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Biomedical subjects

Y Handa

Publications and source records attributed to Y Handa.

At least 199 records · Page 11Linked to original sources
PubMed1985

Long-term survival of functional hepatocytes from adult rat in the presence of phenobarbital in primary culture.

In the presence of phenobarbital (PB) at 3 mM, hepatocytes isolated from adult rats by a collagenase-perfusion technique survived well on plastic dishes for at least 49 days after initiation of primary culture. PB at concentrations less than 3 mM was ineffective for the maintenance of hepatocytes, and the maintenance of them was attained only in the continuous presence of 3 mM PB. The hepatocytes surviving in the presence of 3 mM PB were morphologically indistinguishable from the hepatocytes after 1-day attachment period, except for the presence of prominent nucleoli in the former. Although both the albumin secretion and tyrosine aminotransferase (TAT) activities of the cells decreased gradually up to day 7 with time in culture, both were thereafter maintained at relatively high levels at least up to day 35 of primary culture. The addition of 10 microM dexamethasone caused a 3-5-fold induction in TAT activity, and the cells were capable of responding to the hormone in this manner at least up to day 28 of primary culture. Furthermore, the cells also had glucose-6-phosphatase activity, even though the level of this enzyme activity was relatively low as compared with that of TAT activity. Survival of hepatocytes in the presence of 3 mM PB was further enhanced by simultaneous addition of dexamethasone (10 microM) and insulin (10 micrograms/ml). The sensitivity of hepatocytes to 3'-methyl-4-dimethylaminoazobenzene (0.24 mM) was remarkably reduced by treatment with PB at 3 mM. PB treatment decreased efficiently the falling rate of total cytochrome P-450 content, but did not induce P-450PB, which is the specific form of cytochrome P-450 induced by PB, in primary cultured hepatocytes. On the other hand, 3-methylcholanthrene (MC, 10 microM) caused an increase of both contents of total cytochrome P-450 and P-450MC, which is the specific form of cytochrome P-450 induced by MC, in primary cultured hepatocytes. However, MC was ineffective for the maintenance of hepatocytes in primary culture. The possible biological actions of PB on primary cultured hepatocytes are discussed on the basis of the experimental data obtained.

Albumins↗
PubMed1985

Effects of iodide on thyroid follicle structure and electrophysiological potentials of cultured thyroid cells.

In cultured porcine thyroid cells, exposure to iodide induces morphological and electrophysiological changes in the cells and suppresses the iodine uptake and organification activities of the cells. NaI affects thyroid structures: after exposure to 10(-7), 10(-6), and 10(-5) M NaI, the follicles first lose their typical roundness, and then the numbers of microvilli decrease. NaI (10(-6) and 10(-5) M) decreases the thyroid electrical membrane potentials. NaI induces suppression of iodine uptake and organification: exposure to 10(-6) and 10(-5) M NaI suppresses subsequently determined iodine uptake and organification. This iodide-induced suppression of iodine uptake and organification may be related to the iodide-induced morphological and electrophysiological changes. The iodide-induced changes and suppression of iodide uptake and organification are reversible. They are observed when thyroid cells are cultured in the presence of TSH.

Animals↗
PubMed1985

Transformation of primary cultured and co-cultured adult rat liver cells by 3'-methyl-4-dimethylaminoazobenzene.

Under various conditions of culture and carcinogen treatment, the transformation of liver cells by 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) was studied. Primary liver cell (PLC) cultures from adult male rats and co-cultures with PLCs of ARL-D8 cells of a liver epithelial-like clear cell line from adult female rats were treated with 0.24 mM 3'-Me-DAB for 6 days. Four of 8 carcinogen-treated PLC cultures contained cells with marker chromosomes, and 3 of the 8 cultures contained gamma-glutamyltranspeptidase (GGT)-positive cells. Three of 5 carcinogen-treated co-cultures contained cells with marker chromosomes, and 2 of the 5 co-cultures contained GGT-positive cells. Pure cultures of ARL-D8 cells were treated for 6 or 12 days with 3'-Me-DAB (0.24 mM)-containing-medium perfused through the liver of adult male rats in situ. In the 6-day treatment, none of 5 carcinogen-treated cultures showed chromosomal abnormality or cytochemically exhibited GGT activity. However, in the 12-day treatment, 2 of the 5 carcinogen-treated cultures contained cells with marker chromosomes, and 2 of the 5 cultures contained GGT-positive cells. None of the control cultures exhibited chromosomal abnormality or GGT-positive cells. In summary, transformation markers increased in ARL-D8 cells when they were co-cultured with PLCs.

