Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is widely used to obtain tissues for diagnosis of pancreatic diseases. Because there is a risk of dissemination, few needle passes and increased diagnostic yield are desired. This study evaluated the frequency and clinicopathological significance of p53 protein overexpression in pancreatic ductal adenocarcinoma (PDAC) using EUS-FNA specimens. Of the 90 patients who underwent EUS-FNA at Showa University Fujigaoka Hospital between 2014 and 2016, paraffin-embedded sections of biopsy specimens of 50 patients (25 men and 25 women) with PDAC were subjected to p53 immunohistochemical staining. The cases were classified into two groups according to the percentage of p53-positive cells: p53-positive group with more than 10% cells and p53-negative group with less than 10% cells. The clinicopathological features of these groups were compared using statistical analysis. A heterogeneous but distinct positive staining (p53 protein overexpression) of p53, indicating p53 gene mutation, was found in 42 (84%) of 50 cases, and 39 cases belonged to the p53-positive group and 11 were in the p53-negative group. Between the two groups, there were no significant differences in the investigated clinicopathological features, such as gender, age, tumor diameter, locations, histological differentiation, serum tumor marker values, lymph node metastasis, distant metastasis, stage, and outcome. However, in the p53-negative group, the tumor tended to more frequently occur in body to tail, show poor differentiation, and have lower serum tumor marker values. An additional KRAS gene test showed codon12 mutations in all cases (n=7) investigated for p53-negative group. In this study, p53 protein overexpression was frequently identified on EUS-FNA specimens and seemed to be extremely useful in the diagnosis of PDAC. In addition, KRAS testing of EUS-FNA in combination with p53 immunostaining may improve the diagnostic accuracy for PDAC. Our data did not find a significant correlation between the p53 expression status and any clinicopathological feature, therefore further accumulation studies are recommended.

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We examined whether a transient re-conduction after rapid infusion of ATP following successful ablation of accessory pathway (AP) is an indicator as a recurrence predictor of a chronic term. Subjects were 48 patients with manifest Wolf-Parkinson-White (WPW) syndrome who had successful ablation and ATP bolus injection. Thirty-two of APs were located on the left side and ablated at the ventricle. Sixteen were located on the right side and ablated at the atrium. All of APs were completely ablated. After ablation, ATP injection showed temporal re-conduction antegradely in one left-side AP and in 4 right-side APs. Delta wave reappeared in 4 of the right APs in chronic term but in none of left-side APs. Only one patient of 4 right-side APs had temporal retrograde re-conduction. These re-conductions were shown in 3 of right-side APs by ATP alone, and in one each of the right and the left APs by ATP with isoproterenol. Furthermore, the right-side APs were susceptible to re-conduction by nicorandil. Adenosine makes an abundance of Ach-sensitive K channels open in atrium which makes the refract period shorten and/or the resting potential deeper resulting in improvement of conduction. Thus, bolus ATP injection facilitates clear re-conduction from temporal block in the acute phase. Dormant conduction by ATP is useful to predict a chronic recurrence of the AP conduction after catheter ablation at the atrium.

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Total elbow arthroplasty is achieving good long-term results due to improvements in implant designs and surgical techniques. However, some cases require revision surgery due to loosening. The purpose of this study was to compare and evaluate the biomechanical stress distribution within bone tissues and bone cement surrounding the short- and long-stem ulnar components of unlinked total elbow prostheses, and to determine which component is more likely to cause loosening. Quasi-statically changed scenarios of a post-arthroplasty elbow (Kudo elbow) undergoing flexion-extension motion while holding a 1-kg hand weight were generated on a computer. The minimum muscle forces needed to maintain the limb position were determined for each elbow angle. A finite element model of the ulna, ulnar components and bone cement, consisting of tetrahedral primary elements, was created using 3D-CAD software. Stress distribution in the ulna was assessed, and the maximum stress that occurred at each elbow angle was compared between the short (45mm) and long stems (65mm). Maximum stress occurred at the structures surrounding the stem tips. The highest maximum stresses in the elbow joint during flexion-extension motion occurred at 110 degrees of flexion for the short stem and 70 degrees for the long stem. The maximum stress was higher in the short stem at all of the elbow angles tested, with the exception of 30 degrees. The distribution of maximum stress in this study was correlated with the site where clinical loosening occurs. This study suggests that the short stem places more stress upon the adjacent structures throughout the flexion-extension motion of the elbow joint and therefore, may lead to loosening.

