A study of pyrimidine base damage in relation to oxidative stress and cancer

Background:

A long-standing hypothesis is that oxidative stress is a risk factor for cancer. Support for this hypothesis comes from observations of higher levels of oxidative damage in the DNA of WBC of cancer patients compared with healthy controls.

Methods:

Two generally overlooked types of DNA damage, the formamide modification and the thymine glycol modification, both derived from pyrimidine bases, were assayed as markers of oxidative stress. Damage levels were measured in the DNA of WBC of ovarian cancer patients and of healthy controls.

Results:

The levels of both modifications were higher in ovarian cancer patients than in healthy controls although in the case of the formamide modification age could not be ruled out as a factor.

Conclusion:

Our results in combination with other published measurements of oxidative DNA damage support the hypothesis that oxidative damage, on average, is higher in WBC of cancer patients than in healthy controls.

Temporal changes in retinal thickness after removal of the epiretinal membrane

PURPOSE

We aimed to study the temporal aspects of the postoperative reduction of retinal thickness in eyes with epiretinal membrane after vitrectomy with peeling of the epiretinal membrane and internal limiting membrane.

METHODS

In a retrospective study performed as a non-comparative, interventional case series, 16 eyes from 15 patients with idiopathic epiretinal membrane who underwent vitrectomy and removal of the epiretinal membrane were followed up using optical coherence tomography measurements. Retinal thickness in the macular area was assessed by the foveal thickness and macular volume in a circle 6 mm in diameter.

RESULTS

Scattergrams of the foveal thickness and macular volume were best fitted with exponential curves. The average time constants of the exponential curve for foveal thickness and macular volume changes were 31 days (range 4-109 days) and 36 days (range 5-100 days), respectively. The average expected final values for foveal thickness and macular volume were 334 microm (range 206-408 microm) and 7.53 mm(3) (range 6.57-8.66 mm(3)), respectively, which were significantly greater than those in normal controls (p < 0.0001, t-test).

CONCLUSIONS

Retinal thickness decreases rapidly immediately after surgical removal of the epiretinal membrane and the reduction rate gradually slows thereafter. Approximation of the exponential curve provides an estimation of final retinal thickness after surgical removal of the epiretinal membrane; final thickness is expected to be greater than in normal eyes.

Lack of association between p53 gene polymorphisms and primary open angle glaucoma in the Japanese population

PURPOSE

To assess whether tumor protein p53 gene (p53) polymorphisms are associated with primary open angle glaucoma (POAG) in the Japanese population.

METHODS

Four hundred and twenty-five Japanese patients with POAG, including normal tension glaucoma (NTG, n=213) and high tension glaucoma (HTG, n=212) and 189 control subjects without glaucoma were analyzed for two p53 polymorphisms (rs1042522; a G-->C substitution at codon 72 in exon 4 and rs59758982; a 16 base pair insertion in intron 3) using allele specific primer PCR and a pyrosequencing technique respectively. The genotypic and allelic frequencies were compared between NTG or HTG patients and control subjects.

RESULTS

No significant difference (NTG versus control, p=0.99, and HTG versus control, p=0.69, chi(2) test) was observed regarding the p53 genotype frequencies at codon 72 between the NTG (GG: 43.2%, GC: 44.6%, CC: 12.2%) or HTG (GG: 40.1%, GC: 48.1%, CC: 11.8%) patients and the control subjects (GG: 43.9%, GC: 43.9%, CC: 12.2%). In addition, there was no significant difference (NTG versus control, p=0.94; and HTG versus control, p=0.66, Fisher's exact test) in the p53 allele frequencies at codon 72 between the NTG (G allele: 65.5%, C allele: 34.5%) or HTG (G allele: 64.2%, C allele: 35.8%) patients and the control subjects (G allele: 65.9%, C allele: 34.1%). No 16 base pair insertion in intron 3 was found in this study.

CONCLUSION

p53 polymorphisms were not associated with POAG in the Japanese population. Further studies in the other ethnic populations should therefore be performed to elucidate whether the p53 intron 3 insertion polymorphism is a genetic risk factor for POAG, because the intron 3 insertion polymorphism occurs very rarely in the Japanese population.

