Biomedical subjects
P Popov
Publications and source records attributed to P Popov.
[Stimulants and addiction].
Stimulants (methamphetamine) produced illegally in domestic laboratories play today - key role on the drug scene in the Czech Republic. In the past, however, a similar place was held by some preparations used (though to a limited extent) lege artis. At present we can observe an increased interest in stimulants in both spheres-on the mentioned drug scene as well as in medicine. The article deals in particular with the second sphere, i.e. the problem of the addictive character of stimulants prescribed by physicians.
Comparative electrophoretic investigation of Rana temporaria, R. graeca and R. dalmatina.
The results of comparative electrophoretic analysis on muscle esterases, superoxide dismutases, lactate dehydrogenases, malate dehydrogenases-NAD-dependent, phosphoglucomutases and myogens in the brown frogs Rana temporaria, R. graeca and R. dalmatina are described. The coefficient of similarity and indices of divergence among the species investigated were estimated. It was established that in relation to the protein systems analysed R. graeca differed more significantly from R. dalmatina than from R. temporaria. It is suggested that the higher electrophoretic similarity of R. temporaria and R. dalmatina is a result of a greater divergence of the latter in comparison with R. graeca.
[Laparoscopy and laparoscopic echography in the diagnosis and staging of gastrointestinal carcinomas].
The clinical relevance of laparoscopy (LS) and laparoscopic echography (LSEG) in diagnosing and staging gastrointestinal carcinomas is assayed in the light of diagnostic methods in current use. The study covers 257 patients undergoing LS, and 23-LSEG. For the purpose a rigid 7.5 MHz echolaparoscopic probe is used. In 16 per cent of the cases LS fails to resolve the basic diagnostic problems faced, whereas in 35 per cent it alters completely the preliminary clinical diagnosis. In over 90 per cent of cases LSEG supplements or modifies the laparoscopic diagnosis. Emphasis is laid on the role played by LSEG in defining the loco-regional stage of gastric and colorectal carcinomas, as well as on the contribution of the method to establish pancreatic carcinomas not lending themselves to resection. What is more, LSEG demonstrates inoperable cases by detecting small, unsuspected metastases, not prominating above the hepatic surface.
Long-term treatment with different calcium- and calmodulin-antagonists induces changes in rat brain alpha-adrenoceptors.
1. The binding characteristics (Bmax and Kd) of the alpha-adrenoceptor radioligand [3H] WB4101 in crude membrane fraction (fraction P2) from cerebral cortex were studied after 13-day oral treatment of male Wistar rats with the Ca(2+)-antagonists nifedipine (20 mg/kg), verapamil (50 mg/kg), flunarizine (10 mg/kg) and with the calmodulin-antagonist trifluoperazine (TFP) (3 mg/kg). 2. A significant reduction of the binding sites (Bmax) for [3H] WB4101 was established after the three Ca(2+)-antagonists as well as after TFP treatment. 3. Different changes in the affinity constant (Kd) of brain adrenoceptors were observed depending on the type of the Ca2+ or CaM-antagonist used: nifedipine did not change the Kd value, verapamil and TFP decreased whereas flunarizine increased the Kd value. 4. Relationships between Ca ions and alpha-adrenoceptor functions are suggested.
Changes in benzodiazepine receptors of rat brain after long-term treatment with the Ca(2+)-antagonists nifedipine, verapamil, flunarizine and with the calmodulin antagonist trifluoperazine.
1. The binding of [3H]flunitrazepam to benzodiazepine receptors in the cerebral cortex and hippocampus (membrane fraction P2) was studied after 13-day oral treatment of male Wistar rats with the Ca(2+)-antagonists nifedipine (20 mg/kg), verapamil (50 mg/kg), flunarizine (10 mg/kg) and with the calmodulin (CaM)-antagonist trifluoperazine (TFP) (3 mg/kg). 2. The changes in the binding characteristics of the benzodiazepine receptors in the frontal cortex were studied in vitro after the addition of nifedipine (10(-6) and 10(-5) M) and verapamil (10(-6) and 10(-5) M). 3. A significant decrease of the binding capacity (Bmax) of [3H]flunitrazepam was established after in vivo treatment with the three Ca(2+)-antagonists as well as after TFP, the decrease being much more pronounced in the hippocampus. 4. Changes in the affinity values (Kd) of [3H]flunitrazepam binding were found in neither of the groups. 5. No data for a direct interaction of nifedipine and verapamil with the brain benzodiazepine receptors were obtained in in vitro experiments.
[Multiple gastric aspiration biopsies combined with endoscopic and histomorphological studies].
The study includes 50 patients with duodenal peptic ulcer who are classified into 2 groups: 1 gr. of 30 patients to whom biopsy was performed twice at a 14 day interval in order to study the reproducibility of the method in relation to the histological diagnosis; II group of 20 patients served for determination of the percentage of full value biopsies suitable for diagnosis. The results showed that the histological diagnosis based on the second examination coincided with the diagnosis from the first examination in 78% of the cases and by the single examination 33% of the biopsies showed gastritis of different severity from the rest. Most of the biopsies were of full value--84%, and the material of 19 mg obtained from mean 10 biopsies to a patient was sufficient. The endoscopic control following the biopsies revealed artificial erosions of incomplete type localized in the corpus and rarely single erosions in the antrum. The difference in the percentage of antral biopsies found by gastroscopy--6% and that found by histological examination--0.6% is a proof for the fundalization of the antral glands. The proposed method for multiple aspiration biopsy is informative, noninvasive and technically easy to perform.
Cisapride and cimetidine in the treatment of erosive esophagitis.
