In Vitro and In Vivo Activity of Gepotidacin against Drug-Resistant Mycobacterial Infections.

Mycobacterial pathogens, including nontuberculous mycobacteria (NTM) and Mycobacterium tuberculosis, are pathogens of significant worldwide interest owing to their inherent drug resistance to a wide variety of FDA-approved drugs as well as causing a broad range of serious infections. Identifying new antibiotics active against mycobacterial pathogens is an urgent unmet need, especially those antibiotics that can bypass existing resistance mechanisms. In this study, we demonstrate that gepotidacin, a first-in-class triazaacenapthylene topoisomerase inhibitor, demonstrates potent activity against M. tuberculosis and M. fortuitum, as well as against other clinically relevant NTM species, including fluoroquinolone-resistant M. abscessus. Furthermore, gepotidacin exhibits concentration-dependent bactericidal activity against various mycobacterial pathogens, synergizes with several drugs utilized for their treatment, and reduces bacterial load in macrophages in intracellular killing assays comparably to amikacin. Additionally, M. fortuitum ATCC 6841 was unable to generate resistance to gepotidacin in vitro. When tested in a murine neutropenic M. fortuitum infection model, gepotidacin caused a significant reduction in bacterial load in various organs at a 10-fold lower concentration than amikacin. Taken together, these findings show that gepotidacin possesses a potentially new mechanism of action that enables it to escape existing resistance mechanisms. Thus, it can be projected as a potent novel lead for the treatment of mycobacterial infections, particularly for NTM, where present therapeutic interventions are extremely limited.

Phosphorus fractions in the sediment of a tropical reservoir, India: Implications for pollution source identification and eutrophication.

Eutrophication level in lakes and reservoirs depends on both internal and external phosphorus (P) load. Characterization of sediment P fractionation and identifying the P pollution sources are important for assessing the bio-availability of P and the dominant P source, for effectively controlling the water pollution. For determining the availability and sources of sediment P and eutrophication status, spatio-temporal variation in different P fractionation of sediment of hyper-eutrophic Krishnagiri reservoir, Tamil Nadu, India, was investigated. Sediment average total P (TP) content ranged from 4.62 to 5.64 g/kg. Main phosphorus form was the inorganic P (IP), and it makes up to 73.4-87.7% of TP. Among the different P fraction, viz. calcium bound (Ca-P), iron bound (Fe-P), aluminium bound (Al-P), exchangeable (Ex-P) and Organic-P (Org-P), Ca-P was the dominating fraction in both IP and TP. Trend of IP fraction was as follows: Ca-P > Fe-P > Al-P > Ex-P in pre-monsoon season, Fe-P > Ca-P > Al-P > Ex-P in monsoon and Ca-P > Al-P > Fe-P > Ex-P in post-monsoon. Overall the trend was as follows Ca-P > Fe-P > Al-P > Org-P > Ex-P. Bio-available-P (BAP) fractions ranged from 35.2 to 64.0% of TP, indicating its comparative higher value. Pearson's correlation matrix revealed that there was strong correlation among the different P fractions. Factor analysis indicates that different fractions of P were the dominating factor than the other sediment parameters. The observed variation in sediment P fractionation indicate the differences in source and characterization of P which is very helpful for implementation of effective management practices in controlling pollution that arises due to phosphorus in this hyper-eutrophic reservoir.

Plasmodium vivax liver stage assay platforms using Indian clinical isolates.

