Attack on the scourge of tuberculosis: patented drug targets

Tuberculosis is one of the most devastating bacterial diseases, with increasing rates of morbidity and mortality, despite the presence of effective chemotherapy and Bacillus-Calmette-Guerin (BCG) vaccine. The success of Mycobacterium tuberculosis lies in its ability to spread by aerosol droplets, evade the host immune system and to persist in pulmonary granulomas. The advancement in the field of molecular and cellular microbiology and the availability of transcriptome and proteome data of M. tuberculosis have aided in understanding the pathogenesis of this organism for developing more effective drugs. The current strategy of drug design is to identify gene products, which are essential for survival and virulence. To date, several gene products of mycobacteria, ranging from proteins involved in cell wall synthesis to energy generation and from entry into host to persistence, have been shown to be essential for the survival or virulence of M. tuberculosis. These proteins and their associated pathways are considered as promising drug targets against M. tuberculosis and several of these have been patent protected. Herein, we enlist drug targets against M. tuberculosis for which patents have been filed and issued during the last ten years. The significance of these drug targets in the development of drug is also discussed. This review presents a comprehensive account of the pivotal information for drug discovery and drug design to all researchers involved in tuberculosis research

Root NRT, NiR, AMT, GS, GOGAT and GDH expression levels reveal NO andABA mediated drought tolerance in Brassica juncea L.

Little is known about the interactive effects of exogenous nitric oxide (NO) and abscisic acid (ABA) on nitrogen (N) metabolism and related changes at molecular and biochemical levels under drought stress. The present study highlights the independent and combined effect of NO and ABA (grouped as “nitrate agonists”) on expression profiles of representative key genes known to be involved in N-uptake and assimilation, together with proline metabolism, N–NO metabolism enzyme’s activity and nutrient content in polyethylene glycol (PEG) treated roots of Indian mustard (B. juncea cv. Varuna). Here we report that PEG mediated drought stress negatively inhibited growth performance, as manifested by reduced biomass (fresh and dry weight) production. Total N content and other nitrogenous compounds (NO3 − , NO2 − ) were decreased; however, NH4 + , NH4 + / NO3 − ratio and total free amino acids content were increased. These results were positively correlated with the PEG induced changes in expression of genes and enzymes involved in N-uptake and assimilation. Also, PEG supply lowered the content of macro- and micro-nutrients but proline level and the activity of ∆1 -pyrroline-5-carboxylate synthetase increased indicating increased oxidative stress. However, all these responses were reversed upon the exogenous application of nitrate agonists (PEG+NO, PEG+NO+ABA, and PEG+ABA) where NO containing nitrate agonist treatment i.e. PEG+NO was significantly more effective than PEG+ABA in alleviating drought stress. Further, increases in activities of L-arginine dependent NOS-like enzyme and S-nitrosoglutathione reductase were observed under nitrate agonist treatments. This indicates that the balanced endogenous change in NO and ABA levels together during synthesis and degradation of NO mitigated the oxidative stress in Indian mustard seedlings. Overall, our results reveal that NO independently or together with ABA may contribute to improved crop growth and productivity under drought stress

Root NRT, NiR, AMT, GS, GOGAT and GDH expression levels reveal NO andABA mediated drought tolerance in Brassica juncea L.

