bluuebunny/crossref_metadata_2025 huggingface dataset:
Coordinate Hormonal and Synaptic Regulation of Vasopressin Messenger RNA
Authors: Baldino Frank , O'Kane Teresa M. , Fitzpatrick-McElligott Sandra , Wolfson Betty
Published: October 2006

Previous studies have shown that adrenalectomy augments arginine vasopressin (AVP) messenger RNA levels in the adult paraventricular nucleus. It is now demonstrated that unilateral lesions in the lateral septal nucleus enhance the adrenalectomy-induced expression of AVP mRNA. This effect was entirely ipsilateral to the lesion and most prominent in the rostral paraventricular nucleus and related nuclei. Moreover, AVP and AVP mRNA were found to be colocalized with oxytocin in a few neurons. These results indicate that mRNA expression is modulated by synaptic influences and raise the possibility that synaptically mediated selection of neuronal phenotypes is a dynamic feature of the mature central nervous system.
Absence of Linkage of Chromosome 21q21 Markers to Familial Alzheimer's Disease
Authors: Schellenberg Gerard D. , Bird Thomas D. , Wijsman Ellen M. , Moore Deborah K. , Boehnke Michael , Bryant Eileen M. , Lampe Thomas H. , Nochlin David , Sumi Shuzo M. , Deeb Samir S. , Beyreuther Konrad , Martin George M.
Published: October 2006

Alzheimer's disease is the most common form of dementia among the elderly population. Although the etiology is unknown, inheritance plays a role in the pathogenesis of the disease. Recent work indicates that an autosomal dominant gene for Alzheimer's disease is located on chromosome 21 at band q21. In the present study of a group of autopsy-documented kindreds, no evidence for linkage was found between familial Alzheimer's disease (FAD) and chromosome 21q21 markers (D21S1/D21S72 and the amyloid β gene). Linkage to the D21S1/D21S72 locus was excluded at recombination fractions (θ) up to 0.17. Linkage to the amyloid gene was excluded at θ = 0.10. Apparent recombinants were noted in two families for the amyloid gene and in five families for the D21S1/D21S72 locus. These data indicate that FAD is genetically heterogeneous.
Interferon and c-
ets
-1 Genes in the Translocation (9;11)(p22;q23) in Human Acute Monocytic Leukemia
Authors: Diaz Manuel O. , Le Beau Michelle M. , Pitha Paula , Rowley Janet D
Published: October 2006

Gene probes for interferons α and β
1
and v-
ets
were hybridized to metaphase chromosomes from three patients with acute monocytic leukemia who had a chromosomal translocation, t(9;11)(p22;q23). The break in the short arm of chromosome 9 split the interferon genes, and the interferon-β
1
gene was translocated to chromosome 11. The c-
ets
-1 gene was translocated from chromosome 11 to the short arm of chromosome 9 adjacent to the interferon genes. No DNA rearrangement was observed when these probes were hybridized to genomic DNA from leukemic cells of two of the patients. The results suggest that the juxtaposition of the interferon and c-
ets
-1 genes may be involved in the pathogenesis of human monocytic leukemia.
Identification by Cell Fusion of Gene Sequences That Interact with Positive Trans-Acting Factors
Authors: Lufkin Thomas , Bancroft Carter
Published: October 2006

Cell fusion experiments have implicated positive or negative regulatory factors in the cell type—specific expression of specialized endogenous genes. The inability to readily manipulate such genes has prevented characterization of the cis-acting DNA sequences that interact with these factors. A transfection-fusion technique, which combined stable gene transfer and formation of transient heterokaryons, was used to study this class of factors and their DNA binding sites. Messenger RNA directed by a quiescent, rat prolactin promoter region stably transferred into mouse fibroblasts was detected only after fusion to rat pituitary cells, implying that pituitary cells contain a positive cell type—specific factor or factors. Nuclear run-on assays showed that fusion activation is transcriptional. Fusion did not activate either a stably transferred rat growth hormone gene promoter or expression of the endogenous silent fibroblast prolactin or growth hormone genes. Analysis by 5′-deletion mutation identified a 30-base pair DNA sequence required for cell fusion activation of the rat prolactin promoter region. Comparison with previous results from direct cellular transfer of this region implies that transfection-fusion identifies novel regulatory DNA sequences.
Tripeptide Structure of Bursin, a Selective B-Cell-Differentiating Hormone of the Bursa of Fabricius
Authors: Audhya Tapan , Kroon Daniel , Heavner George , Viamontes George , Goldstein Gideon
Published: October 2006

Differentiation of lymphoid precursor cells in a variety of species is induced by polypeptide hormones such as thymopoietin for T cells and bursin for B cells. In the present experiments, bursin isolated from the bursa of Fabricius of chicken was found to induce the phenotypic differentiation of mammalian and avian B precursor cells but not of T precursor cells in vitro. Similarly, bursin increased cyclic guanosine monophosphate in cells of the human B-cell line Daudi but not in cells of the human T-cell line CEM. These inducing properties of bursin are the reverse of the inducing properties of thymopoietin produced by the thymus and are appropriate to a physiological B-cell-inducing hormone. A tripeptide sequence (lysyl-histidyl-glycyl-amide) was determined for bursin and confirmed by synthesizing this proposed structure and demonstrating chemical identity of the natural and synthetic peptides. Similarity of biological action was indicated in induction assays by elevation of cyclic adenosine monophosphate and guanosine monophosphate in Daudi B cells but not in CEM T cells.
Lymphotoxin Is an Important T Cell-Derived Growth Factor for Human B Cells
Authors: Kehrl John H. , Alvarez-Mon Melchor , Delsing Gita A. , Fauci Anthony S.
Published: October 2006

