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OBJECTIVES: To investigate the molecular epidemiology and genetic structure of the virus strain(s) causing an outbreak of HIV-1 infection in the Kaliningrad province of the Russian Federation and to investigate the relationship of this outbreak to some other emerging HIV-1 epidemics in the countries of the former Soviet Union. DESIGN: A molecular epidemiological investigation was conducted in the city of Kaliningrad amongst individuals recently diagnosed as HIV-1-positive. Samples were also collected from neighbouring Lithuania and from the Ukraine. METHODS: Incident and population data was collected from official health statistics in Kaliningrad. A standardized questionnaire was administered to newly diagnosed individuals to assess risk factors for HIV-1 infection. For genotyping, two regions of the virus (env C2-V3 and gag NCp7) were directly sequenced. RESULTS: The number of newly diagnosed individuals testing seropositive for HIV-1 infection in Kaliningrad rose from less than one per month to more than 100 per month during the period of July-October 1996. A total of 1335 new infections were identified between 1 July 1996 and 30 June 1997. The main reported risk factor for HIV-1 infection (80%) was injecting drug use, in particular with a locally produced opiate. Sequence analysis of patient viruses in Kaliningrad (n = 50) showed that the epidemic was caused by a highly homogenous HIV-1 strain, recombinant between the genetic subtypes A and B. Comparison with subtype A strains prevalent amongst injecting drug users (IDU) in the Ukraine showed that one of these strains was the direct subtype A parent of the epidemic A/B recombinant strain in Kaliningrad. CONCLUSIONS: The HIV-1 epidemic in Kaliningrad probably started from a single source, with rapid spread of the virus through the IDU population. The origin of the epidemic strain is a recombination event occurring between the subtype A strain virus prevalent among IDU in some southern CIS countries, and a subtype B strain of unknown origin.  相似文献   

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1. The ability of airway epithelial cells to produce insulin-like growth factor I may be important in the pathogenesis of subepithelial fibrosis observed in the airways of patients with asthma. We determined whether human airway epithelial cells are capable of producing polypeptide mediators that could induce fibroblast proliferative activity, in particular insulin-like growth factor I. 2. We examined 12 primary cultures of human airway epithelial cells grown to confluence on collagen gel-coated dishes. Using a colorimetric assay based on the uptake and subsequent release of Methylene Blue, increased proliferation of human fetal lung fibroblasts was detected in conditioned media from airway epithelial cells. The median stimulation of fibroblast proliferation was 49.9% (range 25.6-113.3%) above control values (observed at 1:2 dilution of media). 3. A neutralizing antiserum to insulin-like growth factor I partly inhibited fibroblast proliferation induced by epithelial cell conditioned media by 52.2% (49.9-109%; n = 5). 4. Radioimmunoassay for insulin-like growth factor I in conditioned media demonstrated a median concentration of 54.1 ng/ml (32.4-96.8 ng/ml). 5. Insulin-like growth factor I mRNA was detected in epithelial cell monolayers by Northern blot analysis using an insulin-like growth factor I cDNA probe. 6. The insulin-like growth factor I gene is expressed in cultured human airway epithelial cells, which also secrete insulin-like growth factor I protein. Insulin-like growth factor I also accounts for the major mitogenic activity for fibroblasts of cultured human epithelial cell conditioned media. Insulin-like growth factor I may function in a paracrine manner to modulate fibroblast behaviour and may be involved in airway processes, such as those occurring in asthma.  相似文献   

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Manipur, a north-eastern state of India bordering Myanmar, has experienced very rapid transmission of the human immunodeficiency virus (HIV) among its vast drug-injecting population. Seroprevalence among intravenous drug users increased from 0 per cent in September 1989 to 50 per cent within six months. With a minimum injecting population of 15,000 and seropositivity of over 50 per cent, the infection quickly spread to the population at large. One per cent of antenatal mothers tested seropositive by 1991. Forming part of the area of South-East Asia known as the Golden Triangle, and producing opium and its derivatives, Myanmar shares a long international border with four States of the region, and populations with a common language and culture move freely across borders. Two other north-eastern states of India bordering Myanmar have faced a similar epidemic within a short period of time. As a result of serosurveillance for HIV since 1986, the epidemic could be detected at an early stage. The present paper provides an account of the results of ongoing comprehensive studies conducted in the north-eastern states of India on drug-related HIV infection, already a serious problem, but possibly still restricted to that region of the country. The prevalence of intravenous drug users, their HIV serological status, the demographic profile, risk behaviour, the spread of the infection to other groups and the problems of harm minimization are also covered.  相似文献   

