bluuebunny/crossref_metadata_2025 huggingface dataset:
Electronic Databases
Authors: Williams Martha E.
Published: October 2006

Electronic databases corresponding to most of the world's currently published literature and many other types of information are publicly available through online systems. Scientific databases that give references for publications are numerous and widely used; scientific numeric databases that are open to the public are far fewer and less used. Online retrieval systems are becoming easier to use as a result of the introduction of artificial intelligence techniques and user-friendly front ends and gateways. Issues related to electronic databases include public-private sector competition, transborder data flow, copyright, downloading, and the changing roles in database generation and processing.
Expression of the Major Surface Antigen of
Plasmodium knowlesi
Sporozoites in Yeast
Authors: Sharma Shobhona , Godson G. Nigel
Published: October 2006

The circumsporozoite protein, a surface antigen of the sporozoite stage of the monkey malarial parasite
Plasmodium knowlesi
, was expressed in the yeast
Saccharomyces cerevisiae
by using an expression vector containing the 5′ regulatory region of the yeast alcohol dehydrogenase I gene. It was necessary to eliminate the entire 5′ upstream region of the parasite DNA to obtain the expression of this protein. Only the circumsporozoite precursor protein was produced by the yeast transformants, as detected by immunoblotting. About 55 and 20 percent of the circumsporozoite protein produced in yeast was associated with the 25,000
g
and 150,000
g
particulate fractions, respectively. The protein could be solubilized in Triton X-100 and was stable in solubilized extracts.
High-Affinity Uptake of Serotonin Into Immunocytochemically Identified Astrocytes
Authors: Kimelberg H. K. , Katz D. M.
Published: October 2006

Primary cultures of astrocytes from neonatal rat brain were incubated with tritiated serotonin. After fixation they were stained by immunofluorescence for the astrocyte-specific marker glial fibrillary acidic protein and processed for autoradiography. Silver grain density was increased over cells positive for glial fibrillary acidic protein and was reduced to background levels when sodium was omitted from the medium or the specific inhibitors of serotonin uptake fluoxetine and chlorimipramine were present. The results indicate that mammalian astrocytes can take up serotonin by a sodium-dependent, high-affinity system previously thought to be the exclusive property of serotonergic nerve endings.
Natural Plant Chemicals: Sources of Industrial and Medicinal Materials
Authors: Balandrin Manuel F. , Klocke James A. , Wurtele Eve Syrkin , Bollinger Wm. Hugh
Published: October 2006

Many higher plants produce economically important organic compounds such as oils, resins, tannins, natural rubber, gums, waxes, dyes, flavors and fragrances, pharmaceuticals, and pesticides. However, most species of higher plants have never been described, much less surveyed for chemical or biologically active constituents, and new sources of commercially valuable materials remain to be discovered. Advances in biotechnology, particularly methods for culturing plant cells and tissues, should provide new means for the commercial processing of even rare plants and the chemicals they produce. These new technologies will extend and enhance the usefulness of plants as renewable resources of valuable chemicals. In the future, biologically active plant-derived chemicals can be expected to play an increasingly significant role in the commercial development of new products for regulating plant growth and for insect and weed control.
Naturally Occurring Antibodies Reactive with Sperm Proteins: Apparent Deficiency in AIDS Sera
Authors: Rodman Toby C. , Laurence Jeffrey , Pruslin Fred H. , Chiorazzi Nicholas , Winston Ronald
Published: October 2006

A set of naturally occurring immunoglobulin M (IgM) antibodies that are reactive with a defined subset of proteins in the acrosomal cap region of human sperm has been identified. These antibodies are present in a broad spectrum of human sera from males and females, 1 day to 40 years of age, and are absent or markedly deficient in a large proportion of sera from individuals with the acquired immune deficiency syndrome (AIDS) or at risk for AIDS. The subset of proteins with which the IgM antibodies are reactive includes a factor (or factors) capable of inhibiting lectin-induced T-lymphocyte proliferation. The prevalence of the sperm-reactive IgM antibodies indicates that they are not elicited by sperm. Further, immunoreactivity of the sperm proteins resulting in depletion of specific circulating IgM antibodies, or other interactions between the sperm proteins and elements of the immune system, may be a factor in the suppressed state of the immune system in AIDS.
Aromatic-Aromatic Interaction: A Mechanism of Protein Structure Stabilization
Authors: Burley S. K. , Petsko G. A.
Published: October 2006

Analysis of neighboring aromatic groups in four biphenyl peptides or peptide analogs and 34 proteins reveals a specific aromatic-aromatic interaction. Aromatic pairs (< 7 Å between phenyl ring centroids) were analyzed for the frequency of pair type, their interaction geometry (separation and dihedral angle), their nonbonded interaction energy, the secondary structural locations of interacting residues, their environment, and their conservation in related molecules. The results indicate that on average about 60 percent of aromatic side chains in proteins are involved in aromatic pairs, 80 percent of which form networks of three or more interacting aromatic side chains. Phenyl ring centroids are separated by a preferential distance of between 4.5 and 7 Å, and dihedral angles approaching 90° are most common. Nonbonded potential energy calculations indicate that a typical aromatic-aromatic interaction has an energy of between -1 and -2 kilocalories per mole. The free energy contribution of the interaction depends on the environment of the aromatic pair. Buried or partially buried pairs constitute 80 percent of the surveyed sample and contribute a free energy of between -0.6 and -1.3 kilocalories per mole to the stability of the protein's structure at physiologic temperature. Of the proteins surveyed, 80 percent of these energetically favorable interactions stabilize tertiary structure, and 20 percent stabilize quaternary structure. Conservation of the interaction in related molecules is particularly striking.
Amino Terminal Myristylation of the Protein Kinase p60
src
, a Retroviral Transforming Protein
Authors: Schultz Alan M. , Henderson Louis E. , Oroszlan Stephen , Garber Ellen A. , Hanafusa Hidesaburo
Published: October 2006

