bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple Circadian Oscillators Regulate the Timing of Behavioral and Endocrine Rhythms in Female Golden Hamsters
Authors: Swann Jennifer M. , Turek Fred W.
Published: October 2006

A single daily "surge" in pituitary luteinizing hormone release was observed in ovariectomized-estrogen-treated hamsters expressing an intact circadian rhythm of locomotor activity. In contrast, two luteinizing hormone surges occurred within a single 24-hour period in hamsters whose activity rhythm had dissociated or "split" into two distinct components. These observations indicate that both behavioral and endocrine circadian rhythms are regulated by the same multioscillator system, which seems to be composed of at least two distinct circadian oscillators.
Measles Virus Matrix Protein Synthesized in a Subacute Sclerosing Panencephalitis Cell Line
Authors: Sheppard Rachel D. , Raine Cedric S. , Bornstein Murray B. , Udem Stephen A.
Published: October 2006

Measles virus generally produces acute illness. Rarely, however, persistent infection of brain cells occurs, resulting in a chronic and fatal neurological disease, subacute sclerosing panencephalitis (SSPE). Evidence indicates that expression of the measles virus matrix protein is selectively restricted in this persistent infection, but the mechanism underlying this restriction has not been identified. Defective translation of matrix messenger RNA has been described in one SSPE cell line. This report presents evidence that in a different SSPE tissue culture cell line IP-3-Ca, the matrix protein is synthesized but fails to accumulate. A general scheme is proposed to reconcile the different levels at which restriction of matrix protein has been observed.
Antennal Hair Erection in Male Mosquitoes: A New Mechanical Effector in Insects
Authors: Nijhout H. Frederik , Sheffield Harley G.
Published: October 2006

Male
Anopheles
mosquitoes erect their antennal hairs prior to mating. The erectile mechanism resides in a unique annulus at the base of each hair whorl. It appears that the insect regulates the degree of hydration of this annulus. When the annulus is made to swell the attached hairs are pushed to their erect position.
Induction of Autoimmune Thyroiditis in Chickens by Dietary Iodine
Authors: Bagchi N. , Brown T. R. , Urdanivia E. , Sundick R. S.
Published: October 2006

Clinical studies have suggested that excess dietary iodine promotes autoimmune thyroiditis; however, the lack of a suitable animal model has hampered investigation of the phenomenon. In this study, different amounts of potassium iodide were added to the diets of chicken strains known to be genetically susceptible to autoimmune thyroiditis. Administration of iodine during the first 10 weeks of life increased the incidence of the disease, as determined by histology and the measurement of autoantibodies to triiodothyronine, thyroxine, and thyroglobulin. Further support for the relation between iodine and autoimmune thyroiditis was provided by an experiment in which iodine-deficient regimens decreased the incidence of thyroid autoantibodies in a highly susceptible strain. These results suggest that excessive consumption of iodine in the United States may be responsible for the increased incidence of autoimmune thyroiditis.
Polychlorinated Biphenyls: Penetration into the Deep Ocean by Zooplankton Fecal Pellet Transport
Authors: Elder D. L. , Fowler Scott W.
Published: October 2006

High concentrations of polychlorinated biphenyls (PCB's) were found in fecal pellets from natural populations of euphausiids collected in the Ligurian Sea. Since biogenic particulate products, especially fecal pellets, are known to sink rapidly and intact to the ocean bottom, the transport of PCB's by such sinking particles could be an important mechanism which contributes to the penetration of PCB's into the deep sea.
Peptide Neurotoxins from Fish-Hunting Cone Snails
Authors: Olivera Baldomero M. , Gray William R. , Zeikus Regina , McIntosh J. Michael , Varga Janos , Rivier Jean , de Santos Victoria , Cruz Lourdes J.
Published: October 2006

To paralyze their more agile prey, the venomous fish-hunting cone snails (
Conus
) have developed a potent biochemical strategy. They produce several classes of toxic peptides (conotoxins) that attack a series of successive physiological targets in the neuromuscular system of the fish. The peptides include presynaptic ω-conotoxins that prevent the voltage-activated entry of calcium into the nerve terminal and release of acetylcholine, postsynaptic α-conotoxins that inhibit the acetylcholine receptor, and muscle sodium channel inhibitors, the μ-conotoxins, which directly abolish muscle action potentials. These distinct peptide toxins share several common features: they are relatively small (13 to 29 amino acids), are highly cross-linked by disulfide bonds, and strongly basic. The fact that they inhibit sequential steps in neuromuscular transmission suggests that their action is synergistic rather than additive. Five new ω-conotoxins that block presynaptic calcium channels are described. They vary in their activity against different vertebrate classes, and also in their actions against different synapses from the same animal. There are susceptible forms of the target molecule in peripheral synapses of fish and amphibians, but those of mice are resistant. However, the mammalian central nervous system is clearly affected, and these toxins are thus of potential significance for investigating the presynaptic calcium channels.
The Quality of Medical Care
Authors: Donabedian Avedis
Published: October 2006

This article classifies the major approaches to the assessment of the process and outcomes of medical care. The apparent need to safeguard and enhance the quality of care has led to the institution of mechanisms that subject care to constant review so that deficiencies may be found and corrected. The article reviews the developments that led to the involvement of the federal government in this activity through its sponsorship of professional standards review organizations (PSRO's). The major features of the PSRO's are described and their possible effects discussed. It is too early to say how the PSRO's will fare, but should they fail to accomplish their objectives the pressure for more radical solutions will be difficult to resist.
Potent Antidopaminergic Activity of Estradiol at the Pituitary Level on Prolactin Release
Authors: Raymond Vincent , Beaulieu Michele , Labrie Fernand , Boissier Jacques
Published: October 2006

