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Prakash M, Balamurugan M, Parthasarathi K, Gunasekaran G, Cooper EL, Ranganathan LS. Anti-ulceral and anti-oxidative properties of "earthworm paste" of Lampito mauritii (Kinberg) on Rattus Norvegicus. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2007; 11:9-15. [PMID: 17405344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Studies have been made to understand the anti-ulceral and anti-oxidant properties of the "earthworm paste" derived from Lampito mauritii (Kinberg), an indigenous species, in comparison with the standard anti-ulceral drug-ranitidine, on the Wistar strain albino rats Rattus norvegicus. Administration of 200 mg/kg aspirin was found to increase the volume of gastric juice secretion, total acidity, free acidity, ulcer index and reduce the pH. It also had decreased the anti-oxidant levels such as reduced glutathione, glutathione peroxidase, catalase, superoxide dismutase and increased the level of thiobarbituric acid reactive substances. Pretreatment with the standard drug-ranitidine (50 mg/kg) and different doses of "earthworm paste" (20, 40, 80, 160 and 320 mg/kg) in ulcer induced animal had enhanced the pH, decreased the volume of gastric juice, free acidity, total acidity and reduced the ulcer index. Further the activities of reduced glutathione, glutathione peroxidase, catalase, superoxide dismutase were increased whereas the thiobarbituric acid reactive substance had decreased. The results were more significant in rats administered with 160 mg/kg "earthworm paste" than the application of ranitidine and other doses of "earthworm paste". This indicates the presence of antiulcer and anti-oxidative effects in "earthworm paste". In conclusion, administration of 160 mg "earthworm paste"/kg was found to have better therapeutic properties.
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Gomme PT, Prakash M, Hunt B, Stokes N, Cleary P, Tatford OC, Bertolini J. Effect of lobe pumping on human albumin: development of a lobe pump simulator using smoothed particle hydrodynamics1. Biotechnol Appl Biochem 2006; 43:113-20. [PMID: 16246177 DOI: 10.1042/ba20050188] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Using SPH (smoothed particle hydrodynamics), the motion of a lobe pump under load was simulated in order to predict the level of shear stress experienced by a protein solution. By varying the gap size between the lobes and pump housing, variations in pump efficiency and shear stress were determined. The simulations indicated that pump shear was dependent on gap size, with shear stress levels (0-40 Pa) correlating with those estimated in previous albumin-pumping studies. As gap size increased, the number of fluid particles experiencing low shear (<10 Pa) increased, whereas those experiencing high shear (>20 Pa) showed a decreasing trend. The pump efficiency, however, decreased with gap size, requiring more lobe revolutions to pass a unit volume. Taken together, these observations indicate that lobe pumps operated with increased gaps between the rotors and the housing result in larger number of particles within the fluid experiencing shear stresses. Moreover, the simulations indicate that it is best to use larger lobe pumps operated at high efficiency to transfer protein-containing solutions.
