bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonenzymatic Browning in Vivo: Possible Process for Aging of Long-Lived Proteins
Authors: Monnier Vincent M. , Cerami Anthony
Published: October 2006

The incubation of lens proteins with reducing sugars leads to the formation of fluorescent yellow pigments and cross-links similar to those reported in aging and cataractous human lenses. Called nonenzymatic browning or the Maillard reaction, this aging process also occurs in stored foods. Reducing sugars condense with the free amino group of proteins, then rearrange and dehydrate to form unsaturated pigments and cross-linked products. Although most proteins in living systems turn over with sufficient rapidity to avoid nonenzymatic browning, some, such as lens crystallins and skin collagen, are exceptionally long-lived and may be vulnerable.
Transmission of Oropouche Virus from Man to Hamster by the Midge
Culicoides paraensis
Authors: Pinheiro Francisco P. , Travassos da Rosa Amelia P. A. , Gomes Maria L. C. , LeDuc James W. , Hoch Alfred L.
Published: October 2006

Oropouche virus (arbovirus family Bunyaviridae, Simbu serological group) was experimentally transmitted from man to hamster by the bite of the midge
Culicoides paraensis
. Infection rates and transmission rates were determined after the midge had engorged on patients with viremia. The threshold titer necessary to enable infection or transmission by the midges was approximately 5.3 log
10
of the median lethal dose of the virus in suckling mice per milliliter of blood. Transmission was achieved 6 to 12 days after
C. paraensis
had taken the infective blood meal. This represents conclusive evidence of transmission of an arbovirus of public health importance to man by a member of the Ceratopogonidae family.
Loco Intoxication: Indolizidine Alkaloids of Spotted Locoweed (
Astragalus lentiginosus
)
Authors: Molyneux Russell J. , James Lynn F.
Published: October 2006

The indolizidine alkaloids swainsonine and swainsonine
N
-oxide have been isolated and identified as constituents of spotted locoweed. The inhibition of lysosomal α-mannosidase by these alkaloids suggests that they are the causative agents of locoism in range animals.
Metabolism of 2,4′,5-Trichlorobiphenyl by the Mercapturic Acid Pathway
Authors: Bakke J. E. , Bergman Å. L. , Larsen G. L.
Published: October 2006

Carbon-14-labeled 2,4′,5-trichlorobiphenyl was found to be metabolized by the mercapturic acid pathway to metabolites that are excreted in bile. About 57 percent of the carbon-14 was excreted in the bile; 30 to 35 percent was present as mercapturic acid pathway metabolites. Mercapturic acid was also isolated from the urine (0.3 percent of the dose).
Leukotriene D
4
: a Potent Coronary Artery Vasoconstrictor Associated with Impaired Ventricular Contraction
Authors: Michelassi F. , Landa L. , Hill R. D. , Lowenstein E. , Watkins W. D. , Petkau A. J. , Zapol W. M.
Published: October 2006

Leukotriene D
4
(2 × 10
-9
mole), injected into the left circumflex coronary artery of anesthetized sheep, produced profound coronary vasoconstriction and impaired regional ventricular wall motion. This cardiac effect was neither inhibited by prior treatment of the sheep with a cyclooxygenase inhibitor nor associated with thromboxane B
2
release into the coronary sinus. Intravenous FPL 55712 completely abolished the coronary vasoconstriction of leukotriene D
4
, but a significant reduction of regional wall shortening persisted.
Growth Hormone-Releasing Factor from a Human Pancreatic Tumor That Caused Acromegaly
Authors: Guillemin Roger , Brazeau Paul , Bohlen Peter , Esch Frederick , Ling Nicholas , Wehrenberg William B.
Published: October 2006

A 44 amino acid peptide with growth hormone-releasing activity has been isolated from a human tumor of the pancreas that had caused acromegaly. The primary structure of the tumor-derived peptide is H-Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-Gln-Gln-Gly-Glu-Ser-Asn-Gln-Glu-Arg-Gly-Ala-Arg-Ala-Arg-Leu-NH
2
. The synthetic replicate has full biological activity in vitro and in vivo specifically to stimulate the secretion of immunoreactive growth hormone. The tumor-derived peptide is identical in biological activity and similar in physicochemical properties to the still uncharacterized growth hormone-releasing factor present in extracts of hypothalamic tissues.
Methoxyindoles and Photoreceptor Metabolism: Activation of Rod Shedding
Authors: Besharse Joseph C. , Dunis Daiga A.
Published: October 2006

Using an in vitro eye-cup preparation, we have evaluated a potential relationship between methoxyindole metabolism and photoreceptor disk shedding. Melatonin, 6-chloromelatonin, and 5-methoxytryptophol all activate rod disk shedding in culture. The effect is compound specific since serotonin and
N
-acetylserotonin are without effect, and it is similar to shedding in vivo because it is evoked by light and is quantitatively comparable to a normal intact animal response. The results suggest the involvement of 5-methoxyindoles in the control of rhythmic photoreceptor metabolism.
Slow Compressional Wave Propagation in Wet Human and Bovine Cortical Bone
Authors: Lakes Roderic , Yoon Hyo Sub , Katz J. Lawrence
Published: October 2006

Ultrasonic wave propagation in bovine plexiform and human Haversian bone was studied in the range 0.5 to 15 megahertz. A new longitudinal wave was observed which traveled more slowly than the ordinary longitudinal wave. The slow wave was associated with the dynamics of fluid motion in the pores of bone.
Path-Guided Apparent Motion
Authors: Shepard Roger N. , Zare Susan L.
Published: October 2006

