Biomedical subjects

T Yoshimoto

Publications and source records attributed to T Yoshimoto.

At least 91 records · Page 5Linked to original sources

PubMed2001

[Development of new hydrophilic catheter kit for self-catheterization: study in pediatric cases].

PURPOSE: To increase the management of self-catheterization in children of school age, a catheter kit consisting of hydrophilic catheter and a packet containing sterilized water was developed. We evaluated the lubricating characteristic and clinical efficacy of this new catheter kit. MATERIALS AND METHODS: The catheter kit used in the study was a pocket-size plastic container in which a polyurethane catheter coated with hydrophilic polymer and a packet containing sterilized water were packed in combination. The lubricating characteristic of catheter was assessed by the measurement of friction value. For clinical assessment, male children aged over 6 years old who were doing self-catheterization at 17 medical institutions nationwide were selected as the subjects. The 32 children who had given informed consent (mean age: 11.6 years old) were asked to use the catheter kit continuously for 1 week. The results were investigated by a questionnaire survey in which the assessment before and after the use was expressed in scores. At the same time, urinalysis and urine culture were examined. RESULTS: The friction value of hydrophilic catheter was equivalent to or less than that observed by applying a lubricant to the conventional catheter. The comparison of conventional catheter with the kit indicated significantly higher scores (assessment in 5 grades expressed in scores) for the portability and operability of the kit. Though there was no significant difference in the ease of insertion between the two catheters, there were several comments that the kit got stuck in the urethra when it was withdrawn. The global assessment gave a significantly higher score to the kit and 30 (94%) of the 32 children wanted to use the kit continuously. No increase in hematuria which caused a clinical problem or no new apparent urinary tract infection occurred after the use of the kit. CONCLUSIONS: Compared with the conventional catheter, the hydrophilic catheter kit highly satisfied a large number of children at the time of self-catheterization. Depending on the condition of children, the kit is considered useful for continued self-catheterization for a long term.

Child↗

PubMed2001

Brain single-photon emission CT studies using 99mTc-HMPAO and 99mTc-ECD early after recanalization by local intraarterial thrombolysis in patients with acute embolic middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: The brain distribution of 9mTc-hexamethylpropyleneamine oxime (HMPAO) correlates with regional brain perfusion, whereas 99mTc-ethyl cysteinate dimer (ECD) reflects not only perfusion but also the metabolic status of brain tissue. We compared 99mTc-ECD single-photon emission CT (SPECT) with 99mTc-HMPAO SPECT early after recanalization by local intraarterial thrombolysis (LIT) in patients with acute embolic middle cerebral artery occlusion. We also assessed the predictive value of 99mTc-HMPAO and 99mTc-ECD SPECT for the development of ischemic brain damage. METHODS: 99mTc-HMPAO and consecutive 99mTc-ECD SPECT studies were performed in 15 patients within 3 hours of LIT. The two SPECT studies were obtained independently using a subtraction technique. SPECT evaluation was performed using semiquantitative region-of-interest analysis. Noninfarction, infarction, and hemorrhage were identified by follow-up CT or MR imaging. RESULTS: Forty-five lesions were identified (21 noninfarctions, 19 infarctions, and five hemorrhages). Regardless of 99mTc-HMPAO SPECT findings, lesions showing isoactivity (count rate densities of 0.9 to 1.1 as compared with the contralateral side) on 99mTc-ECD SPECT were salvaged. Lesions with hypoactivity (values < 0.9) on 99mTc-ECD SPECT developed irreversible brain damage. Hemorrhage appeared in lesions with both hyperactivity (values > 1.1) on 99mTc-HMPAO SPECT and hypoactivity on 99mTc-ECD SPECT. CONCLUSION: The brain distribution of 99mTc-ECD in a reperfused area identified by 99mTc-HMPAO SPECT early after recanalization of acute ischemic stroke is dependent on cerebral tissue viability. By combining 99mTc-ECD and 99mTc-HMPAO SPECT, performed within the first few hours of LIT, it is possible to identify patients at risk for hemorrhagic transformation reliably.

