Biomedical subjects

T Imai

Publications and source records attributed to T Imai.

At least 163 records · Page 9Linked to original sources

PubMed2000

Possible involvement of endothelium-derived hyperpolarizing factor (EDHF) in the depressor responses to platelet activating factor (PAF) in rats.

1. In anaesthetized rats, platelet activating factor (PAF; 1 microg kg(-1)) decreased mean arterial blood pressure by around 60 mmHg (n=18). This depressor response was completely blocked by the PAF antagonist, CV-6209 (1 mg kg(-1)), indicating the role of PAF-specific receptor in the response. 2. N(G)-nitro-L-arginine methyl ester (L-NAME; 50 mg kg(-1)), an NO synthase inhibitor, profoundly elevated systemic blood pressure (n=19), indicating an important role of NO in the basal blood pressure regulation. The depressor response to PAF (1 microg kg(-1)) normalized against that to sodium nitroprusside (SNP) (10 microg kg(-1)) was not substantially different between rats treated without and with L-NAME (n=4). In contrast, the depressor effect of acetylcholine (0.03 - 1.0 microg kg(-1)) normalized against that of SNP (10 microg kg(-1)) was significantly attenuated by L-NAME (n=5). 3. Charybdotoxin (0.4 mg kg(-1)) plus apamin (0.2 mg kg(-1)) significantly attenuated the depressor response to PAF (1 microg kg(-1)) (n=5) without affecting the blood pressure change due to SNP (1 mg kg(-1)) (n=3). Charybdotoxin (0.4 mg kg(-1)) (n=4) or apamin (0.2 mg kg(-1)) (n=4) alone did not affect the PAF-induced depressor response. 4. These findings suggest that EDHF may make a significant contribution to the depressor response to PAF in rats. Although NO plays the determinant role in the basal blood pressure regulation, its contribution to PAF-produced depressor response seems to be less as compared with that to the depressor response to acetylcholine.

Animals↗

PubMed2000

Granzyme B-positive primary gastric T-cell lymphoma: gastric T-cell lymphoma with the possibility of extrathymic T cell origin.

A case of primary gastric T-cell lymphoma, which was positive for granzyme B, is reported. The patient was a 47-year-old Japanese female who complained of a dull upper abdominal pain. Radiographic and endoscopic examinations revealed an ulcerative infiltrative lesion in her stomach. Following the confirmation of a high-grade malignant lymphoma, a distal gastrectomy with regional lymph nodal dissection was performed. The histology of the gastric lesion revealed a malignant lymphoma of the diffuse pleomorphic type without lymph nodal involvement. Immunohistochemistry revealed that the tumor cells were positive for LCA, CD3, TIA-1 and granzyme B, but were negative for CD4, CD8, CD56, CD30, L-26, EMA, TCR alpha/beta and TCR gamma/delta. Because the tumor cells showed T cell nature with cytotoxic activity proved by TIA-1 and granzyme B, and without evidence of further maturation of T cell, a malignant lymphoma originating from extrathymic-derived T cells was suggested.

Biomarkers, Tumor↗

PubMed2000

Leukemia inhibitory factor induces epidermal hyperplasia in patients with amyotrophic lateral sclerosis.

We investigated the biochemical and morphologic alteration in skin of amyotrophic lateral sclerosis patients. We found an obvious high expression of leukemia inhibitory factor and distinct epidermal hyperplasia in the skin of amyotrophic lateral sclerosis patients compared with disease controls. The thickness and cell density, as well as the leukemia inhibitory factor immunostain density, of the epidermis in amyotrophic lateral sclerosis patients correlated positively with duration of illness. The striking fact was the significant epidermal hyperplasia correlating with leukemia inhibitory factor expression in amyotrophic lateral sclerosis patients (r = 0.94, p < 0.001). In vitro experiments revealed that leukemia inhibitory factor stimulated keratinocyte proliferation in primary keratinocyte culture and induced epidermal hyperplasia in skin organ culture. These findings lead to the hypothesis that a high expression of leukemia inhibitory factor is closely associated with epidermal hyperplasia in amyotrophic lateral sclerosis patients.

