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Nigam R, Luis AJ, Gagnon AS, Vaz E, Damásio B, Kotha M. Assessing coastal vulnerability at the village level using a robust framework, the example of Canacona in South Goa, India. iScience 2024; 27:109129. [PMID: 38595800 PMCID: PMC11002649 DOI: 10.1016/j.isci.2024.109129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 09/05/2023] [Accepted: 02/01/2024] [Indexed: 04/11/2024] Open
Abstract
Climate change poses a significant threat to coastal regions worldwide. This study presents and applies a modified Coastal Vulnerability Index (CVI) to assess coastal vulnerability at the village level, focusing on Canacona, a taluka in South Goa, India. It adapts the existing CVI methodology by incorporating additional variables to better represent the various dimensions of vulnerability, resulting in 21 variables split into a Physical Vulnerability Index (PVI) and a Social Vulnerability Index (SoVI). The results show spatial variability in coastal vulnerability across the studied villages, with Agonda and Nagercem-Chaudi found to be highly vulnerable and Loliem to be the least vulnerable. A hydrological modeling approach is also used to compare the CVI of every village with their susceptibility to inundation due to rising sea levels. The results demonstrate the influence of local factors on vulnerability, challenging previous taluka-level assessments given the scale upon which adaptation typically takes place.
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Affiliation(s)
- Ritwik Nigam
- School of Earth, Ocean and Atmospheric Sciences (SEAOS), Goa University, Taleigao Plateau, Goa 403206, India
| | - Alvarinho J. Luis
- Division of Polar Remote Sensing, National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Government of India, Headland Sada, Vasco-da-Gama, Goa 403804, India
| | - Alexandre S. Gagnon
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK
| | - Eric Vaz
- Department of Geography & Environmental Studies, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Bruno Damásio
- NOVA Information Management School (NOVA IMS), Universidade Nova de Lisboa, Campus de Campolide, Lisboa, Portugal
| | - Mahender Kotha
- School of Earth, Ocean and Atmospheric Sciences (SEAOS), Goa University, Taleigao Plateau, Goa 403206, India
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Nigam R, Field M, Harris G, Barton M, Carolan M, Metcalfe P, Holloway L. Automated detection, delineation and quantification of whole-body bone metastasis using FDG-PET/CT images. Phys Eng Sci Med 2023; 46:851-863. [PMID: 37126152 DOI: 10.1007/s13246-023-01258-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 04/11/2023] [Indexed: 05/02/2023]
Abstract
Non-small cell lung cancer (NSCLC) patients with the metastatic spread of disease to the bone have high morbidity and mortality. Stereotactic ablative body radiotherapy increases the progression free survival and overall survival of these patients with oligometastases. FDG-PET/CT, a functional imaging technique combining positron emission tomography (PET) with 18 F-fluorodeoxyglucose (FDG) and computer tomography (CT) provides improved staging and identification of treatment response. It is also associated with reduction in size of the radiotherapy tumour volume delineation compared with CT based contouring in radiotherapy, thus allowing for dose escalation to the target volume with lower doses to the surrounding organs at risk. FDG-PET/CT is increasingly being used for the clinical management of NSCLC patients undergoing radiotherapy and has shown high sensitivity and specificity for the detection of bone metastases in these patients. Here, we present a software tool for detection, delineation and quantification of bone metastases using FDG-PET/CT images. The tool extracts standardised uptake values (SUV) from FDG-PET images for auto-segmentation of bone lesions and calculates volume of each lesion and associated mean and maximum SUV. The tool also allows automatic statistical validation of the auto-segmented bone lesions against the manual contours of a radiation oncologist. A retrospective review of FDG-PET/CT scans of more than 30 candidate NSCLC patients was performed and nine patients with one or more metastatic bone lesions were selected for the present study. The SUV threshold prediction model was designed by splitting the cohort of patients into a subset of 'development' and 'validation' cohorts. The development cohort yielded an optimum SUV threshold of 3.0 for automatic detection of bone metastases using FDG-PET/CT images. The validity of the derived optimum SUV threshold on the validation cohort demonstrated that auto-segmented and manually contoured bone lesions showed strong concordance for volume of bone lesion (r = 0.993) and number of detected lesions (r = 0.996). The tool has various applications in radiotherapy, including but not limited to studies determining optimum SUV threshold for accurate and standardised delineation of bone lesions and in scientific studies utilising large patient populations for instance for investigation of the number of metastatic lesions that can be treated safety with an ablative dose of radiotherapy without exceeding the normal tissue toxicity.
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Affiliation(s)
- R Nigam
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, 2522, Australia.
- Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia.
- Illawarra Cancer Care Centre, Wollongong Hospital, Wollongong, NSW, 2500, Australia.
| | - M Field
- Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia
- Liverpool and Macarthur Cancer Therapy Centre, Liverpool, NSW, 2170, Australia
- South Western Sydney Clinical Campus, School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia
| | - G Harris
- Chris O'Brien Lifehouse, Camperdown, NSW, 2050, Australia
| | - M Barton
- Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia
- Liverpool and Macarthur Cancer Therapy Centre, Liverpool, NSW, 2170, Australia
- South Western Sydney Clinical Campus, School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia
| | - M Carolan
- Illawarra Cancer Care Centre, Wollongong Hospital, Wollongong, NSW, 2500, Australia
| | - P Metcalfe
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, 2522, Australia
- Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia
| | - L Holloway
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, 2522, Australia
- Ingham Institute for Applied Medical Research, Liverpool, NSW, 2170, Australia
- Liverpool and Macarthur Cancer Therapy Centre, Liverpool, NSW, 2170, Australia
- South Western Sydney Clinical Campus, School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia
- Institute of Medical Physics, University of Sydney, Camperdown, NSW, 2505, Australia
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Nigam R, Tripathi G, Priya T, Luis AJ, Vaz E, Kumar S, Shakya A, Damásio B, Kotha M. Did Covid-19 lockdown positively affect the urban environment and UN- Sustainable Development Goals? PLoS One 2022; 17:e0274621. [PMID: 36149918 PMCID: PMC9506620 DOI: 10.1371/journal.pone.0274621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 08/23/2022] [Indexed: 11/20/2022] Open
Abstract
This work quantifies the impact of pre-, during- and post-lockdown periods of 2020 and 2019 imposed due to COVID-19, with regards to a set of satellite-based environmental parameters (greenness using Normalized Difference Vegetation and water indices, land surface temperature, night-time light, and energy consumption) in five alpha cities (Kuala Lumpur, Mexico, greater Mumbai, Sao Paulo, Toronto). We have inferenced our results with an extensive questionnaire-based survey of expert opinions about the environment-related UN Sustainable Development Goals (SDGs). Results showed considerable variation due to the lockdown on environment-related SDGs. The growth in the urban environmental variables during lockdown phase 2020 relative to a similar period in 2019 varied from 13.92% for Toronto to 13.76% for greater Mumbai to 21.55% for Kuala Lumpur; it dropped to −10.56% for Mexico and −1.23% for Sao Paulo city. The total lockdown was more effective in revitalizing the urban environment than partial lockdown. Our results also indicated that Greater Mumbai and Toronto, which were under a total lockdown, had observed positive influence on cumulative urban environment. While in other cities (Mexico City, Sao Paulo) where partial lockdown was implemented, cumulative lockdown effects were found to be in deficit for a similar period in 2019, mainly due to partial restrictions on transportation and shopping activities. The only exception was Kuala Lumpur which observed surplus growth while having partial lockdown because the restrictions were only partial during the festival of Ramadan. Cumulatively, COVID-19 lockdown has contributed significantly towards actions to reduce degradation of natural habitat (fulfilling SDG-15, target 15.5), increment in available water content in Sao Paulo urban area(SDG-6, target 6.6), reduction in NTL resulting in reducied per capita energy consumption (SDG–13, target 13.3).
