Three-year study of targeted screening for methicillin-resistant Staphylococcus aureus at hospital admission.
Explore the source record for details and available documents.
Carrier State↗
Biomedical subjects
F Y Leung
Publications and source records attributed to F Y Leung.
A comparison of the metal content of some benthic species from coastal waters of the Florida panhandle using high-resolution inductively coupled plasma mass spectrometry (ICP-MS) analysis.
Benthic marine invertebrates, sediment, and water from several locations along the Florida panhandle coast from St. Joseph Bay in the west to the mouth of the Wakulla River in the east, including from several river estuaries, were analyzed by double focusing ICP-MS (Finnigan MAT ELEMENT) for Cd, Hg, Pb, Cu, Zn, and As. All were detected in all samples. Sponges generally contained higher levels of Cd than other species. Microciona prolifera sponges from St. Joseph Bay had higher As levels (8.1-13.6 microg/g dry weight) than sponges collected from Dickerson Bay or Appalachee Bay (2.20-9.7) and higher Cd levels (0.43-0.73) than that of a single Microciona specimen collected from Dickerson Bay (0.29). Water content of As was about 20-30x higher in St. Joseph Bay than in any other location, and sediment levels of Cd were about 9x higher. Cu and Zn were higher in organic sediment from St. Joseph Bay than they were in other areas. The Pb content of several sponge species and two of tunicates was considerably higher than in other species. The uptake of most metals in this study (except As) appeared to be affected by the metal, genus, species, and location as much as by levels in either water or sediment. In general, sponges and tunicates seemed to accumulate higher levels than most other species, possibly a function of high filtration rates. The ICP-MS method is useful for environmental studies, but the instrument requires considerable maintenance.
Animals↗
Selenium and zinc levels in surgical patients receiving total parenteral nutrition.
The zinc and selenium levels of 40 surgical patients were monitored pre- and post-TPN. The initial selenium level was low normal, and the initial zinc level was also low. Both selenium and zinc are potent antioxidants involved in cellular defense against free radicals. Surgical patients are at risk for selenium and zinc deficiencies secondary to both increased needs and losses. TPN blood work protocols should include monitoring of selenium and zinc with supplementation of the nutrient solutions, as required.
Adult↗
Alcohol and poor compliance as factors in Wernicke's encephalopathy diagnosed 13 years after gastric bypass.
A severely obese man achieved rapid and significant weight loss after Roux-en-Y gastric bypass. Thirteen years later Wernicke's encephalopathy developed as a result of the patient's alcoholism, poor compliance with his micronutrient intake, poor oral intake and the decreased absorptive ability of the small bowel. In selecting any operation to treat morbid obesity the possibility of metabolic problems must be considered as well as the potential for substantial weight loss.
Alcoholism↗
Determination of silicon in serum and tissue by electrothermal atomic absorption spectrometry.
OBJECTIVES: To employ an electrothermal atomic absorption spectrometry (ETAAS) method with chemical modifiers for the determination of silicon (Si) in serum and tissues. METHODS: Si was measured in serum of chronic hemodialysis patients, and in fibrous breast capsule tissues following silicone-gel implant removal. Tissue was dried, and digested with concentrated nitric acid prior to analysis. A chemical modifier, which included lanthanum oxide and ammonium phosphate, was used to dilute the serum, and digested tissue samples (1:4) before atomization. Si was determined at 251.6 nm in a graphite fumace using an atomic absorption spectrophotometer. RESULTS: The method was linear (to 1000 micrograms/L), and precise (CV 5.9% at 281 micrograms/L and 8.4% at 73 micrograms/L). Recovery of Si in spiked serum and breast tissue samples was between 97-104%. Reference values for women on a normal diet and no exposure to silicone implants gave serum Si to 30 to 209 micrograms/L (n = 60), and breast tissue levels of 0.25 to 2.4 micrograms/g dry wt (n = 48). Si in breast capsule from women exposed to silicone breast implants varied from 29 to 496 micrograms/g dry wt (n = 10). Serum Si in hemodialysis patients (n = 53) ranged from 900 to 3300 micrograms/L. CONCLUSIONS: We conclude that our chemically modified ETAAS method is suitable for Si determination in normal and elevated human serum and tissue specimens.
Breast↗
Elevated serum chromium in patients on total parenteral nutrition and the ionic species of contaminant chromium.
Chromium (Cr), an essential micronutrient required for glucose metabolism, was found in high concentrations in up to 94% of the patients on short-term total parenteral nutrition. Approximately 50% had serum levels > 10-fold of normal (upper reference value of 3.8 nmol/L), about 18% were > 20-fold, and about 2% were 40-fold higher. The major Cr contaminant was detected in the amino acid constituents, and was found to have the trivalent ionic form. Although trivalent Cr is reported to be less genotoxic, further study is required to determine the effects on cells exposed to high concentrations of this element during parenteral nutrition over an extended period of time.
Adolescent↗
Abnormal trace elements in a patient on total parenteral nutrition with normal renal function.
