New resorbable plate and screw system in pediatric craniofacial surgery

Early forms of resorbable fixation induced foreign body reactions requiring surgical removal of the fixation material. Most current plating systems attempt to circumvent this phenomenon by altering the composition of the α esters involved. ResorbX (KLS Martin, Jacksonville, FL), a plating system derived from 50:50 poly(D,L)lactide, boasts short resorption times, minimal foreign body reaction, and adequate strength for bony fixation. We present our experience with 134 patients undergoing correction of primary craniosynostosis, using ResorbX. One hundred thirty-four consecutive craniosynostosis patients underwent correction with calvarial remodeling by the senior author between April 2002 and March 2008. Five patients had 2-stage repairs. Postoperative analysis included plate visibility or palpability, head contour, and the incidence of complications. The mean age at repair was 17.0 months, with the median age being 9.0 months (range, 2.5-137 months). Postoperative follow-up visits were recorded at 3-month intervals from 0 to 24 months. Synostosis diagnoses were as follows: 43 metopic, 37 sagittal, 27 coronal, 5 lambdoid, and 27 multisutural synostosis. There were 3 complications requiring operative intervention. Three plates became exposed through the coronal excision, requiring removal, for an overall complication rate of 2%. Forty-four patients (31.7%) had a visible mass at the site of fixation at some point postoperatively; all of these resolved through observation only. Overall postoperative head aesthetics were deemed satisfactory to excellent, and no instances of contour regression occurred. This study documents the safety and efficacy of ResorbX in pediatric cranial vault remodeling. The system is easy to use, and with the advent of an ultrasonic pin, more abbreviated operating and anesthesia times are achievable.     

Prednisone when used as treatment for rejection correlates with poor outcome

Since January 1974, 195 of 202 (95%) renal transplants have been performed on blacks at the Howard University Hospital Transplant Center. Hypertension is the most common cause of end-stage renal disease (ESRD) at this center (57%). The immunosuppressive regimens utilized were divided into four eras. The first era (1974-1980) consisted of the prophylactic administration of prednisone, Imuran (AZA), and Minnesota antilymphocyte globulin (MAG) with high prednisone dosage used to treat rejection. One-year, two-year, and five-year patient survival rates were 59% 54%, and 41%, respectively. Graft survival rates for the same period were 53%, 47%, and 36%. In the second era (1980-1983), the same immunoprophylaxis was used but only MAG was used to reverse rejection. One-year and two-year patient survival rates were 90% and 84%. Graft survival rates for the same period were 72% and 64%. When era 1 is compared with era 2, statistically significant improvement in patient survival is evident (P less than 0.005). Graft survival rates are statistically significant for one-year graft survival (P less than 0.05). In the third era (1983-1986), cyclosporine was the principal immunosuppressive agent used along with prednisone. Rejection in this era was treated by adjusting the cyclosporine dose to keep the level between 100 ng to 150 ng per mL and in addition to high prednisone. One-year patient survival and graft survival rates were 83% and 55%, respectively. The fourth era began April 1986 and was initiated because of previous bad experiences with high doses of prednisone to treat rejection in era 1.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of cyclosporin A on immunoglobulin production by EB virus stimulated lymphocytes

Cyclosporin A (Cy A) enhances immunoglobulin (Ig) production by EB virus stimulated peripheral blood lymphocytes from normal subjects with prior immunity to EB virus. In 11 normal adults, this enhancement of Ig production correlated with T cell-mediated cytotoxic regression. Cultures from normal healthy adults without prior immunity showed a diminution of Ig production when Cy A was added. However, Cy A had no effect on Ig production by cord blood lymphocytes in the first week of culture but there was definite enhancement after 3 weeks. Cy A thus inhibits both the early phase of T cell help (which is lymphokine- or interferon-mediated) and the later phase of cytotoxicity manifested as regression. Furthermore, Cy A tended to inhibit IgG and IgA production in T depleted cultures, and had little effect on IgM or IgD, suggesting a differential effect on B cell subsets. These reactions to EB virus in vitro were investigated in two diseases in which EB virus immunity may be relevant. Six of 14 adult patients with primary hypogammaglobulinaemia showed no T cell-mediated regression nor Cy A enhancement, probably because of an underlying defect in both T and B cells. Regression was variable in 12 cases of rheumatoid arthritis, but Cy A initially diminished and later enhanced immunoglobulin production in all cases, suggesting a defect in the normal early response to EB virus in vitro.     

