Search PubMed⌕ Search

Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 145 records · Page 8Linked to original sources
PubMed1997

Disappearance of unilateral spatial neglect following a simple instruction.

OBJECTIVES: To clarify the reason why patients with left unilateral spatial neglect fail to copy the left side of a daisy like flower, not continuing to draw petals all around. METHODS: A flower was simplified and a figure was made that consisted of a large central circle and small circles surrounding it. Four patients with typical left unilateral spatial neglect performed copying and arrangement tasks to make this figure. In the arrangement task, they were instructed to arrange small circles all around the printed central circle. RESULTS: The patients' identification of the composition seemed flawless. In the copying task, they showed neglect, leaving a space on the left side. They seemed to adhere to their plan to place the same number of small circles as those of the model figure. By contrast, neglect disappeared in the arrangement task. CONCLUSION: Patients with neglect can draw the figure satisfactorily if they use a spatial strategy to arrange small circles all around. This strategy seems to improve motivation for drawing and awareness for the left space. It is considered that in the copying of figures such as a daisy, failure to use a spatial strategy plays an important part in the appearance of left unilateral spatial neglect.

Aged↗
PubMed1997

Parathyroid-hormone-related protein in human milk and its relation to milk calcium.

Parathyroid-hormone-related protein (PTHrP) is found in high concentrations in human milk. One of the possible physiological roles of PTHrP may be the regulation of calcium transport through the mammary gland. The relationship between milk PTHrP and Ca concentrations was evaluated in lactating women in the present study. Milk PTHrP has been quantified by immunoradiometric assay (IRMA) and radioimmunoassay (RIA). The IRMA detects PTHrP 1-72, and the RIA carboxyterminal region of PTHrP (C-PTHrP). Milk PTHrP 1-72 and C-PTHrP concentrations did not significantly change by breast-feeding. Milk PTHrP 1-72 changed significantly by the time of day, in contrast to C-PTHrP. Thus, PTHrP 1-72 rather than C-PTHrP may reflect an acute change in mammary PTHrP secretion. In lactating women in whom milk PTHrP and calcium concentrations were serially measured at 5-day intervals up to 26-30 days after delivery, milk PTHrP 1-72 progressively increased with duration of lactation. In contrast to PTHrP 1-72, milk C-PTHrP decreased during this period. And milk PTHrP 1-72 levels inversely correlated with C-PTHrP levels. Milk C-PTHrP but not PTHrP 1-72 levels correlated significantly with milk Ca concentrations. Although it is not certain whether the correlation between milk C-PTHrP and Ca levels is causally related, it may be that fragments of PTHrP detected as C-PTHrP are involved in the regulation of Ca transport through the mammary gland in women.

Calcium↗
PubMed1997

The beta APP717 Alzheimer mutation increases the percentage of plasma amyloid-beta protein ending at A beta42(43).

We measured plasma levels of amyloid beta protein (A beta) ending at positions 40 (A beta40) and 42(43) [A beta42(43)] in six carriers of beta APP717 (Val to Ile) mutation linked to familial Alzheimer's disease (FAD) as well as in patients with sporadic AD (sAD) and controls. The percentage and the level of A beta42(43) were significantly higher in carriers of beta APP717 mutation relative to sAD, whereas A beta40 levels were decreased. In contrast, A beta levels and ratios were at similar levels in sAD, regardless of the stage of the disease, compared with non-AD neurologic disease controls and nondemented control individuals. These results suggest that the reported increase in the percentage of A beta42(43) secretion in transfected cells with beta APP717 mutant genes actually takes place in the bodies of carriers of beta APP717 mutation, and that plasma A beta could be used as an indicator of the alterations of beta APP/A beta metabolism in subtypes of AD.

Adult↗
PubMed1997

Striate cortical generators of the N75, P100 and N145 components localized by pattern reversal visual evoked magnetic fields.

