Remnant Cholesterol and Carotid Intraplaque Neovascularization Assessed by Contrast-Enhanced Ultrasonography in Patients With Ischemic Stroke.

Background: We investigated the relationship between remnant cholesterol and carotid intraplaque neovascularization (IPN) assessed by contrast-enhanced ultrasonography (CEUS) in patients with ischemic stroke. Methods: This was a single-center study. Remnant cholesterol is calculated as total cholesterol minus low-density lipoprotein cholesterol (LDL-C) minus high-density lipoprotein cholesterol (HDL-C). All patients underwent CEUS. IPN is graded according to the presence and location of microbubbles within each plaque. Results: The cohort included 110 patients with ischemic stroke. Patients with an IPN grading of 2 had higher triglyceride (TG), non-HDL-C, and remnant cholesterol concentrations than those with an IPN grading of < 2 (TG: 1.45 ± 0.69 vs. 0.96 ± 0.24 mmol/L, P < 0.001; non-HDL-C: 2.63 ± 0.85 vs. 2.31 ± 0.64 mmol/L, P = 0.037; remnant cholesterol: 0.57 ± 0.23 vs. 0.44 ± 0.07 mmol/L, P < 0.001). The multivariate-adjusted odds ratio (95% confidence interval) for remnant cholesterol was 27.728 (2.714 - 283.253) for an IPN grading of 2 in the subset of patients with an optimal LDL-C concentration. Conclusions: The remnant cholesterol concentration is significantly associated with carotid IPN on CEUS in patients with ischemic stroke with an optimal LDL-C concentration. Remnant cholesterol may be an important indicator of risk stratification in patients with ischemic stroke.

The Value of Left Internal Mammary Artery Flow Velocity in Predicting the Prognosis of Patients After Coronary Artery Bypass Grafting.

Background: The purpose of this study was to explore the value of the left internal mammary artery flow velocity (LIMAV) measured by ultrasound before coronary artery bypass grafting (CABG) in predicting the prognosis of patients after left internal mammary artery (LIMA) bypass grafting. Methods: One hundred and four patients who underwent CABG with LIMA as the bridge vessel in the cardiovascular surgery department of our hospital between May 2018 and June 2019 were selected. All patients underwent transthoracic Doppler ultrasonography to measure LIMAV preoperatively. Intraoperatively, mean graft flow (MGF) and pulsatility index (PI) of the LIMA bridge were measured using transit time flow measurement (TTFM). The primary endpoint event in this study was cardiac death within 18 months after surgery. Results: The Cox survival analysis showed that the MGF, the LIMAV and left ventricular ejection fraction (LVEF) were risk factors for death after CABG. The cut-offs of MGF, LIMAV and LVEF for the prediction of death after CABG were ≤ 14 mL/min (area under the curve (AUC): 0.830; sensitivity: 100%; specificity: 65.6%), ≤ 60 cm/s (AUC: 0.759; sensitivity: 65.5%; specificity: 85.3%), and ≤ 44% (AUC: 0.724; sensitivity: 50%; specificity: 88.5%), respectively. Compared with the use of MGF, MGF + LIMAV, combination of the MGF + LIMAV + LVEF (AUC: 0.929; sensitivity: 100%; specificity: 81.1%) resulted in a stronger predictive value (MGF vs. MGF + LIMAV + LVEF: P = 0.02). Conclusion: LIMAV measured by preoperative transthoracic ultrasound combined with intraoperative MGF and LVEF may have a greater value in predicting patients' risk of cardiac death after CABG.

The relationship between pre-operative right ventricular longitudinal strain and low-cardiac-output syndrome after surgical aortic valve replacement.

