Changes in zinc and manganese concentrations in cisplatin-induced acute kidney injury.

Cisplatin (CDDP) is a widely used anticancer drug, but acute kidney injury (AKI) is one of the most important dose-limiting factors. Trace metal elements are present in various concentrations in the body and play an important role in maintaining normal vital functions. However, the relationship between CDDP-induced AKI and trace metal elements is unknown. In this study, we cultured human renal proximal tubular epithelial cells in the presence of CDDP (0, 12.5, 25, 50 µM) and analyzed the concentration of trace elements in medium after 24 h. We found that CDDP significantly increased the concentrations of zinc (Zn) and manganese (Mn) in medium and significantly decreased them in lysate. Therefore, we examined the effects of CDDP (3 mg/kg, i.p.) administration on serum and urinary Zn and Mn concentrations in rats. The results showed that urinary excretion of Zn and Mn increased in CDDP-treated rats 5 days after administration. Also, 5 days after administration, pyknosis, nuclear loss, loss of the brush border membrane, and DNA fragmentation were observed, and serum creatinine and blood urea nitrogen levels were found to be significantly increased. These data suggested that 24-h excretion of Zn and Mn might reflect on CDDP induced nephropathy. Monitoring urinary Zn and Mn excretion may be beneficial in detecting AKI, but further studies are needed for clinical application.

Effect of Replicative Senescence on the Expression and Function of Transporters in Human Proximal Renal Tubular Epithelial Cells.

In the field of cosmetic research, there is a growing interest in alternatives to animal experiments, such as in vitro models using cultured cells. The trend is spreading to the field of food and drugs. Although various types of cells are used as in vitro models, the effect of cellular senescence on the expression and function of transporters in these models is unclear. In the present study, we examined the effect of replicative senescence (by passage culture) on the expression and function of transporters in renal proximal tubular epithelial cells (RPTECs). The increase in senescence-associated-ß-galactosidase (SA-ß-gal)-positive cells, cell cycle arrest markers, and senescence-associated secretory phenotype (SASP) markers was associated with an increase in passage numbers of RPTECs. Gene expression of various transporters in RPTEC was also altered. The mRNA level of organic cation transporter 2 decreased most rapidly with passage numbers among the transporters. The uptake of fluorescent cationic substrates in SA-ß-gal-positive RPTECs was less than that in SA-ß-gal-negative RPTECs. However, these changes in the expression of transporters seem to be significantly different from those observed in rodents and human kidneys in many aspects. As cellular senescence is observed in various situations, especially in RPTECs, it may be necessary to exclude it from toxicological and pharmacokinetic evaluations using in vitro models as much as possible. Additionally, when discussing cellular senescence, it is important to note the differences between aging in cells and aging and senescence in individuals.

Protective effects of tadalafil on damaged podocytes in an adriamycin-induced nephrotic syndrome model.

Podocyte injury is responsible for nephrotic syndrome. Previously, we found that tadalafil, a phosphodiesterase 5 inhibitor, might have protective effects on podocytes. Here, we investigated the effects of tadalafil in a nephrotic syndrome model and human podocyte cells. We divided adriamycin (ADR)-induced nephrotic syndrome model rats into the following groups: control + vehicle, control + tadalafil, ADR + vehicle, and ADR + tadalafil. The tadalafil-treated groups were orally administered 10 mg/kg tadalafil for 2 weeks. Renal parameters were measured. Immunohistology and immunofluorescence assays of glomerular injury were performed. Human primary podocytes were treated with or without tadalafil, and ADR. Cell viability and permeability assays were performed. ADR + vehicle exhibited severe proteinuria compared with control + vehicle and control + tadalafil. ADR + tadalafil attenuated proteinuria compared with ADR + vehicle. Wilms' tumor 1 (WT1) immunostaining revealed that the number of WT1-positive cells was decreased by ADR; however, this decrease was prevented by ADR + tadalafil. In human podocytes, tadalafil increased the viability of ADR-treated cells, which was abrogated by KT5823, a cGMP-dependent protein kinase (PKG) inhibitor. Moreover, tadalafil prevented albumin permeability in ADR-treated cells. ADR treatment alone increased the permeability of albumin compared with the control. Tadalafil might inhibit kidney injury progression by preventing damage to podocytes and dysfunction of the glomerular filtration barrier.

