NBS1 recruits RAD18 via a RAD6-like domain and regulates Pol η-dependent translesion DNA synthesis.

Translesion DNA synthesis, a process orchestrated by monoubiquitinated PCNA, is critical for DNA damage tolerance. While the ubiquitin-conjugating enzyme RAD6 and ubiquitin ligase RAD18 are known to monoubiquitinate PCNA, how they are regulated by DNA damage is not fully understood. We show that NBS1 (mutated in Nijmegen breakage syndrome) binds to RAD18 after UV irradiation and mediates the recruitment of RAD18 to sites of DNA damage. Disruption of NBS1 abolished RAD18-dependent PCNA ubiquitination and Polη focus formation, leading to elevated UV sensitivity and mutation. Unexpectedly, the RAD18-interacting domain of NBS1, which was mapped to its C terminus, shares structural and functional similarity with the RAD18-interacting domain of RAD6. These domains of NBS1 and RAD6 allow the two proteins to interact with RAD18 homodimers simultaneously and are crucial for Polη-dependent UV tolerance. Thus, in addition to chromosomal break repair, NBS1 plays a key role in translesion DNA synthesis.

Clinical introduction of Monte Carlo treatment planning for lung stereotactic body radiotherapy.

The purpose of this study was to investigate the impact of Monte Carlo (MC) calculations and optimized dose definitions in stereotactic body radiotherapy (SBRT) for lung cancer patients. We used a retrospective patient review and basic virtual phantom to determine dose prescriptions. Fifty-three patients underwent SBRT. A basic virtual phantom had a gross tumor volume (GTV) of 10.0 mm with equivalent water density of 1.0 g/cm3, which was surrounded by equivalent lung surrounding the GTV of 0.25 g/cm3. D95 of the planning target volume (PTV) and D99 of the GTV were evaluated with different GTV sizes (5.0 to 30.0 mm) and different lung densities (0.05 to 0.45 g/cm3). Prescribed dose was defined as 95% of the PTV should receive 100% of the dose (48 Gy/4 fractions) using pencil beam (PB) calculation and recalculated using MC calculation. In the patient study, average doses to the D95 of the PTV and D99 of the GTV using the MC calculation plan were 19.9% and 10.2% lower than those by the PB calculation plan, respectively. In the phantom study, decreased doses to the D95 of the PTV and D99 of the GTV using the MC calculation plan were accompanied with changes GTV size from 30.0to 5.0 mm, which was decreased from 8.4% to 19.6% for the PTV and from 17.4%to 27.5% for the GTV. Similar results were seen with changes in lung density from 0.45 to 0.05 g/cm3, with doses to the D95 of the PTV and D99 of the GTV were decreased from 12.8% to 59.0% and from 7.6% to 44.8%, respectively. The decrease in dose to the PTV with MC calculation was strongly dependent on lung density. We suggest that dose definition to the GTV for lung cancer SBRT be optimized using MC calculation. Our current clinical protocol for lung SBRT is based on a prescribed dose of 44 Gy in 4 fractions to the GTV using MC calculation.

Preproghrelin gene polymorphisms in obese Japanese women. Minor homozygotes are light eaters, do not prefer protein or fat, and apparently have a poor appetite.

Preproghrelin gene single-nucleotide polymorphisms are possible predisposing factors to obesity and other metabolic syndromes. To study the correlation between genotypes and obesity, we recruited 117 obese Japanese women (BMI, 25.0-41.1; average, 31.1). Minor homozygotes for five preproghrelin gene polymorphisms, namely, -1500C>G (rs3755777), -1062G>C (rs26311), -994C>T (rs26312) (promoter region), Leu72Met (rs696217) (exon 2), and +3056T>C (rs2075356) (intron 2), had high values of total and visceral fat areas, waist circumference, and BMI, indicating significant correlation of the polymorphisms with obesity and fat metabolism. Here, we studied the relationship between the genotypes and dietary tendency. Self-administered Diet History Questionnaire showed that total food intake, sugar, and dairy product intake were low in +3056C/C women. Their energy, protein, fat, and meat intake was also low. Energy balance calculation showed considerably reduced fat and protein consumption. Dietary habits were surveyed using Sakata's Questionnaire on Eating Behavior. Of the genotypes, -1062C/C women showed low scores for "motivation for eating" and "eating because of stress or something else." Thus, surprisingly, it was revealed that minor homozygotes for preproghrelin gene polymorphisms were light eaters, did not prefer fat or protein, and apparently had a poor appetite, although they were predisposed to obesity.