Objectives: This study was performed to investigate the relationship between right ventricular free wall longitudinal strain (RVFWSL) and low cardiac output syndrome (LCOS) after surgical aortic valve replacement (SAVR) and to further explore its association with readmission within 2 years in patients who developed LCOS after SAVR. Methods: This single-center retrospective observational study involved consecutive patients who underwent SAVR at our hospital from May 2018 to June 2020. Preoperative echocardiography was obtained within 3 days before SAVR. The longitudinal strain of the right ventricle was analyzed using the right ventricle as the main section, and the RVFWSL and right ventricular four-chamber longitudinal strain (RV4CSL) were obtained. The primary observation was the occurrence of LCOS. The secondary prognostic indicators were mainly the readmission rates within 2 years. Results: In total, 146 patients were finally included in this study. The RVFWSL was significantly lower in the LCOS group than in the No-LCOS group (16.63 ± 2.10) vs. (23.95 ± 6.33), respectively; P < 0.001). The multivariate regression analysis showed that the RVFWSL was associated with LCOS (odds ratio, 1.676; 95% confidence interval, 1.258-2.232; P < 0.001). The receiver operating characteristic curve showed that the cut-off value for RVFWSL to predict LCOS was less than -18.3, with an area under the curve of 0.879, sensitivity of 100%, and specificity of 80.47%. The multivariate regression analysis showed that LCOS was an independent risk factor for readmission within 2 years in patients undergoing SAVR. Conclusion: Patients with RVFWSL (<-18.3%) may be an increased risker for LCOS after SAVR. The occurrence of LCOS after SAVR is Yong-jian Zhang a risk factor for readmission within 2 years. Right ventricular function monitoring may have some predictive value for the postoperative prognosis in patients undergoing SAVR.

Quantitative assessment of the aging corpus cavernosum by shear wave elastography.

We wanted to determine whether shear wave elastography (SWE) could be used to evaluate the aging degree of the corpus cavernosum (CC) and to identify the histological basis of changes in SWE measurements during the aging process. We performed a cross-sectional study enrolling healthy participants of different ages. We measured the Young's modulus (YM) of the penile CCs by SWE and assessed erectile function using the International Index of Erectile Function-5 (IIEF-5). Histological investigation was performed in surgically resected penile specimens from a separate group of patients to examine the smooth muscle and collagen content of the CCs. Furthermore, we measured the YM, erectile function, smooth muscle, and collagen content of the CCs in different age groups of rats. Finally, we enrolled 210 male volunteers in this study. The YM of the CC (CCYM) was positively correlated with age (r = 0.949, P < 0.01) and negatively correlated with erectile function (r = -0.843, P < 0.01). Histological examinations showed that CCs had increased collagen content but decreased smooth muscle content with increased age. The same positive correlation between CCYM and age was also observed in the animal study. In addition, the animal study showed that older rats, with increased CCYM and decreased erectile function, had lower smooth muscle content and higher collagen content. SWE can noninvasively and quantitatively evaluate the aging degree of the CC. Increased collagen content and decreased smooth muscle content might be the histological basis for the effect of aging on the CC and the increase in its YM.

Radiofrequency ablation for primary hyperparathyroidism and risk factors for postablative eucalcemic parathyroid hormone elevation.

OBJECTIVE: To investigate the efficacy of radiofrequency ablation (RFA) as a treatment option for primary hyperparathyroidism (pHPT) and risk factors for postablative eucalcemic parathyroid hormone elevation (ePTH). METHODS: This retrospective study included 51 patients with pHPT who underwent RFA. The patients were divided into the ePTH and normal PTH groups, based on the serum intact parathyroid hormone (iPTH) level one month after ablation. Serum iPTH, calcium, and phosphorus levels, and the volume reduction rates (VRR) of the parathyroid glands were compared between the groups at each follow-up point. Risk factors for ePTH at one month after ablation were examined. RESULTS: After RFA, one (2%) patient had persistent pHPT, and 50 (98%) patients were cured. The incidence rates of ePTH at 1, 3, 6, and 12 months were 48%, 30%, 20%, and 16%, respectively. Serum iPTH levels in the ePTH group were higher than those in the normal PTH group at each follow-up point (all p < 0.05), except 1 day after ablation (p > 0.05). Serum calcium and phosphorus levels, and the VRR of the glands were comparable in both groups at each follow-up point (all p > 0.05), except for calcium levels 3 days after RFA (p < 0.05). Baseline iPTH (odds ratio, 1.067; p = 0.045) and calcium (odds ratio, 3.923; p = 0.038) levels were independent risk factors for ePTH 1 month after RFA. CONCLUSIONS: RFA is safe and effective for the treatment of pHPT. Moreover, ePTH occurrence after RFA was associated with baseline iPTH and calcium levels and did not increase the risk of recurrent pHPT.

