Antitumour potential of BPT: a dual inhibitor of cdk4 and tubulin polymerization

The marine natural product fascaplysin (1) is a potent Cdk4 (cyclin-dependent kinase 4)-specific inhibitor, but is toxic to all cell types possibly because of its DNA-intercalating properties. Through the design and synthesis of numerous fascaplysin analogues, we intended to identify inhibitors of cancer cell growth with good therapeutic window with respect to normal cells. Among various non-planar tryptoline analogues prepared, N-(biphenyl-2-yl) tryptoline (BPT, 6) was identified as a potent inhibitor of cancer cell growth and free from DNA-binding properties owing to its non-planar structure. This compound was tested in over 60 protein kinase assays. It displayed inhibition of Cdk4-cyclin D1 enzyme in vitro far more potently than many other kinases including Cdk family members. Although it blocks growth of cancer cells deficient in the mitotic-spindle checkpoint at the G0/G1 phase of the cell cycle, the block occurs primarily at the G2/M phase. BPT inhibits tubulin polymerization in vitro and acts as an enhancer of tubulin depolymerization of paclitaxel-stabilized tubulin in live cells. Western blot analyses indicated that, in p53-positive cells, BPT upregulates the expression of p53, p21 and p27 proteins, whereas it downregulates the expression of cyclin B1 and Cdk1. BPT selectively kills SV40-transformed mouse embryonic hepatic cells and human fibroblasts rather than untransformed cells. BPT inhibited the growth of several human cancer cells with an IC50<1 μM. The pharmacokinetic study in BALB/c mice indicated good plasma exposure after intravenous administration. It was found to be efficacious at 1/10th the maximum-tolerated dose (1000 mg/kg) against human tumours derived from HCT-116 (colon) and NCI-H460 (lung) cells in SCID (severe-combined immunodeficient) mice models. BPT is a relatively better anticancer agent than fascaplysin with an unusual ability to block two overlapping yet crucial phases of the cell cycle, mitosis and G0/G1. Its ability to effectively halt tumour growth in human tumour-bearing mice would suggest that BPT has the potential to be a candidate for further clinical development.

Efficacy of contrast enhanced grey scale ultrasound in characterisation of hepatic focal lesions: A pilot study

BACKGROUND

Contrast enhanced ultrasound (CEUS) has recently gained widespread acceptance as an adjunct to conventional grey scale ultrasound. The present pilot study was undertaken to evaluate the efficacy of this technique in characterisation of hepatic focal lesions.

METHODS

Adult patients who had at least one focal liver lesion underwent ultrasound evaluation in regular and contrast mode before and after intravenous administration of sulphur hexafluoride. The diagnoses were confirmed by comparison with a reference standard (multidetector CT), response to treatment or pathological correlation.

RESULTS

The rate of correct diagnosis for unenhanced ultrasound was 54%, CEUS was 72% and multidetector CT (MDCT) was 92%. A comparison of unenhanced ultrasound versus CEUS using the McNemar test yielded a p value of 0.0704 (>0.05). However, comparison of CEUS versus MDCT using the McNemar test yielded a p value of 0.0265 (<0.05). Additionally, comparison of unenhanced ultrasound versus MDCT using the McNemar test yielded a p value of <0.0001.

CONCLUSION

CEUS increases diagnostic efficacy over unenhanced ultrasound but does not have any significant advantages over MDCT. Currently it may be used as a problem solving tool in atypical haemangiomas, echogenic focal liver lesions, contrast sensitivity and to avoid multiple studies utilising ionising radiation.

Testing Aβ toxicity on primary CNS cultures using drug-screening microfluidic chips

Open microscale cultures of primary central nervous system (CNS) cells have been implemented in microfluidic chips that can expose the cells to physiological fluidic shear stress conditions. Cells in the chips were exposed to differently aggregated forms of beta-amyloid (Aβ), i.e. conditions mimicking an Alzheimer's Disease environment, and treated with CNS drugs in order to assess the contribution of glial cells during pharmacological treatments. FTY720, a drug approved for the treatment of Multiple Sclerosis, was found to play a marked neuroprotective role in neuronal cultures as well as in microglia-enriched neuronal cultures, preventing neurodegeneration after cell exposure to neurotoxic oligomers of Aβ.

