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Biomedical subjects

T Kubo

Publications and source records attributed to T Kubo.

At least 109 records · Page 6Linked to original sources
PubMed2001

Information processing of visually-induced apparent self motion in the cortex of humans: analysis with magnetoencephalography.

The cortical site which processes information on whole-body linear displacement is unknown. In this study, neuromagnetic responses to a visually-induced linear vection were recorded in 5 healthy, right-handed, adult subjects using a 122-channel whole cortex neuromagnetometer. We presented expanding rectangles on the screen which came into view one after another and accelerated in expanding speed at random cycle, giving the subjects the sensation of linear self motion (linear vection) through an illusory tunnel with occasional acceleration. Clear responses of magnetic fields related to the accelerative event were obtained in both hemispheres around the parietal and temporal regions. The dipole sources of the component were estimated in the cortex around the superior temporal sulcus, insula and medial superior temporal area. Some parts of these regions may have been comprised in the vestibular cortex, suggesting that it processes the sensation of linear self motion and plays an important role in space perception.

Adult↗
PubMed2001

Synthesis and biological properties of DNA-sugar conjugates.

In order to improve the pharmacological properties of antisense and antigene oligonucleotides, oligodeoxynucleotides conjugated with amino sugars at the 5'-terminus were synthesized by solid phase fragment condensation (SPFC) method. The obtained DNA-sugar conjugates were evaluated in their chemical and biological activities to show that 5'-end modification of oligonucleotides with sugars enhanced the thermal stability of the hybrid duplex with complementary DNA, the resistance against nuclease digestion and the membrane permeability of the conjugates.

Amino Sugars↗
PubMed2001

Synthesis and biological properties of DNA-peptide conjugates.

Some naturally occurring nuclear localizing signals (NLSs) and some artificially designed peptides were covalently conjugated by solid phase fragment condensation (SPFC) method. These DNA-peptide conjugates showed enhanced permeability into cells as well as enhanced hybrid stability with ssDNA and dsDNA, and also higher resistance against nuclease digestion.

Base Sequence↗
PubMed2001

Development of a real-time hand dose monitor for personnel in interventional radiology.

Medical procedures denoted as interventional radiology require operation near an X ray beam, which brings high dose exposures to the operators' hands. For the effectual control of their extremity doses, a prototype of a real-time wrist dosemeter has been developed, hand dose monitor (HDM), based on a single silicon detector. Experiments were performed to test its response to diagnostic X rays. The HDM was highly sensitive and showed a linear response down to doses of a few tens of microsieverts. Though dose rate, energy and angular dependence of the response were observed in some extreme conditions, the HDM was proved to be of practical use if it was appropriately calibrated. Since an HDM enables personnel to check their hand doses on a real-time basis, it would enable medical staff to control the exposure themselves.

Calibration↗
PubMed2001

Cloning of complementary deoxyribonucleic acids encoding quail (Coturnix coturnix japonica) retinoic acid receptor ss isoforms and changes in their gene expression during gonadotropic growth.

Retinoids have important effects on the development of the reproductive system, where they act via their specific nuclear receptors: retinoic acid receptors (RARalpha, ss, gamma) and retinoid X receptors (RXRalpha, ss, gamma). The research reported here was conducted in an effort to clone quail RARbeta+ cDNA (qRARbeta) and to evaluate the expression of qRARbeta+ mRNAs in different tissues and during the development of gonadotropic organs. Two complete cDNAs of qRARbeta1 and qRARbeta2 were isolated by a combination of reverse transcription-polymerase chain reaction and 5'- and 3'-rapid amplification of cDNA ends techniques. An RNase protection assay revealed the widespread expression of qRARbeta1 and beta2 with large tissue-specific variations. The qRARbeta1 isoform was predominant in the testis, whereas qRARbeta2 was dominant in the other tissues examined with the exception of the brain, where both isoforms were almost equally expressed. In the developing testes, the qRARbeta1 mRNA level was high between 30 and 40 days of age, the period during which the testes grew rapidly. The level declined thereafter to its initial level. In contrast, qRARbeta2 mRNA did not exhibit obvious changes. In the developing oviducts, both qRARbeta1 and beta2 mRNAs reached their peak levels by 30 days of age, just before the rapid development of the oviduct occurred, and then decreased to almost undetectable levels when the oviduct developed to the laying stage (over 2.88 g in weight). Similar expression patterns of qRARbeta1 and beta2 were also observed in the developing follicles from the prehierarchical (<2-mm diameter) to the largest preovulatory follicle. In contrast, neither qRARbeta1 nor beta2 mRNA exhibited developmental changes in the brain. These results suggest that RARbeta+ may play an important role in the development of the reproductive systems of birds.

Aging↗
PubMed2001

Anatomic study of the insertions of the levator aponeurosis and Müller's muscle in Oriental eyelids.

