N-acetyl-B-D-glucosaminidase isoenzymes in the diagnosis of poisoning and kidney diseases

Lead and cognitive function in ALAD genotypes in the third National Health and Nutrition Examination Survey

The relationship between the blood lead concentration and cognitive function in children and adults with different ALAD genotypes who participated in the third National Health and Nutrition Examination Survey was investigated. The relationship between blood lead and serum homocysteine concentrations was also investigated. In children 12 to 16 years old, no difference in the relationship between cognitive function and blood lead concentration between genotypes was found. In adults 20 to 59 years old, mean reaction time decreased as the blood lead concentration increased in the ALAD rs1800435 CC/CG group. This represents an improvement in performance. In adults 60 years and older, no difference in the relationship between cognitive function and blood lead concentration between genotypes was found. The serum homocysteine concentration increased as the blood lead concentration increased in adults 20 to 59 years old and 60 years and older, but there were no differences between genotypes. The mean blood lead concentration of children with the ALAD rs1800435 CC/CG genotype was less than that of children with the GG genotype.

Interactions between thyroid and kidney function in pathological conditions of these organ systems: a review

Thyroidal status affects kidney function already in the embryonic stage. Thyroid hormones influence general tissue growth as well as tubular functions, electrolyte handling and neural input. Hyper- and hypo-functioning of the thyroid influences mature kidney function indirectly by affecting the cardiovascular system and the renal blood flow, and directly by affecting glomerular filtration, electrolyte pumps, the secretory and absorptive capacity of the tubuli, and the structure of the kidney. Hyperthyroidism accelerates several physiologic processes, a fact which is reflected in the decreased systemic vascular resistance, increased cardiac output (CO), increased renal blood flow (RBF), hypertrophic and hyperplastic tubuli, and increased glomerular filtration rate (GFR). Renal failure can progress due to glomerulosclerosis, proteinuria and oxidative stress. Hypothyroidism has a more negative influence on kidney function. Peripheral vascular resistance is increased with intrarenal vasoconstriction, and CO is decreased, causing decreased RBF. The influence on the different tubular functions is modest, although the transport capacity is below normal. The GFR is decreased up to 40% in hypothyroid humans. Despite the negative influences on glomerular and tubular kidney function, a hypothyroid state has been described as beneficial in kidney disease. Kidney disease is associated with decreased thyroid hormone concentrations caused by central effects and by changes in peripheral hormone metabolism and thyroid hormone binding proteins. Geriatric cats form an animal model of disease because both hyperthyroidism and chronic kidney disease (CKD) have high prevalence among them, and the link between thyroid and kidney affects the evaluation of clinical wellbeing and the possible treatment options.

Enzymuria and beta2-mikroglobulinuria in the assessment of the influence of proteinuria on the progression of glomerulopathies

The important role of the tubulo-interstitial system for the progression of glomerulonephritis (GN), is the cause of a continuous search for the proper markers of kidney tubules damage, which can be applied in clinical diagnosis. In the present work the activity of N-acetyl-beta-D-glucosamidase (NAG), its isoenzyme NAG-B, alanylaminopeptidase (AAP), gamma-glutamyltransferase (GGT), concentration of beta2-microglobulin (beta2M) and daily protein excretion in the urine of 37 patients with morphologically different glomerulopathies were measured. The serum creatinine was also controlled. The obtained results suggest that activity of NAG in the patients with GN has an intermediate connection with proteinuria and could be a cause of the inflammatory process of the kidney, but the activity of AAP is directly dependent on urine protein concentration. Systemic analysis of both partial and multiple correlation coefficients of the examined indicators creates new, additional possibilities in the estimation of activity and progress of GN.

Enzymatic markers of cyclosporine nephrotoxicity in patients after renal transplantation

Toxicity of cyclosporine (CsA), an immunosuppressive drug widely used in transplantation, to the transplanted kidney creates a serious side effect. Therefore, searching for sensitive indicators of nephrotoxic action is well worth the effort. In this work we describe the results of estimation of urine concentration of lysosomal enzymes widely present in the kidney: N-acetyl-beta-D-glucosaminidase (NAG), its isoenzyme NAG-B and beta-glucuronidase (beta-Gr). The studies were conducted in various periods after transplantation of kidneys, on patients under various treatments and receiving different doses of CsA. The results indicate a substantial dependence of the activity of NAG and NAG-B on CsA doses and the period after transplantation. The enzyme proved to be also a sensitive indicator of graft rejection. No such dependence was observed in the case of beta-Gr.

Pneumoperitoneum produces reversible renal dysfunction in animals with normal and chronically reduced renal function

Laparoscopic surgery with intraperitoneal insufflation is associated with acute oliguria. Although in healthy patients, this impairment is transient and without any apparent sequelae, as the scope of laparoscopic surgery expands, subtle renal injury may become clinically significant, particularly when applications expand to patients with reduced baseline renal function. We have investigated the changes in renal function during and after pneumoperitoneum in animals with reduced renal mass to identify both acute alterations and long-term impairments, if any. Twelve swine underwent surgical reduction in renal mass to produce chronic renal insufficiency. Glomerular filtration rate (GFR) was determined by inulin clearance for each animal before and after ablation to establish the degree of renal impairment (mean 22%; range 18%-31% of normal). The animals were followed during a stepwise insufflation as a study of pneumoperitoneum-induced changes in chronic renal failure. Urine output declined dramatically (-80% at 20 mm Hg), the GFR fell (-63% at 20 mm Hg), and renal blood flow declined (mean -12%; range -9% to -19%) over the course of the test. These values did not return to baseline during a 90-minute observation period after release of the pneumoperitoneum. Acute renal failure occurred despite aggressive hydration with maintenance of central venous pressure and only modest changes in cardiac output. The animals were exposed to a 6-hour CO2 pneumoperitoneum to 20 mm Hg to model the insult of complex laparoscopy. This exposure resulted in elevation of the amount of N-methyl-beta-D-glucosaminidase being shed into the urine in addition to the previously indicated impairments. The animals were allowed to recover for 1 week, and then GFR was again measured. The GFR returned to the preexposure chronic renal failure levels for both the group as a whole and individual animals. The magnitude and duration of the alteration in urine output, GFR, and renal blood flow suggest that regulatory mechanisms rather than simple mechanical forces are involved in the acute changes. No long-term impact on renal function from the acute renal injury was identified, even in animals with existing renal insufficiency.

Ethylene glycol poisoning: case report of a record-high level and a review

Ethylene glycol is commonly found in automobile antifreeze and a variety of other commercial products. Ingestion of ethylene glycol, either accidentally or in a suicide attempt, is characterized by severe acidosis, calcium oxalate crystal formation and deposition, and a wide variety of end organ effects that may be fatal. We present a case of a patient who ingested a massive amount of ethylene glycol in a suicide attempt and yet survived with minimal sequelae. A comprehensive review of the literature on the pathology and pathophysiology of ethylene glycol toxicity on each organ system is provided, along with information on diagnosis and current treatment recommendations.