Two different assays for B cell growth factors (BCGF) and an antibody against lymphotoxin were used to show that the presence of lymphotoxin in conditioned media derived from normal activated T cells and in a partially purified BCGF accounts for a substantial portion of their B cell growth-promoting activity. A competitive binding assay confirmed the presence of significant amounts of lymphotoxin in the partially purified BCGF. Recombinant lymphotoxin enhanced the proliferation of activated B cells and augmented B cell proliferation and immunoglobulin secretion induced by interleukin-2.
Reversible Interconversion of Two Forms of a Valyl-tRNA Synthetase-Containing Protein Complex
Authors: Black Simon
Published: October 2006

When an enzyme-containing complex from yeast was incubated in a buffered solution at room temperature, the valyl-transfer RNA synthetase activity and total protein oscillated synchronously between two physical states. This observation suggests a regulatory process that controls a number of enzymes as a group, an integrated function of a kind not heretofore recognized. The two forms of the complex were separated by ammonium sulfate precipitation of one of them in samples withdrawn from the incubated solution every 30 seconds. Glutathione and dithiothreitol in high concentrations (50 m
M
) enhance formation of the 50% saturated ammonium sulfate-soluble form. Oxidized glutathione, diphosphopyridine nucleotide, triphosphopyridine nucleotide, and a mercurial thiol binding agent in moderate concentrations (0.1 to 1.0 m
M
) shift the distribution toward the precipitable form. It is suggested that the two forms represent functional and nonfunctional complex-bound enzymes which are interconverted in response to oxidoreductive signals.
Glucocorticoid Receptor Mutants That Define a Small Region Sufficient for Enhancer Activation
Authors: Miesfeld Roger , Godowski Paul J. , Maler Bonnie A. , Yamamoto Keith R.
Published: October 2006

Transcriptional enhancement is a general mechanism for regulation of gene expression in which particular proteins bound to specific DNA sequences stimulate the efficiency of initiation from linked promoters. One such protein, the glucocorticoid receptor, mediates enhancement in a glucocorticoid hormone-dependent manner. In this study, a region of the 795-amino acid rat glucocorticoid receptor that is active in transcriptional enhancement was identified. The active region was defined by expressing various receptor deletion mutants in stably and transiently transfected cells and examining the regulated transcription of hormone-responsive genes. Mutant receptors lacking as many as 439 amino-terminal amino acids retained activity, as did those with as many as 270 carboxyl-terminal amino acids deleted. This suggests that the 86-amino acid segment between the most extensive terminal deletions, which also includes sequences required for specific DNA binding in vitro, is sufficient for enhancer activation. In fact, a 150-amino acid receptor fragment that encompasses this segment mediates constitutive enhancement.
Recombinant Interferon Enhances Monoclonal Antibody-Targeting of Carcinoma Lesions in Vivo
Authors: Greiner John W. , Guadagni Fiorella , Noguchi Philip , Pestka Sidney , Colcher David , Fisher Paul B. , Schlom Jeffrey
Published: October 2006

Heterogeneity in the expression of tumor-associated antigens, as defined by the binding of monoclonal antibodies, is a characteristic common to most, if not all, human carcinoma cell populations. Antigen-negative cells within the population can escape detection and therapy by their failure to bind the appropriate antibody. Therefore, the extent of antigenic heterogeneity is an important consideration when designing protocols for the management of cancer by administration of monoclonal antibodies. One approach to counteracting the effect of antigenic heterogeneity is the use of clone A of recombinant human leukocyte interferon (Hu-IFN-αA). Administration of Hu-IFN-αA in vivo effectively increased the amount of tumor antigen expressed by a human colon xenograft in situ and augmented the localization of a radiolabeled monoclonal antibody to the tumor site. Concomitant administration of Hu-IFN-αA and monoclonal antibody may thus be effective in overcoming the antigenic heterogeneity of carcinoma cell populations and in enhancing the efficacy of monoclonal antibodies in the detection and treatment of carcinoma lesions.
The Visual Cycle Operates via an Isomerase Acting on All-
trans
Retinol in the Pigment Epithelium
Authors: Bridges C. David , Alvarez Richard A.
Published: October 2006

Thirty years have elapsed since Wald and his colleagues showed that 11-
cis
retinal was isomerized to all-
trans
when rhodopsin was bleached, yet little has been understood about the reverse process that generates 11-
cis
retinal for rhodopsin regeneration. It is not known whether the isomerization is enzyme-mediated, whether it occurs in the pigment epithelium or in the retina, or whether retinal, retinol, or a retinyl ester is the vitamin A compound that is isomerized. Radiolabeled all-
trans
retinol and high-performance liquid chromatography have now been used to demonstrate the existence of an eye-specific, membrane-bound enzyme (retinol isomerase) that converts all-
trans
to 11-
cis
retinol in the dark. Retinol isomerase is concentrated in the pigment epithelium; this localization clarifies the role of this tissue in rhodopsin regeneration and explains the need to transfer all-
trans
retinol from the rod outer segments to the pigment epithelium during the visual cycle.
Oncogenes in Radioresistant, Noncancerous Skin Fibroblasts from a Cancer-Prone Family
Authors: Chang Esther H. , Pirollo Kathleen F. , Zou Zhi Qiang , Cheung Hon-Yeung , Lawler Elsbeth Lee , Garner Rosa , White Elizabeth , Bernstein Wendy B. , Fraumeni Joseph W. , Blattner William A.
Published: October 2006

