Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have developed an isolated perfused tumor model to study the metabolism of solid tumors by nuclear magnetic resonance spectroscopy. Morris hepatomas (7777) were implanted in the inguinal region of Buffalo rats, such that they developed an isolated blood supply. These tumors were perfused with a RBC perfusate, removed from the animal, and studied by 31P nuclear magnetic resonance spectroscopy. ATP levels, as determined from the spectra, were stable for as long as the tumors were maintained in the magnet (7 h) only if the perfusate contained inosine, adenosine, and insulin. The adenosine and inosine were also required for recovery from ischemia. Under these conditions, ischemia did not result in a change in tumor pH. The gamma nucleoside triphosphate resonance was significantly larger than the beta nucleoside triphosphate resonance in spectra of some of the perfused tumors, suggesting that ADP above about 300 nmol/g wet weight was not complexed in these tumors. The adenylate levels determined from extracts, O2 consumption, histology, and 31P nuclear magnetic resonance spectra of extracts of perfused tumors and tumors in situ were all similar, indicating the perfused tumor is a reasonable model of the tumor in vivo.
Cancer Res 1991 Feb 01
PMID:An ex vivo model for the study of tumor metabolism by nuclear magnetic resonance: characterization of the phosphorus-31 spectrum of the isolated perfused Morris hepatoma 7777. 198 24

Oxygen derived free radicals (OFR) arise in the course of normal cellular life, especially during cellular respiration. They are formed when molecular oxygen is reduced to water. These highly reactive species are controlled by a protective system both enzymatic and non enzymatic which helps to prevent the accumulation of peroxidative damage to the cell. Lipid peroxides result from the reaction of oxygen derived free radicals with polyinsatured fatty acids of membranes phospholipids and can be formed both non enzymatically and enzymatically (eicosanoids). Oxygen derived free radicals attack over-running beyond the protective system leads to oxidative stress. The cells involved in inflammation (polymorphonuclear, leucocytes, monocytes, platelets, endothelial cells) release oxygen derived free radicals and lipid peroxides and inflammatory diseases of infectious or non infectious origin can be considered as oxidative stress. Intracellular oxidative stress can lead to cellular death or trigger a strong inflammatory reaction. This occurs during ischemia reperfusion injury and hyperoxia. Exposure to ionizing radiation results in overproduction of oxygen derived free radicals both extra and intracellular. Oxidative stress may be involved in atheroma (where oxidised LDL are described), ageing and cancer.
 ...
PMID:[Free radicals and lipid peroxidation in cell biology: physiopathologic prospects]. 206 58

Arterial tumor embolism is a rare occurrence. We report such an embolus causing acute limb ischemia which was the first indication of malignancy in a patient who subsequently proved to have malignant melanoma.
 ...
PMID:Acute limb ischemia due to arterial embolism of tumor. 212 95

Better, noninvasive, diagnostics, better knowledge of anatomy and of surgical techniques have been responsible for a considerable development of liver surgery during recent years. Primary malignant liver tumours can only be cured by resection. The decision for resectional surgery should be based on different tumor characteristics, of whom the nature of the liver tissue (normal or cirrhotic) in which the tumor develops in of utmost importance. A malignant tumor should be resected with save, tumor-free margins, leaving behind as much normal functional parenchyma as possible. The role of complementary therapies as e.g. chemotherapy, chemo-embolisation and arterial ischemia must be further developed. Liver transplantation will probably play a more important role in the future development of liver cancer treatment. Surgery for benign liver tumors can be restricted most of the time to a limited resection; extended hepatectomies are rarely necessary. The more deliberate use of intraoperative ultrasound and hepatic vascular exclusion as well as the more frequent use of ultrasound dissectors will allow safer liver surgery; this applies especially for the excision of benign solid liver tumors. Because of their degenerative risks, liver adenomas should be excised. Focal nodular hyperplasia and haemangioma remain rare indications for surgery. The low morbidity and mortality of elective liver resections should favour a more widespread use of surgery for the treatment of malignant as well benign liver tumors.
 ...
PMID:[Surgery of benign and malignant primary liver tumors]. 217 70

The authors have measured the magnetic field dependence of 1/T1 (nuclear magnetic relaxation dispersion, or NMRD profiles) of water protons of histologically characterized samples of astrocytomas, meningiomas, and lymphomas. The goal was to elucidate the determinants of 1/T1 of brain tumors at the cellular level and, in particular, to search for a possible correlation of the profiles with neoplastic properties, including degree of malignancy. Because of the recently demonstrated contribution of myelin to 1/T1 of white matter, careful histologic analyses were performed to correct for its presence. The range of magnitude of the profiles of differing types and grades of tumors correlates with the range of water content of these tumors; the correlation of water content with cellularity (density of cell nuclei in a histologic preparation), in turn, produces correlations of 1/T1 with tumor type. For all the tumors studied, 1/T1 is proportional to solids content; the constant of proportionality is relatively insensitive to tumor type and, for astrocytomas, grade of malignancy; and is about the same as that of normal gray matter. For low- and intermediate-grade astrocytomas that contain myelin, the myelin-specific contribution to 1/T1 has to be considered to make manifest the underlying correlations, which are best demonstrated at low fields, where the background contribution of water and dissolved oxygen is minimal. At high fields, where most imaging is done, a change in oxygen partial pressure, as for example from ischemia in very malignant tumors, is sufficient to alter 1/T1 significantly, reducing the intrinsic correlation between histology and 1/T1.
 ...
PMID:Magnetic field dependence of 1/T1 of human brain tumors. Correlations with histology. 217 37

