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Lingineni RK, Biswas S, Ahmad N, Jackson BE, Bae S, Singh KP. Factors associated with attention deficit/hyperactivity disorder among US children: results from a national survey. BMC Pediatr 2012; 12:50. [PMID: 22583686 PMCID: PMC3502478 DOI: 10.1186/1471-2431-12-50] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 04/17/2012] [Indexed: 12/01/2022] Open
Abstract
Background The purpose of this study was to investigate the association between Attention Deficit/Hyperactivity Disorder (ADHD) and various factors using a representative sample of US children in a comprehensive manner. This includes variables that have not been previously studied such as watching TV/playing video games, computer usage, family member’s smoking, and participation in sports. Methods This was a cross-sectional study of 68,634 children, 5–17 years old, from the National Survey of Children’s Health (NSCH, 2007–2008). We performed bivariate and multivariate logistic regression analyses with ADHD classification as the response variable and the following explanatory variables: sex, race, depression, anxiety, body mass index, healthcare coverage, family structure, socio-economic status, family members’ smoking status, education, computer usage, watching television (TV)/playing video games, participation in sports, and participation in clubs/organizations. Results Approximately 10% of the sample was classified as having ADHD. We found depression, anxiety, healthcare coverage, and male sex of child to have increased odds of being diagnosed with ADHD. One of the salient features of this study was observing a significant association between ADHD and variables such as TV usage, participation in sports, two-parent family structure, and family members’ smoking status. Obesity was not found to be significantly associated with ADHD, contrary to some previous studies. Conclusions The current study uncovered several factors associated with ADHD at the national level, including some that have not been studied earlier in such a setting. However, we caution that due to the cross-sectional and observational nature of the data, a cause and effect relationship between ADHD and the associated factors can not be deduced from this study. Future research on ADHD should take into consideration these factors, preferably through a longitudinal study design.
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Biswas S, Dodwadkar NS, Deshpande PP, Torchilin VP. Liposomes loaded with paclitaxel and modified with novel triphenylphosphonium-PEG-PE conjugate possess low toxicity, target mitochondria and demonstrate enhanced antitumor effects in vitro and in vivo. J Control Release 2012. [PMID: 22286008 DOI: 10.1016/ljc0nrel.2012.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
Previously, stearyl triphenylphosphonium (STPP)-modified liposomes (STPP-L) were reported to target mitochondria. To overcome a non-specific cytotoxicity of STPP-L, we synthesized a novel polyethylene glycol-phosphatidylethanolamine (PEG-PE) conjugate with the TPP group attached to the distal end of the PEG block (TPP-PEG-PE). This conjugate was incorporated into the liposomal lipid bilayer, and the modified liposomes were studied for their toxicity, mitochondrial targeting, and efficacy in delivering paclitaxel (PTX) to cancer cells in vitro and in vivo. These TPP-PEG-PE-modified liposomes (TPP-PEG-L), surface grafted with as high as 8 mol% of the conjugate, were less cytotoxic compared to STPP-L or PEGylated STPP-L. At the same time, TPP-PEG-L demonstrated efficient mitochondrial targeting in cancer cells as shown by confocal microscopy in co-localization experiments with stained mitochondria. PTX-loaded TPP-PEG-L demonstrated enhanced PTX-induced cytotoxicity and anti-tumor efficacy in cell culture and mouse experiments compared to PTX-loaded unmodified plain liposomes (PL). Thus, TPP-PEG-PE can serve as a targeting ligand to prepare non-toxic liposomes as mitochondria-targeted drug delivery systems (DDS).
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Tiwary G, Gangopadhyay PK, Biswas S, Nayak K, Chatterjee MK, Chakraborty D, Mukherjee S. Socio-economic status of workers of building construction industry. Indian J Occup Environ Med 2012; 16:66-71. [PMID: 23580836 PMCID: PMC3617510 DOI: 10.4103/0019-5278.107072] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Informal/unorganised sector covers 92% of the total work force in India. About 50% of the construction industrial workers belonged to informal/unorganised sector. MATERIAL AND METHODS The present study was undertaken to know the socio-economic status of construction worker and availing of the social security measures by this working group. RESULTS AND CONCLUSION The study covered 150 subjects with an average age of 32 years and mean duration of work was nine years. They were poorly paid with an average income of Rs. 4956/-per month. Though the literacy rate was high (79%) yet most of them were addicted to different habits like drinking alcohol, smoking bidi, tobacco chewing etc., Abusing the family members were noted in (30%) of the cases. Their regular intake of food, usually inadequate in quantity and was mainly consisted of rice, pulses, vegetables. Though most of the subjects (73%) were living in kacha houses yet the latrine facilities were available to 62% of total covered houses. Majority of them were unaware of the different social security schemes/measures. The details have been discussed here.