Prior incubation of rat anterior pituitary cells with 17β-estradiol led to an almost complete reversal of the inhibitory effect of two dopamine agonists, dihydroergocornine and RU 24213, on both basal prolactin release and thyrotropin releasing hormone-induced prolactin release. These experiments thus demonstrate a direct interference of dopamine action by a peripheral hormone. Prolactin secretion by pituitary cells in primary culture could possibly serve as an easily accessible model of a system under dopaminergic control.
Sensitization in
Aplysia
: Restoration of Transmission in Synapses Inactivated by Long-Term Habituation
Authors: Carew Thomas , Castellucci Vincent F. , Kandel Eric R.
Published: October 2006

Long-term habituation of a simple withdrawal reflex in
Aplysia
leads to an inactivation of synaptic transmission between identified sensory and gill motor neurons that persists for more than 3 weeks. A single sensitizing stimulus rapidly reactivates both the depressed behavioral response and the inactivated synaptic transmission. Thus sensitization, a simple competitive form of learning, provides a mechanism whereby changing environmental demands can rapidly override the long-term memory of habituation.
Menopausal Flushes: a Neuroendocrine Link with Pulsatile Luteinizing Hormone Secretion
Authors: Casper R. F. , Yen S. S. C. , Wilkes M. M.
Published: October 2006

Menopausal flush episodes were found to be invariably associated with the initiation of pulsatile pituitary release of luteinizing hormone. This was not accompanied by a significant change in circulating catecholamine or prolactin concentrations. Since pulsatile luteinizing hormone release results from episodic secretion of luteinizing hormone releasing factor by the hypothalamus, these findings suggest a link between the neuroendocrine mechanisms that initiate such episodic secretion and those responsible for the onset of flush episodes.
Subfornical Organ Efferents to Neural Systems for Control of Body Water
Authors: Miselis Richard R. , Shapiro Robert E. , Hand Peter J.
Published: October 2006

The subfornical organ, a circumventricular structure of the central nervous system, has efferent neural projections to sites within the brain known to be involved in drinking behavior and secretion of antidiuretic hormone. By using anterograde tracing techniques, it is shown that the subfornical organ projects to the nucleus medianus of the medial preoptic area, to the organum vasculosum of the lamina terminalis, and to the supraoptic nuclei bilaterally. Its efferent connectivity is confirmed by retrograde transport of horseradish peroxidase. The organum vasculosum of the lamina terminalis, another circumventricular organ and a suspected receptor site for angiotensin II, is involved in the circuitry of the subfornical organ and also has an efferent projection to the supraoptic nuclei.
N
-Nitrosamines in the Rubber and Tire Industry
Authors: Fajen J. M. , Carson G. A. , Rounbehler D. P. , Fan T. Y. , Vita R. , Goff U. E. , Wolf M. H. , Edwards G. S. , Fine D. H. , Reinhold V. , Biemann K.
Published: October 2006

Airborne
N
-nitrosomorpholine (0 to 27 micrograms per cubic meter) was found in two of four rubber industry factories.
N
-Nitrosodimethylamine was also found in two factories, but at lower levels. These findings may be relevant to the reported increased risk of certain types of cancer in rubber workers in some of the same areas where the
N
-nitrosomorpholine levels were highest.
Light and Efferent Activity Control Rhabdom Turnover in
Limulus
Photoreceptors
Authors: Chamberlain Steven C. , Barlow Robert B.
Published: October 2006

Photosensitive membrane structures in the retinular cells of the
Limulus
lateral eye are broken down and renewed daily. The first light onset causes a rapid, synchronous disassembly and buildup of the rhabdom in each photoreceptor cell. The entire process is complete within 30 minutes. Blocking the efferent input to the retina from the brain blocks the turnover of the rhabdom, and mimicking the efferent input by optic nerve stimulation restores it.
Tetanus Toxin: Direct Evidence for Retrograde Intraaxonal Transport
Authors: Price Donald L. , Griffin Jack , Young Ann , Peck Keith , Stocks Adelaine
Published: October 2006

The neurotoxin tetanospasmin causes tetanus when it reaches the central nervous system. In this autoradiographic study,
125
I-labeled tetanospasmin was injected into the leg muscles of rodents, and the nerves supplying these muscles were crushed. The labeled toxin accumulated within axons on the distal side of the crush. This study provides direct evidence for retrograde axonal transport of a macromolecular toxin that acts at synapses in the central nervous system.
Monosodium Glutamate Administration to the Newborn Reduces Reproductive Ability in Female and Male Mice
Authors: Pizzi William J. , Barnhart June E. , Fanslow Don J.
Published: October 2006

Monosodium glutamate (MSG) administered during the neonatal period (days 2 to 11) resulted in a sequence of events that were manifested in adulthood. Reproductive dysfunction was seen in both female and male animals. Females treated with MSG had fewer pregnancies and smaller litters, while males treated with MSG showed reduced fertility. The MSG-treated mice showed increased body weight and decreased pituitary, thyroid, ovary, or testis weights.
Formation of Mutagens in Beef and Beef Extract During Cooking
Authors: Commoner Barry , Vithayathil Antony J. , Dolara Piero , Nair Subhadra , Madyastha Prema , Cuca Gregory C.
Published: October 2006

