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Biomedical subjects

K Hiraishi

Publications and source records attributed to K Hiraishi.

At least 19 recordsLinked to original sources
PubMed2004

Adhesion dependent release of hepatocyte growth factor and interleukin-1 receptor antagonist from human blood granulocytes and monocytes: evidence for the involvement of plasma IgG, complement C3 and beta2 integrin.

OBJECTIVE: Evolving evidence of anti-inflammatory effects is observed in patients with rheumatoid arthritis or ulcerative colitis following periodic adsorptive granulocyte and monocyte (GM) apheresis with a column containing cellulose acetate (CA) beads as apheresis carriers. This study was undertaken to obtain insights into mechanisms of anti-inflammatory actions of adsorptive GM apheresis with CA beads. METHODS: In a series of in-vitro experiments, we investigated the effects of plasma proteins and the leucocytes beta2 integrin (CD18) on granulocyte adsorption to CA beads. RESULTS: Granulocyte adsorption to CA beads required plasma IgG, the complement C3 and was inhibited by an antibody to leucocytes CD18. Further, hepatocyte growth factor (HGF) and interleukin-1 receptor antagonist (IL-1ra) which have strong anti-inflammatory actions were released by granulocytes that adhered to CA beads. CONCLUSIONS: Plasma IgG, C3 derived complement activation fragments and leucocytes CD18 are involved in granulocyte adhesion to CA beads and hence the release of HGF and IL-1ra.

Adsorption↗
PubMed2003

Cellulose acetate beads induce release of interleukin-1 receptor antagonist, but not tumour necrosis factor-alpha or interleukin-1beta in human peripheral blood.

OBJECTIVE: Dramatic improvements in clinical symptoms of rheumatoid arthritis and ulcerative colitis were observed after patients received granulocyte and monocyte adsorptive apheresis with a column containing cellulose acetate (CA) beads as adsorptive carriers. This study was to investigate the effect of CA beads on the generation of anti-inflammatory and pro-inflammatory cytokines in human blood. MATERIALS AND METHODS: We incubated human whole blood with CA beads at 37 degrees C for up to 2 h and measured tumour necrosis factor-alpha (TNF-alpha) interleukin-1beta (IL-1beta) and IL-1 receptor antagonist (IL-1ra) produced by leucocytes. IL-1ra was also measured at the inflow and outflow of a column containing CA beads as leucocyte adsorptive carriers for the treatment of patients with ulcerative colitis. RESULTS: CA beads induced significant release of IL-1ra from leucocytes, but not TNF-alpha or IL-1beta. In contrast, all three cytokines were released when leucocytes were stimulated with lipopolysaccharide. IL-1ra was also markedly elevated in the outflow of the leucocyte apheresis column. CONCLUSIONS: These results indicate that CA beads selectively induce IL-1ra release from leucocytes which should contribute to the anti-inflammatory effect of granulocyte and monocyte adsorptive apheresis with CA beads as apheresis carriers.

Adolescent↗
PubMed2001

Sinusoidal endothelial cell injury by superoxide anion and iron in the Propionibacterium acnes-pretreated and lipopolysaccharide-stimulated rat liver.

AIMS/BACKGROUND: We attempted to measure the generation of superoxide anion, examine its site of release and determine its pathological role in Propionibacterium acnes-lipopolysaccharide-induced liver injury in the rat. METHODS: The P. acnes-pretreated (16 mg/kg i.v.) rat liver was perfused with buffer containing lipopolysaccharide (2.5 microg/ml). Chemiluminescence enhanced with Cypridina luciferin analog, MCLA, and reduction of nitro blue tetrazolium were used for detecting superoxide anion. Leakage of enzymes and release of cytokines into the perfusate, and histological specimens were also examined. RESULTS: Superoxide dismutase-inhibitable chemiluminescence peaked at 30 min of lipopolysaccharide infusion and blue formazan precipitate was histochemically deposited mainly on hepatic macrophages. Purine nucleoside phosphorylase (PNP) activity in the perfusate, as a marker of sinusoidal endothelial cell injury, reached its maximum at 50 min and aspartate aminotransferase (AST) activity, as a marker of hepatocyte injury, reached a plateau at 90 min. Simultaneous treatment with superoxide dismutase and deferoxamine mesylate significantly suppressed the leakage of PNP and AST. Release of tumor necrosis factor-alpha and growth-related oncogene/cytokine-induced neutrophil chemoattractant-1 lagged behind PNP leakage. Light microscopy showed destruction of the sinusoids followed by hepatocyte necrosis. Electron microscopy revealed adherence of hepatic macrophages to sinusoidal endothelial cells. CONCLUSION: These results indicate that superoxide anion released from hepatic macrophages may induce sinusoidal endothelial cell injury via interaction with iron in the P. acnes-lipopolysaccharide-treated liver.

Animals↗
PubMed2001

Genetics of cognition: outline of a collaborative twin study.