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Sinnott M, Cleary P, Prakash M. Influence of elastic walls on the flow dynamics in a carotid artery using Smoothed Particle Hydrodynamics. J Biomech 2006. [DOI: 10.1016/s0021-9290(06)84796-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kumar R, Prakash M, Jha S. Paradoxical response to chemotherapy in neurotuberculosis. Pediatr Neurosurg 2006; 42:214-22. [PMID: 16714861 DOI: 10.1159/000092357] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2005] [Accepted: 10/21/2005] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Our objective was to investigate the paradoxical response and the factors responsible for such an uncommon (but known) response to chemotherapy in neurotuberculosis. MATERIAL AND METHODS Ten children with intracranial tuberculomas/neurotuberculosis were retrospectively studied, who were on regular antituberculous chemotherapy. Any deterioration of the neurological condition, increase in the size of the lesion or appearance of new lesions was studied clinically and radiologically during the follow-up period. RESULTS An atypical response to chemotherapy was observed from 3 weeks to 1 year of chemotherapy. Four of the 10 children, who were receiving chemotherapy for either post-tubercular meningitis (TBM), hydrocephalus (2) or TBM (2), developed multiple granulomas in 3 and hydrocephalus in 1 case. The remaining 6 children who were diagnosed to have granulomas at their presentation deteriorated at the follow-up despite regular chemotherapy. CT scans were repeated in 7 of 10 cases at the time of neurological deterioration, out of which 5 children showed appearance of new granulomas or abscess(es) and 2 showed an increase in the size of their preexisting granulomas. One patient with faintly enhancing granulomas in the posterior fossa responded to an additional use of steroids. The remaining 9 patients required surgical intervention on account of their neurological deterioration. CONCLUSIONS (1) Paradoxical responses to intracranial tuberculoma/neurotuberculosis can occur at any time even up to 1 year during chemotherapy despite a regular standard antitubercular treatment. (2) New granuloma(s) or abscess(es) may appear in children receiving chemotherapy for TBM during the follow-up. (3) Hydrocephalus may also appear despite a regular chemotherapy in treated TBM cases. (4) Immature faintly enhancing tuberculomas have a more likely chance of resolution with antituberculous chemotherapy and glucocorticoids, while a well-formed and probably large-sized (>3 cm) granuloma may have a risk of paradoxical enlargement.
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Gupta RK, Prakash M, Mishra AM, Husain M, Prasad KN, Husain N. Role of diffusion weighted imaging in differentiation of intracranial tuberculoma and tuberculous abscess from cysticercus granulomas-a report of more than 100 lesions. Eur J Radiol 2005; 55:384-92. [PMID: 16129246 DOI: 10.1016/j.ejrad.2005.02.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Revised: 02/08/2005] [Accepted: 02/10/2005] [Indexed: 10/25/2022]
Abstract
Restricted diffusion is noted in a large number of non-stroke conditions including tuberculoma. The purpose of this study was to demonstrate spectrum of diffusion weighted imaging (DWI) abnormalities in tuberculomas and tuberculous abscess and to distinguish these from degenerating neurocysticercosis. Seventy tuberculomas and tuberculous abscesses in 30 patients were categorized in three groups depending on the intensity in the core of the lesion on T2 weighted images. Mean apparent diffusion coefficient (ADC) was calculated from the core as well as from the wall of the lesions. Forty-five lesions of neurocysticercosis in different stage of evolution in 12 patients were also included for comparison. The mean ADC value from the core of the T2 hypointense lesions was significantly higher compared to the wall ((1.24+/-0.32)x10(-3) and (1.06+/-0.15)x10(-3)mm(2)/s, respectively), while mean ADC value from the core of mildly T2 hyperintense lesions was significantly lower compared to the wall ((0.80+/-0.08)x10(-3) and (1.08+/-0.13)x10(-3)mm(2)/s, respectively). Truly T2 hyperintense lesions were divided into two subgroups, tuberculomas and tuberculous abscesses; ADC values from the core and the wall of these lesions were (0.74+/-0.13)x10(-3), (0.61+/-0.08)x10(-3) and (1.03+/-0.14)x10(-3), (1.08+/-0.14)x10(-3)mm(2)/s, respectively, and was significantly lower in core as compared to the wall. However, there was no significant difference between ADC values of the tuberculous abscess and the hyperintense tuberculomas. Vesicular and degenerating stages of cysticercus cysts from the core showed ADC values of (1.66+/-0.29)x10(-3) and (1.51+/-0.23)x10(-3)mm(2)/s, respectively, and were significantly higher than the core of all groups of tuberculomas and tuberculous abscess. We conclude that addition of DWI to routine imaging protocol may help in differentiation of tuberculous lesions from degenerating cysticercus granuloma.