The transforming protein of Rous sarcoma virus, p60
src
, was shown to be acylated at its amino terminus with the long-chain fatty acid myristic acid by isolation of a tryptic peptide with the following structure: myristylglycylserylseryllysine. The occurrence of this unusual posttranslational modification in the cyclic adenosine monophosphate-dependent protein kinase and in several transforming protein kinases of mammalian retroviruses suggests that myristylation of the amino terminal glycyl residue may be critical for the function of certain proteins related to cell transformation and growth control.
Insulin Mediators from Rat Skeletal Muscle Have Differential Effects on Insulin-Sensitive Pathways of Intact Adipocytes
Authors: Jarett Leonard , Wong Ellen H. A. , Macaulay S. Lance , Smith Judith A.
Published: October 2006

The effects of partially purified insulin-generated mediators from rat skeletal muscle were compared to those of insulin on intact adipocytes. Insulin and insulin mediator stimulated both pyruvate dehydrogenase and glycogen synthase activity of intact adipocytes. In contrast, insulin stimulated glucose oxidation and 3-
O
-methylglucose transport, whereas insulin-generated mediators had no effect. Insulin-generated mediators cannot account for all the pleiotropic effects of insulin, especially membrane-controlled processes.
Inhibition of Calcification of Bioprosthetic Heart Valves by Local Controlled-Release Diphosphonate
Authors: Levy Robert J. , Wolfrum Jacqueline , Schoen Frederick J. , Hawley Marguerite A. , Lund Sally Anne , Langer Robert
Published: October 2006

Bioprostheses fabricated from porcine aortic valves are widely used to replace diseased heart valves. Calcification is the principal cause of the clinical failure of these devices. In the present study, inhibition of the calcification of bioprosthetic heart valve cusps implanted subcutaneously in rats was achieved through the adjacent implantation of controlled-release matrices containing the anticalcification agent ethanehydroxydiphosphonate dispersed in a copolymer of ethylene-vinyl acetate. Prevention of calcification was virtually complete, without the adverse effects of retarded bone and somatic growth that accompany systemic administration of ethanehydroxydiphosphonate.
Detection of Serum Antibodies to Borna Disease Virus in Patients with Psychiatric Disorders
Authors: Rott R. , Herzog S. , Fleischer B. , Winokur A. , Amsterdam J. , Dyson W. , Koprowski H.
Published: October 2006

Borna disease virus causes a rare meningoencephalitis in horses and sheep and has been shown to produce behavioral effects in some species. The possibility that the Borna virus is associated with mental disorders in humans was evaluated by examining serum samples from 979 psychiatric patients and 200 normal volunteers for the presence of Borna virus-specific antibodies. Antibodies were detected by the indirect immunofluorescence focus assay. Antibodies to the virus were demonstrated in 16 of the patients but none of the normal volunteers. The patients with the positive serum samples were characterized by having histories of affective disorders, particularly of a cyclic nature. Further studies are needed to define the possible involvement of Borna virus in human psychiatric disturbances.
Immunohistochemical Localization in the Rat Brain of the Precursor for Thyrotropin-Releasing Hormone
Authors: Jackson Ivor M. D. , Wu Ping , Lechan Ronald M.
Published: October 2006

A rabbit antiserum to a peptide sequence present in the precursor for thyrotropin-releasing hormone (proTRH), deduced from cloned amphibian-skin complementary DNA, was raised by immunization with the synthetic decapeptide Cys-Lys-Arg-Gln-His-Pro-Gly-Lys-Arg-Cys (proTRH-SH). Immunohistochemical studies on rat brain tissue showed staining of neuronal perikarya in the parvicellular division of the paraventricular nucleus of the hypothalamus and the raphe complex of the medulla, identical to that already described for thyrotropin-releasing hormone (TRH). Immunostaining was abolished by preincubation with proTRH-SH (10
-6
M
) but not TRH (10
-5
M
). Both TRH precursor and TRH were located in neurons of the paraventricular nucleus. However, in contrast to the findings for TRH, no staining was observed in axon terminals of the median eminence. These results suggest that a TRH precursor analogous to that reported in frog skin is present in the rat brain and that TRH in the mammalian central nervous system is a product of ribosomal biosynthesis.
Cyanobacterial Light-Harvesting Complex Subunits Encoded in Two Red Light-Induced Transcripts
Authors: Conley Pamela B. , Lemaux Peggy G. , Grossman Arthur R.
Published: October 2006

