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PubMedDate not supplied

Ventilatory accommodation of oxygen demand and respiratory water loss in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus).

We studied ventilation in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus), respectively, within the range of ambient temperatures (T(a)) from -5 degrees to 45 degrees C. At thermoneutral temperatures (Ta=25 degrees C), there were no differences between the species in respiratory frequency, tidal volume, total ventilation, or oxygen extraction. The ventilatory patterns of the kangaroos were markedly different from those predicted from the allometric equation derived for placentals. The kangaroos had low respiratory frequencies and higher tidal volumes, even when adjustment was made for their lower basal metabolism. At Ta>25 degrees C, ventilation was increased in the kangaroos to facilitate respiratory water loss, with percent oxygen extraction being markedly lowered. Ventilation was via the nares; the mouth was closed. Differences in ventilation between the two species occurred at higher temperatures, and at 45 degrees C were associated with differences in respiratory evaporative heat loss, with that of M. giganteus being higher. Panting in kangaroos occurred as a graded increase in respiratory frequency, during which tidal volume was lowered. When panting, the desert red kangaroo had larger tidal volumes and lower respiratory frequencies at equivalent T(a) than the eastern grey kangaroo, which generally inhabits mesic forests. The inference made from this pattern is that the red kangaroo has the potential to increase respiratory evaporative heat loss to a greater level.

Adaptation, Physiological↗
PubMed1998

[Serum concentration of insulin-like growth factor-I in cord blood].

OBJECTIVE: To evaluate the role of insulin-like growth factor-I (IGF-I) in fetal growth and placental growth. METHODS: Cord blood IGF-I was determined by radioimmunoassay (RIA) after serum samples were extracted with acid-ethanol. Linear correlation between variables was tested by calculating pearson's correlation coefficient. student's test was used to compare mean values between groups. RESULTS: In 102 tested samples, the concentration of cord blood serum IGF-I was correlated with the gestational age, the birth weight of neonates and placental weight (r = 0.32, P < 0.001, r = 0.68, P < 0.001, r = 0.75, P < 0.001). The mean serum level of IGF-I in the small-for-gestational-age (SGA) neonates was significantly lower than that in average-for gestational-age (AGA) (t = 4.77, P < 0.001), But the serum concentration of IGF-I in the Large-for-gestational-aga (LGA) neonates was significantly higher than that of AGA neonates (t = 7.97, P < 0.001). CONCLUSION: Those results suggested that IGF-I is an important regulator for fetal and placental growth and development. It has the key role for macrosomia and IUGR forming.

Adult↗
PubMed1992

Influence of conditioned media from bovine cotyledon tissue cultures on function of bovine neutrophils.

Bovine fetal placental (cotyledon) tissue obtained from pregnant cows on days 255, 265, and 275 of gestation, as well as immediately after parturition (n = 5) was incubated in media for 48 hours, and the incubation media were collected. Neutrophils from 4 ovariectomized nonpregnant cows were incubated for 2 hours with conditioned media from placental tissue cultures or medium (control). Immediately after incubation, the neutrophils were subjected to the following leukocyte function assays: chemotaxis against zymosan-activated serum, chemotaxis against undiluted conditioned media (only neutrophils that were incubated in medium only), random migration, ingestion of 125I-iododeoxyuridine Staphylococcus aureus (125I-IdUR-S aureus), iodination of proteins, cytochrome C reduction, and antibody-independent and -dependent cell-mediated cytotoxicity. Conditioned media from cultured cotyledon tissue was chemoattractant for bovine neutrophils, and increased chemotactic response of neutrophils against zymosan-activated serum by 13%. The following neutrophil functions were decreased: random migration by 25%, iodination of proteins by 44%, cytochrome C reduction by 13%, and antibody-dependent cell-mediated cytotoxicity by 5%. Ingestion of 125I-IdUR-S aureus and antibody-independent cell-mediated cytotoxicity were not influenced by coincubation of neutrophils and conditioned media. Time of gestation did not alter the effects of conditioned media on neutrophil function. It was concluded that chemotactic properties of cotyledon tissue extracts, as has been reported earlier, may be attributable to substances released by fetal placental tissue. Those substances might also locally or systemically influence the oxygen-dependent antimicrobial system of neutrophils, thereby causing an increased susceptibility to bacterial infections in the peripartum period.

