Esophageal submucosal hematoma during transnasal endoscopy: A rare case report

Esophageal submucosal hematoma is a rare, often incidental complication of therapeutic endoscopic procedures marked by disrupted blood vessels beneath the esophageal mucosa, forming a hematoma. We report the unique case of a severely thin and alcoholic 38-year-old woman with a history of reflux esophagitis who developed an esophageal submucosal hematoma during an unsedated transnasal endoscopy for health check-up. During the procedure, the patient experienced strong vomiting reflexes and vomited blood, leading to the initial suspicion of either Mallory-Weiss syndrome or epistaxis. However, subsequent sedated endoscopy revealed an esophageal submucosal tumor-like lesion and a mucosal laceration with blood clots, prompting a dual diagnosis of esophageal submucosal hematoma and Mallory-Weiss syndrome. The bleeding was not severe enough to require hemostatic intervention. The patient opted for conservative treatment with vonoprazan, which resulted in the improvement and healing of the hematoma within 28 days. This is the first report of an esophageal submucosal hematoma during transnasal endoscopy and emphasizes the importance of including an esophageal submucosal hematoma and Mallory-Weiss syndrome in the differential diagnosis of hematemesis encountered in similar scenarios. Factors such as severe thinness, daily alcohol consumption, and reflux esophagitis may have possibly contributed to the development of the esophageal submucosal hematoma in this patient.

Source efficiency of alpha-emitters applied to the skin surface

Skin surface contamination by alpha-emitters is in itself not hazardous, but it would cause significant internal exposure in the case of injured skin as well as misjudgment in direct in vivo measurements (e.g. lung counting). The present study determined the source efficiency of alpha-emitters (241Am) applied to swine skin samples by analysing the observed alpha-particle energy spectra using advanced alpha-spectrometric simulation. Based on our results, the source efficiency was determined to be 0.365 (alpha-particle s-1 per Bq) on average (c.f. 0.5 in the case of no self-absorption in the source). The decrease in source efficiency would be attributed primarily to the radionuclide entering hair follicles or deep wrinkles. The degradation of the measured spectra from the skin samples indicates the penetration of some radionuclides into the upper layers of the stratum corneum. Although this study was limited to results obtained from swine skin samples, it suggests that irregularities in the skin surface may affect direct alpha measurements.

Differential Efficacy of Targeted Monoclonal Antibodies in Left-Sided Colon and Rectal Metastatic Cancers

BACKGROUND

The recommended first-line chemotherapy for RAS/BRAF wild-type metastatic colorectal cancer (mCRC) is bevacizumab (BEV)-containing therapy for right-sided colon cancer (R) and antiepidermal growth factor receptor antibody (anti-EGFR)-containing therapy for left-sided colon cancer (L) or rectal cancer (RE). However, anatomical or biological heterogeneity reportedly exists between L and RE. Therefore, we aimed to compare the efficacies of anti-EGFR and BEV therapies for L and RE, respectively.

METHODS

We retrospectively reviewed 265 patients with KRAS (RAS)/BRAF wild-type mCRC treated with fluoropyrimidine-based doublet chemotherapy plus anti-EGFR or BEV as the first-line treatment at a single institution. They were divided into 3 groups: R, L, and RE. Overall survival (OS), progression-free survival (PFS), objective response rate, and conversion surgery rate were analyzed.

RESULTS

Forty-five patients had R (anti-EGFR/BEV: 6/39), 137 patients had L (45/92), and 83 patients had RE (25/58). In patients with R, both median (m) PFS and OS were superior with BEV therapy (mPFS, anti-EGFR vs. BEV: 8.7 vs. 13.0 months, hazard ratio [HR]: 3.90, P = .01; mOS, 17.1 vs. 33.9 months, HR: 1.54, P = .38). In patients with L, better mPFS and comparable mOS with anti-EGFR therapy were observed (mPFS, 20.0 vs. 13.4 months, HR: 0.68, P = .08; mOS, 44.8 vs. 36.0 months, HR: 0.87, P = .53), whereas, in patients with RE, comparable mPFS and worse mOS with anti-EGFR therapy were observed (mPFS, 17.2 vs. 17.8 months, HR: 1.08, P = .81; mOS, 29.1 vs. 42.2 months, HR: 1.53, P = .17).

CONCLUSIONS

Efficacies of anti-EGFR and BEV therapies may differ between patients with L and RE.

Clinical outcomes of patients diagnosed with cancer of unknown primary or malignancy of undefined primary origin who were referred to a regional cancer center

BACKGROUND

A regional cancer hospital has been identified to be crucial in the management of malignancies of undefined primary origin (MUO) and cancer of unknown primary (CUP). This hospital primarily consists of oncologists with expertise in CUP, pathologists, and interventional radiologists. Early consultation or referral of MUO and CUP to a cancer hospital is deemed important.

