Bosentan and ambrisentan in the treatment of idiopathic pulmonary fibrosis: a meta-analysis.

OBJECTIVE: The aim is to showcase the effectiveness and safety of bosentan or ambrisentan in individuals diagnosed with idiopathic pulmonary fibrosis (IPF) and offer fresh evidence for the management of this condition. MATERIALS AND METHODS: For this research, we conducted a meta-analysis of randomized controlled trials by searching various databases, including the Cochrane Library, Excerpta Medica Database, PubMed, and Web of Science. The retrieval was conducted until November 2021. We analyzed the variances in 6-minute walk distance (6MWD), death, diffusion capacity for carbon monoxide (DLCO), forced vital capacity (FVC), hospitalization, IPF worsening, mean pulmonary arterial pressure, serious adverse events (SAEs), Short Form-36 improved, and St. George's Respiratory Questionnaire between the treatment and control groups. RESULTS: A sum of six studies involving 1,928 participants were found to meet the inclusion criteria. The quality of evidence was high. The control group had significantly higher values for 6MWD, DLCO, and FVC compared to the ambrisentan treatment group. The rates of hospitalization and IPF worsening were considerably greater in comparison with the control group. The bosentan group exhibited significantly reduced rates of hospitalization and IPF worsening in comparison with the control group. Both drugs did not cause any raising in death or SAEs when in comparison with the control group. CONCLUSIONS: The findings of this research validate the effectiveness and safety of bosentan for treating IPF patients. This medication can enhance the quality of life for individuals with IPF without causing any significant increase in SAEs. However, it does not have a notable influence on the long-term prognosis. The findings of this research do not endorse the utilization of ambrisentan in individuals diagnosed with IPF.

[Association between cognitive function and probability of prodromal Parkinson's disease in middle aged and elderly people aged 55 years and above in 4 provinces in China].

Objective: To analyze probability of prodromal Parkinson's disease (pPD) and assess the association between global cognitive function and cognitive domain function and probability of pPD in ≥55 years old middle-aged and elderly people in Hebei, Zhejiang, Shaanxi and Hunan Provinces in China. Methods: Data were collected from dataset of the Community-based Cohort Study on Nervous System Disease 2020. We selected 4 634 Alzheimer disease and Parkinson's disease free persons aged ≥55 years with completed information on demographics, disease history, cognitive test, and risk factors of Parkinson's disease for this study. Cognitive function was assessed using Montreal Cognitive Assessment Scale (Chinese version). Calculation of probability of pPD and assessment of possible/probable pPD were performed according to the criteria published by the International Parkinson and Movement Disorder Society. Multivariate linear regression model was used to analyze the association between cognitive function and probability of pPD. Results: The M (Q1,Q3) of global cognitive function and cognitive domains in terms of memory, execution, visuospatial function, language, attention and orientation were 25 (20, 30), 13 (11, 15), 10 (7, 12), 6 (4, 7), 5 (4, 6), 15 (12, 18) and 6 (6, 6) points, respectively. The M(Q1,Q3) of probability of pPD was 0.42% (0.80%, 1.73%), and the proportion of the study subjects with possible/probable pPD was 0.4%. Differences in the distribution of probability of pPD were significant among groups by total cognitive score quartiles (P<0.001), and the difference in proportions of study subjects with possible/probable pPD was significant and showed decline trend (P=0.001). After adjusted for confounders, the results of multivariate linear regression analyses showed that probability of pPD in the Q2, Q3 and Q4 group decreased by 23.4%, 31.2% and 20.1% compared with Q1 group, and corresponding ß values were 0.766 (95%CI: 0.702-0.836), 0.688 (95%CI: 0.631-0.751) and 0.799 (95%CI: 0.730-0.875), respectively, the trend was significant (P<0.001). Higher index scores of execution, visuospatial function, language, attention and orientation were highly related to lower probability of pPD (P<0.001). Conclusion: Declines in global cognitive function and cognitive domains of execution, visuospatial function, language, attention and orientation might increase the probability of pPD in middle-aged and elderly people, suggesting the importance of cognitive intervention in early stage for pPD prevention.

[Epidemiological characteristics of cardio-metabolic risk factors among children and adolescents aged 7-17 years in 4 provinces of China].