The efficacy of cisapride, as compared with cimetidine, in the treatment of erosive esophagitis was studied in a double-blind trial. One hundred and twenty-nine patients were assigned to one of four dosage schedules: cisapride 10 mg b.i.d. (20 mg group) or q.i.d. (40 mg group), or cimetidine 400 mg b.i.d. (800 mg group) or q.i.d. (1600 mg group). Treatment lasted 8 to 12 weeks. The degree of esophagitis and the severity of diurnal and nocturnal heartburn and regurgitation were significantly (p less than 0.01) reduced in the four treatment groups. Endoscopy did not show any significant differences among the four groups, although cisapride tended to be more effective in moderate to severe esophagitis, in which cases mucosal healing (i.e. absence of erosions and ulcers) was observed in 69%, 64%, 55% and 55% of the patients treated with cisapride 40 mg, cisapride 20 mg, cimetidine 1600 mg and cimetidine 800 mg. Improvement in reflux symptoms in the two cisapride groups was not significantly different from that in the cimetidine 1600 mg group, but was better (p less than 0.05) than that in the cimetidine 800 mg patients. The severity score for all reflux symptoms had decreased by 79%, 74% (cisapride 40 mg and 20 mg), 69% and 57% (cimetidine 1600 mg and 800 mg) by the end of treatment. These results show that cisapride is at least as effective as acid-suppressing therapy in patients with reflux esophagitis, and is therefore a valuable alternative to it.
Protective effect of rioprostil on indomethacin-induced lesions of gastric and duodenal mucosa in healthy volunteers.
The protective effect of rioprostil against gastroduodenal mucosal lesions induced by indomethacin is investigated in a double-blind controlled trial on 36 healthy adult volunteers, divided into three groups. All the volunteers are treated with indomethacin, 50 mg t.d.s. during a period of 5 days. The first group is treated with placebo, the second with rioprostil, 300 micrograms, and the third with rioprostil, 600 micrograms. Endoscopies are performed before and after treatment. Blood samples for high performance liquid chromatography determination of indomethacin plasma concentrations are taken on the 6th day, before the last dose of indomethacin is administered, and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12 and 24 h after the last dose of indomethacin. It is found that in both doses rioprostil exerts a protective effect against indomethacin-induced lesions, reducing the appearance rate of erosions from 67% to 17% statistically significant in the 600 micrograms group. The bioavailability of indomethacin in the three groups does not differ significantly.
Behavioural and radioligand analysis of the effect of two new piperazine derivatives with anxiolytic properties.
The experiments were carried out on Wistar rats, using a conflict situation consisting in opposition of two motivations: positive (water drinking) and negative (electrical pain). Two newly-synthesized piperazine derivatives with proved psychotropic activity (4P-183 and GP4) were studied and compared with the classical benzodiazepine tranquilizing agent diazepam. Parallel with this, the affinity of these compounds to the benzodiazepine receptor in mouse brain was tested (radioligand binding of 3H-diazepam), as well as the changes in the characteristics of binding (dissociation constant and density of the receptors) after 14-day administration o doses equal to 1/3 LD50 of the two compounds. The results indicate the existence of anxiolytic (anticonflict) activity in both compounds. The fact that the above-mentioned derivatives do not interact with 3H-diazepam (in vitro), changing above all the dissociation constant after chronic administration, suggests predominantly nonspecific type of binding to the receptors. It is possible that their anxiolytic activity is associated with indirect interactions with one of the components of the GABA-benzodiazepine receptor complex, similar to the atypical tranquillizers.
[Emergency endoscopy in hemorrhage from the upper portions of the digestive system].
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[Differential diagnosis of jaundice].
Patients with jaundice and hyperbilirubinemia over 34 mumol/l have been examined by different methods in order to assess the diagnostic value of the methods. 340 patients were examined clinically and by laparoscopy, 168 patients and 92 healthy persons were examined by 10 laboratory indices, 639 patients--by ultrasonography, 95 patients--by scintigraphy, 116 patients--by computer tomography, 83 patients--by endoscopic retrograde cholangio-pancreatography (ERCPG), 17 patients--by percutaneous transhepatic cholangiography (PTC), 70 patients--by directed liver biopsy. In the patients with cholestasis the 5'-nucleotidase, alkaline phosphatase, glutamyl transpeptidase (lipoprotein X is positive in 92% of the patients) and cholesterol are increased most. The extrahepatic obstructions are diagnosed by ultrasonography in 94.8% of the patients (the biliary ducts are dilated), in 88.7% of the patients the localization of the obstruction and in 74.7% of the patients the cause of the obstruction are found. In parenchymal jaundice the sonography reveals the disease which has caused jaundice in 62.1% of the patients. The scintigraphy gives correct diagnosis in 50% of the patients with hepatitis and jaundice, in 78% of the patients with cirrhosis and jaundice and in 87.5% of the patients with liver cancer. The computer tomography reveals the obstructive jaundice in 94.7% of the patients and the focal processes in the liver in 96.7% of the patients. The ERCPG gives a clear picture of the biliary ducts in 72.28% and of the pancreatic duct in 83.13% of the patients with jaundice, simultaneously the biliary and the pancreatic ducts--in 45.78% of the patients and correct diagnosis in 83.1% of the patients examined.(ABSTRACT TRUNCATED AT 250 WORDS)
Determination of lithium in blood serum--a comparison between molecular absorption spectrophotometry and emission flame spectrometry.
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[Beta-adrenergic receptors in the brain, molecular mechanisms and regulation].
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[Immediate and late results following gastroscopic polypectomy].
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[Transendoscopic treatment of stomach ulcer].
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[Thanatogenesis in acute pneumopathies (anatomo-clinical forms)].
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[Vitality diagnosis in lesions of the dermis in burns].
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