The role of visual attention in dyslexia: Behavioral and neurobiological evidence

Poor phonological processing has typically been considered the main cause of dyslexia. However, visuo‐attentional processing abnormalities have been described as well. The goal of the present study was to determine the involvement of visual attention during fluent reading in children with dyslexia and typical readers. Here, 75 children (8–12 years old; 36 typical readers, 39 children with dyslexia) completed cognitive and reading assessments. Neuroimaging data were acquired while children performed a fluent reading task with (a) a condition where the text remained on the screen (Still) versus (b) a condition in which the letters were being deleted (Deleted). Cognitive assessment data analysis revealed that visual attention, executive functions, and phonological awareness significantly contributed to reading comprehension in both groups. A seed‐to‐voxel functional connectivity analysis was performed on the fluency functional magnetic resonance imaging task. Typical readers showed greater functional connectivity between the dorsal attention network and the left angular gyrus while performing the Still and Deleted reading tasks versus children with dyslexia. Higher connectivity values were associated with higher reading comprehension. The control group showed increased functional connectivity between the ventral attention network and the fronto‐parietal network during the Deleted text condition (compared with the Still condition). Children with dyslexia did not display this pattern. The results suggest that the synchronized activity of executive, visual attention, and reading‐related networks is a pattern of functional integration which children with dyslexia fail to achieve. The present evidence points toward a critical role of visual attention in dyslexia.     

糖尿病大鼠骨代谢变化与立普妥、胰岛素的干预效应

目的:近年细胞培养实验发现他汀类药物可以促进骨形成,采用动物实验观察胰岛素和他汀类药物立普妥对糖尿病大鼠骨代谢的影响,为糖尿病伴骨质疏松的治疗提供实验依据。方法:实验于2005-08/2006-01在大连医科大学病理教研室完成。①实验分组:SD雄性大鼠55只,随机选择10只为空白对照组,余45只经鼠尾静脉注射链尿佐菌素造成糖尿病大鼠模型。其中40只符合造模标准,随机分为糖尿病未治疗组、胰岛素治疗组、立普妥治疗组及胰岛素 立普妥治疗组,每组10只。②实验方法:所有大鼠皆给予相同普通饮食。胰岛素治疗组及胰岛素 立普妥治疗组于实验第4天接受中效胰岛素治疗,6～8U/d分两次颈背部皮下注射。胰岛素剂量按每只鼠每周血糖进行调整。立普妥治疗组及胰岛素 立普妥治疗组于实验第4天给予立普妥1.25mg/kg灌胃。糖尿病未治疗组和空白对照组给予等量生理盐水灌胃。③实验评估:9周末用乙醚麻醉,每组取4只大鼠去眼球取血之后处死。14周末应用同样方法处死剩余大鼠。均取腰椎骨,常规脱钙石蜡包埋,行苏木精-伊红染色。骨组织形态计量学测量平均骨小梁厚度和平均骨小梁间距或弥散度。血中Ⅰ型胶原氨基端肽测定采用竞争性放射免疫检测方法(碘标记)。结果:实验期间大鼠死亡5只,其中糖尿病未治疗组1只于第3周死亡,胰岛素组2只于第6周死亡,胰岛素 立普妥治疗组2只于第7周死亡。①骨组织病理形态学变化:9周末立普妥治疗组、胰岛素 立普妥治疗组及糖尿病未治疗组光镜下见骨质疏松表现。14周末立普妥治疗组及胰岛素治疗组骨组织微观结构恢复至空白对照组水平。②平均骨小梁厚度:9周末:糖尿病未治疗组、胰岛素治疗组、立普妥治疗组及胰岛素 立普妥治疗组均明显低于空白对照组(P<0.01)。14周末:糖尿病未治疗组及胰岛素 立普妥治疗组均明显低于空白对照组(P<0.05)。③平均骨小梁间距或弥散度:9周末:糖尿病未治疗组及胰岛素 立普妥治疗组均明显高于空白对照组(P<0.05)。14周末:糖尿病未治疗组及胰岛素 立普妥治疗组均明显高于空白对照组(P<0.05)。④Ⅰ型胶原氨基端肽水平:9周末:立普妥治疗组和胰岛素 立普妥治疗组均明显高于空白对照组(P<0.01)。14周末:胰岛素治疗组、立普妥治疗组和胰岛素 立普妥治疗组均明显高于空白对照组(P<0.01)。结论:①糖尿病大鼠造模9周出现明显的骨质疏松。②糖尿病大鼠骨质变化表现为骨吸收超过骨形成作用,主要以骨吸收增强为主。③立普妥及胰岛素可以促进糖尿病大鼠骨质的形成,抑制糖尿病大鼠骨质疏松的发生发展。     

Diabetes Patients' Experiences With the Implementation of Insulin Therapy and Their Perceptions of Computer-Assisted Self-Management Systems for Insulin Therapy

Background

Computer-assisted decision support is an emerging modality to assist patients with type 2 diabetes mellitus (T2DM) in insulin self-titration (ie, self-adjusting insulin dose according to daily blood glucose levels). Computer-assisted insulin self-titration systems mainly focus on helping patients overcome barriers related to the cognitive components of insulin titration. Yet other (eg, psychological or physical) barriers could still impede effective use of such systems.

Objective

Our primary aim was to identify experiences with and barriers to self-monitoring of blood glucose, insulin injection, and insulin titration among patients with T2DM. Our research team developed a computer-assisted insulin self-titration system, called PANDIT. The secondary aim of this study was to evaluate patients’ perceptions of computer-assisted insulin self-titration. We included patients who used PANDIT in a 4-week pilot study as well as patients who had never used such a system.

