PubMed Health⌕ Search

Biomedical subjects

V Chang

Publications and source records attributed to V Chang.

48 records · Page 3Linked to original sources
PubMed1977

Uterine leiomyoblastoma: ultrastructural and cytological studies.

A case of uterine leiomyoblastoma is presented with ultrastructural and cytological findings. As in gastric leiomyoblastoma, fine filaments of dimensions consistent with myofilaments and marginal dense bodies are present within the tumor cells, providing evidence for the smooth muscle origin of this neoplasm. Numerous cytoplasmic vacuoles are seen in cellular samples obtained by directly scraping the lesion corresponding to the vacuoles present in glutaraledehyde-fixed material examined by electron microscopy. They do not appear to be artifacts of poor fixation and may be related to the nature of the tumor. Cytologically the cells do not resemble epithelial cells of either squamous or glandular origin and are more consistent with cells of mesenchymal origin.

Adult↗
PubMed1976

Arterial counterpulsation: review of the first 100 patients.

One hundred patients were treated with arterial counterpulsation over a 52-month period, indications being acute myocardial infarction complicated by cardiogenic shock or refractory cardiac failure, or elective cardiac surgery complicated by continued dependence on cardiopulmonary bypass. Virtually all patients showed initial improvement and 45 were hospital survivors. Serious complications of treatment were relatively infrequent. Long-term results were good, particularly in patients treated early, and in those with infarction who suffered mechanical complications that could be corrected surgically results suggest an important role of arterial counterpulsation in acute coronary artery disease.

Assisted Circulation↗
PubMed1975

Bilateral dissecting aneurysms of the intracranial internal carotid arteries in an 8-year-old boy.

Nontraumatic intracranial dissecting aneurysms have rarely been reported as the cause of acute infantile and childhood hemiplegia. The present case is unique because dissecting aneurysms occurred bilaterally in two clinically distinct episodes. A recent dissecting aneurysm of the right intracranial internal carotid artery was present with a healed dissecting aneurysm of left internal carotid artery in an 8-year-old boy.

Aneurysm↗
PubMedDate not supplied

Why are missing quality of life data a problem in clinical trials of cancer therapy?

Assessment of health related quality of life has become an important endpoint in many cancer clinical trials. Because the participants of these trials often experience disease and treatment related morbidity and mortality, non-random missing assessments are inevitable. Examples are presented from several such trials that illustrate the impact of missing data on the analysis of QOL in these trials. The sensitivity of different analyses depends on the proportion of assessments that are missing and the strength of the association of the underlying reasons for missing data with disease and treatment related morbidity and mortality. In the setting of clinical trials of cancer therapy, the assumption that the data are missing completely at random (MCAR) and analyses of complete cases is usually unjustified. Further, the assumption of missing at random (MAR) may also be violated in many trials and models appropriate for non-ignorable missing data should be explored. Recommendations are presented to minimize missing data, to obtain useful documentation concerning the reasons for missing data and to perform sensitivity analyses.

Breast Neoplasms↗
PubMedDate not supplied

Systemic mastocytosis with involvement of the pelvis: a radiographic and clinicopathologic study--a case report.

The musculoskeletal manifestations of systemic mastocytosis have been described in the literature. We present a case of systemic mastocytosis involving the pelvis. Conventional radiographs and CT imaging may demonstrate diffuse sclerotic, or mixed lytic and sclerotic lesions. On MRI, the lesions, if sclerotic, may show low signal on T1- and T2-weighted images. However, if lytic, the lesions may demonstrate low signal on T1, and increased signal on T2. As there are numerous disease entities included within the differential diagnosis, the clinical and pathological findings are crucial for establishing the correct diagnosis.

Adult↗
PubMedDate not supplied

Five-year follow-up of a randomized double-drug versus triple-drug therapy immunosuppressive trial after heart transplantation.

