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Kidavu AVS, Chaudhary AK. Low level detection of acetone vapor by improvised design of high "Q" tunable frequency Helmholtz photoacoustic cell using UV, mid- IR and THz sources. Spectrochim Acta A Mol Biomol Spectrosc 2023; 303:123218. [PMID: 37556924 DOI: 10.1016/j.saa.2023.123218] [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: 03/20/2023] [Revised: 07/19/2023] [Accepted: 07/28/2023] [Indexed: 08/11/2023]
Abstract
The paper reports the designing and fabrication aspects of a high "Q = 492.3" Helmholtz photoacoustic (PA) cell employed for the trace level detection of acetone, a biomarker by using 266 nm- UV, Mid-IR (5.4-10.6 micron) and 0.11 Terahertz (THz) sources. The designed Helmholtz PA cell is made of Aluminum and possesses a natural frequency tunable between 1.4 to 4.4 kHz range using a movable piston arrangement of the microphone sensor. Numerous types of disorders, including diabetes, asthma, lung cancer, etc., can be diagnosed using the acetone concentration obtained through breath analysis. The comparative study is related to the response of different types of excitation mechanisms contributed by electronics, vibrational and rotational modes of acetone. The low-level detection (LoD) limit for acetone is of the order of 5.06 & 7.92 ppbV, and 15.3 pptV, respectively, in UV, Mid-IR, and THz region. This study contributes to the development of a highly sensitive, non-invasive acetone detection and quantification modality.
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Affiliation(s)
- Arjun V S Kidavu
- Advanced Centre for Research in High Energy Materials University of Hyderabad, Hyderabad 500046, India
| | - A K Chaudhary
- Advanced Centre for Research in High Energy Materials University of Hyderabad, Hyderabad 500046, India.
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Ghorui C, Chaudhary AK. Linear and nonlinear optical characterization of tellurium dioxide (α-TeO 2) for generation of terahertz radiation using time-domain spectroscopy. Appl Opt 2023; 62:4831-4835. [PMID: 37707258 DOI: 10.1364/ao.491556] [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] [Received: 03/27/2023] [Accepted: 05/22/2023] [Indexed: 09/15/2023]
Abstract
This paper reports the linear and nonlinear optical characterization of α-T e O 2 crystal in the optical and terahertz domains for efficient terahertz (THz) generation using a difference frequency mixing technique. We have ascertained the optical properties such as refractive index, absorption coefficients, real and imaginary dielectric constants, and coherence length l c=280m m at 1.77 THz range using an indigenously developed THz spectrometer. The value of refractive index was ascertained from temporal and spectral THz profiles of the crystal and employed for calculating the Type I phase-matching angle, i.e., θ=21.15∘ for the generation of tunable radiation between the 0.1 and 1.9 THz range. The figure of merits in the optical and THz domains lie between the 0.02-0.015 range. The effective bandwidth of the crystal lies between the 0.1 and 3.0 THz range.
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Mahendar M, Krishna RNV, Chaudhary AK. Effect of the annealing temperature on structural, morphological, and nonlinear optical properties of TeO 2 thin films used for efficient THz generation. Appl Opt 2023; 62:2394-2402. [PMID: 37132786 DOI: 10.1364/ao.480827] [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: 05/04/2023]
Abstract
This paper reports the effect of annealing on T e O 2 films deposited using the thermal evaporation technique. T e O 2 films of 120 nm thickness were grown on a glass substrate at room temperature (RT) and annealed at 400°C and 450°C. The structure of the film and the influence of the annealing temperature on the crystalline phase change were examined using the X-ray diffraction method. Optical properties such as transmittance, absorbance, complex refractive index, and energy bandgap were determined between ultraviolet-visible to terahertz (THz) range. These films have a direct allowed transition with the optical energy bandgap of 3.66, 3.64, and 3.54 eV at as-deposited temperatures (RTs) of 400°C and 450°C. The effect of the annealing temperature on the morphology and surface roughness of the films was investigated using atomic force microscopy. The nonlinear optical parameters, which are the refractive index and absorption coefficients, were calculated using THz time domain spectroscopy. The microstructure variation of the T e O 2 films in terms of surface orientation plays an important role in understanding the change in the nonlinear optical properties of the films. Finally, these films were subjected to 800 nm wavelength of 50 fs pulse duration obtained from a Ti:sapphire amplifier at a 1 kHz repetition rate for efficient THz generation. The power of incidence of the laser beam was tuned at a range between 75 and 105 mW; the highest power of the generated THz signal was of the order of 210 nW for 450°C annealed film with respect to the incident power of 105 mW. The conversion efficiency was found to be ∼0.22×10-5 %, which is 2.025 times more than the film annealed at 400°C.
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Sharma S, Gupta V, Bawa A, Kumar A, Pooni PA, Gautam PL, Chaudhary AK, Chhina RS. Contact Tracing of Healthcare Workers Exposed to COVID-19 Infection in a Tertiary-Care Hospital: Containing the Contagion. Indian J Community Med 2023; 48:155-160. [PMID: 37082385 PMCID: PMC10112743 DOI: 10.4103/ijcm.ijcm_1523_21] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 09/21/2022] [Indexed: 12/05/2022] Open
Abstract
Introduction Healthcare workers (HCWs) are at higher risk of getting infected with COVID-19 infection due to their close proximity to COVID-19-positive patients. We studied the risk stratification and positivity rate in HCWs at risk of getting COVID-19 infection as well as the possible factors responsible for their being at risk of COVID-19 infection during the study period. Material and Methods This prospective study was conducted after approval by the institutional ethics committee. The data regarding demographic variables, risk stratification, COVID-19 (reverse-transcription polymerase chain reaction) report, and possible sources of exposure for HCWs were recorded in a proforma by personal/telephonic interviews as well as from hospital records from March 2020 to June 2021. The data generated were entered into Microsoft Excel® software and analyzed using percentages, proportions, and Chi-square tests for qualitative variables. Results COVID-19 infection's positivity rate was 19.5% among high-risk and 0.6% among low-risk HCW contacts. HCWs working in non-COVID-19 areas (67.9%) were more at risk than those working in COVID-19 areas (32.1%). In contrast, the COVID-19 positivity rate was significantly higher among high-risk contact HCWs from COVID-19 areas (34.2%) than in non-COVID-19 areas (12.6%). The maximum COVID-19 positivity rate was seen in high-risk contacts with body fluid exposure (21%), performing aerosol-generating procedures (20%), and close exposure in operation theaters (18%). Conclusions Risk stratification is an important tool to contain infection among HCWs who had unprotected close contact with a COVID-19-positive case. With appropriate contact tracing, we were able to avoid over- and under-quarantine, save many man-hours as well as contain the spread of infection. HCWs should not only wear appropriate personal protective equipment (PPE) during work hours but should also practice mask-wearing and social distancing while they are in the community.
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Affiliation(s)
- Sarit Sharma
- Department of Community Medicine, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Vikas Gupta
- Department of Rheumatology and Immunology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Ashvind Bawa
- Department of Surgery, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Ajay Kumar
- Department of Anatomy, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Puneet Aulakh Pooni
- Department of Paediatrics, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Parshotam Lal Gautam
- Department of Critical Care Medicine, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | | | - Rajoo Singh Chhina
- Department of Gastroenterology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
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Soni A, Dhanota DS, Tyagi R, Chaudhary AK, Kaur H, Sood N. Contiguous Lumbar Vertebral Involvement with Vertebral Collapse in Giant Cell Tumor: A Usual Tumor with an Unusual Presentation. J Lab Physicians 2022; 15:156-158. [PMID: 37064975 PMCID: PMC10104703 DOI: 10.1055/s-0042-1750069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
Abstract
AbstractGiant cell tumor (GCT) is a primary bone tumor of long bones, which can rarely involve the vertebrae. Contiguous vertebral involvement by GCT is a rare presentation and poses a diagnostic dilemma on imaging. We report a case of GCT involving three contiguous lumbar vertebrae causing vertebral collapse along with a large soft tissue component. Considering the site and clinical presentation, possibilities of a round cell tumor with large extraosseous soft tissue component and malignant neurogenic tumor were suggested on initial radiological examination but histopathology confirmed the diagnosis of GCT. It is important to diagnose this entity correctly because of totally different lines of management. In our case, initial surgical management was excluded in view of high surgical morbidity and, thereby, adjuvant therapy with denosumab was planned.
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Affiliation(s)
- Ankita Soni
- Department of Pathology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | | | - Ruchita Tyagi
- Department of Pathology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | | | - Harpreet Kaur
- Department of Neurosurgery, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Neena Sood
- Department of Pathology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
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Sobti S, Singh J, Sharma S, Bansal H, Chaudhary AK. Clinicoradiological Profile and Outcome of Microsurgical Clipping of Ruptured Anterior Circulation Aneurysms: A Single-Institute Experience. Asian J Neurosurg 2021; 16:316-320. [PMID: 34268158 PMCID: PMC8244689 DOI: 10.4103/ajns.ajns_483_20] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/25/2020] [Accepted: 01/26/2021] [Indexed: 12/02/2022] Open
Abstract
Introduction: Prevalence of intracranial aneurysms is estimated to be from 1% to 5% of population, most of them are small and located in the anterior circulation. The real danger is when an aneurysm ruptures, leading to a subarachnoid hemorrhage (SAH). SAH is a catastrophic event with a mortality rate of 25% to 50%. Permanent disability occurs in nearly 50% of the survivors. Fifteen percent of patients expire before reaching the hospital and 25% die within 24 h. The purpose of our study is to report the clinicoradiological data and outcome of microsurgical clipping of ruptured anterior circulation aneurysms in our center. Materials and Methods: This study included ruptured anterior circulation aneurysms admitted to tertiary care hospital in northern India from January 2018 to June 2020. The final outcome of patients was analyzed with Glasgow Outcome Score (GOS) at the time of discharge from the hospital. Results: A total of 53 patients with ruptured anterior circulation aneurysm underwent microsurgical clipping comprising 25 (47.2%) males and 28 (52.8%) females. The mean neck size of all aneurysms was 3.43 ± 1.66 mm. The mean hospital stay was longer in patients having preoperative intraventricular hemorrhage (IVH) (35.96 ± 27.27 days) and postoperative complications (43.36 ± 29.76 days) compared to patients who did not have IVH (21.10 ± 15.47 days) and postoperative complications (18 ± 6.54 days). P value was ≤0.05. Patients with preoperative hydrocephalus had GOS 3.44 ± 1.20 at discharge compared to nonhydrocephalus who had GOS 4.32 ± 1.07 (P = 0.009). Patients with Intracerebral Hemorrhage (ICH) and non-ICH had GOS 3.31 ± 1.38 and 4.28 ± 1.01, respectively (P = 0.009). Conclusion: Poor outcome at the time of discharge after the surgical treatment of anterior circulation aneurysms was associated with poor world federation of neurological surgeons grade on admission, presence of IVH, hydrocephalus, intracerebral hemorrhage, and postoperative cerebral infarcts.
