In Vivo Efficacy Study Showing Comparative Advantage of Bacterial Infection Prevention with Zip-type Skin Closure Device vs. Subcuticular Sutures.

There remains a lack of understanding of how wound closure methods perform comparatively when exposed to patient-induced movement during healing and how they may contribute to bacterial infiltration in the wound site. The present study attempts to objectively quantify this gap. The study evaluates bacterial penetration and subsequent symptoms of infection of traditional sutures and an emerging tape-based, zip-type wound closure technology under physiologically relevant loading. In an in vivo model to simulate real-world conditions, the latter demonstrates better performance compared to commonly used sutures, holding the wound intact and minimizing bacterial penetration when subjected to simulated patient movement-induced stress.

Use of a flexible robotic transgastric natural orifice translumenal endoscopic surgery (NOTES) platform in a cadaver to test access, navigation, maneuverability, and stability.

BACKGROUND: The advancement of natural orifice translumenal endoscopic surgery (NOTES) depends on the availability of a suitable platform. A 2008 Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR) Working Group identified access, navigation, maneuverability, and stability to withstand instrument forces as the essential requirements for a successful NOTES platform [1]. No single NOTES platform can adequately achieve all four of these key capabilities. In this study, the authors tested a novel flexible endoscopic robotic platform in a cadaver to determine how it performs with respect to these specific requirements. METHODS: A highly maneuverable multichannel flexible robotic endoscopic platform developed for NOTES was used transgastrically in an adult cadaver to test the platform's ability to reach multiple intraabdominal targets. The device was under the control of the surgeon throughout the test. The surgeon was blinded to a control laparoscopic view. At each target organ, the platform was maneuvered via a joystick to provide different camera views and tool access orientation appropriate for the surgical tasks of each procedure. Standard endoscopic tools were used in the platform's two working channels to demonstrate the platform's ability to withstand the forces generated during tissue manipulation and clipping. RESULTS: The platform reached each target organ site without difficulty, relying on the endoscopic view only. The platform's unique ability to maintain stability in two- and three-dimensional space resisted forces exerted by tools in the tool channels used for tissue manipulation and clipping. Endoscopic visualization allowed the surgeon to reposition the platform easily to gain a different camera view or tool access orientation about an organ (see video in Supplementary material). CONCLUSION: The authors demonstrated that the four capabilities identified by NOSCAR can be provided by the flexible robotic endoscopic platform. These essential capabilities for the clinical implementation of NOTES were addressed specifically by this platform. The provision of these capabilities in a single device may further the advancement and adoption of NOTES.

Matrix metalloproteinases 2 and 9 are markers of inflammation but not of the degree of fibrosis in chronic hepatitis C.

BACKGROUND: The degree of liver fibrosis and inflammation is important in patients with chronic hepatitis C (CHC) in terms of therapy as well as prognosis. To obviate the need of liver biopsy, serum markers such as procollagen I, III and hyaluronic acid have been proposed but were found to be inaccurate. Controversy still exists regarding the role of matrix metalloproteinases (MMPs) as valid markers of liver fibrosis. AIM: To assess liver and serum MMP-2 and -9 as markers of fibrosis and inflammation in patients with CHC. METHODS: Thirty-five CHC patients and 8 non-hepatitis C patients with normal liver enzymes underwent liver biopsy. Activities of inflammation and fibrosis stage were determined by the Desmet score on a scale of 0-4. Serum and liver tissue MMP-2 and -9 activities were measured by zymography using substrate impregnated gels. RESULTS: Patient and control groups were similar in terms of age (50.8 +/- 15.1 vs. 50.6 +/- 15.2) and male/female ratio (18/17 vs. 4/4). In serum, MMP-9 activity was increased in patients compared to controls (308 +/- 110 vs. 163.5 +/- 35 , p < 0.05). In liver tissue, MMP-9 was also higher in patients than in controls (21 +/- 4.5 vs. 17.1 +/- 5.1, p < 0.05), whereas MMP-2 did not differ between patients and controls. Serum MMP-9 values correlated with liver histologic inflammatory grade (290.4 +/- 83 in grade 2 vs. 562.1 +/- 128 in grade 3, p < 0.05) but not with fibrosis stage. The highest rising in serum MMP-9 levels was observed between grade 2 to grade 3 and was superior to the rising in serum transaminase levels, indicating its advantage in assessing the progression of disease activity. No correlation between liver MMP activities and liver fibrosis or inflammation was observed. CONCLUSION: Serum MMPs, in particular MMP-9, can serve as markers of disease activity rather than fibrosis stage in chronic HCV patients.

Hyperhomocysteinemia in pediatric and young adult renal transplant recipients.

