Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C1522282 (EMT)
 2,868 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pediatric prehospital care was reviewed over a one-year period to determine success rate, causes of unsuccessful attempts, and complications of performing endotracheal intubation. The Milwaukee County Emergency Medicine Technician-Paramedics (EMT-Ps) responded to 1467 pediatric (less than 19 years of age) patient calls. This accounted for 11% of the patients who received EMT-P care during the study period. Of the 63 patients requiring pediatric endotracheal intubation, 49 (78%) were successfully intubated. Of the 42 pulseless nonbreathing (PNB) patients, 39 (93%) were successfully Of the 21 patients judged to be in impending respiratory failure, 10 (48%) were successfully intubated. Common difficulties in intubating the PNB patient included inability to visualize the glottis and cords secondary to mucus and/or vomitus, use of inappropriately small endotracheal tubes, and accidental extubation during transport. Difficulties in intubating impending respiratory failure patients included patient resistance and seizure activity. We recommend that the EMT-P training curriculum include a review of these difficulties and that prehospital pediatric endotracheal intubation performance be monitored and reviewed with the EMT-Ps.
 ...
PMID:Prehospital pediatric endotracheal intubation performance review. 271 Jun 61

Because the initiation of IV lines by emergency medical technicians-Intermediates (EMT-Is) appeared to delay the patient's transport to the hospital, we undertook a retrospective study of 370 patients to compare prehospital care rendered by EMTs (EMT-A equivalent) and EMT-Is in a rural setting. Our study was limited to acute medical conditions in which protocols called for IV lines (124 patients with chest pain, 122 with acute respiratory distress, 99 with seizures, and only 25 with cardiac arrest) (the cardiac arrest cases were too few for statistical significance). We found that the difference in scene times for EMTs and EMT-Is not attempting IV lines was 6.1 and 6.9 minutes, respectively. The average scene time of EMT-Is attempting an IV line was 19.6 minutes (P less than .001) compared with EMT times, or times for EMT-Is not attempting an IV line. One hundred twenty-eight of 370 patients received IV medication within ten minutes of arrival in the emergency department, and ten of these patients had their IV lines initiated successfully in the field. Thirty-nine percent of patients with ED IV lines received IV medication within ten minutes of arrival, while only 21% of patients with a field IV line received medication in this period (P less than .05). We conclude that initiating a field IV line in this specific patient population significantly increased scene time and did not improve the chances of these patients receiving IV medication within ten minutes of arrival in the emergency department.
 ...
PMID:Prehospital care by EMTs and EMT-Is in a rural setting: prolongation of scene times by ALS procedures. 271 61

By comparing mouth-to-mouth ventilation to other methods, we tested whether there are significant differences among infant mannequin ventilation methods performed by emergency medical technicians-paramedics (EMT-Ps). Fifty-nine participants were evaluated in the performance of six ventilation methods; methods studied were mouth-to-mouth; two mouth-to-mask devices; and infant, pediatric, and adult bag-valve-mask devices. By measuring each breath, the percentage of acceptable ventilations in predetermined ranges, 5 to 25 mL/kg or 10 to 20 mL/kg, was calculated. Methods were compared using repeat measures ANOVA testing. Correlation between ventilation performance and the experience of personnel was expressed as the Pearson correlation coefficient. There were no significant differences in performance between methods, except for inadequate ventilation with the Laerdal Pocket Mask (P less than .05) from poor mask fit. The correlation between years of prehospital experience and the number of resuscitations versus ventilation performance was poor. Single rescuer, EMT-Ps can successfully ventilate an infant mannequin with various size resuscitation bags. The Laerdal Pocket Mask is an ineffective device for infant mannequin ventilation and should not be recommended for infant resuscitation.
 ...
PMID:A comparison of infant ventilation methods performed by prehospital personnel. 272 84

Some investigators have suggested that the marked activity of flavone acetic acid (FAA) against advanced solid tumors in mice results from an indirect effect. This study indicates that the critical effect of FAA is irreversible inhibition of tumor blood flow. Perfusion of sc Colon 38 tumors, assessed with H33342 as a fluorescent stain for functional blood vessels, was reduced to 50% of controls within 3 hours of an ip injection of 1.2 mmol of FAA/kg and was completely inhibited by 24 hours. A double-label fluorescence technique demonstrated a significant decrease in blood flow in both sc Colon 38 and im EMT-6/Ak tumors as early as 15 minutes after iv treatment with 1.2 mmol of FAA/kg, with progressively enlarging zones of perfusion failure. The rate of cell death in totally ischemic EMT-6 tumors was shown to be sufficiently rapid to represent a major component of the observed antitumor effect of FAA if the flavonoid acts via inhibition of blood flow. Further, avascular EMT-6/Ak multicellular spheroids growing in the mouse peritoneum are relatively resistant to killing by FAA administered iv or ip, despite extensive infiltration with host immune cells. These results indicate that inhibition of tumor blood flow by FAA is a necessary component of its antitumor activity against solid tumors.
 ...
PMID:Blood flow failure as a major determinant in the antitumor action of flavone acetic acid. 273 44

