Muhammad Atif Nisar

Molecular basis of arsenite (As +3 )-induced acute cytotoxicity in human cervical epithelial carcinoma cells

Background Rapid industrialization is discharging toxic heavy metals into the environment, disturbing human health in many ways and causing various neurologic, cardiovascular, and dermatologic abnormalities and certain types of cancer. The presence of arsenic in drinking water from different urban and rural areas of the major cities of Pakistan, for example, Lahore, Faisalabad, and Kasur, was found to be beyond the permissible limit of 10 parts per billion set by the World Health Organization. Therefore the present study was initiated to examine the effects of arsenite (As+3) on DNA biosynthesis and cell death. Methods After performing cytotoxic assays on a human epithelial carcinoma cell line, expression analysis was done by quantitative polymerase chain reaction, western blotting, and flow cytometry. Results We show that As+3 ions have a dose- and time-dependent cytotoxic effect through the activation of the caspase-dependent apoptotic pathway. In contrast to previous research, the present study was designed to explore the early cytotoxic effects produced in human cells during exposure to heavy dosage of As+3 (7.5 µg/ml). Even treatment for 1 h significantly increased the mRNA levels of p21 and p27 and caspases 3, 7, and 9. It was interesting that there was no change in the expression levels of p53, which plays an important role in G2/M phase cell cycle arrest. Conclusion Our results indicate that sudden exposure of cells to arsenite (As+3) resulted in cytotoxicity and mitochondrial-mediated apoptosis resulting from up-regulation of caspases.Background Rapid industrialization is discharging toxic heavy metals into the environment, disturbing human health in many ways and causing various neurologic, cardiovascular, and dermatologic abnormalities and certain types of cancer. The presence of arsenic in drinking water from different urban and rural areas of the major cities of Pakistan, for example, Lahore, Faisalabad, and Kasur, was found to be beyond the permissible limit of 10 parts per billion set by the World Health Organization. Therefore the present study was initiated to examine the effects of arsenite (As+3) on DNA biosynthesis and cell death. Methods After performing cytotoxic assays on a human epithelial carcinoma cell line, expression analysis was done by quantitative polymerase chain reaction, western blotting, and flow cytometry. Results We show that As+3 ions have a dose- and time-dependent cytotoxic effect through the activation of the caspase-dependent apoptotic pathway. In contrast to previous research, the present study was designed to explore the early cytotoxic effects produced in human cells during exposure to heavy dosage of As+3 (7.5 µg/ml). Even treatment for 1 h significantly increased the mRNA levels of p21 and p27 and caspases 3, 7, and 9. It was interesting that there was no change in the expression levels of p53, which plays an important role in G2/M phase cell cycle arrest. Conclusion Our results indicate that sudden exposure of cells to arsenite (As+3) resulted in cytotoxicity and mitochondrial-mediated apoptosis resulting from up-regulation of caspases.

Bacterial munch for infants: potential pediatric therapeutic interventions of probiotics

Probiotics are viable microorganisms with the capacity to alter the gastrointestinal microbiota of the host. The recent scientific advancements and development of probiotic formulations have rekindled the importance of these clinical interpretations, underlining the starring role of the gut flora in host metabolism, defense and immune regulation. Despite encouraging preliminary results from randomized clinical trials of probiotics for various clinical conditions including irritable bowel syndrome, necrotizing enterocolitis, gastroenteritis, antibiotic-associated diarrhea, infantile colic, and improvement of digestion and immune function, further evidence is needed to determine the reproducibility of the findings and elucidate the underlying mechanisms. In this review, we have considered the postnatal development of gut flora and appraised the role of probiotics in health and disease condition among infants.

