[Correlation of qAnti-HBc with antiviral efficacy in children with chronic hepatitis B and exploration of its possible immune mechanism].

Objective: To compare the baseline difference in the quantitative hepatitis B core antibody levels (qAnti-HBc) between non-response and response group in children with HBeAg-positive chronic hepatitis B (CHB) who received antiviral therapy, and further explore the proportion and functional activity of CD8 + memory T lymphocyte subsets with different qAnti-HBC levels in peripheral blood of children. Methods: The baseline anti-HBc quantification (qAnti-HBc) levels of 85 children with HBeAg-positive CHB who visited the Department of Infectious Diseases, Children's Hospital of Chongqing Medical University from June 2018 to December 2020 were detected retrospectively. The relationship between the baseline qAnti-HBc level and HBeAg serological response in 37 children who received antiviral therapy was analyzed. The proportion of CD8(+) memory T lymphocyte subsets and the secretion levels of interferon (IFN) γ, and tumor necrosis factor (TNF) α in peripheral blood of 59 children at baseline were detected by flow cytometry. The relationship between qAnti-HBc level and the proportion and functional activity of CD8(+) memory T lymphocyte subsets was analyzed. Pearson's Chi-square test was used to compare the count data. Mann-Whitney U test or Kruskal-Wallis test was used to compare measurement data between two or more groups, and Spearman's rank correlation analysis was used for the correlation between continuous variables. Results: Among 37 children who received entecavir (ETV, 21/37 cases) or pegylated interferon (Peg-IFN, 16/37 cases), 18 cases had developed HBeAg seroconversion (10/ 21 cases in the ETV group, 8/16 cases in the Peg-IFN group). The baseline qAnti-HBc level was significantly higher in the response group [4.71 (4.64~4.81) log(10)IU/ml] than the non-response group children [4.54 (4.45~4.64) log(10)IU/ml, Z = -3.316, P = 0.001]. The proportion of CD8(+) Tem, CD38(+)CD8(+) Tem, CD38(+)CD8(+) Temra cells and the levels of IFNγ and TNFα secreted by CD8(+) T lymphocytes were significantly higher in the high-qAnti-HBc group than the low-qAnti-HBc group (P < 0.05). The proportion of CD8(+) Tem, CD38(+)CD8(+) Tem and CD38(+)CD8(+) Temra cells was significantly higher in ALT > 1× upper limit of normal value (ULN) group than ALT≤1×ULN group (P < 0.05). However, there were no significant differences in the levels of IFNγ and TNFα secreted by CD8(+) T lymphocytes between the two groups (P > 0.05). Spearman's correlation analysis showed that qAnti-HBc was positively correlated with the proportion of CD8(+) Tem, CD38(+)CD8(+) Tem, CD38(+)CD8(+) Temra cells and the level of IFNγ secreted by CD8(+)T lymphocytes (P < 0.05). Additionally, ALT was only positively correlated with the proportion of CD38(+)CD8(+) TEM and CD38(+) CD8(+) Temra cells (P < 0.05). Conclusion: Raised baseline qAnti-HBc level is related to the HBeAg serological response to antiviral therapy in children with CHB. Peripheral blood effector CD8+ T lymphocytes of CHB children with higher qAnti-HBc show stronger phenotype and functional activation characteristics, which may shed some light on the underlying immune mechanism related to antiviral therapy efficacy in children with CHB.

[Analysis of liver pathological characteristics and exploration of noninvasive markers of liver fibrosis in children with chronic hepatitis B].

