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At least 505 records · Page 28Linked to original sources
PubMed1985

Polymorphism of placental phosphoglucomutase in Japanese.

Polymorphism of PGM1 and PGM3 types was investigated in placental extracts from 127 unrelated Japanese parturients living in Yamanashi Prefecture. The gene frequencies were 0.787 for PGM1(1), 0.213 for PGM1(2); 0.760 for PGM13, 0.240 for PGM3(2), respectively. There was no significant association between the PGM1 and PGM3 systems. The PGM3(2) frequency in the present sample population was higher than those in Kanto District, but lower than those in Kinki District.

Electrophoresis, Starch Gel↗
PubMed1991

Characterization of a factor(s) from partially purified human gonadotrophin preparations which inhibit(s) the binding of radiolabelled human LH and human chorionic gonadotrophin to Candida albicans.

We have shown previously that partially purified human chorionic gonadotrophin (hCG) preparations inhibited the specific binding of 125I-labelled hLH or hCG to Candida albicans membranes at much lower concentrations than did highly purified hLH or hCG preparations. We now describe the characterization and partial purification of a heat-labile glycoprotein from commercially available gonadotrophin preparations. The factor strongly inhibited LH binding to Candida membranes, but not to sheep or pig luteal LH receptors. This material had a molecular weight of 16,000-21,000 daltons, bound strongly to CM-Sepharose at physiological pH, and could be resolved completely from hCG and from epidermal growth factor-like factors present in commercial gonadotrophin preparations. Its activity was not attenuated by a range of inhibitors specific for the four major classes of proteolytic enzymes, nor did it inhibit hormone binding by causing degradation of 125I-labelled hLH or hCG tracers. Factors which inhibited hLH binding to Candida membranes were also present in partially purified human urinary and equine serum gonadotrophin preparations and in placental extracts, but were not detected in highly purified CG of hLH preparations. The properties of this factor were similar to those described for beta-core protein, a cleavage product of the beta subunit of hCG which is a contaminant of commercial gonadotrophin preparations. Highly purified beta-core protein inhibited 125I-labelled hLH binding to Candida membranes, but not to sheep luteal binding sites. Preparations of hCG depleted of inhibitor activity could stimulate adenylate cyclase activity in Candida membranes almost five fold. In contrast, partially purified inhibitor preparations strongly inhibited basal adenylate cyclase activity (to 18% of control levels). These observations suggest that endogenous LH-like factors, perhaps similar to beta-core proteins of hCG, may play a role in the regulation of morphogenesis in Candida species.

Adenylyl Cyclases↗
PubMed1988

Foetoplacental drug clearance in the rabbit: studies with trimazosin, acebutolol and tolmesoxide.

1. An animal model suitable for studying placental extraction of large numbers of drugs without the need for major surgical facilities, has been developed in the anaesthetized New Zealand white rabbit with sampling of both arterial and venous blood of the foetoplacental unit. 2. Three drugs with different routes of metabolism were studied: trimazosin, tolmesoxide and acebutolol. There was no extraction across the foetoplacental unit. 3. The clearance of acebutolol differed significantly in rabbits from different suppliers. 4. These results do not suggest a role for the placenta in drug metabolism. They do, however, suggest a previously undescribed genetic determinant of acebutolol metabolism.

Acebutolol↗
PubMed1980

Detection of macaque chorionic gonadotropin in the placenta of the cynomolgus monkey (Macaca Fascicularis).

The biologically detectable period of macaque chorionic gonadotropin (mCG) was estimated by the mouse uterine weight method with 22 placentas of the cynomolgus monkey at various pregnancy stages. The hormone was detectable in the placental extracts of the 4th and 5th week of gestation, but not in those of the 6th week or later. This fact may be compatible with our previous finding that mCG was not detectable in urine after the 6th week of gestation in the cynomolgus monkey.

Animals↗
PubMed2000

[N-acetyl-beta-glucosaminidase (NAG) activity in parturients with placental insufficiency in postmature pregnancy and with EPH-gestosis].