The major light-harvesting complex in cyanobacteria and red algae, the phycobilisome, is composed of chromophoric and nonchromophoric polypeptides. Two linked genes encoding major chromophoric components, the polypeptide subunits of phycocyanin, were isolated from the cyanobacterium
Fremyella diplosiphon
. Transcripts from this phycocyanin subunit gene cluster were present as major species in the cyanobacterium grown in red light, but not in cultures maintained in green light. The genes for the subunits of the red light-induced phycocyanin were transcribed together (β-phycocyanin followed by α-phycocyanin) on two messenger RNA species; one contained 1600 bases while the other had 3800 bases. The latter, which encompassed the smaller transcript, contained additional sequences extending from the 3′ end of the coding region of the α-phycocyanin gene. It may encode other light-induced components of the phycobilisome. Since phycocyanin, which effectively absorbs red light, becomes a dominant constituent of the phycobilisome in red light, these different levels may reflect an important adaptive mechanism of these organisms to their environment.
A Balanced Translocation in Mice with a Neurological Defect
Authors: Rutledge J. C. , Cain K. T. , Cacheiro N. L. A. , Cornett C. V. , Wright C. G. , Generoso W. M.
Published: October 2006

A semisterile male translocation heterozygote [t(2; 14) 1Gso] that exhibited neurological symptoms and an inability to swim (diver) was found among the offspring of male mice treated with triethylenemelamine. All breeding and cytogenetic data showed a complete concordance between translocation heterozygosity and the neurological disorders. Homozygosity for the translocation seemed to be lethal at an early embryonic stage. Despite the distinctive neurologic symptoms, no anatomic or histological defects in either the ear or in the central nervous system were observed. Thus, a balanced chromosomal translocation can produce disease with an inheritance pattern that mimics a single dominant gene defect.
Genetic Control of Melatonin Synthesis in the Pineal Gland of the Mouse
Authors: Ebihara Shizufumi , Marks Theodore , Hudson David J. , Menaker Michael
Published: October 2006

Pineal melatonin may play an important role in regulation of vertebrate circadian rhythms and in human affective disorders. In some mammals, such as hamsters and sheep, melatonin is involved in photoperiodic time measurement and in control of reproduction. Although wild mice (
Mus domesticus
) and some wild-derived inbred strains of mice have melatonin in their pineal glands, several inbred strains of laboratory mice (for example, C57BL/6J) were found not to have detectable melatonin in their pineal glands. Genetic analysis suggests that melatonin deficiency in C57BL/6J mice results from mutations in two independently segregating, autosomal recessive genes. Synthesis of melatonin from serotonin in the pineal gland requires the enzymes
N
-acetyltransferase (NAT) and hydroxyindole-
O
-methyltransferase (HIOMT). Pineal glands from C57BL/6J mice have neither NAT nor HIOMT activity. These results suggest that the two genes involved in melatonin deficiency are responsible for the absence of normal NAT and HIOMT enzyme activity.
Anti-idiotypic Antibody Vaccine for Type B Viral Hepatitis in Chimpanzees
Authors: Kennedy Ronald C. , Eichberg Jorg W. , Lanford Ronald E. , Dreesman Gordon R.
Published: October 2006

Anti-idiotypic antibodies (anti-Id) that contain an internal image component that mimics the surface antigen of hepatitis B virus (HBsAg) were used to immunize chimpanzees. Four injections of the rabbit anti-Id preparation elicited an antibody response to HBsAg (anti-HBs). The antibody specificity appeared to be against the anti-Id, since the anti-Id immunogen was shown to bind the chimpanzee anti-HBs. Two chimpanzees immunized with the anti-Id, along with two control animals that were either untreated or received a nonimmune rabbit immunoglobulin G preparation, were challenged with infectious hepatitis B virus. Both control chimpanzees developed clinical and serological characteristics consistent with an active hepatitis B virus infection, whereas the two anti-Id treated chimpanzees were protected from infection. Since chimpanzees provide a relevant model of a human response to hepatitis B virus immunization and infection, these results indicate that anti-Id preparations such as that described here might be candidates for vaccines against human diseases.
Bioavailability of Dioxin in Soil from a 2,4,5-T Manufacturing Site
Authors: Umbreit Thomas H. , Hesse Elizabeth J. , Gallo Michael A.
Published: October 2006

Dioxin (2,3,7,8-tetrachlorodibenzo-
p
-dioxin, TCDD) is a highly toxic contaminant produced in the manufacture of phenoxy herbicides. Despite its high TCDD content, soil from a contaminated area associated with a 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) manufacturing site in Newark, New Jersey, did not induce acute toxicity when administered to guinea pigs (the most sensitive species) by gavage. Analysis of liver samples demonstrated low bioavailability of TCDD from this soil. A comparative analysis of soils showed that Soxhlet extraction was necessary for the determination of TCDD on Newark soil, whereas solvent extraction was sufficient for soil from Times Beach, Missouri. The difference in the bioavailability of TCDD from these soils is correlated with TCDD extractability and may be related to the different compositions of the soils.
Selective Loss of a Family of Gene Transcripts in a Hereditary Murine Cataract
Authors: Garber A. T. , Winkler C. , Shinohara T. , King C. R. , Inana G. , Piatigorsky J. , Gold R. J. M.
Published: October 2006

The eye lens of the Fraser mouse contains a dominantly inherited cataract with reduced amounts of seven distinct but homologous γ crystallins encoded by a family of γ-crystallin genes. The results of experiments with cultured lenses, cell-free RNA translation, and Northern blot hybridization indicated a specific loss of the family of γ-crystallin messenger RNA's in the Fraser mouse lens. Southern blot hybridization of genomic DNA's from normal and Fraser mice showed no differences in γ-crystallin coding sequences.
Prolactin Stimulation of Maternal Behavior in Female Rats
Authors: Bridges Robert S. , DiBiase Rosemarie , Loundes Donna D. , Doherty Paul C.
Published: October 2006

