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Biomedical subjects

Y Takei

Publications and source records attributed to Y Takei.

At least 343 records · Page 19Linked to original sources
PubMed1985

Symptomatic Rathke's cleft cysts located entirely in the suprasellar region: review of diagnosis, management, and pathogenesis.

Three cases of an entirely suprasellar symptomatic Rathke's cleft cyst, two of which were associated with normal sella turcicas, are reported. In all cases, the cysts caused compression of the optic chiasm, and two produced hypothalamic dysfunction. The diagnosis of these entirely suprasellar masses was enhanced by metrizamide cisternography. Two cases were treated by frontal craniotomy and one was treated transsphenoidally, with good results in all cases. The radiology, pathology, and surgical treatment of these unusual cases is presented. An embryological pathogenesis for the occurrence of an entirely suprasellar Rathke's cleft cyst is discussed.

Adolescent↗
PubMed1984

Immunocytochemical identification of CRF in the human hypothalamus.

Immunoreactive ovine corticotropin-releasing factor (CRF) was revealed in the cell bodies of parvocellular neurons in the paraventricular nucleus of the human hypothalamus by an immunocytochemical technique. The immunoreactivity was negative in magnocellular neurons. Immunoreactive nerve fibers were found in the subependymal layers of the third ventricle and in the perivascular space of the primary plexus in the lower hypothalamus. No CRF immunoreactive cell bodies were found in the supraoptic nucleus.

Corticotropin-Releasing Hormone↗
PubMed1984

Mechanisms of adverse effect of air-oxidized soy bean oil-feeding in rats.

In order to clarify the mechanism of the adverse effects of air-oxidized oil feeding, the effects of dietary soy bean oil on body weight gain, food consumption, fecal consistency and gastrointestinal functions were investigated in rats. Feeding of oxidized soy bean oil with a peroxide value above 350 produced significant reductions in body weight gain, food consumption and intestinal sucrase activity, and severe diarrhea. These adverse effects were prevented with the concurrent feeding of Gobo dietary fiber and were rapidly eliminated within a day after switching to the diet containing the unoxidized soy bean oil. Furthermore, the remarkable release of sucrase from the small intestine was observed on perfusion of the jejunum with Ringer's bicarbonate solution containing the oxidized soy bean oil at the 1% level. These findings suggest that the adverse effects occurring after air-oxidized oil feeding are due to a disturbance of gastrointestinal functions, and raise the possibility that the primary cause might be solubilization or exfoliation of the brush border membrane.

Air↗
PubMed1984

Photobinding of 3H 8-methoxypsoralen to monkey intraocular tissues.

Young (less than 1 year) and old (greater than 15 years) Rhesus monkeys were utilized in this study in order to determine whether ultraviolet (UV) radiation at ambient levels induces psoralen photobinding in primate eyes (in particular the lens and retina). Unilateral aphakia or pseudophakia was induced surgically and the eyes were allowed to heal. The animals then were given a single intraperitoneal injection of 3H 8-methoxypsoralen (8-MOP) and immediately exposed to BLB lights (of measured radiation intensity at the corneal surface). The animals were killed at varying time periods (2-6 weeks), and the eyes were removed immediately. One-half of each cornea and lens was frozen for subsequent optical spectroscopy and the remaining ocular tissues were fixed for histopathologic studies and autoradiography. These data demonstrate that low level UV radiation (less than 0.4 mW/cm2) can cause 8-MOP photobinding to lens proteins and DNA and to aphakic, pseudophakic, and young phakic primate retinas. The older phakic primate lens serves as a protective UV filter and prevents psoralen photobinding within the retina. These data suggest that older aphakes and pseudophakes may require UV radiation protection to prevent direct as well as photosensitized retinal photodamage.

Animals↗
PubMed1983

Drinking induced by angiotensin II in fishes.

