Search PubMed⌕ Search

Biomedical subjects

M Kaga

Publications and source records attributed to M Kaga.

At least 73 records · Page 4Linked to original sources
PubMed1995

[A specific disorder of Kanji writing observed in a learning-disabled child--cognitive-psychological and neuropsychological analysis].

We reported a learning-disabled child who demonstrated a specific disorder of Kanji writing. A right-handed 13-year-old boy had showed no abnormality in general intelligence (VIQ114 and PIQ 100 in WISC-R), but could write only 35% of Kanji, which he should have learned six years before. It was necessary to develop a new test battery to detect the symptom which had not been detected using current existing test batteries. In cognitive-psychology, this patient had a retrieval disorder of graphic forms of Kanji. In addition, he showed a disorder in reproduction of complex graphic forms which he was asked to remember. Therefore, it is likely that he had a disorder for both Kanji and complex graphic forms, which is similar to the syndrome of pure agraphia of Kanji in adults.

Adolescent↗
PubMed1994

Radiation-induced hypoplasia of the teeth and mandible. A case report.

Hypoplasia of the mandible and teeth is reported in a 4-year-old boy who had cystic hygroma. At age 7 months he had been treated with 60Co-gamma-radiation (24 Gy to the head and neck, 45 Gy to the mediastinum) followed by surgery. Panoramic and periapical radiographs showed hypoplasia of the roots of the primary canines, molars, and permanent teeth and no evidence of tooth germs. The patient was followed up to age 13 years.

Bone Development↗
PubMed1994

Bradykinin and Met-T-kinin-Leu stimulated PGE2 production by rat macrophage and fibroblast.

T-kininogen degradation and kinin release were observed in rat macrophages cultured under acidic conditions. Bradykinin and Met-T-kinin-Leu (a kinin precursor) stimulated PGE2 production by macrophages and fibroblasts but had no effect on O2- production. PGE2 production by macrophages stimulated with 10 microM bradykinin increased by approximately 148% compared to non-stimulated macrophages (0.47 +/- 0.13 vs 0.31 +/- 0.16 ng 10(6) cells-1 30 min-1), and increased by 161% in stimulated as opposed to non-stimulated fibroblasts (0.50 +/- 0.07 vs 0.31 +/- 0.05 ng 10(5) cells-1 30 min-1). No O2- production was detectable in fibroblasts despite stimulation with PMA, A23187, bradykinin, and Met-T-kinin-Leu. O2- production by macrophages was 4.2 +/- 0.3 and 3.0 +/- 0.2 nmol 10(6) cells-1 min-1 after stimulation with PMA and A23187, respectively, but no O2- production was observed after stimulation with bradykinin or Met-T-kinin-Leu. These data suggest that bradykinin and the kinin precursor are implicated in granulomatous tissue formation and wound healing through arachidonic acid and its metabolites but not through O2-.

Animals↗
PubMed1994

[Mismatch negativity in patients with multiple and severe handicaps].

Mismatch negativity (MMN) of the event related potential (ERP) is generated when patients can discriminate two different kinds of stimuli even if he or she is not conscious of their differences. The authors examined auditory ERPs of passive paradigm in 16 patients with severe multiple handicaps. All patients showed no or scarce clinical response to human voices or environmental sounds. This study investigated whether they showed MMN, since it is hard to evaluate their auditory perception clinically. Auditory stimuli were the tone bursts of 700 and 1,000 Hz in frequency offered at a 4:1 occurrence. Nine of 16 patients showed a definite N2 wave followed by an N 1 wave. The latency of the N 2 wave ranged from 150 to 596 milliseconds after the onset of the target stimuli. This N 2 was considered compatible with mismatch negativity (MMN) in healthy patients. These results suggest that the patients could discriminate subtle difference in two kinds of tones, although their responses to auditory stimuli were very poor.

Acoustic Stimulation↗
PubMed1993

Cloning and characterization of an Eimeria acervulina sporozoite gene homologous to aspartyl proteinases.

A lambda ZapII cDNA library was constructed using mRNA from Eimeria acervulina sporulated oocysts and screened with monoclonal antibodies raised against Eimeria tenella sporulated oocytes. Monoclonal antibody N3C8B12 identified a clone (6S2) potentially encoding an aspartyl proteinase since significant homology with cathepsin D, pepsin and renin proteinases was revealed by sequence comparisons. The 1500-bp cDNA fragment containing the coccidial gene was subcloned into pGEX-FA expression vector, leading to the production of an 80-kDa fusion protein (FA6S2) which was used to immunize rabbits. The anti-FA6S2 rabbit sera revealed a single 43-kDa protein present in Eimeria acervulina, Eimeria tenella, Eimeria maxima and Eimeria falciformis sporulated oocyst antigens. Indirect immunofluorescence and electron microscopy with mAb N3C8B12 localized the putative aspartyl proteinase in the refractile bodies of Eimeria tenella sporozoites.

