Biomedical subjects

J Hau

Publications and source records attributed to J Hau.

120 records · Page 7Linked to original sources

PubMedDate not supplied

Accumulated means analysis: a novel method to determine reliability of behavioral studies using continuous focal sampling.

During the past decade, the behavioral needs, and especially the social needs, of laboratory animals have received increasing attention. New captive care guidelines have been developed, and these advocate group housing of laboratory animals whenever possible and appropriate. Analyses of behavioral observations are commonly used to assess the effects of experimental manipulations on behavioral responses. In studies of animal welfare, stress levels and effects on well being can be measured in this manner. Collecting the proper amount of data both to allow statistical analyses and to optimize time investment in data collection is a practical concern in behavioral research. The aim of the present study was to develop a simple method to estimate how much behavioral data should be collected in order to achieve a preset level of reliability across observations. This paper examines the behavior of 12 rhesus monkeys (Macaca mulatta) housed in two small social groups. Each monkey was observed for a total of two hours in 10 minute observation periods spread over 12 days. Accumulated Means Analysis, in which the accumulated mean for a behavior across successive observation sessions must meet several criteria, is proposed as a method to assess reliability across observations, thereby providing information concerning the optimum number of observational data sessions that need to be collected. The data in this study indicate that this optimum number of observations varies with the behavior being measured and with the group observed, as does the value of the Accumulated Means Analysis technique. Six hours of observation of rhesus macaques may be sufficient to provide the type of simple, yet reliable time budget (for a specific window of time) needed by those managing groups of primates. Accumulated Means Analysis should be applicable to behavioral data collected during multiple time periods on other non-human primate species, both in captivity and in the field.

Animal Welfare↗

PubMedDate not supplied

Oral immunisation of chickens using cholera toxin B subunit and Softigen as adjuvants results in high antibody titre in the egg yolk.

Oral immunisation by gavage of laying hens with human immunoglobulin G (IgG) combined with a number of potential adjuvants was performed. The resulting immunospecific egg yolk (IgY) antibodies were quantified by ELISA. The following adjuvants were tested: A Poly(lactide-co-glycolide) (PLG) microspheres, Cholera toxin B-subunit (CTB), CTB conjugated with glutaraldehyde, Dimethyl dioctadecyl ammonium bromide (DDA), and Softigen (pegylated C8/C10 mono/di glyceride). Hens in a positive control group were immunised with human IgG in saline emulsified with an equal volume of Freund's Incomplete Adjuvant. High titres of immunospecific IgY antibodies against human IgG were recorded in the eggs from the chickens immunised orally with the antigen combined with glutaraldehyde conjugated CTB and in the chickens immunised with the antigen combined with Softigen. The present results show that invasive technique related stress could be eliminated/reduced in polyclonal antibody producing animals.

Adjuvants, Immunologic↗

PubMedDate not supplied

Fetal antigen 1 (FA1) in the adult rat adrenal gland, ovary and pituitary gland.

Fetal antigen 1 (FA1) is a circulating glycoprotein containing six epidermal growth factor (EGF)-like repeats. FA1's larger membrane-bound precursor is defined by the cDNAs referred to as either human delta-like (dlk) or human adrenal specific cDNA, pG2. In rodents FA1 has also been studied under the names of preadipocyte factor 1 (Pref-1), and zona glomerulosa-specific factor (ZOG). FA1 is abundantly expressed in fetal tissues, but in the mature cells of the adult organism the tissue presence of the protein seems to be restricted to neuroendocrine tissues. The present study demonstrates FA1 localisation in endocrine tissues of the adult female rat in which the protein was found present in the medulla and the zona glomerulosa of the cortex of the adrenal glands, in the pars distalis of the adenohypophysis, and in the ovarian granulosa lutein cells. No staining was found in the pancreas, which is in contrast to what has been described in the human.

Adrenal Glands↗

PubMedDate not supplied

Systemic immune response of young chickens orally immunized with bovine serum albumin.

