[The concentration of lactate in amniotic fluid in delivery under physiological course of pregnancy].

The study was carried out to establish admissible range of concentrations of lactate using standard biochemical method in amniotic fluid at first period of delivery under physiologically progressing pregnancy. The sampling included 44 women examined during first period of urgent delivery. The samples of amniotic fluid were taken during the first period of delivery using vaginal amnitomy. The concentration of lactate in samples of amniotic fluid was established using enzymatic amperometric technique. The reference values of concentration of lactate were established in the following admissible limits: 4.4-9.4 mmol per l; ratio lactate/creatinine - 17.7-79.4; ratio lactate/protein - 0.044-0.692. The admissible range of concentration of lactate and ratio lactate/creatinine and lactate/protein in amniotic fluid at first period of delivery under physiologically progressing pregnancy was established.

[Metabolic and genetic predictors of restenosis and thrombosis of arterial bioprostheses in the femoropopliteal position].

The present study was aimed at analysing the role of certain cytokines in the development of restenosis and thrombosis of biological prostheses "KemAngioprosthesis", as well as assessing the effect of polymorphic variants of genes on expression of pro- and anti-inflammatory interleukins. Group One (n=52) was composed of patients with an unfavourable outcome (prosthesis restenosis, accompanied by thrombosis in 35 patients). Group Two (n=59) comprised patients with functioning and unaltered prostheses. Group One patients were found to have a significantly higher level of the marker of chronic inflammation IgG and IL-8, amounting respectively to 22.43±0.75 mg/ml and to 6.34±1.008 pg/ml and 16.35±0.84 mg/ml (p=0.01) and 3.96±0.399 pg/ml (p=0.01) in Group Two patients. Analysing the effect of polymorphic variants of genes on expression of pro- and anti-inflammatory interleukins showed that polymorphism of genes of proinflammatory cytokines (TNFα, IL-8 and IL-6) is high producing and polymorphism of the gene of anti-inflammatory cytokine IL-10 is low producing. Besides, we noted a clear-cut tendency toward higher incidence of polymorphic alleles of genes of proinflammatory cytokines in Group One patients.

Assessment of current exposure levels in different population groups of the Kola Peninsula.

Activity concentrations of 137Cs and 90Sr in samples of vegetation and natural food products collected in the Kola Peninsula in 1998 and 1999 indicate a very slow decrease in contamination levels during the last decade, mainly due to the physical decay of the radionuclides. The activity concentrations of 137Cs in reindeer meat decreased with a half-life of about 9 years. 137Cs in lichen, moss and fungi is significantly higher than in natural vegetation (grasses) and agricultural plants (potatoes). The activity concentrations of 137Cs in reindeer meat were two orders of magnitude higher than those in locally produced beef and pork. Consumption of reindeer meat, fish, mushrooms and berries constituted the main contribution to the internal dose from 137Cs and 90Sr for reindeer-breeders in the Lovozero area. The estimated committed doses due to 137Cs intake in this group were about 10 microSv per month in summer 1998 and 15 microSv per month in winter, 1999. There was good agreement between internal dose estimates based on intake assessment and whole body measurements. The population of Umba settlement, which is not involved in reindeer breeding, received individual committed doses due to 137Cs intake of about 0.5 microSv per month, about a factor of 20 less than the reindeer-breeders in Lovozero. In this case, the main contribution to the internal dose of the general population came from consumption the of 137Cs in mushrooms and forest berries. The contribution of 90Sr to the internal dose varied from 1% to 5% in the different population groups studied.

[The toxicological characteristics of ammonium glycyrrhizinate (glycyram). A study of its acute and subacute toxicity]. / Toksikologicheskaia kharakteristika glitsirizinata ammoniia (glitsirama). Issledovanie ostroi i podostroi toksichnosti.

A single parenteral and oral administration of ammonium glycyrrhizinate in rat and mice experiments showed that the compound is related to practically nontoxic drugs. Its repeated administration (30 times) into the stomach in a maximum daily therapeutic dose (7 mg/kg) and in a four-fold dose (28 mg/kg) did not cause signs of intoxication, essential changes in the hematological and integral parameters, shifts in the activity of serum enzymes, morphological changes in the cell structures of the internal organs. Administration of the drug in a dose of 28 mg/kg for a second time led to changes in the activity of some enzymes in the brain, the development of parenchymatous dystrophy of the liver which changed to acidophilic necrosis attended with signs of regeneration. Under conditions of a subacute experiment the maximum daily therapeutic dose of ammonium glycyrrhizinate may be considered practically nontoxic.

