Margin to depth of invasion ratio as an indicator for stratifying close margins in early-stage oral squamous cell carcinoma

OBJECTIVES

In early-stage oral squamous cell carcinoma (OSCC) patients, whether the margin-to-depth-of-invasion ratio (MDR) can assist in stratifying the prognosis remains unclear.

METHODS

Patients diagnosed with early stage OSCC at National Taiwan University Hospital between January 2007 and December 2021 were reviewed. Patients with margin > 1 mm were classified into two groups: MDR < 0.5 and MDR ≥ 0.5.

RESULTS

We analyzed 911 pT1-2N0M0 OSCC patients, 723 (79.36 %) with MDR ≥ 0.5 and 188 (20.64 %) with MDR < 0.5. Patients in the MDR < 0.5 group displayed a significantly higher local recurrence rate (odds ratio 2.81, p = 0.002) compared with MDR ≥ 0.5 group. The 5-year disease-free survival were 80.8 % for clear margin, 76.3 % for close margin (MDR ≥ 0.5), and 65.2 % for close margin (MDR < 0.5). The overall survival displayed a similar pattern, with 5-year rates of 88.3 % for clear margin, 86.8 % for close margin (MDR ≥ 0.5), and 75.0 % for close margin (MDR < 0.5). There were no significant overall survival differences between the two MDR ≥ 0.5 groups, but both were significantly superior to patients with MDR < 0.5 (p = 0.001; p = 0.01). After multivariant cox analysis, MDR < 0.5 was a significant risk factor for disease-free survival (p < 0.001).

CONCLUSION

For early stage OSCC patients without positive margin (≦1mm), the survival outcome between MDR ≥ 0.5 group and MDR < 0.5 group was significantly different. The MDR < 0.5 group had significantly higher risk of local recurrence that may warrant adjuvant treatment.

Re-"Formate" T-cell Antitumor Responses

SUMMARY

Rowe and colleagues discover that one-carbon (1C) metabolism rewiring occurs upon T-cell activation to support proliferation and cytolytic activity in CD8+ T cells and that supplementation of 1C donor formate rescues the dysfunctional T cells and their responsiveness to anti-PD-1 in selective tumor-infiltrated T-cell subsets. This finding represents an attractive strategy to overcome a metabolic vulnerability in the tumor microenvironment and improve the efficacy of immune checkpoint blockade. See related article by Rowe et al., p. 2566 (8).

An Oral Microbial Biomarker for Early Detection of Recurrence of Oral Squamous Cell Carcinoma

Changes in the oral microbiome are associated with oral squamous cell carcinoma (OSCC). Oral microbe-derived signatures have been utilized as markers of OSCC. However, the structure of the oral microbiome during OSCC recurrence and biomarkers for the prediction of OSCC recurrence remains unknown. To identify OSCC recurrence-associated microbial biomarkers for the prediction of OSCC recurrence, we performed 16S rRNA amplicon sequencing on 54 oral swab samples from OSCC patients. Differences in bacterial compositions were observed in patients with vs without recurrence. We found that Granulicatella, Peptostreptococcus, Campylobacter, Porphyromonas, Oribacterium, Actinomyces, Corynebacterium, Capnocytophaga, and Dialister were enriched in OSCC recurrence. Functional analysis of the oral microbiome showed altered functions associated with OSCC recurrence compared with nonrecurrence. A random forest prediction model was constructed with five microbial signatures including Leptotrichia trevisanii, Capnocytophaga sputigena, Capnocytophaga, Cardiobacterium, and Olsenella to discriminate OSCC recurrence from original OSCC (accuracy = 0.963). Moreover, we validated the prediction model in another independent cohort (46 OSCC patients), achieving an accuracy of 0.761. We compared the accuracy of the prediction of OSCC recurrence between the five microbial signatures and two clinicopathological parameters, including resection margin and lymph node counts. The results predicted by the model with five microbial signatures showed a higher accuracy than those based on the clinical outcomes from the two clinicopathological parameters. This study demonstrated the validity of using recurrence-related microbial biomarkers, a noninvasive and effective method for the prediction of OSCC recurrence. Our findings may contribute to the prognosis and treatment of OSCC recurrence.

Spindle Cell Carcinoma of the Head and Neck: Clinical Characteristics and Molecular Signatures

OBJECTIVE/HYPOTHESIS

Spindle cell carcinoma of the head and neck (HNSpCC) is a rare variant of head and neck squamous cell carcinoma (HNSCC). This study evaluated the clinical characteristics and molecular signatures of such tumors.

STUDY DESIGN

Retrospective analysis.

METHODS

Medical records of patients diagnosed with HNSpCC from 1996 to 2018 were reviewed. The clinicopathologic features, treatment modalities, and survival status were carefully recorded. Whole exome sequencing (WES) was performed to evaluate the genetic signatures of HNSpCC.

RESULTS

We found that among all 71 patients included in this study, the majority of them were male, with tumors developing predominantly in the oral cavity. The 1-, 3-, and 5-year disease-specific survival (DSS) rates were 64.6%, 49.5%, and 43.9%, respectively. A high local recurrence (LR) and distant metastasis (DM) rate (47.9%-25.3%, respectively) were observed. A significant proportion (28.2%) of patients with the worst prognosis had history of previous head and neck cancer (HNC) and had been treated with radiotherapy (RT). WES revealed that those post-RT SpCC shared common mutations with their previous HNC (pre-RT SCC), but gained additional genetic traits, such as hypoxia and cell-ECM interaction that were favorable for survival in an irradiated microenvironment. Distinct genetic landscapes in primary and post-RT SpCC were also found.

CONCLUSIONS

This study demonstrates that HNSpCC is a unique entity with more aggressive behavior than conventional HNSCC. HNSpCC arising from a previously irradiated field is a predictor of dismal survival. Both genetic and microenvironmental factors contribute to this highly invasive tumor.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2183-2191, 2023.

Is the N2A Category Still Necessary for Oral Cancer Patients After Extranodal Extension Upgrade?

BACKGROUND

The presence of single-node metastasis (Ns) sometimes could be encountered in patients with oral squamous cell carcinoma (OSCC). The survival outcome for different Ns should be worthy of discussion.

METHODS

Patients diagnosed with OSCC at the National Taiwan University Hospital between January 2007 and December 2018 were reviewed. All patients with Ns were classified into two groups: with and without extranodal extension (ENE).

RESULTS

We analyzed 311 OSCC patients with Ns: 77 (24.76%) with and 234 (75.24%) without ENE. Lymph node (LN) >3 cm was the only significant factor associated with ENE (odds ratio 17.21, p < 0.001). The 5-year, disease-free survival of N₁/N_2A and N_3B patients was 60.5% and 49.4%, respectively (p = 0.04), and the 5-year overall survival was 63.1% and 33.6%, respectively (p = 0.0001). Four fifths of Ns patients with LN >3 cm were upgraded to N_3B category as ENE+. Postoperative radiotherapy (PORT) could provide significant benefit in regional control for Ns patients with (p = 0.03) and without (p = 0.0004) other adverse features. After multivariant Cox analysis, ENE+ was a modest and significant risk factor for disease-free (p = 0.08) and overall survival (p = 0.001). By contrast, the LN>3cm and N_2A category were not significant risk factors for disease-free and overall survival.

CONCLUSIONS

For OSCC patients with Ns, the survival outcome between N_3B category and N₁/N_2A category was significantly different. After ENE+ upgrades (>80%), there were fewer N_2A patients, and these patients became more comparable to N₁ patients. PORT could significantly improve regional control for Ns patients.

