Biomedical subjects

M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 397 records · Page 22Linked to original sources

PubMed1997

Treatment of a degloved hand injury by arteriovenous anastomosis: a case report.

It goes without saying that the optimal therapy for reconstruction of degloving injuries is to employ the tissues that were avulsed. However, it is difficult to evaluate the circulation and viability of avulsed tissues, and in the case of conservative treatment it is quite common for the avulsed tissues to become necrotic. This often necessitates a second reconstructive operation. We report a case of degloving injury of the hand. We performed reconstruction by arteriovenous anastomosis of a superficial vein in the avulsed skin flap and a superficial vein of the hand with the radial artery. We were thereby able to arterialize and salvage the avulsed skin flap on the back and palm of the hand, and the results were cosmetically and functionally satisfactory.

Aged↗

PubMed1997

Treatment of giant pigmented nevus using artificial dermis and a secondary skin graft from the scalp.

From January 1994 to October 1995, 5 patients with congenital giant pigmented nevi were treated using artificial dermis with a secondary skin graft from the scalp. The nevus was excised in full thickness and the open wound was grafted with artificial dermis. About 3 weeks later, thin split-thickness skin grafting on the newly synthesized, dermis-like tissue was required. We chose the scalp as the donor of the secondary skin graft. Epithelialization of each donor site was completed within 1 week. In addition, the donor site was not complicated with alopecia or hypertrophic scars. Morbidity at the donor site was minimized and favorable tissue quality of the grafted skin was obtained. The clinical results revealed that the scalp was a favorable donor of a secondary skin graft for the treatment of giant pigmented nevus with artificial dermis.

Adolescent↗

PubMed1997

Bactericidal activity of a fermented hot-water extract from Stevia rebaudiana Bertoni towards enterohemorrhagic Escherichia coli O157:H7 and other food-borne pathogenic bacteria.

A fermented aqueous extract from Stevia rebaudiana Bertoni showed strong bactericidal activity towards a wide range of food-borne pathogenic bacteria including enterohemorrhagic Escherichia coli O157:H7. The colony-forming ability of the food-borne pathogenic bacteria tested so far was reduced to < 10(-7) when exposed to > or = 40% (v/v) solutions of the fermented extract at 37 C for 2 hr. Secretion of verocytotoxin 1 and 2 by enterohemorrhagic E. coli was also diminished by fermented extract at a concentration of > or = 10% (v/v). In contrast, the fermented extract did not significantly kill Bifidobacteria or Lactobacilli. The active principle(s) of the fermented Stevia extract were bactericidal under acidic conditions.

Bacterial Toxins↗

PubMed1997

Early detection of prune belly syndrome in utero by ultrasonography.

A report is presented of a male infant with prune belly syndrome (PBS) in whom bladder enlargement was detected by ultrasound (US) as early as 13 weeks of gestation. Subsequent fetal US identified progressive urinary tract dilatation, ascites and oligohydramnios. At 22 weeks, the fetal bladder was drained under US guidance. A gradual resolution of oligohydramnios was detected on US performed after 26 weeks of gestation. Delivery by cesarean section was performed at 34 weeks of gestation. The newborn had typical features of PBS with a vesico-cutaneous fistula but did not show respiratory distress. Imaging studies showed hypoplastic left kidney, slightly dysplastic but functioning right kidney, megaureter, megacystis, vesicoureteral reflux and dilated prostatic urethra. The early detection of genitourinary system abnormalities and serial US suggest that a distal urethral obstruction may be the underlying mechanism of PBS. Spontaneous (or therapeutic) intra-uterine decompression of the bladder might ameliorate obstructive nephropathy and oligohydramnios, allowing adequate lung development.

Adult↗

PubMed1997

Cholesteatoma of the ureter: a case report.

A 72-year-old man complained of general fatigue and had low grade fever. Ultrasonography, excretory urography, retrograde urography, and computed tomography revealed left hydronephrosis due to a middle ureteral tumor. A nephroureterectomy was performed. The histological diagnosis was hyperkeratosis with a cholesteatoma.

Aged↗

PubMed1997

Effect of ventricular pacing on coronary blood flow in patients with normal coronary arteries.