Degree of Differentiation of Esophageal Squamous Cell Carcinoma and Micrometastasis to Lymph Nodes.

Objectives: The goal of the study was to examine the relationships among micrometastasis, pathological degree of differentiation and survival in patients with esophageal squamous cell carcinoma (SCC). Design: A single-center retrospective study of patients diagnosed with thoracic esophageal SCC. Methods: Immunostaining using CK13 was carried out for all lymph nodes resected by radical esophagectomy with three-field lymphadenectomy. The relationships among micrometastasis to lymph nodes, degree of differentiation and survival were investigated. Results: The 25 patients included 14 (56.0%) well-differentiated and 11 (44.0%) moderately differentiated cases. In multivariate analysis, well-differentiated cases were not related to micrometastasis (odds ratio (OR): 1.5, confidence interval (CI): 0.2-12, p=0.7). In multivariate analysis of survival, cases in pStage III or higher were likely to have shorter survival (hazard ratio (HR): 2.8, CI: 0.7-12, p=0.16), and those with micrometastasis also tended to have shorter survival (HR: 2.7, CI: 0.8-9, p=0.11)); however, well-differentiated cases were not significantly related to survival (HR: 1.5, CI: 0.4-5.5, p=0.5). Conclusion: Micrometastasis to lymph nodes may be a prognostic factor even in advanced esophageal cancer. The degree of differentiation was not related to micrometastasis or survival.

A case of simultaneous abdominal wall metastasis of hepatocellular carcinoma with long-term relapse-free survival after laparoscopic resection.

We report our experience of an extremely rare case of a simultaneous extrahepatic metastasis of hepatocellular carcinoma (HCC) with long-term relapse-free survival, treated by laparoscopic resection of an abdominal wall tumor and subsequent radiofrequency ablation (RFA) of an intrahepatic lesion. A 76-year-old man visited a local clinic for right lower abdominal pain. He was treated with antibiotics and the symptom resolved. However, a mass was detected in the same region and he was referred to our hospital for further evaluation. Computed tomography (CT) of the abdomen showed a mass 5 cm in diameter, raising suspicions of an intra-abdominal tumor. Laparoscopic surgery was performed, and the tumor was found in the abdominal wall and completely resected. Histopathological examination yielded a diagnosis of extrahepatic HCC. Post-operative positron emission tomography (PET)-CT showed increased uptake of fluorodeoxyglucose in segment 3 (S3) of the liver. On performing a liver biopsy, HCC was diagnosed. Subsequently, the S3 lesion was treated with radiofrequency ablation. The patient has remained relapse-free for 6 years without further treatments.

Gastric epithelial neoplasm of fundic-gland mucosa lineage: proposal for a new classification in association with gastric adenocarcinoma of fundic-gland type.

BACKGROUND: Gastric adenocarcinoma of fundic-gland type (GA-FG) is a rare variant of gastric neoplasia. However, the etiology, classification, and clinicopathological features of gastric epithelial neoplasm of fundic-gland mucosa lineage (GEN-FGML; generic term of GA-FG related neoplasm) are not fully elucidated. We performed a large, multicenter, retrospective study to establish a new classification and clarify the clinicopathological features of GEN-FGML. METHODS: One hundred GEN-FGML lesions in 94 patients were collected from 35 institutions between 2008 and 2019. We designed a new histopathological classification of GEN-FGML using immunohistochemical analysis and analyzed via clinicopathological, immunohistochemical, and genetic evaluation. RESULTS: GEN-FGML was classified into 3 major types; oxyntic gland adenoma (OGA), GA-FG, and gastric adenocarcinoma of fundic-gland mucosa type (GA-FGM). In addition, GA-FGM was classified into 3 subtypes; Type 1 (organized with exposure type), Type 2 (disorganized with exposure type), and Type 3 (disorganized with non-exposure type). OGA and GA-FG demonstrated low-grade epithelial neoplasm, and GA-FGM should be categorized as an aggressive variant of GEN-FGML that demonstrated high-grade epithelial neoplasm (Type 2 > 1, 3). The frequent presence of GNAS mutation was a characteristic genetic feature of GEN-FGML (7/34, 20.6%; OGA 1/3, 33.3%; GA-FG 3/24, 12.5%; GA-FGM 3/7, 42.9%) in mutation analysis using next-generation sequencing. CONCLUSIONS: We have established a new histopathological classification of GEN-FGML and propose a new lineage of gastric epithelial neoplasm that harbors recurrent GNAS mutation. This classification will be useful to estimate the malignant potential of GEN-FGML and establish an appropriate standard therapeutic approach.

