Development of a unilateral porcine emphysema model induced by porcine pancreatic elastase.

Emphysema is one of the pathological hallmarks of chronic obstructive pulmonary disease. We have recently reported that radiofrequency therapy improves lung function in rodent models of emphysema. However, preclinical data using large animals is necessary for clinical translation. Here, we describe the work performed to establish a unilateral porcine emphysema model. Different doses of porcine pancreatic elastase (PPE) were instilled into the left lung of 10 Yucatan pigs. Three additional pigs were used as controls. Six weeks after instillation, lungs were harvested. Lung compliance was measured by a water displacement method and plethysmography. Systematic uniform random sampling of the left and right lungs was performed independently to measure alveolar surface area using micro-computed tomography (micro-CT) and histology. In pigs instilled with 725-750 U/kg of PPE (PPE group, n = 6), the compliance of the left lung was significantly higher by 37.6% than that of the right lung (P = 0.03) using the water displacement method. With plethysmography, the volume of the left lung was significantly larger than that of the right lung at 3, 5, and 10 cmH2O. Measurements from either micro-CT or histology images showed a significant decrease in alveolar surface area by 14.2% or 14.5% (P = 0.031) in the left lung compared with the right lung of the PPE group. A unilateral model for mild emphysema in Yucatan pigs has been established, which can now be used for evaluating novel therapeutics and interventional strategies.NEW & NOTEWORTHY For clinical translation, preclinical data using large animal models is necessary. However, papers describing an emphysema model in pigs, which are anatomically and physiologically similar to humans, are lacking. Here, we report success in creating a unilateral mild-emphysema model in pigs with only one single dose of porcine pancreatic elastase. This model will be useful in bringing novel technologies and therapies from small animals to humans with emphysema.

Impact of D2 Gastrectomy for Locally Advanced Gastric Cancer in the Era of Effective Adjuvant Chemotherapy.

BACKGROUND: Gastrectomy with D2 dissection has been established as the standard procedure for locally advanced gastric cancer in the era of surgery alone. However, no consideration has been given to the efficacy of dissection in the era of effective adjuvant chemotherapy. METHODS: This study included 1298 advanced gastric cancer patients, consisting of 725 cases treated between January 2000 and December 2006 (Former group), and 573 cases treated between January 2007 and July 2015 (Latter group). Clinicopathological data were collected, survival and the therapeutic value index were determined. RESULTS: The background characteristics were well balanced, except for age, tumor location, and intraoperative blood loss. The Latter group showed the following characteristics: an older population (p < 0.001), a frequent upper location (p = 0.008), and less blood loss (p < 0.001). Adjuvant chemotherapy was administered to 75.2% of the Latter group and was 9.4% in the Former group. The 5-year overall survival rate of the Latter group was 75.7% (95% confidence interval: 71.7-79.1), significantly better than that of the Former group (70.0%, 95% confidence interval: 66.5-73.2) (p = 0.025). Improvement in the index from the Former group was observed in the Latter group at almost all stations. The ratio of the index between these two groups was 1.09 at the D1 station and 1.19 at the D2 station. CONCLUSION: The therapeutic value index was improved in all nodal stations by S-1 adjuvant chemotherapy, regardless of whether the D1 or D2 nodes were involved. D2 gastrectomy would be still important for locally advanced gastric cancer in the era of effective adjuvant chemotherapy.

Role of phosphate transporter PiT-2 in the pathogenesis of primary brain calcification.

Primary brain calcification (PBC), also known as idiopathic basal ganglia calcification (IBGC), primary familial brain calcification (PFBC) and so on, is a rare intractable disease characterized by abnormal mineral deposits, including mostly calcium in the basal ganglia, thalamus, and cerebellum. The causative gene of familial PBC is SLC20A2, which encodes the phosphate transporter PiT-2. Despite this knowledge, the molecular mechanism underlying SLC20A2-associated PBC remains unclear. In the present study, we investigated whether haploinsufficiency or a dominant-negative mechanism reduced Pi uptake in two PiT-2 variants (T115 M and R467X). We demonstrated that the presence of T115 M or R467X had no dominant-negative effect on Pi transport activity of wild-type (WT). In addition, the subcellular localization of R467X completely differed from that of WT, indicating that there is no interaction between R467X and WT. Conversely, T115 M and WT showed almost the same localization. Therefore, we examined the interaction between T115 M and WT using the bioluminescence resonance energy transfer (BRET) method. Although WT and T115 M interact with each other, T115 M does not inhibit WT's Pi transport activity. These results suggest that the role of SLC20A2 in the pathogenesis of PBC may involve decreased intracellular Pi uptake by a haploinsufficiency mechanism rather than a dominant-negative mechanism; agents promoting PiT-2 dimerization may be promising potential therapeutic agents for PBC.

