Human Intestinal Defensin 5 Ameliorates the Sensitization of Colonic Cancer Cells to 5-Fluorouracil

BACKGROUND AND AIM

The increasing dilemma of multidrug-resistant cancer cells in response to currently available chemotherapeutic drugs and their associated side effect(s), calls for the investigation of alternative anticancer advances and molecules. Therefore, the present study aimed to elucidate the combinatorial potential against colon cancer of human defensin 5 in combination with 5-fluorouracil (5-FU), and against 5-FU resistant colon tumor cells.

METHODS

The in vivo combinatorial potential of HD-5 with 5-FU was elucidated in terms of tumor morphometrics, apoptosis assay, surface morphology histology of the colon(s), and transcriptional alterations. Changes in membrane dynamics with mucin expression were evaluated by fluorescence microscopy and histochemistry. The in vitro activity of the peptide/drug conjunction was explored by phase contrast microscopy, MTT, LDH assay, and AO/EtBr staining. Chemoresistance to 5-FU was determined by phase contrast microscopy, MTT assay, annexin V-FITC/PI flow cytometry, and MDR-1, Bak, and Bax expression.

RESULTS

In vivo decreases in tumor parameters, with a marked increase in apoptosis and neutrophil infiltrations indicated restoration of normal architecture with improved mucin content in the treated colons. This happened with substantial changes in key molecular markers of the intrinsic apoptotic cascade. Membrane dynamics revealed that peptides and chemotherapeutic drugs could bind to cancerous cells by taking advantage of altered levels of membrane fluidity.

CONCLUSION

Peptide treatment of drug-resistant Caco-2 cells promotes enhanced 5-FU uptake, in contrast to when cells were treated with 5-FU alone. Hence, HD-5 as an adjunct to 5-FU, exhibited strong cancer cell killing even against 5-FU-resistant tumorigenic cells.

Antibody response to mycobacterial Rpf B protein and its immunodominant peptides in HIV-TB co-infected individuals

Diagnosis of TB at early stages of HIV infection may lead to timely intervention for improving patient outcome. Antibodies to Mycobacterium tuberculosis recombinant RpfB protein and two immunodominant peptides of Rpf B protein were evaluated in the sera of HIV +TB+, HIV+ and HIV- pulmonary TB patients by ELISA. Serum antibodies from 90 % and 65 % of HIV+TB+ patients reacted to recombinant RpfB protein and synthetic peptide RpfP1 respectively. Overall, this study shows that resuscitation promoting factor B elicits humoral antibody response in HIV+TB+ co-infected individuals and be proposed as a potential biomarker for diagnosis of HIV+TB+ patients, however further longitudinal follow up studies are warranted.

In-vivo expressed mycobacterial transcripts as diagnostic targets for pulmonary tuberculosis

The nucleic acid amplification tests (NAATs) such as Xpert MTB/RIF have transformed the TB diagnostic field by significantly increasing the case detection. However, newer improved diagnostic assays are still needed to meet the WHO targets to end TB. Present study is based on a novel approach of utilizing the in-vivo expressed specific mycobacterial transcriptomic biomarkers for the diagnosis of pulmonary tuberculosis (PTB). Total 61 subjects were recruited including smear positive (smear+; n = 15), smear negative (smear-; n = 30) PTB patients and disease controls (n = 16). Transcripts of three mycobacterial genes Rv0986, Rv0971c and Rv3121 were analyzed using real time PCR (qRT-PCR) in sputum samples. qRT-PCR with Rv0986, Rv0971c and Rv3121 identified smear + PTB patients with 100 %, 78.6 % and 86.7 % sensitivity respectively. In smear- PTB patients, both Rv0986 and Rv0971c based qRT-PCR resulted in 63 %, sensitivity whereas Rv3121 identified these patients with ∼40 % sensitivity only. The sensitivity of the assay for smear-patients increased to 85 % when combinatorial analysis of qRT-PCR data for all the three genes was used. Thus, in-vivo expressed mycobacterial transcripts have promising potential as biomarkers for PTB diagnosis.

Evaluation of immunodominant peptides of in vivo expressed mycobacterial antigens in an ELISA-based diagnostic assay for pulmonary tuberculosis

Non-sputum-based biomarker assay is urgently required as per WHO's target product pipeline for diagnosis of tuberculosis. Therefore, the current study was designed to evaluate the utility of previously identified proteins, encoded by in vivo expressed mycobacterial transcripts in pulmonary tuberculosis, as diagnostic targets for a serodiagnostic assay. A total of 300 subjects were recruited including smear+, smear- pulmonary tuberculosis (PTB) patients, sarcoidosis patients, lung cancer patients and healthy controls. Proteins encoded by eight in vivo expressed transcripts selected from previous study including those encoded by two topmost expressed and six RD transcripts (Rv0986, Rv0971, Rv1965, Rv1971, Rv2351c, Rv2657c, Rv2674, Rv3121) were analyzed for B-cell epitopes by peptide arrays/bioinformatics. Enzyme-linked immunosorbent assay was used to evaluate the antibody response against the selected peptides in sera from PTB and controls. Overall 12 peptides were selected for serodiagnosis. All the peptides were initially screened for their antibody response. The peptide with highest sensitivity and specificity was further assessed for its serodiagnostic ability in all the study subjects. The mean absorbance values for antibody response to selected peptide were significantly higher (p<0.001) in PTB patients as compared to healthy controls; however, the sensitivity for diagnosis of PTB was 31% for smear+ and 20% for smear- PTB patients. Thus, the peptides encoded by in vivo expressed transcripts elicited a significant antibody response, but are not suitable candidates for serodiagnosis of PTB.

Association of Micronutrients with Tuberculosis Development in HIV Infected Patients

Human immunodeficiency virus (HIV) infection associated with weakened immune system due to decreased CD4 T cell count favors development of tuberculosis. Effector immune responses are also associated with micronutrient status due to their prominent role in maintaining immune functions. Micronutrient deficiencies are quite common among HIV patients that further result into compromised immunity thus making the conditions even more favorable for mycobacteria to establish disease. So, current study was designed to assess association of different micronutrients with development of TB in HIV patients. Micronutrient levels were measured in asymptomatic HIV patients who were monitored for the development of TB during follow up period (incident TB) within one month to one year and also in symptomatic microbiologically confirmed HIV-TB patients. Among various micronutrients assessed, levels of ferritin were found to be significantly increased (p < 0.05) with significant decreased zinc (p < 0.05) and selenium (p < 0.05) levels in incident TB group as well as in HIV-TB subjects compared to asymptomatic HIV patients who did not develop TB in the follow up period. Importantly, increased levels of ferritin and decreased levels of selenium were significantly associated with development of tuberculosis in HIV patients.

Metabolic switching and cell wall remodelling of Mycobacterium tuberculosis during bone tuberculosis

OBJECTIVES

Bone tuberculosis (TB) is the third most common types of extrapulmonary tuberculosis. It is critical to understand mycobacterial adaptive strategies within bone lesions to identify mycobacterial factors that may have role in disease pathogenesis.

METHODS

Whole genome microarray was used to characterize the in-vivo transcriptome of Mycobacterium tuberculosis (M.tb) within bone TB specimens. Mycobacterial virulent proteins were identified by bioinformatic software. An in vitro osteoblast cell line model was used to study the role of these proteins in bone TB pathogenesis.

RESULTS

914 mycobacterial genes were significantly overexpressed and 1688 were repressed in bone TB specimens. Pathway analysis of differentially expressed genes demonstrated a non-replicative and hypometabolic state of M.tb, reinforcement of the mycobacterial cell wall and induction of DNA damage repair responses, suggesting possible survival strategies of M.tb within bone. Bioinformatics mining of microarray data led to identification of five virulence proteins. The genes encoding these proteins were also upregulated in the in vitro MC3T3 osteoblast cell line model of bone TB. Further, exposure of osteoblast cells to two of these virulence proteins (Rv1046c and Rv3663c) significantly inhibited osteoblast differentiation.

