Impact of the COVID-19 pandemic on the incidence of surgical site infection after orthopaedic surgery: an interrupted time series analysis of the nationwide surveillance database in Japan

BACKGROUND

During the COVID-19 pandemic, hygiene awareness was increased in communities and hospitals. However, there is controversy regarding whether such circumstances affected the incidence of surgical site infections (SSIs) in the orthopaedic surgical field.

AIM

To examine the impact of the COVID-19 pandemic on the incidence of SSIs after orthopaedic surgery.

METHODS

The medical records of patients having undergone orthopaedic surgery were extracted from the nationwide surveillance database in Japan. The primary outcomes were the monthly incidences of total SSIs, deep or organ/space SSIs, and SSIs due to meticillin-resistant Staphylococcus aureus (MRSA). Interrupted time series analysis was conducted between pre-pandemic (January 2017 to March 2020) and pandemic (April 2020 to June 2021) periods.

RESULTS

A total of 309,341 operations were included. Interrupted time series analysis adjusted for seasonality showed no significant changes in the incidence of total SSIs (rate ratio 0.94 and 95% confidence interval 0.98-1.02), deep or organ/space SSIs (0.91, 0.72-1.15), or SSIs due to MRSA (1.07, 0.68-1.68) along with no remarkable slope changes in any parameter (1.00, 0.98-1.02; 1.00, 0.97-1.02; and 0.98, 0.93-1.03, respectively).

CONCLUSIONS

Awareness and measures against the COVID-19 pandemic did not markedly influence the incidence of total SSIs, deep or organ/space SSIs, or SSIs due to MRSA following orthopaedic surgery in Japan.

First Detection of Chimeric β-Lactamase CTX-M-64-Producing Salmonella Typhimurium from a Domestic Source in Japan

Salmonella enterica subsp. enterica serovar Typhimurium has recently emerged worldwide as a producer of extended-spectrum β-lactamase (ESBL). However, drug-resistant clinical isolates are rare in Japan. The common types of ESBLs found are the CTX-M-type β-lactamases, including novel β-lactamases such as CTX-M-64. CTX-M-64 has a chimeric structure comprising a combination of the CTX-M-1 and CTX-M-9 groups. In 2017, S. Typhimurium was isolated from stool, blood, and urine cultures of an 82-year-old man. Herein, we describe the discovery of a clinical isolate of S. Typhimurium in Japan. Antimicrobial susceptibility testing revealed that the isolate was resistant to third- and fourth-generation cephalosporins, including ceftazidime and monobactam. The minimum inhibitory concentrations of ceftazidime and ceftriaxone were restored by administration of clavulanic acid. Whole-genome sequencing analysis revealed that the isolate harbored the blaCTX-M-64 gene on an IncHI2/IncHI2A-type plasmid, with an assembly length of 174,477 bp. The genetic structure of the region surrounding the blaCTX-M-64 gene, ISKpn26-ΔISEcp1-blaCTX-M-64-orf477, was shared only with the chromosome sequence of S. Typhimurium detected in food-producing chickens in Guangdong, China. Although rare, S. Typhimurium can induce bloodstream infections and produce ESBL. To our knowledge, this is the first report of a CTX-M-64-producing Enterobacterales clinical isolate of domestic origin in Japan.

Antibiotic resistance and the presence of bla CfxA and bla CSP genes in β-lactamase-producing clinical Capnocytophaga isolates from a university hospital in Japan

Introduction . Capnocytophaga species are common inhabitants of the oral cavity and can be responsible for systemic diseases in immunocompromised patients with granulocytopenia. Furthermore, it has been reported that some clinical isolates of Capnocytophaga species produce extended-spectrum β-lactamases (ESBLs).Gap statement. Information is lacking about the types of β-lactamase genes possessed by Capnocytophaga spp. and the antimicrobial susceptibility of Capnocytophaga spp. possessing each β-lactamase gene.Aim. The aim of this study was to investigate the presence of β-lactamase genes in clinical strains of β-lactamase-producing Capnocytophaga species isolated from clinical samples acquired at Shinshu University Hospital and examine the antimicrobial susceptibility of those strains.Methodology. The β-lactamase-producing Capnocytophaga species (n=49) were obtained from clinical specimens. PCR assays were used to detect bla _CfxA, bla _CSP, bla _TEM, bla _CepA/CblA and transposon Tn4555 genes. Southern hybridization assays were used to detect bla _CfxA and bla _CSP. The minimum inhibitory concentration of some β-lactams was determined using the E-test method.Results. PCR analysis indicated that the bla _CfxA gene was present in 15 (30.6 %) and the bla _CSP gene in 35 (69.3 %) of the 49 Capnocytophaga strains investigated, . Both bla _CfxA and bla _CSP genes were detected in a Capnocytophaga gingivalis strain. The PCR results were confirmed by Southern hybridization assays. Transposon Tn4555 was only detected in Capnocytophaga spp. harbouring the bla _CfxA gene. All the β-lactamase-producing Capnocytophaga isolates were susceptible to ceftazidime-clavulanic acid, cefoxitin and imipenem. In contrast, most of the isolates were resistant to amoxicillin.Conclusions. The clinical isolates of Capnocytophaga spp. showed a high prevalence of the bla _CSP gene in Japan. The presence of the bla _CSP gene was distributed in Capnocytophaga sputigena as well as other Capnocytophaga spp. These results seem to suggest the dissemination of bla _CfxA and bla _CSP β-lactamase genes among Capnocytophaga species.