Comparative analysis of the quantitative parameter method and elasticity color mode method for real-time shear wave elastography in the diagnosis of benign and malignant solid breast lesions.

OBJECTIVE: To examine the performance of real-time shear wave elastography (RT-SWE) in routine clinical practice. METHODS: This was a prospective study of 500 patients. The elasticity color mode method was judged by a four-mode system. The quantitative parameter method was used to measure the modulus of elasticity of the lesions. Pathologic reports were used as a gold standard to comparatively analyze the diagnostic performance of the two methods. RESULTS: A total of 553 tumors were detected. The average mode value and the modulus of elasticity (Emax) of the benign breast masses was lower than that of malignant masses (p < 0.05). With Emax = 67.4 as the diagnostic threshold value, the sensitivity, specificity, accuracy, negative predictive value, and positive predictive value of the two methods were not statistically significant different (p > 0.05). CONCLUSIONS: The shear wave quantitative parameter method and the elasticity color mode method showed similar performances in the diagnosis of benign and malignant breast masses. The elasticity color mode method is convenient and intuitive, whereas the quantitative parameter method can be used to objectively assess the lesions when it is difficult to score the elasticity of an image, but could not be relied on alone.

Application of multimodal ultrasonography for differentiating benign and malignant cervical lymphadenopathy.

OBJECTIVES: The purpose of this study was to evaluate the diagnostic value of multimodal ultrasonography, including SWE and CEUS, for the differentiation of benign and malignant cervical lymphadenopathy. METHODS: A total of 103 patients with 109 enlarged neck lymph nodes underwent SWE and CEUS. There were 25 hyperplastic lymph nodes, 66 metastatic lymph nodes, and 18 cases of lymphoma. RESULTS: Using 31.6 kPa as the Emax cutoff, the sensitivity, specificity and accuracy of measurements on both benign and malignant cervical lymph nodes were 55.95%, 96%, and 65.2%, respectively. CEUS showed that lymph nodes with reactive hyperplasia mainly exhibited uniform perfusion via the lymphatic hilum (18/25; 72%; P < 0.01). The main manifestation of lymphoma was uniform perfusion through the lymphatic hila (10/18; 55.6%; P < 0.01). Metastatic lymph nodes mainly exhibited uneven perfusion (57/66; 86.4%; P < 0.01). The sensitivity, specificity, and accuracy of multimodal ultrasonography for the diagnosis of benign and malignant cervical lymphadenopathies were 90.5%, 72%, and 86.2%, respectively. CONCLUSIONS: Our findings suggest that multimodal ultrasonography can detect the stiffness (elasticity), perfusion pattern, and characteristics of lymph nodes and is a valuable tool for differentiating between benign and malignant lymphadenopathies.

Deep learning applied to two-dimensional color Doppler flow imaging ultrasound images significantly improves diagnostic performance in the classification of breast masses: a multicenter study.

BACKGROUND: The current deep learning diagnosis of breast masses is mainly reflected by the diagnosis of benign and malignant lesions. In China, breast masses are divided into four categories according to the treatment method: inflammatory masses, adenosis, benign tumors, and malignant tumors. These categorizations are important for guiding clinical treatment. In this study, we aimed to develop a convolutional neural network (CNN) for classification of these four breast mass types using ultrasound (US) images. METHODS: Taking breast biopsy or pathological examinations as the reference standard, CNNs were used to establish models for the four-way classification of 3623 breast cancer patients from 13 centers. The patients were randomly divided into training and test groups (n = 1810 vs. n = 1813). Separate models were created for two-dimensional (2D) images only, 2D and color Doppler flow imaging (2D-CDFI), and 2D-CDFI and pulsed wave Doppler (2D-CDFI-PW) images. The performance of these three models was compared using sensitivity, specificity, area under receiver operating characteristic curve (AUC), positive (PPV) and negative predictive values (NPV), positive (LR+) and negative likelihood ratios (LR-), and the performance of the 2D model was further compared between masses of different sizes with above statistical indicators, between images from different hospitals with AUC, and with the performance of 37 radiologists. RESULTS: The accuracies of the 2D, 2D-CDFI, and 2D-CDFI-PW models on the test set were 87.9%, 89.2%, and 88.7%, respectively. The AUCs for classification of benign tumors, malignant tumors, inflammatory masses, and adenosis were 0.90, 0.91, 0.90, and 0.89, respectively (95% confidence intervals [CIs], 0.87-0.91, 0.89-0.92, 0.87-0.91, and 0.86-0.90). The 2D-CDFI model showed better accuracy (89.2%) on the test set than the 2D (87.9%) and 2D-CDFI-PW (88.7%) models. The 2D model showed accuracy of 81.7% on breast masses ≤1 cm and 82.3% on breast masses >1 cm; there was a significant difference between the two groups (P < 0.001). The accuracy of the CNN classifications for the test set (89.2%) was significantly higher than that of all the radiologists (30%). CONCLUSIONS: The CNN may have high accuracy for classification of US images of breast masses and perform significantly better than human radiologists. TRIAL REGISTRATION: Chictr.org, ChiCTR1900021375; http://www.chictr.org.cn/showproj.aspx?proj=33139.

