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Biomedical subjects

V Volf

Publications and source records attributed to V Volf.

At least 19 recordsLinked to original sources
PubMed2003

[Helicobacter pylori infection in a group of symptomatic and asymptomatic children and adolescents in the Czech Republic].

BACKGROUND: There exist only inconsistent results of studies on the relationship between Helicobacter pylori (H. pylori) infection and functional dyspepsia and/or recurrent abdominal pain in children and adolescents. The answer could bring a comparison of the epidemiological features of H. pylori infection between children and adolescents with dyspepsia and/or recurrent abdominal pain (symptomatic) and without these symptoms (asymptomatic), living in the Czech republic. METHODS AND RESULTS: Study includes children and adolescents (2-18 years) with upper gastrointestinal symptoms visiting paediatric gastroenterology department between 1994 and 1999. Age, sex, socioeconomic level matched control (asymptomatic) group consisted of children and adolescents visiting the general paediatric service with symptoms not related to the upper gastrointestinal tract. Demographic and socioeconomic factors, including parent(s) educational level, place of residence, living conditions, type of drinking water and pets in their household were evaluated. Serum of the children and adolescents was tested for H. pylori IgG by enzyme linked immunosorbent assay. In addition, the symptomatic children and adolescents underwent endoscopic examination and biopsies from gastric antrum and corpus were taken for the quick urease test, histology/histoscopy, and H. pylori cultivation. H. pylori infection in this group was stated when at least two tests were positive. Altogether 829 children and adolescents were examined, 624 cases were symptomatic and 205 represented controls (asymptomatic). The prevalence of infection was 33% among symptomatic children vs. 7.5% among controls (OR = 6.2, p.001) and was similar among boys and girls (32% vs. 34.5%, respectively). H. pylori prevalence increased with age among symptomatic children (10% for children below 6 years and 37% between 11 to 16 years) (p.001). In contrary, prevalence tended to fall with age among asymptomatic children (11% in children below 6 years vs. 6% in children over 10 years (OR = 2.0, 95% CI = 0.7-6.2). In both groups, an inverse correlation between H. pylori occurrence and mother's educational level was observed. The H. pylori incidence was 10% among asymptomatic children who drank water from municipal water supply or from a well vs. 3% among those who drank bottled water (OR = 4, 95% CI = 1.1 to 18, p.05). CONCLUSIONS: H. pylori infection was more prevalent among symptomatic children and adolescents vs. asymptomatic children and adolescents within the same population. H. pylori incidence increased with age among symptomatic children and adolescents and tended to fall among controls, showing deep differences between the two groups. With exception of the bottled water drinking, presence of any other factor studied represented significant risk for acquiring the H. pylori infection.

Adolescent↗
PubMed2000

Mobilization and detoxification of polonium-210 in rats by 2,3-dimercaptosuccinic acid and its derivatives.

PURPOSE: To reduce retention and toxicity of the alpha particle emitter polonium-210 in rats by newly developed chelating agents. MATERIALS AND METHODS: Repeated subcutaneous chelation was conducted after intravenous injection of 210Po nitrate. For reduction of 210Po retention the treatment with vicinal dithiols meso-and rac-2,3-dimercaptosuccinic acid (DMSA), mono-i-amylmeso-2,3-dimercapto succinate (Mi-ADMS) and mono-N-(i-butyl)-meso-2,3-dimercapto succinamide (Mi-BDMA) were used. For the reduction of toxic effects of 210Po, treatment effectiveness of Mi-BDMA was compared with that of N,N'-di(2-hydroxyethyl)ethylenediamine-N,N'-biscarbodithioate (HOEtTTC, reference compound). RESULTS: Treatment with meso-DMSA and rac-DMSA altered the main excretion route of 210Po, reduced its contents in the liver but increased its deposition in the kidneys. Treatment with Mi-ADMS or Mi-BDMA increased total excretion of 210Po, mainly via the faeces. Only Mi-BDMA decreased 210Po levels in the kidneys. The effectiveness of all chelators decreased with delay in the start of treatment. In a survival study, the lives of rats treated early with Mi-BDMA or delayed with HOEtTTC were prolonged three-fold when compared with rats receiving a lethal amount of 210Po only. CONCLUSIONS: Of the vicinal dithiols examined, Mi-BDMA was the best mobilizing chelating agent for 210Po and it reduced 210Po toxicity when the treatment started immediately. However, the detoxification efficacy of the immediate treatment with HOEtTTC, observed in our previous study, was superior to that of the present result with Mi-BDMA.