Objective: To analyze and summarize the characteristics of liver pathology and their relation to clinical markers and further explore noninvasive markers of liver fibrosis in children with chronic hepatitis B. Methods: Data of 80 hospitalized children with chronic hepatitis B who underwent liver biopsy without antiviral treatment from 2011 to 2020 were retrospectively analyzed. Inflammation and liver fibrosis characteristics were analyzed in children of different ages and genders. Variables with good correlation with liver fibrosis stage were selected to establish a non-invasive diagnostic score of liver fibrosis in children. Measurement data was used to compare the t-test or rank sum test. Mantel-Haenszel χ (2) test was used for bidirectional ordered grouping data. Spearman's rank correlation test was used for rank correlation analysis. Receiver operating characteristic curve (ROC) was used to evaluate the diagnostic value of the newly established diagnostic score in children with liver fibrosis. Results: The median age of the children was 6.4 years. HBV DNA level was high (P50 = 7.6 log(10) IU/ml), and serum alanine aminotransferase (ALT) in P50 was 171 U/L (< ULN: 5 cases, ULN-2ULN: 10 cases, > 2 ULN: 65 cases). Pathological analysis showed that the incidence of liver tissue inflammation was 97.5%, and the proportion of patients with G≥2 was 42.5%, while S≥2 was 36.3%. The incidence rate of liver fibrosis and liver cirrhosis was 81.3%, and 1.3%, respectively. The changes in liver tissue inflammation and fibrosis were gradually aggravated with the increase of age, and the proportion of high-grade inflammation and liver fibrosis in male children was higher than that in female children. Serum levels of glutamyl transpeptidase (GGT), γ-glutamyltransferase/platelet ratio (GPR) and HBeAg had a good correlation with fibrosis stage (r(s) = 0.397, 0.389, and - 0.311) in children with chronic hepatitis B. The combination of GGT, GPR and HBeAg can establish a non-invasive diagnostic score for evaluating liver fibrosis in children. When the score is less than 1.5, it can be diagnosed as S0, and 1.5 ≤ score < 3.5, it can be diagnosed as S1; 3.5 ≤ score < 5.5, the diagnosis of fibrosis is S2; score≥ 5.5, the diagnosis of fibrosis is S≥3. The sensitivity and specificity were 80%, 83%, 86%, and 53%, 55%, 67%, respectively. Conclusion: The incidence of liver tissue inflammation in children with chronic hepatitis B with elevated and fluctuating transaminase levels is high, and the pathological changes of liver tissue aggravate with the age of the children. GGT, GPR and HBeAg have a good correlation with liver fibrosis in children with chronic hepatitis B. Therefore, combining the above-mentioned markers to establish a new noninvasive diagnostic score has certain diagnostic value for liver fibrosis stage S0-S3 in children with chronic hepatitis B.

Development of a SYBR Green I real-time PCR assay for detection of novel porcine parvovirus 7.

In this study, we developed a SYBR Green I real-time PCR method for the rapid and sensitive detection of novel porcine parvovirus 7 (PPV7). Specific primers were designed based on the highly conserved region within the Capsid gene of PPV7. The established method was 1,000 times more sensitive than the conventional PCR method and had a detection limit of 35.6 copies. This method was specific and had no cross-reactions with PCV2, PCV3, PRV, PEDV, PPV1, and PPV6. Experiments testing the intra and interassay precision demonstrated a high reproducibility. Testing the newly established method with 200 clinical samples revealed a detection rate up to 17.5% higher than that of the conventional PCR assay. The established method could provide technical support for clinical diagnosis and epidemiological investigation of PPV7.

[Effect of hepatitis B virus preC/C and S gene antigen epitope mutations on HBeAg serological status in patients with chronic hepatitis B].

