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Biomedical subjects

T Kamano

Publications and source records attributed to T Kamano.

At least 37 records · Page 2Linked to original sources
PubMed1997

Histopathologic study of islets of Langerhans in patients after gastrectomy.

In autopsy specimens removed after gastrectomy from patients who had survived for 2.5 to 40 years after surgery, we found hyalinization of the islets of Langerhans in 9 of 15 cases (60%) with Billroth's I anastomosis (B-I) and in 8 of 16 cases (50%) with Billroth's II anastomosis (B-II). The hyalinization in the postgastrectomy patients was significantly increased compared with that in controls (p < 0.01). The percentage of hyalinized islets of Langerhans in the 17 cases showing hyalinization ranged from 0.2% to 14.3%. The percentage increased relative to the period after gastrectomy in the B-I patients but not in those with B-II. The blood glucose level was mildly elevated in three B-I patients, whereas it was increased in only one patient with B-II. Hyalinization of the islets of Langerhans may be due to vagotomy or to excessive stimulus and hyperactivation of the islets. In any event, the islets of Langerhans in patients after gastrectomy were frequently replaced by hyalinization, which might cause impaired glucose tolerance.

Aged↗
PubMed1997

[A case of gastric malignant lymphoma with perforation during chemotherapy].

A 54-year-old male was admitted for loss of appetite lasting for about 3 months. The patient was diagnosed as malignant lymphoma in the stomach invading directly the pancreas, spleen and transverse colon. Chemotherapy, two cycles of VEPA.M, was selected as the initial treatment. After the first cycle of chemotherapy, the patient was discharged temporarily. During the second cycle, on an ambulant basis, the patient suddenly complained of severe pain and distension in the abdomen. Through the X-ray examination of the chest, free air was demonstrated in the bilateral subphrenic spaces. The patient was diagnosed as perforation of the gastrointestinal tract. Subsequently, total gastrectomy was performed. Pathological examination revealed no malignant cells in the stomach wall. It is suggested that the perforation was caused by weakening of the stomach wall following chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Mutagenic activation of N-nitrosobis(2-oxopropyl)amine by pancreatic juice and assessment of its ductal tumorigenicity following intraductal administration in dogs.

CONCLUSION: The results suggest that systemic administration (s.c. and i.p.) of BOP induces liver damage due to BOP itself and/or its metabolites which might be formed in the liver and that interaction of BOP itself in the pancreatic duct with pancreatic juice plays an important role for pancreatic duct tumorigenicity. METHODS: Mutagenic activation and pancreatic duct tumorigenicity of N-nitrosobis (2-oxopropyl)amine (BOP) administered s.c., i.p., and i.d. were studied in dogs. RESULTS: Following i.p. administration of BOP, N-nitroso(2-hydroxypropyl) (2-oxopropyl)amine (HPOP) and N-nitrosobis(2-hydroxypropyl)amine (BHP), but not BOP, were detected in pancreatic juice, while following i.d. administration, only BOP was detected. The pancreatic juice of one dog that received 100 mg of BOP i.d. showed positive mutagenicity towards Salmonella typhimurium TA100, but the pancreatic juice of two dogs that received 100 mg of BOP i.p. was not mutagenic. BOP showed clear mutagenicity in the presence of pancreatic juice from untreated dogs, but the pancreatic juice could not activate HPOP and BHP to mutagens. BOP administered sc for 2 wk (total dose: 600 mg) induced clinical toxicity, nausea, vomiting, and loss of appetite at 10 wk. BOP administered i.p. for 4 mo (total dose: 2000 mg) induced liver damage at 6 mo, but no pancreatic injury. BOP administered i.d. for 6.5 or 12 mo (total dose: 2500 or 4700 mg, respectively) induced papillary hyperplasia and dysplasia of duct epithelial cells and ductal proliferation with fibrosis.

Animals↗
PubMed1996

Characterization of a novel hemagglutinin of diarrhea-associated Escherichia coli that has characteristics of diffusely adhering E. coli and enteroaggregative E. coli.

