Biomedical subjects
Publications and source records attributed to M Dvorák.
Recombinant baculoviruses expressing the v-myb and c-myb genes in infected insect cells were constructed. The electrophoretic mobilities of their immunoreactive products were the same as those of the authentic Myb proteins from chicken cells. The system provides a convenient source of relatively large amounts of v-Myb or c-Myb for in vitro binding studies.
In 59 subjects (25 men and 34 women) with confirmed Crohn's disease 91 sonographic examinations were made, using dynamic records by means of a sector probe with a frequency of 3.5 and 5 MHz. The disease had persisted on average for 7.1 years. A positive sonographic finding was recorded in 68% of the examined subjects, incl. 42% where the finding on palpation of the abdominal cavity was negative. During examination the following typical findings were recorded: the symptom of a tubular structure with a thickened intestinal wall (frequency 77.5%), cockade symptom (65%), convolution of the loops (62.5%), congestion in the intestinal loops (10%) and abscess in the abdominal cavity (7.5%). Ultrasonography is a significant diagnostic method which can help in the differential diagnosis of resistance on palpation and in the follow up of the disease and the effect of therapy in patients with Crohn's disease.
Endoscopic ultrasonography is a useful combination of endoscopy and abdominal ultrasonography. It visualized in detail the wall of the digestive tract and is thus indicated for the diagnosis of pathological processes of the wall and its close surroundings, in particular the differential diagnosis of tumours, assessment of their size and operability. The method has become available also under our conditions. The present paper deals with its technique and informative value.
cDNA of a subgenomic v-myb mRNA from AMV-transformed BM-2 cells was cloned. Sequencing of the 5' end of this cDNA revealed the structure of both AMV leader and the splice junction in v-myb message. The leader is a novel variant of known avian retrovirus leaders. The long open reading frame in the cloned cDNA starts with six gag-derived codons spliced to the myb-specific sequence.
In 36 subjects with pancreas divisum an ultrasonic examinations of the pancreas were made after filling the stomach with 600 ml of fluid. In 27 subjects (75%) it was possible to evaluate the entire pancreas reliably, incl. the area of the dorsal segment. The gastric filling and positioning of the patients during examination improved in 47% the quality of the visualization, in particular in the left half of the pancreas. In three patients sonography revealed marked inflammatory changes in the entire gland. The applied examination procedure protracted the examination time of the pancreas to 30-40 minutes. Aimed ultrasonic examination with gastric filling is recommended as part of the examination procedure in subjects with pancreas divisum.
Using the method of gas chromatography on a Carlo Erba 2531 apparatus in Base's modification, the authors identified serum fatty acids of mothers (n = 23) and premature infants (17 girls and 6 boys). The mean birth weight was 2224.3 (800-2650 g), the mean gestation age 34 weeks (28-37 weeks). The fatty acid levels were compared with fatty acid levels of control mothers (n = 7) and control healthy neonates born at term (n = 15). Individual fatty acids were expressed as the ratio in the total volume of fatty acids (100%). The neonates and their mothers were divided into three groups. The most numerous group (n = 12) are mothers who lost the amniotic fluid prematurely (6 hours-12 days), mothers under the influence of Partusisten (n = 10); the third group is formed by mothers treated with ATB (n = 8). In these groups the authors assessed, as compared with controls, the rise of the saturated fatty acid ratio, in particular short-chain fatty acids. The greatest increase was recorded in mothers and children under the influence of Partusisten. The ratio of mono- and polyunsaturated n-6 fatty acids was not altered in the infants, there was, however, a marked reduction of the n-3 fatty acid ratio which are known to play an important role in the regulation of immune responses and to have an anti-inflammatory effect; they are also important for the development of the CNS and retina.(ABSTRACT TRUNCATED AT 250 WORDS)
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Location of thiamine pyrophosphatase activity as a marker of the Golgi apparatus was studied ultracytochemically in mouse oocytes with germinal vesicle (OGV), oocytes at metaphase I (OMI) and oocytes at metaphase II (OMII), and further in cells of the respective cumulus oophorus serving as comparative objects. TPPase activity in cumulus oophorus cells and in OGV was found exclusively in the Golgi apparatus. In OMI the reaction product of TPPase activity was observed in isolated smooth vesicles, and in only one case in structures identifiable as the Golgi apparatus. In OMII the occurrence of TPPase activity was also recorded in isolated smooth vesicles in cortical cytoplasm and further, exceptionally, in smooth concentrically arranged vesicles or tubules. The TPPase activity was not present in vesicular complexes. The results have shown that after the resumption of meiosis the occurrence of the reaction product of TPPase activity drops abruptly due to the reduction of the Golgi apparatus. Changes affecting the Golgi apparatus after the resumption of meiosis are related to the loss of the nucleus after the germinal vesicle breakdown.
