Search PubMed⌕ Search

Biomedical subjects

M Nagata

Publications and source records attributed to M Nagata.

At least 415 records · Page 23Linked to original sources
PubMed1990

[The inhibitory effect of long-acting beta-adrenergic agonists, mabuterol, clenbuterol and fenoterol on "morning dipping" in patients with asthma].

We examined the inhibitory effect of the long-acting beta-adrenergic agonists, mabuterol, clenbuterol and fenoterol on "morning dipping" in ten patients with nocturnal asthma. On the first night, as a control experiment, the subjects received no beta-adrenergic agonist. On the succeeding three nights at 8:00 PM, each subject was orally administered 50 micrograms of mabuterol, 40 micrograms of clenbuterol and 5 mg of fenoterol in a randomized, crossover fashion. Pulmonary function tests (FVC, FEV1.0, PEFR, V50 and V25) were performed at 8:00 PM (just before administration of beta-adrenergic agonist), 9:00 PM, 10:00 PM, 6:00 AM and 8:00 AM. On the night when clenbuterol was administered, there was a significant inhibition of morning dipping at 6:00 AM in FVC (p less than 0.01), FEV1.0 (p less than 0.01), PEFR (p less than 0.01), V50 (p less than 0.01) and V25 (p less than 0.05) compared with the control night. On the nights when mabuterol and fenoterol were administered, there was a significant inhibition of morning dipping at 6:00 AM in FVC (p less than 0.01) and FEV1.0 (p less than 0.01) compared with the control night. Palpitations associated with clenbuterol administration were seen in two subjects. The effect of each beta-adrenergic agonist varied inconsistently among the subjects. These results indicate that clenbuterol is the most effective in inhibiting morning dipping among the long-acting beta-adrenergic agonists examined, but individualization in the choice of beta-adrenergic agonist is mandatory in order to achieve the maximum effect.

Administration, Oral↗
PubMed1990

[Is the clinical course of non-rheumatic aortic regurgitation the same as that of rheumatic aortic regurgitation?].

To determine whether non-rheumatic (NR) aortic regurgitation (AR) has the same clinical and postoperative courses as rheumatic (R) AR, we performed a retrospective study using pre- and postoperative M-mode echocardiograms in 23 patients who underwent aortic valve replacement (AVR) under myocardial protection with hypothermic cardioplegia. The etiology of AR was diagnosed by two-dimensional echocardiography. The NR-AR group consisted of nine patients including four with aortic valve prolapse (AP) and five with bicuspid valve (BV), and the R-AR group included 14 patients. Patients with preoperative end-diastolic dimensions (EDD) of less than 6.0 cm were excluded from this study. The indication for AVR was NYHA functional class III or severer. The severity of preoperative NYHA functional class was similar among these three groups. During the 18-month follow-up period (range 2-32 months), there were no post-operative deaths nor congestive heart failure. Ages at surgery ranged from 17 to 54 years; 10 (71%) of 14 patients with R-AR were 40 years old or older, while seven (78%) of nine with NR-AR were under 39 years old (p less than 0.05). The pre-operative left ventricular end-diastolic pressure (LVEDP) in patients with BV-AR was highest among these three groups (R-AR: 14.5 +/- 3.9 mmHg, AP-AR: 9.5 +/- 4.1 mmHg, BV-AR: 22.0 +/- 2.7 mmHg, p less than 0.05). There was no significant difference in pre-operative M-mode echocardiographic results, except for the end-systolic dimension (ESD) between R-AR (5.20 +/- 0.55 cm) and BV-AR (4.78 +/- 0.18 cm) (p less than 0.05). The EDD one month after AVR was still abnormal (greater than or equal to 5.4 cm) in seven of the 14 patients with R-AR, and three of the four patients with AP-AR but none of the patients with BV-ARs (p less than 0.05 vs AP-AR). All patients with pre-operative ESD of less than 5.2 cm had normal EDD one month after AVR. In conclusion, the clinical course of NR-AR is different from that of R-AR. Furthermore, AP-AR regresses more differently after AVR than does BV-AR. Therefore, it is important to consider the etiology of chronic AR in determining the timing of surgery.

Adolescent↗
PubMed1990

Immunohistochemical study on human atrial natriuretic polypeptide in the ventricle of hearts with endocardial fibroelastosis.

