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Background The role of smoking in nasopharyngeal carcinoma (NPC) remains uncertain, especially in endemic regions. We conducted an individual participant data (IPD) meta-analysis of prospective cohort studies to investigate the associations between smoking exposure and risk of NPC. Methods We obtained individual participant data of 334 935 male participants from six eligible population-based cohorts in NPC-endemic regions, including two each in Guangzhou and Taiwan, and one each in Hong Kong and Singapore. We used one- and two-stage approaches IPD meta-analysis and Cox proportional hazard models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of NPC for smoking exposure adjusting for age and drinking status. Results During 2 961 315 person-years of follow-up, 399 NPC evens were ascertained. Risks of NPC were higher in ever versus never smokers (HRone-stage = 1.32, 95% CI = 1.07-1.63, P = 0.0088; HRtwo-stage = 1.27, 1.01-1.60, 0.04). These positive associations appeared to be stronger in ever smokers who consumed 16+ cigarettes/day (HRone-stage = 1.67, 95% CI = 1.29-2.16, P = 0.0001), and in those who started smoking at age younger than 16 (2.16, 1.33-3.50, 0.0103), with dose-response relationships (P-values for trend = 0.0028 and 0.0103, respectively). Quitting (versus daily smoking) showed a small reduced risk (stopped for 5+ years: HRone-stage = 0.91, 95% CI = 0.60-1.39, P = 0.66; for former smokers: HRtwo-stage = 0.84, 0.61-1.14, 0.26). Conclusions This first IPD meta-analysis from six prospective cohorts in endemic regions has provided robust observational evidence that smoking increased NPC risk in men. NPC should be added to the 12–16 cancer sites known to be tobacco-related cancers. Strong tobacco control policies, preventing young individuals from smoking, would reduce NPC risk in endemic regions.

BackgroundCigarette smoking is associated with nasopharyngeal cancer (NPC) risk. Whether quitting reduces the risk is unclear. We investigated the associations of NPC with duration of and age at quitting in an endemic region.MethodsWe investigated the associations between NPC and quitting in a multicenter case-control study in Hong Kong with 676 newly diagnosed NPC cases and 1,285 hospital controls between 2014 and 2017, using a computer-assisted self-administered questionnaire. Multivariable unconditional logistic regression yielded adjusted odds ratios (AORs) of NPC by quitting status, duration and age of quitting, combinations of duration and age of quitting, and quitting to smoking duration ratio, compared with current smoking.ResultsQuitting (AOR: 0.72; 95% CI: 0.53–0.98) and never smoking (0.73, 0.56–0.95) were associated with lower NPC risk. NPC risk decreased with (i) longer quitting duration (p < 0.01), reaching significance after 11–20 (0.62, 0.39–0.99) and 21+ years (0.54, 0.31–0.92) of quitting; (ii) younger quitting age (p = 0.01), reaching significance for quitting at p < 0.01), reaching significance when the ratio reached 1 (0.60, 0.39–0.93). Quitting younger (age ConclusionsWe have shown longer duration and younger age of quitting were associated with lower NPC risk, with dose-response relations. Our findings support including smoking as a cause of NPC. Stronger tobacco control measures and quitting services are needed to prevent NPC.