Radiographic contrast agents and platelet function: a quenched-flow study

Radiographic contrast media (RCM) may alter platelet behavior at concentrations achieved during cardiac angiography. We used quenched-flow aggregometry coupled to single-particle counting to study the influence of RCM on the kinetics of platelet aggregation (less than 5.0 sec) induced by adenosine diphosphate (ADP, 2.86 microM). At a concentration in platelet-rich plasma (PRP) of 5 per cent RCM by volume, platelet aggregation was inhibited by diatrizoate, iopamidol and ioxaglate either directly or following incubation of each contrast agent with PRP for 20 minutes. Diatrizoate inhibited more than did iopamidol or ioxaglate (56 +/- 6, versus 39 +/- 3 and 40 +/- 9 per cent respectively; P less than 0.003, p less than 0.009, n = 20 normal subjects). A small reduction (about 16 per cent) in aggregation velocity occurred within 5 seconds of exposure of PRP to all 3 RCM and the onset time (t) or lag period before aggregation begins was significantly prolonged by diatrizoate (p less than 0.03). The RCM vehicles alone (iodinated moiety removed, osmolality readjusted) had no effect on the ADP-induced aggregation. Platelet counts fell significantly after incubation with diatrizoate (12%; p = 0.04). Our data therefore show that early platelet aggregation was inhibited by 3 commonly-used ionic and nonionic contrast agents. Inhibition was apparently caused by the iodinated contrast molecule, began within seconds of platelet-RCM contact and was independent of vehicle composition. Since diatrizoate inhibited aggregation more than iopamidol or ioxaglate, its use may be of additional value during angiographic procedures in clinical situations involving enhanced platelet activation.     

Quantitative assessment of angiographic right ventricular wall motion in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C)

Introduction: Angiography of the right ventricle (RV) is a standard, reference technique to diagnose wall motion abnormalities in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). RV wall motion is usually assessed by qualitative, visual impression, and has lacked a quantitative basis for defining abnormalities. Since the normal RV has a markedly asymmetric movement, angiographic interpretation can differ, even among experienced clinicians. The purpose of this study was to quantify RV wall motion based on contrast ventriculography in patients with ARVD/C and to specify the severity and location of wall motion abnormalities, as compared with normal subjects.
Methods and Results: We analyzed the angiographic contours of the RV in three views from 19 normal subjects and 23 subjects with ARVD/C. Contour area movement during contraction was calculated circumferentially and further analyzed in nine zones. RV ejection fraction was also computed. Wall motion in ARVD/C was depressed by more than 30% at the tricuspid valve and inferior wall regions (P < 0.001) and significantly reduced at the apex (P = 0.003). However, the RVOT and anterior wall motion were not significantly reduced. RV ejection fraction was depressed from 60 ± 11% in normal subjects to 41 ± 12% in ARVD/C patients (P < 0.001).
Conclusion: Wall motion abnormalities in ARVD/C can be quantified and compared with normal controls, showing primarily reduced movement in the tricuspid and inferior wall regions. This study delineates objective measurements that can be used to aid in the diagnosis of ARVD/C. In addition, they may be incorporated in future refinements of criteria to diagnose ARVD/C.     

Angiogenic growth factors in preinvasive breast disease.

Recently, we showed that preinvasive breast pathologies, such as usual hyperplasia, atypical hyperplasia, and carcinoma in situ, have an increased vascularity when compared with normal breast tissue (S. C. Heffelfinger et al., Clinical Cancer Res., 2: 1873-1878, 1996). To understand the mechanism of this increased vascularity, we examined by immunohistochemistry each of these pathological lesions for the expression of angiogenic growth factors. These studies showed that normal breast tissue contains numerous angiogenic agents, particularly vascular endothelial cell growth factor and basic fibroblast growth factor. At the transition from normal epithelium to proliferative breast disease, insulin-like growth factor (IGF) II expression was increased, primarily in the stroma and infiltrating leukocytes. However, among proliferative tissues, IGF I decreased with increasing vascularity. Finally, both epithelial vascular endothelial growth factor and epithelial and leukocytic platelet-derived endothelial cell growth factor increased at the transition to carcinoma in situ, whereas stromal and leukocytic basic fibroblast growth factor were elevated only in invasive carcinoma. Therefore, during histological progression there is also a complex progression of angiogenic growth factors. For CIS, two forms of vascularity are found: stromal microvascular density (MVD), and vascularity associated with the epithelial basement membrane (vascular score). There was 35% discordance between these two measurement systems. Among carcinoma in situ cases, decreases in stromal IGF II were associated with increasing vascular scores but not MVD, and increases in platelet-derived endothelial cell growth factor were associated with increasing MVD but not the vascular score. The presence of discordance and differential association with specific angiogenic agents suggests that these two forms of vascularity may be differentially regulated.     

