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Biomedical subjects

Y Ohtsuka

Publications and source records attributed to Y Ohtsuka.

At least 19 recordsLinked to original sources
PubMed2006

Hypercalcemia in childhood acute lymphoblastic leukemia: frequent implication of parathyroid hormone-related peptide and E2A-HLF from translocation 17;19.

Hypercalcemia is relatively rare but clinically important complication in childhood leukemic patients. To clarify the clinical characteristics, mechanisms of hypercalcemia, response to management for hypercalcemia, incidence of t(17;19) and final outcome of childhood acute lymphoblastic leukemia (ALL) accompanied by hypercalcemia, clinical data of 22 cases of childhood ALL accompanied by hypercalcemia (>12 mg/dl) reported in Japan from 1990 to 2005 were retrospectively analyzed. Eleven patients were 10 years and older. Twenty patients had low white blood cell count (<20 x 10(9)/l), 15 showed hemoglobin> or =8 g/dl and 14 showed platelet count > or =100 x 10(9)/l. Parathyroid hormone-related peptide (PTHrP)-mediated hypercalcemia was confirmed in 11 of the 16 patients in whom elevated-serum level or positive immunohistochemistry of PTHrP was observed. Hypercalcemia and accompanying renal insufficiency resolved quickly, particularly in patients treated with bisphosphonate. t(17;19) or add(19)(p13) was detected in five patients among 17 patients in whom karyotypic data were available, and the presence of E2A-HLF was confirmed in these five patients. All five patients with t(17;19)-ALL relapsed very early. Excluding the t(17;19)-ALL patients, the final outcome of ALL accompanied by hypercalcemia was similar to that of all childhood ALL patients, indicating that the development of hypercalcemia itself is not a poor prognostic factor.

Adolescent↗
PubMed2006

Genetic linkage analysis of pulmonary fibrotic response to silica in mice.

Inter-individual variations in the development of silicosis, even within the same environments, have been reported, which suggest the contribution of genetic factors in silicosis aetiology. The aim of the present study was to determine whether there is any significant genetic influence on the development of silicosis. Furthermore, which genetic loci are responsible for the pulmonary response to silica exposure? Eight strains of inbred mice were used to examine the genetic influence on the lung fibrotic response to silica exposure. After intercross-breeding between the most susceptible and most resistant strains, a genome-wide linkage analysis of quantitative trait loci (QTL) was performed. Hydroxyproline was applied as an index, and genotypes of 167 marker genes were analysed by fragment analysis using a capillary-type sequencer. There was significant inter-strain difference in the mean concentration of hydroxyproline contents among the eight strains of mice. Breeding studies were conducted between the most susceptible, C57BL/6J, and the most resistant strain, CBA/J. A genome-wide linkage analysis of silica-exposed intercrossed cohorts identified significant QTL on chromosome 4 and suggestive QTL on chromosomes 3 and 18. The present study demonstrates that genetic factors may play a significant role in fibrotic-lung responses to silica; one significant and two suggestive quantitative trait loci were identified.

Air Pollutants, Occupational↗
PubMed2006

Promoter polymorphism in the macrophage migration inhibitory factor gene is associated with obesity.

OBJECTIVE: To explore the association of promoter polymorphisms of macrophage migration inhibitory factor (MIF) gene with obesity. SUBJECTS: In total, 213 nondiabetic Japanese subjects. They were divided into three groups according to World Health Organization definitions: lean (body mass index (BMI) <25 kg/m2), overweight (25 < or = BMI < 30 kg/m2) and obese (BMI> or = 30 kg/m2). METHODS: We examined two polymorphic loci in the MIF gene in the subjects: a single-nucleotide polymorphism at position -173 (G/C) and a CATT-tetranucleotide repeat polymorphism at position -794, which both can affect promoter activity in different cells. RESULTS: We detected four alleles: 5-, 6-, 7- and 8-CATT at position -794. Genotypes without the 5-CATT allele (X/X, X refers to 6-, 7- or 8-CATT alleles) were more common in obese subjects than in lean or overweight groups (P = 0.013). The X-CATT allele was more frequent in obese subjects than in lean or overweight subjects (P = 0.030). In contrast, -173G/C was not associated with obesity. Among the haplotypes of the two promoter polymorphisms, G/5-CATT ((-173G/C)/(-794[CATT](5-8))) was associated with a decreased risk of obesity (P = 0.025) and G/6-CATT with an increased risk of overweight (P=0.028). CONCLUSION: Promoter polymorphism in the MIF gene is linked with obesity.

Adult↗
PubMed2005

Secondary oxidation product on Si(111)-(7 x 7) characterized by isotope-labeled vibrational spectroscopy.