Objective: This study aimed to investigate the epidemiological characteristics of cardio-metabolic risk factors among children and adolescents aged 7-17 years in (Hebei, Zhejiang, Shaanxi, Hunan) 4 provinces of China and the influence of demographic and economic characteristics on them. Methods: A total of 1 747 children and adolescents aged 7-17 from a Community-based Cohort Study on Nervous System Disease in 2018 were selected. High waist circumference, central obesity, elevated TG, elevated TC, elevated LDL-C, decreased HDL-C, elevated blood pressure, elevated blood glucose, and clustering of risk factors was analyzed. χ2 test was used for univariate analysis, multivariate logistic regression was used to analyze the correlation between demographic and economic factors and risk factors, and the Cochran-Armitage trend test was used for trend analysis. Results: The detection rates of high waist circumference, decreased HDL-C, elevated blood pressure, elevated TG, elevated blood glucose, central obesity, elevated TC, and elevated LDL-C were 29.08%, 15.28%, 13.17%, 13.05%, 11.79%, 7.33%, 6.53%, and 5.15%, respectively. The rate of clustering of risk factors was 18.37%. Multivariate logistic regression analysis showed that the risk of high waist circumference in girls was higher than that in boys (OR=1.67, 95%CI: 1.26-2.22), and the risk of elevated blood glucose and clustering of risk factors was lower than that in boys (OR=0.69, 95%CI: 0.49-0.99; OR=0.72, 95%CI: 0.53-0.99). The risk of high waist circumference, decreased HDL-C, and clustering of risk factors in 13-17 years old group was higher than that in the 7-year-olds group (OR=2.24, 95%CI: 1.65-3.04; OR=1.59, 95%CI: 1.20-2.11; OR=1.75, 95%CI: 1.26-2.44), but the risk of central obesity was lower (OR=0.54, 95%CI: 0.37-0.78). The risk of elevated TC, elevated TG, and decreased HDL-C in children and adolescents in southern was higher than that in northern parts of China (OR=1.88, 95%CI: 1.25-2.83; OR=1.61, 95%CI: 1.17-2.22; OR=1.55, 95%CI: 1.19-2.04), but the risk of high waist circumference and central obesity was lower than that in northern China (OR=0.57, 95%CI: 0.43-0.75; OR=0.62, 95%CI: 0.42-0.90). The risk of decreased HDL-C in rural children and adolescents was higher than in urban children and adolescents (OR=1.36, 95%CI: 1.02-1.83). The risk of multiple risk factors increased with the increase in average monthly household income per capita and BMI level. Conclusions: High waist circumference, decreased HDL-C and elevated blood pressure were prominent cardio-metabolic risk factors among children and adolescents aged 7-17 years in 4 provinces of China in 2018. The region, average monthly household income per capita, and BMI were the main influencing factors of cardio-metabolic risk factors.

[Relationship between nutrient-related dietary pattern and mild cognitive impairment in middle-aged and elderly people in 15 provinces of China].

Objective: To explore the relationship between nutrient-related dietary pattern and mild cognitive impairment (MCI) in middle-aged and elderly people. Methods: A total of 6 444 middle-aged and elderly people aged ≥55 years were selected in 2018 China Health and Nutrition Survey. MCI was evaluated by Mini-Mental State Examination, and the intakes of various foods were obtained by consecutive 3-day 24-hour dietary survey and weighing method. The intakes of various nutrients and total dietary energy were calculated based on the food composition table. Demographic and social information, lifestyle and health status of the respondents were obtained through questionnaire survey and physical measurements. In this study, vitamin C, vitamin E, zinc, iron, copper and selenium were selected as dependent variables. Nutrient-related dietary patterns were extracted by reduced rank regression method, and the relationship between dietary patterns and MCI was analyzed by multivariate logistic regression model. Results: Six dietary patterns were extracted in this study, and dietary pattern 1 with the highest explanatory degree was selected for subsequent analysis. Dietary pattern 1 was characterized by higher intakes of legume products, vegetables, fruits, nuts, pork, aquatic products and plant oil. Multivariate logistic regression analysis showed that the risk of MCI was lower in Q4 dietary score group than in Q1 dietary score group (OR=0.69, 95%CI: 0.49-0.98) in the 55-64 age group. In people with sleep duration of 8 hours per day, the risk of MCI was reduced in Q2, Q3 and Q4 dietary score groups compared with the Q1 dietary score group, with OR values of 0.68 (95%CI: 0.51-0.92), 0.67 (95%CI: 0.49-0.92) and 0.65 (95%CI: 0.45-0.92), respectively. Interaction analysis showed that the risk for MCI increased in those aged 65-74 years and ≥75 years compared with those aged 55-64 years in Q1 dietary score group. However, the risk for MCI decreased in both age groups as dietary pattern scores increased. Compared with those with sleep duration less or more than 8 hours per day in Q1 dietary score group, those with sleep duration of 8 hours per day in Q2 and Q3 dietary score groups had a reduced risk for MCI. Conclusion: Dietary patterns with higher intakes of legume products, vegetables, fruits, nuts, pork, aquatic products, and plant oil are negatively associated with MCI in people aged 55-64 years and those who slept 8 hours per day, and may reduce the risk of MCI with aging.