Although ventricular pacing is thought to produce impairment of left ventricular function by altering the sequence of ventricular activation and AV dyssynchrony, little is known about the effect of ventricular pacing on coronary blood flow. We measured coronary blood flow and coronary flow reserve in the left anterior descending coronary artery during sinus rhythm, and during both atrial and ventricular pacing at a rate of 100 ppm in 14 patients with normal coronary arteries. The double product increased significantly during both types of pacing. Coronary arterial diameter during ventricular pacing significantly increased compared to that during both sinus rhythm and atrial pacing. Coronary flow velocity during ventricular pacing was significantly lower compared to that during both sinus rhythm and atrial pacing. Coronary blood flow increased significantly during atrial pacing (30.7% +/- 12.1%; P < 0.001), but not significantly during ventricular pacing (23.6% +/- 47.0%; P = ns). While coronary flow reserve during both atrial (3.9 +/- 1.3) and ventricular pacing (3.8 +/- 0.9) was lower compared to its value during sinus rhythm (4.5 +/- 1.5), the difference was not significant. There was a significant positive correlation between the coronary flow reserve during sinus rhythm and the increase of coronary blood flow during ventricular pacing (R2 = 0.78; P < 0.001). We concluded that an increase in coronary blood flow during ventricular pacing is not a common finding regardless of the increase in metabolic demand. The increase of coronary blood flow during ventricular pacing was less in patients with a reduced coronary flow reserve. These findings suggest that preservation of AV synchrony and the presence of a normal sequence of ventricular activation may play an important role in preserving coronary blood flow in this subset of patients.

Adult↗

PubMed1997

Quantitative, non-invasive assessment of ventricular septal defect shunt flow by measuring proximal isovelocity surface area on colour Doppler mapping.

OBJECTIVE: To determine whether the proximal isovelocity surface area (PISA) method could be applied to estimate the magnitude of ventricular septal defect (VSD) shunt flow. DESIGN: Prospective analysis of clinical, echocardiographic, and angiographic data. SETTING: University hospital. PATIENTS: 14 children with VSD. METHODS: Colour Doppler images of VSD shunt flow were obtained in parasternal long axis view, four chamber view or both, adjusted to provide the best imaging of flow. The VSD shunt flow rate and shunt volume were calculated as follows: shunt flow rate (SFR) = 2 pi r2 V/BSA in ml/s/m2; shunt volume = SFR x shunt duration time. The shunt volume, shunt fraction, and pulmonary to systemic flow ratio (Qp:Qs) were confirmed by cardiac catheterisation. RESULTS: There was a correlation between shunt variables determined by PISA and those by catheterisation, including shunt volume (r = 0.78, P = 0.001) and shunt fraction (r = 0.74, P = 0.003). Qp:Qs was also significantly correlated with SFR (r = 0.79, P = 0.0007). The SFR was significantly different between the four patients with Qp:Qs < 2.0 (mean (SD) 54 (33) ml/s/m2) and the 10 patients with Qp:Qs > 2.0 (186 (69) ml/s/m2) (P = 0.004). CONCLUSIONS: These data suggest that the PISA method is a reliable non-invasive investigation for the quantitative assessment of VSD shunt flow and provides important information for decisions regarding surgical repair.

Cardiac Catheterization↗

PubMed1997

Role of cytosolic Ca2+ and protein kinase C in developing myogenic contraction in isolated rat small arteries.

Cytosolic Ca2+ and protein kinase C (PKC) may regulate the myogenic contraction of arterial myocytes. The role of these second messengers is examined in skeletal muscle small arteries, which have strong myogenic activity, and mesenteric small arteries, which have weak myogenic activity. The vessels were isolated and cannulated. The inner diameter was measured with a video-digitizing system. Cytosolic Ca2+ concentration was assessed by fura 2. Skeletal muscle small arteries dilated from 122 +/- 6 to 153 +/- 6 microm immediately after the transmural pressure change from 40 to 100 mmHg and constricted to 121 +/- 5 microm (myogenic contraction) with an increase in the 340/380 fluorescence ratio (by approximately 33%) in control vessels. Nifedipine abolished myogenic contraction and the increase in the fluorescence ratio. PKC inhibitors (H7 and staurosporine) abolished myogenic contraction but did not depress the increase in the fluorescence ratio. In mesenteric small arteries, myogenic contraction was insignificant in control vessels. A relatively low dose of PKC activator (4.4 +/- 1.4 nmol/l) elicited myogenic contraction, but a higher dose (21 +/- 6 nmol/l) depressed it. Thus the cytosolic Ca2+ increase and PKC activity may cooperatively act on the myogenic contraction of skeletal muscle small arteries. The activity of PKC should play an important role in myogenic contraction of rat small arteries.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1997

