大理地区猪源甲型、乙型、戊型肝炎病毒血清流行病学调查

目的:调查大理地区猪体内甲、乙、戊型肝炎病毒的感染情况。方法:采用酶联免疫吸附实验(ELISA)检测屠宰生猪血清标本甲肝血清标志物(HAV-lgG和HAV-lgM)、乙肝血清标记物(HBsAg,HBsAb,HBeAg,HBeAbHBcAb)、戊肝血清标志物(HEV-lgG和HEV-lgM)。结果:HAV、HBV和HEV的感染率分别为:91%(162/178),93.9%(185/197),23.6%(42/178);HAV和HBV二重感染率为67.97%(121/178);HAV、HBV和HEV三重感染率为20.2%(36/178);HAV和HEV二重感染率为1.7%(3/178);HBV和HEV二重感染率为2.2%(4/178)。结论:甲、乙、戊型肝炎病毒在猪体内存在感染,同时发现在猪体内甲、乙型肝炎病毒重叠感染常见。     

HIV-1 RNA levels and development of clinical disease in two different adolescent populations

HIV infection rates in American youth continue to increase unabated. As adolescent-specific therapeutic interventions are planned, information on HIV infection's course and its predictors becomes critically important for valid and precise study design. We report on age-specific disease rates stratified by estimated time since infected and predictors of HIV disease progression through four clinical categories in two distinct adolescent populations. Adolescents with hemophilia infected through contaminated blood products showed disease progression rates of 18 to 23 events per 100 person-years (PYs) by age and years infected. Predictors of first progression included HIV-1 RNA >30,000 copies/ml (rate ratio [RR], 2.4; 95% confidence interval [CI], 1.5-3.9), antiretroviral monotherapy (RR, 2.4; 95% CI, 1.7-3.3); Latino/a ethnicity (RR, 2.2; 95% CI, 1.2-4.2) and initial intermediate clinical status (RR, 1.9; 95% CI, 1.3-2.9). Sexually-infected adolescents >18 years who had been infected >3 to 6 years had a disease progression rate of 16 events per 100 PY. For these youths, the sole predictor of first progression was viral load (VL) (RR for VL >30,000 copies per ml, 8.4; 95% CI, 2.8-25.1). This article examines the predictive capacity of viral load and evaluates other cofactors for disease progression in different adolescent populations. These data will be of value in clinical trial design.     

Seroepidemiology of hepatitis E in selected Australian populations

The presence of hepatitis E virus-specific antibodies (anti-HEV) was determined in selected Australian groups. Anti-HEV was detected initially using a recombinant antigen-based enzyme immunoassay (EIA). It was found that 1 of 279 (0.4%) blood donors, 14 of 182 (7.7%) Indochinese refugees, 2 of 89 (2.2%) sera submitted for amoebic serology (generally people who had visited developing countries), 1 of 13 (7.7%) patients with non-A, non-B hepatitis, none of 7 (0%) patients with fulminant non-A, non-B hepatitis, and none of 33 (0%) control sera were repeatedly reactive by the HEV EIA. The positive sera were subjected to further testing using a supplemental immunoblot. Preliminary data suggest that while potentially large numbers of people infected with HEV are entering Australia, no compulsive evidence was found in these particular groups for endemic HEV infection in Australia. This is the first seroepidemiological survey of HEV in Australia. © 1995 Wiley-Liss, inc.     

Seroepidemiology of Campylobacter pylori infection in various populations.

