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Showing papers by "Rockefeller University published in 1975"


Journal ArticleDOI
03 Oct 1975-Science
TL;DR: Results indicate that the host-versus-graft reaction alone can enihance murine cvtomtiegalovirus in a chronicallY injected host atid maY help explain the high incidence of cvvtomegalov virus infection seen after renal and other allograft transplantation.
Abstract: C3H/He mice chronically infected with murine cYtomegalo virus were given skin allografis fromti histoincompatible BALB/c donors. A significant inicrease in cvtomegalovirus titers occurred within 3 days after placement oJ'the graft in the spleens and kidneYs oJ' the allograft recipients as compared with control aninmals. No significant changes in virus titers were detected in the salivary gland, lung, liver, or blood ofallograJi recipients. These results indicate that the host-versus-graft reaction alone can enihance murine cvtomtiegalovirus in a chronicallY injected host atid maY help explaini the high incidence ofcvvtomegalovirus infection seen after renal and other allograft transplantation

1,083 citations


Journal ArticleDOI
01 Dec 1975-Virology
TL;DR: The increase in infectivity caused by proteolytic cleavage of the HA polypeptide provides a biochemical explanation for the previously observed enhancement of plaquing efficiency of influenza viruses by the inclusion of pancreation or trypsin in the agar overlay.

593 citations


Journal ArticleDOI
TL;DR: The results are consistent with the view that the dexamethasone blockade of stress-induced ACTH release is mediated by the anterior pituitary, while the high specificity of cotricosterone binding in the hippocampus implies a specific but as yet undetermined effect of the hormone in this brain area, an effect which may not be directly related to regulation of ACTH secretion.
Abstract: In an attempt to relate binding of 3H-corticosterone and 3H-dexamethasone to their respective potencies in blocking pituitary-adrenal activity, cytosol binding in vitro and cell nuclear binding both in vivo and in tissue slices in vitro were studied in hippocampus, hypothalamus, and anterior pituitary of adrenalectomized rats. It was found that the extremely potent glucocorticoid dexamethasone has a different pattern of binding than corticosterone in the brain and in the anterior pituitary. 1) In cytosol, differences in the estimated binding capacities in a particular tissue for 3H-corticosterone and 3H-dexamethasone and different rates of inactivation in the ability to bind the two steroids are observed. 2) For 3H-corticosterone, cytosol binding in hippocampus is higher than that in hypothalamus, and cell nuclear binding follows the same pattern. For 3H-dexamethasone, cytosol binding is again higher in the hippocampus than in hypothalamus but cell nuclear binding in the two structures is not significantly different. With respect to the anterior pituitary, binding to cell nuclei is higher for 3H-dexamethasone, while the binding to cytosol macromolecules is higher for 3H-corticosterone. 3) In vivo and in vitro cell nuclear binding for both steroids showed the same pattern among the three tissues, but in vivo data showed more distinctly the preference of 3H-dexamethasone for the anterior pituitary and the preference of 3H-corticosterone for the hippocampus. 4) When labeled in tissue slices, cell nuclear radioactivity appears to be bound to macromolecules. 5) Steroid metabolism does not occur in slices during 60 min in vitro at 25 C and cannot account for the observed tissue differences in binding. The existence of more than one population of corticosteroid-binding sites in brain and in anterior pituitary is suggested. The results are consistent with the view that the dexamethasone blockade of stress-induced ACTH release is mediated by the anterior pituitary, while the high specificity of cotricosterone binding in the hippocampus implies a specific but as yet undetermined effect of the hormone in this brain area, an effect which may not be directly related to regulation of ACTH secretion.

456 citations


Journal ArticleDOI
01 Nov 1975-Cell
TL;DR: A technique is described for detecting fibrinolytic activity of single cells in culture of rat ovarian granulosa cells, indicating that this activity is plasminogen-dependent and correlated with ovulation by temporal and functional criteria.