Adult↗

PubMed2000

Insulin resistance in patients with depression and its changes during the clinical course of depression: minimal model analysis.

A high proportion of patients with depression develop glucose intolerance accompanied by hyperinsulinemia, suggestive of reduced insulin sensitivity (insulin resistance). The aim of this study was to evaluate insulin sensitivity in patients with depression and its changes during the clinical course of depression. Twenty nondiabetic patients with depression (13 males and 7 females aged 44+/-14 years; body mass index [BMI] 23.2+/-2.8 kg/m2) were prospectively studied by the frequently sampled intravenous glucose tolerance test (FSIGT) and the oral glucose tolerance test (OGTT) before and after treatment of depression, and an age-, sex-, and BMI-matched control group (n = 13) was examined once by the FSIGT. Metabolic indices measuring glucose effectiveness at basal insulin (SG) and insulin sensitivity (SI) were derived from minimal model analysis. Each patient was treated by cyclic antidepressants with an 1,800 to 2,200 kcal/d food intake and underwent no exercise therapy. SI was significantly lower in patients before treatment versus control subjects (6.0+/-2.5 v 13.8+/-8.6 x 10(-5) min(-1) x mol(-1) x L, P < .01). After treatment of depression, a significant increase in SI (10.7+/-7.5 x 10(-5) min(-1) x mol(-1) x 1, P <t.01) was observed without changes in the BMI, fasting blood glucose, and SG. This was associated with a decrease in the insulin response during the OGTT and FSIGT. We conclude that patients with depression have impaired insulin sensitivity and resultant hyperinsulinemia and that these abnormalities can be resolved after recovery from depression.

Adult↗

PubMed2000

Increased serum hyaluronic acid in amyotrophic lateral sclerosis: relation to its skin content.

BACKGROUND: Abnormalities of hyaluronic acid (HA) of skin have been reported in patients with amyotrophic lateral sclerosis (ALS). However, little is known concerning the changes of serum HA in ALS. The purpose of this study was to investigate skin HA content and serum HA levels in ALS patients. METHODS: We measured skin HA content and serum HA levels in patients with ALS, and compared the results with those of control subjects. RESULTS: Skin HA content in ALS patients was significantly higher than in diseased control subjects and control subjects without neurological disorders, and increased significantly, the longer the duration of illness. Serum HA concentrations in patients with ALS were significantly higher than in diseased control subjects and in healthy control subjects, and were positively and significantly associated with duration of illness. There was an appreciable positive correlation between serum HA concentrations and skin HA content in ALS patients. CONCLUSION: These data suggest that a metabolic alteration of HA may take place in ALS and increased levels of serum HA may reflect an increased content of skin HA in ALS.

Adult↗

PubMed2000

A new PCR primer for the identification of Paracoccidioides brasiliensis based on rRNA sequences coding the internal transcribed spacers (ITS) and 5 x 8S regions.

Internal transcribed spacer (ITS) genes including the 5.8S ribosomal (r)RNA of Paracoccidioides brasiliensis were amplified and the DNA sequences were determined. Based on a comparison of the sequence information, a new polymerase chain reaction (PCR) primer pair was designed for specific amplification of DNA for P. brasiliensis. This primer pair amplified a 418-bp DNA sequence and was 100% successful in identifying 29 strains of P. brasiliensis (including the reference strains) isolated from the regions of Brazil, Costa Rica, Japan, Argentina or from different sources. The results of specificity tests of these primers to compare the fungus with those of Aspergillus fumigatus, Blastomyces dermatitidis, Candida albicans, Cryptococcus neoformans, Histoplasma capsulatum and Penicillium marneffei are also reported.

DNA Primers↗

PubMed2000

Physicochemical characterization of a new crystal form and improvements in the pharmaceutical properties of the poorly water-soluble antiosteoporosis drug 3,9-bis(N,N-dimethylcarbamoy-loxy)-5H-benzofuro[3,2-c]quinoline-6-one (KCA-098) by solid dispersion with hydroxypropylcellulose.

