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Biomedical subjects

B Mayr

Publications and source records attributed to B Mayr.

At least 109 records · Page 6Linked to original sources
PubMed1988

[The control of kennel cough].

Kennel cough is an infectious factorial disease with a multicausal genesis. The conventional methods (hygiene, management, chemotherapy, symptomatic therapy) are often insufficient in control of the disease. New methods were developed in collaboration with "problem kennels" (animal homes, dealer kennels etc.), which reduce the morbidity significantly. A so-called "synergistic combined vaccine" ("Candiflu", Behringwerke Marburg), which contains the basic viruses (reovirus, human influenza-A-virus, parainfluenza-2-virus), is recommended for prophylaxis. In problem kennels with a permanent changing of dogs the vaccination has to be supported by paramunization. Therapeutical success depends on the combination of conventional methods and the stimulation of the paraspecific immune system (paramunization). This new concept has been very successful in West Germany during the last years.

Animals↗
PubMed1988

[Visualization of the normal bronchial system by computed tomography].

Imaging of the normal bronchial system by CT was examined in 75 patients while employing different imaging parameters. The main and lobar bronchi could be demonstrated almost without exception in the standard examination of the thorax. Segmental bronchi were delineated in an average of 81% of the cases (512 image matrix) or 74% (256 image matrix), respectively. The lowest identification rate was seen in the segmental bronchi of the middle lobe and lingula being 38% (512 image matrix) and 18% (256 image matrix), respectively. Increase of the magnification factor did not result in any significant improvement of imaging. An increase in the identification rate of the segmental bronchi of the middle lobe and lingula was achieved only after reducing the slice thickness from 8 mm to 4 mm, the yield being now 87% (512 image matrix) and 82% (256 image matrix), respectively, whereas the remaining segmental bronchi could be made to show up almost without exception. The standard parameters are sufficient for routine examination of the bronchial system. If imaging is diagnostically not satisfactory, reducing the slice thickness yields improved imaging, especially of small bronchi.

Adult↗
PubMed1988

Mithun cross siri hybrids: cyto- and immunogenetic examinations and characterisation of abnormal spermatogenesis.

Cytogenetic studies of the mithun (Bos frontalis), the siri (Bos indicus) and their hybrids, as well as histological examinations of testes and epididymis of siri and hybrids were undertaken to throw further light on male hybrid infertility and interspecies incompatibility, in order to facilitate the possible development of a stable interspecies crossbreed which would be similar to the highly profitable jatsum, the female mithun cross siri hybrid. In both species there are distinct centromeric heteromorphisms which should provide a rich source of genetic markers for tracing chromosomes in controlled hybrid programmes. The nucleolar organisers in the F1 hybrids were derived from both parents, in contrast to other interspecies hybrids where the nucleolar organisers of one species tend to be suppressed by the other. This indicates a relatively close relationship between mithun and siri and supports the prospect of success for developing a stable crossbreed. Transferrins which may also be a useful source of genetic markers were identified and differences between siris and mithuns noted, especially in the D-bands. No A-bands were found in the siris and no E-bands in the mithuns. Whether this is a breed or species characteristic will have to be confirmed by examination of more animals. The findings on blood groups and haemoglobins, including differences between the two species, were similar to results obtained previously. In meiosis the sex vesicles were intact which indicates that infertility and incompatibility factors should be located in autosomes. In cytogenetic and histological examinations the testes of the siris were comparable to those of European cattle, while in all hybrids spermatogenetic activity was deficient although there were great differences between and within generations. While the exact mechanism of this diversity is not known at this stage, it should make it possible to select for increased male hybrid fertility which would be a prerequisite for developing a stable interspecies crossbreed. This selection would be facilitated by correlating infertility and incompatibility with genetic profiles and markers. A mithun cross siri crossbreed would also serve as a model for other interspecies breeding.

Animals↗
PubMed1987

Nucleolus-organizer regions and heterochromatin in three species of bovidae.

Ag-NOR staining and a counterstain-enhanced fluorescence technique (chromomycin A3/distamycin A/DAPI staining = CDD-method) have been applied to ibex (Capra ibex L.), chamois (Rupicapra rupicapra L.) and bison (Bison bison L.) chromosomes. Chromomycin A3 visualization led to a well defined R-banding pattern along the chromosome arms and to a clear demonstration of centric heterochromatic bands of variable size. The nucleolus organizer regions (NORs) were found in the telomeric regions of the chromosomes 2, 3, 4, 5 and 28 of the ibex, of the chromosomes 1/3 (short arm), 2, 4, 5 and 28 of the chamois and of the chromosomes 2, 3, 4, 11 and 28 of the bison.

Animals↗
PubMed1987

[Magnetic resonance imaging in craniopharyngiomas. The differential diagnosis of cystic intra- and suprasellar space-occupying lesions].

Seven patients with confirmed craniopharyngiomas were examined via magnetic resonance imaging. The various tumour components (whether solid, cystic or calcified) were evaluated separately. Three types of cysts were observed that can be distinguished by their signal intensity in various pulse sequences. This could be explained largely by an analysis of the T1 and T2 image contrast. The reason for the various types of cysts is determined by their cholesterol content. MR imaging is not as useful as CT for demonstrating the solid and calcified portions of the tumour and this reduces its value in diagnosing the type of tumour. Against that, it is superior with regard to separating the tumour from its neighbouring structures. The differential diagnosis, which must be considered in using MR, is summarised in a table at the end of the paper.