CONCLUSION

M.tb alters its transcriptome to establish infection in bone by upregulating certain virulence genes which play a key role in disturbing bone homeostasis.

Immunological aspects of host-pathogen crosstalk in the co-pathogenesis of diabetes and latent tuberculosis

Introduction

Diabetes is a potent risk factor for the activation of latent tuberculosis and worsens the tuberculosis (TB) treatment outcome. The major reason for mortality and morbidity in diabetic patients is due to their increased susceptibility to TB. Thus, the study was conducted to understand the crosstalk between M. tuberculosis and its host upon latent tuberculosis infection and under hyperglycemic conditions or diabetes.

Methods

An animal model was employed to study the relationship between latent tuberculosis and diabetes. BCG immunization was done in mice before infection with M. tuberculosis, and latency was confirmed by bacillary load, histopathological changes in the lungs and gene expression of hspX, tgs1, tgs3 and tgs5. Diabetes was then induced by a single high dose of streptozotocin (150 mg/kg body weight). Host factors, like various cytokines and MMPs (Matrix metalloproteinases), which play an important role in the containment of mycobacterial infection were studied in vivo and in vitro.

Results

A murine model of latent TB was developed, which was confirmed by CFU counts (<10⁴ in the lungs and spleen) and granuloma formation in lungs in the latent TB group. Also, the gene expression of hspX, tgs1, and tgs5 was upregulated, and after diabetes induction, blood glucose levels were >200 mg/dl. An in vitro study employing a THP-1 macrophage model of latent and active tuberculosis under normal and high glucose conditions showed that dormant bacilli were better contained in the presence of 5.5 mM glucose concentration as compared with active bacilli. However, the killing and restriction efficiency of macrophages decreased, and CFU counts increased significantly with an increase in glucose concentration.

Discussion

The decreased levels of MCP-1, decreased expression of mmp-9, and increased expression of mmp-1 in the latent group at high glucose concentrations could explain the failure of granuloma formation at high glucose conditions.

Diagnosis and biomarkers for ocular tuberculosis: From the present into the future

Tuberculosis is an airborne disease caused by Mycobacterium tuberculosis (Mtb) and can manifest both pulmonary and extrapulmonary disease, including ocular tuberculosis (OTB). Accurate diagnosis and swift optimal treatment initiation for OTB is faced by many challenges combined with the lack of standardized treatment regimens this results in uncertain OTB outcomes. The purpose of this study is to summarize existing diagnostic approaches and recently discovered biomarkers that may contribute to establishing OTB diagnosis, choice of anti-tubercular therapy (ATT) regimen, and treatment monitoring. The keywords ocular tuberculosis, tuberculosis, Mycobacterium, biomarkers, molecular diagnosis, multi-omics, proteomics, genomics, transcriptomics, metabolomics, T-lymphocytes profiling were searched on PubMed and MEDLINE databases. Articles and books published with at least one of the keywords were included and screened for relevance. There was no time limit for study inclusion. More emphasis was placed on recent publications that contributed new information about the pathogenesis, diagnosis, or treatment of OTB. We excluded abstracts and articles that were not written in the English language. References cited within the identified articles were used to further supplement the search. We found 10 studies evaluating the sensitivity and specificity of interferon-gamma release assay (IGRA), and 6 studies evaluating that of tuberculin skin test (TST) in OTB patients. IGRA (Sp = 71-100%, Se = 36-100%) achieves overall better sensitivity and specificity than TST (Sp = 51.1-85.7%; Se = 70.9-98.5%). For nuclear acid amplification tests (NAAT), we found 7 studies on uniplex polymerase chain reaction (PCR) with different Mtb targets, 7 studies on DNA-based multiplex PCR, 1 study on mRNA-based multiplex PCR, 4 studies on loop-mediated isothermal amplification (LAMP) assay with different Mtb targets, 3 studies on GeneXpert assay, 1 study on GeneXpert Ultra assay and 1 study for MTBDRplus assay for OTB. Specificity is overall improved but sensitivity is highly variable for NAATs (excluding uniplex PCR, Sp = 50-100%; Se = 10.5-98%) as compared to IGRA. We also found 3 transcriptomic studies, 6 proteomic studies, 2 studies on stimulation assays, 1 study on intraocular protein analysis and 1 study on T-lymphocyte profiling in OTB patients. All except 1 study evaluated novel, previously undiscovered biomarkers. Only 1 study has been externally validated by a large independent cohort. Future theranostic marker discovery by a multi-omics approach is essential to deepen pathophysiological understanding of OTB. Combined these might result in swift, optimal and personalized treatment regimens to modulate the heterogeneous mechanisms of OTB. Eventually, these studies could improve the current cumbersome diagnosis and management of OTB.

Anti-staphylococcal responses and their relationship with HLA-DR-DQ polymorphism in granulomatosis with polyangiitis: a preliminary evidence of association with disease outcome

Chronic nasal carriage of Staphylococcus aureus (S. aureus) is a risk factor for relapse of granulomatosis with polyangiitis (GPA), and genetic susceptibility to infections and autoimmune diseases is majorly affected by HLA genes. Previous studies have shown the association of HLA Class-II genes with GPA susceptibility. Here, we aim to assess immune responses of GPA patients against S. aureus antigens in relation to the HLA-DR-DQ genes polymorphism to determine the disease outcome. A total of 45 GPA patients and 128 healthy controls during 2010-2012 were included in this case-control study. HLA-DRB1/DQB1 allele typing was performed by polymerase chain reaction-sequence-specific primer (PCR-SSP) method. Immune responses against S. aureus antigens were investigated in 20 active vs. remitting GPA (after 6 months of cyclophosphamide and glucocorticoids) patients by Western blot. Statistical analysis was performed using χ² test and Fisher's exact test. We observed a significant association of DRB1*08, DRB1*16 and DQB1*04 alleles with GPA susceptibility, whereas DRB1*15, DRB1*10 and DQB1*05 alleles were suggested as protective alleles. Among S. aureus antigens, active GPA patients' sera reacted more strongly with 34 and 24 kDa antigens of S. aureus than remitting and healthy control  sera. Furthermore, we observed that the lack of DQB1*06 allele confers complete remission even in the presence of anti-S. aureus antibodies against 24 kDa protein. Our findings suggest that the presence of DQB1*06 allele and S. aureus infection may prolong active disease. Further, our study indicates the potential of using anti-staphylococcal medications for achieving remission in patients having HLA-DQB1*06 allele.

AB0417 SHORT-TERM EFFECT OF METHOTREXATE ON APOLIPOPROTEINS AND LIPID PROFILE IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS

Background

Methotrexate (MTX) forms the first line therapy for rheumatoid arthritis (RA). The cardioprotective effect of MTX is well established, but whether this is just due to control of inflammation, or is also via an effect on serum lipoproteins, is unclear. Although a few studies have studied the effect of the MTX on the traditional lipid profile in RA1, there is no data on the effect of MTX on apolipoproteins (Apo A1, Apo B, ApoB/ApoA1), which are considered better cardiovascular risk predictors than the traditional lipid profile.

Objectives

To determine the short-term effect of MTX on apolipoproteins and traditional lipid profile in patients with active RA.