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Affiliation(s)
- Ritwik Nigam
- School of Earth, Ocean and Atmospheric Sciences (SEOAS), Goa University, Taleigao, Goa, India
| | - Gaurav Tripathi
- Department of Geoinformatics, Central University of Jharkhand, Ranchi, Jharkhand, India
| | - Tannu Priya
- Department of Geoinformatics, Central University of Jharkhand, Ranchi, Jharkhand, India
| | - Alvarinho J. Luis
- Polar Remote Sensing Section, National Centre of Polar and Ocean Research, Ministry of Earth Science, Govt. of India, Headland Sada, Goa, India
| | - Eric Vaz
- Department of Geography and Environmental Studies, Ryerson University, Toronto, Ontario, Canada
| | - Shashikant Kumar
- Department of Architecture, Parul University, Limda, Gujarat, India
| | - Achala Shakya
- Department of Computer Engineering, University of Petroleum and Energy Studies, Derhradun, India
| | - Bruno Damásio
- NOVA Information Management School (NOVA IMS), Universidade Nova de Lisboa, Campus de Campolide, Lisboa, Portugal
- * E-mail:
| | - Mahender Kotha
- School of Earth, Ocean and Atmospheric Sciences (SEOAS), Goa University, Taleigao, Goa, India
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Schifano N, Castiglione F, Rewhorn M, Hadway P, Nigam R, Rees R, Alnajjar H, Muneer A. Inguinal lymphadenectomy for penile cancer using a fascial sparing technique -outcomes from a single centre. Eur Urol 2022. [DOI: 10.1016/s0302-2838(22)00767-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Reddy D, Peters M, Shah T, Van Son M, Bertoncelli Tanaka M, Huber P, Lomas D, Rakauskas A, Miah S, Eldred-Evans D, Hosking-Jervis F, Engle R, Dudderidge T, Mccracken S, Greene D, Nigam R, Mccartan N, Valerio M, Orczyk C, Virdi J, Arya M, Ahmed H. Primary focal cryotherapy for non-metastatic prostate cancer: Update from the UK ICE registry. Eur Urol 2022. [DOI: 10.1016/s0302-2838(22)00406-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Nigam R, Luis AJ, Prasad P, Kuttikar S, Yadav R, Vaz E, Kotha M. Spatio-temporal assessment of COVID-19 lockdown impact on beach litter status and composition in Goa, India. Mar Pollut Bull 2022; 174:113293. [PMID: 35090278 DOI: 10.1016/j.marpolbul.2021.113293] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 10/05/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
The study aimed to understand beach litter status at some of the world-famous beaches of Goa, West India, to comprehend the impact of the Covid-19 lockdown. We characterize litter in six categories (Nylon+Rubber, Plastics, Footwear, Glass, Metal, and Thermocol) for eight sampled beaches in the north and south Goa. All beaches show increased glass and decreased plastics (significant litter) during the lockdown period compared to the unlock period that marked the high tourist inflow. Beaches were classified and graded with colour codes using litter density exhibit light blue-green colour coding during the lockdown or unlock period, suggests clean maintenance. The Miramar beach located in the heart of the capital city showed relatively more litter density (yellow code) due to the combination of local people and tourist inflow. Morjim, Palolem, Velsao were littered the least during both periods.
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Affiliation(s)
- Ritwik Nigam
- School of Earth, Ocean and Atmospheric Sciences (SEOAS), Goa University, Goa 403206, India
| | - Alvarinho J Luis
- Polar Remote Sensing Section, National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Government of India, Headland Sada, Vasco-da-Gama, Goa 403804, India
| | - Pankaj Prasad
- School of Earth, Ocean and Atmospheric Sciences (SEOAS), Goa University, Goa 403206, India; Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India
| | - Sachit Kuttikar
- School of Earth, Ocean and Atmospheric Sciences (SEOAS), Goa University, Goa 403206, India
| | - Ramanand Yadav
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India
| | - Eric Vaz
- Department of Geography and Environmental Studies, Ryerson University, Toronto, Canada
| | - Mahender Kotha
- School of Earth, Ocean and Atmospheric Sciences (SEOAS), Goa University, Goa 403206, India.
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Singh DP, Saraswat R, Nigam R. Untangling the effect of organic matter and dissolved oxygen on living benthic foraminifera in the southeastern Arabian Sea. Mar Pollut Bull 2021; 172:112883. [PMID: 34455346 DOI: 10.1016/j.marpolbul.2021.112883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 08/15/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
We studied the relationship between organic carbon in sediments (%Corg), bottom water dissolved oxygen and living benthic foraminifera in a marginal marine upwelling setting from the southeastern Arabian Sea to develop proxy indicator for marine productivity as well as oxygen deficient zones. The surface sediments from 43 stations covering a depth range of 25 to 2980 m were used. The relationship between living benthic foraminifera and ambient environmental parameters (seawater temperature, salinity, dissolved oxygen, organic carbon and Corg/TN and depth) was assessed by multivariate analysis. A majority of the living benthic foraminifera were significantly affected by several ambient parameters. We report that the living benthic foraminiferal assemblage comprising of Epistominella umbonifera, Uvigerina auberiana, Reophax longicollis and Osangularia bengalensis is significantly affected only by %Corg in the sediment. Additionally, we also found that the assemblage including Bolivina obscuranta, Bulimina arabiensis, Bulimina pseudoaffinis and Cancris penangensis is significantly affected only by the bottom water dissolved oxygen. The living benthic foraminifera assemblages can be used to reconstruct marine productivity and dissolved oxygen concentration in the past.
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Affiliation(s)
- D P Singh
- Micropaleontology Laboratory, CSIR-National Institute of Oceanography, Dona Paula 403004, Goa, India; Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee 247667, India.
| | - R Saraswat
- Micropaleontology Laboratory, CSIR-National Institute of Oceanography, Dona Paula 403004, Goa, India
| | - R Nigam
- Micropaleontology Laboratory, CSIR-National Institute of Oceanography, Dona Paula 403004, Goa, India
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Wardak S, Castiglione F, Lindsay J, Alifrangis C, Walkden M, Hadway P, Nigam R, Rees R, Alnajjar H, Muneer A. Management of indeterminate Small Testis Masses (STMs): A 10-year single centre experience. Eur Urol 2021. [DOI: 10.1016/s0302-2838(21)01031-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Pozzi E, Cakir O, Castiglione F, Schifano N, Hadway P, Nigam R, Rees R, Albersen M, Parnham A, Lau M, Alnajjar H, Vijai S, Muneer A. Long term outcomes of Dynamic Sentinel Lymph Node Biopsy (DSNB) for clinically impalpable (cN0) penile cancer patients- an eUROGEN study. Eur Urol 2021. [DOI: 10.1016/s0302-2838(21)01044-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Alnajjar H, Rewhorn M, Castiglione F, Cayetano Alcaraz A, Schifano N, Akers C, Haider A, Freeman A, Hadway P, Nigam R, Rees R, Mitra A, Alifrangis C, Muneer A. Long-term outcomes of Penile Squamous Cell Carcinoma (SCC) patients with sarcomatoid variant compared to non-sarcomatoid group - An eUROGEN study. Eur Urol 2021. [DOI: 10.1016/s0302-2838(21)01059-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Reddy D, Peters M, Shah T, Van Son M, Huber P, Lomas D, Rakauskas A, Miah S, Guillaumier S, Dudderidge T, Hindley R, Emara A, Nigam R, Valerio M, Afzal N, Lewi H, Orczyk C, Ogden C, Persad R, Virdi J, Moore C, Arya M, Winkler M, Emberton M, Ahmed H. Cancer control outcomes following focal therapy using HIFU in 1,829 men with non-metastatic prostate cancer treated over 15 years. Eur Urol 2021. [DOI: 10.1016/s0302-2838(21)01427-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Nigam R, Pandya K, Luis AJ, Sengupta R, Kotha M. Positive effects of COVID-19 lockdown on air quality of industrial cities (Ankleshwar and Vapi) of Western India. Sci Rep 2021; 11:4285. [PMID: 33608603 PMCID: PMC7895933 DOI: 10.1038/s41598-021-83393-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/29/2021] [Indexed: 01/25/2023] Open
Abstract
On January 30, 2020, India recorded its first COVID-19 positive case in Kerala, which was followed by a nationwide lockdown extended in four different phases from 25th March to 31st May, 2020, and an unlock period thereafter. The lockdown has led to colossal economic loss to India; however, it has come as a respite to the environment. Utilizing the air quality index (AQI) data recorded during this adverse time, the present study is undertaken to assess the impact of lockdown on the air quality of Ankleshwar and Vapi, Gujarat, India. The AQI data obtained from the Central Pollution Control Board was assessed for four lockdown phases. We compared air quality data for the unlock phase with a coinciding period in 2019 to determine the changes in pollutant concentrations during the lockdown, analyzing daily AQI data for six pollutants (PM10, PM2.5, CO, NO2, O3, and SO2). A meta-analysis of continuous data was performed to determine the mean and standard deviation of each lockdown phase, and their differences were computed in percentage in comparison to 2019; along with the linear correlation analysis and linear regression analysis to determine the relationship among the air pollutants and their trend for the lockdown days. The results revealed different patterns of gradual to a rapid reduction in most of the pollutant concentrations (PM10, PM2.5, CO, SO2), and an increment in ozone concentration was observed due to a drastic reduction in NO2 by 80.18%. Later, increases in other pollutants were also observed as the restrictions were eased during phase-4 and unlock 1. The comparison between the two cities found that factors like distance from the Arabian coast and different industrial setups played a vital role in different emission trends.