To clarify the detailed anatomy of the insertions of the levator aponeurosis and Müller's muscle, 10 upper eyelids of 5 fixed Japanese cadavers were examined. The eyelids were dissected in a manner that the authors devised to disclose the delicate pretarsal structures in close proximity. After removing the orbital roof and fat, they divided the levator aponeurosis at the origin and dissected along its posterior aspect up to the upper tarsal area. The dissected eyelids were evaluated grossly and histologically with a special staining technique. Gross and histological examinations revealed that the dense collagenous levator aponeurosis was transformed distally into fine elastic fibers, which inserted into the pretarsal orbicularis layer. They also found a distinct fascia covering the anterior aspect of the tarsus that continued proximally to Müller's muscle. Conclusively, the levator aponeurosis has no direct collagenous insertion into the tarsus, but is connected mainly to the pretarsal tissue via fine elastic fibers. A fibrous tissue covering the anterior aspect of the tarsus is not the levator aponeurosis, but an extension of Müller's muscle.

Aged↗
PubMed2001

Transclavicular approach for a large dumbbell tumor in the cervicothoracic junction.

Neurogenic dumbbell tumors occur more frequently in the cervical than in the thoracic or lumbar spine. Cervical paravertebral masses usually do not become exceptionally large because they are superficial and are palpated easily. Thoracic tumors can become large before they are detected. The authors describe a large intrathoracic dumbbell tumor arising from the C8 nerve root. The intraspinal tumor was resected through a posterior approach. In the second stage, dividing the clavicle, the intrathoracic component was resected by separating it from the lung. Two years after treatment, the preoperative neurologic deficit had improved except for weakness of muscles innervated by the C8 nerve root. Radiographs showed no residual or recurrent mass at the apex of the lung. Sometimes a retroclavicular location may conceal a large paravertebral mass, such as Pancoast tumors. As described here, the transclavicular approach gave adequate access to the cervicothoracic junction.

Cervical Vertebrae↗
PubMed2001

Osteonecrosis of the femoral head after allogeneic bone marrow transplantation.

A comparative retrospective analysis of 100 consecutive patients after bone marrow transplantation was performed with magnetic resonance imaging in addition to plain radiography for the development of osteonecrosis of the femoral head. The incidence and risk factors for osteonecrosis of the femoral head were identified, comparing various parameters concerning bone marrow transplantation between the groups with and without evidence of osteonecrosis. Nineteen (19%) of 100 patients had osteonecrosis of the femoral head develop. Four factors were found to be statistically significantly different between patients who had osteonecrosis develop and those who did not: younger age at the time of bone marrow transplantation, chronic graft-versus-host disease, cumulative dose of steroid, and intravenous pulse therapy with methylprednisolone. It was concluded that a low rate of complications and low dose steroid administration would reduce the incidence of osteonecrosis after bone marrow transplantation.

Adolescent↗
PubMed2001

Effect of acetabular cup position and orientation in cemented total hip arthroplasty.

Long-term clinical results of total hip arthroplasty for patients with developmental acetabular dysplasia of the hip have been reported, but placement of the femoral head center or cup orientation remains controversial, especially with a severe anterolateral shallow acetabulum or dislocated femoral head. Results of 41 Müller and 34 Harris Design 2 cemented total hip arthroplasties were evaluated for developmental dysplasia of the hip. The femoral head center and acetabular cup inclination angle were measured from the interteardrop line. Linear wear and wear direction were measured using the Livermore technique. The best position of the femoral head center was less than 35 mm vertically from the interteardrop line and 25 mm laterally from the teardrop. Femoral head center analysis showed that hips with the cup in a lateral and superior cup position all were revised, but a superior and medial position combined with a cup inclination angle less than 40 degrees did not require revision. Hips with a cup inclination angle more than 45 degrees had superior and lateral penetration patterns of the polyethylene. However, hips with an inclination angle less than 35 degrees and medial placement had medial head penetration patterns. With these all-polyethylene monolithic cemented cups, regardless of the femoral head diameter or cup thickness, better long-term results occurred with a cup inclination angle of 40 degrees or less and medial position of the cup.

Acetabulum↗
PubMed2001

Atrial natriuretic peptide augments the variability of sympathetic nerve activity in human heart failure.