Assessment of endogenous nitric oxide formation in newborns: measurement of urinary nitrite and nitrate concentrations.

We measured the urinary nitrite and nitrate (NOx-) excretion, an index of endogenous nitric oxide formation, in term and preterm newborns on the 1st and 4th days of age. In the infants of both groups, the urinary NOx- excretion significantly increased from the 1st to the 4th day. The urinary NOx- excretion in preterm infants was significantly higher as compared with term babies on both days. Furthermore, the urinary NOx- excretion was significantly elevated in preterm infants with respiratory distress syndrome as compared with those without cardiopulmonary complications on the 4th day. These changes of urinary NOx- excretion in newborns strongly suggest the presence of an active physiological role for nitric oxide in the circulatory adaptation to extrauterine life.

Female↗

PubMed1997

2-(3-Pyridyl)thiazolidine-4-carboxamides. 1. Novel orally active antagonists of platelet-activating factor (PAF).

In a search for novel platelet-activating factor (PAF) antagonists, we found that 1-(3-phenylpropyl)-4-[2-(3-pyridyl)thiazolidine-4-carbonyl] piperazine (3x) showed in vitro and in vivo PAF-antagonistic activities. Introduction of functional groups at the benzylic methylene carbon of 3x afforded some compounds with more potent PAF-antagonistic activity than 3x. Among them 1-(3-methyl-3-phenylbutyl)-4-[2-(3-pyridyl) thiazolidine-4-carbonyl]-piperazine fumarate (3al, YM264) was found to be one of the most potent PAF antagonists.

Animals↗

PubMed1997

The rise time of the monophasic action potential--a new index of local use-dependent conductivity by sodium channel blockers in human myocardium.

The kinetics of global use-dependent conduction slowing produced by sodium channel blockers in the human heart, estimated as a change in the QRS width, are known to be similar to those of use-dependent block of the maximum rate of depolarization in in vitro studies. However, the kinetics of the regional use-dependent decrease in conductivity have not been investigated. We examined whether the rise time of the monophasic action potential would be clinically useful as a marker of the local use-dependent decrease in conductivity by sodium channel blockers. In 12 patients without organic heart disease, monophasic action potentials (MAPs) were recorded at the right ventricular endocardium using a contact electrode before and after the administration of disopyramide (n = 6, 2 mg/kg, i.v.) or pilsicainide (class Ic agents, n = 4, 1 mg/kg, i.v., and n = 2, 150 mg, po) while the stimulus frequency was abruptly increased from 100/min to 150/min. The rise time, defined as the interval from the pacing pulse to the first peak deflection of the monophasic action potential, and the ORS width were measured simultaneously. In the absence of the sodium channel blockers, the abrupt increase in heart rate did not alter the QRS width or the rise time. In the presence of the agents, both variables were lengthened exponentially. The rate constants of onset changes in the QRS width and the rise time were 2.1 +/- 0.5 beats and 2.1 +/- 0.4 beats after the administration of disopyramide, and 7.5 +/- 3.0 beats and 8.2 +/- 4.0 beats after pilsicainide, respectively. The rate constant of the rise time was closely correlated with that of the QRS width. The present results are very closely comparable with the onset rate constants of use-dependent block of the maximum rate of depolarization in in vitro studies. These results suggest that (1) the rise time is a good indicator of local use-dependent decrease in conductivity by sodium channel blockers in human hearts and (2) the local use-dependent decrease in conductivity has kinetics similar to those of use-dependent sodium channel blocks.

