883 resultados para Gilpin, Mary Ann, 1813-1839.


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OBJECTIVE To describe the CD4 cell count at the start of combination antiretroviral therapy (cART) in low-income (LIC), lower middle-income (LMIC), upper middle-income (UMIC), and high-income (HIC) countries. METHODS Patients aged 16 years or older starting cART in a clinic participating in a multicohort collaboration spanning 6 continents (International epidemiological Databases to Evaluate AIDS and ART Cohort Collaboration) were eligible. Multilevel linear regression models were adjusted for age, gender, and calendar year; missing CD4 counts were imputed. RESULTS In total, 379,865 patients from 9 LIC, 4 LMIC, 4 UMIC, and 6 HIC were included. In LIC, the median CD4 cell count at cART initiation increased by 83% from 80 to 145 cells/μL between 2002 and 2009. Corresponding increases in LMIC, UMIC, and HIC were from 87 to 155 cells/μL (76% increase), 88 to 135 cells/μL (53%), and 209 to 274 cells/μL (31%). In 2009, compared with LIC, median counts were 13 cells/μL [95% confidence interval (CI): -56 to +30] lower in LMIC, 22 cells/μL (-62 to +18) lower in UMIC, and 112 cells/μL (+75 to +149) higher in HIC. They were 23 cells/μL (95% CI: +18 to +28 cells/μL) higher in women than men. Median counts were 88 cells/μL (95% CI: +35 to +141 cells/μL) higher in countries with an estimated national cART coverage >80%, compared with countries with <40% coverage. CONCLUSIONS Median CD4 cell counts at the start of cART increased 2000-2009 but remained below 200 cells/μL in LIC and MIC and below 300 cells/μL in HIC. Earlier start of cART will require substantial efforts and resources globally.

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This paper reports on the results of a research project, on comparing one virtual collaborative environment with a first-person visual immersion (first-perspective interaction) and a second one where the user interacts through a sound-kinetic virtual representation of himself (avatar), as a stress-coping environment in real-life situations. Recent developments in coping research are proposing a shift from a trait-oriented approach of coping to a more situation-specific treatment. We defined as real-life situation a target-oriented situation that demands a complex coping skills inventory of high self-efficacy and internal or external "locus of control" strategies. The participants were 90 normal adults with healthy or impaired coping skills, 25-40 years of age, randomly spread across two groups. There was the same number of participants across groups and gender balance within groups. All two groups went through two phases. In Phase I, Solo, one participant was assessed using a three-stage assessment inspired by the transactional stress theory of Lazarus and the stress inoculation theory of Meichenbaum. In Phase I, each participant was given a coping skills measurement within the time course of various hypothetical stressful encounters performed in two different conditions and a control group. In Condition A, the participant was given a virtual stress assessment scenario relative to a first-person perspective (VRFP). In Condition B, the participant was given a virtual stress assessment scenario relative to a behaviorally realistic motion controlled avatar with sonic feedback (VRSA). In Condition C, the No Treatment Condition (NTC), the participant received just an interview. In Phase II, all three groups were mixed and exercised the same tasks but with two participants in pairs. The results showed that the VRSA group performed notably better in terms of cognitive appraisals, emotions and attributions than the other two groups in Phase I (VRSA, 92%; VRFP, 85%; NTC, 34%). In Phase II, the difference again favored the VRSA group against the other two. These results indicate that a virtual collaborative environment seems to be a consistent coping environment, tapping two classes of stress: (a) aversive or ambiguous situations, and (b) loss or failure situations in relation to the stress inoculation theory. In terms of coping behaviors, a distinction is made between self-directed and environment-directed strategies. A great advantage of the virtual collaborative environment with the behaviorally enhanced sound-kinetic avatar is the consideration of team coping intentions in different stages. Even if the aim is to tap transactional processes in real-life situations, it might be better to conduct research using a sound-kinetic avatar based collaborative environment than a virtual first-person perspective scenario alone. The VE consisted of two dual-processor PC systems, a video splitter, a digital camera and two stereoscopic CRT displays. The system was programmed in C++ and VRScape Immersive Cluster from VRCO, which created an artificial environment that encodes the user's motion from a video camera, targeted at the face of the users and physiological sensors attached to the body.

