Promoting safe infant feeding practices – the importance of structural,social and contextual factors in Southern Africa

There has been significant progress towards the goal of eliminating vertical transmission of HIV by 2015. However, a question that remains is how we can most effectively prevent late postnatal transmission of HIV through infant feeding. Guidelines published by the World Health Organization in 2010 have been widely adopted. These guidelines place strong emphasis on exclusive breastfeeding, in some countries over‐turning a prior emphasis on formula feeding. Where available, provision of antiretroviral treatment for HIV‐positive mothers or prophylaxis for infants offers additional protection against vertical transmission through infant feeding. However, merely changing guidelines is not sufficient to change practice, particularly with regard to culturally sanctioned forms of feeding, such as mixed feeding. This commentary highlights structural, social and contextual barriers to effective implementation of the guidelines and suggests ways to address some of these barriers.     

Accuracy of the Common Predictive Equations for Estimating Resting Energy Expenditure among Normal and Overweight Girl University Students

Objective: The aim of the present study was to determine the accuracy of commonly used predictive formulas of resting metabolic rate (RMR) compared to measured RMR in normal and overweight young females.

Methods: In this cross-sectional study, 98 female university students aged 18–30 years with body mass index 18 to 30 kg/m² were recruited. Anthropometric indices and body compositions were measured. RMR was measured by indirect calorimetry (FitMate, Cosmed, Rome, Italy) and estimated by 11 predictive formulas. The accuracy of the RMR formulas and mean percentage differences between estimated and measured values were calculated. Paired t test was used to compare estimated and measured RMRs.

Result: There were no significant differences between measured and estimated RMR by the 4 commonly used formulas (Mifflin, Cunningham, and World Health Organization [WHO]/Food and Agriculture Organization [FAO]). Among all of the equations, the Mifflin formula showed the lowest bias (?2.97 ± 116.43 kcal/day) at the group level and was the most accurate formula (80.23%) in normal and overweight participants. The over- and underestimated values were about 14% and 5.5%, respectively. In normal and overweight females, Mifflin was the most accurate formula, with 75.51% and 84.61% accuracy, respectively.

Conclusion: Given the current lack of a standardized formula that consistently delivers accurate results, the Mifflin formula can be recommended for estimating energy requirements in normal and overweight females in clinical practice.     

Leonardo da Vinci's “A Skull Sectioned”: Skull and dental formula revisited

What can be learned from historical anatomical drawings and how to incorporate these drawings into anatomical teaching? The drawing “A skull sectioned” (RL 19058v) by Leonardo da Vinci (1452–1519), hides more detailed information than reported earlier. A well‐chosen section cut explores sectioned paranasal sinuses and ductus nasolacrimalis. A dissected lateral wall of the maxilla is also present. Furthermore, at the level of the foramen mentale, the drawing displays compact and spongious bony components, together with a cross‐section through the foramen mentale and its connection with the canalis mandibulae. Leonardo was the first to describe a correct dental formula (6424) and made efforts to place this formula above the related dental elements. However, taking into account, the morphological features of the individual elements of the maxilla, it can be suggested that Leonardo sketched a “peculiar dental element” on the position of the right maxillary premolar in the dental sketch. The fact that the author did not make any comment on that special element is remarkable. Leonardo could have had sufficient knowledge of the precise morphology of maxillary and mandibular premolars, since the author depicted these elements in the dissected skull. The fact that the author also had access to premolars in situ corroborates our suggestion that “something went wrong” in this part of the drawing. The present study shows that historical anatomical drawings are very useful for interactive learning of detailed anatomy for students in medicine and dentistry. Clin. Anat., 2013. © 2012 Wiley Periodicals, Inc.     

经典名方小续命汤的历史沿革及临床应用考证

国家中医药管理局颁布的《古代经典名方目录（第一批）》中小续命汤出自《备急千金要方》卷八·诸风，该文对小续命汤来源的追溯、历史发展、变化的进程及临床应用均进行系统的考证。考证结果表明，续命汤及其类方是唐宋以前治疗中风的主要方剂，延绵七八百年，为治风准绳，其中以小续命汤最具代表性。小续命汤由续命汤衍变而来，方名最早出现于东晋《小品方》，唐代孙思邈将其纳入《备急千金要方》，对其治疗中风的疗效推崇备至，曰“诸风服之皆验”，后经《外台秘要》及多部医著记载，被列为治疗中风第一要方。宋以后，随着医家对中风病机认识的变化及对小续命汤认识的局限性导致其在中风证的临床应用中逐渐减少，近现代以来又被重新认知和应用，期间其临床应用也发生了较大的变迁。其临床应用范围广泛，涉及多种脑部及神经系统相关疾病，包括但不限于①脑卒中及其后遗症，②周围性面瘫，③类风湿关节炎，④高血压，⑤其他运动神经系统疾病等。主治为脑卒中及其后遗症，其次为周围性面瘫，还有其他新的适应证正逐渐被发现，以上为小续命汤的临床定位、新药转化研究提供有效性安全性的参考依据。     

Asymptotic accuracy of Bayesian estimation for a single latent variable

In data science and machine learning, hierarchical parametric models, such as mixture models, are often used. They contain two kinds of variables: observable variables, which represent the parts of the data that can be directly measured, and latent variables, which represent the underlying processes that generate the data. Although there has been an increase in research on the estimation accuracy for observable variables, the theoretical analysis of estimating latent variables has not been thoroughly investigated. In a previous study, we determined the accuracy of a Bayes estimation for the joint probability of the latent variables in a dataset, and we proved that the Bayes method is asymptotically more accurate than the maximum-likelihood method. However, the accuracy of the Bayes estimation for a single latent variable remains unknown. In the present paper, we derive the asymptotic expansions of the error functions, which are defined by the Kullback–Leibler divergence, for two types of single-variable estimations when the statistical regularity is satisfied. Our results indicate that the accuracies of the Bayes and maximum-likelihood methods are asymptotically equivalent and clarify that the Bayes method is only advantageous for multivariable estimations.     

中药配方精油——一种中药入药新形式的思考

饮片是中医临床用药的主体,随着中医用药现代化,中药配方颗粒逐步发展并初具规模。虽有中药注射剂、口服液等的加工形式,但只占中药市场的少部分,并以内服为主。而脂溶性成分口服时,溶出受限,吸收相对较少,且具有刺激胃肠道的副作用,造成患者耐受性低。虽有水提、醇提等加工制成的外用制剂,但多为粗制剂,且剂量随意,在一定程度上造成了脂溶性成分的浪费。而中药的脂溶性成分大多具有较好的生物活性,如五味子乙素、丹参酮、绿原酸甲酯等,但却没有合适的药用形式。若想"药"尽其用,就必须对中药的脂溶性成分进行系统研究,在提取、分离和收集工艺均相当成熟的基础上,研发以脂溶性成分为主的,药理药效确切的,又利于其吸收的药用形式。中药精油具有抗衰老、抗痴呆、抗氧化等多种活性,已广泛应用于临床、药妆、保健品等领域。但单方精油作用有限,配伍既可增强药效、降低毒性,也可扩大精油应用范围。因此,可将中药配方精油作为中药入药新形式,并以外用为主、内服为辅,以弥补中药外用多为粗制剂、剂量随意的不足和内服吸收少、刺激胃肠道的劣势,满足临床用药需求,更快、更准、更好、更强地发挥脂溶性成分的药效。