Sexual violence among a cohort of injection drug users

The objective of this study was to determine the prevalence of, and factors associated with, sexual violence in childhood, adolescence and adulthood, among injection drug using men and women. The Vancouver Injection Drug User Study is a prospective cohort of injection drug users (IDU) begun in 1996. The analysis included all individuals who completed the baseline questionnaire who responded to a question about sexual assault. Multivariate modeling was used to determine and to what extent a history of sexual violence at different ages is predictive of HIV risk and other health risk behaviors. HIV prevalence was calculated as the total current number of HIV-positive individuals in the cohort. Of the 1437 eligible individuals, 36% reported a lifetime history of sexual violence; 68% of women, and 19% of men (p<0.001). After adjusting for fixed sociodemographics, these individuals were more likely to have ever been in the sex trade, to knowingly share needles/rigs with HIV-positive people, to have attempted suicide, to have ever accidentally overdosed, to binge on alcohol, and to have been diagnosed with a mental disorder/disability. The prevalence of child sexual abuse in this cohort is 21%; 33% for women, and 13% for men. The data show a dose-response relationship between age at first sexual violence and most risk behaviors examined. These relationships are further mediated by gender. The prevalence of HIV among individuals who ever experienced sexual violence was 25%, compared to 19% among those who never experienced sexual violence (p=0.006). Sexual violence, and especially child sexual abuse, is highly prevalent among this cohort, particularly among women. Child sexual abuse has worse consequences for both genders than sexual violence later in life. Nevertheless, women and men are affected differently by sexual violence at different ages, and this has significant implications for health promotion programs, and specifically HIV prevention.     

Requiring help injecting as a risk factor for HIV infection in the Vancouver epidemic: implications for HIV prevention

BACKGROUND: Requiring help injecting was recently associated with syringe sharing, and later HIV-1 and HCV seroconversion among injection drug users (IDU) in Vancouver. This risk factor remains poorly understood. The present study investigates this risk factor among Vancouver IDUs. METHODS: We evaluated factors associated with requiring help injecting among participants enrolled in the Vancouver Injection Drug User Study (VIDUS) using univariate and logistic regression analyses. VIDUS participants who were followed-up during the period December 2000 to December 2001 were eligible for the present analyses. We also evaluated self-reported reasons for requiring help injecting. RESULTS: Overall, 661 active injection drug users were interviewed during the study period. Among this population, 151 (22.8%) had required help injecting during the last six months, whereas 510 (77.2%) indicated that they had not. Variables that were independently associated with requiring help injecting included borrowing a used syringe (adjusted odds ratio [AOR] = 2.18), frequent cocaine injection (AOR = 1.57), and female gender (AOR = 2.29). Among males, the most common reasons for requiring help injecting were: having no viable veins (77.1%), and anxiousness or being drug sick (42.9%). Among females, the most common reasons reported were: having no viable veins (71.6%), jugular injection or 'jugging' (45.7%), and being anxious or drug sick (27.2%). Almost twice as many females (13.6% vs 7.1%) reported not knowing how to inject as their reason for requiring help injecting. CONCLUSION: Although current public health approaches, such as needle exchange, are unable to address the concerns associated with requiring help injecting, available evidence suggests that safer injecting facilities have the potential to substantially mitigate this risk behaviour.     

Ocular MR imaging and spectroscopy: an ex vivo study

Six eyes, freshly enucleated because of choroidal melanoma, were imaged on a 1.4-T superconducting magnetic resonance (MR) imaging system, and relaxation times were calculated for various parts of the eye. Unfixed fresh tissue samples were obtained for nuclear magnetic resonance spectroscopy (NMRS) on a variable-field (0.19-1.4 T) resistive unit. Detailed ocular anatomy was demonstrated. The NMRS relaxation times correlated with the MR imaging intensity patterns. The sensitivity of MR imaging to states of hydration provides an excellent window for appreciation of ocular anatomy.     

