Restratification of Patients with Intermediate-Risk Papillary Thyroid Carcinoma.

BACKGROUND: Long-term management and follow-up strategies in patients with intermediate-risk papillary thyroid carcinoma (PTC) according to the American Thyroid Association (ATA) are still controversial due to the paucity of data on unique risk factors or a risk stratification system predictive of long-term outcomes. PATIENTS AND METHODS: This study included 649 patients with PTC who underwent an initial surgical treatment. Retrospectively enrolled patients were categorized according to the ATA risk stratification system. Intermediate-risk patients were further categorized into subgroups by the number of ATA intermediate risk factors. The recurrence-free survival (RFS) rates of these subgroups were compared with those of low- and high-risk patient groups. Additionally, the patients were classified according to their response to the initial therapy using the dynamic risk stratification (DRS) system, and the percentages of patients in each category were compared among the subgroups. RESULTS: The median follow-up period was 102 months. Structural recurrence occurred in 9.2% of all enrolled patients (60/649) and in 13.0% of intermediate-risk patients (40/308). Patients with two or more current intermediate risk factors had a poorer RFS than patients with only one risk factor (p < 0.001) and showed a comparable RFS to high-risk patients (p > 0.050). The percentages of patients with an excellent response category for DRS significantly decreased with an increase in the number of intermediate risk factors. CONCLUSION: Subclassification according to the number of intermediate risk factors may be useful to better predict the RFS and the response to initial therapy in patients with intermediate-risk PTC.

Comparison of the abilities of staging and risk stratification systems to predict the long-term structural recurrence in patients with differentiated thyroid carcinoma after total thyroidectomy and radioactive iodine remnant ablation.

BACKGROUND: In patients with differentiated thyroid carcinoma (DTC), various staging and risk stratification systems have been applied to estimate long-term recurrence, which is a major issue during the postoperative follow-up period. However, the efficacy of these systems remains unclear in this context. METHODS: The present historical cohort study included 510 patients with DTC who underwent a total thyroidectomy followed by radioactive iodine (RAI) remnant ablation. Enrolled patients were categorized according to the 8th edition of American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) Tumor Node Metastasis (TNM) staging system, the 2015 American Thyroid Association (ATA) initial risk stratification system, and the dynamic risk stratification (DRS) system. The ability of each system to predict long-term structural recurrence was compared using proportion of variance explained (PVE) by logistic regression models. RESULTS: The median follow-up period was 108 months. Structural recurrence occurred in 7.6% of the patients (n=39/510). Disease-free survival (DFS) curves of the patients within each category in the TNM staging system, the ATA initial risk stratification system, and the DRS system were significantly different (P<0.001). The PVE of the DRS system (20.7%) was higher than those of the TNM staging system and the ATA initial risk estimates. CONCLUSIONS: The DRS system may effectively predict long-term structural recurrence and guide long-term management and follow-up strategies in patients with DTC undergoing total thyroidectomy and RAI remnant ablation.

Optimal Timing of Initiating Dynamic Risk Stratification During the Early Postoperative Period in Patients with Differentiated Thyroid Carcinoma After Thyroidectomy and Radioactive Iodine Remnant Ablation.

BACKGROUND: This study investigated the optimal timing to initiate assessment of the response to initial therapy during the early postoperative period in patients with differentiated thyroid carcinoma (DTC) using dynamic risk stratification (DRS). METHODS: This historical cohort study included 510 patients with DTC who underwent a total thyroidectomy followed by radioactive iodine (RAI) remnant ablation. DRS for these patients was categorized into subgroups according to the time into the follow-up period at which the response to initial therapy was assessed. The ability of each DRS subgroup to predict the long-term structural recurrence of cancer was compared using the proportion of variance explained (PVE) from logistic regression models. RESULTS: The median follow-up period was 108 months. Structural recurrence occurred in 7.6% of patients (n = 39/510). The PVE for long-term structural recurrence was higher among DRS subgroups (28.8-34.19%) compared with the American Joint Committee on Cancer/Union for International Cancer Control tumor-node-metastasis staging system (both the 7th and 8th editions; 4.01% and 6.13%, respectively) and the American Thyroid Association initial risk estimate (4.59%). Among the DRS subgroups, DRS assessed between 2 and 3 years after the initial surgery was associated with the highest PVE (34.19%). CONCLUSIONS: The first assessment of DRS optimally predicts long-term structural recurrence in patients with DTC who underwent a total thyroidectomy and subsequent RAI remnant ablation at that 2- to 3-year postoperative period.

Position and Velocity Estimation for Two-Inertia System with Nonlinear Stiffness Based on Acceleration Sensor.

In this paper, we consider the state estimation problem for flexible joint manipulators that involve nonlinear characteristics in their stiffness. The two key ideas of our design are that (a) an accelerometer is used in order that the estimation error dynamics do not depend on nonlinearities at the link part of the manipulators and (b) the model of the nonlinear stiffness is indeed a Lipschitz function. Based on the measured acceleration, we propose a nonlinear observer under the Lipschitz condition of the nonlinear stiffness. In addition, in order to effectively compensate for the estimation error, the gain of the proposed observer is chosen from the ARE (algebraic Riccati equations) which depend on the Lipschitz constant. Comparative experimental results verify the effectiveness of the proposed method.

Biochemical characteristization of propionyl-coenzyme a carboxylase complex of Streptomyces toxytricini.

Acyl-CoA carboxylases (ACC) are involved in important primary or secondary metabolic pathways such as fatty acid and/or polyketides synthesis. In the 62 kb fragment of pccB gene locus of Streptomyces toxytricini producing a pancreatic inhibitor lipstatin, 3 distinct subunit genes of presumable propionyl-CoA carboxylase (PCCase) complex, assumed to be one of ACC responsible for the secondary metabolism, were identified along with gene for a biotin protein ligase (Bpl). The subunits of PCCase complex were a subunit (AccA3), P subunit (PccB), and auxiliary ɛ subunit (PccE). In order to disclose the involvement of the PCCase complex in secondary metabolism, some biochemical characteristics of each subunit as well as their complex were examined. In the test of substrate specificity of the PCCase complex, it was confirmed that this complex showed much higher conversion of propionyl-CoA rather than acetyl-CoA. It implies the enzyme complex could play a main role in the production of methylmalonyl-CoA from propionyl-CoA, which is a precursor of secondary polyketide biosynthesis.