Comparison of phenolic content and antioxidant activity of two common fruits of Bangladesh in solvents of varying polarities

Phenolic content and antioxidant activity of two common fruits of Bangladesh, namely Phyllunthus emblica and Elaeocarpus floribundus, were measured in water, methanol, ethanol, acetone and hexane extracts. Several in vitro models including phosphomolybdenum assay, DPPH free radical scavenging assay, FRAP assay and reducing power assay were used to assess the antioxidant activity of these extracts in comparison with reference antioxidants. Between the two fruits, P. emblica showed higher phenolic content and antioxidant activity in all the solvents used. In the DPPH scavenging assay, the activity of P. emblica extracts was close to reference antioxidants, ascorbic acid and BHT. Besides, considering the solvents used, extracts of both fruits had the highest phenolic and antioxidant activity in polar solvents. The correlation coefficient between total phenolics and antioxidant activities was found statistically significant. These findings suggest that P. emblica could be an excellent antioxidant resource for industries like food, pharmaceutical, and cosmetics.

Androgen deprivation-induced elevated nuclear SIRT1 promotes prostate tumor cell survival by reactivation of AR signaling

The NAD⁺-dependent deacetylase, Sirtuin 1 (SIRT1) is involved in prostate cancer pathogenesis. However, the actual contribution is unclear as some reports propose a protective role while others suggest it is harmful. We provide evidence for a contextual role for SIRT1 in prostate cancer. Our data show that (i) mice orthotopically implanted with SIRT1-silenced LNCaP cells produced smaller tumors; (ii) SIRT1 suppression mimicked AR inhibitory effects in hormone responsive LNCaP cells; and (iii) caused significant reduction in gene signatures associated with E2F and MYC targets in AR-null PC-3 and E2F and mTORC1 signaling in castrate-resistant ARv7 positive 22Rv1 cells. Our findings further show increased nuclear SIRT1 (nSIRT1) protein under androgen-depleted relative to androgen-replete conditions in prostate cancer cell lines. Silencing SIRT1 resulted in decreased recruitment of AR to PSA enhancer selectively under androgen-deprivation conditions. Prostate cancer outcome data show that patients with higher levels of nSIRT1 progress to advanced disease relative to patients with low nSIRT1 levels. Collectively, we demonstrate that lowering SIRT1 levels potentially provides new avenues to effectively prevent prostate cancer recurrence.

Leveraging Wettability Engineering to Develop Three-Layer DIY Face Masks From Low-Cost Materials

With the rapid spread of COVID-19 worldwide, the demand for appropriate face masks in the market has also skyrocketed. To ease strain on the supply of masks to the essential healthcare sector, it has become imperative that ordinary people rely more on home-made masks that can be easily put together using commonly available materials, while at the same time performing reasonably at arresting the ingress or egress of airborne droplets. Here, we propose a simple do-it-yourself (DIY) method for preparing a three-layered face mask that deploys two hydrophobic polypropylene nonwoven layers interspaced with a hydrophilic cellulosic cloth. The first hydrophobic layer, facing the user, allows high-momentum droplets (e.g., expelled by a sneeze or cough) to pass through and get absorbed in the next hydrophilic layer, thereby keeping the skin in contact with the mask dry and comfortable. The third (outermost) hydrophobic layer prevents penetration of the liquids from the middle layer to the outside, and also arrests any airborne droplets on its exterior. Simple tests show that our masks perform better in arresting the droplet transmission as compared to surgical masks available in the market.

Rationale, study design and methodology of the LANDMARC trial: a 3-year, pan-India, prospective, longitudinal study to assess management and real-world outcomes of diabetes mellitus

AIM

India contributes towards a large part of the worldwide epidemic of diabetes and its associated complications. However, there are limited longitudinal studies available in India to understand the occurrence of diabetes complications over time. This pan-India longitudinal study was initiated to assess the real-world outcomes of diabetes across the country.

