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Biomedical subjects

H Meyer

Publications and source records attributed to H Meyer.

At least 271 records · Page 15Linked to original sources
PubMed1993

[Control of salmonella infections in animal herds--basis for a reduction of salmonella entries into food].

Control measures against Salmonella infections in livestock are discussed on the basis of an epidemiological classification of Salmonella serovars important for animals and/or humans. Special attention is paid to immunoprophylaxis carried out additionally to generally accepted zoo sanitary measures. Available Salmonella vaccines are described and their major characteristics discussed briefly. Schemes are presented for the administration of vaccines in cattle, pigs and poultry. They have to be rationally integrated into general control concepts. They should serve as recommendations for the practical use in animal farms. It is concluded that given consequent combination and enforcement of the described measures the occurrence of Salmonella serovars important for animals and/or humans can be reduced decisively in livestock, thus minimizing introduction into the food chain for the sake of improved consumer protection.

Animals↗
PubMed1993

[Granulated carrots (Daucus carota) in dog nutrition].

In feeding and balance trials with dogs (4) dried, ground carrots were tested in addition (30%) to a basic dry food (rice, corn gluten, fish meal and supplements). The palatability of both mixtures was good: fecal water losses were increased after feeding the carrots. Apparent digestibilities of organic and inorganic matter, especially sodium and potassium (not phosphorus), decreased. Digestibility of carrots was calculated to reach 70% with 1.2 MJ of digestible energy per 100 g dry matter. Reduced fecal pH (6.9-->6.1), higher lactate concentrations and increasing excretion of volatile fatty acids were seen as results of the stimulated bacterial metabolism in the colon. Diurnal pattern of breath hydrogen exhalation was similar in both periods: renal excretions of phenol, indican, and nitrogen were significantly reduced after supplementation with carrots as compared to control period.

Animal Feed↗
PubMed1992

[Energy intake of adult Great Danes].

Energy intake and weight development were recorded in 5 adult Great Danes kept in outdoor kennels during maintenance, pregnancy and lactation. In periods with constant weights the energy requirement was 0.96 MJ DE/kg BW0.75/d with a minimum in summer (0.82) and a maximum in winter (1.1). In pregnancy (weight gain depending on litter size 7-15 kg) energy intake (ad-lib.-feeding) was similar to maintenance. During lactation energy intake reached 1.6-1.7 MJ DE/kg BW0.75/d with a dry matter intake of 83 g/kg BW0.75/d. Pups of great litters had to be fed with milk substitute for normal weight development.

Animal Feed↗
PubMed1992

Encephalitis and chorioretinitis associated with neurotropic African horsesickness virus infection in laboratory workers. Part II. Ophthalmological findings.

Four laboratory workers developed uveitis-chorioretinitis, associated with encephalitis in 3 cases. The retinitis was characterised by haemorrhages and areas of retinal oedema, most marked over the posterior polar regions, and was associated with exudative retinal detachments. The lesions progressed over weeks and showed a severe retinal arterial vasculopathy with arteriolar narrowing, ghost vessel formation and the development of optic atrophy. The picture in 2 of the patients resembled that of the acute retinal necrosis syndrome (ARN). Antibodies to African horsesickness (AHS) virus were detected. The serology for AHS virus was positive in all 4 patients as well as in 5 of 15 laboratory workers from the same facility who were clinically and ophthalmologically normal. This is to our knowledge the first description of subclinical and probable clinical neurotropic AHS virus infection in man. AHS is a hitherto-unrecognised possible cause of viral retinitis and the ARN syndrome.

Adolescent↗
PubMed1992

The switch of tau protein to an Alzheimer-like state includes the phosphorylation of two serine-proline motifs upstream of the microtubule binding region.

The paired helical filaments (PHFs) of Alzheimer's disease consist mainly of the microtubule-associated protein tau. PHF tau differs from normal human brain tau in that it has a higher Mr and a special state of phosphorylation. However, the protein kinase(s) involved, the phosphorylation sites on tau and the resulting conformational changes are only poorly understood. Here we show that a new monoclonal antibody, AT8, records the PHF-like state of tau in vitro, and we describe a kinase activity that turns normal tau into a PHF-like state. The epitope of AT8 is around residue 200, outside the region of internal repeats and requires the phosphorylation of serines 199 and/or 202. Both of these are followed by a proline, suggesting that the kinase activity belongs to the family of proline-directed kinases. The epitope of AT8 is nearly coincident with that of another phosphorylation-dependent antibody, TAU1 [Binder, L.I., Frankfurter, A. and Rebhun, L. (1985) J. Cell Biol., 101, 1371-1378], but the two are complementary since TAU1 requires a dephosphorylated epitope.

Alzheimer Disease↗
PubMed1992

Endogenous and environmental factors influence 35S promoter methylation of a maize A1 gene construct in transgenic petunia and its colour phenotype.

30,000 transgenic petunia plants carrying a single copy of the maize A1 gene, encoding a dihydroflavonol reductase, which confers a salmon red flower colour phenotype on the petunia plant, were grown in a field test. During the growing season plants with flowers deviating from this salmon red colour, such as those showing white or variegated phenotypes and plants with flowers exhibiting only weak pigmentation were observed with varying frequencies. While four white flowering plants were shown at the molecular level to be mutants in which part of the A1 gene had been deleted, other white flowering plants, as well as 13 representative plants tested out of a total of 57 variegated individuals were not mutants but rather showed hypermethylation of the 35S promoter directing A1 gene expression. This was in contrast to the homogeneous fully red flowering plants in which no methylation of the 35S promoter was observed. While blossoms on plants flowering early in the season were predominantly red, later flowers on the same plants showed weaker coloration. Once again the reduction of the A1-specific phenotype correlated with the methylation of the 35S promoter. This variation in coloration seems to be dependent not only on exogenous but also on endogenous factors such as the age of the parental plant from which the seed was derived or the time at which crosses were made.