The efficacy of oral immunization, with and without commercial adjuvants, to mount a systemic immune response in young chickens was studied. Bovine serum albumin (BSA) mixed with a pegylated C8/C10 mono/di-glyceride, (Softigen), or Cholera toxin B-subunit (CTB), administered orally by gavage to 15-day-old chickens resulted in circulating immunospecific anti-BSA IgG, IgM and IgA antibodies. Continuous 5-day oral administration of BSA without adjuvant also resulted in immunospecific IgM and IgA antibodies in the circulation of chickens first immunized at 15 days of age; and immunospecific antibodies of all three classes in chickens first immunized when they were 22 days old. IgG and IgM serum concentrations were more than 4 to 10 times higher, respectively, in CTB- and Softigen-treated chickens as compared to chickens immunized without adjuvants. The IgA response in the orally immunized chickens seemed unaffected by CTB and Softigen. The antibody concentrations in chickens immunized subcutaneously with BSA emulsified in Freund's Incomplete Adjuvant (FIA) were approximately 10 times higher than those of the chickens orally immunized using CTB and Softigen.

Administration, Oral↗

PubMedDate not supplied

Effect of extra-genital Schistosoma mansoni and Echinostoma caproni infections on serum levels of pregnancy-associated murine protein-1 during murine pregnancy.

Maternal plasma levels of pregnancy-associated murine protein-1 (PAMP-1) were measured by rocket immunoelectrophoresis in BALB/cABom mice experimentally infected with the two intestinal parasites Schistosoma mansoni and Echinostoma caproni. In the first half of pregnancy the PAMP-1 level was significantly lower in the infected females compared with the healthy controls, indicating that PAMP-1 is not essential for implantation and early gestation. In the latter half of pregnancy a rapid increase in the plasma levels of PAMP-1 in the infected females was recorded. This might suggest that pituitary GH secretion is restored in the infected animals during the second half of gestation.

Animals↗

PubMedDate not supplied

Murine mycotic placentitis produced by intravenous inoculation of conidia from Aspergillus fumigatus.

Primipregnant BALB/cABom mice were challenged intravenously with 1 x 10(5) Aspergillus fumigatus conidia on day 10 of pregnancy. Histopathological examination of the foeto-placental units and extrauterine organs from the mice revealed hyphal growth restricted to the foeto-placental unit. In the foeto-placental unit the growth of hyphae was first established on Reicher's membrane next to the periphery of the placental disc. Subsequently hyphae spread along and through the extrafoetal membranes, finally reaching the foetus. In the terminal stage of infection mycosis also ensued in the placental discs. In conclusion, A. fumigatus was found to have a propensity for infecting the murine foeto-placental unit, resulting in mycotic placentitis. This series of events seems comparable to the progression of the spontaneous disease in cattle. Consequently, the pregnant mouse seems applicable as an animal model for the study of mycotic placentitis due to A. fumigatus, which in most countries is of great importance in cattle breeding.

Animals↗

PubMedDate not supplied

Suppression of humoral antibody response during pregnancy in mice.

Fifty female BALB/cA mice were allocated to four groups. The mice of groups 1 and 3 were mated with male BALB/cA mice, whereas groups 2 and 4 served as unmated control groups. The mice of groups 1 and 2 received a primary immunization (100 micrograms ovalbumin in Freunds Complete Adjuvant) and the first booster immunization (100 micrograms ovalbumin in sterile saline) prior to mating. Eight days after mating, the mice of groups 1 and 2 received the second booster immunization. The mice of groups 3 and 4 received the primary immunization ten days after mating in group 3 and one booster injection five days later. At the end of the immunization period the individual serum titres of precipitating antibodies against ovalbumin were determined using a line-immunoelectrophoretic assay. Groups 1 and 2 showed no significant difference in the titres of precipitating antibodies against ovalbumin, indicating that the secondary antibody response was not generally suppressed during pregnancy. However, the pregnant mice of group 3 produced significantly lower titres of precipitating antibodies against ovalbumin as compared with the control mice of group 4 (P less than 0.01), demonstrating a suppression of the primary antibody response during pregnancy.

Animals↗

PubMedDate not supplied

Monitoring of murine feto-placental growth by pregnancy-specific serum proteins in an experimentally induced fetal growth retardation model.

Fetal growth retardation was induced in 14 day pregnant female mice by ligation of the uterine arteries. Maternal serum levels of pregnancy-associated murine protein-2 (PAM-2) and murine alpha-fetoprotein (m-AFP) were recorded. The ligation resulted in a reduction in fetal growth and a corresponding decrease in maternal circulatory m-AFP, whereas placental growth and maternal circulating PAM-2 were not significantly affected.