Caffeine abolishes the ultraviolet-induced REV3 translesion replication pathway in mouse cells.

When a replicative DNA polymerase stalls upon encountering a photoproduct on the template strand, it is relieved by other low-processivity polymerase(s), which insert nucleotide(s) opposite the lesion. Using an alkaline sucrose density gradient sedimentation technique, we previously classified this process termed UV-induced translesion replication (UV-TLS) into two types. In human cancer cells or xeroderma pigmentosum variant (XP-V) cells, UV-TLS was inhibited by caffeine or proteasome inhibitors. However, in normal human cells, the process was insensitive to these reagents. Reportedly, in yeast or mammalian cells, REV3 protein (a catalytic subunit of DNA polymerase ζ) is predominantly involved in the former type of TLS. Here, we studied UV-TLS in fibroblasts derived from the Rev3-knockout mouse embryo (Rev3KO-MEF). In the wild-type MEF, UV-TLS was slow (similar to that of human cancer cells or XP-V cells), and was abolished by caffeine or MG-262. In 2 cell lines of Rev3KO-MEF (Rev3(-/-)p53(-/-)), UV-TLS was not observed. In p53KO-MEF, which is a strict control for Rev3KO-MEF, the UV-TLS response was similar to that of the wild-type. Introduction of the Rev3 expression plasmid into Rev3KO-MEF restored the UV-TLS response in selected stable transformants. In some transformants, viability to UV was the same as that in the wild-type, and the death rate was increased by caffeine. Our findings indicate that REV3 is predominantly involved in UV-TLS in mouse cells, and that the REV3 translesion pathway is suppressed by caffeine or proteasome inhibitors.

A large intermediate domain of vertebrate REV3 protein is dispensable for ultraviolet-induced translesion replication.

DNA polymerase ζ (pol ζ) is involved in translesion replication (translesion synthesis, TLS) and plays an essential role in embryogenesis. In adults, pol ζ triggers mutation as a result of error-prone TLS and causes carcinogenesis. The catalytic subunit of pol ζ, REV3, is evolutionarily conserved from yeast and plants to higher eukaryotes. However, the structures are notably different: unlike that in yeast REV3, a large intermediate domain is inserted in REV3 of humans and mice. The domain is mostly occupied with noncommittal structures (random coil…etc.); therefore, its role and function are yet to be resolved. Previously, we reported deficient levels of ultraviolet (UV)-induced TLS in fibroblasts derived from the Rev3-knockout mouse embryo (Rev3KO-MEF). Here, we constructed a mouse Rev3-expressing plasmid with a deleted intermediate domain (532-1793 a.a,) and transfected it into Rev3KO-MEF. The isolated stable transformants showed comparable levels of UV-sensitivity and UV-TLS activity to those in wild-type MEF, detected using an alkaline sucrose density gradient sedimentation. These results indicate that the intermediate domain is nonessential for UV-induced translesion replication in cultured mouse cells.

Proteasome inhibitors remarkably prevent translesion replication in cancer cells but not normal cells.

