Risk factors for anastomotic leakage after low anterior resection for obese patients with rectal cancer.

PURPOSE: We aimed to analyze the risk factors for anastomotic leakage (AL) after low anterior resection (LAR) in obese patients (body mass index [BMI] ≥ 25 kg/m2) with rectal cancer. METHODS: Data were collected from four hundred two obese patients who underwent LAR for rectal cancer in 51 institutions. RESULTS: Forty-six (11.4%) patients had clinical AL. The median BMI (27 kg/m2) did not differ between the AL and non-AL groups. In the AL group, comorbid respiratory disease was more common (p = 0.025), and the median tumor size was larger (p = 0.002). The incidence of AL was 11.5% in the open surgery subgroup and 11.4% in the laparoscopic surgery subgroup. Among the patients who underwent open surgery, the AL group showed a male predominance (p = 0.04) in the univariate analysis, but it was not statistically significant in the multivariate analysis. Among the patients who underwent laparoscopic surgery, the AL group included a higher proportion of patients with comorbid respiratory disease (p = 0.003) and larger tumors (p = 0.007). CONCLUSION: Comorbid respiratory disease and tumor size were risk factors for AL in obese patients with rectal cancer. Careful perioperative respiratory management and appropriate selection of surgical procedures are required for obese rectal cancer patients with respiratory diseases.

Activated neutrophils inhibit chemotactic migration of activated T lymphocytes to CXCL11 by multiple mechanisms.

Accumulation of T lymphocytes and neutrophils shows inversed association with the prognosis of cancer patients, suggesting infiltration of neutrophils and T cells might be differently regulated in tumor tissue. In this study, we stimulated neutrophils with PMA or LPS to produce neutrophil extracellular traps (NETs) and examined the effects on chemotactic migration of activated T cells to a representative T cell chemokine, CXCL11. Migration of the activated T cells was totally abrogated by PMA-stimulated neutrophils placed either in upper or lower chamber, which was mostly canceled by pretreatment with Catalase. Although LPS-stimulated neutrophils also inhibited T cell migration, depletion of NETs by ultracentrifugation or degradation of NETs with DNAse I restored T cell migration. Western blots showed that LPS-stimulated neutrophils thoroughly degraded CXCL11 with NETs dependent manner. Activated neutrophils inhibit T cell chemotaxis via multiple mechanisms including the release of H2O2 and chemokine degradation by NETs, which may suppress adaptive immunity.

Peripheral low-density granulocytes after colorectal cancer surgery in predicting recurrence.

BACKGROUND: Low-density granulocytes (LDGs) have been shown to be increased in the peripheral blood of patients with inflammatory and malignant diseases. This study evaluated LDGs in patients who underwent radical surgery for colorectal cancer (CRC) and their impact on survival. METHODS: Patients who underwent radical colectomy between 2017 to 2021 were screened for enrolment in the study. Peripheral blood was obtained in the operating room before and after surgery and cells were recovered from the mononuclear layer after density gradient preparations. The ratio of CD66b(+) LDG to CD45(+) leukocytes was determined with flow cytometry, and the association of the ratios with patient outcomes was examined. The main outcome of interest was recurrence-free survival (RFS). RESULTS: Out of 228 patients treated, 176 were enrolled, including 108 colonic and 68 rectal cancers. Overall, 38 patients were stage I, 30 were stage II, 72 were stage 3, and 36 were stage IV. The number of LDGs was markedly increased immediately after surgery and the proportion of LDGs correlated positively with operating time (r = 0.2806, P < 0.001) and intraoperative blood loss (r = 0.1838, P = 0.014). Purified LDGs produced high amounts of neutrophil extracellular traps after short-term culture and efficiently trapped tumour cells in vitro. The proportion of postoperative LDGs was significantly higher in 13 patients who developed recurrence (median 9 (range 1.63-47.0)) per cent versus median 2.93 ((range 0.035-59.45) per cent, P = 0.013). When cut-off values were set at 4.9 per cent, a higher proportion of LDGs was strongly and independently associated with decreased RFS (P = 0.005). In patients with stage III disease, adjuvant chemotherapy significantly improved RFS of patients with high ratios of LDGs, but not low LDGs. CONCLUSION: LDGs are recruited to circulating blood by surgical stress early in the postoperative interval after colectomy for colonic cancer and their postoperative proportion is correlated with recurrence.

