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Biomedical subjects

H Matsuda

Publications and source records attributed to H Matsuda.

At least 829 records · Page 46Linked to original sources
PubMed1996

[Noninvasive quantitative measurements of regional cerebral blood flow using technetium-99m-L, L-ECD SPECT activated with acetazolamide].

To evaluate noninvasive regional cerebral blood flow (CBF) measurements using technetium-99m-L, L-ethyl cysteinate dimer (99mTc-ECD), radionuclide angiography, resting- and acetazolamide-activating-SPECT studies were performed during about one hour. Forty-four cases with diagnosis of cerebral ischemic disorders were studied. For 36 cases (Group "Acz"), radionuclide angiography was performed immediately after intravenous bolus injection of 300 MBq of 99mTc-ECD, followed by the consecutive SPECT studies. In the midst of the first SPECT study, acetazolamide was administered. Just after the completion of the first SPECT study, another 300 MBq of 99mTc-ECD was added and the second SPECT study was started. For the remaining 8 cases (Group "Placebo"), physiological saline was administered instead of acetazolamide. Quantitative flow-mapping image was calculated from the qualitative SPECT image by the application of Patlak plot graphical analysis and Lassen's correction. Group "Placebo" showed no increase of mean CBF (mCBF) between the resting- and the placebo-challenged-SPECT image (2nd mCBF/1st mCBF; 98 +/- 5%). Group "Acz" showed 124 +/- 15% increase of mCBF under acetazolamide activation. By use of these quantitative flow-mapping images, acetazolamide-activated CBF increase was recognized clearly and easily. This noninvasive method is easy to perform and may be helpful to measure cerebral perfusion changes in the acetazolamide test.

Acetazolamide↗
PubMed1996

[Pharmacokinetic and clinical evaluation of azithromycin in pediatric infections].

Azithromycin (AZM) was studied for its concentrations in plasma and urine, efficacy and safety. 1. Plasma and urine samples were collected from one patient diagnosed as having Mycoplasma pneumonia for drug level determination. The drug was given once daily at 9.7 mg/kg body weight for three days. The drug concentrations in plasma was 0.149 microgram/ml in 12 hours after the start of the treatment, and 0.095 microgram/ml at the point of 24 hours after the end of the treatment. Urinary recovery rate up to 72 hours post-dosing was 6.39%. 2. The effectiveness of AZM was assessed in 19 patients with following diagnoses: pharyngitis in two patients, bronchitis in four, pneumonia in seven and Mycoplasma pneumonia in six. The drug was rated "excellent" in 11, "good" in seven, "poor" in one, resulting in an efficacy rate of 94.7%. 3. AZM eradicated two strains of Streptococcus pyogenes and Streptococcus pneumoniae identified in patients. 4. The AZM MIC's were 0.39 microgram/ml against Staphylococcus aureus, 0.20 microgram/ml against S. pneumoniae, < or = 0.0008 microgram/ml against Mycoplasma pneumoniae. 5. One patient complained of mild diarrhea, while another showed a slight increase in eosinophils, suggesting an abnormal laboratory change. In conclusion, AZM was found useful in treatment of pediatric infections.

Adolescent↗
PubMed1996

[A case of ventricular septal defect closure in patient with cytomegalo virus hepatitis].

Cytomegalovirus (CMV) infection has been reported to cause serious event in nonimmunocompromised patients after major surgery. Particularly in active case, the indication of surgical intervention is a difficult issue. A 7-months-old boy with ventricular septaldefect (VSD) has been diagnosed with CMV hepatitis. As his heart failure was not controlled with medication, he underwent closure of VSD at 9 months of age while CMV was still detected in the urine and serum by polymerase chain reaction method. During post operative course, he was treated with ganciclovir and intravenous CMV hyperimmune grobiln, and CMV in the serum became negative and he develops no aggravation of the CMV infection postoperatively.

Antiviral Agents↗
PubMed1996

[Utility of bolus dynamic CT for the detection of hypervascular malignant hepatic tumors: mainly referring to the comparison with delayed phase contrast-enhanced CT].

