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Biomedical subjects

H Zakut

Publications and source records attributed to H Zakut.

At least 109 records · Page 6Linked to original sources
PubMed1987

A new biological carrier for follicle stimulating hormone: an aid for the diagnosis of menopause.

The excretion of follicle stimulating hormone (FSH) was measured in urine samples collected every 2 weeks and on biological carriers (sticks) collected for 15-30 weeks from 10 perimenopausal women aged 38-53 (median 48 years), with a recent history of irregular menstrual cycles following regular cyclicity. In the 3 months preceding the menopause, long cycles were common and 8 of the 10 women experienced intermenstrual intervals lasting 50 days. FSH excretion was usually elevated to within the postmenopausal range (less than 8 mIU/ml), and only 1 woman excreted the low levels which are characteristic of fertile young women. Overall, FSH levels were higher in the period between 15 and 20 weeks after the menopause (18.3 +/- 6.2 mIU/ml) than in the first 4 weeks (9.6 +/- 5.2 mIU/ml). 95% correlation was found in parallel measurements of FSH attached to the biological carrier, the stick. It is proposed that the biological carrier, the stick, for FSH measurements in urine samples can help physicians to distinguish intervals of amenorrhea from the menopause: 2-3 measurements of FSH attached to the stick in an interval of 1 week can give a reliable answer.

Adult↗
PubMed1987

Combined pelvic sonography and serum beta hCG, versus laparoscopy for the diagnosis of stable patient suspected of ectopic pregnancy.

The role of sonography in stable patients suspected of ectopic pregnancy is to establish the diagnosis using positive, suggestive or negative signs. Establishing whether or not intrauterine gestation is present is crucial, as is the detection of any extrauterine abnormality. Sonography may be normal in ectopic pregnancy or when it is not abnormal findings are frequently nonspecific. Therefore, the sonographic results must be correlated and integrated with the clinical history and findings as well as with other diagnostic procedures. The combination of ultrasound scanning with beta hCG was found highly contributory to the determination of the existence of an ectopic pregnancy. Understanding the objectives and limitations of each diagnostic test involved is essential for logical and optimal sequences of diagnostic procedures to be employed in patient management. During a twenty-month period, 138 patients were examined due to clinical suspicion of "sub-acute" ectopic pregnancy. Sixty-one patients were managed according to a non-invasive protocol composed of: a) ultrasound scanning alone and b) ultrasound scanning combined with serum beta subunit hCG. Ultrasonograms for ectopic pregnancy diagnosis were coded: positive (fluid in cul-de-sac or extrauterine sac); suggestive empty uterus, adnexal mass and pseudo-gestational sac) and negative (intrauterine gestational sac and normal pelvis). Surgical procedure was carried out immediately on nine patients with positive signs; all of them had ectopics. Suggestive signs were found in twenty-two patients. beta subunit hCG was determined prior to interventive procedure; ectopic pregnancy was revealed in eighteen of them. Among thirty patients with negative signs, only two patients (7% of this sub-group or 3.5% of the general group) had ectopics.(ABSTRACT TRUNCATED AT 250 WORDS)

Chorionic Gonadotropin↗
PubMed1987

Vaginal preparation with povidone-iodine before abdominal hysterectomy. A comparison with antibiotic prophylaxis.

Two groups of women were prepared before total abdominal hysterectomy. The first by povidone-iodine tampons that remained in the vagina until the end of the operation, the second group by administration of a prophylactic antibiotic. We found statistically significant decreases both in infectious morbidity and in the percentage of positive cultures from the cervix and vagina, at the time of the operation in the povidone-iodine group as compared with the antibiotic group. Therefore, it is our impression that prophylactic antibiotic therapy for patients undergoing abdominal hysterectomy should be reserved for the patient with compromised defence mechanisms if it is used at all, and recommend local preparation of the vagina with povidone-iodine as an effective alternative.

Administration, Intravaginal↗
PubMed1987

Fetal heart rate and uterine activity following paracervical block.

