Central Residues in Prion Protein PrPC Are Crucial for Its Conversion into the Pathogenic Isoform

Conformational conversion of the cellular prion protein, PrP^C, into the amyloidogenic isoform, PrP^Sc, is a key pathogenic event in prion diseases. However, the conversion mechanism remains to be elucidated. Here, we generated Tg(PrPΔ91-106)-8545/Prnp^0/0 mice, which overexpress mouse PrP lacking residues 91-106. We showed that none of the mice became sick after intracerebral inoculation with RML, 22L, and FK-1 prion strains nor accumulated PrP^ScΔ91-106 in their brains except for a small amount of PrP^ScΔ91-106 detected in one 22L-inoculated mouse. However, they developed disease around 85 days after inoculation with bovine spongiform encephalopathy (BSE) prions with PrP^ScΔ91-106 in their brains. These results suggest that residues 91-106 are important for PrP^C conversion into PrP^Sc in infection with RML, 22L, and FK-1 prions but not BSE prions. We then narrowed down the residues 91-106 by transducing various PrP deletional mutants into RML- and 22L-infected cells and identified that PrP mutants lacking residues 97-99 failed to convert into PrP^Sc in these cells. Our in vitro conversion assay also showed that RML, 22L, and FK-1 prions did not convert PrPΔ97-99 into PrP^ScΔ97-99, but BSE prions did. We further found that PrP mutants with proline residues at positions 97 to 99 or charged residues at positions 97 and 99 completely or almost completely lost their converting activity into PrP^Sc in RML- and 22L-infected cells. These results suggest that the structurally flexible and noncharged residues 97-99 could be important for PrP^C conversion into PrP^Sc following infection with RML, 22L, and FK-1 prions but not BSE prions.

Mesh fixation techniques for inguinal hernia repair: an overview of systematic reviews of randomised controlled trials

PURPOSE

Inguinal hernia repair using surgical mesh is a very common surgical operation. Currently, there is no consensus on the best technique for mesh fixation. We conducted an overview of existing systematic reviews (SRs) of randomised controlled trials to compare the risk of chronic pain and recurrence following open and laparoscopic inguinal hernia repairs using various mesh fixation techniques.

METHODS

We searched major electronic databases in April 2020 and assessed the methodological quality of identified reviews using the AMSTAR-2 tool.

RESULTS

We identified 20 SRs of variable quality assessing suture, self-gripping, glue, and mechanical fixation. Across reviews, the risk of chronic pain after open mesh repair was lower with glue fixation than with suture and comparable between self-gripping and suture. Incidence of chronic pain was lower with glue fixation than with mechanical fixation in laparoscopic repairs. There were no significant differences in recurrence rates between fixation techniques in open and laparoscopic mesh repairs, although fewer recurrences were reported with suture. Many reviews reported wide confidence intervals around summary estimates. Despite no clear evidence of differences among techniques, two network meta-analyses (one assessing open repairs and one laparoscopic repairs) ranked glue fixation as the best treatment for reducing pain and suture for reducing the risk of recurrence.

CONCLUSION

Glue fixation may be effective in reducing the incidence of chronic pain without increasing the risk of recurrence. Future research should consider both the effectiveness and cost-effectiveness of fixation techniques alongside the type of mesh and the size and location of the hernia defect.

Extended application of the rapid post-mortem test kit for bovine spongiform encephalopathy to chronic wasting disease

Chronic wasting disease (CWD) is a prion disease affecting cervid species primarily in the United States of America and Canada; however, it is now emerging in Scandinavian countries. Although CWD cases have not been reported in Japan, in case of a CWD outbreak, it is critical to prepare for testing a large number of specimens. In the present study, we showed that a rapid post-mortem test kit, which is used for bovine spongiform encephalopathy surveillance in Japan, is valid for CWD prion detection. This article is protected by copyright. All rights reserved.

Ethanolamine Is a New Anti-Prion Compound

Prion diseases are a group of fatal neurodegenerative disorders caused by accumulation of proteinaceous infectious particles, or prions, which mainly consist of the abnormally folded, amyloidogenic prion protein, designated PrP^Sc. PrP^Sc is produced through conformational conversion of the cellular isoform of prion protein, PrP^C, in the brain. To date, no effective therapies for prion diseases have been developed. In this study, we incidentally noticed that mouse neuroblastoma N2a cells persistently infected with 22L scrapie prions, termed N2aC24L1-3 cells, reduced PrP^Sc levels when cultured in advanced Dulbecco's modified eagle medium (DMEM) but not in classic DMEM. PrP^C levels remained unchanged in prion-uninfected parent N2aC24 cells cultured in advanced DMEM. These results suggest that advanced DMEM may contain an anti-prion compound(s). We then successfully identified ethanolamine in advanced DMEM has an anti-prion activity. Ethanolamine reduced PrP^Sc levels in N2aC24L1-3 cells, but not PrP^C levels in N2aC24 cells. Also, oral administration of ethanolamine through drinking water delayed prion disease in mice intracerebrally inoculated with RML scrapie prions. These results suggest that ethanolamine could be a new anti-prion compound.

Khorana score at an initial chemotherapy is effective on predicting death in patients with gastrointestinal cancer

Background

The Khorana risk score (KRS) has been recommended for predicting an incidence of cancer-associated thrombosis (CAT). On the other hand, KRS is that the specific gravity of score for the primary tumor is too high and the prevalence of severe obesity is low, so there are some reports that the KRS is not effective in predicting CAT but is effective in predicting death.

Purpose

The purpose of this retrospective cohort study was to evaluate the efficacy of KRS on predicting CAT and all-cause death at an initial chemotherapy in patients with gastrointestinal cancer.

Methods

260 consecutive patients with no history of thrombosis who started an initial chemotherapy for gastrointestinal cancer during a 2-year period from January 2017 to December 2018 in our hospital were divided into 3 groups according to KRS and observed until December 2019 (122 patients (46.9%) in the low-risk group (0 points), 114 patients (43.8%) in the intermediate-risk group (1–2 points), and 24 patients (9.2%) in the high-risk group (3–6 points)). The incidence of CAT and all-cause death was compared among 3 groups.

Results

The median age of the patients was 67 (60–75) years, and 63.5% of them were male. CAT was observed in 61 patients (23.5%), and 84 patients (32.3%) died during the observation period. There was no difference in the incidence rate of CAT among 3 groups (Log-rank P=0.6), but all-cause death was a significant difference among 3 groups (high risk group: 54.2%, intermediate risk group: 36.0%, low risk group: 24.6%, p value=0.0023). After adjustment for multivariate analysis, the KRS high risk group was still significantly associated with death (HR: 2.83, 95% CI: 1.37–5.83, p value =0.0049), but not with CAT.

Conclusion

The Khorana score at an initial of chemotherapy in patients with gastrointestinal cancer is useful in predicting prognosis, but not CAT.

Funding Acknowledgement

Type of funding sources: None.

Promotion in solid phase reaction of Pt/SiOx bilayer film by electron-orbital-selective-excitation

A thermally impossible positive free energy reaction can proceed by electron-orbital-selective excitation. When the Si 2p core level is photo-excited in Pt/SiO_x bilayer films, Coulomb repulsion at the final two-hole state localized in the valence band by an interatomic Auger transition induces dissociation of the O atom and formation of a Si–Pt bond. Consequently, Pt₂Si silicide is formed by a positive free energy reaction. Under a single particle excitation of the valence band, low probability of the coexistence of the two-hole state for picosecond order suppresses to allow the reaction to proceed.

A thermally impossible positive free energy reaction can proceed by electron-orbital-selective excitation.

