Influence of a Regular, Standardized Meal on Clinical Chemistry Analytes

BACKGROUND: Preanalytical variability, including biological variability and patient preparation, is an important source of variability in laboratory testing. In this study, we assessed whether a regular light meal might bias the results of routine clinical chemistry testing. METHODS: We studied 17 healthy volunteers who consumed light meals containing a standardized amount of carbohydrates, proteins, and lipids. We collected blood for routine clinical chemistry tests before the meal and 1, 2, and 4 hr thereafter. RESULTS: One hour after the meal, triglycerides (TG), albumin (ALB), uric acid (UA), phosphatase (ALP), Ca, Fe, and Na levels significantly increased, whereas blood urea nitrogen (BUN) and P levels decreased. TG, ALB, Ca, Na, P, and total protein (TP) levels varied significantly. Two hours after the meal, TG, ALB, Ca, Fe, and Na levels remained significantly high, whereas BUN, P, UA, and total bilirubin (BT) levels decreased. Clinically significant variations were recorded for TG, ALB, ALT, Ca, Fe, Na, P, BT, and direct bilirubin (BD) levels. Four hours after the meal, TG, ALB, Ca, Fe, Na, lactate dehydrogenase (LDH), P, Mg, and K levels significantly increased, whereas UA and BT levels decreased. Clinically significant variations were observed for TG, ALB, ALT, Ca, Na, Mg, K, C-reactive protein (CRP), AST, UA, and BT levels. CONCLUSIONS: A significant variation in the clinical chemistry parameters after a regular meal shows that fasting time needs to be carefully considered when performing tests to prevent spurious results and reduce laboratory errors, especially in an emergency setting.

Estudo quantitativo de metais presentes na hemolinfa de Biomphalaria glabrata (Gastropoda), infectadas e não infectadas com Schistosoma mansoni / Quantitative study of metal present in the hemolymph of Biomphalaria glabrata (Gastropoda), infected and uninfected with Schistosoma mansoni

Inicialmente, desenvolveu-se um estudo para quantificar e comparar as concentrações de alguns metais presentes em duas amostras de hemolinfa do caramujo Biomphalaria glabrata (infectados e não-infectados com Schistosoma mansoni). A espectrometria de emissão óptica com fonte de plasma induzido (ICP-OES), foi utilizada para analisar os metais nas duas amostras. Os metais estudados foram: alumínio, cálcio, cádmio, cobalto, cromo, cobre, ferro, potássio, magnésio, manganês, chumbo e zinco. Os resultados mostram que, a princípio, os metais não são fatores determinantes no processo de defesa desses organismos contra este parasita, quando presente nos seus tecidos.

Changes in some metalloenzymes and trace metals among workers occupationally exposed to lead in battery manufacture

The present study was conducted aiming to evaluate the impact of lead [Pb] exposure on the activities of some metaloenzymes as TIBC, SOD, ALP and MAO and their related trace metals among workers. Ninety workers occupationally exposed to Pb in a battery manufacturing plant in Alexandria city were included in this study, 50 of them were the exposed group and 40 control subjects. The present study showed a statistically significant higher level of biological indices of exposure [p<0.01] of lead in blood among the exposed group than the control subjects. Exposure to Pb led to decreased levels of Zn and Fe which was accompanied by increase in the level of TIBC and decrease in activity of ALP. However, no significant variation could be detected in the level of Cu and its metalloenzyme as SOD and MAO between exposed and control subjects

Serum trace metal levels in patients with acute hepatitis B.

This study was conducted to determine serum levels of trace metals in young adult patients in the early icteric phase of acute hepatitis B virus infection. There were 15 patients (10 males, 5 females) and 15 healthy volunteers (11 males, 4 females). The age distribution of both groups ranged from 15-40 years and were comparable [mean (SD) = 28(6) vs 31(7) years; p = 0.12]. Compared to the healthy controls, the patients had significantly decreased serum zinc but elevated serum copper levels [means (SD) of zinc = 118(22) vs 97(20) micrograms/dl, p = 0.012; and of copper = 82(15) vs 135(40) micrograms/dl, p < 0.001]. The overall serum levels of calcium, magnesium and phosphorus in the studied patients were within normal ranges. Serum zinc concentrations of these patients correlated with albumin (r = 0.69, p = 0.005) and their serum calcium correlated with alkaline phosphatase (r = 0.61, p = 0.015). These results demonstrate that alterations of zinc and copper metabolism occur early during the acute icteric phase of uncomplicated hepatitis. These changes may be of pathophysiological significance in acute hepatitis, in particular in patients with pre-existing zinc deficiency.

Efecto de la hipervitaminosis a aguda sobre las concentraciones séricas de Na, K, Mg, Fe, Zn y Cu en ratas / Effect of acute hypervitaminosis A on serum concentrations of Na, K, Mg, Fe, Zn and Cu in rats

Se estudió, en ratas, el efecto de la hipervitaminosis A aguda sobre el contenido sérico de los elementos sodio, potasio, magnesio, hierro, zinc y cobre. Los resultados se compararon con los obtenidos en animales control o no tratados con vitamina A. En los animales tratados se observó un incremento significativo en el contenido sérico de magnesio, cobre y potasio, y una disminución también significativa, del sodio, hierro y zinc. Se comentan los hallazgos resultantes, sugiriéndose posibles explicaciones para los mismos. Se concluye que ala hipervitaminosis A aguda, directa o indirectamente determina notorias alteraciones en el contenido sérico de los cationes evaluados

Avaliaçäo da exposiçäo profissional a fumos metálicos em operaçöes de solda / Evaluation of the ocupational exposure to metallic fumes in welding

Foi realizada amostragem de fumos metálicos na zona respiratória de quatro de soldadores e em um grupo de prensistas näo expostos a fumos metálicos. As concentraçöes de metais obtidas foram comparadas com os limites de tolerância propostos pela American Conference of Governmental Industrial Hygienists - ACGIH - e adaptados à nossa jornada de trabalho. As concentraçöes encontradas estäo próximas dos limites de tolerância, sendo enfatizada e discutida a dificuldade de decidir se estäo acima ou abaixo do limite. O nível de exposiçäo é comparado com os níveis de metais no sangue e na urina encontrados abaixo dos limites de tolerância biológica. Säo evidenciadas a necessidade de se amostrar o ar dentro do elmo, próximo ao nariz do soldador, e a impraticabilidade de um limite de tolerância gravimétrico único para a presente situaçäo