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Biomedical subjects

K Hiraishi

Publications and source records attributed to K Hiraishi.

At least 19 recordsLinked to original sources
PubMed1995

The first observation of O2- generation at real time in vivo from non-Kupffer sinusoidal cells in perfused rat liver during acute ethanol intoxication.

Infusion of ethanol or phorbol myristate acetate (PMA) into the perfused rat liver immediately produces O2- which was detected directly by infusion of a Cypridina luciferin analogue, MCLA as a chemiluminescence reagent. The MCLA photon emission was inhibitable by SOD. Generation of O2- in the liver was further verified by nitroblue tetrazolium, formazan precipitate formation. Ethanol-induced O2- generation was unaffected by gadolinium chloride (GdCl3), an inhibitor of kupffer cells, while PMA induced O2- generation was completely abolished by GdCl3. Since PMA is a known stimulator of phagocytic cells including Kupffer cells, the results indicate, for the first time that ethanol stimulates a non-Kupffer cell population, probably liver sinusoid endothelial cell to produce O2-.

Animals↗
PubMed1995

Blueberry juice: preliminary evaluation as an oral contrast agent in gastrointestinal MR imaging.

PURPOSE: To evaluate the use of blueberry juice as an oral contrast agent in magnetic resonance (MR) imaging. MATERIALS AND METHODS: MR imaging of phantoms of blueberry juice and of manganese chloride solutions with different manganese concentrations were conducted. Patient trials were conducted to evaluate manganese blood levels and signal intensity changes on MR images of the abdomen. T1- and T2-weighted conventional spin-echo MR imaging was performed at various field strengths. Six radiologists graded image contrast; signal intensities were calculated. RESULTS: T1 and T2 relaxation curves for blueberry juice and manganese chloride showed similar signal intensity profiles as a function of manganese concentration. Blood concentrations of manganese were unchanged before and after an oral dose of blueberry juice that contained 18 mg of manganese. The results of patient studies indicated that the optimal oral dose of manganese in blueberry juice was 3-4 mg/dL. T1 and T2 shortening were apparent at field strengths of 0.2-1.5 T. CONCLUSION: At appropriate concentrations, blueberry juice has the potential to be an effective oral contrast agent for MR imaging.

Adult↗
PubMed1995

[Evaluation of AMI-25 enhanced MR imaging and enhanced helical CT for liver tumors].

To evaluate the diagnostic capability of superparamagnetic iron oxide enhanced MRI and enhanced helical CT, 17 patients with histologically or clinically diagnosed hepatocellular carcinoma or metastatic liver tumor and a total of 208 nodules were studied. The pulse sequences used were SE 500/20 (T1WI), SE 2000/20 (PDWI) and SE 2000/70 (T2WI). Contrast medium was administrated intravenously for more than 30 minutes at a dose of 10 mumoles Fe/kg. Enhanced MR images were obtained 30-90 minutes after the injection of contrast medium. With helical CT, 133 nodules were detected. With unenhanced MRI, 62 were detected on T1WI, 60 on PDWI and 77 on T2WI. On the other hand, with enhanced MRI, 165 were detected on T1WI, 190 on PDWI and 186 on T2WI. Enhanced MRI revealed the most nodules among these images (P < 0.05), and was especially effective in detecting small nodules less than 10 mm in diameter (P < 0.05). In conclusion, it was considered that superparamagnetic iron oxide enhanced MRI was useful for the detection of hepatic nodules and that the most adequate pulse sequence was PDWI.

Aged↗
PubMed1994

[Contrast enhancement effect of new oral agent (blueberry juice) for upper abdominal MR imaging].

Manganese is known to affect relaxation times. Blueberry is naturally rich in manganese, and oral contrast effect by its squeezed juice (B. J) was expected. At some appropriate concentration of manganese within daily intake level, B. J worked as positive contrast agent on T1WIs and negative one on T2WIs simultaneously without any side effects. The negative effect on T2WIs could reduce ghost artifacts from motion of high intensity structures. B. J improved confirmation of gastroduodenal tract regardless of field strength and could be adapted for fast SE. We introduced a preliminary examination of B. J as an oral contrast agent for upper abdominal MRI.

Abdomen↗
PubMed1994

[MR imaging findings in patients with epilepsy].