Campylobacter pylori infection has been recognized as being strongly associated with chronic gastritis and duodenal ulceration, but the prevalence of C. pylori infection in a normal population is not known. A serological survey was conducted in four countries with different geographical and socioeconomic status, in a randomly chosen population as representative as possible, by using an enzyme-linked immunosorbent assay (ELISA) with a sonic extract of two strains as the antigen. The test had a specificity of 94% when 600 ELISA units was used as the threshold. In France, few children were infected before the age of 10 years. The prevalence then increased gradually to 36.7% in the sixth decade of life. This increasing prevalence of infection with age was also observed in Algeria, Vietnam, and the Ivory Coast but at a higher rate (80 to 90%). In Vietnam, as in France, few children were infected, whereas in Africa, C. pylori infection occurred earlier. The prevalence of infection did not differ with sex for a particular age group; it also did not differ with respect to gastric symptoms, smoking and drinking habits, or urban or rural residence when these potential risk factors were studied. The epidemiological data available on peptic ulcer disease in developing countries compared with developed countries led to the speculation that infection with C. pylori is not a sufficient condition to develop this disease.     

Ascaridia galli populations in chickens following single infections with different dose levels

In all, 3 groups of 20 Lohman Brown chickens aged 1 day were orally infected with doses of 100, 500, or 2,500 embryonated Ascaridia galli eggs, respectively. After 8 weeks, egg counts (eggs per gram of feces, EPG) were determined for all animals prior to slaughter. The gastrointestinal tracts were examined for the presence of adult and immature stages of A. galli. All groups had roughly similar worm burdens and, hence, significantly different establishment rates of 14.2%, 2.9%, and 0.5%, respectively. A significantly lower mean female worm burden was seen in the high-dose group (P = 0.02), which also showed a significantly lower level of egg excretion (P = 0.01). However, fecundity (EPG per female) did not significantly differ between the groups (P = 0.55). The mean lengths of adult worms as well as the weight of the mean worm burdens were significantly smaller in the high-dose group. This study demonstrated that single infections with varying doses of A. galli eggs influenced the establishment rate, sex ratio, egg excretion, and worm size and weight but not the worm fecundity. Received: 8 December 1996 / Accepted: 29 January 1997     

Neurotransmitter levels in two populations of larval Fundulus heteroclitus after methylmercury exposure

The effects of methylmercury (MeHg) exposure on neurotransmitter (NT) levels in larval mummichogs (Fundulus heteroclitus) obtained from a mercury-polluted site (Piles Creek (PC), NJ) and a reference site (Tuckerton (TK), NJ) were examined. Population differences between PC and TK larvae in neurochemical composition and in neurochemical changes in response to MeHg intoxication were found. Heads of untreated PC larvae (7 days posthatch (dph)) contained considerably higher levels of dopamine (DA) and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) than TK. However, they had comparable levels of serotonin (5-hydroxytryptamine (5-HT)) and 5-hyroxy-3-indoleacetic acid (5-HIAA)/5-HT ratios. Changes in NTs with age were noticed, especially in PC larvae. Exposure of larvae to 10 microg/l MeHg induced neurochemical alterations. A significant increase in DA and 5-HT, as well as depressed dopaminergic and serotonergic activity (i.e. decreased DOPAC/DA, HVA/DA and 5-HIAA/5-HT ratios) were seen in TK larvae. Exposure of PC larvae to 10 microg/l MeHg reduced 5-HT at 14 dph, increased serotonergic activity at 7 dph, and altered dopaminergic activity (i.e. increased DOPAC/DA ratios, but decreased HVA/DA ratios). Changes in DA levels were inconsistent over time. The DA level, which was considerably higher than the control at 7 dph, was significantly lower than the control at 14 dph. For the two populations, the level of 5-HT and serotonergic activity, as well as DOPAC and HVA levels, were correlated with previously noted spontaneous activity. The changes in NT levels after exposure to MeHg are an indication of neurological dysfunction in larvae.     

