bluuebunny/crossref_metadata_2025 huggingface dataset:
Pituitary Receptor Site Blockade by a Gonadotropin-Releasing Hormone Antagonist in Vivo: Mechanism of Action
Authors: Heber D. , Dodson R. , Swerdloff R. S. , Channabasavaiah K. , Stewart J. M.
Published: October 2006

Administration of a potent gonadotropin-releasing hormone (GnRH) antagonist [Nac-L-Ala
1
,pCl-D-Phe
2
,D-Trp
3,6
]GnRH as a single subcutaneous injection to castrated adult male rats reduced, by more than 90 percent, both serum luteinizing hormone concentrations and specific pituitary GnRH receptor binding. This effect persisted for 24 hours. The dissociation rate of the antagonist from pituitary membrane homogenates was fourfold slower than the dissociation rate of a potent agonist. The prolonged in vivo inhibition of pituitary GnRH receptor binding and luteinizing hormone secretion by the GnRH antagonist may be mediated by the slower dissociation rate of the antagonist from its specific pituitary membrane receptor site.
Stereoselective Antagonism of Phencyclidine's Discriminative Properties by Adenosine Receptor Agonists
Authors: Browne Ronald G. , Welch Willard M.
Published: October 2006

Rats trained to discriminate between phencyclidine and saline vehicle were used to test various agents for their ability to mimic or block the phencyclidine cue. Ketamine, dexoxadrol, tiletamine, and phencyclidine analogs were found to mimic phencyclidine's behavioral effects. Treatment with the adenosine receptor agonists
N
6
-cyclohexyladenosine and L-phenylisopropyladenosine blocked the discriminative properties of phencyclidine. These results suggest that adenosine receptor agonists might be useful in treating phencyclidine-induced psychosis.
Herpes Simplex Virus Type-1 Glycoprotein D Gene: Nucleotide Sequence and Expression in
Escherichia coli
Authors: Watson Roger J. , Weis John H. , Salstrom John S. , Enquist Lynn W.
Published: October 2006

The protein coding region of the herpes simplex virus type-1 glycoprotein D (gD) gene was mapped, and the nucleotide sequence was determined. The predicted amino acid sequence of the gD polypeptide was found to contain a number of features in common with other virus glycoproteins. Insertion of this protein coding region into a bacterial expressor plasmid enabled synthesis in
Escherichia coli
of an immunoreactive gD-related polypeptide. The potential of this system for preparation of a type-common herpes simplex virus vaccine is discussed.
Molecular Biology of Learning: Modulation of Transmitter Release
Authors: Kandel Eric R. , Schwartz James H.
Published: October 2006

Until recently, it has been impossible to approach learning with the techniques of cell biology. During the past several years, elementary forms of learning have been analyzed in higher invertebrates. Their nervous systems allow the experimental study of behavioral, neurophysiological, morphological, biochemical, and genetic components of the functional (plastic) changes underlying learning. In this review, we focus primarily on short-term sensitization of the gill and siphon reflex in the marine mollusk,
Aplysia californica
. Analyses of this form of learning provide direct evidence that protein phosphorylation dependent on cyclic adenosine monophosphate can modulate synaptic action. These studies also suggest how the molecular mechanisms for this short-term form of synaptic plasticity can be extended to explain both long-term memory and classical conditioning.
Chromosomal Localization of the Human Homolog (c-
sis
) of the Simian Sarcoma Virus
onc
Gene
Authors: Dalla-Favera Riccardo , Gallo Robert C. , Giallongo Agata , Croce Carlo M.
Published: October 2006

Nonrandom chromosome rearrangements of chromosome 22 have been identified in different human malignancies. As a result of Southern blot hybridization of a c-
sis
probe to DNA's from mouse-human somatic cell hybrids, the human homolog (c-
sis
) of the transforming gene of simian sarcoma virus was assigned to chromosome 22. Hybrids between thymidine kinase-deficient mouse cells and human fibroblasts carrying a translocation of the region q11-qter of chromosome 22 to chromosome 17 were also analyzed. These studies demonstrate that the human c-
sis
gene is on region 22q11>qter.
Crypts Are the Site of Intestinal Fluid and Electrolyte Secretion
Authors: Welsh Michael J. , Smith Philip L. , Fromm Michael , Frizzell Raymond A.
Published: October 2006

The site of adenosine 3′,5′-monophosphate-mediated fluid and electrolyte secretion across mammalian large intestine was found to be the crypts of Lieberkühn by means of two techniques. First, the formation of fluid droplets was visualized on the oil-covered mucosal surface directly over crypt duct openings when secretion was stimulated. Second, microelectrode impalement of individual surface and crypt cells revealed that only the crypt cells produced a pattern of secretagogue-induced alterations in membrane potential and resistance that was characteristic of secretory epithelia.
Eukaryotic Transcriptional Regulation and Chromatin-Associated Protein Phosphorylation by Cyclic AMP
Authors: Murdoch Geoffrey H. , Rosenfeld Michael G. , Evans Ronald M.
Published: October 2006

Cyclic adenosine monophosphate (AMP) analogs or agents that increase intracellular cyclic AMP rapidly stimulate transcription of the prolactin gene in a line of cultured rat pituitary cells. This effect is correlated with the phosphorylation of a chromatin-associated basic protein designated BRP. These data are consistent with the postulate that increased intracellular cyclic AMP concentrations induce rapid transcriptional effects on specific genes in eukaryotes, mediated by direct or indirect phosphorylation of a specific chromatin-associated protein or proteins.
Rabies Virus Glycoprotein Analogs: Biosynthesis in
Escherichia coli
Authors: Yelverton Elizabeth , Norton Shirley , Obijeski John F. , Goeddel David V.
Published: October 2006