Li-Fraumeni syndrome is manifested in a variety of neoplasms that are transmitted in a dominantly inherited pattern. The noncancerous skin fibroblasts of family members exhibit a unique characteristic of being resistant to the killing effect of ionizing radiation. A three- to eightfold elevation in expression of c-
myc
and an apparent activation of c-
raf
-1 gene have been observed in these noncancerous skin fibroblasts. These results may provide insight into the heritable defect underlying the familial predisposition to a variety of cancers.
Neuronal Supersensitivity to Acetylcholine Induced by Kindling in the Rat Hippocampus
Authors: Burchfiel James L. , Duchowny Michael S. , Duffy Frank H.
Published: October 2006

Kindling is an experimental model of epilepsy in which periodic brain stimulation induces the progressive development of electrical and behavioral seizures. A kindling-induced electrical seizure (afterdischarge) in the rat hippocampus produces prolonged neuronal supersensitivity to microiontophoretically applied acetylcholine after a latency of 40 to 60 minutes. Neuronal acetylcholine supersensitivity is correlated with the further progression of kindling. A larger hippocampal afterdischarge is elicited by a subsequent kindling stimulus delivered in the presence of acetylcholine supersensitivity, but not by one delivered before the onset of the supersensitivity. The results suggest that alteration of synaptic sensitivity to acetylcholine may contribute to kindling and epileptogenesis.
Nerve Terminal Remodeling Visualized in Living Mice by Repeated Examination of the Same Neuron
Authors: Purves Dale , Voyvodic James T. , Magrassi Lorenzo , Yawo Hiromu
Published: October 2006

The distribution of presynaptic endings on the surfaces of autonomic ganglion cells was mapped in living mice after intravenous administration of a styryl pyridinium dye. The staining and imaging techniques did not appear to damage the ganglion cells, or the synapses on them; these procedures could therefore be repeated after an arbitrary period. Observations of the same neurons at intervals of up to 3 weeks indicate that the pattern of preganglionic terminals on many of these nerve cells gradually changes.
Shape Analysis of the Histone Octamer in Solution
Authors: Uberbacher Edward C. , Harp Joel M. , Wilkinson-Singley Elizabeth , Bunick Gerard J.
Published: October 2006

The conformation of the histone octamer is shown to depend upon the specific salt used to solubilize it. In 2
M
sodium chloride the octamer is similar in size and shape to the histone component of crystallized core nucleosomes. In contrast, in 3.5
M
ammonium sulfate the octamer is elongated, resembling an ellipsoid with approximate dimensions of 114 by 62 by 62 angstroms. These results indicate that the elongated conformation seen in the 3.3 angstroms electron density map of the histone octamer crystallized in ammonium sulfate is due to the particular salt conditions used.
Time-Resolved X-Ray Diffraction Studies of the B⇆D Structural Transition in the DNA Double Helix
Authors: Mahendrasingam A. , Forsyth V. T. , Hussain R. , Greenall R. J. , Pigram W. J. , Fuller W.
Published: October 2006

Because of the relation between topology and function, there has been much interest in the structural transitions of the various conformations of DNA polymers. The x-ray fiber diffraction analysis system at the Daresbury Synchrotron Radiation Source was used to study the reversible transition between the B and D forms of the synthetic DNA poly[d(A-T)] ⋅ poly[d(A-T)]. The gradual progression of conformations between these two forms indicates that the DNA double helix does not undergo a change of handedness during this transition.
A Mouse Homeo Box Gene Is Expressed in Spermatocytes and Embryos
Authors: Rubin Michael R. , Toth Leslie E. , Patel Mayuri D. , D'Eustachio Peter , Nguyen-Huu M. Chi
Published: October 2006

The MH-3 gene, which contains a homeo box that is expressed specifically in the adult testis, was identified and mapped to mouse chromosome 6. By means of in situ hybridization with adult testis sections and Northern blot hybridization with testis RNA from prepuberal mice and from
Sl
/
Sl
d
mutant mice, it was demonstrated that this gene is expressed in male germ cells during late meiosis. In the embryo, MH-3 transcripts were present at day 11.5 post coitum, a stage in mouse development when gonadal differentiation has not yet occurred. The MH-3 gene may have functions in spermatogenesis and embryogenesis.
"Spontaneous" Neoplastic Transformation in Vitro: a Form of Foreign Body (Smooth Surface) Tumorigenesis
Authors: Boone Charles W. , Takeichi Noritoshi , Eaton Sol del Ande , Paranjpe Meera
Published: October 2006

Explants of subcutaneous connective tissue from adult BALB/c mice into plastic petri dishes were serially subcultured and tested for tumorigenicity in two ways: by the subcutaneous implantation of cells attached to plastic plates (1 by 5 by 10 millimeters), and by the subcutaneous injection of cells suspended in saline. Cells grown in vitro for 18 or more days before being implanted attached to a plastic plate (2.4 x 10
4
to 3.4 × 10
5
cells per plate) formed tumors after 24 to 79 weeks. The latent period before tumor appearance correlated inversely with the time spent by the cells in tissue culture. Cells inoculated in saline suspension (10 to 100 times the above number per plate) did not form tumors until after 84 days in vitro; plates alone did not induce tumor formation within more than 1 1/2 years of implantation. The tumors arising from the plate-attached cells were transplantable without plates and histologically appeared to be undifferentiated sarcomas. It is well established that smooth-surfaced foreign bodies, regardless of their chemical composition, will produce sarcomas when transplanted subcutaneously in rodents. We interpret our data, particularly the decrease in tumor latent period with time spent in tissue culture, as indicating that a smooth surface was acting as a carcinogen first in vitro (the surface of the tissue culture dish) and then in vivo (the surface of the plastic plate).
Amitotic Neuroblastoma Cells Used for Neural Implants in Monkeys
Authors: Gash D. M. , Notter M. F. D. , Okawara S. H. , Kraus A. L. , Joynt R. J.
Published: October 2006