The present study was undertaken to improve the oral absorption of KCA-098, an antiosteoporosis drug. In this study, the form 2 of KCA-098 was used as a desirable crystal form for pharmaceutical formation among three kinds of crystal forms, 1, 2, and 3. Solid dispersions of KCA-098 with hydroxypropylcellulose (HPC) or poly(vinylpyrrolidone) (PVP) were prepared by the solvent method. The physicopharmaceutical properties of the solid dispersions were characterized by powder x-ray diffraction, FTIR spectroscopy, and differential scanning calorimetry (DSC). The powder x-ray diffractograms suggest that KCA-098 in the HPC-SL solid dispersion existed in a partial crystalline state as a new crystal form that could be produced by recrystallization from the solvent. Dissolution from the solid dispersions was markedly enhanced in comparison with that of the drug alone. The dissolution enhancement was observed to be greater for the solid dispersion with HPC-SL than for that with PVP. The KCA-098/HPC-SL (1:2) solid dispersion capsule showed a 3.5-fold increase in the initial concentration and 2.5-fold increase in initial concentration of dissolved drug after 60 min, compared with the values for a physical mixture of KCA-098 (form 2)/lactose (1:2). The in vivo absorption of the drug was investigated after oral administration of KCA-098 or its solid dispersion. The area under the plasma concentration curve of KCA-098 after oral administration of the KCA-098/HPC-SL (1:2) solid dispersion capsule was three-fold greater than that for the drug itself.

Absorption↗

PubMed2000

Long-term follow-up of clinical symptoms in TMD patients who underwent occlusal reconstruction by orthodontic treatment.

Fifty-eight patients (mean age 18.4 years) who had received splint therapy for internal derangement of the temporomandibular joint (TMJ) were examined retrospectively to investigate the efficacy of occlusal reconstruction by orthodontic treatment. The subjects were divided into three groups: 18 patients (mean age 18.6 years) who underwent orthodontic treatment combined with the use of splints (ST group); 27 patients (mean age 18.2 years) who underwent orthodontic treatment without the use of splints (NST group); and 13 patients (mean age 17.9 years) who received only splint therapy for temporomandibular joint disorders (TMD; control group). TMJ sound, pain on movement and restriction of mandibular movement were examined at the initial examination (T1), at the end of the splint therapy for TMD or beginning of orthodontic treatment (T2), at the end of orthodontic treatment (T3), and at recall or 1 year after orthodontic treatment (T4). The following results were found. (1) The percentage of patients with no joint sound at T2 was 20-30 per cent. The percentage of such patients in both the ST and NST groups increased to over 50 per cent at T3, but slightly decreased to 39-50 per cent at T4. There were no significant inter-group differences at any time point. (2) The number of patients who had no pain on movement at T2 was 60-80 per cent. The percentage of such patients in both the ST and NST groups increased to over 90 per cent at T3, but then slightly decreased to 80 per cent at T4. There were no significant inter-group differences at any time point. (3) None of the patients showed restriction of movement of the TMJ at T2 or T4. One patient in the ST group was found to have restriction at T3. There were no significant inter-group differences at any time point. (4) The most frequent type of malocclusion in both ST and NST groups was anterior open bite. These results suggest that TMD symptoms that have been eliminated by splint therapy are not likely to recur due to subsequent orthodontic treatment, but it cannot be concluded that orthodontic treatment itself had a positive effect on TMD symptoms. The results also indicate that there is a relationship between anterior open bite and TMD.

Adolescent↗

PubMed2000

Trapezoid bone fracture.

Fractures of the carpal bones involve only a single bone or complex bones with or without ligament rupture. However, fractures of the trapezoid are rarely seen. Because the trapezoid is fastened to the trapezium, capitate, and scaphoid by strong ligaments, fracture or dislocation is limited by this rigid fixation. The authors present a single bone fracture of the trapezoid in a 40-year-old man. A tomogram of the carpal bone was useful in diagnosing the trapezoid fracture. The mechanism for development of fracture of the trapezoid alone is unknown. However, fracture of the trapezoid seemed to occur when the wrist joint was forced with excessive flexion stress that was placed on the trapezoid through the second metacarpal bone indirectly. This occurred in the same manner that a walnut is broken with nutcrackers.