The surface of rabies virus is composed of an approximately 60,000 dalton glycoprotein, in which most of the antigenic and immunogenic determinants of the virus reside. We have constructed plasmids for the direct expression in
Escherichia coli
of the mature full length rabies glycoprotein gene and also for the expression of a glycoprotein gene which has been truncated to exclude the coding region for a hydrophobic, possibly transmembrane, domain of the protein.
Escherichia coli
harboring the plasmids synthesize analog proteins which conform by several biochemical and antigenic criteria to rabies glycoprotein.
Serum Ferritin as a Predictor of Host Response to Hepatitis B Virus Infection
Authors: Lustbader Edward D. , Hann Hie-Won L. , Blumberg Baruch S.
Published: October 2006

With hemodialysis patients, a high serum ferritin before there was serological evidence of hepatitis B virus infection increased the likelihood that the infection would be persistent. This finding suggested that hepatitis B virus is likely to infect and actively replicate in liver cells with the propensity for increased ferritin synthesis. The virus itself could stimulate the synthesis of ferritin in a cyclic positive feedback mechanism that increases intracellular ferritin concentration and, eventually, intracellular iron. Transformed liver cells have low iron content, do not replicate hepatitis B virus, and require iron for growth. Infected, nonmalignant liver cells could supply iron to the transformed cells and nourish their expansion.
Functional Organization of the Second Cortical Visual Area in Primates
Authors: Tootell Roger B. H. , Silverman Martin S. , De Valois Russell L. , Jacobs Gerald H.
Published: October 2006

The functional organization of the second cortical visual area was examined with three different anatomical markers: 2-[
14
C]deoxy-D-glucose, cytochrome oxidase, and various myelin stains. All three markers revealed strips running throughout the area, parallel to the cortical surface. The boundaries of these strips provide an anatomical criterion for defining the borders of this extrastriate region. Further, the demonstration of these strips allows a functional and anatomical analysis of modules in the area, just as the recent demonstration of spots in the primary visual cortex has allowed an analysis of modules there. The strips differ structurally and functionally from interstrip regions and these differences are similar to those seen between the spots and the interspot regions in the primary visual cortex. In the macaque the strips and spots differ with regard to binocular organization.
Adenosine Receptors: Autoradiographic Evidence for Their Location on Axon Terminals of Excitatory Neurons
Authors: Goodman Robert R. , Kuhar Michael J. , Hester Lynda , Snyder Solomon H.
Published: October 2006

Adenosine receptors were made visible on light microscopy by autoradiography with tritiated cyclohexyladenosine. In the cerebellum, adenosine receptors were absent in Weaver mice, which lack granule cells, and were displaced in Reeler mice, which have displacements of granule cells. Thus, adenosine receptors appear to be located on the axon terminals of excitatory granule cells in the cerebellum. Removal of one eye of a rat depleted adenosine receptors in the contralateral superior colliculus, suggesting that the receptors occur on axon terminals of excitatory projections from retinal ganglion cells. The presence of adenosine receptors on excitatory axon terminals may explain synaptic inhibition by adenosine and the behavioral effects of xanthines.
Simian Sarcoma Virus
onc
Gene, v-
sis
, Is Derived from the Gene (or Genes) Encoding a Platelet-Derived Growth Factor
Authors: Doolittle Russell F. , Hunkapiller Michael W. , Hood Leroy E. , Devare Sushilkumar G. , Robbins Keith C. , Aaronson Stuart A. , Antoniades Harry N.
Published: October 2006

The transforming protein of a primate sarcoma virus and a platelet-derived growth factor are derived from the same or closely related cellular genes. This conclusion is based on the demonstration of extensive sequence similarity between the transforming protein derived from the simian sarcoma virus
onc
gene, v-
sis
, and a human platelet-derived growth factor. The mechanism by which v-
sis
transforms cells could involve the constitutive expression of a protein with functions similar or identical to those of a factor active transiently during normal cell growth.
Minor Histone 2A Variants and Ubiquinated Forms in the Native H2A:H2B Dimer
Authors: Hatch Christopher L. , Bonner William M. , Moudrianakis Evangelos N.
Published: October 2006

Histone octamers from calf thymus were separated into (H3:H4)
2
tetramers and H2A:H2B dimers by chromatography through Sephadex G100. The tetramers and dimers were analyzed for variants, ubiquitin adducts, and proteolyzed forms. The minor histone variants H2A.X and H2A.Z were found to be associated with histone H2B as H2A.X:H2B and H2A.Z:H2B dimers, respectively. Ubiquitin adducts of the H2A's and H2B were also present in H2A:H2B dimers.
Gene for T-Cell Growth Factor: Location on Human Chromosome 4q and Feline Chromosome B1
Authors: Seigel Leonard J. , Harper Mary E. , Wong-Staal Flossie , Gallo Robert C. , Nash William G. , O'Brien Stephen J.
Published: October 2006

T-cell growth factor (TCGF) or interleukin-2 (IL-2), an immunoregulatory lymphokine, is produced by lectin- or antigen-activated mature T lymphocytes and in a constitutive manner by certain T-cell lymphoma cell lines. By means of a molecular clone of human TCGF and DNA extracted from a panel of somatic cell hybrids (rodent cells × normal human lymphocytes), the TCGF structural gene was identified on human chromosome 4. In situ hybridization of the TCGF clone to human chromosomes resulted in significant labeling of the midportion of the long arm of chromosome 4, indicating that the TCGF gene was located at band q26-28. Genomic DNA from a panel of hybrids prepared with HUT-102 B2 cells was examined with the same molecular clone. In this clone of cells, which produces human T-cell leukemia virus, the TCGF gene was also located on chromosome 4 and was apparently not rearranged. The homologous TCGF locus in the domestic cat was assigned to chromosome B1 by using a somatic cell hybrid panel that segregates cat chromosomes. Linkage studies as well as high-resolution G-trypsin banding indicate that this feline chromosome is partially homologous to human chromosome 4.
Salt-Sensitive Hypertension: Contribution of Chloride
Authors: Whitescarver Shirley A. , Ott Cobern E. , Jackson Brian A. , Guthrie Gordon P. , Kotchen Theodore A.
Published: October 2006

