[A prospective and follow-up study of the health status of children. The course of labor in borderline measurement of the pelvic outlet].
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Child Development↗
Biomedical subjects
P Belfrage
Publications and source records attributed to P Belfrage.
Purification of the putative hormone-sensitive cyclic AMP phosphodiesterase from rat adipose tissue using a derivative of cilostamide as a novel affinity ligand.
A "low Km" cAMP phosphodiesterase with properties of a peripheral membrane protein accounts for approximately 90% of total cAMP phosphodiesterase activity in particulate (100,000 X g) fractions from rat fat cells. Incubation of fat cells with insulin for 10 min increased particulate (but not soluble) cAMP phosphodiesterase activity, with a maximum increase (approximately 100%) at 1 nM insulin. Most of the increase in activity was retained after solubilization (with non-ionic detergent and NaBr) and partial purification (approximately 20-fold) on DEAE-Sephacel. The solubilized enzyme from adipose tissue was purified approximately 65,000-fold to apparent homogeneity (yield approximately 20%) by chromatography on DEAE-Sephacel and Sephadex G-200 and affinity chromatography on aminoethyl agarose conjugated with the N-(2-isothiocyanato)ethyl derivative of the phosphodiesterase inhibitor cilostamide (OPC 3689). A 63,800 +/- 200-Da polypeptide (accounting for greater than 90% of the protein eluted from the affinity column) was identified by polyacrylamide gel electrophoresis in sodium dodecyl sulfate (with or without reduction). Enzyme activity was associated with the single protein band after electrophoresis under nondenaturing conditions. On gel permeation, Mr(app) was 100,000-110,000, suggesting that the holoenzyme is a dimer. A pI of 4.9-5.0 was estimated by isoelectric focusing. At 30 degrees C, the purified enzyme hydrolyzed both cAMP and cGMP with normal Michaelis-Menten kinetics; the pH optimum was 7.5. The Km(app) for cAMP was 0.38 microM and Vmax, 8.5 mumol/min/mg; for cGMP, Km(app) was 0.28 microM and Vmax, 2.0 mumol/min/mg. cGMP competitively inhibited cAMP hydrolysis with a Ki of approximately 0.15 microM. The enzyme was also inhibited by several OPC derivatives and "cardiotonic" drugs, but not by RO 20-1724. It was very sensitive to inhibition by agents which covalently modify protein sulfhydryls, but not by diisopropyl fluorophosphate. The activation by insulin and other findings indicate that the purified enzyme, which seems to belong to a subtype of low Km cAMP phosphodiesterases that is specifically and potently inhibited by cGMP, cilostamide, other OPC derivatives, and certain cardiotonic drugs, is likely to account for the hormone-sensitive particulate low Km cAMP phosphodiesterase activity of rat adipocytes.
3',5'-Cyclic-AMP Phosphodiesterases↗
Use of protein G for preparation and characterization of rabbit antibodies against rat adipose tissue hormone-sensitive lipase.
The newly described immunoglobulin G-binding streptococcal surface protein, protein G, was used to prepare and characterize rabbit antibodies. The antibodies were directed against rat hormone-sensitive lipase, the rate-limiting enzyme in the hydrolysis of the triacylglycerols stored in adipose tissue. Antiserum was obtained after two injections with 20 micrograms enzyme protein, and the immunoglobulin fraction was obtained using a protein G-based solid-phase radioimmunoassay. The hydrolysis of acylglycerols by the enzyme was inhibited by the antibodies, and the enzyme could be efficiently removed from a solution using the antibodies and heat-killed streptococci expressing surface protein G. By Western blot and detection with 125I-protein G, the antibodies were found to selectively bind to hormone-sensitive lipase and to a smaller extent to two minor contaminants, possibly proteolytic fragments of the lipase. The amount of 125I-labelled protein G bound to the lipase on the blot was quantitatively related to the amount of enzyme protein down to the detection limit 10 ng.