Among 20 species of freshwater fishes examined, Pseudorasbora parva, Rhodeus ocellatus, Cobitis anguillicaudatus, Carassius auratus, Oryzias latipes, Gambusia affinis, and Gyrinocheilus anymonieri were found to drink water like seawater fishes, while 13 remaining species did not drink. For fish species found exclusively in fresh water, angiotensin II (AII) treatment did not induce drinking. In contrast, those freshwater fishes which survive in estuarine brackish water (Leuciscus hakonensis, C. carassius, Parasilurus asotus, G. affinis, Chaenogobius annularis, Tridentiger obscurus, and G. anymonieri responded to AII by drinking. Furthermore, some freshwater fishes which survive either in hypertonic water (C. auratus) or in sea water (Anguilla japonica and O. latipes) also responded to AII by drinking. Of 17 seawater fishes examined, Eptatretus burgeri, Triakis scyllia, and Heterodontus japonicus failed to drink water, and for Trachurus japonicus, Platichthys bicoloratus, and Glossogobius giuris fasciatopunctatus, water intake was minor (similar to freshwater fishes). The 11 remaining seawater fishes drank water. AII did not induce drinking in fishes living exclusively in sea water. However, seawater fishes which survive either in tide pools (Chasmichthys dolichognathus gulosus) or in brackish water (Sillago japonica, Mugil cephalus, G. giuris fasciatopunctatus) responded to AII by drinking. P. bicoloratus, Acanthopagrus schlegeli, and Fugu niphobles were exceptional, in that they survive in brackish water, but did not respond to AII. Although some exceptions exist, it is generally concluded that a drinking response to AII is characteristic of fishes which encounter water more hypertonic than that in which they typically reside. Accordingly, a drinking mechanism induced by AII may be a compensatory emergency reaction to dehydration stress.

Angiotensin II↗
PubMed1982

Mechanisms for induction of drinking with special reference to angiotensin II.

The Japanese quail drinks water vigorously after water deprivation, haemorrhage and administration of hypertonic saline solution. Most avian species responded to angiotensin II (AII) by drinking, but carnivorous birds and those originating in arid regions were insensitive. The receptive sites for AII were the subfornical organ (SFO) and the preoptic area (POA) in the Japanese quail. Catecholaminergic fibers proceed from the POA to the SFO. Dipsogenic information generated by AII at the POA is transferred to the SFO through the catecholaminergic nerve fibres. Plasma AII increased following dehydration and haemorrhage and returned to a normal level immediately after rehydration. Following dehydration, arginine vasotocin, aldosterone and corticosterone increased in plasma as well as AII. A single intraperitoneal injection of AII induced increases of arginine vasotocin, aldosterone and corticosterone in plasma. It seems that AII functions as a trigger for release of these other hormones during dehydration.

Angiotensin II↗
PubMed1982

Herpes simplex virus encephalitis: laboratory evaluations and their diagnostic significance.

Laboratory procedures were compared with brain biopsy findings in 113 biopsy-proven patients with herpes simplex virus (HSV) encephalitis and 93 biopsy-negative individuals. Examinations of brain tissue by histopathology, immunofluorescence, and electron microscopy demonstrated evidence of HSV infection in 56%, 70%, and 45% of proven cases and apparently false-positive results in 14%, 9% and 2% of those biopsy-negative. Serologic assessments revealed that HSV encephalitis occurred as both a primary (30%) and recurrent (70%) infection. Among patients with HSV encephalitis, 28% failed to seroconvert or seroboost within one month of the onset of disease. Titers of passive hemagglutinating and IgG immunofluorescent antibodies increased fourfold in the cerebrospinal fluid in 74% and 94%, respectively, of patients with proven disease. Similar percentages of patients had antibody ratios in serum and cerebrospinal fluid of less than 20 over the same interval. These data indicate the need for development of noninvasive diagnostic procedures.

Adolescent↗
PubMed1982

Supratentorial subarachnoid epithelial cyst: case report and ultrastructural study.

