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Biomedical subjects

T Shono

Publications and source records attributed to T Shono.

At least 19 recordsLinked to original sources
PubMed2005

Spatio-temporal analysis by voltage topography of ictal electroencephalogram on MR surface anatomy scan for the localization of epileptogenic areas.

A 15-year-old girl developed intractable epilepsy following a right transcallosal resection of the intraventricular teratoma. Magnetic resonance (MR) imaging showed a T (2)-prolonged subcortical lesion in the right frontal lobe as well as a residual intraventricular tumor. The integration of the voltage topography of ictal onset activities of the scalp-recorded electroencephalogram (EEG) and a surface anatomy scan of MR images clearly revealed the epileptogenic area on the cortex above the subcortical lesion, with the propagation pattern towards the frontopolar area. Excision of the epileptogenic cortex and underlying gliosis resulted in a successful cessation of the epilepsy. This non-invasive EEG technique provided useful information that accurately localized the epileptogenic area on a large structural abnormality without invasive intracranial electrocorticographic monitoring.

Adolescent↗
PubMed2005

Esophageal atresia with double tracheoesophageal fistula--a case report and review of the literature.

Esophageal atresia with double tracheoesophageal fistula (TEF) is a very rare anomaly, and the accurate preoperative diagnosis of proximal TEF is very difficult. This paper describes a baby girl who presented with esophageal atresia with double, proximal, and distal TEF. The distal TEF was diagnosed before operation, whereas the proximal TEF was found intraoperatively. Overlooking the presence of proximal TEF can lead to increased morbidity and mortality due to severe respiratory infection and the necessity of a second operation. Great care must therefore be taken to not overlook the presence of proximal TEF in patients with this anomaly.

Esophageal Atresia↗
PubMed2005

A case of novel de novo paired box gene 6 (PAX6) mutation with early-onset diabetes mellitus and aniridia.

BACKGROUND: Paired box gene 6 (PAX6) is a transcription factor involved in eye development. Mutations of PAX6 cause congenital eye anomalies, such as aniridia. PAX6 is also involved in the development of the endocrine pancreas, and reported to be a genetic factor common to aniridia and glucose intolerance, although the latter is usually mild. Here, we describe a case of PAX6 mutation with early-onset diabetes mellitus. CASE REPORT: A 27-year-old woman was referred to our clinic. She was diagnosed having diabetes at the age of 15 with negative glutamic acid decarboxylase (GAD) antibody. Insulin treatment was started at age 24. Because she had aniridia, PAX6 gene mutation was investigated and a heterozygous 2-bp deletion (c.402del2) was identified. Her parents did not have aniridia and PAX6 mutations. Heterozygous PAX6 mutation may cause glucose intolerance. However, cases of early-onset diabetes mellitus have not been reported. Her parents did not have diabetes, but their insulinogenic indices were low (0.25 and 0.3, respectively). We thought her early-onset diabetes was partly as a result of PAX6 mutation and partly because of an unknown insulin secretory defect inherited from her parents. We could not find any mutations in HNF-1alpha, -1beta, -4alpha, IPF-1, ISL-1, BEAT2/NeuroD1, PAX4, and amylin genes. CONCLUSIONS: We report a case of PAX6 gene mutation with early-onset diabetes mellitus and aniridia. Low insulin secretory capacity in her parents suggested that her insulin secretory defect is as a result of not only PAX6 mutation but other genetic factors inherited from her parents.

Adult↗
PubMed2004

Short-time exposure to vinclozolin in utero induces testicular maldescent associated with a spinal nucleus alteration of the genitofemoral nerve in rats.

BACKGROUND/PURPOSE: Vinclozolin (V), a known antiandrogen, has been used widely to protect fruits, vegetables, and turf from fungus damage. The aim of this study was to clarify the effect of V on both the development of the spinal cord nucleus and testicular descent in rats. METHODS: Pregnant rats were administered 200 mg/kg/d of V from day 16 to 18 of gestation. At 5 days of age, the genitofemoral nerve (GFN) of male pups was identified on the psoas muscle, and diamidinophenyl indole was applied to the proximal cut end of the GFN. Forty-eight hours later, the T11 to L4 level of the spinal cord was removed, and 30-microm frozen serial sections were made. Next, the spinal nuclei labeled in a retrograde fashion by diamidinophenyl indole (DAPI) were examined with a fluorescence microscope. Additional male pups survived until 60 days of age to evaluate the position of the testes. RESULTS: The size of the DAPI-labeled spinal nuclei were smaller in the V-treated rats than in the control rats. The average number of the DAPI-labeled spinal nuclei decreased significantly more in the V-treated rats (176+/-33) than in the controls (247+/- 21; P <.05) during the newborn period. At 60 days of age, 15 of the 26 male rats showed either unilateral or bilateral undescended testes in the V-treated rats. The incidence of cryptorchidism was also significantly higher in the V-treated rats (57.7%) than in the controls (0%; P <.05). CONCLUSIONS: The antiandrogenic effect of the prenatal administration of V inhibited the development of the GFN nucleus in the spinal cord and induced testicular maldescent in rats. These results support the hypothesis that androgens regulate the descent of the testis through GFN development.

