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J Auger

Publications and source records attributed to J Auger.

72 records · Page 4Linked to original sources
PubMed1982

[Autopreservation of semen prior to sterilizing treatment].

Among 511 subjects candidate to autopreservation of semen prior to sterilizing treatment, satisfactory preservation was possible in 40% of patients with Hodgkin's disease and 15% of patients with carcinoma of the testis. This difference in percentage is related to differences in alterations of semen before any treatment. The semen of 9% of the patients was used for insemination; 95% wished that preservation be continued. Spontaneous recovery is possible, notably in carcinoma of the testis. Despite the risk of psychological problems, autopreservation should be recommended in cases with moderate initial alterations of the semen.

Hodgkin Disease↗
PubMed1978

Actin may be present on the lymphocyte surface.

Lymphocytes were assessed for the presence of surface actin and myosin by lactoperoxidase-catalyzed iodination and indirect immunofluorescence using antisera against purified pig skeletal muscle actin and pig smooth muscle myosin. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis of 125I-labeled pig, mouse, and human B lymphocytes revealed an intense radioactive band of 43,000 molecular weight, whereas pig and mouse T lymphocytes gave a much less intense band. This band comigrated with actin, was nonglycosylated as judged by lack of binding to lentil lectin-Sepharose, was bound specifically by myosin fibers, and could be distinguished from a polypeptide of similar mobility derived from the major histocompatibility antigens. These results suggest that actin is present on the surface of B lymphocytes and, to a lesser extent, on T lymphocytes. Pig, mouse, and human Ig-bearing cells were stained by antiactin and antimyosin antisera, as judged by indirect immunofluorescence, whereas non-Ig-bearing cells were not stained. Antibody binding, however, was depleted by adsorbing the antisera with Ig-Sepharose. It was concluded that the immunofluorescence results are misleading and reflect the presence of antibodies that crossreact with Ig.

Actins↗
PubMed1977

Mechanism of lymphocyte activation: the binding of phytohemagglutinin to the lymphocyte surface.

The dynamics of phytohemagglutinin (PHA)-lymphocyte interaction was studied using 125I-labeled PHA (leucoagglutinin) and pig mesenteric lymph node lymphocytes that had been depleted of erythrocytes, dead cells, adherent cells and immunoglobulin-bearing cells. Evidence was obtained that PHA stimulated the majority of the lymphocytes to transform. Binding of PHA at 37 degrees C was fairly rapid (rate constant for association: 2.6 X 10(5) M-1 sec-1), saturable, reversible and specifically inhibited by N-acetylgalactosamine (Kdiss: 3 X 10(-4) M) and unlabeled PHA. A Scatchard plot was curvilinear and gave evidence for 3.6 X 10(5) binding sites per cell comprising 8.7% of high affinity sites (Kdiss: 3.7 X 10(-9) M) and 91.3% of lower affinity (Kdiss: 1.4 X 10(-7) M). About 20% of the sites were occupied under culture conditions giving maximal transformation. Alternative explanations for the curvilinear plot included negative cooperative interactions and/or increase in affinity through multivalent interaction. Negative cooperativity was supported by the demonstration that free PHA promoted the dissociation of bound PHA. Binding was not affected by metabolic inhibitors, and binding to purified lymphocyte plasma membrane resembled that to whole cells. These results suggested that PHA binding to whole lymphocytes was not grossly influenced by "capping", endocytosis and shedding.

Acetylgalactosamine↗
PubMed1975

Recognition at cell surfaces: phytohaemagglutinin-lymphocyte interaction.

Many aspects of cell behaviour are regulated by the interaction of extracellular ligands with specific receptors exposed on the cell surface. The receptors correspond to membrane proteins and expecially glycoproteins. A key event in regulation is the transmission across the surface membrane of the information resulting from receptor-ligand interaction. The activation of lymphocytes by Phaseolus vulgaris phytohaemagglutinin (PHA) provides a convenient experimental model for the study of the molecular basis of receptor-ligand interaction and the molecular consequences of interaction. The receptor mediating lymphocyte activation by PHA is probably a unique glycoprotein which is present to the extent of about 3 X 10(4) molecules/cell. The PHA-receptor complex solubilized in 1% sodium deoxycholate has a molecular size of about 3 X 10(5). The primary event in the activation process is probably an increase in the permeability of the surface membrane to Ca2+. This may be achieved by PHA cross-linking ('patching') the receptors to form a polar channel that permits an influx of Ca2+.

