Search

Background Postoperative pneumonia is one of the major complications after esophagectomy. The aim of this study was to determine whether bacterial cultures before esophagectomy could predict occurrence of postoperative pneumonia and help treatment strategies for postoperative pneumonia. Methods Sixty-nine patients who underwent subtotal esophagectomy at Fukushima Medical University hospital between January 2017 and May 2021 were included in this study. We collected sputum, oral and/or nasopharyngeal swabs for bacterial culture preoperatively from all patients and from those who were suspected of postoperative pulmonary infections. We compared cultured pathogenic bacteria obtained preoperatively and postoperatively from patients who developed postoperative pneumonia, and investigated their association with incidence of postoperative pneumonia. Fisher’s exact test was used to compare categorical variables between groups, and Wilcoxon test was used to compare continuous variables. Risk factors for postoperative pneumonia and severe pneumonia were analyzed using multivariate logistic regression models. Results Postoperative pneumonia occurred in 22 (31%) of the 69 patients, and 13 of the 22 patients were classified as with severe pneumonia. Multivariate analysis revealed that longer operative duration (for 30 minutes increase; odds ratio 1.27, 95% confidence interval 1.01–1.51, p=0.039) and positivity for preoperative bacterial culture (odds ratio 5.03, 95% confidence interval 1.31–19.2, p=0.018) were independent risk factors for severe postoperative pneumonia, but not for all incidence of postoperative pneumonia. Of note, in only 5 out of the 22 patients with pneumonia, the same pathogen species were detected preoperatively and after the onset of pneumonia. Conclusions In conclusion, our results implied that preoperative bacterial culture may be useful to predict severe postoperative pneumonia. However, it may not be useful in determining pathogenic bacteria responsible for postoperative pneumonia.

Revocable identity-based encryption (RIBE) is an extension of IBE with an efficient key revocation mechanism. Revocable hierarchical IBE (RHIBE) is its further extension with key delegation functionality. Although there are various adaptively secure pairing-based RIBE schemes, all known hierarchical analogues only satisfy selective security. In addition, the currently known most efficient adaptively secure RIBE and selectively secure RHIBE schemes rely on non-standard assumptions, which are referred to as the augmented DDH assumption and q-type assumptions, respectively. In this paper, we propose a simple but effective design methodology for RHIBE schemes. We provide a generic design framework for RHIBE based on an HIBE scheme with a few properties. Fortunately, several state-of-the-art pairing-based HIBE schemes have the properties. In addition, our construction preserves the sizes of master public keys, ciphertexts, and decryption keys, as well as the complexity assumptions of the underlying HIBE scheme. Thus, we obtain the first RHIBE schemes with adaptive security under the standard k-linear assumption. We prove adaptive security by developing a new proof technique for RHIBE. Due to the compactness-preserving construction, the proposed R(H)IBE schemes have similar efficiencies to the most efficient existing schemes.

Revocation functionality is vital to real-world cryptographic systems for managing their reliability. In the context of identity-based encryption (IBE), Boldyreva, Goyal, and Kumar (ACM CCS 2008) first showed an efficient revocation method for IBE, and such an IBE scheme with the scalable revocation method is called revocable IBE (RIBE). Seo and Emura (PKC 2013) introduced a new security notion, called decryption key exposure resistance (DKER), which is a desirable security notion for RIBE. However, all existing RIBE schemes that achieve adaptive security with DKER require long public parameters or composite-order bilinear groups. In this paper, we first show an RIBE scheme that (1) satisfies adaptive security; (2) achieves DKER; (3) realizes constant-size public parameters; and (4) is constructed over prime-order bilinear groups. Our core technique relies on Seo and Emura's one (PKC 2013), which transform the Waters IBE (EUROCRYPT 2005) to the corresponding RIBE scheme. Specifically, we construct an IBE scheme that satisfies constant-size public parameters over prime-order groups and some requirements for the Seo-Emura technique, and then transform the IBE scheme to an RIBE scheme. We also discuss how to extend the proposed RIBE scheme to a chosen-ciphertext secure one and server-aided one (ESORICS 2015).

The tumor microenvironment (TME) plays a key role in the efficacy of neoadjuvant chemotherapy (NAC) in solid tumors including esophageal squamous cell carcinoma (ESCC). However, the TME profile of ESCC treated with NAC is not fully understood. In this study, we investigated the effect of NAC on the TME especially tumor-associated macrophages (TAM), the important immunosuppressive components of the TME, in ESCC. We quantified the expression of CD163, a crucial marker of TAM, in pretherapeutic biopsy and surgically resected ESCC specimens from patients who received NAC (n = 33) or did not receive NAC (n = 12). We found that NAC dramatically increased the expression of CD163 on TAMs in ESCC. Colony-stimulating factor 1 (CSF-1) and IL34 are crucial cytokines that recruit monocytes into tumor sites and differentiate them into TAMs. Interestingly, NAC significantly upregulated the expression of IL34 but not CSF-1 on tumor cells, and the frequencies of CD163+ TAMs were significantly correlated with IL34 expression in ESCC after NAC. The expression of IL34 in NAC-nonresponsive patients was significantly higher than that in NAC-responsive patients, and patients with IL34-high ESCC exhibited worse prognosis as compared with patients with IL34-low ESCC. We also demonstrated that 5-fluorouracil (5-FU)/cisplatin preferentially increased mRNA expression of IL34 on human ESCC cell lines. Human peripheral blood monocytes co-cultured with ESCC cells treated with 5-FU/cisplatin increased the expression of CD163, which was attenuated by the treatment with CSF-1R inhibitors. These data suggest that IL34 expression by NAC shifts the TME toward CD163+ TAM-rich immunosuppressive and chemo-insensitive microenvironment in ESCC. Implications: The blockade of IL34 signaling may offer a novel therapeutic strategy against chemoresistance in ESCC by inhibiting M2-TAM polarization.