Animals↗
PubMed1976

[Isolation and characterization of the placental proteil pp1 (author's transl)].

The purification and characterization of the placental protein PP1 is described. The protein has been isolated from an aqueous extract of human term placentae using salt and ethanol fractionation procedures, gel filtration, preparative zone electrophoresis and chromatography on hydroxylapatite. PP1 sediments with 8.4 S and has a molecular weight of 160,000 daltons; it is composed of apparently four identical subunits, which have a molecular weight of 40,000 +/- 2000 daltons and are held together by non-covalent bonds. PP1 is a glycoprotein with a carbohydrate content of 2.7% and has the electrophoretic mobility of an alpha1-globulin. Immunochemical methods were used for the detection and quantitative determination of the protein. PP1 is not found in normal plasma or in erythrocytes; neither could it be detected in sera from pregnant women nor in sera from patients suffering from malignant diseases. PP1 is a tissue protein, but not specific for the placenta; it is also found in other human tissues. The average amount of PP1 extracted from one human term placenta was determined to be around 3 mg. Immunogluorescent studies revealed that the protein is located in the cytoplasma of the syncytium as well as in the stroma of the villi.

Cytoplasm↗
PubMed1984

Studies of a melanoma tumor-associated antigen detected in the spent culture medium of a human melanoma cell line by allogeneic antibody. II. Immunobiologic characterization.

A tumor-associated antigen (TAA) was isolated from spent culture medium of human melanoma cell line UCLA-SO-M14 (M14). After radioiodination and further purification, it was used in a radioimmunoassay (RIA). When tested in RIA for anti-TAA activity, 56% (111/200) of sera from melanoma patients, 21% (21/100) of sera from sarcoma patients, and 19% (19/100) of sera from carcinoma patients, as well as 12% (6/50) sera from pregnant women and 10% (10/100) apparently normal sera, were positive. The variations (0.25-3.8 micrograms/mg total protein) in specific TAA activity in 20 different batches of spent media collected for 18 months exhibited patterns of gradual increases and decreases, suggesting a cell growth cycle-related phenomenon. Binding between the allogeneic antibody and 125I-labeled TAA was inhibited by 70% (32/47) of melanoma spent media and cells (from culture or biopsy). Conversely, only 7% (3/33) spent medium or membrane extracts of other tumor cells and 0% (1/69) of human normal, fetal, or placental cells were positive in competitive RIA. The TAA was immunologically different from normal tissue antigens, blood-group antigens, human leukocyte antigens, and microbial antigens. These immunobiologic properties of the TAA isolated from M14 spent culture medium and used in the RIA suggested that such TAA was melanoma associated.

Antibodies, Neoplasm↗
PubMed1978

Prolactin during pregnancy and lactation in the rabbit.

By using a specific heterologous double-antibody RIA, changes in the blood levels of PRL during pregnancy, pseudopregnancy, and lactation have been investigated for the first time in the rabbit. Blood levels fluctuate during early and midpregnancy in a manner similar to that in pseudopregnancy. Levels decline in the third trimester of pregnancy and increase dramatically (3- to 25-fold) at or 1--2 days before delivery. Pituitary levels of PRL showed no significant alteration, and fetal serum and amniotic fluid levels of PRL remain low (less than 10 ng/ml) throughout pregnancy. No significant PRL-like, GH-like, or placental lactogen-like activity could be demonstrated either in serum or in extracts of placenta (n = 262) taken between days 10 and 31 of pregnancy. Postpartum blood levels of PRL were similar in lactating and postpartum nonlactating females. In lactating females, suckling evoked an immediate increase (15- to 25-fold) in circulating PRL levels. Handling the female or the iv injection of oxytocin during lactation did not cause PRL release. In contrast, manual test stimulation caused an immediate increase in blood levels of PRL and a response pattern very similar to that of natural suckling. These results suggest that PRL release during suckling occurs solely in response to the tactile stimulation of the teats.

