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S Noma

Publications and source records attributed to S Noma.

At least 19 recordsLinked to original sources
PubMed1992

Pulmonary scintigraphy in elastase-induced emphysema in pigs. Correlation with high-resolution computed tomography and histology.

OBJECTIVES: The objective of this study is to evaluate the mild physiologic changes of elastase-induced pulmonary emphysema in the pig by radionuclide scintigraphy and to correlate these findings with high-resolution computed tomography (HRCT) and histologic examination. METHODS: Eight 7- to 12-week-old Yorkshire pigs were studied. Perfusion and ventilation studies were performed in six pigs at 1- or 2-week intervals after elastase instillation. HRCT was simultaneously performed for correlation with radionuclide scintigraphy. For the perfusion scans, technetium 99m (99mTc) macroaggregated albumin (MAA) was used, and both planar and single-photon emission CT (SPECT) images were obtained. Ventilation studies were performed with xenon-133 gas with dynamic sequential imaging. RESULTS: Histopathologic findings demonstrated dilatation and destruction of the alveoli and were similar to those previously reported by the authors. The SPECT perfusion images showed significantly impaired perfusion of the involved segment of the lung, corresponding to the region where elastase was instilled. The planar xenon-133 ventilation scintigraphy did not show abnormal air trapping. The mild emphysema induced with elastase manifested as decreased and impaired perfusion with no detectable ventilation abnormalities. The sensitivity of SPECT perfusion studies for the detection of the mild changes of elastase-induced pulmonary emphysema were higher than that of HRCT. CONCLUSIONS: The perfusion studies reflect functional or physiologic changes in contrast to structural changes seen on HRCT. This pig model was valuable to study the scintigraphic manifestation of elastase-induced pulmonary emphysema.

Animals↗
PubMed1992

Experimental pulmonary infarction in a pig model.

RATIONALE AND OBJECTIVES: The authors sought to develop a reliable animal model for experimental pulmonary infarction, to evaluate it with radiologic-pathologic correlation, and to determine the use of high-resolution computed tomography (HRCT) in monitoring parenchymal lung damage due to infarction. METHODS: Selective left lower lobe pulmonary artery occlusion was performed in seven Yorkshire pigs with transcatheter silicone elastomer injection. After occlusion, 99m technetium (99mTc) macroaggregated albumin perfusion lung scans and sequential in vivo HRCT lung scans were obtained from days 0 to 46. The in vivo radiologic findings were correlated with specimen radiography, specimen HRCT, and histologic findings. RESULTS: A complete and permanent arterial occlusion was achieved, involving up to three orders of branching distal to the catheter. An anatomically defined perfusion defect was seen on 99mTc lung scans corresponding to the occluded area. HRCT changes consisted of confluent densities progressing to mixed alveolar and interstitial opacities within the first week after embolization. In the follow-up period, marked parenchymal clearing was observed. In all cases after pulmonary artery occlusion, the histologic findings were characteristic of pulmonary infarction and demonstrated alveolar edema, hemorrhage, limited alveolar wall damage, and septal thickening followed by residual fibrosis. CONCLUSION: Using this model, it is feasible to produce pulmonary infarction in the pig which may potentially be useful to study the pathophysiologic and radiologic changes of pulmonary infarction.

Animals↗
PubMed1992

Preservation of myocardial function during ischemia with intracoronary perfluoroocytlbromide (Oxygent).

UNLABELLED: The effects of intracoronary infusion (24 ml/min) of oxygenated perfluoroocytlbromide (PFOB) or autologous blood on regional myocardial function and hemodynamics were studied during a 2 min perfused occlusion in nine open chest dogs to determine if a PFOB infusion could prevent the myocardial dysfunction observed during the balloon occlusion of percutaneous transluminal coronary angioplasty (PTCA). Regional myocardial function was measured with sonomicrometers in the ischemic and non-ischemic zone to determine segment length and percent of systolic shortening (% delta L). Without infusion, the ischemic zone in each animal developed akinesis during a 20 sec coronary occlusion. Each animal underwent a 2 min infusion of blood and PFOB at 24 ml/min. During the 2 min perfused occlusion, the blood ischemic zone % delta L of 14.4 +/- 3.1 versus a PFOB % delta L of 23.4 +/- 2.9. % delta L of blood and PFOB were not as significantly different from control (P less than .05 PFOB vs. blood). The bromine ion in PFOB results in a radiodense compound. Adequate images of the canine left ventricle and coronaries were obtained using DSA. CONCLUSION: (1) PFOB infusion maintains normal myocardial function during perfused coronary inclusion. (2) PFOB may be used as an oxygen carrying contrast agent to obtain DSA images.

