Defining the volume of consultations for musculoskeletal infection encountered by pediatric orthopaedic services in the United States.

OBJECTIVE: Adequate resources are required to rapidly diagnose and treat pediatric musculoskeletal infection (MSKI). The workload MSKI consults contribute to pediatric orthopaedic services is unknown as prior epidemiologic studies are variable and negative work-ups are not included in national discharge databases. The hypothesis was tested that MSKI consults constitute a substantial volume of total consultations for pediatric orthopaedic services across the United States. STUDY DESIGN: Eighteen institutions from the Children's ORthopaedic Trauma and Infection Consortium for Evidence-based Study (CORTICES) group retrospectively reviewed a minimum of 1 year of hospital data, reporting the total number of surgeons, total consultations, and MSKI-related consultations. Consultations were classified by the location of consultation (emergency department or inpatient). Culture positivity rate and pathogens were also reported. RESULTS: 87,449 total orthopaedic consultations and 7,814 MSKI-related consultations performed by 229 pediatric orthopaedic surgeons were reviewed. There was an average of 13 orthopaedic surgeons per site each performing an average of 154 consultations per year. On average, 9% of consultations were MSKI related and 37% of these consults yielded positive cultures. Finally, a weak inverse monotonic relationship was noted between percent culture positivity and percent of total orthopedic consults for MSKI. CONCLUSION: At large, academic pediatric tertiary care centers, pediatric orthopaedic services consult on an average of ~3,000 'rule-out' MSKI cases annually. These patients account for nearly 1 in 10 orthopaedic consultations, of which 1 in 3 are culture positive. Considering that 2 in 3 consultations were culture negative, estimating resources required for pediatric orthopaedic consult services to work up and treat children based on culture positive administrative discharge data underestimates clinical need. Finally, ascertainment bias must be considered when comparing differences in culture rates from different institution's pediatric orthopaedics services, given the variability in when orthopaedic physicians become involved in a MSKI workup.

X-Linked inhibitor of apoptosis protein expression level in colorectal cancer is regulated by hepatocyte growth factor/C-met pathway via Akt signaling.

PURPOSE: The inhibitor of the apoptosis protein (IAP) family members, such as the X-linked IAP (XIAP), survivin, and livin, are essential for cell survival and antiapoptosis in colorectal cancer cells. We hypothesized that the hepatocyte growth factor (HGF) activation in colorectal cancer via c-Met receptor regulates IAP proteins through Akt signaling. EXPERIMENTAL DESIGN: The level of IAPs and C-Met mRNA expression was assessed using a quantitative real-time reverse transcriptase-PCR (RT-PCR) assay on colorectal normal mucosa (n = 13), adenomas (n = 6), and colorectal cancer tumors (n = 50). The role of HGF/C-Met pathway through Akt and XIAP was investigated by small interfering RNA (siRNA) and quantitative RT-PCR analysis of colorectal cancer lines. RESULTS: Of the IAPs, only XIAP showed significant correlation to tumor development and progression. XIAP mRNA level in primary colorectal cancer was significantly higher than that in colorectal normal mucosa (P = 0.01); liver metastases was significantly higher than primary colorectal cancer tumors (P = 0.04); and primary colorectal cancer N1/N2 cases were significantly higher than N0 cases (P = 0.008). HGF stimulation of colorectal cancer lines enhanced XIAP mRNA expression but not other IAPs. Activation of XIAP expression by HGF was inhibited by siRNA targeting Akt1 and Akt2. CONCLUSIONS: Activation of C-MET enhances XIAP through the Akt pathway. XIAP up-regulation was shown to be correlated to colorectal cancer tumor progression. The Akt-XIAP pathway may be a potential molecular target for regulating colorectal cancer progression.