Comparison of off-clamp microwave scissors-based sutureless partial nephrectomy versus on-clamp conventional partial nephrectomy in a canine model

Objectives

To compare the usefulness and safety of off-clamp microwave scissors-based sutureless partial nephrectomy (MSPN) with on-clamp conventional partial nephrectomy (cPN) in dogs.

Methods

We performed off-clamp MSPN using microwave scissors (MWS) in six dogs, and on-clamp cPN in three dogs, in two-stage experiments. The bilateral kidney upper poles were resected via a midline incision under general anesthesia. After 14 days of follow-up, the lower pole resections were performed. The renal calyces exposed during renal resections were sealed and transected using MWS in off-clamp MSPN and were sutured in on-clamp cPN. In the off-clamp MSPN group, the generator's power output of MWS was set as either 50 W or 60 W for each kidney side. We compared the procedure time (PT), ischemic time (IT), blood loss (BL), and normal nephron loss (NNL) between the two techniques using the Mann-Whitney U-test.

Results

We successfully performed 24 off-clamp MSPNs and 12 on-clamp cPNs. The off-clamp MSPN was significantly superior to on-clamp cPN in avoiding renal ischemia (median IT, 0 min vs. 8.6 min, p < 0.001) and reducing PT (median PT, 5.8 min vs. 11.5 min, p < 0.001) and NNL (median NNL, 5.3 mm vs. 6.0 mm, p = 0.006) with comparable BL (median BL, 20.9 ml vs. 23.2 ml, p = 0.804). No bleeding and major urine leakage were noted during the reoperations.

Conclusions

Off-clamp MSPN outperforms on-clamp cPN in lowering the risks of postoperative renal function impairment in dogs.

Feasibility of Microwave Scissors-Based Off-Clamp Laparoscopic Partial Nephrectomy in a Porcine Model

OBJECTIVES

To assess the feasibility of off-clamp laparoscopic partial nephrectomy using microwave scissors.

METHODS

We performed transperitoneal laparoscopic partial nephrectomy, without hilar clamping or renorrhaphy, using only microwave scissors for renal resection in a porcine model. For each kidney, 2 types of procedures were performed: a middle pole resection excising an area of 2-cm diameter and approximately 1-cm depth and a lower pole resection at the level of the lower polar line. The renal calyces exposed during renal resection were sealed and transected using microwave scissors. After 3 days of follow-up, the pigs were reoperated to inspect for postoperative complications. Euthanasia was performed to collect the remaining kidneys for histopathological examination.

RESULTS

Ten procedures were successfully performed, without hilar clamping or suturing of the renal calyces and parenchyma, in 5 kidneys from 3 pigs. The median resecting time, blood loss, and lateral thermal injury were 23.2 min, 47.1 mL, and 6.8 mm in the middle pole resection, and were 15.1 min, 26.5 mL, and 6.9 mm in the lower pole resection, respectively. No complications were noted during reoperation, such as postoperative hemorrhage and major urine leakage. Extravasation occurred in 2 middle pole resections and 3 lower pole resections during retrograde pyelogram. Hematoxylin and eosin staining revealed thermal injury characterized by tissue microwave fixation in the near zone and acute coagulative necrosis in the intermediate zone.

CONCLUSIONS

Microwave scissors-based off-clamp laparoscopic partial nephrectomy is feasible in pigs and can be used for clinical applications.

Feasibility of Microwave-Based Scissors and Tweezers in Partial Hepatectomy: An Initial Assessment on Canine Model

Purpose: This study aimed to assess the feasibility of partial hepatectomy (PH) simplified by using microwave-based devices in animal experiments.

Methods: PH was performed on 16 beagles using either Acrosurg Scissors (AS) or Acrosurg Tweezers (AT) without hepatic pedicle (HP) control. Parenchymal transection time, Glissonean pedicle (GP) seal time, bleeding volume, bile leak, and burst pressure were recorded. Probable complications were investigated after 4 weeks.

Results: Transection time (6.5 [6.0–7.6] vs. 11.8 [10.5–20.2] min, p < 0.001) with AT were significantly shorter than with AS. GP sealing times (60 [55–60] vs. 57 [46–91] s, p = 0.859) by both devices were nearly similar. Bleeding volume in the AT group was approximately one-fourth of that in the AS group (6.7 [1.4–22] vs. 28.8 [5.8–48] mL, p = 0.247). AT created higher burst pressure on the bile duct stumps (p = 0.0161). The two devices did not differ significantly in morbidity and mortality after four-week follow-up.

Conclusion: Acrosurg devices achieved a safe PH without HP control owing to microwave-based sealing. AS could be used alone in PH, whereas the clamp-crushing function of AT seemed more advantageous in reducing the transection time and blood loss.

Vessel-Sealing Capability of Novel Microwave Sealer: Experimental Study in Animal Models

Background. Ultrasonically activated dissectors (UADs) and radiofrequency-based devices have been considered excellent surgical devices because of their reliability and flexibility. Meanwhile, microwave-based devices have demonstrated potential with their unique heating mechanism. This study aims to compare the sealing function of a newly invented forceps-like microwave sealer (MS) with that of currently available UADs. Materials and Methods. MS and 2 examples of UADs (Harmonic Focus+ [HF+] and Sonicision [SNC]) were employed to perform mesenterectomies (in vivo) and sealing sizable vessels (ex vivo). Vessel diameter, seal time, burst pressure (BP), sealing completion, and instrument sticking were recorded. The samples underwent histological investigation for thermal damage evaluation. Results. During mesenterectomies, MS required 3 seconds and 30 W to secure a complete seal. The BP achieved by the MS seal was higher than that of HF+ and SNC on arteries (851 ± 203.7 vs 682.4 ± 287.3, P < .05; vs 833.1 ± 251.2 mmHg, P = .4523, respectively) but was not statistically different on veins (324.9 ± 203.5 vs 460.1 ± 320.3 vs 508.3 ± 350.7 mmHg, P = .215). In all trials, MS caused less sticking but exhibited similar heat-induced alterations to UADs. MS's thermal spread was not statistically more extended than that of UADs on either arteries or veins. Conclusions. MS was capable of not only sealing tiny vessels but also achieving high-pressure endurance on sizable vessels. Its forceful grasping and synchronous heating process helped create solid stumps with an acceptable thermal spread.

Magnetic resonance and ultrasound image-guided navigation system using a needle manipulator

PURPOSE

Image guidance is crucial for percutaneous tumor ablations, enabling accurate needle-like applicator placement into target tumors while avoiding tissues that are sensitive to injury and/or correcting needle deflection. Although ultrasound (US) is widely used for image guidance, magnetic resonance (MR) is preferable due to its superior soft tissue contrast. The objective of this study was to develop and evaluate an MR and US multi-modal image-guided navigation system with a needle manipulator to enable US-guided applicator placement during MR imaging (MRI)-guided percutaneous tumor ablation.

METHODS

The MRI-compatible needle manipulator with US probe was installed adjacent to a 3 Tesla MRI scanner patient table. Coordinate systems for the MR image, patient table, manipulator, and US probe were all registered using an optical tracking sensor. The patient was initially scanned in the MRI scanner bore for planning and then moved outside the bore for treatment. Needle insertion was guided by real-time US imaging fused with the reformatted static MR image to enhance soft tissue contrast. Feasibility, targeting accuracy, and MR compatibility of the system were evaluated using a bovine liver and agar phantoms.

