Engineered channels enhance cellular density in perfused scaffolds.

Scaffold-based tissue engineering provides cells with an engineered matrix to enhance and direct cell attachment, proliferation and differentiation. One critical limitation to current tissue engineering approaches is the inability to create densely populated constructs thicker than a few 100 µm. We hypothesized that development of porous, channeled scaffolds would increase cell density and uniformity of their spatial distribution through scaffold channel perfusion. Patterned polyurethane sheets were fabricated using a sprayed phase separation technique and laminated together to form 1.5 mm thick channeled scaffolds. Hydraulic permeability testing confirmed the presence of functional channels throughout the multilaminate construct. A continuous flow bioreactor was used to perfuse the construct with medium during the culture period. Cross-sectional cell densities and spatial uniformities were measured in channeled and nonchanneled scaffolds under different seeding and culture conditions. Channeled scaffolds were found to have higher densities of human mesenchymal stem cells than nonchanneled samples. Perfused scaffolds had more uniform spatial distribution of cells within the scaffold compared to statically cultured scaffolds. In conclusion, we have shown the channeled scaffolds to be a promising approach toward creating thick tissue-engineered constructs.

Rectal biopsy for Hirschsprung's disease--are we performing too many?

BACKGROUND: Rectal biopsy is considered the gold standard for the diagnosis of Hirschsprung's disease. The aim of this study was to evaluate the outcome of rectal biopsies performed in our institution, and to determine whether we are performing an adequate number of biopsies in patients presenting with features suggestive of this disease. METHODS: A retrospective analysis was conducted of patients who underwent rectal biopsy to exclude Hirschsprung's disease over a seven year period between 2000 and 2006. The histological diagnosis of Hirschsprung's disease was made using haematoxylin and eosin as well as acetylcholinesterase on frozen section. Patients were grouped into three age categories: neonates (group A), infants (group B) and those over 1 year of age (group C). The results of the biopsies were compared between groups. RESULTS: A total of 668 patients underwent rectal biopsy. 18 samples were insufficient. Based on the histological studies of 650 suitable samples, 73 (11%) were positive and 577 (89%) were negative for Hirschsprung's disease. Of the 73 positive biopsies, 34 (47%) were from group A, 20 (27%) from group B and 19 (26%) from group C. The percentage of positive biopsies was much higher in group A with 29% (34 out of 118) compared to group B with 15% (20 out of 135) and group C with 5% (19 out of 395). Three complications of minor rectal bleeding occurred. CONCLUSIONS: With 3 complications and 18 insufficient samples out of 668, rectal biopsy is a safe procedure and remains the gold standard for the diagnosis of Hirschsprung's disease, despite the large number of negative biopsies. Contrary to some reports in the literature which question the need for rectal biopsy in those presenting after the neonatal period, 53% of our positive diagnoses were made in children presenting after this period, with 19 positive biopsies out of 395 (5%) performed in children above the age of 1 year.

Case report of paediatric oxalate urolithiasis and a review of enteric hyperoxaluria.

The formation of renal calculi secondary to enteric hyperoxaluria is rare in the paediatric population. We present the case of an 8-year-old boy who had short bowel syndrome resulting in enteric hyperoxaluria which led to the development of urolithiasis and bilateral ureteric strictures, both of which resolved with medical management. We also review the literature on enteric hyperoxaluria.

Guidelines on good clinical laboratory practice: bridging operations between research and clinical research laboratories.

A set of Good Clinical Laboratory Practice (GCLP) standards that embraces both the research and clinical aspects of GLP were developed utilizing a variety of collected regulatory and guidance material. We describe eleven core elements that constitute the GCLP standards with the objective of filling a gap for laboratory guidance, based on IND sponsor requirements, for conducting laboratory testing using specimens from human clinical trials. These GCLP standards provide guidance on implementing GLP requirements that are critical for laboratory operations, such as performance of protocol-mandated safety assays, peripheral blood mononuclear cell processing and immunological or endpoint assays from biological interventions on IND-registered clinical trials. The expectation is that compliance with the GCLP standards, monitored annually by external audits, will allow research and development laboratories to maintain data integrity and to provide immunogenicity, safety, and product efficacy data that is repeatable, reliable, auditable and that can be easily reconstructed in a research setting.

Clinometric properties of a clinical spasticity measurement tool.

