Search PubMed⌕ Search

Biomedical subjects

S Komatsu

Publications and source records attributed to S Komatsu.

At least 199 records · Page 11Linked to original sources
PubMed1991

[Role of transiently accumulated neutrophils in the lung of hamster in development of pneumonia due to Mycoplasma pneumoniae].

The importance of Mycoplasma pneumoniae as a pathogen of human infectious diseases, particularly of respiratory infections, has been well recognized. However, the details of the mechanism through which lung tissue damages are produced in mycoplasmal infection has not been fully understood. It has been pointed out that beside the direct invasive process certain immunological responses to the deposited microbes are crucial in development of mycoplasmal pneumonia. In the present study, we aimed at elucidating the role of neutrophils in producing pneumonia due to Mycoplasma pneumoniae in hamsters. For this purpose, hamsters were divided into two groups; the one not pretreated and infected with Mycoplasma pneumoniae and the other immunosuppressed by 60Co irradiation and infected. A serial determination of the numbers of mycoplasmal cells recovered from the treacheal tissue and bronchoalveolar lavage fluid (BALF) and analysis of cellular components in BALFs were carried out. The severity and the nature of pathological changes produced in the lungs were evaluated and scored on the basis of microscopic findings. As a result, it was found that the numbers of mycoplasmal cells recovered from both tracheal tissues and BALFs reached maximum on the seventh day of infection in both groups and decreased rapidly. There no apparent difference was found between the two groups in number of cells recovered. In the not-irradiated control groups, the percentage of polymorphonuclear leukocytes (PMNs) in BALF was very high on the seventh day and then they were replaced by lymphocytes by the 21st day of infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effect of calcium on rat gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine.

The effect of calcium carbonate (CaCO3) on the initiation of gastroduodenal carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was examined under the conditions with and without sodium chloride. Male Wistar rats were given drinking water containing MNNG (100 mg/liter) and one of the following diets during the first 20 weeks ad libitum. Group 1 was given basal diet; group 2, diet with 10% NaCl; group 3, diet with 10% NaCl and 2.5% CaCO3; group 4, diet with 10% NaCl and 7.5% CaCO3; group 5, diet with 7.5% CaCO3. During the next 20 weeks, all groups were fed with the basal diet and tap water. The carcinogenic incidences of glandular stomach between the nonsalted diet groups, 1 and 5 (15% and 16% respectively), were not significantly different at the 40th week. The incidences in the salted diet groups 2, 3, and 4 were 59, 63, and 43%, respectively, indicating no statistical difference among them. Thus, CaCO3 showed no anticarcinogenic effect on gastroduodenal carcinogenesis. In the groups 3 and 4, however, increased incidence of duodenal cancer was observed.

Animals↗
PubMed1991

Mass screening for colorectal cancer in Japan.

A mass screening program for colorectal cancer has been conducted in Japan for several years, and the nationwide statistics showed a total of 416,382 participants in 1988. This paper describes the present status of mass screening program for colorectal cancer in Japan and related issues as follows: annual trend of the number of examinees, age distribution of examinees, screening methods, diagnostic methods, evaluation of screening accuracy for fecal occult blood tests, and screening interval.

Adult↗
PubMed1991

[Comparative analysis of Hancock and St. Jude Medical valve after mitral valve replacement].