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Navarro G, Sawant RR, Biswas S, Essex S, Tros de Ilarduya C, Torchilin VP. P-glycoprotein silencing with siRNA delivered by DOPE-modified PEI overcomes doxorubicin resistance in breast cancer cells. Nanomedicine (Lond) 2012; 7:65-78. [PMID: 22191778 DOI: 10.2217/nnm.11.93] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
AIMS Multidrug resistance (MDR) mediated by overexpression of drug efflux transporters such as P-glycoprotein (P-gp), is a major problem, limiting successful chemotherapy of breast cancer. The use of siRNA to inhibit P-gp expression in MDR tumors is an attractive strategy to improve the effectiveness of anticancer drugs. METHOD We have synthesized a novel conjugate between a phospholipid (dioleoylphosphatidylethanolamine) and polyethylenimine (PEI) for siRNA delivery, for the purpose of silencing P-gp to overcome doxorubicin resistance in MCF-7 human breast cancer cells. RESULTS The dioleoylphosphatidylethanolamine-PEI conjugate enhanced the transfection efficacy of low-molecular-weight PEI, which was otherwise totally ineffective. In addition, the polyethylene glycol/lipid coating of the new complexes gave rise to small micelle-like nanoparticles with improved biocompatibility properties. Both coated and noncoated formulations delivered P-gp-specific siRNA to MDR cells. DISCUSSION The combination of doxorubicin and P-gp silencing formulations led to a twofold increase of doxorubicin uptake and a significant improvement of the therapeutic effect of doxorubicin in resistant cells.
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Rana T, Schultz MI, Freeman MI, Biswas S. Abstract 2065: Loss of Nrf2 increases susceptibility to radiation induced bone loss. Cancer Res 2012. [DOI: 10.1158/1538-7445.am2012-2065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
A fundamental clinical complication in the treatment of patients with metastatic breast cancer is severe bone loss. Patients with breast cancer routinely received both chemotherapy and radiotherapy, both are known to increase oxidative stress and bone loss. Underlying mechanism of cancer therapy induced bone loss is poorly understood. We have previouslyreported that treatment with radiation (RT) increases TGFβ1 levels in mice. TGFβ1 increases oxidative stress by induction of reactive oxygen species (ROS). TGFβ1 increases oxidative stress by induction of reactive oxygen species (ROS). TGFβ1/Smad3 signaling suppresses Nrf2 (Nuclear factor erythroid-derived 2), a master transcription factor that positively regulates induction of antioxidant gene expression resulting in elevated ROS levels. Our objective is to test the hypothesis whether loss of Nrf2 gene increases the radiation induced bone loss. We have used age matched wild type control and Nrf2-/- mice. Mice were irradiated (single dose, 20 Gy) on the hind legs and microCT analysis was done to measure the overall bone loss. A similar increase in bone loss was noted in mice following histological analysis of the long bones. Additionally, reduction in osteoblast colony forming units and osteoblast differentiation were also noted. We have seen a higher number of osteoclasts in Nrf2-/- mice compared to wild type control and following radiation, the trend remains same. We conclude that, loss of Nrf2 leads to incraesed susceptibility to the radiation induced bone damage.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2065. doi:1538-7445.AM2012-2065
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Biswas S, Adhikari A, Chattopadhyay JC, Ghosh SK. Histological changes of placentas associated with intra-uterine growth restriction of fetuses: a case control study. NEPAL MEDICAL COLLEGE JOURNAL : NMCJ 2012; 14:18-24. [PMID: 23441489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Placenta is the maternal-fetal contact zone. The placentas of "idiopathic" intra-uterine growth restriction (IUGR) babies may hold the key to the etiology of growth restriction. The present study primarily aimed at evaluating the structural peculiarities of IUGR placenta. The study was conducted on 35 IUGR and 25 control placentas. Placental tissues were processed for routine histological studies, to determine numbers of syncytial knots in villi and X-cells in the basal plate. Light microscopy suggested that syncytiotrophoblastic lining was more degenerated and number of syncytial knots increased in IUGR placentas than that of the control placentas. X cells were present in both the cases, though more in IUGR. Intravillous and perivillous fibrin depositions were markedly increased in IUGR; also there were more hypovascular/avascular villi and large areas of infarction. Cumulative effects of several placental injuries, e.g. poor perfusion, presence of increased number of X-cells, increased fibrin deposition; etc for a sufficient time were likely cause of IUGR.
