593 research outputs found

    Validation Aspects of Water Treatment Systems for Pharmaceutical Products

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    The goal of conducting validation is to demonstrate that a process, when operated within established limits, produces a product of consistent and specified quality with a high degree of assurance. Validation of water treatment systems is necessary to obtain water with all desired quality attributes. This also provides a framework to establish a total control over the process which monitors safety, efficacy and ultimately, the process outcomes. The present overview is an attempt to discuss various aspects of validation including different approaches, components of water treatment systems, equipment qualifications, phases of performance testing, documentation and post-validation monitoring.Keywords: Validation; Water treatment systems; Quality attributes; Pharmaceutical product

    Size of HIV-1 reservoir is associated with telomere shortening and immunosenescence in early-treated European children with perinatally acquired HIV-1

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    INTRODUCTION: Persistence of HIV-1, causing chronic immune activation, is a key determinant of premature senescence. Early antiretroviral therapy (ART) has been associated with a reduced HIV-1 reservoir in children with perinatally acquired HIV-1 (PHIV), but its impact on the senescence process is an open question. We investigated the association between HIV-1 reservoir and biological and immune ageing profile in PHIV enrolled in the multicentre cross-sectional study CARMA (Child and Adolescent Reservoir Measurements on early suppressive ART) conducted within the EPIICAL (Early treated Perinatally HIV Infected individuals: Improving Children's Actual Life) consortium. METHODS: Between September 2017 and June 2018, CARMA enrolled 40 PHIV who started ART before 2 years of age and had undetectable viremia for at least 5 years before sampling date. Samples from 37 children with a median age of 13.8 years were available for this study. HIV-1 DNA copies on CD4 cells, relative telomere length (marker of cellular senescence) and levels of T-cell receptor rearrangement excision circle (TREC, marker of thymic output) on CD4 and CD8 cells were quantified by qPCR. Immunological profile was assessed by flow cytometry. Associations between molecular and phenotypic markers, HIV-1 reservoir and age at ART initiation were explored using a multivariable Poisson regression. RESULTS: Higher HIV-1 reservoir was associated (p<0.001) with telomere shortening (incidence rate ratio [IRR] = 0.15 [0.13-0.17]), immunosenescence (CD28- CD57+ , IRR = 1.23 [1.21-1.26]) and immunoactivation (CD38+ HLADR+ , IRR = 7.29 [6.58-8.09]) of CD4 cells. Late ART initiation (after 6 months of age) correlated with higher HIV-1 reservoir levels (552 [303-1001] vs. 89 [56-365] copies/106 CD4 cells, p = 0.003) and percentage of CD4 senescent cells (2.89 [1.95-6.31] vs. 1.02 [0.45-2.69, p = 0.047). TREC levels in CD8 cells were inversely associated with HIV-1 reservoir (IRR = 0.77 [0.76-0.79]) and were significantly lower in late treated PHIV (1128 [486-1671] vs. 2278 [1425-3314], p = 0.042). CONCLUSIONS: Later ART initiation is associated with higher HIV-1 reservoir size, which correlates with increased telomere shortening and senescence of CD4 cells. Timing of ART initiation in infancy has long-term consequences on the immune and biological ageing profile of children with perinatally acquired HIV-1

    Suppression of natural killer (NK) cell activity of spleen cells by thymocytes

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    The in vitro influence of thymus cells on natural killer cell activity of spleen cells against prelabeled target cells (YAC-I and RL[male symbol]I) has been studied in syngeneic as well as in allogeneic murine models. In mixing experiments to demonstrate suppression, total thymocytes have been found to have no effect on NK activity of syngeneic or allogeneic spleen cells. Among several thymocyte fractions separated by velocity sedimentation, a relatively faster sedimenting fraction showed remarkable suppression of NK activity by spleen cells against two target cells. The suppressive effect of this particular fraction on NK activity was demonstrated to be proportional to the cell dose. The suppressive function was resistant to irradiation at 1000 or 2000 rad administered in vitro and was not restricted by the major histocompatibility complex. Moreover, the thymocyte fraction which induced suppression was not sensitive to NK-mediated cytolysis by syngeneic spleen cells. The suppression of NK cytolysis in vitro by certain subpopulations of thymocytes as observed in the present studies may be consistent with a role for the thymus in regulating NK activity in vivo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24461/1/0000736.pd

    Formative evaluation of electricity distribution utilities using data envelopment analysis

