An HNF4α-microRNA-194/192 signaling axis maintains hepatic cell function.

Hepatocyte nuclear factor 4α (HNF4α) controls the expression of liver-specific protein-coding genes. However, some microRNAs are also modulated by HNF4α, and it is not known whether they are direct targets of HNF4α and whether they influence hepatic function. In this study, we found that HNF4α regulates microRNAs, indicated by marked down-regulation of miR-194 and miR-192 (miR-194/192) in liver-specific Hnf4a-null (Hnf4aΔH) mice. Transactivation of the shared miR-194/192 promoter was dependent on HNF4α expression, indicating that miR-194/192 is a target gene of HNF4α. Screening of potential mRNAs targeted by miR-194/192 revealed that expression of genes involved in glucose metabolism (glycogenin 1 (Gyg1)), cell adhesion and migration (activated leukocyte cell adhesion molecule (Alcam)), tumorigenesis and tumor progression (Rap2b and epiregulin (Ereg)), protein SUMOylation (Sumo2), epigenetic regulation (Setd5 and Cullin 4B (Cln4b)), and the epithelial-mesenchymal transition (moesin (Msn)) was up-regulated in Hnf4aΔH mice. Moreover, we also found that miR-194/192 binds the 3'-UTR of these mRNAs. siRNA knockdown of HNF4α suppressed miR-194/192 expression in human hepatocellular carcinoma (HCC) cells and resulted in up-regulation of their mRNA targets. Inhibition and overexpression experiments with miR-194/192 revealed that Gyg1, Setd5, Sumo2, Cln4b, and Rap2b are miR-194 targets, whereas Ereg, Alcam, and Msn are miR-192 targets. These findings reveal a novel HNF4α network controlled by miR-194/192 that may play a critical role in maintaining the hepatocyte-differentiated state by inhibiting expression of genes involved in dedifferentiation and tumorigenesis. These insights may contribute to the development of diagnostic markers for early HCC detection, and targeting of the miR-194/192 pathway could be useful for managing HCC.

Experience of bone bridge resection and bone wax packing for partial growth arrest of distal tibia.

Two patients with a partial growth arrest of the distal tibia were treated by bone bridge resection and bone wax packing technique. Their average age at the time of surgery was 7 years, both had been injured in an accident, and each had been treated with percutaneous pinning and a plaster cast. Unfortunately, partial growth arrest of the distal tibia occurred, and the ankle varus deformity gradually progressed. About 1 year after initial treatment, bone bridge resection and bone wax packing were performed. The average follow-up period was 80 months. There was no reformation of the bone bridge or recurrence of deformity, and gradual improvements in clinical and radiographic findings were observed. Although fat is typically used as an interpositional material after bone bridge resection, there are problems with its use, including a lack of hemostasis and the absence of intrinsic stability. Bone wax is readily available and commonly used in medical applications to control bleeding. It is considered a useful plug, it is inexpensive, and it is not associated with complications.

Outcomes of new pogo-stick brace for Legg-Calvé-Perthes' disease.

In 1992, the authors developed a non-weightbearing unilateral ambulatory hip abduction brace, which was named the new pogo-stick brace for unilateral Legg-Calve -Perthes' disease. The hip abduction angle of the new pogo-stick brace was adjustable 45 degrees . The advantage of this brace was that even in the sitting position, the hip abduction angle was maintained. Twenty patients were treated with unilateral LCPD using the new pogo-stick brace. In the Catterall classification, one patient was classified as group 2, 17 as group 3, two as group 4. In Herring classification, one patient was classified as group A, 17 as group B, two as group C. Ultrasonography was performed to determine containment of the hip joints, and the abduction angle of the new pogo-stick brace was adjusted to get better containment, every 2 months. Mose's and acetabular head index methods were used for radiographic evaluation, and classified into good, fair and poor groups both at the primary healing and at the final follow-up. Total evaluation was defined as worse group between Mose's method and acetabular head index method. The average time from onset of disease to the primary healing was 25 months. The average bracing period was 21 months. The average follow-up period was 94 months. At the final follow-up appointment, patients who were classified into good and fair groups were 85% in Mose's method, 95% in acetabular head index method, 85% in total evaluation. In Stulberg classification, the total number of patients who were classified into classes I and II was 85%. The outcome of the new pogo-stick brace was not worse than that of any other treatment method, and was better than that of other unilateral ambulatory braces.

