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Biomedical subjects

J Vrána

Publications and source records attributed to J Vrána.

At least 19 recordsLinked to original sources

[Using of scanning electron microscopy for detection of gunshot residue].

Scanning electron microscope improves the possibility of investigation of surroundings near of gunshot wounds in forensic medicine, it is the next subsequent method for differentiating of area of entrance and exit wound, supplemental method for determination of firing distance, permit of detection (GSR) on the hand of shooter and ensured describing of samples and their stored. Detection of GSR provides many information about composition of bullet and primer. Authors are demonstrating the possibility of detection of GSR on experimental shooting to the krupon (pigs' skin) in different situation (such as in a room and in outside area) and using of different weapon (hand gun CZ No.75 and machine gun No.58).

Animals↗

Analysis and sorting of rye (Secale cereale L.) chromosomes using flow cytometry.

Procedures for chromosome analysis and sorting using flow cytometry (flow cytogenetics) were developed for rye (Secale cereale L.). Suspensions of intact chromosomes were prepared by mechanical homogenization of synchronized root tips after mild fixation with formaldehyde. Histograms of relative fluorescence intensity obtained after the analysis of DAPI-stained chromosomes (flow karyotypes) were characterized and the chromosome content of the DNA peaks was determined. Chromosome 1R could be discriminated on a flow karyotype of S. cereale 'Imperial'. The remaining rye chromosomes (2R-7R) could be discriminated and sorted from individual wheat-rye addition lines. The analysis of lines with reconstructed karyotypes demonstrated a possibility of sorting translocation chromosomes. Supernumerary B chromosomes could be sorted from an experimental rye population and from S. cereale 'Adams'. Flow-sorted chromosomes were identified by fluorescence in situ hybridization (FISH) with probes for various DNA repeats. Large numbers of chromosomes of a single type sorted onto microscopic slides facilitated detection of rarely occurring chromosome variants by FISH with specific probes. PCR with chromosome-specific primers confirmed the identity of sorted fractions and indicated suitability of sorted chromosomes for physical mapping. The possibility to sort large numbers of chromosomes opens a way for the construction of large-insert chromosome-specific DNA libraries in rye.

Cell Separation↗

Development of flow cytogenetics and physical genome mapping in chickpea (Cicer arietinum L.).

Procedures for flow cytometric analysis and sorting of mitotic chromosomes (flow cytogenetics) have been developed for chickpea (Cicer arietinum). Suspensions of intact chromosomes were prepared from root tips treated to achieve a high degree of metaphase synchrony. The optimal protocol consisted of a treatment of roots with 2 mmol/L hydroxyurea for 18 h, a 4.5-h recovery in hydroxyurea-free medium, 2 h incubation with 10 micromol/L oryzalin, and ice-water treatment overnight. This procedure resulted in an average metaphase index of 47%. Synchronized root tips were fixed in 2% formaldehyde for 20 min, and chromosome suspensions prepared by mechanical homogenization of fixed root tips. More than 4 x 10(5) morphologically intact chromosomes could be isolated from 15 root tips. Flow cytometric analysis of DAPI-stained chromosomes resulted in histograms of relative fluorescence intensity (flow karyotypes) containing eight peaks, representing individual chromosomes and/or groups of chromosomes with a similar relative DNA content. Five peaks could be assigned to individual chromosomes (A, B, C, G, H). The parity of sorted chromosome fractions was high, and chromosomes B and H could be sorted with 100% purity. PCR on flow-sorted chromosome fractions with primers for sequence-tagged microsatellite site (STMS) markers permitted assignment of the genetic linkage group LG8 to the smallest chickpea chromosome H. This study extends the number of legume species for which flow cytogenetics is available, and demonstrates the potential of flow cytogenetics for genome mapping in chickpea.

Cell Cycle↗

Localization of male-specifically expressed MROS genes of Silene latifolia by PCR on flow-sorted sex chromosomes and autosomes.