The environment of cells within solid tumors is known to be acidic relative to that in normal tissue, and the viability of tumor cells may depend on mechanisms which maintain intracellular pH (pHi) above the extracellular pH (pHe). We have assessed therefore the toxicity in vitro of the proton ionophore carbonylcyanide-3-chlorophenylhydrazone (CCCP), since this agent has been reported to be capable of transporting H+ equivalent through artificial lipid bilayers and mitochondrial membranes. CCCP was toxic to the human bladder carcinoma cell line MGHU1 and to the murine mammary sarcoma cell line EMT-6 only at pH, less than 6.5. CCCP transported H+ equivalents through cell membranes at physiological (7.35) and low pHc (6.20). Cell lines were found to have steady-state pHi values approximately 0.1 to 0.2 pH units above pHc at pHc less than 6.50. Addition of CCCP led to a decrease in steady-state pHi values as compared to untreated cells at pHc less than 6.50, whereas there was no apparent effect of CCCP on steady-state pHi values at pHc greater than 6.50. The CCCP-induced reduction in steady-state pHi combined with the uncoupling of oxidative phosphorylation by CCCP appeared to be the major mechanisms leading to cell death at pHc less than 6.50. The toxicity of CCCP under acidic conditions was enhanced by amiloride and 4,4'-diisothiocyanostilbene-2,2-disulfonic acid, agents which are known to inhibit membrane-based ion exchange mechanisms which regulate pHi under acidic conditions. When both agents were combined with CCCP, cell killing was observed at pHc less than 7.30. Our results suggest that mechanisms which regulate pHi under acidic conditions which occur in solid tumors may represent targets for new forms of tumor-specific therapy.
 ...
PMID:Reduction of intracellular pH as a possible mechanism for killing cells in acidic regions of solid tumors: effects of carbonylcyanide-3-chlorophenylhydrazone. 274 36

The partitioning of a series of nine nitroimidazole drugs in liposomes (log Km) of various compositions has been determined and compared to their partitioning in the n-octanol/saline system (log K) at 30 degrees C. The log Km ranged from 1.5 to 0.5 and was three- to fourfold greater than the log K; further, the linear correlation coefficient was greatest when cholesterol (CHOL)-free liposomes were used. Functional-group contributions were compared from their hydrophobic substituent constants and, except in the case of RO-07-2044 and iodoazomycin riboside, yielded negative values in all systems. Literature values of four pharmacokinetic parameters obtained in dogs and acute LD50 values of the nitroimidazoles in BALB/c mice were highly correlated with log K or log Km only in CHOL-free liposomes. Comparing the relative sensitizing effect of the nitroimidazoles in murine EMT-6 or Chinese hamster V79 tumor cell cultures and their partition coefficients, the correlation in EMT-6 cells was poor, whereas the correlation in V79 cells was greater than 0.9 when log Km was used but less than 0.6 when log K was used. Thus, the liposome model is a better predictor of nitroimidazole activity than the n-octanol/saline system and, also, it is a more flexible model for selecting the optimum conditions for QSAR studies.
 ...
PMID:Correlation of partitioning of nitroimidazoles in the n-octanol/saline and liposome systems with pharmacokinetic parameters and quantitative structure-activity relationships (QSAR). 274 30

