NtrC Increases Fitness of Salmonella enterica Serovar Typhimurium under Low and Fluctuating Nutrient Conditions.

Enteric pathogens cycle between nutrient-rich host and nutrient-poor external environment. These pathogens compete for nutrients while cycling between host and external environment, and often experience starvation. In this context, we have studied the role of a global regulator (NtrC) of Salmonella Typhimurium. The ntrC knockout mutation caused extended lag phase (8 h) and slow growth in the minimal medium. In lag phase, the wild-type cells showed ~60-fold more expression of ntrC gene. Gene expression studies and biochemical assays showed that the extended lag phase and slow growth is due to slow metabolism, instead of nitrogen transport. Further, we observed that ntrC knockout mutation led extended lag phase and slow growth, made ΔntrC mutant unable to compete with wild-type S. Typhimurium in both static and fluctuating nutrient condition. In addition to this, ΔntrC knockout mutant was unable to survive long-term nitrogen starvation (150 days). The nutrient recycling assays and gene expression studies revealed that ntrC gene is essential for rapid recycling of nutrients from the dead cells. Moreover, in the absence of ntrC gene, magnesium limits the nutrient recycling efficiency of S. Typhimurium. Therefore, the ntrC gene, which is often studied with respect to nitrogen scavenging in a low nitrogen growing condition, is required even in the adequate supply of nitrogen to maintain optimal growth and fast exit from the lag phase. Hence, we conclude that, the ntrC expression is essential for competitive fitness of S. Typhimurium under the low and fluctuating nutrient condition. IMPORTANCE S. Typhimurium, both in host and external environment, faces enormous competition from other microorganisms. The competition may take place either in static or in fluctuating nutrient conditions. Thus, how S. Typhimurium survives under such overlapping stress conditions remained unclear. Therefore, using S. Typhimurium as model organism we report that a global regulator NtrC, found in enteric bacteria like Escherichia coli and Salmonella, activates the set of genes and operons involved in rapid adaptation and efficient nutrient recycling/scavenging. These properties enable cells to compete with other microbes under the characteristic feast-or-famine lifestyle of S. Typhimurium. Therefore, this work helps us to understand the starvation physiology of the enteric bacterial pathogen S. Typhimurium.

A comparative study of sedo-analgesic effect of dexmedetomidine and dexmedetomidine with ketamine in postoperative mechanically ventilated patients.

Background and Aims: To compare the sedoanalgesic effects of dexmedetomidine alone or with combination of ketamine. Material and Methods: After getting ethical approval and informed patient consent, 60 adult surgical patients, were randomly divided into two groups. Group KD (n = 30); received dexmedotomidine 0.5 µg/kg/h mixed with ketamine 0.5 µg/kg/h and Group DEX (n = 30); received dexmedotomidine at 0.5 mg/kg/h infusion only. In both the groups, study drugs were titrated (dexmedetomidine- 0.2-0.7 µg/kg/h and ketamine 0.2-0.7 mg/kg/h) to achieve target sedation. Hemodynamic variables, pain scores, sedation scores, and patient satisfaction were recorded. Qualitative and Quantitative data were analyzed with Pearson Chi-squared test and analysis of variance test, respectively. All analyses were done by using statistical package for social sciences (SPSS) version 16.0. Results: Pain scores were higher in group DEX than in group KD at 2 h and 4 h which was statistically significant (P < 0.05). At the end of 2 h, sedation scores were higher in group KD than in group DEX and was statistically significant (P < 0.05). Length of intensive care unit stay was almost comparable in both groups, and the time to tracheal extubation was lesser in ketamine-dexmedetomidine group as compared to the dexmedetomidine alone group. However the difference was statistically non-significant. Conclusions: By combining dexmedetomidine with ketamine we observed lower incidence of hypotension and bradycardia. Dexmedetomidine with ketamine combination therapy could be used safely and effectively as sedo-analgesic agent.

Contribution of Indian researchers in high impact periodontal journals: a bibliometric analysis of last three years.

