PubMed Health⌕ Search

Biomedical subjects

Y Ohtsuka

Publications and source records attributed to Y Ohtsuka.

At least 19 recordsLinked to original sources
PubMed2002

Effects of n-3 polyunsaturated fatty acids on dermatitis in NC/Nga mice.

The administration of n-3 polyunsaturated fatty acids (PUFAs) is known to be effective against allergic diseases by suppressing the production of eicosanoids derived from arachidonic acid. To investigate the mechanisms and efficacy of n-3 PUFA treatment in patients with atopic dermatitis (AD), we administered four different formulas of alpha-linolenic acid for 6 weeks in an AD model using NC/Nga mice. According to the doses of alpha-linolenic acid given, the levels of alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid in the red blood cell membranes increased while the levels of linoleic acid and arachidonic acid decreased. However, there was no significant difference among the four dose groups in clinical skin severity score, histopathological findings of skin lesions, or levels of total plasma IgE. Moreover, there was no significant difference in the production of leukotriene B(4) and Leukotriene C(4) from skin lesions after stimulation with A23187 among the groups, although the production of prostaglandin E(2) (PGE(2)) was significantly reduced and skin blood flow in the ear was significantly higher in the group given the highest dose of alpha-linolenic acid. Our results suggest that the administration of alpha-linolenic acid can change the fatty acid composition, PGE(2) production, and skin blood flow but may not prevent the development of dermatitis in NC/Nga mice.

Animals↗
PubMed2002

The relationship between paroxysmal kinesigenic choreoathetosis and epilepsy.

PURPOSE: To clarify the relationship between paroxysmal kinesigenic choreoathetosis (PKC) and epilepsy, we investigated the clinical and electroencephalographic (EEG) findings of patients with familial PKC and epilepsy, as well as sporadic cases with both PKC and epilepsy. PATIENTS AND METHODS: Patients consisted of 12 familial cases from seven families and three sporadic cases. The period of follow-up ranged from 17 months to 33 years, 7 months (average: 16 years, 8 months). During the follow-up, a total of 163 EEGs (11 EEGs per subject) were studied, including interictal and ictal EEGs. RESULTS: Transient epileptic discharges were found in ten of the 15 patients (66.7 %) during the clinical course. As for focus, centro-midtemporal and frontal spikes were most often observed. The ictal EEG of an afebrile convulsion in one patient showed a partial seizure with secondary generalization which originated from the frontal area. CONCLUSIONS: It appears that patients who suffer from both PKC and epilepsy have a functional abnormality of the cerebral cortex, particularly in the perirolandic and frontal regions.

Adolescent↗
PubMed2002

Dissociation between airway responsiveness to methacholine and responsiveness to antigen.

Repeated aerosolized antigen challenges to brown Norway (BN) rats generate nonspecific airway hyperresponsiveness (AHR). On the other hand, some studies have demonstrated that repeated antigen challenge could attenuate antigen-specific AHR in BN rats. The authors questioned whether such dissociation in airway responses actually occurs when assessed in a single study in the same animals. The authors simultaneously measured AHR to methacholine and antigen-specific AHR in rats that were repeatedly exposed to aerosolized ovalbumin (OA) for 1 or 3 months after sensitization. Four days after the last challenge, airway responses to methacholine and OA, morphometry of the airways, the cell profile in bronchoalveolar lavage fluid, and cytokine messenger ribonucleic acid (mRNA) expression in the lungs were evaluated. The two types of AHR were modulated in opposite directions by repeated antigen challenges. The AHR to methacholine was significantly increased in the rats receiving antigen challenges compared with the control rats receiving saline challenges after sensitization; whereas, the antigen-specific AHR was significantly decreased. The number of alveolar macrophages in lavaged fluid and the expression of transforming growth factor-beta1 mRNA in lung tissue was significantly different between the antigen-challenged rats and the control rats. In conclusion, dissociation between nonspecific airway hyperresponsiveness and antigen-specific airway hyperresponsiveness in brown Norway rats after repeated antigen challenges was demonstrated. Sustained airway inflammation with macrophages and/or upregulation of transforming growth factor-beta1 messenger ribonucleic acid in the lung tissue may be responsible for this dissociation.