Mutagens, distinguishable from benzo[
a
]pyrene and from mutagenic amino acid and protein pyrolysis products, are formed when ground beef is cooked in a home hamburger cooking appliance or when beef stock is concentrated, by boiling, to a paste known commercially as beef extract. "Well-done" hamburgers contain about 0.14 part per million of the mutagens, and beef bouillon cubes which contain beef extract about 0.1 part per million. Since such mutagens may be potentially carcinogenic and are formed during ordinary cooking procedures, their occurrence raises questions about possible risks to human health.
Histidine-Rich Protein as a Model Malaria Vaccine
Authors: Kilejian Araxie
Published: October 2006

Ducklings were successfully immunized against
Plasmodium lophurae
with a purified and characterized histidine-rich protein as antigen. The use of adjuvant is not required for this protective effect, and immunity can be passively transferred with serum.
Sex Pheromone in the Dog
Authors: Goodwin M. , Gooding K. M. , Regnier F.
Published: October 2006

Methyl
p
-hydroxybenzoate has been identified in the vaginal secretions of female dogs in estrus. When small amounts of this compound were applied to the vulvas of anestrous or spayed females, males placed with these females became sexually aroused and attempted to mount them.
Protein Deficiency and Tribal Warfare in Amazonia: New Data
Authors: Chagnon Napoleon A. , Hames Raymond B.
Published: October 2006

Increasing numbers of anthropological studies about native Amazonian warfare and demographic practices attempt to explain these phenomena as competition over or a response to scarce game animals and other sources of high-quality protein. Recently completed field research among the Yanomamö Indians living at the Venezuela-Brazil border indicates that their protein intake is comparable to that found in highly developed industrialized nations and as much as 200 percent more than many nutritional authorities recommend as daily allowances. Recent data on other Amazonian tribes likewise fails to indicate a correlation between protein intake and intensity of warfare patterns.
Lung Maturation in the Fetal Rat: Acceleration by Injection of Fibroblast-Pneumonocyte Factor
Authors: Smith Barry T.
Published: October 2006

Fibroblast-pneumonocyte factor, produced by the fetal lung fibroblast in response to glucocorticoids, was partially purified by column chromatography on Sephadex G-75. The resulting preparation showed two major and two minor bands on sodium dodecylsulfate-polyacrylamide gel electrophoresis. When fetal rats were injected on day 17 of gestation with 1 microgram of this material, they showed on day 20 biochemical evidence of accelerated lung maturation as compared to littermate controls. There were no differences between the two groups in body weights, organ weights, or circulating corticosteroid levels.
Identification of DNA Sequence Responsible for 5-Bromodeoxyuridine-Induced Gene Amplification
Authors: Biswas Debajit K. , Hartigan Jennifer A. , Pichler Mark H.
Published: October 2006

Bromodeoxyuridine (BrdUrd) treatment of the prolactin nonproducing subclone of GH cells (rat pituitary tumor cells) induces amplification of a 20-kilobase DNA fragment including all of the prolactin gene coding sequences. This amplified DNA segment, which is flanked by two unamplified regions, thus designates a unit of BrdUrd-induced amplified sequence. Cloned DNA segments, 10.3 kilobases long, from the 5′ end of the rat prolactin gene of BrdUrd-responsive and -nonresponsive cells, were ligated to the thymidine kinase gene of herpes simplex virus type 1 (HSV1TK), and the hybrid DNA was transferred to thymidine kinase-deficient mouse fibroblast cells by transfection. The HSV1TK gene and the rat prolactin gene were amplified together in drug-treated transfectants carrying the hybrid DNA HSV1TK gene and rat prolactin gene of BrdUrd-responsive GH cells. These results suggest that the 10.3-kilobase DNA segment at the 5′ end of the rat prolactin gene of BrdUrd-responsive GH cells carries the information for drug-induced gene amplification (amplicon) and that another gene, such as the HSV1TK gene, is also amplified when the latter is placed adjacent to this segment.
Cigarette Smoke Contains Anticoagulants Against Fibrin Aggregation and Factor XIIIa in Plasma
Authors: Galanakis Dennis K. , Laurent Phillip , Janoff Aaron , Chung Soo I.
Published: October 2006

Gas-phase, water-soluble components of cigarette smoke cause delayed fibrin self-assembly and prevent fibrin cross-linking by inactivation of factor XIIIa (plasma transglutaminase). These anticoagulant properties of smoke are demonstrable in plasma, suggesting they play a role in the pathophysiology of smoking.
Pancreatic Islet-Acinar Cell Interaction: Amylase Messenger RNA Levels Are Determined By Insulin
Authors: Korc Murray , Owerbach David , Quinto Carmen , Rutter William J.
Published: October 2006

Pancreatic amylase messenger RNA progressively decreases in rats rendered diabetic with streptozotocin. Insulin reverses this effect, inducing a selective increase in amylase messenger RNA in the pancreas. Parotid amylase messenger RNA is not significantly affected by either diabetes or insulin.
Relaxation of Isolated Gastric Smooth Muscle Cells by Vasoactive Intestinal Peptide
Authors: Bitar K. N. , Makhlouf G. M.
Published: October 2006

Vasoactive intestinal peptide caused a prompt, dose-dependent relaxation of isolated gastric smooth muscle cells of the guinea pig and a significant increase in intracellular adenosine 3′,5′-monophosphate coincidentally with optimum relaxation. Relaxation was augmented by a threshold concentration of isobutyl methylxanthine. The direct relaxant effect of vasoactive intestinal peptide and the distribution of nerves containing this peptide to circular smooth muscle support the view that vasoactive intestinal peptide is the neuromuscular transmitter of enteric inhibitory nerves.
Diverse Mechanisms in the Generation of Human β-Tubulin Pseudogenes
Authors: Wilde C. D. , Crowther C. E. , Cowan N. J.
Published: October 2006

