Magmas functions as a ROS regulator and provides cytoprotection against oxidative stress-mediated damages

Redox imbalance generates multiple cellular damages leading to oxidative stress-mediated pathological conditions such as neurodegenerative diseases and cancer progression. Therefore, maintenance of reactive oxygen species (ROS) homeostasis is most important that involves well-defined antioxidant machinery. In the present study, we have identified for the first time a component of mammalian protein translocation machinery Magmas to perform a critical ROS regulatory function. Magmas overexpression has been reported in highly metabolically active tissues and cancer cells that are prone to oxidative damage. We found that Magmas regulates cellular ROS levels by controlling its production as well as scavenging. Magmas promotes cellular tolerance toward oxidative stress by enhancing antioxidant enzyme activity, thus preventing induction of apoptosis and damage to cellular components. Magmas enhances the activity of electron transport chain (ETC) complexes, causing reduced ROS production. Our results suggest that J-like domain of Magmas is essential for maintenance of redox balance. The function of Magmas as a ROS sensor was found to be independent of its role in protein import. The unique ROS modulatory role of Magmas is highlighted by its ability to increase cell tolerance to oxidative stress even in yeast model organism. The cytoprotective capability of Magmas against oxidative damage makes it an important candidate for future investigation in therapeutics of oxidative stress-related diseases.

Mesoscale dynamic coupling of finite- and discrete-element methods for fluid-particle interactions

A new method for two-way fluid-particle coupling on an unstructured mesoscopically coarse mesh is presented. In this approach, we combine a (higher order) finite-element method (FEM) on the moving mesh for the fluid with a soft sphere discrete-element method for the particles. The novel feature of the proposed scheme is that the FEM mesh is a dynamic Delaunay triangulation based on the positions of the moving particles. Thus, the mesh can be multi-purpose: it provides (i) a framework for the discretization of the Navier-Stokes equations, (ii) a simple tool for detecting contacts between moving particles, (iii) a basis for coarse-graining or upscaling, and (iv) coupling with other physical fields (temperature, electromagnetic, etc.). This approach is suitable for a wide range of dilute and dense particulate flows, because the mesh resolution adapts with particle density in a given region. Two-way momentum exchange is implemented using semi-empirical drag laws akin to other popular approaches; for example, the discrete particle method, where a finite-volume solver on a coarser, fixed grid is used. We validate the methodology with several basic test cases, including single- and double-particle settling with analytical and empirical expectations, and flow through ordered and random porous media, when compared against finely resolved FEM simulations of flow through fixed arrays of particles.

Role of CYP2E1 genetic polymorphism in the development of oral leukoplakia among tobacco users in North Indian population

AIM

The aim of the study to find out role of CYP2E1 genetic polymorphism in development of oral leukoplakia among tobacco users in North Indian population, this study was carried out at Department of Oral and Maxillofacial Pathology, King George's Medical University, Lucknow, UP.

STUDY DESIGN

Study include a total of 105 leukoplakia patients were genotyped for CYP2E1 polymorphism (93 males and 12 females; mean age ± SD: 47.5 ± 10.6) and 96 unrelated healthy controls (85 males and 11 females; mean age ± SD: 49 ± 11.1). All the patients had either reported for treatment of leukoplakia or were diagnosed with leukoplakia during routine oral examination.

RESULTS

A total of 105 leukoplakia patients and 96 controls were included in the study. The mean age of leukoplakia patients and control were 47 ± 10 and 51 ± 10 years respectively. The exclusive smokers comprised 62 (59%) leukoplakia patients and 53 (53%) controls. The exclusive smokeless tobacco users were 16 (15%) in leukoplakia patients and 27 (28%) in controls groups, while 27 (26%) leukoplakia patients and 16 (17%) controls have both types (smoking as well as smoke less) of tobacco habits simultaneously. Range of life time smoking exposure in leukoplakia and controls were (5-80 PY in both groups) but the mean smoking exposure in both groups were (leukoplakia: 28 ± 21.8 PY, control: 27: ±17 PY). But the mean smokeless tobacco dose in two groups were (leukoplakia: 150 ± 175 CY, controls: 137 ± 110 CY).

CONCLUSION

All the results demonstrate an association between CYP2E1 genetic polymorphism and leukoplakia risk, premalignant lesion. It indicates that the CYP2E1 polymorphism, singly showed a protection towards the oral leukoplakia. Independent confirmation of this finding is required, and additional examination of the joint effect of CYP2E1genotype and other non-tobacco-related exposures is needed before more conclusive interpretation of our results can be made. This study demonstrates the importance of genetic variations in CYP2E1genes in susceptibility towards oral leukoplakia and it is conceivable that these variants will interact with environmental carcinogens and possibly some combinations of these genotypes will be at a high risk to oral leukoplakia.

Analysis of a potential cluster of rhinovirus infections in patients and staff on two haemato-oncology wards

BACKGROUND

Human rhinoviruses (HRV) cause the common cold, increased mortality in patients attending elderly care facilities and significant morbidity as well as mortality in the post-transplantation setting.

