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M J Gast

Publications and source records attributed to M J Gast.

35 records · Page 2Linked to original sources
PubMed1988

Purification and characterization of human myometrial smooth muscle collagenase.

Collagenase has been purified from the culture medium of a human myometrial smooth muscle cell line, and the properties of the pure enzyme compared to those of collagenase from another human mesenchymal cell, the fibroblast. The smooth muscle collagenase was purified using a new, rapid, and convenient three-step purification procedure consisting of chromatography on iminodiacetate-agarose chelated with zinc and on Cibacron Blue-agarose followed by gel filtration on Ultrogel AcA-44. The resultant pure collagenase is secreted as a zymogen indistinguishable from that of the fibroblast enzyme in molecular weight, amino acid composition, and in the nature of its conversion to active enzyme by trypsin. The amino acid sequence of the two enzymes at the trypsin cleavage site is the same. The two collagenases are also indistinguishable immunologically and display essentially identical kinetic behavior on a variety of collagen substrates. Although the two collagenases appear to be identical proteins, the mechanisms which regulate their production appear to be very different. Glucocorticosteroids, which inhibit collagenase production in human skin fibroblasts are without effect in the uterine smooth muscle cell. In contrast, the smooth muscle cell appears to require a component present in fetal bovine serum in order to produce the enzyme.

Amino Acids↗
PubMed1988

Laser vaporization of endometriosis in an infertile population: the role of complicating infertility factors.

One hundred twenty-two infertility patients with endometriosis were evaluated and treated using laparoscopy and laser vaporization to provide immediate elimination of all intraperitoneal disease. Ninety-five couples (77.8%) had one or more infertility factors (other than endometriosis) contributing to their infertility. Cervical factors, male factors, and luteal defects were associated with significantly decreased pregnancy rates, despite the use of laser vaporization. The number of contributing factors seemed to be unrelated to the likelihood of success in achieving pregnancy. The authors emphasize the need for total evaluation of other infertility factors in these patients. Such factors should be corrected prior to the use of laser laparoscopy, if possible, and dealt with on a continuing basis following use of this technique.

Endometriosis↗
PubMed1988

Tumor necrosis factor in peritoneal fluid of women undergoing laparoscopic surgery.

The level of tumor necrosis factor (TNF) in peritoneal fluid (PF-TNF) of 74 women undergoing laparoscopy was determined. The difference between the mean concentration of PF-TNF of women with normal pelvic anatomy and women with moderate or severe endometriosis was significant (P less than 0.01). The proportion of PF-TNF-positive women with PID and those with moderate or severe endometriosis was also significantly higher when compared to women with normal pelvic anatomy (P less than 0.05; P less than 0.02). The proportion of PF-TNF positive women among nulligravid and nulliparous women was significantly higher than that of women with two or more pregnancies (P less than 0.01) and two or more deliveries (P less than 0.005). These results indicate that the presence of PF-TNF is associated with primary infertility and endometriosis.

Adolescent↗
PubMed1987

Constancy of serum angiotensin-converting enzyme activity in normal and complicated pregnancy.

Angiotensin-converting enzyme occupies a central position in the dynamics of the renin-angiotensin system. We prospectively studied serum angiotensin-converting enzyme activity in 112 women at various stages of pregnancy and in the postpartum period because converting enzyme levels have not been well documented in pregnant women with medical disorders which might be expected to influence intravascular volume or blood pressure. Enzyme activity is lower during pregnancy than it is in the same population at 6 weeks postpartum. Levels of serum angiotensin converting enzyme activity remain relatively stable during gestation but drop during the immediate postpartum period. Diabetes, chronic hypertension, and pregnancy induced hypertension fo not markedly change serum angiotensin converting enzyme activity.

Female↗
PubMed1987

Polymyositis in pregnancy. A case report and literature review.

Polymyositis is a myositic disease that is rarely seen as a complicating condition of pregnancy. As with other connective tissue diseases, previously reported cases of polymyositis have been associated with increased perinatal mortality and maternal morbidity. We treated a patient in whom two pregnancies had been complicated by polymyositis. In the second of these gestations, aggressive management, including maintenance therapy with oral corticosteroids, contributed to a successful outcome.

