Microbes translocation from oral cavity to nasopharyngeal carcinoma in patients

The presence of oral microbes in extra-oral sites is linked to gastrointestinal cancers. However, their potential ectopically colonization in the nasopharynx and impact on local cancer development remains uncertain. Our study involving paired nasopharyngeal-oral microbial samples from nasopharyngeal carcinoma (NPC) patients and controls unveils an aberrant oral-to-nasopharyngeal microbial translocation associated with increased NPC risk (OR = 4.51, P = 0.012). Thirteen species are classified as oral-translocated and enriched in NPC patients. Among these, Fusobacterium nucleatum and Prevotella intermedia are validated through culturomics and clonal strain identification. Nasopharyngeal biopsy meta-transcriptomes confirm these microbes within tumors, influencing local microenvironment and cytokine response. These microbes correlate significantly with the Epstein-Barr virus (EBV) loads in the nasopharynx, exhibiting an increased dose-response relationship. Collectively, our study identifies oral microbes migrating to the nasopharynx, infiltrating tumors, impacting microenvironments and linking with EBV infection. These results enhance our understanding of abnormal microbial communication and their roles in carcinogenesis.

EBV DNA methylation profiles and its application in distinguishing nasopharyngeal carcinoma and nasal NK/T-cell lymphoma

BACKGROUND

As an oncovirus, EBV is associated with multiple cancers, including solid tumors and hematological malignancies. EBV methylation plays an important role in regulating tumor occurrence. However, the EBV methylation profiles in EBV-associated tumor tissues are poorly understood.

RESULTS

In this study, EBV methylation capture sequencing was conducted in several different tumor tissue samples, including NPC, EBVaGC, lung LELC and parotid LELC. Besides, EBV capture sequencing and following qMSP were performed on nasopharyngeal brushing samples from NPC and nasal NKTCL patients. Our results showed that the EBV genome among different types of tumors displayed specific methylation patterns. Among the four types of tumors from epithelial origin (NPC, EBVaGC, lung LELC and parotid LELC), the most significant differences were found between EBVaGC and the others. For example, in EBVaGC, all CpG sites within 1,44,189-1,45,136 bp of the EBV genome sequence on gene RPMS1 were hyper-methylated compared to the others. Differently, significant differences of EBV CpG sites, particularly those located on gene BILF2, were observed between NPC and nasal NKTCL patients in nasopharyngeal brushing samples. Further, the methylated level of BILF2 was further detected using qMSP, and a diagnostic model distinguishing NPC and nasal NKTCL was established. The AUC of the model was 0.9801 (95% CI 0.9524-1.0000), with the sensitivity and specificity of 98.81% (95% CI 93.63-99.94%) and 76.92% (95% CI 49.74-91.82%), respectively.

CONCLUSIONS

Our study reveals more clues for further understanding the pathogenesis of EBV, and provides a possibility for distinguishing EBV-related tumor by detecting specific EBV CpG sites.

A comprehensive predictive model for radiation-induced brain injury in risk stratification and personalized radiotherapy of nasopharyngeal carcinoma

BACKGROUND AND PURPOSE

Radiation-induced brain injury (RBI) is a severe radiotoxicity for nasopharyngeal carcinoma (NPC) patients, greatly affecting their long-term life quality and survival. We aim to establish a comprehensive predictive model including clinical factors and newly developed genetic variants to improve the precision of RBI risk stratification.

MATERIALS AND METHODS

By performing a large registry-based retrospective study with magnetic resonance imaging follow-up on RBI development, we conducted a genome-wide association study and developed a polygenic risk score (PRS) for RBI in 1189 NPC patients who underwent intensity-modulated radiotherapy. We proposed a tolerance dose scheme for temporal lobe radiation based on the risk predicted by PRS. Additionally, we established a nomogram by combining PRS and clinical factors for RBI risk prediction.

RESULTS

The 38-SNP PRS could effectively identify high-risk individuals of RBI (P = 1.42 × 10-34). Based on genetic risk calculation, the recommended tolerance doses of temporal lobes should be 57.6 Gy for individuals in the top 10 % PRS subgroup and 68.1 Gy for individuals in the bottom 50 % PRS. Notably, individuals with high genetic risk (PRS > P50) and receiving high radiation dose in the temporal lobes (D0.5CC > 65 Gy) had an approximate 50-fold risk over individuals with low PRS and receiving low radiation dose (HR = 50.09, 95 %CI = 24.27-103.35), showing an additive joint effect (Pinteraction < 0.001). By combining PRS with clinical factors including age, tumor stage, and radiation dose of temporal lobes, the predictive accuracy was significantly improved with C-index increased from 0.78 to 0.85 (P = 1.63 × 10-2).

CONCLUSIONS

The PRS, together with clinical factors, could improve RBI risk stratification and implies personalized radiotherapy.

The interaction and mediation effects between the host genetic factors and Epstein-Barr virus VCA-IgA in the risk of nasopharyngeal carcinoma

Previous studies have demonstrated strong associations between host genetic factors and Epstein-Barr virus (EBV) VCA-IgA with the risk of nasopharyngeal carcinoma (NPC). However, the specific interplay between host genetics and EBV VCA-IgA on NPC risk is not well understood. In this two-stage case-control study (N = 4804), we utilized interaction and mediation analysis to investigate the interplay between host genetics (genome-wide association study-derived polygenic risk score [PRS]) and EBV VCA-IgA antibody level in the NPC risk. We employed a four-way decomposition analysis to assess the extent to which the genetic effect on NPC risk is mediated by or interacts with EBV VCA-IgA. We consistently found a significant interaction between the PRS and EBV VCA-IgA on NPC risk (discovery population: synergy index [SI] = 2.39, 95% confidence interval [CI] = 1.85-3.10; replication population: SI = 3.10, 95% CI = 2.17-4.44; all pinteraction  < 0.001). Moreover, the genetic variants included in the PRS demonstrated similar interactions with EBV VCA-IgA antibody. We also observed an obvious dose-response relationship between the PRS and EBV VCA-IgA antibody on NPC risk (all ptrend  < 0.001). Furthermore, our decomposition analysis revealed that a substantial proportion (approximately 90%) of the genetic effects on NPC risk could be attributed to host genetic-EBV interaction, while the risk effects mediated by EBV VCA-IgA antibody were weak and statistically insignificant. Our study provides compelling evidence for an interaction between host genetics and EBV VCA-IgA antibody in the development of NPC. These findings emphasize the importance of implementing measures to control EBV infection as a crucial strategy for effectively preventing NPC, particularly in individuals at high genetic risk.

Saliva biopsy: Detecting the difference of EBV DNA methylation in the diagnosis of nasopharyngeal carcinoma

Saliva sampling is a non-invasive method, and could be performed by donors themselves. However, there are few studies reporting biomarkers in saliva in the diagnosis of NPC. A total of 987 salivary samples were used in this study. First, EBV DNA methylation was profiled by capture sequencing in the discovery cohort (n = 36). Second, a q-PCR based method was developed and five representative EBV DNA CpG sites (11 029 bp, 45 849 bp, 57 945 bp, 66 226 bp and 128 102 bp) were selected and quantified to obtain the methylated density in the validation cohort1 (n = 801). Third, a validation cohort2 (n = 108) was used to further verify the differences of EBV methylation in saliva. A significant increase of EBV methylation was found in NPC patients compared with controls. The methylated score of EBV genome obtained by capture sequencing could distinguish NPC from controls (sensitivity 90%, specificity 100%). Further, the methylated density of EBV DNA CpG sites revealed by q-PCR showed a good diagnostic performance. The sensitivity and specificity of detecting a single CpG site (11 029 bp) could reach 75.4% and 99.7% in the validation cohort1, and 78.2% and 100% in the validation cohort2. Besides, the methylated density of the CpG site was found to decrease below the COV in NPC patients after therapy, and increase above the COV after recurrence. Our study provides an appealing alternative for the non-invasive detection of NPC without clinical setting. It paves the way for conducting a home-based large-scale screening in the future.

High-throughput identification of regulatory elements and functional assays to uncover susceptibility genes for nasopharyngeal carcinoma

Large-scale genetic association studies have identified multiple susceptibility loci for nasopharyngeal carcinoma (NPC), but the underlying biological mechanisms remain to be explored. To gain insights into the genetic etiology of NPC, we conducted a follow-up study encompassing 6,907 cases and 10,472 controls and identified two additional NPC susceptibility loci, 9q22.33 (rs1867277; OR = 0.74, 95% CI = 0.68-0.81, p = 3.08 × 10^-11) and 17q12 (rs226241; OR = 1.42, 95% CI = 1.26-1.60, p = 1.62 × 10^-8). The two additional loci, together with two previously reported genome-wide significant loci, 5p15.33 and 9p21.3, were investigated by high-throughput sequencing for chromatin accessibility, histone modification, and promoter capture Hi-C (PCHi-C) profiling. Using luciferase reporter assays and CRISPR interference (CRISPRi) to validate the functional profiling, we identified PHF2 at locus 9q22.33 as a susceptibility gene. PHF2 encodes a histone demethylase and acts as a tumor suppressor. The risk alleles of the functional SNPs reduced the expression of the target gene PHF2 by inhibiting the enhancer activity of its long-range (4.3 Mb) cis-regulatory element, which promoted proliferation of NPC cells. In addition, we identified CDKN2B-AS1 as a susceptibility gene at locus 9p21.3, and the NPC risk allele of the functional SNP rs2069418 promoted the expression of CDKN2B-AS1 by increasing its enhancer activity. The overexpression of CDKN2B-AS1 facilitated proliferation of NPC cells. In summary, we identified functional SNPs and NPC susceptibility genes, which provides additional explanations for the genetic association signals and helps to uncover the underlying genetic etiology of NPC development.