[Association between fasting plasma glucose and mild cognitive impairment in Chinese 55 and older population from four provinces].

Objective: To analyze the association of fasting plasma glucose (FPG) with mild cognitive impairment (MCI) in the Chinese middle-aged and elderly population from four provinces. Methods: Data were drawn from the baseline data of the Community-based Cohort Study on Nervous System Disease 2018-2019. We selected 3 272 subjects aged 55 and above with completed information on demographics, lifestyle, disease history, cognitive test, psychological assessment, and bio-chemistries measurement, and who were capable of performing basic activities of daily living but without Alzheimer's disease during recruitment. A multivariate logistic regression model was employed to analyze the association between FPG and MCI. Results: Median level of FPG in the study population was 5.5 mmol/L. The prevalence of MCI was 24.8%, and those in groups of the FPG quintile were 19.4%, 22.2%, 29.2%, 26.6%, and 26.1%, respectively, which significantly increased the trend (P=0.002). After adjustment of confounders, multivariate logistic regression analysis found that the MCI risk of subjects in the Q3,Q4 and Q5 groups was 1.641 (95%CI: 1.226-2.131), 1.373 (95%CI: 1.036-1.825), 1.402 (95%CI: 1.054-1.871) times as high as that in the Q1 group, respectively. Conclusion: High FPG level might serve as a risk factor for MCI in the middle-aged and elderly population, suggesting the importance of monitoring and controlling plasma glucose even without diabetes.

[Changing trends regarding the rates of prevalence, awareness and treatment of hypertension and the differences by demographic and economic factors, among adult farmers in nine provinces in China, from 1991 to 2015].

Objective: To analyze the changes on the rates of prevalence, awareness and treatment of hypertension as well as the differences of the disease by demographic and economic factors, among adult farmers in nine provinces of China. Methods: Adult farmers, (including fishermen and hunters) with completed data on demographics, socio-economic characteristics, disease histories and physical measurements were selected from the 1991-2015 China Health and Nutrition Survey. Hypertension was defined based on the Chinese guidelines. Multivariate logistic regression was used to analyze the influence of demographic and economic factors on the rates of prevalence, awareness and treatment of hypertension among those adult farmers in 2015. Results: A total of 18 236 participants were included. From 1991 to 2015, rates of prevalence, awareness and treatment of hypertension among the adult farmers in nine provinces all significantly increased (P<0.05). Results from the multivariate analysis showed that farmers aged ≥45 years were 98% more likely to suffer from hypertension than those aged 18-44 years. Farmers who were overweight or obese were 1.58 times and 5.21 times more likely to suffer from hypertension than those in the control group (BMI<24.0 kg/m(2)), respectively. The rates on awareness of hypertension among farmers with junior high school education (OR=0.23) or above (OR=0.12) or with junior high school education (OR=0.30) were both lower than those with primary school education or below. Rates on the awareness and treatment of hypertension in obese farmers were 5.77 times and 7.52 times of those in the control group. Conclusions: The rates of prevalence of hypertension showed increasing trends during 1991-2015, with a slower increase in the rates of awareness and treatment in the farmers. Age ≥45 year-olds, and being obese were the risk factors for farmers to have hypertension, which suggested the above population should be focused on hypertension prevention strategy and practice.

[Dietary sodium intake of adult residents in 15 provinces of China in 2015].

