[Cardiovascular effects and underlying mechanisms of adenosine and its analogues]

The present work was aimed to define the cardiovascular effects and underlying mechanisms of adenosine and its analogues. The results showed that (1) adenosine and 2-chloroadenosine could induce an initial increase in MAP mediated by the adenosine A2 receptors in carotid body chemoreceptor, and a subsequent decrease in MAP, being attributed to the adenosine A1 receptors in heart and A2 receptors in blood vessels; (2) N6-cyclopentyladenosine (CPA, a selective adenosine A1 receptor agonist) inhibited the electrophysiological activity of pacemaker cells in sinoatrial node; (3) CPA markedly attenuated the development of early afterdepolarization, delayed afterdepolarization and triggered activity induced by isoproterenol; (4) endogenous adenosine might play an important role in the generation of anoxic bradycardia; (5) activation of adenosine receptors along with an increase in adenosine receptor density during the course of ischemic preconditioning might provide the protective effect on the ischemic heart injury; (6) the cardiovascular effects of adenosine and its analogues were mainly mediated by activation of ATP sensitive K+ channels coupled to adenosine receptors.

[Endothelin and ATP-sensitive potassium channel mediate electrophysiological changes induced by hypoxia in rabbit sinoatrial node]

The role of ET and KATP channel in hypoxia-induced negative chronotropic effect of pacemaker cells in rabbit sinoatrial node was studied with intracellular microelectrode technique. The results obtained were as follows: (1) Hypoxia produced a progressive decrease in the velocity of diastolic depolarization (VDD) of pacemaker cells resulting in a reduced rate of pacemaker firing (RPF), and induced a decrease in APD, especially APD50. (2) KATP channel opener cromakalim markedly induced a negative chronotropic effect in a concentration-dependent manner and significantly shortened APD50. KATP channel blocker glibenclamide alleviated the effects of hypoxia on pacemaker cells, thereby suggesting the involvement of KATP channel in the hypoxia-induced effects. (3) By superfusion of ET-1, the hypoxia-induced decrease in RPF was remarkably potentiated and the occurrence of pacemaker arrest was shifted to an earlier time. The hypoxia-induced effects could be effectively attenuated after pretreatment with BQ-123, implying the role of endogenous ET-1 release in hypoxia-induced effects. It is concluded that the negative chronotropic effect and the decrease in APD induced by hypoxia may be attributed to the activation of KATP channel and the release of endogenous ET.

Phenolic and triterpenoid glycosides from Aster batangensis

A new phenolic glycoside, asterbatanoside A [p-hydroxyacetophenone-4-O-beta-D-xylopyranosyl-(1-->6)-beta-D- glucopyranoside], and two new triterpenoid saponins, asterbatanoside B [2 alpha,3 beta,23-trihydroxyolean-12-en-28-oic acid-28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside] and asterbatanoside C [3-O-beta-D-glucopyranosyl-2 beta,3 beta,23-trihydroxyolean- 12-en-28-oic acid-28-O-beta-D-glucopyranoside] were isolated from the roots of Aster batangensis. Their structures were determined by spectroscopic methods and chemical evidence. The total synthesis of asterbatanoside A is also reported.

[Effects of endothelin on the electrical activity of sino-atrial pacemaker cells of rabbit]

The effects of endothelin-1 (ET-1) on the electrophysiological activity of pacemaker cells of rabbit sino-atrial node were examined by using intracellular microelectrode technique. The results obtained were as follows: (1) With superfusion of ET-1 (1-30 nmol/l), the velocity of diastolic depolarization (VDD) of pacemaker cells was significantly decreased in a concentration dependent manner, resulting in a reduced rate of pacemaker firing (RPF). (2) The decreases in RPF and VDD induced by ET-1 could be virtually blocked by pretreatment with ET(A) receptor blocker BQ-123 (20 or 100 micrograms/L). It was strongly suggested that the electrophysiological effects of ET-1 on the pacemaker cells were mediated by the ET(A) receptor. (3) The negative chronotropic action of ET-1 on the pacemaker cells was totally abolished by pretreatment with a kind of KATP channel blocker glibenclamide (10 mumol/L). On the basis of above results, it appears that the binding of ET-1 with ET(A) receptor may induce an activation of KATP channels with resultant increase in K+ current so as to decrease the velocity of diastolic depolarization in the pacemaker cells.

Circulating antigens in schistosomiasis: detection of 31/32-kDa proteins in sera from patients infected with Schistosoma japonicum, S. mansoni, S. haematobium, or S. intercalatum

A sandwich enzyme-linked immunosorbent assay (ELISA) was developed to detect 31/32-kDa schistosome proteins as circulating antigens in sera from schistosomiasis patients. A monoclonal antibody was used as a capture antibody and rabbit antiserum raised against purified 31/32-kDa proteins was the detecting antibody. Positive results were obtained with patients infected with Schistosoma japonicum (88%; n = 69), S. mansoni (80%; n = 56), S. haematobium (100%; n = 40), or S. intercalatum (94%; n = 65). Sera from uninfected Chinese and African individuals and from Chinese patients with trichinosis, cysticercosis, or paragonimiasis did not react in the assay. This ELISA appears to be valuable in diagnosing infections by all major human schistosome species.