Long term results were compared in 81 operative survivors with MVR using Hancock valve (Hancock group) and 83 using St. Jude Medical valve (SJM group). The cumulative follow-up was 709.0 patients-year (p-y) and 175.2 p-y in the Hancock and SJM groups. Twenty-four percent of the patients in the Hancock group was permanently anticoagulated, while 100% of patients in the SJM group anticoagulated. The 7-year actuarial survival rate including early mortality was 79.3 +/- 4.6% for the Hancock and 93.9 +/- 3.0% for the SJM group (p less than 0.01). The survival rate was significantly higher in the SJM group than that in the Hancock group. The 7-year actuarial event free rate of the valve-related complications in the Hancock and SJM groups were as follows; thromboembolism 88.6 +/- 3.8% vs 95.0 +/- 2.8% (NS), hemorrhage, 94.0 +/- 3.0% vs 98.7 +/- 1.8% (NS), paravalvular leak 92.6 +/- 3.2% vs 97.4 +/- 1.8% (NS), infection 93.9 +/- 3.0% vs 100% (p less than 0.05), valve malfunction 78.0 +/- 5.2% vs 100% (p less than 0.001), overall valve related complications 58.9 +/- 5.9% vs 91.1 +/- 3.5% (p less than 0.001), reoperation for valve-related complication 83.1 +/- 4.6% vs 100% (p less than 0.01). The event free rate of reoperation for valve related complication in the Hancock group was significantly lower than that in the SJM group. The Hancock valve had the acceptable antithrombogenicity, but had the limited long-term durability.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Reoperation of primary tissue failure of bioprosthesis in the mitral position].

The surgical results of 38 patients who underwent reoperation for primary tissue failure of bioprosthesis in the mitral position between May 1982 and June 1990 were analyzed to determine the risk factors affecting the hospital mortality. The type of bioprostheses requiring reoperation were Hancock valve in 21 patients, Liotta valve in 15 patients and Mitroflow valve in 2 patients. Twenty-five preoperative and perioperative variables were collected and analyzed by univariate statistics using chi 2 test or Student's test. Four of thirty eight patients died postoperatively in the hospital, yielding an overall mortality of 10.5%. The causes of hospital mortality were low output syndrome in 2 patients and multiple organ failure in 2 patients. By univariate analysis, male, NYHA IV class, prosthetic stenosis, hepatic failure, renal failure, and pulmonary failure were risk factors predictive of high hospital mortality. In spite of recent improvement of surgical technique and myocardial protection, the hospital mortality of patients with NYHA IV class and advanced organ failure still remains unacceptable. Therefore, it is essential to perform reoperation for primary tissue failure of bioprosthesis before severe myocardial decompensation occurs. To accomplish this goal, patients with bioprosthesis who survived beyond the certain time should be followed periodically using echocardiogram.

Adult↗
PubMed1991

[Surgical repair of descending aortic aneurysms--experience in 100 patients under partial cardiopulmonary bypass].

Between 1975 and 1986, 100 consecutive patients with aneurysms of the descending thoracic (84 cases) or the thoracoabdominal aorta (16 cases) underwent surgical repair. Intraluminal graft inclusion procedure was employed in principle under routine circulatory support with partial cardiopulmonary bypass. In this study, overall surgical results were reviewed, and multiple factors discriminately contributing to early results were assessed using multivariate analysis (quantification theory type II) to determine if this therapeutic modality is pertinent. Fifty-five patients had non-dissecting, 42 had dissecting aneurysms and 3 had pseudoaneurysms. Seventeen patients were treated in the emergency setting. Perioperative or early deaths occurred in 14 patients. Mortality increased with advanced age (greater than 70 years) and with atherosclerotic aneurysms, especially when they involved the entire thoracic or thoracoabdominal aorta. Operative mortality during the last 5 years of the study was 9.3%: significantly lower than the figure in the first 5 years of 28% (p = 0.0198). The incidence of renal dysfunction (7.4%) or paraplegia (2.1%) was not related to aortic cross-clamp time, and both were markedly decreased to 3.8% and 0.0%, respectively, when the cases of thoracoabdominal aneurysms were excluded. There were 8 cases of exploration for postoperative hemorrhage and 6 cases of pulmonary insufficiency requiring more than 3 days of mechanical ventilation. Prolonged bypass time was a discriminative risk factor for these two complications. Cerebral vascular accidents developed in 5 patients, three of them terminated in death. In spite of partial bypass, the factors of advanced age, atherosclerosis, and cross-clamp on the aortic arch were defined responsible for brain stroke.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Surgical treatment of pulmonary atresia with intact ventricular septum in infancy--analysis of right ventricular growth potential after pulmonary valvotomy].