Peptidome-wide association analysis of Epstein-Barr virus identifies epitope repertoires associated with nasopharyngeal carcinoma

Human leukocyte antigen (HLA) molecules are essential for presenting Epstein-Barr virus (EBV) antigens and are closely related to nasopharyngeal carcinoma (NPC). This study aims to systematically investigate the association between HLA-bound EBV peptides and NPC risk through in silico HLA-peptide binding prediction. A total of 455 NPC patients and 463 healthy individuals in NPC endemic areas were recruited, and HLA-target sequencing was performed. HLA-peptide binding prediction for EBV, followed by peptidome-wide logistic regression and motif analysis, was applied. Binding affinity changes for EBV peptides carrying high-risk mutations were analyzed. We found that NPC-associated EBV peptides were significantly enriched in immunogenic proteins and core linkage disequilibrium (LD) proteins related to evolution, especially those binding HLA-A alleles (p = 3.10 × 10^-4 for immunogenic proteins and p = 8.10 × 10^-5 for core LD proteins related to evolution). These peptides were clustered and showed binding motifs of HLA supertypes, among which supertype A02 presented an NPC-risk effect (p_adj  = 3.77 × 10^-4 ) and supertype A03 presented an NPC-protective effect (p_adj  = 4.89 × 10^-4 ). Moreover, a decreased binding affinity toward risk HLA supertype A02 was observed for the peptide carrying the NPC-risk mutation BNRF1 V1222I (p = 0.0078), and an increased binding affinity toward protective HLA supertype A03 was observed for the peptide carrying the NPC-risk mutation BALF2 I613V (p = 0.022). This study revealed the distinct preference of EBV peptides for binding HLA supertypes, which may contribute to shaping EBV population structure and be involved in NPC development.

Association of HLA diversity with the risk of 25 cancers in the UK Biobank

BACKGROUND

The human leukocyte antigen (HLA) is a highly polymorphic region, and HLA diversity may play a role in presenting tumour-associated peptides and inducing immune responses. However, the effect of HLA diversity on cancers has not been fully assessed. We aimed to explore the role of HLA diversity on cancer development.

METHODS

A pan-cancer analysis was performed to evaluate the effect of HLA diversity, measured by HLA heterozygosity and HLA evolutionary divergence (HED), on the susceptibility of 25 cancers in the UK Biobank.

FINDINGS

We observed that the diversity of HLA class II locus was associated with a lower risk of lung cancer (OR_hetero = 0.94, 95% CI = 0.90-0.97, P = 1.29 × 10^-4) and head and neck cancer (OR_hetero = 0.91, 95% CI = 0.86-0.96, P = 1.56 × 10^-3). Besides, a lower risk of non-Hodgkin lymphoma was associated with an increased diversity of HLA class I (OR_hetero = 0.92, 95% CI = 0.87-0.98, P = 8.38 × 10^-3) and class II locus (OR_hetero = 0.89, 95% CI = 0.86-0.92, P = 1.65 × 10^-10). A lower risk of Hodgkin lymphoma was associated with the HLA class I diversity (OR_hetero = 0.85, 95% CI = 0.75-0.96, P = 0.011). The protective effect of HLA diversity was mainly observed in pathological subtypes with higher tumour mutation burden, such as lung squamous cell carcinoma (P = 9.39 × 10^-3) and diffuse large B cell lymphoma (P_{class I} = 4.12 × 10^-4; P_{class Ⅱ} = 4.71 × 10^-5), as well as the smoking subgroups of lung cancer (P = 7.45 × 10^-5) and head and neck cancer (P = 4.55 × 10^-3).

INTERPRETATION

We provided a systematic insight into the effect of HLA diversity on cancers, which might help to understand the etiological role of HLA on cancer development.

FUNDING

This study was supported by grants from the National Natural Science Foundation of China (82273705, 82003520); the Basic and Applied Basic Research Foundation of Guangdong Province, China (2021B1515420007); the Science and Technology Planning Project of Guangzhou, China (201804020094); Sino-Sweden Joint Research Programme (81861138006); the National Natural Science Foundation of China (81973131, 81903395, 81803319, 81802708).

Clinicopathologic features, tumor immune microenvironment and genomic landscape of EBV-related and EBV-unrelated poorly differentiated nonkeratinizing squamous cell carcinoma of the thymus

OBJECTIVES

Knowledge regarding thymic EBV-related poorly differentiated nonkeratinizing squamous cell carcinoma (PDNKSCC), also known as lymphoepithelial carcinoma (LEC), is extremely limited due to its rarity.

MATERIALS AND METHODS

This multi-institutional study enrolled 85 patients with thymic PDNKSCC. DNA in situ hybridization was performed to evaluate the EBV status of all 85 cases. Immunohistochemistry and next generation sequencing were performed to compare the differences in the clinicopathological and molecular features between EBV-related and EBV-unrelated PDNKSCC. Tumor-infiltrating lymphocytes (TILs) were also analyzed by these methods.

RESULTS

The 85 cases were classified into 27 EBV-related PDNKSCCs (31.8 %) and 58 EBV-unrelated PDNKSCCs (68.2 %) according to the EBV status, and 35 Lymphoepithelioma pattern (LP) (41.2 %) and 50 desmoplastic pattern (DP) (58.8 %) according to the histological characteristics. Compared to the EBV-unrelated PDNKSCC, EBV-related PDNKSCC showed a younger patient predominance and more commonly displayed a LP subtype. Additionally, LP-type cases were divided into two groups: Group 1 (EBV-related, 20/85) and Group 2 (EBV-unrelated, 15/85); the DP-type cases were divided into Group 3 (EBV-unrelated, 43/85) and Group 4 (EBV-related, 7/85). The four Groups showed a significant association with patients' OS and PFS. EBV-related PDNKSCC had significantly higher PD-L1 + tumor cells (TCs) and PD-L1 + and CD8 + immune cells (ICs) than EBV-unrelated PDNKSCC. The tumor microenvironment immune type (TMIT) I (PDL1-Tumor+/CD8-High) was more common in EBV-related PDNKSCC, especially in Group 1(LP and EBV related) with more than 90 % cases belonged to TMIT I. Molecular analysis demonstrated that EBV-related PDNKSCC had a significantly higher tumour mutational burden and frequency of somatic mutations than EBV-unrelated cases.

CONCLUSIONS

EBV-related PDNKSCC, especially the Group 1, could be a candidate for immunotherapy and EBV positivity may provide an indication for the selection of targeted therapy due to their high tumour mutational burden.

Clinical and genome-wide association analysis of chemoradiation-induced hearing loss in nasopharyngeal carcinoma

Chemoradiation-induced hearing loss (CRIHL) is one of the most devasting side effects for nasopharyngeal carcinoma (NPC) patients, which seriously affects survivors' long-term quality of life. However, few studies have comprehensively characterized the risk factors for CRIHL. In this study, we found that age at diagnosis, tumor stage, and concurrent cisplatin dose were positively associated with chemoradiation-induced hearing loss. We performed a genome-wide association study (GWAS) in 777 NPC patients and identified rs1050851 (within the exon 2 of NFKBIA), a variant with a high deleteriousness score, to be significantly associated with hearing loss risk (HR = 5.46, 95% CI 2.93-10.18, P = 9.51 × 10^-08). The risk genotype of rs1050851 was associated with higher NFKBIA expression, which was correlated with lower cellular tolerance to cisplatin. According to permutation-based enrichment analysis, the variants mapping to 149 hereditary deafness genes were significantly enriched among GWAS top signals, which indicated the genetic similarity between hereditary deafness and CRIHL. Pathway analysis suggested that synaptic signaling was involved in the development of CRIHL. Additionally, the risk score integrating genetic and clinical factors can predict the risk of hearing loss with a relatively good performance in the test set. Collectively, this study shed new light on the etiology of chemoradiation-induced hearing loss, which facilitates high-risk individuals' identification for personalized prevention and treatment.

The Oral Microbiome as Mediator between Oral Hygiene and Its Impact on Nasopharyngeal Carcinoma

Oral hygiene and the alteration of the oral microbiome have been linked to nasopharyngeal carcinoma (NPC). This study aimed to investigate whether the oral microbiome plays a mediating role in the relationship between oral hygiene and NPC, and identify differential microbial taxonomies that potentially mediated this association. We conducted a case–control study that involved 218 NPC patients and 192 healthy controls. The 16S rRNA gene sequencing of the V4 region was performed to evaluate the composition of the oral microbiome. Mediation analysis was applied to explore the relationship among oral hygiene, the oral microbiome and NPC. We found that dental fillings and poor oral hygiene score were associated with increased risks of NPC (OR = 2.51 (1.52–4.25) and OR = 1.54 (1.02–2.33)). Mediation analysis indicated that dental fillings increased the risk of NPC by altering the abundance of Erysipelotrichales, Erysipelotrichaceae, Solobacterium and Leptotrichia wadei. In addition, Leptotrichia wadei also mediated the association between oral hygiene score and the risk of NPC. Our study confirmed that poor oral hygiene increased the risk of NPC, which was partly mediated by the oral microbiome. These findings might help us to understand the potential mechanism of oral hygiene influencing the risk of NPC via the microbiome.

