An Improved Staging System of Adenoid Cystic Carcinoma in the External Auditory Canal.

OBJECTIVE: The purpose of this study was to define an improved staging system for adenoid cystic carcinoma (ACC) in the external auditory canal (EAC) based on biological behaviors, image findings, and the prognosis of patients with ACC in the EAC. STUDY DESIGN: A retrospective study. SETTING: A single center data. METHODS: We performed a single-institution retrospective review of 154 patients with ACC in the EAC between January 2004 and September 2021. Risk factors associated with disease-free survival (DFS) and cancer-specific survival (CSS) of ACC in the EAC were identified using univariate and multivariate cox regression analysis. Then an improved staging system was proposed and compared with the Pittsburgh-modified tumor, node, and metastasis (TNM) staging system for statistical differences in DFS and CSS. RESULTS: An improved staging system of ACC in the EAC was defined, in which stage T4 were subclassified into T4a and T4b and were statistically different from the Pittsburgh-modified TNM staging system in DFS and CSS. We also found that the dura mater, facial nerve, sigmoid sinus, deep lobe of parotid gland, and parapharyngeal space involvement were significantly associated with poor prognosis of ACC in the EAC. CONCLUSION: The improved staging system is more accurate in predicting survival prognosis than Pittsburgh-modified TNM staging system for patients with ACC in the EAC, and may provide more efficient guidance of treatment strategy. SUMMARY: The improved staging system of ACC in the EAC is more accurately to predict survival prognosis, and provide guidance of treatment plan than Pittsburgh-modified TNM staging system.

A Novel Classification System and Surgical Strategies of First Branchial Cleft Anomalies.

OBJECTIVE: To define a novel classification of first branchial cleft anomalies (FBCAs) based on the relationship between lesions and the facial nerve in terms of radiographic imaging findings and to introduce the corresponding surgical managements. METHODS: The clinical data were retrospectively reviewed. Novel classification was proposed according to the head-neck MRI findings and surgical records. FBCAs limited in the cartilaginous segment of external auditory canal (EAC) or superficial parotid gland capsule were classified as type A. Lesions close to the FN and(or) involved into the parotid gland with no scar formation and no previous parotidectomy were classified as type B. FBCAs adhered to the FN and(or) invaded the parotid gland with scar formation due to previous surgery were classified as type C. Appropriate surgery approaches was also described, which was correlated with classification. RESULTS: Fifty-one patients were included, and one patient suffered from bilateral lesions. Thirty-one, twelve, and nine lesions were classified as type A, type B, and type C FBCAs, respectively. One type A patient (1.92%) suffered from recurrence during follow-up. Temporary facial palsy (House-Brackmann II) was identified in 2 type C patients (3.85%) after surgery and recovered to normal within 2 months. One type B patient (1.92%) suffered from facial paralysis due to the FN injury and underwent facial nerve graft simultaneously. No patients with type C complained of hearing loss postoperatively. CONCLUSION: This novel classification clearly illustrates definitely relationship between lesion and the facial nerve and appropriate surgical strategies were proposed based on the novel classification. LEVEL OF EVIDENCE: 4 Laryngoscope, 2024.

The Role of Parotid Gland Invasion in Adenoid Cystic Carcinoma of the External Auditory Canal.

OBJECTIVE: This study aimed to investigate the significance of parotid gland invasion in predicting distant metastasis of adenoid cystic carcinoma in the external auditory canal. STUDY DESIGN: Single-institution retrospective cohort study. METHODS: A retrospective review of patients with adenoid cystic carcinoma of the external auditory canal who underwent surgery was performed. Information on patient demographics, parotid gland invasion, tumor stage, perineural invasion, lymphovascular invasion, and follow-up data were collected and analyzed. RESULTS: One hundred twenty-nine patients were identified for review. Parotid gland invasion was noted in 45 patients (34.9%). Parotid gland invasion was significantly associated with tumor stage, perineural invasion, distant metastasis, and postoperative adjuvant therapy. Distant metastasis was noted in 30 patients (23.3%). Multivariate Cox proportional hazards analysis identified parotid gland invasion as an independent risk factor for predicting distant metastasis. The 5-year distant metastasis-free survival rate was 83.6% for patients without parotid gland invasion and 61.8% for patients with parotid gland invasion (p = 0.010). CONCLUSIONS: The parotid gland invasion rate is relatively high in adenoid cystic carcinoma of the external auditory canal and is significantly related to tumor stage. Parotid gland invasion is associated with worse distant metastasis-free survival. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:419-425, 2024.

