Arterial complications associated with cardiac catheterization in pediatric patients with a previous history of kawasaki disease

Objectives : To determine whether patients with Kawasaki Disease (KD) undergoing percutaneous catheter angiography were at increased risk of arterial complications at the point of arterial access compared to patients with structural heart abnormalities, but normal vessels. Background : Systemic arterial damage can occur as a result of KD. Methods : Medical histories of all patients with KD undergoing percutaneous catheter angiography at The Hospital for Sick Children between January 1990 and August 2008 were reviewed. Results : A total of 44 patients with KD underwent 82 catheter procedures. Of these, 3 were associated with important arterial complications (2 males; age: 4 months, 3 and 17 years). All patients who experienced complications had multiple large and/or giant coronary artery aneurysms and two were within 3 months of the acute phase of KD. All patients developed pseudoaneurysms of the femoral artery which had been utilized for catheter access. All pseudoaneurysms were treated with ultrasound‐guided thrombin injection and compression, and resolved with no long‐term complications. One patient also developed a substantial arteriovenous fistula of the femoral circulation which had to be surgically repaired with no permanent sequela. Odds for arterial complications in patients with KD were 10.4 times greater (95%CI: 3.2–33.8) than that noted for the general pediatric cardiac catheterization population (3.6% vs. 0.4%, P < 0.0001) which indicates higher risk associated with arterial access in patients with KD. Conclusions : Greater care in obtaining arterial access for angiography is warranted, especially in the first month directly following the acute phase, possibly related to systemic arterial damage associated with KD. © 2009 Wiley‐Liss, Inc.     

Development and Implementation of a Proactive Geriatrics Consultation Model in Collaboration with Hospitalists

Acutely ill hospitalized older adults often experience a decline in function that may be preventable using a proactive, interdisciplinary, patient-centered approach. Hospitalists are treating an increasing number of these patients. A collaborative geriatrics consultation model to prevent functional decline and improve care for older patients with geriatrics syndromes was developed and implemented in partnership with a large hospitalist group in a community teaching hospital. A team of a geriatrician and a geriatrics nurse practitioner led the new consultation service. The team assisted with identifying cases, provided consultation early in the hospital stay, focused its evaluation on functional and psychosocial issues, and assisted in clinical management to optimize implementation of recommendations. In the first 4 years, the consultation service conducted 1,538 consultations in patients with a mean age of 81 (range 56–103). The most frequent geriatrics diagnoses were gait instability, delirium, and depression; recommendations usually included consulting physical therapy, increasing activity, and changing medications. The number of referrals and referring physicians grew steadily each year. Twenty-eight of 34 (82%) of the referring hospitalists completed a Web-based satisfaction questionnaire. All responding hospitalists agreed that proactive geriatrics consultation helped them provide better care; 96% rated the service as excellent. Analysis of hospital administrative data revealed a lower length of stay index and lower hospital costs in patients receiving a geriatrics consultation. The Proactive Geriatrics Consultation Service represents a promising model of collaboration between hospitalists and geriatricians for improving care of hospitalized older adults.     

Biomaterials and scaffolds for ligament tissue engineering

Tissue engineering has achieved much progress in an attempt to improve and recover impaired functions of tissues and organs. Although many studies have been done, progress for tissue-engineered anterior cruciate ligaments (ACLs) has been slow due to their complex structures and mechanical properties. In this review, the ACL anatomical structure, progresses achieved, material selection, structure design, and future direction have been discussed, while the challenges and requirements from materials and scaffolds are highlighted. There is a considerably huge amount work that needs to be carried out; as such, future direction in ligament tissue engineering is proposed in hope that this review will give information on future ligament tissue engineering.     

