Exercise Increases Pancreatic β-cell Viability In A Model Of Type 1 Diabetes Through Il-6 Signaling.

Type 1 diabetes (T1D) is provoked by an autoimmune assault against pancreatic β cells. Exercise training enhances β-cell mass in T1D. Here, we investigated how exercise signals β cells in T1D condition. For this, we used several approaches. Wild-type and IL-6 knockout (KO) C57BL/6 mice were exercised. Afterward, islets from control and trained mice were exposed to inflammatory cytokines (IL-1β plus IFN-γ). Islets from control mice and β-cell lines (INS-1E and MIN6) were incubated with serum from control or trained mice or medium obtained from 5-aminoimidazole-4 carboxamide1-β-d-ribofuranoside (AICAR)-treated C2C12 skeletal muscle cells. Subsequently, islets and β cells were exposed to IL-1β plus IFN-γ. Proteins were assessed by immunoblotting, apoptosis was determined by DNA-binding dye propidium iodide fluorescence, and NO(•) was estimated by nitrite. Exercise reduced 25, 75, and 50% of the IL-1β plus IFN-γ-induced iNOS, nitrite, and cleaved caspase-3 content, respectively, in pancreatic islets. Serum from trained mice and medium from AICAR-treated C2C12 cells reduced β-cell death, induced by IL-1β plus IFN-γ treatment, in 15 and 38%, respectively. This effect was lost in samples treated with IL-6 inhibitor or with serum from exercised IL-6 KO mice. In conclusion, muscle contraction signals β-cell survival in T1D through IL-6.-Paula, F. M. M., Leite, N. C., Vanzela, E. C., Kurauti, M. A., Freitas-Dias, R., Carneiro, E. M., Boschero, A. C., and Zoppi, C. C. Exercise increases pancreatic β-cell viability in a model of type 1 diabetes through IL-6 signaling.

Association Of Single Nucleotide Polymorphisms In The Gene Encoding Glut1 And Diabetic Nephropathy In Brazilian Patients With Type 1 Diabetes Mellitus.

Mesangial cells subject to high extracellular glucose concentrations, as occur in hyperglycaemic states, are unable to down regulate glucose influx, resulting in intracellular activation of deleterious biochemical pathways. A high expression of GLUT1 participates in the development of diabetic glomerulopathy. Variants in the gene encoding GLUT1 (SLC2A1) have been associated to this diabetic complication. The aim of this study was to test whether polymorphisms in SLC2A1 confer susceptibility to diabetic nephropathy (DN) in Brazilian type 1 diabetes patients. Four polymorphisms (rs3820589, rs1385129, rs841847 and rs841848) were genotyped in a Brazilian cohort comprised of 452 patients. A prospective analysis was performed in 155 patients. Mean duration of follow-up was 5.6±2.4years and the incidence of renal events was 18.0%. The rs3820589 presented an inverse association with the prevalence of incipient DN (OR: 0.36, 95% CI: 0.16 - 0.80, p=0.01) and with progression to renal events (HR: 0.20; 95% CI: 0.03 - 0.70; p=0.009). AGGT and AGAC haplotypes were associated with the prevalence of incipient DN and the AGAC haplotype was also associated with the prevalence of established/advanced DN. In conclusion, rs3820589 in the SLC2A1 gene modulates the risk to DN in Brazilian patients with inadequate type 1 diabetes control.

Socioeconomic Differences in Preferences and Willingness-to-Pay for Insulin Delivery Systems in Type 1 and Type 2 Diabetes

Background: An evaluation of patients' preferences is necessary to understand the demand for different insulin delivery systems. The aim of this study was to investigate the association between socioeconomic status (SES) and patients' preferences and willingness to pay (WTP) for various attributes of insulin administration for diabetes management. Methods: We conducted a discrete choice experiment (DCE) to determine patients' preferences and their WTP for hypothetical insulin treatments. Both self-reported annual household income and education completed were used to explore differences in treatment preferences and WTP for different attributes of treatment across different levels of SES. Results: The DCE questionnaire was successfully completed by 274 patients. Overall, glucose control was the most valued attribute by all socioeconomic groups, while route of insulin delivery was not as important. Patients with higher incomes were willing to pay significantly more for better glucose control and to avoid adverse events compared to lower income groups. In addition, they were willing to pay more for an oral short-acting insulin ($Can 71.65 [95% confidence interval, $40.68, $102.62]) compared to the low income group ($Can 9.85 [95% confidence interval, 14.86, 34.56; P < 0.01]). Conversely, there were no differences in preferences when the sample was stratified by level of education. Conclusions: This study revealed that preferences and WTP for insulin therapy are influenced by income but not by level of education. Specifically, the higher the income, the greater desire for an oral insulin delivery system, whereas an inhaled route becomes less important for patients.