Animals↗
PubMed1985

ICP patterns and isotope cisternography in patients with communicating hydrocephalus following rupture of intracranial aneurysm.

Intracranial pressure (ICP) was continuously recorded, isotope cisternography was performed, and the ventricular system size was evaluated on serial computerized tomography scans in 39 patients. All of these patients had communicating hydrocephalus after subarachnoid hemorrhage (SAH) from rupture of an intracranial aneurysm. The studies were carried out in both the acute stage (within 7 days after SAH) and the communicating hydrocephalus stage. In patients in the acute stage who had no ventricular dilatation, but who later developed communicating hydrocephalus, the resting ICP was high, and an ICP pattern of B-wave activity was seen; there was no delay in cerebrospinal fluid (CSF) absorption on isotope cisternography. Patients with communicating hydrocephalus in whom ICP recordings were started within 63 days after SAH had a pattern of plateau waves in conjunction with B-waves, and there was a marked delay in CSF circulation. In general, patients with higher resting ICP's had more frequent ICP irregularities. Patients with communicating hydrocephalus in whom recordings were begun more than 6 months after SAH had a low and flat ICP pattern, and there was no delay in CSF absorption in spite of bilateral convexity blocks on isotope cisternography. The results suggest that the ICP pattern of plateau waves in conjunction with B-waves can be regarded as a sign of delayed CSF absorption; hence, shunting procedures may be indicated in patients with plateau waves in conjunction with B-waves visualized on continuous ICP recordings.

Adult↗
PubMed1985

Brain blood volume and blood flow in patients with plateau waves.

Plateau waves, characterized by acute transient rises of the intracranial pressure (ICP), are accompanied by a marked decrease of the cerebral perfusion pressure. Patients with plateau waves, however, often show no clinical symptoms of ischemia of the brain stem, such as vasopressor response or impairment of consciousness during the waves. The authors studied brain blood volume and blood flow with dynamic computerized tomography using rapid-sequence scanning in patients with plateau waves identified during continuous ICP recording. Following an intravenous bolus injection of contrast medium, density-versus-time curves were obtained for the regions of interest; that is, the frontal lobe, the temporal lobe, the caudate nucleus, the putamen, and the pons. The dynamic studies were undertaken when the ICP was high during a plateau-wave phase and when it was low during an interval phase between two plateau waves. The results indicate that, in the cerebral hemisphere (frontal lobe, temporal lobe, caudate nucleus, and putamen), plateau waves were accompanied by an increase in blood volume and, at the same time, a decrease in blood flow. In the pons, however, both the blood volume and blood flow showed little change during plateau waves as compared with the intervals between two plateau waves. These observations may explain why there is no rise in the systemic blood pressure and why patients are often alert during plateau waves.

Adult↗
PubMed1985

[Systemic blood pressure and respiration during plateau wave phenomena].

The intracranial pressure, systemic blood pressure, respiratory pattern and heart rate were studied polygraphically in five patients with plateau waves in continuous intracranial pressure recording. Three brain-tumor patients and two benign intracranial hypertension patients were included. The intracranial pressure was recorded through an indwelling ventricular catheter attached to a pressure transducer. The systemic blood pressure was recorded through an intraarterial catheter placed in the femoral artery. The recordings were made from 18 to 40 hours and a total of 770 plateau waves were examined in this study. The systemic blood pressure showed little or no change in spite of a marked rise in intracranial pressure. The respiratory alterations were always noted during the plateau waves. This respiratory changes during the plateau waves were assigned into three patterns. The first was the suppressed respiratory pattern during the entire course of the plateau waves (Type I): the second was the pattern characterized by the initial suppression followed by the late hyperventilation (Type II); and the third was the hyperventilation pattern during the entire course of the plateau waves (Type III). The pattern of Type I was noticed in 65% of the observed plateau waves, the pattern of Type II in 23%, and the pattern of Type III in 12%. The heart rate decreased in most plateau waves, but there was little change in the heart rate in some plateau waves.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Brain function in patients with plateau waves studied by compressed spectral array in long-term EEG monitoring].