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Saxena S, Prakash M, Kumar S, Gupta RK. Comparative evaluation of magnetization transfer contrast and fluid attenuated inversion recovery sequences in brain tuberculoma. Clin Radiol 2005; 60:787-93. [PMID: 15978890 DOI: 10.1016/j.crad.2004.09.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Revised: 09/10/2004] [Accepted: 09/20/2004] [Indexed: 11/16/2022]
Abstract
AIM To compare T1-weighted magnetization transfer (MT) with fluid attenuated inversion recovery (FLAIR) imaging for evaluating conspicuity and number of lesions in individuals with brain tuberculoma. MATERIALS AND METHODS In all 28 patients with brain tuberculoma underwent MR examination using fast spin-echo (FSE) T2, spin-echo (SE) T1, T1-weighted MT and FLAIR imaging. Post-contrast T1-weighted MT imaging was taken as the gold standard for assessing the number of lesions. Tuberculomas detected both on T1-weighted MT and FLAIR imaging were examined for the wall to be defined, and were divided into two groups on the basis of presence (group 1) or absence (group 2) of perilesional oedema visible on FLAIR imaging. The mean signal intensity of the wall of the lesions and adjacent oedema or brain parenchyma was analyzed qualitatively and quantitatively. RESULTS The number of lesions detected on T1-weighted MT was higher than on FLAIR imaging (209 versus 163). Conspicuity in both groups was better on T1-weighted MT images qualitatively as well as quantitatively. The difference in the signal intensity of the wall of the lesion and perilesional oedema was statistically significant only on T1-weighted MT images in group 1 (p=0.0003 versus 0.3), whereas in group 2 it was statistically significant both on T1-weighted MT and FLAIR imaging (p=0.009 versus 0.05). CONCLUSION FLAIR imaging is not helpful in the examination of brain tuberculomas compared with T1-weighted MT imaging, as it neither contributes to the characterization of lesion nor assesses the true disease load.
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Prakash M, Upadhya S, Prabhu R. Protein thiol oxidation and lipid peroxidation in patients with uraemia. Scand J Clin Lab Invest 2005; 64:599-604. [PMID: 15370466 DOI: 10.1080/00365510410002869] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Patients with uraemia are exposed to increased oxidative stress. In this study, a series of oxidative stress markers were measured in patients with chronic renal failure (CRF) and patients with CRF on haemodialysis (HD) compared to normal controls to establish whether there is enhanced oxidative stress on HD therapy in uraemic subjects. METHODS Protein thiol oxidation, lipid hydroperoxides, albumin and uric acid concentrations were estimated in patients receiving HD and patients with CRF and compared with those in healthy controls. RESULTS There was a significant decrease in the level of protein thiols in CRF (p = 0.0001) and HD patients (p = 0.0001) compared with that in controls. Lipid hydroperoxides were significantly higher in CRF (p = 0.026) and HD patients (p = 0.003) than in controls. However, there was no significant difference in protein thiols and lipid hydroperoxides between CRF and HD patients. Serum protein thiols correlated negatively with lipid hydroperoxides and positively with serum albumin. CONCLUSIONS These findings suggest that both CRF and HD patients have increased plasma protein oxidation and lipid peroxidation. However, HD therapy per se did not contribute to oxidative stress already present in uraemia. Owing to the variability in lipid peroxidation products as markers of oxidative stress and the vital role played by thiol antioxidants in the biological system, it is suggested that protein thiol oxidation may be a better marker of oxidative stress.
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Abstract
OBJECTIVE This study was performed to evaluate the role of diffusion-weighted imaging (DWI) in the diagnosis of Japanese encephalitis (JE) and to look for any relationship of the apparent diffusion coefficient (ADC) values with duration of the illness. METHODS We performed DWI in fourteen patients of JE. T2 weighted (T2W) and DWI were compared for number and location of lesions in all patients. Based on imaging patients were divided in three groups: group 1 (n=9) showing more lesions on DWI compared with T2W images, group 2 (n=3) with equal number of lesions on T2W and DWI and group 3 (n=2) with lesions more pronounced on T2W than DWI. ADC values were computed for all the lesions. The time interval between onset of neurologic signs/symptoms and MRI were charted and correlated with ADC values. RESULTS DWI was helpful in making early diagnosis of JE by showing characteristic involvement of bilateral thalami in four patients. Nine out of fourteen patients showed additional lesions on DWI. ADC from lesions in groups I, II and III measured 0.648 +/- 0.099 x 10 mm/s, 0.739 +/- 0.166 x 10 mm/s and 1.123 +/- 0.185 x 10 mm/s respectively. The ADC from the lesions in group 1 was significantly lower compared with group 2 (P value <0.05) while it was higher in group 3 lesions compared with the other two groups. There was a significant direct correlation of ADC values with the disease duration in these cases (r=0.847, P <0.01). CONCLUSIONS DWI is helpful in early diagnosis and characterization of the duration of the lesions in JE.
