871 resultados para Diseases and adverse factors


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Familial hemiplegic migraine type 1 (FHM1) is an autosomal dominant subtype of migraine with aura that is associated with hemiparesis. As with other types of migraine, it affects women more frequently than men. FHM1 is caused by mutations in the CACNA1A gene, which encodes the alpha1A subunit of Cav2.1 channels; the R192Q mutation in CACNA1A causes a mild form of FHM1, whereas the S218L mutation causes a severe, often lethal phenotype. Spreading depression (SD), a slowly propagating neuronal and glial cell depolarization that leads to depression of neuronal activity, is the most likely cause of migraine aura. Here, we have shown that transgenic mice expressing R192Q or S218L FHM1 mutations have increased SD frequency and propagation speed; enhanced corticostriatal propagation; and, similar to the human FHM1 phenotype, more severe and prolonged post-SD neurological deficits. The susceptibility to SD and neurological deficits is affected by allele dosage and is higher in S218L than R192Q mutants. Further, female S218L and R192Q mutant mice were more susceptible to SD and neurological deficits than males. This sex difference was abrogated by ovariectomy and senescence and was partially restored by estrogen replacement, implicating ovarian hormones in the observed sex differences in humans with FHM1. These findings demonstrate that genetic and hormonal factors modulate susceptibility to SD and neurological deficits in FHM1 mutant mice, providing a potential mechanism for the phenotypic diversity of human migraine and aura.

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A cohort of 418 United States Air Force (USAF) personnel from over 15 different bases deployed to Morocco in 1994. This was the first study of its kind and was designed with two primary goals: to determine if the USAF was medically prepared to deploy with its changing mission in the new world order, and to evaluate factors that might improve or degrade USAF medical readiness. The mean length of deployment was 21 days. The cohort was 95% male, 86% enlisted, 65% married, and 78% white.^ This study shows major deficiencies indicating the USAF medical readiness posture has not fully responded to meet its new mission requirements. Lack of required logistical items (e.g., mosquito nets, rainboots, DEET insecticide cream, etc.) revealed a low state of preparedness. The most notable deficiency was that 82.5% (95% CI = 78.4, 85.9) did not have permethrin pretreated mosquito nets and 81.0% (95% CI = 76.8, 84.6) lacked mosquito net poles. Additionally, 18% were deficient on vaccinations and 36% had not received a tuberculin skin test. Excluding injections, the overall compliance for preventive medicine requirements had a mean frequency of only 50.6% (95% CI = 45.36, 55.90).^ Several factors had a positive impact on compliance with logistical requirements. The most prominent was "receiving a medical intelligence briefing" from the USAF Public Health. After adjustment for mobility and age, individuals who underwent a briefing were 17.2 (95% CI = 4.37, 67.99) times more likely to have received an immunoglobulin shot and 4.2 (95% CI = 1.84, 9.45) times more likely to start their antimalarial prophylaxsis at the proper time. "Personnel on mobility" had the second strongest positive effect on medical readiness. When mobility and briefing were included in models, "personnel on mobility" were 2.6 (95% CI = 1.19, 5.53) times as likely to have DEET insecticide and 2.2 (95% CI = 1.16, 4.16) times as likely to have had a TB skin test.^ Five recommendations to improve the medical readiness of the USAF were outlined: upgrade base level logistical support, improve medical intelligence messages, include medical requirements on travel orders, place more personnel on mobility or only deploy personnel on mobility, and conduct research dedicated to capitalize on the powerful effect from predeployment briefings.^ Since this is the first study of its kind, more studies should be performed in different geographic theaters to assess medical readiness and establish acceptable compliance levels for the USAF. ^