The potential utility of cultured neuroblastoma cells as donor tissue for neural implants into the mammalian brain has been examined. Cells from a human neuroblastoma cell line, IMR-32, were labeled with [
3
H]thymidine and chemically rendered amitotic. These differentiated IMR-32 cells were grafted into the hippocampi of five adult African Green monkeys, and graft survival was evaluated for up to 270 days after transplantation. Autoradiographically labeled grafted cells were identified in four animals. Processes from grafted cells could be followed for distances of up to 150 micrometers into the host brain. No evidence for neoplastic growth of the transplant was found. Thus, grafted neuroblastoma cells can survive for prolonged periods in the primate brain and may serve as a practical source of donor tissue for neural implants.
Cytosolic Acidification as an Early Transductory Signal of Human Neutrophil Chemotaxis
Authors: Yuli Itzhak , Oplatka Avraham
Published: October 2006

The inflammatory reaction of human neutrophils consists of two successive phases. In the first, designated chemotaxis, the cells home in on a foreign intruder. In the second, the cells attempt to eliminate the intruder by secreting lysosomal enzymes and superoxide anions. The initiation of chemotaxis involves prompt morphological changes that are manifested by a sharp biphasic drop in light scattering, accompanied by a transient cytosolic acidification. In a search for a causal relation between these two events, the neutrophil cytoplasm was abruptly acidified by the application of sodium propionate. This evoked a pulse of decreasing light-scattering, the time course and amplitude of which were practically identical to the rapid response induced by chemoattractants such as
N
-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP). Both fMLP- and sodium propionate-induced responses were unaffected by amiloride, but were inhibited with a similar dose-dependence by a series of proton uncouplers. The initial phase of the cytosolic acidification seems, therefore, to fulfill the criteria for a second messenger for the initiation of chemotaxis.
Human Neuroelectric Patterns Predict Performance Accuracy
Authors: Gevins Alan S. , Morgan Nelson H. , Bressler Steven L. , Cutillo Brian A. , White Roseann M. , Illes Judy , Greer Douglas S. , Doyle Joseph C. , Zeitlin Gerald M.
Published: October 2006

In seven right-handed adults, the brain electrical patterns before accurate performance differed from the patterns before inaccurate performance. Activity overlying the left frontal cortex and the motor and parietal cortices contralateral to the performing hand preceded accurate left- or right-hand performance. Additional strong activity overlying midline motor and premotor cortices preceded left-hand performance. These measurements suggest that brief, spatially distributed neural activity patterns, or "preparatory sets," in distinct cognitive, somesthetic-motor, and integrative motor areas of the human brain may be essential precursors of accurate visuomotor performance.
Physiological Effects of Transforming Growth Factor in the Newborn Mouse
Authors: Tam James P.
Published: October 2006

Transforming growth factor-type α accelerated incisor eruption and eyelid opening in the newborn mouse and also retarded the growth rates of hair and body weight when administered in high dosage (0.7 to 4 micrograms per gram of body weight). The results of whole animal studies indicate that transforming growth factor-type α and epidermal growth factor do not differ significantly in these effects and suggest that transforming growth factor-type α may be important in immature animals.
Chromosome-Sized DNA Molecules of
Plasmodium falciparum
Authors: Van der Ploeg Lex H. T. , Smits Mari , Ponnudurai Thivi , Vermeulen Arno , Meuwissen Joep H. E. Th. , Langsley Gordon
Published: October 2006

At least seven chromosome-sized DNA molecules (750 to 2000 kilobases in length and one fraction of undetermined molecular weight) from cultured clones and isolates of
Plasmodium falciparum
have been separated by pulsed-field gradient gel electrophoresis. Whereas asexual blood stages and sexual stages of the same line have identical molecular karyotypes, the length of chromosome-sized DNA molecules among different geographical isolates and several clones derived from a single patient is different. These length alterations of chromosomes are the result of DNA rearrangements that must occur unrelated to sexual differentiation.
The Insulin Receptor Contains a Calmodulin-Binding Domain
Authors: Graves C. Bruce , Goewert Robert R. , McDonald Jay M.
Published: October 2006

Substantial evidence suggests that calcium has a pivotal role in regulating the initial events through which insulin alters plasma membrane metabolism. Because binding of insulin to its receptor represents the initial site of insulin action in the plasma membrane, studies were undertaken to determine whether the insulin receptor is a calmodulin-binding protein. Preparations enriched in the insulin receptor and calmodulin-binding proteins were isolated from detergent-solubilized rat adipocyte membranes by chromatography with wheat germ agglutinin agarose and calmodulin-conjugated Sepharose, respectively. Substantial purification of a manganese-dependent, insulin-sensitive phosphoprotein of 95K identified as the β subunit of the insulin receptor was accomplished. Binding and photocovalent cross-linking of iodine-125-labeled calmodulin to these affinity-purified preparations and to isolated plasma membranes, followed by immunoadsorption with insulin receptor antibodies bound to protein A Sepharose, resulted in significant purification of a binding complex of 110K to 140K. These results indicate that the adipocyte insulin receptor or a polypeptide closely associated with the receptor is a calmodulin-binding protein.
Human Immunoglobulin D: Genomic Sequence of the Delta Heavy Chain
Authors: White Marga Belle , Shen Anna L. , Word Charlotte J. , Tucker Philip W. , Blattner Frederick R.
Published: October 2006