Aged↗

PubMed2001

The application of minisatellite variant repeat mapping by PCR (MVR-PCR) in a paternity case showing false exclusion due to STR mutation.

A boy and a girl with their mother brought a paternity suit against an alleged but deceased father. We tested six conventional genetic markers, the AmpliType PM+ DQA1 and twelve STR loci the children and mother together with the alleged paternal grandparents. We also DNA typed the bloodstain found later in the alleged father's medical record. Only the result at D3S1358 in a nineplex STR system excluded the alleged father from parentage of the boy, whereas all markers were inclusive for the girl. Accordingly, we performed sequence analysis at D3S1358 to confirm the presence of a paternal exclusion or mutation. The sequence analysis indicated that the boy's allele 17 could have originated from either of the alleged father's allele 16 or 18 by a single-step mutation associated with slippage mutation in STR loci. We carried out minisatellite variant repeat mapping by PCR (MVR-PCR) at loci D1S8 (MS32) and D7S21 (MS31A) and mapped allele haplotypes of all individuals except the deceased alleged father. The MVR-PCR analysis showed that the boy has no inconsistency with the relationship between the alleged grandparents, and was very effective at increasing the paternity index (PI) value. We conclude that there is biological relationship between not only the girl but also the boy and the alleged father.

Adult↗

PubMed2001

Dynamic and static 99mTc-ECD SPECT imaging of subacute cerebral infarction: comparison with 133Xe SPECT.

UNLABELLED: 99mTc-ethylcysteinate dimer (99mTc-ECD) SPECT imaging reportedly fails to show reflow hyperemia in patients with subacute stroke. This study attempts to determine the clinical usefulness of dynamic 99mTc-ECD SPECT in evaluating regional blood flow in subacute cerebral infarction and the kinetic behavior of 99mTc-ECD in infarct areas. METHODS: 133Xe and consecutive dynamic and static 99mTc-ECD SPECT studies were performed on 24 patients with cortical infarction in the middle cerebral artery territory 13-15 d after the onset of a stroke. Image contrast between infarct and contralateral control areas on 99mTc-ECD tomograms (ECD uptake ratio) was compared with that on cerebral blood flow (CBF) images obtained using 133Xe inhalation (CBF ratio). RESULTS: In all cases, ECD uptake ratios from static images were lower than CBF ratios. This tendency was obvious when CBF in the infarct area increased above the normal control value, and no significant correlation was found between ECD uptake ratios from static images and CBF ratios. Only in the infarct areas with CBF below the normal control value, however, was a significant correlation between the two maintained (r = 0.795; P = 0.0011). A very strong correlation was found between CBF ratios and ECD uptake ratios on both the first dynamic scan (36 s after injection) (r = 0.991; P < 0.0001) and the second dynamic scan (72 s after injection) (r = 0.945; P < 0.0001). The correlation coefficient decreased in a time-dependent manner, with no significant correlation observed after the fourth dynamic scan (144 s after injection). On the other hand, significant correlations were observed on all dynamic scans only in the infarct areas with CBF below the control value. CONCLUSION: Super-early images of dynamic 99mTc-ECD SPECT provide a close imaging contrast with CBF and reveal reflow hyperemia in areas with irreversible changes produced by subacute stroke, which static 99mTc-ECD SPECT images fail to show. Decreased retention of the tracer in the infarct areas with hyperperfusion causes an underestimation of CBF on static 99mTc-ECD SPECT images. Given these results, we believe that dynamic 99mTc-ECD SPECT is an effective clinical tool to evaluate regional blood flow in subacute cerebral infarction.

Adult↗

PubMed2001

[A case of potassium-sensitive periodic paralysis with cardiac dysrhythmia controlled with imipramine and acetazolamide].