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This study was conducted to determine the incidence and etiology of neonatal seizures, and evaluate risk factors for this condition in Harris County, Texas, between 1992 and 1994. Potential cases were ascertained from four sources: discharge diagnoses at local hospitals, birth certificates, death certificates, and a clinical study of neonatal seizures conducted concurrent with this study at a large tertiary care center in Houston, Texas. The neonatal period was defined as the first 28 days of life for term infants, and up to 44 weeks gestation for preterm infants.^ There were 207 cases of neonatal seizures ascertained among 116,048 live births, yielding and incidence of 1.8 per 1000. Half of the seizures occurred by the third day of life, 70% within the first week, and 93% within the first 28 days of life. Among 48 preterm infants with seizures 15 had their initial seizure after the 28th day of life. About 25% of all seizures occurred after discharge from the hospital of birth.^ Idiopathic seizures occurred most frequently (0.5/1000 births), followed by seizures attributed to perinatal hypoxia/ischemia (0.4/1000 births), intracranial hemorrhage (0.2/1000 births), infection of the central nervous system (0.2/1000 births), and metabolic abnormalities (0.1/1000 births).^ Risk factors were evaluated based on birth certificate information, using univariate and multivariate analysis (logistic regression). Factors considered included birth weight, gender, ethnicity, place of birth, mother's age, method of delivery, parity, multiple birth and, among term infants, small birth weight for gestational age (SGA). Among preterm infants, very low birth weight (VLBW, $<$1500 grams) was the strongest risk factor, followed by birth in private/university hospitals with a Level III nursery compared with hospitals with a Level II nursery (RR = 2.9), and male sex (RR = 1.8). The effect of very low birth weight varied according to ethnicity. Compared to preterm infants weighing 2000-2999 grams, non-white VLBW infants were 12.0 times as likely to have seizures; whereas white VLBW infants were 2.5 times as likely. Among term infants, significant risk factors included SGA (RR = 1.8), birth in Level III nursery private/university hospitals versus hospitals with Level II nursery (RR = 2.0), and birth by cesarean section (RR = 2.2). ^

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The purpose of this dissertation was to examine the relationship between key psychosocial and behavioral components of the Transtheoretical Model and the Theory of Reasoned Action for sexual risk reduction in a population of crack cocaine smokers and sex workers, not in drug treatment. ^ The first study examined the results of an analysis of the association between two principal constructs in the Transtheoretical Model, the processes of change and the stages of change for condom use, in a high risk population. In the analysis of variance for all respondents, the overall F-test revealed that people in different stages have different levels of experiential process use, F(3,317) = 17.79, p = 0.0001 and different levels of behavioral process use, F(3,317) = 28.59, p = .0001. For the experiential processes, there was a significant difference between the precontemplation/contemplation stage, and both the action, and maintenance, stages.^ The second study explored the relationship between the Theory of Reasoned Action “beliefs” and the stages-of-change in the same population. In the analysis of variance for all participants, the results indicate that people in different stages did value the positive beliefs differently, F(3,502) = 15.38, p = .0001 but did not value the negative beliefs differently, F(3,502) = 2.08, p = .10. ^ The third study explored differences in stage-of-change by gender, partner type drug use, and HIV status. Three discriminant functions emerged, with a combined χ2(12) = 139.57, p = <.0001. The loading matrix of correlations between predictors and discriminant functions demonstrate that the strongest predictor for distinguishing between the precontemplation/contemplation stage and the preparation, action, and maintenance stages (first function) is partner type (.962). The loadings on the second discriminant function suggest that once partner type has been accounted for, ever having HIV/AIDS (.935) was the best predictor for distinguishing between the first three stages and the maintenance stage. ^ These studies demonstrate that behavioral change theories can contribute important insight to researchers and program planners attempting to alter HIV risk behavior in high-risk populations. ^