Adult↗
PubMed1986

Amniotic fluid collagenase inhibitor: correlation with gestational age and fetal lung maturity.

Concentrations of collagenase inhibitor in amniotic fluid correlated with gestational age and with indices of fetal lung maturity such as the lecithin/sphingomyelin ratio and the presence of phosphatidylglycerol. Possible sources of amniotic fluid collagenase inhibitor were sought, and a number of tissues and fluids, both maternal and fetal in origin, were found to contain or synthesize this glycoprotein in significant quantities. The highest concentrations were achieved in cultures of lung fibroblasts implicating the fetal lung as a major source. Although collagenase inhibitor is largely present in a free or available state, its specific role, other than that of a general antiproteinase, has not been determined in amniotic fluid. However, the quantitation of amniotic fluid collagenase inhibitor provides an index of the maturation of the connective tissue of the fetal lung and may reflect the ability of the extracellular matrix to meet neonatal demands.

Amniotic Fluid↗
PubMed1985

Antenatal diagnosis of cystic adenomatoid malformation: effect on patient management.

Congenital adenomatoid malformation (CAM) of the lung was diagnosed at 30 weeks gestation. The mother presented with preterm labor and polyhydramnios. A complex cystic mass was seen in the right lung of the fetus. Additional radiographic and sonographic investigations prior to delivery allowed differentiation of this rare lesion from other cystic thoracic pathology of the fetal period. Careful hospital obstetric management of the mother and fetus for over 3 weeks allowed the delivery of an infant with adequate pulmonary maturity to permit stabilization and surgery on the baby in the first days of life.

Adult↗
PubMed1985

Class H diabetes and pregnancy.

Class H diabetes is defined as the presence of diabetes of any duration associated with ischemic myocardial disease. Because of a lack of experience with the coexistence of myocardial ischemic disease and diabetes during pregnancy, it is difficult to offer patients an accurate prognosis for mother and infant during such a gestation. Previous reports suggest that outcomes in this situation are almost routinely poor. It is likely, however, that there is a subset of patients within the class H diabetic population in whom pregnancy can be successful. Reported are the pregnancies of three such patients. The authors suggest that careful attention to cardiac status and glycemic control contribute to both maternal and fetal well-being. Prepregnancy screening of class H patients for evidence of cardiac dysfunction may allow for the screening of those class H diabetic women who are most likely to achieve successful pregnancy outcome.

Adult↗
PubMed1984

Variable denaturation of ovalbumin by incorporation of amino acid analogs.

Denaturation of hen ovalbumin synthesized in a cell-free system was assayed by examining its sensitivity to trypsin. The native ovalbumin resisted digestion by trypsin, and it remained resistant to digestion when some amino acid analogs, including azetidine-2-carboxylic acid and meta-flourotyrosine, were incorporated into its peptide chain. However, when other amino acid analogs such as beta-hydroxyleucine and 4-thiaisoleucine were incorporated during protein systhesis, ovalbumin became very lablie to trypsin. These experiments demonstrate a sensitive system for detecting protein denaturation and suggest a variable effect of different amino acid analogs on the native conformation of a protein.

Animals↗
PubMed1983

Characterization of preprorelaxin by tryptic digestion and inhibition of its conversion to prorelaxin by amino acid analogs.

We studied the in vitro synthesis of relaxin--an ovarian protein hormone related to the insulin subset of growth factors. RNA isolated from corpora lutea of pregnant sows directed the synthesis of a Mr = 23,000 protein in an ascites tumor cell-free system. This protein contained all of the cysteine-bearing tryptic peptides of relaxin as determined by precise co-migration of tryptic fragments of relaxin precursor generated in vitro and those of highly purified relaxin isolated from sow ovary. Based upon these data, it is likely that the primary translation product of porcine relaxin shares structural homology with preproinsulin. The Mr = 23,000 precursor to relaxin is converted to a Mr = 20,000 prohormone in the presence of ascites microsomal membranes. This conversion and the membrane translocation phenomenon which accompanies it can be inhibited in vitro by the use of beta-hydroxyleucine, an amino acid analog. Use of amino acid analogs may represent a technique to allow study of the conversion of relaxin precursors to relaxin in the luteal cell.

