[Clinical Application of Microwave Ablation in Potentially Resectable Colorectal Cancer With Simultaneously Multiple Liver Metastases].

Objective To analyze the clinical efficacy of microwave ablation in the colorectal cancer with simultaneously multiple liver metastases that was initially evaluated as potentially resectable. Methods The patients with potentially resectable colorectal cancer with simultaneous multiple liver metastases treated in the Department of General Surgery of the First Affiliated Hospital of Hebei North University,the Center of Minimally Invasive Therapy in Oncology of Traditional Chinese and Western Medicine in Dongzhimen Hospital of Beijing University of Chinese Medicine,and the Second Department of General Surgery in the Fourth Hospital of Hebei Medical University from October 1,2018 to October 1,2020 were selected in this study.The general data,pathological features,treatment methods,and clinical efficacy of the patients were collected.According to the treatment methods,the patients were assigned into a surgical resection group(conversion therapy+laparoscopic primary resection+hepatectomy)and a microwave ablation group(conversion therapy+laparoscopic primary resection+microwave ablation).The surgical indicators(operation duration,time to first postoperative anal exhaust,hospital stay,etc.)and postoperative complications(anastomotic stenosis,anastomotic hemorrhage,incision infection,etc.)were compared between the two groups.The survival period was followed up,including the overall survival period and disease-free survival period,and the survival curves were drawn to analyze the clinical efficacy of the two treatment regimens. Results A total of 198 patients with potentially resectable colorectal cancer with simultaneous multiple liver metastases were included in this study.Sixty-six patients were cured by neoadjuvant chemotherapy(FOLFOX or FOLFIRI),including 30 patients in the surgical resection group and 36 patients in the microwave ablation group(with 57 tumors ablated).After the first ablation,54(94.74%)tumors achieved complete ablation,and all of them reached no evidence of disease status after re-ablation.The microwave ablation group had shorter operation duration,less intraoperative blood loss,shorter time to first postoperative anal exhaust,shorter time of taking a liquid diet,shorter hospital stay,and lower hospitalization cost than the surgical resection group(all P<0.001).In addition,the microwave ablation group had lower visual analogue scale score(P<0.001)than the surgical resection group.The incidences of complications such as incision infection(P=0.740),anastomotic fistula(P=1.000),and anastomotic stenosis(P=1.000),the overall survival period(P=0.191),and the disease-free survival period(P=0.934)showed no significant differences between the two groups. Conclusions For patients with colorectal cancer with simultaneous multiple liver metastases initially assessed as potentially resectable,laparoscopic primary resection+surgical resection/microwave ablation after conversion therapy was safe,effective,and had similar survival outcomes.Microwave ablation outperformed surgical resection in postoperative recovery,economy,and tolerability,being worthy of clinical promotion.

Pancreatic ductal adenocarcinoma with synchronous and metachronous hepatic metastasis predicted by contrast-enhanced ultrasound.

Background: Contrast-enhanced ultrasound (CEUS) has proven valuable in diagnosing benign and malignant pancreatic diseases, but its value in evaluating hepatic metastasis remains to be further explored. This study investigated the relationship between CEUS features of pancreatic ductal adenocarcinoma (PDAC) and concomitant or recurrent liver metastases after treatment. Methods: This retrospective study included 133 participants with PDAC who were diagnosed with pancreatic lesions with CEUS at Peking Union Medical College Hospital from January 2017 to November 2020. According to the CEUS classification methods in our center, all the pancreatic lesions were classified as either with rich or poor blood supply. Additionally, quantitative ultrasonographic parameters were measured in the center and periphery of all pancreatic lesions. CEUS modes and parameters of the different hepatic metastasis groups were compared. The diagnostic performance of CEUS was calculated for diagnosing synchronous and metachronous hepatic metastasis. Results: The proportions of rich blood supply and poor blood supply were 46% (32/69) and 54% (37/69), respectively, in the no hepatic metastasis group; 42% (14/33) and 58% (19/33), respectively, in the metachronous hepatic metastasis (MHM) group; and 19% (6/31) and 81% (25/31), respectively, in the synchronous hepatic metastasis (SHM) group. The wash-in slope ratio (WIS ratio) between the center of the lesion and around the lesion and peak intensity ratio (PI ratio) between the center of the lesion and around the lesion had higher values in the negative hepatic metastasis group (P<0.05). In predicting synchronous and metachronous hepatic metastasis, the WIS ratio had the best diagnostic performance. The sensitivity (SEN), specificity (SPE), accuracy (ACC), positive predictive value (PPV), and negative predictive value (NPV) were 81.8%, 95.7%, 91.2%, 90.0%, and 91.7%, respectively, for MHM; and 87.1%, 95.7%, 93.0%, 90.0%, and 94.3%, respectively, for SHM. Conclusions: CEUS would be helpful in image surveillance for synchronous or metachronous hepatic metastasis of PDAC.