Action Potentials↗

PubMed1997

Enzymatic properties of double mutant enzymes at Asp51 and Trp49 and Asp51 and Tyr57 of RNase Rh from Rhizopus niveus.

Mutation of Asp51 of a base-nonspecific RNase, RNase Rh, to Ser, Thr, or Gln makes the enzyme more preferential for the dinucleoside phosphate (XpY) having G and C at the 5'-side (X). On the other hand the mutation of one of the B1 site components, Tyr57 to Trp, and Trp49 to Phe makes the enzyme more preferential for purine bases and pyrimidine bases, respectively. In this study, to obtain more specific RNases and RNases with different base specificity, we prepared double-mutant enzymes that have Ser, Thr, and Asn at the 51st position and Trp at the 57th position or Phe at the 49th position, and their enzymatic specificities were studied with XpYs as substrates. The double-mutant enzymes D51SY57W and D51TY57W are more guanylic acid preferential than the mother single-mutant enzymes, D51S and D51T, respectively. They are extremely guanylic preferential RNases. D51NY57W is more a guanylic acid preferential enzyme than D51N, but cytidylic acid preference is of a similar order to that of D51N. The double mutant enzymes D51NW49F and D51TW49F showed an increased cytidylic acid preference as well as guanylic acid preference as compared to the mother single-mutant enzymes, D51T and D51N. The results of analysis of base specificity by the release of mononucleotides from RNA and the rates of hydrolysis of homopolynucleotides led to the same conclusion as in the case of the hydrolysis of XpY.

Dinucleoside Phosphates↗

PubMed1997

Avian influenza A virus induced stunting syndrome-like disease in chicks.

Two-day-old specific-pathogen free chicks were inoculated with type A influenza virus (A/whistling swan/Shimane/499/83 (H5N3) through the air sac. Inoculated chicks showed mild to severe diarrhea and lesions of pancreatitis and atrophy of the pancreas, thymus and bursa of Fabricius. One chick died on each of days 4, 6 and 14 postinoculation (PI). Reduced weight gain was conspicuous from day 22 PI. Positive immunoreaction to the virus antigen was detected in the pancreas, kidneys, liver, lungs and air sacs, and cecal lamina propria. Virus recovery persisted longer in the pancreas. Some of these findings conformed to those of stunting syndrome.

Air Sacs↗

PubMed1997

Effects of soft X-ray irradiation on NK cell activity and the percentage of asialo GM1-positive cells in spleen cells of mice.

Effects of soft X-ray irradiation on the natural killer (NK) cell activity and the percentage of asialo GM1-positive cells of spleen cells in mice were investigated by using a soft X-ray generator intended for non-destructive radiological examination. Soft X-ray irradiation in graded doses of more than 25.8 mC/kg indicated dose dependent reductions in the NK cell activity in the spleen of irradiated mice. Significant reductions in the population of asialo GM1-positive cells in spleen cells were also observed. These results suggest that a soft X-ray generator could also be useful in immuno-irradiation studies.

Animals↗

PubMed1997

Effect of 1,3-dithia-2-thioxo-cyclopent-4-ene and its derivatives on liver injury induced by carbon tetrachloride and orotic acid in rats.

The protective effect of 1,3-dithia-2-thioxo-cyclopent-4-ene (DT827A) and its two derivatives of 4-phenyl-1,3-dithia-2-thioxo-cyclopent-4-ene (DT827B) and 4-(4-fluorophenyl)-1,3-dithia-2-thioxo-cyclopent-4-ene (DT827C) on liver injury induced by carbon tetrachloride (CCl4) and orotic acid was studied using male rats. The approximate lethal doses were about 100 mg/kg for DT827A-treated animals and more than 800 mg/kg for the other two compounds-treated groups. Single oral administration of the three test compounds at the dose levels of 2 and 10 mg/kg 1 hour before CCl4 exposure revealed a protective effect on the findings of centrolobular necrosis, balloon cells and macrophage infiltration in histopathological findings in livers in the order of DT827B-treated rats > DT827A-treated rats > DT827C-treated rats. Repeated oral administration of the compounds at the dose levels of 2 and 10 mg/kg/day for 10 consecutive days revealed a protective effect against liver injury on the findings of centrolobular necrosis, balloon cells and macrophage infiltration in the order of DT827B-treated rats > DT827A-treated rats [symbol: see text] DT827C-treated rats. Simultaneous administration of the compounds at the dose level of 10 mg/kg/day together with a high sucrose diet containing orotic acid for 12 days revealed an inhibitory effect on fatty liver formation in the order of DT827B-treated rats > DT827C-treated rats > DT827A-treated rats. A hepatoprotective potential of the DT827 series compounds was suggested under the conditions of these studies, and DT827B was considered to be the most effective.