A curved gray path, briefly flashed between two alternately displayed black dots, induced a compelling illusion of a single dot moving back and forth over that path. The minimum interval between dot onsets yielding this apparent motion increased not with the direct distance between the dots but, linearly, with the length of the curved path.
Allergic Orchitis Lesions Are Adoptively Transferred from Vasoligated Guinea Pigs to Syngeneic Recipients
Authors: Tung Kenneth S. K.
Published: October 2006

Histopathology typical of allergic orchitis developed in testes of inbred guinea pigs 16 months after vasoligation. A similar histopathology was found in unoperated testes after unilateral vasoligation. Peritoneal exudate cells from vasoligated guinea pigs transferred identical lesions to syngeneic recipients. The testicular lesions in long-term vasoligated guinea pigs have an immunologic basis.
Ultraviolet Radiation—Induced Chromosomal Abnormalities in Fetal Fibroblasts from New Zealand Black Mice
Authors: Reddy A. Lakshma , Fialkow Philip J. , Salo Armi
Published: October 2006

Fibroblasts from New Zealand Black mouse fetuses manifest increased frequency of chromosomal breaks and interchanges after exposure to ultraviolet radiation when compared with cells from BALB/c fetuses. This chromosomal instability is similar to what has been reported in cells from patients with xeroderma pigmentosum and may be related to the chromosomally abnormal clones and malignancy previously reported in adult New Zealand Black mice.
Selective Depression of Serum Growth Hormone During Maternal Deprivation in Rat Pups
Authors: Kuhn C. M. , Butler  , Schanberg S. M.
Published: October 2006

Maternal deprivation was associated with a decline in immunoreactive growth hormone in the serum of rat pups. Pups that were returned to the mother showed a rapid reversal in this deprivation-induced decrease. The change in growth hormone concentration was not accompanied by changes in the concentrations of prolactin, thyrotropin, or corticosterone in the serum, but were correlated with alteration in the activity of ornithine decarboxylase in the brain. Treatment of neonatal rat pups with cyproheptadine, a serotonin antagonist that suppresses growth hormone secretion, resulted in a significant decline in both serum growth hormone concentration and brain ornithine decarboxylase activity. These findings suggest that maternal deprivation elicits a specific suppression of growth hormone release which mediates the decrease in ornithine decarboxylase activity. The study is consistent with clinical findings of impaired growth hormone "responsivity" in human maternal deprivation syndrome.
Human Endometrial Adenocarcinoma Transplanted into Nude Mice: Growth Regulation by Estradiol
Authors: Satyaswaroop P. G. , Zaino R. J. , Mortel R.
Published: October 2006

A model for studying the growth of primary tumors of human endometrium and its regulation by 17β-estradiol has been developed in which ovariectomized nude mice are used as recipients. The receptors for sex steroids are maintained during serial transplantation of the tumor in this system. Although the rate of growth of receptor-negative endometrial tumors transplanted into ovariectomized nude mice is unaffected by the sustained presence or absence of estradiol, the growth of receptor-positive tumors is significantly increased by estradiol. Receptor-positive tumors treated with estradiol produced elevated concentrations of progesterone receptor. That the progesterone receptor is functional in this tumor is evident from the induction of estradiol 17β-dehydrogenase activity upon progestin administration. These findings are consistent with receptor-mediated regulation of growth of endometrial carcinoma.
Guanosine Triphosphate Activation of Brain Adenylate Cyclase: Enhancement by Long-Term Antidepressant Treatment
Authors: Menkes David B. , Rasenick Mark M. , Wheeler Marcia A. , Bitensky Mark W.
Published: October 2006

Activation of adenylate cyclase by a stable guanosine 5′-triphosphate analog was augmented in brain membrane preparations from rats treated on a long-term basis with tricyclic antidepressants or electroconvulsive shock. These treatments may facilitate cyclase activation by promoting the interaction of the regulatory and catalytic subunits of the enzyme. This finding suggests a possible mechanism for the changes in sensitivity to various neurotransmitters seen after antidepressant administration.
Relation Between Plasma and Cerebrospinal Fluid Levels of 3-Methoxy-4-Hydroxyphenylglycol
Authors: Kopin Irwin J. , Gordon E. K. , Jimerson D. C. , Polinsky R. J.
Published: October 2006

Concentrations of free 3-methoxy-4-hydroxyphenylglycol in the plasma and cerebrospinal fluid are highly correlated, but concentrations in the cerebrospinal fluid are always higher than those in plasma, even when large amounts of the catecholamine metabolite are derived from a tumor of the adrenal medulla. This is explained by considering the plasma and cerebrospinal fluid as a two-compartment system in which the rate constants for entry into and exit from the cerebrospinal fluid compartment are similar. 3-Methoxy-4-hydroxyphenylglycol that is synthesized, but not catabolized, in the central nervous system maintains cerebrospinal fluid levels at an increment over those in plasma. This increment can be used to provide the best available index of formation of 3-methoxy-4-hydroxyphenylglycol in the central nervous system.
Mutations Affecting Programmed Cell Deaths in the Nematode
Caenorhabditis elegans
s
Authors: Hedgecock Edward M. , Sulston John E. , Thomson J. Nichol
Published: October 2006

