Biomedical subjects

M Tanabe

Publications and source records attributed to M Tanabe.

At least 55 records · Page 3Linked to original sources

PubMed2000

Comparative evaluation of Tc-99m MIBI and Tl-201 chloride SPECT in non-small-cell lung cancer mediastinal lymph node metastases.

PURPOSE: To compare the utility of Tc-99m MIBI SPECT and Tl-201 chloride SPECT for presurgical assessment of lung cancer mediastinal lymph node metastases. METHODS: Forty-one patients with non-small-cell lung cancer underwent dual-isotope imaging with Tl-201 chloride and Tc-99m MIBI and were evaluated for mediastinal lymph node involvement. RESULTS: The sensitivity rates of early and delayed Tc-99m MIBI SPECT and of early and delayed Tl-201 chloride SPECT for detecting mediastinal nodal metastases were 69%, 69%, 92%, and 92%, respectively. The corresponding specificity rates were 96%, 96%, 93%, and 96%. CONCLUSION: Tl-201 chloride SPECT is superior to Tc-99m MIBI SPECT when used to detect mediastinal lymph node metastases in patients with non-small-cell lung cancer.

Adult↗

PubMed2000

Diagnostic value of TI-201 and three-phase bone scintigraphy for bone and soft-tissue tumors.

PURPOSE: Although TI-201 is highly sensitive for detecting bone and soft-tissue tumors, its uptake is not specific for malignant lesions. This study assessed the differentiation of malignant and benign lesions and evaluated the sensitivity, specificity, and accuracy of TI-201 imaging and three-phase bone scans. MATERIALS AND METHODS: Forty bone and soft-tissue tumors (16 malignant and 24 benign) were evaluated. TI-201 static images were acquired 10 minutes (early) and 2 hours (delayed) after injection of the radionuclide. Within 14 days, three-phase bone scintigraphy was performed using Tc-99m HMDP with the patient in the same position. The count ratio of the lesion compared with the normal contralateral or adjacent site (L:N ratio) was measured. RESULTS: With TI-201 scintigraphy, mean (+/- SD) values of early and delayed L:N ratios were 3.36 +/- 1.25 and 2.88 +/- 1.20, respectively, in malignant lesions; and 1.88 +/- 1.14 and 1.48 +/- 0.76, respectively, in benign lesions. TI-201 accumulation in benign lesions was significantly less than that of malignancies on early and delayed images. However, an overlap of both ratios between malignant and benign lesions was seen. No such significance was detected on three-phase bone scintigraphy (L:N ratios of malignant and benign tumors were 2.57 +/- 1.22 and 2.24 +/- 2.11, respectively, for blood flow imaging; 2.41 +/- 0.78 and 2.26 +/- 1.54, respectively, for blood pool imaging; and 2.80 +/- 2.10 and 2.89 +/- 4.55, respectively, for bone imaging). When we assumed that the tumor was malignant when the delayed TI-201 L:N ratio exceeded the blood pool phase L:N ratio with bone scintigraphy, the sensitivity rate was 81%, specificity rate was 100%, and accuracy rate was 93%. CONCLUSIONS: TI-201 imaging for bone and soft-tissue tumors was better than three-phase bone scintigraphy alone but was not good enough to clearly differentiate malignant lesions from benign ones. TI-201 scintigraphy, performed in combination with three-phase bone scintigraphy, may be superior to either one of the two imaging procedures alone for bone and soft-tissue tumor diagnosis.

Adolescent↗

PubMed2000

Comparative study of Tc-99m MIBI and TI-201 SPECT in predicting chemotherapeutic response in non-small-cell lung cancer.

PURPOSE: Tc-99m MIBI can be excluded from cytosol against its concentration gradient as a suitable transport substrate by P-glycoprotein. Tc-99m MIBI has also been shown to be more effective than TI-201 chloride for evaluating the response to chemotherapy in patients with small-cell lung cancer. The relation between Tc-99m MIBI accumulation by the tumor and its response to chemotherapy were evaluated in patients with non-small-cell lung cancer (NSCLC) and compared with the same parameters achieved using TI-201 chloride. METHODS: Thirty-eight patients with NSCLC were examined before chemotherapy was begun. They were classified according to the results of a follow-up computed tomogram into two groups: responders were patients in whom there was a > or =50% decrease and nonresponders were patients in whom there was a <50% decrease in the sum of the product of the maximum perpendicular diameters of all measurable lesions. All patients underwent dual-isotope imaging with TI-201 chloride and Tc-99m MIBI just before chemotherapy. Regions of interest were placed over the tumor uptake (T) and contralateral normal lung tissue (N) areas on one coronal view with a clearly defined lesion, and the T:N ratio and retention index were calculated. RESULTS: The delayed T:N ratio and retention index for Tc-99m MIBI in the responder group were significantly greater (P<0.05) than those in the nonresponder group. There was no significant correlation between the T:N ratio and retention index and tumor response using TI-201 chloride. CONCLUSION: Tc-99m MIBI SPECT may be more effective than TI-201 chloride SPECT for evaluating the response to chemotherapy in patients with NSCLC.

