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Biomedical subjects

S Takeuchi

Publications and source records attributed to S Takeuchi.

At least 145 records · Page 8Linked to original sources
PubMed2000

Phytotoxicity of indole-3-acetic acid produced by the fungus, Pythium aphanidermatum.

Pythium aphanidermatum causes the serious disease of Pythium red blight on bentgrass. IAA, one of the metabolites that has been isolated from this fungus, showed the same symptom of Pythium red blight on bentgrass at a concentration of 1,000 mg/1. The IAA content in the foliage of bentgrass infected by this fungus was about 200 times that of an untreated control. These results suggest that IAA produced by this fungus was the causal substance of Pythium red blight on bentgrass.

Indoleacetic Acids↗
PubMed2000

Inhibitory effect of apple pectin and culture condensate of Bifidobacterium longum on colorectal tumors induced by 1,2-dimethylhydrazine in transgenic mice harboring human prototype c-Ha-ras genes.

The number and tumor score of colorectal tumors induced by 1,2-dymethylhydrazine in transgenic (Tg) mice carrying human c-Ha-ras genes were significantly reduced by ingestion of apple pectin (AP) or a culture condensate of Bifidobacterium longum (MB) when compared with a control diet. There was no statistical difference in the incidence of colorectal tumors in Tg mice between the AP or MB diet and the control diet. This study demonstrated that Tg mice are a useful tool for screening inhibition of colorectal tumors by functional foods.

1,2-Dimethylhydrazine↗
PubMed2000

Transforming growth factor-alpha stimulates proliferation of mammotrophs and corticotrophs in the mouse pituitary.

Oestrogen stimulates the proliferation of pituitary cells. The present study was designed to clarify the involvement of transforming growth factor-alpha (TGF-alpha) in the oestrogen-induced growth of mouse pituitary cells in vitro. Anterior pituitary cells obtained from ICR male mice were cultured in a primary serum-free culture system. Proliferation of pituitary cells was detected by monitoring the cellular uptake of bromodeoxyuridine. Secretory cell types were immunocytochemically determined. Treatment with TGF-alpha (0.1 and 1 ng/ml) for 5 days stimulated cell proliferation. Since TGF-alpha binds to the epidermal growth factor (EGF) receptor, this action may be exerted through the EGF receptor. Oestradiol-17beta (OE(2), 10(-)(9) M) stimulated mammotrophic and corticotrophic cell proliferation. RG-13022, an EGF receptor inhibitor, inhibited the cell proliferation induced by EGF or OE(2), showing that the EGF receptor was involved in the growth response in mammotrophs and corticotrophs. Treatment with antisense TGF-alpha oligodeoxynucleotide (ODN) inhibited the cell proliferation induced by OE(2), but treatment with antisense EGF ODN did not. RT-PCR analysis revealed that OE(2) stimulated TGF-alpha mRNA and EGF receptor mRNA expression. These results indicate that TGF-alpha mediates the stimulatory effect of oestrogen on the pituitary cell proliferation in a paracrine or autocrine manner, and that EGF receptor expression is stimulated by oestrogen.

Animals↗
PubMed2000

Silicone oil and fluorosilicone.

Silicone oil has been used to fill the vitreous cavity for long-term or permanent internal tamponade in eyes with proliferative vitreoretinopathy or complicated retinal detachment due to ocular trauma, giant retinal tears, proliferative diabetic retinopathy, and cytomegalovirus retinitis. Reports from the Silicone Study confirmed its efficacy in the treatment of proliferative vitreoretinopathy and addressed outcome differences in vitrectomized and nonvitrectomized eyes, combined retinotomy, silicone oil removal, and complications associated with silicone oil tamponade, such as intraocular pressure abnormalities and corneal abnormalities. Because silicone oil is lighter than water and not adequate in supporting the inferior quadrants, several heavier-than-water materials have been introduced for intraocular tamponade. Silicone oil can be a potential vehicle for delivering antiproliferative agents to treat proliferative vitreoretinopathy.

Humans↗
PubMed2000

Genetic characterization of adenovirus strains isolated from patients with acute conjunctivitis in the city of São Paulo, Brazil.