Preliminary report on treatment of bone tumors with microwave-induced hyperthermia

Between July, 1992, and February, 1995, 62 patients with various bone tumors were treated with microwave-induced hyperthermia. The series had 47 cases of malignant tumors and 15 cases with benign tumors; most of the tumors occurred at or near knee joints (53/62 = 85.4%). The surgical procedure consisted of separating the tumorous segment from surrounding normal tissues with a safe margin, cooling the normal tissues (including the vital neurovascular bundle and the intrajoint structures) with a water circulation system while heating the tumor simultaneously with the microwave antenna array, and providing an adequate soft-tissue cover for the dead bone. The tumor core temperature and the surface temperature reached 108 and 65 degrees C, respectively. The duration of microwave irradiation was usually 40-50 minutes. Meanwhile, the temperature of the normal tissues was kept under 39 degrees C. The minimal and maximal periods of clinical observation were 3 months and 36 months, respectively, and the mean follow-up period was 17 months. The 62 cases were evaluated from both oncological and orthopedic points of view. Five cases had local recurrence and required amputation. The 57 other cases had excellent local control. Six malignancy cases died of lung metastasis during a period of 1-2 years. Pathological fracture occurred at devitalized bone in five cases. In most of the cases, the knee joints functioned well, were stable and painless, and had almost full range of motion. Single-photon emission-computed tomography study in 16 cases revealed that revascularization of the devitalized tumorous bone segment could be accomplished in 1 year or more. These results show that the use of microwave hyperthermia for the treatment of bone tumors can be considered to be a definitive operation procedure that is safe and is well tolerated by patients. The oncological and orthopedic results are very encouraging.

[Synthesis and antimicrobial activities of tetrahydro-2H-1,3,5-thiadiazine-2-thiones]

Ten 3-benzyl-5-substitued tetrahydro-2H-1,3,5-thiadiazine-2-thiones were synthesized and seven of them are reported for the first time. The structures of the compounds have been elucidated by UV, IR, H-NMR and elemental analysis. The in vitro activity of the compounds against 6 kinds of bacteria and 2 kinds of fungi was tested. The antimicrobial activities of all compounds are more potent than sulfadiazine sodium and less potent than norfloxacini. All compounds were found to be more active against gram-negative and less active against gram-positive bacteria and weak against fungi.

Protective effect of preconditioning on ischemic heart and characterization of adenosine receptors in ischemic rabbit hearts

AIM

To assess the role of adenosine receptors in the cardioprotective effect of preconditioning and the characterization of adenosine receptors in heart.

METHODS

In 18 anesthetized rabbits, myocardial ischemia was induced by occlusion of left descending coronary artery. ST segment elevation in epicardial electrogram was used as a criterion of acute ischemic injury. Myocardial adenosine receptors were measured using [3H] adenosine ligand.

RESULTS

After 60-min ischemia, epicardial ST segment elevation was higher in ischemia group (13.9 +/- 0.6 mV) than in the ischemic preconditioning group (3.1 +/- 0.5 mV). In membranes of the ventricular myocytes prepared from ischemic-preconditioning group, the density of adenosine receptors was higher than that of ischemia and sham ischemia groups (Bmax being 602 +/- 40, 348 +/- 28, and 335 +/- 30 pmol/g protein, respectively). Affinity of the receptors for the [3H] adenosine was not different in the 3 groups (Kd being 181 +/- 18, 169 +/- 21, and 196 +/- 24 nmol . L-1, respectively).

CONCLUSION

Activation of adenosine receptors along with an increase in adenosine receptor density during ischemic-preconditioning provides the basis for adenosine to exert its protective effect on the ischemic heart.

Hemodynamic effects of centrally administered adrenomedullin (13-52) in anesthetized rats

This study was conducted to investigate the effect of intracerebroventricular administration of adrenomedullin (13-52) [ADM(13-52)], a novel hypotensive peptide, on the hemodynamic parameters of anesthetized rats. ADM(13-52) was administered centrally in a dose of 0.4-3.2 nmol/kg. It provoked marked, prolonged and dose-dependent increases in mean arterial blood pressure, heart rate, stroke volume, cardiac index, left ventricular pressure, left ventricular dp/dtmax and dp/dtmin, but reduction in total peripheral resistance index. In addition, intracerebroventricular administration of ADM(13-52; 1.6 nmol/kg) provoked a marked increase in renal sympathetic nerve activity. Intracerebroventricular administration of artificial cerebrospinal fluid had no effect on the hemodynamic parameters and renal sympathetic nerve activity. The results indicate that ADM(13-52) exerts a central action on the cardiovascular system. The mechanisms of hemodynamic changes induced by central ADM(13-52) were preliminarily analyzed in this study. ADM might play a role in the central control of the cardiovascular system, although the confirmed mechanisms and the physiological implications are undetermined.

[Investigation of cervical Chlamydia trachomatis infection in gynecologic outpatients]

A group of 662 women in our gynecologic OPD were screened for Chlamydia trachomatis with direct immunofluorecence monoclonal antibody (DFA) staining technique. Their age distribution ranged from 16 to 60 years old. The overall positivity rate was 26.3%. Of the 269 pregnant women, 64 cases were found to have Chlamydia trachomatis infection, an infection rate of 23.74%. There was no statistically significant difference of infection rates among age groups. In the positive group, however, the rate of infertility was 25.43%, much higher than that in the negative group (12.88%, P < 0.01). And there was no statistical significance of infection rates between patients taking contraception and those did not. A positive correlation existed between the degree of cervicitis and the Chlamydia trachomatis infection.

Overexpression of MDM-2 mRNA and mutation of the p53 tumor suppressor gene in bladder carcinoma cell lines

To investigate the importance of oncogenes and tumor suppressor genes in bladder carcinogenesis, we determined the status of the expression of the MDM-2 and p53 genes and genetic alterations in the p53 gene in five bladder carcinoma cell lines and one kidney urothelial carcinoma cell line. Overexpression of MDM-2 mRNA was observed in three bladder carcinoma cell lines, J82, SCaBER, and BFTC-905. Amplification of the MDM-2 gene was not detected in any of the six cell lines by southern analysis. The deletion in the p53 gene was observed in J82, and point mutation was detected in J82 and BFTC-909, the kidney urothelial carcinoma cell line. In contrast, no mutations were found in codons 12, 13, and 61 in the Ha-ras and Ki-ras genes in these six cell lines. These results indicate that alterations in the p53-regulated pathway are important in bladder carcinogenesis.