The dioecious white campion Silene latifolia (syn. Melandrium album) has heteromorphic sex chromosomes, XX in females and XY in males, that are larger than the autosomes and enable their separation by flow sorting. The group of MROS genes, the first male-specifically expressed genes in dioecious plants, was recently identified in S. latifolia. To localize the MROS genes, we used the flow-sorted X chromosomes and autosomes as a template for PCR with internal primers. Our results indicate that the MROS3 gene is located in at least two copies tandemly arranged on the X chromosome with additional copy(ies) on the autosome(s), while MROS1, MROS2, and MROS4 are exclusively autosomal. The specificity of PCR products was checked by digestion with a restriction enzyme or reamplification using nested primers. Homology search of databases has shown the presence of five MROS3 homologues in A. thaliana, four of them arranged in two tandems, each consisting of two copies. We conclude that MROS3 is a low-copy gene family, connected with the proper pollen development, which is present not only in dioecious but also in other dicot plant species.

Amino Acid Sequence↗

Localisation of DNA sequences on plant chromosomes using PRINS and C-PRINS.

Localisation of DNA sequences to plant chromosomes in situ has traditionally been accomplished using fluorescence in situ hybridisation (FISH). Although the method is suitable for most applications it is time-consuming and requires labelled probes. Recently, primed in situ labelling (PRINS) has been developed as an alternative to FISH. PRINS is based on annealing of unlabelled oligonucleotide primer(s) to chromosome DNA and its elongation by DNA polymerase in the presence of labelled nucleotide(s). The method was found useful to detect high-copy tandem repeats on plant chromosomes. Low copy repeats were detected after a more sensitive variant of PRINS called cycling PRINS (C-PRINS), which involves a sequence of thermal cycles analogous to polymerase chain reaction. This paper describes protocols of PRINS and C-PRINS, which have been optimised for chromosome spreads and for chromosomes purified using gradient centrifugation and/or flow sorting. The methods result in clear signals with negligible non-specific labelling. Further work is needed to improve the sensitivity to allow for reliable detection of single- copy DNA sequences.

DNA, Plant↗

Rapid identification and determination of purity of flow-sorted plant chromosomes using C-PRINS.

BACKGROUND: Flow-sorted plant chromosomes are being increasingly used in plant genome analysis and mapping. Consequently, there is a need for a rapid method for identification of sorted chromosomes and for determination of their purity. We report on optimization of procedures for primed in situ DNA labeling (PRINS) and cycling-PRINS (C-PRINS) for fluorescent labeling of repetitive DNA sequences on sorted plant chromosomes suitable for their identification. METHODS: Chromosomes of barley, wheat, and field bean were sorted onto microscope slides, dried, and subjected to PRINS or C-PRINS with primers for GAA microsatellites (barley and wheat) or FokI repeat (field bean). The following parameters were optimized to achieve the highest specificity and intensity of fluorescent labeling: ratio of labeled versus unlabeled nucleotides, nucleotide concentration, and the number and concentration of primers. RESULTS: Under optimal conditions, C-PRINS resulted in strong and specific labeling of GAA microsatellites on sorted barley and wheat chromosomes and FokI repeats on sorted field bean chromosomes. The labeling patterns were characteristic for each chromosome and permitted their unequivocal identification as well as determination of purity after sorting, which ranged from 96% to 99%. A standard polymerase chain reaction (PCR) with chromosome-specific primers was not sensitive enough to detect low-frequency contamination. CONCLUSIONS: The results indicate that a single C-PRINS assay with primers that give chromosome-specific labeling pattern is sufficient not only to determine chromosome content of peaks on flow karyotype but also to determine the purity of sorted chromosome fractions. The whole procedure can be performed in less than 3 h on the next day after sorting. Numerous applications are expected in the area of plant flow cytogenetics.

Chromosomes↗

Flow sorting of mitotic chromosomes in common wheat (Triticum aestivum L.).

