Energy requirements assessed using the doubly-labelled water method

To investigate the association between social risk factors and access to emergency health services, 333 children, with a medium age of 39.1 months, have been recruited. 31.2% of these children had at least one social risk factor. After 12 months through a phone call we evidentiated that children with social risk showed an access to emergency services about double (relative risk factor more than double) in respect to children with no social risk factors.     

Effects of inhaled nitric oxide and oxygen in high-altitude pulmonary edema

BACKGROUND: High-altitude pulmonary edema (HAPE) is characterized by pulmonary hypertension, increased pulmonary capillary permeability, and hypoxemia. Treatment is limited to descent to lower altitude and administration of oxygen. METHODS AND RESULTS: We studied the acute effects of inhaled nitric oxide (NO), 50% oxygen, and a mixture of NO plus 50% oxygen on hemodynamics and gas exchange in 14 patients with HAPE. Each gas mixture was given in random order for 30 minutes followed by 30 minutes washout with room air. All patients had severe HAPE as judged by Lake Louise score (6.4+/-0.7), PaO2 (35+/-3. 1 mm Hg), and alveolar to arterial oxygen tension difference (AaDO2) (26+/-3 mm Hg). NO had a selective effect on the pulmonary vasculature and did not alter systemic hemodynamics. Compared with room air, pulmonary vascular resistance fell 36% with NO (P<0.001), 23% with oxygen (P<0.001 versus air, P<0.05 versus NO alone), and 54% with NO plus 50% oxygen (P<0.001 versus air, P<0.005 versus oxygen and versus NO). NO alone improved PaO2 (+14%) and AaDO2 (-31%). Compared with 50% oxygen alone, NO plus 50% oxygen had a greater effect on AaDO2 (-18%) and PaO2 (+21%). CONCLUSIONS: Inhaled NO may have a therapeutic role in the management of HAPE. The combined use of inhaled NO and oxygen has additive effects on pulmonary hemodynamics and even greater effects on gas exchange. These findings indicate that oxygen and NO may act on separate but interactive mechanisms in the pulmonary vasculature.     

Objective markers of condom failure

RATIONALE AND OBJECTIVES: The authors compare the magnetic resonance (MR) phase contrast flow velocity measurements in varying concentric stenoses with invasive measurements obtained with a Doppler guidewire. METHODS: Flow velocity measurements were obtained using a calibrated 0.018 inch 12 MHz Doppler guidewire and a 1.0 T MR imaging system in a pulsatile hydraulic model with variable arterial stenoses. Velocity measurements were performed proximal, intrastenotic, and distal to the stenoses. The cross-sectional area of stenosis was calculated from the data of both methods. For MR imaging measurements, fast low-angle shot two-dimensional phase contrast sequences with different velocity encodings were used. RESULTS: Phase contrast flow measurements correlated well (r = 0.95, Pearson) with Doppler guidewire-based flow velocity data. Generally, flow velocities obtained with MR imaging were lower when compared with the Doppler-based data (P < or = 0.001, Wilcoxon matched pairs test). However, the ratios and the calculated cross-sectional area of stenoses showed a high correlation (r = 0.96) with the predefined area of stenoses. CONCLUSIONS: The assessment of flow alterations in vitro due to variable stenoses using MR phase contrast flow measurements is very well correlated with the Doppler guidewire. Consequently, these results required in vivo measurements of atherosclerotic lesions to evaluate the clinical impact.     

Co-morbidity and familial aggregation of alcoholism and anxiety disorders

BACKGROUND: This study examined the patterns of familial aggregation and co-morbidity of alcoholism and anxiety disorders in the relatives of 165 probands selected for alcoholism and/or anxiety disorders compared to those of 61 unaffected controls. METHODS: Probands were either selected from treatment settings or at random from the community. DSM-III-R diagnoses were obtained for all probands and their 1053 first-degree relatives, based on direct interview or family history information. RESULTS: The findings indicate that: (1) alcoholism was associated with anxiety disorders in the relatives, particularly among females; (2) both alcoholism and anxiety disorders were highly familial; (3) the familial aggregation of alcoholism was attributable to alcohol dependence rather than to alcohol abuse, particularly among male relatives; and (4) the the pattern of co-aggregation of alcohol dependence and anxiety disorders in families differed according to the subtype of anxiety disorder; there was evidence of a partly shared diathesis underlying panic and alcoholism, whereas social phobia and alcoholism tended to aggregate independently. CONCLUSIONS: The finding that the onset of social phobia tended to precede that of alcoholism, when taken together with the independence of familial aggregation of social phobia and alcoholism support a self-medication hypothesis as the explanation for the co-occurrence of social phobia and alcoholism. In contrast, the lack of a systematic pattern in the order of onset of panic and alcoholism among subjects with both disorders as well as evidence for shared underlying familial risk factors suggests that co-morbidity between panic disorder and alcoholism is not a consequence of self-medication of panic symptoms. The results of this study emphasize the importance of examining co-morbid disorders and subtypes thereof in identifying sources of heterogeneity in the pathogenesis of alcoholism.     