Effects of N6-cyclopentyladenosine on afterdepolarizations and triggered activity induced by isoproterenol in guinea pig papillary muscle

AIM

To investigate the effects of N6-cyclopentyladenosine (CPA, selective adenosine A1 receptor agonist) on afterdepolarizations and triggered activity induced by isoproterenol (Iso) in guinea pig papillary muscle.

METHODS

The stable and reproducible early afterdepolarization (EAD) and delayed afterdepolarization (DAD) of guinea pig papillary muscle were induced by Iso 50 nmol.L-1. The parameters of EAD and DAD were recorded using intracellular microelectrodes.

RESULTS

CPA markedly attenuated the development of EAD, DAD, and triggered activity (TA) induced by Iso in guinea pig papillary muscle. The inhibitory effects of CPA on Iso-induced EAD and DAD were antagonized by 8-phenyltheophylline (8-PT) and glibenclamide (Gli).

CONCLUSION

ATP-sensitive K+ channels were involved in Iso-induced EAD and DAD, and in the inhibitory effects of CPA on EAD and DAD.

A serotypic study of hemorrhagic fever with renal syndrome in rural China

Apodemus agrarius was trapped in the fields and Rattus norvegicus was trapped within the houses in the villages of Jiande County, a region in the Zhejiang Province of China endemic for hemorrhagic fever with renal syndrome (HFRS). Antibodies to hantaviruses were detected in three (16.7%) of 18 A. agrarius and 12 (13.5%) of 89 R. norvegicus, whereas hantavirus antigens were detected in the lung tissues of four (22.2%) of 18 and nine (10.1%) of 89 of these rodents, respectively. Three hantaviruses, one from A. agrarius and two from R. norvegicus, were isolated and found to be antigenically similar to Hantaan and Seoul serotype viruses, respectively. A serologic study of 437 clinically defined HFRS patients conducted in Jiande County in 1988 revealed that the ratio of Hantaan (72.5%) to Seoul (26.8%) serotype virus infections was 2.7:1. Two epidemic seasons were found, with a major peak in November and a minor peak in June, and both were associated with Hantaan serotype virus infections that coincided with two seasonal peaks of the A. agrarius population and local agricultural activities in the fields. Seoul serotype virus infections occurred with a small peak during the months of December through May, in which in-house activities were dominant. All data suggested that Jiande County was an area endemic for HFRS, predominantly of the Hantaan virus serotype, combined with Seoul serotype virus infections.

Endogenous adenosine and ATP-sensitive potassium channel modulate anoxia-induced electrophysiological changes of pacemaker cells in sinoatrial node of guinea pigs

AIM

To investigate the electrophysiological effects of adenosine deaminase (ADase, an enzyme converting adenosine to inosine and ammonia), 8-phenyltheophylline (8-PT, a nonselective antagonist of adenosine receptors) and glibenclamide (Gli, a potent blocker of ATP-sensitive K+ channels) on anoxic pacemaker cells of SA node.

METHODS

Anoxia of pacemaker cells in SA node of guinea-pig was induced by perfused for 20 min with a modified K-H solution gassed with 100% N2 deprived of glucose. Parameters of action potentials including maximal diastolic potential (MDP), amplitude of action potential (APA), duration of 90% repolarization (APD90), maximal rate of depolarization (Vmax), rate of pacemaker firing (RPF), and velocity of diastolic (phase 4) depolarization (VDD) were recorded using intracellular microelectrodes.

RESULTS

Anoxia increased MDP, APA, and Vmax and decreased VDD, RPF in a time-dependent manner. ADase 10 U.L-1, 8-PT 0.1 mumol.L-1 and Gli 10 mumol.L-1 significantly attenuated the electrophysiological changes of pacemaker cells in sincatrial node induced by anoxia.

CONCLUSION

Endogenous adenosine and ATP-sensitive K+ channels may play an important role in the generation of anoxic bradycardia in guinea pigs.

Retrospective and prospective studies of hemorrhagic fever with renal syndrome in rural China

Residents of two villages in Zhejiang Province, China, were interviewed and serum samples were collected to assess prevalence of hantavirus infection. Antibody prevalence was 12% (219/1811), with a ratio of illness to infection of 1.0:5.4. Seroprevalence increased with age, but no association was found with sex. There was also no evidence of vertical transmission. One year later, 2.3% (30/1325) of seronegative subjects had seroconverted including 2 who had hemorrhagic fever with renal syndrome. Peak incidence of infection occurred in those 15-39 years old. Hantaan was the dominant serotype; Seoul serotype was less common (5:1). Host reservoirs were Apodemus agrarius in agricultural fields and Rattus norvegicus in houses. Risk factors for infection were traces of rat-contaminated food, travel to other areas for farm work, direct rodent contact, camping in grain fields, living in a house on the periphery of a village, stacking straw stacks outside houses, and keeping cats. All may provide exposure to infectious rodent reservoirs.