RESULTS

Targeting error for 50 needle insertions was 1.6 ± 0.6 mm (mean ± standard deviation). The experiment confirmed that fused MR and US images provided real-time needle localization against static MR images with soft tissue contrast.

CONCLUSIONS

The proposed MR and US multi-modal image-guided navigation system using a needle manipulator enabled accurate needle insertion by taking advantage of static MR and real-time US images simultaneously. Real-time visualization helped determine needle depth, tissue monitoring surrounding the needle path, target organ shifts, and needle deviation from the path.

Functional Evaluation of a Novel Microwave Surgical Device in a Canine Splenectomy Model

Aim: Partial splenectomy remains a difficult procedure even with the assistance of a sealing system. Recently, a scissor-like microwave energy device (Acrosurg) that provides seamless coagulation and manual cutting has been applied in surgery. The objective of this study is to evaluate the surgical capabilities of Acrosurg in partial splenectomy. Materials and Methods: Acrosurg and Harmonic Focus (HF) were employed for partial splenectomy in dogs without prior ligation of vessels. Cutting time, cutting area, and bleeding were recorded. Lateral thermal injury (LTI), possible complications was observed immediately and after 4 weeks. Results: The manual cutting mechanism of Acrosurg required a longer cutting time compared with the automatic cutting mode of HF (301.5 [243.2-527] vs. 114.5 [106.0-135.0] sec, p < 0.01). There was no statistical difference in cutting area or bleeding cases. Acrosurg achieved complete hemostasis in all cases, whereas the HF group failed to stop bleeding in two of the eight cases. The Acrosurg group exhibited a similar LTI compared with the HF group (3.0 [2.4-3.4] vs. 2.7 [2.3-2.9] mm, p = 0.151), but the LTI of the Acrosurg group tended to shrink more after 4 weeks (1.2 [1.0-1.3] vs. 1.7 [1.3-1.9] mm, p < 0.05). Conclusions: A microwave energy device enabled a partial splenectomy without vessel ligation. The combination of manual cutting and sealing capability helps not only provide an appropriate seal time by adjusting cutting timing adaptively but also potentially stop bleeding by using a microwave heating process unlike other energy devices.

[A Case of Gastric Cancer Underwent Two-Stage Gastrectomy after Chemotherapy-Induced Perforation]

A 70's man presenting with a chief complaint of stomachache was found to have advanced gastric cancer with a deep ulcer and some lymph-node metastases. We decided performing a curative operation after 2 courses of S-1 plus cisplatin. On the first course day 13 of chemotherapy, he complained of severe epigastralgia, and we diagnosed as generalized peritonitis due to perforation of gastric cancer. We performed an urgent laparoscopic operation, which made perforation simple closure and omentopexy. Curative distal gastrectomy with D2 lymph node dissection was successfully performed on postoperative day 16.

Feasibility and safety of hyperthermic intraperitoneal chemotherapy using 5-fluorouracil combined with cisplatin and mitomycin C in patients undergoing gastrectomy for advanced gastric cancer

BACKGROUND AND OBJECTIVES

We conducted a dose-finding study for 5-fluorouracil (5-FU) administered with cisplatin (CDDP) and mitomycin C (MMC) to find an improved regimen for hyperthermic intraperitoneal chemotherapy (HIPEC) for advanced gastric cancer (GC).

METHODS

The appropriate HIPEC regimen previously determined in vitro was 5-FU (200 µg/mL), MMC (2 µg/mL), and CDDP (10 µg/mL) at hyperthermic conditions (42°C) for 30 min. This was a clinical study to determine the recommended dose of 5-FU in combination with MMC and CDDP at 42°C for 30 min and to evaluate HIPEC safety in patients at high risk of developing peritoneal metastases following GC surgery.

RESULTS

Twelve patients were treated with surgery plus HIPEC using 5-FU at 0, 500, 750, and 1000 mg combined with MMC (10 mg) and CDDP (50 mg) in the perfusate (5 L). Dose-limiting toxicities did not develop until 1000 mg 5-FU was reached. Four patients experienced grade 1 or 2 adverse events. The recommended dose was 1000 mg 5-FU/5 L perfusate. Eight (66.7%) patients demonstrated no recurrence of peritoneal metastases; 5-year overall survival rate was 83.3%.

CONCLUSION

Gastrectomy and HIPEC with MMC, CDDP, and 5-FU is feasible, safe, and may protect against peritoneal metastasis following surgery for advanced GC.

Abstract 3743: Magnetic resonance imaging shrinkage patterns after neoadjuvant chemotherapy for breast carcinomas: Correlation with molecular subtypes

Background: Neoadjuvant chemotherapy (NAC) is widely performed for patients with locally advanced breast carcinomas. It is important to obtain precise information using imaging modalities about the distribution of residual carcinomas after NAC to predict the success of breast conserving surgery. However, the relationship between magnetic resonance imaging (MRI) shrinkage patterns and molecular subtypes of breast carcinomas has not yet been investigated.

Methods: We analyzed the MRI shrinkage and pathological patterns of residual carcinomas after NAC in 54 consecutive breast carcinomas. The shrinkage patterns were classified into five categories: Type I and II (concentric shrinkage with or without any surrounding lesion), type III (shrinkage with residual multinodular lesions), type IV (diffuse contrast enhancement in the entire quadrant), and non-visualization.

Results: The most common MRI shrinkage pattern was type I (39%) followed by non-visualization (26%). The most common pathological shrinkage pattern was type III (33%), followed by type II (28%) and non-visualization (22%). The concordance rates of the MRI patterns of non-visualization and type I were significantly lower than those of the MRI patterns of type II, III, and IV (p = 0.018). Moreover, in the luminal subtypes, the concordance rates of the MRI patterns of non-visualization and type I were significantly lower than those of the MRI patterns of type II, III, and IV (p = 0.026); however, in the non-luminal subtypes, this correlation was not significant. Conclusions: The results of the present study suggest that the cases with MRI shrinkage patterns of non-visualization and type I require caution regarding the surgical margins compared with the other types, especially the luminal subtypes.

Citation Format: Tsuyoshi Mori, Kaori Tomida, Mina Kitamura, Sachiko Sakai, Yuki Kawai, Tomoharu Shimizu, Tomoko Umeda, Tomoyuki Ueki, Sachiko Kaida, Toru Miyake, Hiroya Iida, Hiroya Akabori, Naomi Kitamura, Tsuyoshi Yamaguchi, Hiromichi Sonoda, Shigeyuki Naka, Masaji Tani. Magnetic resonance imaging shrinkage patterns after neoadjuvant chemotherapy for breast carcinomas: Correlation with molecular subtypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3743. doi:10.1158/1538-7445.AM2017-3743

Pathophysiology and therapeutic strategies for peritoneal recurrence after gastric cancer surgery

