1996年 · 第109卷第11期

OBJECTIVE To study the effect of nicotinamide (NAA) on prevention and treatment of STZ-induced diabetes mellitus in rats. MATERIAL AND METHODS 30 Sprague-Dawley rats were randomly divided inot three groups: 20 rats were given NAA 1 g/kg/day intramuscularly (10 rats) or orally (10 rats) as experimental groups and the other 10 rats by normal saline orally as control group. Three days later, all 30 rats received streptozotocin (STZ) 55 mg/kg by intraperitioneal injection and took NAA or normal saline continuously as described above for 14 days. During the study, fasting blood glucose (FBG) was measured before and 72 hours after STZ injection and every 2-3 days later on with Glucometer, 24 hours urinary glucose excretion (UGE) was determined once every 4 days with glucose oxidase, body weight was determined every week, the volume of 24-hour water intake and urine excretion were determined twice and once a week respectively. RESULTS Two weeks after STZ injection, FBG and 24 hours UGE of all rats taking NAA were normal or nearly normal, islet function and morphology revealed no significant differences compared with those of the normal, whereas all rats of control group remained hyperglycemic (>16.6 mmol/L) and markedly higher 24 hours UGE as compared with the normal islets appeared atrophic with decrement of B cell population. CONCLUSIONS The results showed that NAA may effectively prevent the occurrence of STZ-induced diabetes mellitus in rats, suggesting that NAA may be an effective agent for prevention and treatment of insulin-dependent diabetes mellitus (IDDM) in prediabetic and early stage of IDDM.

OBJECTIVE To investigate the possible role of endothelin-1 (ET-1) and atrial natriuretic peptide (ANP) in the pathogenesis of pregnancy-induced hypertension (PIH). METHODS A total of 110 normal pregnant women (in three trimesters, labour or postpartum) and 30 patients with PIH were studied by measuring plasma ET-1 and ANP levels by radioimmunoassay; 23 normal non-pregnant women were selected as controls. RESULTS Compared with normal non-pregnant women, plasma ET-1 levels were significantly decreased in normal pregnant women during all three trimesters. Plasma ET-1 level was significantly increased in the 2nd stage of labour, compared with that in the 3rd trimester. There were significant positive correlation between plasma ET-1 level and mean arterial pressure in normal non-pregnant women and normal pregnant women in all three trimesters. Compared with matched normal pregnant women, plasma ET-1 and ANP levels were significantly increased, while plasma ANP/ET-1 ratio was significantly decreased in PIH patients. Significant positive correlations existed between plasma ET-1 level and mean arterial pressure or the score index of the severity of PIH. After the treatment with magnesium sulfate infusion, plasma ET-1 and ANP levels were significantly decreased, but plasma ANP/ET-1 ratio was significantly increased in PIH patients. CONCLUSIONS Augmentation of ET-1 secretion and attenuation of ANP function may be responsible for the development of PIH. ET-1 secretion may be indirectly influenced by magnesium in PIH.

OBJECTIVE To examine the effect of rhG-CSF on allogeneic bone marrow transplantation. PATIENTS AND METHODS One hundred and twenty patients with acute or chronic leukemia received HLA-A.B.DR identical and MLC negative sibling donor allo-BMT. Among them, 58 cases of were treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF), while the other 62 cases of the 120 patients were treated as control. RESULTS Clinical results showed that the time taken to reach an absolute neutrophil count>0.5×109/L was significantly faster in patients who received rhG-CSF compared with control patients (16.24±0.25 vs 25.20±0.16 days. P<0.001), with significantly less early fever days in patients received rhG-CSF (1.17±1.10 vs 4.01±0.37 P<0.001). We did not observe any increase in acute GVHD and relapse in myeloid leukemia patients. But 7 of 16 patients with ALL relapsed after allo-BMT in rhG-CSF group, while only 3 of 11 patients with ALL relapsed after allo-BMT in control grant (P>0.05). This phenomenon has not been reported up to now. CONCLUSIONS rhG-CSF can promote engraftment and reduce early fever days after BMT. rhG-CSF has not any effect on a GVHD. The effect of rhG-CSF on leukemia relapse needs to be further studied.

OBJECTIVE To examine the safety and effects of gene therapy for hemophilia B by implantation of autologous fibroblasts genetically modified to secrete clotting factor IX (hFIX). PATIENTS AND METHODS Two hemophilia B patients LD and LW were selected from one family to accept gene transfer study. The hFIX protein of both patients were about 100 ng/ml plasma and hFIX activity was about 2%. The autologous skin fibroblasts of the two patients were genetically modified by retrovirus-mediated gene transfer with XL-IX and N2CMVIX vector (HBSF-IX). Human hFIX protein was measured by ELISA, hFIX activity was measured by one-stage clotting assay and barium citrate sorbent method. hFIX inhibitor was assayed by Bethesda methods. Human hFIX cDNA was detected by PCR. HBSF-IX cells were mixed with collagen for injection after safety assessments. RESULTS The HBSF-IX cells from the two patients secreted hFIX at high levels in vitro. After implantation of autologous HBSF-IX cells, no treatment-related side effects were observed. Plasma hFIX protein in both patients increased over 2 folds after several injections of HBSF-IX cells and persisted for more than 420 days. Blood clotting activity increased significantly in both patients, hemorrhagic tendencies have been partially corrected after treatment. Further elevation of hFIX can be achieved by repeating the same treatment 420 days later in Patient LD. CONCLUSIONS Implantation of autologous fibroblast genetically modified to secrete human hFIX offers a simple, safe and effective approach to gene therapy of hemophilia B.