Strain-Dependent Prion Infection in Mice Expressing Prion Protein with Deletion of Central Residues 91-106

Conformational conversion of the cellular prion protein, PrP^C, into the abnormally folded isoform, PrP^Sc, is a key pathogenic event in prion diseases. However, the exact conversion mechanism remains largely unknown. Transgenic mice expressing PrP with a deletion of the central residues 91–106 were generated in the absence of endogenous PrP^C, designated Tg(PrP∆91–106)/Prnp^0/0 mice and intracerebrally inoculated with various prions. Tg(PrP∆91–106)/Prnp^0/0 mice were resistant to RML, 22L and FK-1 prions, neither producing PrP^Sc∆91–106 or prions in the brain nor developing disease after inoculation. However, they remained marginally susceptible to bovine spongiform encephalopathy (BSE) prions, developing disease after elongated incubation times and accumulating PrP^Sc∆91–106 and prions in the brain after inoculation with BSE prions. Recombinant PrP∆91-104 converted into PrP^Sc∆91–104 after incubation with BSE-PrP^Sc-prions but not with RML- and 22L–PrP^Sc-prions, in a protein misfolding cyclic amplification assay. However, digitonin and heparin stimulated the conversion of PrP∆91–104 into PrP^Sc∆91–104 even after incubation with RML- and 22L-PrP^Sc-prions. These results suggest that residues 91–106 or 91–104 of PrP^C are crucially involved in prion pathogenesis in a strain-dependent manner and may play a similar role to digitonin and heparin in the conversion of PrP^C into PrP^Sc.

[Elucidation of the Molecular Basis of Abnormal Prion Protein (PrP) Formation in a Cell-Free System Using Baculovirus and Insect Cell-derived Recombinant PrP]

The molecular basis underlying the conversion of normal prion protein (PrP^C) into abnormal prion protein (PrP^Sc) has not been fully elucidated. The protein-misfolding cyclic amplification (PMCA) technique, which can amplify PrP^Sc in vitro with the use of intermittent sonication, mimics the process of in vivo PrP^Sc replication. Accumulating evidence suggests that co-factors other than PrP may play a crucial role in the faithful replication of PrP^Sc. In conventional PMCA, brain homogenates (BHs) from normal animals are used as the PrP^C substrate. Since BHs contain many impurities, it is difficult to identify the co-factors using conventional PMCA. Thus, we developed a modified PMCA system using baculovirus and insect cell-derived recombinant PrP as a substrate (insect cell PMCA; iPMCA). We demonstrated that nucleic acids and glycosaminoglycans (GAGs) such as heparan sulfate (HS) or its analogue heparin (HP) are critical for PrP^Sc amplification in iPMCA. Of note, the addition of HS or HP restored the conversion efficiency in iPMCA under nucleic acid-depleted conditions. Moreover, the iPMCA products were infectious and preserved the strain properties of the input seed PrP^Sc. These data suggest that not only nucleic acids but also some GAGs play an important role in facilitating faithful replication of prions, at least in vitro.

Abstract P2-08-35: A significance of SUVmax levels on FDG-PET as a prognostic factor may be mediated by local immune environment of breast cancer

(Background) SUVmax levels (maximum radioactivity concentration per a pixel) on FDG-PET reflect glucose uptake and it is clinically useful as a prognostic factor. It is reported that breast cancer with high levels of SUVmax causes insufficient glucose concentration in stromal tissue, which results in suppressed cytotoxic T-lymphocytes function. These data may indicate that the prognostic significance of SUVmax levels is influenced by local immune environment of breast cancer. The aim of this study is to investigate whether local immune responses of breast cancer affect correlation of SUVmax levels and prognosis.

(Method) The 278 invasive breast cancer patients were recruited who underwent surgery at Hyogo College of Medicine Hospital and whose SUVmax levels in the breast were examined before surgery or neo-adjuvant therapy. The cutoff value of SUVmax levels was set at 3.585. Tumor infiltrate lymphocytes (TILs) were evaluated as a local immune response and the distributions of TILs were divided into three groups, inflamed (intra-tumoral lymphocytes, Inf), immune excluded (peri-tumoral lymphocytes, IE) and immune desert (very few lymphocytes, ID). During follow-up period (median 39 months), 21 patients relapsed.

(Results) Relapse free survival (RFS) in the SUVmax-high group was significantly worse than in the SUVmax–low group (p=0.0026). There was no correlation between TILs distribution patterns and RFS. In the IE+ID group (175 patients) SUVmax levels were not correlated with prognosis, but in the Inf group (103 patients) RFS of SUVmax-high was significantly worse than of SUVmax-low (p=0.0051). In the multivariate analysis including nodal status and nuclear grade, SUVmax levels of the Inf group was an independent prognostic factor.

(Discussion and conclusion) SUVmax levels in primary lesions were correlated with prognosis only in the Inf group and were not in the IE+ID group. A significance of SUVmax levels as a prognostic factor may be diverse depending on the local immune environment of breast cancer. A novel therapeutic strategy such as inducing suppression of glucose uptake in cancer cells is suggested for breast cancer with immune inflamed.

Citation Format: Fujimoto Y, Higuchi T, Watanabe T, Hida AI, Imamura M, Kitajima K, Miyoshi Y. A significance of SUVmax levels on FDG-PET as a prognostic factor may be mediated by local immune environment of breast cancer [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 P2-08-35.

Abstract P3-10-19: Significance of baseline neutrophil-to-lymphocyte ratio for progression-free survival of patients with HER2-positive locally advanced and metastatic breast cancer treated with trastuzumab emtansine

Purpose The prognosis of human epidermal growth factor receptor 2 (HER2)-positive locally advanced or metastatic breast cancers (MBCs) has dramatically improved due to the introduction of trastuzumab, pertuzumab, and trastuzumab emtansine (T-DM1). The efficacy of T-DM1 is prolonged for some patients; however, the predictive factors remain unknown. There is a report that T-DM1 induced antitumor immunity in patients treated with neoadjuvant therapy, with tumor infiltrating lymphocytes (TILs) increasing after the administration of T-DM1. Based on these observations, the benefits of T-DM1 for prognosis may be mediated by an immune reaction against breast cancers, at least in part. As an indicator of cancer immunity, in addition to TILs, the neutrophil-to-lymphocyte ratio (NLR) has been established in early breast cancers. In the present study, we investigated the usefulness of the NLR for treatment efficacy of T-DM1 in HER2-positive MBCs. Methods Fifty-three advanced or metastatic breast cancers treated with T-DM1 were retrospectively recruited from three institutes. The NLR in the peripheral blood was measured at baseline (just before the start of T-DM1) and after one cycle (just before the start of cycle 2). The cutoff value of the NLR was set at 2.56 (median value) and progression-free survival (PFS) and overall survival (OS) according to NLR levels were evaluated. Results The PFS of patients with NLR-low at baseline (NLR<2.56; n=26; median, not reached) was significantly better than that of patients with NLR-high (NLR≥2.56; n=27; median, 4.13 months; hazard ratio [HR], 0.226; 95% confidence interval [CI], 0.112-0.493; p=0.0001). There was a significant association between improved OS and a low NLR (HR, 0.384; 95% CI, 0.170-0.910; p=0.0296). In the subgroup analysis, patients with NLR-low consistently had improved PFS compared to those with NLR-high irrespective of the number of prior chemotherapy regimens, prior trastuzumab use, visceral metastasis, estrogen receptor status, and HER2 immunohistochemical staining score. According to univariable analysis of each clinical and biological factor for PFS, the NLR-low group was solely and significantly associated with favorable PFS compared with the NLR-high group (HR, 0.226; 95% CI, 0.112-0.493; p=0.0001). The NLR at baseline was significantly decreased (p=0.0010) and lymphocyte count was significantly increased after one cycle treatment (p=0.0005). Interestingly, the PFS of patients whose NLR was high at baseline but changed to low after one cycle (n=12; median PFS, 6.47 months) was better than that of patients with a consistently high NLR (n=14; median PFS, 3.27 months). Conclusion and Discussion A low baseline NLR was found to be significantly associated with improved PFS for patients treated with T-DM1. Interestingly, lymphocyte count was significantly increased in patients in the NLR-low group but not in the NLR-high group after one cycle treatment. Although detailed mechanisms remain unknown, the treatment efficacy of T-DM1 may be partly mediated by immunoreaction on the basis of present data. A low baseline NLR appears to be beneficial for treatment with T-DM1 in HER2-positive breast cancers.

