Construction of a full-thickness human corneal substitute from anterior acellular porcine corneal matrix and human corneal cells

AIM: To construct functional human full-thickness corneal replacements. METHODS: Acellular porcine corneal matrix (APCM) was developed from porcine cornea by decellulariztion. The biomechanical properties of anterior-APCM (AAPCM) and posterior-APCM (PAPCM) were checked using uniaxial tensile testing. Human corneal cells were obtained by cell culture. Suspending ring was designed by deformation of an acupuncture needle. MTT cytotoxicity assay was used to check the cytotoxicity of suspending ring soaking solutions. A new three-dimensional organ culture system was established by combination of suspending ring, 48-well plate and medium together. A human full-thickness corneal substitute was constructed from human corneal cells with AAPCM in an organ coculture system. Biochemical marker expression of the construct was measured by immunofluorescent staining and morphological structures were observed using scanning electron microscopy. Pump function and biophysical properties were examined by penetrating keratoplasty and follow-up clinical observations. RESULTS: There were no cells in the AAPCM or PAPCM, whereas collagen fibers, Bowman’s membrane, and Descemet’s membrane were retained. The biomechanical property of AAPCM was better than PAPCM. Human corneal cells grew better on the AAPCM than on the PAPCM. There was no cytotoxicity for the suspending ring soaking solutions. For the constructed full-depth human corneal replacements keratocytes scattered uniformly throughout the AAPCM and expressed vimentin. The epithelial layer was located on the surface of Bowman’s membrane and composed of three or four layers of epithelial cells expressing cytokeratin 3. One layer of endothelial cells covered the stromal surface of AAPCM, expressed Na+/K+ATPase and formed the endothelial layer. The construct was similar to normal human corneas, with many microvilli on the epithelial cell surface, stromal cells with a long shuttle shape, and zonula occludens on the interface of endothelial cells. The construct withstood surgical procedures during penetrating keratoplasty. The corneal transparency increased gradually and was almost completely restored 7d after surgery. CONCLUSION: AAPCM is an ideal scaffold for constructing full-thickness corneal replacement, and functional human full-thickness corneal replacements are successfully constructed using AAPCM and human corneal cells.     

Quantitative tissue velocity imaging evaluation of ventricular function in obstructive sleep apnoea–hypopnoea syndrome in children

This study aimed to evaluate the changes in left and right ventricular functions of children with obstructive sleep apnoea–hypopnoea syndrome (OSAHS) and to determine the efficacy of surgical treatment for OSAHS in children. The subjects included 20 normal controls and 55 children of OSAHS with adenoid and/or tonsil hypertrophy diagnosed by polysomnography (PSG). We divided the children with OSAHS into the mild group, moderate group and severe group of OSAHS according to the condition of apnoea–hypopnoea index (AHI) and the lowest of oxygen saturation (LSaO₂). In mitral annulus,the Va values were increased in moderate and severe OSAHS (P > 0.05), and the Ve/Va values were decreased in the severe group (P > 0.05), while the Vs values were not changed (P > 0.05). In tricuspid annulus, the Vs values were decreased in moderate and severe OSAHS (P < 0.05), while the Ve, Va and Ve/Va values were not changed (P > 0.05). Six months after adenoidectomy and/or tonsillectomy, mitral Va values were decreased and tricuspid Vs values were increased significantly (P < 0.05), and AHI was decreased and LSaO₂ was significantly increased (P < 0.05). Compared with the control group, no difference was found in the above parameters (P > 0.05). The left ventricular diastolic function and the right ventricular systolic function of children with moderate to severe OSAHS are decreased to varying degrees at an early stage. Mitral annular and tricuspid annular velocity detected by quantitative tissue velocity imaging (QTVI) could sensitively reflect the early changes of left and right ventricular function. Adenoidectomy and/or tonsillectomy were effective methods to treat childhood OSAHS, which could reverse myocardial dysfunction.     

Roles and competencies in the nutritional domain for the management of the metabolic diseases and in the hospital setting: A position paper of the Italian College of Academic Nutritionists,MED-49 (ICAN-49)

Epidemiological evidence has confirmed the potential causal relationship between specific dietary factors and non-communicable diseases. However, currently nutrition was shown to be insufficiently integrated into medical education, regardless of the country. Without an adequate nutrition education, it is reasonable to assume that future physicians, as well as other health care professionals, will be not able to provide the highest quality care to patients in preventing and treating non-communicable diseases. Furthermore, the insufficient availability of physicians with specializations in nutrition has posed the basis for the development of non-medical careers in the field of nutrition. The present document was drafting by the Italian College of Academic Nutritionists, MED-49 (ICAN-49), with the aim to provide an overview on the nutritional competency standards covered by several health care professionals (Physicians Clinical Nutrition Specialists, Clinical Dietitians, Professional Clinical Nutrition Specialists, etc) for the prevention of diseases and/or support of pharmacological therapies. The aim of the ICAN 49 is to suggest a major shift in practice opportunities and roles for many nutritionists, especially for the management of the metabolic diseases, and promote a paradigm change: a clinical and educational leadership role for Physician Clinical Nutrition Specialists in the hospital setting.