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Biomedical subjects

M Mitani

Publications and source records attributed to M Mitani.

At least 37 records · Page 2Linked to original sources
PubMed1999

Potentiation of carbachol-induced amylase release by propionate in guinea pig and vole pancreatic acini.

The action of propionate, one of the major end products of microbial fermentation in herbivores was investigated in isolated, perifused pancreatic acini of guinea pigs, voles, and mice. With the use of guinea pig acini, 100 microM propionate had no effect, whereas 300 and 600 microM increased amylase release by six- and ninefold, respectively. Simultaneous perifusion of carbachol (CCh) 10 microM plus propionate 100 microM in guinea pig acini produced a potentiated secretory response that was 130% higher than the summated value obtained with CCh and propionate alone. The potentiation by propionate (100 microM) of CCh (10 microM)-induced amylase release was also obtained in vole pancreatic acini, but the mouse pancreatic preparation did not exhibit a similar potentiation. In contrast to CCh, propionate (100-600 microM) alone had no significant effect on intracellular Ca2+ concentration ([Ca2+]i) and did not alter [Ca2+]i elicited by CCh. Ca ionophore A23187 (5 microM)-induced amylase release in guinea pig acini was enhanced twofold by the addition of propionate. Cellular cAMP content was increased slightly by propionate, but did not alter dose dependently. The cAMP level with combinations of CCh and propionate was almost same as that with CCh alone and propionate alone. Staurosporine did not modify amylase secretion induced by a combination of CCh and propionate. These results suggest that propionate, in addition to a direct action on amylase release, potentiates CCh-induced amylase release in guinea pig and vole acini via a secretory pathway not associated with an increase in [Ca2+]i and cellular cAMP.

Amylases↗
PubMed1999

[Quantitative study of 99mTc-Technegas SPECT for ventilatory impairment in pulmonary emphysema].

99mTc-Technegas scintigraphy is used to evaluate ventilation abnormalities in patients with pulmonary emphysema. Although abnormalities of ventilation distribution are easy to find, no objective index exits. Evaluation is subjective and differs with each radiologist. Thus, it is difficult to compare cases and the clinical course in the same case. The present study for quantitative evaluation demonstrated an excellent correlations between mean voxel values of the lung and stage classification. Furthermore, a correlation was observed between the mean and FEV1.0%. These findings indicate that the quantitative analysis of SPECT data is useful for classifying clinical stage and comparing cases.

Humans↗
PubMed1999

[A case of successful thromobolytic therapy in a patient with cerebral embolism during angiography].

We report a case of successful thromobolytic therapy in a patient with cerebral embolism during angiography. A 57 year-old male lost his consciousness during angiography. His neurologic symptoms were semi-comatose and right oculomotor palsy. According to these symptoms, we estimated the lesion in the right midbrain. Immediately after we denied a cerebral hemorrhage by computed tomography, we infused 60,000 u of urokinase intravenously within an hour from the onset followed by diffusion weighted magnetic resonance imaging (DW-MRI). DW-MRI showed hyper-intense lesion in the midbrain. We sequentially performed thrombolytic therapy with urokinase by selective cerebral angiography within three hours from the onset. His symptoms gradually resolved, but his consciousness was still confused state. His all neurologic symptom completely resolved in the next day after hyperbaric oxygenation therapy.

Angiography↗
PubMed1998

Relationship between body mass index and transvaginal ultrasonographic endometrial thickness in postmenopausal women.

OBJECTIVE: To investigate the relationship between body mass index (BMI) and transvaginal ultrasonographic endometrial thickness. MATERIALS AND METHODS: Two hundred and twelve postmenopausal Japanese women (mean age, 62.1+/-8.0 years; range 47-85) with histologically proven normal endometrium and with endometrial thickness more than 1.0 mm were studied. Baseline characteristics including age, years since menopause, and BMI were recorded for each subject. The relationship between sonographic endometrial thickness and baseline characteristics was assessed in each subject. RESULTS: BMI was significantly correlated with endometrial thickness (r=0.40, p<0.001), but age and years since menopause were not correlated. On stepwise regression analysis only BMI was still associated with endometrial thickness (R2=0.16, p<0.001). CONCLUSION: Sonographic endometrial thickness differs with BMI in postmenopausal women. Higher BMI is associated with greater endometrial thickness.

