Perceptions of Tuberculosis Patients on Provider-Initiated HIV Testing and Counseling - A Study from South India

Background

The acceptability and feasibility of provider-initiated HIV testing and counseling (PITC) in many settings across Asia with concentrated HIV epidemics is not known. A pilot study of the PITC policy undertaken within the public health care systems in two districts in India offered the opportunity to understand patient''s perspectives on the process of referral for HIV testing and linking to HIV treatment and care.

Methods

We conducted a cross-sectional study of randomly selected TB patients registered by the TB control program between July and November 2007 in two districts in south India. Trained interviewers met patients shortly after TB diagnosis and administered a structured questionnaire. Patients were assessed regarding their experience with HIV status assessment, referral for counseling and testing, and for HIV-infected patients the counseling itself and subsequent referral for HIV treatment and care.

Results

Of the 568 interviewed TB patients, 455 (80%) reported being referred for HIV testing after they presented to the health facility for investigations or treatment for TB. Over half the respondents reported having to travel long distances and incurred financial difficulties in reaching the Integrated Counselling and Testing Centre (ICTC) and two-thirds had to make more than two visits. Only 48% reported having been counseled before the test. Of the 110 HIV-infected patients interviewed, (including 43 with previously-known positive HIV status and 67 detected by PITC), 89 (81%) reported being referred for anti-retroviral treatment (ART); 82 patients reached the ART centre but only 44 had been initiated on ART.

Conclusions

This study provides the first evidence from India that routine, provider-initiated voluntary HIV testing of TB patients is acceptable, feasible and can be achieved with very high efficiency under programmatic conditions. While PITC is useful in identifying new HIV-infected patients so that they can be successfully linked to ART, the convenience and proximity of testing centres, quality of HIV counseling, and efficiency of ART services need attention.     

Receptor Specificity and Transmission of H2N2 Subtype Viruses Isolated from the Pandemic of 1957

Influenza viruses of the H2N2 subtype have not circulated among humans in over 40 years. The occasional isolation of avian H2 strains from swine and avian species coupled with waning population immunity to H2 hemagglutinin (HA) warrants investigation of this subtype due to its pandemic potential. In this study we examined the transmissibility of representative human H2N2 viruses, A/Albany/6/58 (Alb/58) and A/El Salvador/2/57 (ElSalv/57), isolated during the 1957/58 pandemic, in the ferret model. The receptor binding properties of these H2N2 viruses was analyzed using dose-dependent direct glycan array-binding assays. Alb/58 virus, which contains the 226L/228S amino acid combination in the HA and displayed dual binding to both alpha 2,6 and alpha 2,3 glycan receptors, transmitted efficiently to naïve ferrets by respiratory droplets. Inefficient transmission was observed with ElSalv/57 virus, which contains the 226Q/228G amino acid combination and preferentially binds alpha 2,3 over alpha 2,6 glycan receptors. However, a unique transmission event with the ElSalv/57 virus occurred which produced a 226L/228G H2N2 natural variant virus that displayed an increase in binding specificity to alpha 2,6 glycan receptors and enhanced respiratory droplet transmissibility. Our studies provide a correlation between binding affinity to glycan receptors with terminal alpha 2,6-linked sialic acid and the efficiency of respiratory droplet transmission for pandemic H2N2 influenza viruses.     

Thymoquinone ameliorates chemical induced oxidative stress and β-cell damage in experimental hyperglycemic rats