The effect of the anion associated with sodium loading on the development of hypertension in the Dahl salt-sensitive rat was determined. For 5 weeks rats were fed a diet containing normal or high concentrations of sodium chloride or high concentrations of sodium provided as a mixture of sodium bicarbonate, phosphate, and amino acids. After 1 week on these diets and until the end of the study the rats receiving high concentrations of sodium chloride had higher systolic blood pressures than the rats in the other two groups. There were no statistically significant group differences in plasma volume, arterial
p
H, or plasma concentrations of Na
+
, K
+
, Cl
-
, Ca2
+
, or creatinine, or in renomedullary prostaglandin E
2
production. Compared to the animals receiving normal concentrations of sodium chloride, those receiving high concentrations of sodium chloride or amino acids showed decreased plasma renin activity and plasma aldosterone concentrations. Thus, the anion ingested with sodium alters the development and severity of hypertension in the Dahl salt-sensitive rat.
Anatomically Distinct Opiate Receptor Fields Mediate Reward and Physical Dependence
Authors: Bozarth Michael A. , Wise Roy A.
Published: October 2006

Rats never before exposed to opioids rapidly learned to press a lever for microinjections of morphine into the ventral tegmental area. Challenge by a narcotic antagonist produced no signs of physical dependence. Dependence was not seen after long-term morphine infusions into the ventral tegmentum but was seen after similar infusions into the periventricular gray region. Thus a major rewarding property of morphine is independent of the drug's ability to produce physical dependence. These data challenge models of drug addiction that propose physical dependence as necessary for the rewarding effects of opioids.
Antigens on HTLV-Infected Cells Recognized by Leukemia and AIDS Sera Are Related to HTLV Viral Glycoprotein
Authors: Schüpbach Jörg , Sarngadharan M. G. , Gallo R. C.
Published: October 2006

Cross-reactive antigens of molecular size of 61,000 to 68,000 daltons are found on the surface of human cells infected by human T-cell leukemia-lymphoma virus (HTLV). They are recognized by antibodies from patients with adult T-cell leukemias and lymphomas, from healthy carriers of HTLV, and from patients with the acquired immunodeficiency syndrome (AIDS). The latter finding has been one of the major reasons for suggesting an association of HTLV with AIDS. However, whether these antigens are of cellular or viral origin has not been clear. These antigens have now been shown to be associated with the presence of viral proteins in the cells, and a cross-reactive glycoprotein of molecular size of 46,000 daltons has been found to be a consistent structural part of viruses purified from several HTLV-producer cell lines. The findings thus suggest a viral (HTLV) origin of these antigens.
The Structural Gene for Tetanus Neurotoxin Is on a Plasmid
Authors: Finn Charles W. , Silver Richard P. , Habig William H. , Hardegree M. Carolyn , Zon Gerald , Garon Claude F.
Published: October 2006

A pool of synthetic oligonucleotides was prepared based on the amino terminal amino acid sequence of tetanus toxin. This probe hybridized to plasmid DNA isolated from three toxigenic strains of
Clostridium tetani
but not to plasmid DNA from a nontoxigenic strain. These results show that the structural gene for the toxin is on the plasmid. The pCL1 plasmid from one of the toxigenic strains spontaneously deleted 22 kilobase pairs of DNA to form pCL2. Strains harboring this deleted plasmid are nontoxigenic. However, the probe mixture hybridized to pCL2, indicating that the DNA encoding the amino terminus of the toxin had not been deleted. Restriction endonuclease cleavage maps of pCL1 and pCL2 were constructed and indicate the approximate location and orientation of the structural gene for tetanus toxin.
Synthetic Competitive Antagonists of Corticotropin-Releasing Factor: Effect on ACTH Secretion in the Rat
Authors: Rivier Jean , Rivier Catherine , Vale Wylie
Published: October 2006

Polypeptide analogs of the known members of the corticotropin-releasing factor (CRF) family were synthesized and tested in vitro and in vivo for enhanced potency or competitive antagonism. Predictive methods and physicochemical measurements had suggested an internal secondary α-helical conformation spanning about 25 residues for at least three members of the CRF family. Maximization of α-helix-forming potential by amino acid substitutions from the native known sequences (rat/human and ovine CRF, sauvagine, and carp and sucker urotensin 1) led to the synthesis of an analog that was found to be more than twice as potent as either of the parent peptides in vitro. In contrast, certain amino-terminally shortened fragments, such as α-helical CRF or ovine CRF residues 8 to 41, 9 to 41, and 10 to 41, were found to be competitive inhibitors in vitro. Selected antagonists were examined and also found to be active in vivo.
Cellular Transformation by Human Papillomavirus DNA in Vitro
Authors: Watts Susan L. , Phelps William C. , Ostrow Ronald S. , Zachow Karen R. , Faras Anthony J.
Published: October 2006

