Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026916 (MAC)
 5,226 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a metallurgic plant we analysed blood samples, urine and finger-nails of 54 workers exposed to vanadium. On the basis of orientating dust measurements it can be assumed that the results obtained were, as a rule, clearly lower than the MAC values for vanadium pentoxide dust. The median vanadium concentration in whole-blood was 2.9 micrograms/l. This indicates that the exposed persons differ significantly from the control group. The median vanadium concentration measured in urine was 37.8 micrograms/l. This means that there is a significant difference in comparison with the control group (0.8 micrograms/l). In order to obtain values of greater reliability, the vanadium concentration resulting from the analysis of spontaneous urine samples was to be referred to the creatinine content. Conversion yields a medium vanadium concentration of 33.9 and 0.6 micrograms/g creatinine for the exposed workers and normal persons respectively. The cystine content found in the finger-nails of persons occupationally exposed to vanadium was significantly reduced with respect to the comparative group (8.9 against 9.9 mg cystine per 100 mg finger-nails). Within the groups of persons examined no correlation is found to exist between the cystine content of the finger-nails and the age of the persons, nor between the vanadium concentrations in blood and urine. After a weekend without exposure the vanadium concentrations in blood and urine dropped. In general, this drop was the more pronounced the higher the initial value was. Roughly two to four days after the occupational exposure had ceased, the values dropped to the half of the initial value. Based on the test results available, the vanadium concentrations in blood and urine reflect the extent of an occupational vanadium exposure and are suitable indicators for estimating the potential threat caused by this heavy metal.
 ...
PMID:[Field tests carried out to determine the occupational exposure to vanadium (author's transl)]. 48 17

Twenty-seven patients without renal disease were divided randomly into three groups of each nine patients. Each group received either enflurane, isoflurane or sevoflurane. The renal tubular functions were examined during anesthesia and on the first postoperative day. By inhalation of 1.49 MAC hours of enflurane, 2.17 MAC hours of isoflurane or 1.29 MAC hours of sevoflurane, creatinine clearance, Na excretion rate, urine beta 2-microglobulin and urine N-acetyl-beta-D-glucosaminidase showed no significant changes during anesthesia and the during postoperative period among anesthetic agents used. These results indicate that enflurane, isoflurane or sevoflurane does not affect renal tubular function specifically under anesthesia when each was given for less than four hours.
 ...
PMID:[Effects of enflurane, isoflurane, and sevoflurane on renal tubular functions]. 146 Jul 50

We examined the potential toxicity of desflurane in 13 young 25.0 +/- 2.3 (mean +/- SD) yr-old men, given 7.35 +/- 0.81 MAC-hours of desflurane anesthesia. Hepatic and renal function tests, serum electrolytes, and standard urine and hematologic tests were performed before, during, and after anesthesia. No toxicity was found. There were no changes in tests of hepatocellular integrity (plasma alanine transferase activity), synthetic function (serum albumin, prothrombin time, partial thromboplastin time), or renal function (serum creatinine concentration, blood urea nitrogen concentration). Decreases in red blood cell count, hematocrit, and blood hemoglobin concentration during and immediately after anesthesia were attributed to blood sampling and infusion of intravenous electrolyte solution. These values returned by 4 days after anesthesia to values not different from those before anesthesia. Increased white blood cell counts and blood glucose concentrations noted during anesthesia with other inhaled anesthetics were also seen in these volunteers. Desflurane appears to have no greater toxicity than currently used inhaled anesthetics and, because of its lesser metabolism, may have lesser or not toxicity.
 ...
PMID:Desflurane does not produce hepatic or renal injury in human volunteers. 155 24

Serum inorganic fluoride concentrations were studied in 19 adult patients undergoing prolonged head and neck surgery with either halothane or isoflurane anesthesia (mean 19.5 and 19.2 MAC-hours, respectively). In the group of nine patients anesthetized with isoflurane, plasma inorganic fluoride increased from a mean concentration of 3.5 mumols/L (baseline) to a peak of 43.2 mumols/L. Forty percent of the patients in the isoflurane group had peak plasma inorganic fluoride concentrations of more than 50 mumol/L. In the group that received halothane, plasma inorganic fluoride concentrations increased from a mean of 3.8 mumols/L to a peak of 12.6 mumols/L. Despite similar exposures to both anesthetics, the differences in serum inorganic fluoride concentrations between the two groups were significant at 10, 24, and 48 h after induction of anesthesia (P = 0.035, P = 0.003, and P = 0.003, respectively). Serum electrolyte, urea, and creatinine concentrations and urine output rates during and after surgery were similar in both groups. We conclude that, after anesthesia of up to 20 MAC-hours, metabolism of isoflurane to inorganic fluoride may be of a greater magnitude than has previously been realized. Although no clinical or biochemical evidence was found to suggest postoperative renal dysfunction, we recommend caution using isoflurane when prolonged anesthesia and surgery are planned.
 ...
PMID:Plasma fluoride concentrations during and after prolonged anesthesia: a comparison of halothane and isoflurane. 173 43