Genome analysis was carried out on adenovirus strains isolated from patients with acute follicular conjunctivitis in the city of São Paulo, Brazil. Eighteen conjunctival scrapings, collected between December 1993 and March 1994, were analyzed by two methods: a combination of polymerase chain reaction with restriction fragment length polymorphism and viral DNA restriction analysis, carried out using 10 restriction endonucleases: BamHI, BglI, BglII, HindIII, KpnI, SacI, SalI, SmaI, XbaI, and XhoI. Among 11 adenovirus detected by cell culture isolation, nine were Ad8, and two were Ad7. By restriction analysis the Ad8 isolates were typed as two new variants-Ad8/D11 (seven of nine samples) and Ad8/D12 (two of nine samples). Ad7 isolates were identified as a subtype of the widespread genome type Ad7b and the virulent type Ad7h, a predominant genome type circulating in Argentina, Chile, and Uruguay but absent in Brazil until 1991.

Acute Disease↗
PubMed2000

[Vitrectomy for the treatment of expulsive hemorrhage].

PURPOSE: To evaluate the surgical outcome of vitrectomy in the treatment of expulsive hemorrhage associated with intraocular surgery. METHODS: We reviewed 12 eyes from 12 patients with expulsive hemorrhage, occurring after or during cataract extraction (4 eyes), phacoemulsification (2 eyes), glaucoma filtering surgery (4 eyes), or vitrectomy (2 eyes). Mean follow-up period was 21 months. RESULTS: The retina was reattached in 6 eyes (50%) after the initial surgery and ultimately in 9 eyes (75%). Three eyes, which failed to achieve retinal reattachment, resulted in phthisis bulbi. Final visual acuity was 0.1 or belter in 4 eyes and 0.01 to 0.09 in 4 eyes. The incidence of expulsive hemorrhage was 0% for cataract surgery, 0.57% for trabeculectomy, and 0.09% for vitrectomy at Toho University Sakura Hospital. CONCLUSION: In the treatment of expulsive hemorrhage, vitrectomy is an effective surgical procedure to improve the visual function.

Adolescent↗
PubMed2000

[Morphological transformation of limb bones with growth].

The development of the long limb bones consists of two developmental types, one for the length and the other for the thickness. Although the development of the length is due to the growth of the epiphyseal cartilage, the development of width is due to the addition of bone to the periosteal membranes. Growth of bones is influenced not only by chemical factor, such as hormone or vitamin, but also by physical factor such as electrical or mechanical stresses. Changes in the development of the limb bones caused by mechanical stress were studied. The limb bones, which belonged to a hydrocephalic patient who had been bedridden for 16 years, were measured. The lower limb bones had almost no mechanical stress such as weight or walking, due to his being bedridden for many years. He also could not exercise his upper extremity, hence mechanical stress to the upper limb bones was minimal. The circumference at the mid-shaft of each long bone was shorter than the average circumference of the same age. The thickness was also narrower, suggesting Wolff's law. However, no difference was found in length between the subject and the average. While mechanical stress was a factor that accelerated the thickness of the limb bones, stress did not have much influences on the length of the long limb bones. The length of the right clavicle was longer than that of the left due to the pressure of maintaining the same posture. In an experimental study of tail suspended rats showed that there was no significant difference in the length of hindlimb between the experimental group and control group, though a difference was found in the length of forelimb. The length of forelimb in the experimental group was significantly shorter than the control group due to weight pressure. This result suggests that physical pressure in the longitudinal direction is one of the factors that inhibits the growth of the length of bones and that mechanical stress is important for the morphology and the function of bones. Stress exerts different influence to accelerate or inhibit bones according to the direction.

Aging↗
PubMed2000

Outcome of patients with cyanotic congenital heart disease undergoing a second systemic-to-pulmonary artery shunt.