BRAF/MEK inhibitor-associated nephrotoxicity in a real-world setting and human kidney cells.

Acute kidney injury (AKI) associated with cancer chemotherapy can be life-threatening. Inhibitors of rapidly accelerated fibrosarcoma kinase B (BRAF)-mutants and mitogen-activated extracellular signal-regulated kinase (MEK) administered as combination therapy are effective against BRAF-mutant melanoma, but drug-associated AKI events were reported after marketing. Here, we examined the nephrotoxicity of two BRAF inhibitors, vemurafenib and dabrafenib, and two MEK inhibitors, cobimetinib and trametinib, in a real-world setting and human kidney cells. Target drug-associated AKI signals were detected by reporting odds ratio (ROR) derived from report data in the Food and Drug Administration Adverse Events Reporting System database. In-vitro cytotoxicity was evaluated in proximal renal tubular epithelial cells (RPTEC), glomerular endothelial cells (GEnC), and glomerular epithelial cells (GEpC). AKI RORs associated with vemurafenib [ROR, 3.28; confidence interval (CI), 2.91-3.69] and cobimetinib (ROR, 4.40; CI, 3.55-5.45) were higher than those associated with dabrafenib (ROR, 1.35; CI, 1.15-1.60) and trametinib (ROR, 1.32; CI, 1.11-1.56). Vemurafenib reduced cell viability and increased cell death in RPTEC and GEpC at 10 µM, which was below the mean maximum concentration in blood under steady-state condition [115.7 µM (56.7 µg/mL)]. No vemurafenib-associated cytotoxicity was detected in GEnC. Mean maximum concentrations of cobimetinib, dabrafenib and trametinib did not induce cell death. This work revealed that vemurafenib had stronger cytotoxic effects on tubular and glomerular epithelial cells than the other BRAF and MEK inhibitors. Hence, we recommend careful monitoring for clinical signs of kidney injury in patients treated with vemurafenib.

Endoscopic and Clinicopathological Features of Superficial Non-Ampullary Duodenal Tumor Based on the Mucin Phenotypes.

AIMS: We aimed to clarify the endoscopic/clinicopathological features of superficial non-ampullary duodenal epithelial tumors (SNADETs) based on their mucin phenotypes. METHODS: We analyzed 62 SNADET lesions and classified them based on mucin phenotypic expression. Endoscopic and clinicopathological findings were compared according to mucin phenotypes. RESULTS: Eleven lesions had the gastric phenotype (GP) and 43 lesions had the intestinal phenotype (IP). All GP lesions were located in the first portion of the duodenum, while most IP lesions (72.1%) were located in the second portion (p < 0.01). Tumor size was significantly larger in the GP than in the IP group (14.4 mm vs. 10.2 mm, p < 0.05). Reddish color (72.7% in GP vs. 37.2% in IP, p < 0.05), type 0-I (72.7% vs. 11.6%, p < 0.01), lobular/granular pattern (81.8% vs. 4.7%, p < 0.01), and category 4/5 in Vienna classification (81.8% vs. 30.2%, p < 0.01) were observed significantly more often in the GP than in the IP group. Regarding findings of magnifying endoscopy with narrow-band imaging (M-NBI), white opaque substance (22.2% in GP vs. 89.7% in IP, p < 0.01) and light blue crest (0% vs. 43.6%, p < 0.05) were significantly less frequently observed in the GP group. Oval-shaped marginal epithelium (66.7% vs. 17.9%, p < 0.01), dense pattern (55.6% vs. 2.6%, p < 0.01), and dilatation of the intervening part (100% vs. 12.8%, p < 0.01) were more frequently observed in the GP group. CONCLUSIONS: SNADETs showed distinct endoscopic/clinicopathological features according to the mucin phenotype. Tumor location, coloration, macroscopic type, and endoscopic findings including M-NBI are useful to distinguish the mucin phenotypes of SNADETs.