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Cleary PW, Prakash M. Discrete-element modelling and smoothed particle hydrodynamics: potential in the environmental sciences. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2004; 362:2003-2030. [PMID: 15306427 DOI: 10.1098/rsta.2004.1428] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Particle-based simulation methods, such as the discrete-element method and smoothed particle hydrodynamics, have specific advantages in modelling complex three-dimensional (3D) environmental fluid and particulate flows. The theory of both these methods and their relative advantages compared with traditional methods will be discussed. Examples of 3D flows on realistic topography illustrate the environmental application of these methods. These include the flooding of a river valley as a result of a dam collapse, coastal inundation by a tsunami, volcanic lava flow and landslides. Issues related to validation and quality data availability are also discussed.
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Abstract
Neutron stars are some of the densest manifestations of massive objects in the universe. They are ideal astrophysical laboratories for testing theories of dense matter physics and provide connections among nuclear physics, particle physics, and astrophysics. Neutron stars may exhibit conditions and phenomena not observed elsewhere, such as hyperon-dominated matter, deconfined quark matter, superfluidity and superconductivity with critical temperatures near 10(10) kelvin, opaqueness to neutrinos, and magnetic fields in excess of 10(13) Gauss. Here, we describe the formation, structure, internal composition, and evolution of neutron stars. Observations that include studies of pulsars in binary systems, thermal emission from isolated neutron stars, glitches from pulsars, and quasi-periodic oscillations from accreting neutron stars provide information about neutron star masses, radii, temperatures, ages, and internal compositions.
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Stauffer PR, Rossetto F, Prakash M, Neuman DG, Lee T. Phantom and animal tissues for modelling the electrical properties of human liver. Int J Hyperthermia 2003; 19:89-101. [PMID: 12519714 DOI: 10.1080/0265673021000017064] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The dielectric properties of human liver were characterized over the frequency range of 0.3-3 GHz for freshly excised tissue samples of primary hepatocellular carcinoma, metastatic colorectal carcinoma, and normal liver tissues resected from the tumour margin. On average, the dielectric constant (epsilon(r)) of freshly excised human liver tumour was 12% higher than that of surrounding normal liver, and the electrical conductivity (sigma) of tumour was 24% higher. In order to establish suitable tissue models for human liver, the electrical properties were compared to measurements of homogenous phantom mixtures, in vitro bovine liver, and in vivo canine and porcine liver tissues. The data demonstrate that there are several animal tissues that can be used to model the average dielectric properties of human liver reasonably accurately, and use of the most readily available bovine liver appears well-justified, even when stored for up to 10 days in a refrigerator. Additionally, the dielectric properties of in vitro liver remained stable over a large temperature range, with sigma rising only 1.1%/ degrees C in porcine liver (15-37 degrees C) and 2.0%/ degrees C in bovine liver (10-90 degrees C), and epsilon(r) decreasing < or =0.2%/ degrees C in both tissues. This effort identifies homogeneous solid and liquid phantom models and several heterogeneous in vitro tissues that adequately model the dielectric properties of human liver tumours for use in quantitative studies of microwave power deposition in liver.
