Evaluación de seis fórmulas usadas para el cálculo de la superficie corporal

Antecedentes: La superficie corporal es unavariable antropométrica que se obtiene aplicandofórmulas basadas en el peso y en la talla.Algunas fórmulas se han diseñado para aplicarsementalmente o con calculadoras de bolsillo, perola exactitud de estas fórmulas «fáciles» no seha evaluado sistemáticamente.Objetivos: evaluar la correlación de cincofórmulas «fáciles» con la fórmula de Boyd, yproponer una fórmula nueva basada solo en latalla, desarrollada por uno de los autores(Rincón).Material y métodos: se tomaron 518 datos depeso y talla de las tablas de crecimiento delNational Center for Health Statistics (NCHS).Todos los datos se procesaron con MicrosoftExcel®. Se realizo una regresión lineal con cadauna de las fórmulas para encontrar el coeficientede correlación (r), coeficiente de determinación(r2), pendiente de la recta (m), intersección dela recta (b), y valor p.Resultados. Se consideraron fórmulas adecuadasaquellas con r ³ 0.99, r2³ 0.98, m = 1 ± 0.10,b = 0 ± 0.05 y valor p and lt; 0.05. Cuatro de lasseis fórmulas evaluadas cumplen con loscriterios de selección, entre ellas la nuevafórmula propuesta.Conclusiones. La superficie corporal debeobtenerse en lo posible con fórmulas que utilicenpeso y talla, pero en los casos en los quealguno de estos datos no esté disponible, se puedeacudir a la fórmula correspondiente

Endothelin receptor antagonists for the treatment of pulmonary artery hypertension

AbstractAimsThe demonstration that endothelin production is upregulated in pulmonary artery hypertension (PAH) served as the rationale for developing endothelin-receptor antagonists (ERAs) as a treatment for PAH. This article reviews the primary studies demonstrating efficacy of ERAs in PAH.Main methodsMulticenter, placebo-controlled trials and open-label extension studies.Key findingsTwo orally active ERAs are currently approved for the treatment of PAH — the dual receptor antagonist bosentan, and the more selective ETA receptor antagonist ambrisentan-based on multicenter randomized clinical trials demonstrating efficacy and safety. Long-term experience with both agents supports maintenance of therapeutic effects in most patients. Adverse effects, including altered liver function and edema may occur and require careful monitoring.SignificanceDespite failure to demonstrate efficacy of ERAs in other cardiopulmonary conditions, ERAs have a major role in the treatment algorithm for PAH

Serum L-arginine and Dimethylarginine Levels in Migraine Patients with Brain White Matter Lesions

Background/Aim Migraine is a risk factor for the formation of silent brain white matter lesions (WMLs) that are possibly ischemic in nature. Although dysfunction of the L-arginine/nitric oxide (NO) pathway has been associated with oxidative stress and endothelial dysfunction in migraine, its role in WML development has not been specifically investigated. Thus, this prospective study aimed to measure the serum concentrations of the NO substrate L-arginine, the NO synthase inhibitor asymmetric dimethylarginine (ADMA), and the L-arginine transport regulator symmetric dimethylarginine (SDMA) in migraine patients in a headache-free period. Methods All participants underwent MR imaging to assess for the presence of WMLs on fluid-attenuated inversion recovery imaging. Altogether 109 migraine patients (43 with lesions, 66 without lesions) and 46 control individuals were studied. High-performance liquid chromatography was used to quantify L-arginine, ADMA and SDMA serum concentrations. Migraine characteristics were investigated, and participants were screened for risk factors that can lead to elevated serum ADMA levels independent of migraine. Results Migraine patients and controls did not differ in regard to vascular risk factors. Migraineurs with WMLs had a longer disease duration ( p &lt; 0.001) and a higher number of lifetime headache attacks ( p = 0.005) than lesion-free patients. Higher L-arginine serum levels were found in both migraine subgroups compared to controls ( p &lt; 0.001). Migraine patients with WMLs showed higher ADMA concentrations than lesion-free patients and controls ( p &lt; 0.001, for both). In migraineurs, the presence of WMLs, aura and increasing age proved to be significant predictors of increased ADMA levels ( p = 0.008, 0.047 and 0.012, respectively). SDMA serum levels of lesional migraineurs were higher than in nonlesional patients ( p &lt; 0.001). The presence of lesions and increasing age indicated an increased SDMA level ( p = 0.017 and 0.001, respectively). Binary logistic regression analysis showed that ADMA level ( p = 0.006), increasing age ( p = 0.017) and the total number of lifetime migraine attacks ( p = 0.026) were associated with an increased likelihood of exhibiting WMLs. There was no significant effect of age on ADMA and SDMA concentrations in controls. Conclusions Elevated ADMA levels may impact the pathogenesis of migraine-related WMLs by influencing cerebrovascular autoregulation and vasomotor reactivity. Higher SDMA concentrations may indirectly influence NO synthesis by reducing substrate availability. Elevated L-arginine serum levels might reflect an increased demand for NO synthesis. </jats:sec

Targeted analysis of four breeds narrows equine Multiple Congenital Ocular Anomalies locus to 208 kilobases