Sporadic cases of rheumatoid nodules (RNs) in the lung during treatment with tumour necrosis factor (TNF) inhibitors have been reported, but no treatment has been established. Here, we report a case of symptomatic lung RNs refractory to abatacept (ABT) and intravenous cyclophosphamide (IVCY) that improved with tofacitinib (TOF) treatment. A 75-year-old Japanese woman with a 10-year history of rheumatoid arthritis (RA) presented with a cough and haemoptysis during treatment with etanercept (ETN). Radiographic examinations revealed multiple nodules that were diagnosed as lung RNs via biopsy. The ETN was discontinued and ABT followed by IVCY was introduced; however, neither was sufficiently effective against the lung RNs. Thereafter, TOF was started and the lung RNs improved rapidly. The precise mechanisms that induce RNs during treatment with TNF inhibitors are unknown. Cytokines (IL-23 and IL-6) are suspected to be involved. TOF may be a reasonable strategy for treating symptomatic lung RNs.

To determine the clinical characteristics of methotrexate-associated lymphoproliferative disorder (MTX-LPD).In this study, 12 RA patients who developed MTX-LPD were assessed. The peripheral blood lymphocyte (PBL) count at the onset of MTX-LPD was compared to that 6 months before the onset, in Epstein-Barr virus-encoded RNA (EBER)-positive and -negative subgroups. We examined the change in the PBL count after MTX withdrawal. In patients with relapsed LPD, changes in the PBL count before relapse were also examined.Regression of LPD after MTX withdrawal was noted in eight patients. In these patients, the PBL count was decreased at the onset of MTX-LPD compared to 6 months before the onset; the decrease was significantly more prominent in EBER-positive patients. In cases of spontaneous regression of LPD, the PBL count recovered quickly after MTX withdrawal. Four of eight patients showed a recurrence of LPD after they improved following MTX withdrawal. These patients also exhibited a decreased PBL count at recurrence compared to 6 months before recurrence.A decrease in the PBL count might be involved in the pathogenesis of MTX-LPD, especially in EBER-positive cases and in patients with LPD relapse after MTX withdrawal following initial improvement.

Background Proximal gastrectomy is a widely performed procedure that has become more common with an increasing number of proximal gastric cancer cases. Several types of reconstructive procedures after proximal gastrectomy have been developed, and it remains controversial which procedure is the most advantageous with regard to the preservation of postoperative gastric stump function and nutritional status. In the present study, we retrospectively analyzed reconstructive procedures in a consecutive case series for proximal gastrectomy, primarily focusing on postoperative body weight maintenance, nutritional status, and gastric remnant functional preservation. Methods We enrolled 69 patients who had undergone proximal gastrectomy for gastric cancer in our institute between 2005 and 2020. Short-term complications, preservation of gastric remnant functions, nutritional status, and post-operative weight changes were compared. Results After proximal gastrectomy, the numbers of patients who underwent direct esophago-gastrostomy, jejunal interposition, double tract reconstruction, and the double flap technique were 9, 10, 14, and 36, respectively. The patients in whom the double flap technique was performed suffered no reflux esophagitis after surgery. Prevalence of gastric residual at 12 months after surgery was lowest in the double flap technique group. Moreover, the double flap technique group had a better tendency regarding post-operative changes of serum albumin ratios. Furthermore, the post-operative body weight change ratio of the double flap technique group was smallest among all groups and was significantly better than that of the double tract group. Conclusions The double flap technique after proximal gastrectomy was considered the most effective technique for reconstruction which leads to better bodyweight maintenance, and results in less reflux esophagitis.

Background In accordance with an increase of proximal gastric cancer, proximal gastrectomy came to be widely performed. Several types of reconstructive procedures after proximal gastrectomy have been developed and it is still controversial which procedure has the advantages in preservation of postoperative gastric stump function and nutritional status after proximal gastrectomy. In this study, we retrospectively analyzed reconstructive procedures in our consecutive case series for proximal gastrectomy, with particular focus on postoperative body weight maintenance, nutritional status, and gastric remnant functional preservation. Methods We enrolled 69 patients who received proximal gastrectomy for gastric cancer in our institute from 2005 to 2020. Short-term complications, preservation of gastric remnant functions, nutritional status, and post-operative weight changes were compared. Results After proximal gastrectomy, the numbers of cases receiving Direct Esophago-Gastrostomy, Jejunal Interposition, Double Tract Reconstruction, and Double Flap Technique were 9, 10, 14, and 36, respectively. Double Flap Technique cases suffered no reflux esophagitis after surgery. Prevalence of gastric residual at 12-month after surgery of Double Flap Technique was the lowest. Double Flap Technique group has better tendency in post-operative changes of serum albumin ratios. Furthermore, post-operative body weight changes ratio of Double Flap Technique was the smallest and significantly better than Double Tract at all the time points. Conclusions Double Flap Technique after proximal gastrectomy was considered as the most effective reconstruction which can maintain body weight, cause less reflux esophagitis and gastric residual.