432 citations


Journal ArticleDOI
10 Oct 1975-Science
TL;DR: The structural function of histones is to organize the long, fibrillar molecules of DNA into a more compact form, achieved, in part, by electrostatic interactions between the positively charged basic amino acids in the histone polypeptide chains and the negatively charged phosphate groups of DNA.
Abstract: deoxyribonucleic acid of the somatic cells of higher organisms occurs in association with small basic proteins called histones. In most cell types histones can be grouped into five major classes differing in size, positive charge, and amino acid composition. The primary structures of homologous histones from widely divergent species give evidence of remarkable evolutionary stability, particularly the arginine-rich histones, H3 and H4. Histones H2a and H2b (1) show slightly less evolutionary stability in their amino acid sequences, while histone H 1 varies to the greatest extent (la). The structural function of histones is to organize the long, fibrillar molecules of DNA into a more compact form. This organization is achieved, in part, by electrostatic interactions between the positively charged basic amino acid residues in the histone polypeptide chains and the negatively charged phosphate groups of DNA. Current evidence favors a cooperative interaction in which four of the five major types of histones interact with each other in specific ways and in stoichiometric proportions to form multimeric protein complexes (2). The fundamental unit of eukaryotic chromatin may be visualized as small nucleoprotein particles (3-5) [called nu bodies (4) or PS-particles (5)] along the DNA molecule, in which each histone complex is enveloped by the DNA strand (6). In the assembly of such particles and in their attachment to DNA, it is likely that particular regions of the histone polypeptide chains have different functions. Histone structures usually reveal a characteristic clustering of their basic amino acidsarginine, lysine, and histidine-thus generating regions of high positive charge (Fig. 1). This positively charged region is most

401 citations


Journal ArticleDOI
TL;DR: Compared with thos from other first degree relatives of out twins, a strong genetic component in the pathogenesis of SLE is suggested and the relative contribution of nongenetic and environmental factors to the expression of the disease is discussed.

351 citations


Journal ArticleDOI
TL;DR: In this paper, an explicitly soluble system of nonlinear differential equations related to certain Toda lattices was solved by applying a discrete version of the inverse scattering problem, and the solution of the finite system yielded also the solution to the finite Toda chain with two free ends, a problem that has been recently solved.

339 citations


Journal ArticleDOI
TL;DR: Changes in enzyme activities were found in those brain regions where gonadal hormones are known to affect sexual behavior and/or gonadotropin release and which contain putative hormone receptor sites after hormone treatment.

339 citations


Journal ArticleDOI
TL;DR: The enzymatic iodination technique has been utilized in a study of the externally disposed membrane proteins of the mouse L cell with no loss of cell viability under the conditions employed, less than 3% lipid labeling, and more than 90% of the labeled species identifiable as monoiodotyrosine.
Abstract: The enzymatic iodination technique has been utilized in a study of the externally disposed membrane proteins of the mouse L cell. Iodination of cells in suspension results in lactoperoxidase-specific iodide incorporation with no loss of cell viability under the conditions employed, less than 3% lipid labeling, and more than 90% of the labeled species identifiable as monoiodotyrosine. 90% of the incorporated label is localized to the cell surface by electron microscope autoradiography, with 5-10% in the centrosphere region and postulated to represent pinocytic vesicles. Sodium dodecylsulfate-polyacrylamide gels of solubilized L-cell proteins reveals five to six labeled peaks ranging from 50,000 to 200,000 daltons. Increased resolution by use of gradient slab gels reveals 15-20 radioactive bands. Over 60% of the label resides in approximately nine polypeptides of 80,000 to 150,000 daltons. Various controls indicate that the labeling pattern reflects endogenous membrane proteins, not serum components. The incorporated 125-I, cholesterol, and one plasma membrane enzyme marker, alkaline phosphodiesterase I, are purified in parallel when plasma membranes are isolated from intact, iodinated L cells. The labeled components present in a plasma membrane-rich fraction from iodinated cells are identical to those of the total cell, with a 10- to 20-fold enrichment in specific activity of each radioactive peak in the membrane.

330 citations


Journal ArticleDOI
TL;DR: The three-dimensional structure of the lectin concanavalin A has been determined at 2.0-A resolution by x-ray diffraction analysis and studies of the binding of beta-(o-iodophenyl)-D-glucopyranoside to Con A have indicated that the binding behavior of the protein is somewhat different in the two states.

