Metalloclusters of the nitrogenases.
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Amino Acid Sequence↗
Biomedical subjects
B E Smith
Publications and source records attributed to B E Smith.
Subclinical histopathological changes in the oculomotor nerve in diabetes mellitus.
To provide reference values for the oculomotor nerve, for example, fascicular area and myelinated fiber (MF) number and size distribution, in pathological states, and to determine whether oculomotor nerves from diabetic patients without a history of oculomotor palsy have subclinical structural alterations, the morphometric features of 15 control subjects and eight diabetic patients were evaluated at a proximal and a distal level. On average the control nerves had a fascicular area of 2.7 mm2, 22,311 MF, and a bimodal diameter distribution with peaks at approximately 5 to 6 and 10 to 11 microns and a range of 2 to 20 microns. In proximal nerve, glial bundles were found in one-half of the subjects and patients, with a peak of MF sizes that differed from fibers in nonglial areas. The nerves from diabetic patients departed from the nerves from control subjects in the following two respects: changed size distribution, suggesting atrophy of fibers, and microfasciculation of edge fibers in parts of the fascicles in one-half of the patients. We conclude that glial bundles are probably a normal variant. Microfasciculation occurred much more frequently in nerves from diabetic patients and may represent subclinical injury of unknown cause. The alteration in size distribution may reflect the diabetic state and is not necessarily a precursor to diabetic ophthalmoplegia.
Adult↗
Clinical evaluation--continuous real-time intra-arterial blood gas monitoring during anesthesia and surgery by fiber optic sensor.
A clinical evaluation of the clinical utility, techniques of use, durability, accuracy, and potential complications of a newly available system for the continuous real-time, intra-arterial monitoring of arterial blood gas and acid base status (ABG) has been studied (Optex BioSentry System, Optex Biomedical, Incorporated, The Woodlands, Texas, U.S.A.). The system consists of three separate fiber optic channels with contained fluorescent and absorbant chemical analytes imbedded in a single probe and capable of insertion inside of a twenty gauge indwelling arterial catheter (The Optex Optode Sensor), along with an external monitor. The system was utilized during anesthesia and surgery in the care of five informed patients. Constant trend monitoring of all three variables was deemed satisfactory in four of the patients. The fifth sensor was damaged by a surgical assistant while in place and ceased to function. Comparison of Optode sensor readings with standard clinical laboratory ABG analysis was excellent in three uncomplicated patients (pH: bias -0.0183 pH units, precision: 0.0237 pH units; PCO2: bias 3.22 mmHg, precision 2.04 mmHg; PO2: bias -5.94 mmHg, precision 11.74 mmHg). Postoperative study suggested that discrepancies in a fourth patient may have been due to an incorrect 'offset' applied to the Optode sensor yielding a constant error.
Adult↗
Voltage fields surrounding needles used in regional anaesthesia.
Using a bench model, we have studied the voltage fields surrounding both insulated and uninsulated needles used in regional anaesthesia. The findings were compared with earlier computer predictions which suggested that the fields would be markedly different for the two types of needle. The results confirm that the fields differ markedly and suggest that the use of insulated needles may not necessarily improve the accuracy of nerve location and that uninsulated needles may be more appropriate.
Anesthesia, Conduction↗
Control of renal hemodynamics after protein feeding: role of calcium channels.
This study was designed to test the hypothesis that the changes in renal hemodynamics that occur after a high-protein meal involve voltage-dependent calcium channels. In chronically instrumented female dogs, a 10-g/kg meal of raw beef caused plasma alpha-amino nitrogen levels to increase from 3.9 +/- 0.2 to 6.7 +/- 0.5 mg/dl after 90 min, and glomerular filtration rate (GFR) rose from 59 +/- 6 to 85 +/- 7 ml/min, effective renal plasma flow (ERPF) rose from 130 +/- 22 to 213 +/- 36 ml/min, and sodium excretion rose from 21 +/- 4 to 84 +/- 20 mu eq/min. On another day the dogs were pretreated with verapamil (0.075 mg/kg + 0.005 mg.kg-1.min-1 iv), which did not change arterial pressure significantly but increased GFR by 25 +/- 7% and ERPF by 23 +/- 5%. After a subsequent meat meal, plasma alpha-amino nitrogen increased from 4.0 +/- 0.3 to 6.6 +/- 0.1 mg/dl but GFR, ERPF, and sodium excretion did not change significantly. On the other hand, pretreatment with dopamine, which caused a similar degree of vasodilation to that caused by verapamil, did not prevent the response to a subsequent meat meal. Thus verapamil specifically prevented the normal increases in renal hemodynamics after protein feeding, suggesting that protein-stimulated renal vasodilation requires intact voltage-dependent calcium channels.
Acetylcholine↗
Pressure-flow measurements for selected oral and nasal sound segments produced by normal adults.