Security and privacy are the key issues for the Internet of Things (IoT) systems. Especially, secure search is an important functionality for cooperation among users' devices and non-trusted servers. Public-key encryption with keyword search (PEKS) enables us to search encrypted data and is expected to be used between a cloud server and users' mobile devices or IoT devices. However, those mobile devices might be lost or stolen. For IoT devices, it might be difficult to store keys in a tamper-proof manner due to prohibitive costs. In this paper, we deal with such a key-exposure problem on PEKS and introduce the concept of PEKS with key-updating functionality, which we call key-updatable PEKS (KU-PEKS). Specifically, we propose two models of KU-PEKS: the key-evolution model and the key-insulation model. In the key-evolution model, a pair of public and secret keys can be updated if needed (e.g., the secret key is exposed). In the key-insulation model, the public key remains fixed while the secret key can be updated if needed. The former model makes a construction simple and more efficient than the latter. On the other hand, the latter model is preferable for practical use since a user never updates their public key. We show constructions in each model in a black-box manner. We also give implementation results on Raspberry Pi 3, which can be regarded as a reasonable platform of IoT devices.

A key exposure problem is unavoidable since it seems human error can never be eliminated completely, and key-insulated encryption is one of the cryptographic solutions to the problem. At Asiacrypt’05, Hanaoka et al. introduced hierarchical key-insulation functionality, which is attractive functionality that enhances key exposure resistance, and proposed an identity-based hierarchical key-insulated encryption (hierarchical IKE) scheme in the random oracle model. In this paper, we first propose the hierarchical IKE scheme in the standard model (i.e., without random oracles). Our hierarchical IKE scheme is secure under the symmetric external Diffie–Hellman ( $$\mathsf{SXDH}$$ ) assumption, which is a static assumption. Particularly, in the non-hierarchical case, our construction is the first IKE scheme that achieves constant-size parameters including public parameters, secret keys, and ciphertexts. Furthermore, we also propose the first public-key-based key-insulated encryption (PK-KIE) in the hierarchical setting by using our technique.

Background Upper extremity deep vein thrombosis (UEDVT) is relatively rare but cannot be negligible because it can cause fatal complications. Although it is reported that the occurrence rate of UEDVT has increased due to central venous catheter (CVC), cancer, and surgical invasion, there are still limited information for esophagectomy. The aim of this study was to evaluate the clinical factors, including CVC placement and thromboprophylaxis approach, as well as retrosternal space’s width as a predictive factor for UEDVT in patients receiving esophagectomy. Methods This study included 66 patients who underwent esophagectomy with retrosternal reconstruction using a gastric tube. All patients routinely underwent contrast-enhanced computed tomography (CT) on the 4th postoperative day. Low-molecular-weight-heparin (LMWH) was routinely administered by the 2nd postoperative day. To evaluate retrosternal space’s width, (a) The distance from sternum to brachiocephalic artery and (b) the distance from sternum to vertebra were measured by preoperative CT, and the ratio of (a) to (b) was defined as the width of retrosternal space. Results Among all patients, 11(16.7%) suffered from UEDVT, and none was preoperatively received CVC placement, while 7 were inserted in non-UEDVT cases. Retrosternal space’s width in patients with UEDVT was significantly smaller than that in patients without UEDVT (0.17 vs. 0.26; P < 0.0001). A cutoff value of the width was 0.21, which has high sensitivity (87%) and specificity (82%) for UEDVT prediction, respectively. Conclusion The existence of CVC may not affect the development of UEDVT, but preoperative evaluation of retrosternal ratio may predict the occurrence of UEDVT.

In this paper, we show the first efficient threshold public-key encryption (TPKE) scheme under the difficulty of search problems. More specifically, our TPKE scheme simultaneously achieves: (1) chosen ciphertext security (CCA security) under the computational bilinear Diffie-Hellman (CBDH) assumption in the standard model; (2) re-splittability, which is a useful property that makes partial secret keys refreshable; and (3) O(√κ )-bit ciphertexts, public keys, and secret keys, where κ is a security parameter. Most previous CCA-secure TPKE schemes rely on decisional complexity assumptions or random oracles. Although there exist CCA-secure TPKE schemes under the difficulty of search problems, all such schemes are inefficient or work over small plaintext spaces. Technically, we begin with a direct construction of a threshold identity-based key encapsulation mechanism (TIB-KEM) with a weak security notion. Then, we transform the weakly-secure TIB-KEM into a CCA-secure TPKE scheme via the tag-KEM/DEM approach.

