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Biomedical subjects

T Takeda

Publications and source records attributed to T Takeda.

At least 361 records · Page 20Linked to original sources
PubMed1997

Automatic head positioning system using PSD-equipped camera-based photostereometry and a 5-degree-of-freedom robotized chair: calibration and accuracy verification.

In measurements of jaw movements employing an X-ray television, the orientation of the patient's head must be normalized relative to the measuring device. To avoid interferring with natural jaw movements caused by using a positioning jig, we have developed an automatic head positioning system consisting of a head position sensor and a robotized chair. The position and orientation of the head is monitored by detecting the three-dimensional positions of four non-coplanar LED markers mounted on the head, by means of a set of two photoelectronic cameras. If they are incorrect, the head is moved into the required position, using a 5-degree-of-freedom robotized chair. To accomplish this accurately, the positional relations of system components must be determined precisely. This paper proposes a least-square technique of calibrating the relationship between the position sensor and the chair. Consequently, accurate positioning is achieved. Accuracy verification studies revealed that overall positioning errors lay within 2.42 mm and 1.28 degrees with respect to the position and orientation, respectively, if the markers are secured to the head support of the chair.

Biomechanical Phenomena↗
PubMed1997

[Primary tubular impairment by verocytotoxin in hemolytic uremic syndrome].

Hemolytic uremic syndrome (HUS) in childhood is recognized as the most frequent cause of acute renal failure and is greatly associated with verotoxin-producing E. coli (VTEC) infection. Most of the prodromal feature in HUS associated with VTEC infection is hemorrhagic colitis (HC). HC progresses to HUS in several days. So it is important to detect whether the patient with bloody diarrhea is associated with VTEC infection or not. From 1992 to 1996 we analyzed clinical findings of 80 HUS and 29 HC patients. High level of beta 2-microglobulin (BMG) and N-acetyl-D-beta-glucosaminidase (NAG) in the urine were observed in the early stage of the disease. We went on to examine verotoxin (VT2)-binding in mouse (ICR) renal sections by enzyme immunoassay. Specific binding of VT2 to tubules was seen in mouse kidney, and intravenous injection of VT2 to mice caused acute tubular necrosis in 15 h whereas glomeruli were intact. These data suggest that the primary target cell of VT2 was tubules in the kidney of the HUS patients with VTEC infection.

Acetylglucosaminidase↗
PubMed1997

Intratemporal facial nerve blood flow in guinea pigs.

HYPOTHESIS: To investigate the effect of interruption of the stylomastoid artery and the petrosal artery on the facial nerve blood flow with the use of a laser Doppler flowmeter. BACKGROUND: Ischemia of the facial nerve is thought to be one of the most possible causes in idiopathic facial palsy. The blood supply in the facial nerve has been studied morphologically in considerable detail; however, we have little information on its hemodynamics. METHODS: The animals used were 20 guinea pigs. The blood flow in the facial nerve at the geniculate ganglion was measured using a laser Doppler flowmeter, and the change in the facial nerve blood flow between before and after interruption of the stylomastoid artery and the petrosal artery was investigated. The interruption of both arteries was carried out by electrical cauterization with a bipolar coagulator. RESULTS: Interruption of the petrosal artery resulted in almost complete ischemia of the facial nerve at the geniculate ganglion. This decrease in the facial nerve blood flow was significant statistically (p < 0.001). But, interruption of the stylomastoid artery caused no change. CONCLUSIONS: The blood flow in the geniculate ganglion of the facial nerve is thought to come not from the stylomastoid artery but mainly from the petrosal artery. Peripheral facial palsy following ligation of the middle meningeal artery or embolization of the maxillary artery or intra-arterial infusion of anticancer drug into the maxillary artery is likely to be attributed to facial nerve ischemia at the level of the geniculate ganglion.

Animals↗
PubMed1997

Audiological findings of sensorineural deafness associated with a mutation in the mitochondrial DNA.

OBJECTIVE: The aim of this study was to investigate audiologic features and the lesion site of sensorineural deafness with mitochondrial DNA mutation at position 3243. STUDY DESIGN: Case review. SETTING: The study was conducted at the Kochi Medical School. PATIENTS: A case of sensorineural deafness in a patient who had a mitochondrial DNA mutation was presented. The incidence of deafness and diabetes mellitus (DM) was very high in the patient's family, but she did not have DM. MAIN OUTCOME MEASURES: The patient's mitochondrial DNA was examined. Furthermore, the pure-tone audiogram, the Bekesy audiogram, an auditory brain stem response, and the electrocochleogram were analyzed. RESULTS: The patient's mitochondrial DNA had a point mutation at codon 3243 (A-->G). The pure-tone audiogram showed moderate sensorineural deafness. An auditory brain stem response showed normal latencies. The electrocochleogram showed an enhanced negative summating potential. CONCLUSIONS: It was speculated that the lesion site of the auditory system was the inner ear. The possible sites in the inner ear were hair cells, the stria vascularis, and the endolymphatic sac.