PURPOSE: To investigate clinometric properties of an Anglo-Dutch spasticity measurement tool (ADSMT), an objective tool providing information about both neurophysiological and biomechanical aspects of spasticity about the wrist joint in the clinical setting. METHOD: ADSMT measurements were performed with 12 healthy and 11 participants with post-stroke spasticity, and consisted of assessing the maximum range of passive wrist movement (pROM) and passive wrist extension at different cycle rates. Outcome measures were wrist angle, flexor and extensor activation, and resistance to movement. Intra-class Correlation Coefficients (ICCs) were calculated for inter-rater and test-retest reliability. Validity was investigated by calculating Spearman's rho between ADSMT outcome measures and the Modified Ashworth Scale (n=12), the Action Research Arm Test (n=6), and a validated wrist rig (n=6). RESULTS: Impaired participants had higher flexor activity and higher resistance to movement during passive wrist extension compared to unimpaired participants. For all outcome measures inter-rater and test-retest reliability were satisfactory to good and concurrent validity was sufficient. CONCLUSIONS: Outcome measures related to wrist flexor activity and resistance to movement during extension are promising for spasticity assessment using the ADSMT. Further knowledge on reference values and practicality is necessary for this tool to become incorporated in the clinical setting.

Reducing transfer times for coronary angiography in patients with acute coronary syndromes: one solution to a national problem.

BACKGROUND: Patients with acute coronary syndrome (ACS) are at high risk of further cardiac events and benefit from early intervention, as reflected by international guidelines recommending early transfer to interventional centres. The current average waiting time of up to 21 days contravenes evidence based early intervention, creates geographical inequity of access, wastes bed days, and is unsatisfactory for patients. METHODS: A regional transfer unit (RTU) was created to expatriate access of ACS patients referred from other centres to the revascularisation service. By redesigning the care pathway patients arriving on the RTU undergo angiography within 24 hours, and then leave the RTU the following day, allowing other ACS patients to be treated. RESULTS: During the first six months of the RTU, the mean waiting time from referral to procedure decreased from 20 (SD 15) days (range 0-51) to 8 (SD 3) days (range 0-21) for 365 patients transferred from a district general hospital. Ninety seven per cent of patients underwent angiography within 24 hours, 61% having undergone percutaneous coronary intervention at the same sitting, and 78% were discharged home within 24 hours. CONCLUSIONS: Delivering standards laid out in the National Service Framework, reducing inequalities of care across the region, and facilitating evidence based strategies of care represents a challenging and complex issue. For high risk patients suffering ACS who need early invasive investigation, a coordinated network wide approach together with the creation of an RTU resulted in a 62% reduction in waiting times for no extra resources. Further improvements can be expected through increased capacity of this verified strategy.

Biomechanical approaches applied to the lower and upper limb for the measurement of spasticity: a systematic review of the literature.

PURPOSE: To review and characterise biomechanical approaches for the measurement of spasticity as one component of the upper motor neurone syndrome. METHOD: Systematic literature searches based on defined constructs and a four-step review process of approaches used or described to measure spasticity, its association with function or associated phenomena. Most approaches were limited to individual joints and therefore, to reflect this trend, references were grouped according to which body joint(s) were investigated or whether it addressed a functional activity. For each joint, references were further sub-divided into the types of measurement method described. RESULTS: A database of 335 references was established for the review process. The knee, ankle and elbow joints were the most popular, perhaps reflecting the assumption that they are mono-planar in movement and therefore simpler to assess. Seven measurement methods were identified: five involving passive movement (manual, controlled displacement, controlled torque, gravitational and tendon tap) and two involving active movement (voluntary and functional). Generally, the equipment described was in an experimental stage and there was a lack of information on system properties, such as accuracy or reliability. Patient testing was either by cohort or case studies. The review also conveyed the myriad of interpretations of the concept of spasticity. CONCLUSIONS: Though biomechanical approaches provide quantitative data, the review highlighted several limitations that have prevented them being established as an appropriate method for clinical application to measure spasticity.

Theoretical and methodological considerations in the measurement of spasticity.

