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Biomedical subjects

M Aiba

Publications and source records attributed to M Aiba.

123 records · Page 7Linked to original sources
PubMed1976

Enzyme histochemical observations of diffuse pulmonary fibrosis of rats experimentally induced by ionizing irradiation.

The right lungs of Sprague-Dauley rats were irradiated with single doses of 1000 r, 2000 r or 3000 r to induce radiation pneumonitis and diffuse fibrosis, and the alkaline and acid phosphatase (A1-Pase, Ac-Pase) activities of the lungs were observed histochemically. Only the lungs irradiated with 3000 r steadily exhibited sequential changes leading to radiation pneumonitis and subsequent diffuse fibrosis, whereas the lungs irradiated with 2000 r developed only some degree of radiation pneumonitis. Alveolar capillary endothelia in the lesion of pulmonary fibrosis exhibited an intense activity of A1-Pase, while the endothelia in all the other experimental conditions did not show this activity. Alveolar macrophages increased their sizes and the activity of Ac-Pase after the irradiation. In the later stages, large foamy macrophages with thin diffuse deposits of the reaction products became predominant. These macrophages never exhibited A1-Pase activity. Type II alveolar epithelial cells showed an intense A1-Pase activity on their microvilli, and their Ac-Pase activity was negligible in non-irradiated lungs. Bizarre cells, appearing at the stage of radiation pneumonitis, showed an intense A1-Pase activity on their cell membranes and a weak and diffuse Ac-Pase activity in their cytoplasms. Septal cells achieved the A1-Pase activity 3 or 4 weeks after the irradiation when mast cells were not yet seen in the alveolar septa.

Acid Phosphatase↗
PubMedDate not supplied

Retrospective analysis of prognostic factors affecting the thyroid functional status after subtotal thyroidectomy for Graves' disease.

To determine the factors causing thyroid dysfunction after surgery for Graves' disease, we studied 321 patients who underwent subtotal thyroidectomy during the 7-year period from 1981 to 1987. Thyroid functional status was evaluated biochemically and the patients were divided into four categories: recurrent hyperthyroidism, euthyroidism, latent hypothyroidism, and hypothyroidism. The following factors were analyzed: sex, age at onset of the disease, indication for surgery, serum titer of antimicrosomal hemagglutination antibody (MCHA), weight of resected thyroid tissue, size of remnant thyroid relative to body surface area, pathological findings of lymphoid follicles, and lymphocytic infiltration in the thyroid tissue. Probabilities of failure (recurrent hyperthyroidism and hypothyroidism) were estimated by the Kaplan-Meier method. Prognostic factors for failure were identified by using Cox's proportional hazards model. The incidence of hyperthyroidism and hypothyroidism 5 years after subtotal thyroidectomy was 16.2% and 9.6%, respectively. Significant factors for hyperthyroidism were relatively large thyroid remnant, high serum titer of MCHA (greater than or equal to 1:3200), and age at onset of the disease less than 20 years. The significant factor for hypothyroidism was severe lymphocytic infiltration. The level of postoperative thyroid stimulating hormone (TSH)-binding inhibition immunoglobulins (TBII) in patients with recurrence was significantly higher than in patients in remission. It is reasonable to determine the amount of remnant thyroid tissue in relation to patient body surface area. Although subtotal thyroidectomy can induce immunological remission by reduction of antigen, if the remission disappears, that is if TBII increases, recurrence of hyperthyroidism may develop even in patients without the unfavorable factors.

Adolescent↗
PubMedDate not supplied

A magnetically actuated left ventricular assist device.

