A community-based, comparative evaluation of direct agglutination and rK39 strip tests in the early detection of subclinical Leishmania donovani infection

In the Indian state of Bihar, the sensitivities and specificities of direct agglutination tests (DAT) and rK39 test strips for the detection of Leishmania donovani infection in humans were explored and found to be generally good (92%-100%). When 172 asymptomatic individuals [16 'case-contacts' who lived in the same households as past or current, confirmed cases of visceral leishmaniasis (VL) and 156 other subjects from neighbouring households] were tested, the same 36 (21%) individuals, including all 16 'case-contacts', were found seropositive using each type of test. When followed-up after 3 months, 18 of the individuals who had been found seropositive in the baseline survey remained seropositive, and eight (44%) of these had developed symptomatic VL, with amastigotes in their splenic aspirates. Seven (44%) of the 16 'case-contacts' but only one (5%) of the other 20 subjects found seropositive at baseline went on to develop VL within 3 months. Although the strip test appeared slightly better than DAT for predicting the development of VL in the 172 subjects, either type of test may be very useful for the early detection of asymptomatic L. donovani infection and thus the identification of those at relatively high risk of developing VL.     

Synthetic di-sulfated iduronic acid attenuates asthmatic response by blocking T-cell recruitment to inflammatory sites

Identification of carbohydrate sequences that determine affinity to specific chemokines is a critical step for strategies to interfere with chemokine-mediated leukocyte trafficking. Here, we first characterized the development of allergic asthma in Tie2-dependent and inducible Ext1-knockout (Tie2-Ext1^iKO) mice. We showed that heparan sulfate is essential for leukocyte recruitment in the peribronchial region and bronchoalveolar lavage fluid (BALF), and is crucial for induction of airway hyperresponsiveness. Our glycan microarray showed a unique affinity profile of chemokine CCL20 to substructures of heparin and heparin-like oligo/di/monosaccharides. Among them, we identified a synthetic and not naturally occurring monosaccharide, 2,4-O-di-sulfated iduronic acid (Di-S-IdoA), as a potential inhibitor for CCL20–heparan sulfate interaction. Mice injected with Di-S-IdoA via tail vain or nasal inhalation showed attenuated leukocyte recruitment into inflammatory sites and BALF. These results demonstrate a critical role of chemokine–heparan sulfate interaction in the asthma development and Di-S-IdoA as a potential drug for asthma treatment.Asthma is a common allergic disease characterized by chronic airway inflammation, mucus hypersecretion, and airway hyperreactivity to inhaled allergens (1). Despite the importance of T lymphocytes in adaptive immunity and host defense, their accumulation in airway in allergic asthma causes Th2-mediated pulmonary inflammation. The asthmatic inflammatory response is orchestrated by T-cell trafficking network among lung, blood circulation, secondary lymphoid organ, and peripheral tissue (2). Of note, the significant increase of T cells in the airway in asthma is mostly due to T-cell recruitment from regional lymph nodes rather than their proliferation at the inflamed site (3). Therefore, a therapeutic approach that shuts off the trafficking pathway of pathogenic T cells should significantly inhibit the Th2-mediated inflammation in allergic asthma.It is well known that the destination of T-cell trafficking pathway is tightly restricted by the profile of chemokines, lipid chemoattractants, and T-cell chemokine receptors. As a part of immune surveillance, naïve T cells and central memory T cells constantly access secondary lymphoid organs from blood circulation via specialized high endothelial venules (HEVs). The interaction between T cells and HEV cells includes in a stepwise manner (4, 5), L-selectin–dependent tethering and rolling, activation, firm arrest, and transendothelial migration. Besides 6-sulfo sialyl Lewis X as a L-selectin ligand, HEVs constitutively express chemokine CCL21 and CCL19 and attract T cells that express its cognate receptor CCR7 (5). In contrast to this homeostatic homing, circulating T cells interact with inflamed blood vessels in lung after asthmatic exposure to an inhaled allergen. Among numerous combinations of chemokines and their receptors, there is considerable evidence that CCL20 and its cognate receptor CCR6 may contribute to the pathogenesis of asthma (6). CCL20-CCR6 plays a key role in the recruitment of Th17 (7) cells and Th2 cells (8). Indeed, CCL20 is highly enriched on inflammatory epithelium (9) and CCR6 is expressed on memory T cells infiltrated in the lung during allergic inflammation (7). In addition, CCR6-deficient mice have decreased airway responsiveness, and reduced recruitment of eosinophils into lung (10, 11). These findings suggest that CCL20-CCR6 axis is a putative target for the treatment of asthma.Cumulative evidence in vivo and in vitro indicates that chemokines cannot be functionally active in HEVs and inflamed sites without their interaction with heparan sulfate (12). Heparan sulfate protects chemokines from proteolysis, immobilizes them on the endothelium surface and produces chemokine gradients in the vasculature. Heparan sulfate is composed of repeating disaccharide units of uronic acid [glucuronic acid (GlcA) or iduronic acid (IdoA)] and N-acetylglucosamine (GlcNAc) carbohydrates. Some of GlcA (or IdoA) carbohydrates are subsequently O-sulfated, and GlcNAc carbohydrates are partially modified with N-deacetylation and N-sulfation (13). Previous reports have indicated that the sulfation patterns in heparan sulfate are more restricted than expected (14), and the sulfation is associated with respiratory distress (15) and asthma (16). It is believed that there are specific interactions between heparan sulfate and chemokines (17). Nevertheless, the nontemplate nature of long carbohydrate chains (<25,000 disaccharide units) and conformational plasticity still make it difficult to identify the common sequences of heparan sulfate that display affinity to specific chemokines. In this regard, our previously established glycan microarray system (18, 19) is a powerful tool to define the selectivity in heparan sulfate–chemokine interactions.Recently, we established the exostoses-1 (Ext1) gene conditional knockout Tie2-Ext1^iKO mouse model, in which GlcA/IdoA-GlcNAc repeat of heparan sulfate can be abrogated in endothelial cells in a tetracycline-inducible manner (20). In this study, Tie2-Ext1^iKO mouse showed significant reduction of both leukocyte recruitment to lung tissues and of airway hyperresponsiveness in ovalbumin (OVA) asthma model. Moreover, glycan microarray analysis surprisingly identified that an unnatural and synthetic monosaccharide, 2,4-O-di-sulfated iduronic acid (Di-S-IdoA) has a high affinity to recombinant CCL20. Intravenous and inhalation challenges of Di-S-IdoA significantly inhibited the leukocyte infiltration in bronchoalveolar lavage fluid (BALF). Our finding that even a monosaccharide can attenuate airway inflammation suggests its potential use as an antiasthma therapy that can be administered by inhalation.     

