Biomedical subjects

Toshiaki Hashimoto

Publications and source records attributed to Toshiaki Hashimoto.

15 recordsLinked to original sources

PubMed2007

Short-latency somatosensory evoked potentials in infantile autism: evidence of hyperactivity in the right primary somatosensory area.

Children with infantile autism sometimes show hyperesthesia or hypoesthesia to touch, pain, and/or temperature. To clarify the pathophysiology, we examined short-latency somatosensory evoked potentials (S-SEPs), elicited by median nerve stimulation, in 24 children with infantile autism (17 males, seven females; age range 2y 2mo-9y; mean age 4y 2mo [SD 1y 7mo]). We also evaluated relationships between S-SEP findings and clinical manifestations. Of the 24 children, 10 showed abnormal S-SEPs as follows: prolonged peak latency of N20 (n=2), extended interpeak latency of P13/14-N20 (n=7), appearance of a giant SEP (n=1), and a more than twofold right hemispheric peak-to-peak amplitude predominance of N20-P25 (n=5). In addition, a peak-to-peak amplitude of N20-P25 elicited by left median nerve stimuli was significantly higher than that obtained with right median nerve stimuli, which indicated right hemispheric hyperactivity relative to the left (p=0.008). Infantile autism is frequently associated with somatosensory abnormalities and right hemispheric hyperactivity relative to the left, especially in the primary somatosensory area. This is believed to contribute to the pathophysiology of infantile autism, especially the idiopathic form.

Autistic Disorder↗

PubMed2006

Patients with West syndrome whose ictal SPECT showed focal cortical hyperperfusion.

To clarify the mechanism of clustered spasms in West syndrome (WS), we examined ictal SPECT and EEG, as well as those during the interictal period, in three patients with symptomatic WS who had apparent focal cerebral lesions. For ictal SPECT and EEG, we monitored the patients with EEG, and as soon as we noticed the occurrence of clustered spasms clinically and electroencephalographically, [(99m)Tc]ECD was injected intravenously and flushed thoroughly with saline. In these three patients, regional cerebral blood flow (rCBF) increased during ictus and decreased during the interictal period in the area that coincided with the focal cerebral lesion recognized by CT/MRI. The ictal hyperperfusion of bilateral basal ganglia was also detected in two of the three patients. The ictal EEG showed a diffuse slow wave complex corresponding to a clinical spasm. The sharp waves that preceded the diffuse slow wave complex and the spasm appeared in the same area in which rCBF increased during ictus. None of the patients showed partial seizure before or after clustered spasms clinically or electroencephalographically during the ictal SPECT study. Secondary generalization from a cerebral focus may explain the mechanism of spasms in these patients with WS: focal cortical discharge may primarily generate clustered spasms and trigger the brainstem and basal ganglia structures to produce spasms.

Cerebral Cortex↗

PubMed2005

Nuclear transportation of diacylglycerol kinase gamma and its possible function in the nucleus.

Diacylglycerol kinases (DGKs) convert diacylglycerol (DG) to phosphatidic acid, and both lipids are known to play important roles in lipid signal transduction. Thereby, DGKs are considered to be a one of the key players in lipid signaling, but its physiological function remains to be solved. In an effort to investigate one of nine subtypes, we found that DGKgamma came to be localized in the nucleus with time in all cell lines tested while seen only in the cytoplasm at the early stage of culture, indicating that DGKgamma is transported from the cytoplasm to the nucleus. The nuclear transportation of DGKgamma didn't necessarily need DGK activity, but its C1 domain was indispensable, suggesting that the C1 domain of DGKgamma acts as a nuclear transport signal. Furthermore, to address the function of DGKgamma in the nucleus, we produced stable cell lines of wild-type DGKgamma and mutants, including kinase negative, and investigated their cell size, growth rate, and cell cycle. The cells expressing the kinase-negative mutant of DGKgamma were larger in size and showed slower growth rate, and the S phase of the cells was extended. These findings implicate that nuclear DGKgamma regulates cell cycle.

Active Transport, Cell Nucleus↗

PubMed2005

The presence of donor-reactive CD4 T cells in early-phase liver-induced tolerance in rats: analysis using donor passenger leukocytes from the recipient.