In vitro and in vivo activity of Manuka honey against NDM-1-producing Klebsiella pneumoniae ST11

AIM To determine the therapeutic potential of Manuka honey against New Delhi metallo-β-lactamase-1-producing Klebsiella pneumoniae ST11 in vitro and in vivo. MATERIALS & METHODS Carbapenamases and metallo-β-lactamases-producing K. pneumoniae ST11 isolated from blood culture was confirmed by VITEK-2® system, matrix-assisted laser desorption ionization-time of flight and multilocus sequence typing, followed by determination of minimum inhibitory concentration (μg/ml) using VITEK-2 system. Genetic analysis of bla NDM-1 was done by PCR, pulsed-field gel electrophoresis and DNA hybridization. In vitro and in vivo efficacy of Manuka honey was performed by microbroth dilution assay and BALB/c mice model respectively. RESULTS K. pneumoniae ST11 displayed resistance to commonly used antibiotics. bla NDM-1 was located on 150 and 270kb plasmids. Minimum inhibitory concentration and minimum bactericidal concentration of Manuka honey was 30% (v/v) and substantial reduction of bacterial mean log value (>1 log) was observed in mice. Histological analysis of mice liver and kidneys demonstrated mild to moderate inflammation. CONCLUSION Manuka honey can be used as an alternate therapeutic approach for management of New Delhi metallo-β-lactamase-producing pathogens.

Immune escape strategies of Borrelia burgdorferi

The borrelial resurge demonstrates that Borrelia burgdorferi is a persistent health problem. This spirochete is responsible for a global public health concern called Lyme disease. B. burgdorferi faces diverse environmental conditions of its vector and host during its life cycle. To circumvent the host immune system is a prominent feature of B. burgdorferi. To date, numerous studies have reported on the various mechanisms used by this pathogen to evade the host defense mechanisms. This current review attempts to consolidate this information to describe the immunological and molecular methods used by B. burgdorferi for its survival.

Superantigens: procession of frets

uperantigens (Sags), a name devised by John Kappler in 1989 s a gang of about 40 microbial secretory proteins with a special orphology, sequence and ability to circumvent the orthodox echanism of antigen presentation and processing.1 Aberrant nd extreme T cell activation is the central property of these roteins. Various bacteria known to produce these menacing roteins include Staphylococcus, Streptococcus, Yersinia, Clostridum, and Mycoplasma. While some viruses like Epstein–Barr irus, Rabies virus, and HIV are also capable to produce Sags. ystemic intoxication due to Sags develops a fatal condiion known as toxic shock syndrome (TSS) which is basically aused by a cytokine tempest evolved by stimulated T cells. n general, Sags are virulence determinants which mark the daptive immune response via immune synapses.2 A variety of microbes produce toxins which vary in morhology and expression but they are known as Sags that ffirms the evolutionary trend of Sags production. Antigenic ariation due to allelic variation as observed for streptococcal itogenic exotoxin Z (SMEZ) is one of the obvious features and ffirms that host immune system directs the Sags evolution. here is a school of thought which holds the notion that prouction of Sags facilitates the transport of microbe inside the ost by corrupting the immune system. Interestingly, immune vasion elements like capsule and M protein are being reglated by the same genes which regulate the expression of ags.3 Well, another candid question is that how Sags thwart mmune elicitation against infection. Conceivably, the most robable phenomenon responsible for immune impediment s that Sags possess the skill to bring T-cell anergy into play. It eems likely that Sags steer the local IL2 deficit which results n stoppage of antigen-specific T cells expansion.3 Immunologically, Sags bind directly to major histocompatbility complex II (MHC-II) and T cell receptors (TCR) as intact roteins on binding sites other than conventional peptideinding sites. Binding sites for Sags on TCR are V (variable egion of beta chain) while on MHC-II they may bind to alpha hain or beta chain. Subsequently to the binding, Sags triger T-cell activation which ultimately steers the release of nflammatory mediators like TNF, IFN, and ILs. Sags are mainly ssociated with a dominated Th1 immune response. Morever, activated T cells are responsible for the staffing of B nd T cells to the infection site and co-activation of antigenresenting cells (APCs), results in the release of TNF and IL1 ts

