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P Costello

Publications and source records attributed to P Costello.

At least 19 recordsLinked to original sources
PubMed1999

The use of spiral computed tomographic angiography for the assessment of living kidney donors.

BACKGROUND: Recent reports suggest that spiral computed tomographic (CT) angiography can replace conventional angiography and intravenous urography for the assessment of potential kidney donors. The purpose of this study is to assess the accuracy of spiral CT in potential kidney donor workup. METHODS: Over a period of 1 year, from December 1995 to December 1996, 16 consecutive potential renal donors had intravenous pyelography, percutaneous transfemoral angiography with selective renal angiography and spiral CT angiography. The spiral CT and renal angiograms were assessed independently by two radiologists. The number of renal arteries, presence or absence of renal artery stenoses and associated parenchymal abnormalities were assessed. RESULTS: A total of 39 renal arteries were detected. Conventional transverse scans viewed in a cine loop format detected all 39 vessels, while the maximum intensity projection and shaded surface display demonstrated only 37. All 39 vessels were detected by the catheter angiography. With the exception of one potential donor with fibromuscular dysplasia, 15 donors were accepted. There was 100% accuracy between the two methods of visualization for the renal arteries. A simple renal cyst was noted in both spiral CT and conventional angiogram, while another had gallstones in spiral CT. CONCLUSIONS: Spiral CT angiography performed as an outpatient procedure is less invasive, less expensive, and provides good images of the arterial and venous anatomy. It has the potential to replace conventional catheter angiography and intravenous pyelogram in the assessment of potential renal donors.

Angiography↗
PubMed1999

Astrocytoma adhesion to extracellular matrix: functional significance of integrin and focal adhesion kinase expression.

Evidence is accumulating implicating a role for integrins in the pathogenesis of cancer, a disease in which alterations in cellular growth, differentiation, and adhesive characteristics are defining features. In the present report we studied a panel of 8 human astrocytoma cell lines for their expression of integrin subunits by RT-PCR, and of integrin heterodimers by immunoprecipitation analyses. The functionality of integrin heterodimers was assessed using cell attachment assays to plastic or single matrix substrates. Downstream effects of integrin activation were studied by western blot analyses of FAK expression in human astrocytoma cell lines growing on plastic and on a fibronectin matrix, and in 13 primary human brain tumor specimens of varying histopathological grade. Furthermore, we studied tyrosine phosphorylation of FAK in astrocytoma cells growing on plastic versus fibronectin. Finally, we analyzed the effects of intermediate filament gene transfer on FAK phosphorylation in SF-126 astrocytoma cells. Our data show that astrocytoma cell lines express various integrin subunits by RT-PCR, and heterodimers by immunoprecipitation analyses. The beta1 and alphav integrin subunits were expressed by all astrocytoma cell lines. The alpha3 subunit was expressed by all cell lines except SF-188. By immunoprecipitation, the fibronectin receptor (alpha5beta1 integrin heterodimer) and the vitronectin receptor (alphavbeta3) were identified in several cell lines. Astrocytoma cell attachment studies to human matrix proteins suggested that these integrin heterodimers were functional. Using confocal laser microscopy, we showed that FAK was colocalized to actin stress fibers at sites of focal adhesion complexes. By western blot, FAK was variably but quite ubiquitously expressed in human astrocytoma cell lines, and in several primary human astrocytoma specimens. When U373 and U87 MG astrocytoma cells bind to a fibronectin matrix, FAK is phosphorylated. GFAP-transfected SF-126 human astrocytoma cells were shown to overexpress the phosphorylated form of FAK only when these cells were placed on a fibronectin matrix. This result is of interest because it suggests that manipulations of the astrocytoma cytoskeleton per se can bring about potential signaling changes that channel through integrins and focal adhesion sites leading to activation of key kinases such as FAK.

Adult↗
PubMed1998

Noninvasive characterization of plaque morphology using helical computed tomography.