Magnetic fields evoked by checkerboard pattern reversal visual stimulation to the monocular left or right half-field were recorded over the whole head using a helmet-shaped 64 channel magnetoencephalography system in fourteen normal subjects. The sources of the triphasic N75m-P100m-N145m responses were located using a single current dipole model. Relative locations and orientations of the N75m and N145m dipoles to the P100m dipole were calculated for each subject to reduce errors due to 'anatomical variability and then averaged for all subjects under the same stimulus conditions. These averaged parameters showed that N75m and N145m originated from the same location in the striate cortex as P100m and reversed their orientations successively by 180 degrees during the time course.

Adult↗
PubMed1997

Malignant lymphoma originating in the jejunum of a long-term follow-up case of protein-losing enteropathy.

A 50-year-old female patient, who had been followed for 15 years for protein-losing enteropathy, was hospitalized due to epigastric pain. Examination on admission revealed that the patient was in the sub-ileus state. On the 26th day after admission, she complained of severe abdominal pain and shortly after she went into shock. The emergency laparotomy documented intestinal perforation and a tumor. The perforated site was right at the middle of tumor. The histological and histochemical studies identified the tumor as malignant lymphoma of B lymphocyte lineage. As far as we know, this is the third case of malignant lymphoma occurring in the jejunum in a patient with protein-losing enteropathy in Japan. The possible relationship between lymphomas and protein-losing enteropathy is discussed.

Female↗
PubMed1997

Mitral regurgitation caused by mitral paraannular cyst.

A case of mitral regurgitation (MR) caused by mitral paraannular cyst is reported. A 37-year-old woman on maintenance hemodialysis was admitted to Akita University Hospital because of congestive heart failure. Echocardiography revealed mitral paraannular cyst, which caused coaptation failure of the mitral leaflets and significant MR. She underwent decapsulation of the cyst followed by mitral valve replacement. Postoperative echocardiography showed no recurrence of the cyst three years after surgery. Although mitral annular calcification has been described as a cause of MR in patients with uremia, a report of a solitary intracardiac cyst which causes significant MR is quite rare.

Adult↗
PubMed1997

Reproductive status in GTD treated with etoposide.

OBJECTIVE: To investigate the mechanism and degree of ovarian dysfunction in gestational trophoblastic disease (GTD) patients treated with etoposide alone. STUDY DESIGN: Forty-seven patients with low-risk GTD were treated with etoposide alone, and pituitary-ovarian function was evaluated by measuring basal serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol and progesterone and by recording basal body temperature. Moreover, the responses of LH and FSH to the administration of LH-releasing hormone (LHRH) and the responses of prolactin to thyrotropin-releasing hormone (TRH) were analyzed after the completion of etoposide treatment. RESULTS: Increased basal LH and FSH levels were found in approximately 50% of patients, especially those over 40 years old. Although the LH and FSH responses to LHRH were exaggerated in patients with high basal FSH levels, the prolactin responses to TRH were normal. Ovulation resumed within 121 days after the cessation of chemotherapy in women under 39 years. However, five of nine patients over 40 years remained anovulatory during the follow-up period. CONCLUSION: Ovarian function was impaired in approximately 50% of patients treated with etoposide at the time of LHRH study, though pituitary function was preserved. This complication is age related but not related to the amount of etoposide exposure. Therefore, we must consider the possibility of permanent anovulation when we treat patients 40 years old and older.

Adult↗
PubMed1997

[Effects of long-term ethanol administration (1). Effects of long-term ethanol administration on kidney studied at several periods of time during the administration].