Objective: To explore the effect of HBV preC/C and S gene antigen epitope mutations on HBeAg serological status in patients with chronic hepatitis B. Methods: Thirty-five cases with chronic hepatitis B without antiviral therapy were enrolled in this cross-sectional study. Nested PCR-TA cloning-sequencing method was used to screen HBV preC/C and S gene mutation sites related to HBeAg serological status. Then, in the longitudinal study (60 cases), the independent correlation between HBV preC/C and S gene antigen epitopes mutations and HBeAg status was explored by using multiple regression models to correct the correlated confounding factors. Results: In this cross-sectional study, 64.4% of preC/C and 68.2% of S mutations had occurred in the epitope region. There were ten mutation sites (PreC/C50, 55, 79, 84, 103, 126, 145, 184 and s110, s213) correlated with HBeAg negative status (P < 0.05). After adjusting for confounding factors such as age, gender, HBV genotype, serum alanine aminotransferase level and precw28 * mutations in the longitudinal studies, the results showed that TC cell epitope (prec47-56, prec117-125, s208-216) and Th cell epitope (prec176-185) were the main independent risk factors affecting the host HBeAg serological status. Conclusion: HBV preC/C region (PreC47-56, PreC117-125 and PreC176-185) and S region (s208-216) epitope mutations are the main independent factors affecting the host HBeAg status, suggesting that these epitope mutations may be involved in the HBeAg seroconversion.

[A new attempt with lipoprotein lipase agonists in the treatment of nonalcoholic steatohepatitis].

Objective: To analyze non-alcoholic steatohepatitis (NASH)-related differentially expressed genes (DEGs) by bioinformatics methods to find key pathways and potential therapeutic targets for NASH. Methods: GSE61260 chip was downloaded from the public microarray database and liver biopsy samples from 24 NASH cases and 38 healthy controls were included. The Limma software package in R language was used to screen DEGs under the condition of difference multiple > 1.5 and adj. P < 0.05. The clusterProfiler software package was used for GO analysis and KEGG analysis. The STRING online database was used for protein-protein interaction analysis, and the L1000 and DrugBank databases were used for drug prediction. Results: Compared with healthy control group, 857 DEGs were screened out in NASH group including 167 up-regulated genes and 690 down-regulated genes. GO analysis showed that DEGs were mainly involved in inflammation and cholesterol metabolism. KEGG analysis showed that DEGs were mainly enriched in PPAR, non-alcoholic fatty liver disease, oxidative phosphorylation and other signaling pathways. Among them, eight genes of ACSL4, CYP7A1, FABP4, FABP5, lipoprotein lipase, ME1, OLR1 and PLIN1 were enriched in PPAR signaling pathway, and 165 interaction nodes were formed with 47 DEGs-encoded proteins. Lipoprotein lipase interacted with 21 DEGs, and its up-regulated expression had improved lipid metabolism, insulin resistance and anti-inflammatory effects. Four drugs (gemfibrozil, bezafibrate, omega-3 carboxylic acid and glycyrrhizic acid) were screened by L1000 and DrugBank to activate lipoprotein lipase. Presently, these four drugs are clinically used to treat hypertriglyceridemia or to improve inflammation. In this regard, we speculated that the pharmacological effects of these four drugs had improved NASH by activating lipoprotein lipase to promote liver lipid metabolism and alleviate inflammation. Conclusion: PPAR signaling pathway is closely associated to the occurrence and development of NASH, and thereby lipoprotein lipase agonist is a new attempt to treat NASH.

Based serum metabolomics analysis reveals simultaneous interconnecting changes during chicken embryonic development.

Metabolic disorder is a major health problem and is associated with a number of metabolic diseases. Due to native hyperglycaemia and resistance to exogenous insulin, chickens as a model had used in the studies of adipose tissue biology, metabolism and obesity. But no detailed information is available about the comprehensive changes of serum metabolites at different stages of chicken embryonic development. This study employed LC/MS-QTOF to determine the changes of major functional metabolites at incubation day 14 (E14d), 19 (E19d) and hatching day 1 (H1d), and the associated pathways of differential metabolites during chicken embryonic development were analysed using Metabolite Set Enrichment Analysis method. Results showed that 39 metabolites were significantly changed from E14d to E19d and 68 metabolites were significantly altered from E19d to H1d in chicken embryos. Protein synthesis was promoted by increasing the concentrations of L-glutamine and threonine, and gonadal development was promoted through increasing oestrone content from E14d to E19d in chicken embryos, which indicated that serum glutamine, threonine and oestrone contents may be considered as the candidate indicators for assessment of early embryonic development. 2-oxoglutaric acid mainly contributed to enhancing the citric cycle, and it plays an important role in improving the growth of chicken embryos at the late development; the decreasing of L-glutamine, L-isoleucine and L-leucine contents from E19d to H1d in chicken embryonic development implied their possible functions as the feed additive during early posthatch period of broiler chickens to satisfy the growth. These results provided insights into understand the roles of serum metabolites at different developmental stages of chicken embryos, it also provides available information for chicken as a model to study metabolic disease or human obesity.