Pressure-flow data are often used to provide information about the adequacy of velopharyngeal valving for speech. However, there is limited information available concerning simultaneous pressure-flow measurements for oral and nasal sound segments produced by normal speakers. This study provides normative pressure, flow, and velopharyngeal orifice area measurements for selected oral and nasal sound segments produced by 10 male and 10 female adult speakers. An aerodynamic categorization scheme of velopharyngeal function, including one typical category and three atypical categories (open, closed, and mixed) is proposed.
Adult↗
Linking theory and practice in teaching basic nursing skills.
In an attempt to integrate theory and practice in baccalaureate nursing education, students were taught nursing skills with two cognitive strategies (Vee heuristics and concept maps) that consciously identify and reinforce connections between scientific theory and practice. The research showed that students using Vee heuristics and concept maps, rather than traditional modes, were significantly better able to identify scientific principles to describe why specific steps of a nursing skill were done.
Education, Nursing, Baccalaureate↗
Inflammatory sensory polyganglionopathies.
The inflammatory sensory polyganglionopathies are a group of uncommon neurologic disorders primarily affecting dorsal root ganglion cells and their processes. Subdivided into malignant and nonmalignant inflammatory sensory polyganglionopathy, these conditions are important in the differential diagnosis of sensory neuropathy. The clinical significance of malignant inflammatory sensory polyganglionopathy, a paraneoplastic syndrome, rests in the discovery of subclinical cancer, which may produce antineuronal nuclear antibodies directed against the dorsal root ganglion cell and other neurons resulting in characteristic neurologic deficits. Prompt recognition of these distinctive signs and symptoms may result in early diagnosis and improved patient survival and lead to a better understanding of immune-mediated neurologic disease.
Ganglia, Spinal↗
The effect of patient weight on the functional outcome of total knee arthroplasty.
Overweight patients are often considered poor candidates for total knee arthroplasty. For assessment of the validity of this proscription, two-year follow-up data from 109 patients were analyzed. Hospital for Special Surgery Scores were recorded, roentgenograms were inspected for radiolucencies, and isokinetic strength tests were conducted. Surgical time, the presence and severity of radiolucencies, and isokinetic joint strength were found to have statistically significant, positive correlations with patient weight. The Hospital for Special Surgery Score was found to have negative correlations with weight for those patients weighing less than 80 kg, and it was found to have negative correlations with the percentage by which patients were heavier than their ideal weights. However, multiple regression analyses indicated that these correlations were caused by patient gender and not by any independent effect due to weight. From a clinical point of view, the results of this study suggest that orthopedists can expect their overweight total knee patients not to be at a significant postoperative functional disadvantage because of their weight during the initial, two-year postoperative period.
Adult↗
Impact of dental sick call on combat effectiveness: the Dental Fitness Class 3 soldier.
Dental sick call can have a significant impact on combat effectiveness, a loss of up to 18,720 man days per division per year. This study identified two target populations that interceptive dental treatment could best be directed toward. They are the E-1 to E-3 pay grades and soldiers in combat arms units. This study also offers dental resources needed to treat various target populations.
Adolescent↗
Plasma exchange in polyneuropathy associated with monoclonal gammopathy of undetermined significance.
BACKGROUND: Polyneuropathy associated with monoclonal gammopathy of undetermined significance (MGUS) has been treated with plasma exchange, intravenous immune globulin, and chemotherapy, but the effectiveness of these treatments remains uncertain. METHODS: We randomly assigned 39 patients with stable or worsening neuropathy and MGUS of the IgG, IgA, or IgM type to receive either plasma exchange twice weekly for three weeks or sham plasma exchange, in a double-blind trial. The patients who initially underwent sham plasma exchange subsequently underwent plasma exchange in an open trial. RESULTS: In the double-blind trial, the average neuropathy disability score improved by 2 points from base line (from 62.5 to 60.5) in the sham-exchange group and by 12 points (from 58.3 to 46.3) in the plasma-exchange group (P = 0.06). A similar difference was observed in the weakness score, a component of the neuropathy disability score (improvement, 1 and 10 points, respectively; P = 0.07). After treatment the summed compound muscle action potentials of motor nerves were 1.2 mV lower (worse) than at base line in the sham-exchange group and 0.4 mV higher (better) in the plasma-exchange group (P = 0.07). The greater degree of improvement with plasma exchange was equal in magnitude to or greater than the difference between not being able to walk on the heels or toes and being able to perform these activities. Changes in the vibratory detection threshold, summed motor-nerve conduction velocity, and sensory-nerve action potentials did not differ significantly between the treatment groups. In the open trial, in which patients who initially underwent sham exchange were treated with plasma exchange, the neuropathy disability score (P = 0.04), weakness score (P = 0.07), and summed compound muscle action potentials (P = 0.07) improved more with plasma exchange than they had with sham exchange. In both the double-blind and the open trial, those with IgG or IgA gammopathy had a better response to plasma exchange than those with IgM gammopathy. CONCLUSIONS: Plasma exchange appears to be efficacious in neuropathy associated with MGUS, especially of the IgG or IgA type.
Action Potentials↗
Computerized monitoring at Vanderbilt University status and future directions.