Primary retroperitoneal myxoid/round cell liposarcoma is a nonexisting disease: an immunohistochemical and molecular biological analysis

Almost all primary retroperitoneal liposarcomas can be classified as well-/dedifferentiated liposarcoma. Rarely, however, primary retroperitoneal liposarcoma is classified as myxoid/round cell liposarcoma, based on the presence of myxoid areas and vascular crow's feet pattern, which has resulted in a debate on the classification of liposarcoma in the retroperitoneum. Genetically, myxoid/round cell liposarcoma and well-/dedifferentiated liposarcoma are different diseases. Myxoid/round cell liposarcoma is characterized by a translocation causing FUS-CHOP or EWSR1-CHOP fusion, whereas well-/dedifferentiated liposarcoma is characterized by an amplification of the 12q13-15 region, including MDM2 and CDK4 genes. As myxoid/round cell liposarcoma is highly radio- and chemosensitive, differentiation between subtypes is important to optimize treatment. We studied whether primary retroperitoneal liposarcomas diagnosed as myxoid/round cell liposarcoma represent molecularly true myxoid/round cell liposarcoma or are histopathological mimics and represent well-/dedifferentiated liposarcoma. Primary retroperitoneal myxoid/round cell liposarcoma (n=16) were compared to primary extremity myxoid/round cell liposarcoma (n=20). Histopathological and immunohistochemical features were studied. Amplification status of the 12q13-15 region was studied using a multiplex ligation-dependent probe amplification analysis, and FUS-CHOP or EWS-CHOP translocations were studied using RT-PCR. In primary retroperitoneal myxoid/round cell liposarcoma, MDM2 and CDK4 staining was both positive in 12 of 15 cases. In primary extremity myxoid/round cell liposarcoma, MDM2 was negative in 18/20 and CDK4 was negative in all cases. Multiplex ligation-dependent probe amplification showed the amplification of 12q13-15 region in 16/16 primary retroperitoneal myxoid/round cell liposarcomas and in 1/20 primary extremity myxoid/round cell liposarcomas. Translocation was present in all (18/18) primary extremity myxoid/round cell liposarcomas, but absent in all primary retroperitoneal myxoid/round cell liposarcomas. On the basis of immunohistochemical and molecular characteristics, apparent primary retroperitoneal myxoid/round cell liposarcoma can be recognized as well-/dedifferentiated liposarcoma with morphological features mimicking myxoid/round cell liposarcoma. In these cases, treatment should probably be specifically designed as for well-/dedifferentiated liposarcoma. Moreover, finding of myxoid/round cell liposarcoma translocations in a retroperitoneal localization is highly suggestive of metastasis and should prompt search for a primary localization outside the retroperitoneum.     

Femoral capital osteonecrosis: MR finding of diffuse marrow abnormalities without focal lesions

Six painful hips in five patients were examined with magnetic resonance (MR) imaging and were found to have diffuse signal abnormalities in the marrow of the femoral head and neck, which extended into the intertrochanteric area in five cases. The abnormal regions were low in signal intensity on images obtained with a short repetition time (TR) and a short echo time (TE) and were isointense or hyperintense on long TR/TE images--findings that have been attributed by others to bone marrow edema. Edema was also seen in marrow just above the acetabulum in two cases. No focal abnormalities characteristic of osteonecrosis were seen. Osteonecrosis was subsequently shown to be present in all six femoral heads at core biopsy (three cases) or by subsequent development of focal MR abnormalities reported to be highly specific for osteonecrosis (three cases). The affected hips had been radiographically normal or subtly osteopenic and had shown intense radionuclide uptake in the femoral head at scintigraphy, with lesser abnormality in the neck and intertrochanteric region. Follow-up MR examinations of five of the six femoral heads showed the diffuse abnormalities to have been transient. Although diffuse MR abnormalities in the proximal femur are not specific, they may indicate the presence of osteonecrosis of the femoral head.     

