Hyperbaric oxygen improves capillary morphology in severe acute pancreatitis.

Objectives: This article aims to determine the effect of acute pancreatitis on microvascular morphology and the impact of treatment with hyperbaric oxygen (HBO).

Methods: Sixty-seven male Wistar rats were induced with acute pancreatitis by retrograde bile duct injection. Rats were randomized to 12-hourly HBO or control treatment.

Liver regeneration and tumor stimulation--a review of cytokine and angiogenic factors.

Liver resection for metastatic (colorectal carcinoma) tumors is often followed by a significant incidence of tumor recurrence. Cellular and molecular changes resulting from hepatectomy and the subsequent liver regeneration process may influence the kinetics of tumor growth and contribute to recurrence. Clinical and experimental evidence suggests that factors involved in liver regeneration may also stimulate the growth of occult tumors and the reactivation of dormant micrometastases.

Vaccination with in vitro grown whole tumor cells induces strong immune responses and retards tumor growth in a murine model of colorectal liver metastases.

In vitro adaptation of a murine colorectal cell line (MoCR) rendered it less aggressive and more immunogenic than the in vivo passaged parent tumor. Vaccination of syngeneic mice with the in vitro cultured tumor cells was shown to induce immune responses and protection against tumor challenge, thus overcoming the need for antigen selection and adjuvants. A syngeneic murine model of colorectal cancer (CRC) liver metastasis was used.

Alterations in vascular architecture and permeability following OXi4503 treatment.

OXi4503 retards tumor growth in a dose-dependent manner and improves survival in a murine model of colorectal liver metastases. This agent causes extensive vascular shutdown by selectively altering the tubulin cytoskeleton within the endothelial cells of tumor vessels. The destruction of tumor vessels is incomplete, however, and tumor revascularization occurs after the treatment.

Hyperbaric oxygen therapy for severe acute pancreatitis.

Despite improvements in the supportive management of severe acute pancreatitis over the last decade, the morbidity and mortality rate remains high. The main feature of this condition is pancreatic necrosis leading to sepsis, with both localized and systemic inflammatory response syndromes. Early pathophysiological changes of the pancreas include alterations in microcirculation, ischemia reperfusion injury, and leukocyte and cytokine activation.

Effect of vascular targeting agent Oxi4503 on tumor cell kinetics in a mouse model of colorectal liver metastasis.

Background: Oxi4503 has been shown to inhibit tumor growth and improve survival in an animal model of colorectal (CRC) liver metastases. This agent appears to selectively target the endothelial cytoskeleton with resultant vessel occlusion and tumor necrosis.

Materials And Methods: This study evaluated the pattern of tumor necrosis caused by Oxi4503, with particular emphasis on patterns of cell proliferation and apoptosis in a murine model of CRC liver metastases.

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.

Hyperbaric oxygen therapy reduces severity and improves survival in severe acute pancreatitis.

Severe acute pancreatitis is characterized by pancreatic necrosis, resulting in local and systemic inflammation. Hyperbaric oxygen (HBO) therapy modulates inflammation, but has not been extensively studied in pancreatitis. This study investigates the effects of HBO in a rat model of severe acute pancreatitis.

Hematopoietic toxicity from lead-containing Ayurvedic medications.

Background: Millions worldwide use Ayurvedic (traditional Indian) medicines. These medications are increasingly associated with lead poisoning, often accompanied by anemia. We compared the relative hematopoietic toxicity of Ayurvedic lead poisoning with a common form of occupational lead poisoning.

Vascular targeting agent Oxi4503 inhibits tumor growth in a colorectal liver metastases model.

Background And Aim: Oxi4503 is a potent vascular targeting agent belonging to the family of combretastatins. These agents produce an acute reduction in tumor blood flow leading to tumor necrosis. Despite evidence of its efficacy in certain malignancies, the effect on colorectal liver metastases remains largely unknown.

Factors associated with diabetes onset during metformin versus placebo therapy in the diabetes prevention program.