Suggested amendment of TI-RADS classification of thyroid nodules by shear wave elastography.

BACKGROUND: The application of the ultrasound elastography and Thyroid Imaging Reporting and Data System (TI-RADS) classification further expands the scope of ultrasound differential diagnosis between benign and malignant thyroid nodules. PURPOSE: To investigate the value of the quantitative parameter of ultrasonic shear waves in optimizing the TI-RADS classification of thyroid nodules. MATERIAL AND METHODS: A total of 168 thyroid nodules, initially classified using TI-RADS and scanned by shear wave elastography (SWE), were retrospectively analyzed. All cases were diagnosed by fine needle aspiration and histology following surgery. RESULTS: The benign rate of TI-RADS 3 nodules was 76.5%, while the benign rate of TI-RADS 4a nodules was 71.7%. Furthermore, the malignant rate of TI-RADS 4b nodules was 69.7%, while the malignant rate of TI-RADS 4c nodules was 85.7%. In differentiating benign from malignant nodules, the combination of TI-RADS classification and Emean had the largest area under the receiver operating characteristic curve (AUC). Using an Emean value of 42.25 kpa as the cut-off point, the malignant rate of TI-RADS 4a nodules decreased from 28.3% to 23.5%, while the malignant rate of TI-RADS 4b nodules increased from 69.7% to 79.4%. Compared to conventional ultrasound alone, the sensitivity, negative predictive value, and AUC of conventional ultrasound combined with SWE in the diagnosis of benign and malignant thyroid nodules significantly improved (P=0.012, 0.029, 0.001). CONCLUSION: The SWE technique can be used to further determine the benign and malignant nature of TI-RADS 4 lesions, providing further reference for the choice of clinical treatment. The TI-RADS classification system corrected by SWE is more significant in the diagnosis of benign and malignant thyroid nodules.

Undifferentiated carcinoma with osteoclast-like giant cells of pancreas: A case report with review of the computed tomography findings.

RATIONALE: Undifferentiated carcinoma with osteoclast-like giant cells (UC-OGCs) of the pancreas is an extremely rare and aggressive pancreatic malignancy. To our knowledge, the computed tomography (CT) findings of this disease have rarely been analyzed. PATIENT CONCERNS: A 65-year-old man who experienced weight loss of about 4 kg over 3 months presented to our clinic. The abdominal ultrasound (US) detected a 5.8 × 5.5 cm well-defined, cystic-solid mass in the head of the pancreas, which had been present for 1 month. DIAGNOSIS: A benign pancreatic tumor was initially suspected on the basis of the US findings. The patient then received serum tumor markers and CT examinations for further diagnosis, including carbohydrate antigen 199 (CA199), carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125), contrast-enhanced CT (CECT) and CT angiography (CTA). His CA199, CEA, and CA125 marker levels were normal, which supported the diagnosis of a benign tumor. CECT showed a well-defined cystic-solid mass in the head of the pancreas, with a slightly enhanced solid portion and pancreatic ductal dilatation, which led us to consider the possibility of a malignant tumor. CTA revealed that the tumor nourishing arteries emitted from the pancreaticoduodenal superior and inferior arteries into the mass. Then, the patient underwent a pancreaticoduodenectomy. Finally, postoperative pathology and immunohistochemistry confirmed UC-OGC of the pancreas. INTERVENTIONS: The patient has been treated by a pancreaticoduodenectomy alone. OUTCOMES: The operation had no complications, and the patient recovered well after surgery. Ten months after surgery, the patient reviewed the CECT, and no recurrence or metastasis was noted. LESSONS: Old patients with cystic-solid lesions in the pancreas should be aware of UC-OGC. CT findings usually show a clear boundary and a slightly enhanced mass with pancreatic duct expansion.