Molecular basis of Cd +2 stress response in Candida tropicalis

This study examines the bioremediation potential and cadmium-induced cellular response on a molecular level in Candida tropicalis 3Aer. Spectroscopic analysis clearly illustrated the involvement of yeast cell wall components in biosorption. Cadmium bioaccumulation was confirmed by TEM, SEM, and EDX examination. TEM images revealed extracellular as well as cytoplasmic and vacuolar cadmium nanoparticle formation, further validated by presence of ycf1 gene and increased biosynthesis of GSH under cadmium stress. Fourteen proteins exhibited differential expression and during cellular redox homeostasis are found to involve in nitrogen metabolism, nucleotide biosynthesis, and carbohydrate catabolism. Interestingly, C. tropicalis 3Aer is equipped with nitrile hydratase enzyme, rarely been reported in yeast. It has the potential to remove nitriles from the environment. The Cd+2 toxicity not only caused growth stasis but also upregulated the cysteine biosynthesis, protein folding and cytoplasmic detoxification response elements. The present study suggests that C. tropicalis 3Aer is a potential candidate for bioremediating environmental pollution by Cd+2.

Occurrence and antibacterial susceptibility pattern of bacterial pathogens isolated from diarrheal patients in Pakistan

Objective: To determine the occurrence of bacterial pathogens responsible for diarrhea and to engender information regarding the effectiveness of commonly used antibiotic against diarrhea. Methods: This cross-sectional study was conducted between April and July 2014. Samples were collected from the Divisional Headquarter and Allied Hospital, Faisalabad, Pakistan. The differential and selective media were used to isolate bacterial pathogens, which were identified through cultural characteristics, microscopy, and biochemical tests. Disc diffusion assay was carried out using Muller Hinton agar medium, and minimum inhibitory concentration was determined using broth dilution method against isolated pathogens. Results: One hundred and forty-one (100%) samples were positive for some bacteria. Frequency of occurrence was Bacillus cereus (B. cereus) (66%), Escherichia coli (E. coli) (48.5%), Salmonella typhi (S. Typhi) (27.7%), Pseudomonas aeruginosa (P. aeruginosa) (8.5%), and Staphylococcus aureus (S. aureus) (4.3%). Single pathogen was detected in 20 (14.2%) samples whereas combinations were found in 121 (85.8%) samples. Bacillus cereus and E. coli were the most frequently detected pathogens followed by the S. Typhi, P. aeruginosa, and Staph. aureus. The percentage occurrence of isolated pathogens was 31% in B. cereus, 31% in E. coli, 18% in S. Typhi, 5% in P. aeruginosa, and 3% in Staph. aureus. Conclusion: Pseudomonas aeruginosa showed resistance against Amoxicillin and Cefotaxime, whereas S. aureus was found resistant against Cefotaxime. Statistical analysis using one way Analysis of Variance revealed that Ofloxacin and Gentamicin had significant (p<0.05) differences against all isolates as compared with other antibiotics used in this study.

Fungal-Derived Nanoparticles as Novel Antimicrobial and Anticancer Agents

In order to control microbial resistance against commonly used antibiotics, it is indispensable to develop novel and efficient antimicrobial agents. For this purpose, metallic nanoparticles (mainly inorganic) with their antimicrobial activites represent an effective solution for this global problem. However, synthesis of nanoparticles involves the use of expensive, poisonous and dangerous chemicals responsible for different biological and environmental hazards. This fact increases the necessity of developing environmentfriendly procedure by means of green synthesis (using plants) and extra-biological methods (using microbes such as bacteria and fungi). More recently, metallic nanoparticles, derived from fungal sources, have demonstrated their potential not only as a new-generation antimicrobial agents but also as anticancer agents. Therefore, this chapter is aimed to explore the various nanoparticles producing fungi with ultimate objective of elucidating the possible (i) mechanism of biosynthesis of metallic NPs by various fungi and (ii) mode of action of these mycosynthesized NPs on bacterial cell. This chapter would certainly increase our knowledge about interaction of nanoparticles with bacterial cell for their use in health biotechnology.