Quantitative (82)Rb PET/CT: development and validation of myocardial perfusion database.

The use of myocardial perfusion (82)Rb PET/CT studies continues to increase but its accuracy using database quantification methods for the diagnosis of coronary artery disease (CAD) has not been established. METHODS: A sex-independent normal database and criteria for abnormality for rest-stress (82)Rb PET/CT myocardial perfusion imaging were developed and validated by evaluation of 281 patients (136 females: mean age +/- SD, 63.3 +/- 13.3 y; 145 males: mean age +/- SD, 63.9 +/- 12.8 y) who underwent a rest-adenosine stress (82)Rb PET/CT study. These patients were divided into 3 groups: (a) healthy group: 30 patients, with <5% likelihood of CAD (low likelihood [LLK]) based on sequential Bayesian analysis; these patients were used to generate the normal distribution; (b) pilot group: 174 patients; these patients were used to determine the optimal criteria for detecting and localizing the perfusion abnormality; and (c) validation group: 76 patients (23 with LLK of CAD and 53 who underwent coronary angiography; these patients were used for prospective validation. RESULTS: Of the 53 patients who underwent coronary angiography, 8 had <50% stenosis and 45 patients had at least one stenosis > or =50% in one major artery. Fifteen patients had single-vessel disease, 17 had double-vessel disease, and 13 had triple-vessel disease. The prospective validation shows a normalcy rate of 78% (18/23) for global CAD. The analyses by individual arteries show a normalcy rate of 96% (22/23) for the left anterior descending coronary artery, 96% for the left circumflex coronary artery (22/23), and 100% for the right coronary artery (23/23). The overall sensitivity for detection of CAD (> or =50% stenosis) was 93% (42/45). The overall specificity for detection of the absence of CAD (< or =50% stenosis) was 75% (6/8). Also, the positive predictive value for global CAD was 95% (42/44), the negative predictive value was 67% (6/9), and the accuracy was 91% (48/53). CONCLUSION: The quantitative (82)Rb PET/CT database created and validated in this study is highly accurate for the detection and localization of CAD. Physicians should consider using the quantitative output of these algorithms as decision support tools to aid with image interpretation.     

Seminested polymerase chain reaction (PCR) for detecting Helicobacter pylori DNA in carotid atheromas.

A polymerase chain reaction (PCR) method for the detection of the glmM gene, selected as Helicobacter pylori target sequence, was improved. While performing pathogenicity island cagA gene detection to discriminate pathogenic strains in atherosclerotic carotid samples, several cagA-positive but glmM-negative samples were found. Polymorphisms present in the region amplified in the nested PCR reaction could explain this result; primers were therefore designed to perform a seminested reaction; this modification optimized sensitivity while maintaining specificity. A real-time PCR for Helicobacter DNA detection was also setup. The combination of all 4 PCR reactions detected 83% of H. pylori DNA-positive samples in atherosclerotic carotid tissue, 64% of which were cagA gene positive.     

Nicardipine improves motor tics

Calcium channel blockers can act on dopaminergic systems, and some reports suggest that they could be useful for the treatment of several movement disorders. In order to assess the efficacy of nicardipine in tics disorders we performed a prospective open non-controlled study which included 10 previously untreated patients. Our results suggest that nicardipine could be a useful and safe treatment for tics.     

Pallidotomy in Parkinson's disease improves single-joint, repetitive, ballistic movements, but fails to modify multijoint, repetitive, gestural movements.

We studied 12 non-demented PD patients in on state before and 3 months after posteroventral pallidotomy (PVP), in order to evaluate the effects of surgery upon an unconstrained, multijoint skilled movement as well as a single joint, repetitive, ballistic movement. A Selspot II System was used for three-dimensional data acquisition, processing and reconstruction of limb trajectories. Specific wrist kinematic features of spatial accuracy (linearity and planarity), temporal attributes (acceleration and velocity), spatiotemporal relationships (velocity-curvature coupling), and joint kinematic variables (relationships between wrist and elbow velocities and relative arm angle amplitudes) for each cycle of movement were graphically and numerically analysed. QMC was applied to single joint, repetitive, ballistic movements. QMC significantly improved after PVP (P < 0.0006). However, wrist as well as joint kinematic variables of the gestural movements failed to change significantly after PVP. The lack of improvement of the kinematic abnormalities of the gestural movement in PD patients would indicate that they are unrelated to the basic motor deficit; most likely they are the result of a disruption of a complex of sensorimotor integration processes due to abnormal parieto-frontal basal ganglia interaction.     

