Biomedical subjects

I Miklós

Publications and source records attributed to I Miklós.

12 recordsLinked to original sources

PubMed2000

Leiomyosarcomas of great vessels.

Sarcomas of the great vessels are rare. Altogether 400 such cases have been described in the aorta, the pulmonary artery, and inferior vena cava. The clinical symptoms are generally related to embolic phenomena, aneurysm formation, and widespread metastases, especially to bones. With improved diagnostic modalities more cases are diagnosed and treated surgically. Resection of the tumor may prolong the patient s life. In this paper authors present two cases of such rare sarcomas. In our first case a tumor has developed in the thoracic aorta with symptoms of imminent aortic dissection. The tumorous nature of the lesion was revealed only histologically, since neither the operation, nor macroscopic picture gave any clue to its tumorous nature. The second case was a male patient with a huge retroperitoneal tumor arising from the inferior vena cava, which was clinically suspected to be a carcinomaarising in the adrenal gland.

Adrenal Gland Neoplasms↗

PubMed2000

The Schizosaccharomyces pombe sep15+ gene encodes a protein homologous to the Med8 subunit of the Saccharomyces cerevisiae transcriptional mediator complex.

We previously described the isolation of mutants defective in cell separation and the identification of 16 sep genes with complex functions. Here we report on the cloning and analysis of sep15+. The deduced amino acid sequence of the Sep15 protein shows significant homology to Med8, a component of the Saccharomyces cerevisiae transcription mediator complex. The mutation sep15-598 confers hyphal morphology and causes temperature-sensitive lethality. Disruption of sep15+ is lethal, indicating that Sep15 exerts an essential function and its role in cell separation is indirect.

Amino Acid Sequence↗

PubMed1999

Epigenetic inheritance, genetic assimilation and speciation.

Epigenetic inheritance systems enable the environmentally induced phenotypes to be transmitted between generations. Jablonka and Lamb (1991, 1995) proposed that these systems have a substantial role during speciation. They argued that divergence of isolated populations may be first triggered by the accumulation of (heritable) phenotypic differences that are later followed and strengthened by genetic changes. The plausibility of this idea is examined in this paper. At first, we discuss the "exploratory" behaviour of an epigenetic inheritance system on a one peak adaptive landscape. If a quantitative trait is far from the optimum, then it is advantageous to induce heritable phenotypic variation. Conversely, if the genotypes get closer to the peak, it is more favorable to canalize the phenotypic expression of the character. This process would lead to genetic assimilation. Next we show that the divergence of heritable epigenetic marks acts to reduce or to eliminate the genetic barrier between two adaptive peaks. Therefore, an epigenetic inheritance system can increase the probability of transition from one adaptive state to another. Peak shift might be initiated by (i) slight changes in the inducing environment or by (ii) genetic drift of the genes controlling epigenetic variability. Remarkably, drift-induced transition is facilitated even if phenotypic variation is not heritable. A corollary of our thesis is that evolution can proceed through suboptimal phenotypic states, without passing through a deep adaptive valley of the genotype. We also consider the consequences of this finding on the dynamics and mode of reproductive isolation.

Animals↗

PubMed1999

Genetics, physiology and cytology of yeast-mycelial dimorphism in fission yeasts.

The order Schizosaccharomycetales contains a dimorphic and two yeast species. Sch. japonicus can form both yeast cells and mycelium, depending on the substrate and the culturing conditions. Sch. pombe is a strictly unicellular organism, but it can be forced to form mycelial cell chains by inactivating members of the sep gene family. The mutations in most of the sep genes confer pleitropic phenotypes indicating functional involvement in MAP-kinase-mediated signalling pathways. Two of them were found to encode transcription factor homologues of other eukaryotes.

Cell Polarity↗

PubMed1995

Heterogeneous distribution of ecto-Ca-ATPases in primary cultures of human adenohypophyseal cells.

The aim of this study was to investigate the localization of ecto-Ca-adenosine-triphosphatase (ecto-Ca-ATPase) in different parenchymal cells of the human pituitary in tissue culture. The distribution of ecto-ATPases on the surface membrane of a particular parenchymal cell varied with the type of cells in contact with this parenchymal cell; the membrane portions immediately exposed to the medium showed low if any ecto-ATPase activity. These results suggest that ecto-Ca-ATPases of the parenchymal cells may be involved in cell adhesion processes and may be of crucial importance in the organization (in vivo) and reorganization (in vitro) of human adenohypophyseal tissue.

Adenosine Triphosphatases↗

PubMed1994

Osmotolerant yeasts isolated from Tokaj wines.

Yeasts growing in "Tokaj Aszu" wine and in "Aszu essence" were isolated and characterised. They proved to be physiological races of Saccharomyces cerevisiae and showed high osmotolerance, which was an inherited feature rather than the result of adaptation. No correlations were found between the osmotolerance and the ethanol tolerance or the cell size and morphology. Yeasts in "Aszu essence" are usually undesirable contaminants that impair the quality of the essence. The isolate characterized in this work exhibited physiological parameters very similar to those of the "Tokaj Aszu" strain, which make it a potent competitor of other yeasts in Aszu fermentation. However, the high termo sensitivity of its cells offers a possibility to eliminate them selectively.

Ethanol↗

PubMed1991

[Endoscopic intubation and intracavitary irradiation in the palliative treatment of inoperable esophageal tumors].

The authors have applied at first in Hungary the intracavital after loading radiotherapy in patients suffering from esophageal tumor. A new method was elaborated for the combined use of endoscopic tube insertion and intracavital irradiation. Out of the 155 patients admitted on the 1st Surgical Department of Semmelweis University, Budapest, 63 had been treated only by tube insertion, 44 were intubated and irradiated, whereas 48 patients had intracavital radiotherapy without intubation. Radiotherapy was performed at the Radiological Unit of Semmelweis University. The irradiation dose ranged from 26,9 to 32,2 Gray in average. The mean survival of group I. was 4,0 months, that of group II. 6,3 months, and in group III. 7,0 months respectively. The expected survival is proportional to the radiation dose. No correlation exists between tumor localisation and survival. Respiratory fistula, the most common complication, occurred in different groups as follows: 3,4%, 6,2%, and 9,0%; but could have been treated by tube insertion, or adequate positioning of the tube. The combined use of intubation and intracavital after loading radiotherapy has been proven to be suitable for palliative treatment of inoperable esophageal tumors.

Aged↗

PubMed1982