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Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 199 records · Page 11Linked to original sources
PubMed1995

Functional localization of bilateral auditory cortices using an MRI-linked whole head magnetoencephalography (MEG) system.

In 20 healthy subjects, auditory evoked magnetic fields were measured over the entire head, using a helmet-shaped 66-channel MEG system linked to MRI. When the left or right ear was stimulated by 60 msec 2 kHz tones, the prominent 100 msec response (N100m) appeared significantly earlier in the contralateral hemisphere than in the ipsilateral one. In 16 cases, the N100m dipolar field patterns were clear in both hemispheres, overlapping each other across the midline. The N100m sources were estimated using a 2-dipole model in a spherical conducting medium with the size and location of the sphere determined individually according to the MRI images. No differences were found between the contralateral and ipsilateral N100m dipole positions in one hemisphere. When superimposed on MRI, the N100m dipoles were located precisely on the upper surface of bilateral temporal lobes with a standard deviation of 2.2 mm in the superior-inferior direction. In 16 right handed males, the right hemispheric N100m dipoles were 6 mm anterior to the left hemispheric dipoles. The whole head MEG is suitable to see small but significant differences of bilateral cerebral function, with exceptionally high spatial resolution, confirmed by the MRI-linked system.

Adult↗
PubMed1995

The efficacy of kinesthetic reading treatment for pure alexia.

This paper presents an effective treatment for pure alexia by a type of single-case design, which we termed a "material-control single-case design" [Sugishita et al., Neuropsychologia, Vol. 31, 559-569, 1993]. Two patients with pure alexia were treated using kinesthetic reading (reading by tracing or copying the outline of each letter with the patient's finger). The results clearly demonstrated that both patients significantly improved their reading and copying performances. Their recovery of reading performance arose from improvement in copying. The results of tachistoscopic reading tests suggested that the patient obtained the ability to read without kinesthetic movements.

Adult↗
PubMed1995

Differentiation and proliferative activity in benign and malignant cartilage tumors of bone.

To assess the histological grade in benign and malignant cartilage tumors of bone by more objective methods, we examined the differentiation and proliferative activity of tumor cells in six enchondromas, five chondroblastomas, and 13 chondrosarcomas immunohistochemically. A variable number of cells in all tumors showed S-100 protein and vimentin immunoreactivity. In fully differentiated cartilage of enchondromas and low grade chondrosarcomas, tenascin, which is an extracellular matrix glycoprotein, was present in small amounts or absent but was increased at the periphery of tumor lobules and even in the matrix throughout the high grade chondrosarcomas. Higher rate and intensity of proliferating cell nuclear antigen (PCNA) reactivity were found in chondrosarcomas, especially in spindle-shaped cells of high grade tumors, than in enchondromas. The distribution of PCNA-positive cells almost corresponded to the regions with tenascin reactivity. One tumor of high grade chondrosarcoma showed p53 protein immunoreactivity. Aberrant expression of cytokeratin was observed in four chondroblastomas. The expression of desmin was identified in relatively large proportions of enchondromas and chondrosarcomas, regardless of their benign or malignant nature and histological grade. Smooth muscle or muscle-specific actins also were present in a smaller number of tumors. Based on these findings, it is concluded that unusual staining characteristics were present, in addition to those of a chondroblastic nature, in the cartilage tumors of bone. Tenascin and PCNA positivity of various degrees in all chondroblastomas may suggest that they are chondrogenic tumors having a relatively high proliferative activity, albeit their benign clinical course. Proliferative activity of tumor cells in enchondromas and chondrosarcomas correlated well with their histological grade. Tenascin may play a role in promoting tumor cell proliferation of cartilagenous neoplasms and, on the other hand, the alterations of extracellular matrix involving tenascin synthesis seem to be a result of tumor development.

Adolescent↗
PubMed1995

Phosphorylation of MARCKS, neuromodulin, and neurogranin by protein kinase C exhibits differential responses to diacylglycerols.