[Experimental research on the chronic inhalational toxicity of chloracetophon]. / Eksperimentalni prouchvaniia vurkhu khronichnata inkhalatorna toksichnost na khloratsetofona.

The chronic inhalational toxicity of chloracetophon was studied on 24 albino Wistar rats, with concentrations 20 mg X m-3. The animal were exposed 4 hours/daily, 5 days/weekly, for 90 days. Integral, biochemical, histological and electron-microscopic methods were used for the evaluation of the toxic effect of the preparation. The results reveal metabolic and structural alterations in the organs studied, better manifested in liver as compared with the lungs. A provisional MAC for chloracetophon is proposed on the base of the complex study carried out, being 0.1 mg X m-3.

[Biological activity of Bulgarian zeolite rocks]. / Biologichna aktivnost na bulgarski zeolitni skali.

An evaluation of the biological activity of Bulgarian zeolite rocks was made by the methods in vivo and in vitro. The results pointed out to specific biological effect--cytotoxic and fibrogenic--most strongly expressed for clinoptilolite followed by mordenite and erionite. The clinoptilolite is characterized by strong cytotoxic effect in comparison with dust of calibrated quartz DQ-12 which confirms the lack of correlation between cytotoxicity and fibrogenicity for some types of dust. On the basis of the results a temporary hygienic norm for clinoptilolite dust--2 mg/m3 is proposed.

[Occupational risk after repeated skin exposure to styrene]. / Profesionalen risk pri mnogokraten dermalen kontakt sus stirol.

The use of styrene in the production and processing of polymers, varnishes and paints is a prerequisite for a broad skin contact with the solvent, hence conditions for occupational effect on the workers, manifested with frequent contact toxic dermatitis. That determined the scope of this work, aiming at the specifying of the occupational risk in case of repeated dermal contact with styrene. The experiment was carried out in the course of 28 days on 70 albino male rats, treated daily, dermally with 4 ml/kg and 8 ml/kg from the substance and on groups with a following 14--day rehabilitation. The following methods were used in the investigation: histological (H.E.), histochemical (Sudan III, Sudan schwartz and PAS-reactions under the control of alpha-amilase), enzyme-histochemical (activity of alkaline phosphatase, acid phosphatases, ATP, SDH, LDH and G16PDH) and electron microscopic. The repeated skin application of styrene was established to induce changes in the organism of the experimental animals, localized mainly in the liver and carrying the character of fatty dystrophia. The latter is directly proportional to the dose applied and the exposure duration. After a 14-day rehabilitation period, the dystrophia abates and the processes of proliferation and regeneration predominate in the organ, regardless of the enzyme disorders established in the oxidation-reduction processes of liver, with the higher styrene dose (8 ml/kg). The authors presume that the dynamic follow up of the adaptation mechanisms in liver, in case of repeated dermal contact with styrene, determines reversible tissue deviations in organism of the experimental animals, being dose-effect dependent. The authors are in the opinion that the occupational risk in production and processing of polystyrene is minimum when observing the sanitary instructions for safe contact.

[Histochemical mechanisms in etiology of pulmonary fibrosis after short-term exposure to a mixture of dust and quartz from copper mine]. / Otnosno niakoi khistokhimichni mekhanizmi v protsesa na belodrobnata fibroza pri kratkotraino vyzdeistvie na smeseni prakhove i kvarts ot mednorudni nakhodishcha.

The authors induced pulmonary silicosis in albino rats by the intratracheal method with 50 mg mixed middling slime from Panaguiriste and quartz dust, dissolved in I ml physiological solution. The animals received a single treatment and were killed on 90th day of the experiment. Some intime characteristics of collagen-forming mechanisms in lungs were followed up via routine histological, histochemical, enzymohistochemical/ acid phosphatase activity, beta-glucoronidase, AS-esterase and lipase/ and autoradiographic/H3 labelled proline/ methods. It was established, that under the effect of both dusts from Panaguiriste mines studied/ mixed dust and pure quartz dust/ considerable deviations developed in the structure of the lungs of the experimental animals in the enzyme activity of acid phosphatase and carbon esterase, accompanied by various forms of fibrosis in the organ, depending on the dust applied. The difference in the composition of both dusts quartz and mixed dust slime - had an effect on the degree of the deviations, but not on their character, manifested in: I. specific protective reaction of organism, with activation of the ferments from the group of carbon esterase in macrophagic elements of interstitium and around the silicotic alterations in the lungs of the experimental animals; 2. inhibition of the maturation of macrophages in silicotic foci and 3. acceleration of the proliferation of fibroblasts with intensification of collagen-formation, accompanied by an enhanced activity of the ferments from the group of carbon esterase and in the cytoplasm of fibroblasts. The authors draw the conclusion that the complex use of routine histological, histochemical and quantitative isotope methods enables the more significant determination of fibrinogenicity of quartz-containing dust even at the early terms of their exposure under experimental conditions.

