Drug and tissue factors both confound KA measurements.
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Receptors, Drug↗
Biomedical subjects
M Lutz
Publications and source records attributed to M Lutz.
Occlusive vascular stapling in a canine inferior vena cava model.
A canine model for inferior vena cava resection was devised to study the biomechanical and clinical applications of the cartridge stapler, which applies a triple staggered staple line. Eighteen mongrel dogs were subjected to subhepatic, suprarenal inferior vena cava occlusion with excision of the excluded segment. At 1 hour, six dogs were killed and inferior vena cava sizes and pressures were measured. All staple lines were intact. The inferior vena cava bursting pressure was 150 to 300 mm Hg. Ten dogs survived to 6 weeks and underwent repeat laparotomy with excision and measurement of the remaining inferior vena cava. Mean diameter was 1.9 cm. No evidence of staple line leakage was found despite chronic pressures to 39 cm H2O: median static bursting pressures were 250 mm Hg. Vein wall thickness of greater than 0.24 mm were all satisfactorily stapled. Histologic examination revealed normal reendothelialization, with improved healing at higher chronic pressures. No evidence of inflammation at the staple line or foreign body reaction was found. We conclude that a triple staple line provides secure, rapid venous occlusion that can withstand supraphysiologic stresses immediately and at 6 weeks.
Animals↗
Efficacy of concomitant early summer treatment with fenbendazole and clorsulon against Fasciola hepatica and gastrointestinal nematodes in calves in Louisiana.
The efficacy, safety, and compatibility of fenbendazole (FBZ) and clorsulon (CLN) were tested after oral administration of label recommended and of higher (5x) dosage rates to calves naturally infected with gastrointestinal nematodes and Fasciola hepatica. Results for 42 calves allotted to 4 treatment groups indicated a similar efficacy against mature F hepatica by FBZ (5 mg/kg of body weight) and CLN (7 mg/kg) in a combined oral suspension, compared with CLN (7 mg/kg) alone (100 vs 99% reduction). A lesser efficacy was observed against immature flukes (88.6 and 84.9% reduction, respectively). Calves given 25 mg of FBZ/kg and 35 mg of CLN/kg had nearly complete reduction of both mature (99.6%) and immature flukes (99.1%). Fasciola egg counts were reduced by greater than 99.5% in all treated groups. Against Ostertagia ostertagi, the percentage of efficacy of the combined FBZ (5 mg/kg) and CLN (7 mg/kg) treatment was 94.3% against adults and 81.3% against inhibited larvae. Efficacy against all other nematodes was 100%, except against Cooperia spp adults (98.3%) and immature Oesaphagostomum radiatum (88.0%). At 5 x dosage rates for FBZ and CLN, percentage of removal of adults and inhibited larvae of O ostertagi was 99.3 and 99.0%, respectively, and 99 to 100% for other nematodes. Results indicate that FBZ and CLN are compatible when mixed together and administered as an oral suspension to cattle and that the efficacy is similar to that of the drugs individually. On the basis of further results, we suggest that summer treatment may be superior in preventive value for gastrointestinal nematodes and F hepatica, compared with spring treatment, because of seasonal infection dynamics of the major cattle parasites in Louisiana.
Animals↗
Structure of spheroidene in the photosynthetic reaction center from Y Rhodobacter sphaeroides.
The structure of the reaction center of Y Rhodobacter sphaeroides has been solved at 3 A resolution, using the atomic coordinates of the reaction center from the carotenoidless mutant R26 Rhodobacter sphaeroides. The structure has been refined by a stimulated annealing with the computer program X-PLOR, leading to a crystallographic R factor of 0.22 using reflections between 8 and 3 A. The spheroidene molecule which is bound to the Y reaction center has been fitted in the electron density map as a 15-cis isomer with a highly asymmetric structure. The cis-bond is located at proximity from ring 1 of the accessory bacteriochlorophyll on the inactive M side. The nature of the cis-bond was confirmed by resonance Raman spectra obtained from Y reaction center crystals. The structure of spheroidene in Y reaction center is compared to that proposed for 1,2-dihydroneurosporene in Rhodopseudomonas viridis reaction center crystals.
