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Biomedical subjects

B R Shah

Publications and source records attributed to B R Shah.

At least 19 recordsLinked to original sources
PubMed2000

Increasing rates of ischemic heart disease in the native population of Ontario, Canada.

BACKGROUND: The prevalence of ischemic heart disease (IHD) has been declining in North America since the 1960s. Over this time, Native populations, which have traditionally had low rates of IHD, have undergone striking lifestyle changes that may have had health consequences. In this context, IHD trends in the Native communities of Ontario, Canada, were evaluated. OBJECTIVE: To assess trends in admission rates for IHD in the Native population of Ontario compared with the general population of Ontario. METHODS: A comprehensive administrative database of all hospital admissions in Ontario 1981 to 1997, was used. Age- and sex-adjusted rates of hospital admissions with IHD-related diagnostic or procedure codes were determined in all residents of Ontario communities that had regular census participation and at least 95% of their population claiming Native origins (N=16,874 in 1991). Comparison was made with all residents of the surrounding northern Ontario region (N=822,450) and of the whole province (N = 10,084,885). RESULTS: In 1981, the rate of IHD admissions was similar in all groups, at 99 to 124 per 10,000 persons. By 1997, it decreased to 82 per 10,000 in the province (slope, -1.09; 95% confidence interval, -1.26 to -0.91), with a similar trend in northern Ontario. However, in the Native communities, it increased to 155 per 10,000 (slope, 5.6; 95% confidence interval, 3.8-7.5). A similar trend was seen for acute myocardial infarction admissions, a more precisely coded subset of IHD. Spurious causes of increasing rates were ruled out. CONCLUSIONS: Hospitalizations for IHD have doubled in the Native population despite declining rates in the general population. These findings document an alarming trend in Native health and support the need for further research and targeted intervention.

Hospitalization↗
PubMed1999

Erythropoietin deficiency in hyporeninemia.

The association of anemia and hyporeninemic hypoaldosteronism (HRHA) in type 1 diabetes has been described, and erythropoietin deficiency has been proposed as the cause. Subjects with type 1 diabetes with (n = 8) and without HRHA (n = 11) were studied, as were subjects taking angiotensin-converting enzyme inhibitors (ACEIs; n = 10). Renal function and sodium excretion were estimated with a 24-hour urine collection. Values for hemoglobin, hematocrit, serum erythropoietin, and red blood cell volume were determined. HRHA subjects were anemic (hemoglobin, 99 +/- 8 g/L ), and ACEI subjects had lower hemoglobin concentrations (120 +/- 4 g/L) compared with controls (134 +/- 3 g/L; P < 0.001 and P = 0.01, respectively). Also, the red cell mass in patients with HRHA was significantly less than that in controls (14.8 +/- 1.4 v 20.8 +/- 1.1 mL/kg; P = 0.004), indicating that the lower hemoglobin level in HRHA is not attributable to an expansion of extracellular volume. Erythropoietin levels in the HRHA (27% +/- 11% of predicted) and ACEI groups (43% +/- 9% of predicted) were low compared with controls (94% +/- 13% of predicted; P = 0.001 and P = 0.005, respectively). Renal function was greater than the levels at which anemia becomes a clinical feature in all groups, but creatinine clearance was less in the HRHA (63 +/- 12 mL/min/1.73 m2) and ACEI groups (76 +/- 11 mL/min/1.73 m2) compared with controls (123 +/- 9 mL/min/1.73 m2; P < 0.001 and P = 0.004, respectively). The fractional sodium reabsorption was decreased in HRHA (98.7% +/- 0.3%) and ACEI groups (98.7% +/- 0.3%) versus controls (99.4% +/- 0.1%; P = 0.007 and P = 0.01, respectively). Subjects with type 1 diabetes with HRHA had low hemoglobin concentrations that were caused, at least in part, by inappropriately low serum erythropoietin levels.

Adult↗
PubMed1999

Acute isoniazid exposures and antidote availability.