Systematic review with meta-analysis: combination treatment of regimens based on pegylated interferon for chronic hepatitis B focusing on hepatitis B surface antigen clearance.

BACKGROUND: The seroclearance of hepatitis B surface antigen (HBsAg) in patients with chronic hepatitis B (CHB) is considered to be associated with favourable clinical outcomes. AIMS: This meta-analysis was performed to establish the proportion of HBsAg loss rates among CHB patients who received combination treatment based on pegylated interferon (PegIFN). Four combination strategies have been studied with the aim of improving HBsAg loss: "de novo," "NA-experienced," "switch-to" and "add-on." This meta-analysis was performed to determine which, if any, of these combination strategies was more effective. METHODS: Medline, Web of Science and Embase databases were searched from inception to December 2017. The proportion of patients who achieved HBsAg loss after combination therapy was pooled using a random-effects model. RESULTS: Twenty-four studies fulfilled the meta-analysis criteria. The overall pooled proportion suggested that the rate of HBsAg loss could be increased to 9% (95% CI: 7%-12%) based on the combination treatment in CHB patients. Compared with "de novo" strategy (8%, 95% CI: 6%-10%), the "nucleos(t)ide analogues-experienced" (11%, 95% CI: 8%-15%) was found to be more likely (P = 0.036) to achieve a response. Compared with the "add-on" strategy (8%, 95% CI: 5%-13%), the "switch-to" (14%, 95% CI: 9%-20%) was found to be more likely (P = 0.012) to achieve HBsAg loss. CONCLUSION: The "nucleos(t)ide analogues-experienced" strategy was more effective than the "De novo" strategy in achieving HBsAg loss for CHB patients. Combination treatment using regimens based on Peg-IFN may be useful to help nucleos(t)ide analogues-treated patients, who have experienced at least 48 weeks of nucleot(s)ide analogue, achieve HBsAg seroclearance.

Metabolomics reveals the mechanism of (-)-hydroxycitric acid promotion of protein synthesis and inhibition of fatty acid synthesis in broiler chickens.

(-)-Hydroxycitric acid (HCA), a major component of Garcinia cambogia extracts, has been shown to suppress BW gain and fat accumulation in animals and humans. However, the mechanism remains unknown. In this study, gas chromatography-mass spectrometry was used to analyse serum metabolites, and principal component analysis and partial least-squares-discriminant analysis models were generated to analyse serum metabolite changes in broiler chickens after the administration of (-)-HCA at 0, 1000, 2000 and 3000 mg/kg diets for 28 days. Metabolites showing significant changes were screened by 'variable importance in the projection' plots. The results showed that 20 metabolites in the 1000 mg/kg (-)-HCA treatment group and 16 metabolites in 3000 mg/kg (-)-HCA treatment group were significantly altered. Metabolites pathway enrichment analysis indicated that these metabolites were mainly associated with metabolism of amino acids, protein synthesis, citric acid cycle, and uric acid and fatty acid synthesis. The data indicated that (-)-HCA promoted protein synthesis by regulating the metabolic directions of amino acids. At the same time, (-)-HCA treatment inhibited fatty acid synthesis by promoting the citric acid cycle, resulting in reduced cytosolic acetyl-CoA content in broiler chickens. The present study identified global changes in metabolites and analysed the main canonical metabolic pathways in broiler chickens supplemented with (-)-HCA. These results will deepen our understanding of the mechanism of (-)-HCA's effects in animals.