BACKGROUND: Evidence suggests that atherosclerotic plaque composition and morphology are more important predictors of plaque stability and clinical behavior than the degree of vessel stenosis. Unfortunately, noninvasive methods of plaque characterization in situ using duplex ultrasound have been largely unsuccessful. We investigated the accuracy of helical computed tomography (HCT) in defining plaque morphology in patients undergoing carotid endarterectomy. METHODS: Candidates for endarterectomy were enrolled prospectively and underwent HCT with intravenous contrast injection. The attenuation values (in Hounsfield Units) of plaque features such as calcium, fibrous tissue, and lipid were measured and correlated with the tissue types seen on microscopic examination. Percent luminal stenosis derived from transverse HCT images was also compared to values obtained from duplex ultrasound. SETTING: Ambulatory patients referred to a tertiary, metropolitan medical center. RESULTS: A total of 21 out of 22 cases were suitable for comparison. Qualitatively, HCT accurately defined plaque features containing calcium, fibrous stroma, and lipid. Using tissue attenuation values (Hounsfield Units - H), HCT distinguished between lipid and fibrous stroma (means 39+/-12 H and 90+/-24 H, respectively, p<0.001). HCT-derived calculations of percent stenosis also correlated with the ultrasound data (p<0.001). CONCLUSIONS: HCT is an accurate, noninvasive means for studying detailed plaque morphology and composition. This technique provides the basis for further studies correlating plaque anatomy with clinical behavior.

Aged↗
PubMed1996

Neuronal abnormalities in microtubule-associated protein 1B mutant mice.

Microtubules play an important role in establishing cellular architecture. Neuronal microtubules are considered to have a role in dendrite and axon formation. Different portions of the developing and adult brain microtubules are associated with different microtubule-associated proteins (MAPs). The roles of each of the different MAPs are not well understood. One of these proteins, MAP1B, is expressed in different portions of the brain and has been postulated to have a role in neuronal plasticity and brain development. To ascertain the role of MAP1B, we generated mice which carry an insertion in the gene by gene-targeting methods. Mice which are homozygous for the modification die during embryogenesis. The heterozygotes exhibit a spectrum of phenotypes including slower growth rates, lack of visual acuity in one or both eyes, and motor system abnormalities. Histochemical analysis of the severely affected mice revealed that their Purkinje cell dendritic processes are abnormal, do not react with MAP1B antibodies, and show reduced staining with MAP1A antibodies. Similar histological and immunochemical changes were observed in the olfactory bulb, hippocampus, and retina, providing a basis for the observed phenotypes.

Animals↗
PubMed1996

Comparison of primer sets for detection of fecal and ocular adenovirus infection using the polymerase chain reaction.

Adenoviruses of subgenus F (types 40 and 41) cause infantile gastroenteritis and adenoviruses principally of types 1-7 are found in feces during respiratory or generalized infections. Adenoviruses (mostly types 3, 4, 8, 19, or 37) are also linked with follicular or epidemic conjunctivitis. The diagnostic efficiency of the polymerase chain reaction (PCR) for adenoviruses was assessed using genus-reactive primers H1 and H2 or JCH1 and JCH2 or subgenus F-specific primers F1a and F2a. With diarrheal stool specimens containing subgenus F adenoviruses, F1a/F2a PCR achieved at least as high a positivity rate (75/76 [99%]) as electron microscopy (72/76 [95%]) and was more sensitive than polyclonal antibody-based immune electron microscopy (IEM) for subgenus identification (75/76 [99%] vs. 66/76 [87%], P = 0.008). Twenty-three subgenus F strains untypeable by monoclonal antibody-based IEM were typed as 40 (n = 4) or 41 (n = 19) by Hha I digestion of the PCR product. The genus-reactive primer pairs provided DNA amplification assays of generally equal efficiency on conjunctival swab specimens though possible nucleic acid degradation in DNA extracts during storage could have meant that JCH1/JCH2 PCR was truly the more sensitive. The use of either genus-reactive primer set on fecal specimens cannot be recommended because, although the positivity rates with subgenus F PCR positive specimens were high (70/75 [93%] for H1 and H2, 14/15 [93%] for JCH1 and JCH2), the detection rates were disappointing with similar specimens yielding nonsubgenus F adenoviruses.

Adenoviridae Infections↗
PubMed1996

Spiral CT with multiplanar and three-dimensional reconstructions accurately predicts tracheobronchial pathology.