The kidney is an important organ having not only excreting function but also other functions such as production of the substances that activates a living body, enzymatic reaction, immunization etc. For several years we have carried out experiments of ethanol administration to rats and involved observations of various organs including the kidney. Thus we have recognized no small effect of ethanol on the kidney. After ethanol administration, the ethanol and its metabolites go through kidneys and are excreted into urine, and their content of the urine is higher than that of the blood. Their content of the kidney is higher than that of the liver. In view of all these facts, the ethanol effect on kidney is easily assumed. In this study a comparison between effect of ethanol on kidney and that of the liver was made at several periods of time during the administration. Under short, a week ethanol administration, the direct action that exerts on cells is as follows: in the kidney swelling of glomerula and tubules, proliferation of mesangial cells, and hyaline drop in tubular epithelial cells are seen; in the liver storing of small fat drops and enlargement of Kupffer cells are observed. Under long, two month administration, products like ethanol metabolites-protein adducts and hyaline in tubular epithelial cells as their removal reaction are observed in the kidney; in the liver, enlargement of Kupffer cells in shown. Under long administration of six and eleven months, kidney shows atrophy of tubular epithelial cells, urinary casts, and cell infiltration to interstitial tissue; liver shows fat storing and bile duct proliferation. These changes found through the effects of age appear in the experimented rats earlier than the control. In addition thickening of basement membrane of glomerulus, PAS positive deposits in glomerulus, and proliferation of mesangial cell are observed in the kidney. It was apparently observed that effects of ethanol on the kidney appeared earlier than those on the liver.

Administration, Oral↗
PubMed1997

[Postoperative normalization of prolonged P100m latency in the visual evoked magnetic field in a patient with occipital meningioma].

A 49-year-old female with a left occipital parasagittal meningioma was found to have prolonged P100m latency of the pattern reversal visual evoked magnetic field only in the hemisphere containing the lesion. After total removal of the tumor, the P100m latency was normalized in the affected hemisphere. Based on current dipole models, all the P100m dipoles were localized at the lateral bottom of the calcarine fissures bilaterally, as indicated by our previous study with normal subjects. Since the tumor was located near the parietoocipital sulcus and distant from the primary visual cortex, disturbance of the higher visual cortex probably affected the P100m latency.

Brain Mapping↗
PubMed1997

Corticotrophin and vasopressin responses to metoclopramide in patients with hypothalamic amenorrhoea.

OBJECTIVE: A dopamine (DA) antagonist, metoclopramide, stimulates ACTH secretion in some women with hypothalamic amenorrhoea (HA) but not in normal women. Metoclopramide may stimulate ACTH secretion by decreasing dopaminergic inhibition of ACTH release. Furthermore, metoclopramide stimulates AVP secretion, and AVP is a stimulator of ACTH. Therefore, AVP may also be involved in the ACTH responses to metoclopramide. The relation between AVP and ACTH responses to metoclopramide were evaluated in normal women and women with HA to obtain more insight into the role of DA in the regulation of ACTH and AVP secretion. DESIGN: ACTH, cortisol and AVP levels were measured before and after the administration of metoclopramide in 11 normal women during the early follicular phase and 12 women with HA. MEASUREMENTS: ACTH was measured by immunoradiometric assay. AVP and cortisol were measured by radioimmunoassay. RESULTS: The administration of metoclopramide significantly increased circulating levels of ACTH and cortisol in the women with HA, but not in the normal women. It increased AVP levels both in the normal women and in the women with HA. The incremental AVP response to metoclopramide was not significantly different between the two groups of women. CONCLUSION: The effect of metoclopramide on AVP secretion may not be dependent on central dopaminergic activity, and the ACTH and cortisol responses to metoclopramide in the women with hypothalamic amenorrhoea are not accounted for by the augmented AVP response to metoclopramide.

Adrenocorticotropic Hormone↗
PubMed1997

Pustulotic arthro-osteitis associated with acetabular cartilage lesion in pustulotic arthropathy--implication of bone marrow.

We describe a case of pustulotic arthro-osteitis with hip joint involvement. After right hip joint and walking did not improve despite drugs and physical therapy, total hip replacement was performed. During surgery, brownish degenerated tissue was detected on the surface of the acetabular side. Pathohistological examination revealed that granulation tissue caused by suppurative inflammation of the bone marrow had broken through the cartilage surface, reaching the superficial layer. Our findings suggest that hip joint lesions in pustulotic arthro-osteitis may originate from bone marrow lesions.

Acetabulum↗
PubMed1997

Histological and immunohistochemical diversities, and proliferative activity and grading in osteosarcomas.

