Effect of the XIAP inhibitor Embelin on TRAIL-induced apoptosis of pancreatic cancer cells

BACKGROUND: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent inducer of apoptosis in a wide variety of tumor cells, while it has no toxicity for the majority of normal cells.Therefore, TRAIL may be a suitable agent for anticancer therapy. We previously reported that a number of pancreatic cancer cell lines show resistance to TRAIL-induced apoptosis via overexpression of XIAP and FLIP. The present study was conducted to further examine TRAIL-based therapeutic strategies by aiming to restore functional apoptotic pathways in resistant pancreatic cancer cells. METHODS: In various pancreatic cancer cell lines, TRAIL-induced apoptosis was evaluated in the presence or absence of an XIAP-inhibitor (Smac peptide). Second, TRAIL-induced apoptosis was evaluated in TRAIL-resistant AsPC-1 cells with or without FLIP antisense. Third, the combined effect of Smac peptide and FLIP antisense was tested, and the activation of apoptosis-related caspases and poly (ADP-ribose) polymerase was evaluated. Finally, TRAIL-induced apoptosis was evaluated in the presence or absence of FLIP antisense and an XIAP inhibitor (embelin). RESULTS: Smac peptide enhanced TRAIL-induced apoptosis in a dose-dependent manner for several pancreatic cancer cell lines, but showed no effect on TRAIL-resistant AsPC-1 cells. Smac peptide alone had no influence on cell viability. TRAIL-induced apoptosis was restored in TRAIL-resistant AsPC-1 cells by exposure to FLIP antisense, which suppressed the expression of FLIP. The effect of TRAIL was augmented by the combination of FLIP antisense and Smac peptide. Similarly, TRAIL-induced apoptosis was restored by the combination of FLIP antisense and embelin. Activation of apoptotic caspases and cleavage of poly (ADP-ribose) polymerase was observed after sensitization of TRAIL-resistant pancreatic cancer cells. CONCLUSIONS: Pancreatic cancer cells gain resistance to TRAIL-induced apoptosis via expression of the antiapoptotic proteins XIAP and FLIP. Smac peptide and FLIP antisense could restore the apoptotic effect of TRAIL. An XIAP inhibitor, embelin, enhanced the effect of TRAIL in the presence of FLIP antisense. These findings may provide useful information for the development of TRAIL-based therapeutic strategies by restoring functional apoptotic pathways in resistant pancreatic cancer cells. In addition, a low molecular weight XIAP inhibitor like embelin could be a lead compound for the development of effective XIAP inhibitors.     

Orthogonal antibody testing for COVID-19 among healthcare workers in a non-epidemic place and time: Japan’s Iwate Prefecture,May 18-31, 2020

Of the 47 prefectures in Japan, Iwate had the fewest cases of coronavirus disease 2019 (COVID-19), with the first diagnosis officially confirmed on July 28, 2020. A baseline serological survey of COVID-19 antibodies is essential to accurately evaluate an epidemic outbreak. The primary purpose of this study was to determine pre-epidemic prevalence of COVID-19 antibodies among healthcare workers, using two laboratory-based quantitative tests. In addition, a point-of-care (POC) qualitative test, rapid, simple, and convenient for primary care clinics, was compared with the laboratory-based tests. All antibody tests were performed on serum from 1,000 healthcare workers (mean age, 40 ± 11 years) in Iwate Prefectural Central Hospital, May 29-31, 2020. A COVID-19 case was defined as showing positive results in both laboratory-based quantitative tests. None of 1,000 samples had positive results in both of the laboratory immunoassays. The POC test showed positive results in 33 of 1,000 samples (3.3%) (95% confidence interval: 2.19-4.41), but no samples were simultaneously positive in both laboratory-based tests. In conclusion, COVID-19 cases were not serologically confirmed by a baseline control study of healthcare workers at our hospital in late May, 2020. Moreover, the POC qualitative test may offer no advantage in areas with very low prevalence of COVID-19, due to higher false-positive reactions compared with laboratory-based quantitative immunoassays.     

Mechanistic Study of the Oxidative Degradation of the Triazole Antifungal Agent CS-758 in an Amorphous Form

In this study, the degradates generated from a pharmaceutical solid were characterized, and a mechanistic pathway underlying their formation was proposed. The chemical stability of a novel triazole antifungal drug, CS‐758, deteriorated significantly when the crystal was disordered, and characteristic degradates were generated. A total of eight degradates in solution and nine degradates in a solid state were isolated by preparative liquid chromatography. Degradates were characterized using high‐performance liquid chromatography–photodiode array, mass spectrometry, and nuclear magnetic resonance. Radical‐mediated oxidation is proposed as the main degradation pathway in the solid state. The initiation step of this pathway is hydrogen atom abstraction from a methine carbon that is adjacent to a dien moiety and the formation of a delocalized vinylic radical intermediate. Molecular oxygen is then added to the radical position to form hydroperoxides. There are three potential oxidation routes based on the proposed autoxidation pathway that lead to the generation of the dioxane ring‐opening hydroxyl form, the 9,10‐epoxide form, or the 11,12‐epoxide form, depending on the substituted position of the added molecular oxygen. The epimer compound generated via the vinylic radical intermediate and sulfoxides was characterized. This degradation mechanism provides the scientific foundation for an oxidative stressing system currently under investigation.     

