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Biomedical subjects

V Horák

Publications and source records attributed to V Horák.

At least 19 recordsLinked to original sources
PubMed1996

Ultrastructural demonstration of glucose-6-phosphatase activity and glycogen in skeletal muscles of newborn piglets with the splayleg syndrome.

The ultrastructural localization of glucose-6-phosphatase activity and glycogen were investigated in the longissimus dorsi and biceps femoris muscles of normal and splaylegged newborn piglets. Significant differences were ascertained in the distribution of the reaction product of glucose-6-phosphatase activity between the two groups of animals. A fine precipitate was found in the sarcoplasmic reticulum and in the perinuclear cisternae of normal piglet muscles. In splaylegged muscles, variable deposits of coarse reaction product were observed within the extremely dilated cisternae of sarcoplasmic reticulum at their periphery. Moreover, both longitudinal and transversal ultrathin sections of these muscles showed a reduced number of myofibrils and an increased accumulation of glycogen (especially within the large extramyofibrillar spaces) in comparison with muscles of normal piglets.

Animals↗
PubMed1995

M-twist expression inhibits mouse embryonic stem cell-derived myogenic differentiation in vitro.

The mouse M-twist gene codes for a basic helix-loop-helix protein which was shown to be inhibitory for differentiation of myogenic cells in culture. Mouse embryonic stem (ES) cells of line BLC6 efficiently differentiating into skeletal muscle cells when cultivated as embryo-like aggregates (embryoid bodies) were stably transfected with the plasmid pME18s-twist containing the M-twist gene under the control of the modified SV40 early promoter SR alpha. Two pME18s-twist-expressing clones showed delayed and reduced skeletal muscle cell differentiation depending on the level of exogenous M-twist expression compared to control cells. By morphological analysis using phase contrast microscopy and hematoxylin-eosin staining, the development of first myocytes and formation of myotubes in embryoid body outgrowths of these clones were found to be delayed for about 3 days in comparison to control cells. Immunofluorescence studies with a monoclonal antibody against sarcomeric myosin heavy chain revealed that myogenic cells appeared in so-called myogenic centers showing a reduced number of myocytes and myotubes in the M-twist-expressing clones. Using RT-PCR analysis the expression of the skeletal muscle determination genes myf5, myogenin, and MyoD as well as muscle-specific genes coding for the gamma-subunit of the nicotinic acetylcholine receptor and the cell adhesion molecule M-cadherin were found to appear with a delay of at least 1 to 4 days in the pME18s-twist-transfected cells during the development of embryoid bodies. We conclude that the constitutive expression of the mouse M-twist gene during ES-cell-derived differentiation has an inhibitory effect on skeletal muscle cell development depending on the level of exogenous M-twist expression.

Animals↗
PubMed1995

Fibre type differentiation during postnatal development of miniature pig skeletal muscles.

Histochemical differentiation of 12 skeletal muscles with a different fibre type composition was studied in miniature pigs from 80 d of gestation to 1 year of age. Two fetal myofibre types were distinguished at 100 d of gestation by the mATPase reaction after acid preincubation. The staining for oxidative enzyme activities showed no conspicuous differences between fibres up to the 6th day after birth. Starting from this age it was possible to distinguish 3 fibre categories: SO (slow-twitch oxidative); FOG (fast-twitch oxidative-glycolytic); and FG (fast-twitch glycolytic). A characteristic cluster distribution of the 3 fibre types was observed in all studied muscles with the exception of the masseter muscle which consisted only of the type SO and FOG fibres with a mosaic arrangement. The frequencies of both SO and FG fibre types increased and the proportion of type FOG fibres decreased during the postnatal period. These changes could be explained by developmental transformations among the individual fibre types. The type FOG fibres converted preferably to the fibre type (SO or FG) that prevailed in the muscles of adult animals.

Adenosine Triphosphatases↗
PubMed1994

Histochemical and functional parameters in Nordic combination athletes.

Bioptic samples from the vastus lateralis muscle were analyzed in a group of Czechoslovak representatives in the Nordic combination (ski-jumping and 15 km cross-country skiing). The distribution of individual muscle fibre types (FG, FOG and SO) was detected and correlated with values obtained by motor and functional performance tests. Histochemical analysis of the bioptic samples revealed a considerably heterogeneous distribution of muscle fibre types in the group studied. No typical profilation for this sport discipline was found. Weak correlation between the proportion of fast muscle fibres and explosive strength parameters was ascertained. The correlation between the proportion of slow muscle fibres and the capacity of O2 utilization (VO2max) was statistically significant. Strong correlation between the proportion of fast twitch fibres and relative maximal strength of knee extensors (N/kg) was disclosed. A non-linear relation between the area of fast twitch fibres and vigour of take-off was found.