Adipose Tissue↗
[Fetal blood sampling by umbilical vein puncture guided by ultrasonics].
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Blood Specimen Collection↗
Hormone-sensitive lipase in brown adipose tissue: identification and effect of cold exposure.
Hormone-sensitive lipase (HSL) in brown adipose tissue from mice was identified through immunoprecipitation with a polyclonal antibody (anti-HSL) towards rat white fat HSL and Western blotting. An 82 kDa polypeptide, slightly smaller than the rat white fat HSL 84 kDa subunit, was detected and its identity as HSL verified by inhibition properties. The HSL concentration per g tissue was several-fold higher in the mouse brown adipose tissue than in the rat white adipose tissue, but the specific activities per mg protein were similar. Cold-exposure (4 degrees C) of the mice for 24 h approximately doubled the HSL concentration but this increase parallelled the overall protein increase and did not reflect a specific effect on the HSL.
Adipose Tissue, Brown↗
Latex agglutination test for alpha-fetoprotein in the diagnosis of premature rupture of the amniotic membranes (PROM).
A rapid latex agglutination test for alpha-fetoprotein (AFP) was compared with a pH-indicator and patient history in the detection of premature rupture of the amniotic membranes. Of 120 patients examined, 34 had an established rupture of the membranes, and 56 had suspected rupture. Thirty patients had no evidence of membrane rupture. The vaginal content was examined with a pH-indicator. Samples of vaginal content were also obtained to perform the latex agglutination test, and 103 of these samples were analysed by a radio-immunoassay (RIA) technique for AFP. Our results indicate that the latex agglutination test is of doubtful value due to the many inconclusive test results. The sensitivity of the latex test is less than 15%, and the specificity is 80%. Patient history combined with pH-indicator test is far more informative than the latex agglutination test.
Clinical Trials as Topic↗
Influence of pelvic outlet capacity on labor. A prospective pelvimetry study of 1,429 unselected primiparas.
The influence of pelvic outlet capacity on labor and the efficiency of routine low-dose radiological pelvimetry to anticipate dystocia during labor were studied prospectively among 1,429 unselected term primiparas, all having fetal head presentation and normal pregnancy. Outlet contraction was found in 0.9% and borderline outlet measurement in 5.3%. In 1,402 cases labor started spontaneously and 83 emergency cesarean sections were done. The incidence of cesarean section because of dystocia increased in inverse proportion to decreasing pelvic outlet capacity. The incidence of other emergency cesarean sections was not influenced by pelvic outlet size. In 79% of cesarean section interventions due to dystocia, pelvic outlet capacity was normal. Apgar score less than 7 at one minute was more commonly associated with a small pelvic outlet. Apgar score at 5 minutes and neonatal morbidity were not influenced by pelvic outlet size. Pelvic outlet capacity had a marked influence on the mode of delivery, but the practical value of radiological pelvimetry by fetal head presentation is rarely considered, except in very selected cases.
Cesarean Section↗
Influence of the pelvic outlet capacity on fetal head presentation at delivery.
The influence of pelvic outlet capacity on fetal head presentation in 1,402 term primiparas with normal pregnancies was studied. In all cases radiological pelvimetry was carried out and labor started spontaneously. Occiput posterior (OP) delivery occurred in 5.1%. As pelvic outlet capacity decreased an increased frequency of OP presentations and need for epidural anesthesia (EDA) was found. With OP presentation the duration of labour was longer, the frequency of EDA, instrumental delivery, cesarean section and low Apgar score at 1 minute were all higher, all compared with occiput anterior (OA) presentation. No difference in fetal morbidity was found. When the influence of the pelvic outlet capacity was eliminated through comparison of matched groups, the course of delivery became more similar whether the presentation was OA or OP and the frequency of EDA became the same. Reduced pelvic outlet capacity seemed to be one cause of both OP presentation and the use of EDA.
