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Biomedical subjects

K Machida

Publications and source records attributed to K Machida.

At least 55 records · Page 3Linked to original sources

[Thromboxane A2 synthetase inhibitor in asthma therapy].

Thromboxane A2(TXA2), a platelet aggregator and vasoconstricter, has been implicated as a potential mediator of bronchial asthma. TXA2 induces potent contraction of airway smooth muscles and airway hyperresponsiveness. OKY-046 (ozagrel hydrochloride) is a specific inhibitor of TXA2 synthetase and a new antiasthmatic agent. In a phase III study ozagrel has shown significantly higher effect in ameliorating the asthma symptoms and reduced the dose of concomitant steroid therapy compared to azelastine hydrochloride. Both basical and clinical studies showed that TXA2 synthetase inhibitor is effective on airway hyperresponsiveness. In this review the role of TXA2 synthetase inhibitor in current asthma therapy, which is based on the Japanese guideline of allergic disorders, was discussed.

Asthma

[Home oxygen therapy (HOT) in patients with pulmonary tuberculosis sequelae--comparison between patients medically treated and those surgically treated].

In Japan there are about 40,000 patients under home oxygen therapy (HOT), of whom about 30 to 40% are pulmonary tuberculosis sequelae (TBS). These patients can be divided into three groups depending on the treatments they had, Group 1: those who had medical treatments only, Group 2: those who had artificial pneumothorax, and Group 3: those who had thoracoplasties or other surgical treatments. The purpose of this study was to observe the distributions and possible differences in the survival rates among these groups. The study included 1537 patients with TBS under HOT followed at National Hospitals and Sanatoriums nationwide in Japan. In 819 patients the treatments were specified and of those 354 were in Group 1, 29 in Group 2, and 436 in Group 3, so that the proportion of surgically treated patients in PTS was estimated between 28.4% (436/ 1537) to 53.2% (436/819). The ages at the onset of tuberculosis, at the start of HOT and the intervals in between were 36.6, 66.2 and 29.8 in Group 1, and 26.8, 65.5, and 38.1 in Group 3 respectively. Though the ages at the start of HOT were the same, those at the onset of tuberculosis were about ten years younger in Group 3 than in Group 1. Comparing Group 1 and 3, the survival rates after the initiation of HOT (Kaplan-Meier method) was better in Group 2 (surgically treated) than in Group 1 (medically treated). It is speculated that the reason could be a better preservation of the function of the remaining lung in the surgically treated and a higher incidence of obstructive impairments in the medically treated patients.

Adolescent

[Survey for hepatitis in an isolated endemic area].

Mass health screening for liver disease was conducted in A.H areas in N Town which is known to be an endemic area for hepatitis since 1985. Subjects were about 1,000 inhabitants in A.H areas and 1795 inhabitants in non-endemic areas (control) 6 years or older in age. Informed consent was obtained from all inhabitants. All subjects were interviewed for demographic data including age, sex, occupation past medical history, surgical operation daily intake of alcohol, folk use of remedies such as acupuncture and family history of liver disease. Body weight and height were also recorded. Blood obtained from all individuals was analyzed for liver function enzyme and hepatitis virus markers including anti-HCV and HBV markers. Furthermore, health education on how to prevent hepatitis and how to treat liver diseases was provided. The results were as follows. 1. Overall, the prevalence of anti-HCV was 24.1% in A.H areas, and increased in older individuals over 50 years old. To the contrary, it was 2.3% in control areas. The prevalence of HBsAg was the same in both areas. 2. Prevalence of history of surgical operations, blood transfusion and acupuncture were similar in A.H. area sand control area. 3. Risk factors for HCV infection were blood transfusion, acupuncture, history of liver diseases and anti-HBs positive. 4. Death rate due to liver cirrhosis and hepatocellular carcinoma has been increasing year by year during recent years.

Adolescent

Rapid identification of Streptococcus pneumoniae by PCR amplification of ribosomal DNA spacer region.

Streptococcus pneumoniae is one of the important human pathogens in clinical microbiology. A polymerase chain reaction assay was designed to detect and identify S. pneumoniae through amplification of the ribosomal DNA spacer regions between the pneumococcal 16S-23S ribosomal RNA genes. Thirty-two Streptococcus and non-Streptococcus strains were tested to verify the specificity of the assay, and only S. pneumoniae strains gave a positive reaction. This method is a powerful technique for the rapid identification of S. pneumoniae.

Bacteriological Techniques

Effectiveness of lower-level voluntary exercise in disease prevention of mature rats. I. Cardiovascular risk factor modification.

