DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 1 2000
Mika Kamimura
A homolog of retinoid X receptors (RXR), named PmRXR, was cloned from the budding ascidian, Polyandrocarpa misakiensis. Gel-shift assays revealed that PmRXR and a previously identified P. misakiensis retinoic acid receptor (PmRAR) formed a complex to bind vertebrate-type retinoic acid response element (RARE). Transfection assays were carried out using a reporter gene containing a RARE upstream of lacZ. Two chimeric effector genes were constructed by placing PmRXR and PmRAR cDNA fragments (containing the DNA-binding, ligand-binding and ligand-dependent transactivation domains) downstream of the human RXR, and RAR, cDNA (covering the N-terminal coding region), respectively. Each chimeric cDNA was ligated to a notochord-specific enhancer. In case the embryos were transfected with all three transgenes and treated with retinoic acid (RA), the reporter gene was activated in the notochord cells. The result suggests that the PmRXR/PmRAR complex functions as an RA-dependent transcriptional activator. The PmRXR mRNA was detected in a mesenchymal cell type, called glomerulocyte, in the developing Polyandrocarpa bud. As this cell type has been shown to express PmRAR mRNA, it seems possible that the PmRXR/PmRAR complex mediates RA signaling in this cell type to induce the expression of genes involved in the morphogenesis of the developing bud. [source]

Conserved RARE localization in amphioxus Hox clusters and implications for Hox code evolution in the vertebrate neural crest

DEVELOPMENTAL DYNAMICS, Issue 6 2006
Hiroshi Wada
Abstract The Hox code in the neural crest cells plays an important role in the development of the complex craniofacial structures that are characteristic of vertebrates. Previously, 3, AmphiHox1 flanking region has been shown to drive gene expression in neural tubes and neural crest cells in a retinoic acid (RA)-dependent manner. In the present study, we found that the DR5-type RA response elements located at the 3, AmphiHox1 flanking region of Branchiostoma floridae are necessary and sufficient to express reporter genes in both the neural tube and neural crest cells of chick embryos, specifically at the post-otic level. The DR5 at the 3, flanking region of chick Hoxb1 is also capable of driving the same expression in chick embryos. We found that AmphiHox3 possesses a DR5-type RARE in its 5, flanking region, and this drives an expression pattern similar to the RARE element found in the 3, flanking region of AmphiHox1. Therefore, the location of these DR5-type RAREs is conserved in amphioxus and vertebrate Hox clusters. Our findings demonstrate that conserved RAREs mediate RA-dependent regulation of Hox genes in amphioxus and vertebrates, and in vertebrates this drives expression of Hox genes in both neural crest and neural tube. This suggests that Hox expression in vertebrate neural crest cells has evolved via the co-option of a pre-existing regulatory pathway that primitively regulated neural tube (and possibly epidermal) Hox expression. Developmental Dynamics 235:1522,1531, 2006. © 2006 Wiley-Liss, Inc. [source]

Retinoids directly activate the collagen X promoter in prehypertrophic chondrocytes through a distal retinoic acid response element

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2006
Arthur J. Cohen
Abstract Retinoids are essential for the terminal differentiation of chondrocytes during endochondral bone formation. This maturation process is characterized by increased cell size, expression of a unique extracellular matrix protein, collagen X, and eventually by mineralization of the matrix. Retinoids stimulate chondrocyte maturation in cultured cells and experimental animals, as well as in clinical studies of synthetic retinoids; furthermore, retinoid antagonists prevent chondrocyte maturation in vivo. However, the mechanisms by which retinoids regulate this process are poorly understood. We and others showed previously that retinoic acid (RA) stimulates expression of genes encoding bone morphogenetic proteins (BMPs), suggesting that retinoid effects on chondrocyte maturation may be indirect. However, we now show that RA also directly stimulates transcription of the collagen X gene promoter. We have identified three RA response element (RARE) half-sites in the promoter, located 2,600 nucleotides upstream from the transcription start site. These three half-sites function as two overlapping RAREs that share the middle half-site. Ablation of the middle half-site destroys both elements, abolishing RA receptor (RAR) binding and drastically decreasing RA stimulation of transcription. Ablation of each of the other two half-sites destroys only one RARE, resulting in an intermediate level of RAR binding and transcriptional stimulation. These results, together with our previously published data, indicate that retinoids stimulate collagen X transcription both directly, through activation of RARs, and indirectly, through increased BMP production. J. Cell. Biochem. © 2006 Wiley-Liss, Inc. [source]

