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Biomedical subjects

Y Endo

Publications and source records attributed to Y Endo.

At least 505 records · Page 28Linked to original sources
PubMed1990

Diurnal variation of cerebral blood flow in rat hippocampus.

We measured local cerebral blood flow over 24 hours in 10 unanesthetized, freely moving rats to determine whether blood flow in the hippocampus fluctuated as a function of time of day. We measured hydrogen clearance at 1-hour intervals using a polyurethane-coated platinum electrode with a 1-mm bare tip implanted in the dorsal hippocampus. Individual rats displayed a wide range of local cerebral blood flow values (from 30 to 100 ml/min/100 g tissue) in a day. In seven of the 10 rats, the overall mean hippocampal blood flow for the dark cycle (7 PM-5 AM) was significantly (p less than 0.001, 0.01, or 0.05) greater than that for the light cycle (6 AM-6 PM), showing an average increase of 20%. Further, the maximum mean hippocampal blood flow at 11 PM in all 10 rats was 42% greater than the minimum at noon. Our study demonstrates for the first time that local cerebral blood flow in the hippocampus shows diurnal variation.

Animals↗
PubMed1990

The distinct roles of alpha- and beta-subunits of human thyrotropin in the receptor-binding and postreceptor events.

The roles of alpha- and beta-subunits of human TSH (hTSH) were studied by investigating the inhibitory effects of monoclonal antibodies on the biological activity of hTSH. Four monoclonal antibodies directed toward different epitopes on the beta-subunit (hTSH beta) inhibited completely the receptor binding of hTSH to FRTL-5 rat thyroid cells. In contrast, five monoclonal antibodies directed toward different epitopes on the alpha-subunit had little or no effect on the receptor binding. Furthermore, four of five alpha-subunit-specific antibodies and three of four hTSH-specific antibodies inhibited both hTSH-induced cAMP accumulation and thymidine uptake in FRTL-5 cells, in a dose-response manner. One hTSH (alpha-beta heterodimer)-specific antibody which did not recognize the free subunits also had the inhibitory effect on both the receptor binding and hTSH-induced cAMP accumulation. These results strongly suggest that hTSH beta is indispensable for recognizing the receptors on FRTL-5 cells and that the alpha-subunit is required for signal transduction in postreceptor step(s). In addition, it is also suggested that the highly conformational structure of hTSH is absolutely essential for the biological activity.

Animals↗
PubMed1990

[Changes in protein phosphorylation during acrosome reaction of mouse sperm].

The changes of protein phosphorylation were analyzed during mouse sperm capacitation and acrosome reaction. Sperm adenosine 3',5'-cyclic monophosphate (cAMP) levels were gradually elevated during capacitation period. Although 32P uptake by sperm and protein phosphorylation increased during capacitation, the phosphorylation of a 45-kDa protein remained to be relatively constant. It was also demonstrated that acrosome reaction was induced by the treatment of capacitated sperm with 0.1 mM dibutyryl cAMP, 10 mM dibutyrylguanosine 3',5'-cyclic monophosphate, 20 microM calcium ionophore A23187 or acid-solubilized zonae pellucidae. The phosphorylation of a 45-kDa protein was augmented during the acrosome reaction induced by such agents. These results suggest that changes in protein phosphorylation might be involved in the regulation of mouse sperm capacitation and acrosome reaction.

Acrosome↗
PubMed1990

The Wolff-Parkinson-White syndrome in a Holstein-Friesian cow.

A case of Wolff-Parkinson-White (WPW) syndrome in a Holstein-Freisian cow aged 10-year-old was examined in detail. In electrocardiogram (ECG), the P-wave was the same configuration in both the normal and abnormal ECG. The PR-interval shortened from 0.2 to 0.1 second and the duration of the QRS-complex prolonged from 0.1 to 0.12 second compared with normal ECG. The delta wave, characterized in WPW syndrome, could not be recognized. In echocardiogram, notches were recognized at the early stage of ventricular contraction in the interventricular septum. This cow was, therefore, diagnosed as type B WPW syndrome. The abnormal ECG disappeared by the administration of procainamide. It was strongly indicated that the ventricular contraction showing abnormal ECG was generated only by the stimulation through an accessory pathway in this cow.

Animals↗
PubMed1990

The roles of endogenous opioids in the inhibitory action of the hippocampus on preovulatory luteinizing hormone in rats.

Whether endogenous opioid peptides were involved in the inhibitory action of the hippocampus (HPC) on luteinizing hormone (LH) release was studied examining the effect of naloxone, an opioid antagonist, on the inhibitory action of electrical stimulation of the HPC and also by examining the effect of metenkephalin administration in the HPC, on preovulatory release of LH in proestrous rats. In rats treated with saline at 13:00 h, either sham stimulation or electrical stimulation of the dorsal HPC, which was performed acutely under ether anesthesia, significantly inhibited the afternoon rise in serum LH. In animals treated with naloxone at a dose of 2.0 mg/kg body weight, the afternoon rise in LH appeared smaller than that in the control group. However, statistical analysis showed no significant difference in LH values compared to the control group. Direct administration of met-enkephalin at a dose of 10 micrograms at 13:00 h through a chronically implanted cannula in the HPC did not induce any significant change in the afternoon rise in LH, regardless of whether it induced behavioral seizures or not. The results suggest that opioid peptides in the HPC do not play a significant role in the inhibitory action of HPC on LH release. Opioids existing in areas other than the HPC may play a certain, but small role.