Clinicopathological features of alpha-fetoprotein producing early gastric cancer with enteroblastic differentiation.

AIM: To investigate clinicopathological features of early stage gastric cancer with enteroblastic differentiation (GCED). METHODS: We retrospectively investigated data on 6 cases of early stage GCED and 186 cases of early stage conventional gastric cancer (CGC: well or moderately differentiated adenocarcinoma) who underwent endoscopic submucosal dissection or endoscopic mucosal resection from September 2011 to February 2015 in our hospital. GCED was defined as a tumor having a primitive intestine-like structure composed of cuboidal or columnar cells with clear cytoplasm and immunohistochemical positivity for either alpha-fetoprotein, Glypican 3 or SALL4. The following were compared between GCED and CGC: age, gender, location and size of tumor, macroscopic type, ulceration, depth of invasion, lymphatic and venous invasion, positive horizontal and vertical margin, curative resection rate. RESULTS: Six cases (5 males, 1 female; mean age 75.7 years; 6 lesions) of early gastric cancer with a GCED component and 186 cases (139 males, 47 females; mean age 72.7 years; 209 lesions) of early stage CGC were investigated. Mean tumor diameters were similar but rates of submucosal invasion, lymphatic invasion, venous invasion, and non-curative resection were higher in GCED than CGC (66.6% vs 11.4%, 33.3% vs 2.3%, 66.6% vs 0.4%, 83.3% vs 11% respectively, P < 0.01). Deep submucosal invasion was not revealed endoscopically or by preoperative biopsy. Histologically, in GCED the superficial mucosal layer was covered with a CGC component. The GCED component tended to exist in the deeper part of the mucosa to the submucosa by lymphatic and/or venous invasion, without severe stromal reaction. In addition, Glypican 3 was the most sensitive marker for GCED (positivity, 83.3%), immunohistochemically. CONCLUSION: Even in the early stage GCED has high malignant potential, and preoperative diagnosis is considered difficult. Endoscopists and pathologists should know the clinicopathological features of this highly malignant type of cancer.

Effects of dexmedetomidine on hemodynamics and respiration in intubated, spontaneously breathing patients after endoscopic submucosal dissection for cervical esophageal or pharyngeal cancer.

PURPOSE: We evaluated the hemodynamic and respiratory effects of dexmedetomidine in intubated, spontaneously breathing patients after endoscopic submucosal dissection (ESD) for cervical esophageal or pharyngeal cancer. METHODS: This retrospective study included 129 patients aged 66.5 ± 8.3 years, who underwent ESD under general anesthesia, and who were kept intubated overnight to prevent airway obstruction, receiving sedation with dexmedetomidine. Constant dexmedetomidine infusion at 0.51 ± 0.16 µg/kg/h was started intraoperatively (n = 109) or postoperatively (n = 20), following (n = 29) or not following (n = 100) loading doses, and continued until extubation. Hemodynamic and respiratory variables, and Richmond Agitation-Sedation Scale (RASS) score, were recorded. RESULTS: Postoperatively, 129 patients remained intubated while breathing spontaneously for 16.4 ± 3.3 h, and 124 patients could be sedated solely with dexmedetomidine, whereas 5 required rescue sedatives. During infusion, blood pressure decreased progressively until 12 h, whereas heart rate decreased only at 3 h. Hemodynamic alterations during dexmedetomidine infusion greatly depended not only on its hemodynamic effects but also on baseline hemodynamics before anesthesia. No serious adverse effect was noted. CONCLUSION: Dexmedetomidine in intubated, spontaneously breathing patients after ESD was safe and effective. Patient baseline hemodynamics could significantly affect hemodynamics during drug infusion. Without loading doses, plasma drug concentrations were expected to increase progressively. A progressive decrease in blood pressure and unchanged heart rate after an initial decrease suggested that hemodynamic effects of dexmedetomidine in our patients might differ from those reported in young volunteers, although further studies are required to elucidate these points.