Amniotic Fluid↗
PubMed1968

Purification and properties of molecular-weight variants of human placental alkaline phosphatase.

1. Alkaline phosphatase of human placenta was purified by a procedure involving homogenization with tris buffer, pH8.6, extraction with butanol, ammonium sulphate fractionation, exposure to heat, ethanol fractionation, gel filtration, triethylaminoethylcellulose anion-exchange chromatography, continuous curtain electrophoresis on paper and equilibrium dialysis. Methods for both laboratory-scale and large-scale preparation were devised. 2. Two major molecular-weight variants designated A and B were separated by molecular sieving with Sephadex G-200 and variant A was purified 4000-fold. 3. Variant B, which comes off the Sephadex G-200 column before variant A, is the electrophoretically slower-moving species on starch gel and is quite heterogeneous. 4. Purified variant A was fairly homogeneous on the basis of electrophoretic studies on starch gel and Sephadex gel, ultracentrifugation and immunodiffusion. 5. The respective molecular weights for variants A and B were 70000 and over 200000 on the basis of sucrose-density-gradient ultracentrifugation. Variant A exhibited a sedimentation coefficient of 4.2s. 6. Crystalline variant B could be converted into fast-moving variant A and vice versa. 7. Kinetic studies indicated no difference between the two variants. These include linear rates of hydrolysis, pH optimum, Michaelis constants and uncompetitive stereospecific l-phenylalanine inhibition. 8. The amino acid compositions of variants A and B and of placental albumin were determined.

Albumins↗
PubMed2001

White button mushroom phytochemicals inhibit aromatase activity and breast cancer cell proliferation.

Estrogen is a major factor in the development of breast cancer. In situ estrogen production by aromatase/estrogen synthetase in breast cancer plays a dominant role in tumor proliferation. Because natural compounds such as flavones and isoflavones have been shown to be inhibitors of aromatase, it is thought that vegetables that contain these phytochemicals can inhibit aromatase activity and suppress breast cancer cell proliferation. Heat-stable extracts were prepared from vegetables and screened for their ability to inhibit aromatase activity in a human placental microsome assay. The white button mushroom (species Agaricus bisporus) suppressed aromatase activity dose dependently. Enzyme kinetics demonstrated mixed inhibition, suggesting the presence of multiple inhibitors or more than one inhibitory mechanism. "In cell" aromatase activity and cell proliferation were measured using MCF-7aro, an aromatase-transfected breast cancer cell line. Phytochemicals in the mushroom aqueous extract inhibited aromatase activity and proliferation of MCF-7aro cells. These results suggest that diets high in mushrooms may modulate the aromatase activity and function in chemoprevention in postmenopausal women by reducing the in situ production of estrogen.

Agaricus↗
PubMed1985

Structure of covalent insulin-receptor complexes (I-S-S-R) in isolated rat adipocytes and human placental membranes.

The structure of naturally-formed covalent disulphide-linked complexes between insulin and its receptor was examined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. To prevent destabilization of disulphide bonds at alkaline pH the standard discontinuous electrophoresis conditions were changed to a continuous buffer system at pH 7.0. 125I-insulin was first bound to either rat adipocytes or human placental membranes for 10 min at 37 degrees C. After washing, non-dissociable radioactivity was extracted from cells or membranes in Triton X-100 and immunoprecipitated with an antiserum (B-2) to the insulin receptor. Electrophoresis of the immune precipitate revealed the two smaller of the three reported species of native insulin receptor (Mr values approx. 350 000, 290 000 and 260 000); in addition, a species of Mr 200 000 was also frequently observed in adipocytes. When non-dissociable 125I-insulin was chemically crosslinked to adipocytes or placental membranes, prior to solubilization and immunoprecipitation, all three species of the native receptor were labelled; after reduction, only a single species of Mr 130000 was observed. These findings indicate that disulphide exchange of insulin occurs with the Mr 130000 (alpha) binding subunit within partially reduced species of the native, oligomeric receptor. The degree of disulphide binding of insulin could therefore depend on the relative abundance of partially reduced receptor species and on the redox state of the cell membrane.