We report a patient with potassium-sensitive periodic paralysis with cardiac dysrhythmia. The patient was a 16-year-old man. He presented with asymptomatic ventricular dysrhythmia and periodic paralysis when he was 6 and 12 years old, respectively. Physical examination revealed slight dysmorphic features such as hypoplastic mandible, low-set ears and clinodactyly. Through an exercise test, a potassium tolerance test and a muscle biopsy, his illness was diagnosed as potassium-sensitive periodic paralysis with cardiac dysrhythmia. For the treatment of his episodic paralysis, we started acetazolamide, which improved both the incidence and the severity of paralysis. However, the incidence of cardiac dysrhythmia was increased after the use of acetazolamide. Routine anti-arrhythmic drugs such as lidocaine failed to control his ventricular dysrhythmia. Only imipramine showed its efficacy by improving the degree and the incidence of cardiac dysrhythmia without aggravating periodic paralysis. This syndrome is relatively rare and there have been no standard protocols for the treatment. We propose the combination of acetazolamide and imipramine as the first choice for this clinical entity. We also discussed the efficacy of the exercise test. It enabled us to confirm the diagnosis of periodic paralysis safely and easily by recording the change of compound muscle action potential amplitudes.

Acetazolamide↗

PubMed2001

A new triplex STR system without irregular alleles by silver staining and its potential application to forensic analysis.

In order to increase the discriminating power of DNA analysis in forensic science, we devised a new triplex STR system using three novel STR loci we previously reported, D14S299 (wglc5), D15S233 (wgldl), and 9q2h2. We designated this system a CDH triplex system. The CDH triplex system showed a high discriminating power, especially in Caucasians. This system is composed of three STR loci showing only regular tetranucleotide repeat alleles. We easily enlarged the databases mainly of Japanese, using this system, and compared them with those of Caucasian and Chinese. This CDH triplex system therefore appears to be useful for forensic practice.

Alleles↗

PubMed2001

[Distal anterior inferior cerebellar artery aneurysms: report of three cases and literature review].

Aneurysm at the distal portion of the anterior inferior cerebellar artery (AICA) is uncommon and only 55 cases have been documented in the literature. Here we report an additional three cases with review of the literature. All three patients presented with subarachnoid hemorrhage. The ruptured aneurysms were located at the meatal loop of the AICA in all three patients and one patient had another unruptured aneurysm at the lateral branch distal to the meatal loop. Two patients underwent surgical trapping of the aneurysms, and the other patient was treated with endovascular coiling because of poor clinical condition. Increase of hearing disturbance was found in two patients who underwent surgery or endovascular coiling, respectively. Clinical features and treatment of these rare lesions are discussed with reference to the 7th and 8th nerve impairments as preoperative symptoms and postoperative complications.

Adult↗

PubMed2001

[Primary aldosteronism presented with intracranial hemorrhage].

Although primary aldosteronism (PA) has been reported as a relatively benign form of hypertension and is associated with low incidence of vascular complications, recent reports indicate that PA complicated by cerebral vascular accidents is not rare. The authors reported here that a 57-year-old man was diagnosed as a case of PA 4 years after initial treatment of intracerebral hemorrhage (ICH) and hypertension. The patient was transferred to our department for further management of his left hemiplegia and hypertension after surgical treatment for a putaminal ICH at the age of 53. During the first 2 years of follow-up, he did well except for an episode of transient motor weakness. Diastolic hypertension was moderately good, controlled by calcium antagonists and ACE inhibitors. Laboratory data was normal, and the serum potassium levels were in the lower limits of normal. In the last 2 years, episodes of motor weakness have increased. He was admitted to our hospital, under the suspicion of recurrent Todd's paralysis. The serum potassium level ranged from 1.9 to 2.1 despite administration of potassium agents. Abdominal CT scans and 131 I-scintigraphy disclosed a left adrenal tumor. Elevation of plasma aldosterone and suppression of plasma renin were observed. The diagnosis of PA due to hypersecretion of aldosterone from an adrenal tumor was thus confirmed. We performed a total left adrenectomy 4 weeks after his admission. Histological examination showed a clear-cell type of benign adrenal adenoma. After the operation, laboratory data were normal and ACE inhibitors were able to normalize his diastolic hypertension. According to the literature, PA complicated by ICH is associated with a high rate of recurrence of cerebral vascular accidents if treatment of PA is not performed. Although diagnosis of PA in the early stage is difficult, as it was in our presented case, high suspicion of PA is essential for patients with diastolic hypertension and persistent hypopotassiumemia, particularly in young adults and middle-aged patients.

