Microarray profiling identifies hsa_circ_0082003 as a novel tumor promoter for papillary thyroid carcinoma.

BACKGROUND: Circular RNAs (circRNAs) are non-coding RNAs that have essential regulatory roles in the development of various tumors. This study explored whether circRNAs are involved in the progression of papillary thyroid carcinoma (PTC). METHODS: Differentially expressed circRNAs (DECs) in four pairs of PTC and matched normal thyroid tissues were screened using a circRNA microarray. The potential functions of dysregulated circRNAs were predicted by bioinformatic analyses. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to determine hsa_circ_0082003 expression in 80 pairs of PTC and matched normal thyroid tissues. Cell counting kit-8, colony formation, wound healing, and Transwell assays were performed to evaluate the biological functions of hsa_circ_0082003 in PTC cells. The role of hsa_circ_0082003 in PTC tumorigenesis in vivo was validated in nude mice. RESULTS: In total, 3150 DECs (2317 upregulated and 833 downregulated) were identified. Pathway enrichment analyses indicated that the dysregulated circRNAs may play roles in PTC development. RT-qPCR validation demonstrated that hsa_circ_0082003 expression was significantly increased in PTC tissues and correlated with poor clinicopathological parameters. Receiver operating characteristic curve analysis showed that hsa_circ_0082003 had good performance for diagnosing PTC and judging whether it was accompanied by lymph node metastasis. Knockdown of hsa_circ_0082003 inhibited PTC cell proliferation, migration, and invasion. Tumor formation assays in vivo showed that downregulation of hsa_circ_0082003 significantly suppressed the growth of PTC. CONCLUSION: Hsa_circ_0082003 may serve as a novel diagnostic biomarker and potential therapeutic target for PTC.

Nomograms based on sonographic and clinicopathological characteristics to predict lateral lymph node metastasis in classic papillary thyroid carcinoma.

BACKGROUND: Lateral lymph node metastasis (LLNM) has been considered a risk factor of recurrence in papillary thyroid cancer (PTC). Preoperative detecting LLNM accurately is difficult. Solitary lateral lymph node metastasis is a special type of LLNM. We aimed to develop nomograms for predicting LLNM and multiple lateral lymph node metastasis (MLLNM). METHODS: We retrospectively retrieved 528 classic PTC patients that underwent surgery between March 2019 and May 2020. Sonographic and clinicopathological features were collected. Risk factors of LLNM and MLLNM were determined by univariate and multivariate analysis. Nomograms for predicting LLNM and MLLNM were developed. RESULTS: LLNM was independently associated with tumor size, the number of foci, location, margin, central lymph node metastasis, and lymph node ratio. Independent predictors of MLLNM were age, margin, and the number of metastatic lymph nodes in central compartment. By using above variables, we constructed nomograms for predicting LLNM and MLLNM, with area under curves of 0.864 and 0.748, respectively. CONCLUSION: Through these accurate and easy-to-use nomograms, we can detect the risk of residual LLNM postoperatively for classic PTC patients who did not receive lateral neck dissection and provide an individualized plan for postoperative management of classic PTC patients.

Management of cN0 papillary thyroid microcarcinoma patients according to risk-scoring model for central lymph node metastasis and predictors of recurrence.

BACKGROUND: The role of routine prophylactic central neck dissection (pCND) in clinically lymph node-negative (cN0) papillary thyroid microcarcinoma (PTMC) patients remains controversial. This retrospective study aimed to identify the clinical and pathologic factors of central lymph node metastasis (CLNM) and recurrence in PTMC patients. METHODS: A total of 371 cN0 PTMC patients from two hospitals were retrospectively analyzed. All patients underwent thyroidectomy plus pCND between January 2010 and January 2018. Clinicopathological features were collected, univariate and multivariate analyses were performed to determine the risk factors of CLNM. A scoring model was constructed on the basis of the results of independent risk factors of CLNM. The Cox proportional hazards model was used to analyze the risk factors of recurrence. RESULTS: CLNM occurred in 123 (33.2%) patients. Multivariate analysis showed male, tumor size > 0.75 cm, multifocality, extrathyroidal extension (ETE) and tumor in the middle/lower pole were independent risk predictors of CLNM (P < 0.05). A seven-point risk-scoring model was established to predict the stratified CLNM in cN0 PTMC patients. Multivariate Cox regression model showed ETE, vascular invasion and CLNM were independent risk predictors of recurrence (P < 0.05). CONCLUSION: Our study suggested that routine pCND should be performed for cN0 PTMC patients with score ≥ 3 according to the risk-scoring model. Moreover, patients with risk factors of recurrence should consider more complete treatment and more frequent follow-up.

Total tumor diameter: the neglected value in papillary thyroid microcarcinoma.

