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M Pelosi

Publications and source records attributed to M Pelosi.

11 recordsLinked to original sources
PubMed1996

Colocalization of the dihydropyridine receptor, the plasma-membrane calcium ATPase isoform 1 and the sodium/calcium exchanger to the junctional-membrane domain of transverse tubules of rabbit skeletal muscle.

The subcellular distribution of the calmodulin-stimulated plasma-membrane Ca(2+)-ATPase (PMCA) has been studied in rat and rabbit skeletal muscle cells by indirect (calmodulin gel overlays) and direct (Western blotting with specific antibodies) methods. It has also been studied in situ in immunocytochemistry experiments. The distribution of PMCA has been compared with that of the NA+/Ca2+ exchanger and of the dihydropyridine receptor, which has been studied by Western blotting with specific antibodies. Both PMCA and the Na+/Ca2+ exchanger had a dual localization, i.e., they were found in the plasma membrane and in the transverse-tubule fractions of the two main types of skeletal muscles studied. The pump and the exchanger were not diffusely distributed in the transverse-tubule-membrane system, but specifically confined to the membrane domain where the dihydropyridine receptor was also localized, i.e., the junctional membrane. Experiments with isoform-specific antibodies have shown that the pump isoform expressed in skeletal muscle is PMCA 1.

Animals↗
PubMed1996

Skeletal muscle sarcoplasmic reticulum phenotype in myotonic dystrophy.

In this study we investigated the sarcoplasmic reticulum (SR), alongside myofibrillar phenotype, in muscle samples from five Myotonic Dystrophy (DM) patients and five control individuals. DM muscles exhibited as a common feature, a decrease in the slow isoform of myosin heavy chain (MHC) and of troponin C in myofibrils. We observed a match between myofibrillar changes and changes in SR membrane markers specific to fiber type, i.e. the fast (SERCA1) Ca(2+)-ATPase isoform increased concomitantly with a decrease of protein phospholamban (PLB), which in native SR membranes colocalizes with the slow (SERCA2a) SR Ca(2+)-ATPase, and regulates its activity depending on phosphorylation by protein kinases. Our results outline a cellular process selectively affecting slow-twitch fibers, and non-degenerative in nature, since neither the total number of Ca(2+)-pumps or of ryanodine receptor/Ca(2+)-release channels, or their ratio to the dihydropyridine receptor/voltage sensor in junctional transverse tubules, were found to be significantly changed in DM muscle. The only documented, apparently specific molecular changes associated with this process in the SR of DM muscle, are the defective expression of the slow/cardiac isoform of Ca(2+)-binding protein calsequestrin, together with an increased phosphorylation activity of membrane-bound 60 kDa Ca(2+)-calmodulin (CaM) dependent protein kinase. Enhanced phosphorylation of PLB by membrane-bound Ca(2+)-CaM protein kinase also appeared to be most pronounced in biopsy from a patient with a very high CTG expansion, as was the overall 'slow-to-fast' transformation of the same muscle biopsy. Animal studies showed that endogenous Ca(2+)-CaM protein kinase exerts a dual activatory role on SERCA2a SR Ca(2+)-ATPase, i.e. either by direct phosphorylation of the Ca(2+)-ATPase protein, or mediated by phosphorylation of PLB. Our results seem to be consistent with a maturational-related abnormality and/or with altered modulatory mechanisms of SR Ca(2+)-transport in DM slow-twitch muscle fibers.

Adolescent↗
PubMed1984

Bacterial colonization of amniotic fluid in patients with intact membranes during labor.

Amniotic fluid from gravidas with intact membranes was obtained for bacteriologic culture at the time of cesarean section. The incidence of positive cultures from patients not in labor was 8%. When the length of labor was eight hours or less (mean 6.1 hours) and the membranes were intact, the incidence of positive cultures was 37%; in patients whose length of labor was 12 hours or less (mean 9.7 hours) with intact membranes, 55% of cultures were positive. The incidence of endomyometritis in patients with bacterial growth from the amniotic fluid cultures in each group was 33%, 33%, and 45%, respectively.

Amniotic Fluid↗
PubMed1982

Prophylactic antibiotics for cesarean section: comparison of high- and low-risk patients for endomyometritis.

The efficacy of ticarcillin in the prevention of post-cesarean section endomyometritis was studied in 259 women randomly given either the antibiotic or a placebo. The ticarcillin group received 6 g intravenously immediately after delivery. Then 22 of those patients were also given a second 3-g dose 6 to 8 hours after delivery. Among the 139 patients who received ticarcillin, endomyometritis developed in 44 (32%), as it did in 66 of 120 patients (55%) in the placebo group. These differences are highly significant (P = .002). Of the 259 patients in the study, 238 could be classified as to risk for endomyometritis developing. Among the 124 high-risk patients, 52 received a placebo and endomyometritis developed in 71%. Only 26 of the 72 high-risk patients who received ticarcillin (36%) were so infected. Among the low-risk patients, endomyometritis developed in 10 of 54 patients (18.5%) who received prophylaxis and in 24 of 60 patients who received placebo (40%). Ticarcillin appears to be effective in reducing the incidence of post-cesarean section endomyometritis in patients at high risk and in those at low risk. The number of pelvic examinations during labor was the most important single factor in the development of endomyometritis.

Adult↗
PubMed1975

Prophylactic internal iliac artery ligation at cesarean hysterectomy.

One hundred and eight preplanned cesarean hysterectomies have been evaluated in an effort to determine that advisability of prophylactic bilateral hypogastric artery ligation when there is anticipated heavy bleeding associated with surgery. The data indicates that prophylactic bilateral internal iliac artery ligation is of questionable value in reducing operative bleeding, which can be controlled by more conventional means. However, when used therapeutically, it may be a lifesaving operation. Familiarity with the procedure is necessary for all those performing operative obstetrics and gynecology.

Adult↗
PubMed1975

Renal carcinoma in pregnancy.

A gravid patient presented with gross hematuria in the last trimester of pregnancy but did not permit diagnostic measures. After delivery a large abdominal mass, which proved to be renal cell carcinoma, was found. Previously reported cases are reviewed, and the importance of adequate workup of hematuria during pregnancy is emphasized.

Adenocarcinoma↗
PubMed1975

Comparison of sterilization by tubal ligation and hysterectomy.

A comparison was made between sterilization by hysterectomy and by tubal ligation at the time of cesarean section and as an interval procedure. All operations were done at one institution and, essentially, by the same physician population, allowing for promotion within the residency program. The major deterrent to hysterectomy was the associated high incidence of necessary blood transfusion. However, a hysterectomy does offer the benefits of a permanent and completely effective procedure and the removal of an organ which ultimately may be the source of other problems. If another pathologic condition exists, making ultimate hysterectomy likely, it is the procedure of choice for sterilization, avoiding risks, costs, and the inconvenience of another operation. Methods of elective sterilization must be individualized. If the patient is appraised of the increased risk of hysterectomy and desires this more definitive procedure on the basis of informed consent, the incidence of complications is not prohibitive. These should not deter the well trained surgeon but should mandate use of all available skills, intensive evaluation of the patient, and concerned recognition of the potential adverse consequences.

Abscess↗