In this study, a plasmid was integrated into nisP, creating the first defined mutation in a nisin biosynthetic gene. The mutant strain secreted fully modified nisin with the N-terminal leader still attached. The presence of the leader was corfirmed by N-terminal sequencing of the purified precursor. The dehydration and lanthiomne formation of the precursor were already completed as active nisin could be formed by cleaving the leader from the inactive precursor by a trypsin treatment or by incubation with wild type cells. Nisin immunity of the NisP mutant strain was lowered to about 10% of the wild type immunity. The results show that NisP is needed for precursor processing and for development of high immunity of nisin.

A rapid method to obtain large amount of VLDL and LDL by ultracentrifugation is described. The mixture of VLDL and LDL was isolated and concentrated from plasma by an ultracentrifugation at 265 000 g for 2 h. VLDL and LDL were separated and purified by a further ultracentrifugation at 265,000 g for 3 h. This method combines the advantages of both sequential flotation ultracentrifugation and density gradient ultracentrifugation. It can process a large volume of plasma in a short time. The purity of isolated VLDL and LDL was confirmed by the lipoprotein electrophoresis on agarose gel and PAGE and by the apolipoprotein electrophoresis on SDS-PAGE. This rapid economical method is of great value in practical application.

One hundred and sixty-nine patients with posttransfusion hepatitis (PTH) were investigated for etiology with serological and PCR methods. Our result showed that HCV was the major causative agent of PTH in this study. A part of patients (24/169) were also HBV markers positive. Three patients were negative for all detected viral markers, looking forwards to progressive study. Anti-HCV was detectable from 7 days to one year after onsetting of clinical symptoms, average time 54. 62 days. HCV RNA could be detected in early time of HCV infection (6 to 20 days later), average time 8. 72 days. A follow-up study of 84 patients showed that all patients remained anti-HCV positive during the observation for 1. 5-3 years, but their HCV viremia had three forms: transient, persistent or intermittent. The interaction between HCV and HBV by their superinfection was unknown, awaiting further study.

The aim of this experiment is to study the mechanism of APN in alleviating the Ca²⁺-overloading in dog model during the process of ischemic reperfusion. In comparison with the sustained ischemic group, the parameters in the ischemic reperfusion group demonstrated: Ca²⁺ of ischemie region of myocardial cell increased (P<0. 05). Na⁺ increased remarkablyP<0. 01), the activity of Ca²⁺-ATPase dropped remarkably (P<0. 01),and MDA increased significantly (P<0. 01). Whereas in the group pretreated with APN, the Ca²⁺ in the relevant area reduced (P<0. 05), Na⁺ decreased significantly (P<0. 01), the activity of Ca²⁺-ATPase and Na⁺-K⁺ ATPase increased remarkably (P<0. 01), and MDA decreased significantly (P<0. 01). These findings indicate that APN may improve the activity of sarcolemma ATPase in alleviating the Ca²⁺ and Na⁺-overloading by decreasing the harmful effect of oxygen free radicals.

Using whole-cell patch-clamp technique, the present studv examined the effects of captopril on membrane currents of ventricular myocytes. The re suits were as follows: when the concentration of captopril was 6× 10⁻⁴ mol the fast inward sodium current and slow inward calcium current were all decreased significantly (P <0. 05). Besides, when the concentration exceeds 10⁻³ mol, the delayed rectifier potassium current was increased (P <0. 05) as well But if the experimental concentration was under 6 × 10⁻⁴ mol, these three kinds of currents was not affected. These findings suggested that captopril has no direct antiar rhythmic effect at the average therapeutic serum level.