Mutations in two nonessential genes specifically block the phagocytosis of cells programmed to die during development. With few exceptions, these cells still die, suggesting that, in nematodes, engulfment is not necessary for most programmed deaths. Instead, these deaths appear to occur by cell suicide.
Nuclear Transplantation in the Mouse Embryo by Microsurgery and Cell Fusion
Authors: McGrath James , Solter Davor
Published: October 2006

Nuclear transplantation in the mouse embryo was achieved by using a method that combines microsurgical removal of the zygote pronuclei with the introduction of a donor nucleus by a virus-mediated cell fusion technique. Survival of embryos was greater than 90 percent in tests of this procedure. The embryos developed to term at a frequency not significantly different from that of nonmanipulated control embryos. Because nuclei and cytoplasm from genetically distinct inbred mouse strains can be efficiently interchanged, this procedure may be useful in characterizing possible cytoplasmic contributions to the embryonic and adult phenotype.
Indoor Air Pollution: A Public Health Perspective
Authors: Spengler John D. , Sexton Ken
Published: October 2006

Although official efforts to control air pollution have traditionally focused on outdoor air, it is now apparent that elevated contaminant concentrations are common inside some private and public buildings. Concerns about potential public health problems due to indoor air pollution are based on evidence that urban residents typically spend more than 90 percent of their time indoors, concentrations of some contaminants are higher indoors than outdoors, and for some pollutants personal exposures are not characterized adequately by outdoor measurements. Among the more important indoor contaminants associated with health or irritation effects are passive tobacco smoke, radon decay products, carbon monoxide, nitrogen dioxide, formaldehyde, asbestos fibers, microorganisms, and aeroallergens. Efforts to assess health risks associated with indoor air pollution are limited by insufficient information about the number of people exposed, the pattern and severity of exposures, and the health consequences of exposures. An overall strategy should be developed to investigate indoor exposures, health effects, control options, and public policy alternatives.
Salicylate and Mitochondrial Injury in Reye's Syndrome
Authors: You Kwan-SA
Published: October 2006

Electron microscopic and spectrophotometric studies showed that salicylate causes gross swelling of mitochondria in isotonic salt solutions. In overall morphology the salicylate-treated mitochondria resembled those from patients with Reye's syndrome. Salicylate analogs such as
m
-hydroxybenzoate,
p
-hydroxybenzoate, and benzoate did not exert this effect. The mitochondria deformed by salicylate tended to return to their original condensed form on removal of the drug.
Combined Lipase Deficiency (
cld
): a Lethal Mutation on Chromosome 17 of the Mouse
Authors: Paterniti James R. , Brown W. Virgil , Ginsberg Henry N. , Artzt Karen
Published: October 2006

Two triglyceride lipases, lipoprotein lipase and hepatic triglyceride lipase, participate in the metabolism of plasma lipoproteins. A single recessive mutation,
cld
, on mouse chromosome 17 causes an apparent deficiency of both lipoprotein lipase and hepatic triglyceride lipase activities. Mice homozygous for this defect develop lethal hyperchylomicronemia within 2 days postpartum as a consequence of nursing. Plasma triglyceride values in affected mice often reach 20,000 milligrams per deciliter (100 times higher than that in normal littermates), and total lipase activity in plasma or tissues is 5 to 20 percent of that in controls.
Spectral Consequences of Photoreceptor Sampling in the Rhesus Retina
Authors: Yellott John I.
Published: October 2006

Optical transforms were used to compute the power spectra of rhesus cones treated as arrays of image sampling points. Spectra were obtained for the central fovea, parafovea, periphery, and far periphery. All were consistent with a novel spatial sampling principle that introduces minimal noise for spatial frequencies below the Nyquist limits implied by local receptor densities, while frequencies above the nominal Nyquist limits are not converted into conspicuous moire patterns, but instead are scattered into broadband noise. This sampling scheme allows the visual system to escape aliasing distortion despite a large mismatch between retinal image bandwidth and the Nyquist limits implied by extrafoveal cone densities.
A Silent, Neutral Substitution Detected by Reverse-Phase High-Performance Liquid Chromatography: Hemoglobin Beirut
Authors: Strahler John R. , Rosenbloom Barnett B. , Hanash Samir M.
Published: October 2006

A substitution of alanine for valine at position 126 in the β-chain of hemoglobin was discovered in a hematologically normal adult male of Lebanese extraction. The variant β-globin was initially observed and subsequently purified by reverse-phase high-performance liquid chromatography (HPLC). Reverse-phase HPLC was also used to isolate the variant tryptic peptide of β-T13 that has alanine replacing valine at residue 126. The discovery of hemoglobin Beirut illustrates the usefulness of reverse-phase HPLC for the detection of neutral amino acid substitutions in proteins. The ability to detect neutral substitutions in undigested proteins is pertinent to the monitoring of genetic variation in human populations.
New Chemistry of an Old Molecule:
cis
-[Pt(NH
3
)
2
Cl
2
]
Authors: Lippard Stephen J.
Published: October 2006

The discovery that
cis
-diamminedichloroplatinum(II) (
cis
-DDP) has clinically useful antitumor properties and can form platinum blues spawned an extensive investigation of its chemistry in water. Several new molecules have been synthesized, some rather old ones have been characterized for the first time, and clues have begun to emerge about the chemical interaction of
cis
-DDP with its likely biological target, DNA.
A Method for Purification of Extracts Containing the Growth-Promoting Principle of the Anterior Hypophysis
Authors: Teel Harold M.
Published: October 2006

(1) The growth-promoting principle of the anterior hypophysis may be salted out of the more crude extracts by means of sodium sulphate.

