten days. Trophozoites that infect the pig may pass through the stomach of the guinea-pig and reach the cecum, where they are normal after eighteen hours. Trophozoites are frequently passed in feces by the pig but cyst production is irregular and determined by unknown factors as in monkeys, guinea-pigs and man. The fluid of pig feces from the cecum is slightly hypertonic to blood serum. The method of Barret and Yarbrough for the cultivation of
Balantidium coli
has been found practicable for
Balantidium
from the pig and guinea-pig. The addition of rice starch improves the medium and Ringer's solution without dextrose was found more suitable than 0.5 per cent. NaCl solution. Loeffler's beef blood serum may be substituted for human serum or horse serum. H
2
S appears non-toxic to
Balantidium
from the pig when passed into culture tubes.
Identification of the Receptor for Antigen and Major Histocompatibility Complex on Human Inducer T Lymphocytes
Authors: Meuer Stefan C. , Cooper David A. , Hodgdon James C. , Hussey Rebecca E. , Fitzgerald Kathleen A. , Schlossman Stuart F. , Reinherz Ellis L.
Published: October 2006

Human T cell clones and monoclonal antibodies directed at their surface structures were used to define the receptor for the antigen and major histocompatibility complex on inducer T lymphocytes. The results indicated that the receptor is a single complex consisting of the monomorphic T3 molecule with a molecular weight of 20,000 to 25,000 and a clonotypic disulfide linked heterodimer Ti with a molecular weight of 90,000. Sepharose-bound monoclonal antibodies (anti-Ti
4
or anti-T3) to the receptor could activate clonal proliferation and inducer function for B cell immunoglobulin secretion and thus substitute for the appropriate combination of major histocompatibility complex gene product and specific antigen.
A Microtubule Meshwork Associated with Gametic Pronucleus Transfer Across a Cell-Cell Junction
Authors: Orias Judith D. , Hamilton Eileen P. , Orias Eduardo
Published: October 2006

In conjugating
Tetrahymena
, a cellular assembly composed of a microtubule meshwork appears to be required for the transfer of gametic pronuclei across the junction that separates the conjugating cells. This assembly is suggestive of a gametogenic cell division in ancient predecessors of ciliates, with
Tetrahymena
retaining only the associated nuclear division and export.
Homeostasis of the Antibody Response: Immunoregulation by NK Cells
Authors: Abruzzo Lynne V. , Rowley Donald A.
Published: October 2006

When injected into mice, the synthetic double-stranded polynucleotide poly(inosinic) ⋅ poly(cytidylic) acid induces high natural killer (NK) cell activity within 4 to 12 hours. Induction of NK activity in mice immunized 2 or 3 days previously, or the addition of NK cells to cultures immunized in vitro 2 or 3 days previously, promotes early termination of the ongoing primary immunoglobulin M antibody response. A target for NK cells is a population of accessory cells that has interacted with antigen and is necessary for sustaining the antibody response. The inference is strong that NK cells induced normally by immunization also terminate the usual antibody response in vivo by elimination of antigen-exposed accessory cells.
Task-Relevant Late Positive Component of the Auditory Event-Related Potential in Monkeys Resembles P300 in Humans
Authors: Arthur D. Lee , Starr Arnold
Published: October 2006

A long-latency (300-millisecond), vertex-positive component of the event-related potential recorded from monkeys was present only when the eliciting stimulus was relevant to the task. The amplitude of this component varied inversely with stimulus probability and was dissociable from motor responses.
Identification of an Erythrocyte Component Carrying the Duffy Blood Group Fy
a
Antigen
Authors: Hadley Terence J. , David Peter H. , McGinniss Mary H. , Miller Louis H.
Published: October 2006

The erythrocyte component carrying the Duffy blood group antigen Fy
a
has been identified as a 35- to 43-kilodalton protein. The protein is degraded by proteases, chymotrypsin, and Pronase, which destroy its antigenicity on intact erythrocytes. Its unusual property of aggregating on being boiled in 5 percent sodium dodecyl sulfate with 5 percent 2-mercaptoethanol distinguishes it from other erythrocyte membrane proteins described to date.
Perfluorochemical Emulsions Can Increase Tumor Radiosensitivity
Authors: Teicher Beverly A. , Rose Christopher M.
Published: October 2006

An oxygen-carrying perfluorochemical emulsion enhanced the effectiveness of radiation therapy in two transplantable solid tumors in mice. The perfluorochemical emulsion had no effect on tumor growth after x-irradiation, but delayed tumor growth significantly when administered to oxygen-breathing mice before or during irradiation.
American School of Prehistoric Research
Authors: MacCurdy George Grant
Published: October 2006

Of the eleven students taking part, about half were unable to remain for the entire term; these were permitted to join for short periods. In addition to the student body, permission was granted thirty-four other persons interested in our work to take part in our program—especially in Brittany and the Dordogne.

