Efficacy of Coagulofibrinolytic Markers for Postoperative Prediction of Venous Thromboembolism in Colorectal Surgery Patients: A Retrospective Observational Study.

Objectives: A low rate of the incidence of venous thromboembolism (VTE) after surgeries that are preoperatively classified as having high risk of VTE has been reported in recent years. We seek to identify the optimal cases to receive perioperative pharmacologic thromboprophylaxis. In this study, we evaluated the incidence rate of VTE among patients undergoing colorectal surgery who did not receive perioperative pharmacologic thromboprophylaxis, and the ability of coagulofibrinolytic markers to predict the postoperative development of VTE. Methods: We retrospectively analyzed the rate of postoperative development of VTE in 70 patients undergoing elective colorectal surgery without perioperative pharmacologic thromboprophylaxis and the ability of coagulofibrinolytic markers to predict the development of VTE. Results: The incidence of VTE was observed in 11 patients (15.7%); all cases were asymptomatic and distal-type deep vein thrombosis (DVT). Comparisons of time course changes in perioperative coagulofibrinolytic markers between patients with and without DVT revealed significant differences in soluble fibrin (SF), thrombin-antithrombin complex (TAT), fibrin/fibrinogen degradation product (FDP) and D-dimer. Dynamic postoperative physiological coagulofibrinolytic responses were shown, but all four markers at each postoperative point demonstrated moderate accuracy (median area under the curve [AUC]: 0.788, median sensitivity: 0.865, median specificity: 0.644) for predicting the development of DVT. Conclusions: The incidence of postoperative VTE was low in patients with colorectal surgery even in those who did not receive perioperative pharmacologic thromboprophylaxis. SF, TAT, FDP and D-dimer were useful for predicting the development of DVT when we set cut-off values taking the physiological perioperative coagulofibrinolytic responses into consideration.

Cadaveric and CT angiography study of vessels around the transverse colon mesentery.

BACKGROUND: Laparoscopic and robotic surgery for transverse colon cancer are difficult due to complex fusion of the foregut and midgut and variation of the vessels of the transverse colon. Although the vessels of the right colon have been investigated, middle colic artery (MCA) variation and the relationship with vessels around the transvers colon are unknown. We investigated variation of the MCA using computed tomography angiography (CTA) and cadaver specimen and the relationship between the superior mesenteric vein (SMV) and MCA using CTA. The classification of vessels around the transverse colon may lead to safer and reliable surgery. METHODS: This study included 505 consecutive patients who underwent CTA in our institution from 2014 to 2020 and 44 cadaver specimens. Vascular anatomical classifications and relationships were analyzed using CT images. RESULTS: The MCA was defined as the arteries arising from the superior mesenteric artery (SMA) that flowed into the transverse colon at the distal ends. The classifications were as follows: type I, branching right and left from common trunk; type II, the right and left branches bifurcated separately from the SMA; and type III, the MCA branched from a vessel other than the SMA. Type II was subclassified into two subtypes, type IIa with one left branch and type IIb with two or more left branches from SMA. In the CTA and cadaver studies, respectively, the classifications were as follows: type I, n = 290 and n = 31; type IIa, n = 211 and n = 13; type IIb, n = 3 and n = 0; and type III, n = 1 and n = 0. We classified the relationship between the MCA and left side of the SMV into three types: type A, a common trunk runs along the left edge of the SMV (n = 173; 59.7%); type B, a right branch of the MCA runs along the left edge of the SMV (n = 116; 40.0%); and type C, the MCA runs dorsal of the SMV (n = 1; 0.3%). CONCLUSIONS: This study revealed that The MCA branching classifications and relationship between the SMV and MCA. Preoperative CT angiography may be able to reliably identify vessel variation, which may be useful in clinical practice.

Impact of the hospital volume and setting on postoperative complications of surgery for gastroenterological cancers in a regional area of Western Japan.