Peginterferon is preferable to entecavir for prevention of unfavourable events in patients with HBeAg-positive chronic hepatitis B: A five-year observational cohort study.

At present, the long-term effects of pegylated interferon-α (PEG-IFN-α) and entecavir (ETV) are controversial. Studies directly compared the long-term outcomes of these two drugs have not been completed. This study was designed to compare the clinical outcomes of PEG-IFN-α vs ETV therapy in Chinese patients with chronic HBV infection. From September 2008 to December 2016, a large, observational, open-label, prospective cohort study of HBeAg-positive patients with CHB who received PEG-IFN-α or ETV therapy was carried out at the Second Affiliated Hospital of Chongqing Medical University. Cumulative incidences of unfavourable events were calculated with respect to treatment type. Based on the REACH-B model, we compared the observed incidence of hepatocellular carcinoma (HCC) with the expected incidence in each group. PEG-IFN-α-treated patients showed a lower cumulative incidences of unfavourable events and cirrhosis than those treated with ETV (P = .031; P = .044, respectively). Impact factor exploration indicated that treatment type and platelet count are significantly associated with the occurrence of unfavourable events. Based on the REACH-B model, a lower observed cumulative incidence of HCC was observed in PEG-IFN-α-treated patients than predicted (P = .038). However, there was no significant difference of the cumulative HCC incidence between the observed and the predicted cases for ETV-experienced patients (P = .36). Treatment with PEG-INF-α leads to a lower incidence of unfavourable events including cirrhosis and HCC than ETV in patients with HBV. Treatment type and baseline platelet count may be two important factors associated with the long-term clinical outcomes of patients with CHB.

[The role of cytochrome P450 in nonalcoholic fatty liver induced by high-fat diet: a gene expression profile analysis].

Objective: To clarify the role of cytochrome P450 in nonalcoholic fatty liver disease (NAFLD) by RNA-Seq and bioinformatics analysis. Methods: A total of 20 male C57BL/6 mice were used. Ten mice were fed with high-fat diet (D12492, 60% kcal fat) for 16 weeks to establish a mouse model of NAFLD, and the other 10 mice were fed with low-fat diet (D12450B, 10% kcal fat) as control group. At the end of the experiment, the body weight, liver weight, and hepatic triglyceride (TG) content were measured. Meanwhile, HE staining and RNA-Seq analysis were performed for the liver tissues. The differentially expressed genes were screened out and subjected to bioinformatics analysis, including KEGG and GO BP enrichment analyses and interaction network analysis. Comparison of means between the two groups was made using t-test. Results: Compared with the control group, the mice in the model group were obviously obese, with significantly increased body weight (41.41 ± 6.01 g vs 28.78 ± 1.79 g, t = 6.04, P < 0.01) and liver weight (1.38 ± 0.30 g vs 1.08 ± 0.10 g, t = 2.89, P < 0.01). The mice in the model group showed obvious steatosis, accompanied by a small amount of inflammatory cell infiltration, but with no obvious fibrosis, according to the results of HE staining. In addition, the hepatic TG content in the model group was significantly increased compared with that in the control group (0.64 ± 0.01 mg/mg vs 0.29 ± 0.06 mg/mg, t = 10.11, P = 0.04). Compared with the control group, a total of 367 differentially expressed genes, including 211 down-regulated and 156 up-regulated ones, were identified in the model group according to the RNA-seq results. Meanwhile, 19 CYP450 subtypes, accounting for 5% of the differentially expressed genes, were identified, and CYP2E1, CYP2C70, CYP3A11, CYP3A25, CYP2D26, CYP4A10, CYP17A1, CYP2B10, and CYP2C38 were involved in oxidative stress, steroid hormone metabolism, fatty acid metabolism, arachidonic acid metabolism, and the PPAR signaling pathway. An interaction network was constructed with 30 nodes, and CYP2E1 and CYP2C70 were identified as key nodes. RT-PCR validation results showed that the expression changes of CYP450 subtypes and lipid metabolism-related genes were consistent with the findings of sequencing. Conclusion: The CYP450 family plays a vital role in the pathogenesis of fatty liver by regulating lipid metabolism-related pathways, including oxidative stress, arachidonic acid metabolism, steroid hormone metabolism , and fatty acid metabolism.