BACKGROUND: Vivax malaria is associated with significant morbidity and economic loss, and constitutes the bulk of malaria cases in large parts of Asia and South America as well as recent case reports in Africa. The widespread prevalence of vivax is a challenge to global malaria elimination programmes. Vivax malaria control is particularly challenged by existence of dormant liver stage forms that are difficult to treat and are responsible for multiple relapses, growing drug resistance to the asexual blood stages and host-genetic factors that preclude use of specific drugs like primaquine capable of targeting Plasmodium vivax liver stages. Despite an obligatory liver-stage in the Plasmodium life cycle, both the difficulty in obtaining P. vivax sporozoites and the limited availability of robust host cell models permissive to P. vivax infection are responsible for the limited knowledge of hypnozoite formation biology and relapse mechanisms, as well as the limited capability to do drug screening. Although India accounts for about half of vivax malaria cases world-wide, very little is known about the vivax liver stage forms in the context of Indian clinical isolates. METHODS: To address this, methods were established to obtain infective P. vivax sporozoites from an endemic region in India and multiple assay platforms set up to detect and characterize vivax liver stage forms. Different hepatoma cell lines, including the widely used HCO4 cells, primary human hepatocytes as well as hepatocytes obtained from iPSC's generated from vivax patients and healthy donors were tested for infectivity with P. vivax sporozoites. RESULTS: Both large and small forms of vivax liver stage are detected in these assays, although the infectivity obtained in these platforms are low. CONCLUSIONS: This study provides a proof of concept for detecting liver stage P. vivax and provide the first characterization of P. vivax liver stage forms from an endemic region in India.

Comparative study of the efficacy of gentamicin-coated intramedullary interlocking nail versus regular intramedullary interlocking nail in Gustilo type I and II open tibia fractures.

PURPOSE: Open tibia fracture is prone to infection, consequently causing significant morbidity and increasing the hospital stay, occupational loss and onset of chronic osteomyelitis. Intramedullary nailing is one choice for treating tibia shaft fractures. To improve the delivery of antibiotics at the tissue-implant interface, many methods have been proposed as a part of prophylaxis against infection. This study was conducted to study the role of gentamicin-impregnated intramedullary interlocking (IMIL) nail in the prevention of infection in Gustilo type I and II open tibia fractures and to compare the results with regular intramedullary nail. METHODS: The study included 28 patients with open tibia fractures (Gustilo type 1 or type 2); of them 14 underwent regular IMIL nailing and the other 14 were treated with gentamicin-coated nailing. Randomization was done by alternate allocation of the patients. Follow-up was done postoperatively (day 1), 1 week, 6 weeks, and 6 months for bone union, erythrocyte sedimentation rate (ESR), hemoglobin and C-reactive protein (CRP). Statistical significance was tested using unpaired t-test. A p value less than 0.05 was considered significant. RESULTS: There were 4 cases of infection in controls (regular IMIL nail) and no infection among patients treated with gentamicin-coated nail during the follow up (X2 = 4.66, p = 0.031). At 6 months postoperatively, CRP (p = 0.031), ESR (p = 0.046) and hemoglobin level (p = 0.016) showed significant difference between two groups. The bone healing rate was better with gentamicin-coated nail in comparison to regular IMIL nail at 6 months follow-up (p = 0.016). CONCLUSION: Gentamicin-coated IMIL nail has a positive role in preventing infection in Gustilo type I and II open tibia fractures.

The promise of image-guided brachytherapy of better clinical outcomes in treatment of cervical cancer: Does it deliver? An Indian scenario.

PURPOSE: The purpose of this series is to study the effectiveness of MRI based image-guided brachytherapy (IGBT) in Indian patients with cervical cancer who mostly present in later stages with bulky diseases. PATIENTS AND METHODS: 151 cervical cancer patients treated at our institution in last four years, with definitive chemoradiation followed by MRI-based brachytherapy were reviewed. With median follow up of 26 months, Kaplan Meier estimates at two years were calculated for local control (LC), pelvic control (PC), disease-free survival (DFS) and overall survival (OS). Also, severe late sequelae were reported. RESULTS: The patients predominantly presented with locally advanced cervical cancer in FIGO stages IIB (53.6%) and IIIB (23.2%). Tumour dimensions at diagnosis were ≥5 cm in 56.3% and pelvic nodal involvement was found in 38.4% of the patients. 94% of the patients received curative chemoradiation. Mean HRCTV volume at the time of brachytherapy was 42.2 ±â€¯19 cm3 and mean cumulative dose to HRCTV was 78.9 ±â€¯5.6 Gy. Overall LC, PC, DFS and OS at 2 years were 88.7%, 88.1%, 82.2% and 94% respectively. The predictors for local failure were FIGO stage (p = 0.002) and tumour size at diagnosis (p = 0.009). Late grade 3-4 bladder and bowel toxicities were observed in 3.8% of the patients. CONCLUSION: Our review demonstrates that IGBT is an effective strategy to improve locoregional control with limited long-term sequelae in patients with locally advanced extensive cervical cancer in the setting of a developing country.

