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Biomedical subjects

S Satish

Publications and source records attributed to S Satish.

18 recordsLinked to original sources
PubMed2005

Altered structure and expression of RB1 gene and increased phosphorylation of pRb in human vestibular schwannomas.

Tumor-specific alterations at the RB1 gene locus in 30 human vestibular schwannomas including 10 NF2 and 20 sporadic cases were analysed. Southern blot analysis of DNA from these samples revealed loss of heterozygosity (LOH) at the RB1 locus in 6 of 24 informative cases (25%) compared to normal blood DNAs from the same patients. Northern blot analysis showed normal size RB1 mRNA in all the tumor samples. However, there was a 2-5-fold increase in the level of expression of the RB1 gene in all the tumor samples compared to the WI38 cell line which was used as control. Western blot analysis of the RB1 protein, pRb showed a 2.5-5-fold increase in the level of total pRb as compared to normal WI38 cell line. Sixty five to seventy five percent of the total pRb were in phosphorylated form in most tumors. The LOH at the RB1 gene locus suggests genetic instability in these patients. Further, increased levels of RB1 mRNA, total pRb and the phosphorylated form of pRb suggests that RB1 gene in these tumors may have anti-apoptotic function. These results suggest that the RB1 gene has a major role in the development of human vestibular schwannomas.

Adolescent↗
PubMed2004

Purification of a Class B1 platelet aggregation inhibitor phospholipase A2 from Indian cobra (Naja Naja) venom.

A platelet aggregation inhibitor phospholipase A(2) (NND-IV-PLA(2)) was isolated from Naja naja (Eastern India) venom by a combination of cation and anion exchange chromatography. NND-IV-PLA(2) is the most catalytically active enzyme isolated from the Indian cobra venom. The acidic PLA(2) profile of Eastern regional Indian cobra venom is distinctly different from that of the western regional venom. However the acidic PLA(2)s from both the regions follow the pattern of increasing catalytic activity with increase in acidic nature of the PLA(2) isoform. NND-IV-PLA(2) is a Class B1 platelet aggregation inhibitor and inhibits platelet aggregation induced by ADP, collagen and epinephrine. Modification of active site histidine abolishes both catalytic activity and platelet aggregation inhibition activities while aristolochic acid, a phospholipase A(2) inhibitor has only partial effect on the two activities.

Adenosine Diphosphate↗
PubMed2003

Differential use of multiple replication origins in the ribosomal DNA episome of the protozoan parasite Entamoeba histolytica.

The factors that control the initiation of eukaryotic DNA replication from defined origins (oris) on the chromosome remain incompletely resolved. Here we show that the circular rDNA episome of the human pathogen Entamoeba histolytica contains multiple potential oris, which are utilized in a differential manner. The primary ori in exponentially growing cells was mapped close to the promoter of rRNA genes in the upstream intergenic spacer (IGS) by two-dimensional gel electrophoresis. Replication initiated predominantly from the upstream IGS and terminated in the downstream IGS. However, when serum-starved cells were allowed to resume growth, the early oris which became activated were located in other parts of the molecule. Later the ori in the upstream IGS became activated, with concomitant silencing of the early oris. When the upstream IGS was located ectopically in an artificial plasmid, it again lost ori activity, while other parts of the rDNA episome could function as oris in this system. Therefore, the activation or silencing of the ori in this episome is context dependent, as is also the case with many eukaryotic replicons. This is the first replication origin to be mapped in this primitive protozoan and will provide an opportunity to define the factors involved in differential ori activity, and their comparison with metazoans.

Animals↗
PubMed2003

Stress-dependent expression of a polymorphic, charged antigen in the protozoan parasite Entamoeba histolytica.

