Measurement of right ventricular dP/dt. A simultaneous/comparative hemodynamic and Doppler echocardiographic study]

Right ventricular systolic function is difficult to assess by Doppler echocardiography. We studied 14 patients with tricuspid regurgitation on Doppler echocardiographic examination with the object of determining an index of right ventricular contractility based on the continuous Doppler signal of the regurgitant jet. The rate of increase in right ventricular pressure was calculated between 2 points, V1 and V2, situated on the ascending limb of the velocity profile of the tricuspid regurgitation and compared with the dP/dt max measured simultaneously at right heart catheterisation. The different values of V1 and V2 were: 0 and 1 m/s, 0 and 2 m/s, 0.5 and 1.5 m/s, 1 and 2 m/s and 0.5 and 2 m/s. An excellent correlation was observed between the catheter dP/dt max and the rate of increase in pressure measured by Doppler between 0 and 2 m/s (r = 0.93; p = 0.0001) and between 0.5 and 2 m/s (r = 0.93; p = 0.0001). The correlation was not as close between 0 and 1 m/s (r = 0.69; p = 0.048) and there was no correlation with the measurements between 0.5 and 1.5 m/s and between 1 and 2 m/s. Doppler echocardiography could therefore be used for non-invasive assessment of right ventricular systolic function in clinical practice.     

Left internal carotid artery dissection presenting with headache, Collet-Sicard syndrome and sustained hypertension

The baroreflex maintains blood pressure through the glossopharyngeal (IX) cranial nerve. We report a 54-year-old man who developed a left sided headache, hoarseness, dysarthria, dysphagia, and sustained hypertension from a left internal carotid artery dissection. We hypothesise that interruption of the left IX nerve caused hypertension in this patient.     

Central benzodiazepine receptors in human brain: estimation of regional Bmax and KD values with positron emission tomography.

Studies of central benzodiazepine receptors in the human brain in vivo are now possible using positron emission tomography (PET) and [11C]flumazenil. With the aim of measuring Bmax and Kd in brain regions, we used a two-injection [11C]flumazenil (at high and low specific radioactivity, respectively) pseudo-equilibrium paradigm to evaluate, in seven unmedicated healthy volunteers, the relative merits of three 'reference' structures (pons, hemispheric white matter and corpus callosum) in which the free radioligand concentration in brain tissue was estimated 15-40 min after i.v. injection of the radioligand. By means of high-resolution PET, the Bmax and Kd were calculated for each subject in 18 gray matter structures, based on a two-point Scatchard plot. We found that the use of the corpus callosum as reference often resulted in spurious Bmax and Kd values. The pons was the best reference structure because it provided satisfactory Bmax values (closest to in vitro data) and most consistent Kd values, and was the region easiest to sample on PET images. The pattern of regional Bmax was consistent with that expected from in vitro studies, with values highest in the cerebral cortex, intermediate in the cerebellum, and lowest in the striatum and the thalamus. The Kd values were uniform among regions and were consistent with earlier in vitro and in vivo data. This work documents the feasibility of estimating Bmax and Kd of central benzodiazepine receptors in multiple brain regions for clinical research.     

Spontaneous disappearance of an intracranial aneurysm after subarachnoid hemorrhage.

Spontaneous disappearance of an intracranial aneurysm after subarachnoid hemorrhage is an uncommon event and usually associated with severe cerebral vasospasm, giant aneurysms or the use of antifibrinolytics. We present a young woman who suffered a grade 5 subarachnoid hemorrhage with severe vasospasm caused by a small anterior communicating artery aneurysm. The patient underwent a slow recovery and two years later requested surgery. Angiography demonstrated complete disappearance of the aneurysm. The neurosurgeon should be aware that spontaneous thrombosis of cerebral aneurysms can occur and ensure that angiography is repeated when surgery is significantly delayed.     

