The effects of coagulation factors and their inhibitors on proliferation and migration in colorectal cancer.

BACKGROUND/AIM: Clotting factors promote cancer development. We investigated if coagulation proteins promote proliferation and migration in colorectal cancer (CRC) cell lines and whether their direct inhibitors can attenuate these effects. MATERIALS AND METHODS: DLD-1 and SW620 cells were treated with tissue factor (0, 50, 100 and 500 pg/mL ± 10 µg/mL 10H10 [anti-tissue factor antibody]), thrombin (0.0, 0.1, 1.0 and 10.0 U/mL ± 0.5 µM dabigatran [thrombin inhibitor]) and Factor Xa, FXa (0.0, 0.1, 1.0 and 10.0 U/mL ± 100 ng/mL rivaroxaban [FXa inhibitor]) and their effects on proliferation and migration were quantified using the PrestoBlue® and transwell migration assays, respectively. RESULTS: Thrombin increased proliferation from 48 h treatment compared to its control (48 h 6.57 ± 1.36 u vs. 2.42 ± 0.13 u, p = 0.001, 72 h 9.50 ± 1.54 u vs. 4.50 ± 0.47 u, p = 0.004 and 96 h 10.77 ± 1.72 u vs. 5.57 ± 0.25 u, p = 0.008). This increase in proliferation was attenuated by dabigatran at 72 h (2.23 ± 0.16 u vs. 3.26 ± 0.43 u, p = 0.04). Tissue factor (0 pg/mL 20.7 ± 1.6 cells/view vs. 50 pg/mL 32.4 ± 1.9 cells/view, p = 0.0002), FXa (0.0 U/mL 8.9 ± 1.1 cells/view vs. 10.0 U/mL 17.7 ± 1.7 cells/view, p < 0.0001) and thrombin (0.0 U/mL 8.9 ± 1.3 cells/view vs. 10.0 U/mL 20.2 ± 2.0 cells/view, p < 0.0001) all increased migration compared to their controls. However, their direct inhibitors did not attenuate these increases. CONCLUSION: Thrombin, FXa and TF all increase migration in CRC in vitro. Thrombin induced increase in proliferation is abrogated by dabigatran. Dabigatran may have potential as an anti-cancer therapy in CRC.

Managing surgical demand when needs outstrip resource: qualitative investigation of colorectal cancer surgery provision in the first wave of the COVID-19 pandemic.

BACKGROUND: At the onset of the COVID-19 pandemic, elective surgical provision was severely affected by the need for hospital reorganization to care for critically ill patients. In response, National Health Service (NHS) England issued national guidance proposing acceptable time intervals for postponing different types of surgical procedure. This study reports healthcare professionals' private accounts of the strategies adopted to manage the imbalance of demand and resource, using colorectal cancer surgery as a case study. METHODS: Twenty-seven semistructured interviews were conducted with healthcare professionals between June and November 2020. A key informant sampling approach was used, followed by snowballing to achieve maximum regional variation across the UK. Data were analysed thematically using the constant comparison approach. RESULTS: In the context of considerable resource constraint, surgical teams overcame challenges to continue elective cancer provision. They achieved this by pursuing a combination of strategies: relocating surgical services; prioritizing patients within and across surgical specialties; adapting patient treatment plans; and introducing changes to surgical team working practices. Despite national guidance, prioritization decisions were framed as complex, and the most challenging of the strategies to implement, both practically and emotionally. CONCLUSION: There is a need to better support surgeons tasked with prioritizing patients when capacity exceeds demand.

Branch Retinal Vein Occlusion in a COVID-19 Positive Patient.

Retinal vein occlusions (RVOs), including central retinal vein occlusions (CRVOs) and branch retinal vein occlusions (BRVOs), are a common cause of morbidity in elderly patients. We present the case of a healthy 74-year-old female patient who initially presented with blurry vision in her left eye in the setting of a symptomatic COVID-19 infection. She was diagnosed with a branch retinal vein occlusion that did not immediately require treatment. Three months later, she again presented with worsening vision and was found to have cystoid macular edema (CME) secondary to the vein occlusion, thus was treated with an intravitreal dexamethasone implant. This case serves to highlight the growing evidence of increased thromboembolic risk associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the possible correlation of COVID-19 infections with ocular pathology, including retinal vein occlusions.