We have identified a novel stress inducible gene, Ehssp1 in Entamoeba histolytica, the causative agent of amebiasis. Ehssp1 belongs to a polymorphic, multigene family and is present on multiple chromosomes. No homologue of this gene was found in the NCBI database. Sequence alignment of the multiple copies, and genomic PCR data restricted the polymorphism to the central region of the gene. This region contains a polypurine stretch that encodes a domain rich in acidic and basic amino acids. Under normal culture conditions only one copy of this multigene family is expressed, as observed by Northern blot and RT-PCR analysis. The size of this copy of the gene is 1,077 nucleotides, encoding a protein of 359 amino acids. The polymorphic domain in this copy is 64 nucleotides long. However, on exposure of cells to stress conditions such as heat shock or oxidative stress, multiple polymorphic copies of the gene are expressed, suggesting a possible role of this gene in adaptation of cells to stress conditions. The gene copy expressed under normal conditions, and the expression profile of cells under heat stress was identical in two different strains of E. histolytica tested. Interestingly, the extent of polymorphism in this gene was very less in E. dispar, a nonpathogenic sibling species of E. histolytica. Ehssp1 was found to be antigenic in invasive amebiasis patients.

Amino Acid Sequence↗
PubMed2001

Clinical significance of falling blood pressure among older adults.

We assessed the prevalence of falling blood pressure among older adults and its relationship to subsequent outcomes, using public use data from four sites of the Established Populations for Epidemiologic Studies of the Elderly. Seventeen percent of subjects had a decrease in systolic blood pressure of 20 mm Hg or greater and 22% had a decrease in diastolic blood pressure of 10 mm Hg or greater between year 0 and year 3. Falling systolic and diastolic blood pressure was associated with increased all-cause mortality (OR 1.5, 95% CI 1.3, 1.7), cardiovascular mortality (OR 1.6, 95% CI 1.3, 1.9) and all cardiovascular events (OR 1.4, 95% CI 1.2, 1.6) in the subsequent 3 years (years 4 to 6). Increasing amount of fall in blood pressure was associated with increasing risk of mortality. The magnitude of effect of falling blood pressure on adverse outcomes declined and became nonsignificant after adjusting for comorbidity and functional status at baseline. Thus, falling blood pressure is common among older adults and is a marker for underlying poor health and subsequent mortality.

Age Distribution↗
PubMed2001

The relationship between blood pressure and mortality in the oldest old.

OBJECTIVES: To explore the relationship between systolic and diastolic blood pressure and risk of 6-year, all-cause mortality in men and women age 65 to 84 versus those 85 and older. DESIGN: A population-based longitudinal study. SETTING: This study was conducted at four different sites: East Boston, Massachusetts; New Haven, Connecticut; two rural counties in Iowa; and Piedmont, North Carolina. PARTICIPANTS: 12,802 community-dwelling persons age 65 and older. MEASUREMENTS: Baseline measurements collected include demographics, self-reported chronic medical conditions, blood pressure measurements, medications, health habits, and hospitalizations. RESULTS: Unadjusted actuarial survival analyses show that men age 65 to 84 years with systolic blood pressure < 130 mmHg have significantly lower mortality compared with those with systolic blood pressure > or = 180 mmHg (P < .0001). In contrast, men 85 and older with systolic blood pressure > or = 180 mmHg have significantly lower mortality compared with those with systolic blood pressure < 130 mmHg (P < .0001). In Cox proportional hazards analyses controlling for other predictors of survival, the hazard of death associated with each 10-mmHg increase in systolic blood pressure is positively associated among men age 65 to 84 years and negatively associated among men age 85 and older (Hazard ratio and 95% confidence interval (CI): 1.04 (1.01, 1.07) for younger men vs 0.92 (0.86, 0.99) for older men). Among women age 65 to 84, the hazard of death significantly increased with increase in systolic blood pressure (P < .0001), while there was no relationship between level of systolic blood pressure and survival in women 85 and older. Both men 65 to 84 years old and those 85 and older showed a negative relationship between diastolic blood pressure and all-cause mortality (Hazard ratio 0.93, 95% CI (0.88-0.97) for men age 65-84 years, and Hazard ratio 0.90, 95% CI 0.80-1.02 for men 85 and older). CONCLUSION: In men age 85 and older, higher systolic blood pressure is associated with better survival.

Aged↗
PubMed2001

Chronic rheumatologic symptoms in a tri-ethnic sample of men and women aged 75 and older.

