[Step increase in shear stress effects on releasing prostacyclin of human umbilical vein endothelial cell]

Adopting the flow chamber, we studied the effect of step increase in shear stress on prostacyclin releasing of human umbilical vein endothelial cell (HUVEC). HUVEC monolayer was exposed to step increase in shear stress levels of 1, 10 and 20 dyne/cm2 for 100 minutes. By radioimmunoassay, 6-keto-PGF1 alpha in flowing out liquid from the flow chamber was measured. The results displayed: when HUVEC was not exposed to shear stress, the PGI2 released from HUVEC was not detectable; when HUVEC was exposed to shear stress, the flow onset led to an initial burst increase of PGI2 production rate, which went down subsequently within several minutes. We noticed that the larger the step increase of shear stress became, the higher the peak value of PGI2 production rate ascended, the quicker the peak value subsequently declined, and the higher the average value of PGI2 releasing rate in 80-100 minutes stood. The results demonstrated that in vivo hemorheological factor-the shear stress of blood flowing stimulated the release of prostacyclin from HUVEC.

[Adhesion of erythrocytes of patients with cerebral thrombosis to injured endothelial cells]

Using flow chamber system, we quantitatively studied the adhesion of erythrocytes (RBCs) of patients with cerebral thrombosis (CTh) to cultured human umbilical vein endothelial cells (HUVECs) treated with H2O2. The results showed that injured HUVECs enhanced adhesion of RBCs to HUVECs in patients with CTh. There is injury of endothelial cells in the pathogenetic and pathologic process of CTh, and the adhesion of RBCs to ECs promotes vaso-occlusive and vascular damage; thus the adhesion of RBCs to injured ECs might play an important role in the pathogenesis and pathologic process of CTh.

[A preliminary study on bioactivity of orange and tangerine peel extracts against aphis and mites]

An assay was made on the bioactivity of the extracts of tangerine peel from Cinocitrus tangerina, orange peel from Citrus sinensis and mixed tangerine peel from Cinocitrus sp. against aphis Semia phis heraclei, Aphis craccivora, Uroleucon gobonis and Myzus persicae using residual film or topical method, and against mites Tetranychus viennensis and T. trancatus using slide-dip or immersion method. Test results show that these extracts have strong bioactivity against aphids and mites. The corrected mortality regression equations and LC50 (or LD50) of these extracts to pests are presented.

[Rheologic properties of the human umbilical vein endothelial cells exposed to shear stress]

The function of vascular endothelial cells has recently become a hot spot in biomedical research. This paper reports the deformation properties of cultured human umbilical vein endothelial cells exposed to shear stress with the flow chamber. The umbilical vein endothelial cells were exposed to shear stress 0.6, 3.8 and 7.5 Pa for 12 h respectively. With microvideo recording and computerized morphologic analysis, the results demonstrated that the endothelial cells were elongated as a result of exposing to shear stress 3.8 or 7.5 Pa for 12 h. Their major axes were consistent with the flow direction. Furthermore the degree of elongation and orientation of endothelial cells depended on the shear stress and shear duration. The results were compared with those of three foreign laboratories; and the causes of agreement and difference were discussed. This study is the basic word for a series of future researches.

[A preliminary study on the antenatal diagnosis and prevention of the fetus toxoplasmosis infection]

For those pregnant women with an abnormal pregnancy history, the polymerase chain reaction (PCR) technique was adopted to screening the serum toxoplasmosis DNA (TOX-DNA). Then tests were made for further evidence of TOX-DNA in the amnionic fluids TOX-DNA was examined in cases with blood TOX-DNA positive. Gamma glutamyl transpeptidase (GGT) and alpha-fetoprotein (AFP) in the amnionic fluids were measured for reference, a antenatal diagnosis of the fetal congenital toxoplasmosis infection could thus be made. In the present paper, 9 out of 92 blood specimen were TOX-DNA positive, of the 9 cases, 5 had TOX-DNA and 4 had no TOX-DNA in the amnionic fluid tests. The results of follow-up examination in the 9 cases were in conformity with the ante natal diagnosis. This is an important procedure for diagnosis and prevention of maternal-fetal vertical infection of Toxoplasmosis.