To evaluate the chronic effects of voluntary exercise at lower levels on primary cardiovascular risk factors, inactive strain male Fischer rats were housed either with or without free access to activity wheels under controlled environmental conditions. The average amount of exercise for the 35-week duration was 722 (SD 362) m.day-1.rat-1, which was among the lowest found in the existing reports. Nonetheless, the body mass gains of the exercising rats were markedly inhibited, being 13% less (P < 0.001) than those of the sedentary controls, despite a 22% increase in food consumption (P < 0.0001), suggesting a remarkable prevention of adiposity. A noticeable improvement of serum lipid profiles was also found; a 53% reduction in triglyceride concentrations (P < 0.01) and a 13% increase in high density lipoprotein cholesterol concentrations (P < 0.05). In addition, resting systolic blood pressure was lowered by 7% (P < 0.01). These results would suggest that even lower-level physical activity, if continued regularly, will attenuate the age-related development of cardiovascular risk factors associated with a sedentary lifestyle.

Aging

An approach to cerebral vasodilatory capacity in unilateral and bilateral cerebrovascular diseases using radiolabeled human serum albumin.

The acute cerebrovascular response to acetazolamide was assessed using a blood pool agent and planar dynamic imaging to evaluate cerebral vasodilatory capacity. Ten normal subjects and 12 patients with unilateral or bilateral cerebrovascular disease were studied. After the injection of radiolabeled human serum albumin, dynamic imaging of the anterior view of the head was started. Ten minutes later, 1000 mg of acetazolamide was infused. The dilatation index (the percent increase in activity at the peak response) was obtained for each cerebral hemisphere. The mean dilatation index in normal subjects was 17.1 +/- 3.2% (N = 20). The value was significantly lower in patients with multiple infarcts (7.7 +/- 1.1%, N = 8, P < 0.001), and below the normal range in two involved hemispheres of five patients with unilateral occlusive carotid artery disease and in three hemispheres of three patients with moyamoya disease. It was suggested that this simple method may be useful in assessing cerebral vasodilatory capacity in both unilateral and bilateral diseases.

Acetazolamide

Rapid identification by polymerase chain reaction of staphylococcal exfoliative toxin serotype A and B genes.

A new system was designed to detect staphylococcal exfoliative toxin A (ETA) and B (ETB) genes by the polymerase chain reaction (PCR). The primer pairs for the ETA gene (eta) were 20 and 20-mer, and its PCR product was a 741-bp eta fragment, while the primer pairs for the ETB gene (etb) were also 20 and 20-mer, and its PCR product was a 629-bp etb fragment. When these primers were simultaneously used in the PCR, the two types of ET were clearly detected as two bands in an ETA and ETB double-producer using only one colony within 3 hr. We examined 66 strains of Staphylococcus aureus isolated from patients with staphylococcal scalded skin syndrome (SSSS) and compared the results obtained by ELISA and PCR. The same results were obtained for 56 of the strains, i.e., 30 strains were ETA producers, 20 strains were ETB producers, and 6 strains were double-producers. However, positive results were obtained for 5 of the 10 non-ET-producing strains. Two of these strains were judged by PCR as ETA producers and three as ETB producers. Thus, PCR is very sensitive and rapid in detecting ETA and ETB gene fragments in colonies isolated from patients with SSSS.

Base Sequence

Genetic identification of Staphylococcus aureus by polymerase chain reaction using single-base-pair mismatch in 16S ribosomal RNA gene.

Staphylococcus aureus is the most predominant and important pathogen in clinical microbiology. A DNA amplification assay using the polymerase chain reaction (PCR) was designed to identify S. aureus through a single-base-pair mismatch in the sequences of staphylococcal 16S ribosomal RNA (16S rRNA) genes. It was able to detect and identify S. aureus without requiring additional analytical techniques. Twenty-eight staphylococcal and non-staphylococcal strains were tested to verify the specificity of the assay, and only S. aureus strains gave a positive reaction. It may be possible to provide immediate and exact information for the identification of S. aureus.

Base Sequence

Serum fatty acid composition in normal Japanese and its relationship with dietary fish and vegetable oil contents and blood lipid levels.

