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Biomedical subjects

E Sato

Publications and source records attributed to E Sato.

At least 343 records · Page 19Linked to original sources
PubMed1990

[An inhibitory influence of porcine vasoactive intestinal peptide upon mouse oocyte meiosis in culture].

The germinal vesicle (GV) of follicle-enclosed oocytes in mice remains arrested at the dictyate state of meiosis. Upon releasing the oocytes from the follicles, the meiotic process resumes, leading to dissolution of the GV, suggesting that factors in the follicular constituents sustain the meiotic arrest of oocytes. Vasoactive intestinal peptide (VIP) was demonstrated in the ovary and found to have a wide range of biological effects. In this study, the possibility of VIP to be a factor which induces meiosis-arrest of oocytes was evaluated. Porcine VIP inhibited resumption of meiosis of cumulus-enclosed mouse oocytes in vitro. Germinal vesicle breakdown (GVBD) was prevented in more than 50% of the oocytes treated by VIP at a concentration of 30 microM. The inhibiting effect of VIP was dose-dependent and reversible. Spontaneous resumption of meiosis of isolated oocytes in vitro was reported to be inhibited by dibutyryl cAMP (dbcAMP) added to the medium, indicating that meiotic arrest can be sustained by maintaining intra-oocyte cAMP above a critical level. It was further reported that follicular fluid contains substances that maintain meiotic arrest in association with exogenous dbcAMP. In the present study, the blocking activity of dbcAMP for the spontaneous resumption of meiosis was not potentiated by the addition of VIP in the medium. The present results suggest that VIP may play a role in the regulation of resumption of oocyte meiosis, and that VIP is not a substance which maintains meiotic arrest in association with cAMP.

Animals↗
PubMed1990

Glycosaminoglycans in porcine follicular fluid promoting viability of oocytes in culture.

The viability of oocytes cultured in vitro was determined by the trypan blue exclusion test. Isolated porcine oocytes with or without cumulus cells cultured in modified Krebs-Ringer medium undergo cell death after 48 h. The addition of glycosaminoglycans (GAGs) prepared from porcine follicular fluid (pFF) to the medium delayed or prevented the onset of cell death in vitro. GAGs at concentrations of 0.25 mg/ml or greater prevented cell death in a dose-dependent manner. To identify the active factor, GAGs were purified from pFF by ethanol precipitation, chromatography on Dowex 1-x2, and high performance liquid chromatography (HPLC) on TSK gel DEAE-2 SW column. The fraction with a retention time nearly coincident with that of hyaluronic acid possessed high oocyte viability promoting activity. The present results suggest that the viability of oocytes in vitro is influenced by the presence of specific GAGs separated from follicular fluid.

Animals↗
PubMed1990

Partial trisomy of the distal segment 14q.

The case of a male infant with duplication of the distal segment of chromosome 14q is described. There was an extra chromosomal segment at the distal end of the long arm of chromosome 17. Banding techniques suggested that the extra segment might be the distal segment of chromosome 14q. DNA analysis using probes from distal 14q as well as from other parts of the genome confirmed that the extra segment consisted of the distal part of 14q. Both the proband's parents and his elder sister had normal karyotypes.

Abnormalities, Multiple↗
PubMed1990

A therapy against vasospasm after subarachnoidal haemorrhage: clinical experience of balloon angioplasty.