Anesthesia, Epidural↗
Routine or selective ultrasound examinations in early pregnancy.
Two thousand fifty-four women were routinely screened with ultrasound in the tenth to 14th week of pregnancy. The clinical outcome was compared with a group of 1358 gravidas examined selectively with ultrasound. In the test group, 95% of all women had an ultrasound examination early in pregnancy; the corresponding figure in the control group was 50%. Neonatal outcome was similar, but the frequency of labor inductions decreased in the group routinely screened with ultrasound. Induction of labor for suspected postdatism increased the risk for emergency cesarean section in comparison with spontaneous onset of labor. In about 20% of all cases, prediction of the time of delivery was altered according to the ultrasound examination, and analysis of the patients with spontaneous onset of labor showed that ultrasound was a better predictor of the time of delivery than was the last menstrual period.
Cesarean Section↗
Phosphorylation of the basal site of hormone-sensitive lipase by glycogen synthase kinase-4.
In rat adipocytes hormone-sensitive lipase is phosphorylated at two sites termed 'regulatory' and 'basal', in the former case by cyclic AMP-dependent protein kinase causing an activation of the lipase [(1984) Proc. Natl. Acad. Sci. USA 81, 3317-3321]. Here, the basal phosphorylation site was found to be phosphorylated by glycogen synthase kinase-4 without any effects on lipase activity, or on the extent of its activation subsequent to phosphorylation of the regulatory site. Glycogen synthase kinase-3, casein kinase-I, and casein kinase-II did not phosphorylate the lipase. Phosphorylase kinase phosphorylated it to a very low extent at a third phosphorylation site not phosphorylated in the fat cell.
Adipose Tissue↗
Demonstration of the amphiphilic character of hormone-sensitive lipase by temperature-induced phase separation in Triton X-114 and charge-shift electrophoresis.
Temperature-induced phase separation in Triton X-114 (Bordier, C. (1981) J. Biol. Chem. 256, 1604-1607) and charge-shift electrophoresis (Helenius, A., and Simons, K. (1977) Proc. Natl. Acad. Sci. U. S. A. 74, 529-532) were used to examine the amphiphilic character of hormone-sensitive lipase, purified from rat adipose tissue. In contrast to ATP-citrate lyase, a reference hydrophilic protein, the lipase was shown to partition predominantly (approximately 80%) into the detergent-rich phase upon phase separation in Triton X-114. Furthermore, its electrophoretic mobility was markedly shifted anodally and cathodally upon charge-shift electrophoresis in the presence of sodium taurodeoxycholate and cetyltrimethylammonium bromide, respectively. The results demonstrate that hormone-sensitive lipase possesses detergent-binding hydrophobic domain(s) and exhibits the same amphiphilicity as typical intrinsic membrane proteins.
ATP Citrate (pro-S)-Lyase↗
The acute GH action in rat adipocytes is associated with enhanced phosphorylation of a 46 kDa plasma membrane protein enriched by GH-Sepharose.
The acute anti-lipolytic effect of human growth hormone (hGH) in maximally noradrenaline-stimulated intact rat adipocytes was selectively associated with increased phosphorylation of a 46 kDa plasma membrane protein which was highly enriched by hGH-Sepharose chromatography. The same protein was also phosphorylated by an endogenous protein kinase in isolated plasma membranes, although then no hGH effect could be demonstrated. About 14% of the phosphate incorporated into the protein in isolated plasma membranes was found in tyrosine residues and the remainder in serine and threonine. The possible relation of the 46 kDa protein with the hGH plasma membrane receptor is discussed.
Adipose Tissue↗
Purification of hormone-sensitive lipase by high-performance ion exchange chromatography.
We have developed an improved method for purification of hormone-sensitive lipase from adipose tissue. The method employs two preparative high-performance ion-exchange chromatography steps on Mono Q and Mono S after detergent solubilization and partial fractionation of the enzyme by gradient sievorptive chromatography on QAE-Sephadex. About 0.2 mg of greater than 70% pure enzyme is prepared at 10% yield within 6-7 days from adipose tissue of 500 rats. This protocol is a major improvement over the previously established procedure in terms of accessibility, rapidity, enzyme purity, and yield.