METHODS

This study retrospectively collected and analyzed the clinical, pathological, and outcome data of all patients (n = 407) referred to the Aichi Cancer Center Hospital (ACCH) in Japan over an 8-year period.

RESULTS

In total, 30% of patients were referred for a second opinion. Among 285 patients, 13% had non-neoplastic disease or confirmed primary site and 76% had confirmed CUP (cCUP), with 29% of cCUP being identified as favorable risk. In 155 patients with unfavorable-risk CUP, 73% had primary sites predicted by immunohistochemistry (IHC) and distribution of metastatic sites, whereas 66% of them received site-specific therapies based on the predicted primary sites. The median overall survival (OS) was found to be poor in patients with MUO (1 month) and provisional CUP (6 months). In addition, the median OS of 206 patients with cCUP treated at the ACCH was 16 months (favorable risk, 27 months; unfavorable risk, 12 months). No significant difference was noted in OS between patients with non-predictable and predictable primary-sites (13 vs 12 months, p = 0.411).

CONCLUSION

The outcome of patients with unfavorable-risk CUP remains to be poor. Site-specific therapy based on IHC is not recommended for all patients with unfavorable-risk CUP.

Gastrointestinal IgG4 Deposition Is a New Histopathological Feature of Eosinophilic Gastroenteritis

BACKGROUND

The pathogenesis of eosinophilic esophagitis involves immunoglobulin G4 (IgG4) deposition. However, the relationship between IgG4 and eosinophilic gastroenteritis (EGE) is unclear.

AIMS

To investigate gastrointestinal deposition of IgG4 in EGE.

METHODS

Biopsies of the esophagus, stomach, and small intestine were evaluated in patients with and without EGE. Immunohistochemical staining for IgG4 was performed, and the proportions of the stained areas were compared. Sera from patients with EGE were assayed for food-specific IgG4, including egg white, wheat, rice, soy, and cow milk.

RESULTS

Seventeen patients were included in this study (EGE group, n = 10; control group, n = 7). Compared with the control group, the proportion of IgG4-stained area in the EGE group was approximately threefold higher (40.2% [32.3-49.5]) vs. 12.1% [4.0-21.9], p = 0.014) in the esophagus, fivefold higher in the stomach (17.3% [11.1-26.2] vs. 3.7% [1.5-5.2], p = 0.014), and sixfold higher in the small intestine (28.0% [15.0-33.2] vs. 4.5% [2.6-9.8], p = 0.019). There was no significant association between the proportion of IgG4-stained area and the number of infiltrating eosinophils. Serum egg white-specific IgG4 levels were correlated with the proportion of IgG4-stained areas in the small intestine (R = 0.7, p = 0.035).

CONCLUSIONS

IgG4 accumulated within the gastrointestinal mucosa in EGE. The positive correlation between serum egg white-specific IgG4 levels and the proportion of IgG4-stained areas in the small intestine suggests a role for IgG4 in the disease pathophysiology.

Short bevacizumab infusion as an effective and safe treatment for colorectal cancer

Bevacizumab is a humanized monoclonal antibody that contains <10% murine protein. To prevent infusion-related hypersensitivity reactions (HSRs), the initial bevacizumab infusion is delivered for 90 min, the second for 60 min and subsequent doses for 30 min. Several previous studies have shown that short bevacizumab infusions are safe and do not result in severe HSRs in patients with colorectal, lung, ovarian and brain cancer. However, the efficacy of short bevacizumab infusions for colorectal cancer management remains unclear. Therefore, to investigate this issue, a prospective multicenter study was conducted using 23 patients enrolled between June 2017 and March 2019. The initial infusion of bevacizumab was for 30 min followed by a second infusion rate of 0.5 mg/kg/min (5 mg/kg over 10 min and 7.5 mg/kg over 15 min. The primary endpoint was progression-free survival (PFS). The overall response and disease control rates were 57 and 87%, respectively. The median PFS time was 306 days (interquartile range, 204-743 days). No HSRs were noted. Adverse events associated with bevacizumab included grade 4 small intestinal perforation and grade 3 stroke in 1 patient each. These results suggest that a short bevacizumab infusion regime comprising an initial infusion for 30 min followed by a second infusion at 0.5 mg/kg/min is safe and efficacious for the management of colorectal cancer.

Clinical and microbiological features of obstructive cholangitis with bloodstream infection caused by Pandoraea apista identified by MALDI-TOF mass spectrometry and ribosomal RNA sequencing in a cancer patient

Background

Pandoraea species are multidrug-resistant glucose-nonfermenting gram-negative bacilli that are usually isolated from patients with cystic fibrosis (CF) and from water and soil. Reports of diseases, including bloodstream infections, caused by Pandoraea spp. in non-CF patients are rare, and the clinical and microbiological characteristics are unclear. The identification of Pandorea spp. is limited by conventional microbiological methods and may be misidentified as other species owing to overlapping biochemical profiles. Here, we report the first case of obstructive cholangitis with bacteremia caused by Pandoraea apista in a patient with advanced colorectal cancer.

