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Biomedical subjects

M Yamaguchi

Publications and source records attributed to M Yamaguchi.

At least 55 records · Page 3Linked to original sources
PubMed2004

Fluorescence detection of a new photosensitizer, PAD-S31, in tumour tissues and its use as a photodynamic treatment for skin tumours in dogs and a cat: a preliminary report.

We describe here the detection by fluorescence of a new photosensitizer, PAD-S31, in tumours in dogs and cats and the effect of photodynamic therapy (PDT) by using PAD-S31 for skin tumours in two dogs and one cat. PAD-S31 is a hydrophilic photosensitizer that has two peaks at absorption wavelengths 406 and 665 nm in distilled water. In a preliminary experiment in mice transplanted with SCCVII and colon 26, PAD-S31 was retained in tumour tissues rather than in other organs. The tumours resected from dogs and cats after intravenous administration of PAD-S31 at a dose of 15 mg/kg emitted strong red fluorescence under light illumination of 402 nm wavelength. Animals given PAD-S31 showed no cutaneous photosensitivity under room light illumination. Irradiation at laser light 670 nm wavelength (fluence rate 150 mW/cm2 and total light dosage 150 J/cm2) on cutaneous mast cell tumours in dogs ( n=2 ) and a cutaneous basal cell tumour in a cat induced complete remission. These results suggest PAD-S31 could be a promising photosensitizer for use in a small animal veterinary practice.

Animals↗
PubMed2004

Smooth muscle hamartoma of the abomasum in a calf.

This report describes a case of smooth muscle hamartoma of the abomasum in a 6-month-old steer humanely killed because of severe pneumonia. At necropsy, marked thickening of the abomasal wall in the area of the pylorus was found. On cut section, the thickness of the submucosal layer, extending from the submucosa to the muscularis propria, was seen to be increased to 3 cm. The upper (i.e., nearest to the gut lumen) half of the sectioned thickening was composed mainly of adipose-like tissue and the lower half mainly of muscle-like tissue. Histologically, the submucosal layer was composed of fibroadipose tissue, within which were embedded, to varying degrees, numerous well-defined, haphazardly oriented, thin to thick bundles of smooth muscle fibres. This appears to be the first report of smooth muscle hamartoma of the stomach or abomasum in animals, including man.

Abomasum↗
PubMed2004

Inactivation of Escherichia coli by ultrasonic irradiation.

Ultrasonic inactivation of Escherichia coli XL1-Blue has been investigated by high-intensity ultrasonic waves from horn type sonicator (27.5 kHz) utilizing the "squeeze-film effect". The amplitude of the vibration face contacting the sample solution was used as an indication of the ultrasonic power intensity. The inactivation of the E. coli cells by ultrasonic irradiation shows pseudo first-order behavior. The inactivation rate constant gradually increased with increasing amplitude of the vibration face and showed rapid increase above 3 microm (p-p). In contrast, the H2O2 formation was not observed below 3 microm (p-p), indicating that the ultrasonic shock wave might be more important than indirect effect of OH radicals formed by ultrasonic cavitation in this system. The optimal thickness of the squeeze film was determined as 2 mm for the E. coli inactivation. More than 99% of E. coli cells was inactivated within 180-s sonication at the amplitude of 3 microm (p-p) and 2 mm of the thickness of the squeeze film.

Escherichia coli↗
PubMed2004

Differential modulation of human basophil functions through prostaglandin D2 receptors DP and chemoattractant receptor-homologous molecule expressed on Th2 cells/DP2.