To evaluate the effects of warm blood cardioplegic solution on myocardial protection, normothermic induction and terminal perfusion of oxygenated blood cardioplegia in combination with intermittent administration of cold blood cardioplegia during ischemia were studied in an isolated working rat heart model. The experimental protocol consisted of a 120 min cardioplegic arrest followed by 45 min normothermic reperfusion. Myocardial content of adenosine triphosphate (ATP), recovery of the left ventricular function, release of creatine phosphokinase (CPK) and ultrastructure of myocardium were assessed before and after ischemia. The results showed that the hearts preserved with warm blood cardioplegic induction and terminal perfusion had significantly higher levels of ATP, better recovery of cardiac function and lower releases of CPK than those receiving cold blood cardioplegia alone, with myocardial tissue being of generally normal structure. These findings suggest that warm induction and terminal perfusion of blood cardioplegic solution can accelerate myocardial metabolic and functional recovery, preserve high-energy phosphate, reduce myocardial injury and enhance myocardial protection.

The experimental models of cultured porcine aortic endothelial cells (EC)in vitro were established. 6-keto-prostaglandin F_1a (6-keto-PGF_1a), thromboxane B₂(TXB₂)content, plasminogen activator (PA), plasminogen activator inhibitor (PAD activity in cultured medium and cyclic adenosine monophosphate (cAMP) level in EC were measured with radioimmunoassay (RIA), chromogenic substrates methods, in order to assess the effect and mechanism of captopril (CP) on antithrombus function of EC. The results showed that after administration of CP, the contents of 6-keto-PGF_1a and cAMP and PA activity were significantly higher, PAI activity were remarkably lower than those of control group. These effects were dose-dependent. Our finding indicated that CP might act as a prospective drug for antithrombosis through promoting anticoagulation and fibrinolysis function and increasing antithrombus action of EC.

Primary tumor tissues in the digestive system were harvested form 15 patients. By mincing, enzymatic digestion and gradient density separation, sufficient TILs (>5 × 10⁶) were obtained from 13 of 15 (88. 7 %) patientsin vitro in the presence of 500 μ/ml of recombinant interleukin-2 and 5 % fetal calf serum after one month culture. 92. 3 % (12/13) of TILs proliferated wellin vitro (92. 3%). TILs expanded from 10²-folds to 10³-folds after being cultured for one month. CD₂₅⁺ cell of the most fresh TILs was more than that of peripheral blood lymphocytes. CD₂₅⁺ cells of TILs during 4th week of the culture was significantly greater (P <0. 01) than that of fresh TILs. CD₄⁺/CD₈⁺ ratio was decreased during four culture weeks because of increase of CD₈ cells. By using modified colonmetric MTT assay for measuring activity of TILs against various tumor cells the results showed that cytotoxicity of gastro-intestinal TILs amtologous tumor cells is greater than on the other tumor cells.

The pulmonary arteriole remodeling in Wistar rats with respiratory infection induced by mycoplasma pneumoniae was observed using light microscopy and morphometry. The pulmonary artery pressure (PAP) and index of right ventricular hypertrophy (RVHI) were measured. The intimai and medial hypertrophy can be seen in the pulmonary arterioles, leading to vessel wall thickening and narrowing of the lumina. The total number of the pulmonary arterioles decreased (P <0. 01), and both pulmonary hypertension (Ppa 4. 11±0.19 kPa) and right ventricular hypertrophy (RVHI: 34. 96±3. 91 %) occurred. In addition, an interstitial pulmonary fibrosis (IPF) was found, in which the content of collagen in the lung tissue changed, i. e., type I collagen increased whereas type I one decreased, and the ratio of type I collagen to type I one increased. It suggested that respiratory infection induced by repeated MP may result in remodeling of pulmonary arterioles and are closely related to pulmonary hypertension.

The chest and abdomen impedance respirographs (IRG), including the one dimensional IRG and the two dimensional IRG were designed and produced by applying the principle of bioelectrical impedance. Using IRG the non-synchronized chest and abdomen respiratory motions occurring in diaphragmatic fatigue were measured. The results showed that all 203 normal controls showed synchronized style of chest and abdomen respiratory motions. In 189 COPD patients 117 (61. 9%) showed non-synchronized respiratory motions which could be further divided into three types: type I showed complete contra-directional respiratory movements of chest and abdomen respiration, with M>24 % and a angle >120°; type I showed staggered peak of the chest and abdomen motion curves (13 %<M< 24 %), 50°<α angle<120°; type I showed double peaks of abdomen trace in the one dimensional IRG and “8”-shaped double circles on the two dimensional IRG, (M<13 %, 50°<α angle<120°. When compared with trans-diaphragmatic pressure (Pdi) and diaphragm myoelectricity frequency spectrum, the rates of conformity were 81. 8 % and 90 %, respectively, suggesting that IRG could be reliably used for diagnosing diaphragmatic fatigue. This technique is simple, easy to use, cheap and pain-free.