Animals↗

PubMedDate not supplied

Reagin production in mice: effect of subcutaneous and oral sensitization with untreated bovine milk and homogenized bovine milk.

Subcutaneous and oral sensitization with untreated bovine milk and homogenized bovine milk in mice was analyzed in two different sensitization schemes--a low dose and a high dose scheme. Homologous murine passive cutaneous anaphylaxis test was used to measure the titres of reagins (IgE and IgG1). Subcutaneous and oral sensitization with low doses of homogenized milk induced production of higher titres of IgE than sensitization with high doses of homogenized milk. By contrast, sensitization with both low and high doses of untreated bovine milk resulted in very low or undetectable IgE titres. The results indicate that homogenization of milk increases the efficacy of inducing IgE production in mice. Some possible implications of these results with respect to clinical allergy are discussed.

Animals↗

PubMedDate not supplied

Quick freezing of mouse embryos: freezing of inbred strains and 2- and 4-cell embryos by vitrification.

Murine embryos of mice of four different inbred strains and one hybrid strain were evaluated for their ability to survive quick freezing by post-thaw in vitro development. The embryos were transferred to an equilibration medium [10% 1,2-propanediol and 20% glycerol in modified PBS (mPBS)] for 10 minutes and frozen in a vitrification medium (25% glycerol and 25% 1,2-prapanediol in mPBS) by direct lowering into liquid nitrogen. Following thawing at 30 degrees C, dilution in 1 M sucrose in mPBS and washing in mPBS the embryos were cultured, and development was evaluated 24-28 hours later. The number of fertilized eggs obtained by superovulation differed among the strains. The survival rates evaluated by in vitro cultivation of the post-thawed inbred embryos varied from 50-85% depending on the genotype, whereas the normal live offspring from transfer of frozen-thawed embryos to recipient females confirms that the quick freezing method is an applicable method for storage of genetically defined mouse strains and stocks. The quick freezing technique was applied on 4- and 8-cell (day-3) mouse embryos of hybrids. The in vitro development of frozen thawed 4- and 8-cell embryos (23% and 21% respectively) was found to be significantly lower than that of frozen thawed morulae (89%). Permeation in glycerol-solutions before equilibration significantly increased survival of 4- and 8-cell embryos (66% and 77% respectively). By the use of dimethylsulfoxid (DMSO) in the permeation solutions an even higher survival rate was obtained in the cryopreservation of 8-cell mouse embryos (95%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

Assessment of lacrimal IgA as a potential parameter for measurement of long term stress in poultry.

This study, considering the stress of caging on laying hens, looks at the possible use of a product of the immune system; immunoglobulin A (IgA), as a representative measure of the effect of this chronic stress on the immune system of birds. Recording of serum corticosterone served as a traditional measure of stress. The study also considers the possibility of using IgA from the tears as a noninvasive source of samples. Lacrimal IgA is easily accessed by glycerol induction and measured by rocket immunoelectrophoresis. The amount of IgA in tears as well as in serum and possibly the synthesis of IgA seems to be affected by high levels of plasma corticosteroids. Lacrimal IgA levels vary independently of the IgA levels in plasma. It can be concluded that lacrimal IgA may be a useful marker of the effect of stress in poultry. Further studies are needed to facilitate a better understanding of the biological mechanisms that are involved, and to further examine IgA's usefulness as a long-term stress parameter.

Adrenal Glands↗

PubMedDate not supplied

Immunoglobulin G in the developing oocytes of the domestic hen and immunospecific antibody response in serum and corresponding egg yolk.

The concentration of Immunoglobulin G (IgG) in developing oocytes from normal chickens was measured by ELISA. The concentration was similar in oocytes ranging in size from 6 mm to 38 mm, which is in the last stage of development before ovulation. The concentration of immunospecific IgG was similar in corresponding serum and yolk samples in chickens immunised with human IgG, and a significant linear correlation between response of a specific antibody in the serum and corresponding egg yolk was found. The serum antibody level had to reach a certain level before specific antibody appeared in the egg yolk, and the egg yolk to a certain extent reflected the serum concentration of IgG over 6 to 7 days; because this is the time it takes for the developing oocyte to grow from 6 to 35 mm in diameter.

Animals↗