Adult↗

PubMed2000

Comparison of 99Tcm-tetrofosmin with 201Tl and 131I in the detection of differentiated thyroid cancer metastases.

The purpose of this study was to assess the detectability of metastatic lesions by 99Tcm-tetrofosmin in differentiated thyroid cancer, and to compare the results with those obtained using 201Tl-chloride and tracer doses of 131I. Twenty-four thyroidectomized patients with metastases were studied. There were 34 metastases, including 16 lung, nine lymph node and nine bone. Radiological studies (chest X-ray, computed tomography and magnetic resonance imaging), serum thyroglobulin assays and histopathological examinations were performed to verify the presence of metastases with positive uptake of the three radionuclides. Increased accumulation of 99Tcm-tetrofosmin was observed in 11 of 16 (68.8%) lung metastases, eight of nine (88.9%) lymph node metastases and eight of nine (88.9%) bone metastases. Increased accumulation of 201Tl and 131I was observed in 11 of 16 (both) (68.8%) lung metastases, eight (88.9%) and three (33.3%), respectively, of lymph node metastases and eight (88.9%) and nine (100%), respectively, of bone metastases. The detectability of thyroid cancer metastases using 99Tcm-tetrofosmin, 201Tl and 131I was 79.4%, 79.4% and 67.6%, respectively. The combined detectabilities of 99Tcm-tetrofosmin and 131I and of 201Tl and 131I were both 88.2%. 99Tcm-tetrofosmin and 201Tl imaging were found to be more sensitive than 131I for the detection of differentiated thyroid cancer metastases, particularly for regional lymph node. The combination of 99Tcm-tetrofosmin and 131I imaging may be a more sensitive and effective method for detecting metastases in differentiated thyroid cancer.

Adenocarcinoma, Follicular↗

PubMed2000

Multivariate analysis of patients with head injury using quantification theory type II--with special reference to prediction of patient outcome.

Quantification theory type II was used to predict the outcome of 63 patients with head injury. Age, sex, two factors based on neurological examination, and seven factors based on findings of skull radiography and computed tomography of the head were selected as predictors. Patient outcome was evaluated 6 months after injury and assigned to good recovery, severe disability, or death. Discriminant analysis of patient outcomes was performed using the 11 factors. Two category scores were obtained for each category, since the highest correlation ratios were 0.869 and 0.252, and others were less than 10(-15). For each patient, a pair of sample scores was then obtained by simple summation of the 11 category scores. Pairs of sample scores were plotted, and the three groups of patient outcomes were clearly distinguishable without exception. These findings show that the outcome of patients with head injury can be accurately discriminated by quantitative analysis of qualitative data.

Adolescent↗

PubMed2000

Soft-wall reconstruction for cholesteatoma surgery: reappraisal.

OBJECTIVE: To reevaluate the validity of the soft-wall reconstruction method of the posterior meatal wall in surgeries for cholesteatomas. STUDY DESIGN: Retrospective case review. PATIENTS: Subjects consisted of 52 patients (54 ears) with fresh cholesteatoma (excluding residual or recurrent cholesteatomas) who were operated by the soft-wall reconstruction method in our clinic and observed for more than 2 years after surgery, and 29 patients (29 ears) who were operated by canal-wall-down and open method. MAIN OUTCOME MEASURES: Postoperative period required for complete epithelization (dry ear), hearing, and incidence of the residual and recurrent cholesteatomas were compared with those operated by canal-wall-down and open method. The postoperative conditions of the soft posterior meatal wall was also investigated. RESULTS: Postoperative period to be a dry ear was significantly shorter in the soft-wall reconstruction group than in the canal-wall-down and open group (Student's t-test, t = 2.99, p < 0.01). There was no significant difference in the postoperative hearing or incidence of residual and recurrent cholesteatomas between the two groups. CONCLUSIONS: These results indicate that the soft-wall reconstruction method seems more versatile than the canal-wall-down and open method for cholesteatoma surgery.