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Affiliation(s)
- Ritwik Nigam
- School of Earth, Ocean and Atmospheric Sciences (SEOAS), Goa University, Taleigao Plateau, Goa, 403206, India
| | - Kanvi Pandya
- Department of Geography, Faculty of Science, The Maharaja Sayajirao University of Baroda, Fatehgunj, Vadodara, 390002, India
| | - Alvarinho J Luis
- Earth System Science Organization-National Centre of Polar and Ocean Research, Ministry of Earth Science, Govt. of India, Headland Sada, Goa, 403804, India
| | - Raja Sengupta
- Department of Geography & McGill School of Environment, McGill University, Montreal, QC, H3A0B9, Canada
| | - Mahender Kotha
- School of Earth, Ocean and Atmospheric Sciences (SEOAS), Goa University, Taleigao Plateau, Goa, 403206, India.
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Pozzi E, Cakir O, Hadway P, Nigam R, Freeman A, Alnajjar H, Muneer A. Predictive factors for local recurrence (LR) and cancer-specific survival (CSS) – an eUROGEN risk stratification for grade 2 and grade 3 tumours. EUR UROL SUPPL 2020. [DOI: 10.1016/s2666-1683(20)32754-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Suokhrie T, Saraswat R, Nigam R. Lack of denitrification causes a difference in benthic foraminifera living in the oxygen deficient zones of the Bay of Bengal and the Arabian Sea. Mar Pollut Bull 2020; 153:110992. [PMID: 32275541 DOI: 10.1016/j.marpolbul.2020.110992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/13/2020] [Accepted: 02/14/2020] [Indexed: 06/11/2023]
Abstract
Despite being located at the same latitudes, the Bay of Bengal oxygen deficient zone (ODZ) is markedly different than the Arabian Sea ODZ. The uptake of oxygen in the Bay of Bengal does not lead to denitrification as in the Arabian Sea. This difference in ODZ of the Bay of Bengal and the Arabian Sea is expected to support different benthic fauna. We report that the living benthic foraminifera in the Bay of Bengal ODZ are markedly different than that in the Arabian Sea ODZ. Only four species (Brizalina spathulata, Eubuliminella exilis, Uvigerina peregrina and Rotaliatinopsis semiinvoluta) dominant in the Bay of Bengal ODZ have also been reported from the Arabian Sea oxygen deficient waters. The difference in living benthic foraminifera dominant in the ODZ of the Bay of Bengal and the Arabian Sea, is attributed to the lack of denitrification and associated processes in the Bay of Bengal.
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Affiliation(s)
- Thejasino Suokhrie
- Oceanography Orientation Division, CSIR-National Institute of Oceanography, Goa, India.
| | - Rajeev Saraswat
- Micropaleontology Laboratory, Geological Oceanography Division, CSIR-National Institute of Oceanography, Goa, India.
| | - R Nigam
- Micropaleontology Laboratory, Geological Oceanography Division, CSIR-National Institute of Oceanography, Goa, India
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Connor MJ, Gorin MA, Ahmed HU, Nigam R. Focal therapy for localized prostate cancer in the era of routine multi-parametric MRI. Prostate Cancer Prostatic Dis 2020; 23:232-243. [PMID: 32051551 DOI: 10.1038/s41391-020-0206-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/16/2020] [Accepted: 01/20/2020] [Indexed: 01/19/2023]
Abstract
BACKGROUND Prostate cancer focal therapy aims to minimize the side-effects of whole gland treatments, such as radical prostatectomy and radiotherapy without compromising oncological efficacy. However, concerns exist regarding the multifocal nature of prostate cancer and the lack of long-term oncological data for this form of treatment. In recent years, the routine adoption of multi-parametric magnetic resonance imaging (mpMRI) of the prostate has improved our ability to select candidates for focal therapy and to accurately deliver this form of prostate cancer treatment. METHODS We performed a review of the literature to provide a summary of the oncological and functional outcomes of men receiving primary prostate focal therapy. Furthermore, we discuss the impact of the routine implementation of mpMRI as part of the initial prostate cancer diagnostic pathway on the selection of candidates and delivery of focal therapy. Finally, we summarize knowledge gaps in the field and highlight active clinical trials in this arena. RESULTS Primary focal therapy involves the application of one of a number of energies that ablate tissue, such as cryotherapy and high intensity focused ultrasound (HIFU). Success is principally dependent on highly accurate patient selection and disease localization underpinned in large part by the routine integration of pre-biopsy mpMRI. Prospective medium-term follow-up data for primary HIFU and cryotherapy for men with intermediate-risk disease have shown acceptable cancer control with low risk of side effects and complications. Additional research is needed to clearly define an appropriate follow-up approach and to guide the management of in- and out-of-field recurrences. Multiple comparative trials with randomization against standard care are currently underway in men with intermediate- and high-risk prostate cancer. CONCLUSION The widespread adoption of prostate mpMRI has led to improved disease localization, enabling the performance of focal therapy as a viable treatment strategy for men with low volume intermediate-risk prostate cancer.