The DNA coding for the human immunoglobulin D(IgD) heavy chain (δ, delta) has been sequenced including the membrane and secreted termini. Human δ, like that of the mouse, has a separate exon for the carboxyl terminus of the secreted form. This feature of human and mouse IgD distinguishes it from all other immunoglobulins regardless of species or class. The human gene is different from that of the mouse; it has three, rather than two, constant region domains; and its lengthy hinge is encoded by two exons rather than one. Except for the third constant region, the human and mouse genes are only distantly related.
Heterologous Protein Secretion from Yeast
Authors: Smith Robert A. , Duncan Margaret J. , Moir Donald T.
Published: October 2006

Secretion of calf prochymosin from yeast yields fully activable zymogen while production in the yeast cytoplasm yields insoluble, unactivable enzyme with aberrant disulfide bonding. Factors that increase the efficiency of secretion of prochymosin from yeast are use of a yeast secretion signal sequence, integration of the transcriptional unit into the yeast genome, and specific mutations in a number of host cell genes. In combination, these factors increase the secretion of calf prochymosin from less than 1 percent to more than 80 percent of the amount produced. Host mutations that increase prochymosin secretion also increase bovine growth hormone secretion more than 15-fold. These discoveries may be generally useful for production of many secreted mammalian proteins made inside microorganisms as insoluble aggregates.
All Members of the MHC Multigene Family Respond to Thyroid Hormone in a Highly Tissue-Specific Manner
Authors: Izumo Seigo , Nadal-Ginard Bernardo , Mahdavi Vijak
Published: October 2006

In mammals different isoforms of myosin heavy chain are encoded by the members of a multigene family. The expression of each gene of this family is regulated in a tissue- and developmental stage-specific manner as well as by hormonal and various pathological stimuli. In this study the molecular basis of isoform switches induced in myosin heavy chain by thyroid hormone was investigated. The expression of the myosin heavy chain gene family was analyzed in seven different muscles of adult rats subjected to hypo- or hyperthyroidism with complementary DNA probes specific for six different myosin heavy chain genes. The results demonstrate that all six genes are responsive to thyroid hormone. More interestingly, the same myosin heavy chain gene can be regulated by thyroid hormone in highly different modes, even in opposite directions, depending on the tissue in which it is expressed. Furthermore, the skeletal embryonic and neonatal myosin heavy chain genes, so far considered specific to these two developmental stages, can be reinduced by hypothyroidism in specific adult muscles.
Evidence for an Antiaphrodisiac in the Sweat Bee
Lasioglossum
(Dialictus)
Zephyrum
Authors: Kukuk Penelope
Published: October 2006

Male
Lasioglossum
(Dialictus)
zephyrum
in the field are attracted to models impregnated with the odor of virgin females. The number of males responding increases with increasing odor concentration. Once a male has contacted a model, its attractiveness to other males is reduced, suggesting that the male may contribute an antiaphrodisiac cue so that other males avoid mated females.
Hormonal Control of the Anatomical Specificity of Motoneuron-to-Muscle Innervation in Rats
Authors: Breedlove S. Marc
Published: October 2006

Motoneurons of the spinal nucleus of the bulbocavernosus innervate bulbocavernosus muscles in male rats. Adult female rats normally lack both the spinal nucleus and its target muscles. Prenatal treatment of females with testosterone propionate resulted in adults having, like males, both the spinal nucleus and its target muscles. However, prenatal treatment with dihydrotestosterone propionate preserves the muscles but not the motoneurons. This paradoxical condition might result from (i) bulbocavernosus muscles without innervation; (ii) muscles innervated by morphologically unrecognizable motoneurons; (iii) muscles innervated by a very few spinal nucleus cells, each innervating many bulbocavernosus fibers; or (iv) muscles innervated by motoneurons outside their normal anatomical locus in the spinal nucleus. The results of retrograde marker injections into the bulbocavernosus muscles of females treated with androgen refute the first three possibilities and confirm the last: the different androgen treatments result in anatomically distinct spinal motor nuclei innervating bulbocavernosus muscles.
Evolution in Inbred Strains of Mice Appears Rapid
Authors: Fitch Walter M. , Atchley William R.
Published: October 2006

Genetic variation at 97 loci in ten commonly used inbred strains of mice is greatly in excess of that expected under current assumptions. Evidence against all of the readily apparent explanations is presented and the possibility of early selection for heterozygosity or of conversion is suggested. The common ancestor of these strains is estimated to have occurred about 150 years ago.
Responsiveness and Receptive Field Size of Carp Horizontal Cells Are Reduced by Prolonged Darkness and Dopamine
Authors: Mangel Stuart C. , Dowling John E.
Published: October 2006

In the fish retina the interplexiform cells contain dopamine and provide a centrifugal pathway from the inner plexiform layer to horizontal cells of the outer plexiform layer. Dopamine application reduced the responsiveness and receptive field size of cone horizontal cells, as did a prolonged period of complete darkness. Other results suggest that the interplexiform cells may release dopamine after a prolonged period in the dark. The interplexiform-horizontal cell system may modify the strength of the antagonistic surrounds of retinal neurons as a function of time in the dark.
Visual Sensitivity: Significant Within-Species Variations in a Nonhuman Primate
Authors: Jacobs Gerald H.
Published: October 2006

