Summary of findings from the evaluation of a pilot medically supervised safer injecting facility

In many cities, infectious disease and overdose epidemics are occurring among illicit injection drug users (IDUs). To reduce these concerns, Vancouver opened a supervised safer injecting facility in September 2003. Within the facility, people inject pre-obtained illicit drugs under the supervision of medical staff. The program was granted a legal exemption by the Canadian government on the condition that a 3-year scientific evaluation of its impacts be conducted. In this review, we summarize the findings from evaluations in those 3 years, including characteristics of IDUs at the facility, public injection drug use and publicly discarded syringes, HIV risk behaviour, use of addiction treatment services and other community resources, and drug-related crime rates. Vancouver's safer injecting facility has been associated with an array of community and public health benefits without evidence of adverse impacts. These findings should be useful to other cities considering supervised injecting facilities and to governments considering regulating their use.     

Combining lung-protective strategies in experimental acute lung injury: The impact of high-frequency partial liquid ventilation.

OBJECTIVE: To evaluate the independent and combined effects of high-frequency oscillatory ventilation (HFOV) and partial liquid ventilation (PLV) on gas exchange, pulmonary histopathology, inflammation, and oxidative tissue damage in an animal model of acute lung injury. DESIGN: Prospective, randomized animal study. SETTING: Research laboratory of a health sciences university. SUBJECTS: Fifty New Zealand White rabbits. INTERVENTIONS: Juvenile rabbits injured by lipopolysaccharide infusion and saline lung lavage were assigned to conventional ventilation (CMV), PLV, HFOV, or high-frequency partial liquid ventilation (HF-PLV) with a full or half dose (HF-PLV1/2) of perfluorochemical (PFC). Uninjured ventilated animals served as controls. Arterial blood gases were obtained every 30 mins during the 4-hr study. Histopathologic evaluation was performed using a lung injury scoring system. Oxidative lung injury was assessed by measuring malondialdehyde and 4-hydroxynonenal in lung homogenates. MEASUREMENTS AND MAIN RESULTS: HFOV, PLV, or a combination of both methods (HF-PLV) resulted in significantly improved oxygenation, more favorable lung histopathology, reduced neutrophil infiltration, and attenuated oxidative damage compared with CMV. HF-PLV with a full PFC dose did not provide any additional benefit compared with HFOV alone. HF-PLV1/2 was associated with decreased pulmonary leukostasis compared with HF-PLV. CONCLUSIONS: The combination of HFOV and PLV (HF-PLV) does not provide any additional benefit compared with HFOV or PLV alone in a combined model of lung injury when lung recruitment and volume optimization can be achieved. The use of a lower PFC dose (HF-PLV1/2) is associated with decreased pulmonary leukostasis compared with HF-PLV and deserves further study.     

男性与女性糖尿病患者致死性冠心病的额外危险：37个前瞻性队列研究的汇总分析

目的：估计男性和女性糖尿病患者致死性冠心病的相对危险。设计：前瞻性队列研究的汇总分析。数据来源：自1966年至2005年3月间Embase和Medline确认并发表的研究，加上源自亚太队列研究协作组的研究，采用正文词组与MeSH主题词相结合的策略进行检索。综述方法：对入选研究的要求为报告有或无糖尿病的男性与女性致死性冠心病的相对危险比较的估计值。如果对估计值仅做年龄调整（而其它因素来经调整——泽者注），则将该研究排除在外。结果：总共纳入37项2型糖尿病和致死性冠心病的研究，涉及447064例患者。糖尿病患者的致死性冠心病发生率显著高于非糖尿病患者（5．4％比1．6％）。与无糖尿病者相比，糖尿病患者发生致死性冠心病的总的相对危险，女性为3．50，95％可信区间为2．70～4．53，显著高于男性患者（2．06，95％可信区间1．81～2．34）。在除外8项仅根据年龄调整的研究后，两性之间危险的差异大大减小，但仍然具有极显著统计学意义。汇集29项经多因素调整估计值的研究，总的相对危险比（女性比男性）为1．46（1．14～1．88）。结论：糖尿病相关的致死性冠心病相对危险，女性比男性高出50％。这种额外的冠心病危险可以通过女性糖尿病患者具有更多不利的心血管危险因素特点以及倾向于对男性患者更注重治疗的可能偏差来解释。     

Interactions of chronic lead exposure and intermittent stress: consequences for brain catecholamine systems and associated behaviors and HPA axis function.