OBJECTIVES

The aim of the study was to determine if there had been a breakdown in infection control practice in a large haemato-oncology centre. Molecular techniques had detected increased numbers of HRV in respiratory samples from patients and staff over a 6-week period. Typing was performed to investigate the possibility of transmission between individuals.

STUDY DESIGN

This was a retrospective study having detected HRV RNA in combined nose and throat swab samples that were collected from 13 individuals: 8 patients and 5 staff members, in the haemato-oncology wards of a tertiary referral centre in January and February 2011. The 5'NTR and the VP4/VP2 region were used for HRV typing.

RESULTS

All 3 HRV species were detected with 7 HRV-A, 1 HRV-B, 4 HRV-C and 1 untyped. None of the individuals were infected by the same HRV serotype. Three individuals had multiple samples collected: 1 patient had an HRV-B infection over a 4-week period, 1 patient had an HRV-A infection over 3 months and 1 staff member had an HRV-C infection over 1 week, each shedding an unchanged serotype throughout the whole period.

CONCLUSION

Nucleotide sequence analysis confirmed that there was no breakdown in infection control measures. No transmission incidents had occurred between patients and/or between staff and patients.

ERG rearrangement and protein expression in the progression to castration-resistant prostate cancer

BACKGROUND

Approximately half of the prostate carcinomas are characterized by a chromosomal rearrangement fusing the androgen-regulated gene TMPRSS2 to the oncogenic ETS transcription factor ERG. Aim of this study was to comprehensively analyze the role and impact of the ERG rearrangement and protein expression on the progression to castration-resistant (CR) disease.

METHODS

We used a tissue microarray (TMA) constructed from 114 hormone naive (HN) and 117 CR PCs. We analyzed the ERG rearrangement status by fluorescence in situ hybridization and the expression profiles of ERG, androgen receptor (AR) and the proliferation marker Ki67 by immunohistochemistry.

RESULTS

Nearly half of the PC tissue specimens (HN: 38%, CR: 46%) harbored a TMPRSS2-ERG gene fusion. HN PCs with positive translocation status showed increased tumor cell proliferation (P<0.05). As expected, TMPRSS2-ERG gene fusion was strongly associated with increased ERG protein expression in HN and CR PCs (both P<0.0001). Remarkably, the study revealed a subgroup (26%) of CR PCs with ERG rearrangement but without any detectable ERG protein expression. This subgroup showed significantly lower levels of AR protein expression and androgen-regulated serum PSA (both P<0.05).

CONCLUSIONS

In this study, we identified a subgroup of ERG-rearranged CR PCs without detectable ERG protein expression. Our results suggest that this subgroup could represent CR PCs with a dispensed AR pathway. These tumors might represent a thus far unrecognized subset of patients with AR-independent CR PC who may not benefit from conventional therapy directed against the AR pathway.

HPTLC-densitometric determination and kinetic studies on antioxidant potential of monomeric phenolic acids (MPAs) from Bergenia species

We developed a HPTLC method for the quantification of vanillic acid, syringic acid, gallic acid and protocatechuic acid and kinetic studies on antioxidant potential in Bergenia ciliata and Bergenia stracheyi.

Identification of redox-regulated components of arsenate (AsV) tolerance through thiourea supplementation in rice

In this work, the effect of the interaction between As and thiourea was utilized for the identification of redox regulatory mechanisms of As tolerance in rice.

Hepatitis B vaccination with or without hepatitis B immunoglobulin at birth to babies born of HBsAg-positive mothers prevents overt HBV transmission but may not prevent occult HBV infection in babies: a randomized controlled trial

Vertical transmission of Hepatitis B virus HBV can result in a state of chronic HBV infection and its complications. HBV vaccination with or without hepatitis B immunoglobulin (HBIG) prevents transmission of overt infection to the babies. However, whether it also prevents occult HBV infection in babies is not known. Consecutive pregnant women of any gestation found to be HBsAg positive were followed till delivery, and their babies were included in the study. Immediately after delivery, babies were randomized to receive either HBIG or placebo in addition to recombinant HBV vaccine (at 0, 6, 10 and 14 weeks). The primary end-point of the study, assessed at 18 weeks of age, was remaining free of any HBV infection (either overt or occult) plus the development of adequate immune response to vaccine. The babies were further followed up for a median of 2 years of age to determine their eventual outcome. Risk factors for HBV transmission and for poor immune response in babies were studied. Of the 283 eligible babies, 259 were included in the trial and randomized to receive either HBIG (n=128) or placebo (n=131) in addition to recombinant HBV vaccine. Of the 222 of 259 (86%) babies who completed 18 weeks of follow-up, only 62/222 (28%) reached primary end-point. Of the remaining, 6/222 (3%) developed overt HBV infection, 142/222 (64%) developed occult HBV infection, and 12/222 (5%) had no HBV infection but had poor immune response. All 6 overt infections occurred in the placebo group (P=0.030), while occult HBV infections were more common in the HBIG group (76/106 [72%] vs. 66/116 [57%]; P=0.025). This may be due to the immune pressure of HBIG. There was no significant difference between the two groups in frequency of babies developing poor immune response or those achieving primary end-point. The final outcome of these babies at 24 months of age was as follows: overt HBV infection 4%, occult HBV infection 42%, no HBV infection but poor immune response 8% and no HBV infection with good immune response 28%. Women who were anti-HBe positive were a low-risk group, and their babies were most likely to remain free of HBV infection (occult or overt) and had good immune response to the vaccine. Maternal HBeAg-positive status and negativity for anti-HBe predicted not only overt but also any infection (both overt and occult) in babies. In addition, high maternal HBV DNA and treatment with vaccine alone were significant factors for overt HBV infection in babies. The current practice of administration of vaccine with HBIG at birth to babies born of HBsAg-positive mothers is not effective in preventing occult HBV infection in babies, which may be up to 40%. Because the most important risk factors for mother-to-baby transmission of HBV infection are the replicative status and high HBV DNA level in mothers; it will be worthwhile investigating the role of antivirals and HBIG administration during pregnancy to prevent mother-to-child transmission of HBV infection.

