Osmoregulation in juvenile and adult white sturgeon,Acipenser transmontanus

Synopsis Blood samples from cannulated young adult (2.5–15 kg) white sturgeon, acclimated to San Francisco Bay water (24 ppt) had plasma values of 248.8 ± 13.5 mOsm kg⁻¹ H₂O, [Na⁺] = 125 ± 8.0 mEq 1⁻¹, [K⁺] = 2.6 ± 0.8 mEq 1⁻¹ and [CL⁻] = 122 ± 3.0 mEq 1⁻¹. Freshwater acclimated sturgeon had an osmolality of 236 ± 7, [Na⁺] = 131.6 + 4.4, [K⁺] = 2.5 ± 0.7 and [CL⁻] = 110.6 ± 3.6. Freshwater acclimated fish gradually exposed to sea water (increase of 5 ppt h⁻¹) had higher plasma osmolalities than did the bay water acclimated fish. These young adult sturgeon are able to tolerate transfer from fresh water to sea water as well as gradual transfer from sea water to fresh water. Plasma electrolytes in transferred fish are regulated, but tend to differ from long term acclimated fish at the same salinities. There is a gradual increase in the upper salinity tolerance (abrupt transfer) of juvenile white sturgeon with weight: 5–10 ppt for 0.4–0.9 g fish, 10–15 ppt for 0.7–1.8 g fish, and 15 ppt for 4.9–50.0 g fish. The ability of juveniles to regulate plasma osmolality is limited. The young adult fish are able to tolerate higher salinities (35 ppt) than juvenile sturgeon but probably are also characterized by low activity of the necessary ion exchange mechanisms in the gills which permit rapid adjustment of blood electrolytes with graduate change in external salinity.     

Amino Acids in Plasma and CSF and Monoamine Metabolites in CSF: Interrelationship in Healthy Subjects

Plasma and cerebrospinal fluid (CSF) concentrations of amino acids were measured in 65 healthy volunteers (50 men and 15 women). The CSF levels of the monoamine metabolites homovanillic acid (HVA), 3-methoxy-4-hydroxyphenylethylene glycol (MOPEG), and 5-hydroxyindoleacetic acid (5-HIAA) were also determined. Sex differences were observed in both plasma and CSF amino acid levels as well as in the relationship between these concentrations. No significant correlations were observed between the CSF levels of HVA and 5-HIAA, and the concentrations of their precursor amino acids in either plasma or CSF. The MOPEG level in CSF correlated positively with the plasma concentrations of several amino acids.     

应用乙型肝炎疫苗阻断围产期乙型肝炎病毒的母婴传播

993名HBsAg携带者母亲所生新生儿,以768名新生儿为试验组,226名新生儿为对照组,试验组分别注射HBsAg血源性氢氧化铝佐剂疫苗,乙型肝炎高价免疫球蛋白(HBlg)或疫苗加HBIg,对照组注射安慰剂,所用疫苗为国产81-2、82-1-2、83-1和美国NIHA9,观察表明,出生后六个月,试验组各批疫苗的保护率为60～93％,以83-1批为最高;疫苗加HBIg的保护效果与疫苗相似,HBIg组亦有70％的保护效果,以上结果证明单独应用HBsAg疫苗阻断母婴传播的效果是理想的。     

Different hormonal requirements for androgen-independent growth of normal and tumor epithelial cells from rat prostate