Age Factors↗
PubMed1997

Spiral computed tomography with 3-dimensional reconstruction for the diagnosis of tracheobronchial stenosis.

We report on the usefulness of spiral computed tomography (CT) with 3-dimensional (3D) reconstruction in the diagnosis of tracheobronchial abnormalities based on three cases of children with congenital tracheobronchial strictures. Images were reconstructed using a curved planar reformat and shaded surface display. The images obtained from our three cases of tracheal stenosis, subglottic stenosis and tracheobronchial strictures were extremely clear. Spiral CT with 3D reconstruction provides excellent anatomic delineation of the tracheobronchial airway, and is safe and less invasive than tracheobronchography.

Bronchial Diseases↗
PubMed1997

[Digital filing system for medical image data].

To establish practical, effective medical digital image filing systems, various problems remain to be solved. The authors focused on 2 such problems of great importance: image data compression and standard specifications for digital data storage. From a variety of image compression algorithms now available, 2D-Color Doppler image compression was clinically investigated using the Joint Photographic Expert Group (JPEG) method. In low grade compression, the images decompressed showed no significant alterations in image quality, however, in higher grades of compression attained through irreversible coding in the JPEG method, the images showed subtle but significant alterations: emergence of 2 kinds of artifact, i.e., borderline-artifact produced in the DCT procedures and pseudo color spots. The reproducibility of colors was found to be altered by changing the quantization table in the JPEG procedure. It was thought necessary to choose a proper quantization table and examine the DC coefficients (number of pixels) in the DCT procedure to attain practical 2D-Color Doppler image compression by the JPEG method. Although attempts in Japan are being made to establish common standards for electronic data storage, based on MEDIS, in an effort to promote standardization there are many problems to be solved before practical use is possible. To ensure common availability as required by the technical standards, it is necessary to organize minimum-required specifications into common standards and make them open to the public.

Algorithms↗
PubMed1996

Regular and irregular dichotomies of bronchial branching in the human lung.

RATIONALE AND OBJECTIVES: Typical models of the human bronchial tree depict regular branching. However, some anatomic studies also have revealed irregular dichotomies in the human lung. We therefore studied the patterns of bronchial branching in the human lung. METHODS: We examined a normal right lung. Bronchial branchings were traced up to terminal bronchioles (TBs) in both regular and irregular dichotomies. RESULTS: In 256 TBs in peripheral regions, the number of branchings varied from 11 to 23; the largest number was found in the S10c of the basal segment, and the average was 15. In 354 TBs in hilar regions supplied by irregular dichotomies, the number of branchings ranged from 9 to 15, with the average being 10. In secondary pulmonary lobules, bronchioles supplying the secondary pulmonary lobules reached TBs in two or three divisions. CONCLUSION: Irregular dichotomies are too frequent to be neglected in the interpretation of radiologic and physiologic findings.

Aged↗
PubMed1996

Septal structure of incomplete interlobar fissures of the lung.

RATIONALE AND OBJECTIVES: Some septal structures have been observed in the areas of incomplete interlobar fissures (IIFs) in resected lungs. We describe the anatomy of IIFs with or without the presence of septal structures. METHODS: Twenty fused areas from 16 autopsy cases were examined histologically. Other septal structures outside the areas of IIFs also were examined. RESULTS: In 10 of the 20 fused areas, there was a mixture of septal structures with and without defects. In the remaining 10, there were no septal structures. The septal structures consisted of two inner layers from both lobes. Other septal structures examined were the same as ones observed in the IIFs. CONCLUSION: Linear shadows seen at interlobar fissures and on computed tomography scans do not necessarily depict the presence of complete interlobar fissures. The absence of linear shadows does not necessarily imply the absence of septal structures.

Bronchi↗
PubMed1996

Growth hormone (GH)-releasing peptide and GH releasing hormone stimulate GH release from subpopulations of somatotrophs in rats.