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Sawant RR, Sriraman SK, Navarro G, Biswas S, Dalvi RA, Torchilin VP. Polyethyleneimine-lipid conjugate-based pH-sensitive micellar carrier for gene delivery. Biomaterials 2012; 33:3942-51. [PMID: 22365809 DOI: 10.1016/j.biomaterials.2011.11.088] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 11/29/2011] [Indexed: 12/01/2022]
Abstract
A low molecular weight polyethyleneimine (PEI 1.8 kDa) was modified with dioleoylphosphatidylethanolamine (PE) to form the PEI-PE conjugate investigated as a transfection vector. The optimized PEI-PE/pDNA complexes at an N/P ratio of 16 had a particle size of 225 nm, a surface charge of +31 mV, and protected the pDNA from the action of DNase I. The PEI-PE conjugate had a critical micelle concentration (CMC) of about 34 μg/ml and exhibited no toxicity compared to a high molecular weight PEI (PEI 25 kDa) as tested with B16-F10 melanoma cells. The B16-F10 cells transfected with PEI-PE/pEGFP complexes showed protein expression levels higher than with PEI-1.8 or PEI-25 vectors. Complexes prepared with YOYO 1-labeled pEGFP confirmed the enhanced delivery of the plasmid with PEI-PE compared to PEI-1.8 and PEI-25. The PEI-PE/pDNA complexes were also mixed with various amounts of micelle-forming material, polyethylene glycol (PEG)-PE to improve biocompatibility. The resulting particles exhibited a neutral surface charge, resistance to salt-induced aggregation, and good transfection activity in the presence of serum in complete media. The use of the low-pH-degradable PEG-hydrazone-PE produced particles with transfection activity sensitive to changes in pH consistent with the relatively acidic tumor environment.
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Dickson MJ, Biswas S. Re: Missed opportunities for type 2 diabetes testing following gestational diabetes: a population-based cohort study. BJOG 2012; 119:505-6. [PMID: 22324923 DOI: 10.1111/j.1471-0528.2011.03238.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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359
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Biswas S, Tankhiwale N, Blackford A, Barrera AMG, Ready K, Lu K, Amos CI, Parmigiani G, Arun B. Assessing the added value of breast tumor markers in genetic risk prediction model BRCAPRO. Breast Cancer Res Treat 2012; 133:347-55. [DOI: 10.1007/s10549-012-1958-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 01/10/2012] [Indexed: 12/19/2022]
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Biswas S, Dodwadkar NS, Deshpande PP, Torchilin VP. Liposomes loaded with paclitaxel and modified with novel triphenylphosphonium-PEG-PE conjugate possess low toxicity, target mitochondria and demonstrate enhanced antitumor effects in vitro and in vivo. J Control Release 2012; 159:393-402. [PMID: 22286008 DOI: 10.1016/j.jconrel.2012.01.009] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 01/09/2012] [Accepted: 01/12/2012] [Indexed: 12/12/2022]
Abstract
Previously, stearyl triphenylphosphonium (STPP)-modified liposomes (STPP-L) were reported to target mitochondria. To overcome a non-specific cytotoxicity of STPP-L, we synthesized a novel polyethylene glycol-phosphatidylethanolamine (PEG-PE) conjugate with the TPP group attached to the distal end of the PEG block (TPP-PEG-PE). This conjugate was incorporated into the liposomal lipid bilayer, and the modified liposomes were studied for their toxicity, mitochondrial targeting, and efficacy in delivering paclitaxel (PTX) to cancer cells in vitro and in vivo. These TPP-PEG-PE-modified liposomes (TPP-PEG-L), surface grafted with as high as 8 mol% of the conjugate, were less cytotoxic compared to STPP-L or PEGylated STPP-L. At the same time, TPP-PEG-L demonstrated efficient mitochondrial targeting in cancer cells as shown by confocal microscopy in co-localization experiments with stained mitochondria. PTX-loaded TPP-PEG-L demonstrated enhanced PTX-induced cytotoxicity and anti-tumor efficacy in cell culture and mouse experiments compared to PTX-loaded unmodified plain liposomes (PL). Thus, TPP-PEG-PE can serve as a targeting ligand to prepare non-toxic liposomes as mitochondria-targeted drug delivery systems (DDS).