A new arylating agent, 2-carboxy-4,6-dinitrochlorobenzene. Reaction with model compounds and bovine pancreatic ribonuclease

The reagent 2-carboxy-4,6-dinitrochlorobenzene (CDNCB) reacts with the imino, amino and sulfhydryl groups of model compounds. At pH 8.2, sulfhydryl groups react much faster than do amines. N alpha-Acetylhistidine, N alpha-acetyltyrosine and N alpha-acetyltryptophan do not react. Poly(L-Lysine) and poly(DL-lysine) react about 50 times as fast as does N alpha-acetyllysine. A dichloroanalog, 6-carboxy-2,4-dinitro-1,3-dichlorobenzene, shows stepwise reactivity with amines. With bovine pancreatic ribonuclease, which contains no sulfhydryl, CDNCB reacts preferentially with the epsilon-amino of Lys-41 at 450 times the rate with the epsilon-amino of N alpha-acetyllysine. The preferential reactivity at Lys-41 is discussed in relation to the pK of Ly-41, the cationic character of the active site cleft, and the mechanism of RNAase action on substrates.

CEACAM1 and the regulation of mucosal inflammation

Inflammatory bowel disease (IBD) is characterized by unrestrained T-cell activation that results in the production of a variety of inflammatory cytokines and other mediators. Understanding the mechanisms of T-cell regulation is therefore of significant importance to IBD and other forms of dysregulated-mucosal inflammation. An area that is of significant interest are the cell autonomous mechanisms of T-cell regulation through proteins that have natural inhibitory functions when expressed on T lymphocytes. One such molecule is carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1). CEACAM1 is primarily an activation-induced cell-surface molecule that functions as a co-inhibitory receptor. Homophilic ligation of CEACAM1 on T cells leads to a signaling mechanism, which results in inhibition of a broad range T-cell functions. CEACAM1 therefore represents a new potential therapeutic target in the treatment of IBD.

Association of Toll-like receptor 4 gene polymorphisms with normal tension glaucoma

PURPOSE

Toll-like receptor 4 (TLR4) is a transmembrane receptor that mediates immune responses to exogenous and endogenous ligands and interacts with heat shock proteins, which are reportedly involved in normal tension glaucoma (NTG). This study was undertaken to investigate whether TLR4 polymorphisms are associated with NTG.

METHODS

Two hundred fifty Japanese patients with NTG and 318 Japanese healthy control subjects were recruited. Eight single-nucleotide polymorphisms (SNPs) in the TLR4 gene were genotyped, and allelic and phenotypic diversity was assessed between cases and control subjects.

RESULTS

Strong linkage disequilibrium was observed among all SNPs (D' >or= 0.85), which were located in one haplotype block. With respect to allelic diversity, the minor allele of three SNPs (rs10759930, rs1927914, and rs7037117) carried a significantly increased risk of NTG. With regard to genotypic diversity, individuals with the minor allele of six SNPs (rs10759930, rs1927914, rs1927911, rs12377632, rs2149356, and rs7037117) had a 1.47- to 1.65-fold increased risk of NTG. rs7037117, located in the 3'-untranslated region of TLR4, was most strongly associated with NTG, and when incorporated into a haplotype with rs10759930, the strongest association was detected (P = 0.0038, P(c) = 0.0095).

CONCLUSIONS

Multiple SNPs in the TLR4 gene are associated with the risk of NTG. This finding suggests that the ligands and/or cytokines involved in the TLR4 signaling network may be risk factors for the development of NTG.

Association of LOC387715 A69S with vitreous hemorrhage in polypoidal choroidal vasculopathy

PURPOSE

To investigate whether the LOC387715 polymorphism is associated with polypoidal choroidal vasculopathy (PCV) and with vitreous hemorrhage (VH), one of the most severe clinical phenotypes, in the Japanese population.

DESIGN

Cross-sectional case-control association study.

METHODS

One hundred and nine Japanese patients with PCV, composed of nine patients associated with VH (VH group) and 100 patients without VH (non-VH group), and 85 control subjects were analyzed for the LOC387715 polymorphism (rs = 10490924), using denaturing high-performance chromatography.