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Affiliation(s)
- Shivender Sobti
- Department of Neurosurgery, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Jagminder Singh
- Department of Neurosurgery, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Saurabh Sharma
- Department of Neurosurgery, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Hanish Bansal
- Department of Neurosurgery, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
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Ghorui C, Rudra AM, Chatterjee U, Chaudhary AK, Ganesh D. Efficient second-harmonic and terahertz generation from single BiB 3O 6crystal using nanosecond and femtosecond lasers. Appl Opt 2021; 60:5643-5651. [PMID: 34263857 DOI: 10.1364/ao.424241] [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] [Received: 03/11/2021] [Accepted: 05/30/2021] [Indexed: 06/13/2023]
Abstract
The paper reports the efficient UV and terahertz generation from a 1.29 mm thick and Type I, θ=28.9∘ cut BiB3O6 (bismuth triborate, BIBO) crystal using femtosecond and nanoseconds laser pulses. We have employed 800 nm wavelength pulses of 50 and 140 fs obtained from a Ti:sapphire laser amplifier and oscillators at 1 kHz and 80 MHz repetition rates, respectively. The conversion efficiency of second-harmonic generation (SHG) was ∼50% while that obtained for terahertz (THz) generations was of the order of 1.85×10-5%. In addition, LDS-698 dye laser radiation tunable between 650-700 nm was also used as a source for SHG between the 325-350 nm range. The dye laser was pumped by SHG (532 nm) radiation from an electro-optically Q-switched Nd:YAG laser having a pulse repetition rate of 10 Hz and a pulse width of 10 ns. A conversion efficiency of 4.01% was obtained for generation of UV at 343.5 nm. Finally, we have measured the transmission, refractive index, absorbance, and conductivity properties of BIBO crystal in the THz domain. We also ascertained the coherence length, relative permittivity and reflectivity of the crystal.
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Ramachandran K, Kumari A, Nath Acharyya J, Chaudhary AK. Study of photo induced charge transfer mechanism of PEDOT with nitro groups of RDX, HMX and TNT explosives using anti-stokes and stokes Raman lines ratios. Spectrochim Acta A Mol Biomol Spectrosc 2021; 251:119360. [PMID: 33453599 DOI: 10.1016/j.saa.2020.119360] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 11/25/2020] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
The paper reports the charge transfer mechanism between poly (3,4-ethylenedioxythiophene) (PEDOT) and high energy materials such as RDX, HMX and TNT, respectively in terms of ratios of anti-stokes (AS) and stokes(S) Raman lines of NO2 bands. Generally it works as an effective sensing medium for the detection of explosives when mixed in an equal proportion and are subjected to 532 nm wavelength without any chemical treatment [1]. The pristine PEDOT is less sensitive to 532 nm wavelength (2.33 eV) but influences the Raman S and AS lines of explosives in the mixture. The study also reveals that a small quantity (one milligram) of PEDOT is sufficient to initiate the positive charge transfer mechanism between its oxidized state to the lone pairs of electrons on the oxygen atoms of the nitro group of the explosive molecules. Consequently, the intensity of the Raman spectra of RDX, HMX and TNT is dropped by an order of 22.5, 11.45 and 17.2 times, respectively along with the shift of the NO2 vibrational modes. It is also attributed to Photon-electron-phonon interaction. Finally, we have estimated the reduced mass of the functional group to ascertain the force constant and the intensity ratios of AS /S lines to confirm the charge transfer mechanism. The effect of charge transfer mechanism is also reflected in drastic change in transmission /absorption characteristics of FTIR spectra of same PEDOT and explosive mixtures.
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Affiliation(s)
- K Ramachandran
- Advanced Centre for Research in High Energy Materials, University of Hyderabad, Telangana, 500046, India; National Center for Physical Acoustics, The University of Mississippi, 145 Hill Drive University, MS 38677- 1848, United States
| | - Archana Kumari
- Advanced Centre for Research in High Energy Materials, University of Hyderabad, Telangana, 500046, India
| | - Jitendra Nath Acharyya
- Advanced Centre for Research in High Energy Materials, University of Hyderabad, Telangana, 500046, India; Department of Physics, Indian Institute of Technology, Hauz Khas, Delhi 110016, India
| | - A K Chaudhary
- Advanced Centre for Research in High Energy Materials, University of Hyderabad, Telangana, 500046, India.
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Kumari A, Chaudhary AK, Rajasekhar K. Study of charge transfer mechanism of PEDOT polymer for detection of solid TEX and CL-20 explosives using pulsed photoacoustic technique. Spectrochim Acta A Mol Biomol Spectrosc 2020; 241:118597. [PMID: 32679485 DOI: 10.1016/j.saa.2020.118597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 05/08/2020] [Accepted: 06/06/2020] [Indexed: 06/11/2023]
Abstract
We report the use of PEDOT polymer (poly (2, 3-dihydrothieno [3,4-b] dioxane-5,7-diyl) as a sensing medium for the detection of solid secondary explosives like TEX and CL-20 in solid form using pulsed photoacoustic (PA) technique under visible 532 nm wavelength. The PEDOT polymer (poly (2, 3-dihydrothieno [3,4-b] dioxane-5,7-diyl) plays the role of an optode or an effective sensing medium for the detection of explosives when mixed in equal proportion and subjected to 532 nm wavelength obtained from Q-switched Nd: YAG laser without any chemical treatment. The study reveals that one milligram of PEDOT is sufficient to initiate the charge transfer mechanism between the positive charge on the oxidized PEDOT and the lone pairs of electrons on the oxygen atoms of the nitro group of the explosives. The strength of the enhanced PA signal for TEX and CL-20 was of the order of 65.38 and 1.77 times, respectively. However, the same experiment was repeated with non-explosive samples such as NaNO2 and NaNO3, separately mixed with PEDOT. The obtained peaks of PA spectra were very weak, broaden and distorted in nature and occupies less than 3 kHz frequency rage and 3.5 times less than the PA signal of pure PEDOT. The estimated minimum detection limit of the solid explosives, CL-20 and TEX were of the order of 0.33 ng and 1.03 ng, respectively.
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Affiliation(s)
- Archana Kumari
- Advanced Centre for Research in High Energy Materials, University of Hyderabad, Hyderabad 500046, India
| | - A K Chaudhary
- Advanced Centre for Research in High Energy Materials, University of Hyderabad, Hyderabad 500046, India.
| | - K Rajasekhar
- Advanced Centre for Research in High Energy Materials, University of Hyderabad, Hyderabad 500046, India
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Ajith Y, Dimri U, Madhesh E, Gopalakrishnan A, Verma MR, Samad HA, Reena KK, Chaudhary AK, Devi G, Bosco J. Influence of weather patterns and air quality on ecological population dynamics of ectoparasites in goats. Int J Biometeorol 2020; 64:1731-1742. [PMID: 32556594 DOI: 10.1007/s00484-020-01952-7] [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: 04/17/2019] [Revised: 05/10/2020] [Accepted: 06/04/2020] [Indexed: 06/11/2023]
Abstract
Ectoparasitism has a damaging impact on the economy of goat production in India, but the factors influencing its distribution and dynamics are less explored. The present study was designed to investigate the influence of environmental factors like weather and air quality parameters on the occurrence of different types of ectoparasites in goats of two agro-climatic regions of India, viz. the Upper Gangetic Plain (UGP) and the Western Himalayas (WH). The prevalence survey for ectoparasitism among goats was conducted during the four distinct climatic seasons (winter, summer, monsoon, autumn) in both regions. The season-wise data of weather parameters (maximum and minimum temperature, relative humidity in morning and evening, sunrise and sunset time, mean daily temperature and relative humidity, daily variation in temperature and relative humidity, and day length) and air quality parameters (air quality index (AQI), particulate matter 2.5 μm (PM2.5), particulate matter 10 μm (PM10)) of both regions were analyzed in relation with the ectoparasitic prevalence pattern of corresponding regions. The results depict a noticeable correlation between the studied parameters and seasonal variation in the occurrence of each type of ectoparasites. This outcome on the interaction of studied parameters and ectoparasitism is intriguing and it opens a huge scope for future studies on the biometeorological aspects of host-parasite ecological interplay and evolutionary biology. The better understanding of climatological aspects of ectoparasite occurrences helps goat farmers in formulating appropriate timely intervention strategies for the economic control of ectoparasites, which in turn tackles ectoparasiticidal drug resistance and reduces threat of vector-borne diseases.
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Affiliation(s)
- Y Ajith
- Division of Medicine, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India.
- Department of Veterinary Medicine, Faculty of Veterinary and Animal Sciences, Banaras Hindu University, Rajiv Gandhi South Campus, Mirzapur, UP, 231001, India.