Adult↗

PubMed2000

Iron-deficiency anemia associated with Helicobacter pylori gastritis.

BACKGROUND: Recent studies have suggested an association of Helicobacter pylori and iron-deficiency anemia (IDA). This is a report of six cases of IDA associated with H. pylori gastritis. METHODS: Six patients with IDA were studied (5 boys and 1 girl; mean age 13.6 years; range 13-15 years). Five had a medical history of long-standing IDA and of oral iron supplementation at outpatient clinics. The anemia recurred after the iron therapy had been discontinued. The sixth patient was admitted to the hospital with severe IDA. An extensive work-up was ordered that included technetium-99m (99mTc) scans for Meckel's diverticulum, total colonoscopy, and gastrointestinal endoscopy. After biopsy-based H. pylori test results were confirmed to be positive, anti-H. pylori therapy consisting of lansoprazole, clarithromycin, and metronidazole was administered for 2 weeks with no iron supplementation. The hematologic profile and iron status were assessed periodically after the end of the eradication regimen. RESULTS: Upper gastrointestinal endoscopy revealed a marked antral nodularity but no evidence of bleeding lesions in all the patients. Given the histology and the fact that rapid urease test results were positive, chronic active gastritis with H. pylori was diagnosed in all these cases. H. pylori was successfully eradicated in all the patients. There was no evidence of IDA in any of the follow-up examinations between 27 and 50 months after anti-H. pylori therapy. CONCLUSIONS: H. pylori infection may be involved in cases of IDA of unknown origin, and the eradication of H. pylori can be associated with the resolution of anemia.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2000

Increased expression of insulin-like growth factor I in skin in amyotrophic lateral sclerosis.

OBJECTIVES: Insulin-like growth factor I (IGF-I) has potent effects on motor neuron survival and is being studied as a possible therapeutic agent for ALS. However, little is known concerning IGF-I in the skin of patients with amyotrophic lateral sclerosis (ALS). The aim was to evaluate IGF-I immunoreactivity of skin in patients with ALS. METHODS: IGF-I immunoreactivity of skin from 18 patients with ALS and 16 controls was examined. RESULTS: IGF-I immunoreactivity was markedly positive in the epidermis and dermal blood vessels and glands and was moderately positive in the reticular dermis in all patients with ALS. On the other hand, the epidermis and dermal blood vessels and glands and the reticular dermis showed a weak IGF-I immunoreactivity in controls. The optical density for IGF-I immunoreactivity of the epidermis and dermal blood vessels and glands, and the reticular dermis in patients with ALS was significantly higher than in diseased controls, and was significantly increased with duration of illness. CONCLUSIONS: These data suggest that a metabolic alteration of IGF-I may take place in the skin of patients with ALS.

Aged↗

PubMed2000

Increased expression of laminin 1 in the skin of amyotrophic lateral sclerosis.

Abnormalities of collagen and glycosaminoglycans of skin have been reported in patients with amyotrophic lateral sclerosis (ALS). However, little is known concerning laminin in ALS. The aim of this study is to evaluate laminin 1 immunohistochemistry of skin in ALS patients. We studied laminin 1 immunoreactivity of skin from 17 patients with ALS, 17 patients with other neurological or muscular diseases (control group A) and 10 patients without neurological or muscular disorders (control group B). The dermis, the epithelial basement membrane of the epidermal layer and the basement membrane of skin appendages and blood vessels of skin in ALS patients were significantly higher than in control groups A and B, and showed a significant positive correlation with the duration of illness in the optical density for laminin 1 immunoreactivity. In addition, there was an appreciable positive relationship in the laminin 1 immunoreactivity between the dermis and the basement membrane in ALS patients. These data suggest that alterations of laminin 1 in the skin of ALS patients could be related to the pathogenesis of ALS and may contribute to changes in the mechanical properties of the skin, resulting in the absence of bedsores in ALS patients.

Adult↗

PubMed2000

Serum markers of type I collagen synthesis and degradation in amyotrophic lateral sclerosis.