The sequence of two human β-tubulin pseudogenes is described. One contains an intervening sequence but lacks sequences encoding the 55
N
-terminal amino acids of the polypeptide chain. A second has no introns but has a polyadenylate signal and an oligoadenylate tract at its 3′ end, and it is flanked by a short direct repeat. These sequences have arisen by different mechanisms, including one that probably involves reverse transcription of a processed messenger RNA and reintegration of the complementary DNA copy into the genome.
Clustering of Leukocyte and Fibroblast Interferon Genes of Human Chromosome 9
Authors: Shows Thomas B. , Sakaguchi Alan Y. , Naylor Susan L. , Goedell David V. , Lawn Richard M.
Published: October 2006

At least ten leukocyte interferon genes and the single known fibroblast interferon gene have been localized on the pter→q12 region of human chromosome 9. Gene mapping was accomplished by blot hybridizations of cloned interferon complementary DNA to DNA from human-mouse cell hybrids with a translocation involving human chromosome 9. Supporting evidence suggests these genes are clustered.
Transported Proteins in the Regenerating Optic Nerve: Regulation by Interactions with the Optic Tectum
Authors: Benowitz Larry I. , Yoon Myong G. , Lewis Ellen R.
Published: October 2006

The transport of specific proteins in regenerating optic fibers of goldfish depends on the presence or absence of the optic tectum. When optic fibers were allowed to contact the tectum, amounts of rapidly transported proteins having molecular weights between 120,000 and 160,000 increased, and a species of molecular weight 26,000 reverted to normal levels. When nerves were prevented from contacting the tectum, the amount of the 26,000-molecular weight protein remained high for months. Amounts of other transported proteins, in particular a group of acidic components of molecular weight 44,000 to 49,000 that increase greatly at early stages of regeneration, proved to be independent of the tectum.
Frequent Detection and Isolation of Cytopathic Retroviruses (HTLV-III) from Patients with AIDS and at Risk for AIDS
Authors: Gallo Robert C. , Salahuddin Syed Z. , Popovic Mikulas , Shearer Gene M. , Kaplan Mark , Haynes Barton F. , Palker Thomas J. , Redfield Robert , Oleske James , Safai Bijan , White Gilbert , Foster Paul , Markham Phillip D.
Published: October 2006

Peripheral blood lymphocytes from patients with the acquired immunodeficiency syndrome (AIDS) or with signs or symptoms that frequently precede AIDS (pre-AIDS) were grown in vitro with added T-cell growth factor and assayed for the expression and release of human T-lymphotropic retroviruses (HTLV). Retroviruses belonging to the HTLV family and collectively designated HTLV-III were isolated from a total of 48 subjects including 18 of 21 patients with pre-AIDS, three of four clinically normal mothers of juveniles with AIDS, 26 of 72 adult and juvenile patients with AIDS, and from one of 22 normal male homosexual subjects. No HTLV-III was detected in or isolated from 115 normal heterosexual subjects. The number of HTLV-III isolates reported here underestimates the true prevalence of the virus since many specimens were received in unsatisfactory condition. Other data show that serum samples from a high proportion of AIDS patients contain antibodies to HTLV-III. That these new isolates are members of the HTLV family but differ from the previous isolates known as HTLV-I and HTLV-II is indicated by their morphological, biological, and immunological characteristics. These results and those reported elsewhere in this issue suggest that HTLV-III may be the primary cause of AIDS.
HTLV-III in the Semen and Blood of a Healthy Homosexual Man
Authors: Ho David D. , Schooley Robert T. , Rota Teresa R. , Kaplan Joan C. , Flynn Theresa , Salahuddin Syed Z. , Gonda Matthew A. , Hirsch Martin S.
Published: October 2006

Human T-lymphotropic virus type III (HTLV-III) is the probable etiologic agent for the acquired immune deficiency syndrome (AIDS). HTLV-III was isolated from semen and blood of a healthy homosexual man whose serum contains antibodies to HTLV-III. The finding of virus in semen supports epidemiologic data that suggest that AIDS can be transmitted sexually. In addition, the demonstration of HTLV-III in the blood and semen of a healthy individual establishes an asymptomatic, virus-positive carrier state which may be important in the dissemination of HTLV-III and, consequently, AIDS.
Lymphoid Cell-Glioma Cell Interaction Enhances Cell Coat Production by Human Gliomas: Novel Suppressor Mechanism
Authors: Dick Steven J. , Macchi Beatrice , Papazoglou Savvas , Oldfield Edward H. , Kornblith Paul L. , Smith Barry H. , Gately Maurice K.
Published: October 2006

Certain human glioma lines produce mucopolysaccharide coats that impair the generation of cytolytic lymphocytes in response to these lines in vitro. Coat production is substantially enhanced by the interaction of glioma cells with a macromolecular factor released by human peripheral blood mononuclear cells in culture. This interaction thus constitutes an unusual mechanism by which inflammatory cells may nonspecifically suppress the cellular immune response to at least one class of solid tumors in humans.
Tumor-Promoting Phorbol Esters Stimulate Hematopoietic Colony Formation in Vitro
Authors: Stuart Robert K. , Hamilton John A.
Published: October 2006

Tumor-promoting phorbol esters stimulated mouse bone marrow cells to form myeloid colonies in agar cultures without added colony-stimulating factors. The colony-stimulating ability of various phorbol esters correlated well with their ability to promote skin tumors in vivo. These results suggest that phorbol esters mimic the action of specific colony-stimulating factors that regulate growth.
Beta-Adrenergic-Receptor Localization by Light Microscopic Autoradiography
Authors: Palacios Jose M. , Kuhar Michael J.
Published: October 2006

