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Biomedical subjects

M Nagata

Publications and source records attributed to M Nagata.

At least 343 records · Page 19Linked to original sources
PubMed1993

Roles of central nicotinic receptors in regulation of gastric functions.

In the first part of this paper, the effects of single administration of nicotine on gastric motility of urethane-anesthetized rats are briefly summarized from our recently reported papers. Then, the effects of repeated administration of nicotine on the nicotine-induced changes in gastric motility and release of hypothalamic noradrenaline, in vitro, are described, with special references to up-regulation of nicotinic receptors. Nicotine 0.1 nmol administered into the dorsal motor nucleus of the vagus (DMV) elicited a dual change, a decrease followed by an increase in gastric motility. Intravenous administration of nicotine 300 nmol/kg decreased gastric motility. This decrease in gastric motility was inhibited by microinjection of hexamethonium into the DMV and was terminated by bilateral vagotomy. In animals pretreated with nicotine 200 nmol intracerebroventricularly (icv) administered once a day for 5 days, nicotine 100 nmol administered icv induced the decrease but not the increase in gastric motility. In conclusion, nicotine activates nicotinic receptors in the DMV and a resultant vagally-mediated dual change in gastric motility occurs. Furthermore, gastric inhibitory mechanisms in the DMV are susceptible to nicotine more than the excitatory mechanisms, and desensitization to nicotine occurs easily in the excitatory mechanisms.

Animals↗
PubMed1993

[Urethral condyloma acuminatum with severe dysplasia in a male patient detected human papillomavirus type 11: a case report].

We report a case of urethral condyloma acuminatum with severe dysplasia detected human papillomavirus (HPV) type 11. A 47-year-old male patient visited St. Luke's International Hospital complaining of tumor at the urethral meatus. One small papillary lesion was found and excised. Histopathological examination revealed condyloma acuminatum with severe dysplasia. Immunohistochemical detection for HPV antigen in the specimen of condyloma acuminatum was positive and that of severe dysplasia was negative. In an electron microscopical study, viral particles were demonstrated only in the specimen of condyloma acuminatum. Detection of HPV DNA was performed using in situ hybridization (ISH) and southern blot hybridization (SBH). HPV type 11 was found in both lesions. In conclusion, although previous studies have shown that HPV type 16/18 was especially correlated with genital severe dysplasia and carcinoma, the process of malignant transformation was suggested in the association with HPV type 11.

Condylomata Acuminata↗
PubMed1993

[The significance of 201Tl/123I MIBG (metaiodobenzylguanidine) mismatched myocardial regions for predicting ventricular tachycardia in patients with idiopathic dilated cardiomyopathy].

123I-MIBG (MIBG) regional defects in myocardial regions with preserved 201Tl (Tl) uptake have been observed in patients with idiopathic dilated cardiomyopathy (DCM). To evaluate whether the presence of Tl/MIBG mismatched regions is related to the occurrence of ventricular tachycardia (VT), we performed myocardial dual SPECT imaging with Tl (111 MBq) and MIBG (111 MBq) in 17 patients with DCM, 11 (Gp A) with and 6 (Gp B) without VT. Myocardial dual SPECT imaging was performed at 15 minutes after and 4 hours after the tracer injection. The regional tracer uptake was scored visually in 6 segments of the basal, middle, and apical short-axial images and in 2 apical segments of the midventricular vertical long-axial image by a four-point scoring system (0 = normal, 1 = moderate, 2 = severe and 3 = complete defect). Then, the severity of tracer maldistributions was assessed by the difference between total defect scores (TDSs) of Tl and MIBG (delta TDS). TDS was not different between Gps A and B in both Tl and MIBG images. However, delta TDS was larger in Gp A than in Gp B (13.5 +/- 6.5 vs. 5.8 +/- 3.0, p < 0.05). Also, the number of segments with the mismatched tracer uptake was larger in Gp A than in Gp B (12.5 +/- 3.0 vs. 8.3 +/- 1.5, p < 0.01). In the electrophysiologic study, we found that the fractionated area corresponded to the mismatched region in 3 of 5 patients in Gp A. These results suggest that regional sympathetic denervation is a possible factor which provocates VT, and myocardial dual SPECT imaging with Tl and MIBG is a useful method for predicting VT in patients with DCM.

3-Iodobenzylguanidine↗
PubMed1993

Tumor necrosis factor alpha induces migration of human eosinophils.

