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Biomedical subjects

Y Haga

Publications and source records attributed to Y Haga.

At least 91 records · Page 5Linked to original sources
PubMed1993

Granulocyte superoxide anion and elastase release during cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) is known to induce several pathogenic responses in cardiovascular surgery. To explore leukocyte activation during PCB, we investigated superoxide anion (O2-) production by granulocytes in 6 patients undergoing aortocoronary bypass surgery. O2- production was determined with chemiluminescence amplified by a cypridina luciferin analogue. Granulocytes collected from the blood in the arterial site of the CPB circuit were stimulated by phorbol myristate acetate, n-formyl-methionyl-leucyl-phenylalanine, and opsonized zymosan. All the stimulators failed to disclose a significant difference between the magnitude of chemiluminescence during and after CPB. However, significant complement activation was detected, and the plasma level of granulocyte elastase increased gradually during and after CPB. This discrepancy between the unchanged O2- production by stimulated granulocytes and the increase in inflammatory mediators including granulocyte elastase may be due to sequestration of activated granulocytes in extravascular tissues. Namely, it was highly likely that activated granulocytes responsible for the increased plasma elastase level were sequestered and remained outside the blood circulation.

Aged↗
PubMed1993

Identification of the deterministic chaos in cardiovascular dynamics by the use of the non-linear mathematics.

Chaotic behavior in cardiovascular dynamics was thought to be one of the important information to analyze the circulatory regulatory system. Several investigators studied the attractor in the signals of the electrocardiogram, and found the strange attractor, suggesting dynamics compatible with deterministic chaos, by the use of the non-linear mathematics. It is interesting problem to analyze the hemodynamic parameters by the use of non-linear mathematics for the determination of the physiologically optimal circulatory condition. In this study, Chaos analyzing system was developed to identify the deterministic chaos in cardiovascular regulatory system by the use of the non-linear mathematics including phase plane plots, embedding, and lyapunov exponents. Time series data of the hemodynamic parameters in the chronic animal experiments was analyzed by this system, and satisfactory attractor was obtained by the use of the phase plane plots and embedding techniques. Furthermore, calculation of the lyapunov exponents showed the existence of the deterministic chaos in arterial blood pressure in the chronic animal experiments using adult goats, suggesting this tool is useful for analyzing cardiovascular dynamic behavior.

Animals↗
PubMed1993

[A study on ACTH dosage for treatment of West syndrome].

We conducted a retrospective study of 50 patients with West syndrome who had been treated with ACTH. The patients were classified into two groups; group I, receiving standard dose of ACTH (0.025 mg/kg/day); and group II, receiving low dose of ACTH (0.015 mg/kg/day). The short-term effect of treatment was evaluated. Each group was further divided into two subgroups; cryptogenic (I-C, II-C) and symptomatic (I-S, II-S). There was no significant difference in the control rate of clinical seizures, between the two dosage groups of cryptogenic etiology. In the symptomatic cases, a greater effectiveness was achieved in group II-S than I-S. None of the patients with cryptogenic etiology experienced any relapse of infantile spasms. Patients with symptomatic etiology had a higher incidence of relapse. The rate of clinical and EEG seizure control was lower, and the incidence of side effects was higher in group I-S patients. The poor short-term effect of treatment in group I-S patients may be due to a higher incidence of prenatal etiology.

Adolescent↗
PubMed1993

[Atypical early infantile epileptic encephalopathy with suppression-burst].

We report an 8-month-old infant with tonic spasms that started at the age of 38 days and occurred in clusters. He had no myoclonic seizures, or erratic myoclonus. Repeated simultaneous video-EEG monitoring revealed abrupt flexion of the neck and extremities associated with high voltage slow waves preceded by multiple spikes and/or sharps, which resembled spasms seen in West syndrome. Interictal EEGs, before and after the onset of epilepsy, showed suppression-burst. The bursts consisted of irregular high voltage slow waves mixed with poorly developed spike before the onset of epilepsy. On the other hand, duration of suppression phase ranged from 1 to 27 seconds, and burst-burst interval from 2 to 30 seconds after the onset of epilepsy. He was considered as having an atypical early infantile epileptic encephalopathy with suppression burst.

