Search PubMed⌕ Search

Biomedical subjects

L Aronson

Publications and source records attributed to L Aronson.

31 records · Page 2Linked to original sources
PubMed1989

Thrombolysis and Angioplasty in Myocardial Infarction (TAMI-1) trial: influence of infarct location on arterial patency, left ventricular function and mortality.

The influence of infarct location on arterial patency, left ventricular function and mortality after 150 mg of intravenous recombinant tissue-type plasminogen activator (rt-PA) and selective coronary angioplasty was studied in 386 patients with acute myocardial infarction. In 329 patients with acute and 1 week angiograms, the 90 min infarct-related artery patency rate after rt-PA in the left anterior descending, the left circumflex and the right coronary artery was 77, 68 and 68%, respectively. Angioplasty, performed in half the patients, resulted in a final acute patency rate of 93%, which was not related to arterial distribution. Repeat catheterization and revascularization were required in 12% of patients before day 7 and were independent of arterial distribution. The reocclusion rate for the right coronary artery (21%) was higher than that for the left anterior descending (12%) or left circumflex (5%) artery (p = 0.01). Acute and 1 week contrast ventriculograms suitable for analysis were available in 266 patients. Whereas serial left ventricular ejection fraction did not improve during the course of this study, serial regional wall motion (centerline chord method) improved in each arterial distribution. The in-hospital mortality rate of 6% was not related to arterial distribution, although death was twice as likely with proximal compared with distal lesions. Ten of 11 patients who died in the group with the left anterior descending artery as the infarct-related artery had a lesion proximal to the first septal perforator branch.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Extracochlear electrical stimulation.

Twelve patients with sensorineural hearing loss were stimulated by a transtympanic electrode contacting the cochlear promontory. Nine of them were tested to study hearing perception associated with various features of electrical signals, using an auditory electrical stimulator. Biphasic pulse bursts and sine-wave bursts were used as stimuli. Different electrical characteristics such as amplitude, width and rate for pulses and amplitude and frequency for sine waves were used to investigate hearing perception. The patients' perception threshold, comfortable level, uncomfortable level, dynamic range, just-noticeable difference in frequency or pitch discrimination, just-noticeable difference in intensity or loudness discrimination, loudness perception associated with the electrical signal energy, and sounds associated with electrical stimulation was determined. Pertinent results assisted in the development of a speech electrical stimulator that was used to test three patients for vowel, word, and consonant identification and recognition of patterns of intonation. These results in turn are being used to design a prototype of a single-channel extracochlear prosthesis.

Acoustic Stimulation↗
PubMed1989

A randomized controlled trial of intravenous tissue plasminogen activator and early intravenous heparin in acute myocardial infarction.

To evaluate the coronary thrombolytic efficacy of tissue plasminogen activator (t-PA) and early intravenous heparin, 134 patients with acute myocardial infarction were randomly assigned to combination therapy or t-PA only. At a median of 2.78 hours from symptom onset, 64 patients received both t-PA (1.5 mg/kg/4 hr) and a bolus of 10,000 units heparin, whereas 70 patients received t-PA alone at the same dose. All patients underwent coronary angiography 90 minutes after initiation of therapy to determine infarct vessel patency status, after which time the control group patients were eligible to receive heparin. Baseline demographic and angiographic characteristics were similar for the groups. Infarct vessel patency was 50 of 63 (79%) for combination t-PA and heparin and 54 of 68 (79%) for t-PA alone. Bleeding complications, as reflected by need for transfusion, were similar in the two groups: 13% in the patients treated with t-PA and heparin compared with 18% in patients treated with t-PA only (p = 0.53). The only intracranial hemorrhage in the trial occurred in a patient initially treated without heparin. Fibrinogen at 50 minutes after therapy was 32% decreased from baseline for the t-PA and heparin-treated patients compared with a 39% decrease in the control group. Predischarge left ventricular ejection fraction was similar for the two groups: 49.0 +/- 10.1% versus 50.2 +/- 11.9% for combined versus t-PA only therapy, respectively. We conclude that early intravenous heparin does not facilitate the fibrinolytic effect of t-PA at the doses tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1988

Failure of simple clinical measurements to predict perfusion status after intravenous thrombolysis.

To determine whether coronary patency could be detected early during thrombolytic therapy, commonly used markers of perfusion were recorded in 386 patients with acute myocardial infarction treated with tissue plasminogen activator. Infarct artery angiography 90 minutes after initiation of therapy was used to determine perfusion status. Of patients with complete resolution of ST segment elevation before the angiogram, 96% (95% confidence interval, 79% to 100%) showed perfusion on the angiogram, and among those with partial improvement, 84% (95% confidence interval, 76% to 90%) showed perfusion, but these findings occurred in only 6% and 38% of patients respectively. When complete resolution of chest pain occurred before the angiogram, 84% of patients (95% confidence interval, 75% to 90%) showed perfusion, but this finding occurred in only 29% of patients. Although arrhythmias occurred frequently in the first 90 minutes of therapy, none were associated with a higher patency rate. No other factors predicted coronary patency. A logistic regression model showed 25% of patients with 90% or greater probability of patency, but 56% of patients with no ST segment or symptom resolution had patent arteries.

Angina Pectoris↗
PubMed1985

Prolonged cardiac arrest and resuscitation in dogs: brain mitochondrial function with different artificial perfusion methods.