Collagen abnormalities in the skin and spinal cord have been reported in amyotrophic lateral sclerosis (ALS) patients. Serum carboxyterminal propeptide of type I procollagen (PICP) and the carboxyterminal cross-linked telopeptide of type I collagen (ICTP) reflect type I collagen synthesis and degradation, respectively. However, there has been no study concerning PICP or ICTP in ALS. We studied collagen contents of the skin and measured serum levels of PICP and ICTP in patients with ALS and control subjects. Serum PICP levels were significantly lower in ALS patients than in controls. Serum ICTP levels were significantly higher in ALS patients than in controls, and there was an appreciable positive correlation between serum ICTP levels and the duration of illness in ALS patients. In ALS patients, the collagen content of the skin was significantly smaller than in controls and indicated a progressive decrease in relation to illness. In addition, there was a significant negative correlation between serum ICTP concentrations and the collagen content of the skin in ALS patients. These data suggest that increased ICTP levels and decreased serum PICP levels may reflect unique changes in the skin, with a predominance of degradation compared to the synthesis of type I collagen in ALS.

Adult↗

PubMed2000

Musashi1: an evolutionally conserved marker for CNS progenitor cells including neural stem cells.

In situ detection of neural progenitor cells including stem-like cells is essential for studying the basic mechanisms of the generation of cellular diversity in the CNS, upon which therapeutic treatments for CNS injuries, degenerative diseases, and brain tumors may be based. We have generated rat monoclonal antibodies (Mab 14H1 and 14B8) that recognize an RNA-binding protein Musashi1, but not a Musashi1-related protein, Musashi2. The amino acid sequences at the epitope sites of these anti-Musashi1 Mabs are remarkably conserved among the human, mouse, and Xenopus proteins. Spatiotemporal patterns of Musashi1 immunoreactivity in the developing and/or adult CNS tissues of frogs, birds, rodents, and humans indicated that our anti-Musashi1 Mabs reacted with undifferentiated, proliferative cells in the CNS of all the vertebrates tested. Double or triple immunostaining of embryonic mouse brain cells in monolayer cultures demonstrated strong Musashi1 expression in Nestin(+)/RC2(+) cells. The relative number of Musashi1(+)/Nestin(+)/RC2(+) cells increased fivefold when embryonic forebrain cells were cultured to form 'neurospheres' in which stem-like cells are known to be enriched through their self-renewing mode of growth. Nestin(+)/RC2(-) cells, which included Talpha1-GFP(+) neuronal progenitor cells and GLAST(+) astroglial precursor cells, were also Musashi1(+), as were GFAP(+) astrocytes. Young neurons showed a trace of Musashi1 expression. Cells committed to the oligodendroglial lineage were Musashi(-). Musashi1 was localized to the perikarya of CNS stem-like cells and non-oligodendroglial progenitor cells without shifting to cell processes or endfeet, and is therefore advantageous for identifying each cell and counting cells in situ.

Amino Acid Sequence↗

PubMed2000

ADAMTS-1: a metalloproteinase-disintegrin essential for normal growth, fertility, and organ morphology and function.

A disintegrin and metalloproteinase (ADAM) represents a protein family possessing both metalloproteinase and disintegrin domains. ADAMTS-1, an ADAM family member cloned from cachexigenic colon adenocarcinoma, is unusual in that it contains thrombospondin type I motifs and anchors to the extracellular matrix. To elucidate the biological role of ADAMTS-1, we developed ADAMTS-1-null mice by gene targeting. Targeted disruption of the mouse ADAMTS-1 gene resulted in growth retardation with adipose tissue malformation. Impaired female fertilization accompanied by histological changes in the uterus and ovaries also resulted. Furthermore, ADAMTS-1(-/-) mice demonstrated enlarged renal calices with fibrotic changes from the ureteropelvic junction through the ureter, and abnormal adrenal medullary architecture without capillary formation. ADAMTS-1 thus appears necessary for normal growth, fertility, and organ morphology and function. Moreover, the resemblance of the renal phenotype to human ureteropelvic junction obstruction may provide a clue to the pathogenesis of this common congenital disease.

ADAM Proteins↗

PubMed2000

Effects of bilirubin and its photoisomers on direct bilirubin measurement using bilirubin oxidase.

