1990年 · 第103卷第12期

It was found that modified pulse induction could produce SOS responses of the sfi gene in 15 minutes. The responses peaked at 30-60 minutes and were twice as strong as those by persistent induction. The modified pulse induction could therefore more truly reflect the inducing effect. However, the SOS-inducing kinetics of MMC and 4NQO was not identical suggesting distinct kinetic patterns of induction by different mutagens. A suppressive effect on 4NQO-induced SOS response by cinnamic aldehyde and diallyl trisulfate was also observed. The effect might be due to an interference with the metabolic activation of 4NQO or breakdown of 4NQO by the bacteria.

In 22 of 27 cases of congestive heart failure (CHF) treated with nifedipine (NIF), significant improvements in resting hemodynamics were noticed. The higher the basal systemic vascular resistance (SVR) and pulmonary artery end diastolic pressure (PAEDP), the greater the magnitude of reduction was achieved (r=0.84 and 0.77, P less than 0.01, respectively). Exercise hemodynamic investigation showed that NIF lowered SVR, PAEDP and pulmonary vascular resistance (PVR), with an increase in stroke volume (SV) at the serum concentration of 5-10 ng/ml. Maximum effect was observed at the concentration of 20 ng/ml. No further vasodilation was attainable with serum concentrations above 20 ng/ml. No remarkable deviation of NIF pharmacokinetic parameters from the normal ranges was found in CHF patients. The plasma norepinephrine level decreased markedly 2 and 7 hours after the use of NIF. It is concluded that oral NIF is beneficial to severe CHF patients with low cardiac output and high SVR.

For assessing the relationship between the left ventricular (LV) wall motion abnormalities and the status of residual flow to the infarcted region, the extent of coronary artery disease and one-year outcome, 60 patients with a first transmural, Q-wave myocardial infarction (MI) underwent serial echocardiographic examinations. The abnormal wall motion (AWM) score was calculated, and the cardiac events (death, reinfarction, severe ventricular arrhythmia or congestive heart failure) after discharge were recorded. The AWM score of the infarcted area was higher in patients with total occlusion than in those with subtotal occlusion (anterior MI: 14.6±2.4 vs 7.2±2.1; inferior MI: 9.7±2.1 vs 5.1 ±1.2, all P less than 0.01). Regional wall motion of the noninfarcted area was preserved in patients with single vessel disease but decreased in those with multivessel disease. In patients who developed cardiac events in follow-up period a higher AWM (16.4±3.7) was found than in those who did not (8.9±3.1, P less than 0.05). A score of greater than 13 had a strong prediction of cardiac events after acute MI, with a sensitivity of 81%, specificity of 94% and positive predictive accuracy of 88%.

DNA content and nuclear area were measured by microspectrophotometry in gastric carcinogenesis of three adult wolfdogs induced by N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG). The mean values and standard deviations of DNA content and nuclear area in normal gastric mucosa were 10.03±2.30 AU and 28.76±5.85/μm2; those in atrophic gastritis were 12.04±3.34 AU and 28.69±8.02/μm2; in mild dysplasia 13.52±3.73 AU and 28.23±8.12/μm2; in moderate dysplasia 20.88±4.57 AU and 47.58±10.74/μm2; in severe dysplasia 24.01±4.48 AU and 56.64±12.53/μm2; in well-differentiated adenocarcinoma 33.07±9.38 AU and 72.99±15.57/microns. These figures were different (P less than 0.01). The nuclear area of gastric carcinoma increased with DNA content (r=0.73, P less than 0.01). The distribution patterns of DNA content in the histogram showed that diploidy was decreased and polyploidy increased in cancer cells. These findings indicate that DNA ploidy patterns and nuclear area can be useful indices for differentiating carcinoma from precancerous lesions.

The toxicity of combined use of blood schizontocide pyronaridine (PND) and primaquine (PQ) in mice and rats was significantly lower than that of chloroquine (CQ) plus primaquine (PQ). PND 1/2 LD50 (ca 600 mg/kg) in combination with PQ reduced the toxic action of PQ in mice, while CQ 1/2 LD50 (ca 300 mg/kg) plus PQ produced synergistic toxic effect. In animal models such as Plasmodium yoelii sporozoite infection in mice and P. cynomolgi sporozoite infection in rhesus monkeys, the tissue schizontocidal action of PQ was not affected by PND. Therefore, clinical evaluation of PND/PQ in comparison with CQ/PQ in treating vivax malaria is suggested.