A 61-year-old man with advanced colorectal cancer who underwent right nephrectomy for renal cell carcinoma 4 years earlier with well-controlled diabetes mellitus was admitted to our hospital with fever for 2 days. The last chemotherapy (regorafenib) was administered approximately 3 weeks ago, and an endoscopic ultrasound-guided hepaticogastrostomy was performed 2 weeks ago under hospitalization for obstructive jaundice. Two days prior, he presented with fever with chills. He was treated with piperacillin-tazobactam for obstructive cholangitis and showed improvement but subsequently presented with exacerbation. Bacterial isolates from the blood and bile samples were identified as P. apista using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S ribosomal RNA sequencing. Based on the susceptibility results of the isolates, he was successfully treated with oral trimethoprim-sulfamethoxazole 160 mg/800 mg/day for 14 days for P. apista infection.

Conclusions

Pandoraea species are often misidentified. Therefore, multiple approaches should be used to identify them, and decisions regarding antimicrobial treatment should be based on actual in vitro susceptibility. Only seven cases of Pandoraea spp. bloodstream infections have been reported, and we report the first case of cholangitis with bacteremia.

Efficacy of immune checkpoint inhibitors for gastrointestinal cancers with SWI/SNF complex genetic alterations

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Background: SWI/SNF chromatin-remodeling complex is encoded by multi-gene families that are recurrently mutated in cancer. Previous studies reported that tumors harboring SWI/SNF complex genetic alterations (GA) are sensitive to immune checkpoint inhibitors (ICIs), but the clinical significance of SWI/SNF complex GA in patients with gastrointestinal cancers (GICs) is unclear. Methods: We reviewed patients with metastatic GICs who underwent comprehensive genomic profiling (CGP) and received ICIs at our institution between July 2014–June 2021. SWI/SNF complex GA were defined as ARID1A, ARID1B, ARID2, PBRM1, SMARCA4, and SMARCB1 alterations. Results: Of 292 patients receiving CGP, 136 patients received ICIs, of which 10 (7.4%) had SWI/SNF GA, including 8 ARID1A (5.9%), 1 ARID2 (0.7%) and 2 SMARCA4 (1.5%) alterations. The subjects included 50 esophageal cancers, 84 gastric cancers, and 2 small intestine cancers. The patients with SWI/SNF complex GA had significantly higher proportions of microsatellite instability-high ( p = 0.004) and lower proportions of esophageal cancer ( p = 0.002), compared with patients without SWI/SNF complex GA. During the median follow-up time of 7.5 months (M), the median overall survival (OS), time-to-treatment failure (TTF), and progression-free survival (PFS) in all patients was 13.2 M ([95% confidence interval [CI] 7.7-21.8 M), 2.2 M (95%CI, 1.8-2.5 M), and 2.3 M (95%CI, 1.9-2.8 M), respectively. The patients with SWI/SNF complex GA had better OS (median, not reached vs 10.3 M; hazard ratio [HR], 0.40 [95% confidence interval [CI] 0.19–0.86]; p = 0.019) than those without SWI/SNF complex GA. The patients with SWI/SNF complex GA tended to have longer TTF (median, 4.7 M vs 2.1 M; HR, 0.67 [95%CI 0.38–1.17]; p = 0.16) and PFS (median, 5.4 M vs 2.2 M; HR, 0.70 [95%CI 0.39–1.27], p = 0.24) than those without SWI/SNF GA. The objective response rate (ORR) and disease control rate (DCR) in all patients was 13.2% (95%CI, 8.0-20.1) and 40.4% (95%CI, 32.1-49.2), respectively. The ORR and DCR of patients with SWI/SNF complex GA tended to be higher than those without SWI/SNF complex GA (ORR, 30.0% vs 11.9%; p = 0.13: DCR, 70.0% vs 38.1%; p = 0.09), with 1 complete response and 2 partial responses in the patients with SWI/SNF complex GA. Conclusions: The patients with GICs who had SWI/SNF complex GA were more likely to benefit from ICI therapy, suggesting that novel ICI-containing chemotherapies targeting SWI/SNF complex GA are needed for GICs.[Table: see text]

Impact of the COVID-19 Pandemic on Patients with Gastrointestinal Cancer Undergoing Active Cancer Treatment in an Ambulatory Therapy Center: The Patients' Perspective