Bactericidal activity and mechanism of action of AZD5847, a novel oxazolidinone for treatment of tuberculosis.

Treatment of tuberculosis (TB) is impaired by the long duration and complexity of therapy and the rising incidence of drug resistance. There is an urgent need for new agents with improved efficacy, safety, and compatibility with combination chemotherapies. Oxazolidinones offer a potential new class of TB drugs, and linezolid-the only currently approved oxazolidinone-has proven highly effective against extensively drug-resistant (XDR) TB in experimental trials. However, widespread use of linezolid is prohibited by its significant toxicities. AZD5847, a novel oxazolidinone, demonstrates improved in vitro bactericidal activity against both extracellular and intracellular M. tuberculosis compared to that of linezolid. Killing kinetics in broth media and in macrophages indicate that the rate and extent of kill obtained with AZD5847 are superior to those obtained with linezolid. Moreover, the efficacy of AZD5847 was additive when tested along with a variety of conventional TB agents, indicating that AZD5847 may function well in combination therapies. AZD5847 appears to function similarly to linezolid through impairment of the mycobacterial 50S ribosomal subunit. Future studies should be undertaken to further characterize the pharmacodynamics and pharmacokinetics of AZD5847 in both in vitro and animal models as well is in human clinical trials.

Development of chitosan conjugated DNA vaccine against nodavirus in Macrobrachium rosenbergii (De Man, 1879).

The protective efficacy of a DNA construct containing extra small virus antisense (XSVAS) gene of nodavirus encapsulated with chitosan nanoparticles (NPs) was investigated in giant freshwater prawn Macrobrachium rosenbergii (De Man, 1879). The delivery was carried out using oral and immersion methods. A plasmid concentration of 100 ng µL(-1) when conjugated with chitosan NPs was found to be more effective in increasing the survivability of the infected prawn. The particle mean size, zeta potential and loading efficiency percentage were 297 nm, 27 mV and 85%, respectively. The ability of the chitosan to form a complex with the plasmid was studied by agarose gel electrophoresis. The NPs were characterized by atomic force microscopy (AFM). Persistence study showed the presence of the DNA construct up to 30th day post-treatment. The oral treatment was found to be better than the immersion treatment for delivery of the chitosan-conjugated DNA construct. This is probably the first report on the delivery of nanoconjugated DNA construct in M. rosenbergii, against nodavirus.

The awareness and attitudes of students of one indian dental school toward information technology and its use to improve patient care.

BACKGROUND: Many obstacles need to be overcome if digital and electronic technologies are to be fully integrated in the operation of dental clinics in some countries. These obstacles may be physical, technical, or psychosocial barriers in the form of perceptions and attitudes related to software incompatibilities, patient privacy, and interference with the patient-practitioner relationship. The objectives of the study are to assess the perceptions of Indian dental students of one school toward the usefulness of digital technologies in improving dental practice; their willingness to use digital and electronic technologies; the perceived obstacles to the use of digital and electronic technologies in dental care setups; and their attitudes toward Internet privacy issues. METHODS: The study population consisted of 186 final year undergraduate dental students from the A. B. Shetty Memorial institute of Dental Sciences, Rajiv Gandhi University of Health Sciences, Mangalore, India. Survey data were analyzed descriptively . RESULTS: Most students indicated that information technology enhances patient satisfaction, the quality of dental record, diagnosis, treatment planning, and doctor-doctor communication. Cost of equipment and need for technical training were regarded as major obstacles by substantial proportions of respondents. DISCUSSION: Most dental students at our school feel that the information technology will support their decision making in diagnoses and devising effective treatment plans, which in turn increase patient satisfaction and quality of care. Students also perceived that lack of technical knowledge and the high cost of implementation are major barriers to developing information technology in India.