Adult↗
PubMed1994

[Melanoblastoma in laboratory minipigs: a model for studying human malignant melanoma].

Human malignant melanoma is a progressively growing tumour mostly with a fatal prognosis during short time. Its frequency has doubled in some states of the USA during the last few years. Surgical treatment, which is still generally used, has very low efficiency due to the numerous metastases in different organs. An animal model is a necessary prerequisite to develop a new therapy methods. We have recorded primary cutaneous malignant melanomas as well as extensive metastases in the visceral organs in darkly pigmented laboratory minipigs. The primary skin tumours were mostly multiple and they showed a tuberous nodular form. The regular occurrence of tumours in a progeny of three specific mating types suggests the existence of genetic predisposition to malignant transformation. We discuss the use of this animal model for further studies and treatment of human malignant melanoma by our ischemization technique developed previously.

Animals↗
PubMed1992

A contribution to the model of biliary infection in rats.

The model of biliary tract infection induced in rats given suspension of E. coli into the bile duct is described. To prevent leakage of microorganisms after the administration, a temporary ligation of the bile duct followed. Contemporary groups of sham-operated and control rats (given saline by intrabiliary injection) were compared to assess the significance of the changes. The effect of biliary infection was concentration dependent. If 0.1 ml of the concentration containing 10(2), 10(3) and 10(6) colony-forming units/ml was injected, the mortality of rats reached 8%, 57% and 65%, respectively within 24 h. Blood and bile cultures from all dead animals grew E. coli. To evaluate the effect of chronic biliary infection, the concentration of 10(2) colony-forming units/ml was used. Serum concentrations of total and conjugated bilirubin, cholesterol and creatinine, activities of S-alanine-aminotransferase, S-aspartate-aminotransferase, alkaline phosphatase, the count of leucocytes in blood, total body weight with weight of the liver were investigated on days 1, 4 and 12 after the treatment. The results showed: an increase in leucocytes (21 +/- 4.2 10(9)/l, p less than 0.02 vs control animals) on day 4, an augmentation of serum cholesterol on day 1, (2.1 +/- 0.9 mmol/l, p less than 0.02 vs control animals), the presence of E. coli in blood on day 1 and its persistence in the bile on days 1, 4 and 12. Except the bile, all of the other symptoms were reversible by day 12.

Animals↗
PubMed1991

A new approach in radionuclide imaging to ureteric peristalsis using 99Tcm-MAG 3 and condensed images.

A new method for the evaluation of ureteric peristalsis is described. Standard, dynamic renal scintigraphy was carried out using 99Tcm-MAG 3 in 59 patients. Time-activity curves and condensed images over the ureter area were created simultaneously. A six-grade scale (O-V) was chosen for the classification of ureteral function. The results obtained were compared with parameters of renographic curves and other clinical findings. In a group of 13 patients, two different renal radiopharmaceuticals were used: 131I-OIH and 99Tcm-DTPA. The results show that the new method is suitable for the assessment of ureteral disorders, and has some advantages compared with previously described methods. 99Tcm-MAG 3, with a better target-to-background ratio compared to 131I-OIH and 99Tcm-DTPA, is the most suitable radiopharmaceutical for this purpose.

Adult↗
PubMed1991

[Colicinogeny in nonspecific intestinal inflammations and colorectal cancer].

Colicins are proteinaceous substances produced by Escherichia coli strains and related bacteria of Enterobacteriaceae family. They are considered to be an important factor in preserving the balance of the intestinal microflora. Their antibiotic action on susceptible bacteria is supplemented with cytotoxicity for several pro- and eukaryotic cells. The large bowel is a natural site of their action. Besides of enhancing oxidoreductive activity of leukocytes in vitro, colicins are also believed to influence inflammatory reaction in vivo. For these reasons, the first part of the present work was concerned with studying colicinogeny in nonspecific inflammatory bowel diseases (IBD). No significant difference has been found out in colicinogeny between a total of 93 IBD-related and 160 healthy controls. In testing leukocyte migration inhibition, colicins of autologous E. coli were used as antigens. The migration index out of normal range showed 36% patients with ulcerative colitis (5/14), 80% patients with Crohn's disease (12/15), and only one clinically healthy control subject (1/16; 6%). The obtained results are considered to be proof of cellular hypersensitivity of IBD patients to colicins of their own E. coli strains. In several colicins the antitumorous effect has been reported in both the in vitro and in vivo experimentation. The second part of this work was concerned with colicinogeny in colorectal cancer. Colicinogenic E. coli were evidenced in 42 subjects (40%) from 105 patients with colorectal carcinoma. Controls showed colicinogenic E. coli in 102/160 clinically healthy subjects (64%), and the difference was as significant as p less than 0.05. In colorectal cancer group, the subjects with proved colicinogeny showed lesser amounts of colicinogenic E. coli strains in contrast with non-colicinogenic ones. In colorectal cancer patients with colicinogenic E. coli strains, B and M colicins were of most frequent occurrence in them no antitumorous effect has been experimentally stated. If changes of colicinogeny were only either the manifestation or consequence of tumor disease, so both the presence or absence of colicinogenic E. coli would have been dependent of clinical patients's condition, stage of disease (in accord with Dukes) or correlated with the tumor markers. For these accounts, a total of 28 colorectal cancer patients underwent a colicinogenic study. However, no colicinogeny dependence was evidenced of either clinical condition or Dukes stage, showing no correlation with any of cancer markers investigated (carcinoembryonic antigen, CA 19-9, alfa-1-fetoprotein, alfa-1-orosomucoid, Cancer serum index, sialic acid, lysozyme).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