Background: The mortality risk increases greatly in patients with cancer if they are infected with severe acute respiratory syndrome coronavirus 2. The new American Society of Clinical Oncology (ASCO) and the European Society of Medical Oncology (ESMO) guidelines for the COVID-19 pandemic suggested modifications to the standards of care to reduce harm from treatment. However, it is unclear whether these changes suit the wishes of patients. Methods: We conducted a survey of patients with gastrointestinal cancer who were undergoing active chemotherapy in our ambulatory therapy center between 17 August and 11 September 2020. The survey comprised 18 questions on five topics: patient characteristics, lifestyle changes, disturbance in their psychological health, thoughts on the cancer treatment, and infection control in the hospital. Results: Among the 63 patients who received the questionnaire, 61 participated in the study. The COVID-19 pandemic has led to changes in their lifestyles and substantially impacted their psychological wellbeing. The incidence of anxiety and insomnia has considerably increased during the pandemic. However, female patients and patients aged 70 years or older reported no notable differences. There was no significant difference in the responses to the questions regarding thoughts on the cancer treatment. Conclusion: Our study revealed that the COVID-19 pandemic has substantially impacted patients’ lifestyles and psychological wellbeing. However, most patients preferred to continue their usual treatment without any change to their treatment plan. It is important to involve the patient in the decision-making process when formulating treatment goals.

NOD-Like Receptor Family Pyrin Domain-Containing 3 Inflammasome Activation Exacerbates 5-Fluorouracil-Induced Small Intestinal Mucositis via Interleukin-1β Activation

BACKGROUND AND AIM

5-Fluorouracil (5-FU) is an anticancer agent that induces intestinal mucositis, which causes diarrhea and dehydration. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is responsible for inflammatory response activation via caspase-1 cleavage and subsequent interleukin-1β (IL-1β) and IL-18 activation and secretion. The objective of this study was to determine the role of the NLRP3 inflammasome in 5-FU-induced small intestinal mucositis.

METHODS

Small intestinal mucositis was induced in wild-type, NLRP3-/-, and caspase-1-/- mice by intraperitoneal injection of 5-FU. Some mice received intraperitoneal injection of a caspase-1 inhibitor, recombinant IL-1β or IL-18, or neutralizing antibody against IL-1β.

RESULTS

Mice treated with 5-FU developed small intestinal mucositis with diarrhea and body weight loss, characterized by a decrease in villus height and the villus height-to-crypt depth ratio. These histological changes peaked on day 3 and were accompanied by an increase in mRNA expression of NLRP3 and IL-1β and protein expression of cleaved caspase-1 and mature IL-1β. Mature IL-18 protein expression was not affected by 5-FU administration. NLRP3-/- mice exhibited less severe 5-FU-induced mucositis, and this phenotype was mimicked by genetic depletion or pharmacological inhibition of caspase-1. Small intestinal mucositis was aggravated by exogenous IL-1β and neutralized by IL-1β antibody treatment. Administration of exogenous IL-18 or anti-IL-18 antibody did not affect any parameters associated with mucositis. NLRP3, cleaved caspase-1, and IL-1β were expressed by inflammatory cells (mainly macrophages) in the lamina propria and damaged epithelial cells.

CONCLUSIONS

NLRP3 inflammasome activation may exacerbate 5-FU-induced small intestinal mucositis via IL-1β maturation.

A case of nivolumab-induced cervical lymphadenopathy in a patient with gastric cancer

Nivolumab is a monoclonal antibody targeting programmed cell death-1 (PD-1) that has been recently shown to exhibit clinical efficacy in patients with gastric cancer. However, various degrees of immune-related adverse events (irAEs) have been reported. We report the case of a 71-year-old male patient diagnosed with gastric cancer with peritoneal metastases. He was treated with nivolumab as third-line chemotherapy. On the 10^th day after completing seven cycles of nivolumab treatment, he urgently visited the hospital because of mild left cervical lymphadenopathy. We suspected it to be due to inflammation and initiated treatment with levofloxacin hydrate. However, 3 days later, he was admitted to the emergency room due to exacerbation of his lymphadenopathy. A diagnosis of nivolumab-induced lymphadenopathy was made as the antibiotics were ineffective, and the patient was administered prednisolone (PSL) 20 mg. One day after admission, the pain and swelling of the lymph node greatly lessened, and the following day, the pain gradually disappeared; thereafter, the PSL dose was tapered and nivolumab treatment was resumed. The patient again developed cervical lymphadenopathy approximately 4-5 days after nivolumab was reintroduced, which disappeared 1 week later. During each episode of lymphadenopathy, he received a dose of 20 mg of PSL for 4 days, which would be eventually tapered to 10 mg without antibiotics and NSAIDs. After 2 months, cervical lymphadenopathy completely disappeared while 10 mg of PSL was continued, which was also eventually tapered off. To our knowledge, this is the first case report of nivolumab-induced lymphadenopathy in a patient with gastric cancer. This case suggested that we should keep in mind that various irAEs may occur during treatment with immune checkpoint inhibitors. It is necessary to ensure the absence of infection and metastasis before treatment and to promptly administer systemic corticosteroids to address them.