N'-[(E)-Furan-2-ylmethyl-idene]-4-hydroxy-benzohydrazide.

The title compound, C12H10N2O3, exists in the E conformation. The five-membered ring and the phenyl rings form dihedral angles of 36.73 (10) and 12.22 (10)°, respectively, with the central C(=O)N2C unit. The crystal packing is dominated by strong N-H⋯O and O-H⋯N hydrogen bonds. Together with weaker C-H⋯O inter-actions, these establish a three-dimensional supra-molecular network.

Homo-BacPROTAC-induced degradation of ClpC1 as a strategy against drug-resistant mycobacteria.

Antimicrobial resistance is a global health threat that requires the development of new treatment concepts. These should not only overcome existing resistance but be designed to slow down the emergence of new resistance mechanisms. Targeted protein degradation, whereby a drug redirects cellular proteolytic machinery towards degrading a specific target, is an emerging concept in drug discovery. We are extending this concept by developing proteolysis targeting chimeras active in bacteria (BacPROTACs) that bind to ClpC1, a component of the mycobacterial protein degradation machinery. The anti-Mycobacterium tuberculosis (Mtb) BacPROTACs are derived from cyclomarins which, when dimerized, generate compounds that recruit and degrade ClpC1. The resulting Homo-BacPROTACs reduce levels of endogenous ClpC1 in Mycobacterium smegmatis and display minimum inhibitory concentrations in the low micro- to nanomolar range in mycobacterial strains, including multiple drug-resistant Mtb isolates. The compounds also kill Mtb residing in macrophages. Thus, Homo-BacPROTACs that degrade ClpC1 represent a different strategy for targeting Mtb and overcoming drug resistance.

Synthesis and structure activity relationship of imidazo[1,2-a]pyridine-8-carboxamides as a novel antimycobacterial lead series.

Imidazo[1,2-a]pyridine-8-carboxamides as a novel antimycobacterial lead were generated by whole cell screening of a focused library against Mycobacterium tuberculosis. Herein, we describe the synthesis and structure activity relationship evaluation of this class of inhibitors and the optimization of physicochemical properties. These are selective inhibitors of Mycobacterium tuberculosis with no activity on either gram positive or gram negative pathogens.

4-{(E)-[2-(Pyridin-3-ylcarbon-yl)hydrazinyl-idene]meth-yl}phenyl acetate.

The title compound, C15H13N3O3, exists in the E conformation with respect to the azo-methane C=N double bond. The pyridyl and phenyl rings form dihedral angles of 35.67 (8) and 36.65 (7)°, respectively with the central C(=O)N2C unit. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds connect the mol-ecules into chains along the b axis. Another C-H⋯O inter-action connects mol-ecules along the c-axis direction, forming layers.

Carbinoxaminium dipicrate.

In the dication of the title salt, C16H21ClN2O(2+)·2C6H2N3O7 (-) [systematic name: 2-{(4-chloro-phen-yl)[2-(di-methyl-aza-nium-yl)eth-oxy]meth-yl}pyridinium bis-(2,4,6-tri-nitro-phenolate), contains a carbinoxaminium dication and two picrate anions, which are held together through inter-molecular N-H⋯O hydrogen bonds. In the dication, the two aromatic rings form a dihedral angle of 80.1 (1)°. In the two independent picrate anions, the nitro groups are twisted from the benzene plane, the largest dihedral angle in each ion being 42.8 (1) and 81.1 (5)°. In the crystal, in addition to the classical N-H⋯O hydrogen bonds, weak C-H⋯O hydrogen bonds and π-π inter-actions between the aromatic rings of the anions [centroid-centroid distances of 3.5768 (15) and 3.7436 (15) Å] help to establish the packing.

Oligodendroglia Confer Neuroprotection to NSC-34 Motor Neuronal Cells Against the Toxic Insults of Cerebrospinal Fluid from Sporadic Amyotrophic Lateral Sclerosis Patients.

Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disorder with multifactorial pathomechanisms affecting not only motor neurons but also glia. Both astrocytes and microglia get activated and contribute significantly to neurodegeneration. The role of oligodendroglia in such a situation remains obscure, especially in the sporadic form of ALS (SALS), which contributes to 90% of cases. Here, we have investigated the role of oligodendroglia in SALS pathophysiology using a human oligodendroglial cell line, MO3.13, by exposing the cells to cerebrospinal fluid from SALS patients (ALS-CSF; 10% v/v for 48 h). ALS-CSF significantly reduced the viability of MO3.13 cells and down-regulated the expression of oligodendroglia-specific proteins, namely, CNPase and Olig2. Furthermore, to investigate the effect of the observed oligodendroglial changes on motor neurons, NSC-34 motor neuronal cells were co-cultured/supplemented with conditioned/spent medium of MO3.13 cells upon exposure to ALS-CSF. Live cell imaging experiments revealed protection to NSC-34 cells against ALS-CSF toxicity upon co-culture with MO3.13 cells. This was evidenced by the absence of neuronal cytoplasmic vacuolation and beading of neurites, which instead resulted in better neuronal differentiation. Enhanced lactate levels and increased expression of its transporter, MCT-1, with sustained expression of trophic factors, namely, GDNF and BDNF, by MO3.13 cells hint towards metabolic and trophic support provided by the surviving oligodendroglia. Similar metabolic changes were seen in the lumbar spinal cord oligodendroglia of rat neonates intrathecally injected with ALS-CSF. The findings indicate that oligodendroglia are indeed rescuer to the degenerating motor neurons when the astrocytes and microglia turn topsy-turvy.

A cross-sectional study on clinical, demographic, microbiological, and radiological profile of bronchiectasis patients attending a tertiary care teaching center.

BACKGROUND: Bronchiectasis is a chronic pulmonary disease characterized by progressive and irreversible bronchial dilatation. The present study aimed to assess the clinical, demographic, microbiological, and radiological features of patients with bronchiectasis. METHODS: The study population included 60 subjects with bronchiectasis diagnosed by HRCT, who attended the Department of Respiratory Medicine a tertiary care teaching center. A single examiner examined all the 60 participants. Pulmonary function assessment was done on all the subjects on a spirometer, and early-morning sputum samples were taken for culture and sensitivity. Descriptive analysis was carried out by mean and standard deviation for quantitative variables, frequency, and proportion for categorical variables. Categorical outcomes were compared between study groups using the chi-square test. P value <0.05 was considered statistically significant. Co-Guide was used for statistical analysis. RESULT: The majority of the participants were males (62%). The most common sign observed was crepitations (75%). Pseudomonas aeruginosa (36%) was the primary pathogen isolated from sputum, followed by Klebsiella pneumonia (20%). Drug resistance was highest for ampicillin (56%), and imipenem (100%) was the most sensitive drug. CONCLUSION: Bronchiectasis is a heterogeneous entity with varied etiologies and multifarious clinic-radiological patterns. The information on etiology and the causative microorganism and antibiotic sensitivity and resistance aids in providing early treatment and thereby improving the lung function of affected individuals.

Synthesis of 2-mercaptobenzimidazole derivatives as potential anti-microbial and cytotoxic agents.

A series of novel 2-(1H-benzimidazol-2-ylsulfanyl)-N-(4-oxo-2-phenyl-thiazolidin-3yl)-acetamide 5a-j have been synthesized from various aldehydes and 2-(5-phenyl-[1,3,4]-oxadiazol-2-ylmethylsulfanyl)-1H-benzimidazole 6a-j from various benzoic acids. These compounds were screened for their in-vitro anti-bacterial activity against Staphylococcus aureus and Enterococcus faecalis as Gram positive, Klebsiella pneumoniae and Escherichia coli as Gram negative bacterial strains and for in-vitro anti-fungal activity against Asperigillus fumigatus and Candida albicans. The in vitro cytotoxic properties were studied using brine shrimp bioassay. Results revealed that, compounds 5b, 5d, 5g, 5i, 6b, 6e, 6f, and 6i showed excellent activity against a panel of microorganisms. The cytotoxic activities of 5b, 5g, 5i, 6b, 6f, 6h, and 6i were found to be good. All the newly synthesized compounds were characterized by elemental analysis, IR, (1)H-NMR, (13)C-NMR and MS.