RESULTS

There was a significant difference in the T allele frequency between PCV patients and control subjects (P < .0001). In comparison with wild-type homozygosity (GG), homozygosity for the at-risk allele genotype (TT) increased the likelihood for PCV 8.4-fold (3.6 to 19.5, 95% confidence interval [CI]) and heterozygosity for the at-risk allele genotype (TG) increased the likelihood for PCV 4.0-fold (1.9 to 8.4, 95% CI). There was a significant difference in the genotypic frequency at the LOC387715 site between the VH and non-VH groups (P = .0099, Chi-square test) with the TT genotype occurring in 88.9% in the VH group and 37.0% in the non-VH group. The frequency of the T allele in the VH group was significantly greater than that in the non-VH group (0.944 vs 0.610; P = .0039, Fisher exact test).

CONCLUSIONS

The LOC387715 polymorphism is associated with PCV and clinical severity in the subgroups of PCV in the Japanese population.

Acute impact of volcanic ash on asthma symptoms and treatment

Information about the impacts of disasters on health is useful for establishing hazard prediction maps and action plans of disaster management. This study aims at learning effective asthma management from the volcano disaster of Mount Asama eruption in Japan on September 1, 2004. We conducted a cross-sectional study to assess the acute impact of volcanic ash on asthma symptoms and their treatment changes by using a questionnaire completed by 236 adult asthmatic patients and their physicians. In the ashfall over 100g/m2 area, 42.9 percent of asthma patients suffered exacerbations, PEF decreased, asthma treatments increased, and inhalation of beta2 stimulants was used most for exacerbated asthma. Compared to severe asthma patients, mild and moderate asthma patients were most at risk. Severe asthma patients were not affected since most of them knew their asthma status was severe, and did not go outside and kept windows closed. Deteriorated asthma symptoms of wheezing, chest tightness and cough appeared in the ashfall over 100g/m2 area. Ash contained inhalable 10microm diameter particles, and included high concentrations of airway toxic substrates of silica. These data suggest that ashfall over 100 g/m2 is harmful, access to these areas by asthma patients needs to be restricted, and these areas need to improve asthma treatment. In addition, the increase in the proportion of asthma patients with wheeze and cough are diagnostic clues for ash-induced asthma in affected areas, and can be used by doctors to tell whether patients are receiving sufficient asthma treatment.

Release of vitreomacular traction following retinal photocoagulation in an eye with branch retinal vein occlusion

Infrequently, vitreomacular traction is released through the spontaneous development of complete posterior vitreous detachment (PVD). PVD caused by laser photocoagulation has also been reported. A 62-year-old woman with ischemic branch retinal vein occlusion showed decreased vision in the affected eye due to vitreomacular traction. We performed laser photocoagulation in the ischemic retinal area in the hope of eliminating vitreomacular traction through laser-induced PVD. Forty days later, her vision improved and the release of vitreomacular traction was observed, associated with PVD. Optical coherence tomography demonstrates clearly the change of vitreomacular interface before and after photocoagulation.

[Automated static perimetry in 5 eyes with multiple evanescent white dot syndrome]

PURPOSE

Multiple evanescent white dot syndrome (MEWDS) is a self-limiting disease in which reduced visual acuity and retinal changes recover without treatment. It also shows visual field defects including an enlarged blind spot of Mariotte. However the final outcome of the field change has rarely been documented. We therefore retrospectively studied the visual field change in eyes with MEWDS by reviewing the multiple results of automated static perimetry recorded in the clinical course of the disease.

SUBJECTS

We reviewed the clinical course of five eyes with MEWDS using the multiple recordings of the Humphrey central 30-2 program taken during their clinical course.

RESULTS

The initial findings of perimetry included an enlarged blind spot of Mariotte, depression of the central field, and paracentral scotoma. These field defects recovered within 2 weeks to 4 months.

CONCLUSION

Visual field defects as well as vision and retinal changes recover without treatment in eyes with MEWDS.

The OPA1 gene polymorphism is associated with normal tension and high tension glaucoma

PURPOSE

To assess whether genetic polymorphisms of optic atrophy 1 (OPA1) are associated with primary open-angle glaucoma (POAG).

DESIGN

Prospective case control association study.