Animals↗
PubMedDate not supplied

Multiple-dose pharmacokinetics of the new H1-receptor antagonist tazifylline in healthy volunteers.

The multiple-dose pharmacokinetics of the new H1-receptor antagonist, tazifylline, were investigated in healthy volunteers. From single-dose data, tazifylline appeared to be rapidly absorbed (median tmax of 0.6 h) and eliminated (t1/2 = 1.0 +/- 0.2 h). However, plasma levels measured on days 3 and 8 of the multiple-dose regimen (10 mg b.i.d. for 8 days) indicated moderate accumulation. A two-compartment model best described multiple-dose data with a terminal half-life of 15.6 +/- 7.6 h consistent with twice-daily dosing of tazifylline.

Adult↗
PubMedDate not supplied

Human sperm mitochondrial function related to motility: a flow and image cytometric assessment.

Current evaluation of male fertility, routinely estimated by sperm count, motility, and morphology, provides only crude information about the fertility state of individuals. Both flow and image cytometry were applied to mitochondrial activity and sperm motility respectively. Sperm samples from fertile donors were concomitantly measured for Rhodamine 123 (Rh123) uptake (an estimation of mitochondrial activity), percentage of dead cells, and motility characteristics, such as percentage of motility, curvilinear velocity, and amplitude of lateral head displacement. These measurements were done under experimental conditions known to modulate sperm motility (temperature and time course survival in a capacitating medium). Bimodal distributions were found for Rh123 uptake. Flow cytometry-derived parameters were essentially time-dependent whereas motility characteristics were primarily temperature-dependent. Correlations were found between various flow cytometry-derived parameters and motility characteristics. Most of the correlations were obtained after a 24 h incubation in a capacitating medium. The most significant correlation in every experimental condition concerned the percentage of motile spermatozoa and the Rh123 uptakes. The drop in motility observed after a 24 h incubation was paralleled by a markedly lower drop in mitochondrial activity. The data suggest that these two complementary techniques represent an improvement in basic and/or clinical assessment of the functional spermatozoa status.

Flow Cytometry↗
PubMedDate not supplied

Surgical treatment of lumbosacral instability caused by discospondylitis in four dogs.

OBJECTIVE: To describe a surgical technique involving distraction and stabilization of the lumbo-sacral vertebral segment using an external skeletal fixator in dogs with lumbosacral instability caused by discospondylitis. STUDY DESIGN: Retrospective clinical study. ANIMALS: Four client-owned dogs. METHODS: Medical records of all dogs diagnosed with discospondylitis from 1994 to 1997 were identified and reviewed. Four dogs with lumbosacral discospondylitis requiring surgical treatment were then specifically studied. Surgical technique, clinical signs, preoperative diagnostic investigation, radiographic findings, and the results of short-term and long-term reevaluations were recorded. RESULTS: Twelve dogs with discospondylitis were identified, 4 of which had lumbosacral discospondylitis. These 4 dogs underwent surgical distraction and stabilization because they failed to respond to medical treatment. Three dogs received a cancellous bone graft between L7 and S1 and had rapid interbody fusion of this vertebral segment. The dog that did not receive a graft did not have interbody fusion at the time of fixator removal. This did not affect the final clinical outcome. Lumbosacral pain and neurological deficits present before surgery rapidly subsided after the procedure. All dogs received concurrent antibiotic treatment for a minimum of 4 weeks. All dogs were clinically normal at the time of fixator removal and all continued to do well during the follow-up period (8-48 months; mean, 27.5 months). CONCLUSION AND CLINICAL RELEVANCE: Lumbosacral discospondylitis may not respond well to conservative treatment because of the mobility of the affected space. Surgical treatment involving distraction and stabilization to obtain intervertebral fusion is very effective in treating lumbosacral instability caused by discospondylitis.

Animals↗
PubMedDate not supplied

Evaluation of flow cytometric methods to measure human sperm concentration.

