Evidence for a role for α6(∗) nAChRs in l-dopa-induced dyskinesias using Parkinsonian α6(∗) nAChR gain-of-function mice.

l-Dopa-induced dyskinesias (LIDs) are a serious side effect of dopamine replacement therapy for Parkinson's disease. The mechanisms that underlie LIDs are currently unclear. However, preclinical studies indicate that nicotinic acetylcholine receptors (nAChRs) play a role, suggesting that drugs targeting these receptors may be of therapeutic benefit. To further understand the involvement of α6ß2(∗) nAChRs in LIDs, we used gain-of-function α6(∗) nAChR (α6L9S) mice that exhibit a 20-fold enhanced sensitivity to nAChR agonists. Wildtype (WT) and α6L9S mice were lesioned by unilateral injection of 6-hydroxydopamine (6-OHDA, 3µg/ml) into the medial forebrain bundle. Three to 4wk later, they were administered l-dopa (3mg/kg) plus benserazide (15mg/kg) until stably dyskinetic. l-dopa-induced abnormal involuntary movements (AIMs) were similar in α6L9S and WT mice. WT mice were then given nicotine in the drinking water in gradually increasing doses to a final 300µg/ml, which resulted in a 40% decline AIMs. By contrast, there was no decrease in AIMs in α6L9S mice at a maximally tolerated nicotine dose of 20µg/ml. However, the nAChR antagonist mecamylamine (1mg/kg ip 30min before l-dopa) reduced l-dopa-induced AIMs in both α6L9S and WT mice. Thus, both a nAChR agonist and antagonist decreased AIMs in WT mice, but only the antagonist was effective in α6L9S mice. Since nicotine appears to reduce LIDs via desensitization, hypersensitive α6ß2(∗) nAChRs may desensitize less readily. The present data show that α6ß2(∗) nAChRs are key regulators of LIDs, and may be useful therapeutic targets for their management in Parkinson's disease.

Smoking cessation in the workplace.

BACKGROUND: The workplace is an important setting for reaching potentially large numbers of smokers. AIMS: To review the evidence about smoking cessation in the workplace. METHODS: Literature review including a synthesis of findings from recent systematic reviews and meta-analyses of workplace smoking cessation programmes, a separate review of the qualitative evidence, case studies and an expert panel assessment. RESULTS: We found advantages, identified or confirmed from the mixed methods used in this work to holding smoking cessation programmes in the workplace. These included: (i) easy access to large numbers of worker populations for large workplaces, (ii) the potential improved recruitment to such programmes given this, (iii) the opportunity to access young men, traditionally difficult to achieve, (iv) access to occupational health and other staff who can assist with support and delivery and (v) ability for workers to attend relatively easily. Evidence on the importance of developing peer support at work was mixed. The simple provision or availability of programmes and interventions was unlikely to provide any beneficial behaviour change. Interventions should target workers that actively want to stop smoking, use elements that workers have identified as useful or focus on altering beliefs about smoking and the need to stop. CONCLUSIONS: Smoking cessation programmes at work can provide useful support for workers wishing to stop smoking. They are only likely to be effective if participants have moved beyond the contemplation stage regarding smoking cessation, so that stopping smoking is a personal priority.

The clinical effectiveness of negative pressure wound therapy: a systematic review.

OBJECTIVE: To estimate the efficacy of negative pressure wound therapy (NPWT), on the basis of a systematic review of reported randomised controlled trials (RCTs). METHOD: A systematic literature search for relevant RCTs was carried out. The credibility of the outcome of each study was evaluated using a specially constructed instrument. RESULTS: We identified 17 RCTs, of which five had not been included in previous reviews or health technology assessments. For diabetic foot ulcers (seven RCTs), there was consistent evidence of the benefit of NPWT compared with control treatments. For pressure ulcers (three RCTs), results were conflicting. In trials involving mixed wounds (five RCTs), evidence was encouraging but of inadequate quality. Significant complications were not increased. CONCLUSION: There is now sufficient evidence to show that NPWT is safe, and will accelerate healing, to justify its use in the treatment of diabetes-associated chronic leg wounds. There is also evidence, though of poor quality, to suggest that healing of other wounds may also be accelerated.

Standards, regulations and accreditation for registries involved in the worldwide exchange of hematopoietic stem cell donors and products.