The present study was aimed to investigate the effect of thymoquinone (TQ) on pancreatic insulin levels, tissue antioxidant and lipid peroxidation (LPO) status in streptozotocin (STZ) nicotinamide (NA) induced diabetic rats. Diabetes was induced in experimental rats by a single intraperitoneal (i.p) injection of STZ (45 mg/kg b.w) dissolved in 0.1 mol/L citrate buffer (pH 4.5), 15 min after the i.p administration of NA (110 mg/kg b.w). Diabetic rats exhibited increased blood glucose with significant decrease in plasma insulin levels. The activities of antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and the levels of low-molecular weight antioxidants Vitamin C, Vitamin E and reduced glutathione (GSH) were decreased while increases in the levels of lipid peroxidation markers were observed in liver and kidney tissues of diabetic control rats as compared to control rats. In addition, diabetic rats showed an obvious decrease in pancreatic insulin levels. Administration of TQ (80 mg/kg b.w) to diabetic rats for 45 days significantly reversed the damage associated with diabetes. Biochemical findings were supported by histological studies. These results indicated that TQ exerts a protective action on pancreatic beta cell function and overcomes oxidative stress through its antioxidant properties.     

Overexpression of α2,3sialyl T-antigen in breast cancer determined by miniaturized glycosyltransferase assays and confirmed using tissue microarray immunohistochemical analysis

Glycan structure alterations during cancer regulate disease progression and represent clinical biomarkers. The study determined the degree to which changes in glycosyltransferase activities during cancer can be related to aberrant cell-surface tumor associated carbohydrate structures (TACA). To this end, changes in sialyltransferase (sialylT), fucosyltransferase (fucT) and galactosyltransferase (galT) activity were measured in normal and tumor tissue using a miniaturized enzyme activity assay and synthetic glycoconjugates bearing terminal LacNAc Type-I (Galβ1-3GlcNAc), LacNAc Type-II (Galβ1-4GlcNAc), and mucin core-1/Type-III (Galβ1-3GalNAc) structures. These data were related to TACA using tissue microarrays containing 115 breast and 26 colon cancer specimen. The results show that primary human breast and colon tumors, but not adjacent normal tissue, express elevated β1,3GalT and α2,3SialylT activity that can form α2,3SialylatedType-IIIglycans (Siaα2-3Galβ1-3GalNAc). Prostate tumors did not exhibit such elevated enzymatic activities. α1,3/4FucT activity was higher in breast, but not in colon tissue. The enzymology based prediction of enhanced α2,3sialylated Type-III structures in breast tumors was verified using histochemical analysis of tissue sections and tissue microarrays. Here, the binding of two markers that recognize Galβ1-3GalNAc (peanut lectin and mAb A78-G/A7) was elevated in breast tumor, but not in normal control, only upon sialidase treatment. These antigens were also upregulated in colon tumors though to a lesser extent. α2,3sialylatedType-III expression correlated inversely with patient HER2 expression and breast metastatic potential. Overall, enzymology measurements of glycoT activity predict truncated O-glycan structures in tumors. High expression of the α2,3sialylated T-antigen O-glycans occur in breast tumors. A transformation from linear core-1 glycan to other epitopes may accompany metastasis.     

Role of Achromobacter xylosoxidans AUM54 in Micropropagation of Endangered Medicinal Plant Naravelia zeylanica (L.) DC

This study was carried out to evaluate the inoculation effects of Achromobacter xylosoxidans AUM54 and Indole-3-butyric acid (IBA) on the growth of the medicinal plant Naravelia zeylanica (L.) DC under micropropagation conditions. Results revealed that the micropropagated shoots treated with the combination of endophytic bacterium and IBA promoted shoot growth, root length, number of roots, chlorophyll content, nitrogen content, antioxidant enzymes, and stress tolerance compared with the control plants. A significant increase in shoot fresh and dry weights (64.65 and 8.85 %), root fresh and dry weights (61.65 and 3.91 %), shoot length (30.17 %), root length (28.57 %) and number of roots (276.9 %) was observed in treated plants over controls. Total chlorophyll and nitrogen content of bacterized plants also treated with IBA showed a 48.39 and 116.66 % increase, respectively, compared with controls. A significant increase in peroxidase (22.52 %) and superoxide dismutase levels (48.38 %) and fewer changes in the polyphenol oxidase level were observed in plants treated with A. xylosoxidans AUM54 and IBA. Moreover, stress ethylene levels were reduced by 21.4 and 14.5 % due to bacterization with A. xylosoxidans AUM54 and IBA treatment during postacclimatization and acclimatization stages, respectively. The shoot primordial with application of A. xylosoxidans AUM54 and IBA (1 mg l^?1) had increased survivability of N. zeylanica plants by 30 % during the acclimatization stage under greenhouse conditions. From the present study it could be inferred that the association of endophytic bacterium A. xylosoxidans AUM54 and IBA with in vitro shoots of N. zeylanica improved root initiation, promoted plant growth and development under micropropagation conditions, reduced stress ethylene levels, and increased survivability during the postacclimatization stage. Therefore, A. xylosoxidans AUM54 along with IBA treatment can be used as a valuable tool for micropropagation of N. zeylanica and other endangered plants.     