Bupivacaine without adrenaline was used for paracervical block (PCB) anesthesia in 60 low-risk parturients in whom there were no signs of fetal asphyxia. In order to evaluate its effects on fetus and uterine activity, 30 patients were given a "high dose" of 50 mg Bupivacaine, an amide-type local anesthetic agent, while 30 patients were given a "low dose" of 25 mg. Continuous fetal heart rate (FHR) monitoring in both study groups revealed nine patients with typically post PCB bradycardia and five patients with moderate PHR depression. All of them were born with excellent Apgar score. Although a decrease in fetal heart rate following PCB was noted in both groups more significant reduction was associated with the high dose block (P less than 0.05). In 11 cases, FHR depression was clearly associated with increased uterine activity, while in another three cases it was not (P less than 0.005). Oxytocin administration during the block did not affect fetal heart rate or uterine activity. The results indicate that FHR depression following PCB using Bupivacaine is dose dependent, transient and not dangerous to a normal fetus. No adverse maternal effects were noted. It is suggested that fetal heart rate depression following PCB using Bupivacaine is related to increased uterine activity.

Anesthesia, Caudal↗
PubMed1986

Gonadotropin-releasing hormone activates a rapid Ca2+-independent phosphodiester hydrolysis of polyphosphoinositides in pituitary gonadotrophs.

Addition of gonadotropin releasing hormone (GnRH) to pituitary cells prelabeled with [32P]Pi or with myo-[2-3H]inositol, resulted in a rapid decrease in the level of [32P]phosphatidylinositol 4,5-bisphosphate (approximately 10 s), and in [32P]phosphatidylinositol 4-phosphate (approximately 1 min), followed by increased labeling of [32P]phosphatidylinositol and [32P]phosphatidic acid (1 min). GnRH stimulated the appearance of [3H]myo-inositol 1,4,5-trisphosphate (10 s), [3H]myo-inositol 1,4-bisphosphate (15 s), and [3H]myo-inositol 1-phosphate (1 min) in the presence of Li+ (10 mM). Li+ alone stimulated the accumulation of [3H]myo-inositol 1-phosphate and [3H]myo-inositol 1,4-bisphosphate but not [3H]myo-inositol 1,4,5-trisphosphate, but had no effect on luteinizing hormone release. The effect of GnRH on inositol phosphates (Ins-P) production was dose-related (ED50 = 1-5 nM), and was blocked by a potent antagonist [D-pGlu,pClPhe,D-Trp]GnRH. Elevation of cytosolic free Ca2+ levels ([Ca2+]i), by ionomycin and A23187 from intracellular or extracellular Ca2+ pools, respectively, had no significant effect on [3H]Ins-P production. GnRH-induced [3H]Ins-P production was not dependent on extracellular Ca2+ and was noticed also after extracellular or intracellular Ca2+ mobilization by A23187 or ionomycin, respectively. The effect of GnRH on [3H]Ins-P accumulation was not affected by prior treatment of the cells with the tumor promoter phorbol ester 12-O-tetradecanoylphorbol-13-acetate or with islet-activating protein pertussis toxin. These results indicate that GnRH stimulates a rapid phosphodiester hydrolysis of polyphosphoinositides. The stimulatory effect is not mediated via an islet-activating protein-substrate, is not dependent on elevation of [Ca2+]i, neither is it negatively regulated by 12-O-tetradecanoylphorbol-13-acetate which activates Ca2+/phospholipid-dependent protein C kinase. The results are consistent with the hypothesis that GnRH-induced phosphoinositide turnover is responsible for Ca2+ mobilization followed by gonadotropin release.

Animals↗
PubMed1986

The use of mRNA translation in vitro and in ovo followed by crossed immunoelectrophoretic autoradiography to study the biosynthesis of human cholinesterases.

