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Biomedical subjects

T Seki

Publications and source records attributed to T Seki.

At least 289 records · Page 16Linked to original sources
PubMed1996

Criteria for evaluating abnormal signal-averaged electrocardiogram in children classified by age, body surface area and height.

We evaluated criteria for the diagnosis of ventricular abnormal signal-averaged electrocardiogram (SAE) in 205 healthy children classified by age, body surface area and height. The children were classified by age into 4 groups: under 3 months old, 3 months old or more but less than 1 year old, 1 year old or more but less than 12 year old and 12 year old or more. They were also divided by body surface area into 4 groups: under 0.3 m2, 0.3 m2 or more but less than 0.5 m2, 0.5 m2 or more but less than 1.2 m2, and 1.2 m2 or more. In terms of height, they were classified into 4 groups: under 60 cm, 60 cm or more but less than 80 cm, 80 cm or more but less than 140 cm, and 140 cm or more. The boundary points in these 3 classifications were statistically consistent. Criteria for abnormal SAE in children classified according to age were filtered QRS duration (f-QRSd) > 95 msec, root mean square (RMS) < 30 mu v and duration of low amplitude signal (LAS) > 25 msec in those under 3 months old; f-QRSd > 110 msec, RMS < 25 mu v, LAS > 30 msec in those 3 months or more but less than 1 year old; f-QRSd > 115 msec, RMS < 20 mu v, LAS > 30 msec in those 1 year old or more but less than 12 year old; and f-QRSd > 125 msec, RMS < 20 mu v, LAS > 30 msec in those 12 year old or more. The criteria for evaluating abnormal SAE were similar regardless of whether children were classified by age, body surface area or height. Using these values as criteria, the 205 children were evaluated for the presence of abnormal SAE. All of the children were negative for abnormal SAE using these criteria according to age, body surface area or height. In evaluating abnormal SAE in children, it is useful to classify children by age, body surface area and height and to identify the criteria in each group. In this study, the criteria based on height and age were particularly useful, since these are more convenient than body surface area.

Adolescent↗
PubMed1996

Short communication: MR imaging of fetal brain abnormalities using a HASTE sequence.

HASTE (half-Fourier acquisition single-shot turbo spin echo) is a sequence that enables T2 weighted magnetic resonance (MR) images to be obtained in a few seconds. The purpose of this study was to evaluate the usefulness of this sequence in the diagnosis of fetal cerebral abnormalities. Five fetuses suspected of having cerebral abnormalities on ultrasound examination were studied by MR imaging using the HASTE sequence in utero. We compared the images with post-natal MR images or computed tomography (CT) scans. In four fetuses, the abnormality was diagnosed correctly, and the diagnosis was almost correct in the remaining fetus. This sequence is useful because it provides images of diagnostic quality in a very short scanning time.

Brain↗
PubMed1996

Purification and characterization of an intracellular alpha-D-xylosidase from Penicillium wortmannii IFO 7237.

Intracellular alpha-D-xylosidase from Penicillium wortmannii IFO 7237 was obtained by grinding the mold with almina in phosphate buffer, and the cell-free extract was purified to a homogeneous state on SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight was estimated to be 290,000 by gel filtration chromatography (Superdex 200) and 73,000 was obtained by SDS-PAGE. The purified alpha-D-xylosidase had an isoelectric point at pH 5.0. The optimum activity for the enzyme was found to be at pH 6.5 and 45 degrees C. The enzyme showed a hydrolytic activity on p-NO2-phenyl-alpha-D-xylopyranoside (alpha-p-NPX) while methyl-alpha-D-xylopyranoside (alpha-MX) was not hydrolyzed at all. It also showed lower activity for xyloglucan oligosaccharides. The apparent Km values of the enzyme for alpha-p-NPX and isoprimeverose were 1.9 mM and 50 mM, respectively.

Glucans↗
PubMed1996

[Assessment of degree of edema by means of bioelectrical impedance during pregnancy].

It is well known that the total body water in women with toxemia of pregnancy expands beyond the normally increased volume that characterizes pregnancy. Although abnormally increased water retention is usually diagnosed by both the edema of the legs and the weight gain, these methods are not quantitative. To quantify the degree of edema, we used bioelectrical impedance analysis (BIA). Because water and electrolytes are the dominant factors affecting electrical conduction in the body, the increase in total body water (the degree of edema) is assessed by BIA. BIA was conducted serially in a group of 38 normal pregnant women during pregnancy and 4 pregnant women with toxemia of pregnancy. The values for bioelectrical impedance in normal pregnant women decreased gradually during pregnancy, suggesting a physiological increase in total body water (p < 0.01). In contrast, the values for bioelectrical impedance dramatically decreased in the cases of 4 women with toxemia of pregnancy and accurately increased in the process of recovery from toxemia of pregnancy. These findings indicate that bioelectrical impedance analysis is a useful and practical method for assessing the increase in total body water.

Adult↗
PubMed1996

[A case of Jefferson fracture treated with the Sof'wire cable system method of fixation].

