Factors Contributing to the Delay in Diagnosis and Continued Transmission of Leprosy in Brazil – An Explorative,Quantitative, Questionnaire Based Study

BackgroundLeprosy is a leading cause of preventable disability worldwide. Delay in diagnosis of patients augments the transmission of infection, and allows progression of disease and more severe disability. Delays in diagnosis greater than ten years have been reported in Brazil. To reduce this delay, it is important to identify factors that hinder patients from presenting to doctors, and those that delay doctors from diagnosing patients once they have presented. This study aimed to explore factors associated with the delayed diagnosis of leprosy in Brazil.

Methodology/ Principal Findings

This is an exploratory study using a self-constructed questionnaire delivered to patients attending three leprosy referral clinics across three states in Brazil. Data were analysed to determine associations between variables and the time taken for participants to present to the health-service, and between variables and the time taken for doctors to diagnose participants once they had presented. Participants who suspected they had leprosy but feared community isolation were 10 times more likely to wait longer before consulting a doctor for their symptoms (OR 10.37, 95% CI 2.18–49.45, p = 0.003). Participants who thought their symptoms were not serious had a threefold greater chance of waiting longer before consulting than those who did (OR 3.114, 95% CI 1.235–7.856, p = 0.016). Forty-two point six per cent of participants reported initially receiving a diagnosis besides leprosy. These had a three times greater chance of receiving a later diagnosis of leprosy compared to those not misdiagnosed or not given a diagnosis (OR 2.867, 95% CI 1.288–6.384, p = 0.010).

Conclusions/ Significance

This study implies a need for patient education regarding leprosy symptoms and the reduction of stigma to encourage patients to present. The high rate of misdiagnosis reported suggests a need to increase clinician suspicion of leprosy. Further education regarding disease symptoms in medical school curriculums may be advisable.     

Global gene expression analysis to identify molecular markers of uterine receptivity and embryo implantation

Infertility and spontaneous pregnancy losses are an enduring problem to women's health. The establishment of pregnancy depends on successful implantation, where a complex series of interactions occurs between the heterogeneous cell types of the uterus and blastocyst. Although a number of genes are implicated in embryo-uterine interactions during implantation, genetic evidence suggests that only a small number of them are critical to this process. To obtain a global view and identify novel pathways of implantation, we used a dual screening strategy to analyze the expression of nearly 10,000 mouse genes by microarray analysis. Comparison of implantation and interimplantation sites by a conservative statistical approach revealed 36 up-regulated genes and 27 down-regulated genes at the implantation site. We also compared the uterine gene expression profile of progesterone-treated, delayed implanting mice to that of mice in which delayed implantation was terminated by estrogen. The results show up-regulation of 128 genes and down-regulation of 101 genes after termination of the delayed implantation. A combined analysis of these experiments showed specific up-regulation of 27 genes both at the implantation site and during uterine activation, representing a broad diversity of molecular functions. In contrast, the majority of genes that were decreased in the combined analysis were related to host immunity or the immune response, suggesting the importance of these genes in regulating the uterine environment for the implanting blastocyst. Collectively, we identified genes with recognized roles in implantation, genes with potential roles in this process, and genes whose functions have yet to be defined in this event. The identification of unique genetic markers for the onset of implantation signifies that genome-wide analysis coupled with functional assays is a promising approach to resolve the molecular pathways required for successful implantation.     

Somatic embryogenesis in Simarouba glauca

Frequency of somatic embryogenesis from callus cultures derived from immature cotyledon explants of Simarouba glauca Linn. was highest on solid MS medium supplemented with 11.1 M benzyladenine and 13.42 M -naphthaleneacetic acid. On transfer of the somatic embryos into maturation medium containing half-strength MS medium supplemented with 1.89 M abscisic acid (ABA) and 2% (w/v)sucrose, 20–25 % of embryos germinated within 20 days of culture with distinct cotyledon, hypocotyl and radicle.     

The PPARα agonist fenofibrate suppresses B-cell lymphoma in mice by modulating lipid metabolism

Obesity is associated with an increased risk for malignant lymphoma development. We used Bcr/Abl transformed B cells to determine the impact of aggressive lymphoma formation on systemic lipid mobilization and turnover. In wild-type mice, tumor size significantly correlated with depletion of white adipose tissues (WAT), resulting in increased serum free fatty acid (FFA) concentrations which promote B-cell proliferation in vitro. Moreover, B-cell tumor development induced hepatic lipid accumulation due to enhanced hepatic fatty acid (FA) uptake and impaired FA oxidation. Serum triglyceride, FFA, phospholipid and cholesterol levels were significantly elevated. Consistently, serum VLDL/LDL-cholesterol and apolipoprotein B levels were drastically increased. These findings suggest that B-cell tumors trigger systemic lipid mobilization from WAT to the liver and increase VLDL/LDL release from the liver to promote tumor growth. Further support for this concept stems from experiments where we used the peroxisome proliferator-activated receptor α (PPARα) agonist and lipid-lowering drug fenofibrate that significantly suppressed tumor growth independent of angiogenesis and inflammation. In addition to WAT depletion, fenofibrate further stimulated FFA uptake by the liver and restored hepatic FA oxidation capacity, thereby accelerating the clearance of lipids released from WAT. Furthermore, fenofibrate blocked hepatic lipid release induced by the tumors. In contrast, lipid utilization in the tumor tissue itself was not increased by fenofibrate which correlates with extremely low expression levels of PPARα in B-cells. Our data show that fenofibrate associated effects on hepatic lipid metabolism and deprivation of serum lipids are capable to suppress B-cell lymphoma growth which may direct novel treatment strategies. This article is part of a Special Issue entitled Lipid Metabolism in Cancer.     

