Action of bradykinin at the cyclooxygenase step in prostanoid synthesis through the arachidonic acid cascade

Bradykinin enhances prostanoid synthesis in aorta smooth muscle cells. Free arachidonic acid also enhances prostanoid synthesis and bradykinin, unlike fatty acid releasing agents, has a synergistic effect with free arachidonic acid. Bradykinin promotes metabolite release from cells prelabeled with [14C]-arachidonic acid and this effect is blocked completely by indomethacin. High performance liquid chromatography shows increase amounts of labeled 6-keto-prostaglandin F1 alpha, prostaglandin E2 and three additional cyclooxygenase-dependent metabolites but no increase in free arachidonic acid or other metabolites either in the absence or presence of indomethacin. Fatty acid releasing agents such as A23187 and cyclosporine A have very different effects on cells. These agents enhance levels of prostanoids, a number of other cyclooxygenase-independent metabolites, and free arachidonic acid which is even more elevated with added indomethacin. Bradykinin behaves in all respects like another agent, bacterial lipopolysaccharide, and the action of both agents is consistent with a mechanism involving cyclooxygenase rather than fatty release in the arachidonic acid cascade.

[The effect of plaque fluid on demineralization of enamel powder]

The aim of this study was to explore any substance in dental plaque which might affect the demineralization of enamel. Plaque fluid was prepared by centrifugation of pooled plaque from 56 young adults without periodontal diseases. Enamel was separated from healthy teeth of adolescents and crushed into powder. The enamel powder was treated separately by plaque fluid and synthetic plaque fluid (as a control, with similar calcium, fluoride content and pH as the natural). After this, the enamel powder was washed with PBS. Both the plaque fluid-treated and synthetic plaque fluid-treated enamel powder were demineralized by mixed organic acid (pH 4.5). The calcium content in both plaque fluids, PBS and organic acid after treatment with enamel powder was analysed by atomic absorption spectrophotometer. The results showed that there was no promoting effect in plaque fluid on demineralization of enamel, but, on the other hand, some protecting action was observed which might contribute to the presence of proteins in plaque fluid.

Effects of fat on insulin-stimulated carbohydrate metabolism in normal men

We have examined the onset and duration of the inhibitory effect of an intravenous infusion of lipid/heparin on total body carbohydrate and fat oxidation (by indirect calorimetry) and on glucose disappearance (with 6,6 D2-glucose and gas chromatography-mass spectrometry) in healthy men during euglycemic hyperinsulinemia. Glycogen synthase activity and concentrations of acetyl-CoA, free CoA-SH, citrate, and glucose-6-phosphate were measured in muscle biopsies obtained before and after insulin/lipid and insulin/saline infusions. Lipid increased insulin-inhibited fat oxidation (+40%) and decreased insulin-stimulated carbohydrate oxidation (-63%) within 1 h. These changes were associated with an increase (+489%) in the muscle acetyl-CoA/free CoA-SH ratio. Glucose disappearance did not decrease until 2-4 h later (-55%). This decrease was associated with a decrease in muscle glycogen synthase fractional velocity (-82%). The muscle content of citrate and glucose-6-phosphate did not change. We concluded that, during hyperinsulinemia, lipid promptly replaced carbohydrate as fuel for oxidation in muscle and hours later inhibited glucose uptake, presumably by interfering with muscle glycogen formation.

The role of oxygen free radicals in myocardial ischemia/reperfusion injury

A series of experiments have been done to investigate the role of oxygen free radicals in ischemia/reperfusion injury. The following results were found: Myocardial MDA content increased significantly after post-ischemic reperfusion in vivo and in vitro. A blockade of the xanthine oxidase pathway for free radical generation could provide effective protection against ischemia/reperfusion injury. Exogenous reactive oxygen intermediates H2O2, .OH and O2- could induce changes in the contractility and electrophysiological properties of myocardial cells similar to those seen in ischemia/reperfusion. An outburst of free radical generation was detected by ESR spectroscopy at low temperature (-173 degrees C) and with the spin trapping technique during the very early phase of reperfusion. The authors emphasize the important role of free radicals in the pathogenesis of myocardial ischemia/reperfusion injury.

