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Toshihiro Horiguchi

Publications and source records attributed to Toshihiro Horiguchi.

18 recordsLinked to original sources
PubMed2005

["Early" diagnosis and "early" intervention in children with mental retardation--when is early enough to diagnose them?].

Patients with mental retardation (MR) cannot always be diagnosed accurately by physicians who are specialized in child neurology and/or developmental disorders at their first visit to the clinic. Precise examination such as psychological tests and chromosomal analysis are often necessary to diagnose them. Some patients with autistic disorders without MR often are misdiagnosed as having MR. Patients with mild to moderate MR are sometimes diagnosed late in their late teens or twenties. Timely diagnosis and timely/continuous intervention is more important than early diagnosis and early intervention for the mentally retarded.

Adult↗
PubMed2004

Involvement of the retinoid X receptor in the development of imposex caused by organotins in gastropods.

Organotin compounds released from antifouling paints, such as tributyltin (TBT) and triphenyltin (TPT), are potent inducers of imposex (a superimposition of male genital tracts, such as penis and vas deferens, on females) in marine gastropods. Little is known about the induction mechanism of gastropod imposex. Here, we show that organotins bind the human retinoid X receptors (hRXRs) with high affinity and that injection of 9-cis retinoic acid (RA), the natural ligand of hRXRs, into females of the rock shell (Thais clavigera) induces the development of imposex. Cloning of the RXR homologue from T. clavigera revealed that the ligand-binding domain of rock shell RXR was very similar to vertebrate RXR and bound to both 9-cis RA and to organotins. These suggest that RXR plays an important role in inducing the development of imposex, namely, the differentiation and growth of male genital tracts in female gastropods.

Animals↗
PubMed2004

Human auditory evoked mismatch field amplitudes vary as a function of vowel duration in healthy first-language speakers.

Previous auditory studies demonstrated that vowel shortening elicited a more prominent mismatch component than its lengthening in event-related potentials (ERP) and magnetoencephalography (MEG). Based on these findings, the current study investigated whether the magnetic mismatch field (MMF) component would be generated by vowel shortening of various degrees to determine a neuronal response threshold of pre-attentive deviation detection. Behavioral pre-test data revealed that while listening to Japanese short-duration (100%: reference), long-duration (180%), and other in-between duration-synthesized types, healthy native speakers of Japanese failed to clearly categorize 140-124% durations as either short or long words, while categorizing 108-116% durations as short words and 148-172% durations as long. Following these results, MEG responses were recorded with a whole-head 148-channel magnetometer, as subjects listened to 100% standard and five deviant durations (124, 132, 140, 148, 180%). MEG results showed that the above-32% duration decrements (180-->100%, 148-->100%) elicited a more prominent MMF than the others, the MMF amplitudes increasing linearly to the degree of duration deviance, and that neuronal responses correlated with behavioral word-categorization accuracy.

Acoustic Stimulation↗
PubMed2004

Numerical simulation of organic chemicals in a marine environment using a coupled 3D hydrodynamic and ecotoxicological model.

For ecotoxicological risk assessment in a marine ecosystem, we constructed a coupled three-dimensional hydrodynamic and ecotoxicological model (EMT-3D), and applied it to Tokyo Bay. The model was calibrated with field data obtained in 2002. The results of sensitivity analysis for dissolved Bisphenol A showed that biodegradation rate was the most important factor for concentration change. Bioconcentration coefficient was the most important factor for Bisphenol A in phytoplankton. Therefore, the parameters must be carefully considered in the modeling. The mass balance results showed that standing stocks of Bisphenol A in water, in particulate organic carbon and in phytoplankton are 7.85 x 10(4), 1.78 x 10(2) and 3.44 x 10(-1) g, respectively. With respect to flux, biodegradation in the water column had the highest value of 1.06 x 10(3) g/day, and next were effluent to the open sea, partition to particulate organic carbon, and bioconcentration in phytoplankton.

Benzhydryl Compounds↗
PubMed2004

[Guidelines for medical examination of children with mental retardation in pediatric clinics which are specialized for developmental disorders--recommendation based on the current selection and usefulness of diagnostic examinations for children with mental retardation and/or pervasive developmental disorder].

We assessed the present status of choice and usefulness of medical examinations of children with mental retardation (MR) and/or pervasive developmental disorder (PDD). Children with severe MR received more examinations than those with mild MR. Many abnormal findings were demonstrated by MRI in cases of severe MR. Cases of PDD without MR rarely showed abnormal results. Cases of PDD with MR underwent fewer examinations, but showed more abnormal results. We presented guidelines regarding medical examinations for children with MR in pediatric clinics which are specialized for developmental disorders, including psychological tests, hearing tests, EEG, genetic tests and neuroimaging. Physicians should select appropriate medical examinations based on evidence. The goal of testing is to provide useful information concerning medical treatment, therapeutic rearing, and education, and to support patients and their families in cooperation with relevant facilities.

