Transient intracardiac thrombi in amniotic fluid embolism.
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Adult↗
Biomedical subjects
A Milwidsky
Publications and source records attributed to A Milwidsky.
Regulation of cyclooxygenase activity and progesterone production in the rat corpus luteum by inducible nitric oxide synthase.
This study explores interactions between the nitric oxide synthase (NOS) and the cyclooxygenase (COX) pathways in the regulation of progesterone production in early corpus luteum cells of rats. Nitric oxide (NO), prostaglandin E (PGE) and progesterone production was analysed in luteal cells of the rat corpus luteum exposed to inhibitors of non-specific NOS, inhibitors of inducible NOS (iNOS) and inhibitors of COX. Equine chorionic gonadotrophin (eCG)/hCG-primed rat corpus luteum cells produced NO, PGE and progesterone in a linear manner during 66 h of culture. Exposure of the cells to the non-specific NOS inhibitor, N(omega)-nitro-L-arginine (0.15 mmol l(-1)) for 48 h reduced NO, PGE and progesterone production to 21, 32 and 60% of that of the controls, respectively (P < 0.05 to P < 0.01). Another non-specific NOS inhibitor, N(omega)-methyl-L-arginine, produced similar inhibitions. Exposure of the cultured cells to S-ethylisothiourea (1 mmol l(-1)), a selective inhibitor of iNOS, suppressed the production of NO by 63%, PGE by 69% and progesterone by 48%. These findings indicate that production of PGE is regulated partly by iNOS, and that progesterone is probably regulated indirectly by the secondary changes in PGE. The addition of arachidonic acid to N(omega)-methyl-L-arginine-treated cells resulted in a significant increase in PGE and progesterone production (273 and 186%, respectively) without stimulating NO production. In contrast to the regulation exerted by the NO system on COX activity, the COX system does not modulate NO production in this model. This notion stems from the observation that the COX inhibitors acetylsalicylic acid (5 mmol l(-1)) and indomethacin (5 micromol l(-1)) suppressed PGE by 86 and 89%, respectively, and progesterone by 34 and 57%, respectively, but failed to inhibit NO production. The results from the present study indicate that iNOS-mediated NO production is involved in stimulating PGE synthesis in rat luteal cells, which may upregulate progesterone production.
Animals↗
[Prevention of perinatal group B Streptococcus disease in light of an unknown maternal carriage rate in Israel].
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Female↗
In-vitro modulation of plasminogen activator activity, prostaglandin E and nitric oxide production by interleukin-1 in pregnant mare serum gonadotrophin-primed theca-interstitial cells.
To examine the participation of the theca-interstitial (TI) compartment in cytokine modulation of ovarian function, the effects of interleukin-1beta (IL-1) on plasminogen activator (PA) activity and on prostaglandin E (PGE) and nitric oxide (NO) production were examined in cultures of pregnant mare serum gonadotrophin (PMSG)-primed rat TI cells. Exposure to IL-1 (10 ng/ml) resulted in a 25% reduction (P < 0.001) in PA activity, concurrent with a 4.6-fold increase in the ability of the corresponding conditioned media to inhibit exogenous urokinase activity. IL-1 also produced a 4.7-fold increase in PGE content and a 2.8-fold increase in NO generation. These effects of IL-1 were abolished by the IL-1 receptor antagonist, suggesting specific IL-1 receptor-mediated effects. Transforming growth factor (TGF)-beta1 (10 ng/ml) significantly attenuated the IL-1-stimulated PGE production and NO generation but did not affect the ability of IL-1 to suppress PA activity and stimulate urokinase inhibitor production. The NO synthase inhibitor N-nitro-L-arginine attenuated the IL-1-induced NO generation but had no effect on PA activity or PGE production. Thus, NO is not an obligatory mediator of IL-1 effects on plasminogen activation and PGE generation in rat ovary. The present observations attest to a pleiotropic response of PMSG-primed TI cells to IL-1, and suggest a paracrine/autocrine function for the TI compartment in ovulation and corpus luteum formation.
Animals↗
Tamoxifen exerts oestrogen-agonistic effects on proliferation and plasminogen activation, but not on gelatinase activity, glycogen metabolism and p53 protein expression, in cultures of oestrogen-responsive human endometrial adenocarcinoma cells.
