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Biomedical subjects

H Lambert

Publications and source records attributed to H Lambert.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Opinion and attitude of physicians regarding organization and participation on a multidisciplinary alcoholism unit].

The inaccuracy of physicians in the diagnosis, evaluation and treatment referral of alcoholic patients has prompted us to set a Multidisciplinary Alcohol Unit (Unit). Its aims are to set coordinated and individualized treatment proposals and to train medical staff in dealing with alcohol problems. After six months of activity we performed an investigation by all physicians who delt with the Unit including residents and practitioners. We sent 78 questionnaires investigating training in alcohol problems, addictive diseases and psycho-social medicine, subjective usefulness of the Unit for the patient as well as for the medical staff, subjective effectiveness of treatments for alcoholics and reasons for patients' referral. 87% of the physicians completed the questionnaire. According to groups, 12 to 20% of the physicians reported that their training in addictive problems was sufficient. Half of practitioners and 20% of hospital residents reported that their training in psychosocial medicine was satisfactory. All the physicians who answered the questionnaire considered the Unit to be usefull for themselves, mainly because of the Unit's teaching abilities and 89% considered the Unit useful for the patients. In term of effectiveness, alcoholism treatment is percieved by residents to be more efficient when mediated by a specialized unit rather than by practitioners or by themselves. Practitioners percieved that the treatment is more efficient when handled by themselves or by a specialized social unit. Principal reasons to seek help from the Unit were a main diagnosis of alcohol-related disease, the need to complete the psycho-social evaluation and subjective insufficient skills in the field. In conclusion the Unit seems to meet the need of medical doctors despite the limited number of referred cases and is said to be usefull for their patients as well as for themselves.

Adult↗
PubMed1996

[Sudden death in patient with right bundle branch block and persistent ST segment elevation].

A 43 year old man was admitted to the hospital due to a syncopal episode and presented on the electrocardiogram a pattern of right bundle branch block (RBBB) associated with ST segment elevation from V1 to V4 and normal QT interval. Acute myocardial infarction was suspected but was not confirmed by laboratorial findings. Coronary arteriography was performed and revealed no obstructive disease. No sign suggesting structural heart disease was found. He remained asymptomatic but persisted with RBBB and ST segment elevation. He was discharged from the hospital and was referred to investigation for cardiac arrhythmia as an outpatient, but died suddenly two days later.

Adult↗
PubMed1995

Characterization of 45-kDa/54-kDa HSP27 kinase, a stress-sensitive kinase which may activate the phosphorylation-dependent protective function of mammalian 27-kDa heat-shock protein HSP27.

Heat-shock protein 27 (HSP27) is a major target of phosphorylation upon cell stimulation with a variety of agents and has been suggested to have a phosphorylation-regulated function at the level of actin filaments. Here we investigated comparatively the mechanisms of HSP27 phosphorylation by oxidative stresses, exposures to tumor necrosis factor (TNF), heat shock and growth factors. Extracts of Chinese hamster or human cells exposed to H2O2, xanthine/xanthine oxidase, menadione or TNF contained up to 15-fold more HSP27 kinase activity than comparable extracts obtained from control cells. Induction of HSP27 kinase activity by TNF or H2O2 was completely inhibited by first treating the cells with the antioxidant N-acetyl-L-cysteine, suggesting that generation of reactive oxygen metabolites was the key triggering element of this induction. In contrast, prior treatment with acetylcysteine had no or little effect on the induction by thrombin, serum and heat shock. The kinase activity in extracts of cells stimulated by heat shock, H2O2, sodium arsenite, TNF or growth factors was identified by in-gel renaturation and purified approximately 8000-fold by sequential chromatography. In all cases, the induced kinase activity was entirely associated with two polypeptides of 45 kDa and 54 kDa, identified as mitogen-activated-protein kinase-activated protein (MAPKAP) kinase-2 based on its reactivation in vitro by 42/44-kDa MAP kinases, its antigenic properties and its substrate specificity. The 45/54-kDa HSP27 kinase may play an important role in the cell response to oxidative stress. Overexpression of the wild-type HSP27 but not of a nonphosphorylatable form of human HSP27 in Chinese hamster cells conferred resistance to actin fragmentation by oxidative stress generated by H2O2. It is concluded that activation of the 45/54-kDa HSP27 kinase is a common mechanism of HSP27 phosphorylation to which converge both oxyradical-dependent and oxyradical-independent pathways and which may participate in a homeostatic response to stress at the level of actin microfilament.

Actin Cytoskeleton↗
PubMed1995

Modulation of cellular thermoresistance and actin filament stability accompanies phosphorylation-induced changes in the oligomeric structure of heat shock protein 27.