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BACKGROUND Epidemiological studies show that elevated levels of particulate matter in ambient air are highly correlated with respiratory and cardiovascular diseases. Atmospheric particles originate from a large number of sources and have a highly complex and variable composition. An assessment of their potential health risks and the identification of the most toxic particle sources would require a large number of investigations. Due to ethical and economic reasons, it is desirable to reduce the number of in vivo studies and to develop suitable in vitro systems for the investigation of cell-particle interactions. METHODS We present the design of a new particle deposition chamber in which aerosol particles are deposited onto cell cultures out of a continuous air flow. The chamber allows for a simultaneous exposure of 12 cell cultures. RESULTS Physiological conditions within the deposition chamber can be sustained constantly at 36-37°C and 90-95% relative humidity. Particle deposition within the chamber and especially on the cell cultures was determined in detail, showing that during a deposition time of 2 hr 8.4% (24% relative standard deviation) of particles with a mean diameter of 50 nm [mass median diameter of 100 nm (geometric standard deviation 1.7)] are deposited on the cell cultures, which is equal to 24-34% of all charged particles. The average well-to-well variability of particles deposited simultaneously in the 12 cell cultures during an experiment is 15.6% (24.7% relative standard deviation). CONCLUSIONS This particle deposition chamber is a new in vitro system to investigate realistic cell-particle interactions at physiological conditions, minimizing stress on the cell cultures other than from deposited particles. A detailed knowledge of particle deposition characteristics on the cell cultures allows evaluating reliable dose-response relationships. The compact and portable design of the deposition chamber allows for measurements at any particle sources of interest.

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Prevalence and genetic relatedness were determined for third-generation cephalosporin-resistant Escherichia coli (3GC-R-Ec) detected in Swiss beef, veal, pork, and poultry retail meat. Samples from meat-packing plants (MPPs) processing 70% of the slaughtered animals in Switzerland were purchased at different intervals between April and June 2013 and analyzed. Sixty-nine 3GC-R-Ec isolates were obtained and characterized by microarray, PCR/DNA sequencing, Multi Locus Sequence Typing (MLST), and plasmid replicon typing. Plasmids of selected strains were transformed by electroporation into E. coli TOP10 cells and analyzed by plasmid MLST. The prevalence of 3GC-R-Ec was 73.3% in chicken and 2% in beef meat. No 3GC-R-Ec were found in pork and veal. Overall, the blaCTX-M-1 (79.4%), blaCMY-2 (17.6%), blaCMY-4 (1.5%), and blaSHV-12 (1.5%) β-lactamase genes were detected, as well as other genes conferring resistance to chloramphenicol (cmlA1-like), sulfonamides (sul), tetracycline (tet), and trimethoprim (dfrA). The 3GC-R-Ec from chicken meat often harbored virulence genes associated with avian pathogens. Plasmid incompatibility (Inc) groups IncI1, IncFIB, IncFII, and IncB/O were the most frequent. A high rate of clonality (e.g., ST1304, ST38, and ST93) among isolates from the same MPPs suggests that strains persist at the plant and spread to meat at the carcass-processing stage. Additionally, the presence of the blaCTX-M-1 gene on an IncI1 plasmid sequence type 3 (IncI1/pST3) in genetically diverse strains indicates interstrain spread of an epidemic plasmid. The blaCMY-2 and blaCMY-4 genes were located on IncB/O plasmids. This study represents the first comprehensive assessment of 3GC-R-Ec in meat in Switzerland. It demonstrates the need for monitoring contaminants and for the adaptation of the Hazard Analysis and Critical Control Point concept to avoid the spread of multidrug-resistant bacteria through the food chain.

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Forty methicillin-resistant and -susceptible Staphylococcus pseudintermedius (MRSP and MSSP, respectively) from colonization and infection in dogs and cats were characterized for clonality, antimicrobial, and biocide susceptibility. MSSP were genetically more diverse than MRSP by multi-locus sequence typing and pulsed-field gel electrophoresis. Three different spa types (t06, t02, t05) and two SCCmec types (II-III and V) were detected in the MRSP isolates. All MRSP and two MSSP strains were multidrug-resistant. Several antibiotic resistance genes (mecA, blaZ, tet(M), tet(K), aac(6')-Ie-aph(2')-Ia, aph(3')-III, ant(6)-Ia, sat4, erm(B), lnu(A), dfr(G), and catpC221) were identified by microarray and double mutations in the gyrA and grlA genes and a single mutation in the rpoB gene were detected by sequence analysis. No differences were detected between MSSP and MRSP in the chlorhexidine acetate (CHA) minimum inhibitory concentrations (MICs). However, two MSSP had elevated MIC to triclosan (TCL) and one to benzalkonium chloride and ethidium bromide. One MSSP isolate harboured a qacA gene, while in another a qacB gene was detected. None of the isolates harboured the sh-fabI gene. Three of the biocide products studied had high bactericidal activity (Otodine(®), Clorexyderm Spot Gel(®), Dermocanis Piocure-M(®)), while Skingel(®) failed to achieve a five log reduction in the bacterial counting. S. pseudintermedius have become a serious therapeutic challenge in particular if methicillin- resistance and/or multidrug-resistance are involved. Biocides, like CHA and TCL, seem to be clinically effective and safe topical therapeutic options.