OBJECTIVE: To describe trace metal changes in a 74-year-old male patient with mesenteric fibrosis and a small bowel fistula who was maintained on total parenteral nutrition in the hospital and at home. METHODS: Trace elements which included chromium and selenium were monitored over a 14-month period as part of his nutrient follow-up. RESULTS: Serum chromium reached levels > 21-fold the upper reference range, and serum selenium, in contrast, was < 0.5 the lower reference range. Plasma aluminum was also measured, and found to be nearly twice the upper reference range, although the patient had normal renal function. We measured the aluminum content of the parenteral nutrients and additives, and found that replacement of calcium gluconate by calcium chloride helped to reduce the aluminum content in the final parenteral solution by 34%. Aluminum and chromium contaminants found in parenteral solutions need to be reduced or removed to avoid toxic accumulation. CONCLUSION: This study illustrates the importance of adequately adjusting essential trace elements, and monitoring contaminants in parenteral fluids in an individual on total parenteral nutrition.
Aged↗
Trace elements in parenteral micronutrition.
OBJECTIVE: To update some essential trace metals required in total parenteral nutrition. CONCLUSION: Essential trace metals, chromium, copper, manganese, molybdenum, selenium, and zinc are added to parenteral fluids to prevent the development of deficiency syndromes. When possible, these metals should be monitored, even in patients on short-term total parenteral nutrition (TPN) to avoid deficiency or toxicity. Many of the nutrients or additives used in parenteral solutions may be contaminated with metals, such as aluminum or chromium. Such trace-metal monitoring becomes more critical in infants, and those on long-term TPN.
Adult↗
Aluminum determined in plasma and urine by atomic absorption spectroscopy with a transversely heated graphite atomizer furnace.
We compared a stabilized-temperature L'vov platform furnace containing an end-heated graphite atomizer (HGA) and transverse Zeeman background-correction system with a side-heated furnace system (transversely heated graphite atomizer; THGA) containing a longitudinal Zeeman background-correction system for the determination of aluminum in plasma and urine. The regression statistics for the correlation analysis of the two systems (slope coefficient = 0.995, intercept = -1.710, Sy/x = 0.021 micrograms/L) indicate that the systems generate comparable results. The newer technology of the THGA furnace with its more uniform and faster heating cycle allows a lower atomization temperature for aluminum, 2200 degrees C. Analyte carryover was significantly reduced in the THGA furnace system. The THGA system generates results equivalent to HGA in about one-third less time, thus making possible a greater throughput of samples in a busy laboratory.
Aluminum↗
Reference intervals for blood lead and evaluation of zinc protoporphyrin as a screening test for lead toxicity.
We evaluated, retrospectively, 2921 blood samples for the distribution of blood lead values in children below age 16, and in adult female and male subjects. An upper reference value for children and females at 0.48 mumol/L, and for males at 0.72 mumol/L is used. Over 70% of the adult males and > 80% of the children and adult females were within these reference limits, and considered to be at low risk for lead toxicity. The diagnostic utility of zinc protoporphyrin (ZPP) to screen for a positive blood lead result was evaluated using receiver operating characteristic (ROC) curves and likelihood ratios (LR). These studies confirmed that ZPP was insensitive for the detection of elevated blood lead at the critical thresholds of 0.48-1.21 mumol/L in children and adult females with subclinical lead poisoning. ZPP was more diagnostically useful for screening the higher lead-exposed adult male occupational worker.
Adolescent↗
Diagnostic evaluation of creatine kinase-2 mass and creatine kinase-3 and -2 isoform ratios in early diagnosis of acute myocardial infarction.
The diagnostic efficacy of creatine kinase (CK) isoforms (CK-3 and CK-2) was compared with measurement of CK-2 mass concentrations for the early diagnosis of myocardial infarction (MI). Serial serum samples drawn from 76 patients with confirmed MI and 55 non-MI patients were used for determining CK-2 mass concentrations and the MM3/MM1 (CK-3 isoforms) and MB2/MB1 (CK-2 isoforms) ratios. We compared the diagnostic utility of each by receiver-operating-characteristic (ROC) curve and likelihood ratio analyses. Our results indicate that all three tests were ineffective within the first 4 h after the onset of chest pain. All three were most effective at 4-18 h after onset, but both CK-3 and CK-2 isoform ratios were less effective than CK-2 mass concentrations in the next 6-h period (18-24 h). In the critical time between 3 and 6 h, the diagnostic performance of all three was comparable.
Adult↗
Relationships among borderline features, body dissatisfaction and bulimic symptoms in nonclinical females.
The present study evaluated the utility of combining measures of body dissatisfaction and borderline personality features in screening high-school girls who may be at risk for bulimia nervosa. Two samples (777 high-school girls and 22 bulimic women in-treatment) completed scales assessing borderline traits, body dissatisfaction, eating symptoms, and associated psychiatric disturbances. Students were divided into four groups, respectively showing: (a) high body dissatisfaction and borderline traits, (b) high body dissatisfaction alone, (c) high borderline traits alone, or (d) neither vulnerability component. Clinical and nonclinical groups were then compared for severity of eating and psychiatric symptoms. Girls displaying the combination of high body dissatisfaction and borderline traits (our presumed "high-risk" group) showed an elevated profile of eating and associated disturbances, highly comparable to the bulimic group. They were also more likely to receive threshold and subthreshold diagnoses of bulimia nervosa (according to simulated diagnoses based on self-report items) than subjects in other high-school groups. Implications of these findings were discussed with reference to the "two-component" model of eating disorders.