Our surgical experience involving pulmonary atresia with intact ventricular septum (PPA) between the years 1981 and 1989 is reviewed. Twelve infants aged 3 days to 11 months were studied for right ventricular growth potential with angiocardiography and hemodynamics after transventricular pulmonary valvotomy (TVPV). Ten infants were divided into two groups, 5 infants (Group I) were treated with TVPV only, and the other 5 infants (Group II) required additional surgery after the initial operation (TVPV in 2 cases and TVPV with shunt in 3 cases). Post-operative RV growth potential was evaluated with right ventricular index (RVI) based on the tricuspid valve annulus, right ventricular inlet, and right ventricular outlet dimensions, and with tricuspid annular index (TVI) based on the tricuspid valve annulus normalized by aortic diameter. Follow-up (3-69 months after initial operation) studies demonstrated that the RV cavity increased in Group I (RVI of 15.75 +/- 2.92 preoperatively versus 17.00 +/- 1.57 postoperatively, TVI of 3.04 +/- 0.63 versus 3.85 +/- 0.40). In contrast, the RV cavity in Group II demonstrated a lack of growth (RVI of 9.24 +/- 2.60 versus 9.85 +/- 2.76, TVI of 1.46 +/- 0.46 versus 1.70 +/- 0.80). PPA infants with RVI greater than 11 have been treated successfully with TVPV alone, which may maximize the potential for RV growth, but infants with RVI less than 11 have not experienced RV growth + postoperatively and, therefore, have required second intracardiac operations.

Angiocardiography↗
PubMed1991

[Collins blood diluting reperfusion--an effective measure of controlled reperfusion for the heart hypothermically preserved for 24 hours in modified Collins solution].

Controlled reperfusion is assumed to provide an appropriate environment surrounding the ischemic cardiac tissue at the initial reperfusion phase. Hence, this procedure might play a key role in resuscitating the long term preserved hearts. This study was designed to assess the efficacy of the newly devised reperfusion method; namely Collins Blood Diluting Reperfusion (CBDR), for those hearts subjected to 24-hours cold (4 degrees C) storage in modified Collins (MC) solution. Coronary reperfusion is commenced with the MC solution, and the oxygenated blood is successively added to dilute this perfusate with gradual rewarming under controlled perfusion pressure. Initial reperfusate, therefore, is supposed to be a blood cardioplegia with low Ca2+ and high Mg2+ content. During this procedure, any difference in the ionic composition between the storage solution and the reperfusate is completely abolished and myocardium is free from hastiness of temperature elevation. Using an isolated isovolum contracting heart prepared with an ex vivo apparatus incorporating a support dog, each heart was reperfused by unmodified blood (Group I: n = 7) or CBDR method (Group II: n = 10) under equally controlled low perfusion pressure. There was no difference in the myocardial creatine phosphate level between the 2 groups. However, the adenosine triphosphate content, which had been depleted to 30% of the preischemic level during the 24-hour preservation period, was restored to 52.0% after CBDR procedure (p less than 0.01) and consequently to 57.9% of the control at 60 minutes after reperfusion. Group I showed a significantly lower repletion effect at this phase (41.2% control; p less than 0.05 versus group II).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1991

[Surgical treatment for aneurysms of the ascending aorta with aortic regurgitation: early and late results of simultaneous replacement of the aortic valve and the ascending aorta].