Among squirrel monkeys (
Saimiri sciureus
) there are significant sex-related differences in visual sensitivity. As measured behaviorally in an increment-threshold task, a sample of males was found to be substantially less sensitive to long-wavelength (640-nanometer) light than a group of females tested in the same way, although the two groups showed no significant differences in sensitivity to a middle-wavelength (540-nanometer) light. The two groups also differed on a test designed to measure the effects of chromatic adaptation.
Purine Nucleoside Phosphorylase Deficiency: Altered Kinetic Properties of a Mutant Enzyme
Authors: Fox Irving H. , Andres Catherine M. , Gelfand Erwin W. , Biggar Douglas
Published: October 2006

Erythrocyte purine nucleoside phosphorylase from two brothers had 0.5 percent of normal activity. It differed from the normal enzyme by a tenfold increase in the Michaelis constant for inosine, an inability of inosine to protect against thermal lability, and a more positive net charge. The altered kinetic properties may account for the milder disease in the patients compared to the previously described cases. The data provide evidence for a structural gene mutation and genetic heterogeneity in the new disease of purine nucleoside phosphorylase deficiency and T cell dysfunction.
Retinoblastoma with 13q- Chromosomal Deletion Associated with Maternal Paracentric Inversion of 13q
Authors: Sparkes Robert S. , Muller Helga , Klisak Ivana , Abram Joseph A.
Published: October 2006

A girl with sporadic unilateral retinoblastoma and mental retardation has an interstitial deletion in the long arm of chromosome 13. Her mother has a paracentric inversion of one chromosome 13; the deleted chromosome 13 in the daughter is derived from the mother's normal chromosome 13.
Rank Order of Sarcoma Susceptibility Among Mouse Strains Reverses with Low Concentrations of Carcinogen
Authors: Prehn Liisa M. , Lawler Ellen M.
Published: October 2006

Ten mouse strains in which aryl hydrocarbon hydroxylase can be induced, or F
1
hybrids of these strains, were ranked according to their sarcoma susceptibility when exposed to a high concentration (5 percent) of the chemical carcinogen 3-methylcholanthrene. This rank order was reversed when the concentration of 3-methylcholanthrene was reduced to 0.05 percent.
Anomalous Amide I Infrared Absorption of Purple Membrane
Authors: Rothschild Kenneth J. , Clark Noel A.
Published: October 2006

Infrared absorption of purple membrane reveals an amide I frequency that falls outside the range normally found for alpha helices. This may indicate along with x-ray diffraction the existence of bacteriorhodopsin alpha helices with unusual structure.
Iron Deficiency Prevents Liver Toxicity of 2,3,7,8-Tetrachlorodibenzo-
p
-Dioxin
Authors: Sweeny G. D. , Jones K. G. , Cole F. M. , Basford D. , Krestynski F.
Published: October 2006

The compound 2,3,7,8-tetrachlorodibenzo-
p
-dioxin (TCDD) causes hepatocellular damage and porphyria in C57B1/6J mice, among a wide range of toxic effects. We compared the effect of TCDD toxicity in iron-deficient mice with that in mice receiving a normal diet. Porphyria did not develop in the iron-deficient animals, and these animals were also protected from hepatocellular damage and certain other toxic effects of TCDD.
Combination Tones at Frequencies Greater Than the Primary Tones
Authors: Zurek P. M. , Sachs R. M.
Published: October 2006

The existence of audible combination tones at frequencies greater than the primary tones that generate them has long been problematic. With primary tones at frequencies f
1
and f
2
, combination tones at f
1
+ f
2
, 2f
2
- f
1
, and other frequencies can be demonstrated and measured by using a contralateral probe tone to establish a binaural interaction with a given combination tone. The estimated amplitudes of these higher-frequency combination tones are generally 20 to 40 decibels below the amplitude of the primary tones.
Chemotherapeutic Drugs Increase Killing of Tumor Cells by Antibody and Complement
Authors: Segerling Martin , Ohanian Sarkis H. , Borsos Tibor
Published: October 2006

When the ascitic forms of two antigenically distinct guinea pig hepatomas induced by diethylnitrosamine are treated in vitro with chemotherapeutic drugs, their sensitivity to killing by xenogeneic antibody plus guinea pig complement increases. The effect is dependent on drug dose, is reversible, and does not appear to be due to increased antigen expression or fixation of the early acting components of guinea pig complement.
Galactosemia: Alterations in Sulfate Metabolism Secondary to Galactose-1-Phosphate Uridyltransferase Deficiency
Authors: Tedesco T. A. , Miller K. L.
Published: October 2006

Cultures of nonmutant as well as galactokinase-deficient fibroblasts incorporate 20 percent more [
35
S]sulfate when galactose is substituted for glucose in the medium; galactose-1-phosphate uridyltransferase-deficient cells incorporate 65.5 percent less. In addition to incorporating less [
35
S]sulfate, the uridyltransferase-deficient cells showed significant accumulation of intracellular galactose-1-phosphate within 4 hours after galactose exposure. Under the same conditions, no difference in [
3
H]uridine incorporation was observed. This metabolic alteration, occurring in response to galactose exposure, may be related to the pathophysiology of classical galactosemia.
Imbalance in X-Chromosome Expression: Evidence for a Human X-Linked Gene Affecting Growth of Hemopoietic Cells
Authors: Luzzatto Lucio , Usanga Essien A. , Bienzle Ulrich , Esan G. Folayan J. , Fusuan Felix A.
Published: October 2006