BACKGROUND: Both prostaglandin (PG) D receptor (DP) and CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells)/DP2 are high-affinity receptors for PGD2. Previous studies have demonstrated that PGD2 enhances releasability and induces CRTH2/DP2-mediated migration in human basophils, but the precise effects of PGD2 on basophils as well as receptor usage have not been fully clarified. OBJECTIVE: We comprehensively explored the roles of DP and CRTH2/DP2 in basophil functions by using selective agonists and antagonists for each receptor. METHODS: DP and CRTH2/DP2 transcripts were quantified by real-time PCR. We studied the effects of selective agonists (DP: BW245C; CRTH2/DP2: 13,14-dihydro-15-keto (DK)-PGD2) and/or antagonists (DP: BWA868C; CRTH2/DP2: ramatroban) on Ca2+ mobilization, migration, degranulation, CD11b expression and survival of human basophils. RESULTS: Basophils expressed transcripts of both DP and CRTH2/DP2, but the levels of CRTH2/DP2 transcripts were ca. 100-fold higher compared with DP transcripts. Ca2+ influx was induced in basophils by either PGD2 or DK-PGD2/CRTH2 agonist but not by BW245C/DP agonist. Basophils treated with PGD2 were completely desensitized to subsequent stimulation with DK-PGD2, but not vice versa. DK-PGD2 as well as PGD2 up-regulated CD11b expression, induced migration and enhanced degranulation, and those effects were completely antagonized by ramatroban/CRTH2 antagonist. In contrast, BW245C/DP agonist exhibited an inhibitory effect on basophil migration and IgE-mediated degranulation, and the migration inhibitory effect was effectively antagonized by BWA868C/DP antagonist. On the other hand, while PGD2 significantly shortened the basophil life-span, neither DK-PGD2/CRTH2 agonist nor BW245C/DP agonist did. CONCLUSION: CRTH2/DP2 is primarily responsible for the pro-inflammatory effects of PGD2 on human basophils, while DP introduces negative signals capable of antagonizing the effects of CRTH2/DP2 in these cells. The effects of PGD2 on longevity imply a mechanism(s) other than via DP or CRTH2/DP2. CRTH2/DP2 on basophils may afford opportunities for therapeutic targeting in allergic inflammation.

Basophils↗
PubMed2004

Repetitive cocaine administration decreases neurogenesis in adult rat hippocampus.

Cocaine HCl (20 mg/kg) was administered to adult male rats to investigate the effects of cocaine on neurogenesis in the hippocampus. Proliferation of granule cells in the dentate gyrus was measured by in vivo labeling with 5-bromo-2'-deoxyuridine (BrdU). Rats that received repetitive cocaine treatment for 14 days showed 26% fewer BrdU-positive cells relative to control rats, while no difference was observed in the rats that received a single injection of cocaine. Differentiation of newly born cells was not influenced. The present experiment is the first to demonstrate the influence of cocaine on hippocampal neurogenesis. These data suggest that the regulation of hippocampal neurogenesis may be involved in the emergence of certain symptoms of cocaine addiction, such as cognitive impairment and behavioral sensitization.

Animals↗
PubMed2004

Cryogenic trapping for determination of odor concentration.

The sensory testing method applied under Japanese law to measure odor concentration has a lower detection limit of 10 in the specified Odor Index. To measure odor below the limit, a condensing procedure using solid sorbents (Tenax-TA, Unicarbon B and Carbosieve SIII) has been developed and used in Japan. This procedure however cannot condense all odorous substances, and is specifically unsuited to hydrogen sulfide, methyl mercaptan, dimethyl sulfide, ammonia, and other typical odorous substances. In the present study, cryogenic trapping was tested to improve recovery rate. As water in sample air causes choking of the trap tube, vacant pre-columns to condense the water were connected to the Tenax-TA-packed column. The columns were chilled with liquid oxygen before passage of 100 L of sample air. The columns were then heated to 200 degrees C under passage of 50 mL/min of nitrogen carrier gas to desorb odors. The desorbed gases were captured in sampling bags made of polyethylene terephthalate film. The total volume of desorbed gases was approximately 1 L. The method showed good recovery rates for hydrogen sulfide, methyl mercaptan, dimethyl sulfide and ammonia, and was useful for determining low-level odor concentrations during measurement of odor in ambient air at various sites in Osaka City.

Absorption↗
PubMed2003

Pulmonary agenesis with congenital heart disease.