From September 1976 to January 1991, 66 patients were operated on for aneurysms of the ascending aorta with aortic regurgitation. The indication for operation was annuloaortic ectasia in 40 patients (61%) and aortic dissection in 26 (39%). Twenty-seven patients (41%) had the classical Marfan syndrome. The surgical techniques employed in this series included separate graft valve replacement (separate G/V) in 18 patients whose coronary ostia were normally placed, and composite graft replacement with coronary reimplantation (composite G) in 48 patients whose coronary ostia were displaced cephalad by the aneurysm. Nineteen patients (29%) had the concomitant operative procedures including aortic arch replacement and mitral valve repair. The early death within one month after the operation occurred in 6 patients (9.1%) comprising 2 (7.1%) in the separate G/V group and 4 (8.3%) in the composite G group. The 10-year survival rate including early death was 77% for the whole series, 70% for the separate G/V group and 79% for the composite G group. There was no significant difference in long term survival rate between the separate G/V and composite G groups. No patients required reoperation for the ascending aorta and the aortic valve in the both groups. However, six patients required subsequent operation for aneurysmal disease or dissection of the remaining thoracic and abdominal aorta. The 10-year event free rate of reoperation was 82% for the whole series, 93% for the separate G/V group and 79% for the composite G group. There was no significant difference in the reoperation event free rate between the separate G/V and composite G groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Surgical repair for aortic aneurysms in aged patients over 70 years of age].

From 1960 through 1991, 556 consecutive patients with aortic aneurysms consisting of 173 with abdominal aortic aneurysms (AAA) and 383 with thoracic aortic aneurysms (TAA) were treated surgically. No significant differences were observed in the early mortality rate after AAA or TAA repair between the aged (41 TAA, 52 AAA) and non-aged groups. The 5-year survival rate of aged patients with TAA (47.3 +/- 8.5%) was significantly lower to that of non-aged patients (67.4 +/- 2.8%). However, the 5-year survival rate of aged patients with AAA (63.9 +/- 12.1%) was not significantly different from that of non-aged patients (75.9 +/- 4.3%). The asymptomatic non-ruptured aneurysms in aged-patients present many problems such as the association between surgical intervention and life expectancy, selection of patients by accurate preoperative evaluation of risk factors, and determination of the timing of operation.

Age Factors↗
PubMed1991

Protein kinase C activity and protein phosphorylation in mouse sperm.

It has been suggested that the Ca2+ and phospholipid dependent protein kinase (protein kinase C; PKC) plays some intermediary roles in the regulation of the zona pellucida-induced acrosome reaction in mouse sperm. We here demonstrated that PKC activity is in the cytosol fraction of mouse sperm and that treatment of sperm with a PKC activator, 12-O-tetradecanoyl phorbol 13-acetate (TPA), induces translocation of PKC to the membrane fraction. Treatment of epididymal sperm with 20 ng/ml TPA or 20 microM of the Ca2+ ionophore A23187 did not induce any specific protein phosphorylation. However, two specific proteins, with molecular weights of 215 kDa and 35 kDa, were significantly phosphorylated when sperm were incubated with A23187 prior to TPA treatment. A similar synergistic effect of TPA and A23187 was observed in Ca2+ accumulation in sperm. We also demonstrated that exogenous PKC purified from human pancreatic cells catalyzes the phosphorylation of these two proteins in vitro as well. The present data support the idea that the activation of PKC and subsequent protein phosphorylation are involved in the regulation of the zona pellucida-induced acrosome reaction.

Animals↗
PubMed1991

[Asymptomatic thrombosed Duromedics valve prosthesis in the mitral position].

A 52-year-old woman who was suffering from easy fatigability and arrhythmia underwent MVR using a Duromedics prosthetic valve and TAP with DeVaga's technique in November 1985. She was doing well postoperatively with Warfarin, until July 1988 when cinefluoroscopy showed one of the leaflets to be immobilized in the closed position and the other with full range of motion. The patient underwent re-MVR using a St. Jude Medical prosthetic valve. She is doing well 14 months after surgery. The diagnosis and management of thrombosed bi-leaflet mechanical valve prosthesis was also discussed.

Female↗
PubMed1991

[Accuracy and clinical problems involved in the measurements of extravascular lung water, using the thermal-sodium double indicator dilution technique].