Metabolism of polynuclear aromatic hydrocarbon in human term placenta influenced by cigarette smoke exposure

The relative contributions of biologic and environmental factors on embryo-fetal development were elucidated in a population of pregnant women who were exposed to varying amounts of active cigarette smoke and women who were not exposed to cigarette smoke. The neonatal weight at birth, placental weight at delivery, duration of pregnancy, and placental xenobiotic (polynuclear aromatic hydrocarbon, PAH) metabolism potential were assessed in this population. The overall metabolic capability in exposed and unexposed placental tissue was measured by in vitro assays using microsomes and a PAH substrate, benzo[a]pyrene (B[a]P). Toxicity potential was determined by B[a]P-metabolite-DNA adduct generation under the same incubation condition. Cigarette smoke exposure increased the overall PAH metabolism potential in placental tissues by approximately 200% (nonsmoker 176.2 +/- 33.6, n = 25; smoker 524.5 +/- 75.5, n = 32 pmol/mg protein) whereas PAH-DNA adduct formation potential did not increase significantly over the basal level (nonsmoker 5002 +/- 830, n = 15; smoker 6172 +/- 1443, n = 22 fmol B[a]P equivalent/mumol DNA/mg protein). Exposure to cigarette smoke during pregnancy is deleterious to fetal development as reflected by reduced neonatal weight at birth. In contrast, placental weight reduction is indistinct, but placentae expressed markedly augmented overall xenobiotic (PAH) metabolism capability in response to cigarette smoke exposure during pregnancy, indicating placental metabolism may be an important mediator of adverse effects induced by such xenobiotic exposure.

[Correlation between bronchoalveolar lavage fluid angiotensin converting enzyme levels and T cell subsets in patients with sarcoidosis]

BALF ACE levels were assayed in patients with sarcoidosis, and their correlation with lymphocyte percentage and TH/Ts ratio in BALF were analysed. The results showed a positive correlation (r = 0.4453, P < 0.05; r = 0.7085, P < 0.01). BALF ACE level was decreased as patients with active sarcoidosis improved clinically, indicating that BALF ACE level may be a sensitive biological parameter in the diagnosis and disease activity assessment of sarcoidosis.

Detection of Schistosoma japonicum antigen (Sj31/32) in sera of Chinese patients using a sandwich ELISA based on monoclonal antibody

A sandwich-ELISA was developed using IgG from rabbits infected with Schistosoma japonicum as capture antibody and a monoclonal antibody as detecting reagent for circulating Sj 31/32 in patient sera. The assay detected circulating antigen in 36 of 53 sera from Chinese schistosomiasis japonica patients, but not in sera from healthy persons or patients with paragonimiasis, trichinosis or cysticercosis. This is the first demonstration that Sj 31/32 proteins may be used for circulating antigen-based serodiagnosis of schistosomiasis.

[Tumor microvascular bed and its reactivity to vasoactive agents: measurement of tissue blood flow and patho-morphological study]

Structural characteristics of tumor microvascular bed and its reactivity to vasoactive agents were studied by histological and ultrastructural examination and tissue blood flow measurement. The results showed that newly formed vessels in the tumor tissue consisted of a single layer of endothelial cells with multi-layer basement membranes and a few pericytes. Smooth muscle cells and nerve endings were absent. The tissue blood flow in highly proliferative parts of tumors was relatively constant and not influenced by tumor size, even though the distribution of neovasculature in tumor tissue was very uneven in distribution. The only vasoactive agent which can selectively increase the tumor blood flow was angiotensin II, whereas other adrenergic vasoconstrictors did not show this action.

Electrophysiological effects of N6-cyclopentyl-adenosine and [-]-N6-[phenylisopropyl]-adenosine on pacemaker cells in sinoatrial node of guinea pigs

The electrophysiological effects of N6-cyclopentyladenosine (CPA) and [-]-N6-[phenylisopropyl]adenosine (R-PIA) (both are selective adenosine A1 receptor agonists) on pacemaker cells in sinoatrial (SA) node of guinea pigs were investigated using intracellular microelectrodes. CPA and R-PIA increased the amplitude of action potential, amplitude of the maximal diastolic potential and maximal rate of depolarization (phase 0), but decreased the velocity of diastolic (phase 4) depolarization, the rate of pacemaker firing, and the duration of 90% repolarization in pacemaker cells of guinea pigs. 8-Phenyltheophylline (a nonselective antagonist of adenosine receptors) and glibenclamide (a potent blocker of ATP-sensitive K+ channels) inhibited the electrophysiological responses of pacemaker cells to CPA. These results suggest that the electrophysiological changes induced by CPA are adenosine receptor-dependent and mainly mediated by activation of ATP-sensitive K+ channels coupled to adenosine receptors.

[A histogenetic study on the carcinogenesis of colonic mucous membrane glands induced by 1,2-dimethylhydrazine in rats]

The relationship between atypical proliferation and carcinogenesis of colonic mucous membrane glands induced by different doses of 1,2-dimethylhydrazine (DMH) was studied by use of histopathological methods and sequential endoscopic observation. The results showed a significant increase of atypical glands in the flat mucosa with the increase in number of DMH injections, the degree of atypical proliferation becoming more serious with the increase of glandular ducts. The following changes were observed under sequential endoscopy: small elevations were first seen on the flat mucosa, then in sequence-flat elevations, hemisphere elevations, substem elevations and finally, stemmed elevations. At the same time, changes such as rubifaction, erosion, central depression and hemorrhage on the tumor surface were frequently encountered. It is concluded that atypical glandular proliferation in the flat mucosa of the colon is a precancerous lesion of colonic carcinoma.

Immunization of pigs against infection with Schistosoma japonicum using ultraviolet-attenuated cercariae

Since pigs are important in the zoonotic transmission of schistosomiasis japonica in China, a veterinary vaccine might contribute to the control of the disease in humans. Pigs were immunized with three doses each of 10,000 cercariae of Schistosoma japonicum attenuated with ultraviolet light (400 microWatt.min/cm2). The experiment was performed with portable irradiation equipment in a rural area of the Hubei Province (P.R. China). A challenge infection of 1,000 untreated cercariae was given 2.5 or 6 months after the last immunization, and age-matched naive pigs were challenged as a control. Immunized pigs developed about 90% resistance against the challenge. The liver egg load of these animals was reduced by over 90%. Less than 0.01% of the immunizing cercariae developed to adult parasites and the vaccination had no apparent adverse influence on the pigs' health.