Suprapancreatic nodal dissection should not be uniformly selected in additional gastrectomy for the patients who diagnosed as pT1b gastric cancer by endoscopic resection.

BACKGROUND: Surgery for T1b gastric cancer requires suprapancreatic nodes (SPA nodes) and perigastric nodes (PG nodes), however, SPA nodal dissection can cause pancreatic complications. If endoscopic treatment followed by additional surgery is planned, it may be possible to predict SPA nodal metastasis by analyzing the pathological information of the primary tumor in addition to the clinical findings. METHODS: Patients who underwent D1+ or D2 and who were pathologically diagnosed with pT1b were retrospectively analyzed. The stations were divided into the nodes located at the perigastric area (PG nodes; #1-7) and the nodes located at the suprapancreatic area (SPA nodes; #8a-12a). The patients were classified into those with and without metastasis to the SPA nodes. Clinicopathological factors were investigated for their possible association with metastasis to the SPA nodes. RESULTS: A total of 2017 patients were examined in this study. Metastasis to the SPA nodes was observed in 80 patients (4%). In a multivariate analysis, undifferentiated histology, lower third, and lymphovascular invasion were independent risk factors for metastasis to the SPA nodes. The risk of metastasis to the SPA nodes was <2% in upper/middle tumors of differentiated type with no lymphovascular invasion and in lower tumors of undifferentiated type with no lymphovascular invasion. On the other hand, the risk of metastasis to the SPA nodes was >10% in lower tumors of undifferentiated type with lymphovascular invasion. CONCLUSION: SPA nodal metastasis can be predicted when endoscopic treatment is initially planned. SPA nodal dissection should not be uniformly selected for T1b gastric cancer.

Radiofrequency therapy improves exercise capacity of mice with emphysema.

Emphysema is a common phenotype of chronic obstructive pulmonary disease (COPD). Although resection of emphysematous tissue can improve lung mechanics, it is invasive and fraught with adverse effects. Meanwhile, radiofrequency (RF) treatment is an extracorporeal method that leads to tissue destruction and remodeling, resulting in "volume reduction" and overall improvement in lung compliance of emphysematous lungs. Whether these changes lead to improved exercise tolerance is unknown. Here, we investigated the effectiveness of RF treatment to improve the exercise capacity of mice with emphysema. Fifty-two mice (7 weeks of age) were used in this experiment. A bilateral emphysema model was created by intratracheally instilling porcine pancreatic elastase (PPE) (1.5U/100 g body weight). RF treatment (0.5 W/ g body weight) was administered extracorporeally 14 days later and mice were sacrificed after another 21 days. The exercise capacity of mice was measured using a treadmill. Treadmill runs were performed just before PPE instillation (baseline), before RF treatment and before sacrifice. Following sacrifice, lung compliance and mean linear intercept (Lm) were measured and fibrosis was assessed using a modified Ashcroft score. There were 3 experimental groups: controls (instilled with saline, n = 12), emphysema (instilled with porcine pancreatic elastase, PPE, n = 11) and emphysema + treatment (instilled with PPE and given RF, n = 9). At endpoint, the maximum velocity of the emphysema + treatment group was significantly higher than that of the emphysema group, indicating improved exercise tolerance (86.29% of baseline vs 61.69% of baseline, p = 0.01). Histological analysis revealed a significant reduction in emphysema as denoted by Lm between the two groups (median 29.60 µm vs 35.68 µm, p = 0.03). The emphysema + treatment group also demonstrated a higher prevalence of lung fibrosis (≧Grade 3) compared with the emphysema group (11.7% vs 5.4%, p < 0.01). No severe adverse events from RF were observed. RF treatment improved the exercise capacity of mice with emphysema. These data highlight the therapeutic potential of RF treatment in improving the functional status of patients with COPD.

Pulmonary Rehabilitation in a Post-COVID-19 World: Telerehabilitation as a New Standard in Patients with COPD.