The changes of humoral substances in the blood of cirrhotic rats were studied together with their effects on portal hemodynamics at different stages during the development of cirrhosis. The profiles of humoral substances and hemodynamics in two different cirrhotic rat models were also investigated. During the development of cirrhosis, glucagon increased markedly in all stages, histamine and vasoactive intestinal polypeptide (VIP) increased in the early stage, serotonin (5-HT) and somatostatin (SS) increased in the middle and late stages. There were different patterns of humoral substances in different cirrhotic models. Glucagon was the main humoral substance elevated in CCL4 induced cirrhosis, but histamine and 5-HT were mainly elevated in the blood in thioacetamide (TAA) induced cirrhosis. The hemodynamics altered differently in different stages during the development of cirrhosis and differently in the two cirrhotic rat models. Exchange transfusions between normal and cirrhotic rats resulted in an elevation of portal flow in normal rats, but no such changes were found after exchange pressure and an increase of portal blood transfusions between normal rats. The relationship between the humoral substances and portal hemodynamics is discussed. The results of this study strongly support the hypothesis of "humoral mechanism" in the pathogenesis of portal hypertension due to cirrhosis.

Intraoperative coronary venography was performed in 24 patients before and after portal-azygos disconnection for portal hypertension. Before the procedure the portal vein was found to be communicated with cardial and esophageal veins by two pathways, i,e., from the esophageal and gastric branches of the coronary vein to the esophageal varices, with the latter branches by way of the gastric intramural venula. The portal blood flow was postulated to be hepatofugal because the portal trunk could not be seen venographically. Coronary venography done after the disconnection revealed no pericardial and esophageal varices and the portal vein with hepatopetal blood flow. We conclude that the operation had the advantage of complete disconnection between the portal vein and the cardio-esophageal varices, thus preventing the bleeding from the varix and increasing hepatopetal blood flow.

Although the results of limited side-to-side portacaval shunt were better than those of other shunts, postoperative encephalopathy still occurred in 10.2% of the patients. To determine the relationship between the diameter of anastomotic stoma and the development of postoperative encephalopathy, animal experiments and clinical observations were carried out. In 4 of 8 dogs in 3 months after limited side-to-side portacaval shunt and in 6 patients with postoperative encephalopathy, there was significant augmentation of the diameter of anastomotic stoma. To prevent the widening of anastomotic stoma caused by blood flow under high pressure, a limiting ring of 10 mm in diameter was put around the anastomotic site during operation in 21 patients with portal hypertension. Follow-up for 3-15 months (average 6 months) showed that there was no evidence of postoperative encephalopathy and rebleeding. A ring of same kind was put around the dilated anastomotic stoma during exploration in the 6 patients, and all their cerebral symptoms and signs disappeared completely soon after the second operation.

Complications of gastric mucosal bleeding and ectopic embolism occurred in gastric coronary embolization under direct vision in treating hemorrhage from ruptured esophageal varices though it has been widely used with satisfactory results. 40 patients with portal hypertension were treated by splenectomy and gastric coronary vein embolization under direct vision in this hospital. On the basis of Liu's operative method, 20 of the 40 patients underwent controlled embolization of the gastric coronary vein with satisfactory results. The technic not only occluded the predicted bleeding sites of the veins at the esophageal and gastric fundic regions but also blocked its communication with surrounding veins. Thus serious complications were reduced or prevented. The effectiveness of devascularization derived from the technic in question, the detailed maneuver of the procedure, and prevention of complications are discussed.

A long-term follow-up study of 21 patients with 24 attacks of acute non-Q-wave myocardial infarction admitted to Beijing Hospital was carried out and clinicopathological correlation was made in 9 by autopsy. The results revealed that in patients with non-Q-wave myocardial infarction the mortality rate in acute stage was 14.3%, the 2-year aggregate mortality rate 33.3% and the rate of reinfarction 38%, while in patients with Q-wave myocardial infarction admitted in the same period the rate was 18.9%, 26.2% and 17.3%, respectively. It was thus shown that non-Q-wave myocardial infarction was an unstable condition. Although its prognosis in the acute stage was slightly better than that of Q-wave myocardial infarction, yet its outcome in the long run was poorer. Clinicopathological correlation showed that the diagnostic criteria for acute non-Q-wave myocardial infarction used at present are practical and a negative serum enzyme does not preclude the possibility of this disease.