The synthetic hexapeptide GH-releasing peptide (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2; GHRP-6) and GH releasing hormone (GHRH) are both potent stimulators of GH release in rats. Using reverse hemolytic plaque assay (RHPA), we have compared the effects of human GHRH and GHRP-6 on GH release from the dispersed individual cells of rat anterior pituitary. In a single RHPA, we quantified the percentage of plaque forming cells (% PFC) and their mean plaque area (MPA) after 30 min-incubation, and calculated a total secretion index (TSI) by multiplying % PFC and MPA. 10 nM GHRH and 100 nM GHRP-6 each caused a significant increase in % PFC (%) (GHRH 39.15, GHRP-6 29.4, vs vehicle 24.3, P < 0.01), MPA (x 10(-2) microns2) (GHRH 124.04, GHRP-6 94.80, vs vehicle 44.57, P < 0.01) and TSI (x 10(-2)) (GHRP-6 32.87, vs vehicle 10.84, P < 0.01). Simultaneous addition of both secretagogues caused a further increase in GH release (%PFC 46.4, MPA 142.55, TSI 69.82, P < 0.01 vs vehicle), although the effect was additive but not synergistic. Somatostatin analog, SMS201-995 (SMS) partially suppressed all parameters in GH secretion after stimulation by GHRH and/or GHRP-6. A double RHPA was then performed to test whether all somatotrophs respond equally to GHRH and GHRP-6 or some cells formed plaques only be either GHRH or GHRP-6. There were somatotrophs responsive to only GHRH (23.3% vs control 6.2%, P < 0.01), those responsive to only GHRP-6 (11.9% vs control 6.1%, P < 0.01), and those responsive to both GHRH and GHRP-6 (7.8% vs control 0.2%, P < 0.01). These results confirmed the previous findings that GHRP-6 and GHRH directly but independently stimulate GH release from the pituitary cells, and further suggest that presence of at least three functionally distinct somatotroph subpopulations concerning the responsiveness to GHRP-6 and GHRH in rats.

Animals↗
PubMed1996

Demonstration of serum-neutralising antibody to turkey rhinotracheitis virus in serum from chicken flocks in Japan.

Since between 1989 and 1991, broiler, broiler breeder and layer chickens reared in three different prefectures of Japan, Hyogo, Ibaraki, and Miyazaki, were diagnosed clinically as having swollen head syndrome (SHS) these flocks were survey for antibody to turkey rhinotracheitis (TRT) virus using a serum neutralisation (SN) test. TRT-specific SN antibody was found in flocks of chickens in 2 out of the 3 prefectures. Thereafter, particular in the summers of both 1993 and 1994 outbreaks of SHS occurred in almost all areas of major chicken production in Japan. Almost chicken flocks affected by SHS possessed TRT SN antibody. No chicken sera collected between 1972 and 1988 possessed any SN antibody to TRT virus. It is suggested that in Japan, TRT virus is widely prevalent in areas of major poultry production.

Animals↗
PubMed1996

[Radiologic-pathologic correlation between tumor edge and surrounding inherent structures in peripheral lung cancer].

PURPOSE: To evaluate the radiologic-pathologic relationship between the tumor edge of peripheral lung cancers and surrounding normal structures. MATERIALS AND METHODS: Tissue samples from 16 lung cancers with diameters less than 2 cm were examined: 7 adenocarcinomas, 5 squamous cell carcinomas, 2 small cell carcinomas, 1 large cell carcinoma, and 1 that had metastasized to the lung. Inflation-fixed lung specimens containing tumor tissue were sliced to a thickness of 2 mm: The tumor edge of each section was traced under a stereomicroscope and its relationship to marginal structure, including bronchi, pulmonary arteries, and pulmonary veins containing interlobular septa, was analyzed. The tumor edge and marginal structures were classified into four types: Type 1, clear margin formed by marginal structures; Type 2, tumor involving the marginal structures; Types 3 and 4, marginal structures penetrating the tumor with and without a notch, respectively. RESULTS: Type 1 was found in 23 of 47 pulmonary arteries (49%), 23 of 49 bronchi (47%), and 12 of 31 pulmonary veins or interlobular septa (39%). Type 2 was found in 11% (14/127), Type 3 in 15% (19/127) and Type 4 in 28% (36/127) of marginal structures. Type 1 was common in all histological types of carcinomas studied. CONCLUSION: In small peripheral lung cancers, the tumor edge sometimes has a clear margin formed by surrounding structures such as interlobular septa. This can make it difficult to differentiate benign from malignant lesions.