NAG activity evaluation was carried out in parturients' blood and placental homogenates in regular pregnancies (n = 46) and complicated with biological postmaturity (n = 30) and EPH-gestosis (n = 24). It was revealed that in the blood of parturients with pregnancy complicated with gestosis there was considerable increase of NAG activity (2.43 +/- 1.02 microKat/kg). Lower activity level was found in parturients with entopic pregnancy (1.93 +/- 0.87 microKat/kg), and the lowest in those with postmature pregnancy (1.78 +/- 0.56 microKat/kg). The placental homogenates presented statistically significant differences--the highest in postmature pregnancy (6.37 +/- 2.01 mKat/kg), lower in pregnancy complicated with gestosis (4.85 +/- 1.52 mKat/kg) and the lowest in normal pregnancy (3.52 +/- 1.21 mKat/kg). The elevated activity in blood serum of parturient with gestosis may indicate kidney damage in the course of disease. High activity in homogenate may indicate the processes of placental degradation in postmature pregnancy. There is no evidence of correlation between NAG activity in blood and activity in placental tissue.

Acetylglucosaminidase↗
PubMed1975

[Pregnancy in teenagers (author's transl)].

In this study pregnancy, delivery and the newborn infant of 151 juvenile primiparas and 1034 adolescent primiparas were analyzed and were compared with a group of 3563 primiparas 21, 23 and 25 years of age. Regarding the obstetric history and the intrapartum period there was no increase incidence of complications among the young patients, however we found among the older women an increase in the incidence of operative deliveries. In the postpartum period it was noted that the young primiparas had a higher incidence of postpartum bleeding caused by atonia of the uterus and also an increased incidence of placental complications with a high rate of manual placental extraction and curettages. A positive correlation was found between premature birth and perinatal mortality and the younger the age of the mother. The newborn of the young mothers was also lighter and shorter at birth and had a higher incidence of malformations. This study has shown, that juvenile expectant mothers are a risk group for obstetricians and pediatricians.

Adolescent↗
PubMed1975

[On the beginnings of hormonal contraception (author's transl)].

The possibility of hormonal contraception was postulated as early as 1919 by the physiologist Ludwig Haberlandt in Innsbruck. The same year, he began to test his hypothesis in animal experiments. In 1924 he succeeded in his efforts to render mice infertil by orally administering ovarian and placental extracts. He failed to have his method tried in women.

Animals↗
PubMed1975

Placental acid hydrolase purification on concanavalin A-sepharose.

Crude human placental extract was chromatographed on concanavalin A-Sepharose. Using a single procedure, 20- to over 300-fold purification of six acid glycohydrolases was achieved, in most cases with a good yield. Improved yield of individual enzymes could be achieved by modifications of the method of elution. The capacity of concanavalin A-Sepharose to bind glycohydrolases from placenta was very large, and will provice a useful procedure for the large-scale purification of the human enzymes.

Chromatography↗
PubMed2005

Active management of the third stage of labor among American Indian women.

OBJECTIVE: This study's objective was to judge whether active management of the third stage of labor is as effective in reducing maternal blood loss among rural American Indian women as in randomized trials. METHODS: We collected retrospective data on a cohort of largely multiparous American Indian women having singleton vaginal births at a rural hospital in 2000-2001, comparing measures of blood loss among women receiving active (n=62) versus routine (n=113) management of the third stage of labor. Outcomes included both objective (postpartum hemoglobin decline) and subjective (estimated blood loss) measures of maternal blood loss. RESULTS: Active management was associated with reduced maternal blood loss on several measures when compared to routine management, including incidence of a 3 g/dl or greater postpartum hemoglobin decline (5% versus 27%), mean postpartum hemoglobin decline (1.7 versus 2.2 g/dl), and mean estimated blood loss (355 versus 430 ml). Compared to women who received routine management, women who received active management had 87% reduced odds of a 3 g/dl or greater postpartum hemoglobin decline after adjusting for preeclampsia, manual placental extraction, laceration repair, and maternal age. CONCLUSIONS: Our findings suggest that active management of the third stage is as effective in reducing maternal blood loss among rural American Indian women as in randomized trials in maternity hospitals.

Adult↗
PubMed1990

Purification and functional characterization of integrin alpha v beta 5. An adhesion receptor for vitronectin.