Truncation of GalNAc-type O-glycans suppresses CD44-mediated osteoclastogenesis and bone metastasis in breast cancer

The glycoprotein CD44 is a key regulator of malignant behaviors in breast cancer cells. To date, hyaluronic acid (HA)-CD44 signaling pathway has been widely documented in the context of metastatic bone diseases. Core 1 β1,3-galactosyltransferase (C1GALT1) is a critical enzyme responsible for the elongation of O-glycosylation. Aberrant O-glycans are recognized as a hallmark in cancers. However, the effects of C1GALT1 on CD44 signaling and bone metastasis remain unclear. In this study, immunohistochemical analysis indicated that C1GALT1 expression positively correlates with CD44 in breast cancer. Silencing C1GALT1 accumulates the Tn antigen on CD44, which decreases CD44 levels and osteoclastogenic signaling. Mutations in the O-glycosites on the stem region of CD44 impair its surface localization as well as suppress cell-HA adhesion and osteoclastogenic effects of breast cancer cells. Furthermore, in vivo experiments demonstrated the inhibitory effect of silencing C1GALT1 on breast cancer bone metastasis and bone loss. In conclusion, our study highlights the importance of O-glycans in promoting CD44-mediated tumorigenic signals and indicates a novel function of C1GALT1 in driving breast cancer bone metastasis. Implications: Truncation of GalNAc-type O-glycans by silencing C1GALT1 suppresses CD44-mediated osteoclastogenesis and bone metastasis in breast cancer; targeting the O-glycans on CD44 may serve as a potential therapeutic target for blocking cancer bone metastasis.

Chemoprevention of oral cancer: A review and future perspectives

BACKGROUND

Oral cancer causes significant morbidity and mortality. Chemoprevention utilizes medication or natural compounds to reverse oral premalignant lesions and to prevent second primary tumors.

METHODS

A comprehensive PubMed database and Cochrane Library search from 1980 to 2021 was performed using the keywords "leukoplakia," "oral premalignant lesion," and "chemoprevention."

RESULTS

Chemopreventive agents included retinoids, carotenoids, cyclooxygenase inhibitor, herbal extracts, bleomycin, tyrosine kinase inhibitors, metformin, and immune checkpoint inhibitors. Although some agents demonstrated effect in reducing premalignant lesions and preventing second primary tumors, the results among different studies were highly variable.

CONCLUSIONS

The results of different trials, albeit inconsistent, provided substantial information for future studies. In the era of personalized medicine, future studies will focus on identifying specific biomarkers and molecular profile to monitor and to prevent malignant transformation. Larger trials are warranted to validate the effect of chemopreventive agents.

Tardive sensory syndrome related to lurasidone: A case report

BACKGROUND

Tardive sensory syndrome (TSS) is a subtype of tardive syndrome (TS), and its etiology is still uncertain. Lurasidone is an atypical antipsychotic that has high affinity for dopamine D2- and serotonergic 5HT2A- and 5-HT7-receptors.

CASE SUMMARY

A 52-year-old woman, previously diagnosed with schizophrenia, and with no history of movement disorders and no sensory paresthesia, had taken lurasidone, initiate dose 40 mg daily then up titration to 120 mg daily, since March 2021, and developed mandibular sensory (pain) paresthesia after 3 mo of administration. After switching from lurasidone to quetiapine, she reported obvious impr-ovement in her mandibular pain.

CONCLUSION

It is noteworthy that TSS is a rare subtype of TS, and lurasidone, an atypical antipsychotic, usually has a lower risk of causing TS. In light of the temporal relationship, it is therefore concluded that use of lurasidone might have caused TSS in this patient. We reported this rare case as a reminder that clinicians should adopt a cautious approach when prescribing atypical antipsychotics, so as to prevent TS.

Radiation-induced sarcoma of head and neck: Clinical characteristics and molecular signatures

BACKGROUND

Radiation-induced sarcoma of the head and neck (RISHN) is a rare yet devastating potential complication of radiotherapy treatment. We aimed to evaluate the clinicopathological characteristics and molecular signatures of RISHN in patients who underwent radiotherapy for head and neck cancer (HNC) to identify high-risk patients and enable earlier cancer detection.

METHODS

This study retrospectively evaluated 24 sarcoma patients who received radiotherapy for HNC between 1994 and 2019. Patients were divided into two groups based on RISHN latency period. Patient demographics, initial tumor staging, risk factors, and survival between groups were analyzed, and whole-exome sequencing (WES) of selected samples was performed.

RESULTS

The median age at diagnosis of RISHN was 54 years, and the male-to-female ratio was 2:1. The latency period ranged from 0.8 to 64.4 years (median 6.5 years), with a median survival of 21.5 months. Primary cancer in the oral cavity, treatment with alkylating agents, alcohol consumption, betel nut chewing, and smoking were identified as risk factors for short (<5 years) latency periods. The majority of RISHN cases occurred in the oral cavity (58.3%). WES analysis showed that tumor necrosis factor and cell cycle checkpoint pathways were differentially involved in both patient groups.

CONCLUSIONS

Although case numbers were small, our cohort represents the largest case series of RISHN from a single institution to date. Clinicians must be aware of factors affecting RISHN development and latency, and risk factor identification may lead to earlier detection and prevention in the future.

The Ring Study: an international comparison of PD-L1 diagnostic assays and their interpretation in non-small cell lung cancer, head and neck squamous cell cancer and urothelial cancer

PD-L1 immunohistochemistry has been approved as a diagnostic assay for immunotherapy. However, an international comparison across multiple cancers is lacking. This study aimed to assess the performance of PD-L1 diagnostic assays in non-small cell lung cancer (NSCLC), head and neck squamous cell cancer (HNSCC) and urothelial cancer (UC). The excisional specimens of NSCLC, HNSCC and UC were assayed by Ventana SP263 and scored at three sites in each country, including Australia, Brazil, Korea, Mexico, Russia and Taiwan. All slides were rotated to two other sites for interobserver scoring. The same cohort of NSCLC was assessed with Dako 22C3 pharmDx PD-L1 for comparison. The PD-L1 immunopositivity was scored according to the approved PD-L1 scoring algorithms which were the percentage of PD-L1-expressing tumour cell (TC) and tumour proportion score (TPS) by Ventana SP263 and Dako 22C3 staining, respectively. In NSCLC, the comparison demonstrated the comparability of the SP263 and 22C3 assays (cut-off of 1%, κ=0.71; 25%, κ=0.75; 50%, κ=0.81). The interobserver comparisons showed moderate to almost perfect agreement for SP263 in TC staining at 25% cut-off (NSCLC, κ=0.72 to 0.86; HNSCC, κ=0.60 to 0.82; UC, κ=0.68 to 0.91) and at 50% cut-off for NSCLC (κ=0.64 to 0.90). Regarding the immune cell (IC) scoring in UC, there was a lower correlation (concordance correlation coefficient=0.10 to 0.68) and poor to substantial agreements at the 1%, 5%, 10% and 25% cut-offs (κ= -0.04 to 0.76). The interchangeability of SP263 and 22C3 in NSCLC might be acceptable, especially at the 50% cut-off. In HNSCC, the performance of SP263 is comparable across five countries. In UC, there was low concordance of IC staining, which may affect treatment decisions. Overall, the study showed the reliability and reproducibility of SP263 in NSCLC, HNSCC and UC.