Animals↗
PubMed1999

Effect of oral ZnDTPA on late effects of injected plutonium in rat.

PURPOSE: To reduce the long-term toxicity of 239Pu in rats by lifetime drinking of ZnDTPA solution and to investigate possible side-effects of the drug. MATERIALS AND METHODS: Male Sprague-Dawley rats received a single injection of 239Pu citrate, alone or plus oral ZnDTPA. Additional groups were administered only ZnDTPA. Late tissue changes were evaluated by post-mortem examination, X-rays and histologically. RESULTS: The incidence of rat bearing osteosarcoma decreased after treatment to 35% as compared with 53% in untreated controls. The proportional incidence of osteosarcomas was reduced after ZnDTPA by more than the corresponding removal of 239Pu. Unexpectedly in the male rat, mammary tumours, mostly malignant, developed in 20% of rats that received 239Pu as compared with 0.5% in the untreated controls. After a lifetime drinking solely 3 x 10(-3) M ZnDTPA the incidence of diffuse glomerulosclerosis reached 29% as compared with 10% in controls. CONCLUSIONS: In rat, protracted oral administration of ZnDTPA reduced the incidence of osteosarcomas after injection of 239Pu, even if treatment started with a delay of 1 month. In the latter case, however, more soft tissue damage was found than after treatment beginning at 4 days post-239Pu. An increased incidence of diffuse glomerulosclerosis was observed as a side effect of oral ZnDTPA only when given continuously, alone and in high amounts.

Administration, Oral↗
PubMed1997

Reduction of subacute lethal radiotoxicity of polonium-210 in rats by chelating agents.

The protective effect of N,N'-di(2-hydroxyethyl)ethylene-diamine-N,N'-biscarbodithioate (HOEtTTC) against the subacute lethal radiotoxicity of polonium-210 was investigated in a survival study and by histopathological and haematological examinations of some organs and tissues in Sprague-Dawley rats. This effect was compared with that of N,N'-diethylamine-N-carbodithioate (diethy dithiocarbamate, DDTC). In the survival study, rats injected in intravenously solely with a lethal amount of 210Po (1.45 MBq kg-1 body mass) died within 14-44 days while 90% of rats treated with HOEtTTC survived for 5 months until sacrificed. When treated with DDTC all rats died within 36-93 days. In the histopathological examination, relevant changes resulting from incorporation of 210Po were found in lymph nodes, thymus and humeral bone marrow. After the treatment with HOEtTTC no pathological changes were observed. In the haematological examination, severe reduction in blood and femoral bone marrow (BM) cell counts was revealed in rats injected with 210Po. This reduction was reversed by treatment with HOEtTTC. Treatment with DDTC led only to partial recovery of blood and BM cell count. In conclusion, under the conditions of the experiment only HOEtTTC was fully effective in reducing subacute lethal radiotoxicity of 210Po.

Animals↗
PubMed1997

Dosimetry and pathology of 237Np in female rats.