Adult↗
PubMed1997

[Changes in alpha 2-adrenoceptor binding nature in guinea-pig brain following the development of morphine dependence].

We examined the effect of morphine dependence on alpha 2-adrenoceptors in guinea-pig brain. We also studied the influence of clonidine on the naloxone-induced withdrawal signs. 1. Guinea-pigs were implanted subcutaneously with MS contin (300 mg.kg-1). Two days after implantation, the binding of 3H-UK14304 (alpha 2 selective ligand) to brain membranes prepared from morphine dependent and control animals was determined. Scatchard plot of the saturation binding data revealed an increase in Bmax values and no change in the Kd values from dependent animals. These results indicate that brain alpha 2-adrenoceptors are up-regulated in morphine dependent guinea pigs. 2. Subcutaneous injection of naloxone on the 2 nd day after implantation caused characteristic withdrawal symptoms. Clonidine has been shown to reduce some opiate withdrawal signs in morphine-dependent animals.

Adrenergic alpha-Agonists↗
PubMed1997

[Changes in opioid receptor binding nature in rat brain and spinal cord following formalin or carrageenan-induced nociception].

Previous reports demonstrated the regulation of opioid and their receptor in nociception, but it is not clear how nociceptive activation may alter opioid receptor binding nature. We determined the change of mu, delta and kappa opioid receptor types in brain and spinal cord homogenates obtained from animal models receiving nociceptive treatment. 1) Rats received a subcutaneous injection of formalin and carrageenan into planter aspect of a hindpaw. These agent-injected animals were observed for appearance of pain-related behavior (guarding of the treated paw) within 2-3 hour after treatment. Following these pain behavior, rats were decapitated and brain and spinal cord were removed rapidly. 2) The binding of 3H-DAGO (mu agonist), 3H-DPDPE (delta agonist) and 3H-EKC (kappa agonist) to brain and spinal cord membranes prepared from nociceptive treatment and control rats was determined. Using these tracer 3H-opioid ligands, we failed to see any change in the total number of opioid binding sites (Bmax values) or the affinity constant (Kd values) for binding in whole brain and spinal cord. These results indicate that in these animal models which use experimentally induced inflammation to stimulate a condition of nociception, there appears to be no alteration in the levels of mu, delta or kappa binding sites.

Animals↗
PubMed1997

Computed radiographic measurement of the dimensions of the vestibular aqueduct in Menière's disease.

Lateral polytomography of the vestibular aqueduct by computed radiography was carried out in 30 normal subjects and 25 patients with Meniere's disease, 14 of whom had bilateral involvement. The vestibular aqueduct could be identified clearly not only in normal subjects but also in patients with Menière's disease. Normal vestibular aqueducts were funnel-shaped or tubular, and the width of the external aperture was 6.0 mm on average. In contrast, a hypoplastic vestibular aqueduct with a narrow external aperture was often observed in patients with Menière's disease. Especially, in affected ears of patients with unilateral Menière's disease, the external aperture was very narrow; its mean width was 2.2 mm. In these cases, the most common radiographic configuration of the vestibular aqueduct was filiform. Meanwhile bilateral Menière's disease had a relatively wide external aperture compared with that of unilateral Menière's disease, although a hypoplastic vestibular aqueduct was also observed in patients with bilateral Menière's disease. As to the distribution of radiographic configuration types, bilateral Menière's disease had almost the same distribution as in normal ears. From these results, it was concluded that a hypoplastic development of the vestibular aqueduct was based on the etiology of Menière's disease, but general factors as well as a hypoplastic vestibular aqueduct seem to be responsible for bilateral involvement.

Constriction, Pathologic↗
PubMed1997

Antidiuretic hormone and psychosomatic aspects in Menière's disease.

We studied the relation between psychosomatic profiles of patients with Menière's disease and antidiuretic hormone (ADH). For investigation of the psychosomatic aspects, we used the Cornell Medical Index (CMI), Yatabe-Guilford personality (Y-G) test and the originally produced stress questionnaire. In Y-G test, patients with Menière's disease are classified in normal group. In the CMI test, on the other hand, types III and IV were significantly more often observed in Menière's disease than normal control (chi 2 test, p < 0.05). However, the CMI test results have no correlation to plasma ADH (p-ADH) levels. The survey of our original questionnaire revealed that stress has a close relationship to vertiginous attacks. Further, high p-ADH levels were significantly frequently observed in cases with stress compared with cases without stress (t-test, p < 0.05).