- Banaras Hindu University, Varanasi, India.
| | - U Dimri
- Division of Medicine, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India
| | - E Madhesh
- Division of Medicine, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India
| | - A Gopalakrishnan
- Division of Medicine, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India
| | - Med Ram Verma
- Division of Livestock Economics, Statistics and Information Technology, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India
| | - H A Samad
- Division of Physiology & Climatology, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India
| | - K K Reena
- Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India
| | - A K Chaudhary
- Division of Medicine, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India
| | - G Devi
- Division of Medicine, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India
| | - J Bosco
- Division of Physiology & Climatology, ICAR-Indian Veterinary Research Institute, Izatnagar, UP, 243122, India
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Vira HJ, Pradhan VD, Umare VD, Chaudhary AK, Rajadhyksha AG, Nadkar MY, Ghosh K, Nadkarni AH. Expression of the matrix metalloproteinases MMP-2 and MMP-9 and their inhibitors TIMP-1 and TIMP-2 in systemic lupus erythematosus patients. Neth J Med 2020; 78:261-268. [PMID: 33093251] [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: 06/11/2023]
Abstract
BACKGROUND The study aimed to look at alterations in expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) and their potential use as biomarkers in the pathogensis of SLE. METHODS SLE patients (n = 41) and healthy controls (n = 50) were recruited. Quantitative RT-PCR/ELISA assays were performed for expression of MMP and TIMP mRNA in whole blood and PBMC; and corresponding serum protein levels. Intracellular levels of MMP-2 and MMP-9 proteins were analysed by flow cytometry. RESULTS Based on SLEDAI scores patients were grouped into active (SLEDAI ≥ 10) and inactive cases (SLEDAI < 10). In active cases, MMP-2 expression significantly increased and TIMP-2 expression was decreased (p < 0.0001) both at serum secretion (p = 0.0003) and mRNA (p < 0.0001) levels as compared to inactive cases. MMP-9 and TIMP-1 showed significantly reduced serum secretion and mRNA expression (p < 0.0001) in active cases as compared to inactive cases. Intracellular concentration of MMP-9 was reported to be higher in neutrophils, while MMP-2 was mainly found in lymphocytes of SLE patients as compared to controls. MMP/TIMP ratio profile was altered as SLE disease progresses. INTERPRETATION & CONCLUSIONS Findings suggest disturbed MMP and TIMP levels have a role in the pathogenesis of SLE.
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Affiliation(s)
- H J Vira
- Department of Clinical and Experimental Immunology, National Institute of Immunohaematology, Indian Council of Medical Research, Mumbai, India
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Kumari A, Chaudhary AK, Venkatesh M. Linear and nonlinear temperature-dependent transmission/absorption characteristics of cadmium telluride crystal for terahertz generation. Appl Opt 2020; 59:3417-3421. [PMID: 32400454 DOI: 10.1364/ao.366208] [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] [Received: 12/01/2019] [Accepted: 03/07/2020] [Indexed: 06/11/2023]
Abstract
This paper reports on the temperature-dependent investigation of linear and nonlinear transmission/absorption characteristics of CdTe crystal in the 300-408 K range using 780-970 nm tunable wavelengths of 140 fs pulses obtained from a Ti:Sapphire laser at 80 MHz repetition rate. The same pulses were also used for terahertz generation. The linear transmission/absorption properties were measured using a specially improvised temperature-tuned spectrophotometer in the 500-1500 nm wavelength range. The linear absorption of 750 nm wavelength gradually increases with respect to a rise in the temperature, and transmission becomes zero at 408 K. Nonlinear absorption induced by femtosecond pulses shows a sudden drop of 18% in transmission above the 800 nm range, due to electron-phonon interaction, which affects the strength of the terahertz signal. It is also responsible for change in the temperature along with the linear shift in the refractive index of the crystal.
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Rao KS, Ganesh D, Yehya F, Chaudhary AK. A comparative study of thermal stability of TNT, RDX, CL20 and ANTA explosives using UV 266 nm-time resolved photoacoustic pyrolysis technique. Spectrochim Acta A Mol Biomol Spectrosc 2019; 211:212-220. [PMID: 30550983 DOI: 10.1016/j.saa.2018.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 11/11/2018] [Accepted: 12/05/2018] [Indexed: 06/09/2023]
Abstract
The paper reports the potential use of UV based pulsed photoacoustic spectroscopy to study the thermal stability of some well-known premier explosives such as TNT, RDX, CL20, and ANTA between 30 and 350 °C range. The thermal PA spectra of samples were recorded using fourth harmonic wavelength i.e. 266 nm of pulse duration 7 ns and repetition rate 10 Hz obtained from Q-switched Nd: YAG laser system. Under the influence of UV radiation, the explosive molecules in vapor phase follow the photodissociation process and converted into their byproducts such as NO, NO2 and N2O etc. due to π* ← n transitions, which are responsible for the generation resultant PA signal at 266 nm wavelength. The results obtained from PA spectra as a function of temperature are cross verified with Thermo gravimetric-differential thermal analysis (TG-DTA) to ascertain the thermal stability of these samples. The comparative PA spectra of samples were analyzed and shown the behavior of acoustic modes with respect to incident laser energy, and data acquisition time. Finally, the thermal quality factor "Q" is measured to test the stability of reported explosives.
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Affiliation(s)
- K S Rao
- Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, 500046, India
| | - D Ganesh
- Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, 500046, India
| | - F Yehya
- Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, 500046, India; Department of Physics, Faculty of Education, Al-Baida University, Al-Baida 38018, Yemen
| | - A K Chaudhary
- Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, 500046, India.
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Rao KS, Razdan AK, Tyagi A, Chaudhary AK. Temperature dependent time resolved mid-IR photoacoustic spectroscopy of a nerve gas simulant DMMP. Spectrochim Acta A Mol Biomol Spectrosc 2018; 204:696-701. [PMID: 29982161 DOI: 10.1016/j.saa.2018.06.089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 01/11/2018] [Revised: 05/18/2018] [Accepted: 06/23/2018] [Indexed: 06/08/2023]
Abstract
The paper reports the temperature dependent pulsed photoacoustic spectroscopy of Dimethyl methylphosphonate (DMMP) a nerve gas simulant between 50 and 180 °C temperature range. The time domain PA spectra are recorded using two mid-IR wavelengths i.e. 3374 nm, 3495 nm of pulse duration 1.5 ns at 1 kHz repetition rate obtained from optical parametric oscillator. Two anti-symmetric stretching vibrational modes of (CH3P) and (CH3O) groups of DMMP molecules have very strong vibrational peaks at 2861.2 cm-1 (3495 nm) and 2963.8 cm-1 (3374 nm), respectively. In addition, we have also recorded the PA spectra of acetone at the vibrational frequency 3115.2 cm-1 (3210 nm), which is the strong vibrational mode of CH band. The comparison of two PA spectra of DMMP and acetone recorded using similar PA cavity help us to understand the effect of other functional groups with respect to different excitation wavelengths. The presence of additional acoustic modes in the PA spectra of DMMP (3374 nm) above the boiling point confirms the slow process of thermal decomposition. Finally, the low level detection limit of DMMP in air is of the of the order of 0.91 ppbV.
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Affiliation(s)
- K S Rao
- Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad, Hyderabad 500046, India; The Guo China-US Photonics Laboratory, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, China
| | - A K Razdan
- Laser Science & Technology Centre (LASTEC), Delhi 110054, India
| | - Akansha Tyagi
- Laser Science & Technology Centre (LASTEC), Delhi 110054, India
| | - A K Chaudhary
- Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad, Hyderabad 500046, India.
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15
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Damarla G, Venkatesh M, Chaudhary AK. Temperature-dependent terahertz spectroscopy and refractive index measurements of aqua-soluble and plastic explosives. Appl Opt 2018; 57:8743-8750. [PMID: 30461953 DOI: 10.1364/ao.57.008743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/11/2018] [Indexed: 06/09/2023]
Abstract
The paper reports the temperature-dependent time domain terahertz spectroscopy of premium aqua-soluble and plastic explosives such as NH4NO3, TNT, and RDX between 0.1 and 2.2 THz. Tunable terahertz radiation was generated using ZnTe crystal as a source, and a photoconductive antenna was used as a detector. The temperature-dependent study was carried out between 30°C and 200°C in a specially designed oven. The signature peaks of RDX and TNT present at 0.82 and 1.60 THz, respectively, show a strong redshift, whereas the NH4NO3 molecule shows a comparatively small shift. The high-temperature-based redshift phenomenon is just the opposite of the blueshift recorded at low temperatures. In addition, the temperature-dependent absorption coefficient data of these molecules support the change in the concentration of the NO2 molecule. We have also ascertained the temperature-dependent refractive indices of these molecules between 0.1 and 2.0 THz, which confirms the effect of temperature on the refractive indices. Finally, the signature peak of RDX with respect to the reduction in the weight concentration of RDX in the Teflon matrix was studied at 0.82 THz.
