Microinjection of angiotensin (A II), 4 μg, into the subnucleus commissuralis of nucleus tractus solitarii (CNTS) was made in rabbits under urethane anesthesia in order to investigate its cardiovascular effects. Experimented animals were divided into five groups: 1. In control group 0.5 μ1 of normal saline was injected into CNTS. There was no significant change in mean arterial pressure (MAP) and heart rate (HR). 2. AII, 4 μg, dissolved in 0.5 μ1 saline was injected into the same region. MAP increased markedly, and HR decreased. 3. After severing bilateral sinus nerves and depressor nerves, 4μg of AII was injected. MAP increased more markedly, but HR showed slight reduction. 4. After microinjection of 4 μg A II into CNTS, the arterial baroreceptor reflex sensitivity (ABS) was determined by means of i. v. injection of adrenaline (5 μg/kg). ABS showed no significant change. 5. Previous injection of naloxone (3nmol) did not influence the pressor response to AII. The results suggest primary effect of the microinjection of AII into CNTS on vasomotor neurons without apparent effect on the cardiac neurons, and no effect of the endogenous opioid system in CNTS on the pressor response to A II during resting condition.

By quantitative estimation of the density ratios of cholinesterase (ChE) isoenzyme bands, we have analysed 100 cases of normal amniotic fluid, and 31 cases of amniotic fluid with malformed fetus. In order to distinguish amniotic fluid with blood contamination from that with non-contamination, blood contaminated amniotic fluid has been assayed at the same time. The results show that 1) the amniotic fluid with blood contamination has five more bands of ChE isoenzyme than that with non-contamination; 2) the ChE isoenzyme band 3/2 density ratios of amniotic fluid with blood contamination and with multimalformation, omphalocele, encephalocele are all ≤S 0.089. These ratios in normal single and twins fetal amniotic fluid are all zero; while those in anencephaly or anencephaly plus spina bifida are all ≥0.11. Therefore, according to the above results we can not only identify the blood contaminated samples but also diagnose and distinguish various forms of malformed fetus.

A comparative study of the roentgenologic signs and pathological changes in experimental subacute fluorosis was carried out. The plain X-ray films, taken at the end of the first and the second months, revealed that the long bones of the extremities, especially in the anterior limbs, had localized osteoproliferation in the cortex, prominence of the cortex, unevenly thickening of the cortex. Pathological examinations demonstrated osteoporosis of different degree in the cortex of the same areas. In cross section the typical specimens appeared porous and spongy. Microscopically, the haversian system was found to be distorted, the lumina of the canals were irregularly dilated, and the number of micrangia was increased. In the inner wall of the canals the osteoblasts were densely crowded and linearly arranged, and the osteoclasts depressed. Under the fluorescent microscope, the growing skeleton of the experimental animals, labelled by tetracycline, showed disappearance of the endogenous growth zone and the double fluorescence lines. Other changes, such as external shifting, winding, thickening as well as irregular pattern, could also be observed. The formation of new bone was irregular. All these suggested that the long bones of the domestic rabbit were affected by fluorine in growth and development.

The blood-level of β₂-microglobulin (β₂-mG) in patients with Graves disease is generally elevated, varying with the condition of the patients. After treatment with Tapazole, the blood level of β₂-mG is gradually lowered to normal range with improvement of the disease. In this study the mechanism and significance of such variations of β₂-mG in Graves disease patients were investigated by observing suppressor T-lymphocyte function (expressed as suppression index, SI). At the same time the blood levels of β₂-mG of the same subjects were determined. It was found that the quantitative variation of the blood β₂-mG was related to the condition of patients as well as to the status of immunologic system. The high level of blood β₂-mG was probably due to the dysfunction of suppressor T-lymphocytes. The measurement of blood β₂-mG was much easier than that of SI, and possibly, the former could be used instead of the latter to show the function of cell-mediated immunity in patients with Graves disease.

Application of conventional ultrasonography in the diagnosis of rectal cancer is in itself very difficult. The authors have designed a new device called “Water Ballon-Aided Ultrasonography”. With the aid of the echofree zone and “acoustic window” effect formed by the water ballon, complete knowledge of the location, size and extension of the rectal cancer can be acquired, and the distance of the tumor from the the lower margin of the anus and the possibility of any infiltration to the adjacent organs can be detected, thereby enabling the surgeon to estimate the resectability of the tumor accurately and select suitable surgical approach. In this respect the water ballon-aided ultrasonography is much superior to other conventional examinations.

A high-pressure digestive vessel was designed and used in the pretreatment of samples of human body materials. The method has been used in combination with neopolarographic anodic stripping voltammetry, oscillographic anodic stripping voltammetry and graphite furnace atomic absorption spectrometry for trace analysis of lead in blood, hair and nails. The percentage of recovery amounted to 97.1–99.1%. The analytical results obtained by pretreatment with the device demonstrated that the sensitivity and accuracy of analysis can be effectively increased by employing our device.

The relationship between the patterns of expression of HBsAg and HBcAg and liver cell necrosis in liver tissue of 83 patients with chronic liver diseases has been studied. The results suggest that the membranous expression of HBsAg and HBcAg is associated with the activity of the liver diseases. Cytoplasmic-membranous HBcAg may be the main target antigen attacked by host immune system, thus leading to liver cell necrosis, but the possibility of the relation of membranous expression of HBsAg to liver cell necrosis can not be excluded. Various factors affecting the host immune function and the relationship between membranous expression of HBAg and liver cell necrosis were discussed in the present paper.

To induce the expression of fragile sites, PHA-stimulated lymphocytes during the last 24 h of culture were incubated either in 199 medium which is relatively deficient in folic acid or in 1640 medium supplemented by MTX or FdU. Blood samples from 20 patients and 12 controls were examined. At the same time the cytogenetic study of bone marrow cells from the patients was also conducted. The results show that both the rates of chromosome aberrations and the expressive frequencies of fragile sites in normal cells of the patients were much higher than in those of the normal controls. Besides, there was a close relationship between the fragile sites, the cancer breakpoints and the oncogenic loci. It was also found that the rates of chromosome aberrations were significantly increased in patients who had received chemotherapy, but the expressive frequencies of fragile sites were not. The possibility of detecting susceptible individuals by the study of their fragile sites is proposed.

The effects of insecticide Isophenphos-I on respiration of rat liver mitochondria were studied. It was found that Isophenphos-I inhibited the respiration of mitochondria both in vivo and in vitro, and reduced the activities of glutamate dehydrogenase, succinate dehydrogenase, succinatecytochrome C reductase and Mg⁺⁺-ATPase in vitro. The effects of the insecticide on the permeability and lipid peroxidation of the mitochondrial membrane were also investigated in vitro in order to explore the possible mechanism of the respiratory inhibition of mitochondria by the insecticide.

Heat and carbon monoxide (CO) are the two common, co-existing hazards encountered in industry.

Our researches showed that high temperature could enhance the toxicity of CO, on the other hand, CO could affect thermoregulation and reduce heat tolerance of the body. According to the results obtained, we made constructive amendments to the health standard, in order to safeguard the workers health and their productive capacity.