Augmentation of polynuclear aromatic hydrocarbon metabolism of human placental tissues of first-trimester pregnancy by cigarette smoke exposure

OBJECTIVE

Polynuclear aromatic hydrocarbons are important components of cigarette smoke. The toxicity of polynuclear hydrocarbons depends on their metabolic biotransformation by tissues. This study was performed to assess the effects of cigarette smoke exposure on polynuclear aromatic hydrocarbon metabolism in the human placental tissues of first-trimester pregnancy.

STUDY DESIGN

The expression of essential enzymes that metabolize polynuclear aromatic hydrocarbons and regulate toxic metabolism, aryl hydrocarbon hydroxylase, epoxide hydrolase, and glutathione S-transferase, were determined by immunocytochemical staining of the specific enzymes in first-trimester placental samples from both smoker and nonsmoker donors. The overall polynuclear aromatic hydrocarbon metabolism by such tissues was quantitated by a radiometric assay with benzo[a]pyrene substrate in placental villi tissues and also in isolated trophoblast cells or in cultured trophoblast cells in the presence of polynuclear aromatic hydrocarbon agent.

RESULTS

Immunocytochemical staining revealed that aryl hydrocarbon hydroxylase was localized on trophoblast cells of first-trimester placentas from smoker donors. Epoxide hydrolase was present in stromal and trophoblast cells, and glutathione S-transferase (pi) was present in trophoblast cells of both nonsmoker and smoker subjects. In addition, the overall metabolism of polynuclear aromatic hydrocarbon xenobiotics in such tissues (8 to 11 weeks) of donors who smoked cigarettes was observed to be increased compared with that of nonsmokers by radiometric assay of metabolic products. The increased polynuclear aromatic hydrocarbon metabolism from such exposure was also shown in isolated and purified trophoblast cells of first-trimester placental villi and in culture of such trophoblast cells of nonsmoker donors with polynuclear aromatic hydrocarbon by the same assay procedure.

CONCLUSIONS

Therefore, contrary to previous assumptions, these data demonstrate that cigarette smoke exposure increases the polynuclear aromatic hydrocarbon metabolism of placentas even during the early stages of pregnancy. Augmented polynuclear aromatic hydrocarbon metabolism may produce genotoxic metabolites deleterious to conceptus development.

[Purification of 31/32 kDa proteins of adult Schistosoma japonicum and studies on their protective immunity]

Schistosoma japonicum adult worm 31/32 kDa proteins (Sj 31/32) were separated on polyacrylamide slab gels and purified by electrophoretic elution. These purified proteins were used to immunize mice in order to observe their protective immunity against challenge. The results of SDS-PAGE,EITB and ELISA indicated that the 31/32 kDa proteins separated and purified by means of these methods were pure and active. It was assumed that Sj 31/32 proteins could reduce worm burden and inhibit the fecundity of schistosome and formation of egg granuloma. The results suggested that 31/32 kDa S. japonicum proteins might be an important component of a multivalent vaccine against schistosomiasis japonica (Figs. 1-4).

[The effects of angiotensin II and other vasoactive agents on the blood flow in Yoshida ascites hepatoma]

The effects of angiotensin II and other six vasoactive agents on tissue blood flow of Yoshida rat ascites hepatoma AH109A and normal liver were measured by the hydrogen clearance method. The mean blood flow in the tumor peripheral part under normotensin was 11.9 +/- 8.2 ml/min/100 g tissue and was not influenced by tumor size. Tumor blood flow was more significantly increased in infusion angiotensin II than 0.5 mg/ml methoxamine; however, normal liver blood flow of tumor-bearing rats was unchanged in contrast to an increase seen in the tumor. A Pronounced reduction of tumor blood flow was found after administration of epinephrine, norepinephrine and ethylphenylephrine. In addition, metaraminol, phenylephrine as well as 1.0 and 2.5 mg/ml methoxamine were not found to significantly change the blood flow of the tumor.

Studies of the synthesis of biomarkers. XI. Synthesis of 4,5-secocholestane and 4-methyl-4,5-secocholestane

4,5-Secocholestane (1a) and 4-methyl-4,5-secocholestane (1b) were synthesized from cholesterol (2) in five and seven steps, respectively. The key intermediate, 5-oxo-4,5-secocholestan-4-al (7) was reduced by the Clemmensen method to afford 1a. Meanwhile, 7 underwent selective Wittig reaction, Clemmensen reduction, and hydrogenation to give another target molecule, 1b. The structure of an unknown biomarker was shown to be different from the proposed 1a by gas chromatographic and mass spectrometric comparison.

Synthesis, characterization, and antibacterial activity of transition metal complexes with 5-hydroxy-7,4'-dimethoxyflavone

Complexes of CuII, NiII, CoII, ZnII, FeIII, CrIII, CdII, and MnII with the natural product 5-hydroxy-7,4'-dimethoxyflavone have been synthesized and the probable structures of these complexes have been proposed on the basis of elemental analyses, molecular weight determination, magnetic moments, and electronic and IR spectral data. The presence of coordinated and crystal water molecules was demonstrated by thermal studies. The antibacterial activity of the ligand and all the complexes has been determined on gram positive and gram negative bacteria.

[Three-dimensional microstructure and its significance of pseudotubular formation in the crescents of rapidly progressive glomerulonephritis]

Tubuloid structure of the crescents in rapidly progressive glomerulonephritis (RPGN) was studied in order to detect its morphological features and functional significance by using three-dimensional microstructure method. The results showed that the tubuloid structure was actually pseudotubular formation in the crescents. Their inner lumens were communicating between the Bowman's capsular space and lumens of the renal tubules. It indicated that pseudotubular formation in the crescents may play an important role in repairing the damaged structure of those injured glomeruli.

