Shooting Gallery Attendance among IDUs in Tijuana and Ciudad Juarez, Mexico: Correlates, Prevention Opportunities, and the Role of the Environment

We identified factors associated with shooting gallery attendance among injection drug users (IDUs) in two Mexico-US border cities. IDUs in Tijuana (n=222) and Ciudad Juarez (n=205), Mexico, who were >or=18 years and injected illicit drugs in the last month were recruited using respondent-driven sampling (RDS). An interviewer-administered survey collected sociodemographic and behavioral data. Logistic regression was used to examine correlates of shooting gallery attendance in each of the two cities. Homelessness and being arrested for syringe possession--both structural level factors--were associated with shooting gallery use in both cities. In Ciudad Juarez, younger age and having overdosed were also associated with shooting gallery use. Our study highlights the need for structural interventions that mitigate homelessness among IDUs and facilitate changes in law enforcement practices associated with shooting gallery use. Harm reduction interventions based within shooting galleries should also be considered to prevent transmission of blood-borne pathogens among IDUs.     

Protein kinase C α and ε phosphorylation of troponin and myosin binding protein C reduce Ca2+ sensitivity in human myocardium

Previous studies indicated that the increase in protein kinase C (PKC)-mediated myofilament protein phosphorylation observed in failing myocardium might be detrimental for contractile function. This study was designed to reveal and compare the effects of PKCα- and PKCε-mediated phosphorylation on myofilament function in human myocardium. Isometric force was measured at different [Ca²⁺] in single permeabilized cardiomyocytes from failing human left ventricular tissue. Activated PKCα and PKCε equally reduced Ca²⁺ sensitivity in failing cardiomyocytes (ΔpCa₅₀ = 0.08 ± 0.01). Both PKC isoforms increased phosphorylation of troponin I- (cTnI) and myosin binding protein C (cMyBP-C) in failing cardiomyocytes. Subsequent incubation of failing cardiomyocytes with the catalytic subunit of protein kinase A (PKA) resulted in a further reduction in Ca²⁺ sensitivity, indicating that the effects of both PKC isoforms were not caused by cross-phosphorylation of PKA sites. Both isozymes showed no effects on maximal force and only PKCα resulted in a modest significant reduction in passive force. Effects of PKCα were only minor in donor cardiomyocytes, presumably because of already saturated cTnI and cMyBP-C phosphorylation levels. Donor tissue could therefore be used as a tool to reveal the functional effects of troponin T (cTnT) phosphorylation by PKCα. Massive dephosphorylation of cTnT with alkaline phosphatase increased Ca²⁺ sensitivity. Subsequently, PKCα treatment of donor cardiomyocytes reduced Ca²⁺ sensitivity (ΔpCa₅₀ = 0.08 ± 0.02) and solely increased phosphorylation of cTnT, but did not affect maximal and passive force. PKCα- and PKCε-mediated phosphorylation of cMyBP-C and cTnI as well as cTnT decrease myofilament Ca²⁺ sensitivity and may thereby reduce contractility and enhance relaxation of human myocardium.     

Individual States in the Cycle of Muscle Contraction

By using appropriate analogs of ATP, isometrically-held glycerol-extracted psoas fibers from rabbits are forced successively into states corresponding to molecular species in the contractile cycle. In each state measurements are made of P[unk], a fluorescence polarization parameter thought to relate to attitude of S-1 moieties of the myosin molecules. Also, the value of P[unk] is measured during active tension development. It is suggested that this value is a time-average of the P[unk] as S-1 moieties move through the various states of the cycle. Proposals are made concerning the sequence of states in the cycle.     

Condom use among female sex workers and their non-commercial partners: effects of a sexual risk intervention in two Mexican cities

The purpose of this study was to examine whether a brief behavioural intervention promoting condom use among female sex workers (FSWs) and their clients had the added benefit of increasing condom use among FSWs and their steady, non-commercial partners (e.g. husbands, boyfriends). Participants were 362 FSWs, aged ≥18 years, living in Tijuana or Ciudad Juarez, Mexico, who received a behavioural intervention to promote condom use with clients. Repeated-measures negative binomial regression was used to assess FSWs' condom use with steady partners versus clients across time. Results showed that FSWs engaged in unprotected sex with steady partners more than with their clients, and that the intervention changed FSWs' condom use with clients but not their steady partners. HIV-prevention interventions for FSWs should promote consistent condom use across partner type. Targeting couples rather than individuals may also be necessary.     

Prevalence of hepatitis C virus and HIV infection among injection drug users in two Mexican cities bordering the U.S

OBJECTIVE: To estimate the prevalence of the hepatitis C virus (HCV) and HIV infection and associated risk behaviors among injection drug users (IDUs) in two northern Mexican cities. MATERIAL AND METHODS: Between February and April 2005, IDUs were recruited in Tijuana (N=222) and Ciudad Juarez (N=206) using respondent-driven sampling (RDS), a chain referral sampling approach. Interviewer-administered questionnaires assessed drug-using behaviors during the prior six months. Venous blood was collected for immunoassays to detect HIV and HCV antibodies. For HIV, Western blot or immunofluorescence assay was used for confirmatory testing. Final HCV antibody prevalence was estimated using RDS adjustments. RESULTS: Overall, HCV and HIV prevalence was 96.0% and 2.8%, respectively, and was similar in both cities. Most IDUs (87.5%) reported passing on their used injection equipment to others, and 85.9% had received used equipment from others. CONCLUSIONS: HIV prevalence was relatively high given the prevalence of HIV in the general population, and HCV prevalence was extremely high among IDUs in Tijuana and Ciudad Juarez. Frequent sharing practices indicate a high potential for continued transmission for both infections. HCV counseling and testing for IDUs in Mexico and interventions to reduce sharing of injection equipment are needed.     