Adipose Tissue↗
Hormone-sensitive lipase and monoacylglycerol lipase are both required for complete degradation of adipocyte triacylglycerol.
The respective roles of monoacylglycerol lipase and hormone-sensitive lipase in the sequential hydrolysis of adipose tissue triacylglycerols have been examined. An adipose tissue preparation, containing both lipases in approximately the same proportion as in the intact tissue, hydrolyzed emulsified tri- or dioleoylglycerol to fatty acids and glycerol, with little accumulation of di- or monooleoylglycerol. Selective removal of the monoacylglycerol lipase by immunoprecipitation markedly reduced the glycerol release. Isolated hormone-sensitive lipase hydrolyzed acylglycerols with a marked accumulation of monoacylglycerol in accordance with the positional specificity of this enzyme (Fredrikson, G. and Belfrage, P. (1983) J. Biol. Chem. 258, 14253-14256). Addition of increasing amounts of isolated monoacylglycerol lipase led to a corresponding increase in glycerol release, due to hydrolysis of the monoacylglycerols formed. The reaction proceeded to completion when the relative proportion of the two lipases was similar to that in the intact tissue. These findings indicate that hormone-sensitive lipase catalyzes the hydrolysis of triacylglycerol in the rate-limiting step of adipose tissues lipolysis, and of the resulting diacylglycerol, whereas the action of monoacylglycerol lipase is required in the final hydrolysis of the 2-monoacylglycerols produced.
Adipose Tissue↗
The pelvic outlet. A comparison between clinical evaluation and radiologic pelvimetry.
A random sample of 798 primiparas was screened with clinical evaluation and radiologic low-dose pelvimetry of the pelvic outlet. The purpose was to study the accuracy of clinical evaluation in comparison with X-ray pelvimetry and to determine whether clinical evaluation could reveal any other factor influencing labor. A significant agreement between clinical and X-ray pelvimetry was found, but the sensitivity of clinical evaluation was low and as many as half the patients with a contracted pelvis, according to pelvimetry, were not detected. Delivery outcomes in two matched groups with similar pelvic outlet measurements but different clinical evaluation did not differ, indicating that clinical evaluation did not detect any other factor not revealed by X-ray pelvimetry.
Delivery, Obstetric↗
Comparison between the conventional Malmström extractor and a new extractor with Silastic cup.
One hundred women for whom instrumental delivery had to be performed due to fetal asphyxia or uterine inertia were randomized to a vacuum extraction with the conventional Malmström instrument or the Silastic cup of Kobayashi. With the Silastic cup, extraction time was shorter and injuries to the scalp were less common. On the other hand, extraction with the Silastic cup failed more often, especially in occiput posterior position. There were no differences in Apgar scores between the two groups.
Clinical Trials as Topic↗
[The mechanism of action of insulin is an unsolved problem--new discoveries can explain the effects].
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Animals↗
Phosphorylation of hormone-sensitive lipase by cyclic GMP-dependent protein kinase.
In intact rat adipocytes hormone-sensitive lipase has been shown to be phosphorylated on serine residues in two different phosphorylation sites: a regulatory site phosphorylated by cyclic AMP-dependent protein kinase and a basal site, which does not directly affect the enzyme activity, phosphorylated by cyclic AMP-independent protein kinase(s) [(1984) Proc. Natl. Acad. Sci. USA 81, 3317-3321]. Cyclic GMP-dependent protein kinase catalyzed the phosphorylation of the same two phosphorylation sites on the isolated enzyme, at serine residues. Both sites were phosphorylated at about the same rate, with the hormone-sensitive lipase activity concomitantly enhanced.
Adipose Tissue↗