Accuracy of intraocular lens power calculation in pediatric cataracts with less than a 20 mm axial length of the eye

INTRODUCTION

Selection of an appropriately-powered IOL is a complex issue, especially in eyes with an axial length of less than 20 mm in pediatric cataract.

OBJECTIVE

To assess the accuracy of IOL power calculation formulae in pediatric cataracts in eyes with an axial length of less than 20 mm.

MATERIALS AND METHODS

The records of children less than 15 years old with congenital cataract who had undergone primary IOL implantation were analyzed.

MAIN OUTCOME MEASURES

The variables studied were axial length, keratometric values and the prediction error. The data were analyzed for prediction error determination using the SRK II, SRK T, Holladay 1 and Hoffer Q IOL power calculation formulae. The formula that gave the best prediction error was identified.

RESULTS

Twenty-eight eyes of 19 children were included in the study. The absolute prediction error was found to be 1.84 ± 2.09 diopters (D) with SRK II, 2.93±3.55D with SRK T, 3.63±4.06D with Holladay 1, and 4.83±5.02D with Hoffer Q. The number of eyes with the absolute prediction error within 0.5 D was 6 (21.42%) with SRK II, 4 (14.28%) with SRK T, 1 (3.57%) with Holladay 1, and 3 (10.71%) with Hoffer Q. The absolute prediction error with SRK II formula was significantly better than that with other formulae (P less than .001). The axial length influenced the absolute prediction error with Hoffer Q formula (P = 0.04). The mean keratometry influenced the prediction error with SRK T formula (P = 0.02), Holladay 1 formula (P = 0.02) and Hoffer Q formula (P = 0.02).

CONCLUSION

Although the absolute prediction error tends to remain high with all the present IOL power calculation formulae, SRK II was the most predictable formula in this study.

Baked egg food challenges - clinical utility of skin test to baked egg and ovomucoid in children with egg allergy

BACKGROUND

Many children with IgE-mediated egg allergy can tolerate products containing extensively heated (baked) egg. Aside from food challenge, there are no tests which reliably predict tolerance to baked egg in egg-allergic individuals.

OBJECTIVES

To determine if skin prick test (SPT) to baked egg (muffin) and ovomucoid can predict the outcome of baked egg challenges in egg allergic patients.

METHODS

In this prospective study, children with a recent history of immediate allergic reactions to egg [and corroborative positive SPT or serum-specific IgE (ssIgE) to egg] or those with SPT/ssIgE > 95% PPV for egg allergy were invited to undergo an open standardized baked egg (muffin) challenge. SPT to egg white, ovomucoid, and fresh muffin were performed immediately prior to challenge.

RESULTS

One hundred and forty-three egg allergic children underwent baked egg challenge and of these, 90 (63%) tolerated 1 g of egg protein in a baked muffin. Of the 53 positive challenges, eight (15%) had respiratory and/or cardiovascular symptoms. The median SPT diameters in positive challenges compared with negative challenges were baked muffin - 6.0 mm/4.0 mm and ovomucoid 7.5 mm/5.0 mm respectively. Receiver operating characteristic (ROC) curves were generated for SPT to baked egg and ovomucoid. The area under the curve was 0.68 for baked egg, and 0.67 for ovomucoid. A muffin SPT of < 2 mm had a negative predictive value of 88% and an ovomucoid SPT ≥ 11 mm had a positive predictive value of 100%.

CONCLUSIONS AND CLINICAL RELEVANCE

A SPT of < 2 mm to muffin had a high negative predictive value to baked egg challenge. Ovomucoid SPT ≥ 11 mm was very likely to predict a reaction to baked egg. In these children, deferring the challenge would be appropriate.