Comparison of surgical outcomes between early and advanced class of jugular paragangliomas following application of our modified surgical techniques.

To compare the safety and effectiveness of surgical treatment of jugular paragangliomas (JPs) following the application of our modified surgical techniques. Fifty-six patients with JPs were analyzed for tumor classification, surgical outcomes, and intratumor blood vessels. The gross total resection in C1-2 (100%) was significantly greater than that in C3 and D (66.7%). Good postoperative facial nerve (FN) function (House-Brackmann I-II) was achieved in 89.5% C1-2 cases, which was not significantly different from C3 and D (93.3%) (P = 0.694). Preoperative and postoperative lower cranial nerve (LCN) deficits correlated with the Fisch's classification of tumors (P < 0.05), and intraoperative blood loss was greater in advanced tumors (P = 0.050). Further study showed that the cross-sectional area of intratumor blood vessels was positively associated with intraoperative blood loss (P < 0.001). Surgical excision of JPs is a safe and effective strategy, and early surgical treatment is a good option for patients with C1-2 tumors without surgical contraindications.

[The surgical procedures for tension-free anterior rerouting of facial nerve in infratemporal fossa type A approach].

Infratemporal fossa type A approach is the classical approach for resection of tumors in the jugular foramen, and the anterior rerouting of the facial nerve is an important procedure to facilitate tumor exposure. Dysfunction of facial nerve in patients following anterior facial nerve rerouting is great challenge to surgeons and patients. The author made great efforts to modify the surgical management of the facial nerve to improve facial nerve function. After dissection the facial nerve from the fallopian canal and the digastric muscle from the digastric ridge and styloid process, then the digastric muscle and parotid gland were suture with the inferior margin of temporal muscle. A long articulated retractor was placed at an angle of 45° to push the posterior belly of the digastric muscle and the parotid gland anteriorly and superiorly to further minimize the distance from the genicular ganglion to the main trunk of the facial nerve in the parotid gland. All the procedures resulted in tension free anterior rerouting of the facial nerve. Tension-free anterior rerouting of facial nerve not only reduces the tension of the facial nerve, but also preserves the maximal blood supply of the facial nerve, which are beneficial with the recovery of facial nerve function, postoperatively.

Gut Microbiome and Metabolome Changes in Mice With Acute Vestibular Deficit.

Vestibular deficit is a very common disorder in clinical practice and is characterized by vertigo, spontaneous nystagmus, and autonomic nervous symptoms, including nausea, vomiting, and sweating. In addition, the comorbidity of vestibular deficit and anxiety has long been an integral component of the medical literature. Previous studies have suggested that the mechanisms underlying this comorbidity involved overlap of vestibular and cerebellar networks. Emerging evidence has shown that the microbiota-gut-brain axis plays a key role in the regulation of affective disorders. Thus, we hypothesized that the gut microbiota may be involved in the comorbidity of vestibular deficit and anxiety. To verify this, we constructed a unilateral labyrinthectomy mouse model to simulate vestibular deficit. Then, 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC-MS) were used to analyze the microbiome and metabolome of the cecal samples collected from mice in the unilateral labyrinthectomy, sham surgery, and control groups. Notably, unilateral labyrinthectomy shaped the composition of the mouse gut microbiome, resulting in increased abundance of Lachnospiraceae NK4A136 group, Odoribacter and Roseburia and decreased abundance of Prevotella and Parasutterella at the genus level. Tax4Fun functional prediction indicated a decrease in tryptophan metabolism in mice in the unilateral labyrinthectomy group. Moreover, functional correlation of changes in gut microbes and metabolites between different groups showed that the oleamide level was negatively correlated with Odoribacter abundance (r = -0.89, p = 0.0002). The butyric acid level was positively correlated with Parasutterella abundance (r = 0.85, p = 0.0010). The propanoate level was negatively correlated with Prevotella abundance (r = -0.81, p = 0.0020). The 20-HETE level was positively correlated with Parasutterella abundance (r = 0.84, p = 0.0013). The altered microbes and metabolites were closely related to the pathogenesis of affective disorders. Our results not only offer novel insights into the vestibular deficit comorbid with anxiety but also build an important basis for future research on this etiology.

Grading System and Surgical Strategy for Temporal Bone Diffuse-Type Tenosynovial Giant Cell Tumor.