The effect of staple height and rectal-wall thickness on anastomotic leakage after laparoscopic low anterior resection.

BACKGROUND: The aim of this study was to evaluate the effect of staple height and rectal wall thickness on the development of an anastomotic leak after laparoscopic low anterior resection performed with the double stapling technique. METHODS: One hundred ninety-nine patients treated from 2013 to 2021 were enrolled. Patients were divided into two groups: those who developed an anastomotic leak (AL (+)) and those who did not (AL (-)). Clinicopathological factors were compared between the groups. RESULTS: Anastomotic leaks were observed in 8/199 patients (4%). A 1.5 mm linear stapler was used for 35/199 patients (17%), 1.8 mm for 89 (45%), and 2 mm for 75 (38%). In the AL (+) group (n = 8), lower staple height (1.5 mm or 1.8 mm) was used more frequently than in the AL (-) group (n = 191). Rectal wall thickness and the rectal wall thickness to staple height ratio was significantly (p < .05) greater in the AL (+) group. However, rectal wall thickness was significantly (p < .05) greater in patients who received neoadjuvant treatment and those with advanced T stage (T3,4) lesions. CONCLUSION: Linear stapler staple height and rectal wall thickness are significantly associated with the development of an anastomotic leak after laparoscopic low anterior resection. Larger staples should be selected in patients with a thicker rectal wall due to neoadjuvant treatment or adjacent advanced rectal tumors.

Idiopathic megacolon complicated by life-threatening giant megacolon and respiratory failure due to diaphragmatic eventration: A case report.

INTRODUCTION AND IMPORTANCE: Giant megacolon requiring emergency surgery is rare. Eventration of the diaphragm associated with giant megacolon is also uncommon. CASE PRESENTATION: We report a 66-year-old male who presented with abdominal distention and progressive dyspnea. After resuscitation following cardiopulmonary arrest, the patient underwent emergent subtotal abdominal colectomy. Eventration of the diaphragm was found postoperatively and his respiratory condition was insufficient to allow liberation. Plication of both diaphragms was performed through left and right thoracotomy via the 8th intercostal space. Postoperatively the patient made a full recovery. CLINICAL DISCUSSIONS: Chronic constipation is a common health condition. A life-threatening condition secondary to chronic constipation is a rarely documented complication. Diaphragmatic eventration that was caused due to chronic megacolon in symptomatic patients requires surgical treatment. CONCLUSIONS: We describe a patient with giant megacolon and diaphragmatic eventration secondary to idiopathic megacolon. The patient underwent subtotal colectomy and diaphragmatic plication and recovered fully.

Neutrophil extracellular traps (NETs) reduce the diffusion of doxorubicin which may attenuate its ability to induce apoptosis of ovarian cancer cells.

Purpose: Although neutrophil extracellular traps (NETs) are present in various tumors, their roles in tumor biology have not been clarified yet. In this study, we examined how NETs affect the pharmacokinetics and effects of doxorubicin (DOX). Methods: NETs were generated by neutrophils stimulated with phorbol 12-myristate 13-acetate (PMA) or lipopolysaccharide (LPS). DOX was added to NETs and their distribution was observed under fluorescein microscopy, and the diffusion of DOX through 3 µM pores from lower to upper chambers was evaluated with a fluorescence-based assay. Ovarian cancer cells, KOC-2S and SKOV3, were embedded in collagen gel droplets and cultured in 3D way and their apoptosis was examined with flow cytometry. Results: DOX was mostly co-localized with NETs. The transfer of DOX to upper chambers increased over time, which was significantly decreased by the presence of neutrophils stimulated with PMA or LPS in the lower chamber. DOX outside of the gel increased the rates of annexin V (+) apoptotic cells, which were significantly reduced by the addition of LPS-stimulated neutrophils in media both in KOC-2S and SKOV3. The reduced diffusion and apoptosis were mostly restored by the destruction of the NETs structure with 1000 u/ml DNAse I. Conclusion: NETs efficiently trap and inhibit the diffusion of DOX which may attenuate its ability to induce apoptosis of ovarian cancer cells. Degradation of NETs with DNAse I may augment the response of ovarian cancer to DOX.

