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author:("draw, Lena")
1.  A GCH1 haplotype confers sex-specific susceptibility to pain crises and altered endothelial function in adults with sickle cell anemia 
American journal of hematology  2014;89(2):187-193.
GTP cyclohydrolase (GCH1) is rate limiting for tetrahydrobiopterin (BH4) synthesis, where BH4 is a cofactor for nitric oxide (NO) synthases and aromatic hydroxylases. GCH1 polymorphisms are implicated in the pathophysiology of pain, but have not been investigated in African populations. We examined GCH1 and pain in sickle cell anemia where GCH1 rs8007267 was a risk factor for pain crises in discovery (n = 228; odds ratio [OR] 2.26; P = 0.009) and replication (n = 513; OR 2.23; P = 0.004) cohorts. In vitro, cells from sickle cell anemia subjects homozygous for the risk allele produced higher BH4. In vivo physiological studies of traits likely to be modulated by GCH1 showed rs8007267 is associated with altered endothelial dependent blood flow in females with SCA (8.42% of variation; P = 0.002). The GCH1 pain association is attributable to an African haplotype with where its sickle cell anemia pain association is limited to females (OR 2.69; 95% CI 1.21–5.94; P = 0.01) and has the opposite directional association described in Europeans independent of global admixture. The presence of a GCH1 haplotype with high BH4 in populations of African ancestry could explain the association of rs8007267 with sickle cell anemia pain crises. The vascular effects of GCH1 and BH4 may also have broader implications for cardiovascular disease in populations of African ancestry.
PMCID: PMC4281092  PMID: 24136375
2.  Serum pepsinogens and Helicobacter pylori in relation to the risk of esophageal squamous cell carcinoma in the ATBC Study 
Helicobacter pylori (H. pylori) can induce gastric atrophy in humans, which in turn increases gastric cancer risk. Whether H. pylori and gastric atrophy also affect the risk of esophageal squamous cell carcinoma (ESCC), however, remains unresolved.
We performed a nested case-control study within the prospective ATBC Study to assess these relationships. The ATBC Study is composed of 29,133 Finnish male smokers, aged 50–69, who were recruited during 1985–1988. Using baseline sera, we assessed H. pylori status (via IgG antibodies against whole-cell and CagA antigens) and gastric atrophy status (via the biomarkers pepsinogen I (PGI) and II (PGII)) in 79 ESCC cases and 94 controls. Logistic regression with adjustment for age, date of blood draw, education, cigarette smoking, alcohol, body mass index, and fruit and vegetable intake was used to estimate odds ratios (OR) and 95% confidence intervals (95%CI).
Gastric atrophy (PGI:PGII <4) was associated with ESCC (OR=4.58, 95%CI:2.00–10.48). There was no evidence for an association between H. pylori and ESCC (OR=0.94, 95%CI:0.40–2.24).
These results could be explained by misclassification of H. pylori status due to serologic amnesia, ESCC risk being dependent upon the functional consequences or interactions of H. pylori, rather than the infection per se, gastric atrophy having a different histogenesis in ESCC without being primarily dependent upon H. pylori acquisition, or a lack of statistical power to detect an effect.
Validation of these results may warrant mechanistic studies to determine the route of association between gastric atrophy and ESCC.
PMCID: PMC2919643  PMID: 20647397
Atrophy; Esophageal Neoplasms; Helicobacter pylori; Nested Case-Control Studies; Pepsinogens; Prospective Studies
3.  Serum pepsinogens and risk of esophageal squamous dysplasia 
Pepsinogens are a class of endopeptidases that are secreted by the gastric epithelium and released into the circulation. Low serum pepsinogen I (PGI) and low serum pepsinogen I / pepsinogen II ratio (PGI/II ratio) are markers of gastric fundic atrophy, and have recently been shown to be associated with increased risk of esophageal squamous cell carcinoma (ESCC). We conducted the current study to test whether these markers are also associated with esophageal squamous dysplasia (ESD), the precursor lesion of ESCC.
We measured serum PGI and PGII, using enzyme-linked immunosorbent (ELISA) assays, in 125 case subjects (patients with moderate or severe ESD) and 250 sex-matched control subjects (no ESD) selected from an endoscopic screening study in Linxian, China. We used conditional logistic regression models adjusted for age, smoking, and place of residence to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs).
Serum PGI showed no statistically significant association with ESD, whether analyzed as a dichotomous, ordinal (quartiles), or continuous variable. Lower serum PGI/II ratio, however, showed a dose-response association with increased risk of ESD, with an adjusted OR (95% CI) of 2.12 (1.08 − 4.18), comparing the lowest versus the highest quartile. The association between lower serum PGI/II ratio and log OR of ESD was nearly linear, and the p-value for the continuous association was 0.03.
Lower serum PGI/II ratio was linearly associated with higher risk of ESD. This result is consistent with recent findings that gastric atrophy may increase the risk of ESCC.
PMCID: PMC2605159  PMID: 18844222
Esophageal cancer; Squamous dysplasia; Pepsinogen; China
4.  Prostate Cancer Epigenetics: A Review on Gene Regulation 
Prostate cancer is the most common cancer in men in western countries, and its incidence is increasing steadily worldwide. Molecular changes including both genetic and epigenetic events underlying the development and progression of this disease are still not well understood. Epigenetic events are involved in gene regulation and occur through different mechanisms such as DNA methylation and histone modifications. Both DNA methylation and histone modifications affect gene regulation and play important roles either independently or by interaction in tumor initiation and progression. This review will discuss the genes associated with epigenetic alterations in prostate cancer progression: their regulation and importance as possible markers for the disease.
PMCID: PMC2759139  PMID: 19936097
epigenetics; methylation; histone modification; gene regulation; prostate cancer
5.  Restricted Immunoglobulin Variable Region (Ig V) Gene Expression Accompanies Secondary Rearrangements of Light Chain Ig V Genes in Mouse Plasmacytomas 
The Journal of Experimental Medicine  1999;190(10):1405-1416.
The many binding studies of monoclonal immunoglobulin (Ig) produced by plasmacytomas have found no universally common binding properties, but instead, groups of plasmacytomas with specific antigen-binding activities to haptens such as phosphorylcholine, dextrans, fructofuranans, or dinitrophenyl. Subsequently, it was found that plasmacytomas with similar binding chain specificities not only expressed the same idiotype, but rearranged the same light (VL) and heavy (VH) variable region genes to express a characteristic monoclonal antibody. In this study, we have examined by enzyme-linked immunosorbent assay five antibodies secreted by silicone-induced mouse plasmacytomas using a broader panel of antigens including actin, myosin, tubulin, single-stranded DNA, and double-stranded DNA. We have determined the Ig heavy and light chain V gene usage in these same plasmacytomas at the DNA and RNA level. Our studies reveal: (a) antibodies secreted by plasmacytomas bind to different antigens in a manner similar to that observed for natural autoantibodies; (b) the expressed Ig heavy genes are restricted in V gene usage to the VH-J558 family; and (c) secondary rearrangements occur at the light chain level with at least three plasmacytomas expressing both κ and λ light chain genes. These results suggest that plasmacytomas use a restricted population of B cells that may still be undergoing rearrangement, thereby bypassing the allelic exclusion normally associated with expression of antibody genes.
PMCID: PMC2195694  PMID: 10562316
V(D)J rearrangement; plasmacytoma; allelic exclusion; polyreactivity; V gene usage

Results 1-5 (5)