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Affiliation(s)
- M J Connor
- Imperial Prostate, Division of Surgery, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Charing Cross Hospital, London, W6 8RF, UK. .,Imperial Urology, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, W6 8RF, UK.
| | - M A Gorin
- The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - H U Ahmed
- Imperial Prostate, Division of Surgery, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Charing Cross Hospital, London, W6 8RF, UK.,Imperial Urology, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, W6 8RF, UK
| | - R Nigam
- Royal Surrey NHS Foundation Trust, Guildford, Surrey, GU2 7XX, UK.,University College London Hospital, 235 Euston Road, London, NW1 2BU, UK
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Huber P, Afzal N, Arya M, Boxler S, Charman S, Cornaby A, Dudderidge T, Emberton M, Guillaumier S, Hindley R, Leemann L, Lewi H, Mc Cartan N, Moore C, Nigam R, Ogden C, Persad R, Shah K, Thalmann G, Virdi J, Winkler M, Ahmed H. Focal HIFU: Higher recurrence rate in treatment of anterior compared to posterior lesions in prostate cancer. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/s1569-9056(18)31383-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kumari P, Nigam R, Choudhury S, Singh SK, Yadav B, Kumar D, Garg SK. Demodex canis targets TLRs to evade host immunity and induce canine demodicosis. Parasite Immunol 2018; 40. [PMID: 29253318 DOI: 10.1111/pim.12509] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 12/13/2017] [Indexed: 12/31/2022]
Abstract
Widespread incidence of Demodex mites throughout the mammalian class and occasional serious and fatal outcomes in dogs warrant an insight into the host-parasite interface especially. Therefore, this study was aimed to unravel the interplay between innate immune response and canine demodicosis. The dogs diagnosed to have natural clinical demodicosis were allocated into two groups; dogs with localized demodicosis (LD) and with generalized demodicosis (GD). The expression of toll-like receptors (TLRs) 2, 4 and 6 genes in peripheral blood mononuclear cells of these dogs was quantified by real-time PCR. Significantly increased TLR2 gene expression, while significantly diminished TLR4 and TLR6 gene expressions were observed in demodicosed dogs (LD and GD) as compared with the healthy ones. Even the expression of TLR2 gene was found to differ significantly between the dogs with LD and GD. Therefore, it can be inferred that clinical demodicosis in dogs is coupled with an up-regulation of TLR2 and down-regulation of TLR4 and TLR6 gene expressions. Overexpression of TLR2 gene might be responsible for Demodex-induced clinical manifestations, while TLR4 and TLR6 gene down-regulations could be the paramount strategy of Demodex mites to elude the host-immune interface.
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Affiliation(s)
- P Kumari
- College of Biotechnology, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura, India
| | - R Nigam
- College of Biotechnology, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura, India
| | - S Choudhury
- Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura, India
| | - S K Singh
- Department of Veterinary Medicine, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura, India
| | - B Yadav
- Department of Veterinary Physiology, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura, India
| | - D Kumar
- College of Biotechnology, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura, India
| | - S K Garg
- Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, U.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go Anusandhan Sansthan (DUVASU), Mathura, India
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Kranz J, Parnham A, Albersen M, Sahdev V, Ziada M, Nigam R, Muneer A, Steffens J, Malone P. Zentralisierung der Harnröhre und Pseudoglansbildung nach partieller Penektomie. Urologe A 2017; 56:1293-1297. [DOI: 10.1007/s00120-017-0478-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Singhai J, Nigam R, Jain AK. The Demographic Study of Otorhinolaryngological Trauma Among Patients with Head and Neck Trauma and Their Management in a Tertiary Care Centre. Indian J Otolaryngol Head Neck Surg 2017; 70:249-255. [PMID: 29977850 DOI: 10.1007/s12070-017-1132-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 04/05/2017] [Indexed: 11/28/2022] Open
Abstract
The trauma has been increasing in frequency, especially in recent decades because of the higher number of automobile accidents and violence. The ear, nose and face region is the area in the body that is commonly involved in head and neck injury. Trauma to this region is often associated with mortality and varying degree of physical, functional and psychological damage. To study the demography, aetiology, clinical presentation, outcome of ENT trauma in our tertiary care centre and to compare our study with previous studies to see the changing trends with passage of time. A prospective study was conducted on 200 head and neck patients with ENT injuries during a period of 1 year from July 2014 to July 2015, who were admitted in ENT Department and Trauma Centre of Gajra Raja Medical College and J.A. Group of Hospital, Gwalior. Most of the patients were young adult males of age group 18-40 years (45, 22.5%) with a male:female ratio 1.78:1. Among them 53% patients were from rural area while 47% were from urban area. RTA is the most prevalent cause of ENT trauma (37%), followed by interpersonal violence (25%). 27% of the patients had facial injury and multiple region injury each. Among 200 patients 33% were managed conservatively on the other hand 66% patients required surgical interventions. Mortality rate was 8%. Among all 184 survivors 25.5% suffered from hearing loss, 14.5% had tympanic membrane perforation with hearing loss, 12% had pinna disfigurement, 10% had change in voice, 6.5% had permanent nasal deformity, 2% had facial nerve palsy. Young male adults were the most prevalent victims of ENT trauma, and Road traffic accidents were responsible for majority of the ENT injuries. Screening of all the patients with head and neck injuries for the presence of trauma in the ENT region should be introduced to enable early detection and therefore prevention of complications.
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Affiliation(s)
- J Singhai
- Department of ENT, Gajra Raja Medical College and JA Group of Hospitals, Gwalior, M.P. India.,Room No 22, Senior Girls Hostel, JAH Campus, Gwalior, M.P. India
| | - R Nigam
- Department of ENT, Gajra Raja Medical College and JA Group of Hospitals, Gwalior, M.P. India
| | - A K Jain
- Department of ENT, Gajra Raja Medical College and JA Group of Hospitals, Gwalior, M.P. India
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M A, Parnham A, Sandev V, Christodoulidou M, Akers C, Freeman A, Nigam R, Minhas S, Malone P, Muneer A. 172 Predicting Local Recurrence (LR) Following Glansectomy Combined With A Split-Thickness Skin Graft in Patients With Penile Squamous Cell Carcinoma. J Sex Med 2017. [DOI: 10.1016/j.jsxm.2016.11.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Nigam R, Dubey R, Saraswat R, Sundaresh, Gaur AS, Loveson VJ. Ancient Indians (Harappan Settlement) were Aware of Tsunami/Storm Protection Measures:A New Interpretation of Thick Walls at Dholavira, Gujarat, India. CURR SCI INDIA 2016. [DOI: 10.18520/cs/v111/i12/2040-2043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Kum F, Jones A, Nigam R. 780. Factors affecting urinary retention after transperineal template biopsy of the prostate. Eur J Surg Oncol 2016. [DOI: 10.1016/j.ejso.2016.06.382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Sharma L, Pandey V, Nigam R, Saxena A, Swain DK, Yadav B. Association of oxidative status and semen characteristics with seminal plasma proteins of buffalo semen. Iran J Vet Res 2016; 17:226-230. [PMID: 28224004 PMCID: PMC5309452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
To study the influence of season on oxidative status of buffalo semen and their association with semen characteristics and seminal plasma proteins, ejaculates were collected twice a week in winter, summer and rainy seasons from six adult Bhadawari buffalo bulls. The neat semen was analyzed for semen characteristics immediately after collection and oxidative status viz. lipid peroxidation (LPO), catalase (CAT), super oxide dismutase (SOD) activity, and total protein (TP) were estimated in seminal plasma. The protein profiling was carried out by one-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The significant effect of season was observed on TP, SOD activity and % protein fractions of seminal plasma proteins of buffalo bulls. The TP values showed positive correlation with ejaculate volume (EV), sperm concentration (SC), and % live-dead (LD) and negative correlation with progressive motility (PM), and hypo-osmotic swelling test (HOST). The SOD activity showed positive correlation with PM, LD, HOST and % acrosoamal integrity (AI). Besides that, results showed correlation of TP with 6.5, 38 and 66 kDa proteins, LPO with 70, 72, 84 and 86 kDa proteins, CAT with 70 kDa and 86 kDa proteins, and SOD with 6.5, 24.5, 44.5, 70 and 72 kDa proteins. In conclusion, this study indicated that TP and SOD activity of seminal plasma of buffalo bulls were influenced by season and were found to be associated with some of the semen characteristics and expression of seminal plasma proteins.