A Prospective Study to Identify Rates of SARS-CoV-2 Virus in the Peritoneum and Lower Genital Tract of Patients Having Surgery: An Observational Study.

STUDY OBJECTIVE: The risks to surgeons of carrying out aerosol-generating procedures during the coronavirus disease 2019 (COVID-19) pandemic are unknown. To start to define these risks, in a systematic manner, we investigated the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in the abdominal fluid and lower genital tract of patients undergoing surgery. DESIGN: Prospective cross-sectional observational study. SETTING: Single, large United Kingdom hospital. PATIENTS: Total of 113 patients undergoing abdominal surgery or instrumentation of the lower genital tract. INTERVENTIONS: We took COVID-19 swabs from the peritoneal cavity and from the vagina from all eligible patients. Results were stratified by preoperative COVID-19 status. MEASUREMENTS AND MAIN RESULTS: In patients who were presumed COVID-19 negative at the time of surgery, SARS-CoV-2 virus RNA was detected in 0 of 102 peritoneal samples and 0 of 98 vaginal samples. Both cohorts included 4 patients who were antibody positive but nasopharyngeal swab test negative at the time of surgery. Peritoneal and vaginal swabs were also negative in 1 patient who had a positive nasopharyngeal swab immediately before surgery. CONCLUSION: The presence of SARS-CoV-2 RNA in the abdominal fluid or lower genital tract of presumed negative patients is nil or extremely low. These data will inform surgeons of the risks of restarting laparoscopic surgery at a time when COVID-19 is endemic in the population.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery.

AIM: There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland. METHODS: Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines. RESULTS: All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management. CONCLUSION: These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

Coluber Constrictor Bite to the Eye: A Novel Case Report of a Wild Snake Bite to the Eye in North America and Review of Literature.

Snake bites involving the eye are an uncommon cause of ocular trauma; herein, we present one of the few known instances of a snake bite directly to the globe, specifically by the way of a Coluber constrictor, also known as the "Black Racer." In this case report, we describe a nine-year-old girl who presented immediately following a snake bite to the right eye. The patient's vision was unaffected despite visualized puncture wounds through the conjunctiva with associated near-total subconjunctival hemorrhage. The patient was taken to the operating room emergently for globe exploration. Circumferential peritomy and direct view to the sclera did not reveal any lacerations or puncture and subconjunctival vancomycin, gentamycin, and dexamethasone were administered intraoperatively. Post-operatively, the patient was discharged on a regimen of oral Cephalexin. Throughout multiple follow-ups, she continued to maintain excellent vision without sequelae. Trauma to the globe via snake bite is an exceedingly rare occurrence. Upon literature review, three out of three cases involving venomous snakes resulted in "No Light Perception" vision despite anti-venom. While nonvenomous snake bites may lend a better visual outcome, if not treated properly they may also yield poor final visual potential. Methods of treatment include oral or subconjunctival antibiotic administration with or without a steroid or cycloplegic agent. All reported cases of nonvenomous cases ultimately resulted in excellent visual potential (20/40 or better) and no reports of endophthalmitis. As such, it is evident that identifying the species of snake is of the utmost importance when considering visual prognosis. Due to very few reported incidences of globe trauma via snake bite, there is no mainstay therapy for either the venomous or nonvenomous snake bite variety. Despite this, we encourage careful pursuance of the appropriate therapy on a case-by-case basis, considering operative treatment, antivenom (if necessary), and antibiotic coverage with possible cycloplegia and steroid administration.

Treatment of Coats' disease: an analysis of pooled results.