Effects of enflurane on inducibility of ventricular tachycardia

The effects of enflurane on cardiac electrophysiologic parameters and on inducibility of ventricular tachycardia (VT) by programmed stimulation were studied in 12 patients (11 men, 1 woman, mean age +/- standard deviation 55 +/- 8 years) with drug refractory sustained monomorphic VT who underwent transcatheter ablation with high-energy direct-current shocks. One catheter ablation procedure was performed in 10 patients, whereas 2 ablation sessions were necessary in 2 patients. Programmed ventricular stimulation was performed on 2 separate days (mean interval 19). There were 2 baseline studies, 1 several days before ("baseline study I") and the second at the beginning of the ablation procedure ("baseline study II") while the patient was awake and nonsedated. The third programmed stimulation study was done 15 to 30 minutes after administration of anesthesia with enflurane, oxygen and nitrous oxide ("enflurane study"). Rate of sinus rhythm, QRS duration, PQ interval and ventricular effective refractory period were unaltered, whereas QTc interval increased significantly after initiation of anesthesia. Before and after induction of general anesthesia, clinical VT was inducible in all patients. However, in 1 patient, induction of VT was only possible by pacing in the left ventricle after enflurane administration. Based on these data, it is concluded that general anesthesia with enflurane, oxygen and nitrous oxide has no marked influence on inducibility of clinical VTs. Therefore, this type of anesthesia may be useful for nonpharmacologic, ablative procedures requiring general anesthesia.

Effect of free radicals on pulmonary vascular response to acetylcholine

We describe a model of pulmonary endothelial injury caused by electrolysis-generated free radicals. Rabbit lungs were perfused in situ with Krebs solution at 37 degrees C containing 30 microM indomethacin. Electrolysis of this solution for 2 min, with a constant DC current of 20 mA, caused pulmonary vasoconstriction during the passage of current and converted subsequent acetylcholine-induced vasodilation to vasoconstriction. Electrolysis also inhibited endothelial-dependent vasodilation due to the calcium ionophore A23187 but not that due to sodium nitroprusside, suggesting that smooth muscle function was unaltered, while that of the endothelium of the lung is specifically modified by the stimulus. These effects were prevented by a mixture of superoxide dismutase and catalase or by sodium salicylate, which removes hydroxyl radicals from solution after electrolysis. Electrolysis-induced endothelial damage was less functionally obvious when electrolysis was applied during recirculation of Krebs solution, perhaps because recirculating perfusion may trigger release of either free radical scavengers or other protective substances. This technique offers a simple reproducible model to study free radical-related damage of endothelium in the intact lung.

[A preliminary report of evoked potential marker study of pattern shift visual evoked potentials (PS-VEP) and auditory evoked potentials (AEP) on schizophrenic twins]

This paper reports the result of electroneurophysiological study of the pattern shift visual evoked potentials (PS-VEP) and auditory evoked potentials (AEP) on six pairs of schizophrenic twins. The result indicated that there were significant differences in the inter-pair variance between MZ and DZ in latency P2, amplitude P2-N2 and P2 of using PS-VEP. AEP was also used for this group cases, and the result showed the presence of statistical differences in the inter-pair variance of latency N2, amplitude N1-P2 and P2. The authors speculated upon that the above six electrophysiological markers may be related to genetic factors, which had been proved by the blood group, character, clinical symptoms and treatment response of those patients.

Monitoring of filarial antigens in jirds and patients after treatment

We developed a sandwich ELISA with monoclonal antibodies to monitor filarial antigens in animals and patients after infection and treatment. Levels of antimicrofilarial antibodies and parasite antigens were measured periodically in 40 B. malayi infected jirds. In all animals L3 HC11 antigen was detected earlier than Mf ES34 antigen, while antimicrofilarial antibodies appeared much more slowly. These serologic changes precede the onset of patent infections. After 3 courses of treatment with DEC and M170, the levels of parasite antigen in sera and of Mf in peritoneal cavities were monitored in 23 infected jirds. In 8 jirds Mf became negative, no adult worms were found in 7 jirds and a single degenerating female worm was present in 1 jird. ES34 and HC11 were undetectable in 8/8 and 6/8 necropsy sera. Mf persisted in 11 animals, 9 jirds were necropsied, 8 contained adult worms. Detectable levels of ES34 or HC11 antigen were present in 7/9 and 8/9 from these animals. In sham-treatment, few changes were noted in control animals. Thus, parasitological findings at necropsy are correlated with the results of antigen detection assay. We analyzed serial serum samples from 32 bancroftian microfilaremia collected 1-42 months after DEC therapy. Mf resolved rapidly in all treated individuals. ES34 disappeared faster than HC11, 3 months after treatment. Levels of ES34 and HC11 antigens remained detectable or rising after treatment in 8 and 10 individuals. Four patients' Mf recurred 20-42 months after treatment. These findings show that the remaining or a rise in serum levels of antigen after therapy predicts recurrent microfilaremia in patients and additional treatment is needed.