4050

Background: We recently showed that cancer cells, with proliferative and tumorigenic potential, can spill into the peritoneal cavity during curative (R0) gastric cancer (GC) surgery, which is associated with peritoneal recurrence (PM). To elucidate the pathophysiology of PM, the relationship between spilled cancer cells and cancer stem cells was evaluated. Furthermore, to identify a therapeutic strategy for PM, the prognostic impact of hyperthermic intraperitoneal chemotherapy (HIPEC) following GC surgery with spillage of cancer cells was evaluated. Methods: Patients with advanced GC (≥pT2 [MP]) who underwent R0 gastrectomy between 2010 and 2015 were enrolled. Ninety-four consecutive patients with negative results in peritoneal cytology and cancer cell culture (CCC [-]) following peritoneal washing (PW) before GC surgery were included. Spilled cancer cells in PW after GC surgery (PW-Post) were examined to identify any CD44-positive cancer stem-like cells associated with cancer metastasis. Based on the PW-Post CCC results, associations between HIPEC and recurrence-free survival (RFS), or overall survival (OS) were evaluated. HIPEC was performed following GC surgery using CDDP, MMC, and 5-FU in 5 L saline maintained at 42˚C for 30 min. Results: Spilled cancer cells included CD44+ cancer stem-like cells. In 48 patients with PW-Post positive CCC (CCC [+]), the number of patients with pStage I, II, and III were 4, 7, and 15, respectively, in those who received HIPEC (n = 26), and 3, 9, and 10, respectively, in those who did not (n = 22). Among patients with CCC (+), the 5-year peritoneal RFS, hepatic RFS, and lymph node RFS rates were 93.3%, 100%, and 68.5%, respectively, in patients who received HIPEC, and 56.7%, 35.6%, and 66.7%, respectively, in those who did not ( P = 0.008, P = 0.008, and P= 0.24, respectively). Among patients with PW-Post CCC (-), none developed recurrence, regardless of whether they received HIPEC (n = 28) or not (n = 18). Conclusions: The results show that PW-Post CCC is a promising predictive biomarker for recurrence after R0 GC surgery. Adjuvant HIPEC performed with R0 GC surgery showed preventive effects on peritoneal and hepatic recurrence and survival benefits for patients with PW-Post CCC (+).

Predictive detection areas for identifying additional MRI-detected breast lesions on second-look ultrasonography

PURPOSE

Identifying an additional MRI-detected breast lesion on second-look ultrasonography (US) is technically challenging because of lesion displacement with the patient's position change. The aim of this study is to help identify MRI-detected lesions on second-look US by developing a probing area, called "the predictive detection area" (PDA), and by assessing the PDA.

METHODS

We measured the nipple-to-lesion distances (NLDs) for 16 breast lesions on prone- and supine-position MRI sets and calculated the difference and angle between the two NLD vectors, representing the lesion displacement. The minimum and maximum differences and angles were chosen to form the PDA. Another 22 breast lesions, detected in the prone MRI, were identified on US by probing the PDA to evaluate the probability of existence.

RESULTS

The width between the minimum and maximum differences in two NLDs and the angle to form the PDA for the upper-inner, upper-outer, and lower-outer quadrants were 23.0 mm and 95.0°, 29.0 mm and 41.0°, and 18.0 mm and 17.0°, respectively. The respective probabilities of existence were 100, 80, and 100%.

CONCLUSIONS

The PDA had a high probability of existence and was acceptably accurate; therefore, the PDA in a second-look US has the potential to help operators to quickly identify additional MRI-detected lesions.

[Salvage Surgery after CRT for Advanced Esophageal Cancer Resulting in a Pathological Complete Response and More Than Five Years' Survival]

A 62-year-old woman visited our hospital because of dysphagia. She was diagnosed with upper-middle esophageal type 4 cancer, which was 9 cm in length, according to the results of endoscopy. Squamous cell carcinoma was demonstrated using endoscopic biopsy. A CT scan revealed that the tumor had directly invaded into the trachea(cT4). Chemoradiotherapy(CRT) (5-FU and CDDP with 50 Gy of radiation)was administered. Although CT after CRT resulted in shrinkage of the tumor and no further tracheal invasion, esophageal stenosis remained. Therefore, salvage surgery(subtotal esophagectomy with 3-field lymph node dissection)was performed. Pathologically, no carcinoma cells were found in the resected specimen and a com- plete response(grade 3)was diagnosed. The patient received adjuvant chemotherapy(tegafur/uracil at 300mg/day per os) for 1 year. The patient is alive with no relapse of carcinoma more than 5 years after the first treatment.

[A Case of Breast Metastasis of Eccrine Porocarcinoma]

An 80's woman was diagnosed with eccrine porocarcinoma of the head in 2010.T he tumor was removed surgically but relapsed in the cervical and axillary lymph nodes 2 years later.The patient underwent surgery, and received systemic chemotherapy and radiation.Chest CT after treatment revealed an irregular mass and thickened skin in the left breast.Core needle biopsy specimens were used to diagnose metastasis of eccrine porocarcinoma.A wide excision with a 1 cm margin was performed under local anesthesia.After surgery, supraclavicular lymph node recurrence was detected.The patient received palliative care because there was no effective treatment available.Eccrine porocarcinoma is a rare malignant tumor of the intraepidermal sweat duct.Breast metastasis from malignant disease is also rare.To our knowledge, breast metastasis of eccrine porocarcinoma has not been reported.

[Clinical Evaluation of Hyperthermic Intraperitoneal Chemotherapy(HIPEC)in Colorectal Cancer Patients at High Risk of Peritoneal Recurrence]

PURPOSE

We herein report the clinical outcomes of hyperthermic intraperitoneal chemotherapy(HIPEC)in patients at high risk of colorectal peritoneal metastasis.

PATIENTS AND METHODS

We enrolled 21 patients with advanced colorectal cancer who were received HIPEC between 2009 and 2014. Retrospectively, we evaluated the short-term and long-term outcomes of these cases.

RESULTS

We performed HIPEC for 12 patients with primary cancer and 9 with recurrent cancer. Perioperative complications characteristic of HIPEC did not occur. Seventeen patients(81%)had postoperative recurrence, 5 of whom had a peritoneal recurrence, and all of them already had synchronous peritoneal metastasis at the time of HIPEC. Patients with a higher peritoneal cancer index(PCI)had a tendency towards a higher rate of peritoneal recurrence than those with a lower PCI(11[median]vs 4; p=0.08).

[Stage IV Gastric Cancer with Positive Peritoneal Washing Cytology or Peritoneal Dissemination Was Successfully Treated with Gastrectomy and Hyperthermic Intraperitoneal Chemotherapy(HIPEC)Followed by Systemic Chemotherapy - A Report of Two Cases]

Survival of Stage IV gastric cancer is poor. We report 2 cases of Stage IV gastric cancer with positive peritoneal washing cytology or peritoneal dissemination that were successfully treated with gastrectomy and hyperthermic intraperitoneal chemotherapy( HIPEC)followed by systemic chemotherapy. Case 1: A 59-year-old woman. She was diagnosed with advanced gastric cancer and underwent gastrectomy with HIPEC. Her peritoneal washing cytology was positive during the gastrectomy. After the surgery, she underwent chemotherapy consisting of 8 courses of combination S-1 plus CPT-11 and 19 courses of PTX. It has been 5 years and 7 months since she had the surgery and she survives without recurrence of the cancer. Case 2: A 60-year-old woman. She was diagnosed with advanced gastric cancer and peritoneal dissemination(peritoneal cancer index: 3 points). She underwent gastrectomy, hemi-colectomy, and HIPEC. After the surgery, she underwent chemotherapy, 35 courses of combination S-1 plus PSK/DOC, and 13 courses of S-1 plus PSK. It has been 5 years since her surgery and she survives without exacerbation of the cancer. These cases suggest a gastrectomy and HIPEC followed by systemic chemotherapy may represent an effective treatment for advanced gastric cancer with a small amount of peritoneal metastasis.