Animals↗
PubMed1990

[Suppression of evoked otoacoustic emissions by contralateral noise exposure in humans].

The effects of contralateral noise exposure on evoked otoacoustic emission (e-OAE) were investigated in 10 normal hearing subjects and 3 cases with unilateral deafness. The e-OAE was recorded by ILO88 and weighting noise was given to the contralateral ear (impaired side in unilateral deafness cases). The air conducted noise exposure showed suppressive effect on e-OAE along with the increase of noise stimulus intensity in normal hearing subjects, but did not in unilateral deafness cases. The degree of suppression in e-OAE was most remarkable in highest peak power between 1 kHz and 2 kHz in FFT picture and the mean value of maximal suppression in 10 normal hearing subjects was 2.2 dB. The bone conducted noise exposure showed no effects on e-OAE in either normal hearing subjects or unilateral deafness cases. It was suggested that the contralateral noise exposure could suppress the function of cochlear micromechanics probably via crossed olivocochlear bundle.

Acoustic Impedance Tests↗
PubMed1990

[Structure-function relationship of glycoprotein hormone].

Thyroid-stimulating hormone (TSH) is a member of a family of heterodimeric glycoprotein hormones which have a common alpha-subunit but differ in their hormone-specific beta-subunit. To date, numerous studies have been carried out to elucidate the structure-function relationship of glycoprotein hormones and molecular mechanism of hormone action. On the other hand, several types of abnormality in the structure and function of glycoprotein hormones, as well as TSH, have been observed in clinical samples, especially in malignant diseases. To approach the structure-function relationships of bioactive molecules, monoclonal antibodies have proven to be excellent tools. In the present study, on the basis of epitope analysis using 19 different monoclonal antibodies against human TSH, the surface structure of this hormone was proposed in a two-dimensional map. The epitope map of TSH was useful for construction of available immunoassays for this hormone and its subunit, and to detect the abnormality in the structure of recombinant TSH. Further studies were attempted to assess the effects of monoclonal antibodies on the function of TSH. Consequently, our results suggest that the beta-subunit is indispensable for recognizing the receptor and that the alpha-subunit is required for signal transduction in postreceptor step(s). The applications of the present analysis are underway to detect the abnormalities in the structure and function of TSH in clinical specimens.

Animals↗
PubMed1990

[Towards cloning the gene responsible for myotonic dystrophy].

For the purpose of cloning the gene of myotonic dystrophy (DM) using the technique of reverse genetics, we have introduced new methods such as microdissection, a YAC library and a Not I linking library and cloned many DNA fragments derived from the region of 19q13.2. Then we have assigned these to chromosome 19 by linkage map (CEPH families and linkage disequilibrium) and physical map (PFGE and in situ hybridization). Here we have described these methods.

Chromosome Mapping↗
PubMed1990

A new assay to measure RNA N-glycosidase activity.

We have developed a convenient procedure to measure the activity of Ricin A-chain and other enzymes with RNA N-glycosidase activity. The method is based on the use of a tritiated oligoribonucleotide as a substrate. The enzymatic activity is directly determined by measuring the release of adenine from the substrate. This method should prove useful in the study of the molecular mechanism of action of Ricin A and other RNA N-glycosidases.

Animals↗
PubMed1990

[A case report of pleural involvement in primary macroglobulinemia].

A case of primary macroglobulinemia with pleural and gastric involvement was presented. A 48-year-old female was admitted with productive cough. On physical examination neither lymphoadenopathy nor hepatosplenomegaly were found. In addition, no bleeding tendency nor disturbance of the visual acuity were detected. Her chest roentgenogram showed a moderate amount of pleural effusion in the left pleural cavity without infiltration in the lung fields and no evidence of swollen hilar or mediastinal lymphnodes. A monoclonal M-band of to IgM-kappa type was observed in her serum and the pleural effusion. The diffuse ulcerative lesion in the gastric mucosa was detected by gastrofiberscopy. The lymphoid cells taken from the pleural effusion and the gastric mucosa stained positively with fluorescein-conjugated antiserum to u or the kappa chain. Pleural effusion and gastric infiltration of lymphoid cells improved remarkably following ACOP therapy.

Female↗
PubMed1990

[Effects of the synthetic proteinase inhibitor, FOY, on hypercoagulability after surgery for esophageal carcinoma].