Bibliometric Analysis researches and analyses the quantitative data derived from scientific publications through the empirical evidence of scientific activity generated by collaborating authors through the final product of their research: the scientific article. In scientific society, the concept of impact factor is probably the most widely used in bibliometric construction. To assess the scientometrics of three high-impact factor periodontal journals and identify the contribution of India in these most productive journals over three years (Jan 2018 - Dec 2020) and to know the most influential topics researched. A retrospective observational study was conducted for the Journal of Clinical Periodontology, Journal of Periodontology, and Journal of Periodontal Research. All issues of 2018, 2019, and 2020 were electronically and hand searched for the following parameters: Number of papers, affiliated organizations, and countries, topics reported, and contribution of Indian authors. The data were organized and analyzed with descriptive statistics using SPSS software (version 21.0). In total 469 articles were published by Journal of Periodontology, followed by 454 articles in Journal of Clinical Periodontology and 287 articles in Journal of Periodontal Research. In all the three journals, China had the maximum contributions, succeeded by USA. India has published maximum number of articles in the Journal of Periodontal Research. When analysed, although less as compared to the western counterparts, an increasing trend in the publications is seen in case of India.

Monte Carlo simulation of enriched uranium in the lungs of thorax voxel phantom for assessment of enrichment and its effect on dose.

In-vivo lung monitoring is an important technique for the assessment of internal dose of radiation workers handling actinides. At BARC, counting efficiencies (CEs) of detection systems used for estimation of natural uranium in the lungs are evaluated using realistic thorax physical phantoms or computational voxel phantoms. The quantification of 238U and 235U in lungs is done using CEs determined at 63.3 keV and 185.7 keV photon energies respectively. These CEs can also be used for assessment of enriched uranium in the lungs of the workers. In this study, spectra are generated for HPGe array detectors using Monte Carlo simulations of various enriched uranium compositions distributed in the lungs of thorax voxel phantom. A methodology is developed to predict the 235U enrichment from lung spectrum analysis using the ratio of net counts in 185.7 keV and 63.3 keV energy regions. It is possible to estimate enrichments in the range of 2%-30% using the developed method with less than ±9% error. Finally, effect of 235U enrichment on dose assessment using lung monitoring method is studied.

Identification of Posttranslational Modifications of Endogenous Chromatin Proteins From Testicular Cells by Mass Spectrometry.

Chromatin architecture in mammalian spermatogenesis undergoes extensive structural and functional reorganization during which several testis-specific histone variants and other chromatin proteins are expressed in a stage-dependent manner. The most dramatic change in chromatin composition is observed during spermiogenesis where nucleosomal chromatin is transformed into nucleoprotamine fiber. Role of posttranslational modification (PTM) of somatic canonical histones and histone variants is well documented and effect several chromatin-templated events. PTM of testis-specific chromatin proteins is proposed to orchestrate chromatin-templated events during mammalian spermatogenesis and their identification and subsequent functional characterization is key to understand chromatin restructuring events and establishment of sperm epigenome. Here, we present protocols for the purification of endogenous testis chromatin proteins from different stages of spermatogenesis and identification of their PTM repertoire by mass spectrometry through examples of testis-specific histone variants (TH2B and HILS1), and transition proteins (TP1 and TP2).

In vitro macrophage activation: A technique for screening anti-inflammatory, immunomodulatory and anticancer activity of phytomolecules.

Macrophage activation plays a significant role in homeostasis of organisms. Various internal and external stress factors may affect their function, leading to adverse effects on the body. 'In vitro macrophage activation techniques provide us with a window to understand the mechanisms of inflammation and response of macrophages to the modulating interventions. Apart from infectious diseases, inflammation is also the major culprit in pathogenesis of many noncommunicable diseases such as arthritis, obesity, metabolic syndrome, diabetes, cancer, cardiovascular disease etc. In vitro macrophage activation allows us to study the role of polarized macrophages in the process of pathogenesis. This emerging technique leads to newer diagnostics, understanding pathophysiological mechanism/s, drug development and management of chronic inflammatory diseases. We, at MRC-KHS, use this technique for screening of medicinal plant-derived phytomolecules for their anti-inflammatory, immunomodulatory and anticancer activities. This review briefly outlines the different experimental models of in vitro macrophage activation and their applications for understanding the pathophysiological mechanisms of underlying chronic inflammation and screening of therapeutic activity of plant-based phytomolecules.

Plant Stress Responses Mediated by CBL-CIPK Phosphorylation Network.