Acute Disease↗

PubMed2000

Visualization of the motor activation area using SPECT in neurosurgical patients with lesions near the central sulcus.

UNLABELLED: The purpose of this study was to visualize the motor area related to finger movement and a fist-making task using SPECT in patients with lesions near the central sulcus. METHODS: Eleven patients (9 with a brain tumor, 1 with cerebral infarction, and 1 with an arteriovenous malformation) were investigated. The first intravenous injection of 99mTc-ethyl cysteinate dimer (ECD) for the motor activation SPECT images was administered 2 min after completion of the fist-making task with the hand contralateral to the brain lesion. The movement was stopped 2 min after injection, and activation SPECT was performed. After the scan, the second dose of 99mTc-ECD was injected into resting patients, and a second set of SPECT images was acquired. The first set of images was subtracted from the second set to obtain control images. Regions of interest were set bilaterally on the sensorimotor hand area; the supplementary motor area; the frontal, temporal, and occipital lobes; and the cerebellar hemispheres. The results of activation SPECT were expressed as positive or negative for a high-count area, and the regional percentage change for activation images relative to resting images was calculated. RESULTS: Visual assessment of activation images was positive in 9 patients for the sensorimotor hand area and 7 patients for the supplementary motor area. The regional percentage change between activation and resting images for the high-count areas was 19.7% for the sensorimotor hand area and 18.2% for the supplementary motor area. Both values were significantly higher than those for other areas (P<0.05). CONCLUSION: Motor activation SPECT using a 99mTc-ECD split-dose method is easy to perform and may be helpful for presurgical visualization and identification of the sensorimotor hand area or the supplementary motor area.

Brain Mapping↗

PubMed2000

[Three-dimensional cholangiography and angiography for hilar cholangiocarcinoma].

Cholangiography is the most fundamental and reliable examination for diagnosis of the extent of bile duct carcinoma. Hepatic angiography is also informative for diagnosis of vascular invasion. However, an accurate understanding of three-dimensional biliary and vascular anatomy at the hepatic hilum is not easily gained by conventional cholangiography and angiography. We have performed three-dimensional cholangiography and angiography (3D-CG & AG) using rotational DSA (Advantx ACT) and a 3D spinning digital imaging system in 29 patients with hilar cholangiocarcinoma, etc. 3D-CG & AD provides clear three-dimensional visualization of the biliary tract and blood vessels affected by bile duct cancer, and useful information on optimal resection. Of 13 patients with hilar cholangiocarcinoma undergoing resection, curative resection was carried out in 11 (85%). 3D-CG & AG is considered to be an indispensable imaging modality for evaluation of the extent and staging of hilar cholangiocarcinoma.

Angiography↗

PubMed2000

Comparative studies for development of Schistosoma mansoni sporocysts in Puerto Rican and Brazilian Biomphalaria glabrata.

The development of sporocysts of Schistosoma mansoni was monitored in pigmented and albino Biomphalaria glabrata from Puerto Rico and Brazil. The snails were exposed individually to 20 miracidia, and sporocysts were allowed to develop for 3 to 12 weeks. Most of the immature sporocysts were found in the seminal receptacle sac and vas deferens during development. In contrast, mature daughter sporocysts were detected everywhere except in the foot at 12 weeks after exposure to the miracidia. It was found that mature daughter sporocysts formed more rapidly in the pigmented than in the albino snails, but no difference was observed in the formative time between the same types of Puerto Rican and Brazilian snails. It seems likely that there is a correlation between the infection rate and the time required for formation of mature daughter sporocysts in B. glabrata.

Animals↗

PubMed2000

[Results of radioiodine therapy in patients with pulmonary metastases of differentiated thyroid cancer].

