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Biomedical subjects

R Dinsmore

Publications and source records attributed to R Dinsmore.

At least 19 recordsLinked to original sources
PubMed1995

Coronary vascular reactivity is abnormal in patients with Chagas' heart disease.

Symptoms of myocardial ischemia, such as chest pain (sometimes with anginal features), acute myocardial infarction, and segmental wall motion abnormalities (including left ventricular apical aneurysm), frequently occur in patients with Chagas' heart disease. Because these clinical findings occur in the presence of normal coronary arteries, it is possible that an abnormality of the coronary vascular reactivity could be present in these patients. Therefore the current study was undertaken to determine whether endothelium-dependent coronary vasodilation is abnormal in Chagas' heart disease. Coronary endothelial function was assessed by infusing the endothelium-dependent vasodilator acetylcholine (10(-8) to 10(-6) mol/L) and the endothelium-independent vasodilator adenosine (10(-4) mol/L) into the left anterior descending coronary artery of nine patients (age 43 +/- 4 years) with Chagas' heart disease. Coronary blood flow was measured with a Doppler flow velocity catheter and by quantitative coronary cineangiography. The left ventricular ejection fraction was 39% +/- 5%; eight patients had a left ventricular apical aneurysm; and one had an area of anteroapical hypokinesis. An impairment of the endothelium-dependent coronary vasodilation was demonstrated by a reduction in coronary blood flow of 41.2% +/- 12.8% produced by the infusion of acetylcholine at 10(-6) mol/L and by a blunted but preserved increase in coronary blood flow of 114.6% +/- 65.0% with the infusion of adenosine at 10(-4) mol/L (p = 0.03). In conclusion, patients with Chagas' heart disease have an abnormality of the coronary endothelium-dependent vasodilation, and this abnormality may play a role in their chest pain syndrome and in the development of segmental wall motion abnormalities.

Acetylcholine↗
PubMed1987

Cardiac function: evaluation with fast-echo MR imaging.

Magnetic resonance (MR) imaging of the heart has, to date, been limited in its ability to evaluate cardiac function. The authors have implemented a technique for functional assessment of the heart using shorter echo times than those generally used for conventional spin-echo imaging. With these short echo times, multiple images can be obtained in a multisection mode approximately within the isovolumetric phases of the cardiac cycle. This permits a pair of image stacks to be obtained, one in end systole and the other in end diastole. With the use of a modified Simpson rule, left ventricular volume and ejection fraction were calculated and compared with results obtained from contrast material-enhanced ventriculography. Preliminary results indicate that this method has promise for the evaluation of a variety of functional parameters in the heart. The short acquisition times for this functional study permit it to be combined with a tissue characterization study within the time constraints of a clinical MR imaging session.

Heart Function Tests↗
PubMed1986

Spectrum of conditions initially suggesting acute aortic dissection but with negative aortograms.

Between 1963 and 1983, 55 patients presented to our hospital with a clinical picture that suggested aortic dissection but with aortograms that were interpreted as negative for that entity. In 4 patients, the aortographic findings subsequently proved to be false negative. The remaining 51 patients had the following diagnoses: myocardial infarction in 9 patients; aortic regurgitation in 5; thoracic nondissecting aneurysm in 4; musculoskeletal pain in 4; mediastinal tumor in 4; pericarditis in 3; acute coronary insufficiency in 3; cholecystitis in 2; miscellaneous in 3; and unknown in 14. The clinical features in these patients were compared with those of 125 patients with true aortic dissection. Three features were significantly more prevalent in patients with than without dissection: prior systemic hypertension, pain for 24 hours or less, and migratory pain. Patients without dissection were younger than those with distal dissection and had significantly less systemic hypertension, posterior thoracic pain and migratory pain. Patients without dissection had significantly less frequent congestive heart failure, pulse deficits and aortic regurgitation, and more frequent hypertension and pain for more than 24 hours than patients with proximal dissection. This study defines the actual differential diagnosis of aortic dissection at our hospital, the frequency of false-negative aortographic findings and contrasts the clinical features of patients with and without dissection.

Age Factors↗
PubMed1985

Lymphoma of host origin in a marrow transplant recipient in remission of acute myeloid leukemia and receiving cyclosporin A.

Lymphomas are an uncommon complication of solid organ transplantation and rarely occur after marrow transplantation. When post-marrow transplant lymphomas have occurred, they have been of donor cell origin and when sought, Epstein-Barr virus DNA has been found in the tumor. A 21-year-old woman developed a poorly differentiated lymphocytic lymphoma 6 months after bone marrow transplantation for acute myeloid leukemia in remission. Cyclosporin A had been used as an immunosuppressant. A chromosomal polymorphism demonstrated that the tumor was of host origin and contained a monoclonal tumor marker, 46,XX INV 4 (p16q12). The tumor did not contain the DNA of the Epstein-Barr virus.

