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PubMed1983

Plasma levels of luteinizing hormone, estradiol and androstenedione in sows with inadequate plasma progesterone.

The authors report the profiles of luteinizing hormone (LH), estradiol (E2), progesterone (P) and androstenedione (A) in some female pigs with altered plasma hormonal levels. Twenty cycles are described and 19 out of them are characterized by low plasma P in luteal phase of different etiology, at least as measured by hormone concentrations. The following disorders are observed: a) possible impairment of follicular maturation; b) impaired LH secretion in presence of too high E2; c) low LH base-line values; d) inadequate luteal phase; e) short luteal phase; f) heat disorders. An attempt is made to correlate the altered hormonal profiles with the high rate of summer conception failure in sows.

Androstenedione↗
PubMed2002

Comparative analysis of ancient ceramics by neutron activation analysis, inductively coupled plasma-optical-emission spectrometry, inductively coupled plasma-mass spectrometry, and X-ray fluorescence.

The accurate measurement of the maximum possible number of elements in ancient ceramic samples is the main requirement in provenance studies. For this reason neutron activation analysis (NAA) and X-ray fluorescence (XRF) have been successfully used for most of the studies. In this work the analytical performance of inductively coupled plasma-optical-emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS) has been compared with that of XRF and NAA for the chemical characterization of archaeological pottery. Correlation coefficients between ICP techniques and XRF or NAA data were generally better than 0.90. The reproducibility of data calculated on a sample prepared and analysed independently ten times was approximately 5% for most of the elements. Results from the ICP techniques were finally evaluated for their capacity to identify the same compositional pottery groups as results from XRF and NAA analysis, by use of multivariate statistics.

Journal Article↗
PubMed2001

Immunolocalization of plasma-membrane H+-ATPase and tonoplast-type pyrophosphatase in the plasma membrane of the sieve element-companion cell complex in the stem of Ricinus communis L.

Plasma-membrane-located primary pumps were investigated in the sieve element (SE)-companion cell complex in the transport phloem of 2-week-old stems of Ricinus communis L. and, for comparison, in stems of Cucurbita pepo L. and in the secondary phloem of Agrobacterium tumefaciens-induced crown galls as a typical sink tissue. The plasma-membrane (PM) H+-ATPase and the tonoplast-type pyrophosphatase (PPase) were immunolocalized by epifluorescence and confocal laser scanning microscopy (CLSM) upon single or double labeling with specific monoclonal and polyclonal antibodies. Quantitative fluorescence evaluation by CLSM revealed both pumps in one membrane, the sieve-element PM. Different PM H+-ATPase antibody clones, raised against the PM H+-ATPase of Zea mays coleoptiles, induced in mouse and produced in mouse hybridoma cells, discriminated between different phloem cell types. Clones 30D5C4 and 44B8A1 labeled sieve elements and clone 46E5B11D5 labeled companion cells, indicating the existence of different phloem PM H+-ATPase isoforms. The results are discussed in terms of energization of SE transporters for retrieval of leaking sucrose, K+ and amino acids, as one of the unknown roles of ATP found in SEs. The function of the PPase could be related to phloem sucrose metabolism in support of ATP-requiring processes.

Antibodies, Monoclonal↗
PubMed2000

Salivary, total plasma and plasma free cortisol in panic disorder.

BACKGROUND: Research on basal HPA axis activity in patients with panic disorder showed inconsistent results. METHODS: Basal total plasma, plasma free and salivary cortisol levels were compared in patients with panic disorder (n = 47) and in healthy individuals (n = 23). Correlations between these fractions were calculated. RESULTS: All three basal cortisol fractions were significantly elevated in patients compared to controls. There were significant correlations between all three cortisol fractions. CONCLUSIONS: Nonsignificant differences between cortisol levels of patients and healthy controls in previous studies may have been due to inclusion of less severely ill patients or to small sample sizes (96 words).