Pulmonary rehabilitation (PR) is effective in reducing symptoms and improving health status, and exercise tolerance of patients with chronic obstructive pulmonary disease (COPD). The coronavirus disease 19 (COVID-19) pandemic has greatly impacted PR programs and their delivery to patients. Owing to fears of viral transmission and resultant outbreaks of COVID-19, institution-based PR programs have been forced to significantly reduce enrolment or in some cases completely shut down during the pandemic. As a majority of COPD patients are elderly and have multiple co-morbidities including cardiovascular disease and diabetes, they are notably susceptible to severe complications of COVID-19. As such, patients have been advised to stay at home and avoid social contact to the maximum extent possible. This has increased patients' vulnerability to physical deconditioning, depression, and social isolation. To address this major gap in care, some traditional hospital or clinic-centered PR programs have converted some or all of their learning contents to home-based telerehabilitation during the pandemic. There are, however, some significant barriers to this approach that have impeded its implementation in the community. These include variable access and use of technology (by patients), a lack of standardization of methods and tools for evaluation of the program, and inadequate training and resources for health professionals in optimally delivering telerehabilitation to patients. There is a pressing need for high-quality studies on these modalities of PR to enable the successful implementation of PR at home and via teleconferencing technologies. Here, we highlight the importance of telerehabilitation of patients with COPD in the post-COVID world and discuss various strategies for clinical implementation.

Laparoscopic para-aortic lymphadenectomy for colorectal cancer with clinically suspected lymph node metastasis.

INTRODUCTION: The optimal surgical management strategy for isolated para-aortic lymph node (PALN) metastases from colorectal cancer (CRC) remains unclear. However, the complication rates for open approaches remain high. In this study, the outcomes of laparoscopic para-aortic lymphadenectomy in patients with clinically suspected PALN metastasis were evaluated. METHODS: Between April 2013 and April 2018, we performed laparoscopic primary resection and para-aortic lymphadenectomy in 11 patients with advanced colorectal cancer and clinically suspected PALN metastasis. This study was a single-center, retrospective, case series analysis, and the surgical outcomes were reviewed. RESULTS: There were no cases of perioperative mortality, and conversion to open surgery was necessary in only one patient (9%) because of invasion into a rib. One patient (9%) required a blood transfusion. Postoperative complications occurred in three patients, and the morbidity rate was 27% (3/11). Pathologically, PALN metastasis was confirmed in five patients (45%), all of whom received postoperative chemotherapy. The median survival time for all patients was 25 months, and one patient died of recurrence at 25 months after the initial surgery. Two other patients were alive with recurrence after 47 and 36 months, and two patients were alive without recurrence after 17 and 2 months. CONCLUSION: Laparoscopic para-aortic lymphadenectomy for advanced colorectal cancer with clinically suspected PALN is technically feasible and may be beneficial in selected patients. It is necessary to investigate the feasibility of this procedure in a future case series, and information regarding true oncologic outcome will require long-term follow-up.

Long-term survival with extended lateral lymphadenectomy for lateral lymph node recurrence after laparoscopic abdominoperineal resection for rectal adenosquamous carcinoma: a case report.

The patient was a 54-year-old female who presented with the chief complaint of melena. Lower gastrointestinal endoscopy detected a type 1 tumor extending from the anal canal to the rectum. CT did not detect any distant metastasis. Proximal D3 lymphadenectomy with laparoscopic abdominoperineal resection was performed for stage IA rectal cancer. In the histopathological examination, the tumor was identified as stage IIIa adenosquamous carcinoma. Although the patient underwent postoperative adjuvant chemotherapy with S-1, a recurrent left lateral lymph node tumor was detected on CT and PET 12 months later. The patient underwent the treatment with mFOLFOX + bevacizumab for 6 months. However, the tumor continued to progress, and therefore, extended lateral lymphadenectomy was performed 21 months after the first surgery. The patient did not undergo postoperative adjuvant therapy and is alive without recurrence 90 months after the first surgery and 70 months after the reoperation. Adenosquamous carcinoma of the rectum is a rare histological type of colorectal cancer for which there is no effective treatment besides surgical resection, and its prognosis is known to be worse than that of adenocarcinoma. Since there has been no report of long-term survival after extended lateral lymphadenectomy for recurrent lateral lymph node tumors following surgery for adenosquamous carcinoma of the rectum, herein, we report the case with a review of the literature.

Erratum: Publisher Correction to: Severe adverse events due to dihydropyrimidine dehydrogenase deficiency in a Japanese patient with colon cancer taking capecitabine: a case report.

[This corrects the article DOI: 10.1007/s13691-018-0334-1.].

Severe adverse events due to dihydropyrimidine dehydrogenase deficiency in a Japanese patient with colon cancer taking capecitabine: a case report.