The presence and distribution of human atrial natriuretic polypeptide (ANP) were investigated immunohistochemically in the ventricles of hearts of 14 cases with endocardial fibroelastosis and 15 cases with noncardiac disease in children. Paraffin sections of autopsied hearts with endocardial fibroelastosis were stained with polyclonal antibodies against human alpha-ANP. Immunoreactive myocytes were clearly demonstrated in the ventricles of 10 hearts with endocardial fibroelastosis. The distribution of ANP-positive cells was most frequent in the inner one-third of the left ventricle. No ANP immunoreactivity was detected in any heart in cases with noncardiac disease. The left ventricular volume index of hearts with ANP-positive cells was larger than that with ANP-negative cells. The mean diameter of ANP-positive myocytes was greater than that of ANP-negative myocytes. These results suggest that ANP expression in ventricular myocytes is related to severe dilatation of the ventricular cavity and to development of myocardial hypertrophy in endocardial fibroelastosis.

Atrial Natriuretic Factor↗
PubMed1990

[Radionuclide assessment of cardiac involvement in patients with sarcoidosis].

This study was aimed to determine whether nuclear methods were useful for examining cardiac pathology and for making a decision of corticosteroid therapy in patients with sarcoidosis. Thirty six patients were divided into two groups; GpA consisted of 19 patients with cardiac sarcoidosis and abnormal ECG findings, and GpB of 17 patients with sarcoidosis without ECG abnormalities. Cardiac uptake of 67Ga-citrate in 2 and 99mTc-PYP in one of GpA was observed and steroid therapy resulted in the disappearance of the uptake. 201Tl-CL cardiac tomograms disclosed perfusion defects in 10 of 14 patients (71%) in GpA, including defects with redistribution in 8 of the 10 pts, but only one case in GpB. Radionuclide ventriculography using 99mTc-RBC revealed abnormal response of left ventricular (LV) function to exercise and LV dysfunction in GpA. These data suggest that nuclear study is a useful tool for diagnosing cardiac sarcoidosis, evaluating therapeutic effectiveness and long-term follow-up in patients with sarcoidosis.

Adult↗
PubMed1990

[Surgical treatment of cor triatriatum: report of four cases].

Four cases of cor triatriatum are reported. Cases 1 and 2 had IIA, case 3 had IA, and case 4 had IIIB 1 type of cor triatriatum according to Lucas-Schmidt classification. Cases 1 and 2 were diagnosed by echocardiography preoperatively. They were not performed cineangiocardiography because of pulmonary congestion. Case 3 had type IA so called classical type, which is hemodynamically identical to mitral stenosis and supravalvular stenosing ring. The clinical features are depend on the size of the communication between accessory chamber and true left atrium. As case 4, he had been diagnosed of simple atrial septal defect preoperatively, careful echocardiographic examination was essential for accurate diagnosis. In case 2 with hypoplastic left heart, secondary surgical repair is considered to be desirable followed by balloon dilatation of two atrial septal defects communicated to accessory chamber and to true left atrium. Thus, we expect development of hypoplastic left ventricle.

Adolescent↗
PubMed1990

[Clinical application of Therasonic lithotripsy treatment system for upper urinary tract calculi].

Extracorporeal shock wave lithotripsy (ESWL) using a Therasonic lithotripter was performed on 30 patients with urinary tract calculi between July, 1989 and February, 1990. The results obtained in 31 cases (one patient had bilateral renal stones) were presented. There were 22 inpatients and 8 outpatients in this series. The stone location was: renal pelvis in 15 cases, renal calyces in 10 cases, parenchyma or diverticulum of renal calyces in 3 cases, ureteropelvic junction in 1 case, and upper ureter in 2 cases. Sixteen cases (52%) became stone-free and residual stones (less than or equal to 4 mm) remained in 9 cases (overall effective rate 81%) at one month after the treatment. There were no serious complications including bacteremia and renal hematoma. We concluded that Therasonic lithotripter is useful in the management of upper urinary tract calculi.

Adult↗
PubMed1990

[Legionellosis].

Although increasing attention is being given to Legionella pneumonia in Japan, reports of solitary onset of this disease are scant in Japan. The patient, from whom L. dumoffii was isolated, was a 59-year-old male with no underlying disease. He visited our hospital because of fever and cough, and was admitted to our department for X-ray findings consistent with pneumonia. After admission, pulmonary lesions spread rapidly, and based on the suspicion of Legionella pneumonia, drugs such as EM, RFP and MINO were used. However, the patient died on the 26th hospital day. L. dumoffii was isolated from specimens obtained by airway aspiration before death and specimens of lung abscess and airway discharge obtained during autopsy (7 specimens in total). In addition, the L. dumoffii antibody titer in the serum became elevated. This is the first case of L. dumoffii pneumonia reported in Japan. The other case was in an 81-year-old male with underlying disease. He was admitted urgently with suspected pneumonia but died on the following day. L. pneumophila serogroup 5 was isolated from autopsied lung tissue. Fatality is high for this disease, making early diagnosis and treatment with appropriate antibiotics essential. Physicians should bear in mind the possibility of this disease and request the necessary laboratory tests in suspected cases without delay.

