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At least 883 records · Page 49Linked to original sources
PubMed2005

Aortoiliac and lower extremity arteries assessed with 16-detector row CT angiography: prospective comparison with digital subtraction angiography.

PURPOSE: To prospectively compare the accuracy of 16-detector row computed tomographic (CT) angiography with conventional digital subtraction angiography (DSA) as the reference standard in the assessment of aortoiliac and lower extremity arteries in patients with peripheral arterial disease. MATERIALS AND METHODS: This study was approved by the institutional review board, and informed consent was obtained. A total of 39 consecutive patients (27 men [mean age, 66 years] and 12 women [mean age, 64 years]) with peripheral arterial disease underwent both conventional DSA and 16-detector row CT angiography. For data analysis, the arterial vascular system was divided into 35 segments. A total of 1365 arterial segments were analyzed for arterial stenosis by two independent blinded readers using a four-point grading system (grade 1, <10% luminal narrowing; grade 2, 10%-49% luminal narrowing; grade 3, 50%-99% luminal narrowing; grade 4, occlusion). Interobserver agreements were calculated by using kappa statistics. A third independent blinded reader assessed possible reasons for disagreements between 16-detector row CT angiographic findings and conventional DSA findings. Effective radiation dose was calculated for both imaging modalities. RESULTS: Sixteen-detector row CT angiographic and conventional DSA findings were diagnostic in all vascular segments. Compared with conventional DSA, the sensitivity and specificity of 16-detector row CT angiography with regard to detection of hemodynamically significant stenosis in all 35 arterial segments were 96% and 97%, respectively, for both readers. Readers 1 and 2 overestimated arterial stenosis in 42 (3%) and 34 (2%) arterial segments, respectively, and underestimated arterial stenosis in 13 (1%) and 10 (1%) arterial segments, respectively. Interobserver agreement was excellent (kappa = 0.84-1.00). Presence of anteroposteriorly located luminal narrowing and extensive vascular wall calcification were considered main reasons for disagreements between imaging modalities. Effective radiation dose was lower for 16-detector row CT angiography (1.6-3.9 mSv) than for conventional DSA (6.4-16.0 mSv). CONCLUSION: Sixteen-detector row CT angiography is an accurate and reliable noninvasive alternative to conventional DSA in the assessment of aortoiliac and lower extremity arteries in patients with peripheral arterial disease.

Adult↗
PubMed1995

Clinical application of single dual-energy subtraction technique with digital storage-phosphor radiography.

We used a single-exposure dual-energy subtraction technique with a storage-phosphor computed radiography (CR) system to evaluate various pulmonary diseases. Clinical applications of this method have been studies at our institution. In our experience, the dual-energy subtraction technique provided better visualization of pulmonary nodules, tracheobronchial abnormalities, pulmonary vascular diseases, calcification in a nodule, and rib lesions than conventional CR images did. Single-exposure dual-energy subtraction images were obtained with a sandwich technique using two storage-phosphor imaging plates with a 1-mm-thick copper filter interleaved between the two. The front plate obtains a lower kilovoltage image, whereas the back plate obtains a higher kilovoltage image. We can visualize soft tissue and bone images as well as unsubtracted digital images by the subtraction process.

Bronchial Diseases↗
PubMed2003

Cartilaginous metaplasia and calcification in aortic allograft is associated with transforming growth factor beta 1 expression.

BACKGROUND: Calcification of homografts and vascular conduits is poorly understood. Mechanisms leading to calcification were studied in a rat model of aortic allografts. METHODS: Rat aortas from Lew1W (RT1(u)) were transplanted into Lew1A (RT1(a)). Animals were killed at 30 days and 180 days, and aortic grafts were removed and analyzed for histologic and immunohistologic studies. RESULTS: Intimal surface increased progressively over 6 months and was the site of important modifications. Intimal cellular population changed from a leukocyte (CD45, OX1-OX30)- and macrophage (CD68, ED-1)-based population at 30 days to predominantly alpha-smooth muscle actin-expressing cells at 180 days. At 180 days, allografts were characterized by an abundant extracellular matrix composed of collagen and elastic fibers associated with extensive calcification (von Kossa staining) located in the intima and media. Osteoblastic activity was present in calcified lesion as shown by alkaline phosphatase activity. At 180 days, numerous chondrocytes (protein S100-positive and alpha-smooth muscle actin-negative) were present focally in the media. However, double immunostaining revealed that a cellular population within the media with a chondrocyte-like morphology was alpha-smooth muscle actin-positive and S100-negative. Active form of transforming growth factor beta1 was expressed from 30 to 80 days in the medial and intimal layers. CONCLUSIONS: These observations suggest that alpha-smooth muscle actin-positive cells within aortic allografts are eventually transformed to a chondrocyte-like structure, leading to vascular cartilaginous metaplasia associated with the expression of transforming growth factor beta1 and could be a potential pathway leading to extensive vascular wall calcification in allografts through endochondral ossification.