Vital dye uptake and postfixation dye assays have recently been used to examine the interaction between short-term (24-48 h) exposures to the monokine, tumor necrosis factor (TNF), and hyperthermic treatments with the finding that synergistic increases in cytotoxicity occurred. However, survival measured by these short-term dye assays is not necessarily closely related to eventual loss of clonogenic capacity. Treatment-induced growth delays, delayed cytotoxic effects, or perturbations of vital dye sequestration mechanisms could result in a different measurement of surviving fraction than given by a clonogenic assay. In this study we directly compared the neutral red vital dye uptake and clonogenic survival assays and confirmed in both assays that TNF-sensitive (L-929) and TNF-resistant (EMT-6) phenotypes show greatly reduced survival when treated with combined recombinant human TNF (1.0-0.0005 micrograms/ml) and hyperthermia (1-2 h at 43 degrees C). Moreover, we confirmed that sensitization of the TNF-resistant EMT-6 cells was largely dependent on monokine treatment before hyperthermia and was reduced by the reverse sequence. The greatest sensitization of TNF-responsive L-929 cells also occurred when TNF treatment preceded heating. These results for clonogenic survival are consistent with the hypothesis that hyperthermia used in combination with TNF in vivo is more cytotoxic than TNF or hyperthermia separately.
 ...
PMID:Neutral red uptake and clonogenic survival assays of the hyperthermic sensitization of tumor cells to tumor necrosis factor. 275 21

Fluoromisonidazole labeled with H-3 or F-18 has been tested as a quantitative probe for hypoxic cells in vitro and in rodent and spontaneous dog tumors in vivo. In V-79, EMT-6(UW), RIF-1, and canine osteosarcoma cells in vitro, the binding of 50 microM [H-3]Fluoromisonidazole was 50% inhibited by 1000-2000 ppm O2, relative to binding under anoxic conditions. After a 3 hr incubation with labeled drug, the anoxic/oxic binding ratios ranged from 12 to 27 for the four cell types. Retention of [H-3]fluoromisonidazole 4 hr after injection was greater in large KHT tumors (400-600 mm3) with an estimated hypoxic fraction greater than 30%, than in smaller tumors (50-200 mm3) with an estimated hypoxic fraction of 7-12%. RIF-1 tumors, with an estimated hypoxic fraction of 1.5%, retained the least label, with tumor: blood ratios ranging from 1.7 to 1.9. Spontaneous dog osteosarcomas were imaged with a time of flight positron emission tomograph for up to 5 hr following injection of [F-18] fluoromisonidazole. Analysis of regions of interest in images allowed creation of dynamic tissue time activity curves and calculation of tissue uptake in cpm/gram. These values were compared to radioactivity in plasma. In all cases, retention in some tumor regions exceeded that in plasma and in normal tissue, such as muscle or brain, by 3 to 5 hr post injection. Uptake of fluoromisonidazole in tumors was heterogeneous, with ratios of maximum to minimum uptake as high as 4 in different regions of interest in the same tumor. Tumor:plasma values ranged from 0.28 to 2.02. The oxygen dependency of fluoromisonidazole retention was similar in a variety of cell types and was 50% inhibited by O2 levels in the transition between full radiobiological hypoxia and partial sensitization. The quantitative regional imaging of [F-18] fluoromisonidazole in spontaneous canine tumors at varying times post-injection lays the basis for imaging and modeling of oxygen-dependent drug retention in different regions of human neoplasms.
 ...
PMID:Radiolabelled fluoromisonidazole as an imaging agent for tumor hypoxia. 280 61

The effects of a range of different analogs of nicotinamide and benzamide on the X ray response of the EMT-6 tumor in vivo was investigated. Using an in vivo/in vitro survival assay, sensitization was seen at a dose of 2 mmole/kg for all but one of the analogs tested. The enhancement ratios (ER's) ranged from 1.0 to 1.5. Of particular interest were nicotinamide and SR-4350 which gave large ER's (1.5 and 1.4 respectively) at doses which were only about 12% of the LD50 values. In one normal tissue studied (skin reaction) a large single dose of nicotinamide (8 mmole/kg) only gave an ER of 1.1. These results will be discussed with reference to the mechanisms involved and the clinical implications.
 ...
PMID:Preferential tumor radiosensitization by analogs of nicotinamide and benzamide. 294 59

The four main fractions of hematoporphyrin derivative were separated by high-pressure liquid chromatography. Each fraction was studied with respect to photosensitizing capabilities, fluorescence, and tumor tissue uptake in mice bearing EMT-6 tumors. Animals received i.p. injections of 10 mg/kg of each fraction, and 24 h later tumors either were treated with 100 J/cm2 of light (630 nm) to evaluate photosensitizing capabilities, or the animals were sacrificed and tumors removed for fluorescence and fraction uptake determination. The results indicate that the fraction responsible for photosensitization has the highest tumor tissue uptake and retention. Furthermore, this fraction demonstrates the highest overall fluorescence localization in neoplastic tissue. The other poorly photosensitizing fractions have a lower overall fluorescence in vivo due to their poor tumor tissue localization.
 ...
PMID:Biological studies on the main fractions of hematoporphyrin derivative. 294 36


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