In order to analyze the usefulness of dynamic contrast-enhanced CT, 84 patients who had hepatocellular carcinoma or suspected hypervascular metastases were studied with conventional incremental dynamic CT (CID-CT) or double helical CT (DH-CT). Delayed phase contrast-enhanced CT studies were consecutively performed in all patients. Thirty-six of 84 patients had malignant hepatic neoplasms; six had hepatocellular carcinoma and 30 had metastatic tumors. At first, the detectability of hepatic lesions was evaluated with bolus dynamic CT and delayed phase CT. Dynamic CT has detected more lesions than delayed CT. Some hepatic lesions described as isodensity were missed on CID-CT. Therefore, delayed phase CT cannot be eliminated when CID-CT is performed. Secondly, hepatic lesion detectability with CID-CT was compared with that of DH-CT. DH-CT did not miss the hepatic lesions picked up by delayed phase CT and was expected to provide excellent detectability of hypervascular hepatic neoplasms. In addition, first helical CT showed most hepatic lesions as areas of obvious hyperdensity, while CID-CT did not show their correct vascularities. So-called hypervascular hepatic tumors, however, were not always hypervascular and were demonstrated as areas of iso-hypodensity even on initial helical scanning. Second helical CT was useful to detect these so-called hypervascular, but actually hypovascular lesions. In conclusion, dynamic CT was helpful in detecting hypervascular hepatic malignant neoplasms, and DH-CT was more accurate than CID-CT for the detection of hepatic lesions and the evaluation of vascular lesion.

Adult↗
PubMed1996

Protein phylogenetic inference using maximum likelihood with a genetic algorithm.

This paper presents a method to construct phylogenetic trees from amino acid sequences. Our method uses a maximum likelihood approach which gives a confidence score for each possible alternative tree. Based on this approach, we developed a genetic algorithm for exploring the best score tree: randomly generated alternative trees are rearranged so that their scores are improved by utilizing crossover and mutation operators. In a test of our algorithm on a data set of EF-1 alpha sequences, we found that the performance of our algorithm is comparable to that of other tree-construction methods.

Algorithms↗
PubMed1995

Production of chronic compression of the cauda equina in rats for use in studies of lumbar spinal canal stenosis.

STUDY DESIGN: The pathophysiology of lumbar spinal canal stenosis was analyzed with a new model in rats. OBJECTIVES: To produce chronic compression of the cauda equina in rats for analysis of the pathophysiology of lumbar spinal canal stenosis. SUMMARY OF BACKGROUND DATA: Models of compression to date have involved acute or subacute compression. A model of chronic compression has not been available. METHODS: A stainless steel wire fastened around the spine at L5 in 3-week-old rats, with a plate inserted against the ventral aspect of the vertebra to protect it from the wire. as the rats grew, the wire cut into the spinal canal. One year after the operation, canal stenosis was present without paralysis of the back limbs. RESULTS: Stenosis seen in sagittal sections, as a percentage of the original width, was 51.6 +/- 6.2% (mean +/- standard deviation). In histologic analysis of the region near the wire, findings included axonal degeneration, demyelination, vacuolar degeneration of the nerve fibers, and narrowing the intradural blood vessels with a decrease in their number. Cephalad and caudad to the wire, congested intradural blood vessels, degenerative foci near these congested vessels, fibrosis around these foci, congested epidural vessels, and fibrosis around these vessels were observed. During electrophysiologic analysis (six rats with stenosis), the conduction velocity of the cauda equina was found to be delayed. CONCLUSIONS: The histologic and electrophysiologic findings in this animal model were similar to findings in human subjects, so rats prepared in this way should be useful for study of chronic compression of the cauda equina.

Animals↗
PubMed1995

Nerve growth factor prevents apoptosis of rat peritoneal mast cells through the trk proto-oncogene receptor.

