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Biomedical subjects

H Higashi

Publications and source records attributed to H Higashi.

At least 181 records · Page 10Linked to original sources
PubMed1989

Detection of glycoproteins as tumor-associated Hanganutziu-Deicher antigen in human gastric cancer cell line, NUGC4.

NUGC4 cells derived from a human gastric cancer gave 6% Hanganutziu-Deicher (HD) antigen-positive cells by flow cytometric analysis using an affinity-purified chicken antibody to N-glycolyneuraminyl-lactosyl-ceramide (HD3 ganglioside). The cells showed no HD antigenic ganglioside by thin-layer chromatography enzyme-immunostaining; however, they were revealed to contain HD antigenic proteins with molecular masses of 150, 100, 90, 70, 65, 60, 47, and 40 kDa, by both immunoblotting after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoprecipitation of [35S]-methionine-labeled proteins, followed by SDS-PAGE and autoradiography. Neuraminidase treatment destroyed the antigenicity of all proteins, indicating that these molecules are glycoproteins and have N-glycolyneuraminic acid at the non-reducing terminal of carbohydrate chains as an HD antigenic epitope.

Antigens, Heterophile↗
PubMed1989

Angioarchitectural classification of esophageal varices and paraesophageal veins in selective left gastric venography.

An improved radiographic classification of esophageal varices and paraesophageal veins was devised. Esophageal varices were divided into palisading and bar types. Paraesophageal veins were divided into intra-abdominal and thoracoabdominal types, with the latter being further subdivided into right-side-predominant and left-side-predominant types. The existence of the thoracoabdominal paraesophageal veins was significantly related to the preoperative endoscopic findings of the red sign and the form of the esophageal varices. Left-side-predominant paraesophageal veins were likely to drain the splanchnic blood flow to the hemiazygos vein. The largest grade of red sign was found in 88.9% of the patients with combination of bar type and intra-abdominal type and the largest form was in 88.9% of those with palisading and right-side thoracoabdominal types. The pressure gradients across the shunt were significantly lower in the right thoracoabdominal type than in others. Our study suggests that treatment be designed according to the vascular patterns of the lower esophagus.

Esophageal and Gastric Varices↗
PubMed1989

Platelet aggregability after endoscopic intravariceal injection of 5 per cent ethanolamine oleate into oesophageal varices.

Platelet aggregability and the coagulative and fibrinolytic systems were examined in 45 patients who underwent endoscopic injection sclerotherapy for oesophageal varices. Five per cent ethanolamine oleate, the sclerosant used, was injected into the oesophageal varices. There were significant increases in the concentrations of fibrinopeptide A, fibrinopeptide B-beta-15-42 and fibrin degradation products-E after the sclero-therapy. At 1 h after the sclerotherapy the mean(s.e.m.) platelet aggregation was significantly suppressed to 71.9(4.2) per cent of that before the treatment (P less than 0.01). There was a gradual recovery within 1 week to the same level seen before the sclerotherapy. Thromboxane B2 and 6-keto-prostaglandin F1 alpha, both stable products of thromboxane A2 and prostacyclin respectively, showed significant temporary increases after the sclerotherapy (P less than 0.01). The peak increase in the level of thromboxane B2 was noted within 1 h after the sclerotherapy and earlier than that for 6-keto-prostaglandin F1 alpha. This increased ratio of prostacyclin and thromboxane A2 may be related to the marked limitation in platelet aggregation.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

Enhancement of dopamine actions on rat nucleus accumbens neurones in vitro after methamphetamine pre-treatment.