Of the fifty conferences given, twenty were by the director and thirty by twenty-eight specialists. To the latter, the director desires to express his deep sense of appreciation. Sixty-three important prehistoric sites and thirty-five museums and special collections were examined. As a result of the twenty-five days of digging, collections were sent to seven contributing institutions. At the end of the season five students remained in the Old World for further study and field work.
Blood Pressure and Nutrient Intake in the United States
Authors: McCarron David A. , Morris Cynthia D. , Henry Holly J. , Stanton John L.
Published: October 2006

A data base of the National Center for Health Statistics, Health and Nutrition Examination Survey I (HANES I), was used to perform a computer-assisted, comprehensive analysis of the relation of 17 nutrients to the blood pressure profile of adult Americans. Subjects were 10,372 individuals, 18 to 74 years of age, who denied a history of hypertension and intentional modification of their diet. Significant decreases in the consumption of calcium, potassium, vitamin A, and vitamin C were identified as the nutritional factors that distinguished hypertensive from normotensive subjects. Lower calcium intake was the most consistent factor in hypertensive individuals. Across the population, higher intakes of calcium, potassium, and sodium were associated with lower mean systolic blood pressure and lower absolute risk of hypertension. Increments of dietary calcium were also negatively correlated with body mass. Even though these correlations cannot be accepted as proof of causation, they have implications for future studies of the association of nutritional factors and dietary patterns with hypertension in America.
Reexamination of Acoustic Evidence in the Kennedy Assassination
Authors:   Committee on Ballistic Acoustics, National Research Council
Published: October 2006

Sounds recorded in Dallas at the time of the assassination of John F. Kennedy were analyzed by two research groups, whose reports formed the basis for the opinion that two gunmen fired at President Kennedy. These reports and the acoustic evidence have been studied by the Committee on Ballistic Acoustics, and further acoustic analyses, including sound spectrograms, have been performed. The committee finds that the acoustic data do not support a conclusion that a second gunman was involved in the assassination.
Reversible Chemical Modification of the Scrapie Agent
Authors: McKinley Michael P. , Masiarz Frank R. , Prusiner Stanley B.
Published: October 2006

The scrapie agent causes a degenerative nervous system disease in sheep and goats. Studies with extensively purified preparations demonstrated that the agent contains a protein that is required for infectivity. Chemical modification of the scrapie agent by diethyl pyrocarbonate reduced the titer 1000-fold. Exposure of the inactivated agent to hydroxylamine, a strong nucleophile, resulted in complete restoration of infectivity. Presumably, nucleophilic residues within a scrapie agent protein undergo carbethoxylation on reaction with diethyl pyrocarbonate, and subsequent addition of hydroxylamine displaces these carbethoxy groups.
Cytoplasmic Calcium in the Mediation of Macula Densa Tubulo-Glomerular Feedback Responses
Authors: Bell P. Darwin , Navar L. Gabriel
Published: October 2006

Within each nephron of the mammalian kidney, a feedback mechanism operating between the macula densa segment of the distal tubule and the afferent arteriole participates in the regulation of glomerular filtration rate. Retrograde microperfusion studies in rats were conducted to test the hypothesis that activation of macula densa cytoplasmic calcium is involved in the transmission of feedback signals to the vascular elements. Perfusion into distal tubules with a hypotonic solution (70 milliosmolar) elicited moderate decreases in glomerular pressure of 6 ± 0.8 millimeters of mercury. With the addition of a calcium ionophore (A23187) glomerular pressure decreased by 16 ± 1.1 millimeters of mercury. When a solution devoid of calcium but containing A23187 was used, the feedback response was inhibited. Thus, cytoplasmic calcium within the receptor cells may participate in the transmission of feedback signals to the contractile cells.
Cholinergic Innervation in Neuritic Plaques
Authors: Struble Robert G. , Cork Linda C. , Whitehouse Peter J. , Price Donald L.
Published: October 2006

Although several studies of Alzheimer's disease suggest that the frequency of neuritic plaques in the cerebral cortex is correlated with the severity of dementia and with reduction in presynaptic cholinergic markers in the cortex, the relationship between cholinergic cortical innervation and the pathogenesis of plaques is unknown. The hypothesis was tested that the neurites in the plaque consist, in part, of presynaptic cholinergic axons, many of which arise from neurons in the basal forebrain. This hypothesis was tested by analyzing the character and distribution of plaques in monkeys, aged 4 to 31 years, with staining for acetylcholinesterase and also with Congo red and silver stains. Immature and mature plaques were rich in acetylcholinesterase. As the plaques matured, the amount of amyloid increased, and the number of neurites and the activity of acetylcholinesterase decreased. End-stage amyloid-rich plaques lacked acetylcholinesterase. These observations indicate that changes in cortical cholinergic innervation are an important feature in the pathogenesis and evolution of the neuritic plaque.