Adenoma↗

PubMed2001

[Diffusion-weighted magnetic resonance imaging (MRI) in acute brain stem infarction].

Diffusion-weighted magnetic resonance imaging (DWI) provides one of the earliest demonstrations of ischemic lesions. However, some lesions may be missed in the acute stage due to technical limitation of DWI. We therefore conducted the study to clarify the sensitivity of DWI to acute brain stem infarctions. Twenty-eight patients with the final diagnosis of brain stem infarction(midbrain 2, pons 9, medulla oblongata 17) who had been examined by DWI within 24 hours of onset were retrospectively analyzed for how sensitively the initial DWI demonstrated the final ischemic lesion. Only obvious(distinguishable with DWI alone without referring clinical symptoms and other informations) hyperintensity on DWI was regarded to show an ischemic lesion. Sixteen(57.1%) out of 28 patients had brain stem infarctions demonstrated by initial DWI. In the remaining 12 cases, no obvious ischemic lesion was evident on initial DWI. Subsequent MRI studies obtained 127 hours, on average after the onset showed infarction in the medulla oblongata in 11 cases and in the pons in one case. Negative findings of DWI in the acute stage does not exclude possibility of the brain stem infarction, in particulary medulla oblongata infarction.

Adult↗

PubMed2001

[CD34+ progenitor cell transplantation from HLA-mismatched donors to two patients with chronic active Epstein-Barr virus infection].

We report two boys with chronic active Epstein-Barr virus infection (CAEBV) refractory to conventional chemotherapy, who received HLA-mismatched allografts of CD34-positive progenitor cells from their fathers. One patient developed veno-occlusive disease (VOD) of the liver on day 18 after transplantation and died on day 26. The other patient received the allograft during partial remission. Although he suffered recurrent infections due to Streptococcus viridans, he is now doing well 23 months after transplantation. CAEBV refractory to chemotherapy is considered to be a fatal EBV-infected T/NK-cell lymphoproliferative disease, and our experiences suggest that CD34-positive progenitor cell transplantation for patients with CAEBV lacking HLA-matched donors may be a feasible and useful treatment. However, the timing of transplantation is considered to be critical, and should be performed when the patient is in good clinical condition.

Antigens, CD34↗

PubMed2000

Simultaneous induction of mitochondrial heat shock protein mRNAs in rat forebrain ischemia.

Several investigations have postulated evidence of the involvement of apoptosis in delayed neuronal death following brief periods of global cerebral ischemia. Apoptosis may be closely linked to mitochondrial dysfunction. Heat shock protein (HSP) 60 and HSP10 are mitochondrial matrix proteins induced by stress and form the chaperonin complex that is implicated in protein folding and assembly within the mitochondria. This study investigated the induction of these mitochondrial stress protein genes in the hippocampal CA1 region and less vulnerable regions following transient forebrain ischemia. In situ hybridization analysis revealed that the induction pattern of HSP60 mRNA was identical to that of HSP10 mRNA throughout the entire ischemic course. No changes occurred in the expression of both mRNAs after 2 min ischemia. Strong induction of both mRNAs occurred in the CA1 region after 10 min ischemia and persisted until 1 d after reperfusion. In contrast, induction of both mRNAs in the less vulnerable regions was terminated by 1 d after reperfusion. These results demonstrate that mitochondrial stress conditions persist concomitantly with cytosolic stress conditions in regions vulnerable to transient forebrain ischemia.

Animals↗

PubMed2000

Fatty acid induced glioma cell growth is mediated by the acyl-CoA synthetase 5 gene located on chromosome 10q25.1-q25.2, a region frequently deleted in malignant gliomas.