[Study on the bias axis stress-strain relationship of the human mandible]

This paper presents our study on the bias axis elastic properties of the human mandible. The elastic coefficients were determined by the composite materials mechanical testing methods. From these values the "technical constants" were calculated to be: EL = 18.823GPa, ET = 12.777GPa, GLT = 5.564GPa, vLT = 0.302, vTL = 0.205. Variation of elastic constants of the human mandible with the orientation to its long axis was investigated. A brief description of the variation law is given. The bias axis stress-strain relationship of the human mandible is established. The data indicate that the human mandible is a living, anisotropic and nonhomogeneous composite biomaterial. Its mechanical properties have a close relation to its location, orientation and structure.

[The changes of viscoelastic properties of whole blood in patients with chronic cor pulmonale]

The changes of blood viscoelasticity and apparent viscosities at low shear rate (0.512 S-1) and high shear rate (51.2 S-1) were studied in 61 patients with various severity of chronic cor pulmonale (CCP). The relation between blood viscoelasticity and apparent viscosities and PaO2 and PaCO2 was investigated and the data were collected before and after treatment. Grouped data: Group 1. A total of 61 patients with CCP were studied, 10 of them died during hospitalization. Sixty-one patients at the acute stage were divided into mild, severe and dead sub groups. Twenty-nine patients were improved after treatment. Group 2. Control group (74 normal people) matched group 1 in sex and age. The results demonstrated that eta 0.512, eta 51.2 and eta' were slightly increased in the mild group, but HCT, eta 0.512, eta 51.2, AI, eta' and eta" were elevated more significantly in the severe group. All variables mentioned above of died patients were elevated more remarked than that of the mild group. HCT, eta" in dead patients were slightly higher than those in severe group (P less than 0.05-0.01). It was clear that the more severe the patient, the more increased the hematocrit and RBC aggregation, the less the RBC deformability. HCT would be elevated when PaO2 was below 8 kPa (60 mmHg) and the HCT, eta 0.512, eta', eta" increased significantly (P less than 0.05-0.01) when PaCO2 was over 6.65 kPa (50 mmHg). There was a positive linear correlation between eta 0.512 and PaCO2.(ABSTRACT TRUNCATED AT 250 WORDS)

[Gas chromatograms of fatty acids from Rickettsia and their similarities]

Fatty acid compositions of 7 strains of Rickettsia were analyzed by a on-line GC/MS system. These strains were R. prowazekii E, R. conorii Simko, R. rickettsii R, R. sibirica Barbash and 246, R. sinkiangensis Jinghe, and R. heilungkiangensis 54. The samples were purified by means of the concentrated salt-ether method. There were about 50 peaks in the fatty acid profiles, and 16 of these peaks were determined, i.e. C22:0, C19:0, C18:0, C18:1, C18:2, C17:0, C16:0, C16:1, 3-OH-C14:0, C15:0, C14:0, C13:0, 2-OH-C12:0, C12:0, 2-OH-C10:0, and C11:0. The major fatty acids were the saturated straight chain acids (e.g. C16:0, C18:0, C14:0) and the unsaturated straight chain acids (e.g. C18:1, C18:2, C16:1). Similarities of fatty acid profiles of tested strains were discriminated by the improved Kulik-Vincent method. The result showed that the KV's coefficient of strains Jinghe and 246 was 97.0%, and the KV's coefficient of strains 54 and the others was 81.6-94.6%.