Role of nucleotide binding oligomerization domain-like receptor protein 3 inflammasome in stress-induced gastric injury

BACKGROUND AND AIM

The inflammasomes promote pro-caspase-1 cleavage, leading to processing of pro-interleukin (IL)-1β into its mature form. We investigated the role of the IL-1β and nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in gastric injury in mice receiving water-immersion restraint stress (WIRS), focusing on the cyclooxygenase (COX)-2/prostaglandin (PG) E₂ axis.

METHODS

To induce gastric injury, the mice were placed in a restraint cage and immersed in the water bath to the level of the xiphoid process. Protein levels of mature caspase-1 and IL-1β were assessed by western blotting.

RESULTS

Water-immersion restraint stress induced gastric injury with increase in IL-1β expression by activation of NLRP3 inflammasome. Exogenous IL-1β attenuated the injury, whereas anti-IL-1β neutralizing antibody and IL-1β receptor antibody aggravated it. NLRP3^-/- and caspase-1^-/- mice enhanced the injury with reducing of mature IL-1β, and this aggravation was reduced by exogenous IL-1β supplementation. Toll-like receptor 4^-/- mice were hyporesponsive to WIRS in terms of mature IL-1β production. Rabeprazole attenuated the injury with preventing inflammasome activation. WIRS injured the stomach with promotion of COX-2 mRNA and PGE₂ production, and exogenous IL-1β enhanced these molecules, while IL-1β immunoneutralization exerted opposite effect. PGE₂ supplementation abolished the hypersensitivity in NLRP3^-/- and caspase-1^-/- mice through negative regulation of inflammatory cytokines.

CONCLUSION

These results suggest that NLRP3 inflammasome-derived IL-1β plays a protective role in stress-induced gastric injury via activation of the COX-2/PGE₂ axis. Toll-like receptor 4 signaling and gastric acid may be involved in NLRP3 inflammasome activation.

Utility of Kyoto Classification of Gastritis in subjects with a high-negative titer of anti-Helicobacter pylori antibody during a medical check-up

Subjects with a high-negative titer (3-9.9 U/ml) of serum anti-Helicobacter pylori (H. pylori) antibody represent a heterogeneous group of currently H. pylori-infected, H. pylori-uninfected, and previously H. pylori-infected cases. We investigated the characteristics of subjects with a high-negative titer during a medical check-up and the utility of H. pylori infection score, the sum of scores of endoscopic findings based on the Kyoto Classification of Gastritis, for diagnosing H. pylori infection. Subjects with ¹³C-urea breath test-positive or H. pylori stool antigen test-positive were diagnosed as currently H. pylori-infected. Although around half of subjects with a high-negative titer were after eradication therapy (48.6%), currently H. pylori-infected were considerably confirmed (11.7%). H. pylori infection score showed a high value of area under the receiver operating characteristic curve [0.92; 95% confidence interval (CI), 0.84-1.00] with the most suitable cut-off value of 1.0 (sensitivity: 0.92; specificity: 0.90). Multivariate logistic regression analysis revealed that H. pylori infection score was an independent factor associated with increased prevalence of H. pylori infection (odds ratio, 9.53; 95% CI, 2.64-34.40; p<0.001). Currently H. pylori-infected subjects were considerably included among the subjects with a high-negative titer, and the Kyoto Classification of Gastritis was useful to predict current H. pylori infection.

A Rare Case of Clival Metastasis in a Patient with Gastric Cancer

We report a rare case of clival metastasis from gastric cancer. A 73-year-old man with advanced gastric cancer treated with nivolumab as a third-line chemotherapy experienced headache, tongue deviation, and difficulties in speaking clearly. We suspected stroke or brain metastasis, but brain contrast-enhanced magnetic resonance imaging demonstrated a clival mass, diagnosed as clival metastasis from gastric cancer. The tumor could not be identified by plain computed tomography and plain magnetic resonance imaging alone. He received palliative radiotherapy (30 Gy/10 fr); his symptoms improved gradually. Although metastasis from gastric cancer to other organs is common, bone metastases are rare.