ABO Blood-Group System↗
PubMed1984

Comparison of the echocardiographic and hemodynamic diagnosis of rheumatic tricuspid stenosis.

Two-dimensional echocardiography has proved to be reliable in the diagnosis of mitral, aortic and pulmonary stenosis. Its role in the diagnosis of rheumatic tricuspid stenosis is still being defined; therefore, the tricuspid valve echograms of 147 patients with rheumatic heart disease were examined. Thirty-eight of these patients also underwent hemodynamic evaluation. Tricuspid stenosis was defined echocardiographically as diastolic anterior leaflet doming, thickening and restricted excursion of the other two tricuspid leaflets and decreased separation of the leaflet tips. Using these criteria, the sensitivity and specificity of the echocardiogram in detecting tricuspid stenosis were 69 and 96%, respectively, in the group of 38 patients who had both echocardiographic and hemodynamic evaluations. However, when the smaller group of 17 patients who had simultaneous right atrial and right ventricular pressure recordings were considered separately, there was complete agreement between the echocardiographic and hemodynamic data. Thus, the two-dimensional echocardiogram is a sensitive and specific test for diagnosing rheumatic tricuspid stenosis. In addition, these data provided an opportunity to determine the prevalence of tricuspid stenosis in this group of patients with chronic rheumatic valvular disease. Tricuspid stenosis was present in 14 (9.5%) of the total group of 147 patients who had two-dimensional echocardiograms, and in 10 (26.3%) of the 38 who had both echocardiographic and hemodynamic studies. In patients with rheumatic heart disease about to undergo cardiac catheterization, an echocardiographic study should prove useful in making the diagnosis of tricuspid stenosis.

Adult↗
PubMed1984

Allogeneic bone marrow transplantation for patients with acute nonlymphocytic leukemia.

Seventy patients with acute nonlymphocytic leukemia (ANLL) underwent allogeneic bone marrow transplantation following cytoreduction with total body irradiation and cyclophosphamide. Thirty patients underwent transplantation in first remission, 11 in second remission, 3 in third remission, and 26 in relapse. At a median follow-up of 30 mo, 17 of those in first remission and 7 of those in second remission survive in continuous remission, compared to 1 in third remission and 3 in relapse. The 3-yr Kaplan-Meier probability of disease-free survival among the various groups was 55% (+/- 9.2%) for the first remission transplants, 64% (+/- 14.5%) for second remission, 33% (+/- 20%) in third remission, and 10.3% (+/- 6.3%) in the relapse group. Statistical analysis showed a similar survival in the first and second remission groups that was significantly better than that seen in the third remission and relapse groups (p less than 0.01). The improved survival seen in the early remission groups was due to a significant decrease in the incidence of relapse posttransplant (p less than 0.01). These results confirm observations that a significant number of patients transplanted in first remission may achieve extended disease-free survival and document similar results for patients transplanted in second remission.

Acute Disease↗
PubMed1983

Hyperfractionated total body irradiation for bone marrow transplantation. Results in seventy leukemia patients with allogeneic transplants.

From May, 1979 to March, 1981, 76 leukemia patients were prepared for bone marrow transplantation (BMT) with a new hyperfractionated total body irradiation (TBI) regimen (1320 cGy in 11 fractions, 3x/day), followed by cyclophosphamide, 60 mg/kg, for two days. Partial lung shielding was done on each treatment, with supplemental electron beam treatments of the chest wall to compensate, and of the testes, a sanctuary site. This regimen was initiated to potentially reduce fatal interstitial pneumonitis as well as decrease leukemic relapse. These patients were analyzed in May, 1982, for a minimum follow-up of 14 months. Overall actuarial survival at 1 year for acute non-lymphocytic leukemia (ANLL) patients is 63%, while relapse-free survival at 1 year is 53%. For those ANLL patients who underwent BMT while in remission (first, second, and third combined), relapse-free survival is 61% at 1 year compared with 40% for those patients who had their BMT at the time of relapse (greater than or equal to 10% blasts in marrow). On the other hand, for acute lymphocytic leukemia (ALL) patients, there is no significant difference between relapse or remission patients with regard to overall survival or relapse-free survival, when relapse is defined as greater than 5% blasts in the marrow at the time of cytoreduction. Overall actuarial survival at 1 year for ALL is 61% and relapse-free survival is 45% at 1 year. Patients with ALL who had their BMT cytoreduction at the time of relapse have a survival equal to that of our remission patients, and greater than that of patients in relapse cytoreduced with a single dose as reported by others. However, patients with greater than or equal to 10% blasts have not fared as well, having only a 22% 1 year relapse-free survival compared with a 68% 1 year relapse-free survival for patients with less than 10% blasts. Fatal interstitial pneumonitis has dropped to 18% compared with 50% in our previous single-dose TBI regimen (1000 cGy), in which the same doses of cyclophosphamide were given prior to TBI. In conclusion, not only has fatal interstitial pneumonitis been reduced by hyperfractionation and partial lung blocking, but there may be a survival advantage in ALL patients in relapse, who have a survival equal to that of remission patients. This may indicate a greater cell kill with the higher dose (1320 cGy) attained with this regimen, in these patients with a higher leukemic cell burden.

