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Nagaraja D, Gururaj G, Girish N, Panda S, Roy AK, Sarma GRK, Srinivasa R. Feasibility study of stroke surveillance: data from Bangalore, India. Indian J Med Res 2009; 130:396-403. [PMID: 19942742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND & OBJECTIVE Stroke is a leading cause of deaths, and disabilities in India. Reliable and good quality data on epidemiological characteristics of stroke are essential to plan, implement and evaluate stroke prevention and control programmes. A feasibility study was undertaken in Bangalore to examine the possibility of establishing stroke surveillance and to develop methodology for a larger programme. METHODS The study adapted WHO STEPs-STROKE methodology to collect data on hospitalized stroke events and fatal stroke events in the city of Bangalore. In STEP I, Information was collected from 1,174 stroke patients in three large hospitals and were followed till discharge and 28 days; outcome was measured as death or disability. Stroke cases fulfilling diagnostic criteria, evaluated by neurologists and CT/MRI confirmed cases were included. Brief information on major risk factors was collected from all stroke patients / family members and from medical records by trained research officers. In STEP II, death records of Bangalore Mahanagara Palike for 2004 (n=23,312) were analyzed to identify stroke related deaths. RESULTS Using WHO-STEPs approach, a methodology was developed for stroke surveillance in a geographically defined population. By STEP 1 method--7 per cent of medical and 45 per cent of neurological admissions were due to stroke with a fatality rate of 9 per cent at hospital discharge and 20 per cent at 28 days. With a mean age of 54.5 (+/- 17.0) yr and male preponderance, nearly half had one or more risk factors. Weakness or paresis (92%) was the commonest presentation and ischaemic stroke was most frequent (73.8%). One third of total stroke patients were dependent at both discharge and 28 day follow up. By STEP II method the proportional mortality rate for Bangalore city was observed to be 6 per cent and more than 50 per cent of total stroke deaths had occurred in 10 major hospitals. INTERPRETATION & CONCLUSION The present study has shown that stroke surveillance is possible and feasible. Institution based (hospitals and vital registry data) stroke surveillance supplemented with periodical population based information can provide comprehensive information on vital aspects of stroke like mortality, risk factors, disability and outcome. There is a need to develop stroke surveillance in a phased manner along with mechanisms to apply data for prevention and control programmes.
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Zuo XN, Shehzad ZE, Di Martino A, Kelly AMC, Reiss PT, Gee DG, Gotimer K, Uddin LQ, Lee SH, Margulies DS, Roy AK, Petkova E, Biswal BB, Klein DF, Castellanos FX, Milham MP. Establishing the Reliability of Amplitude Measures for Spontaneous Fluctuations in the Resting Brain. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70602-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Mathew T, Sarma G, Kamath V, Roy AK. Subdural hematoma, subarachnoid hemorrhage and intracerebral parenchymal hemorrhage secondary to cerebral sinovenous thrombosis: A rare combination. Neurol India 2007; 55:438-9. [DOI: 10.4103/0028-3886.37110] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Roy AK, Khanduri S, Girisha KM. Fusiform swellings of fingers in a 3-year-old girl. J Postgrad Med 2006; 52:314, 324. [PMID: 17102559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