Little is known about the interactive effects of exogenous nitric oxide (NO) and abscisic acid (ABA) on nitrogen (N) metabolism and related changes at molecular and biochemical levels under drought stress. The present study highlights the independent and combined effect of NO and ABA (grouped as “nitrate agonists”) on expression profiles of representative key genes known to be involved in N-uptake and assimilation, together with proline metabolism, N–NO metabolism enzyme’s activity and nutrient content in polyethylene glycol (PEG) treated roots of Indian mustard (B. juncea cv. Varuna). Here we report that PEG mediated drought stress negatively inhibited growth performance, as manifested by reduced biomass (fresh and dry weight) production. Total N content and other nitrogenous compounds (NO3 − , NO2 − ) were decreased; however, NH4 + , NH4 + / NO3 − ratio and total free amino acids content were increased. These results were positively correlated with the PEG induced changes in expression of genes and enzymes involved in N-uptake and assimilation. Also, PEG supply lowered the content of macro- and micro-nutrients but proline level and the activity of ∆1 -pyrroline-5-carboxylate synthetase increased indicating increased oxidative stress. However, all these responses were reversed upon the exogenous application of nitrate agonists (PEG+NO, PEG+NO+ABA, and PEG+ABA) where NO containing nitrate agonist treatment i.e. PEG+NO was significantly more effective than PEG+ABA in alleviating drought stress. Further, increases in activities of L-arginine dependent NOS-like enzyme and S-nitrosoglutathione reductase were observed under nitrate agonist treatments. This indicates that the balanced endogenous change in NO and ABA levels together during synthesis and degradation of NO mitigated the oxidative stress in Indian mustard seedlings. Overall, our results reveal that NO independently or together with ABA may contribute to improved crop growth and productivity under drought stress

Phosphorylation of Mycobacterium tuberculosis Ser/Thr Phosphatase by PknA and PknB

Background: The integrated functions of 11 Ser/Thr protein kinases (STPKs) and one phosphatase manipulate the phosphorylation levels of critical proteins in mycobacterium tuberculosis. In this study, we show that the lone Ser/Thr phosphatase (PstP) is regulated through phosphorylation by STPKs. Principal Findings: PstP is phosphorylated by PknA and PknB and phosphorylation is influenced by the presence of Zn2+-ions and inorganic phosphate (Pi). PstP is differentially phosphorylated on the cytosolic domain with Thr137, Thr141, Thr174 and Thr290 being the target residues of PknB while Thr137 and Thr174 are phosphorylated by PknA. The Mn2+-ion binding residues Asp38 and Asp229 are critical for the optimal activity of PstP and substitution of these residues affects its phosphorylation status. Native PstP and its phosphatase deficient mutant PstPcD38G are phosphorylated by PknA and PknB in E. coli and addition of Zn2+/Pi in the culture conditions affect the phosphorylation level of PstP. Interestingly, the phosphorylated phosphatase is more active than its unphosphorylated equivalent. Conclusions and Significance: This study establishes the novel mechanisms for regulation of mycobacterial Ser/Thr phosphatase. The results indicate that STPKs and PstP may regulate the signaling through mutually dependent mechanisms. Consequently, PstP phosphorylation may play a critical role in regulating its own activity. Since, the equilibrium between phosphorylated and non-phosphorylated states of mycobacterial proteins is still unexplained, understanding the regulation of PstP may help in deciphering the signal transduction pathways mediated by STPKs and the reversibility of the phenomena

The role of gastric aspirates cytology and micro-erythrocyte sedimentation rate in predicting the early septicemia in newborn babies

Background: Sepsis is an important cause of neonatal morbidity and mortality. The magnitude of problem may be reduced by early detection of amniotic fluid infections and appropriate treatment of the neonate. Objective: The objective of this study was to know the role of gastric aspirates cytology and micro-erythrocyte sedimentation rate (m-ESR) in predicting the early-onset septicemia in newborn babies. Materials and Methods: The study was conducted on 100 neonates with suspected septicemia and 50 normal neonates admitted to neonatology section of a tertiary care hospital. Blood sample and gastric aspirate sample were collected for sepsis screening of the neonates. All the collected data were tabulated and statistically analyzed using SPSS 2.0 software. Results: About 55% of neonates had positive cytology and m-ESR and 22.2% had subsequent sepsis. Combined sensitivity was 50%, specificity was 81.25%, positive predictive value (PPV) was 62.5%, and negative predictive value (NPV) was 72.2%. Of the 45% of cases with positive cytology and micro-ESR, 13.3% had septicemia, 6.6% had pneumonia, and 2.2% had meningitis. The other 55% of cases had negative cytology and m-ESR, and out of them, 9.09% had septicemia, 7.2% had pneumonia, and 1.8% had meningitis. The sensitivity of m-ESR was 60%, specificity was 62.5%, PPV was 50%, and NPV was 71.5%. The combined sensitivity was 50%, specificity was 81.25%, PPV was 62.5%, and NPV was 72.2%. Conclusion: Combined gastric aspirate and m-ESR had high percentage of specificity and NPV. No specific and significant correlation between positive gastric aspirate cytology and rural/urban area, birth weight, sex, gestation, prolong labor, meconium-stained amniotic fluid, and mode of delivery was found

