Spina bifida is among the phenotypes of the larger condition known as neural tube defects (NTDs). It is the most common central nervous system malformation compatible with life and the second leading cause of birth defects after congenital heart defects. In this review paper, we define spina bifida and discuss the phenotypes seen in humans as described by both surgeons and embryologists in order to compare and ultimately contrast it to the leading animal model, the mouse. Our understanding of spina bifida is currently limited to the observations we make in mouse models, which reflect complete or targeted knockouts of genes, which perturb the whole gene(s) without taking into account the issue of haploinsufficiency, which is most prominent in the human spina bifida condition. We thus conclude that the need to study spina bifida in all its forms, both aperta and occulta, is more indicative of the spina bifida in surviving humans and that the measure of deterioration arising from caudal neural tube defects, more commonly known as spina bifida, must be determined by the level of the lesion both in mouse and in man.

The molecular basis of neural fold adhesion and fusion is a poorly understood aspect of neurulation. Cell surface glycosyl phosphatidylinositol (GPI)-anchored proteins have been implicated in neural fold adhesion, with ephrinAs particularly attractive candidates in view of the cranial neural tube defects observed in mice lacking ephrinA5 or the EphA7 receptor. Here, we demonstrate that ephrinsA1, A3 and A4, as well as several EphA receptors, are expressed in the closing mouse spinal neural tube. Most ephrinAs and EphA receptors were found to be expressed in multiple tissues in the caudal region, whereas EphA2 receptor was expressed specifically at the apices of the neural folds just prior to onset of neural tube fusion. Using mouse whole embryo culture, we found that cleavage of GPI-anchored molecules from the embryonic cell surface resulted in delay of spinal neural tube closure. Injection of EphA1 and EphA3 fusion proteins intra-amniotically into cultured embryos was used to specifically disrupt ephrinA-EphA receptor interactions, and led to inhibition of spinal neural tube closure, without adverse effects on growth or developmental progression. These treatments did not disturb neural plate bending or neural fold elevation, both of which are critical for spinal neural tube closure. Our findings demonstrate that ephrinA-EphA receptor interactions are required for closure of the mouse spinal neural tube, and support the hypothesis that ephrinA-EphA receptor interactions may participate in the molecular recognition events that culminate in adhesion and fusion of the tips of the neural folds during spinal neurulation.

Molecular techniques are invaluable for investigation on the biodiversity of Anopheles mosquitoes. This study aimed at investigating the spatial-genetic variations among Anopheles mosquitoes from different areas of Peninsular Malaysia, as well as deciphering evolutionary relationships of the local Anopheles mosquitoes with the mosquitoes from neighbouring countries using the anopheline ITS2 rDNA gene.

Background: The aim of this study is to review the medical history of patients with spina bifida, encompassing both aperta and occulta types born between the years 2003 until 2016, spanning a 13-year time period. We assessed each patient and maternal parent information, details of the defects and conditions associated with the primary defect. We also include information on patients’ ambulation and education level (where available). Methods: Data from the Department of Patient Information University of Malaya Medical Centre (UMMC), Malaysia was captured from spina bifida patients (ICD10: Q05 spina bifida). Data involved patients referred to UMMC between 2003 and 2016 and/or born in UMMC within that particular time frame. We filtered and extracted the information according to the data of clinical examination, medical review and social history provided in the medical records. Results: A total of 86 patient records with spina bifida were analysed. Spina bifida prevalence rate in this study ranged from 0.89 - 1.87 per 1000 live births depending on weightage. We note that ethnicity was a factor whereby the highest numbers of spina bifida were from Malays (n= 36, 41.86 %), followed by equal numbers of Chinese and Indians (n=24, 27.91%). The highest number of diagnoses reported was myelomeningocele type-spina bifida (n= 39, 45.35 %). The most common site of the spina bifida lesion was located at the lumbar region irrespective of aperta or occulta types (n= 23, 26.74 %). Data on other associated phenotypes of spina bifida such as hydrocephalus and encephalocele was also captured at 37.21% (n=32) and 1.16% (n=1) respectively. In terms of mobility, 32.84% (n=22/67) of patients between the ages 4 to 16 years old were found to be mobile. As many as 36.07% of patients ranging from 5 to 16 years of age (n=22/61) received formal education ranging from preschool to secondary school. Conclusions: The prevalence of spina bifida in UMMC is as according to international statistics which is in the range of 0.5 -10 per 1000 live births. Majority of the reported cases were males, Malays, full term babies, and of the myelomeningocele phenotype located at the lumbar region.