Angioplasty, Balloon, Coronary↗
PubMed1991

Sequential morphologic changes of elastase-induced pulmonary emphysema in pig lungs. Evaluation by high-resolution computed tomography.

The authors evaluated the early morphologic changes of elastase-induced pulmonary emphysema in the pig and correlated the findings with high-resolution computed tomography (HRCT). Nine Yorkshire pigs were included in this investigation; in seven, pulmonary emphysema was induced by 2 mg/kg body weight of elastase instilled selectively into the left lower lobe bronchus. Animals were studied by CT at 0, 1, 2, 3, 7, 14, and 21 days. At the completion of the experiment, the lungs were removed, inflated, fixed and dried, and subsequently sliced corresponding to the CT sections. The gross appearance, histologic appearance, and HRCT were correlated. On HRCT, sequential changes from early edema to development of emphysema were noted. Panlobular, centrilobular and paraseptal emphysema were observed. Elastase-induced pulmonary emphysema in the pig is a useful and reproducible animal model, and high-resolution computed tomography depicts the morphologic changes observed both by gross pathologic observations and histologic observations.

Animals↗
PubMed1990

Gallbladder carcinoma: evaluation with MR imaging.

Magnetic resonance (MR) images of 19 patients with histologically proved gallbladder carcinoma were retrospectively reviewed to determine the appearance of the primary tumor, and to assess the ability of MR imaging to demonstrate the various modes of tumor spread beyond the gallbladder. The primary tumor, as well as tumor spread beyond the gallbladder, was hyperintense on T2-weighted images and hypointense on T1-weighted images when compared with the liver parenchyma. Liver invasion and metastasis could be depicted by MR imaging with both sequences, unless the tumors were small or the extent of invasion was minimal. Duodenal invasion was difficult to evaluate because of motion artifacts, paucity of fat, and partial volume effects. T1-weighted images readily demonstrated extension of the tumor to the hepatoduodenal ligament and para-aortic region with good contrast between tumor and surrounding tissue. The extent of tumor extension to the blood vessels was also easily evaluated because of flow void in the vasculature. MR imaging can help determine the extent of gallbladder carcinoma and can contribute to the staging of this disease.

Adenocarcinoma↗
PubMed1990

Detection of serum antibody by the antimitogen assay against streptococcal erythrogenic toxins. Age distribution in children and the relation to Kawasaki disease.

We describe a new method to measure human serum antibody against streptococcal erythrogenic toxins that uses inhibition of lymphocyte mitogenicity of the toxins as the indicator. Sera from 53% of 53 Kawasaki disease patients contained specific inhibitory activity against A toxin, whereas only 15% had serum inhibitory activity against B toxin. The specific anti-A toxin serum inhibitor was found in 10% of 118 age-matched control patients suffering from various infections and allergic diseases (p = 0.001, compared to Kawasaki disease patients). Serum inhibitory activity was detected in a small number of patients with beta-hemolytic streptococcal infection (3/19) and in none of the age-matched healthy children (0/17). However, four of seven cord blood sera samples and five of 13 sera samples from healthy neonates contained the inhibitor, a result suggesting passive transfer from mothers. Most of the antimitogen-positive sera were also positive by ELISA of IgG antibody against A toxin, and IgG fractions of the positive sera remained positive in both assays. Thus, it is possible that the specific serum inhibitor detected by the antimitogen assay represents anti-A toxin antibody. The role of toxin-producing bacteria in the pathogenesis of Kawasaki disease remains to be investigated.