A multidisciplinary collaborative study examining cognition in a large sample of twins is outlined. A common experimental protocol and design is used in The Netherlands, Australia and Japan to measure cognitive ability using traditional IQ measures (i.e., psychometric IQ), processing speed (e.g., reaction time [RT] and inspection time [IT]), and working memory (e.g., spatial span, delayed response [DR] performance). The main aim is to investigate the genetic covariation among these cognitive phenotypes in order to use the correlated biological markers in future linkage and association analyses to detect quantitative-trait loci (QTLs). We outline the study and methodology, and report results from our preliminary analyses that examines the heritability of processing speed and working memory indices, and their phenotypic correlation with IQ. Heritability of Full Scale IQ was 87% in the Netherlands, 83% in Australia, and 71% in Japan. Heritability estimates for processing speed and working memory indices ranged from 33-64%. Associations of IQ with RT and IT (-0.28 to -0.36) replicated previous findings with those of higher cognitive ability showing faster speed of processing. Similarly, significant correlations were indicated between IQ and the spatial span working memory task (storage [0.31], executive processing [0.37]) and the DR working memory task (0.25), with those of higher cognitive ability showing better memory performance. These analyses establish the heritability of the processing speed and working memory measures to be used in our collaborative twin study of cognition, and support the findings that individual differences in processing speed and working memory may underlie individual differences in psychometric IQ.

Adolescent↗
PubMed2000

[Novel extracorporeal granulocyte apheresis column inhibits myocardial reperfusion injury: future clinical applications].

OBJECTIVES: Leukocyte infiltration is very important in myocardial ischemia/reperfusion injury. A new extracorporeal circulation therapy using a granulocyte-apheresis column (G-1) has recently been proved to be effective and safe in patients with rheumatoid arthritis and with ulcerative colitis. This study investigated whether this therapy would reduce myocardial ischemia/reperfusion injury. METHODS: Rabbits were subjected to 30 min ischemia followed by 180 min reperfusion with no treatment (control group: n = 12); or treated with extracorporeal blood circulation (2 ml/min) passing through the G-1 (G-1 group: n = 12), or sham column (sham group: n = 12). Infarct size was determined by tetrazolium staining and expressed as a percentage of the area at risk. RESULTS: Infarct size in the G-1 group (15.9 +/- 3.4%) was significantly (p < 0.01) smaller than in the control (34.7 +/- 3.9%) and sham (35.2 +/- 4.1%) groups. Granulocyte emigration into the ischemic myocardium assessed by histopathological score was significantly (p < 0.01) less in the G-1 group (0.58 +/- 0.17) than in the sham group (1.42 +/- 0.26). There was a significant (r = 0.78, p < 0.0001) positive correlation between this score and infarct size. Flow cytometry showed alterations in the adhesion molecule expression on granulocytes during the passage through the G-1, but not sham, columns as a low L-selectin and high Mac-1 form, which is associated with the inability to home to the inflamed site. CONCLUSIONS: Extracorporeal circulation with the G-1 column, a newly-developed clinically applicable therapy, appears to reduce infarct size at least in part by limiting the emigration capacity of granulocytes into the ischemic myocardium.

Animals↗
PubMed1997

[Long-term follow-up of the Le Duc-Camey antireflux technique].

BACKGROUND: An effective ureteroileal reimplantation without reflux and obstruction is indispensable for lower urinary reconstruction or diversion using an ileal segment. Based on our earlier experience of afferent nipple valve malfunction of the Kock pouch, we performed Le Duc-Camey antireflux ureteroileal implantation. In the present study, we evaluated the long-term outcome of the Le Duc-Camey technique on the upper urinary tract in patients with a postoperative observation period of 2 years or more. PATIENTS AND METHODS: From 1989 to 1994, 39 patients (73 ureters) underwent Le Duc-Camey technique for prevention of reflux of a Kock pouch. In 28 patients the ileal reservoir was connected to the skin for cutaneous urinary diversion, and in 11 it was connected to the urethra for lower urinary reconstruction. The ureters were implanted into the reservoir through the anterior wall window of the reservoir. In most patients, excretory urography (DIP) was performed once a year after the first year. Retrograde cystography or voiding cystourethrography was performed within 12 months postoperatively. After the first year, retrograde study was performed once during the follow-up period in the majority of the patients. The mean follow-up period was 44.8 months (range 24-71 months). RESULTS: There was no urinary tract dilatation in 68 renal units (93.1%), while slight dilatation was noted in 3 (4.1%), moderate dilatation in 1 (1.4%), and marked dilatation due to stenosis of ureteroileal anastomosis in 1 (1.4%). Retrograde studies revealed absence of reflux in all patients. Another complication that related to this procedure was not observed in any patients. CONCLUSION: We conclude that Le Duc-Camey technique is effective in reflux prevention and protection of the upper urinary tract, and recommend it for use with detubularized ileal reservoir.

Adult↗
PubMed1996

[The usefulness of three-dimensional helical CT for the detection of abnormalities of the auditory ossicles].

To evaluate the usefulness of three-dimensional (3D) helical CT for the detection of abnormalities of the auditory ossicles, 3D helical CT of the middle ear was performed in seven patients with hearing disorder. It revealed that 4 patients had congenital deficiency of the auditory ossicles, 2 patients with chronic otitis media had shortening of the incus and one patient with head injury had doubtful fracture of the incus. This study indicated that 3D helical CT of the middle ear can represent the auditory ossicles objectively and can offer detailed diagnosis.

Adolescent↗
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↗