Quantitative detection of Epstein-Barr virus DNA methylation in the diagnosis of nasopharyngeal carcinoma by blind brush sampling

Detecting EBV DNA load in nasopharyngeal (NP) brushing samples for the diagnosis of nasopharyngeal carcinoma (NPC) has attracted widespread attentions. Currently, NP brush sampling mostly relies on endoscopic guidance, and there are few reports on diagnostic markers suitable for nonguided conditions (blind brush sampling), which is of great significance for extending its application. One hundred seventy nasopharyngeal brushing samples were taken from 98 NPC patients and 72 non-NPC controls under the guidance of endoscope, and 305 blind brushing samples were taken without endoscopic guidance from 164 NPC patients and 141 non-NPC controls (divided into discovery and validation sets). Among these, 38 cases of NPC underwent both endoscopy-guided NP brushing and blind brushing. EBV DNA load targeting BamHI-W region and EBV DNA methylation targeting 11029 bp CpG site located at Cp-promoter region were detected by quantitative polymerase chain reaction (q-PCR). EBV DNA load showed good classification accuracy for NPC in endoscopy-guided brushing samples (AUC = 0.984). However, in blind bushing samples, the diagnostic performance was greatly reduced (AUC = 0.865). Unlike EBV DNA load, the accuracy of EBV DNA methylation was less affected by brush sampling methods, whether in endoscopy-guided brushing (AUC = 0.923) or blind brushing (AUC = 0.928 in discovery set and AUC = 0.902 in validation set). Importantly, EBV DNA methylation achieved a better diagnostic accuracy than EBV DNA load in blind brushing samples. Overall, detection of EBV DNA methylation with blind brush sampling shows great potential in the diagnosis of NPC and may facilitate its use in nonclinical screening of NPC.

Oral Microbiota Alteration and Roles in Epstein-Barr Virus Reactivation in Nasopharyngeal Carcinoma

Microbiota has recently emerged as a critical factor associated with multiple malignancies. Nasopharyngeal carcinoma (NPC) is highly associated with Epstein-Barr virus (EBV); the oncovirus resides and is transmitted in the oral cavity. However, the alternation of oral microbiota in NPC patients and its potential link to EBV reactivation and host cell response under the simultaneous existence of EBV and specific bacteria is largely unknown. Here, oral microbiota profiles of 303 NPC patients and controls with detailed clinical information, including serum EBV anti-virus capsid antigen (VCA) IgA level, were conducted. A distinct microbial community with lower diversity and imbalanced composition in NPC patients was observed. Notably, among enriched bacteria in patients, Streptococcus sanguinis was associated with anti-VCA IgA, an indicator of NPC risk and EBV reactivation. By measuring the concentration of its metabolite, hydrogen peroxide (H2O2), in the saliva of clinical patients, we found the detection rate of H2O2 was 2-fold increased compared to healthy controls. Further coculture assay of EBV-positive Akata cells with bacteria in vitro showed that S. sanguinis induced EBV lytic activation by its metabolite, H2O2. Host and EBV whole genome-wide transcriptome sequencing and EBV methylation assays showed that H2O2 triggered the host cell signaling pathways, notably tumor necrosis factor alpha (TNF-α) via NF-κB, and induced the demethylation of the global EBV genome and the expression of EBV lytic-associated genes, which could result in an increase of virus particle release and potential favorable events toward tumorigenesis. In brief, our study identified a characterized oral microbial profile in NPC patients and established a robust link between specific oral microbial alteration and switch of latency to lytic EBV infection status in the oral cavity, which provides novel insights into EBV's productive cycle and might help to further clarify the etiology of NPC. IMPORTANCE EBV is classified as the group I human carcinogen and is associated with multiple cancers, including NPC. The interplays between the microbiota and oncovirus in cancer development remain largely unknown. In this study, we investigate the interactions between resident microbes and EBV coexistence in the oral cavity of NPC patients. We identify a distinct oral microbial feature for NPC patients. Among NPC-enriched bacteria, we illustrated that a specific species, S. sanguinis, associated with elevated anti-IgA VCA in patients, induced EBV lytic activation by its by-product, H2O2, and activated the TNF-α/NF-κB pathway of EBV-positive B cells in vitro, together with increased detection rate of H2O2 in patients' oral cavities, which strengthened the evidence of bacteria-virus-host interaction in physiological circumstances. The effects of imbalanced microbiota on the EBV latent-to-lytic switch in the oral cavity might create the likelihood of EBV infection in epithelial cells at the nasopharynx and help malignant transition and cancer development.

Whole-Exome Sequencing Study of Familial Nasopharyngeal Carcinoma and Its Implication for Identifying High-Risk Individuals

BACKGROUND

Nasopharyngeal carcinoma (NPC) is closely associated with genetic factors and Epstein-Barr virus infection, showing strong familial aggregation. Individuals with a family history suffer elevated NPC risk, requiring effective genetic counseling for risk stratification and individualized prevention.

METHODS

We performed whole-exome sequencing on 502 familial NPC patients and 404 unaffected relatives and controls. We systematically evaluated the established cancer predisposition genes and investigated novel NPC susceptibility genes, making comparisons with 21 other familial cancers in the UK biobank (N = 5218).

RESULTS

Rare pathogenic mutations in the established cancer predisposition genes were observed in familial NPC patients, including ERCC2 (1.39%), TP63 (1.00%), MUTYH (0.80%), and BRCA1 (0.80%). Additionally, 6 novel susceptibility genes were identified. RAD54L, involved in the DNA repair pathway together with ERCC2, MUTYH, and BRCA1, showed the highest frequency (4.18%) in familial NPC. Enrichment analysis found mutations in TP63 were enriched in familial NPC, and RAD54L and EML2 were enriched in both NPC and other Epstein-Barr virus-associated cancers. Besides rare variants, common variants reported in the studies of sporadic NPC were also associated with familial NPC risk. Individuals in the top quantile of common variant-derived genetic risk score while carrying rare variants exhibited increased NPC risk (odds ratio = 13.47, 95% confidence interval = 6.33 to 28.68, P = 1.48 × 10-11); men in this risk group showed a cumulative lifetime risk of 24.19%, much higher than those in the bottom common variant-derived genetic risk score quantile and without rare variants (2.04%).

CONCLUSIONS

This study expands the catalog of NPC susceptibility genes and provides the potential for risk stratification of individuals with an NPC family history.

Development and validation of a polygenic hazard score to predict prognosis and adjuvant chemotherapy benefit in early-stage non-small cell lung cancer

Background

It remains controversial who would benefit from adjuvant chemotherapy (ACT) in patients with early-stage non-small cell lung cancer (NSCLC). We aim to construct a polygenic hazard score (PHS) to predict prognosis and ACT benefit among NSCLC patients.

Methods

We conducted a retrospective study including 1,395 stage I–II NSCLC patients. We performed a genome-wide association study (GWAS) on overall survival (OS) in patients treated with ACT (SYSUCC ACT set, n=404), and then developed a PHS using LASSO Cox regression in a random subset (training, n=202) and tested it in the remaining set (test, n=202). The PHS was further validated in two independent datasets (SYSUCC surgery set, n=624; PLCO cohort, n=367).

Results

The GWAS-derived PHS consisting of 37 single-nucleotide polymorphisms (SNPs) was constructed to classify patients into high and low PHS groups. For patients treated with ACT, those with low PHS had better clinical outcomes than high PHS (test set: HR =0.21, P<0.001; PLCO ACT set: HR =0.33, P=0.260). Similar results were found in the extended validation cohorts including patients with or without ACT (SYSUCC: HR =0.48, P<0.001; PLCO: HR =0.60, P=0.033). Within subgroup analysis by treatment or clinical factors, we further observed consistent results for the prognostic value of the PHS. Notably, ACT significantly improved OS in stage II patients with low PHS (HR =0.26, P<0.001), while there was no ACT survival benefit among patients with high PHS (HR =0.97, P=0.860).

Conclusions

The PHS improved prognostic stratification and could help identify patients who were most likely to benefit from ACT in early-stage NSCLC.

A polygenic risk score for nasopharyngeal carcinoma shows potential for risk stratification and personalized screening

Polygenic risk scores (PRS) have the potential to identify individuals at risk of diseases, optimizing treatment, and predicting survival outcomes. Here, we construct and validate a genome-wide association study (GWAS) derived PRS for nasopharyngeal carcinoma (NPC), using a multi-center study of six populations (6 059 NPC cases and 7 582 controls), and evaluate its utility in a nested case-control study. We show that the PRS enables effective identification of NPC high-risk individuals (AUC = 0.65) and improves the risk prediction with the PRS incremental deciles in each population (Ptrend ranging from 2.79 × 10-7 to 4.79 × 10-44). By incorporating the PRS into EBV-serology-based NPC screening, the test's positive predictive value (PPV) is increased from an average of 4.84% to 8.38% and 11.91% in the top 10% and 5% PRS, respectively. In summary, the GWAS-derived PRS, together with the EBV test, significantly improves NPC risk stratification and informs personalized screening.

Genomic landscape of Epstein–Barr virus in familial nasopharyngeal carcinoma

To better understand the genomic characteristics of Epstein–Barr virus (EBV) in familial nasopharyngeal carcinoma (NPC), we sequenced the EBV genomes by whole-genome capture in 38 unrelated patients with NPC family history in first-degree relatives and 47 healthy controls, including 13 with family history and 34 without. Compared with type 1 reference genome, mutation hotspots were observed in the latent gene regions of EBV in familial NPC cases. Population structure analysis showed that one cluster has a higher frequency in familial cases than in controls (OR=5.33, 95 % CI 2.50–11.33, P=1.42×10−5), and similar population structure composition was observed among familial and sporadic NPC cases in high-endemic areas. By genome-wide association analysis, four variants were found to be significantly associated with familial NPC. Consistent results were observed in the meta-analysis integrating two published case-control EBV sequencing studies in NPC high-endemic areas. High-risk haplotypes of EBV composed of 34 variants were associated with familial NPC risk (OR=13.85, 95 % CI 4.13–46.44, P=2.06×10−5), and higher frequency was observed in healthy blood-relative controls with NPC family history (9/13, 69.23 %) than those without family history (16/34, 47.06%). This study suggested the potential contribution of EBV high-risk subtypes to familial aggregation of NPC.