Methods

DMARD-naïve patients with active RA (SJC≥2 and TJC≥4) who had been enrolled in the multicentre, RCT comparing two different MTX escalation strategies in RA (MEIRA)2 and for whom paired serum samples were available before and after MTX treatment were included. All these patients received MTX monotherapy started at 15 mg/week and escalated to 25 mg/week by 4-8 weeks. Serum levels of apolipoprotein A1 (Apo A1), apolipoprotein B (Apo B), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides (TG) were measured before starting MTX and after 16 weeks of MTX monotherapy. Proatherosclerotic indices (TC/HDL and ApoB/ApoA1) were also calculated.

Results

A total of 103 patients [mean age 40 (8) years, 93 (90%) females, mean BMI 25.1 (4.8) kg/m2, all non-smokers and non-alcoholics] were included. No study participant had comorbid diabetes mellitus or coronary artery disease; none of them were taking glucocorticoids or hypolipidemic drugs. An increase in Apo A1 levels [by a mean of 5.6 mg/dL (p=0.02)], and HDL levels [by a mean of 1.6 mg/dL (p=0.04)] was seen after 16 weeks of MTX monotherapy. Although a numerical increase in levels of TC (mean 4.6 mg/dL, p=0.07), LDL (mean 2 mg/dL, p=0.34) and TG (mean 6.6 mg/dL, p=0.35) was also noted, none of these were statistically significant. No obvious change in Apo B levels and TC/HDL ratio occurred due to MTX therapy. However, the ApoB/ApoA1 ratio decreased significantly from 0.8 to 0.7 (p=0.002) with 16 weeks of MTX therapy (Table 1).

Table 1.

Baseline and end of treatment values of apolipoprotein A1 (Apo A1), apolipoprotein B (Apo B), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), and proatherosclerotic indices (TC/HDL and ApoB/ApoA1).

Parameter (mg/dL)BaselineAfter 16 weeks of MTX therapyp-valueApo A1126.0 (25.1)131.6 (23.4)0.02Apo B92.3 (18.9)92.0 (20.9)0.84ApoB/ApoA10.8 (0.2)0.7 (0.2)0.002TC164.5 (32.4)169.1 (36.8)0.07HDL40.9 (9.8)42.5 (9.7)0.04TC/HDL4.2 (1.1)4.1 (1.1)0.34LDL88.8 (25.2)90.8 (29.8)0.34TG139.8 (69.6)146.4 (91.3)0.35

All values represented as mean (SD).

Apo A1=apolipoprotein A1, ApoB=apolipoprotein B, TC=total cholesterol, LDL=low-density lipoprotein, HDL=high-density lipoprotein, TG=triglycerides

Conclusion

MTX therapy led to a mild but significant increase in HDL, ApoA1 and a reduction in ApoB/ApoA1 over short-term. This could potentially represent one of the mechanisms by which MTX exerts its cardioprotective effect; however, these changes need to be carefully interpreted over longer term and in context of the lipid paradox operating in RA.

References

[1]Navarro-Millán I, Charles-Schoeman C, Yang S, et al. Changes in lipoproteins associated with methotrexate or combination therapy in early rheumatoid arthritis: results from the treatment of early rheumatoid arthritis trial. Arthritis Rheum. 2013;65(6):1430-1438.

[2]Jain S, Dhir V, Aggarwal A, et al. Comparison of two dose escalation strategies of methotrexate in active rheumatoid arthritis: a multicentre, parallel group, randomised controlled trial. Ann Rheum Dis. 2021;80(11):1376-1384.

Disclosure of Interests

None declared

PM2.5 mediated alterations in the in vitro human granuloma and its effect on reactivation of mycobacteria

Exposure to particulate matter pollutant PM_2.5 diminishes the immune response to mycobacterial antigens relevant to contain the infection in the granuloma, thus leading to reactivation of latent bacilli. The present study was therefore designed based on the hypothesis that exposure to PM_2.5 affects the granuloma formation and reactivation of latent mycobacterial bacilli contained in the granuloma. For the sampling of PM_2.5, based on initial standardisations, Teflon filter was selected over the quartz filter. Two different approaches were used to study the effect of PM_2.5 on the human PBMC granuloma formed by Mycobacterium bovis BCG at multiplicity of infection (MOI) 0.1. In the first approach, granuloma formed in the presence of PM_2.5 was loosely packed and ill-defined with significant downregulation of dormancy-associated mycobacterial genes, upregulation of reactivation-associated rpfB gene along with a significant increase in TNFα level without any change in the bacterial load in terms of CFUs. In the second approach, preformed human PBMC granuloma using M. bovis BCG was treated with PM_2.5 that resulted in the disruption of granuloma architecture along with downregulation of not only dormancy-associated genes but also reactivation-associated rpfB gene of mycobacterial bacilli recovered from granuloma. However, there was no significant change in the host cytokine levels. Therefore, it can be inferred that PM_2.5 can modulate the granuloma formation in vitro as well as mycobacterial gene expression in the granuloma with a possible role in the reactivation of latent bacilli.

Distinct interfacial ordering of liquid crystals observed by protein-lipid interactions that enabled the label-free sensing of cytoplasmic protein at the liquid crystal-aqueous interface

Interfaces formed between a lipid decorated liquid crystal (LC) film and an aqueous phase can mimic the bimolecular membrane where interfacially occurring biological phenomena (e.g., lipid-protein interactions, protein adsorption) can be visually monitored by observing the surface-sensitive orientations of LCs. The ordering behavior of LCs at different phospholipid-based LC interfaces (1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) and lysophosphatidic acid (LPA)) were investigated to determine the sensing of an important cytoplasmic protein (juxtamembrane of epidermal growth factor receptor (JM-EGFR)). At both DLPC and LPA decorated interfaces, the LC adopts homeotropic ordering, causing a dark optical appearance under crossed polarizers. Interestingly, upon the introduction of JM-EGFR to these LC-aqueous interfaces, the homeotropic orientation of the LC changed to planar (bright optical appearance), suggesting the potential of the designed system for JM-EGFR sensing. The use of different lipid decorated LC-aqueous interfaces results in the emergence of distinct optical patterns. For example, at a DLPC laden interface, elongated bright domains are observed, whereas a uniform bright texture is observed on an LPA laden interface. The DLPC decorated LC-aqueous interface is found to be highly selective for the sensing of JM-EGFR with a detection limit in the nanomolar concentration region (∼ 50 nM). When compared to spectroscopic and other conventional techniques, the LC-based design is simpler, and it allows the simple and label-free optical sensing of JM-EGFR at fluidic interfaces.

Reactivation of latent tuberculosis through modulation of resuscitation promoting factors by diabetes

The evidence of an association between diabetes and latent tuberculosis infection (LTBI) remains limited and inconsistent. Thus, the study aims to delineate the role of diabetes in activation of latent tuberculosis infection. Murine model of latent tuberculosis and diabetes was developed, bacillary load and gene expression of resuscitation promoting factors (rpfA-E) along with histopathological changes in the lungs and spleen were studied. Treatment for LTBI [Rifampicin (RIF) + Isoniazid (INH)] was also given to latently infected mice with or without diabetes for 4 weeks. Diabetes was found to activate latent tuberculosis as the colony forming unit (CFU) counts were observed to be > 10⁴ in lungs and spleen. The gene expression of hspX was downregulated and that of rpfB and rpfD was observed to be upregulated in latently infected mice with diabetes compared to those without diabetes. However, no significant reduction in the CFU counts was observed after 4 weeks of treatment with RIF and INH. Diabetes helps in the progression of LTBI to active disease mainly through altered expression of resuscitation promoting factors rpfB and rpfD, which can serve as important targets to reduce the shared burden of tuberculosis and diabetes.

Perinatal Outcome in Pregnancies Associated with Hypertension: A Prospective Cohort Study in a Rural Tertiary Care Teaching Hospital of North India

OBJECTIVE

The objective of the study is to know type of hypertension affecting pregnant women and impact on perinatal outcome.