We investigated the inhibitory activity of nerve growth factor (NGF) on apoptosis of rat peritoneal mast cells (PMCs) and compared it with that of recombinant stem cell factor (rSCF), which is a mast cell growth factor. When PMCs were incubated up to 72 hours in the presence of control medium, internucleosomal fragmentation of DNA indicating apoptosis was detected by agarose gel electrophoresis and flow cytometry. The aged PMCs showed morphological changes typical for apoptosis, such as chromatin condensation and loss of microvilli of the cell membrane. Addition of NGF or rSCF prevented development of the characteristic DNA fragmentation and decreased the proportion of apoptotic cells with low DNA content values in a dose-dependent manner. Polyclonal antibody to NGF completely abolished the inhibitory activity of NGF but not of rSCF. NGF-induced PMCs were in the G0/G1 phase of the cell cycle, but rSCF transited them from the G0/G1 phase to the S/G2M phase, suggesting that NGF, unlike rSCF, may have no proliferation activity to PMCs. By flow cytometric analysis with antibodies to NGF receptors p75LNGFR and p140trk, we defined that PMCs expressed p140trk but not p75LNGFR. Addition of herbimycin A or K-252a, tyrosine kinase inhibitors, to NGF resulted in blockage of the NGF-induced p140trk phosphorylation and restriction of the inhibitory activity of NGF on apoptosis of PMCs. These results indicated that NGF suppressed apoptosis of rat PMCs through the p140trk tyrosine phosphorylation and possessed no proliferative activity. Thus, NGF may act as a key factor to promote survival of connective tissue-type mast cells.

Animals↗
PubMed1995

Evidence that graft coronary arteriosclerosis begins in the early phase after transplantation and progresses without chronic immunoreaction. Histopathological analysis using a retransplantation model.

The histopathological features of chronic rejection and its initiation were assessed using rat heterotopic heart transplantation and retransplantation models. Fully allogeneic or minor, non-MHC antigen-mismatch heart grafts transplanted into recipient rats treated with a short course of FK506 showed long-term survival but developed graft atherosclerosis after 40 days posttransplantation. Retransplantation of allografts back into the original donor strain did not prevent graft atherosclerosis if the grafts had resided in the primary recipient for up to 5 days; residence in the primary allogeneic recipient for less than 4 days did not result in graft atherosclerosis in the secondary recipient. Short-course administration of FK506 did not affect the production of these changes. Graft coronary arteriosclerosis begins between 3 and 5 days posttransplantation and progresses without continuous allogeneic immunological drive. The present findings will provide a new means by which to approach the analysis of development of chronic allograft rejection.

Animals↗
PubMed1995

Supplement of nitric oxide attenuates neutrophil-mediated reperfusion injury.

BACKGROUND: Nitric oxide (NO) derived from the endothelial cell has been identified as a constitutive chemical mediator that regulates the function of the endothelial cell in association with neutrophil (PMN) adhesion and activation. However, its role in the pathogenesis of myocardial reperfusion injury is not clear. METHODS AND RESULTS: Fifteen isolated rat hearts were perfused with modified Krebs-Henseleit solution and subjected to 20 minutes of global and normothermic ischemia. Then the hearts were reperfused for 45 minutes with different protocols: the control (C) group was reperfused without PMNs, the P group was reperfused with PMNs, and the N group was reperfused with PMNs and nitroprusside (10(-5) mol/L). The ozone chemiluminescence method was used for direct measurement of NO in the coronary effluent during reperfusion. NO in the coronary effluent in the C group decreased at reperfusion after normoxic perfusion, and this decrease in NO continued for the first 15 minutes of reperfusion. Percentage recovery of left ventricular developed pressure and coronary flow was significantly lower in the P group than that in the N group. Also, the N group had a significantly lesser Luminol-elicited chemiluminescence of the coronary effluent and ratio of PMN adherence to myocardial vasculature compared with the P group. CONCLUSIONS: This study demonstrated directly the decrease in NO production during reperfusion and showed that supplement of NO with NO donor attenuated the injury in which PMNs were involved. The results suggest that NO plays a significant role in reperfusion injury and that supplement of NO during reperfusion appears to be useful to attenuate this injury.

Animals↗
PubMed1995

Efficiency of in vivo gene transfection into transplanted rat heart by coronary infusion of HVJ liposome.

