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Biomedical subjects

U Jain

Publications and source records attributed to U Jain.

At least 37 records · Page 2Linked to original sources
PubMed1995

Myocardial injury during reoperation for coronary artery bypass surgery.

OBJECTIVES: To determine the incidence, triggers, and timing of myocardial injury during reoperation for coronary artery bypass surgery. DESIGN: Prospective observational. SETTING: One tertiary care university hospital. PARTICIPANTS: 15 patients undergoing reoperation. INTERVENTIONS: Multilead electrocardiographic monitoring approximately every 3 minutes during surgery. MEASUREMENTS AND MAIN RESULTS: The occurrence of a new ischemic ST elevation or depression on the electrocardiogram (ECG) was determined. A major deterioration in ventricular function after cardiopulmonary bypass (CPB) also was determined. Peak creatine kinase myocardial band (CK-MB) > or = 25 IU/L was considered to be the marker of myocardial injury. Seven patients demonstrated myocardial injury, all intraoperatively. Five of these patients had new ST elevation episodes before CPB. Three of the episodes were temporally associated with an abrupt increase in the heart rate. The other two episodes were temporally associated with surgical manipulation of the heart and the old grafts. The sixth patient had a significant deterioration of ventricular function during CPB. One of the patients who had ST elevation before CPB and the seventh patient developed ST elevation towards the end of protamine administration. CONCLUSIONS: In patients undergoing reoperation, the intraoperative incidence of myocardial injury, especially before CPB, was found to be substantially higher than that previously reported.

Aged↗
PubMed1995

Effects of perioperative dexmedetomidine infusion in patients undergoing vascular surgery. The Study of Perioperative Ischemia Research Group.

BACKGROUND: Dexmedetomidine, a highly selective alpha 2-adrenergic agonist, increases perioperative hemodynamic stability in healthy patients but decreases blood pressure and heart rate. The goal of this study was to evaluate, in a preliminary manner, the hemodynamic effects of perioperatively administered dexmedetomidine in surgical patients at high risk for coronary artery disease. METHODS: Twenty-four vascular surgery patients received a continuous infusion of placebo or one of three doses of dexmedetomidine, targeting plasma concentrations of 0.15 ng/ml (low dose), 0.30 ng/ml (medium dose), or 0.45 ng/ml (high dose) from 1 h before induction of anesthesia until 48 h postoperatively. All patients received standardized anesthesia and hemodynamic management. Blood pressure, heart rate, and Holter ECG were monitored; additional monitoring included continuous 12-lead ECG preoperatively, anesthetic concentrations and myocardial wall motion (echocardiography) intraoperatively, and cardiac enzymes postoperatively. RESULTS: Preoperatively, there was a decrease in heart rate (low dose 11%, medium dose 5%, high dose 20%) and systolic blood pressure (low dose 3%, medium dose 12%, high dose 20%) in patients receiving dexmedetomidine. Intraoperatively, dexmedetomidine groups required more vasoactive medications to maintain hemodynamics within predetermined limits. Postoperatively, demedetomidine groups had less tachycardia (minutes/monitored hours) than the placebo group (placebo 23 min/h; low dose 9 min/h, P = 0.006; medium dose 0.5 min/h, P = 0.004; high dose 2.3 min/h, P = 0.004). Bradycardia was rare in all groups. There were no myocardial infarctions or discernible trends in the laboratory results. CONCLUSIONS: Infusion of dexmedetomidine up to a targeted plasma concentration of 0.45 ng/ml appears to benefit perioperative hemodynamic management of surgical patients undergoing vascular surgery but required greater intraoperative pharmacologic intervention to support blood pressure and heart rate.

Blood Pressure↗
PubMed1995

Myocardial ischemia after cardiopulmonary bypass.

Intraoperatively, myocardial ischemia is more common after cardiopulmonary bypass (CPB) than before CPB. Ischemia associated with coronary vasospasm and thrombosis may be much more common toward the end of surgery and early in the postoperative period than previously appreciated. This may be because the coagulation system is altered during CPB, and the coronary endothelium is damaged significantly as a result of cardioplegic arrest followed by reperfusion. In this milieu, vasospasm and thrombosis may be caused by the administration of protamine. Some of the ischemia observed in this period actually is not reversible and is associated with myocardial injury and infarction. It may be ameliorated by the administration of calcium channel blockers, aspirin, and anticoagulants. Electrocardiography may be the most suitable modality for the detection of ischemia after CPB and postoperatively. During this period, many episodes of ST deviation are of a nonischemic etiology, and the ECG needs careful interpretation. Transesophageal echocardiography is suitable for use intraoperatively and early on in the intensive care unit.

Cardiopulmonary Bypass↗
PubMed1995

A clinical and cytogenetic study of Turner syndrome.

