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Biomedical subjects

H Seki

Publications and source records attributed to H Seki.

At least 217 records · Page 12Linked to original sources
PubMed1990

Cognitive impairment in Parkinson's disease assessed by visuomotor performance system and P300 potential.

Motor impairment, clinically defined as bradykinesia has been considered as resulting only from motor system problems. Combined analysis of cognitive function and dynamic characteristics was studied in 20 patients with Parkinson's disease by a simple aiming task on visuomotor performance system. The dynamic characteristics in a Parkinson's disease patient was evaluated by two parameters: decreased amplitude of the voluntary movement (= low gain constant) and delayed initiation of voluntary movement (= long reaction time). The visual event-related potential elicited in a target detection paradigm (P300 component) was recorded in 12 patients with Parkinson's disease. P300 latency was significantly prolonged in the patient group than in the normal control group (p less than 0.05). P300 has been shown to be intimately related to the cognitive process in the human brain and might well serve as a tool to monitor and evaluate the cognitive state in a clinical situation. The main cause of cognitive involvement in Parkinson's disease may include coexisting dementia and defective motivation. This type of cognitive disturbance may also serve partly as a cause of bradykinesia.

Adult↗
PubMed1990

[Significance of the PGI2 producing enzyme system in the pathogenesis of pregnancy-induced hypertension].

Characterization of the PGI2 producing enzyme system (P.E.S.) in pregnancy induced hypertension (PIH) was carried out by comparing its conversion from arachidonic acid (A.A.) or PGH2 to PGI2 using enzyme preparations from endothelial cells of the umbilical vein in normal pregnancy (N) and mild (M) and severe (S) types of PIH. 1) The conversion rate from A.A. to PGI2 in N was significantly (p less than 0.05) higher than in M and S. 2) The conversion rate from PGH2 to PGI2 in N was higher than in M and that in M was higher than in S. 3) The apparent Vmax values (nM/mg protein) (mean +/- S.E.M.) for P.E.S. in N (0.88 +/- 0.21) were significantly (p less than 0.05) lower than in M (2.76 +/- 0.71) and S (1.63 +/- 0.18). The apparent Km values (microM) (mean +/- S.E.M.) for P.E.S. in N (0.76 +/- 0.25) were significantly (p less than 0.05) higher than in M (0.29 +/- 0.07) and significantly (p less than 0.05) lower than in S (3.26 +/- 0.78). 4) The apparent Vmax values for PGI2 synthetase (P.S.) in N (0.44 +/- 0.09) and M (0.61 +/- 0.10) were significantly (p less than 0.05) higher than in S (0.11 +/- 0.06). The apparent Km values for P.S. in N, M and S were 0.12 +/- 0.07, 0.13 +/- 0.06 and 0.16 +/- 0.04, respectively. The present study showed that the symptoms in M may be kept from becoming aggravated by the production of large amounts of PGI2, due mainly to activation of cyclooxygenase, whereas progressive disorder of the regulation of blood pressure in S may be caused by low production of PGI2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Two cases of subcortical hemorrhage with asymptomatic occlusion of the main trunk of cerebral artery].

We report two cases of asymptomatic occlusion of the main trunk of the cerebral artery associated with subcortical hemorrhage in the area fed by collateral circulation. The first patient, a 51-year-old female who had suffered from untreated hypertension for 20 years, was hospitalized in a state of coma. Computed tomography (CT) revealed a subcortical hemorrhage in the right parietal lobe as well as subdural and subarachnoid hemorrhages. Cerebral angiography disclosed occlusion of the right internal carotid artery at its origin. The region normally supplied by the right anterior (ACA) and middle cerebral (MCA) arteries was supplied instead by the posterior cerebral artery via leptomeningeal anastomosis. The hematoma was removed and the patient was discharged 1 month later. The second patient was a 54-year-old female who had suffered from uncontrollable hypertension for 27 years and was hospitalized after sudden development of stupor, right hemiparesis and motor aphasia. CT demonstrated a subcortical hemorrhage in the left parietal lobe. Cerebral angiography disclosed occlusion of the left MCA at its origin. The area normally fed by the left MCA was supplied instead by the ACA by way of leptomeningeal anastomosis. One month after operation the patient was transferred to another hospital for rehabilitation of right hemiparesis. Both of these middle-aged women had long-standing hypertension. The hemorrhages were thought to result from rupture of the leptomeningeal anastomosis, which had developed as collateral vessels. It is probable that the relatively weak leptomeningeal anastomosis could no longer withstand the increased blood flow brought on by the hypertension.