Amino Acid Sequence↗
PubMed1992

Cytotoxicities of oxides, phosphates and sulphides of metals.

The cytotoxicities of oxides, phosphates and sulphides, which possibly form on dental alloys, were tested using the 'agar method'. The relative magnitudes of the cytotoxicities of these compounds exhibited tendencies similar to those of the metal components in the compounds. In correlation with dental amalgams, zinc oxide was the most cytotoxic, just as with metallic zinc, while tin oxides and mercury oxides exhibited no cytotoxicity. Zinc was the most influential element in the cytotoxicity of dental amalgams. On the other hand, in correlation with Ni-Cr alloys, Co-Cr alloys, and/or stainless steels a chromium oxide and a cobalt oxide showed serious cytotoxicity, whereas the iron oxides were non-cytotoxic. Sulphides, which possibly form on silver alloys, showed cytotoxicity. Oxides and phosphates of titanium and aluminium, and hydroxyapatite, were not cytotoxic, supporting the use of these materials for implants. Not only the valence of an element but also the chemical species combining with the element affect the cytotoxicity of the alloy containing it.

Biocompatible Materials↗
PubMed1992

Congenital focal muscle dysplasia in the lower extremities from probable abnormal innervation: a case report.

A two-year-seven-month-old girl with pes equinovarus congenita, muscle hypotonia and weakness limited to the lower extremities is presented. Upon admission to our hospital, she could stand with support but could not walk alone. Serum creatine kinase level was normal and the electromyogram was nondiagnostic. The muscle CT disclosed an almost total absence of bilateral vastus lateralis and medialis, rectus femoris and gastrocnemius muscles. The biopsied vastus lateralis muscle was almost completely replaced by fat tissue, and a small amount of muscle tissue showed uniform type 1 fiber and an aggregate of atrophic fibers in one fascicle. Because of an absence of progressive muscle weakness and neurogenic EMG findings, the authors conclude that the muscle pathology was due to the congenital anomalous condition of probable abnormal innervation to developing muscles.

Child, Preschool↗
PubMed1992

Development of sound localization.

Perceptual sound localization is determined from differences in time and loudness of signals arriving separately at bilateral ears, with the time difference being the more important one. The author examined the development of sound lateralization using a self-recording device developed by Sato. It measures the sensitivity of sound lateralization on the basis of time and loudness differences separately. Subjects were 59 children aged 2 to 18 years and 12 adults who were audiologically and neurologically normal. Sound stimulus was 500 Hz continuous band noise. (1) The testable rate was increased in children older than the age of 4, and all children over 7 years of age could be tested. (2) Children over 4 years of age could lateralize sound on the basis of time difference. Sensitivity to time differences improved rapidly, showing a steep curve, in children from the ages of 4 to 6, and then increased slowly until adulthood. (3) Sensitivity to loudness differences increased and standard deviation decreased with age. There is a possibility that children aged 4 can discriminate loudness difference almost as well as adults.

Adolescent↗
PubMed1992

[Feeding problems in severely handicapped children].

Nineteen patients with severely handicapped children were divided into 3 groups; tube-fed patients (group 1, n = 8), oral-fed patients with dysphagia (group 2, n = 3) and oral-fed patients (group 3, n = 8). Clinical symptoms, past history, cranial CT, EEG, blink reflex and auditory brainstem response were evaluated in these patients. All patients of group 1 and 2 could not control head or sit by themselves. They needed naso-oral suction. However, nasal airway, intubation and tracheostomy were necessary only in group 1 patients. Five out of 8 patients of group 3 could control head and sit by themselves. No one needed naso-oral suction. CT revealed ventricular dilatation or prominent destructive lesions in group 1. However, patients of group 2 and 3 showed the lesions of mild to moderate degree. EEGs showed poorly developed background activities or electrical status epilepticus in group 1, while they showed relatively well-developed background activities with less prominent paroxysmal discharges in group 2 and 3. R2 component of blink reflex was absent bilaterally in 90% patients of group 1 and 2, while unilateral R2 at least was present in group 3. Feeding problems in severely handicapped children were affected by combination of cerebrum and brainstem involvements. Examination of cranial CT, EEG and blink reflex was useful to determine the method of feeding.

Adolescent↗
PubMed1992

[Development of sound lateralization].