In previous studies, we showed that the recipient spleen 12 h after liver transplantation included highly immunogenic donor passenger leukocytes (PLs) in the non-rejector rat strain combination (Lewis: LEW-->Wistar Furth: WF). Furthermore, we noted that giving anti-CD4 mAb to WF recipients at the time of liver grafting prolonged the liver damage due to primary rejection reaction, suggesting that CD4 T-cell regulation but not the deletional mechanism played a dominant role during the induction phase of tolerance in this combination. We proposed that in vitro CD4 T-cell response to the donor PLs from the recipient lymphoid organ may be observed in the early phase of tolerance induction. We initially observed donor-specific acceptance by 10 days after liver transplantation from the result of secondary heart transplantation, and showed that donor (LEW) PLs in recipient WF spleen 12 h after grafting were able to prime cytotoxic CD8 T cells in vivo. We then isolated functional donor PLs from the recipient WF spleen and established in vitro proliferation assay. When the enriched donor PLs were used as stimulator cells in the proliferation assay, a powerful alloimmunostimulatory ability was observed. Moreover, a potent response of recipient splenocytes to the PLs was observed on postoperative day 14. From these observations, we confirmed that clonal deletion of donor-reactive CD4 T cells did not participate in early phase of tolerance induction in this setting.

Animals↗

PubMed2005

Administration of secretin for autism alters dopamine metabolism in the central nervous system.

We evaluated the clinical effects of intravenously administered secretin in 12 children with autism (age range: 4-6 years, median age: 9 years, boy:girl=8:4). In addition, we investigated the association between improvement in symptoms and changes in the cerebrospinal fluid (CSF) homovanillic acid (HVA),5-hydroxyindole-3-acetic acid (5-HIAA), and 6R-5,6,7,8-tetrahydro-L-biopterin (BH(4)) levels after administration. After administration of secretin, the Autism Diagnostic Interview-Revised (ADI-R) score improved in 7 of the 12 children. However, the score deteriorated in 2 of the 12 children (in the item of 'restricted and repetitive, stereotyped interests and behaviors'). The HVA and BH(4) levels in CSF were increased in all children with improvement in the ADI-R score. In contrast, no patient without the elevation of the BH(4) level showed improvement in the score. These findings suggest that secretin activated metabolic turnover of dopamine in the central nervous system via BH(4), improving symptoms.

Autistic Disorder↗

PubMed2005

CD4 T-cell regulation of cytotoxic T cells during the induction phase of liver-induced spontaneous tolerance in rats.

PURPOSE: To check for in vivo CD4 T-cell-mediated inhibition of the immune response in rats with spontaneously accepted liver transplants. METHODS: Using the Lewis to Wistar Furth rat strain combination, we performed transient in vivo depletion of CD4 T-cells by anti-CD4 monoclonal antibodies (mAb) after liver transplantation. We used the CTL assay to detect primed T cells. We also retransplanted a grafted donor liver, parked for 3 days, into a secondary naive recipient rat. RESULTS: When Lewis rat livers were transplanted into the recipient Wistar Furth rats, the grafts suffered an early immune attack, followed by spontaneous acceptance without immunosuppression. However, giving anti-CD4 mAb to the recipients at the time of grafting prolonged the acute rejection reaction. Furthermore, giving anti-CD4 therapy on postoperative days (PODs) 21 and 35, but not on PODs 56 and 100, induced transient liver damage in recipients overcoming acute rejection. No primed T cells were detected by the CTL assay in the recipient rats within 2 months after transplantation. Meanwhile, the retransplanted liver had no ability to elicit an immune attack. CONCLUSIONS: CD4 T cells seemed to downregulate the effector function of T cells, but not T-cell proliferation in this model.

Alanine Transaminase↗

PubMed2005

Clinical aspects of hemimegalencephaly by means of a nationwide survey.

We surveyed Japanese patients with hemimegalencephaly by means of a questionnaire. Clinical findings, including intellectual and motor function levels and epileptic symptoms, were investigated. All 44 patients (28 males and 16 females) with hemimegalencephaly were sporadic. Sixteen patients had underlying neurocutaneous syndromes. The number of patients with right-sided hemimegalencephaly (n = 29) was almost twice that of patients with left-sided hemimegalencephaly (n = 15). Forty-one patients had mental retardation and hemiparesis and 14 patients were bedridden. All patients had epileptic seizures, which first appeared within a month in 18 cases and within 6 months in 11 cases. In 42 patients, magnetic resonance imaging revealed both cortical and white-matter abnormalities in the affected hemisphere. Antiepileptic drugs were not very effective. Fifteen patients were surgically treated. Eleven patients underwent functional hemispherectomy, which resulted in fairly good seizure control and improved development. There is a correlation between the onset of epilepsy and the degree of clinical severity of motor deficit and intellectual level. Neither underlying disorders nor laterality of the affected side was related to the degree of clinical severity.