AIM: To elucidate the association of treatment modality to vitreoretinal fibrosis and traction retinal detachment (TRD) in Coats' disease. METHODS: A PubMed search for Coats' disease with included studies describing eyes with clinical features and treatment course of Coats' disease. Binary logistic regression with fibrosis at presentation and treatment type as independent variables was performed to determine predictors of TRD historically (since 1921) and in the anti-vascular endothelial growth factor (VEGF) era (since 2007). Odds ratios (OR) with 95% confidence intervals (CI) reported. RESULTS: Of 175 articles described 1183 eyes. Vitreoretinal fibrosis increased from presentation (5.4%) to follow-up (15.5%) and TRD increased from 0.44% to 3.9% at follow up. Laser was protective against vitreoretinal fibrosis (OR 0.6, 95%CI 0.4-0.9) but TRD was borderline (OR 0.6, 95%CI 0.3-1.1). Cryotherapy showed a higher association with TRD (OR 1.9, 95%CI 1.0-3.7) than with vitreoretinal fibrosis (OR 0.8, 95%CI 0.5-1.2). Similarly, intravitreal anti-VEGF alone was not associated with fibrosis (OR 1.1, 95%CI 0.6-1.8) nor TRD (OR 1.1, 95%CI 0.5-2.6) but the combination of laser and anti-VEGF therapy was protective [Fibrosis: 0.1 (0.03, 0.35); TRD: 0.05 (0.01, 0.23)] compared to anti-VEGF plus cryotherapy (P<0.001). Disease stage ≤2B or ≥3A was not associated with TRD. CONCLUSION: Vitreoretinal fibrosis and TRD increase after treatment in Coats' disease. The combination of anti-VEGF agents and cryotherapy may lead to higher risk for TRD. Presence of pre-treatment fibrosis is the highest risk factor for post-treatment worsening of vitreoretinal fibrosis and TRD.

Hairpulling causing vision loss: a case report.

Subperiosteal extension of a subgaleal hematoma (SGH) to the orbit is a reported, but rare complication of trauma. This report details a 13-year-old African-American male who originally presented to the emergency department after trauma with headache and was found on CT imaging to have a contained subgaleal hemorrhage. He presented 2 days later with increased pain and proptosis of the left eye with findings of decreased visual acuity, elevated intraocular pressure, proptosis, and complete external ophthalmoplegia. Repeat imaging revealed enlargement of the SGH with subperiosteal extension into the left orbit. He required an emergent lateral canthotomy with inferior and superior cantholysis, followed by surgical drainage of the subperiosteal and SGH. Hematologic workup for coagulopathy was negative. The authors urge point-of-care providers to consider ophthalmic evaluation for patients with large SGHs where orbital extension and vision loss may occur. Furthermore, SGH causing orbital compartment syndrome may develop in patients who have normal blood work and clotting factors.

Effect of Tissue Factor on Colorectal Cancer Stem Cells.

BACKGROUND/AIM: Tissue factor (TF) expression increases cancer stem cell (CSC) activity in breast and lung cancer. There are ongoing studies focused on targeting CSCs via anti-TF treatment, for breast and lung cancer therapy. Herein, the aim was to determine whether targeting TF could have an anti-CSC therapeutic role in colorectal cancer (CRC). MATERIALS AND METHODS: Evaluation of colonosphere-forming efficiency (CFE) and aldehyde dehydrogenase (ALDH) expression level was used to quantify CSC activity in two CRC cell lines, after TF knockdown (TFKD) or TF over-expression (TFOE). RESULTS: TFKD resulted in increased levels of ALDH in SW620 (1.31±0.04-fold, p<0.001) and DLD-1 (1.63±0.14-fold, p=0.04) cells. CFE was increased in SW620 (1.21±0.23% vs. 2.03±0.29%, p=0.01) and DLD-1 (0.41±0.12% vs. 0.68±0.9%, p=0.01) cells. Conversely, TFOE decreased ALDH expression (0.72±0.04-fold, p=0.001) and CFE (0.33±0.05% vs. 0.66±0.14%, p=0.006) in DLD-1, but had no impact on SW620 cells. CONCLUSION: In the examined CRC cell lines, TF expression was inversely related to CSC activity suggesting that anti-TF therapies may not have a role in CRC treatment.

Vascular endothelial growth factors and receptors in colorectal cancer: implications for anti-angiogenic therapy.

There are conflicting associations between growth factor expression and clinicopathological variables in colorectal cancer. This study aimed to define the expression of members of the VEGF family and the receptor, VEGFR2, in primary and metastatic sites of colorectal cancer and their relationship to metastatic potential. Thirty colorectal cancers, 12 lymph node metastases and 9 liver metastases were immunostained for VEGF-A, VEGF-C, VEGF-D and VEGFR2. VEGFR2 was expressed by endothelial cells and by the malignant epithelium. VEGF-C and VEGFR2 were co-expressed in the same territory and correlated throughout the primary tumour and in metastatic lymph nodes, but not in liver metastases. Their expression at the invasive tumour edge correlated with expression in metastatic nodes. The benefit of anti-VEGF antibodies might be increased by directing additional therapies against VEGF-C or against the kinase receptors to target redundancy in the system. A component of the therapeutic benefit might be due to a direct anti-tumour effect as well as an anti-angiogenic effect.