A survey was conducted on 110 normal Japanese adults (55 men and 55 women) to determine their caloric intake, dietary fat content and its origin (animal, plant, or marine). In addition, their blood lipid levels and fatty acid compositions were examined. Men in their 30s-50s consumed 2,600-2,800 calories and 60 g of fats, while women in the same age range consumed 2,000-2,200 calories and 52-58 g of fats. In both sexes, caloric, fat, and cholesterol intakes were lower for those in their 60s but protein and crude fiber consumption remained generally unchanged. When the dietary fats were classified according to origin, men and women in their 30s were found to consume less oil of marine origin. This appeared to be the result of a western style diet for Japanese adults in their 30s. Compared with men, women exhibited lower blood lipid levels. As age increased, the total cholesterol level of the blood rose in women. Thus the blood lipid level was generally equal in the two groups in their 60s. There was a positive correlation between the blood eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and dietary consumption of fish oil. The marine/plant lipid ratio was positively correlated with the blood EPA/arachidonic acid ratio. Therefore, it was believed that the origin of the dietary fats consumed is a factor in determining the blood fatty acid profile. The linoleic acid (18:2), arachidonic acid (20:4), and 18:2 + 20:4 contents were negatively correlated to the total cholesterol level in the blood but positively correlated to the HDL-cholesterol level. Polyunsaturated fatty acids (18:2 + 20:4 + 20:5 + 22:6) were negatively correlated with the blood triglyceride level. From the findings presented above, we concluded that dietary fats not derived from animal sources should be classified into fish and vegetable oils to evaluate their dietary significance. We also noted that Japanese in their 30s consume less fish oil, indicating the western trend in their dietary lipid consumption.

Adult

Effects of roxithromycin on proliferation of peripheral blood mononuclear cells and production of lipopolysaccharide-induced cytokines.

Roxithromycin (RXM), a new macrolide antibiotic, has a 14-member macrocycline ring structure which is similar to that of erythromycin. We investigated the effects of RXM on the proliferation of peripheral blood mononuclear cells (PBMCs) and the production of interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF-alpha) by PBMCs stimulated with lipopolysaccharide (LPS). At concentrations greater than 25.0 micrograms/ml, RXM suppressed the proliferation of PBMCs stimulated with phytohemagglutinin, probably due to cytotoxicity. When the PBMCs were incubated with RXM for 7 d, the number of adherent cells (monocyte/macrophages) increased. Incubation with RXM at a concentration of 25.0 micrograms/ml induced the greatest increase (p < 0.05). IL-1 beta and TNF-alpha were present 3 h after LPS-stimulation, and IL-1 beta production reached a peak at 12 h and TNF-alpha production at between 6 and 12 h, and then their production declined. RXM (25 micrograms/ml) suppressed the production of IL-1 beta and TNF-alpha slightly during the entire course of the incubation. This suppression was dose-dependent. Anti-human granulocyte-macrophage colony-stimulating factor and anti-human macrophage colony stimulating factor antibodies had no effect on the RXM-induced proliferation of adherent cells. Suppression of the production of IL-1 beta and TNF-alpha by RXM suggested that this drug might have anti-inflammatory and immunosuppressive effects.

Anti-Bacterial Agents

[Immunological investigations on pathogenesis of staphylococcal scalded skin syndrome].

Staphylococcal exfoliative toxin (ET) is an extracellular product of Staphylococcus aureus isolated from patients with staphylococcal scalded skin syndrome (SSSS) which includes Ritter's disease, bullous impetigo and staphylococcal scarlet fever, and has been regarded as the causative agent of SSSS. The ET has not only a splitting effect at the granular layer of skin in human and mice but also an immunogenicity to human and mice. Using experimental animals and clinical specimens of patients with or without SSSS, the immunological investigation were performed and following results were obtained. 1) When some inbred and congenic resistant strains of mice were immunized with serotype A ET (ETA), they were divided into the high anti-ETA antibody producers (high responders) and the low responders. The gene controlling antibody response to ETA in mice is located in the I-A subregion in the major histocompatible complex (H-2 complex), and its function seems to be at least related to antigen recognition at the T-lymphocyte level. 2) Neonatal mice are generally susceptible to ETA regardless of their H-2 haplo-type. However, the neonatal mice born to a high-responder mother immunized with ETA were resistant to the subcutaneous challenge of ETA, but those born to an immunized low-responder mother were susceptible to the challenge. 3) The relationship between susceptibility and immune response to ETA in some mammalians could be divided into three groups: the possession of resistant skin and high production of antibody to ETA (rabbits and rats); the possession of resistant skin and low production of antibody to ETA (golden hamsters and guinea pigs); the possession of sensitive skin and various titers of antibody to ETA (humans and mice). 4) The incidence of ET producing strains of Staphylococcus aureus in various clinical specimens obtained from patients without SSSS was 12% (50 out of 418 strains) in our epidemiological investigation. The percentages of antibody to ETA in sera obtained from healthy males and females were 23% and 29%, respectively. Eventually, ET-producing strains of Staphylococcus aureus seem to be spread out wider than the microbiological result obtained from clinical specimens. 5) The mitogenic responses of lymphocytes isolated from patients with the first impetigo could be measured by using PHA, and the five-of them were in the low range, whereas lymphocytes from patients with recurrent impetigo were in the normal range on this survey. Maybe this results suggest the T lymphocyte functions of some patients with impetigo are deteriorated.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult

[Association of active pulmonary tuberculosis and malignant diseases: a clinical study].