A rapid simplified purification of bovine thrombin

A rapid simplified method was developed to obtain highly pure bovine thrombin. Prothrombin was directly activated when it was enriched from bovine plasma without prior purification. The activated thrombin was isolated by a single Heparin-Sepharose affinity chromatography step. About 87% of activated thrombin was recovered and the yield was 25.1 mg of thrombin per liter of starting plasma. Specific activity of the final preparation was 4018 NIH units/mg, representing a 402 fold purification over the starting material. Comparative experiments showed that the simplified method was about six times as effective as previous two-step methods.

Vascular barrier-enhancing effect of an endogenous beta-adrenergic agonist

Exogenous catecholamines have been proved to be active in the reduction of vascular permeability induced by various inflammatory mediators via beta-adrenoceptor activation, but it is not known whether an endogenous beta-adrenergic agonist has any effect. We studied it in skin and lung vessels. The results revealed that an intravenous bolus of isoproterenol (10 micrograms/kg) attenuated platelet-activating factor- and histamine-induced Evans blue dye extravasation in rat dorsal skin, while intraperitoneal administration of beta-adrenoceptor blocker propranolol (0.1 mg/kg) significantly increased the dye extravasation. Blockade of beta-adrenoceptor by propranolol for 12 h noticeably increased wet/dry lung weight ratio, lung water content, bronchoalveolar lavage (BAL) protein concentration, leukocyte count, and lipoperoxide degradation product malondialdehyde (MDA) content. In isolated perfused lung in vitro, propranolol (2.5 micrograms/ml) had no obvious effects on lung weight gain, fluid filtration coefficient, and pulmonary vascular pressure during the 20-min perfusion compared with control. The results suggested that endogenous beta-adrenergic agonist is an important factor in the maintenance of vascular integrity and the quiescent state of leukocytes, indicating the antiinflammatory role of catecholamines in physiological states and critical illnesses.

[A morphological study of experimental corneal neovascularization]

Corneal neovascularization (CNV) was induced by alkali burn injuries in 20 rabbit corneas. The process of CNV was observed with biomicroscopy in vivo and histologically by light and electron microscopy. At 8 hours after injury, an obvious acute inflammatory response as evidenced by infiltration of neutrophils had already occurred in the pericorneal limbal area. Many neutrophils in the extravascular space contained abundant intracytoplasmic phagolysosomes. The vascular sprouts appeared 2 days after injury. The infiltration of neutrophils and their debris were visible around newly formed blood vessels in the cornea. The results suggest that there be the participation and an inductive action of neutrophils in the pathogenesis of CNV.

Response of constrained and unconstrained bubbles to lithotripter shock wave pulses

The Gilmore formulation for spherical bubble dynamics [F. R. Gilmore, The Growth or Collapse of a Spherical Bubble in a Viscous Compressible Liquid (California Institute of Technology, Pasadena, CA, 1952), Rep. No. 26-4] is used to investigate the response of air bubbles to a variety of lithotripter shock waveforms. A modification of the Gilmore model is proposed to account for partial constraint of the bubble expansion that can be caused by bubble coatings (such as in echo contrast agents) and by tissues or vessels surrounding bubbles in vivo. In the modified formulation, a viscoelastic membrane is assumed to exist at the bubble interface to include the possible effects of the nonlinear elasticity and strain rate dependent viscosity on the bubble response. The stress induced in the membrane is assumed to be an exponential function of the bubble radius, which tends to restrict the bubble expansion. The viscosity is assumed to increase with the strain rate. In the absence of the membrane, the maximum bubble wall pressure induced by a negative (tensile) pulse is much larger than that induced by a positive (compressive) pulse of the same pressure waveform and amplitude. This difference increases with decreasing initial bubble radius. The addition of the viscoelastic membrane significantly decreases the predicted maximum bubble pressure and the difference in response between the positive and negative pulses. The effect of the time delay between double pulses (positive followed by negative or negative followed by positive) is also investigated for unconstrained bubbles.