Adolescent↗

PubMed2005

Findings of brain 99mTc-ECD SPECT in high-functioning autism--3-dimensional stereotactic ROI template analysis of brain SPECT.

The aim of this study is confirmation of an abnormal regional cerebral blood flow (rCBF) pattern in high-functioning autism (HFA). Confirmation of an abnormal rCBF pattern in HFA may be useful for elucidate of its pathophysiology and a differential diagnosis, such as with attention-deficit/hyperactivity disorder (AD/HD). Brain 99mTc-ECD SPECT was performed in 16 cases of HFA. The HFA group consisted of 16 cases of HFA. They were all male, with an IQ of 76-126. They had normal brain MRI findings, and had an age of 9-14 years. We examined abnormal rCBF in HFA by comparing the results to those in the control group. The control group consisted of 1 male and 4 females cryptogenic epilepsy patients with normal intelligence. They have no problems in learning at school or mental or behavioral traits. They had normal brain MRI or SPECT findings, and had an age of 7-15 years. 3-dimensional stereotactic ROI template (3DSRT) was used to analyze SPECT data. We calculated the 'relative rCBF (%)' (RI count of each segment x 100/Sum of RI count of the corresponding hemisphere), and compared the values between the two groups. We found a significantly low 'relative rCBF (%)' in the left temporal region in the HFA group. We also calculated the 'L/R ratio' (the 'relative rCBF (%)' of a segment on the left side / the 'relative rCBF (%)' of the corresponding segment on the right side), and compared the value for each segment between the two groups. There were no significant differences in any segments between the two groups. We also checked for differences in the 'relative rCBF (%)' between segments on the right side and corresponding segments on the left side in both the HFA and control groups. We found significant right < left perfusion in the angular region and significant left < right perfusion in the pericallosal, thalamus, and hippocampus region in the HFA group. We also found significant right < left perfusion in the temporal region in the control group. Significant hypoperfusion in the left temporal region due to an unidentified underlying brain pathology and abnormal laterality in the angular, temporal (lack of right < left perfusion), pericallosal, thalamus, and hippocampus regions may influence the symptoms of autism.

Adolescent↗

PubMed2005

[High functioning pervasive developmental disorder: coexistence with other clinical disorders].

We examined 50 children in high functioning pervasive developmental disorder (HFPDD) to study the comorbidity with other clinical disorders by questionnaires. Seventy-two percentage of them met the criteria for attention deficit hyperactivity disorder (AD/HD). The majority of the children had intelligence quotient less than 90. Learning problems, motor control problems, abnormal responses to sensory stimuli and anxiety disorder frequently coexisted in the children. Since clinical symptoms of HFPDD so diverse, it is possible that some children with HFPDD may be overlooked and diagnosed as having its coexisting disorders.

Adolescent↗

PubMed2005

[Autistic disorders].

Autism is a syndrome that consists of disturbances in social interactions, communication and imagination, and its first-choice of therapy is education. Of special interest is the period of the onset and early diagnosis of autism, and its relation to the period of intervention. In retrospective studies from questionnaire and home videotape analysis, it has been reported that autistic children display significantly less social interaction, joint attention behavior and communicative behavior compared to typical children, before 12 to 18 months of age. Although there is less evidence of a marked reduction in autistic symptomatology, early intervention studies have been found to have positive effects with significant improvements being reported in social behavior, self care, and academic skill. However, early interventions are controversial. We discuss early diagnosis and interventions in children with autism in this paper.

Autistic Disorder↗

PubMed2004

Successful management of intractable epilepsy with lidocaine tapes and continuous subcutaneous lidocaine infusion.