Adipose Tissue↗
PubMed1996

Proteases and their inhibitors are indicative in gestational disease.

OBJECTIVE: To assess whether various proteolytic factors which are involved in trophoblast invasion show different concentrations in plasma and placenta of patients with HELLP syndrome, pre-/eclampsia and highly pathological Doppler flow measurements but without additional complications (hpD). DESIGN: Case control and observational study; 18 women with HELLP syndrome, 21 with pre-/eclampsia, 13 with hpD, as well as healthy pregnant women (matched pairs); statistical analysis: sign test and Wilcoxon test. RESULTS: Urokinase-type plasminogen activator (uPA), uPA receptor, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1), matrix metalloproteinases MMP-8, MMP-9 and tissue inhibitor of metalloproteinases TIMP-1 were measured by ELISA. PAI-1 plasma levels are significantly elevated in all three groups studied. In HELLP syndrome, tPA and TIMP-1 are also elevated, and in patients with hpD, MMP-8 is increased, whereas MMP-9, and TIMP-1 are lower. In placenta extract, only pre-/eclampsia shows reduced MMP-9 concentrations. CONCLUSIONS: The increased frequency of small-for-gestational-age infants observed in all three study groups is an expression of impaired placental implantation and remodelling processes. These disturbances manifest themselves in the form of changes in some of the factors in plasma and placenta extract that are involved in these processes.

Adult↗
PubMed1978

Purification and some properties of ovine placental lactogen.

A method has been described for the purification of ovine placental lactogen (oPL) involving the use of freshly obtained sheep foetal cotyledons. Tissue was extracted with 0.1 M-ammonium bicarbonate and the supernatant fraction, adjusted to pH 7, was brought to 60% saturation with ammonium sulphate. The resulting precipitate was then subjected to a sequence of chromatographic steps using columns of Sephadex G-100 and carboxymethylecellulose. During each stage of the purification, the lactogenic activity was monitored with a pregnant rabbit mammary gland radioreceptor assay. The yield of oPL corresponded to 8 mg/kg wet foetal tissue and the oPL possessed lactogenic activity equivalent to 1 mg ovine prolactin/mg protein and GH-like activity equivalent to 0.8 mg human GH/mg protein. The biological activity of oPL was confirmed using a rabbit intraductal mammary gland assay in vivo. After polyacrylamide gel electrophoresis at pH 8.9, oPL was resolved into one major band (isoelectric point 8.2--8.4) and four minor components, which were thought to be deamidation products of oPL. Microimmunoelectrophoresis and immunodiffusion studies confirmed that the preparation of oPL was free from serum protein contaminants.

Animals↗
PubMed1992

Expression of the cDNA for NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase as a catalytically active enzyme in Escherichia coli.

NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is a key enzyme involved in the catabolism of the prostaglandins. The cDNA for human placental 15-PGDH has been expressed in Escherichia coli as a catalytically active protein. The polymerase chain reaction was used to introduce restriction endonuclease sites at each end of the 15-PGDH coding sequence. The 15-PGDH DNA was then inserted into the bacterial expression plasmids pUC-18 and pUC-19 which contain the isopropyl-l-thio-beta-D-galactopyranoside (IPTG) inducible lacZ promoter. Extracts from E. coli containing these expression plasmids exhibited 15-PGDH activity which was inducible with (IPTG). Crude extracts from E. coli expressing 15-PGDH activity were found to contain proteins of the predicted sizes in stained SDS-polyacrylamide gels and in Western blots using human placental 15-PGDH antiserum. The specific activity in E. coli extracts was several hundred-fold higher than that seen in extracts from human placenta.

Amino Acid Sequence↗
PubMed1977

Human beta-glucuronidase. I. Recognition and uptake by animal fibroblasts suggests animal models for enzyme replacement studies.

