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Biomedical subjects

A Taguchi

Publications and source records attributed to A Taguchi.

At least 73 records · Page 4Linked to original sources
PubMed1998

Simple bone cyst: investigation on the presence of gas in the cavity using computed tomography--review of 52 cases.

OBJECTIVE: The purpose of this study was to evaluate whether gas is present in the cavities of simple bone cysts. STUDY DESIGN: Computed tomographic images of 52 simple bone cyst cases were reviewed and compared with the findings at surgery. RESULTS: Whereas gas was confirmed at the time of surgery in 28 cases, no computed tomographic images indicated the presence of gas in the cavity. Bone expansion was noted in 13 of these 28 cases. CONCLUSIONS: From these findings, we concluded that the presence of gas in the simple bone cyst cavity at surgery has been erroneously interpreted.

Adolescent↗
PubMed1998

Argos induces programmed cell death in the developing Drosophila eye by inhibition of the Ras pathway.

We studied the role of Ras signaling in the regulation of cell death during Drosophila eye development. Overexpression of Argos, a diffusible inhibitor of the EGF receptor and Ras signaling, caused excessive cell death in developing eyes at pupal stages. The Argos-induced cell death was suppressed by coexpression of the anti-apoptotic genes p35, diap1, or diap2 in the eye as well as by the Df(3L)H99 chromosomal deletion that lacks three apoptosis-inducing genes, reaper, head involution defective (hid) and grim. Transient misexpression of the activated Ras1 protein (Ras1V12) later in pupal development suppressed the Argos-induced cell death. Thus, Argos-induced cell death seemed to have resulted from the suppression of the anti-apoptotic function of Ras. Conversely, cell death induced by overexpression of Hid was suppressed by gain-of-function mutations of the genes coding for MEK and ERK. These results support the idea that Ras signaling functions in two distinct processes during eye development, first triggering the recruitment of cells and later negatively regulating cell death.

Animals↗
PubMed1998

Radiofrequency catheter ablation of concealed atrioventricular accessory pathways using a "simultaneous pacing method".

The retrograde atrial potential at a successful ablation site is usually obscured by the wide and large ventricular potential during atrioventricular reentrant tachycardia or ventricular pacing, which makes it difficult to determine the appropriate ablation site for a concealed accessory pathway. A pacing maneuver named the "simultaneous pacing method" is proposed herein to differentiate the retrograde atrial potential from the ventricular potential for a successful ablation of the concealed accessory pathway. Catheter ablation was performed in 12 patients with a single left free-wall concealed accessory pathway. The atrial insertion site was determined by the simultaneous pacing method in six patients (group I) and by ventricular pacing in six patients (group II). In the simultaneous pacing method, electrograms recorded during ventricular pacing in the earliest retrograde atrial activation site are a fusion of the ventricular potential and the following retrograde atrial potential. When atrial and ventricular pacings are performed simultaneously (simultaneous pacing), the end portion of the electrograms recorded at the same site is solely the ventricular component, because atrial is activated earlier. The atrial potential can be confirmed during ventricular pacing in comparison with the electrograms during the "simultaneous pacing." Radiofrequency catheter ablation was successful in eliminating conduction through the accessory pathway in all 12 patients. The radiofrequency applications in group I were significantly fewer than those in group II (1.7 +/- 1.0 in group I, 5.3 +/- 3.2 in group II, P < 0.05). The total procedure time in group I was significantly shorter than in group II (57.8 +/- 15.7 vs 106.7 +/- 41.6 mins in group II, respectively, P < 0.05). The fluoroscopy time in group I was significantly shorter than in group II (54.0 +/- 7.9 vs 81.3 +/- 26.3 mins, respectively, P < 0.05). We were able to determine the atrial insertion site of accessory pathways by the simultaneous pacing method. The simultaneous pacing method was useful in eliminating concealed left free-wall accessory pathways.

Adult↗
PubMed1998

Mid-diastolic potential is related to the reentrant circuit in a patient with verapamil-sensitive idiopathic left ventricular tachycardia.