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361
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Gupta A, Raman R, Biswas S, Rajan R, Kulothungan V, Sharma T. Association between various types of obesity and macular pigment optical density. Eye (Lond) 2012; 26:259-66. [PMID: 22222262 DOI: 10.1038/eye.2011.328] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To elucidate the association between macular pigment optical density (MPOD) and various types of obesity in the South-Indian population. PATIENTS AND METHODS In total, 300 eyes of 161 healthy volunteers of South-Indian origin were studied. MPOD was measured psychophysically at 0.25°, 0.50°, 1.00°, and 1.75° eccentricities from fovea. Anthropometric measurements included waist circumference (WC) and waist-to-hip ratio (WHR) and body mass index (BMI). Using the WHO Expert Consultation guidelines, obesity was defined based on BMI alone (BMI ≥ 23 kg/m(2)), based on WC alone (WC ≥ 90 cm for men and ≥ 80 cm for women), and based on WHR alone (≥ 0.90 for men and ≥ 0.85 for women). Isolated generalized obesity was defined as increased BMI and normal WC. Isolated abdominal obesity was defined as increased WC and normal BMI. Combined obesity was defined as increased BMI and increased WC. RESULTS Mean MPOD at all eccentricities was not significantly different between men and women. Mean MPOD values did not significantly differ in various types of obesity, when compared with the normal subjects. On subgroup analysis, in age group ≥ 60 years, mean MPOD values were significantly higher in subjects with obesity based on BMI (0.61 vs 0.41, P=0.036), obesity based on WHR (0.67 vs 0.41, P=0.007), and isolated generalized obesity (0.66 vs 0.41, P=0.045) in comparison with normal subjects at 0.25° eccentricity. CONCLUSION We found lack of an association between MPOD and obesity in the South-Indian population. A similar finding was also noted on age group- and gender-wise analyses.
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362
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Biswas S, Lin S. A Bayesian Approach for Incorporating Variable Rates of Heterogeneity in Linkage Analysis. J Am Stat Assoc 2012. [DOI: 10.1198/016214506000000609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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363
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Cole J, Ajani A, Andrianopoulos N, Duffy S, Black A, Brennan A, New G, Vaidya S, Biswas S, Watts M, Clark D. Zotarolimus and Everolimus DES: Which Should You Choose? Heart Lung Circ 2012. [DOI: 10.1016/j.hlc.2012.05.457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Maity T, Adhikari A, Bhattacharya K, Biswas S, Debnath PK, Maharana CS. A study on evalution of antidepressant effect of imipramine adjunct with Aswagandha and Bramhi. NEPAL MEDICAL COLLEGE JOURNAL : NMCJ 2011; 13:250-253. [PMID: 23016473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Depressive disorders increase the risks of self-harm or even suicide in patients. Indigenous drugs are being tried to treat such patient along with conventional antidepressant drugs. This study was planned to investigate the antidepressant action of Ashwagandha and Bramhi and also to confirm its efficacy in the behavioural despair animal model of depression. Normal saline as control (5 ml/kg), Imipramine as standard (16, 32, 64 mg/ kg) and Ashwagandha (50, 100, 150 mg/kg), Bramhi (20, 40, 80 mg/kg) as test drugs were introduced to the albino rats weighing between 200-250 gm for 2 weeks, 1 hr before electric shock in Learned helplessness test (LHT) and swimming in Forced swimming test (FST). Effects of individual drugs as well as their combination were evaluated. Avoidance response, escape failure and immobility period in case of Imipramine and Ashwagandha showed highly significant (p < 0.01) result on individual use. There was no significant result in case of Bramhi used alone except in escape failure and immobility period (FST), where at higher doses it showed significant (p < 0.01) result. But combination of Bramhi and Ashwagandha in low doses with low dose of Imipramine gave a highly significant result (p < 0.01) in all the parameters. Ashwagandha had significant antidepressant action, but Bramhi had not when used alone. Combination of these two indigenous drug with Imipramine showed high efficacy in animal model.
