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Biomedical subjects

T Kawase

Publications and source records attributed to T Kawase.

At least 235 records · Page 13Linked to original sources
PubMed1989

Lipid peroxidation and antioxidant defense systems in rat liver after chronic ethanol feeding.

The effects of chronic ethanol feeding on hepatic lipid peroxidation, ascorbic acid, glutathione and vitamin E levels were investigated in rats fed low or adequate amounts of dietary vitamin E. Hepatic lipid peroxidation was significantly increased after chronic ethanol feeding in rats receiving a low-vitamin E diet, indicating that dietary vitamin E is an important determinant of hepatic lipid peroxidation induced by chronic ethanol feeding. No significant change was observed in hepatic non-heme iron content, but hepatic content of ascorbic acid and glutathione was increased by ethanol feeding. Both low dietary vitamin E and ethanol feeding significantly reduced hepatic alpha-tocopherol content, and the lowest hepatic alpha-tocopherol was found in rats receiving a combination of low vitamin E and ethanol. Plasma alpha-tocopherol was elevated after ethanol feeding, probably because of the associated hyperlipemia. Both the ratio of plasma alpha-tocopherol/plasma lipid and the red blood cell alpha-tocopherol were reduced by ethanol feeding. Furthermore, ethanol feeding caused a marked increase of hepatic alpha-tocopheryl quinone, a metabolite of alpha-tocopherol by free radical reactions. Ethanol feeding caused little changes of alpha-tocopherol and alpha-tocopheryl quinone content in mitochondria, whereas a striking increase in alpha-tocopheryl quinone was observed in microsomes. These data suggest that ethanol feeding causes a marked alteration of vitamin E metabolism in the liver and that the combination of ethanol with a low-vitamin E intake results in a decrease of hepatic alpha-tocopherol content which renders the liver more susceptible to free radical attack.

Animals↗
PubMed1989

Identification of osteoblast-specific monoclonal antibodies.

A series of four antibodies against rat osteoblasts have been produced using the hybridoma technique. After bone cells isolated from newborn rat calvariae by a sequential digestion procedure were cultured for 3 days, the cells were trypsinized and further maintained in rotation cultures overnight. Out of the cultured bone cells alkaline phosphatase-positive cells were sorted by flow cytometry and used as immunogens. The clones secreting the antibodies were selected on the basis of the abilities of these antibodies to bind to the bone cells but not to fibroblasts from neonatal rat head skins, in an enzyme-linked immunosorbent assay. Clones of two hybridomas, designated AOB-1 and AOB-2, were used to characterize the antigenic determinant(s) in osteogenic cells. The antibody showed the reactivity with isolated alkaline phosphatase-positive cells, osteogenic tissue cells in newborn rat calvaria, and mandibula, but not with the cells in head skin, lung, kidney, liver, or stomach as determined by immunofluorescence study. Western blot analysis has identified the antigenic determinants possessing apparent molecular weights of 210,000, 110,000, 65,000, 58,000, 40,000, 36,000, 32,000, 28,000, 25,000, 17,000, and 15,000 of osteoblast-rich monolayer cultured cells. According to the cell surface detection with biotin-avidin protein blotting technique, these fractions appear to be present as components of the cell surface of the osteoblast.

Animals↗
PubMed1989

Studies on the transmembrane migration of fluoride and its effects on proliferation of L-929 fibroblasts (L cells) in vitro.

A decrease in the pH of the medium facilitated fluoride (F-) influx but depressed its efflux, which is consistent with the hypothesis that simple diffusion of hydrogen fluoride (HF) contributes to F- migration across the cell membrane. Long-term exposure to F- (greater than 1 mM) induced F- accumulation and, as a result, inhibited cell proliferation. In contrast, short-term exposure to F- (greater than 1 mM), followed by careful washing, did not inhibit cell proliferation but rather stimulated it. Moreover, this stimulatory effect was enhanced by 1 microM Al3+ and was inhibited by 1 microM H-7, a specific inhibitor of protein kinase C. Thus F- may stimulate cell proliferation by activating protein kinase C through GTP-binding protein. The stimulatory effect of F- on cell proliferation, which is usually hidden by its inhibitory effect, can be observed by preventing the accumulation of F- in the cytoplasm.

