Dependence of optical attenuation coefficient and mechanical tension of irradiated human cartilage measured by optical coherence tomography.

As banked human tissues are not widely available, the development of new non-destructive and contactless techniques to evaluate the quality of allografts before distribution for transplantation is very important. Also, tissues will be processed accordingly to standard procedures and to minimize disease transmission most tissue banks will include a decontamination or sterilization step such as ionizing radiation. In this work, we present a new method to evaluate the internal structure of frozen or glycerol-processed human cartilages, submitted to various dosis of irradiation, using the total optical attenuation coefficient retrieved from optical coherence tomography (OCT) images. Our results show a close relationship between tensile properties and the total optical attenuation coefficient of cartilages. Therefore, OCT associated with the total optical attenuation coefficient open a new window to evaluate quantitatively biological changes in processed tissues.

Dependence of optical attenuation coefficient and mechanical tension of irradiated human cartilage measured by optical coherence tomography.

As banked human tissues are not widely available, the development of new non-destructive and contactless techniques to evaluate the quality of allografts before distribution for transplantation is very important. Also, tissues will be processed accordingly to standard procedures and to minimize disease transmission most tissue banks will include a decontamination or sterilization step such as ionizing radiation. In this work, we present a new method to evaluate the internal structure of frozen or glycerol processed human cartilages, submitted to various dosis of irradiation, using the total optical attenuation coefficient retrieved from optical coherence tomography (OCT) images. Our results show a close relationship between tensile properties and the total optical attenuation coefficient of cartilages. Therefore, OCT associated with the total optical attenuation coefficient open a new window to evaluate quantitatively biological changes in processed tissues.

Monocyte implication in renal allograft dysfunction.

Macrophages are involved in the development and progression of kidney fibrosis. The aim of this study was to analyse the phenotype of circulating monocytes and their ability to predict kidney allograft dysfunction in living kidney transplant recipients. Whole blood samples from 25 kidney recipients and 17 donors were collected at five time-points. Monocyte phenotype was analysed by flow cytometry, and interleukin (IL)-10 and soluble CD163 by enzyme-linked immunosorbent assay. One week after transplantation, surface CD163 and IL-10 levels increased significantly from baseline [2·99 ± 1·38 mean fluorescence intensity (MFI) to 5·18 ± 2·42 MFI for CD163; 4·5 ± 1·46 pg/ml to 6·7 ± 2·5 pg/ml for IL-10]. This CD163 increase correlated with 4-month creatinine levels (r = 0·4394, P = 0·04). However, soluble CD163 decreased significantly from baseline at 1 week (797·11 ± 340·45 ng/ml to 576·50 ± 293·60 ng/ml). CD14(+) CD16(-) monocytes increased at 4 months and correlated positively with creatinine levels at 12 and 24 months (r = 0·6348, P = 0·002 and r = 0·467, P = 0·028, respectively) and negatively with Modification of Diet in Renal Disease (MDRD) at 12 months (r = 0·6056, P = 0·003). At 4 months, IL-10 decreased significantly (P = 0·008) and correlated positively with creatinine at 2 years (r = 0·68, P = 0·010) and with CD14(+) CD16(-) monocytes at 4 months (r = 0·732, P = 0·004). At 24 h, levels of human leucocyte antigen D-related declined from 12·12 ± 5·99 to 5·21 ± 3·84 and CD86 expression decreased from 2·76 ± 1·08 to 1·87 ± 0·95. Both markers recovered progressively until 12 months, when they decreased again. These results indicate that monitoring monocytes could be a promising new prognostic tool of graft dysfunction in renal transplant patients.

Effects of ionizing radiation and preservation on biomechanical properties of human costal cartilage.

Tissue banks around the world store human cartilage obtained from cadaveric donors for use in diverse reconstructive surgical procedures. To ensure this tissue is sterile at the time of distribution, tissues may be sterilized by ionizing radiation. In this work, we evaluate the physical changes in deep frozen costal cartilage (-70 °C) or costal cartilage preserved in high concentrations of glycerol (>98 %) followed by a terminal sterilization process using ionizing radiation, at 3 different doses (15, 25 and 50 kGy). Tension and compression tests were carried out to determine the mechanical changes related both to the different preservation methods and irradiation doses. For both methods of preservation, tension strength was increased by about 24 %, when cartilage tissue was irradiated with 15 kGy. Deep frozen samples, when irradiated with 25 or 50 kGy, had a decrease in their mechanical performance, albeit to a lesser extent than when tissues were preserved in high concentration of glycerol and equally irradiated. In conclusion, processing in high concentration of glycerol did not increase tissue protection against radiation damage; while cartilage preserved in high concentrations of glycerol withstands radiation up to 25 kGy, deep frozen human costal cartilage may be sterilized with a doses up to 50 kGy without significant mechanical impact.

WT1 mutations may be a cause of severe renal failure due to nephroblastomatosis in Wilms' tumor patients.

Wilms' tumor suppressor gene (WT1) encodes a transcription factor required for normal development of the genitourinary system. Germline WT1 mutations have been described in a wide spectrum of pathological conditions, including kidney diseases, genital abnormalities and Wilms' tumor. Here we report a 4-year-old male patient who presented with bilateral cryptorchidism, Wilms' tumor, nephroblastomatosis and renal failure without nephrotic proteinuria. Sequence analysis of the WT1 gene demonstrated a constitutional heterozygous nonsense mutation in exon 7, which leads to a truncation of the WT1 protein at the zinc-finger 1. In the DNA of the tumor, we observed the same mutation in homo/hemizygosity. Given the requirement of WT1 for normal development, the WT1 mutation is likely to be responsible for the nephroblastomatosis and, in consequence, for the severe renal failure observed in our patient. This finding extends the spectrum of kidney diseases related to WT1 mutations and points to the need to screen for this gene in children with genitourinary abnormalities and Wilms' tumor because of the associated risk of nephroblastomatosis and renal failure in those carrying WT1 mutations.

Preservation of renal function in a patient with Fabry nephropathy on enzyme replacement therapy.

Fabry disease is an X-linked recessive inborn error of glycosphingolipid metabolism caused by the deficient activity of the lysosomal enzyme, alpha-galactosidase A. Enzyme replacement therapy (ERT) for this disorder has been available in Europe since 2001. However, its effect on advanced renal failure remains controversial. We report the case of a patient whose decline in renal function was reduced by the administration of ERT (agalsidase-alpha). This reduction was more pronounced after doubling the dose of the enzyme. The rate of deterioration of eGFR went from 6.3 ml/min/year prior to the start of ERT (0.2 mg/kg) to 2 ml/min/year (0.4 mg/kg). To our knowledge, this is the first reported case of a patient with moderately impaired renal function treated with high doses of ERT and follow-up of 6 years. The data shown here suggest that ERT may have a very positive impact on renal function even in advanced stages. The role of proteinuria and its control seem to have a clear responsibility for this favorable outcome.