1. Intracellular recordings were made from the nucleus accumbens neurons in brain slices from rats previously treated with saline or methamphetamine. 2. In neurones from both methamphetamine- and saline (control)-treated rats, dopamine (0.1 mM) produced three types of responses: a biphasic response consisting of an initial hyperpolarization followed by a depolarization, a monophasic hyperpolarization and a simple depolarization. 3. Haloperidol (1 microM) reversibly suppressed both responses to dopamine; (-)-sulpiride (1 microM) selectively abolished the depolarization and prolonged the hyperpolarization. Forskolin (10 microM) and dibutyryl adenosine 3',5'-cyclic monophosphate (1 mM) mimicked the hyperpolarization. Both of the latter two substances were more effective in neurones from methamphetamine-treated rats than in neurones from control rats. 4. In slices from methamphetamine-treated rats, the dose-response curve for the dopamine hyperpolarization was shifted to the left of that seen in neurones from control rats by a factor of approximately 100. The dose-response curve for the dopamine depolarization was shifted to the right about 10-fold in neurones from rats treated with methamphetamine. 5. In slices from control rats, dopamine (less than or equal to 0.1 mM) and methamphetamine (less than or equal to 1 microM) had no effect on the EPSPs evoked by focal electrical stimulation of the periaccumbens regions: dopamine (greater than or equal to 10 nM) and methamphetamine (1 microM) markedly depressed the EPSPs in slices from methamphetamine-treated rats. Depolarizations evoked by application of exogenous glutamate were unaffected by dopamine (less than 5 microM). 6. In slices from methamphetamine-treated rats, dopamine (greater than or equal to 10 nM), forskolin (greater than or equal to 1 microM) and dibutyryl adenosine 3',5'-cyclic monophosphate (1 mM) depressed Ca2+-dependent spikes as well as the EPSPs. Haloperidol (1 microM) completely reversed the depressions of the EPSPs and Ca2+-dependent spikes by dopamine, while (-)-sulpiride (1 microM) was only partially effective. 7. These results indicate that chronic methamphetamine administration leads to enhancement of the actions of dopamine at D1 receptors located on glutamate and/or aspartate nerve terminals and of the dopamine hyperpolarization of principal neurones, which is also mediated by D1 receptors.

Action Potentials↗
PubMed1989

Membrane properties and synaptic responses of the guinea pig nucleus accumbens neurons in vitro.

1. The membrane properties and synaptic responses of guinea pig nucleus accumbens neurons in vitro were studied with intracellular recording methods. 2. The population of neurons could be divided into groups of low (20-60 M omega, average 46.5 M omega) and high (60-180 M omega, average 96.5 M omega) input resistance. The resting membrane potential in both groups was approximately -70 mV. 3. Other membrane properties were quite similar in both groups. Inward rectification occurred at potentials more negative than -80 mV; this was blocked by Cs+ (2 mM). Membrane potential oscillations were observed at potentials between -65 and -55 mV; these were blocked by tetrodotoxin (TTX, 0.5 microM). Outward rectification occurred at potentials less negative than -45 mV; this was depressed by tetraethylammonium (TEA, 10 mM). 4. Action potentials elicited by small depolarizing current pulses (2-5 ms, 0.3-0.5 nA) were approximately 95 mV in amplitude and 1.0 ms in duration. The afterhyperpolarization following each action potential was less than 30 ms in duration, and no accommodation of action-potential discharge was seen at frequencies up to 40 Hz. The action potentials were reversibly blocked by TTX (0.3 microM). In addition, TTX-insensitive, Ca2+-dependent spikes were evoked by passing larger and more prolonged current pulses (greater than 40 ms, greater than 0.5 nA) across the membrane. 5. Focal electrical stimulation of the slice surface with low intensity (1 ms, less than 10 V) elicited excitatory postsynaptic potentials (EPSPs) in neurons of both high- and low-resistance groups. The reversal potential (+10.2 mV) for the EPSPs was close to the reversal potential (+7.7 mV) of the responses to glutamate applied in the superfusing solution. The N-methyl-D-aspartic acid (NMDA) receptor antagonists, D-alpha-aminoadipic acid (1 mM) and DL-2-amino-5-phosphonovaleric acid (DL-APV, 250 microM), reversibly depressed the EPSP; the glutamate uptake inhibitor, L-aspartic acid-beta-hydroxamate (50 microM), or removal of Mg2+ from the superfusate, augmented the EPSP. 6. When the intensity of the focal stimulus was increased (1 ms, greater than or equal to 10 V), a second larger depolarizing response (duration, 800 ms to 2 s) could be evoked in addition to the smoothly graded EPSP. This was seen only in cells of the high-resistance group (90-130 M omega).(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1989

Restoration of ATP contents in the transplanted liver closely relates to graft viability in dogs.