OBJECTIVES: Activation of the sympathetic nervous system, decreased heart rate variability (HRV), and loss of modulation of muscle sympathetic nerve activity (MSNA) within the low frequency (LF, 0.05-0.15 Hz) range are three adverse features of advanced congestive heart failure (CHF). In healthy men, atrial natriuretic peptide (ANP) infusion attenuates reflex increases in MSNA and reduces LF components of HRV spectral power. Sympathoinhibitory actions have also been documented in CHF, but effects on the variability of MSNA and HRV have not been described. DESIGN AND METHODS: Heart rate and MSNA were recorded in 10 men (aged 39 +/- 3 years, mean +/- SE) with dilated cardiomyopathy (mean EF 20 +/- 4%) treated with angiotensin converting enzyme (ACE) inhibitors. Subjects received i.v. ANP (50 microg bolus then 50 ng/kg/min) and nitroglycerin (NTG, 8 mg/min) as a hemodynamic control. Signals at baseline, and 13-20 min into each infusion were submitted to spectral analysis. RESULTS: ANP had no effect on HRV, but increased MSNA LF (from 7.9 +/- 1.5 to 12.1 +/- 2.6 U2; P< 0.02) and total spectral power (from 47.9 +/- 5.4 to 61.9 +/- 6.8 U2; P < 0.05). NTG had no effect on the variability of MSNA or HRV. CONCLUSIONS: In CHF patients receiving ACE inhibitors, ANP (i) does not suppress HRV and (ii) enhances the modulation of MSNA, particularly within the LF range. This latter action is not observed with NTG. These findings suggest beneficial actions of exogenous ANP on neurogenic circulatory control.

Adult↗
PubMed2001

Rapid detection of chromosome aneuploidies by prenatal interphase FISH (fluorescence in situ hybridization) and its clinical utility in Japan.

OBJECTIVE: The purpose of this study was to assess the accuracy, informative rate, detection rate, and clinical utility of prenatal interphase fluorescence in situ hybridization (FISH) analysis of amniotic fluid samples from Japanese women. METHODS: Amniotic fluid specimens from 2,639 Japanese women were received for prenatal interphase FISH and chromosome analysis. A questionnaire was designed to evaluate FISH clinical utility by collaboration sites. RESULTS: Based on 2,319 tested samples, the accuracy (100%), informative (94%), and detection (87.6%) rates were all high. The accuracy (100%), informative (90.2%), and detection (90.0%) rates were also remarkable in third-trimester pregnancies. We perceive significant advantages from this test regarding medical management and patient satisfaction. CONCLUSIONS: This novel report shows that in Japan prenatal interphase FISH testing is highly informative and accurate, not only in second-trimester pregnancies but also in third-trimester pregnancies. This test provides advantages to both physicians and patients, provided that its capabilities and limitations are understood.

Adult↗
PubMed2001

The relation between plasma homocysteine concentration and methylenetetrahydrofolate reductase gene polymorphism in pregnant women.

OBJECTIVE: Our purpose was to clarify the influence of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism on plasma homocysteine (Hcy) concentrations during early pregnancy. METHODS: Between 1996 and 1998, Hcy concentration and MTHFR gene polymorphism were studied in 840 pregnant women between 6 to 12 weeks' gestation. Hcy concentration was measured by amino acid autoanalyzer (DLC-300, Nihon Denshi), and MTHFR genotypes were determined by the PCR/RFLP methods. Pregnancy outcomes were compared in association with Hcy concentration and MTHFR genotypes. RESULTS: A total of 816 of the 840 women were enrolled into the study because MTHFR genotypes were not available in 24 women. Genotypes of C677T in the MTHFR gene were CC: CT: TT (%) = 280 (34.3): 400 (49.0): 136 (16.7). Plasma Hcy concentration was significantly (p < 0.0001) higher in women with TT genotype than other genotypes [CC: CT: TT = 5.67 (2.8-10.6): 5.80 (2.5-20.1): 6.91 (3.5-20.9) nmol/ml, median (range)]. Women with hyperhomocysteinemia had severe preeclampsia (2 of 35 vs 5 of 714, p < 0.01) and stillbirth (2 of 35 vs 10 of 714, p < 0.05) more frequently than normohomocysteinemia. CONCLUSIONS: Plasma Hcy concentration during early pregnancy was higher in women with homozygote for the T677 allele in the MTHFR gene than other genotypes.

Adult↗
PubMed2001

Electrophysiological course of uraemic neuropathy in haemodialysis patients.

The objective of this study was to confirm electrophysiologically both the presence and course of uraemic neuropathy in haemodialysis patients. Nerve conduction studies of the lower extremities were done in 70 haemodialysis patients and 20 normal volunteers. Compared with that in normal volunteers, the distal motor latency in the tibial nerve of patients was prolonged significantly (p<0.05), and the minimal F wave latency in the tibial nerve was also prolonged significantly (p<0.05). Motor conduction velocity in the tibial nerve was reduced significantly (p<0.05), and sensory nerve conduction velocity in the medial plantar nerve also was reduced significantly (p<0.05). These results suggest the presence of uraemic neuropathy in haemodialysis patients. Twenty patients were investigated by a follow up study five years later. Parameters from F wave conduction studies, which were thought to be the most useful in the evaluation of neuropathy, showed no significant differences between the initial and follow up trials. These observations suggest that uraemic neuropathy does not progress during haemodialysis. These results also suggest that most haemodialysis patients showed electrophysiological evidence of uraemic neuropathy, but no remarkable electrophysiological change in uraemic neuropathy during haemodialysis was recognised.