We retrospectively examined the MR imaging (MRI) findings in 144 patients with epilepsy (31 with temporal lobe epilepsy and 113 with other epilepsies). 110 cases (76.4%) showed abnormal findings such as spotty lesions in white matter, hippocampal atrophy and/or signal change, ventricular dilatation and/or deformity, developmental lesions, brain tumors and so on. Hippocampal atrophy and/or signal change was shown in 74.1% of temporal lobe epilepsy, a remarkably high percentage (P < 0.01) compared with the other types of epilepsies (18.1%). This finding means that hippocampal lesions may play a large part in the cause of temporal lobe epilepsy. Investigation of the relationship between clinical term and abnormal findings revealed that the longer the clinical term, the larger the number of hippocampal lesions, regardless of whether it is temporal lobe epilepsy or not. Thus hippocampal lesions may occur as a result of hypoxia accompanied with seizure. Therefore we recommend horizontal and/or vertical sections of hippocampus in MR imaging of all patients with epilepsy. Even though MR findings may reflect some secondary lesions, MRI will shed some light on the proper understanding of epilepsy.

Adolescent↗
PubMed1994

[A comparison among 123I-IMP SPECT, EEG and MRI in patients with temporal lobe epilepsy].

N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) single photon emission computed tomography (SPECT), electroencephalography (EEG), and magnetic resonance imaging (MRI) were performed in 19 patients with temporal lobe epilepsy during interictal stage. MRI demonstrated abnormal signal in mesial temporal lobe (hippocampus) in 10 of 19 patients and 123I-IMP SPECT showed a hypoperfusion area in 15 of 19 patients. When compared with EEG and MRI data, disagreement of the affected area was observed in 3 cases. In comparison of EEG and 123I-IMP SPECT data, disagreement of the affected area was observed in 6 cases. Although there were no disagreement in comparison of MRI and 123I-IMP SPECT. We made a reprojection data parallel to the hippocampus in 123I-IMP SPECT. These data demonstrated obviously a hypoperfusion area around the hippocampus. In cases within one month from seizure attack, wide hypoperfusion area was showed on 123I-IMP SPECT in comparison of abnormal signal area on MRI. It could be considered that a reprojection data parallel to the hippocampus was useful to know extent of hypoperfusion area in temporal lobe epilepsy.

Adult↗
PubMed1993

Le(y) antigen expression is correlated with apoptosis (programmed cell death).

Apoptosis (programmed cell death) is a basic physiological process which determines specific patterns of tissue size and shape, and balance of cell number, during morphogenesis, and seems to play an integral role in oncogenic progression. Since dramatic changes of cellular glycosylation pattern are well known to be closely correlated with differentiation, development and oncogenesis, it is likely that similar specific changes are associated with apoptosis. However, this possibility has not been systematically investigated. We therefore carried out histological studies of many tumours and normal tissues for which a high incidence of apoptosis is believed to occur. Sections were stained with monoclonal antibodies (MoAbs) directed to carbohydrate antigens Le(y) and Le(x), proliferating cellular nuclear antigen (PCNA) and Fas (previously claimed to be an apoptosis-inducing antigen). Antibody staining patterns were compared with morphological cell characteristics as revealed by haematoxylin/eosin staining, and DNA fragmentation patterns (a marker of apoptosis) as revealed by 3'-OH nick-end labelling technique. We found that expression of Le(y) (defined by MoAb BM1) is closely correlated with the process of apoptosis, but not with cell proliferation or necrosis. Within Le(y)-positive areas of tissue sections, typical apoptotic morphological changes and DNA fragmentation (as revealed by positive nick-end labelling) were frequently observed in certain loci, although not all Le(y)-positive cells showed such signs of apoptosis. Le(y)-positive areas showed consistent negative staining by MoAb directed to PCNA and negative or weak staining by MoAb directed to Fas antigen, regardless of tissue source. No such trends were observed for Le(x) glycosylation. We conclude that Le(y) expression is a useful phenotypic marker predictive of apoptosis, i.e. some (although not all) Le(y)-positive cells subsequently become apoptotic.

Antibodies, Monoclonal↗
PubMed1993

[A case of benign paraganglioma arising in the middle mediastinum; 201Tl-SPECT for differentiation from malignant tumor].

A case of benign paraganglioma arising in the middle mediastinum was reported. 201Tl SPECT showed high accumulation in tumor on early images at 15 min and reduced on late images at 3 hours after infusion. The patient was a 57 year old female. In the contrast enhanced CT, 3 x 4 cm tumor with intensive enhancement was recognized at the right middle mediastinum. Under the radiological images, the tumor was surgically removed. The pathologic diagnosis was a low atypical nonfunctioning aortico-pulmonary paraganglioma. This report was suggested that 201Tl SPECT was useful for differential diagnosis of benign neurogenic mediastinal neoplasms.

Diagnosis, Differential↗
PubMed1993

[512 x 2048 matrix whole body scintigraphy with laser imaging system].

