Studies on the mechanism of the toxic action of sodium nitrite on intestinal absorption in rats

The biochemical parameters Na⁺/K⁺-ATPase, alkaline phosphatase, oxygen consumption, and lactic acid level were evaluated in the small intestine mucosa of male Wistar rats duringin situ perfusion of the rat with sodium nitrite. Sodium nitrite was poorly absorbed (10% of the administered dose), but it inhibited the activity of Na⁺/ K⁺-ATPase and alkaline phosphatase. It had no effect on the lactic acid level, pointing to normal oxygen in the intestine, evidently reducing the utilization of oxygen by this tissue. Using metabolism inhibitors added to the perfusion fluid in the concentrations: ouabaine 0.1 mM, NaN₃ (sodium azide) 1 mM, L-phenylalanine 50 mM and during functional ischaemia of the intestine produced by occlusion of the superior mesenteric artery for the time of the perfusion, it was possible to find the site of action and the direction of the toxic influence of sodium nitrite.     

ACTH in the plasma and cerebrospinal fluid in patients with multiple sclerosis

In 1984 and at the beginning of 1985 the authors carried out radioimmunoassays (SORIN-CIS kit) the plasma levels of ACTH in 116 multiple sclerosis patients (m-52, f-64) and in 10 cases this radioimmunoassay was done in the cerebrospinal fluid (m-5, f-5). The control group comprised 90 patients with ischialgia and neuroses. The normal value in the plasma was from 0 to 80.86 pg/ml, and in the fluid it was from 0 to 77.08 pg/ml. In multiple sclerosis patients the plasma ACTH level was from 0 to 286.9 pg/ml, in the cerebrospinal fluid from 0 to 89 pg/ml. The values of ACTH were significantly higher in multiple sclerosis patients, mainly in males. In the fluid the level of ACTH was significantly higher in the studied patients. No significant differences in ACTH levels were found between males and females with multiple sclerosis, and in the control group this level was higher in females. Raised ACTH level was found mainly in multiple sclerosis with lung duration of the disease (10 years) at the time of exacerbations. The authors continue studies on the axis hypothalamus-hypophysis-adrenals, on various hormones, prostaglandins, beta-endorphin, biochemical markers, cAMP, cCMP, arylosulphatase A and B MBC etc.     

Synergistic effect of organic solvents and tobacco smoke on the indicators of humoral immunity in humans

Medical examinations were performed among 49 non-smokers, 47 workers who had been smoking for more than 10 years, 19 non-smokers exposed to organic solvents and 41 smoking persons occupationally exposed to organic solvents. Both cigarette smoking and the action of organic solvents. decreased the levels of IgA, AgG, IgM and that of lysozyme. In persons exposed to the actions of both cigarette smoking and benzol and its homologues, more significant decreases of IgA, AgG, IgM and lysozyme concentrations were revealed as compared to those affected by one of the factors. The same concerned the IgD level. The contributors proposed that cigarette smoking should be taken into account when evaluating the immunotoxic properties of industrial factors.     

Vitreous body proteins. IV. Proteolytic activity of the vitreous body in pathological conditions of the eye]

Two groups of proteins are present in the vitreous: collagen and non-collagen, deriving probably from the blood serum. The authors examined the proteolytic activity against haemoglobin in the course of some ocular pathological conditions. It was demonstrated that the vitreous digests haemoglobin in the acid division of pH (optimum--3.0-4.5) with various activity dependent on the pathological condition of the eye.     

Extrapulmonary location of sarcoidosis.

Two cases of sarcoidosis located outside the lungs are reported. In both cases the symptoms of the sicca syndrome were in the foreground. In the first case other clinical manifestations included mediastinal and retroperitoneal lymphadenopathy, and lacrimal gland impairment. In the other case the symptoms of the sicca syndrome were associated with polyneuropathy and maculopapular skin rash. The diagnosis of sarcoidosis was confirmed by histological examination of a biopsy specimen of lower lip mucosa in the first case, and biopsy of skin lesion in the second case. Abnormal results of laboratory tests included only raised erythrocyte sedimentation rate, in both cases and presence of circulating immune complexes in one case. Serological tests failed to demonstrate the presence of rheumatoid factor, antinuclear and anti-ds DNA antibodies. No decrease was observed also in the haemolytic activity of the complement, and cryoglobulins were absent. Regression of clinical signs was obtained in both cases after treatment with glucocorticosteroids.     

The prodynorphin system in the rat hippocampus is differentially influenced by kainic acid and pentetrazole.

Administration of kainic acid (15 mg/kg, i.p.) or pentetrazole (75 mg/kg, i.p.) to rats evoked recurrent limbic or tonic-clonic seizures, respectively. Radioimmunoassay showed that the level of alpha-neoendorphin (prodynorphin-derived peptide) in the hippocampus was decreased after 3 h (by c. 60%) and 72 h (by c. 40%), but was not changed after 24 h following kainic acid administration. The basal release of alpha-neoendorphin from hippocampal slices of kainic acid-treated rats was decreased after 3, 24 and 72 h following the drug injection by c. 50%. The K(+)-stimulated release was decreased after 3 and 24 h (by c. 300 and 200%, respectively) and was back to the control level after 72 h. An in situ hybridization study showed that kainic acid strongly enhanced the prodynorphin messenger RNA levels in the dentate gyrus after 3 and 24 h (by c. 200%), whereas after 72 h it tended to decrease. Twenty four hours after pentetrazole injection the hippocampal level of alpha-neoendorphin was elevated (by c. 33%) and remained unchanged after 3 and 72 h. No significant changes in the basal or K(+)-stimulated alpha-neoendorphin release from hippocampal slices of pentetrazole-treated rats were found at any time points measured. Three and 24 h after pentetrazole administration the level of prodynorphin mRNA in the dentate gyrus was slightly decreased (by c. 30%), but was back to the control values after 72 h. Hence seizure-related changes in hippocampal prodynorphin neuron activity seem to depend on the experimental model of epilepsy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of various light sources on visual functions in the age aspect. I. Conscious reaction time and the manual spatial visual localization]

The authors present the results of investigations performed in 28 right-handed, normally seeing persons divided into 2 groups: 15 of them were in productive age and 13 in older age. The authors compared the dynamics of the behaviour of the visual functions in dependence on the age of the subjects and the stay in the glow and sodium light. No adverse influence of the sodium light on the hand localization could be detected, instead it seems that it negatively influenced the selective reaction in older productive persons in the sense of an increased number of faults.