Gastric acid inhibitor aggravates indomethacin-induced small intestinal injury via reducing Lactobacillus johnsonii

Proton pump inhibitors (PPIs) alter the composition of the intestinal microbiome, exacerbating indomethacin (IND)-induced small intestinal damage. Vonoprazan fumarate inhibits gastric acid secretion using a different mechanism from PPIs. We investigated the effects of both drugs on the intestinal microbiome and IND-induced small intestinal damage. We sought to clarify whether PPI-induced dysbiosis and worsening of the damage were due to a specific drug class effect of PPIs. Rabeprazole administration increased operational taxonomic unit numbers in the small intestines of C57BL/6 J mice, whereas the difference was not significant in the vonoprazan-treated group but exhibited a trend. Permutational multivariate analysis of variance of the unweighted UniFrac distances showed significant differences between vehicle- and vonoprazan- or rabeprazole-treated groups. L. johnsonii was the predominant microbial species, and the population ratio decreased after vonoprazan and rabeprazole administration. The vonoprazan- and rabeprazole-treated groups showed increased IND-induced damage. This high sensitivity to IND-induced damage was evaluated by transplantation with contents from the small intestine of mice treated with either vonoprazan or rabeprazole. Supplementation of L. johnsonii orally in mice treated with rabeprazole and vonoprazan prevented the increase in IND-induced small intestinal damage. In conclusion, both rabeprazole and vonoprazan aggravated NSAID-induced small intestinal injury by reducing the population of L. johnsonii in the small intestine via suppressing gastric acid secretion.

[A case of pancreatic neuroendocrine tumor with ring-like enhancement]

An 82-year-old female underwent contrast computed tomography (CT) that revealed multiple ring-like enhanced masses in the pancreatic tail. Additionally, the inside of the masses showed enhancement on contrast endoscopic ultrasound (EUS). She was diagnosed with a pancreatic neuroendocrine tumor on histopathological examination after EUS-guided fine-needle aspiration, and distal pancreatectomy and splenectomy were performed. In the resected specimen, toward the tumor center, tumor cells with lipid droplets and fibrosis were remarkably observed. These rare histopathological features well reflected the image findings of contrast CT and contrast EUS.

Involvement of gliadin, a component of wheat gluten, in increased intestinal permeability leading to non-steroidal anti-inflammatory drug-induced small-intestinal damage

Gliadin, a component of wheat gluten known to be an important factor in the etiology of celiac disease, is related to several other diseases through its enhancing effect on intestinal paracellular permeability. We investigated the significance of gliadin in non-steroidal anti-inflammatory drug (NSAID)-induced small-intestinal damage in mice. 7-week-old C57BL/6 male mice were divided into the following groups: standard diet group, in which mice were fed with wheat-containing standard rodent diet (CE-2); gluten-free diet group, in which mice were fed with gluten-free diet (AIN-76A); and gliadin-administered group, in which mice fed with gluten-free diet were administered with gliadin (~250 mg/kg BW). Each group was subdivided into negative, healthy control group and NSAID-treated group. To some mice fed with gluten-free diet and administered with gliadin, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor was administered for clarification of the significance of EGFR in NSAID-induced small intestinal damage and intestinal permeability. In mice fed with a gluten-free diet, indomethacin or diclofenac induced very mild mucosal damage in the small intestine compared with that in mice fed with a wheat-containing standard diet. Gliadin exacerbated the NSAID-induced small-intestinal damage in mice fed with a gluten-free diet. With the administration of indomethacin, MPO activity, a marker of neutrophil infiltration into the mucosa and mRNA expression level of tumor necrosis factor α and interleukin-1β in the small intestine were higher in the gliadin-administered mice. Gliadin increased the intestinal paracellular permeability without indomethacin administration (4.3-fold) and further increased the permeability after indomethacin administration (2.1-fold). Gliadin induced phosphorylation of epidermal growth factor receptor (EGFR) in small-intestinal tissues, and erlotinib (an EGFR tyrosine kinase inhibitor) attenuated the indomethacin-induced intestinal damage and permeability exacerbated by gliadin, accompanied by inhibition of EGFR phosphorylation. These results suggest that gliadin plays an important role in the induction and exacerbation of NSAID-induced small-intestinal damage, and that increase in intestinal permeability via the EGFR signalling pathway is involved in its mechanism.

EFFECT OF SEASONAL CHANGES ON TESTICULAR MORPHOLOGY AND THE EXPRESSION OF CIRCADIAN CLOCK GENES IN JAPANESE WOOD MICE (APODEMUS SPECIOSUS)

This study aimed to determine the seasonality of reproduction throughout the year in Japanese wood mice (Apodemus speciosus). The effect of seasonal changes on testicular morphology and the periodic expression of circadian clock genes in the hypothalamus and testes of male individuals was evaluated. We also examined the morphology of the testes and caudae epididymides of male mice. In addition, RT-PCR analysis was carried out with mRNA extracted from the hypothalamus and testes to evaluate the expression of the circadian clock genes Clock, Bmal1, Per1, and Cry1. The complete induction of testicular activity was detected from February to April and from August to October, with testes weight increasing with the completion of spermatogenesis (reproductive season). From May to early June and from November to early January, testicular weight declined, the seminiferous tubules reduced in size, spermatogenesis was arrested, and sperm were not produced (non-reproductive season). From mid- June to July and mid-January, the re-induction of testicular activity for spermatogenesis was observed in the seminiferous tubules (transitional season). Out of the four examined genes, Cry1 had the highest expression level in both the hypothalamus and testes throughout the year, followed by Bmal1, Per1, and Clock. The expression of Bmal1 was significantly lower in the hypothalamus and testes during the transitional season compared to the reproductive and non-reproductive seasons. Cry1 transcript levels were also significantly lower in the hypothalamus and testes during the transitional season compared to the reproductive season. In conclusion, the results indicating changes in testicular morphology revealed annual reproductive, non-reproductive, and transmission periods in Japanese wood mice. When an increase in testicular activity was observed indicating the onset of the reproductive season, the mean day length was approximately 11–13 h. The expression of the circadian clock genes Bmal1 and Cry1 in the hypothalamus and testes during the reproductive season was significantly higher than that of the same genes during the transitional season. Consequently, completion of spermatogenesis occurred in the seminiferous tubules of Japanese wood mice testes during the reproductive period.