Prognostic Value of Oral Epstein–Barr Virus DNA Load in Locoregionally Advanced Nasopharyngeal Carcinoma

Background: Plasma Epstein–Barr virus (EBV) DNA load has been widely used for nasopharyngeal carcinoma (NPC) prognostic risk stratification. However, oral EBV DNA load, a non-invasive biomarker that reflects the EBV lytic replication activity, has not been evaluated for its prognostic value in NPC yet.

Methods: A total number of 1,194 locoregionally advanced NPC (LA-NPC) patients from south China were included from a prospective observational cohort (GARTC) with a median follow-up of 107.3 months. Pretreatment or mid-treatment mouthwashes were collected for EBV DNA detection by quantitative polymerase chain reaction (qPCR). The difference of pre- and mid-treatment oral EBV DNA load was tested by the Wilcoxon signed-rank test. The associations of oral EBV DNA load with overall survival (OS), progression-free survival (PFS), distant metastasis–free survival (DMFS), and locoregional relapse-free survival (LRFS) were assessed using the log-rank test and multivariate Cox regression.

Results: The high level of the oral EBV DNA load (>2,100 copies/mL) was independently associated with worse OS (HR = 1.45, 95% CI: 1.20–1.74, p < 0.001), PFS (HR = 1.38, 95% CI: 1.16–1.65, p < 0.001), DMFS (HR = 1.66, 95% CI: 1.25–2.21, p = 0.001), and LRFS (HR = 1.43, 95% CI: 1.05–1.96, p = 0.023). Similar and robust associations between oral EBV DNA load and prognosis were observed for patients in both the pretreatment and mid-treatment stages. The detection rate (71.7 vs. 48.6%, p < 0.001) and the median load of oral EBV DNA (13,368 vs. 382 copies/mL, p < 0.001) for patients in the pretreatment stage were significantly higher than those in the mid-treatment stage. The combination of the oral EBV DNA load and TNM staging provided a more precise risk stratification for the LA-NPC patients.

Conclusion: Oral EBV DNA load was an alternative non-invasive predictor of prognosis and may facilitate risk stratification for the LA-NPC patients.

Glycogenes in Oncofetal Chondroitin Sulfate Biosynthesis are Differently Expressed and Correlated With Immune Response in Placenta and Colorectal Cancer

Oncofetal chondroitin sulfate expression plays an important role in the development of tumors and the pathogenesis of malaria in pregnancy. However, the biosynthesis and functions of these chondroitin sulfates, particularly the tissue-specific regulation either in tumors or placenta, have not been fully elucidated. Here, by examining the glycogenes availability in chondroitin sulfate biosynthesis such as xylosytransferase, chondroitin synthase, sulfotransferase, and epimerase, the conserved or differential CS glycosylation in normal, colorectal cancer (CRC), and placenta tissue were predicted. We found that the expression of seven chondroitin sulfate biosynthetic enzymes, namely B4GALT7, B3GALT6, B3GAT3, CHSY3, CHSY1, CHPF, and CHPF2, were significantly increased, while four other enzymes (XYLT1, CHST7, CHST15, and UST) were decreased in the colon adenocarcinoma (COAD) and rectum adenocarcinoma (READ) patients. In the human placenta, where the distinct chondroitin sulfate is specifically bound with VAR2CSA on Plasmodium parasite-infected RBC, eight chondroitin sulfate biosynthesis enzymes (CSGALNACT1, CSGALNACT2, CHSY3, CHSY1, CHPF, DSE, CHST11, and CHST3) were significantly higher than the normal colon tissue. The similarly up-regulated chondroitin synthases (CHSY1, CHSY3, and CHPF) in both cancer tissue and human placenta indicate an important role of the proteoglycan CS chains length for Plasmodium falciparum VAR2CSA protein binding. Interestingly, twelve highly expressed chondroitin sulfate enzymes were significantly correlated to worse outcomes (prognosis) in both COAD and READ. Furthermore, we showed that the levels of chondroitin sulfate enzymes are significantly correlated with the expression of immuno-regulators and immune infiltration levels in CRCs and placenta, and involved in multiple essential pathways, such as extracellular matrix organization, epithelial-mesenchymal transition, and cell adhesion. Our study provides novel insights into the oncofetal chondroitin sulfate biosynthesis regulation and identifies promising targets and biomarkers of immunotherapy for CRC and malaria in pregnancy.

A fecal-based test for the detection of advanced adenoma and colorectal cancer: a case-control and screening cohort study

BACKGROUND

Colorectal cancer (CRC) is the leading cause of cancer death worldwide. Screening is a confirmed way to reduce the incidence and mortality rates of CRC. This study aimed to identify a fecal-based, noninvasive, and accurate method for detection of colorectal cancer (CRC) and advanced adenoma (AA).

METHODS

Through detection in tissue (n = 96) and fecal samples (n = 88) and tested in an independent group of fecal samples (n = 294), the methylated DNA marker ITGA4 and bacterial markers Fusobacterium nucleatum (Fn) and Pepetostreptococcusanaerobius (Pa) were identified from the candidate biomarkers for CRC and AA detection. A prediction score (pd-score) was constructed using the selected markers and fecal immunochemical test (FIT) for distinguishing AA and CRC from healthy subjects by logistic regression method. The diagnostic performance of the pd-score was compared with FIT and validated in the external validation cohort (n = 117) and in a large CRC screening cohort.

RESULTS

The pd-score accurately identified AA and CRC from healthy subjects with an area under the curve (AUC) of 0.958, at a specificity of 91.37%; the pd-score showed sensitivities of 95.38% for CRC and 70.83% for AA, respectively. In the external validation cohort, the sensitivities of the pd-score for CRC and AA detection were 94.03% and 80.00%, respectively. When applied in screening, the pd-score identified 100% (11/11) of CRC and 70.83% (17/24) of AA in participants with both colonoscopy results and qualified fecal samples, showing an improvement by 41.19% compared to FIT.

CONCLUSIONS

The current study developed a noninvasive and well-validated approach for AA and CRC detection, which could be applied widely as a diagnostic and screening test.

A comprehensive analysis of genetic diversity of EBV reveals potential high-risk subtypes associated with nasopharyngeal carcinoma in China

Epstein-Barr virus (EBV), a widespread oncovirus, is associated with multiple cancers including nasopharyngeal carcinoma (NPC), gastric cancer and diverse lymphoid malignancies. Recent studies reveal that specific EBV strains or subtypes are associated with NPC development in endemic regions. However, these NPC specific subtypes were only identified in a portion of infected individuals due possibly to the limited samples size studied or the complicated population structures of the virus. To identify additional high-risk EBV subtypes, we conducted a comprehensive genetic analysis of 22 critical viral proteins by using the largest dataset of 628 EBV genomes and 792 sequences of single target genes/proteins from GenBank. The phylogenetic, principal component and genetic structure analyses of these viral proteins were performed through worldwide populations. In addition to the general Asia-Western/Africa geographic segregation, population structure analysis showed a 'Chinese-unique' cluster (96.57% isolates from China) was highly enriched in the NPC patients, compared to the healthy individuals (89.6% vs. 44.5%, P < 0.001). The newly identified EBV subtypes, which contains four Chinese-specific NPC-associated amino acid substitutions (BALF2 V317M, BNRF1 G696R, V1222I and RPMS1 D51E), showed a robust positive association with the risk of NPC in China (Odds Ratio = 4.80, 20.00, 18.24 and 32.00 for 1, 2, 3 and 4 substitutions, respectively, P _trend <0.001). Interestingly, the coincidence of positively selected sites with NPC-associated substitutions suggests that adaptive nonsynonymous mutation on critical proteins, such as BNRF1, may interact with host immune system and contribute to the carcinogenesis of NPC. Our findings provide a comprehensive overview of EBV genetic structure for worldwide populations and offer novel clues to EBV carcinogenesis from the aspect of evolution.

[Epidemiological and Etiologic characteristics of Meningococcal meningitis in Xinjiang Uygur Autonomous Region,1960-2019]

Objective: To understand the epidemiological and etiologic characteristics of meningococcal meningitis in Xinjiang Uygur Autonomous Region (Xinjiang). Methods: The epidemiological data about the meningococcal meningitis cases in Xinjiang from 1960 to 2019 were collected from the China information system for disease control and prevention and the Center for Disease Control and Prevention of Xinjiang. The epidemiological characteristics were analyzed. Clinical specimens from suspected cases were cultured and tested by real-time PCR method. A survey on the carriage rate of Neisseria meningitides (Nm) in the healthy population was performed. The serogroups of isolates were determined by serum-agglutination and PCR methods. Multi-locus sequence typing was used for subtyping the isolates. Results: The incidence rates of meningococcal meningitis in Xinjiang from 1960 to 2019 were 0.02/100 000-81.32/100 000, with the mortality as 1.05%-20.78%. The five districts with the most cases were Kashi prefecture, Aksu prefecture, Urumqi city, Changji Hui autonomous prefecture, and Hotan prefecture. Before 1990, serogroup A (81.82%) was the commonest group for cases and contacts. After 1990, 14.00% of the cases were caused by serogroups B, C, W, and Y. There was no predominant serogroup for contacts with serogroups B, C, W, Y, and C accounting for 23.28%, 18.53%, 15.52%, 9.91% and 7.33% respectively. The general Nm carriage rate was 15.50%, with the population of 16 - 20 years age group having the highest rate (25.53%). Serogroups B (52.11%), W (20.66%), C (12.21%), and Y (9.39%) occupied 52.11%, 20.66%, 12.21% and 9.39% respectively. The commonest clonal lineages of Nm isolates were ST-4821, ST-175, and ST-5 clonal complexes, while the ST-5 and ST-4821 clonal complexes were the major ones for invasive strains. Conclusions: There appeared regional differences in the incidence rates of Xinjiang meningococcal meningitis, and the carriage rate of Nm was high. The serogroups have been changing. It is necessary to strengthen the prevention and control of meningococcal meningitis to prevent any potential outbreak.

