Search

AmpC is a class C Ambler β-lactamase that confers resistance to cephamycins. Globally reported AmpC-producing Enterobacterales are clinically important due to their therapeutic restrictions and epidemiology. Between April 2021 and May 2021, an outbreak of AmpC beta-lactamase-producing Escherichia coli occurred at Showa University Hospital. Because of this outbreak, plasmid typing, enterobacterial repetitive intergenic consensus-polymerase chain reaction （ERIC-PCR） analysis, conjugation experiments, and pulsed-field gel electrophoresis （PFGE） were performed to study the molecular epidemiological characteristics of these E. coli strains. ERIC-PCR and conjugation experiments detected IncFrepB＋, IncFIA＋, and IncFIB＋ multiple-replicon conjugative plasmids carrying the AmpC gene （blaDHA-1）. Five of eleven isolates showed the same PFGE banding pattern in the XbaI-digested genomic DNA, whereas the remaining six strains displayed minor variants. These data highlight the need for improvements to infection control and surveillance measures to prevent the spread of blaDHA-1-carrying E. coli strains.

The precise measurement and detection of a tumor is indispensable in establishing the regular use of minimally invasive procedures for breast cancer treatment. We, herein, focused on ultrasonography （US） and magnetic resonance imaging （MRI）, and evaluated their effectiveness in measuring the tumor size of ductal carcinoma in situ （DCIS）. Furthermore, we assessed the DCIS subtype and its relationship with the accuracy of the imaging modalities and some critical histopathological characteristics. A total of 102 DCIS cases （that were diagnosed from 2018 to 2021） were retrospectively analyzed. The tumor sizes measured by US and MRI were compared with those obtained by the postoperative histological examination of the tumors. The DCIS subtypes were classified based on the nuclear grade and immunohistochemical （IHC） pattern; namely, estrogen/progesterone receptor expressing status, human epidermal growth factor receptor 2 （HER2） expressing status, and Ki-67 index. Tumors classified as HER2-enriched DCIS exhibited a high nuclear grade and a high Ki-67 index （Ki-67＞20％） when compared with the luminal DCIS tumors （p＜0.05）. The tumor size measured by US was smaller than the actual tumor size in all DCIS subtypes, while MRI systematically overestimated the tumor size with the exception of the triple-negative DCIS. The median tumor size differences identified between MRI and histopathology were smaller than those identified between US and histopathology, especially in HER2-enriched DCIS cases （p＝0.01）. The HER2-enriched DCIS tumors were more accurately measured by MRI than by US. MRI could measure the DCIS tumor size more accurately than US, especially in HER2-enriched DCIS cases （p＝0.01）. These results might be particularly useful in developing a more tailored DCIS management strategy.

We have reported the possibility of an outbreak of a plasmid-borne carbapenemase-producing Enterobacteriaceae at Showa University Hospital using conjugal transfer experiments; however, we could not perform plasmid profiling and fingerprinting to identify the plasmid responsible for the outbreak in clinical isolates. Therefore, to distinguish whether the appearance of metallo-β-lactamase IMP-11 （blaIMP-11）-producing Enterobacter cloacae （E. cloacae） was due to the same plasmid, we established a plasmid testing system involving plasmid isolation, typing, profiling, and fingerprinting, as well as DNA sequencing analysis of genes surrounding the carbapenemase-encoding gene. Plasmid fingerprinting is an essential tool for identifying plasmids when next-generation sequencing methods cannot be employed. Of note, an important step in fingerprinting is plasmid isolation, which is difficult when large plasmids are involved. In addition, plasmid profiling using S1 nuclease pulse-field gel electrophoresis （PFGE） Southern blotting is an important tool for profiling the size and number of plasmids in bacteria. In this study, we successfully isolated an approximately 90-kb IncL/M plasmid by employing our plasmid analysis system. Importantly, as different blaIMP-11-producing E. cloacae isolates carried the same type of plasmid, with similar size and fingerprinting pattern, we suggest that the isolated IncL/M plasmid is the one present in this strain.