Docetaxel, cisplatin and 5-fluorouracil adjuvant chemotherapy following three-field lymph node dissection for stage II/III N1, 2 esophageal cancer.

To determine the efficacy of postoperative adjuvant chemotherapy with docetaxel + cisplatin + 5-fluorouracil (DCF) in lymph node metastasis-positive esophageal cancer, we retrospectively analyzed 139 patients with stage II/III (non-T4) esophageal cancer with lymph node metastasis (1-6 nodes), who did not receive preoperative treatment and underwent three-field lymph node dissection in the Juntendo University Hospital between December, 2004 and December, 2009. The tumors were histologically diagnossed as squamous cell carcinoma. The patients were divided into two groups, a surgery alone group (S group, 88 patients) and a group that received postoperative DCF therapy (DCF group, 51 patients). The disease-free and overall survival were compared between the groups and a multivariate analysis of prognostic factors was performed. The same analysis was performed for cases classified as N1 and N2, according to the TNM classification. There were no significant differences between the S and DCF groups regarding clinicopathological factors other than intramural metastasis and main tumor location. The presence of intramural metastasis, blood vessel invasion and the number of lymph nodes were identified as prognostic factors. The 5-year disease-free and overall survival were 55.8 and 57.3%, respectively, in the S group and 52.8 and 63.0%, respectively, in the DCF group. These differences were not considered to be statistically significant (P=0.789 and 0.479 for disease-free and overall survival, respectively). Although there were no significant differences in disease-free and overall survival between the S and DCF groups in N1 cases, both disease-free and overall survival were found to be better in the DCF group (54.2 and 61.4%, respectively) compared to the S group (29.6 and 28.8%, respectively) in N2 cases (P=0.029 and 0.020 for disease-free and overall survival, respectively). Therefore, postoperative adjuvant chemotherapy with DCF was shown to improve disease-free and overall survival in moderate lymph node metastasis-positive cases (N2), suggesting that the DCF regimen may be effective as postoperative adjuvant chemotherapy for patients with lymph node metastasis from esophageal cancer.

Current status of primary malignant melanoma of the esophagus: clinical features, pathology, management and prognosis.

Primary malignant melanoma of the esophagus (PMME) is a rare disease with an extremely poor prognosis. Up to 2011, approximately 300 cases had been reported worldwide. The average age of onset is 60.5 years old, with a prevalence of males (2:1). A typical finding of PMME is a lobular or polyploid, well-circumscribed and pigmented tumor, partly covered with normal mucosa. PMME represents various colors depending on its melanin quantity and commonly coexists with intramural metastases, melanocytosis or melanoma in situ. The tumor is located from the middle to lower thoracic esophagus. The accuracy of diagnosis from biopsy is approximately 80%, because many cases are misdiagnosed as a poorly differentiated carcinoma because of the absence of melanin granules. A definite diagnosis was made by immunohistochemical examination with positive results of S100 protein, HMB45 and neuron-specific enolase. PMME has a highly metastatic potential, and the incidence of distant metastasis at the initial diagnosis is around 40-80%. A metastatic tumor from cutaneous malignant melanoma is another pigmented esophageal tumor to be considered when making the differential diagnosis for PMME. Junctional activity with melanotic cells in the adjacent epithelium and the presence of in situ melanoma and/or a satellite tumor without a previous history of cutaneous melanoma are definitive. Most of the reported patients were treated with radical esophagectomy, which is believed to be an effective approach for localized PMME. Five-year survival rates have been achieved in 37% recently, while adjuvant therapy has not been proven to increase overall survival but plays a palliative role.

[Trans-thoracic esophagectomy with 3-field lymph nodes dissection].