When a replicative DNA polymerase encounters a lesion on the template strand and stalls, it is replaced with another polymerase(s) with low processivity that bypasses the lesion to continue DNA synthesis. This phenomenon is known as translesion replication or replicative bypass. Failing this, the cell is increasingly likely to undergo apoptosis. In this study, we found that proteasome inhibitors prevent translesion replication in human cancer cells but not in normal cells. Three proteasome inhibitors, MG-132, lactacystin, and MG-262, inhibited UV-induced translesion replication in a wide range of cancer cell lines, including HeLa, HGC-27, MCF-7, HepG2, WiDr, a malignant melanoma, an acute lymphoblastic leukemia, and a multiple myeloma cell line; irrespective of cell origin, histological type, or p53 status. In contrast, these inhibitors had little or no influence on normal fibroblasts (NB1RGB and TIG-1) or a normal liver mesenchymal (LI90) cell line. Among the DNA-damaging antineoplastic agents, cisplatin caused a UV-type translesion reaction; the proteasome inhibitors delayed cisplatin-induced translesion replication in cancer cell lines but had only a weak effect on normal cell lines. Therefore, translesion replication would be an effective target of proteasome inhibitors for cancer chemotherapy by which cancer cells can be efficiently sensitized to DNA-damaging antineoplastic agents, such as cisplatin.

A novel Rad18 function involved in protection of the vertebrate genome after exposure to camptothecin.

In Saccharomyces cerevisiae, Rad18 functions in post-replication repair pathways, such as error-free damage bypass involving Rad30 (Poleta) and error-prone damage bypass involving Rev3/7 (Polzeta). Chicken DT40 RAD18(-/-) cells were found to be hypersensitive to camptothecin (CPT), while RAD30(-/-) and REV3(-/-) cells, which are defective in translesion DNA synthesis, were not. RAD18(-/-) cells also showed higher levels of H2AX phosphorylation and chromosomal aberrations, particularly chromosomal gaps and breaks, upon exposure to CPT. Detailed analysis by alkaline sucrose density gradient centrifugation revealed that RAD18(-/-) and wild type cells exhibited similar rates of elongation of newly synthesized DNA in the presence or absence of low concentrations of CPT but that DNA breaks frequently occurred on both parental and nascent strands within 1h after a brief exposure to an elevated concentration of CPT, with more breaks induced in RAD18(-/-) cells than in wild type cells. These data suggest a previously unanticipated role for Rad18 in dealing with replication forks upon encountering DNA lesions induced by CPT.

Measurement of DNA synthesis and strand breaks using alkaline sucrose density gradient centrifugation.

Alkaline sucrose density gradient (ASDG) centrifugation is probably an only method to detect elongation of "pulse-labeled" replication products in cells. If the cells are pulse-labeled after being exposed to some DNA-damaging agents, their "post-replication repair" can be measured by ASDG technique. With non-damaged cells, normal replication in replicon size can be observed, too. In addition, the method is also applicable to measure single strand breaks. We have modified this classical method to reproducibly detect very long single-stranded DNA at the megabase level. Here, the protocols are optimized to DT40 cells.

Environmental influence on the measurement of exhaled nitric oxide concentration in school children: special reference to methodology.

INTRODUCTION: Measuring exhaled nitric oxide (eNO) is a noninvasive and useful method for evaluating the correlation between airway inflammation and air pollution. The method is being used in studies; however, the effects of polluted air on eNO values are poorly understood. If polluted air significantly affects eNO concentrations, then it would be hard to evaluate the concentration of eNO, particularly in epidemiological measurements to detect the effects of airway inflammation, such as that in bronchial asthma. Thus, we hypothesized that short-term exposure to air pollution affects eNO values. PURPOSE: To study the effects of environmental nitrogen oxides on the measurement of eNO concentration. SUBJECTS AND METHODS: A total of 19 school children who lived on a large street with heavy traffic with random allocation were studied. Subjects with bronchial asthma were identified with a questionnaire. Suspended particulate matter. including particulate matter with an aerodynamic diameter < or =2.5 microm (PM(2.5)), optical black carbon, nitric oxide (NO), nitric dioxide (NO(2)), and nitrogen oxides (NO(X)), were measured at a fixed place along the street every hour for 11 consecutive days. The concentrations of NO and NO(2) for each subject were measured by an individual 2-pyenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl sampler, and the concentration of eNO was measured with the off-line method. RESULTS: Of 19 subjects, 3 were found to have bronchial asthma. The level of each pollutant for 11 days peaked during the mornings (6;9 a.m.) and evenings (6;9 p.m.) due to traffic jams; average eNO values in healthy subjects and those with asthma were 27.1 +/- 9.7 and 57.7 +/- 18.6 ppb (p=0.098), respectively. It was found that the eNO value remained high when the mean values of various pollutants remained high for 8 hours before the measurements. It was estimated that the mean eNO values increased by 1.08 ppb (95% CI: 0.72;1.45) when the mean NO(X) value for the previous 8 hours reached approximately 10 ppb. CONCLUSION: We conclude that short-term exposure to polluted air of at least 8 hours before measurement affects eNO values. Therefore, caution should be exercised when measuring eNO value in epidemiological studies.

