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Biomedical subjects

T Minami

Publications and source records attributed to T Minami.

At least 37 records · Page 2Linked to original sources
PubMed1991

Dynamics of faecal egg counts in rabbits experimentally infected with Strongyloides papillosus.

An experiment using rabbits was carried out to determine basic data to maintain the calf strain of Strongyloides papillosus (SPL). Rabbits treated with four different numbers of doses of dexamethasone were exposed to 50,000 or about 100,000 infective larvae of SPL (Himeji strain, 1988). As a result, faecal egg output was valid in individual rabbits, regardless of dexamethasone administration. Eggs appeared in the faeces 9 or 10 days after exposure, and increased to as much as 20,000-573,000 eggs per gram (EPG). Thirteen of 18 rabbits died (72%) 12-29 days after infection. Five surviving rabbits discharged eggs in their faeces for more than 1 month; however, the EPG value of these cases on the last day was comparatively low.

Animals↗
PubMed1991

Prognostic value of early somatosensory evoked potentials for adverse outcome in full-term infants with birth asphyxia.

SEPs were examined during the first weeks of life in 34 infants with mild to severe birth asphyxia, in an attempt to provide a more accurate prediction of neurodevelopmental outcome. Normal, delayed and absent responses were compared with the infant's acute clinical condition, imaging findings using different imaging techniques and neurodevelopmental outcome. All infants with normal SEPs were normal at follow-up. All but two of the infants with a delayed or absent response died or suffered from severe neurological sequelae. A delayed or absent N1 latency carried a risk for death or severe handicap of 71 and 100%, respectively, compared with 25 and 89% for moderate or severe encephalopathy on neurological assessment, and 29 and 85% for moderate or severe changes seen using different imaging techniques. SEPs may provide useful additional information when assessing the infant with birth asphyxia.

Asphyxia Neonatorum↗
PubMed1991

The late waves of brainstem auditory evoked potentials in children with cerebrovascular diseases.

We examined brainstem auditory evoked potentials (BAEPs) in 28 children with cerebrovascular diseases and 38 normal control subjects and investigated the neuroanatomic correlations of the late waves (VI and VII) of the BAEPs. The patients included 19 patients with moyamoya disease and 9 with other cerebrovascular accidents. Wave VI was more consistently seen (only missing in 2 cases, 5%-2 ears, 3%) than wave VII (missing in 26 cases, 68%-40 ears, 53%) in the control group. Absent, depressed or prolonged wave VI correlated well with cerebral lesions involving internal capsule and basal ganglia, while wave VII had a less significant correlation with any cerebral lesions in children with cerebrovascular diseases.

Adolescent↗
PubMed1991

Oral passive immunization against dental caries in rats by use of hen egg yolk antibodies specific for cell-associated glucosyltransferase of Streptococcus mutans.

The effect of polyclonal egg yolk immunoglobulin G antibodies (yIgG) raised against whole cells, cell-free (CF) glucosyltransferase (GTase), or cell-associated (CA) GTase of serotype c Streptococcus mutans was examined in terms of in vitro inhibition of virulence-related factors of S. mutans and protection of S. mutans-infected rats against the development of dental caries. Hens (18 weeks old) were immunized with formalin-treated whole cells, purified CF-GTase, or CA-GTase together with Freund's complete adjuvant. In addition, yIgG to surface protein antigen was used in some in vitro experiments for comparison with other antibodies. yIgG was purified by ammonium sulfate precipitation followed by DEAE-Sephacel column chromatography or fractional precipitation with ethanol. Purified yIgG was found to be a 220-kDa protein, which was dissociated into heavy and light chains upon addition of 2-mercaptoethanol. yIgG to whole cells and surface protein antigen gave a heavy aggregation of S. mutans organisms, while yIgG to CF- and CA-GTase specifically inhibited the enzymatic activity of the respective GTase. yIgG to CA-GTase and whole cells was found to clearly suppress the adherence of S. mutans cells to a glass surface. Specific-pathogen-free Sprague-Dawley rats that had been infected heavily and repeatedly with S. mutans and fed diet no. 2000 developed severe dental caries, while rats fed diet 2000 containing greater than or equal to 0.1% yIgG to CA-GTase showed a statistically significant reduction in dental plaque accumulation and caries development. Administration of yIgG to CF-GTase and whole cells failed to protect against caries. These results clearly suggest that yIgG to S. mutants CA-GTase specifically inhibited a virulence factor of this organism, i.e., insoluble glucan-synthesizing CA-GTase, resulting in a significant reduction in the development of dental caries.

Administration, Oral↗
PubMed1991

Trehalulose does not induce dental caries in rats infected with mutans streptococci.