The combined anomalies of pulmonary agenesis and congenital heart disease are exceedingly rare and a highly lethal association. We describe four cardiovascular operations in three patients with this association. Open-heart surgery was performed in two patients, and palliative heart surgery was performed in two patients. One patient died 100 days after the operation because of severe tracheal stenosis and renal failure, but the other two patients are doing well. Surgical access through a thoracotomy, instead of a median approach, was adequate in all patients. Careful evaluation and a precise understanding of the anatomy are necessary for the surgical management of these patients.

Abnormalities, Multiple↗
PubMed2003

Tandem duplication of alkaline phosphatase genes and polymorphism in the intergenic sequence in Bombyx mori.

Alkaline phosphatases are ubiquitous in organisms from bacteria to human. Two alkaline phosphatase genes, Alp-m and Alp-s, were independently cloned from the silkworm Bombyx mori. They were mapped to a small DNA region and shown to be organized in tandem. Exon-intron structures of the two genes were highly conserved, with the exception of the second intron in Alp-m, which has no counterpart in Alp-s. The similarity between the nucleotide sequences of the exons of the two genes was strikingly high (60-79%), suggesting that Alp-m and Alp-s originated from a duplication of their common ancestor gene. The intergenic sequence between the two Alp genes shows length polymorphism in different B. mori strains, which can be explained by presence/absence of two putative insertion sequences. This structural variation suggests a possible scenario for the divergence of the two Alp genes after the duplication event.

Alkaline Phosphatase↗
PubMed2003

Elastic stiffness of the nuclear-spin system in tetragonal U2D2 nuclear-ordered solid (3)He.

We have measured temperature dependences of sound velocity for both longitudinal and transverse sound in nuclear-ordered U2D2 solid 3He with several crystal orientations along the melting curve. The sound velocity change was proportional to T4 for all sound modes and crystal orientations and was attributed to the nuclear-spin part of the internal energy. We extracted six-independent elastic stiffness of the nuclear-spin part and obtained Grüneisen constants of the spin wave velocity for four-independent strains. Grüneisen constants for compressional strain were larger than those for shear strain. Using the multiple-spin-exchange model, we explain the anisotropy of Grüneisen constants in tetragonal symmetry.

Journal Article↗
PubMed2003

Congenital heart disease with hypereosinophilic syndrome.

The idiopathic hypereosinophilic syndrome, common in adults, is a leukoproliferative disorder marked by a predilection to damage specific organs. This report describes a unique case of an infant with tricuspid stenosis, a hypoplastic right ventricle, severe pulmonary stenosis, patent ductus arteriosus, and a patent foramen ovale associated with hypereosinophilic syndrome. Although treatment with high-dose oral steroids failed to decrease the leukocyte counts, a right classic Blalock-Taussig shunt through a right thoracotomy resolved her cyanosis.

Female↗
PubMed2003

Effect of rolipram on muscarinic acetylcholine receptor binding in the intact mouse brain.

The effect of rolipram, a selective inhibitor of phosphodiesterase type 4 (PDE(4)) and elevating cyclic AMP (cAMP), on in vivo and in vitro (3)H-N-methylpiperidyl benzilate ((3)H-NMPB) binding to muscarinic acetylcholine receptors in the mouse brain was examined. Rolipram significantly decreased in vivo (3)H-NMPB binding in the cerebral cortex, hippocampus and striatum, whereas in vitro (3)H-NMPB binding in these regions was not altered. Saturation experiments on in vivo binding in conjunction with the kinetic analysis revealed that the apparent association rate constant (k(on)) of (3)H-NMPB binding in vivo was significantly decreased by rolipram. A similar decrease in the apparent association rate constant (k(on)) by rolipram was reported for dopamine D(1) and D(2) receptor binding in vivo. These results indicate that rolipram plays an important role in the global modulation of apparent rates of ligand-receptor interactions in the intact brain.