Translesion replication in cisplatin-treated xeroderma pigmentosum variant cells is also caffeine-sensitive: features of the error-prone DNA polymerase(s) involved in UV-mutagenesis.

Patients with xeroderma pigmentosum variant (XP-V) have a higher risk to skin cancer and XP-V cells are extremely mutable by ultraviolet (UV). The defective gene encodes a DNA polymerase (Poleta) which catalyzed relatively accurate translesion synthesis past the cyclobutane dimer of UV-lesions instead of the replicative polymerase(s) that stalled just before the lesion. Pulse-chase studies have shown that translesion replication in XP-V cells is delayed, but does not completely cease. Taking these results together, error-prone polymerase(s) are plausively involved in the UV-mutagenesis in XP-V devoid of Poleta. However, less is known about the polymerase(s) in vivo. Using an alkaline sucrose density gradient centrifugation (ASDG) technique, translesion replication is detected in the two XP-V strains XP30RO and XP115LO. As reported by Lehmann et al. [Proc. Natl. Acad. Sci. U.S.A. 72 (1975): 219] in XP-V; (i) smaller replication products were accumulated after UV irradiation; (ii) the elongation of these products was delayed; (iii) the elongation was markedly inhibited by caffeine. XP-V cells UV-irradiated at mid-S phase were normally S-arrested, and no "override" by caffeine (i.e. abrogation of the S-checkpoint) was observed by flow cytometry, suggesting that caffeine does not act via cdc kinase here; (iv) butylphenyldeoxyguanosine (BuPGdR) inhibited elongation of replication products only in UV-irradiated XP-V cells; (v) dideoxycytidine or dideoxyinosine had no effect on this process in either normal or XP-V cells. Next, similar phenomena to UV (all of above i to v) were observed also in cisplatin-treated XP-V cells. Pol eta was indicated to participate in cisplatin-induced translesion replication in normal cells. Summing up the above results, the polymerase(s) which work in translesion replication in XP-V are probably BuPGdR-sensitive, insensitive to dideoxynucleotides and can bypass also cisplatin-lesions. To date, several polymerases capable of lesion-bypass synthesis have been isolated. The features presented here are quite useful for identifying the error-prone polymerase(s) involved in UV-mutagenesis.

Both generic and disease specific health-related quality of life are deteriorated in patients with underweight COPD.

This study evaluated the effects of body weight on both generic and disease-specific health-related quality of life (HRQoL) of patients with COPD. A total of 83 patients with stable COPD were enrolled (mean age: 74.6 yr, mean FEV1: 1.29 L). Patients were divided into two groups according to body mass index (BMI) (UW group: BMI < or = 20, NW group: 20 < BMI < or = 26). The degree of dyspnea and both disease-specific and generic HRQoL were compared between the two groups. An oxygen cost diagram (OCD) was used to assess the degree of dyspnea and St. George's Respiratory Questionnaire (SGRQ) and Medical Outcomes Study Short Form 36-item Questionnaire (SF-36) were used for HRQoL evaluation. The OCD was significantly lower in the UW group. Compared with the NW group, the UW group showed significant deterioration in the total score and three subscales of SGRQ. SF-36 also showed significantly worse scores for the parameters of physical functioning, role emotional, bodily pain, and general health. The results of stepwise multiple regression analysis showed that OCD, FEV1, %pred. BMI were independent variables in the total score on SGRQ. The results of stepwise multiple regression analysis also showed that OCD was an independent variable for four of eight components of SF-36, while BMI was three of eight components of SF-36. In conclusion, low body weight in patients with COPD is related to a worsening of dyspnea and deterioration of both generic and disease-specific HRQoL. The present results also indicate that nutritional intervention may be important for improving dyspnea and HRQoL in patients with COPD.