Elevated lead (Pb) burden and high stress levels are co-occurring risk factors in low socioeconomic status (SES) children. Our previous work demonstrated that maternal Pb exposure can permanently alter hypothalamic-pituitary-adrenal (HPA) axis function and responsivity to stress challenges in offspring. The current study sought to determine the consequences of chronic Pb exposures initiated later in development combined with variable intermittent stress challenges. Male rats were exposed chronically from weaning to 0, 50, or 150 ppm Pb acetate drinking solutions (producing blood Pb levels of <5, 9-15, and 23-27 mug/dl, respectively). Pb itself decreased basal plasma corticosterone, with greater effects at 50 than 150 ppm; 150 ppm reduced both cytosolic and nuclear glucocorticoid receptor binding. Responsivity to stress challenges including novelty, cold, and restraint, was measured as changes in Fixed Interval (FI) schedule-controlled behavior in a subset of rats within each group. FI performance was modified by novelty stress only in Pb-treated rats, whereas cold and restraint stress effects were comparable across groups. Novelty elevated corticosterone equivalently across groups, but cold stress markedly increased corticosterone only in Pb-treated groups. The pattern of Pb-induced changes in serotonin (5-HT) or its metabolite 5-HIAA in frontal cortex, nucleus accumbens, striatum, and hypothalamus resembled that observed for basal corticosterone levels indicating a relationship between these variables. In addition to suggesting the potential for HPA axis-mediated effects of Pb on the central nervous system, these findings also raise questions about whether single chemicals studied in isolation from other relevant risk factors can adequately identify neurotoxic hazards.     

Exposure of brown Norway rats to diesel exhaust particles prior to ovalbumin (OVA) sensitization elicits IgE adjuvant activity but attenuates OVA-induced airway inflammation.

Exposure to diesel exhaust particles (DEP) during the sensitization process has been shown to increase antigen-specific IgE production and aggravate allergic airway inflammation in human and animal models. In this study, we evaluated the effect of short-term DEP exposure on ovalbumin (OVA)-mediated responses using a post-sensitization model. Brown Norway rats were first exposed to filtered air or DEP (20.6 +/- 2.7 mg/m3) for 4 h/day for five consecutive days. One day after the final air or DEP exposure (day 1), rats were sensitized with aerosolized OVA (40.5 +/- 6.3 mg/m3), and then again on days 8 and 15, challenged with OVA on day 29, and sacrificed on days 9 or 30, 24 h after the second OVA exposure or the final OVA challenge, respectively. Control animals received aerosolized saline instead of OVA. DEP were shown to elicit an adjuvant effect on the production of antigen-specific IgE and IgG on day 30. At both time points, no significant airway inflammatory responses and lung injury were found for DEP exposure alone. However, the OVA-induced inflammatory cell infiltration, acellular lactate dehydrogenase activity and albumin content in bronchoalveolar lavage (BAL) fluid, and numbers of T cells and their CD4+ and CD8+ subsets in lung-draining lymph nodes were markedly reduced by DEP on day 30 compared with the air-plus-OVA exposure group. The OVA-induced nitric oxide (NO) in the BAL fluid and production of NO, interleukin (IL)-10, and IL-12 by alveolar macrophages (AM) were also significantly lowered by DEP on day 30 as well as day 9. DEP or OVA alone decreased intracellular glutathione (GSH) in AM and lymphocytes on days 9 and 30. The combined DEP and OVA exposure resulted in further depletion of GSH in both cell types. These results show that short-term DEP exposure prior to sensitization had a delayed effect on enhancement of the sensitization in terms of allergen-specific IgE and IgG production, but caused an attenuation of the allergen-induced airway inflammatory responses.     

Dose delivery characteristics of the AIR pulmonary delivery system over a range of inspiratory flow rates.

The purpose of this study was to evaluate the in vitro and in vivo dose delivery characteristics of the AIR pulmonary delivery system over a range of flow rates. A 5-mg placebo powder of engineered particles with low densities (<0.4 g/cc) and large geometric diameters (>5 microm) was delivered via a simple, capsule based, passive dry powder inhaler. The emitted dose, geometric and aerodynamic particle size distributions (aPSDs) were obtained over a range of flow rates (15-60 LPM). The in vitro results demonstrated improved powder dispersion with increasing flow rate through the inhaler. The in vivo dose delivery characteristics were obtained by gamma scintigraphy. Twelve healthy subjects performed the following three inhalation maneuvers: (i) a targeted peak inspiratory flow rate (PIFR) of 20 +/- 10 LPM, (ii) a deep comfortable inhalation, and (iii) a deep forced inhalation. PIFR and inhaled volume were obtained during the inhalation of the dose using a spirometer. In vivo dose delivery was characterized by high and reproducible emitted doses (mean = 87%; inter and intra-subject CV = 5%) and high lung deposition (mean = 51% of the total dose), with low inter and intra-subject CVs (18% and 13%, respectively) across a range of PIFRs (12-86 LPM). Lung deposition of the total dose was shown not to be dependent on PIFR by analysis of variance across the range of inspiratory flow rates (p = 0.29). This was due to the competing effects of smaller aPSDs, increased extrathoracic deposition and higher emitted doses with increasing PIFR. Fully characterizing the effect of inspiratory flow rate requires analysis of the therapeutic response, as well as in vitro dose delivery and lung deposition.