Searching for a marker of graft viability, adenosine triphosphate (ATP) content in the graft tissue was measured sequentially during orthotopic liver transplantation (OLT) in 24 adult mongrel dogs. According to the survival period, 12 recipients were divided into two groups: group I - early-death group (n = 6), death within 3 days after OLT and group II - survival group (n = 6), survived more than 7 days after OLT (average 12 days). Serum biochemical findings showed no differences between the two groups except that the prothrombin time on the first postoperative day in group I was significantly longer (p less than 0.05). The ATP content ratio (% of initial value) was significantly higher in group II, compared to that of group I (p less than 0.05), 94 versus 53% at 10 min after perfusion, 31 versus 17% at just before recirculation, respectively. The ATP content ratio recovered significantly to more than 80% at 10 min after recirculation in group II but only to less than 50% in group I. These results suggest that restoration of ATP content in the liver after graft recirculation reflects the viability of the graft and can serve as an appropriate prognostic marker in cases of OLT.

Adenosine Triphosphate↗
PubMed1989

[Electrical membrane properties of neurones of mesencephalic nucleus of fifth nerve in rats].

Intracellular recordings were made from 79 neurones in the mesencephalic nucleus of fifth nerve (MNV) contained within rat brain stem slice preparation in vitro. The electrical membrane characteristics of 20 neurones among them were measured. The resting membrane potential, input resistance and membrane time constant of MNV neurones were -60.3 +/- 5.6 mV, 10.5 +/- 5.4M omega and 1.3 +/- 0.5 ms respectively. No action potential occurred spontaneously at resting membrane potential. The action potential was elicited by application of a depolarizing rectangular pulse to the neuron. The data of 32 MNV neurones action potentials showed that the threshold potentials ranged from -50 mV to -55 mV, the duration of the spike was 0.8 +/- 0.2 ms and the amplitude of the spike was 69.5 +/- 6.1 mV with an overshoot of 11.9 +/- 3.6 mV. The action potential disappeared reversibly by perfusion of Na-free solution or TTX (0.3 mumol/L) added in Krebs solution. The repetitive discharge was elicited by a long lasting depolarizing rectangular pulse applied to the neuron, its frequency was 200-250 Hz at the beginning of the pulse and disappeared before the ending of the pulse. The repetitive discharge usually consists of 2-15 spikes. The halfway disappearance of the repetitive discharge was prevented by TEA or 4-AP. The subthreshold potential oscillation followed the action potential at membrane potential -60(-)-55 mV, and this potential oscillation was not affected by TTX, but it was abolished by perfusion of Ca-free solution. However, its amplitude was increased by TEA or 4-AP. When the resting membrane potential was depolarized, the outward rectification in 40 among 45 MNV neurones was seen, which was inhibited by TEA, 4-AP or Ca-free perfusion. On the other hand, the inward rectification was seen when the resting membrane potential was hyperpolarized, which was inhibited by Cs ion or Na-free perfusion. When the blockers of K channels were added into Krebs solution, the steady state I-V relationship of the neurones was changed correspondingly. It is suggested that the IDR, IA, IK(Ca), and IQ are related to the resting membrane conductances.

Animals↗
PubMed1989

A prospective randomized trial of schedules for sclerosing esophageal varices. 1-versus 2-week intervals.

A prospective randomized trial was performed to compare the efficacy and complications of 1-week (20 patients) and 2-week (20 patients) interval schedules of endoscopic injection sclerotherapy for patients with esophageal varices; 6 were acute, 3 were elective and 31 were prophylactic cases. There were no significant differences between the 1-week and 2-week interval groups with regard to total number of sclerotherapy sessions, total volume of the sclerosant used (5% ethanolamine oleate) or rate of complications such as pyrexia, stricture and pleural effusion. The incidence of ulcer and/or slough formation after EIS was the same in the two groups. Neither early nor recurrent bleeding occurred in any patient in the two groups. Eradication of varices in the 2-week interval group was achieved significantly earlier (p less than 0.05) than in the 1-week interval group.

Acute Disease↗
PubMed1989

Hypoxia in brain slices.