Objective: To analyze the status of dietary sodium intake of Chinese adult residents in fifteen provinces in 2015. Methods: Data were collected from 2015 China Nutrition Transition Cohort Study. This cohort study used a three consecutive 24-h retrospective method to record food intake and weighing method to record household condiment consumption. In this study, 14 847 residents aged 18 years and over with complete data from 15 provinces in 2015 were selected for the comparison of dietary sodium intake (median) with different characteristics. Results: Among the 14 847 residents, 47.1% were males, and the rural and northern residents accounted for 60.1% and 37.7%, respectively. Median sodium intake was 3 960.0 mg/d among residents in 2015. The sodium intake of males (4 272.1 mg/d) was higher than that of females (3 716.6 mg/d). Across age subgroups, sodium intake was highest among residents aged 45-59 years (4 257.0 mg/d; 18-44 years old, 3 867.1 mg/d; ≥60 years old, 3 799.0 mg/d). Sodium intake was higher in rural area (4 042.9 mg/d) than in urban area (3 866.8 mg/d), higher in north (4 229.2 mg/d) than in south (3 806.8 mg/d) (all P values <0.05). 11.8% of residents with dietary sodium intake were below 2 000 mg/d. The main sources of dietary sodium were condiments (79.4%), regular cooking foods (11.9%) and processed foods (8.7%). Among the condiments, the salt and soy sauce accounted for 63.6% and 10.4%, respectively. Conclusion: In 2015, Chinese adult residents had higher dietary sodium intake with gender and regional differences. Condiments were the main source of dietary sodium.

[Research progress on the relationship between dietary nutrition, lifestyle and depression].

Depression jeopardizes human health and brings heavy burden to both related families and societies. However, pathogenesis of depression has not been fully clarified yet. Previous studies show that there are some connections seen between dietary factors and depression, which are affected by various lifestyles. This paper aims at providing evidence for the prevention and treatment of depression by evaluating the relationships between factors as nutrients, dietary patterns, lifestyle and depression, based on the published literature.

Synthesis of 2,4-dihydroxychalcone derivatives as potential antidepressant effect.

In this study, twelve 2,4-dihydroxychalcone derivatives were synthesized and evaluated for antidepressant activities using the forced swimming test (FST). The pharmacological test showed that 6 compounds significantly reduced the immobility times in the FST at a dose of 10 mg/kg, indicative of antidepressant activity. Among the derivatives, compounds designated 3d and 3 h exhibited the best antidepressant activity, with reduced immobility time by 32.05% and 34.33%, respectively. In the 5-hydroxytryptophan-induced head-twitch test and yohimbine-induced mortality test, compounds 3d and 3 h increased head-twitch and increased the mortality rate. The mechanisms of the antidepressant effects of compounds 3d and 3 h may be related with the 5-HTP and NE nervous system.

Effect of an interferon-stimulated response element (ISRE) mutant of porcine circovirus type 2 (PCV2) on PCV2-induced pathological lesions in a porcine reproductive and respiratory syndrome virus (PRRSV) co-infection model.

Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus-associated diseases (PCVAD) in swine. Coinfections of PCV2 with other swine pathogens increase the severity of PCVAD. Induction of proinflammatory cytokines by coinfecting pathogens may attribute to the exacerbation of PCVAD during coinfections. An interferon-stimulated response element (ISRE) sequence was identified in the origin of replication of PCV2 genome. To assess the role of ISRE in PCV2 pathogenesis during coinfection, an ISRE-mutant PCV2 was constructed and used to experimentally infect pigs with either ISRE mutant or wildtype PCV2 singly or in combination with porcine reproductive and respiratory syndrome virus (PRRSV). The results showed that, during early stage of infection at 14 days post-inoculation (dpi), the ISRE mutation reduced viral replication and elicited low antibody responses. However, at 28 dpi viremia in pigs infected with the ISRE-mutant was on an upward trend, and microscopic lesion scores in pigs inoculated with the ISRE-mutant were significantly more severe than in wildtype PCV2-infected pigs. Coinfection with PRRSV caused an opposite shift in the in vivo dynamics of the ISRE-mutant at 14 dpi with the lymph node histopathological lesions being significantly more severe in pigs coinfected with the ISRE-mutant PCV2 and PRRSV than in pigs coinfected with wildtype PCV2 and PRRSV. PCV2 genomic copy numbers in pigs coinfected with ISRE-mutant and PRRSV were also higher than those coinfected with wildtype PCV2 and PRRSV. The results suggested that the ISRE element in PCV2 genome may play a potential role in viral pathogenesis.