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OBJECTIVES: This study assessed recent trends in HIV seroprevalence among injecting drug users in New York City. METHODS: We analyzed temporal trends in HIV seroprevalence from 1991 through 1996 in 5 studies of injecting drug users recruited from a detoxification program, a methadone maintenance program, research storefronts in the Lower East Side and Harlem areas, and a citywide network of sexually transmitted disease clinics. A total of 11,334 serum samples were tested. RESULTS: From 1991 through 1996, HIV seroprevalence declined substantially among subjects in all 5 studies: from 53% to 36% in the detoxification program, from 45% to 29% in the methadone program, from 44% to 22% at the Lower East Side storefront, from 48% to 21% at the Harlem storefront, and from 30% to 21% in the sexually transmitted disease clinics (all P < .002 by chi 2 tests for trend). CONCLUSIONS: The reductions in HIV seroprevalence seen among injecting drug users in New York City from 1991 through 1996 indicate a new phase in this large HIV epidemic. Potential explanatory factors include the loss of HIV-seropositive individuals through disability and death and lower rates of risk behavior leading to low HIV incidence.  相似文献   

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OBJECTIVE: To explore the risk of a future rise of HIV prevalence in populations of injecting drug users (IDU) with low HIV prevalence but continuing risk behaviour, and to study the potential influence of prevention measures on HIV incidence. METHODS: A stochastic simulation model was used to describe a network of long-term buddy relationships in a population of IDU. HIV transmission took place when borrowing injecting equipment from an infected buddy or stranger. The probability of transmission depended on the duration of infection. Individuals remained in the population on average for 10 years. Two surveys amongst IDU in The Netherlands containing information about risk behaviour were used to estimate model parameters. We investigated the effect of different prevention strategies. RESULTS: Below a threshold sharing frequency the epidemic never takes off; above the threshold there is a large stochastic variation in prevalence. After reduction of risk behaviour, HIV prevalence decreases very slowly. Reducing sharing with strangers is more effective than reducing the overall sharing frequency. Prevention focused on new IDU greatly reduces HIV incidence. Reduction of sharing frequency in HIV-positive IDU has no significant influence on HIV incidence at HIV testing rates of 10 and 50% per year, if infectivity is highest during primary infection. CONCLUSIONS: A stabilization of HIV prevalence does not exclude the possibility of a future rise. Predictions about the future course of an epidemic are inherently uncertain. The effect of prevention programmes on HIV prevalence only becomes visible on a long time-scale. Social networks of IDU play an important role in transmission dynamics and success of prevention.  相似文献   

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OBJECTIVES: To estimate the incidence of HIV and hepatitis C virus and risk factors for seroconversion among a cohort of injecting drug users. DESIGN: Retrospective cohort study. SETTING: Primary healthcare facility in central Sydney. SUBJECTS: Injecting drug users tested for HIV-1 antibody (n=1179) and antibodies to hepatitis C virus (n=1078) from February 1992 to October 1995. MAIN OUTCOME MEASURES: Incidence of HIV-1 and hepatitis C virus among seronegative subjects who injected drugs and underwent repeat testing. Demographic and behavioural risk factors for hepatitis seroconversion. RESULTS: Incidence of HIV-1 among 426 initially seronegative injecting drug users was 0.17/100 person years (two seroconversions) compared with an incidence of hepatitis C virus of 20.9/100 person years (31 seroconversions) among 152 injecting drug users initially negative for hepatitis C virus. Incidence of hepatitis C virus among injecting drug users aged less than 20 years was 75.6/100 person years. Independent risk factors for hepatitis C virus seroconversion were age less than 20 years and a history of imprisonment. CONCLUSIONS: In a setting where prevention measures have contributed to the maintenance of low prevalence and incidence of HIV-1, transmission of hepatitis C virus continues at extremely high levels, particularly among young injecting drug users.  相似文献   

