Changes in the gastric enteric nervous system and muscle: A case report on two patients with diabetic gastroparesis

<p>Abstract</p> <p>Background</p> <p>The pathophysiological basis of diabetic gastroparesis is poorly understood, in large part due to the almost complete lack of data on neuropathological and molecular changes in the stomachs of patients. Experimental models indicate various lesions affecting the vagus, muscle, enteric neurons, interstitial cells of Cajal (ICC) or other cellular components. The aim of this study was to use modern analytical methods to determine morphological and molecular changes in the gastric wall in patients with diabetic gastroparesis.</p> <p>Methods</p> <p>Full thickness gastric biopsies were obtained laparoscopically from two gastroparetic patients undergoing surgical intervention and from disease-free areas of control subjects undergoing other forms of gastric surgery. Samples were processed for histological and immunohistochemical examination.</p> <p>Results</p> <p>Although both patients had severe refractory symptoms with malnutrition, requiring the placement of a gastric stimulator, one of them had no significant abnormalities as compared with controls. This patient had an abrupt onset of symptoms with a relatively short duration of diabetes that was well controlled. By contrast, the other patient had long standing brittle and poorly controlled diabetes with numerous episodes of diabetic ketoacidosis and frequent hypoglycemic episodes. Histological examination in this patient revealed increased fibrosis in the muscle layers as well as significantly fewer nerve fibers and myenteric neurons as assessed by PGP9.5 staining. Further, significant reduction was seen in staining for neuronal nitric oxide synthase, heme oxygenase-2, tyrosine hydroxylase as well as for c-KIT.</p> <p>Conclusion</p> <p>We conclude that poor metabolic control is associated with significant pathological changes in the gastric wall that affect all major components including muscle, neurons and ICC. Severe symptoms can occur in the absence of these changes, however and may reflect vagal, central or hormonal influences. Gastroparesis is therefore likely to be a heterogeneous disorder. Careful molecular and pathological analysis may allow more precise phenotypic differentiation and shed insight into the underlying mechanisms as well as identify novel therapeutic targets.</p

Gender in STEM Education: an Exploratory Study of Student Perceptions of Math and Science Instructors in the United Arab Emirates

© 2015, Ministry of Science and Technology, Taiwan. The current study addresses student perceptions of math and science professors in the Middle East. Gender disparity in science, technology, engineering, and math (STEM) education continues to exist in higher education, with male professors holding a normative position. This disparity can also be seen in the United Arab Emirates. As female participation in STEM education lags behind men, it is possible that gender stereotypes may influence students’ first impressions of male and female instructors. The United Arab Emirates provides a unique context to study this phenomenon as it is a traditional patriarchal society that is highly dependent on the engineering discipline, especially within the oil and gas sectors. A total of 176 undergraduate students from 2 universities in the United Arab Emirates completed a survey about teaching effectiveness based on their perceptions of photographs of hypothetical male and female instructors. A factor analysis of survey items revealed 2 main subcategories of teacher effectiveness: namely teacher warmth and professionalism. A 2-way between-groups analysis of variance was conducted to explore the impact of teacher gender and student gender on perceptions of overall teaching effectiveness, as well as their perceptions of teacher warmth and professionalism. Findings revealed that there was a significant cross-gender effect on student perceptions of math and science instructors in the United Arab Emirates