Iron, ascorbate and copper status of Sowetan Blacks with calcific chronic pancreatitis

Vitamin C can be used to overcome oxidative stress and ease pain in chronic pancreatitis. But its use is deprecated in conditions of tissue iron overload, because its bioactive form, ascorbate, can accelerate free-radical reactions that are driven by transition metals. We measured iron, ascorbate and copper in Sowetan Blacks (RSA) with chronic pancreatitis, obtaining serum/plasma from 14 consecutive patients and 15 controls. Compared with data from corresponding groups in Manchester, African samples had less ascorbate (p < 0.0001), but more caeruloplasmin (p < 0.0001). African and British controls had comparable iron and iron-binding capacity. Plasma from African patients had less ascorbate than that from African controls (p < 0.005) and in six samples, ferritin exceeded 300 micrograms/l (677 pmol/l). Low- molecular-mass iron or copper, capable of participating in free radical reactions, was not detected. British patients, had similar caeruloplasmin levels to African patients but higher ascorbate levels. There is no evidence of iron overload in our African samples. Outwardly healthy controls from Soweto have elevated levels of caeruloplasmin, possibly to compensate for dietary deficiency of ascorbate. Persistent oxidative stress is a unifying feature of chronic pancreatitis, but its degree is higher in African than British patients. Supplements of vitamin C should be safe in Blacks of southern Africa.      

自体造血干细胞的体外净化

目的:综合分析自体造血干细胞体外净化的方法。资料来源:应用计算机检索Medline 1991-01/2003-12有关自体造血干细胞体外净化方法的文章,检索词“purging,HSCT”,并限定文章语言种类为English。同时计算机检索CNKI数据库1991-01/2003-12有关自体造血干细胞体外净化方法的文章,检索词“体外净化,PUVA”,并限定文章语言种类为中文。资料选择:对相关资料进行整理,选取同一领域、不同方面的文献,以近期发表或权威杂志的文章优先。资料提炼:共检索到42篇有关自体造血干细胞体外净化方法的文献,其中24篇文章符合要求。排除18篇,其中15篇系重复同一研究,3篇为Meta分析。资料综合:自体造血干细胞的体外净化方法很多,如物理方法、生物学方法、药物方法、免疫净化、基因净化等。每种净化方法都有其各自的优势和不足,如淋巴系统疾病可以采用免疫净化;慢性粒细胞白血病患者可考虑反义技术;大多数患者则均可以考虑药物净化的方法。结论:针对不同的疾病,可以选择不同的净化方法,还可以将几种净化方法联合起来,其效果和方法的改进也在不断的研究探索中。     

Reduction in transmission of hepatitis C after the introduction of a heat-treatment step in the production of C1-inhibitor concentrate

BACKGROUND: The transmission of viral infections via protein concentrates made from a large pool of plasma depends on the selection of donors, fractionation process, and virucidal methods. To date, no data are available on the infectivity risk of plasma concentrates of the inhibitor of the first component of complement (C1-INH). STUDY DESIGN AND METHODS: The prevalence of blood-borne viral infections and levels of transaminases were evaluated in patients treated with a large- pool plasma concentrate of the inhibitor of C1-INH before and after the introduction of virucidal methods. The study included 85 patients with hereditary angioedema and 4 with acquired angioedema. The patients were divided into three groups: 1) 48 untreated patients; 2) 22 patients treated with non-virus-inactivated C1-INH concentrates; and 3) 19 patients treated with virus-inactivated concentrates. Serum samples obtained at various times after the infusion of concentrate were assayed for alanine amino-transferase and tested for hepatitis B surface antigen and antibodies to hepatitis C virus (anti-HCV) and human immunodeficiency virus (anti-HIV); anti-HCV-negative subjects exposed to the concentrate were also tested for HCV RNA. RESULTS: Prevalences of HCV infection and elevated alanine aminotransferase are significantly lower in patients treated with virus-inactivated concentrates than in those exposed to non-virus-inactivated concentrates. No patients were anti-HIV positive. CONCLUSION: This study suggests that C1-INH concentrates transmitted HCV, but that the virucidal methods adopted are effective in reducing the infectivity.