Precise magnetic resonance imaging-guided sonodynamic therapy for drug-resistant bacterial deep infection.

The precise treatment of drug-resistant deep bacterial infections remains a huge challenge in clinic. Herein, a polymer-peptide-porphyrin conjugate (PPPC), which can be real-time monitored in infectious site, is developed for accurate and deep sonodynamic therapy (SDT) based on "in vivo self-assembly" strategy. The PPPC contains four moieties, i.e., a hyperbranched polymer backbone, a self-assembled peptide linked with an enzyme-cleavable peptide-poly (ethylene glycol) terminal, a bacterial targeting peptide, and a porphyrin sonosensitizer (MnTCPP) segment. Once PPPC nanoparticles reach the infectious area, the protecting PEG layers are removed due to the over-expressed gelatinase, leading to the secondary assembly into large nanoaggregates and resultant enhanced accumulation of sonosensitizer. The nanoaggregates exhibit enhanced interaction with bacterial membrane and decrease the minimum inhibitory concentration (MIC) significantly. Meanwhile, compared with free MnTCPP, the concentration of which can not be accurately quantified, the accumulation amount of MnTCPP in PPPCs at infectious site can be in situ monitored by magnetic resonance imaging (MRI) using T1 combined with T2. When the concentration of PPPC-1 reaches MIC, the drug-resistant bacterial infection area is exposed to ultrasound irradiation, causing the precise and efficient elimination of bacteria. Therefore, the MRI-guided SDT system shows extraordinary tissue penetration depth, drug concentration monitoring, morphology-transformation induced accumulation and improved treatment capacity toward drug-resistant bacteria.

Precise Detection of Gene Mutations in Fine-Needle Aspiration Specimens of the Papillary Thyroid Microcarcinoma Using Next-Generation Sequencing.

PURPOSE: To assess the feasibility of next-generation sequencing (NGS) to detect mutations in BRAF, RAS, TERT promoter, and TP53 genes in ultrasound-guided fine-needle aspiration (FNA) biopsy samples of the papillary thyroid microcarcinoma (PTMC). METHODS: A total of 135 FNA samples out of 135 patients with suspected PTMC were submitted for mutation testing using NGS. NGS was successfully performed in 114 specimens, while the remaining 21 samples were excluded due to insufficient amount/poor quality of DNA and sequencing failure. Of those 114 samples, 72 who were confirmed as having PTMC by postoperative histopathology were enrolled in our study, and the other 42 who had a follow-up with ultrasound were excluded. Mutations of genes including BRAF, NRAS, HRAS, KRAS, TERT promoter, and TP53 were evaluated using NGS. The associations of gene mutations and clinicopathological characteristics of PTMC were analyzed. RESULTS: BRAF mutation was observed in 59 (81.94%) of 72 specimens. This mutation detected in BRAF was p.V600E (c.1799T>A) in exon 15 of all 59 specimens. NRAS mutation was identified in 1 (1.39%) specimen classified as Bethesda III and pathologically confirmed as a follicular variant PTMC. There were no mutations found in TERT promoter or TP53. The tumor with a maximum diameter (D max) larger than 5 mm was shown to be significantly correlated with the BRAF mutation in a multivariate analysis (OR 5.52, 95% CI 1.51-26.42, P = 0.033). But the BRAF mutation was not found to be significantly associated with the gender or age of patients with PTMC (P > 0.05). CONCLUSIONS: This study demonstrated that gene mutations in FNA specimens of PTMC could be successfully analyzed with a higher sensitivity using NGS compared to conventional methods for mutation detection. BRAF mutation of p.V600E was statistically associated with PTMC with a D max larger than 5 mm.

Comprehensive evaluation of medullary thyroid carcinoma before surgery.

