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Biomedical subjects

G Agarwal

Publications and source records attributed to G Agarwal.

At least 55 records · Page 3Linked to original sources
PubMed1998

Safety and tolerance of medical nutritional products as sole sources of nutrition in people on hemodialysis.

OBJECTIVE: Establish and compare the safety and tolerance of three medical nutritional products when used as sole sources of nutrition in stable hemodialysis patients. DESIGN: Prospectively randomized, controlled, single blind, parallel design. SETTING: Three outpatient hemodialysis clinics. PARTICIPANTS: Seventy-nine normally nourished, stable, anuric, adequately dialyzed, adult outpatients with end-stage renal disease (ESRD) and requiring thrice weekly hemodialysis. INTERVENTION: A 3-week trial was conducted. During the first week, baseline medical history and physical examination, gastrointestinal symptom, urea kinetic, bowel habit, and biochemical data were collected while participants ingested their usual diet. During the last 2 weeks, the same data were collected while participants orally ingested 35 kcal/kg actual weight/d of one of three medical nutritional products as a sole source of nutrition. Products were a standard medical nutritional (EN-9527) and two renal nutritionals (EN-9528 and EN-9529). The latter product was a reformulation of EN-9528 and contained added beta-carotene and fructooligosaccharides. MAIN OUTCOME MEASURES: Gastrointestinal symptoms, bowel habits (stool frequency and consistency), routine blood chemistries, urea kinetics, and normalized protein catabolic rate (nPCR) RESULTS: All three groups achieved a mean energy and protein intake of approximately 35 kcal/kg/d and 1.25 g protein/kg/d during the last 10 days of the sole source feeding period. Adherence with the formula ingestion targets was assessed using both a patient-completed product consumption log and nPCR. By intent to treat analysis, there were no changes in number or severity of gastrointestinal symptoms, stool frequency or stool consistency, or urea kinetics between the baseline week and during product consumption. In comparison to the standard formulation, the disease-specific formulations resulted in improved serum phosphorus and calcium-phosphorus product. Patients receiving the fructooligosaccharide-containing product (EN-9529), by Chi-squared analysis, had less constipation than for the comparable product without oligosaccharides (EN-9528) or the standard medical nutritional (EN-9527). CONCLUSION: Use of enteral nutritionals as a sole source of nutrition is both possible and well tolerated in hemodialyzed patients. Selection of a disease-specific formulation offered advantages over a standard formulation in the management of biochemical complications of renal disease when the products were used as a sole source of nutrition.

Blood Urea Nitrogen↗
PubMed1998

Vitiligo: an under-estimated problem.

BACKGROUND AND OBJECTIVES: Vitiligo is a common skin complaint, affecting approximately 500000 people in the UK with cosmetically and psychologically devastating effects. An average GP will have 10 sufferers on his list. The aims of this survey were to determine the effects and extent of vitiligo, treatments used and whether these differed from those reported in the current medical literature. There has been no previous work in this area. METHOD: A self-administered questionnaire was distributed to 25% of the members of the Vitiligo Society (a patients' self-help group) who were likely to be concerned about their condition. The questionnaire covered demographic characteristics of the group, the vitiligo itself, treatment and sufferers attitudes towards vitiligo. RESULTS: The response rate was 77%: the median age of onset was 13 years. Half related the onset of their vitiligo to a stressful event (e.g. marital and financial problems). Only 14% had noticed any spontaneous improvement in their vitiligo [negatively related to the percentage of vitiligo on the body (P < 0.05)]; 80% had used no treatment. Use of camouflage was high (41% of males and 70% of females). Sunscreen use was suboptimal, and 20% were depressed about their vitiligo. DISCUSSION: In this self-help group it appears that improvement occurs less frequently with more extensive vitiligo, so treatment (for vitiligo and depression) should be offered early. Further work on this subject is needed. GPs should be ideally placed to help vitiligo sufferers. The suboptimal use of therapies suggests that GPs need education about the topic.

Adolescent↗
PubMed1997

Intraoperative ultrasonography for insulinoma: a preliminary experience.

BACKGROUND: A majority of insulinomas are benign and intrapancreatic. Because surgery is curative in 90% of cases, and almost 60% are not detected by preoperative imaging studies, precise intraoperative localization is essential. Recently, the use of high-resolution real-time ultrasonography has facilitated intraoperative detection. METHODS: Intraoperative ultrasonography using a high-frequency probe was performed in four patients with biochemically proven insulinomas. RESULTS: Ultrasonography helped to localize the insulinomas, and also helped in surgical decision-making by accurately documenting the relationship of the tumor to vital structures. CONCLUSION: Besides its ability to find islet cell tumors, intraoperative ultrasonography also affects surgical decision-making.

Humans↗
PubMed1996

Nocturnal blood pressure in treated hypertensive African Americans Compared to treated hypertensive European Americans.