The World Marrow Donor Association (WMDA) is working closely with other international organizations working in cellular therapy such as the Worldwide Network for Blood and Marrow Transplantation (WBMT) to develop and maintain global recommendations and requirements for a standardized practice. WMDA launched its registry accreditation program in September 2003. Since then, 17 of the 71 hematopoietic stem cell donor registries worldwide have been accredited. These accredited registries list over 80% of the hematopoietic stem cell donors and umbilical cord blood units listed in the database of BM Donors Worldwide. The goal of the WMDA Standards and Accreditation process is to protect donors while serving the needs of patients who are urgently seeking histocompatible donors in worldwide searches. These activities address the increasing governmental regulations regarding the quality and safety of stem cells collected internationally for national patients.

Responding to health impacts of climate change in the Australian desert.

Climate change is likely to have a significant effect on the health of those living in the 70% of Australia that is desert. The direct impacts on health, such as increased temperature, are important. But so too are the secondary impacts that will occur as a result of the impact of climate change on an uncertain and highly variable natural environment and on the interlinking social and economic systems. The consequence of these secondary impacts will appear as changes in the incidence of disease and infections, and on the psychosocial determinants of health. Responding to the impacts of climate change on health in desert Australia will involve the active participation of a variety of interest groups ranging from local to state and federal governments and a range of public and private agencies, including those not traditionally defined as within the health sector. The modes of engagement required for this process need to be innovative, and will differ among regions on different trajectories. To this end, a first classification of these trajectories is proposed.

Rapid assessment of severe cognitive impairment in individuals with developmental disabilities.

BACKGROUND: Most standardized intelligence tests require more than 1 hour for administration, which is problematic when evaluating individuals with intellectual disabilities and developmental disabilities (IDDD), because a significant proportion of these individuals can not tolerate lengthy evaluations. Furthermore, most standardized intelligence tests are of limited usefulness for individuals with severe cognitive deficits because of floor effects. METHODS: A number of low-difficulty items were selected from standardized tests. A total of 271 participants with profound, severe, moderate and mild levels of cognitive impairment took part in this study. In the formative phase, 68 participants were evaluated with the selected items, and those items that differentiated between levels of cognitive impairment were retained in the battery. The instrument was then modified and standardized with an additional 203 participants. RESULTS: The instrument, referred to as the Rapid Assessment for Developmental Disabilities (RADD), required 10-25 min for administration. Internal reliability estimates from the RADD total score and from individual subtests satisfied conventional and rigorous statistical criteria (median alpha r = 0.93). The RADD total score was strongly correlated with the level of cognitive impairment (rho = 0.86). The RADD total score and individual subtests differentiated between all levels of cognitive impairment ( Wilks Lambda = 0.135, F(42,525.832) = 12.075, P < 0.001). Receiver operating characteristic curves indicated the instrument was particularly sensitive to the cognitive abilities of the most seriously impaired participants. CONCLUSIONS: The RADD, composed of low-difficulty items from published tests, is rapidly administered, assesses a wide range of cognitive skills and differentiates among all levels of cognitive impairment. The battery has clinical utility with populations exhibiting short attention spans because of its ability to quickly assess a wide range of cognitive abilities. The RADD also has research potential for the documentation of cognitive function in studies of individuals with IDDD.

Longitudinal prescribing patterns for psychoactive medications in community-based individuals with developmental disabilities: utilization of pharmacy records.

BACKGROUND: Little is known about longitudinal prescribing practices for psychoactive medications for individuals with intellectual disabilities and developmental disabilities (IDDD) who are living in community settings. METHODS: Computerized pharmacy records were accessed for 2344 community-based individuals with IDDD for whom a total of 3421 prescriptions were written during a 17-month period of study. Forty-two psychoactive medications were rank ordered in terms of prescription frequency. RESULTS: Fifty-two per cent (52%) of all prescriptions written during the study period were for psychoactive medications. Anticonvulsant, antipsychotic and antidepressant medications were the most commonly filled prescriptions among psychoactive medications. Sixty per cent (62%) of the study population was given prescriptions for more than one psychoactive medication and 36% received three or more psychoactive medications. During the study period there was a statistically significant increase in prescriptions filled for olanzapine, risperidone, valproic acid, and clonazepam whereas prescriptions filled for thioridazine, haloperidol, and benzotropine showed a significant decline (P < 0.05-0.001). Distribution of psychoactive drug class by age showed that the majority of prescriptions were filled for individuals between 20 and 50 years with the exception of prescriptions for psychostimulants which peaked for individuals prior to 20 years. CONCLUSIONS: (1) Analysis of pharmacy billing records provides a method for assessing prescribing patterns of psychoactive medications in community-based individuals with IDDD. (2) Polypharmacy for psychoactive medications is prevalent in this setting. (3) The second-generation antipsychotic medications are prominently represented by an increasing number of filled prescriptions during the study period.