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment play an essential role in the tumor progression of esophageal squamous cell carcinoma (ESCC). The present study aimed to investigate the expression of CAF-related molecules, versican, periostin and lumican, in cancer stroma, to provide prognostic stratification for patients with ESCC after surgery. A total of 106 patients with ESCC who underwent curative esophagectomy without preoperative chemotherapy or radiotherapy were enrolled. The expression of CAF-related stromal proteins, including versican, periostin and lumican, was examined using immunohistochemistry, and the prognostic value was assessed by Kaplan-Meier survival analysis, and univariate and multivariate Cox regression models. The expression of versican, periostin and lumican was found specifically in the stromal component of ESCC. Kaplan-Meier analysis demonstrated that, compared with a low expression level, a high expression level of versican, periostin or lumican in the cancer stroma was significantly associated with worse relapse-free survival (RFS) and overall survival times in patients with ESCC. The prognostic values of stromal versican and lumican remained significant in a stratified analysis of stage I patients. Moreover, univariate and multivariate analysis revealed that high stromal versican or lumican expression was an independent prognostic factor for RFS in the patients. The present study demonstrated that CAF-related molecules, including versican, periostin and lumican, were expressed in the stroma of ESCC, and that stromal expression of versican and lumican in particular may have clinical utility as a prognostic biomarker for poor RFS in postoperative patients with ESCC.

In this paper, we present a basic system for controlling IoT devices in remote environments with the following requirements: (1) in a situation where an operation center broadcasts information to IoT devices, e.g., wireless environment, only the designated devices can identify operations sent from the center; (2) the devices can detect manipulation of the broadcast information and hence prevents maliciously generated operations from being executed. We formalize a model of the basic system and its essential requirements and propose anonymous broadcast authentication (ABA) as its core cryptographic primitive. We formally define the syntax and security notions for ABA and show provably-secure ABA constructions.

Circulating tumor cells (CTCs) are known to be a systemic process of malignant progression of cancer cells and there is a possibility that analysis for CTCs as a liquid biopsy become predictive or prognostic tools for cancer patients. In the present study with the novel CTCs detection system (Celsee system®), we performed quantitative and qualitative analysis of CTCs in patients with esophageal squamous cell carcinoma (ESCC) receiving neoadjuvant chemotherapy (NAC) with 5FU + CDDP regimen. CTCs are defined as having both DAPI positive and CD45 negative. Vimentin-positive CTCs were defined as mesenchymal-type CTCs (M-CTCs), while epithelial-type CTCs (E-CTCs) were only positive for pan-cytokeratin. At the baseline, there are detectable amounts of CTCs in all patients (n = 30) at all stages, and there were no significant differences of total CTCs, E-CTCs, or M-CTCs numbers between stages. Of importance, among total CTCs, M-CTCs are more dominant than E-CTCs in number. Also, there was no significant change of detectable amounts and phenotype of CTCs before and after NAC (n = 24). Of note, early recurrent group indicated that there was an elevated total CTCs number before NAC and an increased M-CTCs after NAC in comparison to those in non-recurrent group. Quantitative and qualitative analysis of CTCs may provide useful complementary predictive and prognostic information in ESCC.

Gastric cancer (GC) patients with PD-L1-negative tumor occasionally have a favorable response to anti-PD-1 mAb. The aim of the present study was to investigate the regulatory mechanism and immunosuppressive role of PD-L2 in GC. We used immunohistochemistry to evaluate the expression of PD-L2 in primary tumors from 194 patients with GC. The mechanism of PD-L2 expression was assessed in TCGA stomach adenocarcinoma tissue dataset and in vitro assay using GC cell lines. The immunosuppressive role of PD-L2 was evaluated by cytotoxicity of CTL clone against PD-L2 expressing GC cells. PD-L2 was expressed on tumor cells (TCs) of 28.4% patients and PD-L2 expression on TCs was significantly associated with tumor progression. TCGA dataset revealed that IFN-γ and, to a lesser extent, IL-4 signature significantly correlated with PD-L2 expression. In vitro assay showed that IFN-γ and, also to a lesser extent, IL-4 can upregulate PD-L2 expression on GC cells. Anti-PD-L2 mAb significantly enhanced the cytotoxicity of CTL clone against GC cell lines expressing PD-L2. PD-L2 is expressed on GC cells and PD-1/PD-L2 interaction are functionally involved in anti-tumor CTL activities. PD-L2 expression should be considered when determining the optimal immunotherapy for GC.

Solute carrier (SLC) drug transporters exchange various molecules without energy from adenosine triphosphate hydrolysis, indicating an association with anticancer drug resistance. However, the expression and role of SLC transporters in malignant tumors has not yet been fully elucidated. Therefore, in the current study, the expression of SLC37A family genes was evaluated in patients with colorectal cancer (CRC), and it was revealed that SLC family 37 member 1 (SLC37A1) expression was significantly increased in tumorous tissues compared with that in non-tumorous tissues. The cases with upregulated expression of SLC37A1 by immunohistochemical staining were significantly associated with positive venous invasion and liver metastasis. Furthermore, upregulated SLC37A1 expression was associated with poor overall survival time in the present cohort. These results indicated that SLC37A1 is involved in the hematogenous metastasis of CRC. To investigate whether SLC37A1 is associated with hematogenous metastasis and glycolipid metabolism, SLC37A1 was knocked down in colon cancer cells, and the expression of sialyl Lewis A and sialyl Lewis X was observed to be decreased. In summary, upregulation of SLC37A1 was observed in patients with CRC, and was associated with poor patient outcomes and survival. To the best of our knowledge, the present study is the first to propose a key role of SLC37A1 in CRC, and additional studies are warranted to reveal the functional role of SLC37A1 in CRC development.