Androgen Antagonists↗
PubMed2004

The effect of a prenatal androgen disruptor, vinclozolin, on gubernacular migration and testicular descent in rats.

BACKGROUND/PURPOSE: Androgen has been shown to regulate inguinoscrotal testicular descent. This study aims to clarify the effect of one of the major endocrine disrupters, vinclozolin (V), on both gubernacular migration and inguinoscrotal testicular descent in rats. METHODS: Time-pregnant rats were segregated into 2 groups. In group I, the rats were administered 200 mg/kg/d of V by gavage on days 15 to 18 of gestation. In group II, the rats were administered the same volume of solvent and were used as controls. At birth, the anogenital distance was measured in pups, and gubernacular migration was examined at 10 days of age in some of male offspring. Next, the incidence of testicular descent and the growth of external genitalia were investigated in the remaining male offspring at 60 days of age. The chi2 test was used for statistical analysis of the results. RESULTS: At birth, the anogenital distance (AGD) index decreased significantly more in group I than in group II in male offspring. However, there was no significant difference in the AGD index between the 2 groups in the female offspring. At 10 days of age, an aberrant migration of the gubernaculum was found in the 51.5% of V-treated rats in group I. At 60 days of age, the incidence of cryptorchidism was 57.7% in group I and 0% in group II (P <.05). In addition, hypospadias with cleft phallus and pseudo vagina with a blind pouch also were observed in some of the V-treated rats. CONCLUSIONS: Prenatal administration with V thus caused intrauterine defects, which resulted in testicular maldescent caused by the induction of an aberrant migration of the gubernaculum associated with an abnormal extension of the processus vaginalis, and this may have been caused by the antiandrogenic effect of V in utero.

Androgen Antagonists↗
PubMed2003

Disturbed pituitary-testicular axis inhibits testicular descent in the prenatal rat.

OBJECTIVE: To investigate whether prenatal stress affects the pituitary-testicular axis in relation to testicular descent in rat fetuses, as maternal stress can alter the plasma testosterone concentration and inhibit testicular descent in male rat fetuses. MATERIALS AND METHODS: Pregnant rats were divided into two groups and kept in reverse light-dark cycles, with lights-off at 08.00 hours and on at 20.00 hours. In group 1, 15 pregnant females were placed three times daily for 60 min each session in plastic rat-holders (13 x 6 x 8 cm) illuminated by two 150-W flood lights during the dark phase, from day 14 to 18 of gestation. In group 2, 10 pregnant females were not handled and thus were used as controls. At 19 days of gestation, five pregnant rats had a Caesarean section in each group, and both testes and the pituitary gland were removed from male fetuses at 10.00-11.00 hours. The tissue homogenates were analysed for testicular testosterone and pituitary luteinizing hormone (LH) by a radioimmunoassay. Thereafter, at 21 and 30 days of age, testicular descent was assessed in the remaining male offspring. Student's t- and the chi-square test were used to assess the results. RESULTS: The mean (sd) concentration of fetal testicular testosterone was significantly lower in group 1, at 312.9 (26.2) pg/mg, than in group 2, at 532.5 (18.2) pg/mg (P < 0.05); that of pituitary LH was also significantly lower in group 1, at 130.6 (22.7) and 295.6 (35.2) pg/mg, respectively (P < 0.05). The completion rate of testicular descent was 14% in group 1 (36 male rats) and 64% in group 2 (28 male rats) at 21 days old, and thereafter they were 81% and 100%, respectively, at 30 days old (P < 0.05). CONCLUSION: Maternal stress might inhibit the pituitary-testicular axis, thereby resulting in abnormal testicular descent in male fetuses.

Animals↗
PubMed2001

Inhibition of FGF-2-mediated chemotaxis of murine brain capillary endothelial cells by cyclic RGDfV peptide through blocking the redistribution of c-Src into focal adhesions.