OBJECTIVES: To develop a novel grading system and appropriate surgical approaches for patients with diffuse type tensosynovial giant cell tumor (D-TGCT) of the temporal bone. STUDY DESIGN: Retrospective cohort study. METHODS: We retrospectively reviewed 31 patients with temporal bone D-TGCT between June 2012 and July 2021. All patients underwent comprehensive clinical evaluations, including clinical presentations, hearing threshold, imaging studies, surgical approaches, and prognosis. A grading system was developed based on the tumor location and adjacent neurovascular structures involvement according to imaging and intraoperative findings. RESULTS: In this study, grade II tumors were the most common (13/31), followed by grades I (7/31), III (7/31), and IV (4/31) tumors. Seven grade I patients received the subtemporal middle cranial fossa approach (SMCF) combined with the canal wall up mastoidectomy and tympanoplasty (CWUT). Nine grade II patients underwent SMCF combined with subtotal petrosectomy (SPTR), and four grade II patients underwent SMCF combined with CWUT. Seven grade III patients received SMCF combined with SPTR and dura mater reconstruction, and four grade IV patients underwent infratemporal fossa approach type B. Gross total resection was achieved in all patients, and the median follow-up time was 30.1 months (range, 4-96 months). Three patients (one grade II, one grade III, and one grade IV) had recurrence during follow-up, and the patient with grade III tumor had two recurrences. CONCLUSIONS: Gross total resection is the first-line treatment for patients with D-TGCT of the temporal bone. This novel grading system enables surgeons to select optimal surgical strategy. Long-term follow-up is mandatory postoperatively. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:1275-1284, 2022.

Grading system and surgical approaches for endolymphatic sac tumors.

PURPOSE: Endolymphatic sac tumors (ELSTs) are rare, low-grade adenocarcinomas arising from the endolymphatic sac. This study aims to present a novel grading system for ELSTs to determine the optimal management strategy. METHODS: We performed a retrospective analysis of 16 patients with 17 ELSTs. The tumor location and involved adjacent neurovascular structures on CT and MRI were selected to establish the grading system. RESULTS: Based on the novel grading system, grade III a tumors were most common (7/17), followed by grade I (4/17), grade II (3/17), and grade III b (3/17) tumors. Eight advanced ELSTs (grade III a and III b) received an infra-temporal fossa approach, while the other 6 early stage ELSTs (grade I and II) underwent either a retrolabyrinthine approach with posterior petrosectomy or a translabyrinthine approach combined with subtotal temporal bone resection. Hearing preservation was achieved in 2 grade I patients. Postoperative facial nerve function was HB II in 1 grade III a patient who underwent anterior facial nerve transposition and was HB III in 4 advanced patients who received facial nerve grafts with the great auricular nerve or facial-hypoglossal nerve anastomosis. The mean follow-up time was 35.1 months. Two grade III patients and 1 grade II patient had tumor recurrence during follow-up, among whom 1 grade III b patient had two cases of recurrence. CONCLUSION: A correct initial diagnosis was established in all patients after meticulous imaging studies. Surgical resection is still the first choice to manage patients with ELSTs. The novel grading system enables surgeons to select tailored surgical approaches. Long-term follow-up is necessary following surgical intervention.

Human Bone Marrow Mesenchymal Stem Cells Modified Hybrid Baculovirus-Adeno-Associated Viral Vectors Targeting 131I Therapy of Hypopharyngeal Carcinoma.

Hypopharyngeal carcinoma is one of the most aggressive subtypes of squamous cell carcinoma of the head and neck. Although significant progress has been made in surgical techniques, radiotherapy, and chemotherapy, the prognosis is still poor. Mesenchymal stem cells (MSCs) have attracted substantial attention as tumor-targeted cellular carriers for cancer gene therapy. We have previously shown that recombinant baculovirus-adeno-associated vectors (BV-AAV) possessed high efficiency for multi-gene coexpression in human bone marrow MSCs (BMSCs) and BV-AAV-engineered BMSCs could effectively target hypopharyngeal cancer tissues in vivo. However, it was not clear whether BV-AAV-engineered BMSCs as cellular vehicles, mediating the expression of the sodium iodide symporter (NIS), would be effective in controlling the growth of hypopharyngeal carcinoma by radioiodine therapy. We constructed a hybrid BV-AAV containing the Luc-P2A-eGFP fusion or NIS sequence to modify BMSCs (BMSCs-Bac-Luc-P2A-eGFP or BMSCs-Bac-NIS). The 125I uptake of BMSCs-Bac-NIS was analyzed by an automatic gamma counter in vitro and micro-single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging in vivo. The value of radioiodine therapy for hypopharyngeal carcinoma was evaluated by measuring tumor volume, glucose metabolism (via 2-deoxy-2-[18F] glucose [18F-FDG] positron emission tomography/CT), and proliferation of tumor cells. We demonstrated that 125I uptake of BMSCs-Bac-NIS persists over long-term in vitro (at least 8 h). Radioactive uptake could be detected by SPECT/CT 1 h after 125I injection in the BMSCs-Bac-NIS group, showing that this strategy allows for the tracking of real-time migration and transgene expression of BMSCs. Radioiodine therapy resulted in a significant reduction in tumor growth (386.93 ± 249.23 mm3 vs 816.56 ± 213.87 mm3 in controls), increased survival, and decreased SUVmax of 18F-FDG. The hybrid BV-AAV that can provide a variety of genes and regulatory elements, as a novel gene therapy strategy opens the prospect of NIS-mediated radionuclide therapy of hypopharyngeal carcinoma after MSC-mediated gene delivery.