PURPOSE: A research subgroup was established by the Japanese Society of Gastroenterological Surgery to improve the health care quality in the Chushikoku area of Western Japan. METHODS: The records of four surgical procedures were extracted from the Japanese National Clinical Database and analyzed retrospectively to establish the association between hospital characteristics, defined using a combination of hospital case-volume and patients' hospital travel distance, and the incidences of perioperative complications of ≥ Grade 3 of the Clavien-Dindo classification after gastroenterological surgery. RESULTS: This study analyzed 11,515 cases of distal gastrectomy for gastric cancer, 4,705 cases of total gastrectomy for gastric cancer, 4,996 cases of right hemicolectomy for colon cancer, and 5,243 cases of lower anterior resection for rectal cancer, with composite outcome incidences of 5.6%, 10.2%, 5.5%, and 10.7%, respectively. After adjusting for patient characteristics and surgical procedures, no association was identified between the hospital category and surgical outcomes. CONCLUSION: The findings of our study of the Chushikoku region did not provide positive support for the consolidation and centralization of hospitals, based solely on hospital case volume. Our grouping was unique in that we included patient travel distance in the analysis, but further investigations from other perspectives are needed.

Pulmonary and Disseminated Mycobacterium avium Complex Cases Confirmed by Tissue-Direct Polymerase Chain Reaction-Based Nucleic Acid Lateral Flow Immunoassay of Formalin-Fixed Paraffin-Embedded Tissues.

Background: Detection of Mycobacterium avium complex (MAC) in tissue is essential for the diagnosis of MAC infections when the Mycobacterium is not isolated from sputum. However, detection of MAC in paraffin-embedded sections has not been established. Methods: We encountered two patients with suspected MAC infections after surgery: patient 1 had a pulmonary nodule that was initially suspected to be lung cancer and was excised under video-assisted thoracoscopic surgery (VATS). Patient 2, who was under treatment with steroids and anti-IL-6 inhibitors for rheumatoid arthritis, was suspected to have disseminated ileocecal cancer with metastasis to the lung and skin. In both cases, we postoperatively detected MAC genes in paraffin-embedded tissue sections using the novel mycobacterial nucleic acid identification test, ie tissue-direct polymerase chain reaction (tdPCR)-based nucleic acid lateral flow immunoassay (NALFIA). Both patients showed granulomatous lesions with hematoxylin-eosin staining, and mycobacteria by Ziehl-Neelsen staining in tissue sections from the lung and skin, respectively, although MAC were not isolated from the sections. MAC genes were finally detected by tdPCR-NALFIA in both cases. Conclusion: Although Ziehl-Neelsen staining and culture tests are the gold standard in identifying causative mycobacteria, the rapid results of tdPCR-NALFIA performed simultaneously with sputum and/or tissue culture may make it an important auxiliary diagnostic tool for identifying mycobacterial infection, leading to improvement in the management of MAC patients.

Long-term prognosis of laparoscopic gastrectomy for patients on antithrombotic therapy: a retrospective cohort study.

PURPOSE: Few studies have reported on the interactions between gastrectomy and antithrombotic therapy, especially the long-term prognosis. We aimed to clarify the short- and long-term prognosis of gastrectomy for patients on antithrombotic therapy. METHODS: We reviewed the perioperative data and survival rate of patients who underwent laparoscopic distal gastrectomy (LDG) at our institute between 2010 and 2013. RESULTS: There were 119 patients enrolled in this retrospective study: 31 who were taking antithrombotic drugs (antithrombotic therapy (ATT) group), and 88 who were not (non-ATT group). The mean age was significantly higher in the ATT group than in the non-ATT group. No significant differences were observed in the amount of intraoperative bleeding or blood hemoglobin level after surgery between the groups. Bleeding complications occurred in only one patient from the ATT group, and the postoperative complication rate was comparable between the groups. During follow-up, cerebrovascular or cardiovascular events developed in 19.4% of the ATT group patients and 4.5% of the non-ATT group patients; however, there were no significant differences in the 5-year overall survival rates between the groups (ATT group, 76.9%; non-ATT group, 82.9%). CONCLUSIONS: Antithrombotic therapy did not affect the short-term or long-term prognosis of patients after LDG.