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Myers J, Prakash M, Froelicher V, Do D, Partington S, Atwood J. Exercise capacity and mortality among men referred for exercise testing. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1062-1458(02)00697-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Prakash M, Patterson S, Kapembwa MS. Evaluation of the cervical cytobrush sampling technique for the preparation of CD45+ mononuclear cells from the human cervix. J Immunol Methods 2001; 258:37-46. [PMID: 11684121 DOI: 10.1016/s0022-1759(01)00464-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A cytobrush technique developed to prepare mononuclear cells from the intraepithelial layer of the endocervix has been evaluated. Specimens yielded approximately 4-6x10(6) cells, of which 10-15% were CD45+. Between 10% and 15% of these CD45+ cells were mononuclear leukocytes. The non-leukocyte cell fraction exhibited high levels of autofluorescence and for flow cytometry analysis, it was necessary to exclude these cells by gating. Macrophages constituted approximately 60% and T lymphocytes, 40% of the mononuclear cells in cytobrush samples. The CD4/CD8 T-cell ratio was similar to that observed in blood. In 9 of 13 specimens, B lymphocytes constituted less than 1% of the mononuclear cell fraction suggesting that the mononuclear cells were derived from the intraepithelial compartment rather then the deeper lamina propria. Lack of B lymphocytes also indicates minimal blood contamination in these samples, a conclusion supported by labelling for the red blood cell (RBC) glycoprotein glycophorin A. However, the need to monitor all samples for possible blood contamination was indicated by 4 of 13 samples in which B lymphocytes accounted for 2-8% of the mononuclear cells.
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Shetler K, Marcus R, Froelicher VF, Vora S, Kalisetti D, Prakash M, Do D, Myers J. Heart rate recovery: validation and methodologic issues. J Am Coll Cardiol 2001; 38:1980-7. [PMID: 11738304 DOI: 10.1016/s0735-1097(01)01652-7] [Citation(s) in RCA: 335] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES The goal of this study was to validate the prognostic value of the drop in heart rate (HR) after exercise, compare it to other test responses, evaluate its diagnostic value and clarify some of the methodologic issues surrounding its use. BACKGROUND Studies have highlighted the value of a new prognostic feature of the treadmill test-rate of recovery of HR after exercise. These studies have had differing as well as controversial results and did not consider diagnostic test characteristics. METHODS All patients were referred for evaluation of chest pain at two university-affiliated Veterans Affairs Medical Centers who underwent treadmill tests and coronary angiography between 1987 and 1999 as predicted after a mean seven years of follow-up. All-cause mortality was the end point for follow-up, and coronary angiography was the diagnostic gold standard. RESULTS There were 2,193 male patients who had treadmill tests and coronary angiography. Heart rate recovery at 2 min after exercise outperformed other time points in prediction of death; a decrease of <22 beats/min had a hazard ratio of 2.6 (2.4 to 2.8 95% confidence interval). This new measurement was ranked similarly to traditional variables including age and metabolic equivalents but failed to have diagnostic power for discriminating those who had angiographic disease. CONCLUSIONS Heart rate at 1 or 2 min of recovery has been validated as a prognostic measurement and should be recorded as part of all treadmill tests. This new measurement does not replace, but is supplemental to, established scores.
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Elkayam U, Prakash M, Subbiah S, Mehdi S, Nikitina A, Akhter W. Endothelial function in patients with chronic heart failure. J Cardiovasc Pharmacol 2001; 38 Suppl 2:S47-8. [PMID: 11811377 DOI: 10.1097/00005344-200111002-00012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Congestive heart failure is characteristically associated with systemic vasoconstriction and impaired vasodilatory capacity, leading to decreased peripheral perfusion. Factors identified as possible causes of reduced vasodilatory capacity include activation of the sympathetic nervous system and the renin-angiotensin system, vascular stiffness due to increased sodium and fluid retention, and structural vascular changes. More recently, the role of the endothelium as a mediator of vasoregulation and tissue perfusion has been recognized.