Quantifying contextuality

Contextuality is central to both the foundations of quantum theory and to the novel information processing tasks. Despite some recent proposals, it still faces a fundamental problem: how to quantify its presence? In this work, we provide a universal framework for quantifying contextuality. We conduct two complementary approaches: (i) the bottom-up approach, where we introduce a communication game, which grasps the phenomenon of contextuality in a quantitative manner; (ii) the top-down approach, where we just postulate two measures, relative entropy of contextuality and contextuality cost, analogous to existent measures of nonlocality (a special case of contextuality). We then match the two approaches by showing that the measure emerging from the communication scenario turns out to be equal to the relative entropy of contextuality. Our framework allows for the quantitative, resource-type comparison of completely different games. We give analytical formulas for the proposed measures for some contextual systems, showing in particular that the Peres-Mermin game is by order of magnitude more contextual than that of Klyachko et al. Furthermore, we explore properties of these measures such as monotonicity or additivity.

Glyceraldehyde-3-phosphate dehydrogenase of the parasitic nematode Haemonchus contortus binds to complement C3 and inhibits its activity

Haemonchus contortus is an economically important gastrointestinal parasite that infects primarily sheep and goats. To survive inside the host, the parasite must overcome the host immune response. In this study, we have identified and characterized a complement-C3-binding protein (H.c-C3BP) from this parasite employing biochemical and molecular biology tools. Initially, a truncated form of the protein was isolated from the excretory-secretory products of the parasite using C3-Sepharose column that facilitated its identification by mass spectroscopy. Subsequently, the parent molecule was generated in E. coli, and sequence analysis confirmed it as glyceraldehyde-3-phosphate dehydrogenase (GAPDH). GAPDH reacted with the antiserum raised against the truncated protein, and the truncated protein reacted with anti-GAPDH antiserum. The protein inhibited complement function as measured by haemolytic assay and membrane attack complex (MAC) formation. Sera from H. contortus-infected animals reacted with GAPDH as well as the truncated form of the protein, which further lend support to protein secretion. Thus, the C3-binding property of H. contortus GAPDH is a new function, and it represents a new entity of complement-binding protein. Identification and characterization of H.c-C3BP should facilitate development of new therapeutics considering a key role of this protein in immune modulation.

Microglia convert aggregated amyloid-β into neurotoxic forms through the shedding of microvesicles

Alzheimer's disease (AD) is characterized by extracellular amyloid-β (Aβ) deposition, which activates microglia, induces neuroinflammation and drives neurodegeneration. Recent evidence indicates that soluble pre-fibrillar Aβ species, rather than insoluble fibrils, are the most toxic forms of Aβ. Preventing soluble Aβ formation represents, therefore, a major goal in AD. We investigated whether microvesicles (MVs) released extracellularly by reactive microglia may contribute to AD degeneration. We found that production of myeloid MVs, likely of microglial origin, is strikingly high in AD patients and in subjects with mild cognitive impairment and that AD MVs are toxic for cultured neurons. The mechanism responsible for MV neurotoxicity was defined in vitro using MVs produced by primary microglia. We demonstrated that neurotoxicity of MVs results from (i) the capability of MV lipids to promote formation of soluble Aβ species from extracellular insoluble aggregates and (ii) from the presence of neurotoxic Aβ forms trafficked to MVs after Aβ internalization into microglia. MV neurotoxicity was neutralized by the Aβ-interacting protein PrP and anti-Aβ antibodies, which prevented binding to neurons of neurotoxic soluble Aβ species. This study identifies microglia-derived MVs as a novel mechanism by which microglia participate in AD degeneration, and suggest new therapeutic strategies for the treatment of the disease.

Molecular characterization and expression profile of ghrelin gene during different reproductive phases in buffalo (Bubalus bubalis)