A case of successful laparoscopic intraperitoneal onlay mesh plus technique repair for perineal hernia after laparoscopic abdominoperineal resection.

The frequency of secondary perineal hernia after abdominoperineal resection has been reported as 0.83%-26%. The optimal surgery for secondary perineal hernia and surgical indication remains controversial. An 87-year-old woman diagnosed with lower rectal cancer underwent laparoscopic abdominoperineal resection. Follow-up computed tomography at 6 months postoperatively revealed secondary perineal hernia. She reported no discomfort and no incarceration was apparent, but she complained of perineal discomfort 3 months later. Laparoscopic repair surgery was performed using an intraperitoneal onlay mesh plus technique with VENTRALIGHT® ST mesh (Medicon, Osaka, Japan), a non-absorbable mesh with a biodegradable coating. No recurrence of peritoneal hernia was seen as of 3 months postoperatively. A time lag can exist between imaging findings and symptom appearance. This laparoscopic intraperitoneal onlay mesh plus technique might become the optimal treatment for perineal hernia.

Tumor Screening, Incidence, and Treatment for Patients with Severe Motor and Intellectual Disabilities.

BACKGROUND: The increasing age of patients with severe motor and intellectual disabilities (SMID) has become a serious concern. Few studies have investigated tumor treatment in this population. METHODS: Tumor treatments for 12 SMID patients were examined. RESULTS: Blood tests and ultrasonography were useful for screening. With regard to treatment, surgery for SMID patients was performed in the same manner as for patients without SMID, and the results were generally satisfactory, without major complications. Typically, cancer was diagnosed at an advanced stage, and many metachronous double cancers were observed. CONCLUSIONS: Treatment yielded satisfactory results for patients with SMID and their families. Future studies should examine the clinical significance of screening and tumor operative method for patients with SMID.

Perioperative coagulofibrinolytic responses in colorectal surgery patients without chemical thromboprophylaxis: a retrospective observational study.

PURPOSE: During the perioperative period, coagulofibrinolytic activation occurs, which occasionally results in thromboembolic complications. However, natural perioperative coagulofibrinolytic responses have not been well investigated. The present study examined perioperative coagulofibrinolytic changes and their association with the development of venous thromboembolism (VTE). METHODS: We retrospectively analyzed the changes in coagulofibrinolytic markers for 7 days in 70 patients undergoing elective colorectal surgery. To explore the natural coagulofibrinolytic response, we investigated patients not undergoing perioperative chemical thromboprophylaxis. RESULTS: Coagulation activation occurred from just after surgery to postoperative day (POD) 1, followed by a gradual decrease, but persisted to even POD 7. Fibrinolytic activity showed a tri-phasic response: activation, shutdown and reactivation. Consequently, fibrin/fibrinogen degradation product (FDP) and D-dimer levels continued to increase until POD 7. The development of deep vein thrombosis (DVT) was observed in 11 patients (15.7%). Postoperative sustained hyper-coagulation [soluble fibrin (SF) or thrombin-antithrombin complex (TAT) values on POD 7 > their normal limits] was significantly associated with the development of DVT (SF, p < 0.001; TAT, p = 0.001). CONCLUSION: We found initial coagulation activation and a tri-phasic response of fibrinolytic activity after colorectal surgery. Thus, physicians need to pay attention to these responses when attempting to prevent or treat VTE.

The arrival time of indocyanine green in tissues can be a quantitative index because of its correlation with tissue oxygen saturation: A clinical pilot study.

Indocyanine green (ICG) fluorescence angiography has recently been reported useful as a method for predicting intestinal blood flow and may reduce anastomotic leakage. However, the quantification method for ICG fluorescence angiography has not been established. We usually measure the tissue oxygen saturation (StO2 ) in the intestinal tract via near-infrared spectroscopy, as it is able to measure the oxygen concentration accurately and immediately shows objective data. In this study, we propose that the time to reach the anastomotic site after intravenous ICG injection is an effective parameter for quantifying ICG fluorescence angiography from the comparison to the data of StO2 in the intestinal tract.