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Affiliation(s)
- L. Sharma
- Department of Veterinary Biochemistry, College of Veterinary Science and Animal Husbandry, Veterinary University, Mathura, 281001, India;
| | - V. Pandey
- Department of Veterinary Biochemistry, College of Veterinary Science and Animal Husbandry, Veterinary University, Mathura, 281001, India; ,Correspondence: V. Pandey, Department of Veterinary Biochemistry, College of Veterinary Science and Animal Husbandry, Veterinary University, Mathura, 281001, India. E-mail:
| | - R. Nigam
- Department of Veterinary Biochemistry, College of Veterinary Science and Animal Husbandry, Veterinary University, Mathura, 281001, India;
| | - A. Saxena
- Department of Veterinary Obstetrics and Gynecology, College of Veterinary Science and Animal Husbandry, Veterinary University, Mathura, 281001, India;
| | - D. K. Swain
- Department of Veterinary Physiology, College of Veterinary Science and Animal Husbandry, Veterinary University, Mathura, 281001, India
| | - B. Yadav
- Department of Veterinary Physiology, College of Veterinary Science and Animal Husbandry, Veterinary University, Mathura, 281001, India
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Nigam R, Srivastava MM. Effects of carboxylic and amino acids on Cd uptake byLycopersicum esculentum. Chemical Speciation & Bioavailability 2015. [DOI: 10.3184/095422905782774973] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Sharma L, Pandey V, Nigam R, Singh P, Saxena A, Swain DK. Seasonal Variations in Seminal Plasma Proteins of Buffalo. Reprod Domest Anim 2014; 49:387-91. [DOI: 10.1111/rda.12285] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 01/02/2014] [Indexed: 11/29/2022]
Affiliation(s)
- L Sharma
- Department of Biochemistry; College of Veterinary Science and Animal Husbandry; UP Pandit Deen Dayal Upadhyaya Pashu-Chikitsa Vigyan Vishwavidyalya evam Go Anusandhan Sansthan (DUVASU); Mathura Uttar Pradesh India
| | - V Pandey
- Department of Biochemistry; College of Veterinary Science and Animal Husbandry; UP Pandit Deen Dayal Upadhyaya Pashu-Chikitsa Vigyan Vishwavidyalya evam Go Anusandhan Sansthan (DUVASU); Mathura Uttar Pradesh India
| | - R Nigam
- Department of Biochemistry; College of Veterinary Science and Animal Husbandry; UP Pandit Deen Dayal Upadhyaya Pashu-Chikitsa Vigyan Vishwavidyalya evam Go Anusandhan Sansthan (DUVASU); Mathura Uttar Pradesh India
| | - P Singh
- Department of Biochemistry; College of Veterinary Science and Animal Husbandry; UP Pandit Deen Dayal Upadhyaya Pashu-Chikitsa Vigyan Vishwavidyalya evam Go Anusandhan Sansthan (DUVASU); Mathura Uttar Pradesh India
| | - A Saxena
- Department of Veterinary Gynaecology and Obstetrics; College of Veterinary Science and Animal Husbandry; UP Pandit Deen Dayal Upadhyaya Pashu-Chikitsa Vigyan Vishwavidyalya evam Go Anusandhan Sansthan (DUVASU); Mathura Uttar Pradesh India
| | - DK Swain
- Department of Veterinary Physiology; College of Veterinary Science and Animal Husbandry; UP Pandit Deen Dayal Upadhyaya Pashu-Chikitsa Vigyan Vishwavidyalya evam Go Anusandhan Sansthan (DUVASU); Mathura Uttar Pradesh India
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Price KJ, Cardenas-Turanzas M, Lin H, Roden L, Nigam R, Nates JL. Prognostic indicators of mortality of mechanically ventilated patients with acute leukemia in a comprehensive cancer center. Minerva Anestesiol 2013; 79:147-155. [PMID: 23032926 PMCID: PMC3935771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND The prognosis for adult acute leukemia patients that require intensive care unit (ICU) admission and invasive mechanical ventilation is poor. We aimed to identify prognostic indicators of 30-day hospital mortality in adult patients who had acute leukemia and respiratory failure, who had received invasive mechanical ventilation in the ICU but who had not received blood and marrow transplantation, were not admitted due to cardiopulmonary arrest or myocardial infarction and, had not recently undergone surgery. METHODS In this case-control study, we retrospectively reviewed the medical records of relevant patients >16 year old who had been admitted to the ICU at our institution over a 4-year period. The main outcome measure was 30-day hospital mortality. Univariate and multivariate analyses were conducted to determine significant predictors of death. RESULTS For the 167 patients meeting our eligibility criteria, the median age was 61 years. The majority was admitted due to respiratory insufficiency/failure (69%). The 30-day hospital mortality rate was 62%. Independent predictors of 30-day hospital mortality were advanced disease status (odds ratio [OR]=3.34; 95% confidence interval [CI], 1.65-6.77) and increased organ failure at the time of intubation (OR=1.17; 95% CI, 1.03-1.33) per point increase in the SOFA score. Patients who had received endotracheal intubation within the first 24 h of ICU admission were less likely than others to die (OR=0.46, 95% CI, 0.23-0.91) within the next 30 days after admission to the hospital. CONCLUSION Advanced disease status and elevated SOFA scores at intubation are strong predictors of 30-day mortality in patients with acute leukemia and respiratory failure. The protective effect of early endotracheal intubation warrants further investigation.
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Affiliation(s)
- K J Price
- Department of Critical Care, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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Nigam R, Pan AV, Dou SX. Magnetic phase diagrams based on static and dynamic magnetic behaviour in Ru-based superconducting ferromagnets. J Phys Condens Matter 2011; 23:435702. [PMID: 21997196 DOI: 10.1088/0953-8984/23/43/435702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this work, we present magnetic phase diagrams of a RuSr(2)Eu(1.5)Ce(0.5)Cu(2)O(10-δ) (Ru-1222) superconducting ferromagnet derived from its static and dynamic magnetic responses, measured by temperature and field dependences of dc magnetization and nonlinear ac susceptibility in both low and high magnetic fields. Comparison of magnetic phase diagrams of phase pure and impure samples singles out the intrinsic and extrinsic magnetic features, naturally proposing a unified model of Ru-1222 magnetic behaviour. The results considered within the proposed interpretation indicate full agreement between static and dynamic properties which, if measured in combination, effectively complement each other, uncovering existing ambiguities.
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Affiliation(s)
- R Nigam
- Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, New South Wales, Australia.
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Berinstein NL, Morse M, Kaufman H, Nemunaitis JJ, Odunsi K, Chatta GS, Weir G, MacDonald L, Stanford M, Karkada M, Nigam R, Mansour M. A phase I study of the safety and immunogenicity of a therapeutic vaccine, DPX-0907 in patients with advanced-stage ovarian, breast, or prostate cancer. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.e13050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Barua J, Campbell I I, Cole O, Harris D, Kaisary A, Larner T, Miller P, Nigam R, Mumtaz F, Thilagarajah R, Thompson A, Brown S. High-intensity focused ultrasound for localized prostate cancer: initial experience with a 2-year follow-up. BJU Int 2010; 104:1794; author eply 1794-5. [PMID: 20053194 DOI: 10.1111/j.1464-410x.2009.09065_1.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Nigam R, Linshy VN, Kurtarkar SR, Saraswat R. Effects of sudden stress due to heavy metal mercury on benthic foraminifer Rosalina leei: laboratory culture experiment. Mar Pollut Bull 2009; 59:362-368. [PMID: 19748104 DOI: 10.1016/j.marpolbul.2009.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Laboratory culture experiments were carried out to understand the response of benthic foraminifer Rosalina leei to gradual as well as sudden addition of heavy metal mercury into the media. When mercury was added suddenly, specimens did not show any change in morphology during the initial 40 days. However, later on, out of all the specimens subjected to mercury concentrations up to 150 ng/l, 75% developed deformities, whereas all the specimens subjected to 150-275 ng/l Hg concentrations, had deformed chambers. All specimens kept at 300 ng/l Hg concentration died within 20 days. In addition to this, irregularities were also observed in the rate of reproduction, number of juveniles produced and the survival rate of the juveniles. Where as in an earlier experiment where Hg concentration was increased gradually, irregularities in the newly added chambers were noticed only in case of specimens subjected to very high (180 ng/l) Hg concentration. However, during this experiment, growth was found to be inversely proportional to the mercury concentration.