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Yadav KD, Chaudhary AK, Verma AK. Bioavailability Enhancement of Partially Water Soluble Solid Medicament in Traditional System of Medicine. Indian J Pharm Sci 2017. [DOI: 10.4172/pharmaceutical-sciences.1000278] [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: 11/09/2022] Open
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Kumar Chaudhary A, Bansal H. Penetrating Head Injury from Angle Grinder at Workplace: Case Report and Review of Literature. IJNT 2016. [DOI: 10.1055/s-0036-1597750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | - Hanish Bansal
- Department of Neurosurgery, Dayanand Medical College & Hospital, Ludhiana, Punjab, India
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Chaudhary AK, Mohapatra R, Nagarajaram HA, Ranganath P, Dalal A, Dutta A, Danda S, Girisha KM, Bashyam MD. The novel EDAR p.L397H missense mutation causes autosomal dominant hypohidrotic ectodermal dysplasia. J Eur Acad Dermatol Venereol 2016; 31:e17-e20. [PMID: 27168349 DOI: 10.1111/jdv.13587] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
| | - R Mohapatra
- Laboratory of Computational biology, Hyderabad, India
| | | | - P Ranganath
- Diagnostics Division, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.,Nizam's Institute of Medical Sciences, Hyderabad, India
| | - A Dalal
- Diagnostics Division, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
| | - A Dutta
- Christian Medical College, Vellore, India
| | - S Danda
- Christian Medical College, Vellore, India
| | - K M Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal University, Manipal, India
| | - M D Bashyam
- Laboratory of Molecular Oncology, Hyderabad, India
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Chaudhary AK, Rao KS, Sudheer Kumar A. Study of thermal decomposition mechanisms and absorption cross section of nitro-rich phenyl- and bis-series 1,2,3-triazoles. Appl Opt 2016; 55:817-824. [PMID: 26836085 DOI: 10.1364/ao.55.000817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This paper reports the investigation of thermal decomposition mechanisms and evaluation of thermally released NO2 from two newly synthesized high-energy materials named 1-(4-nitrophenyl)-1H-1,2,3-triazole (S8) and 2,6-bis ((4-(nitromethyl)-1H-1,2,3-triazol-1-yl)methyl) pyridine (S9) using time-resolved pulsed photoacoustic (PA) pyrolysis technique. The PA spectra were recorded between the 30°C and 350°C range and by varying the pressure of compounds vapor using 532 nm wavelength of pulse duration 7 ns at 10 Hz repetition rate obtained from Q-switched Nd:YAG laser pulses. The PA results were cross verified with thermogravimetric-differential thermal analysis data. The quality factor "&=&Q"&=& of the PA cavity was measured to test the thermal stability of the compound. In addition, we have ascertained the molecular density, absorption cross sections of high-energy materials vapor in terms of NO2. The corresponding values are of the order of 0.1-1.2×10(20) cm-3 and 0.5-6 kilobarn, respectively. These results once again confirm the close agreement between the radiative and nonradiative transitions data and established the role of NO2 during the thermal decomposition process.
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Bansal H, Chaudhary AK, Mahajan A. Large Cervical Paraspinal Haemangioma in Association with Intraosseous Haemangioma: A Rare Case Report. J Clin Diagn Res 2015; 9:PD01-2. [PMID: 26435996 DOI: 10.7860/jcdr/2015/13513.6292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 02/14/2015] [Accepted: 06/09/2015] [Indexed: 11/24/2022]
Abstract
Haemangiomas are most commonly found in skin and subcutaneous tissue and are very rare in intramuscular region. Paraspinal musculature has been barely reported as location of intramuscular haemangioma while we could not find any literature reporting haemangioma in cervical paraspinal previously. We report a case of middle aged woman with a large intamuscular haemangioma involving left cervical paraspinal musculature extending from suboccipital region to C5 vertebra and reaching upto left parotid gland along with C6 vertebral body haemangioma.
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Affiliation(s)
- Hanish Bansal
- Assistant Professor, Department of Neurosurgery, Dayanand Medical College and Hospital , Ludhiana, India
| | - Ashwani Kumar Chaudhary
- Professor, Department of Neurosurgery, Dayanand Medical College and Hospital , Ludhiana, India
| | - Anuj Mahajan
- Resident, Department of Surgery, Dayanand Medical College and Hospital , Ludhiana, India
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Rao KS, Chaudhary AK, Yehya F, Kumar AS. Study of acoustic fingerprinting of nitromethane and some triazole derivatives using UV 266 nm pulsed photoacoustic pyrolysis technique. Spectrochim Acta A Mol Biomol Spectrosc 2015; 147:316-323. [PMID: 25854611 DOI: 10.1016/j.saa.2015.03.017] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 01/06/2015] [Accepted: 03/01/2015] [Indexed: 06/04/2023]
Abstract
We report a comparative study of acoustic fingerprints of nitromethane, nitrobenzene and some nitro rich triazole derivatives using pulsed photoacoustic technique. UV 266 nm wavelength i.e. Fourth harmonic of Q-switched Nd: YAG laser having pulse duration 7 ns and 10 Hz repetition rate is employed to record the time resolved PA spectrum. The PA fingerprint is produced due to absorption of incident UV light by molecule itself and photo dissociation of nitromethane and nitrobenzene at room temperature while in case of triazole it is attributed to the combination of thermal and photo-dissociation process. The entire dissociation process follows the root of cleavage of C-NO₂ bond to produce free NO, NO₂ and other by product gases due to π(∗)←n excitation. In addition, we have studied the thermal stability criteria of nitro rich triazoles based on the quality factor of acoustic resonance frequencies of the PA cavity. We have also studied the effect of data acquisition time to ascertain the decay behavior of HEMs samples.
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Affiliation(s)
- K S Rao
- Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad, Hyderabad 500046, India
| | - A K Chaudhary
- Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad, Hyderabad 500046, India.
| | - F Yehya
- Department of Mathematics and Physics, Faculty of Education, Al-Baida University, Al-Baida 38018, Yemen
| | - A Sudheer Kumar
- Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad, Hyderabad 500046, India
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Maiwall R, Kumar S, Chaudhary AK, Maras J, Wani Z, Kumar C, Rastogi A, Bihari C, Vashisht C, Sarin SK. Serum ferritin predicts early mortality in patients with decompensated cirrhosis. J Hepatol 2014; 61:43-50. [PMID: 24681346 DOI: 10.1016/j.jhep.2014.03.027] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 03/05/2014] [Accepted: 03/13/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Serum ferritin is a known marker of hepatic necro-inflammation and has been studied to predict 1 year mortality and post-transplant survival in decompensated cirrhotics. However, there are no studies evaluating ferritin as a predictor of early mortality. We investigated whether serum ferritin levels could predict 15 day and 30 day mortality in patients with decompensated cirrhosis. METHODS 318 patients with decompensated cirrhosis were included. RESULTS Patients of decompensated cirrhosis [257 males, mean age of 51 [±13]years, were followed for a median of 31 days. Serum ferritin levels were significantly different between survivors and non-survivors [p<0.001] and showed significant correlation with MELD score [p<0.001], CTP score [p<0.001], leucocyte counts [TLC] [p<0.001], serum sodium [p<0.001], ACLF grades [p=0.005], spontaneous bacterial peritonitis [SBP] [p=0.02], hepatic encephalopathy [HE] [p<0.001] and hepatorenal syndrome [HRS] [p=0.012]. Serum ferritin, etiology, MELD, HE, CTP score, sodium, TLC, and ACLF grades were significant predictors of mortality on univariate analysis. Ferritin [p=0.04, HR 1.66 95% CI (1.02-2.73)] was a significant predictor of early mortality on multivariate analysis along with HE [p=0.006, HR 3.47 95% CI (2.13-8.41)] (Model 1), TLC [p=0.02, HR 1.81 95% CI (1.06-3.07)] (Model 2), ACLF grades [p=0.018, HR 2.013,95% CI (1.126-3.60)], and CTP score [p<0.0001, HR 1.36 95% CI (1.17-1.59)] (Model 3). CONCLUSION Serum ferritin levels correlate with severity of hepatic decompensation and are associated with early liver related death independent of the MELD score in hospitalized patients with decompensated cirrhosis. This could also have a potential therapeutic implication.
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Affiliation(s)
- Rakhi Maiwall
- Department of Hepatology, Institute of Liver and Biliary Sciences, Delhi, India
| | - Suman Kumar
- Department of Clinical Hematology, Command Hospital [Eastern Command], Kolkata, India
| | - A K Chaudhary
- Department of Hepatology, Institute of Liver and Biliary Sciences, Delhi, India
| | - Jaswinder Maras
- Department of Research, Institute of Liver and Biliary Sciences, Delhi, India
| | - Zeeshan Wani
- Department of Hepatology, Institute of Liver and Biliary Sciences, Delhi, India
| | - Chandan Kumar
- Department of Hepatology, Institute of Liver and Biliary Sciences, Delhi, India
| | - A Rastogi
- Department of Pathology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - C Bihari
- Department of Pathology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Chitranshu Vashisht
- Department of Hepatology, Institute of Liver and Biliary Sciences, Delhi, India
| | - S K Sarin
- Department of Hepatology, Institute of Liver and Biliary Sciences, Delhi, India.
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Chaudhary AK. Rare Cause of Recurrent Stroke: Bilateral Cervical Internal Carotid Artery Aneurysm. J Clin Diagn Res 2014; 8:184-5. [DOI: 10.7860/jcdr/2014/7362.4194] [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] [Received: 08/12/2013] [Accepted: 01/23/2014] [Indexed: 11/24/2022]
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Yehya F, Chaudhary AK. Time resolved high frequency spectrum of Br2 molecules using pulsed photoacoustic technique. Spectrochim Acta A Mol Biomol Spectrosc 2013; 115:544-551. [PMID: 23871982 DOI: 10.1016/j.saa.2013.05.085] [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: 01/22/2013] [Revised: 05/15/2013] [Accepted: 05/24/2013] [Indexed: 06/02/2023]
Abstract
The paper reports the time resolved spectral distribution of higher order acoustic modes generated in Br2 molecules using pulsed Photoacoustic (PA) technique. New time resolved vibrational spectrum of Br2 molecules are recorded using a single 532nm, pulses of 7ns duration at 10Hz repetition rate obtained from Q-switched Nd:YAG laser. Frank-Condon principle based assignments confirms the presence of 12 numbers of (ν″-ν') vibrational transitions covered by a single 532+2nm pulse profile. Inclusions of higher order zeroth modes in Bassel's function expansion series shows the probability of overlapping of different types of acoustic modes in the designed PA cells. These modes appear in the form of clusters which occupies higher frequency range. The study of decay behavior of PA signal with respect to time confirms the photolysis of Br2 at 532nm wavelength. In addition, the shifting and clustering effect of cavity eigen modes in Br2 molecules have been studied between 1 and 10ms time scale. The estimated Q-factor of PA cell (l=16cm, R=1.4cm) is 145±4 at 27kHz frequency.