We have purified a novel member of the integrin gene family from placenta that serves as a vitronectin receptor. This integrin is composed of the alpha v subunit and a beta subunit that we designate beta 5. Purification was accomplished by immunodepleting a placental extract of integrin alpha v beta 3, allowing us to purify alpha v beta 5 from the remaining extract by monoclonal antibody affinity chromatography on LM 142-Sepharose, which binds to the alpha v subunit. Purification to homogeneity was subsequently achieved by affinity chromatography on wheat germ lectin-Sepharose. Western blot analysis with antibodies raised against alpha v beta 5 and alpha v beta 3 demonstrated that beta 3 and beta 5 were distinct but confirmed that the alpha subunit of the two integrins were immunologically identical. Similarly, antibodies that bind beta 3 proximal to the ligand-binding site failed to react with beta 5, indicating an architectural difference at the ligand-binding site of these related integrins. This structural difference apparently results in a functional distinction, since purified alpha v beta 3 bound to vitronectin, fibrinogen, von Willebrand factor, and fibronectin, whereas integrin alpha v beta 5 bound preferentially to vitronectin. Finally, we demonstrate by three criteria that beta 5 and beta x, the latter of which was identified in lung carcinoma cells (Cheresh, D. A., Smith, J. W., Cooper, H. M., and Quaranta, V. (1989) Cell 57, 59-69), are identical. First, peptide maps of beta x and beta 5 are identical. Secondly, polyclonal antibodies raised against alpha v beta 5 immunoprecipitate both beta 5 and beta x, and finally, the amino-terminal amino acid sequences of beta x and beta 5 are identical.

Amino Acid Sequence↗
PubMed1991

Radioimmunoassay of inhibin based on synthetic human inhibin alpha-chain peptide.

Polyclonal rabbit antisera were produced against cyclic human inhibin [(Cys6, Tyr7) alpha-(6-30)NH2] peptide, covalently conjugated to bovine serum albumin. The tyrosine residue introduced at position 7 facilitated the oxidative incorporation of radiolabel (125I) to yield a tracer with specific activity of 73.9 Ci/g. These reagents were used to develop a homologous equilibrium radioimmunoassay for human inhibin, with polyethylene glycol, 200 g/L, serving as the separation phase. At a detection limit of 2 micrograms/L (n = 7), immunoactive inhibin was detectable in human pre-ovulatory follicular fluid (128 micrograms/L), seminal plasma (2374 micrograms/L), amniotic fluid (66 micrograms/L), and placental extract (347 micrograms/L). We also demonstrated inhibin immunoreactivity in biological fluids from other mammalian species: macaque, chimpanzee, porcine, and bovine, but not rodent (guinea pig). Although the antisera were raised against a nonbioactive inhibin peptide, immunoglobulins fractionated on Protein A-Sepharose neutralized the bioactivity of human ovarian inhibin. Further characterization of inhibin immuno- and bioactivity was undertaken with immobilized heparin, divalent metal cations, and dye ligands. Only heparin-Sepharose distinguished between immuno- and bioactive inhibin.

Amniotic Fluid↗
PubMed1990

Purification, characterization, and western blot analysis of human GTPase-activating protein from native and recombinant sources.

Human ras GTPase-activating protein (GAP) is a cytoplasmic factor that stimulates the GTPase activity of normal N-ras p21 while having no stimulatory effect on the GTPase activity of oncogenic variants of N-ras p21. We have purified two forms of native ras GAP from human placental tissue. In addition to the Mr = 120,000 type I GAP reported previously (1), an equivalent amount of an Mr = 95,000 molecule with GAP activity was recovered and shown to have the N-terminal sequence expected for type II GAP. The two GAP forms in placental extracts were resolved by molecular sieve chromatography and appeared to have a monomeric native structure. Human recombinant type I GAP was produced intracellularly in Sf9 insect cells using a baculovirus expression vector, and 10-mg quantities were purified to homogeneity in three steps. Comparison of the purified native and recombinant GAP molecules revealed that all three displayed similar biological specific activities in an in vitro GAP assay. A polyclonal antibody to purified recombinant GAP was prepared and shown to neutralize the activity of both native and recombinant GAPs. The antibody was also highly specific for the detection of native GAP by Western blot. Type I and II GAP species were detected in approximately equal amounts in cytoplasmic extracts of human placenta, but only type I GAP was observed when other human tissues were examined.

Amino Acid Sequence↗
PubMedDate not supplied

Transfer characteristics of triamterene and its analogs. Central nervous system, placenta, and kidney.

