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Biomedical subjects

A Stankiewicz

Publications and source records attributed to A Stankiewicz.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Glutathione S-transferase as a metabolic biomarker for predisposition to lung neoplasms induced by chemical carcinogens].

In the case of lung cancer induced by chemical carcinogens, cellular processes of metabolic activation and deactivation of these substances play a particular role. The involvement of glutathione--S-transferase in the process of deactivation of active metabolites draws special attention. Cellular activity of these enzymes is a significant factor which can define individual susceptibility to carcinogenic effect of occupational and environmental carcinogens. Glutathione--S-transferase catalyses the reaction of binding glutathione with a great number of pharmacologically active substances, including also those with genotoxic properties. These reactions protect cells against toxic and genotoxic effect of exo- and endogenous substances. They prevent among others, from producing adducts by genotoxic substances with macromolecules. Some of glutathione--S-transferases (the so-called ligands) act as proteins which bind and transport organic ligands in cells (bilirubin, steroid metabolites, bile acids). To date studies have not confirmed uni-vocally that low activity of glutathione--S-transferases be one of the reasons for an increased incidence of lung cancer. Observations of persons with phenotype of a low activity of glutathione--S-transferase (GSTM1-0) have indicated that the incidence of lung cancer is significantly higher among them than in persons with phenotype of normal activity of this enzyme. These observations, however, have not been confirmed by an analysis of relationship between the incidence of lung cancer and the genotype of low and normal activity of glutathione--S-transferase.

Biomarkers, Tumor↗
PubMed1995

Cathepsin D and an alkaline protease activities in subretinal fluid.

It was found that subretinal fluid contains at least two different proteolytic enzymes which digest various protein substrates. The main of them was identified as cathepsin D. This protease is very active towards the denatured haemoglobin. The highest activity is apparent at pH 3-4 and it is completely inhibited by the action of pepstatin. The cathepsin activity increases with the duration of retinal detachment. The other proteolytic enzyme acts at slightly alkaline pH. Its activity is lower and does not change with the duration of the disease.

Body Fluids↗
PubMed1994

[Behavior of selected cytokines in subretinal fluid].

The aim of the investigations was to search the subretinal fluid for the inflammatory interleukins which influence T and B lymphocytes. The levels of IL-1, IL-2, IL-4 and IL-6 were determined. Only IL-6 was found in a significantly high level, especially in cases with retinal detachment lasting 5-8 weeks. The level of other interleukins examined was not significant.

Aged↗
PubMed1993

A Euglena gracilis zinc endonuclease.

A 26-kDa endonuclease has been purified to homogeneity from zinc-sufficient Euglena gracilis. The protein binds to single-stranded DNA with a higher affinity than to double-stranded DNA, but it exhibits nucleolytic activity toward both. Thus, it converts supercoiled plasmid pBR322 DNA into the linear form, a property characteristic of endonucleases, and it continues to act on the linearized DNA until it is completely degraded. It also hydrolyzes heat-denatured, single-stranded calf thymus DNA. Moreover, at amounts below 1 microgram, it enhances RNA synthesis by RNA polymerase II, a characteristic observed with other DNases. Its addition to an in vitro transcription assay increases RNA synthesis up to 3-fold. The nuclease requires two metal components to carry out its enzymatic activities. It hydrolyzes DNA only in the presence of millimolar amounts of magnesium or micromolar quantities of other activating metal ions, such as manganese, zinc, or cobalt. However, even when optimal concentrations of Mg2+ are present, micromolar amounts of the metal-chelating agents OP and HQSA completely inhibit pBR322 digestion. Transcription enhancement is also inhibited completely by both chelators at concentrations that do not affect the intrinsic polymerase II activity. By atomic absorption spectrometry, the enzyme contains 1 g-atom of Zn/mol, which is the likely target of chelator action. The nuclease protein can also be isolated from zinc-deficient E. gracilis, but remarkably it then contains 1 mol of Cu/g-atom and no zinc.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1993

[500 operations of retinal detachment. Early and long-term evaluation].

The early and long-term postoperative results of 453 patients (510 eyes) with retinal detachment, treated with several buckling procedures, have been analysed. The follow-up, ranging from 2 to 9 years, revealed that the better anatomical and functional results were observed in the group of 325 eyes, in which the complete subretinal fluid drainage had been performed during the surgery, compared with 185 non-drained eyes.

Child↗
PubMed1991

Glucose-6-phosphate dehydrogenase activity in erythrocytes of patients with malignant neoplasms.

G6PD activity in erythrocytes was examined in 129 people with malignant neoplasms (83 males, 46 females). In all these subjects G6PD activity in erythrocytes was markedly higher than in the controls. Tumour surgery resulted in decreased activity of that enzyme in the erythrocytes. The controls were 53 healthy persons (38 males, 15 females) not exposed occupationally to carcinogens.

Adult↗
PubMed1991

[Function of the visual system after orbital surgery. Late observations].

Forty six persons with an orbital tumor were operated in the period of 1980-1988. A control examination performed in 39 persons did not show in 38 any characteristics of recurrence of the tumor; the motility of the eye ball was normal. In 29 persons the visual acuity of the eye at the side of the operated tumor was over 5/6.

Adolescent↗
PubMed1990

[Glucose-6-phosphate dehydrogenase as a marker of genetic predisposition to neoplasms].

In the light of reports in the literature the data are presented on the importance of glucose-6-phosphate dehydrogenase in cell metabolism. The effect of decreased enzyme activity or its complete absence on the functions of the cell, and the clinical conditions associated with deficient enzyme activity are described. The influence is discussed of the genetic determination of the enzyme on the occurrence of phenotypic effects, and the use of the mosaicism phenomenon in the study on the pathogenesis of certain disturbances. Several reports from the literature are quoted concerning the study of the reverse relationship between a deficiency of the activity of the enzyme and the incidence of carcinoma. The necessity is stressed of including electrophoretic techniques into the studies.

Adult↗
PubMed1990

[Conservative treatment of post-traumatic lesion of the optic nerve].

Twenty one patients aged 18-77 years with a lesion of the optic nerve caused by contusion of the head were treated conservatively in the period 1980-87. An improvement--often a substantial one--of the visual acuity was attained in 52.3 p.c. of patients; in 17 patients the vision did not deteriorate in the period of control examinations.

Adolescent↗
PubMed1990

[Evaluation of the effectiveness of Quinax in the prevention of the development of senile cataract].

The authors evaluated the efficacy of Quinax in 4 groups of patients with cataract. An observation of--on the average--5 years duration showed that systematic application of the drug prevents the development of the early senile cataract and distinctly slows down the progress of the disease in the group of patients without the risk factors. Non systematic application of the compound also slows down the progress of the condition in the group of early cataract. The drug was ineffective in patients with an advanced diabetic cataract.

Acridines↗
PubMed1989

[Intrascleral sclerectomy with implantation of a polyethylene tube in hemorrhagic glaucoma. Preliminary report].

Four patients with haemorrhagic glaucoma and 1 with secondary glaucoma were operated by the method of intrascleral sclerectomy with implantation of a polyethylene tube. After surgery all the patients showed a normalization of the intraocular pressure but in 2 persons it was transitory and after some months the IOP raised above 30 mm Hg. These patients however did not complain of pain and this was already a sort-of success in such severe cases.

Adult↗