Purification and properties of cow splenic biliverdin reductase

Biliverdin reductase was purified from cow spleen. The specific activity of the final enzyme preparation was 24.01 u/mg, representing 686-fold purification as measured with NADPH. The yield was 3 grams of enzyme per 100 grams of cow spleen. The purified enzyme was a monomeric protein with an apparent molecular weight of about 34,000 and an isoelectric point of about 6.2. The biliverdin reductase was specific for biliverdin and reduced IX alpha faster than the biliverdin isomers IX beta, IXr, or IX delta. The purified enzyme could utilize both NADH and NADPH, but the kinetic properties of the NADH-dependent and the NADPH-dependent enzyme activities were different: the time course of the NADPH-dependent reaction displayed a sigmoidal curve, whereas that of the NADH-dependent reaction did not. Km for biliverdin IX alpha was 4 x 10(-4) mM in the NADPH system, while it was 1.5 x 10(-3) mM in the NADH system. Both enzyme activities were inhibited by excess biliverdin, but the inhibition of the NADPH-dependent enzyme activity was more pronounced. The pH optimum was 7.0 with NADH, and 6.8 with NADPH.

Suppression by isoproterenol of endothelial cell morphology and barrier function changes induced by platelet-activating factor

Using a model to study vascular permeability on hydrostatically perfused bovine pulmonary artery endothelial cell (EC) monolayers and software to analyze cell morphological parameters automatically in a computer image workstation, we studied the effects of isoproterenol (IPN) on platelet-activating factor (PAF)-induced changes in EC monolayer permeability and cell morphological parameters. Albumin has fortifying effects on endothelial barrier function. As albumin concentration in the perfusate increased (0, 1, 5, 10, 20 mg/ml), EC monolayer hydraulic conductivity (Lp) decreased gradually while Lp of the filter membranes did not change. After treatment of the EC monolayer with PAF 10(-8) mol/liter for 30 min, transmonolayer fluid flow, protein clearance rate, and Lp value increased noticeably. At the same time, cell area decreased and intercellular distance and percentage of intercellular space area in total cell monolayer increased. Pretreatment with 10(-4) mol/liter IPN blocked PAF-induced EC permeability and morphological changes, suggesting that EC contraction and intercellular gap formation are important mechanisms for PAF-induced high vascular permeability. IPN inhibits the effects of PAF via stabilization of EC morphology, protection of intercellular junction, and blockade of intercellular gap formation.

A molecular genetic survey indicates the presence of a single, homogeneous strain of Echinococcus granulosus in north-western China

A combination of DNA methods, including conventional RFLP, PCR-RFLP and mitochondrial sequence analysis did not detect genomic variation in any of 117 E. granulosus isolates examined from a range of intermediate hosts, including humans, in north-western China. The genotype infecting all hosts was indistinguishable from the widespread and well recognised sheep strain of E. granulosus. The public health implication of the study is that most, if not all, livestock infected with E. granulosus in this region will act as reservoirs of human infection.