Shape-tuned,surface-active and support-free silver oxygen reduction electrocatalyst enabled high performance fully non-PGM alkaline fuel cell

Exploring non-platinum group metal (n-PGM) based efficient oxygen reduction reaction (ORR) electro-catalysts is highly important for realizing advancement in sustainable next generation-alkaline anion exchange membrane fuel cells (AAEMFCs). Herein, we demonstrate a new “hierarchical shape tuning approach” for the synthesis of controlled sized and shaped non-PGM based Ag ORR electro-catalysts with surface active nano-islands. Hierarchical shapes ranging from spherical (S-AgNs), worm-in-sphere, sphere-in-worm and vermiform (worm-like) Ag nanostructures (V-AgNs) were obtained by precisely varying the ratios of capping agent to dual reducing agents in water at ambient conditions. Compared to S-AgNs, V-AgNs revealed a higher mass normalized ORR Tafel activity (0.303 A mg_Ag⁻¹ at 0.9 V), onset (1.06 V) and half wave (0.78 V) potentials and higher retention of limiting current density (>88%) after 5000 cycles in 0.5 M potassium hydroxide (KOH) solution attributable to their unique worm like morphology with surface active nano-islands and support free-nature enabled better catalyst utilization. In a fully “non-PGM AAEMFC” (n-PAAEMFC), V-AgNs exhibited the highest fuel cell activity of 115.6 mW cm⁻² and stable short-term durability (∼240 h) compared to S-AgNs (41.3 mW cm⁻²) and previously reported fully n-PAAEMFCs indicating their potential use in next-generation alkaline fuel cells.

A fully non-PGM alkaline membrane fuel cell with “highest fuel cell activity” was achieved using a hierarchically shape-tuned, small, surface-active, support-free, worm-shaped nano-structured silver oxygen reduction reaction electro-catalyst.     