[Surgery for Multiple Gastrointestinal Stromal Tumors of the Small Intestine in Patients with Neurofibromatosis Type 1 - A Report of Three Cases]

We report 3 cases of multiple GIST of the small intestine in 3 patients with NF1 who have been followed for over 5 years. All patients presented with melena, and tumors of the small intestine suspected to be GIST were found on endoscopy. We performed partial resections of the small intestine for all 3 patients. After surgery, 1 patient had residual tumors that gradually enlarged during 8 year 2 months and another had residual tumors that have been stable for 8 years. In the third patient, we resected all the tumors, and there has been no sign of recurrence in 6 year 1 month.

Lymphoepithelial cyst with sebaceous glands of the pancreas: a case report

Background

Lymphoepithelial cyst (LEC) of the pancreas is a rare benign tumor. LEC with sebaceous glands of the pancreas is extremely rare, and its histogenesis remains unclear.

Case presentation

We present a 66-year-old man with an incidental finding of a cystic lesion at the neck of the pancreas. Pancreatic juice cytology results and elevated serum carbohydrate antigen 19-9 and Dupan-2 levels indicated that the cyst was a potential adenocarcinoma. Therefore, a pancreaticoduodenectomy was performed. Macroscopically, the tumor was a unilocular cyst with a thin transparent wall, filled with soft yellow material. Pathological findings showed that the cyst was lined with squamous epithelium, accompanied by dense lymphoid tissue with scattered germinal centers. There were no hair follicles, but sebaceous glands were present in the lymphoid tissue just beneath the squamous epithelium. Therefore, the histopathological diagnosis was an LEC with sebaceous glands of the pancreas. Furthermore, the squamous epithelium surrounding the cyst was pathologically continuous with the tubular structure, indicating that the tubular structure transitioned into the squamous epithelium.

Conclusions

We report an extremely rare case of LEC with sebaceous glands of the pancreas. Moreover, the pathological findings, which showed that the tubular structure transitioned into the squamous epithelium, suggested that this was squamous metaplasia. In order to investigate the histogenesis of LEC of the pancreas, the pathological findings must be evaluated.

ABCG2 expression in colorectal adenocarcinomas may predict resistance to irinotecan

Irinotecan is a key drug for patients with advanced and recurrent colorectal carcinoma. However, the efficacy of irinotecan is not sufficient; partly, as there is no useful marker to predict chemosensitivity to the drug. The aim of the present study was to evaluate whether the expression levels of adenosine triphosphate-binding cassette sub-family G (WHITE) member 2 (Junior blood group) (ABCG2) in primary colorectal tumors predict chemoresistance to irinotecan. Using the resected primary tumor specimens of 189 patients with colorectal cancer, the association between the immunohistochemical expression of ABCG2 protein and the results of the collagen gel droplet embedded culture drug sensitivity test, performed to evaluate the chemosensitivity to SN-38 (an active metabolite of irinotecan), was investigated. Among the 189 patients, 17 received irinotecan-based chemotherapy, and their responses and progression-free survival (PFS) were analyzed. The tumors of patients with increased ABCG2 expression accounted for 60% of the tumors examined, and were significantly more resistant to SN-38, compared with patients with low ABCG2 expression (P<0.001). In a multivariate logistic regression analysis, increased expression of ABCG2 protein was an independent and significant predictor of resistance to SN-38, increasing the risk of resistance by 12-fold. Increased expression of ABCG2 and a low sensitivity to SN-38 was significantly associated with resistance to irinotecan-based chemotherapy (P=0.01 and 0.028, respectively). The median PFS of patients with increased expression of ABCG2 was significantly shorter, compared with patients with low expression levels of ABCG2 (104 vs. 242 days; P=0.047). The increased immunohistochemical expression of ABCG2 in primary tumors may be a useful predictive biomarker of resistance to irinotecan-based chemotherapy for patients with recurrent or metastatic colorectal cancer.

A specific Streptococcus mutans strain aggravates non-alcoholic fatty liver disease

OBJECTIVE

Streptococcus mutans, a major dental caries pathogen, has shown to be associated with the aggravation of cerebral hemorrhage and inflammatory bowel diseases. In this study, we evaluated the effects ofS. mutans on the development of non-alcoholic steatohepatitis (NASH) in a mouse model.

MATERIALS AND METHODS

Streptococcus mutans oral strain MT8148 (serotype c) and a blood isolate TW871 (k) were used. C57BL/6J mice (6 weeks old)were fed a high-fat diet for 4 weeks; the test strains or phosphate-buffered saline was then intravenously administered. Mice were euthanized after 8 or 12 weeks. Whole body, extirpated liver, and visceral fat weights were determined, and histopathological evaluations of the liver specimens were performed.

RESULTS

Mice infected with TW871 showed significantly greater body and liver weights than those administered MT8148 or phosphate-buffered saline. Histopathological analyses revealed prominent infiltration of inflammatory cells and adipocellular deposition in livers extirpated 8 weeks after an infection with TW871; fibrosis was also observed in livers extirpated after 12 weeks.

CONCLUSION

These results suggest that a specific strain of S. mutans could induce NASH.

Thermal tissue change induced by a microwave surgical instrument in a rat hepatectomy model

BACKGROUND

Microwaves exhibit great potential in tissue heating, which causes effective coagulation. Using this energy, we have developed the microwave coagulation surgical instrument (MWCX) for clinical application. Here, we characterized the impact of MWCX on tissues including heating property, tissue change, and spread of thermal injury.

METHODS

Hepatectomy was performed with MWCX using a rat model. The resections were completed using various energy levels and powers. Tissue temperature during radiation was recorded. Tissue change and lateral thermal injury (LTI) was assessed immediately, 7 days, 3 months, and 6 months after resection.

RESULTS

All cutting and hemostasis procedures were successfully accomplished. Major histologic findings consisted of deformation or destruction of hepatocytes, tissue edema, and peripheral hemorrhage. At various energy levels, 200 to 1000 J, the tissue was heated up to approximately 80°C to 140°C causing 2.7- to 6.5-mm LTI on the 7th day. LTI was then decreased gradually in the following term. At certain energy levels, the application of neither 20 W nor 40 W induced significant difference in both heating and LTI.

CONCLUSIONS

MWCX achieved effective tissue coagulation with relevant tissue injury, and it should be a good candidate for clinical application.

MRI-detectable polymeric micelles incorporating platinum anticancer drugs enhance survival in an advanced hepatocellular carcinoma model

Hepatocellular carcinoma (HCC) is one of the most intractable and lethal cancers; most cases are diagnosed at advanced stages with underlying liver dysfunction and are frequently resistant to conventional chemotherapy and radiotherapy. The development of tumor-targeting systems may improve treatment outcomes. Nanomedicine platforms are of particular interest for enhancing chemotherapeutic efficiency, and they include polymeric micelles, which enable targeting of multiple drugs to solid tumors, including imaging and therapeutic agents. This allows concurrent diagnosis, targeting strategy validation, and efficacy assessment. We used polymeric micelles containing the T1-weighted magnetic resonance imaging contrast agent gadolinium-diethylenetriaminpentaacetic acid (Gd-DTPA) and the parent complex of the anticancer drug oxaliplatin [(1,2-diaminocyclohexane)platinum(II) (DACHPt)] for simultaneous imaging and therapy in an orthotopic rat model of HCC. The Gd-DTPA/DACHPt-loaded micelles were injected into the hepatic artery, and magnetic resonance imaging performance and antitumor activity against HCC, as well as adverse drug reactions were assessed. After a single administration, the micelles achieved strong and specific tumor contrast enhancement, induced high levels of tumor apoptosis, and significantly suppressed tumor size and growth. Moreover, the micelles did not induce severe adverse reactions and significantly improved survival outcomes in comparison to oxaliplatin or saline controls. Our results suggest that Gd-DTPA/DACHPt-loaded micelles are a promising approach for effective diagnosis and treatment of advanced HCC.