Radioactive pollution from Fukushima Daiichi nuclear power plant in the terrestrial environment

Major contaminants from venting and hydrogen explosions at the Fukushima Daiichi nuclear reactors between 12 and 15 March 2011 were transported northwestward and deposited on soil and plants via precipitation. Surface soils and plant leaves were sampled at 64 sites in the Fukushima Prefecture. The highest concentrations of (134)Cs (84.4 kBq kg(-1)) and (137)Cs (82.0 kBq kg(-1)) in surface soils were observed at Nagadoro in Iidate village located 32 km northwest from the Fukushima Daiichi nuclear power plant. Furthermore, (131)I, (129)Te, (129 m)Te, (110 m)Ag and (140)La were detected in the same samples. Outer surface of plant leaves, such as bamboo, cabbage and grasses were highly contaminated at the high-dose rate areas of Tsushima and Minami-Tsushima in Namie town. Mugwort leaves that grew after the pollution event had extremely low concentration of radionuclides; however, the plant/soil radiocaesium ratio was 0.023 ± 0.006. It is anticipated that decomposition of fallen leaves will promote recycling of radionuclides in the environment.

Active cigarette smoking, secondhand smoke exposure at work and home, and self-rated health

OBJECTIVES

Although active smoking has been reported to be associated with poor self-rated health (SRH), its association with secondhand smoke (SHS) is not well understood.

STUDY DESIGN

A cross-sectional study was conducted to examine the association of active smoking and SHS exposure with SRH.

METHODS

A total of 2558 workers (1899 men and 689 women), aged 16-83 (mean 45) years, in 296 small and medium-sized enterprises were surveyed by means of a self-administered questionnaire. Smoking status and exposure levels to SHS (no, occasional or regular) among lifetime non-smokers were assessed separately at work and at home. SRH was assessed with the question: How would you describe your health during the past 1-year period (very poor, poor, good, very good)? SRH was dichotomized into suboptimal (poor, very poor) and optimal (good, very good). Odds ratios (ORs) with 95% confidence intervals (CIs) for reporting suboptimal vs optimal SRH according to smoking status and smoke exposure were calculated.

RESULTS

Current heavy smokers (20+ cigarettes/day) had a significantly increased suboptimal SRH than lifetime non-smokers after adjusting for sociodemographic, lifestyle, physical and occupational factors (OR 1.34, 95% CI 1.06-1.69). Similarly, lifetime non-smokers occasionally exposed to SHS at work alone had worse SRH than their unexposed counterparts (OR 1.50, 95% CI 1.02-2.11). In contrast, lifetime non-smokers exposed at home alone had no significant increase in suboptimal SRH.

CONCLUSIONS

The present study indicates an increase in suboptimal SRH among current heavy smokers, and suggests that SHS exposure at work is a possible risk factor for non-smokers. Whether or not the association is causal, control of smoking at work may protect workers from developing future health conditions.

Naïve (CD4+CD45RA+) T cell subpopulation is susceptible to various types of hazardous substances in the workplace

To find the most susceptible lymphocyte subpopulation with exposure to various occupational hazardous substances, we reanalyzed our previous data. We measured T, B and natural killer NK cell subpopulations by means of flowcytometry among workers who were exposed to aromatic amines, chromate, mercury lead and organic-solvents. The exposed/non-exposed ratio was defined as the mean value of the absolute number of lymphocyte subpopulations in the exposed workers divided by the corresponding value of the non-exposed control group in 5 studies reported previously by us. The ratio of CD4+CD45RA+ T cells in all the exposed groups examined in this study was less than 1.0, and the mean of these ratio was 0.77, which was the lowest among lymphocyte subpopulations examined. The mean ratio was 1.06 for CD4+CD29+ T cells, 0.91 for CD4+ T cells, 0.99 for CD8+ T cells, 0.93 for CD3+ T cells, 0.99 for CD19+B cells, 0.96 for CD57-CD16+ NK cells, 0.82 for CD57+CD16+ NK cells, 1.25 for CD57+CD16- NK cells and 0.89 for total lymphocytes. With regard to the difference between exposed and non-exposed workers the estimated overall difference in the mean absolute number of CD4+CD45RA+ T cell subpopulation between exposed and non-exposed workers among five studies was -135 ((% confidence interval, CI: (-194,-75)) cells/mm3 (p<0.01). In conclusion, naïve (CD4+CD45RA+) T cell subpopulation was the most susceptible to the effects of various toxic substances as compared with other lymphocyte subpopulations. This lympohocyte subpopulation may be useful for monitoring immune system of workers exposed to various types of substances in the workplace.