Regional antibody and cellular immune responses to equine influenza virus infection, and particle mediated DNA vaccination.

We have previously demonstrated that hemagglutinin (HA) gene vaccination and influenza virus infection generate protective antibody responses in equids. However, these antibody responses differ substantially in that particle mediated DNA vaccination does not induce an immunoglobulin A (IgA) response. A study was performed to investigate the regional immunoregulatory mechanisms associated with these different immune responses. Ponies were either vaccinated with equine HA DNA vaccines at skin and mucosal sites, infected with influenza virus or left untreated and influenza-specific antibody responses and protection from challenge infection was studied. In a subset of ponies, lymphocytes from peripheral blood (PBLs), nasopharyngeal mucosal tissue, or lymph nodes (LNLs) were collected for measurement of influenza virus-specific lymphoproliferative responses, local antibody production and IL-2, IL-4 and IFN-gamma mRNA production by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). DNA vaccination and influenza virus infection induced humoral immunoglobulin Ga (IgGa) and immunoglobulin Gb (IgGb) production and lymphoproliferative responses that were positively correlated with IFN-gamma mRNA production. However, there were marked differences in immune response in that only influenza infection induced an IgA response, and the regional distribution of lymphoproliferation, IFN-gamma and antibody responses. Responses to DNA vaccination occurred in PBLs and in lymph nodes draining DNA vaccination sites, while influenza virus infection induced responses in PBLs and hilar LNLs. In summary, common features of immune responses to either influenza virus infection or DNA vaccination were virus-specific IgGa, IgGb and IFN-gamma responses, which are associated with protection from infection, even when the regional distribution of these immune responses varied depending on the site of immune encounter.

CO2 capture by means of an enzyme-based reactor.

We report a means for efficient and selective extraction of carbon dioxide (CO(2)) at low to medium concentration from mixed gas streams. CO(2) capture was accomplished by use of a novel enzyme-based, facilitated transport contained liquid membrane (EBCLM) reactor. The parametric studies we report explore both structural and operational parameters of this design. The structural parameters include carbonic anhydrase (CA) concentration, buffer concentration and pH, and liquid membrane thickness. The operational parameters are temperature, humidity of the inlet gas stream, and CO(2) concentration in the feed stream. The data show that this system effectively captures CO(2) over the range 400 ppm to at least 100,000 ppm, at or around ambient temperature and pressure. In a single pass across this homogeneous catalyst design, given a feed of 0.1% CO(2), the selectivity of CO(2) versus N(2) is 1,090 : 1 and CO(2) versus O(2) is 790 :1. CO(2) permeance is 4.71 x 10(-8) molm(-2) Pa(-1) sec(-1). The CLM design results in a system that is very stable even in the presence of dry feed and sweep gases.

Chronic care clinics for diabetes in primary care: a system-wide randomized trial.

OBJECTIVE: To evaluate the impact of primary care group visits (chronic care clinics) on the process and outcome of care for diabetic patients. RESEARCH DESIGN AND METHODS: We evaluated the intervention in primary care practices randomized to intervention and control groups in a large-staff model health maintenance organization (HMO). Patients included diabetic patients > or = 30 years of age in each participating primary care practice, selected at random from an automated diabetes registry. Primary care practices were randomized within clinics to either a chronic care clinic (intervention) group or a usual care (control) group. The intervention group conducted periodic one-half day chronic care clinics for groups of approximately 8 diabetic patients in their respective doctor's practice. Chronic care clinics consisted of standardized assessments; visits with the primary care physician, nurse, and clinical pharmacist; and a group education/peer support meeting. We collected self-report questionnaires from patients and data from administrative systems. The questionnaires were mailed, and telephoned interviews were conducted for nonrespondents, at baseline and at 12 and 24 months; we queried the process of care received, the satisfaction with care, and the health status of each patient. Serum cholesterol and HbA1c levels and health care use and cost data was collected from HMO administrative systems. RESULTS: In an intention-to-treat analysis at 24 months, the intervention group had received significantly more recommended preventive procedures and helpful patient education. Of five primary health status indicators examined, two (SF-36 general health and bed disability days) were significantly better in the intervention group. Compared with control patients, intervention patients had slightly more primary care visits, but significantly fewer specialty and emergency room visits. Among intervention participants, we found consistently positive associations between the number of chronic care clinics attended and a number of outcomes, including patient satisfaction and HbA1c levels. CONCLUSIONS: Periodic primary care sessions organized to meet the complex needs of diabetic patients imrproved the process of diabetes care and were associated with better outcomes.