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Purpose: In homeopathy or anthroposophically extended medicine high dilutions are used. They showed significant differences in ultraviolet light (UV) transmission between controls and different dilution levels. Exposing such dilutions to physical factors such as UV light or elevated temperature (37�C) yielded significantly different UV transmissions values compared to unexposed dilutions. The aim was to test whether electromagnetic fields (EMF) of a mobile phone affect the UV absorbance of dilutions of Atropa belladonna (Ab) and quartz. Methods: Commercially available dilutions of Ab 4x, 6x, 12x, 15x, 30x and of quartz 6x, 12x, 15x, 30x were investigated. On 5 days, 4 samples of each dilution were exposed to the EMF by a mobile phone at 900MHz (GSM) with an output power of 2W for 3 h. Control samples were kept in a separate room. UV-absorbance of the samples in the range from 190 to 340 nm was measured in randomized order. The average absorbance from 200 to 340 nm and from 200 to 240 nm was compared between exposed and unexposed samples by a dependent t-test. Results: Between unexposed and exposed dilutions of Ab and quartz no significant differences were detected, except for quartz 12x over the range from 200 to 340 nm. Conclusion: Exposure of high dilutions of Ab and quartz to GSM EMF of a mobile phone did not alter UV absorbance of these dilutions.

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Purpose: Artistic speech therapy is applied in anthroposophically extended medicine to treat several diseases. The aim is to understand the physiology by investigating the effect of inner and heard speech on brain hemodynamics and oxygenation and analyzing whether these changes were affected by changes in arterial carbon dioxide pressure. Methods: In 29 healthy adult volunteers changes in cerebral absolute oxyhemoglobin ([O2Hb]), deoxyhemoglobin ([HHb]), total hemoglobin ([tHb]) concentrations and tissue oxygen saturation (StO2) were measured by functional near-infrared spectroscopy (fNIRS). End-tidal CO2 (PETCO2) was assessed by capnography. Each subject performed six tasks: inner speech, heard speech from a person and heard speech from a record with each two different recitation texts: hexameter and alliteration according to a randomized crossover design. Results: Significant changes during tasks: A decrease in StO2, [O2Hb], [tHb] and PETCO2 (only for inner speech); an increase in [HHb]. There was a significant difference between hexameter and alliteration. Particularly, changes in [tHb] at the left prefrontal cortex during tasks and after them were statistically different. Furthermore we found significant relations between changes in [O2Hb], [HHb], [tHb] or StO2 and the participants’ age, the baseline PETCO2, or certain speech tasks. Conclusion: During the inner speech, hyperventilation led to a lower PETCO2 (hypocapnia). During heard speech no significant changes in PETCO2 occurred. But decreases in StO2, [O2Hb], [tHb] suggest hypocapnia also here. Hexameter and alliteration led to different changes in [tHb]. Consequently, our parameters are affected by an interplay of both PETCO2 response and task dependent functional brain activity.

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Cerebral electrical activity is highly nonstationary because the brain reacts to ever changing external stimuli and continuously monitors internal control circuits. However, a large amount of energy is spent to maintain remarkably stationary activity patterns and functional inter-relations between different brain regions. Here we examine linear EEG correlations in the peri-ictal transition of focal onset seizures, which are typically understood to be manifestations of dramatically changing inter-relations. Contrary to expectations we find stable correlation patterns with a high similarity across different patients and different frequency bands. This skeleton of spatial correlations may be interpreted as a signature of standing waves of electrical brain activity constituting a dynamical ground state. Such a state could promote the formation of spatiotemporal neuronal assemblies and may be important for the integration of information stemming from different local circuits of the functional brain network.