Resectable carcinoma developing in the remnant pancreas 7 years and 10 months after distal pancreatectomy for invasive ductal carcinoma of the pancreas: report of a case

BACKGROUND

Pancreatic ductal adenocarcinoma, which represents 90% of pancreatic cancers, is one of the most lethal and aggressive malignancies. Operative resection remains the only treatment providing prolonged survival, however, recurrence of pancreatic ductal adenocarcinoma occurs in up to 80% of patients with pancreatic cancer within 2 years of a potential curative resection. There are few reports of pancreatic carcinoma recurrence (primary second cancer) in the remnant pancreas after pancreatectomy.

CASE PRESENTATION

A 52-year-old woman underwent a distal pancreatectomy for pancreatic cancer in September 2004. Adjuvant chemotherapy was started after surgery and continued for 4 years. In March 2012, marked elevation of DUPAN-II was observed, followed by an irregular stenotic finding in the main duct. We performed an en bloc resection of the remnant pancreas in July 2012. Histologically, the tumor contained a second primary pancreatic carcinoma with lymph node metastasis. At follow-up 20 months after the second operation, the patient was alive without recurrence. Fourteen cases of resectable cancer developing in the remnant pancreas after a pancreatectomy for cancer have been reported; a minority of these was identified as second primary tumors. Therefore, our patient's primary second cancer is a rare event.

CONCLUSION

The patient is considered to have shown a rare, unique pancreatic cancer recurrence. Persistent elevation of a tumor marker and extensive imaging led to proper diagnosis and treatment.

Magnetic resonance imaging shrinkage patterns following neoadjuvant chemotherapy for breast carcinomas with an emphasis on the radiopathological correlations

Preoperative neoadjuvant chemotherapy (NAC) is considered to be the standard treatment for locally-advanced breast carcinomas. Obtaining precise information regarding the tumor extent and distribution by imaging modalities to assess the success of breast-conserving surgery following NAC is extremely important. Analysis of the detailed radiopathological correlation of magnetic resonance imaging (MRI) following NAC has not been reported previously. The MRI and histopathological shrinkage patterns of residual breast carcinomas in 27 consecutive cases were analyzed following NAC and classified into five categories: Types I and II (concentric shrinkage with and without surrounding lesions, respectively); type III (shrinkage with residual multinodular lesions); type IV (diffuse contrast enhancement in whole quadrant); and non-visualization. The present study clearly demonstrated that the most common MRI shrinkage pattern was type I (11 cases), followed by type II and non-visualization, and the most common histopathological shrinkage pattern was type II (11 cases), followed by type III (8 cases). The concordance rate between MRI and pathological patterns was 48% and the worst concordance MRI pattern was type I. MRI is considered to be a useful method for evaluation of the residual carcinoma following NAC. However, the concordance rate was low in the MRI pattern I cases and tiny foci of residual carcinoma were present in half of the non-visualization cases, as shown by MRI. Therefore, the tumor extent must be completely resected for patients who undergo NAC, and postoperative radiation may be important for preventing local recurrence of breast carcinoma.

Surgery-induced peritoneal cancer cells in patients who have undergone curative gastrectomy for gastric cancer

BACKGROUND

Some patients who undergo curative gastrectomy with lymph node dissection (LND) for gastric cancer (GC) show subsequent peritoneal metastasis. The source of these metastatic cells remains unclear.

METHODS

Curative gastrectomy with LND was performed in 102 patients with GC. Peritoneal washing was collected before and after gastrectomy. Cytology, reverse transcription-polymerase chain reaction, and cell culture were used to determine the presence of cancer cells. The proliferative potential of tumor cells was evaluated using Ki-67 staining. Tumorigenic capacity was assessed by cell injection into the peritoneal cavity of NOD/ShiJic-scid mice. Peritoneal recurrence-free survival (RFS) and peritoneal recurrence rate (RR) were examined to determine the clinical relevance of detected cancer cells.

RESULTS

Of 102 peritoneal washing samples obtained before gastrectomy, 57 showed no CEA or CK20 mRNA amplification. After gastrectomy, CEA or CK20 mRNA was detected in 35 of these 57 samples, and viable cancer cells were identified in 24. The viable cancer cells in all 24 cases showed Ki-67 positivity, indicating proliferative activity. Cultured viable cancer cells generated peritoneal nodules after spilling over the peritoneal cavity in NOD/ShiJic-scid mice in 4 cases. The peritoneal RFS of patients with CEA or CK20 mRNA amplification after gastrectomy was significantly poorer than that of patients with negative amplification (p < .05). The 24 patients with viable cancer cells in the peritoneal cavity after gastrectomy showed higher peritoneal RR than those without them (p = .033).

CONCLUSIONS

Viable tumorigenic cancer cells spilled into the peritoneal cavity during surgery, indicating that surgery induces peritoneal metastasis.

Hyperthermic intraperitoneal chemotherapy using a combination of mitomycin C,5-fluorouracil, and oxaliplatin in patients at high risk of colorectal peritoneal metastasis: A Phase I clinical study

INTRODUCTION

The drugs and protocols used for hyperthermic intraperitoneal chemotherapy (HIPEC) vary among institutions. Here we show the efficacy of the 3-drug combination of mitomycin C (MMC), 5-fluorouracil (5FU), and oxaliplatin (OHP) in an in vitro simulation of HIPEC and the safety of HIPEC with these drugs during a Phase I study of patients at high risk of developing colorectal peritoneal metastasis.

METHODS

To simulate HIPEC, we used HCT116 and WiDr cells to assess the growth inhibitory efficacy of MMC 2 μg/mL, 5FU 200 μg/mL, and OHP 40 μg/mL as single drugs or their combination after an exposure time of 30 min at 37 or 42 °C. In addition, nine patients underwent surgical resection of tumors and HIPEC with MMC, 5FU, and an escalating dose of OHP (90/110/130 mg/m²). Dose-limiting toxicity was monitored.

RESULTS

In the simulation, the 3-drug combination showed marked tumor-suppressive effects compared with those from ten times higher dose of OHP 400 μg/mL, with significant augmentation under hyperthermic conditions. No dose-limiting toxicity occurred in the clinical study. Dose escalation was completed at the final level of OHP.

CONCLUSIONS

The MMC-5FU-OHP combination showed marked growth inhibition against colorectal cancer cells under hyperthermic conditions in vitro. In the phase I study, the recommended dose of OHP was determined as 130 mg/m² when used with MMC and 5FU; HIPEC using MMC-5FU-OHP appears to be safe and feasible for patients at high risk of colorectal peritoneal metastasis.