Aged↗
PubMed1989

Destruction of pancreatic islet cells by cytotoxic T lymphocytes in nonobese diabetic mice.

Proliferation of islet-associated leukocytes occurred when isolated islets from 20-wk-old female nonobese diabetic (NOD) mice were cultured with 10 U/ml rIL-2 for 7 days. Co-culture of these leukocytes with freshly isolated islets from 6- to 8-wk-old NOD donors in the presence of 1 U/ml rIL-2 produced islet structural deformation within 24 h and islet cytolysis within 48 h. Three lines of evidence suggest that these leukocytes were composed mainly of CTL specific for islet cells. First, morphologically, these proliferating cells adhered to NOD islets at 6 h and killed islets within 48 h of culture, but these phenomena could not be observed in the other tissues from NOD mice. These islet-derived cells were cytotoxic to NOD islet cells in a 51Cr-release assay, whereas no appreciable cytotoxicity was observed when NOD Con A-induced splenic blasts or fibroblasts were used as targets. Second, a flow cytometric analysis showed that these cells consisted of 97% Thy-1.2, 69% Lyt-2, 8% L3T4, and 4% asialo-GM1-positive cells, whereas Mac-1-positive cells could not be seen in these assays. After treatment with anti-Thy-1.2 or Lyt-2 mAb and C, these cells lost their activity to lyse NOD islet cells. However, these cells still had a full killing activity after the depletion of L3T4 or asialo GM1-positive cells. Third, islet cells from BALB/c, DBA/2, and B10.GD mice which share the same H-2K Ag with NOD mice were susceptible to cytolytic activity of these cells, whereas islet cells from NON, C57BL/6, C57BL/10, and C3H mice remained intact. Furthermore, anti-Kd antibody was capable of blocking this cytolysis. These results suggest that CTL expressing Thy-1.2 and Lyt-2 phenotypes appear to recognize the islet cell Ag with the restriction of MHC class I Kd, and then destroy NOD islet cells.

Animals↗
PubMed1989

[Cellular immune dysfunction in the NOD mouse: suppression of concanavalin A-induced responses in spleen cells by activated macrophages].

It is generally accepted that T lymphocyte-mediated autoimmunity contributes to the pathogenesis of Type 1 diabetes in humans and animals. Using spleen cells from nonobese diabetic (NOD) mice, a model of human Type 1 diabetes, we have analyzed the subset of T lymphocytes by flow cytometry and investigated concanavalin A (Con A)-induced interleukin 2 (IL-2) production and cell proliferation. NOD mice showed a higher percentage of Thy1.2+, L3T4+, and Lyt2+ T lymphocytes than did control ICR mice through the whole age examined. Spleen cells from a large majority of NOD mice were found to generate very low IL-2 production and cell proliferation in response to Con A. However, a few mice preserved their responsiveness to Con A. The following reasons may indicate that macrophage-mediated suppression participates in the deficient function of NOD spleen cells. (a) Macrophage depletion from NOD spleen cells retrieved Con A-induced IL-2 production. (b) Thioglycollate-induced peritoneal exudate cells containing many activated macrophages could completely suppress cell proliferation. (c) Prostaglandin synthetase inhibitor indomethacin reversed the suppression of IL-2 production by macrophages. (d) Conversely, exogenous prostaglandins could show the partial suppression of IL-2 production. These results suggest that activated macrophages suppress the response of NOD spleen cells to Con A mostly through prostaglandins. This impairment may contribute to the pathogenesis of Type 1 diabetes in NOD mice.

Animals↗
PubMed1989

Suppressor T-cell abnormality in NOD mice before onset of diabetes.

To investigate the pathological role of suppressor T-cells in non-obese diabetic (NOD) mice, we stimulated splenic T-lymphocytes from diabetes-prone NOD mice with concanavalin A (ConA) and then evaluated their ability to suppress the lymphocyte-proliferative responses to mitogen and allogenic cells. Lymphocytes from NOD mice showed significantly less suppressor ability than did those from BALB/c mice and non-obese non-diabetic (NON) mice, the corresponding non-diabetic sister strain of the NOD mouse, both in the mitogen response and in the mixed lymphocyte reaction (MLR). We used monoclonal antibodies and flow cytometry to analyze the lymphocytic surface phenotypes, and found markedly fewer Lyt2+ T-lymphocytes (suppressor/cytotoxic T-lymphocyte) in the NOD mice than in both controls after exposure to ConA. These results suggest that suppressor T-cell activity is already depressed in NOD mice before diabetes begins and that a substantial decrease in the number of suppressor T-cells induced by ConA may explain this depressed suppressor activity. This impairment may contribute to the pathogenesis of type 1 diabetes in NOD mice.