Association between the methylation status of PCDH17 and the efficacy of neoadjuvant chemotherapy in triple-negative breast cancer.

The present study aimed to assess whether the methylation status of the protocadherin 17 gene (PCDH17) in triple-negative breast cancer (TNBC) tissues was associated with the efficacy of neoadjuvant chemotherapy (NAC). The present study included 280 patients diagnosed with TNBC using core needle biopsy. Tumor pathological diagnosis was determined via hematoxylin and eosin staining. Immunohistochemical staining was used to determine estrogen receptor, progesterone receptor, human epidermal growth factor receptor-2 and Ki-67 status. PCDH17 methylation status was analyzed using methylation-specific PCR. χ2 tests were performed to analyze differences between PCDH17 methylation status and TNBC clinicopathological features. Univariate and multivariate logistic regressions were used to analyze whether PCDH17 methylation status predicted a curative effect of NAC. The multivariate analysis included factors with P<0.2 from the univariate analysis and those that were clinically associated with NAC. A total of 228 patients were positive for PCDH17 methylation, while the remainder 52 were negative. Additionally, 107 patients achieved pathological complete response (pCR) after NAC. The pCR rate was 67.3% among the 52 patients negative for PCDH17 methylation and 31.6% among the 228 patients positive for PCDH17 methylation. Patients who were negative for PCDH17 methylation and had high Ki67 expression exhibited significantly higher pCR rates than their counterparts. The present results demonstrate that PCDH17 methylation status may predict the response to NAC in patients with TNBC. Therefore, this epigenetic characteristic may serve as an indicator of treatment efficacy.

Superior parathyroid blood supply safety in thyroid cancer surgery: A randomized controlled trial.

BACKGROUND: To evaluate the clinical value of a technique protecting blood supply to the superior parathyroid during surgery for thyroid cancer. MATERIALS AND METHODS: The observation group comprised 113 patients admitted to our hospital during the period from January 1, 2016 to December 31, 2016, who were diagnosed with thyroid cancer and treated by surgery using a technique protecting blood supply to the superior parathyroid. The control group comprised 113 patients diagnosed with thyroid cancer who were treated by surgery using the conventional technique. Postoperative parathyroid function damage and blood calcium levels were assessed in both groups. RESULTS: The incidences of hypocalcemia and low parathyroid hormone in the observation and control groups were 10.6% and 31.9%, and 14.2% and 35.4%, respectively. The relative risk (RR) of the control group was increased (RR = 3.009 for control; RR = 2.493 for observation). Univariate logistic regression analysis showed that postoperative temporary hypoparathyroidism was associated with lymph node metastasis, use of the above protective technique, and tumor size [(odds ratio, OR = 1.936, 95%CI 1.029-3.643; P = 0.041), (OR = 0.301, 95%CI 0.156-0.579; P = 0.001) and (OR = 2.022, 95%CI 1.089-3.756; P = 0.026), respectively]. Postoperative temporary hypoparathyroidism was also associated with lymph node dissection (Bilateral vs. No, P = 0.003) and T classification (T3 vs. T1, P = 0.034). Multivariate logistic regression analysis showed that, after including significant independent variables of univariate logistic regression analysis (e.g., lymph node metastasis, lymph node resection, protective technique, tumor size, and T classification), the protective technique was a factor supporting reduced incidence of postoperative temporary hypoparathyroidism (OR = 0.325, 95% CI 0.163-0.648; P = 0.001). CONCLUSION: Application of a technique protecting blood supply to the superior parathyroid during thyroid cancer surgery effectively reduced the incidence of postoperative temporary hypoparathyroidism. However, because of the imbalance in lymph node dissection between the two groups, confounding factors could not be completely eliminated, and matched pair analysis is needed to eliminate these factors.