BACKGROUND: The high prevalence of musculoskeletal symptoms in elderly persons tends to obscure the recognition of specific medical conditions. The purpose of this study is to describe the prevalence of chronic rheumatologic symptoms and the associated measures of health status in an older population. METHODS: This is a cross-sectional study of 507 noninstitutionalized tri-ethnic men and women aged 75 and older living in Galveston County, Texas. A home interview collected data on demographics, chronic medical conditions, cognition, depression, and functional status. Site, severity, and duration of rheumatologic symptoms such as morning stiffness, body tenderness, and body aching in the past month were also collected. RESULTS: There was a high prevalence of nonspecific rheumatologic symptoms such as morning stiffness (32% in the shoulder girdle, 31% in the hip girdle), tenderness to touch (9%), and generalized body aching (11%) in the study population. Twenty-one percent of the subjects reported either bilateral shoulder or hip girdle stiffness or tenderness lasting more than 30 minutes almost every day or every day or generalized body aching most of the time during the past month. Age-, gender-, and ethnicity-adjusted multivariate analyses showed that more than three self-reported chronic medical conditions, poor or fair self-reported health, impairment in instrumental activities of daily living (IADL), and the presence of depressive or anxiety symptoms were associated with the presence of these chronic rheumatologic symptoms. CONCLUSION: Chronic rheumatologic symptoms are common in people aged 75 and older. Such symptoms are markers for underlying poor health and for anxiety and depression among older subjects.

Activities of Daily Living↗
PubMed2000

The genome of Entamoeba histolytica.

Estimation of genome size of Entamoeba histolytica by different methods has failed to give comparable values due to the inherent complexities of the organism, such as the uncertain level of ploidy, presence of multinucleated cells and a poorly demarcated cell division cycle. The genome of E. histolytica has a low G+C content (22.4%), and is composed of both linear chromosomes and a number of circular plasmid-like molecules. The rRNA genes are located exclusively on some of the circular DNAs. Karyotype analysis by pulsed field gel electrophoresis suggests the presence of 14 conserved linkage groups and an extensive size variation between homologous chromosomes from different isolates. Several repeat families have been identified, some of which have been shown to be present in all the electrophoretically separated chromosomes. The typical nucleosomal structure has not been demonstrated, though most of the histone genes have been identified. Most Entamoeba genes lack introns, have short 3' and 5' untranslated regions, and are tightly packed. Promoter analysis revealed the presence of three conserved motifs and several upstream regulatory elements. Unlike typical eukaryotes, the transcription of protein coding genes is alpha-amanitin resistant. Expressed Sequence Tag analysis has identified a group of highly abundant polyadenylated RNAs which are unlikely to be translated. The Expressed Sequence Tag approach has also helped identify several important genes which encode proteins that may be involved in different biochemical pathways, signal transduction mechanisms and organellar functions.

Animals↗
PubMed2000

Vertebral artery aneurysms.

Vertebral artery (VA) aneurysms are rare. We present our experience with three cases of VA aneurysms. Two aneurysms were located close to the origin of basilar artery while the third patient had a giant posterior inferior cerebellar artery aneurysm. These aneurysms were operated by the far lateral inferior suboccipital approach with good results.

Adolescent↗
PubMed1999

Aging versus disease: the opinions of older black, Hispanic, and non-Hispanic white Americans about the causes and treatment of common medical conditions.