To examine the differentiation and proliferative activity of tumor cells, 30 osteosarcomas, including osteoblastic, chondroblastic, fibroblastic, malignant fibrous histiocytoma-like, telangiectatic, giant cell-rich low-grade central, and epithelioid types, were studied immunohistochemically. A variable number of tumor cells in all cases showed osteocalcin immunoreactivity. In four preparations of the frozen sections, osteoblastic, fibroblastic, and chondroblastic tumor cells were positive for bone-type alkaline phosphatase antibody 2D3. S-100 protein immunoreactivity was found not only in seven tumors of the chondroblastic type, but also in four of nine osteoblastic tumors and each of the low-grade central, giant cell-rich, and epithelioid types. A histiocytic marker, CD68, was negative for tumor cells in all cases. Some cells of 17 tumors were positive for desmin and/or alpha-smooth muscle actin; this was regarded as an indication of myofibroblastic differentiation. Tumor cells of the epithelioid type and those of two osteoblastic tumors expressed cytokeratin (CAM5.2) and epithelial membrane antigen. Proliferating-cell nuclear antigen (PCNA) reactivity was found in the cell nuclei of 22 tumors, most of which were high grade. Many cells in six high-grade tumors also showed the nuclear staining for p53 protein. Of these tumors, PCNA and p53 positivities tended to be more numerous in osteoblastic cells, atypical spindle-shaped, and bizarre giant cells than in well-developed chondroid cells. From these findings, osteosarcomas are concluded to be composed basically of osteoblastic cells, that are indispensable for diagnosis of osteosarcomas, with a variable number of chondroblastic, myofibroblastic, and, rarely, epithelioid cells, and this manifold cellular differentiation corresponds to the histological and clinical diversities. The osteoblastic, fibro- or myofibroblastic, and undifferentiated cells mainly participate in proliferation of osteosarcomas. The p53 gene alterations may play a part in the neoplastic transformation and proliferation of osteosarcomas.

Alkaline Phosphatase↗
PubMed1997

[A patient with psoriatic arthritis due to generalized pustular psoriasis (von Zumbusch type)].

Pustular psoriasis is a rare skin disease that is observed in about 1% of all patients with psoriasis. We encounted a patient with psoriatic arthritis (PsA) due to pustular psoriasis. The patient was a 31-year old male. He visited our hospital due to generalized eruption and pain in multiple joints. Treatment was initiated under a diagnosis of psoriasis vulgaris and associated PsA. However, eruption extended to the entire body and became pustular, and fever developed. Since PsA symptoms were simultaneously aggravated, and body movements become difficult, he was admitted. A diagnosis of generalized pustular psoriasis (von Zumbusch) and associated symmetrical polyarthritis was made. Local therapy was performed. As systemic treatment, oral administration of an corticosteroid and weekly low-dose pulse methotrexate therapy were performed. The skin symptoms and PsA symptoms rapidly improved. At present, about one year after the initiation of treatment, the eruption almost completely disappeared, and joint pain does not present any problem in daily life.

Adult↗
PubMed1997

[A slowly progressed case of brain metastasis and meningeal carcinomatosis from lung cancer].

We reported a case of long survival brain metastasis and meningeal carcinomatosis from lung cancer without radiochemotherapy. A 59-year-old female admitted to our hospital suffered from headache, anorexia and nausea. Papilledema was noticed, and examinations showed a brain tumor in the left parietal lobe and cancer cells in cerebrospinal fluid. Removal of the tumor and ventriculoperitoneal shunt were performed. Pathology showed adenocarcinoma. No neurological deficit was found during the postoperative course and the patient asked for home treatment. She survived for 25 months and spent a useful life in the 15 months after the onset in spite of no radiochemotherapy for meningeal carcinomatosis. In this case, because of the slow progression of the clinical symptoms, it is considered that cancer cells in the cerebrospinal fluid space grow slowly. The first CT and MRI findings of metastatic tumor of this case showed atypical for brain metastasis. Calcifications were found in plain CT and a high intensive tumor in both T1 and T2 weighted images of MRI. Enhancement due to contrast media was very slight in both CT and MRI. We considered that these findings were related to the slow growing of cancer cells.

Adenocarcinoma↗
PubMed1997

[A case of chronic expanding epidural hematoma].

