Beta-endorphin/beta-lipotropin release and gonadotropin secretion after acute exercise in normal males

The plasma beta-endorphin (beta-EP) and beta-lipotropin (beta-LPH) response to acute exercise and the relationship of these opioid peptides to basal and luteinizing hormone-releasing hormone (LRH)-stimulated luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion was studied in eight normal male volunteers. Acute exercise resulted in a rise in plasma beta-LPH levels that returned to base line when measured 60 min after exercise. Plasma beta-EP levels did not demonstrate any rise when measured immediately after 20 min of exercise or at 60 min after exercise. Serum LH concentrations in individual volunteers declined to nadir values 60-180 min after exercise after which they showed a rebound to levels higher than the preexercise values in three of five volunteers in whom nadir LH levels were attained before the final (180 min) measurement. Serum FSH concentrations were unaltered by exercise. Acute exercise similarly did not alter the LH/FSH response to exogenous LRH stimulation. Pretreatment of the volunteers with the narcotic antagonist, naloxone, failed to alter the postexercise or LRH-stimulated LH and FSH release. The data suggest that beta-EP does not exert a suppressive effect on LH secretion after acute exercise in normal human males. Whether the suppression of LH secretion after acute exercise in unconditioned males is due to factor(s) cosecreted with beta-LPH, an increase in brain beta-EP or to alternate mechanisms such as alteration in central dopaminergic or GABAergic tone remains to be established.     

Differential interleukin 1 elaboration by unfractionated and density fractionated human alveolar macrophages and blood monocytes: relationship to cell maturity

The elaboration of interleukin 1 (IL 1) by mononuclear phagocytes is important in the regulation of human inflammatory and fibrotic reactions. Mononuclear phagocytes are morphologically and functionally heterogeneous cells. To further understand the processes controlling inflammation and fibrosis, in particular that in the human lung, we studied the elaboration of IL 1 by unfractionated and density-fractionated human alveolar macrophages and blood monocytes. Stimulated blood monocytes elaborated more IL 1 than stimulated alveolar macrophages. In addition, denser alveolar macrophages and blood monocytes elaborated more IL 1 than less dense alveolar macrophages and monocytes. Lastly, as monocytes matured in vitro, they lost their ability to elaborate IL 1 and became less dense. Thus, there is variability between and within mononuclear phagocyte cell populations in their ability to elaborate IL 1. These differences may result in part from differences in cell maturation.     

Mutations in Methanobacterium formicicum conferring resistance to anti-80S ribosome-targeted antibiotics

Summary Mutants of Methanobacterium formicicum resistant to the anti-80S ribosome-targeted inhibitor anisomycin were isolated and characterized. The resistance phenotype is correlated with a mutationally altered 50S ribosomal subunit. Anisomycin resistance in the mutants is accompanied by cross-resistance to other inhibitors of the 80S peptidyl-transferase centre like narciclasine, bruceantin, trichodermin and verrucarin A and by hypersensitivity to sparsomycin. This phenotype is identical to that reported for anisomycin-resistant mutants of yeast; it appears therefore, that the anisomycin interaction sites on the 70S ribosomes from M. formicicum bear the structural features typical of eukaryotic 80S organelles.     

Induction of oestrus in the camel (Camelus dromedarius) during seasonal anoestrus

Injection of 7000 i.u. PMSG induced oestrus in 7 camels during the last part of seasonal anoestrus. Mature follicles developed and a CL was formed after fertile mating. However, pregnancy was not maintained by Day 60 in the 3 females detected as pregnant by rectal palpation and increased progesterone concentrations at Day 50. A single male camel mated with 4 of the females 2-16 days after the PMSG injection, and 2 or 3 matings occurred. The failure of pregnancy after induction of oestrus and mating during seasonal anoestrus was probably due to inadequate luteal function.     

Lateral diffusion of an 80,000-dalton glycoprotein in the plasma membrane of murine fibroblasts: relationships to cell structure and function

The lateral diffusion of an 80,000-dalton major cell surface glycoprotein of murine fibroblasts has been measured. This antigen, identified through the use of monoclonal antibodies, is an integral glycoprotein distributed through the plasma membrane as judged by immunofluorescence and immunoelectron microscopy (see preceding paper). Measurements of fluorescence recovery after photobleaching were performed on the antigen-antibody complex within the plasma membrane of C3H/10T1/2 and NIH/3T3 cells after labeling the monoclonal antibody with fluorescein. Measurements were performed as a function of temperature, for interphase, mitotic, and G0 C3H/10T1/2 cells. The mean lateral diffusion coefficients (D) for the antibody-protein complex in interphase cells were in the range of 0.7-3.5 X 10(-10) cm2/s between 9 degrees and 37 degrees C, while that for the lipid analog probe, dihexadecylindocarbocyanine was about two orders of magnitude greater. This comparison indicates that peripheral interactions other than bilayer fluidity limit the lateral mobility of the antigen. The mobile fraction of mitotic, G0, and interphase cells showed a monotonic increase with temperature with most of the antibody-antigen complexes being free to move about 25 degrees C. Semi-quantitative interpretations of both the slow glycoprotein diffusion and the immobile fraction are offered. Comparison of diffusion coefficients for cells in different phases of the cell cycle does not reveal striking differences. Mobile fractions for G0 cells at 25 degrees C or less are substantially lower than in interphase cells. In all cases, there was a remarkably broad range of the fluorescence recovery data between different cells, resulting in up to a 10-fold variation in diffusion coefficients, which is far greater than the precision limits of the experiment. Diffusion values and mobile fractions were generally well within a factor of two when measured at several arbitrary points on a single cell. The origins of this cellular heterogenity remain to be elucidated. Lateral mobility in cell fragments and specific regions of single cells was also examined. The glycoprotein was mobile in ventral surface cell fragments. Its mobility was not altered in regions of cell- cell underlapping. However, the diffusion coefficient was threefold higher near the leading edge of motile cells compared to the trailing region. This difference may reflect weaker coupling of the glycoprotein to the underlying cytoskeleton in the dynamic leading edge region.     