Chloride intracellular channel protein 2 is secreted and inhibits MMP14 activity, while preventing tumor cell invasion and metastasis.

The abilities to invade surrounding tissues and metastasize to distant organs are the most outstanding features that distinguish malignant from benign tumors. However, the mechanisms preventing the invasion and metastasis of benign tumor cells remain unclear. By using our own rat distant metastasis model, gene expression of cells in primary tumors was compared with that in metastasized tumors. Among many distinct gene expressions, we have focused on chloride intracellular channel protein 2 (CLIC2), an ion channel protein of as-yet unknown function, which was predominantly expressed in the primary tumors. We created CLIC2 overexpressing rat glioma cell line and utilized benign human meningioma cells with naturally high CLIC2 expression. CLIC2 was expressed at higher levels in benign human brain tumors than in their malignant counterparts. Moreover, its high expression was associated with prolonged survival in the rat metastasis and brain tumor models as well as with progression-free survival in patients with brain tumors. CLIC2 was also correlated with the decreased blood vessel permeability likely by increased contents of cell adhesion molecules. We found that CLIC2 was secreted extracellularly, and bound to matrix metalloproteinase (MMP) 14. Furthermore, CLIC2 prevented the localization of MMP14 in the plasma membrane, and inhibited its enzymatic activity. Indeed, overexpressing CLIC2 and recombinant CLIC2 protein effectively suppressed malignant cell invasion, whereas CLIC2 knockdown reversed these effects. Thus, CLIC2 suppress invasion and metastasis of benign tumors at least partly by inhibiting MMP14 activity.

Development of biparatopic bispecific antibody possessing tetravalent scFv-Fc capable of binding to ROBO1 expressed in hepatocellular carcinoma cells.

There is no standard structural format of the biparatopic bispecific antibody (bbsAb) which is used against the target molecule because of the diversity of biophysical features of bispecific antibodies (bsAbs). It is therefore essential that the interaction between the antibody and antigen is quantitatively analyzed to design antibodies that possess the desired properties. Here, we generated bsAbs, namely, a tandem scFv-Fc, a diabody-Fc, and an immunofusion-scFv-Fc-scFv, that possessed four scFv arms at different positions and were capable of recognizing the extracellular domains of ROBO1. We examined the interactions between these bsAbs and ROBO1 at the biophysical and cellular levels. Of these, immunofusion-B2212A scFv-Fc-B5209B scFv was stably expressed with the highest relative yield. The kinetic and thermodynamic features of the interactions of each bsAb with soluble ROBO1 (sROBO1) were validated using surface plasmon resonance and isothermal titration calorimetry. In all bsAbs, the immunofusion-scFv-Fc-scFv format showed homogeneous interaction with the antigen with higher affinity compared with that of monospecific antibodies. In conclusion, our study presents constructive information to design druggable bbsAbs in drug applications.

Paraovarian Cyst Torsion in a Patient with Rubinstein-Taybi Syndrome: A Case Report.

Rubinstein-Taybi syndrome is an extremely rare autosomal dominant genetic disorder that occurs in 1/125,000 and is characterized by distinctive facial appearance, short stature, mild to severe mental retardation, and higher risk for cancer. In addition, variable organ anomalies had been reported. Paraovarian cyst causing torsion of the ipsilateral fallopian tube is less common, with an estimated incidence of 1/1,500,000, but it can adversely affect tubal function. It occurs mainly in women in the reproductive age and is very rare in prepubescent girls. Here, we described the successful treatment of an extremely rare case of paraovarian cyst causing torsion of the ipsilateral fallopian tube in a patient with Rubinstein-Taybi syndrome. A 14-year-old girl with Rubinstein-Taybi syndrome was referred to our hospital for abdominal pain. Her medical history was unremarkable, except for moderate hirsutism and keloid scar. Physical examination revealed tenderness in the lower abdominal midline. The preoperative diagnosis was torsion of a left ovarian cyst. An exploratory laparoscopy was performed because of acute abdominal pain and revealed a left fallopian tube that was twisted twice due to an ipsilateral paraovarian cyst. The huge paraovarian cyst required laparotomy cystectomy, and the left ovary was preserved. Her postoperative course was uncomplicated. Preoperative diagnosis of paraovarian cysts can be difficult. The moderate hirsutism seen in our patient suggested the presence of a large paraovarian cyst due to androgen receptor-mediated effects. Therefore, Rubinstein-Taybi syndrome patients with hirsutism should be screened and assessed by pediatric surgeons for the presence of paraovarian cysts.