To determine the role of maintenance steroids in a cyclosporine and azathioprine immunosuppressive regimen, 112 heart transplant recipients were prospectively randomized to group I (n = 59; cyclosporine, azathioprine, and prednisolone) or group II (n = 53; cyclosporine and azathioprine). All patients received 7 days of induction with antithymocyte globulin. Patients receiving double-drug therapy who required four treatments for rejection were converted to maintenance steroids. This was necessary in 47% of the patients. Actuarial survival at 5 years was 82% in group I and 85% in group II. Linearized rejection in the first 3 months was lower with triple-drug therapy than with double-drug therapy (1.5 +/- 0.18 versus 2.3 +/- 0.23 episodes/100 patient days, p less than 0.01) but did not differ beyond 3 months. No significant differences were noted in 3-year left ventricular ejection fraction (0.56 +/- 0.09 versus 0.58 +/- 0.12 units), serum creatinine level (0.14 +/- 0.04 versus 0.14 +/- 0.03 mmol/L), or number with coronary artery disease (10 versus 13), diabetes, or bone complications. Patients receiving triple-drug therapy, however, had higher serum cholesterol level at 3 years (6.2 +/- 0.9 versus 5.4 +/- 1.2 mmol/L; p = 0.022) and required more antihypertensive agents (1.3 +/- 0.8 versus 0.8 +/- 0.6; p = 0.016). Similar trends emerged when patients receiving true double-drug therapy were compared with those patients who were "converted." Therapy with double versus triple immunosuppressive therapy results in similar 5-year survival and systolic function, using this protocol of converting recurrent rejectors on double-drug therapy to maintenance steroids.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMedDate not supplied

Role of routine endomyocardial biopsy to monitor late rejection after heart transplantation.

Endomycardial biopsy remains the standard used to monitor rejection after heart transplantation. There is, however, no consensus as to how often surveillance endomyocardial biopsy should be carried out after heart transplantation. We have analyzed 131 patients undergoing orthotopic heart transplantation during the first 4 years of the transplant program at St. Vincent's Hospital. The majority of endomyocardial biopsies that showed acute rejection occurred in the first 3 months after transplantation; after 9 months only 2.5% of endomyocardial biopsies performed showed rejection. Of those patients with rejection, 47% had symptoms. Seven patients experienced late rejection and all made a good recovery with normal cardiac function. We conclude that the incidence of acute rejection decreases significantly more than 3 months after-transplantation; after 9 months only 2.5% of endomyocardial biopsies will show rejection. Of these, 47% will be associated with symptoms. On the basis of experience, we believe that in our own unit, endomyocardial biopsy more than 9 months after transplantation seems unwarranted unless clinically indicated.

Adult↗
PubMedDate not supplied

Heart transplantation in females.

To confirm reports of a higher rate of rejection in female recipients of cardiac allografts and to determine whether infection rates and actuarial survival differ from that in males, we reviewed the results of 150 consecutive heart transplant procedures. Of these, 27 were in females and 123 were in males. Three different regimens were used over a 5-year period: group 1 (n = 37), cyclosporine and prednisolone; group 2 (n = 61), cyclosporine, azathioprine, and prednisolone; group 3 (n = 52), cyclosporine and azathioprine. All groups received a 7- to 10-day induction course with antithymocyte globulin. Female recipients had significantly more rejection episodes than male recipients to 3 months after transplantation (females 2.3 vs males 1.5 episodes/patient, p less than 0.01) and to 12 months (females 2.4 vs males 1.5 episodes/patient, p less than 0.02). These differences were largely caused by higher rates of rejection in females in both "double" therapy groups (groups 1 and 3). All surviving females in group 3 required the addition of maintenance steroids to control rejection. Gender mismatching of donors (male donor, female recipient) was identified as a factor associated with this requirement for conversion. Augmented treatment for rejection resulted in a higher rate of infection at 12 months in female recipients (females 1.5 vs males 0.7 episodes/patient, p less than 0.02), yet no female died of infection, and actuarial survival was comparable to that in male recipients. In view of the propensity of females to reject more frequently and earlier than males, triple therapy is currently the regimen of choice for female patients in the first 3 to 6 months after heart transplantation. Steroid withdrawal may be possible at a later time in those in whom this is indicated.

Actuarial Analysis↗
PubMedDate not supplied

Atrial overdrive pacing for reversion of atrial flutter after heart transplantation.