Adult↗
PubMed1997

Amyloid A protein amyloidosis induced in apolipoprotein-E-deficient mice.

Apolipoprotein E (apoE) is a constituent of lipoproteins other than low-density lipoprotein, and it principally acts in the transport and metabolism of plasma cholesterol and triglyceride. ApoE is a minor constituent of various kinds of amyloidoses and may play a role as a pathological chaperone for fibrillogenesis of amyloid fibril protein with the amyloid P component and proteoglycans. In this study, we examined the role of apoE in amyloidogenesis in vivo in apoE-deficient mutant mice with amyloid A protein (AA) amyloidosis induced by inflammatory stimulation. Amyloid deposition was seen in six of nine C57BL/6J control mice and in six of eight apoE-deficient mutant mice after the intraperitoneal and subcutaneous injections of the mixture of complete Freund's adjuvant and Mycobacterium butyricum. Moreover, amyloid deposition in apoE-deficient mice as well as C57BL/6J control mice started 48 or 72 hours after injection of amyloid-enhancing factor and silver nitrate, although the amount of amyloid deposit in C57BL/6J control mice was slightly larger than that in apoE-deficient mice. These amyloid deposits reacted with anti-mouse AA antibody were seen in the perifollicular area of the spleen. Immunoreactivity of apoE was seen irregularly in the amyloid deposits of C57BL/6J control mice but not in the amyloid deposit of apoE-deficient mice. From these results, we concluded that apoE is not always necessary for amyloid deposition and that the existence of apoE might slightly accelerate AA amyloid deposition in the earliest phase of AA amyloid deposition.

Amyloidosis↗
PubMed1997

Effect of histamine on human fibroblast in vitro.

The effects of histamine (CAS 51-45-6) on cell growth, collagen synthesis of fibroblasts derived from human foreskin, and on fibroblast-mediated collagen remodelling were studied. The cellmat DNA content was measured 2 days after human fibroblasts were plated at a split ratio of 1:10. Effect of histamine (10(-9)-10(-4) mol/l) on the increase of DNA content was not observed. Fibroblasts at confluence were cultured with histamine only, and with pyrilamine or cimetidine in addition to histamine for 2 h. Type I procollagen C-peptide in the medium was measured by enzyme immunoassay and was corrected by DNA content. Type I collagen synthesis was stimulated by histamine (10(-6)-10(-4) mol/l) and its stimulation was inhibited by cimetidine, but not by pyrilamine. Collagen solution containing fibroblast was incubated until gelation. It was incubated with histamine only, and with pyrilamine or cimetidine in addition to histamine. The gel contraction was stimulated by histamine (10(-4) mol/l) and its stimulation was inhibited by pyrilamine, but not by cimetidine. These facts suggests that histamine stimulates type I collagen synthesis of fibroblast and collagen remodeling via H2 and H1 receptors, respectively.

Cell Division↗
PubMed1997

[Transarterial immuno-embolization therapy in patients with hepatocellular carcinoma].

Surgical resection, transcatheter arterial embolization (TAE) and percutaneous ethanol injection therapy (PEIT) are effective for hepatocellular carcinoma (HCC), but the recurrence rate is high. We have devised a new therapy of transarterial immuno-embolization (TIE) with OK-432, fibrinogen and thrombin, and 2 cases are reported. Case 1: A 78-year-old Japanese male with HCC (diameter, 4 cm in subsegment 5) received TIE. The tumor size was markedly decreased, and the patient survived for more than 3 years without recurrence. Case 2: A 61-year-old Japanese male with HCC (diameter, 4.5 cm in segment 5) received hepatic subsegmentectomy following TIE. Histological examination of resected specimens following TIE showed massive infiltration of mononuclear cells in the main tumor. Tumor recurrence had developed three times thereafter, but was effectively treated by TIE. TIE may be an effective therapy for HCC.

Aged↗
PubMed1997

Identification of genes specifically expressed in chronic and progressive glomerulosclerosis.

To identify genes expressed predominantly in the kidney with chronic and progressive glomerulosclerosis but not in acute and transient form of glomerulonephritis, we induced progressive glomerulosclerosis in rats by applying unilateral nephrectomy prior to injection of monoclonal anti-Thy1.1 antibody (OX-7), which cause acute and transient glomerulonephritis with single injection. In rats with nephrectomy and OX-7 injection (Nx group), proteinuria increased with time and mesangial expansion accompanied with interstitial fibrosis was recognized, whereas transient proteinuria and mesangiolysis followed by mesangial hypercellularity were seen in rats with sham operation and OX-7 injection (Sham group). Four weeks after the induction of glomerulonephritis, mRNAs were isolated from kidney cortex of both groups and used for cDNA synthesis. By subtraction hybridization of cDNAs from Nx with excess amount of those from Sham, we isolated and sequenced several genes expressed specifically in the Nx group. These included genes, which contain identical sequences with serine protease inhibitors, cytokine receptors, osteopontin as well as genes with unknown function. These genes may play important roles in the process which promotes acute glomerular damage advance to chronic and progressive glomerulosclerosis.