Isolated splenic Mycobacterium tuberculosis complex infection in an immunocompetent individual with FDG-PET positive mass

Tuberculosis, caused by Mycobacterium tuberculosis complex, is a leading cause of mortality in the world, and 15% of the patients may present with extrapulmonary diseases, including splenic lesion. However, isolated splenic infection with M. tuberculosis complex is very rare. A 19-year-old otherwise healthy woman presented with left flank pain, revealing FDG-avid nodules in the spleen. She did not have pulmonary lesions. Histopathology of splenectomized sample showed granuloma, and subsequent PCR revealed amplification of IS6110, a genetic sequence exclusively detected in M. tuberculosis complex. A wide range of differential diagnosis of isolated splenic lesion should include M. tuberculosis infection regardless of pulmonary involvement. An elective splenectomy may be mandatory in timely manner.

Detection of Acinetobacter pittii ST220 co-producing NDM-1 and OXA-820 carbapenemases from a hospital sink in a non-endemic country of NDM

OBJECTIVES

NDM-1 is by far one of the most commonly prevalent carbapenemases in Enterobacteriaceae and Acinetobacter baumannii. This study presented an Acinetobacter pittii (A. pittii) isolate co-harboring bla_NDM-1 and bla_OXA-820 from a university hospital sink, where New Delhi metallo-β-lactamase (NDM) producers have not been found in either patients or their environments.

METHODS

Whole-genome sequencing was performed on the HiSeq 4000 platform, and the reads were de novo assembled using the A5-miSeq Assembly pipeline. Annotation of the resulting scaffolds were performed by using the DDBJ Fast Annotation and Submission Tool (DFAST). The bla_NDM-1-carrying plasmid was determined.

RESULTS

The A. pittii ST220 strain SU1805 detected from a sink strainer in the treatment room was resistant to imipenem and meropenem. Antimicrobial resistance genes bla_NDM-1, bla_OXA-820, bla_ADC-43, and aphA6 were found in this strain. The bla_NDM-1 was found to be located downstream of an ISAba125 element on a plasmid pSU1805NDM with a size of 41,022 bp, and GC content of 38.3% harbouring 48 protein-coding genes. The aphA6 gene was also located upstream of the ISAba125 on the same plasmid. The A. pittii intrinsic bla_OXA-213-like gene bla_OXA-820 was located between fxsA and yncA genes in the chromosome. The strain also harboured biofilm-associated genes such as ompA, the csu operon and their regulating genes bfmRS.

CONCLUSION

This study described the first isolation of NDM-1-producing A. pittii in Japan, and highlighted the importance of proper implementation of measures against AMR for sink drainage systems, since NDM producers may have already been hidden in such environments in a non-endemic country of NDM.

Cecal Tumorigenesis in Aryl Hydrocarbon Receptor-Deficient Mice Depends on Cecum-Specific Mitogen-Activated Protein Kinase Pathway Activation and Inflammation

The aryl hydrocarbon receptor (AhR) is a transcription factor known as a dioxin receptor. Recently, Ahr^-/- mice were revealed to develop cecal tumors with inflammation and Wnt/β-catenin pathway activation. However, whether β-catenin degradation is AhR dependent remains unclear. To determine whether other signaling pathways function in Ahr^-/- cecal tumorigenesis, we investigated histologic characteristics of the tumors and cytokine/chemokine production in tumors and Ahr^-/- peritoneal macrophages. AhR expression was also assessed in human colorectal carcinomas. Of the 28 Ahr^-/- mice, 10 developed cecal lesions by 50 weeks of age, an incidence significantly lower than previously reported. Cecal lesions of Ahr^-/- mice developed from serrated hyperplasia to adenoma/dysplasia-like neoplasia with enhanced proliferation. Macrophage and neutrophil infiltration into the lesions was also observed early in serrated hyperplasia, although adjacent mucosa was devoid of inflammation. Il1b, Il6, Ccl2, and Cxcl5 were up-regulated at lesion sites, whereas only IL-6 production increased in Ahr^-/- peritoneal macrophages after lipopolysaccharide + ATP stimulation. Neither Myc (alias c-myc) up-regulation nor β-catenin nuclear translocation was observed, unlike previously reported. Interestingly, enhanced phosphorylation of extracellular signal-regulated kinase, Src, and epidermal growth factor receptor and Amphiregulin up-regulation at Ahr^-/- lesion sites were detected. In human serrated lesions, however, AhR expression in epithelial cells was up-regulated despite morphologic similarity to Ahr^-/- cecal lesions. Our results suggest novel mechanisms underlying Ahr^-/- cecal tumorigenesis, depending primarily on cecum-specific mitogen-activated protein kinase pathway activation and inflammation.

A case of cervical subcutaneous abscess due to Bordetella hinzii

We present a case of subcutaneous infection caused by Bordetella hinzii in a healthy male. The isolate was successfully identified by gyrB gene sequencing. B. hinzii cannot be distinctively identified using 16S rRNA gene sequencing or by biochemical methods. The number of cases infected with B. hinzii might be underestimated owing to the difficulty in accurate identification, which can be achieved by gyrB gene sequencing to gain knowledge about the species.