PURPOSE: To discuss the measurement of spasticity in the clinical and research environments, make recommendations based on the SPASM reviews of biomechanical, neurophysiological and clinical methods of measuring spasticity and indicate future developments of measurement tools. METHOD: Using the results of the systematic reviews of the biomechanical, neurophysiological and clinical approaches, methods were evaluated across three dimensions: (1) validity, reliability and sensitivity to change; (2) practical quality such as ease of use and (3) qualities specific to the measurement of spasticity, for example ability to be applied to different muscle groups. Methods were considered in terms of applicability to research and clinical applications. RESULTS: A hierarchy of measurement approaches was identified from highly controlled and more objective (but unrelated to function) to ecologically valid, but less objective and subject to contamination from other variables. The lack of a precise definition of spasticity may account for the problem of developing a valid, reliable and sensitive method of measurement. The reviews have identified that some tests measure spasticity per se, some phenomena associated with spasticity or consequential to it and others the effect of spasticity on activity and participation and independence. CONCLUSIONS: Methods appropriate for use in research, particularly into the mechanism of spasticity did not satisfy the needs of the clinician and the need for an objective but clinically applicable tool was identified. A clinical assessment may need to generate more than one 'value' and should include evaluation of other components of the upper motor neurone syndrome. There is therefore a need for standardized protocols for 'best practice' in application of spasticity measurement tools and scales.

Diversion colitis in children with colovaginoplasty.

OBJECTIVE: To highlight the occurrence of diversion colitis and its effects in colovaginoplasty. Patients and methods The records of 18 children who had undergone colovaginoplasty were reviewed retrospectively. Nine patients had androgen-insensitivity syndrome and three each had congenital adrenal hyperplasia, vaginal agenesis and Mayer-Rokitansky syndrome. Through an abdominoperineal approach a segment of sigmoid colon was isolated on its vascular pedicle and brought to the perineum in the plane between the urethra and rectum, as a blind pouch or as an interposition between the proximal vagina and the perineum. The mean (range) follow-up was 5 (1.5-8) years. RESULTS: There were no major complications during the early follow-up. Three patients developed severe vaginal discharge with bleeding 2-7 years after colovaginoplasty; examination showed erythema, oedema, ulceration and bleeding. Histology confirmed the classic features of diversion colitis in all three patients. One child responded to vaginal irrigation with a solution of short-chain fatty acids, and the other two were treated with steroid enemas and mesalazine after a poor response to short-chain fatty acids. One of these patients has required surgical reduction of an excessively long neovagina. Conclusion Symptomatic diversion colitis can occur after colovaginoplasty. The severity of the symptoms raises concerns about the use of colovaginoplasty in children and alternative techniques of vaginal replacement should be considered in the first instance.

Immunologic reconstitution following bone marrow transplantation for X-linked hyper IgM syndrome.

X-linked hyper IgM syndrome (XHIM), caused by mutations of the CD40 ligand (CD40L) gene, is characterized by recurrent bacterial and opportunistic infections, an increased incidence of autoimmunity and malignancies, and immunodeficiency due to abnormal T/B cell interaction. Because of poor long-term prognosis, bone marrow transplantation (BMT) has been proposed as an alternative treatment. An 8-month-old boy with XHIM and a splice site mutation of CD40L underwent BMT using a fully matched sibling donor. Markers of engraftment and immunologic reconstitution were measured serially. After BMT, activated T cells expressed functional CD40L, and genomic DNA obtained from circulating white cells contained predominantly wild-type CD40L sequences. Serum immunoglobulin levels including IgE and antibody responses to recall antigens normalized, and immunization with the T-cell-dependent neoantigen, bacteriophage φX174, demonstrated amplification of the response and isotope switching. BMT provides a permanent cure for XHIM if a fully matched sibling donor is available and the procedure is performed before complications have occurred.

Involvement of a herbimycin A-sensitive protein tyrosine kinase in extracellular action of HIV-1 Nef.

Extracellular Nef which has been implicated in disease progression and development of AIDS induces IL-10, a potent immunosuppressive cytokine, in vitro. The present study was designed to examine whether the action of extracellular Nef is a protein tyrosine kinase (PTK)-dependent event. Anti-phosphotyrosine immunoblotting reveals that recombinant HIV-1 Nef induces rapid tyrosyl phosphorylation of several cellular proteins in human peripheral blood mononuclear cells. Pre-treatment of cells with herbimycin A, but not with genistein, significantly abolishes the Nef-induced tyrosine phosphorylation of cellular proteins. Furthermore, ELISA and RNase protection assays show that herbimycin A significantly blocks Nef-induced production of IL-10 at both the protein and the mRNA level. Genistein and aminogenistein have a much less blocking effect on the ability of Nef to induce IL-10. These results provide evidence for the involvement of a herbimycin A-sensitive PTK in the signal transduction pathway for exogenous HIV-1 Nef.

Megacystis-microcolon-intestinal hypoperistalsis syndrome: the difficulties with antenatal diagnosis. Case report and review of the literature.