Over the past 6 years, research has led to development of a small, lightweight, power-efficient, uniquely simple ventricular assist device driven by a magnetic actuator. Magnetic actuation permits total elimination of all mechanical motion converter components used for pusher plate displacement, resulting in a significant reduction in complexity and resultant increase in reliability. Extensive in vitro mock loop development has resulted in a left ventricular assist device (LVAD), the primary design parameters of which for the clinical prototype actuator and pump are 1) an actuator weight of 312 g, 2) actuator size of 32.5 cm3, 3) power requirements of 7.8 to 11.4 watts (60-100 beats per minute [BPM]), and 4) system efficiency of 24% to 34% and average dynamic stroke volume of 65 ml. Initial in vivo tests assessed this LVAD's performance in four sheep under three acute conditions of ventricular dysfunction. The results demonstrate that, at a pump-rate of 100 BPM, mean aortic pressure increased by 45-50 mmHg during 1) beta blockade, 2) coronary ligation, and 3) ventricular fibrillation. Pump flow ranged from 2.71 L/min to a maximum of 4.6 L/min. Acute test periods were arbitrarily set for 6 hours duration. Of the four sheep, two survived, one lived 5 hours, and the fourth lived 4.5 hours. Global fibrillation was the primary cause of failure. This initial in vivo data demonstrates the pump's ability to maintain satisfactory hemodynamic parameters of flow and pressure under three acute conditions of extreme left ventricular dysfunction in an animal model. These initial LVAD performances were encouraging. Further tests will use calves with a greatly expanded performance evaluation protocol.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Enhanced anti-tumour effect of cisplatin with low-voltage electrochemotherapy in hamster oral fibrosarcoma.

The aim of this study was to determine the effects of low-voltage electrochemotherapy with intraperitoneal cisplatin on hamster oral fibrosarcoma. Oral fibrosarcoma was transplanted submucosally into the cheek pouch mucosa of 100 hamsters. After transplantation, the hamsters were randomly divided into four equal groups. These groups received no treatment (D-E-); 2 mg/kg body weight cisplatin treatment without electroporation (D+E-); electroporation without cisplatin treatment (D-E+); or 2 mg/kg body weight cisplatin treatment followed by electroporation (D+E+). Electrical pulse treatment together with cisplatin injection markedly reduced the size of the tumour, whereas cisplatin injection or electrical pulse treatment alone did not. These results clearly indicate that the anti-tumour effect of cisplatin on hamster oral fibrosarcoma was considerably potentiated or enhanced by the administration of local electrical pulses at low voltages.

Animals↗
PubMedDate not supplied

Clinicopathological and prognostic significance of thymidine phosphorylase expression in gastric carcinoma.

Tumor growth depends on angiogenesis. Thymidine phosphorylase (dThdPase) is identical to platelet-derived endothelial cell growth factor (PD-ECGF), and has angiogenic activity. We investigated the expression of dThdPase in 116 gastric carcinoma tissue samples by immunohistochemical staining, and assessed whether its expression was correlated with clinicopathological factors or with the prognosis. dThdPase expression was correlated with clinicopathological factors and may be a good prognostic indicator for gastric carcinoma. To determine whether dThdPase expression was a prognostic factor that was independent of the depth of invasion or lymph node metastasis, we conducted a survival analysis using Cox's proportional hazard model. This analysis revealed that dThdPase expression was the most significant prognostic indicator and was useful for predicting the outcome of gastric carcinoma.

Female↗
PubMedDate not supplied

Alpha-fetoprotein producing Barrett's esophageal adenocarcinoma: a case report.

A 59-year-old man was admitted to our hospital with upper abdominal pain. His serum alpha-fetoprotein (AFP) level was very high, 1500 ng/ml. Upper gastrointestinal endoscopy revealed depressed lesion at 36 cm from the upper incisors, with columnar epithelium lining the esophagus circumferentially to the oral side of the lesion. Histological examination of biopsy specimens revealed a tubular adenocarcinoma as well as the presence of gastric columnar epithelium with intestinal metaplasia. Immunohistochemistry demonstrated AFP in the tumor cells. From these results, a diagnosis of AFP-producing esophageal adenocarcinoma occurring in Barrett's esophagus, a condition which is extremely rare in Japan, was established. Computed tomography (CT) showed multiple metastasis on the liver and wide-ranging lymph node metastasis. Chemotherapy was not effective and the patient died about 2 months after the start of treatment. The AFP-producing esophageal adenocarcinoma presented here had biological characteristics similar to those of AFP-producing gastric cancer.

Adenocarcinoma↗
PubMedDate not supplied

Effect of intratumoral OK-432 administration of thymidine phosphorylase expression in human gastric carcinoma.