In passive or active Heymann nephritis (HN) in the rat, the immune complexes that form in the glomerular subepithelial space result in complement activation and the urinary (U) excretion of S protein-membrane attack complex (SC5b-9, MAC). Because of the similarities between HN in rats and membranous nephropathy (MN) in humans, it has been suggested that measurement of SC5b-9 in urine (UMAC) could be useful in assessing the immunologic activity of MN in patients. The present study was undertaken in normal individuals and in patients with nephrotic syndrome to determine: 1) the conditions of urine collection and preservation needed for accurate measurement of UMAC for clinical purposes; and 2) whether UMAC levels are a sensitive and/or specific test for MN. In studies conducted on urine specimens from patients with increased UMAC levels, we found that UMAC in freshly voided urine was stable for at least three hours at 37 degrees C, with or without the addition of the enzyme inhibitors that were used to stabilize UMAC levels in the studies of HN in the rat. Urine pH, leukocytes and erythrocytes, over the ranges usually encountered, did not influence UMAC levels. However, freezing urine at -70 degrees C artifactually raised UMAC levels (1500 +/- 550 to 1800 +/- 580 SE ng/ml, P less than 0.001 by paired t-test). Normal urine contained low UMAC levels: 80 +/- 3 ng/mg urinary creatinine (UCr). By contrast, patients with glomerulopathies tended to have elevated UMAC levels: 18 of 38 patients had levels that ranged from 200 to 20,000 ng/mg UCr.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Measurement of SC5b-9 in urine in patients with the nephrotic syndrome. 176 15

To assess the potential for producing nephrotoxicity in rats with abnormal renal function, the renal effects of enflurane or halothane anesthesia, 1 MAC for two hours, were examined in six groups of six Fischer 344 rats each with surgically induced chronic renal impairment. As an additional predisposing factor, gentamicin, 5 mg/kg/day, was administered for one week before and for one week after anesthesia to three of the groups, one anesthetized with enflurane, one anesthetized with halothane, and one unanesthetized. No significant change in renal function could be attributed to either anesthetic agent. Serum inorganic fluoride levels four hours and 24 hours after enflurane anesthesia were similar in the gentamicin-treated and the non-gentamicin-treated groups. Clinically small but statistically significant increases in serum creatinine concentration and urinary flow occurred in all three gentamicin-treated groups during the period of treatment. Anesthesia with either enflurane or halothane in rats with chronic renal impairment treated with gentamicin did not result in additional renal damage.
 ...
PMID:Renal function in Fischer 344 rats with chronic renal impairment after administration of enflurane and gentamicin. 745 64

Carbon disulfide (CS2) exposure was assessed in several ways in a viscose fiber plant. Environmental exposure was measured by static area sampling and by personal monitoring using diffusive passive ORSA-5 Draeger badges. At the same time, as biological indicators of exposure the iodine-azide test (IAT) and 2-thiothiazolidine-4-carboxylic acid (TTCA) in urine samples obtained at the end of work shift were performed. The aim was to estimate the relationship between parameters of environmental exposure and biological indicators of internal exposure as well as to determine the influence of the exposure duration on urinary TTCA values. Environmental exposure determined by personal samplers as time-weighted average (TWA) concentrations was twice as high than when measured by static area sampling: 62.2 vs. 31.1 mg/m3 in the spinning rooms, and 18.3 vs 12.2 mg/m3 in the viscose manufacturing departments. The iodine-azide test showed high linear correlation with CS2, but only for very high CS2 values. In highly exposed spinners, higher urinary TTCA levels were found related to longer exposure to CS2, but without statistical significance. For TTCA levels in urine a high correlation coefficient existed, but in this case even for low CS2 levels. Using a linear regression equation, a biological limit value for TTCA which corresponds to the Yugoslav MAC of 30 mg/m3 for CS2 was calculated (9.89 mg/g creatinine) for the study population, which is higher than in other investigations.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Environmental and biological monitoring in carbon disulfide exposure assessment. 817 32

