Polydispersity-mediated high efficacy of an in-situ aqueous nanosuspension of PPEF.3HCl in methicillin resistant Staphylococcus aureus sepsis model.

Recently, World Health Organization declared antimicrobial resistance as the third greatest threat to human health. Absence of known cross-resistance, new class, new target, and a new mode of action are few major strategies being undertaken by researches to combat multidrug resistant pathogen. PPEF.3HCl, a bisbenzimidazole was developed as highly potent antibacterial agent against ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens, targeting topoisomerase IA. The present work encompasses a radical on-site generation of In-situ nanosuspension of PPEF.3HCl with enhanced efficacy against methicillin resistant S. aureus in septicemia model. We have generated instantaneously a PPEF.3HCl nanosuspension (IsPPEF.3HCl-NS) by mixing optimized monophasic PPEF.3HCl preconcentrate in propylene glycol into an aqueous medium comprising tween 80 as stabilizer. The IsPPEF.3HCl-NS showed precipitation efficiency of > 90 %, average particle size < 500 nm, retained upto 5 h, a negative zeta potential and bi/trimodal particle size distribution. Differential scanning calorimetry, X-ray diffraction confirmed partial amorphization and transmission electron microscopy revealed spherical particles. IsPPEF.3HCl-NS was non-hemolytic and exhibited good stability in serum. More significantly, it exhibited a âˆ¼ 1.6-fold increase in macrophage uptake compared to free PPEF.3HCl in the RAW 264.7 macrophage cell line. Confocal microscopy revealed accumulation of IsPPEF.3HCl-NS within the lysosomal compartment and cell cytosol, proposing high efficacy. In terms of antimicrobial efficacy, IsPPEF.3HCl-NS outperforms free PPEF.3HCl against clinical methicillin sensitive and resistant S. aureus strains. In a pivotal experiment, IsPPEF.3HCl-NS exhibited over 83 % survival at 8 mg/kg.bw and an impressive reduction of âˆ¼ 4-5 log-fold in bacterial load, primarily in the kidney, liver and spleen of septicemia mice. IsPPEF.3HCl-NS prepared by the In-situ approach, coupled with enhanced intramacrophage delivery and superior efficacy, positions IsPPEF.3HCl-NS as a pioneering and highly promising formulation in the battle against antimicrobial resistance.

Finding identical sequence repeats in multiple protein sequences: An algorithm.

In recent years, several experimental evidences suggest that amino acid repeats are closely linked to many disease conditions, as they have a significant role in evolution of disordered regions of the polypeptide segments. Even though many algorithms and databases were developed for such analysis, each algorithm has some caveats, like limitation on the number of amino acids within the repeat patterns and number of query protein sequences. To this end, in the present work, a new method called the internal sequence repeats across multiple protein sequences (ISRMPS) is proposed for the first time to identify identical repeats across multiple protein sequences. It also identifies distantly located repeat patterns in various protein sequences. Our method can be applied to study evolutionary relationships, epitope mapping, CRISPR-Cas sequencing methods, and other comparative analytical assessments of protein sequences.

Unraveling topoisomerase IA gate dynamics in presence of PPEF and its preclinical evaluation against multidrug-resistant pathogens.

Type IA topoisomerases maintain DNA topology by cleaving ssDNA and relaxing negative supercoils. The inhibition of its activity in bacteria prevents the relaxation of negative supercoils, which in turn impedes DNA metabolic processes leading to cell death. Using this hypothesis, two bisbenzimidazoles, PPEF and BPVF are synthesized, selectively inhibiting bacterial TopoIA and TopoIII. PPEF stabilizes the topoisomerase and topoisomerase-ssDNA complex, acts as an interfacial inhibitor. PPEF display high efficacy against ~455 multi-drug resistant gram positive and negative bacteria. To understand molecular mechanism of inhibition of TopoIA and PPEF, accelerated MD simulation is carried out, and results suggested that PPEF binds, stabilizes the closed conformation of TopoIA with -6Kcal/mol binding energy and destabilizes the binding of ssDNA. The TopoIA gate dynamics model can be used as a tool to screen TopoIA inhibitors as therapeutic candidates. PPEF and BPVF cause cellular filamentation and DNA fragmentation leading to bacterial cell death. PPEF and BPVF show potent efficacy against systemic and neutropenic mouse models harboring E. coli, VRSA, and MRSA infection without cellular toxicity.

Synthesis and Biological Evaluation of Novel 1H-Benzo[d]imidazole Derivatives as Potential Anticancer Agents Targeting Human Topoisomerase I.