Die endokrinen drüsen im embryo von Oncopeltus fasciatus Dallas (Insecta,Heteroptera)

The differentiation of the endocrine glands in the embryo of Oncopeltus fasciatus is described. The function of these glands can be correlated with the embryonic moults. The nuclei of some tissues already become polyploid in the embryo. It is discussed whether the endomitotic growth is dependent upon the function of the endocrine glands.

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Abkürzungen in den Abbildungen A Ca Anlage des Corpus allatum - A Cc Anlage des Corpus cardiacum - A Maxd Anlage der Maxillendrüse - A Meth Anhang des Mesothorax - A Mth Anhang des Metathorax - A Pl Anlage des-Pleuropodiums - A Prd Anlage der Prothoraxdriise - A Pth Anhang des Prothorax - A Spd Anlage der Speicheldrüse - Am Amnion - Ant Antenne - Ao Aorta - Blz Blutzelle - Ca Corpus allatum - Cc Corpus cardiacum - Cul Cuticulinschicht - Cut Cuticula - Des Desmosom - dl denselayer - Do Dotter - Ent Entoderm - Ep Epidermis - Epk Epidermiskern - Fk Fettkörper - fl Do verflüssigter Dotter - Hyp Hypocerebralganglion - Hz Herzschlauch - Kl Kopflappen - La Labrum - Lab Labium - M Mitteldarm mit verschiedenen Abschnitten (I, II, III und IV) - Mal Malpighisches GefäB - Max Maxille - Md Mandibel - Mes Mesoderm - Mik Mikrovilli - Ms Muskel - Mst Mittelstrang - Nbl Neuroblast - NZ Neurosekretorische Zellen - Oen Oenocyt - Oes Oesophagus - Ogl Oberschlundganglion - p Cut Procuticula - Pcz Pericardialzelle - Pi Pleuropodium - Prd Prothoraxdrüse - Pyl Pylorus - Re Rectum - Rk Riesenkern - S Schlüpfakt - Sal Salivarium - Ser Serosa - Sg Segmentgrenze - Spd Speicholdrüse (I = vorderer Lappen, II = scitlicher Lappen, III = hinterer Lappen, IV = akzessorische Drüse und V = Hylus) - Spdg Speicheldrüsengang - St Stechborste - Std Stinkdrüse - Sti Stigma - Stom Stomodaeum - Stt Stechborstentasche - tb E tubuläre Einstülpung des Prothorax - Ugl Unterschlundganglion - V Vakuole Mit Unterstutzung der Deutschen Forschüngsgemcinschaft.     

Collagen polysomes: Site of hydroxylation of proline residues

The biosynthesis of collagen on polysomes has been studied by using a newly devised method for obtaining polysomes in high yield from stationary-phase mouse fibroblast (line 3T6; Goldberg &, Green, 1967). These polysomes were completely disaggregated to monosomes by brief exposure to ribonuclease and they lost most of their radioactivity to the top of the sucrose gradients as a result of a 30-minute chase with unlabeled proline. After a ten-minute pulse with [³H]proline, nascent collagen peptides could be identified in these polysomes on sucrose gradients. Most of the proline residues susceptible to hydroxylation by collagen proline hydroxylase were found, in most cases, to be already hydroxylated in these nascent peptides. The nascent nature of these peptides was confirmed by the observation that treatment of the polysomes with RNase transferred the radioactive collagen peptides to the monosome area and these peptides could subsequently be removed to the soluble material at the top of the gradient upon treatment with puromycin. These findings therefore, show clearly that the hydroxylation of proline residues is occurring, in vivo under normal conditions, on nascent collagen chains. In no case was the degree of hydroxylation of the released collagen chains higher than that on the nascent collagen peptides. It seems likely, therefore, that the major site of proline hydroxylation is the nascent collagen peptide.     

IS SUICIDE PREVENTABLE?

Among 500 cases of suicide analyzed in Stockholm, fewer than a third were associated with depression. Most forms of psychiatric disease were represented. Nevertheless, most persons give some warning before attempting suicide, and these warnings should be the signal for preventive action. Centers with trained personnel could prevent many suicides, if the potential victims were recognized and referred early enough. Laymen too should be educated to recognize potential suicide and help avert it.