BACKGROUND: Multiple systemic-to-pulmonary artery shunts often represent a deviation from the initial management strategy for cyanotic congenital heart disease. This study analysed the outcome in patients undergoing a second shunt. METHODS: Between 1965 and 1998, 80 patients required a second shunt. Patient age ranged from 11 days to 11.2 years at the initial shunt, and 4 months to 25.6 years at the second shunt. The interval between shunts ranged from 11 days to 19.6 years. RESULTS: The patient survival rates at 1, 6, 12, 60 and 120 months following the second shunt were 95.0 +/- 2.4%, 92.5+/-3.0%, 87.4+/-3.7%. 82.4+/-4.5% and 74.8+/-5.8%, respectively. Although excess pulmonary flow was not encountered after the second shunt, mode and incidence of morbidity were otherwise similar to the first one. Between 9 months and 7.5 years after the second shunt, 24 patients underwent successful definitive repair. Multivariable analysis identified pulmonary atresia (p=0.027) and a short (<1 year) interval between the two shunts (p=0.034) as the independent risk factors for long-term shunt failure. Single ventricle physiology (p=0.002) and a central approach for the second shunt (p=0.016) were independent risk factors for lack of application, or failure of intracardiac definitive repair. CONCLUSIONS: A significant limitation in longevity and quality of life is common in patients requiring a second shunt, especially those associated with pulmonary atresia, the single ventricle physiology heart, or ungraftably hypoplastic contralateral branch pulmonary artery to the first shunt. Since excess pulmonary blood flow leading to congenital heart failure and/or ventricular diastolic dysfunction is unlikely, all patients who preclude definitive repair due to decreased pulmonary blood flow even after the first shunt should be shunted again.

Blood Vessel Prosthesis Implantation↗
PubMed2000

Aortic valve replacement with concomitant annular enlargement for small aortic annulus of less than 19 mm.

Three female patients with aortic stenosis associated with a severely small annulus underwent aortic valve replacement. In intraoperative measurements, a 19-mm obtulator could not pass through the aortic annulus in each case. We therefore concluded that it would be difficult to implant an appropriate-sized prosthesis in a routine fashion, so we performed an annular enlargement in a modified Nicks procedure. By using a wide teardrop-shaped patch for enlargement and slightly tilting insertion of a prosthesis, a 21 mm bileaflet mechanical prosthesis could be inserted into the enlarged annulus. Despite being a simpler method than other enlarging procedures, a two- or three-sizes larger prosthesis than the native annulus can be inserted with relative ease. Thus, the use of a 19 mm mechanical prosthesis may be avoidable in most adult cases.

Aged↗
PubMed2000

[Juvenile ischemic type of moyamoya disease: a case report].

Moyamoya disease is a rare, chronic cerebrovascular disorder characterized by progressive stenosis of the arteries composing the circle of Willis. The ischemic type of Moyamoya disease progresses insidiously. To prevent irreversible cerebral damage and psychomotor deterioration, early surgical treatment is considered indispensable. The patient may present with nonspecific symptoms and no specific abnormalities on brain MRI, and might be erroneously suspected as having psychosomatic disorder. The disease must be diagnosed as early as possible. Electroencephalography (EEG) is of little value in the diagnosis of the juvenile type of Moyamoya disease, except for the demonstration of "re-build up" after hyperventilation. Half of the children with Moyamoya disease have been demonstrated to exhibit "re-build up" after hyperventilation. Our patient showed normal background activities, no spike discharges and no slowing during hyperventilation. Nonetheless, we emphasize the appearance of irregular high voltage slow waves de novo after hyperventilation. The findings may be potentially useful for the screening of patients with the juvenile type of Moyamoya disease.

Adolescent↗
PubMed2000

[Xeroderma pigmentosum].

Xeroderma pigmentosum(XP) is an autosomal recessive disease that is characterized by hypersensitivity to sunlight with high incidence of skin cancer and that exhibit variable neurological abnormalities in some groups. There are eight different complementation groups in XP; groups A through G and a variant(XP-V). XP-A through XP-G have a defect in nucleotide excision repair(NER), while XP-V has a defect in translesion DNA synthesis. Almost all of genes for XP have been cloned and their functions in the NER mechanism have been progressively unveiled. In this review, the present knowledge of the pathological features and genetic defects in XP has been discussed.