Aerosols↗
PubMed2002

Development of a health guidance support system for lifestyle improvement. Committee of Health Evaluation Support System Council of Japan AMHTS Institutions.

OBJECTIVE: To provide automated advice for lifestyle adjustment based on an assessment of the results of a questionnaire and medical examination or health checkup data. METHODS: A system was developed that gathers data based on questions regarding weight gain, exercise, smoking, sleep, eating habits, salt intake, animal fat intake, snacks, alcohol, and oral hygiene; body mass index, resting blood pressure, fasting blood sugar, total cholesterol, triglycerides, uric acid and liver function tests. Based on the relationships between the lifestyle data and the health checkup data, a health assessment sheet was generated for persons being allocated to a multiple-risk-factor syndrome group. RESULTS: Health assessment and useful advice for lifestyle improvement were automatically extracted with the system, toward the high risk group for lifestyle related diseases. The system is operational. CONCLUSIONS: We developed a health guidance support system for lifestyle improvement. In comparison with conventional, limited advice methods, we developed a practical system that defined the necessity for lifestyle improvement more clearly, and made giving advice easier.

Counseling↗
PubMed2001

Induction of ascidian peripheral neuron by vegetal blastomeres.

Ascidian tadpole larvae have a similar dorsal tubular nervous system as vertebrates. The induction of brain formation from a4.2-derived (a-line) cells requires signals from the A4.1-derived (A-line) cells. However, little is known about the mechanism underlying the development of the larval peripheral nervous system due to the lack of a suitable molecular marker. Gelsolin, an actin-binding protein, is specifically expressed in epidermal sensory neurons (ESNs) that mainly constitute the entire peripheral nervous system of the ascidian young tadpoles. Here, we address the role of cell interactions in the specification of ESNs using immunostaining with an anti-gelsolin antibody. Animal half (a4.2- and b4.2-derived) embryos did not give rise to any gelsolin-positive neurons, indicating that differentiation of ESNs requires signals from vegetal cells. Cell isolation experiments showed that A4.1 blastomeres induce gelsolin-positive neurons from a-line cells but not from b4.2-derived (b-line) cells. On the other hand, B4.1 blastomeres induce gelsolin-positive neurons both from b-line cells and a-line cells. This is in sharp contrast to the specification of brain cells which is not affected by the ablation of B4.1-derived (B-line) cells. Furthermore, basic fibroblast growth factor (bFGF) induced ESNs from the a-line cells and b-line cells in the absence of vegetal cells. Their competence to form ESNs was lost between the 110-cell stage and the neurula stage. Our results suggested that the specification of the a-line cells and b-line cells into ESNs is controlled by distinct inducing signals from the anterior and posterior vegetal blastomeres. ESNs in the trunk appear to be derived from the a8.26 blastomeres aligning on the edge of presumptive neural region where ascidian homologue of Pax3 is expressed. These findings highlight the close similarity of ascidian ESNs development with that of vertebrate placode and neural crest.

Animals↗
PubMed2001

Highly chemo-, diastereo-, and enantioselective reduction of 1,2-dialkyl-3-aryl-1,3-diketones for preparation of aldol-type compounds.

[reaction: see text]. Highly chemo-, diastereo-, and enantioselective borohydride reduction of 2-substituted-1,3-diketones was achieved in the presence of the optically active beta-ketoiminato cobalt complex catalysts to afford the optically active 2-substituted-3-hydroxyketones. The present catalytic and enantioselective reduction could provide an alternative potential for preparation of optically active anti-aldol-type compounds.

Journal Article↗
PubMed2001

Reductive desymmetrization of 2-alkyl-1,3-diketones catalyzed by optically active beta-ketoiminato cobalt complexes.

[reaction: see text] The reductive desymmetrization of acyclic 1,3-diketones was achieved for the first time by catalytic borohydride reduction in the presence of optically active beta-ketoiminato cobalt(II) complex catalysts. In this reaction, various 2-substituted-1,3-diaryl-1,3-propanediones were converted into the corresponding optically active 2-substituted-1,3-diaryl-3-hydroxypropanone in good-to-high yields with excellent diastereo- and enantioselectivities and high catalytic efficiencies.

Journal Article↗
PubMed2001

Changes in gelsolin expression during ascidian metamorphosis.

