Epidemiologic and etiologic characteristic of enterovirus infections in Khabarovsk region

Results of epidemiologic, virologic, and serologic studies of enterovirus infections in Khabarovsk region from 1975 to 2006 were analyzed. Patterns of epidemic process of these infections were established: periodic change of dominating type of pathogen in the population; onset of the large epidemic peaks of incidence during emergence of circulation of new for the given area serotypes of enteroviruses; possibility of realization of several routes of virus transmission. Role of water factor in the progress of the epidemic process was revealed. Etiology of the large epidemic rise of aseptic meningitis incidence in Khabarovsk region in 2006 was established--the leading pathogens were ECHO viruses serotypes E6 and E30.     

Influence of photoperiod on development and maturation of <Emphasis Type="Italic">Macrolophus pygmaeus</Emphasis> (Hemiptera,Miridae)

The effects of day length on development and reproductive maturation of zoophytophagous bug Macrolophus pygmaeus (= M. nubilis) were investigated under laboratory conditions using two strains originated from the environs of Rome, Italy (41.75°N, 12.30°E and 41.95°N., 12.80°E) and Sochi, Krasnodar Territory, Russia (43.9°N, 39.3°E). The insects were kept under day length of either 10 or 16 h at a constant temperature of 20°C. Nymphs and adults were fed on the grain moth eggs. Embryonic development lasted 18–20 days, nymphal development, 25–30 days, and reproductive maturation of females, 4–6 days. The short day length (10 h) resulted in 1–2-day prolongation of nymphal development and a longer maturation time in individuals from both strains, whereas the duration of embryo development was independent of photoperiod. Under both photoperiods, males developed faster than females. Under the short day length, females of the Rome strain matured markedly faster than those of the Sochi strain. Faster development under low temperature and stronger tendency to delay the reproductive maturation observed in the Sochi strain could be explained by a relatively fast (when compared with Rome) autumnal decrease in temperature. The mechanism and adaptive value of the long-day acceleration of development are not yet clear.     

Alu DNA polymorphism in ACE gene is protective for age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. We report an association between an Alu polymorphism in the angiotensin-converting enzyme (ACE) gene with the dry/atrophic form of AMD. Using the polymerase chain reaction (PCR) on genomic DNA isolated from patients with AMD (n=173), and an age-matched control population (n=189), we amplified a region polymorphic for an Alu element insertion in the ACE gene. The Alu(+/+) genotype occurred 4.5 times more frequently in the control population than the dry/atrophic AMD patient population, (p=0.004). The predominance of the Alu(+/+) genotype within the unaffected control group represents a protective insertion with respect to the human ocular disease, dry/atrophic AMD. This is the first demonstration of an Alu element insertion exerting protective effects against a known human disease.     

Succinate dehydrogenase activity in rat kidney after repeated administrations of p-aminohippurate or sodium chloride

During PAH excretion and 18 h after repeated PAH administrations to rats, renal cortical SDH activity was unchanged in comparison with untreated controls. On the other hand, 18 h after repeated administrations of 0.9% or 1.8% NaCl solution, SDH activity was decreased by about 20% in kidney cortex. In outer medulla SDH activity was decreased 18 h after all pretreatments. The decline of SDH activity was observed whenever an increased urinary Na excretion occurred, except that PAH was repeatedly administered. The probability is discussed that substrate-induced stimulation of the carrier system for weak organic acids is accompanied by an increase of mitochondrial activity in kidney cortex.     

Adverse effects of tempol on hidrosaline balance in rats with acute sodium overload

We studied the effects of tempol, an oxygen radical scavenger, on hydrosaline balance in rats with acute sodium overload. Male rats with free access to water were injected with isotonic (control group) or hypertonic saline solution (0.80 mol/l NaCl) either alone (Na group) or with tempol (Na-T group). Hydrosaline balance was determined during a 90 min experimental period. Protein expressions of aquaporin 1 (AQP1), aquaporin 2 (AQP2), angiotensin II (Ang II) and endothelial nitric oxide synthase (eNOS) were measured in renal tissue. Water intake, creatinine clearance, diuresis and natriuresis increased in the Na group. Under conditions of sodium overload, tempol increased plasma sodium and protein levels and increased diuresis, natriuresis and sodium excretion. Tempol also decreased water intake without affecting creatinine clearance. AQP1 and eNOS were increased and Ang II decreased in the renal cortex of the Na group, whereas AQP2 was increased in the renal medulla. Nonglycosylated AQP1 and eNOS were increased further in the renal cortex of the Na-T group, whereas AQP2 was decreased in the renal medulla and was localized mainly in the cell membrane. Moreover, p47-phox immunostaining was increased in the hypothalamus of Na group, and this increase was prevented by tempol. Our findings suggest that tempol causes hypernatremia after acute sodium overload by inhibiting the thirst mechanism and facilitating diuresis, despite increasing renal eNOS expression and natriuresis.     

Etiology, clinical manifestations, and epidemiology in community-acquired respiratory infection in children in the Khabarovsk region

Clinico-epidemiological analysis and etiological verification of the outbreak of respiratory infection among school children in a rural district of the Khabarovsk territory, registered in spring 1997, were made. According to clinical signs, one-third of the patients had whooping cough, while the rest of the children exhibited the signs of respiratory infection with the symptoms of longering bronchitis. A half of the children had not been vaccinated against whooping cough, as they had been given injections of adsorbed DT vaccine with reduced antigen content. Etiologically, the diagnosis of whooping cough was confirmed in 57% of the patients with 47.4% of them having Bordetella pertussis monoinfection and 52.6% having mixed infection, mainly in combination with chlamydiosis. Whooping cough took an abnormal course under these circumstances. Treatment with erythromycin produced a good effect.     

Heat shock influences on parasitization of the Angoumois grain moth Sitotroga cerealella Oliv. (Lepidoptera, Gelechiidae) eggs by the egg parasitoid Trichogramma principium Sug. et Sor. (Hymenoptera, Trichogrammatidae) females

Experiments have showed that heat shock (45°C during 30 min) caused a twofold increase in mortality of T. principium females recorded during two days after the shock. The percentage of females that have started parasitization of the grain moth eggs (among all survived females) sharply decreased (40–50% and 30% in controls and in treated females, respectively). Thus, the switch from egg retention to parasitization of less preferred hosts was not the result of “pathological” changes in a senescent or dying wasp, but a “normal” stage of adult life. Females that have already started parasitization before the heat shock, continued to parasitize after the shock (differences between treatments and controls were not significant). Obviously, the heat shock influence on oviposition was mostly indirect (as a cue factor) and the wasps that have already started parasitization, were insensitive to this cue. These data resemble the loss of sensitivity to the diapause-inducing factor which was often observed after reactivation. We conclude that the results of our study confirm analogies between egg retention and reproductive diapause.