In order to evaluate the role of tumor necrosis factor alpha (TNF alpha) in the recruitment of eosinophils and neutrophils into the tissues, we studied the effect of TNF alpha on the migration of those cells in vitro, employing a modified Boyden's chamber technique. TNF alpha induced a significant migration of human eosinophils in a dose-dependent manner, and the preincubation of eosinophils with TNF alpha enhanced platelet activating factor (PAF)-induced eosinophil migration. Checkerboard analysis revealed that the eosinophil migration induced by TNF alpha was mainly due to chemokinesis. On the other hand, TNF alpha induced neither neutrophil migration nor enhancement of PAF-induced neutrophil migration. These results indicate that TNF alpha possesses a chemokinetic effect on human eosinophils and that TNF alpha augments the migration of eosinophils by PAF.

Chemotaxis, Leukocyte↗
PubMed1993

[The analysis of factors contributing to the safety and efficacy of rush immunotherapy in bronchial asthma].

In order to establish guidelines for the optimal use of rush immunotherapy (RI) in mite-sensitive adult bronchial asthmatics, we clinically analyzed 38 cases treated with RI. In all cases, it was possible to reach a maintenance dose greater than 0.10 ml of 1/10 solution of house dust (HD) within 10 days. Most of the systemic reactions occurred after doses greater than 0.15 ml of 1/10 solution. The patients who showed the maximum size of skin reaction > or = 8 cm were susceptible to systemic reactions. Prior to the occurrence of asthma, most cases complained of some prodrome of airway irritation. The clinical efficacy of RI was significantly lower in patients whose FEV1% was < 70%, and no difference was observed between patients whose maintenance dose was 0.10 ml and those whose maintenance dose was greater than 0.20 ml. These results suggest: 1) RI should be performed on patients whose FEV1% is > or = 70%, 2) 0.10 ml of 1/10 solution is an optimal dose, 3) when a local skin reaction is > or = 8 cm in diameter and/or a prodrome of airway irritation occurs, one should be careful when increasing the dosage.

Adolescent↗
PubMed1993

[Improvement of intractable nocturnal asthma treated by therapeutic awakening].

A 33-year-old female was admitted to our hospital because of intractable asthma which had not been improved by intensive treatment at another hospital. Her asthmatic attacks were improved within a week by treatments including systemic corticosteroids and mechanical ventilation. However, in a few weeks nocturnal asthma recurred frequently, and it was resistant to various bronchodilators and steroids. Therapeutic awakening, that is, awakening the patient quietly at 3 a.m. with inhalation of 2.5 mg salbutamol was started. Her symptoms and physical findings rapidly improved thereafter. It was concluded that therapeutic awakening may be effective for the treatment of refractory morning dipping of asthma.

Adult↗
PubMed1993

[Clinical experience with continuous warm blood cardioplegia].

We applied the Continuous Warm Blood Cardioplegia (CWBC) as an approach to improve myocardial preservation. From March to June in 1992, we used the CWBC in six patients and the conventional cold crystalloid cardioplegia (CCCP) in seven patients. All of them underwent isolated coronary artery bypass grafting. There was no marked difference between the CWBC and CCCP in post operative serum level of creatine kinase (MB type), cardiac output and dose of dopamine during they weaned from cardiopulmonary bypass. All patients treated with CWBC spontaneously restored the normal sinus rhythm shortly after removal of the aortic crossclamp, which was distinct from the fact that the CCCP group showed no such recovery. This result suggest that CWBC kept high-energy phosphate level without disturbing production of ATP in myocardium. Furthermore, reperfusion injury was also likely to be prevented by CWBC.

Aged↗
PubMed1993

Survival ability of clinical isolates of methicillin-resistant Staphylococcus aureus.

The survival abilities of methicillin-resistant strains of Staphylococcus aureus were compared with those of sensitive strains. Absorbent cotton was inoculated with 10(8) cells of each strain tested and stored at 30% humidity at 25 degrees C. The numbers of cells of sensitive strains decreased significantly to well below those of resistant strains after 4 weeks, while cells of resistant strains remained above 10(3) after 14 weeks.

Anti-Bacterial Agents↗
PubMed1993

Anomalous origin of the left coronary artery from the pulmonary artery. New operative technique.