Interferon-mediated enhancement of in vitro replication of porcine circovirus type 2 is influenced by an interferon-stimulated response element in the PCV2 genome.

Porcine circovirus type 2 (PCV2) is an economically important swine pathogen. It has been shown that treatment of PCV2-infected cells with interferon gamma (INF-gamma) or alpha (IFN-alpha) increases PCV2 replication in vitro, and that an interferon-stimulated response element (ISRE)-like sequence was identified in the PCV2 genome. To determine if the ISRE is involved in viral response to IFNs, several ISRE mutants of PCV2 were created by serial mutations of the ISRE sequence. Treatment of ISRE mutants-infected cells with IFN-gamma or IFN-alpha showed a progressive diminishment in the enhanced viral replication in correlation with increasing alterations to the ISRE sequence. To determine if the ISRE was necessary and sufficient for IFN-mediated enhancement of PCV2 replication, DNA fragments spanning the ISRE-containing promoter region of the rep gene from wildtype and ISRE-mutant PCV2 were tested in a luciferase reporter gene system. 3D4/31 cells transfected with reporter gene constructs were treated with IFN-gamma or IFN-alpha, respectively. The results showed that the untreated controls for both ISRE-mutant and wildtype PCV2 had higher levels of luciferase reporter activity than IFN-treated samples, indicating that, when removed from the context of whole viral genome, the ISRE-like activity of the sequence was lost. Furthermore, treatment with IFNs diminished the promoter activity regardless of the mutation, suggesting that other cis elements in the viral genome may be required for regulating the ISRE-mediated gene transcription. In conclusion, the PCV2 ISRE, when present in the context of intact virus but not in isolation, influences the interferon-mediated enhancement of PCV2 replication in vitro.

Identification of two neutralization epitopes on the capsid protein of avian hepatitis E virus.

Avian hepatitis E virus (avian HEV) is genetically and antigenically related to human HEV, the causative agent of hepatitis E. To identify the neutralizing epitopes on the capsid (ORF2) protein of avian HEV, four mAbs (7B2, 1E11, 10A2 and 5G10) against recombinant avian HEV ORF2 protein were generated. mAbs 7B2, 1E11 and 10A2 blocked each other for binding to avian HEV ORF2 protein in a competitive ELISA, whereas 5G10 did not block the other mAbs, suggesting that 7B2, 1E11 and 10A2 recognize the same or overlapping epitopes and 5G10 recognizes a different one. The epitopes recognized by 7B2, 1E11 and 10A2, and by 5G10 were mapped by Western blotting between aa 513 and 570, and between aa 476 and 513, respectively. mAbs 1E11, 10A2 and 5G10 were shown to bind to avian HEV particles in vitro, although only 5G10 reacted to viral antigens in transfected LMH cells. To assess the neutralizing activities of the mAbs, avian HEV was incubated in vitro with each mAb before inoculation into specific-pathogen-free chickens. Both viraemia and faecal virus shedding were delayed in chickens inoculated with the mixtures of avian HEV and 1E11, 10A2 or 5G10, suggesting that these three mAbs partially neutralize avian HEV.

Association of hepatitis E virus (HEV) and postweaning multisystemic wasting syndrome (PMWS) with lesions of hepatitis in pigs.

The aim of the study was to determine the presence of swine hepatitis E virus (HEV) RNA and antibodies in postweaning multisystemic wasting syndrome-affected (n=114) and non-affected (n=46) pigs and the possible association with hepatitis lesions. Forty-four pigs were RT-PCR positive (28.2%); 25 of them were PMWS cases, while 19 were non-PMWS pigs. In both groups, HEV RT-PCR results were associated with hepatitis (OR=5.61 for PMWS-affected pigs and OR=5.17 for non-PMWS affected pigs; p=0.01). No interaction was detected in a logistic regression between PMWS occurrence and HEV infection for the development of hepatitis lesions. Seropositivity to HEV was more likely to occur in pigs with hepatitis (51.9%) compared to pigs without hepatitis (36.1%; p=0.03). Significant differences in optical densities were notices comparing the lesional stage of pigs (p=0.009). While pigs with slight or moderate hepatitis were seropositive, pigs with more severe lesions were seronegative to HEV. These results indicate that swine HEV infection can be a significant contributor to the development of moderate hepatitis in pigs regardless of the PMWS status.