Interactive magnetic resonance cholangiography (MRC) with adaptive averaging,

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2006
Martin J. Graves MSc
Abstract Purpose To implement and evaluate a technique for adaptively averaging 2D magnetic resonance cholangiography (MRC) images obtained using an interactive imaging system with a view to improving image quality at reduced fields of view (FOVs). Materials and Methods Images were obtained using an interactive implementation of a single-shot half-Fourier rapid acquisition with relaxation enhancement (RARE) technique. Software was developed for adaptively averaging images, and an evaluation was performed in a phantom and a cohort of 10 patients referred for standard MRC. Adaptively averaged and standard single-shot MRC images were evaluated with respect to their ability to demonstrate the common bile duct and main left and right intrahepatic duct branches. Results In all patient studies there was no difference in the ability of either the adaptive technique or the standard single-shot method to demonstrate the common bile duct and the main left and right intrahepatic duct branches. However, in seven of the 10 patient studies the adaptive technique provided better visualization of the peripheral bile duct system (P = 0.035; sign test). There was no difference in the diagnostic confidence of the two techniques (P = 0.32, Wilcoxon signed-rank test). Conclusion Adaptive averaging of MRC images obtained using an interactive imaging paradigm significantly improves visualization of peripheral intrahepatic ducts. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source]

Comparison of conventional fast spin echo, single-shot two-dimensional and three-dimensional half-fourier RARE for T2-weighted female pelvic imaging

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2004
Hiroshi Sugimura MD
Abstract Purpose To evaluate the usefulness of the three-dimensional half-Fourier RARE sequence in comparison with single-shot two-dimensional half-Fourier RARE and conventional fast spin echo (FSE) for female pelvic imaging. Materials and Methods Imaging with all sequences was performed in 146 patients with 166 focal lesions on a 1.5-T system. The images were compared on the basis of quality, lesion conspicuity, and lesion to the uterus contrast-to-noise ratio (CNR). Results The sharpness of intrapelvic organs on the three-dimensional half-Fourier RARE sequence was better than that on two-dimensional half-Fourier RARE and worse than that on FSE. Motion-related artifacts for three-dimensional half-Fourier RARE were more frequent than those for two-dimensional half-Fourier RARE. There was no statistical difference between the three-dimensional half-Fourier RARE sequence and FSE in regard to lesion conspicuity and overall image quality. The CNR of leiomyoma to myometrium and cervical cancer to cervical stroma was the highest with three-dimensional half-Fourier RARE (P< 0.05). Conclusion The three-dimensional half-Fourier RARE sequence generates images with higher contrast and better image resolution than two-dimensional-RARE. The three-dimensional data set provided images that can be observed in any orientation without acquiring an additional scan by using the multiplanar reconstruction (MPR) method. J. Magn. Reson. Imaging 2004;19:349,355. © 2004 Wiley-Liss, Inc. [source]

Implications of bulk motion for diffusion-weighted imaging experiments: Effects, mechanisms, and solutions

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2001
David G. Norris PhD
Abstract This review article describes the effect of bulk motion on diffusion-weighted imaging experiments, and examines methods for correcting the resulting artifacts. The emphasis throughout the article is on two-dimensional imaging of the brain. The effects of translational and rotational motion on the MR signal are described, and the literature concerning pulsatile brain motion is examined. Methods for ameliorating motion effects are divided into three generic categories. The first is methods that should be intrinsically insensitive to macroscopic motion. These include motion-compensated diffusion-weighting schemes, single-shot EPI, projection reconstruction, and line scanning. Of these, only single-shot EPI and projection reconstruction methods can obtain high-quality images without compromising on sensitivity. The second category of methods is those that can be made insensitive to bulk motion. The methods examined here are FLASH and RARE. It is shown that for both sequences motion insensitivity is in general attained only at the cost of a 50% reduction in sensitivity. The final set of methods examined are those that correct for motion, primarily navigator echoes. The properties and limitations of the navigator echo approach are presented, as are those of methods which attempt to correct the acquired data by minimizing image artifacts. The review concludes with a short summary in which the current status of diffusion imaging in the presence of bulk motion is examined. J. Magn. Reson. Imaging 2001;13:486,495. © 2001 Wiley-Liss, Inc. [source]

On the application of a non-CPMG single-shot fast spin-echo sequence to diffusion tensor MRI of the human brain