To elucidate potential mechanisms involved in the increased incidence of endometrial carcinomas in tamoxifen-treated patients, we examined the in-vitro effects of tamoxifen on endometrial cancer cells. The effects of tamoxifen, alone and in combination with oestradiol, on cell proliferation, plasminogen activator (PA) activity, glycogen synthase and phosphorylase activities, p53 protein concentration, and collagenase expression were assessed in two human adenocarcinoma cell lines. These lines were the oestrogen receptor-positive (Ishikawa) cells, representing a well-differentiated endometrial adenocarcinoma, and oestrogen receptor-negative (HEC-1A) cells, derived from a poorly differentiated endometrial adenocarcinoma. Tamoxifen or oestradiol alone and their combination significantly enhanced cellular proliferation of Ishikawa but not of HEC-1A cells. Both lines produced appreciable PA activity, most of which was of the urokinase type. Tamoxifen and oestradiol stimulated this activity in Ishikawa cells but not in HEC-1A cells. The effect of oestradiol was dose-dependent in a linear fashion, while tamoxifen produced a stimulation peaking at 10(-8) M and declining at higher concentrations. Tamoxifen in combination with oestradiol exhibited a synergistic effect on proliferation and on PA activity. The response of PA extended beyond the increase in proliferation, leading to higher specific activity of PA in the tamoxifen-treated cultures. In Ishikawa cells, oestradiol also increased glycogen synthase and glycogen phosphorylase activities, while tamoxifen markedly suppressed these enzymes. Oestradiol, tamoxifen, and their combination had no apparent effect on the expression of protein p53 in Ishikawa cells, or on gelatinase activity in either Ishikawa or HEC-1A cells. The present findings imply that tamoxifen produces oestrogen-agonistic effects on cell proliferation and PA activity, and oestrogen antagonistic effects on glycogen synthase and glycogen phosphorylase activities, but fails to regulate p53 and gelatinase expression. The tamoxifen-responsive systems were only observed in oestrogen-responsive adenocarcinoma cells. Thus, only certain potential oncogenic effects of tamoxifen can be simulated in vitro, and when present, these effects are enhanced in the presence of oestradiol.
Adenocarcinoma↗
Interleukin-1-mediated stimulation of prostaglandin E production is without effect on plasminogen activator activity in human granulosa lutein cell cultures.
In continuation of earlier observations on the involvement of interleukin-1 (IL-1) in ovarian function, we examined the ability of IL-1 to modulate plasminogen activator (PA) activity and prostaglandin (PG) synthesis in human granulosa lutein cells (GLCs). Toward this goal, GLCs were obtained from women undergoing in vitro fertilization, preincubated with 10% fetal calf serum for 48 h, and subsequently cultured for 48 h in serum-free media in the absence or presence of IL-1 beta (10 ng/mL). Cellular PA activity was measured by plasminogen-dependent cleavage of the chromogenic substrate H-D-valyl-L-leucyl-L-lysine-p-nitroanilide (S-2251). Prostaglandin E (PGE) levels were assayed by conventional RIA. Exposure of GLCs to IL-1 resulted in a 50% increase in PGE production, a 33% suppression of PA activity, and a 75% increase in the ability of the corresponding conditioned media to inhibit exogenous urokinase activity. The inhibitory capacity was attributable to an IL-1-mediated increase in PA inhibitor type-1 (PAI-1) production, inasmuch as urokinase inhibition could be abolished by the administration of a polyclonal antihuman PAI-1 immunoglobulin G. IL-1 treatment had no effect on plasmin or trypsin inhibition. Exposure of GLCs to IL-1 receptor antagonist abolished the ability of IL-1 to enhance PA inhibitory activity and PGE production, thereby establishing specific IL-1 receptor-mediated effects. The ability of IL-1 to suppress PA activity and to produce PAI-1 persisted in the presence of indomethacin, a potent inhibitor of PG synthesis. Likewise, transforming growth factor-beta 1 suppressed the ability of IL-1 to stimulate PGE production without affecting the IL-1-induced effects on the PA system. The present findings suggest a pluripotent response of GLCs to IL-1, characterized by the induction of PAI-1 and the suppression of PA occurring concurrent with, but independent of, PG production. These observations support the potential involvement of IL-1 in the regulation of human ovulatory processes.
Amino Acid Sequence↗
Cytokine-mediated regulation of rat ovarian function: interleukin-1 inhibits plasminogen activator activity through the induction of plasminogen activator inhibitor-1 (PAI-1).