At any given time and location, plants encounter a flood of environmental stimuli. Diverse signal transduction pathways sense these stimuli and generate a diverse array of responses. Calcium (Ca2+) is generated as a second messenger due to these stimuli and is responsible for transducing the signals downstream in the pathway. A large number of Ca2+ sensor-responder components are responsible for Ca2+ signaling in plants. The sensor-responder complexes calcineurin B-like protein (CBL) and CBL-interacting protein kinases (CIPKs) are pivotal players in Ca2+-mediated signaling. The CIPKs are the protein kinases and hence mediate signal transduction mainly by the process of protein phosphorylation. Elaborate studies conducted in Arabidopsis have shown the involvement of CBL-CIPK complexes in abiotic and biotic stresses, and nutrient deficiency. Additionally, studies in crop plants have also indicated their role in the similar responses. In this chapter, we review the current literature on the CBL and CIPK network, shedding light into the enzymatic property and mechanism of action of CBL-CIPK complexes. We also summarize various reports on the functional modulation of the downstream targets by the CBL-CIPK modules across all plant species.

Evaluation of Vacuum Assisted Closure Therapy for Soft Tissue Injury in Open Musculoskeletal Trauma.

INTRODUCTION: The application of controlled levels of negative or sub atmospheric pressure for a prolonged period of time on a wound had shown to accelerate removal of excess fluid and promote hyperaemia, which eventually promote wound healing. AIM: The study was conducted with the aim to evaluate the effectiveness of Vacuum Assisted Closure (VAC) therapy for soft tissue injury in open musculoskeletal trauma. MATERIALS AND METHODS: Twenty cases of complex musculoskeletal wound involving different parts of body were included in this progressive randomized study. In patients, aggressive debridement was done before the application of VAC therapy. Controlled negative pressure was uniformly applied to the wound. Dressings were changed after every 4 to 5 days. The evaluation of results included healing rate of the wound, eradication of infection, complication rate, and number of secondary procedures. RESULTS: VAC therapy over the wound was administered for an average of 20.4 days ±6.72 days (range 14 to 42 days). There was decrease in wound size attained by VAC therapy ranged from 2.6 to 24.4cm(2), with an average reduction of 10.55 cm(2). Three wounds were infected at the start of VAC therapy. However, all patients were cleared of bacterial infection by the end of VAC therapy. CONCLUSION: VAC therapy using negative pressure promote Wound healing by increasing local capillary perfusion and increased rate of granulation tissue formation, decreases the duration of wound healing and requires fewer painful dressing change.

TGF-ß signaling in liver and gastrointestinal cancers.

Transforming Growth Factor-ß (TGF-ß) plays crucial and complex roles in liver and gastrointestinal cancers. These include a multitude of distinct functions, such as maintaining stem cell homeostasis, promoting fibrosis, immune modulating, as a tumor suppressor and paradoxically, as a tumor progressor. However, key mechanisms for the switches responsible for these distinct actions are poorly understood, and remain a challenge. The Cancer Genome Atlas (TCGA) analyses and genetically engineered mouse models now provide an integrated approach to dissect these multifaceted and context-dependent driving roles of the TGF-ß pathway. In this review, we will discuss the molecular mechanisms of TGF-ß signaling, focusing on colorectal, gastric, pancreatic, and liver cancers. Novel drugs targeting the TGF-ß pathway have been developed over the last decade, and some have been proven effective in clinical trials. A better understanding of the TGF-ß pathway may improve our ability to target it, thus providing more tools to the armamentarium against these deadly cancers.

Beam extraction and high stability operation of high current electron cyclotron resonance proton ion source.

A high current electron cyclotron resonance proton ion source is designed and developed for the low energy high intensity proton accelerator at Bhabha Atomic Research Centre. The plasma discharge in the ion source is stabilized by minimizing the reflected microwave power using four stub auto tuner and magnetic field. The optimization of extraction geometry is performed using PBGUNS code by varying the aperture, shape, accelerating gap, and the potential on the electrodes. While operating the source, it was found that the two layered microwave window (6 mm quartz plate and 2 mm boron nitride plate) was damaged (a fine hole was drilled) by the back-streaming electrons after continuous operation of the source for 3 h at beam current of 20-40 mA. The microwave window was then shifted from the line of sight of the back-streaming electrons and located after the water-cooled H-plane bend. In this configuration the stable operation of the high current ion source for several hours is achieved. The ion beam is extracted from the source by biasing plasma electrode, puller electrode, and ground electrode to +10 to +50 kV, -2 to -4 kV, and 0 kV, respectively. The total ion beam current of 30-40 mA is recorded on Faraday cup at 40 keV of beam energy at 600-1000 W of microwave power, 800-1000 G axial magnetic field and (1.2-3.9) × 10(-3) mbar of neutral hydrogen gas pressure in the plasma chamber. The dependence of beam current on extraction voltage, microwave power, and gas pressure is investigated in the range of operation of the ion source.

