Biomedical subjects
B Mayr
Publications and source records attributed to B Mayr.
[Interactions between the immune system and the psyche].
Compared to well documented studies on immunosuppression "psychologically induced immunoenhancement" is a rather neglected topic in medical literature and research, even in the new established field of psychoneuroimmunology. Starting with the premise that research questions emanating from this field and from behavioural medicine may provide critical information for understanding the phenomena of immunomodulation, evidence and illustrations of psychologically induced immunoenhancement are provided in the context of psychosocial neuroimmunomodulation. Distress-reducing interventions such as progressive relaxation training, imagery, experimentally induced short-term positive mood states and mirthful laughter enhances various aspects of immune functions, i.e., primarily the phylogenetically old paraspecific parameters. Additionally, a larger variety of emotional/psychosocial factors with potentially but yet unproved immunoenhancing effects seems to exist. In particular, enhancement of phagocytosis, NK cell and T cell response to phytohemagglutinin, decrease in the number of suppressor/cytotoxic T cells and increase in the number of circulating T helper/inducer cells in peripheral blood, and enhancement of spontaneous lymphocyte blastogenesis as well as cytokines have all been shown to be associated with the above mentioned intervention techniques.
Canine tumour suppressor gene p53--mutation in a case of adenoma of circumanal glands.
Highly conserved regions of the tumour suppressor gene p53, including the typical human tumour hot spots (codons 175, 245, 248, 249, 273 and 282), were investigated in various canine neoplasms. A mutation CGG-->TGG (arginine-->tryptophan) was detected in codon 249 in an adenoma of the circumanal gland.
Gender-specific differences of serum leptin in obese and normal-weight adolescents: studies in type-I diabetes and Turner syndrome.
The influence of exogenous insulin and estrogen substitution on serum leptin-like immunoreactivity was studied longitudinally in patients with type-I diabetes and Turner syndrome using a specific radioimmunoassay. Prepubertal, pubertal and postpubertal samples of 17 patients (9 girls, 8 boys) with type-I diabetes mellitus developing obesity were compared to those of 17 normal-weight controls matched for gender, age and diabetes duration. Six obese and six normal-weight girls with Turner syndrome were studied without hormone substitution, with ethinylestradiol alone, and with cyclic estradiol/gestagen substitution. The mean leptin levels of the girls with diabetes were two times higher than boys at all times, while insulin doses and glycemic control had no influence. In Turner syndrome estrogen substitution led to increased leptin levels only in the obese group. This study revealed that both body weight above normal and female sex steroids seem to be necessary to elevate leptin concentrations, while exogenous insulin has no effect.
ret/PTC-1, -2, and -3 oncogene rearrangements in human thyroid carcinomas: implications for metastatic potential?
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Menin mutations in patients with multiple endocrine neoplasia type 1.
Multiple endocrine neoplasia type 1 (MEN-1) is a familial cancer syndrome with parathyroid, pituitary and enteropancreatic tumors. The disease phenotype segregates with markers on chromosome 11q13. Very recently a new gene was cloned from this region and was found to carry mutations in 14 of 15 unrelated MEN-1 patients. The gene was termed menin and is predicted to code for a tumor suppressor protein of 610 amino acids, but its precise function is totally unknown. To confirm this finding we used PCR from genomic DNA and direct sequencing to analyze exons 2 through 10 of the menin gene in eight patients from four pedigrees with MEN-1 syndrome or an affected relative. We identified four different heterozygous mutations, three of them are novel: one nonsense mutation, one large deletion of 32 bp and two insertions, all of them located in exon 2. Our results confirm that patients with MEN-1 carry mutations in the menin gene.
Cytogenetic variation between four cases of feline fibrosarcoma.
Short term cultures of four feline fibrosarcomas were analysed cytogenetically. There was marked genetic heterogeneity between the four cats, each showing a different clonal abnormality. The aberrations detected were one deleted B2, one marker F1 and two reciprocal translocations, t (A2q; E3q) and t (A1q; B4p).
