Background: Dental personnel is exposed to several potential nephrotoxic agents. Urinary N-acetyl-β-d-glucosaminidase (U-NAG) activity has emerged as a sensitive marker of early nephrotoxicity. Methods: U-NAG was evaluated, by fluorimetric assay, in urine from 30 healthy subjects and 30 dental personnels. Results: The median value of U-NAG activity (133.5 U/mmol urinary creatinine (U-Cr) in urines of dental personnel was not statistically different (P>0.05) from activity (100.7 U/mmol U-Cr) of control urines. Conclusions: The results suggest that, for dental personnel, exposure to potential nephrotoxic agents is not usually high enough to increase U-NAG activity.

Background: Urinary N-acetyl-β-d-glucosaminidase (NAG) activity has emerged as potentially useful early marker of renal tubular injury. This activity is usually evaluated in random urine samples and is related to urinary creatinine concentration. Reports about the lack of correlation between NAG activity of 24-h urines and activity of random urine samples in some clinical and experimental situations led us to study the correlation existing between different procedures for expressing urinary NAG in patients with chronic renal insufficiency. Methods: Thirty samples of 24-h urine and 30 random urine samples from chronic renal insufficiency patients were collected. The activity of urinary NAG was examined fluorimetrically. Results: The following correlations were observed: (1) r=0.431 (P=0.017) for activity in random urine samples and total activity in 24-h urines) ; (2) r=0.281 (P=0.005) for activity in random samples and activity, expressed as U/l, in 24-h urines. Conclusions: The data show that collection of urine excreted over the whole day and evaluation of total daily excretion of NAG seems the method of choice, at least for patients with chronic renal insufficiency.

Physical exercise is known to induce immunological changes, mainly leukocytosis and neutrophil activation. However, it is not known to what extent the leukocytosis, observed after exertion, is associated with an increase in plasma neutrophil elastase, an early marker of inflammatory response and neutrophil degranulation. In the present study changes in circulating leukocyte and neutrophil counts and human neutrophil elastase plasma levels were evaluated in volley-ball players before and after 2 h and 12 h prolonged training, during a competition season. For comparison, the same parameters were evaluated in untrained subjects before and after a jogging session. Basal white blood cell WBC, polymorpho nuclear PMN, and human polymorpho nuclear-elastase PMN-ELA values were within the normal healthy reference range and no significant differences were found between the two groups studied. Venous blood samples of nine volley-ball players showed a statistically significant increase in blood WBCs after 2 h exercise. This effect was paralleled by a statistically significant increase in PMN-ELA concentration compared to the values observed in the same individuals at rest. The exercise did not significantly change the basal correlation parameters between PMN level and PMN-ELA concentration. More pronounced WBC, PMN, and PMN-ELA increases were observed in the seven inactive subjects after 2 h jogging. There was no linear correlation between increased PMN counts and increased PMN-ELA concentrations in untrained subjects after exercise. The results show that not only the leukocyte count but also PMN-ELA plasma levels can be higher after physical effort. This has a practical significance as regards differential diagnosis demonstrating that determination of these two laboratory parameters can give abnormally high values even in the absence of an existing inflammatory process. Besides, lack of correlation between PMN count and PMN-ELA plasma levels in the untrained group suggest a state in which activation of the neutrophils is not connected with their number in peripheral blood.

Lysosomes play an important role in the immune system functioning and are involved in different aspects of inflammatory reaction, repair processes and tissue damage at various levels. Among various effects, it is known that physical exercise influences the release of different lysosomal components. The aim of this study was to evaluate enzyme activity and isoenzymatic profile of β-N-acetylhexosaminidase both in kidney and urine of normal and trained rats. Enzyme activity was measured by fluorimetric assay while β-N-acetylhexosaminidase isoenzymes were separated using DEAE-cellulose chromatography. Hexosaminidase specific activity was significantly increased in urine of trained rats whereas there was no increase in the kidneys of trained rats. Indeed, no significant differences were observed in the isoenzyme profile of kidney and urine extracts from normal and trained rats. Our findings suggest the exercise-induced release of lysosomal enzymes is a functional effect and not due to disruption of lysosomal membranes.