BACKGROUND: Over the past 10 years the reported incidence of acute isoniazid (INH)-related poisonings has increased, with 507 cases reported in 1996. Parenteral pyridoxine is the antidote for INH-induced seizures, but 5-g aliquot recommended to treat an ingestion of unknown quantity of INH is not always readily available to emergency physicians. OBJECTIVE: To determine the hospital availability of pyridoxine. METHODS: One hundred thirty questionnaires were distributed nationwide to the pharmacies and emergency departments (ED) of hospitals containing pediatric emergency medicine (PEM) fellowships and/or emergency medicine (EM) residencies. Questions were posed regarding the availability, quantity, location, and deemed importance of pyridoxine at each institution. RESULTS: Responses were received from 81% of the hospitals with fellowships and 80% of the hospitals with residencies. Half of the former and one third of the latter reported not having the recommended 5-g aliquot available. Eighty percent of the hospitals with PEM programs and 71% with EM residencies with an adequate stock store it in the hospital's pharmacy, as opposed to in the ED. Thirty-four states were represented, 18 of which have experienced an increase in tuberculosis (TB) from 1993 to 1994; 6/18 (33%) of those did not have the pyridoxine available, and 7/18 (39%) did not deem it necessary. CONCLUSIONS: Our results imply that between one third and one half of the respondents would be ill-equipped to treat acute INH neurotoxicity. Establishing regional distribution centers may alleviate this deficiency, specifically in urban areas with a high incidence or a positive percent increase in TB.

Acute Disease↗
PubMed1998

Specificity of electrocardiographic myocardial infarction screening criteria in patients with nonischemic cardiomyopathies.

BACKGROUND: The 32-point, 54-criteria Selvester QRS scoring system has been successfully used to estimate the size of nonacute myocardial infarction (MI). Three criteria of the system have been shown to be sensitive for the identification of nonacute MI and specific in normal control subjects. The validity of the system has not been tested in patients with cardiomyopathy of nonischemic origin. The purpose of this study was to examine the electrocardiographs (ECGs) of patients with abnormal left ventricular function but no presence of coronary disease to determine the diagnostic specificity of the MI screening criteria subset of the Selvester QRS scoring system. METHODS AND RESULTS: Six hundred ninety patients were considered. Exclusion criteria included age <10 years, cardiac transplantation, thrombolytic therapy, any angiographic evidence of coronary disease, left ventricular ejection fraction (LVEF) >60%, or history of myocardial revascularization. ECG exclusion criteria included left ventricular hypertrophy, right ventricular hypertrophy, left bundle branch block, right bundle branch block, ventricular pacing, left anterior fascicular block, left posterior fascicular block, ventricular preexcitation, and low voltage, because these confounding factors could mimic an infarct on the ECG. The 261 remaining patients were then examined for the presence of the MI screening criteria subset: (1) inferior location: Q > or =30 msec in aVF, (2) anterior location: either any Q or R< or =0.1 mV and < or =10 msec in V2, and (3) posterior location: R> or =40 msec in V1. Thirty-two of the 261 patients falsely met at least 1 of the 3 MI screening criteria, resulting in an overall specificity of 88% (vs 95% in normal control subjects, P=.0006). A specificity of 98% (n = 256) was achieved for the inferior MI screening criterion alone, whereas the anterior and posterior MI screening criteria alone achieved significantly lower specificities: 94% (n = 245) and 95% (n = 249), respectively. When the patient population was divided into LVEF <30% and LVEF > or =30%, no significant association was found between MI screening criteria and LVEF with specificities of 87% and 88%, respectively, for the 2 groups (P= .34). CONCLUSIONS: The MI screening criteria subset is relatively specific in patients with nonischemic cardiomyopathy, falsely identifying only 12% with nonacute MI. However, this specificity is lower than the 95% achieved in normal subjects. Regional accumulation of scarring caused by cardiomyopathy could result in false-positive indication of MI in the present population. Another possibility could be that some patients could have hypertrophy of the myocardium insufficient to produce positive ECG criteria for left ventricular hypertrophy or right ventricular hypertrophy but sufficient to mimic infarction.

Adult↗
PubMed1996

Synthesis of substituted quinazolone derivatives as potential anti-HIV agents (Part III).