Diacylglycerols (DG) derived from brain phosphatidylinositol (PI) and phosphatidylcholine (PC) and synthetic 1,2-dioleoylglycerol (diC18:1) and 1,2-dioctanoylglycerol (diC8) were tested for their efficacy in stimulating PKC-catalyzed phosphorylation of three physiological substrates in the brain, namely, MARCKS, neuromodulin (Nm), and neurogranin (Ng). The A0.5 of these DGs for PKC were variable dependent on the protein substrates; the values were lowest with MARCKS and highest with Ng. With Ng as a substrate the A0.5 of these DGs for PKC gamma were PI- and PC-DGs < diC18:1 < diC8. Both PI- and PC-DGs, in spite of their differences in unsaturated fatty acids content, were similarly effective in stimulating PKC. Since the phosphorylation of MARCKS, as compared to those of Nm and Ng, has the lowest A0.5 with the various DGs, it seems that among these three PKC substrates MARCKS is most readily phosphorylated by PKCs following DG formation in vivo.

Animals↗
PubMed1995

Genetic association of the very low density lipoprotein (VLDL) receptor gene with sporadic Alzheimer's disease.

A specific isoform of apolipoprotein E has been associated with the accelerated rate of disease expression of sporadic Alzheimer's disease (AD) and late-onset familial AD (FAD). An earlier age at onset has also been demonstrated in familial AD patients with mutations in the amyloid precursor protein (APP) gene (APP717 and APP670/671)13 carrying the APOE epsilon-4 allele compared to those who do not, but not in familial AD patients with APP692 or 693 mutations, or in chromosome 14-linked familial AD patients. Hypothesizing that receptors for apoE-containing lipoproteins act as a potential risk factor for AD, we performed an association study using a polymorphic triplet (CGG) repeat in the gene for the VLDL receptor (VLDL-R), a receptor for apoE-containing lipoproteins. The frequency of the 5-repeat allele was significantly higher in all of the Japanese sporadic AD patients (P < 0.02) than in the Japanese controls. Moreover, the odds ratio was significantly increased in the AD patients homozygous for the 5-repeat allele (OR = 2.1, 95% CI = [1.1-4.2]). Multiple logistic regression analysis reveals that the relative risk conferred by the presence of two copies of the 5-repeat allele and at least one copy of the APOE epsilon-4 allele is 8.7 (95% CI = [2.9-25.8]). Our results suggest that the VLDL-R gene is a susceptibility gene for AD.

Alleles↗
PubMed1995

Aneurysmal fibrous histiocytoma of the skin. A histological, immunohistochemical, and ultrastructural study.

We present two cases of aneurysmal fibrous histiocytoma of the skin on the lower extremities of a 41-year-old man and a 23-year-old woman. Both the tumors appeared clinically as cutaneous nodules with a recent history of rapid growth and showed microscopically a unique formation of blood-filled tissue spaces and a storiform proliferation of histiocyte-like and fibroblast-like cells in a capillary-rich stroma. Such clinical and histologic features fit the original description of this entity. Immunohistochemically the tumor cells of both cases were immunoreactive for factor XIIIa, Mac 387, and vimentin and gave negative results for factor VIII-related antigen, desmin, actin, and S-100 protein. Ultrastructurally the tumors were composed mainly of siderosome-containing histiocyte-like cells, fibroblast-like cells, and intermediate cells and lacked prominent proliferation of endothelial cells. Thus, the ultrastructural findings agreed with the immunophenotypes expressed by the tumor cells, supporting the fibrohistiocytic origin of this lesion. In view of the recent rapid growth, the presence of hemorrhagic pseudocysts, the extravasation of erythrocytes, and the high vascularity of the present tumors, we emphasize the importance of distinguishing this lesion from angiomatoid fibrous histiocytoma and cutaneous malignancies of mesenchymal origin.