The urinary excretion of N-acetyl-beta-D-glucosaminidase (U-NAG) and urinary Cadmium (U-Cd) concentration, a measure of the metal load in the body, were evaluated in 28 workers exposed to Cd, to determine the relation between the two parameters. In urine from 22 exposed workers with U-Cd < 2 mu g/g creatinine (Cr) there was no significant difference in U-NAG value (0.98 +/- 0.59 U/gCr) compared to non-exposed (0.73 +/- 0.48 U/gCr). In the six workers with 2 mu g/gCr less than or equal to U-Cd < 10 mu g/gCr the U-NAG (2.32 +/- 0.61 U/gCr) was statistically (P < 0.05) higher than in other workers. In both the U-Cd intervals examined there were no altered values of beta 2-microglobulin From urine of exposed workers compared to non-exposed (<0.30 mg/l). The U-NAG isoenzymes were separated by DEAE-cellulose chromatography from urine of non-exposed subjects and exposed workers. The U-NAG isoenzyme profile in urine of non-exposed subjects showed a high percentage (about 95%) of the A (acid) form, a much lower percentage (about 4.5%) of B (basic) form and a negligible percentage (about 0.5%) of I (intermediate) form. In the urine of 22 exposed workers with U-Cd < 2 mu g/gCr, the percentages of U-NAG isoenzymes were not different from non-exposed. In the urine of six workers with 2 mu g/gCr less than or equal to U-Cd < 10 mu g/gCr the percentage (8.34 +/- 0.91) of isoenzyme B (U-NAG-B), a marker of lesional enzymuria, was statistically increased (P < 0.05) compared to non-exposed (4.42 +/- 0.56). These results suggest that adopting a biological limit for U-Cd equal to 10 mu g/gCr might not be sufficiently protective. The increase tubule caused by the metal which might follow an induction of the apoptotic process. (C) 2000 Elsevier Science B.V. All rights reserved.

BACKGROUND:The presence in saliva of cotinine, the main and inactive metabolite of nicotine, reflects the extent of systemic distribution of nicotine and explains the increased susceptibility to periodontal disease in smokers. The aim of this study was to investigate the comparative amount of cotinine in the saliva of habitual cigarette smokers, non-smokers and passive smokers.METHODS:Saliva sample were obtained from 14 cigarette smokers and 13 non-smokers (8 passive-smokers), all without periodontal disease, and analyzed by Microplate EIA (a variation of ELISA based on cross-reactivity of cotinine with anti-cotinine antibody revealed by absorbance in spectrophotometry) to determine the presence and the amount of cotinine.RESULTS:Cotinine was detected in the saliva of smokers with a mean of 92.3 +/- 4.15 ng/ml and, unexpectedly, there was evidence of cotinine also in the saliva of non-smokers (mean 5.4 +/- 1.22 ng/ml), particularly, in passive-smokers (mean 12.9 +/- 6.67 ng/ml).CONCLUSIONS:The salivary concentration of cotinine can be used to estimate nicotine intake and its possible role in the pathogenesis of periodontal disease also in passive-smokers.

The activity of β-hexosaminidase, determined with 4-methylumbelliferyl-β-N-acetylglucopyranoside substrate, and of β-d-mannosidase was significantly higher in the serum of patients with carbohydrate-deficient glycoprotein (CDG) syndrome type IA (phosphomannomutase deficiency) than in controls. No significant differences were observed in the activity of β-hexosaminidase, determined using 4-methylumbelliferyl-β-N-acetylglucopyranoside-6-sulphate as substrate, and the activity of α-d-mannosidase. Using DEAE-cellulose chromatography, a greater amount of hexosaminidase B than hexosaminidase A was detected in CDG serum. In CDG serum, hexosaminidase A was eluted in a more basic position in the salt gradient. An isoenzyme of α-d-mannosidase and β-d-mannosidase was identified in control and CDG sera. α-d-Mannosidase isoenzyme was eluted in a slightly more basic position in CDG serum than in control serum, whereas β-d-mannosidase isoenzyme was eluted in the same position.