Citation Format: Imamura M, Morimoto T, Egawa C, Miyagawa Y, Miyoshi Y. Significance of baseline neutrophil-to-lymphocyte ratio for progression-free survival of patients with HER2-positive locally advanced and metastatic breast cancer treated with trastuzumab emtansine [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 P3-10-19.

Achieving accountability through maternal death reviews in Nigeria: a process analysis

Maternal death reviews (MDRs) are part of the drive to increase accountability for maternal deaths and reduce their occurrence by identifying barriers to effective, quality care. However, conducting MDRs well is difficult; staff commitment and establishing a blame free environment are key challenges. By examining the communication strategies used in MDRs this study sought to understand how MDR members implement policy imperatives (e.g. 'no blame, no name') and manage the inevitable sensitivities of discussing a client's death in a multidisciplinary team. We observed and recorded four MDRs in Nigerian teaching hospitals and used conversation and discourse analysis to identify patterns in verbal and non-verbal interactions. MDRs were conducted in a structured way and had multidisciplinary representation. We grouped discursive strategies observed into three overlapping clusters: 'doing' no-name no-blame; fostering participation; and managing personal accountability. Within these clusters, explicit reminders, gentle enquiries and instilling a sense of togetherness were used in doing no-name, no-blame. Strategies such as questioning and invoking protocol were only partially successful in fostering participation. Regarding managing accountability, forms of communication which limit personal responsibility ('pass the buck') and resist passing the buck were observed. Detailed, lengthy eye witness accounts of dramatic events appeared to reduce staff's personal accountability. We conclude that interactional processes affect the meaningfulness of MDRs. In-depth, critical analysis depends on resisting 'passing the buck' by practitioners and chairs especially, who are also key to fostering participation and extracting value from multidisciplinary representation. Our innovative methods provide detailed insights into MDRs as an interactional process, which can inform design of training aimed at enhancing MDR members' skills. However, given the multitude of systemic challenges we should also adjust our expectations of MDRs and the individual practitioners tasked to perform them in the name of enhancing accountability for maternal death reduction.

Acute Graft Rejection and Formation of De Novo Donor-Specific Antibodies Triggered by Low Cyclosporine Levels and Interferon Therapy for Recurrent Hepatitis C Infection After Liver Transplantation: A Case Report

BACKGROUND

We report a case of acute rejection of a liver graft, together with the occurrence of de novo donor-specific antibodies (DSAs), in a 53-year-old Japanese man who had undergone deceased-donor liver transplantation.

METHODS

The graft rejection was triggered by low cyclosporine levels and pegylated interferon treatment for the recurrence of hepatitis C virus (HCV) infection 18 months after transplantation. Although the graft was ABO-compatible, pre-formed DSA B51 was detected; therefore, total plasma exchange was performed and intravenous rituximab (500 mg/body) was administered before transplantation.

RESULTS

DSA was absent 6 months after transplantation. HCV recurrence was treated with pegylated interferon-α-2a. Renal function deteriorated with this anti-HCV therapy, with serum cyclosporine levels decreasing to 50 ng/mL. A rapid virologic response was achieved, but liver function deteriorated after 3 months of anti-HCV therapy, with histologic evidence of acute cellular rejection and formation of de novo DSAs. Anti-thymocyte globulin was administered for 5 days, which led to immediate improvement in liver function. However, renal function declined, warranting hemodialysis. The patient recovered 2 months after acute rejection, although de novo DSAs persisted.

CONCLUSIONS

Careful immunologic monitoring may be required for patients receiving interferon therapy for HCV infection to maintain sufficient blood levels of immunosuppressive agents and to prevent acute liver graft rejection.

Distribution of the Carbohydrate Antigens, Du-Pan-2 and Ca19-9, in Tumors of the Lung

Aims and background

The carbohydrate chains of malignant cells appear to be related to oncofetal differentiation. The serum levels of CA19-9 have been reported to be evaluated in some patients with lung carcinomas, however, the distribution of carbohydrate antigens were not precisely described. We have investigated in this study the distribution of DU-PAN-2 and CA19-9 antigens in lung tumors.

Methods

Ninety five specimens of lung tumors were selected from surgical specimens. The expression of DU-PAN-2 and CA19-9 were studied by immunohystochemical techniques. The relationship between the expression of these antigens and the classification or the differentiation degree of the tumors were examined.

Results

DU-PAN-2 or CA19-9 antigens were detected in 41 (54%) and 45 (59%) cases of the 76 malignant epithelial tumors investigated. These antigens were detected in all types of malignant epithelial tumors, including squamous cell carcinomas, where they were mainly localized to the entire cell surface of malignant cells. In adenocarcinomas, large cell carcinomas and small cell carcinomas, however, these antigens were commonly detected both on the cell membrane and in the cytoplasm. There was positive correlation between the degree of differentiation and DU-PAN-2, but not CA19-9 expression. Among the non-epithelial tumors investigated, those antigens were detected in pulmonary blastomas but not in mesotheliomas.

Conclusions

Immunohistochemical studies for DU-PAN-2 and CA19-9 are useful for defining characteristics of the lung tumors. DU-PAN-2 could be a marker for differentiating between malignant epithelial tumors and mesotheliomas.

Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle

To determine oral transmissibility of the L-type bovine spongiform encephalopathy (BSE) prion, we orally inoculated 16 calves with brain homogenates of the agent. Only 1 animal, given a high dose, showed signs and died at 88 months. These results suggest low risk for oral transmission of the L-BSE agent among cattle.

Abstract P2-09-31: Predictive impact of absolute lymphocyte counts for progression-free survival in HER2-positive advanced breast cancer treated with pertuzumab and trastuzumab plus eribulin or nab-paclitaxel

Background: Tumor-infiltrating lymphocytes might be a one of predictive outcome of human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer (ABC) patients (pts) who treated with trastuzumab and pertuzumab (TP) plus docetaxel. Although peripheral blood-based parameter (PBBP) is reported as a prognostic indicator of patients with early breast cancers, utility of PBBP has not been studied in HER2-positive ABC.

Objective:The aim of our study was to determine whether PBBP is significant for predictive efficacy in HER2-positive ABC treated with TP combined with eribulin (ERI) or nab-paclitaxel (Nab-PTX).

Methods: The 51 patients' data from two single arm phase II trials was included in this retrospective-prospective study; ERI + TP (n=30) or Nab-PTX + TP (n=21) registered with UMIN000012375 or UMIN000006838, respectively. We assessed the PBBP in prospectively collected data and investigated their association with progression-free survival (PFS). In consideration of PBBP, we evaluated absolute lymphocyte count (ALC), neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR). The cutoff values of ALC, NLR, and PLR were set at 1000 cells/μL, 2, and 250, respectively.