Molecularly cloned DNA's of human papillomaviruses HPV-5 and HPV-1 induced morphological transformation of mouse C127 cells in culture. Single-cell clones of cells transformed by papillomavirus contained multiple persistent episomal copies of the transfected DNA species and were analyzed for growth characteristics indicating malignant potential.
Pargyline Prevents MPTP-Induced Parkinsonism in Primates
Authors: Langston J. William , Irwin Ian , Langston Elizabeth B. , Forno Lysia S.
Published: October 2006

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin which produces permanent parkinsonism in human and nonhuman primates. Treatment of squirrel monkeys with pargyline, a monoamine oxidase (MAO) inhibitor, prevents both clinical and neuropathological evidence of the neurotoxic effects of MPTP. Pargyline also inhibits conversion of MPTP to 1-methyl-4-phenylpyridinium ion (MPP
+
), a metabolic step that occurs rapidly after administration of MPTP in animals not treated with pargyline. It is proposed that the conversion of MPTP to MPP+, possibly involving MAO, may be important for the neurotoxic effects of MPTP to take place, and MPTP itself may not be the neurotoxic agent.
Induction of Interleukin 2 Messenger RNA Inhibited by Cyclosporin A
Authors: Elliott John Francis , Lin Yuan , Mizel Steven B. , Bleackley R. Chris , Harnish Delsworth G. , Paetkau Verner
Published: October 2006

Cyclosporin A blocked production of the lymphokine interleukin 2 by activated T lymphocytes. In a human and a murine cell line this inhibition reflected an absence of interleukin 2 messenger RNA. Under conditions in which these cells are normally stimulated to secrete high levels of interleukin 2, they failed to do so in the presence of cyclosporin A. In both cell lines this failure was accompanied by an absence of interleukin 2 messenger accumulation.
Malaria Parasites Adopt Host Cell Superoxide Dismutase
Authors: Fairfield Alexandra S. , Meshnick Steven R. , Eaton John W.
Published: October 2006

Aerobic organisms depend on superoxide dismutase to suppress the formation of dangerous species of activated oxygen. Intraerythrocytic stages of the malaria parasite exist within a highly aerobic environment and cause the generation of increased amounts of activated oxygen.
Plasmodium berghei
in mice was found to derive a substantial amount of superoxide dismutase activity from the host cell cytoplasm. Plasmodia isolated from mouse red cells contained mouse superoxide dismutase, whereas rat-derived parasites contained the rat enzyme. This is believed to be the first example of the acquisition of a host cell enzyme by an intracellular parasite.
Development of Sensitivity to Pictorial Depth
Authors: Yonas Albert , Cleaves Wallace T. , Pettersen Linda
Published: October 2006

Sensitivity to static pictorial information for depth develops between 22 and 26 weeks of age. When conflicting binocular and surface-texture information was minimized, 26- to 30-week-old infants directed their reaching to the apparently closer side of a photograph of a window rotated in depth. Younger infants, from 20 to 22 weeks of age, did not direct their reaching to the pictorially nearer side of the display but did reach with a high degree of directionality when presented with a real window rotated in depth.
Behavioral Thermoregulation: Orientation Toward the Sun in Herring Gulls
Authors: Luskick Sheldon , Battersby Brian , Kelty Michael
Published: October 2006

Orientation toward the sun combined with postural changes minimized the net radiation gain on the adult herring gull during the breeding season. The decrease in absorbed solar radiation was due to reduced surface area exposed to direct sunlight and to reduced absorptivity since, when the bird orients toward the sun, the angle of incidence is such that only the white surfaces receive direct sunlight. At low wind velocities (0 to 0.6 meter per second) and ambient temperatures above the lower critical temperature, the birds rotated 180 degrees during the day, always facing the sun.
Gyrate Atrophy of the Retina: Inborn Error of L-Ornithin:2-Oxoacid Aminotransferase
Authors: O'Donnell James J. , Sandman Robert P. , Martin Susan R.
Published: October 2006

Cultured fibroblasts from a patient with gyrate atrophy of the retina do not convert L-ornithine, uniformly labeled with carbon-14, to proline. This metabolic block is caused by deficient L-ornithine:2-oxoacid aminotransferase activity in the patient. Her heterozygote father has intermediate activity of this enzyme.
Metallothionein-Human GH Fusion Genes Stimulate Growth of Mice
Authors: Palmiter Richard D. , Norstedt Gunnar , Gelinas Richard E. , Hammer Robert E. , Brinster Ralph L.
Published: October 2006

The promoter or regulatory region of the mouse gene for metallothionein-I was fused to the structural gene coding for human growth hormone. These fusion genes were introduced into mice by microinjection of fertilized eggs. Twenty-three (70 percent) of the mice that stably incorporated the fusion genes showed high concentrations of human growth hormone in their serum and grew significantly larger than control mice. Synthesis of human growth hormone was induced further by cadmium or zinc, which normally induce metallothionein gene expression. Transgenic mice that expressed human growth hormone also showed increased concentrations of insulin-like growth factor I in their serum. Histology of their pituitaries suggests dysfunction of the cells that normally synthesize growth hormone. The fusion genes were expressed in all tissues examined, but the ratio of human growth hormone messenger RNA to endogenous metallothionein-I messenger RNA varied among different tissues and different animals, suggesting that expression of the foreign genes is influenced by site of integration and tissue environment.
Evolution of Proteolytic Enzymes
Authors: Neurath Hans
Published: October 2006

Proteolytic enzymes have many physiological functions, ranging from generalized protein digestion to more specific regulated processes such as the activation of zymogens, blood coagulation and the lysis of fibrin clots, the release of hormones and pharmacologically active peptides from precursor proteins, and the transport of secretory proteins across membranes. They are present in all forms of living organisms. Comparisons of amino acid sequences, three-dimensional structures, and enzymatic reaction mechanisms of proteases indicate that there are distinct families of these proteins. Changes in molecular structure and function have accompanied the evolution of proteolytic enzymes and their inhibitors, each having relatively simple roles in primitive organisms and more diverse and more complex functions in higher organisms.
Fourier Transform Mass Spectrometry
Authors: Gross Michael L. , Rempel Don L.
Published: October 2006