Adult↗
PubMed1978

The relationship of maternal anxiety, plasma catecholamines, and plasma cortisol to progress in labor.

The relationships among maternal anxiety, selected stress-related biochemical factors, and progress in three defined phases of labor were determined for 32 married, normal, primigravid women, 20 to 32 years of age. Comparisons of plasma epinephrine, norepinephrine, and cortisol in third-trimester pregnancy, during labor, and after delivery are provided. At the onset of Phase 2 of labor (3 cm. of cervical dilatation), self-reported anxiety and endogenous plasma epinephrine are significantly correlated. With the deletion of subjects to control for the effect of medications, higher epinephrine levels are significantly associated with lower uterine contractile activity at the onset of Phase 2 and with longer labor in Phase 2 (3 to 10 cm. of cervical dilatation). The relationship between epinephrine and progress in labor is explained by an adrenoreceptor theory.

Adult↗
PubMed1975

Lymphocyte plasma membranes. III. Composition of lymphocyte plasma membranes from normal and immunized rats.

Isolated plasma membranes of thymic and splenic lymphocytes from unimmunized and immunized rats of the inbred ACI and F344 strains were analyzed for chemical and enzymatic composition, for membrane protein patterns by polyacrylamide gel electrophoresis and for membrane-associated immunoglobulins. After immunization, the thymic and splenic lymphocyte membranes from F344 rat contained less carbohydrate and higher phospholipid contents than control animals. In both ACI and F344 inbred rat strains the membrane phospholipid to cholesterol weight ratio increased significantly after immunization. The electrophoretic patterns of solubilized membrane proteins and of iodinated external membrane proteins were similar in unimmunized and immunized animals. When thymic and splenic lymphocytes of normal or immunized animals were surface radioidinated, solubilized in Triton X-100, NP-40 or 10 M urea in 1.5 M acetic acid and analyzed by immunoprecipitation, labeled IgM immunoglobulin was recovered from thymic lymphocytes but both labeled IgG and IgM were recovered from splenic lymphocytes. However, when unlabeled isolated plasma membranes were solubilized in 1 percent Triton X-100 and analyzed by immunodiffusion in agarose gels both IgG and IgM were identified in thymic and splenic cells.

Animals↗
PubMed1975

Isolation and characterization of the plasma membrane of L-1210 cells. Iodination as a marker for the plasma membrane.

Mouse leukemia L-1210 cells were iodinated with 125I; this permitted the development of a method for the isolation of the plasma membranes. These show a 10- to 16-fold increase in the specific activity of 125I over that of the cell homogenate and a 20-fold increase in the specific activities of 5'-nucleotidase and alkaline phosphatase; 20-fold increase in the specific activities of 5'-nucleotidase and alkaline phosphatase; no mitochondrial or microsomal marker enzyme activities were detected. Sodium dodecyl sulfate gel electrophoresis of the plasma membranes shows approx. 40 peptides with molecular weights ranging from 10 000 to over 200 000; a polypeptide (Mr 50 000) predominates. Of 13 iodinated surface membrane proteins, the major radioactive peptide has a molecular weight of 85 000. The importance of the selection of the appropriate gel system for the analysis of membrane proteins is emphasized.

Alkaline Phosphatase↗
PubMed1994

A plasma membrane NADH oxidase is involved in copper uptake by plasma membrane vesicles isolated from rat liver.