Craniopharyngioma↗
PubMed1987

Offspring of a trisomic cow.

A cow, trisomic for chromosome 22, became pregnant and gave birth to a karyotypically normal and healthy calf. Thus, a second example of reproductive capability in autosomal trisomies in mammals, in addition to trisomy 21 in man, is provided.

Animals↗
PubMed1987

An extended chicken karyotype, including the NOR chromosome.

Chicken chromosomes were identified up to No. 18 by a sequential counterstain-enhanced fluorescence technique. A heterochromatin characterization of macro- and microchromosomes was performed; in general, the microchromosomes were GC-rich, but with a high degree of variation. The NORs are localized on chromosome No. 17.

Animals↗
PubMed1986

Species-specific non-expression of ribosomal RNA genes in a mammalian hybrid, the mule.

The expression of nucleolus organizer activity in diploid cells was investigated in a model system for mammalian hybrids, the horse-ass cross (mule), by means of sequential Ag-NOR and chromomycin A3/distamycin A-DAPI (CDD) staining in lectin-stimulated peripheral blood lymphocytes (PBL). As a rule we found species-specific non-expression of the horse-derived NOR chromosomes in the mule, whereas the ass-derived NOR chromosomes were active. The results of PBL interphase studies were compatible with the data gained from mitotic metaphase analyses.

Animals↗
PubMed1986

Neurosurgical experience with magnetic resonance imaging in sellar lesions.

41 patients with various sellar and parasellar lesions (pituitary adenomas, meningiomas, optic gliomas, craniopharyngeomas and granulomas), who underwent surgery consecutively, were studied by MRI investigations. In 10 patients post-operative MRI controls were performed. The information obtained by the MRI were compared with the other radiological investigations (especially coronar and axial high resolution CT), and the intra-operative findings. The advantages of MRI in the diagnosis of sellar lesion are demonstrated by exemplary cases.

Adolescent↗
PubMed1986

[Potentialities and limitations of sonographic diagnosis of the chest in childhood].

The advantages and limitations of the sonographic examination of the chest in 16 children are described. Partial opacification of the chest has been found in nine, a total "white" hemithorax in 7 children. Sonographic guided taps of the chest were performed in 3 children. Necessity, extent and yield of additional radiological examinations, especially computed tomography of the thorax, are discussed in detail.

Child↗
PubMed1986

Heterochromatin composition and nucleolus organizer activity in four canid species.

Sequential staining with a counterstain-contrasted fluorescent banding technique (chromomycin A3-distamycin A-DAPI) revealed the occurrence of distamycin A-4,6-diamidino-2-phenylindole (DA-DAPI) staining heterochromatin in the centromeric regions of chromosomes 33, 36, 37, and 38 in the wolf (Canis lupus pallipes) and of chromosomes 13, 16, and 23 in the blue fox (Alopex lagopus). The red fox (Vulpes vulpes) lacked such regions. Staining with DAPI--actinomycin D produced a QFH-type banding pattern with clearcut differences in the staining behaviour of DA-DAPI positive regions between these three canid species. Staining with the fluorochrome D 287/170 did not preferentially highlight any of the DA-DAPI positive regions in any of them. Counterstain-enhanced chromomycin A3 R-banding and studies of nucleolus organizer region location and activity confirmed a close relationship between the karyotype of the wolf and the domestic dog. Few heterochromatic marker bands were encountered in these two species, but heterochromatin polymorphism was evident in the blue fox.

Animals↗
PubMed1986

Genetic characterisation of the mithun (Bos frontalis) and studies of spermatogenesis, blood groups and haemoglobins of its hybrids with Bos indicus.

The mithun (Bos frontalis) and its hybrids with Bos indicus were studied to provide further cytogenetic information which might throw light on the mechanisms of the male hybrid infertility and facilitate the establishment of a stable crossbreed. It was shown that compared with conventional cattle the mithun has a homozygous, species specific 2/27 centric fusion which reduced the diploid chromosome number from 60 to 58. This provided further proof that Robertson translocation-type rearrangements have been the major source of interspecies karyotype differences in the evolution of the Bovidae. In the mithun there was also significant polymorphism between centromeres of non-homologous chromosomes and there was heteromorphism between several homologous chromosomes which could possibly serve as useful genetic markers for breeding programmes. In F1 hybrids spermatogenesis progressed to a relatively advanced stage, without going so far as to produce spermatozoa. In back crosses to B indicus spermatogenesis progressed further so that spermatozoa could be seen, though not as numerous as in normal bulls. In most hybrids there were haemoglobin bands which corresponded either to Hb A or Hb B of cattle but were much wider. It was shown that these were a combination of Hb Mi derived from the mithun and Hb A or Hb B derived from B indicus. In a few hybrids there were only Hb Mi. In these cases Hb Mi had been present in both parents and proved that the dam was not a pure siri. The possible mechanism of hybrid male infertility is discussed including faults in the epistatic gene effect between chromosomes and changes in the degree of association of centromeric regions in interspecies hybrids. It is suggested that additional cytogenetic examination of blood lymphocytes and especially of testicles would help the understanding of the fertility barriers of hybrid males and would make a breeding programme for a stable crossbreed possible.

Animals↗