[An experimental study on hepatic arterial embolization with 131I-MMC-GM]

We designed a new gelatin microsphere (GM, 65 micron in diameter), which could combine with mitomycin C and 131I. The test in vitro showed that the GM had excellent drug release effect. Hepatic arterial embolization was carried out in 6 dogs with 131I-MMC-GM. The dogs survived from 4 to 28 days before being killed. Scintigraphy indicated that high radioactivity was concentrated in the liver, but was very low in the blood and thyroid. Pathologic study found that the GM was trapped in hepatic arterioles. The GM was eliminated by foreign body giant cells and the lumen of arterioles was occupied by granulations 14-28 days after operation. 131I-MMC-GM is a multiple anticancer agent which can exert triple action of targeting chemotherapy, internal radiotherapy and arterial embolization.

Myocardial dysfunction and norepinephrine release in the isolated rat heart injured by electrolysis-induced oxygen free radicals

In the present investigation, we used electrolysis as a source of oxygen free radicals to test their possible role in norepinephrine release, as well as in the mechanism of cellular injury, cardiac dysfunction and arrhythmias. In the isolated rat heart perfused under constant pressure, according to the Langendorff technique, electrolysis of the Krebs-Henseleit solution (10 mA d.c. current for 1 min) produced myocardial irreversible dysfunction within 5 min. Fifteen minutes after electrolysis, significant falls in the left ventricular pressure (from 87.5 +/- 6.8 to 33.7 +/- 5.2 mmHg), dP/dt max (from 1230 +/- 90 to 375 +/- 59 mmHg/s), heart rate (from 287 +/- 18 to 119 +/- 13.5 beats/min) and coronary flow (from 14.8 +/- 9 to 3.4 +/- 1.7 ml/min) were observed, along with an increase in left ventricular end diastolic pressure from 10 to 50 +/- 3.5 mmHg (n = 8, P less than 0.01). AV conduction block and/or sinus bradycardia were noted in all preparations. An increase in norepinephrine washout from 298.5 +/- 84 at baseline to 610 +/- 110 pg/min/g 5 min after electrolysis was measured (n = 8, P less than 0.05) and a 44.8 +/- 9.2% and 35 +/- 7.5% reduction, respectively in right and left ventricular tissue norepinephrine content was also found at 30 min (n = 5, P less than 0.05). Pretreatment of the hearts 10 min before electrolysis and throughout the experimental period by superoxide dismutase (SOD; 100 U/ml), catalase (150 U/ml), a combination of SOD + catalase or mannitol (50 mM) partially blocked the deleterious effect of free radicals and permitted a functional recovery of 50 to 60%, mannitol being the more potent protective agent. Furthermore, these scavengers also significantly reduced norepinephrine washout.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of microinjection of tutin into nucleus tractus solitarius region on the morphology of neural tissue of this area in rabbit]

Four hours after unilateral microinjection of tutin (10 micrograms) into the NTS region, the nervous tissue surrounding the center of microinjection showed the following morphologic changes: 1. Under the light microscopic examination (n = 5), the neuronal body showed chromatolysis and the nuclear basophilia enhanced in about 17% of the neurons, the lacunae of neuropil distended and gave a "spongy" appearance. The neurons with lesion mingled with the normal ones in the absence of distinct demarcation. 2. Under the electron microscopic examination (n = 3), the cisterns of rough endoplasmic reticulum distended, and the nuclear electron density increased on account of the increased nuclear chromatin in the affected cells. The organelles of dendrites decreased or disappeared; the neuroglia looked edematous. There were only a few axons which looked edematous in the neuropil. Microinjection of the same volume (1 microliter) of NS into the other side of NTS region in the same rabbit didn't show any sign of damage as those described above. Thus, our preliminary results suggest that tutin might damage the soma and dendrites of some neurons, and therefore, it might be a neuroexcitotoxin.