MAGNETIC RESONANCE IN MEDICINE, Issue 1 2002
Mark E. Bastin
Abstract The strong sensitivity of Carr-Purcell-Meiboom-Gill (CPMG) fast spin-echo (FSE) sequences, such as rapid acquisition with relaxation enhancement (RARE), to the phase of the prepared transverse magnetization means that artifact-free single-shot diffusion-weighted images can currently only be obtained with a 30,50% reduction in the signal-to-noise ratio (SNR). However, this phase sensitivity and signal loss can be addressed in FSE sequences that use quadratic phase modulation of the radiofrequency (RF) refocusing pulses to generate a sustained train of stable echoes. Here the first application of such a non-CPMG single-shot FSE (ssFSE) sequence to diffusion tensor MR imaging (DT-MRI) of the human brain is described. This approach provides high SNR diffusion-weighted images that have little or no susceptibility to poor B0 magnetic field homogeneity and the strong eddy currents typically present in DT-MRI experiments. Magn Reson Med 48:6,14, 2002. © 2002 Wiley-Liss, Inc. [source]

Transcriptional regulation of connexin 43 expression by retinoids and carotenoids: Similarities and differences

MOLECULAR CARCINOGENESIS, Issue 2 2005
Alex L. Vine
Abstract Gap junctions, connexons, are formed by assembly of trans-membrane connexin proteins and have multiple functions including the coordination of cell responses. Most human tumors are deficient in gap junctional communication (GJC) and restoration of GJC by forced expression of connexins reduces indices of neoplasia. Expression of connexin 43 (Cx43), the most widely-expressed connexin family member, is upregulated by cancer-preventive retinoids and carotenoids in normal and preneoplastic cells; an action considered of mechanistic significance. However, the molecular mechanism for upregulated expression is poorly understood. The retinoic acid receptor antagonist Ro 41-5253 was capable of suppressing retinoid-induction Cx43 luciferase reporter construct in F9 cells, but did not suppress reporter activity induced by the non-pro-vitamin A carotenoids astaxanthin or lycopene, indicating that retinoids have separate mechanisms of gene activation than non-pro-vitamin A carotenoids. Neither class of compound required protein synthesis for induction of Cx43 mRNA, nor was the 5.0 h half-life of Cx43 mRNA altered, indicating direct transcriptional activation. The responsive region was found within ,158 bp and +209 bp of the transcription start site; this contains a Sp1/Sp3 GC-box to which Sp1 and Sp3 were bound, as revealed by electrophoretic mobility shift assays (EMSA), but no retinoic acid response element (RARE). Site directed mutagenesis of this GC-box resulted in increased basal levels of transcription and loss of responsiveness to a synthetic retinoid. In this construct astaxanthin and lycopene produced marginally, but not significantly higher, reporter activity than the control. © 2005 Wiley-Liss, Inc. [source]

Assessing the Effectiveness of Reserve Acquisition Programs in Protecting Rare and Threatened Species