The aim of this study was to develop an improved procedure for preparation of chromosome suspensions, and to evaluate the potential of flow cytometry for chromosome sorting in wheat. Suspensions of intact chromosomes were prepared by mechanical homogenization of synchronized root tips after mild fixation with formaldehyde. Histograms of relative fluorescence intensity (flow karyotypes) obtained after the analysis of DAPI-stained chromosomes were characterized and the chromosome content of all peaks on wheat flow karyotype was determined for the first time. Only chromosome 3B could be discriminated on flow karyotypes of wheat lines with standard karyotype. Remaining chromosomes formed three composite peaks and could be sorted only as groups. Chromosome 3B could be sorted at purity >95% as determined by microscopic evaluation of sorted fractions that were labeled using C-PRINS with primers for GAA microsatellites and for Afa repeats, respectively. Chromosome 5BL/7BL could be sorted in two wheat cultivars at similar purity, indicating a potential of various wheat stocks for sorting of other chromosome types. PCR with chromosome-specific primers confirmed the identity of sorted fractions and suitability of flow-sorted chromosomes for physical mapping and for construction of small-insert DNA libraries. Sorted chromosomes were also found suitable for the preparation of high-molecular-weight DNA. On the basis of these results, it seems realistic to propose construction of large-insert chromosome-specific DNA libraries in wheat. The availability of such libraries would greatly simplify the analysis of the complex wheat genome.

Cell Cycle↗

Testicle hemodynamics in patients after laparoscopic varicocelectomy evaluated using color Doppler sonography.

OBJECTIVES: Testicular blood supply and semen quality were compared in two groups of patients undergoing laparoscopic varicocelectomy: group I (n = 27) with spermatic artery ligation and group II (n = 48) with spermatic artery preservation. METHODS: Laparoscopic varicocelectomy was performed on 75 patients divided on the basis of whether ligation took place during surgery or not. The blood flow parameter (resistance index-RI) measured using color Doppler sonography was the index of vascular efficiency selected. RESULTS: Mean RI was 0.69 in group I and 0.65 in group II. The difference was not significant. Both groups showed improvements in sperm density and motility but there was no significant difference between groups for either parameter. CONCLUSION: Using color Doppler sonography confirms that ligation of the testicular artery during varicocelectomy does not lead to major changes in testicular blood supply or sperm quality.

Adolescent↗

[Laparoscopic surgery of varicoceles and its effect on testicular hemodynamics and spermiogenesis].

Between December 1993 and October 1996 the authors performed laparoscopic operations of varicocele in 75 patients incl. 53 for concurrent subfertility. In all patients before operation by Doppler sonography and coloured Doppler mapping venous reflux was detected. The volume of the testis was also assessed by sonography. In subfertile patients changes of the spermiogram were assessed. After operation the blood supply was evaluated (the resistive index), the volume of the testes, the duration of the operation and changes in the spermiogram. The authors did not detect a significant difference between the group of 27 patients where with the vein also the artery was ligatured and the group of 48 patients where only the vein was ligatured. The patients were not damaged by ligature of the artery.

Adolescent↗

Doppler ultrasonography in evaluation of renal hemodynamics in hydronephrosis in children.

Resistence index (RI) measurement by the Doppler sonography is a noninvasive diagnostic method which was introduced in the diagnosis of hydronephrosis in children in 1989. In 1991 Palmer modified this method by administering furosemide (Diuretic Doppler ultrasonography) in order to distinguish an obstructional and nonobstructional dilatation of the upper urinary tract. The method is based on the fact that an obstruction of the upper urinary tract results in increasing of the intrarenal arterial resistence and therefore in decreasing of vascular flow. RI value shows the importance of obstruction. The authors performed this method on 37 children aged 2 to 16, 12 children with a significant ureteropelvic obstruction, 15 children with a nonsignificant obstruction (hydronephrosis of grades I-II and persisting dilatation of the ureteropelvic system after pyeloplasty); the control group consisted of 10 children with normal sonography and scintigraphy findings in the kidneys. The results were compared to the results of dynamic scintigraphy -99m Tc DTPA with furosemide. Elevation of RI values in clinically significant hydronephrosis was proved. The authors see the utility of Doppler ultrasonography as being in the diagnosis of nonsignificant obstructions, in the screening of children with ureteropelvic system dilatation, and in follow-up examinations of children after pyeloplasty.

Adolescent↗

Importance of sonography with furosemide in continuing dilatation after pyeloplasty.