Trastuzumab Beyond Progression for HER2 Positive Metastatic Breast Cancer: Progression‐Free Survival on First‐Line Therapy Predicts Overall Survival Impact

Trastuzumab beyond first progression in the metastatic setting has been adopted based on limited data suggesting improved outcomes compared to second‐line chemotherapy alone although predictive factors for preferential benefit remain elusive. We conducted a retrospective review of all patients receiving trastuzumab for HER2 + metastatic disease between Jan 1, 1999–June 15, 2011. Univariate and time to event analyses described treatment and survival patterns. Median duration of each line of therapy and overall survival times for covariates, including treatment era (pre versus post Jan 1, 2005), lines of trastuzumab‐based therapy (1 versus 2 versus 3 + ), first‐line chemotherapy partner (docetaxel/paclitaxel versus other) and median exposure to first‐line trastuzumab‐based therapy (=/> versus < cohort median) were estimated. A total of 119 patients received a median of two lines of trastuzumab‐based therapy (range 1–8). Median overall survival was 21.8 months (95% CI = 14.5–27.1 m), by era was 15.6 m (95% CI = 9.7–24.8 m) versus 26.1 m (95% CI = 20.0–39.3 m; p = 0.11) and by lines of trastuzumab‐based therapy received was 10.6 m (95% CI = 5.3–17.4 m) versus 13.9 m (95% CI = 9.5–27.6 m) versus 32.5 m (95% CI = 25–49.4 m) (p = 0.0014). Median overall survival was significantly longer for those receiving taxanes with trastuzumab compared to other first line partners (26.1 m, 95% CI = 17.8–31.4 m versus 14.5 m, 95% CI = 9.4–21.9 m, p = 0.02). Median overall survival with duration of first‐line trastuzumab‐based therapy =/> cohort median was 31.9 m (95% CI = 26.2–52.2 m) versus 10.3 m for shorter durations (95% CI = 6.9–15.6 m; p < 0.0001). Our observations support progression‐free survival on first‐line trastuzumab‐based therapy as a clinically relevant predictive factor for overall survival benefit with the adoption of a trastuzumab beyond progression treatment strategy.     

Disparate outcomes in patients with colorectal cancer: effect of race on long-term survival

BACKGROUND: Increasing evidence suggests significant disparity in colorectal cancer outcomes between black and white patients. Contributing factors may include advanced tumor stage at diagnosis, differences in treatment, more aggressive tumor biology, access to care, and patient comorbidity. HYPOTHESIS: Disparities in colorectal cancer outcomes exist despite similar objective measures of treatment. DESIGN AND SETTING: Ten-year retrospective review of all patients with colorectal cancer using tumor registries at a city hospital (n = 83) and a university medical center (n = 585) in the same city. We assessed stage at diagnosis; curative surgical resection; use of adjuvant treatment; overall, disease-free, and stage-specific survival; and socioeconomic status. Patients with nonwhite, nonblack ethnicity (4% overall) were excluded. Differences in stage and treatments were compared using the chi(2) test, and median survival rates were compared using log-rank tests. RESULTS: Significantly more black patients were treated at the city hospital (53.0%) vs the university medical center (10.6%) (P<.001). No differences were identified in stage distribution or treatments received between hospitals or between black and white patients. Significantly worse survival was noted among patients treated at the city hospital (2.1 vs 5.3 years; P<.001) and among black patients treated at both institutions (city hospital: 1.4 vs 2.1 years, and university hospital: 3.2 vs 5.7 years; P<.001 for both). Disease-free survival rates showed similar significant reductions for black patients at both institutions. There was no association between survival and socioeconomic status at either institution. CONCLUSION: The marked reductions in overall and disease-free survival for black patients with colorectal cancer do not seem to be related to variation in treatment but may be due to biologic factors or non-cancer-related health conditions.     

Vitamin A supplementation induces adipose tissue loss through apoptosis in lean but not in obese rats of the WNIN/Ob strain

Vitamin A is a known regulator of adipose tissue growth. In this paper, we report the possible role of dietary vitamin A supplementation in the regulation of adipose tissue mass, using a novel obese rat model of the WNIN/Ob strain developed at the National Centre for Laboratory Animal Sciences of the National Institute of Nutrition, India. Twenty-four male lean and obese rats of the WNIN/Ob strain were broadly divided into two groups at 7 months of age; each group was subdivided into two subgroups consisting of six lean and six obese rats and they were given diets containing either 2.6 mg or 129 mg vitamin A/kg diet for 2 months. Feeding a high but non-toxic dose of vitamin A (129 mg/kg diet) resulted in a significant reduction in the adiposity index and retroperitoneal white adipose tissue (RPWAT) weight in obese rats while a marginal reduction was observed in lean rats. Further, this treatment resulted in a significantly increased RPWAT apoptotic index and Bax protein expression and a decreased expression of Bcl2 in the lean rats. However, no such changes were observed in the RPWAT of the obese rats subjected to identical treatment. Thus, our data suggests that chronic dietary vitamin A supplementation at a high dose effectively regulates adipose tissue mass both in the lean and obese phenotypes of the WNIN/Ob rat strain, perhaps through different mechanisms.