CONSERVATION BIOLOGY, Issue 6 2006
WILL R. TURNER
Lake Wales Ridge (Florida); especies en peligro; índice de protección; Lista Roja IUCN; matorral Abstract:,Measuring the effectiveness of reserve networks is essential to ensure that conservation objectives such as species persistence are being met. We devised a new approach for measuring the effectiveness of land conservation in protecting rare and threatened species and applied it to an ecosystem of global significance. We compiled detailed global distributional data for 36 rare and threatened plants and animals found in the Lake Wales Ridge ecosystem in central Florida (U.S.A.). For each species, we developed a set of protection indices based in part on criteria used to categorize species for the World Conservation Union's Red List. We calculated protection indexes under three different conservation scenarios: a past scenario, which assumed recent, major land-acquisition efforts never occurred; a current scenario, which assumed no additional areas are saved beyond what is currently protected; and a targeted scenario, which assumed all of the remaining areas targeted for protection are eventually acquired. This approach enabled us to quantify the progress, in terms of reduced risk of extinction, that conservationists have made in protecting target species. It also revealed the limited success these land-acquisition efforts have had in reducing those extinction risks associated with loss of habitat or small geographic ranges. Many species of the Lake Wales Ridge will remain at high risk of extinction even if planned land-acquisition efforts are completely successful. By calculating protection indexes with and without each site for all imperiled species, we also quantified the contribution of each protected area to the conservation of each species, enabling local conservation decisions to be made in the context of a larger (global) perspective. The protection index approach can be adapted readily to other ecosystems with multiple rare and threatened species. Resumen:,La cuantificación de la efectividad de las redes de reservas es esencial para asegurar que objetivos, como la persistencia de especies, se cumplan. Diseñamos un nuevo método para medir la efectividad de la conservación de tierras en la protección de especies raras y amenazadas y lo aplicamos a un ecosistema de importancia global. Compilamos datos detallados de la distribución global de 36 especies raras y amenazadas de plantas y animales que se encuentran en el ecosistema de la Lake Wales Ridge en el centro de Florida (E.U.A.). Para cada especie desarrollamos un conjunto de índices de protección basado parcialmente en criterios utilizados para clasificar especies para la Lista Roja de la Unión Mundial para la Naturaleza. Calculamos los índices de protección bajo tres escenarios de conservación distintos: un escenario pasado, que asumía que los esfuerzos recientes de adquisición de tierras nunca ocurrieron; un escenario actual, que asumía que no se protegen áreas adicionales a las ya conservadas; y un escenario deseado, que asumía que todas las áreas consideradas para ser protegidas son adquiridas eventualmente. Este método nos permitió cuantificar el progreso, en términos de la reducción del riesgo de extinción, en la protección de las especies obtenido por conservacionistas. También reveló el éxito limitado de los esfuerzos de adquisición de tierras en la disminución de los riesgos de extinción asociados con la pérdida de hábitat o con rangos geográficos pequeños. Se pronosticó que muchas especies de la Lake Wales Ridge permanecerán en alto riesgo aun si los esfuerzos de adquisición de tierra planificados son completamente exitosos. Al calcular los índices de protección con y sin cada sitio para todas las especies en peligro, también cuantificamos la contribución de cada área protegida a la conservación de cada especie, lo que permite que las decisiones de conservación se tomen en el contexto de una perspectiva mayor (global). El método del índice de protección se puede adaptar fácilmente a otros ecosistemas con múltiples especies raras y amenazadas. [source]

Specific Epileptic Syndromes Are Rare Even in Tertiary Epilepsy Centers: A Patient-oriented Approach to Epilepsy Classification

EPILEPSIA, Issue 3 2004
Christoph Kellinghaus
Summary: Purpose: To assess the practicability and reliability of a five-dimensional patient-oriented epilepsy classification and to compare it with the International League Against Epilepsy (ILAE) classification of epilepsy and epileptic syndromes. The dimensions consist of the epileptogenic zone, semiologic seizure type(s), etiology, related medical conditions, and seizure frequency. Methods: The 185 epilepsy patients (94 adults, 91 children, aged 18 years or younger) were randomly selected from the database of a tertiary epilepsy center and the general neurological department of a metropolitan hospital (28 adults). The charts were reviewed independently by two investigators and classified according to both the ILAE and the patient-oriented classification. Interrater reliability was assessed, and a final consensus among all investigators was established. Results: Only four (4%) adults and 19 (21%) children were diagnosed with a specific epilepsy syndrome of the ILAE classification. All other patients were in unspecific categories. The patient-oriented classification revealed that 64 adults and 56 children had focal epilepsy. In an additional 34 adults and 45 children, the epileptogenic zone could be localized to a certain brain region, and in 14 adults and five children, the epileptogenic zone could be lateralized. Fourteen adults and 21 children had generalized epilepsy. In 16 adults and 14 children, it remained unclear whether the epilepsy was focal or generalized. Generalized simple motor seizures were found in 66 adults and 52 children, representing the most frequent seizure type. Etiology could be determined in 40 adults and 45 children. Hippocampal sclerosis was the most frequent etiology in adults (10%), and cortical dysplasia (9%), in children. Seven adults and 31 children had at least daily seizures. Seventeen adults and 26 children had rare or no seizures at their last documented contact. The most frequent related medical conditions were psychiatric disorders and mental retardation. Interrater agreement was high (kappa values of 0.8 to 0.9) for both the patient-oriented and the ILAE classification. Conclusions: Specific epilepsy syndromes included in the current ILAE classification are rare even in a tertiary epilepsy center. Most patients are included in unspecific categories that provide only incomplete information. In contrast, all of the patients could be classified by the five-dimensional patient-oriented classification, providing all essential information for the management of the patients with a high degree of interrater reliability. [source]