Performance of common genetic variants in risk prediction for colorectal cancer in Chinese: A two-stage and multicenter study

The efficacy of susceptible variants derived from genome-wide association studies (GWAs) optimizing discriminatory accuracy of colorectal cancer (CRC) in Chinese remains unclear. In the present validation study, we assessed 75 recently identified variants from GWAs. A risk predictive model combining 19 variants using the least absolute shrinkage and selection operator (LASSO) statistics offered certain clinical advantages. This model demonstrated an area under the receiver operating characteristic (AUC) of 0.61 during training analysis and yielded robust AUCs from 0.59 to 0.61 during validation analysis in three independent centers. The individuals carrying the highest quartile of risk score revealed over 2-fold risks of CRC (ranging from 2.12 to 2.90) compared with those who presented the lowest quartile of risk score. This genetic model offered the possibility of partitioning risk within the average risk population, which might serve as a first step toward developing individualized CRC prevention strategies in China.

Polymorphisms in TYMS for Prediction of Capecitabine-Induced Hand-Foot Syndrome in Chinese Patients with Colorectal Cancer

Purpose

Capecitabine is an extensively used oral prodrug of 5-fluorouracil in treatment of colon cancer and is known to cause hand-foot syndrome (HFS). As the target enzyme for capecitabine, thymidylate synthase (TYMS) plays a key role for 5-fluorouracil metabolism and has been associated with some side effects caused by capecitabine. The aim of our study is to identify the possible genetic predictors of capecitabine-induced HFS (CAP-HFS) in Chinese colorectal cancer patients.

Materials and Methods

Whole exons of TYMS were sequenced for 288 extreme phenotype HFS patients, including 144 severe or early-onset (first 2 cycles) moderate HFS extreme cases and 144 extreme controls with no reported HFS. The associations between polymorphisms and CAP-HFS were analyzed using logistic regression under an additive model.

Results

We identified a novel risk mutation (c.1A>G, chr18:657743), was associated with severe HFS in an extreme case who was affected during the first cycle of treatment. Moreover, we identified three new variants, rs3786362, rs699517, rs2790, and two previously reported variants, 5’VNTR 2R/3R and 3′-untranslated region 6-bp ins-del, which were significantly associated with CAP-HFS (p < 0.05). In silico analysis revealed that the effect of these polymorphisms in the TYMS region on the development of HFS might not be restricted solely to the regulation of TYMS expression, but also the TYMS catalytic activity through the indirect effect on ENOSF1 expression.

Conclusion

This study identified new polymorphisms in TYMS gene significantly associated with CAP-HFS, which may serve as useful genetic predictors for CAP-HFS and help to elucidate the underlying mechanism of HFS.

Genome-wide association study identifies genetic susceptibility loci and pathways of radiation-induced acute oral mucositis

Background

Radiation-induced oral mucositis (OM) is one of the most common acute complications for head and neck cancer. Severe OM is associated with radiation treatment breaks, which harms successful tumor management. Radiogenomics studies have indicated that genetic variants are associated with adverse effects of radiotherapy.

Methods

A large-scale genome-wide scan was performed in 1467 nasopharyngeal carcinoma patients, including 753 treated with 2D-CRT from Genetic Architecture of the Radiotherapy Toxicity and Prognosis (GARTP) cohort and 714 treated with IMRT (192 from the GARTP and 522 newly recruited). Subgroup analysis by radiotherapy technique was further performed in the top associations. We also performed physical and regulatory mapping of the risk loci and gene set enrichment analysis of the candidate target genes.

Results

We identified 50 associated genomic loci and 64 genes via positional mapping, expression quantitative trait locus (eQTL) mapping, chromatin interaction mapping and gene-based analysis, and 36 of these loci were replicated in subgroup analysis. Interestingly, one of the top loci located in TNKS, a gene relevant to radiation toxicity, was associated with increased OM risk with OR = 3.72 of the lead SNP rs117157809 (95% CI 2.10–6.57; P = 6.33 × 10⁻⁶). Gene set analyses showed that the 64 candidate target genes were enriched in the biological processes of regulating telomere capping and maintenance and telomerase activity (Top P = 7.73 × 10⁻⁷).

Conclusions

These results enhance the biological understanding of radiotherapy toxicity. The association signals enriched in telomere function regulation implicate the potential underlying mechanism and warrant further functional investigation and potential individual radiotherapy applications.

Locomotor transition: how squid jet from water to air

The amazing multi-modal locomotion of flying squid helps to achieve fast-speed migration and predator-escape behavior. Observation of flying squid has been rarely reported in recent years, since it is challenging to clearly record the flying squid's aquatic-aerial locomotion in a marine environment. The existing reports of squid-flying events are rare and merely record the in-air motion. Therefore, the water-air locomotor transition of flying squid is still unknown. This paper proposes the idea of using CFD to simulate the process of the flying squid (Sthenoteuthis oualaniensis (S. oualaniensis)) launching from water into air. The results for the first time reveal the flow field information of squid in launching phase and show the kinematic parameters of flying squid in quantification. Both a trailing jet and pinch-off vortex rings are formed to generate launching thrust, and the formation number L _ω /D _ω is 5.22, demonstrating that the jet strategy is to produce greater time-averaged thrust rather than higher propulsion efficiency. The results also indicate that the maximum flying speed negatively correlates with the launch angle, indicating that a lower launch angle could result in a larger flying speed for the flying squid to escape. These findings explore the multi-modal locomotion of flying squid from a new perspective, helping to explain the trade-off strategy of water-to-air transition, and further enhance the performance of aquatic-aerial vehicles.

Using Meglumine Diatrizoate to improve the accuracy of diagnosis of cracked teeth on Cone-beam CT images

AIM

To explore in a laboratory setting the feasibility of using Meglumine Diatrizoate (MD) to improve the accuracy of diagnosis of cracked teeth on cone-beam CT (CBCT) images.

METHODOLOGY

Twenty-four teeth were cracked artificially by soaking them cyclically in liquid nitrogen and hot water. The number and position of crack lines were evaluated with a dental operating microscope and used as the gold standard. The artificially cracked teeth were then examined using routine scanning (RS) and enhanced scanning (ES) modes, respectively. For the ES mode, MD was painted on the surface of the crack lines, and then, CBCT scanning with the same parameters was performed after 10 min. A radiological graduate student and an experienced radiologist evaluated the presence or absence of crack lines, respectively. The differences between the RS and ES modes were determined and assessed using McNemar's test. Inter-examiner agreement and intra-examiner agreement were assessed using kappa analysis.

RESULTS

Fifty-seven crack lines were found in the 24 cracked teeth. In the RS mode, the accuracy of detection of crack lines was 23% (radiological graduate student) and 32% (experienced radiologist), whereas in the ES mode, the accuracy was 61% (radiological graduate student) and 65% (experienced radiologist). The inter-examiner agreement was 0.693 in RS mode and 0.849 in ES mode. The intra-examiner agreement was 0.872 and 0.949 for the radiological graduate student in RS and ES mode respectively; and one for the experienced radiologist both in RS and ES mode.

CONCLUSIONS

Compared with routine scanning mode, more crack lines could be detected in enhanced scanning mode using Meglumine Diatrizoate as a contrast medium. MD could be a potential contrast medium to improve the accuracy of detection of crack lines on CBCT images.

Association Between Environmental Factors and Oral Epstein-Barr Virus DNA Loads: A Multicenter Cross-sectional Study in China

Background

Oral Epstein-Barr virus (EBV) status reflects host EBV activity and potentially links to EBV-associated diseases, however, factors influencing oral EBV loads or reactivation, such as environmental exposures or host factors, are not fully understood.

Methods

A 2-stage, multicenter, cross-sectional study of 6558 subjects from 21 administrative cities of southern China and 3 populations from representative geographical areas in China (referred to as the south, north, and northeastern populations) was performed. The relationships between demographical factors and environmental exposures to EBV loads were analyzed by logistic regression models.

Results

Current smoking, with a dose-response effect, was found to be strongly associated with higher oral EBV loads in the pooled data, with an odds ratio of 1.58 (95% confidence interval, 1.39-1.79), as well as in each of the separate populations. The odds ratio increased to 3.06 when current smokers in southern China were compared to never smokers in northern China. Additionally, higher oral EBV loads tended to be detected in older participants, male participants, and participants in southern China.

Conclusions

This study provided evidence linking the effect of host-environmental factors, particularly smoking, to oral EBV activity. It could strengthen our understanding of the possible causal roles of EBV-related diseases, which may help to prevent or mitigate EBV-associated diseases.

Identification of risk loci and a polygenic risk score for lung cancer: a large-scale prospective cohort study in Chinese populations

BACKGROUND

Genetic variation has an important role in the development of non-small-cell lung cancer (NSCLC). However, genetic factors for lung cancer have not been fully identified, especially in Chinese populations, which limits the use of existing polygenic risk scores (PRS) to identify subpopulations at high risk of lung cancer for prevention. We therefore aimed to identify novel loci associated with NSCLC risk, and generate a PRS and evaluate its utility and effectiveness in the prediction of lung cancer risk in Chinese populations.

METHODS

To systematically identify genetic variants for NSCLC risk, we newly genotyped 19 546 samples from Chinese NSCLC cases and controls from the Nanjing Medical University Global Screening Array Project and did a meta-analysis of genome-wide association studies (GWASs) of 27 120 individuals with NSCLC and 27 355 without NSCLC (13 327 cases and 13 328 controls of Chinese descent as well as 13 793 cases and 14 027 controls of European descent). We then built a PRS for Chinese populations from all reported single-nucleotide polymorphisms that have been reported to be associated with lung cancer risk at genome-wide significance level. We evaluated the utility and effectiveness of the generated PRS in predicting subpopulations at high-risk of lung cancer in an independent prospective cohort of 95 408 individuals from the China Kadoorie Biobank (CKB) with more than 10 years' follow-up.