In each of six family members who were heterozygous at the X-linked locus for glucose-6-phosphate dehydrogenase, only one or the other of the two alleles at that locus was almost exclusively expressed. The data are consistent with evidence that X-chromosome inactivation is a random process that may be followed by selection for one of the two resulting cell types on the basis of an unknown gene, which is located on the X chromosome and which can affect the rate of proliferation of hemopoietic cells in humans.
Shark Heart Mitochondria: Effects of External Osmolality on Respiration
Authors: Lewiston Norman , Newman Andrew , Robin Eugene , Holtzman David
Published: October 2006

Shark mitochondrial respiration was studied in media with osmolalities between 160 and 1500 milliosmoles. The respiratory control ratio, a marker for functional integrity of the isolated mitochondria, was maximal at 1000 milliosmoles and decreased during hypotonic or hypertonic exposure. Shark mitochondria function best at their native tonicity, a value that produces abnormal function in mammalian mitochondria.
Aspartate: Distinct Receptors on
Aplysia
Neurons
Authors: Yarowsky P. J. , Carpenter D. O.
Published: October 2006

Aplysia
neurons have specific aspartate receptors that are distinct from those to glutamate. In some cells, aspartate selectively increases the membrane permeability to chloride, giving rise to a hyperpolarization, while on other cells it increases the permeability to sodium, causing a depolarization. There are also specific receptors for L-glutamate which mediate sodium, chloride, or potassium conductance increases, and another class of receptors activated by both glutamate and aspartate.
Neuronal Chemotaxis: Chick Dorsal-Root Axons Turn Toward High Concentrations of Nerve Growth Factor
Authors: Gundersen R. W. , Barrett J. N.
Published: October 2006

Micropipettes containing 2 to 50 biological units of β nerve growth factor (NGF) were placed near growing axons of chick dorsal-root ganglion neurons in tissue culture. The axons turned and grew toward the NGF source within 21 minutes. This turning response to elevated concentrations of NGF appears to represent chemotactic guidance rather than a general enhancement of growth rate.
Central Projection of Optic Tract from Translocated Eyes in the Leopard Frog (
Rana pipiens
)
Authors: Constantine-Paton Martha , Caprianica Robert R.
Published: October 2006

In
Rana pipiens
embryos, eye anlagen were moved to the evacuated ear position, where they continued to differentiate and sent their optic nerve fibers into the hindbrain. Upon entering the medulla, the optic fibers turned caudally, penetrated the spinal cord, and traversed the dorsolateral white matter to the caudal end. We found this pattern of growth in every animal; the optic fibers did not enter the tecta. These results suggest the existence within the neural tube of a three-dimensional gradient system to which embryonic optic fibers are responsive and which may guide the normal development of the visual pathway.
Differential Fluorescent Staining of Human Chromosomes with Daunomycin and Adriamycin—The D-Bands
Authors: Lin C. C. , van de Sande J. H.
Published: October 2006

Human chromosome preparations were treated with a group of anthracycline antibiotics. Well-defined, orange-red fluorescent bands were observed on chromosomes after the slide was stained with daunomycin and adriamycin but not with nogalamycin. The characteristic differential bands appeared to be similar to the banding patterns obtained by the quinacrine techniques. Interaction of these antibiotics with DNA could provide information on the general mechanism of fluorescent banding. Further, these bands (D-bands) appeared to be more stable than the Q-bands and may have some usefulness for routine clinical cytogenetic analysis.
Lens Cataract Formation and Reversible Alteration in Crystallin Synthesis in Cultured Lenses
Authors: Piatigorsky Joram , Shinohara Toshimichi
Published: October 2006

Embryonic chick lenses developed cortical cataracts and altered their pattern of δ-crystallin synthesis within 3 hours, if cultured without their vitreous body or traumatized with their vitreous body attached. δ-Crystallin reverted to the normal pattern by 24 hours in the cataractous lenses. Thus, biochemical differences that are only observable during the initial stages of cataractogenesis can exist between opaque and normal lenses.
A Serum Protein Associated with Chromatin of Cultured Fibroblasts
Authors: Aardi Luciano , Siri Annalisa , Santi Leonardo
Published: October 2006

Antibodies to chromatin proteins from human and mouse fibroblasts which have been cultured for more than 25 generations with heterologous serum show specificity for a homologous α-serum protein. These results indicate that among the chromatin-associated proteins there is one (or more) which has extensive structural similarity to a serum protein. This is the first direct evidence that a serumlike protein or proteins could be chromatin associated in vivo, as has been suggested by experiments showing in vitro interaction between DNA and certain serum proteins.
Cholecystokinin Inhibits Tail Pinch-Induced Eating in Rats
Authors: Nemeroff Charles B. , Osbahr Albert J. , Bissette Garth , Jahnke Gloria , Lipton Morris A. , Prange Arthur J.
Published: October 2006

Peripheral administration of the COOH-terminal octapeptide of cholecystokinin in doses from 1 to 100 micrograms per kilogram of body weight (0.25 to 25.0 micrograms per rat) significantly antagonized tail pinch-induced eating in rats, an animal model for stress-induced human hyperphagia. Centrally administered cholecystokinin was effective only in high doses (3 micrograms into the cerebral ventricle). The finding that the minimal effective dose of cholecystokinin in suppressing stress-induced appetitive behavior is smaller after peripheral than central administration suggests that the peptide is acting on peripheral, as opposed to central nervous system, substrates.
Induction of
Zugunruhe
by Photostimulation of Encephalic Receptors in White-Crowned Sparrows
Authors: Yokoyama Katsuhiko , Farner Donald S.
Published: October 2006

