The effect of oral anticoagulation on the prevalence and management of haematuria in a contemporary Australian patient cohort.

OBJECTIVE: • To examine the effect of oral anticoagulation (OA) on the prevalence and inpatient management of haematuria in a contemporary Australian patient cohort. PATIENTS AND METHODS: • Patients across all inpatient units who had diagnosis-related group (DRG) coding for haematuria were identified from April 2010 to September 2011. • A retrospective chart review was performed to identify the type of anticoagulation (if any), requirement for bladder irrigation or blood transfusion, length of stay (LOS) and cause of haematuria. • Patients for whom the anticoagulation status was uncertain were excluded from analysis. • Statistical significance was determined by Pearson's chi-square tests and Student's t-tests. RESULTS: • In all, 335 admissions with DRG coding for haematuria were identified from hospital records, of which 268 admissions had clear documentation of anticoagulation. There were 118 emergency admissions and 150 elective admissions for day case cystoscopy. The mean age of the patients was 66 years and the male:female ratio was 5:1. In all, 123 admissions were for patients on some form of anticoagulation (46%). • Patients were on anticoagulation in 53% of the 118 emergency admissions for gross haematuria. These comprised patients on aspirin (28%), clopidogrel (4%), warfarin (10%), combined aspirin and warfarin (1%) and combined aspirin and clopidogrel (10%). • The use of OA was a significant predictor of the need for intervention among the 118 emergency admissions (86% vs 62%, P = 0.003). • In particular, dual antiplatelet therapy in the form of aspirin and clopidogrel was associated with an increased requirement for bladder irrigation (92%) when compared with patients on other forms of anticoagulation (84%) or none at all (62%, P = 0.01). • The mean LOS for patients admitted to hospital with haematuria was 5.6 days. Patients on warfarin had a statistically significant longer LOS than the other groups (13.7 vs 4.5 days, P < 0.001). A cause for haematuria was identified in 120 of the 234 patients (51%). Of these, the most common was benign prostatic hyperplasia (21%), followed by bladder urothelial carcinoma (17%). CONCLUSION: • In our cohort of patients, about half of all admissions with haematuria were for patients on some form of OA. • OA use increased the need for intervention, especially for patients on dual antiplatelet therapy.

In vitro and in vivo evaluation of tumor targeting styrene-maleic acid copolymer-pirarubicin micelles: Survival improvement and inhibition of liver metastases.

Pirarubicin is a derivative of doxorubicin with improved intracellular uptake and reduced cardiotoxicity. We have prepared a micellar formulation of pirarubicin using styrene-maleic acid copolymer (SMA) of mean molecular weight of 1.2 kDa, which exhibits a mean diameter of 248 nm in solution. Being a macromolecule, SMA-pirarubicin micelles exhibit excellent tumor targeting capacity due to the enhanced permeability and retention (EPR) effect. Here we report the antitumor activity of SMA-pirarubicin micelles on human colon and breast cancer cell lines in vitro, and a murine liver metastasis model in vivo. Metastatic tumor microvasculature, necrosis, apoptosis, proliferation, and survival were also investigated using immunohistochemistry for Ki-67, active caspase-3, and CD34, respectively. Drug cytotoxicity in vitro was assessed using MTT (3-[4,5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide) assay. In vivo, SMA-pirarubicin was administered at 100, 150, or 200 mg/kg (pirarubicin equivalent). Tumor microvasculature was also assessed using scanning electron microscopy. Styrene-maleic acid copolymer (SMA)-pirarubicin micelles were toxic against human colorectal and breast cancer cells in vitro. IC(50) was at or below 1 muM, free pirarubicin equivalent. In vivo, SMA-pirarubicin at 100 mg/kg reduced tumor volume by 80% and achieved a survival rate of 93% at 40 days after tumor inoculation. Styrene-maleic acid copolymer (SMA)-pirarubicin micelles demonstrated potent antitumor activity in this liver metastases model, contributing to prolonged survival. Histological examination of tumor nodules showed significant reduction and proliferation of tumor cells (>90%). The present results suggest that investigation of the effect of multiple dosing at later time points to further improve survival is warranted.