β-Receptors were identified in rat brain by a light microscopic autoradiographic technique. The procedure involved binding
3
H-labeled dihydroalprenolol to β-receptors in intact slide-mounted tissue sections and generating autoradiograms by the apposition of emulsion-coated cover slips, Biochemical analysis of the binding indicated that these conditions provided a high degree of selective labeling of β-receptors. High densities of receptors were found in superficial layers of the cerebral cortex, throughout the caudate-putamen, in the periventricular nucleus of the thalamus, in the molecular layer of the cerebellum, and in other areas. These results are in agreement with other electrophysiological and histochemical data. This radiohistochemical approach should be an important addition to other methods for mapping functional catecholamine neuronal pathways and sites of hormonal action.
(-)Pentobarbital Opens Ion Channels of Long Duration in Cultured Mouse Spinal Neurons
Authors: Mathers David A. , Barker Jeffery L.
Published: October 2006

Intracellular recordings from voltage-clamped mouse spinal neurons in tissue culture were used to study the membrane mechanisms underlying inhibitory responses to γ-aminobutyric acid and the (-) isomer of pentobarbital. Fluctuation analysis suggested that both substances activated ion channels in the membranes. However, the channels activated by pentobarbital remained open five times longer than those activated by γ-aminobutyric acid.
Glucose Suppresses Basal Firing and Haloperidol-Induced Increases in the Firing Rate of Central Dopaminergic Neurons
Authors: Saller Charles F. , Chiodo Louis A.
Published: October 2006

In the rat, doses of glucose sufficient to raise glucose concentrations in the blood to levels equivalent to those produced by a meal or stress suppress the firing of dopamine-containing neurons located within the substantia nigra. Glucose also prevents or reverses the increase in discharge rates of dopaminergic cells normally elicited by the antipsychotic agent haloperidol.
Interaction Between Purine and Benzodiazepine: Inosine Reverses Diazepam-Induced Stimulation of Mouse Exploratory Behavior
Authors: Crawley Jacqueline N. , Marangos Paul J. , Paul Steven M. , Skolnick Phil , Goodwin Frederick K.
Published: October 2006

Inosine, 2-deoxyinosine, and 2-deoxyguanosine completely reversed the increase in exploratory activity elicited in mice by diazepam. The inhibition of exploratory behavior by purines occurred at doses that when given alone have no effect on exploratory behavior. 7-Methylinosine, which does not bind to the brain benzodiazepine binding site in vitro, had no effect on the diazepam-induced increase in exploratory behavior. Behavioral effects produced by various combinations of inosine and diazepam indicate that the interaction between purine and benzodiazepine is antagonistic and support the hypothesis that the naturally occurring purines function in anxiety-related behaviors that respond to benzodiazepine treatment.
Growth Factors Modulate Gonadotropin Receptor Induction in Granulosa Cell Cultures
Authors: Mondschein Judith S. , Schomberg David W.
Published: October 2006

Epidermal growth factor and fibroblast growth factor inhibited follicle-stimulating hormone-dependent induction of luteinizing hormone receptor in cultured ovarian granulosa cells of the rat. In contrast, platelet-derived growth factor potentiated the induction of luteinizing hormone receptor by follicle-stimulating hormone. These results indicate that growth factors, well known for their effects on mitosis and DNA synthesis in cultured mammalian cells, are also able to modulate hormone-dependent differentiation in an endocrine target cell.
Neural Gonadal Steroid Actions
Authors: McEwen Bruce S.
Published: October 2006

Neurons sensitive to gonadal steroids are located strategically within neural circuits that mediate behaviors broadly related to the reproductive process. Some neuronal events and properties are regulated by these hormones. Variability in the occurrence and distribution of particular neural hormonal sensitivities across species may be related to variations in the hormonal requirements for sexual differentiation and for activation of reproductive behaviors.
Epileptogenic Agents Enhance Transmission at an Identified Weak Electrical Synapse in
Aplysia
Authors: Rayport Stephen G. , Kandel Eric R.
Published: October 2006

To examine the possibility that alterations in the effectiveness of electrical synapses might participate in epileptogenesis, the effects of several convulsants on an identified weak electrical synapse in
Aplysia
were examined. Application of pentylenetetrazole, strychnine, or tetraethylammonium led to a dramatic increase in the size of the electrical postsynaptic potential mediated by the synapse; penicillin was considerably less effective. In a number of animals, the increased electrical synaptic effectiveness led to the abnormal conduction of spikes across the synapse. If convulsants have a similar action in mammalian cortex, enhanced transmission at weak electrical synapses may provide abnormal pathways for the flow of seizure activity and contribute in part to the synchronous firing of neurons characteristic of epileptic activity.
Suppression of Transcription Termination by Phage Lambda
Authors: Ward Douglas F. , Gottesman Max E.
Published: October 2006

The bacteriophage lambda
N
gene product positively controls development by preventing termination of transcription at terminator sites critical to the sequential expression of phage genes. Many host transcription factors, including RNA polymerase, are involved in
N
gene action. Recent findings have shown that ribosomal proteins are also involved. The current understanding of how the
N
protein affects transcription termination is reviewed, and a possible model and current problems are discussed.
Nucleotide Sequence of the Transforming Gene of Avian Myeloblastosis Virus
Authors: Rushlow Keith E. , Lautenberger James A. , Papas Takis S. , Baluda Marcel A. , Perbal Bernard , Chirikjian Jack G. , Reddy E. Premkumar
Published: October 2006

