Comparative reproducibility of the noninvasive ultrasound methods for the assessment of vascular function

The aim of this work was to assess the reproducibility of ultrasound parameters of vascular function, since these measurements are currently recommended by the guidelines for the evaluation of the cardiovascular risk. Twenty subjects (51 ± 17 years, 11 men) had vascular ultrasound (Aloka Prosound α10) performed by two observers, at the level of the right common carotid artery for assessment of intima-media thickness (IMT), “wall tracking”, and “wave-intensity analysis”, and at the level of the right brachial artery for the assessment of flow-mediated dilation (FMD). Wave intensity is a hemodynamic index, evaluating ventriculo-arterial interaction and can be measured in real time by a double-beam ultrasound technique through simultaneous recording of carotid arterial blood flow velocity and diameter. Carotido-femoral pulse wave velocity (PWV) was determined using the Complior method. Intra- and inter-observer reproducibility was assessed during a first session, when three consecutive acquisitions were made (first observer → second observer → first observer); repeatability was evaluated 1 week later (second observer). The most reproducible and repeatable parameters were PWV (intraobserver ±3.3%, interobserver ±2.6%, repeatability ±5.6%) and IMT (±3.7, ±4.3, ±4.9%, respectively). Intraobserver reproducibility for arterial stiffness and ventriculo-arterial coupling parameters was the highest for the beta index (±3.8%), and the lowest for the second systolic peak (±22.4%). Interobserver reproducibility and repeatability varied between very good for the wave speed (±5.5 and ±4.3%), and unsatisfactory for the negative area (±31.8 and ±38.6%). FMD had good reproducibility (intraobserver ±11.6%, interobserver ±8%, repeatability ±7%), whereas augmentation index had only satisfactory results (±17.8, ±8.4, ±23.8%, respectively). Only some parameters of vascular function have good reproducibility and repeatability, better or similar to other ultrasound methods and, therefore, these are ready to be used in routine clinical practice.     

Acute stress reduces blood flow in the orofacial area, in conscious rabbits

In the complex neurovascular control of the orofacial area, the only vasoconstrictor action is mediated by the sympathetic nervous system; however, its functional role is still unclear as little evidence exists of vasoconstrictor responses to physiological stimuli in both animal and human models. Aim of the present study was to investigate, orofacial vascular responses to acute stress in conscious rabbits. Twenty rabbits, implanted with chronic perivascular flow probes on the facial artery and with a telemetric probe for arterial blood pressure, were subjected to different alerting/stress stimuli, i.e., noise, taps on the rabbit's box, air jet, noxious cutaneous stimuli. Smaller groups of animal also underwent electromyographic (EMG) activity recording from the masseter muscle, unilateral section of the cervical sympathetic nerve (n = 8), and alpha-adrenergic blockade with phentolamine (n = 6). On average, all stressors evoked a pressor response accompanied by variable changes in heart rate and induced a marked, short-latency reduction in facial artery blood flow, corresponding to a decrease of 37-50% in vascular conductance of the facial artery. Local sympathetic denervation abolished the short-latency (<15 s) vasoconstrictor response to all stressors and attenuated the late (>15 s) phase of the long-lasting response to the air jet. All vasoconstrictor effects were blocked by phentolamine.Increases in blood flow were observed only in concomitance with masseter EMG activity either during masticatory activity or in the form of brief occasional spontaneous contractions.This study provides evidence of an effective vasoconstrictor control by the sympathetic system in the orofacial area under stress conditions.     

Sleep and epilepsy in neonates

Background and objectiveIn clinical practice, the association between sleep and epilepsy has been increasingly observed in adults and during childhood. The aim of this article is to verify the relationship between sleep and epilepsy in the neonatal period in order to identify evidence and mechanisms to explain how epilepsy or neonatal seizures might disrupt sleep and how sleep might influence seizure occurrence and epilepsy during this age span.MethodsLiterature review with search of PubMed database using the key words neonatal seizures and sleep.Results and conclusionThe complex processes of cortical maturation are closely related to the regulation of sleep–wakefulness cycles. Sleep regulation in the context of neonatal seizures is frequently abnormal, and these alterations may be a result of the maladaptative plasticity of neuronal networks. Furthermore, in this situation altered connectivity might also be associated with other expressions of neurological dysfunction such as cognitive and behavioral problems. EEG background abnormalities and higher frequency of discharges are often associated with disrupted sleep organization. The outcome of newborns with seizures where sleep organization is undifferentiated seems to be more unfavorable.     