Bacterial Proteins↗
Flavin and heme structures in lactate:cytochrome c oxidoreductase: a resonance Raman study.
Resonance Raman spectra of Hansenula anomala L-lactate:cytochrome c oxidoreductase (or flavocytochrome b2), of its cytochrome b2 core, and of a bis(imidazole) iron-protoporphyrin complex were obtained at the Soret preresonance from the oxidized and reduced forms. Raman contributions from both the isoalloxazine ring of flavin mononucleotide (FMN) and the heme b2 were observed in the spectra of oxidized flavocytochrome b2. Raman diagrams showing frequency differences of selected FMN modes between aqueous and proteic environments were drawn for various flavoproteins. These diagrams were closely similar for flavocytochrome b2 and for flavodoxins. This showed that the FMN structure must be very similar in both types of proteins, despite their very different proteic pockets. However, the electron density at this macrocycle was found to be higher in flavocytochrome b2 than in these electron transferases. No significant difference was observed between the heme structures in flavocytochrome b2 and in cytochrome b2 core. The porphyrin center-N(pyrrole) distances in the oxidized and reduced heme b2 were estimated to be 1.990 and 2.022 A from frequencies of porphyrin skeletal modes, respectively. The frequency of the vinyl stretching mode of protoporphyrin was found to be very affected in resonance Raman spectra of flavocytochrome b2 and of cytochrome b2 core (1634-1636 cm-1) relative to those observed in the spectra of iron-protoporphyrin [bis(imidazole)] complexes (1620 cm-1). These specificities were interpreted as reflecting a near coplanarity of the vinyl groups of heme b2 with the pyrrole rings to which they are attached. The low-frequency regions of resonance Raman indicated that the iron atoms of the four hemes b2 are in the porphyrin plane whatever their oxidation state. The histidine-Fe-histidine symmetric stretching mode was located at 205 cm-1 in the spectra of flavocytochrome b2 and of cytochrome b2 core. It was insensitive to the iron oxidation state and indicated strong Fe-His bonds in both states.
Flavin Mononucleotide↗
Dialysis in the management of pregnant patients with renal insufficiency.
Successful pregnancy in patients on dialysis is uncommon because of a high rate of infertility and complications. The use of hemodialysis to manage pregnant patients needing dialysis has been well reported. However, to our knowledge, only 2 previous cases of pregnant patients using chronic ambulatory peritoneal dialysis (CAPD) have been reported. We discuss 14 pregnancies in 13 women in whom dialysis was used in the management of their pregnancies. Ten pregnancies were successful. Included are 5 successful pregnancies out of 8 managed with CAPD or chronic cycling peritoneal dialysis (CCPD). In comparing the cases managed with CAPD to those managed with hemodialysis, CAPD seems to offer several advantages. These include a more constant biochemical and extracellular environment for the fetus, higher hematocrit levels, infrequent episodes of hypotension, and no heparin requirement. In addition, intraperitoneal insulin facilitates the management of blood glucose in diabetics, and intraperitoneal magnesium facilitates the management of premature labor. Infection, loss of intraperitoneal volume, and loss of peritoneal clearances for solutes and water were not found to be problems.
Adult↗
Gas-containing gallstones. The sonographic "double echo sign".
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Cholelithiasis↗
Effect of structured dietary fiber on bioavailability of amoxicillin.
The effect of structured dietary fiber on the bioavailability of amoxicillin (AMX) was evaluated. Ten healthy volunteers ingested one of two isocaloric, isonitrogenous diets providing 7.8 gm/day (diet I) and 36.2 gm/day (diet II) of structured fiber for 3 days. Then they ingested one tablet (500 mg) AMX after breakfast. The other diet was administered for an additional 3 days and the study was repeated. Plasma and urinary AMX concentrations were measured at 9 and 24 hours, respectively, by a microbiologic technique. An open one-compartment model was used for pharmacokinetic analysis. AMX was absorbed more slowly when ingested with diet I than with diet II: the absorption rate constant was 1.04 +/- 0.37 and 1.75 +/- 0.75 (P less than 0.05); lag time for absorption was 0.34 +/- 0.13 hours and 0.29 +/- 0.11 hours (P less than 0.05). The first-order rate constant and elimination half-life were similar. Bioavailability was higher with diet I: the AUC was 12.17 +/- 3.04 vs. 9.65 +/- 2.64 micrograms/ml/hr with diet II (P less than 0.05). A higher content of dietary fiber increased AMX absorption rate and decreased the amount of drug absorbed.