Forty five case of Turner syndrome diagnosed in the Genetics Clinic, between January 1986 and December 1993, were analyzed. The most commonly observed karyotype was 45, X (44.4%), followed by 45, X/46, XX mosaicism (24.4%). Less frequently demonstrated karyotypes were 45, X/46, X, i (Xq) mosaicism and 46, X, i (Xq) (13.3%). Mosaicism for chromosome was seen in 6.7% of patients. Patients with 45, X karyotype had short stature (85%), dysmorphic facies (60%), delayed appearance of secondary sexual characters (100%) and primary amennorhea (100%). Those with 45, X/46, XX mosaicism were less often dysmorphic and presented with either primary or secondary amenorrhea. Patients with 45, X karyotype were younger at diagnosis and had a significantly shorter mean adult height than those with 45, X/46, XX mosaicism. The phenotype in patients with other karyotypic abnormalities was similar to the 45, X group. Short stature and primary or secondary amenorrhea occurring together in a female strongly suggests the possibility of Turner syndrome, which should be confirmed by chromosomal analysis.

Adolescent↗
PubMed1994

Poland anomaly with unusual associated anomalies: case report of an apparent disorganized defect.

We report on a 2 1/2-year-old boy with absence of clavicular head of pectoralis major on the left side, ipsilateral upper limb anomalies, and anomalies of the lower limbs such as popliteal webbing, median cleft of right foot, bifid left hallux, syndactyly of toes, and toenail hypoplasia. Other anomalies included undescended testis, hairy nevus in the lumbosacral region, and a pedunculated finger-like tag on the right thigh. The pathogenesis of these associated anomalies cannot be explained on the basis of compromised local blood supply alone. A possible link with the disorganization mutation is discussed.

Abnormalities, Multiple↗
PubMed1994

Cellular immunity in depressed, conduct disorder, and normal adolescents: role of adverse life events.

OBJECTIVE: To determine whether adolescents with major depressive disorder have disturbances in their cellular immunity and to study whether the immunological changes detected are specific to depression or are general responses to stress. METHOD: Twenty subjects with major depressive disorder, 17 nondepressed subjects with conduct disorder, and 17 normal adolescents were recruited. Subjects were assessed with a clinical interview for DSM-III-R and a modified version of the Coddington Life Events Checklist. Blood samples were drawn for total white blood cells, lymphocytes subsets, natural killer cell activity, lymphocyte proliferation response to phytohemagglutinin, and cortisol plasma levels. RESULTS: Overall, there were no significant between-group differences in any of the cellular immune measurements. Natural killer cell activity was significantly negatively correlated with past year and lifetime adverse life events across all effector-target cell ratios. Controlling for diagnoses and socioeconomic status yielded similar results. There were no significant effects of age, sex, race, sleep, nutrition, cigarette use, menstrual cycle, or cortisol on any of the immunological variables. CONCLUSIONS: In this sample of adolescents, we found that independent of the diagnoses and socioeconomic status, increases in adverse life events were associated with low natural killer cell activity.

Adolescent↗
PubMed1994

Electrocardiographic determination of perioperative myocardial ischemia and stunning.

Many modalities are available for monitoring for ischemia. Electrocardiography (ECG) is the most suitable modality for monitoring for perioperative ischemia. The detection and monitoring of myocardial stunning is more difficult. T wave inversion or peaking may be caused by ischemia. However, numerous nonischemic causes may lead to perioperative T wave changes. Inverted T waves may also indicate myocardial stunning. ST deviation is the most commonly used feature of ischemia. ST depression may be indicative of subendocardial ischemia while ST elevation may be associated with transmural ischemia or injury. Perioperatively, ST deviation may be caused by many nonischemic causes. Fixed ST deviation may be caused by left ventricular hypertrophy (LVH), cardiac conduction changes, old MI, coronary artery disease, and other causes such as drugs, including digitalis. New ST deviation may be caused by changes in body position. During cardiopulmonary bypass, ST deviation may be caused by hypothermia and defibrillation. ST deviation may be caused by new cardiac conduction changes and pericarditis. Ischemia may cause changes in other features of the ECG including the R wave, Q wave, U wave, QRS axis, and the angle between QRS axis and T wave axis. However, the specificity of these features for ischemia is even lower than that of the ST segment.

Cardiac Surgical Procedures↗
PubMed1994

Significance of electrocardiographic ST elevation during coronary artery bypass surgery.

The aim of this study was to determine the significance of new electrocardiographic (ECG) ST elevation during coronary artery bypass surgery. Multilead ECGs were recorded intraoperatively approximately every 3 min on 105 patients. Cases of new ST elevation were divided into ischemic and those considered to be due to nonischemic causes such as cooling during cardiopulmonary bypass (CPB), defibrillation, new cardiac conduction abnormalities, and pericarditis. The myocardial fraction of creatine kinase (CK-MB) > or = 25 IU/L was considered to be indicative of myocardial injury. Both patients who had ischemic ST elevation prior to CPB and all seven patients who had ST elevation in temporal association with the administration of protamine had peak CK-MB > or = 25 IU/L. One patient with peak CK-MB > or = 25 IU/L did not have ST elevation and was considered to have injury during CPB. Two of these ten patients had Q wave myocardial infarctions (MIs). For the detection of patients with peak CK-MB > or = 25 IU/L, the sensitivity of ischemic ST elevation was 90% and the specificity was 100%. A history of MI prior to surgery and a history of Type I diabetes were associated with peak CK-MB > or = 25 IU/L (P < 0.05).

