Bone marrow‐derived mesenchymal stem or stromal cells (MSC) have been shown to be recruited to various types of tumor tissues, where they interact with tumor cells to promote their proliferation, survival, invasion and metastasis, depending on the type of the tumor. We have previously shown that Ror2 receptor tyrosine kinase and its ligand, Wnt5a, are expressed in MSC, and Wnt5a‐Ror2 signaling in MSC induces expression of CXCL16, which, in turn, promotes proliferation of co–cultured MKN45 gastric cancer cells via the CXCL16‐CXCR6 axis. However, it remains unclear how CXCL16 regulates proliferation of MKN45 cells. Here, we show that knockdown of CXCL16 in MSC by siRNA suppresses not only proliferation but also migration of co–cultured MKN45 cells. We also show that MSC‐derived CXCL16 or recombinant CXCL16 upregulates expression of Ror1 through activation of STAT3 in MKN45 cells, leading to promotion of proliferation and migration of MKN45 cells in vitro. Furthermore, co–injection of MSC with MKN45 cells in nude mice promoted tumor formation in a manner dependent on expression of Ror1 in MKN45 cells, and anti–CXCL16 neutralizing antibody suppressed tumor formation of MKN45 cells co–injected with MSC. These results suggest that CXCL16 produced through Ror2‐mediated signaling in MSC within the tumor microenvironment acts on MKN45 cells in a paracrine manner to activate the CXCR6‐STAT3 pathway, which, in turn, induces expression of Ror1 in MKN45 cells, thereby promoting tumor progression.

We used US and confirmed the usefulness of a preoperative evaluation of the major diameter of the contralateral PPV at the level of the internal inguinal ring in pediatric patients with unilateral inguinal hernias.

PurposePreviously, we established a pre-operative risk scoring system to predict contralateral inguinal hernia in children with unilateral inguinal hernias. The current study aimed to verify the usefulness of our pre-operative scoring system.MethodsThis was a prospective study of patients undergoing unilateral inguinal hernia repair from 2006 to 2009 at a single institution. Gender, age at initial operation, birth weight, initial operation side, and the pre-operative risk score were recorded. We analyzed the incidence of contralateral inguinal hernia, risk factors, and the usefulness of our pre-operative risk scoring system. The follow-up period was 36 months. We used forward multiple logistic regression analysis to predict contralateral hernia.ResultsOf the 372 patients who underwent unilateral hernia repair, 357 (96.0 %) were completely followed-up for 36 months, and 23 patients (6.4 %) developed a contralateral hernia. Left-sided hernia (OR = 5.5, 95 %, CI = 1.3–24.3, p = 0.023) was associated with an increased risk of contralateral hernia. The following covariates were not associated with contralateral hernia development: gender (p = 0.702), age (p = 0.215), and birth weight (p = 0.301). The pre-operative risk score (cut-off point = 4.5) of the patients with a contralateral hernia was significantly higher, compared with the patients without a contralateral hernia using the area under the receiver operating characteristic curve (p = 0.024).ConclusionsUsing multivariate analysis, we confirmed usefulness of our pre-operative scoring system and initial side of the inguinal hernia, together, for the prediction of contralateral inguinal hernia in children.

Endocrine pancreatic insufficiency after PPPD may be explainable by obstructive pancreatitis after operation. Taking together the results of pancreatic endocrine function and morphological changes of pancreatic remnant after PPPD, tumor enucleation should be considered as surgical approach in children with pancreas head tumor whenever possible.

The management of patients with acute perforated appendicitis with abscess is controversial. The aim of the present study was to assess the outcomes of treatment in patients with this condition. We retrospectively analyzed 31 patients (16 men and 15 women with a mean age of 8.4 years) with appendicitis presenting with abscess. Patients were divided into two groups (emergency operation group and interval operation group), and clinical characteristics and outcomes of treatment were investigated. On presentation, no differences in gender, age, body weight, duration of symptoms, temperature, white blood cell count, C-reactive protein level, or maximum size of the abscess in the axial view were detected between the two groups. Fifteen patients (48.4 %) underwent emergency surgery. The remaining 16 patients (51.6 %) were initially treated conservatively with antibiotics. All 16 patients underwent planned operations after receiving conservative treatment, and two (12.5 %) of these patients underwent appendectomy before the planned operation day because of recurrent appendicitis without abscess. There were no differences in the length of hospital stay. In the emergency operation group, six (40 %) patients presented with wound infection and four (26.7 %) developed a postoperative intra-abdominal abscess. No infective complications were reported in the interval operation group. Interval appendectomy after conservative treatment of pediatric ruptured appendicitis with abscess significantly reduced postoperative infection rates.