Abstract P1-03-02: ASCO/CAP human epidermal growth factor receptor-2 (HER2) in situ hybridization (ISH) categories evaluated by quantitative HER2 protein diagnostic methodologies: A comparative analysis

Background: In 2013, the ASCO/CAP consensus panel published updated guidelines for HER2 testing in breast cancer that modified the definition of HER2 amplification by in situ hybridization (ISH), creating five new prognostic categories (group 1: classic amplified, group 2: monosomy, group 3: co-amplified (polysomy), group 4: equivocal, and group 5: classic non-amplified). Patients determined to be ISH amplified, were considered eligible for HER2-directed therapy. Concern over whether patients from non-classic groups 2-4 would benefit from treatment has led to the recent publication of the 2018 HER2 focused update. This update has modified the criteria for interpreting these ISH categories, recommending that the final diagnosis take into consideration a combination of HER2 immunohistochemistry (IHC) and ISH results. With increased emphasis on the HER2 protein assessment, it has prompted us to quantitatively examine HER2 protein expression in the ISH categories, using two different novel technologies. Materials & Methods: A cohort of 170 cases (URMC) and 102 cases (PSHMC) of invasive breast cancers, which had previously undergone HER2 IHC and ISH testing, were selected for this study. Cases were sorted and categorized into the HER2 ISH categories defined by ASCO/CAP. HER2 protein expression was quantitatively measured in the URMC and PSHMC cohorts using a novel immunodetection methodology (streptavidin-coated Phosphor-Integrated Dot (PID) fluorescent nanoparticles), and a novel dual-antibody, proximity-binding immunoassay (HERmark® Breast Cancer Assay, Monogram Biosciences, South San Francisco, California), respectively. HER2 protein expression was compared to the HER2 FISH and IHC results by ASCO/CAP category. Results: Cases in group 1 had a significantly (p < 0.01) higher average PID/cell and HERmark compared to cases in groups 2-5 (Table 1). Cases in groups 2-4 showed lower quantitative levels of HER2 protein expression, similar to the classic non-amplified cases (group 5). Group 1 was further divided into three subgroups (Table 2): Group A - ISH high-level amplified (ratio > 2, HER2 > 6, CEP17 < 2.7), Group B - amplified with elevated CEP17 (ratio > 2, CEP17 > 2.7), and Group C - low-level amplified (ratio > 2, HER2 > 4 and < 6). Group A and B had a significantly (p < 0.01) higher average PID/cell and HERmark compared to Group C. Group C was more comparable to cases in groups 2-5 (Table 1). Conclusion: Our results suggest that quantitative assessment of HER2 protein expression may help to further classify cases for HER2 status for targeted therapy, supporting the 2018 ASCO/CAP recommendation that non-classic ISH results might be resolved by evaluating protein expression. Follow up studies with a larger patient cohort and dual quantitative assessment are warranted.

Average PID/cell and HERmark in ASCO category groupsASCO category groupN (URMC)PID/cell (URMC)*N (PSHMC)HERmark (PSHMC)*18888.07761.521011.20N/A32016.0213.84238.5315.95296.3208.3*averageTable 2:Average PID/cell and HERmark in subgroups of Group 1SubgroupN (URMC)PID/cell (URMC)*N (PSHMC)HERmark (PSHMC)*A24157.66465.7B34101.61044.1C3016.9329.8*average

Citation Format: Buscaglia B, Turner B, Goda H, Huang W, Leitzel K, Natori T, Nakano Y, Okada H, Sperinde J, Ali S, Vasekar M, D'Aguiar M, McMahon L, Henry J, Lipton A, Hicks D. ASCO/CAP human epidermal growth factor receptor-2 (HER2) in situ hybridization (ISH) categories evaluated by quantitative HER2 protein diagnostic methodologies: A comparative analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-03-02.

Characterization of clinically isolated thymidine-dependent small-colony variants of Escherichia coli producing extended-spectrum β-lactamase

PURPOSE

Thymidine-dependent small-colony variants (TD-SCVs) are difficult to detect or test for antimicrobial susceptibility. We investigated the characteristics of clonal TD-SCVs of Escherichia coli, both with and without blaCTX-M-3, isolated from a patient.

METHODOLOGY

Mutation in the thyA gene was analysed by sequencing, and morphological abnormalities in the colonies and cells of the isolates were examined. Additionally, conjugational transfer experiments were performed to prove the horizontal transferability of plasmids harbouring resistance genes.

RESULTS

The TD-SCVs contained a single nucleotide substitution in the thyA gene, c.62G>A, corresponding to p.Arg21His. Morphologically, their colonies were more translucent and flattened than those of the wild-type strain. In addition, cells of the TD-SCVs were swollen and elongated, sometimes with abnormal and incomplete divisions; a large amount of cell debris was also observed. Changing c.62G>A back to the wild-type sequence reversed these abnormalities. Conjugational transfer experiments showed that the TD-SCV of E. coli with blaCTX-M-3 failed to transfer blaCTX-M-3 to E. coli CSH2. However, the TD-SCV of E. coli without blaCTX-M-3 experimentally received the plasmid encoding blaSHV-18 from Klebsiella pneumoniae ATCC 700603 and transferred it to E. coli CSH2.

CONCLUSION

Mutation in the thyA gene causes morphological abnormalities in the colonies and cells of E. coli, as well as inducing thymidine auxotrophy. In addition, TD-SCVs horizontally transmit plasmids encoding resistance genes. It is important to detect TD-SCVs based on their characteristics because they serve as reservoirs of transferable antibiotic resistance plasmids.