Clinical techniques for artificial perfusion have not previously been examined directly for their effects on brain high-energy metabolism. Our study involved 24 large mongrel dogs that were anesthetized, instrumented for central venous intravenous access, and subjected to craniotomy to expose the dura and underlying parietal cortex. The animals were divided into the following six experimental groups of four animals each: nonischemic controls; 15-minute cardiac arrest without resuscitation; 45-minute cardiac arrest without resuscitation; 15-minute cardiac arrest plus 30 minutes resuscitation with conventional cardiopulmonary resuscitation (CPR); 15-minute cardiac arrest plus 30 minutes resuscitation with interposed abdominal compression (IAC) CPR; and 15-minute cardiac arrest plus 30 minutes resuscitation with internal cardiac massage. Cardiac arrest was induced by central venous injection of KCl 0.6 mEq/kg, and it was confirmed by continuous ECG monitoring. The three active resuscitation models included administration of NaHCO3 and epinephrine, but no attempt was made to restart the heart by defibrillation during resuscitation. At the indicated time in each group, a 4- to 5-g sample of brain was removed through the craniotomy, immediately cooled to 0 C and processed for isolation of mitochondria. The mitochondria were studied for their content of superoxide dismutase and for quantitative oxygen consumption with glutamate/malate substrate during resting and ADP-stimulated respiration. Our results show a significant drop in brain mitochondrial superoxide dismutase activity during the first 15 minutes of cardiac arrest. There is minimal injury to brain mitochondrial oxygen consumption during both 15 and 45 minutes of complete ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1980

Bioequivalence of subcutaneous calcium and sodium heparins.

The bioequivalence of subcutaneous porcine calcium and sodium heparins was studied in 48 normal male subjects randomly assigned to 1 of 4 study groups. Each subject received a single subcutaneous injection of 15,000 U of calcium heparin or 1 of 3 sodium heparins. Serial coagulation studies (Lee-White clotting time, activated partial thromboplastin time, thrombin calcium clotting time, and heparin level) were performed over 10 hr. There were no significant differences in anticoagulant effect between groups.

Adolescent↗
PubMed1978

The Passovoy defect: further characterization of a hereditary hemorrhagic diathesis.

We studied a coagulation abnormality present in 12 members of five kindreds who bruised easily and bled excessively after minor trauma. Their activated partial thromboplastin times were between 32 and 39 seconds (normal, 22.8 to 28.8 seconds). Prothrombin times, thrombin times, platelet-function tests and the levels of factors XII, XI, IX, VIII, prekallikrein and high-molecular-weight kininogen were normal. Within these kindreds inheritance of prolonged partial thromboplastin times followed an autosomal and probably dominant pattern. The prolonged thromboplastin times were corrected by normal plasma and by normal plasma adsorbed with celite, but there was no mutual correction between plasmas of the patients. These subjects shared a common defect in the intrinsic pathway of coagulation that we designate by the proband's surname, Passovoy.

Adolescent↗
PubMed1975

Passovoy factor: A hitherto unrecognised factor necessary for haemostasis.

A moderate bleeding diathesis transmitted as an autosomal dominant was found in five members of four generations of the same family. The affected patients had prolonged partial thromboplastin-times and normal levels of all the known clotting-factors. The haemorrhagic diathesis was attributed to a deficiency of a hitherto unrecognised coagulation factor--i.e., the Passovoy facto.

Adult↗
PubMedDate not supplied

Caudal vena cava obstruction and ascites in a cat treated by balloon dilation and endovascular stent placement.

OBJECTIVE: To present details of an unusual case of caudal vena caval obstruction and its management in a cat. STUDY DESIGN: Clinical case report. STUDY POPULATION: A 15 month old male castrated domestic shorthaired cat. RESULTS: The diagnostic evaluation included the use of digital subtraction angiography and ultrasonography to locate the caudal vena caval obstruction. Treatment initially involved puncture and balloon dilation of the obstructed area of the cava. After reobstruction, the stenotic area was redilated and stented. The cat was euthanatized 4 weeks later because of vomiting, anorexia, and abnormal behavior, presumed to be associated with liver disease. CONCLUSION AND CLINICAL RELEVANCE: Interventional radiography provided a minimally invasive way to manage this unusual vascular anomaly.

Angiography↗
PubMedDate not supplied

Multichannel cochlear implant in a deaf-blind patient.

In this work, a case study of the first deaf-blind patient implanted with the Combi-40 cochlear implant is analyzed. The patient is a 69-year-old man who has been blind since the age of 25 and deaf since the age of 51. Before surgery, his wife used Braille and finger-spelling on his hand to communicate with him. In this study, we intend to show how the rehabilitation program was applied to his particular characteristics and to describe the problems we faced throughout the process. Significant improvements in the dynamic ranges of perception and comprehension of segmental features of speech were observed within two weeks after the setting up. Within four weeks, the patient was able to maintain a simple conversation through the cochlear implant alone, and he abandoned the use of tactile communication. Nowadays, he is able to speak over the phone. A battery of tests was performed 2, 4 and 6 months after the switch-on. The results obtained for this patient, whose scores are among the best in our experience, suggest that deaf-blind individuals may benefit from a multichannel cochlear implant as an auditory substitute.

Blindness↗
PubMedDate not supplied

Hypoadrenocorticism.

Explore the source record for details and available documents.

Adrenal Insufficiency↗