Styrene maleic acid-pirarubicin disrupts tumor microcirculation and enhances the permeability of colorectal liver metastases.

BACKGROUND: Doxorubicin is a commonly used chemotherapy limited by cardiotoxicity. Pirarubicin, derived from doxorubicin, selectively targets tumors when encapsulated in styrene maleic acid (SMA), forming the macromolecular SMA pirarubicin. Selective targeting is achieved because of the enhanced permeability and retention (EPR) effect. SMA-pirarubicin inhibits the growth of colorectal liver metastases, but tumor destruction is incomplete. The role played by the tumor microcirculation is uncertain. This study investigates the pattern of microcirculatory changes following SMA-pirarubicin treatment. METHODS: Liver metastases were induced in CBA mice using a murine-derived colon cancer line. SMA-pirarubicin (100 mg/kg total dose) was administered intravenously in 3 separate doses. Twenty-four hours after chemotherapy, the tumor microvasculature was examined using CD34 immunohistochemistry and scanning electron microscopy. Tumor perfusion and permeability were assessed using confocal in vivo microscopy and the Evans blue method. RESULTS: SMA-pirarubicin reduced the microvascular index by 40%. Vascular occlusion and necrosis were extensive following treatment. Viable cells were arranged around tumor vessels. Tumor permeability was also increased. CONCLUSION: SMA-pirarubicin damages tumor cells and the tumor microvasculature and enhances tumor vessel permeability. However, tumor necrosis is incomplete, and the growth of residual cells is sustained by a microvascular network. Combined therapy with a vascular targeting agent may affect residual cells, allowing more extensive destruction of tumors.

Evaluation of the effect of SMA-pirarubicin micelles on colorectal cancer liver metastases and of hyperbaric oxygen in CBA mice.

Tetrahydropyranyladriamycin (THP or pirarubicin) destroys tumors via several mechanisms; one of which involves the production of ROS that requires molecular oxygen for its generation. SMA forms stable self-assembled associated micelles with pirarubicin (SMA-pirarubicin), and confers macromolecular characteristics to pirarubicin. This micellar macromolecular drug is selectively delivered to solid tumors via the EPR effect and its preferential tumor accumulation suppresses the systemic toxicity whilst its prolonged high concentration at the site of tumor enhances its efficacy much higher compared to free pirarubicin. Administration of SMA-pirarubicin micelle under HBO can further enhance the delivery of molecular oxygen that facilitates tumor selective generation of ROS, thus augmenting its antitumor potency. In this study, we evaluated the efficacy of SMA-pirarubicin micelles either as single drug or in combination with HBO in a mouse metastatic colorectal cancer model. At or below the maximum tolerated dose, SMA-pirarubicin remarkably reduced metastatic tumor nodules and it was far more effective than free pirarubicin. The data also suggests a potential benefit of combined therapy of HBO with micellar anthracyclins.

Laparoscopic or open appendicectomy for suspected appendicitis in pregnancy and evaluation of foetal outcome in Australia.

BACKGROUND: Recent data suggest that laparoscopic appendicectomy (LA) in pregnancy is associated with higher rates of foetal loss when compared to open appendicectomy (OA). However, the influence of gestational age and maternal age, both recognized risk factors for foetal loss, was not assessed. METHOD: This was a multicentre retrospective review of all pregnant patients who underwent appendicectomy for suspected appendicitis from 2000 to 2012 across seven hospitals in Australia. Perioperative data and foetal outcome were evaluated. RESULTS: Data on 218 patients from the seven hospitals were included in the analysis. A total of 125 underwent LA and 93 OA. There were seven (5.6%) foetal losses in the LA group, six of which occurred in the first trimester, and none in the OA group. After matching using propensity scores, the estimated risk difference was 5.1% (95% confidence interval (CI): 1.4%, 9.8%). First trimester patients were more likely to undergo LA (84%), while those in the third were more likely to undergo OA (85%). Preterm delivery rates (6.8% LA versus 8.6% OA; CI: -12.6%, 5.3%) and hospital length of stay (3.7 days LA versus 4.5 days OA; CI: -1.3, 0.2 days) were similar. CONCLUSION: This is the largest published dataset investigating the outcome after LA versus OA while adjusting for gestational and maternal age. OA appears to be a safer approach for pregnant patients with suspected appendicitis.