Assessment of phototherapy-induced hypocalcemia and its correlation with urinary calcium excretion in term and preterm newborns with neonatal hyperbilirubinemia: A cross-sectional study with controls

Introduction: Although hypocalcemia is often proposed to be associated with phototherapy in both term and preterm newborns, its exact incidence, clinical significance, and underlying mechanism still remain to be elucidated. Objective: The objective of this study was to determine the prevalence of hypocalcemia and its etiopathogenesis in terms of urinary calcium excretion. Methods: This study was carried out in a tertiary care center in North India with 50 neonates (29 term and 21 preterm) in the test group receiving single surface phototherapy. The other 50 age, sex, and gestational age-matched neonates were taken as controls who did not receive phototherapy. Serum calcium levels at 0 and 48 h and urinary calcium/creatinine ratio (mg/mg) at0 and 24 h of starting phototherapy were determined in both the groups and compared. Results: Total 12 preterm (57.1%) and 9 term newborns (31%) developed hypocalcemia after 48 h of phototherapy. The mean difference of serum ionized calcium between two groups was statistically significant at 48 h (4.58 mg/dl in the test group vs. 4.94 mg/dl in the control group, p<0.001). Percentage change in mean of urinary calcium/creatinine ratio at 24 h from baseline was 1.39% in the control group while it was 60.7% in the test group with statistically significant difference (p<0.001) between two groups. Only a weak negative correlation between serum ionized calcium and urinary calcium/creatinine ratio with correlation coefficient r=−0.316 could be established in the study among both term and preterm neonates. Conclusion: Both preterm and termneonates undergoing phototherapy are at increased risk for hypocalcemia and increased urinary calcium excretion. A universal recommendation regarding calcium supplementation in neonates undergoing phototherapy is yet to be established but seems like a reasonable intervention.&nbsp

Understanding the Role of PknJ in Mycobacterium tuberculosis: Biochemical Characterization and Identification of Novel Substrate Pyruvate Kinase A

Reversible protein phosphorylation is a prevalent signaling mechanism which modulates cellular metabolism in response to changing environmental conditions. In this study, we focus on previously uncharacterized Mycobacterium tuberculosis Ser/Thr protein kinase (STPK) PknJ, a putative transmembrane protein. PknJ is shown to possess autophosphorylation activity and is also found to be capable of carrying out phosphorylation on the artificial substrate myelin basic protein (MyBP). Previous studies have shown that the autophosphorylation activity of M. tuberculosis STPKs is dependent on the conserved residues in the activation loop. However, our results show that apart from the conventional conserved residues, additional residues in the activation loop may also play a crucial role in kinase activation. Further characterization of PknJ reveals that the kinase utilizes unusual ions (Ni2+, Co2+) as cofactors, thus hinting at a novel mechanism for PknJ activation. Additionally, as shown for other STPKs, we observe that PknJ possesses the capability to dimerize. In order to elucidate the signal transduction cascade emanating from PknJ, the M. tuberculosis membrane-associated protein fraction is treated with the active kinase and glycolytic enzyme Pyruvate kinase A (mtPykA) is identified as one of the potential substrates of PknJ. The phospholabel is found to be localized on serine and threonine residue(s), with Ser37 identified as one of the sites of phosphorylation. Since Pyk is known to catalyze the last step of glycolysis, our study shows that the fundamental pathways such as glycolysis can also be governed by STPK-mediated signaling

Root NRT, NiR, AMT, GS, GOGAT and GDH expression levels reveal NO andABA mediated drought tolerance in Brassica juncea L.