Animals↗
PubMed1977

Synovial calcification in a patient with collagen-vascular disease: light and electron microscopic studies.

Unusual articular as well as periarticular calcifications are reported in a patient with collagen-vascular disease. Tiny crystals visible in electron micrographs in synovial membrane and in synovial fluid cell vacuoles resemble apatite and appear most consistent with apatite on electron probe studies. The inflammatory synovial effusion also contained chylomicrons. Other joint diseases associated with synovial calcification or suspected synovial apatite are discussed.

Adult↗
PubMed2001

Abdominal aortic calcific deposits are an important predictor of vascular morbidity and mortality.

BACKGROUND: The impact of abdominal arterial calcific deposits on the prediction of cardiovascular disease (CVD) over a long follow-up interval deserves greater scrutiny. METHODS AND RESULTS: Lateral lumbar radiographs were studied as a predictor of incident coronary heart disease (CHD), CVD, and CVD mortality in 1049 men and 1466 women (mean age, 61 years) who were followed from 1967 to 1989. Anterior and posterior wall calcific deposits in the aorta at the level of the first through fourth lumbar vertebrae were graded according to increasing severity using a previously validated rating scale for abdominal aortic calcium (AAC) that ranges from 0 to 24 points. There were 454 cases of CHD, 709 cases of CVD, and 365 CVD deaths. Proportional hazards logistic regression was used to test for associations between AAC and later events after adjustment for age, cigarette use, diabetes mellitus, systolic blood pressure, left ventricular hypertrophy, body mass index, cholesterol, and HDL cholesterol. In comparisons with the lowest AAC tertile, the multivariate age-adjusted relative risks (RR) for CVD were increased in tertile 2 (men: RR, 1.33; 95% confidence interval [CI], 1.02 to 1.74; women: RR, 1.25; 95% CI, 0.95 to 1.65) and tertile 3 (men: RR, 1.68; 95% CI, 1.25 to 2.27; women: RR, 1.78; 95% CI, 1.33 to 2.38). Similar results were obtained with CHD and CVD mortality. CONCLUSIONS: AAC deposits, detected by lateral lumbar radiograms, are a marker of subclinical atherosclerotic disease and an independent predictor of subsequent vascular morbidity and mortality.

Aorta, Abdominal↗
PubMed1993

Chicken tibial dyschondroplasia: a limb mutant with two growth plates and possible defects of collagen crosslinking.

In the cartilaginous epiphyseal growth plate, extracellular matrix molecules such as collagens are believed to play important roles during both normal and abnormal development. One defect of the epiphyseal plate occurs in chickens with a condition termed tibial dyschondroplasia (TD). This abnormality occurs in certain strains of juvenile chickens and other rapidly developing animals. It is characterized by the presence of a mass of avascular, uncalcified cartilage which is retained in the proximal metaphysis of the tibiotarsus. To elucidate the developmental events which may be involved in this lesion, we have performed both immunohistochemistry and in situ hybridizations for collagen types II and X, known components of the extracellular matrix of the growth plate. By immunohistochemical analyses, the TD lesion contains both of these collagen types; therefore, the presence of these molecules per se is not sufficient for calcification of vascularization to occur. Since type X collagen is expressed exclusively in hypertrophic cartilage, the chondrocytes in the lesion must have undergone hypertrophy before their developmental arrest. The matrix of the lesion also reacted with a monoclonal antibody which is directed against an epitope in the NH2-terminal telopeptide of the alpha 1(II) chain. Our previous data suggest that this epitope is rendered unavailable in type II collagen which has undergone crosslink formation; its availability in the lesion suggests that crosslinking may be abnormal. Lastly, analyses by in situ hybridization failed to detect mRNA for either type II or type X collagen within the lesion, but chondrocytes distal to the lesion do contain mRNAs for these collagens in a spatial pattern suggesting the presence of a second growth plate.