The effect of hyperbaric oxygen therapy on tumour growth in a mouse model of colorectal cancer liver metastases.

BACKGROUND AND AIMS: Hyperbaric oxygen (HBO) therapy involves the administration of 100% oxygen at high pressure. It has been used to treat a variety of conditions including non-healing wounds, carbon monoxide poisoning, and as an adjuvant to radiotherapy or chemotherapy. The effect of HBO alone on the growth of malignancy remains controversial. This study investigates the impact of HBO on tumour growth, kinetics and microcirculation of colorectal cancer liver metastases in an experimental model. METHODS: Male CBA mice were induced with colorectal liver metastases via an intrasplenic injection of a murine derived colorectal cell line. Tumours were examined using quantitative stereological analysis, histology and scanning electron microscopy of microvascular resin casts. The effect of HBO on tumour proliferation and apoptosis was quantified using immunohistochemistry. RESULTS: Daily exposure to HBO at 2.4 atm for 90 min had no effect on the volume of liver metastases. At day 13, HBO caused a significant reduction in tumour necrosis and proliferation compared to the non-HBO group (p=0.002 and p=0.008, respectively). By day 25 however, no differences were observed (p>0.05). No differences in apoptosis or microvascular architecture were observed. CONCLUSION: HBO did not have a tumour stimulatory effect on colorectal liver metastases and may potentially be used safely in conjunction with other therapeutic treatment modalities.

Ectopic intravagal parathyroid adenoma.

BACKGROUND: Intraneural parathyroid adenomas are rare, with only 9 cases of intravagal adenomas reported. All but one of the reported cases was found after multiple neck explorations. To the best of our knowledge, we report the first case of nonsupernumerary ectopic intravagal parathyroid identified at primary exploration. METHODS AND RESULTS: A 17-year-old girl with primary hyperparathyroidism and nephrolithiasis was referred with a sestamibi scan reporting a left lower parathyroid adenoma. No eutopic parathyroid tissue was identified during full exploration of the left side of the neck. Exploration of the carotid sheath revealed a fusiform swelling of the vagus nerve at the level of the carotid bifurcation. Longitudinal incision of the vagal perineurium revealed a 7-mm parathyroid adenoma, which was enucleated. The patient recovered uneventfully, with normalization of serum calcium, parathyroid hormone (PTH), and normal vocal cord function. CONCLUSION: We believe that this is the first reported case of nonsupernumerary intravagal parathyroid adenoma resected at initial exploration. The vagus nerve is a rare location for a parathyroid adenoma, but one that should be considered, even during primary exploration.

Styrene maleic acid copolymer-pirarubicin induces tumor-selective oxidative stress and decreases tumor hypoxia as possible treatment of colorectal cancer liver metastases.

BACKGROUND: Pirarubicin, a derivative of doxorubicin, induces tumor destruction via the production of reactive oxygen species (ROS) but is associated with cardiotoxicity. As a macromolecule (conjugated to styrene-maleic acid [SMA]), SMA-pirarubicin is selective to tumors resulting in improved survival with decreased systemic toxicity. Tumor destruction is, however incomplete, and resistant cells at the periphery of the tumor contribute to recurrence. Tumor hypoxia is a major factor in tumor resistance. Understanding the effect of oxidative stress induced by SMA-pirarubicin on the tumor microenvironment may be key to overcoming resistance. This study investigated the pattern of ROS production and tumor hypoxia after treatment with SMA-pirarubicin in a murine model of colorectal liver metastases. METHODS: Liver metastases were induced in male, CBA mice using a murine-derived colon cancer cell line. SMA-pirarubicin (maximum tolerated dose, 100 mg/kg) or pirarubicin, (maximum tolerated dose, 10 mg/kg) were administered intravenously 14 days after tumor induction. Systemic oxidative stress in serum, liver, and cardiac tissue was quantified using the thiobarbituric acid reactive substances assay. Flow cytometry and fluorescence microscopy were used to assess ROS production for 48 hours after treatment. Tumor hypoxia was quantified using immunohistochemistry for pimonidazole adducts. RESULTS: SMA-pirarubicin (100 mg/kg) induced ROS exclusively in tumors with minimal levels in serum and cardiac tissue. ROS levels were induced in a time-dependent and dose-dependent manner optimal between 4 and 24 hours after drug administration. Although tumor hypoxia was decreased overall, residual tumor cells adjacent to patent vessels were hypoxic. CONCLUSION: This study provides insight into the tumor microenvironment after chemotherapy. SMA-pirarubicin inhibits the growth of colorectal liver metastases by inducing ROS, which seems to be largely tumor selective. The temporal pattern of ROS production can be used to improve future dosing regimens. Furthermore, the observation that residual tumor cells are hypoxic clarifies the need for a multimodal approach with agents that can alter the hypoxic state to effect complete tumor destruction.

