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Biomedical subjects

B Kovács

Publications and source records attributed to B Kovács.

At least 19 recordsLinked to original sources
PubMed2001

[Hemorheologic factors in hypertensive and diabetic retinopathy].

Hemorheological factors play an important role in the pathogenesis of different cardiovascular diseases. In the present study the fundus picture and hemorheological parameters (plasma and whole blood viscosity *WBV* by capillary viscosimetry; fibrinogen level; red blood cell aggregation by Myrenne and LORCA aggregometers) of 33 hypertensive patients (23 females, 10 males; mean age: 55 years) and 30 diabetic patients (14 females, 16 males; mean age: 57 years) and healthy controls were examined. The fundus pictures showed different forms of retinopathy in both groups. All the measured hemorheological parameters of the examined patients were in the pathological range and were significantly higher than in healthy controls. In the group of hypertensive patients hematocrit (p < 0.05), plasma fibrinogen (p < 0.01), plasma viscosity (p < 0.01) and whole blood viscosity (p < 0.01) showed a significant increase. The hemorrheological factors showed a parallel deterioration with the severity of hypertension (measured BP values) and of fundus picture, namely their values were significantly (p < 0.01) higher in patients with stage III fundus picture (WBV at 90 1/s: 6.02 mPas), than stage I hypertension (WBV at 90 1/s: 4.51 mPas). In the diabetic group hematocrit (p < 0.01), plasma fibrinogen (p < 0.001), plasma viscosity (p < 0.01), "WBV" (p < 0.001), red blood cell aggregation (p < 0.05) showed a significant increase comparing to healthy controls. These results show that there is a correlation between hemorrheological parameters and fundus picture in hypertensive and diabetic patients, and this suggests that hemorrheological factors may play a role in the development of hypertensive and diabetic retinopathy.

Adult↗
PubMed2001

Cognitive subprocesses of mental rotation: why is a good rotator better than a poor one?

The Vanderberg-Kuse Mental Rotation Test is a standard test of mental rotation ability. Recent experiments have demonstrated that mental rotation is a complex cognitive process wherein different subprocesses (focused attention, visual scanning, perceptual decision, visual memory) play important roles in performance. We classified the population as good and poor rotators by performance of mental rotation (ns = 47: 22 men and 25 women, respectively; mean age: 20.7 yr.). To examine differences cognitive subprocesses of mental rotation of these two groups were compared. There were significant differences between poor and good rotators in performance on Raven's test and the Pieron Focused Attention test scores. The good rotators scored better because their perceptual decision-analytical intelligence (Raven) and focused attention scores were higher.

Adult↗
PubMed2000

Male-specific DNA markers from African catfish (Clarias gariepinus).

We searched for sex-specific DNA sequences in the male and female genomes of African catfish, Clarias gariepinus (Burchell, 1822) by comparative random amplified polymorphic DNA (RAPD) assays performed on pooled DNA samples. Two sex-linked RAPD markers were identified from the male DNA pool and confirmed on individual samples, showing good agreement with phenotypic sex. Both markers were isolated, cloned and characterized. The first marker (CgaY1) was nearly 2.6 kb long, while the length of second one (CgaY2) was 458 bp. Southern blot analysis with a CgaY1 probe showed strong hybridizing fragments only in males and not in females under stringent conditions, indicating the presence of multiple copies of CgaY1 in the male genome. When tested by zoo blot on the genomes of two closely related species from the Clariidae family, CgaY1 hybridized to the DNA of Heterobranchus longifilis and generated a faint male-specific band at low stringency. CgaY2 produced similar hybridization pattern in both sexes of C. gariepinus, C. macrocephalus and H. longifilis. Specific primers were designed to the sequences and the markers were amplified in multiplex PCR reactions together with a control band common to all individuals. This allowed for rapid, molecular sexing of the species on the basis of a simple three band (male) versus one band (female) pattern. According to our knowledge these are the first sex-specific DNA markers isolated from a siluroid fish species.

Animals↗
PubMed1999

Sex differences on the hand mental rotation task for 9-yr.-old children and young adults.

The Hand Mental Rotation task is assumed to activate an egocentric spatial reference frame to realize mental rotation. This study presents significant sex differences in hand mental rotation performances between men and women (n = 23 and 25, respectively; age: 20.7 yr.). Differences in hand mental rotation in school girls and boys (ns = 48 and 41, respectively; age: 9 yr.) were not significant. Our results suggest that the change in sex differences in egocentric mental rotation may occur with developmental change. This requires further testing with a larger sample so testing can occur at several ages between 9 and 20.7 years.