Carotid Plaque Stiffness Measured with Supersonic Shear Imaging and Its Correlation with Serum Homocysteine Level in Ischemic Stroke Patients.

Objective: To ascertain the feasibility of using shear wave velocity (SWV) in assessing the stiffness of carotid plaque by supersonic shear imaging (SSI) and explore preliminary clinical value for such evaluation. Materials and Methods: Supersonic shear imaging was performed in 142 patients with ischemic stroke, including 76 males and 66 females with mean age of 66 years (range, 45-80 years). The maximum, minimum, and mean values of SWV were measured for 129 carotid plaques. SWVs were compared between echolucent and echogenic plaques. Correlations between SWVs and serum homocysteine levels were investigated. Based on neurological symptom, the surrogate marker of vulnerable plaque (VP), binary logistic regression was performed and area under curve (AUC) of homocysteine only and homocysteine combing SWVmean was calculated respectively. Results: Echogenic plaques (n = 51) had higher SWVs than echolucent ones (n = 78) (SWVmin 3.91 [3.24-4.17] m/s vs. 1.51 [1.04-1.94] m/s; SWVmean, 4.29 [3.98-4.57] m/s vs. 2.09 [1.69-2.41] m/s; SWVmax, 4.67 [4.33-4.86] m/s vs. 2.62 [2.32-3.31] m/s all p values < 0.01). Pearson correlation analysis showed that stiffness of plaques was negatively correlated with homocysteine level. R values for SWVmin, SWVmean, and SWVmax were -0.205, -0.213, and -0.199, respectively. Binary logistic regression analysis showed that sex (p = 0.008), low-density lipoprotein (p = 0.015), triglycerides (p = 0.011), SWVmean (p = 0.004), and hyper-homocysteinemia (p = 0.010) were significantly associated with symptomatic ischemic stroke. Receiver operating characteristic curves revealed that SWVmean combing serum homocysteine level (AUC = 0.67) presented better diagnostic value than serum homocysteine only (AUC = 0.60) for symptomatic ischemic stroke. Conclusion: Supersonic shear imaging could be used to quantitatively evaluate stiffness of both echolucent and echogenic carotid plaques. More importantly, SWVs of plaques were not only correlated to serum homocysteine level, but also associated with symptomatic ischemic stroke, suggesting that SSI might be useful for understanding more about VP.

An inflammatory myofibroblastic tumor in the transplanted liver displaying quick wash-in and wash-out on contrast-enhanced ultrasound: A case report.

RATIONALE: Inflammatory myofibroblastic tumor (IMT) is an uncommon mesenchymal neoplasm, and its presence in a grafted liver is exceedingly rare. PATIENT CONCERNS: A 54-year-old woman was admitted to our hospital with a half-month history of intermittent melena. She had undergone deceased-donor liver transplantation (LT) for hepatitis B virus related liver cirrhosis without hepatocellular carcinoma 5 months previously. DIAGNOSIS: Laboratory examination showed impaired liver and renal functions and Epstein-Barr virus (EBV) infection, but tumor markers within normal ranges. Gastroscopy showed esophageal varices. Ultrasound and computed tomography angiography revealed an ill-defined and irregular solitary lesion in the porta hepatis, encasing both the portal vein and the hepatic artery. The lesion was characterized by arterial hyper-enhancement and hypo-enhancement in the remaining phases with contrast-enhanced ultrasound (CEUS). The lesion was finally confirmed as an IMT by ultrasound-guided biopsy. INTERVENTION: The patient received conservative treatment, including immunosuppression, endoscopic variceal ligation, antibiotics, steroids, and antiviral agents. OUTCOME: The patient's gastrointestinal bleeding was controlled, but the symptoms associated with portal hypertension worsened. Attempts to perform a transjugular intrahepatic portosystemic shunt were unsuccessful, and she unfortunately died soon after. LESSONS: A differential diagnosis of IMT should be considered in LT recipients presenting with EBV infection, normal tumor markers, and a de novo hepatic lesion with quick wash-in and wash-out on CEUS. Ultrasound is associated with the advantages of convenience and nonionizing radiation, and should thus be the priority approach for monitoring transplanted liver.