Diagnosis, Differential↗
PubMed1992

Characterization of bilirubin transport system by human peripheral blood mononuclear cells.

Decreased immune responses have been observed in hyperbilirubinemic patients. This study investigates bilirubin transport into human peripheral blood mononuclear cells (PBMNCs). In vitro incubation of PBMNCs at 37 degrees C with 0-12 mg/dl bilirubin in solution with a fixed bovine serum albumin (BSA) concentration (3.0 g/dl) resulted in a dose-dependent increase of intracellular bilirubin in both monocytes and lymphocytes. Bilirubin uptake in monocytes was significantly higher (up to 2.7 times) than in lymphocytes under the same culture conditions. When PBMNCs were incubated with varying concentrations of bilirubin (0-16 mg/dl) in fixed BSA (3.0 g/dl) solution or at a fixed bilirubin/albumin molar ratio (0.4), the initial velocity of uptake in both cell fractions was proportional to the free (unbound to albumin) bilirubin concentration rather than the total bilirubin concentration. Bilirubin uptake by both cell fractions was significantly inhibited by treatment with metabolic inhibitors. Bilirubin uptake by monocytes continued to increase in parallel with incubation temperature from 0 degrees C to 40 degrees C, whereas uptake by lymphocytes reached a maximal level at 20 degrees C and remained constant thereafter. These results suggest that monocytes and lymphocytes incorporate bilirubin in proportion to the free bilirubin concentration and this function may rely on different energy-dependent mechanisms.

Adult↗
PubMed1992

Surgical reconstruction of an ascending aortic dissection in Takayasu's arteritis.

A 45-year-old Japanese woman with Stanford type A dissecting aortic aneurysm underwent a reconstructive operation on the ascending aorta. Histopathological diagnosis was Takayasu's arteritis in the chronic and inactive phase. It is very rare that a dissecting aortic aneurysm results from Takayasu's arteritis. Long-standing hypertension and fragility of the aortic media due to disruption of elastic fibers were suspected to cause dissection in the entire aorta in this case.

Aortic Dissection↗
PubMed1992

Flow cytometric measurement of intracellular bilirubin in human peripheral blood mononuclear cells exposed to unconjugated bilirubin.

Human peripheral blood mononuclear cells were incubated at 37 degrees C with bilirubin in bovine albumin solution. Histological analysis of bilirubin-treated cells demonstrated a prominent brown pigment deposited in the cytoplasm. Homogenates of these cells in chloroform-methanol solution showed an identical absorption spectrum with pure bilirubin dissolved in the same solution. When bilirubin-treated cells were excited at 488 nm, a significant autofluorescence was detected by flow cytometry at 585 nm in a dose-dependent manner, which had a significant correlation with the amount of bilirubin chemically extracted from the cells (r = 0.963, n = 34, p less than 0.001). Intraassay and interassay variability of the autofluorescence by flow cytometric analysis was small (both less than 5%). When bilirubin-treated cells were stained with fluorescein-labeled anti-CD14 antibody, the CD14 positive cell population can be fractionated without interference of autofluorescence derived from intracellular bilirubin. These results suggest that flow cytometric analysis of bilirubin-treated cells can quantitate intracellular bilirubin, and that bilirubin does not interfere with analysis of surface antigens.

Adult↗
PubMed1992

Usefulness of PET scan in a child with mesial frontal lobe epilepsy.

Positron emission tomography (PET) scan with 18F-fluorodeoxyglucose (18F-FDG) was performed in a 14-year-old boy who had seizures suspected to have originated in mesial frontal lobe. The seizures occurred in clusters and were characterised by a change in the facial expression at seizure onset and complex motor manifestations consisting of kicking, swaying and screaming. Ictal EEG showed rhythmic alpha-waves in the left frontal area association with the ictus. Cerebral CT, MRI and SPECT revealed nothing of significance, but the PET brain scans showed frontal and parietal hypometabolism, which was most prominent in the left mesial frontal lobe. The present case suggests that FDG-PET scanning may be useful for the diagnosis of the mesial frontal epilepsy, when other imaging studies fail to show abnormalities.