327 citations



Journal ArticleDOI
TL;DR: Electrophysiological investigation of the pontine taste area proves that gustatory information from two distinct receptive fields may converge on the same central neuron.

Journal ArticleDOI
TL;DR: In this article, the role of perturbation theory in the symmetry breaking process is discussed, with a special emphasis on the Nambu-Goldstone realizations of chiral SU(2) × SU (2) and SU(3) + SU (3) ×SU (3).

Journal ArticleDOI
TL;DR: Investigation of the course of reticulospinal axons within the cervical gray matter indicated that a single axon may traverse wide areas of the ventral horn including regions on both sides of the spinal cord.
Abstract: Extracellular microelectrodes were used to record the activity of reticulospinal neurons within the medial ponto-medullary reticular formation in the cat. In one series of experiments reticulospinal neurons were activated from electrodes in the ventro-medial reticulospinal tract (RSTm) and in the ipsiand contralateral lateral reticulospinal tracts (RSTi, RSTC) at spinal levels C1–2, C4, Th1 and L1. RSTm neurons were found primarily in n.r. pontis caudalis and the rostro-dorsal part of n.r. gigantocellularis. 71% of these neurons projected as far as the lumbar spinal cord. RSTi neurons projecting to C4 and beyond were clustered in the caudo-ventral part of n.r. gigantocellularis, but those RSTi neurons projecting to the first three cervical segments were located more rostro-dorsally. In all, 63% of the RSTi neurons projected to the lumbar spinal cord. RSTc neurons, which comprised only 5% of the reticulospinal population, were found throughout n.r. gigantocellularis. RSTm neurons had a median conduction velocity of 101 m/sec whereas RSTi and RSTc had median conduction velocities on the order of 70 m/sec.

Journal ArticleDOI
TL;DR: The persistence of song after castration contrasts with the abolition of song by castration in other birds, and this may be related to the natural history of zebra finches.
Abstract: Castration of adult male zebra finches (Poephila guttata, Estrildidae) reduces their singing rate and the tempo of song, but castrates continue to sing song identical in form to preoperative song. Injection or implantation of testosterone propionate (TP) but not of vehicle alone reverses the changes produced by castration. Castration or partial castration also reduces the frequency of courtship, copulation, and aggression. Androgen (TP) replacement reverses these changes, but control injections do not. The persistence of song after castration contrasts with the abolition of song by castration in other birds, and this may be related to the natural history of zebra finches.

Book ChapterDOI
01 Jan 1975
TL;DR: Measles, canine distemper, and rinderpest viruses form a distinct subgroup on the basis of antigenicity, hemagglutinating characteristics, and lack of evidence for a virion-associated neuraminidase or neuraminic acid-containing cellular receptors, but it is now generally accepted that these viruses should be included in the paramyxovirus group because of their similar structural properties.
Abstract: The paramyxovirus group is a large one which includes the parainfluenza viruses types 1–5, Newcastle disease, and mumps viruses. Measles, canine distemper, and rinderpest viruses form a distinct subgroup on the basis of antigenicity, hemagglutinating characteristics, and lack of evidence for a virion-associated neuraminidase or neuraminic acid-containing cellular receptors. However, it is now generally accepted that these viruses should also be included in the paramyxovirus group because of their similar structural properties. Other more recently isolated viruses which have been classified as paramyxoviruses on the basis of morphological and biological properties are Yucaipa (Dinter et al., 1964) and Nariva (Walder, 1971) viruses. Table 1 lists paramyxoviruses and their primary hosts.

Journal ArticleDOI
01 Nov 1975-Cell
TL;DR: Evidence that plasmin decreases the tensile strength of follicle wall preparations is reported, and the potential for the involvement of these substances in ovulation is discussed.