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Prakash M, Kapembwa MS, Gotch F, Patterson S. Higher levels of activation markers and chemokine receptors on T lymphocytes in the cervix than peripheral blood of normal healthy women. J Reprod Immunol 2001; 52:101-11. [PMID: 11600181 DOI: 10.1016/s0165-0378(01)00114-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Heterosexual transmission of human immunodeficiency virus (HIV-1) is the predominant mode of infection world-wide. To better understand sexual transmission of HIV-1 in women we have analysed virus co-receptor and cellular activation marker expression on T lymphocyte subsets from the cervical epithelium and have made comparisons with peripheral blood T cells. Intraepithelial cervical T lymphocytes were obtained with a cytobrush, immunolabelled and analysed by flow cytometry. Activation markers (CD69, CD25 and HLA-DR) were found to be more highly expressed on cervical than on blood T lymphocytes. These higher levels of activation on cervical T lymphocyte subsets could facilitate HIV-1 infection. CXCR4 was expressed at marginally higher levels than CCR5 on T cells from the cervical epithelium and peripheral blood. Thus, the preferential transmission of macrophage tropic strains of HIV-1 following sexual contact cannot be explained solely on the expression of chemokine co-receptors by T lymphocyte subsets.
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Prakash M, Patterson S, Kapembwa MS. Macrophages are increased in cervical epithelium of women with cervicitis. Sex Transm Infect 2001; 77:366-9. [PMID: 11588284 PMCID: PMC1744354 DOI: 10.1136/sti.77.5.366] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Sexually transmitted diseases (STIs) are major causes of morbidity in women. The mechanisms involved in establishment of genital mucosal infection are poorly defined. OBJECTIVE To investigate changes in cervical epithelial (CE) CD45+ cell subpopulations in women with microscopic evidence of cervicitis (n=9) and those without (n=12). METHODS CE samples were obtained using cytobrush including matched venous blood. CE and peripheral blood (PB) mononuclear cells were analysed by flow cytometry for CD3+, CD4+, CD8+, CD14+,CD19+, and HLA-DR+ expression. RESULTS Women with cervicitis had increased CE macrophages compared with those without (p<0.05). MHC class II+ cells were predominant in all cervical samples. Considerably fewer B lymphocytes were found in cervical samples in both groups of women. No changes were observed in cervical T lymphocyte subsets. However, a relative CD8+ lymphocytosis in PB was noted in women with cervicitis. CONCLUSION The increased numbers of CE macrophages in women with cervicitis may have important implications for pathogenesis of STIs including human immunodeficiency virus infection.
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Prakash M, Myers J, Froelicher VF, Marcus R, Do D, Kalisetti D, Atwood JE. Clinical and exercise test predictors of all-cause mortality: results from > 6,000 consecutive referred male patients. Chest 2001; 120:1003-13. [PMID: 11555539 DOI: 10.1378/chest.120.3.1003] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
OBJECTIVE To report the prevalence of abnormal treadmill test responses and their association with mortality in a large consecutive series of patients referred for standard exercise tests, with testing performed and reported in a standardized fashion. BACKGROUND Exercise testing is widely performed, but few databases exist of large numbers of consecutive tests performed on patients referred for routine clinical purposes using standardized methods. Even fewer of the available databases have information regarding all-cause mortality as an outcome. METHODS All patients referred for evaluation at two university-affiliated Veterans Affairs medical centers who underwent exercise treadmill testing for clinical indications between 1987 and 2000 were determined to be dead or alive using the Social Security death index after a mean 6.2 years (median, 7 years) of follow-up. Clinical and exercise test variables were collected prospectively according to standard definitions; testing and data management were performed in a standardized fashion using a computer-assisted protocol. All-cause mortality was utilized as the end point for follow-up. Standard survival analysis was performed, including Kaplan-Meier curves and a Cox hazard model. RESULTS There were 6,213 male patients (mean +/- SD age, 59 +/- 11 years) who underwent standard exercise ECG treadmill testing over the study period with a mean follow-up duration of 6.2 +/- 3.7 years. There were no complications of testing in this clinically referred population, 78% of whom were referred for chest pain, or risk factors or signs or symptoms of ischemic heart disease. Overlapping thirds had typical angina or history of myocardial infarction (MI). Five hundred seventy-nine patients had prior coronary artery bypass surgery, and 522 patients had a history of congestive heart failure (CHF). Indications for testing were in accordance with published guidelines. Twenty percent died over the follow-up period, for an average annual mortality rate of 2.6%. Cox hazard function chose the following variables in rank order as independently and significantly associated with time to death: exercise capacity (metabolic equivalents < 5, age > 65 years, history of CHF, and history of MI. A score based on these variables (summing up the four variables [if yes = 1 point]) classified patients into low-risk, medium-risk, and high-risk groups. The high-risk group (score > or = 3) has a hazard ratio of 5.0 (95% confidence interval, 4.7 to 5.3) and a 5-year mortality rate of 31%. CONCLUSION This comprehensive analysis provides rates of various abnormal responses that can be expected in patients referred for exercise testing at a typical medical center. Four simple variables combined as a score powerfully stratified patients according to prognosis.
