氢质子核磁波谱对儿童热性惊厥脑异常检出和预后评估的价值分析

目的探讨氢质子核磁波谱（H1-MRS）检查对儿童热性惊厥（FS）的脑实质异常的检测效率,及其用于预测临床预后的价值。 方法选择中山市人民医院普通儿科自2017年3月至2018年5月收治的38例FS患儿作为研究对象,所有患儿均进行颅脑MRI及H1-MRS检查,比较MRI和H1-MRS检查对FS患儿颅内异常检出效率差异。根据H1-MRS结果计算代谢物质氮-乙酰天门冬氨酸（NAA）/[肌酸（Cr）+磷酸肌酸（Cho）]、NAA/Cr、NAA/Cho值,然后根据患儿出现临床不良预后情况分为有不良临床预后组和无不良临床预后组,比较2组患儿间NAA/（Cr+Cho）、NAA/Cr、NAA/Cho值差异,并分析其对预后的评估价值。 结果38例FS患儿中,MRI检出颅脑异常情况有23例,H1-MRS检出颅脑异常情况有32例,异常情况检出率比较差异具有统计学意义（χ²=5.330,P=0.021）。13例FS患儿出现不良临床预后,有不良临床预后组患儿中表现为复杂型的比率高于无不良临床预后组,差异有统计学意义（P<0.05）。有不良临床预后组患儿的NAA/（Cr+Cho）、NAA/Cr、NAA/Cho值均小于无不良临床预后组,差异有统计学意义（P<0.05）。绘制NAA/（Cr+Cho）、NAA/Cr、NAA/Cho值对预测不良临床预后ROC曲线,其相应的曲线下面积分别为0.848、0.774、0.797。 结论H1-MRS检查对FS患儿脑实质异常的检出率高于MRI检查,且H1-MRS结果计算所得的NAA/（Cr+Cho）、NAA/Cr、NAA/Cho值在FS患儿中显著降低,其中,NAA/（Cr+Cho）值对患儿的预后具有较好的预测价值。     

Carers’ concern for older people falling at home: an integrative review

Falls, the leading cause of injury and death among older people, can have a significant psychosocial impact on carers. Carers play a crucial role in caring for older persons at home and in fall prevention. This review, which included 15 studies, aimed to identify carers’ concern about older people falling and its impact. We identified that most carers had concerns about repeated falls in older people, unknown consequences of falls and care recipients’ non-adherence to fall prevention advice. These concerns, in turn, affect carers’ physical and psychological health, lifestyle, caregiving burden and use of fall prevention strategies. This paper highlights the importance of recognising carers’ fall concern so as to identify carers’ needs and awareness of fall prevention in older people living at home. Greater insight into carers’ fall concern could facilitate the implementation of new strategies to manage older people’s fall risk as well as improve carers’ well-being.     

Pyrolysis Kinetic Properties of Thermal Insulation Waste Extruded Polystyrene by Multiple Thermal Analysis Methods

Extruded polystyrene (XPS) is a thermal insulation material extensively applied in building systems. It has attracted much attention because of outstanding thermal insulation performance, obvious flammability shortcoming and potential energy utilization. To establish the reaction mechanism of XPS’s pyrolysis, thermogravimetric experiments were performed at different heating rates in nitrogen, and multiple methods were employed to analyze the major kinetics of pyrolysis. More accurate kinetic parameters of XPS were estimated by four common model-free methods. Then, three model-fitting methods (including the Coats-Redfern, the iterative procedure and masterplots method) were used to establish the kinetic model. Since the kinetic models established by the above three model-fitting methods were not completely consistent based on different approximations, considering the effect of different approximates on the model, the reaction mechanism was further established by comparing the conversion rate based on the model-fitting methods corresponding to the possible reaction mechanisms. Finally, the accuracy of the above model-fitting methods and Particle Swarm Optimization (PSO) algorithm were compared. Results showed that the reaction function g(α) = (1 − α)⁻¹ − 1 might be the most suitable to characterize the pyrolysis of XPS. The conversion rate calculated by masterplots and PSO methods could provide the best agreement with the experimental data.     

The enigmatic role of cholinergic reflex in the pathogenesis of Chagas disease

This study evaluated the inflammatory process in the colons of mice infected with Trypanosoma cruzi QM2 strain, through the analysis of muscle reactivity and the measurement of butyrylcholinesterase (BuChE) in plasma. “Swiss” mice were infected with T. cruzi QM2 strain and after 15 (G15), 30 (G30), 60 (G60), 90 (G90), and 210 (G210) days, each group had blood collected for the measurement of butyrylcholinesterase plasma concentrations ([BuChE]), a measure which functioned as an indicator of plasmatic Ach levels. All groups, except G15, had a segment of proximal colon removed to assess muscle reactivity to acetylcholine (Ach) and noradrenaline (NA) stimulation. After reactivity tests, the tissues were then fixed and stained with hematoxylin and eosin (HE) for histological evaluation of inflammatory response. The QM2 strain did induce inflammatory process in mice colon, and demonstrated differences in muscular contraction between the G60 and G210 groups, with p?<?0.05. Plasma [BuChE] increased during the acute phase of infection (p?<?0.05) with subsequent heterogeneous decline in the late chronic phase. These results show that the QM2 strain has tropism to the colon of mice and causes damage characteristic of megacolon; also, Ach has an enigmatic importance in the anti-inflammatory reflex over the course of T. cruzi infection.     