Adaptation of influenza A viruses to cells expressing low levels of sialic acid leads to loss of neuraminidase activity.

Influenza A viruses possess two virion surface proteins, hemagglutinin (HA) and neuraminidase (NA). The HA binds to sialyloligosaccharide viral receptors, while the NA removes sialic acids from the host cell and viral sialyloligosaccarides. Alterations of the HA occur during adaptation of influenza viruses to new host species, as in the 1957 and 1968 influenza pandemics. To gain a better understanding of the contributions of the HA and possibly the NA to this process, we generated cell lines expressing reduced levels of the influenza virus receptor determinant, sialic acid, by selecting Madin-Darby canine kidney cells resistant to a lectin specific for sialic acid linked to galactose by alpha(2-3) or alpha(2-6) linkages. One of these cell lines had less than 1/10 as much N-acetylneuraminic acid as its parent cell line. When serially passaged in this cell line, human H3N2 viruses lost sialidase activity due to a large internal deletion in the NA gene, without alteration of the HA gene. These findings indicate that NA mutations can contribute to the adaptation of influenza A virus to new host environments and hence may play a role in the transmission of virus across species.

Implantable ventricular assist devices: is it time to introduce them in Canada?

BACKGROUND: Implantable left ventricular assist devices (LVAD) are increasingly used in Europe and the United States. Any decision to use them in Canada requires estimates of their clinical value and costs. MATERIALS AND METHODS: No randomized controlled trials are available. Clinical value and costs, concerning principally the HeartMate and Novacor devices, were estimated based on reports of uncontrolled case series obtained through MEDLINE (1993 to 1999), review articles, three technology assessments and data supplied by the manufacturers. RESULTS AND DISCUSSION: Reasonably trouble-free device function can be expected for three to four years. The principal application is as a bridge to transplantation. Rarely, the heart recovers without transplantation. Use as 'permanent' support of the failing heart is still contentious. Approximately 70% of patients with an implanted LVAD survive until recovery or transplantation. Complications are hemorrhage, principally postoperative, 20% to 44%; thromboembolism, ranging from 5% to 15% for the HeartMate to 12% to 37% for Novacor; and significant infection, 50%. Quality of life is slightly inferior to that of patients with transplanted hearts. The direct cost to the health care system of installation is approximately $138,000. As a bridge to transplantation, the estimated cost effectiveness of elective interventions is $91,000 to $126,000 per life-year saved ($117,000 to $186,000, discounted at 5%), and as a permanent alternative to transplantation, the cost per life-year is $52,000 to $60,000 ($50, 000 to $58,000, discounted at 5%), according to circumstances. As a bridge to 50 transplantations per year, the approximate annual cost would be $7 to $13 million (exclusive of transplantation costs). As 'permanent' support for 7000 patients per year, the approximate cost would be $2,661 million per year. CONCLUSIONS: Limited application in a limited number of centres with collection of all data is justifiable at this stage.

Influenza A viruses lacking sialidase activity can undergo multiple cycles of replication in cell culture, eggs, or mice.

Influenza A viruses possess both hemagglutinin (HA), which is responsible for binding to the terminal sialic acid of sialyloligosaccharides on the cell surface, and neuraminidase (NA), which contains sialidase activity that removes sialic acid from sialyloligosaccharides. Interplay between HA receptor-binding and NA receptor-destroying sialidase activity appears to be important for replication of the virus. Previous studies by others have shown that influenza A viruses lacking sialidase activity can undergo multiple cycles of replication if sialidase activity is provided exogenously. To investigate the sialidase requirement of influenza viruses further, we generated a series of sialidase-deficient mutants. Although their growth was less efficient than that of the parental NA-dependent virus, these viruses underwent multiple cycles of replication in cell culture, eggs, and mice. To understand the molecular basis of this viral growth adaptation in the absence of sialidase activity, we investigated changes in the HA receptor-binding affinity of the sialidase-deficient mutants. The results show that mutations around the HA receptor-binding pocket reduce the virus's affinity for cellular receptors, compensating for the loss of sialidase. Thus, sialidase activity is not absolutely required in the influenza A virus life cycle but appears to be necessary for efficient virus replication.