Arterial Occlusive Diseases↗
PubMed1990

[A case of hyperplastic polypoid lesion in the common bile duct hard to differentiate from early bile duct carcinoma].

In a 72-year-old male carcinoma of the bile duct was suspected because of an abnormality on laboratory examination. Ultrasound showed the dilatation of extrabiliary duct. Endoscopic ultrasound revealed localized wall thickening of the common bile duct. ERCP demonstrated the dilatation of the CBD. Within the dilated duct a filling defect was present. Histology of the resected specimen disclosed hyperplasia of the epithelium in the CBD.

Aged↗
PubMed1989

Molecular heterogeneity of gamma delta T-cell antigen receptors expressed by CD4- CD8- T-cell clones from normal donors: both disulfide- and non-disulfide-linked receptors are delta TCS1+.

We investigated the molecular heterogeneity of gamma delta T-cell antigen receptors (TCR) expressed on T-cell clones generated from peripheral blood lymphocytes of normal donors. Extensive molecular heterogeneity was seen at the gamma-chain level and, to a lesser extent, at the delta-chain level. Both disulfide and non-disulfide gamma delta TCR were found and use different gamma chains with similar molecular masses (range, 41-43 kDa). In contrast, gamma chains of 55-60 kDa, which are expressed on T-cell lines derived from the peripheral blood of patients with immunodeficiency disorders, were not found on T-cell clones derived from the peripheral blood of normal donors. delta chains expressed on these T-cell clones had a molecular mass of 37 kDa and were either disulfide or nondisulfide linked. Significant delta-chain heterogeneity was identified in these clones using the anti-delta TCS1 and the anti-TCR delta 1 monoclonal antibodies. All clones tested were TCR delta 1+, whereas only 25% of the clones were delta TCS1+. The anti-delta TCS1 monoclonal antibody stained and immunoprecipitated both disulfide- and non-disulfide-linked gamma delta TCRs from different T-cell clones from normal donors.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1989

Development of a monoclonal antibody specific for the gamma chain of the T-cell antigen receptor using an open reading frame expression vector.

To develop an anti-framework monoclonal antibody (mab) specific for the gamma (gamma)-chain of the T-cell antigen receptor (TCR), we expressed a part of the constant region of the gamma-chain (C gamma 2 gene segment) in E. coli using the pWR590 vector. This plasmid contains the E. coli lac promoter, operator, a truncated beta-galactosidase (beta-gal) gene (coding for the first 590 of the 1,007 amino acids of the beta-gal) and a polylinker region (at the 3' end of the beta-gal) containing nine restriction sites. These can be cleaved by any one of eight common restriction enzymes, permitting the introduction of the DNA fragment of interest. We employed the pT gamma 1 gamma-chain cDNA probe, which like the vast majority of the gamma-chain specific probes is aberrant and contains an in-frame stop codon at the junction of V and J regions. Computer analysis of the pT gamma 1 sequence revealed several MaeIII restriction sites that could result in a number of fragments. One of these fragments consisted of 245 base pairs (nucleotides 404-648) and contained most of the CI exon of the C gamma 2. Successful insertion of this fragment to the pWR590 vector was confirmed using restriction enzyme analysis. The C gamma insert was 12% of the construct. Expression of the pWR590-HpT gamma 1 recombinant plasmid in E. coli followed by SDS-PAGE analysis revealed a hybrid protein with a molecular weight of 85 kd which constituted at least 25% of the total E. coli insoluble protein. In contrast, cells transformed with the control pWR590 vector without insert expressed a 78 kd polypeptide chain. We developed several mabs against the pWR590-HpT gamma 1 hybrid protein by fusing spleen lymphocytes from BALB/c mice immunized with the pWR590-HpT gamma 1 protein, with cells of the NS1 mouse myeloma cell line. Screening of the mabs was carried out by ELISA against the pWR590-HpT gamma 1 hybrid protein and the control pWR590 beta-gal protein (beta-gal 590), derived by expressing in E. coli the pWR590 vector without gamma-chain insert. Two groups of mabs were obtained, those reacting with the pWR590-HpT gamma 1 hybrid protein only and those reacting with both the hybrid and the control beta-gal 590 proteins. The specificity of these mabs was further studied by Western blotting with similar results.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Disulfide-linked gamma delta T cell antigen receptors expressed on T cells derived from patients with primary immunodeficiency disorders.