Monte Carlo simulation of skull and knee voxel phantoms for the assessment of skeletal burden of low-energy photon emitters.

In case of internal contamination due to long-lived actinides by inhalation or injection pathway, a major portion of activity will be deposited in the skeleton and liver over a period of time. In this study, calibration factors (CFs) of Phoswich and an array of HPGe detectors are estimated using skull and knee voxel phantoms. These phantoms are generated from International Commission of Radiation Protection reference male voxel phantom. The phantoms as well as 20 cm diameter phoswich, having 1.2 cm thick NaI (Tl) primary and 5cm thick CsI (Tl) secondary detector and an array of three HPGe detectors (each of diameter of 7 cm and thickness of 2.5 cm) are incorporated in Monte Carlo code 'FLUKA'. Biokinetic models of Pu, Am, U and Th are solved using default parameters to identify different parts of the skeleton where activity will accumulate after an inhalation intake of 1 Bq. Accordingly, CFs are evaluated for the uniform source distribution in trabecular bone and bone marrow (TBBM), cortical bone (CB) as well as in both TBBM and CB regions for photon energies of 18, 60, 63, 74, 93, 185 and 238 keV describing sources of (239)Pu, (241)Am, (238)U, (235)U and (232)Th. The CFs are also evaluated for non-uniform distribution of activity in TBBM and CB regions. The variation in the CFs for source distributed in different regions of the bones is studied. The assessment of skeletal activity of actinides from skull and knee activity measurements is discussed along with the errors.

Neuroprotective Role of a Novel Copper Chelator against Aß 42 Induced Neurotoxicity.

Alzheimer's disease (AD) is a progressive neurodegenerative disease and associated with the extracellular deposits of amyloid- ß peptide in hippocampus region. Metal ions like Cu, Fe and Zn are known to associate with the amyloid beta (A ß ) at high concentration and interaction of these ions with soluble and aggregated forms of A ß peptide help in development of AD. Here we showed Cu mediated neurotoxicity in the eye tissues of transgenic Drosophila expressing human amyloid ß and its rescue through a novel Cu chelator. In this context, we have synthesised and characterized the compound L 2,6-Pyridinedicarboxylic acid, 2,6-bis[2-[(4-carboxyphenyl) methylene] hydrazide] by Mass spectra (MS) and Elemental analysis (EA). The Cu chelation potential of the compound L is tested in vivo in Drosophila. Oral administration of Copper to the transgenic larvae resulted in severe degeneration in eye tissues, which was rescued by the supplementation of compound L. The levels of anti-oxidant markers like SOD and MDA were measured in compound L treated flies and found a significant rescue (P < 0.001). Further rescue of the eye degeneration phenotypes as revealed by SEM affirm the role of copper in A ß toxicity. Hence, use of compound L, an amidoamine derivative, could be a possible therapeutic measure for A ß induced neurotoxicity.

Langmuir probe diagnostics of plasma in high current electron cyclotron resonance proton ion source.

A high current Electron Cyclotron Resonance (ECR) proton ion source has been developed for low energy high intensity proton accelerator at Bhabha Atomic Research Centre. Langmuir probe diagnostics of the plasma generated in this proton ion source is performed using Langmuir probe. The diagnostics of plasma in the ion source is important as it determines beam parameters of the ion source, i.e., beam current, emittance, and available species. The plasma parameter measurement in the ion source is performed in continuously working and pulsed mode using hydrogen as plasma generation gas. The measurement is performed in the ECR zone for operating pressure and microwave power range of 10(-4)-10(-3) mbar and 400-1000 W. An automated Langmuir probe diagnostics unit with data acquisition system is developed to measure these parameters. The diagnostics studies indicate that the plasma density and plasma electron temperature measured are in the range 5.6 × 10(10) cm(-3) to 3.8 × 10(11) cm(-3) and 4-14 eV, respectively. Using this plasma, ion beam current of tens of mA is extracted. The variations of plasma parameters with microwave power, gas pressure, and radial location of the probe have been studied.

