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Biomedical subjects

T Aburano

Publications and source records attributed to T Aburano.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Clinical study of cerebral blood flow in unilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT].

Cerebral blood flow (CBF) measured by 99mTc-HMPAO SPECT before operation was studied in 60 patients with unilateral chronic subdural hematoma. The regional CBF was measured in 26 regions of the fronto-occipital 10 cortices, putamen, thalamus and cerebellar hemisphere on both sides. Sixty cases with unilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 17 cases with headache (headache group), 34 cases with hemiparesis (hemiparesis group) and 9 cases with consciousness disturbance or dementia (consciousness disturbance group), and into three groups on the basis of the degree of midline brain shift on MRI: 7 cases of mild shift group, 24 cases of moderate shift group and 29 cases of severe shift group. The average CBF in 60 patients in each region indicated that the regional CBF was reduced in frontal, occipital cortices and cerebellum on the non-hematoma side, and in putamen and thalamus on the hematoma side. In the headache group, the regional CBF reduction on the non-hematoma side was found in only frontal and occipital cortices compared with the corresponding regions on the hematoma side. In the hemiparesis group, the regional CBF was reduced in frontal and occipital cortices on the non-hematoma side and in putamen and thalamus on the hematoma side. The part of CBF reduction in both hemispheres was also noted in the hemiparesis group. In the consciousness disturbance group, the CBF reduction was markedly noted in whole brain. The CBF reductions in frontal and occipital cortices on the non-hematoma side and in putamen, thalamus and cerebellum on the hematoma side was not mutually related with the degree of midline brain shift. We concluded that the disturbance of CBF in chronic subdural hematoma was started from frontal and occipital cortices on the non-hematoma side observed in the headache group, and which was extended to putamen and thalamus on the hematoma side and a part of both hemispheres observed in the hemiparesis group. And such disturbance was finally observed as the CBF reductions in whole brain in the consciousness disturbance group.

Adolescent↗
PubMed2000

[Study on evaluation method of patient dose in diagnostic radiology required for introducing the guidance level: investigation of entrance surface dose of patient using direct measurement by TLD].

Using direct measurement, we investigated entrance surface doses of patients for routine radiographs in attempt to develop evaluation methods of patient dose in order to establish the guidance level in Japan. To date, patient doses have been evaluated by calculations based on radiographic conditions, or model experiments using phantoms. Their patient doses are then evaluated based on several assumptions. Direct measurement of patient dose is difficult to perform in many patients due to its time requirement, level of expertise required and difficulty in providing an explanation of the procedure to the patient. However, such direct measurement is essential since it incorporates all aspects of radiography from the radiographic equipment used, to the actual conditions of each patient without assumption. In this study, we examined the (1) need for introducing the guidance level, (2) controversial points in the calculation method for patient dose evaluation, (3) evaluation accuracy required for introducing the guidance level, and (4) necessity for a standardized method.

Guidelines as Topic↗
PubMed2000

[Clinical study of cerebral blood flow in bilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT].

Cerebral blood flow(CBF) in 34 patients with bilateral chronic subdural hematoma was measured by 99mTc-HMPAO SPECT before operation. The regional CBF was measured in 26 regions of the 10 cortical regions, putamen, thalamus and cerebellar hemisphere on both sides. According to the thickness of subdural hematoma, the thicker hematoma side was measured and examined as the thick hematoma side, and the other side as the thin hematoma side. Thirty four cases with bilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 13 cases with headache(headache group), 10 cases with hemiparesis(hemiparesis group), 5 cases with tetraparesis(tetraparesis group) and 6 cases with consciousness disturbance or dementia(consciousness disturbance group), and into two groups according to the degree of midline brain shift on MRI: 14 cases of non-shifted group and 20 cases of shifted group. The average CBF of 34 patients in each region indicated a regional CBF reduction in the frontal, parietal and occipital cortices on the thin hematoma side, and in the putamen on the thick hematoma side. In the headache group, the regional CBF reduction on the thin hematoma side was found in the frontal, parietal and occipital cortices compared with the corresponding regions on the thick hematoma side, and in thalamus on the thick hematoma side. In the hemiparesis and tetraparesis groups, there was no statistically significant CBF reduction between the thick and thin hematoma sides. In the consciousness disturbance group, the CBF reduction in whole brain was remarkably significant. By the degree of the midline brain shift, the CBF reductions between the thick and thin hematoma sides were observed. Namely, in the shifted group, the CBF reductions were noted in the frontal, parietal and occipital cortices in the thin hematoma side, and in the putamen in the thick hematoma side. We concluded that the CBF reduction of bilateral chronic subdural hematoma was bilaterally found in the hemiparesis and tetraparesis groups, and which was finally observed in whole brain in the consciousness disturbance group.