As part of an effort to develop an animal model for studies of uptake of human beta-glucuronidase, fibroblasts were established from primary explants of connective tissue from nine different animal species, and examined for their ability to take up human platelet beta-glucuronidase. Endogenous fibroblast beta-glucuronidase was inactivated by heating extracts to 65 degrees for 30 min. Human beta-glucuronidase was stable to this treatment. Uptake of human beta-glucuronidase by animal fibroblasts was measured as heat-stable beta-glucuronidase present in fibroblasts after exposure to partially purified human platelet beta-glucuronidase for 48 hr. Althought all animal fibroblasts examined exhibited some uptake capacity for human beta-glucuronidase, the uptake capacity of different animal fibroblasts varied over a 10-fold range. The uptake capacity of bovine fibroblasts was at least 80% that of human fibroblasts. Rat and hamster fibroblasts showed about half the uptake capacity of human fibroblasts. The rat fibroblasts resembled the human fibroblasts in the kinetics of uptake of hihg uptake (platelet) enzyme, poor uptake of human placental enzyme, and lack of appreciable turnover of enzyme taken up over 4 days. Heating extracts of rat organs containing added human beta-glucuronidase at 65 degrees selectively inactivated rat enzyme.

Animals↗
PubMed1981

Human liver nucleolar antigens.

In an extension of previous studies on the antigens in rat liver nucleoli (R. K. Busch, R. C. Reddy, D. H. Henning, and H. Busch, Proc. Soc. Exp. Biol. Med. 160, 185 (1979); R. K. Busch and H. Busch, Tumori 63, 347 (1977); F. M. Davis, R. K. Busch, L. C. Yeoman, and H. Busch, Cancer Res. 38, 1906 (1978), rabbit antibodies were elicited to human liver nucleoli isolated by the sucrose--Mg2+ method (10). Fluorescent nucleoli were found in liver cryostat sections treated with rabbit anti-human liver nucleolar antibodies followed by fluorescein-conjugated goat anti-rabbit antibodies. In HeLa cells, fluorescence was distributed throughout the nucleus and in a nuclear network but was not localized to the nucleolus. In placental cryostat sections, an overall nuclear fluorescence was observed with some localization to nucleoli. Immunodiffusion analysis revealed two immunoprecipitin bands which appeared to be liver specific. Other immunoprecipitin bands were common to liver, placenta, and HeLa nuclear extracts. Rocket immunoelectrophoresis revealed two liver-specific antigens, one migrating to the cathode and the other to the anode Other rockets exhibited identity to antigens of other nuclear extracts. These results demonstrate the presence of human liver nucleolar-specific antigens which were not found in the HeLa and placental cells.

Antigens↗
PubMed1995

Isolation of a bovine uterotropic placental factor and development of an enzyme immunoassay in peripheral serum.

Bovine uterotropic placental factor (bUTPF) was obtained from bovine term placentae that had been homogenized and extracted in acidic medium. The extracts were chromatographed on Sephadex G-75, a fraction named native bUTPF was obtained, and an antiserum was generated. The native bUTPF was chromatographed on Sephacryl S-300 HR, and a 230-kDa fraction was obtained. A competitive enzyme immunoassay (EIA) was developed to determine bUTPF levels during gestation. This EIA was linear between 0 and 80 micrograms/ml (with a detection limit of 0.2 microgram/ml) and showed intraassay and interassay coefficients of variation of 11.2% and 15.5%, respectively. Bovine UTPF serum levels during gestation were determined by means of a cross-sectional study between the first month of gestation and delivery. Maximal serum levels of bUTPF were found during the first month of gestation: 7.1 +/- 1.9 micrograms/ml (p < 0.05). In another cross-sectional study, blood samples were collected from 105 cows between 8 and 25 days postinsemination (day of insemination = Day 0). Levels of bUTPF were found to be significantly higher (p < 0.05) by Day 17 compared to Day 0 (5.8 +/- 2.2 micrograms/ml vs. 1.2 +/- 0.7 micrograms/ml). We conclude that bUTPF is detected by EIA in maternal peripheral serum early during gestation in the bovine species.

Animals↗
PubMed1995

Fed before diethylnitrosamine, Fusarium moniliforme and F proliferatum mycotoxins alter the persistence of placental glutathione S-transferase-positive hepatocytes in rats.