Actins↗
PubMed1995

Leser-Trélat sign associated with Sézary syndrome.

A 74-year-old Japanese male had developed generalized erythroderma and rapid growth of multiple verrucous lesions over the entire surface of his face, trunk, and extremities three months before he was seen. Histologically seborrheic keratoses were revealed. Laboratory examinations showed peripheral leukocytosis with atypical lymphocytes and high levels of IgE and IgG. On the basis of these clinical and histopathologic findings, we diagnosed the patient as having Leser-Trélat sign associated with Sézary syndrome. The erythroderma subsided after administration of oral predonisone, and no new formations of seborrheic keratosis were observed. However, because of subsequent aggravation of the generalized erythroderma, we administered chemotherapy. Six months after the initial examination, lung cancer was found, and the patient subsequently died of respiratory and renal failure.

Aged↗
PubMed1995

Conspicuous growth of intravenously inoculated Staphylococcus aureus in subcutaneously established Ehrlich ascites tumor tissue of mice.

Intratumoral growth of Staphylococcus aureus was compared with the intrarenal growth, to examine the usefulness of the method as a marker of its pathogenicity. When 5 x 10(7) CFU/mouse of three derivatives from S. aureus Cowan I with different intrarenal growth were intravenously injected into Ehrlich tumor-bearing mice, they lodged in the tumor tissue at approximately 10(3) CFU/0.1 g by 30 min after infection, and grew in the range of 10(6) CFU/0.1 g to 10(8) CFU/0.1 g by day 4, regardless of their intrarenal growth capacity. In contrast, S. saprophyticus lodged in both tissues to the same degree as S. aureus, but did not grow at all. The time course of the staphylococcal growth was different between tumor tissue and kidney, suggesting differences in the local responses against S. aureus.

Animals↗
PubMed1995

Auxiliary method for clonal identification of Staphylococcus aureus by protein band pattern of released proteins on SDS-polyacrylamide gel.

A supportive method for clonal identification of Staphylococcus aureus strains was devised. Culture supernatant obtained by cellophane surface culture was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) without performing any concentration procedure prior to electrophoresis. The combined use of cellophane surface culture and SDS-PAGE was convenient for determining whether the strains belonged to the same clone or not when conducted in conjunction with other tests for bacteriological characterization.

Bacterial Proteins↗
PubMed1995

Subcutaneous growth of Staphylococcus aureus concomitantly inoculated with Ehrlich ascites tumor cells.

Intratumoral growth of Staphylococcus aureus Cowan I-derived AP332 was examined by subcutaneous inoculation of cocci in doses ranging from 18 to 1.8 x 10(5) CFU with Ehrlich ascites tumor cells. Inoculation of 18 CFU AP332 resulted in staphylococcal growth in one of five mice, and the proportion of mice established intratumoral infection increased with the initial inocula. Six other strains of S. aureus also grew in the tumor tissue, and none of the three strains of coagulase-negative staphylococci grew at all. Ethanol-killed tumor cells did not promote staphylococcal growth as vigorously as the live tumor cells, especially when the initial inoculum of AP332 was smaller than 10(4) CFU.

Abscess↗
PubMed1995

Gene expressions of oxytocin and oxytocin receptor in cumulus cells of human ovary.

Oxytocin (OT) has been detected in mammalian granulosa-luteal cells during the early stages. The purpose of this study was to explore gene expressions of OT and OT receptor (OTR) in human cumulus cells. Cumulus cells enclosing a mature oocyte were obtained from 6 women undergoing clinical in vitro fertilization and embryo transfer programs. OT and OTR gene expressions were investigated by employing reverse transcription polymerase chain reaction and reverse transcription polymerase chain reaction/single-strand conformation polymorphism methods. OT gene expression in the cumulus cells was positive in 5 women and weakly positive in the remaining patient. The structure of OT mRNA in the cumulus cells was equivalent to that in human hypothalamus. OTR gene expression was also observed in the cumulus cells. This study is the first to describe the simultaneous expression of both OT and OTR genes in human cumulus cells. It is suggested that local OT plays some important roles in fertility through modification of the micro-environment around the oocyte.