Results:Median age at baseline was 58 years (range: 31-77). Median number of previous chemotherapy was 3 (range: 1-10). Pts had multiple metastases, 53% with LNs, 35% with bone, 25% with lung, 20% with liver, and 6% with brain. The objective response rate (CR+PR) and clinical benefit rate (CR+PR+ more than 6 month SD) were 37% (n=19) and 59% (n=30), respectively. The median PFS of all pts was 301 days (range: 21-1281). The PFS of pts with ALC-High was significantly better than those of ALC-low (hazard ratio (HR): 2.74, 95% confidence interval (CI): 1.28 to 5.86; p= .0097). Furthermore, improved PFS was obtained in pts with ALC greater than 1500 cells/μL compared with less than 1000 cells/uL (HR: 4.05, 95% CI: 1.60 to 11.6; p= .0029). Significant associations seem to exist irrespective of number of previous chemotherapy. Since we combined different studies for evaluating PBBP, ERI and Nab-PTX were calculated separately. Marginally significant associations between ALC and PFS were obtained both in ERI (HR: 2.18, 95% CI: 0.87 to 5.60; p=.0973) and Nab-PTX (HR: 3.26, 95% CI: 0.80 to 12.4; p=.0939). The PFS of NLR-low pts was significantly better than those of NLR-high (HR: 2.29, 95% CI: 1.01 to 5.90; p= .0477), but this statistical difference was inferior to those of ALC. There was no significant association between PLR and PFS.

Conclusions: Pre-treatment ALC-High was significantly correlated with favorable PFS of pts treated with TP irrespective of combination chemotherapy in HER2-positve ABC. Prolonged PFS of TP combination therapy might be obtained mediating through host systemic onco-immunity. These data obtained here suggest that a usefulness of ALC for selecting pts who might have clinical benefit from TP combination therapy for heavily treated HER2-positve ABC.

Citation Format: Araki K, Ito Y, Fukada I, Kobayashi K, Ohno S, Miyagawa Y, Imamura M, Kira A, Takatsuka Y, Egawa C, Suwa H, Miyoshi Y. Predictive impact of absolute lymphocyte counts for progression-free survival in HER2-positive advanced breast cancer treated with pertuzumab and trastuzumab plus eribulin or nab-paclitaxel [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-31.

Experimental Infection of Cattle With a Novel Prion Derived From Atypical H-Type Bovine Spongiform Encephalopathy

H-type bovine spongiform encephalopathy (H-BSE) is an atypical form of BSE in cattle. During passaging of H-BSE in transgenic bovinized (TgBoPrP) mice, a novel phenotype of BSE, termed BSE-SW emerged and was characterized by a short incubation time and host weight loss. To investigate the biological and biochemical properties of the BSE-SW prion, a transmission study was conducted in cattle, which were inoculated intracerebrally with brain homogenate from BSE-SW-infected TgBoPrP mice. The disease incubation period was approximately 15 months. The animals showed characteristic neurological signs of dullness, and severe spongiform changes and a widespread, uniform distribution of disease-associated prion protein (PrP^Sc) were observed throughout the brain of infected cattle. Immunohistochemical PrP^Sc staining of the brain revealed the presence of intraglial accumulations and plaque-like deposits. No remarkable differences were identified in vacuolar lesion scores, topographical distribution patterns, and staining types of PrP^Sc in the brains of BSE-SW- vs H-BSE-infected cattle. PrP^Sc deposition was detected in the ganglia, vagus nerve, spinal nerve, cauda equina, adrenal medulla, and ocular muscle. Western blot analysis revealed that the specific biochemical properties of the BSE-SW prion, with an additional 10- to 12-kDa fragment, were well maintained after transmission. These findings indicated that the BSE-SW prion has biochemical properties distinct from those of H-BSE in cattle, although clinical and pathologic features of BSW-SW in cattle are indistinguishable from those of H-BSE. The results suggest that the 2 infectious agents, BSE-SW and H-BSE, are closely related strains.

Subcutaneous Xenotransplantation of Hybrid Artificial Pancreas Encapsulating Pancreatic B Cell Line (MIN6): Functional and Histological Study

The biohybrid artificial pancreas is designed to enclose pancreatic endocrine tissues with a selectively permeable membrane that immunoisolates the graft from the host immune system, allowing those endocrine tissues to survive and control glucose metabolism for an extended period of time. The pancreatic B cell line MIN6 is established from a pancreas B cell tumor occurring in transgenic mice harboring the human insulin promoter gene connected to the SV40 T-antigen hybrid gene. It has been proven that glucose-stimulated insulin secretion in MIN6 cells retains a concentration-dependent response similar to that of normal islets. In this study, we performed the histological and functional examination of three-layer microbeads employing MIN6 cells after subcutaneous xenotransplantation to evaluate this device as bioartificial pancreas. MIN6 cells were microencapsulated in three-layer microbeads formulated with agarose, polystyrene sulfonic acid, polybrene, and carboxymethyl cellulose. Microbeads were xenogenically implanted in the subcutaneous tissue of the back of Lewis rats with streptozotocin-induced diabetes. One week after implantation, microbeads were retrieved and cultured for 24 h before the static incubation. There was no evidence of adhesion to the graft and the fibrosis in the transplantation site as determined by gross visual inspection. Microscopic examination demonstrated that retrieved microbeads maintained normal shape, containing intact MIN6 cells. Histological study showed that these MIN6 cells in the microbeads appeared to be viable without cellular infiltration within or around the microbeads. Immunohistochemical analysis of the microbeads clearly revealed the intense staining of insulin in the cytoplasm of encapsulated MIN6 cells. Insulin productivity of MIN6 cells in the microbeads is strongly suggested to be preserved. In response to 16.7 mM glucose stimulation, static incubation of microbeads 1 wk after implantation caused the 2.3 times increase in insulin secretion seen after 3.3 mM glucose stimulation (84.3 ± 10.0 vs. 37.4 ± 10.7 μU/3 × 106 cells/hr, n = 5 each, p < 0.01). This study demonstrates that three-layer microbeads encapsulating MIN6 cells retain excellent biocompatibility and maintain good insulin secretion even after subcutaneous xenotransplantation, suggesting the possible future clinical application of this unique bioartificial pancreas to subcutaneous xenotransplantation.

Improved Large-Scale Isolation of Breeder Porcine Islets: Possibility of Harvesting from Nonheart-Beating Donor

To establish a large-scale isolation procedure for adult porcine islets usable as a donor source for xenotransplantation and as a model of human islet isolation, we improved several characteristics of the conventional isolation procedure. At a slaughterhouse we first selected a breeder pig over 1.5 years old (and over 200 kg in weight) with warm ischemic time (WIT) of 15 ± 2 minutes as nonheart-beating donors. Then, we made a special enzymic mixture that consisted of collagenase S-1 (260 U/mg, NittaZelatin, Japan), collagenase P (1.86 U/ml Lyo Boehringer-Mannheim, USA), DNase (Sigma, St. Louis, Mo), Disparse (NittaZelatin, Japan), and protease inhibitor (Sigma). Third, this mixture was injected very gently into the pancreatic duct at the time of pancreatic harvesting. To prevent overdigestion of the pancreas, the mixture was first cooled to less than 10°C. Fourth, during the warm digestion of pancreas, the pancreas with the enzymic mixture was quietly put in a water bath at 37°C without mechanical shaking. Fifth, we purified the islets with a COBE 2991 cell processor by the Dextran 70 gradient method, because Dextran 70 is very cheap and has the same purification effect as the Ficoll gradient. The results of 10 consecutive breeder porcine islet isolations are reported. The total yield of isolations of islets over 50 μm in the longest diameter after staining with Dithizone (DTZ) was 85,900 ± 19,954 islets, 291,667 ± 240,452 IEQ (2,900 ± 2,324 IEQ/g). The purity of the isolated islets was very high: 90.2 ± 3.8%. Glucose stimulation during in vitro incubation induced significant insulin release from isolated breeder porcine islets. In two of the diabetic rats receiving encapsulated islets grafts using a mesh-reinforced polyvinyl alcohol hydrogel bag (MRPB), a prominent reduction in serum glucose levels (less than 200 mg/dL) persisted for 13 and 19 days, respectively, after intraperitoneal xenotransplantation islets without immunosuppression. In conclusion, we succeeded in a more efficient and less-expensive isolation of a large amount of adult porcine islets from a nonheart-beating donor.

