EGFR mutations in exons 18-21 in sporadic breast cancer.
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Biomedical subjects
Publications and source records attributed to J W Moore.
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Long-term complications of surgical repair of Tetralogy of Fallot include atrial arrhythmias. These can be difficult to treat, and loss of sinus rhythm can lead to profound hemodynamic consequences in the presence of residual structural abnormalities. We describe the first report of high-energy external cardioversion in a 46-year-old man with repaired tetralogy of Fallot with atrial fibrillation refractory to conversion with normal energy. This represents an alternative to internal cardioversion or rate control for these patients.
In this report, we describe the clinical and neuropathological features of a case of familial frontotemporal dementia (FTD), with onset at 58 years of age and disease duration of 10 years, associated with a novel mutation, Q336R, in the tau gene (tau). In vitro studies concerning the properties of tau proteins bearing this mutation, with respect to microtubule assembly and tau filament aggregation, are reported. Clinically, the patient showed alterations in memory, language and executive functions and marked behavioural change consistent with FTD, although the extent of memory impairment was more than is characteristic of FTD. At autopsy, there was degeneration of the frontal and temporal lobes associated with the presence of hyperphosphorylated tau proteins in swollen (Pick) cells and intraneuronal inclusions (Pick bodies). By immunohistochemistry, the Pick bodies contained both 3-repeat and 4-repeat tau proteins although, because no fresh tissues were available for analysis, the exact isoform composition of the aggregated tau proteins could not be determined. Neurons within frontal cortex contained neurofibrillary tangle-like structures, comprising both straight and twisted tubules, or Pick bodies in which the filaments were short and randomly orientated. In vitro, and in common with other tau missense mutations, Q336R caused an increase in tau fibrillogenesis. However, in contrast to most other tau missense mutations, Q336R increased, not decreased, the ability of mutant tau to promote microtubule assembly. Nonetheless, this latter functional change may likewise be detrimental to neuronal function by inducing a compensatory phosphorylation that may yield increased intracellular hyperphosphorylated tau species that are also liable to fibrillize. We believe the mutation is indeed pathogenic and disease causing and not simply a coincidental rare and benign polymorphism. Since this mutation is segregating with the FTD clinical and neuropathological phenotype, it has not been found in unaffected individuals and it has novel functional properties in vitro which are likely to be detrimental to neuronal function in vivo.
Pediatric interventional catheterization is an expanding specialty with a range of mature, emerging, and investigative procedures and technologies. Many dysfunctional obstructions and/or shunts caused by congenital heart defects may be treated or significantly palliated in the catheterization laboratory. These include valvar pulmonary or aortic stenosis, the patent ductus arteriosus, coarctation of the aorta, branch pulmonary stenosis, atrial septal defects and even ventricular septal defects. Valve replacement technology, approaches to complex heart diseases such as single ventricle, and fetal interventions are subjects of active investigations. A comprehensive review of the present and future of interventional pediatric cardiology is presented.
OBJECTIVE: To examine the pattern of cognitive decline in early Huntington's disease (HD). METHODS: The authors studied 61 patients with mild to moderate HD who had at least three annual neuropsychological assessments using the Core Assessment Program for Intracerebral Transplantation in Huntington's Disease short battery. A subset of 34 patients had additional neuropsychological tests, and another subset of 21 patients was assessed annually on the Cambridge Neuropsychological Test Automated Battery. Neuropsychological measures that changed significantly over time were submitted to a multiple analysis of covariance to explore associations with demographic and neurologic indices. RESULTS: Patients showed a progressive impairment in attention, executive function, and immediate memory, with timed tests of psychomotor skill being particularly sensitive to decline. In contrast, general cognition, semantic memory, and delayed recall memory were relatively unaffected. CONCLUSION: The profile of cognitive performance shows selective and progressive dysfunction of attention and executive function in patients with mild to moderate HD, consistent with frontostriatal pathology at this stage of disease.
Three cases of unilateral right-sided pulmonary venous atresia were evaluated over an 18-year period. These bring the total number of cases to 25 in the literature. The clinical presentation of all these patients was similar and consisted of recurrent pulmonary infections, asthma-like symptoms, and exercise intolerance. The patients presented in 1982 (patient 1, a 12-year-old boy), 1994 (patient 2, a 9-year-old girl), and 1999 (patient 3, a 13-year-old boy). All patients were evaluated with a chest roentgenogram, and patients 1 and 2 had a ventilation and perfusion scan. Patients 1 and 3 also had cardiac catheterization and pulmonary angiography. Patient 2 had a magnetic resonance imaging study of the chest. Only patient 3 had wedge pulmonary angiography. Although a rare congenital defect, this diagnosis should be strongly suspected based on the typical clinical presentation and the preliminary studies, such as the chest roentgenogram and ventilation and perfusion scan. However, for definitive diagnosis, cardiac catheterization with wedge pulmonary angiography is necessary. Anastomosis of the atretic pulmonary veins to the left atrium is a theoretical consideration. However, this may not be feasible due to pulmonary venous anatomy or significant pulmonary dysfunction with pulmonary vascular changes. In these circumstances, we recommend performing pneumonectomy to remove the nidus for repeated bouts of pulmonary infections, to eliminate the left-to-right shunt, and to eliminate the dead space contributing to exercise intolerance.