PURPOSE: We report the successful management of a 10-year-old girl with intractable frontal lobe epilepsy by using lidocaine tapes and continuous subcutaneous lidocaine infusion. METHODS: This patient's seizures were refractory to conventional antiepileptic drugs (AEDs) and mexiletine, but they responded well to the intravenous infusion of lidocaine. The intravenous infusion of lidocaine was replaced by lidocaine tape therapy, and subsequently by continuous subcutaneous lidocaine infusion therapy. The lidocaine tape (Penles, Nihon Lederle, Tokyo Japan) used was a stamp-sized (30.5 x 50.0 mm) tape containing 18 mg of lidocaine. We used 25 lidocaine tapes every 12 h (50 tapes/day). Lidocaine hydrochloride (10%) was administered continuously at a dose of 1.5 mg/kg/h (0.3 ml/hour) through a 27-G needle that was inserted in the subcutaneous tissue. RESULTS: Lidocaine tape therapy showed good efficacy for 1 year. After that, six lidocaine tapes were added 6 h after the exchange of 25 lidocaine tapes [62 tapes/day (25,6,25,6)], because the seizures became frequent when the lidocaine tapes were being exchanged. The seizures were then well controlled, but dermatitis due to the lidocaine tapes grew serious, and lidocaine tape therapy had to be stopped. Continuous subcutaneous infusion of lidocaine applied in place of lidocaine tapes provided long-term seizure control without remarkable side effects. CONCLUSIONS: Lidocaine tape therapy and continuous subcutaneous lidocaine infusion therapy were considered to be useful for controlling this patient's seizures. This is the first report to describe the efficacy of continuous subcutaneous lidocaine infusion therapy for epilepsy.

Administration, Cutaneous↗

PubMed2004

[Cooperation between medicine and education].

In cooperation between medicine and education, a reciprocal understanding is important. For this reason, we researched the needs of medical and educational professionals by questionnaires. Many child neurology specialists agreed that their medical profiled are unveiled in public about attending developmental disabilities. Some educational professionals felt it necessary to be given to offer medical informations of students such as treatments and/or diagnosis of their disease, to attend to seminars and lectures on developmental disabilities, and to obtain consultations of doctor more easily. From the above results, we propose an ideal cooperation between medicine and education.

Cooperative Behavior↗

PubMed2004

[Efficacy of secretin for the treatment of autism].

We administered secretin intravenously to 14 patients with autism (9 to 14 years, 10 males; 4 females), and evaluated its clinical effect. We also measured cerebrospinal fluid (CSF) levels of homovanillic acid (HVA) and 5-hydroxy-indole-3-acetic acid (5HIAA) before and after 4 weeks treatment, and compared them with the grade of improvement of the clinical symptoms assessed by the scores of Autism Diagnostic Interview-Revised (ADI-R). After injection of secretin, the ADI-R score increased in 8 patients, but declined in 3. Improvement was observed in functions such as sociability (interpersonal relationships), communication and speech improved, whereas in the others. symptoms such as hyperkinesias and stereotyped behavior became worse. The CSF levels of HVA was significantly increased in all of the patients showing an improvement in the ADI-R score. SHIAA levels also tended to increase, although this increase was not significant. These findings suggest that secretin promotes the metabolism of serotonin and dopamine in the central nervous system, which may contribute to improvement in clinical symptoms of autism.

Adolescent↗

PubMed2003

[An open trial of risperidone in autistic children].

Clinical effects of risperidone were evaluated in 9 young autistic children under informed consent of their parents. The patients were evaluated by the Children's Behavioral Checklist and Rutter's Autistic Behavioral Rating Scale. After the administration, two subjects (playing and adaptation to change) of the Children's Behavioral Checklist and four (anomalous autistic behavior, destructive behavior, developmental problem and activity level) of the Rutter's Autistic Behavioral Rating Scale were improved significantly. There were no serious side effects such as extrapyramidal symptoms except minor adverse effects including sedation, depression, increased appetite and constipation. Risperidone might be effective for serious behavioral disturbances in young autistic children.

Antipsychotic Agents↗

PubMedDate not supplied

Two cases of ileosigmoid knot: the youngest reported patient and CT findings.

Ileosigmoid knot is one of the causes of intestinal obstruction, but it is very difficult to make a correct preoperative diagnosis of the disease. This rare condition with high mortality is usually found in adult patients and has rarely been reported in children. We recently experienced two patients with ileosigmoid knot. One was a 4-year-old boy and the other a 60-year-old man. Both patients had suffered the sudden onset of abdominal pain. The boy was in a state of shock on admission. Abdominal computed tomography findings indicated intestinal obstruction. In laparotomy, intestinal resection and detorsion without resection were performed for the boy and adult patients, respectively. We herein report a case of ileosigmoid knot in which the patient was the youngest reported in the English literature, and showed that the computed tomography examination provided valuable information in both patients.

Child, Preschool↗