Vasospasm is a phenomenon often present in human cases after subarachnoidal haemorrhage. Its aetiology and pathophysiology are unknown. As a result, cases of vasospasm do not respond to any known pharmacological therapy. We present in this paper, a practical application of intravascular surgery for vasospasm. In this procedure the requirement for a portable digital subtraction unit, transcranial Doppler sonography, and being able to determine quickly the neurological state of the patient are very important points. The use of monitoring equipment is especially indispensable during the carrying out of percutaneous transluminal angioplasty (PTA), which should be performed as soon as possible after the occurrence of vasospasm. The case of a 54-year-old male patient suffering from a ruptured anterior cerebral artery aneurysm was studied. Neck clipping was performed on the second day. On the fifth day the neurological state was stupor, and transcranial Doppler sonography (TCD) revealed a flow velocity of over 100 cm s-1. PTA was performed on the sixth day. The bilateral middle cerebral artery was dilated and the flow velocity slowed to within the normal range. The neurological state improved to clouding of consciousness after PTA. On the eighteenth day, the patient's consciousness and bilateral carotid angiograms revealed the vessels to be dilated still. It was concluded that PTA therapy, and the use of a portable digital subtraction unit and TCD sonography, for vasospasm caused by subarachnoidal haemorrhage is useful and effective.

Angioplasty, Balloon↗
PubMed1990

Transcranial Doppler monitoring in severe brain damage: relationships between intracranial haemodynamics, brain dysfunction and outcome.

Transcranial Doppler (TCD) monitoring in the middle cerebral (MCA) and common carotid arteries (CCA) was studied in 105 comatose patients with severe brain damage. TCD-measured velocity waveforms in the MCA were evaluated in relation to loss of cerebral function as assessed by EEG and compressed spectral arrays, loss of brain stem function as measured by somatosensory and auditory evoked potentials, loss of all brain function and the clinical outcome. The velocity waveforms exhibited six patterns: continuous forward flow (FF); diastolic no flow (NF); diastolic reverse flow with (RF) or without (DRF) diastolic FF; brief systolic FF (SFF); and undetectable (U). In the 58 fatal cases, the appearance of RF/DRF or SFF in the MCA more often preceded loss of brain stem function than loss of cerebral function. A U pattern in the MCA, which was confirmed by loss of FF in the CCA, was correlated with loss of brain stem function. Only one of the 47 survivors showed DRF in the MCA. No patients in whom SFF or U was observed in the MCA survived. Therefore the presence of these patterns is reliably predictive of brain death. Intracranial diastolic reverse flow (DRF), however, indicates imminent loss of brain function and the need for prompt resuscitative measures.

Adolescent↗
PubMed1990

Expression of blood group antigens and lectin binding in adenocarcinomas of the endometrium.

To investigate cytoplasmic alterations in cancers of the endometrium, monoclonal antibodies against H, A and B blood group substances and related lectins such as Ulex europaeus agglutinin 1 (UEA-1), Lotus tetragonolobus agglutinin (LTA), and Griffonia simplicifolia 1 (GS1-A4, -B4) were applied to 42 cases of endometrial adenocarcinoma (EAC) and 11 adenomyoses. The control specimens consisted of normal endometria with leiomyoma or adenomyosis from patients of known blood group type. The brightest and most consistent staining was obtained with GS1-A4, showing 98% positivity in EAC in contrast to 18% in normal endometria. In contrast, expression of A antigen was seen in only 24% of EAC and in 13% of normal endometria, UEA-1 binding was seen in 81% of EAC and in 10% of normal endometria, whereas H antigen was seen in 60% of EAC and 0% of normal endometria. In adenocarcinomas, staining was seen not only along the luminal border of glands but also in the cytoplasm and the lateral or basal cell membranes, whereas in the normal endometrium staining was mostly along the luminal border. Thus, a difference in the positivity and localization of glycoconjugates was observed in neoplastic and non-neoplastic endometrium.

Adenocarcinoma↗
PubMed1990

Biclonality of composite B- and T-cell lymphomas. A case report.

Most composite lymphomas which are composed morphologically of two different tumor cell types are considered to represent different morphological expressions of a single clone. However, in recent years, composite B- and T-cell lymphomas and biclonality of B-cell lymphoma have been reported. We experienced a case of composite lymphoma which initially developed as cutaneous lymphoma composed of lymphoplasmacytes associated with large clear cells. It was confirmed that the tumor cells of these two systems were biclonal on the basis of surface markers and DNA rearrangements, i.e. B cells of the IgG kappa type, showing IgH and kappa chain DNA rearrangement, and T-cells with CD4 surface marker, showing rearrangement of the T-cell receptor beta chain gene. This case showed a predominant B-cell pattern at the initial stage, and terminated in T-cell lymphoma, as revealed at autopsy. Therefore we considered this case to be a unique composite lymphoma showing biclonality of both B- and T-cell systems, providing a number of suggestions for future study of malignant lymphoma.

