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Biomedical subjects

B Steele

Publications and source records attributed to B Steele.

At least 19 recordsLinked to original sources
PubMed1995

Metabolic evaluation of infected renal lithiasis: clinical relevance.

Complete metabolic evaluation was performed in 21 patients with infected renal lithiasis. Patients with pure struvite stones (struvite +/- carbonate apatite) were significantly less likely to have metabolic abnormalities than patients who had struvite +/- carbonate apatite+calcium oxalate (2 of 14 v 7 of 7, P = 0.0003). Urine calcium excretion was markedly higher in the mixed stone group than the pure struvite group (342 +/- 98 mg/24 h v 136 +/- 82 mg/24 h; P < 0.0001). The differing opinions among researchers regarding the likelihood of finding metabolic abnormalities in patients with urolithiasis and infection probably reflect differences in the definitions of the populations studied. If patients with calculi containing only struvite +/- carbonate apatite are evaluated, we believe that few significant metabolic abnormalities will be identified.

Adolescent↗
PubMed1994

Human T lymphocyte subpopulation and NK cell alterations in persons exposed to cocaine.

Immunophenotypic changes in peripheral blood mononuclear cells were analyzed by flow cytometry in several patient groups positive for cocaine in their urine. Single- and dual-color immunofluorescence staining was performed to examine total numbers of NK, T, and B cells, as well as the coexpression of surface molecules on T cells associated with memory function, helper/inducer capacity, and activation status. In addition, levels of several serum proteins (including immunoglobulins) and other demographic variables were evaluated. Our results show that cocaine-intoxicated patients display reductions in the total percentage of CD4+ T cells and increases in the number of NK cells. Dramatic shifts within certain T cell subpopulations were also observed. In particular, there appeared to be a preferential stimulation of "activated" T cells as indicated by increased levels of class II+ CD4 and CD8 T cells and IL2r+ CD4 T cells. "Memory" CD8+ T cell subpopulations (i.e., CD45RO+) were reduced in the cocaine-positive patients, whereas CD45R+/CD8+ T cells were accordingly increased in the same individuals. In some cases, direct correlation could be established between certain T cell percentages and cocaine levels. None of the serum protein levels measured appeared to be influenced by cocaine. These findings demonstrate that cocaine utilization is associated with variations in levels of certain T cell subpopulations and other immune cells. This may represent a disruption of particular immunologic cell networks which could ultimately influence host resistance to infection and malignancy.

Acute-Phase Proteins↗
PubMed1994

Management of lower pole nephrolithiasis: a critical analysis.

The results of extracorporeal shock wave lithotripsy (ESWL*) and percutaneous nephrostolithotomy for the treatment of lower pole nephrolithiasis were examined in 32 consecutive patients undergoing percutaneous nephrostolithotomy at the Methodist Hospital of Indiana and through meta-analysis of publications providing adequate stratification of treatment results. Of 101 cases managed with percutaneous nephrostolithotomy 91 (90%) were stone-free, a result significantly better than that achieved with ESWL (1,733 of 2,927 stone-free, 59%). Stone-free rates with percutaneous nephrostolithotomy were independent of stone burden, whereas stone-free rates with ESWL were inversely correlated to the stone burden treated. The morbidity of patients undergoing percutaneous nephrostolithotomy at our hospital was minimal, with a mean hospital stay of 4.7 +/- 2.8 days. No blood transfusions were required. All patients became stone-free. The percentage of urolithiasis patients with lower pole calculi is increasing. Because of the significantly greater efficacy of percutaneous nephrostolithotomy for lower pole calculi, particularly stones larger than 10 mm. in diameter, further consideration should be given to an initial approach with percutaneous nephrostolithotomy.

Adult↗
PubMed1994

Cortisol inhibition of growth hormone-releasing hormone-stimulated growth hormone release from cultured sheep pituitary cells.

Cortisol inhibits growth hormone (GH) release in short-term culture and is stimulatory in long-term cultures of rat and human pituitary cells. This study sought to determine the in vitro effects of cortisol on GH release and the signal transduction pathways mediating the effects of cortisol on GH release from cultured ovine somatotrophs. Pituitary cells were dispersed with collagenase and placed in culture medium for 4 days. The data indicate that cortisol inhibited growth hormone-releasing hormone (GHRH)-stimulated GH release by at least 2 h. In short-term culture GHRH-, forskolin- and dibutyryl cyclic AMP-stimulated GH release were inhibited by cortisol, suggesting an effect distal to the membrane and involving a protein kinase A (PKA)-dependent pathway. GH release initiated by KCl was inhibited by cortisol, but GH release caused by the calcium ionophore A23187 was unaffected. This suggests a possible action of cortisol on the calcium channels. The inhibition by cortisol of the calcium-dependent secretion of GH release appeared to play a smaller role in mediating cortisol inhibition of GH release than that seen with PKA. Attempts to overcome cortisol inhibition of GH release using puromycin, arachidonic acid or pertussis toxin were unsuccessful. Since cortisol inhibition of GH release does not occur via the mechanisms found in other cell types, cortisol inhibition of pituitary cell secretions appears to be cell-specific rather than utilizing a single inhibitory mechanism. The majority of cortisol actions on the somatotroph appear to act at a site distal to the production of cyclic AMP.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The dyspnea experience: nociceptive properties and a model for research and practice.