Child↗
PubMed2004

[Assessment of social networks between developmental physicians and welfare facilities/specialists for children with intellectual disabilities in Japan].

The social networks between Japanese child neurologists and welfare facilities/specialists for children with mental retardation (MR) were assessed. A total of 113 physicians answered our mail-in questionnaire. Most of the doctors had various connections with nursery homes for children with MR or severe motor and intellectual disabilities (SMID) and with public health centers, and often collaborated with teachers of schools and kindergartens. On the other hand, most physicians had little relation with residential and vocational facilities for adults with MR, and with specialists in residential or community care. There was a statistical correlation between the number of facilities or collaborated specialists and the number of persons seen by each physician; however, the physicians' experience and affiliations had no relation. In view of 'social participation', physicians who usually see children with developmental disorders can play an important role in decision making of their life-style with their families.

Child↗
PubMed2004

[Abnormal findings of dichotic listening test in patients with childhood adrenoleukodystrophy].

Ten Japanese boys with childhood-onset adrenoleukoqdystrophy (ALD) were evaluated with dichotic listening test (DLT). Six cases showed abnormal findings especially of laterality index (L.I.) calculated from the score of each ear. Some of them showed no abnormal findings with other auditory examinations containing auditory brainstem responses (ABR). One patient showed abnormal L.I. of DLT at an early stage. The abnormality of laterality index was similar to the so-called "strong left-ear suppression" in patients who underwent callosotomy. Although all of these six patients had a high signal lesion at the splenium of the corpus callosum in a T3-weighted MRI sequence, it was difficult to evaluate the width of demyelinated area. DLT could detect the early damage of connecting fibers mediating inter-hemispheric transfer of auditory information, and might be a useful method for evaluating the cerebral function of auditory processing in patients with childhood ALD.

Adolescent↗
PubMed2004

[Japanese physicians'attitude for utilization of social support services for persons with intellectual disabilities].

We assessed physicians'attitude for the utilization of social (medical, educational, and financial) support services for persons with intellectual disabilities supplied by the Japanese government. A total of 113 physicians specializing in pediatric neurology answered our mail-in questionnaire. Medical care benefits for psychiatric outpatients and short-time stay were the most common services utilized. Whereas most physicians used various public support services regardless of their experience and affiliations, the selection of services by an individual physician correlated with the number and state of patients they usually cared. Physicians were less familiar with the services regarding residential or community care and advocacy. Knowledge of the specialists on each service will enrich assistance appropriate to the life styles of each patient with intellectual disabilities.

Child↗
PubMed2003

An MEG study of P300 activity during a color discrimination task 2: source localization study.

In this study, we described developmental changes in an event-related magnetic source of P300 activity during a visual oddball paradigm using magnetoencephalography. The maximum and minimum points of each peak of target P300 activity were scattered in a more anterior temporal area in children than in adults. The single dipole source analysis successfully estimated a dipole in the vicinity of the thalamus and the cingulate gyrus in adults. The location differed in children, although the dipole had overall greater moment in children than in adults. Our findings suggest that the thalamus plays an important role in generating P300 activity specific to color discrimination processing, and that in children the source is not consistent during development.

Adult↗
PubMed2003

Neuropsychological developmental change in a case with Noonan syndrome: longitudinal assessment.

The authors describe the neuropsychological development of a 10-year-old boy with Noonan syndrome. The subject's IQ showed normal intelligence, although there was a discrepancy between verbal and performance IQs. Visual perception was delayed, with clumsiness and inattention affecting his performance. Both visual perception and hyperactivity improved with the subject's general development, but his inattention seemed to increase after the age of 9. The behavioral features and cognitive profile of our case resembled those of attention-deficit/hyperactivity disorder. We recommend that clinicians should evaluate cautiously the specific profile of cognitive development in Noonan syndrome with particular focus on controlling the patient's inattention.

Attention↗
PubMed2003

An assessment of the mental health of physicians specializing in the field of child neurology.

We assessed physicians working in the field of child neurology with the aim of improving the physicians' mental health. Our questionnaire included a burnout inventory and a general health questionnaire. We analyzed 29 responses from physicians in a variety of countries obtained through the Internet. According to their responses, 8 (27.5%) of the respondents had attained a burnout status, and 27 respondents (93.1%) had neurotic conditions. We found a greater percentage of physicians in poor mental health than we had found previously in assessments made in Japan. However, the respondents in the present survey had more positive styles for coping with stress. The length of time working as a physician affected respondents in Japan and internationally, whereas nationality or working environment (workplace, night shifts, and so on) did not. Consultants or mentors on work and assertive stress coping would be effective.