A 7-year-old female was admitted to our hospital with complaints of headache and nausea following mild head injury. Computed tomography (CT) showed a small epidural hematoma (EH) in the right frontal area, but she was kept under observation because of these mild symptoms. Two weeks after admission, repeat CT showed that the EH had gradually increased in size with decreased clot density. A rim of high density was observed on the dural surface. Craniotomy was performed on the 15th day after admission to evacuate the EH. The brown-fluid hematoma was encapsulated by membrane on the dural surface and under the skull. CT 4 months after the operation-showed complete resolution of the EH. Histological examination suggested that chronic expansion of EH had occurred due to repeated hemorrhages from the dural surface membrane.

Child↗
PubMed1996

Nitric oxide modification of rat brain neurogranin affects its phosphorylation by protein kinase C and affinity for calmodulin.

Neurogranin (Ng) is a prominent protein kinase C (PKC) substrate which binds calmodulin (CaM) in the absence of Ca2+. Rat brain Ng contains four cysteine residues that were readily oxidized by nitric oxide (NO) donors, 1,1-diethyl-2-hydroxy-2-nitrosohydrazine (DEANO) and sodium nitroprusside, and by oxidants, H2O2 and o-iodosobenzoic acid. NO oxidation of Ng resulted in a conformational change detectable by increased electrophoretic mobility upon SDS-polyacrylamide gel electrophoresis. The NO-mediated mobility shift was reversed by treatment with dithiothreitol and was blocked by modification of Ng sulfhydryl groups with 4-vinylpyridine. Both the nonphosphorylated and PKC-phosphorylated Ng were susceptible to NO oxidation. Modification of Ng by DEANO was blocked by CaM in the absence of Ca2+; while in the presence of Ca2+, CaM did not protect Ng from oxidation by DEANO. CaM also failed to protect DEANO-mediated oxidation of PKC-phosphorylated Ng with or without Ca2+. Oxidation of Ng by the various oxidants apparently resulted in the formation of intramolecular disulfide bond(s) as judged by a reduction of apparent Mr on SDS-polyacrylamide gel electrophoresis; this oxidized form, unlike the reduced form, did not bind to CaM-affinity column. The oxidized Ng was also a poorer substrate for PKC; both the reduced and oxidized forms had similar Km values, but the Vmax of the oxidized form was about one-fourth of the reduced one. When comparing the rate of DEANO-mediated nitrosation of Ng with other sulfhydryl-containing compounds, it became evident that Ng ranked as one of the best NO acceptors among those tested, including serum albumin, glutathione, and dithiothreitol. Ng present in the rat brain synaptosomal preparations was also oxidized by DEANO in a dose-dependent manner when analyzed by immunoblot with a polyclonal antibody against this protein. These results suggest that Ng is a likely target of NO and other oxidants and that oxidation/reduction may serve as a mechanism for controlling both the PKC phosphorylation and the CaM-binding affinity of this protein.

Animals↗
PubMed1996

Firing rate modulation of human motor units in different muscles during isometric contraction with various forces.

To examine the factors affecting the control of human motor units, rate coding strategies of the motor units were investigated in upper limb and intrinsic hand muscles during voluntary isometric contraction of steady force levels up to 80% of maximal voluntary contraction. Numerous spike trains from single motor units were recorded from the m. first dorsal interosseous (FDI) and the m. biceps brachii (BB) of eight human subjects by means of tungsten micro-electrodes, and the mean firing rate (MFR) was calculated for each subject and inter-individual comparisons made. The MFRs of the FDI were larger than that of the BB at the higher force level, and substantial differences were not found between these muscles at the lower force level. The slope of the linear regression line of MFRs vs. exerted forces for the FDI was more than twice that for the BB. Therefore, isometric force control of the FDI depends more on the rate coding strategy. The difference in rate coding between the FDI and BB motor units may be determined by factors other than muscle fiber composition, because both muscles are known to possess a similar composition of fiber types. Possible mechanisms underlying these characteristics of rate coding strategy are considered in this report.

Adult↗