T cell lines or clones from two patients, one with a partial DiGeorge syndrome and one with severe common variable immunodeficiency expressed disulfide-linked gamma delta T cell antigen receptor (TCR) comprised of a gamma-chain polypeptide of 40-43 kD, and a delta-chain polypeptide of 37-40 kD. This gamma delta TCR appears to be similar to that found on T cell clones, and lines derived from peripheral blood lymphocytes from normal donors. Previous studies have shown that T cell lines derived from the peripheral blood of patients with immunodeficiency disorders express non-disulfide-linked gamma delta TCR. In contrast to the latter and coincident with findings in the present study, the vast majority of T cell lines and clones derived from the peripheral blood of normal donors express disulfide-linked gamma delta TCR.

Antigens, CD↗
PubMed1989

[Influence of selenium on human health. Part 2. Relationship between selenium concentration in whole blood and physiological functions of the human body].

In order to study the influence of selenium (Se) on human health, the relationships between Se concentrations in whole blood and human body functions were studied in 331 healthy subjects living in Nagano Prefecture. The subjects with low concentrations of Se had lower values for hemoglobin, hematocrit, red blood corpuscles, and for the function of pulmonary ventilation, as well as lower concentrations of glucose and albumin. A lowered concentration of Se may result in anemia, even though a deficiency of iron cannot be observed. On the other hand, the subjects with high concentrations of Se had higher concentrations of uric acid, glucose and total cholesterol, higher values for diastolic blood pressure and the thickness of fat under skin, as well as a higher index of liver function. Moreover, these subjects had a good index of physical constitution and strength, and presented a large total consumption energy value. These results may show that in man, high Se concentrations in whole blood, indicate higher element concentrations in serum and better indexes of physical constitution and strength.

Adult↗
PubMed1989

Thallium-201 single photon emission computed tomography in the evaluation of suspected lung cancer.

Thallium-201 SPECT was performed in 30 patients with suspected lung cancer. Both early and delayed scans demonstrated abnormal accumulation in all of 23 malignant pulmonary lesions including 21 lung cancer and in two of seven benign conditions. There were significant differences in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) and retention index (degree of retention in the lesion) between lung cancer and benign conditions, respectively (p less than 0.01, p less than 0.05). The delayed ratio and retention index revealed that adenocarcinoma showed higher 201Tl accumulation than squamous cell carcinoma and small cell carcinoma (p less than 0.05) and 201Tl clearance in squamous cell carcinoma was faster than in the other two (p less than 0.05). Mediastinal involvement was detected in five of seven patients on delayed scans. The smallest lesion depicted was 1.5 cm in diameter. Two false negatives had small metastases less than 1.0 cm in diameter. This method seems to be useful to detect lung cancer, to differentiate malignant from benign lesions, and to evaluate mediastinal involvement from lung cancer.

Adenocarcinoma↗
PubMed1989

[Stabilized position of incisors after orthodontic treatment on reversed occlusion cases with skeletal imbalance. Application of quadrilateral analysis].

This study was made to evaluate the position of the incisors after orthodontic treatment on reversed occlusion cases with skeletal imbalance and to establish norms of the upper and lower central incisors on the quadrilateral (quadrilateral analysis) as the orthodontic treatment objectives through lateral cephalograms. The materials used for this study consisted of twenty-eight posttreatment lateral cephalograms which were taken at more than 2 years after active treatment, and twenty lateral cephalograms which were taken from young-adult females with normal occlusion. The treated samples were of twenty-eight females which were over 14 years old and had reversed occlusion with less than 2 degrees of ANB angle at first examination. These samples were divided into two groups: one consisted of 17 cases females with more than 0 degree of ANB angle and the other of 11 cases with less than 0 degree of ANB. And 11 cases which were treated with multi-bracket appliance alone were selected from the treated samples in order to examine the morphological changes during orthodontic treatment. The results were as follows: 1. In the treated sample the mean profile showed protrusion of the soft pogonion and had slightly forward position of the upper lip and the lower lip, but the outline from the subnasale to the soft pogonion coincided with that of the normal occlusion sample. 2. The ANB angle of the treated sample was smaller than that of the normal occlusion sample so that the mandible of the treated sample was prognathic. 3. The overjet of the treated sample revealed normally in spite of this skeletal disharmony because of compensation by labial inclination of the upper incisors and lingual inclination of the lower incisors. The stronger this skeletal imbalance was, the more the upper incisors inclined labially. But the Ll-Mp showed no difference between the groups which had more than 0 degree of ANB angle and that which less than 0 degree of ANB. 4. The edges of the maxillary and mandibular central incisors always were at a certain place from A'B' line not undergoing an effect of the jaw relationship, and the edge of the mandibular central incisor placed at 8 mm in front of A'B' line. 5. In the treated sample the mandibular central incisor positioned at 1 mm above the occlusal plane. 6. Occlusal plane-A'B' angles in the treated and the normal occlusion samples were revealed about 90 degrees.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1989

[The influence of ferric metabolism on Ga-67 distribution in the human body].

