[Effects of indomethacin on 45Ca uptake and membrane fluidity of mitochondria and microsomes from rat liver]

We have reported previously that indomethacin-pretreatment could induce marked hepatic protection in rats. The present work reported effects of indomethacin on calcium regulation and membrane fluidity of mitochondria and microsomes of hepatocytes. The results showed that calcium uptake and membrane fluidity increased significantly in mitochondria and microsomes of hepatocytes isolated from the rats pretreated with indomethacin in vivo as compared with that from the control; adding indomethacin directly to isolated mitochondria and microsomes from normal rats in vitro, on the contrary, decreased membrane fluidity. These changes may be related to the protective effect of indomethacin.

Immunoglobulin G subclasses in serum and circulating immune complexes in patients with Kawasaki syndrome

IgG subclass concentrations in sera of 17 patients with Kawasaki syndrome were determined. Significantly increased IgG1 (P less than 0.001) and IgG3 (P less than 0.001) were found in the patients compared with 22 age-matched healthy children, whereas IgG2 and IgG4 were normal or slightly decreased. IgG immune complexes were measured by protein A-enzyme-linked immunosorbent assay (ELISA) combined polyethylene glycol precipitations. Eight of 17 patients (47.1%) were found to have circulating immune complexes (CIC) values above the normal control range (geometric mean +2 SD). IgG subclass composition in CIC was analyzed. The subclasses in CIC were predominantly IgG1 and IgG3. Because the antibody responses to different antigens exhibit IgG subclass restriction, it would suggest that the change of serum and CIC IgG subclasses in Kawasaki syndrome may have relevance to the pathogenesis of the disease.

Dose-dependent emergence of preneoplastic foci in rat livers after exposure to 2-nitropropane

Male and female Sprague-Dawley rats, 4-6 days old were exposed for 3 weeks (6 h/day, 5 days/week) to 2-nitropropane vapours of 0, 25, 40, 50, 80 and 125 ppm. One week later polychlorinated biphenyls (Clophen A50, 10 mg/kg body weight) were administered for promotion twice a week for 8 weeks. Thirteen weeks after starting the experiments the logarithms of the numbers of preneoplastic liver foci deficient in adenosine-5'-triphosphatase were found to be linearly related to the exposure concentrations of 2-nitropropane. Male rats exhibited an approximately four times lower foci incidence than females.

[Observing cytoprotection of indomethacin on primary cultured hepatocytes of rats]

We observed previously that indomethacin induced hepatic protection against CCl4 and galactosamine in rats. In this work we further investigated this phenomenon on primary cultured rat hepatocytes. The results showed that cultured hepatocytes of rats pretreated with indomethacin in vivo still retained the ability resisting CCl4-induced cytotoxicity, as indicated by lower leakage of enzymes. However, cultured hepatocytes of normal rats treated with indomethacin in vitro had no obvious resistance to CCl4-induced cytotoxicity. The results suggest that indomethacin pretreatment in vivo enables hepatocytes to resist injury, which probably also needs participation of other factors.

Hemodynamic changes during acute pancreatitis and the dopamine therapy

A dog model was used to measure the hemodynamic changes in acute pancreatitis (AP) caused by intraductal injection of fresh trypsin-bile mixture and to investigate the efficacy of dopamine in the treatment of AP. Dopamine was administered intravenously for 3 hours at a dose of 0.6 mg/kg/hour starting 10 min after the induction of AP. Hemorrhagic pancreatitis was characterized by a fall in cardiac output (CO), systemic arterial pressure (SAP), an increase in pulmonary vascular resistance (PVR), systemic vascular resistance (SVR) and the development of early reduction of pancreatic blood flow (PBF). Administration of dopamine produced a significant increase in PBF and leads to a normalization in CO, SAP, PVR and SVR. In addition, dopamine significantly reduced the severity of the AP, as assessed by histological staging and mortality rate. These results suggest that dopamine can limit the progression from edematous to hemorrhagic pancreatitis and prevent irreversible pancreatic damage through preserving PBF at the early phase of AP.

[Von Willebrand factor in acute leukemia]

Using Laurell's rocket and crossed immunoelectrophoresis, we studied the function of vWF on the basis of its quantity and quality. The ristocetin-induced platelet aggregation was also investigated. The results revealed that the level of plasma vWF:Ag in acute leukemia (88.53 +/- 46.33%) was significantly higher than that in normal controls (90.53 +/- 29.54%) (P less than 0.01) and markedly decreased as these cases were in partial or complete remission (105.29 +/- 26.65%) (P less than 0.01), but there were no significant differences between the cases with (204.76 +/- 68.17%) and those without bleeding tendency (174.77 +/- 65.78%), nor between ALL (185.22 +/- 62.19%) and ANLL (192.43 +/- 77.97%) (P greater than 0.05). Compared with normal controls, crossed immunoelectrophoresis of plasma vWF in 21 cases showed a rapid migration of the precipitin arcs toward the positive pole in 16 cases. This indicates that there is a relatively increased amount of small multimers in the plasma, which do not have the active function of vWF so that the ristocetin-induced aggregation was reduced or even absent in those 21 cases (the maximum aggregation rate was 62.89 +/- 34.02% in the patients and 104.69 +/- 12.13% in normal controls (P less than 0.01). The possible mechanism and clinical significance of these changes are discussed.