Magnitude and mechanisms of glucose counterregulation following islet transplantation in patients with type 1 diabetes suffering from severe hypoglycaemic episodes

Aims/hypothesis

Pancreatic islet transplantation stabilises glycaemic control in type 1 diabetes mellitus patients with neuroglycopoenia, despite them not achieving insulin independence because of limited graft function. However, the extent and underlying metabolic pathways of restored glucose counterregulation are unknown. We therefore compared systemic glucose turnover, including lactate gluconeogenesis (GN) and muscle glucose uptake, in individuals with type 1 diabetes who were transplant recipients with partial graft function (T1DM/ITx⁺), matched non-transplanted individuals with type 1 diabetes (T1DM/ITx^?) and matched healthy non-diabetic individuals.

Methods

Participants (n?=?12 in each group) underwent a euglycaemic and a hypoglycaemic (2.5–2.8 mmol/l) hyperinsulinaemic clamp (0.8 mU kg^?1 min^?1) in a randomised crossover fashion. Systemic and skeletal muscle glucose and lactate kinetics were assessed using a combination of isotopic and forearm balance techniques.

Results

Whole-body glucose counterregulation, the difference in glucose infusion rates required to maintain the glycaemic goal between the hypoglycaemic and euglycaemic clamps, was improved in T1DM/ITx⁺ (7.8?±?1.3 μmol kg^?1 min^?1) compared with T1DM/ITx^? (0.3?±?0.9 μmol kg^?1 min^?1), but was ～45% lower than in controls (14.1?±?2.1 μmol kg^?1 min^?1). Increased endogenous glucose production (EGP) and decreased systemic glucose disposal accounted for 49% and 39% of glucose counterregulation in T1DM/ITx⁺, respectively, compared with 60% and 36% in controls. Lactate GN increased in T1DM/ITx⁺ (2.7?±?0.4 μmol kg^?1 min^?1) and controls (1.7?±?0.5 μmol kg^?1 min^?1), such that it accounted for 70% and 20% of the increased EGP, respectively. Skeletal muscle accounted for similar proportions of the decrease in systemic glucose disposal in controls (49%) and T1DM/ITx⁺ (41%).

Conclusions/interpretation

Partial islet graft function improves hypoglycaemia counterregulation by increasing EGP, largely via lactate GN and decreasing systemic glucose disposal. This may explain the reduction in severe hypoglycaemic events in T1DM/ITx⁺ individuals. Trial registration: ClinicalTrials.gov NCT01668485     

Functional mechanism of tracheal relaxation,antiasthmatic, and toxicological studies of 6-hydroxyflavone

Previously, we described tracheal rat rings relaxation by several flavonoids, being 6-hydroxyflavone (6-HOF) the most active derivative of the series. Thus, its mechanism of action was determined in an ex vivo tracheal rat ring bioassay. The anti-asthmatic effect was assayed in in vivo OVAlbumin (OVA)-sensitized guinea pigs. Finally, the toxicological profile of 6-HOF was studied based on Organization of Economic Cooperation and Development guidelines with modifications. 6-HOF–induced relaxation appears to be related with receptor-operated calcium channel and voltage-operated calcium channel blockade as the main mechanism of action, and also through the production of relaxant second messengers NO and cGMP. Molecular docking supports that 6-HOF acts as calcium channel blocker and by activation of nitric oxide synthase. In addition, the in vivo anti-asthmatic experiments demonstrate the dose-dependent significant anti-allergic effect of 6-HOF induced by OVA, with best activity at 50 /kg. Finally, toxicological studies determined a LD50 > 2,000 mg/kg and, after 28 day of treatment with 6-HOF (50 mg/kg) by intragastric route, mice did not exhibit evidence of any significant toxicity. In conclusion, experiments showed that 6-HOF exerts significant relaxant activity through calcium channel blockade, and possibly, by NO/cGMP-system stimulation on rat trachea, which interferes with the contraction mechanism of smooth muscle cells in the airways. In addition, the flavonoid shows potential anti-asthmatic properties in an anti-allergic pathway. Furthermore, because the pharmacological and safety evidence, we propose this flavonoid as lead for the development of a novel therapeutic agent for the treatment of asthma and related respiratory diseases.