Supratentorial epithelial cysts are rare entities that have evoked controversy regarding their pathogenesis. Recent ultrastructural studies have failed to resolve this controversy. We present a case report and an ultrastructural study of such a cyst. The cyst wall was lined by columnar epithelial cells with prominent cilia and microvilli at their apical surface. They were joined by well-developed junctional complexes and contained abundant intracytoplasmic, electron-dense, granular material, some of which was membrane-bound. These ultrastructural findings suggest that epithelial cysts are derived from elements of the embryological tela choroidea.

Adult↗
PubMed1982

[Pharmacological actions of oxatomide (KW-4354). 3. Actions on experimental asthma and Schultz-Dale reaction].

The present experiment was carried out to elucidate the effectiveness of oxatomide for prophylaxis in the bronchial anaphylaxis and Schultz-Dale response. 1) Oxatomide administered i.v. was found to be as active as disodium cromoglycate (DSCG) in inhibiting IgE-mediated active anaphylactic bronchoconstrictions in rats. In contrast to DSCG, oxatomide was effective when administered p.o. 2) Passive anaphylactic broncho-constrictions in guinea pigs mediated IgG-like rabbit antibody against egg albumin was also prevented dose-dependently by treatment with oxatomide given p.o. and i.v., but not by DSCG. 3) Oxatomide and DSCG inhibited passive anaphylactic bronchoconstrictions in guinea pigs mediated by IgE-like antibody against BPO X BGG. 4) The anaphylactic reaction of the isolated guinea pig ileum, the so-called Schultz-Dale reaction, showed a bi-phasic response: a short, rapid contraction followed by a partial relaxation and a slow contractile response. Oxatomide significantly depressed both the rapid first contraction and the slow sustained one. 5) Oxatomide administered after the development of antigen-induced contraction of isolated guinea pig trachea resulted in relaxation. These results suggest that oxatomide may be effective for the treatment of allergic bronchial asthma.

Animals↗
PubMed1982

[Studies on the therapeutics of experimental toxoplasmosis. II. Effect of acetylspiramycin alone or in combination with an immunopotentiator (CSP-II) or sulfamethopyrazine on Toxoplasma multiplication in the heart of mice acutely and chronically infected with Toxoplasma gondii (author's transl)].

Normal mice acutely and chronically infected with the S-273 strain of T. gondii, were treated with acetylspiramycin (ASPM) alone, 8 mg/mouse/day, per os, or in combination with an immunopotentiator (CSP-II), 10 mg/mouse/day, intraperitoneally, or sulfamethopyrazine (SMPZ), 2 mg/mouse/day, per os, for a period of 4 weeks. In the acute cases, a 99.4% cyst reduction was obtained with ASPM alone and no cysts were seen in the brains of mice treated with ASPM in combination with CSP-II or SMPZ. The organisms were significantly eradicated in the brain and heart tissues of mice treated with ASPM alone or in combination with CSP-II or SMPZ as shown by subinoculation to normal mice and the negative latex hemagglutination titers of the recipient mice. In the chronic cases, a cyst reduction of 52.4% was obtained with mice treated with ASPM in combination with CSP-II. A cyst reduction of 34.6%, 32.9% and 20.8% was obtained in the ASPM alone, CSP-II alone and ASPM in combination with SMPZ treated groups, respectively. A comparative clearing of the organisms in the heart tissues of mice treated with ASPM in combination with CSP-II was obtained compared to the other treatment groups but not in the brains of all groups.

Adjuvants, Immunologic↗
PubMed1982

Hemangioendothelioma of the neuraxis: an ultrastructural study.

Hemangioendotheliomas are vascular tumors that rarely involve the neuraxis. However, when they do, they must be differentiated from the other neoplastic vascular lesions that more commonly involve the central nervous system (CNS). We describe the ultrastructural features of three hemangioendotheliomas of the neuraxis. These lesions are characterized by the proliferation of endothelial cells around vascular lumina and of pericytes outside of the endothelial basal lamina. These features differ from those of other vascular tumors of the CNS. Based on these observations, we consider hemangioendothelioma to be a distinct entity among the neoplasms of vascular origin in the CNS.

Brain Neoplasms↗