Correlations of microvascular blood flow of contrast-enhanced ultrasound and HGF/c-Met signaling pathway with clinicopathological features and prognosis of patients with hepatocellular carcinoma.

The study is designed to explore the correlations of microvascular blood flow of contrast-enhanced ultrasound (CEUS) and hepatocyte growth factor (HGF)/c-Met signaling pathway with clinicopathological features and prognosis of patients with hepatocellular carcinoma (HCC). One hundred and eighteen patients pathologically diagnosed as primary HCC were selected. All HCC patients underwent CEUS examination before operation. HCC tissues and adjacent normal tissue specimens were obtained to detect the protein rates of HGF and c-Met expressions by immunohistochemistry. The mRNA expressions of HGF and c-Met were detected by quantitative real-time polymerase chase reaction assay. The microvessel density (MVD) was tested by CD34 immunohistochemistry. Compared with liver parenchyma, the HCC lesions had higher MVD, preoperative peak intensity (PI), area under the curve (AUC), lower preoperative time to peak (TTP), and washout time (WOT). Compared with adjacent normal tissues, the protein and mRNA expressions of HGF were reduced in HCC tissues, but the protein and mRNA expressions of c-Met and MVD were increased. The protein expressions of HGF and c-Met exhibited evident correlations with TNM stage, tumor size, vascular invasion, liver cirrhosis, and hepatitis B virus and hepatitis C virus infection of HCC patients. The tumor size and number, vascular invasion, the protein expressions of HGF and c-Met, and MVD were associated with the TTP, PI, WOT, and AUC of CEUS in HCC patients. The protein expressions of HGF and c-Met, MVD and preoperative PI revealed negative associations with the prognosis of HCC patients. In conclusion, quantitative parameters of CEUS and HGF/c-Met signaling pathway-related proteins may be helpful for early diagnosis and prognosis prediction of HCC patients.

Contrast-enhanced ultrasound improves accurate identification of appendiceal mucinous adenocarcinoma in an old patient: A case report.

BACKGROUND: Adenocarcinoma of appendiceal origin is far rarer than other colorectal carcinomas and its preoperative diagnosis is challenging. To our knowledge, utility of contrast-enhanced ultrasound (CEUS) to diagnose it is much less. METHOD: A 61-year-old man presented with abdominal pain in the right lower quadrant for 20 days. In order to fulfill an accurately preoperative diagnosis, he received laboratory and imaging tests such as carcinoembryonic antigen (CEA), computer tomography (CT), CEUS and endoscope. DIAGNOSIS AND INTERVENTION: He was initially suspected of suffering appendicitis, while his white blood cell count was normal and carcinoembryonic antigen (CEA) in serum was remarkably increased. Both routine ultrasound and computer tomography (CT) examinations supported suppurative appendicitis. The overall data, however, failed to excluded neoplastic pathology thoroughly. Therefore, CEUS was carried out and showed an inhomogeneous enhancement intra the lesion located in the body of the appendix, which made our consideration of neoplasm. The result of the follow-up biopsy guided by endoscope was consistent with appendiceal tumor. The patient received laparoscopic right hemicolectomy. Histopathology confirmed as well differentiated mucinous adenocarcinoma of appendix origin. His postoperative course was uneventful, and he had a regular diet again without any complaint. RESULT: Serum CEA was remarkably increased (12.00 ng/mL). Both routine ultrasound and CT examinations supported suppurative appendicitis. However, CEUS examination showed an inhomogeneous enhancement intra the lesion located in the body of the appendix, which made our consideration of neoplasm. The follow-up biopsy guided by endoscope and surgical specimens confirmed as well differentiated mucinous adenocarcinoma of appendix origin. CONCLUSION: Most mucinous adenocarcinoma mimicking appendicitis results in difficult diagnosis preoperatively. Clinician and radiologist should be aware of it when old patient presented with appendicitis especially along with high level of CEA.