Characterization of coagulase-positive staphylococci isolated from free-living birds.

A total of 129 coagulase-positive staphylococcal strains were isolated from the nasopharyngeal region of free-living birds--81 (16%) from 501 birds of prey, 29 (25%) from 117 water birds, and 19 (2%) from 937 pheasants. Staphylococcus aureus and Staphylococcus intermedius were identified in 64 (79%) and 17 (21%) strains from birds of prey, in 1 (3%) and 28 (97%) strains from water birds, and in 4 (21%) and 15 (79%) strains from pheasants, respectively. Of the total number of the 69 S.aureus strains 45 (65%) could be biotyped. Biotype D prevailed in the strains from birds of prey. Among all the 60 S.intermedius strains 41 (68%) biotype 1 and 19 (32%) biotype 3 strains could be recognized. Biotype 1 predominated in strains from water birds and pheasants, while biotype 3 in strains from birds of prey. Resistance to antibiotics was recorded in 8 (12%) S.aureus and 5 (8%) S.intermedius strains only. Fifty-six (81%) of the 69 S.aureus strains could be typed with human phages, 30 (44%) with bovine and 41 (51%) with chicken phages. It is evident that the host range of Shimizu's (CH) phages involves not only S.aureus from chicken but also from any other birds. None of these strains was typable with canine phages. Out of the 60 S.intermedius strains 45 (75%) were lysed with Blouse and Meekins' canine phages. When human, bovine, and chicken phages were used, all the 60 strains were completely resistant.

Animals↗
PubMed1990

Inhibition reactivation myofibrillar ATPase technique for demonstration of three fiber types in a single cryostat muscle section.

An inhibition reactivation technique was used for histochemical staining of human skeletal muscle sections. Myofibrillar ATPase activity was inhibited by sodium hydroxymercuribenzoate (2.5 mM in 0.1 M Tris-HCl buffer, pH 7.2-7.5, 30 min) and successively reactivated by cysteine which was added to incubation solution (10 mM cysteine-HCl, 2.5 mM ATP-disodium salt, 50 mM potassium chloride and 27 mM calcium chloride in barbital buffer, pH 9.4, 35 min at 37 C). This technique allows the distinction of three fiber categories with different staining intensities in single cross-section. Dark, intermediate and light fibers correspond to IIB, I, and IIA types, respectively. Storage of air dried sections in the freezer at -20 C for one month had no influence on staining characteristics.

Adenosine Triphosphatases↗
PubMed1990

[Clinical evaluation of a new radiopharmaceutical agent 99mTc-mercaptoacetyltriglycine (MAG3)].

In the present clinically oriented study the authors checked the properties of 99mTc-mercaptoacetyltriglycine (MAG3), the new radiopharmaceutical for dynamic scintigraphy of the kidneys, in a group of 30 patients. They positively value particularly the high quality of visualization of the parenchyma and the urinary tract, the pharmacokinetic properties similar to those of 131I-orthoiodhippurate and the capability of representation of the kidneys with their markedly decreased function. They examined the take-up of the pharmaceutical in the liver, which is slightly more marked with the worsening tubular function and partly depends also on the length of the time interval between the preparation and administration of MAG3. No significant changes were found in the clinical and principal laboratory parameters after its administration. In conclusion, the authors point out to advantageous properties of the novel radiopharmaceutical for clinical use in our conditions.

Adolescent↗
PubMed1990

[The significance of a new radiopharmaceutic agent, 99mTc-mercaptoacetyltriglycine (MAG 3), in the diagnosis of diseases of the kidneys and urinary tract in children].