Expansion of Parasite-Specific CD4+ and CD8+ T Cells Expressing IL-10 Superfamily Cytokine Members and Their Regulation in Human Lymphatic Filariasis

Background

Lymphatic filariasis (LF) is known to be associated with an increased production of IL-10. The role of the other IL-10 family members in the pathogenesis of infection and/or disease is not known.

Methodology/Principal Findings

We examined the expression patterns of IL-10 family members – IL-19, IL-24 and IL-26 in LF. We demonstrate that both CD4⁺ and CD8⁺ T cells express IL-19, IL-24 and IL-26 and that the frequency of CD4⁺ T cells expressing IL-19 and IL-24 (as well as IL-10) is significantly increased at baseline and following filarial antigen stimulation in patients with LF in comparison to individuals with filarial lymphedema and uninfected individuals. This CD4⁺ T cell expression pattern was associated with increased production of IL-19 and IL-24 by filarial – antigen stimulated PBMC. Moreover, the frequency of CD4⁺ and CD8⁺ T cells expressing IL-26 was significantly increased following filarial antigen stimulation in filarial lymphedema individuals. Interestingly, IL-10 blockade resulted in diminished frequencies of IL-19⁺ and IL-24⁺ T cells, whereas the addition of recombinant IL-10 resulted in significantly increased frequency of IL-19⁺ and IL-24⁺ T cells as well as significantly up regulated IL-19 and IL-24 gene expression, suggesting that IL-10 regulates IL-19 and IL-24 expression in T cells. In addition, IL-1β and IL-23 blockade also induced a diminution in the frequency of IL-19⁺ and IL-24⁺ T cells, indicating a novel role for these cytokines in the induction of IL-19 and IL-24 expressing T cells. Finally, elimination of infection resulted in significantly decreased frequencies of antigen – specific CD4⁺ T cells expressing IL-10, IL-19 and IL-24.

Conclusions

Our findings, therefore, suggest that IL-19 and IL-24 are associated with the regulation of immune responses in active filarial infection and potentially with protection against development of pathology, while IL-26 is predominantly associated with pathology in LF.     

Parasite-Antigen Driven Expansion of IL-5? and IL-5+ Th2 Human Subpopulations in Lymphatic Filariasis and Their Differential Dependence on IL-10 and TGFβ

Background

Two different Th2 subsets have been defined recently on the basis of IL-5 expression – an IL-5⁺Th2 subset and an IL-5⁻Th2 subset in the setting of allergy. However, the role of these newly described CD4⁺ T cells subpopulations has not been explored in other contexts.

Methods

To study the role of the Th2 subpopulation in a chronic, tissue invasive parasitic infection (lymphatic filariasis), we examined the frequency of IL-5⁺IL-4⁺IL-13⁺ CD4⁺ T cells and IL-5⁻IL-4 IL-13⁺ CD4⁺ T cells in asymptomatic, infected individuals (INF) and compared them to frequencies (F_o) in filarial-uninfected (UN) individuals and to those with filarial lymphedema (CP).

