Interferon gamma inhibits inter-enterocyte communication by reducing connexin 43 phosphorylation

Introduction. Restitution of the intestinal barrier requires inter-enterocyte communication via the phosphorylated gap junction protein connexin 43. Experimental necrotizing enterocolitis (NEC) is characterized by elevated interferon gamma (IFN) and impaired restitution. We therefore hypothesized that IFN impairs gap junction (GJ) function and restitution by inhibiting phosphorylation of connexin43. We further sought to determine whether connexin 43 phosphorylation was altered in human NEC. Methods. Connexin 43 expression and phosphorylation was assessed in IEC-6 cells ± IFN (1000 u/ml) by SDS--PAGE and confocal microscopy. GJ function was detected by microinjecting IEC-6 cells ± IFN with the GJ tracer lucifer yellow (LY) and impermeant rhodamine dextran. GJ function was inhibited with oleamide (10 μM). In vitro restitution was assessed using time lapsed video microscopy of IEC-6 cells ± IFN migrating across a scraped wound. Small bowel mucosal scrapings were acquired from infants undergoing bowel resection for NEC and compared to specimens taken from infants without NEC. Data are mean ± SEM. Results. IFN significantly reduced phosphorylation of connexin 43 (band density relative to actin, Ctrl: 0.86 ± 0.3 versus IFNγ 0.37 ± 0.1, P < 0.05) and decreased membrane localization of the phosphorylated gap junctions. This correlated with decreased gap junction function as detected by loss of LY transfer (levels of intercellular transfer: Ctrl: 3.2 ± 0.2, IFN 2.4 ± 0.3, oleamide 0, P < 0.05). Oleamide and IFN significantly reduced enterocyte restitution (ctrl: 5 μm/h, oleam: 1.5 μm/h, IFN: 1.6 μm/h, P < 0.05), correlating with a lack of intercellular communication. Strikingly, phosphorylation of connexin 43 in the mucosa of infants with NEC was significantly reduced as compared to control bowel, which correlated with the extent of mucosal disease. Conclusion. IFN inhibits phosphorylation of connexin 43, leading to impaired inter-enterocyte communication and reduced restitution. The finding of decreased phosphoconnexin 43 in human NEC suggests that impaired inter-enterocyte communication may underlie the barrier dysfunction in this disease.     

Association Between Ankle Fractures and Obesity

Obesity is an epidemic in the United States and is associated with an increased risk of musculoskeletal problems. Rotational injuries of the ankle with a Weber C fibula fracture have a greater risk of syndesmosis disruption and instability. The goal of the present study was to explore the association between obesity and ankle fractures. Using a retrospective review, the radiographs of 280 patients with an ankle fracture were reviewed and classified using the Weber classification, which was then associated with the body mass index, gender, age, diabetes, tobacco use, and osteoporosis. Patients with a body mass index of 30 kg/m² or greater (odds ratio 1.78), men (odds ratio 1.74), and age 25 years or younger (odds ratio 3.97) had greater odds of having a Weber C ankle fracture (compared with Weber A and B) and Weber C and B (compared with Weber A). Diabetes mellitus, osteoporosis/osteopenia, and current tobacco use were not significantly associated with the severity of the ankle fracture. The results from the present study suggest that obesity presents a greater risk of sustaining a more proximal distal fibula fracture.     

FDG-PET/CT-guided intensity modulated head and neck radiotherapy: a pilot investigation

