WEST NILE FEVER IN THE SARATOV REGION IN 2013-2015.

West Nile virus (WNV) circulation in the territory of Saratov region and its role in the infectious pathology were investigated. For this purpose, in studies conducted in 2013-2015, suspensions of bloodsucking arthropods, organs of birds and small mammals were analyzed for the presence of WNV markers (antigens and/or RNA). The seroprevalence level in live-stock animals and population of the region was evaluated; clinical samples from patients with symptoms compatible with West Nile fever (WNF) were analyzed. As a result of the investigations, WNV markers were detected in field samples gathered in natural biotopes and in the city of Saratov. Immunity to WNV was detected in horses. A stable domain of persons with immunity to this agent was revealed among regional population. Patients with WNF have been annually registered in the region since 2012. The obtained results confirm active circulation of WNF in the Saratov region, as well as formation of stable natural and anthropourgic foci.

Measurement and modelling the sensitivity of tetrapolar transfer impedance measurements.

Finite element method (FEM) modelling of a small disk in a homogeneous saline medium showed that the sensitivity distribution for tetrapolar transfer impedance measurements was dependant on the ratio, σdisk/σsaline, and not absolute conductivity values. In addition, the amplitude of the negative sensitivity regions between the drive and receive electrodes decreased non-linearly with σdisk/σsaline for σdisk/σsaline < 1, eventually becoming zero. This non-linear behaviour determined the limit of the assumption of a small change in conductivity in Geselowitz's lead theorem with 0.5 <σdisk/σsaline <1.5 for the measurements reported. The modelling supported the design of a sensitivity measurement system using an insulating support and a metal disk in a saline filled tank. Measurements were shown to give good agreement with sensitivity predictions from Geselowitz's lead theorem. Replacing the homogeneous medium in the FEM model with layers of different conductivity parallel to the plane of the electrodes changed the sensitivity distribution when the thickness of the layers adjacent to the electrodes were less than ½ the electrode spacing. A layer of greater conductivity over a layer of lesser conductivity next to the electrodes gave a peak in the sensitivity distribution and extended regions of negative sensitivity further into the tissue.

Synthesis and in vitro study of the anticancer activity of new analogs of octreotide.

Based on the structure of Octreotide (SMS 201-995) some modified at positions 5 with Dap (diaminopropanoic acid), Dab (diaminobutanoic acid) and Orn new C-amide analogs were synthesized. The Thr6 was replaced by unnatural amino acids Tle (t-leucine). The cytotoxic effects of the novel compounds were tested in vitro against a panel of human tumor cell lines. All investigated compounds exhibited different concentration-dependent antiproliferative effects against the HT-29, MDA-MB-231, HepG2 and HeLa cell lines after 24 h treatment. The compound 2 (D-Phe-c(Cys-Phe-D-Trp- Dap-Tle-Cys)-Thr-NH2) had antiproliferative effects on MDA-MB-231 cells with the IC50 0.03 mM. The HeLa and HepG-2 cells were most sensitive towards tested compounds at various concentrations. Results demonstrated that the peptide analogs 3 (D-Phe-c(Cys-Phe-D-Trp-Lys-Tle-Cys)-Thr-NH2), 4 (D-Phe-c(Cys-Phe-D-Trp-Orn-Tle-Cys)-Thr-NH2) and 5 (RC-102) exert the most pronounced inhibition of the cell vitality up to 77% at higher concentrations and were not toxic to the normal Lep-3 cells.

In vitro studies of the activity of newly sinthesized nociceptin / orphanin FQ receptor ligand analogues.

Based on template hexapeptides Ac-Arg-Tyr-Tyr-Arg-Trp-Lys-NH(2) and Ac-Arg-Tyr-Tyr-Arg-Ile-Lys-NH(2) analogues and corresponding deacylated homologues were synthesized substituting ornithine, diaminobutanoic (Dab) and diaminopropanoic (Dap) acids for lysine at position 6. The aim was to investigate the effect of the newly synthesized compounds on the neurogenic contractions of isolated rat vas deferens. Ac-Arg-Tyr-Tyr-Arg-Trp-Lys-NH(2) and its analogues manifested a strong inhibitory effect on the neurogenic contractions without effect on the muscle tone, which is characteristic effect of NOP receptor agonists. In contrast, Ac-Arg-Tyr-Tyr-Arg-Ile-Lys-NH(2) and its analogs manifested a strong inhibitory effect on the muscle tone and negligible effect on the neurogenic contractions which is characteristic effect of NOP receptor antagonists. The most active were the peptides in which Dab or Dap is the substitute. The study reveals that substitution of Lys with shorter amino acids could increase agonist or antagonist activity of the peptide.

Synthesis, cytotoxicity and clastogenicity of novel alpha-aminophosphonic acids.