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Gupta G, Jain RK, Maikhuri JP, Shukla PK, Kumar M, Roy AK, Patra A, Singh V, Batra S. Discovery of substituted isoxazolecarbaldehydes as potent spermicides, acrosin inhibitors and mild anti-fungal agents. Hum Reprod 2005; 20:2301-8. [PMID: 15932909 DOI: 10.1093/humrep/dei041] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The continued endeavour to design novel, non-detergent molecules that can be useful as topical, prophylactic contraceptives has led to the discovery of substituted isoxazolecarbaldehydes as a new class of compounds exhibiting both spermicidal and acrosin inhibitory activities simultaneously. METHODS Normal human semen samples were used to detect the spermicidal and acrosin inhibitory activities of the new compounds. Lactobacillus, HeLa and Candida cultures were used to determine the safety of compounds towards normal vaginal flora, their cytotoxicity and anti-fungal activity. Supravital staining and the hypo-osmotic swelling test (HOST) were used to detect the effect on sperm membrane integrity. Nonoxynol-9 (N-9) was used as a reference standard. RESULTS The 5- and 3-substituted isoxazolecarbaldehydes showed significant spermicidal [minimum effective concentration (MEC)=0.005-2.5%] and acrosin inhibitory (IC50=3.9-58 x 10(-4) mol/l) activities in several molecules along with weak fungicidal activity against Candida albicans. Lineweaver-Burk and Dixon plot analysis of a representative structure showed non-competitive inhibition of human acrosin enzyme, and the most potent acrosin inhibitors also considerably diminished the induction of the acrosome reaction by Ca2+ ionophore. Some compounds were found to be significantly safer than N-9 towards Lactobacillus acidophilus in vitro at their respective spermicidal MECs. In the cytotoxicity assay, the IC50 of these compounds towards the HeLa cell line was of the same order as N-9 (0.9-0.1 mmol/l); however, in contrast, the compounds exhibited only a moderate effect on sperm membrane integrity. CONCLUSIONS This study indicates that 5- and 3-substituted isoxazolecarbaldehydes are 'first generation' multifunctional, spermicidal molecules that hold promise for development as topical contraceptives with useful associated activities that can add considerably to their effectiveness, safety and prophylaxis.
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Batra S, Roy AK, Patra A, Bhaduri AP, Surin WR, Raghavan SAV, Sharma P, Kapoor K, Dikshit M. Baylis–Hillman reaction assisted parallel synthesis of 3,5-disubstituted isoxazoles and their in vivo bioevaluation as antithrombotic agents. Bioorg Med Chem 2004; 12:2059-77. [PMID: 15080910 DOI: 10.1016/j.bmc.2004.02.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Revised: 02/23/2004] [Accepted: 02/24/2004] [Indexed: 10/26/2022]
Abstract
The solution-phase parallel synthesis involving reactions of Baylis-Hillman products of 3-substituted-5-isoxazolecarbaldehydes with nucleophiles and their in vivo antithrombotic evaluations are described along with the results of in vitro platelet aggregation inhibition assay of a few compounds. Results of the detailed evaluation of one of the compounds as an inhibitor of platelet aggregation are also presented.
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Roy AK, Malaviya DR, Kaushal P, Kumar B, Tiwari A. Interspecific hybridization of Trifolium alexandrinum with T. constantinopolitanum using embryo rescue. PLANT CELL REPORTS 2004; 22:705-710. [PMID: 14745504 DOI: 10.1007/s00299-004-0759-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2003] [Revised: 01/06/2004] [Accepted: 01/06/2004] [Indexed: 05/24/2023]
Abstract
The embryo rescue technique was successfully used to raise hybrids between Trifolium alexandrinum and T. constantinopolitanum. As a result of its narrow genetic base, genetic improvement in Egyptian clover (syn. Berseem; T. alexandrinum), an important fodder crop in tropical and subtropical countries, is hampered, thereby making it imperative to introduce alien genes from related species. In a conventional interspecific hybridization program, hybrids could not be raised due to post-fertilization barriers. Of the several combinations tried, pollination 2 days after emasculation was found to be the best. Globular embryos were observed 5-7 days after pollination (DAP), followed by heart-shaped embryos 10-12 DAP. Embryos excised at the heart-shaped stage responded well to EC3 culture medium. Of 612 crosses, 33 healthy embryos could be excised and cultured on EC3 medium. The plumule emerged 8-12 days following inoculation. The embryo-rescued plants were hardened, inoculated with Rhizobium and transferred to the field. The hybrids showed intermediate morphological features with reduced pollen fertility (55-65%) and a chromosomal complement of 2n = 16. Biochemical characterization using isozymes confirmed hybridity.