Alcohol Oxidoreductases↗
PubMed1992

Immunohistological and immunoelectron microscopic identification of TNF alpha in normal human and murine epidermis.

The presence, distribution and cellular localization of tumour necrosis factor-alpha (TNF alpha) were investigated in normal human and murine epidermis using immunohistological and immunoelectron microscopic methods with monoclonal and polyclonal antibodies. The immunostaining revealed an intercellular plasma membrane and cytoplasmic labelling of the epidermal keratinocytes, but no labelling of Langerhans cells, melanocytes and Merkel cells. Large amounts of TNF alpha were regularly found in the sebaceous glands. These findings demonstrate that epidermal keratinocytes and especially sebocytes produce and release TNF alpha and that this keratinocyte-derived cytokine may be important for the structural and functional homeostasis of normal epidermis.

Adult↗
PubMed1992

Rapid identification and differentiation of the vaccine strain Rac H from EHV 1 field isolates using a non-radioactive DNA probe.

A method for rapid differentiation between the EHV 1 live vaccine strain Rac H and field isolates is described. Total DNA was isolated from virus-infected small scale cell cultures. DNA fragments digested with restriction endonuclease BamHI were separated, transferred and immobilized on filter membranes. A Digoxigenin-labeled probe derived from EHV 1 was used for hybridization. This probe hybridized specifically to sequences of the inverted terminal repeat region which in case of Rac H include a deletion of 0.8 kb. By comparing the different migration patterns after blot hybridization it could be shown that in 65 isolates from cases of abortion the live vaccine strain Rac H was not involved.

Abortion, Veterinary↗
PubMed1992

Glycoprotein gp116 of human cytomegalovirus contains epitopes for strain-common and strain-specific antibodies.

Glycoprotein gp116 of human cytomegalovirus (HCMV) is a target for neutralizing antibodies. Gp116 is a component of the gCI complex which consists of gp58 and gp116. Like its homologue, glycoprotein B of herpes simplex virus type 1, gp116 contains a highly antigenic region in the N-terminal part of the molecule, between amino acids 28 and 84. Prokaryotic expression plasmids and synthetic peptides were used to define binding sites for mouse and human monoclonal antibodies (MAbs) as well as HCMV convalescent sera. Site I, located between amino acids 68 and 77, contains an epitope recognized by the human MAb C23, which is capable of neutralizing HCMV independently of complement and the site is conserved between HCMV strains. Of HCMV-positive human sera, 53% recognized site I. Site II was mapped using mouse MAbs as well as human sera. It is located between residues 50 and 54, an area which is not conserved between strains AD169 and Towne, the two laboratory strains of known sequence. Strain-specific antibodies were detected in 25% of human sera. Site II-specific antibodies, purified from human sera by affinity chromatography, were found to be incapable of neutralizing HCMV in tissue culture.

Amino Acid Sequence↗
PubMed1992

Cytotoxicity of cyanobacterium Microcystis aeruginosa.

Cytotoxic effects of crude extracts and fractions of the purification steps towards Microcystin-LR (MCYST-LR) were investigated in vitro. Cytotoxicity was evaluated by measure of lactate dehydrogenase liberation of Chang liver cells and by hemolysis. Crude extracts of strain PCC 7806 damaged the cells within a few minutes. In contrast, MCYST-LR did not show any detectable cytotoxic effects. The cytotoxic activity could be related to a heat-labile substance with a molecular weight of about 30,000 Da.

Animals↗
PubMed1992

Heart transplantation at the Heart Center North Rhine-Westphalia.

Since 1989, 427 heart transplants were performed at our center, limited only by donor availability, not by moderating donor criteria. Therefore, an increasing number of possible recipients was bridged with mechanical circulatory support systems. Immunosuppression was based on double-drug therapy (CsA, Aza) without steroid maintenance if possible and without mono- or polyclonal antibody prophylaxis. Monitoring adult transplant patients was based on endomyocardial biopsies only during the first 12 months posttransplant. In the pediatric group, only noninvasive diagnostic procedures were performed. Our present 1- and 3-year survival rates for heart transplant patients are 85% and 78%, respectively. We believe that only centers performing approximately 1,000 routine open-heart surgery procedures per year should be allowed to perform heart transplantation, with a minimum of 25 procedures per year (5). Our goal is to start our heart-lung and lung transplant programs in the near future. Our research interests are mainly in the field of postoperative monitoring, induction of immune tolerance, and in establishing a method to determine an individual immunosuppression protocol for each patient (6).

Academic Medical Centers↗
PubMed1992

[The effect of a different energy supply on the growth intensity and skeletal development of growing Great Danes. 2. Effect on insulin-like growth factor I and on thyroid hormones].

In an experiment with 13 growing Great Danes (littermates) fed ad libitum (4 dogs) or restrictively (70% of ad libitum energy intake; 9 dogs), concentrations of insulin-like growth factor I (IGF-I), 3,5,3'-triiodothyronine (T3) and thyroxine (T4) were measured in blood samples until the age of 6 months. In the ad libitum fed group, levels of T3 and T4 were partially and of IGF-I were significantly (p < 0.01) elevated as compared with the control dogs. Postprandial changes of IGF-I were absent in growing Great Danes as well as in a reference group of 3 adult beagles. Increased concentrations of IGF-I, T3 and T4 could be causally related to osteochondrosis, which frequently occurs in intensively fed dogs.

Animal Feed↗