Escherichia coli 73-1 (serotype O73:H33) and 5-2 (serotype O89:H-) isolated from patients with diarrhea adhered to tissue culture cells (HeLa and HEp-2) as well as coverslips (plastic and glass) in a diffuse pattern. Adherence of strain 73-1 was mediated by a 110-kbp plasmid designated pEDA1 and correlated with D-mannose-resistant hemagglutinin (MRHA) detected with bovine, sheep, or human erythrocytes. The MRHA region was duplicated on pEDA1 and mediated the production of the 57-kDa outer membrane protein whose N-terminal amino acid sequence was hydrophobic. In accordance with MRHA and adherence, the 57-kDa outer membrane protein was observed best at 37 degrees C and to a lesser extent at 25 degrees C. In human intestine, adherence to mucus and colonic epithelium was obvious. No detectable pili were observed. The enteroaggregative E. coli heat-stable enterotoxin 1 (EAST1) gene, whose nucleotide sequence was 99.1% homologous to that of enteroaggregative E. coli, was present adjacent to the MRHA region on pEDA1. Strain 5-2 also exhibited MRHA activities and adherence and had sequences corresponding to those of the MRHA region and EAST1 gene. The data suggest that strain 73-1 (and strain 5-2), which has characteristics of both diffusely adhering E. coli and enteroaggregative E. coli, possesses a novel hemagglutinin associated with diffuse adherence.

Amino Acid Sequence↗
PubMed1994

[Measurement of cerebral blood flow in normal subjects by phase contrast MR imaging].

Global cerebral blood flow (CBF) was quantitatively measured with a two-dimensional phase contrast cine magnetic resonance (MR) imaging technique in 24 normal subjects (mean age, 38.6 years; range, 12-70 years). Cine transverse images of the upper cervical region (32 phases/cardiac cycle) were acquired with a 1.5 Tesla MR imaging unit. In five subjects, measurement of CBF was performed before and after intravenous administration of acetazolamide (DIAMOX, 15 mg/kg). Inter- and intraobserver variations in flow volume measurement were small (r = 0.970, standard error of the estimate (SEE) = 2.9 ml/min, n = 80; r = 0.963, SEE = 4.6 ml/min, n = 40, respectively). In measuring flow velocity, they were inferior to those of flow volume measurement. On a visually determined setting of region of interest (ROI), reproducibly of the measurement of flow velocity was not satisfactory in this study. Thus only the results of flow volume measurement are presented. Mean summed vertebral flow volume (171 ml/min, SD = 40.6) was significantly less than mean summed internal carotid flow volume (523 ml/min, SD = 111). Total blood flow volume showed a significant decline with age (r = 0.45, p < 0.05). The mean proportions of carotid and vertebral flow volume to total flow volume were 75.3% and 24.7%, respectively, and showed no significant change with age. The left-to-right ratio of vertebral flow volume (1.39) was significantly higher than that of internal carotid flow volume (0.99, r = 0.05). After DIAMOX i.v., the mean rate of increase in total flow volume was 157%. Mean rates of increase in carotid and vertebral flow volume were 154% and 166%, respectively, which were not significantly different. In conclusion, this method is useful for estimating carotid and vertebral flow volume.

Acetazolamide↗
PubMed1994

Impaired hepatic function in segmental biliary obstruction demonstrated with a receptor-binding radiotracer.

A patient with cholangiocarcinoma underwent left-sided cholangiojejunostomy, and hepatic functional imaging with a receptor-binding radiotracer and SPECT was performed to evaluate the distribution of functional reserve. It revealed decreased accumulation in the regions with residual dilatation of the intrahepatic bile ducts, indicating several kinds of focal damage in hepatic function caused by segmental biliary obstruction. The radioligand may be useful in assessing regional hepatic function, and the high spatial resolution provided by SPECT appears to play an important role for this purpose.

Aged↗
PubMed1994

Abnormal sympathetic innervation of the heart in a patient with myotonic dystrophy detected with I-123 MIBG cardiac SPECT.