Animals↗
PubMed1984

Opsismodysplasia: a new type of chondrodysplasia with predominant involvement of the bones of the hand and the vertebrae.

The name opsismodysplasia is proposed for a new chondrodysplasia, which was studied in three patients. Clinically, the condition is recognized at birth on the basis of shortness, short hands, and facial abnormalities with a short nose and a depressed bridge of nose. The most characteristic radiographic signs are: very retarded bone maturation; marked shortness of the bones of the hands and of the feet with concave metaphyses; and thin, lamellar vertebral bodies. The growth cartilage studied in one case showed a wide hypertrophic area containing thick connective tissue septa, irregular provisional calcification, and vascular invasion. Type I collagen was detected in the hypertrophic area by immunohistochemical and microchemical tests. The transmission of opsismodysplasia is probably autosomal recessive.

Abnormalities, Multiple↗
PubMed1988

Lectin-binding histochemistry of intracellular and extracellular glycoconjugates of the reserve cell zone of growth plate cartilage.

The distribution of intracellular and extracellular lectin-binding glycoconjugates of the reserve cell zone of growth plate cartilage was studied in the distal radial growth plate of 4-week-old Yucatan swine using a postembedment method on Epon-embedded sections. Direct comparisons were made to articular, tracheal, and auricular cartilages not involved in endochondral ossification. All patterns of lectin binding that in the growth plate were restricted to the reserve cell zone were also patterns characteristic of tracheal, articular, and auricular cartilages. These included: (a) pericellular binding with peanut agglutinin (PNA) without prior digestion with neuraminidase; (b) pericellular binding with wheat germ agglutinin (WGA) at 24 h; (c) intracellular cytoplasmic binding to concanavalin A (CON-A), Lens culinaris agglutinin (LCA), and Lotus tetragonobolus agglutinin (LTA) after periodic acid oxidation; and (d) a lack of pericellular binding with CON-A and ricin agglutinin 1 (RCA-1) after periodic acid oxidation. We conclude that reserve zone chondrocytes lack specific phenotypic markers as defined by lectin-binding affinity that are found in the cellular zones of the growth plate that undergo calcification and vascularization. The reserve zone has identical lectin-binding affinities to the three structural cartilages used as controls. One interpretation of these results is that the reserve zone may not be involved directly in endochondral ossification, but may have a structural function in growth plate cartilage.

Animals↗
PubMed1985

Primary cranial and intracranial chondrosarcoma. A survey.

Fifty cases of intracranial and cranial chondrosarcoma were reviewed in the world literature including two of our own. These were analyzed relevant to their histological subgroup, site of origin, age and sex incidence, calcification and vascularity, recurrence, and metastases. The analysis was done in order to clarify points in the diagnosis, management, and prognosis of this rare tumour. The mesenchymal subtype is a more malignant form with a higher tendency for recurrence, metastasis, and increased vascularity.

Adult↗
PubMed1999

The thymus in Langerhans' cell histiocytosis.

OBJECTIVE: To determine the frequency of thymic involvement in Langerhans' cell histiocytosis and describe its imaging appearance before and after treatment. MATERIALS AND METHODS: A retrospective review of the radiology and clinical records of all patients diagnosed with Langerhans' cell histiocytosis at DeVos Children's Hospital between 1992 and 1998. RESULTS: Of the 14 patients diagnosed with Langerhans' cell histiocytosis, 7 demonstrated multisystem involvement. The thymus was involved in 5 of 7 patients. The thymus was enlarged in 5; thymic contours were nodular/lobulated in 2; cystic changes were noted in 4; and dystrophic vascular-appearing calcifications were seen in 1. In all cases, findings regressed or resolved following chemotherapy. CONCLUSION: The thymus is commonly involved in Langerhans' cell histiocytosis, especially in multisystem disease. Radiologically, the thymus is enlarged and may be smooth or lobulated/nodular in contour, possibly containing cysts and calcifications.