Antibodies, Bacterial↗
PubMed1990

Pharmacokinetics in chimpanzees of recombinant human tissue-type plasminogen activator produced in mouse C127 and Chinese hamster ovary cells.

Pharmacokinetics of recombinant tissue-type plasminogen activator (rt-PA) produced in mouse C127 cells (t-PA(C127] and Chinese hamster ovary cells (t-PA(CHO] was investigated in chimpanzees. rt-PA was administered via a constant rate i.v. infusion for 60 min, and t-PA concentration and activity in plasma were measured during and after infusion. The noncompartmental parameters were calculated according to the moment analysis method, and a population pharmacokinetic analysis was performed to obtain the mean and interindividual variability of the pharmacokinetic parameters. The mean residence time of t-PA(C127) was significantly longer and the total body clearance was significantly less than that of t-PA(CHO). t-PA(C127) has an alpha-galactosyl moiety in its carbohydrate chains, whereas such a structure is not found in t-PA(CHO). These results demonstrate that two preparations of rt-PA's with different carbohydrate structures show different pharmacokinetics, and suggest that the carbohydrate structure can affect the efficiency of hepatic uptake of t-PA. A possible mechanism is an interaction of t-PA(C127) with the natural anti-alpha-galactosyl antibody. The anti-alpha-galactosyl antibody level in plasma decreased in association with the plasma levels of t-PA(C127) but was unaffected by t-PA(CHO) levels.

Animals↗
PubMed1990

Specificity of human natural antibody to recombinant tissue-type plasminogen activator (t-PA) expressed in mouse C127 cells.

A natural antibody with binding specificity for recombinant tissue-type plasminogen activator (t-PA) expressed in mouse C127 cells was present in almost all disease-free humans and patients with thrombotic disease examined. This antibody was specific for a carbohydrate, alpha 1-3-linked galactose residue, and was isolated by affinity chromatography using Synsorb 90 coupled with the glycosidic epitope Gal alpha 1-3Gal beta 1-4Glc-R as an immunoadsorbent. The evaluation of various glycoproteins for ability to bind the purified antibody in ELISA demonstrated that not only recombinant t-PA from C127 cells but also recombinant erythropoietin (EPO) and recombinant protein C produced in C127 cells have alpha 1-3-linked galactose residues on their sugar side chains. This anti-alpha-galactosyl antibody also interacted with natural t-PA from human vascular trees (vascular t-PA) and placenta (placenta t-PA), but not to melanoma t-PA, recombinant t-PA, EPO or protein C expressed in Chinese hamster ovary (CHO) cells.

Animals↗
PubMed1989

Effect of postextrasystolic potentiation on systolic bulging of ischemic myocardium.

Because the extent of myocardial bulging after acute coronary occlusion is primarily dependent on wall tension, this study examined whether the decrease in systolic bulging with postextrasystolic potentiation was due to contractile reserve or to changes in loading conditions. Seven dogs were atrially paced at 100 beats/min after the sinus node was crushed and atrial extrasystoles were generated. The left ventricular minor axis diameter and segment lengths in the ischemic and nonischemic zones were measured with sonomicrometers. Wall tension was estimated using Laplace's law, and regional tension-length loops were determined. By 5 min after the left anterior descending coronary artery was occluded, there was regional bulging. Postextrasystolic potentiation diminished the extent of bulging by increasing both isovolumic and ejection percent systolic shortening (isovolumic -9.1 +/- 2.0% to -5.9 +/- 1.7%, p less than 0.008; ejection 2.2 +/- 0.7% to 4.3 +/- 2.0%, p less than 0.008). The tension-length loops after coronary occlusion showed an exponential upstroke and almost superimposed downstroke consistent with passive movement. The loops were unchanged by postextrasystolic potentiation. Wall tension data showed that bulging was reduced because of a shift down the tension-length curve as end-systolic wall tension was reduced by augmented nonischemic contraction. Similar results were seen at 60 min of coronary occlusion. This study demonstrates that the decrease in bulging seen with postextrasystolic potentiation is due to changes in loading conditions and not to contractile reserve.

Animals↗
PubMed1989

Carcinoma of the cervix: staging with MR imaging.