Iodine-123 MIBG is a norepinephrine analog which can be used to image the sympathetic innervation of the heart. The authors report a patient with myotonic dystrophy whose I-123 MIBG SPECT revealed accelerated washout of I-123 MIBG from infero-posterior and a part of lateral wall, although Tl-201 SPECT showed no abnormal finding. The authors conclude that I-123 MIBG can be more sensitive in detecting the cardiac abnormality than Tl-201 SPECT in this disease.

3-Iodobenzylguanidine↗
PubMed1993

[MR imaging of pituitary dwarfism].

Pituitary MR imaging was performed in 32 patients with clinically diagnosed pituitary dwarfism and 12 normal controls. The patients were divided into two groups according to the severity of pituitary dwarfism based on endocrinological data. The two patients with severe dwarfism showed transection of the pituitary stalk, ectopic posterior lobe and atrophy of the anterior lobe on MR imaging, while the 27 patients with mild dwarfism showed no abnormal MR findings of the pituitary gland. The former group corresponds to typical pituitary dwarfism and the latter to partial GH deficiency, which was recently proposed as another type of pituitary dwarfism. In conclusion, pituitary MR imaging may differentiate partial GH deficiency from typical (stalk-transected) pituitary dwarfism.

Adolescent↗
PubMed1993

Aortic regurgitation: quantitation with MR imaging velocity mapping.

Aortic regurgitation (AR) in five healthy volunteers and 26 patients (mean age, 60.3 years; range, 25-83 years) was quantitatively measured with magnetic resonance (MR) imaging velocity mapping. Cine transverse images of the ascending aorta (32 phases per cardiac cycle) were acquired by using a gradient-echo sequence with a velocity-encoding bipolar pulse applied in the section-selection direction with a 1.5-T MR imaging unit. The aortic flow was calculated by integrating the product of area and mean velocity of the ascending aorta at each phase over a cardiac cycle. The negative and positive velocity values indicated antegrade and regurgitant flow, respectively, which allowed calculation of forward and regurgitant flow. Inter- and intraobserver variation of regurgitant fraction (RF) measurement was small (r = .956, standard error of the estimate [SEE] = 1.2%, n = 31; and r = .998, SEE = 0.35%, n = 10, respectively). RF determined with MR imaging agreed well with Doppler echocardiographic (n = 26) and aortographic (n = 9) grading of AR. Reproducible, quantitative, and noninvasive measurement of AR is possible with MR velocity mapping.

Adult↗
PubMed1993

[Dual-energy data acquisition for simultaneous 81mKr ventilation/99mTc-MAA perfusion SPECT: ventilation/perfusion ratio mapping in cross section].

Methods of simultaneous pulmonary ventilation/perfusion (V/Q) tomogram (SPECT) for V/Q ratio mapping were reported. Crosstalk was corrected by subtraction assuming crosstalk/signal ratio is constant for an individual examination. Crosstalk was reduced by 85% for that of 99mTc-to-81mKr window (R12), and by 83% for that of 81mKr-to-99mTc window (R21) in a phantom experiment. The R12 and R21 were 1.0-1.9% (mean 1.3%) and 34.6-55.3% (mean 41.9%), respectively in 9 patients (mean age, 56.1 years; range, 38-82 years). V/Q SPECT was undertaken in 7 of the 9 patients. 99mTc-macroaggregated albumin (185 MBq) was injected intravenously in supine position, and 81mKr gas was administered continuously during the SPECT data acquisition. Sixty-four 64 x 64-matrix (size = 8 mm/pixel) images, 20-second acquisition time for each, were collected by a rotating gamma camera in a step-and-shoot fashion during a 360-degree rotation with the two photopeaks, one at 140 keV for 99mTc and another at 190 keV for 81mKr. Examination time was about 40 minutes, and the V/Q ratio maps in cross section were obtained in all of the examinations.

Adult↗
PubMed1993

[Radionuclide studies of atherosclerosis].