Comparative clinical study of effect of neostigmine and ketamine for postoperative analgesia.

The purpose of the study was to evaluate and compare the role of neostigmine and ketamine as an additive to epidural bupivacaine to prolong the duration of postoperative analgesia. A double-blind randomised study was done on 60 adult patients, of both sexes, between 18 and 50 years, belonging to ASA grades I and II, undergoing below umbilical surgeries under epidural anaesthesia. All the patients were divided into three groups of 20 each to receive 20 ml of 0.5% bupivacaine with either 1 ml of normal saline, 100 mg of neostigmine or 50 mg of ketamine (both diluted with 1 ml normal saline). The mean (+/- SD) time to the first rescue analgesic administration was significantly prolonged by neostigmine [543.30 (+/- 133.40) minutes] and ketamine [292.00 (+/- 71.93) minutes] compared to the control group with saline [212.80 (+/- 62.49) minutes]. Postoperative 24-hour pain score was also less in neostigmine group. When compared to ketamine group neostigmine showed superior postoperative pain relief. Both neostigmine and ketamine demonstrated better haemodynamic stability with less incidence of hypotension. There was no increased incidence of nausea and vomiting or any other side-effects. In conclusion, it can be said neostigmine is a good adjuvant to epidural block to produce adequate pain relief without increased incidence of adverse effects.

TGF-ß1 signaling targets metastasis-associated protein 1, a new effector in epithelial cells.

In spite of a large number of transforming growth factor ß1 (TGF-ß1)-regulated genes, the nature of its targets with roles in transformation continues to be poorly understood. Here, we discovered that TGF-ß1 stimulates transcription of metastasis-associated protein 1 (MTA1), a dual master coregulator, in epithelial cells, and that MTA1 status is a determinant of TGF-ß1-induced epithelial-to-mesenchymal transition (EMT) phenotypes. In addition, we found that MTA1/polymerase II/activator protein-1 (AP-1) co-activator complex interacts with the FosB-gene chromatin and stimulates its transcription, and FosB in turn, utilizes FosB/histone deacetylase 2 complex to repress E-cadherin expression in TGF-ß1-stimulated mammary epithelial cells. These findings suggest that TGF-ß1 regulates the components of EMT via stimulating the expression of MTA1, which in turn, induces FosB to repress E-cadherin expression and thus, revealed an inherent function of MTA1 as a target and effector of TGF-ß1 signaling in epithelial cells.

The STAT3 inhibitor NSC 74859 is effective in hepatocellular cancers with disrupted TGF-beta signaling.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide, with few effective therapeutic options for advanced disease. At least 40% of HCCs are clonal, potentially arising from STAT3+, NANOG+ and OCT3/4+ liver progenitor/stem cell transformation, along with inactivation of transforming growth factor-beta (TGF-beta) signaling. Here we report significantly greater signal transducer and activator of transcription 3 (STAT3) and tyrosine phosphorylated STAT3 in human HCC tissues (P<0.0030 and P<0.0455, respectively) than in human normal liver. Further, in HCC cells with loss of response to TGF-beta, NSC 74859, a STAT3-specific inhibitor, markedly suppresses growth. In contrast, CD133(+) status did not affect the response to STAT3 inhibition: both CD133(+) Huh-7 cells and CD133(-) Huh-7 cells are equally sensitive to NSC 74859 treatment and STAT3 inhibition, with an IC(50) of 100 muM. Thus, the TGF-beta/beta2 spectrin (beta2SP) pathway may reflect a more functional 'stem/progenitor' state than CD133. Furthermore, NSC 74859 treatment of Huh-7 xenografts in nude mice significantly retarded tumor growth, with an effective dose of only 5 mg/kg. Moreover, NSC 74859 inhibited tyrosine phosphorylation of STAT3 in HCC cells in vivo. We conclude that inhibiting interleukin 6 (IL6)/STAT3 in HCCs with inactivation of the TGF-beta/beta2SP pathway is an effective approach in management of HCCs. Thus, IL6/STAT3, a major signaling pathway in HCC stem cell renewal and proliferation, can provide a novel approach to the treatment of specific HCCs.