Adolescent↗
PubMed1993

Enhanced detection of cardiac allograft arterial disease with intracoronary ultrasonographic imaging.

Intracoronary ultrasonographic imaging was performed in 60 patients 0.3 to 9 years (mean 2.9 +/- 1.9) after heart transplantation. By using a 1.8 mm intravascular ultrasonographic catheter, 192 (80%) of 240 angiographically visualized major epicardial coronary arteries (right, left main, anterior descending, and circumflex) were imaged by ultrasonography. Coronary luminal irregularities were detected in 15% of arteries by angiography compared with 34% by ultrasonography (p < 0.0001). The typical abnormality detected by ultrasonography consisted of crescentic and/or concentric intimal and medial thickening. Calcification in vascular lesions was rare (< 1% of arteries studied). Although the prevalence of angiographic abnormalities tended to be time dependent, ultrasonographic abnormalities were more strongly associated with donor age (normal, 22 +/- 8 years, vs abnormal, 33 +/- 10 years; p < 0.0001). Cardiac allograft coronary arterial disease is significantly underestimated by contrast angiography. Intravascular ultrasonography may provide a useful adjunct for identification and serial follow-up of this significant problem.

Adult↗
PubMed1985

The effect of pulsating electromagnetic fields on condylar growth in guinea pigs.

The purpose of this study was to determine if a simple, noninvasive method could be developed for the application of pulsed electromagnetic fields that would lend itself to future clinical applications. Specifically, the modulation and control of condylar cellular metabolism and the stimulation of cellular proliferation were attempted in order to increase the amount of mandibular condylar growth. A pulsed electromagnetic field with a frequency of 100 hertz was applied for 8 hours per day to the mandibular condylar area of rapidly growing, male, Hartley guinea pigs. Ten guinea pigs were exposed for 10 days and a second group of 10 guinea pigs was exposed for 30 days. In addition, 5 guinea pigs were used as controls for each experimental period. During the experimental period the guinea pigs were placed in specially constructed, plastic animal holders with their heads positioned in an area of uniform magnetic field. After 10 days of pulsed electromagnetic field exposure, there were increases in vascularity, secretion of cartilagenous intercellular matrix, and woven-bone formation in the guinea pig condyle. After 30 days, there were continued but attenuated vascular and calcification responses with an increase noted in marrow hemopoietic elements. An increase in the number of osteoclasts was also noted after 10 days. This effect was transient and was not present at the end of the 30-day experimental period. The application of the pulsed electromagnetic field did not result in a significant increase in the overall anteroposterior or vertical size of the guinea pig mandible compared to controls. The results of this study suggest that it is possible to affect condylar cartilagenous and bony metabolism through the application of a noninvasive, pulsed electromagnetic field.

Animals↗
PubMed1995

Time course of oxysterol formation during in vitro oxidation of low density lipoprotein.

Cholesterol oxidation products (oxysterols) have been implicated in several aspects of atherogenesis; they affect key enzymes in cholesterol homeostasis, induce calcification in vascular cells and possess cytotoxic properties. Oxysterols are formed during oxidative modification of low density lipoprotein (LDL). Using a recently developed method based on isotope dilution-mass spectrometry, the kinetics of formation of oxysterols during oxidation of LDL by cupric ions or soybean lipoxygenase was studied. The same products, mainly 7- and 5-oxygenated cholesterol, were formed by the two oxidation methods. Virtually no side-chain oxidized oxysterols were formed. During the oxidations, preferentially esterified cholesterol was consumed and consumption of polyunsaturated fatty acids and formation of conjugated dienes preceded the appearance of oxysterols. Cholesterol 7-hydroperoxides potential cytotoxins, were present in LDL oxidized by copper or lipoxygenase.

Cholesterol↗
PubMed2006

Disruption of the vascular prosthesis caused by aortic calcification after replacement of the thoracoabdominal aortic aneurysm.

A 52-year-old man underwent a replacement of the thoracoabdominal aorta. The aorta was severely calcified, and was replaced by a 24-mm woven Dacron (Vascutek, Renfrewshire, Scotland) graft wrapped with the calcificated aneurysmal wall. His postoperative course was uneventful; however, he collapsed on the 18th postoperative day. He underwent an emergent thoracotomy and the wrapped aneurysmal wall was taken down. The prosthesis graft had a 1-mm disruption in the middle portion, which did not relate to the anastomoses. Experimental study ex vivo showed that disruption of the prosthesis could have occurred after a 3-week pulsatile force caused by a seashell simulating aortic calcification.