FINDINGS

We identified 19 susceptibility loci to be significantly associated with NSCLC risk at p≤5·0 × 10^-8, including six novel loci. When applied to the CKB cohort, the PRS of the risk loci successfully predicted lung cancer incident cases in a dose-response manner in participants at a high genetic risk (top 10%) than those at a low genetic risk (bottom 10%; adjusted hazard ratio 1·96, 95% CI 1·53-2·51; p_trend=2·02 × 10^-9). Specially, we observed consistently separated curves of lung cancer events in individuals at low, intermediate, and high genetic risk, respectively, and PRS was an independent effective risk stratification indicator beyond age and smoking pack-years.

INTERPRETATION

We have shown for the first time that GWAS-derived PRS can be effectively used in discriminating subpopulations at high risk of lung cancer, who might benefit from a practically feasible PRS-based lung cancer screening programme for precision prevention in Chinese populations.

FUNDING

National Natural Science Foundation of China, the Priority Academic Program for the Development of Jiangsu Higher Education Institutions, National Key R&D Program of China, Science Foundation for Distinguished Young Scholars of Jiangsu, and China's Thousand Talents Program.

Genome-Wide Association Study of Susceptibility Loci for Radiation-Induced Brain Injury

BACKGROUND

Radiation-induced brain injury is a nonnegligible issue in the management of cancer patients treated by partial or whole brain irradiation. In particular, temporal lobe injury (TLI), a deleterious late complication in nasopharyngeal carcinoma, greatly affects the long-term life quality of these patients. Although genome-wide association studies (GWASs) have successfully identified single nucleotide polymorphisms (SNPs) associated with radiation toxicity, genetic variants contributing to the radiation-induced brain injury have not yet been assessed.

METHODS

We recruited and performed follow-up for a prospective observational cohort, Genetic Architecture of Radiotherapy Toxicity and Prognosis, using magnetic resonance imaging for TLI diagnosis. We conducted genome-wide association analysis in 1082 patients and validated the top associations in two independent cohorts of 1119 and 741 patients, respectively. All statistical tests were two-sided.

RESULTS

We identified a promoter variant rs17111237 (A > G, minor allele frequency [MAF] = 0.14) in CEP128 associated with TLI risk (hazard ratio = 1.45, 95% confidence interval = 1.26 to 1.66, Pcombined=3.18 × 10-7) which is in moderate linkage disequilibrium (LD) with rs162171 (MAF = 0.18, R2 = 0.69), the top signal in CEP128 (hazard ratio = 1.46, 95% confidence interval = 1.29-1.66, Pcombined= 6.17 × 10-9). Combining the clinical variables with the top SNP, we divided the patients into different subgroups with varying risk with 5-year TLI-free rates ranging from 33.7% to 95.5%. CEP128, a key component of mother centriole, tightly interacts with multiple radiation-resistant genes and plays an important role in maintaining the functional cilia, which otherwise will lead to a malfunction of the neural network. We found that A > G alteration at rs17111237 impaired the promoter activity of CEP128 and knockdown of CEP128 decreased the clonogenic cell survival of U87 cells under radiation. Noteworthy, 12.7% (27/212) of the GWAS-based associated genes (P < .001) were enriched in the neurogenesis pathway.

CONCLUSIONS

This three-stage study is the first GWAS of radiation-induced brain injury that implicates the genetic susceptibility gene CEP128 involved in TLI development and provides the novel insight into the underlying mechanisms of radiation-induced brain injury.

Fine-mapping of HLA class I and class II genes identified two independent novel variants associated with nasopharyngeal carcinoma susceptibility

BACKGROUND

Several genome-wide association studies (GWASs) have identified strong associations between genetic variants in the human leukocyte antigen (HLA) region and nasopharyngeal carcinoma (NPC). However, given the complex LD pattern in this region, the causal variants and the underlying mechanism of how genetic variants in HLA contribute to NPC development is yet to be understood.

METHODS

To systematically characterize the HLA variants and their relationship to NPC susceptibility, we fine-mapped the HLA genes based on the GWAS data of 1583 NPC cases and 972 healthy controls, using SNP2HLA with the Pan-Asian panel as references. Stepwise conditional regression was used to identify independent association loci.

RESULTS

Interestingly, the most significant association was the presence of Gln in HLA-A amino acid position 62 (OR = 0.57, P = 1.41 × 10^-16 ). The G allele of rs2894207 located between HLA-B and HLA-C showed protective effect of NPC development (OR = 0.52, P = 2.23 × 10^-13 ). Additionally, amino acid Phe-67 located in the peptide-binding pocket of HLA-DRB1 was identified as a novel functional variant with OR = 0.64 and P = 9.64 × 10^-11 . Another novel variant, Glu-45 in HLA-B pocket B, conferred a protective effect on NPC susceptibility (OR = 0.64, P = 5.23 × 10^-8 ). These four variants explained 2.07% of the phenotypic variance for NPC risk.

CONCLUSION

In summary, by fine-mapping the HLA region in south Chinese population, we reported additional loci missed in the GWAS studies and provided a better understanding of the relationship between HLA and NPC susceptibility.

[A cross-sectional study of seroepidemiology of viral hepatitis among Uighurs in Shufu of Xinjiang]

Objective: To explore the status of seroepidemiology on hepatitis A, B and C among students and residents aged equal or greater than 18 years in south Xinjiang, and to provide scientific evidence for prevention and control of viral hepatitis. Methods: Uyghur students in four towns and villages were selected by cluster random sampling from Feb to May, 2015, and Uyghur residents aged 18 to 69 years were selected by stratified cluster sampling from May to September, 2016. 4 507 middle and primary Uygur students and 4 833 Uyghur resides equal or greater than 18 years attended this survey. Self-designed questionnaire was used to collect the demographic information. And Elisa test was adopted to detect HAV-IgG, HBsAg, HBsAb and HCV-IgG. Chi-square test was used to calculate the difference on antibody positive rate of three types of hepatitis among the participants. Results: The overall HAV-IgG positive rate was 99.45% (9 289/9 340). The positive rates were 99.70% (4 006/4 018) in male and 99.27% (5 283/5 322) in female (χ(2)=7.95, P=0.005). The HAV-IgG positive rate among people aged 10 to 14 years was the highest (99.91%, 2 233/2 235), and the difference between the age specific HAV-IgG positive rates was statistical significant (χ(2)=38.21, P<0.001). The overall HBsAg positive rate was 4.11% (384 cases), with 4.55% (183 cases) for male and 3.78% (201 cases) for female. The HBsAg positive rate among participants 19 to 24 years old was the highest (9.46%, 21/222) and the differences between the age specific HBsAg was statistically significant (χ(2)=116.22, P<0.001). The HBsAb positive rate was 35.03% (3 272 cases), with 35.59% (1 430 cases) for male and 34.61% (1 842 cases) for female, and the HBsAb positive rate among participants aged 15 to 18 years was the highest, which was 69.12% (696/1 007). The differences between the age specific HBsAb rates appeared statistically significant (χ(2)=671.80, P<0.001). The overall HCV-IgG positive rate was 0.65%(61 cases). The HCV-IgG positive rate in female was 0.86% (46 cases) and 0.37% (15 cases) in male (χ(2)=8.51, P=0.004).The HCV-IgG positive rate among participants aged over 70 years was the highest (3.78%,9/238) , and the difference between the age specific HCV-IgG positive rates had statistic significance (χ(2)=70.30, P<0.001). The HAV-IgG positive rate in hepatitis A vaccinees (100%, 876/876) was higher than that among the non-vaccinees (99.40%, 8 413/8 464) (χ(2)=4.26, P=0.039). The HBsAb positive rate in hepatitis B vaccinees was 39.32% (1 816/4 619) which was higher than that among the non-vaccinees (30.84%, 1 456/4 721) (χ(2)=73.68, P<0.001). Conclusion: The positive rate of overall HAV-IgG was high, male and participants aged between 10 to 14 had higher probability to be infected. But the infection rates of hepatitis B and C were low, with the low vaccination rate and the poor protective effectiveness of hepatitis B.

[Prevalence of hypertension and risk factors in Uygur population in Kashgar area of Xinjiang Uygur Autonomous Region]

Objective: To investigate the prevalence of hypertension and risk factors in Uygur adults in Kashgar of Xinjiang. Methods: A total of 4 748 Uygur adults aged ≥18 years selected through cluster random sampling in Shufu county of Kashgar prefecture were surveyed by means of questionnaire survey, physical examination and laboratory test. The prevalence, awareness, treatment and control rate of hypertension of different groups were calculated and risk factors of hypertension was analyzed by using non-conditional logistic regression model. Results: The overall prevalence of hypertension was 15.73% (age-adjusted prevalence was 13.75%). The prevalence rates of hypertension in men and women were 16.36% (age-adjusted prevalence was 12.96%), 15.39% (age-adjusted prevalence was 14.34%), respectively. The rates of awareness, treatment and control of hypertension were 59.57%, 52.74%, 21.29%, respectively. The prevalence of hypertension increased with age. Compared with age group 18-34 years, the age groups 55-64, ≥65 years had higher risk of hypertension and the OR values were 10.53, 20.96 for men and 16.27, 33.20 for women. The overweight (OR=1.47 for men, OR=1.82 for women, P<0.05) and obesity (OR=1.88 for men, OR=2.66 for women, P<0.05) also increased the risk of hypertension. The groups with family history of hypertension (OR=3.85 for men, OR=2.34 for women, P<0.05) also had higher risk of hypertension. Hypertriglyceridemia was positively correlated with the prevalence of hypertension in men (OR=1.62, 95%CI: 1.09-2.41). Conclusions: The prevalence of hypertension in Uygur adults in Kashgar area of Xinjiang was at relatively low level. The related risk factors were age, overweight, obesity, family history and hypertriglyceridemia in men and the risk factors were similar in women except hypertriglyceridemia.