Adolescent↗
PubMed1983

Mucormycosis following bone marrow transplantation.

Disseminated mucormycosis, presenting with a cutaneous lesion, developed in a 20-year-old woman following bone marrow transplantation. The infecting organism was identified as Rhizopus rhizopodiformis. Despite early diagnosis and therapy with amphotericin B, the patient died.

Adult↗
PubMed1983

Allogeneic bone marrow transplantation for patients with acute lymphoblastic leukemia.

Fifty-two patients with acute lymphoblastic leukemia (ALL) underwent allogeneic bone marrow transplantation following cytoreduction with total body irradiation and cyclophosphamide. Twenty-two patients were in second remission, 15 in a later remission, and 15 were in relapse at the time of the transplant. At a median follow-up of 24 mo, 14 of those in second remission survive in continuous remission compared to 5 in later remission and 4 in the relapse group. Statistical analysis showed an improved disease-free survival for the second remission group (p = 0.09). Patients transplanted in later remission or relapse had a similar survival. The improved survival in second remission resulted from a decreased relapse rate posttransplant, as the early mortality from nonleukemic causes was similar among the groups (p = 0.01). In the second remission patients, no characteristics of the initial leukemia were identified that significantly affected outcome. In the combined later remission and relapse group, poor prognosis posttransplant was associated with initial WBC greater than 20K, age at diagnosis older than 10, or initial remission duration less than or equal to 1 yr. These results suggest that extended disease-free survival may be achieved by second remission transplantation and that improved therapy is necessary for later remission or relapse transplants due to the high rate of posttransplant relapse.

Adolescent↗
PubMed1982

Bone marrow transplantation: current status.

During the past decade, the results of BMT have dramatically improved with an increasing number of long-term survivors in diseases that were previously fatal. These results are gratifying and probably indicate an increased cure rate through the use of marrow transplantation. However, the recent advances have occurred partially due to better patient selection for transplantation as in the untransfused aplastic patient or the leukemic patient in early remission. Problems remain which still limit both the success and applicability of marrow transplantation. These are the challenges of the 1980s which, if overcome, will lead to the extension of BMT to other blood and genetic diseases.

Acute Disease↗
PubMed1982

High pressure liquid chromatographic determination of cyclosporin-A in human plasma.

Periodic monitoring of plasma drug concentrations has been suggested as a means whereby the toxicity of Cyclosporin A (CyA) can be reduced in patients undergoing bone marrow transplantation. We have developed a sensitive and specific method for the determination of CyA in plasma using reverse phase high pressure liquid chromatography (HPLC). Cyclosporin D was used as the internal standard. The lower limits of detection are 100 ng/ml in biological fluids and 20 ng per injection onto the column. We have analyzed plasma samples from patients who received CyA at doses which ranged from 8 to 15 mg/kg/day. Although all patients experienced toxic or therapeutic effects, plasma concentrations of CyA were consistently less than 100 ng/ml when analyzed by this method. We conclude that analytical methods currently available for the detection of CyA are unsuitable for the monitoring of patients who receive this agent.

Chromatography, High Pressure Liquid↗
PubMed1979

Effects of coronary bypass grafting on resting left ventricular contraction in patients studied 1 to 2 years after operation.

Left ventricular contraction was evaluated with angiography in 51 patients 1 to 2 years after coronary arterial bypass surgery. The left ventricle was classified into five segments, and segmental ventricular wall motion was analyzed with subjective and objective methods. With subjective analysis, 25 percent of asynergic segments showed improvement, 72 percent no change and 3 percent deterioration in contraction. There was a 5 percent incidence rate of new wall motion abnormalities in segments that were judged normal from the preoperative ventriculogram. Objective analysis revealed significant improvement in contraction of asynergic segments in each of the five left ventricular segments analyzed. Thus, 1 to 2 years after coronary bypass surgery, there was a significant reduction in left ventricular segmental wall motion abnormalities, and the incidence of deterioration in contraction was small.

Coronary Artery Bypass↗