(2) Attempts to further fractionate the globulin group of proteins in which the growth-promoting principle comes down resulted in a division of the substances between the fractions.
Apparent Saturation of Blue-Sensitive Cones Occurs at a Color-Opponent Stage
Authors: Stromeyer C. F. , Kronauer R. E. , Madsen J. C.
Published: October 2006

Response saturation of blue-sensitive cone pathways was studied by measuring increment thresholds for violet test flashes on flashed violet fields in the presence of a steady yellow "auxiliary" field of constant radiance. Adding intense yellow field flashes to the violet field flash could eliminate or reduce response saturation (greatly reduce threshold), whereas "negative" yellow field flashes drove the mechanism to further saturation. The response saturation is thus not, in general, controlled exclusively by independent blue-sensitive cones but by spectrally opponent mechanisms that receive opposite-signed signals from blue-sensitive cones and from green- or red-sensitive cones. These results add to a growing number of studies that demonstrate that detection of signals from blue-sensitive cones is largely through a color-opponent pathway.
Mutagenic Activity in Photocopies
Authors: Löfroth Göran , Hefner Edward , Alfheim Ingrid , Møller Mona
Published: October 2006

Extracts from several different photocopies were mutagenic in the Ames
Salmonella
assay. The mutagenic behavior was similar for extracts from copies and corresponding toners indicating that toners are directly responsible for the mutagenicity. The mutagenicity is caused by at least two classes of compounds which may be present either alone or in combination in any toner.
Salary Scales of Trained Men and Women
Authors: True Rodney H.
Published: October 2006

A comparison of salary scales of trained men shows rather clearly at the present time that

(1) The pay scale of endowed and state universities and agricultural colleges is approximately like that of the commissioned officers of the army and the navy, but lacks the advantage of the retiring pension of three fourths pay. This pension often relieves the military and naval officer of the necessity of saving for old age. The saving required of the academic man to give him an equivalent retiring fund is not practicable at the present salary scale.

(2) It shows that the academic salary scale is appreciably lower than that of the professional and scientific services of the national government at Washington. The retiring allowance of the government employee, though small, and in part contributed by the employee himself, gives him a distinct advantage.

(3) The salaries of all groups above mentioned are very much lower than those paid in manufacturing enterprises to positions above the wage-earners.

In order to make a concrete comparison, I will enumerate the positions that on the average command salaries of $3,000, $6,000 and $9,000 respectively in these different lines of work.
Lectins of Distinct Specificity in
Rhodnius prolixus
Interact Selectively with
Trypanosoma cruzi
Authors: Pereira Miercio E. , Andrade Arnaldo F. B. , Ribeiro Jose Marcos C.
Published: October 2006

Lectins of different activities were found in the crop, midgut, and hemolymph of the insect
Rhodnius prolixus
. These were most specific for
N
-acetyl-D-mannosamine, α-
N
-acetyl-D-galactosamine, and α- and β-galactose, respectively. Lectin receptors were detectable in epimastigote but not in trypomastigote forms of
Trypanosoma cruzi
, a protozoan parasite of the insect and of humans.
Contractility of Bile Canaliculi: Implications for Liver Function
Authors: Oshio C. , Phillips M. J.
Published: October 2006

Dynamic contractions of bile canaliculi were observed in groups of cultured hepatocytes by time-lapse cinephotomicrography during the early stages of monolayer formation. The contractions, which were forceful and appeared to have a pumping action, may facilitate the flow of bile in the liver's canalicular system.
Selective Protection of Methionine Enkephalin Released from Brain Slices by Enkephalinase Inhibition
Authors: Patey Gilles , De La Baume Sophie , Schwartz Jean-Charles , Gros Claude , Roques Bernard , Fournie-Zaluski Marie-Claude , Soroca-Lucas Evelyne
Published: October 2006

Methionine enkephalin release was evoked by depolarization of slices from rat striatum with potassium. In the presence of 0.1 μM thiorphan [(N(R,S)-3-mercapto-2-benzylpropionyl)glycine], a potent inhibitor of enkephalin dipeptidyl carboxypeptidase (enkephalinase), the recovery of the pentapeptide in the incubation medium was increased by about 100 percent. A similar effect was observed with the dipeptide phenylalanylalanine, a selective although less potent enkephalinase inhibitor. Inhibition of other known enkephalin-hydrolyzing enzymes—aminopeptidase by 0.1 m
M
puromycin or angiotensin-converting enzyme by 1 μM captopril—did not significantly enhance the recovery of released methionine enkephalin. These data indicate that enkephalinase is critically involved in the inactivation of the endogenous opioid peptide released from striatal neurons.
Detection of Mutagens in Complex Samples by the
Salmonella
Assay Applied Directly on Thin-Layer Chromatography Plates
Authors: Bjørseth A. , Eidså G. , Gether J. , Landmark L. , Møller M.
Published: October 2006

A new technique is reported in which components in complex samples are separated on thin-layer chromatography plates and their mutagenic effect is registered directly on the plates by means of the Salmonella assay. The method is quick and simple and particularly useful for screening large numbers of environmental samples. Qualitative comparisons of mutagens in different samples can easily be made. Registered mutagens can be identified by the chemical analysis of extracts from duplicate plates.
Induction of Crisis Forms in Cultured
Plasmodium falciparum
with Human Immune Serum from Sudan
Authors: Jensen James B. , Boland Michael T. , Akood Mustafa
Published: October 2006