Expert Consensus on Pathological Diagnosis of Intrahepatic Cholangiocarcinoma (2022 version).

Intrahepatic cholangiocarcinoma (iCCA) can originate from the large bile duct group (segment bile ducts and area bile ducts), small bile duct group (septal bile ducts and interlobular bile ducts), and terminal bile duct group (bile ductules and canals of Hering) of the intrahepatic biliary tree, which can be histopathological corresponding to large duct type iCCA, small duct type iCCA and iCCA with ductal plate malformation pattern, and cholangiolocarcinoma, respectively. The challenge in pathological diagnosis of above subtypes of iCCA falls in the distinction of cellular morphologies, tissue structures, growth patterns, invasive behaviors, immunophenotypes, molecular mutations, and surgical prognoses. For these reasons, this expert consensus provides nine recommendations as a reference for standardizing and refining the diagnosis of pathological subtypes of iCCA, mainly based on the 5th edition of the World Health Organization Classification of Tumours of the Digestive System.

Comparative effects of different enzymatic hydrolysates of konjac glucomannan on gut flora and constipation in rats.

This study aimed to compare the effects of different hydrolysates (named GKOS and MKOS) on constipated rats, which were obtained by degradation from konjac glucomannan by ß-glucanase and ß-mannanase, respectively. GKOS and MKOS were characterized and administered by gavage at 100 mg kg-1 to constipated rats. The variation of the gut flora, content of short-chain fatty acids (SCFAs), defecation function, gastrointestinal motility, and intestinal mucus secretion were determined to evaluate their regulatory effects on constipation. The results revealed the more prominent augmentation of species richness in MKOS than with GKOS. They also possessed diverse modulatory effects on different genera, such as Prevotella and Parabacteroides. Unexpectedly, there was no statistical divergence between GKOS and MKOS in defecation parameters, gastrointestinal transit, serum parameters, and mucous secretion. Overall, MKOS and GKOS exhibited differential regulatory function on gut microbiota in vivo, but with nearly consistent therapeutic effects on constipation.

Evaluation of the diagnostic performance of the EFSUMB CEUS Pancreatic Applications guidelines (2017 version): a retrospective single-center analysis of 455 solid pancreatic masses.

