ABSTRACT
Alzheimer's disease (AD) is characterized by decreased neuronal activity and atrophy, while hyperactivity of neurons seems to make them resistant to aging and neurodegeneration, a phenomenon which we have paraphrased as 'use it or lose it'. Our hypothesis proposes that (1) during their functioning, neurons are damaged; (2) accumulation of damage that is not repaired is the basis of aging; (3) the vulnerability to AD is determined by the genetic background and the balance between the amount of damage and the efficiency of repair, and (4) by stimulating the brain, repair mechanisms are stimulated and cognitive reserve is increased, resulting in a decreased rate of aging and risk for AD. Environmental stimulating factors such as bilingualism/multilingualism, education, occupation, musical experience, physical exercise, and leisure activities have been reported to reduce the risk of dementia and decrease the rate of cognitive decline, although methodological problems are present.
Subject(s)
Animals , Humans , Brain , Pathology , Dementia , Genetics , Pathology , Models, NeurologicalABSTRACT
<p><b>OBJECTIVE</b>To investigate the frequency distribution of human platelet antigen allele HPA-2 and HPA-15 among the pediatric patients with acute or chronic idiopathic thrombocytopenic purpura (ITP) in Chinese Guangxi area, and to explore the potential correlation of ITP with HPA-2 and HPA-15 gene polymorphisms.</p><p><b>METHODS</b>The clinical and laboratorial data of 46 children diagnosed as acute ITP and 46 children diagnosed as chronic ITP between January 2007 and December 2014 were collected. Genotyping of HPA-2 and HPA-15 in 92 ITP patients and 48 healthy controls was performed by using polymerase chain reaction (PCR) combined with direct sequencing.</p><p><b>RESULTS</b>The allele frequencies of HPA-2 and HPA-15 were significantly different among the acute, chronic and control groups; the allele frequencies were significantly different between the chronic ITP group and the control group (P<0.0167), while the difference was not statistically significant between the acute and chronic ITP groups as well as between the acute ITP and the control group (P>0.0167).</p><p><b>CONCLUSION</b>The gene polymorphism of HPA-2 and HPA-15 may correlate with the risk of chronic ITP, but may not correlate with acute ITP in children.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To investigate frequency distribution of gene polymorphisms of PRF1 gene in children with hemophagocytic lymphohistiocytosis (HLH), and to explore whether the possible gene polymorphisms of PRF1 gene confer an increased risk of susceptibility to HLH.</p><p><b>METHODS</b>Forty-eight children who were diagnosed with HLH between January 2009 and December 2013 (HLH group) and 100 healthy children (control group) were enrolled in this study. The gene polymorphisms in the coding region of PRF1 gene, which consists of three exons and two introns, were genotyped by PCR, followed by direct sequencing.</p><p><b>RESULTS</b>Three single nucleotide polymorphisms (SNPs) were revealed in the coding sequence of PRF1 in the 48 children with HLH. Seven SNPs were detected in the noncoding sequence. Other two SNPs in the noncoding sequence including rs10999426 and rs10999427 were detected only in 5 healthy children (5%). There was no significant difference in allelic frequencies of all the SNPs above between the HLH and control groups (P>0.05). Haplotype analysis showed there was a pair-wise linkage disequilibrium between rs10999426 and rs10999427 (D=1, r2=1), but there was no significant difference in the distribution of A-T haplotype between the HLH and control groups (P>0.05).</p><p><b>CONCLUSIONS</b>There is no association between gene polymorphisms of PRF1 gene and the susceptibility to HLH. There is a pair-wise linkage disequilibrium between rs10999426 and rs10999427, but a low detection rate of A-T haplotype in healthy children indicates that it might not play a protective role in the development of HLH.</p>