Journal ArticleDOI
TL;DR: Autoradiographic techniques for light microscopic examination of sex steroid retention were applied to the brains of male and female Xenopus laevis, an anuran amphibian, after 3H‐estradiol administration and found the anterior preoptic area and the ventral infundibular nucleus contained the greatest number of labelled cells.
Abstract: Autoradiographic techniques for light microscopic examination of sex steroid retention were applied to the brains of male and female Xenopus laevis, an anuran amphibian, after 3H-estradiol administration. Estrogen was concentrated by cells in three telencephalic areas (the ventral striatum, the ventral-lateral septum and the amygdala), the anterior preoptic area, the ventral thalamus, the ventral infundibular nucleus, and in the torus semicircularis. The anterior preoptic area and the ventral infundibular nucleus contained the greatest number of labelled cells. The topography of estrogen-concentrating cells was the same in male and female brains. This fact and comparisons of 3H-estradiol with 3H-testosterone retention in Xenopus suggest that the sex steroid itself, and not the genetic sex of Xenopus determines the pattern of uptake by cells in the brain. The distribution of hormone-concentrating cells in Xenopus has many similarities to that found in birds and mammals. Preoptic, hypothalamic (tuberal), limbic forebrain and specific mesencephalic sites in all these forms contain labelled cells following radioactive sex steroid administration. Findings in Xenopus add to the argument for a phylogenetically stable system of hormone-concentrating nerve cells in limbic, hypothalamic and mesencephalic structures.

Journal ArticleDOI
TL;DR: Using an electrophoretic analysis of alloenzymes, populations of Nuttall's white-crowned sparrows in California and populations of the mountain white-Crown (Z. oriantha) in Colorado were investigated to determine if song dialects were correlated with genetic differentiation.
Abstract: Song dialects have been described in several bird species (Marler and Tamura, 1962; Lemon, 1966; Nottebohm, 1969). Clear examples are found in the resident white-crowned sparrows (Zonotrichia leucophrys nuttalli) of coastal California and in populations of the chingolo (Zonotrichia capensis) of Argentina. Where dialects occur in these species an area of breeding habitat is occupied by territorial males that with few exceptions sing a very similar song. Contiguous and allopatric with this area males of another population sing a different song type. It has been shown (Marler and Tamura, 1964; Marler, 1970) that in the white-crown (Z. 1. nuttalli) the dialect is learned during the first few weeks of life. The contiguity of the populations with discretely different vocalizations could be related to several interesting questions in population genetics, vocal communication, and evolutionary processes. On a general level, however, the dialect phenomenon leads to two central issues: (1) How do dialects arise? and (2) What role, if any, do they play in the biology of the birds? In this paper I provide a speculation on the first question and some data that may clarify the second. Following a suggestion by Marler and Tamura (1962), Nottebohm (1969) proposed that females might preferentially mate with males of their own dialect, thereby constraining a locally adapted gene pool. This hypothesis, that dialects reduce gene migration, came from the observation that Z. capensis on altitudinal gradients in Argentina exhibits a series of dialect populations possibly corresponding to different selective regimes, whereas a single dialect is found over vast areas of lowland pampas where selection may be spatially homogeneous (Nottebohm, 1969; Nottebohm and Selander, 1972). There, are other possible explanations of song dialects in birds. First, song dialects, a consequence of vocal learning, may play no important role. Perhaps during the early learning phase, young birds acquire population specific calls that promote flocking, foraging efficiency, predator avoidance, or individual recognition, that are important for winter survival. Thus, the selective advantage of vocal learning would be explained by winter ecological conditions and not territorial breeding behavior. Second, dialects could maximize outcrossing in small populations. Females would mate with males having a song type unlike that of their early experience. Third, dialects may be a result of intrasexual selection and bear no direct relationship to mate selection. Perhaps vocal convergence bestows some advantage in gaining and holding a territory but females do not use dialect information for mate choice. Using an electrophoretic analysis of alloenzymes, I investigated populations of Nuttall's white-crowned sparrow (Z. 1. nuttalli) in California and populations of the mountain white-crown (Z. 1. oriantha) in Colorado to determine if song dialects were correlated with genetic differentiation.