BACKGROUND: Little is known about how older people interpret disease and how those interpretations might relate to use of medical services. OBJECTIVE: To assess opinions of older subjects about the cause and treatment of common diseases and how they are related to health behaviors. DESIGN: In-home interview of a population-based sample (n = 601) of noninstitutionalized black, Hispanic, and non-Hispanic white American men and women aged 75 and older in Galveston County, Texas. RESULTS: Substantial proportions of the subjects considered heart disease, arthritis, or difficulty sleeping to be a normal part of aging. In multivariate analyses including age, gender, education, marital status, living arrangement, global self-rating of health, and comorbidity, older black subjects were less likely to view heart disease (OR = 0.41; 95% CI, 0.26-0.64), arthritis (OR = 0.48; 95% CI, 0.31-0.73), or sleep problems (OR = 0.50; 95% CI, 0.32-0.77) as a normal part of aging than were non-Hispanic whites. Blacks were more than three times as likely to attribute heart disease to overwork or stress than were non-Hispanic whites. In multivariate analyses, subjects who considered all three of the medical conditions to be a normal part of aging ("fatalistic") were less likely to have received preventive medical services in the previous year (OR = 0.13; 95% CI, 0.02-0.96), and subjects who felt that nothing could be done to treat any of the conditions ("nihilistic") were less likely to have a regular physician (OR = 0.24; 95% CI, 0.08-0.74). CONCLUSIONS: Substantial numbers of older subjects are fatalistic about the cause of disease and/or nihilistic about its treatment. These attitudes are associated with decreased utilization of health services. Attempts to improve the health of underserved groups should employ interventions that are sensitive to the health beliefs of the targeted group.

Black or African American↗
PubMed1998

Undertreatment of hypertension in older Mexican Americans.

OBJECTIVE: To identify the prevalence of hypertension and factors associated with nontreatment and poor control of hypertension in Mexican Americans aged 65 years and older. DESIGN: A population-based survey of older Mexican Americans conducted in 1993-1994. SETTING: Subjects residing in five Southwestern states: Texas, New Mexico, Colorado, Arizona, and California. PARTICIPANTS: An area probability sample of 3050 noninstitutionalized Mexican American men and women aged 65 and older took part in a 90-minute in-home interview, which included review of all medications taken and two sitting blood pressure measurements. OUTCOME MEASURES: Measured were previous diagnoses of hypertension, current medication for hypertension, and current blood pressure RESULTS: Sixty-one percent of older Mexican-Americans were hypertensive, and 51% of those with hypertension were taking antihypertensive medications. Only 25% of hypertensive subjects (18% of males and 30% of females) were in good blood pressure control (i.e., systolic blood pressure < 140 mm Hg and diastolic blood pressure < 90 mm Hg). In multivariate analyses, factors associated with increased likelihood of treatment included female gender (OR = 1.9), history of heart disease (OR = 2.4), possessing a regular source of health care (OR = 2.7), and having seen a physician two or more times in the previous year (OR = 3.8). These were also independent predictors of good blood pressure control. CONCLUSION: Nontreatment of hypertension is still a major public health concern in older Mexican Americans. We estimate that adequate blood pressure control in this population would prevent approximately 30,000 adverse cardiovascular events over 10 years, affecting approximately 6% of the entire Mexican American older population.

Aged↗
PubMed1996

Geriatric targeting criteria as predictors of survival and health care utilization.

OBJECTIVE: To assess the utility of geriatric targeting criteria in predicting survival and health care utilization in a cohort of hospitalized older veterans. DESIGN: A prospective cohort study assessing geriatric targeting criteria, e.g., polypharmacy, falls, or confusion, with respect to adverse outcomes at 12 months. SETTING: A Tertiary Care VA Medical Center. PATIENTS: 507 acutely hospitalized male veterans aged 65 years or more. MAIN OUTCOME MEASURES: Survival status, nursing home placement, and total hospital days during 12 months following hospital admission. RESULTS: Patients who had a higher number of targeting criteria at admission showed a significantly increasing trend toward death (P < or = .001), nursing home placement (P < or = .01), and longer hospital stays (P < or = .01) at 12 months. In univariate analyses, weight loss (relative hazard 3.8, 95% CI 2.4, 5.9), appetite loss (relative hazard 3.3, 95% CI 1.9, 5.8), depression (relative hazard 2.5, 95% CI 1.4, 4.5), falls (relative hazard 2.2, 95% CI 1.2, 4.1), confusion (relative hazard 2.2, 95% CI 1.2, 4.0), and socioeconomic problems (relative hazard 1.6, 95% CI 1.0, 2.5) predicted death. Polypharmacy (OR 3.4, 95% CI 1.3, 8.8), confusion (OR 4.4, 95% CI 1.5, 13.0), and prolonged bedrest (OR 7.6, 95% CI 1.5, 39.3) predicted nursing home placement. Confusion (Beta 12.0, 95% CI 2.9, 21.3), falls (Beta 14.2, 95% CI 4.2, 24.3), and prolonged bedrest (Beta 22.4, 95% CI 3.9, 41.0) predicted total hospital days. In multivariate analyses, weight loss, depression, and socioeconomic problems predicted death; confusion and polypharmacy predicted nursing home placements; and falls predicted total hospital days. CONCLUSION: This prospective cohort study of hospitalized older veterans demonstrated geriatric targeting criteria as predictors of adverse hospital outcomes. Our findings suggest screening acutely hospitalized patients using chart abstracted geriatric targeting criteria is useful in identifying patients at risk for adverse outcomes of hospitalization.