Superoxide dismutase: fluctuations in the structure and solvation of the active site channel studied by molecular dynamics simulation

The molecular dynamics (MD) simulation of superoxide dismutase (SOD) in water is carried out for a total of 23 ps. The simulation system is a 26 A sphere centered at the active site of SOD, including 1602 atoms from SOD and 1761 water molecules. There is no gross deviation from the x-ray structure for the average MD structure. The structure and potential fluctuations around the active site are examined. The results provide new insight to the interactions between SOD and its substrate superoxide.

Mesencephalic dopamine neurons become less sensitive to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity during development in vitro

The in vitro development of monoamine oxidase (MAO) activity and [3H]dopamine (DA) uptake capacity of dissociated cell cultures from rat embryo mesencephalon were correlated with the potency of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 1-methyl-4-phenylpyridine (MPP+) neurotoxicity. Specific activities of both MAO-A and MAO-B increased during in vitro development of the cultures, with MAO-B activity increasing 20-fold between the first and fourth week. Similarly, [3H]DA accumulation increased 2.6-fold between the first and third week in vitro, when it reached a plateau. Unexpectedly, the toxicities of MPTP and MPP+ were substantially decreased in the older cultures. Exposure to MPTP reduced [3H]DA accumulation per culture by 77% in 1-week-old cultures and by 36% in 4-week-old cultures. Similarly, damage caused by MPPT was reduced from 84% of control in the first week to 34% of control in the fourth week. The attenuation of neurotoxicity was not due to an increase in storage of MPP+ in the synaptic vesicles of DA neurons, nor to a change in the distribution of MPP+ between dopaminergic and other cellular components of the cultures. The damage to DA neurons caused by the mitochondrial toxin, rotenone, also showed a similar reduction in the older cultures. These observations coupled with an increase in lactate formation and glucose consumption during the in vitro development of the cultures suggest a shift toward increased glycolysis and decreased dependence on aerobic metabolism. This would render the cells more resistant to the inhibition of mitochondrial function by MPP+.

[Hemodynamic effects of naloxone in early acute pancreatitis in the dog and its efficacy in treating acute pancreatitis]

Naloxone, an opiate receptor blocker, has been shown in earlier studies to have positive effect on cardiovascular function in a variety of diseases in which the secretion of endogenous opioid peptides was suspected. In this communication, a dog model of acute pancreatitis (AP) was made by intraductal injection of fresh trypsin-bile mixture, in which the hemodynamic changes were measured, the therapeutic efficacy of naloxone was evaluated. Pancreatitis was characterized by a fall in SAP, CO, dp/dt, an increase in PVR, SVR and the early reduction of pancreatic blood flow (QP). Administration of naloxone produced a significant increase in QP and led to normalization in SAP, CO, dp/dt, PVR and, SVR. In addition, Naloxone significantly reduced the severity and mortality of AP. These results suggest that naloxone appears to limit the progression from edematous to hemorrhagic pancreatitis through preserving QP at the early phase of AP. We propose the hypothesis that endogenous opiates may play a role in the pathophysiology of AP.

Treatment of stage I endometrial carcinoma

Cases of stage I endometrial carcinoma treated at Columbia-Presbyterian Medical Center, New York, between 1966 and 1980 were evaluated with regard to clinical parameters, surgicopathologic findings, treatment modalities and survival. Four factors significantly influenced survival: tumor grade, patient's age, uterine size and addition of postoperative external radiotherapy in cases of significant myometrial invasion or a poorly differentiated lesion. No deaths or significant morbidity resulted from the use of adjuvant whole pelvic radiation.

[Value of colonoscopy in postoperative care of colorectal carcinoma]

From 1981 to 1986, fiberoptic colonoscopy was performed in 2225 patients, of whom 356 cases (16%) were operated on for colorectal carcinoma and followed up for three months to twenty years. 27 cases were detected to have a second primary cancer and 1 case third primary cancer. In addition, 1 case of carcinoid, 6 cases of in-situ cancers, and 77 cases of adenomas were found. Among the 138 asymptomatic cases, 8 were proved to have a second cancer and 6 to be in early stage. Among the remaining 218 symptomatic cases, 26 with second cancers and 10 in the early stage were detected. The study shows that periodic colonoscopic examinations are mandatory for asymptomatic postoperative patients.

Factors associated with the decline of the Cooperative Medical System and barefoot doctors in rural China

The Cooperative Medical System (CMS) and its barefoot doctors have been in decline in rural China for nearly a decade. In order to explore the reasons for this, in 1987 we carried out a survey of villagers, barefoot doctors, and local administrators in Fengxian, Shanggoa, and Loaan counties, where incomes are good, fair, and low, respectively. The state of the CMS in these counties was contrasted and the situations which prevailed in 1978, 1982, and 1985, when the system was, respectively, at its peak, had begun to decline, and had declined markedly, were compared. A random sample of villages was selected and all the barefoot doctors and administrators as well as a random sample of households were surveyed. The results indicate that health status (as measured by infant mortality, immunization coverage, and rate of infectious diseases) has decreased in areas where the CMS has declined, while per capita incomes increased. Concomitantly, villager's expenditures on health care have increased. Barefoot doctors and their patients were, however, reasonably happy with the system, and in its absence the doctors are no longer able to obtain ongoing training. The CMS was fiscally sound, and did not decline to the same extent in all areas--it continues to thrive in Fengxian, which is relatively affluent. It is concluded that the system probably declined because many local administrators perceived that it no longer enjoyed the backing of the central government.