FISH and PRINS: competing or complementary technologies?

Urinary connective tissue growth factor increases far earlier than histopathological damage and functional deterioration in early chronic renal allograft injury

OBJECTIVE

To date, serum biochemistry examination and routine biopsy are the most commonly used methods to assess renal function after allogenic kidney transplantation. Connective tissue growth factor (CTGF) has been considered as a biomarker of chronic renal allograft injury characterized by tubular atrophy and interstitial fibrosis (TA/IF). This study explored the potential value of urinary CTGF as an early predictor of TA/IF using a rat model.

MATERIAL AND METHODS

A Fisher to Lewis allogenic rat kidney transplant model was established and the recipients were killed at weeks 4, 8 and 12 post-transplantation. TA/IF was graded based on Banff Schema 1997. The location and expression of CTGF mRNA were detected by oligonucleotide-primed in situ DNA synthesis and quantitative polymerase chain reaction. CTGF protein expression was examined with immunohistochemistry and immunoblotting. Urinary CTGF concentration was measured by enzyme-linked immunosorbent assay. The correlation between urinary CTGF concentration and serum creatinine (SCr) and Banff score was analysed statistically.

RESULTS

Typical morphological changes including TA/IF in allograft appeared at week 8 and became very severe at week 12 post-transplantation. CTGF expression in epithelium was up-regulated early and urinary CTGF was markedly elevated from week 4. SCr in recipients was stable before week 8 but increased tremendously at week 12. Urinary CTGF concentration was positively correlated with SCr and degree of interstitial fibrosis.

CONCLUSION

Urinary CTGF increases earlier than the appearance of biochemical abnormalities and pathological changes. Measurement of urinary CTGF may offer a potential non-invasive strategy to predict the early onset of chronic renal allograft injury.

Fast multicolor primed in situ protocol for chromosome identification in isolated cells may be used for human oocytes and polar bodies

OBJECTIVE

To present and evaluate the use of a new ultra-fast multicolor primed in situ (PRINS) procedure for karyotyping human oocytes and first polar bodies.

DESIGN

In situ chromosomal identification on isolated cells, using combinations of specific primers for chromosomes 1, 7, 9, 16, and 18 and fluorescent nucleotides.

SETTING

Sixteen unfertilized oocytes were obtained from women participating in an IVF program.

PATIENT(S)

Five patients undergoing an IVF-ET.

INTERVENTION(S)

In vitro unfertilized oocytes were fixed on slides, and sequential PRINS reactions were performed on each preparation.

MAIN OUTCOME MEASURE(S)

Ultrarapid in situ identification of three or four chromosomes on oocyte and polar body chromosome spreads.

RESULT(S)

On the basis of the direct in situ mixing of the colors of fluorochromes (FITC, TRITC, Cascade Blue) that were incorporated in sequential PRINS reactions, this method allows rapid and efficient labeling of three or four individual chromosomes. Each PRINS reaction consists of a unique 4- to 6-minute step for both in situ annealing and elongation. The procedure can be combined with fluorescence in situ hybridization (FISH) reactions.

CONCLUSION(S)

By simplifying the multicolor PRINS procedure, this new protocol should facilitate the use and adaptation of PRINS to chromosome screening. This approach could be used in parallel or in combination with FISH for efficient aneuploidy assessment on isolated cells.