Incidence of physeal injuries in Japanese children.

Although epidemiological studies on epiphyseal injury have been reported, such studies have not been made systematically in Japan. In this study, we examined the incidence of epiphyseal injury in paediatric patients treated at five general hospitals and three private clinics. We treated the patients with limb injuries between January 1992 and December 1997, and reviewed them at least 18 months after the original injuries. The original radiograms and the completed case records were classified according to age and sex of the injured children, site of the fracture, type of treatment, and its complications. Epiphyseal injuries accounted for 17.9% of all paediatric fractures. The most frequently injured epiphysis was the phalanges of hands, 21.9% of all physeal injuries. Salter-Harris type I accounted for 28.6% of physeal injuries; type II (60.9%) revealed the largest number of cases in this study, compared with type III (6.7%) and type IV (3.7%). Type V was not recognized. Most physeal injuries were treated conservatively. Either weight-bearing joints or elbow joints were treated surgically. Complications of physeal injuries were seen in seven cases. Five cases involved the upper limb, and the other two cases involve the lower limb. Although deformity or malfunction caused by physeal injuries was remained, only one case needed a corrective osteotomy. Other six cases revealed a fair prognosis.

Effects of alternating current electrical stimulation on lengthening callus.

Limb lengthening by the callotasis method has been clinically applied to patients who suffered from limb length inequality, micromelia, angular deformation and partial bone defect on long bones. However, this technique was time consuming and led to various complications, such as infection at the pin insertion sites, limitation of the range of motion in adjacent joints, muscular weakness and peripheral neuroparalysis. This study was undertaken to investigate whether alternating current electric (AC) stimulation could shorten the maturation period during callotasis. The tibiae of 20 immature male Japanese white rabbits were osteotomized and fixed with external lengthener (Orthofix M100; Orthofix Srl, Bussolengo, Italy). The experimental schedule lasted 5 weeks consisting of 1 week for the latency period, 2 weeks for distraction and 2 weeks for maturation. Twenty rabbits were equally divided into two groups: the control group and the electrical stimulation (ES) group. The control group was not stimulated with an AC stimulator. The ES group was stimulated for 5 weeks just after osteotomy. The obtained results revealed radiologically, electrophysiologically and histologically that AC stimulation accelerated the maturation of lengthened callus and that it could shorten the time course of callus lengthening.

Usefulness of epiphyseal quotient measurement on magnetic resonance images for outcome prediction in patients with early-stage Legg-Calve-Perthes disease.

To investigate the usefulness of epiphyseal quotient (EQ) measurement for outcome prediction in patients with Legg-Calve-Perthes disease (LCPD), magnetic resonance (MR) imaging was performed in 26 patients with unilateral LCPD within 6 months of the disease onset and subsequently once every 3 months. All the patients were treated conservatively in our institute between 1990 and 1999. The mean follow-up period was 80 months. Clinical outcome was evaluated based on the plain radiograms of the femoral head at the final examination according to Stulberg's classification: the patients whose outcome was class I were regarded as 'excellent' (excellent group), class II as 'good' (good group), and classes III, IV and V as 'poor' (poor group). The excellent group consisted of 10 patients, the good group of 12, and the poor group of four. The EQ measured on MR images (MR-EQ) decreased remarkably in the poor group chronologically, whereas there was no decrease in the excellent group and a slow decrease in the good group. The mean MR-EQ at or before the sixth month (range, 2-6 months; mean, 4.9 months) was 86.2 (range, 76.8-94.8) in the excellent group, 78.3 (57.0-93.4) in the good group, and 67.4 (57.8-74.5) in the poor group (P<0.05 among the three groups). According to our results, because all patients having an MR-EQ at or before the sixth month of 75 or higher were classified in the excellent or good groups, it is thought that the ongoing method of treatment can be continued. On the other hand, since half of the patients having an MR-EQ at or before the sixth month of lower than 75 were classified in the poor group and had a high potential for a poor outcome, it is thought that these patients require strict containment therapy, and altering the surgical procedure could be considered depending on the particular patient. It was thought that the MR-EQ is a useful predictive factor of LCPD prognosis.