Cetuximab as salvage monotherapy in chemotherapy-refractory metastatic colorectal cancer: A single-center report

In July 2008, cetuximab, a monoclonal antibody against epidermal growth factor receptor (EGFR), was approved in Japan for clinical use against chemotherapy-refractory metastatic colorectal cancer (mCRC). At Shiga University of Medical Science, between December 2007 and April 2012, a total of 24 EGFR-positive mCRC cases were administered immunohistochemistry with cetuximab as salvage monotherapy. The safety, side-effects and clinical efficacy of the treatment, including response rate, time to treatment failure, progression-free and overall survival, K-ras mutation status and impact on outcome, were investigated. The patient tumor growth control rate (TCR) was 38%, the mean time to progression (TTP) was 9.8 weeks [95% confidence interval (CI), 7.2-12.4] and the mean overall survival (OS) was 49.4 weeks (95% CI, 30.1-68.8). The most common adverse reactions reported were skin reactions, including acne (67%), hand-foot syndrome (16.7%) and paronychia (16.7%), followed by hypocalcemia (50%), hypomagnesemia (16%), stomatitis (20%) and gastrointestinal disorders (12%). The results of the present single-center study demonstrated that cetuximab monotherapy is beneficial for the treatment of chemotherapy-refractory patients with mCRC and that it has an acceptable level of safety and manageable side-effects.

Transmembrane mucin MUC1 overexpression and its association with CD10⁺ myeloid cells, transforming growth factor-β1 expression, and tumor budding grade in colorectal cancer

The prognostic value of mucin expression has been reported in several studies. We examined the association between mucin expression and other previously reported prognostic factors, including infiltration of CD10⁺ myeloid cells, transforming growth factor-β1 (TGF-β1) expression, and tumor budding at invasion fronts. Immunohistochemical analysis of 206 colorectal samples was carried out to determine whether MUC1, MUC2, MUC4, and MUC5AC expression could predict the survival of colorectal cancer patients. Serial sections were stained for CD10, TGF-β1, and pan-cytokeratin in order to detect tumor budding. As per multivariate analyses, MUC1 expression appeared to be the most significant predictor of both recurrence-free survival and overall survival. MUC4 was only significant to predict recurrence-free survival, and MUC5AC could be a good marker in stage IV colorectal cancers that require additional chemotherapy. MUC1 (CD227) expression was associated with infiltration of CD10⁺ myeloid cells, TGF-β1 expression, and tumor budding grade. These findings suggest that MUC1 is indicative of poor prognoses that may be associated with immunosuppression and epithelial-mesenchymal transition. Furthermore, MUC1 expression appears to be a chemoattractant for CD10⁺ stromal cells.

Surgery-induced peritoneal metastasis and its intraoperative treatment

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Background: A large number of advanced gastric cancer patients undergoing curative gastrectomy with D2 lymph node dissection (D2 gastrectomy) show peritoneal metastasis. The source of these metastatic cells and their treatment remain unclear. We examined the mechanism of surgery-induced peritoneal metastasis and determined the appropriate intraoperative treatment. Methods: (1) Curative gastrectomy was performed for 102 gastric cancer patients. Peritoneal lavage fluid was collected before and after gastrectomy. Cytology, RT-PCR, and cell culture were used to determine the presence of cancer cells. Proliferative potential of tumor cells was evaluated using Ki-67 staining. Tumorigenic capacity was assessed by cell injection into the peritoneal cavity of NOD/ShiJic-scid mice. (2) Fifty clinical T3(SE) or T4(SI) advanced gastric cancer patients undergoing curative D2 gastrectomy prospectively received intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC) in a phase II trial. HIPEC comprised 50 mg CDDP, 10 mg MMC, and 1000 mg 5-FU in 5 L saline maintained at 42–43C° for 30 min. Results: (1) Of 102 peritoneal lavage fluid samples obtained before gastrectomy, 57 from both early and advanced cancer patients did not contain CEA or CK20 mRNA amplification products or cancer cells. Of these 57 samples, CEA or CK20 mRNA was detected in 35 and viable cancer cells were identified in 24 after gastrectomy. Viable cancer cells in all 24 cases showed Ki-67 positivity, indicating proliferative activity. Cultured viable cancer cells developed into peritoneal tumor nodules after spill over into the peritoneal cavity in NOD/ShiJic-scid mice. (2) Fifty patients were eligible for the phase II clinical trial. The overall 5-year survival rate for all patients was 92.4%. This rate in patients with pT2(ss) (n = 12), pT3(se) (n = 35), and pT4(si) (n = 3) disease was 90.0%, 92.3%, and 100%, respectively. Only 2 patients (4%) showed peritoneal relapse. Conclusions: Viable tumorigenic cancer cells spilled over the peritoneal cavity during curative gastrectomy. Intraoperative HIPEC following curative D2 gastrectomy effectively prevented peritoneal metastasis, thereby potentially improving the prognosis of patients with advanced gastric cancer.

Prospective, randomized trial comparing harmonic scalpel and electrocautery in breast surgery

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Background: The objective of this study was to compare the potential advantages of the harmonic scalpel with those of electrocautery for axillary lymph node dissection in breast surgery. Methods: A prospective randomized study of axillary lymph node dissection procedures performed between March 2011 and September 2012 was conducted. Primary breast cancer patients with axillary node-positive status (n = 25) were randomly assigned to the harmonic scalpel (group A, n = 13) or electrocautery (group B, n = 12) groups.The patients underwent breast-conservation surgery or mastectomy with a level I and II axillary dissection, which was performed by one surgeon. The time required for resection and the blood loss during the lymphadenectomy were recorded. The HARMONIC FOCUS (Ethicon Endo-Surgery, Inc.) was used as the ultrasonic scalpel. A low-pressure vacuum drain was placed in the axilla and removed when the drainage volume reduced to less than 50 ml over 24 hours. After the operations, the patients were assessed for the presence of seroma in an outpatient setting. Results: Resection timein group A was significantly shorter than that in group B (mean, 28.6 ± 5.1 vs. 40.3 ± 5.6 min; P = 0.0001). Similarly, blood loss in group A was significantly lower than that in group B (mean, 7.9 ± 5.3 vs. 22.9 ± 11.5 ml; P = 0.001). Duration of drain placement in group A was significantly lower than that in group B (mean, 3.5 ± 1.1 vs. 5.0 ± 0.9 days; P = 0.01), and the seroma rate in group A was lower than that in group B (23% vs. 66%; P = 0.04). Conclusions: For axillary lymph node dissection, the harmonic scalpel is more effective in terms of resection time, blood loss, duration of drain placement, and postoperative seroma formation.

Aggravation of inflammatory bowel diseases by oral streptococci

OBJECTIVES

Streptococcus mutans can aggravate colitis in mice. We evaluated the virulence of colitis using type strains as well as blood isolates of several oral streptococcal species.

MATERIALS AND METHODS

We investigated the susceptibility of blood isolates of several oral streptococci to phagocytosis, adhesion to and invasion of hepatic cells and interferon-γ secretion. A mouse model of dextran sodium sulphate-induced colitis was used to evaluate bacterial aggravation of colitis. In addition, interferon-γ antibody was administered to mice with prominent aggravation of colitis.

RESULTS

In vitro analyses showed that Streptococcus sanguinis ATCC 10556 was a possible virulent strain among type strains of several oral streptococci, and that analysis of blood isolates of S. sanguinis TW289 revealed a potential virulent strain. Intravenous administration of ATCC 10556 and TW289 caused prominent aggravation of dextran sodium sulphate-induced colitis, and histopathological examinations showed that interferon-γ secretion due to infection of hepatic cells caused colitis aggravation. Administration of interferon-γ antibody suppressed TW289-induced colitis.