Rare living hypopharyngeal foreign body

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 11 2006
Matthias Kuehnemund MD
Abstract Background. This is a case report about a rare hypopharyngeal foreign body causing dysphagia, dyspnea, and hemoptysis as well as melena: an ingested leech. The patient was in this condition for more than 1 week. Methods. The ingested leech, attached to the right piriform fossa partially obstructing the larynx, had to be removed under general anesthesia. Results. After removal, no further symptoms occurred. The leech was identified as the species Theromyzon tessulatum. Conclusions. Human infestation of a leech in the upper aerodigestive tract is a very rare condition in urban areas. The current literature is reviewed and the diagnostic approach as well as therapeutic options are discussed. © 2006 Wiley Periodicals, Inc. Head Neck, 2006 [source]

High Adherence to Antihypertensive Therapy is Rare But When Present Is Associated With a Decreased Risk of Cardiovascular Events

JOURNAL OF CLINICAL HYPERTENSION, Issue 3 2010
Michael J. Bloch MD
No abstract is available for this article. [source]

Febrile Ulceronecrotic Mucha-habermann Disease: a Rare, Severe Variant

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2006
Michele M. Thompson
A 56 year old Hispanic man presented with extensive ulcerative skin lesions, involving his lower trunk, groin and upper legs, severe pain and a temperature of 38.7 degrees Celsius. He was admitted to the Medical Intensive Care Unit for empiric intravenous antibiotics. Several biopsies were performed. In the following days his condition worsened and ulcerative lesions involved nearly all of his skin. Previous biopsies were consistent with pityriasis lichenoides et varioliformis acuta (PLEVA), however, neither this, nor others in the histological differential diagnosis, fit his severe and worsening clinical picture. Histology revealed vacuolar alteration with dyskeratotic keratinocytes and a superficial perivascular mixed infiltrate of lymphocytes and eosinophils. There was confluent parakeratosis containing neutrophils, and a diminished granular layer with pallor in the upper portion of the spinous layer. Immunofluorescence studies were negative. These findings were consistent with PLEVA. A clinical diagnosis of febrile ulceronecrotic Mucha-Habermann disease was made. Febrile ulceronecrotic Mucha-Habermann disease is a rare and severe variant of PLEVA characterised by high fever and papulonecrotic skin lesions. Twenty-five cases have been previously reported. We present the clinical and histological findings in this unusual clinical presentation. [source]

Isolated amyloidosis presenting with lumbosacral radiculoplexopathy: description of two cases and pathogenic review

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 4 2006
Shafeeq S. Ladha
Abstract In this study, we present two cases of infiltrative, localized amyloidosis involving lumbosacral root and plexus, e.g., isolated amyloidomas. Rare and poorly understood amyloidomas may occur in both neurologic and non-neurologic tissues. The described cases emphasize potential for localized peripheral amyloidomas: (1) potential for associated , light chain lymphoplasmacytic lymphoma association; (2) e isolated amyloidosis without evidence for systemic plasma cell dyscrasia; (3) features suggestive of potential pathogenesis; and (4) discussion of treatment options including immunotherapy and resection. The limited literature and experience among other cases is described. [source]

A Rare, Larval-founded Colony of the Bryozoan Archimedes from the Carboniferous of Alabama

PALAEONTOLOGY, Issue 5 2001
Frank K. Mckinney
Very few basal attachments of the spiralled fenestrate bryozoan Archimedes are known. A newly discovered specimen is interpreted to have grown on a thin cylindrical ephemeral substratum that extended above the sediment-water interface, allowing paired spirals to develop and to extend in opposite directions when the colony was very small. [source]

Rare ,-thalassemia mutations are cause of concern

AMERICAN JOURNAL OF HEMATOLOGY, Issue 3 2004
Anju Gupta
No abstract is available for this article. [source]

Double Heterozygosity with Mutations Involving both the GJB2 and GJB6 Genes is a Possible, but very Rare, Cause of Congenital Deafness in the Czech Population