Fluoropyrimidine has been commonly used not only in unresectable cases of metastatic colorectal cancer, but also in adjuvant therapy. Dihydropyrimidine dehydrogenase (DPD) is an enzyme encoded by the DPYD gene, which is responsible for the rate-limiting step in pyrimidine catabolism and breaks down more than 80% of standard doses of 5-fluorouracil (5-FU) and capecitabine, an oral prodrug of 5-FU. The lack of enzymatic activity increases the half-life of the drug, resulting in excess drug accumulation and toxicity which may lead to life-threatening side effects. There have been several published case reports about DPD deficiency in patients with colorectal cancer in Western countries. However, case reports of DPD deficiency in Japanese patients with colorectal cancer are rare because measuring DPD activity is not covered by public medical insurance in Japan, and it is not examined in our daily clinical practice currently. Therefore, we think that it is important to accumulate such case reports for further understanding. This report describes the case of a Japanese patient with colon cancer who experienced severe side effects while taking capecitabine, due to DPD deficiency. A 68-year-old man with ascending colon cancer underwent curative laparoscopic right hemicolectomy. Because final pathologic staging was Stage IIIa, standard adjuvant chemotherapy with capecitabine (3600 mg/body/day, days 1-14, every 3 weeks) was started on postoperative day 50. After 2 weeks, he started to experience Grade 3 diarrhea and was admitted to the hospital on postoperative day 66. On day 70, the patient had Grade 4 febrile neutropenia. Antibiotics and granulocyte-colony-stimulating factor were administered until his blood tests recovered to the normal degree. After 1 week of diarrhea, antidiarrheal agents were administered, and the patient gradually recovered. During the occurrence of diarrhea, specimen cultures were negative for infection. He was discharged on day 21 of the hospital stay. DPD deficiency was suspected, and 2 weeks later the DPD activity of the peripheral blood mononucleocytes was examined. The result was 10.3 U/mg protein which was remarkedly low (reference range 22.6-183.6 U/mg protein), and DPD deficiency was diagnosed. We always must consider the possibility of DPD deficiency in patients who experience severe side effects while taking capecitabine.

Anastomotic Leakage Using Linear Stapling Device with Pre-attached Bioabsorbable Polyglycolic Acid Felt After Laparoscopic Anterior Resection.

AIM: Many studies have evaluated the risk factors for anastomotic leakage after laparoscopic anterior resection. In this study in order to increase the tightness of anastomoses and prevent bleeding from their staple lines, a linear stapler with pre-attached bioabsorbable polyglycolic acid (PGA) felt was used for rectal transection, and the short-term surgical outcomes were evaluated. PATIENTS AND METHODS: A prospective registry of 62 patients with rectosigmoidal or rectal carcinoma who initially underwent laparoscopic anterior resection using PGA felt for rectal transection was reviewed. RESULTS: The overall frequency of anastomotic leakage was 1.6% (1/62), and none of the patients developed postoperative staple line bleeding or other adverse events related to the use of PGA felt. CONCLUSION: The frequency of anastomotic leakage was relatively low, and therefore the use of a linear stapler with pre-attached bioabsorbable PGA felt might reduce the risk of adverse events related to anastomosis, especially anastomotic leakage.

Downregulation of cytochrome c oxidase 1 induced radioresistance in esophageal squamous cell carcinoma.

Comprehensive gene screening with transposons is a novel procedure for the systematic identification of resistant genes. The present study aimed to use this technique to identify candidate radioresistant genes in esophageal squamous cell carcinoma. A transposon is a base sequence that can translocate to another location in the genome at random. By inserting the cytomegalovirus promotor as a transcriptional activator in the transposon, the following gene in the new location becomes overexpressed and the gene located at the transposon insertion site is downregulated. Consequently, various transposon-tagged cells, which have differentially overexpressed or downregulated genes using the transposon method can be obtained. Following the irradiation of transposon-tagged cells, candidate radioresistant genes can be selected in order to detect the location of the transposon in the cells that have survived. A total of 11 genes were detected as candidate radioresistant genes. Cytochrome c oxidase 1 (MT-CO1), an enzyme involved in apoptosis through the activation of the caspase cascade, was one of the candidate genes identified. The relative expression level of MT-CO1 was 0.12 in MT-CO1-downregulated cells which was significantly lower compared with the expression level in parent TE4 cells (P<0.001). The survival rate was 28.7% in MT-CO1-downregulated cells and 10.5% in parent TE4 cells 9 days following 5-Gy irradiation. The activity of cytochrome c and caspase-3 following irradiation was significantly lower in the MT-CO1-downregulated radioresistant cells compared with in TE4 cells. In conclusion, the novel gene screening technique demonstrated to be useful for detecting candidate radioresistant genes in esophageal squamous cell carcinoma. The results of the present study revealed that the downregulation of MT-CO1 induced radioresistance occurs by inhibiting the activation of the caspase cascade in radioresistant esophageal cancer cells.

