Biomedical subjects

J Hau

Publications and source records attributed to J Hau.

At least 55 records · Page 3Linked to original sources

PubMed1995

A murine model for the study of mycotic mastitis.

This study established a murine model for the study of mycotic mastitis. The mammary glands of BALB/c mice were inoculated on the fifth day of lactation with graded doses (10(4), 10(5) and 10(6) cells) of a pathogenic strain of Candida krusei isolated from bovine mastitis. The animals were killed 1, 2, 3, 4 or 5 days after inoculation. In the infected mammary glands, the pathological reaction consisted of primary infiltration with heterophils and mononuclear cells, focal necrosis, formation of microabscesses, epithelial hyperplasia and some fibrosis. The severity of the changes was dose-dependent and increased with time after infection. An increase in the plasma concentrations of complement factors C1, C3c, C4 and C5, factor B and alpha-2-macroglobulin suggested that an acute phase response and activation of the complement system had occurred as a result of the infection.

Acute-Phase Reaction↗

PubMed1995

Effect of oral corticosterone administration on locomotor development of neonatal and juvenile rats.

In order to simulate the elevated corticosteroid levels to which offspring of stressed women may be subjected, rat pups were treated daily with two levels of oral corticosterone from the 2nd to the 15th postnatal day. The rat pups were subjected to swimming tests from their 8th postnatal day to examine their neuromuscular development and learning abilities. The locomotor performance of corticosterone-treated groups was similar to that of controls but its development was delayed, which demonstrates that even relatively low levels of corticosterone have a significant negative influence on the maturation and learning ability of neonatal rat pups. This indicates that the glucocorticoid levels to which suckling neonates (for example, children of women suffering from stress) might be exposed could modify the complex integrated neuromuscular adaptive mechanisms involved in normal locomotor development.

Animals↗

PubMed1995

Serum levels of selected liver proteins following partial hepatectomy in the female rat.

Liver regeneration in the rat following partial hepatectomy (PH) is a frequently used model to study regulatory mechanisms in relation to cell growth and differentiation. In the present study, we analysed quantitative changes in the peripheral circulation of a number of important serum proteins following PH and laparotomy. Alpha-fetoprotein synthesis was induced in the PH rats and remained at very low levels in non-operated controls. Pregnancy-associated murine protein-1 levels and fibronectin levels were lower in the circulation of all operated animals compared with the intact controls. The serum levels of alpha-2 macroglobulin were elevated in all operated animals compared with the non-operated controls. Circulating complement factors C3c and C4 were present at significantly lower levels in PH animals than in rats following laparotomy. Small growth stimulating molecules (< 10 kDa) synthesized by different organs during the regenerative process have been described in the literature, but dialysates of the spleen and liver from non-operated rats and PH rats showed no significant impact on serum levels of the proteins in the present study.

Animals↗

PubMed1995

Induction of systemic zygomycosis in pregnant mice by Absidia corymbifera.

Intravenous inoculation of pregnant BALB/c mice with 10(3) to 10(5) Absidia corymbifera spores resulted in mycotic placentitis when 10(4) or more spores were given. Compared with challenge on day 10, challenge on days 12 and 14 of pregnancy resulted in significantly more placentas being infected. Placentitis was seen in 2.4 to 6.7% of the placentas from animals given 10(4) spores on days 12 and 14 respectively, compared with 14.0 and 15.2% of the placentas in animals challenged on the same days with 10(5) spores. Absidia corymbifera did not have particular affinity for placental localization because extrauterine organs were also frequently [abstract incompletely published]

Animals↗

PubMed1995

Development and comparison of purification strategies for chicken antibodies from egg yolk.

With regard for animal welfare as well as cost, antibodies purified from the egg yolk of immunized chickens are an attractive alternative to antibodies raised in serum of mammals. Various purification strategies based on initial purification by a freeze-and-thaw method followed by one of three precipitation methods--ammonium sulfate, polyethylene glycol 6000, or caprylic acid--were compared. Ammonium sulfate precipitation (25 to 40%) was found to give the best combination of high purity and yield (58%). Moreover, this method is inexpensive and well suited for standard purification of egg yolk antibodies in large scale production facilities.