Intraovarian IL-1 has recently been implicated as a mediator in the ovulatory process. Since PA activation is an established component of the ovulatory cascade, consideration was given in this report to the possibility that IL-1 may modulate ovarian PA economy. Whole ovarian dispersates from immature rats (25-27-days-old) were cultured under serum-free conditions for 48 h in the absence or presence of IL-1beta. Cellular PA activity was measured by plasminogen-dependent cleavage of 14C-labeled globin. Cells grown in the absence of IL-1 exhibited appreciable PA activity, as assessed by the cleavage of 0.074 +/- 0.026 mg [14C]-globin/5 x 10(5) cells (mean +/- SD). Exposure to IL-1 (10 ng/ml) led to a 30% reduction in cell-associated PA activity (p < 0.001). The IL-1-mediated inhibition occurred concurrently with a 10-fold increase in the ability of the corresponding conditioned media to inhibit exogenous urokinase activity. At similar cell densities of 5 x 10(5) cells/well, isolated cultures of theca and granulosa cells exhibited comparable PA activity in the absence of IL-1. However, only theca cells responded to IL-1 with inhibition of plasminogen activation and enhancement of urokinase inhibitory activity. Granulosa cells in turn failed to respond to IL-1. Both the inhibition of PA activity and the increase in urokinase inhibitory activity proved cell-density- and IL-1 dose-dependent. The IL-1-induced inhibition of urokinase was abolished by the administration of a polyclonal anti-rat PAI-1 IgG. Both effects of IL-1 were counteracted in a dose-dependent fashion by the soluble IL-1 receptor (which specifically complexes with IL-1), and by a highly-specific IL-1 receptor antagonist suggesting that the IL-1 effects are receptor-mediated. The present observations indicate that ovarian PA activity is subject to inhibition by IL-1 probably by way of PAI-1 of theca-interstitial origin. Inasmuch as IL-1 may be involved in initiating and maintaining the preovulatory cascade, the periovulatory activation of plasminogen must be accomplished by agents other than IL-1.
Animals↗
Direct stimulation of urokinase, plasmin, and collagenase by meperidine: a possible mechanism for the ability of meperidine to enhance cervical effacement and dilation.
Current hypotheses suggest that the degradation of cervical collagen and elastin leads to cervical effacement and dilation during labor. The collagenolytic activity is thought to be initiated through the conversion of latent (pro)collagenase to active collagenase by the plasmin formed from plasminogen or by other proteases similarly formed from their inactive zymogens. We presently demonstrate that meperidine stimulates the activity of several enzymes in the proteolytic cascade leading toward proteolysis of connective tissue proteins. Meperidine in its therapeutic concentration range produces a 26% stimulation of urokinase activity on substrate S-2444, a 39% stimulation of plasmin activity on substrate S-2551, and a 33% stimulation of collagenase activity on 14C-labeled globin substrate. These direct effects on the enzyme activities are noted in vitro with the purified enzymes and were confirmed with several small molecular weight chromogenic substrates and with 14C-globin protein substrate. Oxytocin at levels found during active labor fails to stimulate the in vitro activity of purified urokinase, plasmin, collagenase, trypsin, or tissue-type plasminogen activator. The effect of meperidine on the proteolytic enzymes suggests that its ability to promote cervical effacement and distention during labor may be at least partially due to a meperidine-induced stimulation of cervical proteases.
Cervix Uteri↗
Cytokine-mediated regulation of rat ovarian function: interleukin-1 stimulates the accumulation of a 92-kilodalton gelatinase.
It is known that the mammalian ovary possesses a complete interleukin-1 (IL-1) system replete with ligands, receptors, and a receptor antagonist. To further assess the hypothesis that IL-1 may play an intermediary role in gonadotropin-triggered ovulation, we have set out to determine whether IL-1 is capable of promoting ovarian collagenase biosynthesis, an established component of the ovulatory cascade. Untreated cultured whole ovarian dispersates from immature (25 day old) rats constitutively elaborated several collagenolytic species as assessed in a gelatin matrix. A major 72 kilodalton (kDa) gelatinase (GL) was particularly apparent. Treatment with IL-1 beta produced selective dose- and cell density-dependent increments in the accumulation of a 92-kDa GL species. Administration of an IL-1 receptor antagonist neutralized the IL-1-induced stimulation of the 92-kDa GL in a dose-dependent fashion thereby supporting the presumption that the IL-1 effect is receptor mediated. Studies of comparable cellular densities of granulosa or enriched theca-interstitial cultures demonstrated the IL-1 induced 92-kDa GL to be highly expressed in the enriched theca-interstitial but not in the isolated granulosa cell preparations. Treatment with transforming growth factor-beta 1, a putative regulator of IL-1 action, significantly attenuated IL-1-induced 92-kDa GL accumulation thereby suggesting a potential regulatory paracrine/autocrine role for this agent in ovarian gelatinase economy. Initial characterization revealed the 92-kDa GL species to be a metalloproteinase present in its proenzyme zymogenic form. Taken together, our present findings reveal the ovarian expression of a constitutive 72-kDa GL and of an IL-1-stimulated 92-kDa GL the accumulation of which is particularly marked in enriched theca-interstitial preparations. These observations, along with the demonstration of the gonadotropin-dependent preovulatory induction of ovarian IL-1 gene expression, provide strong indirect support for the view that IL-1 may be the centerpiece of an intraovarian regulatory loop concerned with the promotion of the ovulatory cascade.