Differential involvement of neurons in the dorsal and ventral premotor cortex during processing of visual signals for action planning

We examined neuronal activity in the dorsal and ventral premotor cortex (PMd and PMv, respectively) to explore the role of each motor area in processing visual signals for action planning. We recorded neuronal activity while monkeys performed a behavioral task during which two visual instruction cues were given successively with an intervening delay. One cue instructed the location of the target to be reached, and the other indicated which arm was to be used. We found that the properties of neuronal activity in the PMd and PMv differed in many respects. After the first cue was given, PMv neuron response mostly reflected the spatial position of the visual cue. In contrast, PMd neuron response also reflected what the visual cue instructed, such as which arm to be used or which target to be reached. After the second cue was given, PMv neurons initially responded to the cue's visuospatial features and later reflected what the two visual cues instructed, progressively increasing information about the target location. In contrast, the activity of the majority of PMd neurons responded to the second cue with activity reflecting a combination of information supplied by the first and second cues. Such activity, already reflecting a forthcoming action, appeared with short latencies (<400 ms) and persisted throughout the delay period. In addition, both the PMv and PMd showed bilateral representation on visuospatial information and motor-target or effector information. These results further elucidate the functional specialization of the PMd and PMv during the processing of visual information for action planning.     

Japanese orthopaedic association cervical myelopathy evaluation questionnaire (JOACMEQ): Part 5. Determination of responsiveness

Background

In 1999, the Japanese Orthopaedic Association decided to develop a new Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). The final version of the JOACMEQ, comprising 24 questions and five domains (cervical spine function (CF); upper extremity function (UF); lower extremity function (LF); bladder function (BF); and quality of life (QOL)), was established after three nationwide investigations. The fourth investigation, reported in this paper, was performed to confirm the responsiveness of the questionnaire.

Association Between Anti-Helicobacter pylori Antibody Seropositive and De Novo Gallstone Formation After Laparoscopic Sleeve Gastrectomy for Japanese Patients with Severe Obesity

Purpose

Patients who have undergone bariatric surgery are at risk for gallstone formation. However, the incidence of gallstone formation after bariatric surgery has not been adequately studied in the Japanese population. We aimed to elucidate the incidence and risk factors for gallstone formation after laparoscopic sleeve gastrectomy (LSG) for Japanese patients with severe obesity.

Methods

We conducted a retrospective cohort study among patients with severe obesity treated with LSG between April 2017 and June 2020 at two institutions. Patients who had received previous cholecystectomy, had preoperative gallstones, and had received postoperative prophylactic ursodeoxycholic acid were excluded. Body weight, body mass index, and blood data were collected at each follow-up visit before and after the surgery. Follow-up abdominal ultrasonography was performed 6–12 months after surgery, and the incidence of gallstones was calculated. The association between the data and gallstone formation was evaluated.

Results

During the study period, we performed LSG for 98 patients. Of these, 61 cases remained by above conditions and were examined using abdominal ultrasonography over 6 months after surgery. The incidence of gallstones was 23.0% and that of symptomatic gallstones was 3.3%. Anti-Helicobacter pylori antibody seropositive and titer were the only factors that showed significant association with de novo gallstone formation after LSG.

Conclusions

Anti-Helicobacter pylori antibody seropositive may be associated with de novo gallstone formation after LSG for Japanese patients with severe obesity.

Graphical abstract

     

Evaluation of community-acquired pneumonia guidelines of Japanese Respiratory Society: differentiation of atypical pneumonia and bacterial pneumonia]

To evaluate the usefulness of differentiation of atypical pneumonia and bacterial pneumonia in the community-acquired pneumonia guidelines of the Japanese Respiratory Society, we investigated 124 cases of three atypical pneumonias (Mycoplasma pneumonia, 62 cases; Chlamydia pneumoniae pneumonia, 46 cases; Chlamydia psittaci pneumonia, 13 cases) and 403 cases of bacterial pneumonia at our hospital over seven years. Overall, the sensitivity and specificity of the criteria in the guideline were 70.4% and 91.8%, respectively. High accordance was recognized in patients under 60 years old with atypical pneumonia. Items in the criteria that included subjective factors were considered inassessable. We found that the differentiation of pneumonias in the guideline is useful for the diagnosis of atypical pneumonia among younger patients, but it should be concise and objective. We therefore propose that the criteria would be more effective if they consisted of only 4 items: age under 60 years, no underlying disorders, presence of stubborn dry cough, and normal peripheral white blood cell count.     

Increased bone resorption may play a crucial role in the occurrence of osteopenia in patients with type 2 diabetes: Possible involvement of accelerated polyol pathway in its pathogenesis

In order to investigate the underlying mechanism of alterations in bone mineral metabolism in patients with type 2 diabetes, we determined circulating levels of bone functional markers along with urinary excretion of sorbitol (SOR) and bone mineral density (BMD), and also examined their mutual interrelationship. A total of 151 male type 2 diabetic patients were examined in this study. Forty-eight age-matched male healthy subjects were also studied as the controls. A significant reduction of serum intact osteocalcin (i-OC) was found in the diabetic groups (p<0.01). On the other hand, circulating levels of tartrate resistant acid phosphatase (TRAP) in the diabetic patients were significantly higher than those in the controls (p<0.01). Interestingly, a significantly negative relationship was observed between BMD and serum TRAP (p<0.01), although no significant relationship was noted between BMD and serum i-OC in diabetic patients. Urinary excretion of SOR was significantly elevated in the diabetic patients when compared with the controls (p<0.01). In addition, a significantly positive correlation was observed between serum TRAP and urinary SOR (p<0.01), but not between serum i-OC and urinary SOR. Elevated serum TRAP in diabetes was reduced after the administration of aldose reductase inhibitor (p<0.05). It seems most likely that the increase in osteoclastic function probably due to accelerated polyol pathway plays a crucial role in the pathogenesis of decreased bone mineral content in male patients with type 2 diabetes.