The synthesis of various cholinesterases in different fetal human tissues was studied using in vitro and in ovo translation of poly(A)+ RNA, followed by crossed immunoelectrophoretic autoradiography. When unfractionated poly(A)+ mRNA from fetal brain, muscle, or liver was translated in vitro, in the reticulocyte lysate cell-free system, polypeptides were synthesized which reacted with antibodies against either "true" acetylcholinesterase (acetylcholine hydrolase; EC 3.1.1.7) or "pseudo", butyrylcholinesterase (acylcholine acylhydrolase; EC 3.1.1.8). The two nascent cholinesterases could be separated by crossed immunoelectrophoresis followed by autoradiography, suggesting that acetylcholinesterase and butyrylcholinesterase are produced in all three tissues from nascent polypeptides containing different immunological domains. To examine whether the biosynthesis of cholinesterases includes posttranslational processing events, Xenopus oocytes were microinjected with mRNA from these tissues. Immunoelectrophoretic analysis of oocyte intracellular homogenates and incubation medium revealed various precipitation arcs, reflecting the synthesis and posttranslational processing of multiple forms of tissue-specific exported and intracellular acetylcholinesterase and butyrylcholinesterase. These findings demonstrate that polymorphic cholinesterases are produced from nascent polypeptide products which undergo further posttranslational processing events in a tissue-specific manner before they become mature compartmentalized cholinesterases.

Acetylcholinesterase↗
PubMed1986

Divergent regulation of muscarinic binding sites and acetylcholinesterase in discrete regions of the developing human fetal brain.

The expression of muscarinic acetylcholine binding sites and of cholinesterases was studied in extracts prepared from discrete regions of the human fetal brain, between the gestational ages of 14 and 24 weeks. The specific binding of [3H]N-methyl-4-piperidyl benzilate [( 4H]-4NMPB) to muscarinic binding sites ranged between 0.05 and 1.30 pmol/mg protein in the different brain regions, with Kd values of 1.2 +/- 0.2 nM. Binding of the cholinergic agonist oxotremorine fitted, in most of the brain regions examined, with a two-site model for the muscarinic binding sites. The density of muscarinic binding sites increased with development in most regions, with different rates and onset times. It was higher by about sixfold in some areas destined to become cholinergic, such as the cortex and midbrain, than in noncholinergic areas such as the cerebellum. In other areas destined to become cholinergic, such as the hippocampus and the caudate putamen, the receptor density remained low. Average density values increased from 0.1 +/- 0.1 at 14 weeks up to 0.7 +/- 0.4 pmol/mg protein at 24 weeks. The variability in the specific activities of cholinesterase was relatively low, and extracts from different brain regions hydrolyzed from 5 to 30 nmol of [3H]acetylcholine/min/mg protein. These were mostly "true" acetylcholinesterase (EC 3.1.1.7) activities, inhibited by 10(-5) M BW284C51, with minor pseudocholinesterase (EC 3.1.1.8) activities, inhibited by 10(-5) M iso-OMPA. The enzyme from different brain regions and developmental stages displayed similar Km values toward [3H]acetylcholine (ca. 4 X 10(-4) M-1). The ontogenetic changes in cholinesterase specific activities had no unifying pattern and/or relationship to the cholinergic nature of the various brain areas. In most of the brain regions, the arbitrary ratio between the specific activity of cholinesterase and the density of muscarinic binding sites decreased with development, with average values and variability ranges of 83 +/- 50 and 19 +/- 19 at 14 and 24 weeks, respectively. Our findings suggest divergent regulation for cholinergic binding sites and cholinesterase in the fetal human brain and imply that the expression of muscarinic receptors is related to the development of cholinergic transmission, while acetylcholinesterase is also involved in other functions in the fetal human brain.

Acetylcholine↗
PubMed1986

Synthesis of plasma proteins in fetal, adult, and neoplastic human brain tissue.