Methods

In-depth, semi-structured interviews were conducted individually with patients on insulin therapy who were randomly recruited from a university hospital and surrounding general practices in the Netherlands. The interviews were transcribed verbatim and analyzed qualitatively. To classify the textual remarks, we created a codebook during the analysis, in a bottom-up and iterative fashion. To support examination of the final coded data, we used three theories from the field of health psychology and the integrated model of user satisfaction and technology acceptance by Wixom and Todd.

Results

When starting insulin therapy, some patients feared a lifelong commitment to insulin therapy and disease progression. Also, many barriers arose when implementing insulin therapy (eg, some patients were embarrassed to inject insulin in public). Furthermore, patients had difficulties increasing the insulin dose because they fear hypoglycemia, they associate higher insulin doses with disease progression, and some were ignorant of treatment targets. Patients who never used a computer-assisted insulin self-titration system felt they had enough knowledge to know when their insulin should be adjusted, but still believed that the system advice would be useful to confirm their reasoning. Furthermore, the time and effort saved with automated insulin advice was considered an advantage. Patients who had used PANDIT found the system useful if their glycemic regulation improved. Nevertheless, for some patients, the absence of personal contact with their caregiver was a drawback. While guidelines state that adjustment of basal insulin dose based on fasting plasma glucose values is sufficient, both patients who had and those who had not used PANDIT felt that such a system should take more patient data into consideration, such as lifestyle and diet factors.

Conclusions

Patients encounter multiple obstacles when implementing insulin therapy. Computer-assisted insulin self-titration can increase patient awareness of treatment targets and increase their confidence in self-adjusting the insulin dose. Nevertheless, some barriers may still exist when using computer-assisted titration systems and these systems could also introduce new barriers.     

Serum concentrations of oestradiol-17beta, progesterone, relaxin and chorionic gonadotrophin during blastocyst implantation in natural pregnancy cycle and in embryo transfer cycle in the rhesus monkey

The present study was undertaken to assess the temporal association between the profiles of serum concentrations of oestradiol-17beta, progesterone, chorionic gonadotrophin (CG) and relaxin in pregnancies established naturally, and after embryo transfer, as well as in failed pregnancies in rhesus monkeys. In naturally mated cycles (group 1) a conception rate of 75% was obtained. In group 1, the mean day of CG detection in serum was 11.5 +/- 1.9 day post-ovulation, and for relaxin, 9.0 +/- 2.5 day post-ovulation. In group 2, embryo transfer to synchronous, non-mated surrogate recipients was performed; seven embryo transfer cycles yielded three pregnancies which were allowed to continue to term and normal infants were delivered. In embryo transfer cycles the mean day of CG detection was 14.8 +/- 1.8 day post- ovulation, and for relaxin, 11.4 +/- 2.6 day post-ovulation. A delay of about 3 days was observed in the appearance in circulation of CG (P < 0.05) and also of relaxin (P < 0.05) between natural mated and embryo transfer conception cycles. Significant differences (P < 0.05 for progesterone and P < 0.03 for oestradiol) were obtained for the areas under the curves for progesterone and oestradiol between days 12 and 16 in conception cycles compared with failed pregnancies. These data provide the first observation of the normal hormonal signals associated with maternal recognition of transferred embryos during the peri- implantation period, and suggest that the use of such an experimental primate embryo transfer model may help to elucidate components of maternal and embryonic signal-response mechanisms during embryo implantation.      

Plasma amino acid and protein concentrations in infants fed human milk or a whey protein hydrolysate formula during the first month of life

The aim of the study was to compare growth parameters, biochemical indices of protein metabolism and plasma amino acid concentrations in infants fed either human milk ( n = 12) or a whey protein hydrolysate formula ( n = 13) during the first month of life. Growth and gain in skin fold thickness were similar in both groups whereas serum protein concentration was significantly decreased (57.4 ± 3.9 versus 61.2 ± 2.9 g/l) in the infants fed the whey hydrolysate formula. The discrepancies between the plasma amino acid pattern of the whey hydrolysate formula group and that of the human milk group lessened during the first month. Nevertheless, at a mean age of 33 days the plasma threonine concentration remained twice as high and the plasma tyrosine, phenylalanine and proline concentrations were Significantly lower in the whey hydrolysate formula group than in the human milk group. Thus, compared with breast-fed infants, growth and most of the biological indices of protein metabolism were satisfactory in infants fed during the first month of life on a whey protein hydrolysate formula. Nevertheless, the decrease in total plasma protein concentration needs to be confirmed in a larger cohort of infants. In addition, further research is necessary to investigate the possible ways of reducing the hyperthreoninemia and preventing other plasma amino acid disturbances since it would be desirable to obtain plasma amino acid levels similar to those of breast-fed infants.     

Red blood cell fatty acid composition in low-birth-weight infants fed either human milk or formula during the first months of life

The fatty acid composition of red blood cell (RBC) phospholipids in low-birth-weight infants was determined immediately after delivery and during the first 3 months of life. In the first study, infants were fed either human milk or two formulas with different fatty acid compositions but no long chain polyunsaturated fatty acids (LCPUFA). Both groups of formula-fed infants had significantly lower levels of docosahexaenoic acid (DHA) in RBC phospholipids compared with breast-fed infants. RBC phospholipid DHA was similar in the two formula groups at all ages. In the second study, infants received either a non-supplemented or a LCPUFA-supplemented formula. DHA remained stable in RBC phospholipids of infants supplemented with LCPUFA, whereas DHA decreased in RBC phospholipids of unsupplemented infants. These results confirm that adding DHA to formulas is more effective than increasing 18:3 n-3 content, in maintaining RBC phospholipid DHA levels.