Formation of DNA adducts in tissues of mouse progeny through transplacental contamination and/or lactation after administration of a single dose of ochratoxin A to the pregnant mother.

Ochratoxin A (OTA) is a mycotoxin which has been detected in foods of plant origin, in edible animal tissues, and in human sera, urine, and milk in many countries. OTA is nephrotoxic and carcinogenic in mice and rats and is suspected to play a key role in the etiology of Balkan endemic nephropathy and/or associated urinary tract tumors. In the present study, some early signs of genetic impairment, including the presence of DNA adducts in target tissues from the progeny of mice after administration of a single OTA dose during late pregnancy, have been investigated.

Dominant-lethal mutations and micronucleus induction in male BALB/c, BDF1 and H mice by tobacco smoke.

The mutagenicity of whole tobacco smoke (TS) was examined in male BALB/c, BDF1 and H mice using the dominant lethal and micronucleus tests in bone marrow polychromatic erythrocytes. Male mice (about 80 days old) from the three strains were treated with TS on 5 days/week for 8 weeks. The animals were divided into three groups for every strain: control and two experimental groups.

[The testing for carcinogenicity of a polyethylene terephthalate vascular prosthesis].

A long-term for possible carcinogenicity was conducted by subcutaneous implantation of 1 cm 2 pieces of polyethylenetherophthalate vascular grafts (PET-VG) to 150 BDF1 mice and 120 Syrian golden hamsters of either sex. A false operation was carried out in the same number of animals of control groups. Implantation was performed in nine-week-old animals.

LDH isozymes in transplantable hamster tumours with different histogenesis and differentiation.

LDH isozymes were assayed by polyacrylamide gel electrophoresis in 6 long-term transplantable skin tumours in Syrian hamsters. The percentages of the M-subunits were as follows: in a slow growing fibrosarcoma with abortive differentiation and producing lung metastases -- 63.3; in two well differentiated squamous cell carcinomas with moderate growth -- 79.

LDH isoenzymes in cell cultures from transplantable hamster tumors with dissimilar histogenesis and differentiation.

LDH isoenzymes were assayed by acrylamide disc electrophoresis in the following material: (a) cells from 4 transplantable hamster tumors; (b) cells from the same tumors cultured for 0, 4, 12 or 24 h as well as for 3, 7, 12 or 26 days; (c) tumors obtained after re-inoculation of cells cultured for 26 days. During the first days of culture, the cells retained LDH patterns similar to those of tumors in vivo. Then a progressive increase in the M/H ratio was observed in all cultures.

In vivo inhibition of the tyrosinase of hamster melanoma with sodium diethyldithiocarbamate.

In vivo inhibition of the DOPA-oxydase activity of the soluble tyrosinase fraction of melanotic hamster melanoma is found after i.p. administration of diethyldithiocarbamate, with considerable increase in the content of SH-groups which probably play the role of free radical scavengers.

Partial hepatectomy and liver regeneration in Syrian hamsters.

In Syrian hamsters 74-75% removal of the liver led to 8-10% mortality. Cell mitosis increased at 36-42 hours after the operation and reached a peak of 43-51% during the 3rd day. Individual variations in liver weight as well as in number of mitosis were smaller in 2-3 months old hamsters than in 6-12 months old animals.

[Malignant tumors in a region of endemic nephropathy].

In villages with endemic nephropathy (EN) high incidence and mortality rates of some urinary system tumors are reported. Age-adjusted incidences of renal pelvic and ureteral neoplasms were 46/10(5) in females and 27/10(5) in males; for urinary bladder tumors these figures were 16/10(5) and 35/10(5). The frequency of parenchymal kidney tumors was similar to that reported for the country as a whole.

Geographic correlation between the occurrence of endemic nephropathy and urinary tract tumours in vratza district, Bulgaria.

Data on the occurrence of endemic nephropathy (EN) and urinary tract and other cancers in an endemic region of Vratza district, Bulgaria, for the years 1965-1974, are presented. In endemic villages a high incidence of urinary tract tumours, affecting in particular the renal pelvis and ureter, closely correlated with the EN incidence and mortality rates. In the villages with high and moderate EN incidences urinary tract tumours are the most common neoplasms.