Human tibial cortical bone with high porosity in type 2 diabetes mellitus is accompanied by distinctive bone material properties

Diabetes mellitus is a metabolic disease affecting bone tissue at different length-scales. Higher fracture risk in diabetic patients is difficult to detect with common clinical fracture risk assessment due to normal or high bone mineral density in diabetic patients. The observed higher fracture risk despite normal to high areal bone mineral density in diabetic patients points towards impaired bone material quality. Here, we analyze tibial bone from individuals with type 2 diabetes mellitus using a multiscale-approach, which includes clinical and laboratory-based bone quality measures. Tibial cortical bone tissue from individuals with type 2 diabetes mellitus (T2DM) and age-matched healthy controls (n = 15 each) was analyzed with in situ impact indentation, dual energy X-ray absorptiometry (DXA), high resolution peripheral microcomputed tomography (HR-pQCT), micro-computed tomography (microCT), cyclic indentation, quantitative backscattered electron microscopy (qBEI), vibrational spectroscopy (Raman), nanoindentation, and fluorescence spectroscopy. With this approach, a high cortical porosity subgroup of individuals with T2DM was discriminated from two study groups: individuals with T2DM and individuals without T2DM, while both groups were associated with similar cortical porosity quantified by means of microCT. The high porosity T2DM group, but not the T2DM group, showed compromised bone quality expressed by altered cyclic indentation properties (transversal direction) in combination with a higher carbonate-to-amide I ratio in endocortical bone. In addition, in the T2DM group with high cortical porosity group, greater cortical pore diameter was identified with HR-pQCT and lower tissue mineral density using microCT, both compared to T2DM group. Micromechanical analyses of cross-sectioned osteons (longitudinal direction) with cyclic indentation, qBEI, and nanoindentation showed no differences between the three groups. High tibial cortical porosity in T2DM can be linked to locally altered bone material composition. As the tibia is an accessible skeletal site for fracture risk assessment in the clinics (CT, indentation), our findings may contribute to further understanding the site-specific structural and compositional factors forming the basis of bone quality in diabetes mellitus. Refined diagnostic strategies are needed for a comprehensive fracture risk assessment in diabetic bone disease.

Investigation of Product Formation in the O(1D, 3P) + N2O Reactions: Comparison of Experimental and Theoretical Kinetics

The spin-forbidden and spin-allowed reactions of the excited and ground electronic state O(¹D, ³P) + N₂O(X¹Σ⁺) systems have been studied theoretically. Quantum calculations at the UCCSD(T)/CBS(T, Q, 5)//CCSD/aug-cc-pVTZ level have located two crossing points, MSX1 and MSX2, with energies of 11.2 and 22.7 kcal mol^-1 above O(³P) + N₂O, respectively. The second-order P-independent rate constants for the adiabatic and non-adiabatic thermal reactions predicted by adiabatic TST/VTST and non-adiabatic TST, respectively, agree closely with the available literature results. The second-order rate constant, k_2a = 9.55 × 10^-11 exp(-26.09 kcal mol^-1/RT) cm³ molecule^-1 s^-1, for the O(³P) + N₂O → 2NO reaction, contributed by both the dominant MSX2 and the minor TS1-a channels, is in reasonable accord with prior experiments and recommendations, covering the temperature range of 1200-4100 K. The calculated rate constant, k_2b = 4.47 × 10^-12 exp(-12.9 kcal mol^-1/RT) cm³ molecule^-1 s^-1, for the O(³P) + N₂O → N₂ + O₂(a¹Δ_g) reaction, occurring exclusively via MSX1, is also in good agreement with the combined experimental data measured in a shock tube study at T = 1940-3340 K (ref 16) and the result measured by Fourier transform infrared spectroscopy in the temperature range of 988-1083 K (ref 17). Moreover, the spin-allowed rate constants predicted for the singlet-state reactions, k_1a = (7.06-7.46) × 10^-11 cm³ molecule^-1 s^-1 for O(¹D) + N₂O → 2NO and k_1b = (4.36-4.66) × 10^-11 cm³ molecule^-1 s^-1 for O(¹D) + N₂O → N₂ + O₂(a¹Δ_g) in the temperature range of 200-350 K, agree quantitatively with the experimentally measured data, while the total rate constant k₁ = k_1a + k_1b was also found to be in excellent accordance with many reported values.

Aerosolized Hypertonic Saline Hinders Biofilm Formation to Enhance Antibiotic Susceptibility of Multidrug-Resistant Acinetobacter baumannii

Limited therapeutic options are available for multidrug-resistant Acinetobacter baumannii (MDR-AB), and the development of effective treatments is urgently needed. The efficacy of four aerosolized antibiotics (gentamicin, amikacin, imipenem, and meropenem) on three different MDR-AB strains was evaluated using hypertonic saline (HS, 7 g/100 mL) as the aerosol carrier. HS aerosol effectively hindered biofilm formation by specific MDR-AB strains. It could also interrupt the swarming dynamics of MDR-AB and the production of extracellular polymeric substances, which are essential for biofilm progression. Biofilms protect the microorganisms from antibiotics. The use of HS aerosol as a carrier resulted in a decreased tolerance to gentamicin and amikacin in the biofilm-rich MDR-AB. Moreover, we tested the aerosol characteristics of antibiotics mixed with HS and saline, and results showed that HS enhanced the inhaled delivery dose with a smaller particle size distribution of the four antibiotics. Our findings demonstrate the potential of using “old” antibiotics with our “new” aerosol carrier, and potentiate an alternative therapeutic strategy to eliminate MDR-AB infections from a biofilm-disruption perspective.

Adequate surgical margins for oral cancer: A Taiwan cancer registry national database analysis

BACKGROUND

Margin status and lymph node metastasis are the most important prognostic factors for oral cancers. However, while adequate surgical resection is crucial for local control and prognosis, the definition of clear margins has long been a subject of debate. In this study, we analyzed data from a nationwide population-based cancer registry database and evaluated the impact of surgical margins on cancer-specific survival (CSS) and overall survival (OS) as well as the optimal cutoff of adequate surgical margins.

METHODS

This analysis included all cases of oral cancer diagnosed from 2011 to 2017 that were reported to the Taiwan Cancer Registry database. The staging system was converted from American Joint Committee on Cancer (AJCC) version 7 to AJCC version 8. Kaplan-Meier analysis and Cox proportional-hazards regression were performed to identify covariates that were significantly associated with CSS and OS.

RESULTS

Between 2011 and 2017, 15,654 of a total of 36,091 cases diagnosed with oral cancers were included in the final analyses. Advanced N stage, positive margins, and advanced T stage are the leading risk factors for poor CSS and OS. When surgical margins were subdivided into 1-mm intervals from 5 mm to positive margin, we found that surgical margins <4 mm and <5 mm predict poor CSS and OS, respectively.

CONCLUSIONS

This is the first nationwide, population-based cohort to revisit the question of the adequate surgical margins for oral cancers. We conclude that surgical margins ≥4 mm and ≥5 mm are adequate for good CSS and OS, respectively.

Risk Factors and Genetic Biomarkers of Multiple Primary Cancers in Esophageal Cancer Patients

Esophageal cancer (EC) is a deadly cancer that frequently develops multiple primary cancers (MPCs). However, the risk biomarkers of MPC in EC have hardly been investigated. We retrospectively enrolled 920 subjects with primary EC and analyzed the possible risk factors as well as MPC single-nucleotide polymorphisms (SNPs) from blood DNA. A total of 184 subjects (20.0%) were confirmed to have MPC, 59 (32.8%) had synchronous MPC, and 128 (69.6%) had head and neck cancer. Elderly EC patients have an increased risk of having gastrointestinal cancer (Odds ratio, OR[95% CI]=6.70 [1.49-30.19], p=0.013) and a reduced risk of developing HNC (OR[95% CI]=0.44 [0.24-0.81], p=0.008). MPC risk was also associated with betel nut chewing (OR[95% CI]=1.63, 1.14-2.32], p=0.008), the A allele of ALDH2:rs671 (p=0.074 and 0.030 for GA and AA, respectively), the CC genotype in CISH:rs2239751 (OR[95% CI]=1.99 [1.2-3.32], p=0.008), and the G allele of ERCC5:rs17655 (p=0.001 and 0.090 for GC and CC, respectively). ADH1B:rs1229984 also correlated with MPC risk (p=0.117). Patients carrying four risk SNPs had a 40-fold risk of MPC (OR[95% CI]=40.25 [6.77-239.50], p<0.001) and a 12.57-fold risk of developing second primary cancer after EC (OR[95% CI]=12.57 [1.14-138.8], p=0.039) compared to those without any risk SNPs. In conclusion, hereditary variations in ALDH2, CISH, ERCC5, and ADH1B have great potential in predicting the incidence of MPC in EC patients. An extensive cancer screening program during clinical follow-up would be beneficial for patients with high MPC susceptibility.