Phosphorylation of heat shock protein 27 (HSP27) can modulate actin filament dynamics in response to growth factors. During heat shock, HSP27 is phosphorylated at the same sites and by the same protein kinase as during mitogenic stimulation. This suggests that the same function of the protein may be activated during growth factor stimulation and the stress response. To determine the role of HSP27 phosphorylation in the heat shock response, several stable Chinese hamster cell lines that constitutively express various levels of the wild-type HSP27 (HU27 cells) or a nonphosphorylatable form of human HSP27 (HU27pm3 cells) were developed. In contrast to HU27 cells, which showed increased survival after heat shock, HU27pm3 cells showed only slightly enhanced survival. Evidence is presented that stabilization of microfilaments is a major target of the protective function of HSP27. In the HU27pm3 cells, the microfilaments were thermosensitized compared with those in the control cells, whereas wild-type HSP27 caused an increased stability of these structures in HU27 cells. HU27 but not HU27pm3 cells were highly resistant to cytochalasin D treatment compared with control cells. Moreover, in cells treated with cytochalasin D, wild-type HSP27 but not the phosphorylated form of HSP27 accelerated the reappearance of actin filaments. The mutations in human HSP27 had no effect on heat shock-induced change in solubility and cellular localization of the protein, indicating that phosphorylation was not involved in these processes. However, induction of HSP27 phosphorylation by stressing agents or mitogens caused a reduction in the multimeric size of the wild-type protein, an effect which was not observed with the mutant protein. We propose that early during stress, phosphorylation-induced conformational changes in the HSP27 oligomers regulate the activity of the protein at the level of microfilament dynamics, resulting in both enhanced stability and accelerated recovery of the filaments. The level of protection provided by HSP27 during heat shock may thus represent the contribution of better maintenance of actin filament integrity to overall cell survival.

Actin Cytoskeleton↗
PubMed1995

Food anaphylaxis following ingestion of carmine.

BACKGROUND: The risk of sensitization to reactive dyes is well established. The clinical situation is caused most often by synthetic azo dyes and triphenylmethane derivatives but natural dyes such as carmine extracted from dried female insects, Coccus cacti (cochineal), have been incriminated. OBJECTIVE: Study of a case of anaphylaxis after ingestion of yogurt to establish the responsibility of carmine. METHOD: Case report of a patient who received skin prick test and leukocyte histamine release test with carmine and yogurt. CONCLUSIONS: This case provided evidence of an IgE-dependent mechanism and draws attention to the triggering dose of carmine (1 mg) although the acceptable daily intake is up to 5.0 mg per kg of body weight.

Adult↗
PubMed1995

[Laparoscopic hernioplasty].

The laparoscopic hernioplasty is an operative technique with a biomechanical background. The thin-walled inguinal triangle of the abdominal wall is reinforced without tension. Regarding a few details this technique may repair groin hernia without recurrence and nearly uncomplicated.

Adolescent↗
PubMed1994

Detection of human leukocyte antigen class I messenger ribonucleic acid transcripts in human spermatozoa via reverse transcription-polymerase chain reaction.

OBJECTIVE: To determine by reverse transcription-polymerase chain reaction (PCR) whether human leukocyte antigen (HLA) class I messenger RNA (mRNA) is present in mature human spermatozoa. DESIGN: Mature human spermatozoa was isolated from donor semen using a swim-up technique. Total RNA was extracted via guanidinium isothiocyanate-cesium chloride ultracentrifugation. By the method previously validated in our laboratory, reverse transcription-PCR was performed using primers specific for HLA class I transcripts. Positive control cells included a choriocarcinoma cell line (JEG) and human fetal tissue. Transformed peripheral blood lymphocytes (PBL) were used as a negative control for somatic cellular contamination. RESULTS: Human spermatozoa were positive for HLA class I (-G and -B) mRNA by reverse transcription-PCR, consistent with the positive controls. We did not detect any mRNA for beta-actin, retinoblastoma (RB), CD4, or kappa light chain genes in the sperm complementary DNA samples, verifying that the class I mRNA detected was not due to somatic cellular contamination of the purified sperm samples. CONCLUSION: These experiments provide the first evidence that mRNA for HLA class I molecules are present in mature human spermatozoa. The physiological role of these transcripts is unknown at present. Further experiments characterizing the expression of HLA class I (-G and -B) mRNA in oocytes and preimplantation embryos are in progress.

Actins↗
PubMed1993

Heterogeneity of human sperm surface antigens identified by indirect immunoprecipitation of antisperm antibody bound to biotinylated sperm.

