1987年 · 第100卷第09期

An experimental study on the cytotoxic effects of hyperbaric oxygen combined with photodynamic therapy (HBO-PDT) on mouse transplanted tumors S180 and Ca759 was carried out using a self-designed device of laser irradiation in hyperbaric oxygen chamber. The results re-vealed that HBO combined with PDT had a stronger tumor-cytotoxic effect than PDT alone (p<0.01). This study provided evidence for the theory that singlet-state oxygen plays an important role in PDT, and clarified the mechanism that mitochondria is initially implicated in the damage.

The biphasic effects of prostaglandin E2 (PGE2) in high and low doses on experimental atherosclerosis were studied. In comparison with the control group given the atherogenic diet only, the animals receiving high dose of PGE2 injections and cholesterol diet displayed far less atherosclerotic lesions and less aortic uptake of 3H-cholesterol. Moreover, PGE2 in high dose markedly inhibited the DNA synthesis of smooth muscle cells and platelet aggregation. PGE2 in low dose, however, showed an opposite effect. It is suggested that intravenous low dose of PGE2 may accelerate atherogenesis, and exogenous high dose of PGE2 may have a preventive effect on atherosclerosis.

This paper reports 6 cases of tinea capitis caused by Microsporum nanum first seen in China. All these patients had a history of contact with pigs. Their clinical appearances were similar to those of kerion. The pathogenic organism were confirmed by direct KOH examinations, mycological cultures and scanning electron microscopy. Because the raising of swines is popular in China, such zoonoses may not be rare. Therefore, it is worth while to pay more attention to the prevention of such zoonoses.

Compressive staples made of Ni-Ti shape memory alloy were used as internal fixation devices in 51 cases of bone and joint surgery. They exert compression, keeping bone fragments in intimate contact, expediting bone healing and enabling earlier mobilization for functional recovery. Judged by the clinical, roentgenological and histological evidence, Ni-Ti shape memory alloy is an ideal material for internal fixation and produces no tissue reaction.

Results of double-blind observations on volunteers eating 35 kinds of irradiated foods as their main diet for 90 days are reported. They included 70 medical students and 8 staff members of Shanghai Medical University and were randomly divided into two groups. One group was supplied with irradiated food, the other served as controls, taking the same diet of nonirradiated foods. The 35 kinds of irradiated foods consisted of grain, meat products, vegetables, fruit, dried fruit, etc. The absorption dose of irradiation of the processed foods varied from 0.1 to 8.0 kGy. The irradiated foods accounted for 60.3% of the total intake by weight. All subjects were satisfied with their diets and no adverse effects on health were noted. Clinical and laboratory examinations included routine blood and urine tests, blood biochemical examinations, hepatic and renal function tests, endocrinological assays, cellular immunity tests and mutagenic studies including the incidences of polyploid cells, chromosomal structural aberration, rates of sister chromatid exchanges, micronuclei test and urine Ames test. The results of this investigation showed that these foods are safe for human consumption.

In order to establish the relationship between hypomagnesemia and heart complications in diabetes mellitus, the magnesium levels of serum, erythrocytes, and urine in 109 diabetics and 130 normal controls were studied. It was found that serum and erythrocyte magnesium levels were significantly lower, and urine magnesium significantly higher in the diabetics than in the controls. Serum magnesium in diabetics with heart complications (n=17) was significantly lower than that in diabetics without heart complications (n=92). The results obtained by multiple regression analysis suggested that hypomagnesemia, hypertension, and body mass index contribute to the occurrence of heart complications in diabetics. It was believed that hypomagnesemia may be one of the risk factors for heart complications in diabetes mellitus.

We studied normal lumbar intervertebral discs of rat, rabbit and man (fetus and adult) by transmission electron microscope. It was found that although the annulus fibrosus was composed of fibrocartilage, the cells in the lacunae of the fibrocartilage showed configuration transition from fibroblasts to notochordal cells. Elastic fibers could be detected in the annulus. Nucleus pulposus contained notochordal cells which may exist singly or in stacks in a loose matrix. In patients with protruding or ruptured lumbar intervertebral discs, the diseased disc material originated from the nucleus pulposus, the superficial stratum of the annulus fibrosus, and the cartilagi nous tissue. Both living and degenerate notochordal cells existed in the nucleus pulposus. In the cartilaginous tissue, chondrocytes showed active secretory function or underwent interstitial growth and degeneration. The cellular component of the superficial stratum of the annulus fibrosus was comprised mainly of living fibrocartilage cells similar to fibroblasts.

The concentration of vitamin E in the brains and livers of dam and pup rats with or without vitamin E supplement was determined. The results show: Vitamin E administered during pregnancy can get access to the fetal brain; their blood-brain barriers possess a free permeability to vitamin E; and the premeability is higher in pups than in dams, which implies the development of blood-brain barrier with age.

Mixed function oxidase (MFO) was prepared and analysed for its activity from the mucosa of stomach resected from stomach cancer patients and noncancer ones from counties with different incidences of the disease in Fujian Province, which is a high incidence area of gastric cancer in Southeastern China. MFO activity of nonstomach cancer patients in high and low incidence areas is significantly different (p<0.01). MFO activity in stomach cancer and nonstomach cancer patients is also significantly different. Meanwhile, differences in the contents of gastric mucosa cytochrome p-450 of noncancer patients from high and low incidence areas of stomach cancer and in stomach cancer and noncancer ones are not marked (p>0.05). MFO of human gastric mucosa is capable of metabolizing diethylnitrosamine in vitro.