Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.2.1.7 (BAL)
 1,977 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To study the significance of TRH in the hypothalamo-pituitary-thyroid axis measurement of TRH in body fluid are needed. We previously reported TRH radioimmunoassay for urine. TRH radioimmunoassay for serum has not established yet, because TRH immunoreactivity is inactivated with serum. We investigated effects of various factors on this inactivation and method for prevention of this inactivation. Synthetic TRH was added to normal human serum at 4 degrees C and incubated at 60 degrees C, 37 degrees C, 20 degrees C, 4 degrees C or -20 degrees C for various intervals. After incubation, recovery of TRH was measured. After one hour incubation, recovery of TRH was 9.2% at 37 degrees C, 34.5% at 20 degrees C, 100% at 4 degrees C or -20 degrees C. Incubation of TRH serum mixtures at 65 degrees C after incubation at 37 degrees C resulted in some recovery of TRH. After one hour incubation at 37 degrees C, recovery of TRH was 9.2% at serum pH 7.0, 100% at serum pH 3.0 to 5.0 or 11.0. Recovery of TRH was increased in accordance with stepwisely increase of serum dilution. Concentrations of serum thyroid hormone did not affect recovery of TRH. Smaller quantities of TRH were more rapidly inactivated. Inactivation of TRH immunoreactivity could be prevented addition of BAL (over 0.25 mg/ml) or mixture of 8-Hydroxyquinoline (HQ) and Tween 20(T) (over 0.1 mg/ml of HQ and 1 lmg/ml of T). Duration of effectiveness of BAL was short. Effectiveness of HQT continued for 12 weeks, if HQT treated serum was stored at -20 degrees C. From above data it was suggested that TRH immunoreactivity might be inactivated with enzyme system and other factors and TRH levels in the serum might be able to measure with addition of HQT to serum.
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PMID:[Studies of various factors in thyrotropoin releasing hromone TRH) radioimmunoassay for serum (author's transl)]. 0 43

A sensitive and specific radioimmunoassay has been developed capable of measuring thyrotropin releasing hormone (TRH) in extracted human plasma and urine. All of three TRH analogues tested had little cross-reactivity to antibody. Luteinizing hormone releasing hormone, lysine vasopressin, rat growth hormone and bovine albumin were without effect, but rat hypothalamic extract produced a displacement curve which was parallel to that obtained with the synthetic TRH. Sensitivity of the radioimmunoassay was 4 pg per tube with intraassay coefficient of variation of 6.2-9.7%. Synthetic TRH could be quantitatively extracted by methanol when added to human plasma in concentration of 25, 50 and 100 pg/ml. TRH immunoreactivity was rapidly reduced in plasma at 20 degrees C than at 0 degrees C, but addition of peptidase inhibitors, FOY-007 and BAL, prevented the inactivation of TRH for 3 hr at 0 degrees C. The TRH in urine was more stable at 0 degrees C than 20 degrees C, and recovered 75 +/- 4.6% hr after being added. The plasma levels of TRH were 19 pg/ml or less in normal adults and no sex difference was observed. The rate of disappearance of TRH administered i.v. from the blood could be represented as half-times of 4-12 min. Between 5.3-12.3% of the injected dose was excreted into urine within 1 hr as an immunoreactive TRH. These results indicate the usefulness of TRH radioimmunoassay for clinical investigation.
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PMID:Radioimmunoassay of thyrotropin releasing hormone in plasma and urine. 81 57

Impact of blast shock waves (SW) with the body wall produces blast lung injuries characterized by bilateral traumatic hemorrhages. Such injuries often have no external signs, are difficult to diagnose, and therefore, are frequently underestimated. Predictive assessment of acute respiratory distress syndrome outcome in SW-related accidents should be based on experimental data from appropriate animal models. Blood plasma transferrin is a major carrier of blood iron essential for proliferative "emergency" response of hematopoietic and immune systems as well as injured tissue in major trauma. Iron-transferrin complexes (Fe3+ TRF) can be quantitatively analyzed in blood and tissue samples with low-temperature EPR techniques. We hypothesized that use of EPR techniques in combination with assays for pro-inflammatory cytokines and granulocytes in the peripheral blood and BAL would reveal a pattern of systemic sequestration of (Fe3+)TRF that could be useful for development of biomarkers of the systemic inflammatory response to lung injury. With this goal we (i) analyzed time-dependent dynamics of (Fe3+)TRF in the peripheral blood of rats after impacts of SW generated in a laboratory shock-tube and (ii) assayed the fluctuation of granulocyte (PMN) counts and expression of CD11b adhesion molecules on the surface of PMNs during the first 24 h after SW induced injury. Sham-treated animals were used as control. Exposure to SW led to a significant decrease in the amount of blood (Fe3+)TRF that correlated with the extent of lung injury and developed gradually during the first 24 h. Thus, sequestration of (Fe3+)TRF occurred as early as 3 h post-exposure. At that time, the steady state concentration of (Fe3+)TRF in blood samples decreased from 19.7+/-0.6 microM in controls to 7.5+/-1.3 microM in exposed animals. The levels of (Fe3+)TRF remained decreased throughout the entire study period. PMN counts increased 5-fold and 3.5-fold over controls respectively, at 3 and 6 h postexposure. These effects were accompanied by an increase in expression of CD11b on the surface membrane of PMNs. Extensive release of cytokines IL-1, IL-6, MCP-1, and MIP-2 was observed in BAL fluid and blood plasma during 24 h postexposure. We conclude that EPR monitoring of blood (Fe3+)TRF can be a useful approach for assessment of systemic pro-inflammatory alterations due to SW-induced lung injury.
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PMID:Pro-inflammatory alterations and status of blood plasma iron in a model of blast-induced lung trauma. 1616 36