Factors affecting the effect of 131I treatment and survival after pulmonary metastases in patients with differentiated thyroid cancer, were studied. Between 1984-1999, pulmonary metastases was observed in 51 out of 153 patients with differentiated thyroid cancer at our institution. Of these 41 patients had papillary and 10 follicular thyroid cancer. There were 37 females and 14 males with mean age (+/- S.D.) of 50.5 +/- 19.0 years. These 51 patients were subjected to 131I therapy. The effect of 131I treatment and the prognostic values of the following variables were examined: sex, age at the time of 131I treatment, histologic type of cancer, size of pulmonary metastases on CT, total-body scintigraphy with 201Tl and 131I, serum thyroglobulin levels and presence of metastases in distant sites other than lung. The effect of 131I treatment was evaluated by means of changes in the number and size of metastatic shadows on chest CT and by serum thyroglobulin levels. The minimum duration of follow-up was 12 months. Therapeutic 131I dose scans revealed detectable uptake in 25 of 51 patients. Therapeutic 131I dose uptake was achieved more frequently in patients under 40 years of age and in those with follicular cancers. Of the 51 patients, 13 were evaluated to be treated successfully. Those under 40 years of age, with 131I uptake in the lung and presence of other metastases showed a good response to treatment than others. Follicular cancer showed a more significant association with coarse type of lung metastases (> 5 mm in diameter on chest CT) and good 131I uptake than papillary cancer. Of all the variables studied, the best prognosis for survival was demonstrated by increased 131I uptake in pulmonary metastases. These results indicate that age, 131I uptake and presence of other metastases are important factors in predicting the effect of 131I treatment for pulmonary metastases of differentiated thyroid cancer.

Adenocarcinoma, Follicular↗

PubMed1999

Mechanical rotation of the c subunit oligomer in ATP synthase (F0F1): direct observation.

F0F1, found in mitochondria or bacterial membranes, synthesizes adenosine 5'-triphosphate (ATP) coupling with an electrochemical proton gradient and also reversibly hydrolyzes ATP to form the gradient. An actin filament connected to a c subunit oligomer of F0 was able to rotate by using the energy of ATP hydrolysis. The rotary torque produced by the c subunit oligomer reached about 40 piconewton-nanometers, which is similar to that generated by the gamma subunit in the F1 motor. These results suggest that the gamma and c subunits rotate together during ATP hydrolysis and synthesis. Thus, coupled rotation may be essential for energy coupling between proton transport through F0 and ATP hydrolysis or synthesis in F1.

Actins↗

PubMed1999

The mammalian HSF4 gene generates both an activator and a repressor of heat shock genes by alternative splicing.

The expression of heat shock genes is controlled at the level of transcription by members of the heat shock transcription factor family in vertebrates. HSF4 is a mammalian factor characterized by its lack of a suppression domain that modulates formation of DNA-binding homotrimer. Here, we have determined the exon structure of the human HSF4 gene and identified a major new isoform, HSF4b, derived by alternative RNA splicing events, in addition to a previously reported HSF4a isoform. In mouse tissues HSF4b mRNA was more abundant than HSF4a as examined by reverse transcription-polymerase chain reaction, and its protein was detected in the brain and lung. Although both mouse HSF4a and HSF4b form trimers in the absence of stress, these two isoforms exhibit different transcriptional activity; HSF4a acts as an inhibitor of the constitutive expression of heat shock genes, and hHSF4b acts as a transcriptional activator. Furthermore HSF4b but not HSF4a complements the viability defect of yeast cells lacking HSF. Moreover, heat shock and other stresses stimulate transcription of target genes by HSF4b in both yeast and mammalian cells. These results suggest that differential splicing of HSF4 mRNA gives rise to both an inhibitor and activator of tissue-specific heat shock gene expression.

Alternative Splicing↗

PubMed1999

Ubiquitous and cell-specific members of the avian small heat shock protein family.

Small heat shock proteins (sHsps) have been suggested to act as molecular chaperones for many kinds of substrates and have protective roles in cells exposed to external stresses. Unlike other major Hsps such as Hsp70 and Hsp90, expression of many vertebrate sHsps is restricted to the muscle tissues and/or eye lens. Among the sHsps, the heat-inducible human Hsp27 (hHsp27) homologue is believed to be expressed ubiquitously in various cell types. Here, we distinguished the chicken homologue of hHsp27 (cHsp24) from the chicken major heat-inducible protein of molecular size 25 kDa (cHsp25). cHsp25 is not expressed in the absence of stress, but is highly expressed after hyperthermia in all tissues of developing embryos. In contrast, expression of cHsp24 is restricted to some specific tissues even in the presence of stress. Thus, cHsp25 is the first member of the sHsps in vertebrates the expression of which is ubiquitous in tissues exposed to external stresses similar to Hsp70.