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QUESTIONS UNDER STUDY We sought to identify reasons for late human immunodeficiency virus (HIV) testing or late presentation for care. METHODS A structured chart review was performed to obtain data on test- and health-seeking behaviour of patients presenting late with CD4 cell counts below 350 cells/µl or with acquired immunodeficiency syndrome (AIDS), at the Zurich centre of the Swiss HIV Cohort Study between January 2009 and December 2011. Logistic regression analyses were used to compare demographic characteristics of persons presenting late with not late presenters. RESULTS Of 281 patients, 45% presented late, 48% were chronically HIV-infected non-late presenters, and an additional 7% fulfilled the <350 CD4 cells/µl criterion for late presentation but a chart review revealed that lymphopenia was caused by acute HIV infection. Among the late presenters, 60% were first tested HIV positive in a private practice. More than half of the tests (60%) were suggested by a physician, only 7% following a specific risk situation. The majority (88%) of patients entered medical care within 1 month of testing HIV positive. Risk factors for late presentation were older age (odds ratio [OR] for ≥50 vs <30 years: 3.16, p = 0.017), Asian versus Caucasian ethnicity (OR 3.5, p = 0.021). Compared with men who have sex with men (MSM) without stable partnership, MSM in a stable partnership appeared less likely to present late (OR 0.50, p = 0.034), whereas heterosexual men in a stable partnership had a 2.72-fold increased odds to present late (p = 0.049). CONCLUSIONS The frequency of late testing could be reduced by promoting awareness, particularly among older individuals and heterosexual men in stable partnerships.

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OBJECTIVE: Altered microbiota composition, changes in immune responses and impaired intestinal barrier functions are observed in IBD. Most of these features are controlled by proteases and their inhibitors to maintain gut homeostasis. Unrestrained or excessive proteolysis can lead to pathological gastrointestinal conditions. The aim was to validate the identified protease IBD candidates from a previously performed systematic review through a genetic association study and functional follow-up. DESIGN: We performed a genetic association study in a large multicentre cohort of patients with Crohn's disease (CD) and UC from five European IBD referral centres in a total of 2320 CD patients, 2112 UC patients and 1796 healthy controls. Subsequently, we did an extensive functional assessment of the candidate genes to explore their causality in IBD pathogenesis. RESULTS: Ten single nucleotide polymorphisms (SNPs) in four genes were significantly associated with CD: CYLD, USP40, APEH and USP3. CYLD was the most significant gene with the intronically located rs12324931 the strongest associated SNP (pFDR=1.74e-17, OR=2.24 (1.83 to 2.74)). Five SNPs in four genes were significantly associated with UC: USP40, APEH, DAG1 and USP3. CYLD, as well as some of the other associated genes, is part of the ubiquitin proteasome system (UPS). We therefore determined if the IBD-associated adherent-invasive Escherichia coli (AIEC) can modulate the UPS functioning. Infection of intestinal epithelial cells with the AIEC LF82 reference strain modulated the UPS turnover by reducing poly-ubiquitin conjugate accumulation, increasing 26S proteasome activities and decreasing protein levels of the NF-κB regulator CYLD. This resulted in IκB-α degradation and NF-κB activation. This activity was very important for the pathogenicity of AIEC since decreased CYLD resulted in increased ability of AIEC LF82 to replicate intracellularly. CONCLUSIONS: Our results reveal the UPS, and CYLD specifically, as an important contributor to IBD pathogenesis, which is favoured by both genetic and microbial factors.

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The causes of a greening trend detected in the Arctic using the normalized difference vegetation index (NDVI) are still poorly understood. Changes in NDVI are a result of multiple ecological and social factors that affect tundra net primary productivity. Here we use a 25 year time series of AVHRR-derived NDVI data (AVHRR: advanced very high resolution radiometer), climate analysis, a global geographic information database and ground-based studies to examine the spatial and temporal patterns of vegetation greenness on the Yamal Peninsula, Russia. We assess the effects of climate change, gas-field development, reindeer grazing and permafrost degradation. In contrast to the case for Arctic North America, there has not been a significant trend in summer temperature or NDVI, and much of the pattern of NDVI in this region is due to disturbances. There has been a 37% change in early-summer coastal sea-ice concentration, a 4% increase in summer land temperatures and a 7% change in the average time-integrated NDVI over the length of the satellite observations. Gas-field infrastructure is not currently extensive enough to affect regional NDVI patterns. The effect of reindeer is difficult to quantitatively assess because of the lack of control areas where reindeer are excluded. Many of the greenest landscapes on the Yamal are associated with landslides and drainage networks that have resulted from ongoing rapid permafrost degradation. A warming climate and enhanced winter snow are likely to exacerbate positive feedbacks between climate and permafrost thawing. We present a diagram that summarizes the social and ecological factors that influence Arctic NDVI. The NDVI should be viewed as a powerful monitoring tool that integrates the cumulative effect of a multitude of factors affecting Arctic land-cover change.