Atrial overdrive pacing is an effective treatment to terminate classic (type 1) atrial flutter. After heart transplantation, the appearance of atrial flutter may be an indication of acute allograft rejection, and in patients who have this arrhythmia we routinely perform endomyocardial biopsy. In this study we examined the efficacy of atrial overdrive pacing performed at the time of endomyocardial biopsy in the termination of atrial flutter. Endomyocardial biopsy was performed with a Caves-Scholten bioptome via a right internal jugular venous sheath. After completion of the biopsy, a J-shaped 5F bipolar pacing lead was inserted via the sheath and positioned with the lead tip directed medially against the interatrial septum or right atrial appendage. Atrial pacing was performed with stimulation rates up to 450 beats/min at 20 mA for 15 seconds. Since July 1989, 16 episodes of atrial flutter have occurred in nine patients. Twelve episodes (75%) were associated with acute rejection, which was moderate or severe in nine cases. Atrial overdrive pacing was successful in restoring sinus rhythm in 13 of 14 episodes during which it was attempted (success rate, 93%). The procedure was uncomplicated and produced minimal patient discomfort. In comparison, of eight episodes of atrial flutter (in six patients) that occurred before the routine use of atrial overdrive pacing, seven were associated with rejection. With treatment of rejection, two episodes reverted spontaneously, but on six occasions cardioversion with patients under general anesthesia was necessary to restore sinus rhythm. In conclusion, atrial flutter occurring after heart transplantation is usually associated with acute allograft rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Flutter↗
PubMedDate not supplied

The effect of chronic amiodarone therapy before transplantation on early cardiac allograft function.

Because of its long half-life, there has been concern that chronic amiodarone therapy before heart transplantation may adversely affect early cardiac allograft function and delay patient recovery. We retrospectively analyzed the outcome of the last 50 patients undergoing heart transplantation at our institution (between September 1988 and September 1989). Nineteen patients had been taking amiodarone at the time of transplantation (mean daily dose, 247 +/- 31 mg; mean duration of treatment, 9.0 +/- 2.2 months). These patients did not differ from the remaining 31 patients with respect to age, sex, or cause of disease. Donor organ ischemic time was also similar in the two groups (158 +/- 11 vs 153 +/- 10 minutes, NS). Patients who had received amiodarone before transplantation had significantly lower heart rates at 1 and 4 weeks after transplantation. They required atrial pacing for a longer time after transplantation compared with the remaining patients (7.3 +/- 1.4 vs 3.4 +/- 0.8 days, p less than 0.02). There was, however, no detectable effect of prior amiodarone therapy either on early allograft inotropic function or on clinical outcome. The mean time to hospital discharge was similar in the two groups. We believe that acceptance for heart transplantation should not be regarded as a contraindication to amiodarone therapy.

Adolescent↗
PubMedDate not supplied

Hyperlipidemia after heart transplantation.

Because hyperlipidemia may be a factor in the development of late graft atherosclerosis after heart transplantation, we have studied serum lipid levels in patients during the first year after transplantation. Serum cholesterol and triglyceride levels were measured in the preoperative period and at regular intervals up to 12 months after transplantation in 22 consecutive heart transplant recipients. Patients were divided into two groups: group 1 included 10 patients with underlying ischemic heart disease, and group 2 had 12 patients with underlying idiopathic dilated or valvular cardiomyopathy. Mean serum cholesterol concentrations in both groups increased substantially after operation and peaked at 3 months (respective rises of 35% and 30%). By 12 months after transplantation 50% of group 1 and 33% of group 2 manifested a significant degree of hypercholesterolemia (plasma cholesterol greater than 6.5 mmol/L, 250 mg/100 ml). Mean serum triglyceride concentrations increased in both groups during the latter part of the first year (respective increases of 44% and 13%). At 12 months only 10% of group 1 and 8% of group 2 manifested a significant degree of hypertriglyceridemia (plasma triglycerides greater than 3.0 mmol/L, 265 mg/100 ml). Over the first postoperative year there was a progressive increase in body weight, and this correlated highly with the increase in serum lipid levels (r = 0.90 for serum cholesterol and r = 0.84 for serum triglycerides). The role of conventional risk factors including hypercholesterolemia in the development of graft atherosclerosis remains uncertain, but until their role is defined, further strenuous efforts at weight control as a means of preventing or managing hyperlipidemia need to be explored.

Adult↗