Isolation of Bhanja virus from ticks of the genus Haemaphysalis in southeast Bulgaria and presence of antibodies in pastured sheep.

Bhanja virus was isolated from ticks of the genus Haemaphysalis (H. punctata and H. sulcata) collected from sheep pastured in the surroundings of Akhtopol in southeast Bulgaria, and simultaneously blood sera of 58 sheep were investigated in plaque-reduction neutralization test with B lranja arbovirus.

Virological examination of mosquito larvae from southern Moravia.

254 pools of 4,115 mosquito larvae belonging to nine species were examined by isolation experiments. The larvae were collected in breeding places in an inundated forest--a natural focus of Tahyna virus, in April, June and July 1974 and 1975. Tahyna virus was isolated from one pool of 10 Culiseta annulata larvae collected in July 1974.

[Tubular and glomerular nephropathy induced in rabbits by injection of a heterologous antitubular basement membrane serum].

A nephropathy affecting both tubules and glomeruli has been induced in Rabbits by the injection of an heterologous immune serum directed against Rabbit tubular basement membrane. It differs from experimental antiglomerular basement membrane nephropathy by the fixation of antibodies and C3 on tubular basement membrane and by the occurrence of glucosuria.

[Isolation of structural glycoproteins from human placenta].

Microfibrils about 100 A wide are isolated by mechanical procedures (sieving and ultrasonic disintegration from villosities of human placenta. Amino acid and carbohydrate compositions seem to be related to structural glycoproteins described before in connective tissues.

Synthesis and antitumor activity of 1,2-dihydro-1-(2-deosy-beta-D-erythro-pentofuranosyl)-2-oxo-5-methylpyrazine 4-oxide, a structural analogue of thymidine.

1,2-Dihydro-1-(2-deoxy-beta-D-erythro-pentofuranosyl)-2-oxo-5-methylpyrazine 4-oxide was synthesized by condensation of the silylated pyrazine base with the blocked chloro sugar, followed by removal of the protecting groups. The compound inhibited the growth of leukemia L1210 cells in vitro by 50% at 2 x 10-7 M. At 400 mg/kg/day x 6 it increased the life-span of leukemia L1210 bearing mice by approximately 55%, without apparent toxicity to the host.

[Simultaneous isolation of rabbit glomerular and tubular basement membrane].

A method allowing simultaneous isolation of Rabbit alomerular and tubular basement membranes has been perfected. Rabbit tubular basement membrane has also been obtained by tryptic digestion of the renal cortex. Electron microscopic observation and biochemical analysis show that the contamination of the membrane preparations by cellular components is negligible.

Synthesis and inhibition analysis of 2(4)-imino-4(2)-amino-2,4-dideoxyriboflavin, a dual antagonist of riboflavin and folinic acid.

The synthesis of the 2,4-diamino analogue of riboflavin is described. Inhibition analysis in a microbial assay system indicated that this compound has a weak antifolate activity that could be overcome with a minimal amount of folinic acid, but at higher concentrations both folinic acid and riboflavin were required for the reversal of its inhibitory effect.

Experimental infection of foxes with Tahyna virus.

Three foxes about 18 weeks old were each subcutaneously inoculated with approximately 200 LD50 dose of extraneurally passaged strain of the Tahyna virus "236". Viremia was demonstrated in all animals during the 48-96 hours interval after infection. The maximum value was 1.

Oligonucleotides containing modified bases. I. Inhibition of DNA and RNA polymerases by partially thiolated oligocytidylic acids.

A series of oligomers of cytidylic acid were prepared and partially (6-9% of the bases) thiolated in the 5 positions. The modified oligomers showed increasing inhibition with increasing chain length of both the DNA polymerase-alpha from regenerating rat liver and the DNA-dependent RNA polymerase of E. coli, but the minimum chain length for observable inhibitory activity was 5 nucleotide units for the DNA polymerase-alpha and 16 units for the RNA polymerase.

[The ecology and medical importance of the Tahyna Virus (author's transl)].

In 1958 a virus transmitted by a mosquito was isolated in the Slovakian village of Tahyna. Since this virus was unknown in Europe, a detailed study was begun. It was shown that this virus belonged to the California group of arboviruses and occurs in practically all European countries.

Action of partially thiolated polynucleotides on the DNA polymerase alpha from regenerating rat liver.

The effects of partially thiolated polynucleotides on the DNA polymerase alpha from regenerating rat liver were investigated. The enzyme was isolated from the nuclear fraction essentially according to the method of Baril et al.; it was characterized as the alpha polymerase on the basis of its response to synthetic templates and its inhibition with N-ethylmaleimide.

[Study of the nephrotoxicity of antibodies directed against the glomerular basement membrane glycoproteins of the Wistar rat].

The nephrotoxic activity of prepared antibodies against previously isolated glycoproteic fractions of the Rat glomerular basement membrane was studied using Masugi's model of Nephritis. This activity was determined by following the daily evolution of the proteinuria and the value of the seric complement. It seems linked to numerous factors.

Differential effects of 5-methylmercapto-2'-deoxyuridine on the replication of herpes simplex virus type 1 in two cell systems.

5-Methylmercapto-2'-deoxyuridine (MeMUdR), a structural analogue of thymidine (TdR), inhibits herpes simplex virus type 1 production in mouse L (Lb) cells at concentrations that are not inhibitory to viral growth in monkey kidney (CV-1) cells. It is moderately toxic to Lb cells but not to CV-1 cells at a concentration that causes 95% inhibition of viral replication in Lb cells. MeMUdR is incorporated into cellular and viral deoxyribonucleic acid (DNA) in both systems, but to a significantly higher level (compared with thymidine) in Lb cells.