Analysis of carbapenem-resistant Acinetobacter from a tertiary care setting in North India

Multidrug-resistant (MDR) Acinetobacter baumannii is a worldwide concern as cause of serious nosocomial infections. We analysed 140 non-duplicate Acinetobacter sp. isolates from hospitalised patients in a tertiary care centre; 87% were MDR and 20% (28/140) meropenem resistant. Metallo-β-lactamase was produced by 16 of these, detected by ethylene-diamine-tetra-acetic acid disc synergy test. AmpC β-lactamase and efflux pump were present in 17 and 4 of the meropenem-resistant Acinetobacter, respectively. 9/16 MBL-positive isolates carried genes for carbapenem resistance as shown by polymerase chain reaction.

Antiinflammatory, Analgesic and Antipyretic Activities of Aerial Parts of Costus speciosus Koen

In the present study, methanol extracts of Costus speciosus Koen. aerial parts were assessed for antiinflammatory, analgesic and antipyretic activities in experimental animals. The antiinflammatory activity of methanol extract of Costus speciosus (400 and 800 mg/kg, p.o.) was evaluated using carrageenan-induced paw oedema test. Analgesic effect was evaluated using acetic acid-induced writhing and Eddy’s hot-plate models and antipyretic activity was assessed by Brewer’s yeast-induced pyrexia in rats. The methanol extract of aerial parts of Costus speciosus in a dose of 400 and 800 mg/kg showed significant antiinflammatory activity (19.36 and 40.05% reduction) at 5 h postmedication. In analgesic models extract treated animals at (400 and 800 mg/kg) inhibited writhing’s caused by acetic acid by 14.24 and 31.90%, respectively, and it also increased the latency period at both high and low doses which showed the mean reaction time at 16.60±0.355 s and 14.12±0.355 s, respectively, when compared to control in hot-plate test. It also reduces the rectal temperature of the animals at low and high doses significantly 37.03±0.108° and 36.63±0.098°, respectively, in Brewer’s yeast induced pyrexia. The obtained results of the present investigation revealed that methanol extract of Costus speciosus has significant antiinflammatory, analgesic and antipyretic activities.

Leishmania expressed lipophosphoglycan interacts with Toll-like receptor (TLR)-2 to decrease TLR-9 expression and reduce anti-leishmanial responses

Two different Toll-like receptors (TLRs) have been shown to play a role in host responses to Leishmania infection. TLR-2 is involved in parasite survival in macrophages upon activation by lipophosphoglycan (LPG), a virulence factor expressed by Leishmania. In contrast, activation of TLR-9 has been shown to promote a host-protective response. However, whether there is a relationship between the interaction of LPG and TLR-2, on one hand, with the effect of TLR-9, on the other hand, remains unknown. In this study, we report that in-vitro infection of macrophages with a L. major parasite with high expression levels of LPG results in decreased TLR-9 expression compared to infection with a L. major parasite with lower expression levels of LPG. Addition of anti-LPG as well as anti-TLR-2 antibodies prevents this reduction of TLR-9 expression. Also, the addition of purified LPG to macrophages results in a decrease of TLR-9 expression, which is shown to be mediated by transforming growth factor (TGF)-β and interleukin (IL)-10. Finally, in-vitro treatment of macrophages with anti-LPG and/or anti-TLR-2 antibodies before infection reduces the number of amastigotes in macrophages and co-treatment of mice with anti-TLR-2 antibodies and cytosine-phosphate-guanosine (CpG) reduces footpad swelling and parasite load in the draining lymph nodes, accompanied by an interferon (IFN)-γ-predominant T cell response. Thus, for the first time, we show how interactions between LPG and TLR-2 reduce anti-leishmanial responses via cytokine-mediated decrease of TLR-9 expression.