New Tc-99m-labeled brain perfusion imaging agents, such as Tc-99m-HMPAO, and Tc-99m-ECD, are developed and expected to improve the clinical study of cerebral perfusion disturbance due to arteriosclerosis. They enable us better images than I-123-IMP and more accurate diagnosis. Similarly, in the field of cardiovascular nuclear medicine, new Tc-99m-labeled compounds, Tc-99m-MIBI, Teboroxime and Tetrofosmin are available. Furthermore, I-123-MIBG, a tracer taken up in presynaptic adrenergic vesicles, and I-123-BMIPP, a new agent developed for the evaluation myocardial fatty acid metabolism, will mark a new epoch in the study of coronary sclerosis. In order to image atherosclerosis directly, In-111-polyclonal immunoglobulin G, Tc-99m-low density lipoprotein etc., are under investigation.

Amphetamines↗
PubMed1993

[Comparison between 180 degrees and 360 degrees data collection in 99mTc-Tetrofosmin SPECT of the myocardium].

We compared 360 degrees data collection technique with 180 degrees technique in SPECT using a new myocardial perfusion imaging agent, 99mTc-Tetrofosmin. Eight patients were examined at stress and at rest on separate days. Following the injection of 555 MBq 99mTc-Tetrofosmin, 64 views of 15 sec each were collected during a 360 degrees rotation, and 32 views of 30 sec each during a 180 degrees rotation. The 180 degrees data collection provided superior images in sharpness in 14 of 16 scans. The interpretation was concordant in 123 of 128 regions (96.1%), and hypoperfusion was considered to be underestimated in 5 regions using the 360 degrees technique. It was suggested that the 180 degrees data collection technique is more effective in myocardial SPECT employing 99mTc-Tetrofosmin than the 360 degrees technique.

Aged↗
PubMed1993

[Clearance of 99mTc-Tetrofosmin from the myocardium and the adjacent organs].

We studied clearance of a new myocardial perfusion imaging agent, 99mTc-Tetrofosmin, from the myocardium and the adjacent organs in nine patients. 99mTc-Tetrofosmin was injected intravenously at stress and at rest, and SPECT images were obtained 25 min and 120 min later. Anterior view images were also obtained 10 min and 150 min after the injection to compare the myocardial clearance with those from the liver and lung. Clearance from the liver was faster than those from the myocardium and lung. Washout rate calculated with SPECT was higher for the inferior wall than for the anterior wall and lateral wall (p < 0.05 at rest, N.S. at stress). The value was higher at stress in any region than at rest (the anterior wall and lateral wall, p < 0.01; the septum, p < 0.05; the inferior wall, N.S.). Washout rate for the anterior wall was 3.4 +/- 14.0% at rest and 18.0 +/- 10.6% at stress. The rate for the lateral wall was 2.7 +/- 22.5% at rest and 15.8 +/- 7.9% at stress. It was suggested that rapid hepatic clearance and high myocardial washout at stress may be important in determining the period between the injection of 99mTc-Tetrofosmin and the data acquisition for SPECT imaging.

Female↗
PubMed1992

[Two-dimensional time-of-flight MR angiography of mediastinum and pulmonary hilar vessels: initial clinical experiences].

Two-dimensional time-of-flight magnetic resonance angiography (2D TOF MRA) of mediastinal and pulmonary hilar vessels was performed in 10 patients, seven men and three women with a mean age (range) of 65.7 (48-88) years. The rate of visualization of the vessels and the diagnostic ability of 2D TOF MRA were assessed in comparison with contrast-enhanced CT. A radiofrequency-spoiled gradient echo sequence (SPGR) was used during repeated breath-holding (8-27 seconds) in coronal (8 patients) and axial (2 patients) imaging planes on a 1.5 Tesla superconducting scanner under the following conditions: repetition time/echo time/flip angle/excitation: 25-33/7-8 ms/45 degrees/1, field-of-view: 30 x 30 cm, slice thickness: 2.5 mm, 32 slices, 256 (frequency) x 192 (phase) matrix, with gradient moment nulling technique. Visualization sufficient to enable diagnosis of the vascular lesion was obtained in 95 (52%) vessels, mere visualization in 63 (35%), and non-visualization in 24 (13%) of the 182 evaluable vessels. The rates of good visualization of pulmonary hilar vessels (26/86, 30%) and veins (26/48, 54%) were significantly lower than that of arteries (43/48, 90%, p < 0.05). The sensitivity and specificity of 2D TOF MRA were 77% (10/13) and 100% (83/83), respectively, in 96 evaluable vessels of nine patients. 2D TOF MRA of mediastium and pulmonary hili is clinically feasible, and may be useful because of its high specificity.