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Biswas S, Nyman JS, Alvarez J, Chakrabarti A, Ayres A, Sterling J, Edwards J, Rana T, Johnson R, Perrien DS, Lonning S, Shyr Y, Matrisian LM, Mundy GR. Anti-transforming growth factor ß antibody treatment rescues bone loss and prevents breast cancer metastasis to bone. PLoS One 2011; 6:e27090. [PMID: 22096521 PMCID: PMC3214031 DOI: 10.1371/journal.pone.0027090] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 10/10/2011] [Indexed: 11/18/2022] Open
Abstract
Breast cancer often metastasizes to bone causing osteolytic bone resorption which releases active TGFβ. Because TGFβ favors progression of breast cancer metastasis to bone, we hypothesized that treatment using anti-TGFβ antibody may reduce tumor burden and rescue tumor-associated bone loss in metastatic breast cancer. In this study we have tested the efficacy of an anti-TGFβ antibody 1D11 preventing breast cancer bone metastasis. We have used two preclinical breast cancer bone metastasis models, in which either human breast cancer cells or murine mammary tumor cells were injected in host mice via left cardiac ventricle. Using several in vivo, in vitro and ex vivo assays, we have demonstrated that anti-TGFβ antibody treatment have significantly reduced tumor burden in the bone along with a statistically significant threefold reduction in osteolytic lesion number and tenfold reduction in osteolytic lesion area. A decrease in osteoclast numbers (p = 0.027) in vivo and osteoclastogenesis ex vivo were also observed. Most importantly, in tumor-bearing mice, anti-TGFβ treatment resulted in a twofold increase in bone volume (p<0.01). In addition, treatment with anti-TGFβ antibody increased the mineral-to-collagen ratio in vivo, a reflection of improved tissue level properties. Moreover, anti-TGFβ antibody directly increased mineralized matrix formation in calverial osteoblast (p = 0.005), suggesting a direct beneficial role of anti-TGFβ antibody treatment on osteoblasts. Data presented here demonstrate that anti-TGFβ treatment may offer a novel therapeutic option for tumor-induced bone disease and has the dual potential for simultaneously decreasing tumor burden and rescue bone loss in breast cancer to bone metastases. This approach of intervention has the potential to reduce skeletal related events (SREs) in breast cancer survivors.
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Ghosh A, Biswas S, Ghosh T. Preparation and Evaluation of Silymarin β-cyclodextrin Molecular Inclusion Complexes. J Young Pharm 2011; 3:205-10. [PMID: 21897659 PMCID: PMC3159273 DOI: 10.4103/0975-1483.83759] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Silymarin is a hepatoprotective agent, having poor water solubility and oral absorption of about 23 – 47%, leading to low bioavailability of the drug. The aim of the present study is to improve the solubility and dissolution rate and in turn the hepatoprotective activity of the drug, by formulating its inclusion complex with beta (β)-cyclodextrin, using different methods. The phase solubility analysis indicates the formation of 1:1 molar inclusion complex of the drug with beta cyclodextrin. Apparent stability constant for Silymarin (Kc) was 722 K-1 with β-cyclodextrin complex. The inclusion complexes were prepared by four different methods, namely, physical mixing, kneading, co-precipitation, and solvent evaporation. The prepared complexes were characterized using differential scanning colorimetry, scanning electron microscopy, and x-ray diffractometry. The inclusion complex prepared by the co-precipitation methods exhibits an overall best result, with respect to the formulation of sustained release formulations.
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Blevins CJ, Emond MR, Biswas S, Jontes JD. Differential expression, alternative splicing, and adhesive properties of the zebrafish δ1-protocadherins. Neuroscience 2011; 199:523-34. [PMID: 22001682 DOI: 10.1016/j.neuroscience.2011.09.061] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 09/11/2011] [Accepted: 09/22/2011] [Indexed: 12/16/2022]
Abstract
Protocadherins comprise the largest family within the cadherin superfamily of cell surface receptors. Here, we characterize the δ1-protocadherin subfamily during the development of the zebrafish nervous system. In zebrafish, there are five δ1-protocadherins: pcdh1a, pcdh1b, pcdh7a, pcdh7b, andpcdh9. Each protocadherin gene is highly homologous to its human ortholog. While the expression pattern in the developing CNS is similar for each δ1-protocadherin, with labeling observed in all major subdivisions, the detailed patterns are distinct. In addition, we provide evidence for alternative splicing of the pcdh7b and pcdh9 genes, resulting in variation in their respective cytoplasmic domains. As protocadherins are widely regarded to act as cell adhesion molecules, we used in vitro assays of δ1-pcdh ectodomains to directly test their adhesive properties. We found no evidence for calcium-dependent, homophilic adhesion, contrasting sharply with the behavior of classical cadherins.