Daily 20-hour encephalic photophases (DEPP), transmitted (hours 0 to 20) via chronically implanted light-conducting fibers to selected sites in the basal hypothalamus of male white-crowned sparrows, were superimposed on daily 8-hour (hours 0 to 8) external ambient photophases (DAPP). Initially the birds displayed motor activity only during the 8-hour DAPP. After a delay of at least 2 weeks, some of the birds became intensively active during hours 8 to 20. We postulate that this period of "nocturnal" activity is equivalent to the nocturnal
Zugunruhe
shown by caged individuals of many nocturnally migratory species subjected to long days; such activity is generally regarded as the expression of migratory behavior.
Human and Mouse Hypoxanthine-Guanine Phosphoribosyltransferase: Dimers and Tetramers
Authors: Johnson Gerald G. , Eisenberg Lorraine R. , Migeon Barbara R.
Published: October 2006

Human and mouse hypoxanthine-guanine phosphoribosyltransferase subunits combine to form an active heteropolymer. Dimers form the basic subunit structure of the enzymes, yet the dimers can readily associate to form tetramers. The equilibrium between dimers and tetramers is significantly influenced by the ionic strength of the enzyme solvent.
Modified Bases Characterized in Intact DNA by Mass-Analyzed Ion Kinetic Energy Spectrometry
Authors: Schoen A. E. , Cooks R. G. , Wiebers J. L.
Published: October 2006

Pyrolysis of DNA into a chemical ionization source yields protonated bases and other base-containing ions. Kinetic energy spectra allow the characterization of the bases 5-methylcytosine and 1-methyladenine from underivatized salmon sperm DNA. Isomeric bases are distinguishable with this technique.
Experimental Phenylketonuria: Replacement of Carboxyl Terminal Tyrosine by Phenylalanine in Infant Rat Brain Tubulin
Authors: Rodriguez Julio A. , Borisy Gary G.
Published: October 2006

In the brains of newborn rats, about half of the tubulin molecules are modified posttranslationally by the addition of an aromatic amino acid at the carboxyl terminus of the α chain. Of the added residues, 96 percent are tyrosine and 4 percent are phenylalanine. After induction of hyperphenylalaninemia, the proportion of tubulin molecules containing carboxyl terminal phenylalanine increases up to eightfold and the pool of tyrosine-containing molecules decreases by an equivalent amount.
Distinctive Termini Characterize Two Families of Human Endogenous Retroviral Sequences
Authors: Steele P. E. , Rabson A. B. , Bryan T. , Martin M. A.
Published: October 2006

Human DNA contains many copies of endogenous retroviral sequences. Characterization of molecular clones of these structures reveals the existence of two related families. One family consists of full-length (8.8 kilobases) proviral structures, with typical long terminal repeats (LTR's). The other family consists of structures which contain only 4.1 kilobases of gag-pol sequences, bounded by a tandem array of imperfect repeats 72 to 76 base pairs in length. Typical LTR sequences that exist as solitary elements in the genome were cloned and characterized.
Salivary Proline-Rich Protein Genes on Chromosome 8 of Mouse
Authors: Azen Edwin A. , Carlson Don M. , Clements Scott , Lalley Peter A. , Vanin Elio
Published: October 2006

Endonuclease restriction (Hind III) fragments of DNA from Chinese hamster × mouse somatic cell hybrids hybridized with proline-rich protein complementary DNA clones only when the DNA was isolated from cells containing mouse chromosome 8, or a fragment of chromosome 8. The evidence suggests that proline-rich protein genes are located at the proximal portion of chromosome 8 toward the centromere.
The Navy's Oceanographic Program
Authors: Clark Austin H.
Published: October 2006

No plan for broad cooperative work which has been proposed in recent years offers such possibilities of benefit to all as the Navy's plan for oceanographic work. No precedent is involved in its adoption, for in times of peace oceanographic studies heretofore have always been an important part of the Navy's duties.

With these closing words I commend the plan to you as most worthy of your consideration and support.
The Trend of Thought in Physics. II
Authors: Swann W. F. G.
Published: October 2006

In its fundamental aspects, practically the whole of modern physics is concerned with the discussion of the relations which exist between the motions of two sets of points in such a way as to establish a sort of one-one correspondence between the things which we do, and the behavior of one set of points on the one hand, and the things which we observe and the behavior of the other set of points on the other hand. We send a beam of electrons through an X-ray tube, and certain dark lines appear on photographic plates elsewhere, or electrons are emitted with certain velocities which we measure indirectly. As regards the electrons which are emitted into our apparatus, we can almost say that we observe them directly. As regards the blackening of the photographic plate, we are content if we can account for certain electronic emissions or motions to which we can attribute it. We do not, however, try to establish a direct relation between the original beam of electrons and the photographic plate or photoelectric cell, because we find that certain other apparatus was necessary for the experiment, a calcite grating and X-ray target, and so forth. These pieces of apparatus are replaced in the mind's eye by other sets of points grouped into atoms and molecules, in a manner characteristic of the substances in such a way that we may hope to be able to establish a relation between the first set of points, those in the target, those in the calcite and those in the final photographic plate or photoelectric cell. The whole problem is to discover how the points must be assigned and what function their mutual motions are of each other in order that the correlation may be satisfactorily made.