Animals↗
PubMed2003

Activation of 5-HT(1A) autoreceptors enhances the inhibitory effect of galanin on hippocampal 5-HT release in vivo.

The microdialysis technique was used to examine interactions between 5-HT(1A) and galanin receptors in the dorsal raphe nucleus (DRN), by measuring the extracellular levels of 5-HT in the ventral hippocampus of awake rats. The rats were pretreated with the 5-HT(1A) receptor agonist (R,S)-8-OH-DPAT (0.3 mg/kg, s.c.) or saline. 8-OH-DPAT caused a time-dependent reduction of basal 5-HT levels down to 43-48% at 40 min while at 140 min, the hippocampal 5-HT had returned to control values. At that time point, the rats received a second injection of 8-OH-DPAT or galanin (0.15, 0.5 and 1.5 nmol/0.5 microl) infused into the lateral ventricle. The second injection of 8-OH-DPAT caused a significantly smaller reduction of hippocampal 5-HT levels. In contrast, galanin at all three doses in the 8-OH-DPAT-pretreated groups, was significantly more potent in reducing 5-HT levels (maximal reduction to 74%, 52% and 49%, respectively) than it was in saline-pretreated rats (maximal reduction to 96%, 85% and 69%, respectively). The inhibitory effect of galanin (1.5 nmol) on extracellular 5-HT levels in the rat hippocampus was significantly attenuated by co-administration of the 5-HT(1A) receptor antagonists WAY-100635 (0.3 and 0.6 mg/kg s.c.) and, to a lesser extent, with pindolol (20 mg/kg s.c.). These data provide direct in vivo evidence of agonistic 5-HT(1A)-galanin receptor interaction at the presynaptic level. Furthermore, the findings indicate that a down-regulation of the somato-dendritic 5-HT(1A) autoreceptors, following their stimulation with 8-OH-DPAT and possibly also indirectly with 5-HT reuptake inhibitors, may be compensated by a subsequent 'sensitization' of the inhibitory galanin receptors in the DRN. Thus, the enhanced galanin receptor-mediated inhibition of 5-HT neurotransmission may contribute to the pathophysiology of depression or to the reduced and delayed efficacy of antidepressant therapies.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2003

Hypoplasia of primary and permanent teeth following osteitis and the implications of delayed diagnosis of a neonatal maxillary primary molar.

A 2-year-and-6-month-old Japanese girl with delayed eruption of a maxillary right primary canine and disturbance in the development of maxillary right primary molars was examined. The crown of the maxillary right first primary molar was severely decayed and hypoplastic. The periodontal tissues on the maxillary right posterior region were swollen and slight erythrogenic change was observed. Radiographic examination revealed a disturbance in the development of the permanent successor and the primary teeth in the maxillary right quadrant. According to the history, the maxillary right first primary molar had erupted on day seven after birth. It is suggested that the disturbance in development of the permanent successor and the primary teeth was secondary to osteitis caused by infection of the neonatal tooth. Appropriate dental treatment had not been administered for more than two years because the neonatal molar had not been diagnosed.

Child, Preschool↗
PubMed2003

The association between end-stage diabetic nephropathy and methylenetetrahydrofolate reductase genotype with macroangiopathy in type 2 diabetes mellitus.

The T/T genotype of the methylenetetrahydrofolate reductase C677 T gene polymorphism is associated with elevated homocysteine levels and presumably with increased atherosclerotic risk. We evaluated the interaction between this gene polymorphism and end-stage diabetic nephropathy on the observed prevalence of macroangiopathy in type 2 diabetes mellitus. The methylenetetrahydrofolate reductase 677 C/T genotypes were determined in 174 type 2 diabetic patients: 80 with and 94 without renal failure due to diabetic nephropathy. In the patients with renal failure, the T/T genotype and T allele were significantly associated with macroangiopathy (T/T; 31 % vs. 2 %, P = 0.0001 T allele; 59 % vs. 29 %, P = 0.00014), whereas the associations were not significant in the patients without renal failure. In the multiple logistic regression analysis, age (10 years OR 4.05 [1.79 - 9.31], P < 0.0005) and 677 T allele (6.84 [2.12 - 22.05], P = 0.0013) were significantly associated with macroangiopathy in the patients with renal failure. In conclusion, this study demonstrated that the 677 T/T genotype and T allele of MTHFR were significantly associated with macroangiopathy in type 2 diabetic patients with renal failure. The MTHFR 677 T allele, together with renal dysfunction due to diabetic nephropathy, could be a strong risk factor for atherosclerotic disease.