[Prevalence of diabetes mellitus and associated risk factors in Uygur population in Kashgar area of Xinjiang Uygur Autonomous Region]

Objective: To investigate the epidemiologic characteristics of diabetes mellitus (DM) in Uygur residents in Kashgar of Xinjiang. Methods: The survey was conducted among the Uygur residents aged ≥18 years selected through stratified cluster sampling in Kashgar by means of questionnaire survey, physical examination and basic laboratory test. The prevalence of different groups were calculated and risk factors of DM was analyzed by logistic vegression model. Results: A total of 4 608 adults were surveyed. The prevalence of DM was 11.31% (standardized prevalence: 10.59%) and the prevalence was 13.65% (standardized prevalence: 12.34%) in males and 10.04% (standardized prevalence: 9.83%) in females. The prevalence increased with age. The prevalence of DM was higher than the prevalence of impaired fasting glucose (IFG) in people aged >60 years, especially in females. The rates of awareness, treatment and control of DM were 28.02%, 21.31% and 5.57%, respectively. Multivariate logistic regression analysis indicated that people aged 45-55, 55-65 and >65 years had higher risk of DM and the odds ratio were 2.08 (95%CI: 1.24-3.48), 2.73 (95%CI: 1.63-4.56) and 3.90 (95%CI: 2.24-6.78) for men and 2.63 (95% CI: 1.71-4.02), 3.14 (95%CI: 2.00-4.94) and 5.56 (95%CI: 3.47-8.92) for woman, respectively. Family history of DM (OR=2.88 for men, 95% CI: 1.45-5.72; OR=2.52 for women, 95% CI: 1.49-4.26) and BMI≥28.0 kg/m(2) (OR=1.77 for men, 95% CI: 1.19-2.64, OR=1.80 for women, 95% CI: 1.30-2.50) were also risk factors for DM. Conclusion: The prevalence of DM was high in Uygur residents in Kashgar, but the rate of awareness, treatment and control of DM were low. It is necessary to improve the detection rate of DM and conduct targeted prevention and control of DM.

Development of a ten-signature classifier using a support vector machine integrated approach to subdivide the M1 stage into M1a and M1b stages of nasopharyngeal carcinoma with synchronous metastases to better predict patients' survival

The aim of this study was to develop a prognostic classifier and subdivided the M1 stage for nasopharyngeal carcinoma patients with synchronous metastases (mNPC). A retrospective cohort of 347 mNPC patients was recruited between January 2000 and December 2010. Thirty hematological markers and 11 clinical characteristics were collected, and the association of these factors with overall survival (OS) was evaluated. Advanced machine learning schemes of a support vector machine (SVM) were used to select a subset of highly informative factors and to construct a prognostic model (mNPC-SVM). The mNPC-SVM classifier identified ten informative variables, including three clinical indexes and seven hematological markers. The median survival time for low-risk patients (M1a) as identified by the mNPC-SVM classifier was 38.0 months, and survival time was dramatically reduced to 13.8 months for high-risk patients (M1b) (P < 0.001). Multivariate adjustment using prognostic factors revealed that the mNPC-SVM classifier remained a powerful predictor of OS (M1a vs. M1b, hazard ratio, 3.45; 95% CI, 2.59 to 4.60, P < 0.001). Moreover, combination treatment of systemic chemotherapy and loco-regional radiotherapy was associated with significantly better survival outcomes than chemotherapy alone (the 5-year OS, 47.0% vs. 10.0%, P < 0.001) in the M1a subgroup but not in the M1b subgroup (12.0% vs. 3.0%, P = 0.101). These findings were validated by a separate cohort. In conclusion, the newly developed mNPC-SVM classifier led to more precise risk definitions that offer a promising subdivision of the M1 stage and individualized selection for future therapeutic regimens in mNPC patients.

XPG rs2296147 T>C polymorphism predicted clinical outcome in colorectal cancer

Xeroderma pigmentosum group G (XPG), one of key components of nucleotide excision repair pathway (NER), is involved in excision repair of UV-induced DNA damage. Single nucleotide polymorphisms (SNPs) in the XPG gene have been reported to associate with the clinical outcome of various cancer patients. We aimed to assess the impact of four potentially functional SNPs (rs2094258 C>T, rs2296147 T>C, rs751402 G>A, and rs873601 G>A) in the XPG gene on prognosis in colorectal cancer (CRC) patients. A total of 1901 patients diagnosed with pathologically confirmed CRC were genotyped for four XPG polymorphisms. Cox proportional hazards model analysis controlled for several confounding factors was conducted to compute hazard ratios (HRs) and 95% confidence intervals (CIs). Of the four included SNPs, only rs2296147 was shown to significantly affect progression-free survival (PFS) in CRC. Patients carrying rs2296147 CT/TT genotype had a significantly shorter median 10 years PFS than those carrying CC genotype (88.5 months vs. 118.1 months), and an increased progression risk were observed with rs2296147 (HR = 1.324, 95% CI = 1.046-1.667). Moreover, none of the four SNPs were associated with overall survival. In conclusion, our study showed that XPG rs2296147 CT/TT variants conferred significant survival disadvantage in CRC patients in term of PFS. XPG rs2296147 polymorphism could be predictive of unfavorable prognosis of CRC patients.

Mid-infrared photodetectors operating over an extended wavelength range up to 90 K

We report a wavelength threshold extension, from the designed value of 3.1 to 8.9 μm, in a p-type heterostructure photodetector. This is associated with the use of a graded barrier and barrier offset, and arises from hole-hole interactions in the detector absorber. Experiments show that using long-pass filters to tune the energies of incident photons gives rise to changes in the intensity of the response. This demonstrates an alternative approach to achieving tuning of the photodetector response without the need to adjust the characteristic energy that is determined by the band structure.

Association of Interleukin-10 -3575T>A and -1082A>G polymorphisms with non-Hodgkin lymphoma susceptibility: a comprehensive review and meta-analysis

A number of studies have investigated the associations between IL-10 polymorphisms and non-Hodgkin lymphoma (NHL) susceptibility; however, the conclusions were still contradictory. To acquire a more precise estimation of the association, we performed the current meta-analysis. We systematically searched publications from EMBASE and MEDLINE, and calculated pooled odds ratios (ORs) and 95 % confidence intervals (CIs) using either fixed-effects or random-effects model. Genotype-based IL-10 mRNA expression analysis was performed using online public database of 270 individuals with three different ethnicities. A total of 10,703 cases and 11,823 controls from 10 studies were included for the -3575T>A polymorphism, 10,226 cases and 12,215 controls from 17 studies for the -1082A>G polymorphism. Pooled results indicated that IL-10 -3575T>A was associated with increased risk of diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL), especially for Caucasians and hospital-based population. There was no association between IL-10 -1082A>G and NHL risk. However, subgroup analysis showed that IL-10 -1082GG might confer increased susceptibility to FL. In summary, this meta-analysis indicated that -3575T>A polymorphism was associated with altered NHL susceptibility for Caucasians and hospital-based population, especially for DLBCL and FL subtypes. The -1082A>G polymorphism may contribute to increased FL risk. Further large-scale population studies among different ethnicities are needed to validate these results.

[Elderly chronic lymphocytic leukemia combined with invasive aspergillosis infection in one case]

OBJECTIVE

This study was aimed to investigate the morphological, immunophenotype, cytogenetic characteristics, clinical and therapy features in one elderly patient with chronic lymphocytic leukemia (CLL) combined with invasive aspergillose infection(IAI).

METHODS

The morphological features of bone marrow cells from patient were observed by light microscope, the immunophenotype were detected by flow cytometry, the cytogenetic characteristics were assayed by conventional chromosomal analysis and fluorescence in situ hybridization (FISH).

RESULTS

at onset of disease, the patient was diagnosed as B-CLL, Rai stage is II. He was treated with a course of RF(fludarabine 50 mg×5, rituximab 600 mg×5) chemotherapy, and achived complete remission (CR) lasting for five years, then the patient was treated with multiple courses of chemotherapy and maintained at a steady state of disease. After the last chemotherapy, this patient developed a fever, his temperature fluctuated at 37.2-38.7°C, the lung CT showed the presence of massive shadow, repeated 1-3-β-D-glucan test was positive,and he was considered as invasive aspergillosis infection, voriconazole was intravenously injected him for 2 months, his lung CT showed better efficacy. However, the leukemia continued progress, his hemogram was extremely low, invasive aspergillosis infection relapsed,voriconazole treatment was poor effect,ultimately this patient died of the rapid progress of leukemia and multiple organ invasive aspergillosis. Autopsy showed chronic lymphocytic leukemia with multiple metastases and multiple organ invasive aspergillosis.

CONCLUSION

invasive aspergillosis is a serious complication for CLL patients,once occurs, the prognosis is poor,so early diagnosis and prophylactic antifungal therapy may reduce fungal infection complication.