Several 1-[2-phenyl-4(4H)-oxo-3-quinazolinyl]-2-methyl-4-arylidine -5-oxo-imidazolines (Va-1), 2-phenyl-3-(aroyl amino)-4(4H)-oxo quinazolines (Vla-I) and N1-2-methyl-4(4H)-oxo-3-quinazolinyl-N2-aryl-thioureas (Vlla-k), have been synthesised and tested for anti-HIV activity. The structures of these compounds have been established on the basis of elemental analysis and spectral data.

Antiviral Agents↗
PubMed1996

Anti-HIV activity of some non-nucleoside s-triazine derivatives (Part-IV).

2-(4-Methoxy/2-methyl phenyl)-4-phenyl acetyl hydrazino-6-isonicotinyl hydrazino-s-triazines (1a-b) have been synthesized and tested for their anti-HIV activity against susceptible human host cell (CEM cell line), over a wide range of concentrations. The synthesized compounds have been found moderately active as compared to AZT.

Antiviral Agents↗
PubMed1995

Acute isoniazid neurotoxicity in an urban hospital.

OBJECTIVES: To describe the presentation and treatment of acute isoniazid (INH) neurotoxicity appearing at an inner-city municipal hospital. DESIGN: Case series. PARTICIPANTS: Seven patients (eight patient visits) with an age range of 5 days to 14.9 years. RESULTS: At our institution, no children appeared with acute INH neurotoxicity in the period 1985 through 1990, whereas seven patients were treated from 1991 through 1993. This paralleled the rise in the number of children with tuberculous infection and disease seen at our institution, from an average 96 per year to 213 per year during these two time periods. All seven patients were receiving INH daily for tuberculosis (TB) prophylaxis. Accidental ingestion (five episodes) and suicidal attempts (three episodes) accounted for these visits. The total amount ingested range from 14.3 to 99.3 mg/kg (mean, 54 mg/kg). All but one patient presented with afebrile seizures. One patient presented twice with seizures. Acute INH neurotoxicity was not suspected on the first admission; however, when readmitted 4 weeks later with another seizure, the diagnosis of acute INH neurotoxicity was made. INTERVENTION: Intravenous pyridoxine was used in five episodes. Because it was not a stocked item in our pediatric emergency cart (as well as at another hospital, necessitating a transfer of a patient with refractory seizures to our hospital), the average delay was 5.8 hours (range, 1.3 to 13 hours) before it was given. Two patients with refractory seizures failed to respond to anticonvulsants, and their seizures were controlled only after parenteral pyridoxine. CONCLUSIONS: We have seen an increased incidence of acute INH neurotoxicity because of the resurgence of TB in New York City. Others as well may see a similar rise based on local trends in TB infection and disease. Acute INH toxicity should be suspected in children presenting with seizures with or without fever. In patients with a known access to INH, seizures should be considered to be caused by INH toxicity unless proved otherwise. Parenteral pyridoxine, the specific antidote for INH-induced refractory seizures, should be readily available in every emergency department in the areas similarly experiencing increasing trends of TB.

Acute Disease↗
PubMed1994

Magnesium deficiency as a cause of hypocalcemia in the CHARGE association.

OBJECTIVE: To discover the mechanism of hypocalcemia in a patient with the CHARGE (coloboma, heart disease, atresia choanae, retarded growth and development, genital hypoplasia, and ear anomalies) association. RESEARCH DESIGN: Chemical and metabolic studies of serum, urine, stool, and muscle specimens. SETTING: A university hospital affiliated with a municipal hospital. PARTICIPANT: One patient with the CHARGE association and refractory hypocalcemia. MEASUREMENTS AND RESULTS: Serum calcium level was 0.91 mmol/L (reference range, 2.20 to 2.58 mmol/L) and serum magnesium level was 0.34 mmol/L (reference range, 0.80 to 1.20 mmol/L) prior to any therapy. After parenteral calcium and magnesium therapy, hypocalcemia persisted (1.46 mmol/L), while the serum magnesium level was 0.84 mmol/L. A needle biopsy of skeletal muscle tissue for the magnesium content confirmed a total magnesium deficiency despite normomagnesemia (muscle magnesium content, 517 micrograms/g [reference range, 800 to 1100 micrograms/g]). Magnesium deficiency was secondary to secretion of magnesium into the gastrointestinal tract (with a daily magnesium intake of 190 mg, a 24-hour nondiarrheal fecal excretion of magnesium was 2019 mg/kg [reference range, < 1000 mg/kg of stool weight]). INTERVENTIONS: Hypocalcemia was corrected only after 7 weeks of continual parenteral magnesium supplements to replenish the tissue magnesium deficiency. CONCLUSIONS: Patients with the CHARGE association often have hypocalcemia. Magnesium deficiency (with or without hypomagnesemia) is a cause of the hypocalcemia in at least one patient and may prove of significance in others.

