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Biomedical subjects

J Hau

Publications and source records attributed to J Hau.

At least 73 records · Page 4Linked to original sources
PubMed1989

Enzyme activity electrophoresis and rocket immunoelectrophoresis for the qualitative and quantitative analysis of Geotrichum candidum lipase activity.

The development and application of a rocket immunoelectrophoretic and an enzyme activity electrophoretic assay for the qualitative analysis of Geotrichum candidum lipase activity is presented. The sensitivities of the four assays were (in arbitrary units): enzyme activity electrophoresis, 1-0.5; rocket immunoelectrophoresis, 0.5-0.2; radial diffusion, 1; titrimetry, 1. The electrophoretic methods made it possible to distinguish between high and low molecular weight forms of the G. candidum lipases. The enzyme activity electrophoretic methods can be combined with other electrophoretic techniques, as demonstrated here with isoelectric focusing, and produce useful information on physico-chemical differences between different molecular forms of the lipase, e.g. forms with different pI.

Geotrichum↗
PubMed1989

Enzyme activity electrophoresis: development and applications.

The development of rocket enzyme activity electrophoresis for the detection and quantification of various proteinases, lipases and pectinases is presented. Rocket enzyme activity electrophoresis is more sensitive than the radial diffusion assay and often enables distinction between qualitatively different enzymes present in the same samples, whereas the radial diffusion assay only provides information on the overall enzyme activity. However, calibration and optimization of the enzyme activity electrophoretic assay have to be performed for each new enzyme-substrate system to be analyzed. Some of the common pitfalls in the development of new enzyme activity electrophoretic assays are presented. Enzyme activity electrophoresis can be applied in combination with other electrophoretic assays. Particularly the combination of enzyme activity electrophoresis with various immunoelectrophoretic methods can provide detailed information on the enzymes studies.

Electrochemistry↗
PubMed1989

Synovial fluid proteins in degenerative joint disease in dogs.

Concentrations of three immunoglobulins, albumin, ceruloplasmin, alpha-2 macroglobulin and pregnancy zone protein were estimated by immunoelectrophoresis in paired samples of synovial fluid and serum from 12 dogs with degenerative joint disease (DJD) and six normal dogs. The ratios of synovial fluid to serum concentrations (SF/S) of the four non-immunoglobulins showed an almost inverse linear relationship with their molecular weight in both groups. The SF/S were higher in the DJD synovial fluid than in normal synovial fluid. The difference increased with increasing molecular weight and was highly significant for the largest molecules, reflecting an increased permeability and inflammation in the synovial membrane of DJD joints. The SF/S ratios of the three immunoglobulins studied were compared to the diffusion curves of the four non-immunoglobulins. The SF/S ratios of IgM from dogs with DJD exceeded those calculated from the molecular weights. The present observations support the concept that DJD should be considered an inflammatory disease and suggest that immunologic processes may initiate and/or sustain the inflammation.

Albumins↗
PubMed1989

Localization of plasmin on the surface of the human trophoblast.

The present study demonstrates the localization of plasmin on the surface of the microvilli of the human placenta using indirect immunofluorescence. This localization might explain why serum levels of fibrin/fibrinogen degradation products are higher in the uterine vein than in the uterine artery. In view of the previous finding of pregnancy zone protein on the trophoblastic surface and the affinity between plasmin and pregnancy zone protein, it is suggested that pregnancy zone protein immobilizes plasmin on the trophoblastic surface.

Female↗
PubMed1988

Interaction between pregnancy zone protein and plasmin.

Pregnancy zone protein (PZP, alpha 2-PAG, SP3) was found to bind to plasmin in crossed affino-immunoelectrophoresis using sodium caseinate in the first dimension gel. The plasmin presence in the PZP-plasmin complex was confirmed by addition of antiserum against plasminogen to the gel. In crossed affino-immunoelectrophoresis using plasmin in the first dimension gel a non migrative PZP immunoreactive peak appeared, similar to the peak obtained with casein in the first dimension gel. Incubation of mixtures of PZP and plasmin also demonstrated complex formation between PZP and plasmin. The complex between PZP and plasmin could be precipitated not only by anti-PZP antibodies, but also by anti-plasminogen antibodies, confirming the interaction between the two molecules. The significance of the binding between plasmin and PZP remains to be elucidated, but it is tempting to speculate that PZP, present on the trophoblastic surface, immobilizes plasmin, rendering this molecule able to perform a local fibrinolytic activity.

Caseins↗
PubMed1987

Effect of homogenization and pasteurization on the allergenicity of bovine milk analysed by a murine anaphylactic shock model.