Hypercoagulability develops after surgery for esophageal carcinoma, and it related closely to postoperative complications. This study evaluated the effects of the synthetic proteinase inhibitor, Cabexate Mesilate (FOY), on this hypercoagulability. The subjects used were 25 patients with a mean age of 63 who had undergone surgery for esophageal carcinoma. Of these, eight patients (test group) received FOY (2,000 mg/day) for three to 23 days after surgery, but 17 (control group) did not. In the test group, FOY controlled aggregation and release of the platelets and minimized their exhaustion. FOY almost completely checked the abnormal increase in thrombin activity which might trigger the hypercoagulability. Also, FOY suppressed the fibrinolytic activity slightly. These results indicate that FOY is effective in controlling hypercoagulability after surgery for esophageal carcinoma and in suppressing activity of the proteinases that cause both blood coagulation and fibrinolysis.

Adult↗
PubMed1990

A study of recording accuracy in linear measurements displayed by sirognathograph.

The recording accuracy of Sirognathograph (Siemens, West Germany) was conducted by means of an experimental apparatus. Diagrams of mandibular border movements in three dimensional directions were performed. The results showed the distortion was not recognized within 5 mm of primary condition in a subject, but slightly between 5 mm and 10 mm. In a distance of more than 15 mm, a considerable distortion was increased until at the maximum opening position.

Dental Equipment↗
PubMed1990

[A study on display and accuracy of occlusal contacts by means of T-Scan System].

The various methods were introduced in the daily prosthodontic field evaluating occlusal contacts for diagnosis and analysis. Maness in 1987 developed the T-Scan system, which is considered as a new computerized device capable to interpret occlusal contacts information quantitatively. The system is composed of a sensor, sensor frame, handle, cable and system unit. Record and analysis mode made possible the occlusal contacts in three ways, such as the balance plot, the time display and comparison screen. However, accuracy and reproducibility of occlusal marking through this system is still uncertain. Therefore, this preliminary study was conducted on four specific points loaded on a sensor by application of the weight of 0.1 kg through 10 kg. The following results were obtained 1. There exists certain non-sensible areas caused by its constructional feature. 2. The most sensible area can be measured from 0.1 Kg to 2.1 Kg, and therefore, this device is more suitable for recording within lower loadings. 3. Although the system has a certain disadvantage of reproducibility, this contributes to attain diagnosis and treatment of occlusal contacts for a quantitative evaluation.

Dental Occlusion↗
PubMed1990

[Pure red cell aplasia induced by B19 parvovirus during allogeneic bone marrow transplantation].

We report a patient who had abrupt onset of pure red cell aplasia (PRCA) induced by B19 parvovirus during allogeneic bone marrow transplantation (BMT). A 14-year-old girl with APL in complete remission was admitted in February 1988, for the purpose of BMT. She was received marrow from HLA identical sister on March 17, 1988 (day 0). She received 120 mg/kg cyclophosphamide and 12 Gy total body irradiation for conditioning of BMT. For graft-versus-host disease (GVHD) prophylaxis she was given cyclosporine and short term methotrexate. She did not develop acute GVHD after BMT, but on the day 28 a bone-marrow aspirate revealed findings of PRCA. During this course the number of white blood cell and platelet favorably recovered. B 19 parvovirus DNA was detected in the serum of the day 30 and day 42. Antihuman B 19 parvovirus (HPV) antibody titers were increased: the values of anti-HPV IgM were suddenly elevated and those of anti-HPV IgG were elevated. Serum on the day 42 inhibited erythroid progenitors (CFU-E, BFU-E) but not inhibited myeloid progenitors (CFU-C). A reticulocyte count recovered on the day 50. As the patient was HPV-IgG negative prior to BMT and the donor was HPV-IgG seronegative, the source of infection may be platelet transfusion (day 7 through 14).

Adolescent↗
PubMed1990

[A continuous-step density percoll gradient for use in AIH and life table analysis of pregnancy rates].

For use in artificial insemination with husband's semen (AIH), a continuous-step Percoll density gradient technique was used to wash and concentrate sperm from ejaculate. To evaluate usefulness, the pregnancy rates were analyzed by the life table method. 1. After washing by the continuous-step Percoll density gradient method, sperm density increased from 28.8 X 10(6)/ml (original semen) to 40.9 X 10(6)/ml and sperm motility improved from 52.4% (original semen) to 77.0% respectively. 2. A group of 119 infertile patients whose diagnosis involved oligoasthenozoospermia, cervical factor and unexplained infertility were selected for AIH. After 640 insemination cycles, 37 women conceived with a pregnancy rate of 31.1%. By using life table analysis, the cumulative conception probability rate reached 0.652 after 13 insemination cycles. 3. Cumulative pregnancy rates by diagnostic category were 0.494 in male factor and 0.745 in cervical factor after 12 cycles, respectively. 4. The poorest results were obtained in unexplained infertility with a cumulative pregnancy rate of only 0.355 after 12 cycles. 5. In the follow up study, 24 viable babies were born and seven (18.9%) resulted in spontaneous abortion in the first trimester. These results indicate that the continuous-step Percoll density gradient technique is useful for improving the pregnancy rate in AIH.

Adult↗