Adult↗
PubMed1999

Combination radioimmunotherapy with local hyperthermia: increased delivery of radioimmunoconjugate by vascular effect and its retention by increased antigen expression in colon cancer xenografts.

Hyperthermia (HT) may increase tumor targeting of a radiolabeled antibody by its effects on tumor vasculature and antigen expression. Expression of a 45-kDa glycoprotein antigen on LS180 colon cancer cells was 2.7-fold enhanced 2 days after heating at 43 degrees C for 1 h. Preferential tumor accumulation of 125I-A7 recognizing this antigen was doubled and the antitumor effect of 131I-A7 was significantly improved by HT. Hyperthermia also increased tumor uptake of an irrelevant antibody but its radioactivity was rapidly cleared. These results indicate that HT increased the initial delivery of an antibody to a tumor by its vascular effect, and radioactivity was retained in tumors by increased specific binding, resulting in a better radioimmunotherapy outcome.

Animals↗
PubMed1999

Sub-super bone scan caused by bone marrow involvement of prostate cancer.

A 67-year-old man presented with malaise and marked anemia. A diagnostic workup revealed severe pancytopenia on a complete blood count and diffuse sclerotic change in the axial skeleton on a plain abdominal radiograph. Bone metastases being suspected from these findings, bone scintigraphy was performed. The bone scan demonstrated uniformly increased skeletal activity with faint soft-tissue activity. The findings of the bone scan, however, appeared atypical of the super scan caused by diffuse bone metastases, without any decrease in radioactivities of the appendicular skeleton and kidneys. Bone marrow scintigraphy with In-111 chloride demonstrated central marrow failure and peripheral expansion, which indicated the possibility of myelophthisis. The patient underwent bone marrow biopsy, which revealed replacement of the bone marrow by metastatic adenocarcinoma. Further examinations detected the primary lesion in the prostate. In this case, the findings of the bone scan were insufficient for the super scan, and might be categorized as a sub-super scan. It would be important to recognize this incomplete form of super scan as a rare scintigraphic pattern of diffuse bone marrow metastases.

Adenocarcinoma↗
PubMed1999

Efficacy, toxicity and mode of interaction of combination radioimmunotherapy with 5-fluorouracil in colon cancer xenografts.

PURPOSE: The feasibility of radioimmunotherapy (RAIT) combined with 5-fluorouracil (5-FU) was examined in colon cancer xenografts. The mode of interaction of the two treatments was also investigated. METHODS: Mice bearing human colon cancer were treated with a combination of 4.63 MBq (L-RAIT) or 9.25 MBq (H-RAIT) (131)I-A7, an IgG1 against 45-kDa glycoprotein, and 5-FU at a dose of 30 mg kg(-1)day(-1) for 5 days. Myelotoxicity was monitored by blood cell counts and intestinal toxicity was assessed by the dosimetry. The results were compared with those of a single-modality therapy. RESULTS: The combination of 5-FU with H-RAIT enhanced the antitumor effect, improving the tumor quadrupling time from 25.3 +/- 9.59 days to 31.3 +/- 8.32 days (P < 0.05) and inducing tumor regression in 7 out of 10 mice, compared to 3 out of 9 mice treated with H-RAIT alone. The efficacy of L-RAIT was also improved by the combination. Analysis of the dose/response relationship showed an additive interaction of the two modalities. The combination of 5-FU with RAIT induced slightly more severe myelotoxicity than a single-modality treatment, but blood cell counts recovered similarly. Dose estimation suggested that RAIT does not increase the intestinal toxicity of 5-FU. CONCLUSION: The combination of two modalities would be feasible for the treatment of colon cancer, increasing antitumor effect with minor effect on toxicity.

Animals↗
PubMed1999

Experimental investigation of I-123 iodoamphetamine in the detection of lung cancer.

Experimentally we investigated the detection of lung cancer with N-isopropyl-p-I-123-iodoamphetamine (I-123 IMP). Various tumors including Lewis lung cancer were used as tumor models. Serial images were obtained. Biodistribution of Lewis lung cancer was performed. In Lewis lung cancer good visualization as in B-16 melanoma and high tumor accumulation were found with IMP. In conclusion, due to its greater accumulation almost equivalent to that in melanotic melanoma, I-123 IMP may have a role in the detection of lung cancer.