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Affiliation(s)
- R Nigam
- National Institute of Oceanography, Dona Paula, Goa 403 004, India.
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Abstract
Networks of reactions inside the cell are constrained by the laws of mass and energy balance. The second law of thermodynamics further constrains the topology of the metabolic network, by disallowing interactions that can sustain themselves when they are isolated from the rest of the network. We present an algorithm that identifies such subnetworks and makes them feasible by deleting reactions. This perturbs the network topology, but preserves the optimality of the mass balance solutions. This method has been applied to a full network of Escherichia coli.
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Affiliation(s)
- R Nigam
- W.W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085, USA.
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Abstract
In view of the extensive use of foraminifers for the pollution monitoring especially their unmatched utility in deciphering the temporal variation in the type and concentration of pollutants at a given location, the literature dealing with the application of foraminifers for pollution studies has been reviewed. The pollution monitoring through foraminifers started with attribution of peculiar foraminiferal features at any location to the circumstantial presence of pollutants at that site. These peculiar features of the foraminifers in polluted areas included, variation in the abundance of total, calcareous and agglutinated foraminifers, species diversity, abnormal tests, etc. The abnormalities of tests included stunted growth, abraded margins, dissolved ornamentations, etc. Initially, much attention was paid to the effects of sewage pollution on the foraminifers but later on all kinds of human induced as well as natural pollutants came under the preview of foraminiferologists working on pollution aspects. The advantage of application of foraminifers, over other chemical and biological techniques, for pollution monitoring lies in their potentiality to decipher temporal variation in type and concentration of pollutants at any site even in the absence of pre-pollution studies, based on the recovery of foraminifers from the sediment core samples. Realizing the potential application of characteristic foraminiferal features from the polluted areas to decipher the variation in introduction and concentration of pollutants at any given location with time, efforts were made to characterize the specific types of foraminiferal features to the specific pollutants. It was at this point that the need of culture studies was widely felt which resulted in numerous lab and field culture studies where foraminifers were subjected to specific pollutants in order to document their response to these pollutants and to develop effective foraminiferal proxies for pollution monitoring through time. Such studies are still going on and it is felt that culture studies need to be supplemented with advanced crystallographic and molecular studies in order to find the mechanism through which foraminifers respond to the pollutants.
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Affiliation(s)
- R Nigam
- Micropaleontology Laboratory, Geological Oceanography Division, National Institute of Oceanography, Dona Paula-403 004, Goa, India.
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Affiliation(s)
- R Nigam
- King George's Hospital, Lucknow, India
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Panchang R, Nigam R, Baig N, Nayak G. A foraminiferal testimony for the reduced adverse effects of mining in Zuari Estuary, Goa. ACTA ACUST UNITED AC 2005. [DOI: 10.1080/00207230500241801] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Nigam R, Liang S. A pivoting algorithm for metabolic networks in the presence of thermodynamic constraints. Proc IEEE Comput Syst Bioinform Conf 2005:259-67. [PMID: 16447983 DOI: 10.1109/csb.2005.6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A linear programming algorithm is presented to constructively compute thermodynamically feasible fluxes and change in chemical potentials of reactions for a metabolic network. It is based on physical laws of mass conservation and the second law of thermodynamics that all chemical reactions should satisfy. As a demonstration, the algorithm has been applied to the core metabolic pathway of E. coli.
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Affiliation(s)
- R Nigam
- W.W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085, USA.
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Abstract
The effects of auditory stimuli in the form of synthetic speech output on the learning of graphic symbols were evaluated. Three adults with severe to profound mental retardation and communication impairments were taught to point to lexigrams when presented with words under two conditions. In the first condition, participants used a voice output communication aid to receive synthetic speech as antecedent and consequent stimuli. In the second condition, with a nonelectronic communications board, participants did not receive synthetic speech. A parallel treatments design was used to evaluate the effects of the synthetic speech output as an added component of the augmentative and alternative communication system. The 3 participants reached criterion when not provided with the auditory stimuli. Although 2 participants also reached criterion when not provided with the auditory stimuli, the addition of auditory stimuli resulted in more efficient learning and a decreased error rate. Maintenance results, however, indicated no differences between conditions. Finding suggest that auditory stimuli in the form of synthetic speech contribute to the efficient acquisition of graphic communication symbols.
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Affiliation(s)
- R W Schlosser
- Division of Rehabilitation Sciences, University of Oklahoma Health Sciences Center, USA
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Saraswat R, Kurtarkar SR, Mazumder A, Nigam R. Foraminifers as indicators of marine pollution: a culture experiment with Rosalina leei. Mar Pollut Bull 2004; 48:91-96. [PMID: 14725879 DOI: 10.1016/s0025-326x(03)00330-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In order to develop a viable foraminiferal proxy for heavy metal pollutants, juvenile specimens of Rosalina leei were subjected to different mercury concentrations (0-180 ng/l). Initially considerable growth was observed in specimens kept in saline water having a mercury concentration up to 100 ng/l. But with the gradual increase in concentration of mercury the growth rate started decreasing. Total growth achieved was significantly lower in case of specimens kept at relatively higher mercury concentrations then those maintained in normal saline water. The most significant result of this experiment was the addition of abnormal chambers in the specimens kept at higher mercury concentration. Later the specimens kept at highest concentration (180 ng/l) were subjected to progressively increasing concentration of mercury to see the further effects and it was found that the specimens were still living at as high a mercury concentration as 260 ng/l although there was no growth.
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Affiliation(s)
- R Saraswat
- National Institute of Oceanography, Dona Paula, 403 004 Goa, India.
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Abstract
OBJECTIVE The prevalence of antibodies in different organ-specific autoimmune diseases can vary depending on the racial group studied. Data on the prevalence of antibodies against steroidogenic enzymes in Addison's disease is available only for white Caucasians. We have evaluated the frequency of antibodies against adrenal cytoplasm, 21-hydroxylase, 17-alpha-hydroxylase and side-chain cleavage enzyme in a cohort of Indian patients with Addison's disease of idiopathic and granulomatous aetiology. DESIGN Study of all patients with Addison's disease on whom serum samples were available (84% of total), presenting to the Endocrinology Department in a teaching hospital in India, between 1990 and 1999. PATIENTS Thirty-eight patients with Addison's disease (19 idiopathic, 19 granulomatous). METHODS A radiobinding assay using in vitro transcribed and translated recombinant human 35S-labelled 21-hydroxylase, 17-alpha-hydroxylase and side-chain cleavage enzymes was utilized to detect the respective antibodies. Adrenal cytoplasmic antibodies were measured by indirect immunofluorescence on cryostatic sections of human adrenal cortex. RESULTS Of the 19 patients with idiopathic Addison's disease, adrenal cytoplasmic antibodies were present in five (26%) patients, while 21-hydroxylase antibodies were present in four (21%) subjects. The frequency of 21-hydroxylase antibodies was similar among patients with isolated idiopathic Addison's disease (3/13, 23%), and those associated with other organ-specific autoimmune diseases (1/6, 17%). 17-alpha-hydroxylase and side-chain cleavage antibodies were present in four (21%) and three (16%) patients, respectively. Overall, at least one of the three antibodies was present in eight (42%) subjects. All four female patients with premature ovarian failure had antibodies against 17-alpha-hydroxylase and/or side-chain cleavage enzyme. Two (11%) patients with granulomatous Addison's disease had adrenal antibodies. Of these, one patient with enlarged and calcified adrenal gland secondary to tuberculosis had a high titre of antibodies against all three steroidogenic enzymes. CONCLUSIONS Antibodies to 21-hydroxylase enzyme are less frequent in idiopathic Addison's disease in north Indians, when compared with other Caucasians. In contrast, the prevalence of 17-alpha-hydroxylase and side-chain cleavage enzyme antibodies is similar to those reported. High titre antibodies against steroidogenic enzymes may occasionally be present in patients with clinical evidence of tuberculous Addison's disease.
