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Biomedical subjects

D Jain

Publications and source records attributed to D Jain.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Bloom syndrome in sibs: first reports of hepatocellular carcinoma and Wilms tumor with documented anaplasia and nephrogenic rests.

The triad of small body size, immunodeficiency, and sun-sensitive facial erythema characterizes the phenotype Bloom syndrome (BS), a rare autosomal recessive disorder with a striking predisposition to multiple types of cancers that arise earlier than expected in the general population. Here we report two sibs with BS. The older, a 15-year-old-girl, developed a hepatocellular carcinoma, a neoplasm not yet reported in association with BS. Her younger brother developed an anaplastic Wilms tumor (WT) associated with nephrogenic rests at the age of 31/2 years, and this was followed by a myelodysplastic syndrome. Complex cytogenetic abnormalities were identified in all three neoplasms. These examples expand the spectrum of malignancies occurring in BS to include liver cell neoplasms, and confirm the association of nephrogenic rests with WT, even in the setting of BS.

Adolescent↗
PubMedDate not supplied

Relationship of scar and ischemia to the results of programmed electrophysiological stimulation in patients with coronary artery disease.

BACKGROUND: Although myocardial perfusion imaging (MPI) is widely used in patients with coronary artery disease, few data are available concerning the relationship between myocardial scar and ischemia and arrhythmic potential. PATIENTS AND METHODS: One hundred forty-four patients with chronic coronary artery disease who underwent electrophysiological studies (EPS) and MPI within 3 months constituted the study population. By history, 26% of the patients had sustained ventricular tachycardia (VT), 21% had cardiac arrest with ventricular fibrillation, and 53% had nonsustained VT. Eighty-five percent had previous myocardial infarction. Standard EPS protocol with up to three extra stimuli was used. Patients with a response of sustained monomorphic VT were defined as inducible. Quantitative MPI was used to define stress perfusion defect size and reversibility. The relations of ischemia (reversible defect) and scar (fixed defect) to inducibility on EPS were assessed by univariate analysis. Multivariate analysis was used to compare MPI results with known clinical predictors of inducibility. RESULTS: Fifty-two percent of the patients had inducible monomorphic sustained VT. MPI showed scar alone in 33%, scar with additional ischemia in 53%, ischemia alone in 8%, and no abnormality in 6%. No relation was found between the scintigraphic presence or size of ischemia and the likelihood of inducibility or to the type of arrhythmia history. In contrast, scar size was related to the result of EPS; inducible patients had significantly larger resting defect integrals (27 +/- 23 vs 14 +/- 15) than noninducible patients (p < 0.0001). Of 37 patients with very large defects (defect integral > 30), 78% were inducible, whereas only 30% of 33 patients with defect integrals < 5 were inducible. On multivariate analysis resting defect integral was an independent predictor of inducibility. In comparison with left ventricular ejection fraction (available in 122 patients), perfusion defect size was a better independent predictor of sustained VT on EPS. CONCLUSION: The presence or size of potentially ischemic myocardium does not appear to be related to the inducibility during EPS. Size of scar as quantified by myocardial perfusion imaging correlates well and better than the global left ventricular function with inducibility of sustained VT on EPS.

Cardiac Pacing, Artificial↗
PubMedDate not supplied

Day-to-day reproducibility of mental stress-induced abnormal left ventricular function response in patients with coronary artery disease and its relationship to autonomic activation.

BACKGROUND: Mental stress (MS) results in left ventricular (LV) dysfunction in approximately half of the patients with symptomatic coronary artery disease (CAD) and is an adverse prognostic sign. The reproducibility of various MS tasks in inducing LV dysfunction and its relationship to autonomic activation in patients with CAD are not known. We studied the reproducibility on different days of 3 commonly used MS tasks on LV ejection fraction (LVEF), heart rate, blood pressure, and rate-pressure product and the relationship of reproducibility to autonomic activation as determined by heart rate variability in patients with chronic stable angina. METHODS AND RESULTS: Ten patients with CAD and exercise-induced ischemia who had abnormal LVEF responses to at least one MS task from a battery of MS tasks (mental arithmetic, anger recall, and color Stroop test) while undergoing continuous ambulatory Holter and LV function monitoring underwent a second MS testing 4 to 8 weeks later, with no change in clinical status or cardiac medications in the interim. Autonomic tone was determined from indexes of heart rate variability (high frequency [HF] for parasympathetic activity and low frequency [LF] and low frequency/high frequency ratio [LF/HF] for sympathetic activity). MS tasks resulted in a small increase in heart rate (P <.0001), a modest increase in systolic blood pressure (P <.0001) and the rate-pressure product (P <.0001), and a small but statistically significant increase in LF (P <.002) and LF/HF (P <.0001), but no change in HF compared with baseline. These changes were highly reproducible over the 2 studies. With a fall in LVEF of 5% or greater considered as indicative of an MS-positive task, anger recall was the most effective and reproducible MS task in inducing LV dysfunction. MS-positive tasks were associated with a greater increase in systolic blood pressure (P =.005). Anger recall resulted in a trend toward a higher increase in systolic blood pressure (P =.08) than the other MS tasks. In MS tasks with inconsistent LVEF responses in the 2 studies (LV dysfunction present in one study but not in the other), there was significant parasympathetic withdrawal (P =.02) in MS-negative tasks but no difference in sympathetic activation. On the other hand, in MS tasks with consistent LV dysfunction on both occasions, there was no difference in parasympathetic or sympathetic activation. MS-positive tasks were not accompanied by chest pain or ST depression. CONCLUSIONS: Of the commonly used MS tasks, anger recall produces LV dysfunction with the highest frequency and is the most reproducible task when retested 4 to 8 weeks later in patients with CAD. These data are relevant for planning studies of the effects of therapeutic interventions on MS-induced LV dysfunction.