Some studies have reported that adrenomedullin （AM） is involved in diabetes mellitus （DM） associated with pancreatic cancer. Therefore, in this study we investigated the relationship between diabetes and AM expression in patients with pancreatic cancer. We examined 48 biopsies and 26 surgical resections from 74 patients with histologically diagnosed pancreatic cancer. Patients were classified into either DM or non-DM groups. The immunohistochemical expression of AM and various clinicopathological factors were compared between the two groups. Among the biopsy cases, 21 were classified as DM and 27 as non-DM. AM expression in pancreatic cancer cells was significantly lower in the DM group （p＝0.03）. No significant differences were noted in age, body mass index, tumor diameter or location, serum CA19-9, amylase, or C-reactive protein levels, pancreatic ductal dilatation, portal vein invasion, clinical stage, or histological differentiation between the DM and non-DM groups. The proportion of men was significantly lower in the DM group （p＝0.04）, as was the frequency of liver metastasis at diagnosis （p＝0.03）. Among the resection cases, 13 were classified as DM and 13 as non-DM. There were no significant differences in AM expression in pancreatic cancer cells between the two groups. However, marked AM expression was observed in the inflammatory cells and fibroblasts of the tumor stroma in all cases. In addition, the inflammatory response in the tumor stroma tended to be stronger in the DM group. Although the present study failed to find a positive correlation between diabetes and AM expression in pancreatic cancer cells, the results indicate that AM expression in stromal cells may be more closely related to the development of DM in pancreatic cancer patients.

The relationship between the clinicopathological features and the grade of cellular dysplasia of the neoplastic glands in mass-forming gallbladder cancer was investigated. In this retrospective study, 41 mass-forming （≧1cm） gallbladder cancer specimens from 83 resected cases were examined. Tumors were classified into three groups: Group A had intraluminal masses consisting of neoplastic glands with only low-grade dysplasia; Group B had mixed low- and high-grade dysplasia, and Group C had only high-grade dysplasia. Of the 41 tumors, 13 were classified as Group A, 11 as Group B, and 17 as Group C. For Group A, B, and C, respectively, the mean tumor diameter was 1.6, 3.7 and 3.4cm; macroscopic type （pedunculated/semi-pedunculated/sessile） was 7/5/1, 4/6/1 and 0/10/7; frequency of an invasive component inside the mass was 0％, 9％ and 82％; and cell lineage （biliary/metaplastic/mixed） was 2/1/10, 8/1/2 and 14/1/2. In addition, invasion depth （Tis＋T1/T2/T3） was 13/0/0, 7/4/0 and 3/10/4; lymph node metastases were present in 0％, 9％ and 24％ of patients; 3-year survival rate was 100％, 100％ and 82％; and 5-year survival rate was 100％, 100％ and 69％, for A, B and C, respectively. Significant intergroup differences were seen for positive lymph node metastasis rate and 5-year survival rate. The present study indicates that the clinicopathological features of mass-forming gallbladder cancer are different depending on the grade of cellular dysplasia of the mass lesion. The tumors in Groups A and B were of lower malignancy than those in Group C and the prognosis of patients in the former groups was excellent. Group A and B tumors may be intracholecystic papillary-tubular neoplasms, a recently proposed new disease concept.