Neuromodulators enhance transmitter release by two separate mechanisms at the inhibitor of crayfish opener muscle

A presynaptic voltage control method has been used to investigate the modulatory effects of serotonin (5-HT) and okadaic acid (OA) on the inhibitory junction of the crayfish opener muscle. Instead of using action potentials, we used 20 msec pulses depolarized to 0 mV to activate transmitter release. This approach allowed us to monitor two separate physiological parameters related to the release process. The first parameter, transmitter release kinetics, is characterized as the delay when inhibitory postsynaptic conductance reaches its half-maximum (IPSG50). The second parameter, the total area of IPSG (IPSGarea), estimates total transmitter output. We have reported previously that the F2 component of synaptic facilitation is associated with a decrease in IPSG50 but without a change in IPSGarea. These results raised the possibility that IPSG50 and IPSGarea could be mediated by separate mechanisms that were modulated independently. To explore this possibility, we investigated the effects of 5-HT (100-200 nM) and OA (2.5 microM) on the two parameters. 5-HT and OA enhanced IPSG neither by changing the sensitivity of postsynaptic receptors, as tested by iontophoretically ejected GABA, nor by elevating resting and action potential-activated presynaptic free calcium, as monitored by fura-2 imaging. 5-HT and OA decreased IPSG50 by 3.0 +/- 1.4 and 3.6 +/- 1.1 msec, respectively, and increased IPSGarea by 50 +/- 21 and 37 +/- 6%, respectively. The ability of F2 facilitation to accelerate release kinetics was reduced in the presence of the modulators, suggesting that the mechanism underlying the accelerated release kinetics was shared by the two modes of synaptic enhancement. This report demonstrates that the acceleration in release kinetics and the increase in total release are two separate mechanisms for enhancing transmitter output and that these two mechanisms can be activated without changes in presynaptic calcium dynamics.     

Cost comparison of immediate angioplasty versus thrombolysis followed by conservative therapy for acute myocardial infarction: a randomized prospective trial. Mayo Coronary Care Unit and Catheterization Laboratory Groups

OBJECTIVE: Immediate angioplasty and thrombolysis followed by conservative therapy are treatment strategies for acute myocardial infarction. The objective of this study was to compare the costs of these two strategies during a 12-month period. METHODS: Of 103 patients with acute myocardial infarction who sought medical assistance within 12 hours after onset of symptoms, 4 were excluded from analysis for various reasons, 51 received tissue plasminogen activator, and 48 underwent immediate angioplasty as the initial revascularization strategy. The main outcome determinants were direct monetary costs and indirect measures of costs, including duration of hospital stay and return to work. RESULTS: No significant difference in monetary costs between the two initial treatment strategies could be demonstrated. A trend was noted toward a briefer hospital stay and fewer late in-hospital procedures for patients treated initially with immediate angioplasty. Other measures of indirect costs were not statistically different. CONCLUSION: The hypothesis that thrombolysis followed by conservative therapy would be more cost-effective than immediate angioplasty in the treatment of patients with acute myocardial infarction could not be substantiated. The two strategies seem to have similar cost-effectiveness.     

Lesion morphology assessed by pre-interventional intravascular ultrasound does not predict the incidence of severe coronary artery dissections

AIMS: Coronary artery dissections are common findings following percutaneous transluminal coronary angioplasty and occur with an incidence of approximately 20% to 40%. The purpose of this study was to evaluate the impact of intravascular ultrasound for the prediction of severe dissections by pre-interventional analysis of lesion morphology and plaque composition. METHODS AND RESULTS: Pre- and post-interventional intravascular ultrasound was performed in 197 patients with 205 lesions. Using intravascular ultrasound criteria, 24 lesions were classified as soft (hypo- or iso-echogenic), 73 as intermediate (hyper-echogenic) and 108 as calcified (calcific arc > 90 degree of the vessel circumference). Additionally, calcium localization was defined as subendothelial, central or deep. The incidence of dissections was 37.5% in patients with soft lesions, 24.7% in patients with intermediate and 36.1% in patients with calcified lesions. In calcified lesions, the occurrence of severe dissections was not dependent on the localization of calcium deposits. The procedural parameters were similar in all patients. The minimal inflation pressure, however, was significantly higher in calcified lesions (P < 0.01). CONCLUSION: Assessment of lesion morphology by intravascular ultrasound cannot predict the occurrence of severe dissections following percutaneous transluminal coronary angioplasty. Furthermore, despite significantly higher inflation pressures in heavily calcified lesions, the incidence of dissections was found to be comparable in all lesions.     

Water does not flow across the tight junctions of MDCK cell epithelium

Although it has been known for decades that the tight junctions of fluid-transporting epithelia are leaky to ions, it has not been possible to determine directly whether significant transjunctional water movement also occurs. An optical microscopic technique was developed for the direct visualization of the flow velocity profiles within the lateral intercellular spaces of a fluid-absorptive, cultured renal epithelium (MDCK) and used to determine the velocity of the fluid flow across the tight junction. The flow velocity within the lateral intercellular spaces fell to near zero adjacent to the tight junction, showing that significant transjunctional flow did not occur, even when transepithelial fluid movement was augmented by imposition of osmotic gradients.     

Parental behaviour is unrelated to experimentally manipulated great tit brood sex ratio

Parental investment may be biased with respect to parental sex or offspring sex or there may be an interaction between parental and offspring sex. We investigated whether any of these types of bias occurred in great tits, Parus major. By sexing chicks using random amplified polymorphic DNA (RAPD) markers and subsequently moving chicks between broods, we were able to manipulate broods early in the nestling period to give all-male, mixed-sex and all-female broods. Provisioning behaviour (total feeding rate, proportion of feeding visits by the male, prey size, visit duration and proportion of visits in which a faecal sac was removed) was measured for broods aged 8-9 and 11-12 days. Nest defence behaviour was measured for 15-day-old broods. Parental weight, the occurrence of second broods and overwinter survival of the parents were also analysed. There were some differences in parental care between the parents: males made the majority of feeding visits and were more vigorous in nest defence. However, there was no evidence that parental care varied in relation to brood sex ratio or that there was an interaction in parental care between parental sex and brood sex ratio. Copyright 1998 The Association for the Study of Animal Behaviour