Summary Background & aims Little is known about the risk of nasopharyngeal carcinoma (NPC) in relation to vitamin D exposure. The aim of this study was to examine the associations of NPC risk with serum level of 25-hydroxyvitamin D (25OHD) and genetic predicted 25OHD, and potential effect modification by several putative risk factors of NPC. Methods Our multicenter case–control study in Hong Kong recruited 815 NPC cases and 1502 frequency-matched (by sex and age) hospital controls from five major regional hospitals, and recruited 299 healthy subjects from blood donation centers (2014–2017). Circulating level of 25-hydroxyvitamin D (25OHD) and genetic predicted 25OHD (rs12785878, rs11234027, rs12794714, rs4588 and rs6013897) were measured by validated enzyme immunoassay and the iPLEX assay on the MassARRAY System, respectively. Data were also collected on demographics, lifestyle factors, ultraviolet radiation exposure, and potential confounders using a computer-assisted, self-administered questionnaire with satisfactory test-retest reliability. Unconditional logistic regression models were used to estimate ORs and 95% CIs. Results Despite no significant association of NPC risk with circulating 25OHD and genetic predicted 25OHD, there was evidence for an inverse association in participants with normal body mass index (between 18.5 and 27.5) across categories of 25OHD (Ptrend = 0.003), and a positive association in those with low socioeconomic status across categories based on the genetic score (Ptrend = 0.005). In addition, risk of NPC diagnosed at an early stage was higher for genetically lower 25OHD level (adjusted OR = 3.09, 95% CI = 1.04–9.21, Ptrend = 0.022). Conclusions Findings of this first comprehensive study to investigate the positive association of NPC risk with vitamin D deficiency need to be confirmed and be best interpreted with results of further similar studies. Our findings may inform possible etiological mechanisms of the associations with several putative risk/protective factors of NPC.

Systemic lupus erythematosus (SLE), a worldwide autoimmune disease with high heritability, shows differences in prevalence, severity and age of onset among different ancestral groups. Previous genetic studies have focused more on European populations, which appear to be the least affected. Consequently, the genetic variations that underlie the commonalities, differences and treatment options in SLE among ancestral groups have not been well elucidated. To address this, we undertake a genome-wide association study, increasing the sample size of Chinese populations to the level of existing European studies. Thirty-eight novel SLE-associated loci and incomplete sharing of genetic architecture are identified. In addition to the human leukocyte antigen (HLA) region, nine disease loci show clear ancestral differences and implicate antibody production as a potential mechanism for differences in disease manifestation. Polygenic risk scores perform significantly better when trained on ancestry-matched data sets. These analyses help to reveal the genetic basis for disparities in SLE among ancestral groups., The presentation of systemic lupus erythematosus has been known to differ by ancestry, but the underlying genetic factors remain unclear. Here, the authors report ancestry-specific susceptibility loci and better risk prediction when using data from matched ancestral groups.

Background We investigated the relationship of Epstein-Barr virus viral capsid antigen (EBV VCA-IgA) serostatus with ambient and personal ultraviolet radiation (UVR) and vitamin D exposure. Methods Using data from a multicenter case-control study, we included 1026 controls subjects in 2014–2017 in Hong Kong, China. Odds ratios (ORs) and 95% confidence intervals (CIs) of the association between UVR exposure and EBV VCA-IgA (seropositivity vs seronegativity) were calculated using unconditional logistic regression models adjusted for potential confounders. Results We observed a large increase in seropositivity of EBV VCA-IgA in association with duration of sunlight exposures at both 10 years before recruitment and age 19–30 years (adjusted OR = 3.59, 95% CI = 1.46–8.77; and adjusted OR = 2.44, 95% CI = 1.04–5.73 for ≥8 vs Conclusions Our results suggest that personal UVR exposure may be associated with higher risk of EBV reactivation, but we did not find clear evidence of vitamin D exposure (observational or genetic), a molecular mediator of UVR exposure. Further prospective studies in other populations are needed to confirm this finding and to explore the underlying biological mechanisms. Information on photosensitizing agents, and serological markers of EBV, and biomarkers related to systemic immunity and inflammation should be collected and are also highly relevant in future studies.

Systemic lupus erythematosus (SLE), a worldwide autoimmune disease with high heritability, shows differences in prevalence, severity and age of onset among different ancestral groups. Previous genetic studies have focused more on European populations, which appear to be the least affected. Consequently, the genetic variations that underly the commonalities, differences and treatment options in SLE among ancestral groups have not been well elucidated. To address this, we undertook a genome-wide association study, increasing the sample size of Chinese populations to the level of existing European studies. Thirty-eight novel SLE-associated loci and incomplete sharing of genetic architecture were identified. Nine disease loci showed clear ancestral group heterogeneity and implicated antibody production as a potential mechanism for differences in disease manifestation. Polygenic risk scores performed significantly better when trained on matched ancestral data sets. These analyses help to reveal the genetic bases for disparities in SLE among ancestral groups.