Aged↗
PubMed2003

QT dispersion and left ventricular morphology in patients with hypertrophic cardiomyopathy.

OBJECTIVE: To evaluate the relation between QT variables and disproportion of left ventricular wall hypertrophy in patients with hypertrophic cardiomyopathy. DESIGN: Retrospective analysis of the results of echocardiography and electrocardiography. SETTING: University hospital (tertiary referral centre). PATIENTS: 70 patients with hypertrophic cardiomyopathy were divided into four groups according to the distribution of left ventricular wall hypertrophy on cross sectional echocardiography: group A--hypertrophy confined to the interventricular septum; group B--hypertrophy confined to the interventricular septum and left ventricular anterior wall; group C--hypertrophy confined to the interventricular septum, left ventricular anterior wall, and lateral free wall; group D--hypertrophy involving all portions of the left ventricle. MAIN OUTCOME MEASURES: QT intervals and QT dispersion in precordial six lead ECGs. RESULTS: There were no significant differences in the maximum left ventricular wall thickness among the four groups, and maximum and minimum QTc intervals also did not differ. QTc dispersion was increased significantly in groups A and B compared with groups C and D. Dispersions of the interval from the J point to the end of the T wave (JTc dispersions) in groups A and B were also increased significantly compared with groups C and D. By linear regression analysis, QTc and JTc dispersions correlated with the ratio of the interventricular septal thickness to left ventricular posterior wall thickness (p = 0.0152 and p = 0.0075, respectively). CONCLUSIONS: QT dispersion may be affected by not only electrical inhomogeneity but also by morphological inhomogeneity of the left ventricle in patients with hypertrophic cardiomyopathy.

Adult↗
PubMed2003

[Long-term results after the total cavopulmonary connection].

Between July, 1988 and November, 2002, 108 patients underwent total cavopulmonary connection (TCPC) at Kobe Children's Hospital. The primary malformation was univentricular heart in 40 tricuspid atresia in 21, mitral atresia in 16, and other complex cardiac defects in the remaining 31. Fenestrated TCPC, staged TCPC, and off-pump TCPC were performed in 39, 26, and 15 high risk patients, respectively. Nitric oxide inhalation was administered in 46 patients. The mean follow-up period was 4.3 years (range, 1 month to 14 years). There were 10 early deaths due to low cardiac output syndrome in 4, thrombosis in 3, tracheal bleeding in 2, and disseminated intravascular coagulation in 1. There were 5 late deaths due to congestive heart failure in 2 patients, arrhythmia in 1, cerebral infarction in 1, and subarachnoid hemorrhage in 1. Late complications included arrhythmia in 17 patients, systemic desaturation caused by abnormal systemic venous channels in 10, pleural or pericardial effusion in 3, chylothorax in 1, and aortic valve incompetence in 1.

Adolescent↗
PubMed2003

[A successful thrombolytic therapy for thrombosed ATS valve in the mitral position in a child; report of a case].

We report a successful thrombolytic therapy for thrombosed ATS valve in the mitral position in a child. A 5-year-old girl was underwent mitral valve re-replacement with ATS mechanical valve for prosthetic valve stenosis in the mitral position. The postoperative course was uneventful, but an unilateral thrombosed leaflet of a ATS valve was observed 26 days after the operation by fluoroscopy. Thrombolytic therapy with urokinase was done and the thrombus was successfully dissolved.

Child, Preschool↗