Demonstration and staging of carcinoma of the cervix with magnetic resonance (MR) imaging was evaluated prospectively in 67 patients with histologically proven lesions. Findings were correlated with surgical/pathologic results obtained within 2 weeks. MR imaging had an accuracy of 95% in demonstrating invasive disease (stage IB or higher). It was capable of depicting the location and extent of tumor invasion of cervical stroma and helped detect tumor beneath relatively normal epithelium or within the endocervical canal that had not been detected by means of colposcopic biopsy. The overall accuracy of MR imaging in staging carcinoma of the cervix was 76%, and in demonstrating parametrial status, the overall accuracy was 89%. In 39 patients with proven invasive disease, the accuracy in demonstrating parametrial status was 82%. In 13 of these 39 patients the low-signal-intensity stromal ring of the cervix on MR images was completely preserved and there were no false-positive results. MR imaging is a highly promising method for directly demonstrating and staging carcinoma of the cervix and seems to be capable of providing answers to crucial questions regarding mode of therapy.

Adult↗
PubMed1989

Enlarged uterus: differentiation between adenomyosis and leiomyoma with MR imaging.

The potential of magnetic resonance (MR) imaging in differentiation of adenomyosis from leiomyoma was evaluated in 93 patients who had a palpable enlarged uterus that was suspect for leiomyoma or adenomyosis. In all cases, MR images were correlated with surgical/pathologic findings. Pathologic findings showed that 71 enlarged uteri were due to leiomyoma, including one leiomyosarcoma, and 16 were due to adenomyosis. The other six patients were shown to have an enlarged uterus attributable to simultaneous involvement of both lesions. On T2-weighted images, adenomyosis appeared as an ill-defined, relatively homogeneous low-signal-intensity area embedded with sparse high-intensity spots. In contrast, leiomyomas were well-circumscribed masses with a spectrum of signal intensity. The cause of uterine enlargement was correctly diagnosed with MR images in 92 of the 93 cases. It is concluded that MR imaging is highly accurate in helping to distinguish between adenomyosis and leiomyoma in cases of enlarged uterus.

Adult↗
PubMed1989

Gamna-Gandy bodies of the spleen: evaluation with MR imaging.

The authors retrospectively evaluated magnetic resonance (MR) images obtained in 64 patients with portal hypertension. Multiple low-intensity nodules were noted within the spleen in eight patients. In all eight cases, these nodules were most apparent on images obtained with the GRASS (gradient-recalled acquisition in the steady state) technique, which is known to be more sensitive to heterogeneity of the magnetic susceptibility, usually caused by hemosiderin deposition. In one of these cases, ultrasonography demonstrated diffuse hyperechoic spots that had been reported to represent Gamna-Gandy bodies of the spleen (ie, organized hemorrhage caused by portal hypertension). Although there was no pathologic proof in their series, the authors believe these low-intensity nodules seen on MR images may represent the hemosiderin deposits of Gamna-Gandy bodies.

Adult↗
PubMed1989

[Magnetic resonance imaging of the thorax].

We examined thirty-five patients with various chest diseases with cardiac gated Magnetic Resonance Imaging (MRI) at 1.5 tesla. Major advantages of MRI of the thorax are its abilities to display sagittal and coronal planes and to disclose vessels clearly without contrast media. We conclude MRI is useful in evaluating, 1) masses at the lung apex or base, 2) chest wall invasion, 3) hilar and mediastinal lymphadenopathy, 4) aortic aneurysm, and 5) bronchogenic cyst.

Adult↗
PubMed1988

The effect of ionic contrast medium on the movement of acutely ischemic and nonischemic canine myocardium.

