The clinical value of urinary N-acetyl-beta-D-glucosaminidase levels in childhood age group.

N-acetyl-beta-D-glucosaminidase is a high molecular-weight lysosomal enzyme found in many tissues of the body. It cannot pass into glomerular ultrafiltrate due to its high molecular weight. However, this enzyme shows high activity in renal proximal tubular cells, and leaks into the tubular fluid as the ultrafiltrate passes through proximal tubules. When proximal tubular cells are injured due to to any disease process including glomerular proteinuria, nephrolithiasis, hyperglycemia, interstitial nephritis, transplant rejection or nephrotoxic agents such as antibiotics, antiepileptics, or radiocontrast agents, its urine level increases and thus is used as a reflection of proximal tubular cell necrosis. However, the clinical use of urinary N-acetyl-beta-D-glucosaminidase determination is limited in childhood because of certain technical problems. In addition, the urinary level of this enzyme changes with the maturational level of proximal tubular cells. Thus, difficulties are involved in assessing normal urine levels of this enzyme for age. On the other hand, successive measurements of urinary N-acetyl-beta-D-glucosaminidase during the longitudinal follow-up of the patients may enhance its clinical use as an indicator of ongoing tubular injury.</p

An 11-Year-Old Child with Autosomal Dominant Polycystic Kidney Disease Who Presented with Nephrolithiasis

Patients with autosomal dominant polycystic kidney disease become symptomatic and are diagnosed usually at adulthood. The rate of nephrolithiasis in these patients is 5–10 times the rate in the general population, and both anatomic and metabolic abnormalities play role in the formation of renal stones. However, nephrolithiasis is rare in childhood age group. In this paper, an 11-year-old child with autosomal dominant polycystic kidney disease presenting with nephrolithiasis is discussed

The role of L-carnitine in treatment of a murine model of asthma.

Leukotrienes, one of the mediators of inflammation in asthma, have a strong bronchoconstrictive effect. L-carnitine has been reported to influence respiratory functions. It has also been reported that L-carnitine inhibits leukotriene synthesis. To evaluate the effects of L-carnitine on oxygen saturation, urine leukotriene E4 levels and lung histopathology in a murine model of asthma, high IgE responder BALB/c mice (n = 24) were systemically sensitized to ovalbumin and chronically challenged with low particle mass concentrations of aerosolized ovalbumin, and then they were divided into 3 groups (study groups A, B, and C) each including eight mice. After methacholine-induced bronchoconstriction, the mice in groups A and B were given intraperitoneal L-carnitine (250 and 125 mg/kg, respectively), while the mice in group C were given placebo. Oxygen saturation of the mice was measured by pulse oxymeter before and after methacholine and after L-carnitine/ placebo application. In addition, urine leukotriene E4 levels were measured before asthma development, and 24-h after L-carnitine injection in asthmatic mice. Inflammation in the lung tissues of the sacrificed animals was scored histopathologically to determine the effect of L-carnitine on tissue level. A control group of non-sensitized mice (n = 8) treated with placebo only was used for comparison of urine leukotriene E4 levels and of histopathological parameters. Oxygen saturation of the mice in the study groups tended to decrease after methacholine and to improve after L-carnitine injection, although these changes were not significant at all time points. Urine leukotriene E4 levels of all 3 study groups increased significantly after asthma development. The rate of increment was smallest in the group given the highest L-carnitine dose (group A). Inflammation at the tissue level was also mildest in group A, and severest in the group that was not given carnitine (group C). All of the study groups and the control group differed significantly with respect to inflammation scores. In conclusion, L-carnitine improved oxygen saturation, and decreased urine leukotriene E4 levels and inflammation in lung tissues in the present murine model of asthma.</p

A 12-Year-Old Girl with Bilateral Coats Disease and ABCA4 Gene Mutation

A 12-year-old girl with bilateral stage 2B Coats disease was screened meticulously for a possible underlying systemic disease as she was female and the disease was bilateral. Full systemic workout turned out to be unremarkable. However, an ABCA4 gene mutation was found in the genetic analysis. NDP and TINF2 gene mutations were not present. She was successfully treated with a bilateral, single intravitreal injection of dexamethasone implant and a single session of indirect laser photocoagulation with a relatively good anatomic and functional result. To the best of our knowledge, the present case is the only reported case of Coats disease with an ABCA4 gene mutation