Studies of the synthesis of biomarkers. X. Synthesis of 13,17-secodiacholestanes

13,17-Secodiacholestanes (6) were synthesized from cholesterol (1) in six steps. The key intermediates, (20R)- and (20S)-diacholest-13(17)-enes (3a and 3b), underwent ozonization and reduction to provide (20R)- and (20S)-13,17-secodiacholesta-13,17-dione (5a and 5b), respectively. On Clemmensen reduction, the diones (5a and 5b) yielded the target molecule 6. The structure of an unknown biomarker was shown to be different from the proposed 6 by gas chromatographic/mass spectrometric comparison.

Occupational dimethylformamide exposure. 3. Health effects of dimethylformamide after occupational exposure at low concentrations

A factory survey was conducted in a plant where N,N-dimethylformamide (DMF) was in use during the production of polyurethane plastics and related materials. In all, 318 DMF-exposed workers (195 men and 123 women) and 143 non-exposed controls (67 men and 76 women) were examined for time-weighted average exposure (to DMF and other solvents by diffusive sampling), hematology, serum biochemistry, subjective symptoms, and clinical signs. Most of the exposed workers were exposed only to DMF, whereas others were exposed to a combination of DMF and toluene. DMF exposure in the former group was up to 7.0 ppm (geometric mean on a workshop basis), whereas it was up to 2.1 ppm in combination with 4.2 ppm toluene. Both hematology and serum biochemistry, results (including aspartate and alanine aminotransferases, gamma-glutamyl transpeptidase and amylase) were essentially comparable among the 3 groups. There was, however, a dose-dependent increase in subjective symptoms, especially during work, and in digestive system-related symptoms such as nausea and abdominal pain in the past 3-month period. The prevalence rate of alcohol intolerance complaints among male (assumedly) social drinkers was also elevated in relation to DMF dose.

[Cohort study of seroepidemiology on hemorrhagic fever with renal syndrome]

A cohort study of seroepidemiology on hemorrhagic fever with renal syndrome (HFRS) was carried out in two villages, Jiande County, Zhejiang Province. 1325 persons who had not had antibodies to HFRS in 1987 were interviewed and re-examined in 1988. Seroconversion to HFRS antibodies was found in 30 persons (2.26%). Among them, were two clinical cases with an incidence rate of 0.151% and the rate of inapparent infection was 2.12%. Ratio of apparent to inapparent infection was 1:14. No infection was observed in children aged 2-4 years and subjects aged 60 years and over. The rate was lower in 5-14 years age group (1.42%) than in those of 15-59 age groups (1.47-4.26%). The infection rate in males (2.57%) was slightly higher than in females (1.96%). Results of stratified analysis and logistic regression analysis showed that living in houses located at the village periphery, having straw stack out of the house and rearing cat were risk factors of HFRS infection and their ORs were 3.0932, 3.3629, and 4.9970 respectively. Antibodies and antigens of HFRS were detected in A. agrarius and R. norvegicus captured in the villages.

Distribution of hantavirus serotypes Hantaan and Seoul causing hemorrhagic fever with renal syndrome and identification by hemagglutination inhibition assay

An epidemiologic evaluation of patients with hemorrhagic fever with renal syndrome from different locations in the People's Republic of China was conducted to define the prevalence of two Hantavirus serotypes, Seoul (SEO) and Hantaan (HTN). Serum specimens were collected between 5 and 14 days after the onset of illness and were tested for antibodies by both hemagglutination inhibition (HI) and plaque reduction neutralization (PRN). By the HI test, the geometric mean titer (GMT) of antibodies to SEO in the sera from individuals from Kaifeng City of Henan Province was five times higher than that to HTN. In contrast, by the HI test, the sera from individuals from Jiande County of Zhejiang Province had a GMT of antibodies to HTN that was seven times higher than that to SEO. In the sera from individuals from Shanghai, only a twofold difference was observed in HI antibody titers to the two hemagglutinins by the HI test, with that to HTN being higher than that to SEO. By the PRN test, the GMT ratios of antibody between HTN and SEO strains from individuals in Kaifeng, Jiande, and Shanghai were found to be 1:13, 14:1, and 2:1 respectively. A close correlation (r = 0.8219) and concordance rate (78.3%) were observed between the PRN and HI tests for the identification of the serotypes of individual cases of hemorrhagic fever with renal syndrome. The hantavirus serotypes from individuals in Kaifeng and Jiande were identified as predominantly SEO and HTN, respectively, and those from individuals in Shanghai had an indeterminant serotype defined by these two techniques. The HI test appears to be a simple and reliable way of determining the predominant hantavirus that causes HFRS in a given geographic area.

Transcoronary ethanol ablation of experimental ventricular tachycardia after epicardial ice mapping and localizing

Thirty-seven reproducible ventricular tachycardias (VTs) were induced in 19 dogs after the onset of myocardial infarction. The site of origin of VT was localized in 19 (59%) of 32 VTs by ice epicardial mapping. After 0.3-1.2 ml of 95% ethanol was injected into a small coronary artery supplying the arrhythmogenic area, VT was no longer inducible in 10 of 14 dogs. Intramyocardial ethanol (1-3 ml) was injected into the site of origin of VT in 9 dogs including 4 with VTs reinduced after intracoronary ethanol. Six of these VTs were not reinduced. Thus, the total efficacy rate was 84%. In 7 dogs, after injection of 0.4-1.2 ml (mean 0.5 ml) of 95% ethanol into a small normal coronary artery, the extent of the changes in ECG, CK-MB and pathology was found to be related to the size of myocardial damage and to the dose of ethanol. The smaller the dose of ethanol was given and the more distal the branch of coronary artery into which the ethanol was injected, the smaller the myocardial damage was. The data demonstrated that intracoronary or intramyocardial injection of ethanol may ablate the experimental VT induced by programmed heart stimulation in dogs after myocardial infarction, indicating that this approach may be useful and meaningful in some selected instances. However, it is necessary to limit the myocardial damage as far as possible.