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Biswas S, Lin S. Logistic Bayesian LASSO for identifying association with rare haplotypes and application to age-related macular degeneration. Biometrics 2011; 68:587-97. [PMID: 21955118 DOI: 10.1111/j.1541-0420.2011.01680.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Rare variants have been heralded as key to uncovering "missing heritability" in complex diseases. These variants can now be genotyped using next-generation sequencing technologies; nonetheless, rare haplotypes may also result from combination of common single nucleotide polymorphisms available from genome-wide association studies (GWAS). The National Eye Institute's data on age-related macular degeneration (AMD) is such an example. Studies on AMD had identified potential rare variants; however, due to lack of appropriate statistical tools, effects of individual rare haplotypes were never studied. Here we develop a method for identifying association with rare haplotypes for case-control design. A logistic regression based retrospective likelihood is formulated and is regularized using logistic Bayesian LASSO (LBL). In particular, we penalize the regression coefficients using appropriate priors to weed out unassociated haplotypes, making it possible for the rare associated ones to stand out. We applied LBL to the AMD data and identified common and rare haplotypes in the complement factor H gene, gaining insights into rare variants' contributions to AMD beyond the current literature. This analysis also demonstrates the richness of GWAS data for mapping rare haplotypes-a potential largely unexplored. Additionally, we conducted simulations to investigate the performance of LBL and compare it with Hapassoc. Our results show that LBL is much more powerful in identifying rare associated haplotypes when the false positive rates for both approaches are kept the same.
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Arun B, Biswas S, Tankhiwale N, Blackford AL, Gutierrez-Barrera AM, Litton JK, Hortobagyi GN, Amos CI, Parmigiani G. Assessing the added value of breast tumor markers in breast cancer genetic risk prediction model BRCAPRO. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.27_suppl.164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
164 Background: BRCAPRO is a widely used genetic risk prediction model for estimating the carrier probabilities of mutations in BRCA1/2 genes. BRCAPRO has been enhanced to utilize information on molecular markers ER, PR, CK5/6, and CK14. However, no independent validation study on the utility of these markers in risk prediction exists to support using these in actual clinical settings. Further, an important predictive and prognostic marker for breast cancer, Her-2/neu (Her2) is not utilized in BRCAPRO. Therefore, the aim of our study was to: 1) incorporate Her2 in BRCAPRO; 2) conduct a validation study of the markers. Methods: Patients with breast cancer at the UT M. D. Anderson Cancer Center’s breast clinic who were referred for genetic evaluation were included. Separate sets of cohort were used for model building with Her2 and validation to avoid bias. This study was approved by the IRB. For the model building, we estimated the joint probabilities of ER and Her2 status for carriers and non-carriers of BRCA1/2 mutations. For the validation, BRCAPRO was run at two settings: 1) no marker data used and 2) ER/PR used. We calculated the Area Under the receiving operator characteristic Curve (AUC) using the probabilities of carrying any of BRCA1 or BRCA2 and conditional probabilities of carrying BRCA1 (CondBRCA1) and BRCA2 (CondBRCA2) given a proband is carrier. Results: The model-building set for Her2 was based on 409 probands and validation set on 796 probands wherein 23% of the probands were carriers. In the model-building step, we found that joint consideration of Her2 and ER/PR is useful in discriminating between carriers and non-carriers in some subgroups, e.g., a proband with ER-, Her2+ is much more likely to be a non-carrier than a carrier. In the validation step, the AUC for CondBRCA1 and CondBRCA2 improved substantially when ER/PR was used. We are in the process of coding Her2 in BRCAPRO and then validating its utility. Conclusions: Breast tumor markers are useful for prediction of BRCA1/2 mutation status in the BRCAPRO model. ER/PR helps discriminate between BRCA1 and BRCA2 mutation carriers. In our ongoing validation study Her2 is expected to improve discrimination between carriers and non-carriers in certain sub-groups.