Inexperienced, hypophysectomized female rats treated with steroids were used in experiments to investigate the roles of the pituitary gland and prolactin in the expression of maternal behavior. Administration of ovine prolactin or treatment with ectopic pituitary grafts, which release prolactin into the circulation, stimulated maternal care in these females toward rat young. Steroid treatment alone, while stimulating maternal behavior in rats with intact pituitary glands, did not facilitate maternal responsiveness in hypophysectomized females. These findings indicate a stimulatory behavioral role for pituitary prolactin in the establishment of maternal care and suggest that exposure to prolactin during pregnancy helps to stimulate the immediate onset of maternal behavior at parturition.
Sculpting Horizons in Organic Chemistry
Authors: Trost Barry M.
Published: October 2006

Organic chemistry as a discipline derives from and impacts on the biological and abiological world in which we live. Its challenges lie in the areas of structure, reactivity, techniques, and concepts. Powerful structural tools reveal structures from biology that range from control of insect development and behavior to whole new metabolic pathways in humans. Unnatural products create beautiful new molecular shapes whose properties cannot be predicted as well as catalysts that function with enzyme-like control. From structure flows reactivity. Exploration of known reactions points to new directions, and development of new reactions offers the opportunity of streamlined synthetic design. Emerging new techniques offer new dimensions for performing and studying reactions as well as the hope for developing new ones. Merging disparate facts into unified concepts increases predictive capabilities. The extraordinary difficulty of finding the resultant of many small effects may obscure the presence of general theories, creates the art in the practice of the science, and challenges the practitioner. From these general themes derives the quest for selectivity—chemo-, regio-, diastereo-, and enantio-. An examination of the fundamental underpinnings of the applications of organic chemistry reveals that, while impressive strides have been made, the science is best described as being between infancy and childhood. The cross-fertilization between organic chemistry and molecular biology vividly illustrates a merging of chemistry and biology.
Effects on
Trichinella spiralis
of Host Responses to Purified Antigens
Authors: Silberstein David S. , Despommier Dickson D.
Published: October 2006

Purification of two antigens (48-kilodalton polypeptide and a group with major subunits of 50 and 55 kilodaltons) from the infective larvae of the parasitic nematode
Trichinella spiralis
was recently reported. Immunization of mice with either of these antigens induces strong resistance to a subsequent challenge infection. In the study reported here the mechanism of this resistance was investigated by monitoring the parasite's life cycle in mice immunized with the antigens. Immunized mice were able to expel intestinal adult worms and to inhibit the fecundity of adult female worms at an accelerated rate compared to control mice. Accelerated expulsion and inhibition of fecundity may account entirely for the level of resistance induced by immunization. Although the effects of the immune response apparently are exerted on adult worms, the target antigens are expressed only by developing larvae. This suggests that immune effector mechanisms act on intestinal larvae in such a way that they develop into defective adults.
Regional Myocardial Substrate Uptake in Hypertensive Rats: a Quantitative Autoradiographic Measurement
Authors: Yonekura Yoshiharu , Brill A. Bertrand , Som Prantika , Yamamoto Kazutaka , Srivastava Suresh C. , Iwai Junichi , Elmaleh David R. , Livni Eli , Strauss H. William , Goodman Mark M. , Knapp Furn F.
Published: October 2006

Severe hypertension causes global and regional changes in myocardial perfusion and substrate utilization. Regional perfusion and fatty acid utilization were evaluated by dual-tracer autoradiography in normotensive and hypertensive rats of the Dahl strain. The regional distributions of perfusion and fatty acid utilization were homogeneous in normotensive rats. Severe hypertension was associated with a homogeneous pattern of regional perfusion, but fatty acid utilization was focally decreased in the free wall of the left ventricle. The decrease in fatty acid uptake was associated with a concomitant increase in glucose utilization. These findings suggest that severe hypertension is associated with uniform myocardial perfusion and focal alterations in the substrates used for the performance of myocardial work.
Plasma Homovanillic Acid Concentration and the Severity of Schizophrenic Illness
Authors: Davis Kenneth L. , Davidson Michael , Mohs Richard C. , Kendler Kenneth S. , Davis Bonnie M. , Johns Celeste A. , DeNigris Yvonne , Horvath Thomas B.
Published: October 2006

Concentrations of plasma homovanillic acid before treatment were highly correlated with global severity of illness in schizophrenic patients, both before and after treatment. In contrast, a fixed dose of haloperidol did not affect those concentrations. Thus, in patients with a diagnosis of schizophrenia, plasma homovanillic acid may reflect the severity of illness, but not be influenced by short-term pharmacological perturbations by neuroleptics.
Detection of a Cellular Oncogene in Spontaneous Liver Tumors of B6C3F1 Mice
Authors: Fox Tony R. , Watanabe Philip G.
Published: October 2006

An active cellular oncogene was demonstrated in hepatocellular neoplasms arising spontaneously in 24-month-old B6C3F1 mice. DNA isolated from the tumorous tissue and transfected into NIH 3T3 cells showed an 82 percent (9 of 11 animals) frequency of foci induction. In contrast, DNA isolated from the surrounding nontumorous hepatic tissue from the same animals and DNA from other 24-month-old B6C3F1 mice without tumors did not cause transformation in the NIH 3T3 cell assay. This strain of mouse is used extensively in carcinogen bioassays, and the observed high frequency of transformation (82 percent, compared to 10 to 20 percent in humans) supports the concept that the B6C3F1 mouse is hypersusceptible to liver tumor development. It also emphasizes the need to further understand the mechanisms of oncogene activation in animals used for long-term studies of toxicity and oncogenicity before evaluating potential human risk.
Computer Graphics Representation of Levels of Organization in Tobacco Mosaic Virus Structure
Authors: Namba Keiichi , Caspar Donald L. D. , Stubbs Gerald J.
Published: October 2006