METHODS

The LANDMARC study is the first prospective, multicentre, longitudinal, observational study investigating a large cohort of people with type 2 diabetes mellitus across India over a period of 3 years. The primary objective of this ongoing study is to determine the proportion of people developing macrovascular diabetes complications over the duration of the study (36 months ± 45 days) distributed over seven visits; the secondary objective is to evaluate microvascular diabetes complications, glycaemic control and time-to-treatment adaptation or intensification. Overall, 6300 participants (aged 25-60 years) diagnosed with type 2 diabetes for at least 2 years will be included from 450 centres across India. Data will be recorded for baseline demographics, comorbidities, glycaemic measurements, use of anti-hyperglycaemic medications and any cardiovascular or other diabetes-related events occurring during the observational study period.

CONCLUSIONS

The LANDMARC study is expected to reveal the trends in complications associated with diabetes, treatment strategies used by physicians, and correlation among treatment, control and complications of diabetes within the Indian context. The findings of this study will help to identify the disease burden, emergence of early-onset complications and dose titration patterns, and eventually develop person-centred care and facilitate public health agencies to invest appropriate resources in the management of diabetes. (Trial Registration No: CTRI/2017/05/008452).

Prompt diagnosis of Scedosporium apiospermum soft tissue infection: Life-saving in a renal transplant recipient

Scedosporium apiospermum, an ubiquitous filamentous fungus, a known cause of mycetoma, is emerging as an opportunistic pathogen in immunocompromised individuals. We report a case of painful foot abscess in a renal allograft recipient on immunosuppressive therapy, which was clinically diagnosed as a suppurative bacterial abscess. Pus was aspirated, which showed septate, branching hyphal elements and culture on Sabouraud's dextrose agar yielded S. apiospermum, which was identified based on its macroscopic and microscopic features. There are very few reports of scedosporiasis from India. High index of suspicion for unusual fungal infection helps in prompt etiological diagnosis in a transplant recipient and rapid management prevents further dissemination.

Heptachlor-induced epithelial to mesenchymal transition in HK-2 cells mediated via TGF-β1/Smad signalling

This study investigated the effect of heptachlor-induced oxidative stress (OS) on transforming growth factor (TGF)-β1-mediated epithelial to mesenchymal transition (EMT) in human renal proximal tubular epithelial (HK-2) cells. Following treatment of HK-2 cells with an increasing concentration of heptachlor (0.01–10 µM) for 24 h, the intracellular reactive oxygen species and malondialdehyde level increased, whereas the glutathione-s-hydroxylase (GSH) level declined significantly in a dose-dependent manner. Pretreatment with N-acetyl cysteine attenuates the heptachlor-induced OS. In this study, we have shown that heptachlor-induced OS regulates the mRNA expression of TGF-β1-mediated Smad signalling genes accompanied by increased nuclear localization of phosphorylated Smad-2 and phosphorylated Smad-3. Furthermore, the m-RNA and protein level of epithelial marker, that is, E-cadherin decreased while the mesenchymal marker, that is, α-smooth muscle actin increased in heptachlor exposed HK-2 cells. In conclusion, heptachlor-induced OS might be responsible for the activation of TGF-β1/Smad signalling which ultimately leads to renal damage by means of EMT.

Studies on the interaction of a synthetic nitro-flavone derivative with DNA: A multi-spectroscopic and molecular docking approach