In modern cryptography, a secret sharing scheme is an important cryptographic primitive. In particular, Krawczyk proposed a computational secret sharing (CSS) scheme, which is a practical, simple secret sharing scheme. In this paper, we focus on a CSS scheme with timed-release functionality, which we call a timed-release computational secret sharing (TR-CSS) scheme. In TR-CSS, participants more than or equal to a threshold number can reconstruct a secret by using their shares only when the time specified by a dealer has come. Our main purpose is to realize a TR-CSS scheme in a generic and efficient way in terms of the share size. Specifically, we first introduce a model and formalization of security of TR-CSS. In addition, we propose two kinds of constructions of TR-CSS: the first one is a simple and generic construction starting from an identity-based key encapsulation mechanism (IB-KEM); the second one, which is a more efficient construction than the first one, is built using a specific IB-KEM as the underlying IB-KEM. As a result, we can regard TR-CSS as a natural extension of Krawczyk’s CSS in terms of both a model and constructions, and we finally succeed to add timed-release functionality to Krawczyk’s CSS with small overhead, which is almost optimal. Moreover, our proposal of TR-CSS is important for constructing threshold encryption and multiple encryption with timed-release functionality in a generic and efficient way. Dodis and Katz showed (i) a simple and generic construction of threshold encryption from multiple encryption; and (ii) a simple, elegant and generic construction of multiple encryption. By using TR-CSS, we can effectively apply the Dodis–Katz paradigm even in the context of timed-release security.

Highlights • Splenogonadal fusion is a malformation in which the spleen is connected to the gonad. • We report a case of Splenogonadal fusion which was incidentally detected by TAPP and this is the first report of this condition. • The potential for incidental diagnoses of Splenogonadal fusion by TAPP may be increasing. • A therapeutic strategy for incidentally detected Splenogonadal fusion is unclear, but we show one successful experience., Introduction Splenogonadal fusion (SGF) is a rare congenital malformation in which the spleen is connected to the gonad. Few SGF cases have been reported in the English scientific literature, and we are unaware of any previous case reports of SGF with inguinal hernia by laparoscopic transabdominal preperitoneal hernia repair (TAPP). Here, we report a case of SGF that was incidentally detected during a TAPP procedure, with an uneventful postoperative course without complications. Presentation of case A 76-year-old male presented with a 10-year history of left inguinal swelling. He was diagnosed with a left inguinal hernia, and we performed TAPP. Laparoscopy revealed the left inguinal hernia and two reddish-purple masses, one located close to the left inguinal ring. A cord of soft tissue extended cranially from the mass to the spleen, and passed through the left internal inguinal ring caudally. We cut the cord for mesh placement and to make an accurate diagnosis of the mass. Pathological and intraoperative findings indicated a diagnosis of continuous SGF. Discussion We observed two important clinical issues in this case. First, the potential for incidental diagnoses of SGF may be increasing. Second, to our knowledge, this is the first case report of a patient with SGF identified by TAPP. Such a therapeutic strategy for incidentally detected SGF has not been described; here we report a successful experience. Conclusion To our knowledge, this is the first report of a patient with SGF diagnosed by a TAPP procedure. The postoperative course was uneventful using our method.

The key escrow problem is one of the main barriers to the widespread real-world use of identity-based encryption (IBE). Specifically, a key generation center (KGC), which generates secret keys for a given identity, has the power to decrypt all ciphertexts. At PKC 2009, Chow defined a notion of security against the KGC, that relies on assuming that it cannot discover the underlying identities behind ciphertexts. However, this is not a realistic assumption since, in practice, the KGC manages an identity list and hence it can easily guess the identities corresponding to given ciphertexts. Chow later closed the gap between theory and practice by introducing a new entity called an identity-certifying authority (ICA) and proposed an anonymous key-issuing protocol. Essentially, this allows the users, KGC, and ICA to interactively generate secret keys without users ever having to reveal their identities to the KGC. Unfortunately, the proposed protocol did not include a concrete security definition, meaning that all of the subsequent works following Chow lack the formal proofs needed to determine whether or not it delivers a secure solution to the key escrow problem.

Private operations (private permutations) were independently introduced by Nakai et al. and Marcedone et al. for implementing card-based cryptographic protocols efficiently. Recently, Nakai et al. showed that, if the private operations are available, secure computations of AND and OR operations for two inputs can be realized simultaneously by using four cards, and the protocol is applied to four-card majority voting protocol with three inputs. In this paper, it is shown that only three cards are sufficient to construct the majority voting protocol with three inputs. Specifically, we propose two constructions of three-input majority voting protocols. First, assuming that players are allowed to announce their outputs, we show that one card can be reduced from Nakai et al.’s protocol without any additional private operations and communications. Our second construction requires two more private operations and communications, whereas it removes the assumption on announcement from the first construction.

Public-key encryption with keyword search (PEKS) enables us to search over encrypted data, and is expected to be used between a cloud server and users’ devices such as laptops or smartphones. However, those devices might be lost accidentally or be stolen. In this paper, we deal with such a key-exposure problem on PEKS, and introduce a concept of PEKS with key-updating functionality, which we call key-updatable PEKS (KU-PEKS). Specifically, we propose two models of KU-PEKS: The key-evolution model and the key-insulation model. In the key-evolution model, a pair of public and secret keys can be updated if needed (e.g., the secret key is exposed). In the key-insulation model, a public key remains fixed while a secret key can be updated if needed. The former model makes a construction simple and more efficient than the latter model. On the other hand, the latter model is preferable for practical use since a user never updates his/her public key. We show constructions of a KU-PEKS scheme in each model in a black-box manner. We also give an experimental result for the most efficient instantiation, and show our proposal is practical.