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Increased pulmonary artery pressure is a well-known phenomenon of hypoxia and is seen in patients with chronic pulmonary diseases, and also in mountaineers on high altitude expedition. Different mediators are known to regulate pulmonary artery vessel tone. However, exact mechanisms are not fully understood and a multimodal process consisting of a whole panel of mediators is supposed to cause pulmonary artery vasoconstriction. We hypothesized that increased hypoxemia is associated with an increase in vasoconstrictive mediators and decrease of vasodilatators leading to a vasoconstrictive net effect. Furthermore, we suggested oxidative stress being partly involved in changement of these parameters. Oxygen saturation (Sao2) and clinical parameters were assessed in 34 volunteers before and during a Swiss research expedition to Mount Muztagh Ata (7549 m) in Western China. Blood samples were taken at four different sites up to an altitude of 6865 m. A mass spectrometry-based targeted metabolomic platform was used to detect multiple parameters, and revealed functional impairment of enzymes that require oxidation-sensitive cofactors. Specifically, the tetrahydrobiopterin (BH4)-dependent enzyme nitric oxide synthase (NOS) showed significantly lower activities (citrulline-to-arginine ratio decreased from baseline median 0.21 to 0.14 at 6265 m), indicating lower NO availability resulting in less vasodilatative activity. Correspondingly, an increase in systemic oxidative stress was found with a significant increase of the percentage of methionine sulfoxide from a median 6% under normoxic condition to a median level of 30% (p<0.001) in camp 1 at 5533 m. Furthermore, significant increase in vasoconstrictive mediators (e.g., tryptophan, serotonin, and peroxidation-sensitive lipids) were found. During ascent up to 6865 m, significant altitude-dependent changes in multiple vessel-tone modifying mediators with excess in vasoconstrictive metabolites could be demonstrated. These changes, as well as highly significant increase in systemic oxidative stress, may be predictive for increase in acute mountain sickness score and changes in Sao2.

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OBJECTIVES Cotrimoxazole prophylactic treatment (CPT) prevents opportunistic infections in HIV-infected or HIV-exposed children, but estimates of the effectiveness in preventing malaria vary. We reviewed studies that examined the effect of CPT on incidence of malaria in children in sub-Saharan Africa. METHODS We searched PubMed and EMBASE for randomised controlled trials (RCTs) and cohort studies on the effect of CPT on incidence of malaria and mortality in children and extracted data on the prevalence of sulphadoxine-pyrimethamine resistance-conferring point mutations. Incidence rate ratios (IRR) from individual studies were combined using random effects meta-analysis; confounder-adjusted estimates were used for cohort studies. The importance of resistance was examined in meta-regression analyses. RESULTS Three RCTs and four cohort studies with 5039 children (1692 HIV-exposed; 2800 HIV-uninfected; 1486 HIV-infected) were included. Children on CPT were less likely to develop clinical malaria episodes than those without prophylaxis (combined IRR 0.37, 95% confidence interval: 0.21-0.66), but there was substantial between-study heterogeneity (I-squared = 94%, P < 0.001). The protective efficacy of CPT was highest in an RCT from Mali, where the prevalence of antifolate resistant plasmodia was low. In meta-regression analyses, there was some evidence that the efficacy of CPT declined with increasing levels of resistance. Mortality was reduced with CPT in an RCT from Zambia, but not in a cohort study from Côte d'Ivoire. CONCLUSIONS Cotrimoxazole prophylactic treatment reduces incidence of malaria and mortality in children in sub-Saharan Africa, but study designs, settings and results were heterogeneous. CPT appears to be beneficial for HIV-infected and HIV-exposed as well as HIV-uninfected children.

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The incidence of Kaposi's Sarcoma (KS) is high in South Africa but the impact of antiretroviral therapy (ART) is not well defined. We examined incidence and survival of KS in HIV-infected patients enrolled in South African ART programs. We analyzed data of three ART programs: Khayelitsha township and Tygerberg Hospital programs in Cape Town and Themba Lethu program in Johannesburg. We included patients aged >16 years. ART was defined as a regimen of at least three drugs. We estimated incidence rates of KS for patients on ART and not on ART. We calculated Cox models adjusted for age, sex and time-updated CD4 cell counts and HIV-1 RNA. A total of 18,254 patients (median age 34.5 years, 64% female, median CD4 cell count at enrolment 105 cells/μL) were included. During 37,488 person-years follow-up 162 patients developed KS. The incidence was 1,682/100,000 person-years (95% confidence interval [CI] 1,406-2,011) among patients not receiving ART and 138/100,000 person-years (95% CI 102-187) among patients on ART. The adjusted hazard ratio comparing time on ART with time not on ART was 0.19 (95% CI 0.13-0.28). Low CD4 cell counts (time-updated) and male sex were also associated with KS. Estimated survival of KS patients at one year was 72.2% (95% CI 64.9-80.2) and higher in men than in women. The incidence of KS is substantially lower on ART than not on ART. Timely initiation of ART is essential to prevent KS and KS-associated morbidity and mortality in South Africa and other regions in Africa with a high burden of HIV.