Fourier transform mass spectrometry will play an important role in the future because of its unique combination of high mass resolution, high upper mass limit, and multichannel advantage. These features have already found application in gas chromatography-mass spectrometry, multiphoton ionization, laser desorption, and secondary ion mass spectrometry. However, its most notable feature is the ability to store ions. This characteristic, when combined with the others, will allow expeditious study of the interaction of gas-phase ions with both photons (photodissociation) and neutral molecules, and the convenient application of this fundamental information for chemical analysis.
Nuclear Magnetic Resonance Technology for Medical Studies
Authors: Budinger Thomas F. , Lauterbur Paul C.
Published: October 2006

Nuclear magnetic resonance proton imaging provides anatomical definition of normal and abnormal tissues with a contrast and detection sensitivity superior to those of x-ray computed tomography in the human head and pelvis and parts of the cardiovascular and musculoskeletal systems. Recent improvements in technology should lead to advances in diagnostic imaging of the breast and regions of the abdomen. Selected-region nuclear magnetic resonance spectroscopy of protons, carbon-13, and phosphorus-31 has developed into a basic science tool for in vivo studies on man and a unique tool for clinical diagnoses of metabolic disorders. At present, nuclear magnetic resonance is considered safe if access to the magnet environment is controlled. Technological advances employing field strengths over 2 teslas will require biophysical studies of heating and static field effects.
Salivary Gland Hyperglycemic Factor: An Extrapancreatic Source of Glucagon-Like Material
Authors: Lawrence A. M. , Tan S. , Hojvat S. , Kirsteins L.
Published: October 2006

Extracts of homogenates of rat, mouse, rabbit, and human submaxillary salivary glands contain a significant quantity of a material with glucagon-like immunoreactivity. Fractionation of this material on columns of Sephadex G-100 reveals a single peak immediately following a gamma globulin marker but in advance of a rat growth hormone marker, crystalline amylase, and isotopically labeled porcine insulin and glucagon. This material, which is urea stable, shows identical immunoassay dilution curves when measured with the highly specific K-30 glucagon antiserum. Study of paired glands in vitro shows that low concentrations of glucose stimulate and high concentrations of glucose suppress release of this material. Arginine promotes brisk release in vitro. Somatostatin does not influence arginine-stimulated secretion and insignificantly suppresses basal release in vitro. These findings lend support to previous speculations that the salivary glands may possess endocrine as well as exocrine functions. Salivary gland glucagon may also be the source of circulating glucagon recently reported in pancreatectomized and eviscerated rats.
Translocation and Rearrangements of the c-
myc
Oncogene Locus in Human Undifferentiated B-Cell Lymphomas
Authors: Dalla-Favera Riccardo , Martinotti Stefano , Gallo Robert C. , Erikson Jan , Croce Carlo M.
Published: October 2006

The locus for the cellular
myc
(c-
myc
) oncogene in humans is located on the region of chromosome 8 that is translocated to chromosome 14 in cells from most undifferentiated B-cell lymphomas. It is shown in this study that the c-
myc
locus is rearranged in 5 out of 15 cell lines from patients with undifferentiated B-cell lymphomas, and that the rearrangement involves a region at the 5′ side of an apparently intact c-
myc
gene. In at least three patients, this rearranged region appears to contain immunoglobulin heavy chain μ sequences that are located on chromosome 14. The data indicate that this region contains the crossover point between chromosomes 8 and 14. The break point can occur at different positions on both chromosomes among individual cell lines.
Salt-Induced Conversion of B-DNA to Z-DNA Inhibited by Aflatoxin B1
Authors: Nordheim Alfred , Hao Wei Min , Wogan Gerald N. , Rich Alexander
Published: October 2006

The carcinogen aflatoxin B1 was reacted with a polymer of alternating deoxyguanine and deoxycytosine residues to determine the effect that adduct formation has on the conversion of this polymer from the right-handed B-DNA form found at low salt concentrations to the left-handed Z-DNA form found at high salt concentrations. Reaction with aflatoxin strongly inhibited the salt-induced conversion of this polymer from B-DNA to Z-DNA. This inhibition could be detected even at relatively low binding levels.
Human Monocytes Activated by Immunomodulators in Liposomes Lyse Herpesvirus-Infected But Not Normal Cells
Authors: Koff Wayne C. , Fidler Isaiah J. , Showalter Stephen D. , Chakrabarty Mrinal K. , Hampar Berge , Ceccorulli Lisa M. , Kleinerman Eugenie S.
Published: October 2006

Highly purified peripheral blood monocytes from normal human donors were activated in vitro by incubation with liposomes containing immunomodulators such as recombinant human gamma interferon, human lymphokines, or muramyl dipeptide. The ability of liposomes containing immunomodulators to activate monocytes to a cytotoxic state capable of discriminating between virus-infected and uninfected cells was shown by activated monocytes recognizing and destroying herpes simplex virus type 2-infected cells while leaving uninfected cells unharmed .
Site-Specific Mutagenesis of the Human Interleukin-2 Gene: Structure-Function Analysis of the Cysteine Residues
Authors: Wang Alice , Lu Shi-Da , Mark David F.
Published: October 2006