OBJECTIVES: To explore the diagnostic performance of EFSUMB CEUS Pancreatic Applications guidelines (version 2017) before and after the addition of iso-enhancement and very fast/fast washout as supplementary diagnostic criteria for PDAC. METHODS: In this retrospective study, patients diagnosed with solid pancreatic lesions from January 2017 to December 2020 were evaluated. Pancreatic ductal adenocarcinoma (PDAC) is reported to show hypo-enhancement in all phases according to the EFSUMB guidelines. First, based on this definition, all lesions were categorized as PDAC and non-PDAC. Then, iso-enhancement and very fast/fast washout were added as supplementary diagnostic criteria, and all lesions were recategorized. The diagnostic performance was assessed in terms of the accuracy (ACC), sensitivity (SEN), specificity (SPE), positive predictive value (PPV), and negative predictive value (NPV). The reference standard consisted of histologic evaluation or composite imaging and clinical follow-up findings. RESULTS: A total of 455 nodules in 450 patients (median age, 58.37 years; 250 men) were included. The diagnostic performance using the EFSUMB CEUS guidelines for PDAC had an ACC of 69.5%, SEN of 65.4%, SPE of 84%, PPV of 93.5%, NPV of 40.6%, and ROC of 0.747. After recategorization according to the supplementary diagnostic criteria, the diagnostic performance for PDAC had an ACC of 95.8%, SEN of 99.2%, SPE of 84%, PPV of 95.7%, NPV of 96.6%, and ROC of 0.916. CONCLUSION: The EFSUMB guidelines and recommendations for pancreatic lesions can effectively identify PDAC via hypo-enhancement on CEUS. However, the diagnostic performance may be further improved by the reclassification of PDAC lesions after adding iso-enhancement and very fast/fast washout mode. KEY POINTS: • In the EFSUMB guidelines, the only diagnostic criterion for PDAC is hypo-enhancement, to which iso-enhancement and very fast/fast washout mode were added in our research. • Using hypo-enhancement/iso-enhancement with very fast/fast washout patterns as the diagnostic criteria for PDAC for solid pancreatic masses on CEUS has high diagnostic accuracy. • The blood supply pattern of PDAC can provide important information, and CEUS has unique advantages in this respect due to its real-time dynamic attenuation ability.

A Strategy for Screening the Lipid-Lowering Components in Alismatis Rhizoma Decoction Based on Spectrum-Effect Analysis.

Alismatis Rhizoma decoction (ARD), comprised of Alisma plantago-aquatica subsp. orientale (Sam.) Sam and Atractylodes macrocephala Koidz. at a ratio of 5 : 2, is a classic traditional Chinese medicine (TCM) formula with successful clinical hypolipidemic effect. This paper aimed to explore the major bioactive compounds and potential mechanism of ARD in the treatment of hyperlipidemia on the basis of spectrum-effect analysis and molecular docking. Nine ARD samples with varying ratios of the constituent herbs were prepared and analyzed by UPLC-Q-TOF/MS to obtain the chemical spectra. Then, the lipid-lowering ability of the nine samples was tested in an oleic acid-induced lipid accumulation model in human hepatoma cells (HepG2). Grey relational analysis and partial least squares regression analysis were then performed to determine the correlation between the chemical spectrums and lipid-lowering efficacies of ARD. The potential mechanisms of the effective compounds were investigated by docking with the farnesoid X receptor (FXR) protein. The results indicated that alisol B 23-acetate, alisol C 23-acetate, and alisol B appeared to be the core effective components on hyperlipidemia in ARD. Molecular docking further demonstrated that all three compounds could bind to FXR and were potential FXR agonists for the treatment of hyperlipidemia. This study elucidated the effective components and potential molecular mechanism of action of ARD for treating hyperlipidemia from a perspective of different compatibility, providing a new and feasible reference for the research of TCM formulas such as ARD.

Identification of the bioactive components of Banxia Xiexin Decoction that protect against CPT-11-induced intestinal toxicity via UPLC-based spectrum-effect relationship analyses.