This investigation was undertaken to make clear the influence of ferric metabolism on Ga-67 distribution in human body. Count ratios for each organ to femoral soft tissue (i.e. relative Ga-67 uptake) were calculated in 125 scintigrams obtained 48 hours following injection, and the relation between the relative Ga-67 uptake in each organ and serum Fe, or UIBC were investigated. The relative Ga-67 uptake in the liver and the lumbar vertebra had negative correlation to serum Fe, and had positive correlation to UIBC. However, there was no significant difference in the relative Ga-67 uptake in the lumbar vertebra between normal and high serum Fe group. Only in group with exceedingly low serum Fe, each vertebral body was visualized separately in posterior view of the abdomen. These findings indicated that in group with exceedingly low serum Fe, Ga-67 accumulated mainly in the bone marrow, and in group with high serum Fe, Ga-67 accumulated mainly in the bone. The urinary bladder was visualized only in group with high serum Fe, which suggested that the excretion of Ga-67 to the urine was continued yet at 48 hours after injection. Ferric metabolism affected remarkably on the relative Ga-67 uptake in the liver, the bone marrow and the bone, and also the excretion of Ga-67 to the urine.

Adolescent↗
PubMed1988

Specificity of esterases and structure of prodrug esters: reactivity of various acylated acetaminophen compounds and acetylaminobenzoated compounds.

The relative rates of enzymatically catalyzed hydrolysis of various esters of p-acetylaminobenzoic acid (APAB) and variously acylated acetaminophen (APAP) derivatives were measured. Neutral, anionic, and cationic esters were examined. The enzyme sources adopted were rat intestinal homogenate, rat liver homogenate, rat plasma, and a partly purified commercial enzyme. In both APAB and APAP esters, neutral esters were the most sensitive of the enzyme sources examined, and the sensitivity was due to the carbon chain length. The APAB esters were enzymatically more stable than the APAP esters. The relative rates of hydrolysis of these esters varied depending on the enzyme source. The ability of structure recognition was good in rat intestinal homogenate, but weak in rat plasma. These results suggest that ester prodrugs can be designed to cleave preferentially at selected sites along the pathway between absorption and disposition in the body.

Acetaminophen↗
PubMed1988

Quantitative assessment of cerebral blood flow using technetium-99m-hexamethyl-propyleneamine oxime: Part I, Design of a mathematical model.

To design a mathematical model for quantifying cerebral blood flow using 99mTc-hexamethyl-propyleneamine oxime (HM-PAO), basic studies were performed in animals and human volunteers. Microautoradiography revealed that HM-PAO crossed the blood-brain barrier. Thin layer chromatographic studies demonstrated the rapid disappearance of free HM-PAO in the brain tissue. Back diffusion from brain to blood was found negligible. From these observations, the familiar microsphere model was employed in the measurements of blood flow with HM-PAO. This, however, resulted in much lower flow values than simultaneously obtained values with the labeled microspheres. This underestimation was ascribed to the high affinity of HM-PAO to blood cells and serum protein. Taking the binding of HM-PAO to blood components into consideration, the following model equation was designed for quantifying cerebral blood flow: Ce(t) = Ca(t)-kCa(t)*exp(-kt), Cb(T) = F integral of T0 Ce(t)dt, where Ce and Ca are the free HM-PAO concentration in the intravascular space and the arterial whole-blood concentration of HM-PAO, respectively, as a function of time (t), Cb is the brain activity concentration, k is the rate constant for the binding of HM-PAO to the blood components, F is the blood flow value, T is time of measurement, and * denotes the operation of convolution. In clinical studies, Ca(t) and Cb(T) are obtainable from a dynamic single photon emission computerized tomographic study of the brain and multiple arterial blood sampling, respectively. The values for F and k can be estimated using a nonlinear least squares fitting method.

Animals↗
PubMed1988

Intrathecal synthesis of immunosuppressive acidic protein (IAP) in patients with multiple sclerosis and other inflammatory neurological diseases.