ANNALS OF HUMAN GENETICS, Issue 1 2005
P. Seeman
Summary Mutations in the GJB2 gene are the most common cause of prelingual, autosomal recessive, sensorineural hearing loss worldwide. Nevertheless, 10% to 50% of patients with prelingual nonsyndromic deafness only carry one mutation in the GJB2 gene. Recently a large 342 kb deletion named ,(GJB6-D13S1830) involving the GJB6 gene was reported in Spanish and French deafness patients, either in a homozygous state or in combination with a monoallelic GJB2 mutation. No data have been reported about the frequency of this mutation in central Europe. Thirteen Czech patients with prelingual nonsyndromic sensorineural deafness carrying only one pathogenic mutation in the GJB2 gene were tested for the presence of the ,(GJB6-D13S1830) mutation. One patient with a GJB2 mutation (313del14) also carried the ,(GJB6-D13S1830). This is the first reported Czech case, and probably also the first central European case, of prelingual deafness due to mutations involving both the GJB2 and GJB6 genes. In addition, the ,(GJB6-D13S1830) was not detected in 600 control chromosomes from Czech individuals with normal hearing. We show that in the Czech Republic the ,(GJB6-D13S1830) is not the second most common causal factor in deafness patients heterozygous for a single GJB2 mutation, and that ,(GJB6-D13S1830) is very rare in central Europe compared to reports from Spain, France and Israel. [source]

The relationship between soil seed bank, above-ground vegetation and disturbance intensity on old-field successional permanent plots

APPLIED VEGETATION SCIENCE, Issue 4 2009
Michaela Dölle
Abstract Questions: How does disturbance and successional age influence richness, size and composition of the soil seed bank? What is the potential contribution of the soil seed bank to the plant community composition on sites differing in their successional age or disturbance intensity? Location: Experimental Botanical Garden of Göttingen University, central Germany. Methods: Above-ground vegetation and soil seed bank were studied on formerly arable fields in a 36-year-old permanent plot study with five disturbance intensities, ranging from yearly ploughing via mowing to long-term uninterrupted succession. We compared species compositions, seed densities and functional features of the seed bank and above-ground vegetation by using several methods in parallel. Results: The seed bank was mainly composed of early successional species typical of strongly disturbed habitats. The difference between seed bank composition and above-ground vegetation decreased with increasing disturbance intensity. The species of greatest quantitative importance in the seed bank was the non-native forb Solidago canadensis. Conclusions: The ability of a plant community to regenerate from the soil seed bank dramatically decreases with increasing time since abandonment (successional age) and with decreasing disturbance intensity. The present study underlines that plant species typical of grasslands and woodlands are limited by dispersal capacity, owing to low capacity for accumulation of seeds in the soil and the fact that most species do not build up persistent seed banks. Rare and target species were almost absent from the seed bank and will, after local elimination, depend on reintroduction for continuation of their presence. [source]

Predominant Expression of Mutant EGFR (EGFRvIII) is Rare in Primary Glioblastomas

BRAIN PATHOLOGY, Issue 2 2004
Wojciech Biernat
EGFR amplification is a frequent genetic alteration in primary (de novo) glioblastomas, and is often associated with structural alterations. Most common is variant III (EGFRvIII), which results from a non-random 801 bp in-frame deletion of exons 2 to 7 of the EGFR gene. We assessed amplification and overexpression of EGFRvIII and wild-type EGFR in 30 glioblastoma biopsies. Immunohistochemically, EGFR overexpression was observed in 20 (67%) of 30 glioblastomas. Eight (27%) cases also showed immunoreactivity to an EGFRvIII antibody. In 6 of these cases, the pattern of EGFR and EGFRvIII overexpression was compared in serial sections: In 4 cases, areas with immunoreactivity to EGFRvIII largely coincided with wild-type EGFR expression. In the other 2 cases, the areas immunoreactive to EGFRvIII were significantly less extensive than EGFR-positive areas. To assess whether EGFRvIII is predominantly amplified in tumors with concurrent wild-type EGFR amplification, we carried out real-time quantitative PCR using 2 sets of primers located in exon 2 and intron 15 of the EGFR gene. A>5-fold ratio of relative copy numbers between intron 15 (present both in wild-type EGFR and EGFRvIII) and exon 2 (present only in wild-type EGFR, but missing in EGFRvIII) suggested predominant amplification of EGFRvIII in only 3 (10%) of 30 glioblastomas. The observation that intratumoral wild-type EGFR overexpression is often more extensive and that predominant amplification of EGFRvIII is a rare event would limit the effectiveness of therapeutic approaches based on selective targeting of EGFRvIII. [source]

Multiple endocrine neoplasia type 1

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 4 2003
B. Skogseid
Rare and unpredictable [source]

ChemInform Abstract: Rare [(NHC)2Ni-OH]-Type Terminal Nickel Hydroxo and [(NHC)2Ni]-Type Complexes of N/O-Functionalized N-Heterocyclic Carbenes as Precatalysts for Highly Desirable Base-Free Michael Reactions in Air at Ambient Temperature.