A novel amidase from Brevibacterium epidermidis ZJB-07021: gene cloning, refolding and application in butyrylhydroxamic acid synthesis.

A novel amidase gene (bami) was cloned from Brevibacterium epidermidis ZJB-07021 by combination of degenerate PCR and high-efficiency thermal asymmetric interlaced PCR (hiTAIL-PCR). The deduced amino acid sequence showed low identity (≤55 %) with other reported amidases. The bami gene was overexpressed in Escherichia coli, and the resultant inclusion bodies were refolded and purified to homogeneity with a recovery of 22.6 %. Bami exhibited a broad substrate spectrum towards aliphatic, aromatic and heterocyclic amides, and showed the highest acyl transfer activity towards butyramide with specific activity of 1331.0 ± 24.0 U mg(-1). Kinetic analysis demonstrated that purified Bami exhibited high catalytic efficiency (414.9 mM(-1) s(-1)) for acyl transfer of butyramide, with turnover number (K cat) of 3569.0 s(-1). Key parameters including pH, substrate/co-substrate concentration, reaction temperature and catalyst loading were investigated and the Bami showed maximum acyl transfer activity at 50 °C, pH 7.5. Enzymatic catalysis of 200 mM butyramide with 15 µg mL(-1) purified Bami was completed in 15 min with a BHA yield of 88.1 % under optimized conditions. The results demonstrated the great potential of Bami for the production of a variety of hydroxamic acids.

Mining and characterization of two amidase signature family amidases from Brevibacterium epidermidis ZJB-07021 by an efficient genome mining approach.

Amidases have received increasing attention for their significant potential in the production of valuable carboxylic acids. In this study, two amidases belonging to amidase signature family (BeAmi2 and BeAmi4) were identified and mined from genomic DNA of Brevibacterium epidermidis ZJB-07021 by an efficient strategy combining comparative analysis of genomes and identification of unknown region by high-efficiency thermal asymmetric interlaced PCR (HiTAIL-PCR). The deduced amino acid sequences of BeAmi2 and BeAmi4 showed low identity (< 40%) with other reported amidases. The two amidases displayed optimum activity toward a wide spectrum of substrates at a mild alkaline pH and 45 °C. Both of them were remarkably inactivated by serine-directed inhibitor and sulfhydryl-reducing agent. Kinetic analysis revealed that nicotinamide was the preferable substrate for both amidases and the chlorine substitutions on the pyridine ring had a negative effect on activity. The bioprocesses for hydrolysis of 100 mM nicotinamide, isonicotinamide, 2-chloronicotinamide and 5-chloronicotinamide with purified BeAmi2 (6 U mL(-1)) were complete in 60 min with full conversion except 2-chloronicotinamide. These results indicated BeAmi2 was an effective catalyst for hydrolysis of several nicotinamide derivatives.

Purification and characterization of R-stereospecific amidase from Brevibacterium epidermidis ZJB-07021.

A R-stereospecific amidase was purified from Brevibacterium epidermidis ZJB-07021 and characterized in detail. The amidase was purified to homogeneity by three chromatographic steps for up to 328.9-fold with specific activity of 31.9 U mg(-1). The enzyme was a homodimer with a molecular mass of 94 kDa. It exhibited maximum activity at 40 °C and pH 7.5. The enzyme was strongly inactivated by serine protease inhibitor PMSF. The values of Km and Vmax for racemic 2,2-dimethylcyclopropane carboxamide (DMCPCA) were 4.58 mM and 35.03 µmol min(-1) mg(-1) protein, respectively. The amidase showed a broad substrate spectrum toward aliphatic, aromatic and heterocyclic amides, but could hardly hydrolyze the bulky side-chain-containing amides. Furthermore, kinetic resolution of racemic DMCPCA by the amidase afforded S-DMCPCA in 46.3% yield and 99% ee with an average E-value of 67. These unique properties of the amidase imply that it is a promising biocatalyst for the production of chiral amides and carboxylic acids.

Concurrent obtaining of aromatic (R)-2-hydroxyacids and aromatic 2-ketoacids by asymmetric oxidation with a newly isolated Pseudomonas aeruginosa ZJB1125.

