Clodronate-superparamagnetic iron oxide-containing liposomes attenuate renal injury in rats with severe acute pancreatitis

Background and objective

It has been shown that macrophages play an important role in the development of severe acute pancreatitis (SAP), and eventually lead to multiple organ failure (MOF). Clodronate-liposome selectively depleted macrophages. This study was to investigate the role of renal macrophage infiltration in acute renal injury in rats with SAP and to evaluate the potential of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) for diagnosis.

Methods

Superparamagnetic Fe₃O₄ nanoparticles were prepared by chemical coprecipitation. SPIO-liposomes and SPIO-clodronate-liposomes were prepared by the thin film method. SAP models were prepared by injection of sodium taurocholate into the subcapsular space of rat pancreas. Sprague-Dawley rats were randomly divided into a control group, SAP plus SPIO-liposome (P) group, and SAP plus SPIO-clodronate-containing liposome (T) group. Kidney injury was evaluated by T2-weighted MRI scan. The levels of serum amylase (SAM), blood urea nitrogen (BUN), and serum creatinine (SCr) were measured by an automated enzymatic method. Serum tumor necrosis factor-α (TNF-α) was measured by enzyme-linked immunosorbent assay (ELISA). Pathological changes in the pancreas and kidney were observed using hematoxylin and eosin (H&E) staining, while cell apoptosis was detected with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. In addition, the macrophage markers (CD68) of the renal tissue were detected with immunohistochemistry.

Results

The pathological changes in the pancreas and kidneys of rats in the T group were milder than those in the P group. The MRI signal intensity of the kidneys in the P and T groups was significantly lower than that in the control group. There were significant changes in the two experimental groups (P<0.01). The levels of SAM, Bun, SCr, and TNF-α in rats in the P group were higher than those in the control group (P<0.01) and in the T group (P<0.01). The apoptosis of the kidney in the T group was higher than that in the P group at 2 and 6 h (P<0.01).

Conclusions

Clodronate-containing liposomes protected against renal injury in SAP rats, and SPIO can be used as a tracer for MRI examination to detect renal injury in SAP rats. SPIO-aided MRI provided an efficient non-invasive way to monitor the migration of macrophages after renal injury in rats with SAP.     

反复张力下V形切口圆条的表面裂纹的疲劳扩展

研究目的：在相同的反复张力下,研究V形切口圆条表面裂纹的疲劳扩展规律。研究方法：1.构建V形切口圆条模型（图1）,基于线性二次元将模型表面离散成一个个网格点（图2）;2.以AZ-6A-T5镁合金为例,利用J积分计算应力强度因数,利用NASGRO裂纹增长率模拟裂纹的疲劳扩展;3.通过研究不同的裂纹纵横比和对应的应力强度因数之间的相关性来研究裂纹的扩展。重要结论：1.在裂纹扩展时裂纹纵横比的初始值对断裂形状的发展有重要影响;2.裂纹纵横比对疲劳负荷寿命的作用比缺口半径更加明显;3.当裂纹前缘演变成一条直线形时可观察到不稳定的裂纹扩展;4.裂纹深度一定时,断裂纵横比越小,疲劳负荷寿命越短;5.当裂纹纵横比为0.6-0.7时,出现了不稳定的裂纹扩展。     

TESOL professional standards in the “Asian century”: dilemmas facing Australian TESOL teacher education

Australian teacher education programmes that prepare teachers of English to speakers of other languages (TESOL) are confronting the nexus of two facets of globalization: transformations in the Asian region, captured in the notion of the “Asian century”, and shifting conceptions of professionalism in TESOL in non-compulsory education. In booming Asian economies, English language learning is integral to the demand for high-quality education. This has produced increases in TESOL Teacher Education Programme (TTEP) enrolments of both domestic Australian students and international students from Asia. Growth in demand for TTEPs has necessitated that they cater to student diversity, and the intended contexts of practice. This demand has coincided with a concurrent movement towards professional standards for TESOL that, we argue, confronts complexities around quality, accountability, and professional identity and achieving conceptual and contextual coherence. Drawing on discourses of managerialism and performativity, this paper explores tensions between increased student demands for TTEPs, professional standards discourses which are part of the global policy discourses on teacher quality, and the achievement of programmatic conceptual and contextual coherence from the perspective of Australian TTEPs.     

Positioning in groups: a new development in systemic consultation

This article describes a new approach, employing a combination of Positioning Theory and Semantic Polarities, that educational psychologists can use to develop and facilitate change in organisations and groups. Resistance to change can be seen as reflecting a lack of the language that the members of an organisation need to participate effectively in the new discourses that are associated with change. Positioning Theory can be used to develop this new language of participation, which can then be used by all in the organisation or group to agree how development can happen and what their contribution to this would be.     