Offering HIV prophylaxis to people who have been sexually assaulted: 16 months' experience in a sexual assault service.

The sexual assault service, operated by the Children's & Women's Health Centre of British Columbia in partnership with the Vancouver General Hospital Emergency Department, started offering HIV prophylaxis in November 1996 to patients presenting to the emergency department after a sexual assault. In the first 16 months of the program a total of 258 people were seen by the service, of whom 71 accepted the offer of HIV prophylaxis. Only 29 continued with the drug treatment after receiving the initial 5-day starter pack, and only 8 completed the full 4-week treatment regmen and returned for their final follow-up visit. Patients at highest risk for HIV infection (those who had penetration by an assailant known to be HIV positive or at high risk for HIV infection [men who have sex with men, injection drug users]) were more likely to accept prophylaxis and more likely to complete the treatment than those at lower risk. Compliance and follow-up were the main problems with implementing this service. Service providers found it difficult to give the information about HIV prophylaxis to traumatized patients. After this program evaluation, the service changed its policy to offer HIV prophylaxis only to people at high risk of HIV infection. This targeting of services is expected to make the service providers' jobs easier and to make the program more cost-effective while still protecting sexual assault victims against HIV infection.

Pharmacophore fingerprinting. 2. Application to primary library design.

A methodology for pharmacophore fingerprinting (PharmPrint), previously described in the context of QSAR, has been used to address the issues involved in primary library design. A subset of the MDDR (MDDR9104) has been used to define a reference set of bioactive molecules. A statistic has been devised to measure the discriminating power of molecular descriptors using the target class assignments for this set, for which the PharmPrint fingerprint outperformed other descriptors. A principal components analysis (PCA) of the fingerprints for the MDDR9104 produces a low dimensional representation within which molecular properties and other libraries can be visualized and explored. PCA calculations on subsets of classes show that this space is robust to the addition of new classes, suggesting that pharmacophoric space is finite and rapidly converging. We demonstrate the application of the PharmPrint methodology to the analysis and design of virtual combinatorial libraries using common scaffolds and building blocks.

No evidence of infection with porcine endogenous retrovirus in recipients of encapsulated porcine islet xenografts.

Transplantation of pig tissues into humans has the potential for cotransferring pig infections. Knowledge of the epidemiology of pig infections transmissible to humans allows the development of risk limitation strategies at the source herd level, but potentially infectious pig endogenous retrovirus (PERV) is ubiquitous in all domestic pigs and therefore is not avoidable. Using a specific and sensitive RT-PCR and nested PCR for PERV nucleic acids with primers, the screening of pigs from New Zealand herds for the presence and expression of the PERV was conducted. The presence of PERV proviral DNA (pol and env region) and viral RNA was demonstrated in all tested pig tissues including pancreas, liver, spleen, brain, heart, and PBMC. Using the same assays it was established that different tissues (liver, spleen, and heart) of nude and nonobese diabetic (NOD) mice previously transplanted with nonencapsulated pig islets were PERV DNA and RNA negative. Alginate polylysine capsules prepared with encapsulated pig islets were tested for possible leakage of viral particles or viral nucleic acids. RNA was extracted from the supernatant of viable encapsulated pig islet cells grown in culture for 2 months. No evidence of PERV RNA or of cellular nucleic acids could be found. Two adult type I diabetic subjects were transplanted with 1 x 10(6) neonatal pig islets encased in alginate capsules into the peritoneal cavity. One patient was immunosuppressed. Both showed evidence of graft function (up to 34% reduction in insulin dose, corresponding increase in serum pig C-peptide) for up to 2 years. DNA and RNA were extracted from PBMC and blood plasma of both patients at 19 months posttransplant. No evidence of PERV proviral DNA or RNA could be detected. Piglet islets contain PERV DNA and RNA, but this does not traverse the capsules used or produce any evidence of infection in nude and nonobese diabetic (NOD) mice or humans.