ETHNOPHARMACOLOGICAL RELEVANCE: Irinotecan (CPT-11) is a valuable chemotherapeutic compound, but its use is associated with severe diarrhea in some patients. The CPT-11 prodrug is converted into the active 7-ethyl-10-hydroxycamptothecin (SN-38) metabolite, which can then be retained for extended periods in the intestine, leading to the onset of diarrhea and related symptoms. Banxia Xiexin Decoction (BXD) is commonly employed for the treatment of gastroenteritis in traditional Chinese medicine (TCM), and in clinical settings, it is used to prevent diarrhea in patients undergoing CPT-11 treatment. To date, however, there have been no studies specifically examining which components of BXD can alleviate the gastrointestinal symptoms associated with CPT-11 administration. AIM: This study aimed to identify the main herbal components of BXD associated with protection against CPT-11-induced intestinal toxicity in a murine model system. MATERIALS AND METHODS: SN-38 levels were measured by UPLC-ESI-MS/MS in samples collected from mice subjected to CPT-11-induced diarrhea that had been administered BXD or different components thereof. Pearson correlation and Grey relational analyses were then used to explore spectrum-effect relationships between reductions in intestinal SN-38 levels and specific chemical fingerprints in samples from mice administered particular combinations of BXD component herbs. RESULTS: We found that different herbal combinations were associated with significant differences in intestinal SN-38 reductions in treated mice. Our spectrum-effect analysis revealed that BXD components including chrysin 6-C-arabinoside-8-C-glucoside, coptisine, hydroxyl oroxylin A 7-O-glucuronide (hydroxyl wogonoside), baicalin, an isomer of 5,6,7-trihydroxyl-flavanone-7-O-glucuronide, berberine, palmatine, and chrysin-7-O-glucuronide were all directly linked with reductions in intestinal SN-38 levels. We therefore speculate that these compounds are the primary bioactive components of BXD, suggesting that they offer protection against CPT-11-induced diarrhea. CONCLUSION: By utilizing UPLC to analyze SN-38 levels in mice treated with a variety of herbal combinations, we were able to effectively explore BXD spectrum-effect relationships and to thereby establish the components of this medicinal preparation that were bioactive and capable of preventing CPT-11-induced diarrhea in mice. This and similar spectrum-effect studies represent a robust means of exploring the mechanistic basis for the pharmacological activity of TCM preparations.

RNF43 Mutations in IPMN Cases: A Potential Prognostic Factor.

An intraductal papillary mucinous neoplasm (IPMN) is a common pancreatic precursor lesion, and it often harbors mutations in KRAS, GNAS, and RNF43. To clarify the molecular profiles of IPMNs, we conducted mutation analysis of KRAS, GNAS, and RNF43 in 61 IPMN formalin-fixed, paraffin-embedded (FFPE) specimens. The mutation rates of codons 12, 13, and 61 in KRAS and codon 201 in GNAS were detected by Sanger sequencing. Next-generation sequencing was performed on RNF43, and the results were further verified by Sanger sequencing. We identified KRAS and GNAS mutations in 35 (57%) and 40 (66%) IPMN cases, respectively. GNAS mutations were significantly correlated with the morphologic subtype (P < 0.001) and were more prevalent in the intestinal subtype (93%) than in the gastric (55%) and pancreatobiliary subtypes (44%) but were absent in the oncocytic subtype. RNF43 mutations were found in 5 cases (8%), all of which occurred in high-grade dysplasia and invasive lesions (2/5 and 3/5). All 5 cases harboring RNF43 mutations also exhibited GNAS mutations. RNF43 mutations were associated with a worse prognosis in invasive IPMN patients (P = 0.002), while KRAS and GNAS mutations did not affect the prognosis of patients.

[Visually Isoattenuating Pancreatic Acinar Cell Carcinoma:Report of One Case].

Acinar cell carcinoma of pancreas(ACCP)is a rare pancreatic exocrine tumor that accounts for about 1% of pancreatic tumors. The typical imaging manifestations of ACCP are as follows:(1)the tumor is large in volume,partially or completely exophytic;(2)complete or incomplete capsule is visible with thin linear enhancement;(3)CT density and MRI signal:plain CT images reveals that the tumors have similar or slightly hypodense densities relative to the adjacent normal pancreas,the solid part of ACCP has low to intermediate signal intensity on T1WI and intermediate to high signal intensity on T2WI compared with the surrounding normal pancreas;(4)pattern of enhancement:tumors exhibit heterogeneous enhancement and it is less than that in the surrounding normal pancreas;(5)fissure-like,swirling necrosis that may be a characteristic change of tumor;(6)pancreatic and biliary duct dilatation is rare;(7)adjacent organs and blood vessels around the pancreas may be invaded;(8)distant metastasis of liver and other parts may be observed;(9)PET-CT shows high FDG uptake. An ACCP patient with atypical imaging manifestations was treated in Peking Union Medical College Hospital from November 2015 to August 2017. The lesion manifested iso-enhancement and many imaging examinations failed to find the tumor. The patient ultimately underwent surgery and diagnosed as ACCP by pathology.

Clinical characteristics and bisphosphonates treatment of rare pregnancy- and lactation-associated osteoporosis.