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Roy AK, Rajesh SV, Iby N, Jose JM, Sarma GR. A study of epilepsy-related psychosis. Neurol India 2003; 51:359-60. [PMID: 14652438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
The association of epilepsy and psychosis is studied. Among the 500 patients of epilepsy evaluated, there were 12 patients, 8 males and 4 females with epilepsy-related psychosis. Their average age was 38 years. The interval between the age of onset of epilepsy and psychotic features was 9 years. Complex partial seizures were present in 7 patients and primary generalized tonic-clonic seizure was present in 1 patient. Four patients had post-ictal psychosis, 7 had acute interictal psychosis and 1 patient had chronic psychosis. The inter-ictal and chronic psychoses were schizophreniform whereas the post-ictal psychoses were not. EEG showed a temporal focus in 7 patients with complex partial seizures and an extra-temporal focus was identified in 4 out of the other 5 patients. Imaging (CT scan/MRI) revealed abnormalities in 10 patients. This study attempts to define the characteristics of psychoses occurring in epileptics.
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Sarma GRK, Kumar A, Roy AK, Pinheiro L. Post-cardiorespiratory arrest beta-alpha coma: an unusual electroencephalographic phenomenon. Neurol India 2003; 51:266-8. [PMID: 14571023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
The presence of frontally-dominant alpha pattern in the EEG is common in patients with coma due to trauma, toxic-metabolic causes and following cardiorespiratory arrest. Diffuse beta activity following resuscitation after a cardiac arrest is not well recognized. We report a case of coma in a 3-year-old girl who had a cardiac arrest from which she was revived. Initial EEG showed diffuse beta activity, which later evolved to predominantly alpha activity. The possible mechanisms involved in the generation of such rhythms are discussed. Transition of EEG activity from faster to slower frequencies is suggested as an adverse prognostic factor in post-cardiorespiratory arrest coma.
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Pinheiro L, Roy AK, Sarma GRK, Kumar A. Relevance of computerized electroencephalographic topography (brain mapping) in ischemic stroke. Neurol India 2003; 51:235-6. [PMID: 14571011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
BACKGROUND AND AIMS Computerized electroencephalographic topography (CET) (brain mapping) is a non-invasive, spatially oriented procedure for depicting amplitude and frequency patterns by two-dimensional color-coded frequency and amplitude display of the electroencephalograph (EEG). MATERIAL AND METHODS We prospectively studied the relationship between CT scan lesions, conventional EEG and brain mapping in 40 patients with ischemic stroke within 1 week of onset. EEG and brain mapping was done within 24 hours of doing CT scan. RESULTS There were 32 males and 8 females and the mean age was 56 years (range 27-75 years). CET/EEG was normal in 2 patients with capsular infarct. Brain mapping showed abnormalities (most commonly low-frequency high-amplitude changes) in 95% of patients, whereas EEG abnormalities were seen in only 40%. Brain mapping abnormalities were appropriate to the side of the CT scan lesion in 20 (52.63%) patients and were present bilaterally n 18 (47.37%) patients. Brain mapping abnormalities were ipsilateral to the side of the CT lesion when the lesion was < 2 cm in diameter and they were bi-hemispherical when the CT lesion was > 2 cm in diameter. CONCLUSIONS There was no correlation between motor deficits and brain map abnormalities.
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Sarma GRK, Roy AK. Nadroparin plus aspirin versus aspirin alone in the treatment of acute ischemic stroke. Neurol India 2003; 51:208-10. [PMID: 14571005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Low-molecular-weight-heparin (LMWH) has been widely used in the treatment of acute ischemic stroke but controlled trials are few. In this study, 40 patients with acute ischemic stroke of less than 24 hours duration were randomized to receive either aspirin (325 mg/day) alone or aspirin (325 mg/day) plus subcutaneous nadroparin 4100 units/day. At the end of 4 weeks, the morbidity and mortality were significantly less in the nadroparin group as compared to the aspirin group. There was no increased risk of clinically significant intracranial hemorrhage in either group. The combination of aspirin and LMWH deserves to be tested in larger studies.