BACKGROUND: Current methods of in vivo gene transfer into myocardium are limited by low efficiency. To improve in vivo gene transfer, a gene transfer method using hemagglutinating virus of Japan (HVJ) as a viral vector can be an alternative. METHODS AND RESULTS: In vivo gene transfection of FITC-labeled oligonucleotide (F-ODN) and cDNA of beta-galactosidase (beta-gal) was examined with use of the HVJ liposome (H group) or without it (C group). In the H group, F-ODN or cDNA of beta-gal were complexed with liposomes, DNA binding nuclear protein (HMG1), and the viral protein coat of HVJ. After the harvest of donor rat hearts arrested by cardioplegia, the coronary artery was infused with the liposome gene complex. The hearts were transplanted into the abdomens of recipient rats and harvested 3 days after transplantation. Regarding F-ODN, the H group clearly showed FITC staining in the nuclei of the myocytes and endothelial cells in almost all layers of the myocardium as compared with the C group. Regarding the expression of beta-gal, the H group showed a clear expression of beta-gal on myocytes, whereas very low expression of beta-gal was seen in the C group. CONCLUSIONS: The donor hearts were transfected with F-ODN and beta-gal gene in almost all layers of the myocardium as a result of coronary infusion of the HVJ liposome during cardioplegic arrest. Our method is seen as a novel in vivo gene transfer technique for the heart and may provide a new tool for both research and therapy of heart transplantation.

Animals↗
PubMed1995

Nitric oxide induces c-fos gene expression via cyclic AMP response element binding protein (CREB) phosphorylation in rat retinal pigment epithelium.

We have examined whether nitric oxide (NO) induces the expression of c-fos proto-oncogene and the phosphorylation of cyclic AMP response element binding protein (CREB) in the rat retina. NO donor sodium nitroprusside (SNP) was injected into the vitreal cavity of the eye, and the retina and retinal pigment epithelium (RPE) was analysed by in situ hybridization using single-stranded RNA probes for c-fos transcripts and by immunocytochemistry using an anti-phospho Ser-133 antibody 20 min after the injection of SNP, phosphorylated-CREB immunoreactivity was found in RPE cells and weakly in some cells of the INL. Forty-five min after the SNP injection, the expression of c-fos mRNA was detected in the RPE. These results suggested that NO induced the c-fos expression via the phosphorylation of CREB in RPE cells, as it has been demonstrated in PC12 cells that the transcription of c-fos gene was activated by the CREB phosphorylation.

Activating Transcription Factor 2↗
PubMed1995

Generation of nitric oxide as a rejection marker in rat pancreas transplantation.

In clinical pancreas transplantation, no reliable marker for the early diagnosis of acute rejection has been reported. This is one reason why the graft survival rate of pancreas transplantation alone is much lower than that of other organs, such as hearts, livers, and kidneys. We designed an experiment to investigate acute rejection of pancreas allografts in hyperglycemic rats by measurement of blood glucose levels and nitric oxide (NO) products (nitrite plus nitrate, and nitrosyl hemoglobin). As recipients, Lewis rats were rendered hyperglycemic by intravenous injection of streptozotocin before transplantation. F344 rats were used as donors of pancreas allografts. Lewis rats were also used as donors of syngeneic pancreas grafts. After transplantation, the blood glucose level returned to a normal level and rejection was defined as the recurrence of hyperglycemia. The mean survival time of pancreas allografts was 14 +/- 0.7 days. The plasma level of nitrite plus nitrate in allografted rats peaked on postoperative day 7. Electron spin resonance spectra of NO bound to hemoglobin were detected in the blood from allografted rats with a peak on postoperative day 7, whereas NO bound to hemoglobin was not detected in the blood from recipients of syngeneic grafts at any sampling time. The results show that NO was synthesized in the earlier period than the elevation of the blood glucose level during rejection after pancreas transplantation in rats.

Acute Disease↗
PubMed1995

Cell-cycle-dependent invasion in vitro by rat ascites hepatoma cells.