Ammonium Sulfate↗

PubMed1993

Changes in blood levels of proteinase inhibitors, pregnancy zone protein, steroid carriers and complement factors induced by oral contraceptives.

Three low-dose oral contraceptives Trinordiol, Gynatrol, and Marvelon, containing ethinylestradiol (EE) in combination with triphasic levonorgestrel (LNg), monophasic levonorgestrel, and monophasic desogestrel (DGS), respectively, were given to 65 healthy women, n = 21-22 in each group. Blood levels of antithrombin III (AT III), alpha 2-macroglobulin (alpha 2M) alpha 1-antitrypsin (alpha 1at), complement factors (factor B, C3, C4), pregnancy zone protein (PZP), corticosteroid binding globulin (CBG), sex hormone binding globulin (SHBG) and albumin were measured before treatment and during the first and third treatment cycles. AT III levels decreased and alpha 1at levels increased in all three groups during treatment. alpha 2M increased during cycle 3 in the Trinordiol and Gynatrol groups. CBG, PZP and SHBG levels increased in all 3 groups, the CBG and PZP increase being higher in the Marvelon group than in the Gynatrol group. Increases in SHBG levels were found in the order Marvelon > Trinordiol > Gynatrol. Plasma levels of complement factors B, C3 and C4 remained unchanged. It is concluded that the increase in alpha 1at partly compensates for the fall in AT III, that the rise in PZP presumably enhances fibrinolysis, and that LNg has higher anti-estrogenicity and androgenicity than DSG.

Adolescent↗

PubMed1993

Development of the KVL segregating inbred strain of the Syrian hamster (Mesocricetus auratus).

A new colony of a single segregating inbred strain of the Syrian hamster (Mesocricetus auratus), designated KVL, has recently been developed at the Royal Veterinary and Agricultural University, Copenhagen, Denmark. The segregation occurs with respect to coat colour (pied gray/pied brown) as a result of inbreeding with forced heterozygosity. After 20 generations average litter size was 6.7 at birth and 5.57 at weaning. Mean generation interval was 89.4 days. An initially significant decrease in productivity (inbreeding depression) levelled out with further generations and has now stabilized. The colony is being maintained.

Animals↗

PubMed1993

Levels of alpha2 pregnancy-associated glycoprotein in maternal circulation during pregnancy in the mink.

This is the first demonstration of alpha 2-pregnancy-associated glycoprotein (alpha 2-PAG) in the mink. Mink alpha 2-PAG exhibits complete immunological cross reaction with dog alpha 2-PAG when analysed in assays employing antisera against canine alpha 2-PAG raised in rabbits. Alpha 2-PAG was quantitated by rocket immunoelectrophoresis in heparin plasma samples obtained from the peripheral circulation of mink during the breeding season. The plasma levels recorded in male mink were significantly lower (23 AU/ml) than the levels recorded in females at any stage of the breeding period. Very early in the breeding season and 2 weeks after delivery the alpha 2-PAG levels were high (> 200 AU/ml) in the circulation of the female mink. Like alpha 2-PAG in the pregnant bitch, mink alpha 2-PAG concentrations reach a local maximum in mid-pregnancy, and a local minimum at term.

Animals↗

PubMed1993

[Studies on the low skin impedance points and the feature of its distribution along the channels by microcomputer. II. Distribution of LSIPS along the channels].

The distribution of low skin impedance poionts (LSIPS) was observed on 60 healthy volunteers with a computer system designed to measure the skin impedance. The results demonstrated that LSIPs basically distributed along the channels. The method used was reliable and results obtained was repeatable. Some problems, which puzzled the researchers for so many years, now have been clarified and the method for measuring the skin impedance has been developed to a new level. Under the specified condition, the skin impedance can be used as an indicator to plot out the courses of channels in the research.

Adult↗

PubMed1992

Pregnancy-associated murine protein-1 (PAMP-1) in wild rodents.