Target Ag recognized by clinically important C-fixing anti-sperm antibodies (ASA) were identified by indirect immunoprecipitation after incubation of biotinylated, motile sperm with ASA-positive sera from autoimmune, isoimmune, and vasectomized patients. This method assessed native protein thus permitting analysis of conformation-dependent membrane Ag that would be missed by previously reported Ag identification techniques. Sera from 35 ASA-positive and 10 ASA-negative patients were exposed to capacitated, surface-biotinylated motile sperm. After detergent-extraction of the membrane fraction, the immune complexes were precipitated with protein G-agarose. The Ag were eluted under reducing conditions, electrophoresed on SDS-10% PAGE, electroblotted onto nitrocellulose membranes, and visualized by the biotin/avidin-peroxidase detection method. By this method, only high titered ASA-positive sera demonstrated variable reactivity restricted to a total of eight to nine protein bands. Individual sera revealed a differential reactivity to a constant set of protein bands (63/61, 58/56, 29, and 21/19 kDa) and a preferential reactivity to either 45-, 43-, or 41-kDa protein Ag that were patient specific. None of these bands were precipitable by ASA-negative sera. ASA directed against the 63/61-kDa and 58/56-kDa polypeptides were found in 85% of immunoprecipitable sera; the 29-kDa was detectable with 70% of sera. Immunoreactivity to the 45-kDa to 41-kDa bands was detectable with 30% of the immunoprecipitable sera. Although the pattern of Ag recognized by ASA from autoimmune, isoimmune, and vasectomized patients was similar, our results indicate that in addition to the recognition of common human sperm surface determinants, distinct sperm surface epitopes are also recognized as foreign by the patient's immune system. Sera that immunoprecipitated the predominant monomeric 29-kDa or the dimeric 58/56-kDa Ag when preincubated with capacitated sperm markedly inhibited sperm binding and penetration to the human zona when compared with ASA-negative serum controls. It is suggested that C-fixing ASA directed to these surface determinants may account for some of the clinical manifestations of ASA-mediated infertility.

Acrosome↗
PubMed1993

[Absence of mitral valve prolapse during panic attacks induced by sodium lactate].

The recent identification of a new type of anxiety state, panic attack, has drawn attention to common pathways between panic disorder and cardiac somatization, particularly mitral valve collapse. A double-blind study was set up, using doppler-echocardiography during a panic attack induced by sodium lactate infusion. The results showed that there was no relationship between panic attack and mitral valve collapse, and that the lactate infusion-anxiety rate was only 35 percent.

Adolescent↗
PubMed1993

Transient activation of a distinct serine protein kinase is responsible for 27-kDa heat shock protein phosphorylation in mitogen-stimulated and heat-shocked cells.

We have investigated the phosphorylation of HSP27, a 27-kDa heat shock protein which is involved in cellular thermoresistance and is also an early target of phosphorylation during heat shock and cell stimulation by a variety of growth and differentiation factors. HSP27 is transiently phosphorylated after shifting Chinese hamster cells from their normal temperature of 37 to 44 degrees C. The phosphorylation correlated in time with the transient activation of specific HSP27 protein kinase activities. HSP27 kinase was also induced to maximal levels within 5-15 min following stimulation of quiescent cells with heat shock, serum, thrombin, or basic fibroblast growth factor. Extracts from quiescent cells stimulated by heat shock or serum were analyzed after sequential chromatography on cation exchange and hydroxylapatite columns. In both cases, a single and identical peak of HSP27 kinase activity was obtained, suggesting that the same protein kinase was induced. The HSP27 kinase efficiently phosphorylated recombinant Chinese hamster HSP27 or the synthetic peptide RALNRQLSSGV containing the major in vivo phosphorylation site of rodent HSP27. The kinase was inactive toward the ribosomal S6 protein, the peptide RALSSLRA from S6 protein, or the mutant HSP27 proteins with in vivo phosphorylation sites altered to glycine. The partially purified HSP27 kinase had no kinase C, kinase A, or S6 kinase activities; conversely, HSP27 was not a good substrate for these kinases. HSP27 kinase was rapidly inactivated in the presence of acid phosphatase, suggesting that its activity was regulated by phosphorylation. It is suggested that this heat shock- and serum-induced HSP27 kinase is a novel serine kinase which is linked to a major signal transduction cascade.

Acid Phosphatase↗
PubMed1993

New modalities under development for adhesion prevention: immunomodulatory agents and poloxamer barrier materials.

Obviously, no single modality will prove to be universally applicable or completely effective at preventing postoperative adhesion formation. Increasing understanding of the pathophysiology of peritoneal healing provides the intellectual basis for the development of specific interventions at critical points along the adhesion formation cascade. We believe that multimodality therapy, including the use of pharmacologic adjuvants such as immunomodulatory drugs and fibrinolytic/anticoagulant agents in conjunction with a barrier material tailored to the specific operative procedure may provide optimal results. Hopefully, developments in the 1990's will provide reproductive surgeons with the means to help patients derive maximal benefit from their reconstructive procedures.

Adjuvants, Immunologic↗