RETRACTED: Icariin inhibits cell proliferation, migration and invasion by down-regulation of microRNA-625-3p in thyroid cancer cells.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Given the comments of Dr Elisabeth Bik regarding this article "… the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated", the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

MicroRNA-625-3p promotes the proliferation, migration and invasion of thyroid cancer cells by up-regulating astrocyte elevated gene 1.

BACKGROUND: Thyroid cancer is the most common malignancy in human endocrine system. This study aimed to investigate the effects of microRNA-625-3p (miR-625-3p) on thyroid cancer cell proliferation, migration, invasion and apoptosis, as well as underlying potential mechanism. METHODS: The relative expressions of miR-625-3p in tumor tissues and adjacent normal tissues of 20 patients with papillary thyroid cancer (PTC) were assessed using qRT-PCR. Cell transfection was used to up-regulate or down-regulate the expressions of miR-625-3p in thyroid cancer SW579 and TPC-1 cells. Effects of miR-625-3p overexpression or suppression on SW579 and TPC-1 cell viability, migration, invasion and apoptosis were detected respectively. The regulatory effect of miR-625-3p on astrocyte elevated gene 1 (AEG-1) expression was also analyzed. Then, the roles of AEG-1 in SW579 and TPC-1 cell proliferation, migration, invasion and apoptosis, as well as Wnt/ß-catenin and c-Jun N-terminal kinase (JNK) pathways activation, were evaluated. RESULTS: miR-625-3p had high expressions in tumor tissues, compared to adjacent normal tissues. Overexpression of miR-625-3p significantly promoted SW579 and TPC-1 cell proliferation, migration and invasion but had no influence on cell apoptosis. Knockdown of miR-625-3p had opposite effects, but induced cell apoptosis. AEG-1 was up-regulated by miR-625-3p overexpression and participated in the effects of miR-625-3p on SW-579 and TPC-1 cells. In addition, overexpression of AEG-1 induced the activation of Wnt/ß-catenin and JNK pathways in SW579 and TPC-1 cells. CONCLUSION: miR-625-3p promoted proliferation, migration and invasion of thyroid cancer cells by enhancing the expression of AEG-1 and activating downstream Wnt/ß-catenin and JNK pathways.

T-cadherin is associated with prognosis in triple-negative breast cancer.

The purpose of the present study was to assess the prognostic impact of T-cadherin expression in patients with triple-negative breast cancer (TNBC). On the basis of the results of immunohistochemical analysis, 106 patients with operable TNBC were divided into two groups, the T-cadherin-positive group and T-cadherin-negative group. Fisher's exact and χ2 tests were employed to analyze clinical data, which included the association between T-cadherin expression and clinicopathological features and prognosis. The log-rank test was used to examine the impact of T-cadherin expression on the 5-year disease-free survival (DFS) and the 5-year overall survival (OS) of these patients. Kaplan-Meier and Cox regression analyses were introduced to analyze DFS and OS. Compared with the T-cadherin-positive group (58.3, 52.8 and 47.2, respectively; P=0.018, P=0.017, and P=0.047), tumor size >2 cm, grade II and III (Elston-Ellis modification of Bloom-Richardson grading system), and positive lymph node status were significantly more common in the T-cadherin-negative group compared with the T-cadherin-positive group (80.0 vs. 58.3%, 75.7 vs. 52.8% and 67.1 vs. 47.2%, respectively) (P=0.018, P=0.017, and P=0.047). Compared with the T-cadherin-positive group, 5-year DFS and OS levels were significantly lower in the T-cadherin-negative group (Z=6.233, P=0.013; Z=5.366, P=0.021). Multivariate analysis revealed that negative T-cadherin expression was an independent prognostic factor for DFS (P=0.009) and OS (P=0.048). The results of the present study indicated that negative T-cadherin expression indicated a worse prognosis for patients with TNBC.

Association of T-cadherin levels with the response to neoadjuvant chemotherapy in locally advanced breast cancer.