Anti-C1GALT1 Autoantibody Is a Novel Prognostic Biomarker for Patients With Head and Neck Cancer

OBJECTIVES

The objective of this study is to determine the value of the anti- glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1) autoantibody as a biomarker for distant metastasis and good response to immune checkpoint inhibitors in patients with head and neck squamous cell carcinoma (HNSCC).

METHODS

In this retrospective study with a median follow-up of 55.7 months, 186 HNSCC patients were enrolled between July 2013 and August 2014. Data were analyzed between April 2018 and November 2019. Titers of autoantibody against the C1GALT1 peptide were measured by ELISA. Student t test, Kaplan-Meier analysis, and univariate and multivariate Cox proportional hazard models were used to evaluate the association of anti-C1GALT1 autoantibody titer with clinicopathologic factors, survival, and response to immunotherapy.

RESULTS

Our results showed that high levels of the anti-C1GALT1 autoantibody is an independent marker for distant metastasis and poor disease-specific survivals in HNSCC patients. In 19 recurrent or metastatic (R/M) HNSCC patients who have received nivolumab or pembrolizumab, higher autoantibody titers are associated with a better treatment response.

CONCLUSION

We propose that the anti-C1GALT1 autoantibody can serve as a novel biomarker for distant metastasis in HNSCC patients. It is also useful in individualized medicine for R/M HNSCC patients who are considering immunotherapy.

LEVEL OF EVIDENCE

IV Laryngoscope, 131:E196-E202, 2021.

C1GALT1 is associated with poor survival and promotes soluble Ephrin A1-mediated cell migration through activation of EPHA2 in gastric cancer

C1GALT1 controls the crucial step of GalNAc-type O-glycosylation and is associated with both physiologic and pathologic conditions, including cancers. EPH receptors comprise the largest family of receptor tyrosine kinases (RTKs) and modulate a diverse range of developmental processes and human diseases. However, the role of C1GALT1 in the signaling of EPH receptors remains largely overlooked. Here, we showed that C1GALT1 high expression in gastric adenocarcinomas correlated with adverse clinicopathologic features and is an independent prognostic factor for poor overall survival. Silencing or loss of C1GALT1 inhibited cell viability, migration, invasion, tumor growth and metastasis, as well as increased apoptosis and cytotoxicity of 5-fluorouracil in AGS and MKN45 cells. Phospho-RTK array and western blot analysis showed that C1GALT1 depletion suppressed tyrosine phosphorylation of EPHA2 induced by soluble Ephrin A1-Fc. O-glycans on EPHA2 were modified by C1GALT1 and both S277A and T429A mutants, which are O-glycosites on EPHA2, dramatically enhanced phosphorylation of Y588, suggesting that not only overall O-glycan structures but also site-specific O-glycosylation can regulate EPHA2 activity. Furthermore, depletion of C1GALT1 decreased Ephrin A1-Fc induced migration and reduced Ephrin A1 binding to cell surfaces. The effects of C1GALT1 knockdown or knockout on cell invasiveness in vitro and in vivo were phenocopied by EPHA2 knockdown in gastric cancer cells. These results suggest that C1GALT1 promotes phosphorylation of EPHA2 and enhances soluble Ephrin A1-mediated migration primarily by modifying EPHA2 O-glycosylation. Our study highlights the importance of GalNAc-type O-glycosylation in EPH receptor-regulated diseases and identifies C1GALT1 as a potential therapeutic target for gastric cancer.

Potassium-Presenting Zinc Oxide Surfaces Induce Vertical Phase Separation in Fullerene-Free Organic Photovoltaics

Bulk heterojunction (BHJ) structure based organic photovoltaics (OPVs) have recently showed great potential for achieving high power conversion efficiencies (PCEs). An ideal BHJ structure would feature large donor/acceptor interfacial areas for efficient exciton dissociation and gradient distributions with high donor and acceptor concentrations near the anode and cathode, respectively, for efficient charge extraction. However, the random mixing of donors and acceptors in the BHJ often suffers the severe charge recombination in the interface, resulting in poor charge extraction. Herein, we propose a new approach-treating the surface of the zinc oxide (ZnO) as an electron transport layer with potassium hydroxide-to induce vertical phase separation of an active layer incorporating the nonfullerene acceptor IT-4F. Density functional theory calculations suggested that the binding energy difference between IT-4F and the PBDB-T-2Cl, to the potassium (K)-presenting ZnO interface, is twice as strong as that for IT-4F and PBDB-T-2Cl to the untreated ZnO surface, such that it would induce more IT-4F moving toward the K-presenting ZnO interface than the untreated ZnO interface thermodynamically. Benefiting from efficient charge extraction, the best PCEs increased to 12.8% from 11.8% for PBDB-T-2Cl:IT-4F-based devices, to 12.6% from 11.6% for PBDB-T-2Cl:Y1-4F-based devices, to 13.5% from 12.2% for PBDB-T-2Cl:Y6-based devices, and to 15.7% from 15.1% for PM6:Y6-based devices.

Computational Study on the Mechanisms and Rate Constants for the O(3P,1D) + OCS Reactions

The mechanisms and kinetics of O(³P,¹D) + OCS(X¹Σ⁺) reactions have been studied by the high-level G2M(CC2) and CCSD(T)/6-311+G(3df)//B3LYP/6-311+G(3df) methods in conjunction with the transition-state theory and variational Rice-Ramsperger-Kassel-Marcus theory calculations. The result shows that the triplet surface proceeds directly by abstraction and substitution channels to produce SO(³P) + CO(X¹Σ⁺) and S(³P) + CO₂(X¹ Σ_g⁺) by passing the barriers of 7.6 and 9.1 kcal·mol^-1 at the G2M(CC2)//B3LYP/6-311+G(3df) level, respectively, while two stable intermediates, LM1 (OSCO¹) and LM2 (SC(O)O¹), are formed barrierlessly from O(¹D) + OCS(X¹Σ⁺) in the singlet surface, which lie at -40.5 and -50.1 kcal·mol^-1 relative to O(³P) + OCS(X¹Σ⁺) reactants and decompose to CO(X¹Σ⁺) + SO(a¹Δ) and S(¹D) + CO₂(X¹Σ_g⁺). LM1 and LM2 may also be produced by singlet-triplet surface crossings via MSX1 and MSX2; the predicted total rate constant for the O(³P) + OCS(X¹Σ⁺) reaction including the crossings, 9.2 × 10^-11 exp(-5.18 kcal·mol^-1/RT) cm³ molecule^-1 s^-1, is in good agreement with available experimental data. The branching ratio of the CO₂ product channel, 0.22-0.32, between 1200 and 1600 K, is also in excellent agreement with the value of 0.2-0.3 measured by Isshiki et al. (J. Phys. Chem. A. 2003, 107, 2464).

Hand strength and dexterity in patients with Prader-Willi syndrome: a pilot intervention study

OBJECTIVE

The study aim was to examine the hand function (hand strength and dexterity) and intervention effects of training in adults with Prader-Willi syndrome (PWS).

METHODS

Six adults with PWS (two females; mean age 26.14 years) underwent hand muscle strength and dexterity training for 3 months (2 hours per week). The following hand function tests were performed pre- and post-intervention: (1) hand grip, lateral pinch, and tip pinch hand strength tests, (2) the Box and Block test (BBT) for gross manual dexterity and (3) the Purdue Pegboard test for finger dexterity.

RESULTS

Before treatment, all subjects showed lower hand grip, lateral pinch, tip pinch strength, and poorer manual/finger dexterity relative to healthy adults. After training, hand function scores improved on many test items, but only the left hand tip pinch and the right hand BBT performance showed significant improvements.