Animals↗
PubMed1989

Radical surgery of a galenic aneurysm with regional cerebral blood flow analysis. A case report.

Successful surgical treatment of a case of aneurysm of the vein of Galen is presented. An 11-month-old boy was admitted with episodes of convulsive attacks. Neuroradiological examination revealed an aneurysm of the vein of Galen filled by branches of posterior cerebral arteries and left thalamoperforating artery. Regional cerebral blood flow, which was measured by a method of xenon-enhanced computed tomography, showed a low flow area in the frontal and occipital regions. The aneurysm was approached through the bilateral parietooccipital interhemisphere, freed from the feeders, and ligated. During the operation, cortical blood flow was monitored for prevention of normal perfusion pressure breakthrough. After the feeders were successfully clipped, the blood flow increased and became normalized in the related cortex. There was no postoperative neurological deterioration.

Arteriovenous Fistula↗
PubMed1989

Aluminum enhances the stimulatory effect of NaF on prostaglandin E2 synthesis in a clonal osteoblast-like cell line, MOB 3-4, in vitro.

The effect of NaF on prostaglandin E2 (PGE2) synthesis in a clonal osteoblast-like cell line, MOB 3-4, was examined in the presence of Al3+. The MOB 3-4 cell line, which was derived from neonatal mouse calvaria, displays many osteoblastic characteristics, including the biosynthesis of PGE2. In the absence of Al3+, 1 mM NaF increased PGE2 synthesis (per well) to about 340% of the control level, whereas NaF at lower concentrations (below 0.1 mM) did not show such a significant effect. In the presence of 10 microM Al3+, NaF concentrations ranging from 0.01 to 1 mM increased PGE2 synthesis in a dose-dependent manner, though 10 microM Al3+ had no effect by itself. Similar effects were observed on alkaline phosphatase (ALP) activity per well, but a stimulatory effect of NaF on protein synthesis was observed only in the presence of 10 microM Al3+. These data demonstrated that PGE2 synthesis per protein was increased by NaF alone, and this effect was markedly enhanced by the addition of AlCl3. ALP activity per protein was, however, significantly increased by NaF in the absence of AlCl3. Taken together with our previous finding that Al3+ enhances the NaF-induced Ca2+ mobilization in MOB 3-4 cells, these results suggest that F- combined with Al3+ (i.e., AlF4-) is a more potent stimulator of PGE2 synthesis in cells than F- alone, and that the AlF4- -enhanced PGE2 synthesis may be caused by an increase in cytosolic free Ca2+ concentration during activation of the G protein by AlF4-.

Alkaline Phosphatase↗
PubMed1989

Fluoride-induced cytoplasmic acidification: possible role of protein kinase C in BCECF-loaded L929 cells.

The effect of fluoride on cytoplasmic pH (pHi) in L929 cells was investigated by using a fluorescent pH indicator, BCECF. Fluoride decreased pHi in a dose-dependent manner. This cytoplasmic acidification was composed of two phases: 1) a rapid decrease in pHi occurring within seconds, and 2) a slow decrease in pHi occurring 1-2 min. after stimulation with fluoride. The phase one decrease in pHi at external pH (pHe) 7.7 was more rapid than that at pHe 6.8, whereas the phase two decrease at pHe 7.7 was slower than that at pHe 6.8. In addition, both in the protein kinase C-inhibited and depleted cells, the fluoride-acidified pHi gradually returned to the resting pHi level in phase two, though the initial cytoplasmic acidification (i.e. phase one) was not affected. These results suggest that the fluoride-induced cytoplasmic acidification is dependent upon pHe and is sustained by the protein kinase C-dependent Na+/H+ exchange.