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    The use of Data Envelopment Analysis (DEA) in the electricity distribution sector has been prolific in the number of papers published in research journals. However, while numerous studies have been documented, they have mostly been summative. Their aim has been predominantly descriptive and classificatory. This paper argues that evaluations of a formative nature are more effective than summative studies in promoting a better understanding of the structures and processes of electricity distribution utilities and, consequently, are more appropriate to contribute to performance improvement. To illustrate the use of DEA for formative evaluation, and highlight some of the difficulties of using DEA in practice, this paper compares the cost-efficiency of the Portuguese electricity distribution companies from 2002 to 2006. A dynamic analysis using Malmquist Indices is also conducted in order to evaluate the changes in productivity over this period. Our analysis shows that the application of DEA for formative purposes meets some difficulties. In particular it shows that while the modelling of productivity/efficiency scores using DEA is relatively straightforward, it is comparatively more difficult to develop models that are economically valid and that produce results with face validity. On the basis of the insights derived from this analysis, the paper provides some recommendations regarding the successful application of DEA for performance improvement

    Opioids exacerbate inflammation in people with well-controlled HIV

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    IntroductionPeople with HIV (PWH) are known to have underlying inflammation and immune activation despite virologic control. Substance use including opioid dependence is common in this population and is associated with increased morbidity and reduced lifespan. The primary objective of the present study termed opioid immunity study (OPIS), was to investigate the impact of chronic opioids in PWH.MethodsThe study recruited people with and without HIV who had opioid use disorder (OUD). Study participants (n=221) were categorized into four groups: HIV+OP+, n=34; HIV-OP+, n=66; HIV+OP-, n=55 and HIV-OP-, n=62 as controls. PWH were virally suppressed on ART and those with OUD were followed in a syringe exchange program with confirmation of OP use by urine drug screening. A composite cytokine score was developed for 20 plasma cytokines that are linked to inflammation. Cellular markers of immune activation (IA), exhaustion, and senescence were determined in CD4 and CD8 T cells. Regression models were constructed to examine the relationships of HIV status and opioid use, controlling for other confounding factors.ResultsHIV+OP+ participants exhibited highest inflammatory cytokines and cellular IA, followed by HIV-OP+ for inflammation and HIV+OP- for IA. Inflammation was found to be driven more by opioid use than HIV positivity while IA was driven more by HIV than opioid use. In people with OUD, expression of CD38 on CD28-CD57+ senescent-like T cells was elevated and correlated positively with inflammation.DiscussionGiven the association of inflammation with a multitude of adverse health outcomes, our findings merit further investigations to understand the mechanistic pathways involved

    A tool to improve pre-selection for deep brain stimulation in patients with Parkinson’s disease

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    Determining the eligibility of patients with Parkinson’s disease (PD) for deep brain stimulation (DBS) can be challenging for general (non-specialised) neurologists. We evaluated the use of an online screening tool (Stimulus) that aims to support appropriate referral to a specialised centre for the further evaluation of DBS. Implementation of the tool took place via an ongoing European multicentre educational programme, currently completed in 15 DBS centres with 208 referring neurologists. Use of the tool in daily practice was monitored via an online data capture programme. Selection decisions of patients referred with the assistance of the Stimulus tool were compared to those of patients outside the screening programme. Three years after the start of the programme, 3,128 patient profiles had been entered. The intention for referral was made for 802 patients and referral intentions were largely in accordance with the tool recommendations. Follow-up at 6 months showed that actual referral took place in only 28%, predominantly due to patients’ reluctance to undergo brain surgery. In patients screened with the tool and referred to a DBS centre, the acceptance rate was 77%, significantly higher than that of the unscreened population (48%). The tool showed a sensitivity of 99% and a specificity of 12% with a positive and negative predictive value of 79 and 75%, respectively. The Stimulus tool is useful in assisting general neurologists to identify appropriate candidates for DBS consideration. The principal reason for not referring potentially eligible patients is their reluctance to undergo brain surgery

    Clustering of cancer among families of cases with Hodgkin Lymphoma (HL), Multiple Myeloma (MM), Non-Hodgkin's Lymphoma (NHL), Soft Tissue Sarcoma (STS) and control subjects