The synthesis of plasma proteins directed by mRNA from human brain tissues was studied by combining in vitro or in ovo translation of mRNAs with crossed immunoelectrophoresis of the mRNA-directed labeled polypeptides, followed by autoradiography of the washed plates. Poly(A)-containing mRNA was prepared from different developmental stages of fetal and postnatal human brain and also from primary glioblastomas and meningiomas. Several plasma protein-like polypeptides were identified in the autoradiographs by their migration coordinates in the two-dimensional gels, compared with immunoprecipitates formed by mature, unlabeled, stainable proteins. These included polypeptides migrating like Gc globulin, haptoglobin, fibrinogen, alpha-fetoprotein, transferrin, cholinesterase, and alpha 2-macroglobulin; other, yet unidentified plasma proteins, were also observed. In general, the synthesis of these plasma proteins appeared to be more pronounced in fetal and neoplastic brain tissues than in postnatal tissues. However, clear immunoprecipitates for some of these plasma proteins could also be detected in products directed by mRNA from particular regions of mature, normal brains, indicating that some synthesis of plasma proteins takes place in the human brain even as late as 40 years of age. mRNAs for several proteins were also identified in samples of neoplastic brain. mRNA for transferrin was identified in normal fetal and adult brain but not in either the glioblastomas or meningiomas studied. Microinjected Xenopus oocytes, in which post-translational processing occurs as well, were also used to translate fetal brain mRNA. Several plasma proteins could be detected in the translation products which were induced and stored in the oocytes. These included hemopexin, which could not be detected in the in vitro system. Others, such as cholinesterase, were found to be secreted by the oocytes. These findings indicate that different cell types in the human brain may produce and either store or secrete particular plasma proteins at defined stages in their development.

Animals↗
PubMed1986

Lymphocyte subsets in habitual abortion.

Lymphocyte subpopulations were characterized by means of monoclonal antibodies in 25 women with habitual abortion and 21 multiparous normal women. Compared to nonpregnant women (N = 8), pregnant normal women were associated with significantly lower helper-to-suppressor ratios (1.71 +/- 0.41 versus 2.37 +/- 0.66). In contrast in pregnant women with habitual abortion (N = 13) the ratio remained high (2.32 +/- 0.73). Failure to increase the number of suppressors and a significant rise in helpers caused this increased ratio. We discuss the possible mechanisms and etiological importance of this finding in habitual abortion.

Abortion, Habitual↗
PubMed1986

The psychomotor development of full term infants whose mothers were treated with glucocorticosteroids during pregnancy.

The Development Quotient (D.Q.) was tested in 48 full term infants at the ages of 12-24 months who had been treated antenatally with Betamethasone to hasten pulmonary maturity. The results were compared with a control group of 100 normal full term infants of the same age. Although the two groups differed with respect to gestational age, there were no differences in birth weight, Apgar score and method of delivery between them. The results of the D.Q. evaluation showed no significant difference between the two groups. The assumption is made, therefore, that antenatal treatment with Glucocorticosteroids in the second and third trimester does not adversely affect the infant's psychological and motor development.

Betamethasone↗
PubMed1986

Heparin-induced thrombocytopenia and recurrent thrombosis in pregnancy. A case report.

Heparin-induced thrombocytopenia with thromboembolism calls for an immediate substitution of the heparin with other potent anticoagulants, such as coumarin derivatives. The occurrence of this adverse effect in pregnancy poses an additional dilemma because the use of coumarin derivatives is not acceptable during pregnancy, while other medications may not be as effective. In a pregnant patient treated with mucous sodium heparin for deep vein thrombosis, recurrent heparin-induced thrombosis and disseminated intravascular coagulation (DIC) occurred. Replacing the heparin with a different brand of the same drug resulted in reversal of the DIC and in clinical improvement. If severe heparin-induced thrombosis occurs in a patient in whom anticoagulation with other drugs is contraindicated, substituting one brand of heparin for another could be of value.

Adult↗
PubMed1985

Calcium-independent phosphatidylinositol response in gonadotropin-releasing-hormone-stimulated pituitary cells.

