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Biomedical subjects

M Brack

Publications and source records attributed to M Brack.

At least 37 records · Page 2Linked to original sources

Alveolar hydatidosis (Echinococcus multilocularis) in a captive rhesus monkey (Macaca mulatta) in Germany.

A naturally occurring E. multilocularis infection in an 11-year-old female rhesus monkey is described. The infection most probably was acquired from foxes of the Göttingen area through contaminated branches or foliage taken from the nearby forest. The most severely affected organs were the liver and the lung, A limited serological survey using the Em2plus ELISA revealed 5 more animals which so far remain clinically healthy as possibly infected.

Animals↗

Eikenella corrodens-caused botryomycosis-type pneumonia in a barbary ape (Macaca sylvanus).

An 18-year-old female barbary ape in a safari park died from a mixed bacterial infection. Staphylococus aureus was isolated from a purulent necrotic mastitis and from a chronic purulent granulomatous sialoadenitis of the sublingual glands, Eikenella corrodens from a botryomycosis-type pneumonia. As judged by histopathology, mixed infection of S. aureus and E. corrodens was present in the sialoadenitis, and E. corrodens botryomycosis-type bacterial colonies were also present in the pancreatic parenchyma, though here no bacteriological isolation was attempted. A generalized amyloidosis, and especially pancreatic islet amyloidosis, probably indicated an altered immunological competence.

Animals↗

Pulmonary histiocytosis in tree shrews (Tupaia belangeri).

Granulomatous lesions similar to those of pulmonary histiocytosis in rats developed spontaneously in the lungs of captive tree shrews. Incidence peaked in 3-year-old tree shrews. Sex dependency was not observed, and development of the granulomas was unrelated to experimental procedures because the lesions were observed in animals from the breeding stock as well. The granulomas consisted of amorphous material, foam cells, and a few foreign body-type multinuclear giant cells; they also contained acicular clefts, often with some fibrous material. Alveolar septa within and adjacent to the granulomas were thickened in most instances, but did not contain inflammatory cells in appreciable numbers or amyloid. Only traces of cholesterol and calcium were detected in the amorphous material; neutral fat was stored in the foam cells and the amorphous masses. Fibers without birefringency were documented by polarization and scanning electron microscopy in the vicinity of granulomas, which in energy-dispersive X-ray microanalysis consisted mostly of calcium, but lacked silicon.

Animals↗

Suspected dermatophilosis in an adult orangutan (Pongo pygmaeus pygmaeus).

An adult female Bornean orangutan (Pongo pygmaeus pygmaeus) had a pruritic, vesicular skin disease, particularly of the extremities, trunk, and face. Over a 2-yr course, symptoms resolved only transiently after corticosteroid treatment. Antibiotic treatment and withdrawal of all corticosteroids resulted in complete recovery of the animal and return to normal activity patterns. On the basis of the dermal histopathologic lesions, Dermatophilus congolensis was suspected as the causative organism, although subsequent cultivation was not attempted because of the stress additional procedures would have caused to the orangutan.

Actinomycetales↗

Apolipoprotein E polymorphism does not predict risk of restenosis after coronary angioplasty.

A recent report has suggested that the E4 allele of apolipoprotein (apo) E increases the risk of restenosis after percutaneous transluminal coronary angioplasty (PTCA) and also that it interacts synergistically with the deletion (D) allele of the angiotensin-converting enzyme (ACE) to increase the risk sixteen-fold. To investigate this further, we genotyped 231 subjects with successful PTCA who underwent planned repeat angiography at 4 months to assess the degree of restenosis. Subjects carrying the apo E4 allele (n = 71) were well matched with non-carriers (n = 160) for clinical and pre- and post-PTCA angiographic features. We found no increase in either apo E4 allele frequency (18.4% versus 15.6%, P = 0.42) or apo E4 homozygosity (2/106 versus 5/125, P = 0.30) in those with restenosis compared with those without. The relative risk of restenosis for apo E4 carriers was 1.11 (95% CI = 0.87-1.42). In apo E4 carriers, restenosis frequency was similar in those also carrying the ACE D allele and those without (28/55 (50.9%) versus 9/16 (56.2%), P = 0.71) and there was no significant increase in restenosis risk in carriers of both the apo E4 and ACE D alleles compared to the rest (odds ratio 1.30, 95% CI 0.68-2.50, P = 0.39). We conclude that in our cohort, the apo E4 allele does not either independently or acting synergistically with the ACE D allele increase the risk of restenosis after PTCA, and that apo E genotyping will not be a useful predictor of risk before the procedure.

Alleles↗

Tumors of the respiratory tract observed at the German Primate Center, 1978-1994.