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Affiliation(s)
- Fahem Yehya
- Advanced Centre of Research in High Energy Materials, University of Hyderabad, Hyderabad 500 046, AP, India
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Chaudhary AK, Chaudhary A, Tiwari SC, Dwivedi R. Can community-based, low-cost antenatal care in the third trimester of pregnancy reduce the incidence of low birth weight newborns? J Obstet Gynaecol India 2013; 62:286-90. [PMID: 23730031 DOI: 10.1007/s13224-012-0217-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 12/15/2009] [Accepted: 05/28/2012] [Indexed: 10/28/2022] Open
Abstract
OBJECTIVE To determine if community-based, low-cost interventions during third trimester of pregnancy can reduce the incidence of low birth weight babies. METHODS In a case control study, 290 pregnant women from a slum area were registered in the beginning of third trimester of pregnancy and provided full antenatal care comprising fortnightly check up, one IFA tablet daily, counseling for minimum one-and-a-half hour post-lunch rest in left lateral position, additional diet to ensure minimum 2,200 kcal per day, and management of clinical conditions, if any. An equal number of pregnant women belonging to the same slum area were registered as control who received routine antenatal services from the existing health care facilities. The birth weight of the babies in the two groups were recorded and compared. Test of significance and correlation coefficient were applied to the data. RESULTS Mean birth weight of the babies of the Subjects was 2.76 kg (SD 0.39) compared to mean birth weight of 2.57 kg (SD 0.36) of the babies in the Control group. Incidence of low birth weight babies among subjects who consumed minimum 2,400 kcal per day, had one-and-a-half hour post-lunch rest in left lateral position and who consumed one tablet of IFA (100 mg iron and 5 mg folic acid) per day during the last trimester of pregnancy was lower (17.6 %) as compared with women in the Control group (36.2 %). The difference in the mean birth weight of newborns of the two groups was statistically significant (t = 2.52, p < 0.01). CONCLUSIONS Incidence of low birth weight babies can be significantly reduced by providing simple, low-cost care to pregnant women during the last trimester of pregnancy in the community setting.
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Affiliation(s)
- A K Chaudhary
- District Hospital, Bhopal, India ; Quarter No. 94/13-F, Tulsi Nagar, Bhopal, 462 003 India
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Angalena R, Prabitha KN, Chaudhary AK, Bashyam MD, Jain S, Dalal AB. A novel homozygous point mutation at codon 82 (HBB:c.247A > T) in the beta-globin gene leads to thalassemia major. Int J Lab Hematol 2010; 32:548-9. [PMID: 20136848 DOI: 10.1111/j.1751-553x.2009.01217.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Blair IA, Oe T, Kambouris S, Chaudhary AK. 1,3-butadiene: cancer, mutations, and adducts. Part IV: Molecular dosimetry of 1,3-butadiene. Res Rep Health Eff Inst 2000:151-90; discussion 211-9. [PMID: 10925841] [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: 02/17/2023] Open
Abstract
Analysis of N7-guanine adducts derived from 1,3-butadiene (BD) was conducted with use of liquid chromatography-mass spectrometry (LC-MS) in combination with stable isotope methods. The N7-guanine adducts were shown to undergo spontaneous depurination from DNA in vitro in both calf-thymus DNA and TK6-cell DNA. A comparison was made between BD-derived N7-guanine adduct concentrations both in liver DNA and urine of rats and mice exposed to BD. This has provided insight into the exposure of the animals to 1,2-epoxy-3-butene (BDO), 1,2,3,4-diepoxybutane (BDO2), and 1,2-dihydroxy-3,4-epoxybutane (BDO-diol), the three oxidative metabolites of BD thought to be responsible for BD-mediated carcinogenesis. The liver DNA of mice contained more of the two N7-guanine adducts of BDO--N7-2-hydroxy-3-butenyl-1-guanine (2HB1G) and N7-1-hydroxy-3-butenyl-2-guanine (1HB2G)--than the amounts in rats during the 10-day BD exposure and the 6 days after exposure that were monitored. An excess of 1HB2G over 2HB1G by a factor of approximately 10 in the rat liver and a factor of approximately 5 in the mouse liver was also observed. This regioselective difference was apparent during both the 10-day exposure and the 6 days after exposure. The half-lives of 2HB1G and 1HB2G were estimated as 4.3 days and 3.5 days, respectively, in the DNA of BD-exposed mice and rats. Higher amounts of 2HB1G and 1HB2G appeared in rat urine compared with mouse urine after the 10-day exposure to 1,250 ppm BD. Analysis of liver DNA for N7-guanine adducts derived from BDO2 revealed the presence of two diastereomeric forms of N7-(2,3,4-trihydroxybutyl)-1-guanine (THBG). One of the diastereomers [(+/-)-THBG] was formed by reaction of DNA with (+/-)-BDO2 or BDO-diol, and the other diastereomer (meso-THBG) was formed by reaction of DNA with meso-BDO2 or BDO-diol. There was more (+/-)-THBG and meso-THBG in liver DNA of mice compared with amounts in rats during the 10 days of BD exposure and the 6 days after exposure. A twofold excess of (+/-)-THBG over meso-THBG in rat liver was found at all of the time points monitored. After 10 days of exposure to BD, (+/-)-THBG in mouse liver was also present in an almost twofold excess over meso-THBG. At 6 days after exposure to BD, however, (+/-)-THBG and meso-THBG were present in almost equal amounts in mouse liver. Furthermore, amounts of the two THBG diastereomers in mouse liver 6 days after exposure to BD were almost fivefold greater than amounts in rat liver. The half-lives of (+/-)-THBG and meso-THBG appeared to be longer in mouse liver (4.1 days and 5.5 days, respectively) than in rat liver (3.6 days and 4.0 days, respectively). Higher amounts of (+/-)-THBG were excreted in rat urine compared with mouse urine. It is noteworthy that each of the N7-guanine adducts derived from BD was present in higher concentrations in the liver DNA of mice exposed to 1,250 ppm BD than in the liver DNA of rats exposed to the same dose. Conversely, each of the adducts was present in higher concentrations in the urine of rats compared with the urine of mice after exposure to 1,250 ppm BD.
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Affiliation(s)
- I A Blair
- Center for Cancer Pharmacology, University of Pennsylvania, Philadelphia 19104-6160, USA
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Abstract
A quantitative method was developed and validated for rapid and sensitive analysis of cimetidine in human plasma. The method involved the use of liquid chromatography (LC) coupled with atmospheric pressure chemical ionization (APCI) and selected reaction monitoring (SRM) mass spectrometry (MS). A cimetidine analog, SKF92374, was used as the internal standard. Separation of cimetidine and the internal standard was accomplished using a reverse-phase HPLC column (C18). The eluted components were ionized by the APCI source and subsequently detected by a highly selective triple quadrupole mass spectrometer in the SRM mode. Linear standard curves were obtained from 5 ng/mL (lower limit of quantitation) to 10,000 ng/mL. The results demonstrated excellent precision (%RSD 1. 1-8.9%) and accuracy (94.7-108.0%) over this range. In addition, the amount of plasma sample needed for analysis was small (50 muL), and the plasma pretreatment (analyte recovery >94%) was simple and time saving. This assay was used to evaluate cimetidine levels in premature infants following intravenous infusion of cimetidine.
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Affiliation(s)
- K Xu
- Center for Cancer Pharmacology, Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104-4318, USA
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Oe T, Kambouris SJ, Walker VE, Meng Q, Recio L, Wherli S, Chaudhary AK, Blair IA. Persistence of N7-(2,3,4-trihydroxybutyl)guanine adducts in the livers of mice and rats exposed to 1,3-butadiene. Chem Res Toxicol 1999; 12:247-57. [PMID: 10077487 DOI: 10.1021/tx980193s] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [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: 11/29/2022]
Abstract
Liquid chromatography (LC) in combination with tandem mass spectrometry (MS/MS) and stable isotope methodology was employed for the analysis of the N7-guanine (Gua) adducts derived from 1,2:3, 4-diepoxybutane (BDO2) a reactive metabolite of 1,3-butadiene (BD). Two diastereomeric forms of N7-(2,3,4-trihydroxybutyl)guanine (THBG) were identified in the livers of both mice and rats. One of the diastereomers [(+/-)-THBG] was formed by reaction of DNA with (+/-)-BDO2, and the other diastereomer (meso-THBG) was formed by reaction of DNA with meso-BDO2. There was significantly more (+/-)-THBG and meso-THBG in the liver DNA of the mice when compared with those of the rats during the 10 days of exposure to BD and the 6 days of postexposure that were monitored. There was a 2-fold excess of (+/-)-THBG over meso-THBG in the rat liver at all the time points. In the mouse liver after 10 days of exposure to BD, the (+/-)-THBG (3.9 adducts/10(6) normal bases) was also present in an almost 2-fold excess over meso-THBG (2.2 adducts/10(6) normal bases). However, 6-days after exposure to BD, (+/-)-THBG (1.2 adducts/10(6) normal bases) and meso-THBG (1.0 adduct/10(6) normal bases) were present in almost equal amounts in the mouse liver. Furthermore, there was an almost 5-fold excess of the two THBG diastereomers in the mouse liver DNA 6 days after exposure to BD when compared with rat liver DNA. The half-lives of (+/-)-THBG and meso-THBG appeared to be slightly longer in mouse liver (4.1 and 5.5 days, respectively) than in rat liver (3.6 and 4.0 days, respectively). The apparent persistence of these adducts in the mouse may contribute to the increased susceptibility of this species to BD-induced carcinogenesis. It is possible that (+/-)-THBG and meso-THBG could have also been derived from the reaction of DNA with the hydrolysis product of BDO2, 1,2-dihydroxy-3,4-epoxybutane (DHEB). Surprisingly, a vast majority of the studies in which the mutagenic and carcinogenic potential of BDO2 have been examined have only employed the commercially available (+/-)-BDO2. In light of the present findings, additional studies will be required to determine the potency of meso-BDO2 and the DHEB that is the precursor to meso-THBG as mutagens and carcinogens.