Absorption↗
[A comparison of thermomechanical and conventional root canal filling technics in vitro].
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Bismuth↗
Fibronectin plasma levels after cadaver kidney transplantation.
The fibronectin plasma levels of 17 patients undergoing cadaver kidney transplantation were determined serially in the postoperative course using laser nephelometry. While 9 patients retained their grafts (group A), the grafts of 8 patients had to be removed (group B), mainly due to rejection, 3 patients had severe infections. In both groups a significant drop of the plasma fibronectin occurred after surgery. There were no significant differences between the two groups in the mean fibronectin levels. After the initial drop the group A patients exhibited rising values leading to a stable level. Progressively declining fibronectin plasma concentrations were found in 2 of 3 severely infected patients. Fluctuating values were found in 3 group B patients without a clear correlation to the rejection crises or the kidney function. The data suggest that the fibronectin plasma level does not seem to be a prognostic marker for graft rejection. But it might be useful in the important and often difficult differentiation between rejection and infection.
Adult↗
Structural characterization of high 800 nm-absorbing light-harvesting complexes from Rhodospirillales from their resonance Raman spectra.
Resonance Raman spectroscopy provided evidence that high 800 nm-absorbing antennae from Rhodopseudomonas (Rps.) acidophila and Rps. palustris have similar structures around their dweller bacteriochlorophylls. These host-site structures are different from those of B 850-800 complexes from Chromatiaceae, which also exhibit a high absorbance at 800 nm. As also shown by previous biochemical data, these complexes might be stoichiometrically different from other antenna complexes, having one more BChl per minimal size unit of protein. A new classification of B 850-800 complexes is proposed, on the basis of resonance Raman and biochemical data: this classification distinguishes a class of B 850-800 S (involving the B 850-800 complexes from sulfur purple bacteria), two classes of B 850-800 NS (involving the B 850-800 complexes from non sulfur purple bacteria) and a class of H 800 complexes (involving the B 850-800 complexes from non sulfur purple bacteria exhibiting a high absorbance at 800 nm).
Bacterial Proteins↗
Characterization of [4Fe-4S]2+, [4Fe-4Se]2+ and hybrid (S, Se) clusters in Clostridium pasteurianum ferredoxin. A resonance Raman study.
Resonance Raman spectra of native 2[4Fe-4S] ferredoxin from Clostridium pasteurianum and of its selenium-substituted analogue 2[4Fe-4Se] are compared. The experimental conditions used in this study included low temperature (approx. 25K) and the absence of a glass sample cell, thus ensuring high signal-to-noise ratios. The spectra of the 2[4Fe-4S] and 2[4Fe-4Se] ferredoxins display similar numbers of bands, but the resonance Raman patterns differ largely, except for two bands observed at 353 cm-1 and 365 cm-1 in spectra of the native ferredoxin, which are only moderately shifted upon S----Se substitution and are attributed to Fe-S(cysteine) stretching modes. The activities of the latter modes, enhanced by 457.9 nm excitation, are nearly equal in both ferredoxins. These data were used to demonstrate the presence of hybrid clusters [4Fe-(4-n)S-nSe] (n = 1, 2, 3) in a ferredoxin the active sites of which had been reconstituted in the presence of both S and Se.
Clostridium↗
Structural differences between [2Fe-2S] clusters in spinach ferredoxin and in the "red paramagnetic protein" from Clostridium pasteurianum. A resonance Raman study.