The accumulation of copper (Cu) by hepatocytes is initiated by the binding of Cu in either a CuHis2 complex or as a CuHisAlb ternary complex, followed by transfer of the metal alone across the cell membrane. In this paper, we provide evidence that the transfer involves reduction of cupric (Cu(II)) copper to cuprous (Cu(I)) copper and further we show that membrane-bound NADH oxidase can provide the electron required for the reduction. 64Cu uptake by rat liver plasma membrane vesicles is stimulated by the addition of NADH, but not NAD+. The stimulation increases the Vmax from 4.75 +/- 0.02 to 8.38 +/- 0.40 nmol Cu/mg protein per min (P < 0.05, mean +/- S.E., n = 3) without significantly altering the K0.5 (1.52 +/- 0.17 and 2.10 +/- 0.22 mumol/l; with n values of 1.30 +/- 0.01 and 1.43 +/- 0.10, respectively; analysing by the Hill equation). Correspondingly, addition of CuHis2 stimulated NADH-oxidase activity by a maximum of 7.4 +/- 2.1 nmol/mg protein per min (P < 0.01, mean +/- S.E., n = 5) at 5 mumol/l and a NADH concentration of 150 mumol/l. Ascorbic acid also stimulated copper uptake, and points to a reductive dissociation of copper prior to its movement into the cell. Our data indicate that membrane bound enzymes can provide an electron for the reduction of copper prior to uptake and suggest a physiological role for the plasma membrane NADH oxidase.

Animals↗
PubMed1982

Transfer of [14C]phosphatidylcholine between liposomes and human plasma high density lipoprotein. Partial purification of a transfer-stimulating plasma factor using a rapid transfer assay.

A simple method was developed for the rapid determination of [14C]phosphatidylcholine transfer from small unilamellar liposomes to human plasma HDL, based on the selective precipitation of liposomes by heparin and MnCl2. The assay was utilized to monitor the progress in the partial purification of a phospholipid transfer factor from human plasma. The purification procedure included ultracentrifugation at d = 1.25 g/ml, hydrophobic chromatography on phenyl-Sepharose, affinity chromatography on heparin-Sepharose and gel filtration. The partially purified protein(s) catalyzed the net transfer of phospholipid from small unilamellar phosphatidylcholine liposomes to isolated HDL. The transfer of [14C]phosphatidylcholine from liposomes consisting of phosphatidylcholine/phosphatidylserine/cholesterol (molar ratio, 4:1:5) to HDL was stimulated without affecting the permeability barrier of the liposomal membranes and is, therefore, taken to represent exchange with HDL phospholipid rather than net transfer.

Carrier Proteins↗
PubMed1993

Hydrolysis and binding of a toxic stereoisomer of soman in plasma and tissue homogenates from rat, guinea pig and marmoset, and in human plasma.

The fallen concentration of one of the two isomers of soman (1,2,2-trimethylpropyl methylphosphonofluoridate), i.e., C(+)P(-)-soman, was investigated in plasma and in homogenates of brain, lung, liver, kidney, diaphragm, skeletal muscle and mucosa of small intestines from rat, guinea pig and marmoset, and in human plasma (pH 7.5, 37 degrees). The decrease of the isomer concentration was followed by gas chromatographic determination of the residual concentration and proceeded in two phases due to a very rapid saturation of covalent binding sites for the isomer followed by catalysed hydrolysis. Estimates for the concentrations of covalent binding sites were obtained, which were relatively high in liver and kidney. Time periods for the hydrolysis of the isomer from a concentration of 40 ng/mL to 20 ng/mL were evaluated from the second reaction phase. It is concluded that the spontaneous and enzyme-catalyzed hydrolytic activities found for degradation of C(+)P(-)-soman in organs participating in central elimination are sufficiently high to account for the terminal half-life times of the isomer found in our toxicokinetic studies for the blood concentration after intoxication with 2-6 LD50 C(+/-)P(+/-)-soman. The hydrolytic activities are lower in the target organs for toxic action of soman, e.g., diaphragm and brain, especially for guinea pigs and marmosets.

Animals↗
PubMed1992

Plasma homovanillic acid, plasma anti-D1 and -D2 dopamine-receptor activity, and negative symptoms in chronically mediated schizophrenia.