CFD based investigation on the impact acceleration when a gannet impacts with water during plunge diving

Plunge diving is the most commonly used feeding method of a gannet, which can make the gannet transit from air to water rapidly and successfully. A large impact acceleration can be generated due to the air-to-water transition. However, the impact acceleration experienced by the gannet during plunge diving has not been studied. In this paper, this issue is investigated by using the CFD method. The effect of the dropping height and the water-entry inclination angle on the impact acceleration is considered. The results reveal that the impact acceleration along the longitudinal body axis increases with either of the two parameters. The peak time decreases with the dropping height. A quadratic relation is found between the peak impact acceleration and the initial water-entry velocity. According to the computation, when the dropping height is 30 m (most of gannets plunge from about this height), the peak impact acceleration can reach about 23 times the gravitational acceleration, which will exert a considerable force on the gannet body. Furthermore, the pressure distribution of different water-entry inclination angles indicates that the large pressure asymmetry caused by a small oblique angle may lead to a large impact acceleration in the direction perpendicular to the longitudinal body axis and cause damage to the neck of the gannet, which partly explains the reason why a gannet performing a high plunge diving in nature enters water with a large oblique angle from the perspective of impact mechanics. The investigation on the plunge-diving behavior in this paper will inspire and promote the development of a biomimetic amphibious robot that transits from air to water with the plunge-diving mode.

Hydrodynamic investigation of a self-propelled robotic fish based on a force-feedback control method

We implement a mackerel (Scomber scombrus) body-shaped robot, programmed to display the three most typical body/caudal fin undulatory kinematics (i.e. anguilliform, carangiform and thunniform), in order to biomimetically investigate hydrodynamic issues not easily tackled experimentally with live fish. The robotic mackerel, mounted on a servo towing system and initially at rest, can determine its self-propelled speed by measuring the external force acting upon it and allowing for the simultaneous measurement of power, flow field and self-propelled speed. Experimental results showed that the robotic swimmer with thunniform kinematics achieved a faster final swimming speed (St = 0.424) relative to those with carangiform (St = 0.43) and anguilliform kinematics (St = 0.55). The thrust efficiency, estimated from a digital particle image velocimetry (DPIV) flow field, showed that the robotic swimmer with thunniform kinematics is more efficient (47.3%) than those with carangiform (31.4%) and anguilliform kinematics (26.6%). Furthermore, the DPIV measurements illustrate that the large-scale characteristics of the flow pattern generated by the robotic swimmer with both anguilliform and carangiform kinematics were wedge-like, double-row wake structures. Additionally, a typical single-row reverse Karman vortex was produced by the robotic swimmer using thunniform kinematics. Finally, we discuss this novel force-feedback-controlled experimental method, and review the relative self-propelled hydrodynamic results of the robot when utilizing the three types of undulatory kinematics.

Retina-specific cis-elements and binding nuclear proteins of carp rhodopsin gene

The upstream cis-elements controlling the retina-specific expression of carp rhodopsin gene were fully characterized in vivo. Transgenic studies demonstrated that both carp neural retina leucine zipper response-like element (cNRE, within nucleotides (nt) -63 to -75) and carp-specific element (CSE, nt -46 to -52) were crucial to reporter gene expression in medaka retinae. The retina-specific expression rates of embryos injected with nt -1 to -641 and longer fragments were much higher than those of embryos injected with nt -1 to -138 and shorter fragments, indicating that an enhancer is located in the nt -138 to -641 region. Retinal extracts and the probe BAT-1 (nt -90 to -120) formed two DNA-protein complexes, B1 and B2. Retinal extracts and the probes cNRE and CSE formed the complexes N1 and C1, respectively. The protein factors in B1 and C1 were mammal-like cone-rod homeobox proteins.

One-stage correction of neglected developmental dysplasia of the hip by open reduction and pemberton osteotomy

BACKGROUND AND PURPOSE

Pemberton osteotomy is commonly used for correction of hip-dysplasia. Its application in treating hip dislocation is rarely reported. The purpose of this study was to determine the efficacy of one-stage open reduction and Pemberton osteotomy of neglected developmental dysplasia of the hip (DDH).

METHODS

We retrospectively reviewed the clinical and radiographic results of one-stage total correction in 75 patients with neglected DDH (86 hips) from 1984 through 1996. Sixty-nine patients (77 hips) aged 13 to 76 months (mean, 21.5 mo) underwent open reduction, Pemberton osteotomy, and hip spica for 8 weeks. Seven patients (9 hips) aged 29 to 73 months (mean, 46.6 mo) underwent additional femoral shortening (another hip in one bilaterally involved patient underwent only open reduction and Pemberton osteotomy).

RESULTS

Acetabular index improved markedly from 40.4 degrees (range, 25-60 degrees) preoperatively to 16.2 degrees (range, 0-30 degrees) postoperatively. Complications included redislocation in four patients (4 hips) and avascular necrosis in three patients (3 hips). Reoperation was performed in four patients (4 hips). All patients were followed up for at least 3 years. By Severin's classification, all operated hips had excellent (18) or good (68) final radiographic results. The functional results, evaluated by McKay's criteria, were also excellent (52 patients/60 hips) and good (23 patients/26 hips).

CONCLUSIONS

Neglected DDH was safely and effectively treated by open reduction, Pemberton osteotomy, and optional femoral shortening with limited complications.

Improvement of health outcomes after continued implementation of a clinical pathway for radical nephrectomy

The clinical pathway is an important tool for outcome management. We evaluated the overall effects of the continued implementation of a clinical pathway for radical nephrectomy on the length of hospital stay, admission charges, and the quality of medical care. The data obtained from the second-year implementation (group 3) of the clinical pathway were compared with the data from the first-year implementation (group 2) and the year preceding implementation (group 1). Thirty-seven consecutive patients with renal cell carcinoma underwent radical nephrectomy in group 1, 47 in group 2, and 55 in group 3; all were enrolled in this study. The length of hospital stay, average admission charges, and 8 quality indicators were measured in these patients. We also evaluated the variances in the implementation of the clinical pathway. The mean length of stay decreased by 14.0% (P = 0.0048) in group 2, and by 15.8% (P= 0.0014) in group 3, when compared to group 1. The total admission charges significantly decreased by 19.0% (P = 0.001) in group 2, and by 27.9% (P < 0.0001) in group 3, compared to the charges for group 1. A continued decrease in charges for operation and anesthesia, laboratory, pharmacy, and others were found 2 years after implementation of the clinical pathway. Among the 8 quality indicators, 2 were continuously improved in the second-year implementation of the clinical pathway, 2 were improved significantly in the second-year implementation only, and 4 showed no significant change at all. Variances from the clinical pathway decreased significantly after continued implementation. Continued implementation of the clinical pathway for radical nephrectomy can improve a physician's practice continuously by decreasing the length of hospital stay, admission charges, and variances, and by improving quality. However, the improved results after implementation of the clinical pathway should be maintained carefully to assure good health care.

Prolonged and enhanced suppression of thymidylate synthase by weekly 24-h infusion of high-dose 5-fluorouracil

We have recently demonstrated that HDFL (high-dose 5-FU 2600 mg m-2 week-1 and leucovorin 500 mg m-2 week-1, weekly 24-h infusion) is highly active in the treatment of gastric cancer. To further clarify the possible mechanism underlying the improved activity of HDFL compared with conventional 5-FU regimens, we conducted in vitro studies examining the effect of these regimens on the differential regulation of thymidylate synthase (TS) in NCI-N87, a human gastric cancer cell line. The expected serum concentrations of 5-FU are 100-200 mM (lasting for less than 30 min) and 5-10 mM (lasting for 24 h) for the conventional 5-FU regimens (bolus injection or short intravenous infusion of 5-FU 370-500 mg m-2) and the HDFL regimens, respectively. Western blot analysis revealed that 24-h exposure of NCI-N87 to 2.5-10.0 mM of 5-FU resulted in a dose-dependent depletion of free TS, lasting for more than 24 h. In contrast, 30-min exposure of NCI-N87 to 200 mM of 5-FU resulted in a less than 12-h depletion of free TS. Moreover, 24-h exposure to 5-FU resulted in a higher S-phase blockade and enhanced cytotoxicity. In both modes of 5-FU treatment, the initial rapid depletion of free TS was accompanied by a rapid increment of a higher-molecular-weight TS molecule, suggesting that rapid formation of the ternary complex was the key mechanism of 5-FU action during this period. Northern blot analysis showed that the steady-state mRNA of TS was not affected by either of the schedules. We conclude that 24-h exposure of gastric cancer cells to low concentration of 5-FU resulted in better suppression of free TS, a higher degree of S-phase blockade, and enhanced cytotoxicity compared to 30-min exposure to high concentration of 5-FU. These in vitro results may help explain the improved clinical efficacy of HDFL regimens compared to conventional 5-FU regimens.

Improvement of medical care quality after implementation of a clinical path monitoring program for transurethral prostatectomy patients

OBJECTIVES

The purpose of this study was to determine the effect on quality of care through the implementation of a clinical path for patients receiving transurethral prostatectomy.

METHODS

We selected ten quality indicators with important clinical relevance as representative elements of the clinical path. These quality indicators were monitored during the entire hospitalization period of 100 consecutive patients who received transurethral prostatectomy. Monitoring data obtained from these patients were compared to data from 100 patients who received transurethral prostatectomy prior to implementation of the clinical path. Data was assessed to determine the relationship between quality indicators and management processes.

RESULTS

Implementation of the clinical path for transurethral prostatectomy significantly decreased the percent of patients with incomplete preoperative tests on admission day, the duration of intravenous antibiotics administration, the percent of patients who required acute pain management postoperatively, the percent of patients who received postoperative bladder irrigation with normal saline and the percent of patients who had their Foley catheter removed after postoperative day 2. Three of the quality indicators had a significant relationship with management processes and may have directly affected the total admission charges.

CONCLUSIONS

To evaluate the effect of the transurethral prostatectomy clinical path implementation on the quality of medical care, we compared ten quality indicators before and after implementation of this path. We concluded that implementation of the clinical path resulted in a statistically significant improvement in the quality of medical care.