Ghrelin, a novel motilin-related endogenous ligand for growth hormone secretagouge receptor, is implicated in various biological functions, including regulation of female reproduction. But the presence of ghrelin and its role in reproductive functions in buffalo, a species with poor reproductive efficiency, is not known. In the present study full-length ghrelin cDNA was isolated from bubaline abomasum, which encodes the entire prepropeptide of 116 amino acids. The deduced amino acid sequence of ghrelin of buffalo showed >95% and 31% identity with that of ruminants (cattle, sheep, and goat) and humans, respectively. Analysis of synonymous and nonsynonymous nucleotide substitutions in the coding region of ghrelin indicated that these sequences of different species have been under purifying selection. The 3995-bp amplicon of ghrelin gene consisting of 4 exons and 3 introns was cloned with genomic DNA from buffalo. Further, ghrelin expression was determined by quantitative real-time PCR, in situ hybridization, and immunohistochemistry in bubaline endometrial tissues at different stages of the estrous cycle and early pregnancy. Our results indicated the persistent expression of ghrelin mRNA and protein in the endometrium during stage I (day 3-5), stage II (day 6-15), and stage III (day 16-21) of the estrous cycle and also during early (~day 30-40) pregnancy. Immunohistochemistry and quantitative real-time PCR experiments indicated the relatively higher expression of ghrelin in the endometrium during stage II (day 6-15) of the estrous cycle and early pregnancy than during stage I (day 3-5) and stage III (day 16-21) of the estrous cycle, but no statistically significant difference in ghrelin expression was observed among stages. To conclude, the results of the present study indicate the persistent expression of ghrelin in the uterine endometrium throughout the estrous cycle and in early pregnancy which might be helpful in determining its role in buffalo reproduction.

Carotid sheath lipoma: first case report in the English literature

Lipomas are the most commonly encountered benign mesenchymal tumour, arising in any location where fat is normally present. Lipomas in the head and neck are rare in all age groups. Cases of vascular sheath lipomas in the femoral region have only been reported in adults. In children, vascular sheath lipomas have not been described to date. We report the first case of a carotid sheath lipoma in a seven-year-old boy. He had a non-tender soft mass with ill defined borders occupying the left upper part of the neck. Magnetic resonance imaging showed a mass at the bifurcation of the left common carotid artery without involving the same. The mass was hyperintense on T1 and T2 weighted sequences, suggestive of a lipoma. The lipoma was enucleated after incising the carotid sheath, safeguarding its contents. Histopathology confirmed it as a lipoma.

The economic burden of traumatic spinal cord injury in Canada

INTRODUCTION

The purpose of this study is to estimate the current lifetime economic burden of traumatic spinal cord injury (tSCI) in Canada from a societal perspective, including both direct and indirect costs, using an incidence-based approach.

METHODS

Available resource use and cost information for complete/incomplete tetraplegia and paraplegia was applied to the estimated annual incidence of tSCI, by severity, in Canada.

RESULTS

The estimated lifetime economic burden per individual with tSCI ranges from $1.5 million for incomplete paraplegia to $3.0 million for complete tetraplegia. The annual economic burden associated with 1389 new persons with tSCI surviving their initial hospitalization is estimated at $2.67 billion.

CONCLUSION

While the number of injuries per year in Canada is relatively small, the annual economic burden is substantial.

The economic burden of traumatic spinal cord injury in Canada

Introduction

The purpose of this study is to estimate the current lifetime economic burden of traumatic spinal cord injury (tSCI) in Canada from a societal perspective, including both direct and indirect costs, using an incidence-based approach.

Methods

Available resource use and cost information for complete/incomplete tetraplegia and paraplegia was applied to the estimated annual incidence of tSCI, by severity, in Canada.

Results

The estimated lifetime economic burden per individual with tSCI ranges from $1.5 million for incomplete paraplegia to $3.0 million for complete tetraplegia. The annual economic burden associated with 1389 new persons with tSCI surviving their initial hospitalization is estimated at $2.67 billion.

Conclusion

While the number of injuries per year in Canada is relatively small, the annual economic burden is substantial.

Health in Nepalese media

BACKGROUND

Coverage of health in Nepali print media is quite a recent phenomenon despite readers' ample appetite for it. Dominated by politics, Nepal's print media has been marginally publishing news pieces, features, editorials and op-ed articles, photographs and cartoons on health, though marginally. But the media did not wake up to the issues of human resources for health until lately.

METHODS

We content analysed the coverage of health issues including, human resources for health in select Nepali print media Kantipur, Nagarik and Annapurna Post of select three months in 2012 April, August and December. News pieces and their placements, Op-eds, editorials, features, letters to the editor, photos and cartoons were subjected to analysis.