Adolescent↗
PubMed1992

[A steroid-effective case with "prolonged" cerebellar ataxia].

We reported a girl with "prolonged" cerebellar ataxia for whom steroid was effective. At the age of 9 months, she developed gait disturbance, tremor and abnormal eye movements following exanthema subitum. Her symptoms were prolonged for more than 4 months and she was admitted to our hospital. The symptoms were successfully suppressed with repeated ACTH treatment but recurred in a few weeks after cessation of the therapy. Steroid was also effective but reduction of the dosage resulted in worsening of symptoms. Immunological mechanism was suspected for her disorder because of her response to steroid and ACTH.

Adrenocorticotropic Hormone↗
PubMed1991

Immunotherapy with monoclonal antibody (Mab) in pancreatic adenocarcinoma.

Conventional therapy of pancreatic exocrine cancer is disappointing. The poor prognosis of the disease challenges development of novel therapeutic strategies. We report the results of clinical trials of the monoclonal antibody (Mab) 17-1A in patients with histologically verified unresectable pancreatic exocrine cancer. No antitumor response was seen in 18 patients treated with Mab 17-1A (500 mg) admixed with 10(9) autologous mononuclear cells, and 81% of the patients developed antimouse antibody response. Combination of recombinant gamma interferon and Mab 17-1A mixed with autologous mononuclear white cells resulted in complete response of 4-mo duration in 1 out of 25 evaluable patients and unusually stable disease from 4 to 48+ mo in another 6 patients. High intermittent doses of infused Mab 17-1A did not show any objective antitumor response and caused serious anaphylaxis in two of the patients in the trial. Because examination of six pancreatic adenocarcinoma cell lines with different doses of Mab 17-1A and IL-2 failed to augment lytic activity of mononuclear effector cells against all cancer cell lines tested, there seemed to be no rationale for pursuing clinical studies with IL-2 and Mab 17-1A in either the murine or chimeric form. Attractive therapeutic approaches include active immunotherapy with immunization using idiotypic antibodies or targeted toxicity with the use of radioimmunoconjugates, particularly 125I-labeled chimeric Mab 17-1A.

Adenocarcinoma↗
PubMed1991

A new technique for bridging to heart transplantation: feasibility of monoventricularization of bilateral ventricles with LVAD.

Because the prognosis of ventricular septal perforation (VSP) and mitral regurgitation (MR) after acute myocardial infarction (MI) is remarkably poor, heart transplantation would be necessary for many of those patients. A new bridging technique was examined in canine models. The bilateral ventricles communicating through VSP were monoventricularized with mitral valve closure and maintained the pulmonary circulation, which had low vascular resistance. The systemic circulation was maintained by a left ventricular assist device (LVAD) placed between the left atrium and the aorta. VSP and MR were made in eight mongrel dogs (pulmonary to systemic flow ratio = 2.24 +/- 0.90). They were then monoventricularized and equipped with LVADs. The hemodynamic state was evaluated (a) in intact hearts, (b) after VSP and MR were made, and (c) after monoventricularization and assisted circulation by LVAD. Cardiac output was (a) 90.60 +/- 23.16, (b) 42.23 +/- 15.76, and (c) 73.43 +/- 15.14 ml/min/kg (a vs. c: not significant; a vs. b and b vs. c: p less than 0.001); mean aortic pressure was (a) 96.75 +/- 24.69, (b) 30.25 +/- 11.08, and (c) 66.50 +/- 18.40 mm Hg (a vs. b: p less than 0.01, a vs. c and b vs. c: p less than 0.05); central venous pressure was (a) 4.76 +/- 1.68, (b) 8.94 +/- 2.17, and (c) 10.68 +/- 2.43 mm Hg (a vs. c: p less than 0.01, a vs. b: p less than 0.05, and b vs. c: not significant). Mean pulmonary arterial pressure and mean left atrial pressure did not show any significant difference among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