Low platelet MAO activity associated with high dysfunctional impulsivity and antisocial behavior: evidence from drunk drivers

Rationale Low platelet monoamine oxidase (MAO) activity is associated with problem drinking and other deviant behaviors. Since the majority of alcohol abusers are smokers, and tobacco smoke has a direct inhibitory effect on the enzyme, these associations may not be meaningful.Objective The authors compared platelet MAO activity and impulsivity in police-referred subjects caught driving while intoxicated and in control subjects, controlling for smoking.Methods Platelet MAO activity was measured radioenzymatically and impulsivity scores obtained from questionnaires. Smoking status was self-reported.Results Subjects caught driving while intoxicated had significantly higher dysfunctional impulsivity and lower platelet MAO activity than control subjects. This difference in platelet MAO activity between the two groups was significant in non-smokers and ex-smokers.Conclusions These findings demonstrate that platelet MAO activity is lower in subjects with socially deviant behavior, and the association of low platelet MAO and problem drinking is not an artifact of smoking.     

Effects of beta-carotene supplementation on free radical mechanism in healthy adult subjects

AIM: The objective of this study was to examine whether increasing doses of beta-carotene supplements have effects on biological markers of lipid peroxidation in healthy volunteers. SUBJECTS AND METHODS: Forty-two healthy subjects were supplemented with 5 mg, 10 mg, 20 mg or 40 mg beta-carotene/day, respectively for five weeks. Plasma beta-carotene and tocopherol levels, malondialdehyde-thiobarbituric reactive substances (MDA-TBARS), and conjugated dienes were determined using high-performance liquid chromatography (HPLC). Concentrations of ascorbic acid, uric acid, and the total antioxidative capacity (TAC) in plasma were measured photometrically. RESULTS: Plasma beta-carotene levels increased significantly according to the intervention dose (p < 0.001), and concentrations of tocopherol equivalents and ascorbic acid were within the physiological range except in the 5 mg intervention group where a significant decrease of vitamin C was assessed (p < 0.05). Uric acid in plasma decreased significantly in all groups (p < 0.05) up to the end of investigation, but was within the normal range. Trolox equivalent antioxidative capacity (TEAC) decreased significantly (p < 0.001) in all groups during supplementation. MDA-TBARS remained unchanged after five weeks except for the 40 mg beta-carotene substitution group, where a significant decrease was observed (p < 0.05). CONCLUSION: Beta-carotene supplementation of healthy subjects significantly increased plasma beta-carotene status without inducing adverse biological effects. Beta-carotene did not especially protect against oxidative stress, except for the 40 mg group. These data suggest that additional effects of beta-carotene supplementation on well-nourished, healthy subjects are limited.     

Time spent by primary care practices on pediatric influenza vaccination visits: implications for universal influenza vaccination

OBJECTIVE: To measure the time currently spent by primary care practice personnel, and the examination room occupancy time for childhood influenza vaccination visits, to assess the practicality of annual influenza vaccination of all preschool children. SETTING: Seven primary care practices serving one fourth of the children living in Rochester, NY. PATIENTS: Ninety-two children seen for influenza vaccination visits in the 2000-2001 vaccination season. METHODS: Using a standardized protocol, practice staff measured the time spent on check-in, nurse or physician examination, and the actual influenza vaccination process. Waiting and "hands-on" times were determined, as well as total visit and room occupancy times. Nonparametric tests and multivariable models were used to analyze the time spent for components of the visits and to compare time spent by different age groups and practice types (suburban or urban). RESULTS: The median duration of the influenza vaccination visit was 14 minutes (25th to 75th percentiles range, 9-25 minutes) across the 7 practices, with visits to urban practices being longer (22 minutes) than visits to suburban practices (9 minutes). Eighty percent of patient time involved waiting, primarily in examination rooms. The major components of influenza vaccination visits included waiting room time (4 minutes in suburban practices vs 8 minutes in urban practices; P<.01), and time in the examination room (5 minutes vs 14 minutes, respectively; P<.001), during which only 1 to 2 minutes (for both suburban and urban practices) were for hands-on vaccinations. Only 5% of visits were examined by a physician or nurse practitioner. Visit times did not vary by age. CONCLUSIONS: Although the personnel time for influenza vaccination visits was short, there was substantial patient waiting and long occupancy of examination rooms. If universal influenza vaccination is to be efficiently managed in primary care practices, it may be necessary to implement "vaccination clinics" or sessions in which large numbers of children are scheduled for influenza vaccinations at times when adequate rooms and dedicated nursing staff are available.     