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Affiliation(s)
- R Nigam
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Nigam R, Bhatia E. Cortisol levels following therapy in tuberculous Addison's disease: results of long term follow up. Natl Med J India 2002; 15:299. [PMID: 12502150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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Chengappa KN, Kambhampati RK, Perkins K, Nigam R, Anderson T, Brar JS, Vemulapalli HK, Atzert R, Key P, Kang JS, Levine J. Bupropion sustained release as a smoking cessation treatment in remitted depressed patients maintained on treatment with selective serotonin reuptake inhibitor antidepressants. J Clin Psychiatry 2001; 62:503-8. [PMID: 11488359 DOI: 10.4088/jcp.v62n07a01] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Patients with depressive disorders smoke tobacco more often than the population at large and find quitting more difficult. Furthermore, when they quit smoking, they are more likely to suffer a relapse of depression. We evaluated the addition of bupropion sustained release (SR) for smoking cessation among patients with a history of depressive disorders being maintained in a euthymic state with selective serotonin reuptake inhibitor (SSRI) antidepressants. METHOD Twenty-five adults with DSM-IV major depressive disorder or depressive disorder NOS currently receiving SSRI maintenance treatment and smoking > or = 15 cigarettes per day participated in the 9-week study. Bupropion SR, 150 mg/day, was added to SSRI treatment and increased to 300 mg/day. Subjects were counseled on smoking cessation measures and chose a target quit date 2 or 4 weeks after the initiation of bupropion SR. Self-reported smoking status, expired carbon monoxide (CO) measurements, Hamilton Rating Scales for Depression and Anxiety scores, and weight were measured at each visit. Subjects were abstinent if they reported not smoking during the prior 7 days, confirmed with an expired-air CO value of < or = 10 ppm. RESULTS Eight (32%) of 25 subjects were abstinent after 9 weeks. At 3-month follow-up, 3 subjects remained abstinent, 3 relapsed, and 2 were lost to follow-up. Eleven subjects (44%) were nonresponders, and 6 (24%) dropped out prior to 3 weeks of treatment due to side effects (N = 3) or were lost to follow-up (N = 3). Mean weight gain was approximately 0.5 lb (0.2 kg) for those completing 9 weeks of bupropion SR treatment. During the 9-week study and the 3-month follow-up, there was no evidence of emergent depression in any subject. Four subjects (16%) spontaneously reported an improvement in SSRI-associated sexual dysfunction. CONCLUSION These open data suggest modest effectiveness for and the safety of bupropion SR as a smoking cessation agent in individuals with depression maintained on treatment with SSRIs. Minimal weight gain, lack of emergent depressive episodes, and improvement of SSRI-associated sexual dysfunction are added advantages.
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Affiliation(s)
- K N Chengappa
- Western Psychiatric Institute and Clinic, University of Pittsburgh, Mayview State Hospital, PA 15213, USA.
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Sachdewa A, Nigam R, Khemani LD. Hypoglycemic effect of Hibiscus rosa sinensis L. leaf extract in glucose and streptozotocin induced hyperglycemic rats. Indian J Exp Biol 2001; 39:284-6. [PMID: 11495291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Investigations were carried out to evaluate the effect of aqueous extract of H. rosa sinensis leaves on blood glucose level and glucose tolerance using Wistar rats. Repeated administration of the extract (once a day for seven consecutive days), at an oral dose equivalent to 250 mg kg(-1), significantly improved glucose tolerance in rats. The peak blood glucose level was obtained at 30 min of glucose load (2 g kg(-1)), thereafter a decreasing trend was recorded up to 120 min. The data exhibit that repeated ingestion of the reference drug tolbutamide, a sulphonylurea and the extract brings about 2-3 fold decrease in blood glucose concentration as compared to single oral treatment. The results clearly indicate that tolbutamide improves the glucose tolerance by 91% and extract does so only by 47%. At 250 mg kg(-1), the efficacy of the extract was 51.5% of tolbutamide (100mg kg(-1)). In streptozotocin diabetic rats, no significant effect was observed with the extract, while glibenclamide significantly lowered the glucose level up to 7 hr. These data suggest that hypoglycemic activity of H. rosa sinensis leaf extract is comparable to tolbutamide and not to glibenclamide treatment.
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Affiliation(s)
- A Sachdewa
- Department of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Agra, India
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Adachi R, Nigam R, Tuvim MJ, DeMayo F, Dickey BF. Genomic organization, chromosomal localization, and expression of the murine RAB3D gene. Biochem Biophys Res Commun 2000; 273:877-83. [PMID: 10891340 DOI: 10.1006/bbrc.2000.3032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Rab proteins, members of the Ras superfamily of small GTPases, play regulatory roles in intercompartmental vesicular transport. Each step of traffic seems to require the participation of at least one distinct Rab, with the Rab3 subfamily involved in stimulated exocytosis. We report our studies on the murine rab3D gene, one of the four mammalian Rab3 isoforms. We located this gene on chromosome 13, region A(2-3). The rab3D gene consists of 5 exons spanning 10.6 kb, and the structural gene is contained in exons 2 through 5 with one canonical GTP-binding motif in each exon. Organization of the rab3D gene is identical to that of rab3A but different from other rab genes. Alternative poly-A(+) signals in the 3' untranslated region account for the identities of multiple transcripts detected by Northern blot analysis. Rab3D is expressed in all tissues studied, predominantly in heart, lung, and liver, and binding sites for multiple transcription factors are found in the TATA-less promoter region.
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Affiliation(s)
- R Adachi
- Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.
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Georgobiani D, Kosovichev AG, Nigam R, Nordlund Å, Stein RF. Numerical Simulations of Oscillation Modes of the Solar Convection Zone. Astrophys J 2000; 530:L139-L142. [PMID: 10655183 DOI: 10.1086/312490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We use the three-dimensional hydrodynamic code of Stein & Nordlund to realistically simulate the upper layers of the solar convection zone in order to study physical characteristics of solar oscillations. Our first result is that the properties of oscillation modes in the simulation closely match the observed properties. Recent observations from the Solar and Heliospheric Observatory (SOHO)/Michelson Doppler Imager (MDI) and Global Oscillations Network Group have confirmed the asymmetry of solar oscillation line profiles, initially discovered by Duvall et al. In this Letter, we compare the line profiles in the power spectra of the Doppler velocity and continuum intensity oscillations from the SOHO/MDI observations with the simulation. We also compare the phase differences between the velocity and intensity data. We have found that the simulated line profiles are asymmetric and have the same asymmetry reversal between velocity and intensity as observed. The phase difference between the velocity and intensity signals is negative at low frequencies, and phase jumps in the vicinity of modes are also observed. Thus, our numerical model reproduces the basic observed properties of solar oscillations and allows us to study the physical properties which are not observed.