Methods for simplifying computer graphics images of atomic models of complex macromolecular assemblies have been applied to the tobacco mosaic virus structure to display different levels of its organization. By constructing sharply outlined pictures of the parts of the virus particle with the image resolution reduced or with obscuring detail eliminated, aspects of the subunit packing and chain folding are distinctly illustrated.
Defect in Vitamin B
12
Release from Lysosomes: Newly Described Inborn Error of Vitamin B
12
Metabolism
Authors: Rosenblatt David S. , Hosack Angela , Matiaszuk Nora V. , Cooper Bernard A. , Laframboise Rachel
Published: October 2006

Cultured diploid fibroblasts from a patient with a previously undescribed inborn error of cobalamin metabolism accumulate unmetabolized, nonprotein-bound vitamin B
12
in lysosomes. These cells are able to endocytose the transcobalamin II-B
12
complex and to release B
12
from transcobalamin II. The freed vitamin B
12
is not released from lysosomes into the cytoplasm of the cell. This suggests that there is a specific lysosomal transport mechanism for vitamin B
12
in the human.
The Brain Connection: The Corpus Callosum Is Larger in Left-Handers
Authors: Witelson Sandra F.
Published: October 2006

The size of the midsagittal area of the human corpus callosum obtained from postmortem measurement varied with tested hand preference. The corpus callosum, the main fiber tract connecting the two cerebral hemispheres, was larger by about 0.75 square centimeter, or 11 percent, in left-handed and ambidextrous people than in those with consistent right-hand preference. The difference was present in both the anterior and posterior halves, but not in the region of the splenium itself. This callosal morphology, which varied with hand preference, may also be related to individual differences in the pattern of hemispheric functional specialization. The greater bihemispheric representation of cognitive functions in left- and mixed-handers may be associated with greater anatomical connection between the hemispheres. The naturally occurring regressive events in neurogenesis, such as neuronal cell death and axonal elimination, may be factors in the individual differences in brain morphology and in functional lateralization. Specifically, right-handers may be those with more extensive early elimination of neural components.
Nucleotide Sequence of Yellow Fever Virus: Implications for Flavivirus Gene Expression and Evolution
Authors: Rice Charles M. , Lenches Edith M. , Eddy Sean R. , Shin Se Jung , Sheets Rebecca L. , Strauss James H.
Published: October 2006

The sequence of the entire RNA genome of the type flavivirus, yellow fever virus, has been obtained. Inspection of this sequence reveals a single long open reading frame of 10,233 nucleotides, which could encode a polypeptide of 3411 amino acids. The structural proteins are found within the amino-terminal 780 residues of this polyprotein; the remainder of the open reading frame consists of nonstructural viral polypeptides. This genome organization implies that mature viral proteins are produced by posttranslational cleavage of a polyprotein precursor and has implications for flavivirus RNA replication and for the evolutionary relation of this virus family to other RNA viruses.
Selective Attention Gates Visual Processing in the Extrastriate Cortex
Authors: Moran Jeffrey , Desimone Robert
Published: October 2006

Single cells were recorded in the visual cortex of monkeys trained to attend to stimuli at one location in the visual field and ignore stimuli at another. When both locations were within the receptive field of a cell in prestriate area V4 or the inferior temporal cortex, the response to the unattended stimulus was dramatically reduced. Cells in the striate cortex were unaffected by attention. The filtering of irrelevant information from the receptive fields of extrastriate neurons may underlie the ability to identify and remember the properties of a particular object out of the many that may be represented on the retina.
Lysis of Human Cultured Lymphoblastoid Cells by Cell-Induced Activation of the Properdin Pathway
Authors: Theofilopoulos Argyrios N. , Perrin Luc H.
Published: October 2006

Human cultured lymphoblastoid cells incubated in normal human serum activate the properdin complement pathway without antibody. However, only cells bearing C3b immune adherence receptors bind components of the properdin complement pathway and undergo lysis. A similar surveillance mechanism may exist in man to limit growth of malignant B cells bearing C3b immune adherence receptors.
Angiotensin Injected into the Neostriatum After Learning Disrupts Retention Performance
Authors: Morgan John M. , Routtenberg Aryeh
Published: October 2006

Angiotensin II, injected into the dorsal neostriatum of rats 5 minutes after they had learned a passive avoidance task, disrupted the retention of the task 24 hours later. Identical neostriatal injections given 22 hours after learning (2 hours before retention) were without effect on retention performance. Ventral neostriatum or posterior thalamus were ineffective sites for injection of angiotensin. Injection of thyrotropin releasing hormone or lysine-8-vasopressin into the dorsal neostriatum was ineffective. These findings indicate a possible role for endogenous angiotensin in the neostriatum on retention performance and suggest potential involvement in mnemonic processes.
Enhanced Metabolism of
Leishmania donovani
Amastigotes at Acid
p
H: an Adaptation for Intracellular Growth
Authors: Mukkada Antony J. , Meade John C. , Glaser Theresa A. , Bonventre Peter F.
Published: October 2006