BACKGROUND: Medullary thyroid carcinoma (MTC) is a rare disease, but it exhibits more aggressive behaviors. The aim of this study was to improve the diagnostic accuracy of MTC before surgery by analyzing the clinical and ultrasonic data of patients with MTC. METHODS: The study included 71 patients (96 lesions) with histopathologically proven MTC between April 2011 and September 2016 in the Cancer Hospital of Chinese Academy of Medical Sciences and Peking Union Medical College. The clinical characteristics and sonographic findings were retrospectively reviewed and compared between the ultrasonic correct diagnosis group and the ultrasonic misdiagnosis group with the t test or Mann-Whitney U test for quantitative parameters and the χ test or Fisher exact test for qualitative parameters. RESULTS: Compared with the ultrasonic correct diagnosis group, the proportion of the cystic change in the ultrasonic misdiagnosed group was high (25.0% vs. 4.2%), the uncircumscribed margin and irregular shape proportions were low (20.8%, 58.3% vs. 74.7%, 87.3%), calcification was relatively rare (20.8% vs. 56.3%), and rich vascularity was relatively rare (25.0% vs. 78.9%). CONCLUSIONS: In the case of atypical MTC, such as cystic change, circumscribed margin, regular shape, no calcification, no rich vascularity, and normal cervical lymph nodes, MTC is easily misdiagnosed as benign by ultrasound. Therefore, ultrasound, cytology and serum calcitonin should be comprehensively evaluated for a preoperative diagnosis of MTC.

[Effects of Ca2+ on nitric oxide-induced adventitious rooting in cucumber under drought stress]. / å¹²æ—±æ¡ä»¶ä¸‹é’™ç¦»å­å¯¹ä¸€æ°§åŒ–æ°®è¯±å¯¼é»„ç“œä¸å®šæ ¹å‘ç”Ÿçš„å½±å“.

Cucumber (Cucumis sativus L. 'Xinchun 4') was used to explore the relationship between nitric oxide (NO) and calcium (Ca2+) during adventitious rooting under drought stress. Rooting parameters, endogenous Ca2+ fluorescent intensity and the antioxidant enzymes activity (SOD, CAT and APX) in cucumber explants under drought stress were investigated. The results showed that treatment with 200 µmol·L-1 CaCl2 and 0.05% PEG significantly improved the number and length of adventitious root in cucumber explants under drought stress, while the application of Ca2+ chelating agent (EGTA) and channel inhibitor (BAPTA/AM) significantly decreased NO-induced number and length of adventitious root under drought stress. Under drought stress, the fluorescence intensity of Ca2+ in hypocotyls treated with NO and CaCl2 was improved, however, the Ca2+ fluorescence intensity in the hypocotyls treated with NO scavenger (cPTIO) was significantly lower than that in the hypocotyls treated with NO. Under drought stress, the activities of antioxidant enzymes in the cucumber explants were significantly promoted by the treatments with NO and CaCl2, however, Ca2+ chelating agent and channel inhibitor significantly decreased the activity of antioxidant enzymes induced by NO. In conclusion, Ca2+ might be involved in the process of NO-adjusted antioxidant enzymes activity during adventitious rooting under drought stress, which alleviated the negative effects of drought on the adventitious rooting and promoted the formation of adventitious roots.

Factors Influencing the Reliability of Thyroid Fine-Needle Aspiration: Analysis of Thyroid Nodule Size, Guidance Mode for Aspiration and Preparation Method.

OBJECTIVE: We aimed to clarify the influence of ThinPrep preparation, nodule size and guidance mode on the accuracy of thyroid fine-needle aspiration (FNA). METHODS: A total of 1,240 thyroid FNAs were reviewed and 489 cases with histological correlations were enrolled in this study. RESULTS: Of the 489 total cases examined, 101 were processed with both ThinPrep and conventional preparation and 388 entirely with ThinPrep. The overall nondiagnostic rate, sensitivity and accuracy of FNA were 2.0, 91.0 and 89.4%, respectively. The cases with a preoperative ultrasound (n = 469) were grouped according to nodule size. The nondiagnostic rate, sensitivity and accuracy of FNA did not differ significantly with nodule size (p1 = 0.339, p2 = 0.179, p3 = 0.119). A total of 101 resections were performed with palpation-guided FNA and 388 were performed with ultrasound-guided FNA. The nondiagnostic rates, sensitivity and accuracy of FNA were similar in these two groups. CONCLUSIONS: The ThinPrep technique is a valid method for thyroid FNA and is effective for thyroid nodules ≥ 0.5 cm. The reliability of FNA results is not reduced with larger nodules. The use of palpation-guided FNA for palpable solid nodules is also effective.

Hypermethylation of multiple tumor-related genes associated with DNMT3b up-regulation served as a biomarker for early diagnosis of esophageal squamous cell carcinoma.