Female Sprague-Dawley rats, 10-12-week old and weighing about 240 g, were injected intravenously with 237Np-nitrate. In the toxicological study 77 rats served as controls and 28 rats per group received single doses of 5.2 and 26 kBq, respectively, per kg body weight. In addition, 12 rats of each injection level, sacrificed at defined points in time, were used for dosimetric studies. During the whole life-span the body weight and 237Np whole body-content of each animal were recorded. After death a detailed pathological examination was made of each animal in the cronical study. One day after injection 48% of the injected activity was in the skeleton, 9.3% in the liver, 3% in the kidneys and 4.4% in the rest of the organs. Whereas in all organs the activity decreased very fast, the half-life in the skeleton was about 1400 days. The bodyweights were comparable in the three groups, but the life span decreased from 800 days (control group) to 644 days after injection (26 kBq kg-1 body weight group). The main lesions in the female rats were mammary tumors (73%) and pituitary gland tumors (52%). With increasing activity the incidence of pituary gland tumors decreased and that of osteosarcomas increased from 1.3% (control group) to 32% (26 kBq kg-1 body weight group), whereas the remaining lesions showed no influence on the activity.

Animals↗
PubMed1996

Chelation therapy by DFO-HOPO and 3,4,3-LIHOPO for injected Pu-238 and Am-241 in the rat: effect of dosage, time and mode of chelate administration.

The effectiveness of the siderophore analogues DFO-HOPO (a hydroxypyridone derivative of desferrioxamine) and 3,4,3-LIHOPO (a linear tetrahydroxypyridinone) for the decorporation of 238Pu and 241Am from rat was studied. (1) Dosage-effect relationship. A similar treatment effect on Pu was achieved by single s.c. injection of 30 mumol kg-1 or by oral administration of 100 mumol kg-1 of either of the two ligands, provided the oral dose was administered earlier. In general, LIHOPO was more effective than DFO-HOPO: retention of Pu in the liver and bones was reduced by LIHOPO to < 10% of control values. No increase in renal retention of the actinides was observed. Whilst DFO-HOPO did not affect Am retention, a substantial reduction was achieved by LIHOPO. Removal effectiveness for injected LIHOPO on Pu was higher than that on Am, especially in the bones and after low ligand doses. Orally administered small doses of LIHOPO, however, mobilized more Am than Pu, both from the liver and the bone. (2) Time-effect relationship. The effectiveness of the injected ligands for Pu decreased exponentially with the time between exposure and treatment. With DFO-HOPO, the calculated half-times for decrease of mobilized fractions of Pu from the bone and liver were 5 and 12 h respectively. The effect of LIHOPO on Pu decreased much more slowly, with a half-time of 3-4 weeks. For instance, a single injection of 30 mumol kg-1 LIHOPO at 10 days post-Pu removed 30 and 50% activity from the bone and liver respectively. The removal effect of LIHOPO for Am in the liver decreased with time in the same way as for Pu but the mobilized fractions of skeletal and renal Am decreased from the first day with a half-time of only 8 and 4 days respectively.

Americium↗
PubMed1996

Treatment with 3,4,3-LIHOPO of simulated wounds contaminated with plutonium and americium in rat.

The effect of a siderophore analogue 3,4,3-LIHOPO has been investigated in rat after intramuscular injection of 238Pu, 239Pu and 241Am simulating puncture wounds. Various treatment regimens were used to remove the radioactivity from its injection site and to reduce its retention in body tissues. The local deposits could be reduced to 9% of that in untreated controls by a single local injection of 30 mumol kg-1 3,4,3-LIHOPO administered 1 day after the actinides. Tissue retention of radioactivity was most effectively reduced (to 3% of controls) by continuous subcutaneous infusion of 3,4,3-LIHOPO (3 mumol kg-1 day-1), starting immediately after the injection of actinides and continuing for 2 weeks. The administration of 3,4,3-LIHOPO in drinking water was least effective. Treatment efficacy was substantially higher with 238Pu than with an equal activity of 239Pu (the 238Pu mass, however, was almost 300 times lower than that of 239Pu). Accordingly, the biokinetics and removal of 241Am changed when it was injected with 239Pu instead of 238Pu. Continuous infusion of 3,4,3-LIHOPO (3 mumol kg-1 day-1), starting 4 and 30 days after intramuscular injection of 238Pu and 241Am reduced their femoral retention after 1 month to 20 and 60% of controls respectively; whole-body retention of 241Am was reduced to 20 and 70% of controls respectively.

Americium↗
PubMed1995

Bis-dithiocarbamates: effective chelating agents for mobilization of polonium-210 from rat.