The [2Fe-2S] ferredoxin ("Red paramagnetic protein", RPP) from C. pasteurianum has been found to be composed of two identical subunits of 10,000 +/- 2 000 daltons, each containing a [2Fe-2S] cluster. Resonance Raman (RR) spectra of RPP have been obtained at 23 degrees K, and compared to those of spinach ferredoxin (Sp Fd). Ten modes of the [2Fe-2S] chromophore were observed in the 100-450 cm-1 range. Assignments of non fundamental modes in the 500-900 cm-1 range allowed correlations between fundamental stretching modes of RPP and Sp Fd. Although assuming a [2Fe-2S] structure, the chromophore of RPP differs from that of Sp Fd by its conformation and by a slight weakening of Fe-S bonds, involving both the inorganic core and the cysteine ligands.
Clostridium↗
Resonance Raman spectroscopy of Azotobacter vinelandii ferredoxin I. Vibrational features of the [3Fe-3S] cluster.
Low temperature resonance Raman spectra have been obtained for Clostridium pasteurianum and Bacillus stearothermophilus ferredoxins. Several heretofore undetected fundamental bands have been observed and these data have been used to discriminate the vibrational contribution of the [3Fe-3S] cluster to the spectrum of Azotobacter vinelandii ferredoxin I. The vibrational features of the [3Fe-3S] core distinguish it from other 3-iron clusters and imply structural differences among this class of iron-sulfur clusters.
Azotobacter↗
Synthetic perfusate for kidney preservation. Its use in 72-hour preservation of dog kidneys.
Hydroxyethyl starch (HES) was used as the sole colloid for oncotic support in a perfusate for successful (12 of 12 survivors) 72-hour kidney preservation by hypothermic-pulsatile perfusion. Posttransplant renal function was consistently better than that obtained with other perfusates commonly used in continuous perfusion preservation. Often the posttransplant serum creatinine levels rose to only 1.6 mg/dL and rapidly returned to normal (1.0 mg/dL). The perfusate included, in addition to HES, gluconate as the major anion in place of chloride. Perfusate containing high levels of potassium produces results equal to those with high levels of sodium. This is, to our knowledge, the first report of consecutive successful 72-hour preservation of canine kidneys using a purely synthetic perfusate devoid of animal-derived protein for colloid oncotic support.
Animals↗
Comparison of the effect of temperature on kidney cortex mitochondria from rabbit, dog, pig, and human: Arrhenius plots of ADP-stimulated respiration.
The effect of temperature on the rate of ADP-stimulated respiration of mitochondria from dog, rabbit, pig, and human kidney cortex mitochondria was plotted according to the Arrhenius relationship. The temperature at which the plot demonstrated a break was at 15 degrees C for mitochondria from dog, pig, and human kidneys. The discontinuity occurred at 10 degrees C or less for mitochondria from rabbit kidneys. This difference suggests that mitochondria from rabbit kidneys undergo a lipid-phase transition at lower temperatures than for other species commonly used in experimental renal preservation. The implications of this difference suggest caution in using results obtained with rabbit kidneys for comparison to results obtained from hypothermic renal preservation of other species kidneys. Apparent fluidization of dog kidney mitochondrial membranes with adamantine abolished the discontinuity in the Arrhenius plot.
Adamantane↗
Cognitive impairments of aphasics in picture sorting and matching tasks.
On the basis of earlier experiments showing a differential deficit of aphasics in picture sorting and matching tasks, two experiments were conducted to test the conjecture of a specific deficit of aphasics in the analytical appraisal of individual features. Broca's and Wernicke's aphasics--according to clinical diagnoses and the Aachener Aphasie Test--were compared with patients having right-hemisphere lesions or left-hemisphere lesions without aphasia. Both groups of aphasics differed from the control groups in the sorting task, irrespective of the sorting criterion, but the differences were small. The picture matching task did not discriminate between groups. Obviously, the basic assumption has to be modified with respect to specific conditions of task requirements. The experimental literature is reviewed.
Aphasia↗
Resonance Raman spectra of deoxyhemoproteins. Heme structure in relation to dioxygen binding.
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Animals↗