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Roy AK, Pinheiro L, Rajesh SV. Prevalence of photosensitivity--an Indian experience. Neurol India 2003; 51:241-3. [PMID: 14571013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
One thousand nine hundred and forty newly recruited entrants for training as pilots (Group A) underwent photic stimulation during EEG recording during the entrance examination to the flying stream. One hundred and sixty individuals (Group B) working on radars for prolonged periods were interviewed for eliciting complaints referable to photosensitivity and were subjected to EEG. EEGs in respect to 1000 cases (Group C) of known epilepsy were examined for the incidence of a photosensitive response. The study has revealed that 14 cases (0.72%) in group A had an abnormal response to photic stimulation out of which one case developed seizure during EEG recording. One case (0.62%) in group B and 30 cases (3%) in group C were detected to have photosensitivity. The maximum response was seen at 20 Hz stimulation. The prevalence of photosensitivity and its manifestations in these groups indicates that this condition is not uncommon.
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Sarma GRK, Kumar A, Roy AK. Unusual radiological picture in eclamptic encephalopathy. Neurol India 2003; 51:127-8. [PMID: 12865550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
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Mahata J, Basu A, Ghoshal S, Sarkar JN, Roy AK, Poddar G, Nandy AK, Banerjee A, Ray K, Natarajan AT, Nilsson R, Giri AK. Chromosomal aberrations and sister chromatid exchanges in individuals exposed to arsenic through drinking water in West Bengal, India. Mutat Res 2003; 534:133-43. [PMID: 12504762 DOI: 10.1016/s1383-5718(02)00255-3] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Arsenic contamination in groundwater has become a worldwide problem. Currently an unprecedented number of people in West Bengal, India and Bangladesh are exposed to the ubiquitous toxicant via drinking water in exposure levels far exceeding the maximum recommended limit laid down by WHO. This arsenic epidemic has devastated nine districts of West Bengal encompassing an area of 38,865 km(2) leading to various clinical manifestations of chronic arsenicosis. We conducted a human bio-monitoring study using chromosomal aberrations (CA) and sister chromatid exchanges (SCE) as end points to explore the cytogenetic effects of chronic arsenic toxicity in the population of North 24 Parganas, one of the arsenic affected districts in West Bengal. Study participants included 59 individuals residing in this district where the mean level (+/-S.E.) of arsenic in drinking water (microg/l) was 211.70+/-15.28. As age matched controls with similar socio-economic status we selected 36 healthy, asymptomatic individuals residing in two unaffected districts--Midnapur and Howrah where the mean arsenic content of water (microg/l) was 6.35+/-0.45. Exposure was assessed by standardized questionnaires and by detecting the levels of arsenic in drinking water, nails, hair and urine samples. In the exposed group the mean arsenic concentrations in nails (microg/g), hair (microg/g) and urine (microg/l) samples were 9.04+/-0.78, 5.63+/-0.38 and 140.52+/-8.82, respectively, which were significantly high (P<0.01) compared to the corresponding control values of 0.44+/-0.03, 0.30+/-0.02 and 5.91+/-0.49, respectively. Elevated mean values (P<0.01) of the percentage of aberrant cells (8.08%) and SCEs per cell (7.26) were also observed in the exposed individuals in comparison to controls (1.96% and 5.95, respectively). The enhanced rates of CAs and SCEs among the residents of North 24 Parganas are indicative of the cytogenetic damage due to long term exposure to arsenic through consumption of contaminated water.