The gene encoding human interleukin-2 (IL-2) has been cloned from human spleen cells, peripheral blood lymphocytes, and the Jurkat cell line. Nucleotide sequence analysis of the gene revealed that the encoded IL-2 protein has three cysteines located at amino acid residues 58, 105, and 125 of the mature protein. Site-specific mutagenesis procedures were used to modify the IL-2 gene by changing each of the cysteine codons individually to serine codons. Substitution of serine for cysteine residues at either position 58 or 105 of the IL-2 protein substantially reduced biological activity, indicating that the cysteines at these positions are necessary for maintenance of the biologically active conformation and may therefore be linked by a disulfide bridge. The modified IL-2 protein containing a substitution at position 125 retained full biological activity, suggesting that the cysteine at this position is not involved in a disulfide bond and that a free sulfhydryl group at that position is not necessary for receptor binding.
Circadian Rhythms in
Neurospora crassa
: Oligomycin-Resistant Mutations Affect Periodicity
Authors: Diekmann Carol , Brody Stuart
Published: October 2006

Nuclear mutations conferring resistance to oligomycin, a mitochondrial inhibitor, shorten the period of the circadian conidiation rhythm of
Neurospora crassa
from the normal 21.5 hours to 18 to 19 hours and slow the linear growth rate by 30 percent. These
oli
r
mutations map very close to
frq
, a locus at which mutations affecting periodicity have been previously obtained. The possibilities are discussed that mitochondria are involved in circadian rhythm generation and that certain period-length mutations affect mitochondrial functions.
Ontogenetic Changes in Frequency Mapping of a Mammalian Ear
Authors: Harris David M. , Dallos Peter
Published: October 2006

Cochlear microphonic iso-response functions reported here suggest an explanation of frequency-dependent changes in hearing sensitivity during early development. The work is a direct demonstration of developmental changes in the spatial frequency map of the mammalian hearing organ. Intracochlear recordings from the midbasal turn in a series of age-graded gerbils reveal a progressive increase in best frequency, spanning approximately two octaves, from the time of onset of function until adultlike responses are seen. It is, therefore, suggested that ontogenetic changes in the cellular structure of the organ of Corti contribute to an age-dependent shift in micromechanical response.
Enhanced Arboviral Transmission by Mosquitoes That Concurrently Ingested Microfilariae
Authors: Turell M. J. , Rossignol P. A. , Spielman A. , Rossi C. A. , Bailey C. L.
Published: October 2006

Infection, dissemination, and transmission of an arbovirus in mosquitoes are enhanced by concurrent ingestion of microfilariae. Ingestion of Rift Valley fever virus alone infected only 64 percent of female
Aedes taeniorhynchus
. Of these, only 5 percent of refeeding mosquitoes actually transmitted virus. In contrast, ingestion of the same amount of virus from concurrently microfilaremic (
Brugia malayi
) gerbils resulted in 88 percent infection and 31 percent transmission. Enhanced transmission of virus may be attributed to increased transit of virus across the midgut wall. Endemic filariasis may promote arbovirus transmission in nature.
Event-Related Brain Potentials in Boys at Risk for Alcoholism
Authors: Begleiter Henri , Porjesz Bernice , Bihari Bernard , Kissin Benjamin
Published: October 2006

Recent neurophysiological findings have demonstrated that abstinent chronic alcoholics manifest deficits in event-related brain potentials. To explore possible biological antecedents of alcoholism the present study examined boys at high risk for alcoholism. Event-related brain potentials were recorded from biological sons of alcoholic fathers and matched control boys. Differences in the P3 component of the potentials were obtained between the high-risk and control subjects.
Unequivocal Delayed Hypersensitivity in Mast Cell-Deficient and Beige Mice
Authors: Galli Stephen J. , Hammel Ilan
Published: October 2006

It has been suggested that reserpine blocks expression of delayed hypersensitivity in mice because it depletes stores of the vasoactive amine serotonin in mast cells. To determine whether mast cell serotonin or other mast cell-derived mediators are essential for delayed hypersensitivity, responses to contact sensitizers in mast cell-deficient

W/W
v

or

Sl/Sl
d

mice were studied. Because blood platelets represent another potential source of serotonin in delayed hypersensitivity responses, beige mice, whose platelets contain less than 1 percent of the normal levels of serotonin, were also examined. By the criteria of tissue swelling, infiltration of iodinated leukocytes, or histology, mast cell-deficient or beige mice expressed delayed hypersensitivity reactions whose intensity generally equaled or exceeded that of reactions in littermate controls. In addition, reserpine blocked delayed hypersensitivity in

W/W
v

and beige mice, suggesting that effects on mast cell or platelet serotonin cannot explain this drug's action in delayed hypersensitivity.
The Spiracular Organ of Sharks and Skates: Anatomical Evidence Indicating a Mechanoreceptive Role
Authors: Barry Michael A. , Boord Robert L.
Published: October 2006

The elasmobranch spiracular organ is a specialized receptor associated with the first visceral pouch. The structure of the sensory epithelium of the spiracular organ and the pattern of central termination of the afferent neurons that innervate it show that the spiracular organ is a mechanoreceptor closely related to the lateral line system of sense organs. Its position and orientation within the spiracular cleft suggest that it plays a role in proprioception or equilibrium-audition.
Initiation of Behavior by Single Neurons: The Role of Behavioral Context
Authors: Nolen T. G. , Hoy R. R.
Published: October 2006

Flying crickets avoid sources of ultrasound, possibly echolocating bats, by making rapid steering movements that turn them away from the stimulus. Electrical stimulation of a single, identified sensory interneuron (Int-1) elicits avoidance steering; depressing its response to ultrasound abolishes avoidance steering. Int-1 is necessary and sufficient for this behavior but only while the cricket is in flight. Thus, the sufficiency of Int-1 for eliciting this behavior is contingent on behavioral context.
Hemoglobin I Mutation Encoded at Both α-Globin Loci on the Same Chromosome: Concerted Evolution in the Human Genome
Authors: Liebhaber Stephen A. , Rappaport Eric F. , Cash Faith E. , Ballas Samir K. , Schwartz Elias , Surrey Saul
Published: October 2006