BACKGROUND: This study was designed to evaluate the clinical accuracy of multiplanar reconstructions and three-dimensional shaded surface displays compared with conventional transaxial computed tomography, bronchoscopy, and surgical pathologic findings. METHODS: Transaxial computed tomographic images, two-dimensional nonstandard multiplanar reconstruction images, and three-dimensional images obtained from patients with tracheobronchial disease were prospectively evaluated for the relationship to adjacent structures, lesion characterization, and surgical anatomic correlation before invasive procedures. RESULTS: Compared with conventional transaxial computed tomographic images, multiplanar reconstructions and three-dimensional shaded surface displays provided a correlative map of bronchoscopic and surgical anatomy in patients with benign and malignant tracheobronchial pathology. The longitudinal extent of abnormalities are better demonstrated on the multiplanar reconstruction and three-dimensional images, whereas the transverse extent of disease and relationships to adjacent structures were better shown on axial computed tomographic sections. CONCLUSIONS: Three-dimensional and multiplanar two-dimensional images are additive to transaxial computed tomography for evaluation of diseases involving the central airways. They are beneficial for planning invasive procedures. More importantly, they provide consistent, highly accurate measurements for routine follow-up and for future clinical trials.

Aged↗
PubMed1996

Spiral CT with multiplanar and three-dimensional reconstructions accurately predicts tracheobronchial pathology.

BACKGROUND: This study was designed to evaluate the clinical accuracy of multiplanar reconstructions and three-dimensional shaded surface displays compared with conventional transaxial computed tomography, bronchoscopy, and surgical pathologic findings. METHODS: Transaxial computed tomographic images, two-dimensional nonstandard multiplanar reconstruction images, and three-dimensional images obtained from patients with tracheobronchial disease were prospectively evaluated for the relationship to adjacent structures, lesion characterization, and surgical anatomic correlation before invasive procedures. RESULTS: Compared with conventional transaxial computed tomographic images, multiplanar reconstructions and three-dimensional shaded surface displays provided a correlative map of bronchoscopic and surgical anatomy in patients with benign and malignant tracheobronchial pathology. The longitudinal extent of abnormalities are better demonstrated on the multiplanar reconstruction and three-dimensional images, whereas the transverse extent of disease and relationships to adjacent structures were better shown on axial computed tomographic sections. CONCLUSIONS: Three-dimensional and multiplanar two-dimensional images are additive to transaxial computed tomography for evaluation of diseases involving the central airways. They are beneficial for planning invasive procedures. More importantly, they provide consistent, highly accurate measurements for routine follow-up and for future clinical trials.

Adolescent↗
PubMed1995

Prognostic significance of microvessel density in lymph node negative breast carcinoma.

We evaluated the prognostic value of tumor angiogenesis in node negative breast cancer (NNBC). Paraffin-embedded tissues from 87 patients with NNBC were immunostained for factor VIII-related antigen, using one tissue block representative of the invasive edge of the tumor. Sections were scanned at low power to identify "hotspots" of angiogenesis. Microvessel (MV) counts were performed at x200 magnification, using a grid eyepiece graticule. Within each hot spot, three fields (area of field = 0.22 mm2) were counted and averaged. The highest average for a hot spot and the highest single field value was recorded for each case. Patients were stratified into low and high MV groups and their survival compared. There were no differences in disease-free or overall survival between the two groups whether the highest average or the highest single value was used. Microvessel counts did not correlate with other prognostic features, ie, grade, size, estrogen receptor status, c-erb B-2 or accumulated P53 status. Because of the difficulty in assessing angiogenesis that is heterogenous throughout tumors, MV counting may not be suitable for clinical use as a prognostic factor in NNBC. This problem could be addressed in a prospective study involving more extensive tumor sampling.

Adult↗
PubMed1995

Spiral CT angiography of abdominal aortic aneurysms.

Spiral computed tomographic (CT) angiography involves a timed intravenous injection of contrast material, rapid data acquisition, reconstruction at narrow intervals, image editing, and maximum intensity projection image processing. Spiral CT angiography of the abdominal aorta was performed in 28 patients for preoperative aneurysm assessment. The results were unsatisfactory in only two patients; 54 main and 12 accessory renal arteries and 26 aortic aneurysms were seen. In 17 of the 26 patients with aneurysms, there was surgical confirmation of the CT angiographic findings regarding size, suprarenal extension, and distal extent of the aneurysms, with no additional renal arteries detected. With this technique, the relationship of an aneurysm to renal, superior mesenteric, and inferior mesenteric arteries can be assessed. CT angiography also depicts the proximal extent of an aneurysm, which is the single most crucial piece of preoperative information; an associated renal artery stenosis or occlusion; or an accessory renal artery. CT angiography can be performed as an outpatient procedure before vascular surgery with fewer risks, with lower radiation dose, and at one-third the cost of conventional angiography.

Aged↗
PubMed1995

Use of continuous human lung cell culture for adenovirus isolation.