This study was designed to determine the significance of DNA methyltransferases (DNMTs) in DNA hypermethylation in esophageal squamous cell carcinoma (ESCC) and to identify DNA methylation markers in serum for the early diagnosis of ESCC. A promoter methylation profile of 12 tumor-related genes was assessed using methylation-specific PCR in ESCC and paired non-tumor tissue samples from 47 patients. Expression levels of DNMTs were examined by real-time reverse transcription-PCR and immunohistochemistry. Using MethyLight, the methylation status of 5 genes was analyzed in serum samples from 45 patients and 15 healthy individuals. A total of 46 (97.9%) of 47 ESCC samples showed methylation in at least one of the examined genes, and methylation was most frequent for RAR-ß (46.8%), DAPK (46.8%), p16 (44.7%), and CDH1 (42.6%). Methylation of RASSF1A was significantly correlated with the poorly differentiated tumors and the early pathologic tumor classification (P=0.035 and P=0.046, respectively). Tumoral DNMT3b mRNA up-regulation was significantly correlated with hypermethylation of multiple tumor-related genes (P=0.021). In addition, hypermethylation of cell-free serum DNA was common in ESCC patients, and diagnostic accuracy was increased when methylation of multiple genes (RAR-ß, DAPK, CDH1, p16 and RASSF1A) were analyzed in combination (ROC AUC 0.911, 82.2% sensitivity and 100% specificity). The present study suggests that hypermethylation of multiple tumor-related genes may be involved in the pathogenesis of ESCC and mediated by the increase of DNMT3b expression. A cluster of multiple methylated genes in serum DNA has the potential as a novel biomarker for ESCC diagnosis.

[Sentinel lymph node biopsy in papillary thyroid cancer].

OBJECTIVE: To investigate the reliability and feasibility of sentinel lymph node biopsy (SLNB) of papillary thyroid carcinoma using combination of lymphoscintigraphy, the gamma probe and methylene blue staining techniques. METHODS: Twenty-three consecutive patients with thyroid papillary carcinoma were entered in the study between August 2007 and August 2009. All cases were without clinical evidence of cervical lymph node involvement. The (99)Tc(m)-dextran of 74 MBq (2mCi) was injected intratumorally under ultrasound guidance about 2 h to 5 h prior to surgery. Methylene blue was injected around the tumor during surgery. Preoperative lymphoscintigraphy, intra-operative hand-held gamma probe detecting and methylene blue staining techniques were used to detect the sentinel lymph node (SLN). SLN biopsies were sent to prepare frozen sections and the results were compared with specimen of routine selective neck dissection. RESULTS: The SLNs were identified in all cases with the combination techniques. The SLN identification rates were 87.0% and 100% with methylene blue staining and lymphoscintigraphy plus probe scanning, respectively. Metastases in SLNs were revealed by frozen-section histology in 12 patients. In one case, SLNs frozen-section were negative, but metastasis was detected in routine histology. In other case both SLN and routine histology were negative, but metastasis was detected in non-SLN (level VI) neck dissection. The overall accuracy of the SLN biopsy was 91.3%, positive predictive value 100% and negative predictive value 81.8%. CONCLUSION: The results seem the SLN biopsy technique is a feasible and valuable method for detecting cervical lymph node metastasis and is helpful to decide performing neck dissection in patients with cN0 papillary thyroid carcinoma.

[Sonographically guided percutaneous ethanol injection for therapy of thyroid benign lesion].

OBJECTIVE: To develop the microtrauma therapy for thyroid benign lesion, to evaluate efficacy of sonographically guided percutaneous ethanol injection for therapy of thyroid benign lesion. METHODS: Thirty-two patients with thyroid benign lesion were treated in Cancer Hospital, the patients had thyroid disease with cystic or cystic and solid nodule without heart and lung disease, and no allergy to ethanol, but the most diameter was below 3 cm for the solid disease. These patients were divided into two groups, the first group were 14 patients (from June 2002 to August 2003), the second group was 18 patients (from September 2003 to March 2006). The mean injection times was four (1-6) in the first group, the volume of each ethanol injection made the absolute ethanol well-distributed and kept slight compression intralesional for five minutes for solid disease. Partial liquid was extracted for cystic disease first, and 2-10 ml ethanol was injected into cyst, the internal time between two punctures was one week. Each patient received six times ethanol injection in the second group, ethanol injection was same with the first group. The mean follow-up was 29 (12-57) months. RESULTS: The efficacy rate was 100.0%, the cure rate was 69.2% in the first group. The efficacy rate was 100.0%, the cure rate was 77.8% in the second group. There was no significant difference in the cure rate between the groups (chi2 = 0.0258, P > 0.05). During follow-up, ultrasound revealed no recurrence for the cured patients and no growth for the remnant lesion. Its complications were transient after the procedure, no severe complications occurred. CONCLUSIONS: Sonographically guided percutaneous ethanol injection should be simple, effective, and safe for the thyroid benign lesion, it is easy popularized and may has the effect of cosmetology and microtrauma.