In a factorial design study a murine anaphylactic shock model was used to analyse the effect of homogenization, pasteurization, and fat content on the ability of bovine milk to induce anaphylactic reactions. Mice were sensitized by either oral or subcutaneous immunizations with various types of bovine milk. In spite of a significantly higher antibody titre in the mice sensitized subcutaneously, there was no difference in the sensitivity between orally and subcutaneously immunized mice with respect to anaphylactic reactions. Pasteurization did not seem to change the ability of milk to induce anaphylactic reactions. However, increasing fat contents in combinations with homogenization resulted in an increase of the ability of the milk to induce anaphylactic reactions.

Anaphylaxis↗
PubMed1987

Murine passive cutaneous anaphylaxis test (PCA) for the 'all or none' determination of allergenicity of bovine whey proteins and peptides.

A passive cutaneous anaphylaxis test (PCA) for determination of the allergenicity of bovine whey proteins and peptides was developed in mice. Antisera against whey proteins raised in rabbits and in mice, using a procedure for high IgE titre mixed with Freund's incomplete adjuvant, were applied intradermally, and various whey proteins and whey protein hydrolysates were tested for positive PCA reaction. Unhydrolysed whey and peptides larger than 6500 Da were found to react positively, peptides between 6500 Da and 3400 Da reacted weakly, whereas peptides smaller than 3400 Da were unable to initiate a reaction. The studies indicate that guinea-pigs, widely used by tradition, may be successfully replaced by mice in determination of the allergenicity of various compounds. The sensitivity of the two species is similar, but the husbandry and handling of mice is more convenient, and they are less expensive.

Allergens↗
PubMed1987

A murine model for the assessment of placental and fetal development in teratogenicity studies.

During normal pregnancy in the mouse, maternal serum levels of the analogues to human schwangerschaftsprotein-1 and alpha-fetoprotein correlate significantly with the growth of the placenta and fetus respectively. This relationship has been utilized in the analysis of the effect of sodium selenite on placental and fetal growth in mice. Moderate doses of sodium selenite did not affect the growth of the placenta and fetus significantly, whereas high doses of selenite resulted in a large percentage of abortions. The protein markers were found to be useful in the prediction of placental and fetal growth, and they are suggested to be of general use in the study of the impact of teratogenic substances, since they reflect the status of the fetoplacental mass during gestation.

Abnormalities, Drug-Induced↗
PubMed1987

Diagnosis and monitoring of pregnancy in mice: correlations between maternal weight, fetal and placental mass and the maternal serum levels of progesterone, pregnancy-associated murine protein-2 and alpha-fetoprotein.

Outbred Bom:NMRI mice were weighed daily for 18 days from observation of a vaginal plug. In a separate experiment, fetuses and placentae were weighed on each day of pregnancy. Pregnancy can be determined with 99% certainty on day 12 of gestation by the maternal body weight increase from day 1. The pregnancy-specific proteins alpha-fetoprotein (m-AFP) and pregnancy-associated murine protein-2 (PAMP-2), of fetal and placental origin respectively, were detectable on days 8 and 10 in the maternal circulation. Significant correlations were observed between m-AFP and fetal weight and PAMP-2 and placental weight. These markers may therefore be useful in the monitoring of fetal growth and placental growth respectively.

Animals↗
PubMed1987

Effects of growth hormone on pregnancy-associated murine protein-1.

In male mice which normally do not synthesize measurable amounts of the pregnancy-associated murine protein-1 (PAMP-1), synthesis occurred when there was continuous infusion of hGH but not by repeated subcutaneous injections. The decrease in PAMP-1 values after hypophysectomy in female mice was rapidly restored by continuous infusion of hGH, 80 micrograms daily. PAMP-1 has generally been regarded as an 'oestrogen-inducible' protein regulated by the oestrogen/androgen balance. Our results suggest that the apparent effects of sex steroids are mediated via the pituitary and possibly growth hormone secretion.

Animals↗
PubMed1986

Effect of encephalomyocarditis (EMC) virus on murine foetal and placental growth monitored by quantification of maternal plasma levels of pregnancy-associated murine protein-2 and alpha-fetoprotein.

The present study demonstrates that pregnant mice seem to be more sensitive to encephalomyocarditis (EMC) infection than non-pregnant mice, and the infection results in significantly increased maternal plasma levels of insulin and pregnancy-associated murine protein-2 (PAMP-2), of placental origin, and alpha-fetoprotein (AFP), of foetal origin. Maternal plasma levels of PAMP-2 and AFP are correlated with placental and foetal growth respectively. This indicates that the EMC infection and the increased peripheral insulin levels lead to increased growth of the foetoplacental unit.