A comparison of physical activity levels in two contrasting elderly populations in Thailand

There is little information available on physical activity patterns in the elderly in developing countries. This is particularly important at a time when developing countries are in transition and show signs of moving toward Western style patterns of physical activity and social structure. This study is unique in that it compares the physical activity levels in two contrasting communities: a residential home and a rural community of elderly subjects in Thailand. Ninety elderly people living in a residential home and 78 elderly people living with their families in a rural community were recruited. The men in the rural community were slightly lighter and leaner than the men in the residential community, but the differences were not significant. However, the women were significantly (P < 0.001) heavier and fatter in the residential home than in the rural community. This is consistent with the higher levels of physical activity in the rural community. There was considerable variation in physical activity in this population. The physical activity level (PAL) values ranged from 1.21 to 1.73 in the residential home and from 1.21 to 3.08 in the rural community. This is apparently the first study of physical activity patterns in elderly subjects in a developing country. It highlights the variation in activity within the rural community and between both communities. The opportunities for the elderly living in the residential home to have active lifestyles are limited. It is likely that this will result in increased morbidity in the final years of life. Am. J. Hum. Biol. 13:310–315, 2001. © 2001 Wiley‐Liss, Inc.     

Marked differences in CCR5 expression and activation levels in two South African populations

The chemokine receptor CCR5 is pivotal in determining an individual's susceptibility to HIV-1 infection and rate of disease progression. To establish whether population-based differences exist in cell surface expression of CCR5 we evaluated the extent of CCR5 expression across all peripheral blood cell types in individuals from two populations, South African Africans (SAA) and South African Caucasians (SAC). Significant differences in CCR5 expression, both in number of CCR5 molecules per cell (density) and the percentage of CCR5-expressing cells, were observed between the two study groups, within all cell subsets. Most notably, the percentage of all CCR5(+) cell subsets was significantly lower in SAC compared with SAA individuals (P < 0·01) among natural killer (NK) -cell subsets (CD56(+) , CD16(+) CD56(+) and CD56(dim) ) whereas CCR5 density was significantly higher in SAC compared with SAA individuals in CCR5(+) CD8(+) T-cell subsets and CCR5(+) NK-cell subsets (CD56(+) , CD16(+) CD56(+) and CD56(dim) ) (all P < 0·05). These relationships were maintained after exclusion of CCR5Δ32 heterozygous individuals (n = 7) from the SAC dataset. The SAA individuals exhibited significantly higher cell activation levels, as measured by HLA-DR expression, than SAC individuals in CD4(+) T-cell subsets (P = 0·002) and CD56(+) NK-cell subsets (P < 0·001). This study serves to demonstrate that ethnically divergent populations show marked differences in both cell activation and CCR5 expression, which are likely to impact on both susceptibility to HIV-1 infection and the rate of HIV-1 disease progression.     

Specific antibody levels in the aqueous humor and serum of two distinct populations of patients with ocular toxoplasmosis

The population of Erechim, Southern Brazil, is characterized by a high incidence of ocular toxoplasmosis, which is presumed to be of acquired origin. We wished to compare the local specific humoral immune response of individuals from this region with that of Swiss patients suffering from the same disease. Paired samples of aqueous humor and serum were withdrawn from 27 Brazilian and 50 Swiss patients presenting consecutively with active ocular toxoplasmosis. The total and specific levels of IgG in each of these were determined. The populations did not differ with respect either to age or sex. The serum levels of total IgG in Brazilian (10.8 g/l) and Swiss patients (11.1 g/l) were similar (p = 0.499), but the aqueous humor ones were higher in the former group (95 vs. 20 mg/l; p = 0.0001). The systemic and local levels of specific IgG were likewise higher in Brazilian patients [206 i.u. vs. 72 i.u. (p = 0.001) and 14 i.u. vs. 4 i.u. (p = 0.005), respectively] and the number of individuals without detectable levels of local specific IgG was correspondingly lower (11% vs. 54%; p = 0.0005). The Goldmann-Witmer coefficient (an index of local specific antibody production) did not differ between Brazilian and Swiss patients (2.1 vs. 0.08, respectively; p = 0.107). Our findings are indicative of a more pronounced uveovascular barrier breakdown in Brazilians than in Swiss patients with active ocular toxoplasmosis. That the systemic and local specific immune response is weaker in Swiss than in Brazilian patients has not been hitherto documented. This finding may reflect differences in the immunological handling of the infection.     