We have investigated the relationship between the concentration of homovanillic acid in human plasma (pHVA) and plasma anti-D1 and anti-D2 dopamine receptor activity in chronic schizophrenic patients whose neuroleptic dosage was changed. The change in pHVA level correlated with that in anti-D1, not anti-D2 activity, thus suggesting that the neuroleptic-induced changes in pHVA concentration may be associated with the blocking of D1- as well as D2- receptors. The change of scores on the Scale for the Assessment of Negative Symptoms did not significantly correlate with changes in anti-D1 or anti-D2 activity, but did so correlated with the change in pHVA level.

Antipsychotic Agents↗
PubMed1988

Acute ethanol treatment lowers hypophyseal portal plasma luteinizing hormone-releasing hormone (LH-RH) and systemic plasma LH levels in orchidectomized rats.

Acute ethanol (EtOH) treatment resulted in a significant decline in hypophyseal portal plasma levels of luteinizing hormone-releasing hormone (LH-RH) in orchidectomized rats. This was accompanied by a similar decrement in circulating luteinizing hormone (LH) without, however, modifying plasma follicle-stimulating hormone (FSH) levels at time when peak blood alcohol concentrations occurred. Thus, acute alcohol intoxication lowers circulating LH levels primarily by impairing hypothalamic neuronal secretion of LH-RH into the portal blood.

Animals↗
PubMed1975

Studies on plasma membranes. XXIII. Hormone-like action of concanavalin A on liver plasma membranes: inhibition of (Na+-K+)ATPase.

Concanavalin A inhibits the (Na+-K+)-ATPase activity of isolated rat-liver plasma membranes, while leaving the Mg2+-ATPase unaffected. Glucagon and cyclic AMP act supplementary to the lectin in the inhibition. The lectin effect is counteracted by insulin and L-epinephrine, and is completely abolished by the beta-adrenergic blocking agent propranolol. Results are discussed on the basis of the known interactions of concanavalin A with plasma membrane components, including its hormone-like action.

Adenosine Triphosphatases↗
PubMed1991

Interaction of seminal plasma proteins with cell surface antigens: presence of a CD4-binding glycoprotein in human seminal plasma.

We report in this paper the presence in the human seminal plasma of a glycoprotein capable of binding to CD4, a surface antigen expressed on the surface of T-cells, macrophages, and sperm cells, which acts as a coreceptor in antigen-mediated T-cell activation and as a receptor for the AIDS virus, HIV-1. This protein, namely gp17 (apparent MW = 17,500 Da), was purified by affinity chromatography and characterized by SDS/PAGE analysis. Its binding to CD4 was inhibited by anti-CD4 mAbs directed against V1, a region of CD4 implicated in the binding to MHC class II antigens and to the HIV-1 envelope protein gp120, but not by mAbs directed against other CD4 determinants. The presence of a CD4-masking factor in human seminal plasma may be relevant to the modulation of maternal immunity at insemination and to the control of sexual transmission of HIV-1.

Antibodies, Monoclonal↗
PubMed1985

Quantitative measurement of the total, peroxyl radical-trapping antioxidant capability of human blood plasma by controlled peroxidation. The important contribution made by plasma proteins.

Plasma obtained from fasted humans has been analysed for total radical-trapping antioxidant content by subjecting it to controlled peroxidation using the thermal decomposition of water-soluble azobis (2-amidinopropane hydrochloride) at 37 degrees C to produce peroxyl radicals at a known, steady rate. It is found that the total radical-trapping antioxidant content is rather similar for the 7 subjects that have been tested and, furthermore, it is 10-20-times larger than the effect attributable to vitamin E alone. Although it is shown that urate and ascorbate augment the contribution from vitamin E, their contributions (21-34 and 0-2%, respectively) still leave 57-73% of the total antioxidant content unaccounted for. Evidence is presented to show that this previously unrecognized large reserve of antioxidant capacity is attributable to the plasma proteins.

Antioxidants↗
PubMed1986

Cortisol secretion in vitro by the interrenal of coho salmon (Oncorhynchus kisutch) during smoltification: relationship with plasma thyroxine and plasma cortisol.