The association of pulmonary tuberculosis and bronchogenic carcinoma has been reported by many authors, however, there are rather few studies about the association of pulmonary tuberculosis and other malignant diseases and how the latter affects the outcome of the former. Between 1980 and 1993, we had in our hospital 104 patients who had both active pulmonary tuberculosis and malignant diseases. Pulmonary tuberculosis was diagnosed at the time or after the diagnosis of malignant diseases in 74 patients, of whom 92% (68 patients) were males and 42% (31 patients) were over the age of 70. There were 23 stomach cancer (31%), and 15 lung cancer (20%). In 11 patients tuberculosis developed after the initiation of radiation and/or chemotherapy. 67 patients could be followed up for more than 6 months after the initiation of chemotherapy for tuberculosis and the negative conversion rate was as high as 95.5% at 3 months. The fact indicates that the association of malignant diseases does not influence the course of tuberculosis and that these patients could be treated safely in general hospitals, provided the diagnosis is made properly without unnecessary delay.

Adult

[Long-term study of patients with sequelae of pulmonary tuberculosis after pneumonectomy--obstructive impairment and its causes].

Changes in pulmonary function, chest X-ray films, and CT were retrospectively studied in patients with sequeae of pulmonary tuberculosis 30 years after pneumonectomy (PNX). Over more than 10 years, VC and FEV1% changed at a rate of 23.2 +/- 8.8 ml and 0.683 +/- 0.688% per year, respectively. In the patients studied 30 years after PNX (N = 30), VC was 900 +/- 210 ml, %VC 31.6 +/- 8.1%, and FEV1% was 67.2 +/- 6.8%. About half of these patients had mild airway obstruction. FEV1% was negatively related to the distance from the hilum to the diaphragm on the mid-clavicular line (on the chest films) divided by body height (r = -0.607). Therefore, we think that the airway obstruction may be due to overextension of the bronchi of middle and lower lobes. Emphysema was not found in 18 patients who had no sign of hyperinflation or herniation of the remaining lung to the PNX side on their CT, but it was found in one patient with these signs.

Adult

[Home days ratio in patients treated with long-term oxygen therapy].

The home days ratio (days at home/observation period) is an important index for evaluating the efficacy of therapy for chronic disease. To compute the home days ratio in patients treated with long-term oxygen therapy, we retrospectively studied the records of 72 consecutive patients with chronic respiratory failure who received long-term oxygen therapy from the Department of Pulmonary Medicine, Ogaki Municipal Hospital. These patients were representative of those treated with long-term oxygen therapy in terms of age, cause of hypoxemia, blood gas values, and pulmonary function. The home days ratio gradually decreased; it was 92.7 +/- 15.2% during the first year, 87.5 +/- 24.0% during the second year, and 78.5 +/- 39.7% during the third year. The home days ratios in survivors (n = 39) were greater than in non-survivors (n = 33). For the first year: 96.7 +/- 7.5% vs. 85.8 +/- 21.9%, p = 0.034; for the second year: 99.0 +/- 2.6% vs. 71.4 +/- 31.0%, p = 0.004; for the third year: 96.0 +/- 9.0% vs. 48.4 +/- 53.1%, p = 0.081, for survivors and non-survivors, respectively. These data suggest that non-survivors can be distinguished from survivors soon after the start of oxygen therapy.

Aged

[Long-term study of patients with pulmonary tuberculosis sequelae after bilateral thoracoplasty-airway obstruction and its causes].

Chest roentgenograms and results of pulmonary-function tests in patients with pulmonary tuberculosis sequelae 30 years after bilateral thoracoplasty were studied retrospectively to detect airway obstruction in these patients and to determine its causes. For periods of more than 10 years, vital capacity (VC) changed at a rate of 15.5 +/- 5.0 ml/year, and forced expiratory volume in one second as a percent of VC (FEV1%) changed at a rate of 0.546% +/- 0.380% per year (n = 13). Thirty years after thoracoplasty, the VC was 920 +/- 180 ml (%VC = 28.4% +/- 5.3%), and the FEV1% was 66.2% +/- 13.7% (n = 21). Thus, mild airway obstruction was found in about half of the cases. For each patient, the distance from the hilum to the diaphragm was measured along the mid-clavicular line on the side with fewer ribs resected, and this distance was divided by the patient's height. The results of that computation was found to be significantly and negatively related to FEV1% (r = -0.681, which suggests that longer bronchi in the lower and middle lobes on that side were associated with lower values of FEV1%. These findings are similar to those in patients with pulmonary tuberculous sequelae after total pneumonectomy. Over an average of 26 years, scoliosis, the vertebra showing the most bending, the intrapulmonary lesion, and the position of the diaphragm did not change, but the cardio-thoracic ratio increased.

Adult