Previous studies have shown that African Americans (blacks) tend to have higher nocturnal blood pressure than European Americans (whites). The study presented here was undertaken to determine whether treatment of hypertension influences nocturnal blood pressure differently in blacks than in whites. To answer this question, this study measured nocturnal blood pressure by ambulatory blood pressure monitoring (ABPM) in treated hypertensive blacks and whites whose daytime blood pressures were comparable. Inclusion criteria for this study were: diagnosis of essential hypertension, absence of renal failure, and documentation of antihypertensive therapy, diabetic status, proteinuria status, and body weight. All of the black patients in our programs who underwent ABPM and met the above criteria were included in this study. White patients were included on the basis of having the same inclusion criteria as blacks and showing, by ABPM, daytime mean arterial pressure (MAP) in the same range as that of the blacks selected for this study. The results of nocturnal blood pressure were unknown to the investigators when the patients were selected for this study. In the blacks (N = 62) and whites (N = 72) selected for study, the mean daytime (0600 to 2200 h) MAP was 107 +/- 1 SE mm Hg for both the black and white cohorts. To assess nocturnal blood pressure, the period from 0100 to 0500 h was chosen because it likely encompassed an interval of sleep, which is associated with the nadir of nocturnal blood pressure. This interval was termed 0100 to 0500 h, "middle night." Mean middle night MAP was 97 +/- 12 mm Hg in blacks versus 90 +/- 14 mm Hg in whites (P < 0.006, unpaired t test). The greater middle night MAP in blacks compared with whites was a result of the higher diastolic pressure in blacks (80 +/- 11 mm Hg) versus whites (75 +/- 11 mm Hg) (P = 0.003). Mean middle night systolic blood pressure was numerically higher in blacks than whites (131 +/- 18 mm Hg versus 128 +/- 17 mm Hg), but this difference did not achieve statistical significance. The higher middle night blood pressure in blacks versus whites could not be explained by differences between the groups in daytime MAP, age, gender, body weight, serum creatinine level, proteinuria, diabetic status, or greater use of short-acting antihypertensive agents in blacks versus whites. It was concluded that when treated hypertensive blacks and whites are matched for the same daytime blood pressure, blacks tend to have significantly higher nocturnal blood pressure than whites. The magnitude of this difference suggests that it could contribute importantly to the greater target-organ damage that is seen in hypertensive blacks compared with hypertensive whites.

Antihypertensive Agents↗
PubMed1995

Identification of nonlinear model of ankle joint dynamics during electrical stimulation of soleus.

The mechanical impedance of the ankle joint was estimated in two conditions: during submaximal surface electrical stimulation of the soleus muscle, and with no stimulation applied. Both neurologically intact (n = 5) and spinal cord injured subjects (n = 4) were used. The mechanical impedance was measured by applying angular step and constant velocity (13-100 degrees s-1) perturbations at 10 degrees to the ankle and measuring the resulting changes in torque. A five-element lumped model consisting of an inertial element, a parallel elastic element, and an elastic element in series with a viscous element and a pure tension generator produced a good fit for predicting the compliance characteristics of the ankle for both the relaxed and stimulated conditions. The elastic elements were piecewise linear with different values for the dorsiflexion and plantarflexion directions. The viscous element was velocity-dependent and it decreased in value as the velocity increased. The average torque error between the measured and model's response during soleus stimulation was 10.56% for the dorsiflexed and 11.93% for the plantarflexed perturbations. However, the average error was skewed by several subjects who had excessive error, due to volitional intervention or flexor withdrawal reflex. The average model error for the perturbations without stimulation was 7.12% for dorsiflexed and 5.58% for plantarflexed perturbations.

Ankle Joint↗
PubMed1994

Determining appropriate models for joint control using surface electrical stimulation of soleus in spinal cord injury.

The mechanical impedance of the ankle joint during electrical stimulation of the soleus is studied by applying constant-velocity 10 degrees angular perturbations to the ankle and measuring the resultant torque. Both neurologically intact subjects and spinal cord injured subjects are tested. Lumped, piecewise linear models are developed to predict the torque from the measured displacement and acceleration signals. The commonly used second-order mass-spring-dashpot model fails to predict the changes in torque that occur following imposed movements. A five-element, directionally-dependent piecewise linear model is much better at predicting the measured responses for velocities up to 50 degrees s-1. Numerical least squared error identification techniques are used to estimate the model parameters for three neurologically intact and three spinal cord injured subjects. The average error between the model's response and the measured response across all subjects is 10.9%. There is some evidence that a velocity-dependent non-linear model could produce better results than the directionally-dependent piecewise linear model.

Ankle Joint↗
PubMed1984

An integrative approach to intracranial hydraulic physiology. I. Basic concepts, pressure-volume relationships, and infusion studies.

A computer simulation of the anatomy of the intradural fluid compartment is used to explore intracranial hydraulic physiology. It examines the mutual interactions of fluid flow rates, volumes, and pressures that control the physiology of the intracranial fluid. The mechanisms of change in intracranial pressure despite the fixed volume constraint are elucidated. The physical origins of the pressure-volume curve and data on the infusion of cerebrospinal fluid are examined. The dynamic behavior of this passive system closely simulates the observed physiologic response to bolus infusion, constant rate infusion, hypercapnia- hypocapnea , and hydrocephalus.