Megacystis on antenatal scan in female fetuses is rare and has serious diagnostic implications. We report two cases of megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) in female infants in whom antenatal scan abnormalities were identified, but the diagnosis not made until after delivery. MMIHS is a rare autosomal recessive condition which is usually lethal in the first year of life. Prenatal diagnosis is hampered by the lack of specific diagnostic findings on ultrasound and the absence of an identified genetic locus. The prenatal findings in MMIHS are reviewed and contrasted with those of other causes of lower abdominal masses on antenatal ultrasound.

Unusual vascular dysplasia presenting as an intra-abdominal catastrophe.

A case of severe, generalised vascular dysplasia presenting as an intra-abdominal catastrophe is reported. Associated clinical features included cutis marmorata telangiectatica congenita, congenital glaucoma, hypertension, and focal fits. The case has been reported in view of its rarity and nature of presentation.

Skeletal myogenesis on elastomeric substrates: implications for tissue engineering.

Studies geared towards understanding the interaction between skeletal muscle and biomaterials may provide useful information for the development of various emerging technologies, ranging from novel delivery vehicles for genetically modified cells to fully functional skeletal muscle tissue. To determine the utility of elastomeric materials as substrates for such applications, we asked whether skeletal myogenesis would be supported on a commercially available polyurethane, Tecoflex SG-80A. G8 skeletal myoblasts were cultured on Tecoflex two-dimensional solid thin films fabricated by a spin-casting method. Myoblasts attached, proliferated, displayed migratory activity and differentiated into multinucleated myotubes which expressed myosin heavy chain on solid thin films indicating that Tecoflex SG-80A was permissive for skeletal myogenesis. Porous three-dimensional (3-D) cell scaffolds were fabricated in a variety of shapes, thicknesses, and porosities by an immersion precipitation method, and where subsequently characterized with microscopic and mechanical methods. Mechanical analysis revealed that the constructs were elastomeric, recovering their original length following 100% elongation. The 3-D substrates were seeded with muscle precursors to determine if muscle differentiation could be obtained within the porous network of the fabricated constructs. Following several weeks in culture, histological studies revealed the presence of multinucleated myotubes within the elastomeric material. In addition, immunohistochemical analysis indicated that the myotubes expressed the myosin heavy chain protein suggesting that the myotubes had reached a state of terminal differentiation. Together the results of the study suggest that it is indeed feasible to engineer bioartificial systems consisting of skeletal muscle cultivated on a 3-D elastomeric substrate.

Neurological rehabilitation in Indonesia and the UK: differences and similarities.

Both countries face considerable challenges to their rehabilitation services. Although contextually different, the problems and challenges are common to both. Two contrasting views of disability have been presented. In the UK disability may be viewed as a disaster, while in Asia illness and disability may be viewed as inevitable. Personal independence is not a universal goal of rehabilitation, because in some cultures dependence on others is an expected consequence of disability. Disability in Indonesia translates into a large burden of care for the family, whereas English families may expect greater help from the government in caring for their relative. Western rehabilitation is increasingly patient directed, whereas the Indonesian model is more likely to be determined solely by professionals. The problems observed by the team in Indonesia were remarkably similar to those experienced in the UK. A patient centered goal setting approach can be considered vital to neurological rehabilitation, although the focus of the goals set is likely to be very different in these two cultures. The fundamental importance of a multidisciplinary team is recognized in both cultures, although team working may not be easy in either situation. Managerial commitment is essential for the survival of a team, yet both structures sometimes fail to provide the necessary support. Hierarchical leadership can inhibit team development both in the UK and in Indonesia, as can frequent rotation of staff. Prescription of therapy by doctors inhibits the development of therapists in both cultures, and therefore the overall effectiveness of the team. In both the UK and Indonesia, the value of rehabilitation as a specialty is not widely recognized. The absence of life and death situations means that services are often out of the public eye, and poorly understood. However, the prevalence of disability will increase the need for rehabilitation services worldwide. Many challenges remain in both the UK and Indonesia to the development of more effective rehabilitation services. Issues like the lack of recognition of rehabilitation as a specialty, the importance of team work, the paucity of managerial support, and increasing demand for rehabilitation services will need to be recognized and addressed. Despite the different approaches to disability in the two cultures, the problems faced are similar. These problems will need to be solved if there is to be significant progress in this multidisciplinary field.

Bladder hemangioma as a cause of massive hematuria in a child. A case report and literature review.

A 12-year-old girl with bladder hemangioma presenting with massive hematuria is described. The patient was previously operated for removal of cystic hygroma from the chest wall. The association of those two pathological entities suggests possible common etiology and pathogenesis and the various therapeutic options are reviewed.