Administration, Oral↗

PubMed1997

[Ornithine induced retinopathy in the rat--1. Histopathological study on the retinal pigment epithelium].

An intravitreal injection of a small amount of 1-ornithine hydrochloride damages the retinal pigment epithelium (RPE) selectively in monkey eyes. In this paper, we examined the rat eye and observed similar results. Clinically, retinal edema appeared immediately after injection and showed hyperfluorescence on a fluorescein angiograph after 3 days. Histopathologically, RPE showed marked swelling 3 hours after injection, then became necrotic and disappeared gradually. One month after injection, retinal structure was maintained in the area where RPE regenerated to cover Bruch's membrane, but in the area where RPE cells disappeared, the photoreceptor cells and choriocapillaris degenerated and finally disappeared. In the eyes injected intravitreally with NaCl solution of equivalent osmosis microvacuoles were seen but no necrotic change in RPE. Thus, a small amount of ornithine damaged RPE selectively, and induced disappearance of the photoreceptors and choriocapillaris secondarily.

Animals↗

PubMed1997

Quantitative evaluation of the IL-1 beta and IL-1 receptor antagonist obtained from BALF macrophages in patients with interstitial lung diseases.

Our previous reports demonstrated the concomitant release of IL-1 beta and IL-1 inhibitory activity in the culture supernatants of BALF macrophages in both healthy subjects and patients with interstitial lung diseases. IL-1 inhibitory activities decreased in healthy smokers (HS), and patients with sarcoidosis (Sar), or idiopathic pulmonary fibrosis (IPF), compared with those in healthy nonsmokers (HNS), though an increase in IL-1 beta release was not detected. IL-1 inhibitory activity was mainly characterized as IL-1 receptor antagonist (IL-1ra). In this study, we confirmed a decrease in IL-1ra in terms of the amounts of protein (enzyme-linked immunoassay) and gene transcripts (reverse transcriptase polymerase chain reaction followed by high performance liquid chromatography). Imbalance between IL-1ra and IL-1 beta was expressed as a molar ratio of IL-1ra/IL-1 beta protein: (Sar; 4.20 +/- 2.06, IPF; 4.26 +/- 3.41, HS; 3.44 +/- 3.09 versus NS 8.33 +/- 2.77: P < 0.001). These results were similar in terms of the amounts of gene transcripts. In conclusion, the imbalance of IL-1 beta and IL-1ra production was confirmed at three levels: biological activity, amounts of protein, and gene transcript obtained from BALF macrophages in chronic inflammatory processes in the lungs.

Adult↗

PubMed1997

[Ornithine induced retinopathy in rat--2. Process of disappearance of choriocapillaris].

We observed the process of disappearance of the choriocapillaris after loss of the retinal pigment epithelium (RPE) induced by intravitreal injection or ornithine. Three hours after administration of ornithine, the RPE cells swelled remarkably in the posterior pole, but, the endothelial cells of the choriocapillaris remained intact. At 3 days, the RPE cells became necrotic, but the choriocapillaris still preserved its in normal appearance. At 7 days, RPE disappeared completely in the posterior pole and the choriocapillaris displayed evidence of atrophy; the swollen lumen of the choriocapillaris became narrow the cytoplasm of the endothelium was swollen, and the number of fenestrae was reduced. On the other hand, these changes were not seen where the RPE remained. At 14 days, in the posterior pole, the lumen of the choriocapillaris occluded by the swollen endothelial cells. At 28 days, the choriocapillaris completely disappeared and the large choroidal vessel was directly in contact with Bruch's membrane. These results showed that the RPE is correlated with the presence of the choriocapillaris.

Animals↗