Eight spontaneous pulmonary tumors (four bronchiolar tubular adenomas, two bronchiolar adenocarcinomas, two squamous-cell carcinomas) occurred in a total of 54 adult tree shrews (Tupaia belangeri) of the GPC colonies between 1978 and 1994. The adenomas and adenocarcinomas consisted of tubularly or trabecularly arranged cuboidal to cylindrical cells interspersed with some PAS-positive goblet cells, thus resembling the epithelial lining of respiratory bronchioles of tree shrews. The two squamous-cell carcinomas probably originated from the pulmonary alveoles. Three more pulmonary tumors (one small-cell carcinoma, one bronchial adenoma, one squamous-cell carcinoma) developed in 409 adult callitrichids of the GPC colonies during the same period, and one more bronchial adenoma was observed in a common marmoset (Callithrix jacchus) of another colony located in Göttingen. With regard to the adenomas and squamous-cell carcinomas, a similar cellular origin with the three shrews is assumed. The small-cell carcinoma possibly developed from the bronchial epithelium, provided a pathogenesis parallel to that of human small-cell carcinoma is suggested. Four of the tree shrew pulmonary adenomas/adenocarcinomas and the small-cell Ca were macroscopically visible as yellowish-grey nodules of 1 mm x 1 mm to 15 mm x 15 mm diameter, predominantly involving the main lobes (2 x right main lobes, 2 x left main lobes, 1 x all lobes). The pulmonary tumors of the other animals were below macroscopical detectability.

Adenocarcinoma↗

Gongylonematiasis in the common marmoset (Callithrix jacchus).

Two cases of gongylonematiasis in common marmosets of two research facilities in Germany are reported. The helminthiasis was transmitted from colony A to colony B by one infected female and within colony B by cockroaches (Blatella germanica). Four of 40 cockroaches examined in colony B were infected with rhabditiform larvae. Clinical signs of disease in the infected animals consisted of intense itching and scratching of the edematous and slightly hyperemic perioral tissues. Histologically the adult helminths lodged predominantly in the mucous membranes of the upper and lower lips; they were less frequently present in the labial cutaneous parts or in the tongue and could not be seen in the esophageal wall, bronchi, or abdominal organs. The helminthic infection probably caused minor to moderate mixed inflammatory infiltrates of the periesophageal connective tissues and intense inflammation of the deep lingual muscular tissues. Lesions of the mucosal membranes of the lips and tongue had predominant accumulations of neutrophilic granulocytes, lymphocytes, and mostly degranulated mast cells with only a few eosinophilic granulocytes. In the cutaneous part of the lips multifocal microabscesses were considered to be secondary lesions from the intense scratching.

Animals↗

Insertion/deletion polymorphism in the angiotensin-converting enzyme gene and risk of restenosis after coronary angioplasty.

Early restenosis in over 30% of cases limits the benefits of percutaneous transluminal coronary angioplasty (PTCA). The mechanisms that underlie restenosis are uncertain, although experimental evidence suggests that the renin-angiotensin system is involved in the vascular response to angioplasty. An insertion(I)/deletion(D) polymorphism in the angiotensin-converting enzyme (ACE) gene, which influences plasma ACE level, has been associated with an increased risk of myocardial infarction in those with the DD genotype. To investigate whether this polymorphism influences the risk of restenosis after PTCA, 233 patients who underwent single-vessel angioplasty in the Subcutaneous Heparin and Angioplasty Restenosis Prevention (SHARP) study were genotyped for the I/D polymorphism and pre-PTCA, post-PTCA, and 4-month clinical and quantitative angiographic data were compared in the three genotype groups. The groups, (II 53, ID 117, and DD 63) were well matched for baseline clinical and both pre- and post-PTCA angiographic features. At 4-month follow-up there was no significant difference between the genotype groups with respect to any of the quantitative angiographic criteria of restenosis: minimal luminal diameter at the site of the angioplasty (DD 1.35 [SE 0.10] mm, ID/II 1.43 [0.05] mm, difference -0.08 [95% CI -0.30 to 0.14]), numbers of subjects with more than 50% diameter stenosis (DD 49%, ID/II 46%, relative risk 1.06 [0.79 to 1.43]), or the number of subjects with more than 50% loss of the acute diameter gain after PTCA (DD 54%, ID/II 43%, 1.26 [0.94 to 1.67]). Likewise, there was no difference in the number of subjects with angina or a positive exercise stress test. We conclude that, in patients undergoing elective PTCA, the I/D polymorphism in the ACE gene does not influence the extent of restenosis, and typing for the polymorphism will not be a useful predictor of risk before the procedure.

Adult↗

Microsatellite polymorphisms reveal phylogenetic relationships in primates.

