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Biomedical subjects

S G Sheps

Publications and source records attributed to S G Sheps.

At least 19 recordsLinked to original sources
PubMed1992

The clinical significance of nuclear DNA ploidy pattern in 184 patients with pheochromocytoma.

Flow cytometric nuclear DNA analysis was performed on paraffin-embedded tissue samples taken from 184 patients with pheochromocytoma and paraganglioma treated between 1960 and 1987. The Hedley technique was used for measurement of nuclear DNA content. Thirty-five percent of the tumors were DNA diploid, 33% showed a DNA tetraploid pattern, and 32% had DNA aneuploid pattern. Familial pheochromocytoma and associated endocrine or neoplastic disorders were more common among patients with DNA nondiploid tumors. Eighty-four percent of the tumors that invaded blood vessels and all patients with regional or distant metastases had tumors classified as DNA tetraploid or DNA aneuploid. Of 22 patients who had disease progression, 21 (95%) had tumors with abnormal DNA ploidy pattern (P less than 0.001). All 12 patients who died of cancer-related disease had abnormal DNA ploidy; none of the patients with DNA diploid tumor (n = 64) have died of pheochromocytoma (P less than 0.01). These results suggest that nuclear DNA ploidy pattern is an important and independent prognostic variable for patients with pheochromocytoma and paraganglioma.

Adrenal Gland Neoplasms↗
PubMed1992

Prognostic profile for patients with pheochromocytoma derived from clinical and pathological factors and DNA ploidy pattern.

Eighty-eight patients with pheochromocytoma and paraganglioma treated over a 28 year period (1960-1987) were studied. Based on clinical course, they were divided into three prognostic groups: benign (n = 57); multiple (n = 12); and metastatic (n = 19). Using clinical data, histopathologic findings, and tumor nuclear DNA content a prognostic profile for each group was constructed. The following variables were studied: age, familial pheochromocytoma, associated endocrine or neoplastic disorders, number and location of the lesion at diagnosis, size of the tumor, and the nuclear DNA ploidy pattern. Of these prognostic factors the most significant to predict a future malignant clinical course were large size and local tumor extension at time of surgery. Family history of pheochromocytoma, associated endocrine disorders, and young age at presentation predicted multiplicity. Old age, absence of familial pheochromocytoma or related endocrine disorders and DNA diploid tumors seem to be favorable findings. Using these variables in combination may be helpful for early identification of patients with malignant, multiple, or benign pheochromocytoma and paraganglioma.

Adrenal Gland Neoplasms↗
PubMed1991

Age-related characteristics of ambulatory blood pressure load and mean blood pressure in normotensive subjects.

Ambulatory blood pressure monitoring has become increasingly popular for diagnosing and treating hypertension. However, data from normotensive subjects are needed for interpretation of hypertensive readings. Ambulatory blood pressure was monitored in 126 normotensive subjects (age range, 20 to 84 years). Mean systolic and diastolic blood pressure and blood pressure loads (percentage of systolic readings greater than 140 mm Hg and diastolic readings greater than 90 mm Hg) were obtained and interpreted. Mean awake systolic and diastolic pressures ranged from 125 +/- 10 to 137 +/- 17 mm Hg and 70 +/- 8 to 71 +/- 9 mm Hg, respectively. The systolic and diastolic trends of subjects' blood pressures taken during office visits and the 24-hour measurements were similar. Ranges for systolic and diastolic blood pressure loads from youngest to oldest ages were 9% +/- 14% to 25% +/- 20% and 3% +/- 7% to 4% +/- 7%, respectively. A comparison of blood pressure means from our sample that were taken during office visits and blood pressure means from a 2122-patient community survey demonstrated that our sample was reflective of an unselected population.

Adult↗
PubMed1990

Antihypertensive effects of a new sustained-release formulation of nifedipine.

The blood pressure response to a new sustained-release formulation of nifedipine was evaluated in an 8-week, double-blind, placebo-controlled study. Twenty-nine patients with mild essential hypertension were randomized to receive placebo (N = 9), 30 mg nifedipine (N = 10), or 60 mg nifedipine (N = 10). During treatment, 30-mg and 60-mg doses of nifedipine administered once daily decreased office blood pressures from 137/98 +/- 8/2 mm Hg and 141/98 +/- 15/2 mm Hg at baseline, respectively, to 126/89 +/- 9/7 mm Hg and 126/86 +/- 6/7 mm Hg (P less than .005). Noninvasive automatic ambulatory blood pressure monitoring demonstrated a marginally significant (P less than .10) reduction in the mean 24-hour blood pressure of 2/6 +/- 8/8 mm Hg and 5/6 +/- 9/9 mm Hg for patients taking 30 mg and 60 mg nifedipine once daily, respectively. Diastolic blood pressure load (the percentage of ambulatory diastolic blood pressure readings greater than 90 mm Hg) during 24 hours was decreased by 41% and 35%, with 30 mg and 60 mg nifedipine administered once daily, respectively. No significant dose response to nifedipine at these dose levels was observed. Although the once-daily formulation of nifedipine achieved effective control of office blood pressure, similar control was not observed in awake and 24-hour periods in all patients.