Hyperhomocysteinemia (HHcy) has been recently identified as an important and reversible cardiovascular risk factor in adult and pediatric renal transplant recipients. A retrospective cross-sectional analysis of 70 pediatric and young adult renal transplant recipients was performed to determine the prevalence, and important clinical and laboratory correlates of HHcy. Total homocysteine concentration, free and protein bound, was determined by fluorescence polarization immunoassay using an IMX analyzer. Hyperhomocysteinemia was defined as a serum homocysteine (Hcy) level above the 95th percentile for age. Fifty-four of 70 patients (77%) had HHcy. Comparison of patients with HHcy with patients without HHcy demonstrated no statistical difference in age (p = 0.35), gender (p = 0.76) or donor type (p = 0.20). Patients with HHcy had significantly lower calculated creatinine clearance values (Ccr) (p = 0.02), 67.3 +/- 21.2 mL/min/1.73 m(2) vs. 90.7 +/- 32.3 mL/min/1.73 m(2) for patients without HHcy. Immunosuppression did not correlate with the diagnosis of HHcy. Stepwise logistic regression identified patient age (0.18, p = 0.013) and Ccr (-0.04, p = 0.011) as significant variables. In conclusion, HHcy is more common than expected in pediatric renal transplant recipients. Patients with Ccr <80 mL/min/1.73 m(2) were statistically more likely to have a diagnosis of HHcy. We recommend that Hcy levels should be evaluated in this high risk population.

The use of art therapy to detect depression and post-traumatic stress disorder in pediatric and young adult renal transplant recipients.

Pediatric and young adult renal transplant recipients may experience feelings of depression and emotional trauma. A study was conducted to (1) determine the prevalence of depression and emotional trauma and (2) assess the utility of the Formal Elements of Art Therapy Scale (FEATS). Sixty-four renal transplant recipients, 6-21 yr of age, were evaluated using self-report measures (CDI and Davidson) and art-based assessments. Subject art was analyzed by art therapists using seven of the 14 elements of the (FEATS), to assess depression. Unlike CDI and Davidson self-report testing, all patients were able to complete the art-based directives. When self-report measures and art-based assessments were combined, 36% of the study population had testing results consistent with depression and/or post-traumatic stress. The FEATS assessments identified a subset of patients who were not identified using the self-report measures. There was a correlation between CDI and Davidson scores (p < 0.0001), Davidson scores correlated with hospital days (p = 0.05), and FEATS correlated with height Z score (p = 0.04) and donor type (p = 0.01). Patients who required psychological interventions including antidepressant therapy, psychological counseling and psychiatric hospitalization during the year after the study were identified as depressed. Sensitivity for FEATS and CDI were 22 and 50% respectively. The results suggest that while art therapy may be of utility in the identification of pediatric and young adult transplant recipients who are suffering from depression, FEATS analysis appears to lack sufficient sensitivity to warrant its use in this population. Study of other quantitative art-based assessment techniques may be warranted.

Diagnosing cystic fibrosis--asthma and failure to thrive as indications for a sweat test.

Children with asthma or failure to thrive (FTT) are frequently referred for the quantitative pilocarpine iontophoresis sweat test (QPIT) for diagnosing cystic fibrosis (CF). The aim of our study was to compare the prevalences of asthma and FTT among patients with a confirmed diagnosis of CF. Two-hundred and fifty-five children, who were referred for QPIT between 1991-1996 in order to rule out CF were studied retrospectively. All sweat samples had been obtained and analyzed according to the National Committee For Clinical Laboratory Standards. Asthma was defined as 24 episodes of wheezing, treated successfully by inhaled bronchodilators. Failure to thrive was was defined by either a weight below the 5th precentile or crossing of 2 major precentiles in 1 year. The prevalence of asthma was significantly higher than that of FTT among the cohort study (28.6% vs. 7.1% as a single indication, and 36.5% vs. 7.9% when combined with other indications). The prevalence of CF among patients with FTT was higher than among asthmatic patients (5.2% vs. 3%, p = 0.06). Not one patient diagnosed as having CF was referred to a sweat test only because of asthma. As a single presentation, the diagnostic yield of asthma seems to be poor, compared to FTT. However, further, larger-scale studies should be conducted on this issue.

Divergent patterns of extracellular matrix protein expression in neonatal versus adult liver fibrosis.

The extracellular matrix (ECM) expression is subject to distinct changes during ontogeny, and the natural course of liver fibrosis in neonates is thought to differ from that in adults. We compared the expression and distribution of main ECM components between neonatal and adult liver fibrosis. Liver biopsies from infants with neonatal cholestasis and fibrosis were compared to adult biopsies exhibiting an equivalent stage of fibrosis. All biopsies were examined by immunohistochemistry (indirect ABC method) for the ECM proteins, collagens I, III, IV, and VI, laminin, and fibronectin. Infants (aged 1-8 months) with neonatal hepatitis (n = 3), extrahepatic biliary atresia (EHBA) (n = 5), and normal histology (n = 2) were compared with 9 adults (aged 17-70 years) with chronic hepatitis (n = 3), primary biliary cirrhosis (PBC) (n = 4), and normal histology (n = 2). Collagens I, III, and IV and fibronectin were significantly increased in neonatal hepatitis with mild fibrosis (score < or = 4) compared to adults with an equivalent fibrosis stage. This increase was particularly notable in perisinusoidal spaces. Laminin expression was increased in portal and perisinusoidal spaces both in neonatal hepatitis and extrahepatic biliary atresia with mild fibrosis. In infants with moderate to severe fibrosis (score > or = 6), only collagen I was increased in comparison to adults, whereas collagen VI expression was identical in all groups, irrespective of the degree of fibrosis. Expression of matrix proteins was not different in infants and adults without fibrosis. The increased perisinusoidal deposition of certain ECM components in infants with active hepatitis and mild fibrosis may point to an underlying difference in the mechanism or stimulus of fibrogenesis in neonates as compared to adults.