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Basu A, Mahata J, Roy AK, Sarkar JN, Poddar G, Nandy AK, Sarkar PK, Dutta PK, Banerjee A, Das M, Ray K, Roychaudhury S, Natarajan AT, Nilsson R, Giri AK. Enhanced frequency of micronuclei in individuals exposed to arsenic through drinking water in West Bengal, India. Mutat Res 2002; 516:29-40. [PMID: 11943608 DOI: 10.1016/s1383-5718(02)00014-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In West Bengal, India arsenic in ground water has been found to be above the maximum permissible limit in seven districts covering an area of 37,493km2. In the present study, evaluation of the micronuclei (MN) formation in oral mucosa cells, urothelial cells and peripheral blood lymphocytes was carried out in the symptomatic individuals exposed to arsenic through drinking water. Forty five individuals with cutaneous signs of arsenicism from four affected districts (368.11 microg/l of As in drinking water) were considered as the exposed group and 21 healthy individuals with no symptoms of arsenic poisoning and residing in two unaffected districts (5.49 microg/l of As) were considered as controls. The exposed and control groups had similar age distribution and socioeconomic status. Standardised questionnaires were utilised and medical examination was conducted to ascertain exposure history, sociodemographic characteristics, diet, health, medication, addiction and chief symptoms in the study participants. Arsenic exposure was confirmed by measuring the arsenic content in the drinking water, nails, hair and urine samples from the volunteers. Arsenic contents in the urine, nail and hair in the exposed group were 24.45 microg/l, 12.58 and 6.97 microg/g, respectively which were significantly high in comparison to corresponding control group values of 4.88 microg/l, 0.51 and 0.34 microg/g, respectively. Exposed individuals showed a statistically significant increase in the frequency of MN in oral mucosa, urothelial cells and lymphocytes (5.15, 5.74 and 6.39/1000 cells, respectively) when compared with the controls (0.77, 0.56 and 0.53/1000 cells, respectively). Thus, the above results indicate that the symptomatic individuals exposed to arsenic through drinking water in this region have significant cytogenetic damage.
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Roy AK, Tyagi RK, Song CS, Lavrovsky Y, Ahn SC, Oh TS, Chatterjee B. Androgen receptor: structural domains and functional dynamics after ligand-receptor interaction. Ann N Y Acad Sci 2001; 949:44-57. [PMID: 11795379 DOI: 10.1111/j.1749-6632.2001.tb04001.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Androgens are C-19 steroids secreted primarily from the testes and adrenals that play a critical role in reproduction. Reproductive functions of androgens are mediated through coordination of diverse physiological processes ranging from brain functions to specific cell proliferation and apoptosis. At the molecular level, most of these regulatory influences are exerted by altered expression of appropriate genes by the androgen receptor (AR), a member of the nuclear receptor (NR) superfamily. The unliganded AR is a cytoplasmic protein and, upon ligand binding, it translocates into the nucleus. Thereafter, in conjunction with other transcription factors and coactivators, the AR influences transcription of target genes through a multistep process that includes its clustering in a subnuclear compartment. Here, we describe the genomic organization of the AR, the role of individual structural domains in specific AR function, and the influence of agonistic/antagonistic ligands in the intracellular movement of the receptor. We also show that the AR is capable of undergoing multiple rounds of nucleocytoplasmic recycling after ligand binding and dissociation. Xenobiotic ligands, considered as selective androgen receptor modulators (SARMs), can modulate AR activity by inhibiting either its nuclear translocation or its subnuclear clustering and subsequent transactivation function.
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Song CS, Echchgadda I, Baek BS, Ahn SC, Oh T, Roy AK, Chatterjee B. Dehydroepiandrosterone sulfotransferase gene induction by bile acid activated farnesoid X receptor. J Biol Chem 2001; 276:42549-56. [PMID: 11533040 DOI: 10.1074/jbc.m107557200] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dehydroepiandrosterone sulfotransferase (STD) is a hydroxysteroid sulfo-conjugating enzyme with preferential substrate specificity for C-19 androgenic steroids and C-24 bile acids. STD is primarily expressed in the liver, intestine and adrenal cortex. Earlier studies have shown that androgens inhibit the rat Std promoter function through a negative androgen response region located between -235 and -310 base pair positions (Song, C. S., Jung, M. H., Kim, S. C., Hassan, T., Roy, A. K., and Chatterjee, B. (1998) J. Biol. Chem. 273, 21856-21866). Here we report that the primary bile acid chenodeoxycholic acid (CDCA) also acts as an important regulator of the Std gene promoter. CDCA is a potent inducer of the Std gene, and its inducing effect is mediated through the bile acid-activated farnesoid X receptor (FXR), a recently characterized member of the nuclear receptor superfamily. The ligand-activated FXR acts as a heterodimer with the 9-cis-retinoic acid receptor (RXR) and regulates the Std gene by binding to an upstream region at base pair positions -169 to -193. This specific binding region was initially identified by bile acid responsiveness of the progressively deleted forms of the Std promoter in transfected HepG2 hepatoma and enterocyte-like Caco-2 cells. Subsequently, the precise RXR/FXR binding position was established by protein-DNA interaction using in vitro footprinting and electrophoretic mobility shift analyses. Unlike all other previously characterized FXR target genes, which contain an inverted repeat (IR) of the consensus hexanucleotide half-site (A/G)G(G/T)TCA with a single nucleotide spacer (IR-1), the bile acid response element of the Std promoter does not contain any spacer between the two hexanucleotide repeats (IR-0). A promoter-reporter construct carrying three tandem copies of the IR-0 containing -169/-193 element, linked to a minimal thymidine kinase promoter, can be stimulated more than 70-fold in transfected Caco-2 cells upon CDCA treatment. Autoregulation of the STD gene by its bile acid substrate may provide an important contributing role in the enterohepatic bile acid metabolism and cholesterol homeostasis.