Gelsolin is an actin regulatory protein that is expressed in a wide variety of tissues and is especially abundant in muscle and blood cells. The role of gelsolin during structural reorganization of the body, such as during metamorphosis or regeneration, is poorly understood. We analyzed changes in gelsolin expression during ascidian embryogenesis and metamorphosis using nucleic acid probes and a monoclonal antibody (AS23) specific for ascidian gelsolin; our results indicated that gelsolin is maternally provided and that its de novo gene transcription is initiated during the neurula stage. In the larva, gelsolin was detectable in specific types of nerve cells, i.e. the adhesive papillae, motor neurons and epidermal sensory neurons. During metamorphosis, the expression of gelsolin changes markedly: the expression is suppressed in nerve tissues after tail resorption but is induced in mesodermal tissues. Gelsolin accumulated in mesenchyme cells until the onset of tail resorption, and following tail resorption, these cells migrated to the tunic and differentiated into tunic cells with many fine processes. Migration of the mesenchyme cells into the tunic was completely inhibited by treatment with cytochalasin B. Gelsolin was colocalized with actin in tunic cells, suggesting that it is involved in the rearrangement of actin filaments during cell locomotion or morphogenesis.

Animals↗
PubMed2001

Strangulated umbilical hernia in a child: report of a case.

Most umbilical hernias in children close spontaneously. Complications associated with umbilical hernias are rarely observed during follow-up. We report herein a 5-month-old girl with a strangulated umbilical hernia. Her umbilicus was hard, reddish, and irreducible. Plain radiography of the abdomen showed signs of mechanical ileus. The patient was thus diagnosed to have a strangulated umbilical hernia. A 5-cm section of the ascending colon and a 5-cm section of the terminal ileum, as well as the cecum and appendix, were congested, edematous, and erythematous, and together were enclosed by a firm hernial ring. A closure of the fascial defect and umbilicoplasty were performed. The postoperative course was uneventful. In patients with infantile umbilical hernias, strangulation may occur as the fascial defect decreases in size.

Constriction, Pathologic↗
PubMed2001

Electroencephalographic changes and their regional differences during pediatric cardiovascular surgery with hypothermia.

Monitoring brain function by EEG is an important means of preventing cerebral insults in pediatric cardiovascular surgery. We studied intraoperative EEG changes and their regional differences associated with hypothermia and brain ischemia. The subjects of this study consisted of 13 children ranging in age from 4 months to 4 years and 6 months. Multi-channel EEGs were recorded using a portable digital EEG system, and the EEG changes were examined by visual inspection and computerized analyses. The results were as follows. (1) During cooling, a discontinuous EEG pattern was transiently observed in four patients, and this phenomenon indicated rapid suppression of cerebral function and subsequent adaptation. (2) Regarding the patterns of change in equivalent potentials induced by hypothermia, there were two different patterns depending on the degree of hypothermia, and the borderline rectal temperature was found to be around 32 degrees C. (3) During cooling, regional differences in the changes in equivalent potentials were observed in nine patients. A decrease in slow waves was marked in the occipital head area, and a decrease in fast waves was prominent in the anterior head area. (4) Arterial hypotension caused transient EEG abnormalities. Of them, bilaterally synchronous rhythmic high voltage slow waves were remarkable and exhibited bifrontal or bicentral dominance. (5) The EEG changes induced by hypothermia were influenced not only by the rectal temperature itself, but also by the rate of change in rectal temperature, and we speculated that this phenomenon was a result of adaptation. In intraoperative EEG monitoring, these findings constitute the basis for early detection of a cerebral hypoxic-ischemic state during pediatric cardiovascular surgery.

Body Temperature↗
PubMed2001

Spasms in clusters in epilepsies other than typical West syndrome.