Abnormalities, Multiple↗
PubMed1994

Single-day therapy for nutritional vitamin D-deficiency rickets: a preferred method.

A single-day large dose of vitamin D (stosstherapy) was given to 42 patients with nutritional vitamin D-deficiency rickets. Stosstherapy is safe and effective, obviates problems with compliance, and, by evoking a response in 4 to 7 days in nutritional rickets, becomes a valuable diagnostic aid for patients in whom initial findings do not clearly distinguish nutritional rickets from familial hypophosphatemic rickets.

Administration, Oral↗
PubMed1992

Spinal cord injury produced by consistent mechanical displacement of the cord in rats: behavioral and histologic analysis.

We examined the ability of an electromechanical device to produce consistent and incomplete thoracic (T9) spinal cord injuries in rats by brief displacement (Dspl) of the exposed dural surface. Open field walking, inclined plane, grid walking, and footprint analysis, and a determination of the percentage of tissue spared at the lesion center were used to assess chronic outcome (6 weeks postinjury). Laminectomy control animals showed no evidence of a functional deficit or histologic lesion. Complete spinal cord transections in normal rats and in a group of animals previously injured (1.1 mm Dspl) and allowed to recover resulted in complete loss of hindlimb function, demonstrating an important functional role for the remaining spared fibers at the lesion site. Consistent spinal cord displacements (0.80 mm, 0.95 mm, and 1.10 mm) resulted in behavioral groups with low outcome variability over a narrow range of incomplete recovery of neurologic function. Significant behavioral (open field walking, inclined plane, and grid walking) and histologic differences were found between the control and Dspl groups and between the 0.80 mm and 1.10 mm Dspl groups. Significant correlations were observed among the injury parameters, behavioral, and histologic scores. Open field walking and inclined plane performance were sensitive indicators of both the early and late phases of neurologic recovery. Grid walking was most useful in animals with small chronic residual deficits. The footprint analysis resulted in less significant correlations and differences between the behavioral groups than the other outcome measures. This may result from a relatively narrow range of sensitivity (open field walking scores between 3.3 and 4.0) and increased variability within the groups.

Animals↗
PubMed1989

Centbutindole vs trifluoperazine: a double-blind controlled clinical study in acute schizophrenia.

Twenty-nine acute schizophrenic patients were treated under double-blind conditions for six weeks with either centbutindole in a dose range of 3 mg/day to 4.5 mg/day or trifluoperazine in the dose range of 15 mg/day to 22.5 mg/day. Both drugs produced a significant improvement in initial psychopathology. No significant differences were demonstrated between the two treatment conditions.

Adult↗
PubMed1988

Familial glucocorticoid deficiency in a girl with familial hypophosphatemic rickets.

Familial glucocorticoid deficiency is a rare multisystem disorder characterized by glucocorticoid deficiency with normal mineralocorticoid activity, achalasia of the cardia, and alacrima. Familial hypophosphatemic rickets is characterized by selective renal phosphate wasting with subsequent hypophosphatemia and an inappropriately low 1,25-dihydroxyvitamin D concentration for the degree of hypophosphatemia. A 6-year-old girl with both disorders is described. A biochemical relationship between familial glucocorticoid deficiency and familial hypophosphatemic rickets could not be defined; the influence of cortisol on her serum calcium level, phosphorus level, and rickets, as well as the natural history of these two entities, is described.

Child↗