Colonic hydrogen elimination and methane production in infants with and without infantile colic syndrome.

Our objective was to investigate the relationship between demographic factors, nutrition, stool gas production, and the existence of infantile colic (IC) syndrome. Hydrogen and methane production from stool specimens of infants with and without infantile colic was quantified at two separate time points, the age at presentation of colic (<12 weeks) and at >6 months of age. The relationship between demographic variables and IC was also studied. A total of 59 infants with ages ranging from 2 to 12 weeks were enrolled in the study. Of these, 30 infants developed symptoms of colic. No correlation was found between IC and birth weight, gestational age, sex, type of feeding, mean time of feeding, stool frequency, and consistency. There was also no correlation between IC and the parents' age or education or the infant's number of siblings. Analysis of the stool samples revealed that methane was produced at concentrations >2 ppm by 15.3% of the infants at age <3 months and by 46.4% of infants at age >6 months. The mean methane concentrations produced by stool increased with age (0.95 +/- 0.58 ppm at 3 months of age vs 1.29 +/- 0.65 ppm at 6 months of age. There was no difference in stool hydrogen concentration between infants with and without IC. In contrast, the mean methane level at 3 and 6 months of age was higher in infants without IC than with IC, but reached statistical significance only at 6 months of age (0.97 +/- 0.68 vs 0.93 +/- 0.46) (NS) at 3 months of age, and 1.56 +/- 0.55 vs 0.93 +/- 0.62 (P < 0.05) at 6 months of age respectively. Furthermore, infants that produced higher methane levels at 3 and 6 months of age had significantly (p < 0.05) less colic in the first months of life. In conclusions, methane production may play a role in the alleviation of IC. Future studies are needed to confirm our findings.

Unexpectedly high prevalence of posttransplant anemia in pediatric and young adult renal transplant recipients.

BACKGROUND: Although posttransplant anemia (PTA) is recognized as a common problem in adult renal transplant recipients, few pediatric studies have been published. METHODS: In this retrospective cohort study of 162 pediatric renal transplant recipients treated at Stanford University, the authors sought to determine the prevalence, severity, and the predictive factors of PTA. Anemia was defined as a hematocrit (HCT) level greater than 2 SD below published means for age or as erythropoietin dependency to maintain a normal HCT. RESULTS: Sixty-seven percent of pediatric renal transplant recipients were anemic at the time of transplantation. The prevalence of anemia increased to 84.3% in the first month posttransplant. From 6 months to 60 months posttransplant, the prevalence of anemia remained high at 64.2% to 82.2%. Only 4 patients (2.5%) were never anemic. Iron depletion was detected in 19 of 26 and 23 of 23 anemic patients 12 and 60 months posttransplant, respectively. Serum erythropoietin levels were low relative to hematocrit levels in 38 of 56 anemic patients. Logistic regression at 3 months posttransplant showed that discharge hematocrit level (P < 0.0001), calcium (P = 0.0004), and cyclosporine dose (P = 0.0002) correlated with anemia. Creatinine clearance (P = 0.002) and white blood cell count (P = 0.004) correlated with anemia at 12 months posttransplant, but only creatinine clearance (P = 0.011) correlated with anemia 60 months posttransplant. CONCLUSION: Nearly all pediatric renal transplant recipients experience PTA. However, few children less than 2 years of age were anemic during the first year posttransplant. Antirejection therapy, bone disease, iron depletion, and creatinine clearance appear to play pivotal roles in the development of PTA in children.

Late post-transplant anemia in adult renal transplant recipients. An under-recognized problem?

Post-transplant anemia (PTA), a frequent complication during the first 3-6 months after transplant, is thought to be uncommon during the late post-transplant period. A study population of adults (> 18 years) transplanted during 1995 at Stanford University (n = 88) and University of North Carolina (n = 40) was selected. Data-collection points were 0, 1, 2, 3, 4 and 5 years post transplant. Anemia was defined as a hematocrit < 33 volume percentage. Thirty percent of patients were anemic at some time during the post-transplant period. The prevalence of PTA increased over time; by 5 years post transplant, 26% of the patients were anemic. Anemia occurred in 62.5% of patients converted from azathioprine to mycophenolate mofetil. A multivariate logistic regression model demonstrated a correlation between anemia and serum total CO2 (p = 0.002), BUN (p = 0.04), and creatinine (p = 0.045) at 1 year post transplant. At 5 years post transplant, only serum total CO2 (p = 0.0004) correlated with anemia. Thus, diminished renal excretory function and metabolic acidosis appear to be the most important correlates of late PTA. These findings should be interpreted in view of the fact that the newer immunosuppressive agents may have an even more profound effect on anemia and its recovery after transplantation.