Many oncogenes induce expression of vascular endothelial growth factor (VEGF), a key factor in tumor angiogenesis. Phosphatidylinositol 3'-kinase (PI3K)/Akt is a common signaling pathway for oncogenes and tumor suppressor genes and is involved in VEGF regulation. Because hypoxia is a major stimulus for VEGF production, we examined the effects of LY294002, a selective PI3K inhibitor, on hypoxia-inducible factor (HIF)-1alpha and HIF-2alpha expression and on endogenous VEGF responses to hypoxia. A panel of breast cancer cell lines reflecting the different genetic changes occurring in human breast cancer was analyzed. LY294002 inhibited HIF-1alpha induction and phosphorylation under hypoxia. However, HIF-2alpha expression was not affected. Basal and hypoxia-inducible VEGF expression was reduced at both mRNA and protein levels by 50%. V12-ras overexpression resulted in an increase in hypoxia-induced HIF-1alpha and HIF-2alpha expression. This effect was blocked by PI3K inhibitor, demonstrating one mechanism for ras synergy with hypoxia-mediated induction of genes. The decreased HIF-1alpha expression was not dependent on VHL interaction because a renal carcinoma cell line with VHL mutation and constitutive high HIF-1alpha expression also showed down-regulation of HIF-1alpha after treatment with LY294002. These results have implications for the use of PI3K inhibitors to inhibit synergistic effects of hypoxia with a wide range of common oncogenes.
The purpose of this study was to evaluate the safety and the efficacy of transcatheter patent ductus arteriosus (PDA) occlusion with the Duct-Occlud device. Six centers participated in this phase I U.S. Food and Drug Administration-approved clinical trial with investigational device exemption. Patients with restrictive PDA (less than 4-mm minimum diameter) were eligible for the study. Sixty-two patients were enrolled. Forty-eight patients had successful implantation of Duct-Occlud devices. Patient follow-up evaluations were conducted at hospital discharge and after 2 and 12 months. At discharge and after 1 year, all patients had clinical PDA closure. Closure assessed by color flow Doppler was 55% at discharge, 88% at 2 months, and 94% at 1 year. There were no complications related to implantation or noted in follow-up evaluations. The Duct-Occlud device is safe and efficacious for the closure of small- to moderate-size patent ductus arteriosus.
The successful employment of embolization coils for transcatheter occlusion of the patent ductus arteriosus (PDA) has resulted in acceptance of transcatheter occlusion as the treatment of choice for small to medium-sized PDAs. The Duct-Occlud device was developed to further improve the technique by utilizing a controlled release mechanism and coil shape specifically designed for the geometry of the ductus arteriosus. Clinical studies have demonstrated excellent efficacy with low embolization rates and low incidences of complications. Newer modifications have been designed for occlusion of larger PDAs and subaortic ventricular septal defects, and preliminary clinical results have been promising.
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In the antecedent functional assessment literature, researchers have introduced task demands and social attention simultaneously while varying the level of task difficulty. Though research has demonstrated situations in which a combination of social and task antecedents occasion socially avoidant responses from children with disabilities, no current studies have been offered to assess the impact of high levels of adult attention devoid of task demands on problem behaviors exhibited by children of typical development. A multiple element design was used to assess the specific effects of task and social antecedents on the problem behaviors of four children of typical development. Results identified two children whose behavior was associated with a combination of difficult task demands and attention in the form of commands and redirections and two children whose behavior was associated only with high levels of adult attention that did not include commands or redirections. These results suggest that antecedent functional assessment procedures can assess the impact of high levels of attention without the presence of task demands.
After a functional analysis indicated that aggression of an 8-year-old boy with autism was maintained by access to preferred items, antecedent manipulations involving the relative preference of restricted and noncontingently available stimuli were conducted. Restricting highly preferred items evoked the highest rates of aggression regardless of the preference level of the noncontingently available alternative items. Restricting less preferred stimuli was associated with moderate rates of aggression even when the alternative items were more preferred.
A patient with d-transposition of the great arteries who underwent the Mustard operation at one year of age developed intermittent symptomatic cyanosis as a young adult. Evaluation demonstrated a large baffle leak with bidirectional flow and stenosis of the intra-atrial IVC baffle channel. Initially, a single stent was placed to relieve the obstruction, followed by placement of an Amplatzer septal occluder device which assumed suboptimal position after release. Placement of additional stents securely repositioned the ASD device into excellent position, resulting in complete occlusion of the baffle leak and no residual obstruction in the IVC channel.