Dissociation of tubular cell detachment and tubular cell death in clinical and experimental "acute tubular necrosis"

"Acute tubular necrosis" in humans is often characterized histologically by tubular cell loss and nonreplacement rather than by frank cellular necrosis. It has been assumed that tubular cells detach from the tubular basement membrane after the occurrence of irreversible cell injury and/or cell death. We examined voided urine from patients with native kidney and transplant kidney "acute tubular necrosis" and found significant tubular cell shedding with up to 100% viability of voided tubular cells, as determined by exclusion of trypan blue. Histochemical stains for the brush border enzyme gamma-glutamyl transpeptidase and electron microscopy of cell isolates demonstrated that 30 to 100% of the voided cells were of proximal tubule origin. Moreover, epithelial cell cultures were readily established from noncontaminated voided specimens, and more than 80% of the cells in monolayers expressed gamma-glutamyl transpeptidase activity in vitro. Electron microscopy of cell monolayers confirmed proximal tubular differentiation in the majority of cells in the monolayer, with the remainder having an appearance more consistent with distal origin. In rabbit models of acute ischemic (pedicle clamp) and toxic (HgCl2 and glycerol-induced) injury, tubular cell shedding was also significant, with a mean of 25 to 30% of the voided cells viable. Epithelial cells were successfully cultured and passed from animals with ischemic renal injury. In vitro studies were carried out in cultured human proximal tubular cells to assess suitability of this system for more direct study of the phenomenon of cell detachment in response to injury. We found significant changes in cell shape in response to exposure to anoxia and HgCl2 in these cultures, with extensive cell rounding and retraction at times when cell viability remained high. This in vitro system could prove useful for defining mechanisms of renal tubular cell detachment in response to injury and for examining potential interventions to prevent epithelial disruption and loss of functional integrity. These strategies may ultimately have clinical relevance in patients with "acute tubular necrosis".

[Clinical and experimental study on the treatment of children diarrhea by granule of children-diarrhea fast-stopping]

Granule of children-diarrhea fast-stopping is a proved recipe composed of seven medical herbs such as Poria cocos, haw charcoal, Euphorbia humifusa, etc. After more 20 years' clinical application of 419 cases, the total effective rate proved to be 96.4% and the cure rate 90%, much better than the control groups [TCM: gelian san and shenglingbaizhu san; WM: gentamycin and PPA]. It had the effect of fast-stopping diarrhea and shortening the recovery period. It also had excellent curative effect for acute and chronic diarrhea, for noninfective and infective diarrhea with virus or germs, and for the diarrhea due to moist heat and spleen weakness in TCM. Clinical tests and experiments showed that this medicine had no toxic or side effects. The diarrhea-cure mechanisms were (1) Inhibiting germs so as to eliminate pathogeny. (2) Adjusting and improving organism immunity function. (3) Accelerating the recovery of intestinal digestion and absorption functions. (4) Inhibiting intestinal movement.

Diarrhoea surveillance in children aged under 5 years in a rural area of Hebei Province, China

A surveillance of diarrhoeal diseases in children aged under five years was carried out from March 1986 to February 1987 in a rural area of Hebei Province, China. Using a cluster sampling method, 270 study children were selected from 30 villages to represent a population of 105,405. Parents noted episodes of diarrhoea in children on a calender using a given definition of diarrhoea. The findings were verified by trained village doctors and were recorded monthly in the county Health and Anti-epidemic Stations. Stools of diarrhoea-affected children were examined to detect causal agents of diarrhoea, once in each of four seasons of the year. Of the 270 children, 218 (80.74%) suffered from one or more than one attacks of diarrhoea with a 95% confidence interval between 75.94% and 85.54%. There was no death due to diarrhoea. The diarrhoeal incidence in children of 3-4-year age group was significantly less than that in the children of less than 3 years (p less than 0.05). In the children with diarrhoea, the number of mean episodes was 3.15 per child/year, and the total mean course of suffering was 14 days per child/year. The ratio of diarrhoeal episodes in spring, summer, autumn, and winter was about 2.5:5:2:1. July was the month of highest occurrence of diarrhoea (146; 21.28% of all episodes). The epidemiological parameters of the disease declined with the growing age of the children, and there was no gender-specific preponderance in the number of episodes. During the whole year, 21.7% of the diarrhoeal episodes were due to bacterial pathogens, 4% of the episodes were due to rotavirus, and 3.65% episodes were associated with the detection of Trichomonas hominis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Immunohistochemical study of folliculo-stellate cells in human adenohypophysis and in pituitary adenomas]

Significance of the appearance of folliculo-stellate cells (FSC) was studied in 59 human adenohypophyses and 58 pituitary adenomas after being stained with anti-S100 protein and 6 anti-pituitary hormone antibodies. S100 protein positive cells, stellate in shape with expending cytoplasmic processes among endocrine cells (EC) appeared in all the human adenohypophyses and had a tendency to be clustered in small groups characterized by gathering of 3 to 5 cells in the alveoli. Age or sex difference seemed to have no influence on the distributive density of FSC. FSC in the pituitary adenomas may be derived from two origins. One was the residue of normal pituitary tissue left in adenomas, and the other one seemed to be the chief component of the tumor, known as folliculo-stellate cell adenoma.