Some serrated polyps （SPs） are thought to be precursors of colorectal cancers. However, the endoscopic diagnosis of sessile serrated adenoma/polyps （SSA/Ps） has been reported to have a low accuracy. The aim of this study was to clarify the ability to distinguish between SSA/Ps and non-SSA/Ps by using mucosal crypt patterns combined with endoscopic findings. In total, 457 consecutive patients who underwent endoscopic resection for colorectal polyps at the Showa University Hospital from April 2007 to December 2010 were prospectively enrolled in this study. Before treatment, mucosal crypt patterns of the lesions were classified into three types （hyperplastic, adenomatous, and mixed pattern）. When the lesion had an adenomatous pattern with a cerebriform appearance or mixed pattern, it was diagnosed as a traditional serrated adenoma （TSA）. If the lesion had a hyperplastic pattern and was sized 6mm or more in the proximal colon or 10mm or more in the distal colon, it was diagnosed as an SSA/P by the endoscopist. We analyzed 1,151 colorectal polyps in this study. Endoscopically, 117 polyps were diagnosed as SSA/Ps or hyperplastic polyps （HPs）, 998 polyps were conventional adenomas, and 36 polyps were TSAs, with diagnostic accuracies of 94.7％, 94.1％, and 97.3％, respectively. Of the 117 polyps diagnosed as SSA/Ps or HPs, 59 lesions met our criteria for SSA/Ps, with a diagnostic accuracy of 70.9％. Our results indicate that the combination of mucosal crypt patterns and endoscopic findings may be useful for differentiating between SPs and non-SPs. However, additional specific endoscopic features of SSA/Ps are still needed.

The therapeutic effect found histologically after surgery following neoadjuvant chemotherapy (NAC) correlates with patient prognosis. Such correlations must consider the remaining invasive lesions as well as intra-ductal components and lymph node metastasis. To this end, we compared the residual cancer burden (RCB) index with the conventional method of judging the histopathological therapeutic effect. We also took into account the clinicopathological features of patients related to recurrence and prognosis by the RCB index. We studied 244 cases of primary breast cancer in 238 patients who had undergone surgery after NAC in Showa University Hospital from 2005 to 2014. We classified the cases into groups based on the Japanese Breast Cancer Society's criteria for evaluating the histological therapeutic effect and the RCB index. The cases were also analyzed in regard to various clinicopathological factors. The prognosis was evaluated by drawing recurrence-free survival curves using the Kaplan-Meier method, and the log rank test was used to test statistical significance. The RCB index was evaluated for cases of Grade 0–1b that had a certain degree of residual tumor tissue. Comparison of the recurrence-free survival rates in each of the RCB index groups indicated a significant correlation, although only for patients with some degree of residual malignancy even after chemotherapy. We conclude that the RCB index can be used for providing a more precise prediction of recurrence.

Additional file 1: Figure S1. (a) The graphics in abdominal plain CT and (b) the CECT equilibrium phase of case1 are shown. (c) The chest CT of case1 also revealed multiple lung nodules (arrow). (d) The lesions in the liver of case1 exhibited high signal intensity on axial T2WI. (e) The arterial dominant phase and (f) the hepatocellular phase in Gd-EOB-DTPA are shown. (g) In immunostaining (200×), a histological section of a hepatic specimen obtained via percutaneous liver needle biopsy in case 1 was positive for factor VIII. Figure S2. (a) The noncontrast CT of case2 revealed multiple hypodense liver nodules, with cystic lesions. (b) In the equilibrium phase of CECT, enhancement persisted inside the tumors. (c) T2WI showed multiple hyperintense liver nodules. (d) The size of liver tumors in the arterial dominant phase of CECT and (e) in the equilibrium phase have not increased when approximately 70 months has passes after the diagnosis was made. (f) In immunostaining (200×), a histological section of a hepatic specimen obtained via percutaneous liver needle biopsy in case 2 was positive for factor VIII. Figure S3. (a) The noncontrast CT of case3 revealed multiple hypodense liver nodules. (b) The graphics of abdominal CT in the arterial dominant phase and (c) in the equilibrium phase are shown. (d) The arterial dominant phase in Gd-EOB-DTPA is shown. (e) The size of liver tumors of case3 in the arterial dominant phase of CECT have not increased when approximately 49 months has passes after the diagnosis was made. (f) In immunostaining (200×), a histological section of a hepatic specimen obtained via percutaneous liver needle biopsy in case 3 was positive for factor VIII.