Overtraining syndrome strikes those athletes subjected to loads greater than their ability to recover. It is a serious pathology, above all for duration of the symptoms which prevents normal training and favours "staleness", a psychophysical emptying syndrome. Precocious alterations in mood permit one to diagnose the overtraining syndrome which may come before the physical damages. Today the hypothesis that, at the base of this pathology there could be oxidative stress with production of mitochondrial superoxide caused by overtraining is gaining ground. Even though direct administration of antioxidants supplementation cannot cure the pathology, preventive increase of the body's antioxidant capacity could perhaps be the most effective therapy for the overtraining syndrome.

Specific activities of β-d-hexosaminidase, α-d-mannosidase, β-d-galactosidase and β-d-glucuronidase were determined in fibroblasts of patients with writer’s cramp and torticollis. These diseases show degenerative neurological disorders similar to those observed in lysosomal diseases. Hexosaminidase specific activities, determined using 4-methylumbelliferyl-β-N-acetylglucopyranoside and 4-methylumbelliferyl-β-N-acetylglucopyranoside-6-sulphate as substrates, were significantly higher in the fibroblasts of patients than in controls. No significant differences were observed in the specific activities of the other lysosomal enzymes. The increased hexosaminidase specific activities in torticollis and writer’s cramp may be additional markers for these diseases.

Beta-N-acetylhexosaminidase is expressed as a single protein in Trichinella spiralis and has catalytic properties similar to the alpha- and beta-subunits of human and mouse isoenzymes A and B. It can hydrolyze the artificial substrates, 4-methylumbelliferyl-beta-D-glucosamine and 4-methylumbelliferyl-beta-D-glucosamine-6-sulphate which are respectively hydrolyzed by the beta- and alpha-subunits. The enzyme is thermostable, has a basic isoelectric point, and thus is similar to the B isoenzyme. Northern blotting experiments indicate that the enzyme is encoded by a single gene. Hexosaminidase from Trichinella spiralis shows that the substrate specificities of alpha- and beta-subunits precede the duplication of their genes.

beta-Hexosaminidase isoenzymes were separated by DEAE-cellulose chromatography in the serum of 23 patients infected with human immunodeficiency virus at different stage of the disease. Forms corresponding to hexosaminidase B, I and A were present in pathological sera. There is an increase in the percentage of hexosaminidase I in pathological sera, that could be used as an additional marker to monitor the clinical stage of the disease. Furthermore, total activities of some lysosomal enzymes were determined in these sera. Activities of beta-hexosaminidase, determined with 4-methylumbelliferyl-beta-N-acetylglucopyranoside substrate, alpha-mannosidase and beta-mannosidase were significantly higher in the serum of patients at the C3 stage of disease than in controls. No significant differences were observed in the activity of beta-hexosaminidase, determined with 4-methylumbelliferyl-beta-N-acetylglucopyranoside-6-sulphate substrate, beta-glucuronidase and beta-galactosidase.

Cytidine 5-diphosphocholine (CDP-choline) administration has been shown to improve learning and memory deficits in different models of brain disorders. In this study, effects of CDP-choline on the well known negative effects of Rapid Eye Movements (REM) sleep deprivation on learning and memory were investigated. Sleep deprivation was induced by placing adult male Wistar albino rats on 6.5 cm diameter platforms individually for 96 h according to flower pot method. Learning and memory performances were evaluated using Morris Water Maze (MWM) test during the same period of time. Saline or CDP-choline (100 µmol/kg, 300 µmol/kg or 600 µmol/kg) was administered intraperitoneally 30 min prior to the onset of MWM experiments. On completion of behavioral tests, rats were decapitated and hippocampi were assayed for total and phosphorylated Ca2+/calmodulin-dependent protein kinase II (tCaMKII and pCaMKII, respectively) and total antioxidant capacity. We observed that while REM sleep deprivation had no effect on learning, it diminished the memory function, which was associated with decreased levels of pCaMKII and total antioxidant capacity in the hippocampus. CDP-choline treatment blocked the impairment in memory function of sleep-deprived rats and, increased pCaMKII levels and total antioxidant capacity. These data suggest that CDP-choline reduces REM sleep deprivation-induced impairment in memory, at least in part, by counteracting the disturbances in biochemical and molecular biological parameters.