Nasopharyngeal carcinoma (NPC) is uncommon with a unique geographical distribution. The age-standardized incidence ranges from below 1 in nonendemic areas to 25+/100,000 person-years in endemic regions, and has decreased without specific primary prevention in the past four decades. We have found that smoking is likely a causal factor, family history of NPC a strong risk factor, while vitamin D and milk consumption, and better socioeconomic status, could be protective. The interaction between genetic factors, Epstein–Barr virus (EBV) infection, and environmental and lifestyle risk factors (classical and novel) warrants further investigation using more vigorous methods. Screening by EBV serological markers and circulating EBV DNA in asymptomatic Chinese men has identified NPC cases at earlier stages and with better survival than a historical cohort in Southern China. Further trials and assessment are needed. International or multicenter collaborations on individual data meta-analysis of case-control and cohort studies are warranted.

We evaluated the reliability of early life nasopharyngeal carcinoma (NPC) aetiology factors in the questionnaire of an NPC case-control study in Hong Kong during 2014–2017. 140 subjects aged 18+ completed the same computer-assisted questionnaire twice, separated by at least 2 weeks. The questionnaire included most known NPC aetiology factors and the present analysis focused on early life exposure. Test-retest reliability of all the 285 questionnaire items was assessed in all subjects and in 5 subgroups defined by cases/controls, sex, time between 1st and 2nd questionnaire (2–29/≥30 weeks), education (secondary or less/postsecondary), and age (25–44/45–59/60+ years) at the first questionnaire. The reliability of items on dietary habits, body figure, skin tone and sun exposure in early life periods (age 6–12 and 13–18) was moderate-to-almost perfect, and most other items had fair-to-substantial reliability in all life periods (age 6–12, 13–18 and 19–30, and 10 years ago). Differences in reliability by strata of the 5 subgroups were only observed in a few items. This study is the first to report the reliability of an NPC questionnaire, and make the questionnaire available online. Overall, our questionnaire had acceptable reliability, suggesting that previous NPC study results on the same risk factors would have similar reliability.

Background Nasopharyngeal carcinoma (NPC), also known as Cantonese cancer, is rare worldwide, but has particularly high incidence in North Africa and Southeast Asia, especially in Guangdong, China, such as Guangzhou. Tobacco causes head and neck cancers, but nasopharyngeal carcinoma is not included as causally related to smoking in the 2014 United States Surgeon General’s report. Prospective evidence remains limited. We used Guangzhou Occupational Cohort data to conduct the first and robust prospective study on smoking and NPC mortality in an NPC high-risk region. Methods Information on demographic characteristics and smoking status was collected through occupational health examinations in factories and driver examination stations from March 1988 to December 1992. Vital status and causes of deaths were retrieved until the end of 1999. Cox proportional hazard model was used to assess the association of smoking with NPC mortality. Results Of 101,823 subjects included for the present analysis, 34 NPC deaths occurred during the average 7.3 years of follow up. The mean age (standard deviation) of the subjects was 41 (5.7) years. Compared with never smokers, the hazard ratio (HR) of NPC mortality was 2.95 (95 % confidence interval 1.01–8.68; p = 0.048) for daily smokers and 4.03 (1.29–12.58; p = 0.016) for smokers with more than 10 pack-years of cumulative consumption, after adjusting for age, sex, education, drinking status, occupation and cohort status and accounting for smoking-drinking interaction. The risk of NPC mortality increased significantly with cigarettes per day (p for trend = 0.01) and number of pack-years (p for trend = 0.02). Conclusions In this first and largest cohort in a high NPC risk region, smoking was associated with higher NPC mortality. The findings have shown statistically significant dose–response trend between smoking amount and smoking cumulative consumption and the risk of NPC mortality, but due to the small event number, further studies with larger sample size are needed to confirm the findings in the present study. Our results support that smoking is one of the risk factors likely to be causally associated with NPC mortality. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1902-9) contains supplementary material, which is available to authorized users.