Carbohydrate supplementation spares muscle glycogen during variable-intensity exercise

Effects of carbohydrate (CHO) supplementation on muscle glycogen utilization and endurance were evaluated in seven well-trained male cyclists during continuous cycling exercise that varied between low [45% maximal O2 uptake (VO2 max)] and moderate intensity (75% VO2 max). During each exercise bout the subjects received either artificially flavored placebo (P), 10% liquid CHO supplement (L; 3 x 18 g CHO/h), or solid CHO supplement (S; 2 x 25 g CHO/h). Muscle biopsies were taken from vastus lateralis during P and L trials immediately before exercise and after first (124 min) and second set (190 min) of intervals. Subjects then rode to fatigue at 80% VO2 max. Plasma glucose and insulin responses during L treatment reached levels of 6.7 +/- 0.7 mM and 70.6 +/- 17.2 microU/ml, respectively, and were significantly greater than those of P treatment (4.4 +/- 0.1 mM and 17.7 +/- 1.6 microU/ml) throughout the exercise bout. Plasma glucose and insulin responses of S treatment were intermediate to those of L and P treatments. Times to fatigue for S (223.9 +/- 3.5 min) and L (233.4 +/- 7.5 min) treatments did not differ but were significantly greater than that of P treatment (202.4 +/- 9.8 min). After the first 190 min of exercise, muscle glycogen was significantly greater during L (79 +/- 3.5 mumol/g wet wt) than during P treatment (58.5 +/- 7.2 mumol/g wet wt). Furthermore, differences in muscle glycogen concentrations between L and P treatments after 190 min of exercise and in time to fatigue for these treatments were positively related (r = 0.76, P < 0.05). These results suggest that CHO supplementation can enhance prolonged continuous variable-intensity exercise by reducing dependency on muscle glycogen as a fuel source.

Internal stress wave measurements in solids subjected to lithotripter pulses

Semiconductor strain gauges were used to measure the internal strain along the axes of spherical and disk plaster specimens when subjected to lithotripter shock pulses. The pulses were produced by one of two lithotripters. The first source generates spherically diverging shock waves of peak pressure approximately 1 MPa at the surface of the specimen. For this source, the incident and first reflected pressure (P) waves in both sphere and disk specimens were identified. In addition, waves reflected by the disk circumference were found to contribute significantly to the strain fields along the disk axis. Experimental results compared favorably to a ray theory analysis of a spherically diverging shock wave striking either concretion. For the sphere, pressure contours for the incident P wave and caustic lines were determined theoretically for an incident spherical shock wave. These caustic lines indicate the location of the highest stresses within the sphere and therefore the areas where damage may occur. Results were also presented for a second source that uses an ellipsoidal reflector to generate a 30-MPa focused shock wave, more closely approximating the wave fields of a clinical extracorporeal lithotripter.

Mechanisms of endothelial cell-dependent leukocyte adhesion stimulated by platelet-activating factor

Platelet-activating factor (PAF) stimulates leukocyte-endothelial cell (EC) adhesion through its effects either on leukocytes or on ECs. ECs may be injured, synthesize, or express new adhesive proteins to increase leukocyte adhesion. Intermediary mediators produced by activated ECs are also likely involved in promoting leukocyte adhesion. Our experiments demonstrated that PAF induced no obvious damage to bovine pulmonary artery ECs evaluated by lactic dehydrogenase release rate, angiotensin-converting enzyme activity, and cellular malondialdehyde content. Treatment of EC monolayers with 10(-9) M PAF increased polymorphonuclear leukocyte (PMN) adhesion. Increasing PAF concentration did not induce more PMN adherence. PAF elicited both a rapid and prolonged increment of PMN adherence to EC monolayers. The rapid adherence was greatly attenuated by pretreatment of ECs with PAF receptor antagonist SRI 63-441 but was not affected by pretreatment of PMNs with SRI 63-441, suggesting that PAF increases PMN adherence rapidly through its effects on specific receptors on ECs. Increased PMN adherence lasted if PAF treatment of ECs was sustained for 3 or 6 h. Pretreatment of ECs with actinomycin D, a protein synthesis inhibitor, significantly decreased PAF-induced sustained PMN adherence, but the inhibition is incomplete, suggesting that other mechanisms than protein synthesis also participated in the prolonged PMN adherence. We concluded from the results that PAF may induce both rapid and prolonged PMN adhesion to ECs. The effects are receptor mediated. The prolonged PMN adhesion is partly the result of protein synthesis.