Usefulness of a linear analog scale questionnaire to measure health-related quality of life in elderly patients with chronic obstructive pulmonary disease.

OBJECTIVES: To examine the validity, discriminatory ability, and responsiveness of health-related quality-of-life (HRQoL) questionnaires using a linear analog scale (Quality of Life (QOL) scale) for chronic obstructive pulmonary disease (COPD). DESIGN: Cross-sectional and longitudinal. SETTING: Outpatient. PARTICIPANTS: One hundred two elderly subjects with mild to severe COPD. MEASUREMENTS: Scores on the QOL scale, the St. George's Respiratory Questionnaire (SGRQ), and the 36-item Short-Form Health Survey questionnaire (SF-36) and various clinical parameters were recorded. The correlations between these QOL questionnaires and various clinical parameters were then examined. The responses of 31 elderly COPD patients to the QOL scale and the SGRQ before and 3 months after the completion of a comprehensive pulmonary rehabilitation program were compared longitudinally. RESULTS: On cross-sectional study, the QOL scale showed a significant correlation with the total score and three components of the SGRQ. The QOL scale correlated significantly with all components of the SF-36, but the total SGRQ score correlated with only six components of the SF-36, excluding vitality and the mental health index. Both the QOL scale and the total score of the SGRQ correlated significantly with the oxygen cost diagram (OCD), Morale scale, 6-minute walking distance (6MWD), forced expiratory volume in 1 second, and instrumental activities of daily living (IADL) score. When subjects were divided into three groups according to disease severity (mild, moderate, severe) using American Thoracic Society guidelines, the total SGRQ score discriminated between the three groups. The QOL scale could not discriminate between mild and moderate or moderate and severe. On longitudinal study, 3 months after finishing the comprehensive pulmonary rehabilitation program, the QOL scale, the SGRQ, 6MWD, and OCD all showed significant improvement. The difference in the QOL scale after the comprehensive pulmonary rehabilitation program showed a significant correlation with changes in the SGRQ total score and the OCD but not with the 6MWD. CONCLUSION: The QOL scale is similar to more-complex questionnaires such as the SGRQ in terms of validity and responsiveness for evaluating disease-specific HRQoL in elderly COPD patients. In clinical settings, the QOL scale, as a simple questionnaire, may be useful for disease-specific HRQoL assessments in elderly COPD patients.

[A case of infected bulla caused by Mycobacterium gordonae].

A 65-year-old man was admitted to Tokyo Metropolitan Geriatric Medical Center because of dyspnea on effort, loss of appetite and general fatigue. Chest radiography on admission showed niveau formation in, and infiltration around, the bulla. Percutaneous drainage of the intrabullous fluid was performed and Mycobacterium gordonae was repeatedly cultured from it. The patient was treated with RFP, INH and CAM and the intrabullous fluid and infiltration around the bulla was markedly improved. Seven cases of pulmonary infection by M. gordonae have been reported in Japan, but this is the first case of bulla infected by this organism.

Long-term management of chronic obstructive pulmonary disease: a survey of collaboration among physicians involved in pulmonary rehabilitation in Japan.