Genetic analysis of an individual expressing an unexpectedly high level of hemoglobin I, an α-globin structural mutant, reveals that the mutation is present at both the α1- and the α2-globin gene loci. Kindred analysis confirms that the two affected genes are located in
cis
. The most likely explanation for this finding is that a recent conversion event occurred within the human α-globin gene cluster.
Isolation and Transmission of Human Retrovirus (Human T-Cell Leukemia Virus)
Authors: Popovic M. , Sarin P. S. , Robert-Gurroff M. , Kalyanaraman V. S. , Mann D. , Minowada J. , Gallo R. C.
Published: October 2006

Nine new isolates of human T-cell leukemia-lymphoma virus (HTLV) were obtained from cells of seven patients with malignancies of mature T cells and from two clinically normal relatives of a T-cell leukemia patient. These people were from the United States, Israel, the West Indies, and Japan. The virus was detected in the fresh T cells and was isolated from the established T-cell lines. Each isolate is closely related to the first HTLV isolate, and all the new HTLV isolates were transmitted into normal human T cells obtained from the umbilical cord blood of newborns.
Imaging Dopamine Receptors in the Human Brain by Positron Tomography
Authors: Wagner Henry N. , Burns H. Donald , Dannals Robert F. , Wong Dean F. , Langstrom Bengt , Duelfer Timothy , Frost J. James , Ravert Hayden T. , Links Jonathan M. , Rosenbloom Shelley B. , Lukas Scott E. , Kramer Alfred V. , Kuhar Michael J.
Published: October 2006

Neurotransmitter receptors may be involved in a number of neuropsychiatric disease states. The ligand 3-
N
-[
11
C]methylspiperone, which preferentially binds to dopamine receptors in vivo, was used to image the receptors by positron emission tomography scanning in baboons and in humans. This technique holds promise for noninvasive clinical studies of dopamine receptors in humans.
Proliferation of Astroglia and Oligodendroglia in Response to Human T Cell-Derived Factors
Authors: Merrill J. E. , Kutsunai S. , Mohlstrom C. , Hofman F. , Groopman J. , Golde D. W.
Published: October 2006

Human T lymphocytes transformed by human T cell leukemia-lymphoma viruses or activated by lectins were found to produce stimulating factors that promoted both proliferation and maturation of oligodendroglial and astroglial cells in vitro.
Effects of Rectilinear Acceleration and Optokinetic and Caloric Stimulations in Space
Authors: von Baumgarten R. , Benson A. , Berthoz A. , Brandt Th. , Brand U. , Bruzek W. , Dichgans J. , Kass J. , Probst Th. , Scherer H. , Vieville T. , Vogel H. , Wetzig J.
Published: October 2006

During the flight of Spacelab 1 the crew performed a number of experiments to explore changes in vestibular function and visual-vestibular interactions on exposure to microgravity. Measurements were made on the threshold for detection of linear oscillation, vestibulo-ocular reflexes elicited by angular and linear movements, oculomotor and posture responses to optokinetic stimulations, and responses to caloric stimulation. Tests were also conducted on the ground, during the 4 months before and on days 1 to 6 after flight. The most significant result was that caloric nystagmus of the same direction as on the earth could also be evoked in the weightless environment.
Increased Brain Size and Cellular Content in Infant Rats Treated with an Opiate Antagonist
Authors: Zagon Ian S. , McLaughlin Patricia J.
Published: October 2006

From birth to day 21, rat offspring received daily injections of naltrexone at a dosage that blocked morphine-induced analgesia 24 hours a day. At 21 days, body, brain, and cerebellar weights of naltrexone-injected animals were 18, 11, and 5 percent greater than corresponding control weights. In addition, morphometric analysis of the cerebrum revealed a somatosensory cortex that was 18 percent thicker than that of the controls. The cerebellum of naltrexone-treated rats was 41 percent larger in total area and contained at least 70 percent more glial cells and 30 percent more granule neurons. Neurons derived prenatally were unaffected by drug treatment. These results show that naltrexone can stimulate body and brain growth in rats and suggest a role for the endorphin and opiate receptor system in development.
Paedomorphosis and Neoteny in the Pygmy Chimpanzee
Authors: Shea Brian T.
Published: October 2006

The strongly paedomorphic skull form in the pygmy chimpanzee results from the heterochronic process of neoteny. This cranial paedomorphosis and neoteny in
Pan paniscus
may be related to reduced sexual dimorphism in morphology and behavior. The interspecific differences in form result from shifts in the rate and timing of similar patterns of development.
Nicarbazin Complex Yields Dinitrocarbanilide as Ultrafine Crystals with Improved Anticoccidial Activity
Authors: Rogers Edward F. , Brown Ronald D. , Brown Jeannette E. , Kazazis Diana M. , Leanza William J. , Nichols John R. , Ostlind Dan A. , Rodino Toni M.
Published: October 2006