We investigated the factors which may influence post-operative liver and renal function using a multiple regression analysis after isoflurane or sevoflurane anesthesia in 844 patients (ASA I or II, age 20-90 yr). Hepatic and renal surgeries were excluded from this study. The parameters examined were sex, age, degree of obesity, preoperative liver function, preoperative renal function, infection with hepatitis B or hepatitis C virus, inhalation anesthetics used, MAC.h of anesthesia, the duration of operation, blood loss, amount of blood transfusion, urine volume during operation, and surgical site. Serum GOT, GPT, total bilirubin, BUN and serum creatinine were examined on the 3rd and 7th day after surgery. An increase in serum GOT, GPT or bilirubin was observed for each of the following parameters; male, infection with hepatitis C virus, long operation, and upper abdominal surgery. Postoperative BUN and serum creatinine increased in patients with preoperative renal dysfunction, in elderly patients, and in hepatitis C carriers.
 ...
PMID:[Multiple regression analysis of pre- and intra-operative factors in relation to post-operative liver and renal functions]. 854 85

Patients with epilepsy on long term antiepileptic drug (AED) therapy deserve special consideration not only concerning seizure control but also the effect on anaesthetic metabolism and hepatorenal functions. In the present study, we examined the effects of sevoflurane anaesthesia on plasma inorganic fluoride (F-) level and hepatorenal function in patients with and without AED therapy. Twenty-two patients (12 with AEDs = AED group, and ten without AEDs = control group = C group), ASA I, who were free of hepatorenal disease, received approximately 2-3 h sevoflurane anaesthesia. Plasma F- analysis was performed at the stages of: 1) induction of anaesthesia, 2) conclusion of anaesthesia, 3) 15 h after the conclusion of anaesthesia, using an ion-selective electrode calibrated with a standard solution of sodium fluoride. Pre- and postoperative hepatic (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin) and renal (blood urea nitrogen, creatinine) function was tested. There were no significant differences between the two groups in the average age (AED group = 9.4 and control group = 10.1 y.o.), body weight, duration of anesthesia, and MAC hours (2.6 and 2.4). The mean peak F- levels were 15.5 and 13.6 microM, in AED and C groups (not significant), respectively. No patient exhibited F- values greater than 50 microM, the hypothetical nephrotoxic threshold. The patients showed no abnormal values either in hepatic or renal function tests postoperatively. These results suggest approximately 2-3 h sevoflurane anaesthesia to be safe in patients taking AEDs.
 ...
PMID:Clinical characteristics and biotransformation of sevoflurane in paediatric patients during antiepileptic drug therapy. 888 Aug 18

Increased levels of Cr discharged with urine after working shift, Cr-U (arithmetic mean 15.8 mu g/g creatinine), and Cr buildup during working shift, DeltaCr-U (arithmetic mean 3.8 mu g/g creatinine), were observed in 15 MMA/SS welders exposed during the working week to welding fumes containing Cr VI (33-56%) - mainly soluble (87%) and Cr III (44-67%) - mainly insoluble (72%). The highest correlation coefficients were obtained for DeltaCr-U vs. Cr total (r = 0.58), Cr VI (r = 0.56) and soluble Cr III in the air. Increased DeltaCr-U value for exposures at MAC Cr VI (16.8 mu g/g creatinine) was demonstrated in welders employed longer than 7 years and exposed to Cr VI below MAC level, which might suggest that the duration of employment affects that value within the low range of concentration of Cr VI in the air (< 0.03 mg/m3). Nevertheless, linear relationship between DeltaCr-U for exposures to Cr VI at MAC levels and duration of employment was not confirmed for wide range of air Cr VI (0.005-0.4 mg/m3). Similar DeltaCr-U values at MAC for Cr VI (6.4 and 6.6 mu g/g creatinine) were obtained for all welders, and those employed over 7 years, respectively, which may suggest that this parameter can be misleading.
 ...
PMID:Urinary excretion of chromium as an indicator of exposure to various chromium forms in MMA/SS welders. 890 8


1 2 Next >>