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Biomedical subjects

S Seshadri

Publications and source records attributed to S Seshadri.

At least 37 records · Page 2Linked to original sources
PubMed1997

Lifetime risk of dementia and Alzheimer's disease. The impact of mortality on risk estimates in the Framingham Study.

We estimated the remaining lifetime risks of developing Alzheimer's disease (AD) and dementia from all causes, based on data from longitudinal population studies. The risk of developing AD during one's lifetime depends on both disease incidence and life expectancy. Conventional estimates of cumulative incidence overestimate the risk when there is a substantial probability of mortality due to competing causes. A total of 2,611 cognitively intact subjects (1,061 men, 1,550 women; mean age, 66 +/- 7 years) were prospectively evaluated for the development of AD or other dementia. A modified survival analysis was used to estimate both cumulative incidence and the sex-specific remaining lifetime risk estimates for quinquennial age groups above age 65 years. Over a 20-year follow-up period, 198 subjects developed dementia (120 with AD). The remaining lifetime risk of AD or other dementia depended on sex, being higher in women, but varied little with age between 65 and 80 years. In a 65-year-old man, the remaining lifetime risk of AD was 6.3% (95% CI, 3.9 to 8.7) and the remaining lifetime risk of developing any dementing illness was 10.9% (95% CI, 8.0 to 13.8); corresponding risks for a 65-year-old woman were 12% (95% CI, 9.2 to 14.8) and 19% (95% CI, 17.2 to 22.5). The cumulative incidence between age 65 and 100 years was much higher: for AD, 25.5% in men and 28.1% in women; for dementia, 32.8% in men and 45% in women. The actual remaining lifetime risk of AD or dementia varies with age, sex, and life expectancy and is lower than the hypothetical risk estimated by a cumulative incidence in the same population.

Aged↗
PubMed1996

Technology assessment methods for radiology systems.

This article discusses the strengths and weaknesses of technology assessment methods for the evaluation of novel and complex radiology systems, including picture archiving and communication systems (PACS), computed radiography (CR), teleradiology, and other new models for the delivery of radiology services. Using examples from PACS and CR, we review early economic assessments of PACS from the radiology department. We then broaden our perspective to discuss the analytic criteria that can be used to evaluate economic analyses of PACS as the health care delivery system shifts toward managed care. We close with a proposal for optimizing the integration of information technology into the clinical environment through ongoing target data collection during the implementation of new radiology systems.

Cost Savings↗
PubMed1995

Apolipoprotein E epsilon 4 allele and the lifetime risk of Alzheimer's disease. What physicians know, and what they should know.

BACKGROUND: Published studies now show a clear association between Alzheimer's disease (AD) and the apolipoprotein E epsilon 4 allele (APOE* epsilon 4). The clinical value of this information to estimate a healthy individual's lifetime risk of AD has not been well delineated. Physicians dealing with AD may not know either the lifetime risk of developing AD or the effect of the APOE genotype on this risk. Because the lifetime risk of AD depends in part on life expectancy, and available figures on APOE are not population based, a computation is necessary to derive risk estimates useful to physicians. OBJECTIVES: To estimate the lifetime risk of AD and the effect of APOE genotype information on that risk and to assess the knowledge of these risks among physicians who manage patients with dementia. DESIGN: Estimation of risk of AD and survey of physician awareness. The lifetime risk of developing AD without APOE genotype information was first computed for 65-year-olds from existing epidemiologic studies of age-related AD incidence and an actuarial life-table analysis. Using this computed a priori risk of AD and published studies of APOE genotypes in individuals with and without AD, we used a Bayesian analysis to determine the risk of developing AD, with and without an APOE* epsilon 4 allele, for unaffected 65-year-olds. To assess physician knowledge of the lifetime risk of AD and the effect of APOE genotyping on the risk, 50 neurologists, internists, geriatricians, geriatric psychiatrists, and family physicians who manage patients with dementia were randomly selected to participate in a questionnaire-driven telephone survey. RESULTS: In a person with no family history of AD, the epidemiologic/actuarial lifetime risk of AD is approximately 15%. Based on a Bayesian calculation and published APOE data, the lifetime risk of AD is 29% for individuals with one APOE* epsilon 4 allele and it is 9% if no APOE* epsilon 4 allele is present. Physician awareness survey results were as follows: 42% of physicians correctly estimated the approximate lifetime risk of AD; of these, only one third were moderately sure of their response. Only three physicians correctly estimated the change in risk given the APOE* epsilon 4 genotype; only one of these was at least moderately sure. CONCLUSIONS: Determining the APOE* epsilon 4 status of healthy adults with no family history of AD approximately doubles (for the epsilon 4 allele) or reduces by 40% (for the non-epsilon 4 allele) the uninformed lifetime risk of developing AD. Even with an APOE* epsilon 4 allele, the lifetime risk remains below 30%. Most physicians managing patients with AD do not know the lifetime risk of AD, and very few know how APOE* epsilon 4 status modifies the risk. These clinically relevant risk figures should be more widely disseminated among physicians.