BACKGROUND: 2-deoxy-2[(18)F]fluoro-D-glucose-positron emission tomography (FDG-PET) imaging can be registered with CT images and can potentially improve neck staging sensitivity and specificity in patients with head and neck squamous cell cancer. The intent of this study was to examine the use of registered FDG-PET/CT imaging to guide head and neck intensity modulated radiotherapy (IMRT) planning. METHODS: Twenty patients with squamous cell carcinoma of the oral cavity, oropharynx, larynx, or hypopharynx underwent FDG-PET and contrast-enhanced CT imaging of the head and neck before neck dissection surgery. Combined FDG-PET/CT images were created by use of a nonrigid image registration algorithm. All IMRT plans were theoretical and were not used for treatment. We prescribed 66 Gy in 30 fractions to FDG-avid CT abnormalities and nodal zones directly involved with disease, without prophylactic coverage of uninvolved neck levels. Matched CT-guided IMRT plans designed according to the specifications of Radiation Therapy Oncology Group (RTOG) H-0022 were available for comparison. We investigated the feasibility of FDG-PET/CT-directed IMRT dose escalation in five patients with FDG-avid disease located away from critical normal structures. After 66 Gy, FDG-avid disease with 0.5-cm margins was boosted in 220 cGy increments until dose-limiting criteria were reached. RESULTS: Elimination of prophylactic coverage to FDG-PET/CT-negative neck levels markedly reduced mean dose (Dmean) to the contralateral parotid gland (p < .001) and Dmean to the laryngeal cartilage (p = .001). No FDG-PET/CT-directed plan missed pathologically verified nodal disease. During the dose escalation exercise, we successfully increased the dose to 95% of the planning target volume (PTV95%) to a mean of 7490 cGy (range, 7153-8098 cGy). CONCLUSIONS: We demonstrate early proof of the principle that FDG-PET/CT-guided IMRT planning can selectively target and intensify treatment of head and neck disease while reducing critical normal tissue doses. Routine clinical use of such planning should not be engaged until the accuracy of FDG-PET/CT is fully validated. Future directions, including refinement of treatment to gross disease and radiologically uninvolved neck nodal levels, are discussed.     

Laparoscopic resection of type I choledochal cyst

Type I choledochal cyst is a rare saccular or fusiform congenital dilatation of the extrahepatic biliary tract. It is usually treated by laparotomy at which the cyst is completely excised and a Roux-en-Y hepaticojejunostomy is performed to establish biliary enteric drainage. We report the laparoscopic excision and hepaticoduodenostomy of type I choledochal cyst in two girls aged 1 and 3 years. The entire procedure was performed laparoscopically using needlescopic instruments. A 7-mm telescope port was inserted at the umbilicus, a 3-mm port in the right upper quadrant, and a 6-mm port in left upper quadrant. An additional 3-mm fan-shaped liver retractor was passed through the abdominal wall without a trocar. The gallbladder and choledochal cyst was dissected and removed en bloc. The lower end of the common bile duct was closed with 5-0 polydioxanone. The duodenum was anastomosed to the common hepatic duct below the confluence of the right and left hepatic ducts. There were no intraoperative complications, and the children were asymptomatic with no episodes of cholangitis at 6 months follow-up. Pediatric surgeons trained in advanced laparoscopic techniques including intracorporeal suturing can perform laparoscopic repair of choledochal cyst safely.     

External Iliac Endofibrosis in Endurance Athletes: A Novel Case in an Endurance Runner and a Review of the Literature

BACKGROUND: There is increasing recognition that high-performance athletes can develop symptomatic arterial flow restriction in one or both (15%) legs due to kinking and/or endofibrosis of their iliac arteries. METHODS: Case report and review based on a Medline search of the literature. RESULTS: A 51-year-old female, 24-hour endurance runner presented with a six-month history of rapidly progressing intermittent claudication affecting her right thigh and calf in the absence of classical risk factors for atherosclerosis. On the basis of invasive and non-invasive investigations, a provisional diagnosis of endofibrosis was made and she was treated successfully with angioplasty. CONCLUSIONS: The epidemiology, optimal investigation and treatment of iliac endofibrosis in endurance athletes is poorly described. Each individual unit's experience is likely to be very small. A European register of such cases would increase our understanding of the condition and improve patient outcomes.     

Monocyte Infiltration and Kidney Allograft Dysfunction During Acute Rejection

Multiple cell types infiltrate acutely rejecting renal allografts. Typically, monocytes and T cells predominate. Although T cells are known to be required for acute rejection, the degree to which monocytes influence this process remains incompletely defined. Specifically, it has not been established to what degree monocytes impact the clinical phenotype of rejection or how their influence compares to that of T cells. We therefore investigated the relative impact of T cells and monocytes by correlating their presence as measured by immunohistochemical staining with the magnitude of the acute change in renal function at the time of biopsy in 78 consecutive patients with histological acute rejection. We found that functional impairment was strongly associated with the degree of overall cellular infiltration as scored using Banff criteria. However, when cell types were considered, monocyte infiltration was quantitatively associated with renal dysfunction while T-cell infiltration was not. Similarly, renal tubular stress, as indicated by HLA-DR expression, increased with monocyte but not T-cell infiltration. These data suggest that acute allograft dysfunction is most closely related to monocyte infiltration and that isolated T-cell infiltration has less acute functional impact. This relationship may be useful in assigning acute clinical relevance to biopsy findings.     