The efficiency of preventive administration of silymarin and of silymarin medication were tested in dogs suffering from CCl4 intoxication of liver. Sixteen dogs of the Beagle breed at the age of 8 to 10 months and of the weight 11.5 to 14.0 kg were divided into four groups with four animals each. Those groups were administered per os a single dose of CCl4, 0.35 ml per kg liveweight contained in sunflower oil. The intact control groups was given sunflower oil free of any additive. Silymarin was administered per os in the form of suspension in the Dorfman reagent twice a day at the dose of 100 mg per kg. Silymarin was administered to the animals of the treated group four days after intoxication, to those of the preventively treated group four days before intoxication. The intact control group and the CCl4 intoxicated control were administered the pure Dorfman reagent. Pure CCl4 induced a significant increase in the AST and ALT activity in 12 and 24 hours after administration, and histological lesions in the liver--vacuolization of hepatocytes and necrobiosis of nuclei. The curative effects of silymarin on these changes were low. The protective effects of silymarin were manifested by the significantly lower AST and ALT activities in the 12th and 24th hour of the trial and by the insignificantly lower extent of lesions in liver parenchyma if compared with the control CCl4 intoxicated group.
The efficacy of inactivation of aflatoxin B1 (AFB1, 2.0-2.6 mg per kg) in aqueous medium in exposure to 21 chemicals or their mixtures for two hours and for two days was evaluated by measuring the extracts on a fluorescence spectrophotometer. Reduction to less than 10% of the original AFB1 content within two hours was recorded when the medium contained 1.5% potassium permanganate, 2.5 and 5% Chloramin B (Lachema) or soda, and when there was 5% ammonia heated to 60 degrees C, 5% sodium hydroxide, potassium hydroxide or calcium hydroxide, or 50% chromosulphuric acid. AFB1 and other fluorescing metabolites were completely destroyed after two days of exposure to a 5% ammonia solution heated to 60 degrees C for the first two hours and after two days of exposure to 5% Chloramin B, 5% soda, 5% calcium hydroxide, 50% chromosulphuric acid, and mixture of 2.5% sulphuric acid with 0.75% potassium permanganage. Acids used alone had the lowest effectiveness.
The nucleotide sequence of an 8.2-kb DNA fragment from the 5' proximal part of the chicken myb proto-oncogene spanning 1761 nucleotides upstream and 6436 nucleotides downstream from a presumed c-myb initiation codon was determined. A 3.3-kb G + C-rich region found in this sequence had also other features characterizing CpG islands, i.e. no CpG underrepresentation and lack of CpG methylation. In haematopoietic tissues c-myb mRNA synthesis starts in two major regions of the CpG island, namely 98 to 108 and 143 to 145 nucleotides upstream from the c-myb initiation codon. These two regions are in or close to the 124-bp evolutionarily conserved element located in the middle part of the CpG island. No alternative splicing of the 5' end of c-myb mRNA suggested earlier (1,2) was observed. The c-myb promoter contains neither TATA nor CAAT box-like structures at the usual positions. Instead, numerous potential Sp1 factor binding sites were found both upstream and downstream from the transcription initiation sites. Moreover, consensus v-myb protein DNA-binding sites were revealed in the promoter region and in sequences downstream from it.
