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

Transfemoral cannulation of renal vessels with the Seldinger technique has been used as well as routine angiography in the following urologic indications. 1. Hypothermic in situ perfusion of the kidney in difficult surgical procedures on the renal parenchyma, e.g., multiple stones, stag-horn calculi, benign and malignant tumors in solitary, residual or functionally residual kidneys. The advantages of this method are sufficient time for surgery, no contamination of blood and therefore excellent view by means of complete ischemia and good long-term results of the renal function. 2. Embolization of inoperable renal tumors to reduce tumor growth and control bleeding. The material used for embolization was a modified preparation of homogenized autologous muscle tissue. 3. Occlusion of the renal artery prior to tumor nephrectomy by a flow-guided balloon catheter in order to reduce the difficulty of the surgical produce, e.g., in massive carcinomatous infiltration of the hilus vessels. 4. Retrograde phlebography of the left internal spermatic vein in recurrent or persistent varicocele and in infertility with only insignificant or doubtful varicocele. The advantage compared with orthograde phlebography via plexus pampiniformis is the direct evidence that the venous reflux causes the varicocele. When the technique has been mastered transfemoral cannulation of the renal vessels can be used in routinely in the clinic Critical consideration of the indications, however, is necessary.
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PMID:[Transfemoral cannulation of the renal vessels. Diagnostic and therapeutic use in urology (author's transl)]. 84 52

Simultaneous measurement of cardiac output distribution with 86Rubidium and 57Cobalt-tagged microspheres in rats implanted with liver tumors by intraportal injection of sarcoma cells enables quantitation of arterial and portal tumor circulation. The portal circulation was found to be increased in small tumors as compared to the liver, but as the tumor grew there was a decrease in the portal tumor circulation. When the tumor growth became massive even the total liver circulation was reduced, as measured with 133Xenon wash-out. All the tumors had increased arterial circulation. This arterial hyperperfusion was changed into ischemia when the liver artery was occluded through embolization with degradable microspheres.
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PMID:The circulation in liver tissue and experimental liver metastases before and after embolization of the liver artery. 91 87

A bioassay is described for the quantitation of tumor cells in blood specimens in a syngeneic mouse tumor system (Sarcoma 1 in A/J mice). The procedure involved i.m. injection of blood containing tumor cells into each thigh of normal recipient mice and, 14 days later, examination of the sites of injection for evidence of tumor growth. For each specimen, a tumor index was calculated based on the number of tumor takes and the size of the tumors. The number of tumor cells was determined by comparison with tumor indices from standard specimens with known number of tumor cells. Optimal conditions for this assay were investigated. We have used this bioassay to quantitate tumor cells in the venous blood of tumor-bearing animals under various treatments and manipulations. At the same time, the incidence of regional node metastasis was obtained by direct histological examination. Surgical removal of a well-established primary tumor enhanced the dissemination of the tumor, as evidenced by an increased incidence in regional node metastasis and an increase in the number of tumor cells reaching the venous circulation. Similar results were obtained when the tumor-bearing feet were ligated to produce ischemia of the primary tumor. Repeated physical trauma to the primary tumor resulted in increased dissemination of tumor cells into the venous circulation, but it did not increase the incidence of regional node metastasis. Immunosuppression of the tumor-bearing animals increased the dissemination of tumor cells, whereas immunostimulation decreased the dissemination.
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PMID:Bioassay for quantitating circulating tumor cells in a syngeneic mouse tumor system. 126 58

The role of superoxide and lipid peroxidation for anti-tumor effect of intra-arterial injection with degradable starch microspheres (DSM) was investigated in rabbits. The anti-tumor effect of intra-arterial injection with DSM was studied in rabbits with VX2 carcinoma of the hind leg. The tumor growth in rabbit treated with DSM 5 times was completely suppressed, and thiobarbituric acid (TBA)-reactive substances in the tumor tissue treated with DSM were significantly increased. But the anti-tumor effect of DSM and the increase in TBA reactive substances in the tumor tissue treated with DSM were significantly inhibited by treatment with superoxide dismutase combined with catalase. These results suggest that the anti-tumor effect of intra-arterial injection with DSM may be due to ischemia-reperfusion injury and that active oxygen species and lipid peroxidation may play an important role in the anti-tumor effect of intra-arterial injection with DSM.
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PMID:[Role of oxygen species and lipid peroxidation for anti-tumor effect of intra-arterial injection with degradable starch microspheres]. 187 37