Long-term follow-up of patients with necrotizing enterocolitis

Background/Purpose: Despite the rise in the incidence of necrotizing enterocolitis (NEC), there is a paucity of data regarding long-term patient outcome. The authors examined functional outcome of infants with NEC (n = 103) treated at our institution between 1991 and 1995. Methods: The authors reviewed the medical records of infants who were treated both operatively and nonoperatively, n = 103. Variables examined included gestational age, birth weight, Bell stage (I through III), operations performed, and mortality rate. Telephone interviews assessed school enrollment, developmental delay, bowel function, and nutritional status. Results: Children treated operatively had a lower gestational age than those in the nonoperative group. Likewise, birth weight in the operative group was significantly lower. Sixty-three percent of patients had stage III, and the remainder had stage II disease. The telephone response rate was 61%. Mean age at follow-up was 7.5 [plusmn] 2.5 years. All children ate by mouth. Nearly all children were toilet trained. All children were less than the 50th percentile for height and weight, and the majority (83%) were enrolled in school full time. Conclusion: Infants with stage II and III NEC who are treated operatively or nonoperatively have a favorable long-term outcome. J Pediatr Surg 37:1048-1050.     

Risk factors for splenectomy in children with blunt splenic trauma

Background/Purpose: Nonoperative management and splenic preservation have become standards of care for management of pediatric blunt splenic trauma. However, review of the Pennsylvania Trauma Outcome Study (PTOS) registry found that 15% of children with blunt splenic injury still underwent splenectomy. The authors sought to determine the factors that predisposed to splenectomy in this population. Methods: Between 1993 and 1997, 754 children, ages 0 to 16 years, who sustained blunt splenic trauma were entered in the PTOS database. These patients were stratified into groups according to the mode of management: nonoperative, splenorrhaphy, or splenectomy. Logistic regression was performed to determine factors associated with splenectomy. Results: Overall, 15.1% of patients underwent splenectomy, 7.4% underwent splenorrhaphy, and 77.5% were treated nonoperatively. Spleen injury grade, nonspleen abdominal injuries, Glasgow Coma Scale 3 to 8, and age 15 to 16 years were significant determinants of splenectomy by multivariate analysis. Children treated at pediatric trauma centers (PTC) underwent significantly fewer splenectomies. Conclusions: Injury grade, but not hemodynamic instability, was a significant independent determinant of splenectomy in children with blunt splenic trauma. Children treated at PTC are less likely to undergo splenectomy. Ongoing analysis of the management of blunt pediatric splenic injury and reduction of unnecessary splenectomies are needed to optimize care for injured children.     

Comparison of ThinPrep versus conventional smear cytopreparatory techniques for fine-needle aspiration specimens of head and neck masses.

OBJECTIVES: Diagnostic accuracy of the ThinPrep process (Cytyc, Boxborough, MA) was compared with that of conventional (smear) cytopreparation for fine-needle aspiration (FNA) of head and neck masses. METHODS: In a prospective, randomized, single-blinded study, 209 patients served as their own controls and underwent 236 FNAs using ThinPrep and conventional (smear) cytopreparatory techniques. RESULTS: ThinPrep produced less air-drying artifact and less mechanical distortion than the conventional method. The conventional technique was diagnostic in 63% of samples; the ThinPrep technique was diagnostic in 55% of samples. When all results were combined, pathologists subjectively preferred the conventional technique but accepted use of ThinPrep as the only cytopreparatory technique for most head and neck masses. CONCLUSIONS: For adequately experienced cytopathologists, ThinPrep is acceptable for FNA of salivary masses, neck cysts, metastatic lymph nodes, and thyroid lesions. Conventional smear technique should be used for FNA of nonmetastatic lymphoid lesions. Use of ThinPrep can complement use of the conventional (smear) cytopreparatory technique when aspirate is nondiagnostic or bloody, when the patient has a blood-borne infectious disease, when the clinician is inexperienced, or when aspirate has entered the syringe.