Amastigotes (tissue forms) of
Leishmania donovani
isolated from infected hamster spleens carried out several physiological activities (respiration, catabolism of energy substrates, and incorporation of precursors into macromolecules) optimally at
p
H 4.0 to 5.5. All metabolic activities that were examined decreased sharply above the optimal
p
H. Promastigotes (culture forms), on the other hand, carried out the same metabolic activities optimally at or near neutral
p
H. This adaptation to an acid environment may account in part for the unusual ability of amastigotes to survive and multiply within the acidic environment of the phagolysosomes in vivo.
Spinal Neurons Project to the Dorsal Column Nuclei of Rhesus Monkeys
Authors: Rustioni Aldo
Published: October 2006

Cells of origin of ascending nonprimary afferents to the dorsal column nuclei of rhesus monkeys have been identified in the spinal cord by the retrograde transport of horseradish peroxidase. These neurons are mainly located in lamina IV and medially in more ventral laminae of the dorsal horn on the side ipsilateral to the medullary injection. Large neurons in the ventral horn ("spinal border cells") also appear to project to the ipsilateral dorsal medulla. The dorsal column nuclei of a primate thus are the recipient not only of ascending dorsal root fibers but also of a more complexly integrated spinal input.
GM
2
Ganglioside Lysosomal Storage Disease in Cats with α-Hexosaminidase Deficiency
Authors: Cork Linda Collins , Munnell John F. , Lorenz Michael D. , Murphy Jerome V. , Baker Henry J. , Rattazzi Mario C.
Published: October 2006

Two kittens with progressive neurologic disease had increased concentrations of GM
2
ganglioside in their cerebral cortex. Examination under the light microscope revealed cytoplasmic vacuolation of neurons and hepatocytes. Transmission and scanning electron microscopy demonstrated cytoplasmic inclusions encompassed by membranes in various central nervous system cell types and in hepatocytes. Beta-D-
N
-acetyl-hexosaminidase activity was reduced to about 1.0 percent of normal in brain, liver, and cultured skin fibroblasts of the diseased kittens; both major electrophoretic forms, A and B, of the enzyme were deficient. In fibroblasts from the parents of the diseased kittens, this enzyme activity was intermediate between that of affected and normal cats, suggesting an autosomal recessive mode of inheritance of the enzyme defect. Histopathological and ultrastructural lesions, glycolipid storage, enzyme defect, and pattern of inheritance are similar to those of human GM
2
gangliosidosis type 2.
Asymptomatic Gonorrhea in Men: Caused by Gonococci with Unique Nutritional Requirements
Authors: Crawford George , Knapp Joan S. , Hale Judith , Holmes King K.
Published: October 2006

In a retrospective case-control study, gonococci with nutritional requirements for arginine, hypoxanthine, and uracil were recovered from 24 of 25 men with asymptomatic gonorrhea and 10 of 25 men with symptomatic gonorrhea (
P
= .0001). These strains represent a smaller proportion of gonococcal isolates from blacks than from whites. Asymptomatic urethral infection is important in the epidemiology of gonorrhea, particularly among whites.
Temporal Control of Urate Oxidase Activity in
Drosophila
: Evidence of an Autonomous Timer in Malpighian Tubules
Authors: Friedman Thomas B. , Johnson Daniel H.
Published: October 2006

The appearance of urate oxidase activity in the Malpighian tubules of
Drosophila melanogaster
is synchronized with the time of emergence of the imago from the puparium. A developmental clock within the Malpighian tubules specifies the time of appearance of urate oxidase activity.
Synthesis and Evaluation of a Prototypal Artificial Red Cell
Authors: Hunt C. Anthony , Burnette Ronald R. , MacGregor Roderick D. , Strubbe Anne E. , Lau Daniel T. , Taylor Noel , Kiwada Hiroshi
Published: October 2006

A new process allows microencapsulation of purified human hemoglobin and 2,3-diphosphoglycerate to form neohemocytes. The microcapsule membrane is composed of phospholipids and cholesterol. Neohemocytes are substantially smaller than erythrocytes, contain 15.1 grams per decaliter of hemoglobin, and have a P
50
value (the partial pressure of oxygen at which the hemoglobin is half-saturated) of 24.0 torr. All rats given 50-percent exchange transfusions survived with only limited evidence of reversible toxicity. Normal serum glutamate-pyruvate-transaminase values at 1, 7, and 30 days after transfusion were consistent with minimal hepatotoxicity. The concentration of blood urea-nitrogen was elevated by 35 percent after 1 day but returned to normal by day 7. However, histopathology revealed normal kidneys on day 1 as well as on days 7 and 30. Neohemocytes cleared from the circulation of transfused rats with an apparent half-life of 5.8 hours.
The Role of Macrophages in Particle Translocation from Lungs to Lymph Nodes
Authors: Harmsen Allen G. , Muggenburg Bruce A. , Snipes M. Burton , Bice David E.
Published: October 2006

Red fluorescent and green fluorescent microspheres were instilled into separate but adjacent areas of dog lung lobes. After 7 days, the tracheobronchial lymph nodes that drained both of the instilled areas contained many macrophages with all red or all green microspheres but rarely both. This indicates that the particles did not translocate passively and that lung macrophages phagocytized the microspheres in the lung and carried them to the tracheobronchial lymph nodes. In addition, two populations of pulmonary alveolar macrophages (PAM's), one that had phagocytized red microspheres in vivo and one that had phagocytized green microspheres, were lavaged from the lungs of dogs, mixed into one population, and instilled back into a previously unexposed lung lobe of the same dogs. As in the first experiment, the tracheobronchial lymph nodes that drained the instilled area contained numerous macrophages with either all red or all green microspheres. This suggested that the instilled PAM's had migrated to the tracheobronchial lymph nodes. Thus, lung macrophages, including PAM's, probably play a critical role in the induction of lung immunity and in protection from disease by determining particle translocation.
Foreign Aid Support of Science and Economic Growth
Authors: Szmant H. Harry
Published: October 2006