The effects of hypoxia on hippocampal CA1 neurones in tissue slices of the rat brain were studied in vitro by intracellular recording. In response to superfusion of a hypoxic medium equilibrated with 95%N2-5% CO2, a majority of the neurones showed a transient depolarization followed by a hyperpolarization of 5-15 mV in amplitude and 4-12 min in duration. The hyperpolarization was, in turn, followed by a slow depolarization which within 20 min of hypoxic exposure reached a plateau level of about 25 mV above the prehypoxic resting potential. Both the initial hyperpolarization and subsequent depolarization were associated with a reduction in membrane resistance. The hyperpolarization reversed in polarity at a membrane potential of -83 mV. There was an almost linear relationship between amplitude of the hyperpolarization and membrane potential. The hyperpolarization was markedly enhanced in potassium-free media and was depressed in high-potassium solution. Superfusion of ouabain (5-7 microM)-containing medium in normoxic conditions produced hyperpolarizing and depolarizing responses similar to those elicited by hypoxic exposure. The slow depolarization was also mimicked by elevation of the extracellular potassium concentration to 10-20 mM. Evoked i.p.s.p.s were abolished within 4 min of hypoxic exposure while evoked e.p.s. p.s were maintained for about 20 min of hypoxic superfusion. Soma spikes of the neurones elicited by a depolarizing pulse were also well preserved. Their threshold was, however, raised, concomitant with a decrease in the peak amplitude. In a minority of the neurones the slow depolarization was suddenly followed by a rapid depolarization, after which the neurones showed no functional recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Use of biotinylated antibody for the assay of Hanganutziu-Deicher antibodies and antigens in fluids and tissues from cancer patients.

An improved enzyme-linked immunosorbent assay (ELISA) for detection of heterophile Hanganutziu-Deicher (HD) antibodies and antigens, which are frequently detected in sera and/or cancerous tissues from patients with various cancers was developed using biotinylated chicken anti-GM3(NeuGc) antibody and avidin-horseradish peroxidase conjugate. The N-glycolylneuraminyllactosyl-ceramide, GM3(NeuGc) ganglioside was purified from horse erythrocyte membranes. The ELISA procedure required 300 ng GM3(NeuGc) antigen to coat plastic microtiter plates and 190 ng biotinylated antibody per well to give optimum product formation. The technique could detect 6 ng antigen in tissue homogenate as compared to 0.6 ng of the pure compound by inhibition. Chicken anti-GM3(NeuGc) antibody quantitatively inhibited the biotinylated antibody, however, this procedure was not suitable to quantify lower affinity HD antibody in patient sera. Immunostaining specific for HD antigen-positive cells, in tissue sections was by 4 micrograms/ml biotinylated antibody and 200 dilution of Avidin-biotinylated peroxidase complex reagent using pig intestine and lymph node as positive tissues and chicken intestine and lung as negative tissues.

Animals↗
PubMed1988

Specific staining on thin-layer chromatograms of glycosphingolipids of neolacto series and gangliosides with a terminal N-acetylneuraminyl residue by different procedures with wheat germ agglutinin.

Sensitive staining methods with wheat germ agglutinin were developed for the detection of glycosphingolipids of neolacto series (A) and gangliosides with a terminal N-acetylneuraminyl residue (B) on thin-layer chromatograms. (A) Neolacto series glycosphingolipids were treated by beta-galactosidase on the chromatograms in the presence of taurodeoxycholate. Then the chromatograms were incubated with biotinated wheat germ agglutinin followed by incubation with a complex of avidin and biotinated horseradish peroxidase, and the reaction was detected by 4-chloro-1-naphthol. In the case of gangliosides, sialidase treatment on the chromatograms was performed before the beta-galactosidase treatment. The sensitivity of the method for Lc3Cer, nLc4Cer, sialyl-nLc4Cer, and sialyl-nLc6Cer was 4 pmol, 7.6 pmol, 2.9 pmol and 1.4 pmol, respectively. (B) The gangliosides on the chromatograms were oxidized by periodic acid and reduced by NaBH4. Then the chromatograms were stained with wheat germ agglutinin as mentioned above. As little as 0.5 pmol of GM3, NeuAc-nLc4Cer, and NeuAc-nLc6Cer was detected by this method, whereas the detected limits for these gangliosides were 10 pmol, 10 pmol and 2 pmol, respectively, when periodate oxidation was omitted. GM4, GD3 and GD1a were an order less reactive than GM3, GM2, GM1 or GD1b were not stained under the same condition. In contrast to NeuAc-containing gangliosides, any gangliosides with N-glycolylneuraminic acid were not stained by the method in (B).

Chromatography, Thin Layer↗
PubMed1988

Recurrence of varices after oesophageal transection: intra-operative and postoperative assessment by endoscopy.