Although spasms in clusters are one of the major characteristics of West syndrome (WS), there are a significant number of patients who show spasms in clusters but do not fit the standard pattern of WS. It is possible to divide these atypical cases into the following three groups. Group 1: refractory epilepsies beginning in early infancy, associated with atypical electroencephalographic (EEG) features; Group 2: generalized epilepsies with spasms in clusters at ages of 2-3 years or above; and Group 3: localization-related epilepsies with spasms in clusters. Ictal clinical and EEG findings of spasms in clusters in these atypical patients and also those in WS are similar. Patients in Group 1 often suffer from Aicardi syndrome, cortical malformations, early myoclonic encephalopathy and Ohtahara syndrome. Most patients in Group 2 suffer from Lennox-Gastaut syndrome and other generalized epilepsies such as severe epilepsy with multiple independent spike foci. A significant number of them had a history of WS. Small number of patients in Group 2 can be diagnosed as having late-onset WS or long-lasting WS. In Groups 1 and 3 patients, cortical mechanisms play a critical role in their pathophysiology. The presence of older patients with spasms in clusters might indicate not only developing process of the brain but also some selective dysfunction of the brain plays an important role in the occurrence of spasms in clusters. Investigations on these atypical patients can help the understanding of pathophysiological mechanisms of WS and its related epileptic syndromes.

Brain↗
PubMed2001

Predictors and underlying causes of medically intractable localization-related epilepsy in childhood.

The goal of this study is to clarify the prognostic factors in childhood localization-related epilepsy in a tertiary medical center. Children (n = 113) with symptomatic and cryptogenic localization-related epilepsy were divided into groups of intractable patients (average seizure frequency: one or more per month during the 6 months before the last follow-up; n = 40) and well-controlled patients (no seizures for at least 1 year before the last follow-up; n = 73). Clinical and electroencephalogram (EEG) factors were examined to elucidate prognostic factors. The subtypes of epilepsies and causes were also investigated. Univariate analyses indicated that the following factors were correlated with seizure outcome: (1) seizure type at the first visit; (2) seizure frequency; (3) underlying cause; (4) age at onset of epilepsy; (5) status epilepticus occurring as the first seizure and before the first visit; and (6) diffuse epileptic discharges on first visit interictal EEGs. Multivariate analyses revealed that seizure type at the first visit, seizure frequency, status epilepticus before the first visit, and underlying causes were significant independent predictive factors. The rate of intractable patients was highest in multilobar epilepsy, followed by frontal-lobe epilepsy. Regarding etiologies, the intractable group contained nine patients with encephalitis of unknown origin and three each with localized cortical malformation and mesial temporal sclerosis.

Brain↗
PubMed2001

Extended polyglutamine selectively interacts with caspase-8 and -10 in nuclear aggregates.

A growing number of inherited neurodegenerative disorders, including Huntington's disease, have been shown to be caused by the expansion of CAG/polyglutamine repeats. The molecular mechanism underlying these disorders, however, has yet to be clarified. We and others previously demonstrated that caspase-8 was activated by proteolysis in association with the expression of extended polyglutamine. Here, we further analyzed the selectivity of caspases in the process mediated by extended polyglutamine. Among upstream caspases, caspase-10, a close homolog of caspase-8, was also proteolytically activated, but caspase-9 was not. Caspase-8 and -10 were recruited into nuclear aggregates of extended polyglutamine, where at least a fraction of these caspases was converted to the activated forms. Caspase-8 and -10 were co-immunoprecipitated with polyglutamine only when the polyglutamine was pathologically extended, whereas caspase-2, -3, -6, -7 and -9 were not co-immunoprecipitated with polyglutamine regardless of its size. A dominant-negative form of caspase-8 with a mutation at the catalytic cysteine residue inhibited polyglutamine-mediated nuclear apoptotic phenotype. These results suggest that caspase-8 and -10 are autoactivated as a result of close proximity of the proforms of these molecules that occurs due to aggregate formation, which reveals a novel toxic gain-of-function mechanism for the pathogenesis of CAG-repeat disorders.

Apoptosis↗
PubMed2001

Combined use of sphenoidal electrodes and the dipole localization method for the identification of the mesial temporal focus.

UNLABELLED: We attempted to sub-classify four cases who show temporal spikes on standard scalp electroencephalogram (EEG), using sphenoidal electrodes and the dipole localization METHOD: In a case with mesial temporal epilepsy, spikes showed phase reversal in a sphenoidal electrode, and the spike dipoles were estimated to be in the mesial temporal lobe. In a case with lateral temporal epilepsy, spikes showed no phase reversal in a sphenoidal electrode, and the spike dipoles were estimated to be in the lateral temporal lobe. In two cases out of four, spikes showed phase reversal in sphenoidal electrodes, whilst the dipoles were estimated to be in the frontal lobe. Clinical features also suggested a diagnosis of frontal lobe epilepsy. In one of the two cases in which frontal lobe epilepsy was suspected, ictal dipoles as well as interictal spike dipoles indicated participation of the frontal lobe in the genesis of seizures. Nevertheless, only mesial temporal lobectomy was performed based on results obtained by invasive subdural electrodes. As a result, seizures were not controlled. Although sphenoidal electrodes were useful for differentiating between mesial and lateral temporal lobe foci, it is advisable to use them in combination with the dipole localization method to identify frontal lobe foci.