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Marcelli M, Ittmann M, Mariani S, Sutherland R, Nigam R, Murthy L, Zhao Y, DiConcini D, Puxeddu E, Esen A, Eastham J, Weigel NL, Lamb DJ. Androgen receptor mutations in prostate cancer. Cancer Res 2000; 60:944-9. [PMID: 10706109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
We analyzed the frequency and relevance of mutations in the coding region of the androgen receptor (AR) in genomic DNA extracted from 137 specimens of prostate cancer. The specimens were obtained from the primary tumors of patients affected by stage B disease [15 nonmicrodissected (group 1A) and 84 microdissected (group 1B)] and from the metastatic deposits of individuals with stage D1 disease [8 nonmicrodissected (group 2A) and 30 microdissected (group 2B)] who had not undergone androgen ablation therapy. The study was conducted by PCR-single strand conformational polymorphism (SSCP) analysis of exons 2-8 in the four groups and direct sequence analysis of exon 1 in group 1B. As positive and negative controls, we used genomic DNA extracted from genital skin fibroblasts of patients affected by various forms of androgen resistance with known mutations in the AR. To control for genetic instability, PCR-SSCP analysis of exon 2 of the human progesterone receptor was carried out on each specimen. The overall number of mutations detected was 11 (8%). No mutations were detected in any of the 99 patients with stage B disease. Eleven mutations were detected in exons 2-8 in 8 of the 38 patients with stage D1 disease (all in group 2B). Simultaneous analysis of exon 2 of the progesterone receptor was carried out, and no SSCP changes were identified. These data suggest that AR mutations are rare and presumably do not play a role in the initial phase of prostatic carcinogenesis. The presence of a significant number of AR mutations in metastatic disease indicates that mutations of this molecule may play a role in the most advanced phases of the natural history of this disease, either by facilitating growth or acquisition of the metastatic phenotype.
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Affiliation(s)
- M Marcelli
- Department of Medicine, Baylor College of Medicine, and Veterans Affairs Medical Center, Houston, Texas 77030, USA.
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Srivastava S, Nigam R, Prakash S, Srivastava MM. Mobilization of trivalent chromium in presence of organic acids: a hydroponic study of wheat plant (Triticum vulgare). Bull Environ Contam Toxicol 1999; 63:524-530. [PMID: 10501732 DOI: 10.1007/s001289901012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- S Srivastava
- Department of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Dayalbagh, Agra-282 005, India
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Nigam R, Triggle CR, Jin JP. h1- and h2-calponins are not essential for norepinephrine- or sodium fluoride-induced contraction of rat aortic smooth muscle. J Muscle Res Cell Motil 1998; 19:695-703. [PMID: 9742453 DOI: 10.1023/a:1005389300151] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To investigate the controversial issue concerning the role of calponin in smooth muscle contraction, this study examined the relationship between smooth muscle calponin and the contraction of aortic rings from different strains of rats: Sprague-Dawley (SD), Wistar, and Wistar Kyoto (WKY). Western blot analysis demonstrated that h1- and h2-calponins are present in aortic smooth muscle from adult SD rats but not Wistar or WKY rats. Nevertheless, h1-calponin is detectable in stomach from Wistar rats, although at a much lower level compared with that in the SD rat stomach. This suggests that a repressed expression of the gene, instead of a simple null mutation, may have caused its absence from the aortic smooth muscle. Despite the presence or absence of calponin, the aortic smooth muscles from the different strains of rats all develop contractions in response to the physiological agonist norepinephrine (NE) and following activation with the plasma membrane receptor-independent NaF induction. The data indicate that h1- and h2-calponins are not essential for NE- and NaF-induced contractions in aortic smooth muscle. The calponin-positive adult SD rat aorta was found to be more sensitive in contractile response to NE and NaF inductions compared with the calponin-negative rat aortae. This may imply a potential modulator function of calponin in the contraction of smooth muscle, whereas other contractile protein isoform differences between these rat strains may also play a role.
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Affiliation(s)
- R Nigam
- Department of Biochemistry & Molecular Biology, University of Calgary Faculty of Medicine, Alberta, Canada
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Nigam R, Anderson DJ, Lee SF, Bennett BM. Isoform-specific biotransformation of glyceryl trinitrate by rat aortic glutathione S-transferases. J Pharmacol Exp Ther 1996; 279:1527-34. [PMID: 8968379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The objective of this study was to purify and characterize rat aortic glutathione S-transferases (GSTs) and to assess their role in the biotransformation of the nitrovasodilator, glyceryl trinitrate (GTN). Two class alpha GSTs (Ya and Yc) a class mu GST (Yb2) and a class pi GST (Yp) were identified in rat aortic cytosol. Partial purification of three of these (Yb2, Yc and Yp) was achieved by affinity chromatography with S-hexylglutathione agarose. Further purification by cation- and anion-exchange chromatography resulted in the purification of GST Yc and GST Yb2/Yp to apparent homogeneity, a purification of 200- and 110-fold, respectively. Purified GST Yc and Yb2/Yp mediated GTN biotransformation with similar rates. GST activity and GTN biotransformation by rat aortic cytosol and affinity-purified GSTs were highly sensitive to inhibition by the class mu selective inhibitors Basilen Blue and bromosulfophthalein. Removal of GST Yb2 from rat aortic cytosol by immunoprecipitation resulted in marked inhibition of GST activity and GTN biotransformation. We conclude that the GSTs account for the major portion of GTN biotransformation in rat aortic cytosol, and that this is primarily attributable to the GST Yb2 isoform.
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Affiliation(s)
- R Nigam
- Department of Pharmacology and Toxicology, Faculty of Medicine, Queen's University, Kingston, Ontario, Canada
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Abstract
The organic nitrates are interesting examples of drugs that undergo biotransformation at their site of action to generate the active form of the drug. Furthermore, tolerance to the vasodilator effects of organic nitrates is associated with impairment of this metabolic activation process. Despite considerable research effort, the intracellular processes and the chemical reaction pathways by which organic nitrates are converted to their active form are still unresolved. This review by Brian Bennett and colleagues summarizes the characteristics of organic-nitrate biotransformation in vascular smooth muscle, the difficulties encountered when assessing this biotransformation, and the evidence for the role of two identified vascular biotransformation systems (glutathione-S-transferases and the cytochrome P450 system) in the metabolic activation of organic nitrates.
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Affiliation(s)
- B M Bennett
- Department of Pharmacology and Toxicology, Queen's University, Kingston, Ontario, Canada
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Nigam R, Whiting T, Bennett BM. Effect of inhibitors of glutathione S-transferase on glyceryl trinitrate activity in isolated rat aorta. Can J Physiol Pharmacol 1993; 71:179-84. [PMID: 8100477 DOI: 10.1139/y93-025] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We investigated the role of glutathione S-transferases (enzymes known to biotransform organic nitrates) in the vascular action of glyceryl trinitrate (GTN). Relaxation of phenylephrine-contracted rat aortic strips was assessed in the presence or absence of the glutathione S-transferase inhibitors Basilen Blue, bromosulfophthalein, Rose Bengal, hematin, chlorotriphenyltin, and (octyloxy)benzoylvinylglutathione. Whereas none of the inhibitors increased the EC50 for GTN relaxation, glutathione S-transferase activity in the 100,000 x g supernatant fraction of rat aorta was inhibited markedly by most of the inhibitors. In addition, GTN-stimulated activation of aortic guanylyl cyclase in broken-cell preparations was attenuated by all of the glutathione S-transferase inhibitors, suggesting a direct inhibitory action on guanylyl cyclase. In other experiments using aortic strips preexposed to phenylephrine, the inhibitors had no effect on GTN-induced cyclic GMP accumulation or on vascular biotransformation of GTN. In contrast, both Basilen Blue and bromosulfophthalein significantly inhibited GTN-induced relaxation of K(+)-contracted aortic strips, and Basilen Blue significantly inhibited GTN biotransformation in aortic strips preexposed to 25 mM K+. This may be due to a more favourable electrochemical gradient for entry of the inhibitors into membrane-depolarized tissues. We conclude that vascular glutathione S-transferases play a role in mediating the vasodilator actions of GTN in intact tissues in vitro, but that this appears to depend upon the nature of the contractile agent used in such studies.
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Affiliation(s)
- R Nigam
- Department of Pharmacology and Toxicology, Faculty of Medicine, Queen's University, Kingston, Ont., Canada
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