Animals↗
PubMed1988

Cardiovascular pathology and extracorporeal shock wave lithotripsy.

We investigated the impact of extracorporeal shock wave lithotripsy on cardiac pacemakers, arterial calcifications, and vascular clips. When 22 cardiac pacemaker pulse generators mounted five cm. lateral to the focus of the lithotripter were subjected to both synchronous and asynchronous shock waves, one reverted to magnet rate with synchronous shocks and 11 were inhibited by asynchronous shocks. None was damaged or spuriously reprogrammed. In a second experiment, 10 canine and cadaveric aortas and common iliac arteries with metal surgical clips on two to three mm. branches were pressurized with methylene blue in normal saline at 150 mm. Hg and fixed in the Dornier lithotripter. Shock waves (N = 2000; 22 kV) were focused on the surgical clips and no leakage of methylene blue was found.

Aged↗
PubMed1996

Panniculitis: recent developments and observations.

Dermatopathologists rarely greet a biopsy of panniculitis with total confidence that a specific, definitive diagnosis will be rendered. As with many other areas in dermatopathology, our understanding of the pathogenesis of many forms of panniculitis is incomplete. This article examines a subset of panniculitis primarily from a pathogenetic standpoint, with the intention of providing a differential diagnosis for those cases in which ischemic changes are seen in the subcutis. The diverse group of conditions evoked by this approach also shares the distinction of having been the focus of nosologic and causative controversy, both historically and currently. In particular, stasis-associated sclerosing panniculitis, vascular calcification-cutaneous necrosis syndrome (calciphylaxis), oxalosis, and nodular vasculitis-erythema induratum are examined in depth. Erythema nodosum and variants, other granulomatous panniculitides, and panniculitides showing cytophagocytosis are also discussed with current perspectives.

Diagnosis, Differential↗
PubMed2006

Peripheral arterial occlusive disease is more prevalent in patients with hemodialysis: comparison with the findings of multidetector-row computed tomography.

BACKGROUND: Peripheral arterial occlusive disease (PAOD) influences the mortality of patients on hemodialysis therapy. Although the ankle-brachial pressure index (ABI) is used widely to detect PAOD, it yields false-negative results because of calcifications of vascular walls. To more accurately assess the prevalence of PAOD, we investigated which noninvasive method, among ABI, toe-brachial pressure index, transcutaneous Po(2), and skin perfusion pressure (SPP), had superior sensitivity and specificity to the others. METHODS: Multidetector-row computed tomography was performed in 36 hemodialysis patients. We then compared the 4 noninvasive methods with findings of multidetector-row computed tomography and calculated the sensitivity and specificity of each method by means of receiver operating characteristic analysis. Irrespective of symptoms, PAOD is defined as the presence of complete obstruction in the case of lesions below the knee or more than 75% stenosis for lesions above the knee. RESULTS: Seven of 36 patients (19.4%) had an ABI less than 0.9. Sensitivity of the ABI was only 29.9%, whereas an SPP set at 50 mm Hg was more accurate, with sensitivity of 84.9% and specificity of 76.9%. A total of 41.4% of patients had an SPP less than 50 mm Hg. For lesions located above the knee, toe-brachial pressure index provided sensitivity of 91.7% and specificity of 86.7%. CONCLUSION: SPP is the most useful tool for detecting PAOD in hemodialysis patients, with accuracy of 84.9%. There is a strong possibility that more patients than previously expected have early PAOD.

Adult↗
PubMedDate not supplied

[Blue rubber bleb nevus syndrome with CNS involvement].

We report a child with Blue Rubber Bleb Nevus Syndrome (BRBNS) and marked CNS-involvement and complex neurological impairment. Computed tomography showed intracerebral calcification and vascular malformations. The patient is microcephalic, his psychomotor development is delayed and he has a deficit of motor coordination and visual function. We know of only one report of a child with BRBNS and such CNS involvement.

Brain Neoplasms↗