Hypothyroidism increases serotonin turnover and sympathetic activity in the adult rat

Adult, male Sprague-Dawley rats underwent surgical thyroidectomy (Tx) or sham surgery. In all three experiments from which data are reported, a 3-week recovery period was allowed. In experiments I and II, baseline measurements of colonic temperature (Tc) and urinary norepinephrine excretion (NE) were obtained, and both variables were monitored daily for the duration of the studies. After baseline measurements, half of each surgical group was given either triiodothyronine (T3) or vehicle injections subcutaneously; in experiment I replacements continued for 1.5 days, while in experiment II T3 replacement continued for 3.5 days. Rats were decapitated at the end of each experiment and serotonin (5-HT) turnover was measured in brainstem. Serotonin turnover in rostral and caudal brainstem was increased with Tx (p less than 0.05). Increased turnover in caudal brainstem was normalized by T3 only in experiment II. Similarly, decreased Tc and elevated NE with Tx were normalized in experiment II but not in experiment I. In experiment III, NE measurements normalized on a creatinine excretion basis indicated that increased NE is evident with Tx, irrespective of normalization procedure. Significant correlations between 5-HT in caudal brainstem and metabolic correlates of sympathetic function, concurrent normalization of NE and 5-HT in caudal brainstem, plus work from other laboratories describing sympathoexcitatory serotonergic neurons located in the caudal brainstem suggest that the central and peripheral changes in the hypothyroid rat are causally related.

Basic determinants for FM responses in the inferior colliculus of rats

The response of 835 click-sensitive neurons in the inferior colliculus (IC) to ramp frequency modulated (FM) tones was studied in the anaesthetized rat. More than 70% of the cells were sensitive to the FM sound, and over 25% were "FM specialized". Systematic variations of the stimulus parameters showed that sweep velocity, sweep range, and intensity of the FM signal were the 3 basic determinants for the unit response. For an "FM specialized" cell, the response pattern to each of the parameters was either monotonic or bell-shaped. The population statistics of response patterns to the FM parameters, including the tuning factors, were generated. A stimulus domain was proposed to represent the "receptive space" of the FM cells.

[Interleukin 1 beta gene expression by mouse glomerular mesangial cells]

Interleukin 1 beta (IL-1 beta) plasmid DNA was isolated and purified with alkaline lysis method and equilibrium centrifugation in cesium chloride. IL-1 beta plasmid RNA was cut by restriction endonucleases EcoRI and XbaI, and after that it was 1 loaded in 0.75% low-melting-temperature agarose and underwent electrophoresis. 1.2 Kb DNA fragments were extracted from gel and for further purification it was used as IL-1 beta cDNA probe. RNA from mouse glomerular mesangial cells, tubular epithelial cells and P388D, cells was cut with EcoRI separately and then hybridized in dot blots with alpha 32P labeled IL-1 cDNA probe. The dot blot autoradiograph showed expression of the IL-1 beta gene in mesangial cell and P388D1 cell but showed no expression in epithelium. These results not only identified the specificity of IL-1 beta probe but also suggested that the local production of IL-1 beta may be important in the pathogenesis of glomerulonephritis.

Supercondensed structure of plasmid pBR322 DNA in an Escherichia coli DNA topoisomerase II mutant

An unusual structural component, supercondensed pBR322 DNA, has been found in plasmid pBR322 DNA samples isolated from a DNA topoisomerase II mutant of Escherichia coli, SD108 (topA+, gyrB225). The supercondensed pBR322 DNA moved faster than supercoiled pBR322 DNA as a homogeneous band in agrose gels when the DNA samples were analysed by electrophoresis. The mobility of the supercondensed DNA was not substantially affected by chloroquine intercalation. The supercondensed pBR322 DNA migrated as a high density "third DNA band" when the samples were subjected to caesium chloride/ethidium bromide gradient equilibrium centrifugation. The unusual pBR322 DNA visualized by electron microscopy was a globoid-shaped particle. These observations suggest that the pBR322 plasmid can assume a tertiary structure other than a supercoiled or relaxed structure. DNA topoisomerases may be involved in the supercondensation of plasmid DNA and chromosomal DNA.

[Protective effects of gypenosides on experimental myocardial infarction]

In the model of myocardial infarction produced by occlusion of left anterior descending coronary artery (LAD) in rabbit, gypenosides (GP 100 but not 50 mg/kg, ip) reduced myocardial infarct size and decreased serum free fatty acid (FFA). In rat model of myocardial infarction, GP and the fractions of GP of non ginsenosides (FGNG) both in dose of 100 mg/kg, ip, protected significantly myocardial superoxide dismutase (SOD) activity and decreased the myocardial malondialdehyde (MDA). The results indicate that the protective effect of GP on myocardial infarction may be correlated with its prevention of myocardial lipid peroxidation, and attributed to the amelioration of FFA metabolic deterioration.

