- Loop diuretic therapy in the critically ill: a survey. [Journal Article]
- CCCrit Care Resusc 2015; 17(3):223-6
- CONCLUSIONS: Australian and New Zealand intensivists typically give frusemide as a 40 mg IV bolus for a positive fluid balance, ALI and APO, but not for an elevated CVP or AKI. However, such therapy is given without explicit definitions of an adequate response under these different clinical circumstances.
- Thyroxine binding to the apolipoproteins of high density lipoproteins HDL2 and HDL3. [Journal Article]
- EEndocrinology 1992; 131(6):2805-11
- Four preparations of high density lipoprotein HDL2, five of HDL3, and purified apolipoproteins apoA-I, apoA-IV, and apoE were photoaffinity labeled with [125I]T4 and analyzed by sodium dodecyl sulfat...
Four preparations of high density lipoprotein HDL2, five of HDL3, and purified apolipoproteins apoA-I, apoA-IV, and apoE were photoaffinity labeled with [125I]T4 and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Gels were also immunoblotted with antiserum against apoA-I, apoA-II, apoA-IV, apoE, or apo(a), and the immunostained membrane was then autoradiographed. In HDL2, the two major radioactive bands migrated near the origin of the resolving gel and at 28-31 kilodaltons (kDa). The first band, stained by anti-apo(a) and anti-apoB-100, accounted for 40-96% of the total radioactivity and was attributed to lipoprotein(a), which is isolated in the same density range as HDL2. The second band, stained by anti-apoA-I, accounted for 1-57% [41-95% after correction for contaminating lipoprotein(a)] of the [125I]T4 in the resolving gel. In HDL3, the major radioactive band was identified as apoA-I and contained 93-94% of the [125I]T4 in the resolving gel. Minor radioactive bands in both HDL2 and HDL3 were identified as apoA-II (17-18 kDa), apoA-II monomer (7-10 kDa), apoE (36-38 kDa), and apoAII-apoE heterodimer (46 kDa). In addition, HDL3 contained apoA-IV (43 kDa). Photoaffinity labeling of isolated apoA-IV and apoE showed that each protein interacted with [125I]T4. In both HDL2 and HDL3, photoaffinity labeling in the presence of unlabeled L-T4 (1-10 microM) showed inhibition, suggesting a Kd in the micromolar range. This inhibition varied among different apo bands of the same HDL2 or HDL3 preparation and among the same bands of different preparations. Labeling in the presence of heparin or other inhibitors of T4 binding to plasma proteins (furosemide, diclofenac, and mefenamic acid) showed that HDL2-associated apoA-I was more sensitive to inhibition than HDL3-associated apoA-I. In conclusion, 1) HDL2 and HDL3 carry T4 mainly through apoA-I and secondarily through apoA-II and apoE. The inter- and intrasubclass variations in T4 binding and sensitivity to inhibitors can be explained by the known heterogeneity of HDL particles and possible differences in conformation of the apo. The findings reported here, that apo other than apoA-I and apoB exhibit saturable binding of T4, suggest that thyroid hormone-lipoprotein interactions may have even wider physiological implications than previously appreciated.
- Characterization of the binding of thyroxine to high density lipoproteins and apolipoproteins A-I. [Journal Article]
- JCJ Clin Endocrinol Metab 1989; 68(6):1067-72
- We studied binding of T4 to the lipid-complexed apolipoproteins (apo) of high density lipoproteins (HDL), the major lipoprotein carrier of thyroid hormones in human plasma, and to lipid-free apoA-I. ...
We studied binding of T4 to the lipid-complexed apolipoproteins (apo) of high density lipoproteins (HDL), the major lipoprotein carrier of thyroid hormones in human plasma, and to lipid-free apoA-I. HDL isolated from fresh normal plasma by ultracentrifugation (density, 1.063-1.210 g/mL) was photoaffinity labeled with [3,5-(125)I]T4 and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two bands corresponding to apoA-I (28.3K) and apoC-II or apoC-III (8.6-9.2K) were seen, and their radioactivity decreased by 50-60% when labeled in the presence of 1 mumol/L T4. Photoaffinity labeling of isolated apoA-I also was demonstrated and was decreased 74% by 1 mumol/L T4, suggesting a higher affinity of the lipid-free protein for T4. T4 binding of isolated apoA-I was optimal at pH 7-8, reached a maximum after 1 h at 23 C, and decreased after incubation at 37 C. Scatchard analysis revealed a single T4-binding site with a Ka of 7.5 x 10(7) L/mol at 23 C, pH 8.2. The potency of T4 analogs as inhibitors of T4 binding to isolated apoA-I was L-T4 = D-T4 = triiodothyroacetic acid = L-rT3 much greater than L-T3 much greater than L-thyronine. The binding of T4 to apoA-I was reduced by known inhibitors of T4 binding to serum proteins (diclofenac = mefenamic acid = furosemide = 8-anilinonaphthalene sulfonic acid much greater than dilantin greater than heparin greater than barbital) and by lipids (unsaturated fatty acids greater than cholesterol = cholesterol esters = phospholipids greater than saturated fatty acids = diglycerides = triglycerides). We conclude that the binding of T4 to HDL is mediated by a specific interaction of the hormone with apoA-I and with apoC-II and/or apoC-III. Since the lipid constituents of HDL inhibit T4 binding to apoA-I, the HDL subfraction in plasma that carries most of the HDL-bound T4 should be one with a low lipid content.
- Experience with a sulfonamide diuretic in a large urine drug testing program. [Journal Article]
- JAJ Anal Toxicol 1987 Sep-Oct; 11(5):215-8
- Gas chromatography/mass spectrometry (GC/MS) with selected ion monitoring is a common confirmation method for tetrahydrocannabinol (THC) metabolites in urine. Department of Defense laboratories use t...
Gas chromatography/mass spectrometry (GC/MS) with selected ion monitoring is a common confirmation method for tetrahydrocannabinol (THC) metabolites in urine. Department of Defense laboratories use this method for analysis of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THCA) following ion exchange column purification and methylation. Furosemide, a common diuretic which is excreted into urine, will be isolated with THCA in the extraction procedure, will appear in the chromatographic window [retention time relative to 11-nor-delta-9-tetrahydrocannabinolmethyl ether-9-carboxylic acid methyl ester (THCA-Me) of 1.13], and will exhibit the six ions monitored for THCA-Me and its trideuterated analog. The results indicate that methylated furosemide and other common diuretics can easily be distinguished from THCA-Me. They also allow one to explain in court the extraneous peaks in a chromatogram and to correct for the overutilization of derivatizing reagent.