Animals↗
PubMed1989

Dual effect of nicotine injected in the cerebral ventricles on rat gastric motility.

Intracerebroventricularly (i.c.v.) administered nicotine 50 and 100 nmol produced dual changes, an early decrease and a successive increase in gastric motility in urethane-anesthetized rats in which an intragastric balloon had been placed. These dual effects of nicotine were significantly antagonized by simultaneously administered hexamethonium i.c.v. but not by splanchnicectomy or by pretreatment with reserpine. Both atropine pretreatment and vagotomy abolished the stimulating effect of nicotine on gastric motility. Nicotine administered i.c.v. to bilaterally vagotomized rats did not affect gastric motility which was however enhanced by electrical stimulation of the vagus nerve. These observations suggest that central activation of the vagal cholinergic component results in excitation and central activation of the vagal non-adrenergic inhibitory component with i.c.v. administered nicotine results in inhibition of gastric motility. Sympathoadrenal systems and central monoaminergic mechanisms are probably not involved in the inhibitory effect of i.c.v. administered nicotine on gastric motility.

Animals↗
PubMed1989

Suppression of concanavalin A-induced responses in splenic lymphocytes by activated macrophages in the non-obese diabetic mouse.

Spleen cells from non-obese diabetic mice were found to generate low interleukin 2 production and cell proliferation in response to concanavalin A. However, some of non-obese diabetic mice maintained in the same environment preserved their responsiveness to this T cell mitogen. Non-obese diabetic mice at every age had a higher percentage of Thyl.2, L3T4, and Lyt2-positive spleen cells than did control mice, suggesting that the dysfunction of spleen cells did not depend on the number of T cells or the ratio of these subpopulations. Evidence for macrophage-mediated suppression participating in the deficient function of splenic lymphocytes in this mouse model of insulin-dependent diabetes includes: 1) the restoration of mitogen-induced interleukin 2 production after the macrophages have been depleted by silica absorption form spleen cells; 2) the complete suppression of the cell proliferation by thioglycollate-stimulated peritoneal exudate cells from non-obese diabetic and control mice, and the partial suppression by spleen macrophages from non-obese diabetic mice; 3) the reversal of the suppression of interleukin 2 production by the prostaglandin synthetase inhibitor indomethacin (0.1-1 microgram/ml); 4) the partial suppression of interleukin 2 production, conversely, by the exogenous prostaglandins E1 and E2 (2.5 x 10(-6) mol/l). These results indicate that the activated macrophages existing among the spleen cells suppress the response of splenic T cells to concanavalin A. This impairment may contribute to the pathogenesis of insulin-dependent diabetes in non-obese diabetic mice.

Aging↗
PubMed1989

Crohn disease in systemic lupus erythematosus: a case report.

A 15-year-old girl with systemic lupus erythematosus (SLE) in remission for 3 years showed abdominal pain and bloody stools. No evidence for exacerbation of SLE was obtained. An air-contrast barium enema examination and colonoscopy revealed findings typical of Crohn disease. Despite the rarity of the combination, patients with SLE showing gastrointestinal manifestations might need evaluation for Crohn disease.

Adolescent↗
PubMed1989

Clinical and pathological status of mesectodermal leiomyoma of the ciliary body. A case report and review of the literature.

The case of a 28-year-old woman with a well-vascularized, yellowish neoplasm in her right eye is reported. The findings upon slit-lamp examination and fluorescein iridography strongly suggested a malignant lesion. The tumor and the adjacent portion of the iris, angle structures, ciliary body, cornea, and sclera were removed en bloc under the half-thickness corneoscleral flap. On the basis of light-microscopic studies, the tumor was suspected to be a neurogenic or glial tumor but further studies confirmed it to be a mesectodermal leiomyoma of the ciliary body. Electron-microscopic studies revealed the smooth muscle nature of the tumor. Because of the high percentage of benign lesions in this site, we believe that even though examinations may suggest malignancy, excision of the tumor should be preferred to enucleation of the globe in cases of ciliary tumor.

Adult↗