Louis Essandoh - Academia.edu (original) (raw)
Papers by Louis Essandoh
Mayo Clinic Proceedings, 1987
The association of the Ehlers-Danlos syndrome with many cardiovascular abnormalities is well know... more The association of the Ehlers-Danlos syndrome with many cardiovascular abnormalities is well known. To our knowledge, however, renovascular hypertension due to renal arterial aneurysms has not previously been reported in patients with this disease. We describe a patient with type IV Ehlers-Danlos syndrome who had multiple systemic and bilateral renal arterial aneurysms and hypertension. The hypertension could have been related to compression of renal tissue or arteries (or both) by the large aneurysms, associated stenoses, or small peripheral renal infarctions. A review of all patients in whom the Ehlers-Danlos syndrome had been diagnosed at our institution between 1967 and 1985 revealed that 4 of the 200 patients had hypertension. Three of these patients, and probably all four, had secondary causes of hypertension: Cushing's syndrome, renal insufficiency, or renovascular hypertension (in the present case). We conclude that hypertension is rare in patients with the Ehlers-Danlos syndrome and that, if present, it most likely is secondary hypertension. A thorough search for secondary causes of hypertension should be undertaken in these patients.
Medicine & Science in Sports & Exercise, 1990
European Journal of Applied Physiology and Occupational Physiology, 1993
This study investigated cardiovascular responses to 2 min sustained submaximal (20% MVC) and maxi... more This study investigated cardiovascular responses to 2 min sustained submaximal (20% MVC) and maximal (100% MVC) voluntary isometric contractions of the finger flexors in healthy young women. Cardiovascular variables investigated were: heart rate (fc), mean arterial pressure (Pa), and stroke volume (SV). Doppler echocardiography was used to estimate SV from measures of aortic diameter (AD) and time-velocity integrals. Preliminary studies indicated that AD did not change significantly after 2 min sustained 100% MVC. Therefore, pre-exercise AD values were used to calculate SV before, during and after exercise. During the 2-min 100% MVC period, fc and Pa increased significantly during the first 30 s of contraction. fc then remained constant during the remainder of the 2-min contraction period, while Pa continued to rise. SV did not change significantly during the 100% MVC task but increased significantly during recovery from sustained 100% MVC. The data suggest that the magnitude of cardiovascular responses to isometric exercise is dependent on the specific task performed, and that there is a different pattern of response for fc, Pa, and SV during 20% and 100% MVC tasks. Unlike fc and Pa, SV did not change significantly during isometric exercise, but increased significantly after sustained 100% MVC.
Kidney International, 1977
Studies of the renal concentrating mechanism require a method for defining the concentration of b... more Studies of the renal concentrating mechanism require a method for defining the concentration of both urea and electrolytes in very small fluid specimens obtained from collecting ducts. Urea in such samples has been measured in the range from 20 to 100 pmoles using a fluorescence technique [1], and from 100 to 500 pmoles by absorption spectrophotometry [2]. These methods require several nanoliters of fluid and many handling steps. The electron probe microanalyzer can measure electrolyte composition in samples smaller than 10−10 liters [3–5], but because it measures only elemental composition, it has not been useful for defining organic chemical composition. We here describe a new method based on the precipitation of urea by thioxanthen-9-ol from microdroplets in the 50-pl range.
Digestive Diseases and Sciences, 1988
These results indicate the suitability of using isolated guinea pig villous and crypt cells to ex... more These results indicate the suitability of using isolated guinea pig villous and crypt cells to examine transport processess of molecules that involve specialized mechanisms. The results also demonstrate that the undifferentiated crypt cell lacks specific transport processes necessary for the active absorption of cobalamin and taurocholate.
Mayo Clinic Proceedings, 1987
The association of the Ehlers-Danlos syndrome with many cardiovascular abnormalities is well know... more The association of the Ehlers-Danlos syndrome with many cardiovascular abnormalities is well known. To our knowledge, however, renovascular hypertension due to renal arterial aneurysms has not previously been reported in patients with this disease. We describe a patient with type IV Ehlers-Danlos syndrome who had multiple systemic and bilateral renal arterial aneurysms and hypertension. The hypertension could have been related to compression of renal tissue or arteries (or both) by the large aneurysms, associated stenoses, or small peripheral renal infarctions. A review of all patients in whom the Ehlers-Danlos syndrome had been diagnosed at our institution between 1967 and 1985 revealed that 4 of the 200 patients had hypertension. Three of these patients, and probably all four, had secondary causes of hypertension: Cushing's syndrome, renal insufficiency, or renovascular hypertension (in the present case). We conclude that hypertension is rare in patients with the Ehlers-Danlos syndrome and that, if present, it most likely is secondary hypertension. A thorough search for secondary causes of hypertension should be undertaken in these patients.
Medicine & Science in Sports & Exercise, 1990
European Journal of Applied Physiology and Occupational Physiology, 1993
This study investigated cardiovascular responses to 2 min sustained submaximal (20% MVC) and maxi... more This study investigated cardiovascular responses to 2 min sustained submaximal (20% MVC) and maximal (100% MVC) voluntary isometric contractions of the finger flexors in healthy young women. Cardiovascular variables investigated were: heart rate (fc), mean arterial pressure (Pa), and stroke volume (SV). Doppler echocardiography was used to estimate SV from measures of aortic diameter (AD) and time-velocity integrals. Preliminary studies indicated that AD did not change significantly after 2 min sustained 100% MVC. Therefore, pre-exercise AD values were used to calculate SV before, during and after exercise. During the 2-min 100% MVC period, fc and Pa increased significantly during the first 30 s of contraction. fc then remained constant during the remainder of the 2-min contraction period, while Pa continued to rise. SV did not change significantly during the 100% MVC task but increased significantly during recovery from sustained 100% MVC. The data suggest that the magnitude of cardiovascular responses to isometric exercise is dependent on the specific task performed, and that there is a different pattern of response for fc, Pa, and SV during 20% and 100% MVC tasks. Unlike fc and Pa, SV did not change significantly during isometric exercise, but increased significantly after sustained 100% MVC.
Kidney International, 1977
Studies of the renal concentrating mechanism require a method for defining the concentration of b... more Studies of the renal concentrating mechanism require a method for defining the concentration of both urea and electrolytes in very small fluid specimens obtained from collecting ducts. Urea in such samples has been measured in the range from 20 to 100 pmoles using a fluorescence technique [1], and from 100 to 500 pmoles by absorption spectrophotometry [2]. These methods require several nanoliters of fluid and many handling steps. The electron probe microanalyzer can measure electrolyte composition in samples smaller than 10−10 liters [3–5], but because it measures only elemental composition, it has not been useful for defining organic chemical composition. We here describe a new method based on the precipitation of urea by thioxanthen-9-ol from microdroplets in the 50-pl range.
Digestive Diseases and Sciences, 1988
These results indicate the suitability of using isolated guinea pig villous and crypt cells to ex... more These results indicate the suitability of using isolated guinea pig villous and crypt cells to examine transport processess of molecules that involve specialized mechanisms. The results also demonstrate that the undifferentiated crypt cell lacks specific transport processes necessary for the active absorption of cobalamin and taurocholate.