The history of U.S. foreign aid support of science and technology in Latin America is examined and an attempt is made to evaluate the scientific and economic growth of that area in relation to the total foreign aid effort.
B Lymphocyte Antigens in Sicca Syndrome
Authors: Moutsopoulos Haralampos M. , Chused Thomas M. , Johnson Armead H. , Khudsen Bodil , Mann Dean L.
Published: October 2006

All individuals tested in this study with sicca syndrome, a human autoimmune disease, bear two immunologically distinct and genetically unrelated B lymphocyte antigens that appear similar to the immune response associated (Ia) antigens of the mouse. The genes coding for these two antigens are present in only 37 and 24 percent of normal controls. In animal models Ia antigen genes are closely linked to immune response genes. Our findings suggest that two such genes may be required for the development of sicca syndrome.
Circadian Rhythm of Serotonin
N
-Acetyltransferase Activity in Organ Culture of Chicken Pineal Gland
Authors: Deguchi Takeo
Published: October 2006

When chicken pineal glands were organ-cultured in darkness, serotonin
N
-acetyltransferase activity was low during daytime, increased at midnight, and decreased on the next morning. The autonomous increase of
N
-acetyltransferase activity was suppressed by illumination of the glands. When pineal glands were cultured under a light-dark cycle (LD 12:12), the change of
N
-acetyltransferase activity continued to oscillate in phase with the light-dark cycle for 3 days.
Premature Senescence in Cultured Skin Fibroblasts from Subjects with Cystic Fibrosis
Authors: Shapiro Burton L. , Lam Louis F.-H. , Fast Lorraine H.
Published: October 2006

Cultured skin fibroblasts from subjects with cystic fibrosis exhibited normal population doubling times in early passages. After about 13 cumulative population doublings, cystic fibrosis lines doubled more slowly than controls and ceased doubling after about 19 weekly passages. Control lines continued doubling for 27 passages. The premature senescence noted in cells from subjects with cystic fibrosis reconciles controversial observations of cell doubling reported in the literature. Data presented here demonstrate that experiments with cystic fibrosis cells in late passage may generate misleading results since differences from control lines may be ascribed to generalized senile changes rather than to specific results of the cystic fibrosis genotype.
Smooth Pursuit Eye Movements: Is Perceived Motion Necessary?
Authors: Mack Arien , Fendrich Robert , Pleune Joan
Published: October 2006

It has recently been shown that perceived motion, in the absence of any appropriate retinal motion, is a sufficient stimulus to generate smooth pursuit eye motions. This raises the question of whether perceived motion is necessary for pursuit. In three experiments we obtained a negative answer to this question: retinal motion always governed pursuit.
Distribution of RNA Transcripts from Structural and Intervening Sequences of the Ovalbumin Gene
Authors: Tsai Ming-Jer , Tsai Sophia Y. , O'Malley Bert W.
Published: October 2006

A study was made of the function of the intervening sequences in the ovalbumin gene, Radioactively labeled DNA probes for the intervening sequences were prepared and RNA's were isolated from whole cells, nuclei, and polysomes of estrogen-stimulated chick oviducts. The concentrations of messenger RNA (mRNA) transcripts from ovalbumin structural sequences (mRNA
ov
) and transcripts corresponding to intervening sequences were then estimated by hybridization to cloned DNA probes. Oviduct tissue contains approximately 58,000 molecules of mRNA
ov
sequences per tubular gland cell and most of these sequences are present in the cytoplasm. In contrast, there are 200 to 300 molecules of RNA per cell which are transcribed from the intervening sequences of the natural ovalbumin gene and almost all of these are found in the nucleus. The difference in distribution of structural and intervening sequence transcripts suggests that, unlike mature mRNA, the intervening sequences are not preferentially transported to cytoplasmic polysomes.
Clomid Administration to Pregnant Rats Causes Abnormalities of the Reproductive Tract in Offspring and Mothers
Authors: McCormack Shirley , Clark James H.
Published: October 2006

In rats, a single injection of clomiphene citrate (Clomid) during pregnancy causes multiple abnormalities of the reproductive tract in the offspring and mothers. These abnormalities probably result from the ability of Clomid to cause long-term estrogenic stimulation.
Structure of Physiologically Identified X and Y Cells in the Cat's Lateral Geniculate Nucleus
Authors: Friedlander Michael J. , Lin C. S. , Sherman S. Murray
Published: October 2006

Horseradish peroxidase injected into 18 single, physiologically identified geniculate X and Y cells permitted a detailed morphological correlate to be determined for the physiological properties of each neuron. Class 1 morphological characteristics were associated with Y cells, class 3 with X cells, and class 2 structural traits were seen in both physiological types.
Canine
Babesia
New to North America
Authors: Anderson John F. , Magnarelli Louis A. , Donner Christopher S. , Spielman Andrew , Piesman Joseph
Published: October 2006

A domestic dog residing in New England suffered a fatal febrile illness caused by a
Babesia
infection. The morphology of these intraerythrocytic protozoa and the range of hosts that could be infected experimentally suggested that the parasite was
B. gibsoni
. Although this tick-borne disease is enzootic in wild and domestic Canidae in Africa and Asia, it appears to be new to the Americas.
Feeding and Behavioral Activation in Infant Rats
Authors: Hall W. G.
Published: October 2006