Intestinal mucosa staple line integrity and anastomotic leak pressure after healing in a porcine model.

PURPOSE: The aim of this study was to evaluate both the intestinal mucosa staple line integrity and anastomotic leak pressure after healing in a porcine survival model. METHODS: We used two suture models using two different size staples (incomplete mucosal closure model: group G [staple height 0.75 mm], complete mucosal closure model: group B [staple height 1.5 mm]) in the porcine ileum. Five staple lines were created in each group made in the ileum for each model, and the staple sites harvested on days 0, 2, and 7. The leak pressure at the staple site was measured at each time point. RESULTS: On day 0, the leak pressure for group G (79.5 mmHg) was significantly lower than that for group B (182.3 mmHg) (p < 0.01). On days 2 and 7, there was no significant difference between groups G and B (171 mmHg and 175.5 mmHg on day 2, 175.5 mmHg and 175.5 mmHg on day 7, p > 0.05). The histological findings in both groups showed similar healing at postoperative days 2 and 7. CONCLUSION: The integrity of the mucosal staple lines was associated with the postoperative leak pressure on day 0. However, there was no association with the leak pressure at two days or more postoperatively in a porcine model.

Flow cytometry detection of cell type-specific expression of programmed death receptor ligand-1 (PD-L1) in colorectal cancer specimens.

AIM: PD-1/PD-L1 blockade therapy is now widely used for the treatment of advanced malignancies. Although PD-L1 is known to be expressed by various host cells as well as tumor cells, the role of PD-L1 on non-malignant cells and its clinical significance is unknown. We evaluated cell type-specific expression of PD-L1 in colorectal cancer (CRC) specimens using multicolor flow cytometry. METHODS: Single cell suspensions were made from 21 surgically resected CRC specimens, and immunostained with various mAbs conjugated with different fluorescent dyes. Tumor cells, stromal cells, and immune cells were identified as CD326(+), CD90(+) and CD45(+) phenotype, respectively. CD11b(+) myeloid cells, CD19(+) B cells and CD4(+) or CD8(+) T cells were also stained in different samples, and their frequencies in the total cell population and the ratio of PD-L1(+) cells to each phenotype were determined. RESULTS: PD-L1 was expressed by all the cell types. The ratio of PD-L1(+) cells to CD326(+) tumor cells was 19.1% ± 14.0%, lower than those for CD90(+) stromal cells (39.6% ± 16.0%) and CD11b(+) myeloid cells (31.9% ± 14.3%). The ratio of PD-L1(+) cells in tumor cells correlated strongly with the ratio in stromal cells, while only weakly with that in myeloid cells. Tumor cells were divided into two populations by CD326 expression levels, and the PD-L1 positive ratios were inversely correlated with the rate of CD326 highly expressing cells as well as mean fluorescein intensity of CD326 in tumor cells, while positively correlated with the frequencies of stromal cells or myeloid cells in CRC. CONCLUSION: PD-L1 is differentially expressed on various cell types in CRC. PD-L1 on tumor cells may be upregulated together with CD326 downregulation in the process of epithelial mesenchymal transition. Quantification of cell type-specific expression of PD-L1 using multicolor flow cytometry may provide useful information for the immunotherapy of solid tumors.

Colonoscopic Treatment of a Fecaloma at the Anastomotic Site after Colectomy.

Fecalomas most commonly occur in constipated patients and are rarely reported after colectomy. A 55-year-old Japanese female presented with a fecaloma after colectomy, which was impacted at a functional end-to-end anastomosis (FEEA) site. Four and a half years ago, she underwent sigmoidectomy for colon cancer. A follow-up computed tomography (CT) scan revealed an 11 cm incidental fecaloma. The patient was advised to undergo surgery, but she desired nonoperative management because of minimal symptoms, and was referred to our institution. On the day of admission (day 1), mechanical fragmentation of the fecaloma was attempted during the first colonoscopy. Although a large block of stool was evacuated after a second colonoscopic fragmentation on day 8, the third colonoscopy on day 21 and CT scan on day 22 showed no significant change in the fecaloma. Frequent colonoscopic fragmentation was performed, with a fourth, fifth, and sixth colonoscopy on days 24, 29, and 31, respectively. After the size reduction was confirmed at the sixth colonoscopy, the patient was discharged home on day 34. The fecaloma completely resolved after the seventh colonoscopic fragmentation on day 44. Sixteen months after treatment, there is no evidence of recurrent fecaloma. According to the literature, risk factors for fecaloma after colectomy include female gender, left-side colonic anastomosis, and FEEA. FEEA might not be recommended for anastomoses in the left colon, particularly in female patients, to avoid this complication. Colonoscopic fragmentation is recommended for fecalomas at an anastomotic site after colectomy in patients without an absolute indication for surgery.