Serums from 90 individuals from three areas in Sudan were tested for inhibitory activity against cultures of
Plasmodium falciparum
. In addition to inhibitory activity against merozoite invasion, all of the serums demonstrated, in varying degrees, the ability to retard intraerythrocytic development, leading to crisis forms and parasite deterioration. These retardation factors could be removed by absorption of immune serum with parasite-infected erythrocytes and were demonstrable in purified immunoglobulin fractions. Serum from donors in hypoendemic Khartoum did not retard parasite development.
Anomalous Patterns in Cultured Cell Monolayers
Authors: Adler E. M. , Flunk L. J. , Mullin J. M. , Kleinzeller A.
Published: October 2006

Gridlike patterns of differing cell density were observed in evenly seeded cell monolayers. Such patterns were obtained in five of six cell lines tested, suggesting widespread occurrence. The mechanism appears to involve small, transient temperature changes related to incubator tray structure. The very short time course of appearance of the patterns implicates attachment rather than growth as the critically affected factor. Impaired adhesion or directed sedimentation resulting from thermally induced microcurrents in the medium are the two most likely mechanisms.
Myocardial Injury: Quantitation by Cell Sorting Initiated with Antimyosin Fluorescent Spheres
Authors: Khaw B. A. , Scott J. , Fallon J. T. , Cahill S. L. , Haber E. , Homcy C.
Published: October 2006

Spheres coated with antibodies specific for myosin were used to detect myocardial cell membrane disruption by scanning electron microscopy. Injury in a population of cultured myocytes was then followed and measured by fluorescence-activated cell sorting. This approach provides a unique method for quantitating the evolution of myocardial injury and potentially for assessing the efficacy of interventions aimed at myocardial protection.
Recovery of Olfactory Function After Bilateral Bulbectomy
Authors: Wright John W. , Harding Joseph W.
Published: October 2006

Mice were trained to discriminate between scented and unscented air. After olfactory bulbs were removed, discrimination was lost, but returned with the formation of synaptic connections between regenerated primary olfactory neurons and the cortex of the forebrain. The acquisition of a second olfactory-mediated task by long-term bulbectomized mice and controls was indistinguishable. The results emphasize the plasticity of the nervous system, correlate the presence of neural connections between olfactory mucosa and forebrain with the recovery of olfactory function, suggest that olfactory-mediated memory resides at least in part outside the olfactory bulbs, and demonstrate that the bulbs are not required for the acquisition of olfactory tasks.
Proliferative Capacity of Murine Hematopoietic Stem Cells in Vitro
Authors: Reincke Ursula , Hannon Eileen C. , Rosenblatt Margery , Hellman Samuel
Published: October 2006

Large numbers of granulocytes can be collected repeatedly from the supernatant medium of long-term cultures of mouse bone marrow cells. A constant relationship was found between the number of adherent hematopoietic stem cells and the lifetime cell production per culture. The data indicate that there is a limit to the proliferative capacity of normal and of irradiated stem cells. A similar limitation was found in the production of marked granulocytes from clonal cultures of "beige" C57 (
bg/bg
J
) stem cells placed in limiting dilutions into stromal culture layers.
Entorhinal Cortex Lesions Induce a Decreased Calcium Transport in Hippocampal Mitochondria
Authors: Baudry Michel , Fuchs Jannon , Kessler Markus , Arst Denise , Lynch Gary
Published: October 2006

Lesions to the entorhinal afferent of the hippocampus in rats caused marked changes in calcium transport into mitochondria. Pyruvate-supported calcium transport into mitochondria from the denervated hippocampus was decreased to a larger extent than succinate-supported transport, and adenosine triphosphate-supported transport was not significantly modified. Although cytochrome oxidase and succinate dehydrogenase activities were not significantly changed by entorhinal lesions, pyruvate flux through pyruvate dehydrogenase was significantly decreased, and this effect was correlated with changes in pyruvate-supported calcium transport. The active portion of pyruvate dehydrogenase decreased, whereas total pyruvate dehydrogenase was not modified. These data suggest that denervation might initiate dendritic atrophy and subsequent growth responses by modifying calcium regulation through a change in the phosphorylation of pyruvate dehydrogenase.
Inability of Oxytocin to Activate Pyruvate Dehydrogenase in the Brattleboro Rat
Authors: Hanif Khawar , Lederis Karl , Hollenberg Morley D. , Goren H. Joseph
Published: October 2006

Oxytocin has insulin-like activity in that it stimulates lipogenesis and increases pyruvate dehydrogenase activity. However, in adipocytes from homozygous Brattleboro rats oxytocin is incapable of stimulating lipogenesis or pyruvate dehydrogenase activity, although insulin stimulation of both processes is normal and the antilipolytic activity of oxytocin is normal. Thus, the Brattleboro rat provides a new genetic model for the study of oxytocin action, wherein recognition of the chemical mediator is partially defective.
Single-Neuron Labeling in the Cat Auditory Nerve
Authors: Liberman M. C.
Published: October 2006

Single auditory nerve fibers in the cat were labeled intracellularly with horseradish peroxidase. The sample of fibers was selected to represent different response types over a wide range of characteristic frequencies. All 56 labeled neurons were found to be radial fibers innervating inner hair cells, suggesting that none of the single-unit data reported to date has been from the outer hair cell innervation. Differences in rates of spontaneous discharge and thresholds to tones among these labeled neurons were closely correlated with morphological differences in the caliber and location of their unmyelinated terminals on the body of the inner hair cell.
Temporal Trends in the Lead Concentrations of Umbilical Cord Blood
Authors: Rabinowitz Michael B. , Needleman Herbert L.
Published: October 2006