Human immunodeficiency virus type 1 escapes from RNA interference-mediated inhibition

Short-term assays have suggested that RNA interference (RNAi) may be a powerful new method for intracellular immunization against human immunodeficiency virus type 1 (HIV-1) infection. However, RNAi has not yet been shown to protect cells against HIV-1 in long-term virus replication assays. We stably introduced vectors expressing small interfering RNAs (siRNAs) directed against the HIV-1 genome into human T cells by retroviral transduction. We report here that an siRNA directed against the viral Nef gene (siRNA-Nef) confers resistance to HIV-1 replication. This block in replication is not absolute, and HIV-1 escape variants that were no longer inhibited by siRNA-Nef appeared after several weeks of culture. These RNAi-resistant viruses contained nucleotide substitutions or deletions in the Nef gene that modified or deleted the siRNA-Nef target sequence. These results demonstrate that efficient inhibition of HIV-1 replication through RNAi is possible in stably transduced cells. Therefore, RNAi could become a realistic gene therapy approach with which to overcome the devastating effect of HIV-1 on the immune system. However, as is known for antiviral drug therapy against HIV-1, antiviral approaches involving RNAi should be used in a combined fashion to prevent the emergence of resistant viruses.     

Deregulation of Beclin 1 in patients with tobacco-related oral squamous cell carcinoma

Autophagy is a physiologically regulated and evolutionary conserved process that plays a critical role in degradation of cytoplasmic proteins and other macromolecules within the lysosomes. Beclin-1, the mammalian orthologue of yeast Atg6, is an important mediator of autophagy that has been studied in many human cancers. However, the expression of Beclin-1 has not yet been investigated in oral cancer. We for the first time investigated the expression of Beclin-1 in serum and tissues and correlated it with the clinic-pathological features of oral cancer patients. m-RNA expression of Beclin-1 was evaluated in tumor and normal areas of surgical specimens from 10 oral cancer patients by real-time PCR. Approximately, 8-fold lower expression (p<0.001) of Beclin-1 mRNA was observed in tumor tissue as compared to the normal tissue. Serum levels of Beclin-1 were evaluated by SPR and ELISA. No significant difference was observed in serum Beclin-1 levels in patients as compared to healthy subjects, similarly no correlation was found between serum levels and clinic-pathological parameters such as stage, lymph node involvement and tumor size. Our results demonstrate that down-regulation of Beclin-1 may play an important role in the development and progression of oral cancer possibly by dysregulation of autophagy in tumor cells.     

Directing vanillin production from ferulic acid by increased acetyl-CoA consumption in recombinant Escherichia coli

The amplification of gltA gene encoding citrate synthase of TCA cycle was required for the efficient conversion of acetyl-CoA, generated during vanillin production from ferulic acid, to CoA, which is essential for vanillin production. Vanillin of 1.98 g/L was produced from the E. coli DH5alpha (pTAHEF-gltA) with gltA amplification in 48 h of culture at 3.0 g/L of ferulic acid, which was about twofold higher than the vanillin production of 0.91 g/L obtained by the E. coli DH5alpha (pTAHEF) without gltA amplification. The icdA gene encoding isocitrate dehydrogenase of TCA cycle was deleted to make the vanillin producing E. coli utilize glyoxylate bypass which enables more efficient conversion of acetyl-CoA to CoA in comparison with TCA cycle. The production of vanillin by the icdA null mutant of E. coli BW25113 harboring pTAHEF was enhanced by 2.6 times. The gltA amplification of the glyoxylate bypass in the icdA null mutant remarkably increased the production rate of vanillin with a little increase in the amount of vanillin production. The real synergistic effect of gltA amplification and icdA deletion was observed with use of XAD-2 resin reducing the toxicity of vanillin produced during culture. Vanillin of 5.14 g/L was produced in 24 h of the culture with molar conversion yield of 86.6%, which is the highest so far in vanillin production from ferulic acid using recombinant E. coli.     

ROS-PIASγ cross talk channelizes ATM signaling from resistance to apoptosis during chemosensitization of resistant tumors

With the existing knowledge of ATM''s role in therapeutic resistance, the present study aimed at identifying the molecular mechanisms that influence ATM to oscillate between chemoresistance and chemosensitivity. We observed that the redox status of tumors functions as a major determinant of ATM-dependent ‘resistance-to-apoptosis'' molecular switch. At a low reactive oxygen species (ROS) condition during genotoxic insult, the ATM/sumoylated-IKKγ interaction induced NFκB activation that resisted JNK-mediated apoptosis, whereas increasing cellular ROS restored ATM/JNK apoptotic signaling. A search for the upstream missing link revealed that high ROS induces oxidation and ubiquitin-mediated degradation of PIASγ, thereby disrupting PIASγ-IKKγ cross talk, a pre-requisite for IKKγ sumoylation and subsequent NFκB activation. Interruption in the PIASγ-mediated resistance pathway channels ATM signaling toward ATM/JNK pro-death circuitry. These in vitro results also translated to sensitive and resistant tumor allograft mouse models in which low ROS-induced resistance was over-ruled in PIASγ knockout tumors, while its overexpression inhibited high ROS-dependent apoptotic cues. Cumulatively, our findings identified an unappreciated yet critical combinatorial function of cellular ROS and PIASγ in regulating ATM-mediated chemosensitization of resistant tumors. Thus, therapeutic strategies employing ROS upregulation to inhibit PIASγ during genotoxic therapy may, in future, help to eliminate the problems of NFκB-mediated tumor drug resistance.