[Protective effects of berberine on spontaneous ventricular fibrillation in dogs after myocardial infarction]

The effects of berberine (Ber 5 mg/kg iv) on ventricular tachyarrhythmias and electrophysiologic consequences in both normal and ischemic myocardium were studied in the open-chest dogs subjected to programmed electrical stimulation (PES) and intimal surface anodal direct current stimulation of the circumflex coronary artery on 5-8 d after acute myocardial infarction. Its effects were compared with procainamide (PA). Both drugs distinctly lengthened the QTc interval and the effective refractory period (ERP) of normal and infarct myocardium in both ventricles and decreased the dispersion of ERP in infarct myocardium (IDR) as well as the dispersion of ERP in left ventricle (VDR). The PES-induced ventricular tachycardia (VT) or ventricular fibrillation (VF) was prevented in 4 out of 6 Ber treated and 5 out of 6 PA treated dogs. Ber prevented spontaneous VF in 4 dogs (n = 5). PA prevented spontaneous VF in 3 dogs (n = 5). Normal saline (NS) did not prevent PES-induced VT/VF and spontaneous VF. The results suggest that Ber may be effective in preventing the onset of reentrant ventricular tachyarrhythmias and sudden coronary death after myocardial ischemic damage.

[Screening of strains producing extracellular catechol 1,2-dioxygenase and fermentation conditions]

Two strains of Pseudomonus sp. having the extracellular catechol 1, 2-dioxygenase activity were selected from 112 bacterial strains. The conditions for enzyme production of the strains were examined. The optimal temperature and pH for enzyme formation were 30 degrees C and pH 6.8-7.0 respectively. Enzyme formation was enhanced by sodium benzoate, and was markedly inhibited by glucose, maltose and glycerol. Ammoniacal nitrogen sources were essential for cell growth and enzyme production. Sodium succinate was an effective inducer for enzyme formation. When the organism was grown in 0.15% sodium benzoate medium (pH 6.8-7.0) at 30 degrees C for 72 hours, about 10 units of catechol 1,2 dioxygenase per ml was obtained.

Fluorescence and Delayed Light Emission from Mesophyll and Bundle Sheath Cells in Leaves of Normal and Salt-Treated Panicum miliaceum

A modified fluorescence microscope system was used to measure chlorophyll fluorescence and delayed light emission from mesophyll and bundle sheath cells in situ in fresh-cut sections from leaves of Panicum miliaceum L. The fluorescence rise in 3-(3,4-dichlorophenyl)-1, 1-dimethylurea (DCMU)-treated leaves and the slow fluorescence kinetics in untreated leaves show that mesophyll chloroplasts have larger photosystem II unit sizes than do bundle sheath chloroplasts. The larger photosystem II units imply more efficient noncyclic electron transport in mesophyll chloroplasts. Quenching of slow fluorescence also differs between the cell types with mesophyll chloroplasts showing complex kinetics and bundle sheath chloroplasts showing a relatively simple decline. Properties of the photosynthetic system were also investigated in leaves from plants grown in soil containing elevated NaCl levels. As judged by changes in both fluorescence kinetics in DCMU-treated leaves and delayed light emission in leaves not exposed to DCMU, salinity altered photosystem II in bundle sheath cells but not in mesophyll cells. This result may indicate different ionic distributions in the two cell types or, alternatively, different responses of the two chloroplast types to environmental change.

Studies of beta-thalassemia mutations in families living in three provinces in southern China

beta-Thalassemia is a common disease in Southern China and 10 different mutations or frameshifts are responsible for most types of beta-thalassemia in this area. We studied 126 chromosomes of 80 beta-thalassemia patients from the Guangxi, Guangdong, and Sichuan Provinces using the polymerase chain reaction followed by dot-blot hybridization with specific oligonucleotide probes. The most common mutation in the three provinces is the frameshift at codons 41-42, followed by the A----T mutation at codon 17. The A----G mutation at nt -29 of the promoter is common in Sichuan but not in the other two provinces. Three mutations (T----C at nt -30; G----T at IVS-I-1, and G----C at IVS-I-5) were not observed. These data were used to initiate a prenatal diagnosis program using the same techniques for identification. Eleven fetuses at risk for beta-thalassemia have been diagnosed.

Cisapride in gastro-oesophageal reflux disease: effects on oesophageal motility and intra-oesophageal pH

Since gastro-oesophageal reflux disease is due to disturbances of oesophageal motility, motor and pH measurements are an important means to test a new anti-reflux drug, cisapride. In oesophageal manometry cisapride increased the pressure of the lower oesophageal sphincter in healthy volunteers and patients, and in the majority of studies it also strengthened the amplitude of oesophageal contractions. Cisapride lowered the total duration of acid exposure in the lower oesophagus in both volunteers and reflux patients. Thus cisapride may be useful in the treatment of gastro-oesophageal reflux disease.

[Immunohistochemical study of alpha-1-antichymotrypsin and GFAP in glioma]

GFAP is a specific antigen of glial element, but Alpha-1-antichymotrypsin has not been reported in the literature Alpha-1-antichymotrypsin was guided by GFAP using PAP method to the astrocytes of 137 gliomas. 120 (87%) gliomas were positive for Alpha-1-antichymotrypsin. Of these 120 gliomas, 86 (72%) gave diffuse distribution, 17 (14%) gave focal distribution, and 17 (14%) gave scattered distributions. Alpha-1-antichymotrypsin in glioma tissue may be an important tumor marker for diagnosis.

Absence of Variable Fluorescence from Guard Cell Chloroplasts of Stenotaphrum secundatum

The lack of detectable variable fluorescence from guard cell chloroplasts in both the albino and green portions of variegated leaves of St. Augustine grass (Stenotaphrum secundatum var variegatum A.S. Hitchc.) is reported. Fluorescence was measured either with a highly sensitive, modified fluorescence microscope which was capable of recording fluorescence induction curves from single chloroplasts, or with a spectrofluorometer. Both fast and slow fluorescence transients from S. secundatum guard cells showed a rapid rise and then remained at a steady level. Neither variable fluorescence increase (induction) nor decrease (quenching), properties normally associated with photosystem II, was observed from these chloroplasts. These fluorescence kinetics did not change either with alterations of the specimen preparation procedure or with alterations of the excitation light intensities and wavelengths. These results indicate that guard cell chloroplasts in this variety of S. secundatum do not conduct normal photosystem II electron transport. Light regulation of stomatal conductance in intact leaves of this plant did occur, however, and was similar to light regulation observed in other species. The conductance of the green portion of the leaves was much greater in the light than in the dark, and was much greater than the conductance of the albino portion of the leaves. Stomata in the green portion of the leaves also showed greater opening in blue light than in red light. These results provide evidence that stomatal regulation in this variety of S. secundatum does not rely on photosystem II electron transport in guard cell chloroplasts.