Adaptation, Psychological↗
PubMed2003

[Assessment of chromosome and gene analysis for the diagnosis of the fragile X syndrome in Japan--estimated prevalence rate in various facilities].

We assessed the present status of chromosome and gene analyses utilized in Japan for the diagnosis of fragile X syndrome. Nursery facilities for the mentally handicapped and hospitals completed a mail-in-questionnaire including information on the number of patients diagnosed with the syndrome, the types of diagnostic analyses used, and the need for such analyses. Among 517 responders, ninety-five (18.4%, more frequently in hospitals) reportedly conducted chromosome or gene analyses, which established the diagnosis of fragile X syndrome in 56 patients, accounting for 2.2% of patients who underwent the analyses, and 0.13% of the patients included in this study. Each responder's experience with chromosome or gene analyses were related to his/her demand for them. Some facilities that had not utilized these analyses requested information on them as well as access to them. A larger number of specialists interested in diagnostic screening are essential to establish a diagnosis system of fragile X syndrome.

Cytogenetic Analysis↗
PubMed2003

[Assessment of the selection and usefulness of diagnostic examinations for children with mental retardation].

We retrospectively investigated medical records of 196 patients suspected of having mental retardation at their initial visits. The objective of the study was to clarify the current choice of medical examinations and to assess their usefulness. Frequently selected examinations included 1. neuroimaging, neurophysiology and other central nervous system examinations, 2. psychological examinations and 3. blood tests. The former two demonstrated abnormal results very frequently. Genetic examinations rarely showed abnormal results. On the contrary, chromosomal analysis was often useful for diagnosing diseases that are difficult to be made only by clinical symptoms. Physicians should provide patients and their families with information about medical examinations currently available and useful.

Child↗
PubMed2002

Auditory perception in auditory neuropathy: clinical similarity with auditory verbal agnosia.

The precise features of auditory perception in patients with auditory neuropathy have not been well described. In the present study, we examined auditory perception in a patient with auditory neuropathy. The patient was a right-handed 7-year-old boy. His chief complaint was delayed speech and suspected of verbal learning disability. He could talk, read and repeat rather fluently but could not understand fully what was asked. V-IQ, P-IQ and F-IQ of Wechsler Scale for Children III-R were 53, 118 and 81, respectively. Pure tone audiogram was completely normal. His speech discrimination ability was very poor. He could identify environmental sounds with visual matching. He could differentiate intensity difference but not time difference. This phenomenon was reported in patients with hemispheric symptoms. These clinical features are very similar to verbal auditory agnosia. ABR showed no response at 90dBnHL alternating clicks and tone bursts. Click evoked and distortion product otoacoustic emissions (OAE) were normal. Electrocochleogram was also normal. Motor and sensory nerve conduction velocity was completely normal. Pa of MLR and N1 of SVR were present. His diagnosis should be "pure type" of auditory neuropathy or auditory nerve disease. Importance of both ABR and OAE examination should be widely announced and auditory neuropathy must be campaigned stressed to be clinical entity among personnel who take care of children with speech delay.

Agnosia↗
PubMed2002

[Early detection and therapeutic rearing for children with mental retardation: I. Assessment of diagnosing examination and collaborative facilities assigned for children with mental retardation].

We assessed medical examinations and therapeutic rearing designed for diagnosing children with mental retardation (MR) taking three cases as an example. One hundred and seven physicians answered the questionnaire. Their tentative diagnoses were tuberous sclerosis, autistic disorder, and mental retardation, respectively. They planned medical examinations of blood cell count, urinalysis, blood biochemistry, developmental questionnaires, CT, MRI, and EEG. They chose speech and occupational therapy, nursery facilities, public health center, social welfare counselors, and parents' associations as their early intervention programs. To enrich social resources for MR children, a network of facilities and training for specialists are necessary.

Child Rearing↗
PubMed2002

[Early detection and therapeutic rearing for children with mental retardation: II. Assessment of gene analyses for the diagnosis of developmental disorders in Japan].

The authors assessed the present status of gene analysis utilized in Japan. Physicians completed a mail-in questionnaire with their comments regarding the types of gene analyses they used, the perceived effectiveness of the analyses, and how they conducted genetic counselling for the patients. Among the 76 physicians who responded, gene analysis was most often conducted (n = 16, 75.0%) for muscle dystrophies, and considered to be effective by most of them (chi 2 (df = 2) = 11.99, p = 0.003). Many factors including the age of physicians, location of their facilities, and experience in child neurology were related to the utilization of gene analyses. Future studies based on ethical guidelines should establish a network between specialists and facilities and encourage medical approach to developmental disorders.

Child↗