ROLE OF f3-RECEPTOR IN THE RADIX ANGELICAE SINENSIS ATTENUATED HYPOXIC PULMONARY HYPERTENSJON IN RATS

Acute pulmonary hypertension was caused by inhalation of 5% 02 in rats. Pulmonary vascujar re- sistance (PVR) increased, but heart rate (HR), cardiac output (CO) and carotid arterial pressure (CAP) were not obviously changed. After an intravenous admini- stration of Radix Angelicae sinensis, the acute pulmonary hypertension induced by inhalation of 5% O2 could be attenuated, but this effect disappeared if propranolol was given before Radix Angelicae sinensis. In chronic experiments, the same results were obtained, but the protective effect of Radix Angelicae sinensis on heart function was not influenced by propranolol. It is suggested that Radix Angelicae sinensis rmght play a role by stimulating the βz-receptor in the prevention of acute and chronic hypoxic pulmonary hypertension. However, prevention of hypertrophy of the right ventricle and enhancement of heart function in chronic hypoxic rats might not be attributed to the β1 receptor in the heart.     

The interaction between the activator agents batrachotoxin and veratridine and the gating processes of neuronal sodium channels

The depolarization of frog sciatic nerves by the Na channel-activating toxins, batrachotoxin and veratridine, was studied using the sucrose-gap technique. To study the interaction between the activators and the gating processes of Na channels, we measured the depolarizations of unstimulated nerves, of nerves during repetitive stimulation, and of nerves whose Na channel inactivation process had been pharmacologically modified. Stimulation enhanced the rates of depolarization by the activators but did not effect the steady state depolarization values. Of the three inhibitors of Na channel inactivation that were tested (Leiurus alpha-scorpion toxin, chloramine T, and Ni2+), only Leiurus toxin enhanced the potencies of the activators. Neither chloramine T nor Ni2+ had any effect on the steady state level of depolarization produced by either activator. Both chloramine T and Ni2+, however, enhanced the rate of batrachotoxin action, although neither affected the rate of veratridine action. Leiurus toxin also potentiated the effects of the activators in chloramine T-treated nerves. We tested the interaction between the Na channel activators and a class of agents, local anesthetics, that stabilize a non-conducting state of the Na channel. The presence of lidocaine inhibited the depolarization produced by addition of either activator, although the addition of lidocaine subsequent to the development of batrachotoxin-induced depolarization produced repolarization very weakly and slowly. We also found that the lidocaine homologue, RAC 109I, was about 3 times as potent as its stereoisomer, RAC 109II, in its ability both to reduce the compound action potential amplitude and to inhibit the veratridine-induced depolarization.     

电视传媒在健康知识传播中的作用

电视传媒已成为人类生活中不可缺少的一部分，承担着传播知识与文化的重要任务。电视传媒对一个民族的思想文化影响力、提高该民族在国际社会中的整体形象，都具有不可替代的作用。20世纪80年代，许多健康教育机构就已经开始利用影视传媒手段为健康教育服务，并取得了明显成效。     

COMPARATIVE STUDY OF AMINO ACID CONTENTS AND LDH ISOZYME BY ELECTROPHORESIS AND SLAB-PAGE IN ADULT WORMS OF ASCARIS LUMBRICOIDES, ASCARIS SUUM AND TOXOCARA CANIS^

Comparative studies are made on the relative percentages of amino acid content and LDH isozyme by electrophoresis and Slab-PAGE in adult worms of Ascaris lumbricoides, Ascaris suum and Toxocara canis. The results show that there are remarkable differences of Arg and His of 17 amino acids bet. ween Toxocara canis and human intestinal ascaris, human biliary ascaris and pig ascaris; there are also obvious differences of band positions of LDH isozyme electrophoretic patterns and band position and amount of slab-PAGE patterns among them, whereas no marked differences are found in these three indices in human intestinal ascaris, human biliary ascaris and pig ascaris.     

In vitro modulation of cisplatin cytotoxicity by sparsomycin inhibition of protein synthesis

Inhibition of protein synthesis can alter cellular responsiveness to the classical anticancer drugs. The in vitro response of Chinese hamster ovary (CHO) cells to cisplatin with or without sparsomycin (Sm) was studied with the use of [3H]leucine and [methyl-3H]thymidine incorporation and clonogenic assay. Pretreatment of exponentially growing CHO cells with 1 microgram Sm/ml for 3 or 5 hours decreased [3H]leucine incorporation by 20% and resulted in significant resistance to cisplatin (P = .005). Sm in a concentration of 10 micrograms/ml reduced [3H]leucine and [methyl-3H]thymidine incorporation after 3 hours by 92 and 84%, respectively, and resulted in potentiation of the cisplatin cytotoxicity (P = .004). This effect was the same in the case of nonproliferating cells (P = .005), while protection due to Sm (1 microgram/ml) was seen only during cell proliferation. Simultaneous incubation and postincubation with Sm proved to have much less or no potentiating effect on cisplatin. The mechanisms of both protection and potentiation are still not clear, but our data indicate that Sm is a promising drug for further studies on the modulation of the cancer cell response to classical anticancer drugs.     

The use of axial-pattern cutaneous and musculocutaneous flap transposition in the reconstruction of deep burns

From June 1979 to July 1987, 84 acute burned patients with localized deep wounds involving tendon, nerve, vessel, bone and joint were treated by utilising 26 types of island axial-pattern cutaneous or musculocutaneous flaps. All flaps survived completely with a primary healing rate of 91.4%. All patients were divided into 'urgent' (within 48 hours), 'early' (within 2 weeks), or 'infected' groups according to the time interval between the burn injury and the surgery conducted. The primary healing rates for each groups were 100%, 94%, and 86% respectively. No significant differences exist between the axial-pattern cutaneous flap and musculo-cutaneous groups. The measures for minimizing infection including thorough debridement, groups. The measures for minimizing infection including thorough debridement, avoiding of circulatory compromises of the flaps, effectively postoperative drainage, and the use of antibiotics were discussed. Four types of newly developed axial-pattern cutaneous flaps as well as a super-long latissimus dorsi-external oblique abdominis-rectus abdominis combined musculocutaneous flaps were presented.     

Flow cytometry in clinical oncology: cell cycle and DNA ploidy in assessing tumor behavior

The basic principles of flow cytometry with special emphasis to cell cycle analysis and DNA ploidy measurements are described. The concept of separation of various subcompartments of cell cycle, distinguished by simultaneous determinations of DNA versus RNA and DNA versus protein contents is presented. Based on DNA ploidy patterns, human tumors were divided into two groups designated as diploid range and non-diploid (aneuploid). Since it has been proposed that diploid range tumors have generally better prognoses than non-diploid tumors, the value of DNA ploidy patterns as a prognostic factor is discussed in major groups of human cancers.