Infectious swine hepatitis E virus is present in pig manure storage facilities on United States farms, but evidence of water contamination is lacking.

Fresh feces, manure slurry (from earthen lagoons and/or concrete pits), and drinking and surface water samples were collected from 28 pig farms in the Midwestern United States. All samples were tested for hepatitis E virus (HEV) RNA by reverse transcription-PCR. Seven of 28 farms had fecal samples that contained HEV. Of 22 farms where pit samples were accessible, 15 contained HEV, and of 8 farms that had lagoons, 3 contained HEV. The highest virus titers were 10 and 10(3) genome equivalents per 60 ml of manure slurry in lagoon and pit samples, respectively. None of the water samples tested HEV positive. To determine the infectivity of the HEV found in the positive farm 19 lagoon (designated L19) or farm 12 pit (designated P12) samples, pigs were inoculated either intravenously (n = 3) or orally (n = 3) with the L19 or P12 manure slurry. Four pigs inoculated intravenously with prototype swine HEV served as positive controls. All positive-control pigs shed HEV in feces and 3 of 4 developed anti-HEV antibodies. Two pigs in the intravenously inoculated P12 group shed HEV in feces, and one of the pigs seroconverted to anti-HEV antibodies. None of the pigs in the negative-control, L19 oral, L19 intravenous, or P12 oral group shed HEV in feces. The findings indicate that HEV found in pig manure slurry was infectious when inoculated intravenously. Pit manure slurry is a potential source of HEV infection and for contamination of the environment. Contamination of drinking or surface water with HEV was not found on or near the pig farms.

Construction and characterization of infectious cDNA clones of a chicken strain of hepatitis E virus (HEV), avian HEV.

Hepatitis E virus (HEV), the causative agent of hepatitis E, is an important human pathogen. Increasing evidence indicates that hepatitis E is a zoonosis. Avian HEV was recently discovered in chickens with hepatitis-splenomegaly syndrome in the USA. Like swine HEV from pigs, avian HEV is also genetically and antigenically related to human HEV. The objective of this study was to construct and characterize an infectious cDNA clone of avian HEV for future studies of HEV replication and pathogenesis. Three full-length cDNA clones of avian HEV, pT7-aHEV-5, pT7G-aHEV-10 and pT7G-aHEV-6, were constructed and their infectivity was tested by in vitro transfection of leghorn male hepatoma (LMH) chicken liver cells and by direct intrahepatic inoculation of specific-pathogen-free (SPF) chickens with capped RNA transcripts from the three clones. The results showed that the capped RNA transcripts from each of the three clones were replication competent when transfected into LMH cells as demonstrated by detection of viral antigens with avian HEV-specific antibodies. SPF chickens intrahepatically inoculated with the capped RNA transcripts from each of the three clones developed active avian HEV infections as evidenced by seroconversion to avian HEV antibodies, viraemia and faecal virus shedding. The infectivity was further confirmed by successful infection of naïve chickens with the viruses recovered from chickens inoculated with the RNA transcripts. The results indicated that all three cDNA clones of avian HEV are infectious both in vitro and in vivo. The availability of these infectious clones for a chicken strain of HEV now affords an opportunity to study the mechanisms of HEV cross-species infection and tissue tropism by constructing chimeric viruses among human, swine and avian HEVs.

Identification of genotype 3 hepatitis E virus (HEV) in serum and fecal samples from pigs in Thailand and Mexico, where genotype 1 and 2 HEV strains are prevalent in the respective human populations.