Earlier in vivo studies revealed a low concentration of triamterene in the brain of guinea pigs and baboons, and a transfer of the drug from the fetus to the mother. Additional investigations have been performed to characterize further the transport system(s) for triamterene in the central nervous system (CNS), placenta, and kidney. In guinea pigs a very low brain to free plasma concentration ratio (0.1) was achieved 3.5 min after drug administration and was maintained during 180 min of drug infusion. The cerebrospinal fluid (CSF) concentration was similar to the concentration of the drug in the brain. A higher brain to free plasma concentration ratio was gradually reached in dogs studied with nanogram per ml and microgram per ml concentrations of triamterene in CSF. Administration of triamterene to fetal and maternal sheep revealed a placental extraction (E) from fetal plasma to placenta 20 times greater than that from maternal plasma to placenta. The E from fetal plasma to placenta was unaffected by a triamterene concentration in the maternal circulation 10 times that in the fetus. These findings and studies of renal clearance support an active transfer of triamterene by the CNS, placenta, and kidney; the physiologic substrate for these systems is unknown.

Amiloride↗
PubMed1989

Expression of merosin, a tissue-specific basement membrane protein, in the intermediate trophoblast cells of choriocarcinoma and placenta.

Merosin is a novel tissue-specific basement membrane-associated protein found in basement membranes of trophoblast, striated muscle and Schwann cells. In placental extracts, the immuno-reactivity for merosin was detected in a protein band of 80 kilodaltons, and a 65 kilodalton polypeptide fragment of merosin could be isolated from proteolytic digests of placenta. In the present study, we describe the expression of merosin in human choriocarcinomas and normal placentas using immunoperoxidase staining of paraffin-embedded tissues. All five choriocarcinomas studied show immunoreactivity for merosin. Tumor cells, exhibiting the morphology typical of the intermediate trophoblast, stained distinctly for merosin. The cytotrophoblast and syncytiotrophoblast cells in these tumors showed negligible or no staining. In second and third trimester human placentas, merosin immunoreactivity was found in large extravillar mononuclear trophoblast cells of the basal plate as well as in the trophoblast basement membranes of the chorionic villi. The results indicate that merosin is mainly expressed in the intermediate trophoblast cells of both neoplastic and normal origin, whereas almost no expression is seen in cytotrophoblast and syncytiotrophoblast. Consequently, it is suggested that the intermediate trophoblast may represent a third, independently differentiated trophoblastic cell type.

Antibodies, Monoclonal↗
PubMedDate not supplied

[The identification and partial characterization of merosin--a new specific protein of the basement membranes of certain tissues].

A tissue-specific basement membrane-associated protein has been identified by the use of monoclonal antibodies prepared against a protein fraction of human placenta. In frozen sections of human tissues the monoclonal antibodies decorated basement membranes of Schwann cells, striated muscle, and trophoblast. In antibody-affinity chromatography of limited pepsin digests of human placenta, a 65-kDa polypeptide was bound by the monoclonal antibodies. Polyclonal antisera and new monoclonal antibodies were raised against the isolated 65-kDa polypeptide, and they stained human tissues identically to the original monoclonal antibodies. An 80-kDa polypeptide was detected by these antibodies in placental extracts prepared without proteolysis. The 65-kDa and 80-kDa polypeptides were immunologically distinct from laminin, type IV collagen, fibronectin and major serum proteins. These polypeptides are presumably derived from a novel basement membrane-associated protein which we named merosin. Several cDNA clones were isolated which code for a protein specifically recognized by polyclonal antibodies to the 65-kDa fragment. In developing mouse tissues, merosin was first detected at the newborn stage. The restricted tissue distribution and the late development appearance of merosin suggest that the protein has a tissue-specific function in highly differentiated cells.

Animals↗
PubMed1989

[Free and sulfoconjugated plasma catecholamines in premature infants and mature newborn infants after birth].

Sulfate conjugation represents a major pathway for the inactivation of free catecholamines. We investigated the ability of newborns to protect the body against an overflow of free catecholamines by sulfoconjugation. No difference of free catecholamines in the umbilical artery was found in preterm and term newborns. Furthermore, preterm and term newborns were able to form sulfoconjugated catecholamines. In term newborns, but not in preterm newborns, there was a significant relationship between free catecholamines and their respective sulfoconjugated forms (p less than 0.001). In comparison to term infants sulfoconjugated dopamine and norepinephrine were significantly decreased in preterm newborns, although the placental extraction rates of these catecholamines were markedly lower in preterm infants. This favors the conclusion, that synthesis rather than increased degradation may be responsible for the low levels of sulfoconjugated catecholamines in preterm infants. Thus, preterm newborns might be less able to inactivate free catecholamines by sulfoconjugation. The clinical importance of these results concerning treatment of preterm newborns with dopamine and noradrenaline has yet to be established.

Catecholamines↗