Animals↗
PubMed2000

Placement of interatrial patch suture lines in atrioventricular canal defect repair.

BACKGROUND: The placement of the suture line for interatrial patches in complete and incomplete atrioventricular canal defect repairs varies from surgeon to surgeon despite established anatomic knowledge of the atrioventricular conduction system. This study describes our technique for it and reviews early and long-term outcomes. METHODS: Between 1980 and 1999, 64 infants and children underwent repair of either complete (n=39) or incomplete (n=25) atrioventricular canal defects. Thirty-four of the children (53.1%) had Down's syndrome. The suture line for the interatrial patch originated on either the artificial or native ventricular septal crest and continued leftward above the annulus of the left inferior leaflet of the atrioventricular valve at the posteroinferior corner. All stitches were placed in a horizontal mattress or U-shaped fashion. RESULTS: The operative survival rate was 94% (4 early deaths) and the overall survival rate was 85% (6 late deaths). Atrioventricular heart blocks occurred in none of the patients. Although left-sided atrioventricular function significantly improved with repair, two patients (3.1%) required reoperation for valve replacement because of residual or recurrent insufficiency. CONCLUSIONS: This suture technique for interatrial patches is straightforward and results in a low incidence of heart block and a low re-operation rate for left atrioventricular valve insufficiency.

Cardiac Surgical Procedures↗
PubMed2000

[Combined use of ante- and retrograde cardioplegia: limited efficacy in elective coronary artery bypass].

One Hundred and twenty-four patients undergoing elective coronary bypass surgery were retrospectively selected and divided into two groups according to their difference of cardioplegic methods, either antegrade (AC) only (n = 65) or combination of ante- and retrograde (AC + RC) cardioplegic delivery (n = 64). Myocardial blood flow in the right (RV) and left ventricles (LV) was measured during the cardioplegia by a laser Doppler. Peak CPK-MB levels were compared postoperatively between the two groups and more in detail according to extent of coronary obstructive disease. 1) The antegrade administration of cardioplegic solution provided preferential flow to the RV compared to the LV, whereas the retrograde administration resulted in the opposite result (AC; LV 6.9 +/- 4.7, RV: 8.6 +/- 5.3, p < 0.05, RC; LV: 9.0 +/- 4.9, RV: 5.9 +/- 4.6 ml/min/100 g, p < 0.05). This result suggested that the combination of both administrations was meaningful to obtain uniform distribution of cardioplegic solution. 2) The peak CPK-MB, compared in the entire two groups, was slightly low in the combination use (AC; 48 +/- 16, AC + RC; 43 +/- 15 IU/l, p = 0.08), but the clinical meaning did not exist. However, in the severe cases, which involved two of following criteria (left main disease, severe occlusion of left or right coronary), the max CPK-MB level was statistically decreased by the combined use of ante- and retrograde cardioplegia (AC; 50 +/- 16, AC + RC; 40 +/- 12 IU/l, p < 0.05). We concluded that the merit of combined use was limited to the cases with severely extended coronary obstructive disease.

Aged↗
PubMed2000

Correlation between the expression of the HNK-1 epitope and cellular invasiveness in prestreak epiblast cells of chick embryos.

During avian gastrulation, certain cells present in the epiblast layer ingress through the basement membrane sealing the basal surface of themselves. Previously we reported that chick prestreak epiblast cells show two different behavioral phenotypes upon reconstituted basement membrane and laminin gel in vitro. Half of the dissociated epiblast cells invade the gel substratum after one-day of culture, whereas the others attach to the gel but do not invade. It is expected that such heterogeneity in the behavior of the epiblast cells reflects some mechanism that sorts the cells into those that will ingress into the blastocoelic cavity and those that will remain in the epiblast layer. To test this hypothesis, we dissociated chick prestreak epiblast cells into single cells, cultured them on the laminin gel, and then stained them with anti-HNK-1 antibody. This antibody binds to an epitope present on half of the prestreak epiblast cells which are thought to differentiate into presumptive mesoendodermal cells. We found that 80% of the invasive epiblast cells were HNK-1-positive whereas 77% of the non-invasive cells were HNK-1 negative. In the case of invasive cells, the edges of the proteolytic holes made by the invasive cells were often stained. These results suggest that the cells expressing the HNK-1 carbohydrate chain are preferentially invasive, and this induces selective ingression of the carrier cells for mesoendodermal differentiation in vivo.