Adult↗
PubMed1990

Office blood pressures in supine, sitting, and standing positions: correlation with ambulatory blood pressures.

The variability of casual (office) blood pressure according to position at the time of measurement was investigated in 168 untreated patients with a history of mild to moderate essential hypertension. Two measurements were made in the supine, sitting, and standing positions on each of 2 consecutive days, and 24-hour ambulatory blood pressure monitoring was performed. The mean supine, sitting, and standing blood pressures were 146 +/- 15/91 +/- 7, 144 +/- 15/96 +/- 8, and 149 +/- 17/103 +/- 7 mm Hg, respectively. Diastolic blood pressures were significantly different from each other (P less than 0.0001). Supine and sitting systolic blood pressures were not different, but they were different from standing blood pressure (P less than 0.0001). The mean of all three positions (overall blood pressure) was 146 +/- 15/96 +/- 7 mm Hg. Supine, sitting, standing, and overall diastolic blood pressure means were 90 mm Hg or more in 88, 133, 164, and 133 patients, respectively. The mean awake ambulatory and 24-hour ambulatory blood pressures were 143 +/- 16/95 +/- 7 and 138 +/- 16/92 +/- 8 mm Hg, respectively, and diastolic blood pressures were 90 mm Hg or more in 121 and 88 patients, respectively. The correlation of office blood pressure with ambulatory blood pressure varied according to office position and was 0.76 to 0.82 (P less than 0.0001) for systolic blood pressure and 0.60 to 0.69 (P less than 0.0001) for diastolic blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Recent developments in the diagnosis and treatment of pheochromocytoma.

The investigation and management of pheochromocytoma have been of special interest at the Mayo Clinic since 1926, when Dr. C. H. Mayo successfully removed an adrenal tumor. Recent clinical developments include the detection of asymptomatic paroxysms of hypertension by 24-hour ambulatory monitoring, detailed characterization of catecholamine cardiomyopathy by echocardiography, and further experience with Carney's triad and other polyglandular and multiple neoplasia syndromes associated with pheochromocytoma. Refinement in interpretation of catecholamine measurements and the development of radionuclide scanning with m-[131I]iodobenzylguanidine, computed tomography, and magnetic resonance imaging have greatly enhanced our diagnostic acumen. Developments in antihypertensive drug therapy and chemotherapy have improved our management of cathecholamine hypersecretion and tumor growth, respectively, in inoperable patients and in the preparation of patients for anesthesia and surgical treatment. Flow cytometry to detect abnormal DNA histograms may prove particularly useful in predicting the malignant nature of the tumors.

Adrenal Gland Neoplasms↗
PubMed1990

Reproducibility of ambulatory blood pressure load.

Twenty-two hypertensive patients were monitored during two separate drug-free occasions with a Del Mar Avionics ambulatory device. Blood pressure loads (percentage of systolic and diastolic readings more than 140 and 90 mmHg, respectively) and mean BP were measured both to determine their reproducibility and to examine how they correlate with each other. The systolic and diastolic mean awake BPs for day 1 and day 2 were 140/93 mmHg and 140/91 mmHg, respectively, and BP loads were 45%/55% and 43%/54%. Moreover, mean BP loads correlated highly (r = 0.93) with mean BP values taken on the same day. Both ambulatory mean SBP and BP load were highly reproducible (r = 0.87 and 0.80, respectively, during the awake hours), and mean DBP and load were fairly reproducible (r = 0.59 and 0.39, respectively, during the awake hours). Clinically, however, both were consistent from day 1 to day 2. Mean and individual standard deviations also were reproducible for both systolic and diastolic pressures and loads.

Adult↗
PubMed1990

Cost considerations of ambulatory blood pressure monitoring.

Automatic blood pressure monitoring has proved valuable in testing new antihypertensive drugs, providing greater precision at less cost. Results obtained by this method are better correlated with target-organ damage (e.g. left ventricular hypertrophy) than conventional office blood pressure measurements. A number of clinical conditions are better evaluated with ambulatory blood pressure monitoring than with conventional measurements, e.g. office (white coat) hypertension, episodic hypertension and intermittent hypertensive symptoms. An economic model suggests that appropriately constrained ambulatory blood pressure monitoring can be highly cost-effective in patients who are initially diagnosed as mildly hypertensive on the basis of repeated casual blood pressure measurements. Normative data are needed for populations by age, race, gender, body habitus and conditions such as pregnancy.