Acyl-CoA synthetase (ACS) ligates fatty acid and CoA to produce acyl-CoA, an essential molecule in fatty acid metabolism and cell proliferation. ACS5 is a recently characterized ACS isozyme highly expressed in proliferating 3T3-L1 cells. Molecular characterization of the human ACS5 gene revealed that the gene is located on chromosome 10q25.1-q25.2, spans approximately 46 kb, comprises 21 exons and 22 introns, and encodes a 683 amino acid protein. Two major ACS5 transcripts of 2.5- and 3.7-kb are distributed in a wide range of tissues with the highest expression in uterus and spleen. Markedly increased levels of ACS5 transcripts were detected in a glioma line, A172 cells, and primary gliomas of grade IV malignancy, while ACS5 expression was found to be low in normal brain. Immunohistochemical analysis also revealed strong immunostaining with an anti-ACS5 antibody in glioblastomas. U87MG glioma cells infected with an adenovirus encoding ACS5 displayed induced cell growth on exposure to palmitate. Consistent with the induction of cell growth, the virus infected cells displayed induced uptake of palmitate. These results demonstrate a novel fatty acid-induced glioma cell growth mediated by ACS5.

Adenoviridae↗

PubMed2000

Middle and long latency peak sources in auditory evoked magnetic fields for tone bursts in humans.

The relative position of the P50m and the N100m sources of the auditory evoked magnetic field remains unclear. Magnetoencephalography was performed in 24 normal subjects. Contralateral P50m to left and right ear stimulus was observed in 21 and 19hemispheres, respectively. Ipsilateral P50m to left and right ear stimulus was observed in 17 and 16hemispheres, respectively. N100m was observed in all subjects for all stimuli. Relative position of the equivalent current dipole of the P50m was 1.0+/-7.6 (mean+/-SD) mm posterior, 2.0+/-5.8mm inferior and 1.8+/-8.0mm medial to the N100m dipole position considering all observations. We suggest that the P50m and N100m sources are colocated in an extended area of the cortex.

Acoustic Stimulation↗

PubMed2000

Remote discharges in the posterior language area during basal temporal stimulation.

A 23-year-old woman with refractory complex partial seizures underwent implantation of subdural grid electrodes over the left hemisphere to map epileptic foci and language function. Aphasic symptoms occurred during stimulation of the basal temporal area, which were always associated with intrastimulus remote discharges (ISRDs) in the classical posterior language area. No sequential language deficits occurred after anterior temporal lobectomy including the basal temporal area. These results suggest a close functional relationship between the basal temporal area and posterior language area in patients with temporal lobe epilepsy. ISRDs may explain the paradoxical observation that resection of the basal temporal language area results in no language deficits.

Adult↗

PubMed2000

Reduction of the DNA base excision repair protein, XRCC1, may contribute to DNA fragmentation after cold injury-induced brain trauma in mice.

The X-ray repair cross-complementing group 1 (XRCC1) protein plays a central role in the DNA base excision repair pathway by interacting with DNA ligase III and DNA polymerase beta. The present study examined the protein expression of XRCC1 and DNA fragmentation before and after cold injury-induced brain trauma (CIBT) in mice, in which apoptosis is assumed to participate. Immunohistochemistry showed the nuclear expression of XRCC1 in the entire region of the control brains. Fifteen minutes after CIBT, nuclear immunoreactivity was predominantly decreased in the inner boundary of the lesion, followed by a significant reduction of XRCC1 in the entire lesion 4 h after CIBT. A characteristic 70-kDa band was detected in the non-traumatic area, and was markedly decreased after CIBT as shown by Western blot analysis. DNA fragmentation was also observed after CIBT, and double staining with XRCC1 immunohistochemistry and terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling showed a spatial relationship between XRCC1 loss and DNA fragmentation 24 h after CIBT. These data indicate that early decrease of XRCC1 and failure of the DNA repair mechanism may contribute to DNA-damaged neuronal cell death after CIBT.

Animals↗

PubMed2000

Role of IL-16 in delayed-type hypersensitivity reaction.