Prolonged Effect of Troglitazone (CS-045) on Xenograft Survival of Hybrid Artificial Pancreas

Troglitazone (CS-045), a thiazolidinedione derivative, is a new oral antidiabetic agent that enhances insulin sensitivity and improves insulin responsiveness. In this study we examined the effects of CS-045 on the survival of xenografted bioartificial pancreas. Isolated rat islets were microencapsulated with three-layer agarose microcapsules (polybrene, carboxymethyl cellulose, and an agarose-polystyrene sulfonic acid mixture). Diabetes was induced by intraperitoneal injection of streptozotocin 220 mg/kg. Recipient diabetic mice were separated into two groups. In the CS-045 treated group, the recipient mice were given feed mixed with CS-045 (0.2% w/w) starting from 1 wk before transplantation up to graft failure. The mice in the control group had feed without CS-045. Three hundred microencapsulated rat islets were xenotransplanted into the intraperitoneal cavity of each recipient mouse in both groups. One month after xenotransplantation, IVGTT was performed for all recipients. Xenotransplantation of 300 rat islets in microcapsules decreased the nonfasting blood glucose levels of both groups within 2 days. In the CS-045-treated group (n = 3), the normoglycemic period lasted for more than 1 mo without administration of immunosuppressive drugs (45 ± 4.3 days). However, in the control group (n = 4), the blood glucose levels of all recipients were already elevated on day 4. In the IVGTT study, the glucose assimilation was markedly and significantly better in the CS-045-treated group than in the control group (K = 1.7 ± 0.1 vs. 0.7 ± 0.28 respectively, p <0.01). This study demonstrates that a newly developed oral antidiabetic agent, CS-045 could favorably ameliorate the diabetic state of the recipients xenotransplanted with the bioartificial pancreas, leading to an improved glucose tolerance and longer xenograft survival.

Abstract P2-05-27: Baseline serum CA15-3 levels are associated with prognosis for breast cancer patients with non-complete pathological response to neoadjuvant chemotherapy

Background: It has been well demonstrated that patients who achieved pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) had a favorable prognosis compared with patients who did not (non-pCR). Even though pCR was not attained, reduction in tumor volume after chemotherapy may be associated with improved prognosis for a certain number of patients. However, the association between residual tumor volume and prognosis is not necessarily consistent. In order to identify substitute markers for breast cancer patients with non-pCR after NAC, we investigated the impact of serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA15-3) at baseline as well as post-NAC.

Patients and Methods: Ninety-six breast cancer patients treated with NAC and operated on at the Hyogo College of Medicine were recruited for this study. Serum CEA and CA15-3 were measured prior to chemotherapy as well as at completion of pre-operative treatment. The optimal cutoff points for CEA (1.55ng/m, normal range: &lt;5.0ng/ml) and CA15-3 (13.25U/ml, normal range: &lt;28.0U/ml) for relapse-free survival (RFS) were determined by analyzing the area under receiver operating characteristic curves in another study involving 613 breast cancer patients. Expression levels of Ki67 in samples obtained at pre- and post-NAC were also determined by means of immunohistochemical staining. Pathological complete response was classified as the absence of residual invasive cancer in the breast and lymph nodes. During a 2.13 years median follow-up period, 15 patients suffered relapse.

Results: pCR and non-pCR was attained by 21 and 75 patients, respectively. For the non-pCR patients, serum CEA levels at baseline were classified into high (n=35) and low (n=38) and serum CA15-3 levels at baseline into high (n=31) and low (n=43). RFS of non-pCR patients with high serum CA15-3 levels was significantly worse than of those with low levels (3-year RFS: 0.47 vs 0.93; p=0.0009). RFS for patients with high and low serum levels of CA15-3 after NAC was also significantly different (p=0.037). As for CEA, no significant association with RFS was observed either at baseline or post-NAC. Univariate analysis demonstrated that tumor size and baseline CA15-3 were significant prognostic factors for RFS. Multivariate analysis showed that both tumor size (hazard ratio (HR): 3.88, 95% confidence interval (CI): 1.21-12.35, p=0.023) and baseline CA15-3 (HR: 13.51, 95% CI: 1.74-105.08, p=0.013) were significant and independent risk factors for relapse. As for lymph node metastasis, tumor grade, residual tumor size and pre- and post-NAC Ki67 expression levels of patients with non-pCR showed no significant association with RFS.

Conclusion and discussion: High levels of serum CA15-3 at baseline constituted a significantly worse prognosis for breast cancer patients with non-pCR. Tumor size at baseline but not residual size and baseline CA15-3 seems to suitable as a substitute for prediction of outcome for patients with non-pCR. Our findings suggest that these markers may be useful for identifying patients with poor prognosis who may be candidates for additional adjuvant treatment.

Citation Format: Fujimoto Y, Imamura M, Higuchi T, Nishimukai A, Yanai A, Miyagawa Y, Murase K, Takatsuka Y, Miyoshi Y. Baseline serum CA15-3 levels are associated with prognosis for breast cancer patients with non-complete pathological response to neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-27.

Comparison of ultrasonographic joint and tendon findings in hands between early, treatment-naïve patients with systemic lupus erythematosus and rheumatoid arthritis

Although both systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) may lead to joint deformity, SLE arthritis is typically non-erosive and often accompanied by Jaccoud's deformity. Therefore, we examined characteristics of joint and tendon lesions in patients with SLE and RA by ultrasonography. Fifteen treatment-naïve SLE patients and 40 treatment-naïve RA patients with joint symptoms were included in this study. The hand joints and related tendons were ultrasonographically examined using grey-scale (GS) and power Doppler (PD). Joint involvement was comparably observed in patients with SLE and RA (80% versus 95%, p = 0.119). However, tendon involvement was more frequent in SLE than in RA (93% versus 65%, p = 0.045), especially in the wrist joints (73% versus 40%, p = 0.037). When we investigated the intensity of US findings, the joint synovitis score (GS + PD) per affected joint was lower in SLE than RA (2.0 versus 2.6, p = 0.019), while tendon inflammation score was not significantly different (2.1 versus 2.2, p = 0.738). Finally, the examination of concordance between joint and tendon involvement in the same finger revealed that joint lesion appeared in only 49% of fingers having tendon involvement in the SLE group, which was significantly less than 74% in the RA group ( p = 0.010). Thus, as compared with RA, SLE arthropathy is characterized by the predominance of tenosynovitis/periextensor tendon inflammation, which is likely to develop independently from joint synovitis.