A model of partial hepatectomy in mice.

A versatile, simple, and reproducible model of hepatectomy is essential for the study of liver regeneration and its effects on various pathological processes. A murine model of liver resection and regeneration suitable for research is described. Male inbred CBA mice 6-8 wk old were used in all experiments. The contribution of the hepatic lobes to the total liver mass was determined by wet weight measurements. Resection of 37% (n = 10) and 70% (n = 10) liver volume was performed using hemostatic clips to ligate the hepatic lobe pedicles. Animals were recovered and subsequently killed 21 days postoperatively Liver mass was determined and compared to control animals (n = 17) to assess the completeness of liver regeneration. There were no operative deaths in animals undergoing either 37% or 70% hepatectomy. The procedures could be performed expediently, and animal recovery was complete. Liver mass (grams) assessed 21 days postoperatively [mean (SE)] in both the 37% resection, 1.76 g (0.07), and 70% resection, 1.56 g (0.05), groups was not significantly different from control animals, 1.64 g (0.07) (p =.265). Thus, partial hepatectomy can be performed safely and rapidly in mice using haemostatic clip ligation of hepatic lobes, with no impairment to the subsequent process of liver regeneration.

Effect of fatigue on laparoscopic skills: a comparative historical cohort study.

BACKGROUND: Fatigue has been shown to have a negative impact on surgical performance. However, there is a lack of research investigating its effect on laparoscopy, particularly in Australia. This study investigated whether fatigue associated with a surgeon's usual workday led to a measurable drop off in laparoscopic surgical skills as assessed on a laparoscopic simulator. METHODS: A comparative study involving two cohorts was undertaken: a study group whose data were collected prospectively was compared to a historical control group. Participants were required to reach a predetermined level of proficiency in each laparoscopic task on either a FLS or LapSim simulator. The participants in the study cohort were re-tested approximately 1 month after completing 10 h of work. The participants in the historical non-fatigued group were re-tested approximately 1 month after reaching proficiency. Comparisons between cohorts were made using a 'decrease in score per day elapsed' value to account for the natural attrition in skills over time and the variability in testing times within and between the two cohorts. RESULTS: The decrease in overall score per day elapsed for fatigued participants was significantly greater than for historical non-fatigued participants, irrespective of the simulator type. Fatigue had a greater impact on certain laparoscopic skills, including peg transfer and knot tying. Participants who self-reported higher level of fatigue demonstrated significantly better skills than those who self-reported lower levels. CONCLUSION: Overall laparoscopic skill proficiency was reduced in the fatigued participants compared to the historical non-fatigued participants, with certain laparoscopic skills more affected than others.

Treatment with the vascular disruptive agent OXi4503 induces an immediate and widespread epithelial to mesenchymal transition in the surviving tumor.