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Rotter N, Bonassar LJ, Tobias G, Lebl M, Roy AK, Vacanti CA. Age dependence of cellular properties of human septal cartilage: implications for tissue engineering. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 2001; 127:1248-52. [PMID: 11587607 DOI: 10.1001/archotol.127.10.1248] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND The persistent need for cartilage replacement material in head and neck surgery has led to novel cell culture methods developed to engineer cartilage. Currently, there is no consensus on an optimal source of cells for these endeavors. OBJECTIVES To evaluate human nasal cartilage as a potential source of chondrocytes and to determine the effect of donor age on cellular and proliferation characteristics. SUBJECTS Nasal cartilage specimens were obtained after reconstructive surgery from 46 patients ranging in age from 15 to 60 years. METHODS Specimens were weighed and chondrocytes were isolated by digestion in 0.2% collagenase type II for 16 hours. Cells were maintained in primary cultures until confluency, then seeded onto polylactic acid-polyglycolic acid scaffolds. Seeding efficiency was determined by quantification of DNA content of seeded constructs by means of Hoechst dye 33258. Specimen weights, cell yields, cell content, and doubling time were also measured and correlated to donor age. RESULTS Mean (+/-SD) cartilage mass obtained (648 +/- 229 mg) is higher than from typical biopsy specimens of auricular cartilage, and the cellular characteristics show a higher proliferation rate than auricular chondrocytes. Cell yield increased with age, while doubling time decreased with age in samples from patients ranging from 15 to 60 years old. CONCLUSIONS The use of nasal septal cartilage as a source of cells for tissue engineering may be valid over a wide range of patient ages. The large tissue yield and consequent cell yield make this tissue a potential starting source of chondrocytes for large-volume tissue-engineered implants.
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Chang SC, Rowley JA, Tobias G, Genes NG, Roy AK, Mooney DJ, Vacanti CA, Bonassar LJ. Injection molding of chondrocyte/alginate constructs in the shape of facial implants. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2001; 55:503-11. [PMID: 11288078 DOI: 10.1002/1097-4636(20010615)55:4<503::aid-jbm1043>3.0.co;2-s] [Citation(s) in RCA: 231] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Over one million patients per year undergo some type of procedure involving cartilage reconstruction. Polymer hydrogels, such as alginate, have been shown to be effective carriers for chondrocytes in subcutaneous cartilage formation. The goal of our current study was to develop a method to create complex structures (nose bridge, chin, etc.) with good dimensional tolerance to form cartilage in specific shapes. Molds of facial implants were prepared using Silastic ERTV. Suspensions of chondrocytes in 2% alginate were gelled by mixing with CaSO(4) (0.2 g/mL) and injected into the molds. Constructs of various cell concentrations (10, 25, and 50 million/mL) were implanted in the dorsal aspect of nude mice and harvested at times up to 30 weeks. Analysis of implanted constructs indicated progressive cartilage formation with time. Proteoglycan and collagen constructs increased with time to approximately 60% that of native tissue. Equilibrium modulus likewise increased with time to 15% that of normal tissue, whereas hydraulic permeability decreased to 20 times that of native tissue. Implants seeded with greater concentrations of cells increased proteoglycan content and collagen content and equilibrium and decreased permeability. Production of shaped cartilage implants by this technique presents several advantages, including good dimensional tolerance, high sample-to-sample reproducibility, and high cell viability. This system may be useful in the large-scale production of precisely shaped cartilage implants.