Umbilical cord blood specimens from 11,837 births between April 1979 and April 1981 have been analyzed for lead by anodic stripping voltammetry. The mean was 6.56 ± 3.19 (standard deviation) micrograms per deciliter of blood, and the range was 0.0 to 37.0 micrograms per deciliter. The mean decreased annually by 0.77 ± 0.03 microgram per deciliter, about 11 percent. Lead concentrations were higher in infants born in summer than in infants born in winter (7.17 versus 5.99, probability < .001). A Fourier model of the data is presented, and possible reasons for the decline are discussed.
Hair-Cell Innervation by Spiral Ganglion Cells in Adult Cats
Authors: Kiang N. Y. S. , Rho J. M. , Northrop C. C. , Liberman M. C. , Ryugo D. K.
Published: October 2006

A horseradish peroxidase technique was used to trace the peripheral terminations of two types of ganglion cells in adult cats. It was found that large, usually bipolar ganglion cells end on inner hair cells and small, usually pseudomonopolar ganglion cells end on outer hair cells. Thus, a virtually complete segregation of afferent neural inputs from the two types of hair cells was directly confirmed.
Hatching of Amphibian Embryos: The Physiological Trigger
Authors: Petranka James W. , Just John J. , Crawford Eugene C.
Published: October 2006

Marbled salamander embryos hatch in water if the environmental oxygen pressure is 86 torr or less, but do not hatch if the environmental oxygen pressure is equivalent to that of air. Under hypoxic conditions, embryos hatch in aqueous and nonaqueous media with equal success. Increasing carbon dioxide pressure does not induce hatching, but does decrease the time to hatching by altering environmental
p
H.
Anatomical Plasticity and Sparing of Function After Spinal Cord Damage in Neonatal Cats
Authors: Bregman Barbara S. , Goldberger Michael E.
Published: October 2006

Spinal cord damage in neonatal cats has different effects on different spinal pathways. Corticospinal projections exhibit anatomical plasticity, forming an aberrant pathway that bypasses the lesion. In contrast, brainstem-spinal pathways undergo massive retrograde degeneration. Neither of these responses occurs in adult cats. Sparing of motor function is found in cats operated on as neonates but not in cats operated on as adults, and appears to depend on the plasticity of the corticospinal tract.
Mice Regrow the Tips of Their Foretoes
Authors: Borgens Richard B.
Published: October 2006

Mice will replace the tip of a foretoe when it is amputated distal to the last interphalangeal joint. Amputation of the digit more proximal to the joint does not result in regrowth of the foretoe. Though this growth shares certain similarities with the epimorphic regeneration of amphibian limbs, the two processes are not the same. The regrowth reported here in mice is probably similar to the scattered clinical reports of fingertip regeneration in children, and presents a model system with which to explore the controls of wound healing and tissue reconstruction in mammals.
Living with Water Stress: Evolution of Osmolyte Systems
Authors: Yancey Paul H. , Clark Mary E. , Hand Steven C. , Bowlus R. David , Somero George N.
Published: October 2006

Striking convergent evolution is found in the properties of the organic osmotic solute (osmolyte) systems observed in bacteria, plants, and animals. Polyhydric alcohols, free amino acids and their derivatives, and combinations of urea and methylamines are the three types of osmolyte systems found in all water-stressed organisms except the halobacteria. The selective advantages of the organic osmolyte systems are, first, a compatibility with macromolecular structure and function at high or variable (or both) osmolyte concentrations, and, second, greatly reduced needs for modifying proteins to function in concentrated intracellular solutions. Osmolyte compatibility is proposed to result from the absence of osmolyte interactions with substrates and cofactors, and the nonperturbing or favorable effects of osmolytes on macromolecular-solvent interactions.
Theory and Observation in Cultural Transmission
Authors: Cavalli-Sforza L. L. , Feldman M. W. , Chen K. H. , Dornbusch S. M.
Published: October 2006

Cultural phenomena may show considerable stability over time and space. Transmission mechanisms responsible for their maintenance are worthy of theoretical and empirical inquiry; they are complex and each possible pathway has different effects on evolutionary stability of traits, as can be shown theoretically. A survey designed to evaluate the importance of some components of cultural transmission on a variety of traits showed that religion and politics are mostly determined in the family, a mode of transmission which guarantees high evolutionary stability and maintenance of high variation between and within groups.
Reversal of Morphine Disruption of Maternal Behavior by Concurrent Treatment with the Opiate Antagonist Naloxone
Authors: Bridges Robert S. , Grimm Cordelia T.
Published: October 2006

Rats whose pregnancies were surgically terminated on day 17 of gestation were injected with morphine, morphine plus naloxone hydrochloride, or saline, and then tested for maternal responsiveness toward foster young. Morphine treatment alone significantly disrupted the rate of onset and quality of maternal responsiveness. Concurrent administration of naloxone to morphine-injected rats reinstated the rapid onset of behavioral responsiveness toward foster young, such that the responsiveness of the rats treated with both morphine and naloxone was indistinguishable from that shown by saline-injected controls. The disruptive effects of morphine did not appear to result from a general reduction in activity levels as measured in an open-field apparatus. These findings suggest that the normal onset and maintenance of maternal behavior in the rat may be regulated by endogenous opiates.
Focal Cortical Seizures Cause Distant Thalamic Lesions
Authors: Collins Robert C. , Olney John W.
Published: October 2006