Genetic analysis of HAV strains in Tunisia reveals two new antigenic variants

To evaluate the genetic variability of hepatitis A virus (HAV) isolates in Tunisia, serum samples were collected from 99 patients in different Tunisian areas in 2003 containing 92 cases with acute hepatitis, five with severe acute hepatitis and two with fulminant hepatitis. The entire VP1 gene was amplified and sequenced. Sequences were then aligned and a phylogenetic analysis was performed. Additionally, the amino acid (aa) sequence of the VP1 was determined. The analysis of Tunisian HAV isolates revealed that all the isolates were sub-genotype IA with 96.4%–99.8% of identity and showed the emergence of two novel antigenic variants. The Tun31-03 antigenic variant, with a 38 aa deletion containing Met156, Val171, Leu174 and Ala176 and located between 150 and 187 aa of the VP1 protein where neutralization escape mutations, was found. The second antigenic variant, Tun36-03, was isolated from a patient with fulminant hepatitis and presented a substitution of Thr by Pro at position 10 of the VP1 protein. This amino acid is located in a peptide presenting an antigenically reactive epitope of the VP1 protein. This substitution has never been described previously.     

Human eye-head coordination in two dimensions under different sensorimotor conditions

 The coordination between eye and head movements during a rapid orienting gaze shift has been investigated mainly when subjects made horizontal movements towards visual targets with the eyes starting at the centre of the orbit. Under these conditions, it is difficult to identify the signals driving the two motor systems, because their initial motor errors are identical and equal to the coordinates of the sensory stimulus (i.e. retinal error). In this paper, we investigate head-free gaze saccades of human subjects towards visual as well as auditory stimuli presented in the two-dimensional frontal plane, under both aligned and unaligned initial fixation conditions. Although the basic patterns for eye and head movements were qualitatively comparable for both stimulus modalities, systematic differences were also obtained under aligned conditions, suggesting a task-dependent movement strategy. Auditory-evoked gaze shifts were endowed with smaller eye-head latency differences, consistently larger head movements and smaller concomitant ocular saccades than visually triggered movements. By testing gaze control for eccentric initial eye positions, we found that the head displacement vector was best related to the initial head motor-error (target-re-head), rather than to the initial gaze error (target-re-eye), regardless of target modality. These findings suggest an independent control of the eye and head motor systems by commands in different frames of reference. However, we also observed a systematic influence of the oculomotor response on the properties of the evoked head movements, indicating a subtle coupling between the two systems. The results are discussed in view of current eye-head coordination models. Received: 24 April 1996 / Accepted: 25 October 1996     

Nuclear staining identifies two populations of human sperm with different DNA fragmentation extent and relationship with semen parameters

BACKGROUND: Sperm DNA fragmentation is a possible predictive parameter formale fertility status. The occurrence of M540 bodies in semenof subfertile subjects affects flow cytometric investigationsin sperm. We set up a new method to evaluate DNA fragmentationexcluding M540 bodies. METHODS: DNA fragmentation was evaluated by flow cytometry in semen of75 subjects both by terminal deoxynucleotidyl transferase-mediatedfluorescein-dUTP nick end labeling (TUNEL, traditional method)and by double staining with TUNEL and propidium iodide (PI,new method). RESULTS: The use of the new method revealed that TUNEL underestimatessperm DNA fragmentation in flow cytometry and showed two spermpopulations stained with low (PI^dim) and high (PI^br) avidityfor PI. The PI^dim population is entirely composed of DNA fragmentedsperm and its incidence shows highly significant negative correlationswith morphology, motility, sperm count and concentration (respectively,r = –0.51, –0.52, –0.46 and –0.32, n= 75). DNA fragmentation in the PI^br sperm population is independentfrom semen quality. CONCLUSIONS: The correlations between sperm DNA breakage and semen qualitypreviously reported are mainly driven by the occurrence of thePI^dim population. DNA fragmented sperm in this population aremore likely to have poorer morphology, reduced motility andthus a reduced chance to fertilize an oocyte than DNA damagedsperm in PI^br population. Distinguishing between the two typesof sperm DNA fragmentation appears to be important in clinicalinvestigations.     

