Multinucleated podocytes as a clue to diagnosis of juvenile nephropathic cystinosis

BACKGROUND  : Cystinosis is a rare autosomal recessive lysosomal disorder that mainly affects the kidney and eye. Early treatment with cysteamine significantly improves the prognosis. However, early diagnosis of cystinosis, especially the juvenile nephropathic form, remains challenging because typical symptoms only become apparent in adulthood. We herein describe a 13-year-old girl who presented with proteinuria only but was diagnosed with juvenile nephropathic cystinosis based on multinucleated podocytes in her kidney biopsy specimen. We also studied the nephropathology of another case to determine the features of the multinucleated podocytes. CASE DIAGNOSIS: A previously healthy 13-year-old girl presented to our hospital because proteinuria had been detected in her school urine screening. She had been noted to have proteinuria on her school urine screening when she was 11 years of age but there was no consultation with her physician at that time. She was asymptomatic and had no other abnormalities on examination other than a relatively high urinary β-2 microglobulin level. Her kidney biopsy showed 15 multinucleated podocytes in 34 glomeruli, and the mean number of nuclei per multinucleated podocyte was 4.4. Ophthalmological examination showed cystine crystals in her cornea. Her white blood cell cystine level was high, and she was diagnosed with juvenile nephropathic cystinosis. She started oral cysteamine treatment and showed almost no progression of the disease after 2 years. In another patient with juvenile nephropathic cystinosis, there were 25 multinucleated podocytes in 63 glomeruli, and the mean number of nuclei per multinucleated podocyte was 2.9. CONCLUSION: Early diagnosis is crucial to improve the prognosis of patients with cystinosis. This report emphasizes the importance of recognizing the unique pathological feature of multinucleated podocytes as an essential clue to the diagnosis of cystinosis.

Half of children with IgA vasculitis-associated nephritis with nephrotic state spontaneously recover

BACKGROUND

The clinical spectrum of Henoch-Schönlein purpura nephritis (HSPN), now known as IgA vasculitis-associated nephritis (IgAVN), ranges from isolated microscopic haematuria to nephrotic syndrome, progressive glomerulonephritis, and kidney failure. The outcome also varies, and the management of IgAVN is controversial. The presence of nephrotic state at disease onset is thought to be a risk factor of a poor prognosis. However, not all patients with nephrotic state have a poor prognosis, and it is unclear whether they need early treatment.

METHODS

We herein retrospectively examined the clinical course of paediatric IgAVN cases with nephrotic state (serum albumin [sAlb]<3.0g/dL and urine protein-creatinine ratio of >2.0 g/ gCr) without kidney injury treated at our hospital between 2010 and 2018.

RESULTS

Of the 216 patients with IgAVN identified, 17 met the inclusion criteria. The median follow-up period from disease onset to the last observation was 40.5 months (IQR:31.0-74.2). Eleven patients were male, the median age at onset was 5 years, the minimum serum Alb level was 1.9 g/dL, the maximum proteinuria value was 12.3 g/gCr, and the median minimum eGFR was 86.0 mL/min/1.73 m² in the acute phase. Eight patients (47%) achieved resolution of nephrotic state within three months and complete remission without treatment by the last observation. The patients with spontaneous resolution of nephrotic state had less severe hypoalbuminaemia (Alb<2.0g/dL) and tended to show a quick increase in the serum albumin level.

CONCLUSIONS

Our study found that half of paediatric patients with IgAVN with nephrotic state achieved spontaneous resolution without treatment and enjoyed a favorable short-term outcome. Consideration of the duration of nephrotic state and trends in the serum albumin level in children with IgAVN may allow unnecessary kidney biopsies and immunosuppressive therapy to be avoided. This article is protected by copyright. All rights reserved.

Investigation of a colloidal damper

A novel application of nanotechnology in the field of mechanical engineering, called colloidal damper (CD), is investigated. This device is complementary to the hydraulic damper (HD), having a cylinder-piston construction. Particularly for CD, the hydraulic oil is replaced by a colloidal suspension, which consists of a mesoporous matrix and a lyophobic fluid. In this work, the porous matrix is from silica gel modified by linear chains of n-alkylchlorosilanes and water is considered as an associated working fluid. A design solution from a practical point of view of the CD test rig and the measuring technique of the hysteresis are described. A brief review of the water physical properties relative to the CD concept is presented. Influence of the bonding density, length of the grafted molecule, pore diameter, and particle diameter on the CD hysteresis is investigated for distinctive types and mixtures of silica gels. Temperature variation during functioning is recorded and the CD cycle is interpreted from a thermodynamic standpoint. Variation of the CD dissipated energy and efficiency with pressure, water quantity, and relaxation time is illustrated. Experimental results are justified by the analysis of the water flow into the porous matrix, CD thermodynamics, and the mechanism of the energy dissipation. Our findings agree with the previously published data.

TEM Investigation and Electron Diffraction Study on Dispersion of Gold Nanoparticles into a Nylon 11 Thin Film during Heat Treatment

We have investigated the effect of heat treatment on the changes in the microstructure of nylon 11 thin films containing nanosized Au particles by means of lateral and cross-sectional transmission electron microscopy. It was observed that, on heat treatment, the Au islandlike particles initially deposited on the nylon 11 surface penetrated into the polymer layer to form a composite film consisting of nanosized spherical Au particles dispersed in a polymer matrix, while the initially amorphous nylon 11 matrix crystallized to the alpha-crystalline form. The surface stress coefficient of the Au particles, calculated from the lattice constant determined by the electron diffraction patterns, decreased as the Au particles penetrated into the polymer matrix, which can be due to both coalescence of the particles to a spherical shape and reduction of the surface free energy of the particles by embedding in the matrix. The molecular chain motion of the nylon 11 matrix during the crystallization process is suggested to be responsible for the dispersion of Au particles into the polymer matrix. Copyright 1999 Academic Press.

Novel Method for Preparation of a Nanosized Gold Catalyst Supported on TiO2

A TiO2 surface was readily modified with nanosized gold particles prepared by the thermal relaxation technique. Adsorption of the gold particles was very rapid, and the adsorbed gold particles distributed independently. By the two-step calcination of the modified TiO2, the nanosized gold particles were immobilized on the TiO2 surface without size growth or coagulation. The supported gold particles showed low-temperature catalytic activity on CO oxidation. The preprepared nanosized gold particles interacted with TiO2. Copyright 1999 Academic Press.