OBJECTIVE To establish predicted values of membrane diffusing capacity (Dm) and pulmonary capacity blood volume (Vc), to compare the predicted values from our equations with those for Caucasians, to determine whether there are changes initially in Dm or Vc in patients with mild emphysema. PATIENTS AND METHODS Diffusing capacity for carbon monoxide (DLco), Dm and Vc were determined in 86 normal subjects and 16 patients using the single-breath diffusing capacity for carbon monoxide (DLcosB) with two different alveolar concentrations of oxygen. RESULTS The predicted equations are as follows. For males, DLco (ml/min/mm Hg)=0.37H-0.19A-27.8; Dm (ml/min/mm Hg)=0.65H-0.24A-53.7; Vc(ml)=0.88H-78.9. For females, DLco=0.28H-22.7; Dm=0.59H-53.6; Vc=66.6-0.36A. DLco and Vc are lower in Chinese than Caucasians while Dm is similar in Chinese and Caucasians. Eleven of 16 patients had a low DLco (<80% predicted value), 12 had a low Dm and 5 had a low Vc. Eight of 12 patients with a low Dm also had a low DLco, but in 4 the DLco was normal. Nine of 12 with low Dm had a normal Vc. CONCLUSIONS This study provides prediction equations of Dm and Vc. Chinese have a low DLco because their Vc is lower than Caucasians. The DLco and Dm are abnormal in a comparable percentage of patients. In patients with mild emphysema, the Dm becomes abnormal before the Vc.

OBJECTIVE To examine the prophylactic effect of artesunate on schistosomiasis japonica by killing schistosomula. METHODS Mice, rabbits and dogs after infection with cercariae of schistosoma japonicum (S. japonicum) were treated with artesunate on the 7th day at a dose of 300 mg/kg, 20-40 mg/kg and 30 mg/kg respectively once a week for 4-6 weeks. A double-blind test was used. A total of 864 persons in highly endemic areas for schistosomiasis were administered either artesunate at a dose of 6 mg/kg once a week for 8 weeks or identical placebo with the same dose-schedule during transmission season for S. japonicum. Four weeks after the last dosing, fecal examinations for S. japonicum eggs and miracidia were carried out to evaluate the prophylactic effect. RESULTS Worm reduction rates in mice, rabbits and dogs were 77.50-90.66%, 99.53% and 97.10% respectively. All of the 467 residents in 2 trials were free from eggs or miracidia upon stool examinations whereas in the control groups with placebo, 15 out of 218 (6.9%) and 26 out of 179 (14.5%) were stool eggs and/or miracidia positive in the first and second trial, respectively. Side effects were mild. No significant changes in routine blood and urine tests, electrocardiogram, hepatic and renal functions were observed after artesunate administration. CONCLUSIONS Animal experiments and field trials have demonstrated good efficacy of artesunate on killing schistosomula with little side effects. Thus, the drug is suggested to be used on the population in endemic areas for prevention of schistosomiasis.

OBJECTIVE To detect the factors responsible for the susceptibility of cervical keratinocytes infected with human papillomavirus (HPV) to non-specific lysis mediated by natural killer (NK) and lymphokine activated killer (LAK) cells. METHODS Five cervical keratinocyte lines: CaSki, SiHa, HeLa (representing high grade squamous intraepithelial lesion (HSIL) ), W12 (representing low grade squamous intraepithelial lesion (LSIL) ) and NCx, (normal cervix) were used as target cells in the four-hour lactate dehydrogenase (LDH) release cytotoxicity assay. The effector cells were NK and LAK. The modulatory effects of interferon gamma (IFNγ) and tumor necrosis factor α (TNFα) pretreatment of keratinocytes were investigated by adding IFNγ or TNFα into the flasks of target cells 48 hours before the cytotoxicity assays. The blocking effects of anti-intercellular adhesion molecule-1 (ICAM-1) and anti-lymphocyte function-associated antigen-1 (LFA-1) monoclonal antibodies (Mabs) were also studied. RESULTS All the 5 cervical keratinocytes were susceptible to LAK, but not to NK. The sensitivity varied among the cell lines. LAK had better killing effects on HSIL than on LSIL. Pretreatment of target cells with IFNγ and TNFα increased the killing mediated by LAK, but had little effect on NK activity. Anti-ICAM-1 and anti-LFA-1 Mabs inhibited LAK-mediated cytotoxicity. CONCLUSIONS All the HPV infected keratinocytes used in the experiments are NK-resistant and LAK-sensitive cells. IL-2, IFNγ and TNFα play some critical roles in the regulation of the susceptibility of cervical keratinocytes, especially HSIL to LAK-mediated cytotoxicity in vitro.