5-(Aminomethyl)-3-aryldihydrofuran-2(3H)-ones, a new class of monoamine oxidase-B inactivators

Both cis- and trans-5-(aminomethyl)-3-aryldihydrofuran-2(3H)-one hydrochloride salts (9 and 10) were synthesized efficiently in a 5-step sequence from arylacetic acids. Both compounds were found to be irreversible inactivators of monoamine oxidase B. These compounds constitute the first members of a new class of monoamine oxidase inactivators.

[Exercise prescription for obese children]

Exercise prescription for obese children was formulated according to the characteristics of development of aerobic capacity of children of China and obese children as follows: intensity: 50% of VO2 duration: 1 hr/day, 12 weeks; frequency: 5 days per week; type of exercise: rhythmical and aerobic in nature such as running and various endurance game-type activity (football).

Orthotopic hepatic transplantation in the dog

Orthotopic hepatic transplantation has become a well-established treatment modality for end-stage liver disease, and research in this field is constantly evolving. Of the 34 canine liver transplants performed in this study, 17 (50%) survived more than 3 days (mean survival time 15 days). Causes of perioperative death included hemorrhage (4), anesthetic complications (3), systemic anaphylaxis (3), portal vein thrombosis (3), hepatic venous outflow block (2), and hepatic artery thrombosis (2). Gentle handling with minimal dissection of the donor liver in situ resulted in a decreased incidence of hepatic venous outflow block. The incidence of biliary leak was similar irrespective of the method of biliary reconstruction, although the incidence of acute cholangitis was 56% in the cholecystoduodenostomy group compared with 0% in the choledochocholedochostomy cohort. Using celiac to common hepatic end-to-side arterial anastomosis with preservation of the gastroduodenal artery, thrombosis of the hepatic artery was encountered in four instances, an incidence similar to previously reported studies where end-to-end hepaticohepatic arterial anastomosis or donor aortic conduit was utilized. The incidence of postoperative intestinal intussusception was reduced from 40 to 0% in those who underwent transmesenteric intestinal plication following implantation of the liver. Among short-term survivors, sepsis was the most frequent noted complication (10), followed by intestinal intussusception (6), rejection (6), and gastrointestinal bleeding (1). Among recipient dogs that survived more than 3 days, rejection was the most common cause of graft loss (5), followed by biliary leak (4) and hepatic artery thrombosis (2).

Inhibition of rat lens aldose reductase by quercetagetin and patuletin

In this paper the results of inhibition of the Aldose reductase (AR) activity on Wistar rat lens by Quercetagetin extracted from Tagetes erects Linn and by Patuletin extracted from Tagetes patula Linn are reported. Quercetagetin inhibited AR of the rat lens by 93.9% at 10(-4) M, 76.0% at 10(-5) M and 13.3% at 10(-6) M. Patuletin inhibited AR of the rat lens by 100% at 10(-1) M, 80% at 10(-5) M and 22.7% at 10(-6) M respectively. The results show that these two flavones are lens AR Inhibitors, but further study should be done for the possibility of clinical application.

Cystic echinococcosis in the Xinjiang/Uygur Autonomous Region, People's Republic of China. II. Comparison of three levels of a local preventive and control program

A project to compare different levels of a hydatid disease control program was instigated and evaluated in 16 randomly selected villages in the Xinjiang/Uygur Autonomous Region, PRC (China). Factors tested included the effect of: 1) the role of a village hydatid disease control officer, 2) the use of praziquantel-medicated "bait" tablets for treatment of Echinococcus granulosus tapeworms in dogs, and 3) the use of educational materials for children and adults. Evaluation of contrasting treatment levels was done by determining infection rates of E. granulosus in about 25 dogs examined from each of the 16 villages before and after the trial period, and by use of pre- and post-treatment questionnaires distributed to 40 randomly selected households in each village. Optimum results were obtained in those villages which received medicated tablets and support visits from a control officer on a monthly basis (so-called "moderate intervention level").