[Nutritive physiology of Psoralea corylifolia L]

Our study has shown that P. corylifolia absorbs and accumulates N2 and K2O most speedily in the periods of branching, flowering and fruiting, while P2O5 in the period of full flowering and fruiting. P2O5 is accumulated mainly in the seed and K2O in the stem. The nutriment accumulation is positively correlated with that of dry substances. To produce 100 kg of P. corylifolia an absorption of 10.59 kg of N2, 3.68 kg of P2O5 and 10.21 kg of K2O is needed.

[Acute morphological changes in guinea-pig cochlea following electrical stimulation]

The acute morphological changes of intracochlear electrical stimulation were studied in 42 guinea-pigs, which were divided into six groups. The electrode was implanted into the cochlea 1.5mm deep, and the cochlea was stimulated with intensities of 216 microA, 432 microA, 648 microA, 864 microA and 1080 microA for six hours. Morphological changes observed in the stimulated ears ranged from hair cell, nerve cell and supporting cell degeneration to complete destruction of the basilar membrane and organ of Corti overlying the electrode. These changes occurred at current intensities ranging from 432 to 1080 microA and were conspicuously absent in the implanted but unstimulated control ears and in the ears with 216 microA stimulation. Our observations also demonstrate that 432 microA stimulation can change the structure of the cochlea.

[Effect of seed soaking in plant hormone and trace element fertilizer on the growth of Psoralea corylifolia L]

Our study shows that seed soaking in triacontanol, ammonium molybdate and gibberellin can promote the growth of P. corylifolia, reduce its premature flower and fruit drop, raise the fruit-bearing rate by 6.5-17.4%, and fruit-bearing number by 21.6-28.4%, so as to increase the yield per unit area by 31.5-34.8%. Seed soaking in naphthylacetic acid and boric acid does not give such a marked effect.

[Effects of proteolytic enzymes on demineralization of enamel]

Papain, trypsin and collagenase were used in the experiment for the study of their effects on the demineralization of enamel surface by organic acids in vivo. No effect of any of the enzymes was observed. The use of papain and trypsin in treating tooth surfaces in vitro, no matter whether sodium bisulfite was used, showed no effect on the demineralization of the enamel by mixed organic acids. But, by the analysis of amino acids in the enzyme solutions before and after treating tooth surface, it was shown that some proteinous substances were destroyed. Accordingly, it can be suggested that the enzyme takes no part in the destruction of the inorganic tooth substance.

Control of rat glomerular epithelial cell growth in vitro

The interaction of cultured rat GEC1 with several growth factors was explored in order to obtain a better understanding of in vivo factors which might stimulate GEC proliferation. GEC proliferated in response to EGF but not IGF-1, MSA or PDGF. Specific, saturable receptors for EGF were detected in saturation and competition binding studies utilizing 125I-EGF with an approximate Kd of 1.7 nM and 86,000 binding sites per cell. TGF-beta inhibited GEC growth in a time and dose dependent manner with a brief early exposure resulting in prolonged growth inhibition which was not reversible by EGF. Exposure to TGF-beta sufficient to maximally inhibit growth had no effect on EGF binding to GEC. More prolonged exposure to TGF-beta, however, did result in an increase in the apparent number of EGF receptors on GEC but no change in Kd. These studies suggest that EGF and TGF-beta released by inflammatory cells or platelets during the course of glomerular injury may play a role in modulating glomerular cell proliferation.

[Biological characteristics of Psoralea corylifolia L]

A study has been made on the biological characteristics of Psoralea corylifolia under general cultivating conditions. To search for the laws of growth and development so as to facilitate further studies on the cultivating techniques for higher production of Psoralea corylifolia.

