Search results for "Polymorphism"
showing 10 items of 1968 documents
Intrinsic absorption threshold of stishovite and coesite
2004
Abstract The optical absorption spectra of the small mono-crystals samples of stishovite and coesite were studied at first. The intrinsic absorption threshold of stishovite is determined at 8.75 eV, being probably, highest in the family of different crystalline polymorph modifications of silicon dioxide. The absorption spectrum of stishovite is independent of temperature (studied in the range 290–450 K). The intrinsic absorption threshold of coesite mono-crystal situated near 8.6 eV at 293 K, coincides within experimental errors with that of α-quartz crystal, and depends on temperature, as used to be for the tetrahedron structured silicon dioxide crystalline modifications. A broad absorptio…
High-Resolution Solid-State NMR Spectroscopy of Steroids and Their Derivatives
2013
Abstract: Steroids are an important class of organic compounds containing a vast array of biologically and physiologically essential molecules. Due to their availability, relatively straightforward derivatizability, and endogeneity, they are widely used in pharmacological applications. The investigation of molecular and physicochemical properties of active pharmaceutical ingredients (APIs) in the solid state is important, because these properties are directly related to their pharmacological activity. Several methods are available for this purpose. Solid-state NMR spectroscopy offers a nondestructive and flexible technique, providing both structural and dynamic information. It can be applie…
TP53 and p16INK4A, but not H-KI-Ras, are involved in tumorigenesis and progression of pleomorphic adenomas.
2006
The putative role of TP53 and p16INK4A tumor suppressor genes and Ras oncogenes in the development and progression of salivary gland neoplasias was studied in 28 cases of pleomorphic adenomas (PA), 4 cases of cystic adenocarcinomas, and 1 case of carcinoma ex-PA. Genetic and epigenetic alterations in the above genes were analyzed by Polymerase Chain Reaction/Single Strand Conformational Polymorphism (PCR/SSCP) and sequencing and by Methylation Specific-PCR (MS-PCR). Mutations in TP53 were found in 14% (4/28) of PAs and in 60% (3/5) of carcinomas. Mutations in H-Ras and K-Ras were identified in4%(1/28) and7% (2/28) of PAs, respectively. Only 20% (1/5) of carcinomas screened displayed mutatio…
Genetic variation and urine cadmium levels: ABCC1 effects in the Strong Heart Family Study
2021
Abstract Genetic effects are suspected to influence cadmium internal dose. Our objective was to assess genetic determinants of urine cadmium in American Indian adults participating in the Strong Heart Family Study (SHFS). Urine cadmium levels and genotyped short tandem repeat (STR) markers were available on 1936 SHFS participants. We investigated heritability, including gene-by-sex and smoking interactions, and STR-based quantitative trait locus (QTL) linkage, using a variance-component decomposition approach, which incorporates the genetic information contained in the pedigrees. We also used available single nucleotide polymorphisms (SNPs) from Illumina’s Metabochip and custom panel to ass…
Influence of polymorphisms in anthracyclines metabolism genes in the standard induction chemotherapy of acute myeloid leukemia
2021
Objectives Genetic variability in anthracycline metabolism could modify the response and safety of acute myeloid leukemia (AML) induction. Methods Polymorphisms in genes that encodes enzymes of anthracyclines metabolic pathway (CBR3: rs1056892, rs8133052, NQO1: rs1800566, NQO2: rs1143684, NOS3: rs1799983, rs2070744) were evaluated in 225 adult de novo AML patients. Results The variant CBR3 rs8133052 was associated with lower hepatotoxicity (P = 0.028). Wild-type genotype of NQO2 rs1143684 was related to higher complete remission (P = 0.014), and the variant allele with greater gastrointestinal toxicity (P = 0.024). However, the variant genotype of NQO1 rs1800566 was associated with mucositi…
Comparative genetic study of intratumoral heterogenous MYCN amplified neuroblastoma versus aggressive genetic profile neuroblastic tumors.
2016
Intratumoral heterogeneous MYCN amplification (hetMNA) is an unusual event in neuroblastoma with unascertained biological and clinical implications. Diagnosis is based on the detection of MYCN amplification surrounded by non-amplified tumor cells by fluorescence in situ hybridization (FISH). To better define the genetic features of hetMNA tumors, we studied the Spanish cohort of neuroblastic tumors by FISH and single nucleotide polymorphism arrays. We compared hetMNA tumors with homogeneous MNA (homMNA) and nonMNA tumors with 11q deletion (nonMNA w11q-). Of 1091 primary tumors, 28 were hetMNA by FISH. Intratumoral heterogeneity of 1p, 2p, 11q and 17q was closely associated with hetMNA tumor…
Thymidylate synthase gene promoter polymorphisms are associated with TSmRNA expressions but not with microsatellite instability in colorectal cancer
2005
Abstract BACKGROUND: Microsatellite instability (MSI) is a biological characteristic of most tumours, being involved in 85% of hereditary non-polyposis colorectal cancer (HNPCC). It also occurs in 10-15% of sporadic colorectal cancers (CRC). HNPCC appears to be caused by germline mutations in mismatch repair (MMR) genes, which are responsible for repairing single base-pair mismatches. MSI is also associated with a better response of CRC to adjuvant chemotherapy with fluoropyrimidines. We investigated any relationship between the MSI status and the TSmRNA expression, the polymorphisms of 5-Fluorouracil (5-FU cellular target, the enzyme thymidylate synthase (TS) and TS expression evaluated by…
TLR2 and age-related diseases: potential effects of Arg753Gln and Arg677Trp polymorphisms in acute myocardial infarction.
2008
ABSTRACT Inflammation is a key component of immune system. It is involved in both defense and pathophysiological events maintaining the dynamic homeostasis of host organism. Its function is controlled by innate immunity genes. Both their polymorphisms and environmental conditions give rise to different phenotypes in human population. Proinflammatory genotype may be beneficial in early life but not in old people. With advancing age, indeed, it increases the vulnerability and the intensity to inflammatory reactions responsible for the chronic inflammatory diseases, such as atherosclerosis and myocardial infarction (MI). Several studies have looked for detecting a genetic risk profile that mig…
Association of Klotho Polymorphisms with Healthy Aging: A Systematic Review and Meta-Analysis
2013
Today it is clearly evident that genetic background constitutes an integral part of aging and longevity. Many studies on long-lived people have been conducted emphasizing the role of certain genes in long life. Classic case-control studies, genome-wide association studies, and high-throughput sequencing have permitted identification of a variety of genetic variants seemingly associated with longevity. Over the years, aging research has focused on the insulin/insulin-like growth factor-1 (IGF-1) signaling pathway because of its evolutionarily conserved correlation with life-span extension in model animals. Indeed, many single-nucleotide polymorphisms (SNPs) associated with longevity were ide…
SHIP2: A “NEW” Insulin Pathway Target for Aging Research
2014
Strong evidence suggests that systemic inflammation and central adiposity contribute to and perpetuate metabolic syndrome. All of these alterations predispose individuals to type 2 diabetes mellitus (T2DM), cardiovascular disease, as well as Alzheimer's disease (AD), all characterized by chronic inflammatory status. On the other hand, extensive abnormalities in insulin and insulin-like growth factor I (IGF-I) and IGF-II signaling mechanisms in brains with AD have been demonstrated, suggesting that AD could be a third form of diabetes. The Src homology domain-containing inositol 5-phosphatase 2 (SHIP2) has an important role in the insulin pathway because its over-expression causes impairment…