Actuarial Analysis↗
PubMed1995

A quantitative model for prediction of iron bioavailability from Indian meals: an experimental study.

The major goal of the study was to explore the possibility of developing an updated model that integrates the effect of various enhancers and inhibitors for predicting the potential availability of iron from typical Indian vegetarian meals. The interaction effects of four constituents namely ascorbic acid, citric acid, tannic acid and calcium phosphate was studied using a standard cereal meal (STD meal) providing 3 mg non-heme iron/250 ml homogenate. Based on the data, a regression equation was evolved which was tested for its predictive power as applied to a set of 10 typical Indian meals. Regression analysis of the data revealed that both ascorbate and citrate emerged as equally strong enhancers while tannate and calcium phosphate demonstrated strong inhibitory effect on iron availability in the STD meal. Further, when the prediction equation, generated on the basis of the interaction effect data was applied to the typical Indian meals, it showed a high correlation coefficient (r = 0.76) between the analysed values for iron availability vs the values computed using the enhancer and inhibitor contents of the meals. Comparison with the only other model available in the literature namely that of Monsen & Balintfy (1982) revealed that the present model was far better in predicting iron availability from cereal based Indian meals (r = 0.76) than Monsen's model (r = 0.19). The findings of the present study substantiated the hypothesis that a regression model, evolved from a cereal meal, by integrating the effect of enhancers as well as inhibitors, rather than only enhancers, provides a more precise estimate of iron availability from typical Indian meals. A limitation of the model however, was that phytate could not be incorporated into the equation.

Ascorbic Acid↗
PubMed1994

Thermally denatured ribonuclease A retains secondary structure as shown by FTIR.

Fourier transform-infrared (FTIR) spectroscopy has been used to test for the presence of nonrandom structure in thermally denatured ribonuclease A (RNase A) at pH* 2.0 (uncorrected pH measured in D2O). The amide I spectral region of the native and thermally denatured protein was compared. A substantial decrease in the amount of beta-sheet and alpha-helix and a corresponding increase in the amount of turn and unordered structure was observed on thermal denaturation. The results indicate that thermally denatured RNase A contains significant amounts of secondary structure (11% helix and 17% beta-sheet), consistent with previous results reported for circular dichroism, and with a relatively compact structure, as revealed by dynamic light scattering. These results are in contrast to those of amide protection experiments reported recently [Robertson, A.D., & Baldwin, R.L. (1991) Biochemistry 30, 9907-9914] which indicated no stable hydrogen-bonded structure under these experimental conditions. Possible explanations for this apparent discrepancy are given.

Animals↗
PubMed1994

In vitro availability of iron from cereal meal with the addition of protein isolates and fenugreek leaves (Trigonella foenum-graecum).