[Biorhythm changes in DNA synthesis in hepatocytes exposed to organophosphates and strontium-89]. / Promeni v bioritmite na DNK-sinteza v khepatotsita pod vuzdeistvie na FOS i strontsii-89.

The authors irradiated albino rats with I microc/gr strontium89 with previously modelled liver injury by FOS (Agria 1050). A temporary inhibition of the methodical activity was established as well as aberrant mitoses and strongly manifested polyploidity of the hepatic cells. Those phenomena faded quickly (within 8 days), with the exception of polyploidity, which as a sign of physiological regeneration the authors admit to be adaptive reaction directed to the restoration of the functional level of the liver on account of the hepatocytes preserved. Prior to the onset of tissue regeneration, the cellular one should be terminated, due to which, the mytotic activity was highly inhibited on the 3rd day of the irradiation, the DNA-synthesis cycle being lengthened and mainly on account of tgi, i.e. during the reparative biosynthesis the cell is incapable/of developing in the mitotic phase. After the presynthetic period is over the hepatocytes rapidly overcome the inhibition, tgi is considerably shortened and from presynthesis they almost immediately enter the period of mitosis. That requires an additional protein synthesis, manifested by the changes in serum protein. S and G1 proved to be most sensitive to DNA-synthesis blocking. The presynthetic period is essentially lengthened due to lesions of the cellular structures, synthesizing substances, necessary for entering S - i.e. the hepatocytes pass T, equal to the inhibition between G1 and S, its duration being proportional to the degree of the lesion of the organ.

[Comparative study of the intermittent and continuous action of the herbicide, Ramrod]. / Sravnitelno izsledvane na intermitentnoto i monotonnoto deistvie na kherbitsid ramrod.

Repeated oral toxicity was assayed in albino rats of either sex, receiving every day 70 mg/kg of Ramrod for 4 months (group I) and everyday, but on alternate weeks-140 mg/kg (group II). A third experimental group of animals received daily 70 mg/kg of Ramrod on alternate weeks for 8 months. In comparison with the respective pure control groups of rats, those receiving monotonous treatment has the most liver function changes. Both intermittent schedules induced a phasic pattern in the adjustment processes: the response to intermittent administration of 70 mg/kg Ramrod was that of physiologic compensation. Periodic application of the herbicide for plant protection should be preferred, in view of prevention from progessional poisoning.

[Pathologicoanatomic and enzymatic histochemical changes in the body of white rats with chronic, intermittent pirimor pesticide poisoning]. / Pathologoanatomichni i enzimokhistokhimichni promeni v organizma na beli plukhove pri khronichna intermitirashta intoksikatsiia s pestitsida pirimor.

Not infrequently, the continuous use of pesticides leads to production of resistant species of agricultural pests which makes imperative to adopt the practice of intermittent, i. e. periodic application of the agricultural preparations. In this work the difference in degree of pathoanatomical damage upon chronic and periodic, weekly application of the new carbamide pesticide Pyrimor, extensively used in the Bulgarian farming economy, is discussed. The results of pathomorphological and histochemical study of the chief parenchymatous organs shows a clearcut difference in the group with continuous administration of the pesticide, as compared to the control and intermittently poisoned group. It is furthermore pointed out that the two-times higher dose, introduced at weekly intervals, leads to slighter lesions of parenchymatous organs in comparison with chronic, oral Pyrimor treatment. Season related, incessant use of pesticides results in occupational risk increase among the workers engaged in farming.

DNA synthesis and some morphometric changes in the liver during different regiments of nutrition.

Male albino rats were fed for 20 and 140 d on full value (standard pellet), or defective diet (60% of the quantity given to the previous groups). Besides, half of the animals were left to swim daily up to 70 min. Histoautoradiographic and morphometric results point to changes in nuclear classes, the percentage of marked mitoses, the DNA content of the nuclei and the number of binuclear hepatocytes. It is assumed that the physical loading serves as starting mechanism and stimulator to the proliferative activity of the cells; that the defective diet leads to a decrease of the cell nuclei; that the quantity of the enlarged nuclei varies according to the stage of DNA synthesis etc. In general, the data revealed, point to the trend of the regenerative processes occuring in the liver of rats on defective diet and physical strain.