The continuance of collecting system dilatation after plastic repairing of the ureteropelvic junction in children progressed hydronefrosis may have two causes, the first one is a great progress of the process, that do not allow to repair the dilatation, the second one is to be a failure with the operation. Another treatment depends on differentiating there two causes. Authors used ultrasonography with furosemide test. By comparing sonogram before and after giving furosemide. They described whether the continuance of collecting system dilatation can be caused by a urodynamic obstruct. The result is that the ultrasonography with furosemide is a simple of orientation noninvasive method, which can be used several times without risks for the children. According to experience of the authors more precise is the method with oral furosemide application that the intravenous. It is a method of orientation which can be filled by dynamic scintigraphy in case of suspicion on bad evacuation with furosemide. Then if the obstruction is confirmed, we can indicate the excretory urography with furosemide.

Administration, Oral↗

[Self-care in the prevention of sudden cardiac death].

In acute myocardial infarction a third up to half of death registered within the first month occur in the first hour of the onset of attack most frequently because of ventricular fibrillation. Immediate self administration of drugs stabilizing electrically the heart may prevent it. On the basis of experiments in dogs and in rats flunitrazepam (Rohypnol tabl. 1 mg), tramadol (Tramal caps. 50 mg) and the beta blocker metipranolol (Trimepranol tabl. 10 mg) were selected for clinical trial on high risk patients. As the chosen combinations of drugs were not yet tested in view of possible interactions, we studied their effect on circulation and cardiovascular reflexes in eight healthy volunteers. When the drugs were absorbed from the mouth mucosa, the decrease in the heart rate during deep breathing was observed already 15 minutes after the intake of drugs. The subjects started to feel relaxed; later on they had pleasant feelings and felt sleepy. There were no undesirable changes in the heart rate or blood pressure. In the three drug combination with metripranolol, the decrease in the heart rate was more marked. The tests in volunteers were without any undesirable effects and both combinations may, therefore, be given to selected high risk subjects, e g. convalescents from myocardial infarction. Randomized trial to prove the preventive effect already started.

Adult↗

Renal vein thrombosis and subsequent syndrome of the vena cava inferior.

A case of what most probably was idiopathic thrombosis in the accessory and principal vein of the right kidney with the subsequent vena cava inferior syndrome is reported. The disease was complicated by clinically insignificant pulmonary embolisms. Needle biopsy discovered a fibroproductive chronic inflammatory process in the renal interstitium. Paramount diagnostic importance was attributed to retrograde cavography of the inferior vena cava.

Adult↗

[The effect of terlipressin (Remestyp Spofa) on hemodynamic parameters in patients with portal hypertension associated with liver cirrhosis].

Remestyp Spofa is used in wide clinical practice, among others also in the comprehensive treatment of acute haemorrhage from oesophageal varices. To patients with portal hypertension, oesophageal varices associated with cirrhosis of the liver by means of an infusion pump Remestyp was administered, 13.4 micrograms/1 kg body weight for one hour. By means of a Doppler flowmeter the rate of the blood flow and the blood flow through the trunk of the portal vein was assessed before, at 10-minute intervals during infusion, and during the 90th, 120th and 150th minute. After administration of the drug no significant effect on the investigated parameters was recorded. Therefore in the same group of patients by means of a catheter before and after infusion the following parameters were assessed: central venous pressure, pressure in the pulmonary artery, cardiac minute output, pressure in the free and wedged hepatic vein. Simultaneously changes of the systemic blood pressure were investigated. After Remestyp a significant rise of the systemic blood pressure was recorded, a rise of the central venous pressure and the pressure in the pulmonary artery. The minute volume declined slightly. The pressure in the free and wedged hepatic vein rose. The authors assume therefore that the direct effect of Remestyp on the portal circulation is not haemodynamically significant. The favourable haemostyptic action of Remestyp in patients with haemorrhage from oesophageal varices is rather due to an increased tonus of the oesophageal sphincters. With regard to the very satisfactory experience with the administration of nitrates in this indication their combined administration with vasopressin or its derivatives is considered.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamics↗

A brief account of Far East medicine.

The analysis of the historical aspects of the development of the meridian system the curative points of which had been discovered in the course of centuries evidently shows the meridians to have been set up more as a methodological and didactic aid rather than as a result of exact research. Classical acupuncture then represents a therapeutic method in terms of Chinese philosophy it is based on, formulated and dependent on the integral idealistic thought of that time in which philosophy, medicine and other natural sciences constitute a closed system.

Acupuncture Points↗