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Tripathi M, Sanjeev CC, Roy AK. Chasing hyponatraemia: unusual presentation. Neurol India 2001; 49:197-9. [PMID: 11447447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Two females, in their sixth decade, presented with recurrent episodes of headache, vertigo, vomiting and altered sensorium. Both patients had persistent hyponatraemia as the only clue. Detailed investigations revealed a pituitary aetiology in both. One patient had a pituitary microadenoma while the other had an empty sella syndrome. The diagnosis and management is discussed and the relevant literature reviewed.
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Cresswell A, Sackville Hamilton NR, Roy AK, Viegas BM. Use of amplified fragment length polymorphism markers to assess genetic diversity of Lolium species from Portugal. Mol Ecol 2001; 10:229-41. [PMID: 11251801 DOI: 10.1046/j.1365-294x.2001.01170.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We evaluated the use of amplified fragment length polymorphism (AFLP) markers to distinguish genotypes, populations and species of Lolium. Accessions of two species Lolium perenne and Lolium multiflorum and their hybrid Lolium x hybridum, collected by the Institute of Grass and Environmental Research in 1995 from locations across Portugal, were used. The genetic variation within and between populations from the extremes of latitude and altitude was determined and assessed. Three primer pair combinations generated 765 polymorphic bands. Principal coordinate analysis of similarities between 127 plants showed high dimensionality in the data. Axes 1-3 were associated primarily with species differences, axes 4-14 with population differences within species and axis 15 onwards with within population differences. UPGMA analysis confirmed the groupings. The three populations of L. perenne formed a discrete cluster widely separated from all other populations. There were two distinct groups of L. x hybridum, of which one was similar to and overlapped with L. multiflorum and the second formed a distinct cluster. Analyses of individual bands showed that every inter- and intraspecific contrast involved a different sets of bands, again confirming the high dimensionality of the data. No single band was strictly diagnostic of any population or species. Nevertheless, the UPGMA analysis showed little or no overlap between populations. Thus, despite the high ratio of within-to-between population genetic variance, the full AFLP banding pattern of each genotype is a relatively reliable fingerprint diagnostic of its parent population. The high dimensionality implies that many different factors contribute to the differences observed. This adds to the potential value of the methodology, since it implies that there is a reasonably high likelihood of finding bands relevant to a given environmental gradient or other factor influencing the distribution of genetic diversity.
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Chakrabarti BK, Roy AK, Manna SS. Breakdown exponents in lattice and continuum percolation. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3719/21/3/005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Mahadevan A, Santosh V, Gayatri N, Ratnavalli E, NandaGopal R, Vasanth A, Roy AK, Shankar SK. Infantile neuroaxonal dystrophy and giant axonal neuropathy--overlap diseases of neuronal cytoskeletal elements in childhood? Clin Neuropathol 2000; 19:221-9. [PMID: 11048747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Giant axonal neuropathy (GAN) and infantile neuroaxonal dystrophy (INAD) are two progressive neurodegenerative disorders of childhood that have considerable clinical as well as histological overlap but are believed to be ultrastructurally distinct. The clinicopathological and ultrastructural features of three cases of INAD, two of whom are siblings and one case of GAN are described. The sural nerve biopsies in all four cases were essentially similar on light microscopy revealing giant axons. On electron microscopy, the findings in the case of GAN were typical with dense accumulation of neurofilaments within the giant axons. In the three cases of INAD, too, in addition to accumulation of mitochondria and organelles with vesiculotubular profiles, a similar increase in neurofilaments was evident. We, therefore, believe that these two disorders may represent a spectrum in evolution of intermediate filament pathology with various organelles participating in the temporal evolution of the disease process.