Alpha-ethyl-N-(phosphonomethyl) glycine is synthesized and characterized by NMR and FAB spectroscopy. The cytotoxicity, clastogenic and antiproliferative effect of 3-ethyl-2-hydroxyl-2-oxo-1,4,2-oxazaphosphorinane, sodium salt of 3-ethyl-2-hydroxyl-2-oxo-1,4,2-oxazaphosphorinane, alpha-ethyl-alpha-N-(hydroxyethylamino) methylphosphonic acid, alpha-ethyl-N-(phosphonomethyl) glycine, alpha-ethyl-N-(phosphonomethyl) glycine isopropylammonium salt, glyphosate isopropylammonium salt are tested.

Synthesis and beta-lactamase inhibitory activity of new 6beta-cysteinesulfonamidopenicillanic acids.

New 6beta-cysteinesulfonamidopenicillanic acids and their sulfoxides were synthesized by sulfonylation of 6beta-aminopenicillanic acid or its (S)-sulfoxide with (R)-N-benzyloxycarbonylcysteinesulfonyl chloride ethyl ester (2a, 1b) and (R)-N-benzyloxycarbonylcysteinesulfonyl chloride benzyl ester (2a, 2b). The corresponding 6beta-cysteinesulfonamidopenicillanic acids sulfones 1c and 2c were prepared by oxidation of the sulfoxides 1b and 2b with potassium permanganate in aqueous medium. When combined with ampicillin some of the compounds reduced the minimal inhibitory concentrations of ampicillin against beta-lactamase producing strains.

Influence of protein calorie malnutrition and fasting on the activities of delta-aminolevulinic acid dehydratase and porphobilinogen deaminase in rats.

Rats were fed a restricted standard diet (6-8 g daily) for 4 weeks. The erythrocyte activity of delta-aminolevulinic acid dehydratase showed a very expressed decrease (7.9 times) and its hepatic activity diminished more than twice. Porphobilinogen deaminase activity was reduced by 40% and 17% respectively. After a 3-day total food deprivation delta-aminolevulinic acid dehydratase activity remained unchanged in red blood cells, but an increase by 52% was found in the liver. The erythrocyte activity of porphobilinogen deaminase was reduced by 42% and its hepatic activity--by 16%.

[Evaluation of initial results of treatment of lead poisoning with EDTA]. / Valutazione dei primi risultati della terapia del saturnismo con EDTA.

The results of EDTA therapy were studied in 37 workers of a battery factory consisting of males with varying degrees of occupational lead poisoning (low exposure: 10 subjects, blood lead levels (PbB) lower than 400 micrograms/l with slight alterations in heme biosynthesis; beyond limit of effect: 5 subjects, PbB > 400 micrograms/l; slight intoxication: 19 subjects, with marked alterations in heme synthesis and preclinical signs of intoxication; average degree of intoxication: 3 subjects with clinical signs of intoxication. Clinical symptoms and the following parameters were investigated: blood lead (PbB), delta-aminolevulinic acid dehydratase in erythrocytes (ALA-D), zinc protoporphyrin (PP) in erythrocytes and delta-aminolevulinic acid (ALA) in 24-hour urine before and after EDTA chelating therapy. Simultaneous measurement of ALA-D and PP showed high diagnostic sensitivity in detecting lead poisoning in occupationally exposed subjects. In view of the high interindividual variability of the results, these indices did not, however, permit a useful differentiation to be made of the different degrees of intoxication at individual level, even though a good correlation was observed between PbB and porphyrin metabolism indices. From the alterations observed in ALA-D and PP values it was not possible to establish an association between degree of alteration and types of clinical symptoms in the different intoxication studies. At the end of EDTA treatment, a clinical improvement was observed in all cases studied but only in 5 cases was a reduction in PbB observed, to levels below 1.20 mol/l, which is accepted as a permissible limit for the general population; in 17 cases PbB remained at levels above the critical value for occupational lead poisoning (400 micrograms/l), although there was a decrease after treatment. The improvement observed in the indices of porphyrin metabolism at the end of treatment was only slight: significant variations were measured only for PbB. After treatment no association was observed between ALA-D and PP variations in erythrocytes and improvement in clinical symptoms; measurement of these indices therefore seems to be of little use in assessing the efficacy of the treatment. In spite of its limited diagnostic sensitivity during intoxication, measurement of ALA in urine could be useful to assess the efficacy of chelating therapy in subjects in whom the values are initially altered.

Porphyria cutanea tarda and peptic ulcer.

A high incidence of peptic ulcer was found in a retrospective study of 199 Bulgarians with porphyria cutanea tarda. Ulcers were found in 35 patients (17.59%), while its incidence in Bulgaria varies between 2.52 and 3.7%. The site of the ulcer was duodenal in 29 porphyriacs, gastric in three, both duodenal and gastric in two and pyloric in one. The pattern of localization was similar to that seen in the general population. Peptic ulcers became symptomatic before the appearance of porphyria in 30 cases. Six (17.1%) of the patients had perforations, while the frequency of this complication in the general population was 1.7-8.5%. Two porphyriacs with perforations died of peritonitis. Ulcers were found in 21 (24.4%) of 86 patients with normal activity of erythrocyte uroporphyrinogen decarboxylase, i.e. they had sporadic (acquired) porphyria cutanea tarda. Two (10%) of 20 patients suffering from the familial form of the disease (with low erythrocyte uroporphyrinogen decarboxylase activity) had ulcers. The examination of 105 unselected porphyriacs showed a significantly higher incidence of blood group B in comparison with the general population (23.8% vs. 16.6%). The association between the porphyriacs with ulcers and blood group B (8 of 21 examined persons) and the rare occurrence of group O (only 4 of 21) was unexpected. An association between porphyria and some of the haptoglobin types could not be established in 98 unselected patients (including those with and without ulcer). More studies are needed to substantiate the validity of blood groups and uroporphyrinogen decarboxylase as genetic markers for porphyria cutanea tarda combined with peptic ulcer.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibitory action of extracts of Maclura aurantiaca and Epilobium hirsutum on tumour models in mice.