Admixture for 14 to 26 days of concentrations between 1 mg/kg to 250 mg/kg of polychlorinated biphenyls, Delor 103, 105, and 106 (Chemko, Strázeke) to ready-mixed feedstuffs was studied in 5 experiments for its effects on 71 piglets and store pigs. Neither growth nor general health were in any way impaired. Polychlorinated biphenyls produced different effects upon vitamin A, vitamin E, and ascorbic acid levels in different organs. Vitamin A concentrations in blood serum, for example were reduced by 100 mg/kg and 250 mg/kg of Delor 105 as well as by 250 mg/kg of Delor 103. Liver levels were not significantly depressed. No changes were recordable from vitamin E levels in blood serum and liver. Ascorbic acid saturation of the organism was positively affected. Its concentrations and overall levels in the liver in all experimental groups were higher than those in all controls. Significant rise of ascorbic acid concentrations in blood serum, urine, and kidneys occurred merely in response to 100 mg/kg and 250 mg/kg of Delor 105 as well as to 250 mg/kg of Delor 103. No adverse effect of tissue-borne residues of polychlorinated biphenyls on the status of administered vitamins was recordable 1 to 4 months after termination of experimental supply. Feed intake with 1 mg/kg of Delor 105, which was equivalent to increased natural contamination, did not cause any negative phenomena in any of the probands.
The adsorption of aflatoxin (AF) B1, contained in aqueous medium or in synthetic medium left after the cultivation of Aspergillus parasiticus NRRL 2999, was studied in two samples of bentonite, two samples of natural zeolite, and three kinds of adsorption coal added to water, to saline, to the blood serum of pigs, to the stomach fluid of pigs or rumen fluid of cows at concentrations of 5 to 50 mg per litre. Unlike retinol-propionate and beta-carotene, AF was readily adsorbable in vitro. The initial concentration of 3.6 mg or 18 mg AFB1 per litre was reduced to 0.3-27% after exposure to 50 g of adsorbent; this reduction was greater when the AFB1 was tested in the cultivation medium and the maximum reduction was recorded when adsorption coals was involved. The effectiveness of zeolite was lower in media containing nitrogen compounds and in those cases when its doses were low. The average AF retention in the adsorbents, calculated after the determination of desorption by chloroform extraction, was 72% of the original content in the medium in the case of adsorption coals, 66% in bentonite, and 60% in zeolite.
The authors analyze caused and indications for prostheses of bodies of cervical vertebrae. As caused they mention bone tumours, metastases, benign bone tumours and injuries. For operation they indicate patients with neurological symptoms and instability of the spine. For prostheses they use bone grafts from the blade of the ilium. They insert the graft during traction, as described by Crutchfield and do not routine fix it. After operation they immobilize by "Minerva" for three weeks. The method is in case of metastases and bone tumours only palliative, but improves the patients' mobility and prevents the development of early neurological complications.
Group of 48 patients was ultrasongraphically examined for suspicion of a pathological process in the gallbladder and bile passages region. Because of inadequate depicting spamocholeretic agent Mendiaxon was administered. In slow i. v. administration no side effects were observed. Improvement of the gallbladder picture was scored in 51.4%, bile passages in 50% of investigations. Mendiaxon administered during the examination itself represents possibility how to influence successfully ultrasonographic diagnostics.
This ether oxim derivative of erythromycin A is an easy to absorb oral antimicrobial somewhat less effective in vitro than erythromycin. At relatively low MIC's it is active against staphylococci, streptococci, pneumococci, branhnamella and chlamydiae, higher concentrations are needed against enterococci and some strains of H. influenzae. Roxithromycin is also reported to have a very good effect on campylobacters, many anaerobic bacteria, Toxoplasma gondii, Treponema pallidum, Mycoplasma pneumoniae and Legionella pneumophilla. Its half-life in the serum of healthy individuals ranges from 9 to 16 hours. Maximum serum concentrations at 2 oral doses of 150 mg a day are reached at 3 to 4 days and vary from 5.5 to 11.1 mg/l. The distribution of roxithromycin in body tissues is excellent. In a group of 57 patients treated for various infections of clear etiology the positive therapeutic effects resulting in the state of bacteriological negativity was reached in 86% of cases. Roxithromycin can be recommended as a drug of choice in mild or less severe cases of infection caused by agents sensitive to this antimicrobial. Its excellent tolerance makes it especially well suited for use in pediatric practice.
The 18-kb BamHI fragment of the chicken chromosomal DNA derived from the 5' end of the myb proto-oncogene has been cloned. The 5' part of this clone represented by a 7.2-kb BamHI-EcoRI fragment has been analysed by means of restriction mapping, which revealed the existence of about 2.5 kb of the CpG dinucleotide-rich sequence within this fragment. A short probe prepared from the CpG-rich sequence hybridizes with the 3.6-kb c-myb mRNA. Based on our results and published c-myb cDNA sequence, we conclude that the cloned fragment contains c-myb promoter.
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