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Biomedical subjects

O Tanaka

Publications and source records attributed to O Tanaka.

At least 253 records · Page 14Linked to original sources
PubMed1987

High-performance liquid chromatography of glycosides on a new type of hydroxyapatite column.

High-performance liquid chromatography on a column of newly developed hard spherical hydroxyapatite was applied to the separation of a variety of glycosides of tri- and diterpenes including Ginseng saponins and Stevia sweet glycosides, affording satisfactory results by using a simple solvent system, aqueous acetonitrile. This normal phase chromatography is superior to chromatography on a silica gel column for the separation of water-soluble glycosides.

Chromatography, High Pressure Liquid↗
PubMed1987

Fourth ventricular floor in human embryos: scanning electron microscopic observations.

The ultrastructural surface features of the normal fourth ventricular floor of seven human embryos ranging from Carnegie stage 14 to stage 19 (crown-rump length: 7.6-16.2 mm) were examined by using scanning electron microscopy (SEM). Low-power SEM views showed the median sulcus, sulcus limitans, and neuromeres, transient structures characteristic of the earlier embryonic period. High-power SEM observation revealed supraependymal cells (SE cells) and supraependymal fibers (SE fibers) which exhibited a characteristic localization, as well as generalized surface-membrane modifications such as microvilli and cilia. SE cells could be classified into two major groups. The type 1 SE cells seem to possess neuronal functions, as deduced from morphological similarities to their counterparts in adults and the specialized distribution closely related to neuromeres. The type 2 SE cell morphologically resembled the phagocytic SE cell described in related literature. SE fibers ran a course either rostrocaudally in the median sulcus or mediolaterally on the neuromeres, most frequently near the interneuromeric cleft; they made contact with type 1 SE cells and ependymal surface modifications and then penetrated the ependymal layer.

Cerebral Ventricles↗
PubMed1986

Immunohistochemical localization of gamma-enolase in early human embryos.

gamma-Enolase has been believed to be distributed only in the neurons and it was frequently labelled as neuron-specific enolase. However, recent precise studies have suggested a wider distribution of the protein. It can also be found in neuroendocrine cells, some mesodermal tissues, and some malignant tumors originating from tissues without the antigen in a normal condition. In early rat embryos, before the formation of neural tissues, a sensitive immunoassay system revealed a substantial amount of gamma-enolase, though it is not yet clear where the antigen is located. In the present study, tissue distribution of gamma-enolase in early human embryos was studied using an immunohistochemical method and it was suggested that the protein is present not only in neural tissue primordium but also in most tissues in the youngest embryo of 6.3 mm crown-rump length. Many of the immunoreactive non-neural tissues, however, lost immunoreactivity with the advancement of the embryonic stage while neural tissues became more intensely stained. In the embryo of 24 mm length, the staining pattern was almost the same as that of reported adult men. In embryonic tissues such as notochord and mesonephros, which disappear in the due course of growth, the antigen was also found. These findings will suggest that the antigen is rather common in undifferentiated tissues but then localizes in neural elements with advancing age. Our findings may be useful in explaining why early rat embryos, before the formation of neural tissues, showed a considerable amount of gamma-enolase and why many undifferentiated tumors, originating from tissues which did not have the antigen in normal condition, revealed the antigen.

Embryo, Mammalian↗
PubMed1986

Amniogenic band anomalies in a fifth-month fetus and in a newborn from maternal oophorectomy during early pregnancy.

A fifth-month fetus and a newborn with amniogenic band anomalies were examined at autopsy. Both specimens were obtained from women who had undergone oophorectomy during early pregnancy. The dead male fetus was aborted spontaneously, and had a micrognathia, a right club foot, and a constriction ring on the left lower leg. The left fingers 2, 3, and 4 were attached to the placenta by a fibrous string. No internal anomaly was noted. In the other case, a male newborn was delivered at the 39th week of gestation and had an agenesis of the calvarium, a cleft lip with palate, an amputation of the right toe, and constriction rings on right fingers 3 and 4 and left finger 3. The placenta was attached to the left temporooccipital region of the head by a fibrous string. Also present was an atrial septum defect and a horseshoe kidney. Possible etiology is discussed in relation to the "amniogenic bands" hypotheses.

Abnormalities, Multiple↗
PubMed1986

A case of single umbilical artery with various fetal anomalies: correlations between prenatal ultrasonographic diagnosis and autopsy.

We report a case of a single umbilical artery with various fetal anomalies, and a comparative study between prenatal ultrasonographic diagnosis and autopsy was done. The prenatal ultrasonographic diagnosis included, atrial septal defect (ASD), ventricular septal defect (VSD), mitral atresia or stenosis and a single great vessel. At autopsy, ASD, VSD, mitral atresia, overriding aorta and pulmonary atresia were evident. In case of other anomalies, the findings in the prenatal diagnosis and at autopsy were encephalocele, adrenal hypoplasia and a single umbilical artery. The ultrasonic detection of these anomalies is discussed and the limitations of this diagnostic method are given attention.

Abnormalities, Multiple↗
PubMed1986

Tortuous vertebral artery simulating extradural spinal tumour.

A rare case of cervical bone erosion resulting from pressure exerted by a congenital tortuous vertebral artery is presented with seven additional cases from the literature. The 3-4 level, especially on the left side, has been the most commonly affected site. The importance of the knowledge of this entity lies in the fact that it causes a surgically treatable radiculopathy, and also that this condition could easily be mistaken for a tumour, leading to accidental bleeding if carelessly approached.

Adult↗
PubMed1986

One-lung ventilation. The effect of positive end expiratory pressure to the nondependent and dependent lung.

We applied positive end expiratory pressure to the nondependent, nonventilated lung, or both nondependent and dependent, ventilated lung during one lung anaesthesia, and compared the results to those obtained by other techniques, such as increasing the inspired oxygen concentration in the dependent lung, or insufflating with oxygen using positive end expiratory pressure in the nondependent lung. Our study suggests that arterial oxygenation and intrapulmonary shunt can be lessened during one lung ventilation by continuous oxygen insufflation of the nondependent lung at 0.98 kPa positive end expiratory pressure while the dependent lung is ventilated with 0.49 kPa positive end expiratory pressure.

Aged↗
PubMed1986

Enhanced small intestinal absorption of beta-lactam antibiotics in rats in the presence of monodesmosides isolated from pericarps of Sapindus mukurossi (Enmei-hi).

Monodesmoside, saponin A, B and C, isolated from pericarps of Sapindus mukurossi (Enmei-hi) have been shown to promote absorption of poorly absorbed beta-lactam antibiotics by the small intestine using an in situ loop method. Monodesmosides were solubilized with ginseng crude saponin extract, a mixture of bisdesmosides, saponin X, Y1 and Y2 which were isolated also from Sapindus mukurossi. These solubilizing agents were demonstrated not to influence the absorption promoting effect of monodesmosides. Among the monodesmosides, saponin B showed the greatest effect. No influence of osmolarity of the administered solution on the absorption promoting action was observed. The promoting functions of the three monodesmosides for the small intestinal absorption of antibiotics were suppressed by Ca2+ ion coexisting in the administered solution.

Animals↗