Phylogenetics of family Enterobacteriaceae and proposal to reclassify Escherichia hermannii and Salmonella subterranea as Atlantibacter hermannii and Atlantibacter subterranea gen. nov., comb. nov

Multilocus sequence analysis based on hypervariable housekeeping proteins was utilized to differentiate closely related species in the family Enterobacteriaceae. Of 150 housekeeping proteins, the top 10 hypervariable proteins were selected and concatenated to obtain distance data. Distances between concatenated proteins within the family were 0.9-41.2%, whereas the 16S rRNA and atpD-gyrB-infB-rpoB concatenated sequence (4MLSA) distances were 0.8-6.0% and 0.9-22.1%, respectively. These data indicate that phylogenetic analysis by concatenation of hypervariable proteins is a powerful tool for discriminating species in the family Enterobacteriaceae. To confirm the discriminatory power of the 10 chosen concatenated hypervariable proteins (C10HKP), phylogenetic trees based on C10HKP, 4MLSA, and the 16S rRNA gene were constructed. Comparison of average bootstrap values among C10HKP, 4MLSA and 16S rRNA genes indicated that the C10HKP tree was the most reliable. Location via the C10HKP tree was consistent with existing assignments for almost all species in the family Enterobacteriaceae. However, the C10HKP tree suggested that several species (including Enterobacter massiliensis, Escherichia vulneris, Escherichia hermannii, and Salmonella subterranea) should be reassigned to different clusters than those defined in previous analyses. Furthermore, E. hermannii and S. subterranea appeared to fall onto a branch independent from those occupied by the other Enterobacteriaceae. Therefore, we propose Atlantibacter gen. nov., such that E. hermannii and S. subterranea would be transferred to genus Atlantibacter as Atlantibacter hermannii, comb. nov. and Atlantibacter subterranea. comb. nov., respectively.

Carotid plaque characterization using 3D T1-weighted MR imaging with histopathologic validation: a comparison with 2D technique

BACKGROUND AND PURPOSE

3D FSE T1WI has recently been used for carotid plaque imaging, given the potential advantages in contrast and spatial resolutions. However, its diagnostic performance remains unclear. Hence, we compared the ability of this technique to readily assess plaque characteristics with that of conventional images and validated the results with histologic classification.

MATERIALS AND METHODS

We prospectively examined 34 patients with carotid stenosis who underwent carotid endarterectomy by using 1.5T scanners and obtained 3D-FSE T1WI and 2D spin-echo T1WI scans. After generating reformatted images obtained from the 3D-FSE T1-weighted images, we calculated the contrast ratios for the plaques and the adjacent muscles and compared these findings with the pathologic classifications.

RESULTS

Carotid plaques were histologically classified as types VII, VIII, IV-V, or VI. With 3D-FSE T1WI, the range of contrast ratios for each classification was the following: 0.94-0.97 (median, 0.95), 0.95-1.29 (median, 1.10), 1.33-1.54 (median, 1.42), and 1.53-2.12 (median, 1.80), respectively. With 2D imaging, the range of contrast ratios for each classification was the following: 0.79-1.02 (median, 0.90), 0.88-1.19 (median, 1.01), 1.17-1.46 (median, 1.23), and 1.55-2.51 (median, 2.07), respectively. Results were significantly different among the 4 groups (P < .001). Sensitivity and specificity for discriminating vulnerable plaques (IV-VI) from stable plaques (VII, VIII) were both 100% for the 3D technique and 100% and 91%, respectively, for the 2D technique.

CONCLUSIONS

3D-FSE T1WI accurately characterizes intraplaque components of the carotid artery, with excellent sensitivity and specificity compared with those of 2D-T1WI.

Predicting carotid plaque characteristics using quantitative color-coded T1-weighted MR plaque imaging: correlation with carotid endarterectomy specimens

BACKGROUND AND PURPOSE

MR plaque imaging is used to evaluate the risk of embolic complications during carotid endarterectomy and carotid artery stent placement. However, its performance for characterizing intraplaque components has varied across studies and is generally suboptimal. Hence, we correlated MR imaging results with histologic findings to determine whether a combination of high-contrast T1-weighted imaging and quantitative image analysis could readily determine plaque characteristics.

MATERIALS AND METHODS

We prospectively examined 40 consecutive patients before carotid endarterectomy by using a 1.5T scanner and axial T1-weighted spin-echo images under optimized scanning conditions. The percentage areas of intraplaque fibrous tissue, lipid/necrosis, and hemorrhage were calculated automatically by using the software with previously reported cutoff values and were compared with those of the specimens. The thickness of the fibrous cap was also measured manually.

RESULTS

The percentage areas of fibrous, lipid/necrotic, and hemorrhagic components were 5.7%-98.7%, 1.3%-65.7%, and 0%-82.0%, respectively, as determined by the MR images, whereas the corresponding values were 4.8%-92.3%, 7.0%-93.8%, and 0%-70.4%, respectively, as determined by histologic examination. Significant positive correlation and agreement were observed between MR images and histologic specimens (r = 0.92, 0.79, and 0.92; intraclass correlation coefficients = 0.91, 0.67, and 0.89; respectively). Thickness of the fibrous caps on MR images (0.21-0.87 mm) and in the specimens (0.14-0.83 mm) also showed positive correlation and agreement (r = 0.61, intraclass correlation coefficient = 0.59).

CONCLUSIONS

Quantitative analysis of high-contrast T1-weighted images can accurately evaluate the composition of carotid plaques in carotid endarterectomy candidates.