Cytoplasm↗
PubMed1989

Effect of external auditory canal pressure upon the hearing threshold in patients with Menière's disease.

Fluctuation of hearing at low frequencies is one of the most characteristic findings in Meniere's disease and seems to be a phenomenon closely related to changes of endolymphatic pressure and volume. In the present study, pressure was applied to the external auditory canal of patients with Meniere's disease, and the effect on the bone conduction threshold was examined at times of depressed and improved hearing. In more than half of these cases, it was found that the pressure effect was marked at the time of improved hearing acuity, but not at the time of depressed hearing. This effect was also confirmed in more objective experiments with guinea pigs. It is concluded that the fluctuation of hearing in Meniere's disease seems to be a phenomenon accompanying the endolymphatic pressure change in the scala media.

Animals↗
PubMed1989

[Gellé test in patients of Menière's disease and fluctuating low tone hearing loss].

The threshold shift at 500 Hz bone conduction under positive and negative static pressure of 400 mmH2O applied to the external auditory canal was examined in 20 patients of Meniere's disease with fluctuating low tone hearing loss, 21 patients of sensorineural hearing loss without fluctuating and 24 normal controls. In contrast to the 10 to 15 dB threshold shift in the latter two groups (non-fluctuating group, 14.8 +/- 5.1 dB at positive and 11.1 +/- 5.7 dB at negative; normal controls, 13.6 +/- 5.4 dB at positive and 9.3 +/- 5.3 dB at negative), the former showed a significantly smaller shift (3.2 +/- 6.1 dB at positive and 2.3 +/- 4.5 dB at negative) while hearing was depressed. However, when the hearing was improved, the pressure effect became greater even in the former group (11.3 +/- 5.3 dB at positive and 9.1 +/- 4.8 dB at negative). To understand further details of these phenomena, we performed electrophysiological animal experiments. Through a small hole made on the guinea pig's cochlear bony wall, 300 mmH2O pressure was applied to the scala tympani and the threshold of 500 Hz CM was examined in both endolymphatic sac obliterated ears and non-obliterated ears. In 14 non-obliterated ears 21.1 +/- 5.1 dB threshold shift was recorded, whereas it was only 1.6 +/- 2.6 dB in 9 obliterated ears at 4-6th postoperative days. These results seem to reflect that the endolymphatic pressure is great during the early stage of hydrops.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Crossed cerebellar diaschisis in hydrocephalus--a case report].

A case of hydrocephalus in which a crossed cerebellar diaschisis with single photon emission CT (SPECT) using 123I-iodoamphetamine (123I-IMP) disappeared by a ventriculo-peritoneal shunting operation, was reported. A 54-year-old female had a clipping surgery for a aneurysm of the left middle cerebral artery on April 9, 1987. Post-operatively, she had a transient mild aphasia. Cerebral blood flow (CBF) study with 123I-IMP-SPECT had showed low perfusion in the left frontal and temporal lobe. But after a month, clinical symptom and CBF findings had improved. She had been doing well after the discharge until October, 1987, when she developed disorientation. CT on re-admission showed the ventricular dilatation with periventricular low density (left greater than right). 123I-IMP-SPECT study showed the crossed cerebellar diaschisis which was a low perfusion in the left frontal, temporal, parietal, thalamus, basal ganglionic area and in the opposite cerebellum. A ventriculo-peritoneal shunting operation was performed which brought the disappearance of the crossed cerebellar diaschisis and the clinical improvement. The phenomenon of crossed cerebellar diaschisis has been reported in a lot of literatures. However, those diseases were located in unilateral supratentorium. It has been speculated that crossed cerebellar diaschisis is the transneural metabolic change through the cortico-ponto-cerebellar pathway by supratentorial lesion. Crossed cerebellar diaschisis in hydrocephalus has not been reported so far.(ABSTRACT TRUNCATED AT 250 WORDS)

Amphetamines↗
PubMed1989

[A case of abdominal actinomycosis following foreign body in the stomach wall].