We report a case of verapamil-sensitive idiopathic ventricular tachycardia in which a mid-diastolic potential (MDP) 45 msec preceding the Purkinje potential (P potential) was recorded. Pacing during the tachycardia caused concealed entrainment, and the stimulus-QRS interval was equal to the P potential-QRS interval. The interval between the last pacing stimulus and the next P potential (postpacing interval) was longer than the ventricular tachycardia cycle length, but the MDP was orthodromically activated. These findings suggest that the MDP was on the reentrant circuit and the P potential was not on the reentrant circuit, but a bystander.

Adult↗
PubMed1998

Correlation between the drinkability of beer and gastric emptying.

A subjective evaluation of beer drinkability and the degree of stomach fullness were found to correlate with the relaxed cross-sectional area of the pylorus antrum measured by real-time ultrasonography. Five kinds of beer with a different malt/adjuncts ratio and degree of attenuation were used. Each beer was given to 9 healthy volunteers at the rate of 3 ml/kg/15 min, and they each recorded the degree of stomach fullness, desire to drink and tastiness every 30 min. With increasing volume drunk, the degree of tastiness and desire to drink were lowered, and the degree of stomach fullness raised. The relaxed cross-sectional area of the pylorus antrum measured by an ultrasonic image analyzer every 30 min was highly correlated with the degree of stomach fullness, tastiness of the beer, and desire to drink (p = 0.0021, < 0.0001, 0.001). The beer giving the lowest degree of stomach fullness was appraised to be tasty and highly drinkable. These findings suggest that the rate of gastric emptying is one of the factors determining the drinkability of beer, and that measurement of the relaxed cross-sectional area of the pylorus antrum is useful to evaluate stomach fullness during beer drinking.

Adult↗
PubMed1997

Intravascular ultrasound findings after successful primary angioplasty for acute myocardial infarction: predictors of abrupt occlusion.

OBJECTIVES: This study sought to evaluate the intravascular structure as depicted by intravascular ultrasound after successful primary angioplasty (i.e., without thrombolytic therapy) for acute myocardial infarction and to investigate the related predictors of acute coronary occlusion. BACKGROUND: The usefulness of primary angioplasty for acute myocardial infarction is still limited by early reocclusion. There are few data regarding the intravascular ultrasound findings after primary angioplasty. METHODS: Intravascular ultrasound was performed in 27 patients after successful primary angioplasty. Repeat coronary angiography was performed 15 min later, on the following day and 1 month after angioplasty. RESULTS: Abrupt occlusion occurred in 8 of 27 patients. Angiographic variables in patients with versus those without abrupt occlusion were not significantly different. Intravascular ultrasound disclosed a significantly smaller lumen area ([mean +/- SD] 2.49 +/- 0.72 vs. 5.06 +/- 1.52 mm2, p < 0.001) and a significantly greater percent plaque area (80.5 +/- 9.1% vs. 63.7 +/- 7.8%, p < 0.001) in patients with abrupt occlusion. There was no significant difference in external elastic membrane cross-sectional area. We classified the ultrasound appearance of the intravascular structure as smooth, irregular or filled. Abrupt occlusion occurred in none of 6 patients with a smooth intravascular structure, 24% of 17 patients with an irregular structure and in all 4 with a filled structure (p < 0.05). In the latter group, the lumen was filled with bright speckled or low echogenic material, although angiography revealed excellent coronary dilation in all these arteries. CONCLUSIONS: Intravascular ultrasound revealed a narrow lumen in coronary arteries showing abrupt occlusion after successful primary angioplasty, even though angiography disclosed successful dilation. Arteries with a lumen filled with bright speckled or low echogenic material frequently develop abrupt occlusion.

Aged↗
PubMed1997

Radiographic evaluation of possible etiology of diffuse sclerosing osteomyelitis of the mandible.