Enhancement of denitrification in a down-flow hanging sponge reactor by effluent recirculation

A down-flow hanging sponge reactor, constructed by connecting three identical units in series, was applied to the treatment of artificial wastewater containing phenol and ammonia under high salinity conditions (10.9 g-Cl(-)/L). The theoretical hydraulic retention time (HRT) of each unit was 4 h (total HRT = 12 h). To enhance denitrification by effluent recirculation, the effluent recirculation ratio was increased in increments ranging from 0.0 to 2.0. The concentration of total ammonia nitrogen (TAN), NO2-N, and NO3-N in the final effluent as a proportion of the TAN in the influent was determined to calculate the unrecovered, or denitrification, proportion. The denitrification proportion of the reactor was equivalent to 19.1 ± 14.1% with no effluent recirculation; however, this was increased to 58.6 ± 6.2% when the effluent recirculation ratio was increased to 1.5. Further increasing the effluent recirculation ratio to 2.0 resulted in a decrease in the denitrification proportion to 50.9 ± 9.3%. Activity assays of nitrification and denitrification, as well as 16S rRNA gene sequence analysis, revealed that denitrification occurred primarily in the upper sections of the reactor, while nitrification increased in the lower sections of the reactor. Gene sequence analysis revealed that denitrification by Azoarcus-like species using phenol as an electron donor was dominant.

Abstract PD06-02: Standardized Assessment of Ki-67 Using Virtual Slides and Automated Analyzer for Breast Cancer Patients: Comparison of Automated and Central/Local Pathology Assessment

Background: Ki-67 is useful in determining the effect of hormonal therapy and also as a prognostic factor. However, the method for its evaluation has not been standardized, and the results vary depending on the assessment by pathologists. We reported that the discordance rate of Ki-67 in preoperative core needle biopsy and the surgical specimens was higher than that of other biological markers, and this was considered to be due to the discrepancies in the evaluation methods (SABCS 2011). In this report, we reviewed the possibility of introducing an automated analyzer by comparing the diagnosis made by local pathologists and reassessment by central review to standardize the evaluation method for Ki-67.

Subjects and Method: Of the 354 cases of primary breast cancer that had their first operation from October 2008 to March 2012, 225 cases that had preoperative core needle biopsy at Tokyo-West Tokushukai Hospital were selected as the subjects of this study. Cases with ductal carcinoma in situ (DCIS) and cases with neoadjuvant chemotherapy were excluded. A cut-off value of 20% was used for Ki-67 positive criteria. The concordance rates of estrogen receptors (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), and Ki-67 by local pathologists were reviewed, and in cases of non-matching Ki-67, tumor diameter (≈ heterogeneity) and operative method (≈ condition of formalin fixation) were studied. Next, non-matching cases (∼ to October 2011) were reassessed both by central review and by an automated analyzer (Ventana Digital Pathology) using virtual slides, and the results were studied and compared with the evaluation by local pathologists. The Wilcoxon-t test was used to review the p value for statistical analysis. Parameters such as tumor diameter, operative method were analyzed by χ2 analysis.

Results: The concordance rate of Ki-67 in preoperative core needle biopsy and surgical specimens was 76.9% in 225 cases of local pathology assessment from October 2008 to March 2012. This rate was significantly lower (p &lt; 0.001) than that of ER (95.6%), PgR (88.0%), and HER2 (91.5%). In non-matching cases, no difference was observed in tumor diameter and operative method. Reassessment of the 39 cases of non-matching Ki-67 to October 2011 using central review and an automated analyzer resulted in matching 27 cases (94.8%) and 32 (96.3%) out of 39 cases, respectively.

Conclusion: The concordance rate of Ki-67 in preoperative core needle biopsy and surgical specimens was lower compared with other biological markers. However, they were nearly equal with reassessment using central review and an automated analyzer. Clinical application of Ki-67 and its standardization are challenging due to variable counting methods and measurement sites. Conducting central reviews in general clinical facilities is difficult, but introducing an automated analyzer with a Ki-67 labeling index is shown to achieve that goal.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD06-02.

IL-12 Production Induced by Agaricus blazei Fraction H (ABH) Involves Toll-like Receptor (TLR)

Agaricus blazei Murill is an edible fungus used in traditional medicine, which has various well-documented medicinal properties. In the present study, we investigated the effects of hemicellulase-derived mycelia extract (Agaricus blazei fraction H: ABH) on the immune system. First, we examined the cytokine-inducing activity of ABH on human peripheral mononuclear cells (PBMC). The results indicated that ABH induced expression of IL-12, a cytokine known to be a critical regulator of cellular immune responses. Flow cytometric analysis demonstrated the induction of IL-12 production by the CD14-positive cell population, consisting of monocytes/macrophages (Mo/Mphi). Furthermore, the elimination of Mo/Mphi attenuated IL-12 production in PBMC. ABH-induced IL-12 production was inhibited by anti-CD14 and anti-TLR4 antibodies but not by anti-TLR2 antibody. The activity of ABH was not inhibited by polymyxin B, while the activity of lipopolysaccharide used as a reference was inhibited. Oral administration of ABH enhanced natural killer (NK) activity in the spleen. These findings suggest that ABH activated Mo/Mphi in a manner dependent on CD14/TLR4 and NK activity.

