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.     

Effects of movement imitation training in Parkinson's disease: A virtual reality pilot study

BackgroundHypometria is a clinical motor sign in Parkinson's disease. Its origin likely emerges from basal ganglia dysfunction, leading to an impaired control of inhibitory intracortical motor circuits. Some neurorehabilitation approaches include movement imitation training; besides the effects of motor practice, there might be a benefit due to observation and imitation of un-altered movement patterns. In this sense, virtual reality facilitates the process by customizing motor-patterns to be observed and imitated.ObjectiveTo evaluate the effect of a motor-imitation therapy focused on hypometria in Parkinson's disease using virtual reality.MethodsWe carried out a randomized controlled pilot-study. Sixteen patients were randomly assigned in experimental and control groups. Groups underwent 4-weeks of training based on finger-tapping with the dominant hand, in which imitation was the differential factor (only the experimental group imitated). We evaluated self-paced movement features and cortico-spinal excitability (recruitment curves and silent periods in both hemispheres) before, immediately after, and two weeks after the training period.ResultsMovement amplitude increased significantly after the therapy in the experimental group for the trained and un-trained hands. Motor thresholds and silent periods evaluated with transcranial magnetic stimulation were differently modified by training in the two groups; although the changes in the input–output recruitment were similar.ConclusionsThis pilot study suggests that movement imitation therapy enhances the effect of motor practice in patients with Parkinson's disease; imitation-training might be helpful for reducing hypometria in these patients. These results must be clarified in future larger trials.     

Adenosquamous carcinoma of the colon

Two cases of primary adenosquamous carcinomas of the sigmoid colon and rectum are presented. Clinical features and pathologic findings of both primary and metastatic lesions are reported (including immunohistochemistry and electron microscopy). We emphasize that the presence of a metastatic squamous tumor in a patient with an unknown primary does not exclude the possibility of colonic carcinoma. Comparison with other reports in the American medical literature indicates that these are very aggressive tumors that may have a worse prognosis than the more common form of colonic adenocarcinoma. Furthermore, the squamous component, in particular, may have a greater potential for metastasizing and can do so as an undifferentiated-appearing carcinoma. In view of this, the authors suggest that very poorly differentiated areas within colonic adenocarcinomas should be very carefully evaluated by means of immunoperoxidase stains and/or electron microscopy in an attempt to identify squamous features.     

Understanding the role of foot biomechanics on regional foot orthosis deformation in flatfoot individuals during walking

BackgroundFoot orthoses (FOs) are one of the most common interventions to restore normal foot mechanics in flatfoot individuals. New technologies have made it possible to deliver customized FOs with complex designs for potentially better functionalities. However, translating the individuals’ biomechanical needs into the design of customized FOs is not yet fully understood.Research questionOur objective was to identify whether the deformation of customized FOs is related to foot kinematics and plantar pressure during walking.MethodsThe kinematics of multi-segment foot and FOs contour were recorded together with plantar pressure in 17 flatfoot individuals while walking with customized FOs. The deformation of FOs surface was predicted from its contour kinematics using an artificial neural network. Plantar pressure map and deformation were divided into five anatomically based regions defined by the corresponding foot segments. Forward stepwise linear mixed models were built for each of the four gait phases to determine the feet-FOs interaction.ResultsIt was observed that some associations existed between foot kinematics and pressure with regional FOs deformation. From heel-strike to foot-flat, longitudinal arch angle was associated with FOs deformation in forefoot. From foot-flat to midstance, rearfoot eversion accounted for variation in the deformation of medial FOs regions, and forefoot abduction for the lateral regions. From midstance to heel-off, rearfoot eversion, longitudinal arch angle, and plantar pressure played significant role in deformation. Finally, from heel-off to toe-off, forefoot adduction affected the deformation of forefoot and midfoot.SignificanceThis study provides guidelines for designing customized FOs. Flatfoot individuals with excessive rearfoot eversion or very flexible medial arches require more support on medial FOs regions, while the ones with excessive forefoot abduction need the support on lateral regions. However, a compromise should be made between the level of support and the level of increase in plantar pressure to avoid stress on foot structures.     