Brain↗
PubMed1977

Awareness during anaesthesia. A prospective study.

One hundred and thirty-eight patients were anaesthetized using a nitrous-oxide-oxygen technique with neuromuscular blockage under standard conditions. None showed any evidence of awareness during the course of anaesthesia, irrespective of the type of premedication used.

Adolescent↗
PubMedDate not supplied

Clinical profile and prognosis of Addison's disease in India.

BACKGROUND: The clinical presentation of primary adrenocortical insufficiency (Addison's disease) in India may differ from that in developed countries. We therefore studied the clinical profile and prognosis of Addison's disease, with special reference to patients with tuberculous infection. We also evaluated the utility of various clinical parameters in differentiating tuberculous from idiopathic Addison's disease. METHODS: In a retrospective and prospective study, 45 consecutive patients of Addison's disease (20 patients with tuberculous aetiology) were studied for their clinical features, autoantibody profile (adrenal cytoplasmic, thyroid microsomal and gastric parietal cell antibodies) and prognosis. RESULTS: A tuberculous aetiology was present in 47% of the patients and of these, 85% had enlargement of one or both adrenal glands. While patients with tuberculous Addison's disease had a higher prevalence of extra-adrenal tuberculosis (55% v. 9%, p = 0.001), a lower frequency of adrenal cytoplasmic antibodies (17% v. 50%, p = 0.03) and parietal cell or thyroid microsomal antibodies (11% v. 55%, p = 0.004), a considerable overlap was observed. Despite adverse circumstances, during a mean follow up of 3.3 years, only 2 (5%) patients died, neither of whom had tuberculous involvement. Five (13%) patients suffered from one or more episodes of Addisonian crises, though none of these resulted in mortality. CONCLUSION: Tuberculosis remains an important cause of Addison's disease in India. The presence of extra-adrenal tuberculosis, or lack of adrenal cytoplasmic antibodies, does not, with certainty, differentiate between a tuberculous and idiopathic aetiology. The prognosis of Addison's disease was good despite unfavourable circumstances.

Addison Disease↗
PubMedDate not supplied

The clinical spectrum of fibrocalculous pancreatic diabetes in north India.

BACKGROUND: Fibrocalculous pancreatic diabetes (FCPD) is a secondary form of diabetes, unique to tropical countries. In earlier reports, patients with FCPD had severe insulin-requiring diabetes, malnutrition and a dismal prognosis. With Improvements in nutrition and medical care, the presentation and prognosis of FCPD may have changed. We report on the clinical profile and prognosis of a cohort of FCPD patients from north India and compare our findings with earlier reports. METHODS: Eighty consecutive FCPD patients who presented to the Diabetes, Gastroenterology and Surgical Gastroenterology services were evaluated for their nutritional status, clinical presentation, beta-cell function (fasting C-peptide) and exocrine function (faecal chymotrypsin). All patients diagnosed between 1994 and 2000 (n = 32) were followed prospectively for weight gain and glycaemic control. RESULTS: Only 55% of FCPD patients had a low body mass index (< 18 kg/m2). At the time of diagnosis of diabetes, only 26 (33%) patients presented with severe insulin-requiring diabetes; these patients were younger [23.7 (8.3) years v. 28.7 (10.6) years, p = 0.04], and had higher haemoglobin A1c [9.7 (3.8)% v. 7.3 (2.6)%, p = 0.005] than those requiring diet control or oral hypoglycaemic agents. FCPD patients had a wide range of fasting serum C-peptide (0.03-0.76 nmol/L). C-peptide was negatively associated with increasing duration of diabetes (r = -0.48, p = 0.001), but there was no correlation with faecal chymotrypsin. On prospective follow up (mean 2.3 years), there was significant improvement in body mass index [19.4 (2.9) kg/m2 v. 17.0 (3.7) kg/m2, p < 0.01] and haemoglobin A,c [6.4 (1.6)% v. 8.0 (3.0)%, p < 0.001]. CONCLUSION: FCPD patients differed from those described in earlier reports in many respects, Including improved nutritional status, a wide range of 3cell function and a more favourable prognosis.

Adolescent↗
PubMedDate not supplied

The first man/machine interaction in medicine: the pulsilogium of Sanctorius.

This article, published in lieu of the customary feature, artifact, describes one of the earliest medical devices--a device to measure pulse rate. A close examination of the pulsilogium of Sanctorius of Padua (1561--1636) reveals it to be something more than the first measuring device in medical history; it is also the first man/machine system in medicine. Using a systems approach, pulsilogium and physician interaction is found to contain important dynamic characteristics. The device is operated in a negative feedback mode, employs the concept of transduction, and measures pulse through another dimension--length. More than 100 years after its invention, the pulsilogium found useful application by de la Croix in measurements of cardiac function during "electrification."

History, 16th Century↗