Glycolipid antigen processing for presentation by CD1d molecules

The requirement for processing glycolipid antigens in T cell recognition was examined with mouse CD1d-mediated responses to glycosphingolipids (GSLs). Although some disaccharide GSL antigens can be recognized without processing, the responses to three other antigens, including the disaccharide GSL Gal(alpha1-->2)GalCer (Gal, galactose; GalCer, galactosylceramide), required removal of the terminal sugars to permit interaction with the T cell receptor. A lysosomal enzyme, alpha-galactosidase A, was responsible for the processing of Gal(alpha1-->2)GalCer to generate the antigenic monosaccharide epitope. These data demonstrate a carbohydrate antigen processing system analogous to that used for peptides and an ability of T cells to recognize processed fragments of complex glycolipids.

Examination of the pathogenesis of diabetic nephropathy in OLETF rats

We conducted protein loading to examine the progression and pathogenesis of diabetic nephropathy. For this experiment, male OLETF, LETO, F344 and BN rats were used. This experiment was performed on rats between 5 and 30 weeks of age. Examination parameters included body weight, food intake, oral glucose tolerance test (OGTT), urinary protein level (UP), urinary albumin level (UA), glomerular filtration rate (GFR), kidney weights, light microscopy (LM) and electron microscopy (EM). In the protein-loaded OLETF group, the UP level was markedly increased 20 weeks or more after birth. In OLETF control group, GFR were higher than those in other strains. Glomerular hypertrophy and kidney weights were markedly increased in protein-loaded groups in OLETF rats. Thirty weeks after birth, EM showed that the number of polyethyleneimine (PEI) of the glomerular basement membrane (GBM) in protein-loaded OLETF group was significantly decreased compared to that in control group. These changes in OLETF rats were more marked in the protein-loaded group than those in the control group. LM showed that the number of exudative lesions with fibrin-cap in the protein-loaded OLETF group was significantly increased than those in control group. In OLETF rats, protein loading caused deterioration of nephropathy at 30 weeks of age. Therefore, it was demonstrated that not only blood sugar control but also protein intake factors play important roles in the deterioration of nephropathy in OLETF rats.

Structure-activity relationship and conformational analysis of monoglycosylceramides on the syngeneic mixed leukocyte reaction

We examined effects of alpha-, beta-galactosylceramides (CalCers) and alpha-, beta-glucosylceramides (GlcCers) on the syngeneic mixed leukocyte reaction (MLR) using spleen cells (responder cells) and dendritic cells (DC, stimulator cells). The DC pretreated with these alpha-monoglycosylceramides markedly stimulated the proliferation of spleen cells, in contrast to the little stimulatory effects produced by the DC pretreated with the corresponding beta-anomers. In addition, when we compared the effects of alpha-GalCer derivatives on the syngeneic MLR, it appeared that the 2"- and 3-hydroxyl groups in alpha-GalCers play a critical role in their stimulation of the MLR response. Based on these results, we performed a computer-aided molecular modeling study, and found that the orientations of the 2"-, 4"- and 3-hydroxyl groups common to alpha-GalCer and alpha-GlcCer are not accessible to those of inactive monoglycosyleeramides such as beta-GalCer. These results suggest that there might be a receptor-like site for alpha-monoglycosylceramides on the cells which are involved in the MLR response.

Effects of alpha- and beta-galactosylated C2-ceramides on the immune system

In contrast to the immunosuppressive effects of C2-ceramide (C2-Cer), alpha-galactosylceramides with ceramides having more than 10 carbons in fatty acid chains have immunostimulatory activities. We therefore synthesized alpha- and beta-galactosylated C2-Cers in order to examine their effects on the immune system. beta-Galactosylated C2-Cer and C2-Cer suppressed the allogeneic mixed leukocyte reaction (MLR) responses, but alpha-galactosylated C2-Cer stimulated the MLR response.

Immunostimulatory activities of monoglycosylated alpha-D-pyranosylceramides

We compared the immunostimulatory effects of chemically synthesized alpha-galactosylceramides (alpha-GalCers), alpha-glucosylceramides (alpha-GluCers), 6"-monoglycosylated alpha-GalCer and 6"- or 4"-monoglycosylated alpha-GluCer and made the following observations: (1) the length of the fatty acid side chain in the ceramide portions greatly affects the immunostimulatory effects of alpha-GalCers and alpha-GluCers; (2) the configuration of the 4"-hydroxyl group of the inner pyranose moiety plays an important role in the immunostimulatory effects of monoglycosylated alpha-D-pyranosylceramides; (3) the free 4"-hydroxyl group of the inner pyranose of monoglycosylated alpha-D-pyranosylceramides plays a more important role in their immunostimulatory effects than the free 6"-hydroxyl group.

[Development of KRN7000, derived from agelasphin produced by Okinawan sponge]

New glycosphingolipids, named agelasphins, have been isolated as antitumoral compounds from an extract of a marine sponge, Agelas mauritianus. The absolute configurations of agelasphins were elucidated by the total synthesis. Various analogues of agelasphins were also synthesized and the relationship between their structures and biological activities was examined using an MLR assay. From the results, KRN7000, (2S,3S,4R)-1-O-(alpha-D- galactopyranosyl)-2-(N-hexacosanoylamino)-1,3,4-octadecanetriol , was selected as a candidate for clinical application. KRN7000 markedly stimulated lymphocytic proliferation in allogeneic MLR, and showed potent tumor growth inhibitory activities in B16-bearing mice and strongly inhibited tumor metastasis, suggesting that KRN7000 is a potent biological response modifier. These biological effects were exerted by the activation of dendritic cells by KRN7000.