An in vitro system for the incubation of interrenal tissue (head kidney fragments) from coho salmon, Oncorhynchus kisutch, was developed in order to examine changes in interrenal sensitivity to ACTH1-24 during smoltification, using cortisol secretion as the endpoint. Time-course studies indicated that maximal cortisol accumulation in incubation media was achieved after 3 hr exposure to ACTH. There was no correlation between head kidney weight, body weight, or sex and the response of the interrenal to ACTH1-24 in vitro. Approximately monthly or bi-weekly experiments were performed during the smoltification period (February-July): tissue was preincubated in hormone-free media for 3 hr, washed twice, and then challenged with 5 X 10(-10)-5 X 10(-7) M (1.5-1500 ng/ml) ACTH1-24 for 3 hr. The pattern of cortisol secretion was similar in February, early March, and late March in the dose range of 5 X 10(-10)-5 X 10(-8) M ACTH1-24. A marked, significant increase in sensitivity to ACTH and in the steroidogenic capacity of the tissue occurred in April, but by May the response was similar to that in the pre-April period. Enhanced sensitivity and steroidogenic capacity were found in interrenal tissue taken from coho salmon in June and July. Maximal in vitro responsiveness of interrenal tissue to ACTH in April was correlated with peak plasma thyroxine titers and enhanced hypoosmoregulatory ability, but not with peak plasma cortisol titers, which occurred in May.

Adrenal Glands↗
PubMed1984

Increase of electrophoretic mobility and of content of soluble proteins of human plasma beta-lipoproteins by incubation of plasma in vitro.

Incubation of human plasma at 37 degrees C was shown to induce an increase in the electrophoretic mobility of beta-lipoproteins. beta-Lipoproteins were isolated by density gradient ultracentrifugation after such incubation and their composition was analysed. Incubation decreased the content of free cholesterol and increased that of soluble apolipoproteins. The soluble peptides appearing in LDL upon incubation showed 3 major and 2 minor bands upon polyacrylamide disc gel electrophoresis. Two of the major bands corresponded to apolipoprotein C-III-1 and C-III-2 and one of the minor to apolipoprotein C-II. The addition of an inhibitor to lecithin:cholesterol acyltransferase (LCAT) abolished the increase in electrophoretic mobility and to a large extent diminished the other reported effects of incubation. The hypothesis is put forward that during incubation of plasma at 37 degrees C the free cholesterol in the surface of LDL is removed through the action of LCAT, lipid transferases and exchange processes and is replaced in the surface shell by peptides which cause the change in electrophoretic mobility.

Apolipoprotein C-III↗
PubMed1993

Levels of plasma factor VII and factor VII activated forms as a function of plasma triglyceride levels.

It has been shown that triglyceride levels are one of the determinants of factor VII levels. In this study we have simultaneously evaluated, in a group of 102 healthy individuals, the different forms of factor VII, namely factor VII mass, factor VII coagulant activity, activated factor VII double-chain form and factor VII-phospholipid complex, in relation to triglyceridaemia. The data showed a highly significant correlation of factor VII mass, factor VII coagulant activity and factor VII-phospholipid complex with triglycerides. No correlation was observed between the activated factor VII double-chain form and triglycerides. These data, together with analysis of the linear and orthogonal regression slopes, suggest that increase of plasma factor VII coagulant activity as a function of plasma triglyceride levels is attributable to an increase in both mass and activity of factor VII and that the increase in activity is dependent on an increase of factor VII-phospholipid complex rather than activated factor VII double-chain form. The ratio between the slopes of the regression straight line of factor VII mass and factor VII-phospholipid complex in relation to triglycerides was 2.23 (95% confidence limits 1.74-2.50), thus indicating that the contribution of factor VII mass is prevalent over that of the factor VII-phospholipid complex.

Adult↗