A computerized monitoring system utilizing touch screen input has been developed and tested at our university. Logical extensions of this technology include the development of a portable input device and the packaging of the physical system. Further extensions of this technology include, as necessary, the introduction of other monitoring modalities, such as respiratory and evoked potential data acquisition and analysis.
Artificial Intelligence↗
Rectus sheath and mesosalpinx block for laparoscopic sterilization.
Thirty patients scheduled to undergo laparoscopic sterilisation were allocated at random to receive either a standardised general anaesthetic and rectus sheath block (group A), or standardised general anaesthetic combined with both rectus sheath and mesosalpinx blocks (group B). Group B patients had significantly less postoperative pain, as assessed by linear analogue scores (p less than 0.025), and analgesic requirement (p less than 0.05). By the 8th postoperative hour all 15 group B patients had been discharged from hospital, whilst only seven of 15 patients in group A were considered suitable for discharge at this time, (p less than 0.05).
Abdominal Muscles↗
Regulation of renal hemodynamics after protein feeding: effects of loop diuretics.
These studies were designed to test the hypothesis that the renal vasodilation and increased glomerular filtration rate (GFR) after a high-protein meal are mediated by the tubuloglomerular feedback (TGF) mechanism. In eight chronically instrumented conscious dogs, a meal of raw beef (10 g/kg) caused GFR to increase from 66 +/- 5 to 90 +/- 7 ml/min and effective renal plasma flow (ERPF) to increase from 191 +/- 25 to 281 +/- 24 ml/min, while plasma alpha-amino N levels rose from 4.0 +/- 0.1 to 7.3 +/- 0.6 mg/dl. On another day the dogs were given an infusion of furosemide to block TGF, and fluid and salt losses were continuously replaced. Furosemide alone caused GFR to increase in most animals, although the average change did not reach statistical significance, and ERPF increased by 31%. Sodium excretion rose from 15 +/- 5 to 2,390 +/- 280 mueq/min, and urine flow rose from 1.17 +/- 0.22 to 20.5 +/- 2.4 ml/min. Autoregulatory capability was also abolished (autoregulatory index = 0.87 +/- 0.09 compared with 0.19 +/- 0.05 before furosemide). However, there was no significant change in GFR and ERPF after a subsequent meat meal in dogs receiving furosemide. On another day, some of the dogs were given another loop diuretic, ethacrynic acid, which caused no change in GFR, whereas its effects on ERPF, sodium excretion, and urine output were similar to those of furosemide. There were also no changes in GFR or ERPF after a meat meal during ethacrynic acid administration, despite normal increases in plasma alpha-amino N.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
The Rochester Diabetic Neuropathy Study: design, criteria for types of neuropathy, selection bias, and reproducibility of neuropathic tests.
A cross-sectional survey and subsequent longitudinal study among diabetic residents of Rochester, MN--The Rochester Diabetic Neuropathy Study (RDNS)--is population-based and uses quantitative, validated, and unique end points to detect, classify, and stage neuropathy. Nondiabetic persons, drawn from the same population, serve as controls. For patients 10 to 70 years old, the RDNS cohort is representative of diabetics living in Rochester, MN. We assessed reproducibility of tests used to characterize and quantitate severity of neuropathy in 20 diabetic subjects without neuropathy and with varying severities of neuropathy. Using intraclass correlation coefficient (rI) as a measure of test reproducibility, we found high rI (usually 0.9 or better) with small confidence intervals for the Neurologic Disability Score (NDS); weakness subset of NDS (W-NDS); vibratory and cooling detection thresholds (using computer-assisted sensory examination [CASE] IV); compound muscle action potentials; sensory nerve action potentials; and motor nerve conduction velocities. There was good agreement among three trained observers for NDS and the W-NDS.
Action Potentials↗
Pressure-flow measurements for selected oral and nasal sound segments produced by normal adults.
Pressure-flow data are often used to provide information about the adequacy of velopharyngeal valving for speech. However, there is limited information available concerning simultaneous pressure-flow measurements for oral and nasal sound segments produced by normal speakers. This study provides normative pressure, flow, and velopharyngeal orifice area measurements for selected oral and nasal sound segments produced by 10 male and 10 female adult speakers. An aerodynamic categorization scheme of velopharyngeal function, including one typical category and three atypical categories (open, closed, and mixed) is proposed.
Adult↗
A 31P-NMR study of the mechanism of and salt effect on Mg2(+)-ATP exchange.
The study of exchange between free and metal-bound ligands by NMR methods is discussed with reference to differentiation between unimolecular dissociation of the metal-bound complex and biomolecular exchange of metal ion between two ligands. This is applied to exchange of ATP4- between the free and Mg2(+)-bound states and problems of interpretation in the presence of a strong kinetic salt effect are discussed. Contrary to a previous report, exchange is inferred to occur mainly via unimolecular dissociation of MgATP2- over a range of temperatures, concentrations, and pH values, which include those expected in vivo. For the model system Mg2(+)-tripolyphosphate, an activation energy of 52 +/- 5 kJ.mol-1, inferred to be that for dissociation of MgTPPH2-, is found for the exchange process.
Biological Transport↗