Small molecules that modulate biological functions are targets of modern-day drug discovery efforts. A new series of novel 1H-benzo[d]imidazoles (BBZs) were designed and synthesized with different functional groups at the phenyl ring and variable lengths of the alkyl chain at the piperazine end as anticancer agents. We identified human topoisomerase I (Hu Topo I) as a probable target of these molecules through a computational study and DNA relaxation assay, a functional assay of the Hu Topo I enzyme. UV absorption, fluorescence, and circular dichroism spectroscopy were used to study interactions between BBZ and DNA. Out of 16 compounds, 11a, 12a, and 12b showed strong binding affinity and thermal stabilization of AT sequence-specific DNA. BBZs were screened against a panel of 60 human cancer cell lines at National Cancer Institute, USA. Most potent molecules 11a, 12a, and 12b showed 50% growth inhibition (GI50) in a concentration range from 0.16 to 3.6 µM cancer cells. Moreover, 12b showed 50% inhibition of the relaxation of DNA by Hu Topo I at 16 µM. Furthermore, flow cytometry revealed that 11a, 12a, and 12b cause prominent G2M arrest of cancer cells. In view of the above, we propose that 12b deserves to be further evaluated for its therapeutic use as an anticancer agent.

Pyrazoline analogs as potential anticancer agents and their apoptosis, molecular docking, MD simulation, DNA binding and antioxidant studies.

N-formyl pyrazoline derivatives (3a-3l) were designed and synthesized via Michael addition reaction through cyclization of chalcones with hydrazine hydrate in presence of formic acid. The structural elucidation of N-formyl pyrazoline derivatives was carried out by various spectroscopic techniques such as 1H, 13C NMR, FT-IR, UV-visible spectroscopy, mass spectrometry and elemental analysis. Anticancer activity of the pyrazoline derivatives (3a-3l) was evaluated against human lung cancer (A549), fibrosarcoma cell lines (HT1080) and human primary normal lung cells (HFL-1) by MTT assay. The results of anticancer activity showed that potent analogs 3b and 3d exhibited promising activity against A549 (IC50 = 12.47 ± 1.08 and 14.46 ± 2.76 µM) and HT1080 (IC50 = 11.40 ± 0.66 and 23.74 ± 13.30 µM) but low toxic against the HFL-1 (IC50 = 116.47 ± 43.38 and 152.36 ± 22.18 µM). The anticancer activity of potent derivatives (3b and 3d) against A549 cancer cell line was further confirmed by flow cytometry based approach. DNA binding interactions of the pyrazoline derivatives 3b and 3d have been carried out with calf thymus DNA (Ct-DNA) using absorption, fluorescence and viscosity measurements, circular dichroism and cyclic voltammetry. Antioxidant potential of N-formyl pyrazoline derivatives (3a-3l) has been also estimated through DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical and H2O2. Results revealed that all the compounds exhibited significant antioxidant activity. In silico molecular modelling and ADMET properties of pyrazoline derivatives were also studied using PyRx software against topoisomerase II receptor with PDB ID: 1ZXM to explore their best hits. MD simulation of 3b and 3d was also carried out with topoisomerase II for structure-function correlation in a protein. HuTopoII inhibitory activity of the analogs (3a-3l) was examined by relaxation assay at varying concentrations 100-1000 µM.

Resolución espontánea de un seudotumor inflamatorio del pulmón como consecuencia de una biopsia en cuña / Spontaneous Resolution of an Inflammatory Pseudotumour of the Lung Subsequent to Wedge Biopsy

La resolución completa y espontánea de un seudotumor inflamatorio (STI) de los pulmones es excepcional. Un hombre de 44 años de edad fue derivado para la valoración de una «neumonía no resuelta». Refería tos y expectoración mínima durante 5 meses, al igual que dolor torácico, hemoptisis y fiebre durante 2 semanas. La tomografía computarizada (TC) de tórax confirmó la presencia de una masa homogénea de bordes irregulares localizada en el lóbulo medio derecho con áreas de dispersión y broncograma aéreo. La biopsia pulmonar transbronquial era sugestiva de un «granuloma de células plasmáticas». En la toracotomía se puso de relieve una masa dura localizada en el lóbulo medio derecho y adherida al lóbulo inferior, la pared torácica y el mediastino, cuya resección no fue posible. Una biopsia en cuña confirmó un STI. La radiografía de tórax, efectuada 4 semanas después, reveló una resolución sustancial. En la TC de tórax, realizada un año más tarde, se demostró una escara fibrótica. Hasta la fecha solo se han publicado 6 casos de pacientes con una resolución espontánea de PTI de los pulmones, y en 4 se describió al cabo de 3 meses de una intervención diagnóstica cruenta(AU)

Spontaneous, complete resolution of inflammatory pseudotumour (IPT) of lungs is exceptionally rare. A 44-year-old male was referred for evaluation for «non resolving pneumonitis». He had cough and minimal expectoration for 5 months, chest pain, haemoptysis and fever for a fortnight. Computed tomography of thorax (CT-thorax) confirmed the presence of a homogenous mass with irregular borders in right middle lobe with areas of breakdown and air bronchogram. Transbronchial lung biopsy was suggestive of «plasma cell granuloma». Thoracotomy disclosed a hard mass in right middle lobe adherent to lower lobe, chest wall and mediastinum which could not be removed. A wedge biopsy confirmed IPT. Chest radiograph after 4 weeks revealed significant resolution. CT-thorax a year later showed fibrotic scar. Till date, there are only five reports documenting 6 patients with spontaneous resolution of IPT of lungs and in 4 this occurred within 3 months of an invasive diagnostic intervention(AU)

Spontaneous resolution of an inflammatory pseudotumour of the lung subsequent to wedge biopsy.