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    <p>Abstract</p> <p>Background</p> <p>A positive family history of chronic diseases including cancer can be used as an index of genetic and shared environmental influences. The tumours studied have several putative risk factors in common including occupational exposure to certain pesticides and a positive family history of cancer.</p> <p>Methods</p> <p>We conducted population-based studies of Hodgkin lymphoma (HL), Multiple Myeloma (MM), non-Hodgkin's Lymphoma (NHL), and Soft Tissue Sarcoma (STS) among male incident case and control subjects in six Canadian provinces. The postal questionnaire was used to collect personal demographic data, a medical history, a lifetime occupational history, smoking pattern, and the information on family history of cancer. The family history of cancer was restricted to first degree relatives and included relationship to the index subjects and the types of tumours diagnosed among relatives. The information was collected on 1528 cases (HL (n = 316), MM (n = 342), NHL (n = 513), STS (n = 357)) and 1506 age ± 2 years and province of residence matched control subjects. Conditional logistic regression analyses adjusted for the matching variables were conducted.</p> <p>Results</p> <p>We found that most families were cancer free, and a minority included two or more affected relatives. HL [(OR<sub>adj </sub>(95% CI) <b>1.79 (1.33, 2.42)]</b>, MM <b>(1.38(1.07, 1.78))</b>, NHL <b>(1.43 (1.15, 1.77)</b>), and STS cases <b>(1.30(1.00, 1.68)) </b>had higher incidence of cancer if any first degree relative was affected with cancer compared to control families. Constructing mutually exclusive categories combining "family history of cancer" (yes, no) and "pesticide exposure ≄10 hours per year" (yes, no) indicated that a positive family history was important for HL <b>(2.25(1.61, 3.15))</b>, and for the combination of the two exposures increased risk for MM <b>(1.69(1.14,2.51))</b>. Also, a positive family history of cancer both with <b>(1.72 (1.21, 2.45)) </b>and without pesticide exposure <b>(1.43(1.12, 1.83)) </b>increased risk of NHL.</p> <p>Conclusion</p> <p>HL, MM, NHL, and STS cases had higher incidence of cancer if any first degree relative affected with cancer compared to control families. A positive family history of cancer and/or shared environmental exposure to agricultural chemicals play an important role in the development of cancer.</p

    Modeling of longitudinal polytomous outcome from complex survey data - application to investigate an association between mental distress and non-malignant respiratory diseases

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    <p>Abstract</p> <p>Background</p> <p>The data from longitudinal complex surveys based on multi-stage sampling designs contain cross-sectional dependencies among units due to clustered nature of the data and within-subject dependencies due to repeated measurements. Special statistical methods are required to analyze longitudinal complex survey data.</p> <p>Methods</p> <p>Statistics Canada's longitudinal National Population Health Survey (NPHS) dataset from the first five cycles (1994/1995 to 2002/2003) was used to investigate the effects of demographic, social, life-style, and health-related factors on the longitudinal changes of mental distress scores among the NPHS participants who self-reported physician diagnosed respiratory diseases, specifically asthma and chronic bronchitis. The NPHS longitudinal sample includes 17,276 persons of all ages. In this report, participants 15 years and older (n = 14,713) were considered for statistical analysis. Mental distress, an ordinal outcome variable (categories: no/low, moderate, and high) was examined. Ordered logistic regression models based on the weighted generalized estimating equations approach were fitted to investigate the association between respiratory diseases and mental distress adjusting for other covariates of interest. Variance estimates of regression coefficients were computed by using bootstrap methods. The final model was used to predict the probabilities of prevalence of no/low, moderate or high mental distress scores.</p> <p>Results</p> <p>Accounting for design effects does not vary the significance of the coefficients of the model. Participants suffering with chronic bronchitis were significantly at a higher risk (OR<sub>adj </sub>= 1.37; 95% CI: 1.12-1.66) of reporting high levels of mental distress compared to those who did not self-report chronic bronchitis. There was no significant association between asthma and mental distress. There was a significant interaction between sex and self-perceived general health status indicating a dose-response relationship. Among females, the risk of mental distress increases with increasing deteriorating (from excellent to very poor) self-perceived general health.</p> <p>Conclusions</p> <p>A positive association was observed between the physician diagnosed self-reported chronic bronchitis and an increased prevalence of mental distress when adjusted for important covariates. Variance estimates of regression coefficients obtained from the sandwich estimator (i.e. not accounting for design effects) were similar to bootstrap variance estimates (i.e. accounting for design effects). Even though these two sets of variance estimates are similar, it is more appropriate to use bootstrap variance estimates.</p
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