The frequency of CD127(low) expressing CD4(+)CD25(high) T regulatory cells is inversely correlated with human T lymphotrophic virus type-1 (HTLV-1) proviral load in HTLV-1-infection and HTLV-1-associated myelopathy/tropical spastic paraparesis

Background: CD4(+)CD25(high) regulatory T (T(Reg)) cells modulate antigen-specific T cell responses, and can suppress anti-viral immunity. In HTLV-1 infection, a selective decrease in the function of T(Reg) cell mediated HTLV-1-tax inhibition of FOXP3 expression has been described. The purpose of this study was to assess the frequency and phenotype of T(Reg) cells in HTLV-1 asymptomatic carriers and in HTLV-1-associated neurological disease (HAM/TSP) patients, and to correlate with measures of T cell activation. Results: We were able to confirm that HTLV-1 drives activation, spontaneous IFN gamma production, and proliferation of CD4+ T cells. We also observed a significantly lower proportion of CTLA-4(+) T(Reg) cells (CD4(+)CD25(high) T cells) in subjects with HAM/TSP patients compared to healthy controls. Ki-67 expression was negatively correlated to the frequency of CTLA-4(+) T(Reg) cells in HAM/TSP only, although Ki-67 expression was inversely correlated with the percentage of CD127(low) T(Reg) cells in healthy control subjects. Finally, the proportion of CD127(low) T(Reg) cells correlated inversely with HTLV-1 proviral load. Conclusion: Taken together, the results suggest that T(Reg) cells may be subverted in HAM/TSP patients, which could explain the marked cellular activation, spontaneous cytokine production, and proliferation of CD4(+) T cells, in particular those expressing the CD25(high)CD127(low) phenotype. T(Reg) cells represent a potential target for therapeutic intervention for patients with HTLV-1-related neurological diseases.

Genetic Diversity on the Integrase Region of the pol Gene among HIV Type 1-Infected Patients Naive for Integrase Inhibitors in Sao Paulo City, Brazil

The presence of mutations associated with integrase inhibitor (INI) resistance among INI-naive patients may play an important clinical role in the use of those drugs Samples from 76 HIV-1-infected subjects naive to INIs were submitted to direct sequencing. No differences were found between naive (25%) subjects and subjects on HAART (75%). No primary mutation associated with raltegravir or elvitegravir resistance was found. However, 78% of sequences showed at least one accessory mutation associated with resistance. The analysis of the 76 IN sequences showed a high polymorphic level on this region among Brazilian HIV-1-infected subjects, including a high prevalence of aa substitutions related to INI resistance. The impact of these findings remains unclear and further studies are necessary to address these questions.

Near full-length genome analysis of low prevalent human immunodeficiency virus type 1 subclade F1 in Sao Paulo, Brazil

Background: The genetic diversity of the human immunodeficiency virus type 1 (HIV-1) is critical to lay the groundwork for the design of successful drugs or vaccine. In this study we aimed to characterize and define the molecular prevalence of HIV-1 subclade F1 currently circulating in Sao Paulo, Brazil. Methods: A total of 36 samples were selected from 888 adult patients residing in Sao Paulo who had previously been diagnosed in two independent studies in our laboratory as being infected with subclade F1 based on pol subgenomic fragment sequencing. Proviral DNA was amplified from the purified genomic DNA of all 36 blood samples by 5 fragments overlapping PCR followed by direct sequencing. Sequence data were obtained from the 5 fragments of pure subclade F1 and phylogenetic trees were constructed and compared with previously published sequences. Subclades F1 that exhibited mosaic structure with other subtypes were omitted from any further analysis Results: Our methods of fragment amplification and sequencing confirmed that only 5 sequences inferred from pol region as subclade F1 also holds true for the genome as a whole and, thus, estimated the true prevalence at 0.56%. The results also showed a single phylogenetic cluster of the Brazilian subclade F1 along with non-Brazilian South American isolates in both subgenomic and the full-length genomes analysis with an overall intrasubtype nucleotide divergence of 6.9%. The nucleotide differences within the South American and Central African F1 strains, in the C2-C3 env, were 8.5% and 12.3%, respectively. Conclusion: All together, our findings showed a surprisingly low prevalence rate of subclade F1 in Brazil and suggest that these isolates originated in Central Africa and subsequently introduced to South America.