RESULTS

Over the study period, the papers covered 544 health news pieces, 44% of political news pieces. Health workforce news pieces contributed 24% to it. However, only 10% of the health news made to the front pages. Coverage of health in editorials, features, Op-eds, photographs, cartoons and letters to the editor is even more meager. For example, only 7% of the editorials are relating to health.

CONCLUSIONS

Health is prioritized far less by the print media than politics despite the reader's appetite for it. Print media should give health a top priority, particularly in those areas that relate to health systems like human resources for health, for their massive impact on the lives of the people.

A Functional Proteomics Perspective of DBC1 as a Regulator of Transcription

The past few years have seen significant advances in the use of modern proteomics approaches for biological discoveries. Among the fields impacted by proteomics is that of epigenetics, as mass spectrometry-based approaches have allowed the identification and characterization of transcriptional regulators, epigenetic marks, and the constantly evolving epigenetic landscape of a cell in health and disease states. These studies have substantially expanded our understanding of critical genes that mediate cell processes, such as differentiation, cell cycle regulation, and apoptosis. Not surprisingly, a great emphasis has been placed on defining factors that are de-regulated in cancers, in an attempt to define new and specific targets for therapeutic design. Differential gene expression observed during carcinogenesis can be induced by aberrant activities of transcription factors and chromatin remodeling enzymes. Through a series of recent mass spectrometry studies of histone deacetylases and nuclear receptors, Deleted in Breast Cancer 1 (DBC1) has emerged as a master regulator of transcriptional processes. DBC1 acts as a modulator of cellular epigenetic mechanisms and is frequently associated with human metastasis. Through its negative regulation of SIRT1 and HDAC3 deacetylation activities, DBC1 has a broad impact on gene expression, downstream cellular pathways, and associated human diseases. Here, we review the identified roles of DBC1, highlighting the critical contribution of mass spectrometry to these findings. Additionally, we provide a perspective of integrative proteomics approaches that can continue to shed light on the interplay between DBC1 and its protein targets, helping to further define its role in epigenetic modifications and to identify novel targets for cancer therapy.

Dosimetric comparison between bone marrow sparing intensity-modulated radiation therapy and conventional techniques in the treatment of cervical cancer: a retrospective study

PURPOSE

To investigate enlargement of prostate volume by edema during brachytherapy seed implantation and develop a nomogram model to calculate air-kerma strength (AKS) required for implantation of the enlarged transient prostatic volume.

MATERIALS AND METHODS

The prostate volume was measured prior and after seed implantation using trans-rectal ultrasound imaging in the operating room to obtain volume enlargement. A nomogram model was developed that calculates AKS required for implantation of the enlarged transient prostate volume with optimal dose coverage.

RESULTS

The measured prostate enlargement in this study was up to 60% of the initial volume. The effective prostatic volume enlargement was calculated for three isotopes: 125I, 103Pd and 131Cs. The effective volume enlargement for 125I implants was relatively small (< 10%) because of its long half-life. For 103Pd and 131Cs with short half-lives, additional AKS up to 20% and 30%, respectively, might be required to provide appropriate dose coverage of possible enlarged prostatic volumes.

CONCLUSIONS

Prostate volume enlargement should be considered to obtain optimal dose coverage particularly for short half-life isotopes such as 131Cs and 103Pd. The nomogram model developed in this work provides the AKS required for implants with a wide range of prostatic volume enlargements (5-100%) for three isotopes.

KEYWORDS

prostate brachytherapy, nomogram, airkerma strength, edema, volume enlargement.

Post Caesarean Caecal Perforation with Fecal Peritonitis

NJOG 2011 Nov-Dec; 6 (2): 58-59 DOI: http://dx.doi.org/10.3126/njog.v6i2.6762

Sexual health professionals' evaluations of a prototype computer-based contraceptive planning intervention for adolescents: implications for practice

BACKGROUND

This paper aims to demonstrate how an online planning intervention to enhance contraceptive and condom use among adolescents was viewed by sexual health professionals. It identifies feedback that has facilitated improvement of the intervention both in terms of potential effectiveness and sustainability in practice. The data illustrate how professionals' feedback can enhance intervention development.