CONCLUSIONS

All subjects showed lower hand strength and poorer manual/finger dexterity compared with healthy adults; this should be considered during physical training programs. Owing to limitations in the intervention intensity and possible subject behavioral deficits, further research is needed to clarify the effects of this intervention on hand function in PWS patients.

Silencing of MUC20 suppresses the malignant character of pancreatic ductal adenocarcinoma cells through inhibition of the HGF/MET pathway

Mucins are heavily glycosylated proteins that play critical roles in the pathogenesis of tumour malignancies. Pancreatic ductal adenocarcinoma (PDAC) is characterised by the aberrant expression of mucins. However, the role of mucin (MUC) 20 in PDAC remains unclear. PDAC is usually surrounded by a dense fibrotic stroma consisting of an extracellular matrix and pancreatic stellate cells (PSCs). The stroma creates a nutrient-deprived, hypoxic, and acidic microenvironment, and promotes the malignant behaviours of PDAC cells. In this study, immunohistochemical staining demonstrated that high MUC20 expression correlated with poor progression-free survival and high local recurrence rate of PDAC patients (n = 61). The expression of MUC20 was induced by serum deprivation, hypoxia, and acidic pH in PDAC cells. MUC20 knockdown with siRNA decreased cell viability, as well as migration and invasion induced by PSCs in HPAC and HPAF-II cells. In intraperitoneal, subcutaneous, and orthotopic injection models, MUC20 knockdown decreased tumour growth in immunodeficient mice. Phospho-RTK array and western blot analysis indicated that MUC20 knockdown decreased HGF-mediated phosphorylation of MET in PDAC cells. Moreover, HGF-induced malignant phenotypes could be suppressed by MUC20 knockdown. Co-immunoprecipitation revealed the physical association of MUC20 and MET. These findings suggest that MUC20 knockdown suppresses the malignant phenotypes of PDAC cells at least partially through the inhibition of the HGF/MET pathway and that MUC20 could act as a potential therapeutic target.

Consensus and clinical recommendations for nutritional intervention for head and neck cancer patients undergoing chemoradiotherapy in Taiwan

Because of the anatomical location, patients with head and neck cancer (HNC) frequently experience dysphagia and malnutrition at the time of diagnosis and these conditions are often exacerbated after chemoradiotherapy. There is an emerging medical need to establish a consensus on nutritional intervention for these patients. A panel of 30 senior physicians and experts from multidisciplinary teams drafted clinical recommendations to improve the management of nutritional interventions in Taiwan and to provide updated treatment strategy recommendations in hope of improving the nutritional status of patients with HNC. This clinical review describes the resulting consensus document, including the impact of malnutrition on clinical outcomes, the role of prophylactic tube feeding, the choice of tube feeding, and the benefit of oral nutritional supplements in patients with HNC undergoing chemoradiotherapy. The outcomes of this review will support clinicians in their efforts to improve the nutritional status of patients with HNC.

Carbon-doped SnS2 nanostructure as a high-efficiency solar fuel catalyst under visible light

Photocatalytic formation of hydrocarbons using solar energy via artificial photosynthesis is a highly desirable renewable-energy source for replacing conventional fossil fuels. Using an L-cysteine-based hydrothermal process, here we synthesize a carbon-doped SnS₂ (SnS₂-C) metal dichalcogenide nanostructure, which exhibits a highly active and selective photocatalytic conversion of CO₂ to hydrocarbons under visible-light. The interstitial carbon doping induced microstrain in the SnS₂ lattice, resulting in different photophysical properties as compared with undoped SnS₂. This SnS₂-C photocatalyst significantly enhances the CO₂ reduction activity under visible light, attaining a photochemical quantum efficiency of above 0.7%. The SnS₂-C photocatalyst represents an important contribution towards high quantum efficiency artificial photosynthesis based on gas phase photocatalytic CO₂ reduction under visible light, where the in situ carbon-doped SnS₂ nanostructure improves the stability and the light harvesting and charge separation efficiency, and significantly enhances the photocatalytic activity.

Ni-Nanocluster Modified Black TiO2 with Dual Active Sites for Selective Photocatalytic CO2 Reduction

One of the key challenges in artificial photosynthesis is to design a photocatalyst that can bind and activate the CO₂ molecule with the smallest possible activation energy and produce selective hydrocarbon products. In this contribution, a combined experimental and computational study on Ni-nanocluster loaded black TiO₂ (Ni/TiO_2[Vo] ) with built-in dual active sites for selective photocatalytic CO₂ conversion is reported. The findings reveal that the synergistic effects of deliberately induced Ni nanoclusters and oxygen vacancies provide (1) energetically stable CO₂ binding sites with the lowest activation energy (0.08 eV), (2) highly reactive sites, (3) a fast electron transfer pathway, and (4) enhanced light harvesting by lowering the bandgap. The Ni/TiO_2[Vo] photocatalyst has demonstrated highly selective and enhanced photocatalytic activity of more than 18 times higher solar fuel production than the commercial TiO₂ (P-25). An insight into the mechanisms of interfacial charge transfer and product formation is explored.

Molecular ReI Cages: Structural and Luminescent Properties

Versatile building block [{Re(CO)₄ }₃ (C₃ N₃ S₃ )] (1 a; C₃ N₃ S₃ =cyanurate trianion) reacts with linear dipyridyl ligands [i.e., pyrazine (pz), 4,4'-bipyridine (bpy), 1,2-bis(4-pyridyl)ethylene (bpe), bis(4-pyridyl)acetylene (bpa), and 1,4-bis(pyridyl-4-ylethynyl)benzene (bpb)] and a tripyridyl ligand [1,3,5-tris(4-pyridylethynyl)benzene (tpb)] to afford a series of molecular cages [{Re(CO)₃ }₆ (L)₃ (C₃ N₃ S₃ )₂ ] [L=pz (2), bpy (3), bpe (4), bpa (5), bpb (6)] and [{Re(CO)₃ }₉ (tpb)₃ (C₃ N₃ S₃ )₃ ] (7) under solvothermal conditions. Various structural dimensions and motifs can be systematically tuned and obtained by using different dipyridyl and tripyridyl ligands in the reactions. The molecular cages of hexanuclear complexes 2-6 containing dipyridyl ligands feature interesting trigonal-prismatic structures with different dimensions. Furthermore, nonanuclear complex 7 has a novel triangular-star structure, and three benzene rings of tpb ligands form a triple-decker arrangement with significant π⋅⋅⋅π interactions having distances of 3.490(1) and 3.528(1) Å. In addition, molecular cages 1-3 and 5-7 exhibit luminescence in the solid state, and their luminescent properties were also studied.

Therapeutic vaccine targeting Epstein-Barr virus latent protein, LMP1, suppresses LMP1-expressing tumor growth and metastasis in vivo

Background

In endemic area, nasopharyngeal carcinoma (NPC) tumor cells harbor EBV latent infection and expresses viral antigens such as EBNA1, LMP1 and LMP2. In this study, we established a NPC-mimicry animal model and assessed the therapeutic potential of LMP1 vaccine.

Methods

Animal models were established by injection of LMP1-expressing TC-1 cells in C57BL6/J mice subcutaneously or through tail veins. pcDNA3.1 empty vector or LMP1/pcDNA3.1 vaccine was delivered by a helium-driven gene gun. Effectiveness of vaccine was evaluated by measuring the tumor size and numbers of metastatic lung nodules. Circulating cytokines were evaluated by ELISArray. Populations of activated cytotoxic T lymphocytes (CTLs) and LMP1-specific T lymphocytes were evaluated by flow cytometry with CD8/CD107a double staining and interferon-γ ELISPOT assay, respectively.

