Reference genes for proximal femoral epiphysiolysis expression studies in broilers cartilage.

The use of reference genes is required for relative quantification in gene expression analysis and the stability of these genes can be variable depending on the experimental design. Therefore, it is indispensable to test the reliability of endogenous genes previously to their use. This study evaluated nine candidate reference genes to select the most stable genes to be used as reference in gene expression studies with the femoral cartilage of normal and epiphysiolysis-affected broilers. The femur articular cartilage of 29 male broilers with 35 days of age was collected, frozen and further submitted to RNA extraction and quantitative PCR (qPCR) analysis. The candidate reference genes evaluated were GAPDH, HMBS, HPRT1, MRPS27, MRPS30, RPL30, RPL4, RPL5, and RPLP1. For the gene stability evaluation, three software were used: GeNorm, BestKeeper and NormFinder, and a global ranking was generated using the function RankAggreg. In this study, the RPLP1 and RPL5 were the most reliable endogenous genes being recommended for expression studies with femur cartilage in broilers with epiphysiolysis and possible other femur anomalies.

Gene expression in slipped capital femoral epiphysis. Evaluation with laser capture microdissection and quantitative reverse transcription-polymerase chain reaction.

BACKGROUND: Slipped capital femoral epiphysis is a poorly understood condition affecting adolescents. Prior studies have suggested that the etiology may be related to abnormal collagen in the growth plate cartilage, but we are not aware of any investigations analyzing collagen or other structural proteins on a molecular level in the affected tissue. This study was performed to evaluate expression of mRNA for key structural molecules in growth plate chondrocytes of patients with slipped capital femoral epiphysis. METHODS: A core biopsy of the proximal femoral physis was performed in nine patients with slipped capital femoral epiphysis, and the specimens were compared with five specimens from the normal distal femoral and proximal tibial and fibular physes of age-matched patients treated surgically for a limb-length inequality. We utilized laser capture microdissection techniques followed by quantitative reverse transcription-polymerase chain reaction analysis to determine if a change or abnormality in type-II-collagen and/or aggrecan gene expression may be associated with slipped capital femoral epiphysis. With these techniques, we correlated chondrocyte spatial location and gene expression to provide greater insight into this pathological condition and a more complete understanding of growth plate biology in general. RESULTS: Downregulation of both type-II collagen and aggrecan was found in the growth plates of the subjects with slipped capital femoral epiphysis when compared with the levels in the age-matched controls. In eight specimens from affected patients, the level of expression of type-II-collagen mRNA was, on the average (and standard error of the mean), 13.7% +/- 0.2% of that in four control specimens and the aggrecan level averaged only 26% +/- 0.2% of the control aggrecan level. CONCLUSIONS: The decreases that we identified in type-II-collagen and aggrecan expression would affect the quantity, distribution, and organization of both components in a growth plate, but these changes could be associated with either the cause or the result of a slipped capital femoral epiphysis.

Slipped capital femoral epiphysis: physeal histologic features before and after fixation.

Physeal histopathologic changes following slipped capital femoral epiphysis (SCFE) are usually considered permanent. This assumption may not be correct, since radiographic signs of proximal femoral neck growth and remodeling are commonly seen after fixation. This work analyzed the physeal histologic features of chondroepiphyseal biopsies before and after SCFE surgical fixation but before complete physiologic epiphysiodesis. Eighteen patients, nine with unstable and nine with stable SCFE of varying severity, had pretreatment biopsies. Three patients had postfixation biopsies prior to total physiologic proximal femoral epiphysiodesis. Pretreatment biopsies showed varied degrees of histoarchitectural changes ranging from almost normal arrangement to markedly deranged physeal morphology. Postfixation biopsies showed improved physeal organization in a case of moderate unstable SCFE. In one severe unstable case and one severe stable case, nearly normal physeal architecture was seen. Physeal histopathologic changes appear to improve after fixation. Progressive modulation of the recovering physis after fixation helps explain the remodeling and growth changes seen radiographically after chondroepiphyseal fixation.

Iliac crest growth plate analysis in slipped capital femoral epiphysis.

Previous studies have demonstrated numerous histologic and histochemical abnormalities in the involved growth plate of patients with slipped capital femoral epiphysis (SCFE). Whether these changes are primary or secondary with regard to the slip is unknown. We examined an uninvolved site of patients with SCFE and controls, the iliac crest growth plate, by histochemical means for general morphology, proteoglycans, glycoproteins, and collagen fibril orientation. No differences were noted between the two groups studied. This observation suggests that previously reported slipped capital femoral epiphyseal abnormalities may be a result of, rather than a cause of, the slip in this condition.