The time dependence of organ distribution and excretion of intravenously (iv) injected 210Po was investigated after the single or repeated administration of N,N'-diethylamine-N-carbodithioate (diethyldithiocarbamate, DDTC) and three bis-dithiocarbamates: N,N'-dimethylethylenediamine-N,N'-biscarbodithioate (MeTTC), N,N'-diethylethylenediamine-N,N'-biscarbodithioate (EtTTC), and N,N'-di)20hydroxyethyl)ethylenediamine-N,N'-biscarbodithioate++ + (HOEtTTC). The biokinetics of iv injected 210Po was used as a model for the behaviour of 210Po absorbed into the blood from any other site of entry into the body. The most effective chelating agent was HOEtTTC, which was not only effective when injected subcutaneously (sc) immediately after 210Po, but also 1 h later. Toxic effects of DDTC were observed in a metabolic study when the effect of HOEtTTC was compared with that of DDTC. DDTC caused accumulation of 210Po in brain and transiently in liver. When HOEtTTC was administered, the faecal excretion of 210Po was increased from the very beginning. MeTTC, EtTTC and N-(2,3-dimercaptopropyl)phtalamidic acid (DMPA) were ineffective when the treatment started 1 h after iv injection of 210Po.

Aniline Compounds↗
PubMed1995

Combined chelation treatment for polonium after simulated wound contamination in rat.

Contaminated puncture wounds were simulated in rat by intramuscular injection of 210Po. The aim of the study was to determine the effectiveness of chelation treatment as a function of time, dosage, and route of chelate administration. Ten newly synthesized substances containing vicinal sulphydryl and carbodithioate groups were used and their effect was compared with that of chelators clinically applicable in man--BAL (2,3-dimercaptopropane-1-ol), DMPS (2,3-dimercaptopropane-1-sulphonate), DMSA (meso-2,3-dimercaptosuccinic acid), and DDTC (sodium diethylamine-N-carbodithioate). The results indicate first that complete removal of 210Po from the injection site is achieved by only two local injections of DMPS, beginning as late as 2 h after injection of 210Po. Second, many of the substances used merely induce translocation of 210Po from the injection site into other tissues. Third, a combined local treatment at the injection site with DMPS plus repeated systemic, subcutaneous, treatments with HOEtTTC (N,N'-di-(2-hydroxyethyl)ethylenediamine-N,N-biscarbodithioate), a derivative of DDTC, results after 2 weeks in a reduction of the estimated total body retention of 210Po to about one-third of that in untreated controls. In the latter case the cumulative excretion of 210Po increased from 8 to 54%, mainly via the faeces.

Animals↗
PubMed1994

[Treatment of trochanteric fractures of the femoral bone].

The authors present the evaluation of some most often methods of treatment of trochanteric fractures of femur. They analyze the group of 235 patients in the years 1987 - 1991 treated for fractures by the McLaughlin technique and by Ender nailing. The first method was performed on 121 people and the technique of Ender nailing on 97 people. The results and complications of these methods of osteosynthesis are presented in the paper. The experiences of the authors confirm the advantage of Ender nailing in treating fractures of the oldest injured patients. The Ender nailing method of osteosynthesis is the more advantageous, because the operation takes less time and is easier for patients. After Ender nailing, the possibility of functional rehabilitation and walking on crutches is greater. McLaughlin osteosynthesis of these fractures proved the more advantageous in younger injured patients.

Aged↗
PubMed1993

Relative effectiveness of dithiol and dithiocarbamate chelating agents in reducing retention of polonium-210 in rats.