Pseudomonas aeruginosa ZJB1125 harboring a stereoselective 2-hydroxyacid dehydrogenase (2-HADH) can catalyze asymmetric oxidation of mandelic acid and 2-chloromandelic acid into (R)-isomers and corresponding 2-ketoacids with high activity and enantioselectivity, while no consecutive oxidation of 2-ketoacids was observed during whole-cell catalysis. The 2-HADH in P. aeruginosa ZJB1125 is a FMN-dependent flavoprotein and did not require NAD(P)⁺ as cofactors to catalyze the oxidation reaction. Enzyme activity staining identified 2-HADH as the key enzyme that enantioselectively oxidized (S)-hydroxyacid to 2-ketoacid. The 2-HADH in P. aeruginosa ZJB1125 is inducible and 2-chloromandelic acid was found to induce its synthesis efficiently. The bacterium displayed pretty high activity and enantioselectivity for most of the aromatic 2-hydroxyacids examined, and have a potential for the concurrent obtaining of aromatic (R)-2-hydroxyacids and aromatic 2-ketoacids in near theoretical conversions. Using a simple organic extract process, aromatic (R)-2-hydroxyacids and aromatic 2-ketoacids can be effectively separated from the biocatalytic reaction mixture with high yield (>95%). This work provided a novel method for the concurrent obtaining of aromatic (R)-2-hydroxyacids and aromatic 2-ketoacids by oxidation of aromatic 2-hydroxyacids in one-step biotransformation, which would be a valuable process due to its high atom economy.

Diagnosis of solid breast lesions by elastography 5-point score and strain ratio method.

PURPOSE: To compare the diagnostic performance of 5-point scoring system and strain ratio by sonoelastography in the assessment of solid breast lesions. MATERIAL AND METHODS: One hundred and eighty-seven solid masses in 155 patients were scanned by two-dimensional ultrasonography and sonoelastography. Elasticity scores were determined with a 5-point scoring method, and the strain ratio was based on the comparison of the average strain measured in the lesion with the adjacent breast tissue in the same depth. Pathological results were taken as gold standards to compare the diagnostic efficacy of two methods with clinical diagnostic test and receiver operating characteristic (ROC) curves. RESULTS: Among 187 lesions, 130 were benign and 57 were malignant. The mean scores (1.62±0.69 vs 4.07±0.26, P<0.05) and strain ratios (2.06±1.27 vs 6.66±4.62, P<0.05) were significantly higher of malignant than benign lesions. The area under the curve for the 5-point scoring system and for strain ratio-based elastographic analysis was 0.892 and 0.909, respectively (P>0.05). For 5-point scoring, sonoelastography had 84.2% sensitivity, 84.6% specificity, 84.5% accuracy, 70.6% positive predictive value and 92.4% negative predictive value. When a cutoff point of 3.06 was used, sensitivity, specificity, accuracy, positive and negative predictive values were 87.7%, 88.5%, 88.2%, 76.9% and 94.3%, respectively for the strain ratio (P>0.05). CONCLUSIONS: The 5-point scoring system and strain ratio has similar diagnostic performance, and the strain ratio could be more objective to differentiate the masses when those masses were difficult to be judged by using 5-point scoring system in sonoelastographic images.

Color and power Doppler sonography of extracranial and intracranial arteries in Moyamoya disease.

PURPOSE: To study the hemodynamic characteristics of moyamoya disease with color Doppler (CD) and power Doppler (PD) sonography. METHODS: The hemodynamic parameters of intracranial and extracranial arteries from 17 patients with moyamoya disease confirmed via digital subtraction angiography and 30 healthy controls were studied with conventional and transcranial CD and PD. RESULTS: The moyamoya vessels were detected as scattered color Doppler signal with low velocity and a low resistance index (RI) at the base of the brain in 10 of the 17 patients. The RI of the common carotid arteries and the internal carotid arteries of the patients was significantly higher, whereas the peak velocity was lower than in controls. The posterior carotid arteries were more frequently involved in children (43.8%) than in adults (5.6%). CONCLUSIONS: Transcranial CD and PD can be used to demonstrate the stenosis and occlusion of intracranial arteries and the abnormal vascular network at the base of the brain in most cases. Combined with the hemodynamic characteristics of extracranial arteries and the symptoms of the patients, an accurate diagnosis of moyamoya disease could be made in the majority of cases using PD.