Although open-chest surgery is the mainstay treatment for esophageal cancer, the understanding of the context of the surgery differs in Japan and the rest of the world. Three-field lymph node dissection has been unique to Japan, although some reports on its benefits are emerging elsewhere. In addition to three-field lymph node dissection, various efforts are made during surgical procedures to reduce complications at high-volume Japanese healthcare institutions.

Lymphatic invasion according to D2-40 immunostaining is a strong predictor of nodal metastasis in superficial squamous cell carcinoma of the esophagus: algorithm for risk of nodal metastasis based on lymphatic invasion.

In squamous cell carcinoma (SCC) of the esophagus, D2-40 immunostaining has recently been used to detect lymphatic invasion, but invasion detected using D2-40 immunostaining for a predictor of nodal metastasis was controversial. Therefore, the usefulness of detecting lymphatic invasion by D2-40 immunostaining as a predictor of nodal metastasis was examined in superficial (mucosal and submucosal) SCC of the esophagus. A total of 115 superficial SCC of the esophagus were examined on immunohistochemistry using D2-40. It was found that lymphatic invasion demonstrated on D2-40 immunostaining was mainly detected in the lamina propria mucosa. Lymphatic invasion was found in 37 cases and the invasion detected in the entire tumor tissue was statistically correlated with nodal metastasis. Based on the lymphatic invasion according to D2-40 immunostaining, an algorithm was devised for the risk (low, intermediate and high) of nodal metastases in superficial SCC in the esophagus. In conclusion, the detection of lymphatic invasion on D2-40 immunostaining in tumor tissue is a strong predictor for nodal metastasis in superficial SCC of the esophagus. Lymphatic invasion was found mainly in the lamia propria mucosa, thus the devised algorithm is useful for determining the optimal treatment strategy after endoscopic mucosal resection for esophageal SCC.

[Controversies in esophageal cancer surgery].

In esophageal cancer treatment, the choice of treatment modality and the indications and extent of lymph node dissection surgery are controversial. In terms of the biological characteristics, esophageal cancer is more virulent than any other gastrointestinal malignancy. The distribution of lymph node metastases is very wide, extending from the neck to abdominal regions, and the sizes of lymph node metastases are very small. Almost two-thirds of all metastatic lymph nodes showed minute metastases less than 5 mm in diameter. In patients with superficial cancer with only submucosal invasion, lymph nodes metastases were found in both the upper mediastinal and paracardial areas in up to 27% cases. Furthermore, the accuracy of preoperative diagnosis of lymph node metastasis in esophageal cancer is still unsatisfactory. False negative rates in preoperative diagnosis of lymph node metastases are 14% in the neck area, 36% in the mediastinal area, and 34% in the abdominal area. Therefore, in order to cure esophageal cancer by surgery, wide, precise and complete removal of possible metastatic lymph nodes is essential. It is at this time that the quality assurance of surgery is indispensable in reducing morbidity and mortality, and in improving the patient survival. Because both surgery and chemoradiotherapy are local treatments, we must recognize the limitation of these therapeutic modalities. To improve overall survival of esophageal cancer patients, we have to make a more concentrated effort toward the systemic control of this disease.

[Surgery for benign submucosal tumors of the esophagus (leiomyoma and hemangioma)].

Among the submucosal tumors of the esophagus, leiomyoma is the most frequently found. Esophageal leiomyoma usually originates from the muscle layer of the esophageal wall and grows spirally around the esophageal axis. In the surgical treatment of leiomyoma, we enucleate the tumor through video-assisted thoracic surgery. When we enucleate leiomyoma, we must be very careful to aviod perforation of the esophageal mucosa. Esophageal hemangioma is a relatively rare disease. The location of this disease is mainly within the submucosal layer, without invading the muscle layer proper. After confirming the localization within the mucosa or submucosa with endoscopic ultrasonography, esophageal hemangioma can be resected safely using the endoscopic mucosal resection technique. In the treatment of benign esophageal submucosal tumors, "informed consent" is as essential as in esophageal cancer surgery. We have no absolute criteria concerning the indications for surgery for benign esophageal submucosal tumors. We must give reasons why the operation is necessary and indicated to the patients. Surgical treatment of esophageal submucosal tumors should be as minimally invasive as possible.