Adult↗
PubMed2001

An inwardly rectifying K(+) channel, Kir4.1, expressed in astrocytes surrounds synapses and blood vessels in brain.

Glial cells express inwardly rectifying K(+) (Kir) channels, which play a critical role in the buffering of extracellular K(+). Kir4.1 is the only Kir channel so far shown to be expressed in brain glial cells. We examined the distribution of Kir4.1 in rat brain with a specific antibody. The Kir4.1 immunostaining distributed broadly but not diffusely in the brain. It was strong in some regions such as the glomerular layer of the olfactory bulb, the Bergmann glia in the cerebellum, the ependyma, and pia mater, while little activity was detected in white matter of the corpus callosum or cerebellar peduncle. In the olfactory bulb, Kir4.1 immunoreactivity was detected in a scattered manner in about one-half of the glial fibrillary acidic protein-positive astrocytes. Immunoelectron microscopic examination revealed that Kir4.1 channels were enriched on the processes of astrocytes wrapping synapses and blood vessels. These data suggest that Kir4.1 is expressed in a limited population of brain astrocytes and may play a specific role in the glial K(+)-buffering action.

Animals↗
PubMed2001

Effects of exposing the opened endolymphatic sac to large doses of steroids to treat intractable Meniere's disease.

To enhance the effect of treatment for intractable Meniere's disease, we exposed the opened endolymphatic sac to high concentrations of steroids. This technique--endolymphatic sac drainage and steroid instillation surgery--involves the application of a mass of prednisolone followed by absorbable gelatin sponges soaked in a high concentration of dexamethasone into a sac lumen opened and expanded with a bundle of absorbable gelatin film. These sponges are also placed around the sac and coated with biochemical adhesive so that the medicine is slowly delivered into the sac over a prolonged period of time by means of a natural sustained-release vehicle. The short-term results (6 to 14 months) in 12 patients with Meniere's disease, including those in stage IV, treated by the above techniques showed that definitive spells were completely controlled in all cases. Hearing was improved, and annoyance due to tinnitus was decreased in all cases except one.

Adult↗
PubMed2001

Urocortin expression in synovium of patients with rheumatoid arthritis and osteoarthritis: relation to inflammatory activity.

Peripherally produced CRH acts as a local auto/paracrine proinflammatory agent. Urocortin is a new member of the CRH family that acts through the family of CRH receptors. In this study, we demonstrated that the expression of urocortin mRNA in synovia of patients with rheumatoid arthritis was greater than that of patients with osteoarthritis. Also, we detected urocortin and CRH receptor immunoreactivity in the synovial lining cell layer, subsynovial stromal cells, blood vessel endothelial cells, and mononuclear inflammatory cells from the joints of rheumatoid arthritis and osteoarthritis patients. The expression of immunoreactive urocortin was significantly greater in rheumatoid arthritis than osteoarthritis (P < 0.0001) and correlated with the extent of inflammatory infiltrate. CRH receptor immunoreactivity was strong in mononuclear inflammatory cells of rheumatoid arthritis synovia. Urocortin stimulated IL-1beta and IL-6 secretion by human peripheral blood mononuclear cells in vitro. These findings suggest that, like CRH, urocortin is present in peripheral inflammatory sites, such as rheumatoid synovium, and acts as an immune-inflammatory mediator.

Aged↗
PubMed2001

[Improvement of method to estimate guidance by pharmacists and trial to obtain standard pharmaceutical management and guidance services program].

The level of understanding of taking medicine was examined at the start and the end of medicine-taking guidance, based on the estimation by pharmacists and inpatients. Six items for the estimation, such as "the way of taking medicines" were evaluated using a five-grade system. The significant improvement was observed in all items, suggesting that inpatients' understanding is improved by the guidance. A markedly positive correlation was found between the estimation by inpatients and that by pharmacists (p < 0.001). This confirms the appropriateness of estimation by pharmacists. Inpatients whose estimation was significantly different from that by pharmacists (difference of two grades or more) were examined to identify clear and potential problems with taking medicine. The problems were classified into such seven categories as "types of medicine". For each item with differences in estimation (two grades or more), problems were biased in some specific categories. On the basis of such a bias, a flow chart was prepared to clarify problems. In addition, a standard pharmaceutical management and guidance services program was drafted, in which measures in observation, treatment and education against problems by pharmacists were described according to the frequency of occurrence. Information about the program available on the Internet enables its use by other hospitals.

Aged↗