The time- and dose-dependent effects of recombinant human interleukin 1 alpha (IL-1 alpha) on the antitumor activity of mitomycin C (MMC) and porfiromycin (PORF) were studied in RIF-1 and Panc02 solid tumor model systems. IL-1 alpha produced dose-dependent sensitization of clonogenic RIF-1 tumor cells to MMC in vivo. IL-1 alpha chemosensitization was highly schedule dependent, and the most efficacious schedules produced dose-modifying factors of 3.6 and 5.1 for MMC and PORF, respectively. More than additive clonogenic cell kill after IL-1 alpha-chemotherapy combinations reflected increased cellular sensitivity to MMC and PORF. The combinations also produced marked decreases in the yield of viable tumor cells, suggesting that the bioreductive drugs may have also potentiated the microvascular injury and ischemia produced by IL-1 alpha. Dexamethasone inhibited and ketoconazole, an inhibitor of corticosterone biosynthesis, enhanced IL-1 alpha-mediated chemosensitization in these models. IL-1 alpha mediated chemosensitization to MMC, and PORF was also demonstrated by tumor growth inhibition in the RIF-1 model and increased survival of mice in the spontaneously metastasizing Panc02 system. Chemosensitization of bone marrow spleen colony-forming units was not seen. IL-1 alpha (1000 units/ml) had no effect on MMC and PORF cytotoxicity in RIF-1 and PORF cell lines in vitro. The results indicate that the tumor-specific IL-1 alpha-induced pathophysiologies can sensitize solid tumors to agents which are preferentially activated, retained, and cytotoxic to cells under hypoxic conditions. Our results suggest that strategies combining bioreductively activated hypoxic cell cytotoxins and biological agents might offer efficacious alternatives or adjuvants to conventional combination approaches.
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PMID:Potentiation of mitomycin C and porfiromycin antitumor activity in solid tumor models by recombinant human interleukin 1 alpha. 191 64

The antitumor agent flavone-8-acetic acid (FAA) is remarkable because it induces hemorrhagic necrosis, altered tumor blood flow, and cytokine synthesis. We show here that FAA and structurally related analogues increase plasma nitrite plus nitrate (NO2-/NO3-) levels in mice. Dose-dependent increases in plasma NO2-/NO3- concentrations, which reached maximum levels at 12 h, were found following administration of FAA. Furthermore, the presence of a palpable s.c. Colon 38 tumor significantly enhanced the response. Tumor-dependent increases were also observed with the active FAA analogues xanthenone-4-acetic acid, 5-methyl XAA, and 5,6-dimethyl XAA, while the inactive analogue 8-methyl XAA failed to increase plasma NO2-/NO3- concentrations substantially above basal levels. Increased plasma NO2-/NO3- levels were also observed in response to endotoxin (100 micrograms/mouse) and to recombinant human tumor necrosis factor alpha (4 to 16 micrograms/mouse). NO2-/NO3- levels may signify nitric oxide production as a result of stimulation of the L-arginine-dependent pathway in activated macrophages. The tumor dependence of the response may reflect the immunological stimulus imposed by tumor implantation. A clear relationship was found between increased plasma NO2-/NO3- levels and tumor growth delays induced by FAA and xanthenone-4-acetic acid analogues. It is suggested that nitric oxide may contribute to tumor cell death by two mechanisms, alteration of blood flow contributing to tumor ischemia and direct tumor cell killing. Plasma NO2-/NO3- concentrations may be a sensitive indication of the antitumor response to this class of compounds.
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PMID:Tumor-dependent increased plasma nitrate concentrations as an indication of the antitumor effect of flavone-8-acetic acid and analogues in mice. 198 9

The effect of repeated ischemic episodes to experimental liver tumors is studied in a group of inbred Wistar-Furth rats. A vascular occluder model was developed specially for the purpose of delivering intermittent compressions to the hepatic artery in the rat. With five daily 1-hr occlusions of the hepatic artery, rats benefited from significantly reduced tumor growth rates compared with controls that underwent sham operation (P less than 0.05). In contrast to results from previous pig experiments, it is demonstrated by angiographic studies that repeated transient dearterialization does not entirely overcome the problem of collateral vessel formation in the rat. Tumor neovascularization continues irrespective of whether the tumor is being dearterialized. It is also observed that in both normal and tumor rats, collateral channels from the left gastric artery temporarily open up when the hepatic artery is obstructed but disappear on reestablishment of flow. As such types of collateral flow are beyond our control, it is imperative that future developments in vascular occlusion therapy should aim at shortening ischemia time and combining with chemotherapy.
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PMID:Retarding liver cancer growth in the rat by transient repeated hepatic dearterialization. 291 14

