Spontaneous tumors in rats from the Rappolovo Breeding Nursery of the Academy of Medical Sciences of the USSR]

The authors report the data on the incidence of neoplasms in rats of the "Rappolovo" nursery breeding (USSR Acad. Med. Sci.) and their offsprings during 4 sequential generations kept in the vivarium of the N. N. Petrov Research Institute of Oncology of the USSR Ministry of Health. The frequency of spontaneous tumors in 213 male and 230 female rats was 25.8 and 35.7% accordingly. Totally, male animals developed 65 tumors, females--114. over 80% of all neoplasms developed in animals older than 18 months. The frequency of neoplasms of separate localizations in males and females was as follows: the hypophysis--7.0 and 12.6% correspondingly; the mammary gland--0.5 and 11.7%, the thyroid (thyroidal epithelium) - 1.4 and 3.0% and (light cells) 5.6 and 8.3%; the adrenal cortex--0.5 and 1.3%; the hematopoietic system --7.0 and 5.6%; parasitic sarcomas of the abdominal cavity --5.6 and 3.0%; the skin --0.4 and 0.4%; soft tissues --0.9 and 0%; the liver--0.4 and 0.4%; the kidneys --0.4 and 0.4%. Moreover, one male showed seminal vesicle tumor, and females-solitary neoplasms of the pancreas and salivary gland, the dura mater, the ovary and uterus. Significant differences were revealed in the frequency of spontaneous neoplasms in separate rat generations.     

Characteristics of vestibulo-ocular interaction in healthy adults

Vestibulo-ocular interaction was investigated in 25 healthy subjects, aged 16-48 years. They showed a nearly complete inhibition of the vestibulo-ocular reflex (VOR) during rotation and gaze fixation at a target rotating together with the chair; the reactivity coefficient was no more than 0.05. During rotation with the eyes closed a specific type of the VOR phase shift was detected. These observations on normal subjects can be used for reliable interpretation of vestibulo-ocular interaction in patients with vestibular disorders.     

Characteristics of vestibulo-ocular interactions in patients with unilateral lesions of the peripheral part of the vestibular system. Sinusoidal rotation. 3

In 40 patients with unilateral injury of the peripheral compartment of the vestibular system in the stage of decompensation (Group 1) and subdecompensation (Group 2), the vestibulo-ocular reflex (VOR) was investigated during sinusoidal rotation with the eyes closed. Group 1 patients showed a significant asymmetry of the VOR coefficient and a distinct shift of the VOR displacement towards injury during sinusoidal stimulation of any intensity. Group 2 patients displayed similar but less significant changes.     

Some aspects of treatment of dissecting aneurysm of the aorta

The problem of dissecting aneurysms of the aorta (DAA) is discussed on the basis of an analysis of treatment of 63 patients, a comparison of 19 clinico-morphological findings included. It was found that in elderly and senile patients DAA often developed in its abdominal portion against the background of atheromatous-ulcerous lesions responsible for the "scrappy" dissection and formation of "pockets" in the aorta wall. The formation of distal fenestration with a "double-barrel" was observed much more rarely. For the early diagnosis of the aorta aneurysm dopplerography of the abdominal part of the aorta is recommended in elderly and senile patients with arterial hypertension and symptoms of occlusion in the aorta-femoral segment. The operative treatment of DAA and its long-term results are analyzed. A case of clinical management of dissecting aneurysm of the ascending portion of the aorta developed against the background of congenitial dysplasia of the connective tissue successfully operated in a woman with rheumatism is described.     

The role of cervical proprioceptive afferentation in compensatory mechanisms of vestibular dysfunction. 1. Passive cervico-ocular reflex in unilateral labyrinthine lesion

Passive cervicoocular reflex (PCOR) was studied in patients with unilateral affection of the labyrinth at the stage of decompensation and subcompensation according to the following three criteria: nystagmic direction, reactivity coefficient and phasic deviation. In decompensation of unilateral vestibular dysfunction, PCOR presents intensively and asymmetrically while in subcompensation it becomes symmetric and less intensive. The PCOR is characterized as compensatory in unilateral lesion of peripheral vestibular system.     

Effect of exogenous {beta}-glucuronidase on the carcinogenicity of 1,2-dimethylhydrazine in rats: evidence that carcinogenic intermediates form conjugates and act through their subsequent enzymatic release

Albino, outred 3-month-old rats were given a single s.c. doseof 1,2-dimethyihydrazine dihydrochioride (DMH; 100 mg/kg) and,6 or 24 h later, an i.v. dose of bovine liver ß-glucuronldase(3 x 10⁴ Fishman units). After this treatment, the incidenceof tumours of the large intestine and Zymbal gland, and of cystocholangiomaswas similar to that found in rats treated with DMH alone; theincidence of malignancies in various other tissues was considerablyhigher than that in rats treated only with DMH, especially inanimals exposed to ß-glucuron1dase 24 h after administrationof DMH. ß-Glucuronidase itself had no carcino genicactivity. The broadening of the spectrum of malignant tumoursproduced in DMH-treated rats by administration of ß-glucuronidaseindicates that the carcinogenic effect of DMH may be exertedthrough formation of comparatively stable conjugates of itsmetabolites and their enzymic release in target tissues. Theapproach used in this study could be helpful in investigatingthe formation of conjugates from other carcinogens.     

Persistence of carcinogenic effect in intact progeny of mice treated transplacentally with 7,12-dimethylbenz[a]anthracene

Pregnant SHR mice were treated once with 7,12-dimethylbenz[a]anthracene (DMBA) on days 17-19 of gestation. F1 and F2 descendants of these mice received multiple skin applications of 12-O-tetradecanoylphorbol-13-acetate (TPA) twice a week for 24 weeks beginning at 12 weeks of age, or applications of solvent alone. The increase in the frequency of skin tumours in F1 and F2 descendants was reported elsewhere. In addition, we report here an increase in overall numbers of tumor-bearing animals, independently of TPA treatment both in F1 and F2 groups compared to respective control groups. Separate statistical analyses were performed for lung tumours, mammary gland tumours, leukaemias and lymphomas. In both generations of descendants of DMBA-treated mothers lung tumour incidence was considerably increased and differed significantly (maximal P-value = 0.003) from control values. Local applications of TPA resulting in strong skin tumour promoting effect described in our previous paper (Napalkov et al., Carcinogenesis, 8(3) (1987) 381) did not produce any significant change in the rates of other types of tumours. The results of the present study provide additional evidence in support of the hypothesis on possibility of hereditary transmission of carcinogenic action of certain chemical compounds.     

Characteristics of the vestibulo-ocular relations in patients with lesions of the central regions of the vestibular system]

Vestibular-ocular relations were studied in 30 patients with central vestibular affections varying in origin. Use was made of sinusoidal rotation with eyes closed and glance fixation tests. Symptoms of vestibular-ocular dysregulation typical for stem-cerebellar abnormalities were identified.