Biomedical subjects
Publications and source records attributed to D R Kelly.
We report a case of bifocal rhabdomyosarcoma involving the hand and thigh in an 11-year-old female. We highlight the importance of a thorough clinical examination and an aggressive surgical approach in which each lesion is treated as a separate primary.
The authors present a case of a child with dwarfism that was noted to be developmentally delayed. Imaging revealed atlantoaxial instability, occult spinal dysraphism, and a presacral mass. Histopathology of the presacral lesion was that of a myxopapillary ependymoma with epidermoid cyst. We believe this to be the first report in the extant medical literature of this constellation of findings in the same patient. However, there are rare reports indicating a possible association of occult spinal dysraphism and the simultaneous occurrence of spinal ependymomas. Further case reports are necessary to discern whether these pathological entities are true low rate associations that the clinician should consider in their evaluation of these patients.
Percutaneous tracheostomy is a well established technique used primarily to assist weaning from mechanical ventilation on many intensive care units. We report our experiences of a total of 36 procedures performed with the new Blue Rhino Percutaneous Tracheostomy Introducer Set developed by Ciaglia. The technique was successful in all cases and was simpler and quicker to perform than with the earlier Ciaglia percutaneous tracheostomy set. Difficulties were encountered when using Shiley tracheostomy tubes. Significant complications included one posterior wall tear and one tracheal cartilage ring fracture.
OBJECTIVE: To examine the cellular mechanisms involved in the pathogenesis of necrotizing enterocolitis (NEC). SUMMARY BACKGROUND DATA: Necrotizing enterocolitis is a major cause of death and complications in neonates; the cellular mechanisms responsible for NEC are unknown. The inducible form of cyclooxygenase (i.e., COX-2) is activated by the transcription factor nuclear factor (NF)-kappaB and is thought to play a role in inflammation. METHODS: Segments of perforated and adjacent uninvolved small intestine from neonates with NEC were analyzed for COX-2 expression by immunohistochemistry. NEC was induced in weanling (18 days old) rats by occlusion of superior mesenteric vessels for 1 hour and intraluminal injection of platelet activating factor (50 micro/kg). Small intestine was harvested for protein extraction. Western immunoblot was performed to determine expression of COX-2. Gel shift assays were performed to assess NF-kappaB binding activity. RESULTS: Immunohistochemical analysis showed increased COX-2 protein expression in the perforated intestinal sections of all 36 neonates but not in adjacent normal intestine. Increased expression of COX-2 protein and NF-kappaB binding activity was noted in the small intestine of weanling rats at 0 and 3 hours after induction of NEC. CONCLUSIONS: Increased COX-2 expression was identified in all neonatal intestinal segments resected for perforated NEC. In addition, a coordinate induction of COX-2 expression and NF-kappaB binding was noted in a rodent model of NEC. These findings suggest that the COX-2/NF-kappaB pathway may play a role in the pathogenesis of NEC. Therapeutic agents that target this pathway may prove useful in the treatment or possible prevention of NEC.
Histological analysis of chronically stimulated human vagus nerves is lacking in the literature. In this study, we describe the first microscopic findings in a chronically stimulated left vagus nerve from a pediatric patient. Our results show many histological changes in and around the stimulated nerve with severe demyelination. Further long-term clinical and postmortem examinations of chronically stimulated vagus nerves in both children and adults are needed to ascertain whether prolonged exposure to electrical current can cause clinical dysfunction of this nerve.
BACKGROUND: Gastrointestinal autonomic nerve tumors (GANTs) are a subpopulation of gastrointestinal stromal tumors (GISTs) that are characterized by ultrastructural features resembling enteric autonomic nerve cells, without epithelial, Schwannian, or smooth muscle differentiation. Delineation of the clinicopathologic features of GANT in the pediatric population is lacking. METHODS: The clinicopathologic and outcome data for four pediatric patients with GANT are presented. The data from these patients and four previously reported pediatric patients are summarized and compared with data for GANT in adults. RESULTS: All four cases occurred in females at a mean age of 12.5 years. The primary tumor site was the stomach in all cases, and the mean tumor size was 6.3 cm. Immunocytochemical and ultrastructural examination were essential in distinguishing GANT from GIST in all cases by identifying features of neural origin (neuron specific enolase in all four cases, NFP in three cases, S-100 in two cases, dense core neurosecretory granules in all four cases, and neuritelike processes in all four cases), while failing to identify features of myogenic origin (no desmin, smooth muscle actin, myofilaments, or dense bodies were found in any of the cases). Primary treatment was surgical, with chemotherapy administered to 1 patient at the time of recurrence. All patients are alive after a mean follow-up of 60 months (range, 8 months to 9 years). CONCLUSIONS: Similarities of pediatric GANT to GANT in adults include the need for a high index of suspicion for diagnosis; comparable histopathologic, immunohistochemical, and ultrastructural features; and surgery as the primary therapy. Distinguishing features in children may be a prevalence among females in the second decade, a predominance of smaller gastric tumors, and a positive prognostic value of younger age.