This paper describes the effect of gonadotropin-releasing hormone (GnRH, gonadoliberin) on phospholipid metabolism in cultured rat pituitary cells. The cells were incubated with [32P]Pi to label endogenous phospholipids (10-60 min) and then stimulated with GnRH for up to 60 min. Cellular phospholipids were separated by two-dimensional t.l.c. and the radioactivity was determined. Phosphatidylinositol (PI), a minor constituent of cellular phospholipids (7.7%), was the major labelled phospholipid, accounting for 45% of the total radioactivity, at early periods after pulse labelling. On the other hand, phosphatidylcholine, the major cellular phospholipid (37%), was labelled only to 32% of the total radioactivity. The remaining label was distributed among phosphatidylethanolamine (4.2%), cardiolipin (3.4%), phosphatidic acid (PA, 2.5%), and phosphatidylserine (1.8%). GnRH doubled 32P labelling of PA and PI significantly at 1 and 5 min of incubation respectively in the presence or absence of extracellular Ca2+. Labelling of other phospholipids was not affected by GnRH treatment. The half-maximal stimulating dose (ED50) for PI labelling and lutropin release was 0.75 nM and 0.5 nM respectively, and the stimulatory effect was blocked by the potent GnRH antagonist [D-Glp1,pClPhe2,D-Trp3,6]GnRH. GnRH-stimulated PA and PI labelling could not be demonstrated after 1 and 45 min of incubation respectively, or when the prelabelling was conducted for 60 min rather than 10 min. These results suggest heterogeneous compartmentalization of gonadotroph PA and PI pools and that increased PI turnover might be a transducing signal for Ca2+ gating that follows gonadotroph GnRH-receptor activation.

Animals↗
PubMed1985

Characterization of pituitary calcium-activated, phospholipid-dependent protein kinase: redistribution by gonadotropin-releasing hormone.

We report the presence in the rat pituitary of a calcium-activated, phospholipid-dependent protein kinase (C kinase), originally described by Takai et al. [Takai, Y., Kishimoto, A., Iwasa, Y., Kawahara, Y., Mori, T. & Nishizuka, Y. (1979) J. Biol. Chem. 254, 3692-3695]. Enzyme activity is absolutely dependent on the simultaneous presence of Ca2+ and phospholipid--in particular, phosphatidylserine. The presence of small amounts of unsaturated diacylglycerol greatly increases the apparent affinity of the enzyme for Ca2+ and phosphatidylserine. Pituitary C kinase is mostly soluble (70%) and partly particulate (30%). Although the soluble form of the enzyme can be detected in a crude cytosol preparation, the particulate form is detectable only after solubilization and anion-exchange chromatography. Administration of a gonadotropin-releasing hormone (Gn-RH) agonist analog, [D-Ser(But)6]des-Gly10-Gn-RH-N-ethylamide, to ovariectomized rats resulted in elevated serum luteinizing hormone levels (245%) accompanied by a decrease in the cytosolic form of the enzyme (60%) and an increase in the particulate form (300%) after 5 min. This apparent activation of the particulate form seems to result from translocation of a soluble C kinase to the membrane. Several endogenous substrate proteins for C kinase ranging from 16 to 100 kDa were identified in pituitary cytosol. Pituitary C kinase might be involved in signal-transduction mechanisms in Gn-RH action, in particular, and in other hypophysiotropic hormones, in general, which operate by means of stimulation of phosphoinositide turnover during which diacylglycerol is liberated.

Animals↗
PubMed1985

Polymorphism of acetylcholinesterase in discrete regions of the developing human fetal brain.

The molecular forms and membrane association of acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) and pseudocholinesterase (acylcholine acylhydrolase, EC 3.1.1.8) were determined in the presence of protease inhibitors in dissected regions of developing human fetal brain, as compared with parallel areas from mature brain. All areas contained substantial cholinesterase activities, of which acetylcholinesterase accounted for almost all the activity. Two major forms of acetylcholinesterase activity, sedimenting at 10-11S and 4-5S, respectively, were detected on sucrose gradients and possessed similar catalytic properties, as judged by their individual Km values toward [3H]acetylcholine (ca. 4 X 10(-4) M). The ratio between these forms varied by up to four- to fivefold, both between different areas and within particular areas at various developmental stages, but reached similar values (about 5:2) in all areas of mature brain. Acetylcholinesterase activity was ca. 35-50% low-salt-soluble and 45-65% detergent-soluble in various developmental stages and brain areas, with an increase during development of the detergent-soluble fraction of the light form. In contrast, pseudocholinesterase activity was mostly low-salt-soluble and sedimented as one component of 10-11S in all areas and developmental stages. Our findings suggest noncoordinate regulation of brain acetylcholinesterase and pseudocholinesterase, and indicate that the expression of acetylcholinesterase forms within embryonic brain areas depends both on cell type composition and on development.

Acetylcholinesterase↗