BACKGROUND: This study evaluated the implementation of pulmonary rehabilitation (PR), and the extent of the collaboration between primary care and chest physicians involved in the management of chronic obstructive pulmonary disease (COPD) in Japan. METHODS: The survey was conducted in 2006 via post and facsimile and included all medical institutions approved by the Japan Respiratory Society. RESULTS: In total, 176 institutions responded (response rate, 27%); a PR program was conducted at 55.1% of these institutions throughout Japan, but with regional differences. The mean duration of each session in an outpatient setting was 30 min with 2 sessions per week, and the mean length of hospitalization was 2-3 weeks. Although 33% of the hospitals adopted PR programs, on a scale from none (0) to maximum achievement (100), the accomplishment score was 48. Similarly, the mean satisfaction level score for collaboration was 44. The main problem arising with regards to chest physicians' referral to general physicians was the reluctance of patients or family members (88%). Chest physicians believed that general physicians should perform early screening of patients and manage early exacerbations, including educating patients of the need to discontinue smoking. CONCLUSIONS: Most chest physicians in Japan were not satisfied with the status of long-term COPD management. PR for COPD patients and collaboration between primary care physicians and specialists remain problematic in Japan. Moreover, there are widespread regional differences in terms of implementation. Sharing and implementing appropriate clinical information with primary care physicians according to current clinical guidelines should be emphasized.

Excessive visceral fat accumulation in advanced chronic obstructive pulmonary disease.

BACKGROUND: Previous studies have suggested links between chronic obstructive pulmonary disease (COPD), cardiovascular disease, and abdominal obesity. Although abdominal visceral fat is thought to be associated with cardiovascular risk factors, the degree of visceral fat accumulation in patients with COPD has not been directly studied. The aim of this study was to investigate the abdominal visceral fat accumulation and the association between visceral fat and the severity and changes in emphysema in COPD patients. METHODS: We performed clinical and laboratory tests, including pulmonary function, dyspnea score, and the six-minute walking test in COPD patients (n = 101) and control, which included subjects with a smoking history but without airflow obstruction (n = 62). We used computed tomography to evaluate the abdominal visceral fat area (VFA), subcutaneous fat area (SFA), and the extent of emphysema. RESULTS: The COPD group had a larger VFA than the control group. The prevalence of non-obese subjects with an increased VFA was greater in the Global Initiative for Chronic Obstructive Lung Disease Stages III and IV than in the other stages of COPD. The extent of emphysema was inversely correlated with waist circumference and SFA. However, VFA did not decrease with the severity of emphysema. VFA was positively correlated with the degree of dyspnea. CONCLUSION: COPD patients have excessive visceral fat, which is retained in patients with more advanced stages of COPD or severe emphysema despite the absence of obesity.

Concerns with the health check-up system for chronic obstructive pulmonary disease on two Japanese islands.

OBJECTIVE: Early diagnosis is a key factor in the management of chronic obstructive pulmonary disease (COPD). Although mass screening is widely used, little is known about its accuracy and efficacy. This study investigated whether using spirometry during mass screening to detect COPD among community residents might be ineffective because of variability in the training and experience of examiners. PARTICIPANTS AND METHODS: Both spirometry and a self-written questionnaire-based survey, including questions designed to detect respiratory symptoms, were conducted on community residents. Two separate studies were conducted on islanders living in similar environments. Study I was performed from 2004 to 2007 on Hachijyo Island residents, while study II, with a similar study design, was performed in 2003 on Inno Island residents. RESULTS: In study I, 3,592 subjects underwent examination over the 4-year study period; of these, 378 subjects underwent repeated examinations. Approximately 25% of the subjects had respiratory symptoms. Acceptable spirometry recordings were obtained for 62.0% (2004) to 84.1% (2006) of the subjects. In study II, 167 of the 254 subjects (65.7%) had respiratory symptoms. Acceptable assessment recordings were achieved in 254 subjects (95.5%). The suitability of the recordings was influenced by the extent/level of training of the examiners and the accompanying thoracic specialists. CONCLUSION: We concluded that the effectiveness of health check-ups for COPD evaluation using spirometry was greatly influenced by the quality of the examiners, even when the subjects had respiratory symptoms. Thus, we recommend caution when screening for early signs of COPD during health check-ups.

Efficient integrated education for older patients with chronic obstructive pulmonary disease using the Lung Information Needs Questionnaire.