Animals↗

PubMed1999

Spatiotemporal dynamics of inositol 1,4,5-trisphosphate that underlies complex Ca2+ mobilization patterns.

Inositol 1,4,5-trisphosphate (IP3) is a second messenger that elicits complex spatiotemporal patterns of calcium ion (Ca2+) mobilization and has essential roles in the regulation of many cellular functions. In Madin-Darby canine kidney epithelial cells, green fluorescent protein-tagged pleckstrin homology domain translocated from the plasma membrane to the cytoplasm in response to increased concentration of IP3. The detection of translocation enabled monitoring of IP3 concentration changes within single cells and revealed spatiotemporal dynamics in the concentration of IP3 synchronous with Ca2+ oscillations and intracellular and intercellular IP3 waves that accompanied Ca2+ waves. Such changes in IP3 concentration may be fundamental to Ca2+ signaling.

Adenosine Triphosphate↗

PubMed1999

Accumulation of technetium-99m pertechnetate in a patient with metastases of thyroid carcinoma.

Accumulation of both Tc-99m pertechnetate and radioiodine upon scintigraphy in thyroid carcinoma and/or in its metastases is a rare occurrence. In this paper we describe a patient who was taken to surgery for left lobectomy of the thyroid with follicular adenocarcinoma and who had accumulation of both I-131 and Tc-99m pertechnetate in lung metastases. The accumulation of I-131 was less than that of Tc-99m pertechnetate. The use of Tc-99m pertechnetate for imaging for diagnosis of functioning thyroid metastases is discussed.

Adenocarcinoma, Follicular↗

PubMed1999

Tc-99m Technegas scintigraphy to evaluate the lung ventilation in patients with oral corticosteroid-dependent bronchial asthma.

Bronchial asthma is a clinical syndrome characterized by the reversibility of airway obstruction. Recently it has been suggested that remodeling of the airway causes irreversible airway obstruction which may be responsible for the patient's symptoms. With this background, the purpose of the present study was to assess patients with corticosteroid-dependent asthma by Tc-99m Technegas scintigraphy (Technegas) in both planar and SPECT images. Twelve patients (7 females and 5 males aged 36-72 years with a median age of 60 years: 4 smokers and 8 non-smokers) with oral corticosteroid-dependent asthma were enrolled in this study. Lung ventilation scanning with Technegas in both planar and SPECT images, high-resolution computed tomography, and pulmonary function tests were performed in all patients. The results of Technegas scanning were graded and correlations with other clinical parameters were evaluated. Significant abnormalities were detected by ventilation scintigraphy with Technegas in patients with corticosteroid-dependent bronchial asthma even during remission. Our data demonstrate that airflow obstruction took place in patients with corticosteroid-dependent asthma even during remission. Technegas scanning appears to be a useful radiopharmaceutical for demonstrating airflow obstruction in patients with bronchial asthma.

Adrenal Cortex Hormones↗

PubMed1999

Visualization of esophageal non-Hodgkin's lymphoma with Ga-67 scintigraphy.

Although non-Hodgkin's lymphoma of the gastrointestinal tract is common, primary esophageal lymphomas represent less than 1% of all gastrointestinal tumors. We report a case of primary non-Hodgkin's lymphoma of the esophagus. Ga-67 scintigraphy showed characteristic intense accumulation in the esophageal wall. The histopathology belonged to the category of mucosa-associated lymphoid tissue lymphoma.

Citrates↗

PubMed1999

The diagnostic and prognostic value of eardrum mobility in otitis media with effusion.

Diagnostic and prognostic values of eardrum mobility were determined by pneumatic otoscopy in 37 patients (56 ears) having otitis media with effusion (OME). Eardrum mobility was impaired or lost in less than half of the ears (46.4%), while a tympanogram detected 77.8% of OME. In 27 of the 37 patients (42 of the 56 ears), aeration of the middle ear space was examined by CT and demonstrated that the presence or absence of aeration was significantly correlated with the presence or absence of eardrum mobility. In another 38 children (62 ears with OME), effect of antibiotics was correlated with eardrum mobility before treatment, and the improvement rate was found to be significantly higher in ears with positive mobility of eardrum (34.3%) than in ears without eardrum mobility (10.0%). These results indicate that eardrum mobility is a good prognostic indicator of OME rather than its diagnostic indicator alone.

Acoustic Impedance Tests↗