The alpha(v)beta(3) integrin is essential for fibroblast growth factor (FGF)-induced angiogenesis in vivo. However, the role of this integrin in FGF-2-mediated cellular responses by cultured endothelial cells is largely unknown. Cyclic RGDfV (cRGDfV) peptide is widely used to inhibit the binding of alpha(v)beta(3) integrin to vitronectin. To investigate the role of this integrin in FGF-2-mediated cellular responses, we used immortalized murine brain capillary endothelial cells, denoted IBE cells. Because IBE cells proliferate and migrate in response to FGF-2-treatment, when cultured on fibronectin-coated surface, we first examined the inhibitory activity of this peptide on the binding of alpha(v)beta(3) integrin to fibronectin as well as vitronectin. Solid phase binding assay revealed that cRGDfV peptide strongly inhibited the binding of purified alpha(v)beta(3) integrin to vitonectin- and fibronectin-coated plastic surfaces at a concentration of 50 microM. cRGDfV peptide at 50 microM inhibited spreading as well as adhesion of IBE cells on vitronectin-coated plastic surface but not on fibronectin. On fibronectin-coated substrata, cRGDfV at 50 microM attenuated FGF-2-mediated chemotaxis, but not FGF-2-induced proliferation, of IBE cells. We have previously demonstrated that mitogen-activated protein kinase (MAPK) activation within focal adhesions through c-Src activity was involved in FGF-2-induced chemotaxis of IBE cells. Treatment of cells with cRGDfV peptide was associated with reduced c-Src activity without tyrosine dephosphorylation. Immunofluorescent staining showed that cRGDfV inhibited redistribution of c-Src into focal adhesions. MAPK activation by FGF-2 within focal adhesions was also attenuated in the presence of cRGDfV peptide. Our results indicated that cRGDfV peptide inhibited redistribution of c-Src into focal adhesions, leading to impaired MAPK activation within focal adhesions and motility in FGF-2-treated endothelial cells.

Angiogenesis Inhibitors↗
PubMed2001

Cyclooxygenase-2 expression in human gliomas: prognostic significance and molecular correlations.

Cyclooxygenase (COX)-2, the inducible isoform of prostaglandin H synthase, has been implicated in the growth and progression of a variety of human cancers. Although COX-2 overexpression has been observed in human gliomas, the prognostic or clinical relevance of this overexpression has not been investigated to date. In addition, no study has analyzed the relationship between COX-2 expression and other molecular alterations in gliomas. Consequently, we examined COX-2 expression by immunohistochemistry in tumor specimens from 66 patients with low- and high-grade astrocytomas and correlated the percentage of COX-2 expression with patient survival. We also analyzed the relative importance of COX-2 expression in comparison with other clinicopathological features (age and tumor grade) and other molecular alterations commonly found in gliomas (high MIB-1 level, p53 alteration, loss of retinoblastoma (Rb) protein or p16, and high bcl-2 level). Kaplan-Meier analyses demonstrated that high COX-2 expression (>50% of cells stained positive) correlated with poor survival for the study group as a whole (P < 0.0001) and for those with glioblastoma multiforme in particular (P < 0.03). Cox regression analyses demonstrated that COX-2 expression was the strongest predictor of outcome, independent of all other variables. In addition, high COX-2 expression correlated with increasing histological grade but did not correlate with positive p53 immunostaining, bcl-2 expression, loss of p16 or retinoblastoma protein expression, or high MIB-1 expression. These findings indicate that high COX-2 expression in tumor cells is associated with clinically more aggressive gliomas and is a strong predictor of poor survival.

Adolescent↗
PubMed2001

The role of mitogen-activated protein kinase activation within focal adhesions in chemotaxis toward FGF-2 by murine brain capillary endothelial cells.

Fibroblast growth factors (FGFs) regulate a number of angiogenic cellular responses such as migration of endothelial cells. To examine the role of mitogen-activated protein kinase (MAPK) in endothelial cell migration, chemotaxis toward FGF-2 was determined in murine brain capillary endothelial cells, denoted IBE cells. PD98059, a specific inhibitor for MAPK/Erk kinase, inhibited FGF-2-induced chemotaxis of IBE cells. It has been reported that c-Src tyrosine kinase phosphorylates focal adhesion kinase at tyrosine 925 within focal adhesions, which in turn creates the binding site for Grb2, leading to MAPK activation. The Src family tyrosine kinase inhibitor, PP1, as well as overexpression of kinase-inactive c-Src, attenuated chemotaxis toward FGF-2. To investigate the signaling events involved in FGF-2-induced chemotaxis, MAPK activation was monitored in IBE cells by indirect immunofluorescence staining. Activated MAPK was initially observed in the cytoplasm and gradually moved into nuclei. A fraction of MAPK was activated by FGF-2 within focal adhesions, where FGF receptor-1 and Src family kinases were also colocalized. MAPK activation within focal adhesions was remarkably decreased in kinase-inactive c-Src-expressing IBE cells. Our data suggest that activation of MAPK by FGF-2 within focal adhesions may depend on c-Src activity and is crucial for FGF-2-induced migration of IBE cells.

