Enhancing the sequence coverage of nanodiamond-extracted early secretory proteins from the Mycobacterium tuberculosis complex.

The unambiguous identification of protein species requires high sequence coverage. In this study, we successfully improved the sequence coverage of early secretory 10 kDa cell filtrate protein (CFP-10) and 6 kDa early secretory antigenic target (ESAT-6) proteins from the Mycobacterium tuberculosis complex (MTC) in broth culture media with the use of the 4-chloro-α-cyanocinnamic acid (Cl-CCA) matrix. Conventional matrices, α-cyano-hydroxy-cinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB), were also used for comparison. After nanodiamond (ND) extraction, the sequence coverage of the CFP-10 protein was 87% when CHCA and DHB matrices were used, and the ESAT-6 protein was not detected. On the other hand, the sequence coverage for ND-extracted CFP-10 and ESAT-6 could reach 94% and 100%, respectively, when the Cl-CCA matrix was used and with the removal of interference from bovine serum albumin (BSA) protein and α-crystallin (ACR) protein. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was also adopted to analyze the protein mass spectra. A total of 6 prominent ion signals were observed, including ESAT-6 protein peaks at mass-to-charge ratios (m/z) of ∼7931, ∼7974, ∼9768, and ∼9813 and CFP-10 protein peaks at m/z of ∼10 100 and ∼10 660. The ESAT-6 ion signals were always detected concurrently with CFP-10 ion signals, but CFP-10 ion signals could be detected alone without the ESAT-6 ion signals. Furthermore, the newly found ESAT-6 peaks were also confirmed using a Mag-Beads-Protein G kit with an ESAT-6 antibody to capture the ESAT-6 protein, which was also consistent with the sequence coverage analysis.

Association between provider volume and healthcare expenditures of patients with oral cancer in Taiwan: a population-based study.

BACKGROUND: Oral cancer requires considerable utilization of healthcare services. Wide resection of the tumor and reconstruction with free flap are widely used. Due to high recurrence rate, close follow-up is mandatory. This study was conducted to explore the relationship between the healthcare expenditure of oncological surgery and one-year follow up and provider volume. METHODS: From the National Health Insurance Research Database published by the Taiwanese National Health Research Institute, the authors selected a total of 1300 oral cancer patients who underwent tumor resection and free flap reconstruction in 2008. Hierarchical linear regression analysis was subsequently performed to explore the relationship between provider volume and expenditures of oncological surgery and one-year follow-up period. Emergency department (ED) visits and 30-day readmission rates were also analyzed. RESULTS: The mean expenditure for oncological surgery was $11080±4645 (all costs are given in U.S. dollars) and $10129±9248 for one-year follow up. For oncological surgery expenditure, oral cancer patients treated by low-volume surgeons had an additional $845 than those in high-volume surgeons in mixed model. For one-year follow-up expenditure, patients in low-volume hospitals had an additional $3439 than those in high-volume hospitals; patient in low-volume surgeons and medium-volume surgeons incurred an additional expenditure of $2065 and $1811 than those in high-volume surgeons. Oral cancer patients treated in low-volume hospitals incurred higher risk of 30-day readmission rate (odds ratio, 6.6; 95% confidence interval, 1.6-27). CONCLUSIONS: After adjusting for physician, hospital, and patient characteristics, low-volume provider performing wide excision with reconstructive surgery in oral cancer patients incurred significantly higher expenditure for oncological surgery and one-year healthcare per patient than did others with higher volumes. Treatment strategies adapted by high-volume providers should be further analyzed.

Increased risk of stroke in young head and neck cancer patients treated with radiotherapy or chemotherapy.

BACKGROUND: Chemo-radiotherapy-induced carotid stenosis and cerebrovascular events in head and neck cancer patients can cause severe disability and death. We aimed to estimate the risk of stroke in such patients over a six-year follow-up period. PATIENTS AND METHODS: The study cohort consisted of head and neck cancer patients (n=10,172). Cox proportional hazard model was used to compare the stroke-free survival rate between the patients treated with radiotherapy or chemotherapy, surgery alone, and surgery with adjuvant therapy after adjusting for possible confounding factors. RESULTS: At the end of follow-up, 384 patients had strokes: 126 (4.3%) from the surgery alone group, 167 (3.8%) from the radiotherapy or chemotherapy group, and 91 (3.2%) from the surgery with adjuvant therapy (P=0.222). Head and neck cancer patients aged less than 55 years treated with radiotherapy or chemotherapy conferred a 1.8-fold higher risk for stroke (95% CI, 1.22-2.56; P=0.003) after adjusting for patient characteristics, co-morbidities, geographic region, urbanization level, and socio-economic status. There was no statistical difference in stroke risk between different treatment modalities in head and neck cancer patients aged 55 years and more. CONCLUSIONS: Young head and neck cancer patients treated with radiotherapy or chemotherapy have higher risks for stroke. Different treatment strategies should be considered in such patients.

Primary tumor volume calculation as a predictive factor of prognosis in nasopharyngeal carcinoma.

CONCLUSIONS: Primary tumor volume (PTV) has a close relationship with survival rates of patients with nasopharyngeal carcinoma (NPC) who were treated with concurrent chemoradiotherapy (CCRT) or radiotherapy. Besides the current AJCC staging system, measurement of PTV may be needed to predict prognosis of NPC and adjust treatment strategy. OBJECTIVES: We conducted a retrospective study to elucidate the effect of PTV on treatment outcomes in patients with NPC who were treated with CCRT or radiotherapy. PATIENTS AND METHODS: A total of 66 patients with newly diagnosed NPC were enrolled in this study. Computed tomography (CT)-derived or magnetic resonance imaging (MRI)-derived PTV was calculated. The correlation between AJCC disease stage, PTV, and disease-specific survival was analyzed. Correlations between different prognostic factors were assessed using a Cox regression model. RESULTS: The median PTV for the whole series was 12.01 ml (range 1.25-166.58 ml). The median PTV was 3.45 ml in T1 disease, 7.96 ml in T2 disease, 17.95 ml in T3 disease, and 64.73 ml in T4 disease. Disease stage and T stage carried no prognostic significance (p=0.25 and p =0.30, respectively). Four categories of PTV (<12.5 ml, 12.5-25 ml, 25-50 ml and >50 ml) had prognostic significance (p=0.02). Survival analysis demonstrated a significant difference in overall survival with larger tumor volume (risk ratio 5.447; p=0.044).