Homeobox A (HOXA) cluster genes, members of the HOX family, perform an important role in normal organ development. It has previously been reported that HOXA gene expression in various types of cancer is associated with poor patient outcomes. However, the role of HOXA genes, as well as their expression, in colorectal cancers (CRC) remains unknown. Therefore, the present study investigated HOXA gene expression in patients with CRC and revealed that HOXA9 expression was significantly increased in tumor tissues compared with non-tumor tissues. Additionally, the functional role of HOXA9 was assessed by knocking down the HOXA9 gene in CRC cells and by evaluating cell growth. Regarding gene expression, cases with positive HOXA9 expression (as detected by immunohistochemical staining) were significantly associated with higher TNM stage and positive lymph node metastasis, although no association was observed between increased HOXA9 levels and the rate of overall survival in the present cohort. Regarding the functional role, HOXA9 expression was demonstrated to be upregulated in patients with CRC and was associated with lymph node metastasis.

Kinesin family member 4A (KIF4A) is a member of the kinesin 4 subfamily of kinesin-related proteins and serves an important role in cell division. The expression levels of KIF4A have been investigated in numerous types of cancer, including cervical, lung, oral, and breast cancer, and are established to be associated with poor patient prognosis. However, the role of KIF4A, as well as its expression in colorectal cancer (CRC), remains to be elucidated. Therefore, the current study investigated KIF4A expression levels in patients with CRC and demonstrated that its levels were increased in tumor tissues compared with non-tumor tissues. To investigate the functional role of KIF4A, KIF4A was knocked down in CRC cells and cell viability was evaluated. CRC cells with KIF4A knockdown exhibited lower cell proliferation compared with control cells. In addition, KIF4A expression levels, as determined by immunohistochemistry, were compared with the expression of Ki-67, but no significant associations were observed in the patients with CRC. Therefore, KIF4A was found to be upregulated in patients with CRC and downregulation of KIF4A reduced cell proliferation in CRC cells. These results suggest that KIF4A may be a potential therapeutic target, which may improve the outcomes of patients with CRC.

Searchable symmetric encryption (SSE) enables us to search encrypted data with an arbitrarily chosen keyword without leaking information on the data and keyword. SSE is expected to be used in, for example, cloud computing and genome analyses. In particular, privacy of genome data must be guaranteed for long periods, and therefore unconditionally secure cryptographic protocols, rather than computationally secure ones, should be used for protecting genome data. For this reason, we propose new constructions of unconditionally secure SSE schemes in this paper. Specifically, we define a model and security of unconditionally secure SSE, and we show a lower bound on secret-key sizes. We propose two kinds of constructions of unconditionally secure SSE schemes: One is asymptotically optimal in the sense of the secret-key size with some restriction on the security definition; and the other achieves full security at the sacrifice of the secret-key size.

Coherent phonon (CP) generation in an undoped Si crystal is theoretically investigated to shed light on unexplored quantum-mechanical effects in the early-time region immediately after the irradiation of ultrashort laser pulse. One examines time signals attributed to an induced charge density of an ionic core, placing the focus on the effects of the Rabi frequency $\Omega_{0cv}$ on the signals; this frequency corresponds to the peak electric-field of the pulse. It is found that at specific $\Omega_{0cv}$'s where the energy of plasmon caused by photoexcited carriers coincides with the longitudinal-optical phonon energy, the energetically {\it resonant } interaction between these two modes leads to striking anticrossings, revealing irregular oscillations with anomalously enhanced amplitudes in the observed time signals. Also, the oscillatory pattern is subject to the Rabi flopping of the excited carrier density that is controlled by $\Omega_{0cv}$. These findings show that the early-time region is enriched with quantum-mechanical effects inherent in the CP generation, though experimental signals are more or less masked by the so-called coherent artifact due to nonlinear optical effects., Comment: 5 pages, 4 figures

Revoking corrupted users is a desirable functionality for cryptosystems. Since Boldyreva, Goyal, and Kumar (ACM CCS 2008) proposed a notable result for scalable revocation method in identity-based encryption (IBE), several works have improved either the security or the efficiency of revocable IBE (RIBE). Currently, all existing scalable RIBE schemes that achieve adaptively security against decryption key exposure resistance (DKER) can be categorized into two groups; either with long public parameters or over composite-order bilinear groups. From both practical and theoretical points of views, it would be interesting to construct adaptively secure RIBE scheme with DKER and short public parameters in prime-order bilinear groups.

Sequential aggregate signature (SAS) schemes provide a single, compact signature, which is generated from a number of signatures, that simultaneously ensures that each signature is legally generated from the corresponding message with a defined order. Although SAS schemes have various applications such as a secure border gateway protocol, all existing schemes are computationally secure (i.e., assuming computationally bounded adversaries). In this paper, we first propose sequential aggregate authentication codes (SAA-codes), which has similar functionality of SAS in the information theoretic security setting. Specifically, we give a model and security formalization of SAA-codes, derive lower bounds on sizes of secret keys and authenticators required in secure SAA-codes, and present two kinds of optimal constructions in the sense that each construction meets the lower bounds with equalities.