Primary screening of alcohol extracts of fruits of Maclura aurantiaca (Moraceae) and the overground part of Epilobium hirsutum (Onagraceae) was conducted in order to test the anti-tumour action on models in mice. Applied in doses of 100 mg/kg and 90 mg/kg, Maclura extract increased the life span of the mice by 158 and 152% accordingly in leucosis P-388 and ascitic tumour of Ehrich. In doses of 1 mg/kg and 3 mg/kg the Epilobium extract prolonged the life span of the mice by 156 and 158% accordingly in leucosis P-388 and ascitic tumour of Ehrlich.

Biochemical changes in alpha-naphthyl isothiocyanate-induced chronic cholangitis in the rat.

Male Wistar rats were treated for 3 weeks with alpha-naphthyl isothiocyanate (ANIT, 5.4 mmol per kg food). Chronic necrotic cholangitis without pronounced transaminasemia and hyperbilirubinemia developed. The activity of 5'-nucleotidase in liver plasma membrane preparations was strongly depressed (3.5 times) while the activities of K+-, Na+- and Mg++-ATPases were not affected. The liver microsomal cytochrome P-450 and cytochrome b5 contents decreased. Elevation of reduced glutathione liver content after challenge with ANIT was recorded. The observed biochemical changes may be important for the pathogenesis of ANIT-induced chronic cholangitis.

Biochemical changes in the rat after chronic thioacetamide intoxication.

Male Wistar rats were given drinking water ad libitum with 0.075% thioacetamide (TAA) for 4 weeks. TAA treatment did not affect serum aminotransferase activities and total bilirubin content. The activities of 5'-nucleotidase, K+, Na+- and Mg2+-adenosine triphosphatases in liver plasma membrane preparations were strongly depressed, while that of gamma-glutamyl transferase was considerably increased. A decline in liver microsomal cytochrome P-450 and cytochrome b5 concentrations was also recorded. In contrast, the content of reduced glutathione in liver homogenate supernatant (9000 g) increased about 2-fold. As plasma membrane associated enzymes seem to be exclusively affected, the liver plasma membrane could be involved in the pathogenesis of the TAA-induced precirrhotic liver changes.

Interaction between glucose diet and ethanol on rat liver microsomal induction and liver plasma membrane damage in chronic hexachlorobenzene intoxication.

Male Wistar rats fed for 60 days a glucose diet containing 17.5 mmol hexachlorobenzene/kg show a less pronounced increase in serum parameters and microsomal cytochrome P-450 concentration and a lower decrease in liver plasma membrane 5'-nucleotidase, K+, Na+- and Mg++-adenosine triphosphatase activities than the controls fed standard diet + hexachlorobenzene. Addition of 10% ethanol to the drinking water eliminates the "glucose effect". The glucose diet and ethanol exert contrasting effects on microsomal enzyme induction and liver plasma membrane damage in hexachlorobenzene intoxication.

Rat liver plasma membrane damage in hexachlorobenzene intoxication and its potentiation by ethanol.

Chronic feeding of male Wistar rats with food containing hexachlorobenzene (HCB) at 17.5 mmol/kg induced elevation of serum amino-transferases and bilirubin content, increase of microsomal cytochrome P-450 concentration, and decrease of 5'-nucleotidase, K+,Na+- and Mg2+-adenosine triphosphatase activities in liver plasma membrane preparations. These changes were potentiated by ethanol consumption suggesting a possible role of liver plasma membrane damage in the pathogenesis of HCB intoxication.

The effect of thioacetamide on rat liver plasma membrane enzymes and its potentiation by fasting.

Thioacetamide, given intraperitoneally (1.4 mmol/kg body mass) to male Wistar rats 24 h before sacrifice promoted a marked elevation of serum aminotransferases, loss of microsomal cytochrome P-450 content and a significant reduction (about 50%) of the liver plasma membrane enzymatic activities (5'-nucleotidase; K+, Na+- and Mg2+-adenosine triphosphatases; and gamma-glutamyl transferase). Previous starvation for 48 h, immediately prior to thioacetamide administration, strongly potentiated the effects of thioacetamide on the serum, microsomal and liver plasma membrane parameters, while fasting itself did not affect them. The liver plasma membrane damage may be one of the reasons for the cell death in thioacetamide-intoxicated rat livers.