Evidence for Kidney Rejection After Combined Bone Marrow and Renal Transplantation Despite Ongoing Whole‐Blood Chimerism in Rhesus Macaques

Although there is evidence linking hematopoietic chimerism induction and solid organ transplant tolerance, the mechanistic requirements for chimerism‐induced tolerance are not clearly elucidated. To address this, we used an MHC‐defined primate model to determine the impact of impermanent, T cell‐poor, mixed‐chimerism on renal allograft survival. We compared two cohorts: one receiving a bone marrow and renal transplant (“BMT/renal”) and one receiving only a renal transplant. Both cohorts received maintenance immunosuppression with CD28/CD40‐directed costimulation blockade and sirolimus. As previously demonstrated, this transplant strategy consistently induced compartmentalized donor chimerism, (significant whole‐blood chimerism, lacking T cell chimerism). This chimerism was not sufficient to prolong renal allograft acceptance: the BMT/renal mean survival time (MST, 76 days) was not significantly different than the renal transplant alone MST (85 days, p = 0.46), with histopathology documenting T cell mediated rejection. Flow cytometric analysis revealed significant enrichment for CD28–/CD95+ CD4+ and CD8+ Tem cells in the rejected kidney, suggesting a link between CD28‐negative Tem and costimulation blockade‐resistant rejection. These results suggest that in some settings, transient T cell‐poor chimerism is not sufficient to induce tolerance to a concurrently placed renal allograft and that the presence of this chimerism per se is not an independent biomarker to identify tolerance.     

颅内神经元及混合性神经元-神经胶质肿瘤的MRI诊断

目的:探讨颅内神经元及混合性神经元-神经胶质肿瘤的MRI表现特征,以提高对其认识和诊断水平。方法:复习22例经手术病理证实的神经元及混合性神经元-神经胶质肿瘤的临床和影像资料,结合文献分析其MRI表现特征。结果:5例中枢神经细胞瘤均位于侧脑室内,呈不均匀长T1、长T2信号和不均匀强化;1例神经节细胞瘤位于颞叶,呈长T1、长T2信号,无瘤周水肿和强化;12例神经节细胞胶质瘤中,6例在颞叶,5例为囊性并有强化壁结节;2例胚胎发育不良性神经上皮肿瘤均位于颞叶皮质,呈不均匀长T1、长T2信号,无瘤周水肿和强化;1例婴儿促纤维增生性神经节细胞胶质瘤位于颞叶皮质,为不均匀长T1和一致性长T2信号,无瘤周水肿,呈环状强化;1例乳头状胶质神经元肿瘤在颞叶,呈囊性并有不规则壁结节,其囊壁和壁结节发生强化。结论:MRI检查,不同类型的神经元及混合性神经元-神经胶质肿瘤各具其好发部位并多有一定表现特征,结合患者年龄和临床表现,常可做出倾向性诊断。     

好氧同时硝化-反硝化脱氮微生物的混合培养

筛选和分离得到的多株脱氮微生物 ,能在完全好氧条件下将氨氮转化为NO2 - ,随即在好氧反硝化菌的作用下还原为N2 排放 ,整个生物脱氮过程历时较短 ,30h内对 2 0 0mg/L的氨氮去除率达 99% ,而且无中间产物NO2 - 的积累 .混合脱氮微生物菌群生长的适宜 pH范围为 7～ 10 ,探索实现混合脱氮微生物菌群高密度培养的 pH :发酵前期补酸控制 pH≤ 8,发酵中后期不控制 pH值 ,可缩短菌体的生长周期 ,提高菌体的氨氮降解速率 ,细胞质量浓度达 3.9g/L ,比自然 pH条件下提高了 6 2 .5 % .     

碳、氮源对PVA降解混合体系降解能力的影响及PVA降解机理初探

以能完全降解1g／LPVA的一个混合体系为研究对象，研究了碳、氮源对该混合体系降解PVA的影响。实验表明，补充有机氮源有利于混合体系菌体的生长，并且能提高混合体系对PVA的降解能力。进一步的研究发现，其它碳源的补充有利于菌体的生长，但对混合体系降解PVA产生一定的抑制作用。根据初步研究结果推断，该混合体系所产的PVA降解酶主要结合在细胞膜上，部分PVA进入细胞后被降解。     

双相情感障碍混合相临床特征对照研究

目的:了解双相情感障碍混合相的临床特征。方法:收集42例双相情感障碍混合相患者(混合组)与93例无混合发作的双相情感障碍躁狂相的患者(躁狂组)住院治疗的临床资料进行对比。结果:混合组年龄稍低,多见于女性和独身者,性格多为外向型或中间型,首次发作多为抑郁,多伴有精神病性症状及自杀意念和企图。多元逐步回归分析提示,混合发作与自杀意念和企图、性格、性别、首次发作形式有显著的相关性。混合组具有易被误诊、住院时间长、疗效较差的特点。结论:双相情感障碍混合相临床表现具有特殊性、严重性及相应的难治性,应加强重视。