Perceptual sound lateralization is determined from differences in time and loudness of signals arriving separately at bilateral ears, with the time difference being the more important one. The author examined the development of sound lateralization using a self-recording device developed by Sato T, which measures the sensitivity of sound lateralization on the basis of time and loudness differences separately. Subjects were 59 children aged 2 to 18 years and 12 adults who were audiologically and neurologically normal. Sound stimulus was 500 Hz continuous band noise. (1) The testable rate was increased in children older than the age of 4, and all children over 7 years of age could be tested. (2) Children over 4 years of age could lateralize sound on the basis of time difference. Sensitivity to time differences improved rapidly, showing a steep curve, in children from the ages of 4 to 6, and then increased slowly until adulthood. (3) Sensitivity to loudness differences increased and the normal range distribution decreased with age. There is a possibility that children aged 4 can discriminate loudness difference almost as well as adults.

Acoustic Stimulation↗
PubMed1991

Comparison of antimicrobial and cytotoxic effects of glutaraldehyde and formocresol.

The in vitro antimicrobial and cytotoxic concentrations of glutaraldehyde and formocresol were determined. Minimal antimicrobial concentrations of these two agents against selected microbial flora reported in carious primary teeth were 3.125% for glutaraldehyde and 0.75% for formocresol. At a doubling of these concentrations, most organisms, except Candida albicans, Staphylococcus epidermidis, and Streptococcus mutans, were killed by both substances in 30 seconds. Cytotoxicity was evaluated on tissue cultures of pulp fibroblasts and HeLa cells at minimal cidal concentrations and at 10- and 100-fold dilutions. Exposure of pulp fibroblasts and HeLa cells to formocresol and indirect exposure to vapors caused the cells to become atrophic and to form a less dense tissue pattern. Cells directly exposed to glutaraldehyde retained their normal cell shape and tissue pattern, whereas cells indirectly exposed to vapors continued to proliferate. These data showed effective antimicrobial activity at concentrations of 3.125% glutaraldehyde and 0.75% formocresol and suggested that glutaraldehyde may exert a less cytotoxic effect on the immediate and surrounding tissues when used as a pulpotomy agent.

Bacteria↗
PubMed1991

Cytotoxicity of amalgams, alloys, and their elements and phases.

The purpose of this study was to compare the relative cytotoxicity of amalgams, alloys, and their constituent elements and phases, by means of a rapid and sensitive in vitro cell culture test. Pure copper and zinc showed intensive cytotoxicity, significantly greater than that of pure silver and mercury. Pure tin was non-cytotoxic. The gamma-one phase (Ag2Hg3) revealed moderate cytotoxicity, which was significantly decreased by the addition of 1.5% and 5% Sn. However, the addition of 1.5% Zn to gamma 1 containing 1.5% Sn dramatically increased the cytotoxicity of gamma 1 to the same level as that of pure zinc. Whenever zinc was present in amalgams, higher cytotoxicity was revealed. High-copper amalgams showed the same cytotoxicity as a zinc-free low-copper amalgam. The addition of selenium did not reduce the cytotoxicity of amalgam. The cytotoxicity of amalgams was reduced after 24 h. The results of this study suggest that the major contributor to the cytotoxicity of alloy for amalgam is probably copper, while that for amalgam is zinc.

Copper↗
PubMed1991

Giant somatosensory evoked potentials in the Rett syndrome.

Somatosensory evoked potentials (SEP) were recorded in ten patients with the Rett syndrome. Seven cases showed abnormal SEP, and five of these cases showed giant SEP. The five cases with giant SEP were relatively young girls with epilepsy and parieto-central spikes on the electro-encephalogram (EEG). Older patients did not show giant SEP. These giant SEP may be the reflection of cortical hyperexcitability and they may subside as the disease progresses.

Adolescent↗
PubMed1991

[Auditory brainstem response and extratympanic recorded electrocochleography in patients with multiple and severe handicaps].

Nine patients ranged between 5 months and 35 years (means 14 years) of age with multiple and severe disabilities were comparatively studied, on extra-tympanic recorded compound action potential (AP) of electrocochleography and auditory brainstem response (ABR). Both ABR and AP were obvious in 3 patients with clear auditory behavioral responses. The ABR was not recorded to high intensity click stimuli in six patients without visible auditory behavioral responses. Four of the 6 cases showed undetectable AP and the 2 rest of the 6 cases showed abnormal but discernible AP. In two cases with history of the anoxic encephalopathy, AP was recorded but ABR was not detected in one case, and in the other, neither AP nor ABR was recorded. At least two different levels of lesions could be differentiated in cases without detectable ABR by using extra-tympanic recorded electrocochleography in these kinds of severely handicapped patients.

Action Potentials↗
PubMed1990

Studies on pediatric patients with absent auditory brainstem response (ABR) later components.