Hypertensive Cardiomyopathy with Congestive Heart Failure in an Infant with Unilateral Wilms Tumor: A Case Report.

Wilms tumor (WT) is the most common malignant kidney tumor in children. High blood pressure is seen in up to 55% of children with WT. However, hypertensive cardiomyopathy with congestive heart failure due to WT is remarkably rare, with only several cases reported worldwide. In this report, a pediatric case of WT with hypertension causing hypertensive cardiomyopathy and congestive heart failure is presented. An 8-month-old male child with abdominal distension was seen by his primary physician. He was referred to our hospital for further examination and treatment. Abdominal contrast-enhanced computed tomography demonstrated a weakly enhancing, large abdominal mass, which was larger than 12 cm. Two-dimensional transthoracic echocardiography showed a diffuse hypokinetic left ventricle. The patient was diagnosed with cardiomyopathy caused by hypertension. Open surgical resection of the mass was successfully performed. His postoperative course was uncomplicated, and the patient was successfully discharged. The plasma renin activity was maintained at a high level even after left nephrectomy, suggesting that the right kidney was likely the source of renin secretion. Mechanical compression of the right renal blood vessels by a greatly enlarged left kidney can cause right renal ischemia, which activates renin excretion. Nephrectomy can be an effective treatment for a WT patient with hypertension causing hypertensive cardiomyopathy, and then cardiac function will be improved within several weeks. We recommend routine echocardiography surveillance in patients with WT. This report can help pediatric surgeons become more familiar with cardiomyopathy caused by WT.

Sudden onset of sleep caused by hypothalamic infarction: a case report.

BACKGROUND: Hypothalamic lesions, such as tumors and demyelinating diseases, reportedly cause abnormal sleepiness. However, stroke involving the hypothalamus has rarely been described. Here, we report a patient with infarction restricted to the hypothalamus who presented with sudden onset of sleep. CASE PRESENTATION: A 42-year-old woman with a history of migraine without aura presented with irresistible sleepiness and developed several episodes of sudden onset of sleep. Neurological examinations were unremarkable except for partial left Horner syndrome. Brain magnetic resonance imaging (MRI) revealed a high-intensity lesion restricted to the left hypothalamus on diffusion-weighted and fluid-attenuated inversion recovery MRI images. Cerebrospinal fluid (CSF) orexin-A levels obtained on hospital day 3 after her sleepiness had resolved were normal (337 pg/mL; normal > 200 pg/mL). Serum anti-nuclear and anti-aquaporin 4 (AQP4) antibodies and CSF myelin basic protein and oligoclonal band were negative. A small hypothalamic infarction was suspected, and the patient was treated with intravenous edaravone and argatroban, as well as oral clopidogrel. Three months later, there had been no clinical relapse, and the hypothalamic lesion had almost disappeared on follow-up MRI. No new lesion suggestive of demyelinating disease or tumor was observed. CONCLUSION: Hypothalamic stroke should be considered a cause of sudden onset of sleep.

Usefulness of the HyperEye Medical System in Obstructive Colitis Proximal to Colon Carcinoma.

Obstructive colitis (OC) is a nonspecific inflammatory condition that occurs at the proximal side of a completely or partially stenotic lesion typically caused by colorectal cancer. Impaired blood flow caused by these stenotic changes in the colon or rectum results in this condition. During surgery for sigmoid colon carcinoma with OC, complete surgical removal of the OC lesions is required. However, it is difficult to anticipate the range of OC before surgery. Diagnosing the potential ischemia during surgery would decrease the need for re-operation. This is the first report of HyperEye Medical System (HEMS) angiography for surgery of colon cancer with OC. We report a case of sigmoid colon carcinoma in which HEMS angiography was used and found to be useful for real-time detection of the OC lesion.

