Peripheral quantitative computed tomography in children and adolescents: the 2007 ISCD Pediatric Official Positions

Peripheral quantitative computed tomography (pQCT) has mainly been used as a research tool in children. To evaluate the clinical utility of pQCT and formulate recommendations for its use in children, the International Society of Clinical Densitometry (ISCD) convened a task force to review the literature and propose areas of consensus and future research. The types of pQCT technology available, the clinical application of pQCT for bone health assessment in children, the important elements to be included in a pQCT report, and quality control monitoring techniques were evaluated. The review revealed a lack of standardization of pQCT techniques, and a paucity of data regarding differences between pQCT manufacturers, models and software versions and their impact in pediatric assessment. Measurement sites varied across studies. Adequate reference data, a critical element for interpretation of pQCT results, were entirely lacking, although some comparative data on healthy children were available. The elements of the pQCT clinical report and quality control procedures are similar to those recommended for dual-energy X-ray absorptiometry. Future research is needed to establish evidence-based criteria for the selection of the measurement site, scan acquisition and analysis parameters, and outcome measures. Reference data that sufficiently characterize the normal range of variability in the population also need to be established.     

Determination of the 5-HT receptor subtype involved in 8-OH-DPAT-induced hyperlocomotion: potential difficulties arising from inadequate pharmacological tools

Selective 5-HT1A receptor agonists such as 8-OH-DPAT (8-hydroxy-2-(di-n-propylamino)tetralin), flesinoxan, 5-methylurapidil and others, increased locomotor behaviour in rats following s.c. injection. Unfortunately, all available 5-HT1A receptor antagonists are non-selective, a fact which severely hampers their use. The inhibitory effects of (+)- and (-)-pindolol (1-10 mg/kg, -45 min s.c.) on locomotion induced by 8-OH-DPAT were investigated in rats pretreated with the beta-adrenoceptor antagonists, ICI 118,551 and betaxolol (both 1 mg/kg, -45 min s.c.). ICI 118,551 and betaxolol significantly enhanced the response to 8-OH-DPAT. Co-administration of (-)-pindolol (2-10 mg/kg) dose dependently antagonised the hyperlocomotion whereas (+)-pindolol was weakly effective at 10 mg/kg. The partial agonists ipsapirone (1-10 mg/kg, -45 min s.c.) and buspirone (0.1-1 mg/kg, -45 min) antagonised the effects of 8-OH-DPAT. This inhibition may, however, be due to alpha 1-adrenoceptor blockade and DA receptor antagonism, respectively. Finally, although spiroxatrine (0.1 and 1 mg/kg, -45 min s.c.) inhibited the response to 8-OH-DPAT, this inhibition may also be non-specific since spiroxatrine strongly reduced spontaneous locomotor activity. In conclusion, whilst much of our data is consistent with 8-OH-DPAT-induced locomotion being mediated by 5-HT1A receptors, only the data obtained with the pindolol enantiomers provide direct evidence for this. The results also suggest that, under normal circumstances, the 5-HT1A receptor antagonist effect of pindolol may be masked by the facilitating effect of beta-adrenoceptor blockade.     

Assessment of spinal cord ischemia by means of evoked potential monitoring during thoracoabdominal aortic surgery

Besides renal failure and mesenteric infarction, spinal cord ischemia is the most dreaded complication after thoracoabdominal aortic surgery. Several techniques have been developed to improve neurologic outcome of these massive surgical procedures, including pharmacologic adjuncts, epidural cooling, distal aortic perfusion, cerebrospinal fluid drainage, and reattachment of segmental arteries. The authors developed a technique to assess spinal cord integrity as part of the surgical protocol, dictating operative strategies to restore blood supply to the endangered grey matter. Monitoring motor evoked potentials (MEPs) was performed in experimental studies and in 170 patients with a thoracoabdominal aortic aneurysm. The surgical protocol included left heart bypass and cerebrospinal fluid drainage, and MEP monitoring was applied to identify critical intercostal and lumbar arteries. Based on MEPs, the aggressive surgical approach resulted in a significant reduction of neurologic complications (2.3%).     

Asthma severity in children and the quality of life of their parents

This study examines the effect of asthma severity of children aged 7–17 years and sociodemographic characteristics on the caregiver's quality of life. For parents of asthmatic children, there was a negative correlation between overall asthma severity and quality-of-life score. Measuring parental quality of life enables the development of effective asthma programs.