Little is known about the interactive effects of exogenous nitric oxide (NO) and abscisic acid (ABA) on nitrogen (N) metabolism and related changes at molecular and biochemical levels under drought stress. The present study highlights the independent and combined effect of NO and ABA (grouped as “nitrate agonists”) on expression profiles of representative key genes known to be involved in N-uptake and assimilation, together with proline metabolism, N–NO metabolism enzyme’s activity and nutrient content in polyethylene glycol (PEG) treated roots of Indian mustard (B. juncea cv. Varuna). Here we report that PEG mediated drought stress negatively inhibited growth performance, as manifested by reduced biomass (fresh and dry weight) production. Total N content and other nitrogenous compounds (NO3 − , NO2 − ) were decreased; however, NH4 + , NH4 + / NO3 − ratio and total free amino acids content were increased. These results were positively correlated with the PEG induced changes in expression of genes and enzymes involved in N-uptake and assimilation. Also, PEG supply lowered the content of macro- and micro-nutrients but proline level and the activity of ∆1 -pyrroline-5 carboxylate synthetase increased indicating increased oxidative stress. However, all these responses were reversed upon the exogenous application of nitrate agonists (PEG+NO, PEG+NO+ABA, and PEG+ABA) where NO containing nitrate agonist treatment i.e. PEG+NO was significantly more effective than PEG+ABA in alleviating drought stress. Further, increases in activities of L-arginine dependent NOS-like enzyme and S-nitrosoglutathione reductase were observed under nitrate agonist treatments. This indicates that the balanced endogenous change in NO and ABA levels together during synthesis and degradation of NO mitigated the oxidative stress in Indian mustard seedlings. Overall, our results reveal that NO independently or together with ABA may contribute to improved crop growth and productivity under drought stress

Оптимальні параметри зносу при терті ковзання для мінімального об'ємного зносу стоматологічних композитів на основі смол, наповнених кремнеземом

У дослідженні BisGMA та TEGDMA використовувались як мономери для виготовлення стоматологічних композитів. Камфорохінон застосовували для фотополімеризації з використанням світлодіодного фотополімеризатора. Для приготування стоматологічних композитів на основі наповнених смол використовували кремнезем з різними ваговими відсотками (5, 10, 15 та 20). Ненаповнені та наповнені зразки були підготовлені для випробувань на об'ємний знос. Щоб оцінити вплив вмісту наповнювача, нормального навантаження, швидкості ковзання та кількості циклів за допомогою ортогонального масиву L25, випробування на знос проводили з використанням різних параметрів процесу. Об'ємний знос проаналізовано за допомогою методології Taguchi та ANOVA. Було виявлено, що вміст наповнювача є найбільш значущим параметром, який впливає на об'ємний знос стоматологічних композитів, наповнених кремнеземом.In this study, BisGMA and TEGDMA as monomers were used to fabricate dental composites. Camphorquinone was used for photopolymerization using LED light curing unit. To prepare filled resin based dental composites, different wt. % (5, 10, 15, and 20) of nanosilica were used. Unfilled and filled samples were prepared to test for volumetric wear. To access the effect of filler content, normal load, sliding velocity and number of cycles using L25 orthogonal array, wear tests were performed on pin-on-disc apparatus using different levels of process parameters. Using Taguchi methodology and ANOVA, volumetric wear is analyzed, and it is revealed that the filler content is the most significant parameter which affects volumetric wear of nanosilica filled dental composites