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Biomedical subjects

H Lambert

Publications and source records attributed to H Lambert.

At least 55 records · Page 3Linked to original sources

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↗

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↗

[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↗

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↗

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↗

[Efficacy of intravenous milrinone in the treatment of acute congestive cardiac failure. Results of a French multicenter study].

The hemodynamic effects and safety of milrinone, a phosphodiesterase inhibitor, were studied in 57 patients in the acute phase of cardiac failure. The drug was given intravenously as an initial push dose of 50 micrograms/kg in 10 min followed by a 24 hour infusion at the dose of 0.5 micrograms/kg/min. Maximal response was obtained after 15 min and persisted throughout the infusion. Cardiac index rose by 40%, while pulmonary capillary pressure fell from 25 mmHg to 17 mmHg (-30%) by the fifth minute of treatment. Mean pulmonary artery pressure fell by 20% by the 15th minute. Systemic resistance decreased by 26% and pulmonary vascular resistance by 22%. All these variations were significant. Heart rate and systemic blood pressure remained stable. Study of three sub-groups: digoxin vs non-digoxin, sinus rhythm vs atrial fibrillation, and coronary patients vs non-coronary patients, revealed no significant difference. Safety of the drug was good, no extra-cardiac actions having required interruption of the infusion. Stoppage was made necessary by two instances of ventricular tachycardia. Improved hemodynamic effects and the good safety/acceptability of the drug indicate that milrinone is a treatment of choice in cardiac failure.

Acute Disease↗

Human HSP27 is phosphorylated at serines 78 and 82 by heat shock and mitogen-activated kinases that recognize the same amino acid motif as S6 kinase II.

The intracellular concentration of the 27-kDa mammalian heat shock protein, HSP27, increases several-fold after heat and other metabolic stresses and is closely associated with the acquisition of thermotolerance. Posttranslational modifications may also affect the function of HSP27. Heat shock of HeLa cell cultures, or treatment with arsenite, phorbol ester, or tumor necrosis factor, caused a rapid phosphorylation of preexisting HSP27 and the appearance of three phosphorylated isoforms, HSP27 B, C, and D. Digestion with trypsin and fractionation of the peptides by reverse phase high performance liquid chromatography revealed three 32P-labeled phosphopeptides. Microsequence analysis identified peak I as Ala76-Leu77-Ser78-Arg79 and peak II as Gln80-Leu81-Ser82-Ser83-Gly84-Val85- Ser86-Glu87-Ile88-Arg89; peak III contained the undigested peptide pair Ala76-Arg89. Ser82 was the major site and Ser78 the minor site of phosphorylation. Mutant proteins with Ser78 or Ser82 altered to glycine or Ser78-Ser82 double mutants were phosphorylated to reduced extents in vivo after heat or arsenite treatment. Ser78 and Ser82 (and Ser15) occur in the sequence motif RXXS, which is recognized by ribosomal protein S6 kinase II. Mitogenic stimulation of serum-deprived, Go-arrested Chinese hamster cells with serum, thrombin, or fibroblast growth factor also stimulated phosphorylation of HSP27 Ser78 and Ser82, and mitogenic stimulation and heat shock activated protein kinase activities that phosphorylated HSP27 and protein S6 in vitro. These results suggest that HSP27 may exert phosphorylation-activated functions linked with growth signaling pathways in unstressed cells. A homeostatic function at this level could protect cells from adverse effects of signal transduction systems which may be activated inappropriately during stress.

Amino Acid Sequence↗

Transient non-cardiogenic pulmonary edema following massive ingestion of ethylene glycol butyl ether.

A case of acute poisoning with ethylene glycol butyl ether (EGBE) is reported in a chronic alcohol abuser. On admission the 53-year-old patient was comatose with metabolic acidosis, shock, and noncardiogenic pulmonary edema confirmed by haemodynamic study. Following supportive treatment and haemodialysis the outcome was favorable. The relationship between respiratory failure and EGBE is examined.

Alcoholism↗

The cultural logic of Indian medicine: prognosis and etiology in Rajasthani popular therapeutics.