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Phylogenetic characterization of primary isolates from 17 HIV-1-infected individuals within a recent epidemic in the city of Odessa, Ukraine was conducted. The isolates were drawn from two time periods, 1993 and 1996. The 1996 isolates coincided with the first apparent expansion of HIV-1 among injection drug users (IDU). Multi-locus phylogenetic analysis indicated that HIV-1 gag, env, tat, and long terminal repeat (LTR) sequences all conformed to the HIV-1 classification of a subcluster within subtype A. There was no evidence for intersubtype recombinants among these isolates. A number of potential signature sequences, particularly within env, were identified in these two time periods, possibly suggesting a selective pressure on viral evolution among IDU. Results of this study are consistent with a recent introduction and subsequent independent evolution of an HIV-1 subtype A subcluster among IDU in the Southern Ukraine. This study demonstrates a congruence of multi-locus phylogenetic analysis, and suggests that non-B genetic subtypes, such as HIV-1 subtype A, may become relevant to the study of IDU transmission in the future.  相似文献   

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AIMS: To determine levels of injecting drug use and sexual risk behaviours in injecting drug users during and immediately following imprisonment in The Netherlands. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional survey of drug injectors attending methadone clinics, a sexually transmitted disease clinic and a central research site in Amsterdam. The mean age of the 188 participants was 35 years, 78% were male and 34% had HIV antibodies. MEASUREMENTS: Self-reported drug use and sexual behaviours during the last period of imprisonment in Dutch prisons within the previous 3 years and injecting drug use in the week following release from prison. FINDINGS: A period of imprisonment in the preceding 3 years was reported by 188 (41%) of 463 interviewed drug injectors. The mean duration of last imprisonment was 3.6 months. Any use of cannabis, heroin or cocaine during imprisonment was reported by 55%, 37% and 20%, respectively. Five injectors (3%) admitted to having injected in prison, but no sharing of needles and syringes was reported. Vaginal or anal sex was reported by two (1%) of the men and none of the women. Relapse to drug injecting during the week following release from prison was reported by 78/186 (42%) participants, in most cases (34%) at the very first day of release. Drug use behaviours during imprisonment were similar for those who were designated current injectors at the time of imprisonment and those who were not, but injecting in the first week following release from prison was far higher among 'current' injectors (63%) than among those who were not (11%). CONCLUSIONS: Contrary to findings from other countries, low levels of HIV risk behaviours occur among imprisoned drug injectors in The Netherlands. Intra-prison HIV preventive measures should be considered taking into account the nationally, regionally or locally varying conditions within the existing prisons.  相似文献   

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OBJECTIVES: To study differences in pre-AIDS mortality between European cohorts of injecting drug users (IDU) and to evaluate whether pre-AIDS mortality increased with time since HIV seroconversion and decreasing CD4 count. METHODS: The study population consisted of 664 IDU with documented intervals of HIV seroconversion from eight cohort studies. Differences in pre-AIDS mortality were studied between European sites; an evaluation of whether pre-AIDS mortality increased with time since HIV seroconversion and decreasing CD4 count was carried out using Poisson regression. RESULTS: One hundred and seven IDU died, of whom 57 did not have AIDS. Pre-AIDS causes of death were overdose/suicide (49%), natural causes such as bacterial infections/cirrhosis (40%), and unintentional injuries/unknown (11%). Considering pre-AIDS death and AIDS as competing risks, 14.7% were expected to have died without AIDS and 17.3% to have developed AIDS at 7 years from seroconversion. No statistically significant differences in pre-AIDS mortality were found between European regions, men and women, age categories and calendar time periods. Overall pre-AIDS mortality did not increase with time since seroconversion, but did increase with decreasing CD4 count. Evaluating cause-specific mortality, only pre-AIDS mortality from natural causes appeared to be associated with time since seroconversion as well as immunosuppression. For natural causes, the death rate per 100 person-years was 0.13 the first 2 years after seroconversion, 0.73 in years 2-4 [risk relative (RR) to years 0-2, 5.6], 1.83 in years 4-6 (RR, 14.0) and 1.54 for > or = 6 years (RR, 11.7). This rate was 0 for a CD4 cell count > or = 500 x 10(6)/l, 1.06 for 200-500 x 10(6)/l and 4.06 for < 200 x 10(6)/l (RR versus > or = 200 x 10(6)/l, 7.0). In multivariate analysis, both CD4 count and time since seroconversion appeared to be independently associated with death from natural causes; CD4 count appeared to be the strongest predictor (adjusted RR, 5.9). CONCLUSIONS: A high pre-AIDS mortality rate was observed among IDU. No significant differences were observed across European sites. Pre-AIDS mortality from natural causes but not from overdose and suicide was associated with HIV disease progression.  相似文献   