Recently abdominal actinomycosis is rare. Its diagnosis is difficult because it resembles malignant diseases. We reported a case of abdominal actinomycosis considered to be of the stomach origin and attempted to correlate the radiological findings with the pathological features referring to the previous reports.

Actinomycosis↗
PubMed1989

Labyrinthine fistulae caused by cholesteatoma. Improved bone conduction by treatment.

In five cases of labyrinthine fistulae caused by extensive cholesteatoma, more than 30-dB improvement in bone conduction was observed in four postoperative cases and in one case after preoperative administration of antibiotics. In each case, a fistula of more than 2 mm in length was present at the lateral semicircular canal, and membranous labyrinthine wall was exposed when the cholesteatoma membrane was removed. These five cases were considered to be in the stage of serous labyrinthitis. The experience with these cases shows that emergent antibiotic treatment and surgery are appropriate for cases with reduced bone conduction in which labyrinthine fistula caused by cholesteatoma is suspected. In addition, as the reduction of bone conduction does not necessarily preclude the possibility of good postoperative hearing, tympanoplasty may be appropriate even for cases with markedly reduced bone conduction due to labyrinthine fistulae.

Adolescent↗
PubMed1989

[Xenon-enhanced CT CBF measurements in intracranial vascular malformations].

In the management of intracranial vascular malformations, it is important to know the regional cerebral blood flow in its surrounding structure. However, CT scan with contrast medium and angiography have only a limited ability to estimate the rCBF. In this study, stable xenon-computerized tomography scanning by means of the end-tidal gas-sampling method was performed in eleven patients with intracranial vascular malformations. Seven of the patients had arteriovenous malformations, three had venous angiomas and one had aneurysm of the vein of Galen. In two patients with large arteriovenous malformations, in two with "larger" venous angioma and in one with aneurysm of the vein of Galen, rCBF values were significantly reduced, particularly adjacent to the malformations. In contrast, there were no areas showing reduced rCBF in cases where the malformations were small. This indicates development of ischemia correlates with the size of malformations. From the xenon-enhanced CT scan and angiographic findings, the presence of steal phenomenon with venous congestion might be a cause of rCBF reduction in those cases where ischemia exists.

Adolescent↗
PubMed1988

NaF-induced Ca2+ mobilization is dependent upon the culture density in a parathyroid hormone-responsive osteoblast-like cell line.

The effect of NaF on cytosolic free Ca2+ concentrations [( Ca2+]i) was examined in a clonal osteoblast-like cell line (MOB 3-4) loaded with Fura 2. MOB 3-4 cells in a sparse culture, which exhibited neither alkaline phosphatase (ALP) activity nor the response to parathyroid hormone (PTH), responded to NaF (0.1-10 mM) to increase [Ca2+]i transiently. In contrast, the cells in a dense culture, which exhibited both ALP activity and the response to PTH, responded to NaF (above 4 mM) to increase [Ca2+]i slowly. [Ca2+]i in osteoblasts in primary culture slowly increased in response to both NaF (above 4 mM) and PTH (3 U/ml). Thus, the sensitivity and the response of MOB 3-4 cells to NaF and PTH varied with the culture density, and high culture density matured the cells like osteoblasts in primary culture. These NaF-induced Ca2+ mobilizations were not dependent upon external Ca2+ and were enhanced by Al3+ (1 microM), whereas the PTH-induced Ca2+ mobilizations were due to Ca2+ influx. These results suggest that the maturation of MOB 3-4 cells, dependent upon the culture density, modulates intracellular signal transduction pathways and thereby alters the NaF-induced Ca2+ mobilization, and that the culture density must be taken into consideration in studying Ca2+ mobilization in such an osteoblast-like cells line as MOB 3-4 cell line.