The reaction of O(2) with Si(111)-(7 x 7) has been studied by electron energy-loss spectroscopy at 82 K. In addition to the losses due to Si-O-Si configurations, we observed two Si-O stretch modes depending on the coverage. A 146-meV peak appears at the initial reaction stage and was ascribed to a metastable product with one oxygen atom bonding on top of Si adatom and the other inserted into the backbond. The initial product is further oxidized to produce the second Si-O stretch peak at 150 meV. The secondary product was partially substituted with isotopes and analyzed with a simple model of coupled oscillators. The vibrational spectra reflect dynamical couplings between the isotopes, which is consistent with those predicted from the tetrahedral SiO(4) structure with one on top and three inserted oxygen atoms.

Journal Article↗
PubMed2005

Immunological development of preterm infants in early infancy.

To evaluate the immunological development of preterm infants, especially in early infancy, we examined the serum cytokine levels and the expression of Th2 and Th1 chemokine receptors, CCR4 and CCR5, on days 0, 14 and 28 in 16 low birth weight infants (1720.38 +/- 502.80 g) born at less than 37 (33.63 +/- 3.29) weeks of gestation. Using an enzyme-linked immunosorbent assay (ELISA), serum interleukin (IL)-4 levels exhibited an increase on day 14, but decreased to the initial level on day 28 (P < 0.05). The significant elevation of serum transforming growth factor (TGF)-beta levels was confirmed on day 14 (P < 0.05) but decreased to the initial level on day 28 (P < 0.05). The expression of CCR4 and CCR5 were examined using reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometric analysis. The RT-PCR confirmed the expression of CCR5-mRNA soon after birth, while there was no expression of CCR4-mRNA. Thereafter, the expression of CCR4-mRNA increased significantly and reached the level of CCR5-mRNA expression on day 28 (P < 0.05). Flow cytometric analysis, however, revealed that the expression levels of both CCR4 and CCR5 were low at birth. Thus, CCR4(+) CD4(+) cells were significantly increased from days 0-28 (P < 0.05), while CCR5(+) CD4(+) cells were not. Increased IL-4 and TGF-beta synthesis as well as increased CCR4(+) CD4(+) cells suggest that, under extra-maternal circumstances, there is a shift in bias toward Th2 responses even in preterm infants soon after delivery, while they may be capable of developing Th1 mediated responses soon after birth.

Actins↗
PubMed2004

Hyperbaric oxygenation therapy for simple adhesive postoperative intestinal obstruction in children: comparison of the use of a short tube versus a long tube.

We hypothesized that hyperbaric oxygenation (HBO) combined with a long tube (LT) [HBO + LT] would be more effective than HBO combined with a short tube (ST) [HBO + ST] for simple adhesive postoperative intestinal obstruction (APIO) in children, assuming that there is synergism between HBO and LT. The objective of this study was to determine retrospectively the effect of HBO + LT compared to HBO + ST for simple APIO in children. Seventy-three patients were diagnosed with simple APIO, and 51 of these patients were treated with HBO + LT during 104 HBO sessions, while 22 were treated with HBO + ST during 34 HBO sessions. HBO was performed at a pressure of 2 atmospheres for 60 minutes once daily. The recovery rates after HBO therapy were 87.5 % for the HBO + LT group and 82.4 % for the HBO + ST group (p = 0.4496). HBO was performed 5 +/- 3 (range 1 to 15) times for the HBO + LT group and 4 +/- 2 (range 1 to 8) times for the HBO + ST group (p = 0.9847) for ultimate recovery from simple APIO. The recovery rate after HBO therapy of up to 6 sessions was 78.2 % for HBO + LT and 92.1 % for HBO + ST (p = 0.0360) among the cases that recovered ultimately. The effect of HBO + LT did not significantly differ from that of HBO + ST, but the insertion of an LT is more intricate and the cost is higher than that of an ST. Therefore, we conclude that the use of an LT is not necessarily required for HBO therapy for simple APIO.

Child↗
PubMed2004

Cytokines in the gastric mucosa of children with Helicobacter pylori infection.

AIM: Few studies have looked at the cytokine profile in gastric mucosa in children with Helicobacter pylori infection. This study investigated cytokines and their effects on histological abnormalities in the gastric mucosa of children with H. pylori infection. METHODS: The levels of interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and IL-8 proteins were measured in biopsy specimens from the gastric antrum and corpus of children with H. pylori infection, and related to inflammatory cell infiltrations. RESULTS: The antral and corporal mucosal levels of IFN-gamma and IL-8 proteins were significantly higher in children with H. pylori infection than in uninfected children, but there was no such difference in the levels of IL-4 protein. The antral mucosal level of IL-8 protein was significantly higher than the corporal mucosal level of IL-8 protein in the infected children. Inflammatory cell infiltration was significantly higher in the infected children than in the uninfected children, but there were no significant correlations between mucosal cytokine levels and inflammatory cell infiltrations. CONCLUSION: The results suggest that the predominant Th1 cytokine response and enhanced IL-8 production in the mucosa may be involved in the gastric inflammation seen in children infected with H. pylori, as well as in adult patients.