Adenovirus sensitivity, TCD50 value and mean time to cytopathic effect (CPE) were compared in Madin-Darby canine kidney (MDCK), rhesus monkey kidney (RhMK), human lung carcinoma (A549) and in newly identified continuous human lung (CHL) cell cultures. High-titer stock and positive original specimens were inoculated in culture. Patients specimens were also placed in shell-vial cultures. A549 and CHL cells demonstrated comparable sensitivity, however the former generally produced CPE earlier. Sensitivity was respectively reduced and poor in RhMK and MDCK cultures, as expected in cells of nonhuman origin. The performance of CHL for adenoviruses and other pathogens makes them a useful addition in diagnostic virology laboratories.

Adenoviruses, Human↗
PubMed1995

CT angiography.

CT angiography is an exciting yet controversial application of helical (spiral) CT technology. Although many radiologists equate CT angiography with three-dimensional (3D) rendering, we believe that axial images, multiplanar reformatted (MPR) images, and true 3D models all contribute to a better evaluation of the vascular system than was possible with conventional CT. This occurs because helical scans are volumetric and are accomplished rapidly with high levels of circulating contrast material. This article reviews the indications for CT angiography, compares CT angiography with other techniques, and offers a practical methodology for neuroradiologic, thoracic, and abdominal applications of CT angiography.

Angiography↗
PubMed1995

Helical (spiral) CT of the thorax.

Helical CT should be used routinely for thoracic imaging both as a primary screening tool in patients assessed for metastatic disease or lung cancer and as a problem solving modality in more complex lesions (e.g., arteriovenous malformations). Greater confidence in diagnosis and improved accuracy of lesion detection are benefits resulting from the volumetric data acquisition of helical CT. Optimal use of intravenous contrast material during a short scan interval enhances the diagnosis of pulmonary thromboembolic disease and aortic pathology. The airways can be displayed in detail on axial, coronal, or minimum intensity projection images, which is useful when planning interventional or surgical procedures.

Adult↗
PubMed1995

In vivo three-dimensional evaluation of the tracheobronchial tree.

Traditionally computed axial tomography has had limitations in evaluating diseases that affect the tracheobronchial tree because of respiratory-induced artifacts, with the likelihood of missing lesions as a result of misregistration. Spiral computed tomography (CT) differs from conventional CT in that the entire thorax can be rapidly imaged in the axial plane after a single breath-hold. Five patients underwent non-contrast-enhanced volumetric CT, with emphasis on three-dimensional reconstruction, and endoscopic evaluation with pathologic confirmation. In all cases, there was complete corroboration between volumetric CT and endoscopic evaluation. The use of selective thresholds allowed the air within the tracheobronchial tree to be used as a negative contrast agent. Thus with the integration of selective windowing, detailed three-dimensional tracheobronchial anatomy may be elucidated. The absence of respiratory registration artifact due to the single breath-hold technique raises the confidence that three-dimensional and multiplanar images generated from such studies are accurate representations of the pathologic conditions at hand. By the integration of volumetric CT techniques and rapid three-dimensional display of tracheobronchial structures, volumetric CT bronchography becomes practical.

Aged↗
PubMed1994

Spiral CT of the thorax.

Spiral CT represents a major advance in CT technology. While the patient is advanced through the scanner gantry, continuous data acquisition occurs during suspended respiration eliminating many of the limitations associated with conventional thoracic CT. By eliminating respiratory misregistration and by offering the ability to reconstruct overlapping images at small intervals, spiral CT is advantageous for pulmonary nodule detection. Airway pathology and lesions adjacent to the diaphragm are better visualized with spiral CT and can be displayed in multiplanar or three-dimensional formats. Vascular imaging, including pulmonary embolus detection, is improved by spiral CT because scanning occurs rapidly at the peak of vascular enhancement.

Adult↗
PubMed1994

Comparison of rapid detection methods for influenza A virus and their value in health-care management of institutionalized geriatric patients.