CONCLUSION

These results suggest that some virulent oral streptococcal strains are associated with the aggravation of colitis induced by enhanced secretion of interferon-γ when they invade the bloodstream.

Prognostic impact of CD10 expression in clinical outcome of invasive breast carcinoma

BACKGROUND

Early diagnosis and treatment for breast cancers has greatly improved in recent years, however, subset of this disease with early recurrence have remained to be unpredictable. Several studies has addressed that strong CD10 expression in tumor stroma is associated with poor survival rate of breast cancers, but no correlation between CD10 expression and disease-free survival has been elucidated yet. For these reasons, this study with modified immunohistochemical (IHC) staining evaluated the expression of CD10 in invasive breast carcinomas (IBCs) and analyzed correlations between CD10 expression on tumor cells, stromal cells and myeloid-like cells with clinicopathological parameters and recurrence status.

METHOD

IHC staining method was performed on formalin-fixed paraffin-embedded sections of 73 cases of primary IBCs, with record of pathological characteristics of subjects followed up from 1998 to 2007.

RESULTS

Stromal CD10 expression was observed in 39/73 cases (53.4 %) with strong expression in 41.0 %. Three cases stained positive for myeloid-like cells and five for carcinomatous cells, of which 6 cases had recurrence and/or regional LN status. Stromal CD10 expression was significantly higher in the unfavorable group (69.6 %; 16/23 cases) compared with the favorable group (32.1 %; 9/28 cases) (p = 0.048). The levels of CD10 expression showed significant difference among clinical outcomes (recurrence or non-recurrence), independent of regional LN status (p = 0.034), histology type (p = 0.044), ER status (p = 0.042), PgR status (p = 0.039), Her2 status (p = 0.038) and Ki67 index (p = 0.036) (partial Pearson correlations). Cox proportional-hazards regression showed that risk factors for disease-free survival were stromal CD10 expression [CD10±, CD10+ versus CD10++; p = 0.003; HR 2.824 (1.427-5.591)]; regional LN status [N0, N1, N2, versus N3; p = 0.004; HR 2.107 (1.262-3.517)] and PgR status [negative versus positive, p = 0.006, HR 0.172 (0.049-0.596)].

CONCLUSION

CD10 expression on stroma with or without other positive tumor cells and/or myeloid-like cells may function as a powerful prognostic factor for IBC disease-free survival rates, predicting of potential recurrence. It can be determined by a simple modified IHC staining method, which is independent of other prognostic morphologic markers and biomarkers in IBC.

Leiomyoma of the gallbladder in a patient with metastatic gastrointestinal stromal tumor in the liver: A case report with differential diagnostic considerations

Mesenchymal tumor of the gallbladder is rare and the majority of cases present as sarcomas. Benign mesenchymal tumors of the gallbladder are extremely rare and to date, only one case of leiomyoma has been reported. In this report, we describe a second case of leiomyoma of the gallbladder, and discuss the differential diagnostic considerations. A 55-year-old female with metastatic gastrointestinal stromal tumors (GISTs) in the liver was identified to possess a tumorous lesion of the gallbladder. The patient had previously received a partial gastrectomy for GIST, and multiple liver metastases were revealed. Following surgery, imatinib was administered, and the liver metastatic lesions were stabilized. Histopathological analysis of the resected gallbladder specimens revealed that the nodule arose from the muscular layer, and was composed of spindle cell proliferation with eosinophilic cytoplasm and bland cigar-shaped nuclei. Mitotic figures were rarely noted, and necrosis was not observed. Immunohistochemical analyses demonstrated that the tumor cells were positive for desmin and alpha-smooth muscle actin, but negative for CD117 and CD34. In accordance with these results, a final diagnosis of leiomyoma of the gallbladder was made. The present case is unique since the patient possessed multiple metastatic GISTs in the liver, and the gallbladder nodule was preoperatively suspected to be a metastatic GIST. Leiomyoma of the gallbladder is extremely rare; however, it may be an underrecognized entity. Thus, it is important to differentiate leiomyoma from GIST to avoid unnecessary clinical follow-up and treatment.

Concomitant intraductal papillary mucinous neoplasm and neuroendocrine tumor of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) and neuroendocrine tumor (NET) of the pancreas are rare tumors and their association is not expected to be frequent. However, certain studies have suggested that the concomitant occurence of these tumors may be more frequent than previously thought. In the current study, we describe a case of concomitant occurrence of IPMN and NET of the pancreas and review the clinicopathological features of previously published cases and the current one. A 68-year-old female was incidentally found to have dilatation of the main pancreatic duct. A distal pancreatectomy was performed under the clinical diagnosis of IPMN. Histopathological analysis revealed concomitant IPMN (low-grade) and NET G1 of the pancreas. Review of the clinicopathological features of the 15 previously reported cases of concomitant IPMN and NET of the pancreas as well as the present one indicated that: i) this condition mainly affects middle-aged females; ii) the main symptom is abdominal or back pain, or no symptoms; iii) a hormone production symptom was observed in only one case; iv) the most common degree of dysplasia of IPMN is low grade; and v) the size of the NET is not particularly large (average 15.1 mm), although the clinical behavior is not always indolent (metastasis was observed in 3 cases). It is well known that IPMNs are associated with a high incidence of extrapancreatic malignancies, including colorectal and gastric carcinomas. Concomitant pancreatic NET and extrapancreatic malignancies may occur, therefore, systemic surveillance of extrapancreatic neoplasms and detection of concomitant NETs of the pancreas are necessary for patients with IPMN.

Potential involvement of collagen-binding proteins of Streptococcus mutans in infective endocarditis

OBJECTIVE

Streptococcus mutans, a major pathogen of dental caries, is considered to be one of the causative agents of infective endocarditis (IE). Two types of cell surface collagen-binding proteins, Cnm and Cbm, have been identified in the organism. The aim of the present study was to analyze these proteins as possible etiologic factors for IE.

MATERIALS AND METHODS

The binding activities of S. mutans strains to collagen types I, III, and IV were analyzed relative to the presence of Cnm and Cbm, as were their adhesion and invasion properties with human umbilical vein endothelial cells (HUVEC). In addition, distributions of the genes encoding Cnm and Cbm in S. mutans-positive heart valve specimens extirpated from IE and non-IE patients were analyzed by PCR.

RESULTS

Most of the Cbm-positive strains showed higher levels of binding to type I collagen as well as higher rates of adhesion and invasion with HUVEC as compared to the Cnm-positive strains. Furthermore, the gene encoding Cbm was detected significantly more frequently in heart valve specimens from IE patients than from non-IE patients.

CONCLUSIONS

These results suggest that the collagen-binding protein Cbm of S. mutans may be one of the potential important factor associated with the pathogenesis of IE.