The presence of pregnancy-associated murine protein-1 (PAMP-1) in a number of wild rodent species was examined using tandem crossed immunoelectrophoresis and anti PAMP-1 antisera raised in rabbits. PAMP-1 is a protein present in female laboratory mice and rats; analogues were readily detected in the following species: Musculus domesticus, M. musculus, Apodemus sylvaticus, A. agrarius, A. flavicollis, and Microtus arvalus. Immunologically, cross-reacting proteins could not be detected in the laboratory hamster and laboratory guinea pig. Maternal PAMP-1 serum levels were recorded throughout pregnancy in the two species of house mouse: M. domesticus and M. musculus. Both proteins exhibited maximum concentration at day 11 of gestation. During early pregnancy, M. domesticus females had significantly higher serum levels than those of M. musculus females.

Animals↗

PubMed1991

Negative effect on early post-implantation pregnancy and progesterone levels in mice infected with the intestinal trematode Echinostoma caproni.

Infection in mice (BALB/cABom) with the intestinal trematode Echinostoma caproni had a negative influence on pregnancy. The effect of the infection set in immediately following implantation (day 5 of pregnancy) resulting in fewer foetuses being present in infected mice on day 9 than in the controls. Ovulation, fertilization of eggs, and implantation itself were obviously not impaired. The infected mice had significantly lower serum progesterone levels on day 5 of pregnancy than the non-infected controls. It is speculated that the progesterone levels in the infected female mice were too low to secure early post-implantation gestation.

Animals↗

PubMed1991

Experimental candidosis in pregnant mice.

Pregnant mice were challenged intravenously with doses of 1 x 10(3)-1 x 10(7) Candida albicans blastospores, and from postmortem histopathology it was found that C. albicans had a propensity for localization in the murine placenta. At the highest dose, blastospores, hyphae and pseudohyphae were randomly located in the foeto-placental units, whereas proliferation of fungi at lower doses started in the rim of the placental disc, after which it spread along Reichert's membrane and/or the splanchnopleure, eventually attacking the foetal skin. These findings are analogous to our previous observations on the nature of Aspergillus fumigatus infection in pregnant mice.

Animals↗

PubMed1991

Pregnancy-associated murine protein-1 plasma levels during oestrus cycle, pseudopregnancy and pregnancy in the mouse.

A cyclic variation in plasma levels of pregnancy-associated murine protein-1 (PAMP-1) during the oestrus cycle in outbred Pan: Thei mice was recorded. PAMP-1 plasma levels were significantly elevated in dioestrus as compared with the three other stages of the murine oestrus cycle. Until day 7 of gestation the PAMP-1 plasma levels remained low, and no significant differences could be observed between pregnant and pseudopregnant female mice. The PAMP-1 levels increased markedly in the circulation on day 8 of pregnancy, and continued to increase until peak values were reached at day 11 of pregnancy. In the latter half of pregnancy the PAMP-1 levels declined until day 17 of pregnancy, at which stage the normal non-pregnant values were recorded.

Animals↗

PubMed1991

Effect of exogenous insulin treatment on fetal growth and maternal alpha-fetoprotein levels in pregnant mice.

The effect of exogenous insulin on the maternal serum level of alpha-fetoprotein and fetal weight was studied. Insulin was given either as one subcutaneous injection on the 13th day of pregnancy (pulse treatment) or as subcutaneous injections each day throughout pregnancy (long-term treatment). Neither of the treatment procedures resulted in a significant alteration in the average fetal weight. However, pulse treatment on the 13th day of pregnancy resulted in elevated maternal serum levels of alpha-fetoprotein and in a greater number of fetuses and larger fetal mass per animal as examined on the 18th day of pregnancy. By contrast, long-term treatment with insulin from the first day of pregnancy resulted in a lower level of maternal serum alpha-fetoprotein and in significantly lower fetal mass per animal. It is concluded that insulin treatment as such, and especially the mode of treatment, plays a crucial role for fetal growth and synthesis of alpha-fetoprotein.

Animals↗

PubMed1990

A murine model for the study of the impact of Aspergillus fumigatus inoculation on the foeto-placental unit.