Pregnancy- and lactation-associated osteoporosis (PLO) is a rare disorder with poorly known etiology, pathophysiology, and therapy. We aimed to investigate the clinical characteristics of PLO and evaluate the effectiveness and safety of bisphosphonates on it. A total of 12 patients were diagnosed with PLO on the basis of medical history, bone mineral density (BMD), and/or fragility fractures during pregnancy and lactation. We investigated the clinical, biochemical, and radiological characteristics of patients. We assessed the effects of alendronate or zoledronic acid through observing the changes of bone turnover biomarkers and BMD during the treatment. Secondary osteoporosis was excluded by comprehensive differential diagnosis. The mean age of these patients was 31 ± 5 years old. All of these patients presented severe back pain. Multiple vertebral compression fractures (VCFs) were found in 10 patients, and the median (P25th, P75th) number of compressed vertebra was 3 (3, 5). Ten patients had vitamin D insufficiency or deficiency. Serum level of bone resorption marker (ß-CTX with mean of 0.68 ± 0.41 ng/ml) was moderately higher than the normal range. BMD at lumbar spine, femoral neck, and total hip were low as 0.894 ± 0.153 g/cm2, 0.728 ± 0.090 g/cm2, and 0.728 ± 0.080 g/cm2, respectively. Either alendronate or zoledronic acid could effectively relieve bone pain, reduce ß-CTX level, and increase BMD. PLO is a rare type of osteoporosis, which was characterized by increased bone resorption and decreased BMD, even VCFs. Bisphosphonate therapy was well tolerated and effective in management of PLO, but needed to be further verified in randomized controlled trial.

Intraductal papillary mucinous neoplasms of the pancreas: Clinical association with KRAS.

Intraductal papillary mucinous neoplasms of the pancreas (IPMN) are among the most important precancerous lesions in the pancreas. V­Ki­ras 2 Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the most important genes involved in pancreatic neoplasms, and exhibits a high mutation rate in pancreatic ductal adenocarcinomas and pancreatic intraepithelial neoplasia. The present study aimed to further elucidate the associations among IPMN subtypes (gastric, intestinal, pancreatobiliary and oncocytic), pathological classifications [low­grade, intermediate­grade, and high­grade IPMN, and associated minimally invasive carcinoma (invasive depth ≤0.5 cm) and advanced invasive carcinoma (invasive depth >0.5 cm)]. A total of 56 cases of IPMN were studied using scorpion amplified refractory mutation system analysis of KRAS mutations, pathological features and prognosis. KRAS mutations were identified in 50% (28/56 cases). The frequency was 60% (9/15 cases) in gastric­type, 52.6% (10/19 cases) in intestinal­type, 47.3% (9/19 cases) in pancreatobiliary­type and zero (0/3 cases) in oncocytic­type IPMN. Except for oncocytic type IPMN, the frequencies of KRAS mutations in IPMN with low, intermediate and high grade, and IPMN­associated carcinoma were 58.3% (7/12 cases), 27.3% (3/11 cases), 80% (4/5 cases) and 56% (14/25 cases), respectively. With more advanced dysplasia and invasion, the prevalence of KRAS mutations in intestinal­type IPMN increased (P=0.012). The Kaplan­Meier survival curve demonstrated that survival rate was not associated with KRAS mutation (log­rank test; P=0.308). The prevalence of KRAS mutations was lowest in intestinal­type IPMN, and was in proportion to the degree of dysplasia and invasion. Therefore, KRAS mutation in IPMN does not correlate with histological subtype, dysplasia grade, depth of invasion or survival.

Pancreatic carcinosarcoma mimics malignant intraductal papillary mucinous neoplasm: A rare case report and literature review.