Riesgo de recurrencia tras retirada de la anticoagulación en pacientes con enfermedad tromboembólica venosa no provocada: validación externa del nomograma de Viena y del modelo predictivo DASH

IntroductionScales for predicting venous thromboembolism (VTE) recurrence are useful for deciding the duration of the anticoagulant treatment. Although there are several scales, the most appropriate for our setting has not been identified. For this reason, we aimed to validate the DASH prediction score and the Vienna nomogram at 12 months.MethodsThis was a retrospective study of unselected consecutive VTE patients seen between 2006 and 2014. We compared the ability of the DASH score and the Vienna nomogram to predict recurrences of VTE. The validation was performed by stratifying patients as low-risk or high-risk, according to each scale (discrimination) and comparing the observed recurrence with the expected rate (calibration).ResultsOf 353 patients evaluated, 195 were analyzed, with an average age of 53.5 ± 19 years. There were 21 recurrences in 1 year (10.8%, 95% CI: 6.8%-16%). According to the DASH score, 42% were classified as low risk, and the rate of VTE recurrence in this group was 4.9% (95% CI: 1.3%-12%) vs. the high-risk group that was 15% (95% CI: 9%-23%) (p <.05). According to the Vienna nomogram, 30% were classified as low risk, and the rate of VTE recurrence in the low risk group vs. the high risk group was 4.2% (95% CI:0.5%-14%) vs. 16.2% (95% CI: 9.9%-24.4%) (p <.05).ConclusionsOur study validates the DASH score and the Vienna nomogram in our population. The DASH prediction score may be the most advisable, both because of its simplicity and its ability to identify more low-risk patients than the Vienna nomogram (42% vs. 30%).     

Adipokines,cytokines and body fat stores in hepatitis C virus liver steatosis

AIM: To identify patients with or without liver steatosis and its severity in treatment-na?ve patients affected by hepatitis C virus(HCV) infection.METHODS: We included 56 HCV infected patients, and assessed the amount of liver fat by histomorphometry, and its relationships with fat and lean mass at different parts of the body(by densitometry), hormones [insulin, homeostatic model assessment(HOMA)], adipokines(resistin, adiponectin, leptin), and cytokines(tumor necrosis factor α, interleukin-6).RESULTS: Although the intensity of liver steatosis is related to trunk fat mass and HOMA, 33% of patients showed no liver steatosis, and this finding was not related to body mass index or genotype. Besides trunkfat mass, no other factor was related to the presence or not of liver steatosis, or to the intensity of it, by multivariate analysis. Lean mass was not related to liver steatosis. Adiponectin levels were lower among patients. No differences were observed in leptin and resistin.CONCLUSION: Steatosis in HCV infection is common(67.2%), and closely related to trunk fat, and insulin resistance, but not with leg fat mass or adipokines.     

Intraoperative small bowel enteroscopy in familial adenomatous and familial juvenile polyposis

Background: In familial adenomatous polyposis and juvenile polyposis, polyps can occur throughout the gastrointestinal tract.Methods: We report seven patients with familial adenomatous polyposis and two patients with juvenile polyposis who underwent small bowel enteroscopy at the time of exploratory celiotomy either for colectomy or other pathology.Results: Polyps in the jejunum and/or ileum were noted in five of nine (56%) patients at enteroscopy. In three of nine (33%) patients these polyps were adenomatous. Two of these patients had polyps in the jejunum and in the ileum, whereas one patient had jejunal adenomas alone. These polyps were from 3 mm to 30 mm in size. The remaining two patients with polyps had lymphoid hyperplasia in the ileum. All three patients who had adenomas at intraoperative small bowel enteroscopy had duodenal adenomas at esophagogastroduodenoscopy. At the age of 14 years, one patient had an intramucosal carcinoma in a small bowel juvenile polyp.Conclusion: Baseline small bowel enteroscopy should be considered at the time of surgical exploration in patients with asymptomatic familial adenomatous polyposis and juvenile polyposis. In patients with duodenal polyps, enteroscopy should be performed at the time of surgery. Biopsy and/or excision of larger polyps should be performed because these polyps may harbor a carcinoma. (Gastrointest Endosc 1995;42:560-4.)     

Tissue inhibitor of metalloproteinase-3 is up-regulated by transforming growth factor-beta1 in vitro and expressed in fibroblastic foci in vivo in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is characterized by fibroblast expansion and extracellular matrix accumulation. However, the mechanisms involved in matrix remodeling have not been elucidated. In this study, the authors aimed to evaluate the expression of the tissue inhibitors of matrix metalloproteinases (TIMPs) in human fibroblasts and whole tissues from IPF and normal lungs. They also determined the role of mitogen-activated protein kinase (MAPK) in TIMP3 expression. TIMP1, TIMP2, and TIMP3 were highly expressed in lung fibroblasts. Transforming growth factor (TGF)-beta1, a profibrotic mediator, induced strong up-regulation of TIMP3 at the mRNA and protein levels. The authors examined whether the MAPK pathway was involved in TGF-beta1-induced TIMP3 expression. TGF-beta1 induced the phosphorylation of p38 and extracellular signal-regulated kinase (ERK)1/2. Biochemical blockade of p38 by SB203580, but not of the ERK MAPK pathway, inhibited the effect of this factor. The effect was also blocked by the tyrosine kinase inhibitor genistein and by antagonizing TGF-beta1 receptor type I (activin-linked kinase [ALK5]). In IPF tissues TIMP3 gene expression was significantly increased and the protein was localized to fibroblastic foci and extracellular matrix. Our findings suggest that TGF-beta1-induced TIMP3 may be an important mediator in lung fibrogenesis.