Calcium entry and 5-HT2 receptor blockade in oliguric ischaemic acute renal failure: effects of levemopamil in conscious rats.

1. Unilateral left renal artery occlusion for 1 h in a group of 8 untreated female Sprague-Dawley rats resulted in oliguric acute renal failure (ARF) persisting for more than 6 h after reflow, i.e. after reperfusion of the kidney by removal of the arterial clamp. In a second group of 8 rats with left unilateral ARF the effects of levemopamil (L), a calcium entry blocker with 5-hydroxytryptamine2 (5-HT2) receptor antagonistic properties, were studied. Rats received L as a continuous infusion (6 mg kg-1 h-1) from 1 h before ischaemia until 6 h after reflow. 2. Endogenous creatinine clearance, an estimate of glomerular filtration rate (GFR), of left ischaemic kidneys of untreated rats was almost completely abolished and urine flow was 0.05 +/- 0.02 and 0.03 +/- 0.01 ml h-1 100 g-1 body weight (body wt.) at 2 and at 6 h of reflow, respectively. In contrast, left ischaemic kidneys of L-treated rats revealed significantly higher GFR (0.10 +/- 0.02 and 0.03 +/- 0.01 ml min-1 g-1 kidney weight (k.wt.); P < 0.01) and urine flow (0.51 +/- 0.05 and 0.15 +/- 0.04 ml h-1 100 g-1 body wt.; P < 0.05) at 2 and 6 h of reflow, respectively. 3. At 6 h of reflow, mitochondria from the cortex of left ischaemic kidneys of untreated rats showed significantly reduced ATP synthesis when compared to right intact kidneys (0.06 +/- 0.02 vs 0.26 +/- 0.02 mumol ATP mg-1 protein min-1 (P < 0.01)). In contrast, in L-treated rats, ATP synthesis of left ischaemic kidneys was largely preserved (0.17 +/- 0.01 mumol ATP mg-1 protein min-1). 4. Ischaemia of left kidneys resulted in a significant decrease in medullary Na-K-ATPase activity to 9.6 +/- 2.4 as compared to 20.4 +/- 3.7 mumol P(i) h-1 mg-1 protein in the intact right kidneys which was not prevented by L (9.4 +/- 2.4 mumol P(i) h-1 mg-1 protein). 5. In untreated rats the calcium content in cortical mitochondria from left ischaemic kidneys had risen 2 fold to 23.0 +/- 1.8 at 6 h of reflow as compared to 12.2 +/- 0.3 nmol mg-1 protein in right intact kidneys (P < 0.01). This rise in mitochondrial calcium was not significantly attenuated by treatment with L (19.9 +/- 1.7 nmol mg-1 protein). 6. The results show that L transiently converted oliguria into non-oliguria during the early phase after reflow in ischaemic ARF, i.e. after reperfusion following 1 h of complete interruption of renal perfusion. The present data suggest indirectly that the 5-HT2-antagonistic properties of L rather than its calcium channel blocking action maintains GFR at low level and protects mitochondrial function early after reflow in this model of ischaemic ARF.

Radiographic detectability of periodontal diseases. A comparison of perapical radiography with detailed zonography.

OBJECTIVE: To compare the diagnostic accuracy of conventional periapical radiography with detailed zonography using the Scanora system for the detection of periodontal disease. METHODS: We selected for comparison 311 periodontal sites in 165 patients. Five observers independently assessed the periapical radiographs and detailed zonograms for marginal widening of periodontal ligament space, crestal erosion, vertical bone loss, furcation involvement and calculus. RESULTS: ROC analysis revealed no significant differences between the two imaging techniques for either overall or lesion-specific interpretation of periodontal pathology. The sensitivity of periapical radiography was 79%, and of detailed zonography 91% (multiview) and 89% (stereoscopic). Specificities were 82%, 77% and 83%, respectively. CONCLUSION: Detailed zonography performs as well as periapical radiography in the detection of periodontal disease.

A comparison of detailed zonography with periapical radiography for the detection of periapical lesions.

The diagnostic accuracy of detailed zonography using the Scanora multimodal X-ray system was compared with that of periapical radiography. The study was based on the detection of periapical bone lesions at 259 dental sites distributed evenly throughout the dentitions of 164 patients. Each site was examined by periapical radiography and zonography, in parallel. The zonograms consisted of four detailed images that could also be read as stereopairs, in either the horizontal or vertical direction. Five observers evaluated the sites for the presence or absence of periapical osteolysis or sclerosis and apical widening of the periodontal ligament space for the whole dentition, and for three dental regions. ROC analysis revealed no significant overall or regional differences between the diagnostic accuracies of the periapical and zonographic techniques, regardless of whether the zonograms were read as sets of four images (multiview) or stereoscopic images. The sensitivity of periapical radiography was 72%, that of multiview zonography 88%, and that of stereoscopic zonography 85%. Specificities were 93%, 84% and 89%, respectively. The energy imparted during detailed zonography was 0.98 mJ. It is concluded that zonography is as good as periapical radiography for the detection of periapical pathology.

The use of direct confrontation: the treatment-resistant schizophrenic patient.

Schizophrenics are often labeled treatment-resistant because the psychological treatment they receive is seldom appropriate for their needs. Specialized psychotherapy for schizophrenia is available but rarely used. Training in these methods is difficult to find. If we are to treat schizophrenia successfully, we must rethink the treatment and training process, modify our views and teach interventions that force the patient to respond to the demands of the therapist. Professionals must learn that change occurs because the therapist is stronger than the psychotic defenses of the patient, i.e., the patient's resistance to treatment.