Hydatid disease in China

Hydatid disease is one of the world's most geographically widespread zoonoses. It is present on all inhabited continents and occurs in tropical, subtropical, temperate, sub-arctic and arctic regions. The two countries with the greatest areas over which transmission occurs are almost certainly the Soviet Union and China. Until recently, however, very little information about hydatidosis in China was available outside the country(1). Since the 'open-door' policy over the past few years the great importance of hydatid disease in north and western China is gradually being realized.

[Detection and significance of anti-pre S2 in patients with hepatitis B and HBsAg carriers]

We studied anti-Pre S2 by ELISA incorporating a synthetic peptide corresponding to the pre S2 (120-150) sequence and a monoclonal anti-human IgG, conjugated with peroxidase in 139 patients with hepatitis B and HBsAg carriers. The positive rate was 90% inpatients with acute-hepatitis 6.7% in chronic active hepatitis and 2.5% in persistent hepatitis. No positive case was seen in the HBsAg carriers. These findings indicate that anti-pre S2 may contribute to virus clearance and early diagnosis. The coexistence of anti-pre S2 with pre-S2 antigen was found only in patients with acute hepatitis, and anti-pre S2 may be coexistent with HBeAg in acute hepatitis, whereas all HBeAg positive patients with chronic hepatitis and HBsAg carriers lacked anti-pre S2. Comparing with anti-HBc IgM, anti-HBs and anti-HBe, anti-pre S2 is an earlier antibody in humoral immune response to HBV infection during the acute phase of hepatitis.

[A pharmacognostical study on the fruits of Cnidium monnieri (L.) Cuss]

The fruits of three species are used as the Chinese drug "Shechuangzi", namely Cnidium monnieri, C. monnieri var. formosana and C. japonicum, among which only C. monnieri is the real sort. The authors have distinguished them by macroscopic and microscopic structures and TLC. The total coumarin, trace element and amino acid contents are reported.

Cystic echinococcosis in the Xinjiang/Uygur Autonomous Region, People's Republic of China. I. Demographic and epidemiologic data

Demographic and epidemiologic data on those factors potentially related to the prevalence and transmission of hydatid disease caused by Echinococcus granulosus were collected in 1987 from each household in 85 villages in the two communities of Yuanhucun and Ershilidian within Hutubi County in the Xinjiang/Uygur Autonomous Region, PRC, with additional questionnaire data collected from approximately 40 households randomly selected from each of 16 villages within those communities. Yuanhucun and Ershilidian represent a combined area of 522.7 square km, and have 4,853 households with 25,684 inhabitants. Of those households, 69.9% are of the Han ethnic group, 22.1% Hui, 5.3% Uygur, and 2.7% Kazak. The total number of animals censused included 4,169 dogs, 41,369 sheep, 3,673 goats, 2,639 cattle, 5,400 pigs, 1,472 horses, and 59 donkeys. Levels of infection of the causative organism of cystic hydatid disease in various hosts were: dogs harboring Echinococcus granulosus tapeworms - 63 (16.2%) positive of 390 examined in 16 villages; domestic animals with hydatid cysts - 1,593 (88.6%) sheep of 1,797 examined, 69 (56.1%) of 123 goats, and 47 (94.0%) of 50 cattle; and 15 surgeries in inhabitants from 85 villages during the last 16 months prior to completion of the survey (annual case rate of 43.8/100,000). Questionnaire data collected from inhabitants in 16 villages showed that about 82% of the families owned at least one dog and 78% owned sheep. Of those families with sheep, most (84%) killed sheep for meat at least periodically, 76% had seen hydatid cysts in liver or lungs of butchered animals, and 77% routinely gave raw offal to their dog.(ABSTRACT TRUNCATED AT 250 WORDS)