Eleven pediatric patients with only wave I or waves I and II of their ABR were clinically analyzed. The clinical diagnoses of these patients were as follows: 1) anoxic encephalopathy in two cases; 2) neonatal asphyxia in one; 3) infantile Gaucher's disease in one; 4) mitochondrial encephalomyopathy in one; 5) suspected Pelizaeus-Merzbacher disease in three; 6) degenerative disease of unknown etiology in two (presumptive diagnosis were progressive supranuclear palsy and dentate-rubro-pallido-Luysian atrophy); and 7) infantile spasms with congenital malformation of the brain and bones in one. The incidence of the patients with this type of ABR abnormality was 0.67% among 1,650 of our pediatric patients whose ABRs were examined because of audiological or neurological problems. All eleven patients showed severe mental retardation. Nine of the eleven had convulsions and likewise, eight of eleven showed deterioration in mental and/or motor activities. Furthermore seven of eleven had disturbed consciousness and four of these seven were in deep coma. Other brainstem and bulbar signs and symptoms were frequently found in these patients. In our series, patients without the later components of ABR manifested marked neurological abnormalities inside and outside the brainstem.

Adolescent↗
PubMed1990

[Quantitative evaluation by measuring affected area for cytotoxicity of dental materials].

The agar overlay method was modified and employed in this study to quantitatively evaluate the cytotoxicity of dental materials. The area of fibroblasts affected by the release of toxic substances from tested materials was determined with an image analysis system in order to compare the relative cytotoxicity of amalgams and composite resins. The cytotoxicity of amalgams decreased by 50% or more with aging time. Zinc appeared to be the major contributor to the cytotoxicity of amalgams. The cytotoxicity of chemically cured composite resins was also reduced with hardening time. However, even after 24 hours, the cytotoxicity of all chemically cured composite resins was still apparent. The cytotoxicity of light cured composite resins was dramatically reduced after illumination with the light source. The cytotoxicity of both amalgams and composite resins was strongly dependent upon their hardening process, since aging and curing produced a more stable material which was less likely to release toxic substances into the culture medium. The technique developed in the present study for measuring the area of affected cells to quantitatively evaluate the cytotoxicity of dental materials is simple and reproducible.

Composite Resins↗
PubMed1989

[Correlation between the illumination time and cytotoxicity of light-cured composite resins].

This study was undertaken to compare the relative cytotoxicity of light cured composite resins, and the cytotoxic reduction of light cured composite resins by illumination time by means of in vitro cell culture test. Light cured composite resins (P-30, Silux, Occlusin, Graft LC, Litefil A, Photo Clearfil A, Palfique light and Herculite XR) were filled into glass tubes (4 mm inner dia. x 1 mm high), then illuminated for 0, 10, 20, 30, 40, 50 and 60 seconds through a matrix strip with direct contact ot an Optilux light source (3M), just before testing. Fibroblasts, 2 ml of 1 x 10(5) cells/ml in Eagle's MEM medium supplemented with 10% FCS, penicillin (100 U/ml) and streptomycin (100 micrograms/ml) were evenly seeded on a cover glass in a tissue culture dish and incubated for 24 hours at 37 degrees C in a humidified atmosphere of 5% CO2 in the air. After 24 hours of incubation, the medium was replaced with 2 ml of agar overlay medium consisting of 10% FCS, Eagle's MEM medium and 1.5% agar. Glass tubes (N = 8) filled with the light cured composite resins were placed at the center of the agar, and incubated for 24 hours in 5% CO2 in air at 37 degrees C. After 24 hours of incubation, the cover glass was removed and the cells were fixed in a 10% neutral formalin, then stained with toluidine blue (pH = 9.3) to differentiate the areas of affected and unaffected cells beneath the test specimens. The affected area was quantitatively determined using an image analysis system. The results indicated that there was a high significant reduction in the cytotoxicity of any of the light cured composite resins except Palfique light when light was illuminated. All of the uncured light-cured composite resins revealed a high magnitude of cytotoxicity. However, when composite resin was illuminated, the cytotoxcity of the resin was dramatically reduced, and the longer the light illumination time became, the lesser the cytotoxicity was shown. Palfique light showed a much higher magnitude of cytotoxicity at any light illumination time than any other composite resins. heruclite XR showed less cytotoxicity than Palfique light, however at 60 seconds illumination the cytotoxicity was still shown. The cytotoxicity of composite resins was completely eliminated with illumination times of 50 seconds for P-30, and 60 seconds for Silux. The cytotoxicity of Graft LC, Occlusin and Photo Clearfil A was eliminated with 20 secondlight illumination which showed the least cytotoxicity among the light cured-composite resins tested.(ABSTRACT TRUNCATED AT 400 WORDS)

Cells, Cultured↗