[Sonographic evaluation of the special thyroid carcinoma].

OBJECTIVE: To analyze the cases of thyroid carcinoma with special sonographic features, so as to increase the accuracy of sonographic diagnosis for thyroid carcinoma. METHODS: The sonographic characteristics of 9 patients with special sonographic appearance were analyzed. According to the sonographic features, they were divided into two kinds: 8 cases suffered from thyroid diffuse malignant lesions, and one case showed cystic lesion sticking out of the thyroid. The sonographic appearance of gray scale and color Doppler characteristics of the lesions were recorded. RESULT: In the first kind of lesions, the dimensional ultrasound appearance of gray scale had an apparent feature, however, its color Doppler characteristics had no apparent feature, and all of the 8 cases were diagnosed correctly by ultrasound. In the second kind of lesion, the sonographic appearance of gray scale and color Doppler had no special features, so the case was diagnosed as benign disease wrongly by ultrasound. CONCLUSION: The first kind of lesions has apparent sonographic features, sonographic diagnosis can serve as the first choice. However, the second kind of lesion had no apparent sonographic feature.

[Diagnostic value of ultrasonography in thyroid lesions].

OBJECTIVE: To analyse ultrasonographic mapping of the thyroid lesions, so as to summarize ultrasonographic characteristics, and improve the accuracy rate of preoperative diagnosis for thyroid lesions. METHODS: The clinical data were analyzed for 1700 patients with different thyroid lesions who were treated between January 2002 and December 2005. The appearance of gray scale and colour Doppler sonography for the lesions was prospectively studied, the different blood flow index was determined. All patients underwent surgery and had histopathologic diagnosis at Cancer Hospital, Chinese Academy of Medical Sciences. The criterion of diagnosis for benign lesions were (1) multinodular; (2) the presence of peripheral halo; (3) regular and defined margins, intranodular uniform echogenicity; (4) macrocalcification; (5) the degree of blood flow was I or IV grade, the distribution of blood flow was I type; (6) the blood resistance index was over 0. 6, the blood peak value speed was below 12 cm/s. The criterion of diagnosis for malignant lesions were (1) single nodular; (2) irregular and partly defined margins; (3) intranodular irregular hypoechogenicity; (4) microcalcification; (5) the degree of blood flow was II or III grade, the distribution of blood flow was II type; (6) the presence of metastatic lymph node in region; (7) the blood resistance index was below 0. 6, the blood peak value speed was over 12 cm/s. RESULTS: Of all cases, 1284 cases were benign and 416 cases malignant. The accuracy rate of gray scale sonography for benign and malignant thyroid lesions was respectively 80. 0% and 75.0%. The accuracy rate of ultrasound diagnosis for benign and malignant thyroid lesions was respectively 86.0% and 82.0%, total accuracy rate for thyroid lesion was 85.0%. CONCLUSIONS: Gray scale sonography was very important to distinguishing between benign and malignant lesions of thyroid tumor, the accuracy rate was greatly improved with colour Doppler sonography, but the determination of blood flow index is no help to differentiating between benign and malignant lesions of thyroid tumor. The accurate rate of ultrasound for the diagnosis of thyroid lesions is high, it is the first choice measure in preoperative diagnosis for thyroid lesions.

[Value of high-resolution ultrasonography in differential diagnosis of cervical cystic lesions].

OBJECTIVE: To analyze ultrasonographic features of the different kinds of cervical cystic lesions, and propose differential diagnostic standard for these lesions based on the evidence of high resolution ultrasonography. METHODS: The clinical data of 107 patients with different kinds of cervical cystic lesions were analyzed. The role of gray scale and colour Doppler sonography for such lesions was prospectively studied. RESULTS: The rate of accuracy for benign cervical cystic lesions was 91.1% (92/101), however, it was only 16.7% (1/6) for malignant cervical cystic lesions. CONCLUSION: High-resolution ultrasonography is effective and simple in differential diagnosis of different kinds of cervical cystic lesions, especially for benign ones.