Electrospun biocomposite nanofibrous scaffolds for neural tissue engineering

Bridging of nerve gaps after injury is a major problem in peripheral nerve regeneration. Considering the potential application of a bio-artificial nerve guide material, polycaprolactone (PCL)/chitosan nanofibrous scaffolds was designed and evaluated in vitro using rat Schwann cells (RT4-D6P2T) for nerve tissue engineering. PCL, chitosan, and PCL/chitosan nanofibers with average fiber diameters of 630, 450, and 190 nm, respectively, were fabricated using an electrospinning process. The surface chemistry of the fabricated nanofibers was determined using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Simple blending of PCL with chitosan proved an easy and efficient method for fabricating PCL/chitosan nanofibrous scaffolds, whose surface characteristics proved more hydrophilic than PCL nanofibers. Evaluation of mechanical properties showed that the Young's modulus and strain at break of the electrospun PCL/chitosan nanofibers were better than those of the chitosan nanofibers. Results of cell proliferation studies on nanofibrous scaffolds using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay showed 48% more cell proliferation on PCL/chitosan scaffolds than on PCL scaffolds after 8 days of culture. PCL/chitosan scaffolds showed better cell proliferation than PCL scaffolds and maintained their characteristic cell morphology, with spreading bipolar elongations to the nanofibrous substrates. This electrospun nanofibrous matrix thus proved of specific interest in tissue engineering for peripheral nerve regeneration.     

Electrospun biomimetic nanocomposite nanofibers of hydroxyapatite/chitosan for bone tissue engineering

The development of bioinspired or biomimetic materials is essential and has formed one of the most important paradigms in today's tissue engineering research. This paper reports a novel biomimetic nanocomposite nanofibers of hydroxyapatite/chitosan (HAp/CTS) prepared by combining an in situ co-precipitation synthesis approach with an electrospinning process. A model HAp/CTS nanocomposite with the HAp mass ratio of 30wt% was synthesized through the co-precipitation method so as to attain homogenous dispersion of the spindle-shaped HAp nanoparticles (ca. 100x30nm) within the chitosan matrix. By using a small amount (10wt%) of ultrahigh molecular weight poly(ethylene oxide) (UHMWPEO) as a fiber-forming facilitating additive, continuous HAp/CTS nanofibers with a diameters of 214+/-25nm had been produced successfully and the HAp nanoparticles with some aggregations were incorporated into the electrospun nanofibers. Further SAED and XRD analysis confirmed that the crystalline nature of HAp remains and had survived the acetic acid-dominant solvent system. Biological in vitro cell culture with human fetal osteoblast (hFOB) cells for up to 15 days demonstrated that the incorporation of HAp nanoparticles into chitosan nanofibrous scaffolds led to significant bone formation oriented outcomes compared to that of the pure electrospun CTS scaffolds. The electrospun nanocomposite nanofibers of HAp/CTS, with compositional and structural features close to the natural mineralized nanofibril counterparts, are of potential interest for bone tissue engineering applications.     

Electrospun poly(epsilon-caprolactone)/gelatin nanofibrous scaffolds for nerve tissue engineering

Nerve tissue engineering is one of the most promising methods to restore nerve systems in human health care. Scaffold design has pivotal role in nerve tissue engineering. Polymer blending is one of the most effective methods for providing new, desirable biocomposites for tissue-engineering applications. Random and aligned PCL/gelatin biocomposite scaffolds were fabricated by varying the ratios of PCL and gelatin concentrations. Chemical and mechanical properties of PCL/gelatin nanofibrous scaffolds were measured by FTIR, porometry, contact angle and tensile measurements, while the in vitro biodegradability of the different nanofibrous scaffolds were evaluated too. PCL/gelatin 70:30 nanofiber was found to exhibit the most balanced properties to meet all the required specifications for nerve tissue and was used for in vitro culture of nerve stem cells (C17.2 cells). MTS assay and SEM results showed that the biocomposite of PCL/gelatin 70:30 nanofibrous scaffolds enhanced the nerve differentiation and proliferation compared to PCL nanofibrous scaffolds and acted as a positive cue to support neurite outgrowth. It was found that the direction of nerve cell elongation and neurite outgrowth on aligned nanofibrous scaffolds is parallel to the direction of fibers. PCL/gelatin 70:30 nanofibrous scaffolds proved to be a promising biomaterial suitable for nerve regeneration.