Hepatitis E virus (HEV), the causative agent of hepatitis E, is an important public health concern in many developing countries. Increasing evidence indicates that hepatitis E is a zoonotic disease. There exist four major genotypes of HEV, and HEV isolates identified in samples from pigs belong to either genotype 3 or 4. Genotype 1 and 2 HEVs are found exclusively in humans. To determine whether genotype 1 and 2 HEVs also exist in pigs, a universal reverse transcription-PCR assay that is capable of detecting all four HEV genotypes was used to test for the presence of HEV RNA in serum and/or fecal samples from pigs in Thailand, where genotype 1 human HEV is prevalent, and from pigs in Mexico, where genotype 2 human HEV was epidemic. In Thailand, swine HEV RNA was detected in sera from 10/26 pigs of 2 to 4 months of age but not in sera from 50 pigs of other ages. In Mexico, swine HEV RNA was detected in 8/125 sera and 28/92 fecal samples from 2- to 4-month-old pigs. Antibodies to swine HEV were also detected in about 81% of the Mexican pigs. A total of 44 swine HEV isolates were sequenced for the open reading frame 2 gene region. Sequence analyses revealed that all swine HEV isolates identified in samples from pigs in Thailand and Mexico belong to genotype 3. Phylogenetic analyses revealed that minor branches associated with geographic origin exist among the swine HEV isolates. The results indicated that genotype 1 or 2 swine HEV does not exist in pigs from countries where the respective human HEV genotype 1 or 2 is prevalent. It is likely that only genotype 3 and 4 HEV strains have zoonotic potential.

Systematic pathogenesis and replication of avian hepatitis E virus in specific-pathogen-free adult chickens.

Hepatitis E virus (HEV) is an important human pathogen. Due to the lack of a cell culture system and a practical animal model for HEV, little is known about its pathogenesis and replication. The discovery of a strain of HEV in chickens, designated avian HEV, prompted us to evaluate chickens as a model for the study of HEV. Eighty-five 60-week-old specific-pathogen-free chickens were randomly divided into three groups. Group 1 chickens (n=28) were each inoculated with 5 x 10(4.5) 50% chicken infectious doses of avian HEV by the oronasal route, group 2 chickens (n=29) were each inoculated with the same dose by the intravenous (i.v.) route, and group 3 chickens (n=28) were not inoculated and were used as controls. Two chickens from each group were necropsied at 1, 3, 5, 7, 10, 13, 16, 20, 24, 28, 35, and 42 days postinoculation (dpi), and the remaining chickens were necropsied at 56 dpi. Serum, fecal, and various tissue samples, including liver and spleen samples, were collected at each necropsy for pathological and virological testing. By 21 dpi, all oronasally and i.v. inoculated chickens had seroconverted. Fecal virus shedding was detected variably from 1 to 20 dpi for the i.v. group and from 10 to 56 dpi for the oronasal group. Avian HEV RNA was detected in serum, bile, and liver samples from both i.v. and oronasally inoculated chickens. Gross liver lesions, characterized by subcapsular hemorrhages or enlargement of the right intermediate lobe, were observed in 7 of 28 oronasally and 7 of 29 i.v. inoculated chickens. Microscopic liver lesions were mainly lymphocytic periphlebitis and phlebitis. The lesion scores were higher for oronasal (P=0.0008) and i.v. (P=0.0029) group birds than for control birds. Slight elevations of the plasma liver enzyme lactate dehydrogenase were observed in infected chickens. The results indicated that chickens are a useful model for studying HEV replication and pathogenesis. This is the first report of HEV transmission via its natural route in a homologous animal model.

Routes of transmission of swine hepatitis E virus in pigs.

Hepatitis E virus (HEV) is believed to be transmitted by the fecal-oral route in pigs. To date, in experiments, HEV has been transmitted successfully only by the intravenous or intrahepatic route. To assess the route of HEV transmission, 27 pigs were separated into nine groups of three pigs. Positive-control pigs were inoculated intravenously with swine HEV and served as the source of HEV for the other groups. Uninoculated contact pigs were placed in the positive-control group. On three consecutive days, naive pigs were inoculated using samples collected from the positive-control pigs at 9, 10, and 11 days postinoculation. The tonsils and nasal mucosa of each positive-control pig were swabbed and that swab was used to rub the tonsils and nasal and ocular mucosa of naive pigs. The positive-control pigs were also injected with bacterin, and the same needle was used to immediately inject naive pigs. Feces were collected from positive controls and fed by oral gavage to naive pigs. Weekly fecal and serum samples from each pig were tested for anti-HEV antibodies and HEV RNA. All positive-control pigs shed the virus in feces; two pigs were viremic and seroconverted to anti-HEV. All contact control pigs shed the virus in feces; two seroconverted and one became viremic. One of three pigs in the fecal-oral exposure group shed the virus in feces and seroconverted. Pigs exposed to the contaminated needles or the tonsil and nasal secretion swabs remained negative. This is the first report of experimental fecal-oral transmission of HEV in swine.