The intracranial pressure, systemic blood pressure and compressed spectral array in EEG monitoring were studied in three patients with typical plateau waves in continuous intracranial pressure recordings. Two patients with brain-tumor and one patient with aqueductal stenosis were included. The intracranial pressure was recorded through an indwelling ventricular catheter attached to a pressure transducer. The systemic blood pressure was recorded through an intraarterial catheter placed in the femoral artery or the dorsalis pedis artery. To obtain continuous and compressed spectral array in the EEG, Berg-Fourier Analyzer by the OET-Biomedica Company of Italy was used. Simultaneous recordings of the intracranial pressure, systemic blood pressure and EEG spectral analysis were made for 180 minutes in each patient. During the plateau waves, the systemic blood pressure did not rise in spite of a marked increase in intracranial pressure, resulting in a marked decrease in the cerebral perfusion pressure. The patients, however, showed no clinical symptoms resulting from ischemia of the brain, such as vasopressor response and impairment of consciousness, but complained only headache. The spectrograms in these patients were characterized by a constant and predominant activity in the alpha or high frequencies. This structural aspect was retained throughout the continuation of plateau waves. The power of low frequencies only appeared transiently. The results suggest that some mechanisms producing and maintaining the fast and/or alpha wave activity may participate in the recurrent appearance of plateau waves.

Adult↗
PubMed1985

[Study of the descending tentorial herniation sign in patients with putamenal hemorrhage at the acute stage].

A sign of descending tentorial herniation (DTH) on computed tomography (CT) in 48 patients with putamenal hemorrhage was examined in the acute stage. Correlation between the DTH sign and prognosis for survival was studied in two groups; a conservative group and an operative group. Patients were grouped according to the presence or absence of DTH sign on CT. Grade 0: no herniation sign; Grade I: an encroachment upon the lateral aspect of the suprasellar cistern (impending herniation); Grade II: widening of the crural and ambient cistern on the same side as hematoma (actual herniation); Grade III: effacement of the cisternal space at the tentorial level (advanced stage of herniation). Twenty-one patients (44%) with Grade 0 DTH sign showed a good prognosis in both conservative and operative groups. Six patients (13%) with Grade I DTH sign also showed a good prognosis in both the conservative and the operative groups except one patient with anisocoria. There were 14 patients (29%) with Grade II DTH sign. Three of them who were treated conservatively showed only mild impairment of consciousness at the initial phase, but became worse 3-4 hours later. In the remaining patients who showed severe impairment of consciousness from the beginning of the illness, prognosis was poor except for patients with hematoma evacuation. Seven patients (15%) with Grade III DTH sign had poor prognosis both in the conservative and the operative groups. It is suggested that, in the acute stage of patients with putamenal hemorrhage, operative procedure should rapidly be performed not only for the clinical herniation sign but also for the DTH sign on CT even if the patients showed no clinical sign and only impairment of consciousness.

Acute Disease↗
PubMed1985

[A case of male prolactinoma presenting extremely high serum prolactin levels and biphasic response to CB-154 suppression test].

A 33-year-old male was admitted to the Department of Neurosurgery, Fukui Medical School with a complaint of headache. There were no neurological deficits on admission. Craniogram demonstrated a so-called "phantom sella". A computed tomography revealed a high density mass lesion and the mass was enhanced well, that mainly extended from the sella to the left middle cranial fossa. The left carotid angiogram revealed an avascular mass lesion extending from the sella to the left middle cranial fossa. Pituitary function tests revealed an extremely high serum prolactin (PRL) levels (70, 100 ng/ml). PRL response to TRH was delayed in peak and the high level continued. Serum PRL levels elevated to 90, 800 ng/ml at 180 min after injection of TRH. A biphasic response was demonstrated in response to CB-154 suppression test to PRL secretion, that is, CB-154 stimulated PRL release initially (up to 90 min) and suppressed thereafter. Serum PRL levels (178, 400 ng/ml) reached to peak about 90 min after CB-154 administration. Response of growth hormone (GH) and adrenocorticotropic hormone (ACTH) to insulin were also impaired. Craniotomy was performed. The tumor was partially removed and was diagnosed as a prolactinoma histologically. Tumor tissue removed was subjected to the monolayer culture and electron microscopic study. Their observations demonstrated hyperactive PRL secretion of the individual cells. A total dose of 5,000 rads was irradiated postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