Avian myeloblastosis virus is defective in reproductive capacity, requiring a helper virus to provide the viral proteins essential for synthesis of new infectious virus. This virus arose by recombination of the nondefective helper virus and host cellular sequences present within the normal avian genome. These latter sequences are essential for leukemogenic activity. The complete nucleotide sequence of this region is reported. Within the acquired cellular sequences there is an open reading frame of 795 nucleotides starting with the initiation codon ATG (adenine, thymine, guanine) and terminating with the triplet TAG. This open reading frame could code for the putative transforming protein of 265 amino acids with a molecular weight of approximately 30,000.
Cellular Transforming Genes
Authors: Cooper Geoffrey M.
Published: October 2006

Cellular genes potentially capable of inducing oncogenic transformation have been identified by homology to the transforming genes of retroviruses and by the biological activity of cellular DNA's in transfection assays. DNA's of various tumors induce transformation with high efficiencies, indicating that oncogenesis can involve dominant genetic alterations resulting in activation of cellular transforming genes. The identification and characterization of cellular transforming genes and their possible involvement in naturally occurring cancers, is discussed.
Merging of Modalities in the Optic Tectum: Infrared and Visual Integration in Rattlesnakes
Authors: Hartline Peter H. , Kass Leonard , Loop Michael S.
Published: October 2006

The optic tectum of pit vipers (Crotalinae) contains a layer of infrared-sensitive neurons subjacent to the visual layer; these indirectly receive input from the facial pit organs. They respond transiently to the appearance or motion of warm objects within their 25° to 70° excitatory receptive fields (some have inhibitory regions) and presumably allow the snake to orient or strike toward prey. The infrared and visual spatiotopic tectal maps have similar but not identical axes; the infrared magnification is greater than that for vision. Bimodal neurons have receptive fields for each modality that reflect the disparity of the two maps. This finding suggests that (i) during development the infrared and visual fibers spread out independently to fill available tectal sites and (ii) bimodal neurons form local connections without regard to establishing spatial correspondence between the two modalities.
Anti-Inflammatory Steroids Without Pituitary-Adrenal Suppression
Authors: Lee Henry J. , Soliman Magdi R. I.
Published: October 2006

When two new steroids, methyl prednisolonate and methyl 20-dihydroprednisolonate, were applied locally their anti-inflammatory activities were nearly equivalent to those of the parent compound prednisolone in the cotton pellet granuloma bioassay. However, when these two derivatives were administered systemically, their anti-inflammatory activities were weaker than those of the parent compound. Furthermore, unlike the parent compound, these new anti-inflammatory steroids did not suppress pituitary-adrenal function or cause liver glycogen depletion in rats.
Demonstration of a Saturable Binding Site for Thyrotropin in
Yersinia enterocolitica
Authors: Weiss Mordechai , Ingbar Sidney H. , Winblad Sten , Kasper Dennis L.
Published: October 2006

Several lines of evidence suggest that there might be immunologic cross-reactivity between the thyroid plasma membrane in humans and antigenic determinants in the enteric pathogen
Yersinia enterocolitica
. Studies were therefore performed to determine whether
Y. enterocolitica
, like the thyroid membrane, contains a thyrotropin binding site. A saturable binding site for bovine thyrotropin was indeed demonstrable, particularly in preparations of the organism that have been treated with ethylenediaminetetraacetate and lysozyme. Hormonal specificity of the binding site, as judged from the inhibition of binding of
125
I-labeled bovine thyrotropin, was similar to that of the thyrotropin receptor in human thyroid tissue.
Herpes Simplex Virus Glycoprotein D: Human Monoclonal Antibody Produced by Bone Marrow Cell Line
Authors: Seigneurin J. M. , Desgranges C. , Seigneurin D. , Paire J. , Renversez J. C. , Jacquemont B. , Micouin C.
Published: October 2006

Normal bone marrow cells from a donor positive for herpes simplex virus were transformed with Epstein-Barr virus. The resulting lymphoblastoid cell line has secreted immunoglobulin G
1
of the κ type continuously for 2 years. This immunoglobulin, detected both on the cell surface and in the cytoplasm, reacts with cells infected with herpes simplex virus. It defines an antigen that comigrates with the 55-kilodalton glycoprotein D of herpes simplex virus type 1 and neutralizes the infectivity of herpes simplex viruses 1 and 2.
Deformed Whiskers in Mice Infected with Certain Exogenous Murine Leukemia Viruses
Authors: Rowe Wallace P.
Published: October 2006

Mice infected at birth with replication competent Friend, Moloney, CasBr-M, C2S-M, and 1504-A murine leukemia viruses developed abnormalities of the vibrissae consisting of erratic curvature, shortening, and loss. A number of other virus strains, as well as endogenous AKR-type ecotropic virus and AKR-type, mink cell focus-inducing (MCF) viruses, did not produce these abnormalities. In mice with erythroid and myeloid leukemia, the perivibrissal sinus is the site of extramedullary hematopoiesis, but this did not appear to be the basis of the deformities. Genetic evidence indicated that newly arisen MCF-type recombinant viruses are involved in the pathogenesis of the abnormalities, at least with some of the virus systems studied.
Identification of Pro-Opiomelanocortin-Derived Peptides in the Human Adrenal Medulla
Authors: Evans Christopher J. , Erdelyi Elizabeth , Weber Eckard , Barchas Jack D.
Published: October 2006