BACKGROUND: Tumor multifocality is not uncommon in papillary thyroid carcinoma (PTC), especially in micro-PTC. However, assessing the size of the largest tumor may underestimate effect of additional foci. We aimed to investigate the effect of total tumor diameter (TTD) on clinicopathological features of micro-PTC. METHODS: Data from 442 patients who underwent thyroidectomy with cervical lymph node dissection for PTC were retrospectively analyzed. Patients were classified into subgroups according to multifocality and TTD. The relationships of clinicopathological features among these groups were analyzed. RESULTS: Multifocality was observed in 119 patients (26.9%). TTD > 1 cm and presence of extrathyroidal extension (ETE) were significantly higher in multifocal tumors compared to unifocal tumor (P < 0.001, P = 0.016, respectively). When comparing multifocal micro-PTC with TTD > 1 cm to those with unifocal micro-PTC or multifocal micro-PTC with TTD ≤ 1 cm, the proportions of cases with ETE, central lymph node metastasis (CLNM), and lateral lymph node metastasis (LLNM) were significantly higher (all P < 0.05). There was no significant difference in terms of these parameters between multifocal micro-PTC with TTD > 1 cm and macro-PTC or multifocal macro-PTC. The risk of CLNM was 2.056 (P = 0.044) times higher in multifocal micro-PTC with TTD > 1 cm than in unifocal micro-PTC. CONCLUSION: For multifocal micro-PTC, TTD can better assess the aggressiveness of the tumor. Multifocal micro-PTC with TTD > 1 cm was more aggressive than unifocal micro-PTC or multifocal micro-PTC with TTD ≤ 1 cm.

[Newborn screening program and blood amino acid profiling in early neonates with citrin deficiency].

Objective: To investigate the profiles of blood amino acid and acylcarnitine in early neonates with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and the sensitivity of newborn screening, and to explore potential biochemical metabolic markers for newborn screening program. Methods: Amino acid and acylcarnitine profiles in dried blood spots of newborn screening program were analyzed by tandem mass spectrometry (MS/MS). A total of 158 651 neonates born in Guangzhou from January 1, 2015 to June 30, 2019 were enrolled in this newborn screening program, and additionally 55 patients with NICCD confirmed by SLC25A13 gene analysis in Guangzhou Women and Children Medical Center were included in this study. NICCD screen-positive was defined as the cutoff value of citrulline (Cit) ≥ 30 µmol/L. The values of blood sampling time of the true positive group and those of the false negative group were compared by t-test. The levels of amino acid and acylcarnitine among different groups, including true positive group (Cit≥30 µmol/L), false negative group (Cit 21-<30 µmol/L and Cit<21 µmol/L) and the normal control group, were analyzed by F test, respectively. Results: Among 158 651 neonates, 39 neonates were positive for NICCD screening. Three of them were confirmed NICCD and 4 cases were found to be false negatives. The positive predictive value was 7.7% and the sensitivity was about 43.0%. Among 55 patients with NICCD, 18 cases (18/55, 32.7%) were true positives and 37 cases (37/55, 67.3%) were false negatives based on the cutoff value of citrulline in the dried blood spots for newborn screening. The blood sampling time was significantly different between true positive group and false negative group ((4.28±1.6) vs. (2.98±0.74) d, t=4.06, P<0.01). The increased levels of tyrosine((176.0±98.4) µmol/L), methionine ((37.0±26.9) µmol/L) and phenylalanine ((133.0±80.9)µmol/L) in Cit≥30 µmol/L group (n=18) were significantly different as compared with those in the other three groups, respectively (F=117.0, 58.5, 135.0, P<0.01). The levels of arginine ( (10.0±9.2) , (11.0±9.3) , (9.0±17.8) µmol/L), valine ( (119.0±29.8) , (107.6±14.1) , (102±68) µmol/L) and leucine ( (167.0±37.1) , (161.0±37.7) , (163.5±180.6) µmol/L) were not statistically significant among groups of Cit≥30 µmol/L(n=18), Cit21-<30 µmol/L(n=7) and Cit<21µmol/L(n=30,P>0.05), but they were significantly higher than those of the normal control group ((4±3), (78±21), (114.0±31.5) µmol/L, n=1 000), respectively(F=30.1, 23.0, 29.8, P<0.01). Alanine (Ala) ( (150±50) , (156.0±30.2), (168±105), (152±52) µmol/L) levels showed no significant difference (F=0.86, P>0.05) but the ratios of Ala/Cit (1.52±1.44, 6.82±1.56, 12.06±7.71, 19.42±6.27) decreased significantly among the four groups (F=69.0, P<0.05). The acylcarnitine levels showed no statistically significant results among the different groups (P>0.05). With Cit≥30 µmol/L and Ala/Cit<7.5 as cutoff values, the number of screen-positive cases reduced from 39 to 22 cases with no additional false negative case. With Cit≥21 µmol/L and Ala/Cit<7.5 as cutoff values the number of screen-positive cases increased to 117 cases with 1 additional true positive. Conclusions: The profiles of blood amino acid in early neonates with NICCD present the increased levels of multiple amino acids including citrulline, tyrosine, methionine and phenylalanine, and decreased ratio of Ala/Cit. Taking citrulline and ratio of Ala/Cit as screening markers can improve the positive predictive value appropriately. The limited sensitivity of NICCD newborn screening may be related to early blood sampling time.