Antihypertensive Agents↗
PubMed1989

Clinical use of home and ambulatory blood pressure monitoring.

Blood pressure measurements made in the physician's office with a mercury-column sphygmomanometer traditionally have been the standard for diagnosis of hypertension and determination of the efficacy of antihypertensive agents. The utility of this measurement is limited, however, by the characteristic variability of blood pressure; office blood pressure readings are not always reliable indicators of pressures occurring throughout the course of the day. Therefore, blood pressure measurements performed by patients or family members at home and automatic ambulatory blood pressure monitoring are two supplementary methods used in the clinical management of hypertension. In this article, the role of these methods in the diagnosis of hypertension and other cardiovascular disorders as well as in the evaluation of the efficacy of antihypertensive therapy is addressed.

Antihypertensive Agents↗
PubMed1988

Correlation between verapamil plasma concentration and P-R prolongation in essential hypertension.

Plasma verapamil concentration was correlated with serial electrocardiographic P-R intervals in patients with essential hypertension receiving immediate-release (80 to 120 mg three times a day) or sustained-release (240 mg daily) verapamil. The mean P-R interval in 22 patients taking placebo and immediate-release verapamil was 0.18 second. The borderline first-degree atrioventricular block of three patients did not change during treatment. Plasma verapamil concentrations of patients with a P-R interval longer than 0.20 second and of those with a P-R interval of 0.20 second or less were 169 +/- 73 ng/mL and 63 +/- 8 ng/mL, respectively. Six patients taking sustained-release verapamil had a maximal mean P-R interval of 0.19 +/- 0.01 second during 24-hour ambulatory electrocardiographic monitoring. P-R intervals were 0.22 second or more in two patients, but they returned to normal by hour 7 for one and by hour 20 for the other patient. In summary, transient P-R prolongation occurred with oral verapamil therapy, but no patient, regardless of baseline P-R interval, developed high-grade atrioventricular block.

Delayed-Action Preparations↗
PubMed1988

Blood pressure load--a better determinant of hypertension.

Noninvasive ambulatory blood pressure monitoring was used to evaluate the diagnosis of hypertension in 168 untreated patients with essential hypertension. On the basis of overall office blood pressure--the mean of 12 measurements, 2 in each of three positions (supine, sitting, and standing) on 2 consecutive days--133 patients were diagnosed as having hypertension (diastolic blood pressure of 90 mm Hg or higher) and 35 as having borderline hypertension (diastolic blood pressure of less than 90 mm Hg). The mean blood pressures for those with hypertension and borderline hypertension were 149/99 and 135/87 mm Hg, respectively. The mean ambulatory diastolic blood pressure was 90 mm Hg or higher in 123 patients during awake hours and in 91 patients during 24 hours. The diastolic blood pressure loads (percentage of ambulatory diastolic blood pressures more than 90 mm Hg) in patients with hypertension and borderline hypertension, respectively, were 69% and 43% during awake hours and 59% and 35% during 24 hours. The systolic blood pressure loads (percentage of systolic readings more than 140 mm Hg) during awake and 24 hours were 56% and 48%, respectively, in patients with established hypertension and 31% and 26%, respectively, in those with borderline hypertension. Thus, ambulatory blood pressure monitoring and blood pressure load provide useful information for diagnosing hypertension.

Adult↗
PubMed1988

Carney's triad: guidelines for management.

Carney's triad--gastric leiomyosarcoma, pulmonary chondroma, and extra-adrenal paraganglioma--is a syndrome that occurs primarily in young women. To date, 28 patients with at least two of these individually unusual or rare neoplasms have been described. This updated case report of one of the originally described patients with Carney's triad highlights several clinically important features of this unusual syndrome: (1) the multicentricity of both the paragangliomas and the epithelioid leiomyosarcomas, (2) the often indolent progression of metastatic leiomyosarcoma, (3) the potential for late recurrences, and (4) the importance of distinguishing intra-adrenal from periadrenal catecholamine-producing tumors (paragangliomas). Localization of paragangliomas is facilitated by two relatively new techniques--131I-metaiodobenzylguanidine scanning (a scintigraphic technique with high specificity for catecholamine-producing tumors) and two-dimensional echocardiography (which can noninvasively localize and demonstrate the anatomic relationships of aorticopulmonary paragangliomas). In patients with this syndrome, new or recurrent tumors frequently manifest after unusually long asymptomatic intervals. We outline an approach for continued follow-up of patients with one or more of the three neoplasms that constitute the syndrome. Rigorous long-term screening of these patients should not only lead to early recognition and resection of recurrent or new tumors but also enhance our understanding of this intriguing syndrome.

Adrenal Gland Neoplasms↗