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Affiliation(s)
- T Oe
- Center for Cancer Pharmacology, University of Pennsylvania, 302 D Abramson Research Building, Civic Center Boulevard and Osler Circle, Philadelphia, Pennsylvania 19104-4318,USA
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Kim RB, Wandel C, Leake B, Cvetkovic M, Fromm MF, Dempsey PJ, Roden MM, Belas F, Chaudhary AK, Roden DM, Wood AJ, Wilkinson GR. Interrelationship between substrates and inhibitors of human CYP3A and P-glycoprotein. Pharm Res 1999; 16:408-14. [PMID: 10213372 DOI: 10.1023/a:1018877803319] [Citation(s) in RCA: 315] [Impact Index Per Article: 12.6] [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: 12/15/2022]
Abstract
PURPOSE CYP3A and P-gp both function to reduce the intracellular concentration of drug substrates, one by metabolism and the other by transmembrane efflux. Moreover, it has been serendipitously noted that the two proteins have many common substrates and inhibitors. In order to test this notion more fully, systematic studies were undertaken to determine the P-gp-mediated transport and inhibitory characteristics of prototypical CYP substrates. METHODS L-MDR1, LLC-PK1, and Caco-2 cells were used to evaluate established CYP substrates as potential P-gp substrates and inhibitors in vitro, and mdr1a deficient mice were used to assess the in vivo relevance of P-gp-mediated transport. RESULTS Some (terfenadine, erythromycin and lovastatin) but not all (nifedipine and midazolam) CYP3A substrates were found to be P-gp substrates. Except for debrisoquine, none of the prototypical substrates of other common human CYP isoforms were transported by P-gp. Studies in mdr1a disrupted mice confirmed that erythromycin was a P-gp substrate but the CYP3A-inhibitor ketoconazole was not. In addition, CYP3A substrates and inhibitors varied widely in their ability to inhibit the P-gp-mediated transport of digoxin. CONCLUSIONS These results indicate that the overlap in substrate specificities of CYP3A and P-gp appears to be fortuitous rather than indicative of a more fundamental relationship.
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Affiliation(s)
- R B Kim
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA.
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Abstract
Biocatalytic polytransesterification at high concentrations of monomers proceeds rapidly and is accompanied by an increase in the temperature of the reaction mixture due to liberation of heat of reaction during the initial phase. We have used principles of reaction calorimetry to monitor the kinetics of polymerization during this initial phase, thus relating the temperature to the extent of polymerization. Rate of polymerization increases with the concentration of monomers. This is also reflected by the increase in the temperature of the reaction mixture. Using time-temperature-conversion contours, a differential method of kinetic analysis was used to calculate the energy of activation ( approximately 15.1 Kcal/mol). Copyright 1998 John Wiley & Sons, Inc.
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Affiliation(s)
- AK Chaudhary
- Department of Chemical and Petroleum Engineering & Center for Biotechnology and Bioengineering, 1249 Benedum Hall, University of Pittsburgh, Pennsylvania 15261, USA
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Uppal A, Kapur A, Chaudhary AK, Sharma V. Pituitary tuberculoma. Neurol India 1998; 46:251. [PMID: 29508790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- A Uppal
- Advanced Diagnosis, Amritsar - 143 001, Punjab, India
| | - A Kapur
- Advanced Diagnosis, Amritsar - 143 001, Punjab, India
| | - A K Chaudhary
- Advanced Diagnosis, Amritsar - 143 001, Punjab, India
| | - V Sharma
- Advanced Diagnosis, Amritsar - 143 001, Punjab, India
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Niedernhofer LJ, Riley M, Schnetz-Boutaud N, Sanduwaran G, Chaudhary AK, Reddy GR, Marnett LJ. Temperature-dependent formation of a conjugate between tris(hydroxymethyl)aminomethane buffer and the malondialdehyde-DNA adduct pyrimidopurinone. Chem Res Toxicol 1997; 10:556-61. [PMID: 9168253 DOI: 10.1021/tx960191c] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [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: 02/04/2023]
Abstract
The stability of the major adduct formed between the endogenous product malondialdehyde (MDA) and deoxyguanosine, a pyrimidopurinone termed M1G-dR, was tested under a variety of conditions required for nucleic acid manipulation. M1G-dR was found to be stable at neutral pH and 37 degrees C but to be unstable when stored at -20 degrees C in the presence of Tris buffers. A new product with a characteristic absorption band at 350 nm was identified by 1H-NMR as an enamino-imine comprised of one molecule of Tris, one molecule of MDA, and deoxyguanosine. The formation of the conjugate was observed on reaction of Tris with M1G-dR or its ring-opened derivative N2-(3-oxo-1-propenyl)deoxyguanosine. The Tris-M1G-dR conjugate was unstable in aqueous solutions at room temperature, undergoing hydrolysis. However, the Tris conjugate of M1G base remained stable at room temperature in organic solvent. The isolation and properties of a conjugate between M1G-dR and Tris suggest that cross-links may form by reaction of MDA with DNA but they are likely to be unstable to hydrolysis.
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Affiliation(s)
- L J Niedernhofer
- Department of Biochemistry, Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA
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Bucco RA, Zheng WL, Davis JT, Sierra-Rivera E, Osteen KG, Chaudhary AK, Ong DE. Cellular retinoic acid-binding protein(II) presence in rat uterine epithelial cells correlates with their synthesis of retinoic acid. Biochemistry 1997; 36:4009-14. [PMID: 9092831 DOI: 10.1021/bi962094o] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [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: 02/04/2023]
Abstract
Vitamin A (retinol) and retinoic acid are necessary for the maintenance of the female reproductive system of higher animals. Our previous work has demonstrated cell specific expression of cellular retinoic acid-binding protein (CRABP) and cellular retinoic-acid binding protein(II) [CRABP(II)] in the uterus of the rat. CRABP(II) expression was shown to be induced in the uterine surface epithelial cells by treatment of prepubertal rats with pregnant mare serum gonadotropin (PMSG). Here we report that, after PMSG treatment, collected uteri had markedly higher levels of retinoic acid than did the uteri of prepubertal rats treated with the control vehicle. Smooth muscle, stromal, and epithelial cells were then cultured from uteri from such animals and provided with retinol or with the retinol/retinol-binding protein complex. Retinoic acid production, analyzed by high-performance liquid chromatography, was observed for the epithelial cells from the uteri of prepubertal animals treated with PMSG, cells previously shown to express CRABP(II) and confirmed here to continue to express it in culture. Little or no retinoic acid was produced by cultured epithelial cells from the prepubertal uteri [shown previously to be negative for CRABP(II)] or by smooth muscle and stromal cells taken from uteri of prepubertal or PMSG-treated rats (shown previously to express CRABP). Retinoic acid production by uterine epithelial cells [and CRABP(II) expression] was also observed if the prepubertal rat was treated with estrogen before cell collection. At no time did cells expressing CRABP exhibit significant retinoic acid synthesis. Thus, this system revealed an important difference in retinoid metabolism between cells expressing CRABP and CRABP(II) and suggests CRABP(II) may participate in retinoic acid production and/or secretion.
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Affiliation(s)
- R A Bucco
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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35
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Rouzer CA, Chaudhary AK, Nokubo M, Ferguson DM, Reddy GR, Blair IA, Marnett LJ. Analysis of the malondialdehyde-2'-deoxyguanosine adduct pyrimidopurinone in human leukocyte DNA by gas chromatography/electron capture/negative chemical ionization/mass spectrometry. Chem Res Toxicol 1997; 10:181-8. [PMID: 9049429 DOI: 10.1021/tx9601216] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.3] [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: 02/03/2023]
Abstract
A method is described for the assay of the major malondialdehyde-deoxyguanosine adduct (M1G) based on immunoaffinity purification and gas chromatography/electron capture/negative chemical ionization/mass spectrometry. A stable isotope of M1G-deoxyribose ([2H2]M1G-dR) was used as an internal standard. Recovery of internal standard throughout the entire assay procedure was approximately 40%. The assay showed a linear response over a range of 10-1000 pg of M1G-dR and was verified by analysis of a synthetic. M1G-containing oligomer. The limit of detection in biological samples was 100 fmol/sample, corresponding to 3 adducts/10(8) bases for 1 mg of DNA. DNA was isolated from the blood of 10 healthy human donors, and M1G levels were measured. A mean value of 6.2 +/- 1.2 adducts/10(8) bases was obtained, with no obvious differences bases on age or cigarette smoking. A small, but statistically significant difference was observed between the levels in females (5.1 +/- 0.4 adducts/10(8) bases) and males 6.7 +/- 1.1 adducts/10(8) bases). The presence of M1G in leukocyte DNA was further verified by analysis using liquid chromatography/electrospray ionization mass spectrometry.
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Affiliation(s)
- C A Rouzer
- A.B. Hancock Jr. Memorial Laboratory for Cancer Research, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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36
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Kambouris SJ, Chaudhary AK, Blair IA. Liquid chromatography/electrospray ionization tandem mass spectroscopy (LC/ESI MS/MS) analysis of 1,2-epoxybutene adducts of purine deoxynucleosides. Toxicology 1996; 113:331-5. [PMID: 8901920 DOI: 10.1016/0300-483x(96)03468-3] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Calf thymus DNA was reacted with 1,2-epoxybutene (BDO) in phosphate buffered saline at 37 degrees C for 12 h. DNA was ethanol precipitated and hydrolyzed with 1 M HCl to release DNA bases. Adenine (A)-BDO and guanine (Gua)-BDO adducts were analyzed in the ethanol supernatant and DNA hydrolysate using LC/ESI MS/MS. Reaction of BDO with A resulted in the formation of seven A-BDO adducts with MH+ ions at m/z 206. Two of these adducts were observed in the ethanol supernatant. In addition, two formaidopyrimidine (FAPY)-adducts were detected with MH+ ions at m/z 224 in DNA hydrolysate. These data are consistent with formation of regioisomeric N-7 or N-9 adducts which can be released by spontaneous depurination or ring opening. Four other A-BDO adducts were detected in DNA hydrolysate. Similar adducts were observed for Gua. This new methodology permits simultaneous determination of initially formed adducts as well as those arising as a consequence of depurination. The latter adducts provide the opportunity for monitoring exposure to BDO through analysis of N-7 or N-3 adducts excreted in the urine.