METHODS

Japanese patients with normal tension glaucoma (NTG, n = 194), and high tension glaucoma (HTG, n = 191), and 185 control subjects were analyzed for the OPA1 intervening sequence (IVS) 8+4 cystosine thymine (C/T) and IVS 8+32 thymine cystosine (T/C) polymorphisms using pyrosequencing technique.

RESULTS

There was a significant difference in the OPA1 IVS 8 +32 T/C genotype frequencies between the NTG patients and control subjects (P = .0074), and the frequency of the cystosine (C) allele was significantly higher in the NTG patients compared with the control subjects (19.3% vs 11.6%, P = .0036). Adjusted for age, gender, refractive error, and intraocular pressure, an almost two-fold increased risk of NTG (P = .004, odds ratio 2.27, 95% confidence interval 1.30 to 3.97) was found with the OPA1 IVS 8 +32 C allele. Although there was no significant difference in the OPA1 IVS 8 +32 T/C genotype frequencies between the HTG patients and control subjects (P = .24), the age at the time of diagnosis (53 +/- 11.0 years, median value +/- median absolute deviation) in the HTG patients with the OPA1 IVS 8 +32 C allele was significantly younger than that (57 +/- 12.0 years) in the HTG patients without C allele (P = .048).

CONCLUSIONS

The OPA1 IVS 8 +32 T/C polymorphism is associated with NTG, and may be used as a marker for this disease association. This polymorphism also influences the phenotypic feature in patients with HTG and should be considered to be a genetic risk factor not only for NTG, but also for HTG.

Methylenetetrahydrofolate reductase gene polymorphisms c.677C/T and c.1298A/C are not associated with open angle glaucoma

PURPOSE

To assess whether or not the c.677C/T and c.1298A/C genetic polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene are associated with open angle glaucoma (OAG).

METHODS

Genomic DNA was examined in a cohort of 131 Japanese patients with normal tension glaucoma (NTG), 133 patients with primary open angle glaucoma (POAG), and 106 control subjects. The mean age at the time of blood sampling was 62.8+/-13.3 years (mean+/-SD) in the patients with NTG, 61.8+/-15.4 years in the patients with POAG, and 65.0+/-10.5 years in the control subjects. MTHFR c.677C/T and c.1298A/C genotype and allele frequencies were determined using pyrosequencing analysis, and the findings were compared between the OAG patients and control subjects. The frequencies of compound MTHFR c.677C/T and c.1298A/C genotypes were also compared between OAG patients and control subjects.

RESULTS

No significant differences were observed (p>0.05, chi2 test or Fisher's exact test) regarding the MTHFR c.677C/T genotype (TT: 14.5%, CT: 44.3%, CC: 41.2% for patients with NTG; TT: 20.3%, CT: 41.4%, CC: 38.3% for patients with POAG; TT: 17.9%, CT: 36.8%, CC: 45.3% for control subjects) and c.1298A/C (CC: 0%, AC: 38.9%, AA: 61.1% for patients with NTG; CC: 2.3%, AC: 32.3%, AA: 65.4% for patients with POAG; CC: 0.9%, AC: 41.5%, AA: 57.6% for control subjects). There were no allele frequencies between the NTG or POAG patients and the control subjects. In addition, no significant differences (p>0.05, chi2 test) were found in the frequencies of the compound MTHFR c.677C/T and c.1298A/C genotypes between the NTG or POAG patients and the control subjects.

CONCLUSIONS

The MTHFR c.677C/T and c.1298A/C polymorphisms were not found to be associated with NTG and POAG. Further studies in the different ethnic populations should be performed to elucidate the relationship between MTHFR and OAG.

Phase II study of the efficacy of gefitinib in patients with non-small cell lung cancer with the EGFR mutations