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The present study investigated the adaptation process of immigrants from the former Soviet Union in Israel as a multiple-stressor situation that involves cognitive appraisals and coping efforts. A sample of 301 new immigrants (residing in Israel three years or less), 67% women, 25 to 45 years old, completed inventories measuring cognitive appraisals of three major immigration stressors--employment, language, and housing difficulties--and the strategies used to cope with these demands. Level of distress (as indicated by depression and anxiety) was also assessed. The results show positive associations between cognitive appraisals of the various stressors, as well as between the coping strategies applied to them, indicating mutual influences between stressors in a multiple-stressor situation. In addition, an interaction between the appraisals of threat/loss of the three stressors predicted the respondents' distress level, supporting the potentiation model of coping with multiple stressors. Last, the findings support the notion of a stable coping style by showing especially high correlations between coping efforts with different stressors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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The psychological effects of the Gulf War were studied on a group of Israeli civilians particularly at risk, viz. recent immigrants from the former Soviet Union. A quasi-experimental design was used. A sample of immigrants who had already been screened for psychological distress just before the war were reassessed after the war with the same instrument (PERI demoralization questionnaire). Various parameters related to the war period were also assessed. Psychological symptoms during the war were significantly associated with pre-war level of distress and with actual physical harm from the missiles, but not with exposure to danger (proximity of residence to areas hit by missiles). Correlates of behaviour in the face of life-threatening danger during the war (change of residence and help-seeking behaviour) were also identified. Overall the level of post-war psychological distress was not found to be higher than pre-war levels. This was explained by the immigrants' feelings of shared fate, belonging and sense of cohesion, which characterize the general Israeli population during war time.  相似文献   

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Among Hong Kong Chinese blood donors, 99.71 percent were found to be D+. Of these, 55.02 percent were of the phenotype CCDee. The Du phenotype was found to be present in 0.016 percent. Among the 0.27 percent who were apparently D-, 0.079 percent were of the Del phenotype, while the remaining 0.19 percent were "true D-," as defined by a nonreactive eluate obtained by an adsorption and elution procedure using anti-D. The ccdee phenotype constitutes 56.77 percent of the "apparent D-" and 80.24 percent of the true D-. Data show that anti-D rarely occurs in Hong Kong Chinese, and it is postulated that this could be due to the presence of a very weak form of the D antigen among many of those who appear to be D-.  相似文献   

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OBJECTIVE: To study planning of movement in Parkinson's disease. METHODS: The spatiotemporal pattern of movement related desynchronisation (MRD) preceding a self paced voluntary wrist flexion was compared between two groups of 10 untreated right and left hemiparkinsonian patients receiving no treatment and 10 control subjects. The MRD was computed in the 9 to 11 Hz frequency band from 11 source derivations covering the frontocentral, central, and parietocentral areas, during two successive left and right experimental conditions. RESULTS: In the two patient groups the desynchronisation appeared over the primary sensorimotor area contralateral to the affected side with a shorter latency (750 ms before movement onset for the right hemiparkinsonian group and 875 ms for the left hemiparkinsonian group) than in the control group (1750 ms), only when the movements were performed with the akinetic hand. For the non-affected hand, the same latency as in the control group was noted (1750 ms). CONCLUSION: The delay of appearance of MRD in Parkinson's disease confirmed that the programming of movement is affected, thus partially explaining akinesia.  相似文献   

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The blood of the femoral head is thought to be supplied by vessels originating from the medial and lateral circumflex femoral arteries and via the marrow cavity of the neck. Therefore, it is difficult to induce osteonecrosis of the femoral head when the marrow cavity of the neck is preserved. In the present study, we established a new model of femoral head necrosis by dislocating the hip joint and ligating the medial and lateral circumflex femoral arteries and veins. Measurement of femoral head blood flow revealed that a marked decrease to 14.7% of the control value was achieved by both hip dislocation and ligation of blood vessels. Pathologic examination showed no necrosis with either dislocation or ligation alone, whereas at 2 and 4 weeks 80% of the animals subjected to both procedures showed widespread necrosis. These pathologic findings considered in the light of results of the blood flow measurements suggest that a decrease in femoral head blood flow below 20% of the control value is needed to cause osteonecrosis. In addition, magnetic resonance images (MRI) of the model were evaluated in the combined dislocation and ligation group at 4 weeks (n = 5). Changes on MRI were seen in 3 of 5 dogs. The necrotic changes of the femoral head are thought to be detectable on MRI within 4 weeks after ischemia without enhancement.  相似文献   

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