Three-day-old rats that were separated from their mothers and deprived of food were found to be capable of feeding either from small puddles of milk or when milk was infused into the front of their mouths. Such feeding was accompanied by a dramatic increase in behavioral activity and only occurred in a warm environment. These data demonstrate that neural systems for ingestive behavior are present at birth and suggest the existence of feeding-related arousal or motivational systems.
Host Defense Against
Neisseria meningitidis
Requires a Complement-Dependent Bactericidal Activity
Authors: Nicholson Anne , Lepow Irwin H.
Published: October 2006

Some individuals, with severe or recurrent infection with
Neisseria
species, have been identified as lacking a component in the terminal attack sequence of complement (complement components 5 to 9). The relevance of the terminal attack sequence to various phases of host defense was tested with the use of the C-11 strain of meningococci and human serum genetically deficient in complement component 8 (C8-D). The C8-D serum was comparable to normal serum in supporting ingestion and intracellular killing by leukocytes but was not bactericidal in the fluid phase unless reconstituted with C8. Thus, serum complement-dependent bactericidal activity may be especially critical for the host's defense against invasive
Neisseria
species.
Albumin-Deficient Rat Mutant
Authors: Nagase Sumi , Shimamune Kane , Shumiya Seigo
Published: October 2006

An analbuminemic colony was established from Sprague-Dawley rats. Analbuminemia was inherited as an autosomal recessive trait. The rates of growth and reproduction of the mutant rats were no different from those of normal rats. Biochemically, the mutant was characterized by an extraordinarily low serum albumin content and a hyperlipidemia. Total serum protein in the mutant rat was similar to that of control Sprague-Dawley rats, with increased globulin. Serum cholesterol was inversely correlated with a decrease in albumin; the correlation coefficient for ablumin was -.92. These mutant rats may serve as a model of human familial analbuminemia and may also be useful in elucidating the functional roles of albumin.
Endogenous Inhibitor of Colchicine-Tubulin Binding in Rat Brain
Authors: Sherline Peter , Schiavone Karen , Brocato Susan
Published: October 2006

A competitive inhibitor of colchicine binding to tubulin has been found in rat brain. Most of the inhibitor is associated with microsomes but some inhibitor, with an apparent molecular weight of approximately 250,000, is found in the cytosol. Both the microsomal and cytosol inhibitors are heat- and trypsin-sensitive, indicating that a protein moiety is required for activity. The microsomes bind tubulin directly; the microsomal and cytosol fractions both inhibit microtubule assembly in vitro. The inhibitor may function in the living cell to bind and sequester non-polymerized tubulin. Regulation of tubulin attachment to microsomes could then control the concentration of cytosolic tubulin available for microtubule assembly.
DNA Synthesis and Mitosis in Adult Amphibian Cardiac Muscle Cells in Vitro
Authors: Nag Asish C. , Healy Christopher J. , Cheng Mei
Published: October 2006

High-resolution autoradiography and fine structural analysis of adult newt heart tissue in long-term culture revealed that tritiated thymidine was concentrated in the nuclei of dedifferentiated myocardial cells. Mitotic chromosomes were observed in some of these cells. This demonstrates that adult amphibian myocardial cells in vitro are capable of DNA synthesis and mitosis.
Baroreceptor Activation Reduces Reactivity to Noxious Stimulation: Implications for Hypertension
Authors: Dworkin B. R. , Filewich R. J. , Miller N. E. , Craigmyle N. , Pickering T. G.
Published: October 2006

The hypothesis was tested that an acute rise of blood pressure may reduce reactivity to noxious stimuli through a baroreceptor-mediated reduction of cerebral arousal. When blood pressure was raised by an infusion of phenylephrine, rats showed less running to terminate or avoid noxious stimuli than during saline infusions. This effect was not seen in rats with denervated baroreceptors. The results suggest that a rise of blood pressure could have motivational consequences significant for human hypertension.
Meiotic Maturation in
Xenopus laevis
Oocytes Initiated by Insulin
Authors: El-Etr Martine , Schorderet-Slatkine Sabine , Baulieu Etienne-Emile
Published: October 2006

Insulin can induce meiotic division in
Xenopus laevis
oocytes. This effect shows the specificity expected of a receptor-mediated mechanism. It is potentiated by ethynylestradiol, a steroid antagonist of progesterone (the natural hormone that provokes meiosis). The
Xenopus laevis
oocytes may serve as a model for the study of the poorly understood effect of insulin on cell division.
Pseudohermaphroditism in
Ilyanassa obsoleta
(Mollusca: Neogastropoda)
Authors: Jenner Martha Garrett
Published: October 2006

Field studies, a rearing and maintenance program, and a transfer experiment have shown that anomalous male traits found in some female
Ilyanassa obsoleta
are an expression of environmentally controlled pseudohermaphroditism. The particular pattern of pseudohermaphroditism discovered in this species has not been reported previously from any other group, but may be characteristic of the Neogastropoda.
Correct Axonal Regeneration After Target Cell Removal in the Central Nervous System of the Leech
Authors: Muller Kenneth J. , Scott Sheryl A.
Published: October 2006

The unique target neuron of a severed axon in the leech was selectively eliminated by intracellular injection of protease. In the absence of the target, the severed axon regenerated normally along its original pathway to the usual site of synapse, where it stopped growing without forming alternative connections.