Goblet cell carcinoid of the rectum: a case report.

BACKGROUND: Goblet cell carcinoid (GCC) is a neuroendocrine tumor usually found in the appendix. GCCs exhibit characteristic findings with mixed endocrine-exocrine features such as staining positive for neuroendocrine markers and producing mucin. The primary GCC of the rectum is exceedingly rare. CASE PRESENTATION: A 77-year-old Japanese male presented with hematochezia. Anal tenderness and a hard mass in the anal canal were found on the digital rectal examination, and colonoscopy was performed. Colonoscopy showed an irregularly shaped mass in the anal canal. Biopsy showed mixed features including adenocarcinoma in situ, well-differentiated adenocarcinoma, and mucinous carcinoma with invasive proliferation. No metastatic lesions were found on the computed tomography scan. Pelvic magnetic resonance imaging scan showed extramural growth of a tumor on the ventral side of the rectum without invasion to the prostate. Laparoscopic abdominoperineal resection was performed. The final diagnosis was well-differentiated adenocarcinoma in the mucosa and goblet cell carcinoid from the submucosa to the adventitia of the rectum. The patient was discharged from the hospital on postoperative day 16. Six months after resection, a computed tomography scan revealed multiple metastatic lesions in the liver. Several chemotherapy regimens were given, and the patient has stable disease 27 months after surgery. CONCLUSION: We present a patient with rectal GCC with metachronous liver metastases. Since GCC grows intramurally and is biologically aggressive compared to typical carcinoid lesions, the disease is usually diagnosed at an advanced stage. The development of optimal adjuvant chemotherapy is needed for those patients.

NLRP3 Inflammasome Activation in Lung Vascular Endothelial Cells Contributes to Intestinal Ischemia/Reperfusion-Induced Acute Lung Injury.

Intestinal ischemia/reperfusion (I/R) injury is a life-threatening complication that leads to inflammation and remote organ damage. The NLRP3 inflammasome regulates the caspase-1-dependent release of IL-1ß, an early mediator of inflammation after I/R injury. In this study, we investigated the role of the NLRP3 inflammasome in mice with intestinal I/R injury. Deficiency of NLRP3, ASC, caspase-1/11, or IL-1ß prolonged survival after intestinal I/R injury, but neither NLRP3 nor caspase-1/11 deficiency affected intestinal inflammation. Intestinal I/R injury caused acute lung injury (ALI) characterized by inflammation, reactive oxygen species generation, and vascular permeability, which was markedly improved by NLRP3 deficiency. Bone marrow chimeric experiments showed that NLRP3 in non-bone marrow-derived cells was the main contributor to development of intestinal I/R-induced ALI. The NLRP3 inflammasome in lung vascular endothelial cells is thought to be important to lung vascular permeability. Using mass spectrometry, we identified intestinal I/R-derived lipid mediators that enhanced NLRP3 inflammasome activation in lung vascular endothelial cells. Finally, we confirmed that serum levels of these lipid mediators were elevated in patients with intestinal ischemia. To our knowledge, these findings provide new insights into the mechanism underlying intestinal I/R-induced ALI and suggest that endothelial NLRP3 inflammasome-driven IL-1ß is a novel potential target for treating and preventing this disorder.

Iron overload as a risk factor for hepatic ischemia-reperfusion injury in liver transplantation: Potential role of ferroptosis.