Interaction of a ligand with DNA is often the basis of drug action of many molecules. Flavones are important in this regard as their structural features confer them the ability to bind to DNA. 2-(4-Nitrophenyl)-4H-chromen-4-one (4NCO) is an important biologically active synthetic flavone derivative. We are therefore interested in studying its interaction with DNA. Absorption spectroscopy studies included standard and reverse titration, effect of ionic strength on titration, determination of stoichiometry of binding and thermal denaturation. Spectrofluorimetry techniques included fluorimetric titration, quenching studies and fluorescence displacement assay. Assessment of relative viscosity and estimation of thermodynamic parameters from CD spectral studies were also undertaken. Furthermore, molecular docking analyses were also done with different short DNA sequences. The fluorescent flavone 4NCO reversibly interacted with DNA through partial intercalation as well as minor-groove binding. The binding constant and the number of binding sites were of the order 10⁴ M^-1 and 1 respectively. The binding stoichiometry with DNA was found to be 1:1. The nature of the interaction of 4NCO with DNA was hydrophobic in nature and the process of binding was spontaneous, endothermic and entropy-driven. The flavone also showed a preference for binding to GC rich sequences. The study presents a profile for structural and thermodynamic parameters, for the binding of 4NCO with DNA. DNA is an important target for ligands that are effective against cell proliferative disorders. In this regard, the molecule 4NCO is important since it can exert its biological activity through its DNA binding ability and can be a potential drug candidate.

Overexpression of outer membrane porins in E. coli using pBluescript-derived vectors

The genes coding for four major outer membrane porins of Escherichia coli, ompF, ompC, phoE, and lamB, have been cloned into pBluescript-derived vectors and overexpressed to very high level (approximately 80% of the total membrane protein) in widely used host strains lacking one or more porins. For OmpF, OmpC, and PhoE porins it is shown that, contrary to current dogma, the genes can be overexpressed without undue deleterious effects upon cell growth and are stable, even under conditions of continuous expression. In contrast, overexpression of LamB is toxic to cell growth, but can be performed using tightly regulated lac promotor-driven expression. The vectors described allow overexpression, sequencing, and mutagenesis to be performed using a single system, without the necessity of subcloning, thus simplifying genetic manipulation. A particular advantage of these new vectors (with the exception of the vector for LamB) is that they do not require a particular regime for inducing the recombinant protein. To our knowledge, this study is the only comparative study of widely used membrane porin expression systems and the first to show that several porins can be stably expressed individually and maintained on high copy number vectors.

Continuous flow microreactor for protein PEGylation

PEGylation is increasingly being utilized to enhance the therapeutic efficacy of biopharmaceuticals. Various chemistries and reaction conditions have been established to synthesize PEGylated proteins and more are being developed. Both the extent of conversion and selectivity of protein PEGylation are highly sensitive to process variables and parameters. Therefore, microfluidic-based high-throughput screening platforms would be highly suitable for optimization of protein PEGylation. As part of this study, a poly-dimethylsiloxane-based continuous flow microreactor system was designed and its performance was compared head-to-head with a batch reactor. The reactants within the microreactor were contacted by passive micromixing based on chaotic advection generated by staggered herringbone grooves embedded in serpentine microchannels. The microreactor system was provided with means for on-chip reaction quenching. Lysozyme was used as the model protein while methoxy-polyethylene glycol-(CH2)5COO-NHS was used as the PEGylation reagent. Full mixing was achieved close to the microreactor inlet, making the device suitable for protein PEGylation. The effect of mixing type, i.e., simple stirring versus chaotic laminar mixing on PEGylation, was investigated. Higher selectivity (as high as 100% selectivity) was obtained with the microreactor while the conversion was marginally lower.

Prediction of Un-erupted Canine and Premolar Tooth Size in Mixed Dentition among Bangladeshi Population

Accurate prediction of the space available to accommodate the size of the un-erupted canines and premolars plays an important role in mixed dentition in Orthodontics. This Descriptive cross sectional study was carried out in the Department of Orthodontics of Bangabandhu Sheikh Mujib Medical University from July 2014 to June 2015. Dental study models of 140 patients were taken as sample. The sample was consisted of 54 Bangladeshi males and 86 females aged between 12 to 17 years and without any previous orthodontic treatment fully erupted permanent teeth and with no dental anomalies were recruited. The study was done by measuring the mesio-distal dimensions of teeth over the dental cast. A pre-structured data collection form which includes the particulars of the patient and data was filled. All patients were having a serial number to maintain their confidentiality. The study protocol was approved by "Institutional Review Board" of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. Un-paired t test were used to examine differences between genders, correlation coefficients and linear regression equations were used to carry out the analysis. Descriptive statistics including means, standard deviations, and minimum-maximum values were calculated. Unpaired sample 't' tests were carried out to compare tooth size between the sexes. Logistic regression for development of new prediction formula on the basis of study sample of our population. Pearson correlation coefficient test for found the correlation between mandibular incisors and mandibular and maxillary canine and premolars in each quadrant. The difference between the present study with that of Moyers and Tanaka and Johnston were statistically significant (p<0.001). The values from Moyers and Tanaka and Johnston methods exceed while comparing to Bangladeshi population. Therefore, Moyers and Tanaka and Johnston method of prediction are not applicable for our population.