7183

Purpose: Recent studies have indicated that the mutations of epidermal growth factor receptor (EGFR) were associated with sensitivity of non-small cell lung cancer (NSCLC) to gefitinib, an EGFR tyrosine kinase inhibitor. The clinical objective of this study was to prospectively evaluate the efficacy of gefitinib in patients with stageIII/IV NSCLC that had the EGFR mutations. Methods: Genomic DNA was extracted from tumor specimens and EGFR mutations in exon 19 and 21 were analyzed by direct sequencing. Patients with stageIII/IV NSCLC who had the EGFR mutations were treated with gefitinib (250mg) orally. Response, survival data and toxicity were assessed. Results: From Nov. 2004 to Dec 2005, 14 patients with the EGFR mutations received gefitinib (median age: 67 years; 2 males, 12 females; 1 smokers, 13 non-smokers; all adenocarcinomas). Two patients discontinued gefitinib and came off study because of interstitial pneumonitis (grade 3) and acne (grade 3), respectively. Response data are available for 12 patients. Two achieved a complete response (CR), seven exhibited a partial response (PR) and three had stable disease (SD). Response rate and disease control rate were 75% and 100%, respectively. There were no grade 3/4 toxicities in these 12 patients. All patients were alive during median follow-up period of 8 months (range 1–13 months). Conclusions: The EGFR mutations could be an excellent predictor of response to gefitinib in NSCLC.

No significant financial relationships to disclose.

The apolipoprotein E gene polymorphism is associated with open angle glaucoma in the Japanese population

PURPOSE

To assess whether genetic polymorphisms of the apolipoprotein E (APOE) gene are associated with open angle glaucoma (OAG) in the Japanese population.

METHODS

Genomic DNA was examined in a cohort of 310 Japanese patients with OAG and 179 control subjects. The average age was 63.5+/-14.4 years (mean+/-SD) for the OAG patients and 65.5+/-11.6 years for the control subjects. The presence or absence of OAG in patients and controls was based on clinical examination and/or ophthalmic records. The APOE allele frequency (epsilon2, epsilon3, and epsilon4 alleles) was studied by restriction fragment length polymorphism, and compared between OAG patients and control subjects. The association between the intraocular pressure (IOP) and the APOE alleles was also evaluated.

RESULTS

There was a significant difference in the APOE genotype frequencies between these groups (p=0.0006 chi2 test). The frequencies of the epsilon2 and epsilon4 alleles were significantly lower in the OAG patients (epsilon2: 2.6%; epsilon4: 6.0%) compared to the control subjects (epsilon2: 5.0%, p=0.048; epsilon4: 10.6%, p=0.012; Fisher's exact test). The frequency of the epsilon3 allele was significantly higher in the OAG patients (91.4%) compared to the control subjects (84.4%, p=0.0010; Fisher's exact test). Adjusted for age, gender, and IOP, an appropriate three fold reduction in OAG risk (odds ratio [OR] 0.29, 95% confidence interval [CI] 0.10 to 0.80; p=0.018) was found with the epsilon2 allele and a two fold increased risk of OAG (OR 1.97, 95% CI 1.06 to 3.67; p=0.033) was found with the epsilon3 allele. The maximum IOP (18.3+/-6.0 mm Hg) in patients with the epsilon4 allele was significantly lower than that (21.3+/-9.1 mm Hg) in patients without the epsilon4 allele (p=0.006, Student's t-test).

CONCLUSIONS

The APOE gene polymorphism is associated with OAG in the Japanese population. Further studies in the other ethnic populations should be performed to elucidate the relationship between APOE and OAG.

ADDITIONAL INTRAVITREAL GAS INJECTION IN THE EARLY POSTOPERATIVE PERIOD FOR AN UNCLOSED MACULAR HOLE TREATED WITH INTERNAL LIMITING MEMBRANE PEELING

PURPOSE

To study the efficacy of additional intravitreal gas injection for unclosed macular holes within 2 weeks after surgery with internal limiting membrane peeling.

METHODS

We reviewed the results for five consecutive eyes receiving additional intravitreal gas injection for unclosed macular holes within 2 weeks after initial macular hole surgery with internal limiting membrane peeling. The initial surgery consisted of standard pars plana vitrectomy with phacoemulsification and intraocular lens implantation, indocyanine green-assisted peeling of the retinal internal limiting membrane, and fluid-gas exchange with 20% sulfur hexafluoride. The patients were instructed to assume face down positioning for > or =7 days after surgery. If an unclosed macular hole was found after the residual gas volume decreased to <30% of the eyeball volume, fluid-gas exchange was performed using 15% octafluoropropane.