OBJECTIVE To determine whether mutation of the coding or junction region of glucokinase gene (GCK) is also the pathogenic cause of the common form of non-insulin-dependent diabetes mellitus (NIDDM) in Chinese. METHODS Single strand conformation polymorphism (SSCP) analysis was performed after the 12 exons and junction regions of GCK of each subject studied were separately amplified with polymerase chain reaction (PCR). The molecular scanning was carried out in 30 Chinese subjects with common form NIDDM having the age of onset at or before 45 years, and/or with positive family history of diabetes mellitus (NIDDM-A group). Further screening of the mutation/variation found was conducted in 56 NIDDM subjects (NIDDM-B group) and 134 non-diabetes subjects (ND group) in order to define their frequencies. RESULTS No mutation was found by molecular scanning in coding or junction region of GCK in NIDDM-A group. A variant of intron I b was detected in GCK of NIDDM subjects, especially in those with early age of onset and/or with positive family history of diabetes. Significant difference in incidences was found between ND group and NIDDM-A+B group (0% vs 4.7%, Fisher exact P=0.022). CONCLUSIONS (1) Mutation of coding and junction regions of GCK is not the main pathogenic factor of common form NIDDM in Chinese subjects. (2) A variant of GCK intron I b may be found in NIDDM in Chinese, especially in those with early age of onset and/or with positive family history of diabetes. Its role in the expression of GCK remain to be elucidated.

OBJECTIVE To observe changes in the content of myocardial angiotensin Ⅱ and its role in cardiac dysfunction of rat during septic shock. METHODS Septic shock model was produced by cecal ligation and puncture (CLP) operation on rats. Experimental rats were given captopril 15 mg·kg-1/d per os for 3 days before CLP operation. Mean blood pressure and left ventricular pressure were recorded. Myocardial angiotensin converting enzyme (ACE) activities were determined by a fluorometric assay and myocardial angiotensin Ⅱ content was measured by radioimmunoassay. Highly purified membrane of sarcoplasmic reticulum (SR) was prepared from rat hearts. Assays were made of ATP-dependent Ca2+ uptake by cardiac SR and (3H) ryanodine binding to SR. RESULTS Myocardial angiotensin Ⅱ content increased by 51.5% (P<0.01) at the 18th hour post CLP, meanwhile there was a decrease in left ventricular ± dp/dtmax value and the impairment in Ca2+ uptake and (3H) ryanodine binding to cardiac SR. Preliminary administration of captopril reduced myocardial ACE activity and angiotensin Ⅱ content, but increased left ventricular ± dp/dtmax value. In comparison to shock group, the initial rate and the capacity of SR Ca2+ uptake were increased by 120% (P<0.01) and 33.9% (P<0.05), the Bmax value of (3H) ryanodine binding to SR was also elevated, while the Kd value remained unchanged. CONCLUSIONS The elevated intracardiac angiotensin Ⅱ, resulting from the activation of myocardial ACE during sepsis, probably serves as one of the important mediators participating in the pathogenesis of heart failure: the effects of angiotensin Ⅱ may be associated with the disturbance of Ca2+ transport function of cardiac SR.

OBJECTIVE To study the effect of extended parietal cell vagotomy (EPCV) on long-term nutritional status and digestive-absorption function. PATIENTS AND METHODS Thirty-six patients undergoing EPCV were compared with 30 patients with subtotal gastrectomy (SG) 7-14 years after operation. The patients were evaluated in terms of nutritional status, gastric secretion, gastrointestinal motility, and intestinal digestive-absorption function. RESULTS The nutritional status was generally less satisfactory in 33.3% patients with anemia after SG and body weight decreased in 54%. The patients after EPCV were all in good nutritional status, and had no symptoms of anemia; 56% of them had body weight increased by more than 3 kg. The mean basal acid output (BAO), maximal acid output (MAO), and peak acid output (PAO) of the EPCV group were significantly reduced after operation (P<0.01), and moderately reduced as compared with those of the control group (P>0.05). But the BAO, MAO, and PAO of the SG group were more markedly reduced than those of the control group (P<0.001) before operation. Vitamin B12, folacin, intrinsic factor and iron protein level of serum in the EPCV group were slightly decreased as compared with those of the control group (P>0.05), but more significantly decreased in the SG group than in the control group (P<0.001). Iron protein and intrinsic factor level was lower than the normal level. The gastric emptying time and small intestinal passthrough time of EPCV were more close to the normal physiological status, but in the SG group, they were significantly fast (P<0.001). The results of intestinal D-xylose absorption test in EPCV and SG groups were similar (P>0.05). CONCLUSIONS EPCV is capable of preserving gastric acid of physiologic level and normal digestion-absorption function. The effect of EPCV on long-term nutrition and digestion absorption function was extremely milder than that of SG. Therefore, a theoretical basis is provided for the rationality of EPCV.