Epithelial to mesenchymal transition (EMT) is considered an important mechanism in tumor resistance to drug treatments; however, in vivo observation of this process has been limited. In this study we demonstrated an immediate and widespread EMT involving all surviving tumor cells following treatment of a mouse model of colorectal liver metastases with the vascular disruptive agent OXi4503. EMT was characterized by significant downregulation of E-cadherin, relocation and nuclear accumulation of ß-catenin as well as significant upregulation of ZEB1 and vimentin. Concomitantly, significant temporal upregulation in hypoxia and the pro-angiogenic growth factors hypoxia-inducible factor 1-alpha, hepatocyte growth factor, vascular endothelial growth factor and transforming growth factor-beta were seen within the surviving tumor. The process of EMT was transient and by 5 days after treatment tumor cell reversion to epithelial morphology was evident. This reversal, termed mesenchymal to epithelial transition (MET) is a process implicated in the development of new metastases but has not been observed in vivo histologically. Similar EMT changes were observed in response to other antitumor treatments including chemotherapy, thermal ablation, and antiangiogenic treatments in our mouse colorectal metastasis model and in a murine orthotopic breast cancer model after OXi4503 treatment. These results suggest that EMT may be an early mechanism adopted by tumors in response to injury and hypoxic stress, such that inhibition of EMT in combination with other therapies could play a significant role in future cancer therapy.

Selective targeting of the tumour vasculature.

Selective targeting of the tumour vasculature in the treatment of solid organ malignancies is an alternative to conventional chemotherapy treatment. As the tumour progressively increases in size, angiogenesis or the formation of new vasculature is essential to maintain the tumour's continual growth and survival. Therefore disrupting this angiogenic process or targeting the neovasculature can potentially hinder or prevent further tumour expansion. Many anti angiogenic agents have been investigated with many currently in clinical trials and exhibiting varied results. Vascular disrupting agents such as the Combretastatins and OXi 4503 have shown promising preclinical results and are currently being examined in clinical trials.

Hyperbaric oxygen therapy for malignancy: a review.

One unique feature of tumors is the presence of hypoxic regions, which occur predominantly at the tumor center. Hypoxia has a major impact on various aspects of tumor cell function and proliferation. Hypoxic tumor cells are relatively insensitive to conventional therapy owing to cellular adaptations effected by the hypoxic microenvironment. Recent efforts have aimed to alter the hypoxic state and to reverse these adaptations to improve treatment outcome. One way to increase tumor oxygen tensions is by hyperbaric oxygen (HBO) therapy. HBO therapy can influence the tumor microenvironment at several levels. It can alter tumor hypoxia, a potent stimulus that drives angiogenesis. Hyperoxia as a result of HBO also produces reactive oxygen species, which can damage tumors by inducing excessive oxidative stress. This review outlines the importance of oxygen to tumors and the mechanisms by which tumors survive under hypoxic conditions. It also presents data from both experimental and clinical studies for the effect of HBO on malignancy.

Effect of thalidomide on colorectal cancer liver metastases in CBA mice.

BACKGROUND AND AIMS: Thalidomide has undergone resurgence in the treatment of specific malignancies. One of the possible actions of thalidomide may be an antiangiogenic effect. This study investigates the effects of thalidomide on tumor growth and long-term survival in a murine model of colorectal liver metastases. METHODS: Liver metastases were produced in male CBA mice by intrasplenic injection of a dimethyl hydrazine induced MoCR colon cancer murine cell line. Thalidomide was administered daily at doses ranging from 50 to 300 mg/kg by intraperitoneal injection. Tumor growth was assessed using quantitative stereological analysis. The effect on long-term survival was determined at the maximum tolerated dose using Kaplan-Meier analysis. The microvascular effects of thalidomide were assessed by laser Doppler flowmetry (LDF) and microvascular resin casting. Immunohistochemistry was used to determine vascular endothelial growth factor (VGEF) and basic fibroblast growth factor (bFGF) expression. RESULTS: Thalidomide, (50-300 mg/kg) caused no significant reduction in tumor growth by day 21 following induction of liver metastases and caused systemic toxicity at a dose of 300 mg/kg. At a dose of 200 mg/kg given beyond 35 days, thalidomide significantly reduced tumor growth compared to control, (P = 0.029). No significant impact on survival was however observed (P = 0.93). LDF and microvascular resin casting showed no differences in blood flow or tumor microvascular architecture. VGEF and FGF were expressed in tumors, but remained unaltered by thalidomide administration compared to matched controls. CONCLUSIONS: Thalidomide caused a significant reduction in the volume of colorectal liver metastases during the late phase of tumor growth. There was however no improvement in survival. Tumor growth reduction in this model did not appear to be due to microvascular changes or altered expression of VGEF or basic FGF. Further investigation into potential mechanisms of action of thalidomide and its synergistic use with other therapies is required.