Base Sequence↗
PubMed1995

Effects of a dopamine antagonist (metoclopramide) on the release of beta-endorphin, ACTH and cortisol in hyperprolactinemic-amenorrheic women.

Responses of LH, TSH, PRL, beta-endorphin-like immunoreactivity, ACTH and cortisol to metoclopramide were evaluated in hyperprolactinemic-amenorrheic women and normal women. Augmented TSH responses and blunted PRL responses to metoclopramide were found in hyperprolactinemic women compared to normal women. A significant increase in serum LH levels was found only in hyperprolactinemic women after metoclopramide. Thus, the hyperprolactinemic women showed hormonal changes compatible with increased central dopaminergic tone. A significant increase in circulating levels of beta-endorphin-like immunoreactivity, ACTH and cortisol was found in hyperprolactinemic women but not in normal women after metoclopramide administration. Thus, beta-endorphin and ACTH secretion appear to be tonically inhibited by increased central dopaminergic tone in hyperprolactinemic-amenorrheic women.

Adrenocorticotropic Hormone↗
PubMed1995

Measurement of urinary free beta-human chorionic gonadotropin by immunoradiometric assay.

An immunoradiometric assay for free beta-human chorionic gonadotropin (F beta hCG) is now available. Measurement of serum F beta hCG has been shown to be valuable for the diagnosis of trophoblastic disease and for screening Down's syndrome pregnancies. Urine specimens may be preferable to blood samples since collection of urine specimens usually are less inconvenient to patients than venipuncture. We have evaluated whether the immunoradiometric assay can be applicable to urine samples. The assay was sensitive and precise. When urine samples were diluted 4-fold or more, the diluted samples gave quantitative values, and recovery of beta hCG added to urine samples was satisfactory. Creatinine corrected urinary F beta hCG levels correlated with serum F beta hCG levels. Thus, the immunoradiometric assay was considered to be applicable to urine samples. Serum F beta hCG to hCG ratio has been reported to be important to distinguish among normal pregnancies, hydatidiform mole and choriocarcinoma. However, urinary F beta hCG to hCG ratio did not significantly correlate with serum F beta hCG to hCG ratio. And therefore, the clinical value of urinary F beta hCG to hCG ratio should be further investigated.

Chorionic Gonadotropin↗
PubMed1995

[The effects of long-term intake of restricted calcium, vitamin D, and vitamin E and cadmium-added diets on various organs and bones of mice: a histological and the roentgenological study].

The toxic effects of long-term administration of cadmium (Cd) on the kidneys, liver, and hind leg bones were studied histologically and roentgenologically in 29-day-old female ICR-strain mice separated into groups variously fed 1) a commercial (calcium [1.17%], vitamin D [220IU/100g], vitamin E [10mg/100g]) diet, 2) a low Ca (0.18% diet, 3) a low Ca and low D (50IU/100g) diet, and 4) a low Ca, low D and low E (5mg/100g) diet. Though the levels of vitamin D and vitamin E were designed to be low in each diet, their amounts fulfilled the nutritional requirements. Three subgroups in each category were fed Cd at dietary concentrations of 0, 20 or 40 ppm. After 12, 18 or 24 months on these diets the mice were sacrificed. 1) In the groups fed the commercial diet containing Cd, prominent swelling of the glomerulus and thickening of the basement membrane of glomerulus were observed. This did not occur in the groups fed the commercial diet without Cd. 2) In the groups fed the Cd-added low-Ca diet the following findings were more prominent compared with the low-Ca diet group. In the kidneys, swelling of the glomerulus, hyaline casts in tubular lumina and cellular infiltration of the interstitial tissue were present. In the liver, cellular infiltration on the interstitial tissue were present. In the liver, cellular infiltration of the interstitial tissue occurred. In the hind leg bones, thinning of trabeculae and ossification of the Achilles's tendon were seen. 3) In the Cd-added low-Ca, D diet groups, there was atrophy of glomerulus, thickening of basement membrane of glomerulus, and atrophy of tubular epithelial cells in the kidneys, while in the liver, binuclate cells, anisonucleosis and enlargement of Kupffer cells were seen. In the hind leg bones, thinning of the cortex and trabeculae were present. All of these findings were more prominent in this group than in the low-Ca, group. 4) In the Cd-added low-Ca, D, E, diet groups subjects the following findings were more prominent than in the low-Ca, D, E, diet group. In the kidneys, there was swelling of glomerulus and in the liver, there were binuclate cells, anisonucleosis, and cellular infiltration into interstitial tissue. In the hind leg bones, thinning of the cortex and trabeculae, a decrease of cartilage cells and a decrease of osteocytes were seen. These histological and roentgenological changes were seen to increase in a dose-dependent manner with the amount of dietary Cd.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