Isolation of flavonoids from apple peel using novel graphene oxide cotton fiber

A novel graphene oxide cotton fibre (GOF) was used to adsorb flavonoids from crude ethanol extracts derived from apple peels. Ultra-high pressure liquid chromatography-mass spectrometry was used to analyse polyphenol content, and the resulting data demonstrated that GOF-based flash chromatography can be used to efficiently separate polyphenols from sugars and can facilitate the removal of 95% of the sugar content. Flavonoids can be easily separated from phenolic acids. Chalcones and flavonols were eluted with 100% methanol and subsequently flavan-3-ols can be eluted with 0.04 M sodium hydroxide. The novel GOF has the potential to be used in the isolation of flavonoids.

Coherent Population Oscillation-Based Light Storage

We theoretically study the propagation and storage of a classical field in a Λ-type atomic medium using coherent population oscillations (CPOs). We show that the propagation eigenmodes strongly relate to the different CPO modes of the system. Light storage in such modes is discussed by introducing a "populariton" quantity, a mixture of populations and field, by analogy to the dark state polariton used in the context of electromagnetically induced transparency light storage protocol. As experimentally shown, this memory relies on populations and is then-by contrast with usual Raman coherence optical storage protocols-robust to dephasing effects.

Phase-sensitive amplification via coherent population oscillations in metastable helium at room temperature

In this Letter, we report our experimental results on phase-sensitive amplification (PSA) in a nondegenerate signal-idler configuration using ultranarrow coherent population oscillations in metastable helium at room temperature. We achieved a high PSA gain of nearly 7 with a bandwidth of 200 kHz by using the system at resonance in a single-pass scheme. Further, the measured minimum gain is close to the ideal value, showing that we have a nearly pure PSA. This is also confirmed from our phase-to-phase transfer curves measurements, illustrating that we have a nearly perfect squeezer, which is interesting for a variety of applications.

Attributions of Success and Failure

Using children from Canadian Caucasian and Asian Indian populations, the hypothesis was assessed that Asian children would attribute both success and failure in achievement tasks, to stable factors of ability and effort. By contrast, the prediction was that Caucasian children would asume personal responsibility only for success but would attribute failure to unstable factors of luck, task difficulty, and inaccuracy of the evaluator. The rationale employed was that socialization training in certain cultures provides impetus for assuming personal responsibility for both negative and positive outcomes. Ss were given two performance tasks with success and failure outcomes, under conditions of high and low ego involvement. As hypothesized, Caucasian Ss took greater personal credit for success and attributed failure to luck, but Asian Ss assumed more personal responsibility for failure and attributed success to luck. The implications of the attributional patterns were discussed in terms of the socialization of Asian children competing for success and self-enhancement with their Caucasian counterparts.

Measurement of Family Involvement

This article reports on the development of a cross-culturally validated standardized measure of family involvement. Family involvement is operationalized on the basis of the motivational formulation of involvement and alienation (Kanungo, 1979) and studied in a bi-national setting. Data from heterogeneous samples of 269 Indian and 168 Canadian employees reveal that the eight-item family involvement scale has satisfactory psychometric properties. The scale passes the tests of internal consistency, unidimensionality, and construct validity in samples from both the countries. The usefulness of the scale for research and professional work is discussed.