Although we could acquire a detailed 512 x 2048 matrix whole body scintigraphy, the 512 x 2048 matrix whole body scintigraphy was divided to the upper and lower half of the body, because a many of CRT system displayed only 1024 x 1024 matrix with non interlace mode. We made 12 dots of normal vertical image distance to 0 dot with laser imaging system (Li-10 Konica medical inc.), and we printed these divided whole body images in the four partition of the film. The lead bar phantom (interval from 6 mm to 3 mm) filled with 99mTcO4- was studied by both 512 x 2048 matrix whole body scanning mode and 256 x 1024 whole body scanning mode in the basic study. And the distance between the lead bar phantom and the gamma camera was changed from 10 mm to 100 mm. We studied 41 patients with metastatic bone tumor (14 breast cancer, 7 lung cancer, 7 prostate cancer, 5 others, 6 unknown origin) clinically. However the 512 x 2048 matrix whole body scan was better quality of images than 256 x 1024 matrix whole body scan at 100 mm distance in the basic study. The abnormal uptake of metastatic sites was shown equally in both 512 x 2048 and 256 x 1024 matrix whole body scintigraphy. The 512 x 2048 matrix whole body scan was better quality of images than 256 x 1024 matrix whole body scan in 26 out of 41 patients, equal in 10 out of 41 patients and worse in 3 out of 41 patients. The matrix size of 512 x 2048 matrix whole body scintigraphy (0.98 mm2) was smaller than that of 256 x 1024 matrix whole body scintigraphy (1.95 mm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Bone and Bones↗
PubMed1989

[Urinary material affecting calcium oxalate monohydrate stone formation].

We previously reported that the low molecular and uronic acid-rich fractions in the urine from calcium oxalate stone formers promoted aggregation of calcium oxalate monohydrate seed crystals. In this study, we have demonstrated that lyophilized material of the fractions contains hyaluronic acid as a sole glycosaminoglycans, as well as acidic amino acid-rich proteins and urinary pigment which is supposed to combine with protein. It is known that hyaluronic acid is present in stone matrix, that calcium containing stones contain proteins rich in acidic amino acids, and that the external color of calcium oxalate monohydrate calculi is usually brownish. These facts correspond with our present results. Therefore, it is suggested that the urinary material promotes the calcium oxalate crystal aggregation, sticks the crystals together and is incorporated into the stone.

Calcium Oxalate↗
PubMed1987

Growth hormone-releasing hormone (GHRH)-secreting pancreatic tumor in a patient with multiple endocrine neoplasia type I.

A growth hormone-releasing hormone (GHRH)-secreting pancreatic tumor in a 36-year-old man, who had typical, familial, multiple endocrine neoplasia (MEN) type I with hyperparathyroidism and acromegaly, is described. The resected tumor, weighing 30 g, showed unusual histological features characterized by a meningioma-like arrangement of crescent-shaped cells and contained many cells that reacted with C-terminal specific antibody to GHRH-44 and a few somatostatin-immunoreactive (IR) and calcitonin-IR cells, but no GH-IR cells. A high concentration of IR-GHRH (9.8-13.2 micrograms/g wet weight tissue) with the full molecular size of GHRH-44 was detected in a tumor extract. Electron immunocytochemical study by the protein A-gold method revealed GHRH-IR granules with a mean diameter of 147 nm. After removal of the tumor, the plasma IR-GHRH level became normal (decreasing from 299 to 16.1 pg/ml) and the plasma IR-GH level also decreased, but still remained slightly high (decreasing from 42.4 to 9.6 ng/ml), suggesting the presence of an adenomatous lesion in the hypophysis.

Acromegaly↗
PubMed1987

Serum and urinary uric acid in primary hyperparathyroidism.

Serum and 24-h urinary uric acid were measured in 29 patients with primary hyperparathyroidism pre- and post-operatively. No significant difference was observed. A positive correlation was found between the ratios of urinary calcium/creatinine and urinary uric acid/creatinine pre-operatively but not after surgery. The serum uric acid level showed an increase from the first to the third day post-operatively and returned to normal within a week, but in patients undergoing other urological operations there was no post-operative increase. On a low calcium diet the level of serum uric acid was found to be increased. These findings suggest that primary hyperparathyroidism has some influence on uric acid metabolism.

Adult↗
PubMed1987

[One-stage operation of ureteropelvic junction and ureterovesical junction stricture].

One-stage surgical management for ureteropelvic (UP) and ureterovesical (UV) strictures is reported. A 3-year-old boy with UP and UV strictures on left side, underwent nephrostomy at 4 months old. The plastic operations which were Anderson-Hynes method for UP stricture and submucosal tunnel method with tailoring of dilated ureter for UV stricture were performed at the same time. The post-operative intravesical pyelogram and renal scintigraphy showed the improvement of hydronephrosis. Many authors have described two-stage operations for such cases. Our findings revealed that one-stage operation, carefully preserving the blood supply to the ureter, would be an alternative surgical management for UP and UV strictures.

Child, Preschool↗