Aged↗
PubMed1990

Novel fluorogenic substrates for phosphodiesterase I.

The fluorescence of 9,10-dioxa-syn-3,4,6,7-tetramethylbimane (bimane) was found to be quenched in the presence of guanosine 5'-monophosphate. By using this phenomenon, the bimane system was used for the fluorophor of substrates for phosphodiesterase I. Bimanes were coupled to 5'-guanylic acid and the resulting compounds were shown to be portent fluorogenic substrates for the assay of phosphodiesterase I.

Bridged Bicyclo Compounds↗
PubMed1990

Morphological differentiation of cumulus-oocyte complexes induced by the administration of gonadotropins in mice.

The morphological changes were examined in the present study in mouse cumulus-oocyte complexes and granulosa cells induced by the administration of pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Dissolution of the germinal vesicle (GVBD) occurred in oocytes at 3 hr after hCG administration. Partial expansion of the cumulus cell investment was observed in the cumulus-oocyte complexes, especially those with the oocytes having undergone GVBD. Cumulus expansion due to the deposition of intercellular materials stained with colloidal iron proceeded up to 8 hr after hCG administration. The number of cells in the follicles containing matured oocytes is smaller than that in the follicles containing intact germinal vesicles in the granulosa cell layer, which indicates that the dispersion of cells occurs during meiotic maturation not only in the cumulus-oocyte complexes but also in the granulosa cell layer. Examination of the expansion of mouse cumulus-oocyte complexes by electron microscopy revealed the abundant deposition of intercellular materials and the retraction of the cytoplasmic processes joining the cumulus cells to the oocyte at 3 hr after hCG administration.

Animals↗
PubMed1990

Suppression of spontaneous maturation of isolated cumulus-free mouse oocytes by a calmodulin antagonist.

Oocytes isolated from antral follicles undergo spontaneous maturation when cultured in vitro. W7, a calmodulin antagonist, at concentration of more than 50 microM blocked the occurrence of spontaneous germinal vesicle breakdown (GVBD) in isolated cumulus-free mouse oocytes. The inhibition of maturation was observed in more than 90% of oocytes when W7 was added within 15 min after the initiation of incubation of the oocytes. The block was partially reversible. Hypoxanthine, estradiol-17 beta, testosterone and progesterone did not influence the inhibition induced with W7. The present results suggest that calmodulin is involved in the early stage of mouse oocyte maturation.

Animals↗
PubMed1990

Mouse ovarian factors with angiogenic activities: partial characterization.

Extracts of nonluteal mouse ovaries (Jcl: ICR strain) were assayed for neovascularization by implanting Elvax films, impregnated with test samples, on the lateral wall of the sheath of m. rectus abdominis in young adult mice of the same strain. Neovascularization occurred in a dose-dependent manner. Angiogenic activity was increased in extracts of ovaries from mice treated with follicle-stimulating hormone (FSH). The angiogenic activity was retained when the extract was heated to 100 degrees C for 15 min or adsorbed with activated charcoal. The ovarian extract was purified by affinity chromatography on a Con A-Sepharose 4B column. The adsorbed fraction possessed higher angiogenic activity. The ovarian extract was fractionated by ammonium sulfate precipitation. High angiogenic activity was found in the fraction collected between 20 to 50% saturation.

Animals↗
PubMed1990

Meiotic maturation of bovine oocytes in vitro: improvement of meiotic competence by dibutyryl cyclic adenosine 3',5'-monophosphate.