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Affiliation(s)
- S J Kambouris
- Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
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37
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Chaudhary AK, Reddy GR, Blair IA, Marnett LJ. Characterization of an N6-oxopropenyl-2'-deoxyadenosine adduct in malondialdehyde-modified DNA using liquid chromatography/electrospray ionization tandem mass spectrometry. Carcinogenesis 1996; 17:1167-70. [PMID: 8640930 DOI: 10.1093/carcin/17.5.1167] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [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: 02/01/2023] Open
Abstract
Malondialdehyde (MDA), a product of lipid peroxidation, causes mutations in bacterial and mammalian cells and cancer in rats. MDA reacts with deoxynucleosides in vitro and the monomeric adduct of MDA with deoxyguanosine (M1G-dR) is the major adduct. M1G-dR has been detected in rat and human liver. Random mutagenesis studies with MDA-modified DNA and recent 32P-postlabeling studies indicate that in addition to M1G-dR, adducts to deoxyadenosine may also be formed. We have utilized liquid chromatography coupled with electrospray ionization tandem mass spectrometry to characterize an N6-oxopropenyl-2'-deoxyadenosine adduct (M1A-dR) in calf DNA modified with MDA.
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Affiliation(s)
- A K Chaudhary
- A.B. Hancock Jr Memorial Laboratory for Cancer Research, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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38
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Chaudhary AK, Nokubo M, Reddy GR, Yeola SN, Morrow JD, Blair IA, Marnett LJ. Detection of endogenous malondialdehyde-deoxyguanosine adducts in human liver. Science 1994; 265:1580-2. [PMID: 8079172 DOI: 10.1126/science.8079172] [Citation(s) in RCA: 282] [Impact Index Per Article: 9.4] [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: 01/28/2023]
Abstract
Endogenous DNA adducts may contribute to the etiology of human genetic disease and cancer. One potential source of endogenous DNA adducts is lipid peroxidation, which generates mutagenic carbonyl compounds such as malondialdehyde. A sensitive mass spectrometric method permitted detection and quantitation of the major malondialdehyde-DNA adduct, a pyrimidopurinone derived from deoxyguanosine. DNA from disease-free human liver was found to contain 5400 adducts per cell, a frequency comparable to that of adducts formed by exogenous carcinogens.
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Affiliation(s)
- A K Chaudhary
- A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Vanderbilt University School of Medicine, Nashville, TN 37232-0146
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Chaudhary AK, Nokubo M, Marnett LJ, Blair IA. Analysis of the malondialdehyde-2'-deoxyguanosine adduct in rat liver DNA by gas chromatography/electron capture negative chemical ionization mass spectrometry. Biol Mass Spectrom 1994; 23:457-64. [PMID: 7918689 DOI: 10.1002/bms.1200230802] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Malondialdehyde (MDA), a product of lipid peroxidation, causes mutations in bacterial and mammalian cells and cancer in rats. MDA reacts with deoxynucleosides in vitro and the monomeric adduct of MDA with deoxyguanosine (M1G-dR) is the major adduct formed. We have developed a sensitive analytical method to characterize and quantify M1G-dR from biological matrices using gas chromatography/electron capture negative chemical ionization mass spectrometry (GC/ECNCI MS). Reduction of M1G-dR with sodium borohydride produced a dihydro derivative (H2-M1G-dR). This more stable analog had improved high-performance liquid chromatographic characteristics which facilitated its isolation from biological fluids. H2-M1G-dR was converted to a monopentafluorobenzyl derivative with simultaneous depurination; it was then converted to the corresponding t-butyldimethylsilyl derivative and analyzed by GC/ECNCI MS. (2H2)H2-M1G was used as internal standard. Quantitative analysis was carried out using selected ion monitoring of m/z 302 and m/z 304 where the limit of detection was 10 pg (30 fmol) injected on-column. The level of M1G-dR in normal rat liver was 5.2 +/- 0.2 modified bases per 10(7) bases (n = 6 rats).
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Affiliation(s)
- A K Chaudhary
- A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Vanderbilt University, Nashville, TN 37332
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40
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Abstract
Cranio-metaphyseal dysplasia in two brothers, aged fourteen and twelve, is reported. Both brothers presented with deafness, repeated episodes of cold and cough and mouth breathing. Striking craniofacial configuration consisted of hypertelorism, prominent glabella and zygomatic arches, mandibular prognathism and overgrowth of middle third of face. Both patients had genu valgum deformity. Low intelligence and poor scholastic performance present in both brothers were attributed to deafness. Radiographic features consisted of obtuse mandibular angle, defective dentition, sclerotic frontal sinuses, sclerotic mastoids and temporal bones. Splaying of metaphyses of long bones was associated with mild sclerosis. Mild degree of widening of ribs was also present. One brother also had hallux valgus deformity. The radiographic and clinical differentiation of cranio-metaphyseal dysplasia and metaphyseal dysplasia (Pyle's disease) is highlighted.
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Affiliation(s)
- D Gupta
- Department of Radiology, Banaras Hindu University, Varanasi, India
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41
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Kalra J, Rajput AH, Mantha SV, Chaudhary AK, Prasad K. Oxygen free radical producing activity of polymorphonuclear leukocytes in patients with Parkinson's disease. Mol Cell Biochem 1992; 112:181-6. [PMID: 1322491 DOI: 10.1007/bf00227575] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [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: 12/26/2022]
Abstract
Oxygen free radicals (OFRs) have been suggested in the pathogenesis of Parkinson's disease (PD). These free radicals exert their cytotoxic effect by peroxidation of lipid membrane resulting in the formation of malondialdehyde (MDA). Polymorphonuclear (PMN) leukocyte is one of the major sources of OFR. However, the oxygen free radical producing activity of PMN leukocytes in patients with PD is not known. We therefore studied the oxygen free radical producing activity of polymorphonuclear leukocytes and MDA levels in the serum of healthy subjects and in patients with Parkinson's disease. The oxygen free radical producing activity of PMN leukocytes in blood and the MDA content in serum were significantly higher in patients with Parkinson's disease than in healthy subjects. These results indicate a possible role of oxygen free radicals in the pathogenesis of Parkinson's disease.
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Affiliation(s)
- J Kalra
- Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Abstract
Cardiac dysfunction after cardiopulmonary bypass (CPB) has been reported by various investigators. Oxygen free radicals have been shown to depress cardiac function and contractility. To evaluate the possible role of oxygen free radicals (OFR) in post-pump cardiac dysfunction, measurements of cardiac function, OFR producing activity of polymorphonuclear (PMN) leukocytes (PMN chemiluminescence) and malondialdehyde (MDA), a lipid peroxidation product, in blood were made at induction of anesthesia (T1), before cross clamping of the aorta (T2), after closure of the chest (T3), and 24 hours postoperatively (T4) in 21 patients undergoing aortocoronary bypass surgery. The total OFR-derived chemiluminescence at T1, T2, T3, and T4 was 1590 +/- 156, 3169 +/- 338, 1972 +/- 214, and 2614 +/- 366 mv.min.10(6) PMN-1, respectively. Superoxide dismutase (SOD)-inhibitable chemiluminescence at T1, T2, T3, and T4 was 1214 +/- 129, 2674 +/- 328, 1752 +/- 215, and 2139 +/- 292 mv.min.10(6) PMN-1, respectively. Superoxide anion at T1, T2, T3, and T4 was 0.99 +/- 0.14, 1.30 +/- 0.17, 1.07 +/- 0.14, and 1.19 +/- 0.12 nmol.10(6) PMN-1.30 min-1, respectively. Blood MDA at T1, T2, T3, and T4 was 0.17 +/- 0.02, 0.25 +/- 0.03, 0.20 +/- 0.03, and 0.23 +/- 0.02 nmol/ml, respectively. OFR-derived and SOD inhibitable chemiluminescence, superoxide anion, and blood MDA increased significantly during CPB and postoperatively. There were decreases in the blood pressure and stroke volume, and increases in the central venous pressure, capillary wedge pressure, and heart rate during CPB and postoperatively. Cardiac output remained unchanged during this procedure. There was leukopenia during CPB.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K Prasad
- Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Abstract
Activation of polymorphonuclear (PMN) leukocytes is known to generate oxygen free radicals (OFR). However the fate of activated PMN leukocytes is not known. We investigated the OFR producing (chemiluminescence) activity and the survival of the activated PMN leukocytes. The study was divided into two groups. Group I, In vivo study (n = 7): zymosan (8.4 mg/kg) was administered intravenously in the anesthetized dogs and the blood samples were collected before and after 5, 15, 30, 60 and 120 min of zymosan administration. This group represents the in vivo pre-stimulated PMN leukocytes; Group II, In vitro study (n = 7): the blood were collected from dogs and further divided into two groups. Group A (n = 7): non-stimulated, without any added zymosan and group B (n = 7): zymosan was added to stimulate PMN leukocytes. Blood samples from group A and B were also collected at various time intervals similar to in vivo studies. Oxygen free radical producing activity of PMN leukocytes was monitored by measuring luminol-dependent chemiluminescence (CL). Opsonized zymosan was used to activate PMN leukocytes. The studies in which the PMN leukocytes were stimulated in in vivo, both oxygen derived free radicals and superoxide dismutase (SOD) inhibitable oxygen free radical CL decreased significantly for 60 min and tended to reach thereafter to the pre-stimulated values. The resting chemiluminescence (chemiluminescence without zymosan stimulation in the assay medium) increased significantly for 15 min reaching to pre-stimulated values at 30 min and thereafter. In in vitro studies, oxygen derived free radicals CL of pre-stimulated PMN leukocytes (Group B) was depressed for the whole duration of investigation while SOD inhibitable CL was depressed for only 60 min. There was approximately a two-fold increase in the resting CL within 5 min of PMN leukocyte activation and it remained high for the whole duration of study. The chemiluminescence of non-stimulated PMN leukocytes in vitro (group A) remained practically normal throughout the period of observation. In in vivo studies, total white blood cells (WBC) and PMN leukocyte counts decreased initially and tended to approach towards pre-stimulated values at the end of the protocol. There were no changes in these counts in in vitro studies. These results indicate that the capacity to generate OFR is decreased in the in vivo and in vitro pre-stimulated PMN leukocytes. However this activity recovers with time. This study also suggests that the activated PMN leukocytes are not destroyed.