Immunostimulatory activities of mono- or diglycosylated alpha-galactosylceramides

We examined the effects of 2"- or 3"-monoglycosylated alpha-galactosylceramides (alpha-GalCers) and 2",3"-diglycosylated alpha-GalCers on allogeneic MLR and the proliferation of murine spleen cells. It was found that their ceramide portions greatly affect their immunostimulatory activities, and that the 3"-hydroxyl group plays a more important role in the immunostimulatory effects of alpha-GalCer derivatives than the 2"-hydroxyl group.

RT1.P, rat class Ib genes related to mouse TL: evidence that CD1 molecules but not authentic TL antigens are expressed by rat thymus

CD1 and TL were once thought to be genetic homologues because of their thymus-specific expression. We investigated their equivalents in the rat to clarify whether their structure and pattern of expression are conserved in rodents. Two rat class Ib genes, containing 3' sequences very similar to mouse TL, were identified and designated RT1.P. Neither of them, however, can encode ordinary class I molecules due to the accumulation of harmful mutations in the 5' regions that are unique to RT1.P, while the 3' TL-like regions still retain protein-coding capacity. Comparison of the structural organization of three types of TL family genes, which include mouse T3/T18-encoding TL antigens, mouse T1/T16, and rat RT1. P1/P2 pseudogenes, revealed the presence of a clear demarcation between the type-specific and TL-specific sequences at intron 3. This finding suggests that recombination plays an important role in creating the TL family genes in rodents. Characteristic features of TL, such as a low level of polymorphism and linkage to the major histocompatibility complex, were also observed in the rat. On the other hand, rat CD1 molecules were expressed at a high level on the surface of thymocytes. Absence of authentic TL antigens and thymic expression of CD1d molecules in the rat suggest the plasticity and conservation of class Ib genes in rodent evolution. Functions of TL may be substituted with CD1 or other class Ib molecules expressed by rat thymus.

Relationships between diet control and the development of spontaneous type II diabetes and diabetic nephropathy in OLETF rats

The effect of a 30% restricted diet on the development of diabetes and diabetic nephropathy was examined using the Otsuka Long Evans Tokushima Fatty (OLETF) rat which develops non-insulin-dependent diabetes mellitus (NIDDM) spontaneously after 25-30 weeks of age. The first experimental group that received 30% restricted feeding from six to 80 weeks old, showed complete suppression of spontaneous diabetes up to 40 weeks of age and showed milder histopathological change of pancreatic islets, that those of the control group. The second group which received 30% restricted feeding during 30-80 weeks, showed a gradual decrease in clinical diabetes with age, even though they had already developed diabetes at 25 weeks. In both groups, levels of urinary protein content appeared to decrease, compared with that in control rats, although a gradual increase of urinary protein was observed with age. Histopathologically, glomerular damages were slight to mild in both groups. However, no improvement in nephrotic complication was observed for the group which received a 30% restricted feeding after 70 weeks of age. These results clearly show that the balanced-control diet, given at a 30% restricted feeding level and at an early phase, is effective in the prevention or improvement of NIDDM and nephrotic complications. Diet therapy after 70 weeks of age, however, had little or no effect.

A diabetogenic gene, ODB2, identified on chromosome 14 of the OLETF rat and its synergistic action with ODB1

Genetic analysis of diabetogenic genes involved in developing spontaneous diabetes of NIDDM type in the OLETF rat was performed in (OLETF female X B N male)F2 and (OLETF female X BN male)F1 female X OLETF male backcross male offspring. In the F2 and/or backcross offspring, a high frequency of diabetes was found to be associated with a coat color gene, H (hooded). Since it is know that H gene is located on chromosome 14. an attempt was made to examine the linkage association of the gene responsible for elevating plasma glucose with various microsatellite markers of chromosome 14 in male F2 and/or backcross offspring. The results show that a high linkage exists with a microsatellite marker, D14Mit4 (LOD > 2). The gene was designated Odb2. It was also found that both genes, Odb1 which was previously found on chromosome X, and homozygous Odh2 are required to cause elevated plasma glucose in OGTT.

Enhancing effects of agelasphin-11 on natural killer cell activities of normal and tumor-bearing mice

Agelasphin-11 (AGL-11), a novel alpha-galactosylceramide isolated from an extract of a marine sponge, Agelas mauritianus, markedly prolonged the life span of mice intraperitoneally inoculated with B16 cells. Since AGL-11 did not show any direct cytotoxic activity against B16 cells, this compound is considered to be a biological response modifier (BRM). We focused on the enhancing effect of this compound on in vivo natural killer (NK) cell activity because several BRMs have already been determined to enhance the in vivo natural killer (NK) cell activity. When we evaluated the enhancing activity of AGL-11 using normal mice, AGL-11 enhanced in vivo NK cell activity more potently than Poly I:C, which is a positive control. In addition, we examined the effect of this compound on the NK cell activity of tumor-bearing mice, and found that AGL-11 recovers the reduced NK cell activity in a tumor-bearing condition to a higher level than that of normal mice. These results suggest that AGL-11 shows antitumor activity by the activation of antitumor effector cells such as NK cells.