Extracts from adult human adrenals contained high concentrations of immunoreactive β-endorphin and α-melanotropin. Lower quantities of immunoreactive adrenocorticotropic hormone could also be detected. Distribution studies showed the presence of pro-opiomelanocortin fragments in the adrenal medulla. No α-melanotropin, β-endorphin, or adrenocorticotropic hormone could be found in adrenal extracts from several other mammalian species. Analysis of the β-endorphin-like immunoreactivity using region specific radioimmunoassays interfacing with gel filtration and reverse-phase high-performance liquid chromatography showed the majority of the β-endorphin-like material to exist as nonacetylated β-endorphin-(1-31) with a small percentage of lipotropin-sized molecules. The α-melanotropin-like immunoreactivity cochromatographed on gel filtration and reverse-phase high-performance liquid chromatography with desacetyl α-melanotropin. The data suggest that pro-opiomelanocortin is expressed in the adrenal medulla of humans but is not detectable in the adrenal glands of many other mammalian species.
Phencyclidine-Induced Immunodepression
Authors: Khansari Nemat , Whitten H. D. , Fudenberg H. Hugh
Published: October 2006

Phencyclidine ("PCP" or "angel dust") and some of its derivatives are psychotomimetic drugs that have been used in general anesthesia for some time. This drug blocks potassium ion channels in brain tissue, and there is a specific PCP binding to lymphocytes. In a study of the effects of this drug on immunocyte function, it was found that humoral and cellular immune responses in vitro were depressed when immunocytes were treated with PCP before biological assay. This finding has implications for PCP abuse and also for the use of its derivative in general anesthesia, where it may contribute to postoperative infection.
Voltage-Dependent Sodium Channels in an Invertebrate Striated Muscle
Authors: Schwartz Lawrence M. , Stühmer Walter
Published: October 2006

Striated skeletal muscles from the planktonic arrowworm
Sagitta elegans
(phylum Chaetognatha) were voltage-clamped. The muscles displayed classical voltage-dependent sodium channels that (i) showed peak transient currents when the membrane was depolarized 90 millivolts from rest, (ii) opened rapidly with peak currents flowing within 0.4 milliseconds at 4°C, (iii) showed voltage-dependent inactivation with 50 percent inactivation at +25 millivolts from rest, and (iv) were blocked by 500 nanomolar tetrodotoxin.
[
123
I]Insulin Metabolism in Normal Rats and Humans: External Detection by a Scintillation Camera
Authors: Sodoyez J. C. , Sodoyez-Goffaux F. , Guillaume M. , Merchie G.
Published: October 2006

[
123
I]Insulin was injected intravenously into rats and the distribution and kinetics of radioactivity were analyzed by external detection with a scintillation camera connected to a computer. When injected alone, [
123
I]insulin was rapidly taken up by the liver and to a smaller extent by the kidneys. After reaching a maximum at 3 to 5 minutes after injection, liver radioactivity rapidly declined and free iodide appeared in the plasma. After previous saturation of the insulin receptor compartment, [
123
I]insulin was concentrated by the kidneys only and the rate of appearance of free iodide was markedly decreased. The results demonstrate the potential usefulness of this noninvasive technique to visualize insulin interaction with the liver and kidneys and to study the rate of insulin degradation by each organ in vivo. Preliminary experiments in man demonstrate its feasibility and low radiotoxicity.
Mutagenicity of Glutathione and Cysteine in the Ames Test
Authors: Glatt Hansruedi , Protić-Sabljić Miroslava , Oesch Franz
Published: October 2006

Postmitochondrial supernatant from rat liver and kidney homogenates transformed cysteine into a mutagen that reverted bacteria of the strain
Salmonella typhimurium
TA100 to histidine independence. Glutathione was also activated by kidney postmitochondrial supernatant but not by liver preparations. Hence, important endogenous compounds of mammals are positive in the most commonly used short-term test for carcinogenicity and mutagenicity. Glutathione is positive in the test even at concentrations found in mammalian tissues.
Hyphenated Techniques for Analysis of Complex Organic Mixtures
Authors: Wilkins Charles L.
Published: October 2006

Advances in computer technology as well as analytical instrumentation have made practical analytical systems combining various separation methods and multiple spectrometric detectors. Systems consisting of a separation device and a detector, such as gas chromatography-mass spectrometry (GC-MS), are already widely used. Newer methods employing two or more detectors in addition to a separation device are exemplified by gas chromatography-Fourier transform infrared spectroscopy-mass spectrometry (GC-FTIR-MS). A GC-FTIR-MS system has been used in different configurations for the analysis of two relatively complex mixtures of about 30 compounds. Complementary information obtained with such a multi-instrument system shows that it is a potentially powerful tool for complex mixture analysis.
Bioluminescence: Dual Mechanism in a Planktonic Tunicate Produces Brilliant Surface Display
Authors: Galt Charles P.
Published: October 2006

Luminescent flashes emanate spontaneously and on mechanical stimulation from the bodies of
Oikopleura dioica
(Urochordata, Larvacea); flashes also emanate, on mechanical stimulation only, from both their occupied and discarded mucous houses. The luminescence is intrinsic to the animals and their houses. Field observations suggest that, because of this dual method of light production, larvaceans may contribute substantially to surface coastal displays of marine bioluminescence.
In Situ Hybridization to Study the Origin and Fate of Identified Neurons
Authors: McAllister Linda B. , Scheller Richard H. , Kandel Eric R. , Axel Richard
Published: October 2006