Aged↗
PubMedDate not supplied

Decreased sodium-potassium and calcium adenosine triphosphatase activity in asthma: modulation by inhaled and oral corticosteroids.

The activation of both the inflammation-producing cells and the airway smooth muscle in asthma is believed to be a phenomenon dependent on the intracellular calcium. The activity of Na+ K+ ATPase and Ca2+ ATPase, enzymes responsible for regulating the intracellular calcium concentrations has been reported to be decreased in asthma. An increase in plasma lysophosphatidylcholine (LPC), which is known to be a pro-inflammatory compound and has an inhibitory effect on the two ATPases has also been reported. Corticosteroids are potent antiinflammatory drugs very effective in the treatment of asthma. The effect of long-term (12 weeks) treatment with inhaled beclomethasone dipropionate (BDP) and short-term (1 week) treatment with oral prednisolone on the activity of the two ATPases and intracellular calcium in leukocytes and plasma LPC levels was investigated. Both the treatments resulted in an improvement in lung function accompanied by an increase in the activities of the ATPases and a decrease in the intracellular calcium and LPC levels. It was concluded that increase in the activities of Na+ K+ ATPase and Ca2+ ATPase and a consequent lowering of intracellular calcium, and a lowering of plasma LPC may underlie the beneficial effect of corticosteroids in asthma.

Adolescent↗
PubMedDate not supplied

Long-term stability of bronchial reactivity in guinea pigs.

Measurement of lung function and bronchial reactivity are widely used as outcome parameters to assess the efficacy of therapeutic interventions. In order to interpret the results correctly, it is necessary that the outcome parameters are themselves stable over time so that any significant changes measured may be attributed to the interventions. Specific airway conductance (SGaw) and airway reactivity to histamine are two commonly used parameters in animal models such as guinea pigs. Although short-term variability of these parameters has been investigated, there has been no study of long-term stability. In the present paper, SGaw and bronchial reactivity to histamine were measured in 111 conscious guinea pigs using a non-invasive, whole body plethysmograph. Baseline values of SGaw and ED35 histamine were measured and followed for eight weeks at weekly intervals. At baseline, mean SGaw in guinea pigs was 0.17 +/- 0.055 sec-1 cm H2O-1 and ED35 histamine ranged from 0.064 to more than 10 mg/ml. The distribution of ED35 histamine values was gaussian. We observed that the changes in SGaw and ED35 histamine recorded using this technique are highly reproducible over eight weeks. The reactivity varied by less than a doubling dose of histamine over any two consecutive weeks. Thus, the technique described in this paper is quick, easily learned, reproducible, independent of temperature-humidity artifact and highly suitable for studies of repeated measurements as in the study of dietary interventions and evaluation of effect of drugs.

Airway Resistance↗
PubMedDate not supplied

Neurohumoral activation in percutaneous coronary interventions: apropos of ten vasoactive substances during and immediately following coronary rotastenting.

BACKGROUND: Ischemia, left ventricular dysfunction, endothelial damage and hemodynamic changes during percutaneous coronary intervention can lead to neurohumoral activation. This may partly explain the frequent episodes of coronary spasm, hypotension and bradycardia which occur during the procedure. Rotastenting, by employing the two basic mechanisms for coronary interventions-debulking and dilatation-epitomizes percutaneous coronary interventions in general. We sought to investigate the neurohumoral changes during and immediately following coronary rotastenting. METHODS AND RESULTS: Eighteen patients undergoing elective rotablator atherectomy followed by balloon predilatation and stenting for chronic stable angina were studied. Four femoral vein blood samples were drawn from each patient at the start of the intervention (baseline), and 2 (postdebulking-2), 10 (postdebulking-10) and 60 (postdebulking-60) minutes. respectively, after the first complete passage of the rotablation burr across the whole length of lesion. Levels of 10 neurohormones, namely, endothelin-1, bradykinin, arginine vasopressin, norepinephrine, dopamine, epinephrine, angiotensin II, serum angiotensin-converting enzyme activity. atrial natriuretic peptide and kininogen were estimated in each sample. Endothelin-1 and bradykinin attained their peak levels in the postdebulking-2 samples. and the rise from 0.34+/-0.07 pmol/ml and 235.8+/-17.7 pg/ml to 0.42+/-0.06 pmol/ml and 337.2+/-41.0 pg/ml, respectively, was statistically significant (p<0.05). The level of arginine vasopressin showed a significant (p<0.05) rise from baseline (108.5+/-31.8 pg/ml) to postdebulking-60 samples (136.5+/-39.4 pg/ml). The other neurohormones did not show significant changes. CONCLUSIONS: The results suggest a definite but differential neurohumoral activation during and immediately following rotastenting. These neurohumoral changes may have a role in untoward intra- and postprocedural vasomotor and hemodynamic effects. This study establishes the concept of neurohumoral activation during percutaneous coronary interventions.

Aged↗