Animals↗
PubMed2001

Room-temperature ferromagnetism in transparent transition metal-doped titanium dioxide.

Dilute magnetic semiconductors and wide gap oxide semiconductors are appealing materials for magnetooptical devices. From a combinatorial screening approach looking at the solid solubility of transition metals in titanium dioxides and of their magnetic properties, we report on the observation of transparent ferromagnetism in cobalt-doped anatase thin films with theconcentration of cobalt between 0 and 8%. Magnetic microscopy images reveal a magnetic domain structure in the films, indicating the existence of ferromagnetic long-range ordering. The materials remain ferromagnetic above room temperature with a magnetic moment of 0.32 Bohr magnetons per cobalt atom. The film is conductive and exhibits a positive magnetoresistance of 60% at 2 kelvin.

Journal Article↗
PubMed2001

The biological effect of phthalate esters on transabdominal migration of the testis in fetal rats in comparison with the antiandrogen flutamide.

Phthalate esters are commonly used as plasticizers for polyvinyl chloride and are known to be hormone-disrupting chemicals. We previously reported that mono-n-butyl phthalate (MBP) administered to rat fetuses induced cryptorchidism postnatally. The aim of this study was to investigate the biological effect of MBP on the transabdominal migration of the testis in prenatal rats by comparing this with the prenatal effect of the antiandrogen flutamide on testicular descent. Time-pregnant Wistar King A rats were divided into three groups: group I rats (N = 3) were administered MBP 0.3 g/day by gavage from gestational days 15 to 18; group II rats (N = 3) were injected with flutamide (30 mg/day) from gestational days 15 to 18; group III rats (N = 3) were administered solvent as controls. On the 19th gestational day, all rats underwent a cesarean section and the male fetuses were dissected to examine the position of the testis, which was significantly higher in the abdominal cavity in the MBP-treated rats than in either the flutamide-treated or control rats. No significant difference was observed in the position of the testis between the flutamide-treated and control rat fetuses. Our findings suggest that maternal MBP prevented transabdominal migration of the testis in prenatal rats, which may not have been due to either an antiandrogenic or estrogenic effect of MBP, but to a direct toxic effect of MBP on the testis.

Animals↗
PubMed2001

Fenitroxon insensitive acetylcholinesterases of the housefly, Musca domestica associated with point mutations.

The cDNA of AChE in the housefly, Musca domestica, was sequenced and individual flies were genotyped by this gene in an inhibition assay of AChE activity with an organophaspate, fenitroxon. Mutations at Gly(342) and Tyr(407), which are reportedly conserved in resistant strains of Drosophila, were associated with the insensitivity to fenitroxon. Two other mutations, Ile(162) and Val(260), did not have an apparent effect on insensitivity. However, the four mutations are located in the active site of the enzyme, and therefore the non-neutral mutations in this gene are considered to cause the insensitivity of AChE in the development of insecticide resistance of the housefly.

Acetylcholinesterase↗
PubMed2001

Vascular endothelial growth factor in chronic subdural haematomas.

OBJECTIVE: To elucidate molecular aspects of the mechanisms of expansion of chronic subdural haematomas (CSH), we examined the expression of two representative angiogenic factors, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in CSH. METHODS: We quantified VEGF and bFGF in haematoma fluid and serum of 20 patients with CSH using an enzyme-linked immunosorbent assay. Mean concentrations of VEGF in the haematoma fluid (10277 pg/ml) and in serum, (355 pg/ml) were much greater than those of bFGF (haematoma, 3.04 pg/ml; serum, 4.74 pg/ml). Surgical specimens, including dura and the outer membrane of the CSH were analysed by in situ hybridisation to detect VEGF mRNA. Macrophages and vascular endothelial cells in the outer membrane over expressed VEGF mRNA. CONCLUSIONS: Enhanced production of VEGF by macrophages and vascular endothelial cells in the outer membrane is thought to be pathogenetically important in CSH.