Heparan Sulfate and Heparin Promote Faithful Prion Replication in Vitro by Binding to Normal and Abnormal Prion Proteins in Protein Misfolding Cyclic Amplification

The precise mechanism underlying the conversion of normal prion protein (PrP^C) into abnormal prion protein (PrP^Sc) remains unclear. Protein misfolding cyclic amplification (PMCA), an in vitro technique used for amplifying PrP^Sc, results in PrP^Sc replication that preserves the strain-specific characteristics of the input PrP^Sc; thus, PMCA mimics the process of in vivo PrP^Sc replication. Previous work has demonstrated that in PMCA, nucleic acids are critical for PrP^Sc amplification, but little information has been reported on glycosaminoglycan (GAG) participation in PrP^Sc replication in vitro Here, we investigated whether GAGs play a role in the faithful replication of PrP^Sc by using a modified PMCA performed with baculovirus-derived recombinant PrP (Bac-PrP) as a substrate. The addition of heparan sulfate (HS) or its analog heparin (HP) restored the conversion efficiency in PMCA that was inhibited through nucleic acid depletion. Moreover, the PMCA products obtained under these conditions were infectious and preserved the properties of the input PrP^Sc These data suggest that HS and HP play the same role as nucleic acids in facilitating faithful replication of prions in PMCA. Furthermore, we showed that HP binds to both Bac-PrP and Bac-PrP^Sc through the sulfated groups present on HP and that the N-terminal domain of Bac-PrP^Sc might potentially not be involved in the binding to HP. These results suggest that the interaction of GAGs such as HS and HP with PrP^C and/or PrP^Sc through their sulfate groups is critical for the faithful replication of prions.

Pharmacokinetics, efficacy and safety of daclatasvir plus asunaprevir in dialysis patients with chronic hepatitis C: pilot study

The aim of this study was to evaluate the pharmacokinetic profile of daclatasvir (DCV) and asunaprevir (ASV) dual therapy in haemodialysis patients infected with hepatitis C virus (HCV). Eighteen haemodialysis patients and 54 patients with normal renal function were treated with DCV and ASV dual therapy for 24 weeks. We evaluated the pharmacokinetic profiles of DCV and ASV and examined the rate of sustained virological response 12 weeks after the end of treatment (SVR₁₂ ) and incidence of adverse events during treatment of haemodialysis patients infected with chronic HCV genotype 1 infection. To adjust for potential differences in baseline characteristics between haemodialysis patients and patients with normal renal function, we used propensity scores case-control matching methods. Area under the plasma concentration time curve from 0 to 6 h (AUC_{0-6 h} ) of DCV was slightly lower in haemodialysis patients than in patients with normal renal function (P > 0.6). AUC_{0-6 h} of ASV was significantly lower in haemodialysis patients (P = 0.012). SVR₁₂ rates were 100% (18/18) for haemodialysis and 96.2% (52/54) for patients with normal renal function. Changes in mean log₁₀ HCV RNA levels and viral response were higher in haemodialysis patients compared to patients with normal renal function. No discontinuations due to adverse events occurred. In conclusion, DCV and ASV dual therapy for HCV infection is effective and safe with similar results in haemodialysis patients compared to patients with normal renal function.

Identification of the first case of atypical scrapie in Japan

A Corriedale ewe was confirmed as the first atypical scrapie case during an active surveillance program for transmissible spongiform encephalopathies in small ruminants in Japan. The animal was homozygous for the AF₁₄₁RQ haplotype of PRNP. The animal showed clinical neurological signs possibly due to listeriosis before culling. Western blot analysis showed an unusual multiple banded pattern with a low-molecular fragment at ~7 kDa. Histopathology revealed suppurative meningoencephalitis caused by listeriosis in the brainstem. Fine granular to globular immunostaining of disease-associated prion proteins was mainly detected in the neuropil of the spinal tract of the trigeminal nerve and in the white matter of the spinocerebellar tract. Based on these results, this case was conclusively diagnosed as atypical scrapie with encephalitic listeriosis.

Transmission of atypical scrapie to homozygous ARQ sheep

Two Cheviot ewes homozygous for the A₁₃₆L₁₄₁R₁₅₄Q₁₇₁ (AL₁₄₁RQ) prion protein (PrP) genotype were exposed intracerebrally to brain pools prepared using four field cases of atypical scrapie from the United Kingdom. Animals were clinically normal until the end of the experiment, when they were culled 7 years post-inoculation. Limited accumulation of disease-associated PrP (PrP^Sc) was observed in the cerebellar molecular layer by immunohistochemistry, but not by western blot or enzyme-linked immunosorbent assay. In addition, PrP^Sc was partially localized in astrocytes and microglia, suggesting that these cells have a role in PrP^Sc processing, degradation or both. Our results indicate that atypical scrapie is transmissible to AL₁₄₁RQ sheep, but these animals act as clinically silent carriers with long incubation times.

Multiple affinity purification of a baculovirus-derived recombinant prion protein with in vitro ability to convert to its pathogenic form

We previously showed that baculovirus-derived recombinant prion protein (Bac-PrP) can be converted to the misfolded infectious form (PrP^Sc) by protein misfolding cyclic amplification, an in vitro conversion technique. Bac-PrP, with post-translational modifications, would be useful for various applications such as using PrP as an immunogen for generating anti-PrP antibody, developing anti-prion drugs or diagnostic assays using in vitro conversion systems, and establishing an in vitro prion propagation model. For this purpose, highly purified Bac-PrP with in vitro conversion activity is necessary for use as a PrP^C source, to minimize contamination. Furthermore, an exogenous affinity tag-free form is desirable to avoid potential steric interference by the affinity tags during the conversion process. In this study, we established purification methods for the untagged Bac-PrP under native conditions by combining exogenous double-affinity tags, namely, a polyhistidine-tag and a profinity eXact tag, with an octarepeat sequence of the N-terminal region of PrP, which has metal ion-binding affinity. The untagged Bac-PrP with near-homogeneity was obtained by three-step affinity purification, and it was shown that the final, purified Bac-PrP could convert to its pathogenic form. The presented purification procedure could be applied not only to PrP but also to other eukaryotic, recombinant proteins that require high purity and intact physiological activity.

Abstract P2-08-24: High levels of serum C-terminal crosslinking telopeptide of type 1 collagen at baseline are associated with poor prognosis for breast cancer patients

Background: It has been demonstrated that adjuvant treatment using bisphosphonate may reduce recurrence among breast cancer patients. However, these improved prognoses of patients are reportedly limited to breast cancers of estrogen receptor (ER)-positive and postmenopausal women. Although the mechanisms of the effects of bisphosphonate remain unknown, this finding seems to represent support for the hypothesis that suppression of bone resorption by bisphosphonate results in favorable prognoses at least for patients in this subset. In order to determine the prognostic significance of bone resorption in breast cancer patients, we investigated these markers c-terminal crosslinking telopeptide of type I collagen (1CTP) and N-telopeptide of type I collagen (NTX).

Patients and Methods: 469 breast cancer patients were recruited who were operated on Hyogo College of Medicine and histologically confirmed to have invasive carcinoma. Serum 1CTP and NTX were measured preoperatively with the two-antibody radioimmunoassay and enzyme-linked immunosorbent assay methods, respectively, and blood samples were obtained before treatment from patients who were treated with neoadjuvant chemotherapy or endocrine therapy. The area under receiver operating characteristic curves were applied and optimal cutoff values were set at 3.6ng/ml for 1CTP, and 10.55nmolBCE/L premenopausal and 14.05nmolBCE/L postmenopausal for NTX. The relationships between these bone turnover markers and various clinicopathological characteristics were evaluated with the chi square or Fisher's exact test. The log-rank test was used to compare relapse-free survival (RFS) in Kaplan-Meier plots. Associations of RFS were assessed with a Cox proportional-hazards model based on the results of univariate and multivariate analyses. Differences were considered statistically significant if p&lt;0.05.