The effects of trehalulose, a structural isomer of sucrose, and a syrup (TP syrup) rich in trehalulose and palatinose on caries development were examined in specific pathogen-free Sprague-Dawley rats. Streptococcus mutans MT8148R and Streptococcus sobrinus 6715 fermented the syrup which resulted in acid production, while both strains were found not to utilize trehalulose. Furthermore, trehalulose did not serve as a substrate for glucosyltransferases of these mutans streptococci to synthesize water-insoluble glucan, and it inhibited the sucrose-dependent adherence of mutans streptococci to a glass surface. Although trehalulose induced no significant dental caries in specific pathogen-free rats infected with either MT8148R or 6715, TP syrup was found to induce significant but low dental caries. Furthermore, replacement of the dietary sucrose content with trehalulose resulted in a significant reduction of caries development in rats infected with strain 6715.

Animals↗
PubMed1991

Analysis of protein compositions and surface protein epitopes of Anaplasma centrale and Anaplasma marginale.

Protein composition was compared and epitopes were analyzed among the isolates of Anaplasma centrale and A. marginale by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting using bovine antisera and monoclonal antibodies, and enzyme-linked immunosorbent assay. Common and unique proteins were found among the isolates. All isolates tested had a major surface protein with an apparent molecular weight of 38 to 40 kilodalton which had slight molecular size variations between species. This protein was also a dominant immunogen to the host. At least two species-common epitopes, one of which might contain carbohydrate(s), were present on the major surface protein. One species-specific epitope was identified on the major surface protein of A. marginale isolates.

Anaplasma↗
PubMed1991

[Statistical survey of prosthetic restorations--outline and single crowns, cast cores and inlays].

This is a report on the statistical classification of the prosthetic restorations placed in out-patients of the Tokyo Medical and Dental University Hospital. The data were collected from the laboratory records during the period of January to June of 1986. The results are summarized as follows: 1. The total number of the prosthetic restorations placed in the outpatients were 7355, and 56% of these were covered by the health insurance. 2. Of the total restorations, 29.6% were cast cores, 18.2% were inlays and 17.2% were crowns. Post crowns, jacket crowns and partial veneer crowns were very few, being only 0.3%, 0.4% and 0.5%, respectively. 3. Approximately 50% of the prosthetic restorations were single crowns. 4. Compared to the record from about 20 years ago, the number as well as the ratio of the crowns including the facing crowns was approximately doubled. On the contrary, the number of jacket and post crowns has remarkably decreased. 5. With regard to the single anterior prosthetic restorations, the majority were the porcelain fused to metal crowns which were not popular 20 years ago.

Crowns↗
PubMed1991

[Caries-inducing activity of soybean-oligosaccharide (SOR) in vitro and in experimental dental caries of rats].

The caries-inducing activity of soybean-oligosaccharide (SOR: stachyose- and raffinose-rich sugar mixture) was examined in in vitro and in vivo experiments. Streptococcus mutans MT 8148R fermented SOR and produced acids. However Streptococcus sobrinus 6715 did not ferment. SOR was not able to act as a substrate for crude glucosyltransferases (GTase) of these mutans streptococci to synthesize the water-insoluble glucan. However, SOR did not inhibit the synthesis of water-insoluble glucan from sucrose by crude GTase. SOR was proved to be of low cariogenicity in rats infected with S. sobrinus 6715.

Animals↗
PubMed1990

17 beta-estradiol depolarization of hypothalamic neurons is mediated by cyclic AMP.

The process by which 17 beta-estradiol rapidly modulates the excitability of neurons in the ventromedial hypothalamus, a facilitation center of female sexual behavior and satiety center of feeding behavior, through mediation by cyclic nucleotides, was investigated by intracellular recording from the guinea pig brain slice preparations. Two types of short-term responses were produced by depolarization with decreased K+ conductance and hyperpolarization with increased K+ conductance. These two responses were enhanced by the phosphodiesterase inhibitor, isobutylmethylxanthine. However, the specific adenylate cyclase activator, forskolin, enhanced only the depolarization. The analogue of cyclic adenosine 3',5'-monophosphate (cAMP), 8-bromo-cAMP, induced only depolarization, the ionic mechanism of which was similar to that of 17 beta-estradiol. In addition, the possibility of non-specific effects of cyclic nucleotides was precluded by an experiment using an analogue of cyclic guanosine 3',5'-monophosphate (cGMP), 8-bromo-cGMP, which hyperpolarized neurons. Thus, the present study strongly suggests that the production of depolarizing responses of neurons in the hypothalamus produced by estradiol is specifically mediated through cAMP.

1-Methyl-3-isobutylxanthine↗
PubMed1990

Hypothalamic neuronal activity responses to 3-hydroxybutyric acid, an endogenous organic acid.