Schistosoma japonicum: an ultraviolet-attenuated cercarial vaccine applicable in the field for water buffaloes

Water buffaloes were vaccinated three times with 10,000 Schistosoma japonicum cercariae irradiated with ultraviolet (uv) light at a dose of 400 microW x min/cm2. The irradiation was performed with cheap, simple, and portable equipment in a rural area of Hubei Province (People's Republic of China). A challenge infection of 1000 untreated cercariae was given to six vaccinated and six naive control buffaloes, while two vaccinated animals were not challenged. The experiment was terminated 6 weeks after the challenge. Control animals had lost body weight and harbored a mean of 110 worms and 37 eggs per gram of liver. The vaccinated animals gained weight after the challenge and developed 89% resistance to infection with S. japonicum. Since schistosomiasis japonica is nowadays transmitted in China predominantly by domestic livestock, a uv-attenuated cercarial vaccine for bovines may contribute to the control of this disease.

Studies of the synthesis of biomarkers. VII. Synthesis of 5 alpha-(17R,20R)-14,15-secocholestane

5 alpha-(17R,20R)-14,15-Secocholestane (12) was synthesized from cholesterol (1) in 12 steps. The key intermediate, 5 alpha-cholest-14-en-3 beta-yl acetate (4), underwent ozonization, reduction, hydrolysis, and oxidation to provide 5 alpha-14,15-secocholesta-3,14,15-trione (8). One of the Clemmensen reduction products of 8 is 5 alpha(17R,20R)-14,15-secocholest-15-ol (11); treatment of the alcohol (11) with tosyl chloride and subsequent reduction with lithium aluminum hydride yielded the target molecule (12).

[Pathoanatomical and pathophysiological study of lung injury induced by activated complement in rat]

Acute lung injury induced by intravenous infusion of zymosan-activated plasma(ZAP) on Wistar rats was studied. A single infusion of ZAP resulted in an early occurrence of increased respiratory rate, decreased PaO2, elevated activity of superoxide dismutase(SOD) in the arterial blood and lung tissue. The results showed that the content of copperzinic superoxide dismutase(Cu Zn SOD) in bronchiolar columnar epithelial cells was elevated. Histological and electron microscopic examination showed that there was an accumulation of neutrophils in pulmonary microvessels and capillaries, endothelial cell and epithelial cell injury, and pulmonary edema etc. The tight junctions both in the epithelium and endothelium showed alterations in substructure including discontinuity, irregularity, free ends and distention of meshes as early as 2 to 4 h. In later stage, the severity of damage of tight junctions increased, while the number of strands in endothelial junctions reduced. All the parameters in the control group did not change significantly. From the results, the authors consider that acute lung injury is intimately related to the neutrophils and oxygen free radicals, the pathological basis of early pulmonary edema is alterations in the tight junctions of the alveolar epithelium and capillary endothelium.

[The effects of angiotensin II and other noradrenergic vasoconstrictors on the blood flow in Yoshida rat ascites hepatoma AH 109 A at same electrode position]

The differing effects of angiotensin II (AT II) and five other vasoactive agents on the tissue blood flow in Yoshida rat ascites hepatoma AH 109 A were studied at the same electrode position by a hydrogen clearance method. The elevation of blood pressure by AT II resulted in a 3.4-fold increases in the tumor blood flow. However, when AT II was reinfused, it resulted in only 2.1, 2.2, 2.3, 1.9 and 2.4-fold increases, respectively, after infusion of methoxamine, norepinephrine, metaraminol, epinephrine, and phenylephrine. A pronounced reduction and further reducing tendency in the tumor blood flow were found after administration of norepinephrine and epinephrine. In addition, metaraminol, phenylephrine, and methoxamine did not change significantly the blood flow of the tumor. The results of this present blood flow study further suggest that AT II acts more peripherally in the host vascular bed from which newly growing tumor vessels bud than other vasoconstrictors do.

Transient effects of subcutaneously administered prostaglandin E2 on cancellous and cortical bone in young adult dogs

The transient effects of prostaglandin E2 (PGE2) on cancellous and cortical bone in iliac crests and mid-tibial shafts of nine intact young adult dogs were evaluated following 31 days of treatment. Histomorphometric bone changes were characterized from in vivo fluorescent double-labeled undecalcified bone specimens. PGE2 caused an increase in cancellous bone remodeling evidence by increased in activation frequency; increased percent eroded and formation surfaces; increased mineral apposition and bone formation rates; and shortened resorption, formation, and total bone remodeling periods. Activated cancellous bone remodeling did not lead to decreased cancellous bone mass, indicating an imbalance between bone resorption and formation in favor of formation (activation----resorption----stimulated formation; A----R----F increases) at remodeling sites. The PGE2 treatment activated bone modeling in the formation mode (activation----formation; A----F) at the periosteal and endocortical surfaces and increased activation frequency of intracortical bone remodeling in the tibial shaft. Increased modeling activation converted quiescent bone surfaces to formation surfaces with stimulated osteoblastic activity (i.e., increased percent labeled periosteal and endocortical surfaces, mineral apposition rates, and woven and lamellar trabecular bone formation) leading to 9- to 26-fold increases in newly formed bone mass in subperiosteal, subendosteal, and marrow regions, compared to controls. However, increased intracortical bone remodelling elevated remodeling space (i.e., increased cortical porosity), producing a bone loss that partially offsets the bone gain. The combined events lead to a positive bone balance in PGE2-treated cortical bone, compared to a negative bone balance in control bones. Collectively our data suggest that in vivo PGE2 is a powerful activator of cancellous and cortical bone formation, which may be able to build a peak bone mass to prevent and/or correct the skeletal defects to cure osteoporosis.