Incidence and pathophysiological changes in chronic two-kidney hypertension in the dog

Unilateral renal artery plication in dogs reduced renal blood flow by 80% and produced a sustained elevation in arterial pressure whereas plasma renin activity increased for only 4 days. Sodium was retained for 3 days after plication, but this response is similar to that after a sham operation. Of seven dogs studied chronically, elevated arterial pressure was sustained for 27 days or longer in six animals. In three dogs hypertension continued for 2 mo before collateral vessels developed and arterial pressure fell; ligation of these collaterals restored hypertension. Arterial pressure was unaffected by an infusion of [1-sarcosine, 8-alanine] angiotensin II in chronic hypertensive dogs on a normal sodium intake. This angiotensin antagonist lowered arterial pressure after sodium depletion, but became ineffective following rapid sodium repletion. Chronic hypertensive dogs showed normal responses to deoxycorticosterone acetate. These findings suggest that the renin-angiotensin system is not critically involved in maintenace of chronic two-kidney renovascular hypertension in the dog. The data also show that the homeostatic role played by the renin-angiotensin system in the maintenance of arterial pressure remained intact in chronic hypertension.     

The Glu318Gly mutation of the presenilin-1 gene does not necessarily cause Alzheimer's disease

In early-onset familial Alzheimer's disease (AD) pathogenic mutations have been found in the amyloid precursor protein (APP) gene and in the presenilin (PS)-1 and PS-2 genes. We screened for mutations in these genes in 20 patients with familial AD from the Finnish population. In addition, we sampled 41 sporadic AD patients and 59 controls to test for mutations identified in our familial AD cases. We detected an A-to-G transition in the PS-1 gene, resulting in a glutamic acid (Glu)-to-glycine (Gly) substitution at codon 318 in 2 familial and 2 sporadic AD patients. The Glu318Gly mutation has previously been reported to cause AD. We also found the Glu318Gly mutation in 4 healthy aged controls (range, 74-87 years). We thus conclude that the mutation is most likely a rare polymorphism not related to AD.     

Summary of the Closing Session

Plausible costs of photovoltaic power plants of concentration are presented. Costs are based as much as possible on the recent experience of solar thermal plants. Efficiencies, on the existing world experience of PV power plants. The result is that the costs of concentrating photovoltaic plants should be of 0.08 ECUs/ kWh, about 1/3 of that of flat module plants, and of the same order of magnitude, even lower, than those attributed to solar thermal plants of present technology.

For the future, high concentration systems based on Si or tandem cells seem to be the most promising, also in the range of costs of the advanced solar thermal plants.     

What is new in bladder cancer imaging

Treatment and prognosis of urinary bladder cancer largely are determined by the tumor stage and presence of metastases. MR imaging and clinical staging complement each other. MR imaging is the most accurate technique for differentiating the various stages of deep tumor infiltration and detection of metastases, whereas clinical staging is the best technique for differentiating between postbiopsy effects and the various stages of superficial tumors. The role of MR imaging in staging of this disease and monitoring of therapy is reviewed and illustrated. Finally, the authors present an overview of current and future applications of this technique.