Results

LMP1 vaccine significantly suppressed tumor growth (n = 3) and metastasis (n = 4) in vivo. When vaccinated before tumor challenge, all mice in vaccine group were tumor-free, whereas all mice in the control group developed tumors within 2 weeks after tumor challenge (n = 10). Cytokine ELISArray revealed elevation of a panel of proinflammatory cytokines in mice receiving LMP1 vaccine. Flow cytometry and interferon-γ ELISPOT assay revealed that LMP1 vaccine induced larger populations of activated CTLs and LMP1-specific T lymphocytes.

Conclusions

This pre-clinical study provides a promising result that LMP1 vaccine suppresses LMP1-expressing tumor growth and metastasis in vivo.

Quantum chemical investigation on the role of Li adsorbed on anatase (101) surface nano-materials on the storage of molecular hydrogen

Lithiation of TiO2 has been shown to enhance the storage of hydrogen up to 5.6 wt% (Hu et al. J Am Chem Soc 128:11740-11741, 2006). The mechanism for the process is still unknown. In this work we have carried out a study on the adsorption and diffusion of Li atoms on the surface and migration into subsurface layers of anatase (101) by periodic density functional theory calculations implementing on-site Coulomb interactions (DFT+U). The model consists of 24 [TiO2] units with 11.097 × 7.655 Å(2) surface area. Adsorption energies have been calculated for different Li atoms (1-14) on the surface. A maximum of 13 Li atoms can be accommodated on the surface at two bridged O, Ti-O, and Ti atom adsorption sites, with 83 kcal mol(-1) adsorption energy for a single Li atom adsorbed between two bridged O atoms from where it can migrate into the subsurface layer with 27 kcal mol(-1) energy barrier. The predicted adsorption energies for H2 on the lithiated TiO2 (101) surface with 1-10 Li atoms revealed that the highest adsorption energies occurred on 1-Li, 5-Li, and 9-Li surfaces with 3.5, 4.4, and 7.6 kcal mol(-1), respectively. The values decrease rapidly with additional H2 co-adsorbed on the lithiated surfaces; the maximum H2 adsorption on the 9Li-TiO2(a) surface was estimated to be only 0.32 wt% under 100 atm H2 pressure at 77 K. The result of Bader charge analysis indicated that the reduction of Ti occurred depending on the Li atoms covered on the TiO2 surface.

Reaction dynamics of O(¹D) + HCOOD/DCOOH investigated with time-resolved Fourier-transform infrared emission spectroscopy

We investigated the reaction dynamics of O((1)D) towards hydrogen atoms of two types in HCOOH. The reaction was initiated on irradiation of a flowing mixture of O3 and HCOOD or DCOOH at 248 nm. The relative vibration-rotational populations of OH and OD (1 ≦ v ≦ 4, J ≤ 15) states were determined from time-resolved IR emission recorded with a step-scan Fourier-transform spectrometer. In the reaction of O((1)D) + HCOOD, the rotational distribution of product OH is nearly Boltzmann, whereas that of OD is bimodal. The product ratio [OH]/[OD] is 0.16 ± 0.05. In the reaction of O((1)D) + DCOOH, the rotational distribution of product OH is bimodal, but the observed OD lines are too weak to provide reliable intensities. The three observed OH/OD channels agree with three major channels of production predicted with quantum-chemical calculations. In the case of O((1)D) + HCOOD, two intermediates HOC(O)OD and HC(O)OOD are produced in the initial C-H and O-D insertion, respectively. The former undergoes further decomposition of the newly formed OH or the original OD, whereas the latter produces OD via direct decomposition. Decomposition of HOC(O)OD produced OH and OD with similar vibrational excitation, indicating efficient intramolecular vibrational relaxation, IVR. Decomposition of HC(O)OOD produced OD with greater rotational excitation. The predicted [OH]/[OD] ratio is 0.20 for O((1)D) + HCOOD and 4.08 for O((1)D) + DCOOH; the former agrees satisfactorily with experiments. We also observed the v3 emission from the product CO2. This emission band is deconvoluted into two components corresponding to internal energies E = 317 and 96 kJ mol(-1) of CO2, predicted to be produced via direct dehydration of HOC(O)OH and secondary decomposition of HC(O)O that was produced via decomposition of HC(O)OOH, respectively.

Instability of succinate dehydrogenase in SDHD polymorphism connects reactive oxygen species production to nuclear and mitochondrial genomic mutations in yeast

AIMS

Mitochondrial succinate dehydrogenase (SDH) is an essential complex of the electron transport chain and tricarboxylic acid cycle. Mutations in the human SDH subunit D frequently lead to paraganglioma (PGL), but the mechanistic consequences of the majority of SDHD polymorphisms have yet to be unraveled. In addition to the originally discovered yeast SDHD subunit Sdh4, a conserved homolog, Shh4, has recently been identified in budding yeast. To assess the pathogenic significance of SDHD mutations in PGL patients, we performed functional studies in yeast.

RESULTS

SDHD protein expression was reduced in SDHD-related carotid body tumor tissues. A BLAST search of SDHD to the yeast protein database revealed a novel protein, Shh4, that may have a function similar to human SDHD and yeast Sdh4. The missense SDHD mutations identified in PGL patients were created in Sdh4 and Shh4, and, surprisingly, a severe respiratory incompetence and reduced expression of the mutant protein was observed in the sdh4Δ strain expressing shh4. Although shh4Δ cells showed no respiratory-deficient phenotypes, deletion of SHH4 in sdh4Δ cells further abolished mitochondrial function. Remarkably, sdh4Δ shh4Δ strains exhibited increased reactive oxygen species (ROS) production, nuclear DNA instability, mtDNA mutability, and decreased chronological lifespan.

INNOVATION AND CONCLUSION

SDHD mutations are associated with protein and nuclear and mitochondrial genomic instability and increase ROS production in our yeast model. These findings reinforce our understanding of the mechanisms underlying PGL tumorigenesis and point to the yeast Shh4 as a good model to investigate the possible pathogenic relevance of SDHD in PGL polymorphisms.

MiR-29c mediates epithelial-to-mesenchymal transition in human colorectal carcinoma metastasis via PTP4A and GNA13 regulation of β-catenin signaling

BACKGROUND

Distant metastasis is the major cause of cancer-related death, and epithelial-to-mesenchymal transition (EMT) has a critical role in this process. Accumulating evidence indicates that EMT can be regulated by microRNAs (miRNAs). miR-29c has been implicated as a tumor suppressor in several human cancers. However, the role of miR-29c in the progression of colorectal cancer (CRC) metastasis remains largely unknown.

PATIENTS AND METHODS

The expression of miR-29c was examined by qRT-PCR in a cohort of primary CRC (PC) and distant liver metastasis (LM) tissues. A series of in vivo and in vitro assays were carried out in order to elucidate the functions of miR-29c and the molecular mechanisms underlying the pathogenesis of metastatic CRC.

RESULTS

miR-29c was markedly downregulated in PCs with distant metastasis and determined to be an independent predictor of shortened patient survival. But LM tissues showed higher levels of miR-29c than that in PC tissues. In CRC cells, miR-29c dramatically suppressed cell migration and invasion abilities in vitro and cancer metastasis in vivo. In addition, miR-29c inhibited EMT and negatively regulated Wnt/β-catenin signaling pathway. Guanine nucleotide binding protein alpha13 (GNA13) and protein tyrosine phosphatase type IVA (PTP4A) were identified as direct targets of miR-29c, which acted through ERK/GSK3β/β-catenin and AKT/GSK3β/β-catenin pathways, respectively, to regulate EMT. Furthermore, significant associations between miR-29c, its target genes (GNA13 and PTP4A) and EMT markers were validated in both PC and LM tissues.

CONCLUSION

Our findings highlight the important role of miR-29c in regulating CRC EMT via GSK-3β/β-catenin signaling by targeting GNA13 and PTP4A and provide new insights into the metastatic basis of CRC.