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Tyagi RK, Lavrovsky Y, Ahn SC, Song CS, Chatterjee B, Roy AK. Dynamics of intracellular movement and nucleocytoplasmic recycling of the ligand-activated androgen receptor in living cells. Mol Endocrinol 2000; 14:1162-74. [PMID: 10935541 DOI: 10.1210/mend.14.8.0497] [Citation(s) in RCA: 190] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
An expression construct containing the cDNA encoding a modified aequorea green fluorescent protein (GFP) ligated to the 5'-end of the rat androgen receptor (AR) cDNA (GFP-AR) was used to study the intracellular dynamics of the receptor movement in living cells. In three different cell lines, ie. PC3, HeLa, and COS1, unliganded GFP-AR was seen mostly in the cytoplasm and rapidly (within 15-60 min) moved to the nuclear compartment after androgen treatment. Upon androgen withdrawal, the labeled AR migrated back to the cytoplasmic compartment and maintained its ability to reenter the nucleus on subsequent exposure to androgen. Under the condition of inhibited protein synthesis by cycloheximide (50 microg/ml), at least four rounds of receptor recycling after androgen treatment and withdrawal were recorded. Two nonandrogenic hormones, 17beta-estradiol and progesterone at higher concentrations (10(-7)/10(-6) M), were able to both transactivate the AR-responsive promoter and translocate the GFP-AR into the nucleus. Similarly, antiandrogenic ligands, cyproterone acetate and casodex, were also capable of translocating the cytoplasmic AR into the nucleus albeit at a slower rate than the androgen 5alpha-dihydrotestosterone (DHT). All AR ligands with transactivation potential, including the mixed agonist/antagonist cyproterone acetate, caused translocation of the GFP-AR into a subnuclear compartment indicated by its punctate intranuclear distribution. However, translocation caused by casodex, a pure antagonist, resulted in a homogeneous nuclear distribution. Subsequent exposure of the casodex-treated cell to DHT rapidly (15-30 min) altered the homogeneous to punctate distribution of the already translocated nuclear AR. When transported into the nucleus either by casodex or by DHT, GFP-AR was resistant to 2 M NaCl extraction, indicating that the homogeneously distributed AR is also associated with the nuclear matrix. Taken together, these results demonstrate that AR requires ligand activation for its nuclear translocation where occupancy by only agonists and partial agonists can direct it to a potentially functional subnuclear location and that one receptor molecule can undertake multiple rounds of hormonal signaling; this indicates that ligand dissociation/inactivation rather than receptor degradation may play a critical role in terminating hormone action.
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Lavrovsky Y, Chatterjee B, Clark RA, Roy AK. Role of redox-regulated transcription factors in inflammation, aging and age-related diseases. Exp Gerontol 2000; 35:521-32. [PMID: 10978675 DOI: 10.1016/s0531-5565(00)00118-2] [Citation(s) in RCA: 226] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A progressive rise of oxidative stress due to the altered redox homeostasis appears to be one of the hallmarks of the aging process. Reactive oxygen species (ROS) also serve as signaling agents for inflammation, a systemic defensive reaction against microbial pathogens and other foreign bodies. Changes in the pattern of gene expression through ROS-sensitive transcription factors give rise to both aging and inflammation phenotypes. Chronic oxidative stress and inflammatory reaction also lead to many age-associated diseases such as atherosclerosis and arthritis. Transcription factors that are directly influenced by ROS and proinflammatory cytokines include nuclear factor kappa B (NF-kappaB), activator protein 1 (AP-1), specificity protein 1 (Sp1), peroxisome proliferator-activated receptors (PPARs) and other members of the nuclear receptor superfamily. Here we describe the basic components of the intracellular redox control machinery and their dysregulation with age leading to altered transcription factor function and age-associated pathophysiology.
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