Hypoxia is an important regulator of vascular endothelial growth factor (VEGF) expression, and VEGF is associated with poor prognosis in bladder cancer. To investigate further the mechanisms of VEGF regulation, we examined VEGF expression by mRNA and protein analysis in four human bladder cancer cell lines, showing a progression from well to poorly differentiated phenotypes under varying conditions of confluence and hypoxia (0.1% O(2)) and with chemical mimics of hypoxia. Hypoxia significantly increased VEGF protein expression in all cell lines, although this effect was dependent on the degree of confluence. The superficial bladder cancer cell line RT4 lost hypoxia inducibility at confluence, whereas inducibility was maintained in the invasive cell lines 253J and EJ28. This pattern of VEGF expression in the invasive cell lines correlated with the expression of the transcription factor hypoxia inducible factor-1 alpha (HIF-1 alpha) and with hypoxia-inducible factor-2 alpha (HIF-2 alpha) and in RT4 correlated with a marked reduction in HIF-1 alpha inducibility at confluence. Using the phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor LY 294002, we show that this VEGF hypoxia-inducible pathway regulated by HIF-1 alpha is distinct from a PI 3-kinase-dependent pathway, which regulates basal amounts of VEGF, but does not affect inducibility. Both HIF-1 alpha and HIF-2 alpha protein and mRNA were up-regulated in primary human bladder tumors (n = 12) compared with normal bladder specimens (n = 4), with significant intertumor variation. These results suggest that components of the hypoxia response pathway, including HIF-1 alpha and HIF-2 alpha, are important cofactors in the regulation of VEGF in bladder cancer and are therapeutic targets in this disease.
Hypoxia-inducible factors (HIF-1 and HIF-2) are two closely related protein complexes that activate transcription of target genes in response to hypoxia. Expression of HIF-1alpha and HIF-2alpha and their effects on survival under hypoxia were studied in six human breast cancer cell lines. We also evaluated the basal and inducible expression of two hypoxically regulated genes, vascular endothelial growth factor (VEGF) and lactate dehydrogenase-A (LDH-A). All of the cell lines studied expressed HIF-1alpha at various levels, but HIF-2alpha was low or absent from the more aggressive cell lines. There was an inverse correlation between HIF-1alpha and HIF-2alpha induction and clonogenic survival under hypoxia. Thus, cell lines with reduced induction of HIF-1alpha or HIF-2alpha showed high basal levels of VEGF and improved survival under hypoxia. A reduction in HIF expression was also associated with a more aggressive phenotype in vivo. To confirm these results, we carried out stable transfection of the MDA 435 cell line with human HIF-2alpha cDNA. There was no change in the growth rate in monolayer culture. However, in vitro growth as colonies and in vivo tumor growth of the HIF-2alpha overexpressing cells were significantly impaired compared with the control transfectants. Thus, despite the fact that HIF proteins are necessary for optimal tumor growth and angiogenesis in vivo, overexpression of these molecules seems detrimental to tumor growth. A balance between the angiogenic and tumor-inhibiting levels of HIF proteins may, therefore, be necessary for optimal tumor growth.
The aim of this study was to review contemporary techniques, devices, and results of transcatheter occlusion of surgical shunts in 2 pediatric cardiac programs. Closure of superfluous surgical shunts may reduce cardiac work and risk of endocarditis. Previous studies have shown that transcatheter closure of shunts is feasible, but have not demonstrated acceptable efficacy or safety. In addition, the performance of new techniques and devices has not been reviewed. Between 1993 and 1998, 18 patients with congenital heart disease underwent transcatheter closure of 19 Blalock-Taussig shunts. Detachable and standard Gianturco coils and Gianturco-Grifka vascular occlusion devices were employed. All 19 shunts had complete closure. Eight shunts had initial placement of detachable coils. Five shunts had stents placed that bridged the pulmonary end of the shunts. These 5 and 4 additional shunts had closure by standard coils. Two shunts were closed with Gianturco-Grifka devices. There were no complications, no embolizations, and no requirement for surgery precipitated by the procedures. This review of contemporary techniques, devices, and results suggests that transcatheter occlusion of surgical shunts is effective and safe.
Percutaneous occlusion of superfluous vascular connections, which are short and have large caliber, is technically difficult. We report use of a composite device (consisting of a Palmaz stent, a Gianturco Grifka vascular occlusion device, and multiple platinum detachable embolization coils) to close a large left superior vena cava draining to the pulmonary venous atrium.
An occasional complication of redilating stents placed in children is false aneurysm. We report the use of covered stents to treat a false aneurysm of the abdominal aorta in an adolescent girl with neurofibromatosis and abdominal coarctation of the aorta.