Animals↗
PubMed1997

Positional reproducibility of the patient's head normalized by a robotized chair-based automatic head-positioning system, Racs-N.

With a view to normalization of the head orientation without the use of a fixation jig for the measurement of jaw movement employing an X-ray television, we have been developing an automatic head-positioning system, Racs-N, consisting of a head-position sensor and a robotized chair. The head position is monitored in 6 degrees of freedom (d.o.f.) by using a position-sensitive detector (PSD) camera-based photostereometry. If they are incorrect, the robotized chair rectifies them automatically by adjusting the position and orientation of the head support in 5 d.o.f. (except the vertical position). The rectified position, however, has a certain margin of error, due to the mobility of the head relative to the head support. To improve this, we employed an iterative correction in that the positioning is repeated until the determined position converges. In experiments employing several subjects, this particular correction was verified to converge by more than six iterations and to be effective for the reduction of head-position errors.

Adult↗
PubMed1997

[An autopsy case of Goodpasture syndrome preceded with membranous glomerulonephritis].

Goodpasture syndrome (GS) is an autoimmune disorder characterized by the association of pulmonary hemorrhage and rapidly progressive glomerulonephritis. The pathogenesis of GS is still unknown, but was shown to be the result that antibodies directed against glomerular basement membrane (GBM) antigens could injure both glomerular and pulmonary alveolar basement membrane. And membranous glomerulonephritis (MGN) is a glomerular disease characterized by epimembranous immune deposits and basement membrane thickening. MGN typically presents with the onset of nephrotic syndrome, but it often presents with only asymptomatic proteinuria. We reported an autopsy case of GS preceded with MGN. A 70-year-old man was admitted to our hospital with acute renal failure in May 2, 1996. Percutaneous renal biopsy demonstrated a crescentic glomerulonephritis associated with MGN and linear immunofluorescent staining of the basement membrane with antibodies to IgG. Two weeks later on admission he began to develop slight hemoptysis and chest X-ray showed pulmonary hemorrhage, Furthermore, his serum anti-GBM antibodies titer was very high. He was diagnosed as GS associated with MGN and treated with plasma exchange, glucocorticoid, and cyclophosphamide. Though his symptom was improved for intensive support, he suddenly died on June 22. Autopsied lungs showed focal pulmonary hemorrhage, but were not considered to be life-threatening. The cause of the death remained unclear.

Aged↗
PubMed1997

[An adult case of Williams-Campbell syndrome associated with pulmonary hypertension and a severe decrease in ventilatory response].

Williams-Campbell syndrome is a unique form of bronchiectasis caused by a congenital defect in bronchial cartilage, and is rare in Japan. A 34-year-old man was admitted to our hospital with a fever, and a productive cough. Arterial blood gas analysis revealed severe type II-respiratory failure. Many thin-walled cystic shadows (5-60 mm in diameter) were present in the entire lung field. Pulmonary function tests revealed obstructive impairment. Bronchograms demonstrated cystic bronchiectasis, with ballooning on inspiration and collapse on expiration, characteristic of Williams-Campbell syndrome. Despite severe hypoxia, he did not suffer from dyspnea. We examined ventilatory response to hypercapnea (HCVR) and hypoxia (HVR), and both HCVR and HVR were abnormal. In addition, the mean pulmonary artery pressure was 26 mmHg, indicating pulmonary hypertension.

Adult↗
PubMed1997

Immunolocalization of proliferating cell nuclear antigen in the peri-implant epithelium.

The aim of the present study was to investigate the proliferating activity of peri-implant epithelium immunohistochemically using proliferating cell nuclear antigen (PCNA). Eight ITI (Internationale Team für Implantologie) implants were placed into simulated sockets in the mandibles of two beagle dogs two months following tooth extraction. As a control, junctional epithelium of the molar teeth in the same animals were used. The nature of staining and the distribution of PCNA immunoreactivity were determined by scoring a minimum of 100 cells on two sections from each of the implants. In the junctional epithelium, the immunoreactivity to PCNA was detected mainly in the basal cells, in some of the prickle cells, and in a few cells attached to the enamel. In peri-implant epithelium, only some of the basal cells were positive for PCNA. The PCNA score of the peri-implant epithelium was significantly lower than that of junctional epithelium. These results suggest that the peri-implant epithelium maintains a lower capacity to act as a proliferative defence mechanism than does the junctional epithelium.

Animals↗