Dyspnea has been defined as the unpleasant sensation of difficult breathing and the reaction to that sensation. Dyspnea research, however, has largely used a unidimensional, sensory model of dyspnea devoid of the affective and motivational dimensions that uniquely characterize this sensation in clinical populations. Dyspnea might be more comprehensively viewed as a nociceptive phenomenon which, like pain, has affective dimensions expressed as distress in response to aversiveness. A multidimensional, ecologic model of the dyspnea experience is presented that incorporates nociceptive sensation properties and is suggestive of new directions for dyspnea research uniquely relevant to nursing science.

Dyspnea↗
PubMed1991

How well can radiographers triage x ray films in accident and emergency departments?

OBJECTIVE: To assess the ability of radiographers to identify abnormal radiographs of patients attending accident and emergency departments. DESIGN: Prospective study over six weeks. SETTING: Teaching hospital casualty x ray department. PATIENTS: 3394 consecutive patients referred for radiography. INTERVENTIONS: Radiographs were assessed by radiographers who were offered a four point triage scheme: normal, abnormal, insignificantly abnormal, or further advice required. MAIN OUTCOME MEASURES: Comparison of radiographers' assessments with an assessment made independently by the reporting radiologists. RESULTS: Overall disagreement between the radiographers and radiologists was 9.4%. There were 7% false positives and 14% false negatives. Most errors occurred in assessing radiographs of the skull, facial bones, chest, abdomen, and soft tissues. CONCLUSION: Unselected radiographers can offer useful advice on radiographs to casualty officers, but their high rate of false positive diagnoses indicates that they cannot triage casualty radiographs sufficiently accurately to allow them to extend their current reporting role.

Clinical Competence↗
PubMed1990

Cocaine-related maternal death.

Hemodynamic overload, cardiac ischemia, and arrhythmia are postulated to originate from "sex-cocaine" syndrome resulting in maternal and fetal death. High concentrations of cocaine and metabolites in maternal blood, urine, and nasal secretions confirmed recent ingestion. Changes in the maternal life-style may have contributed to the poor pregnancy outcome.

Adult↗
PubMed1990

The use of serum amylase and lipase in evaluating and managing blunt abdominal trauma.

In order to determine the usefulness of serum amylase and lipase in the initial evaluation and subsequent management of blunt abdominal trauma (BAT) patients, we collected serum amylase and lipase on 85 consecutive BAT patients at admission, hospital day 1, hospital day 3, and hospital day 7. Only one patient had a pancreatic injury. A total of 45 patients (53%) had at least one enzyme abnormality during the study. There was no correlation between amylase or lipase values and age, sex, type of injury, diagnostic tests, operation, and outcome. In a control group of nonabdominal-trauma patients with admit studies only, all enzyme values were normal. We conclude that serum amylase and lipase are randomly elevated in patients with nonpancreatic-BAT both initially and during subsequent hospitalization and are not useful clinical tools in these patients.

Abdominal Injuries↗
PubMed1990

Peritoneal dialysis in the neonate.

The etiology of renal failure in the newborn infant is multifactorial. The increasing survival of low-birthweight infants and the aggressive drug management of pathophysiological disease states such as pulmonary hypertension and patent ductus arteriosus has resulted in an increase in the number of infants presenting with acute renal failure. Experience in our intensive care unit has proved that early intervention with peritoneal dialysis is safe and may significantly reduce both morbidity and mortality in such patients.

Acute Kidney Injury↗
PubMed1986

Renal bicarbonate handling in low birth weight infants during metabolic acidosis.