To examine the cause and site of origin of diffuse sclerosing osteomyelitis of the mandible, we compared various radiographic findings for the mandibular lesions in 20 patients with diffuse sclerosing osteomyelitis with those in 48 patients with osteomyelitis caused by bacterial infection. In osteomyelitis of infectious origin, a typical radiographic feature was a radiolucent lesion spreading in the cancellous bone, with cortical bone perforation and lamellated periosteal reaction. In diffuse sclerosing osteomyelitis, intermingled sclerotic and osteolytic lesions with solid periosteal reaction or external bone resorption were a common finding, and in some patients the cortical bone was initially affected by the fresh or recurrent lesion. Based on these distinct differences, we suggest that the cause of diffuse sclerosing osteomyelitis is not bacterial infection and that the site of origin is not in the bone but in the periosteum.

Bacterial Infections↗
PubMed1997

Trabecular bone pattern of the mandible. Comparison of panoramic radiography with computed tomography.

OBJECTIVES: To analyse the possible correlation between the trabecular bone pattern of the edentulous mandible visualized by panoramic radiography and the bone mineral density (BMD) measured by computed tomography (CT). METHODS: Panoramic radiography and CT were performed on 28 patients with edentulous mandibles. The trabecular bone pattern of 47 regions on the panoramic radiographs was classified into one of five grades. BMD was measured within circular regions of interest on the axial CT images in the corresponding trabecular area. The gradings were correlated with the CT values using one-way analysis of variance. RESULTS: There was a significant correlation between the grade of the trabecular bone pattern and the BMD (P < 0.0001). CONCLUSION: The proposed classification for the trabecular bone pattern on panoramic radiographs might be a useful aid for the evaluation of the edentulous mandible prior to implant placement.

Adult↗
PubMed1997

Observer agreement in the assessment of mandibular trabecular bone pattern from panoramic radiographs.

OBJECTIVES: To study the observer agreement in the assessment of trabecular pattern of the mandible from panoramic radiographs. METHODS: Seven observers were asked to classify the trabecular pattern of 100 edentulous regions of the mandible in 80 randomly selected panoramic radiographs into one of five grades with the aid of a written description and reference images. Intra- and interobserver agreement was calculated as overall agreement and Kappa index. RESULTS: The intra-observer agreement varied between 65% and 79%. The Kappa index for intra-observer agreement was moderate for three observers and substantial for four. For all seven observers, it varied according to the grade of trabecular bone pattern, but the majority deviated from each other by only one grade. CONCLUSION: The relatively high rates of observer agreement indicate that panoramic radiography can be used for the clinical assessment of the trabecular pattern of the mandible.

Adult↗
PubMed1997

[Comparison of the number of parameters using nonlinear iteration methods for compartment model analysis with 18F-FDG brain PET].

In the analysis of the brain kinetic images with 18F-FDG, compartment models with 3 or 4 parameters and an estimation method of nonlinear least squares (NLS) have been applied. We compared the Simplex method and the modified Marquardt method as an iterative NLS algorithm on the simulation data with variable noise. The estimated k-values were equal in the both algorithms. The calculation with modified Marquardt method was three times faster than that of the Simplex method. The dependence of modified Marquardt estimates on the initial values was larger than that of the Simplex, but the permissible initial value range was wide enough for clinical data. Therefore, the modified Marquardt method was found to be more suitable for the compartment model analysis of 18F-FDG than the Simplex method. We also compared the 3-parameter with 4-parameter models for 45 min and 120 min data acquired after administration. The 3-parameter model was suitable for the 45-minute data acquisition, and the 4-parameter model was suitable for the 120-minute data acquisition.

Algorithms↗
PubMed1997

The alginate reduce the postprandial glycaemic response by forming a gel with dietary calcium in the stomach of the rat.