Aged↗
PubMed1992

Value of three-dimensional surface display of brain perfusion imaging. Comparison with tomographic imaging.

The diagnostic ability of a three-dimensional surface display of I-123 IMP brain scintigrams and tomographic images was compared in 12 patients who underwent I-123 brain tomography for cerebral cortical hypoperfusion. Foci of decreased accumulation were independently diagnosed by four radiologists, first with transaxial images, second with three-dimensional images, and finally with both images subjectively compared for the purpose of diagnosing the existence, localization, and extent of lesions. Six different lesions (0 to 3 lesions/radiologist) were found only on the transaxial images, but 30 different lesions (1 to 14 lesions/radiologist) were found on the three-dimensional images. In 9 out of 12 cases, the three-dimensional images were regarded as superior for evaluating the extension of the lesion and for lesion existence and lesion localization in 5 out of 12 (P less than 0.05). In conclusion, a three-dimensional display of an I-123 IMP brain tomogram is superior to tomographic images in diagnosing the extent of cerebral cortical hypoperfusion. However, the display is not superior to tomographic images for diagnosing the existence and localization of hypoperfusion.

Amphetamines↗
PubMed1992

[A case of meningioma with non-accumulation of 99mTc-ECD and increased accumulation of 99mTc-HMPAO in the tumor].

99mTc-ECD SPECT and 99mTc-HMPAO SPECT with or without Matas test were performed in a 62-year-old woman with meningioma in the left anterior cranial fossa. After injection of 740 MBq 99mTc-ECD or HMPAO, 64 projection images were collected with a rotating Gamma camera. Matas test was carried out by compressing the left common carotid artery for about one minute immediately after RI injection. Although 99mTc-ECD SPECT showed non-accumulation in the tumor, 99mTc-HMPAO SPECT demonstrated increased accumulation in it. This area of increased accumulation disappeared on 99mTc-HMPAO SPECT with Matas test which causes decrease in blood flow of the tumor. These findings suggest 99mTc-ECD and 99mTc-HMPAO have a different mechanisms of accumulation in the meningioma.

Cysteine↗
PubMed1992

[Three-dimensional display of 99mTc-MIBI myocardial scintigraphy].

One of 99mTc-hexakis, 99mTc-methoxyisobutyl isonitrile (MIBI), has been demonstrated to have a myocardial uptake proportional to regional coronary blood flow. In this study, 99mTc-MIBI myocardial scintigraphy were performed for 16 patients with ischemic heart disease. After injection of 740 MBq of 99mTc-MIBI, 64 projection images were collected during a 360-degree rotation. Three-dimensional (3D) display of the left ventricle was reconstructed with depth-shading method from 99mTc-MIBI SPECT images, which were reconstructed by filtered back projection method. In 9 of the patients, left ventricular cineangiography were performed as diagnostic gold standard. Four physicians blinded to patients' clinical informations interpreted 3D images and SPECT images on separate occasions. Diagnosis of hypoperfusion by 3D displays agreed with those of SPECT in 92.9% (104/112 segments), and disagreed in 7.1% (8 segments). Sensitivity and specificity of 3D images were 87.0 and 93.9%, which were not statistically different (p less than 0.05) from that of SPECT images (91.3, 97.0%). Receiver operating characteristic (ROC) analysis revealed nearly identical curves for the two. Although 3D display had nearly identical diagnostic ability with SPECT, observers reported that 3D images were easier to diagnose than SPECT images. An advantage of the 3D display is that the display gives a more realistic impression of the left ventricle to an observer than tomography or planar imaging. Another advantage is that 3D display can reduce the amount of data storage compared with that of SPECT. In conclusion, 3D images may be useful for diagnosis of hypoperfusion of left ventricle.

Adult↗