METHOD

Ten practitioners (two male; eight female) representing a range of roles in sexual health education and healthcare were given electronic copies of the prototype intervention. Interviews were conducted to elicit feedback. Transcripts of the interviews were subjected to thematic analysis.

RESULTS

Practitioners provided positive feedback about the intervention content, use of on-line media, the validity of planning techniques and the inclusion of males in contraceptive planning. Issues with rapport building, trust, privacy, motivation, and time and resources were raised, however, and the promotion of condom carrying was contentious.

CONCLUSIONS

Professionals' feedback provided scope for developing the intervention to meet practitioners' concerns, thus enhancing likely feasibility and acceptability in practice. Ways in which particular feedback was generalisable to wider theory-based and online intervention development are explored. Some responses indicated that health practitioners would benefit from training to embed theory-based interventions into sexual health education and healthcare.

Gefitinib Monotherapy in Advanced non-small-cell Lung Cancer: A Retrospective Analysis

Introduction: There is no published data in Nepal regarding the use of gefi tinib in patients with non-small cell lung cancer (NSCLC). Therefore, a retrospective analysis was conducted to evaluate the response and toxicity profi le of Gefi tinib alone in patients with advanced NSCLC and unknown epidermal growth factor receptor (EGFR) status. Methods: A single institutional retrospective study was conducted for the period from January 2004 to December 2006 involving patients with locally advanced or metastatic NSCLC who received gefi tinib as monotherapy Primary objective was to evaluate the objective tumor response rate. Results: A total of 36 patients with advanced NSCLC who received gefi tinib 250 mg orally once daily as 1st, 2nd, 3rd, and 4th line treatment in 7, 14, 9, and 6 patients respectively were included in the analysis. Comparable number of patients pertaining to sex, smoking status, and tumor histology were included. The overall response rate at 3 months was 60% including 47% in males and 68% in females. After one month 38% and 6.6% patients with adenocarcinoma and squamous histology respectively responded to gefi tinib therapy. The median progression-free survival was 5.7 months. Toxicities were generally mild with diarrhea, rash and pruritus being the most commonly observed side effects. Conclusion: In this single-center experience, gefi tinib demonstrated clinically signifi cant response in overall population and provided good palliation in pretreated patients. Keywords: Advanced stage NSCLCs, EGFR-TKIs, Gefitinib, monotherapy, Nepal.

Gefitinib monotherapy in advanced non-small-cell lung cancer: a retrospective analysis

INTRODUCTION

There is no published data in Nepal regarding the use of gefitinib in patients with non-small cell lung cancer (NSCLC). Therefore, a retrospective analysis was conducted to evaluate the response and toxicity profile of Gefitinib alone in patients with advanced NSCLC and unknown epidermal growth factor receptor (EGFR) status.

METHODS

A single institutional retrospective study was conducted for the period from January 2004 to December 2006 involving patients with locally advanced or metastatic NSCLC who received gefitinib as monotherapy Primary objective was to evaluate the objective tumor response rate.

RESULTS

A total of 36 patients with advanced NSCLC who received gefitinib 250 mg orally once daily as 1st, 2nd, 3rd, and 4th line treatment in 7, 14, 9, and 6 patients respectively were included in the analysis. Comparable number of patients pertaining to sex, smoking status, and tumor histology were included. The overall response rate at 3 months was 60% including 47% in males and 68% in females. After one month 38% and 6.6% patients with adenocarcinoma and squamous histology respectively responded to gefitinib therapy. The median progression-free survival was 5.7 months. Toxicities were generally mild with diarrhea, rash and pruritus being the most commonly observed side effects.

CONCLUSION

In this single-center experience, gefitinib demonstrated clinically significant response in overall population and provided good palliation in pretreated patients.

Evidence for a spin-aligned neutron-proton paired phase from the level structure of (92)Pd

Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing, in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus (92)Pd. Gamma rays emitted following the (58)Ni((36)Ar,2n)(92)Pd fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution γ-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction. We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.