RESULTS

All five eyes receiving additional intravitreal gas 7 to 14 days after vitrectomy had complete macular hole closure with macular flattening, as shown by optical coherence tomography 1 month after the additional gas injection. Visual acuity improved (range, 20/100 to 20/30). A minimum of 9 months of follow-up revealed no reopening or serious complications.

CONCLUSION

Additional gas injection during the early postoperative period is recommended for eyes with unclosed macular holes that have undergone vitrectomy with internal limiting membrane peeling.

Personality Assessment Based on the Five-factor Model of Personality Structure in Patients with Primary Open-Angle Glaucoma

PURPOSE

Several characteristic personality types have been reported for glaucoma patients in previous studies. However, none of the previous studies used a common structural theory of personality. In this study, we conducted a multicenter cross-sectional case-control study using the recently established five-factor model of personality structure.

METHODS

Personality was evaluated using the Neuroticism Extraversion Openness Five-Factor Inventory (NEO-FFI), which is a questionnaire specifically designed to test the five-factor model of personality: neuroticism (N), extraversion (E), openness (O), agreeableness (A), and conscientiousness (C). Eligible questionnaires were obtained from 196 patients with primary open-angle glaucoma (POAG) (99 men, 97 women) and 223 reference subjects with no ocular disease except cataract (87 men, 136 women). The mean score of each NEO-FFI factor for POAG patients was compared to the scores for the reference subjects.

RESULTS

Compared with the reference subjects, the mean N score was significantly higher (P = 0.013), the mean scores for A and C were significantly lower (P = 0.007 and P = 0.001, respectively), and the mean E score tended to be lower (P = 0.055) in male POAG patients. The mean E score was significantly lower (P = 0.023) in female POAG patients.

CONCLUSIONS

Characteristic personality traits were noted in POAG patients, and a more significant relationship was found between personality and glaucoma in men than in women.

Visual outcome in central retinal and branch retinal artery occlusion

PURPOSE

To study retrospectively the presenting visual acuity and the visual outcome in patients with central retinal artery occlusion (CRAO) and in patients with branch retinal artery occlusion (BRAO).

METHODS

We studied the visual acuity and outcome in 23 patients (23 eyes) with CRAO and in 30 patients (30 eyes) with BRAO that met the inclusion criteria: a funduscopic appearance of retinal whitening, a delay in arterial dye filling in a fluorescein angiogram, the first examination in our hospital within 7 days of onset, and a minimum follow-up period of 90 days.

RESULTS

Both presenting acuity and final acuity were far worse in patients with CRAO than in patients with BRAO. A final acuity worse than 0.1 was observed in 14 of the 23 (61%) patients with CRAO and in only 1 of the 30 (3%) patients with BRAO. Only 5 of the 23 (22%) patients with CRAO and 24 of the 30 (80%) patients with BRAO showed a final acuity of 0.5 or better.

CONCLUSION

Visual acuity in patients with CRAO is poor at presentation, and the prognosis is generally poor, with a few exceptions. In contrast, the visual acuity in patients with BRAO is far better both at presentation and at the final visit.

Allelic losses on chromosome 3p are accumulated in relation to morphological changes of lung adenocarcinoma

We performed allelotyping analysis at nine regions on chromosome 3p using 56 microdissected samples from 23 primary lung adenocarcinomas to examine the process of progression within individual lung adenocarcinoma with various grades of differentiation. Identical allelic patterns among various grades of differentiation were found in eight cases. Accumulation of allelic losses from high to lower differentiated portions was found in seven cases and accumulation of allelic losses from low to higher differentiated portions was found in five cases. Various allelic patterns among various grades of differentiation were found in three cases. These results suggested that allelic losses on 3p play an important role in morphological changes of lung adenocarcinomas. We also investigated the relationship between allelic losses on 3p and histological subtypes of lung adenocarcinoma. The frequencies of allelic losses at 3p14.2 and telomeric region of 3p21.3 were higher in papillary type tumour (nine out of 14, 64% and 11 out of 15, 73%) than in bronchioloalveolar carcinoma-type tumour (one out of 8, 13%; P=0.031 and four out of 12, 33%; P = 0.057). These results indicated that allelic losses at 3p14.2 and telomeric region of 3p21.3 are related to pattern of the proliferation of lung adenocarcinoma.