Missed opportunities in the treatment of pediatric appendicitis
IntroductionThis study sought to evaluate the outcomes of in-hospital delay and determine associated co-morbidities in the treatment of pediatric acute appendicitis.MethodsThis was a retrospective analysis of the national inpatient sample from 2000 to 2008. Immediate treatment was defined as treatment in hospital day 0 or 1. Delay in treatment was defined as treatment in hospital day 2 and beyond.ResultsDuring the study period, 683,016 pediatric appendicitis were identified. 17,737 (2.6 %) experienced a delay in treatment. Multivariate analysis identified associated co-morbidities for delay in treatment: ALL (OR 12.84, CI 11.04–14.94), AML (OR 9.41, CI 7.58–11.68), neutropenia (OR 5.53, CI 4.60–6.65), and ovarian cyst without torsion (OR 3.17, CI 2.94–3.42). Surgical management included more than 13-fold increase in drainage procedures (5.5 vs. 0.4 %), sixfold increase in cecectomy (1.2 vs. 0.2 %), 14-fold increase in hemicolectomy (1.4 vs. 0.1 %), 11-fold increase in small bowel laceration suture repair (1.1 vs. 0.1 %), and 15-fold increase in small bowel resection (1.5 vs. 0.1 %).ConclusionsIn-hospital delay beyond 2 days is associated with significant negative outcomes with regard to complications, economic burden, and subsequent surgical management. Using the co-morbidity index, high-risk co-morbidities with associated delay in treatment were identified.

title: Gallbladder damage control: compromised procedure for compromised patients
abstract: BackgroundThe objective of this study was to analyze a population-based database for (1) recent 9-year trends in utilization of partial cholecystectomy (PC), laparoscopic PC, and trocar cholecystostomy (TC), (2) demographics, associated diagnoses, and hospital characteristics, and (3) relevant inpatient outcomes.MethodsRetrospective cohort analysis of the Nationwide Inpatient Sample (NIS) files from 2000 to 2008 was performed. For the purposes of the study, gallbladder damage control was defined as PC, laparoscopic PC, and TC.ResultsA national estimate of 10,872 gallbladder damage control cases was obtained. Procedures performed included PC (47.8 %), laparoscopic PC (27.2 %), TC (25.3 %), and intraoperative cholangiogram (IOC) (19.7 %). A total of 1,479 (13.6 %) postoperative complications were identified, including pulmonary complications (4.3 %), hemorrhage/hematoma/seroma (3.4 %), and accidental puncture or laceration during procedure (3.3 %). Common bile duct injury occurred in 3.3 % overall. Hospital types included nonteaching (82.1 %) and urban (67.8 %), with regional variations of 42.1 % from the South and 45.2 % from the West. Inpatient outcomes included mean length of stay of 11.4 (0.16 SEM) days, mean total hospital charge of $71,296.69 ($1,106.03 SEM), 7.4 % mortality, and 16.8 % discharge to skilled nursing facility. Multivariate logistic regression analysis identified independent risk variables for common bile duct injury: teaching hospitals (OR = 1.517, CI = 1.155–1.991, P = 0.003). IOC (OR = 2.030, CI = 1.590–2.591, P < 0.001) was a commonly associated procedure in the setting of common bile duct injury.ConclusionVarious circumstances may require gallbladder damage control with PC and TC. Postoperative complications and common bile duct injury remain significantly high despite limited resection, and the teaching status of the hospital is associated with CBD injury. High morbidity and mortality of gallbladder damage control may reflect both the compromised nature of the procedures and multiple comorbidities.

title: Less is more: management of pediatric splenic injury.
abstract: To analyze national trends in the nonoperative management of pediatric splenic injury.



Retrospective cohort analysis.



All children and adolescents 18 years or younger from 2 national databases who were hospitalized with pediatric splenic injury.



Data from 9 years of the National Inpatient Sample database (2000-2008) and 3 years of Kids' Inpatient Database (2000, 2003, and 2006).