The relationship between cell cycle and experimental metastasis of tumor cells in vivo has been investigated, but it remains to be elucidate which step of metastasis, or whether tumor-cell invasion in particular, depends on cell cycle. We previously reported an in vitro cell-monolayer invasion (transcellular migration) assay system, in which the invasive capacity of tumor cells is measured by counting tumor cells penetrating beneath a cultured mesothelial cell monolayer after tumor-cell seeding. Using our invasion assay system, the relationship between invasive capacity and cell-cycle distribution of MMI cells, a highly invasive clone of rat ascites hepatoma AHI30, was investigated. Invasive capacity of aphidicolin- or hydroxyurea-synchronized tumor cells enriched in G1/S-early S-phase cells was about 2 to 6 times higher than that of asynchronous cells. According to time-course experiments to examine the relationship between invasive capacity and the size of fraction of cells in each phase after release from an aphidicolin or a nocodazole block, it was suggested that MMI cells are most invasive in G1/S-S phase. Phagokinetic assay using colloidal gold particles showed that one possible reason for the enhanced invasiveness might be the increased cell motility in such phases, as suggested by the in vitro invasion assay.

Animals↗
PubMed1995

Different modes of sensory neuropeptides and nitric oxide involvement in relaxation of guinea-pig vessels.

This study investigated involvement of calcitonin-gene-related peptide (CGRP), substance P (SP) and nitric oxide (NO) in transmural nerve stimulation (TNS)-induced non-adrenergic, non-cholinergic (NANC) relaxation in isolated guinea pig anterior mesenteric artery (AMA) and posterior caval vein (PCV). Effects of cyclo-oxygenase-generated eicosanoids were blocked with indomethacin (10(-5) M) and so were adrenergic and cholinergic responses with phentolamine (3 x 10(-6) M), propranolol (10(-6) M) and atropine (10(-6) M). In both vessels precontracted by U-46619, TNS induced relaxation, which was almost completely abolished by capsaicin pretreatment (10(-6) M, 15 minutes). In AMA, a CGRP1 receptor antagonist (human CGRP8-37, 10(-5) M) significantly attenuated the relaxation, while did both human CGRP8-37 (10(-5) M) and neurokinin-1 receptor antagonists (spantide, 2 x 10(-5) M and FK888, 3 x 10(-6) M) in PCV. NG-nitro-L-arginine methyl ester (10(-4) M) did not significantly attenuate either the NANC-or CGRP-induced relaxation in AMA. However, it significantly did attenuate both the NANC-and SP-induced relaxation, and it also considerably attenuated CGRP-induced relaxation although insignificantly, in PCV. Thus, CGRP could be significantly responsible for the NO-independent NANC relaxation in AMA, whereas both CGRP and SP could additionally relax PCV in a NO-dependent manner.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1995

Relationship of the ipsilateral rotation in night period and striatal dopamine content reduction in unilateral nigrostriatal 6-OHDA lesioned rats.

In order to discriminate well-lesioned rats after unilateral microinjection of 6-OHDA into the nigrostriatal dopamine system, we measured the spontaneous rotation in the night period and calculated the rate of ipsilateral rotation movement. The rate of ipsilateral rotation movement increased along with the total rotation movement. The rats with over 95% of ipsilateral rotation kept the rate relatively constant for 4 weeks after 6-OHDA lesion and showed a significant increase of contralateral rotation (253.2 +/- 37.9) as compared with the rat that had lower than 95% ipsilateral rotation (3.6 +/- 1.4) after the injection of apomorphine (0.25 mg/kg, s.c.). The reduction percentages of striatal DA contents in animals with unilateral rotation over 95% and under 95% to the lesioned side were 97.8 +/- 0.6% and 59.6 +/- 5.8% (P < 0.001), respectively. The rats with over 90% reduction of striatal DA levels corresponded nicely to rats with 95% ipsilateral rotation among rats injected with apomorphine. These results suggested that the evaluation of ipsilateral rotation, taken the level of 95% rotation to the lesioned side as a standard, was able to discriminate well-lesioned rats without apomorphine treatment after unilateral nigrostriatal 6-OHDA application.

Animals↗