[Role of CD36 in nonalcoholic fatty liver disease].

Nonalcoholic fatty liver disease (NAFLD) includes nonalcoholic simple fatty liver, nonalcoholic steatohepatitis, liver cirrhosis, and liver cancer and is the most common liver disease in the world. The complex pathogenesis of NAFLD is a major concern among researchers. CD36 is a transmembrane glycoprotein that takes up fatty acid and binds to oxidized low-density lipoprotein in the liver, and therefore, it is involved in the development and progression of NAFLD. With reference to the latest research findings, this article reviews the association between CD36 and NAFLD and the role of CD36.

Siglec-7 Defines a Highly Functional Natural Killer Cell Subset and Inhibits Cell-Mediated Activities.

Sialic acid-binding immunoglobulin-like lectin-7 (Siglec-7) is an inhibitory receptor expressed on natural killer (NK) cells. In this study, we investigated the relationship between Siglec-7 expression and NK cell functions. Siglec-7 was highly expressed on NK cells and was preferentially expressed by mature NK cells from peripheral blood of healthy adults. Siglec-7(+) NK cells displayed higher levels of activating receptors CD38, CD16, DNAM1, NKp30 and NKp46, but lower levels of inhibitory receptors such as NKG2A and CD158b, compared with Siglec-7(-) NK cells. Functional tests showed that Siglec-7(+) NK cells displayed more CD107a degranulation and IFN-γ production than Siglec-7(-) NK cells. Siglec-7 inhibited NK cell functions when interacting with specific antibodies. These data suggest that Siglec-7 defines a highly functional NK cell subset and suppresses NK cell-mediated functions when cross-linked with specific antibodies.

Anti-D alloimmunisation in pregnant women with DEL phenotype in China.

OBJECTIVES: To analyse anti-D alloimmunisation in pregnant women with D-elute (DEL) phenotype in China, for developing a predictive model to evaluate whether a person with the DEL phenotype can receive RhD-positive blood. BACKGROUND: Alloanti-D acquired by pregnancy or transfusion is one of the major causes of both haemolytic disease among newborns and haemolytic transfusion reactions. To date, there is little data available about the antigenic properties and immunogenicity of extremely weak D variants known as DEL. METHODS: RHD genotyping and D epitope mapping were performed using gene sequencing and comprehensive immunohaematological methods, respectively. DEL pregnant women carrying an RhD-positive fetus were tested for the presence of alloanti-D. RESULTS: A total of 130 of 142 (91·5%) pregnant women with a DEL phenotype were confirmed to carry the RHD (K409K) allele. Among 12 DEL women who appeared to have RHD-CE-D hybrid alleles, there were 1 RHD-CE (4-7)-D, 7 RHD-CE(4-9)-D, and 4 RHD-CE (2-5)-D alleles. Alloanti-D antibodies were detected in 6 of 142 DEL women, and all the six women had the partial DEL phenotype. CONCLUSION: The data indicate that partial DEL women appear at risk of alloimmunization to the D antigen. RhD immune globulin prophylaxis is necessary for partial DEL women. Partial DEL patients should receive only RhD-negative RBCs, whereas DEL patients with complete expression of antigen can safely receive RhD-positive RBCs.

Gene therapy with CX3CL1/Fractalkine induces antitumor immunity to regress effectively mouse hepatocellular carcinoma.