Myofibroblasts and the progression of diabetic nephropathy

Background. The cellular mediators of progressive renal fibrosis in diabetic nephropathy remain unknown. Myofibroblasts have been implicated in the pathogenesis of experimental and clinical renal fibrosis. Their role in the progression of diabetic nephropathy is the subject of this study.Subjects and methods. We have studied by immunohistochemistry the expression of cytoskeletal proteins associated with the activation of myofibroblasts; &agr;-smooth-muscle actin (&agr;-SMA), vimentin (Vi) and desmin (D), in the kidneys of 25 patients with diabetic nephropathy (5 patients with diabetic nephropathy (5 patients had a superimposed glomerulonephritis). Comparisons were made with normal tissue for three kidneys removed for renal-cell carcinoma. Correlations were studied between clinical and biochemical parameters with the expression renal cytoskeletal proteins. Results. In normal kidneys, cells expressing &agr;-SMA were confined to the vascular media and adventia while immunoreactive Vi was detected in glomerular epithelial cells. In diabetic kidneys, cells expressing &agr;-SMA were detected primarily in the renal interstitium and to a lesser extent in some glomeruli in association with mesangial proliferation. Vimentin immunostain decreased in glomeruli displaying diabetic hyalinosis and sclerosis. By contrast, strong Vi immunoreactivity was noted in atrophic diabetic tubules and to a lesser extent in the interstitium. Desmin was not detected in either normal or diabetic kidneys. Close correlations were observed between the expression of renal cytoskeletal proteins and the progression of renal insufficiency. Interstitial &agr;-SMA proved to be a predictor of progressive diabetic nephropathy (R² for 1/serum Cr slope=0.608, P=0.00001). This predictive parameters; tubular atrophy (R²=0.477, P=0.00004) and interstitial fibrosis (R²=0.28, P=0.001). Conclusion. We have demonstrated in this study the neoexpression of cytoskeletal proteins within diabetic kidneys. This has allowed the identification of new predicting histological markers for the progression of diabetic nephropathy.     

Liver and Pancreatic Resection in the Elderly

Background: Liver resection, or pancreaticoduodenectomy, has traditionally been thought to have a high morbidity and. mortality rate among the elderly. Recent improvements in surgical and anesthetic techniques, an increasing number of elderly patients, and an increasing need to justify use of limited health care resources prompted an assessment of recent surgical outcomes.Methods: Five hundred seventy-seven liver resections (July 1985–July 1994) performed for metastatic colorectal cancer and 488 pancreatic resections (October 1983–July 1994) performed for pancreatic malignancies were identified in departmental data bases. Outcomes of patients younger than age 70 years were compared with those of patients age 70 years or older.Results: Liver resection for 128 patients age 70 years or older resulted in a 4% perioperative. mortality rate and a 42% complication rate. Median hospital stay was 13 days, and 8% of the patients required admission to the intensive care unit (ICU). Median survival was 40 months, and the 5-year survival rate was 35%. No difference were found between results for the elderly and those for younger patients who had undergone liver resection, except for a minimally shorter hospital stay fortheyoungerpatients (median, 12 days vs. 13 days p=0.003). Pancreatic resection for 138 elderly patients resulted in a mortality rate of 6% and a complication rate of 45%. Median stay was 20 days, and 19% of the patients required ICU admission, results identical to those for the younger cohort. Long-term survival was poorer for the elderly patients, with a 5-year survival rate of 21% compared with 29% for the younger cohort (p=0.03).Conclusions: Major liver or pancreatic resections can be performed for the elderly with acceptable morbidity and mortality rates and possible long-term survival. Chronologic age alone is not a contraindication to liver or pancreatic resection for malignancy.     

Influence of variation at the apolipoprotein E locus on lipid and lipoprotein levels in CAPD patients

Background. Variation at the apolipoprotein E (apo E) locus influence lipid and lipoprotein levels in the normal population, and is associated with premature coronary artery disease. Patients with end-stage kidney disease or undergoing dialysis treatment are particularly prone to develop accelerated atherosclerosis. Methods. To evaluate the influence of genetic variation at the apo E locus, apo E genotypes and serum lipid and lipoprotein levels were measured in 51 subjects undergoing continuous ambulatory peritoneal dialysis (CAPD). Results. The distribution of apo E phenotypes and apo E allelic frequency among the CAPD subjects (&egr;2 0.049; &egr;3 0.745; &egr;4 0.206) corresponded to the healthy Swedish population. In the CAPD subjects, total serum and LDL cholesterol levels were high (6.7±1.5 mmol/l and 4.2±1.3 mmol/l respectively) and HDL cholesterol levels were low (1.2±0.5 mmol/l). When directly comparing the two major apo E groups, E 3/3 subjects (n=30) and E4/3 and 4/4 subjects, &egr;4-carriers, (n=16), LDL cholesterol levels were significantly higher among &egr;4-carriers (4,8±1.1 vs 4.0±1.2 mmol/l, P<0.03), but total serum cholesterol levels was not higher among the &egr;4-carriers (7.3±1.3 vs 6.5±1.5 mmol/l, P<0.08). Serum triglycerides or HDL cholesterol levels did not differ significantly between &agr;3-homozygotes and &egr;4-carriers. Conclusions. The results demonstrate a strong effect of variation of the apo E locus on LDL cholesterol levels in CAPD subjects, suggesting that &egr;4-carriers may be more susceptible to accelerated development of atherosclerosis in this condition.