In the Diabetes Prevention Program, treatment of subjects with impaired glucose tolerance with metformin >3.2 years reduced the risk of developing type 2 diabetes by 30% compared with placebo. This study describes the mechanisms of this effect.

Emergency duties and deaths from heart disease among firefighters in the United States.

Background: Heart disease causes 45% of the deaths that occur among U.S. firefighters while they are on duty.

Effect of ACE inhibitors and angiotensin II receptor antagonists in a mouse model of colorectal cancer liver metastases.

Background And Aims: Angiotensin converting enzyme inhibitors (ACE-I) and angiotensin II type I receptor (AT1R) antagonists are commonly used as a treatment for hypertension. Recent experimental and population studies have suggested that these agents may exert an inhibitory effect on malignancy, possibly through anti-angiogenic pathways. The aim of this study was to investigate the effect of an ACE-I (captopril) and an AT1R antagonist (irbesartan) in colorectal cancer liver metastases.

Liver regeneration stimulates tumor metastases.

Background: Partial hepatectomy for patients with colorectal liver metastases is associated with a tumor recurrence rate approaching 80% post-resection. Different factors and phases associated with regeneration of the liver are implicated in tumor recurrence. This study investigates the effects of the early and late phases of liver regeneration and the impact of the degree of liver resection on stimulating tumor growth and metastasis.

Risk factors for liver transplantation waiting list mortality.

Background And Aim: The gap between the demand for liver transplantation and organ donation rates has a major impact on waiting list mortality. Understanding the risk factors that predict liver transplant waiting list death may help optimize organ allocation policy and reduce waiting list deaths.

Methods: We analyzed risk factors associated with waiting list mortality in the Liver Transplant Unit Victoria for the period 1988 through 2004.

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.

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.

Potential effects of hyperbaric oxygen therapy in acute pancreatitis.

Background: To extract from the biomedical published reports, the effects of hyperbaric oxygen (HBO) on inflammatory disease, in particular acute pancreatitis.

Methods: This review will explain these effects and evaluate potential mechanisms of action of HBO in acute pancreatitis. A Medline/PubMed search (January 1966 to July 2004) with manual cross-referencing was conducted, including all relevant articles investigating the molecular and systemic effects of HBO on inflammatory diseases, particularly focusing on the studies of acute pancreatitis.

Disturbances of the microcirculation in acute pancreatitis.

Background: Severe acute pancreatitis is characterized by pancreatic necrosis, resulting in local and systemic inflammation. Pancreatitis affects both the systemic and pancreatic vasculature. This review focuses on the underlying processes involved in the changes of microvascular anatomy following acute pancreatitis.

Impact of blood flow occlusion on liver necrosis following thermal ablation.

Background: Laser, radiofrequency and microwave are common techniques for local destruction of liver tumours by thermal ablation. The main limitation of thermal ablation treatment is the volume of necrosis that can be achieved. Blood flow occlusion is commonly advocated as an adjunct to thermal ablation to increase the volume of tissue necrosis based on macroscopic and histological assessment of immediate or direct thermal injury.

Retroperitoneal lymphangioma.

Lymphangiomas are rare cystic tumours that may present as cystic masses in the retroperitoneum. Retroperitoneal lymphangiomas account for approximately 1% of all lymphangiomas. Confusion with other cystic tumours of the retroperitoneum including those arising from the liver, kidney and pancreas is common.

Altered growth patterns of colorectal liver metastases after thermal ablation.

Background: Thermal ablation by radiofrequency or laser is used increasingly for the treatment of colorectal liver metastases. Recurrence after thermal ablation is common and occurs both locally and at distant sites. One possible cause of this recurrence may be a result of growth stimulation of micrometastases in the remaining liver.

Mechanisms of focal heat destruction of liver tumors.

Background: Focal heat destruction has emerged as an effective treatment strategy in selected patients with malignant liver tumors. Radiofrequency ablation, interstitial laser thermotherapy, and microwave treatment are currently the most widely applied thermal ablative techniques. A major limitation of these therapies is incomplete tumor destruction and overall high recurrences.