AIM: Education is a key issue for the long-term management of chronic obstructive pulmonary disease in older patients. We tested the hypothesis that integrated care focusing on patient information needs for self-management can improve patient information needs and health outcomes. METHODS: Patients with chronic obstructive pulmonary disease (n=102) were randomized into integrated care (group I) and usual care (group U) groups. Group I underwent a program of educational sessions for 6months (integrated education period), and then repeatedly received an individually tailored education according to the Lung Information Needs Questionnaire score. Both groups were followed up monthly for 6months. RESULTS: A total of 85 patients (mean age: 71.7years) were followed up for 12months. The total Lung Information Needs Questionnaire score was significantly better in group I than in group U at 12months (P<0.03). Activities of daily living scores were significantly improved in group I at 6months (P<0.03). The dyspnea score and the BODE index (body mass index, dyspnea, airflow obstruction and exercise capacity) were significantly improved in group I at 12months (P<0.01 and P<0.02, respectively). During the integrated education period, the frequency of hospitalization was significantly lower in group I than in group U (P=0.033). CONCLUSION: Integrated education for older patients with chronic obstructive pulmonary disease effectively improved patients' information needs, activities of daily living, dyspnea score, BODE index and reduced hospitalizations during the observed period. Geriatr Gerontol Int 2011; 11: 422-430.

Rev1, Rev3, or Rev7 siRNA Abolishes Ultraviolet Light-Induced Translesion Replication in HeLa Cells: A Comprehensive Study Using Alkaline Sucrose Density Gradient Sedimentation.

When a replicative DNA polymerase stalls upon encountering a lesion on the template strand, it is relieved by other low-processivity polymerase(s), which insert nucleotide(s) opposite the lesion, extend by a few nucleotides, and dissociate from the 3'-OH. The replicative polymerase then resumes DNA synthesis. This process, termed translesion replication (TLS) or replicative bypass, may involve at least five different polymerases in mammals, although the participating polymerases and their roles have not been entirely characterized. Using siRNAs originally designed and an alkaline sucrose density gradient sedimentation technique, we verified the involvement of several polymerases in ultraviolet (UV) light-induced TLS in HeLa cells. First, siRNAs to Rev3 or Rev7 largely abolished UV-TLS, suggesting that these 2 gene products, which comprise Polζ, play a main role in mutagenic TLS. Second, Rev1-targeted siRNA also abrogated UV-TLS, indicating that Rev1 is also indispensable to mutagenic TLS. Third, Polη-targeted siRNA also prevented TLS to a greater extent than our expectations. Forth, although siRNA to Polι had no detectable effect, that to Polκ delayed UV-TLS. To our knowledge, this is the first study reporting apparent evidence for the participation of Polκ in UV-TLS.

Emphysema on imaging is associated with quality of life in elderly patients with chronic obstructive pulmonary disease.

BACKGROUND: Limited data are available on the association between the severity of emphysema or airway narrowing, and health-related quality of life (HRQOL) in patients with chronic obstructive pulmonary disease (COPD), which has been seen to be more prevalent among elderly subjects. The aim of this study was to examine the association between HRQOL, physical parameters and structural alterations in lung of COPD patients. METHODS: Stable COPD patients (n = 125; mean age 71.0) were studied. Both the severity of emphysema, which was expressed as the extent of the low-attenuation area (LAA%), and percentage of the large airway wall area (WA%) on high-resolution computed tomography (HRCT) were compared with various parameters of the generic and HRQOL, respectively, together with pulmonary function tests and exercise capacity. RESULTS: The predicted value of forced expiratory volume in 1 s was significantly associated with both LAA% and WA%, but the diffusion capacity was strongly correlated with LAA% alone. Parameters of the generic and HRQOL, and almost all other parameters appeared to be significantly associated with LAA% alone, whereas no association was observed between WA% and QOL. CONCLUSION: We concluded that the severity of emphysema, but not that of large airway narrowing on HRCT, is associated with both generic and health-related QOL and reduced diffusion capacity. This notion might provide useful information in practice among elderly subjects who are unable to perform a spirometry.