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(Full text is available at http://www.manu.edu.mk/prilozi). New generation genomic platforms enable us to decipher the complex genetic basis of complex diseases and Balkan Endemic Nephropathy (BEN) at a high-throughput basis. They give valuable information about predisposing Single Nucleotide Polymorphisms (SNPs), Copy Number Variations (CNVs) or Loss of Heterozygosity (LOH) (using SNP-array) and about disease-causing mutations along the whole sequence of candidate-genes (using Next Generation Sequencing). This information could be used for screening of individuals in risk families and moving the main medicine stream to the prevention. They also might have an impact on more effective treatment. Here we discuss these genomic platforms and report some applications of SNP-array technology in a case with familial nephrotic syndrome. Key words: complex diseases, genome wide association studies, SNP, genomic arrays, next generation sequ-encing.

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BACKGROUND Vitamin D deficiency is prevalent in HIV-infected individuals and vitamin D supplementation is proposed according to standard care. This study aimed at characterizing the kinetics of 25(OH)D in a cohort of HIV-infected individuals of European ancestry to better define the influence of genetic and non-genetic factors on 25(OH)D levels. These data were used for the optimization of vitamin D supplementation in order to reach therapeutic targets. METHODS 1,397 25(OH)D plasma levels and relevant clinical information were collected in 664 participants during medical routine follow up visits. They were genotyped for 7 SNPs in 4 genes known to be associated with 25(OH)D levels. 25(OH)D concentrations were analyzed using a population pharmacokinetic approach. The percentage of individuals with 25(OH)D concentrations within the recommended range of 20-40ng/ml during 12 months of follow up and several dosage regimens were evaluated by simulation. RESULTS A one-compartment model with linear absorption and elimination was used to describe 25(OH)D pharmacokinetics, while integrating endogenous baseline plasma concentrations. Covariate analyses confirmed the effect of seasonality, body mass index, smoking habits, the analytical method, darunavir/r and the genetic variant in GC (rs2282679) on 25(OH)D concentrations. 11% of the interindividual variability in 25(OH)D levels was explained by seasonality and other non-genetic covariates and 1% by genetics. The optimal supplementation for severe vitamin D deficient patients was 300000 IU two times per year. CONCLUSIONS This analysis allowed identifying factors associated with 25(OH)D plasma levels in HIV-infected individuals. Improvement of dosage regimen and timing of vitamin D supplementation is proposed based on those results.

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The mitochondrial outer membrane (MOM) separates the mitochondria from the cytoplasm, serving both as a barrier and as a gateway. Protein complexes — believed to be universally conserved in all eukaryotes — reside in the MOM to orchestrate and control metabolite exchange, lipid metabolism and uptake of biopolymers such as protein and RNA. African trypanosomes are the causative agent of the sleeping sickness in humans. The parasites are among the earliest diverging eukaryotes that have bona fide mitochondria capable of oxidative phosphorylation. Trypanosomes have unique mitochondrial biology that concerns their mitochondrial metabolism and their unusual mitochondrial morphology that differs to great extent between life stages. Another striking feature is the organization of the mitochondrial genome that does not encode any tRNA genes, thus all tRNAs needed for mitochondrial translation have to be imported. However, the MOM of T. brucei is essentially unchartered territory. It lacks a canonical protein import machinery and facilitation of tRNA translocation remains completely elusive. Using biochemical fractionation and label-free quantitative mass spectrometry for correlated protein abundance-profiling we were able to identify a cluster of 82 candidate proteins that can be localized to the trypanosomal MOM with high confidence. This enabled us to identify a highly unusual, potentially archaic protein import machinery that might also transport tRNAs. Moreover, two-thirds of the identified polypeptides present on the MOM have never been associated with mitochondria before. 40 proteins share homology with proteins of known functions. The function of 42 proteins remains unknown. 11 proteins are essential for the disease-causing bloodstream form of T. brucei and therefore may be exploited as novel drug targets. A comparison with the outer membrane proteome of yeast defines a set of 17 common proteins that are likely present in the MOM of all eukaryotes. Known factors involved in the regulation of mitochondrial morphology are virtually absent in T. brucei. Interestingly, RNAi-mediated ablation of three outer membrane proteins of unknown function resulted in a collapse of the network-like mitochondrion of insect-stage parasites and therefore directly or indirectly are involved in the regulation of mitochondrial morphology.