The head-down suspension (i.e antiorthostatic hypokinesia) rat is used to simulate weightlessness. However, little is known about cardiovascular and organ adaptation responses which, over a long time, can become pathologically significant. The purpose of this study was therefore to evaluate regional changes in the hematology parameters, Endotheline-1 (ET-1) concentration and urinary excretion of N-acetyl-β-D-glucosaminidase (EC 3.2.1.30) (NAG) in an experimental antiorthostatic rat model. The data indicate significant variations in the plasma ET-1 level in time, in the superior and inferior cava vessel blood of animals maintained for 10 days in hypogravity with respect to controls. These changes do not seem to be due to hemoconcentration. The increase in urinary NAG was observed during the first 24h of experiment, indicating renal stress, probably due to adverse blood flow variations within the organ. We conclude that the plasma ET-1 level changes could be responsible, overall for the blood flow variations in the kidney and renal stress could be the consequence of extended antiorthostatic hypokinesia. The ET-1 behaviour and urinary NAG excretion in rats exposed to antiorthostatic hypokjnetic hydynamia offer possibilities for understanding if these changes might be reversible or when they become pathological. This could give some relevant information about the effects of prolonged hypogravity during the space voyage.

A study was carried out to evaluate whether football, involving young players aged between 13-14 years old, might represent a psychophysical stress leading to significant variations in the urinary enzyme P-NAG. This enzyme has all the characteristics required by urinary enzymes in order to be used for diagnostic purposes. Earlier studies have shown that the urinary enzyme P-NAG is more accurate than traditional systems such as urinary protein assay, creatinine clearence, etc., in detecting renal damage. A group of 18 athletes aged between 13-14 years old were included in the study which was performed during a national tournament; assays were made during basal conditions and after exercise. The technique consisted in the collection of 36 urinary samples: 18 (basal samples) collected within one hour of the start of the match and 18 (post-exercise samples) collected whithin 30 minutes of the end of the match. Ail samples were collected mid-flow. A non-statistically significant increase in the enzyme was found during the post-exercise phase. This supports the hypothesis that the young age of players and the type of physical activity are not sufficient to cause modifications in renal function. Altered renal function has been hypothesised in adults performing an intense physical activity, like the biathlon, linked to a transient condition of renal hypoxia probably due to hematic involvement ranging from the renal to muscular district during exercise.

beta-N-Acetylhexosaminidase isoenzymes were separated from the kidney, serum and urine of normal mice and mice intoxicated with bromobenzene, using DEAE-cellulose chromatography. Both mouse serum and urine showed hexosaminidase profiles similar to the human counterparts with the presence of B (basic), I (intermediate) and A (acidic) isoenzymes. A notable feature was the presence of a high proportion of an intermediate form in mouse urine which is not always present in human urine. Hexosaminidase activity increased significantly in urine of mice intoxicated with bromobenzene. Its increase was time-dependent and due to kidney damage with a release in the urine of hexosaminidase A, I and, in higher proportion, B. No significant differences were observed in mouse kidney and serum profiles following intoxication with bromobenzene. The total activity of hexosaminidase, using 4-methylumbelliferyl-2-acetamido-2-deoxy-beta-D-glucopyranoside as substrate, did not increase in the serum of mice intoxicated with bromobenzene. Both hexosaminidase activity and the isoenzyme pattern in urine can be used as indicators of kidney damage by bromobenzene intoxication.

We investigated the kinetics of antibodies detected by indirect hemagglutination (IHA), IgE Elisa and immunoelectrophoresis (IEP) in patients with hydatid disease operated on and continuously followed in the pre-operative and post-operative periods. In the pre-operative phase the IgE Elisa test was found to be adequately sensitive (68.4%) compared with IHA (79%), with a ratio of IgE Elisa/IHA positivity of 87%, while IEP was positive in 55.3% of cases (IEP/IHA ratio=70%).During post-operative follow-up IHA became negative late in patients who were cured (7 out of 11 were still positive after 4 yrs), whereas IEP and IgE Elisa became negative within 2 yrs of operation (apart from 1 patient with a persisting positive IgE Elisa 3 yrs later).However, IgE Elisa appeared clearly more sensitive in revealing postoperative recurrences (13 out of 13 patients had positive IgE Elisa, vs. 6 out of 13 IEP).