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Oxidative stress responses are well known to play important roles in the development of pregnancy-related complications. However, there is little information on the relationship between oxidative stress responses and pregnancy. The present study, therefore, was undertaken to examine the influence of pregnancy on the development of oxidative stress responses. Healthy women with singleton pregnancies, who were free of pregnancy complications and chronic illnesses, were divided into four groups; first, second, third trimesters and 1-month postpartum. Urine samples were obtained from pregnant women and non-pregnant healthy controls, and the levels measured of the following oxidative stress markers were measured: Isoprostane, Hexanoy-Lysine, 8-OHdG and Biopyrrin by ELISA. Urine samples obtained from the third trimester contained significantly higher levels of oxidative stress markers than those from non-pregnant , first, and second trimesters. The urinary levels of, Isoprostane, Hexanoy-Lysine, 8-OHdG and biopyrrin in urine significantly decreased 1-month postpartum as compared with those from the third trimester.

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Using a human breast cancer cell line MDA-MB-231 cells, we examined the roles of microRNAs (miRs) in the regulation of p21, a cyclin-dependent kinase inhibitor, and the resistance to cisplatin and tubulin inhibiting anti-cancer drugs such as eribulin and paclitaxel. MDA-MB231 cells were separated into two subpopulations by the surface antigen CD44, a potential marker for cancer stem-like cells. The level of p21 protein expression was higher in CD44⁺ than in CD44^-. Exposure of MDA-MB-231 cells to the above drugs led to increases in p21 protein. However, the level of p21 in CD44⁺ isolated after exposure to cisplatin was significantly lower than CD44^-, suggesting that p21-dependent cell cycle suppression was blunted in CD44⁺ compared with CD44^-. The oxidation rate of glutathione in CD44⁺ isolated after cisplatin treatment was much lower than that in CD44^-, indicating that cisplatin induces much weaker oxidative cytotoxicity to CD44⁺ than to CD44^-. Moreover, caspase-3 activity in CD44⁺ isolated after exposure to cisplatin was significantly lower than that in CD44^-, indicating that CD44⁺ is more resistant to cisplatin-induced apoptosis. To explore the roles of miRs in the expression of p21, MDA-MB-231 cells were treated with various miR inhibitors followed by isolation of CD44⁺. Among them, inhibitors for miR-17 and miR-93 increased the expression of p21 in CD44⁺, suggesting that p21 expression is suppressed by miR-17 and miR-93. Thus, the current study demonstrated that expression of CD44 is associated with drug resistance to cisplatin in MDA-MB231 cells. It was also suggested that miR-17 and miR-93 serve as inhibitors for p21, a factor involved in drug resistance.

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Shear stress-induced nitric oxide (NO) production in vascular endothelial cells is reported to be mediated by the release of ATP and autocrine activation of purinergic P2 receptors, which have seven P2X and eight P2Y subtypes. In bovine aortic endothelial cells (BAECs), the expression of P2X₄, P2X₇, P2Y₁ and P2Y₂ subtypes has been reported. In the present study, we examined which particular subtypes are involved in the NO release from cultured BAECs. The amount of NO released from the NO donor NOR-1 or BAECs into the HEPES-buffered Krebs solution was measured by HPLC fluorometry using DAF-FM, which reacts with NO to form the fluorescent triazole derivative DAF-FMT. A linear relationship (r²=0.998) was observed between the concentration of NOR-1 (0〜200nM) and the fluorescence intensity of DAF-FMT. When BAECs were stimulated with ATPγS (a nonhydrolyzable ATP analog; 0〜10μM) for 60 min at 37°C, the amount of NO released was increased in a concentration-dependent manner. Such an increase was not observed in the presence of L-NMMA (a NO synthase inhibitor). PPADS (a non-selective P2X antagonist) and 5-BDBD (a selective P2X₄ antagonist) inhibited the ATPγS (3μM)-induced NO production with an IC₅₀ of 5.8μM and 1.2μM, respectively. These IC₅₀ values were similar to those found in previous reports. On the other hand, the inhibitory actions of reactive blue 2 (a non-selective P2Y antagonist) and A438079 (a selective P2X₇ antagonist) against ATPγS-induced NO production were less potent than in previous reports. These results suggest that the P2X₄ subtype is mainly involved in the ATPγS-induced NO production in BAECs.

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Papillary squamous cell carcinoma is a rare variant of squamous cell carcinoma. The predominant occurrence sites are the larynx, oropharynx and nasopharynx. We report a case of papillary squamous cell carcinoma of the buccal mucosa. A 76-year-old-man with the complaint of tumor of the left buccal mucosa was referred to our center. Intraoral examination showed a 30×20mm-sized well-circumscribed, papillary, elastic hard mass of the left buccal mucosa. No metastasis of the neck lymph nodes was detected. CT demonstrated a mass sized 28×16mm at the left buccal mucosa. MRI revealed no invasion of the tumor to the buccinator muscle. The patient underwent resection of buccal mucosal carcinoma. There was no evidence of recurrence 2 years after surgery.

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