In vitro iron availability was determined from a standard cereal meal (C) with and without the addition of protein isolates from bovine milk (BP), groundnut milk (GP) and soybean milk (SP). A second set of studies were done to investigate the potentially available iron from fenugreek leaves per se and the effect of their addition on the available iron from the cereal meal. The potentially available iron from the meal increased from 4.91% to 6.73% on the addition of BP. The next best enhancer was GP (4.91% to 6.17%). Although the addition of SP increased the total iron content of the cereal meal significantly, the percent available iron decreased compared to the other milk proteins. The addition of fenugreek leaves (100 g/meal) to the meal increased the total iron content of the meal significantly (3.24 mg to 9.12 mg) (p < .001), however, the available iron was observed to decrease (4.91% vs 4.34%).

Biological Availability↗
PubMed1994

Botulinum toxin A in blepharospasm and hemifacial spasm.

We report the first Indian experience of botulinum toxin A in the treatment of blepharospasm and hemifacial spasm. Sixteen patients, 7 with essential blepharospasm, 5 with Meige syndrome and 4 with hemifacial spasm received botulinum toxin A injection. One patient received 3 courses of injections, 2 received 2 courses and the rest received only one course. The effect was observed after a latent period of less than 48 hours in all patients and lasted for a mean of 16.65 weeks. More than 70% improvement occurred after 17/20 injections (85%). Poor response was more often seen when blepharospasm was associated with oromandibular dystonia (2/5 injections). Though the duration of response and subjective score of improvement was best in patients with hemifacial spasm, the numbers were very small for any statistical evaluation. The side effects were local, transient, mild and well tolerated. The commonest side effect was blepharoptosis.

Adult↗
PubMed1993

Characteristics of a child inpatient population with hysteria in India.

OBJECTIVE: This study examined the rate, correlates, and clinical outcome of childhood hysteria in a sample of inpatients in India. For comparison, the rate of this disorder among outpatients was computed. METHOD: Data were derived from case records of inpatient (n = 143) and outpatient admissions (n = 640) during a 1-year interval at the Child and Adolescent Psychiatry Unit of the National Institute of Mental Health and Neurosciences, Bangalore, South India. RESULTS: The diagnosis of hysteria was made in 30.8% (n = 44) of the inpatient and 14.8% (n = 95) of the outpatient samples. The inpatients with hysteria were mostly postpubertal, their gender distribution was approximately even, and pseudo-seizure was the most frequent presentation. These inpatients had a brief duration of illness at admission and short-term outcome was generally positive. CONCLUSIONS: Children with hysterical symptoms form a notable proportion of cases in child guidance and psychiatry clinics in India. It could be that, in this culture, having a "medical" illness is one of the more acceptable means of seeking psychiatric help. The use of a structured and intensive inpatient treatment package appeared to bring about rapid symptom remission. Some of the present findings could be the basis to explore subtypes of childhood hysteria.

Adolescent↗
PubMed1993

Growth performance in anemia and following iron supplementation.

The growth status of anemic (n = 117, Hb 7-10 g/dl) and normal (n = 53, H > or = 11 g/dl) children 3-5 years of age living under similar environmental and socio-economic conditions was evaluated. The dietary intake was assessed on a random subsample of the anemic and normal children. The anemic children had a poorer growth status than normal children as indicated by their significantly (p < 0.001) lower body weight, height and weight for age and significantly (p < 0.001) larger number in Grades II and III malnutrition. Iron supplementation (40 mg elemental iron/day) for six months produced a significant (p < 0.001) increase in Hb levels of both groups (1.6 g/dl in the anemic and 0.8 g/dl in the non-anemic) compared to their respective controls who received sugar placebos. The growth performance of the anemic children supplemented with iron was superior to that of anemic placebo treated children as indicated by a better weight gain and a significantly higher weight for height (p < 0.05). Weight for age was a good differentiator of the anemic from normal while weight for height was a good indicator of the impact of iron supplements on growth.

Anemia↗
PubMed1991

Asymptomatic eosinophilic myocarditis: 2 + 2 = 4 or 5!