Activities of Daily Living↗
PubMed1995

Prognosis of extradural haematomas in children.

102 children treated surgically for intracranial extradural haematoma from 1982 to 1991 were evaluated retrospectively and their prognosis was compared with 387 adults treated during the same period. Children had a better prognosis than adults even with a low Glasgow Coma Scale (GSC) score at surgery. Children had a higher incidence of frontal and posterior fossa haematomas. The GCS score and the associated parenchymal injuries had a strong correlation with the outcome both in adult and children, whereas the site of haematoma had no correlation with the final outcome.

Adolescent↗
PubMed1989

Primary biodegradation of linear alkyltoluene and alkylbenzene sulfonates.

Studies on the primary biodegradation of linear dodecylbenzene sulfonate, linear dodecyltoluene sulfonate, linear C(10-14) benzene sulfonate, linear C(10-14) toluene sulfonate, commercial samples of linear C(10-14) benzene sulfonate and branched dodecylbenzene sulfonate (DDBS) were carried out using a microbial culture developed from garden soil. Results show that linear alkyl toluene (LAT) is as degradable as linear alkylbenzene (LAB) in 7 days. However, a slower rate of degradation was noted with LAT. Various distributions of the positional isomers of the phenyl ring in the alkane chain of C(10-14) LAB showed no change in the pattern of primary biodegradation.

Journal Article↗
PubMedDate not supplied

Factors influencing unawareness of hypertension among older Mexican Americans.

BACKGROUND: The objective of the study was to identify factors associated with unawareness of hypertension among Mexican Americans age 65 years and older. METHODS: This was a population-based survey of 3,050 older Mexican Americans conducted in five Southwestern states in 1993-1994. An in-home interview included sociodemographics, review of medications, and blood pressure measurements. RESULTS: Sixty percent of all subjects were hypertensive, and 37% of these were unaware of their diagnosis. Unaware hypertensive had significantly higher mean blood pressures than did aware hypertensives (145.7/ 86.2 mm Hg vs 142.4/83.1 mm Hg). While 77% of aware hypertensives were treated, only 10% of unaware hypertensives were treated. In multivariate analyses, factors associated with unawareness included male gender (OR = 1.8), being married (OR = 1.6), having Medicaid (OR = 1.6), having made fewer than two visits to a doctor in the past year (OR = 2.8), having a history of heart disease (OR = 0.57) or stroke (OR = 0.37), and having poor self-reported health (OR = 0.43). CONCLUSION: Despite 3 decades of hypertension detection and education programs, unawareness of hypertension remains high among older Mexican Americans. There is a continued need for community-based education programs for hypertensives who are unaware of their diagnosis, and also there is need for programs to increase access to primary care physicians.

Aged↗
PubMedDate not supplied

Co-occurrence of Wilson's disease and glioblastoma multiforme--is it a chance association?

We report a patient with glioblastoma multiforme who was subsequently diagnosed to have Wilson's disease. Immunohistochemical studies of the tumor revealed high (> 60%) labeling index for p53 and Rb retinoblastoma protein. Whether this association is like the co-occurrence of retinoblastoma and Wilson's disease due to possible somatic mutation in chromosome 13 needs to be explored.

Adolescent↗