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Prakash M, Myers J, Froelicher VF, Marcus R, Do D, Kalisetti D, Froning J, Atwood JE. Diagnostic exercise tests on 4000 consecutive men. Am Heart J 2001; 142:127-35. [PMID: 11431668 DOI: 10.1067/mhj.2001.115795] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Our purpose was to report the prevalence of abnormal treadmill test responses and their association with mortality in a large consecutive series of patients referred for standard diagnostic exercise tests, with testing performed and reported in a standardized fashion. BACKGROUND Exercise testing is widely performed, but an analysis of responses has not been presented for a large number of consecutive tests performed on patients referred for diagnosis of cardiac disease. METHODS All patients referred for evaluation at 2 university-affiliated Veterans Affairs Medical Centers who underwent exercise treadmill tests for clinical indications between 1987 and 2000 were determined to be dead or alive according to the Social Security Death Index after a mean 5.9-year follow-up. Patients with established heart disease (ie, prior coronary bypass surgery, myocardial infarction, or congestive heart failure) were excluded from analyses. Clinical and exercise test variables were collected prospectively according to standard definitions; testing and data management were performed in a standardized fashion with a computer-assisted protocol. All-cause mortality was used as the end point for follow-up. Standard survival analysis was performed, including Kaplan-Meier curves and a Cox hazard model. RESULTS After the exclusions, 3974 men (mean age 57.5 +/- 11 years) had standard diagnostic exercise testing over the study period with a mean of 5.9 (+/-3.7) years of follow-up (64% of all tested). There were no complications of testing in this clinically referred population, 82% of whom were referred for chest pain, risk factors, or signs and symptoms of ischemic heart disease. Five hundred forty-nine (14%) had a history of typical angina. Indications for testing were in accordance with published guidelines. A total of 545 died, yielding an annual mortality rate of 1.8%. The Cox hazard model chose the following variables in rank order as independently associated with time to death: change in rate pressure product, age greater than 65 years, METs less than 5, and electrocardiographic left ventricular hypertrophy. A score based on these variables classified patients into low-, medium-, and high-risk groups. The high-risk group with a score greater than 3 has a hazard ratio of 4 (95% confidence interval 3.82-4.27) and an annual mortality rate of 4%. CONCLUSION This comprehensive analysis provides rates of various abnormal responses that can be expected in men referred for diagnostic exercise testing at typical Veterans Administration Medical Centers. Four simple variables combined as a score predict all-cause mortality after clinical decisions for therapy are prescribed.
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Pons JA, Steiner AW, Prakash M, Lattimer JM. Evolution of proto-neutron stars with quarks. PHYSICAL REVIEW LETTERS 2001; 86:5223-5226. [PMID: 11384463 DOI: 10.1103/physrevlett.86.5223] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2001] [Indexed: 05/23/2023]
Abstract
Neutrino fluxes from proto-neutron stars with and without quarks are studied. Observable differences become apparent after 10-20 s of evolution. Sufficiently massive stars containing negatively charged, strongly interacting, particles collapse to black holes during the first minute of evolution. Since the neutrino flux vanishes when a black hole forms, this is the most obvious signal that quarks (or other types of strange matter) have appeared. The metastability time scales for stars with quarks are intermediate between those containing hyperons and kaon condensates.