Several procedures have been proposed for pharyngoesophageal reconstruction. The use of a revascularized free jejunal graft currently appears to be a method of choice for anatomical, physiological and technical reasons. The authors currently look back on a series of 90 patients having received a revascularized free jejunal graft between 1978 and 1989 inclusive. The indications predominantly include cancer of the pharynx invading the posterior wall and preserving the cervical esophagus, requiring total circular pharyngolaryngectomy (77 cases). Some benign lesions involve reoperated patients (13 cases). The technique for obtaining the jejunal graft is accurately codified: use of the 3rd jejunal loop in isoperistaltic conditions, refrigeration during the period of ischemia, revascularization by the cervical vessels. If a salvage operation is needed, it is necessary to prepare a saphenous venous graft at the beginning of the operation (3 cases). These grafts must be observed daily. Early negative signs include unexplained epistaxis, blood in the saliva, cervical skin suffering. Emergency fiberscopy must be performed with a bronchoscope or a rhinofiberscope. In case of suffering or necrosis of the graft, the patient must be reoperated immediately and a second free jejunal graft must be placed. The absence of postoperative mortality, low morbidity and good functional results obtained in the series are convincing reasons for using this procedure.
 ...
PMID:[Pharyngoesophageal reconstruction using a vascularized free jejunal graft. Indications--technique and surveillance. Report of 90 cases]. 222 43

Superoxide dismutases (SOD) and their changes in diabetes, aging, ischemia and cancer were studied, Cu, Zn-SOD undergoes glycation reaction in vitro and in vivo and loses its activity by formation of Amadori compounds. Two lysine residues of Cu, Zn-SOD, Lys-122 and Lys-128 are primary glycated sites which are located on the surface of the molecule. The sites are also located on the active site liganding loop which plays a major role in the activity. The glycated Cu, Zn-SOD increased in the red cells of diabetic patients, especially those with diabetic complications. Mn-SOD appears in the serum of patients with acute myocardial infarction in a biphasic manner. The enzyme appears in sera 16 hr and 108 hr after the attack as determined by ELISA. The Mn-SOD levels are also increased in the serum of patients with epithelial ovarian cancer and it is a good marker for detecting and monitoring this cancer. Mn-SOD may play an important role in the ischemic and cancer tissues.
 ...
PMID:[Superoxide dismutases: significances in aging, diabetes, ischemia and cancer]. 223 47

Curative resection of pancreatic and hepatobiliary tumors is rarely possible because of local invasion, especially into the portal vein. We developed a new antithrombogenic catheter using a heparinized hydrophilic polymer to allow portal vein bypass during resection of tumors invading the portal vein. Pancreatectomy or hepatectomy accompanied by portal vein resection was performed for pancreatic or hepatobiliary cancer, with an intraoperative shunt from the superior mesenteric vein to the femoral vein or from the superior mesenteric vein to the intrahepatic portal vein through the umbilical vein or the hepatic hilar portal vein. Use of the shunt prevented stasis in the superior mesenteric vein and hepatic ischemia even during prolonged occlusion of the portal vein, and portal vein resection was performed in 81 patients with hepatobiliary and pancreatic disease with greater safety and ease.
 ...
PMID:Portal vein resection with a new antithrombogenic catheter. 223 72

Six patients with no previous signs or symptoms suggestive of coronary artery disease developed acute coronary ischemia/infarction shortly after cis-diamine-dichloroplatinum II (cisplatin) -based chemotherapy. In two patients this was the sole chemotherapeutic agent used. One patient underwent coronary angiography which disclosed no pathology, but following which, while on a calcium channel blocking agent regimen, he had an uneventful course of chemotherapy with cisplatin. Documentation of cisplatin-related vascular events is important in view of the growing number of patients who undergo cisplatin-based chemotherapy.
Cancer Invest 1990
PMID:Acute coronary events following cisplatin-based chemotherapy. 229 51

Fluorescein-isothiocyanate dextran (FITC-dextran), a dye confined to the vascular space, was infused via the hepatic artery and portal vein into perfused livers from fed rats treated with diethylnitrosamine for 4 to 5 months. Fluorescence due to FITC-dextran was detected with fiberoptic microlight guides placed on surface nodules of about 5 mm in diameter. Nodules were categorized into groups with normal and compromised microcirculation based on their fluorescence following infusion of FITC-dextran. Similar results were obtained when nodules were classified based on reflectance of trypan blue. Despite compromised microcirculation, ATP and ADP levels as well as ATP/ADP ratios were comparable in both groups of nodules; however, AMP was elevated in FITC-dextran-negative nodules (i.e., those with compromised microcirculation). Nodules with compromised microcirculation also contained higher glucose and lactate levels than nodules that were well perfused; however, glycogen was five times lower than in FITC-dextran-positive nodules. Fasting reduced ATP/ADP ratios in poorly perfused nodules in comparison to well-perfused nodules. In perfused livers from fed rats where glycogen was high, however, ATP/ADP ratios and rates of ATP depletion during ischemia were the same in well-perfused and poorly perfused nodules. Products of glycogen breakdown (e.g., glucose and lactate) were elevated in nodules from livers of fed but not fasted rats. The results indicate that alteration of perfusion of hepatic nodules does not change ATP levels nor the capacity of nodules to utilize high energy phosphate during anoxia. Thus, near normal energy status is maintained from glycogen metabolism in poorly perfused nodules via glycolysis. Since basal ATP content and utilization is comparable in well and poorly perfused nodules, compromised energy status is unlikely to explain selection of nodules that regress to near normal hepatocytes.
Cancer Res 1989 Jun 15
PMID:Adenine nucleotides and carbohydrates in subpopulations of hepatic nodules with normal and compromised microcirculation. 247 May 3


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>