Summary The proliferation of isolated normal prostate epithelial cells from rat and man is androgen-independent and requires cholera toxin, insulin, dexamethasone, epidermal growth factor (EGF) and one or more polypeptide factors that are concentrated in bovine neural tissue. The active agents in the neural tissue extract are heparin-binding polypeptides (prostatropins), the predominant form of which has a molecular weight of 17400 and an acetylalanine at the aminoterminus. Prostatropins supported a half-maximal increase in normal prostate epithelial cell number at 50 picomolar. The proliferation of primary and serially-cultured epithelial cells from androgen-responsive Dunning R3327 rat prostate tumors was also androgen-independent, but exhibited dramatic alterations in response to hormones that stimulated normal cell proliferation. At low cell density, androgen-independent growth of isolated tumor-derived epithelial cells was independent on cholera toxin, was stimulated by dexamethasone, required insulin andeither EGFor prostatropin. The presence of either EGF or prostatropin masked the response to the other factor. In the absence of EGF, purified prostatropins supported a half-maximal increase in tumor cell number at 7 picomolar. Endogenous production of EGF-like and prostatropin-like factors or both was suggested by the reduced requirement for EGF and prostatropin at high prostate tumor cell density. These results suggest that anti-hormonal therapies against prostate tumor growth should be based on intervention with the activity of insulin (or insulin-like factors) or simultaneous intervention with both EGF and prostatropin (or their homologues). This work was supported by NIH grants CA 37589 and HL 33847, and grant 1718 from the Council for Tobacco Research. Editor’s Statement This paper is the first report of the comparison of the hormone requirements of primary cultures of normal and tumor prostate epithelial cells from the same system.     

Effects of superovulatory doses of pregnant mare serum gonadotropin on oocyte quality and ovulatory and steroid hormone responses in rats

Immature rats (aged 28 days) were injected with 4, 20, or 40 IU pregnant mare serum gonadotropin (PMSG) and sacrificed every 6 or 12 hr. Control rats (4 IU) ovulated between 60 and 72 hr, whereas rats given superovulatory doses of PMSG (20 and 40 IU) ovulated between 24 and 72 hr. The oocyte count from the superovulated rats increased slightly between 24 and 36 hr and markedly between 48 and 72 hr. Degenerated oocytes were recovered 48 and 36 hr after administration of 20 and 40 IU PMSG, respectively. Thereafter, the proportion of degenerated oocytes was dose dependent and reached a maximum at 72 (30.9%, 20 IU) and 60 hr (61.0%, 40 IU). 17β-estradiol content of the superovulated ovaries increased significantly (P < 0.01) from 36 hr and was maximal at 60 (20 IU) or 54 hr (40 IU), when compared to the control regimen. Administration of 40 IU PMSG resulted in a biphasic increase of progesterone content with the peaks at 36 and 60 hr. Androgen content of the superovulated ovaries was lower than control levels during the first 36 hr but was significantly (P < 0.01) higher thereafter. The results suggest that these alterations in the steroid response (particularly androgens) from 36 hr onward following superovulation may be responsible for the coincidental occurrence of abnormal oocytes, possibly by disturbing the specific intrafollicular steroid environment essential for complete maturation. In addition, oocyte aging that is due to earlier activation by the exogenous luteinizing hormone activity may be a contributing factor.     

Monitoring ovulation and implantation in the cynomolgus macaque (Macaca fascicularis) through evaluations of urinary estrone conjugates and progesterone metabolites: a technique for the routine evaluation of reproductive parameters

Investigations were undertaken to determine the applicability of recently reported specific radioimmunoassays for urinary estrone conjugates and progesterone metabolites for monitoring ovarian function in the cynomolgus macaque (Macaca fasciularis) and other macaque species. Mean estrone conjugate measurements appear to accurately reflect the preovulatory estrogen peak in both conceptive (n = 5) and nonconceptive (n = 6) cycles, as well as to indicate early pregnancy through increases which are significantly elevated by Day + 15 (p less than 0.049) post estrone conjugates peak. The mean luteal phase levels of these progesterone metabolites are significantly elevated by Day + 14 (p less than 0.012) in conceptive cycles when compared to the mean values for nonconceptive cycles.     

Factor XIII-mediated cross-linking of NH2-terminal peptide of alpha 2-plasmin inhibitor to fibrin

The NH2-terminal 12-residue peptide of alpha 2-plasmin inhibitor, Asn-Gln-Glu-Gln-Val-Ser-Pro-Leu-Thr-Gly-Leu-Lys-NH2 . AcOH, was found to be a good substrate for plasma transglutaminase (activated blood coagulation factor XIII) and rapidly incorporated into fibrin by the enzyme. A high concentration of the peptide inhibited the enzyme-mediated cross-linking of alpha 2-plasmin inhibitor to fibrin probably by competing with the inhibitor for the same site of fibrin alpha-chain.     