Journal ArticleDOI
TL;DR: Sera from patients with systemic lupus erythematosus (SLE), as detected by microcytotoxicity and indirect immunofluorescence, were predominantly cold reactive and of the IgM class, and the functional significance of these antilymphocyte antibodies is discussed.
Abstract: Antilymphocyte antibodies in serum from patients with systemic lupus erythematosus (SLE), as detected by microcytotoxicity and indirect immunofluorescence, were predominantly cold reactive and of the IgM class. These IgM antibodies were most active at 4 degrees C. IgG antibodies were infrequent, and were only minimally lymphocytotoxic. Most sera were cytotoxic for autologous lymphocytes and were equally reactive with normal and SLE lymphocytes, as well as with B- and T-cell preparations. Separate T- and B-cell specificities, which appeared not to be related to HL-A determinants, were identified by differential absorption experiments. The functional significance of these antilymphocyte antibodies is discussed.

Journal ArticleDOI
TL;DR: The amino acid sequence of the COOH-terminal CNBr fragment, F3 (residues 130 to 237), of concanavalin A has been established, completing the determination of the covalent structure of this lectin.

Journal ArticleDOI
TL;DR: It has been suggested that the learning processes which occur during the critical period for bird song development are dependent on adrogens, but castration of male zebra finches at ages 9-17 days did not prevent song development, and normal learning occurred after the time of castration.
Abstract: It has been suggested that the learning processes which occur during the critical period for bird song development are dependent on androgens. Castration of male zebra finches (Poephila guttata, Estrildidae) at ages 9–17 days did not prevent song development, and normal learning occurred after the time of castration. Thus the learning processes of song development occur in the absence of gonadal androgens. Castrates tended to develop song more slowly than normals, which is potentially attributable to a decreased rate of singing in the castrates, or to a direct effect of androgen on the learning processes.


Journal ArticleDOI
TL;DR: In this paper, phase transitions for the quantum field interaction λφ4+m02φ2,m02/λ≪1 were established in two dimensional space time.
Abstract: Phase transitions for the quantum field interaction λφ4+m02φ2,m02/λ≪1 are established in two dimensional space time.

Journal ArticleDOI
01 Dec 1975-Cell
TL;DR: Sera such as dog or monkey, which permit high levels of plasmin formation and activity, support cell growth in semi-solid media better than sera in which plasminiogen is activated poorly or that are plasmineogen-deficient; concomitantly, cables disappear in the former but not in the latter sera.

Journal ArticleDOI
TL;DR: In this paper, the phase behavior at low temperature, in particular the critical and tricritical properties, of liquid 3He4He mixtures and certain types of metamagnets, such as FeCl2 etc., is investigated.

Journal ArticleDOI
TL;DR: The results strongly suggest that amphetamine, in suppressing feeding behavior, acts through the lateral hypothalamus, perhaps the anterior region, causing a release of dopamine and norepinephrine from lateral hypothalamic nerve endings and a subsequent stimulation of dopaminergic and beta-adrenergic receptors located in that region.

Journal ArticleDOI
TL;DR: Lipoteichoic acid from several Gram-positive microorganisms, Forssman antigen (Fag) from Diplococcus pneumoniae R36A, and an acidic lipopolysaccharide (ALP) from Micrococcus luteus were examined for effects on four wall lysis systems, and LTAs failed to inhibit the amidase of pneumococcus.

Book ChapterDOI
TL;DR: This chapter explains allotypic phenomena adequately by involving regulator genes in the linkage, somatic recombination, and selective gene expression that have been observed in genetic studies employing allotypes.
Abstract: Publisher Summary This chapter presents the allotypic studies in the rabbit and offers more detailed information on several specific topics to which allotypic studies have contributed. The chapter focuses on the rabbit allotypes and gives an overview of the developments. There is a paucity of structural information on rabbit immunoglobulins and an optimal amount of genetic information has been obtained in studies on this species by the use of the immunoglobulin antigenic markers. The chapter explains allotypic phenomena adequately by involving regulator genes in the linkage, somatic recombination, and selective gene expression that have been observed in genetic studies employing allotypes. It is difficult to visualize these complex genetic relationships in terms of the repressors and corepressors that have been described for nonmammalian systems involving regulation. The possibility has been raised that rabbit immunoglobulin allotypes are not products of allelic structural genes, however are products of regulator genes. The studies on allotypes and idiotypes have made significant contributions to the knowledge of genetic control of immunoglobulin synthesis, knowledge that is, in many instances, relevant to more general biological topics.