Animals↗
PubMed1986

Initiation and control of ovulation in the mouse luteal phases. Effects of gonadotropins and gonadotropin releasing hormone.

The aim of the present study was to examine the induction of ovulation during pregnancy, pseudopregnancy, and suckling-delayed pregnancy in mice using exogenous gonadotropins. The present results demonstrate that there are mature follicles in the ovary which can be induced to ovulate with administration of either exogenous human chorionic gonadotropin (hCG) or luteinizing hormone (LH) during pregnancy (Days 1-12) and pseudopregnancy (Days 4-8) in the mouse. hCG was relatively ineffective in initiating ovulation during suckling-delayed pregnancy, and hCG could not induce ovulation on Days 3-6 in any animals, suggesting that follicular growth is not continuous during suckling-delayed pregnancy in the mouse. Ovulation occurred in pregnant and pseudopregnant mice following injection of gonadotropin releasing hormone (GnRH) in a gelatin delay vehicle. Injection of GnRH in saline did not initiate ovulation in pregnant or pseudopregnant mice. A large release of LH was shown to occur following injection of GnRH in gelatin, but no release occurred after the same dose of GnRH in saline. In conclusion, the experiments demonstrate the existence of mature follicles during murine pregnancy and pseudopregnancy, and the lack of inductable follicles during suckling-delayed pregnancy.

Animals↗
PubMed1986

Initiation and control of ovulation in the mouse luteal phases. Effects of oestrogen, progesterone and prolactin.

The aim of the present study was to examine the effect of exogenous oestrogen and progesterone on ovulation in early pregnant mice and at the end of pseudopregnancy. The results demonstrate that there are mature follicles during early pregnancy which were induced to ovulate by administration of large doses of oestrogen (greater than or equal to 10 micrograms) on day 4 of pregnancy. Ovulation was also induced by inhibition of progesterone secretion with bromocriptine. If progesterone or prolactin was given in conjunction with bromocriptine, the ovulation effect was abolished. At the end of pseudopregnancy, the spontaneous ovulation was inhibited by injections of progesterone (1.0 mg). Oestrogen given by itself at the end of pseudopregnancy caused the animals to mate earlier than the control animals. This confirms the presence of mature follicles in mice during pregnancy and suggests that the LH peak needed for ovulation can either be provoked by administration of oestrogen or by blocking of progesterone.

Animals↗
PubMed1986

Quantitative comparison of circulating immune complexes in normal pregnancy and pregnancy related hypertension.

Using two different Clq-dependent assays for quantification of circulating immune complexes (CIC), the levels were compared in sera from 32 women with pregnancy-related hypertension and in sera of 32 matched controls. No difference in the CIC levels was observed. The levels of CIC in the hypertensive patients were not correlated to placental weight, fetal weight, or diastolic blood pressure.

Antigen-Antibody Complex↗
PubMed1985

Rocket line immunoelectrophoresis: an improved assay for simultaneous quantification of a mink parvovirus (Aleutian disease virus) antigen and antibody.

A rocket line immunoelectrophoretic assay (RLIE) was developed for the simultaneous quantification of viral antigens and antiviral antibodies of the important mink parvovirus, Aleutian disease virus (ADV). The sensitivity of the RLIE assay was found to be 5 log2 higher than that of the counter current immunoelectrophoresis which is the assay routinely used for diagnostic purposes.

Aleutian Mink Disease Virus↗
PubMed1985

Placental protein and hormone measurements in twin pregnancy.

Maternal serum levels of human placental lactogen (hPL), schwangerschaftsprotein 1 (SP1), pregnancy-associated plasma protein A (PAPP-A), placental protein 5 (PP5) and total oestriol (E3) were measured serially in 35 twin pregnancies during the third trimester. Eighteen pregnancies had major complications including dysmaturity of one or both fetuses in nine, premature labour in six, and placental abruption in three. Serum levels of all five variables were higher than in singletons, this distinction being greatest for hPL and lowest for SP1 and E3. The levels of hPL, PP5 and E3 just before delivery were significantly correlated with the total birthweight, a correlation with placental weight being evident only for hPL and PP5. A significant correlation between the five biochemical variables at 33-34 weeks was only seen between hPL and PAPP-A. Protein and hormone levels in the abnormal twin pregnancies were not apparently different from those in the normal twin pregnancies. These data suggest that only hPL levels biochemically reflect this extreme of fetal and placental growth, but that neither the levels of hPL nor any of the other biochemical indices examined are altered in abnormalities in twin pregnancy.

Birth Weight↗