This paper considers certain ways of describing and treating sickness in rural Rajasthan, and the representations of sickness and of the body on which they are based. Two indigenous medical or 'ethnomedical' perspectives on illness and its treatment emerge from the analysis of ethnographic material collected during field research in northern India. In the first part of the paper various characterizations of South Asian medicine are discussed, and I suggest that Western preconceptions about the nature and purpose of 'medicine' itself has led one of these perspectives to be highlighted in anthropological considerations at the expense of the other. A further dimension of ethnomedicine emerges through discussions of local therapeutic rituals and discourses about sickness and the body. This consideration of one domain of local therapeutics reveals its underlying cultural logic and highlights ethnomedical formulations that have heretofore been analytically neglected. It does not address the formal or textually based Indian medical traditions to any extent. It is concerned with the cultural construction of sickness and medicine among Hindu lay people and folk healers and employs folkloric material that, though rarely considered in anthropological writings on South Asia, may be fruitful guide to the meanings which sickness has for those experiencing and treating it.

Culture↗

Enhanced gamete interaction in the sperm penetration assay after coincubation with pentoxifylline and human follicular fluid.

OBJECTIVE: To evaluate the effect of pentoxifylline and heat-inactivated human follicular fluid (FF) on performance in the sperm penetration assay (SPA) as a paradigm for the effect of these agents on human sperm-egg interaction in vivo and in vitro fertilization. DESIGN: Semen specimens from men undergoing SPA testing for evaluation of suspected male factor infertility were coincubated with neat medium or media supplemented with pentoxifylline or human FF in a nonblinded manner. PARTICIPANTS: Twenty male factor infertility patients. INTERVENTIONS: Semen specimens were preincubated with: [1] pentoxifylline 0.25 mg/mL; [2] 10% human FF; [3] pentoxifylline+human FF; and [4] neat Biggers, Whitten, and Whittingham medium. MAIN OUTCOME MEASURES: Differences in the rate of penetration of zona-free hamster oocytes. RESULTS: Preincubation with either human FF or pentoxifylline produced a significant improvement in hamster egg penetration rates. Coincubation with a combination of human FF and pentoxifylline resulted in a significant enhancement of penetration as compared with single agent treatment. CONCLUSIONS: Coincubation of sperm with human FF and pentoxifylline may provide a means of enhancing sperm activity for insemination and assisted reproduction.

Animals↗

[Current treatment of poisoning by ingestion of caustic substances].

Lesions by ingestion of corrosive substances had so far been treated at the time of sequelae. In the seventies several events modified deeply the epidemiology and the early care of these poisonings. At that time household products like highly concentrated basic and acid substances and oxidizing agents were distributed and led to an increase of the number and the severity of these intoxications. In the same time, fiberoptic endoscopy of the digestive tract played a leading part to evaluate the diagnosis and the prognosis of these poisonings at an early stage, and thus, with accurate intensive care and digestive surgery contributed to generate appropriate guidelines, according to the severity. The first step of the treatment is fasting, fluid replacement and analgesic if required. A full examination must be performed, especially in the throat even if there is no strong correlation between early clinical signs and the severity of the lesions; blood samples must be obtained to look for metabolic acidosis, hyperleukocytosis hemolysis and consumption coagulopathy which could be better indicators of the severity. Fiberoptic endoscopy of the upper digestive tract should be performed as soon as the physical and psychological patient's condition is stable; if possible before the twelfth hour and no more late than the twenty-fourth hour. It should determine the lesions: type, range and grade according to Quincy's classification modified by Mongon and Di Constanzo. Survival and healing of "extremely severe" grade intoxication can only be obtained through a surgical intervention within the first hours; a laparotomy will indicate the depth of the lesions, which is not determined by endoscopy, and will consist of Celerier's stripping method and if necessary a gastrectomy, more seldom a cephalic duodeno-pancreatectomy. Only the surgical excision of necrotic tissues can prevent the occurrence of lethal complications like oesophageal or gastric perforations and septic shocks. The analysis of the literature from 1975 up to now gives us information on the methods and the results of these different therapeutic approaches.

Adult↗

[Current status of poisoning by ingestion of caustics: apropos of a series of 49 cases].

The authors report the history of 49 patients, admitted to an intensive care unit after a caustic or corrosive ingestion. This series follows a similar one, related in 1979. An update is made for early evaluation and management, based on patients classification in three groups: severe cases, moderate cases, mild cases. Clinical and biological data, treatment and outcome for the three groups are related. The frequency and gravity of these poisonings appear to be the same as in the first series, with poor prognosis for extreme emergencies and high risk of oesophageal or gastric stricture for important forms. In this population, 20% of extreme emergencies have favorable outcome with early major surgical procedure.

Adolescent↗