The syndrome Multiple Congenital Ocular Anomalies (MCOA) is the collective name ascribed to heritable congenital eye defects in horses. Individuals homozygous for the disease allele (MCOA phenotype) have a wide range of eye anomalies, while heterozygous horses (Cyst phenotype) predominantly have cysts that originate from the temporal ciliary body, iris, and/or peripheral retina. MCOA syndrome is highly prevalent in the Rocky Mountain Horse but the disease is not limited to this breed. Affected horses most often have a Silver coat color; however, a pleiotropic link between these phenotypes is yet to be proven. Locating and possibly isolating these traits would provide invaluable knowledge to scientists and breeders. This would favor maintenance of a desirable coat color while addressing the health concerns of the affected breeds, and would also provide insight into the genetic basis of the disease. Identical-by-descent mapping was used to narrow the previous 4.6-Mb region to a 264-kb interval for the MCOA locus. One haplotype common to four breeds showed complete association to the disease (Cyst phenotype, n = 246; MCOA phenotype, n = 83). Candidate genes from the interval, SMARCC2 and IKZF4, were screened for polymorphisms and genotyped, and segregation analysis allowed the MCOA syndrome region to be shortened to 208 kb. This interval also harbors PMEL17, the gene causative for Silver coat color. However, by shortening the MCOA locus by a factor of 20, 176 other genes have been unlinked from the disease and only 15 genes remain

Risk factors for hospitalization among adults with asthma: the influence of sociodemographic factors and asthma severity

BACKGROUND: The morbidity and mortality from asthma have markedly increased since the late 1970s. The hospitalization rate, an important marker of asthma severity, remains substantial. METHODS: In adults with health care access, we prospectively studied 242 with asthma, aged 18–50 years, recruited from a random sample of allergy and pulmonary physician practices in Northern California to identify risk factors for subsequent hospitalization. RESULTS: Thirty-nine subjects (16%) reported hospitalization for asthma during the 18-month follow-up period. On controlling for asthma severity in multiple logistic regression analysis, non-white race (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.1–8.8) and lower income (OR, 1.1 per $10,000 decrement; 95$10,000 decrement; 95% CI, 1.02–1.4). CONCLUSION: In adult asthmatics with access to health care, non-white race, low income, and greater asthma severity were associated with a higher risk of hospitalization. Targeted interventions applied to high-risk asthma patients may reduce asthma morbidity and mortality

Spontaneous and Template-Directed Emergence of Low-Symmetry Foldamers from Dynamic Homomeric Sequences

Creating large objects from simple subunits rarely results in structures that are of low symmetry as well as of low polydispersity. We now report the spontaneous and uniquely selective oligomerization of simple monomer units into oligomers that are of uniform length, have complex low symmetry structures and are conformationally well-defined. The occurrence of such structures is both frequent and diverse. It is driven by the spontaneous folding into three-dimensional shapes akin to those exhibited by biopolymers. We also show that templates can direct the formation of new functional foldamers. The resulting structures carry imprints of the templates and are therefore capable of binding these. This behavior resembles that of molecularly imprinted polymers (MIPs), with the important distinction that the selected oligomers are uniform and conformationally well-defined, whereas MIPs suffer from heterogeneity in structure, shape and size

Bi-exponential diffusion signal decay in normal appearing white matter of multiple sclerosis.

PURPOSE Our aim was to characterize bi-exponential diffusion signal changes in normal appearing white matter of multiple sclerosis (MS) patients. METHODS Diffusion parameters were measured using mono-exponential (0-1000 s/mm(2)) and bi-exponential (0-5000 s/mm(2)) approaches from 14 relapsing-remitting subtype of MS patients and 14 age- and sex-matched controls after acquiring diffusion-weighted images on a 3T MRI system. The results were analyzed using parametric or nonparametric tests and multiple linear regression models. RESULTS Mono-exponential apparent diffusion coefficient (ADC) slightly increased in controls (P=.09), but decreased significantly in MS as a function of age, nonetheless an elevated ADC was observed with increasing lesion number in patients. Bi-exponential analyses showed that the increased ADC is the result of decreased relative volume fraction of slow diffusing component (f(s)). However, the fast and slow diffusion components (ADC(f), ADC(s)) did not change as a function of either age in controls or lesion number and age in MS patients. CONCLUSIONS These data demonstrated that the myelin content of the white matter affects diffusion in relapsing-remitting subtype of multiple sclerosis that is possibly a consequence of the shift between different water fractions

Controlling Supramolecular Plasticity through Stoichiometry

In this manuscript we describe how, by taking a systems approach, complex energy landscapes of supramolecular assemblies can be navigated using stoichiometry to control, with remarkable selectivity, which assembly gets populated. The perhaps counterintuitive finding is that it is not necessarily the assembly that, in a one-to-one comparison, is the most stable that wins the competition for common building blocks, even though the system is under thermodynamic control. Instead, an individually less stable assembly may completely dominate the system. This domination is possible when the building block stoichiometry in the system matches the stoichiometry of this specific assembly, allowing the system to maximize binding energy by making a large number of assemblies of moderate stability as opposed to a small number of more stable assemblies. <br /