Surface-mediated synthesis of organophosphorus-based hydrazides using basic alumina

The surface-mediated synthesis of O-alkyl alkylphosphorohydrazides and N,N-dialkylamino alkylphosphorohydrazides from phosphoryl chlorides is described. The effect of the presence of chromatographic-grade Al2O3(basic) on the hydrazinolysis of a series of O-alkyl alkylphosphonic chlorides and N,N-dialkylamino alkylphosphonic chlorides has also been investigated. It was observed that higher yields of the less-hindered hydrazides were obtained

Intrinsic doping and gate hysteresis in graphene field effect devices fabricated on SiO2 substrates

We have studied the intrinsic doping level and gate hysteresis of graphene-based field effect transistors (FETs) fabricated over Si/SiO(2) substrates. It was found that the high p-doping level of graphene in some as-prepared devices can be reversed by vacuum degassing at room temperature or above depending on the degree of hydrophobicity and/or hydration of the underlying SiO(2) substrate. Charge neutrality point (CNP) hysteresis, consisting of the shift of the charge neutrality point (or Dirac peak) upon reversal of the gate voltage sweep direction, was also greatly reduced upon vacuum degassing. However, another type of hysteresis, consisting of the change in the transconductance upon reversal of the gate voltage sweep direction, persists even after long-term vacuum annealing at 200 °C, when SiO(2) surface-bound water is expected to be desorbed. We propose a mechanism for this transconductance hysteresis that involves water-related defects, formed during the hydration of the near-surface silanol groups in the bulk SiO(2), that can act as electron traps.

Impact of alcohol on coronary heart disease in Indian men

BACKGROUND

Moderate alcohol consumption is known to be protective against coronary heart disease (CHD). However, the INTERHEART study, a case-control study of acute myocardial infarction (MI) patients, revealed that alcohol consumption in South Asians was not protective against CHD. We therefore planned to study cardiovascular risk factor and CHD prevalence among male alcohol users as compared to age matched lifetime abstainers.

METHODS

The subjects for this study were recruited from a cross-sectional survey carried out among employees and their family members aged 20-69 years in 10 medium-to-large industries from diverse sites in India, using a stratified random sampling technique. Information on education, behavioral, clinical and biochemical risk factors of CHD and alcohol use was obtained through standardized instruments. CHD diagnosis was based on Rose Questionnaire or a prior physician diagnosed CHD.

RESULTS

A total of 4465 subjects were present or past alcohol users. The mean age of alcohol users and lifetime abstainers was 42.8+/-11.0 years and 42.8+/-11.1 years, respectively (p=0.90). Systolic blood pressure and diastolic blood pressure were significantly higher in alcohol users (128.7+/-17.6 mmHg/80.1+/-11.3 mmHg) as compared to lifetime abstainers (126.9+/-15.9 mmHg/79.5+/-10.3 mmHg, p<0.01). Fasting blood sugar in alcohol users (98.7+/-30.5 mg%) was also significantly higher than lifetime abstainers (96.6+/-26.0 mg%, p<0.01). Total cholesterol was lower in alcohol users (179.1+/-41.1 mg%) as compared to lifetime abstainers (182.7+/-38.2 mg%, p<0.01). HDL cholesterol was higher in alcohol users (42.9+/-10.8 mg%) as compared to lifetime abstainers (41.3+/-10.0 mg%, p<0.01). Body mass index (BMI) was lower in alcohol users as compared to lifetime abstainers (22.7+/-4.1 kg/m2 vs. 24.0+/-3.3 kg/m2, p<0.001). Tobacco use was significantly higher in alcohol users (63.1% vs. 20.7%). The odds ratio (OR) of having CHD after adjusting for tobacco use, BMI and education was 1.4 (95%CI 1.0-1.9) in alcohol users as compared to controls. The OR was 1.2 (95%CI 0.8-1.6) in occasional alcohol users, 1.6 (95%CI 1.0-2.2) in regular alcohol users and 2.1 (95% CI 1.1-3.0) in past alcohol users as compared to controls.

CONCLUSION

We did not observe an inverse (protective) association between alcohol intake and the prevalence of CHD. In contrast, our study indicated an association in the reverse direction, suggesting possible harm of alcohol for coronary risk in Indian men. This relationship needs to be further examined in large, prospective study.