41 resultados para Insight
Resumo:
OBJECTIVES HIV infection has been associated with an increased risk of chronic kidney disease (CKD). Little is known about the prevalence of CKD in individuals with high CD4 cell counts prior to initiation of antiretroviral therapy (ART). We sought to address this knowledge gap. METHODS We describe the prevalence of CKD among 4637 ART-naïve adults (mean age 36.8 years) with CD4 cell counts > 500 cells/μL at enrolment in the Strategic Timing of AntiRetroviral Treatment (START) study. CKD was defined by estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2) and/or dipstick urine protein ≥ 1+. Logistic regression was used to identify baseline characteristics associated with CKD. RESULTS Among 286 [6.2%; 95% confidence interval (CI) 5.5%, 6.9%] participants with CKD, the majority had isolated proteinuria. A total of 268 participants had urine protein ≥ 1+, including 41 with urine protein ≥ 2+. Only 22 participants (0.5%) had an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) , including four who also had proteinuria. Baseline characteristics independently associated with CKD included diabetes [adjusted odds ratio (aOR) 1.73; 95% CI 1.05, 2.85], hypertension (aOR 1.82; 95% CI 1.38, 2.38), and race/ethnicity (aOR 0.59; 95% CI 0.37, 0.93 for Hispanic vs. white). CONCLUSIONS We observed a low prevalence of CKD associated with traditional CKD risk factors among ART-naïve clinical trial participants with CD4 cell counts > 500 cells/μL.
Resumo:
Primary adrenal insufficiency (PAI) is a rare condition in childhood which is either inherited (mostly) or acquired. It is characterized by glucocorticoid and maybe mineralocorticoid deficiency. The most common form in children is 21-hydroxylase deficiency, which belongs to the steroid biosynthetic defects causing PAI. Newer forms of complex defects of steroid biosynthesis are P450 oxidoreductase deficiency and (apparent) cortisone reductase deficiency. Other forms of PAI include metabolic disorders, autoimmune disorders and adrenal dysgenesis, e.g. the IMAGe syndrome, for which the underlying genetic defect has been recently identified. Newer work has also expanded the genetic causes underlying isolated, familial glucocorticoid deficiency (FGD). Mild mutations of CYP11A1 or StAR have been identified in patients with FGD. MCM4 mutations were found in a variant of FGD in an Irish travelling community manifesting with PAI, short stature, microcephaly and recurrent infections. Finally, mutations in genes involved in the detoxification of reactive oxygen species were identified in patients with unsolved FGD. Most mutations were found in the enzyme nicotinamide nucleotide transhydrogenase, which uses the mitochondrial proton pump gradient to produce NADPH. NADPH is essential in maintaining high levels of reduced forms of antioxidant enzymes for the reduction of hydrogen peroxide. Similarly, mutations in the gene for TXNRD2 involved in this system were found in FGD patients, suggesting that the adrenal cortex is particularly susceptible to oxidative stress.
Resumo:
OBJECTIVES The aim of this study was to quantify loss to follow-up (LTFU) in HIV care after delivery and to identify risk factors for LTFU, and implications for HIV disease progression and subsequent pregnancies. METHODS We used data on pregnancies within the Swiss HIV Cohort Study from 1996 to 2011. A delayed clinical visit was defined as > 180 days and LTFU as no visit for > 365 days after delivery. Logistic regression analysis was used to identify risk factors for LTFU. RESULTS A total of 695 pregnancies in 580 women were included in the study, of which 115 (17%) were subsequent pregnancies. Median maternal age was 32 years (IQR 28-36 years) and 104 (15%) women reported any history of injecting drug use (IDU). Overall, 233 of 695 (34%) women had a delayed visit in the year after delivery and 84 (12%) women were lost to follow-up. Being lost to follow-up was significantly associated with a history of IDU [adjusted odds ratio (aOR) 2.79; 95% confidence interval (CI) 1.32-5.88; P = 0.007] and not achieving an undetectable HIV viral load (VL) at delivery (aOR 2.42; 95% CI 1.21-4.85; P = 0.017) after adjusting for maternal age, ethnicity and being on antiretroviral therapy (ART) at conception. Forty-three of 84 (55%) women returned to care after LTFU. Half of them (20 of 41) with available CD4 had a CD4 count < 350 cells/μL and 15% (six of 41) a CD4 count < 200 cells/μL at their return. CONCLUSIONS A history of IDU and detectable HIV VL at delivery were associated with LTFU. Effective strategies are warranted to retain women in care beyond pregnancy and to avoid CD4 cell count decline. ART continuation should be advised especially if a subsequent pregnancy is planned.