Hepatic ischemia-reperfusion (I/R) injury is a major problem in liver transplantation (LT). Although hepatocyte cell death is the initial event in hepatic I/R injury, the underlying mechanism remains unclear. In the present study, we retrospectively analyzed the clinical data of 202 pediatric living donor LT and found that a high serum ferritin level, a marker of iron overload, of the donor is an independent risk factor for liver damage after LT. Since ferroptosis has been recently discovered as an iron-dependent cell death that is triggered by a loss of cellular redox homeostasis, we investigated the role of ferroptosis in a murine model of hepatic I/R injury, and found that liver damage, lipid peroxidation, and upregulation of the ferroptosis marker Ptgs2 were induced by I/R, and all of these manifestations were markedly prevented by the ferroptosis-specific inhibitor ferrostatin-1 (Fer-1) or α-tocopherol. Fer-1 also inhibited hepatic I/R-induced inflammatory responses. Furthermore, hepatic I/R injury was attenuated by iron chelation by deferoxamine and exacerbated by iron overload with a high iron diet. These findings demonstrate that iron overload is a novel risk factor for hepatic I/R injury in LT, and ferroptosis contributes to the pathogenesis of hepatic I/R injury.

Role of TLR5 in inflammation and tissue damage after intestinal ischemia-reperfusion injury.

BACKGROUND: Intestinal ischemia/reperfusion (I/R) injury is a life-threatening complication that leads to inflammation and remote organ damage. However, the underlying mechanism is not yet fully understood. Toll-like receptor 5 (TLR5) is highly expressed in mucosa and recognizes flagellin, the main component of the bacterial flagella. Here, we investigated the role of TLR5 in inflammation and tissue damage after intestinal I/R injury using TLR5-deficient mice. METHODS AND RESULTS: Intestinal levels of TLR5 mRNA and flagellin protein were elevated in wild-type mice subjected to intestinal I/R. Although TLR5 deficiency had no effect on intestinal flagellin levels, it significantly attenuated intestinal injury and inflammatory responses after intestinal I/R. TLR5 deficiency also markedly improved survival in mice after intestinal I/R injury. In wild-type mice, intestinal I/R injury induced remote organ damage, particularly in the lung, which was attenuated by TLR5 deficiency. Furthermore, TLR5 deficiency prevented lung inflammatory responses and vascular permeability after intestinal I/R injury. CONCLUSION: These findings demonstrate a novel role of TLR5 and provide new insights into the mechanism underlying inflammation and tissue damage after intestinal I/R injury.

Four-directional approach to the meso-transverse attachment combined with preoperative radiological vascular simulation facilitates short-term surgical outcomes in laparoscopic transverse colon cancer surgery.

INTRODUCTION: Transverse colon resection is one of the most difficult laparoscopic procedures because of anatomic hazards such as variations in the mesenteric vascular anatomy and the complex structure of organs and surrounding membranes. METHODS: We evaluated the short-term surgical outcomes of laparoscopic transverse colon resection using a creative approach. This approach included preoperative surgical simulation using virtual surgical anatomy by CT, a four-directional approach to the mesentery, and 3-D imaging during laparoscopic surgery. RESULTS: A total of 45 consecutive patients who underwent laparoscopic resection for transverse colon cancer from June 2013 to December 2017 were enrolled in this study. All procedures were completed safely, with minor postoperative complications, including two patients with anastomotic stenosis, two with intra-abdominal phlegmon, one with delayed gastric emptying, and one with pneumonia, all treated non-operatively. There were no conversions to open resection. Operation time was 203 min (range, 125-322 min), and the estimated blood loss during surgery was 5 mL (range, 0-370 mL). The mean postoperative hospital stay was 10 days (range, 7-21 days), and no patients required readmission. CONCLUSION: Short-term surgical outcomes after laparoscopic transverse colon resection demonstrated that this creative approach was safe and feasible. The four-directional approach to the meso-transverse attachment combined with preoperative radiological simulation can facilitate laparoscopic transverse colon surgery.

Duodenal gastrointestinal stromal tumors appear similar to pancreatic neuroendocrine tumors: A case report.