Animals↗
PubMed1999

Reversible cerebral hypoperfusion observed with Tc-99m HMPAO SPECT in reversible dementia caused by hypothyroidism.

A 69-year-old man had hypothyroid dementia as a result of I-131 therapy and an overdose of methimazole. Tc-99m HMPAO SPECT revealed diffuse cerebral hypoperfusion. The findings of brain SPECT normalized with the disappearance of symptoms and a return to the euthyroid state. There was a 25% or 26% reduction of the mean cerebral blood flow during dementia. This may be the first report in which SPECT brain imaging revealed reversible hypoperfusion associated with reversible hypothyroid dementia.

Aged↗
PubMed1999

Differential uptake of TI-201 by small-cell lung cancer in a patient with pneumoconiosis-related pulmonary nodules.

A 68-year-old man with pneumoconiosis was thought to have small-cell lung cancer based on the results of a biopsy of a bone tumor. Three pulmonary nodules were observed on a chest radiograph. Compared with a chest radiograph taken 4 months earlier, one of the nodules had grown. It was difficult to differentiate this nodule from pneumoconiosis-related benign pulmonary nodules from the appearance on the chest radiograph and CT. Ga-67 scintigraphy and TI-201 lung SPECT were performed to characterize these nodules. TI-201 SPECT showed differential high uptake in the enlarged nodule, whereas Ga-67 scintigraphy showed equally intense uptake in all these nodules. Transbronchial biopsy of the nodule that showed high TI-201 uptake revealed cancer cell nests against a background of interstitial fibrosis. The pathologic diagnosis was small-cell lung cancer that had developed in lung scar tissue. This case suggests the utility of TI-201 in scintigraphic assessments of pneumoconiosis-related pulmonary nodules when lung cancer is suspected.

Aged↗
PubMed1999

Early response of tumour to radiotherapy should be assessed by both uptake and retention of single photon tracers: in vitro analysis with 201Tl-chloride, 99Tcm-sestamibi and 99Tcm-tetrofosmin in human bladder cancer cells and human leukocytes.

The uptake and retention of single photon tracers in irradiated tumour cells was observed in an attempt at the early evaluation of the effect of radiation. T24 human bladder cancer cells were exposed to a single dose of 10 Gy or 20 Gy or a fractionated dose of 10 Gy (2 Gy for 5 days). The uptake of 201Tl chloride, 99Tcm-sestamibi and 99Tcm-tetrofosmin was observed by incubating in vitro for 60 min. The retention of the tracers was observed at 60 min after changing the incubation medium for a tracer-free medium. Uptake per culture well of all tracers in the cells exposed to 20 Gy declined as viable cell number decreased, but uptake per cell increased progressively. Uptake per cell of all tracers in the cells exposed to either a single dose or a fractionated dose of 10 Gy also increased, while a delay in growth was observed. The retention of these tracers decreased during this period and recovered thereafter. A binding assay with purified human leukocytes indicated that assessment with 99Tcm-sestamibi and 99Tcm-tetrofosmin is influenced by inflammatory cells. In conclusion, the effect of radiation may be underestimated if assessed by tracer uptake alone because of the increase in tracer uptake in viable irradiated cells. Observation of the retention of tracers may provide additional information.

Humans↗
PubMed1999

[Bacterial mutation in high magnetic fields and radiofrequency radiation].

Epidemiological studies recently have indicated that magnetic fields and radiofrequency (RF) radiation have an adverse influence on the living body. The purpose of this study was to examine the safety of magnetic resonance imaging (MRI) by observing whether bacterial mutation occurs in an approximate MRI environment. We employed a GX-270 FT-NMR unit (JEOL, Ltd.) with a magnetic field strength of 6.3 Tesla. The Salmonella typhimurium tester strains used in the AMES test were exposed, and the incidence of point and frameshift mutations was evaluated. TA98 and TA7001-7006 mixed strains were used to detect frameshift and point mutations, respectively. Tester strains were exposed to the 6.3 Tesla magnetic field with RF radiation (90 degrees and 180 degrees refocusing pulses were repeated using the hydrogen Lamor frequency at 2-second intervals) for 15, 30, 45, and 60 minutes. After each exposure, the rate of revertant mutation was counted. The rates of revertant mutation in mixed strains and the TA98 strain were not statistically significant. Therefore, it was concluded that bacterial mutation is not increased by RF radiation under a 6.3 Tesla magnetic field.