SUBJECT AND METHODS

This is a prospective cohort study; 120 women with hypertensive disorders of pregnancy (HDP) at gestation ≥28 weeks who delivered in our institute were enrolled. Sociodemography, gestational age, mode of delivery, APGAR, birth weight, fetal growth restriction (FGR), and perinatal outcome were recorded. Mean ± standard deviation or proportions, analysis of variance, Chi-square test, and odds ratio were used for statistical analysis.

RESULTS

Preeclampsia (PE) was most prevalent hypertensive disorder of pregnancy (44.2%), followed by eclampsia (27.50%), gestational hypertension (23.3%), and chronic hypertension (CH) (5.0%). In PE group, 61.8% had FGR, 65.5% newborns were preterm, 74.6% had low birth weight, and 54.1% needed neonatal intensive care unit (NICU) admission. In eclampsia group, 42.9% had fetal growth restriction, 65.7% preterm, 80% low birth weight, and 78.6% NICU admission. PE women delivered more fetal growth-restricted babies with odd ratio of 2.37 (95% confidence interval [CI]: 1.15, 4.9) and at lower gestation with odd ratio of 2.00 (95% CI: 0.95, 4.21). Eclampsia group had more newborn with low APGAR 1 min, NICU admissions, and those requiring ventilator with odds ratio of 3.10 (95% CI: 1.37, 7.03), 4.48 (95% CI: 1.64, 12.24), and 4.09 (95% CI: 1.6, 10.46), respectively. Perinatal mortality was 10, 9, and 2 in eclampsia, PE, and gestational hypertension groups, respectively, with overall rate of 16.9%. PE and eclampsia comprised 71.70% of HDP but contributed 90.5% of all perinatal deaths.

CONCLUSION

Preeclampsia-eclampsia is associated with increased risk of adverse perinatal outcomes as compared to gestational and CH, necessitating screening, vigilant antenatal care, timely intervention, and referral.

Molecular mechanism of interaction of Mycobacterium tuberculosis with host macrophages under high glucose conditions

Mycobacterium tuberculosis has the potential to escape various cellular defense mechanisms for its survival which include various oxidative stress responses, inhibition of phagosome-lysosomes fusion and alterations in cell death mechanisms of host macrophages that are crucial for its infectivity and dissemination. Diabetic patients are more susceptible to developing tuberculosis because of impairement of innate immunity and prevailing higher glucose levels. Our earlier observations have demonstrated alterations in the protein profile of M. tuberculosis exposed to concurrent high glucose and tuberculosis conditions suggesting a crosstalk between host and pathogen under high glucose conditions. Since high glucose environment plays crucial role in the interaction of mycobacterium with host macrophages which provide a niche for the survival of M. tuberculosis, it is important to understand various interactive mechanisms under such conditions. Initial phagocytosis and containment of M. tuberculosis by macrophages, mode of macrophage cell death, respiratory burst responses, Mycobacterium and lysosomal co-localization were studied in M. tuberculosis H37Rv infected cells in the presence of varied concentrations of glucose in order to mimic diabetes like conditions. It was observed that initial attachment, phagocytosis and later containment were less effective under high glucose conditions in comparison to normal glucose. Mycobacterium infected cells showed more necrosis than apoptosis as cell death mechanism during the course of infection under high glucose concentrations. Co-localization and respiratory burst assay also indicated evasion strategies adopted by M. tuberculosis under such conditions. This study by using THP1 macrophage model of tuberculosis and high glucose conditions showed immune evasion strategies adapted during co-pathogenesis of tuberculosis and diabetes.

POS1011 PREDICTORS OF ENDOTHELIAL DYSFUNCTION IN ANKYLOSING SPONDYLITIS

Background:

Cardiovascular (CV) disease is the leading cause of death in Ankylosing Spondylitis (AS). Chronic systemic inflammation driven endothelial dysfunction leading to accelerated atherosclerosis results in premature mortality. Endothelial dysfunction is potentially treatable hence a therapeutic target. Predictive biomarkers for endothelial dysfunction would allow tailoring therapy to the individual.

Objectives:

To assess the endothelial dysfunction in AS in context of markers of inflammation and oxidative stress in AS patients.

Methods:

Sub group–analysis of our previous studies of AS1-3 was carried out and 80 AS patients were compared with 40 healthy controls matched for age and sex that were also part of these studies.2,3 Such analysis had so far not been performed in this cohort. Patients with traditional CV risk factors had been excluded in these studies. Flow-mediated dilatation (FMD), as a measure of endothelial function, was assessed by AngioDefender (Everist Health, Ann Arbor, MI). Inflammatory measures included: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Disease Activity Score (ASDAS) in AS. We also assayed markers of inflammation, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), proinflammatory cytokines (interleukin [IL]-1, IL-6, and tumor necrosis factor [TNF]-α), and endothelial dysfunction, including lipids and nitrite and marker of oxidative stress, TBARS.

Results:

FMD was significantly lower in AS patients compared with controls [(5.80±0.35% vs. 9.09±0.35%, p≤0.05) reduced by approximately 36%] whereas serum nitrite, TBARS, total cholesterol and LDL levels were significantly higher in AS compared with controls (p≤0.05). Compared with controls, AS patients had significantly high BASDAI, ASDAS and increased concentrations of ESR, CRP, TNF-α, and IL-6. In AS, FMD inversely correlated with ASDAS, CRP (Figure 1A), TNF-α (Figure 1B), nitrite (Figure 1C) and TBARS (Figure 1) and positively correlated with HDL (p≤0.05).

Figure 1.

Correlation of FMD with CRP, TNF-α, Nitrite and TBARS

Conclusion:

In AS, FMD was impaired, indicating endothelial dysfunction. ASDAS, CRP, TNF-α, nitrite, and TBARS were independent predictors of FMD in AS. AS-related inflammatory mechanisms (TNF-α, IL-6) and markers of vascular function and oxidative stress (CRP, nitrite and TBARS) may all be involved in the development of cardiovascular disease in AS and these predictors could serve as a novel therapeutic targets for preventing CV risk in AS.

References:

[1]Garg N, Krishan P, Syngle A. Rosuvastatin improves endothelial dysfunction in ankylosing spondylitis. Clin Rheumatol. 2015;34:1065-1071.

[2]Verma I, Syngle A, Krishan P, Garg N. Endothelial Progenitor Cells as a Marker of Endothelial Dysfunction and Atherosclerosis in Ankylosing Spondylitis. International Journal of Angiology. 2017;26:36–42.

[3]Verma I, Krishan P, Syngle A. Predictors of Atherosclerosis in Ankylosing Spondylitis. Rheumatol Ther. 2015;2(2): 173–182.

Disclosure of Interests:

None declared.

Comparison of performances of loop-mediated isothermal amplification, XPERT MTB/RIF and BACTEC MGIT in the diagnosis of childhood tuberculosis

AIM

Key to the successful management of paediatric pulmonary tuberculosis (PTB) lies in the early detection and proper treatment. We evaluated the performances of modern diagnostic tests: loop-mediated isothermal amplification (LAMP-IS6110), Xpert MTB/RIF (Cepheid) and mycobacteria growth indicator tube (BACTEC MGIT 960 culture) against a modified version of international consensus diagnostic definition (i.e. composite reference standard (CRS)).

METHODS

A cross-sectional analytical study was conducted in a tertiary care hospital in North India from July 2016 to December 2017 involving 100 children <14 years with suspected PTB. Respiratory specimens (sputum, gastric lavage and/or bronchoalveolar lavage) were collected and subjected to LAMP-IS6110, Xpert MTB/RIF and BACTEC MGIT 960 culture assay.