GALNT2 enhances migration and invasion of oral squamous cell carcinoma by regulating EGFR glycosylation and activity

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is one of the leading cancers worldwide. Aberrant glycosylation affects many cellular properties in cancers, including OSCC. This study aimed to explore the role of N-acetylgalactosaminyltransferase 2 (GALNT2) in OSCC.

MATERIALS AND METHODS

Immunohistochemistry was performed to study the expression of GALNT2 in an OSCC tissue microarray. Effects of GALNT2 overexpression and knockdown on cell migration and invasion were analyzed in SAS cells by transwell migration assay and matrigel invasion assay, respectively. The Vicia villosa agglutinin (VVA) pull down assay was conducted to detect changes in O-glycans on acceptor substrates of GALNT2. Cell signaling was analyzed by Western blotting.

RESULTS

GALNT2 was overexpressed in 73% (35/48) of OSCC tissues. Moreover, GALNT2 expression was localized in the invasive front and increased in high grade OSCC. GALNT2 overexpression enhanced migration and invasion of SAS cells triggered by fetal bovine serum (FBS) and epidermal growth factor (EGF). In contrast, GALNT2 knockdown inhibited SAS cell migration and invasion. Furthermore, GALNT2 overexpression enhanced VVA binding to epidermal growth factor receptor (EGFR) and EGF-induced phosphorylation of EGFR and AKT. Conversely, GALNT2 knockdown decreased VVA binding and suppressed activity of EGFR and AKT.

CONCLUSION

GALNT2 is frequently overexpressed in OSCC, especially in the carcinoma cells at the invasive front. GALNT2 overexpression enhances the invasive potential of OSCC cells via modifying O-glycosylation and activity of EGFR. These findings suggest that GALNT2 plays an important role in the invasive behavior of OSCC and that targeting GALNT2 could be a promising approach for OSCC therapy.

Detection of human JCPyV and BKPyV in diffuse large B-cell lymphoma of the GI tract

Previous studies have demonstrated that infection with human polyomavirus, such as JCPyV and BKPyV, might be associated with various human tumors. However, an association between human JCPyV and BKPyV infection and diffuse large B-cell lymphoma (DLBCL) has not been reported. The purpose of this study was to examine DLBCLs of the gastrointestinal tract for evidence of human polyomavirus infection. Nested PCR and DNA sequencing were employed for viral DNA detection and viral genotype identification. In addition, two viral proteins, the large tumor antigen (LT) and the major structural protein (VP1), were detected by immunohistochemistry (IHC). Human JCPyV and BKPyV DNA was detected in 14 out of 16 tissue samples (87.5%), whereby nine cases were infected with JCPyV and five cases were infected with BKPyV. Both archetypal and rearranged genotypes of JCPyV and BKPyV were detected in the tissues. LT was detected in 11 tissue samples (68.75%). However, VP1 was not detected in any of the tissue samples. The presence of human JCPyV and BKPyV DNA and protein in DLBCL tissues of gastrointestinal tract were first reported in this study. The current results provide evidence of a possible association between human JCPyV and BKPyV infection and DLBCL.

Detection of human JCPyV and BKPyV in diffuse large B-cell lymphoma of the GI tract

Previous studies have demonstrated that infection with human polyomavirus, such as JCPyV and BKPyV, might be associated with various human tumors. However, an association between human JCPyV and BKPyV infection and diffuse large B-cell lymphoma (DLBCL) has not been reported. The purpose of this study was to examine DLBCLs of the gastrointestinal tract for evidence of human polyomavirus infection. Nested PCR and DNA sequencing were employed for viral DNA detection and viral genotype identification. In addition, two viral proteins, the large tumor antigen (LT) and the major structural protein (VP1), were detected by immunohistochemistry (IHC). Human JCPyV and BKPyV DNA was detected in 14 out of 16 tissue samples (87.5%), whereby nine cases were infected with JCPyV and five cases were infected with BKPyV. Both archetypal and rearranged genotypes of JCPyV and BKPyV were detected in the tissues. LT was detected in 11 tissue samples (68.75%). However, VP1 was not detected in any of the tissue samples. The presence of human JCPyV and BKPyV DNA and protein in DLBCL tissues of gastrointestinal tract were first reported in this study. The current results provide evidence of a possible association between human JCPyV and BKPyV infection and DLBCL.

Ab initio chemical kinetics for SiH2 + Si2H6 and SiH3 + Si2H5 reactions and the related unimolecular decomposition of Si3H8 under a-Si/H CVD conditions

The kinetics and mechanisms for SiH2 + Si2H6 and SiH3 + Si2H5 reactions and the related unimolecular decomposition of Si3H8 have been investigated by ab initio molecular orbital theory based on the QCISD(T)/CBS//QCISD/6-311++G(d,p) method in conjunction with quantum statistical variational Rice-Ramsperger-Kassel-Marcus (RRKM) calculations. For the barrierless radical association processes, their variational transition states have been characterized by the CASPT2//CASSCF method. The species involved in the study are known to coexist under CVD conditions. The results show that the association reaction of SiH2 and Si2H6 producing Si3H8 occurs by insertion via its lowest-energy path forming a loose hydrogen-bonding molecular complex with 8.3 kcal/mol binding energy; the reaction is exothermic by 55.0 kcal/mol. The chemically activated Si3H8 adduct can fragment by several paths, producing SiH4 + SiH3SiH (-0.7 kcal/mol), Si(SiH3)2 + H2 (-1.4 kcal/mol), and SiH3SiH2SiH + H2 (-1.4 kcal/mol). The predicted enthalpy changes as given agree well with available thermochemical data. Three other decomposition channels of Si3H8 occurring by Si-H or Si-Si breaking were found to be highly endothermic, and the reactions take place without a well-defined barrier. The heats of formation of Si3H8, SiH2SiH, Si2H4, i-Si3H7, n-Si3H7, Si(SiH3)2, and SiH3SiH2SiH have been predicted and found to be in close agreement with those available data in the literature. The product branching rate constants for SiH2 + Si2H6 and SiH3 + Si2H5 reactions and the thermal unimolecular decomposition of Si3H8 for all low-energy paths have been calculated with multichannel variational RRKM theory covering varying P,T conditions typically employed in PECVD and Cat-CVD processes for hydrogenated amorphous silicon (a-Si/H) film growth. The results were also found to be in good agreement with available kinetic data. Our kinetic results may be employed to model and control very large-area a-Si/H film growth for a new generation of solar cell applications.

Dental diagnostic X-ray exposure and risk of benign and malignant brain tumors

BACKGROUND

This study evaluates the risk of benign brain tumors (BBTs) and malignant brain tumors (MBTs) associated with dental diagnostic X-ray, using a large population-based case-control study.

MATERIALS AND METHODS

We identified 4123 BBT cases and 16 492 controls without BBT (study 1) and 197 MBT cases and 788 controls without MBT (study 2) from Taiwan National Health Insurance claim data. The risks of both types of tumor were estimated in association with the frequency of received dental diagnostic X-ray.

RESULTS

The mean ages were ~44.2 years in study 1 and 40.6 years in study 2. Multivariable unconditional logistic regression analysis showed that the risk of BBT increases as the frequency of received dental diagnostic X-ray increases. The BBT odds ratio increased from 1.33 [95% confidence interval (CI) 1.22-1.44] for those with annual mean X-ray examination of less than one to 1.65 (95% CI 1.37-1.98) for those with three or more X-ray examinations, after controlling for comorbidities. No significant association was found between MBTs and dental diagnostic X-ray exposure.

CONCLUSIONS

Exposure to dental diagnostic X-rays in oral and maxillofacial care increases the risk of BBTs, but not MBTs.