Human sperm concentration is usually assessed using hemocytometry (HM). However, external and internal quality control schemes have shown that the accuracy of this method is low overall. Flow cytometry (FC) is a rapid, accurate, and reproducible technology for the quantification of various cell populations. We used 3 FC methods for human sperm counting from a 1:1 mixture of a diluted semen sample with a suspension of fluorospheres of known concentrations. The events that represented sperm cells were detected according to 1) gating on size and granularity (FCM1), 2) gating on DNA staining by propidium iodide (FCM2), and 3) a combination of FCM1 and FCM2 (FCM3). Sperm concentration was calculated from the ratio of detected events to fluorosphere counts and fluorosphere concentration. A pilot study undertaken by 12 technicians from different laboratories to compare FCM1 with HM showed a general agreement between both methods, despite wide variations in sperm concentration exhibited by HM due to the use of unoptimized procedures. A second experiment indicated that the overall variability in sperm concentration assessment by FCM1 was lower than that produced by HM when performed by 2 technicians using optimal procedures for 3 preparations of the same semen samples. The overall mean coefficients of variation were 3.9% for FCM1 vs 8.0% for technician 1, 12.3% for technician 2 (P < .05), and 15.7% for both technicians (P < .05). FCM1, FCM2, and FCM3 were compared with HM performed by a single trained technician for 39 semen samples (triplicates) of various quality. Compared with HM, FCM1 and FCM2 overestimated the sperm concentration by 14% and 8%, respectively, against only 4% per million sperm for FCM3, which was effective for the full spectrum of sperm concentrations (except azoospermia). In conclusion, this study demonstrates that human sperm concentration can be accurately assessed by the FC method combining gating on cell size, granularity, and DNA staining.

Coloring Agents↗
PubMedDate not supplied

The nuclear status of human sperm cells by TEM image cytometry: nuclear shape and chromatin texture in semen samples from fertile and infertile men.

Changes in nuclear size, shape, and chromatin texture during spermiogenesis and epididymal transport of human sperm were recently analyzed using transmission electron microscopy (TEM) image cytometry followed by multivariate statistical analysis of data. In the present study, this same methodology was used to investigate the nuclear morphology of spermatozoa in semen samples from fertile and infertile men. Analysis was carried out on a large series of micrographs of sections of sperm nuclei from a donor group with proven fertility and from a patient group with a mean infertility duration of 10 years with no obvious male or female infertility factors (only a slight decrease in the proportion of sperm heads with normal morphology was noted in routine semen tests). For the patient group, it was found that nuclei had a significantly less flattened shape (i.e., increased roundness as a consequence of increased thickness and decreased length). Furthermore, significant differences between donor and patient groups were found for most parameters of chromatin texture. In the patient group, chromatin was less condensed, and there was more homogeneous distribution of the different degrees of chromatin condensation. In addition, the organization of chromatin condensation and distribution along the major axis of the nucleus was found to be significantly different in the two groups. Stepwise linear discriminant analysis indicated a good classification rate of only 66% for nuclei of patients when using the eight major nuclear parameters, thus indicating the striking heterogeneity of nuclear morphology for both patient and donor groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Nucleus↗
PubMedDate not supplied

[Evolution of male fertility in the last twenty years].

After the meta-analysis by Carlsen et al. (1992) showing a decline in human sperm count over the last 50 years, several studies have been made on the sperm characteristics of more or less homogeneous groups of men who were collecting semen in the same center for 10-20 years. A significant decline in sperm count was reported in some studies but not in others. The debate on declining sperm counts is not closed and these studies raised the following important questions: could the differences in results be the reflect of variation in techniques or blas in methodologies? If these phenomena are real, why a deterioration of semen quality in some places and not in others with so important geographical differences of sperm production? What are the possible consequences on human fertility and what are the causes? Unfortunately, there is presently no answer. The danish study provoked extensive discussion on the many possible sources of bias while there was less controversy concerning the studies carried out in a single center despite the extent of limitations of several of them. Recent publications indicated concomitant and increasing alterations of the development and/or function of the male genital tract, various observations in the wildlife and several experimental studies suggesting the possible deleterious role of numerous chemical compounds present in our environment. Therefore, prospective epidemiological studies and fundamental researchs are urgently needed.

Bias↗