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Congenital distal renal tubular acidosis (dRTA) from mutations of the B1 subunit of the V-ATPase is considered an autosomal recessive disease. We analyzed a dRTA kindred with a truncation-mutation of B1 (p.Phe468fsX487) previously shown to have failure of assembly into the V1 domain of the V-ATPase. All heterozygous carriers in this kindred have normal plasma bicarbonate concentrations, thus evaded the diagnosis of RTA. However, inappropriately high urine pH, hypocitraturia, and hypercalciuria are present either individually or in combination in the heterozygotes at baseline. Two of the heterozygotes studied also have inappropriate urinary acidification with acute ammonium chloride loading and impaired urine-blood pCO2 gradient during bicarbonaturia indicating presence of H+ gradient and flux defects. In normal human renal papillae, wild type B1 is located primarily on the plasma membrane but papilla from one of the heterozygote who had kidney stones had renal tissue secured from surgery showed B1 in both plasma membrane as well as a diffuse intracellular staining. Titrating increasing amounts of the mutant B1 subunit did not exhibit negative dominance over the expression, cellular distribution, or H+-pump activity of the wild type B1 in mammalian HEK293 cells and in V-ATPase-deficient S. cerevisiae. This is the first demonstration of renal acidification defects and nephrolithiasis in heterozygous carriers of mutant B1 subunit; which cannot be attributable to negative dominance. We propose that heterozygosity may lead to mild real acidification defects due to haploinsufficiency. B1 heterozygosity should be considered in patients with calcium nephrolithiasis and urinary abnormalities such as alkalinuria or hypocitraturia.

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In several studies of antiretroviral treatment (ART) programs for persons with human immunodeficiency virus infection, investigators have reported that there has been a higher rate of loss to follow-up (LTFU) among patients initiating ART in recent years than among patients who initiated ART during earlier time periods. This finding is frequently interpreted as reflecting deterioration of patient retention in the face of increasing patient loads. However, in this paper we demonstrate by simulation that transient gaps in follow-up could lead to bias when standard survival analysis techniques are applied. We created a simulated cohort of patients with different dates of ART initiation. Rates of ART interruption, ART resumption, and mortality were assumed to remain constant over time, but when we applied a standard definition of LTFU, the simulated probability of being classified LTFU at a particular ART duration was substantially higher in recently enrolled cohorts. This suggests that much of the apparent trend towards increased LTFU may be attributed to bias caused by transient interruptions in care. Alternative statistical techniques need to be used when analyzing predictors of LTFU-for example, using "prospective" definitions of LTFU in place of "retrospective" definitions. Similar considerations may apply when analyzing predictors of LTFU from treatment programs for other chronic diseases.

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BACKGROUND The CD4 cell count or percent (CD4%) at the start of combination antiretroviral therapy (cART) is an important prognostic factor in children starting therapy and an important indicator of program performance. We describe trends and determinants of CD4 measures at cART initiation in children from low-, middle-, and high-income countries. METHODS We included children aged <16 years from clinics participating in a collaborative study spanning sub-Saharan Africa, Asia, Latin America, and the United States. Missing CD4 values at cART start were estimated through multiple imputation. Severe immunodeficiency was defined according to World Health Organization criteria. Analyses used generalized additive mixed models adjusted for age, country, and calendar year. RESULTS A total of 34,706 children from 9 low-income, 6 lower middle-income, 4 upper middle-income countries, and 1 high-income country (United States) were included; 20,624 children (59%) had severe immunodeficiency. In low-income countries, the estimated prevalence of children starting cART with severe immunodeficiency declined from 76% in 2004 to 63% in 2010. Corresponding figures for lower middle-income countries were from 77% to 66% and for upper middle-income countries from 75% to 58%. In the United States, the percentage decreased from 42% to 19% during the period 1996 to 2006. In low- and middle-income countries, infants and children aged 12-15 years had the highest prevalence of severe immunodeficiency at cART initiation. CONCLUSIONS Despite progress in most low- and middle-income countries, many children continue to start cART with severe immunodeficiency. Early diagnosis and treatment of HIV-infected children to prevent morbidity and mortality associated with immunodeficiency must remain a global public health priority.