Jefferson fracture is a very rare disease which occurs in only 2-13% of all cervical spinal fracture cases and in only 1.3% of total spinal fracture cases. A combination of an atlas-axis fracture occurs relatively frequently and with a higher incidence of neurological morbidity than isolated fractures. However, a Jefferson fracture, which is an isolated C-1 fracture, occurs very rarely. A 58-year-old woman was involved in a traffic accident and admitted to our hospital. She had a large scalp laceration in the parietal region and complained of nuchal pain. Neurological examination revealed nothing abnormal. A cervical x-p (lateral view) revealed no abnormal findings, but an open-mouth view revealed an 8 mm displacement (in total) in the lateral mass of the atlas. A cervical CT revealed a Jefferson fracture. Crutchfield traction was performed for 9 days followed by external immobilization with a halo-vest to allow the patient to be ambulatory quickly. A posterior occipitocervical fusion was performed with an iliac bone autograft using the Sof'wire Cable system for late cervical stability and reducing the period of rigid external immobilization. The postoperative state was uneventful. The halo-vest was removed 10 weeks after surgery. An x-p obtained 3 months postoperatively showed good stability of the cervical spine. The Sof'wire Cable system proved to be very useful.

Accidents, Traffic↗
PubMed1996

[MR imaging for breast cancer].

The potential role of magnetic resonance (MR) imaging in the diagnosis of breast disease has been investigated since the late 1970s. Conventional MR imaging has not been reliable for diagnosis of breast masses, and so contrast MRI using Gd-DTPA has been performed. In particular the gradient echo (GRE) technique combined with administration Gd-DTPA (i.e., dynamic MRI) improves detection and tissue characterization of breast masses. In recent studies, breast MR imaging has shown up to 100% sensitivity in the detection of breast cancer. On the other hand, its specificity varies between 37% and 98% because of the fact that may benign lesions are also enhanced with many contrast media, similar to breast cancer. To improve the specificity of MR imaging, MR-guiding localization and fine needle aspiration biopsy for breast masses will be necessary. Recently breast conserving therapy has been widely accepted in our country, so we deduce that MRI is useful method for detecting multifocal or multicentric breast cancer.

Adult↗
PubMed1996

Production of tissue-type plasminogen activator (t-PA) and type-1 plasminogen activator inhibitor (PAI-1) in mildly cirrhotic rat liver.

We have studied the production of tissue-type plasminogen activator (t-PA) and type-1 plasminogen activator inhibitor (PAI-1) in liver of normal rats and in rats with mild cirrhosis induced by carbon tetrachloride inhalation, to demonstrate the production of these fibrinolytic components and their pathophysiologic role in the liver in vivo. Immunohistochemical study of paraffin-embedded liver sections and fibrin autography of frozen sections showed that the normal rat liver produces very little t-PA or PAI-1. On the contrary, striking t-PA activity and both t-PA and PAI-1 antigens were observed in the cirrhotic liver. Both t-PA and PAI-1 in plasma were also markedly increased in the cirrhotic rats. Because the hepatocyte can internalize t-PA or PA/PAI-1 complexes from circulation, Northern blot analysis of the total liver RNA was performed to demonstrate the endogenous synthesis of t-PA and PAI in the liver. Although the normal liver hardly expresses either t-PA or PAI-1 mRNA, striking t-PA and PAI-1 mRNA expression was observed in the liver of rats with mild cirrhosis. These data demonstrate that t-PA and PAI-1 production is strongly upregulated in the liver in rats with mild cirrhosis. These fibrinolytic components, whose production is closely associated with liver failure, may play important roles in the regulation of hepatocyte proliferation and liver regeneration in vivo.

Animals↗
PubMed1996

[Percutaneous microwave coagulation therapy for hepatocellular carcinoma--study on its therapeutic effect in surgical cases].

Six patients with hepatocellular carcinoma were subjected to percutaneous microwave coagulation therapy (PMCT) by ultrasonic guiding. The size of the main tumor in the present cases was limited to not more than 2 cm. From 18 to 48 days after PMCT, each patient was subjected to surgery and pathological examination. By macroscopic observation, the PMCT area including both non-tumor and tumor regions looked yellowish white, and the boundary was clearly recognized. In the histological examination, the coagulation area surrounded by fibrous capsule was found, and deletion of nuclei and changes in stainability were observed in the marginal region. These changes indicated obvious coagulation necrosis, but the changes became less intense toward the center in the area, and in some portions, the tissue was indistinguishable from viable cells by light microscopy. In 2 cases out of the 6, part of the tumor remained outside the coagulation area. Since only the area determined by the microwave electrode is coagulated to cause necrosis on PMCT, sufficient safety margin should be required.

Aged↗
PubMed1996

[New surgical technique of anterior decompression for cervical disc disease: vertebral column autograft with the intervertebral disc after anterior cervical decompression].