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Prakash M, Turan ÖF, Li Y, Mahoney J, Thorpe GR. Impinging round jet studies in a cylindrical enclosure with and without a porous layer: Part I—Flow visualisations and simulations. Chem Eng Sci 2001. [DOI: 10.1016/s0009-2509(01)00102-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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197
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Prakash M, Turan ÖF, Li Y, Mahoney J, Thorpe GR. Impinging round jet studies in a cylindrical enclosure with and without a porous layer: Part II—LDV measurements and simulations. Chem Eng Sci 2001. [DOI: 10.1016/s0009-2509(01)00103-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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198
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Prakash M, Poreddy V, Tiyyagura L, Bonacini M. Jaundice and hepatocellular damage associated with nevirapine therapy. Am J Gastroenterol 2001; 96:1571-1574. [PMID: 11374701 DOI: 10.1016/s0002-9270(01)02342-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
OBJECTIVE Nevirapine is a nonnucleoside reverse transcription inhibitor that is used as part of highly active antiretroviral therapeutic combinations. Nevirapine has been associated with a skin rash in 32 to 48% of patients. Recent reports indicate that hepatic toxicity also occurs. METHODS We describe four instances of reversible hepatocellular damage associated with the use of nevirapine in patients with HIV infection. Two of the four patients were also coinfected with the hepatitis C virus. RESULTS Evidence of malaise, skin rash, and icteric hepatitis with pruritus occurred 4-6 wk after the beginning of nevirapine therapy. No evidence of metabolic acidosis was present in any of our patients. In all cases, liver test results declined to normal or near normal levels, and pruritus disappeared 4-6 wk after discontinuation of the medication. No patient was rechallenged with the drug. CONCLUSION Nevirapine can be associated with icteric hepatitis, which appears to be reversible after withdrawal of the drug.
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Prakash M, Poreddy V, Tiyyagura L, Bonacini M. Jaundice and hepatocellular damage associated with nevirapine therapy. Am J Gastroenterol 2001; 96:1571-4. [PMID: 11374701 DOI: 10.1111/j.1572-0241.2001.03779.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Nevirapine is a nonnucleoside reverse transcription inhibitor that is used as part of highly active antiretroviral therapeutic combinations. Nevirapine has been associated with a skin rash in 32 to 48% of patients. Recent reports indicate that hepatic toxicity also occurs. METHODS We describe four instances of reversible hepatocellular damage associated with the use of nevirapine in patients with HIV infection. Two of the four patients were also coinfected with the hepatitis C virus. RESULTS Evidence of malaise, skin rash, and icteric hepatitis with pruritus occurred 4-6 wk after the beginning of nevirapine therapy. No evidence of metabolic acidosis was present in any of our patients. In all cases, liver test results declined to normal or near normal levels, and pruritus disappeared 4-6 wk after discontinuation of the medication. No patient was rechallenged with the drug. CONCLUSION Nevirapine can be associated with icteric hepatitis, which appears to be reversible after withdrawal of the drug.
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Page D, Prakash M, Lattimer JM, Steiner AW. Prospects of detecting baryon and quark superfluidity from cooling neutron stars. PHYSICAL REVIEW LETTERS 2000; 85:2048-2051. [PMID: 10970460 DOI: 10.1103/physrevlett.85.2048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2000] [Indexed: 05/23/2023]
Abstract
Baryon and quark superfluidity in the cooling of neutron stars are investigated. Future observations will allow us to constrain combinations of the neutron or Lambda-hyperon pairing gaps and the star's mass. However, in a hybrid star with a mixed phase of hadrons and quarks, quark gaps larger than a few tenths of an MeV render quark matter virtually invisible for cooling. If the quark gap is smaller, quark superfluidity could be important, but its effects will be nearly impossible to distinguish from those of other baryonic constituents.
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