Generation and infectivity titration of an infectious stock of avian hepatitis E virus (HEV) in chickens and cross-species infection of turkeys with avian HEV.

Avian hepatitis E virus (HEV), a novel virus identified from chickens with hepatitis-splenomegaly syndrome in the United States, is genetically and antigenically related to human HEV. In order to further characterize avian HEV, an infectious viral stock with a known infectious titer must be generated, as HEV cannot be propagated in vitro. Bile and feces collected from specific-pathogen-free (SPF) chickens experimentally infected with avian HEV were used to prepare an avian HEV infectious stock as a 10% suspension of positive fecal and bile samples in phosphate-buffered saline. The infectivity titer of this infectious stock was determined by inoculating 1-week-old SPF chickens intravenously with 200 microl of each of serial 10-fold dilutions (10(-2) to 10(-6)) of the avian HEV stock (two chickens were inoculated with each dilution). All chickens inoculated with the 10(-2) to 10(-4) dilutions of the infectious stock and one of the two chickens inoculated with the 10(-5) dilution, but neither of the chickens inoculated with the 10(-6) dilution, became seropositive for anti-avian HEV antibody at 4 weeks postinoculation (wpi). Two serologically negative contact control chickens housed together with chickens inoculated with the 10(-2) dilution also seroconverted at 8 wpi. Viremia and shedding of virus in feces were variable in chickens inoculated with the 10(-2) to 10(-5) dilutions but were not detectable in those inoculated with the 10(-6) dilution. The infectivity titer of the infectious avian HEV stock was determined to be 5 x 10(5) 50% chicken infectious doses (CID(50)) per ml. Eight 1-week-old turkeys were intravenously inoculated with 10(5) CID(50) of avian HEV, and another group of nine turkeys were not inoculated and were used as controls. The inoculated turkeys seroconverted at 4 to 8 wpi. In the inoculated turkeys, viremia was detected at 2 to 6 wpi and shedding of virus in feces was detected at 4 to 7 wpi. A serologically negative contact control turkey housed together with the inoculated ones also became infected through direct contact. This is the first demonstration of cross-species infection by avian HEV.

Determination and analysis of the complete genomic sequence of avian hepatitis E virus (avian HEV) and attempts to infect rhesus monkeys with avian HEV.

Avian hepatitis E virus (avian HEV), recently identified from a chicken with hepatitis-splenomegaly syndrome in the United States, is genetically and antigenically related to human and swine HEVs. In this study, sequencing of the genome was completed and an attempt was made to infect rhesus monkeys with avian HEV. The full-length genome of avian HEV, excluding the poly(A) tail, is 6654 bp in length, which is about 600 bp shorter than that of human and swine HEVs. Similar to human and swine HEV genomes, the avian HEV genome consists of a short 5' non-coding region (NCR) followed by three partially overlapping open reading frames (ORFs) and a 3'NCR. Avian HEV shares about 50 % nucleotide sequence identity over the complete genome, 48-51 % identity in ORF1, 46-48 % identity in ORF2 and only 29-34 % identity in ORF3 with human and swine HEV strains. Significant genetic variations such as deletions and insertions, particularly in ORF1 of avian HEV, were observed. However, motifs in the putative functional domains of ORF1, such as the helicase and methyltransferase, were relatively conserved between avian HEV and mammalian HEVs, supporting the conclusion that avian HEV is a member of the genus Hepevirus. Phylogenetic analysis revealed that avian HEV represents a branch distinct from human and swine HEVs. Swine HEV infects non-human primates and possibly humans and thus may be zoonotic. An attempt was made to determine whether avian HEV also infects across species by experimentally inoculating two rhesus monkeys with avian HEV. Evidence of virus infection was not observed in the inoculated monkeys as there was no seroconversion, viraemia, faecal virus shedding or serum liver enzyme elevation. The results from this study confirmed that avian HEV is related to, but distinct from, human and swine HEVs; however, unlike swine HEV, avian HEV is probably not transmissible to non-human primates.