[The biochemical indices of the blood serum in experimental hepatitis A in tamarins]. / Biokhimicheskie pokazateli syvorotki krovi pri éksperiemental'nom gepatite A u tamarinov.

Serum biochemical parameters were studied in 42 healthy wild-caught adult tamarins (S. mystax), males and females, to determine the normal values. Blood samples were drawn repeatedly, and the serum was tested for aspartate aminotransferase, alanine aminotransferase, isocitric dehydrogenase, serum glucose, serum urea, triglyceride, cholesterol, albumin, and total protein. The results indicated that serum chemistry values were similar to those reported as normal for both humans and other Callitrichidae species. The study of serum biochemical parameters in tamarins with experimental hepatitis A indicated that serum enzyme activities alone reflected the hepatic damage, while other biochemical parameters were of no real clinical importance. The experimental results showed the levels of serum urea to be indicative of the pathological involvement of the kidneys in experimental hepatitis A in some cases.

[The immunogenicity of a cultured inactivated hepatitis A vaccine]. / Immunogennost' kul'tural'noi inaktivirovannoi vaktsiny gepatita A.

A trial of inactivated hepatitis A viral vaccine of heteroploid cell culture origin is described. The vaccine preparation was tested in guinea pigs and tamarins. The animals were immunized intramuscularly four or three times, respectively. The efficacy was judged by induction of anti-HAV antibody persisting for at least 12 months in guinea pigs, and development of immunity to subsequent virus challenge (monkeys only). The challenge dose of HAV was unable to produce any signs of HAV infection in the vaccinated tamarins, although the booster effect was observed in some animals. The study demonstrated that the tested batches of the vaccine were highly immunogenic.

[The modelling of hepatitis A and of enterally transmitted non-A, non-B hepatitis (hepatitis E) in Saguinus mystax tamarins]. / Modelirovanie gepatita A i énteral'no peredaiushchegosia gepatita ni A, ni B (gepatita E) na tamarinakh Saguinus mystax.

A comparative study of hepatitis infection caused by human hepatitis A virus (MS-1 strain), simian hepatitis A virus (AGM-27 strain), and enterically transmitted non-A, non-B hepatitis virus (Tashkent-1435 strain) was carried out. Susceptibility of tamarins to the AGM-27 and Tashkent-1435 as well as to MS-1 strain was demonstrated. All the strains induced an acute infection characterized by serum alanine aminotransferase (ALT) elevation, virus excretion and antibody response. Certain differences in the course of infection caused by these strains were observed in the duration of the incubation period and ALT profiles.

[A trial of a cultured inactivated vaccine against hepatitis A on Saguinus mystax tamarins]. / Ispytanie na tamarinakh Saguinus mystax kul'tural'noi inaktivirovannoi vaktsiny protiv gepatita A.

An experimental batch of inactivated hepatitis A vaccine was prepared using hepatitis A virus (HAV), HAS-15 strain, adapted to cell culture and purified by ultracentrifugation. The vaccine was tested in tamarins immunized intramuscularly three times one month apart. Three tamarins received a vaccine preparation containing 10 ng of immunogen each, three--100 ng each, and three animals were used as controls. The efficacy was judged by the anti-HAV antibody response in the vaccinated animals and development of immunity to subsequent virus challenge two months after the last immunization. The criteria of infection were: elevation of serum alanine aminotransferase, fecal excretion of HAV and production of specific antibody of IgM class. The immune response to 10 ng of the immunogen was lower than to 100 ng, however, both doses produced complete resistance to infection. The booster effect was observed in animals receiving 10 ng of the immunogen. The vaccine batch under study in the indicated doses was shown to have a good immunogenic potency and protective activity for tamarins.

[Development of an infection in monkeys as a result of their sequential natural and experimental exposure to the hepatitis A virus]. / Razvitie infektsii u obez'ian v rezul'tate posledovatel'nogo estestvennogo i éksperimental'nogo zarazheniia ikh virusom gepatita A.

The development of spontaneous outbreak of hepatitis A (HA) among African green monkeys kept under strict isolation conditions was studied. It was shown that in the case of introduction of HAV the infection involved all the susceptible monkeys, running a course with and without any increase in the level of activity of serum alanine aminotransferase (ALT) After inoculation of commercial gamma-globulin only the infection without the ALT activity increase developed and some monkeys had no signs of HA at all. Experimental reinfection with HAV was produced in monkeys having anti-HAV titres of less than or equal to 1:3500.

[Susceptibility of Macaca rhesus to infection with hepatitis A virus strains isolated from man and monkeys]. / Vospriimchivost' makak rezusov k zarazheniiu shtammami virusa gepatita A, vydelennymi ot cheloveka i obez'iany.

The results of infection of Macaca rhesus monkeys with hepatitis A virus (HAV) strains isolated from monkeys and man are presented. After inoculation of monkeys with human NAV strains the infection could not be reproduced whereas simian HAV strains were found to be pathogenic for M. rhesus monkeys both on experimental inoculation and during natural contacts with infected monkeys in the animal house.

[Endocrine function of the ovaries of blue foxes (Alopex ladopus) during postnatal ontogenesis]. / Endokrinnaia funktsiia iaichnikov golubykh pestsov (Alopex ladopus) v postnatal'nom ontogeneze.

Progesterone, androgen and estradiol levels in the blood plasma were radioimmunologically studied in female Alopex lagopus aged 2 to 9 months with different weight at birth. The blood sex steroid level showed a sharp elevation at the age of 4 months. The weight gain stops by this time. Thus, by the age of 4 months in females the sexual system becomes mature. From the age of 5 to 8 months there is a fall of the blood sex hormones, corresponding to anestrus, and by the age of 9 months there is a significant rise in the level of sex hormones pointing to activation of the ovarian function by the reproductive season. Large females had a tendency to earlier sexual maturation in comparison with the small ones. Since in the female animals of the species under study two peaks of sexual hormone concentration were revealed in the course of a year it is suggested that at the preceding evolutional stages representatives of the family were capable of reproducing twice a year.