Egg-laying behavior in
Aplysia
is mediated by a set of peptides, including egg-laying hormone (ELH), which are released by a cluster of identified neurons, the bag cells. A family of neuropeptide genes which includes the gene encoding ELH along with two additional genes encoding the A and B peptides thought to initiate the egg-laying process has been isolated and their nucleotide sequence has been determined. In situ hybridization and immunofluorescence was used to explore the origin and distribution of the neurons that express this family of genes. The ELH genes are expressed, not only in the bag cells, but in an extensive system of neurons distributed in four of the five ganglia of the central nervous system. The genes for ELH are expressed in these cells early in the animal's life cycle. As a result, it was possible to use in situ hybridization to trace the cells expressing ELH to their site of origin. The cells originate outside the central nervous system in the ectoderm of the body wall and appear to migrate to their final locations within the central nervous system by crawling along strands of connective tissue.
Growth Self-Incitement in Murine Melanoma B16: A Phenomenological Model
Authors: Bajzer Željko , Pavelić Krešimir , Vuk-Pavlović Stanimir
Published: October 2006

The growing murine melanoma B16 secretes increasing quantities of a substance or substances immunologically cross-reactive with insulin. The elevated concentrations of these substances in blood are accompanied by a decrease in blood glucose concentration and release of growth hormone, which is followed by increased tumor growth. By use of a phenomenological model based on these data, we show that B16 incites its own growth by positive feedback.
Molecular Weight Determinations of Proteins by Californium Plasma Desorption Mass Spectrometry
Authors: Sundqvist B. , Roepstorff Peter , Fohlman J. , Hedin A. , Håkansson P. , Kamensky I. , Lindberg M. , Salehpour M. , Säwe G.
Published: October 2006

The plasma desorption mass spectrometry method is used to determine the molecular weights of larger molecules than before, to determine the molecular weights of proteins and peptides in mixtures, and to monitor protein modification reactions. Proteins up to molecular weight 25,000 can now be studied with a mass spectrometric technique. Protein-peptide mixtures that could not be resolved with conventional techniques were successfully analyzed by this technique. The precision of the method is good enough to permit one to follow the different steps in the conversion of porcine insulin to human insulin.
Purification and Sequence Analysis of Bioactive Atrial Peptides (Atriopeptins)
Authors: Currie Mark G. , Geller David M. , Cole Barbara R. , Siegel Ned R. , Fok Kam F. , Adams Steven P. , Eubanks Shad R. , Galluppi Gerald R. , Needleman Philip
Published: October 2006

Mammalian cardiac atria have several biologically active peptides that exert profound effects on sodium excretion, urine volume, and smooth muscle tone. In the present study two such peptides of low molecular weight were purified and separated from each other on the basis of differences in charge, hydrophobicity, and biological profile. The first peptide, designated atriopeptin I, exhibits natriuretic and diuretic activity and selectivity relaxes intestinal smooth muscle but not vascular smooth muscle strips. The second peptide, atriopeptin II, is a potent natriuretic and diuretic that relaxes both intestinal and vascular strips. Sequence analysis of atriopeptin I indicates that it is composed of 21 amino acids, of which serine and glycine residues predominate. The amino terminal sequence of atriopeptin II up to residue 21 is the same as that of atriopeptin I, with the addition of the Phe-Arg extension at the carboxyl terminus. Both peptides appear to be derived from a common high molecular weight precursor (designated atriopeptigen); their biological selectivity and potency may be determined by the site of carboxyl terminal cleavage.
Repression of Rearranged μ Gene and Translocated c-
myc
in Mouse 3T3 Cells × Burkitt Lymphoma Cell Hybrids
Authors: Nishikura Kazuko , ar-Rushdi Abbas , Erikson Jean , DeJesus Emma , Dugan Deborah , Croce Carlo M.
Published: October 2006

The productively rearranged immunoglobulin μ chain gene and the translocated cellular oncogene c-
myc
are transcribed at high levels both in human Burkitt lymphoma cells carrying the t(8;14) chromosome translocation and in mouse plasmacytoma × Burkitt lymphoma cell hybrids. In the experiments reported here these genes were found to be repressed in mouse 3T3 fibroblast × Burkitt lymphoma cell hybrids. Such repression probably occurs at the transcriptional level since no human μ- and c-
myc
messenger RNA's are detectable in hybrid clones carrying the corresponding genes. It is therefore concluded that the ability to express these genes requires a differential B cell environment. The results suggest that the 3T3 cell assay may not be suitable to detect oncogenes directly involved in human B cell oncogenesis, since 3T3 cells apparently are incapable of transcribing an oncogene that is highly active in malignant B cells with specific chromosomal translocations.
Ellipsosomes: Organelles Containing a Cytochrome-Like Pigment in the Retinal Cones of Certain Fishes
Authors: MacNichol E. F. , Kunz Y. W. , Levine J. S. , Hárosi F. I. , Collins B. A.
Published: October 2006

Ellipsosomes are dense spherical bodies containing a very large concentration of a heme pigment spectroscopically resembling pure cytochrome c. They are located at the outer ends of the inner segments of the cones of certain fishes. Although, superficially, they resemble the similarly located oil droplets in the cones of birds and reptiles, their ultrastructure and staining properties resemble those of the neighboring mitochondria. However, like the oil droplets, they may serve as intracellular color filters.
Phosphoglucomutase: Evidence for a New Locus Expressed in Human Milk
Authors: Cantú José María , Ibarra Bertha
Published: October 2006

Electrophoretic study of phosphoglucomutase (PGM) in human milk revealed different patterns that can be explained by the existence of a locus distinct from the common PGM1, PGM2, and PGM3. One hundred and forty samples were tested and the results showed four different alleles of PGM4 whose frequencies were under Hardy-Weinberg equilibrium.