[Show abstract][Hide abstract] ABSTRACT: In human five chromosomal loci encode ~ 360 copies ribosomal genes are called nucleolar organizer regions (NORs). These are located on the short arm of the acrocentric chromo-somes. The exact role of NORs is not known but it helps in the assembly of ribosomes during cell-division (mitosis). In the present case study the Down syndrome case used as model of non -disjunction event because of having an extra copy of acrocentric chromosome become imperative to know the associations between acrocentric chromosomes and NORs sites asso-ciated transcriptional event. In this case high incidence of NORs expression (>60% / cell) were observed. However, this study of NORs explores the mechanism of transcription dur-ing neuronal differentiation causes "mental retardation" has not been documented earlier in the literature.
Preview · Article · Jan 2011 · Current Pediatric Research
[Show abstract][Hide abstract] ABSTRACT: Cystathionine beta synthase gene (CβS) catalyzes the condensation of homocysteine with serine, forming cystathionine by the transsulfuration pathway. Disruption of CβS enzyme activity due to defective folic acid metabolism increases the risk factor for neural tube defects. We evaluated the CβS gene mutation in 25 children with neural tube defects (NTDs), including lumbosacral and thoracic myelomeningocele and open NTDs and mothers of cases, along with 25 healthy children and their mothers, serving as controls. Genomic DNA was isolated to assess the polymorphism of 852Ins68 in the CβS gene using PCR-RFLP analysis and nucleotide sequencing techniques. The 68-bp insertion was observed in one of the 25 NTD cases (lumbosacral myelomeningocele), and in two of the mothers of NTD cases. Statistical analysis was carried out using the Fischer exact probability test, which showed a lack of significance (P > 0.05), but the odds ratio of 2.08 with 95% confidence interval of 0.17-24.6 in NTDs mother was quite high because of the small sample size. However, the study was further extended to find out the involvement of specific nucleotide sequences, which again confirmed the 852Ins68 insertion and replacement of nucleotides (TCCAT to GGGG) in lumbosacral myelomeningocele (due to other category of NTDs), suggesting that it could be an independent risk factor for birth defects, including NTDs.
Full-text · Article · Jan 2011 · Genetics and molecular research: GMR
[Show abstract][Hide abstract] ABSTRACT: Infertility is a major reproductive health threat; the frequency of male infertility due to Y-chromosome microdeletions is 13-18% in the human population; these microdeletions involve recurrent loss of three non-overlapping regions designated as AZFa, AZFb and AZFc, associated with spermatogenic failure. Several contradictory reports have been published regarding deletion frequency based on sequence-tagged site markers and genotype-phenotype correlation. We examined the prevalence of Yq- deletion in 64 clinically diagnosed infertile male patients. We found a 3% frequency of microdeletion of the AZFc region; hormone profiles (FSH, LH and testosterone) showed significantly (P < 0.001) elevated levels compared to controls. No mutations were observed in the AZFa and AZFb regions, perhaps due to the selective use of sequence-tagged site markers.
Full-text · Article · Jan 2010 · Genetics and molecular research: GMR
[Show abstract][Hide abstract] ABSTRACT: While the WHO's general alignment for malignancies & diabetic impacts only one quarter of the world's population, the Indian population is negatively skewed outside of such malignancies & diabetic range. Stem cells (SCs) are undifferentiated highly specialized kinds of cell types having capacity to renew itself, found in different tissue or organ. SCs are capable of dividing for long period of time to furnish grow different cell types with specific functions. It took about twenty years to gain knowledge of how to grow embryonic stem cell in-vitro. The primary roles of adult stem cells in a living organism are to renew or maintain and repairthe injured tissue in which they are found. SCs are classified in to two categories on the basis of their origin and their functional properties. First the embryonic stem cells originate from the inner cell mass of the blastocyst, while second is of adult stem cells. Another category of stem cells are the amniotic fluid derived embryonic cells (AFEc) having equally important cells which transform into various types of tissues present in fat, bone, muscles, liver and blood vessels. The main advantage of AFEc is to use these cells without or disturbing or touching embryo. Embryonic stem cell expresses specific markers of self renewal and pluripotency including transcription factor like SOX-2, LIF etc. Bone--marrow contains two kinds of stem cells, one haemotopoietic which form the blood and second stroma which form mixed cell population like bone, cartilage fat and fibrous connective tissue. Cellular differentiation of stem cells is inimitable and based on either intrinsic or extrinsic signals and during migration cancer stem cell loses cell polarity which leads to epithelial to mesenchymal transition (ENT). These signals named genes which carry coded instructions (novel molecules) for all the structure and function. External signals are chemical molecules secreted by other neighboring cell through physical contact (paracrine regulation). Efforts are being done to grow both embryonic and adult stem cells using "tissue culture engineering" in vitro. SCs could be used for various therapeutic purposes like Parkinson's patients, Alzheimer's disease & other neurological disorders patients, repairing for damaged heart muscles and for type I diabetes patients as an alternative source of chemotherapy including trauma patients which is not only expensive but lack of side effect too.
Full-text · Article · Jan 2010 · Journal of Experimental Therapeutics and Oncology