Adult↗
PubMed2001

Possible horizontal transfer of a transposable element from host to parasitoid.

Full-length mariner-like elements (MLEs) were identified from both a parasitoid wasp, Ascogaster reticulatus, and its moth host, Adoxophyes honmai. MLEs were detected in two related Tortricid moths, but not in another Ascogaster species. The MLEs of A. reticulatus and A. honmai were 97.6% identical in DNA sequence. This high similarity suggests a recent horizontal transfer, probably from the moth host to the wasp parasitoid, facilitated by the intimacy of the host-parasitoid relationship.

Amino Acid Sequence↗
PubMed2001

Mulberry moracins: scavengers of UV stress-generated free radicals.

Mulberry leaves treated with UV-C were found to accumulate three different phytoalexins, moracin C, moracin N, and chalcomoracin. The increased level of malondialdehyde in UV-treated leaves along with moracins suggested their role as a free-radical scavenger in stressed plants. All the three moracins induced under UV stress were capable of scavenging the superoxide anion generated by the xanthine-xanthine oxidase system. Also, moracins were capable of inhibiting lipid peroxidation, which strongly indicates their role as a scavenger.

Free Radical Scavengers↗
PubMed2001

Physiological responses to water-walking in middle aged women.

The purpose of the present study was to examine the physiological responses to water-walking using the Flowmill, which has a treadmill at the base of a water-flume, in two groups of women. In the first group, the women were known to regularly swim and exercise in water (group A), while in the second, they did not routinely participate in water-exercise (group B). In both groups, twelve healthy female volunteers in their fifties participated in the study. All of the subjects walked in water using the Flowmill for the first time. Subjects completed four consecutive bouts of 4-minute duration at progressively increasing speeds (20, 30, 40, and 50 m.min-1), with 1-minute rests between each bout. In addition, water-velocity was adjusted to the walking speed of each bout. The water-depth of the Flowmill was the level of the xiphoid process. The water and room temperatures were 30.3 +/- 0.1 degrees C and 24.9 +/- 0.4 degrees C, respectively. In both groups, the relationship between walking speed and oxygen uptake (VO2) as well as that between walking speed and heart rate (HR) changed exponentially as the walking speed increased, and the relationship between HR and VO2 was linear. The relationship between HR and VO2 was similar in both groups, and there was no significant difference between the predicted maximal oxygen uptake (VO2max) of the two groups. VO2 and HR of group B during water-walking, however, were significantly higher than those of group A at all walking speeds. The results of this study clearly showed that experience in moving through the water strongly affects physiological responses to water-exercise, even when fitness levels are equivalent.

Anthropology, Cultural↗
PubMed2001

Thermoregulatory responses to low-intensity prolonged swimming in water at various temperatures and treadmill walking on land.

The purpose of the present study was to examine the effect of water temperature on the human body during low-intensity prolonged swimming. Six male college swimmers participated in this study. The experiments consisted of breast stroke swimming for 120 minutes in 23 degrees C, 28 degrees C and 33 degrees C water at a constant speed of 0.4 m.sec-1 in a swimming flume. The same subjects walked on a treadmill at a rate of approximately 50% of maximal oxygen uptake (VO2max) at the same relative intensity as the three swimming trials. Rectal temperature (Tre) in 33 degrees C water was unchanged during swimming for 120 minutes. Tre during treadmill walking increased significantly compared to the three different swimming trials. Tre, mean skin temperature (Tsk) and mean body temperature (Tb) in 23 degrees C and 28 degrees C water decreased significantly more than in both the 33 degrees C water and walking on land. VO2 during swimming in 23 degrees C water increased more than during swimming in the 28 degrees C and 33 degrees C trials; however, there were no significant differences in VO2 between the 23 degrees C swimming trial and treadmill walking. Heart rate (HR) during treadmill walking on land increased significantly compared with HR during the three swimming trials. Plasma adrenaline concentration at the end of the treadmill walking was higher than that at the end of each of the three swimming trials. Noradrenaline concentrations at the end of swimming in the 23 degrees C water and treadmill walking were higher than those during the other two swimming trials. Blood lactate concentration during swimming in 23 degrees C water was higher than that during the other two swimming trials and walking on land. These results suggest that the balance of heat loss and heat production is maintained in the warm water temperature. Therefore, a relatively warm water temperature may be desirable when prolonged swimming or other water exercise is performed at low intensity.

Adolescent↗