INTRODUCTION: Duodenal gastrointestinal tumors (GISTs) are rare. Duodenal GISTs and pancreatic neuroendocrine tumors (NETs) may appear similar on imaging studies. GISTs arising from the second or third portions of duodenum may be incorrectly diagnosed as pancreatic NETs. PRESENTATION OF CASE: The patient is a 79-year-old man who was referred to our hospital with a history of tarry stools and loss of consciousness. Urgent upper digestive tract endoscopy revealed a bleeding submucosal duodenal lesion, which was controlled using endoscopic clips. Enhanced computed tomography scan showed a hyper-vascular mass 50 mm in diameter, at the pancreatic uncus. The patient underwent a pylorus-preserving pancreaticoduodenectomy. Histologically, the tumor was composed of spindle-shaped cells immunohistochemically positive for c-kit and CD34, and the lesion diagnosed as a duodenal GIST. DISCUSSION: Duodenal GISTs often present with gastrointestinal bleeding, which can necessitate emergency surgery. Surgical resection with regional lymph node dissection is the optimal treatment for pancreatic NETs. In contrast, GISTs are generally treated with a minimal resection and without lymph node dissection. Thus, establishing the diagnosis is important in the management of these tumors. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is effective to establish the diagnosis of these lesions. CONCLUSION: A tumor located in the pancreatic head or mesenteric side of the duodenum cannot always be diagnosed based on imaging, and is ideally diagnosed histologically to guide the extent of resection. While EUS-FNA can establish the diagnosis, the complications of this procedure must be considered.

Adeno-associated Virus Vector-mediated Interleukin-10 Induction Prevents Vascular Inflammation in a Murine Model of Kawasaki Disease.

Kawasaki disease (KD), which is the leading cause of pediatric heart disease, is characterized by coronary vasculitis and subsequent aneurysm formation. Although intravenous immunoglobulin therapy is effective for reducing aneurysm formation, a certain number of patients are resistant to this therapy. Because interleukin-10 (IL-10) was identified as a negative regulator of cardiac inflammation in a murine model of KD induced by Candida albicans water-soluble fraction (CAWS), we investigated the effect of IL-10 supplementation in CAWS-induced vasculitis. Mice were injected intramuscularly with adeno-associated virus (AAV) vector encoding IL-10, then treated with CAWS. The induction of AAV-mediated IL-10 (AAV-IL-10) significantly attenuated the vascular inflammation and fibrosis in the aortic root and coronary artery, resulting in the improvement of cardiac dysfunction and lethality. The predominant infiltrating inflammatory cells in the vascular walls were Dectin-2+CD11b+ macrophages. In vitro experiments revealed that granulocyte/macrophage colony-stimulating factor (GM-CSF) induced Dectin-2 expression in bone marrow-derived macrophages and enhanced the CAWS-induced production of tumor necrosis factor-α (TNF-α) and IL-6. IL-10 had no effect on the Dectin-2 expression but significantly inhibited the production of cytokines. IL-10 also inhibited CAWS-induced phosphorylation of ERK1/2, but not Syk. Furthermore, the induction of AAV-IL-10 prevented the expression of TNF-α and IL-6, but not GM-CSF and Dectin-2 at the early phase of CAWS-induced vasculitis. These findings demonstrate that AAV-IL-10 may have therapeutic application in the prevention of coronary vasculitis and aneurysm formation, and provide new insights into the mechanism underlying the pathogenesis of KD.

Utility of preoperative 3-D simulation of laparoscopic lateral pelvic lymph node dissection for advanced rectal cancer: Surgical outcomes of 10 initial cases.

INTRODUCTION: Laparoscopic lateral pelvic lymph node dissection (LPLD) is technically challenging because of the complicated anatomy of the pelvic wall. To overcome this difficulty, we introduced preoperative 3-D simulation. The aim of the study is to investigate the usefulness of preoperative 3-D simulation for the safe conduct of laparoscopic LPLD for rectal cancer. METHODS: After undergoing colonoscopy, patients were brought to the radiology suite where multi-detector row CT was performed. Three-dimensional images were constructed at a workstation and showed branches of the iliac artery and vein, ureter, urinary bladder, and enlarged lymph nodes. All members of the surgical team participated in preoperative simulation using the 3-D images. RESULTS: A total of 10 patients with advanced lower rectal cancer and enlarged lateral pelvic lymph nodes underwent laparoscopic unilateral LPLD after total mesorectal excision, tumor-specific mesorectal excision, or total proctocolectomy. Four of the 10 patients (40%) had variations in pelvic vascular anatomy. The median operative time for unilateral LPLD was 91 min (range, 66-142 min) and gradually declined, suggesting a good learning curve. The median number of lateral pelvic lymph nodes harvested was nine (range, 3-16). The median estimated blood loss was 13 mL (range, 10-160 mL). No conversion to open surgery or intraoperative complications occurred. No patient had major postoperative complications. CONCLUSION: Preoperative 3-D simulation may be useful for the safe conduct of laparoscopic LPLD, especially for surgeons with limited prior experience.