Key-insulated encryption is one of the effective solutions to a key exposure problem. Recently, identity-based encryption IBE has been used as one of fundamental cryptographic primitives in a wide range of various applications, and it is considered that the identity-based key-insulated security has a huge influence on the resulting applications. At Asiacrypt'05, Hanaoka et al. proposed an identity-based hierarchical key-insulated encryption hierarchical IKE scheme. Although their scheme is secure in the random oracle model, it has a "hierarchical key-updating structure," which is attractive functionality that enhances key exposure resistance. In this paper, we first propose the hierarchical IKE scheme without random oracles. Our hierarchical IKE scheme is secure under the symmetric external Diffie---Hellman SXDH assumption, which is known as the simple and static one. Furthermore, when the hierarchy depth is one i.e. not hierarchical case, our scheme is the first IKE scheme that achieves constant-size parameters including public parameters, secret keys, and ciphertexts.

Data stored in cloud storage sometimes requires long-term security due to its sensitivity (e.g., genome data), and therefore, it also requires flexible access control for handling entities who can use the data. Broadcast encryption can partially provide such flexibility by specifying privileged receivers so that only they can decrypt a ciphertext. However, once privileged receivers are specified, they can be no longer dynamically added and/or removed. In this paper, we propose a new type of broadcast encryption which provides long-term security and appropriate access control, which we call unconditionally secure revocable-storage broadcast encryption (RS-BE). In RS-BE, privileged receivers of a ciphertext can be dynamically updated without revealing any information on the underlying plaintext. Specifically, we define a model and security of RS-BE, and derive tight lower bounds on sizes of secret keys required for a one-time secure RS-BE scheme when the ciphertext size is equal to the plaintext size. Our lower bounds can be applied to traditional broadcast encryption. We then construct a one-time secure RS-BE scheme with a trade-off between sizes of ciphertexts and secret keys, and our construction for the smallest ciphertext size meets all bounds with equalities. Furthermore, to detect an improper update, we consider security against modification attacks to a ciphertext, and present a concrete construction secure against this type of attacks.

We sought to determine whether a clinical association exists between osteoarthritis (OA)-associated knee pain and adenosine triphosphate (ATP) levels in synovial fluid (SF). A total of 28 patients with 28 primary OA knees were included. They routinely received intra-articular injection of high-molecular-weight hyaluronic acid (HA) once weekly for 5 weeks (treated group). Eight patients without knee pain who had undergone an operation for anterior or posterior cruciate ligament reconstruction 2 years ago were also examined (control group). SF and blood ATP concentrations, total amount of ATP, total SF volume, and Visual Analogue Scale (VAS) scores in all patients were measured and we compared pre-treatment values with those 1 week after the final treatment. We evaluated the correlation of change in total ATP (ΔATP) and change in VAS score (ΔVAS), ΔVAS and change in SF volume (ΔSF), and ATP concentration in SF and blood. In the treated group, SF ATP concentration, total amount of ATP, SF volume, and VAS score were all significantly lower post-treatment than pre-treatment (p = 0.0005, 0.0003, 0.0022, and < 0.0001, respectively). In treated group, ΔVAS was significantly associated with ΔATP (r = 0.56, p = 0.0032), ΔSF was significantly associated with ΔVAS (r = 0.78, p < 0.0001), and total amount of SF ATP and SF volume at pre-treatment were significantly higher than the control group (p < 0.0001, p < 0.0001) We demonstrated an association between SF ATP level changes and OA knee pain, which should facilitate a further understanding of OA pain mechanisms.

【目的】アレルギー疾患を有する小児が東日本大震災によってどのような影響を受けたかを調査し，今後の対応を検討する． 【対象と方法】対象は，宮城県立こども病院総合診療科，仙台医療センター小児科，森川小児科アレルギー科を定期受診した402名のアレルギー疾患の小児の保護者．口頭で同意を得た後，外来の待ち時間にアンケート記入を行い，診察時に回収した． 【結果】困った事で最も多かった回答は，それぞれ，気管支喘息では「停電のため電動式吸入器が使用できなかった」，アトピー性皮膚炎では「入浴できず湿疹が悪化した」，食物アレルギーでは「アレルギー用ミルクやアレルギー対応食品を手に入れるのが大変だった」であった． 【まとめ】大震災に対する今後の対応として，気管支喘息では停電の時でも吸入できるような吸入薬や吸入器の備え，アトピー性皮膚炎では入浴できない時のスキンケアの指導，食物アレルギーではアレルギー用ミルクを含めたアレルギー対応食品の備蓄や避難所などの公的機関で食物アレルギーへの理解を深める啓蒙活動が必要と考えた．

Rationale: Colonoscopy has been used for screening and treatment of diseases worldwide. Endoscopic mucosal resection (EMR) has many major complications such as colon perforation and bleeding. However, cases of minor complications have also been reported. Here, we present a case of massive retroperitoneal hematoma, as a minor complication, after colonoscopy. Patient concerns: A 57-year-old man was admitted to our hospital because of abdominal pain. He had no past medical history relating to his present condition, and he received EMR at another hospital 11 days before his admission. Dynamic computed tomography (CT) was performed, which showed a massive retroperitoneal hematoma near the third portion of the duodenum. Diagnosis: The patient had a superior mesenteric vein injury after the colonoscopy. Outcomes: The patient did not complain of nausea or vomiting and was discharged after 43 days. Lessons: Although massive retroperitoneal hematoma is a minor complication after colonoscopy, it can be life threatening; thus, we need to know more about this complication. Dynamic CT may be useful in detecting whether the bleeding occurs from the artery or not.

