Gastrulation and Body Axes Formation: A Molecular Concept and Its Clinical Correlates

During the third week of human pregnancy, an embryo transforms from two germinal disc layers of hypoblast and epiblast to three germinal layers of endoderm, mesoderm and ectoderm. Gastrulation is a complex process that includes cellular mobility, morphogenesis and cell signalling, as well as chemical morphogenic gradients, transcription factors and differential gene expression. During gastrulation, many signalling channels coordinate individual cell actions in precise time and location. These channels control cell proliferation, shape, fate and migration to the correct sites. Subsequently, the anteroposterior (AP), dorsoventral (DV) and left-right (LR) body axes are formed before and during gastrulation via these signalling regulation signals. Hence, the anomalies in gastrulation caused by insults to certain molecular pathways manifest as a wide range of body axes-related disorders. This article outlines the formation of body axes during gastrulation and the anomalies as well as the clinical implications

Structural and Ultrastructural Studies of Tissues Engineered Cornea

This study was carried out to evaluate corneal organisation and regeneration after transplantation of bilayer in vitro cornea construct (BICC) into the New Zealand White Strain rabbit’s eye. Studies were conducted to investigate the structural and ultrastructural features after corneal regeneration 90 days post-transplantation. The epithelial cells and keratocytes were isolated from the limbus of the rabbit and then cultured in vitro in 5 mL tissue culture flasks. BICC and fibrin without seeded cell construct (FWCC) were produced by mixing the epithelial cells and keratocytes with rabbit fibrin and calcium chloride (CaCl2) and maintained in culture media. The cornea was subjected to lamellar keratectomy before BICC and FWCC were implanted into the defect area. The transplanted corneas were harvested after 90 days post-transplantation for microscopic analysis and immunolabelling studies for cytokeratin 3. Slit lamp microscopic analysis revealed that engineered cornea (EC) showed good corneal regeneration with no significant difference in cornea transparency to normal cornea (NC). However, for fibrin cornea (FC), the cornea was opaque compared to NC. In addition, the defect cornea (DC), which was cornea without implantation after lamellar keratectomy, showed a transparent cornea similar to NC. Morphometric analysis of the corneal thickness was done by using Least Significant Difference (LSD) test and Analysis of Co-Variance, showed that EC was capable of regenerative similar thickness functional cornea as NC when compared to FC and DC (p<0.05). Scanning electron microscope (SEM) analysis demonstrated that epithelial surface of EC showed significantly similar features to NC compared to FC and DC (p<0.05). Transmission electron microscope (TEM) analysis showed that the basal lamina development of EC was similar to NC with the establishment of cell junction compared to FC and DC. Furthermore, the EC showed a compact stromal organization with homogenous collagen fibrils diameter similar to NC (p<0.05). However, FC and DC showed a loose stromal organization with heterogenous fibrils diameter, with FC fibrils diameter were bigger than that of NC; while for DC, the fibrils diameter was smaller than NC (p<0.05). Confocal microscopy analysis confirmed that the regenerated epithelial cells in all groups were corneal epithelial cells by using corneal differentiation marker, cytokeratin 3 (CK3). As a conclusion, the EC demonstrated excellent regenerative ability of cornea and better wound healing

The effects of Pueraria mirifica extract, diadzein and genistein in testosterone-induced prostate hyperplasia in male Sprague Dawley rats

Pueraria mirifica (PM) is a medicinal plant native to Thailand contained high amount of phytoestrogen and possesses anticancer activity. This study reports the effect of P. mirifica extract, phytoestrogen of diadzein and genistein for its benign prostate hyperplasia properties in testosterone-induced prostate hyperplasia in male Sprague Dawley rats. The P. mirifica extract was evaluated for its total phenols, flavonoid and antioxidant activity using DPPH, FRAP and metal chelating assay. The assessment of P. mirifica, diadzein and genistein against benign prostate hyperplasia was determined in testosterone-induced prostate hyperplasia in male Sprague Dawley rats. The total phenol was higher than flavonoid but showed low antioxidant activity of DPPH, FRAP and metal chelating. The aqueous PM extract at 1000 mg/kg significantly increased testosterone levels in testosterone-induced rats by 13% while diadzein and genistein increased it by 11% and 17% respectively. However, levels of FSH, LH, triglyceride and HDL are not affected by the oral administration of PM, diadzein and genistein to the rats. Similarly, total protein, albumin, globulin, total bilirubin, conjugated bilirubin, alkaline phosphatase, alanine aminotransferase, AST, and G-glutamyltransferase showed no significant difference as compared with negative control rats. The body weight of the rats, testis, kidney and liver showed no toxic effect. The zinc content increased significantly and the zinc transporter gen of ZnT4 and ZIP4 highly expressed suggesting that the PM, diadzein and genistein plays essential role in modulating prostate zinc homeostasis. Similarly, the expression of IL-6, AR and ER was significantly reduced indicating functioning in regulation of prostate growth and acts as anti-inflammatory role in preventing BPH. In conclusion, the results indicated that PM reduced BPH and contributed to the regulation in the zinc transport expression of the prostate cells in the benign prostate hyperplasia (BPH). © 2019, Springer Nature B.V

The association between learning styles, time management skills and pharmacology academic performance among first year medical students in Universiti Putra Malaysia (UPM) during the Covid-19 pandemic

Introduction: The scientific understanding gained from pharmacology investigations is used to support a wide range of medical therapies. As a result, pharmacology is essential in medicine. As a result of the coronavirus epidemic, several colleges throughout the world have resorted to online pharmacology learning, which has an indirect impact on student academic progress. Aside from learning styles, a student’s time management abilities are another essential aspect that affects their academic success. Methods: This is a cross-sectional study that employed a questionnaire to assess first-year medical students from Universiti Putra Malaysia’s Faculty of Medicine and Health Sciences’ learning style and time management skills. A series of pharmacological questions involving short answer questions was also given to the students to assess their pharmacology performance. Results: There was a significant weak negative correlation between superficial learning style and pharmacology performance (r=-0.272, p<.05). There was also a significant weak correlation between deep learning style and long range planning (r=0.256, p<.05) and including short range planning (r=0.263, p<0.5). Lastly, significant weak negative correlation on pharmacology performance and long range planning was seen (r=0.256, p<.05). However, there was no significant correlation between time management and pharmacology performance. Conclusion: Students that use a superficial learning style struggle in school, yet deep learning styles in both short and long term planning do not always increase pharmacology performance. A good time management skills does not guarantee a good pharmacology performance either. Other relevant factors, like as socio-demographic characteristics, that may contribute to this outcome, particularly during this epidemic, should be investigated further

Correlative transmission electron microscopy and scanning electron microscopy of rabbit cornea.

The present work was carried out to study the organization of rabbit cornea. The transparent nature of the normal cornea was very important to give the understanding of the cornea in health and disease state. The ultrastructural features of the cornea were obtained by transmission electron microscopy and scanning electron microscopy. The epithelial surface of the cornea composed of microvilli and microplicae. In the Bowman's membrane, the individual collagen fibrils were interwoven densely to form a felt-like sheet, while in the stroma, the collagen fibrils ran abreast in lamellae. In the innermost stromal region adjacent to Descemet's membrane, collagen fibrils were oriented in various directions and interlaced, forming loose fibrillar networks. The endothelial layer is a single cell layer and apically-localized below the Descemet's membrane. This present work will be a standard reference for future research pertaining to cornea particularly cornea tissue engineering