Adolescent↗
PubMed2003

Extirpation of mass-screened adrenal neuroblastomas by retroperitoneoscopy.

BACKGROUND: A mass-screened neuroblastoma (MSN) shows low-grade malignancy. Although the tumor is small, open laparotomy requires a large incision. PURPOSE: Extirpation by retroperitoneoscopy (ER) was performed in children with MSN to reduce the surgical stress. METHODS: The indications for ER were (1) MSN originating from the adrenal gland and (2) a tumor size of less than 4 cm. Between January 2000 and June 2002, 6 children (mean age: 8.5 +/- 0.6 months) underwent ER. RESULTS: All children successfully underwent ER and no conversion of laparoscopy to open surgery was required. The only complication in one patient was a peritoneal tear. Oral intake was possible in all children the day after the operation. No port site metastasis or local recurrence was observed during follow-up (15 to 29 months). CONCLUSIONS: Adrenal MSN less than 4 cm were successfully extirpated by ER. This method has the advantage of allowing patients an early return to eating and has no risk of postoperative ileus. ER is an available surgical technique for children with MSN less than 4 cm.

Adrenal Gland Neoplasms↗
PubMed2003

Multicystic dysplastic kidney detected by prenatal ultrasonography: natural history and conservative management.

Conservative management of multicystic dysplastic kidney (MCDK) without nephrectomy has recently been advocated. The purpose of this study was to determine the clinical course of conservatively managed unilateral MCDK detected prenatally. Between 1991 and 2001, ten children (three boys and seven girls) with unilateral MCDK detected by prenatal ultrasonography (US) were prospectively followed at our institution. At birth, US confirmed the prenatal findings in all cases. All patients underwent voiding cystourethrography, intravenous pyelography, and radionuclide scans. Postnatal follow-up US examinations were performed every 3 months until patients were 5 years old and annually from then forward. The mean age at diagnosis during the prenatal period was 29 weeks of gestation (range 21-38 weeks). Median follow-up time was 42 months (range 17-125 months). Follow-up US was performed in eight children; three (38%) showed partial resolution, three (38%) complete resolution, and two (24%) no change in cyst size. The mean age at complete resolution of the lesion was 23 months (range 9-33 months). No children developed hypertension or tumors, and all maintained normal growth. In the present study, the natural history of MCDK was benign, and serial US monitoring showed that the affected kidneys frequently showed resolution with time. The results of this study support the conclusion that a nonsurgical approach for patients with MCDK is advisable.

Child, Preschool↗
PubMed2003

Longitudinal study of auditory brainstem response in leigh syndrome.

To assess the utility of auditory brainstem response (ABR) in diagnosing brainstem changes in patients with Leigh syndrome (LS), we performed a longitudinal study of five patients with LS using both ABR and neuroimaging techniques (CT and MRI). The brainstem components of the initial ABRs we performed on the patients were abnormal in all five patients. In four of the patients, these abnormal findings preceded any clinical signs of brainstem impairment. Improvements in clinical findings were reflected in improvements in ABR findings in three patients. In one of these three patients, improvements in clinical findings were also reflected in improvements in MRI findings. In the other two patients, MRI findings showed no improvements, despite the improvements in clinical findings. In two of our patients, ABR clearly revealed functional improvements in the brainstem which were not revealed by MRI. Therefore, we conclude that ABR is an essential diagnostic technique for patients with LS.

Adolescent↗
PubMed2002

Management of blunt hepatic injury in children: usefulness of emergency transcatheter arterial embolization.

We reviewed our experience to determine the usefulness of emergency transcatheter arterial embolization (TAE) for severe blunt hepatic injury (BHI) in children. Between 1978 and 2000, 21 children with BHI (14 boys and 7 girls, ranging in age from 2 to 14 years) were managed according to our protocol. The patients who were hemodynamically stable, and had no other associated injury requiring laparotomy, regardless of the hepatic injury grade, were managed nonsurgically. Emergency angiography and TAE performed after a CT scan revealed extravasation of the contrast medium. Of the 21 patients, 3 underwent emergency laparotomy; 2 due to hemodynamic instability despite fluid resuscitation (1 died), and the 3rd patient because of associated injury. The other 18 patients (86%) were initially managed nonsurgically; however, 2 underwent delayed laparotomy because of complications (1 each of suspected delayed hepatic hemorrhage and liver abscess). Nonsurgical management was completed in the remaining 16 (89%) with no morbidity and mortality. Two of the 16 returned to a hemodynamically stable condition with fluid resuscitation, but were compromised with persistent hepatic hemorrhage, and were successfully treated with emergency TAE. We propose that emergency TAE should be considered as an initial treatment for severe BHI in children.

Adolescent↗
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↗