Hematological studies of the populations of Lower Silesia living in different ecological conditions]

Haematological investigations were carried out in different population groups in Lower Silesia. The total material investigated included 439 men and 229 women. The investigations demonstrated that the haemoglobin level, erythrocyte count haematocrit index were lower in the population of villages lying around copper processing plants. The mean reticulocyte count exceeded significantly that in the control group. The highest parameters of erythrocyte system were found in the group of men from a large city despite their occupational exposure to exhaust gases. The leucocyte count was 6-7000/mul in all groups with the exception of the urban group in which it was 1000-1500/mul lower than the mean values in the remaining groups. Lymphocytosis was observed most frequently in this group. The highest mean percent of granulocytes and the lowest incidence of lymphocytosis were observed in the control group from a rural population in a non-industrialized area while rural groups around industrial centres showed intermediate values. In the female group from a locality exposed particularly to industrial pollution low platelet count was frequent.     

Methodology of harmonizing hygienic standards for water substances, and its application to improving sanitary water legislation

The article deals with methodology of harmonizing hygienic standards in order to correct and improve Russian sanitary water legislation. This methodology allows drawing on the world experience in the field of water hygiene, which is profitable in terms of cost-effectiveness and can contribute greatly to the national legislation.     

Decompensation of pollen-induced asthma in two towns with different pollution levels in La Mancha, Spain

BACKGROUND: Allergic diseases have increased in industrialized countries and this increase is associated not only with genetic factors but also with lifestyle and environmental factors such as air pollution. Our hypothesis was that asthma in pollen-allergic patients from two towns with very different pollution levels in La Mancha (Spain) could be affected to a very different degree. OBJECTIVE: Our objectives were to assess the risk factors associated with decompensation of pollen-induced asthma in the two towns and to perform a comparison between the patients from Puertollano (high pollution level) and Ciudad Real (low pollution level) with respect to daily symptoms, medication used and peak-flow measurements. METHODS: We designed a cohort study with 137 patients (66 from Puertollano and 71 from Ciudad Real), conducted over 3 years (1999-2001) and including two pollen seasons. The two populations presented similar demographic and clinical characteristics. The variables studied included: area of residence, sex, age, smoking status, asthma symptoms and positive prick tests. Clinical decompensation was monitored by symptoms recorded on diary cards, twice daily peak-flow measurements and the use of protocolized medication. RESULTS: There was a clinically relevant relationship between the place of residence and clinical decompensation. The risk of clinical decompensation in patients from Puertollano was up to three times higher than that of patients in Ciudad Real (P=0.034). Furthermore, patients from Puertollano and patients with moderate asthma presented more rapid decompensation compared with patients from Ciudad Real (P=0.020) and patients with mild asthma (P=0.049). CONCLUSION: In conclusion, pollen-allergic asthmatics in Puertollano present a poorer clinical course and become decompensated earlier than those from Ciudad Real and it could be due to air pollution.     

广州市集中洗消餐具卫生现状及分析

目的了解广州市集中洗消餐具的卫生状况,分析集中洗消餐具的可推广性。方法对被调查企业清洗消毒的餐具进行抽检,同时现场问卷式调查其工艺及卫生管理措施等。结果抽检219宗消毒后的餐具,总体合格率为90.41%,合格率最低的为筷子仅有65.38%。消毒餐具包装前后合格率差异无统计学意义（P=0.413）。集中洗消餐具的合格率明显高于中小型餐饮自行洗消餐具的合格率（P=0.000）,但又低于大型餐饮自行洗消的餐具（P=0.009）。结论集中洗消餐具在不具备消毒条件的中小型餐饮业中具有非常积极的意义,但政府部门需要加强对该行业的监督管理。