Reported in this paper are 8 cases of corrected transposition of the great arteries associated with anomalies. All the patients underwent the repair of the ventricular septal defect and atrial septal defect, the replacement of left-side tricuspid valve, the pulmonary valvotomy and the placement of extra-cardiac conduit to the pulmonary trunk respectively with no hospital death after operation. The paper also described the selection of the heart incision, the prevention of injury of the conduction system and indication of the placement of extra-cardiac conduit.

In this article, we invertigated changes of immune functions and immunoregulatory effects of indomethacin on rats with trauma. The results show that spontaneous suppressor T cell activity of spleen significantly increased and Interleukin 2 production and DNA synthesis capacity of splenocytes markedly decreased in rats with trauma. Indomethacin could markedly improve immune function, decreased spontancous suppressor T cell activity and prompted Interleukin 2 production and DNA synthesis capacity of splenocytes.

Patients with obstructive jaundice have a high susceptibility to infection in the process of treatment and the reason for this is not fully understood. It was postulated that it may bear some relations to abnormalities of immune function. In this article, 28 cases of obstructive jaundice were selected to investigate alternation of monocyte immune function with the purpose of exploring mechanism of high susceptibility to infection from the perspective of immunology. The results showed that interleukin 1 production by monocytes significantly decreased and prostaglandin E₂ increased, HLA-DR expression of monocytes was markably depressed. HLA-DR expression of monocytes was further decreased with recovery slower than non-jaundiced patients after operation. All this may be responsible for high susceptibility to infection in the process of treatment of obstructive jaundice.

Five fresh tibias removed from 30–40 years old dead males were osteotomized at one-third supra-medium segment and then fixed by an unilateral adjustable external fixator (UAEF) to be used as a model of external fixation of tibial fracture. For each loading test under different configurations of UAEF, the ratio of the force-displacement was used to determine its stiffness value. The weakest mode of the UAEF device is in AP bending. Under each mode of compression, distraction, enteroposterial and lateral bending and torsion loading, increasing the pin number or pin diameter or pin separation, and/or reduction of pin group separation can significantly increase the stiffness values of UAEF (P<0. 01). These data revealed that UAEF is suitable for the external fixation of tibial fracture.

We present a detailed outline of treatment of intertrochanteric fractures of femur with a new technique on the basis of principles of combined traditional chinese and western medicine. We use pins and an outer fixation frame, which keeps the injured limb in abduction and under traction and at the same time allows for functional exercise of all the joints in the extremity. The procedure is discussed and compared with other different techniques.

The intestinal Oxalobacter Formigenes were isolated in 30 cases of urolithiasis and in 45 controls. The biologic characters and morphology of the bacteria were also observed. The results showed that the colony counts in urolith group 9 (mean l0³/g. faeces) were significantly less than that of controls (mean l0⁸g. faeces) (P<0. 001). It is believed that the lesser amount of oxalobacter formigenes in urolith was the important factor of the calcium oxalate calculi formation.

In this article, we report139 autopsy cases of medical tangle, which were examined by the Department of Forensic Pathology, Faculty of Medicine, Tongji Medical University from Jan.1972 to Dec.1992. The emphasis is put on analyses of the status of medical tangle autopsy in forensic pathology, involved medical departments, distribution of victim’s age and sex, differences between clinical diagnosis and autoptical conclusion, the composition and causes of medical tangle. The associated problems in forensic pathological autopsy are also discussed.