Perfusion of 99Tcm-labeled CD105 Mab into kidneys from patients with renal carcinoma suggests that CD105 is a promising vascular target.

There is strong published and unpublished evidence that our CD105 Mab E9, which is highly reactive with angiogenic endothelial cells, could be a useful reagent to target the vasculature of solid tumors in man. Since Mab E9 does not cross-react with animal tissues, we undertook here to evaluate its localization using human kidney as an ex vivo model. Perfusion was performed through the renal artery of 99Tcm-labeled purified CD105 Mab in freshly excised kidneys from 7 patients with renal carcinoma. In all 7 cases, immunoscintigraphs showed the presence of well-defined radioactive hot spots, which matched the positions of the tumors as identified by presurgery MRI scans and subsequent histopathologic examination. Importantly, in one instance, where a presurgery MRI scan had identified only one tumor, immunoscintigraphs showed 2 distinct hot spots of radioactivity. The pathology report confirmed that the additional hot spot corresponded to a small secondary well-vascularized tumor. The implication of this finding is that the radiolabeled Mab, E9, may be of use in the detection of metastatic disease. That the labeling of tumors was specific was confirmed when prior perfusion of unlabeled mab E9 in 2 kidneys completely blocked the localization of 99Tcm-conjugated Mab E9. Radioactivity in samples of tumor and normal tissue taken from 7 kidneys was counted in a gamma counter. In all cases, there was a greater uptake of radioactivity in tumors compared with the corresponding normal kidneys. The median values, adjusted per gram wet weight, for 99Tcm were 14.8 times (range, 4.8-113.0) greater in kidney tumors than in normal kidney tissue (p < 0.007). Immunofluorescent staining of cryostat sections of tumor tissues in each of the 7 cases showed strong and uniform localization of Mab E9 in tumor microvessels. Interestingly, chimeric staining of endothelial cells (ECs) was seen in an occasional microvessel segment. That is, while most of the ECs lining a microvessel were strongly stained, an occasional EC was negative. This was not an artifact of staining. Unstained ECs may be nonangiogenic or apoptotic since CD105 is a proliferation/activation-associated antigen. Further investigations are warranted to establish the pharmacokinetics of 99Tcm-labeled CD105 antibody in vivo. This would enable us to determine whether an apparently highly successful ex vivo study has the potential for tumor imaging/therapeutic vascular targeting in patients with cancer.

CD105 is important for angiogenesis: evidence and potential applications.

Angiogenesis is the propelling force for tumor growth and metastasis, and antiangiogenic therapy represents one of the most promising modalities for cancer treatment. CD105 (endoglin) is a proliferation-associated and hypoxia-inducible protein abundantly expressed in angiogenic endothelial cells (EC). It is a receptor for transforming growth factor (TGF) -beta1 and -beta3 and modulates TGF-beta signaling by interacting with TGF-beta receptors I and/or II. Immunohistochemistry studies have revealed that CD105 is strongly expressed in blood vessels of tumor tissues. Intratumoral microvessel density (MVD) determined using antibodies to CD105 has been found to be an independent prognostic indicator, wherein increased MVD correlates with shorter survival. CD105 is able to be shed into the circulation, with elevated levels detected in patients with various types of cancer and positively correlated with tumor metastasis. Tangible evidence of its proangiogenic role comes from knockout studies in which CD105 null mice die in utero as a result of impaired angiogenesis in the yolk sac and heart defects. The potential usefulness of CD105 for tumor imaging has been evaluated in tumor-bearing mice and dogs that have shown the rapid accumulation of radiolabeled anti-CD105 monoclonal antibody in the tumors with a high tumor-to-background ratio. The anti-CD105 antibody conjugated with immunotoxins and immunoradioisotopes efficiently suppressed/abrogated tumor growth in murine models bearing breast and colon carcinoma without any significant systemic side effects. Immunoscintigraphy in patients with renal cell carcinomas has shown specific localization of 99Tcm-labeled CD105 mab in tumor endothelial cells. Thus, CD105 is a promising vascular target that can be used for tumor imaging, prognosis, and bears therapeutic potential in patients with solid tumors and other angiogenic diseases.