Soluble dietary fibers include an alginate which reduces the postprandial glycaemic response. We speculated that the cause of the reduction of alginate on the glycaemic response is the gel formation of alginate with dietary calcium in the stomach. The aim of the present study was to confirm our hypothesis and to examine the effect of the sugar composition of alginates on the glycaemic response and the effect of continuous feeding of alginate-containing diet to rats. Diabetic rats were made by injecting streptozotocin (STZ) intravenously. These rats were fed 5 g of the experimental diet with or without sodium alginate and with or without calcium after overnight fasting. In the rats fed the diet containing both alginate and calcium, the postprandial glycaemic response was lower than in the rats fed other diets and gastric contents were retained as gel form. Three beta-d-mannuronic acid (M) to alpha-l-guluronic acid (G) (ratios (M/G 0.5, 1.3, 2.1) of alginates were not associated with the acute glycaemic response in STZ rats. Then, we fed normal rats with an alginate-free or one of three respective alginate-containing diets for 4 weeks. During the first 2 weeks of the feeding period, the total amount of food intake of rats fed the G-rich alginate diet was smaller than that of rats in the other dietary groups. Moreover, the weight of the dorsal abdominal adipose tissue of rats given the G-rich alginate diet was the lowest among the dietary groups. We conclude that the reductive effect of alginate feeding on the postprandial glycaemic response was not caused only by their inherent viscosity, but also by gel formation with dietary calcium in the stomach. Moreover, it is necessary to pay attention to the M/G ratio of alginates for estimating their physiological effect.

Adipose Tissue↗
PubMed1997

Evolutionarily conserved mechanisms regulating neural development: lessons from the development of Drosophila peripheral nervous systems.

Functions of genes regulating the development of Drosophila peripheral nervous systems are summarized herein. These genes can be classified into 6 groups: <1> prepattern genes, <2> proneural genes, <3> neurogenic genes, <4> neuronal precursor genes, <5> neuronal precursor type selector genes, and <6> cell-division and lineage genes. The mechanisms described herein provide excellent paradigms in the regulation of the development of other tissues in Drosophila, as well as in other organisms, including vertebrates. The roles of two different inhibitory mechanisms, i.e. Notch-signaling and Argos, in the development of Drosophila neural precursor cells are also discussed.

Animals↗
PubMed1997

[Anesthetic management of a patient with Duchenne's muscular dystrophy undergoing radical repair for tetralogy of Fallot].

This report describes a 13-month-old-girl with Duchenne's muscular dystrophy (DMD) who had radical repair for tetralogy of Fallot safely. Patients with DMD are considered to be at risk of malignant hyperthermia (MH). Drugs for induction and maintenance were chosen from a list of agents rarely associated with MH. To wash out the inhalation anesthetics from the equipment, oxygen was circulated continuously for 24 hours. Dantrolene sodium was kept readily available in case of MH occurrence. Differential diagnosis during surgery is difficult in term of the episodes of MH and complications of cardiac surgery, as cardiac surgery is also associated with tachycardia, tachyarrhythmias, metabolic asidosis and red colored urine, which are frequently accompanied by MH. Although increased levels of CK, GOT, LDH and myoglobin strongly support the diagnosis of MH, such evidence can only be confirmed after operation. Fortunately, these factors recovered to the normal range without treatment by dantrolene sodium. During the cardiac surgery, treatment of MH may be delayed due to its late confirmation.

Anesthesia, General↗
PubMed1996

Effect of systemic zinc administration on delayed neuronal death in the gerbil hippocampus.

The divalent cation zinc has been reported to possess several physiological properties such as blocking apoptotic cell death through an inhibitory effect on Ca(2+)-Mg2+ endonuclease activity, or modulating the neurotoxicity via glutamate receptor subtypes. In the present study, we investigated the effect of peripherally injected zinc on delayed neuronal death seen in the hippocampus after transient global ischemia, in order to elucidate a possible beneficial role on zinc in ischemic neuronal cell death. Forty-five adult Mongolian gerbils of both sexes underwent transient bilateral clipping of the common carotid arteries for 3 min. In the pretreated animals, ZnCl2 (20 mg/kg) was injected subcutaneously once, 1 h before ischemia (superacute group; n = 6) or twice at 24 and 48 h before ischemia (subacute group; n = 14). Histological survey was carried out 3 days later by in situ DNA fragmentation method and 4 days later by hematoxylin-eosin staining by semiquantatively counting dead neurons in the CA1 sector. Subacute zinc pre-administration significantly reduced the nuclear damage and subsequent neuronal death; however, superacutely pre-administered zinc did not protect hippocampal neurons against ischemia but it did not aggravate the effect of ischemia, either. The present study suggested that transfer of exogenous zinc into the intracellular space is required for neuroprotection, presumably via the anti-endonuclease activity.