Topical application of convulsants to the rat sensorimotor cortex in concentrations sufficient to cause repetitive focal motor seizures resulted in acute neuropathology (dark cell neuronal degeneration and spongiform neuropil changes) involving both the cortical seizure focus and certain thalamic nuclei within seizure pathways. Changes in the cortex were localized primarily in layer IV and those in the thalamus in nuclei having reciprocal connections with the cortical focus. The spongiform neuropil changes consisted of massively dilated presynaptic axon terminals in the cortex and postsynaptic dendrites in the thalamus. The dendritic and dark cell changes resemble the excitotoxic damage caused by glutamate and aspartate. Since these putative transmitters may be released locally from recurrent collaterals and remotely from corticothalamic axons, excessive release of glutamate or aspartate may account for the changes in both sites. The abnormal axons in sensory cortex appear to be terminals of thalamocortical neurons. Swelling of these axons may be caused by excessive anti- and orthodromic firing in the course of focal motor seizures.
Nonimmunological Production pf Leukotrienes Induced by Platelet-Activating Factor
Authors: Voelkel N. F. , Worthen S. , Reeves J. T. , Henson P. M. , Murphy R. C.
Published: October 2006

Platelet-activating factor caused rapid pulmonary vasoconstriction and edema in isolated lungs perfused with albumin-free salt solution devoid of formed blood elements. These effects may be due in part to the action of leukotrienes D
4
and C
4
, which were identified by bioassay and high-pressure liquid chromatography in the lung effluent after stimulation by platelet-activating factor. These findings help illuminate some of the deleterious effects that platelet-activating factor elicits in anaphylactic reactions and possibly in other forms of lung injury.
Heritable True Fitness and Bright Birds: A Role for Parasites?
Authors: Hamilton William D. , Zuk Marlene
Published: October 2006

Combination of seven surveys of blood parasites in North American passerines reveals weak, highly significant association over species between incidence of chronic blood infections (five genera of protozoa and one nematode) and striking display (three characters: male "brightness," female "brightness," and male song). This result conforms to a model of sexual selection in which (i) coadaptational cycles of host and parasites generate consistently positive offspring-on-parent regression of fitness, and (ii) animals choose mates for genetic disease resistance by scrutiny of characters whose full expression is dependent on health and vigor.
Mapping the Primate Visual System with [2-
14
C]Deoxyglucose
Authors: Macko Kathleen A. , Jarvis Charlene D. , Kennedy Charles , Miyaoka Mikoto , Shinohara Mami , Sololoff Louis , Mishkin Mortimer
Published: October 2006

The [2-
14
C]deoxyglucose method was used to identify the cerebral areas related to vision in the rhesus monkey (
Macaca mulatta
). This was achieved by comparing glucose utilization in a visually stimulated with that in a visually deafferented hemisphere. The cortical areas related to vision included the entire expanse of striate, prestriate, and inferior temporal cortex as far forward as the temporal pole, the posterior part of the inferior parietal lobule, and the prearcuate and inferior prefrontal cortex. Subcortically, in addition to the dorsal lateral geniculate nucleus and superficial layers of the superior colliculus, the structures related to vision included large parts of the pulvinar, caudate, putamen, claustrum, and amygdala. These results, which are consonant with a model of visual function that postulates an occipito-temporo-prefrontal pathway for object vision and an occipito-parieto-prefrontal pathway for spatial vision, reveal the full extent of those pathways and identify their points of contact with limbic, striatal, and diencephalic structures.
Gene Dosage Compensation and the Evolution of Sex Chromosomes
Authors: Lucchesi John C.
Published: October 2006

Dosage compensation is a mechanism by means of which the activity of X-linked or Z-linked genes is made equal in the two sexes of organisms with an XX compared to XY or ZZ compared to ZW basis of sex determination. In mammals, compensation is achieved by the inactivation of one X chromosome in somatic cells of females. In Drosophila, compensation does not involve inactivation. The two X chromosomes in females as well as the single X in males are regulated, and individual genes are thought to respond independently to the regulatory mechanism. It is proposed that in both groups of organisms the evolution of heteromorphic sex chromosomes was gradual and occurred as the direct result of the evolution of dosage compensation rather than the reverse.
Growth of Infective Forms of
Trypanosoma rhodesiense
in Vitro, the Causative Agent of African Trypanosomiasis
Authors: Hill George C. , Shimer Susan Peterlin , Caughey Byron , Sauer L. Scott
Published: October 2006

A new approach to the culture of African trypanosomes led to the growth of the infective forms of the causative agent of human African trypanosomiasis. Infective cultures of
Trypanosoma rhodesiense
were initiated and maintained in vitro on Chinese hamster lung cells. By changing daily one-third of the Hepes-buffered RPMI 1640 medium containing 20 percent fetal bovine serum, the trypanosome numbers increased to 3 × 10
6
to 5 × 10
6
cells per milliliter. After 80 days in vitro at 37°C, the cultured trypomastigotes are infective for mice and rats and morphologically similar to bloodstream trypomastigotes in having a subterminal kinetoplast and a surface coat. In addition, they possess L-α-glycerophosphate oxidase, the predominant steady-state terminal oxidase of bloodstream trypomastigotes.
Memory Impairment in Epileptic Patients: Selective Effects of Phenobarbital Concentration
Authors: MacLeod Colin M. , Dekabian Anatole S. , Hunt Earl
Published: October 2006