Results: There were significantly more 1CTP-high patients among postmenopausal women and RFS of 1CTP-high patients was significantly worse than that of 1CTP-low patients (5-year RFS: 0.65 vs 0.86; p=0.0002). Similarly, NTX-high patients were significantly associated with postmenopausal status, but there was no significant association between NTX-high worse RFS (p=0.0976). Multivariate analysis of tumor size, lymph node metastasis and nuclear grade identified 1CTP (hazard ratio: 2.04, 95% confidence interval: 1.13-3.68; p=0.018) as a significant independent prognostic factor. Subset analyses of 1CTP showed that prognosis was consistently worse recognized for postmenopausal (p=0.0002), but not premenopausal (p=0.37) patients. Furthermore, prognosis for 1CTP-high patients was worse for the estrogen receptor (ER)-positive subset (p=0.0005) but not for the ER-negative subset (p=0.22).

Conclusion and discussion: High levels of serum bone resorption markers at baseline were identified as significant unfavorable prognostic factors for breast cancer patients. The prognostic significance of 1CTP seems to be prominent for postmenopausal patients with ER-positive breast cancers. These findings suggest the use of bone-modifying agents as an adjuvant therapy may be beneficial for breast cancer patients, especially for patients with high serum levels of 1CTP.

Citation Format: Imamura M, Nishimikai A, Yanai A, Miyagawa Y, Higuchi T, Ozawa H, Murase K, Takatsuka Y, Miyoshi Y. High levels of serum C-terminal crosslinking telopeptide of type 1 collagen at baseline are associated with poor prognosis for breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-24.

Abstract P6-16-01: Differences in patterns of change of bone turnover markers during treatment with bone-modifying agents of breast cancer patients with bone metastases

Background: Bone-modifying agents have demonstrated their efficacy for treatment by suppressing osteoclast function. The activity of bone-modifying agents can be monitored by means of bone resorption markers such as c-terminal crosslinking telopeptide of type I collagen (1CTP) and N-telopeptide of type I collagen (NTX) as well as bone forming marker bone-specific alkaline phosphatase (BAP). In contrast to these markers which indirectly indicate bone turnover, tartrate-resistant acid phosphatase-5b (Tracp-5b) has been established as a direct marker showing osteoclast number and activity. The aim of this study was to identify the relative significance of these bone turnover markers as indicators of treatment efficacy induced by bone-modifying agents for breast cancer patients with bone metastases.

Patients and Methods: For this study, 52 breast cancer patients with bone metastases treated with bone-modifying agents were recruited. Zoledronic acid and denosumab were administered as bone-modifying agents to 36 and 22 patients, respectively (for 6 patients, denosumab was used after zoledronic acid). Serum Tracp-5b, 1CTP, NTX and BAP were measured with, respectively, the EIA (enzyme immunoassay), RIA (two-antibody radioimmunoassay), ELISA (enzyme-linked immunosorbent assay) and CLEIA (chemiluminescent enzyme immunoassay) method. Blood samples were obtained pretreatment and 1, 3 and 6 months after treatment. Changes in these bone turnover markers were statistically analyzed with Friedman's test, and correlation between serum markers and clinicopathological factors was calculated with Mann-Whitney's test.

Results: Serum tracp-5b decreased significantly after treatment (p&lt;0.0001). The baseline median value of Tracp-5b (457.5mU/dl, range: 173-1630mU/dl) had been reduced to 137mU/dl (91-795mU/dl) 1 month after treatment, but no further reduction was observed after that. For 13 out of 15 patients to whom Tracp-5b was administered, abnormally high levels (above 420mU/dl) decreased to normal range with one month treatment. Serum NTX was also significantly reduced after treatment (p=0.0007). The median baseline value (16.5nmolBCE/L, 6.1-52.2nmolBCE/L) was diminished after 1 month (to 10.9nmolBCE/L, 7.0-49.5nmolBCE/L), and further reduction of NTX was observed after 3 months (9.55nmolBCE/L, 6.4-56.0nmolBCE/L). Similarly, baseline BAP (15.1μg/L, 6.4-81.3μg/L) decreased significantly (p=0.0032), a reduction which was obtained after 3 months (10.15μg/L, 6.1-51.7μg/L), but not after 1 month (13.0μg/L, 7.7-137.0μg/L). On the other hand, reduction in 1CTP was not significant (p=0.83).

Conclusion and discussion: Although baseline values of the bone turnover markers Tracp-5b, NTX and BAP decreased significantly after treatment with bone-modifying agents, the pattern of reduction for these three markers varied. Tracp-5b appears to reflect efficacy of bone-modifying agents most quickly and sensitively, possibly due to its direct link to the number and activity of osteoclasts. These findings may prove usefulness of Tracp-5b when considering the efficacy of various bone-modifying agents in clinical practice.

Citation Format: Higuchi T, Nishimukai A, Yanai A, Miyagawa Y, Murase K, Imamura M, Ozawa H, Takatsuka Y, Miyoshi Y. Differences in patterns of change of bone turnover markers during treatment with bone-modifying agents of breast cancer patients with bone metastases. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-16-01.

Two patients treated with simeprevir plus pegylated-interferon and ribavirin triple therapy for recurrent hepatitis C after living donor liver transplantation: case report

We previously reported our data on telaprevir (TVR) used in combination with pegylated-interferon and ribavirin (PEG-IFN/RBV) for the treatment of recurrent hepatitis C virus (HCV) genotype 1 infection after liver transplantation (LT). TVR substantially increases the blood levels of immunosuppressive agents such as cyclosporine and tacrolimus for drug-drug interactions. On the other hand, the effect of simeprevir (SMV) on the blood levels of these immunosuppressive agents is unclear. We report 2 patients who achieved viral responses with little effect on the blood levels of cyclosporine and tacrolimus using SMV plus PEG-IFN/RBV treatment. The first was a 71-year-old woman with HCV-related liver cirrhosis and hepatocellular carcinoma who failed to respond to PEG-IFN/RBV after living donor LT. She was treated with 40 mg/d of cyclosporine, and received SMV plus PEG-IFN/RBV treatment. The second was a 65-year-old man with HCV-related liver cirrhosis who failed to respond to PEG-IFN/RBV after living donor LT. He was treated with 3 mg/d of tacrolimus, and received SMV plus PEG-IFN/RBV treatment. Serum HCV RNA became undetectable using TaqMan polymerase chain reaction (PCR) test after 4 weeks of treatment in both patients, and no remarkable fluctuation in blood concentration was observed either in cyclosporine or tacrolimus during the 12 weeks of SMV treatment. Completion of 12-week SMV triple therapy was followed by PEG-IFNα2b plus RBV, and both patients achieved sustained virological response 12 weeks after the end of treatment. SMV plus PEG-IFNRBV treatment showed a remarkable viral response with little effect on blood levels of immunosuppressive agents for recurrent HCV genotype 1 infection after LT.