Hormone status in patients with slipped capital femoral epiphysis.

In 15 consecutive patients with slipped capital femoral epiphysis we recorded height, weight and skeletal maturity. Sexual maturity was assessed clinically and biochemically, and Harris's hypothesis that there is an increased ratio of serum growth hormone to oestrogen was tested in comparison with 15 age and sex matched controls. We found no difference in skeletal or sexual maturity between the groups, or any overt endocrine abnormality in the patients. However almost half the patients with slipped epiphysis were over the 90th weight percentile, suggesting that mechanical factors such as obesity are more important aetiologically than endocrine abnormalities.

Hormonal studies in patients with slipped capital femoral epiphysis without evidence of endocrinopathy.

In a prospective study, plasma levels of T3, T4, thyroid stimulating hormone (TSH), cortisol, testosterone, growth hormone, and somatomedin-C were tested in 20 consecutive adolescent patients with slipped capital femoral epiphysis (SCFE) in an effort to identify any occult endocrinopathy. All patients had the clinical diagnosis of SCFE confirmed on radiographs. The patients were examined by the pediatric endocrinology service and were without clinical evidence of an endocrinopathy. Of 140 hormonal determinations only four different patients had four abnormal values. Routine sampling of these hormones in patients without clinical evidence of endocrinopathy is not indicated.

Slipped capital femoral epiphysis: a pathological study. I. A light microscopic and histochemical study of 21 cases.

Core biopsy specimens of slipped proximal femoral epiphyseal growth plates and of normal controls were examined by light microscopy and histochemistry. Slipped growth plates showed diminished cellularity with an overall excess of matrix as well as severe disorientation and misalignment of chondrocytes. Decrease in number of argyrophilic fibers in the longitudinal septa suggested deficiency in collagen. Histochemical staining of slipped plates did not deviate from normal except in severely deformed areas. Anatomic and histochemical observations did not conclusively support or exclude biochemical or biomechanical factors in the etiology of epiphyseal slipping.

Endocrinologic and metabolic factors in atypical presentations of slipped capital femoral epiphysis. Report of four cases and review of the literature.

Although the usual etiology of slipped capital femoral epiphysis (SCFE) is idiopathic, there are many underlying endocrinologic, biomechanical, metabolic, and connective tissue abnormalities that increase the predisposition to slippage. Four case reports and a review of the literature demonstrate tht hypopituitarism, renal rickets, radiation therapy, hypoestrogenic states, and chemotherapy can be associated with SCFE. Awareness of the variety of conditions under which SCFE can occur is an important factor in providing early diagnosis, since many patients undergo slippage at atypical ages. In metabolically and endocrinologically abnormal patients, surgical stabilization may need to be augmented by autologous bone grafting to ensure successful epiphyseodesis.

A histochemical study of slipped capital femoral epiphysis.

UNLABELLED: Core biopsies of the proximal femoral growth plate from three patients with slipped capital femoral epiphysis were compared with three normal growth plates from patients of similar ages. The growth plates of patients with slipped capital femoral epiphysis had a normal resting zone, a loose and fibrillated proliferative zone, and a very disarranged and thickened hypertrophic zone. The proliferative zone stained strongly with alcian blue, suggesting the presence of abundant proteoglycans in the cartilage matrix. The thickened hypertrophic zone was strongly positive to periodic acid-Schiff stain, indicating the presence of abundant structural glycoproteins. Enchondral ossification was scanty and irregular, and there were large clusters of cartilage in the metaphysis. Slippage occurred through the thickened proliferative and hypertrophic zones. CLINICAL RELEVANCE: The proximal femoral growth plate in slipped capital femoral epiphysis is histochemically abnormal and histologically disarranged. These features contribute to abnormal widening of the growth plate and to further slippage.

Bilateral slipped upper femoral epiphysis: a rare manifestation of renal osteodystrophy. Case report with discussion of its pathogenesis.

Bilateral slipped upper femoral epiphysis is a rare manifestation of renal osteodystrophy. A case of bilateral slipped femoral epiphysis in an 18-year old male suffering from chronic renal failure due to oligomeganephronic renal hypoplasia with profound signs of renal osteodystrophy is presented. Serum growth hormone levels were high, while those of urinary 17-ketosteroids were decreased. Following subtotal parathyroidectomy, the progression of the process leading to slipped epiphysis was halted with closure of the epiphyses. The patient was subsequently treated with chronic hemodialysis for several months, after which successful renal transplantation was performed. The pathogenesis of renal osteodystrophy leading to slipped epiphysis is discussed and attention drawn to the fact that bilateral slipped femoral epiphysis may be the first clinical sign of chronic renal insufficiency.