Anti-lipid peroxidation and protection of ginsenosides against cerebral ischemia-reperfusion injuries in rats

The correlation between protective effect of ginsenosides Rb + R0 and brain endogenously-derived prostacyclin synthesis, thromboxane A2 formation and lipid peroxidation were estimated in rats. Ginsenosides Rb + R0 100 mg/kg iv 30 min before 4-vessel occlusion elevated 6-keto-PGF1 alpha level, declined thromboxane B2 and brain edema formation, reduced the rise of lipid peroxides and suppressed the reduction in both creatine phosphokinase (CK) and superoxide dismutase (SOD) activities in brain tissue after 40-min ischemia followed by 1-h reperfusion. Furthermore, these improvements were partially abolished by pretreating with iv indomethacin. It is concluded that ginsenosides possess protective effect on cerebral ischemia-reperfusion injury of rats and ginsenosides Rb + R0 are the active principles. The underlying mechanism of protection is ascribed partially or mainly to the facilitated synthesis and release of prostacyclin, reduced formation of thromboxane A2 and inhibited generation of free radicals and subsequent lipid peroxidation.

[Effect of electro-acupuncture of zusanli on unit discharges in the lateral hypothalamic area induced by stomach distension]

Previous studies in our laboratory have shown that some unit discharges of the neurons in Feeding Centre of the lateral hypothalamic area (LHA) may be inhibited by distending stomach. The present study was performed to observe the effect of electro-acupuncture of "Zusanli" point on the discharge-inhibitory reaction induced by distending stomach in rats. Among 52 unit discharges observed, 36 (69.2%) showed that electro-acupuncturing "Zusanli" point abolished the inhibitory reaction induced by distending stomach. The durations of the effect range from 5 to 15 minutes. These results indicate that the somatic input from "Zusanli" plant may influence the reactivity of Feeding Centre of LHA to the activity of stomach.

[Types of left ventricular hypertrophy and their functional changes in essential hypertension]

104 patients of hypertensive left ventricular hypertrophy (LVH) were studied by two-dimensional echocardiography. According to the changes of left ventricular wall thickness, wall mass, end-diastolic volume and ejection fraction, they were divided into three types (concentric, dilated, disproportionate): (1) Concentric LVH 83 cases (79.8%) with thickened ventricular wall and augmented mass. (2) Dilated LVH 13 cases (12.5%) with left ventricular cavity enlarged and both ventricular mass and volume increased, ejection fraction decreased. (3) Disproportionate LVH 8 cases (7.7%), similar to hypertrophic cardiomyopathy with excess increase in interventricular septal thickness. The thickness ratio between interventricular septal and left ventricular posterior wall was greater than or equal to 1.3.

Captopril and ramiprilat protect against free radical injury in isolated working rat hearts

The protection of angiotensin converting enzyme (ACE) inhibitors, captopril and ramiprilat, against free radical-mediated myocardial injury were studied in isolated working rat hearts. Free radicals were generated by electrolysis of Krebs-Henseleit solution with 10 mA direct current for 1 min. Both captopril (360 mumol/l) and ramiprilat (12.5 mumol/l) significantly reduced the decrease of left ventricle dP/dt'max, coronary flow (CF), myocardial superoxide dismutase (SOD) and creatine kinase (CK) activities and the elevation of S-T segment of epicardial ECG as well as the rise of myocardial malondialdehyde (MDA) content caused by electrolysed perfusate. Captopril afforded a dose-dependent protection on cardiac functions with various concentrations of 45, 90, 180 and 360 mumol/l. Iloprost (30 nmol/l), a stable mimetic of prostacyclin, could also alleviate free radical-mediated myocardial injuries. All the beneficial effects of ramiprilat (12.5 mumol/l) were abolished by the administration of indomethacin (5 mumol). In contrast, captopril (90 mumol/l) still exhibited significant protective effects after indomethacin (9 mumol) was administered, though these protective effects were insignificantly weakened. In order to assess the role of sulfhydryl (-SH) group in the effects of captopril, a SH-containing drug S8 and a disulfide DG4, both are deficient in ACE inhibitory properties in vitro, were examined. Data showed that S8 (180 mumol/l) provided a significant protection while DG4 showed no protective effect. It is concluded that ACE inhibitors can protect against free radical-induced myocardial damage. Ramiprilat, a non-SH-containing ACE inhibitor, inhibits free radical-induced damages mainly by stimulation of prostacyclin synthesis and/or release. In addition to this effect, captopril, a SH-containing ACE inhibitor, may exert additional anti-free radical effects by a mechanism which is probably related to the sulfhydryl group.