Predictive factors for central lymph node and lateral cervical lymph node metastases in papillary thyroid carcinoma.

BACKGROUND: Central lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC) is common. But the association between primary tumor characteristics and specific features of metastatic lymph nodes in PTC has not been fully identified. Determining risk factors for LNM may help surgeons determine rational extent of lymph node dissection. METHODS: Data from 432 patients who underwent thyroidectomy with cervical lymph node dissection for PTC were retrospectively analyzed. The relationships between LNM to central compartment or lateral compartment and clinicopathologic factors were analyzed. Cox regression model was used to determine the risk factors for recurrence-free survival (RFS). RESULTS: Central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM) were found in 216 (50.0%) and 65 (15.0%) patients, respectively. In the multivariate analysis for CLNM, patients < 45 years of age (OR 2.037, 95% CI 1.388-2.988, P < 0.001), extrathyroidal invasion (OR: 2.144, 95% CI 0.824-5.457, P = 0.011), vascular invasion (OR 13.817, 95% CI 1.694-112.693, P = 0.014), LLNM (OR 2.851, 95% CI 1.196-6.797, P = 0.014) and TNM Stage III-IV (OR 465.307, 95% CI 113.903-1900.826, P < 0.001) were independent predictors for high prevalence of CLNM. In the multivariate analysis for LLNM, tumor size more than 1cm (OR 3.474, 95% CI 1.728-6.985, P < 0.001) and CLNM (OR 5.532, 95% CI 2.679-11.425, P < 0.001) were independent predictors for high prevalence of LLNM. Moreover, tumor with T3-T4 stage, extrathyroidal invasion and CLNM were the significant factors related to the RFS. CONCLUSION: For patients with pre-operative risk factors of LNM, an accurate preoperative evaluation of central compartment or lateral compartment is needed to find suspicious lymph nodes. And prophylactic lymph node dissection should be performed in patients with high risk of CLNM. Moreover, we suggest performing close follow-up for patients with high risk of RFS.

Non-monotonic changes in critical solidification rates for stability of liquid-solid interfaces with static magnetic fields.

We report the magnetic field dependence of the critical solidification rate for the stability of liquid-solid interfaces. For a certain temperature gradient, the critical solidification rate first increases, then decreases, and subsequently increases with increasing magnetic field. The effect of the magnetic field on the critical solidification rate is more pronounced at low than at high temperature gradients. The numerical simulations show that the magnetic-field dependent changes of convection velocity and contour at the interface agree with the experimental results. The convection velocity first increases, then decreases, and finally increases again with increasing the magnetic field intensity. The variation of the convection contour at the interface first decreases, then increases slightly, and finally increases remarkably with increasing the magnetic field intensity. Thermoelectromagnetic convection (TEMC) plays the role of micro-stirring the melt and is responsible for the increase of interface stability within the initially increasing range of magnetic field intensity. The weak and significant extents of the magneto-hydrodynamic damping (MHD)-dependent solute build-up at the interface front result, respectively, in the gradual decrease and increase of interfacial stability with increasing the magnetic field intensity. The variation of the liquid-side concentration at the liquid-solid interface with the magnetic field supports the proposed mechanism.

A microstructural examination of apatite induced by Bioglass in vitro.

Bioglass, a clinically used bone graft material, has been tested in vitro in a simulated body fluid (SBF) up to four weeks. Apatite crystals were not only found to form on its surface but also in the reaction solutions. The apatite crystals have been examined by high-resolution transmission electron microscopy (TEM). The crystals formed in the solutions appear identical in morphology and structure with those formed on the Bioglass surface. It may be that the soluble Si in the solution serves as the nucleating site for the apatite crystal or that apatite nuclei are released from the Bioglass surface to the solution resulting in crystal growth.

The observation of some biological characteristics of transformed cells induced by MNNG in vitro.

The early passage diploid Syrian hamster embryo (SHE) cells were treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The treated cells proliferated rapidly; the doubling times shortened; colonies appeared in solid agar medium and transformed foci formed in tissue culture. All of these phenomena suggest that malignant transformation of SHE cell has occurred. Faster cell division rate and multipolar mitosis were demonstrated by time-lapse cinemicrography and scanning electron microscopy. Multipolar mitosis can occur in two forms: direct division and indirect division. The transformed cells were more abundant in microvilli, the number of which increased in accordance with the degree of malignancy. In comparison with the controls, the transformed cells expressed a greater tritiated thymidine incorporation, greater DNA contents and more chromosomes, but no difference in nuclear area. The determination of amino acid changes in media due to the growth of transformed cells showed that the decrease in arginine and increase in ornithine are significant. The results of allogenic animal inoculation suggest that the transformed cells can be characterized into several different stages in the process of transformation.