Respiratory specimens from 160 geriatric patients with suspected influenza illness were used to evaluate the abilities of two enzyme immunoassays (EIAs; Directigen FLU-A [Becton Dickinson Microbiology Systems, Cockeysville, Md.] and Prima EIA [Baxter/Bartels Diagnostics, Inc., Issaquah, Wash.]) and direct immunofluorescence testing (immunofluorescence assay [IFA]) to identify influenza A virus. In comparison with culture isolation, the sensitivities and specificities of the IFA, Directigen FLU-A, and Prima EIA were 92.5 and 97.2%, 86.8 and 99.1%, and 92.5 and 98.1%, respectively. In contrast to EIA, IFA was labor intensive and required a high degree of technical expertise, and the results of IFA were difficult to interpret. These factors may preclude the use of IFA for testing large numbers of specimens. A retrospective epidemiologic survey of influenza infection was done in six geriatric institutions which had used either rapid and culture testing or culture alone. Preventable cases of influenza A virus infection ranged from 9 to 38% of all cases in facilities which used culture testing only and which had not instituted amantadine prophylaxis. The use of direct specimen testing is recommended as an adjunct to culture isolation for the identification of influenza A virus. Use of a combination of these methods permits the timely administration of appropriate antiviral therapy and infection control measures, while it also permits the antigenic surveillance of circulating influenza strains, which is necessary for present vaccine efficacy evaluations and the creation of future effective vaccine formulations.

Aged↗
PubMed1994

Thoracic helical CT.

Helical CT depicts small pulmonary nodules not seen at conventional CT by elimination of respiratory misregistration and thorough analysis of a contiguous data volume. Pulmonary lesions can be analyzed in detail with use of retrospective reconstruction of the data volume. Multiplanar and three-dimensional images of lung masses and arteriovenous malformations are free of motion artifacts. The airways are clearly depicted by helical CT, a capability that enhances the radiologic evaluation of patients with hemoptysis, bronchial strictures, tumors, and recent lung transplantation. In comparison to conventional CT, helical CT provides a more consistent level of vascular enhancement because of the shortened acquisition time. Clinical applications include the detection of central pulmonary thromboemboli and the assessment of aortic aneurysms and dissections.

Angiography↗
PubMed1994

Cost-effective use of low-osmolality contrast media for CT of the liver: evaluation of liver enhancement provided by various doses of iohexol.

OBJECTIVE: Because of pending efforts to reform health care in the United States, judicious use of low-osmolality contrast media is important. We studied the effects of using various concentrations and volumes of iohexol, compared with the conventional dose and concentration of diatrizoate meglumine used for CT, to determine if a more cost-effective dose results in diagnostically efficacious liver enhancement. SUBJECTS AND METHODS: A total of 902 patients received one of nine different doses of IV contrast media. Eight doses of iohexol were used: 125 ml of iohexol 350 (350 mg l/ml, 44 g l/dose), 100 ml of iohexol 350 (35 g l/dose), 150 ml of iohexol 300 (300 mg l/ml, 45 g l/dose), 120 ml of iohexol 300 (36 g l/dose), 100 ml of iohexol 300 (30 g l/dose), 175 ml of iohexol 240 (240 mg l/ml, 42 g l/dose), 150 ml of iohexol 240 (36 g l/dose), and 125 ml of iohexol 240 (30 g l/dose). A single dose (150 ml) of diatrizoate meglumine 60% (w/v) was used (42 g l/dose). Contrast material was injected at a rate of 2 ml/sec. Scanning began 35-45 sec after injection. Quantitative analysis of enhancement was performed by obtaining region-of-interest measurements through the liver on scans obtained before and after injection of contrast material. Mean and maximum changes in hepatic density and mean time to maximum enhancement were measured. Mean time-density curves were subsequently derived for each dose of contrast material. Qualitative analysis of enhancement was performed by using subjective, previously defined criteria. All studies were interpreted in a double-blind fashion. RESULTS: Mean hepatic enhancement was greater with 125 ml of iohexol 350 and 150 ml of iohexol 300 than with other doses of contrast material (p < .05). Both 125 ml of iohexol 350 and 150 ml of iohexol 300 produced actual hepatic enhancement of more than 50 H for over 60 sec. The greatest maximum increase in hepatic density occurred with 125 ml of iohexol 350. When analyzed qualitatively, 150 ml of iohexol 300 resulted in the highest percentage of optimum enhancement. CONCLUSION: According to quantitative analysis, 125 ml of iohexol 350 administered at a rate of 2 ml/sec produces the best enhancement, whereas according to qualitative analysis, 150 ml of iohexol 300 produces the best enhancement. All doses of iohexol 240 provide poor enhancement compared with a conventional dose of contrast material of 150 ml of diatrizoate meglumine 60% or 150 ml of iohexol 300. A moderate cost savings can be achieved by using 125 ml of iohexol 350 for dynamic sequential CT.

Cost-Benefit Analysis↗