Adolescent↗
Personality and family features of adolescent girls with eating symptoms: evidence for restricter/binger differences in a nonclinical population.
Conflicting evidence exists concerning a "restricter/binger" dichotomy aligned with personality traits of obsessionality versus impulsivity, and family traits of enmeshment versus incohesion. The present study explored relationships among reported personality and family traits, on the one hand, and subtypes of eating symptoms, on the other, in a sample of 715 high-school girls. Symptomatic eaters (most displaying subclinical eating problems) consistently displayed more Mood Problems, Body Concerns, and Self-Criticism than did asymptomatic girls. Differences were observed between restrictive eaters and binge eaters on other variables: Restrictive types were more Perfectionistic, whereas bingers were more Impulsive and rated their families as more Incohesive. Results were discussed in the light of two views on restricter/binger differences. That they reflect: (a) premorbid features acting in predisposition to the eating disorders (EDs). (b) state-dependent features associated either with restrictive or binging phases of eating disturbances.
Adolescent↗
Comparison of the diagnostic utility of timed serial (slope) creatine kinase measurements with conventional serum tests in the early diagnosis of myocardial infarction.
We compared the diagnostic utility of recently proposed slope assays for serum creatine kinase and creatine kinase-2 with the optimized decision threshold assays. The former approach has been claimed to be superior to any other single diagnostic technique. We show, by ROC curve and likelihood ratio analyses, that the total creatine kinase slope assay possesses the same diagnostic power, when confidence intervals are used, as the optimized decision threshold assay. Moreover, slope assays of creatine kinase-2 were diagnostically inferior to the optimized decision threshold assays. Indeed, these latter, optimized, assays have the highest likelihood ratios for a positive test result of the available assays, and they should always be used in situations of diagnostic doubt.
Adult↗
Serum creatine kinase 2 (CK-MB) in myocardial infarction: measure activity, percentage of total CK, or both?
Explore the source record for details and available documents.
Creatine Kinase↗
Time-related changes in the diagnostic utility of total lactate dehydrogenase, lactate dehydrogenase isoenzyme-1, and two lactate dehydrogenase isoenzyme-1 ratios in serum after myocardial infarction.
Using receiver-operating characteristic (ROC) curve and likelihood ratio analysis, we examined the diagnostic utility of total lactate dehydrogenase (LD; EC 1.1.1.27) activity (I). LD isoenzyme-1 activity (II), and the LD-1 percentage of total LD activity (III), LD-1 LD-2 (IV), and LD-1/LD-4 (V) in 347 persons admitted to the Cardiac Care Unit (of whom 173 were subsequently proven to have had myocardial infarction). Blood was sampled from these subjects at about 6-h intervals for up to 96 h from the onset of chest pain. Defining an "effective" test as one having an area under the ROC curve of greater than or equal to 0.9, we determined the ranked utility (greatest to least) of these tests as V = IV greater than III greater than II greater than I. Tests III, IV, and V had by this criterion, diagnostic effectiveness equivalent to measurements of creatine kinase-2 in serum but in samples obtained at later time intervals. The decision thresholds for both high (constant) test sensitivity and specificity varied with time, to differing extents, over the entire 96-h period, a finding with important diagnostic implications. We document positive and negative likelihood ratio values for each of these tests throughout the entire period of study.
Adult↗
Quality control procedures for monitoring whole blood and plasma trace metal levels by atomic absorption spectrophotometry.
Well co-ordinated quality control procedures are required to insure that trace metal results determined at ppb (micrograms kg-1 or micrograms l-1) levels by atomic absorption spectrophotometry are reliable. Control materials can be prepared "in-house" provided they are calibrated against standard reference materials (SRM). A mean +/- SD data base should be determined for each quality control material with daily results plotted on Levey-Jennings charts. Westgard's multi-rule quality control scheme is recommended for assessing analytical performance. Additional information may be obtained by using cumulative sum (cusum) charts to detect analytical drift from the mean, and standard deviation index or 'z-score' plot to show analytical bias. Proficiency or quality assurance programs should be used to supplement internal quality verification of analytical performance.
Humans↗
A computer program to determine diagnostic decision thresholds and likelihood ratios illustrated with aspartate aminotransferase activities after a myocardial infarction.
We describe an enhancement of our earlier computer program which allows calculation of decision thresholds, sensitivity and specificity, and likelihood ratios of negative and positive test results for any chosen value of sensitivity or specificity. The program will also plot continuous receiver operating characteristic and decision level curves which permit examination of the contours created by using all the available data. We illustrate the value of these routines by showing that the sensitivity and specificity of serum aspartate aminotransferase changes during the course of a myocardial infarction.
Aspartate Aminotransferases↗