RESULTS

Fifty-five children had confirmed and probable TB according to the CRS (prevalence = 58.5%). The sensitivity of BACTEC MGIT 960 culture, Xpert MTB/RIF and LAMP-IS6110 assay was 14%, 9.1% and 10.91%, respectively, when compared against the predefined CRS. The specificity for all these tests was 100%. When compared with BACTEC MGIT 960 culture as the gold standard, the LAMP-IS6110 assay and Xpert MTB/RIF assay had the sensitivity of 85.71% (95% CI: 42.13-99.64%) and 71.43% (95% CI: 29.04-96.33%), respectively. The specificity of both assays was 100%.

CONCLUSIONS

We noted that LAMP-IS6110 performed better than Xpert MTB/RIF (Cepheid) in terms of sensitivity when compared against BACTEC MGIT 960 culture as reference standard, though specificity of both the tests was comparable. The diagnostic performance of BACTEC MGIT 960 culture was better than LAMP-IS6110 and Xpert MTB/RIF in paediatric PTB, when compared against CRS.

Differential diagnosis of disseminated Mycobacterium avium and Mycobacterium tuberculosis infection in HIV patients using duplex PCR

Background: Disseminated Mycobacterium avium complex (MAC) and Mycobacterium tuberculosis infections have almost similar clinical presentations but require different therapeutic management. Materials & methods: A duplex PCR was designed based on the sequence variation between the genes encoding catalase-peroxidase (KatG) of M. avium complex and M. tuberculosis, so as to discriminate MAC, M. tuberculosis and mixed mycobacterial (MAC + M. tuberculosis) infections in HIV patients. Results: An accurate, single-step differential diagnosis of disseminated mycobacterial infections in HIV patients was achieved with specific detection of a single band each for M. avium (120 bp) and M. tuberculosis (90 bp) and two bands for the mixed (120 and 90 bp) infections. Conclusion: katG gene-based duplex PCR can facilitate quick differential diagnosis of disseminated MAC and M. tuberculosis infections in HIV patients.

Proteomic profile of vitreous in patients with tubercular uveitis

OBJECTIVE

To elucidate disease-specific host protein profile in vitreous fluid of patients with intraocular inflammation due to tubercular uveitis (TBU).

METHODS

Vitreous samples from 13 patients with TBU (group A), 7 with non-TBU (group B) and 9 with no uveitis (group C) were analysed by shotgun proteomics using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). Differentially expressed proteins (DEPs) were subjected to pathway analysis using WEB-based Gene SeT Analysis Toolkit software.

RESULTS

Compared to control groups (B + C combined), group A (TBU) displayed 32 (11 upregulated, 21 downregulated) DEPs, which revealed an upregulation of coagulation cascades, complement and classic pathways, and downregulation of metabolism of carbohydrates, gluconeogenesis, glucose metabolism and glycolysis/gluconeogenesis pathways. When compared to group B (non-TBU) alone, TBU displayed 58 DEPs (21 upregulated, 37 downregulated), with an upregulation of apoptosis, KRAS signaling, diabetes pathways, classic pathways, and downregulation of MTORC1 signaling, glycolysis/gluconeogenesis, and glucose metabolism.

CONCLUSION

This differential protein profile provides novel insights into the molecular mechanisms of TBU and a baseline to explore vitreous biomarkers to differentiate TBU from non-TBU, warranting future studies to identify and validate them as a diagnostic tool in TBU. The enriched pathways generate interesting hypotheses and drive further research.

COVID-19 associated variations in liver function parameters: a retrospective study

BACKGROUND

Characteristics of laboratory findings of COVID-19 patients are of great significance for diagnosis and treatment. Studies that have analysed the variations in hepatic profile in correlation with the inflammatory markers in SARS-CoV-2 are limited.

METHODS

We retrospectively analysed liver function tests and inflammatory markers of 170 admitted patients with confirmed COVID-19 in the tertiary care centre, Post Graduate Institute of Medical Education and Research (PGIMER), India, using Roche Cobas Autoanalyzer.

RESULTS

Number of patients with normal liver enzyme levels were 63 (41.5%), while with raised levels of any of the liver enzymes were 89 (58.5%), out of which 43 (48.31%) had liver injury which manifested as increased severity in terms of intensive care unit (ICU) requirement (p=0.0005). Significantly raised levels of liver enzymes and liver injury were observed with age (p<0.0001) and in males (p=0.004). Significantly decreased levels of albumin and total proteins and increased levels of total bilirubin (p<0.0001) were seen in patients with abnormal liver enzyme levels and liver injury as compared to patients with normal levels. Significant increase in the levels of alanine transaminase and gamma-glutamyl transferase was seen on the 7th day, CRP and ferritin (p<0.0001) peaks were observed on 2nd and 3rd day respectively. A significant positive correlation was found between the levels of these inflammatory markers and liver function parameters.

CONCLUSIONS

More than half of patients admitted to the hospital with SARS-CoV-2 infection had an abnormal liver function which was found to be associated with raised levels of inflammatory markers. Significantly higher proportions of patients with abnormal liver function were elderly and males and were at higher risk of progressing to severe disease.

Proteomic profiling of peripheral blood mononuclear cells isolated from patients with tuberculosis and diabetes copathogenesis - A pilot study

Background

Diabetes is an important risk factor for developing tuberculosis. This association leads to exacerbation of tuberculosis symptoms and delayed treatment of both the diseases. Molecular mechanism and biomarkers/drug targets related to copathogenesis of tuberculosis and diabetes are still poorly understood. In this study, proteomics based 2D-MALDI/MS approach was employed to identify host signature proteins which are altered during copathogenesis of tuberculosis and diabetes.

Methods

Comparative proteome of human peripheral blood mononuclear cells (PBMCs) from healthy controls, tuberculosis and diabetes patients in comparison to comorbid diabetes and tuberculosis patients was analyzed. Gel based proteomics approach followed by in gel trypsin digestion and peptide identification by mass spectrometry was used for signature protein identification.

Results

Total of 18 protein spots with differential expression in tuberculosis and diabetes copathogenesis (TBDM) patients in comparison to other groups were identified. These proteins belonged to four functional categories i.e. structural, cell cycle/growth regulation, signaling and intermediary metabolism. These include Vimentin, tubulin beta chain protein, Actin related protein 2/3 complex subunit 2, coffilin 1 (Structural), PDZ LIM domain protein, Rho-GDP dissociation inhibitor, Ras related protein Rab (signaling), superoxide dismutase, dCTPpyrophosphatase 1, Transcription initiation factor TFIID subunit 12, three isoforms of Peptidylprolylcis-trans isomerase A, SH3 domain containing protein (metabolism), three isoforms of Protein S100A9 and S100A8 (cell cycle progression/growth regulation).

Conclusion

Proteins identified to be differentially expressed in TBDM patient can act as potent biomarkers and as predictors for copathogenesis of tuberculosis and diabetes.

Maternal hyperuricemia as a marker of post-spinal hypotension and uterine tone during cesarean delivery: a prospective observational study

PURPOSE

Raised serum uric acid, a marker of oxidative stress, is known to increase vascular tone and depress myometrial contractility. A rise in serum uric acid levels has also been reported during labor, warranting its correlation with post-spinal hypotension and uterine tone.

METHODS

Serum UA sample was drawn from enrolled healthy, laboring parturients. Of these, 100 women who required emergency cesarean delivery were re-sampled prior to surgery. Following spinal anesthesia we recorded episodes of hypotension (MAP < 80% of baseline), use of vasopressors and supplemental uterotonics. The primary outcome was maternal hyperuricemia (1SD > appropriate for gestation age) and its correlation with post-spinal hypotension. Secondary outcomes were total vasopressors used, duration of labor and its effect on uric acid levels, uterine tone and neonatal outcome.