Genotypic Characteristics of HIV Type 1 Based on gp120 Hypervariable Region 3 of Isolates from Southern Brazil

The aim of this study was to investigate HIV-1 molecular diversity and the epidemiological profile of HIV-1-infected patients from Ribeirao Preto, Brazil. A nested PCR followed by sequencing of a 302-base pair fragment of the env gene (C2-V3 region) was performed in samples from HIV-1-positive patients. A total of 45 sequences were aligned with final manual adjustments. The phylogenetic analyses showed a higher prevalence of HIV-1 subtype B in the studied population (97.8%) with only one sample yielding an F1 subtype. The viral genotyping prediction showed that CCR5 tropism was the most prevalent in the studied cohort. Geno2pheno analysis showed that R5 and CXCR4 prediction were 69% and 31%, respectively. There was no statistical significance, either in viral load or in CD4(+) T cell count when R5 and X4 prediction groups were compared. Moreover, the GPGR tetramer was the most common V3 loop core motif identified in the HIV-1 strains studied (34.1%) followed by GWGR, identified in 18.1% of the samples. The high level of B subtype in this Brazilian population reinforces the nature of the HIV epidemic in Brazil, and corroborates previous data obtained in the Brazilian HIV-infected population.

Antiretroviral resistance among HIV type 1-infected women first exposed to antiretrovirals during pregnancy: Plasma versus PBMCs

Resistance-associated mutations (RAMs) in plasma samples from HIV-1-infected women who received antiretroviral (ARV) prophylaxis during pregnancy was assessed and correlated with the detection of RAMs in peripheral blood mononuclear cells (PMBCs). The study population was composed of HIV-1-infected women enrolled in a prospective cohort study in Latin America and the Caribbean (NISDI Perinatal Study) as of March 1, 2005, who were diagnosed with HIV-1 infection during the current pregnancy, who received ARVs during pregnancy for prevention of mother-to-child transmission of HIV-1, and who were followed through at least the 6-12 week postpartum visit. Plasma samples collected at enrollment during pregnancy and at 6-12 weeks postpartum were assayed for RAMs. Plasma results were compared to previously described PBMC results from the same study population. Of 819 enrolled subjects, 197 met the eligibility criteria. Nucleic acid amplification was accomplished in 123 plasma samples at enrollment or 6-12 weeks postpartum, and RAMs were detected in 22 (17.9%; 95% CI: 11.7-25.9%). Previous analyses had demonstrated detection of RAMs in PBMCs in 19 (16.1%). There was high concordance between RAMs detected in plasma and PBMC samples, with only eight discordant pairs. The prevalence of RAMs among these pregnant, HIV-1-infected women is high (>15%). Rates of detection of RAMs in plasma and PBMC samples were similar.

Thyroid Hormone Increases TGF-beta 1 in Cardiomyocytes Cultures Independently of Angiotensin II Type 1 and Type 2 Receptors

TH-induced cardiac hypertrophy in vivo is accompanied by increased cardiac Transforming Growth Factor-beta 1 (TGF-beta 1) levels, which is mediated by Angiotensin II type 1 receptors (AT1R) and type 2 receptors (AT2R). However, the possible involvement of this factor in TH-induced cardiac hypertrophy is unknown. In this study we evaluated whether TH is able to modulate TGF-beta 1 in isolated cardiac, as well as the possible contribution of AT1R and AT2R in this response. The cardiac fibroblasts treated with T(3) did not show alteration on TGF-beta 1 expression. However, cardiomyocytes treated with T(3) presented an increase in TGF-beta 1 expression, as well as an increase in protein synthesis. The AT1R blockade prevented the T(3)-induced cardiomyocyte hypertrophy, while the AT2R blockage attenuated this response. The T(3)-induced increase on TGF-beta 1 expression in cardiomyocytes was not changed by the use of AT1R and AT2R blockers. These results indicate that Angiotensin II receptors are not implicated in T(3)-induced increase on TGF-beta expression and suggest that the trophic effects exerted by T(3) on cardiomyocytes are not dependent on the higher TGF-beta 1 levels, since the AT1R and AT2R blockers were able to attenuate the T(3)-induced cardiomyocyte hypertrophy but were not able to attenuate the increase on TGF-beta 1 levels promoted by T(3).

Promoting health in families of children with type 1 diabetes mellitus

This paper presents a study of families of children with type 1 diabetes mellitus, emphasizing the identification of social supports and networks to strengthen interventions aimed at health promotion. The approach selected was a qualitative research, using a case study design. Four families of children with diabetes type 1 were studied, totalling seven participants. Data were collected between April and June 2007, through in-depth interviews and the construction of a genogram and an ecomap. The results presented the families` characterization and testimonies grouped in the following categories: social support, social networks and family roles. To promote care in practice, there is a need to identify the characteristics of each family and resources available that provide better living conditions. We concluded that identifying supports and social networks allows for more personalized care delivery to each family with a view to health promotion.