New assistive technology for passive standing

The anesthetic skin of patients with spinal cord injuries makes these patients a high-risk population for burn injuries. Innovations in rehabilitation engineering can now provide the disabled with mechanical devices that allow for passive standing. Passive standing has been shown to counteract many of the effects of chronic immobilization and spinal cord injury, including bone demineralization, urinary calculi, cardiovascular instability, and reduced joint range of motion and muscular tone. This article will describe several unique assistive devices that allow for passive standing and an improvement in daily living for people with disabilities.     

Production of a suppressor factor by human adherent cells treated with Mycobacterium tuberculosis: absence in systemic lupus erythematosus.

When human peripheral blood mononuclear cells are activated by mitogens in the presence of Mycobacterium tuberculosis (M. tuberculosis), considerable suppression of 3H-thymidine incorporation is observed. Proliferation of mononuclear cells from patients with SLE was not suppressed by treatment with mycobacteria. Analysis of suppressor effect indicated that normal peripheral blood adherent cells treated with mycobacteria release a soluble factor which activates a precursor cell population to become active suppressor T cells. Although lymphocytes from patients with SLE were responsive to suppressor factor produced by normal adherent cells treated with mycobacteria, SLE adherent cells were incapable of producing suppressor factor when treated in the same way. In order to determine whether the inability of SLE adherent cells to produce suppressor factor was due to the presence of immune complexes on the surface of these cells, SLE adherent cells were trypsinized or preincubated prior to treatment with mycobacteria. Neither of these manoeuvres restored the ability of SLE adherent cells to produce suppressor factor. Furthermore, normal adherent cells continued to produce the factor after prior treatment with varying concentrations of human serum albumin-anti-human serum albumin complexes. The results suggest that a basic adherent cell defect exists in SLE and that under certain circumstances this may give rise to a secondary defect of suppressor cell activation.     

MR Imaging of arrhythmogenic right ventricular cardiomyopathy: morphologic findings and interobserver reliability

BACKGROUND: Magnetic resonance (MR) imaging is frequently used to diagnose arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). However, the reliability of various MR imaging features for diagnosing ARVC/D is unknown. The purpose of this study was to determine which morphologic MR imaging features have the greatest interobserver reliability for diagnosing ARVC/D. METHODS: Forty-five sets of films of cardiac MR images were sent to 8 radiologists and 5 cardiologists with experience in this field. There were 7 cases of definite ARVC/D as defined by the Task Force criteria. Six cases were controls. The remaining 32 cases had MR imaging because of clinical suspicion of ARVC/D. Readers evaluated the images for the presence of (a) right ventricle (RV) enlargement, (b) RV abnormal morphology, (c) left ventricle enlargement, (d) presence of high T(1) signal (fat) in the myocardium, and (e) location of high T(1) signal (fat) on a Likert scale with formatted responses. RESULTS: Readers indicated that the Task Force ARVC/D cases had significantly more (chi(2) = 119.93, d.f. = 10, p < 0.0001) RV chamber size enlargement (58%) than either the suspected ARVC/D (12%) or no ARVC/D (14%) cases. When readers reported the RV chamber size as enlarged they were significantly more likely to report the case as ARVC/D present (chi(2)(= )33.98, d.f. = 1, p < 0.0001). When readers reported the morphology as abnormal they were more likely to diagnose the case as ARVC/D present (chi(2) = 78.4, d.f. = 1, p < 0.0001), and the Task Force ARVC/D (47%) cases received significantly more abnormal reports than either suspected ARVC/D (20%) or non-ARVC/D (15%) cases. There was no significant difference between patient groups in the reported presence of high signal intensity (fat) in the RV (chi(2) = 0.9, d.f. = 2, p > 0.05). CONCLUSIONS: Reviewers found that the size and shape of abnormalities in the RV are key MR imaging discriminates of ARVD. Subsequent protocol development and multicenter trials need to address these parameters. Essential steps in improving accuracy and reducing variability include a standardized acquisition protocol and standardized analysis with dynamic cine review of regional RV function and quantification of RV and left ventricle volumes.