RESULTS

Hyperuricemia was observed in 33% of parturients. On comparing with women showing normal uric acid levels, hyperuricemic parturients experienced significantly lower incidence of post-spinal hypotension (45.5% vs. 67.2%; p value = 0.04) and lower vasopressor usage (p value = 0.06). Clinically, an increased use of supplemental uterotonics in these parturients was noted (p = 0.20). The duration of labor had no impact on uric acid levels. Neonatal outcome was unaffected.

CONCLUSIONS

In healthy, normotensive parturients undergoing emergency cesarean delivery, maternal hyperuricemia is associated with lower incidence of post-spinal hypotension and reduced need of vasopressors. Elevated serum uric acid levels may also be associated with decreased uterine tone, necessitating greater requirement of supplemental uterotonics. However, further prospective trials are needed to strongly establish this association.

Transcriptional signatures of Mycobacterium tuberculosis in mouse model of intraocular tuberculosis

BACKGROUND

Studies on human intraocular tuberculosis (IOTB) are extremely challenging. For understanding the pathogenesis of IOTB, it is important to investigate the mycobacterial transcriptional changes in ocular environment.

METHODS

Mice were challenged intravenously with Mycobacterium tuberculosis H37Rv and at 45 days post-infection, experimental IOTB was confirmed based on bacteriological and molecular assays. M. tuberculosis transcriptome was analyzed in the infected eyes using microarray technology. The identified M. tuberculosis signature genes were further validated and investigated in human IOTB samples using real-time polymerase chain reaction.

RESULTS

Following intravenous challenge with M. tuberculosis, 45% (5/12) mice showed bacilli in the eyes with positivity for M. tuberculosis ribonucleic acid in 100% (12/12), thus confirming the paucibacillary nature of IOTB similar to human IOTB. M. tuberculosis transcriptome in these infected eyes showed significant upregulation of 12 M. tuberculosis genes and five of these transcripts (Rv0962c, Rv0984, Rv2612c, Rv0974c and Rv0971c) were also identified in human clinically confirmed cases of IOTB.

CONCLUSIONS

Differentially expressed mycobacterial genes identified in an intravenously challenged paucibacillary mouse IOTB model and presence of these transcripts in human IOTB samples highlight the possible role of these genes for survival of M. tuberculosis in the ocular environment, thus contributing to pathogenesis of IOTB.

Prevalence of Metabolic Syndrome in Rheumatoid Arthritis Patients: A Case Control Study from a Tertiary Care Centre in North India

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of mortality in patients with rheumatoid arthritis (RA). Along with traditional cardiovascular risk factors and systemic inflammation, metabolic syndrome (MetS) contributes to CVD and increased mortality in patients with RA. In this study we determine the prevalence of MetS in RA patients presenting to a tertiary care centre in north India.

METHODS

This is a case control study involving 114 patients of RA with disease duration of ≥1 year and 114 healthy controls who are age and sex matched. Components of MetS were assessed in all the subjects and disease activity of RA was determined by DAS28-ESR. MetS was defined according to modified ATP-III criteria and consensus definition of metabolic syndrome for adult Asian Indians.

RESULTS

Women constituted 81.6% in RA group and 80.5% in control group. Mean age of subjects was 44.81±12.7 years in RA group and 43.27±12.6 years in control group. According to modified ATP-III criteria, 36 (31.6%) RA subjects and 17 (14.9%) controls had MetS (p=0.03). According to the consensus definition of metabolic syndrome for adult Asian Indian criteria, 40 (35.1%) RA subjects and 18 (15.8%) controls had MetS (P=0.01). There was no significant difference in disease activity between subjects of RA with or without MetS (p=0.276).

CONCLUSION

The prevalence of MetS was higher in RA subjects compared to controls. There is no association of MetS with disease activity in our cohort. Larger studies are needed to determine the relation between MetS and disease activity.

Liquid Crystal based Detection of Pb(II) Ions Using Spinach RNA as Recognition Probe

We report a new method for label-free, sensitive, and facile detection of lead(II) ions (Pb²⁺) based on an aptamer-target binding event, which is recognized by orientations of liquid crystals (LCs) at aqueous interfaces. The LC film suspended in the aqueous phase demonstrated a homeotropic orientation in contact with a cationic surfactant cetyltrimethylammonium bromide (CTAB) due to self-assembly of CTAB molecules at the aqueous-LC interface. The ordering of LC subsequently changed to planar in the presence of the spinach RNA aptamer (SRNA) due to interactions between CTAB and SRNA. In the presence of the Pb²⁺ ion, the ordering of LC changed to homeotropic caused by reorganization of CTAB at the LC-aqueous interface. This is due to formation of more stable quadruplex structures of SRNA with Pb²⁺ ions in comparison to the CTAB-SRNA complex. The sensor exhibited a detection limit of 3 nM, which is well below the permissible limit of Pb²⁺ in drinking water. Our experiments establish that addition of Pb²⁺ leads to (i) the formation of Pb²⁺-SRNA complexes and (ii) a decrease in density of SRNA on the LC interface, but additional studies are required to determine which of these processes underlie the response of the LCs to the Pb²⁺. We have also demonstrated the potential application of the LC sensor for detection of Pb²⁺ in tap water. Unlike current laboratory-based heavy-metal-ion assays, this method is comparatively simple in terms of instrumentation, operation, and optical readout.

Exploiting chitosan and gold nanoparticles for antimycobacterial activity of in silico identified antimicrobial motif of human neutrophil peptide-1

The upsurge of drug resistant tuberculosis is major health threat globally. To counteract, antimicrobial peptides are being explored as possible alternatives. However, certain limitations of peptide-based drugs such as potential toxicity, high cost and relatively low stability need to be addressed to enhance their clinical applicability. Use of computer predicted short active motifs of AMPs along with nanotechnology could not only overcome the limitations of AMPs but also potentiate their antimicrobial activity. Therefore, present study was proposed to in silico identify short antimicrobial motif (Pep-H) of human neutrophil peptide-1 (HNP-1) and explore its antimycobacterial activity in free form and using nanoparticles-based delivery systems. Based on colony forming unit analysis, motif Pep-H led to killing of more than 90% M. tb in vitro at 10 μg/ml, whereas, similar activity against intracellularly growing M. tb was observed at 5 μg/ml only. Thereafter, chitosan (244 nm) and gold nanoparticles (20 nm) were prepared for Pep-H with both the formulations showing minimal effects on the viability of human monocyte derived macrophages (MDMs) and RBC integrity. The antimycobacterial activity of Pep-H against intracellular mycobacteria was enhanced in both the nanoformulations as evident by significant reduction in CFU (>90%) at 5-10 times lower concentrations than that observed for free Pep-H. Thus, Pep-H is an effective antimycobacterial motif of HNP-1 and its activity is further enhanced by chitosan and gold nanoformulations.