The authors describe the surgical technique of vertebral column autograft with the intervertebral disc after anterior decompression for cervical disc disease. This series consisted of 41 patients with cervical disc disease suffering from cervical spondylotic radiculomyelopathy. There were 27 men and 14 women, ranging in age from 27 to 72 years (mean age 49 years). 33 patients were operated on at one level and 8 patients at two levels. The average postoperative follow-up period was one year 10 months and ranged from 6 months to 3 years 3 months. The patients were generally allowed out of bed wearing a soft collar within 1 day postoperatively. The collar was used for 2 months after surgery. The postoperative course of all patients was uneventful and neurological symptoms improved. Postoperative X-ray films showed some movement in the operated disc level in all patients. The authors think that this surgical procedure may be suitable for preserving mobility of the spine.

Adult↗
PubMed1996

Analysis of the structure and expression of the augmenter of liver regeneration (ALR) gene.

BACKGROUND: The gene encoding the hepatotrophic factor Augmenter of Liver Regeneration (ALR) has recently been cloned in the rat. The availability of the mouse form of ALR would allow the analysis of the role of this factor in the physiology of liver and other organs, while the identification of the human homolog would allow the transfer of the great wealth of information that has been generated in animal models to clinically oriented pilot trials, and eventually the therapeutic application of this information. MATERIALS AND METHODS: Standard molecular biology approaches have been used to determine the genomic structure of the ALR gene in the mouse, and to characterize the ALR transcript and its protein product. The human ALR cDNA was also isolated and the amino acid sequence of the human gene product deduced. The mapping of mouse and human ALR genes on mouse and human chromosomes was then completed. RESULTS: The protein coding portion of the mouse ALR gene is comprised of three exons, the first containing the 5' untranslated sequence and the initial 18 bases after the ATG translation initiation codon, the second exon encompasses 198 bases, and the third exon contains the remaining portion of the protein coding sequence. Rat, mouse, and human ALR genes (and protein products) were found to be highly conserved and preferentially expressed in the testis and in the liver. The ALR gene maps to the mouse chromosome 17, in a region syntenic with human chromosome 16, where the T/t region has also been mapped. CONCLUSIONS: ALR appears to be a protein with important physiologic properties, not exclusively limited to liver regeneration, with roles that are involved in the synthesis or stability of the nuclear and mitochondrial transcripts that are present in actively regenerating cells, particularly the germ cells of the testes.

Amino Acid Sequence↗
PubMed1996

A single residue, Lys108, of the delta-opioid receptor prevents the mu-opioid-selective ligand [D-Ala2,N-MePhe4,Gly-ol5]enkephalin from binding to the delta-opioid receptor.

Previously, we found that replacement of the region around the first extracellular loop of the delta-opioid receptor (OPR) with the corresponding region of the mu-OPR gives the high affinity for [D-Ala2,N-MePhe4,Gly-ol5]enkephalin (DAMGO), a mu-opioid-selective ligand, to the resultant chimeric receptor, DMDD, suggesting that the difference in the amino acid sequence within this region between the mu- and delta-OPRs is critical for the discrimination between these receptors by DAMGO. In the current study, we carried out systematic replacements of seven non-conserved residues in this region of the delta-OPR with the corresponding amino acid found in the mu-OPR. Among the seven mutant receptors, only one mutant receptor, delta K108N, showed high affinity (Ki = 18.68 +/- 5.27 nM) for DAMGO, which was comparable to that of the DMDD receptor (Ki = 23.77 +/- 4.27 nM) and 75-fold higher than that of the wild-type delta-OPR (Ki = 1405 +/- 161 nM). Lys108 in the delta-OPR was systematically replaced with 19 kinds of amino acids other than lysine. Among the resultant mutant receptors, 14 mutants bound DAMGO with Ki values comparable to those of the DMDD receptor, ranging from 4.20 to 43.38 nM. These findings suggest that Lys108 of the delta-OPR prevents DAMGO from binding to the delta-OPR rather than that the asparagine residue at the corresponding position in the mu-OPR is necessary for DAMGO binding. In addition, the replacement of Lys108 of the delta-OPR with asparagine dramatically increased the affinity for other peptidic mu receptor-selective ligands, such as dermorphin and D-Pen-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2.

Adenylyl Cyclases↗
PubMed1996

[Effective administration of recombinant granulocyte colony-stimulating factor to prevent granulocytopenia due to combination chemotherapy for testicular germ cell tumors].

A prospective randomized study on the administration of recombinant granulocyte colony stimulating factor (rG-CSF) was conducted on 15 patients with testicular germ cell tumors. The clinical stagings of all patients except one were minimal to moderate extent according to the Indiana University staging system. Combination chemotherapy using bleomycin, etoposide and cisplatinum (BEP) was performed as the initial treatment on the eligible patients. rG-CSF was administered by two different methods; 1) routine administration on the 6th day after BEP chemotherapy (group A), and 2) the same method, but after granulocytopenia of 1,500/mm3 had developed (group B). The administration of rG-CSF in group A significantly reduced the severity of leucocytopenia and also the incidence of stomatitis compared with group B. Although rG-CSF produced no significant side effects, the thrombocytopenia was prominent in the group A patients (not significant). BEP chemotherapy itself is an easily-tolerable and well established method for treating young adult patients. The method used in group B seems to be suitable in situations where thrombocytopenia and cost effectiveness.

Adult↗