To elucidate the anorectic action of the endogenous organic acid, 3-hydroxybutyric acid (3-HBA), its effects on neurons in both the rat ventromedial hypothalamic nucleus (VMH) and the lateral hypothalamic area (LHA) were examined. Iontophoretic application of 3-HBA significantly facilitated the firing rate of VMH neurons, whereas facilitation and inhibition were observed in the LHA. These responses were specific to the glucoreceptor neurons in the VMH and glucose-sensitive neurons in the LHA. Intracellular recordings from brain slice preparations revealed that 3-HBA depolarized the cell membrane of the VMH neuron with an associated increase of membrane input resistance. This was similar to the effect of glucose on glucoreceptor neurons in the VMH. These results suggest that 3-HBA may modulate hypothalamic chemosensitive neuron activity as well as function as an endogenous satiety factor.

3-Hydroxybutyric Acid↗
PubMed1990

Cutaneous extramedullary hematopoiesis in myelofibrosis.

Erythematous papulonodules that resembled a malignant lymphoma developed in a 62-year-old man. Further examination revealed that he had primary myelofibrosis with cutaneous extramedullary hematopoiesis. All three marrow elements (myeloid, erythroid, and megakaryocytic series) were present in the skin lesions. Although extramedullary hematopoiesis of the skin is a rare complication of myelofibrosis, 13 similar cases have been reported. In nine cases, including ours, all three marrow elements were present in the cutaneous lesions.

Aged↗
PubMed1990

Somatosensory evoked potentials and adaptation to extrauterine life: a longitudinal study.

In order to compare longitudinal data with existing cross sectional extrauterine life data on somatosensory evoked potentials (SEPs), two groups of appropriate for gestational age optimal premature infants were studied. Group A consisted of 8 infants born between 34 and 36 weeks gestational age (GA). In this group, SEPs were recorded within 24 hours after delivery and then every 48-72 hours until discharge. Group B consisted of 7 infants born between 29 and 33 weeks GA. In these infants, SEPs were recorded at weekly intervals from the second week onwards. In group A, a marked decreased in the N1 latency was seen during the first week of life. Six infants had initial values above the normal range. During the second week of life this decrease paralleled the cross sectional data. In group B all the infants had a N1 latency within the normal range and the longitudinal data paralleled the cross sectional data. These findings must be taken into consideration when SEPs are used to assess the neurological integrity of the newborn during the first week of life.

Adaptation, Physiological↗
PubMed1990

Infant feeding and cardiorespiratory maturation.

134 preterm infants were investigated in their ability to coordinate sucking and breathing. Of those infants who did not coordinate, 79% showed immature cardiorespiratory control whereas of those who suck and breathe simultaneously only 12% had poor cardiorespiratory control. This finding suggests that in infants with poor coordination of sucking and breathing an investigation of cardiorespiratory control might be indicated.

Apnea↗
PubMed1990

The role of short latency somatosensory evoked responses in infants with rapidly progressive ventricular dilatation.

The effect of hydrocephalus on somatosensory evoked potentials was studied in nine infants. An increase in N1 latency was found in five infants studied longitudinally during a period of progressive ventricular dilatation. A marked decrease in N1 latency was noted in 7 infants, within one week following shunt insertion and in two infants who showed spontaneous arrest of ventricular growth. A correlation was found between cerebrospinal fluid pressure and the delay in N1 latency, but the number of infants studied is still small. SEPs appear to be a useful additional test when assessing infants with progressive ventricular dilatation. Once a baseline value for N1 has been obtained following shunt insertion, SEPs may subsequently be useful when assessing a child with possible shunt dysfunction.

Cerebral Hemorrhage↗
PubMed1990

Interaction of structural isomers of sucrose in the reaction between sucrose and glucosyltransferases from mutans streptococci.

Structural isomers of sucrose, i.e. disaccharides composed of glucose and fructose molecules with different glucosidic linkages, were examined for their effect on the reaction between sucrose and various glucosyltransferases (GTases) from Streptococcus mutans MT8148 and Streptococcus sobrinus 6715. Trehalulose (alpha 1-1), turanose (alpha 1-3), maltulose (alpha 1-4), and palatinose (alpha 1-6) were used as the sucrose analogues. Mutans streptococci were found not to utilize these sucrose analogues. Analysis of enzymatic products of GTase and sucrose with thin layer chromatography clearly revealed that glucan synthesis from [14C]sucrose by the various purified GTase preparations from S. mutans and S. sobrinus was inhibited in the presence of these sucrose analogues except turanose, resulting in the release of increased amounts of [14C]fructose and [14C]oligosaccharides. It was also found that the fructose residues in the oligosaccharides were derived from those of sucrose analogues but not sucrose itself. The Lineweaver-Burk plots of the substrate saturation kinetics of GTase vs sucrose indicated increased Km and Vmax in the presence of sucrose analogue, as compared with sucrose alone. Finally, these sucrose analogues except turanose inhibited sucrose dependent cellular adherence of S. sobrinus 6715 to a glass surface, while they scarcely inhibited the adherence of S. mutans MT8148. Among the analogues, maltulose appeared the most effective inhibitor against GTases in general.

Chromatography, Thin Layer↗