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Biomedical subjects

J C Barnett

Publications and source records attributed to J C Barnett.

11 recordsLinked to original sources
PubMed1993

Coronary venous retroperfusion of arterial blood for the treatment of acute myocardial ischemia.

Synchronized coronary venous retroperfusion of autologous arterial blood was offered to patients referred for medically refractory unstable angina or evolving myocardial infarction with contraindications to thrombolytic therapy. Primary endpoints of angina, ST segment deviation, and two-dimensional echocardiographic systolic wall motion were followed to determine the efficacy of retroperfusion in patients prior to and then during angioplasty, surgical intervention, or pharmacological management, as the clinical picture warranted. Over a 12 month period, 21 patients were referred and 15 received retroperfusion. All experienced full relief of angina (p = 0.008). ST segment deviations and systolic wall motion of ischemic zones were observed to improve (p = 0.06 ST changes; p = 0.0001 wall motion changes) with synchronized retrograde perfusion. During attempts to remove patients from retroperfusion, statistically significant (p < 0.01) reproducible changes in these same endpoints were documented. Retroperfusion appears to improve acute myocardial ischemia. This technique functions well in the intensive care unit environment with only fluoroscopy as technical imaging support.

Aged↗
PubMed1992

Massive bifrontal epidermoid tumor.

There have been 27 cases of epidermoid tumor reported to arise from the frontal or ethmoid sinus area. We report the case of a virtually asymptomatic massive bifrontal epidermoid tumor arising from the ethmoid sinus in a 76-year-old male.

Aged↗
PubMed1990

Guiding catheter exchange during coronary angioplasty.

A new technique to exchange one angioplasty guiding catheter for another with the guide wire in place and across a coronary artery stenosis has been developed to decrease the dangers of having to recross the stenosis with a guide wire. This technique utilizes a regular extended angioplasty guide wire and enables the exchange of guiding catheters during the angioplasty procedure. In 683 consecutive angioplasty procedures by one operator, this technique has been attempted 57 times in 43 patients (6.3%) and has been successful 51 times (90%). The only failures were when the second catheter had a large or open curve (left Amplatz II, 5/22 unsuccessful or multipurpose, 1/3 unsuccessful). There have been no complications. We conclude that exchange of a guiding catheter over a guide wire by the method described is safe and helpful in cases where different guiding catheters are needed for back-up power once the lesion has been crossed with a guide wire.

Angiography↗
PubMed1990

Therapy of ischemic cardiomyopathy with pentoxifylline.

Abnormal blood rheology is a known characteristics of coronary artery disease. The authors evaluated the effects of pentoxifylline on the exercise capacity ejection fraction and symptoms of 9 patients with ischemic cardiomyopathy. All patients had signs and symptoms of left ventricular dysfunction. All had at least two major vessels obstructed as determined by coronary angiography. Pentoxifylline 400 mg three times daily was administered for twelve weeks. Seven of 9 patients responded with increases in ejection fraction and exercise tolerance. Exercise tolerance correlated with improvement or lack of improvement in ejection fraction. For all patients at twelve weeks post-therapy mean ejection fraction increased 9.8% over baseline (p = .07), total treadmill time increased 15% (p = .27), and mean double product increased 13% (p = .03). Anginal symptoms were significantly improved over baseline at twelve weeks of therapy (p greater than .001), as well as dyspnea on exertion (p = .03). Pentoxifylline was well tolerated. Pentoxifylline may benefit ischemic cardiomyopathy by improving coronary perfusion owing to favorable alterations in hemorheologic properties.

Blood Pressure↗
PubMed1990

Short-term control of supraventricular tachycardia with verapamil infusion and calcium pretreatment.

Nineteen consecutive patients with atrial fibrillation/flutter or other types of supraventricular tachycardia were given intravenous (IV) calcium salts (1 g) followed by verapamil infusion at a rate of 1 mg/min. Successful treatment was defined as control of ventricular response to less than or equal to 100 beats per minute (bpm) or conversion to sinus mechanism in patients with atrial arrhythmias: 11 patients had atrial fibrillation; three had atrial flutter; four had reentrant supraventricular tachycardias (SVT); and one had paroxysmal SVT. Therapy was successful in all patients. The mean dose of verapamil required to achieve desired outcome was 20 mg. Heart rate showed no significant change as a result of calcium pretreatment (160 bpm v 151 bpm). However, heart rate was significantly decreased, to 95 bpm, after treatment with verapamil. Blood pressure showed no change from baseline with either calcium or verapamil therapy. Verapamil infusion following IV calcium successfully treats atrial fibrillation/flutter or SVTs without depressing systemic blood pressure.

Aged↗
PubMedDate not supplied

Restriction endonuclease analysis of Marek's disease virus DNA: differentiation of viral strains and determination of passage history.

The restriction endonuclease (RE) patterns of DNA from serotype 1 Marek's disease viruses (MDVs) are unique to serotype 1 viruses and can also be used to differentiate between low and high cell-culture-passaged viruses. We compared the RE patterns of DNA from seven serotype 2 and 3 MDVs before and after serial in vitro passage. Passage of four serotype 2 strains resulted in a variety of changes in the RE pattern. Individual strains within a serotype exhibited unique restriction patterns that allowed individual isolates to be differentiated. In a similar manner, the serotype 3 virus strains displayed RE pattern variations that were unique to each strain, as well as differences between low and high cell-culture passage. Our findings, together with earlier reports, suggest that the RE patterns of MDV DNA provide a simple and accurate method to: 1) differentiate between the three MDV serotypes, 2) differentiate between virus strains within a serotype, and 3) determine whether the viruses have been passaged extensively in cell culture.

Animals↗
PubMedDate not supplied

[Implantation of mitral valve prosthesis with continuos suture].

The results obtained in 20 patients with the use of continue suture technic for prosthetic implantation of the mitral valve were compared to those observed in other 20 patients in which the prothesis were implanted with isolated suture technic. With the first one the aortic clamp time was reduced in average about 50 minutes; the extracorporeal circulation time also diminished in the same proportion. One patient died in each group, meaning a 5% of hospital mortality. The going after time in the first group was 2.5 years and in none was found prosthetic dysfunction or perivalvular lickage. We conclude that prosthetic implantation technic for mitral valve with continue suture, offers the following advantages: a) Important reduction of the transoperative myocardial ischemia. b) Reduction also, of the hole estracorporeal circulation time. c) Minor possibilities of periprosthetic lickage. d) Minor risk of valvular thrombosis in the suture line.

Adolescent↗