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Affiliation(s)
- K Prasad
- Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Kalra J, Chaudhary AK, Prasad K. Increased production of oxygen free radicals in cigarette smokers. Int J Exp Pathol 1991; 72:1-7. [PMID: 1888662 PMCID: PMC2002262] [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: 12/29/2022] Open
Abstract
Oxygen free radicals are known to produce damage in many biological tissues. Cigarette smoking is a major risk factor for various diseases. It is possible that oxygen free radical producing activity of polymorphonuclear (PMN) leucocytes is increased by cigarette smoking. We studied the oxygen free radical producing (luminol-dependent chemiluminescent) activity of PMN leucocytes in blood and the malondialdehyde (lipid peroxidation product) content of blood and serum in nonsmokers and smokers. The zymosan-induced chemiluminescent activity was measured on a LKB 1251 luminometer. The malondialdehyde (MDA) was measured as thiobarbituric acid (TBA) reactive substances. The chemiluminescent activity due to oxygen-derived free radicals (superoxide anion, hydrogen peroxide, hydroxyl radical) and superoxide dismutase (SOD)-inhibitable (superoxide anion) in nonsmokers were 1215.1 +/- 91.1 and 849.3 +/- 72.3 mV min/10(6) PMN leucocytes respectively. There was a significant increase in the oxygen-derived free radicals and SOD-inhibitable chemiluminescence in smokers. The values of blood and serum MDA were 171.7 +/- 6.1 and 222.2 +/- 5.6 nmoles/l respectively in nonsmokers. There was an increase in both blood and serum MDA in smokers. These results suggest that the increased generation of oxygen free radicals by PMN leucocytes might be responsible for an enhanced risk of various diseases related to cigarette smoking.
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Affiliation(s)
- J Kalra
- Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Abstract
We investigated the effect of acidic environment, hypoxia and oxygen free radicals on the release of beta-glucuronidase from rat liver lysosomes. A lysosomal enriched fraction from the homogenate of rat liver was prepared, using differential centrifugation technique. Exogenous oxygen free radicals were generated using xanthine-xanthine oxidase system. The release of beta-glucuronidase activity was measured from the lysosomes. The lysosomal fraction was exposed to various pH (8.0, 7.4, 6.5, 6.0, 5.5) and pO2 (454, 172, 96, 57,34 mm Hg) separately or to a combination of low pH (5.5, 6.5) and low pO2 (34, 57 mm Hg). The changes in pH or pO2 separately did not cause any increase in the release of beta-glucuronidase activity. The presence of oxygen free radicals at each pH or pO2 resulted in about a 3-fold increase in the release of beta-glucuronidase. A combination of very low pO2 and pH (pO2 (mm Hg)/pH; 34/5.5, 34/6.5) resulted in an increased release of beta-glucuronidase from lysosomes. Oxygen free radicals in the presence of both low pO2 and pH resulted in a further increase in the release of beta-glucuronidase. These data indicate that oxygen free radicals and not the alterations in pH and/or pO2 are primarily responsible for the disruption of lysosomes.
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Affiliation(s)
- J Kalra
- Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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46
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Prasad K, Kalra J, Chaudhary AK, Debnath D. Effect of polymorphonuclear leukocyte-derived oxygen free radicals and hypochlorous acid on cardiac function and some biochemical parameters. Am Heart J 1990; 119:538-50. [PMID: 2155522 DOI: 10.1016/s0002-8703(05)80276-5] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.2] [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: 12/30/2022]
Abstract
Polymorphonuclear (PMN) leukocyte activation is known to result in the production and release of oxygen free radicals and hypochlorous acid. Various clinical conditions are associated with PMN leukocyte stimulation. The present investigation deals with the effects of stimulated PMN leukocytes in the absence and in the presence of scavengers of oxygen free radicals (superoxide dismutase, catalase), hypochlorous acid quencher (methionine), and myeloperoxidase inhibitor (azide) on cardiac function and contractility; blood lactate, gases, and pH levels, blood and cardiac tissue malondialdehyde; and PMN leukocyte chemiluminescence activity in anesthetized dogs. Opsonised zymosan was used for stimulation of PMN leukocytes, and the effects were observed for 2 hours. The dogs were divided into four groups: group I, zymosan; group II, superoxide dismutase + catalase + zymosan; group III, methionine + zymosan; group IV, azide + methionine + zymosan. Zymosan produced a decrease in cardiac function and in indices of myocardial contractility and an increase in systemic and pulmonary vascular resistance. There was a decrease in blood pH and in PMN leukocyte chemiluminescense and an increase in the blood lactate and malondialdehyde. Superoxide dismutase plus catalase and methionine reduced the effect of zymosan on cardiac function and contractility and on blood malondialdehyde, lactate, and pH. The combination of azide and methionine did not prevent the deleterious effects of zymosan on cardiac function and contractility. Cardiac tissue malondialdehyde levels were lower in groups III and IV than in groups I and II which had values similar to each other. Methionine was superior to superoxide dismutase plus catalase in the prevention of the deleterious effects of PMN leukocyte stimulation on the various measured parameters. These results suggest that oxygen free radicals and hypochlorous acid are cardiac depressants and increase systemic and pulmonary vascular resistance in addition to causing tissue damage. Clinical situations with PMN stimulation may result in cardiac depression. The oxygen free radical scavenger and hypochlorous acid quencher may be beneficial in the counteraction of the deleterious effects of PMN leukocyte stimulation on the hemodynamic parameters and cellular integrity.
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Affiliation(s)
- K Prasad
- Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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47
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Abstract
We investigated the effect of exogenous oxygen free radicals and various pH on the release of lysosomal hydrolases from dog myocardial lysosomes. A lysosomal enriched fraction from the homogenate of dog heart was prepared, using differential centrifugation technique. Exogenous oxygen free radicals were generated using xanthine-xanthine oxidase system. The release of lysosomal hydrolases was measured from the lysosomal enriched fraction. There was about 3-fold increase in the release of cathepsin D and beta-N-acetylglucosaminidase activities in the preparations treated with xanthine-xanthine oxidase as compared to those without such treatment. The presence of superoxide dismutase, an oxygen free radical scavenger, prevented the release of cathepsin D and beta-N-acetylglucosaminidase from the lysosomes. Sonication and lubrol treatments, which are known to cause membrane disruption, also induced the release of these enzymes from lysosomal enriched fraction. However, this release was not prevented by superoxide dismutase. The changes in pH (4.5, 5.5, 6.0, 6.5, 7.4, 8.0) alone did not cause any increase in the enzyme release. The presence of oxygen free radicals at each pH resulted in a similar increase in the release of cathepsin D and beta-N-acetylglucosaminidase. These studies suggest that oxygen free radicals and not the alterations in pH are primarily responsible for the release of lysosomal hydrolases. Oxygen free radicals, in addition to their direct myocardial damaging effect, may also be responsible for the cardiac damage through the release of lysosomal enzymes.
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Affiliation(s)
- J Kalra
- Department of Pathology and Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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48
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Abstract
Oxygen free radicals (OFR) have been implicated as a causative factor of cell damage in several pathologic conditions. It is possible that OFR could have effects on cardiac function and contractility. The present investigation deals with the effects of OFR in the absence and in the presence of scavangers of OFR (superoxide dismutase and catalase) on cardiac function, index of cardiac contractility, serum creatine kinase (CK), and blood lactate, PO2 and pH in the anesthetized dogs. The hemodynamic measurements and collection of blood samples for measurement of CK, lactate, PO2 and pH were made before and at various intervals after administration of OFR for 1 hour. Xanthine and xanthine oxidase were used to generate OFR. OFR produced a decrease in cardiac function and indices of myocardial contractility and an increase in the serum CK. OFR produced an increase in the systemic and pulmonary vascular resistance. Although there was a tendency for an increase in the blood lactate, the increase was not significant. The blood PO2 and pH were not affected. Superoxide dismutase (SOD), alone or in combination with catalase, tended to protect cardiac function against the deleterious effects of OFR. Scavangers of OFR prevented the OFR-induced rise in serum CK. Although the protective effect of SOD plus catalase was slightly better than SOD alone, the results were not significantly different from each other. These results suggest that OFR are cardiac depressant and increase the peripheral vascular resistance besides causing cellular damage. Scavangers of OFR may be beneficial in counteracting the deleterious effects of OFR on hemodynamic parameters and cellular integrity.
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Affiliation(s)
- K Prasad
- Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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49
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Chaudhary AK, Bhatnagar HN, Bhatnagar LK, Chaudhary K. Comparative study of the effect of drugs and relaxation exercise (yoga shavasan) in hypertension. J Assoc Physicians India 1988; 36:721-3. [PMID: 3069839] [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: 01/04/2023]
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50
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Chaudhary AK, Hubbard JW, McKay G, Midha KK. Identification of a quaternary ammonium-linked glucuronide of chlorpromazine in the urine of a schizophrenic patient treated with chlorpromazine. Drug Metab Dispos 1988; 16:506-8. [PMID: 2900749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- A K Chaudhary
- College of Pharmacy, University of Saskatchewan, Saskatoon, Canada
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