Animals↗
PubMed1999

AP-2beta represses D(1A) dopamine receptor gene transcription in neuro2a cells.

Expression of the D(1A) dopamine receptor in brain is restricted to specific neuronal populations. To investigate the mechanism of this selective expression, we localized a silencer upstream of the human D(1A) gene and identified its binding transcription factor in the D(1A)-negative neural cell line Neuro2a. Using deletion CAT analysis, we narrowed this silencer to the region between nucleotides -561 and -532 relative to the CAP site. This 30-bp region, designated D1AS1, contains a sequence homologous to the AP-2 binding site and binds to a factor that also interacts with the AP-2 consensus sequence. In gel supershift assays, this factor is recognized by anti-AP-2beta antibody. Co-transfection of Neuro2a cells with an AP-2beta expression vector repressed the basal CAT activity of D(1A) promoter-reporter plasmids in a D1AS1-dependent manner. RT-PCR analysis indicated that, among AP-2 family members, Neuro2a cells express only AP-2beta. Furthermore, co-transfection of these cells with decoy oligonucleotides corresponding to the D1AS1 sequence de-repressed the D(1A) gene promoter. Unlike in Neuro2a cells, AP-2beta could not repress the D(1A) promoter in the D(1A)-positive neural cell line, NS20Y. In addition, the expression of AP-2beta in different brain regions does not inversely correlate with that of D(1A) dopamine receptor. These observations taken together indicate that AP-2beta is a repressive transcription factor that acts on the D1AS1 silencer of the D(1A) dopamine receptor gene via some cell-specific mechanism(s) in Neuro2a.

Animals↗
PubMed1999

Identification of three distinct regions of deletion on the long arm of chromosome 11 in childhood acute lymphoblastic leukemia.

Cytogenetic analysis of childhood acute lymphoblastic leukemia (ALL) identified deletions of chromosome arm 11q. These observations led us to analyse the loss of heterozygosity (LOH) of chromosome arm 11q in 113 primary childhood ALL samples using 14 microsatellite markers. LOH was found in 18 (16%) patients. Detailed examination identified three distinct regions of deletion. The first region is flanked by D11S901 and D11S1391 at 11q22-23 containing the ATM gene. Mutational analysis suggested that the altered gene in this region is not the ATM gene. The second region is flanked by D11S614 and D11S924 at 11q23 containing the MLL gene. The third region is flanked by D11S1356 and D11S614 at 11q23 containing the MLL gene. All the cases with LOH at MLL locus lacked detectable MLL gene rearrangements. In addition, 20 children have been studied both at initial diagnosis and relapse; none of the individuals who relapsed acquired LOH of 11q, suggesting that 11q deletions were infrequently involved in the progression of childhood ALL. Children with 11q LOH had a good response to induction chemotherapy (P=0.015). These data suggest that alterations of putative tumor suppressor genes on 11q are important events in development of childhood ALL. Our map provides important information toward cloning putative tumor suppressor genes associated with childhood ALL.

Child↗
PubMed1999

Significance of Steroid Sulfatase Expression in Human Breast Cancer.

The sulfatase pathway has been thought to be a primary means of local production of estrone in human breast cancer tissue. We measured steroid sulfatase (STS) mRNA levels in 97 breast cancers and evaluated its association with disease-free survival. High levels of STS mRNA proved to be a significant predictor of reduced relapse-free survival, both as a continuous variable (log STS mRNA; P = 0.028) and as a dichotomous variable with an optimized cutoff point (P=0.002). In multivariate analysis a high level of STS mRNA was an independent factor for predicting relapse-free survival. These results suggest a putative role of STS in breast cancer growth and metastasis, and administration of sulfatase inhibitors to breast cancer patients with high levels of STS mRNA might be an additional treatment option.

Journal Article↗