Chloride intracellular channel protein 2 in cancer and non-cancer human tissues: relationship with tight junctions.

Chloride intracellular channel protein 2 (CLIC2) belongs to the CLIC family of conserved metazoan proteins. Although CLICs have been identified as chloride channels, they are currently considered multifunctional proteins. CLIC2 is the least studied family member. We investigated CLIC2 expression and localization in human hepatocellular carcinoma, metastatic colorectal cancer in the liver, and colorectal cancer. Significant expression of mRNAs encoding CLIC1, 2, 4, and 5 were found in the human tissues, but only CLIC2 was predominantly expressed in non-cancer tissues surrounding cancer masses. Fibrotic or dysfunctional (aspartate aminotransferase ≥40) non-cancer liver tissues and advanced stage HCC tissues expressed low levels of CLIC2. Endothelial cells lining blood vessels but not lymphatic vessels in non-cancer tissues expressed CLIC2 as well as high levels of the tight junction proteins claudins 1 and 5, occludin, and ZO-1. Most endothelial cells in blood vessels in cancer tissues had very low expressions of CLIC2 and tight junction proteins. CD31+/CD45- endothelial cells isolated from non-cancer tissues expressed mRNAs encoding CLIC2, claudin 1, occludin and ZO-1, while similar cell fractions from cancer tissues had very low expressions of these molecules. Knockdown of CLIC2 expression in human umbilical vein endothelial cells (HUVECs) allowed human cancer cells to transmigrate through a HUVEC monolayer. These results suggest that CLIC2 may be involved in the formation and/or maintenance of tight junctions and that cancer tissue vasculature lacks CLIC2 and tight junctions, which allows the intravasation of cancer cells necessary for hematogenous metastasis.

SNX9 determines the surface levels of integrin ß1 in vascular endothelial cells: Implication in poor prognosis of human colorectal cancers overexpressing SNX9.

Angiogenesis, the formation of new blood vessels, is involved in a variety of diseases including the tumor growth. In response to various angiogenic stimulations, a number of proteins on the surface of vascular endothelial cells are activated to coordinate cell proliferation, migration, and spreading processes to form new blood vessels. Plasma membrane localization of these angiogenic proteins, which include vascular endothelial growth factor receptors and integrins, are warranted by intracellular membrane trafficking. Here, by using a siRNA library, we screened for the sorting nexin family that regulates intracellular trafficking and identified sorting nexin 9 (SNX9) as a novel angiogenic factor in human umbilical vein endothelial cells (HUVECs). SNX9 was essential for cell spreading on the Matrigel, and tube formation that mimics in vivo angiogenesis in HUVECs. SNX9 depletion significantly delayed the recycling of integrin ß1, an essential adhesion molecule for angiogenesis, and reduced the surface levels of integrin ß1 in HUVECs. Clinically, we showed that SNX9 protein was highly expressed in tumor endothelial cells of human colorectal cancer tissues. High-level expression of SNX9 messenger RNA significantly correlated with poor prognosis of the patients with colorectal cancer. These results suggest that SNX9 is an angiogenic factor and provide a novel target for the development of new antiangiogenic drugs.

Optimal monochromatic color combinations for fusion imaging of FDG-PET and diffusion-weighted MR images.