Cement stabilization of runoff residuals: A study of stabilization/solidification of urban rainfall-runoff residuals in type 1 Portland cement by XRD and Si-29 NMR analysis

Urban rainfall-runoff residuals contain metals such as Cr, Zn, Cu, As, Pb and Cd and are thus reasonable candidates for treatment using Portland cement-based solidification-stabilization (S/S). This research is a study of S/S of urban storm water runoff solid residuals in Portland cement with quicklime and sodium bentonite additives. The solidified residuals were analyzed after 28 days of hydration time using X-ray powder diffraction (XRD) and solid-state Si-29 nuclear magnetic resonance (NMR) spectroscopy. X-ray diffraction (XRD) results indicate that the main cement hydration products are ettringite, calcium hydroxide and hydrated calcium silicates. Zinc hydroxide and lead and zinc silicates are also present due to the reactions of the waste compounds with the cement and its hydration products. Si-29 NMR analysis shows that the coarse fraction of the waste apparently does not interfere with cement hydration, but the fine fraction retards silica polymerization.

Functional polymorphism of the human arylamine N-acetyltransferase type 1 gene caused by (CT)-T-190 and G(560)A mutations

Human N-acetyltransferase type 1 (NAT1) catalyses the N- or O-acetylation of various arylamine and heterocyclic amine substrates and is able to bioactivate several known carcinogens. Despite wide inter-individual variability in activity, historically, NAT1 was considered to be monomorphic in nature. However, recent reports of allelic variation at the NAT1 locus suggest that it may be a polymorphically expressed enzyme. In the present study, peripheral blood mononuclear cell NAT1 activity in 85 individuals was found to be bimodally distributed with approximately 8% of the population being slow acetylators. Subsequent sequencing of the individuals having slow acetylator status showed all to have either a (CT)-T-190 or G(560)A base substitution located in the protein encoding region of the NAT1 gene. The (CT)-T-190 base substitution changed a highly conserved Arg(64), which others have shown to be essential for fully functional NAT1 protein. The (CT)-T-190 mutation has not been reported previously and we have named it NAT1*17. The G(560)A mutation is associated with the base substitutions previously observed in the NAT1*10 allele and this variant (NAT1*14) encodes for a protein with reduced acetylation capacity. A novel method using linear PCR and dideoxy terminators was developed for the detection of NAT1*14 and NAT1*17. Neither of these variants was found in the rapid acetylator population. We conclude that both the (CT)-T-190 (NAT1*17) and G(560)A (NAT1*14) NAT1 structural variants are involved in a distinct NAT1 polymorphism. Because NAT1 can bioactivate several carcinogens, this polymorphism may have implications for cancer risk in individual subjects. (C) 1998 Chapman & Hall Ltd.

DNA packaging by L1 and L2 capsid proteins of bovine papillomavirus type 1

Encapsidation of circular DNA by papillomavirus capsid protein was investigated in Cos-1 cells. Plasmids carrying both an SV40 origin of replication (or) and an E. coli on were introduced into Cos-1 cells by DNA transfection. PV capsid proteins were supplied in trans by recombinant vaccinia viruses. Pseudovirions were purified from infected cells and their packaged DNA was extracted and used to transform E. coil as an indication of packaging efficacy. VLPs assembled from BPV-1 L1 alone packaged little plasmid DNA, whereas VLPs assembled from BPV-1 L1+L2 packaged plasmid DNA at least 50 times more effectively. BPV-1 L1+L2 VLPs packaged a plasmid containing BPV-1 sequence 8.2 +/- 3.1 times more effectively than a plasmid without BW sequences. Using a series of plasmid constructs comprising a core BPV-1 sequence and spacer DNA it was demonstrated that BW VLPs could accommodate a maximum of about 10.2 kb of plasmid DNA, and that longer closed circular DNA was truncated to produce less dense virions with shorter plasmid sequences. The present study suggests that packaging of genome within PV virions involves interaction of L2 protein with specific DNA sequences, and demonstrates that PV pseudovirions have the potential to be used as DNA delivery vectors for plasmids of up to 10.2 kb. (C) 1998 Academic Press.

Crystallization of a trimeric human T cell leukemia virus type 1 gp21 ectodomain fragment as a chimera with maltose-binding protein

We present a novel protein crystallization strategy, applied to the crystallization of human T cell leukemia virus type 1 (HTLV-1) transmembrane protein gp21 lacking the fusion peptide and the transmembrane domain, as a chimera with the Escherichia coli maltose binding protein (MBP). Crystals could not be obtained with a MBP/gp21 fusion protein in which fusion partners were separated by a flexible linker, but were obtained after connecting the MBP C-terminal alpha-helix to the predicted N-terminal alpha-helical sequence of gp21 via three alanine residues. The gp21 sequences conferred a trimeric structure to the soluble fusion proteins as assessed by sedimentation equilibrium and X-ray diffraction, consistent with the trimeric structures of other retroviral transmembrane proteins. The envelope protein precursor, gp62, is likewise trimeric when expressed in mammalian cells. Our results suggest that MBP may have a general application for the crystallization of proteins containing N-terminal alpha-helical sequences.