Many behavioral processes are under circadian regulation in almost all organisms from bacteria to mammals. Although substantial evidences support the idea that circadian clock could modulate the efficacy of anticancer therapy, the mechanism(s) has not been clear. Here we demonstrated that expression of topoisomerase I (top1) mRNA and its promoter activity underwent circadian oscillation after serum-rich medium treatment in HCT 116 cells. Moreover, the formation of cleavage complex composed of top1 and top1 poison, camptothecin (CPT), detected by nicking assay was also oscillated. Colony formation assay indicated that cytotoxicity of 8h-CPT treatment was significantly higher at 4-h after serum-shock than at 20-h (p = 0.0289). In addition, dexamethasone treatment also induced circadian rhythm of top1 in HCT 116 cells. These results raise the possibility that the circadian rhythm of top1, which would be induced by some types of drugs such as dexamethasone, could be considered for chemotherapy in clinic.

症例は71歳の女性で，食欲不振，胸部不快感およびタール便を主訴に前医を受診し，胃潰瘍と幽門狭窄および著明な貧血を認め当科紹介となった．上部消化管造影検査では縦隔内に胃前庭部から十二指腸の縦隔内への脱出を認め，腹部CTでは膵頭部までもが縦隔内に脱出していた．上部消化管内視鏡検査の後症状の軽快があり内科的加療を行っていたが，胃潰瘍は難治性であった．経過中に肝機能障害を来しため行ったDIC-CTにて胆管の狭窄と末梢胆管の拡張を認めた．胃前庭部，十二指腸および膵頭部の傍食道裂孔ヘルニア嵌頓による胆道狭窄および難治性胃潰瘍の診断にて開腹手術を行った．開大した食道裂孔へ胃前庭部，十二指腸および膵頭部が嵌頓しており，整復後ヘルニア門を縫縮し閉鎖した．術後経過は良好で第12病日に退院し，術後30か月経過した現在も肝機能障害を認めず，上部消化管内視鏡検査上も胃食道逆流症および胃潰瘍再発を認めていない．

症例は55歳男性で，顔面·体幹の皮膚結節の増大を主訴に当院を受診された．それぞれの皮膚結節に対して，切除術が施行され脂腺腺腫および脂腺癌の診断となった．34歳時を初回手術とする3回の大腸癌手術歴があり，内臓悪性腫瘍と脂腺系皮膚腫瘍の合併からMuir-Torre症候群（MTS）の診断となった．Microsatellite Instability（MSI）検査を行いMSI-highと診断され，遺伝子解析にてhMSH2 の胚細胞変異が認められた．免疫組織染色を加え，大腸癌および皮膚腫瘍ともにMSH2蛋白の欠失が確認できた．今回の結果より，免疫組織染色のミスマッチ修復遺伝子の大規模スクリーニングへの代用の可能性が示唆された．これまでの本邦報告例を含めて文献的考察を加え報告する．

Chronotherapy is one of the most active treatment schedule, based on the adjustment of drug delivery to the 24-hour rhythms generated by circadian rhythm. The aim of this study is to confirm that the efficacy of 5-fluorouracil (5-FU) is dependent on circadian rhythm, using Walker-256 xenografted rat. The present study demonstrated that tumor developed more rapidly at night rather than at day. Moreover, the administration of 5-FU at night was more effective rather than that at day. Furthermore, the microvessel count by immunohistochemical staining of endothelial cells revearled that tumors treated with 5-FU at night contained significantly less microvessels than those at day. In conclusion, our present data suggested that chronotherapy would contribute to the improvement of chemotherapy in patients with some population of malignancy through the control of angiogenesis.

Neurosurgeons sometimes find it difficult to locate tumors precisely during microsurgery, particularly tumors located in the brain parenchyma because of the absence of boundaries in this region. Image-guided neurosurgical techniques conducted with the help of neuronavigation systems have been developed and have gained importance recently. Accuracy is vital during image-guided neurosurgery. We used a phantom to evaluate the errors introduced during navigation. The three errors evaluated were skin-shift, marker-gap, and table-rotation errors. The skin-shift error occurs if the fiducial markers positioned on the scalp move when the head is fixed to a head holder with head pins. The marker-gap error occurs when the marker ball is positioned incorrectly in the marker socket. The table-rotation error occurs when the operating table is rotated for obtaining an intraoperative MR image and then returned to its original position. Our results indicated that skin shift decreased the navigation accuracy by an error of more than 4 mm, and the gap between the marker ball and the socket resulted in a decrease in navigation accuracy by an error of more than 5 mm. The table-rotation error was found to be negligible. The errors can be avoided by ensuring that the fiducial markers are positioned appropriately on the scalp and the marker ball is fitted well in the marker socket. A phantom is useful for evaluating accuracy, particularly for evaluating errors intrinsic to different operating rooms. Periodic quality assurance by use of a phantom in each operating room might aid in maintaining the accuracy of neuronavigation.