We calculated and chronicled rates of splenectomy, angiography, and transfusion from 2000 to 2008.



During the study period, the rate of splenectomy decreased from 18.25% to 10.86%. Changes in nonoperative management included more than a 2-fold increase in angiography, from 2.43% to 6.94%, and a significant increase in transfusion, from 7.71% to 11.49%. Operative management was associated with increased length of stay (9.15 vs 6.52 days) and higher mean total hospital charges ($74 981.26 vs $36 156.30). Cases occurring in rural locations were more likely to undergo operative management (odds ratio, 1.24 [95% CI, 1.18-1.31]; P < .001), but less likely to undergo angiography (0.82 [0.76-0.89]; P < .001).



Children with pediatric splenic injury are undergoing fewer splenectomies but more angiography. Rural location may be an independent risk factor for operative management. Further studies are needed to assess for disparity in access to and availability of aggressive nonoperative management.

title: Is partial colectomy the operation of choice in pediatric Clostridium difficile colitis?
abstract: PurposeThis study examined the national trends in incidence and surgical management of pediatric Clostridium difficle colitis (CDC) hospitalizations.MethodsThis was a cross-sectional Nationwide Inpatient Sample (NIS) analysis of pediatric CDC from 2000 to 2008. Data analysis included patient demographics, procedures, length of stay (LOS), total hospital charges (THC), and in-hospital mortality.ResultsDuring the 9-year study period, the total number of CDC hospitalizations per year increased almost twofold, from 2,513 in 2000 to 4,817 in 2008. The rate per 100,000 discharges followed a similar trend, increasing from 38.08 in 2000 to 72.57 in 2008. Abdominal colectomy was performed in 0.35 %, with partial colectomy performed more often than total colectomy. Mortality, mean LOS, and mean THC were not statistically different between partial versus total colectomy. Children with ulcerative colitis were more likely to undergo total colectomy, (OR 35.700, CI 11.025–115.98, P < 0.001). Infants under the age of 1 year were less likely to undergo total colectomy (OR 0.568, 0.477–0.677, P < 0.001).ConclusionPediatric hospitalizations for CDC are on the rise. Partial colectomy is performed more often than total colectomy without statistical compromise of mortality, length of stay, and total hospital charges. Further studies are needed to determine the standard surgical management of pediatric CDC.

title: Elastomeric microwire-based optical gas flowmeter with stretching-enabled tunability in measurement range.
abstract: We report the utilization of transparent poly(dimethylsiloxane) (PDMS) microwires as the transducer for optical gas flowmetry. The elasticity of the PDMS microwire was exploited not only to miniaturize and simplify the flowmeter but also to widen and tune the measurement range through mechanical stretching. Using a 9 mm long microwire, we achieved 2.8~9.8 dB/SLM sensitivity. A 500 μm stretching of the microwire also shifted the measurement range from 1 to 4 SLM. The experimental results agreed well with predictions based on the fluid dynamic/optical model.

title: Principles of locomotion for simple-shaped cells
abstract: MOVING cells display a variety of shapes and modes of locomotion1, but it is not clear how motility at the molecular level relates to the locomotion of a whole cell, a problem compounded in studies of cells with complex shapes2–5. A striking feature of fish epidermal keratocyte locomotion is its apparent simplicity6. Here we present a kinematic description of locomotion which is consistent with the semicircular shape and persistent 'gliding'; motion of fish epidermal keratocytes. We propose that extension of the front and retraction of the rear of these cells occurs perpendicularly to the cell edge, and that a graded distribution of extension and retraction rates along the cell margin maintains cell shape and size during locomotion. Evidence for this description is provided by the predicted circumferential motion of lamellar features and the curvature of 'photo-marked' lines within specific molecular components of moving keratocytes. Our description relates the dynamics of molecular assemblies to the movement of a whole cell.