Regional function assessed by ventriculography may be influenced by the hemodynamic effects of rapidly injecting ionic contrast medium. The importance of this after acute coronary occlusion was examined in eight open-chest, anesthetized dogs. The left anterior descending artery was ligated while sonomicrometric segment lengths in the ischemic (IZ) and nonischemic zones (NZ) were measured. Sodium methylglucamine diatrizoate (Renografin-76, 1 ml/kg) was rapidly injected over 3 seconds. Fifteen minutes later, the left ventricular end-diastolic pressure (LVEDP) was rapidly increased to the level reached during injection. Injecting the contrast increased the LVEDP (7.3 +/- 2.5 to 20.1 +/- 2.9 mm Hg, p less than 0.0001) to the same extent as raising LVEDP (7.6 +/- 2.5 to 10.1 +/- 2.9 mm Hg, p less than 0.0001). Injecting the contrast medium increased IZ total percent systolic shortening (% delta L) (-3.90 +/- 4.43% to -2.68 +/- 4.77%, p less than 0.001) by decreasing isovolumic bulging (-6.68 +/- 4.09% to -5.49 +/- 3.33%, p less than 0.001) with little change in ejection % delta L. NZ total % delta L tended to increase (19.03 +/- 6.53% to 19.94 +/- 6.27%, p = 0.015) because of augmented ejection % delta L (13.12 +/- 2.51% to 13.71 +/- 3.10%, p = 0.017) by the Starling mechanism. Increasing the LVEDP had the same effect on IZ and NZ regional shortening as injecting contrast. Thus regional shortening after acute coronary occlusion is affected by the changes in loading conditions with ionic contrast ventriculography.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Adenomyosis: diagnosis with MR imaging.

Magnetic resonance (MR) imaging characteristics of adenomyosis were studied in eight women (aged 37-49 years) who underwent hysterectomy, and detailed radiologic/pathologic correlation was conducted in all cases. Adenomyosis produced diffuse and smooth uterine enlargement. The extent of the lesion was clearly identified on images obtained with long repetition time and long echo time; a diffuse, low-intensity area accompanied by tiny high-intensity spots was seen subjacent to the endometrium. The area appeared as a localized or diffuse thickening of the junctional zone because it was often isointense with this zone. Pathologic examination confirmed that the extent of adenomyosis correlated well with the low-intensity region on MR images and that both hemorrhagic areas and nonbleeding endometrial tissue corresponded to the high-intensity spots. The lesion consisted of distorted and compacted smooth muscle cells, but microscopic studies failed to explain the definitive difference in intensity between areas of adenomyosis and myometrium.

Adult↗
PubMed1988

Thyroid masses: MR imaging and pathologic correlation.

The authors explored the capability of high-field-strength surface coil magnetic resonance (MR) imaging in disclosing the gross pathologic characteristics of thyroid masses (especially pseudocapsular and hemorrhagic degeneration). Twenty-four patients were examined, including 12 with papillary carcinoma, eight with adenoma, and four with adenomatous goiter. All patients underwent surgery within 2 days after MR imaging. Specimens were cut and correlated directly with MR images. The appearance of the pseudocapsule was classified into four types: A, intact and even thickness around the tumor; B, only partially present or even absent; C, intact but with uneven thickness; D, partially destroyed by tumor. MR imaging findings corresponded precisely with those of gross pathologic examination in all cases but four of adenoma. Type A pseudocapsules were found only in adenoma and type D only in papillary carcinoma. Although the number of cases in the series was limited, the authors conclude that MR images reflect gross pathologic findings well and that some characteristic findings are suggestive of benign or malignant disease.

Adenoma↗
PubMed1988

Spinal arteriovenous malformation: MR imaging.

Ten patients with spinal arteriovenous malformations (AVMs) were examined with high-field-strength (1.5-T) magnetic resonance (MR) imaging and a surface coil (eight patients) or head coil (two patients). Four AVMs were intramedullary, and six were extramedullary. There was one case of Foix-Alajouanine disease (subacute necrotizing myelitis; thrombosed AVM). Three important pathologic findings--myelomalacia, total thrombosis, and wall thickening of the draining vein--were clearly demonstrated at MR imaging and confirmed at autopsy. A flow-sensitive sequence was valuable in the depiction of one intramedullary AVM as hyperintense, the postoperative evaluation of AVM, and the differentiation of nidus from old intramedullary hematoma. In other AVMs, cord edema, periradicular hematoma, and reversible changes of cord scalloping after surgery were demonstrated. MR imaging demonstrated various pathologic changes of the spinal cord that could not be detected with any other imaging method.

Adult↗