We report a new operative technique for repair of anomalous origin of the left coronary artery from the pulmonary artery. The principles of the proposed technique are left main coronary angioplasty using a transected main pulmonary artery, side-to-side anastomosis of the aorta and newly created left coronary artery, and direct anastomosis of the transected pulmonary artery. No prosthetic material is used in this procedure. Our experience in two adults (a 35-year-old man and a 68-year-old woman) indicated that this technique permits two coronary system repair for any anatomic variation of the left coronary artery without the use of prosthetic material. This is more advantageous in infants.

Adult↗
PubMed1993

[Coronary artery bypass surgery in patients with poor left ventricular function].

As the indications for coronary artery bypass grafting (CABG) among patients with poor left ventricular function remain incompletely defined, We undertook the study to assess the results of CABG surgery for a group of such patients. We retrospectively reviewed the clinical features and outcome for 7 patients with poor left ventricular function defined as an ejection fraction below 0.3 who underwent CABG. The mean age of the patients was 63 years (range, 38 to 78 years), and 4 were 70 years of age or older. All patients had history of previous myocardial infarction, and all had left main trunk stenosis or left main equivalent stenosis. The patients underwent CABG with three to six distal anastomoses (mean, 4.3/patient), the internal thoracic artery could be used in all patients, for one or two distal anastomoses (mean, 1.6/patient). Combined coronary endarterectomy was performed in 2 patients. With the exception of one 78-year-old patient with renal failure who died during the early postoperative period, all patients showed marked postoperative improvement in cardiac function. Cardiac catheterization and exercise stress test studies revealed significant improvement in left ventricular function and exercise tolerance in these six patients. These results suggest that excellent results can be obtained with CABG surgery in patients with poor left ventricular function when the viability of the myocardium in the bypassed area has been confirmed.

Adult↗
PubMed1993

[The influence of rush immunotherapy on the production of interleukin-5 from mononuclear cells].

We investigated the influence of rush immunotherapy (RI) on the production of interleukin (IL)-5 from peripheral blood mononuclear cells (PBMC) in asthmatics sensitive to Dermatophagoides farinae (Df). The levels of IL-5 produced varied among the subjects, and these levels were not affected by the addition of Df, regardless of RI. When IL5 levels were individually compared before and after RI, some cases demonstrated an apparent decrease in production at 16 weeks after RI. It is considered that further study will be needed to confirm whether or not immunotherapy can truly suppress the production of IL-5.

Adolescent↗
PubMed1993

[Coronary artery bypass grafting surgery without cardiopulmonary bypass].

Improved technique in coronary artery surgery has allowed coronary artery bypass graftings (CABG) to be placed on beating heart. The effects of extracorporeal circulation and cardiac arrest are eliminated. From Jan. 1991 to June, 1992, we performed CABG surgery without cardiopulmonary bypass and cardiac arrest in 15 patients; the age ranged from 47 to 82 years with the mean of 65. Patients who had LAD and/or RCA stenosis were candidate of this procedure in early series. However in recent series, we extended the candidate to three-vessel or LMT stenosis cases who were considered ineligible for standard CABG because of renal failure or poor left ventricular function. Distal anastomoses were performed with interruption of coronary flow. From one to two distal anastomosis to the LAD and/or RCA (mean 1.4/patient) were performed. The ITA was used in all 15 patients. Combined cardiac or vascular operation was performed in 5 patients (AAA repair, TAA repair, carotid endarterectomy or coronary endarterectomy). There were no deaths and no perioperative myocardial infarction. Postoperative angiography were performed in 12 patients with a patency rate of 89%.

Aged↗
PubMed1992

Central noradrenergic inhibition of gastric motility in rats.

The roles of central noradrenergic mechanisms in the regulation of gastric motility were investigated in urethane-anesthetized rats in whom an intragastric balloon had been placed. Noradrenaline 100 nmol administered intracerebroventricularly (i.c.v.) significantly decreased spontaneous contractions of the stomach and this decrease in gastric motility was not observed in bilaterally vagotomized animals. Intracisternally administered (i.c.) noradrenaline (10 nmol) induced a decrease in gastric motility comparable to that elicited by noradrenaline 100 nmol i.c.v. Phentolamine 10 nmol i.c. but not the same dose of propranolol i.c. significantly antagonized the noradrenaline (10 nmol)-induced inhibition of gastric motility. These results suggest that alpha-adrenoceptor-mediated noradrenergic mechanisms in the brain stem are involved in the inhibitory regulation of gastric motility.

Animals↗