Critical perspectives on testing teaching: reframing teacher education for English medium instruction

The investigation reported here provides a basis for considering the role of corrective and transformative critiques in producing knowledge through testing teaching for reframing teacher education in response to, and as an expression of, the globalisation of English. This knowledge-producing approach to critique begins with a literature review of prior testing models of content and language integrated learning through English medium instruction (EMI) programmes. Delphi procedures were employed with a panel of 30 experts from three focus groups, namely teachers, testing experts, and teacher evaluation administrators. A comparison of relative importance of the indicators generated through this study via the analytic hierarchy process yielded practical implications for reframing the internationalisation of education using EMI. The analysis of interviews with teachers was used to critically rework or otherwise correct the testing model. Through adopting the practice of critique as a knowledge-producing venture, this study offers a model of EMI testing that can contribute to improvements in the organisation of professional learning and change, as well as certification procedures.     

Linear Analysis of Autonomic Activity and Its Correlation with Creatine Kinase-MB in Overt Thyroid Dysfunctions

Autonomic activity may be deranged in thyroid dysfunctions and may lead to cardiovascular morbidity and mortality. Myopathy is a common manifestation in thyroid disorders and may be associated with raised serum creatine kinase (CK). We hypothesized that cardiovascular abnormality in thyroid dysfunction may manifest as raised CK-MB. This study was designed to investigate the correlation of CK and its isoform CK-MB with thyroid profile and linear parameters of heart rate variability (HRV). The study was conducted on 35 hypothyroid and hyperthyroid patients each, and 25 age-matched healthy controls. Autonomic activity was assessed by simple short term 5-min HRV. Biochemical evaluation of serum thyroid profile, CK-NAC and CK-MB were estimated in all the subjects. Our results demonstrated low HRV in hypo- as well as hyperthyroid patients. We observed significantly higher serum CK levels in hypothyroid patients when compared to hyperthyroids and controls. However, no significant differences were observed in CK-MB levels in the three groups. Significant positive correlation of CK with TSH and negative correlation with some HRV parameters (LF power, HF power, total power, SDNN, RMSSD) was observed in hypothyroid patients. Whereas correlation of CK-MB with thyroid profile as well as HRV parameters was non-significant in all the groups. Based on the CK and CK-MB findings and their correlation, we conclude that the cardiovascular changes seen in thyroid dysfunctions may primarily be due to autonomic imbalance without apparent cardiac muscle involvement. Whereas, raised CK levels indicate predominantly skeletal muscle involvement in hypothyroid patients.     

Circadian Periodicity of Circulating Plasma Lipid Peroxides,Uric Acid and Ascorbic Acid in Renal Stone Formers

Circadian periodicity of plasma lipid peroxides and serum ascorbic acid and uric acid levels were studied in one hundred renal stone formers (55 women and 45 men; age 20–60 years) and 50 clinically healthy volunteers (21 women and 29 men; age 21–45 years) with diurnal activity from 06:00 to 22:00 and nocturnal rest. A marked circadian variation was demonstrated by population-mean-cosinor for all studied variables in stone formers and healthy subjects. By comparison to the healthy controls, parameter tests indicate that the stone formers had a higher MESOR (±SE) of MDA (2.90 ± 0.03 vs. 2.28 ± 0.06; F = 94.929, p < 0.001), a lower MESOR of serum ascorbic acid (0.722 ± 0.010 vs. 0.839 ± 0.10; F = 32.083, p < 0.001), and a similar MESOR of serum uric acid. Furthermore, the patients also differed from the healthy subjects in terms of their circadian amplitude and acrophase (tested jointly) of all three variables (p < 0.001). The demonstration herein of a circadian rhythm in MDA, serum ascorbic and uric acid suggests that these variables could also serve as markers to optimize the timing of treatment and to assess the patient’s response to treatment for further management.     

‘In most supermarkets food does not cost £3 per day …’ The impact of the school food voucher scheme during COVID-19

Households with children eligible for Free School Meals are at risk of food insecurity. This paper reports on a rapid-response study that investigated the impact of the school food voucher scheme during the COVID-19 crisis on young people, families and schools. It pays close attention to the reliance of the state on the goodwill of society and its citizens in feeding those most in need. The Capabilities Approach is used to highlight factors that inhibited and restricted the use of the vouchers to produce the capability of having good nutrition for children in need of Free School Meals. The approach moves towards creating a society where children and young people are able to lead a life of their own choice and contribute to key policy decisions. This qualitative study funded by the British Education Research Association was conducted between September 2020 and March 2021. The study posed two research questions: (1) how have schools responded to COVID-19 in relation to food during holiday provision; and (2) what have families identified as barriers to accessing the school food voucher scheme? Data collection involved online interviews with young people, schools and organisations (i.e. public health, director from the food industry. etc.). The findings highlight the difficulties with accessing and using the school food voucher and implications for future policy directions. Owing to this being a small-scale study, it is not generalisable to the wider population but does highlight localised issues.