Interleukin (IL)-16 is a chemoattractant cytokine for CD4(+) leukocytes. Because delayed-type hypersensitivity (DTH) reaction is mediated by T helper 1 (Th1) cells and CD4(+) T cells can be chemoattracted by IL-16, we have investigated the involvement of IL-16 in the DTH reaction. Immunohistochemical analysis revealed the IL-16 expression in infiltrating cells and epithelial cells in the DTH footpads. The IL-16 expression was also detected intracellularly in the infiltrating cells. In addition, markedly increased production of IL-16 was detected in the DTH footpad extracts, but not in the control footpad extracts, by an enzyme-linked immunosorbent assay and also by Western blot analysis. The DTH footpad extracts exhibited a strong chemoattractant activity toward splenic T cells, which was significantly inhibited by the inclusion of neutralizing monoclonal antibody (mAb) against IL-16 in the migration assay. Furthermore, treatment of sensitized mice in vivo with the anti-IL-16 neutralizing mAb significantly suppressed the footpad swelling induced by an antigen challenge, together with decreased infiltration of leukocytes including not only CD4(+) T cells but also CD8(+) T cells and macrophages into the DTH footpads. Decreased production of macrophage inflammatory protein 1alpha was also observed in the DTH footpad extracts by the mAb treatment. These results suggest that IL-16 plays an important role in the recruitment of leukocytes-presumably including antigen-specific Th1 cells, which secrete cytokines and chemokines mediating the following hypersensitivity reaction after activation by the interaction with Langerhans cells carrying the antigen-for the elicitation of DTH response. (Blood. 2000;95:2869-2874)

Animals↗

PubMed2000

Two continuous spectrophotometric assays for methionine aminopeptidase.

Two spectrophotometric assays have been developed for methionine aminopeptidases (MetAPs). The first method employs a thioester substrate which, upon enzymatic removal of the N-terminal methionine, generates a free thiol group. The released thiol is quantitated using Ellman's reagent. The MetAP reaction is conveniently monitored on a UV-VIS spectrophotometer in a continuous fashion, with the addition of an excess of Ellman's reagent into the assay reaction. Two tripeptide analogues were synthesized and found to be excellent substrates of both Escherichia coli MetAP and human MetAP2 (k(cat)/K(M) = 2.8 x 10(5) M(-1) s(-1) for the most reactive substrate). In the second assay method, the MetAP reaction is coupled to a prolyl aminopeptidase reaction using Met-Pro-p-nitroanilide as substrate. MetAP-catalyzed cleavage of the N-terminal methionine produces prolyl-p-nitroanilide, which is rapidly hydrolyzed by the prolyl aminopeptidase from Bacillus coagulans to release a chromogenic product, p-nitroaniline. This allows the MetAP reaction to be continuously monitored at 405 nm on a UV-VIS spectrophotometer. The assays have been applied to determine the pH optima and kinetic constants for the E. coli and human MetAPs as well as to screen MetAP inhibitors. These results demonstrate that the current assays are convenient, rapid, and sensitive methods for kinetic studies of MetAPs and effective tools for screening MetAP inhibitors.

Aminopeptidases↗

PubMed2000

Microsatellite instability and the PTEN1 gene mutation in a subset of early onset gliomas carrying germline mutation or promoter methylation of the hMLH1 gene.

High-frequent microsatellite instability (MSI-H) was detected in two of the 80 gliomas examined, whlie the other 78 gliomas showed microsatellite stable (MSS) phenotype. Both of the two MSI-H tumors were glioblastomas which developed in teenage patients. One of the patient was diagnosed as having Turcot's syndrome and had a germline mutation in the hMLH1 gene. Loss of expression due to promoter methylation was selectively observed in the wild type allele of the hMLH1 gene in the tumor of this patient. The other patient had neither a family history nor a past personal history of malignancy. Although no mutation in the mismatch repair genes was detected in the tumor of this patient, the level of expression of the hMLH1 gene was markedly decreased and the promoter sequence of the gene was highly methylated. In the tumor of this patient, the PTEN1 gene, one of the genes carrying microsatellite sequences in their coding regions, was altered by a slippage mutation within five adenine repeat sequences. These findings indicate that the genetic or epigenentic inactivation of the hMLH1 gene is involved in a subset of early-onset gliomas and the PTEN1 gene could be a downstream target for mutation as observed in glioblastoma without MSI.

Adaptor Proteins, Signal Transducing↗