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Travis EL, Rachakonda G, Zhou X, Korhonen K, Sekhar KR, Biswas S, Freeman ML. NRF2 deficiency reduces life span of mice administered thoracic irradiation. Free Radic Biol Med 2011; 51:1175-83. [PMID: 21712086 PMCID: PMC3156301 DOI: 10.1016/j.freeradbiomed.2011.05.038] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 05/11/2011] [Accepted: 05/27/2011] [Indexed: 12/25/2022]
Abstract
Subsets of cancer survivors who have been subjected to thoracic irradiation face the prospect of developing pulmonary injury. Radiation-induced pulmonary fibrosis is an insidious injury that presents 6 to 24 months after irradiation and continues to progress over a period of years. TGF-β and reactive oxygen species contribute significantly to the pathogenesis of this injury. The transcription factor NRF2 controls antioxidant gene expression and therefore regulates the cellular oxidant burden. This work demonstrates an additional paradigm for NRF2: suppression of TGF-β-mediated signaling, assessed by measuring expression of a surrogate TGF-β1 target gene (PAI-1) in lung fibroblasts. Thoracic irradiation of Nfe2l2(-/-) mice resulted in rapid expression of PAI-1 and FSP-1 compared to irradiated wild-type mice. Examination of lung tissue 16 weeks after thoracic irradiation of Nfe2l2(-/-) mice revealed the presence of distended alveoli and decreased numbers of alveoli compared to wild-type mice. Suppression of NRF2 expression shortened life span in mice administered 16 Gy to the thorax. Nfe2l2(+/-) and Nfe2l2(-/-) mice exhibited a mean life span of 176 days compared to wild-type mice, which lived an average of 212 days. These novel results identify NRF2 as a susceptibility factor for the development of late tissue injury.
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371
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Biswas S, Dodwadkar NS, Sawant RR, Torchilin VP. Development of the novel PEG-PE-based polymer for the reversible attachment of specific ligands to liposomes: synthesis and in vitro characterization. Bioconjug Chem 2011; 22:2005-13. [PMID: 21870873 DOI: 10.1021/bc2002133] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Surface grafting of liposomes with the wide variety of ligands including antibodies and other proteins is a promising approach for targeted delivery of therapeutics. In this paper, we describe a simple method of synthesizing a hydrazine-functionalized poly(ethylene glycol)-phosphatidylethanolamine (PEG-PE)-based amphiphilic polymer which can conjugate a variety of ligands via a reversible, pH-cleavable bond. In this method, the targeting ligand is attached to the distal end of the PEG chain, which facilitates its easy access to the targeted site of interaction. The reversible attachment of targeting ligands is useful especially in multifunctional liposomal systems, whereafter successfully performing the function of targeting to the specific site, the bulky ligands, such as proteins or antibodies, are cleaved off in response to an environmental stimulus to expose some other functionalities such as ligands for intracellular penetration or organelle-specific targeting. To investigate the applicability of the protocol, the model ligands monoclonal antinucleosome antibody 2C5 and antimyosin antibody 2G4, and glycoproteins concanavalin A (Con-A) and avidin were conjugated to the synthesized polymer and incorporated into liposomes. In vitro assays including biochemical, enzyme-linked immunosorbent, fluorescence microscopy, and flow cytometry were used to confirm three key characteristics of the modified and/or liposome-attached proteins: successful conjugation of the targeting ligands to the polymer, preservation of specific activity of the ligands after the conjugation and liposome attachment, and the facile pH-sensitive ligand detachment. Monoclonal antibody 2C5 and 2G4, immobilized on the liposome surface, retained their binding affinity to corresponding antigens as confirmed by ELISA. The Con A-bearing liposomes showed significantly higher agglutination in the presence of its substrate mannan compared to plain liposomes (PL) and avidin-functionalized liposomes bound specifically with biotin-agarose. The study on the pH-dependence showed that almost 80% of the hydrazone bond was cleaved after rather brief preincubation of the immunoliposomes at pH 5 for 0.5 to 1 h. Fluorescence microscopy and flow cytometry analysis of cancer cells (HeLa and MCF-7) treated with cancer cell-specific targeting ligand mAb 2C5-bearing liposomes showed enhanced cellular binding. Studies at low pH clearly confirmed the easy cleavability of the targeting ligand from the liposomes resulting in significantly less or virtually no cellular association.