Nineteen epileptic patients were tested first under medium (week 1) and then under high (week 2) therapeutic levels of phenobarbital. Relative to response times of 20 controls with equivalent practice but without medication, response times of patients in a short-term memory scanning task were strikingly slowed during week 2. However, increased phenobarbital did not slow responses in a task requiring access to information in long-term memory.
αA-Crystallin Messenger RNA of the Mouse Lens: More Noncoding Than Coding Sequences
Authors: King Charles R , Shinohara Toshimichi , Piatigorsky Joram
Published: October 2006

The 14
S
messenger RNA (1300 to 1500 nucleotides) for the αA chain of α-crystallin of the mammalian lens is nearly three times larger than required to code for the polypeptide that contains 173 amino acids. As a means of accounting for this anomaly, a complementary DNA clone for the mouse αA-crystallin messenger RNA was constructed in pBR322 and sequenced. Derivation of the protein sequence from the nucleic acid sequence showed that mouse αA-crystallin is similar to that of other organisms. The messenger RNA contains 536 nucleotides located on the 3′ side of the coding region, excluding the polyadenylate stretch. This 3′ sequence does not encode any other crystallin and has multiple termination codons in the three possible reading frames.
Increased Dopamine Receptor Sensitivity After Estrogen Treatment Using the Rat Rotation Model
Authors: Hruska Robert E. , Silbergeld Ellen K.
Published: October 2006

Estrogen was administered to male rats that had received unilateral injections of 6-hydroxydopamine into the striatum. Following this treatment, their duration of rotation increased in response to amphetamine. Estrogen treatment resulted in a corresponding increase in the number of striatal dopamine receptors. Therefore, both behavioral and biochemical evidence suggests that striatal dopamine function is influenced by peripherally administered estrogens. These results are relevant to the clinical cases of chorea associated with elevated concentrations of estrogen, which occur in pregnancy and during oral contraceptive use.
Lateral Diffusion of Surface Molecules in Animal Cells and Tissues
Authors: Gall W. Einar , Edelman Gerald M.
Published: October 2006

When bound to cell surfaces, certain lectins such as concanavalin A induce a drop in the average diffusion coefficients (
D
) of a number of cell surface molecules. To find whether such anchorage modulation occurs naturally,
D
of surface antigens on different cell and tissue types were measured by fluorescence photobleaching recovery. Values for cells of the same tissue origin under different conditions of growth and association—in tissues, in small aggregates, and as isolated cells—varied by less than twofold when polyspecific monovalent antibodies to cell surface antigens were used, a range much less than the sixfold decrease in
D
observed after lectin-induced anchorage modulation. Thus, if reversible modulation of the diffusion rate is used naturally as a means of cell signaling, it must involve only a few kinds of surface receptors not detected by the antibodies used in this study. In certain tissues, however, a significant proportion of cells showed no apparent receptor mobility. This "all or none" modulation of lateral diffusion may reflect relatively long-lasting alterations in the states of a single cell type or differentiation among the cells of the particular tissue.
Vitellogenesis and the Vitellogenin Gene Family
Authors: Wahli Walter , Dawid Igor B. , Ryffel Gerhart U. , Weber Rudolf
Published: October 2006

Vitellogenin is synthesized under estrogen control in the liver, extensively modified, transported to the ovary, and there processed to the yolk proteins lipovitellin and phosvitin. In the frog
Xenopus laevis
there are at least four distinct but related vitellogenin genes. The two genes A1 and A2 have a 95 percent sequence homology in their messenger RNA coding regions, and contain 33 introns that interrupt the coding region (exons) at homologous positions. Sequences and lengths of analogous introns differ, and many introns contain repetitive DNA elements. The introns in these two genes that have apparently arisen by duplication have diverged extensively by events that include deletions, insertions, and probably duplications. Rapid evolutionary change involving rearrangements and the presence of repeated DNA suggests that the bulk of the sequences within introns may not have any specific function.
Astatine-211—Tellurium Radiocolloid Cures Experimental Malignant Ascites
Authors: Bloomer William D. , McLaughlin William H. , Neirinckx Rudi D. , Adelstein S. James , Gordon Phillip R. , Ruth Thomas J. , Wolf Alfred P.
Published: October 2006

An investigation of the efficacy of astatine-211—tellurium colloid for the treatment of experimental malignant ascites in mice reveals that this α-emitting radiocolloid can be curative without causing undue toxicity to normal tissue. By comparison, negatron-emitting phosphorus-32 as colloidal chromic phosphate had no antineoplastic activity. The most compelling explanation for this striking difference is the dense ionization and short range of action associated with α-emission. These results have important implications for the development and use of α-emitters as radiocolloid therapy for the treatment of human tumors.
Cholecystokinin Antibody Injected in Cerebral Ventricles Stimulates Feeding in Sheep
Authors: Della-Fera Mary Anne , Baile Clifton A. , Schneider Bruce S. , Grinker Joel A.
Published: October 2006

The role of brain cholecystokinin peptides in satiety was further assessed by using antibody to cholecystokinin to reduce cholecystokinin activity in the cerebrospinal fluid of sheep. Food intakes were increased approximately 100 percent during the 2-hour continuous injection of antibody into the cerebrospinal fluid. This supports the hypothesis that, during feeding, cholecystokinin is released into the cerebrospinal fluid, which transports it to the receptors that elicit satiety.