In this report, we evaluated and discussed the accuracy and the clinical problems involved in measurements of extravascular lung water volume (EVLW), using the thermal-sodium double indicator dilution technique. We measured EVLW in 2 groups, group I (normal cardiac function group) consisting of 20 patients with esophageal cancer, and group II (low cardiac function group) consisting of 27 patients with heart valvular disease. No significant difference was found between the two groups in the reproducibility (SDM/Average X 100) of measurements of Cardiac output (CO), MTT (Mean Transient Time), and EVLW. No correlation was found between circulatory parameters and the reproducibility of measurement of EVLW. So we assumed that cardiac function has no influence on the reproducibility of EVLW measurement. But the CO measured with EVLW catheter was significantly higher than that measured with Swan-Ganz catheter in group II. We thought that EVLW should be calculated using the CO measured with Swan-Ganz catheter in cases of low cardiac function. Infection, thromboembolism and bleeding after the insertion of the catheter, overload of water and sodium due to the injection of the indicator were thought to be complications of measurement of EVLW. But in our clinical cases there was no such complication.

Esophageal Neoplasms↗
PubMed1991

[A case of left ventricular rhabdomyoma in a child].

A three-year-old girl was admitted to our hospital for surgical treatment of cardiac tumor. At three days after birth, ECG showed bradycardia about 70/min. UCG revealed intracardiac tumor in left ventricle. During operation, the tumor was detected by intraoperative UCG. Left ventricle was opened and tumor was removed from interventricular septum. Histological examination revealed rhabdomyoma. Postoperative course was uneventful and she is doing well.

Child, Preschool↗
PubMed1991

[Replacement of the aortic valve and ascending aorta for annuloaortic ectasia with severe tracheobronchial compression in an elderly patient].

A 74-year-old woman with severe tracheobronchial compression caused by annuloaortic ectasia was successfully operated upon. She was admitted to our hospital because of dyspnea with syncope and chest pain. Echocardiography and a computed tomographic scan of the chest showed annuloaortic ectasia. Broncho-fiberscopy found tracheo-bronchial stenosis caused by compression of an aneurysm of the ascending aorta. AVR and supracoronary graft replacement (separate graft/valve replacement) were performed because the coronary ostia were adjacent to the aortic annulus. Postoperatively compression of the airway subsided and dyspnea disappeared.

Aged↗
PubMed1990

Demonstration of maturation-promoting and -inhibiting activities in mouse oocytes.

The microinjection of cytoplasm from mature mouse oocytes into immature mouse oocytes induced the resumption of meiosis in the presence of 100 micrograms/ml dibutyryl cyclic AMP or 100 microM 3-isobutyl-1-methylxanthine. The volume of cytoplasm injected was critical to bringing about this maturation-promoting activity in mouse oocytes, and 20 pl of cytoplasm seems to be required to overcome the inhibitory effect of cyclic AMP on oocyte maturation. Furthermore, it was demonstrated that the microinjection of cytoplasm from immature mouse oocytes into immature mouse oocytes augmented the inhibitory effect of cyclic AMP on the resumption of meiosis. These results suggest that the appearance and disappearance of maturation-promoting and -inhibiting activities appear to be dependent on the meiotic stages in the mouse oocytes.

1-Methyl-3-isobutylxanthine↗
PubMed1990

[A case having initial onset of bronchial asthma, probably induced by prolonged mycoplasmal infection, accompanied with concurrent highly suspicious chlamydial infection].

A 37-year-old man who had had no allergic history was admitted to our hospital complaining of high fever, a dry hacking cough and dyspnea. Mycoplasma and Chlamydia mixed infection was diagnosed because of increased antibody titers to simultaneous Mycoplasma pneumoniae and Chlamydia psittaci, however only the Mycoplasma pneumoniae antibody titer was not decreased during the over six months. One month after the onset, bronchial asthma was diagnosed subsequently from for the clinical symptoms of wheeze and cough. Clinical studies of the dual infection and the possibility of Mycoplasma pneumoniae as the probable antigen of bronchial asthma were discussed.

Adult↗