CHEMINFORM, Issue 35 2009
Manoja K. Samantaray
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Management of neuro-ophthalmology cases in children

ACTA OPHTHALMOLOGICA, Issue 2009
S MILAZZO
Neuro-ophthalmological conditions in children must be analyzed carefully and some emergencies must be recognized. Clinical and practical cases are illustrated. On that basis the most important aspects of the field of neuro-ophthalmology are covered succinctly but sufficiently to enable the practitioner to determine an appropriate diagnosis and course of treatment. Rare and unusual diseases are included but those that are especially critical to the patient's vision or general health and life. Some specific clinical signs and symptoms need to be carefully evaluated as papilledema, papillary abnormalities, ptosis, diplopia or ocular motility abnormalities. Each clinical case deals with a symptom that leads the patient to seek medical attention or a sign that is demonstrated on physical examination. The proper diagnosis is frequently made with the imaging but must be repeated if necessary. Specific techniques in children are described including oculomotor and electrical testing, tomodensitometry and magnetic resonance imaging. Different treatment as medical surgical and neurosurgical are discussed. The physician evaluating neuro-ophtalmic patients needs to have a broad background of medical information. So the patient's workup is properly managed and therapeutic orientations can be done. [source]

ChemInform Abstract: Why Are B2O2 Rings Rare?

CHEMINFORM, Issue 6 2001
Jacquelyn M. Burke
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Time-Adaptive Lines for the Interactive Visualization of Unsteady Flow Data Sets

COMPUTER GRAPHICS FORUM, Issue 8 2009
N. Cuntz
I.3.3 [Computer Graphics]: Line and Curve Generation; I.3.1 [Computer Graphics]: Parallel Processing Abstract The quest for the ideal flow visualization reveals two major challenges: interactivity and accuracy. Interactivity stands for explorative capabilities and real-time control. Accuracy is a prerequisite for every professional visualization in order to provide a reliable base for analysis of a data set. Geometric flow visualization has a long tradition and comes in very different flavors. Among these, stream, path and streak lines are known to be very useful for both 2D and 3D flows. Despite their importance in practice, appropriate algorithms suited for contemporary hardware are rare. In particular, the adaptive construction of the different line types is not sufficiently studied. This study provides a profound representation and discussion of stream, path and streak lines. Two algorithms are proposed for efficiently and accurately generating these lines using modern graphics hardware. Each includes a scheme for adaptive time-stepping. The adaptivity for stream and path lines is achieved through a new processing idea we call ,selective transform feedback'. The adaptivity for streak lines combines adaptive time-stepping and a geometric refinement of the curve itself. Our visualization is applied, among others, to a data set representing a simulated typhoon. The storage as a set of 3D textures requires special attention. Both algorithms explicitly support this storage, as well as the use of precomputed adaptivity information. [source]

Recurrent Exacerbations of Protein-losing Enteropathy after Initiation of Growth Hormone Therapy in a Fontan Patient Controlled with Spironolactone

CONGENITAL HEART DISEASE, Issue 2 2010
Michael J. Grattan MSc
ABSTRACT Protein-losing enteropathy (PLE) is a rare, but serious complication in single ventricle patients after Fontan palliation, and is associated with a 5-year mortality of 46%. We describe a patient with PLE after Fontan palliation who achieved remission with high-dose spironolactone (an aldosterone antagonist), but had three exacerbations each temporally correlated with the use of growth hormone (an aldosterone agonist). Because of the opposing mechanisms of action of these two medications, caution might be indicated when using growth hormone for patients with PLE who are successfully treated with spironolactone. [source]

Management of a Fetal Intrapericardial Teratoma: A Case Report and Review of the Literature

CONGENITAL HEART DISEASE, Issue 1 2010
Angela M. Fagiana MD
ABSTRACT Intrapericardial teratomas are rare but potentially fatal. With prenatal ultrasound, early diagnosis and decision for treatment can be accomplished. However, the decision becomes to treat prenatally vs. waiting until the neonatal period for definitive surgical management. The most common sequelae of intrapericardial teratomas are pericardial effusion and often progression to hydrops. It is these sequelae that tend to guide management. Presented here is a case report of the diagnosis and management of a twin fetus with an intrapericardial teratoma, as well as a review of the literature. [source]

Echocardiographic Diagnosis of Right Ventricular Inflow Compression Associated with Pectus Excavatum During Spinal Fusion in Prone Position