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372
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Meyur R, Mitra B, Adhikari A, Mitra D, Biswas S, Sadhu A. Attitude of medical students about different teaching aids used in lectures in anatomy. NEPAL MEDICAL COLLEGE JOURNAL : NMCJ 2011; 13:157-159. [PMID: 22808804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Nowadays medical teachers use different audiovisual (AV) aids of teaching in their classes to make the subject more interesting and understandable. To assess the impact of three common lecture delivery methods, viz Blackboard (BB), Transparency and Over Head Projector (OHP) and Powerpoint Presentation (PP), a questionnaire based study was carried out among first year MBBS students of R.G.Kar Medical College, Kolkata. One hundred fouty students of academic session 2010-2011 were exposed to different aids of teaching, viz. Black Board (BB), Over Head Projector (OHP), power point presentation (PP) for ten months. They were taught Anatomy by different teachers who used all the three AV aids in their lectures. Then they were asked to respond to a questionnaire regarding these three AV aids of teaching. The students preferred Black Board teaching over OHP and result was statistically significant (p value < 0.0001). BB teaching was also preferred over PP presentations (p < 0.02). But in comparison to OHP, students preferred PP though the difference is not statistically significant (p < 0.10). Most of the students still prefer Black Board teaching to other modern AV aids like OHP and PP. For better understanding of a subject by students and improvement of their performance, a teacher should match the lectures with preferred AV aids and use the AV aids prudently.
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373
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Biswas S, Pathak PN, Singh DK, Roy SB, Manchanda VK. Mathematical modeling of solvent extraction of uranium from sulphate media employing 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and its mixture with trioctylphosphine oxide (TOPO) as extractants. J Radioanal Nucl Chem 2011. [DOI: 10.1007/s10967-011-1116-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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374
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Kumar P, Medhekar A, Ghadyalpatil NS, Noronha V, Biswas S, Kurkure P, Nair R, Kelkar R, Banavali SD. The effect of age on the bacteria isolated and the antibiotic-sensitivity pattern in infections among cancer patients. Indian J Cancer 2011; 47:391-6. [PMID: 21131751 DOI: 10.4103/0019-509x.73574] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Patients with cancer are predisposed to infections. Antimicrobial patterns and antibiotic sensitivity change with increasing age, making choice of empirical therapy more complicated. MATERIALS AND METHODS This single-center study aims to try and assess the influence of age on microbiology and antibiotic sensitivity of organisms causing infection in patients with malignant disease. RESULTS The five most common bacterial pathogens isolated were Pseudomonas sp (245, 26.2%) > Enterocococcus sp (109, 11.66%) > Staphylococcus aureus (107, 11.44%) > Escherichia coli (106, 11.34%) > Klebsiella sp (99, 10.59%). There was no significant change in the distribution of Gram-positive and Gram-negative bacteria with age. However, there was an increase in the occurrence of the Enterobacteriacea group and a decrease in infections caused by nonlactose fermenters with increasing age. The ESBL production increased from 10.52% (12-19 years) to 24.88% (> 50 years) as did oxacillin resistance (from 14.3% to 28.1%) among S. aureus isolates. The activity of most antimicrobial agents decreased with increasing age. The decreasing trend of activity was statistically significant for meropenam (73.3-41.2%) against Pseudomonas sp. and for the activity of the aminoglycosides for Acinetobacter sp (61.1-17.4% for amikacin). CONCLUSIONS This suggests that empirical antibiotic therapy needs to be changed on the basis of the age of the patient. It also appears that combination therapy is essential for the empirical treatment of infections in elderly patients with cancer.
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Spathis P, Biswas S, Roddaro S, Sorba L, Giazotto F, Beltram F. Hybrid InAs nanowire-vanadium proximity SQUID. NANOTECHNOLOGY 2011; 22:105201. [PMID: 21289399 DOI: 10.1088/0957-4484/22/10/105201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report the fabrication and characterization of superconducting quantum interference devices (SQUIDs) based on InAs nanowires and vanadium superconducting electrodes. These mesoscopic devices are found to be extremely robust against thermal cycling and to operate up to temperatures of ∼ 2.5 K with reduced power dissipation. We show that our geometry allows one to obtain nearly-symmetric devices with very large magnetic field modulation of the critical current. All these properties make these devices attractive for sensitive magnetometry applications and quantum circuit implementation.
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