A twenty-eight year old man was admitted with a cerebrovascular accident and hypereosinophilia secondary to microfilarial infection. Endomyocardial biopsy revealed focal eosinophilic myocarditis. The intriguing presence of this asymptomatic myocarditis raises interesting possibilities.

Adult↗
PubMed1990

Magnetic resonance imaging simulator: a teaching tool for radiology.

The increasing use of magnetic resonance imaging (MRI) as a clinical modality has put an enormous burden on medical institutions to cost effectively teach MRI scanning techniques to technologists and physicians. Since MRI scanner time is a scarce resource, it would be ideal if the teaching could be effectively performed off-line. In order to meet this goal, the radiology Department at the University of Pennsylvania has designed and developed a Magnetic Resonance Imaging Simulator. The simulator in its current implementation mimics the General Electric Signa (General Electric Magnetic Resonance Imaging System, Milwaukee, WI) scanner's user interface for image acquisition. The design is general enough to be applied to other MRI scanners. One unique feature of the simulator is its incorporation of an image-synthesis module that permits the user to derive images for any arbitrary combination of pulsing parameters for spin-echo, gradient-echo, and inversion recovery pulse sequences. These images are computed in 5 seconds. The development platform chosen is a standard Apple Macintosh II (Apple Computer, Inc, Cupertino, CA) computer with no specialized hardware peripherals. The user interface is implemented in HyperCard (Apple Computer Inc, Cupertino, CA). All other software development including synthesis and display functions are implemented under the Macintosh Programmer's Workshop 'C' environment. The scan parameters, demographics, and images are tracked using an Oracle (Oracle Corp, Redwood Shores, CA) data base. Images are currently stored on magnetic disk but could be stored on optical media with minimal effort.

Computer Simulation↗
PubMed1989

Effect of addition of bovine milk and vegetable milks on the in vitro availability of iron from cereal meals.

Studies were carried out on the in vitro availability of iron from a standard cereal meal with and without the addition of bovine milk (BM), groundnut milk (GM) and soybean milk (SM). Further, availability of iron from these milks per se was also investigated. Estimation of the total iron content from BM, GM, and SM revealed that it was highest in case of SM followed by GM and BM. This trend was reversed for percent available iron which was highest for BM followed by GM and SM. The in vitro availability of iron from the cereal meal was low (3.7%). Addition of BM and GM enhanced the availability of iron from the standard meal whereas SM had no particular enhancing quality. The practical implications of the findings for iron nutrition in humans are discussed.

Animals↗
PubMed1989

Impact of iron supplementation on cognitive functions in preschool and school-aged children: the Indian experience.

Four studies examined impacts of iron supplementation on school children of various ages and both sexes. The first study investigated impact of iron-folic acid supplements for 60 d on cognition in 94 boys and girls aged 5-8 y. Improvement in total scores of the anemics was significantly higher than the nonanemics in 7-8-y-old children only. The second study assessed impacts of supplementation on cognition in 14 pairs of 5-6-y-old anemic boys, with clear beneficial effects on cognitive function. The third study investigated effects of varying dosages of elemental iron on cognitive function in 48 boys aged 8-15 y, with different levels of improvement. The fourth study investigated impacts of iron supplementation on 163 anemic girls aged 8-15 y with treatment and evaluations at 4 and 8 mo, with significantly improved scores in cognitive function after the eighth month.

Adolescent↗
PubMed1985

Haematologic response of anaemic preschool children to ascorbic acid supplementation.

Fifty-four anaemic preschool children, all consuming similar, purely vegetarian, diets were randomly divided equally into an experimental and a control group. The children in the experimental group received 100 mg ascorbic acid twice a day, with lunch and with dinner, for 60 days. The controls received sugar placebos. Initially and at the end of the intervention, haemoglobin (Hb) and red cell morphology were estimated in all children. The children who received ascorbic acid supplements showed a significant improvement in Hb level as well as in red cell morphology, while the controls showed no change. Chemical analysis of the diets of a subsample showed ascorbic acid intakes to be very low.

Anemia↗