Pregnant female BALB/c mice were inoculated intravenously with Aspergillus fumigatus conidia in different concentrations (1 x 10(1)-1 x 10(8)) on day 10 of pregnancy. Pregnancy was confirmed by the presence of murine alpha-fetoprotein (m-AFP) in the maternal circulation. Conidia inoculation of 1 x 10(3) and greater significantly (p less than 0.0001) resulted in abortion or placental lesions. Uterine cell infiltrations were recognized in 75% of the mice which aborted following the inoculation of 1 x 10(3) conidia or more. In the placental lesions of mice inoculated with 0.5-1 x 10(8) conidia, hyphae, haemorrhage, thrombosis, necrosis, calcification, and inflammation were regular findings. Histopathology of other maternal organs revealed that extrauterine organ lesions were closely correlated with the dose of conidia inoculated, and the following pattern of reaction was found: liver greater than lung greater than kidney greater than brain greater than heart.

Abortion, Veterinary↗

PubMed1990

Comparison of intestinal anaphylactic reactions in sensitized mice challenged with untreated bovine milk and homogenized bovine milk.

Outbred NMRI mice were sensitized for high IgE production either by subcutaneous injections of low doses of untreated bovine milk or homogenized bovine milk in combination with intraperitoneal injections of Freund's Complete Adjuvant or by oral administration of untreated or homogenized bovine milk without adjuvant. When analysed in murine passive cutaneous anaphylaxis test both types of milk resulted in production of reaginic antibodies against bovine milk proteins when given subcutaneously. When given orally, homogenized milk resulted in reagin production in 10 out of 14 mice, whereas untreated milk resulted in reagin production in only one out of 12 mice. The sensitized mice, and control mice, were orally challenged with either untreated milk, homogenized milk or 0.9% NaCl. Examination of the intestines 40 min after oral administration revealed that homogenized milk, contrary to untreated milk or 0.9% NaCl, resulted in a large increase in the mass of the proximal gut segment of mice sensitized orally with homogenized milk compared with control mice orally challenged with saline (P less than 0.001), and only mice both sensitized and challenged orally with homogenized milk showed degranulation of mast cells in the intestinal wall. By contrast, subcutaneously sensitized mice or mice sensitized orally with untreated bovine milk showed no significant intestinal reaction upon oral challenge with either homogenized or untreated bovine milk. These observations may indicate that the route of sensitization is of great importance when intestinal reactions are to be studied, and that homogenization of bovine milk may render the milk more aggressive with respect to its ability to induce intestinal reactions. The study indicates that mice may be an attractive experimental animal model for mimicking the intestinal anaphylactic reactions of cow milk-allergic humans.

Administration, Oral↗

PubMed1990

Induction of pregnancy-associated murine protein-1 in dwarf mice by human growth hormone.

Pregnancy-associated murine protein-1 (PAMP-1) could not be detected in peripheral blood of female dwarf mice (genotype dw/dw of the DW strain). By contrast the normal size females of the DW strain (genotypes +/+ and +/dw) had PAMP-1 serum levels of 18.9 AU +/- 15.7 AU/ml. Following administration of biosynthetic human growth hormone (hGH) every 2 h for 52 h PAMP-1 was detected in all dwarf females at concentrations of 16.0 AU +/- 3.3 AU/ml. The albumin levels in the circulation of DW females of normal size were significantly higher (P less than 0.05) than those of DW dwarfs, and the hGH administration did not change the serum albumin levels. The present experiment adds weight to the suggestion that the PAMP-1 serum level is regulated by GH.

Animals↗

PubMed1990

Effect of growth hormone on secretion of pregnancy-associated murine protein-1 (PAMP-1) in female and male rats.

The effect of 2 daily injections of human growth hormone (hGH) on serum levels of pregnancy-associated murine protein-1 (PAMP-1) was analysed in male and female Mol:WIST rats. In untreated control male rats the PAMP-1 level in the circulation is below the detection limit of rocket immunoelectrophoresis whereas females have a high serum level of PAMP-1. hGH treatment of male rats resulted in a dose-dependent increase in PAMP-1 concentration, whereas a similar treatment of female rats resulted in a significant decrease of the PAMP-1 concentration in serum. Methylprednisolone treatment either alone or in combination with hGH had no significant effect on the level of PAMP-1 in serum of male rats. It is concluded that the normal sexually determined different secretion pattern of PAMP-1 can be modified towards an intermediate pattern by administration of exogenous hGH.

Animals↗