CX3CL1/Fractalkine(FK), a chemokine existing in both secreted and membrane anchored form, was reported to induce suppressive activities in tumor models. Here, we demonstrate for the first time the antitumor effects of FK in murine hepatocellular carcinoma (HCC) by constructing a FK eukaryotic expression vector (pIRES-FK) and transferring it into such tumor cells. Tumor rejection experiments were performed by injecting FK gene-modified murine HCC cell line (MM45T.Li) into immunocompetent mice, which significantly inhibited tumorigenicity or growth of MM45T.Li-FK cells. Immunohistochemistry examination and fluorescence-activated cell sorting analyses revealed both CD4+ and CD8+ T cells infiltration within the tumor together with a marked increase of these cells in the peripheral blood. Splenic lymphocyte from mice treated with MM45T.Li-FK were effective in the induction of tumor-specific cytotoxic T cells. We also observed an increased production of IL-2 and IFN-gamma in MM45T.Li-FK tumor tissue. Our results suggest that transfer of the FK gene into tumor cells could elicit a specific antitumor immunity capable of inhibiting tumor growth which lead to increased survival of tumor-bearing hosts. FK should be considered as a chemokine suitable for cancer immunoprevention or gene therapy.

Conjunctivitis caused by Thelazia callipaeda infestation in a woman.

Thelazia is a nematode (Spirurida) that can parasitize the mammalian conjunctival sac. This is the first reported case of ocular. Thelazia callipaeda infestation in Taiwan. A 41-year-old woman experienced swelling, itching sensation and occasional blurred vision of the right eye 2 weeks after a small group of flies swarmed her eye while she was hiking. Her symptoms were first misdiagnosed as allergic conjunctivitis at a local medical clinic. During her first visit to our outpatient department, five white thread-like living worms were discovered on the superior and inferior fornices. The worms were cream-colored, slender and approximately 1 cm in length. Follicular and papillary conjunctivitis was noted in her right eye. After removing the worms, the symptoms resolved and no other worms were found in the following 2 months. This case is a remainder to physicians that parasitic infestation should be included in the differential diagnoses of ocular itching, conjunctivities, and blurred vision after insect contact.

Separation of different receptor-mediated effects of a prostaglandin H2 analogue (U46619) on human platelets by means of human granulocytic elastase and chymotrypsin.

Previous investigations indicated two classes of thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptors on human platelets and suggested that shape change and myosin light chain phosphorylation correlated with the occupancy of high affinity receptors while serotonin release was related to a putative low affinity binding component (Morinelli TA et al., Am J Physiol 253: H1035-H1043, 1987). The current study shows that chymotrypsin destroyed three receptor-mediated responses of platelets to U46619 (a TXA2/PGH2 agonist), i.e. shape change, myosin light chain phosphorylation and serotonin release. Human granulocyte elastase selectively inactivated platelet ability to release serotonin following stimulation with U46619, but it did not affect significantly shape change and myosin light chain phosphorylation. In conclusion, it is possible to separate different receptor-mediated effects of U46619 on human platelets by means of human granulocytic elastase and chymotrypsin.

Environmental factors in the etiology of Parkinson's disease.

Parkinson's disease (PD) has been proposed to result from the interaction of aging and environment in susceptible individuals. Defective metabolism of debrisoquine, inherited as an autosomal recessive, has been associated with this susceptibility. In 35 PD patients and 19 age-matched controls, no significant differences in debrisoquine metabolism were found, although a trend to impaired metabolism was noted in patients with disease onset less than or equal to 40. Foci of PD patients were associated with rural living and well water drinking, or rural living coupled with market gardening or wood pulp mills. In a questionnaire survey, patients with PD onset less than or equal to age 47 were significantly more likely to have lived in rural areas and to have drunk well water than those with onset greater than or equal to age 54 (p less than or equal to 0.01). Because of population mobility in North America, a case-control study designed to test environmental, occupational, dietary and other proposed risk factors for PD was conducted in China, where the population is more stationary and the environment more stable. No significant differences in incidences of head trauma, smoking or childhood measles were found between patients and controls.