Metachronous solitary metacarpal bone metastasis from rectal cancer.

Metachronous solitary metacarpal bone metastasis from rectal cancer has not been reported previously. Here, we describe a 54-year-old woman who underwent abdominoperineal resection for rectal cancer following neoadjuvant chemoradiotherapy. The resected specimen contained adenocarcinoma with no lymph node metastases (Stage II, T3N0M0); no adjuvant chemotherapy was administered. Fifteen months after surgery, the patient presented with pain and swelling of the right thumb. Radiography revealed metacarpal bone destruction, and fluorine-18 fluorodeoxyglucose positron emission tomography showed uptake only in the metacarpal bone. Open biopsy revealed an adenocarcinoma, and a right thumb resection was performed. Histological examination indicated features of adenocarcinoma similar to the findings of a rectal lesion, leading to a diagnosis of metachronous solitary metacarpal bone metastasis from rectal cancer. The patient remains free of disease after 6 years of follow-up. Our findings suggest that surgical resection may lead to favorable outcomes in patients with resectable solitary bone metastases.

Interaction of Neutrophils with Macrophages Promotes IL-1ß Maturation and Contributes to Hepatic Ischemia-Reperfusion Injury.

Accumulating evidence suggests that IL-1ß plays a pivotal role in the pathophysiology of hepatic ischemia-reperfusion (I/R) injury; however, the mechanism by which I/R triggers IL-1ß production in the liver remains unclear. Recent data have shown that neutrophils contribute to hepatic I/R injury independently of the inflammasomes regulating IL-1ß maturation. Thus, we investigated the role of neutrophils in IL-1ß maturation and tissue injury in a murine model of hepatic I/R. IL-1ß was released from the I/R liver and its deficiency reduced reactive oxygen species generation, apoptosis, and inflammatory responses, such as inflammatory cell infiltration and cytokine expression, thereby resulting in reduced tissue injury. Depletion of either macrophages or neutrophils also attenuated IL-1ß release and hepatic I/R injury. In vitro experiments revealed that neutrophil-derived proteinases process pro-IL-1ß derived from macrophages into its mature form independently of caspase-1. Furthermore, pharmacological inhibition of serine proteases attenuated IL-1ß release and hepatic I/R injury in vivo. Taken together, the interaction between neutrophils and macrophages promotes IL-1ß maturation and causes IL-1ß-driven inflammation in the I/R liver. Both neutrophils and macrophages are indispensable in this process. These findings suggest that neutrophil-macrophage interaction is a therapeutic target for hepatic I/R injury and may also provide new insights into the inflammasome-independent mechanism of IL-1ß maturation in the liver.

Caspase-1 deficiency promotes high-fat diet-induced adipose tissue inflammation and the development of obesity.

Caspase-1 is a cysteine protease responsible for the processing of the proinflammatory cytokine interleukin-1ß and activated by the formation of inflammasome complexes. Although several investigations have found a link between diet-induced obesity and caspase-1, the relationship remains controversial. Here, we found that mice deficient in caspase-1 were susceptible to high-fat diet-induced obesity with increased adiposity as well as normal lipid and glucose metabolism. Caspase-1 deficiency clearly promoted the infiltration of inflammatory macrophages and increased the production of C-C motif chemokine ligand 2 (CCL2) in the adipose tissue. The dominant cellular source of CCL2 was stromal vascular fraction rather than adipocytes in the adipose tissue. These findings demonstrate a critical role of caspase-1 in macrophage-driven inflammation in the adipose tissue and the development of obesity. These data provide novel insights into the mechanisms underlying inflammation in the pathophysiology of obesity.