We amplified, via PCR, DNA segments from intron 1 of the tyrosine hydroxylase gene (TH01) and intron 40 of the von Willebrand factor gene (VWA) in ten nonhuman primate genera. In humans both introns contain polymorphic microsatellites with tetrameric repeats. Compared to the allelic ranges in human populations relatively short repeat arrays could be detected for the nonhuman primates typed, presumably reflecting an ancient precursor state at both microsatellite loci. Furthermore, our results provide evidence for an association of the average number of repeats present in different primate genera and their divergence time from man. DNA sequencing of VWA orthologues revealed a relatively high variability in the arrangement of repeats in the 5'-repeat arrays, the generation of which could probably be explained by polar mutational events.

Animals↗

Distribution of human endogenous retrovirus HERV-K genomes in humans and different primates.

The distribution of the human endogenous retrovirus (HERV)-K genome was investigated by Southern-blot analyses using a HERV-K-env DNA probe. With the exception of one DNA-sample, obtained from a Chinese individual in whom an amplification of HERV-K was detected, Southern-blot analyses yielded identical hybridization patterns with DNA from peripheral blood lymphocytes of 37 normal healthy blood donors, with DNA from six tumor cell lines, or with 23 DNA samples prepared from various carcinoma tissues. To elucidate whether the integration of HERV-K genomes into the primate lineage occurred as a single event or as an integration with later expansion, we further examined the evolutionary history of HERV-K by Southern blot analyses with DNA samples from different primate species. We detected HERV-K genomes in Macaca mulatta and Macaca silenus, which represent Old World monkeys, but not in prosimians (Galago demidovii) and New World monkeys, represented by Saguinus fuscicollis, Saguinus oedipus, and Callithrix iacchus. Thus, we assume that the infection of the primate lineage with HERV-K had occurred after the divergence of New World and Old World monkeys, but before the evolutionary expansion of large hominoids. In contrast to the apparent lack of HERV-K-env sequences in DNA from tissue of the New World monkey Saguinus oedipus (cotton-top marmoset), we found HERV-K-DNA in the B95-8 cell-line, which is a Saguinus oedipus leukocyte cell-line, immortalized in vitro by Epstein-Barr virus (EBV) and cultivated in human cells. It may be speculated that HERV-K-DNA or HERV-K-particles were introduced into these cells during in vitro transformation with EBV.

Animals↗

Ultrastructural and histochemical mesangial alterations in Callitrichid IgM nephropathy (primates: platyrrhina).

The ultrastructural and histochemical alterations during different stages of spontaneously occurring IgM nephropathy in Callitrichidae were determined. Callitrichid IgM nephropathy was classified according to the light microscopic sequence of the mesangial lesions in the individual glomeruli. In minimal disease and axial proliferation mesangial cells and mesangial matrix were symmetrically increased, whereas in panmesangial disease matrix deposition exceeded the cellular responses. However, ultrastructural matrix changes such as deposition of electron-dense particles, dilatation of the matrix channel system, and slightly increased collagen fiber expression were present also in minimal disease and axial proliferation. Histochemically collagen I and III phenotypes could only be verified in glomerular sclerosis, at that time accompanied by diminution of collagen IV. The mesangial cellular lesions, in contrast, were very limited. The numerical increase in mesangial cells was associated with increased bleb formation and increased heterolysosome contents, whereas the amount of microfilaments was never increased.

Animals↗

Lectin histochemistry and carcinoembryonic antigen in spontaneous colonic cancers of cotton-top tamarins (Saguinus oedipus).

The glycoconjugate-binding properties and the expression of carcinoembryonic antigen in colonic cancers of cotton-top tamarins at the German Primate Center are described. Deviating from findings in non-tumorous colonic epithelia of cotton-top tamarins was the presence of UEA-, SBA-, or DBA-binding sites in the infranuclear cytoplasm of colonic epithelial cells, staining of entire cells, and the occurrence of subepithelial extracellular glycoconjugates in and adjacent to colonic cancers. Carcinoembryonic antigen, which normally was limited to the fuzzy coat of the colonic epithelium, was demonstrated in the cytoplasm of the cancer cells.

Adenocarcinoma↗

Callitrichid IgM-nephropathy--an old age-related disease?

In 185 callitrichids of exactly known age the occurrence of mesangial IgM-deposits and mesangial lesions has been evaluated. Mesangial IgM-deposits were observed already in early infancy, at that time without morphological sequelae. Signs of mesangial lesions were first observed in a 3-months old animal and with a sharp increase of mesangial lesions between 4 months and one year of age all suggesting an onset early in life. In contrast in higher age groups a significant number of animals suffered from glomerulosclerosis without IgM deposits, which could be interpreted as 'old age nephropathy' independent from IgM-nephropathy.

Aging↗

Angiostrongylus costaricensis in a black-eared marmoset.

A case of Angiostrongylus costaricensis in a captive C. penicillata in a German zoological garden is described. Clinical symptoms were lacking, the morphological lesions consisted of intestinal granulomas harbouring rhabdidiform larvae. The adult worms were present in the ileo-caecal branches of the mesenteric artery.

Angiostrongylus↗