Nine different sulphur-based chelators, including dithiols and dithiocarbamates, were examined for their ability to remove Po-210 from the rat. In general, treatments merely caused a redistribution of Po-210 in the body. Greatest reduction of Po-210 in blood was achieved by 2,3-dimercaptopropanol (BAL), sodium diethyldithiocarbamate (DDTC), and N-(2,3-dimercaptopropyl) phthalamidic acid (DMPA). Nearly all the compounds tested decreased Po-210 in the spleen and muscle. On the other hand, BAL and DDTC substantially increased the accumulation of Po-210 in the brain while DMPA, DMPS (sodium 2,3-dimercaptopropane-1-sulphonate) and DMSA (meso-2,3-dimercaptosuccinic acid) increased by several times the Po-210 in kidneys. A less pronounced increase of Po-210 was sometimes observed in liver (due to DDTC and DMPA) and in muscle (due to BAL and DDTC). Three of the dithiocarbamates (BGDTC, MeOBGDTC and BLDTC) did not increase accumulation of Po-210 in the brain and muscle but they reduced Po-210 in blood to a lesser degree than DDTC. A derivative of DMSA (Mi-ADMS) reduced Po-210 in blood, bone and muscle more than DMSA, but at the same time increased Po-210 in the kidney. When BAL or DDTC were combined with other agents there was a greater reduction in the whole-body burden of Po-210. Removal of Po-210 from the bone, spleen and kidneys by BAL was increased by repeated treatment. However, under similar experimental conditions the effect of a single injection of BAL on Po-210 in blood was less pronounced when the period of observation was prolonged. Total-body retention of Po-210 could not be reduced to less than 85% of the untreated controls by any of the chelators tested. In spite of this some of them (BAL, DMPS, DMSA, DMPA) could still have a useful role in reducing the toxicity of Po-210.

Animals↗
PubMed1993

Early chelation therapy for injected Pu-238 and Am-241 in the rat: comparison of 3,4,3-LIHOPO, DFO-HOPO, DTPA-DX, DTPA and DFOA.

Chelating agents were tested for removal of simultaneously injected Pu-238 and Am-241 from the rat. The effectiveness of early single chelate injections of Pu-238 retention in tissues decreased in the order 3,4,3-LIHOPO > DFO-HOPO > DTPA > DTPA-DX, and for Am-241 in the order 3,4,3-LIHOPO > DTPA-DX > DTPA >> DFO-HOPO. DTPA-DX showed a special ability to remove Am-241 from the liver. Injected 3,4,3-LIHOPO decreased the contents of Pu-238 in bone and liver to 9 and 3%, respectively, of those in untreated controls. Corresponding values for Am-241 in bone and liver were 30 and 6%, respectively, which indicates that 3,4,3-LIHOPO (unlike DFO-HOPO) is not a plutonium-specific chelator. The effectiveness of prompt single oral treatment with 3,4,3-LIHOPO and DFO-HOPO in reducing retention of actinides was comparable with that of those chelators injected with 1 h delay and at one-third of the oral dose. When 3,4,3-LIHOPO was administered by continuous infusion, a superior effect was achieved with total chelate amounts only slightly exceeding that given as single injection. The retention of PU-238 and Am-241 in bones was reduced to < 5 and 10% of controls, respectively; the contents in the liver were < 2% of controls.

Administration, Oral↗
PubMed1993

[Problems in craniocerebral injuries].

Considering the number of patients hospitalized for craniocerebral injuries, the authors found, that it is the second highest of all wound injuries, and that in the age group to 44 years, these injuries, mostly treated in the surgical departments of hospitals, are also the most frequent cause of death. Both the correct diagnosis and timely cure are essential for lowering the mortality rate and alleviating the post-injury impairment. Even thought inebriety in a larger number of patients makes the diagnosis and treatment difficult, it seems possible that in many other cases shorter hospitalization as well as a treatment on the out-patient basis, mostly by a neurologist, should be considered. This contribution focuses on isolated craniocerebral injuries. In the years 1981-90, this group of patients hospitalized in our department, reached the number 1, 135. Of which 208 (18.3%) suffered the structural damage of the brain tissue diagnosed as cerebral contusion or intracranial bleeding, 927 (81.7%) brain concussion, and 68 (6.0%) simultaneously had polytrauma.

Adolescent↗
PubMed1989

Testing of methyleneiminodiacetic-catechol and other aromatic chelating agents for decorporation of 238Pu and 241Am in rats.