Intra-operative and postoperative endoscopy were used in 16 patients with portal hypertension to investigate whether intra-operative elimination of oesophageal varices by oesophageal transection with devascularization leads to prevention of variceal recurrence and rebleeding. Intra-operative elimination of the varices was achieved in 12 patients. In ten patients the varices recurred and in two cases rebled, during the follow-up period of 6-43 months (average 25 months). Of the ten patients with recurrent varices, eight (including the two who bled acutely in the postoperative period) successfully underwent endoscopic injection sclerotherapy. Postoperative endoscopy was performed at 5-monthly intervals. It is concluded that intra-operative elimination of the varices will not prevent recurrence and that a closer follow-up using endoscopy more than three times a year is a significant aid in the management of these patients.

Adult↗
PubMed1988

Clinical management of recurrent hepatocellular carcinoma after primary resection.

Curative resections were performed on 121 patients with primary hepatocellular carcinoma from 1975 to 1986 at Kyushu University Hospital, Japan. Up to August 1987 there was a recurrence in 41, detected between 4 and 86 (mean 20) months after surgery. Intrahepatic recurrences were the most common (82 per cent). There was no statistically significant correlation between size of the primary tumour and interval from surgery to detection of recurrence (r = -0.09). Serial measurement of serum alpha-fetoprotein (AFP) was useful for the detection of recurrences. However, the levels of AFP seem to be a non-specific, unreliable test for such patients since this tumour marker showed different ranges before the primary surgery and at the time of recurrence in 5 of the 41 patients (12 per cent). Postoperative chemotherapy with oral 5-fluorouracil had no apparent preventative effect on the recurrence. A second curative resection was effective in four patients, and three survived for over 2 years; the longest survival time is 9 years after the second procedure.

Adult↗
PubMed1988

Trial of sclerosing agents in patients with oesophageal varices.

Forty-five cirrhotic patients with oesophageal varices underwent endoscopic injection sclerotherapy in a prospective randomized trial carried out to compare two sclerosing agents (5 per cent ethanolamine oleate and 2 per cent sodium tetradecyl sulphate (STD] with respect to safety, efficacy and complications. Twenty-three patients were allocated to the ethanolamine group and twenty-two to the STD group. The rate of control of acute bleeding was 100 per cent (6/6) in the ethanolamine group and 75 per cent (3/4) in the STD group. There was a significantly lower rate of postinjection bleeding after the over-tube was removed at the initial session of sclerotherapy when ethanolamine was injected 0/23 versus 7/22, 32 per cent; P less than 0.01) and at the second session there was a significantly (P less than 0.01) higher rate of jet-like bleeding from injection sites in the STD group (6/21, 29 per cent) than in the ethanolamine group (0/22). The disappearance rate of red colour signs 1 week after the initial session of sclerotherapy in the ethanolamine group was 100 per cent and 62 per cent in the STD group. Early oesophageal ulcers developed less frequently in the ethanolamine group (0 and 9 per cent) than in the STD group (24 per cent and 43 per cent both after the initial (P less than 0.05) and the second session of sclerotherapy (P less than 0.01]. Early bleeding from an oesophageal ulcer occurred only in the STD group (5/21, 24 per cent) before the third session of sclerotherapy (P less than 0.05). The rate of early mortality did not differ between the two groups. We conclude that ethanolamine seems to be safer and more efficacious than STD for sclerosing oesophageal varices.

Clinical Trials as Topic↗
PubMed1988

Automatic real-time analysis of human sleep stages by an interval histogram method.

A new interval histogram method for automatic, all-night sleep stage scoring, simulated on a digital computer, is described. The system consists of a 2-step analysis. The first step is recognition of elementary patterns in EEG, EOG and EMG, and the second step is the determination of sleep stages based on these parameters. Correlation of this method with power spectral analysis of the dominant EEG patterns during each sleep stage supported the reliability of the first step analysis. Overall agreement (89.1%) between the computer and human judges was only 3% less than the agreement (92.1%) among the scorers, indicating considerable reliability of the second step. The primary areas of disagreement that arose in the identification of sleep stages occurred with stages 1, 2 and REM. To improve scoring accuracy, the system may require epoch sequence information. The profile of the elementary parameters of the EEG signals clearly illustrated the cyclic nature of these activities throughout the night. The alpha and delta 2 waves clearly separated the awake state from sleep stages. Beta 2 can discriminate stages 1 and REM from stage 2, and the best indicator for distincting stage 1 from REM was muscle activity. Sigma and spindles were prominent during stage 2 sleep. Both delta 2 and high voltage delta waves distinguished stage 3 from stage 4. On the other hand, delta 1 was evenly distributed and seemed to be common to all sleep stages.

Adolescent↗