Proximity of SCG10 and prion protein in membrane rafts

The conversion of normal cellular prion protein (PrPC) into its pathogenic isoform (PrPSc) is an essential event in prion pathogenesis. In culture models, membrane rafts are suggested to play a critical role in PrPSc formation. To identify the candidate molecules capable of interacting with PrPC and facilitating PrPSc formation in membrane rafts, we applied a novel biochemical labeling method termed enzyme-mediated activation of radical sources. Enzyme-mediated activation of radical sources was applied to the Lubrol WX insoluble detergent-resistant membrane fractions from mouse neuroblastoma (N2a) cells in which the surface PrPC was labeled with HRP-conjugated anti-PrP antibody. Two-dimensional western blots of these preparations revealed biotinylated spots of approximately 20 kDa with an isoelectric point of 8.0-9.0. Liquid chromatography-tandem mass spectrometry analysis resulted in the identification of peptides containing SCG10, the neuron-specific microtubule regulator. Proximity of SCG10 and PrPC was confirmed using proximity ligation assay and co-immunoprecipitation assay. Transfection of persistently 22L prion-infected N2a cells with SCG10 small interfering RNA reduced SCG10 expression, but did not prevent PrPSc accumulation, indicating that SCG10 appears to be unrelated to PrPSc formation of 22L prion. Immunofluorescence and western blot analyses showed reduced levels of SCG10 in the hippocampus of prion-infected mice, suggesting a possible association between SCG10 levels and the prion neuropathogenesis. By applying a novel biochemical labeling method against detergent-resistant membrane fractions from mouse neuroblastoma cells, the neuron-specific microtubule-destabilization protein, SCG10 was identified as a novel candidate that is proximate to normal prion protein (PrP) in membrane rafts. SCG10 seemed unrelated to disease-related PrP formation under certain conditions, while there is a possible association between SCG10 levels and prion neuropathogenesis. Cover Image for this issue: doi: 10.1111/jnc.13310.

Occurrence of adverse events caused by valganciclovir as pre-emptive therapy for cytomegalovirus infection after allogeneic stem cell transplantation is reduced by low-dose administration

BACKGROUND

Pre-emptive therapy with valganciclovir (VGCV) has become the standard therapy for preventing cytomegalovirus (CMV) infection after allogeneic hematopoietic stem cell transplantation (HSCT). The effectiveness of low-dose VGCV (900 mg per day) has been shown to be equal to that of standard-dose VGCV (900 mg twice daily); however, individualized optimal dosing and toxicity of VGCV have not been reported.

METHODS

We conducted a retrospective study to evaluate the optimal dose of VGCV as pre-emptive therapy for preventing CMV infection by comparing the frequency of adverse events (AEs) and clinical efficacy in a low-dose VGCV group with those in a standard-dose VGCV group. Thirty-eight patients who were administered VGCV because of CMV antigenemia after HSCT were analyzed.

RESULTS

Neutropenia (standard-dose group: 33%, low-dose group: 15%, P = 0.26) and thrombocytopenia (standard-dose group: 39%, low-dose group: 15%, P = 0.14) were frequent AEs of VGCV, and a significantly higher frequency of overall AEs was detected in the standard-dose group than in the low-dose group (P < 0.01). In comparison of dosage based on weight, dosage of VGCV >27 mg/kg was closely related to onset of AEs (P = 0.04).

CONCLUSIONS

Low-dose VGCV was not inferior in clinical efficacy, including clearance rate of CMV antigenemia and incidence of consequent CMV disease, to standard-dose VGCV as was previously reported. Initial low-dose VGCV for pre-emptive CMV therapy markedly reduces hematologic toxicity and has clinical efficacy equivalent to that of standard-dose VGCV. It is therefore reasonable for patients, except for noticeably overweight patients, to be given initial low-dose VGCV.

Post-operative infection of endoscopic submucosal dissection of early colorectal neoplasms: a case-controlled study using a Japanese database

WHAT IS KNOWN AND OBJECTIVE

Endoscopic submucosal dissection of early colorectal neoplasms (ESD-ECN) is known to be an operation with risk of contamination, possibly requiring pre-operative antimicrobial prophylaxis for the prevention of post-operative infection. However, an evaluation of the need for pre-operative antimicrobial prophylaxis for ESD-ECN has yet to be reported. The objective of this study was to determine whether pre-operative antimicrobial prophylaxis is associated with a reduced incidence of post-operative infection following ESD-ECN.

METHODS

The present retrospective case-controlled study utilized a database built from the medical records of 14 university hospitals throughout Japan. Patients who were admitted and discharged from the hospital from April 2012 to October 2013 and who had undergone ESD-ECN were included in the study. Patients who had been undergone any other operation during their course of hospitalization, and patients who were prescribed antimicrobial agents for reasons other than post-operative infection or for prophylaxis were excluded. Characteristics of the study population, pre-operative antimicrobial prophylaxis and antimicrobial therapy for post-operative infection were investigated. In addition, we compared the characteristics of patients with post-operative infection (PI) and those with no post-operative infection (NPI). Univariate analyses were used to estimate the odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS AND DISCUSSION

We obtained the records of 522 patients who had undergone ESD-ECN from the database. After application of exclusion criteria, 421 patients were enrolled. The post-operative infection rate was 1·2%. Peritonitis was found most to be the most common post-operative infection (44%). Pre-operative antimicrobial prophylaxis was used for 314 patients (75%), with a median duration of 3·0 (range 1-11) days. Cefotiam was most frequently prescribed for pre-operative antimicrobial prophylaxis (56%). Antimicrobial therapies were started 1-10 days after ESD-ECN for a duration of 1-14 days. Pre-operative antimicrobial prophylaxis was not associated with post-operative infection rate, with an OR (95% CI) of 0·73 (0·08-6·61). However, digestive tract perforation was shown to be associated with post-operative infection and had an OR (95% CI) of 17·1 (1·66-176·45).

WHAT IS NEW AND CONCLUSION

Post-operative infection is an exceedingly rare event following ESD-ECN. Pre-operative antimicrobial prophylaxis had no significant effect on post-operative infection following ESD-ECN and thus may be unnecessary. Instead, prevention of digestive tract perforation may be more critical for the decrease in post-operative infections.

Diffuse Liver Metastasis of Small-Cell Lung Cancer Presenting as Acute Liver Failure and Diagnosed by Transjugular Liver Biopsy: A Rare Case in Whom Nodular Lesions Were Detected by Enhanced CT Examination

Small-cell lung cancer (SCLC) is a subgroup of lung cancer with a high frequency of liver metastasis, which is a predictor of poor prognosis. Diffuse liver metastases of SCLC with no visible nodular lesions in the liver when examined using computed tomography (CT) are relatively rare; however, a few cases with rapid progression to acute liver failure that were diagnosed after death have been reported. In this paper, we report a 63-year-old man with diffuse liver metastases of SCLC that were histologically diagnosed using a transjugular liver biopsy while the patient was alive, even though no lesions were visible during a contrast-enhanced CT examination.

Ribavirin dose reduction during telaprevir/ribavirin/peg-interferon therapy overcomes the effect of the ITPA gene polymorphism

Treatment success of chronic hepatitis C virus genotype 1 infection has improved with the advent of telaprevir plus peg-interferon/ribavirin triple combination therapy. However, the effect of inosine triphosphatase (ITPA) polymorphism on dose reduction during triple therapy, especially during the postmarketing phase, has not been sufficiently evaluated. We analysed 273 patients with genotype 1 infection who were treated with triple therapy and assessed the effect of the ITPA polymorphism on dose reduction. ITPA and IFNL4 SNP genotypes were determined by the Invader assay. A stepwise multivariate regression analysis was performed to identify factors associated with outcome of the therapy. The overall sustained viral response (SVR) rate 12 weeks after the end of therapy was 80.2% (219/273). Decline of haemoglobin was significantly faster, and ribavirin was more extensively reduced in patients with ITPA SNP rs1127354 genotype CC than CA/AA. Extensive reduction of ribavirin resulted in mild reduction of telaprevir and peg-interferon, but no significant increase in viral breakthrough. Although the amount of telaprevir given was slightly higher in CA/AA patients, the total dose of peg-interferon and the SVR rate did not differ between the two groups. Multivariate analysis showed that IFNL4 but not ITPA SNP genotype, platelet count and peg-interferon adherence were significantly associated with outcome of therapy. Postmarketing-phase triple therapy resulted in a high SVR rate in spite of extensive ribavirin dose reduction in a diverse patient population, indicating the importance of treatment continuation and appropriate management of adverse events.