Comprehensive screening of genes resistant to an anticancer drug in esophageal squamous cell carcinoma.

Drug resistance to chemotherapy is a major issue in esophageal cancer management. Drug resistance may be mediated by genetic changes in the tumor; therefore, the identification of gene mutations may lead to better therapeutic outcomes. We used a novel method involving transposons to screen and identify drug-resistant genes. Transposons are DNA sequences that move from one location on the gene to another. A modified piggyBac transposon was designed as an insertion mutagen, and a cytomegalovirus (CMV) promoter sequence was added to induce strong transcription. When the transposon is inserted to the upstream of a certain gene, the gene will be overexpressed while when intserted down or intragenically, it will be downregulated. After establishing a transposon-tagged cell library, we treated cell lines derived from esophageal squamous cell carcinomas (ESCC) [Tohoku esophagus (TE)] with cisplatin (CDDP). We performed splinkerette PCR and TOPO cloning on the resistant colonies. Bacterial colonies were sequenced, and next-generation sequencing was used to identify the overexpressed/downregulated sequences as candidate genes for CDDP resistance. We established 4 cell lines of transposon-tagged cells, TE4, 5, 9 and 15. We treated the two relatively viable cell lines, TE4 and TE15, with CDDP. We identified 37 candidate genes from 8 resistant colonies. Eight genes were overexpressed whilst 29 were downregulated. Among these genes was Janus kinase 2 (JAK2) that is implicated in the progression of myeloproliferative neoplasms. We identified 37 candidate genes responsible for CDDP resistance in the two cell lines derived from ESCC cells. The method is inexpensive, relatively simple, and capable of introducing activating and de-activating mutations in the genome, allowing for drug-resistant genes to be identified.

Formation of abdominal cerebrospinal fluid pseudocyst.

A 63-year-old man who underwent insertion of a lumboperitoneal shunt developed gait disturbance. He had undergone surgery for gastric cancer 7 years and for ileus 5 years previously. Head computed tomography (CT) revealed enlargement of the ventricles. Abdominal CT revealed a cyst in the abdominal region and the distal segment of the peritoneal shunt tube located within the cyst. Laparotomy revealed the cyst located between the small intestine, colon, and peritoneum. The anterior wall of the cyst was excised. The distal segment of the peritoneal shunt tube was replaced in the rectovesical pouch. Histological examination showed that the cyst wall consisted of inner fibrous tissue and outer fat tissue without epithelial lining, and invasion of lymphocytes. The diagnosis was pseudocyst. Only 29 cases of abdominal cerebrospinal fluid (CSF) pseudocysts have been reported in adults. Although the mechanism underlying the formation of abdominal pseudocyst remains to be clarified, several predisposing factors for cyst formation have been reported including changes in absorption of CSF due to inflammation or infection, peritoneal adhesions due to previous abdominal surgery, and increase in the protein content of the CSF. In our case, the medical history and histological features of the cyst wall indicated that formation of the abdominal pseudocyst was associated with previous surgery or inflammatory reaction.

Laparoscopy-assisted total gastrectomy for advanced gastric cancer with carcinomatous ascites after S1 plus cisplatin chemotherapy: a case report.

A 29-year-old man with a type 4 tumor, in the lower third of the stomach, and carcinomatous ascites was diagnosed by aspiration cytology of the ascitic fluid. Curative resection was considered impossible, and S1 (120 mg/d) and cisplatin (90 mg/d) were given for 21 days in 1 course. The cancer lesion showed marked remission (partial response), and the ascites completely disappeared after the fourth course. Twenty-five days after completion of the S1 treatment, laparoscopy-assisted total gastrectomy was performed. Histopathological examination showed no remnant cancer cells in the resected specimen and no lymph node metastases. The tumor was replaced with fibrosis having a granulomatous change. The patient's postoperative course was uneventful. The patient was continued with S1 monotherapy after surgery, and no signs of recurrence or metastases have been seen on any examination 12 months after the surgery.