Adenocarcinoma↗
PubMed1996

[Comparison between high-resolution computed tomography and 99mTc-technegas SPECT pulmonary emphysema].

Scintigraphy with 99mTc-technegas was recently introduced for clinical imaging of lung ventilation. This method has been found to be useful in emergencies, to be more suitable for single photon emission computed tomography (SPECT) than other agents used in ventilation scintigraphy, and could reveal abnormalities in ventilation more easily than high resolusion computed tomography (HRCT) in pulmonary emphysema. We compared 99mTc-technegas SPECT with HRCT in six regions: the right upper, middle, and lower lobes, the left upper lobe, the lingula, and the left lower lobe, in 15 patients with pulmonary emphysema. Patients with centrilobular emphysema tended to show stronger changes in upper lobes than in lower lobes on both 99mTc-technegas SPECT and HRCT. Some regions showed no change on HRCT but various changes on 99mTc-SPECT. Patients with panlobular emphysema showed severe changes on 99mTc-SPECT in lower lung fields in which well-demarcated areas of low attenuation were not seen on HRCT. We conclude that 99mTc-SPECT is useful for detecting early changes and panlobular changes in pulmonary emphysema.

Adult↗
PubMed1996

[Septal structure of incomplete interlobar fissures of the lung].

We describe the anatomy of incomplete interlobar fissures with and without septal structures. Twenty-eight fused areas in specimens obtained during 21 autopsies were examined histologically. In 12 of the 28 fused areas, there was a mixture of septal structures with and without defects. In the remaining 16, there were some septal structures. Septal structures consisted of inner layers from both lobes. These results suggest that linear shadows at interlobar fissures on computed tomography do not necessarily reflect complete interlobar fissures. Assessment of incomplete interlobar fissure is important with regard to collateral ventilation and pulmonary disease processes.

Humans↗
PubMed1995

Hypersensitivity pneumonitis in a pearl nucleus worker.

A 37-year-old woman had worked for 4 years in a shell-processing factory where considerable airborne dust was produced cutting and polishing fresh water shells into pearl nuclei. She had a dry cough and dyspnea. Transbronchial lung biopsy showed noncaseating granulomas and cellular intraalveolar infiltrates. High-resolution lung computed tomography (HRCT) showed diffuse small nodules and ground-glass opacities. Hypersensitivity pneumonitis caused by shell dust should be considered in the appropriate clinical setting in a patient with the appropriate radiographic abnormalities.

Adult↗
PubMed1995

[Comparison of 99mTc-technegas scintigraphy and high resolution CT in pulmonary emphysema].

This study was undertaken to assess the usefulness of technetium-99m technegas scintigraphy axial images (technegas) compared with high resolution CT (HRCT) in 12 patients with pulmonary emphysema. All patients were male adult and heavy smokers and their mean age was 65. All patients inhaled 505 MBq technegas in several tidal volume breaths in the supine position without breath holding. SPECT imaging was performed by a Picker model Prism 2000. HRCT was performed after technegas. The technegas images showed different degree of changes from areas of heterogeneity to hot spots or defects. In emphysema, HRCT images showed low attenuation areas varying in size and number. In 4 of 12 patients, the degree of abnormal findings on technegas increased according to the degree of abnormal findings on HRCT. In the remaining 8 patients, however, more detailed findings were shown by technegas than by HRCT. There was no patients in which HRCT showed a greater changes than on technegas. HRCT can demonstrate low attenuation areas, even less than 5 mm in diameter. Moreover previous reports showed that aerosol inhalation would also demonstrate the airway disease. Assessment of the degree of involvement revealed by both methods indicated the superiority of technegas over HRCT. We conclude that technegas can represent the ventilation involvement easily more than HRCT in pulmonary emphysema.

Aged↗