Spontaneous, complete resolution of inflammatory pseudotumour (IPT) of lungs is exceptionally rare. A 44-year-old male was referred for evaluation for «non resolving pneumonitis¼. He had cough and minimal expectoration for 5 months, chest pain, haemoptysis and fever for a fortnight. Computed tomography of thorax (CT-thorax) confirmed the presence of a homogenous mass with irregular borders in right middle lobe with areas of breakdown and air bronchogram. Transbronchial lung biopsy was suggestive of «plasma cell granuloma¼. Thoracotomy disclosed a hard mass in right middle lobe adherent to lower lobe, chest wall and mediastinum which could not be removed. A wedge biopsy confirmed IPT. Chest radiograph after 4 weeks revealed significant resolution. CT-thorax a year later showed fibrotic scar. Till date, there are only five reports documenting 6 patients with spontaneous resolution of IPT of lungs and in 4 this occurred within 3 months of an invasive diagnostic intervention.

Sensitization to Aspergillus antigens and occurrence of allergic bronchopulmonary aspergillosis in patients with asthma.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA), which is predominantly a disease of asthmatic subjects, is caused by hypersensitivity to Aspergillus antigens. Screening for Aspergillus sensitization in asthmatic subjects could identify those who are at risk for ABPA. Few studies have shown that fungal sensitization could be an important risk factor for asthma severity. We sought to determine the frequency of sensitization to Aspergillus antigens in asthmatic subjects and its effect on disease severity. We also determined the occurrence of ABPA in these subjects. DESIGN: Prospective study of consecutive patients with asthma. SETTING: Tertiary university referral hospital, outpatient department. PATIENTS AND METHODS: One hundred five asthmatic subjects and 26 volunteers underwent skin testing with aeroallergens, including Aspergillus, serum precipitins against Aspergillus antigens, and specific IgG against Aspergillus fumigatus, total serum IgE levels, and routine blood and radiologic investigations. ABPA was diagnosed when all eight major criteria were fulfilled. RESULTS: Thirty patients (28.5%) had a positive skin reactivity to Aspergillus antigens. Eleven patients (10.4%) had positive specific reactions to IgG, and 8 patients (7.6%) demonstrated positive reactions to serum precipitins. Eight of these 30 patients (26.6%) received diagnoses of ABPA, which was 7.6% of the total. None of the control subjects were sensitized to Aspergillus antigens. The patients were classified into the following four groups: negative skin test results; positive reactions to aeroallergens other than Aspergillus; positive reactions to aeroallergens including Aspergillus antigens; and patients with ABPA. Based on clinical and serologic parameters, patients with Aspergillus-sensitive asthma and ABPA had a significantly more severe form of the disease. CONCLUSIONS: Sensitization to the mold Aspergillus increases the severity of asthma. ABPA should be excluded in all patients with Aspergillus-sensitive asthma.

Multidrug resistant miliary tuberculosis and Pott's disease in an immunocompetent patient.

In a high tuberculosis TB prevalence country, mortality due to miliary TB is not unknown but the treatment outcome in general is good. We describe a previously healthy man with miliary TB who did not respond to 2-months antituberculous therapy with 4 drugs. Persistent complaints of backache, which antedated chest symptoms, resulted in a diagnosis of Pott's disease. Culture of bronchial aspirate yielded multidrug resistant Mycobacterium tuberculosis that responded slowly to streptomycin, ethionamide, cycloserine, clofazimine, ofloxacin, paraaminosalicylic acid and isoniazid. The association of multidrug resistant miliary TB with Pott's disease in an immunocompetent patient is yet to be highlighted.

Isoniazid associated, painful, bilateral gynaecomastia.

Gynaecomastia is a rarely reported adverse drug reaction due to isoniazid therapy. We describe a 25-year-old, human immunodeficiency virus (HIV)--negative man, who was started on antituberculosis treatment (ATT) with isoniazid (H), rifampicin (R), pyrazinamide (Z) and ethambutol (E) in the combination RHZE for the first two months and RH there on. After four months, while receiving RH, he developed painful bilateral gynaecomastia. ATT had to be stopped because of this adverse drug reaction. Gynaecomastia, however, persisted even after three months of cessation of therapy. A year later, the patient reported complete disappearance of pain and swelling, although right breast continued to appear larger than the left.