Animals↗
Gonadotropin-mediated inhibition of proteolytic enzymes produced by human trophoblast in culture.
We investigated the effect of gonadotropins on protease that were suggested to be implicated in the invasive activity of the trophoblast. hCG levels ranging from 10 x 10(3) to 333 x 10(3) IU/L produced a dose-dependent inhibition of the in vitro globinolytic activity of the purified proteases trypsin, chymotrypsin, and urokinase, but failed to inhibit plasmin, collagenase, elastase, and tissue-type plasminogen activator. Likewise, FSH inhibited purified trypsin and urokinase, but not plasmin or tissue-type plasminogen activator. Culture medium conditioned with human trophoblast displayed serine protease and urokinase-like activities; exposure of the cultured trophoblast to exogenous hCG markedly suppressed serine protease and urokinase activities in the conditioned medium. A short treatment of the conditioned medium with trypsin abolished the hCG-mediated inhibition of urokinase activity. The present findings offer an explanation for earlier observations that hCG reduced collagenase activity in trophoblasts without affecting the level of collagenase-specific mRNA. The present results are also consistent with the concept that hCG, by its direct ability to inhibit certain serine proteases and urokinase in trophoblast, suppresses a protease-mediated conversion of procollagenase to active collagenase. The ability of hCG to prevent initiation of the collagenolytic cascade suggests that gonadotropins may regulate the transient invasive activity of the trophoblast.
Aprotinin↗
High levels of human chorionic gonadotropin retard first trimester trophoblast invasion in vitro by decreasing urokinase plasminogen activator and collagenase activities.
Trophoblast cells of the blastocyst and of the first trimester placenta penetrate the endometrial basement membrane during the process of implantation and placental development. However, this invasive capacity seems to be restricted to the fetomaternal interface, as few trophoblast cells can be identified in the decidua, and trophoblasts rarely penetrate the maternal blood vessels. We have shown that the high invasive ability of first trimester human trophoblasts in vitro depends on collagenase activated by plasmin generation. In our study we used invasive first trimester trophoblast cells in conjunction with as in vitro amnion invasion assay to assess the role of hCG in the invasive process. hCG inhibited trophoblast invasion capacity in a dose-dependent fashion but exerted no effect on the ability of the trophoblasts to attach to the basement membrane. The activity of collagenase by trophoblasts (determined by zymography) was down-regulated by hCG, again in a dose-dependent manner. In contrast, hCG had no effect on production of the tissue inhibitor of metalloproteinases. Similar inhibitory effects of hCG on urokinase-plasminogen activator (uPA) and the activity of trophoblast-conditioned media were shown (measured by degradation of S-2444). The hCG effect on collagenase production was not mediated by the expression of procollagenase messenger RNA (mRNA), the expression of the mRNA encoding tissue inhibitor of metalloproteinase, or the expression of uPA mRNA, suggesting posttranscriptional control of hCG action. High levels of hCG attenuated the activity of commercial uPA but had no effect on commercial collagenase activity. These observations suggest that hCG may play a role in the trophoblast invasion process by inhibition of uPA activity, in turn decreasing collagenase activity and thereby reducing trophoblast cell invasion.
Cell Adhesion↗
Gallstones in an ovarian dermoid cyst.
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Cholecystectomy↗
Primary fibrinogenolysis complicating second trimester placental separation.
We present a case of second trimester placental separation complicated by severe bleeding diathesis. Primary fibrinogenolysis is suggested as the cause of the coagulopathy.
Adult↗
Direct inhibition of proteases and cervical plasminogen activator by antibiotics.
OBJECTIVES: Preterm premature rupture of the fetal membranes and premature delivery are sometimes linked to genital tract infection and activation of proteolytic enzymes that degrade the extracellular matrix. The possible beneficial effect of antibiotics in prevention of preterm premature rupture of fetal membranes and retardation of the onset of labor in some patients with clinical or subclinical infection was explained via their antibacterial efficacy. The aim of this study was to determine the effect of antibiotics on proteolytic enzymes as a possible explanation for the ability of antibiotics to retard preterm labor. STUDY DESIGN: The direct effect of four antibiotics on the proteolytic activities of purified collagenase, elastase, plasmin, trypsin, and chymotrypsin and on streptokinase and human cervical plasminogen activator was measured. RESULTS: The macrolide antibiotic erythromycin and the beta-lactam antibiotics penicillin G, cloxacillin, and ampicillin exerted, in most of the tested combinations with the different proteases, inhibitory effects on the proteolytic activities. CONCLUSION: The present finding that antibiotics directly inhibit proteases may offer an explanation for the beneficial response to antibiotic therapy in some cases of idiopathic preterm labor even in absence of pathogenic bacterial infection.