OBJECTIVE: To investigate the optimal monochromatic color combination for fusion imaging of FDG-PET and diffusion-weighted MR images (DW) regarding lesion conspicuity of each image. METHODS: Six linear monochromatic color-maps of red, blue, green, cyan, magenta, and yellow were assigned to each of the FDG-PET and DW images. Total perceptual color differences of the lesions were calculated based on the lightness and chromaticity measured with the photometer. Visual lesion conspicuity was also compared among the PET-only, DW-only and PET-DW-double positive portions with mean conspicuity scores. Statistical analysis was performed with a one-way analysis of variance and Spearman's rank correlation coefficient. RESULTS: Among all the 12 possible monochromatic color-map combinations, the 3 combinations of red/cyan, magenta/green, and red/green produced the highest conspicuity scores. Total color differences between PET-positive and double-positive portions correlated with conspicuity scores (ρ = 0.2933, p < 0.005). Lightness differences showed a significant negative correlation with conspicuity scores between the PET-only and DWI-only positive portions. Chromaticity differences showed a marginally significant correlation with conspicuity scores between DWI-positive and double-positive portions. CONCLUSIONS: Monochromatic color combinations can facilitate the visual evaluation of FDG-uptake and diffusivity as well as registration accuracy on the FDG-PET/DW fusion images, when red- and green-colored elements are assigned to FDG-PET and DW images, respectively.

Development of a postoperative occlusive thrombus at the site of an implanted inferior vena cava filter: A case report.

RATIONALE: Although an inferior vena cave (IVC) filter is placed to prevent fatal pulmonary embolism (PE), several complications associated with an IVC filter have been reported. We describe a case with symptomatic PE, of which the origin was an occlusive IVC thrombus that developed from the placement of an IVC filer after a laparoscopy-assisted total gastrectomy (LATG). PATIENT CONCERNS: A 71-year-old man underwent LATG under general anesthesia alone. He had an IVC filter implanted 13 years ago. An intravenous infusion of unfractionated heparin was substituted for the discontinuation of oral warfarin four days before the surgery. The proposed operation was performed and took a total of 404 minutes including the total duration of pneumoperitoneum that took 374 minutes. After the surgery, he experienced severe shivering reactions that required frequent bolus infusions of antihypertensive drugs. On the third postoperative day, he complained of dyspnea after taking a short walk, and subsequently lost consciousness. While he spontaneously recovered without requiring any resuscitation efforts, we performed computed tomography (CT) examination for suspected PE. DIAGNOSES: The CT showed that a massive thrombus was occupying the intravenous space from the IVC filter to the left common iliac vein with several embolic defects in the peripheral pulmonary arteries present. INTERVENTIONS: An anticoagulant therapy was established with 10 mg of oral apixaban given twice a day for the first four days, followed by a reduction to 5 mg. OUTCOMES: On the 17th postoperative day, an ultrasound vascular examination confirmed the complete disappearance of deep venous thrombus (DVT). LESSONS: As an IVC filter itself may be a potential source of DVT, we should carefully manage patients with a previously implanted IVC filter throughout the perioperative period.

Truncated CD200 stimulates tumor immunity leading to fewer lung metastases in a novel Wistar rat metastasis model.

CD200 mediates immunosuppression in immune cells that express its receptor, CD200R. There are two CD200 variants; truncated CD200 that lacks the part of N-terminal sequence necessary for CD200R binding (CD200S) and full-length CD200 (CD200L). We established a novel lung metastasis model by subcutaneously transplanting C6 glioma cells into the backs of neonatal Wistar rats. All transplanted rats developed large back tumors, nearly 90% of which bore lung metastases. To compare the effects of CD200S and CD200L on tumor immunity, CD200L (C6-L)- or CD200S (C6-S)-expressing C6 cells were similarly transplanted. The results showed that 100% of rats with C6-L tumors developed lung metastases, while metastases were found in only 44% of rats with C6-S tumors (n = 25). Tumors disappeared in approximately 20% of the C6-S-bearing rats, and these animals evaded death 180 d after transplantation, while all C6-L tumor-bearing rats died after 45 d. Next generation sequencing revealed that C6-S tumors expressed chemokines and granzyme B at much higher levels than C6-L tumors. Flow cytometry revealed that C6-S tumors contained more dead cells and more CD45+ cells, including natural killer cells and CD8+ lymphocytes. In particular, multiple subsets of dendritic cells expressing CD11c, MHC class II, CD8, and/or CD103 were more abundant in C6-S than in C6-L tumors. These results suggested that CD200S induced the accumulation of multiple dendritic cell subsets that activated cytotoxic T lymphocytes, leading to the elimination of metastasizing tumor cells.