Urinary beta-hexosaminidase excretion in patients treated with lithium, thymoleptic and/or neuroleptic drugs

Right Atrial Deformation Using Cardiovascular Magnetic Resonance Myocardial Feature Tracking Compared with Two-Dimensional Speckle Tracking Echocardiography in Healthy Volunteers

Speckle tracking echocardiography (STE), and more recently, cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) provides insight into all phases of atrial function. The aim of our study was to compare all phases of RA strain using CMR-FT and STE and also assess the relationship between RA and LA strain. A total of 61 healthy volunteers with mean age of 45 ± 13 years had adequate tracking for analysis on CMR-FT and 2D-STE. Females had larger RA reservoir strain (39 ± 15% vs. 32 ± 13%, p = 0.046) and conduit strain (26 ± 12% vs. 20 ± 9%, p = 0.03) when compared to males, but was not the case with booster strain (14 ± 7% vs. 12 ± 6%, p = 0.45). In comparison with STE derived strain, the RA reservoir and conduit strain were not significantly different between CMR-FT and the three echocardiography gating methods (p > 0.05 for all). Noticeably, there were no significant differences in strain and strain rate between RA and LA function using CMR-FT (p > 0.05 for all). RA strain and strain rate using CMR-FT had fair and good intra- and inter-observer reproducibility and had superior reproducibility compared to STE derived strain.

Increased hexosaminidase activity in antipsychotic-induced extrapyramidal side effects: possible association with higher occurrence in bipolar disorder patients

Dystonic movements and Parkinsonism are frequently seen in gangliosidoses and these conditions have been reported to modify dopaminergic plasticity. We investigated whether the activity of hexosaminidase, a type-two ganglioside (GM2) degrading enzyme, correlates with drug-induced extrapyramidal system (EPS) side effects in psychiatric patients. We compared hexosaminidase activity in the lymphocytes of 29 EPS-positive patients, 13 EPS-negative patients, and 30 healthy volunteers. The activities of A and B isoforms of hexosaminidase were higher in EPS-positive patients than EPS-negative patients and healthy controls. Multivariate analysis suggested an interaction with increased B isoform activity and EPS side effects in female bipolar disorder patients. Higher levels of hexosaminidase enzyme activity may explain the frequent occurrence of antipsychotic-induced extrapyramidal side effects in mood disorder patients.

Association of levels of N-acetyl-beta-glucosaminidase with specific psychiatric symptoms in bipolar patients

The levels of N-acetyl-beta-glucosaminidase (NAG) in urine from 35 patients with bipolar affective disorder were compared with scores for the 90 items (symptoms) of the Symptom Checklist (SCL-90). There were significant negative correlations between NAG levels and 23 of the SCL-90 variables (symptoms). These symptoms could be grouped into the following categories: anxiety, unusual or psychotic thinking, suicidal thinking, dysphoria, irritability, nausea, headaches, memory problems, and loss of interest. Serotonin abnormalities may play a role in the production of many of these symptoms. The hypothesis that NAG could be a marker for a serotonin activity is discussed.

Effects of sulindac and naproxen on prostaglandin excretion in patients with impaired renal function and rheumatoid arthritis

PURPOSE

The purpose of the current investigation was to study the influence of sulindac and naproxen on renal function and urinary excretion of the stable hydration product of prostacyclin, 6-keto-PGF1 alpha, in patients with arthritis and impaired renal function.

PATIENTS AND METHODS

In a placebo-controlled, double-blind, cross-over design, the effects of 7 days of oral sulindac 200 mg twice a day were compared with naproxen 500 mg in the morning and 250 mg in the evening in 10 patients with polyarthritis and stable impaired renal function. Inulin and para-amino-hippurate sodium were used to calculate glomerular filtration rate and renal plasma flow. The excretion rate of 6-keto-PGF1 alpha was measured in urine collected overnight. After patients ingested drugs in the morning, urine was collected in fractions by spontaneous voiding. Venous blood samples were drawn repeatedly for assay of electrolytes, creatinine, proteins, hormones, and drugs. Grip strength and Ritchie articular index were recorded as indicators of symptomatic antiarthritic effectiveness.