PURPOSE: To examine the association of T-cadherin with pathologic complete response (pCR) after neoadjuvant chemotherapy for locally advanced breast cancer. RESULTS: T-cadherin expression before and after neoadjuvant chemotherapy was similar (P = 0.162). The multivariable analysis indicated that negative T-cadherin expression was independently associated with pCR after neoadjuvant TAC chemotherapy (P = 0.001). MATERIALS AND METHODS: A total of 136 patients with locally advanced breast cancer received four cycles of neoadjuvant TAC chemotherapy (docetaxel + epirubicin + cyclophosphamide), followed by surgery. T-cadherin, estrogen receptor (ER), progesterone receptor (PR), HER-2, and Ki-67 were analyzed by immunohistochemistry. The association between T-cadherin expression and pCR after neoadjuvant chemotherapy was analyzed using multivariable logistic analysis. CONCLUSIONS: Negative T-cadherin expression before and after neoadjuvant chemotherapy for locally advanced breast cancer was similar. T-cadherin could be considered an independent factor associated with the efficacy of such therapy.

T-cadherin association with clinicopathological features and prognosis in axillary lymph node-positive breast cancer.

The purpose of this study was to investigate the correlation of T-cadherin expression with clinicopathological features and prognosis in patients with axillary lymph node-positive breast cancer. Based on the immunohistochemistry results, all 142 patients with operable axillary lymph node-positive breast cancer were divided into the T-cadherin-negative and T-cadherin-positive groups. Clinical data including the association of T-cadherin expression with clinicopathological features and prognosis were analyzed using the Chi square test and Fisher's exact test using SPSS 13.0 software. The impact of T-cadherin expression on the 5-year disease-free survival (DFS) and the 5-year overall survival (OS) of these patients was measured using the log-rank test. DFS and OS were analyzed using both Kaplan-Meier function and Cox regression analyses. Compared with the T-cadherin-positive group (55.07, 28.99, and 13.4 %, respectively; P = 0.030, P = 0.0132, and P = 0.009), tumor size >2 cm, lymph-vascular invasion, and pathological stage III disease were seen more frequently in the T-cadherin-negative group (72.60, 49.32, and 31.51 %, respectively). Both 5-year DFS and 5-year OS were poorer in the T-cadherin-negative group than in the T-cadherin-positive group (log-rank test = 9.295, P = 0.002; log-rank test = 5.718, P = 0.017). On multivariate analysis, T-cadherin-negative expression remained an independent prognostic factor for DFS (P = 0.002) but not for OS (P = 0.067). Our results suggested that negative T-cadherin expression has a worse prognosis in patients with axillary lymph node-positive breast cancer.

[Detection of antibiotics in water using silver colloid films as substrate of surface-enhanced Raman scattering].

In the present paper, silver colloid films prepared by self-assembly method were used as surface-enhanced Raman scattering (SERS) active substrates to achieve trace detection of antibiotics in water. Silver colloids were prepared using the microwave heating method, and silver colloids films were prepared with self-assembly method. The enhancement of sliver colloid films to antibiotics was analysed by changing the pH value of silver colloid and times of films. Significant effects of pH value on silver colloid films were observed. And the silver colloid films with five times, prepared by silver colloids with pH 4 had the best enhancement factor. They were used as SERS active substrates to detect three antibiotics (chloramphenicol, ciprofloxacin, enrofloxacin). The experimental limits of detection were 120, 15, 120 nmol x L(-1), respectively. These results show that such substrate has a very high sensitivity and application value, and might be able to be used for trace detection of antibiotics in aquiculture.

[Detection and analysis of polycyclic aromatic hydrocarbons using surface-enhanced Raman spectroscopy].

In the present paper, the gold colloid with parameters optimized was used as surface-enhanced Raman scattering (SERS) active substrate to realize the trace detection of polycyclic aromatic hydrocarbons (PAHs) in water for the first time. Gold colloids with different size were prepared using chemical reduction method, and the optimum size selected at 632.8 nm excitation wavelength by experiment is (32 +/- 3) nm. The influence of pH value on the enhancement of PAHs was researched, and the optimal pH value is 13. Spectral intensity increased by approximately 20-fold compared with pH 6. The SERS spectra of naphthalene, phenanthrene and pyrene aqueous solutions were detected by the optimum gold colloid, and the minimum concentrations obtained were 20, 4 and 4 nmol x L(-1), respectively. There was a linear relationship between peak intensity and concentration, and the linear regression correlation coefficients were all above 0.985. For the mixture, the authors could distinguish each PAH easily for their own characteristic peaks. The experimental results show that such active substrate has a very high sensitivity as well as good application prospect.