Amino Acid Sequence↗
PubMed1983

Maternal hydrocephalus and pregnancy.

Women with cerebrospinal fluid (CSF) shunts for correction of hydrocephalus are rapidly joining the reproductive age population. These patients can have uncomplicated pregnancies and spontaneous vaginal deliveries. Careful attention to signs of CSF shunt malfunction, historical and ultrasonic screening for familial hydrocephalus, and antibiotic prophylaxis for delivery are recommended. Management of the first and second stages of labor is discussed. There is no apparent advantage to any particular technique for intrapartum analgesia.

Adult↗
PubMedDate not supplied

Expression of engineered human 17 beta-estradiol dehydrogenase in a prokaryotic system.

OBJECTIVE: 17 beta estradiol dehydrogenase (17 beta DH) is a model for pyridine-dependent steroid-converting enzymes. To define the structural and functional parameters of 17 beta DH, we created an expression system for production of abundant, homogeneous enzyme. METHODS: A full-length 17 beta DH cDNA clone was engineered into the inducible expression vector pMON 5839. After induction of plasmid-bearing Escherichia coli JM109 cells, the authenticity of the recombinant human placental 17 beta DH (r17 beta DH) was evaluated. RESULTS: Protein electrophoresis and Western blot analysis confirmed the immunologic identity of r17 beta DH with native human placental enzyme. The amino acid sequence, enzyme activity, Vmax, K(m), and kcat of r17 beta DH matched that of the native enzyme. CONCLUSION: Prokaryotic cell lines offer the opportunity to create an unlimited supply of recombinant human placental 17 beta DH without the expense and time commitment of baculoviral or eukaryotic cell lines. We are now able to use r17 beta DH and its mutants to elucidate the mechanisms of action of this class of enzyme.

Amino Acid Sequence↗
PubMedDate not supplied

Regulation of creatine kinase isoenzymes in human placenta during early, mid-, and late gestation.

OBJECTIVE: Creatine kinase (CK) isoenzymes play an important role in cellular energy transduction. Two isoenzymes of creatine kinase, ubiquitous mitochondrial creatine kinase (uMtCK) and cytosolic brain creatine kinase (BCK), are postulated to form the creatine phosphate (CP) shuttle, in which creatine serves to transport high-energy phosphate from the mitochondria to its site of utilization. Coordinate regulation of these genes is essential for efficient energy transduction. We examined human CK isoenzyme regulation in placentas during all three trimesters of gestation to define the mRNA and protein expression patterns of uMtCK and BCK and to test the CP shuttle hypothesis. METHODS: Placental samples were collected from a total of 26 patients from the first, second, and third trimesters. Total RNA and protein were prepared from each sample and quantified. Quantitative RNA analysis was performed by gel electrophoresis and dot blot techniques using isoenzyme-specific human cDNA probes for uMtCK and BCK. Protein expression of uMtCK and BCK was examined by Western blot analysis using isoenzyme-specific antibodies to uMtCK and BCK. RESULTS: Analysis of RNA demonstrated the coordinate expression of uMtCK and BCK mRNAs in human placenta, with peak expression of both in the term placentas. Western blot analysis demonstrated coordinate expression of uMtCK and BCK proteins in the first and second trimesters, but not in the term placenta. Expression levels of uMtCK and BCK proteins were not consistent with their respective mRNA levels in the term placenta. CONCLUSION: Expression of uMtCK and BCK in human placenta is highly regulated, and post-transcriptional regulation of uMtCK and BCK expression occurs in the term placenta. The coordinate regulation of uMtCK and BCK in human placenta supports the CP shuttle hypothesis. This analysis demonstrates that human placenta has high energy needs that can change rapidly; thus, a functioning CP shuttle may be important in the maintenance and termination of pregnancy.

Blotting, Northern↗