The removal of 238Pu and 241Am by five chelating agents prepared in China was compared in pilot experiments with removal by Ca-DTPA and LICAM(C). The most promising substance is quinamic acid (a methyliminodiacetic polyquinoline derivative, code name 811 or 703-73), especially in combination with Ca-DTPA. However, the best over-all reduction of both 238Pu and 241Am in all the organs studied was achieved by Ca-DTPA-administered at a ten-fold human equivalent dosage.

Americium↗
PubMed1989

The efficacies of pure LICAM(C) and DTPA on the retention of plutonium-238 and americium-241 in rats after their inhalation as nitrate and intravenous injection as citrate.

The pure carboxylated catechoyl amide LICAM(C) and the calcium and zinc salts of diethylenetriaminepenta-acetic acid (DTPA), were tested for efficacy for removing 238Pu and 241Am from rats after inhalation of the nitrate or intravenous injection of the citrate. The results were compared with the efficacy of methylated LICAM(C) used in previous experiments. It was shown that: (1) after inhalation of 238Pu nitrate, DTPA was far superior to pure LICAM(C); (2) after intravenous injection of 238Pu citrate, the infusion of DTPA plus LICAM(C) was only marginally more effective than DTPA alone; and (3) after inhalation or intravenous injection of 238Pu plus 241Am, the efficacy of pure LICAM(C) was only marginally more effective than the methylated form and neither form was effective for the decorporation of 241Am. It was concluded that DTPA, at present, remains the chelating agent of choice for treating persons accidentally contaminated with transportable forms of Pu and Am.

Aerosols↗
PubMed1989

Influence of nutritional factors on 239Np and 233Pa retention in weanling rats.

The estimated intestinal absorption after a single administration of 239Np-nitrate to fasted weanling rats (about 2% of the oral dose) was ten times higher than that of 233Pa administered as the chloride. Rats drinking tomato juice, apple juice or tea instead of water had a similar retention to the control group. However, when a small amount of tea was administered immediately before 239Np, the absorption and retention values were six times lower. When animals received only milk or glucose, the whole body retention of 239Np and 233Pa increased about 20 and 200-300 times, respectively, due mainly to a very high retention in the large intestine. When rats were fed milk plus rat chow, the whole body and gut retention of 233Pa was only two and three times higher, respectively; in the other organs less 233Pa was found than in control animals. This indicates that the extremely high retention of radionuclides in the gut contents of young rats fed only milk is temporary and disappears when solid food is available.

Americium↗
PubMed1986

Chelation therapy of incorporated plutonium-238 and americium-241: comparison of LICAM(C), DTPA and DFOA in rats, hamsters and mice.

The carboxylated catechoylamide 3,4,3-LICAM(C) was tested for removal of 238Pu and 241Am from small laboratory rodents. The effectiveness of treatment was compared with that of two ligand preparations approved for clinical use: calcium-trisodium diethylenetriaminepentaacetate (DTPA) and desferrioxamine (DFOA). With early treatment and at the dosage used clinically for the decorporation of actinides with DTPA (30 mumol/kg body weight) LICAM(C) was superior to DFOA but when compared with DTPA, the effect of LICAM(C) on 238Pu was greater only in bone; as little as 1 mumol LICAM(C)/kg was as effective as 30 mumol DTPA/kg. However, in all animals treated with LICAM(C) there was a large increase in the 238Pu content of the kidney. With 241Am the effect of DTPA was always superior to that of LICAM(C). The best overall results early (1 day) after injection of 238Pu and 241Am were achieved by a combination of a single injection of LICAM(C) and DTPA with subsequent continuous administration of DTPA in drinking water. LICAM(C) affected the retention of 238Pu even if given orally; the data suggested that about 3 per cent of ingested LICAM(C) was absorbed. When the beginning of treatment was delayed, LICAM(C) became equally effective or less effective than DTPA even as far as 238Pu retention in bone was concerned, but it still increased the accumulation of 238Pu in the kidneys.

Americium↗