Hazard ratios (HRs) of NPC deaths by smoking status in the combined cohort (men). Figure S1: The flow chart of the analytical cohort selection in Guangzhou Occupational Cohort (GZOC). (DOCX 29 kb)

In the title mononuclear complex, [Mn(C14H10NO3)2(CH3OH)4], the MnII atom, lying on an inversion centre, exhibits a distorted octahedral geometry, defined by two O atoms from two monodentate ligands and four O atoms from four methanol molecules. The crystal structure involves intramolecular O—H...N and O—H...O and intermolecular O—H...O hydrogen bonds.

The asymmetric unit of the title complex, [Pd2(NO3)4(C58H52N2P4)], contains one half-molecule, in which the central benzene ring is located on a crystallographic centre of inversion. The Pd atom has a distorted square-planar coordination consisting of two P and two O atoms. In the crystal structure, intermolecular C—H...O interactions link the molecules into chains, and π–π contacts between the phenyl rings [centroid–centroid distance = 3.928 (3) Å] may further stabilize the structure.

The asymmetric unit of the title complex, [Pd(2)(NO(3))(4)(C(58)H(52)N(2)P(4))], contains one half-mol-ecule, in which the central benzene ring is located on a crystallographic centre of inversion. The Pd atom has a distorted square-planar coordination consisting of two P and two O atoms. In the crystal structure, inter-molecular C-H⋯O inter-actions link the mol-ecules into chains, and π-π contacts between the phenyl rings [centroid-centroid distance = 3.928 (3) Å] may further stabilize the structure.

One of the prime designs for the next generation IP routers is the IP-lookup mechanism. The IP lookup has become a major performance bottleneck for the routers. In this paper, we propose a complete hardware architecture which includes searching, updating, inserting, and deleting functions. A simple hash hardware design is used to reduce the lookup time, and a CAM is also used to solve the collision problems effectively. The ASIC includes search unit, memory controller, 1M-byte cache and 3.18 Kbytes CAM for a 32000 entries routing table. The searching, updating and deleting functions only need 1 cycle and it is 96.88% to chance to hit the correct next hop in the first cycle.

The asymmetric unit of the title complex, [Pd2(NO3)4(C58H52N2P4)], contains one half-mol­ecule, in which the central benzene ring is located on a crystallographic centre of inversion. The Pd atom has a distorted square-planar coordination consisting of two P and two O atoms. In the crystal structure, inter­molecular C—H⋯O inter­actions link the mol­ecules into chains, and π–π contacts between the phenyl rings [centroid–centroid distance = 3.928 (3) A] may further stabilize the structure.

The asymmetric unit of the title compound, [Zn(C(12)H(11)N(2)O(4))(2)(H(2)O)(4)]·4H(2)O, contains one-half of the complex mol-ecule and two uncoordin-ated water mol-ecules. The four water O atoms in the equatorial plane around the Zn(II) centre ( symmetry) form a distorted square-planar arrangement, while the distorted octa-hedral coordination geometry is completed by the O atoms of the zwitterionic 2-methyl-benzimidazolium-1,3-diacetate ligands in the axial positions. The benzimidazole ring system is planar, with a maximum deviation of 0.041 (3) Å. Intra-molecular O-H⋯O hydrogen bonding results in the formation of a non-planar six-membered ring. In the crystal structure, strong intra- and inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network. π-π contacts between benzimidazole rings [centroid-centroid distance = 3.899 (1) Å] may further stabilize the structure.