Synthesis, in-vitro antimicrobial and cytotoxic studies of novel azetidinone derivatives.

Developing novel antimicrobial drugs is increasingly important in the modern pharmaceutical industry. A series of novel 3-chloro-4-[4-(2-oxo-2H-chromen-4-ylmethoxy)phenyl]-1-phenylazetidin-2-ones 5a-o have been synthesized from 4-bromomethylcoumarins 1a-e and 4-aryliminomethyl-phenols 3a-c. These compounds were screened for their in-vitro antibacterial activity against two Gram-positive (Staphylococcus aureus and Vancomycin resistant enteroccoccus) and two Gram-negative (Escherichia coli and Shigella dysentery) bacterial strains and antifungal activity against Aspergillus fumigatus, Candida albicans, and Penicillium. Results revealed that compounds 5c, 5f, 5h, 5j, and 5m showed excellent activity against a panel of microorganisms. The brine-shrimp bioassay was also carried out to study their in-vitro cytotoxic properties and two compounds, 5h and 5m, possessing LD(50) = 7.154x10(-4 )M and 5.782x10(-4) M, respectively, displayed potent cytotoxic activity against Artemia salina. The presence of a chlorine group in the coumarin moiety, its effect on their antibacterial, antifungal, and cytotoxic activities is discussed. All newly synthesized compounds were characterized by elemental analysis, IR, (1)H-NMR,( 13)C-NMR, and MS.

Molecular docking analysis of piperine with CDK2,CDK4,Cyclin D and Cyclin T proteins.

Piperine is a component of Piper nigrum (Black pepper). It is well known in ayurvedic formulations. Piperine is a bioenhancer as it reduces the activity of drug-metabolizing enzymes in rodents and thereby enhancing the plasma concentrations of several drugs, including the Pglycoprotein substrates. Therefore, it is of interest to understand the molecular docking interactions of piperine with several cell cycle proteins such as Cyclin dependent kinase 2 (CDK2), Cyclin-dependent kinase 4 (CDK4), Cyclin D and Cyclin T for further consideration in drug discovery related to oral cancer.

Immediate effects of Maitland mobilization versus Mulligan Mobilization with Movement in Osteoarthritis knee- A Randomized Crossover trial.

BACKGROUND: Maitland Mobilization or Mulligan Mobilization with Movement (MWM) approaches have been widely used clinically for pain relief and improving mobility in Osteoarthritis knee. However the experimental evidence supporting the usage of these mobilization techniques as sole interventions in management of Osteoarthritis knee is insufficient. OBJECTIVE: To determine from Maitland Mobilization and Mulligan MWM, which mobilization technique will be more effective in reducing pain and improving mobility and function in OA knee immediately after the intervention. STUDY DESIGN: Randomized Crossover trial. MATERIALS AND METHODS: 30 subjects with osteoarthritis knee were recruited and 15 each were randomly allocated to two intervention sequences-one sequence was where Maitland was given first followed by Mulligan and the other was where Mulligan was given first followed by Maitland with a washout period of 48 h in between the two interventions. Numeric Pain Rating Scale (NPRS), Timed Up and Go (TUG) test and Pain free Squat Angle were the outcome measures measured before and immediately after both interventions. RESULTS: Using Repeated Measures ANOVA for analysis of outcomes between and within interventions, no significant differences were seen between Maitland Mobilization and Mulligan MWM, for NPRS, TUG and Pain free Squat Angle (p = 0.18, p = 0.27,p = 0.17) respectively whereas within the interventions both Maitland and Mulligan all outcome measures showed significant changes (p < 0.001). CONCLUSION: Thus it can be seen that Maitland mobilization and Mulligan MWM, both are equally effective in osteoarthritis knee in reducing pain and improving functional mobility and pain free squat angle immediately post treatment.