OBJECT: To develop and evaluate the effect of having a personal learning log on Senior House Officers knowledge and confidence. METHODS: A multiple choice paper and a confidence checklist for two hospital specialties were developed to assess knowledge and confidence. These were administered to a control group and to an intervention group who had the learning log. Both groups completed an evaluation at the end of the post. SETTING: The study took place in Accident & Emergency and Obstetric & Gynaecology posts in Greater Glasgow and Lanarkshire. SUBJECTS: 79 Senior House Officers in Accident & Emergency and 78 Senior House Officers in Obstetrics & Gynaecology. RESULTS: The mean scores in the MCQ and the mode in the confidence checklist increased significantly in both specialties during the post, but there was no significant difference between the control and intervention groups. Forty two learning logs were returned at the end of the study and analysis of these revealed that there was great scope for learning but few documented the specific learning achieved. Evaluation of the posts revealed that some improvements had taken place in teaching and assessment frequency, however, there was scope for further improvement. CONCLUSION: While the problems of hospital training are well documented, an attempt to improve the situation using a learning log did not have a statistically significant impact on SHO knowledge or confidence. A six-month hospital post appears to present many opportunities for learning but these are not exploited. It is suggested that three things are needed. Firstly, active participation by and personalized feedback from a senior member of staff, with training where needed. Secondly, protected time for tutorials with a planned system of formative assessment, and thirdly, a more positive approach to learning by both SHOs and consultants. Once this occurs, a learning log may have a more significant impact on training.
PURPOSE: Benign bladder tumors are rare in children. A number of descriptive terms have previously been used to describe inflammatory tumors with myofibroblastic proliferation or eosinophilic infiltration. We present our experience with these tumors and review the literature. MATERIALS AND METHODS: We retrospectively reviewed the records of all children presenting with a benign focal bladder mass during the last 5 years, including 2 girls and 3 boys 2 to 12 years old (mean age 7). RESULTS: Presenting symptomatology included irritative voiding symptoms, suprapubic pain and hematuria. All bladder masses were diagnosed by ultrasonography and all patients underwent transurethral resection. Three children who had an inflammatory bladder tumor with myofibroblastic features required open tumor excision with preservation of the bladder. In the 2 remaining children urine culture was positive preoperatively and the diagnosis was an inflammatory bladder tumor with eosinophilic infiltration. Transurethral resection of the mass was performed without partial cystectomy. CONCLUSIONS: Inflammatory myofibroblastic and eosinophilic tumors represent forms of focal cystitis with a tumefactive component. Differentiation from the malignant bladder neoplasms of childhood has important consequences for therapy. Management of these benign but aggressive inflammatory lesions involves local control by endoscopic or open surgery with bladder preservation. We encourage refined use of the terminology for inflammatory myofibroblastic and eosinophilic tumors.
Epidermoid cysts are unusual benign cysts that occur in the oral cavity less than 2% of the time. Epidermoid cysts isolated to the uvula are rare. A review of the literature has revealed only three confirmed cases of isolated uvular epidermoid cysts. We present a series of three such cases, two of which presented with significant symptomatology. The diagnosis and management of these unusual lesions will be discussed, as well as the differential diagnosis.