title: Quantitative measures of facial expression for patients with head and neck cancer
abstract: In addition to changes in facial morphology, head and neck cancer treatment can impact the facial expression. Quantification of changes in facial expression, particularly of smiling, would enable a deeper understanding of the relationship between physical changes and psychosocial adjustment in patients being treated for facial cancer. This study proposes 48 quantitative facial expression measures, which consist of the length normalized distances and slopes between 27 manually annotated fiducial points on standard 2D clinical photographs of patients with head and neck cancer. Using the proposed measures, the maximum intensity of smiling for patients with head and neck cancer prior to their treatments was compared to that of a sample from a healthy population. A total of 7 facial expression measures captured statistically significant differences between patients with head and neck cancer and healthy individuals. These measures suggest that patients with head and neck cancer are less expressive than people without head and neck cancer. This study is the first attempt to quantify the facial expression of patients with head and neck cancer and to build a foundation for studying how surgical interventions may affect their facial expressions. Moreover, this study lays the groundwork for future investigation of the relationship between facial expression and psychosocial adjustment in cancer patients.

title: Calibration of sound forces in acoustic traps
abstract: A two-dimensional or transverse acoustic trapping and its capability to noninvasively manipulate micrometersized particles with focused sound beams were experimentally demonstrated in our previous work. To apply this technique, as in optical tweezers, for studying mechanical properties of and interactions among biological particles such as cells, the trapping forces must be calibrated against known forces, i.e., viscous drag forces exerted by fluid flows. The trapping forces and the trap stiffness were measured under various conditions and the results were reported in this paper. In the current experimental arrangement, because the trapped particles were positioned against an acoustically transparent mylar membrane, the ultrasound beam intensity distribution near the membrane must be carefully considered. The total intensity field (the sum of incident and scattering intensity fields) around the droplet was thus computed by finite element analysis (FEA) with the membrane included, and it was then used in the ray acoustics model to calculate the trapping forces. The membrane effect on trapping forces was discussed by comparing effective beam widths with and without the membrane. The FEA results found that the broader beam width, caused by the scattered beams from the neighboring membrane and the droplet, resulted in the lower intensity, or smaller force, on the droplet. The experimental results showed that the measured forces were as high as 64 nN. The trap stiffness, approximated as a linear spring, was estimated by linear regressions and found to be 1.3 to 4.4 nN/μm, which was on a larger scale than that of optical trapping estimated for red blood cells, a few tenths of piconewtons/nanometer. The experimental and theoretical results were in good agreement.

title: CIP2A expression is associated with synovial hyperplasia and invasive function of fibroblast-like synoviocytes in rheumatoid arthritis
abstract: Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified oncoprotein that leads to cellular proliferation in cancer cells. We aim to investigate CIP2A expression in fibroblast-like synoviocytes (FLS) and its association with the histopathological grade of synovitis and the invasive function of FLS in rheumatoid arthritis (RA). CIP2A protein expression was measured in 8 RA FLS and 8 OA FLS using Western blot analysis. CIP2A mRNA expression from 19 RA FLS and 7 OA FLS was measured using real-time PCR. Synovitis score of RA FLS-matched synovial tissues was semiquantitatively measured by two independent pathologists. An in vitro cell invasion assay was performed using RA FLS treated with CIP2A small interfering RNA (siRNA) or with control vector. Western blot analysis showed that CIP2A is more frequently overexpressed in RA FLS compared with OA FLS. CIP2A mRNA expression was higher in RA FLS compared with those in OA FLS, but did not reach statistical significance (P = 0.076). In RA, total synovitis score was strongly correlated with FLS CIP2A mRNA expression (rs = 0.849, P = 0.043). TNF-α treatment induced a robust increase in the invasive function of control FLS (P = 0.0021), but no significant effect was observed in CIP2A siRNA-treated FLS. Our data demonstrate that CIP2A expression is closely associated with the histopathological score of synovitis and invasive function of FLS in RA. These results suggest that CIP2A may play a critical role in the destructive process in RA and warrant further investigation of CIP2A as a therapeutic target.