Aged↗
PubMed1993

Can myocardial stunning contribute to myocardial infarction during coronary artery bypass surgery?

Myocardial stunning commonly occurs after cardiopulmonary bypass (CPB). Myocardial stunning can be cardioprotective under some conditions, but in other situations may actually contribute to myocardial infarction (MI). Vascular endothelial stunning may be one of the mechanisms by which myocardial stunning can cause MI. It has been found that 15 minutes of reversible ischemia is enough to cause elevations in vascular resistance and impairment of vasodilator responsiveness. However, no correlation between contractile dysfunction and microvascular stunning has been observed. Transduction defects (increased oxygen extraction and consumption despite normal regional oxygen blood flow and delivery) may be another mechanism by which stunning predisposes to MI, indicating uncoupling of substrate utilization from energy production. In addition, abnormalities in wall motion, oxygen free radical toxicity, hypotension, use of inotropic agents (leading to increased oxygen consumption, high heart rates, and arrhythmias) increase the risk of cellular necrosis. Following CPB, flow limitations due to diffuse atherosclerosis in some areas may result in poor contractility, and newly grafted areas have a high probability of becoming ischemic and stunned. These areas are likely to contribute to MI.

Cardiomyopathies↗
PubMed1991

Radiographic pulmonary abnormalities after different types of cardiac surgery.

One aim of this study was to determine the incidence of new radiographic pulmonary abnormalities during hospitalization after cardiac surgery. Another aim was to determine if such abnormalities are more common among patients who had left internal mammary artery (LIMA) grafting. The predictive value of radiographic abnormalities for clinically important pulmonary morbidity was also determined. The anteroposterior chest radiographs of 152 patients obtained by portable equipment were evaluated to determine the incidence of new postoperative radiographic pulmonary abnormalities such as atelectasis, consolidation, infiltrate, and pleural effusion. Clinically important pulmonary morbidity was defined as a delay in tracheal extubation or discharge from the hospital because of a pulmonary reason. Among the 89 patients who had LIMA grafting and left pleurotomy, there was an 88% incidence of left-sided pulmonary abnormalities; a 73% incidence of left-sided atelectasis; and a 55% incidence of left-sided effusion. Among the 63 patients who had saphenous vein grafting only and/or valvular surgery, the respective incidences were 68%, 54%, and 35%, which were lower (P less than or equal to 0.05) than those in the patients who had LIMA grafting. There was no significant difference in abnormalities between the saphenous vein grafting and the valvular surgery groups. The 35% incidence of left-sided pleural effusion when LIMA grafting and pleurotomy were not performed was unexpectedly high. There was no association between radiographic abnormalities and age, the duration of cardiopulmonary bypass, and the duration of aortic occlusion, indicating that cardiopulmonary bypass was not a primary etiology of these radiographic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Effects of prolonged deprivation on learned helplessness.

The influence of prolonged deprivation on response to uncontrollable outcome was investigated among 104 young Indian students. They received an unsolvable block design task followed by an anagram solution test and an attribution questionnaire. As predicted, the high-deprived and the female students displayed greater helplessness than their low-deprived and male counterparts, and they attributed uncontrollable outcome more to internal, stable, and global causes.

Adolescent↗
PubMed1990

Electrocardiographic J waves after resuscitation from cardiac arrest.

A patient was monitored prior to, during, and after cardiac arrest with a Holter monitor and an electrocardiograph. The arrest occurred without any premonitory signs on the ECG. At the onset of the arrest, torsades de pointes ventricular tachycardia occurred, which quickly degenerated into ventricular fibrillation. After a successful second defibrillation, the patient developed Osborn waves, which subsided within a few minutes.

Coronary Artery Bypass↗
PubMed1990

Purification and characterization of E. histolytica antigen for diagnosis of amoebiasis.

Entamoeba histolytica soluble crude antigen was fractionated by gel filtration on Sephacryl S-300 into four fractions, viz. F1(669 kDa); F2(51.2 kDa); F3(25.1 kDa) and F4(10.5 kDa). F1 fraction was observed to be more sensitive and specific for the detection of antibody in amoebiasis than the crude and other fractions of purified antigens employing IHAT and ELISA. ELISA was found to be better than IHAT since it could detect antibody in the sera (3/6) of asymptomatic cyst passers. The cross reaction of crude antigen with toxocariasis (1/4) and toxoplasmosis (2/5) sera were associated with F4 fraction. F3 and F4 were having low molecular weight and were not sensitive in detection of antibody in amoebiasis. Biochemical characterization revealed glycoprotein nature of the specific (F1) antigen fraction.

Animals↗