Analysis of human V H gene repertoire expression in peripheral CD19+ B cells

Using CD19 B-cell selection and polymerase chain reaction-amplified cDNA libraries, we analyzed the peripheral immunoglobulin heavy chain variable repertoire of three healthy adult donors. Here we report that most of the CD19+ circulating B cells expressed unmutated V _H-D-J_H rearrangements. By specific V _H family hybridization, we show that V _H gene family utilization in the periphery roughly corresponds to the complexity of these families in the germline and appears to be relatively constant among the analyzed subjects. However, sequence data of clones picked at random from one IgM cDNA library reveals that in spite of this random utilization, the V _H gene expression in naive circulating B cells is highly biased towards the expression of a limited set of V _H genes. As previously reported by others, this restricted mechanism is also found for the D and J _H segments.The nucleotide sequence data reported in this paper have been submitted to the GenBank/EMBL nucleotide sequence database and have been assigned the accession numbers Z47213-Z47243 and Z47349     

Modeling of adaptations to physical training by using a recursive least squares algorithm

Busso, Thierry, Christian Denis, Régis Bonnefoy,André Geyssant, and Jean-René Lacour. Modeling ofadaptations to physical training by using a recursive least squaresalgorithm. J. Appl. Physiol. 82(5):1685-1693, 1997.The present study assesses the usefulnessof a systems model with time-varying parameters for describing theresponses of physical performance to training. Data for two subjectswho undertook a 14-wk training on a cycle ergometer were used to testthe proposed model, and the results were compared with a model withtime-invariant parameters. Two 4-wk periods of intensive training wereseparated by a 2-wk period of reduced training and followed by a 4-wkperiod of reduced training. The systems input ascribed to the trainingdoses was made up of interval exercises and computed in arbitraryunits. The systems output was evaluated one to five times per week byusing the endurance time at a constant workload. The time-invariantparameters were fitted from actual performances by using the leastsquares method. The time-varying parameters were fitted by using arecursive least squares algorithm. The coefficients of determinationr² were 0.875 and0.879 for the two subjects using the time-varying model, higher thanthe values of 0.682 and 0.666, respectively, obtained with thetime-invariant model. The variations over time in the model parametersresulting from the expected reduction in the residuals appearedgenerally to account for changes in responses to training. Such a modelwould be useful for investigating the underlying mechanisms ofadaptation and fatigue.

     

In vitro effects of glycolytic substrates and some nucleotides (ATP, ADP, AMP, cyclic AMP) on the motility of spermatozoids of human sperm, asthenospermic or normal

The effects of several drugs upon normal and asthenospermic human sperms were tested: cyclic AMP significantly and constantly increased the rate of motile spermatozoa in most samples having an initial motility rate between 20 and 60%. ATP kept up high the motility rate, particularly in sperm displaying the highest initial motility. Other drugs (glycolytic substrates, pyruvate, ADP, AMP, caffeine had inconstant effects upon a few sperms. None drug was efficient upon sperms with initial motility rate lower than 20%; this was probably due to important lesions of the locomotor apparatus of the spermatozoa, as shown by electron microscopy investigations.     

Somatostatin-containing fibers and neurophysin-containing fibers in the median eminence of the fox, as seen with a double staining cytoimmunoenzyme technique]

In the external layer of the median eminence of the fox, the somatostatin-containing fibers and neurophysin-containing fibers of the hypothalamo-infundibular tract are located in distinct areas. In the neural lobe, somatostatin-positive areas are simultaneously neurophysin-positive. Outside the SON and PVN, some somatostatin-positive and neurophysin-negative perikarya are scattered close to the third ventricle. These facts suggest the existence of two somatostatin systems: a hypothalamo-infundibular (neurophysin-negative) one and a hypothalamo-neurohypophyseal (neurophysin-positive) one.     

Immunocytological study of the gonadotrophic and thyrotrophic cells of the rat adenohypophysis]

On paraffin or semi-thin sections various anti-LH or anti-TSH sera stain indifferently all the thyrotrophs and the gonadotrophs. Inversely anti-beta-TSH, anti-beta-LH or anti-beta-FSH purified sera permit the discrimination of these two cell populations. The constancy of fixation of the anti-beta-LH and anti-beta-FSH sera on all the gonadotrophs gives evidence of their ability to produce both FSH and LH. However in a few female rats the central gonadotrophs are stained more weakly by anti-beta-FSH serum than by anti-beta-LH serum. The purification of the antisera by adjunction of hormonal antigens (alpha subunits or heterologous hormone) does not enable, with the PAP technique on thin sections, a selective staining of the secretory granules of the thyrotrophs or of the gonadotrophs.     

Immunocytological studies of C cells with anti-calcitonin or antisomatostatin immunoserums in rats treated with vitamin D, thyroxine or benzyl-thiouracil]

In rats treated with vitamin D3, thyroxin or BTU alone or with associations of vitamin D3 + BTU or vitamin D + thyroxin, immunocytochemical studies with an anti-human calcitonin serum show a stimulating effect of vitamin D and of thyroxin and an inhibiting effect of BTU on the C cells of the thyro?d. These results are in agreement with the existence of functional relations between follicular and C cells. A few calcitonin-containing cells are immunoreactive to an anti-somatostatin serum. All the C cells contain both calcitonin and somatostatin when they are grouped in a single big interfollicular cluster.     

The activity of one soluble component of the cell-free NADPH:O2 oxidoreductase of human neutrophils depends on guanosine 5'-O-(3-thio)triphosphate

Neutrophil NADPH:O2 oxidoreductase activity, essential in the killing of bacteria by neutrophils, can be elicited in a cell-free system that requires plasma membranes, cytosol and sodium dodecyl sulfate. In addition, GTP or its nonhydrolyzable analog guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) enhances NADPH oxidase activity. We investigated the mechanism of this effect of GTP gamma S in the cell-free system. Cytosol from human neutrophils was separated in three different soluble oxidase components (SOC I, SOC II, and SOC III). Previously we (Bolscher, B. G. J. M., Van Zwieten, R., Kramer, I. J. M., Weening, R. S., Verhoeven, A. J., and Roos, D. (1989) J. Clin. Invest. 83, 757-763) reported that the cytosol contains two components which act synergistically. We now report that one component (previously labeled SOC II) contains two different components that can be separated by ion exchange chromatography. Immunoblotting with antiserum B-1 (Volpp, B. D., Nauseef, W. M., and Clark, R. A. (1988) Science 242, 1295-1297), directed against a cytosolic complex capable of activating latent membranes in the cell-free system, showed a 47-kDa protein in SOC II and a 67-kDa protein in SOC III. SOC II also contains the 47-kDa phosphoprotein, which indicates that this phosphoprotein and the protein recognized by the antiserum are identical. Low rates of NADPH-dependent O2 consumption can be elicited by SOC II and SOC III in the absence of SOC I. This activity is independent of GTP gamma S. Addition of SOC I increases this activity 3-4-fold, only when GTP gamma S is present. Plasma membranes, incubated with SOC I plus GTP gamma S and re-isolated, showed a similar 3-4-fold enhanced O2 consumption with SOC II and SOC III. The GTP gamma S effect is exerted primarily at the level of the plasma membrane. The concentration of GTP gamma S that causes a half-maximal stimulation was 0.4 mu M. It is concluded that SOC I is a functional component of the NADPH oxidase.