Immunosuppressive acidic protein (IAP), an immunosuppressive substance produced mainly by macrophages, has previously been shown to increase in the serum of patients with inflammatory neurological diseases. In this study we assayed the IAP levels in cerebrospinal fluid (CSF) by a passive hemagglutination-inhibition test. CSF-IAP levels increased significantly in patients with multiple sclerosis (MS) during both the active and inactive stages and in patients with Guillain-Barré syndrome (GBS) or Miller Fisher syndrome (MFS) as compared with those of control patients, but not in patients with amyotrophic lateral sclerosis or spinocerebellar degeneration. During the active stage of MS, increased CSF-IAP levels together with the elevated IAP% (CSF-IAP/total CSF protein) and IAP index [(CSF-IAP/serum IAP)/(CSF albumin/serum albumin)] suggested the intrathecal synthesis of IAP. In contrast, in patients with GBS or MFS, increased CSF-IAP levels without elevation of IAP% could be attributed largely to increased total CSF protein levels. In patients with neuro-Behçet's disease, CSF-IAP levels and IAP% were elevated during the active stage, but remained normal levels during the inactive stage. Assaying CSF-IAP could provide useful information about inflammatory or immunopathological events within the central nervous system.

Hemagglutination Inhibition Tests↗
PubMed1988

Determination of flow and rate constants in a kinetic model of [99mTc]-hexamethyl-propylene amine oxime in the human brain.

The values for flow and rate constants for a kinetic model of [99mTc]-hexamethylpropyleneamine oxime (HM-PAO) distribution in the human brain were determined. The single-pass extraction ratio of HM-PAO was also determined in the rat brain by the indicator diffusion method; a value of 0.90 +/- 0.02 (mean +/- SEM, n = 5) was obtained. Time course data of brain activity and arterial blood activity of the tracer were fitted to a four compartment model: Values of blood flow and the first-order rate constants for backdiffusion of the diffusible tracer from brain to blood (k2), conversion of the lipophilic tracer to the hydrophilic one in brain (k3), and conversion of the diffusible tracer to the nondiffusible one in blood (k5) were determined. Conversion of hydrophilic tracer back to a lipophilic form in both blood and brain was assumed to be negligible during the course of the experiment. The values obtained for blood flow, k2, and k3 were, respectively, 0.40 +/- 0.03 ml/g/min, 0.38 +/- 0.04 min-1, and 0.92 +/- 0.05 min-1 in the gray matter (n = 4), and 0.23 +/- 0.01 ml/g/min, 0.17 +/- 0.01 min-1, and 1.01 +/- 0.05 min-1 in the white matter (n = 2) in patients with cerebrovascular disorder. The k5 value was 1.14 +/- 0.06 min-1 (n = 4). These experimentally determined values agree well with the theoretical ones previously reported by Lassen et al. The results suggest the relative constancy of the k3 and k5 values and the more prominent initial backdiffusion of the lipophilic HM-PAO from brain to blood in high flow regions compared to low flow regions.

Animals↗
PubMed1988

Direct autoradiographic comparison of 99Tcm-HMPAO with 125I-IMP in experimental brain ischaemia.

Local cerebral blood flow (LCBF) images of HMPAO and IMP were directly compared in experimental brain ischaemia in the same rats using a double-tracer autoradiographic technique. Both images were identical in distribution throughout the whole flow areas. However, LCBF values were much lower in HMPAO than in IMP. The results suggest that HMPAO acts as a chemical microembolus in rat brain in both low and high flow areas; however, a quantitative flow measurement is difficult in an HMPAO study.

Amphetamines↗
PubMed1988

[Spontaneous cerebrospinal fluid fistula in association with congenital inner ear anomaly: a case report].

A case of inner ear anomaly (Mondini dysplasia) associated with recurrent meningitis found in a 10 year-old boy is reported. The patient had suffered from bacterial meningitis and CSF rhinorrhea five times in 7 years. The origin of CSF leakage had not been detected by bifrontal craniotomy or trans-sphenoidal operation. In May 1985, the dysplasia of the temporal bone and the inner ear had been pointed out by an otologist. And he underwent operations a few times for closing the CSF fistula at the floor of the internal auditory meatus by translabyrinthine approaches, but in vain. On the 7th of November 1985, under the control of intracranial pressure by continuous ventricular drainage, re-operation was performed. Packing the internal auditory meatus with several pieces of muscle and gelatine sponge stopped the CSF leakage and the recurrence of meningitis.

Cerebrospinal Fluid Otorrhea↗