Evaluation of the position, mobility, and morphology of the disc by MRI before and after four different treatments for temporomandibular joint disorders

OBJECTIVES

The purpose of this study was to evaluate changes in disc position, mobility, and morphology in patients with temporomandibular joint disorders (TMD) in response to four different treatments, splint therapy, pumping manipulation, arthrocentesis, and arthroscopic surgery, using magnetic resonance imaging (MRI).

METHODS

Eighty-five joints (85 patients) with unilateral internal derangement or osteoarthritis that were successfully treated were included in this study. The patients were divided into four groups as follows: splint therapy group, pumping manipulation group, arthrocentesis group, and arthroscopic surgery group. Changes in the disc position, mobility, and morphology before and after treatment were compared among the four groups using MRI.

RESULTS

All discs showed anterior disc displacement (ADD) without reduction before treatment. Only 10% of the joints became ADD with reduction after treatment, and the other joints remained ADD without reduction in spite of treatment. Discs treated by arthroscopic surgery were located more anteriorly compared with pre-treatment. In pre-treatment MRI, the rate of stuck disc increased as the stage of the treatment advanced. In post-treatment MRI, all temporomandibular joints (TMJs) had mobile discs. The disc deformity advanced after arthrocentesis and arthroscopic surgery.

CONCLUSIONS

Even though clinical signs and symptoms were alleviated by treatment, most discs remained ADD without reduction on MRI in spite of treatment. This suggests that the four treatments do not necessarily improve the position and deformity of the disc, and that arthroscopic surgery advances the deformity and anterior displacement of the disc. Disc mobility is important for improving clinical signs and symptoms.

Isolation and characterization of synovial cells from the human temporomandibular joint

BACKGROUND

The synovial tissues with temporomandibular disorders (TMDs) often show chronic inflammatory changes and the synovial cells participate in the pathogenic processes of TMDs. The synovial membrane is composed of a synovial lining layer and a connective sublining layer. The synovial lining layer is made up of two kinds of cells: macrophage-like type A and fibroblastic type B cells. The aim of this study was to isolate and characterize synovial cells from the human temporomandibular joint (TMJ).

METHODS

Synovial cells were isolated using an explant culture method. Then, we characterized the cultured synovial cells (SGA2 cells) using immunocytochemistry.

RESULTS

SGA2 cells expressed the fibroblastic markers vimentin and prolyl 4-hydroxylase; they also expressed laminin and heat shock protein 27, all of which are markers of type B cells. However, some cells expressed the macrophage marker CD68. These CD68-positive cells simultaneously expressed laminin.

CONCLUSIONS

We isolated and cultured synovial type B cells from the human TMJ, and identified the presence of intermediate type synovial lining cells, having the phenotypic properties of both type A and type B cells, among the synovial lining cells.

The characteristics of karyotype and telomeric satellite DNA sequences in the cricket, Gryllus bimaculatus (Orthoptera, Gryllidae)

The chromosomes derived from the Japanese population of Gryllus bimaculatus were characterized by C-banding and Ag-NOR staining. The chromosome number, 2n = 28 + XX (female)/XO (male), corresponded with that of other populations of G. bimaculatus, but the chromosome configuration in idiograms varied between the populations. NORs were carried on one pair of autosomes and appeared polymorphous. The positive C-bands located at the centromere of all chromosomes and the distal regions of many chromosome pairs, and the size and the distribution pattern of the distal C-heterochromatin showed differences among the chromosomes. In addition, this paper reports on the characteristics of HindIII satellite DNA isolated from the genome of G. bimaculatus. The HindIII repetitive fragments were about 0.54 kb long, and localized at the distal C-bands of the autosomes and the interstitial C-bands of the X chromosome. Molecular analysis showed two distinct satellite DNA sequences, named the GBH535 and GBH542 families, with high AT contents of about 67 and 66%, respectively. The two repetitive families seem to be derived from a common ancestral sequence, and both families possessed the same 13-bp palindrome sequence. The results of Southern blot hybridization suggest that the sequence of the GBH535 family is conserved in the genomic DNAs of Gryllus species, whereas the GBH542 family is a species-specific sequence.