It is known that thymidine phosphorylase (dThdPase) is increased in various types of malignant tumors and is induced by cytokines. In this study, we have investigated the effects of OK-432, which induces multiple cytokines, on dTHdPase expression and angiogenesis in human gastric carcinomas. We examined 25 patients who underwent gastrectomy for gastric carcinoma. OK-432 was directly injected in tumors in 16 (OK group) of 25 patients via endoscopy before operation and the other 9 patients were not treated (control group). The dThdPase activity in carcinoma tissues of the OK group was significantly higher than that of the control group (P < 0.05). The amounts of IL-1 alpha, IFN-alpha, and IFN-gamma in carcinomas in the OK group were significantly higher than in the controls (P < 0.05), and these were significantly correlated with the dThdPase activity. Intratumoral OK-432 administration enhances the expression of dThdPase in gastric carcinoma cells by inducing various cytokines.

Antineoplastic Agents↗
PubMedDate not supplied

Study on endoscopic esophageal mucosal resection with ligating device. I--Clinical study.

BACKGROUND/AIMS: EEMRL (endoscopic esophageal mucosal resection with a ligating device) has become increasingly popular. In this article, we review 13 clinical cases of EEMRL. METHODOLOGY: Since 1993, we have performed EEMRL to treat 15 lesions in 13 patients. Twelve squamous cell carcinomas (mucosal cancer in 10 and submucosal cancer in 2) were included among the 15 lesions. RESULTS: EEMRL failed to achieve complete resection of the 2 submucosal lesions (3.0 and 2.8 cm in maximum diameter). However, esophageal lesions could be removed successfully when 2.5 cm or less in maximum diameter. The procedure was not associated with any complication. CONCLUSIONS: Our clinical study showed that this technique may be indicated for esophageal cancer with a maximum diameter < or = 2.5 cm and confined to the mucosa. EEMRL is a technically easy and minimally invasive therapy which could be useful for the treatment of early esophageal cancer.

Aged↗
PubMedDate not supplied

Study on endoscopic esophageal mucosal resection with ligating device. II--Experimental study.

BACKGROUND/AIMS: This study reports on animal experiments regarding the safety of endoscopic esophageal mucosal resection with a ligating device (EEMRL), as well as the amount of mucosa which can be removed by this technique, the depth of resection and the feasibility of piecemeal resection. METHODOLOGY: Three experiments were performed in six mongrel dogs under general anesthesia. RESULTS: When EEMRL was done without submucosal injection of saline, resection reached the muscular layer and caused esophageal perforation. The average dimensions of the mucosal pieces resected using 8-, 10-, and 12-mm devices was 13 x 10 mm, 18 x 15 mm, and 22 x 18 mm, respectively. Resection reached the mid-plane of the submucosa and the depth was almost uniform. After piecemeal resection, there was no macroscopically visible mucosa at the resection site and each mucosal piece was resected along the mid-plane of the submucosa. CONCLUSIONS: The experimental study indicated that submucosal injection of saline is essential to prevent esophageal perforation. It also showed that EEMRL allows resection up to the mid-plane of the submucosa, that the 12-mm device allows en bloc resection of lesions < or = 15 mm in diameter and that EEMRL is suitable for piecemeal resection.

Animals↗
PubMedDate not supplied

Effects of allopurinol pretreatment with pulmonary flush on lung preservation.

This study was designed to test whether use of allopurinol could improve lung preservation after 6 hours of cold storage. Thirty-two rabbits were divided into four groups (n = 8 each group): (1) the control group received no flush or storage, (2) the EC group received Euro-Collins (EC) solution for both flush and storage, (3) the Allo-F group received Euro-Collins solution with allopurinol (1 mmol/L) for both flush and storage, and (4) the Allo-R group received Euro-Collins solution to which allopurinol (1 mmol/L) was added only to the reperfused blood. For groups 2 through 4, the lungs were flushed (40 ml/kg) in situ, excised, and then stored at 4 degrees C. After storage, the lungs were reperfused for 1 hour with an in vitro blood-perfused ventilated model. Lung function was measured during reperfusion with mean pulmonary arterial pressure, end-inspiratory airway pressure, and blood gas data. The lung wet/dry weight ratio was used to measure lung edema. The lungs in the EC group had a significant increase in mean pulmonary arterial pressure, airway pressure, and wet/dry weight ratio when compared with the control group. The mean pulmonary arterial pressure in either of the groups receiving allopurinol was consistently lower than that in the EC group. The airway pressure in the Allo-R group also significantly decreased compared with the EC group.(ABSTRACT TRUNCATED AT 250 WORDS)

Allopurinol↗