Expression analysis of genes associated with sucrose accumulation and its effect on source-sink relationship in high sucrose accumulating early maturing sugarcane variety

Sucrose synthesis/accumulation in sugarcane depends on the source-sink communication wherein source responds to sink demand for photoassimilate supply. Sucrose in stalk (sink) acts as signal, and sends feedback to restrain further synthesis of sucrose by regulating photosynthetic efficiency of leaves (source). Hence sucrose synthesis/accumulation is controlled by many genes and regulatory sequences including 3 invertases (SAI, CWI, NI), sucrose synthase (SuSy) and sucrose phosphate synthase (SPS). SPS and invertase play key role in enhancing sink strength which ultimately promotes greater sucrose accumulation in the sink tissues. In present study, a significant positive correlation was found between sucrose% of source and sink tissues which was greater in the top (R ² = 0.679) than middle (R ² = 0.580) and bottom (R ² = 0.518) internodes, depicting that sucrose accumulation in the stalk bears a direct relation with sucrose translocation efficiency from source. Results indicated an increased sucrose% with maturity, while reducing sugar content decreased with crop growth. qRT-PCR results exhibited an elevated expression of invertase in immature sink tissues depicting increased sink requirement, which declined with maturity. Similarly, increased PEP carboxylase gene expression as observed supported the fact that higher sink demand results in enhanced photosynthetic rate and thus influences the source activity. SPS was found active at initial stage of cane development indicating its role in sucrose synthesis. Thus by studying expression patterns of the different genes both, in source and sink tissues, a better understanding of the sucrose accumulation pathway in sugarcane is possible, which in turn can help in elucidating ways to enhance sucrose concentration in sink.

Transcriptional Profile of Mycobacterium tuberculosis in an in vitro Model of Intraocular Tuberculosis

Background: Intraocular tuberculosis (IOTB), an extrapulmonary manifestation of tuberculosis of the eye, has unique and varied clinical presentations with poorly understood pathogenesis. As it is a significant cause of inflammation and visual morbidity, particularly in TB endemic countries, it is essential to study the pathogenesis of IOTB. Clinical and histopathologic studies suggest the presence of Mycobacterium tuberculosis in retinal pigment epithelium (RPE) cells. Methods: A human retinal pigment epithelium (ARPE-19) cell line was infected with a virulent strain of M. tuberculosis (H37Rv). Electron microscopy and colony forming units (CFU) assay were performed to monitor the M. tuberculosis adherence, invasion, and intracellular replication, whereas confocal microscopy was done to study its intracellular fate in the RPE cells. To understand the pathogenesis, the transcriptional profile of M. tuberculosis in ARPE-19 cells was studied by whole genome microarray. Three upregulated M. tuberculosis transcripts were also examined in human IOTB vitreous samples. Results: Scanning electron micrographs of the infected ARPE-19 cells indicated adherence of bacilli, which were further observed to be internalized as monitored by transmission electron microscopy. The CFU assay showed that 22.7 and 8.4% of the initial inoculum of bacilli adhered and invaded the ARPE-19 cells, respectively, with an increase in fold CFU from 1 dpi (0.84) to 5dpi (6.58). The intracellular bacilli were co-localized with lysosomal-associated membrane protein-1 (LAMP-1) and LAMP-2 in ARPE-19 cells. The transcriptome study of intracellular bacilli showed that most of the upregulated transcripts correspond to the genes encoding the proteins involved in the processes such as adherence (e.g., Rv1759c and Rv1026), invasion (e.g., Rv1971 and Rv0169), virulence (e.g., Rv2844 and Rv0775), and intracellular survival (e.g., Rv1884c and Rv2450c) as well as regulators of various metabolic pathways. Two of the upregulated transcripts (Rv1971, Rv1230c) were also present in the vitreous samples of the IOTB patients. Conclusions:M. tuberculosis is phagocytosed by RPE cells and utilizes these cells for intracellular multiplication with the involvement of late endosomal/lysosomal compartments and alters its transcriptional profile plausibly for its intracellular adaptation and survival. The findings of the present study could be important to understanding the molecular pathogenesis of IOTB with a potential role in the development of diagnostics and therapeutics for IOTB.

Biochemical Profiling of Source and Sink Tissues at Different Growth Stages of Early and Late Maturing Varieties of Sugarcane (Saccharum spp. hybrids)

Sugarcane being C4 crop exhibits distinct source-sink signaling pathway that helps in storing remarkably high amount of sucrose in its sink tissues that makes it a highly remunerable crop worldwide. In the present study sugar content was profiled in both source and sink tissues of early (CoJ64) and late (BO91) maturing sugarcane varieties. At early growth stage (i.e. at 210 DAP) sink tissues of both varieties exhibited higher reducing sugar and low sucrose content while in source tissues both sucrose and reducing sugar content was observed high, depicted lower sink demand for sucrose. With maturity, when sink demand for sucrose storage increased, rise in sucrose content was seen in sink tissues, whereas in source tissues gradual decrease in sucrose and reducing sugar content was observed. Accumulation of sucrose was found much higher in CoJ64 than those in BO91. In CoJ64 maximum sucrose content (64.2%) was seen at 330 DAP while in BO91 it was 41.8% at 390 DAP. At this stage, source tissues too exhibited higher sucrose and reducing sugar content. Thus sucrose synthesis in source tissues and its transportation to the sink tissues is primarily governed by the sink demand.

Analysis of differential expression of protease-activated receptors in patients with allergic fungal rhinosinusitis

Background

Ever since its characterization in the 1970s, allergic fungal rhinosinusitis (AFRS) has been the subject of much controversy, especially regarding its pathogenesis. In this study, we analyzed the differential expression of genes that encode protease-activated receptors (PAR) in patients with AFRS and patients with chronic rhinosinusitis, and tried to understand the pathogenic basis of this disease.

Objective

To analyze the differential expression of PAR genes in patients with AFRS and in patients with chronic rhinosinusitis.

Methods

Mucosa from ethmoid sinuses of 51 patients (tests and controls) was biopsied and evaluated for messenger RNA expression of PAR genes by using reverse transcriptase–polymerase chain reaction. Each of the four PAR genes, i.e., par1, par2, par3 and par4 was amplified, the final gene products were run on 1.8% agarose gel and analyzed by densitometry to calculate differential expression. The significance level was determined as p ≤ 0.05.

Results

It was observed that the expressions of all four par genes were higher in the test samples compared with the controls, but statistical significance was achieved only for par1 (p=0.004) and par2 (p=0.05). Comparative expression of the four PAR genes was also performed within the test and control groups, and a statistically significant difference was seen between par1 and par2 (p=0.007), par1 and par3 (p=0.029), par1 and par4 (p=0.0001), par2 and par4 (p=0.002), and par3 and par4 (p=0.009) in the test group. In the control group as well, par1, par2, and par3 exhibited a higher expression compared with par4 but the difference was significant between par3 and par4 genes only.

Conclusion

Patients with AFRS expressed increased levels of PAR genes in their nasal mucosa, and, of the four PAR genes, a higher expression of par1, par2, and par3 was observed in both the groups compared with par4. This information contributes toward our understanding of pathogenesis and possibly treatment of AFRS.

Levels of circulating immune complexes containing Mycobacterium Tuberculosis-specific antigens in pulmonary tuberculosis and sarcoidosis patients

The present study was conducted to understand the aetiological link between tuberculosis (TB) and sarcoidosis. Sera from smear-positive TB subjects (n = 24), smear-negative TB subjects (n = 24), sarcoidosis patients (n = 24) and healthy controls (n = 24) were collected and circulating immune complexes were isolated. Sandwich ELISA was performed for detecting four highly specific mycobacterial regions of difference (RD) proteins (early secretory antigenic target 6 [ESAT6], 10 KDa culture filtrate protein [CFP10], 21 KDa CFP [CFP21] and mycobacterial protein from species TB [MPT 64]). Sensitivity and specificity was calculated, and receiver operating characteristic plots were plotted. Non-parametric Mann-Whitney U-test was used to calculate statistical significance. Seventy per cent of sarcoidosis patients showed the presence of immune complexes of mycobacterial RD proteins similar to that observed in the sera of smear-negative TB patients as opposed to antibody-based detection assay based on these RD proteins. Thus, immunoassays based on specific mycobacterial RD proteins also need to be developed and validated carefully to differentiate TB and sarcoidosis, a close mimic of smear-negative tuberculosis.