Structure-activity relationship of alpha-galactosylceramides against B16-bearing mice

Agelasphin-9b, (2S,3S,4R)-1-O-(alpha-D-galactopyranosyl)-16-methyl-2- [N-((R)-2- hydroxytetracosanoyl)-amino]- 1,3,4-heptadecanetriol, is a potent antitumor agent isolated from the marine sponge Agelas mauritianus. Various analogues of agelasphin-9b (a lead compound) were synthesized, and the relationship between their structures and biological activities was examined using several assay systems. From the results, KRN7000, (2S,3S,4R)-1-O-(alpha-D- galactopyranosyl)-2-(N-hexacosanoylamino)-1,3,4-octadecanetriol , was selected as a candidate for clinical application.

A diabetogenic gene (ODB-1) assigned to the X-chromosome in OLETF rats

The Otsuka Long-Evans Tokushima Fatty (OLETF) rat develops hyperglycemia, hyperinsulinemia and mild obesity, features that closely resemble those in human non-insulin-dependent diabetes mellitus (NIDDM). Here, we report a gene involved in the development of diabetes in OLETF rats. Segregation studies using OLETF and an unrelated strain, F344 showed that no diabetes was observed in F1 progeny and less than 12.5% of the F2 progeny developed diabetes, suggesting that multiple recessive genes are involved in the disease. Interestingly, diabetes was observed in approximately 40% of (OLETF female x LETO male) F1 male rats, whereas less than 4% of males were diabetic in the reverse F1 mating. This suggested that the LETO rat which has been established from the same original colony as the OLETF rat shares some, but not all, diabetogenic genes with the OLETF, and that one of the responsible genes locates on the X-chromosome. Linkage study using (OLETF female x F344 male)F2 progeny has confirmed that one of the diabetogenic loci in the OLETF rats locates on the X-chromosome 14 cM distant from the AR gene (LOD = 2.598) and has been designated as ODB-1.

OLETF (Otsuka Long-Evans Tokushima Fatty) rat: a new NIDDM rat strain

The characteristic features of OLETF rats are: (1) late onset of hyperglycemia (after 18 weeks of age); (2) a chronic course of disease; (3) mild obesity; (4) clinical onset of diabetes mellitus (DM) mostly in males; (5) hereditary trait: (a) multiple recessive genes are involved in the induction of DM; (b) rat MHC, RT1 has no diabetogenic effect; (c) control strain, LETO appears to share some of diabetogenic genes with OLETF rats; (d) female OLETF rats also carry diabetogenic genes; and (e) one of the diabetogenic genes, designated as odb-1, is transmitted linked with the X-chromosome of OLETF rats, however testosterone is an important factor involved in developing diabetes; (6) the changes of pancreatic islets can be classified into three stages: (1) an early stage (at less than 9 weeks of age) mild lymphocyte infiltration; (2) a hyperplastic stage (10-40 weeks of age); hyperplastic change and fibrosis in or around islets; (3) a final stage (at more than 40 weeks of age) showing atrophy of islets; (7) diabetic nephropathy; (a) diffuse glomerulosclerosis; (b) nodular lesion (thickening of basement membranes, mesangial proliferation, fibrin cap). These clinical and pathologic features of disease in OLETF rats resemble those of human NIDDM.

[Study on the establishment of erythropoietin producing human renal cell carcinoma heterotransplanted to nude mice]

We conducted the establishment of erythropoietin (Epo) producing human renal cell carcinoma heterotransplanted in nude mice (JRC 901) and analysed its histopathological and biological characteristics. Regarding to histopathological analysis, JRC 901 showed renal cell carcinoma with granular cell subtype, alveolar pattern and grade II malignancy. In an effort to the electron microscopic analysis, JRC 901 showed renal cell carcinoma with microvilli, rich lipid droplets and mitochondria. As to the tumour doubling time, the JRC 901 showed 14.81 days in a logarithmic phase. As to the karyotype, the JRC 901 showed human, 46, XY, -11, 8p+, 17q-, +mar. After tumour inoculation to the nude mice, the blood level of Epo increased at 5 weeks, and its level reached at 485.2 mU/ml at 12 weeks after tumour inoculation. Furthermore, immunohistochemical staining using anti-Epo showed positive staining within cytoplasm of JRC 901. Moreover, the production of Epo was observed in the level of mRNA (264 bp) using RT-PCR method. We conclude that the JRC 901 is a human renal cell carcinoma heterotransplantable to nude mice and this tumour produce the Epo after tumour inoculation to nude mice.

Interleukin-5 preferentially recruits eosinophils from vessels in nasal mucosa

Interleukin-5 (IL-5), initially described as possessing eosinophil differentiating and proliferating activity, has now been shown to exert its effects on mature eosinophils. To investigate the ability of recombinant human IL-5 (rhIL-5) to cause the migration of eosinophils in the nasal mucosa in vivo, we compared the eosinophil counts in nasal mucosa without and after the nasal application of rhIL-5. In addition, the percentages of eosinophils in leukocytes within the vascular lumens in the nasal mucosa were counted to determine whether IL-5 recruited eosinophils from the vessels. The total number of eosinophils in both the epithelium and lamina propria, as well as the percentage of eosinophils in leukocytes within the lumens of vessels in the nasal mucosa after the application of IL-5, were higher than those in control nasal mucosa. Conversely, neither the number of neutrophils in the nasal mucosa nor the percentages of neutrophils in vessels differed between the two groups of nasal mucosa. The results strongly suggest that IL-5 preferentially recruits eosinophils from vessels into the lamina propria.