Nicarbazin, a drug used to control the protozoal disease coccidiosis in poultry, is a complex of the highly insoluble drug 4,4′-dinitrocarbanilide with 2-hydroxy-4,6-dimethylpyrimidine. The structures of this and other 4,4′-dinitrocarbanilide complexes have not been determined, but an analogous 2:1 complex of 4,4′-dinitrodiphenylamine with 1,4-diacetylpiperazine has been prepared in which the only possible bonds are hydrogen bonds between the amide carbonyls and amino hydrogens. Scanning electron microscopy revealed that micron-size crystals of nicarbazin disintegrate in water to form much smaller dinitrocarbanilide crystals. Similar complex dissolution in the gut of poultry may account for the greater effectiveness of dinitrocarbanilide when administered as complexed rather than uncomplexed drug. Particle size problems associated with other highly insoluble drugs and pesticides may be resolved by the use of nicarbazin-like complexes.
Nitrite and Nitrate Are Formed by Endogenous Synthesis in the Human Intestine
Authors: Tannenbaum S. R. , Fett D. , Young V. R. , Land P. D. , Bruce W. R.
Published: October 2006

Studies of nitrate balance in humans and analyses of fecal and ileostomy samples indicate that nitrite and nitrate are formed de novo in the intestine, possibly by heterotrophic nitrification. These findings significantly alter our previous conceptions of human exposure to nitrite and suggest an even wider role for nitrite in the etiology of human cancer.
Cystic Fibrosis: Decreased Conjugation and Excretion of [
14
C]Spermidine
Authors: Rosenblum Michael G. , Durie Brian G. M. , Beckerman Robert C. , Taussig Lynn M. , Russell Diane Haddock
Published: October 2006

Free and conjugated [
14
C]spermidine were measured in plasma samples from normal individuals and cystic fibrosis patients. Within 4 minutes, the
14
C-labeled material in the plasma from normal individuals was 70 percent conjugated compared to no detectable conjugation by cystic fibrosis patients. Further, the patients excreted only 11 to 13 percent of the [
14
C]spermidine in their urine within 72 hours whereas normal excretion was 60 to 76 percent. In both cases, the labeled material was in a conjugated form.
Peptide Formation in the Prebiotic Era: Thermal Condensation of Glycine in Fluctuating Clay Environments
Authors: Lahav N. , White D. , Chang S.
Published: October 2006

As geologically relevant models of prebiotic environments, systems consisting of clay, water, and amino acids were subjected to cyclic variations in temperature and water content. Fluctuations of both variables produced longer oligopeptides in higher yields than were produced by temperature fluctuations alone. The results suggest that fluctuating environments provided a favorable geological setting in which the rate and extent of chemical evolution would have been determined by the number and frequency of cycles.
Monensin and the Prevention of Tryptophan-Induced Acute Bovine Pulmonary Edema and Emphysema
Authors: Hammond A. C. , Carlson J. R. , Breeze R. G.
Published: October 2006

3-Methylindole, a ruminal fermentation product of tryptophan, induces acute pulmonary edema and emphysema in cattle, and 3-methylindole is present in the ruminal fluid and blood of cows with a naturally occurring form of this disease. Monensin, a polyether antibiotic and widely used feed additive for beef cattle, prevented tryptophan-induced acute bovine pulmonary edema and emphysema. Monensin acted by reducing the ruminal conversion of L-tryptophan to 3-methylindole both in vitro and in vivo. Lasalocid, also a polyether antibiotic, showed similar effects in vitro. These results provide a promising approach to prevention of this major respiratory disease of cattle.
Sex Differences in Mathematical Reasoning Ability: More Facts
Authors: Benbow Camilla Persson , Stanley Julian C.
Published: October 2006

Almost 40,000 selected seventh-grade students from the Middle Atlantic region of the United States took the College Board Scholastic Aptitude Test as part of the Johns Hopkins regional talent search in 1980, 1981, and 1982. A separate nationwide talent search was conducted in which any student under age 13 who was willing to take the test was eligible. The results obtained by both procedures establish that by age 13 a large sex difference in mathematical reasoning ability exists and that it is especially pronounced at the high end of the distribution: among students who scored ≥ 700, boys outnumbered girls 13 to 1. Some hypothesized explanations of such differences were not supported by the data.
Long-Term Biological Consequences of Nuclear War
Authors: Ehrlich Paul R. , Harte John , Harwell Mark A. , Raven Peter H. , Sagan Carl , Woodwell George M. , Berry Joseph , Ayensu Edward S. , Ehrlich Anne H. , Eisner Thomas , Gould Stephen J. , Grover Herbert D. , Herrera Rafael , May Robert M. , Mayr Ernst , McKay Christopher P. , Mooney Harold A. , Myers Norman , Pimentel David , Teal John M.
Published: October 2006

Subfreezing temperatures, low light levels, and high doses of ionizing and ultraviolet radiation extending for many months after a large-scale nuclear war could destroy the biological support systems of civilization, at least in the Northern Hemisphere. Productivity in natural and agricultural ecosystems could be severely restricted for a year or more. Postwar survivors would face starvation as well as freezing conditions in the dark and be exposed to near-lethal doses of radiation. If, as now seems possible, the Southern Hemisphere were affected also, global disruption of the biosphere could ensue. In any event, there would be severe consequences, even in the areas not affected directly, because of the interdependence of the world economy. In either case the extinction of a large fraction of the Earth's animals, plants, and microorganisms seems possible. The population size of Homo sapiens conceivably could be reduced to prehistoric levels or below, and extinction of the human species itself cannot be excluded.
How a Nerve Fiber Repairs Its Cut End: Involvement of Phospholipase A2
Authors: Yawo Hiromu , Kuno Motoy
Published: October 2006

Following transection of a giant axon, the nerve membrane at the cut end is resealed within 5 to 30 minutes. This membrane resealing process is highly dependent upon temperature and extracellular calcium ions. The membrane resealing is triggered by excess calcium entering the axoplasm at the site of transection but is prevented by the application of phospholipase A2inhibitors. We propose that calcium activated phospholipase A2plays a central role in resealing of the ruptured nerve membrane.