Effects of [123I]ADAM, a serotonin transporter radiopharmaceutical, on pregnant Sprague-Dawley rats

Serotonin transport abnormalities are implicated in neuropsychiatric disorders. [(123)I]ADAM ([(123)I]-2-([2-({dimethylamino}methyl)phenyl]thio)-5-iodophenylamine) is a novel radiotracer that targets serotonin transporters. We assessed the toxicity of [(123)I]ADAM (18.5 MBq) administered in early- and late-phases (8 and 14 day postfertilization, respectively) of pregnancy. The mortality, clinical status, and gross necropsy were measured in pregnant rats, and the fertility index was measured in rat offspring (weight, clinical observations). We found no dosing-related clinical signs. In conclusion, [(123)I]ADAM was not toxic in an animal pregnancy model.

HGFK1 inhibits bone metastasis in breast cancer through the TAK1/p38 MAPK signaling pathway

Breast cancer metastasis to bone represents a devastating complication of advanced breast cancer, frequently resulting in significant increases in morbidity and mortality. An understanding of the mechanisms that govern breast cancer metastasis at the molecular level should lead to more effective therapies. Recently, the kringle 1 domain of human hepatocyte growth factor (HGFK1) was identified as a candidate metastasis suppressor gene. Here, we investigated whether HGFK1 is a key regulator of breast cancer bone metastasis. Of the 193 human breast carcinoma tissue samples examined, HGFK1 expression was relative higher in 82 (42.4%) by western blot and in 84 (43.5%) by quantitative real-time PCR. The higher expression of HGFK1 was significantly associated with a better prognostic value (P<0.001) and inversely correlated with bone metastasis (P=0.003). The efficacy of adeno-associated virus carrying HGFK1 (AAV-HGFK1) in osteolytic bone metastasis was then evaluated using an in vivo bone metastasis model. AAV-HGFK1 significantly inhibited osteolytic bone metastasis and prolonged the survival of mice in this model (P<0.01). In vitro, HGFK1 expression resulted in significant anti-invasion effects, enhanced the phosphorylation of TAK1 (transforming growth factor-β-activated kinase 1), p38 MAPK (mitogen-activated protein kinase) and MAPKAPK2 (MAPK-activated protein kinase 2) and decreased the expression of receptor activator of nuclear factor-κB (RANK), which was abrogated by the p38 MAPK inhibitor SB203580. This study shows for the first time that HGFK1 significantly inhibits the metastasis of breast cancer to bone by activating the TAK1/p38 MAPK signaling pathway and inhibiting RANK expression. Thus, AAV-HGFK1 treatment represents a potential therapy for bone metastasis in breast cancer.

The Use of Vestibular Test Battery to Identify the Stages of Delayed Endolymphatic Hydrops

Objective

Patients with delayed endolymphatic hydrops (DEH) underwent a vestibular test battery to evaluate the residual function, assess their clinical stage, and predict outcome.

Study Design

Case series with chart review.

Setting

University hospital.

Subjects and Methods

Twenty patients with DEH, 15 with ipsilateral type and 5 with contralateral type, were enrolled. All patients underwent audiometry and caloric, ocular vestibular-evoked myogenic potential (oVEMP), and cervical VEMP (cVEMP) tests. The DEH staging was based on vestibular test results. Stage 0 indicates that all 3 vestibular tests are normal, while stages I through III indicate abnormal results in tests 1 through 3, respectively.

Results

Of the 20 DEH patients, 2 patients were stage 0, 12 patients were stage I, 4 patients were stage II, and 2 patients were stage III. The median frequency of vertigo in patients with stages II and III was 4 episodes monthly, significantly less than 15 episodes monthly in those with stages 0 and I. Ipsilateral and contralateral types did not differ significantly in the stage distribution. The percentages of abnormal cVEMP, oVEMP, and caloric test results for patients with ipsilateral type were 80%, 33%, and 13%, not significantly different from those for contralateral type.

Conclusions

As a vertiginous attack may subside spontaneously for patients with long-term DEH, one must identify its clinical stage based on cVEMP, oVEMP, and caloric test results. In early stage DEH, most vestibular function remained relatively intact, leading to repeated vertiginous attacks. Conversely, subsidence of vertiginous episode can be anticipated in patients with late stage DEH.

Kinetics and mechanisms for the adsorption, dissociation, and diffusion of hydrogen in Ni and Ni/YSZ slabs: a DFT study

The adsorption, dissociation, and diffusion of hydrogen in Ni(100) and Ni(100)/YSZ(100) slabs with two different interfaces (Ni/cation and Ni/O interface) have been studied by the density functional theory (DFT) with the Perdew-Wang functional. The H(2) molecule is found to preferentially absorb on a Top (T) site with side-on configuration on the Ni(100) surface, while the H-atom is strongly bound at a fcc Hollow (H) site. The barrier for the H(2) dissociation on both surfaces is calculated to be only ~0.1 eV. The potential energy pathways of H diffusion on pure Ni and Ni/YSZ with the two different interfaces are studied. Our calculated results show that the H-atom diffusion occurs via surface path rather than the bulk path. For the bulk path in Ni/YSZ, H-atom migration can occur more readily at the Ni/cation interface compared to the Ni/O interface. The existence of vacancy in the interface region is found to improve the mobility of H-atoms at the interface of Ni/YSZ slab. The rate constants for hydrogen dissociation and diffusion in pure Ni and Ni/YSZ are predicted.

Magnetic field enhanced resonant tunneling in a silicon nanowire single-electron-transistor

We report fabrication, measurement and simulation of silicon single-electron-transistors made on silicon-on-insulator wafers. At T-2 K, these devices showed clear Coulomb blockade structures. An external perpendicular magnetic field was found to enhance the resonant tunneling peak and was used to predict the presence of two laterally coupled quantum dots in the narrow constriction between the source-drain electrodes. The proposed model and measured experimental data were consistently explained using numerical simulations.

A grounded theory longitudinal study of carers’ experiences of caring for people with dementia

Introduction

Increasingly the provision of care for older people with dementia has shifted from institutions to the community. This has resulted in an increase in burden and a reduction in autonomy for those who care for these individuals.

Aims

This study sought to identify, describe and explore the changes in the carers’ experiences of looking after a relative living with dementia, and the effects of caring on the carers’ autonomy and health over time.

Research Methods

A longitudinal, grounded theory approach in three phases was used. In-depth interviews were conducted with six spouses at the beginning, at six months and at eighteen months. A constant comparative analysis of taped and transcribed interviews was used.

Findings

Four categories emerged: My Life Changed, Commitment, Responsibility and Duty, and Support. The core category My Life Changed was identified as representing the beginning of the caregiving journey; and the learning from experience that occurred as a consequence of that journey, offering a new perspective on the experience of carers. Commitment refers to a deepened and sustained element; Responsibility and Duty increases over time and finally Support refers to the fluctuating nature of help provided by formal and informal sources. All participants experienced changes in the caregiving journey; the degree and nature of necessary adaptations varied.

Conclusions

A Theory of Caring emerged, but what changes were experienced did not appear to conform to any fixed pattern. All carers learned by experience to manage their situations. For all carers their autonomy and health was challenged.

Computational investigation of O2 reduction and diffusion on 25% Sr-doped LaMnO3 cathodes in solid oxide fuel cells

The oxygen reduction reaction (ORR) and diffusion mechanisms on 25% Sr-doped LaMnO(3) (LSM) cathode materials as well as their kinetic behavior have been studied by using spin-polarized density functional theory (DFT) calculations. Bader charge and frequency analyses were carried out to identify the oxidation state of adsorbed oxygen species. DFT and molecular dynamics (MD) results show that the fast O(2) adsorption/reduction process via superoxide and peroxide intermediates is energetically favorable on the Mn site rather than on the Sr site. Furthermore, the higher adsorption energies on the Mn site of the (110) surface compared to those on the (100) surface imply that the former is more efficient for O(2) reduction. Significantly, we predict that oxygen vacancies enhance O(2) reduction kinetics and that the O-ion migration through the bulk is dominant over that on the surface of the LSM cathode.