L-arginine reverses the antinatriuretic effect of cyclosporin in renal transplant patients

BACKGROUND: Cyclosporin has been shown to facilitate renal vasoconstriction and to have an antinatriuretic effect. The existence of an interference of cyclosporin with the vasodilating properties of endothelium mediated by nitric oxide production could mediate these effects. On the other hand, the infusion of the nitric oxide precursor L-arginine has been shown to induce renal vasodilatation and to facilitate natriuresis in normal volunteers. We have investigated the renal effects of the administration of an infusion of L-arginine in renal transplant patients chronically treated with cyclosporin. To facilitate the analysis of the data the effects of the administration of a similar dose of cyclosporin on renal function during the infusion of a vehicle were also investigated during the administration of a vehicle of L-arginine. DESIGN: Ten male renal transplant patients, chronically treated with cyclosporin and with a stable renal function were studied during 2 consecutive days after the administration of the usual morning dose of cyclosporin. The first day they received an intravenous infusion of vehicle and the second the infusion of graded doses of L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h. RESULTS: The first day, after cyclosporin administration a significant fall (P < 0.01) was observed in natriuresis and kaliuresis in the absence of changes in renal plasma flow and glomerular filtration rate. After the administration of L-arginine significant (P < 0.01) increases of renal plasma flow, glomerular filtration rate, and natriuresis were seen. The increase in blood levels of cyclosporin after its administration did not differ between days 1 and 2. CONCLUSION: These results indicate that L-arginine facilitates renal vasodilatation and natriuresis in renal transplant patients. Furthermore, the observed increase in sodium excretion could indicate that L-arginine counteracts the antinatriuretic effect of cyclosporin.      

Cyclic guanosine 3'3' monophosphate concentrations in pre-eclampsia: effects of hydralazine

Objective To elucidate the role of the L-arginine: nitric oxide pathway in pregnancy and pre-eclampsia.
Participants Pregnant women (nulliparous, age < 25 years). Normotensive pregnancy (   n = 22  ) was defined when blood pressure remained at levels of < 120/80 mmHg and there was no proteinuria. Women with pre-eclampsia (   n = 22  ) had blood pressure measurements of > 140/90 mmHg and proteinuria of > 300 mg/l. Nonpregnant normotensive women (   n = 22  ) were studied as controls.
Study Design Blood samples were taken for measurements of ionised calcium, atrial natriuretic factor, cyclic guanosine 3'5'monophophate (GMP), arginine and asymmetric dimethylarginine. Urine samples were collected for determination of cyclic GMP excretion. Cyclic GMP concentrations were also determined in 12 women with severe pre-eclampsia before and after treatment with hydralazine.
Results L-arginine, asymmetric dimethylarginine and atrial natriuretic factor were not different in any group. Cyclic GMP concentrations in plasma [0.94 (SD 0.23) nM] as well as in urine [50.1 (SD15.7)μM] were increased significantly (   P < 0.05  ) in normal pregnancy compared to nonpregnant controls [plasma mean 0.46 (SD 0.12) nM and urine mean 18.4 (SD 10.3) μM], but not in the pre-eclampsia group [plasma mean 0.48 (SD 0.10) nM and urine mean 24.1 (SD 14.5) μM]. Concentrations of cyclic GMP in plasma and urine increased significantly (   P < 0.05  ) in women treated with hydralazine.
Conclusions The differences in cyclic GMP concentrations may reflect differences in nitric oxide production. Hydralazine increases cyclic GMP concentrations in severely pre-eclamptic women. This action could explain the antihypertensive effect of hydralazine.     

Transpubic approach for lower urinary tract surgery: a 15-year experience

Surgery on lower urinary tract organs sometimes is hindered by the symphysis pubis, which by its position and bulk could severely restrict maneuverability. Since 1972 we used a transpubic approach to improve surgical exposure in 287 patients operated on for prostate, bladder or urethral cancer, post-traumatic strictures and other conditions. The type of pubectomy performed (total, partial superior or partial inferior) depended upon whether a suprapelvic or infrapelvic diaphragm organ was the primary target of the approach. Total pubectomy was used in 137 patients, partial superior bone resection in 140 and partial inferior resection in 10 patients. Technical details for each type of pubectomy are illustrated. The transpubic approach was particularly useful for repair of posterior urethral strictures or removal of bulky tumors. Among the 3 types of approaches used, total pubectomy was associated with a high complication rate including bleeding, pelvic instability, urinary incontinence and stricture of the vesicourethral anastomosis. Therefore, we have abandoned the technique since 1978. Partial pubectomy provides exposure comparable to that of total pubectomy but with minimal complications, making it an alternative to the standard approach in difficult cases.     

Analysis of cytogenetic damage induced in cultured human lymphocytes by the pyrethroid insecticides cypermethrin and fenvalerate

Two pyrethroid insecticides, cypermethrin and fenvalerate, weretested for their ability to induce chromosome structural aberrationsand sister chromatid exchanges in cultured human peripheralblood lymphocytes. Fenvalerate, but not cypermethrin, increasedthe frequencies of chromosome-type aberrations and sister chromatidexchanges. In addition, both pyrethroids affected the cell cyclecausing a decrease in the proliferative rate index at concentrations> 10 µg/ml. ¹To whom correspondence should be addressed