Ampicillin↗
Third trimester torsion of persistent ovarian cyst following ovarian hyperstimulation--an unusual cause of preterm labor.
Herein, a patient being operated for cesarean section due to preterm labor in the 31st week of a triplet pregnancy induced by gonadotropins is being described. On celiotomy, peritoneal effusion was present secondary to torsion of a 10 x 6 cm right ovarian cyst. This uncommon finding contradicts the common belief that the chances for an ovarian cyst in the overcrowded peritoneal space due to a 40-week-size uterus to twist around its pedicle are remote. The possibility that preterm labor was initiated by the torsion is discussed.
Adult↗
Stimulation of plasmin activity by aspirin.
This study demonstrates an enhancing effect of aspirin on the amidolytic activity of plasmin. The stimulation of plasmin by aspirin was concentration-dependent and was attained at aspirin concentrations above 2 x 10(-4) M. Aspirin produced a small, reproducible and statistically significant stimulation of the chromogenic activity of plasmin upon H-D-Valyl-L-Leucyl-L-Lysine-p-nitroanilide (S-2251) or pyro-Glu-Gly-Arg-p-nitroanilide (S-2444). Kinetic analysis demonstrated a slight decrease in the affinity of plasmin for substrate S-2251 in the presence of aspirin, reflected by a change of the Km from 3.2 x 10(-4) M to 3.8 x 10(-4) M, and an increase of the Vm. The reciprocal Lineweaver-Burk curve indicated an uncompetitive type of stimulation. The stimulatory effect of aspirin was abolished by the lysine analogue 6-aminohexanoic acid (AHA) but not by the alpha-amino acid glutamic acid. The effect of AHA suggests a specific involvement of lysine binding sites (LBS) on plasmin in the interaction of the enzyme with aspirin. Transient acidification of plasmin abolished its response to aspirin, to AHA and to their combination. The addition of aspirin to diluted human control or pregnancy plasma in vitro stimulated the plasma-mediated cleavage of the chromogenic substrate S-2251. In contrast to its effect on plasmin, aspirin failed to change the activity of tissue-type or urokinase-type plasminogen activators. It is conceivable that in addition to the antithrombotic effect of aspirin ascribed to its interaction with the platelets, aspirin also directly stimulates plasmin activity.
Amino Acid Sequence↗
Secondary biosynthetic defects in women with late-onset congenital adrenal hyperplasia.
BACKGROUND AND METHODS: Late-onset (non-classic) congenital adrenal hyperplasia is a cause of hirsutism, menstrual disorders, and infertility, but its frequency and the patterns of abnormalities in adrenal hormone secretion are not well understood. We investigated the frequency and ethnic distribution of nonclassic congenital adrenal hyperplasia due to deficiencies of 3 beta-hydroxy-delta 5-steroid dehydrogenase, 21-hydroxylase, or 11 beta-hydroxylase among 170 Israeli Jewish women with these clinical problems. All enzyme defects were identified by comparing the patients' hormonal responses to a 0.25-mg intravenous bolus dose of alpha 1-24-ACTH with those of 26 age-matched normal women. RESULTS: Twenty women (12 percent) had 3 beta-hydroxy-delta 5-steroid dehydrogenase deficiency, 18 (10 percent) 21-hydroxylase deficiency (14 homozygous), and 14 (8 percent) 11 beta-hydroxylase deficiency. All the homozygous women with 21-hydroxylase deficiency also had evidence of a partial deficiency in 11 beta-hydroxylase activity. Similarly, most of the women with 11 beta-hydroxylase deficiency also had evidence of a deficiency in 3 beta-hydroxy-delta 5-steroid dehydrogenase. Among the 118 women with no adrenal biosynthetic defect, 38 had high plasma androgen concentrations, and 80 had normal concentrations. CONCLUSIONS: About one third of Israeli Jewish women with hirsutism, menstrual disorders, or unexplained infertility had nonclassic congenital adrenal hyperplasia. Secondary adrenal biosynthetic defects were frequent in these women and were probably caused by intra-adrenal androgen excess rather than by dual inherited enzymatic deficiencies.
3-Hydroxysteroid Dehydrogenases↗