CT in the evaluation of patients on ECMO due to acute respiratory failure

BACKGROUND: In patients with acute severe respiratory failure (ARF) treated with extracorporeal membrane oxygenation (ECMO) the radiological evaluation has until now almost exclusively relied on bedside radiography and US. At St. G?ran/Karolinska ECMO centre CT has become a routine complement to bedside examinations. OBJECTIVE: To review retrospectively the frequency, indications and findings on CT of patients with ARF on ECMO and to evaluate the risk of complications associated with transportation for CT examinations. MATERIALS AND METHODS: One hundred twelve neonates, children and adults were treated with ECMO from May 1994 to January 2001. Forty-six per cent of these patients had CT examinations on one or more occasions during ECMO, giving a total number of 238 examination sites on 104 occasions. All CT examinations were performed in the Paediatric Radiology Department and included a 10-min transport using a mobile ECMO system. RESULTS: CT was more often performed in older patients and in patients with long ECMO runs. The main indications were suspected complications of ECMO and/or the underlying disease or a delay in clinical improvement. In 57% of the CT occasions, significant findings affecting treatment were revealed. There were no complications associated with the examinations or transport. CONCLUSIONS: CT is safe and useful in evaluation of patients with ARF during ECMO.     

Renal transplantation in patients with hemolytic uremic syndrome: high rate of recurrence and increased incidence of acute rejections

BACKGROUND: The reported outcome of renal transplantation in patients with the hemolytic uremic syndrome (HUS) varies greatly, probably related to the diverse causes of HUS. In this single-center retrospective study, we have analyzed the recurrence rate, the incidence of acute rejections, and graft survival in patients suffering from adult-onset and childhood-onset HUS. METHODS: The medical records of 35 patients with end-stage renal disease caused by HUS, who received 50 renal allografts, were reviewed. A definite recurrence of HUS was diagnosed if both clinical and histologic signs of thrombotic microangiopathy (TMA) were present in the absence of any endovasculitis. If there were signs of mild endovasculitis, a probable recurrence was diagnosed. RESULTS: After first renal transplantation, 0 definite and 1 (6%) probable recurrence occurred in 18 patients with childhood-onset HUS, as opposed to 7 (41%) definite and 3 (18%) probable recurrences in 17 adult-onset HUS patients (odds ratio [OR], 13.4; 95% confidence interval [CI], 1.7-105.7). In the latter patients, early use of cyclosporine A increased the risk for recurrence. The incidence of acute rejections was increased compared with matched controls (OR, 1.52; 95% CI, 1.05-2.19 for adult-onset HUS and OR, 1.88; 95% CI, 1.34-2.62 for childhood-onset HUS). One-year graft survival in adult-onset HUS was poor (29%), whereas 1-year graft survival in childhood-onset HUS was comparable to matched controls. CONCLUSIONS: In adult-onset HUS, the recurrence rate and the incidence of acute rejections are high, resulting in a detrimental graft survival. In childhood-onset HUS, the recurrence rate is low, but the posttransplantation course is complicated by an increased incidence of acute rejections.     

Comparison of intermittent-bolus contrast imaging with conventional power Doppler sonography: quantification of tumour perfusion in small animals

Replenishment kinetics of microbubbles were adapted to a single bolus injection to investigate tumour angiogenesis in small animals with intermittent imaging, and to compare vascularisation parameters from this new approach with conventional power Doppler ultrasound (US). A reformulation of the imaging protocol and the derivation of perfusion parameters was necessary, taking into account the time-dependence of the systemic microbubble concentration after single bolus injection. Using this new method, tumour vascularisation was evaluated in 13 experimental murine tumours. Furthermore, parameters calculated with intermittent imaging after bolus injection of 100 microl Levovist were compared with parameters from the signal intensity-time curve. The results showed that quantifying tumour perfusion, blood volume and flow, as well as the assessment of the mean blood velocity (in m/s), is possible in tumours with a volume of more than 0.1 mL. In larger tumours, a lower perfusion was calculated than in smaller ones (k = -0.88; p < 0.001). Only limited correlations were found between conventional power Doppler US quantities and parameters of intermittent sonography: Perfusion correlated with the maximum signal intensity (k = 0.61, p < 0.05) and the gradient to maximum (k = 0.82, p < 0.01), full width-half maximum was associated with blood volume (k = 0.62, p < 0.05). We conclude that intermittent bolus contrast sonography allows the quantification of tumour perfusion, even in small animals, and the monitoring of basic antiangiogenic studies with perfusion parameters shows a higher significance than conventional power Doppler US.