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Poor udder health represents a serious problem in dairy production and has been investigated intensively, but heifers generally have not been the main focus of mastitis control. The aim of this study was to evaluate the prevalence, risk factors and consequences of heifer mastitis in Switzerland. The study included 166,518 heifers of different breeds (Swiss Red Pied, Swiss Brown Cattle and Holstein). Monthly somatic cell counts (SCCs) provided by the main dairy breeding organisations in Switzerland were monitored for 3 years; the prevalence of subclinical mastitis (SCM) was determined on the basis of SCCs ≥100,000 cells/mL at the first test date. The probability of having SCM at the first test date during lactation was modelled using logistic regression. Analysed factors included data for the genetic background, morphological traits, geographical region, season of parturition and milk composition. The overall prevalence of SCM in heifers during the period from 2006 to 2010 was 20.6%. Higher frequencies of SCM were present in heifers of the Holstein breed (odds ratio, OR, 1.62), heifers with high fat:protein ratios (OR 1.97) and heifers with low milk urea concentrations combined with high milk protein concentrations (OR 3.97). Traits associated with a low risk of SCM were high set udders, high overall breeding values and low milk breeding values. Heifers with SCM on the first test day had a higher risk of either developing chronic mastitis or leaving the herd prematurely.

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OBJECTIVES To assess the association between presence of periodontal pathogens and recurrence of disease in patients with aggressive periodontitis (AgP) after active periodontal therapy (APT) and further influencing factors. MATERIAL & METHODS Microbiological samples were taken from 73 patients with AgP 5-17 years after APT at 292 sites (deepest site per quadrant). Real-time polymerase chain reactions were used to detect the periodontal pathogens Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola. Uni- and multivariate analyses evaluated the associations between pathogens and recurrence of disease, smoking and adjunctive antibiotic therapy. RESULTS At re-examination A. actinomycetemcomitans could be detected in six patients (8.2%), P. gingivalis in 24 (32.9%), T. forsythia in 31 (42.5%) and T. denticola in 35 (48.0%). Increased levels of T. forsythia and T. denticola at re-examination were significantly associated with recurrence of disease in multivariate analyses (OR: 12.72, p < 0.001; OR 5.55, p = 0.002 respectively). Furthermore, high counts of T. denticola were found in patients with increased percentage of sites with clinical attachment levels (CAL) ≥ 6 mm compared to those with low counts (13.8% versus 3.2%, p = 0.005). CONCLUSION In patients with recurrence of disease T. forsythia and T. denticola were detected more frequently and in higher counts. Furthermore, T. denticola was found more frequently in patients with increased CAL.

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Hyperplastic changes of the neuroendocrine cell system may have the potential to evolve into neoplastic diseases. This is particularly the case in the setting of genetically determined and hereditary neuroendocrine tumor syndromes such as MEN1. The review discusses the MEN1-associated hyperplasia-neoplasia sequence in the development of gastrinomas in the duodenum and glucagon-producing tumors in the pancreas. It also presents other newly described diseases (e.g., glucagon cell adenomatosis and insulinomatosis) in which the tumors are (or most likely) also preceded by islet cell hyperplasia. Finally, the pseudohyperplasia of PP-rich islets in the pancreatic head is defined as a physiologic condition clearly differing from other hyperplastic-neoplastic neuroendocrine diseases.