RATIONALE: Carcinosarcoma, an extremely rare pancreatic primary tumor, is characterized by coexistence of both carcinomatous and sarcomatous components. Due to its rarity, the clinical manifestation and imaging features have not been recognized. An accurate diagnostic method has not been available and a widely accepted guidelines instructing treatment has not been established. PATIENT CONCERNS: We present an uncommon case of pancreatic carcinosarcoma (PCS) which has been preoperatively diagnosed as pancreatic malignant intraductal papillary mucinous neoplasm. A radical resection, including total pancreatectomy (TP) and splenectomy, was performed. DIAGNOSIS: The diagnosis of PCS was confirmed by postoperative pathology. INTERVENTIONS: A radical resection, including TP and splenectomy, was performed. The patient was followed up by abdominal contrast-enhanced computed tomography scan and blood tumor marker examination. OUTCOMES: The patient is still alive and self-sufficient 7 months after the surgery. No evidence of tumor recurrence is found during follow-up. LESSONS: Although, until recently, there are no widely accepted guidelines instructing treatment for PCS, a radical resection is still a possible way. All the pancreatic neoplastic patients with high surgical risk should be transferred to a specialized high-volume pancreatic center to get precise preoperative evaluation, fine operation technique, and careful postoperative management.

Clinicopathological Features of Intraductal Pancreatic Neuroendocrine Tumors.

Objective To evaluate the clinical and pathologic characteristics of intraductal pancreatic neuroendocrine tumors (PanNETs). Methods Four cases of intraductal PanNETs were studied by light microscopy and immunohistochemistry with the analysis of morphologic features and review of relevant literatures. Results Two female patients and two male patients aged 41- 58 years were enrolled in this study. The chief complaint was abdominal pain in two patients,vomiting in one patient,and jaundice in the last patient. Imaging examination showed intraductal neoplasm with diagnosis as intraductal papillary mucinous neoplasm (IPMN) in case 1; space-occupying lesions were found in the head of pancreas in the other three cases with pancreatic ductal ectasia and distal pancreatic atrophy. Grossly the masses were located in pancreatic main duct and invaded into surrounding pancreatic parachyma. Microscopically the tumors arranged with solid pattern,with some trabecular structures in the last two cases. Small duct and ductules were seen in intraductal PanNETs. The immunohistochemical expression showed that SYN and CgA were positive in neoplastic cells and negative in small duct and ductules.Conclusions Intraductal PanNETs are rare conditions. The clinical symptoms and imaging findings are similar to IPMN or pancreatic carcinoma. The tumors are located within pancreatic duct partly and can invade the pancreatic parenchyma. Microscopically the neuroendocrine tumors mix with small duct and forms ductulo-insular structure,which should be differentiated with mixed ductal endocrine carcinoma. The grade and prognosis are similar to those of classical neuroendocrine tumors.

Mixed large cell neuroendocrine carcinoma and adenocarcinoma of the gallbladder: a case report and brief review of the literature.

Large-cell neuroendocrine carcinoma (LCNEC) of the gallbladder is extremely rare. We present a 63-year-old Chinese female who was admitted with right upper quadrant pain and a quasi-circular tumor measuring 2.0 cm on the body of the gallbladder, as indicated by computed tomography. LCNEC combined with adenocarcinoma was immunohistochemically confirmed after open radical cholecystectomy. Postoperative recovery of this patient was uneventful, and no evidence of recurrence or metastasis was observed after 12 months of follow-up. LCNEC of the gallbladder is thought to be extremely rare and is usually found in combination with other histological carcinoma types, such as adenocarcinoma, as determined histologically. The prognosis is poor overall, but early detection with complete resection may result in a relatively good prognosis.

[Intraductal tubulopapillary neoplasm of the pancreas: a clinicopathologic study of 6 cases].

OBJECTIVE: To study the pathologic features, diagnosis, differential diagnosis and molecular characteristics of intraductal tubulopapillary neoplasm of the pancreas (ITPN). METHODS: The clinical findings, morphologic features, immunophenotype (by EnVision method) and KRAS gene alterations (by reverse transcriptase-polymerase chain reaction) of 6 cases of ITPN encountered during the period from January, 2001 to June, 2010 were analyzed. RESULTS: There were altogether 2 males and 4 females. The mean age of the patients was 64 years. Gross examination showed that the tumors were located in large pancreatic ducts and appeared as polypoid nodules with ductal obstruction. Solid tumor nodules associated with adjoining dilated ducts were identified in one case. Histologically, the tumors were characterized by tubulopapillary growth pattern without luminal mucin. The tumor cells showed high-grade nuclear atypia with scanty intracytoplasmic mucin. Intraductal necrotic foci were frequently observed. Immunohistochemical study showed that the tumor cells expressed CK7 and CK19. Focal positivity for MUC5AC was demonstrated. Two cases expressed MUC1. The staining for MUC2 was negative. KRAS gene mutations were identified in 2 cases, with a single-amino-acid substitution in codon 12 (35G > A and 35G > T/34G > A). CONCLUSIONS: ITPN is a newly described pancreatic intraductal neoplasm and different from intraductal papillary mucinous neoplasm. ITPN is characterized by intraductal tubulopapillary growth pattern, severe cytologic atypia and scanty mucin secretion.