Animals↗
PubMed1996

Bifemelane hydrochloride enhances 'ischemic tolerance' phenomenon in gerbil hippocampal CA1 neurons.

Neurons are so vulnerable to ischemic insults that transient forebrain ischemia for 5 min killed most CA1 neurons in the gerbil hippocampus (surviving neurons: 4%). In contrast, 2 days after a nonlethal challenge of 2-min ischemia, 51% of CA1 neurons became resistant to subsequent, otherwise lethal ischemia for 5 min. Bifemelane hydrochloride (20 mg/kg, i.p.), which helps ischemic brain recover from oxidative stress and inhibition of protein synthesis, significantly enhanced the 'ischemic tolerance' phenomenon if injected 1 day after 2-min ischemia: 94% of neurons survived after 5-min ischemia. This finding carries implications for possible preventive treatment following warning signs of transient ischemic attack.

Adaptation, Physiological↗
PubMed1996

Effect of immunosuppressant FK506 on ischemia-induced degeneration of hippocampal neurons in gerbils.

To evaluate the effect of FK506 on delayed neuronal death in gerbils after forebrain ischemia, 84 adult Mongolian gerbils were used in this study. Transient forebrain ischemia was induced by clipping common carotid arteries bilaterally for 5 minutes. One hour after reperfusion we intraperitoneally injected FK506 (1.0 mg/kg), cyclosporin A (CsA) (10.0 mg/kg) or the vehicle solution into each gerbil. In one group, each agent was additionally administered daily 3 more times at 24, 48 and 72 hours after ischemia. The gerbils were killed 4 days or 10 days after transient ischemia, and damage to their hippocampal pyramidal cells was histologically assessed. Additionally, the body temperature was measured following administration of each drug to investigate drug-induced hypothermia. Post-ischemic repeated treatment with FK506 significantly (p < 0.01) reduced degeneration of hippocampal neurons. However, partial treatment did not modify neuronal degeneration. CsA did not show a neuroprotective effect in this study. Drug-induced mild hypothermia (35-37 C) was observed following administration of FK506 or CsA. There was no significant difference in the time course of the body temperature between the FK506 and CsA group. We demonstrated that the repeated FK506 treatment, but not the CsA treatment, reduced ischemia-induced degeneration of hippocampal neurons in gerbils. Although FK506-induced hypothermia might have modified neuronal degeneration, a comparison with CsA indicated that the neuroprotective effect of FK506 was not solely due to hypothermia per se.

Animals↗
PubMed1996

Molecular cloning of novel leucine-rich repeat proteins and their expression in the developing mouse nervous system.

It is well established that leucine-rich repeat (LRR) proteins such as connectin, slit, chaoptin, and Toll have pivotal roles in neuronal development in Drosophila as cell adhesion molecules. However, to date, little information concerning mammalian LRR proteins has been reported. In the present study, we sought LRR proteins of the mouse brain, based on the assumption that fundamental mechanisms are conserved between different species. We screened a neonatal mouse brain cDNA library with a human partial cDNA encoding LRR protein as a probe. We obtained two independent cDNAs encoding LRR proteins, designated NLRR-1 and NLRR-2 (Neuronal Leucine-Rich Repeat proteins). We analyzed the whole sequence of NLRR-1 and partial sequence of NLRR-2. Sequence analysis showed that these two clones are about 60% homologous to each other, and that NLRR-1 protein is a transmembrane protein. Northern blot analysis and in situ hybridization histochemistry showed that both NLRR-1 and NLRR-2 mRNAs were expressed primarily in the central nervous system (CNS); NLRR-1 mRNA was also detected in the non-neuronal tissues such as cartilage, while NLRR-2 mRNA expression was confined to the CNS at all developmental stages. These results suggest that there is at least one LRR protein family in the mouse and that these molecules may play significant but distinct roles in neural development and in the adult nervous system.

Amino Acid Sequence↗