Adult↗
PubMed1994

Use of Brulamycin (tobramycin) eye drops in the preoperative and postoperative treatment of ophthalmotomies.

The conjunctival bacterium flora was examined during the preoperative and postoperative treatment of 200 patients who underwent intraocular surgery. Brulamycin eye drops (15 mg tobramycinum in 5 ml solution) were given to 100 patients and Oculogutta neomycin (50 mg neomycinum sulfuricum in 100 ml solution) to 100 patients. The effectivity, objective and subjective side-effects of the two drugs, and resistance to the drugs were examined. On the basis of comparative data and the observations of the authors, Brulamycin eye drops are recommended for the premedication of intraocular surgery.

Aged↗
PubMed1990

[Deformation phenomena occurring during compression. III. Changes of maximal compression strength in quasi-static condition].

Four materials of different properties in respect of compressibility, lactose, sodium chloride, microcrystalline cellulose (Avicel PH 101) and so-called simple granulate were investigated. In function of time and that of actual pressing force decrease of axial force on upper punch were measured in quasi-state. Evaluating relations it was established that both pressing time and pressing force had influence on deformation structural changes occurring inside compressed form. Furthermore, summing up of results showed that useful conclusions could be drawn from diagrams--which represented decrease of force--to compressibility properties of materials too.

Cellulose↗
PubMed1990

[Deformation phenomena occurring during compression. II].

Compressed forms were prepared from sodium chloride of given granule size with mildly concave punches applying 4, 12 and 20 kN pressing force. Pressing was regulated in order to get maximum pressing force effect for 0.1 s, 30 s and 60 s. Textures of side of compressed forms as well as edge and middle of surface of compressed forms were investigated by scanning electron microscope. Photos made with different enlargement have proved that secondary structural changes have begun (colour changes, new crystals have come to being etc.) on side stronger but also well observable on surface of compressed forms which in function of pressing force and that of time of pressing force effect have increased and grown considerably.

Microscopy, Electron, Scanning↗
PubMed1990

[Deformation phenomena occurring during compression. I].

Tablets were prepared from sodium chloride of given granule size with 4, 12 and 20 kN pressing force. Pressing was regulated in order to get maximum pressing force effect for 0.1 s, 30 s and 60 s. With the intention of studying deformation changes texture investigation of breaking surface of tablets was carried out by scanning electron microscope. Investigation results documented with photos of different enlargement showed that both pressing force and pressing force effect influenced deformation changes and also structure of tablets. Increase of time of pressing force effect resulted in perfection of deformation changes.

Microscopy, Electron, Scanning↗
PubMed1989

[Preparation and in vitro study of suppositories containing No-Spa. II. Determination of release of the active principle by membrane diffusion methods].

The authors have made proposal of pharmaceutical technology of a well storable, excellent drug release No-Spa./suppository besides No-Spa./tablets and injection have been in circulation in this country. Without Estaram 299 of small hydroxyl value or combined with 10% ESTASAN oil it suits to therapeutical expectations in every respect. Physical parameters of suppositories and chemical stability of drotaverinium chloride have been excellent on the basis of one year storing. On the ground of in vitro investigations the suppository has been proposed to be introduced to human therapy as antispasmodic preparation.

Diffusion↗
PubMed1985

Alteration of the blood-retina barriers in cases of viral retinitis.

This paper presents three cases of serologically documented viral retinitis, and the great value of fluorescein angiography in outlining the structural abnormalities and the site of the lesions. Of our series in the case of influenza retinitis, the fluoroangiographic findings showed dye leakage from retinal vessels in the posterior pole. The dye leakage did not appear completely in the sites of macular edema. This edema was similar to the clinical appearance of cotton-wool spots and was arranged in a star-like pattern. One of the cases of cytomegalovirus retinitis (Case 3), a previously healthy adult with dysfunction of the cellular immune system, seems to be a further example of an inflammation in the inner retina presenting cotton-wool spots at the early stage. Case 2, a previously healthy adult, fulfilled the criteria for Vogt-Koyanagi-Harada syndrome. The patient had serologically documented cytomegalovirus infection with dysfunction of the cellular immune system. The fluorescein angiographic examination showed alteration both in the inner and outer blood-retina barriers as it is characteristic in cases of Harada syndrome. The cytomegalovirus infection might be assumed to play a role in the clinical picture as well as in the etiology of this disease.

Adult↗