Poly(l-lysine)-Coated Liquid Crystal Droplets for Sensitive Detection of DNA and Their Applications in Controlled Release of Drug Molecules

Interactions between DNA and adsorbed poly(l-lysine) (PLL) on liquid crystal (LC) droplets were investigated using polarizing optical microcopy and epi-fluorescence microscopy. Earlier, we demonstrated that adsorption of PLL to the LC/aqueous interface resulted in homeotropic orientation of the LC and thus exhibited a radial configuration of the LC confined within the droplets. Subsequent adsorption of DNA (single-stranded DNA/double-stranded DNA) at PLL-coated LC droplets was found to trigger an LC reorientation within the droplets, leading to preradial/bipolar configuration of those droplets. To our surprise, subsequent exposure of complementary ssDNA to ssDNA/adsorbed PLL-modified LC droplets did not cause the LC reorientation. This is likely due to the formation of polyplexes (DNA-PLL complex) as confirmed by fluorescence microscopy and atomic force microscopy. In addition, dsDNA-adsorbed PLL droplets have been found to be effectively useful to displace (controlled release) propidium iodide (a model drug) encapsulated within dsDNA over time. These observations suggest the potential for a label-free droplet-based LC detection system that can respond to DNA and may provide a simple method to develop DNA-based drug nanocarriers.

Renal function after off-pump versus on-pump coronary artery bypass grafting

Background Renal dysfunction is a well-recognized major complication after coronary artery bypass grafting. Off-pump coronary artery bypass theoretically appears to have less impact on renal function. We estimated preoperative and postoperative creatinine clearance as a marker of renal dysfunction in patients undergoing off-pump and on-pump coronary artery bypass. Methods Thirty patients undergoing coronary artery bypass were randomly allocated to undergo either on-pump ( n = 15) or off-pump surgery ( n = 15). The two groups had similar preoperative demographic characteristics. Serum creatinine and creatinine clearance were measured for 4 days postoperatively and the results were compared with preoperative levels. Results The rise in serum creatinine on postoperative day 1 was 0.28 mgċdL^-1 in the on-pump group and 0.22 mgċdL^-1 in the off-pump group ( p = 0.27); on postoperative day 4 it was 0.15 mgċdL^-1 and 0.10 mgċdL^-1, respectively, ( p = 0.28). Similarly, the fall in creatinine clearance was 17.34 mLċmin^-1 in the on-pump group and 19.62 mLċmin^-1 in the off-pump group on postoperative day 1 ( p = 0.42), and 10.9 and 10.94 mLċmin^-1, respectively, on postoperative day 4 ( p = 0.64). Conclusion Renal function is not affected by the technique of coronary artery bypass surgery, whether with or without cardiopulmonary bypass, in spite of the theoretical advantage of off-pump surgery. Our study suggests that off-pump coronary artery bypass surgery does not confer significant protection from postoperative renal dysfunction in low-risk patients, when compared with on-pump surgery.

Transcriptome analysis of mycobacteria in sputum samples of pulmonary tuberculosis patients

Pulmonary tuberculosis, the disease caused by Mycobacterium tuberculosis, still retains a top rank among the deadliest communicable diseases. Sputum expectorated during the disease continues to be a primary diagnostic specimen and also serves as a reservoir of bacteria. The expression pattern of mycobacteria in sputum will lead to an insight into bacterial adaptation at the most highly transmissible stage of infection and can also help in identifying newer diagnostic as well as drug targets. Thus, in the present study, a whole genome microarray of Mycobacterium tuberculosis was used to elucidate the transcriptional profile of mycobacteria in the sputum samples of smear positive pulmonary tuberculosis patients. Overall, the mycobacteria in sputum appeared to be in a low energy and low replicative state as compared to in vitro grown log phase M. tb with downregulation of genes involved in ATP synthesis, aerobic respiration and translational machinery. Simultaneously, downregulation was also seen in the genes involved in secretion machinery of mycobacteria along with the downregulation of genes involved in the synthesis of phthiocerol dimycocerosate and phenol glycolipids. In contrast, the majority of the genes which showed an upregulation in sputum mycobacteria were of unknown function. Further identification of these genes may provide new insights into the mycobacterial behavior during this phase of infection and may help in deciphering candidates for development of better diagnostic and drug candidates.

Utility of adenosine deaminase (ADA), PCR & thoracoscopy in differentiating tuberculous & non-tuberculous pleural effusion complicating chronic kidney disease

Background & objectives:

Pleural effusion is a common occurrence in patients with late-stage chronic kidney disease (CKD). In developing countries, many effusions remain undiagnosed after pleural fluid analysis (PFA) and patients are empirically treated with antitubercular therapy. The aim of this study was to evaluate the role of adenosine deaminase (ADA), nucleic acid amplification tests (NAAT) and medical thoracoscopy in distinguishing tubercular and non-tubercular aetiologies in exudative pleural effusions complicating CKD.

Methods:

Consecutive stage 4 and 5 CKD patients with pleural effusions underwent PFA including ADA and PCR [65 kDa gene; multiplex (IS6110, protein antigen b, MPB64)]. Patients with exudative pleural effusion undiagnosed after PFA underwent medical thoracoscopy.

Results:

All 107 patients underwent thoracocentesis with 45 and 62 patients diagnosed as transudative and exudative pleural effusions, respectively. Twenty six of the 62 patients underwent medical thoracoscopy. Tuberculous pleurisy was diagnosed in six while uraemic pleuritis was diagnosed in 20 subjects. The sensitivity and specificity of pleural fluid ADA, 65 kDa gene PCR, and multiplex PCR were 66.7 and 90 per cent, 100 and 50 per cent, and 100 and 100 per cent, respectively. Thoracoscopy was associated with five complications in three patients.

Interpretation & conclusions:

Uraemia remains the most common cause of pleural effusion in CKD even in high TB prevalence country. Multiplex PCR and thoracoscopy are useful investigations in the diagnostic work-up of pleural effusions complicating CKD while the sensitivity and/or specificity of ADA and 65 kDa gene PCR is poor.

Expression analysis of genes associated with sucrose accumulation in sugarcane (Saccharum spp. hybrids) varieties differing in content and time of peak sucrose storage

Sucrose synthesis/accumulation in sugarcane is a complex process involving many genes and regulatory sequences that control biochemical events in source-sink tissues. Among these, sucrose synthase (SuSy), sucrose phosphate synthase (SPS), soluble acid (SAI) and cell wall (CWI) invertases are important. Expression of these enzymes was compared in an early (CoJ64) and late (BO91) maturing sugarcane variety using end-point and qRT-PCR. Quantitative RT-PCR at four crop stages revealed high CWI expression in upper internodes of CoJ64, which declined significantly in both top and bottom internodes with maturity. In BO91, CWI expression was high in top and bottom internodes and declined significantly only in top internodes as the crop matured. Overall, CWI expression was higher in CoJ64 than in BO91. During crop growth, there was no significant change in SPS expression in bottom internodes in CoJ64, whereas in BO91 it decreased significantly. Apart from a significant decrease in expression of SuSy in mature bottom internodes of BO91, there was no significant change. Similar SAI expression was observed with both end-point and RT-PCR, except for significantly increased expression in top internodes of CoJ64 with maturity. SAI, being a major sucrose hydrolysing enzyme, was also monitored with end-point PCR expression in internode tissues of CoJ64 and BO91, with higher expression of SAI in BO91 at early crop stages. Enzyme inhibitors, e.g. manganese chloride (Mn(++) ), significantly suppressed expression of SAI in both early- and late-maturing varieties. Present findings enhance understanding of critical sucrose metabolic gene expression in sugarcane varieties differing in content and time of peak sucrose storage. Thus, through employing these genes, improvement of sugarcane sucrose content is possible.