We performed a study of hyperthermia while injecting 0.05% of Noradrenaline following MMC for 10 minutes into the feeding artery of Walker-256 carcinosarcomas implanted 6 days earlier into the s.c. dorsum side of hindpaw of Wistar rats. The tumor growth rates on the 6th day after treatment by warning tumor in hot water (40 degrees C, 44 degrees C) for 10 minutes with or without Noradrenaline, were 0.7 +/- 0.6, 2.1 +/- 0.9 (40 degrees C) and 0.2 +/- 0.3, 0.0 +/- 0.0 (44 degrees C), respectively. The data suggested that tumor ischemia induced by a vasoconstrictive drug may enhance the antitumor effect in low grade warning therapy (40 degrees C). An injection of warmed physiological saline (50 degrees C) may heat the tumor vessels on the tumor surface and showed enhanced antitumor effects as a from of hyperthermia. The target area of the tumor for hyperthermia can be considered to be the tumor vessels on the tumor surface.
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PMID:[Enhancement of antitumor effect of MMC on Walker 256 by intra-arterial administration of noradrenaline in hyperthermia]. 313 74

Tumor tissue contains viable hypoxic regions that are radioresistant and often chemoresistant and may therefore be responsible for some treatment failures. A subject of general interest has been the development of non-invasive means of monitoring tissue oxygen. Pulse Fourier transform 31P NMR spectroscopy can be used to estimate intracellular nucleotide triphosphates (NTP), phosphocreatinine (PCr), inorganic phosphate (Pi) and pH. We have obtained 31P NMR spectra as an indirect estimate of tissue oxygen and metabolic status in a C3H mouse fibrosarcoma FSaII. Sequential spectra were studied during tumor growth in a cohort of animals and peak area ratios for several metabolites were computed digitally by computer. During growth, tumors showed a progressive loss of PCr with increasing Pi, and most tumors greater than 250 mm3 in volume had little or no measurable PCr. The smallest tumors (38 mm3 average volume) had PCr/Pi ratios of 1.03 +/- .24, whereas tumors 250 mm3 or more had an average PCr/Pi ratio of 0.15 +/- .04. Similarly derived NTP/Pi ratios decreased with tumor size, but this change was not significant (p = .17). Radiobiologic hypoxic cell fractions were estimated using the radiation dose required to control tumor in 50% of animals (TCD50) or by the lung colony technique. Tumors less than 100 mm3 had a hypoxic cell fraction of 4% (TCD50) while tumors 250 mm3 had a 40% hypoxic cell fraction (lung colony assay). These hypoxic fraction determinations correlated well with the depletion of PCr and decline in NTP/Pi ratios seen at 250 mm3 tumor volumes. Tumor spectral changes with acute ischemia were studied after ligation of the tumor bearing limb and were similar to changes seen with tumor growth. PCr was lost within 7 minutes, with concurrent increase in Pi and loss of NTP. Complete loss of all high energy phosphates occurred by 40 minutes of occlusion. In vivo tumor 31P NMR spectroscopy can be used to estimate tissue metabolic status and may be useful in non-invasive prediction of hypoxic cell fraction, reoxygenation, and radiation treatment response.
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PMID:Tumor size dependent changes in a murine fibrosarcoma: use of in vivo 31P NMR for non-invasive evaluation of tumor metabolic status. 371 Aug 61

The fine structure of the capillary bed of the anterior pituitary has been studied in 19 cases of pituitary tumor and 1 autopsy specimen. Tumor specimens were less well vascularized than the autopsy specimen. Endothelial cells within tumor specimens were often observed with swollen portions of cytoplasm, or cytoplasmic blebs, projecting into the capillary lumen. Blebbing, in many cases, nearly obstructed the capillary lumen and was most often associated with endothelial cells that had an electron-lucent cytoplasm, in contrast to endothelial cells that had an electron-dense cytoplasm, even within the same capillary profile. Compared with electron-lucent cells, electron-dense cells contained more endothelial filaments. Also observed were capillaries that had apparently broken apart releasing their contents into the pericapillary space and shrunken remnants of capillaries. A number of abnormal features were observed in the pericapillary spaces-ie, disruption of the parenchymal-pericapillary interface, disorganization of basal laminae, increased amounts of plasma proteins and cellular debris within the space and, ultimately, complete loss of the normal limits and characteristics of the space. Similar, though less pronounced, changes were observed in the autopsy specimen. The hypothesis is advanced that changes observed in the capillary bed are, in large part, a result of tumor growth, which increasingly disrupts tissue organization at the parenchymal-pericapillary interface and, because the tumor mass in the sella turcica can only enlarge upwards, compresses the pituitary stalk and portal veins. The result is ischemia and eventual necrosis. The observations are then in good agreement with recent reports on changes in capillary fine structure associated with ischemia.
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PMID:Ultrastructural changes in the capillary bed of human pituitary tumors. 505 26


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