OBJECTIVES: Production of nitric oxide via the cytokine-mediated activation of myocardial inducible nitric oxide synthase decreases myocardial contractility. Whether myocardial dysfunction is mediated directly by nitric oxide or indirectly through the formation of secondary reaction products, such as peroxynitrite, has not been established. Peroxynitrite, but not nitric oxide, reacts with the phenolic ring of tyrosine to form the stable product 3-nitro-L-tyrosine. Demonstration of tissue nitrotyrosine residues, therefore, infers the presence of peroxynitrite or related nitrogen-centered oxidants. DESIGN: Retrospective analysis of human autopsy specimens. SETTING: University pathology and basic science laboratories. PATIENTS: Formalin-fixed, paraffin-embedded myocardial tissue samples were obtained from 11 patients with a diagnosis of sepsis, seven patients with a diagnosis of viral myocarditis, and five control patients without clinical or pathologic cardiac disease. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Specific antibodies to nitrotyrosine were utilized to detect nitrotyrosine residues in human autopsy specimens. Cardiac tissue obtained from patients with myocarditis or sepsis demonstrated intense nitrotyrosine immunoreactivity in the endocardium, myocardium, and coronary vascular endothelium and smooth muscle. In contrast, connective tissue elements were without appreciable immunohistochemical staining. Nitrotyrosine antibody binding was blocked by coincubation with nitrotyrosine or nitrated bovine serum albumin, but not by aminotyrosine, phosphotyrosine, or bovine serum albumin. In situ reduction of tissue nitrotyrosine to aminotyrosine by sodium hydrosulfite also blocked antibody binding. Densitometric analysis of nitrotyrosine immunoreactivity demonstrated significantly higher values for specimens from myocarditis and sepsis patients when compared with control tissue specimens. CONCLUSION: These results demonstrate the formation of peroxynitrite within the myocardium during inflammatory disease states, suggesting a role for peroxynitrite in inflammation-associated myocardial dysfunction.
To assess training and operative practice in minor surgery a postal questionnaire was sent to all general practitioners practising in the Scottish Highlands and Western Isles in 1992. Information was requested regarding the type and adequacy of surgical training, operations performed, the desire for surgical skills training and possible methods of assessment. Seventy per cent (144/205) of general practitioners (GPs) replied to the questionnaire. Teaching in minor surgery had been received by 74% of GPs (107/144), yet 43% (62) considered their training inadequate. Although confident to suture simple wounds or excise skin lesions from the trunk, significantly fewer were confident to excise such lesions from the face (P < 0.001, 1 df, Chi square test). From 86% of GPs (124/144) who wished to attend a training course on minor surgery, 62% (77) would prefer to be taught on patients and 36% (45) on a realistic skin simulator. Assessment of technical competence by a hospital consultant was considered desirable by 56% (80/144) either on patients 40% (57), or using a skin simulator 38% (54). While most GPs receive some training in minor surgery, there is a perceived need for improved training. The use of a skin simulator may allow both the teaching and assessment of surgical competence for GPs who undertake minor surgery.
The metastatic potential of undifferentiated neuroblastomas is typically lost when differentiation into ganglioneuroblastomas occurs spontaneously or is induced. Cell adhesion may play a role in metastasis, and we have shown recently that expression of integrin alpha v beta 5 protein and mRNA is up-regulated in ganglioneuroblastomas in vivo. To investigate whether interactions of alpha v beta 5 with matrix components play a role in the loss of metastatic potential, we used immunohistochemical and in situ hybridization to analyze neuroblastic tumors at various stages of differentiation for expression of the alpha v beta 5 ligands, vitronectin and osteopontin, and determined the ability of vitronectin to promote attachment and neurite outgrowth in vitro in a retinoic-acid-differentiated neuroblastoma cell model. We found that vitronectin, but not osteopontin, was expressed in 5 of 5 ganglioneuroblastomas but was absent or weakly expressed in 6 of 6 undifferentiated neuroblastomas. Neuronal cell vitronectin was detected in 7 of 9 ganglioneuromas, 5 of 8 peripheral ganglia, and 14 of 21 adrenal gland medullae, confirming expression of vitronectin in mature peripheral neurons. In vitro, vitronectin promoted attachment of both undifferentiated and retinoic-acid-differentiated neuroblastoma cells, which was inhibited 20 and 60%, respectively, by monoclonal antibody anti-integrin alpha v beta 5. Vitronectin-promoted neurite outgrowth of retinoic-acid-differentiated neuroblastoma cells was not inhibited by monoclonal antibody anti-alpha v beta 5. These data suggest that the synthesis of vitronectin and the ability of integrin alpha v beta 5 to mediate vitronectin adhesion on retinoic-acid-differentiated neuroblastoma cells may promote differentiation of neuroblastoma cells in vivo.
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The behaviours of organisms as diverse as elephants and butterflies are affected by pheromones with identical or similar structures. Recent developments in the molecular biology of pheromone detection suggest why.
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