The present study was undertaken to determine the precise stage of growth at which the ability to resume meiosis is acquired in bovine oocytes. Oocytes of various sizes were isolated from ovaries by mechanical dissection using an 18-gauge needle followed by a razor blade. This method yielded an average of 26.2 +/- 7.4 growing and fully grown oocytes from an ovary. Cumulus-enclosed oocytes were cultured in vitro in tissue culture medium 199 containing 10% fetal calf serum. Oocytes less than or equal to 90 microns in diameter did not resume meiosis. However, germinal vesicle breakdown was observed in oocytes whose diameters exceeded 91 microns. Polar body formation was observed in oocytes with diameters exceeding 101 microns. About 80% of the oocytes with diameters greater than or equal to 121 microns were able to extrude the polar body. The percentage of large oocytes (101 to 120 microns) with first polar body increased when incubated in medium containing dibutyryl cyclic adenosine 3',5'-monophosphate; however, oocytes 90 to 101 microns did not extrude the first polar body even when cultured in a medium containing dibutyryl cyclic adenosine 3',5'-monophosphate. These observations indicate that the capability to resume meiosis is acquired gradually during development of oocytes and that dibutyryl cyclic adenosine 3',5'-monophosphate can improve the meiotic competence of bovine oocytes in culture.

Animals↗
PubMed1990

Pathoepidemiological features of adult T-cell lymphoma/leukemia in an endemic area: Kagoshima, Japan.

In order to elucidate the pathological and epidemiological features of malignant lymphoma (ML), particularly of adult T-cell lymphoma/leukemia (ATLL) in the Kagoshima district, age-adjusted and age-specific incidence rates of malignant lymphomas were estimated on 3239 histologically confirmed cases between the years 1963 and 1987. There was a marked increase in the incidence rate from 1976 (4.9) to 1982 (8.5) due to the increase of T-cell lymphomas. The increase was not conspicuous after 1982. Immunohistochemically, all of the 429 MLs found in 1985 and 1986 were examined on paraffin sections and 70 ATLL cases on fresh frozen sections. T-cell ML comprised 65.3%, B-cell ML 30.5%, Hodgkin disease 2.6%, and histiocytic ML 1.2%. Most of ATLL cells were phenotypically CD4+ CD8-, 14% of ATLL cases showed CD4+ CD8+, 6% were CD4- CD8+, and 7% were CD4- CD8-. The simulataneous expression of IL 2 and IL 2R was seen in 8 (16%) out of 56 patients examined. Therefore, a proliferation by autocrine mechanism does not seem to be a major course of ATLL progression.

Age Factors↗
PubMed1990

[Intraoperative ABR monitoring during cerebello-pontine angle surgery].

Intraoperative auditory brainstem response (ABR) monitoring was performed in 27 patients undergoing C-P angle surgery (12: hemifacial spasm, 10: trigeminal neuralgia, 2: glossopharyngeal neuralgia, 3: C-P angle tumor, 2 epidermoid, 1 meningioma). Because of the introduction of this method, no patient suffered from postoperative hearing disturbance in this series. During C-P angle surgery, the wave V of ABR changes according to the retraction of the cerebellum and the manipulation of the eighth cranial nerve. Many authors have discussed this change, however the timing and the mechanism of disappearance of wave V is unclear. Accordingly, the authors discussed the correlation between the prolongation of wave V latency and its amplitude. The wave V amplitude was measured from the positive peak of wave V to the next negative peak. Then, the correlation between the prolongation of wave V latency and its reduction ratio (%) of amplitude was represented as a parabola. The wave V reduces its amplitude when the prolongation of the latency is from 1.5 ms to 2.0 ms. Once the prolongation of the latency is over 1.5 ms, the amplitude of wave V seems to be reduced suddenly, because it takes over 1'30'' to finish each record. But the authors demonstrated the gradual reduction of the amplitude of wave V in Figure 3. As mentioned above, the prolongation of wave V latency must be less than 1.5 ms, and the neurosurgeon must recognize this turning point during C-P angle surgery.

Cerebellopontine Angle↗