Groups of 5-w-old F344/N female rats were fed a semipurified diet for 13 w with or without 20 mg fumonisin B1/kg provided from an aqueous extract of Fusarium moniliforme-corn culture. After 1 w, a single dose of 30 mg diethylnitrosamine (DEN)/kg was given orally. Twelve weeks later, the presence of placental glutathione S-transferase-positive (PGST-[+]) hepatocytes were immunohistochemically quantified. Rats given DEN and the FB1-containing diet for 1 or 13 w developed 4-fold more PGST-[+] hepatocytes than rats given DEN alone. In a second study, male and female F344/N rats were fed 20 mg purified FB1/kg diet or F proliferatum-corn culture material containing 20 mg FB1/kg diet for 1 w before DEN treatment. One week after DEN treatment, male rats fed the F proliferatum-corn culture material had significantly fewer PGST-[+] hepatocytes than those fed DEN with or without purified FB1. At 9 w after DEN treatment, PGST-[+] cells in female rats given DEN and fed F proliferatum-corn culture material were more persistent than in rats given DEN alone. Males given DEN and fed FB1 or F proliferatum culture material had significantly fewer PGST-[+] hepatocytes than males given DEN alone. These results suggest that F moniliforme and F proliferatum components are cocarcinogens in females. In males, however, FB1 and unidentified F proliferatum components reduced the persistence of DEN-initiated preneoplastic hepatocytes.

Administration, Oral↗
PubMedDate not supplied

The structure of placental glycogen.

Glycogen was purified from human term placenta and its structural features investigated. The beta-amylolysis limit and average chain lengths indicated that some degradation of the glycogen had occurred prior to its extraction. The sedimentation coefficient distribution of the purified glycogen showed that it contained a significant proportion of aggregated material. Diffusion coefficient measurements allowed calculation of the molecular weight distribution. The placental glycogen contained a significant proportion of high molecular weight material, although not as much as liver or skeletal muscle glycogens. Because the high molecular weight glycogen of liver and skeletal muscle is associated with the lysosome it is likely that this is also true of the large placental glycogen. Lysosomal glycogen is degraded hydrolytically to glucose and so placental glycogen may be involved in fetal glucose homeostasis.

Chemical Phenomena↗
PubMed1983

Characterization of polypeptides serologically and structurally related to hexosaminidase in cultured fibroblasts.

Human fibroblasts synthesize several polypeptides that assort into the various forms of hexosaminidase (hex). We report here the occurrence of three newly identified, hexosaminidase-related polypeptides resolved by sodium dodecyl sulfate-poly-acrylamide gel electrophoresis of immunoprecipitates from [35S]methionine-labeled cell extracts. These polypeptides, called band 2 (75,000), band 3 (70,000), and band 4 (63,000), were immunoprecipitated by an antiserum specific to placental hex I2. They are distinct from pre-alpha- (60,000) and pre-beta- (58,000) precursor polypeptides and the alpha- (56,000), beta a- (27,000), and beta b- (27,000) polypeptides of the mature hex A (alpha beta a beta b) and hex B (2[beta a beta b]). When fibroblast extracts were chromatographed on DEAE-Sepharose, bands 2, 3, and 4 were eluted together in fractions before hex A, in a position characteristic of serum and placental hex I2 and serum hex P. This suggests that bands 2, 3, and 4 might represent the polypeptides of a fibroblast hex I. The analysis of partial proteolytic digests of the radioactively labeled polypeptides revealed that bands 2 and 3, pre-beta, and beta a had several peptides in common, suggesting that they are structurally related to each other. However, bands 2, 3, and 4 were present in extracts of Tay-Sachs (pre-alpha and alpha deficiency) and Sandhoff cells (pre-beta, beta a, and beta b deficiency) and appeared later than pre-beta in pulse-chase experiments. These results suggest that bands 2 and 3 occur independently of pre-beta and beta a and are probably specified by different mRNA, whether from the same gene or distinct but homologous genes.

Animals↗