Clinical Implications of Adiponectin and Inflammatory Biomarkers in Type 2 Diabetes Mellitus

Objectives: To study the interrelationships of adiponectin, C-reactive protein (CRP) and fibrinogen with each other in T2DM patients with (T2DM-C) and without complications (T2DM-NC) among healthy individuals. Design and methods: The study comprised of 120 T2DM-C, 59 T2DM-NC patients and 40 healthy volunteers. Biochemical markers were determined in the serum. Results: Positivity rates of CRP and fibrinogen were significantly increased in T2DM-C as compared to T2DM-NC or controls, whereas adiponectin showed highest level in healthy individuals. Inflammatory biomarkers were inversely correlated with adiponectin (P < 0.01). Lipid profiles, kidney functions and BMI, showed positive significant correlation with CRP and fibrinogen but negative correlation with adiponectin. For better detection of T2DM, the combined sensitivity (98.9%) and specificity (92.5%) of fibrinogen and adiponectin was higher than the combined sensitivity and specificity of fibrinogen and CRP or adiponectin and CRP or than that of the biomarkers alone. Conclusion: Elevated levels of CRP and fibrinogen and reduced level of adiponectin can be used for early diagnosis of T2DM and can predict diabetic complications.     

Pervasive and Situational Hyperactivity—Confounding Effect of Informant: A Research Note

Several studies of children with problems of hyperactivity, impulsivity, and inattention (HIA) have suggested that when such behaviour occurs in more than one setting, associated conduct problems, emotional symptoms, and functional impairment are more serious than when HIA problems are seen in one situation only. Analyses of parent and teacher reports on a community sample of 480 children aged 7-11 are presented to show that in some cases this conclusion may have resulted from a confound between informant and information. When children with situational HIA were divided into 'home situational' and 'school situational' subgroups, their scores on other measures of psychopathology and impairment varied, depending on whether the informant was the parent or the teacher. When the source of information was independent of parents' or teachers' judgments, no differences were found between situationally and pervasively HIA children. Implications for future studies of situational and prevasive HIA are discussed.     

Reduction of Toxicity of a Vinca Alkaloid by an Anti-Vinca Alkaloid Antibody

Inadvertent oncolytic overdoses occur rarely, but can have serious consequences. We have investigated the possibility of using an antibody, 27.8.1A, reactive with vinca alkaloids, as a means of reducing the toxicity associated with overdose situations. In vitro cytotoxicity of a vinca derivative, 4-desacetyl-vinblastine-3-car-box-hydrazide (DAVLBHYD), with and without the addition of 27.8.1A, was determined. Using CCRF-CEM, a human acute lymphoblastic leukemia cell line, as a target in this assay, we observed a greater than 90% increase in cell viability using 100 μg/ml 27.8.1A with a 0.1 pglml concentration of DAVLBHYD. 27.8.1A had no effect on cell viability when doxorubicin was used as a control drug in this assay. Similarly, the addition of an irrelevant antibody, EGFrL11, had no effect on the toxicity of DAVLBHYD. In an in vivo survival experiment, nude mice were injected with a toxic dose of DAVLBHYD and subsequently given four doses of 27.8.1A. All anti vinca antibody-treated mice survived, in contrast to the untreated group or irrelevant antibody-treated group in which only 25% and 10% of the mice survived, respectively.     

Technical efficiency and economies of diversification in health care

In national health services, where there is a tendency towards a lack of resources and a continuous increase in demand, it is necessary to implement decisions that promote efficiency. In this paper we focus on potential diversification economies as a strategy to increase efficiency levels. We evaluate the change in efficiency in Catalan hospitals between 1987 and 1992, and analyse the presence of possible diversification economies in each hospital. We use Data Envelopment Analysis, which does not need information on either input or output prices. The results are that the majority of hospitals could increase their efficiency and reduce their costs by diversification to the output-mix offered. Potential productivity gains are between 29% and 46%. This revised version was published online in July 2006 with corrections to the Cover Date.