Clear cell neuroendocrine tumor G1 of the gallbladder without von Hippel-Lindau disease

Clear cell neuroendocrine tumor (NET) is a rare but distinct histopathological variant of NET most often observed in patients with von Hippel-Lindau disease (VHL). Clear cell NET in non-VHL patients is extremely rare and this report is only the second to describe a case of clear cell NET G1 (carcinoid tumor) of the gallbladder without VHL. A 71-year-old male without past or family history of VHL presented with a polypoid lesion in the fundus of the gallbladder and laparoscopic cholecystectomy was performed. Histopathological study revealed that the polypoid lesion was comprised of nests or trabecular growths of clear cells without atypia. Immunohistochemically, the neoplastic cells were diffusely positive for endocrine markers, but negative for α-inhibin. Clinicopathological review of cases with clear cell NET G1 of the gallbladder revealed that this disease occurs in patients with or without VHL, but that gallbladder stones and cholecystitis were present in non-VHL cases. We hypothesized that the occurrence of clear cell NET of the gallbladder (particularly non-VHL cases) may be associated with chronic cholecystitis induced by gallbladder stones. Moreover, α-inhibin was detected in clear cell NET tumor cells in one VHL case, but not in two non-VHL cases. These findings suggest that α-inhibin expression is a useful determinant of an association between clear cell NET and VHL.

Distribution of periodontopathic bacterial species in dogs and their owners

OBJECTIVE

Presently, a large number of individuals consider their companion animals as family members and have close contact with them in daily life. The purpose of the present study was to analyze the distribution of periodontopathic bacterial species in oral specimens taken from dogs and their owners.

DESIGN

Dental plaque specimens were collected from 66 dogs and 81 members of 64 families who came to an animal clinic or dog training school in Okayama, Japan, in 2011. Bacterial DNA was extracted from each specimen and PCR analyses using primers specific for 11 periodontopathic species, Porphyromonas gingivalis, Porphyromonas gulae, Treponema denticola, Tannerella forsythia, Capnocytophaga ochracea, Capnocytophaga sputigena, Prevotella intermedia, Prevotella nigrescens, Aggregatibacter actinomycetemcomitans, Campylobacter rectus, and Eikenella corrodens were performed.

RESULTS

P. gulae (71.2%), T. forsythia (77.3%), and C. rectus (66.7%) were frequently found in the dogs, whereas the detection rates of those species in humans were less frequent at 16.0%, 30.9%, and 21.0%, respectively. P. gulae was identified in 13 human subjects and each of their dogs was also positive for the species. Furthermore, E. corrodens and T. denticola in specimens obtained from dogs were correlated with their presence in specimens from owners who had close contact with them.

CONCLUSIONS

These results suggest that several periodontopathic species could be transmitted between humans and their companion dogs, though the distribution of periodontopathic species in both is generally different.

Hyperthermic intraperitoneal chemotherapy following gastrectomy for the prevention of carcinomatosis in advanced gastric cancer: Nonrandomized phase II prospective trial

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Background: About half of patients with serosa-invasive gastric cancer develop peritoneal recurrence and die of this disease even if curative resections performed. This prospective phase II study was performed to assess the efficacy and safety of hyperthermic intraperitoneal chemotherapy (HIPEC) with three anticancer drugs in patients with curative resection of clinically T3 or T4 serosa-invasive advanced gastric cancer.

Methods: Patients age 75 years or younger with curative resection of clinically T3 or T4 advanced gastric cancer were eligible for this nonrandomized phase II trial. After the curative resection of gastric cancer with D2 lymph node dissection, HIPEC was carried out for 30 minutes with 50mg of CDDP, 10mg of MMC, and 1000mg of 5-FU in 5 L saline maintained at 42-43C°. Patients were given an adjuvant S-1 treatment after surgery. Primary endpoint of this study was overall survival. Second end points included safety and recurrence rate.

Results: A total of 50 patients were eligible between January 2002 and December 2010. Pathologically, 12 patients had sub-serosal invasion (pT2(ss)), 35 patients had serosal invasion (pT3), and 3 patients had adjacent organ invasion (pT4). Median follow-up period was 52 months (12-104 months). Overall 5-year survival rate in all eligible patients was 89.9%. Overall 5-year survival rate in patients with stage IB (n=4), stage II (n=12), stage IIIA (n=18), or stage IIIB (n=16) was 100%, 100%, 90.9%, or 76.2%, respectively. Only one patient (2.0%) had peritoneal recurrences. Four patients (8.0%) with pN2 had lymphatic recurrences. A total of 13 patients had postoperative complications such as minor pancreatic fistula (Grade A) (10.0%), abdominal abscess (4.0%), leakage of the anastomosis (8.0%), and pneumonia (6.0%). All patients recovered without any surgical interventions. None of patients needed for the treatment in the Intensive Care Units after HIPEC.

Conclusions: Intra-operative HIPEC with three anticancer drugs following curative resection of advanced gastric cancer improves overall survival with an inhibition of peritoneal recurrence and an acceptable morbidity.

Clinical trial of cisplatin-conjugated gelatin microspheres for patients with hepatocellular carcinoma

PURPOSE

We report our initial experience with the transarterial chemoembolization (TACE) of unresectable hepatocellular carcinoma (HCC) using cisplatin-conjugated gelatin microspheres (Cis-GMS).

METHODS AND MATERIAL

Nineteen patients with 25 HCC nodules (mean diameter 23.0 mm) were treated by selective TACE using 50- to 100-μm Cis-GMS. Tumor necrosis and postembolization syndrome were assessed during the follow-up. The tumor response was evaluated on contrast-enhanced computed tomography images at 1 and 3 months after TACE using Cis-GMS.

RESULTS

All procedures were technically successful in all patients; following the TACE using Cis-GMS, there were no major complications, and postembolization syndrome was minimal. At the 1-month follow-up, the response rate was 12 of the 25 (48%) and 21 of the 25 (84%) HCC nodules based on RECIST 1.1 and EASL criteria, respectively; at the 3-month follow-up, it was 10 of the 25 (40%) and 14 of the 25 (56%) HCC nodules, respectively.

CONCLUSION

Our initial experience with using Cis-GMS for TACE suggests that these drugs may represent an optimal treatment option for the treatment of advanced HCC and that the use of gelatin microspheres loaded with chemotherapeutic agents warrants further study.

Non-Epstein-Barr virus associated lymphoepithelioma-like carcinoma of the inferior common bile duct

A carcinoma displaying undifferentiated features with dense lymphoplasmacytic infiltration is defined as a lymphoepithelioma-like carcinoma (LEC), and some of LEC is associated with Epstein-Barr virus (EBV). All of the 13 previously reported cases of LEC of the biliary system were intrahepatic in location. Herein, we describe the first case of LEC of the inferior common bile duct. A 68-year-old Japanese man, who had been previously treated for hepatocellular carcinoma using microwave coagulation therapy, was found to have tumors of the common bile duct and pancreas head. Histopathological study of the resected tumor showed solid or cohesive nests of large undifferentiated cells with irregular large vesicular nuclei and nucleoli. Around the tumor cell nests, dense lymphoplasmacytic infiltration was observed. Focal glandular differentiation (approximately 5%) was also present. These histopathological features corresponded morphologically to LEC. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) 7, CK 19 and CA19-9, but negative for CK 20 and Hep Par 1. In situ hybridization for Epstein Barr virus early small RNAs disclosed no nuclear signal in tumor cells. Therefore, a diagnosis of non-EBV-associated LEC of the inferior common bile duct was made. Although the prognosis of the biliary LEC is thought to be better than that of conventional cholangiocarcinoma, the differences in prognosis between EBV-positive and -negative cases have not yet been established. Therefore, additional case studies will be needed to clarify the clinicopathological features of LEC of the biliary tract.