We studied the fractional excretion of bicarbonate (FE HCO-3) in 10 low birth weight infants aged 1-6 days during metabolic acidosis (base excess greater than or equal to -5 mEq/l) and during subsequent sodium HCO-3 infusion. The mean birth weight was 1,095 g; the mean gestational age was 29 weeks. The ability to decrease urine pH to less than 5.5 and FE HCO-3 to less than 1% during metabolic acidosis was not limited by low gestational age or birth weight. After HCO-3 therapy, all infants corrected their negative base excess, and plasma HCO-3 increased significantly. All infants with blood pH less than or equal to 7.22 or PaCO2 greater than or equal to 50 mm Hg had minimal or absent FE HCO-3. Infants with elevated PaCO2 and mild or absent acidosis also had complete HCO-3 tubular reabsorption. These results suggest that the HCO-3 tubular reabsorption is adequate during metabolic and/or respiratory acidosis in low birth weight infants.

Acidosis↗
PubMed1983

A fluorescent immunoassay for theophylline: description and comparison to enzyme immunoassay, liquid chromatography and radioimmunoassay.

A fluorescent immunoassay for theophylline is described and comparatively evaluated with radioimmunoassay, high-performance liquid chromatography, and enzyme immunoassay. Fifty sera were collected from 43 patients of a large acute-care medical facility, many of whom were suffering from other diseases in addition to bronchial asthma or apnea of the newborn, and were receiving other medication besides theophylline. Assays of theophylline in each serum sample were performed by each of the 4 procedures. The four methods showed comparable results, although each method had at least one unexplained outlier. Nevertheless, all methods seemed suitable for routine chemistry laboratory use. Three of the techniques have been available for several years, but unexplained erroneous levels are sometimes obtained for every procedure.

Chromatography, Liquid↗
PubMed1982

Simultaneous quantitation of quinidine, procainamide, and N-acetylprocainamide in serum by gas-liquid chromatography with a nitrogen-phosphorus selective detector.

We describe a single-run method for quantitating quinidine, procainamide, and N-acetylprocainamide, involving gas-liquid chromatography with a nitrogen-phosphorus selective detector. Within-run precision (CV) was 3% (x = 2 mg/L, n = 20), 6.9% (x = 4 mg/L, n = 10), and 1.5% (x = 8 mg/L, n = 8) for quinidine; 7.7% (x = 4 mg/L, n = 14), 1.6% (x = 8 mg/L, n = 16), and 2.3% (x = 12 mg/L, n = 12) for procainamide; and 6.3% (x = 5 mg/L, n = 6), 3.6% (x = 10 mg/L, n = 20), and 4.0% (x = 20 mg/L, n = 10) for N-acetylprocainamide.l Between-run precision was 3.0%(x = 2 mg/L, n = 20), 7.0% (x = 4 mg/L, n = 9), and 2.8% (x = 8 mg/L, n = 9) for quinidine; 4.7% (x = 4 mg/L, n = 10). 3.3% (x = 8 mg/L, n = 20), and 1.9% (x = 12 mg/L, n = 10) for procainamide; and 9.3% (x = 5 mg/L, n = 6), 4.3% (x = 10 mg/L, n = 20), and 3.8% (x = 20 mg/L, n = 10) for N-acetylprocainamide. Tube stoppers that contain a rubber plasticizer interfere with the technique. Clinical application and correlation with drug concentrations by this technique are discussed.

Acecainide↗
PubMed1982

Results by fluorescent immunoassay for phenytoin compared with those by enzyme immunoassay, liquid chromatography, and discrete analysis (Dupont aca).

We describe the Ames Fluorescent Enzyme Immunoassay procedure for the detection of phenytoin in serum, and compare the results with it with those by enzyme immunoassay(EMIT), "high-pressure" liquid chromatography, and the Dupont aca. Sera from 48 patients who were receiving phenytoin were promptly analyzed in duplicate by EMIT, frozen, then assayed within four weeks by the other three methods. Correlation was good between results by the fluorescent immunoassay and the other methods. The fluorescent immunoassay procedure is sensitive and requires a small sample volume (100 microliters). Sample reading time can be shortened from 30 to 15 s as the technician becomes more proficient, with no sacrifice of accuracy. The procedure is fast, easy to perform, specific, sensitive, and inexpensive; involves no radioactivity; and requires no temperature control. It is the current method of choice for detection of phenytoin in serum, in terms of precision and accuracy.

Chromatography, High Pressure Liquid↗
PubMed1982

Postmortem vitreous humor in fatal acute iron poisoning.

The postmortem level of iron in the vitreous humor was assayed in a case of treated fatal iron poisoning. An antemortem serum iron level was 9060 micrograms/dL and postmortem blood level was 2920 micrograms/dL. A postmortem vitreous humor specimen collected by a standard technique had an iron level of 80 micrograms/dL whereas 23 controls had a mean of 12.8 +/- 4.2 micrograms/dL (range, 6 to 21 micrograms/dL). Although this elevated value could reflect some serum contamination, it may be a reflection of the toxic state.

Death↗