Using the method of dynamic scintigraphy of the kidneys by means of a new radiopharmaceutical preparation, 99mTc--mercaptoacetyltriglicide [MAG 3], the authors examined 35 children with various urological and nephrological diseases. In indicated cases the examination was supplemented by administration of a diuretic, further projections or indirect mictional cystography. The authors assessed normal parameters of functional curves and their normal extent in a group of 18 healthy kidneys. They did not find a significant difference, as compared with results obtained by means of 131I-OIH. The assessed values of global clearance attained 66% of the 131I-OIH clearance values. In 60% of the patients the visualization of the parenchyma and in 80% the visualization of the efferent urinary pathways was better than when 99mTc-DTPA was used. In all instances the scintigrams were better than when 131I-OIH was used. The new radiopharmaceutical preparation combines the advantages of technetium-labelled preparations and the favourable pharmacokinetic properties of hippuran. It is suitable for quantification of tubular secretion. It is superior to hitherto used substances as regard the quality of visualization and in particular the lower radiation load. Therefore it is particularly suited for paediatric practice.

Adolescent↗
PubMed1989

The tissue distribution of Ia- and IgM-positive cells in adult and newborn miniature pigs.

Distribution of Ia- and IgM-positive cells was compared in tissues of adult and newborn miniature pigs, using indirect immunoperoxidase and immunofluorescent techniques with monoclonal antibodies. The different distribution patterns were found mainly in adult jejunum and kidney. Both IgM- and Ia-staining were ascertained in the lamina propria between the Lieberkühn crypts and in the lymphoid follicles of the jejunum. Moreover, IgM-positive cells were demonstrated in the crypts while Ia-reaction was seen in the lamina propria of the villi. In the kidney, IgM-staining was limited to the glomeruli. On the contrary, a distinct Ia-reaction was found mainly in intertubular structures. Small differences in IgM- and Ia-positive cell distribution were also noted in the mesenteric lymph nodes and in the spleen. Developmental changes of the adult distribution patterns (chiefly that of IgM-positive cells) were found in all tissues studied at 2 days of age.

Aging↗
PubMed1989

Experimental devascularization (devitalization) of the rectum and sigmoideum.

In 6 laboratory pigs, devascularization (devitalization) of the rectum and the adjacent part of the sigmoideum was carried out by the vasa rectalia cranialia et media ligatures with simultaneous aboral closure of the rectum at the base of the lesser pelvis and oral closure at the borderline between the rectum and the sigmoideum. The devascularized rectum was not removed but left in situ. Terminal colostomy was established. Laparotomic revision was carried out after 12 weeks, colostomy was removed and continuity of the intestine was reestablished by insertion anastomosis, by suture of the end of the colon to the anal mucosa and skin. In further two pigs, devascularization of the rectosigmoideum was carried out with colostomy and reconstruction was carried out after 12 weeks by procto-sigmoideo-anastomosis. In another 2 animals, devascularization was carried out on the lower part of the sigmoideum and continuity was immediately renewed by end-to-side sigmoideo-sigmo-ideoanastomosis. All revisions indicated that the devascularized necrotic segment shrank to form a minute fibrous tissue residue, anastomosis was patent and continence was retained for colo-proctoanastomosis. The described techniques are technically simple and could be employed as palliative surgical methods for inoperable tumours in the region of the rectum and lower part of the sigmoideum.

Anal Canal↗
PubMed1989

Histochemical fiber types in the thigh muscles of 4 chicken inbred lines.

Distribution, frequency and diameter of fiber types were ascertained in the thigh muscles of I, C, W and M chicken inbred lines. The iliotibialis posterior muscle is composed of FOG and FG types uniformly distributed over the whole muscle cross-section. Three fiber types are demonstrated in the sartorius and semimembranosus muscles. In the superficial regions, the FOG and FG types are present only. Avian SO type appears down into the depth of the muscles. The frequency of this type and FOG type gradually increases in this direction whereas the proportion of FG type decreases. Semimembranosus muscle shows generally higher percentage of FOG fibers and lower frequency of remaining two types. Differences between inbred lines in fiber type frequencies are mostly insignificant. However, the M line with the highest live and muscle weights shows larger fiber diameter of FG and FOG types than I, C and W lines.

Animals↗
PubMed1988

Changes of clinical biochemical values after bilateral nephrectomy and allotransplantation of the kidney in pigs.

In a series of 10 healthy pigs, the normal ranges of the following biochemical parameters in blood serum were assessed: creatinine, urea, mineralogram (Na, K, Cl), uric acid, bilirubin, total protein, cholesterol, blood lipid level, thymol turbidity reaction and activities of alkaline phosphatase, alpha-amylase and transaminases. The changes of these values were followed up in two pigs after bilateral nephrectomy and in 18 pigs subjected to orthotopic allotransplantation of the kidneys. The examination confirmed that creatinine and urea are the most important values with a prognostic impact. However, other biochemical values signalize also renal dysfunction. In the mineralogram, values of Na and K ions are important indicators. Deterioration of renal functions was associated as a rule with a decline of alpha-amylase and alkaline phosphatase. The other examinations did not display any marked changes during renal damage.

Alkaline Phosphatase↗