[Assessment of the effect of influent NH+4-N concentration on the abundance and community structure of functional bacteria in CANON process].

To investigate macroscopic performance and microcosmic ecosystem of CANON process in low ammonium concentration at room temprature, a steady-operation CANON reactor was achieved in different ammonium concentrations by adjusting aeration and hydraulic retention time (HRT), and the effect of ammonium concentration on the abundance and community structure of functional bacteria was analyzed using PCR-DGGE and real-time PCR. The results indicated a high TN removal loading of over 1.0 g.(L.d)-1 in relatively high ammonium which was significantly reduced with the ammonium concentration of 100 mg.L-1. The community structure of ammonium oxidizing bacteria (AOB) changed sharply with the decrease of ammonium concentraion, which was not the same as anaerobic ammonium oxidizing bacteria (ANAMMOX bacteria). Besides, the abundance of the two functional groups of bacteria reduced while the population of nitrite oxidizing bacteria (NOB) rose with the decrease of ammonium, which might be the main reason for the reduction of nitrogen removal efficiency. Consequently, some strategies are needed to reduce the loss of AOB and ANAMMOX bacteria and inhibit the growth of NOB so as to maintain the nitrogen removal performance in low ammonium concentration.

Microbial characteristics of a CANON reactor during the start-up period seeding conventional activated sludge.

An up-flow oxygen-controlled biofilm reactor filled with volcanic filter was used for a completely autotrophic nitrogen-removal over nitrite (CANON) process. The reactor was successfully established by seeding conventional activated sludge at ambient temperature without additional biomass inoculation. An average total nitrogen (TN) removal rate of 1.1 kg·(m(3) d)(-1) was achieved after 180 days' operation. The bacterial morphology, community structure and spatial distribution of nitrogen removal microorganisms were analyzed by using some molecular biotechniques. Denaturant gel gradient electrophoresis (DGGE) profiles showed a distinct community shift of nitrite oxidizing bacteria (NOB) during the start-up period, which was not the same as that of aerobic ammonium-oxidizing bacteria (AerAOB) or anaerobic ammonium-oxidizing bacteria (AnAOB). Phylogenetic results indicated the predominance of Nitrosomonas, 'Candidatus Brocadia fulgida' and Nitrobacter for nitrogen removal in the system, all of which coexisted without a distinguishable niche on the biofilm.

Contrast-enhanced ultrasound study of primary hepatic angiosarcoma: a pitfall of non-enhancement.

OBJECTIVE: To investigate the contrast-enhanced ultrasound (CEUS) characteristics of primary hepatic angiosarcoma (PHA). METHODS: The sonographic findings and CEUS images of PHA in three patients were retrospectively analyzed. RESULTS: In our study, 3 cases of PHA (2 multiple nodules and 1 solitary mass) showed similar enhancement pattern on CEUS, characterized by remarkable central non-enhancement and peripheral irregular enhancement in the arterial and portal phase, and complete wash-out in the late phase. Furthermore, we unexpectedly found that abundant neoplastic tissues were present in the central area of non-enhancement on pathological evaluation. Based on literature review, we supposed that the unusual finding may be associated with the very low velocity of blood flow in the central region of tumors. CONCLUSION: CEUS could well depict PHA with some common features, which may provide valuable clues in diagnosis of this rare disease. And non-necrotic tumor tissue of PHA could also demonstrate non-enhancement on CEUS, which warrant further investigations.