Cloning and nucleotide sequence of the inulin fructotransferase (DFA I-producing) gene of Arthrobacter globiformis S14-3.

A gene encoding an inulin fructotransferase (DFA I-producing) [EC 2.4.1.200] from Arthrobacter globiformis S14-3 was cloned and the nucleotides sequenced, for the first time. The sequence indicated that the native enzyme protein is composed of 392 amino acid residues. The native enzyme is an extracellar enzyme produced in the culture supernatant of A. globiformis S14-3, but the nucleotide sequence of the gene lacks a sequence for signal peptide for secretion. The 1.5-kb DNA fragment encoding the gene was found to produce the active enzyme in the culture supernatant of an E. coli clone, under the control of the lac promoter of pUC119.

Amino Acid Sequence↗
PubMed1995

Dysgerminoma of the ovary with hypercalcemia associated with elevated parathyroid hormone-related protein.

The purpose of the present paper is to present a rare case of dysgerminoma of the ovary with hypercalcemia showing elevation of multiple serum tumor markers including parathyroid hormone-related protein (PTH-rP). An 18-year-old unmarried woman, with ovarian dysgerminoma showing hypercalcemia and elevated serum PTH-rP, received six courses of a combination chemotherapy consisting of bleomycin, etoposide and cisplatin after her first surgery, and had no evidence of recurrence approximately 30 months after completing the chemotherapy.

Adolescent↗
PubMed1995

[Evaluation on the perioperative left ventricular function of aortic valve replacement in patients with chronic aortic regurgitation].

To evaluate the perioperative left ventricular function in 36 patients undergoing aortic valve replacement (AVR) in patients with isolated chronic aortic regurgitation (AR), hemodynamic variables before and within the first 24 hours and one month after operation were measured with Swan-Ganz catheter and echocardiography. The patients were divided into two groups based on preoperative left ventricular end-systolic volume index (LVESVI): 5 patients had a LVESVI of 90 ml/m2 and greater (group I), 31 had a LVESVI smaller than 90 ml/m2 (group II). Left ventricular dimension at end-diastole and end-systole, left ventricular end-diastolic volume index at one month after operation significantly decreased in comparison with that of preoperation. However, left ventricular ejection fraction in the two groups were not improved, and left ventricular mass index in group I did not decreased. On the other hand, changes of cardiac index, stroke volume index and left ventricular stroke work index within the first 24 hours after operation were not significantly different between the two groups. The incidence of postoperative premature ventricular contraction in group I was significantly higher than that of group II. However, there was no difficult problems in postoperative management of the two groups. It is suggested that AVR in AR with left ventricular dysfunction can safely be operated and its postoperative management is similar to AVR in AR with no left ventricular dysfunction.

Adult↗