Resumo:
Multivalent galactosides inhibiting Pseudomonas aeruginosa biofilms may help control this problematic pathogen. To understand the binding mode of tetravalent glycopeptide dendrimer GalAG2 [(Gal-β-OC6H4CO-Lys-Pro-Leu)4(Lys-Phe-Lys-Ile)2Lys-His-Ile-NH2] to its target lectin LecA, crystal structures of LecA complexes with divalent analog GalAG1 [(Gal-β-OC6H4CO-Lys-Pro-Leu)2Lys-Phe-Lys-Ile-NH2] and related glucose-triazole linked bis-galactosides 3u3 [Gal-β-O(CH2)n-(C2HN3)-4-Glc-β-(C2HN3)-[β-Glc-4-(N3HC2)]2-(CH2)n-O-β-Gal (n = 1)] and 5u3 (n = 3) were obtained, revealing a chelate bound 3u3, cross-linked 5u3, and monovalently bound GalAG1. Nevertheless, a chelate bound model better explaining their strong LecA binding and the absence of lectin aggregation was obtained by modeling for all three ligands. A model of the chelate bound GalAG2·LecA complex was also obtained rationalizing its unusually tight LecA binding (KD = 2.5 nM) and aggregation by lectin cross-linking. The very weak biofilm inhibition with divalent LecA inhibitors suggests that lectin aggregation is necessary for biofilm inhibition by GalAG2, pointing to multivalent glycoclusters as a unique opportunity to control P. aeruginosa biofilms.
Resumo:
OBJECTIVE Approximately 85% of cervical cancer cases and deaths occur in resource-constrained countries where best practices for prevention, particularly for women with HIV infection, still need to be developed. The aim of this study was to assess cervical cancer prevention capacity in select HIV clinics located in resource-constrained countries. MATERIALS AND METHODS A cross-sectional survey of sub-Saharan African sites of 4 National Institutes of Health-funded HIV/AIDS networks was conducted. Sites were surveyed on the availability of cervical cancer screening and treatment among women with HIV infection and without HIV infection. Descriptive statistics and χ or Fisher exact test were used as appropriate. RESULTS Fifty-one (65%) of 78 sites responded. Access to cervical cancer screening was reported by 49 sites (96%). Of these sites, 39 (80%) performed screening on-site. Central African sites were less likely to have screening on-site (p = .02) versus other areas. Visual inspection with acetic acid and Pap testing were the most commonly available on-site screening methods at 31 (79%) and 26 (67%) sites, respectively. High-risk HPV testing was available at 29% of sites with visual inspection with acetic acid and 50% of sites with Pap testing. Cryotherapy and radical hysterectomy were the most commonly available on-site treatment methods for premalignant and malignant lesions at 29 (74%) and 18 (46%) sites, respectively. CONCLUSIONS Despite limited resources, most sites surveyed had the capacity to perform cervical cancer screening and treatment. The existing infrastructure of HIV clinical and research sites may provide the ideal framework for scale-up of cervical cancer prevention in resource-constrained countries with a high burden of cervical dysplasia.
New developments providing mechanistic insight into the impact of the microbiota on allergic disease
Resumo:
The increase in allergic diseases over the past several decades is correlated with changes in the composition and diversity of the intestinal microbiota. Microbial-derived signals are critical for instructing the developing immune system and conversely, immune regulation can impact the microbiota. Perturbations in the microbiota composition may be especially important during early-life when the immune system is still developing, resulting in a critical window of opportunity for instructing the immune system. This review highlights recent studies investigating the role of the microbiome in susceptibility or development of allergic diseases with a focus on animal models that provide insight into the mechanisms and pathways involved. Identification of a causal link between reduced microbial diversity or altered microbial composition and increased susceptibility to immune-mediated diseases will hopefully pave the way for better preventive therapies.
Resumo:
Petunia hybrida is a popular bedding plant that has a long history as a genetic model system. We report the whole-genome sequencing and assembly of inbred derivatives of its two wild parents, P. axillaris N and P. inflata S6. The assemblies include 91.3% and 90.2% coverage of their diploid genomes (1.4 Gb; 2n = 14) containing 32,928 and 36,697 protein-coding genes, respectively. The genomes reveal that the Petunia lineage has experienced at least two rounds of hexaploidization: the older gamma event, which is shared with most Eudicots, and a more recent Solanaceae event that is shared with tomato and other solanaceous species. Transcription factors involved in the shift from bee to moth pollination reside in particularly dynamic regions of the genome, which may have been key to the remarkable diversity of floral colour patterns and pollination systems. The high-quality genome sequences will enhance the value of Petunia as a model system for research on unique biological phenomena such as small RNAs, symbiosis, self-incompatibility and circadian rhythms.
Resumo:
Fission track analysis was applied to the Precambrian suites of Madagascar in order to identify the lower-temperature cooling histories and their relationships to the Phanerozoic events that affected the island. Apatite ages range from 431 to 68 Ma, and zircon ages range from 452 to 238 Ma. Thermochronologically, the island can be divided into a southern, central, and northern region each with a subdivision on an east-west basis. The southern region is sharply separated from the central region by strongly contrasting apparent apatite ages over the northwest-southeast striking Ranotsara Shear Zone (RSZ). The change in apparent ages over the RSZ is indicative of later reactivation along younger brittle faults. The central region has the oldest ages of the island and has a diffuse contact to the third region northward. Along the entire western margin of the Precambrian basement initial Paleozoic exhumation was followed by heating (burial by sediments) during Jurassic and Cretaceous times. A decrease in ages along the eastern margin from 119 to 68 Ma coincides with the predicted positions of the Marion hot spot after effects of erosion are considered. On the other hand, these ages may represent progressive opening of the margin in a southward direction together with associated denudation of the rift shoulder. The eastern part of the central region has remained very stable since at least Devonian times, undergoing only long-term very slow exhumation at rates of 1–5 m/Myr.