We examined the reactivity of human serum albumin-bound bilirubin and its photoisomers as substrates for a direct bilirubin assay using bilirubin oxidase. The reduction of (EZ)-cyclobilirubin reached 100% 5 min after addition of the enzyme at any pH tested (3.5-7.4) in 0.1 mol/L phosphate buffer, whereas the reduction of (ZE)-bilirubin or (ZZ)-bilirubin reached 100% only below pH 4.5 or 5.5, respectively. (ZZ)-Bilirubin and its photoisomers did not react in citrate-lactate buffer at pH 3.7. The circular dichroism spectrum of (ZZ)-bilirubin in this buffer did not show a positive Cotton effect. These results indicate that a three-dimensional structure surrounding the reaction site of bilirubin is important for the reactivity with bilirubin oxidase.

Bilirubin↗

PubMed2000

Chemiluminescence because of the production of reactive oxygen species in the lungs of newborn piglets during resuscitation periods after asphyxiation load.

Reactive oxygen species are regarded as a possible cause of many diseases. However, there are few reports offering in vivo and in situ proof of the direct involvement of reactive oxygen species in the pathogenesis of disease. In the present study, the luciferin derivative 2-methyl-6-[4-methoxyphenyl]-3,7-dihydroimidazo [1,2-alpha] pyrazin-3-one (MCLA) was used to investigate the amount of reactive oxygen species produced during resuscitation after asphyxiation load in newborn piglets. The animals were first asphyxiated by stopping respiration for 4 min, and then resuscitated using 100% oxygen. When physiologic saline solution was administered, lung surface chemiluminescence had a mean value of 2, whereas with MCLA, a maximum luminescence of 580 was seen, demonstrating the possibility of measuring reactive oxygen species in vivo and in situ using MCLA. In a group in which resuscitation after acute asphyxiation was performed with 21% oxygen, the relative maximum lung surface chemiluminescence was 59.5+/-39, whereas that for a group in which resuscitation was performed using 100% oxygen had a significantly higher value of 186.1+/-72.5. Consequently, ventilation and especially resuscitation by 100% oxygen may represent a potential danger.

Animals↗

PubMed2000

Inclusion complex of 3,9-bis(N,N-dimethylcarbamoyloxy)-5H-benzofuro[3,2-c]quinoline-6-one (KCA-098) with heptakis(2,6-di-O-methyl)-beta-cyclodextrin: interaction and dissolution properties.

Interactions of KCA-098 with heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CyD) in solution and in the solid state were studied by the solubility method, UV and fluorescence spectroscopy, powder X-ray diffractometry, and thermal analysis. The KCA-098/DM-beta-CyD system showed an A(L) type solubility diagram with stability constants of 5870 and 2220 M(-1) in aqueous and 10% methanol solutions, respectively. Following the addition of DM-beta-CyD, the maximum UV wavelength of KCA-098 was shifted to a longer wavelength and the fluorescence intensity was decreased. A similar spectral change was observed when KCA-098 was dissolved in less polar solvents, especially in proton-acceptor solvents, such as acetone and dimethylsulfoxide, suggesting that KCA-098 interacts with DM-beta-CyD through not only a hydrophobic interaction but also hydrogen bonding. The solid complex of KCA-098 with DM-beta-CyD in a molar ratio of 1:1 was prepared by the kneading method and the solvent evaporation method, using organic solvents. Powder X-ray diffractometric and differential scanning calorimetric studies indicated that KCA-098 was dispersed as microparticles on the DM-beta-CyD complex in the solid state prepared by the solvent evaporation method although it dispersed as crystals in the sample prepared by the kneading method. The dissolution of KCA-098 from the solid complex prepared by the former method was markedly faster than that prepared by the latter method, although it slowed down with the passage of time. The reduced dissolution of KCA-098 was explained by crystallization to the hydrate form in the medium. These data indicate that poorly water-soluble KCA-098 interacts with DM-beta-CyD in water and in the solid state and that a fast-dissolving form of KCA-098 can be obtained by evaporating with DM-beta-CyD using organic solvents.

Calorimetry, Differential Scanning↗