Results

INF individuals exhibited a significant increase in the spontaneously expressed and antigen-induced F_o of both Th2 subpopulations compared to the UN and CP. Interestingly, there was a positive correlation between the F_o of IL-5⁺Th2 cells and the absolute eosinophil and neutrophil counts; in addition there was a positive correlation between the frequency of the CD4⁺IL-5⁻Th2 subpopulation and the levels of parasite antigen – specific IgE and IgG4 in INF individuals. Moreover, blockade of IL-10 and/or TGFβ demonstrated that each of these 2 regulatory cytokines exert opposite effects on the different Th2 subsets. Finally, in those INF individuals cured of infection by anti-filarial therapy, there was a significantly decreased F_o of both Th2 subsets.

Conclusions

Our findings suggest that both IL-5⁺ and IL-5⁻Th2 cells play an important role in the regulation of immune responses in filarial infection and that these two Th2 subpopulations may be regulated by different cytokine-receptor mediated processes.     

The binding characteristics and utilization of Aleuria aurantia,Lens culinaris and few other lectins in the elucidation of fucosyltransferase activities resembling cloned FT VI and apparently unique to colon cancer cells

Human colon carcinoma cell fucosyltransferase (FT) in contrast to the FTs of several human cancer cell lines, utilized GlcNAcbeta1,4GlcNAcbeta-O-Bn as an acceptor, the product being resistant to alpha1,6-L-Fucosidase and its formation being completely inhibited by LacNAc Type 2 acceptors. Further, this enzyme was twofold active towards the asialo agalacto glycopeptide as compared to the parent asialoglycopeptide. Only 60% of the GlcNAc moieties were released from [14C]fucosylated asialo agalacto triantennary glycopeptide by jack bean beta-N-acetylhexosaminidase. These alpha1,3-L-fucosylating activities on multiterminal GlcNAc residues and chitobiose were further examined by characterizing the products arising from fetuin triantennary and bovine IgG diantennary glycopeptides and their exoglycosidase-modified derivatives using lectin affinity chromatography. Utilization of [14C]fucosylated glycopeptides with cloned FTs indicated that Lens culinaris lectin and Aleuria aurantia lectin (AAL) required, respectively, the diantennary backbone and the chitobiose core alpha1,6-fucosyl residue for binding. The outer core alpha1,3- but not the alpha-1,2-fucosyl residues decreased the binding affinity of AAL. The AAL-binding fraction from [14C]fucosylated asialo fetuin, using colon carcinoma cell extract, contained 60% Endo F/PNGaseF resistant chains. Similarly AAL-binding species from [14C]fucosylated TFA-treated bovine IgG using colon carcinoma cell extract showed significant resistance to endo F/PNGaseF. However, no such resistance was found with the corresponding AAL non- and weak-binding species. Thus colon carcinoma cells have the capacity to fucosylate the chitobiose core in glycoproteins, and this alpha1,3-L-fucosylation is apparently responsible for the AAL binding of glycoproteins. A cloned FT VI was found to be very similar to this enzyme in acceptor substrate specificities. The colon cancer cell FT thus exhibits four catalytic roles, i.e., alpha1,3-L-fucosylation of: (a) Galbeta1,4GlcNAcbeta-; (b) multiterminal GlcNAc units in complex type chain; (c) the inner core chitobiose of glycopeptides and glycoproteins; and (d) the nonreducing terminal chiotobiose unit.     

Rapid prototyping in tissue engineering: challenges and potential

Tissue engineering aims to produce patient-specific biological substitutes in an attempt to circumvent the limitations of existing clinical treatments for damaged tissue or organs. The main regenerative tissue engineering approach involves transplantation of cells onto scaffolds. The scaffold attempts to mimic the function of the natural extracellular matrix, providing a temporary template for the growth of target tissues. Scaffolds should have suitable architecture and strength to serve their intended function. This paper presents a comprehensive review of the fabrication methods, including conventional, mainly manual, techniques and advanced processing methods such as rapid prototyping (RP) techniques. The potential and challenges of scaffold-based technology are discussed from the perspective of RP technology.