Increased expression of EGR1 and KLF4 by polysulfide via activation of the ERK1/2 and ERK5 pathways in cultured intestinal epithelial cells.

Sodium trisulfide (Na2S3) releases hydrogen polysulfide (H2Sn) and is useful for the investigation of the effects of H2Sn on the cell functions. In the present study, we first examined the effects of Na2S3 on the gene expression of IEC-6 cells, a rat intestinal epithelial cell line. Microarray analysis and reverse transcription-polymerase chain reaction analysis revealed that Na2S3 increased the gene expression of early growth response 1 (EGR1) and Kruppel-like transcription factor 4 (KLF4). It was interesting that U0126, an inhibitor of the activation of extracellular signal-regulated kinase 1 (ERK1), ERK2, and ERK5, inhibited the Na2S3-induced gene expression of EGR1 and KLF4. Na2S3 activated ERK1 and ERK2 (ERK1/2) within 15 min. In addition to ERK1/2, Na2S3 activated ERK5. We noticed that the electrophoretic mobility of ERK5 was decreased after Na2S3 treatment. Phos-tag analysis and in vitro dephosphorylation of the cell extracts indicated that the gel-shift of ERK5 was due to its phosphorylation. The gel-shift of ERK5 was inhibited completely by both U0126 and ERK5-IN-1, a specific inhibitor of ERK5. From these results, we concluded that the gel-shift of ERK5 was induced through autophosphorylation by activated ERK5 after Na2S3 treatment. The present study suggested that H2Sn affected various functions of intestinal epithelial cells through the activation of the ERK1/2 and ERK5 pathways.

Clinical and radiographic evaluation of total hip arthroplasties using porous tantalum modular acetabular components: 5-year follow-up of clinical trial.

OBJECTIVES: Porous tantalum is a biomaterial newly applied for artificial joints. We present here 5-years follow-up report of a multicenter clinical trial of total hip arthroplasties (THA) with porous tantalum modular acetabular component (modular PTC). METHODS: Study participants received 82 hips in 79 cases, with 61.2 months follow-up on average. Age at operation was 60.9 years. Clinical results were evaluated using Merle d'Aubigne Postel score. Presence of implant loosening, periacetabular radiolucency, osteolysis, and gap filling were examined for radiographic results. RESULTS: Merle d'Aubigne Postel score improved from 10.0 to 16.4 points. All PTC were radiographically stable, with no evidence of progressive radiolucencies. Average polyethylene wear rate was 0.004 mm/year, with no periacetabular osteolysis. Fifteen hips (18.3%) showed a gap >1 mm; however, all showed bone filling within 12 months. PTC with oversized reaming was significantly less likely to have a gap. No implant failure was noted related to modularity. Resulting survival rate of modular PTC was 100% at 5 years. CONCLUSIONS: Modular PTC showed excellent results at 5-years of follow-up. Some hips showed periacetabular gaps, which were filled with bone within 1 year. Further follow-up was needed to determine long-term efficacy.

Epidemiology of hip fractures in Okinawa, Japan.

This study investigated the current incidence of hip fractures in Okinawa prefecture and compared the data with those obtained in our previous study, which was conducted using similar methods in 1987/1988. All patients, aged 50 years or older and residing in Okinawa, admitted to Okinawa hospitals in 2004 for a fresh hip fracture were identified from hospital registries. Details were obtained from the medical records and radiographs of all patients and classified according to fracture type (cervical or trochanteric), age, sex, and fracture location. Subtrochanteric fractures and pathological fractures were excluded. A total of 1,349 patients (242 men and 1,107 women) were admitted for a fresh hip fracture in 2004. Their average age was 76.9 years for men and 82.4 years for women. There were 671 cervical fractures, 654 trochanteric fractures, and 24 unclassified proximal femoral fractures. Comparing the data from 1987/1988 to those from 2004, the total number of hip fractures increased by 188%, from 469 to 1,349. The age-adjusted incidence rates per 100,000, standardized to the 2000 US population, were 75.7 and 296.1 in 1987/1988 and 123.6 and 420 in 2004 for men and women, respectively. The incidence rates in all age groups (at 5-year intervals) were higher in 2004 than in 1987/1988, indicating that people 50 years of age or older became more susceptible to hip fractures. Accordingly, the accretion of the hip fracture incidence rate was greater than that which could be explained purely by changes in population size and structure.