Animals↗
PubMed1988

The calcium-mobilizing action of low concentrations of sodium fluoride in single fibroblasts.

The sensitivity of fibroblasts (L cells) to low concentrations of sodium fluoride (NaF) was examined using the same cell during a series of stimuli. NaF with increasing concentrations up to 1 mM elevated cytosolic free Ca2+ concentrations ([Ca2+]i) in single cells. [Ca2+]i increased within 15 sec of addition of NaF and lowered to basal [Ca2+]i levels quickly. This elevation was observed both in the presence and absence of external Ca2+ and was enhanced by 1 microM Al3+. These results suggest that low concentrations (below 1 mM) of NaF induce Ca2+ release from intracellular Ca2+ stores in single L cells through guanine nucleotide-binding protein (G protein).

Aluminum↗
PubMed1988

Phosphatidic acid-induced calcium mobilization in osteoblasts.

Phosphatidic acid (PA) evoked a transient increase in the cytosolic free Ca2+ concentration ([Ca2+]i) in osteoblasts isolated from neonatal mouse calvaria. This increase was observed in both low (below 150 microM) and high (1.26 mM) Ca2+-containing medium. In contrast, other phospholipids, such as phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol, failed to increase [Ca2+]i in osteoblasts. In high Ca2+-containing medium, A23187 also increased [Ca2+]i in the cells, but the mode of the change was different from that in the case of PA. These results suggest that PA may induce Ca2+-mediated cellular responses through Ca2+ release from intracellular stores in osteoblasts.

Animals↗
PubMed1988

Relation of prognosis of peripheral facial nerve palsy to the period between onset of illness and date of denervation.

The presence or absence of the denervation is one of the important factors to determine the prognosis of peripheral facial nerve palsy and it is generally accepted that the denervation becomes apparent within 2 weeks from the onset of illness. In the present study, 62 cases with denervation in which nerve excitability test (NET) was possible within 1 week from the onset of illness were selected for analysis. Although 47 cases exhibited the denervation within 2 weeks, it was first detected after 2 weeks in other 15. Although the prognosis was far better in the latter group, 2 cases exhibited the unfavorable recovery. These results indicate the importance of NET even 2 weeks after the onset of illness.

Denervation↗
PubMed1988

[Biochemical characterization of phenytoin-induced hyperplastic human gingival fibroblasts. Non-collagenous proteins biosynthesis].

Phenytoin (PHT), administered as an anticonvulsant, has a side effect gingiva overgrowth in approximately 50% of patients. The present study was attempted to explore the biochemical mechanism on non-collagenous protein biosynthesis as affected by PHT. Responder cells (RES A3, RES C2) of a patient with gingival overgrowth were obtained by the method of Kawase et al. Normal human gingival fibroblasts (Gin-1), purchased from ATCC, were also used. All cells were inoculated at 1 x 10(4) cells/cm2 (12 multi-well plate or 60 mm tissue culture dish), and then cultured for 4, 8 and 12 days with or without PHT (5 micrograms/ml). Prior to harvesting at the indicated times, cells were incubated with 14C-amino acids (1.25 microCi/ml) for 24 hours. The 14C-labeled proteins were isolated from the cell layers including extracellular matrix, following Kurkinen et al. with a minor change. Each 14C-labeled fraction was dissolved in 3 ml of Aquasol-2 and the radioactivity by a liquid scintillation counter. The DNA content of cell layers affected by PHT was increased on Gin-1, RES A3 and RES C2 at the post-confluence, resulting also in an increase in cell number. Two morphologically different phenotypes of responder cells were observed, differing in nuclear and cell sizes. At 12 days culture, RES A3, were stimulated by PHT, showed increased synthesis of both total extractable proteins (EP) and binding proteins (BP) labeled with 14C-amino acids. Therefore, at least two distinct phenotypic responder cells are present in the PHT-induced overgrowth gingiva, alter the synthesis of non-collagenous proteins.

Fibroblasts↗