RESULTS

Naproxen decreased urine levels of 6-keto PGF1 alpha by 59% (p less than 0.01). Sulindac had no effect on renal prostaglandin excretion. Naproxen reduced the glomerular filtration rate and renal plasma flow by 18% (p less than 0.05) and 13% (p less than 0.05), respectively, while no significant change was observed during the sulindac treatment periods. Serum levels of creatinine and complement factor D were unaffected by either drug. Plasma renin activity decreased during naproxen and sulindac treatments by 38% (p less than 0.05) and 22% (p less than 0.05). No significant change in plasma aldosterone was observed during the two drug treatments, but urinary aldosterone declined significantly (p less than 0.05) by 34% with naproxen. Albuminuria decreased (p less than 0.05) during both naproxen (41%) and sulindac treatment (72%), while the albumin/creatinine clearance ratio decreased by 59% (p less than 0.05) only during treatment with sulindac. N-acetyl-beta-D-glucosaminidase in urine was not changed by either drug. Sulindac and naproxen had no discernible effects on base excess, excretion of water, sodium, or potassium, or on osmolal clearance. However, serum potassium increased slightly but significantly (p less than 0.01) during treatment with naproxen. Sulindac sulfide, the active metabolite of sulindac, could not be traced in the urine from any of the patients. Mean arterial blood pressure declined significantly (p less than 0.05) during sulindac treatment but did not change during treatment with naproxen. Both drugs produced equal clinical improvement as measured by grip strength and the Ritchie articular index.

CONCLUSION

The results suggest that when sulindac and naproxen are given in clinical equipotent doses to patients with impaired renal function, sulindac does not affect renal prostaglandin synthesis or renal function, whereas naproxen induces suppression of renal prostaglandin synthesis and a further decrease in renal function.

Elevated levels of N-acetyl-beta-glucosaminidase in affective disorders and chemical dependence

Levels of N-acetyl-beta-glucosaminidase (NAG) were examined in 575 patients with various psychiatric diagnoses and 38 non-ill controls. Ten percent of affectively disordered patients and 19% of chemically dependent patients had abnormal NAG levels, whereas none of the 38 controls did (P less than 0.05 and P less than 0.003 respectively). Other psychiatric diagnostic groups were not associated with abnormal levels of this enzyme.

Enzymuria in workers exposed to inorganic mercury

Urinary excretion of beta-hexosaminidase (NAG = N-acetyl-beta-glucosaminidase) and albumin was examined in 41 chlor-alkali workers exposed to inorganic mercury and 41 age-matched controls. Either U-HG or B-Hg levels for these workers were available dating from the 1960s to the present. Increased U-NAG was seen in workers with a U-Hg today of more than 4 micrograms/mmol creat (about 50 micrograms/l: 35 ug/g creat). Multiple linear regression analysis showed that U-NAG was correlated to U-Hg and integrated dose but not to the present B-Hg level. No albuminuria (detection limit 12.5 mg/l) was found in any of the subjects. In a longitudinal study, no decrease in U-NAG levels was seen in 15 chlor-alkali workers after their vacation (means = 20d). In five workers followed for ten months after a short exposure period, no definite time trend could be seen. The results show that there is a slight effect on renal tubules even at rather low levels of exposure to mercury vapour. The clinical significance of the enzymuria levels found here is, however, debatable.

Elevation of the renal enzyme N-acetyl-beta-glucosaminidase in affectively disordered patients

A minority of patients with affective disorders experience mild elevations of the renal enzyme N-acetyl-beta-glucosaminidase (NAG). Some affectively disordered patients also have reduced concentrating ability and reduced creatinine clearance. Thirty-one affectively disordered patients were compared to 17 healthy controls, to evaluate whether these various renal abnormalities are associated with one another and to further examine the proportion of affectively disordered patients experiencing NAG elevations. Twenty-nine percent of patients had an elevated NAG, whereas none of the controls did (P less than .005). There was a trend for an association between elevated NAGs and reduced creatinine clearance (P less than .08), but no association was found between concentrating ability and either elevated NAG or reduced creatinine clearance.

Neuroleptics, lithium and renal function

Renal function test results in 26 patients on neuroleptic treatment, who had never received lithium or antidepressants, were compared with those in a matched group, treated with lithium; also, their tubular response to DDAVP was compared with that of 25 control subjects. Measurements of serum creatinine, creatinine clearance, and urinary albumin excretion showed no abnormality attributable to either neuroleptics or lithium. The maximum urine concentrating ability after DDAVP was significantly lower in the neuroleptic group than in controls, but significantly higher than in the lithium-treated patients. There was a significant correlation between excretion of urinary beta 2-microglobulin and duration of neuroleptic treatment, but mean excretion rates were the same in both treatment groups. The results suggest that neuroleptics as well as lithium impair urine concentrating ability.