Serum leptin levels following hypothalamic surgery.
To study a potential alteration of hypothalamic centers involved in the negative feedback action of leptin on body weight, serum leptin levels were measured in relation to BMI in 18 patients following surgery for a hypothalamic craniopharyngioma (Ctx), and were compared to levels found in 21 patients operated for a pituitary adenoma (Ptx) or in healthy control subjects. All subjects with Ptx received rhGH replacement therapy (0.5 to 2 IU/m2/d), and serum leptin levels were followed in 3 months intervals over 24 months. Serum leptin levels in patients with Ptx were comparable to controls, whereas 7 of the 18 patients with Ctx had higher than expected concentrations for their BMI. GH treatment in Ptx subjects did not alter serum leptin levels. In 5 Ctx patients where preoperative samples were available, weight gain in parallel to an increase in serum leptin levels was observed but only minimal changes in 4 others. Our data support the role of leptin as an important marker of body weight. The rapid increase in serum leptin levels observed in some Ctx subjects suggests that early postoperative measurement of serum leptin levels may help to identify patients at risk of weight gain following hypothalamic destruction.
Cytogenetic findings in two cases of feline histiocytoma.
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Identification and purification of a family of dimeric major cold shock protein homologs from the psychrotrophic Bacillus cereus WSBC 10201.
Whole-cell protein patterns of a psychrotrophic Bacillus cereus strain from cultures grown at 7 and 30 degrees C were compared. This analysis revealed that at least three major proteins are expressed at a significantly higher rate at 7 degrees C than at 30 degrees C. The most abundant of these cold-induced proteins was a small polypeptide of 7.5 kDa, designated CspA, of B. cereus. In addition, four small proteins very similar in size to CspA were seen on both 7 degrees C and 30 degrees C two-dimensional protein gels. Immunoblot analysis using B. cereus anti-CspA antibodies indicated that the five proteins described above plus an additional sixth protein not visible on silver-stained two-dimensional gels are members of a B. cereus cold shock protein family. This hypothesis was corroborated by cloning and sequencing of the genes encoding five proteins of this family. The protein sequences deduced are highly similar and show homology to small procaryotic cold shock proteins and to the cold shock domain of eucaryotic Y-box proteins. Besides CspA, only one of the additional five CspA homologs was slightly cold inducible. In the presence of 100 mM NaCl, the two purified members of the protein family (CspA and CspE) elute as dimers at an apparent molecular mass of 15 kDa from a gel filtration column. At higher salt concentrations, they dissociate into their monomers. Their ability to bind to the ATTGG motif of single-stranded oligonucleotides was demonstrated by band shift analysis.
Serum leptin and weight reduction in female obesity.
Leptin, an adipocyte-derived hormone, induces a decrease in food intake and increases energy expenditure via hypothalamic interactions. In animal models obesity can be caused by leptin deficiency or by a dysfunction of the hypothalamic leptin receptor. Using a radioimmunoassay for the determination of leptin in human serum, we measured serum leptin levels in 227 otherwise healthy normal weight (N = 78; body mass index = 16.1-27.7 kg/m2) or obese women (N = 149; body mass index = 27.8-56.7 kg/m2). Fifty-three subjects were followed over a period of 12 weeks under weight reduction (800 kcal/day) and a subgroup of 33 for another 13 weeks after termination of the diet. Body mass index and serum leptin concentrations were measured longitudinally and compared to female controls not under diet. Under baseline conditions, log serum leptin levels were positively related to body mass index with a best fit using a non-linear regression (p < 0.001), indicating an attenuated increase in serum leptin levels with high body mass index. No subgroup with low serum leptin levels could be identified. Weight reduction induced a rapid decrease in serum leptin levels within the first 3 weeks to levels significantly lower than in body mass index-matched controls under normal diet (p < 0.001). This pattern was consistent after 6 and 12 weeks. Serum leptin levels increased again after the end of the diet but remained significantly lower than in the controls despite unrestricted calorie intake over 7 weeks. The rapid and persistent decrease in serum leptin to lower levels than expected from matched controls may explain the pertinent difficulties of obese subjects to cope with weight reduction.