Action Potentials↗
PubMed2001

Pulsed Doppler sonography for the diagnosis of strangulation in small bowel obstruction.

BACKGROUND/PURPOSE: This study was undertaken to assess the usefulness of pulsed Doppler sonography (PDS) for the detection of strangulation in small bowel obstruction by evaluating the hemodynamics in the superior mesenteric artery (SMA). METHODS: The authors performed PDS in 117 normal children: 22 children aged 0 to 1 months (group I), 27 children aged 1 to 12 months (group II), 36 children aged 1 to 6 years (group III), and 32 children aged 7 to 15 years (group IV). Patients included 25 with simple obstruction: 1 in group II, 10 in group III, and 14 in group IV; and 9 with strangulating obstruction: 2 in group I, 2 in group II, 3 in group III, and 2 in group IV. The authors measured the peak-systolic velocity, end-diastolic velocity (EDV), and mean average velocity and calculated the resistive index (RI). RESULTS: The authors observed both a significant decrease in the EDV and increase in the RI for the SMA in strangulating obstruction compared with simple obstruction. CONCLUSION: Analysis of the hemodynamics in the SMA using PDS is useful to differentiate strangulating obstruction from simple obstruction.

Adolescent↗
PubMed2001

Pulsed Doppler sonography of the hilar renal artery: differentiation of obstructive from nonobstructive hydronephrosis in children.

BACKGROUND/PURPOSE: It is difficult to detect the arcuate or cortical renal arteries when performing pulsed Doppler sonography (PDS) for congenital hydronephrosis. This study was undergone to assess the usefulness of PDS of the hilar renal artery to differentiate obstructive from nonobstructive hydronephrosis. METHODS: The authors performed PDS of the hilar renal artery in 80 normal children: 20 aged 0 to 1 months (group I), 20 aged 1 to 12 months (group II), 20 aged 1 to 6 years (group III), and 20 aged 7 to 15 years (group IV). Based on diuretic renography findings, 22 kidneys from 19 children with a ureteropelvic junction (UPJ) stricture were divided into 7 dilated obstructed and 15 dilated nonobstructed kidneys. The peak-systolic velocity (PSV), end-diastolic velocity (EDV), mean average velocity (Vm) and the resistive index (RI = [PSV - EDV]/PSV) were measured at the hilar renal artery. RESULTS: There was a significant difference in the RI of the hilar renal artery between obstructive and nonobstructive hydronephrosis. CONCLUSION: A pulsed Doppler evaluation of the hilar renal artery is useful for detecting an obstructive UPJ stricture compared with assessing arcuate or cortical renal arteries.

Adolescent↗
PubMed2001

Successful surgical treatment of two cases of congenital chylous ascites.

The authors report on 2 patients with congenital chylous ascites who underwent successful lymphatic duct ligation after a laparoscopic lymphoid dye test. Fetal ascites had been detected in both cases, and both babies were born with marked abdominal swelling. Given that conservative treatment by medium-chain triglyceride (MCT) milk and total parenteral nutrition (TPN) was ineffective, the authors elected to perform lymphatic duct ligation on the 95th postnatal day in the former case and on the 27th postnatal day in the latter case. Lipophilic dye was administered preoperatively both through oral and subcutaneous routes, and the peritoneal cavity was explored using laparoscopy. This laparoscopic lymphoid dye test precisely identified the area of chylous leakage, and the authors were able to repair the malformed lymphatic duct directly at laparotomy. Both postoperative courses have been favorable with no recurrence of symptoms. The lymphatic duct ligation should be considered in cases resistant to conservative treatment for over a month. The present laparoscopic lymphoid dye test is a novel and useful procedure that allows surgeons to identify the exact location of chylous leakage, and thus successfully ligate the lymphatic duct.

Chylous Ascites↗