Electromagnetic Fields↗
PubMed1999

Preoperative assessment of residual hepatic functional reserve using 99mTc-DTPA-galactosyl-human serum albumin dynamic SPECT.

UNLABELLED: Preoperative assessment of residual hepatic functional reserve offers important strategic information for hepatic resection. To predict the postoperative residual liver function, we assessed the value of hepatic 99mTc-diethylenetriamine pentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) clearance estimated by dynamic SPECT analysis. METHODS: We investigated 114 consecutive patients with liver disease, including 55 hepatectomy cases. One minute after injection of 185 MBq 99mTc-GSA, 15 serial dynamic SPECT images were obtained every minute. The initial five sets of SPECT images were analyzed by Patlak plot to estimate the sequential initial hepatic 99mTc-GSA clearance (mL/min) as an index of hepatic function. The sum of hepatic 99mTc-GSA clearance of the segments immune from resection was categorized as predicted residual 99mTC-GSA clearance. In the hepatectomy cases, scintigraphy was performed before and 37 +/- 10 d after the operation. RESULTS: Good correlation was observed between the total hepatic 99mTc-GSA clearance and conventional hepatic function tests: plasma retention rate of iodocyanine green (ICG) at 15 min (ICG R15), r = -0.600, P < 0.0001, n = 94; plasma disappearance rate of ICG (K ICG), r = 0.670, P < 0.0001, n = 83; cholinesterase, r = 0.539, P < 0.0001, n = 121; serum albumin, r = 0.421, P = 0.0001, n = 123; and hepaplastin test, r = 0.456, P < 0.0001, n = 120. There was good correlation between the predicted residual 99mTc-GSA clearance and the postoperative total hepatic 99mTc-GSA clearance in patients who underwent segmentectomy or lobectomy (r = 0.84, P < 0.0001, n = 28) and between the pre- and postoperative total hepatic 99mTc-GSA clearance in patients who underwent subsegmentectomy (r = 0.91, P < 0.0001, n = 25). Five patients who had postoperative complications due to hepatic insufficiency (2 patients died of postoperative hepatic failure within 2 mo after operation) showed significantly lower predicted residual 99mTc-GSA clearance compared with the patients without complications (90.3 +/- 37.2 versus 320.9 +/- 158.8 mL/min; P < 0.005). CONCLUSION: The total hepatic 99mTC-GSA clearance reflected hepatic function. In addition, preoperative predicted residual hepatic 99mTc-GSA clearance was a good indicator of postoperative hepatic function and early prognosis. 99mTc-GSA dynamic SPECT is assumed to be a useful method for determining the surgical strategy in patients with hepatic tumor and especially in patients with hepatic dysfunction.

Coloring Agents↗
PubMed1998

Demonstration of double-chambered right ventricle on myocardial perfusion SPECT.

A 19-year-old man with a double-chambered right ventricle (DCRV) and an associated ventricular septal defect was admitted to the hospital for surgical correction. Preoperative study of myocardial perfusion with Tc-99m tetrofosmin SPECT depicted the two chambers of the right ventricle. There was a substantial differential in the radioactive uptake between these two chambers. The inflow and outflow chambers with different peak-pressures (94 and 18 mm Hg) showed different uptakes reflecting the pressure difference, which was intense in the inflow chamber and weak in the outflow.

Adult↗
PubMed1998

Tc-99m leukocyte imaging for evaluating disease severity and monitoring treatment response in ulcerative colitis: comparison with colonoscopy.

The diagnostic value of Tc-99m leukocyte imaging for evaluating disease activity and monitoring treatment response in ulcerative colitis was compared with that of colonoscopy. A total of 48 studies were performed in 28 patients with ulcerative colitis. Forty-six studies had both Tc-99m leukocyte imaging and colonoscopy within 2 weeks of each other, and the remaining two studies had only Tc-99m leukocyte imaging. In 46 studies, semiquantitative grading of colonic radioactivity by comparison with iliac crest marrow activity on radionuclide imaging correlated well with macroscopic grading based on Matts' criteria on colonoscopy. Fourteen (82%) of 17 studies with slight colonoscopic change showed a negative result on the radionuclide image. In 15 patients treated with glucocorticoids or leukapheresis, radionuclide imaging showed nearly the same statistical results as colonoscopy in monitoring treatment response. Tc-99m leukocyte imaging could be used as an alternative to colonoscopy to evaluate the disease activity of ulcerative colitis or to monitor the treatment response, although it is insensitive for detecting disease with only slight macroscopic changes.

Adult↗