Dental caries in adult and elderly Chinese

This paper reports on a study of dental caries conducted among 1744 urban and rural Chinese (from 20 to 80 years old), who were selected by means of a systematic stratified sampling procedure. The prevalence of one or more decayed or filled teeth ranged from 48 to 90% in urban residents, and from 51 to 97% in rural residents, depending on age. The mean number of decayed or filled teeth ranged from 1.2 (+/- 1.9) among 20-29-year-olds, to 6.2 (+/- 5.5) among 70+-year-olds, and was highest among rural residents. Among 20-29-year-olds, the main components of the DFT were enamel lesions and fillings. Among 30-49-year-olds, the DFT consisted mainly of enamel lesions and filled teeth, as well as teeth with lesions involving the pulpal tissues. In subjects over the age of 50 years, lesions involving pulpal tissues were the predominant type, followed by root-surface lesions. In subjects below the age of 50 years, most of the caries experience derived from coronal surfaces, particularly occlusal surfaces. Root-surface caries was predominantly a feature of persons aged 50 years and above. Despite a large number of surfaces being at risk of root-surface caries, less than 10% of the surfaces were so affected. Although cross-sectional in nature, these data indicate that when the oral hygiene standards are poor, caries lesions continue to develop and progress throughout life. With age, dental caries becomes a substantial oral health problem in this population of adult and elderly Chinese, despite the availability of some dental services.

Tooth mortality and prosthetic treatment patterns in urban and rural Chinese aged 20-80 years

The study describes tooth mortality levels and pattern of prosthetic treatments in a sample of 1744 Chinese aged 20-80 yr who are residents of Beijing area. Complete edentulousness was rarely seen before the age of 60 yr. Beyond this age up to 26% were edentulous, depending on age and sex. The mean number of teeth present ranged from 10.0 to 29.7 depending on age, sex, and area of residence. Below the age of 60 yr very few persons had experienced extensive loss of teeth but thereafter the number of teeth missing was substantially increased. Prosthetic treatments in the form of partial dentures, crowns, and bridges were frequently observed even in the younger age groups. In all age groups the number of teeth exhibiting caries lesions involving the pulp was much higher than the number of teeth exhibiting extensive mobility. Although many people retain a high number of teeth even late in life our findings indicate a substantial need for, in particular, relief of pain services. Concurrently, emphasis must be placed on preventive programs aiming at interfering with ongoing disease.

Novel arrangement of rRNA genes in Mycoplasma gallisepticum: separation of the 16S gene of one set from the 23S and 5S genes

Large restriction fragments from the DNA of Mycoplasma gallisepticum S6 and PG31, which were prepared by digestion with BglI, BssHII, SmaI, or XhoI and which were separated by pulsed-field electrophoresis, were hybridized with probes containing most, or different parts, of an rRNA operon of Mycoplasma capricolum. The results showed that the genomes contained three widely separated rRNA loci. One locus contained genes for all three rRNA species and another contained 23S and probably 5S rRNA genes, whereas the third appeared to have only a 16S rRNA gene.

[Pacemaker syndrome: a report of 6 cases]

Six patients suspected to have "pacemaker syndrome" were studied with hemodynamic and electrophysiologic methods. Symptoms appeared after implantation of ventricular pacemaker (VVI). Mile symptoms such as dizziness and fatigue and severe symptom of heart failure were noted. The results of the study suggested that cardiac output decreases due to loss of atrial contribution to ventricular filling and also as a result of increase of systemic venous pressure. If the patient has V-A conduction, cardiac output will decrease further. Restoration of atrioventricular synchronization is essential in the treatment of the pacemaker syndrome.

[Electrophysiologic study of concealed accessory A-V pathway]

The presence of concealed accessory A-V pathways (CAP) was demonstrated in 14 out of 18 (78%) patients with supraventricular tachycardia (SVT) and narrow QRS complexes. Such a high percentage of CAP mediated AVRT is a quite unique finding. The importance of a standard programmed electrical stimulation protocol in documenting CAP is emphasized. Careful atrial mapping and premature ventricular stimulation during SVT are very helpful for diagnosis and localization of CAP. We considered that a V-A interval of 75 ms or more on intracardiac electrogram or a R-P interval of 85 ms or more on esophageal electrogram is a good criterion for AVRT utilizing an accessory pathway.