Comparison of the properties of active Ca2+ transport by the islet-cell endoplasmic reticulum and plasma membrane

The properties of active or ATP-dependent calcium transport by islet-cell endoplasmic reticulum and plasma membrane-enriched subcellular fractions were directly compared. These studies indicate that the active calcium transport systems of the two membranes are fundamentally distinct. In contrast to calcium uptake by the endoplasmic reticulum-enriched fraction, calcium uptake by islet-cell plasma membrane-enriched vesicles exhibited a different pH optimum, was not sustained by oxalate, and showed an approximate 30-fold greater affinity for ionized calcium. A similar difference in affinity for calcium was exhibited by the Ca²⁺-stimulated ATPase activities which are associated with these islet-cell subcellular fractions. Consistent with the effects of calmodulin on calcium transport, calmodulin stimulated Ca²⁺-ATPase in the plasma membranes, but did not increase calcium-stimulated ATPase activity in the endoplasmic reticulum membranes. The physiological significance of the differences observed in calcium transport by the endoplasmic reticulum and plasma membrane fractions relative to the regulation of insulin secretion by the islets of Langerhans is discussed.     

Isolation and partial characterization of the basal cell membrane of human placental trophoblast

The function of the syncytiotrophoblast in maternal-fetal exchange is related to the properties of its microvillous (maternal-facing) and basal (fetal-facing) plasma membranes. We have previously reported the properties of the microvillous membrane (Smith, C.H., Nelson, D.M., King, B.F., Donohue, T.M., Ruzycki, S.M. and Kelley, L.K. (1977) Am. J. Obstet. Gynecol. 128, 190–196), and now describe the purification and partial characterization of the basal plasma membrane. Sonication and incubation with EDTA were used to isolate selectively the basal cell membrane. These steps were followed by a more conventional purification by centrifugation. The trophoblast was disrupted and its microvillous membrane and cytoplasmic contents were removed by sonication. The exposed basal cell membrane was selectively released from the underlying basal lamina by sonication in the presence of EDTA and further purified by discontinuous Ficoll gradient centrifugation. The material at the 4–10% Ficoll interface consisted of smooth membrane vesicles with internal microfilaments. It was 45-fold enriched in dihydroalprenolol binding activity and 11-fold enriched in ouabain binding activity. Other enzymatic analyses, including alkaline phosphatase, cytochrome-c oxidase, cytochrome-c reductase and galactosyl transferase indicated low contamination by other organelles. This procedure yields a preparation of relatively high purity which should be suitable for investigation of transport and other functions of the basal surface membrane of trophoblast. In principle, the purification procedures used may be applicable to other transporting epithelia.     

Adaptive changes in lipid composition of rat liver plasma membrane during postnatal development following maternal ethanol ingestion

The fatty acid composition of constituent phospholipids and the cholesterol content of rat liver plasma membranes were determined subsequent to maternal alcohol ingestion during pregnancy and lactation. The alcoholic group was given a liquid Metrecal diet containing 37% ethanol-derived calories. The control group was pair-fed an isocaloric sucrose/Metrecal diet. Litters were killed for lipid analyses at days 5, 15 and 25 after birth. These studies revealed that the total phospholipid phosphorus was similar and increased significantly with age in both groups. Cholesterol also increased significantly with age in both groups but was greater in the alcoholic pups, resulting in a higher cholesterol/phospholipid molar ratio. While the phosphatidylethanolamine (PE) content increased with age in both groups, that of sphingomyelin decreased. Phosphatidylserine + phosphatidylinositol (PS + PI) was significantly higher in the control group at all ages studied. A consistent increase of C22:6 in phosphatidylcholine (PC), sphingomyelin, PS + PI and in the total phospholipid fraction from alcoholic pups was observed. Although other fatty acid changes were found in PC, PS + PI and sphingomyelin, PE was not affected. These results suggest that specific adaptive changes were induced in the liver plasma membrane lipids of the progeny from alcoholic rats.