CONGENITAL HEART DISEASE, Issue 3 2009
James M. Galas MD
ABSTRACT Introduction., Pectus excavatum is commonly viewed as a benign condition. Associated alterations in hemodynamics are rare. We present an unusual case of right ventricular inflow obstruction and hemodynamic compromise as a consequence of pectus excavatum encountered during surgical intervention. Case., a 15-year-old male with pectus excavatum and thoracolumbar scoliosis developed severe hypotension after induction of general anesthesia and placement in the prone position for elective spinal fusion. A transesophageal echocardiogram revealed anterior compression of the right heart by the sternum with peak and mean right ventricular inflow gradients of 7 and 4 mm Hg, respectively. The gradient resolved with supine positioning and was reproduced with direct compression of the sternum. Conclusions., Although pectus excavatum is generally a benign condition, the cardiologist should be aware of the potential for serious hemodynamic compromise related to positioning in these patients. [source]

Left Coronary Artery Arteriovenous Malformation Presenting as a Diastolic Murmur with Exercise Intolerance in a Child with a Suspected Familial Vascular Malformation Syndrome

CONGENITAL HEART DISEASE, Issue 3 2007
Valerie A. Schroeder MD
Abstract Objective., Intracardiac arteriovenous malformations are rare and may be associated with sudden death in adults. This case report describes an intracardiac left coronary arteriovenous malformation in a 7-year-old boy with a suspected familial cutaneous vascular malformation syndrome. The patient presented with a diastolic murmur, exercise intolerance, chest pain, and a left ventricular mass. Methods., The left ventricular mass was initially identified by echocardiography. Subsequently, a computed tomography scan revealed the vascular nature of the lesion. We hypothesized that the lesion represented either an arteriovenous malformation (AVM) or a hemangioma. These lesions are thought to cause coronary steal and myocardial dysfunction. Skin biopsies of the patient's cutaneous lesions revealed capillary hyperplasia, which was not consistent with either hemangioma or AVM. Thus, a surgical biopsy and partial resection of the mass was performed. Results., The surgical pathology of the cardiac mass was consistent with an AVM. Within 6 months following partial resection of the mass, the patient unexpectedly developed a left ventricular pseudoaneurysm at the resection site and required re-operation. Although a portion of the mass remains, both the patient's chest pain and exercise tolerance have improved subjectively. Conclusion., Patients with cutaneous vascular malformations and diastolic murmurs, as well as cardiac symptoms, should undergo echocardiography or alternative imaging modalities to screen for treatable pathological myocardial vascular malformations. [source]

Neonatal Congestive Heart Failure Due to a Subclavian Artery to Subclavian Vein Fistula Diagnosed by Noninvasive Procedures

CONGENITAL HEART DISEASE, Issue 3 2006
Gregory H. Tatum MD
ABSTRACT Congestive heart failure in the neonate is usually due to intracardiac anomalies or cardiac dysfunction. Extracardiac causes are rare. Patient., We report a newborn infant who presented with respiratory distress and cardiomegaly. Result., Echocardiography identified a dilated right subclavian artery and vein and superior vena cava. Magnetic resonance imaging confirmed a subclavian artery to subclavian vein fistula that was treated with surgical ligation. The infant recovered fully. This case underscores the need for clinical suspicion of fistulous connection in unusual locations in the face of unexplained heart failure in the neonate. Conclusion., Echocardiographic and magnetic resonance imaging are effective noninvasive modalities to confirm the diagnosis prior to surgical intervention. [source]

Retrospective Review: The Incidence of Non-ST Segment Elevation MI in Emergency Department Patients Presenting With Decompensated Heart Failure

CONGESTIVE HEART FAILURE, Issue 6 2003
W. Frank Peacock MD
The authors performed a 6-month review of heart failure patients presenting to a teaching hospital emergency department to determine the rate of positive serum myocardial infarction markers. All patients with an emergency department discharge diagnosis of heart failure were included; those with a creatinine level >2.0 mg/dL were excluded. There were 151 patients who met the entry criteria, with a mean age of 68.6±13.6 years, and 84 (56%) were men. The mean ejection fraction was 32%, and the mean Framingham score was 3.8±1.6. Twenty (14%) had positive markers. Troponin T was positive in 17 (11%), and creatine kinase was positive in nine (6%). Both markers were positive in six (4%). Chest pain was absent in 70% of the positive marker group. The authors conclude that elevated cardiac markers are not rare in decompensated heart failure. These pilot data suggest these tests should be routinely obtained on heart failure patients. [source]