The influence of proteins on silver staining of nucleic acids following polyacrylamide gel electrophoresis.
The influence, on silver staining, of proteins and restriction enzymes in polymerase chain reaction (PCR) products was studied in 12-20% polyacrylamide gels. For small DNA fragments (74, 41 and 33 bp) best results were achieved using 20% polyacrylamide gels. In 12% gels, restriction enzymes and also proteins used for PCR (bovine serum albumin, Taq-DNA polymerase) interfere with silver staining of nucleic acids.
Loss of chromosome B2-material in three cases of feline mammary tumours.
Tumour cells in three cases of mammary gland neoplasms in cats were analysed cytogenetically. There was a loss of chromosome B2-material in all the cases, and a loss of chromosome E3-material in two of them.
[Present state of preclinical research on the efficacy and safety of para immunity inducers from poxviruses. A study of the literature].
The investigations on the "systemic level" after parenteral application of pox-inducers to man and animal have proved the preparations to be harmless and surprisingly effective with regard to certain indications. The clinical data correlate to laboratory parameters to serve as proof for the efficacy. The challenge models (VSV, Aujeszky) verify a dosis-efficacy relationship. The evaluation of the efficacy of the pox-inducers in isolated blood- and liver-cells respectively cell cultures (cellular "in vitro" level) provide a unified picture: increase of the phagocytosis, of the NK-cells and the thymidinkinase activity in liver cells. The investigations on the "cytokine release" illustrate that pox-inducers promote the release respectively the production of diverse cytokines important for the regulation of the immune system. This has been proved for interferon alpha and gamma, the interleukin 1, 2 and 12 as well as for CSF and TNF. To conclude, a regulative effect is ascribed to the poxvirus inducers in the network of paraspecific defence in regard to stimulating as well as inhibiting effects. The endogenous medication by way of pox-inducers (paramunization) is diametrically opposed to the exogenous application of cytokines.
Cytogenetic analyses of four solid tumours in dogs.
Four solid tumours (one haemangiopericytoma, one haemangioendothelioma, one spindle-cell sarcoma and one mammary carcinoma) in dogs were analysed cytogenetically. In the haemangiopericytoma, an additional small chromosomal segment was present. Very complex changes including centric fusions and symmetric meta-centrics 1, 6, 10 and 12 were conspicuous in the highly unbalanced karyotype of the haemangioendothelioma. Complex changes, particularly many centric fusions and a tandem translocation 4/14, were features of the spindle-cell sarcoma. One centric fusion and a symmetric metacentric 13 were present in the mammary carcinoma.
Trisomy D1, marker F1: new cytogenetic findings in two cases of feline fibrosarcoma.
An 11-year-old female cat and a 12-year-old male cat developed fibrosarcomas. Trisomy D1 was observed in a high percentage (20%) of the tumour cells of the female patient while a large marker chromosome F1 was present in 25% of the tumour cells of the male patient.
Simultaneous genotyping of sex and kappa-casein of bovine in vitro fertilized embryos by the PCR technique.
Sex and the kappa-casein genotype of in vitro produced cattle demiembryos was identified by simultaneous PCR-genotyping using polymorphic sites in ZFY/ZFX and kappa-casein genes. We obtained PCR products of 530 bp (kappa-casein) and of 445/447 bp (sex). Sex and the two kappa-casein alleles could be identified after digestion of the PCR products with Pstl and simultaneous separation of the restriction fragments on one step, allowing a rapid and efficient analyses of embryos.
Trisomy 1 in a canine mammary tubular adenocarcinoma, complex type.
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