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Biomedical subjects

K Ohta

Publications and source records attributed to K Ohta.

At least 667 records · Page 37Linked to original sources
PubMed1989

Identification of a small region of the v-fos gene product that is sufficient for transforming potential and growth-stimulating activity.

To analyze the structure-function relationship for the v-fos protein, we constructed in-frame insertion and deletion mutants of the v-fos gene carried by FBJ-MuSV, and expressed them in chicken primary cells using retrovirus vectors. We assessed the effects of these mutations on the ability of the v-fos protein to transform chicken embryo fibroblasts and to stimulate cellular proliferation of chicken neuroretinal cells. The mutant which retains only the central region of the v-fos protein (Met111-Ile206) have both activities, but the mutants which have deletions in this region, and one of the mutants that has a four amino acid insertion in it, lost both activities. The central region that is sufficient for these activities includes the evolutionarily highly conserved region among human, mouse and chicken c-fos proteins. Additionally, this sequence shares some homology with the DNA binding domain of GCN4 and c-jun protein. The truncated fos protein that contains only part of the central region is not phosphorylated in chicken embryo fibroblasts, indicating that phosphorylation of the fos protein is not necessary for the transforming activity.

Amino Acid Sequence↗
PubMed1989

[Exercise induced hypoxemia and exercise tolerance in patients with COPD and the benefits of oxygen supplementation].

In order to evaluate the benefits of O2 supplementation during exercise, slowly incremental treadmill exercise tests were performed twice with 30 minutes interval rest in fourteen patients with severe COPD. The patients breathed room air. 31/min of compressed air by nasal prongs, and 31/min of supplemental oxygen in single blind fashion at random. The patients who developed arterial desaturation below 88% on exercise, group D, showed slight but significant increase in walked distance (397 m vs 424 m) and significant decrease in breathlessness (22.9 vs 16.9) on oxygen as compared to on air. On the other hand in patients without significant arterial desaturation, group S, there was no improvement in those parameters. The increase in walked distance on oxygen was closely related with the decrease in mean inspiratory flow (VT/Ti), blood lactate level, and CO2 production at identical work load. Plasma human atrial natriuretic peptide (h-ANP) levels in group D increased with exercise from a resting value of 27.6 +/- 6.9 to 44.0 +/- 9.0 on compressed air whereas the increase was significantly suppressed to 35.4 +/- 9.0 on oxygen. In group S there was no difference in the increase of plasma h-ANP levels between air and oxygen breathing during exercise (33.1 +/- 5.1 vs 31.9 +/- 9.6). A close correlation (r = 0.908) was found between mean pulmonary artery pressures and plasma h-ANP levels at rest and during exercise performed in four patients breathing air and oxygen. Those findings suggested that arterial plasma h-ANP levels reflected the right ventricular afterload and that they could be used to evaluate the effectiveness of O2-supplementation during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Serum antibody titers against various viruses in idiopathic interstitial pneumonia].

As the first step to investigate a possibility that viral infection is involved in the pathogenesis of idiopathic interstitial pneumonia (IIP), serum antibody titers against various viruses were studied in 98 IIP patients. The patients were positive for herpes simplex virus, cytomegalovirus, rubella virus, parainfluenza virus 3, EBV-VCA IgG and adeno virus 1, which were also assessed in 45 normal subjects. As results, IIP patients showed higher titers of EBV-VCA IgG (p less than 0.01). When the frequency of positive populations for each of the 6 viral antibodies was calculated, the values of the frequency in all the 6 viruses were found to be very high in both patients and normal subjects, and there was no significant difference between IIP patients and normal controls. In conclusion, a specific relationship between IIP and a certain viral infection was not observed by studying serum antibody titers against various viruses in IIP patients. It might be worthwhile studying why EBV-VCA IgG titers were shown to be significantly higher in IIP patients than in normals.

Adult↗
PubMed1989

[Indications for total gastrectomy combined with pancreaticosplenectomy in the treatment of middle gastric cancer].

Of 1725 patients with middle gastric cancer (M, MA, MC) on whom radical surgery was performed (except for absolute non-curative resection) from 1960 to 1984 at the Cancer Institute Hospital, 238 patients in whom total gastrectomy or proximal partial gastrectomy combined with pancreaticosplenectomy was carried out, were submitted for both clinico-pathological and prognostic examination. The following results were obtained: 1. There are few indications for total gastrectomy plus pancreaticosplenectomy in patients with middle gastric cancer in which the lesions are superficial or semi-superficial. 2. For patients in whom the cancer occupies portions of the greater curvature, on posterior wall of the stomach, the whole stomach, or is of a non-localized type, the metastatic rate of lymph nodes No (10) or lymph nodes No (11) is high, then total gastrectomy plus pancreaticosplenectomy should be considered. 3. Lymph nodes No (2), (4d), (4sb) (7) and (9) can be good indices indicating presence or absence of metastasis of lymph nodes No (10) and lymph nodes No (11). 4. Radical surgery as well as effective adjuvant therapy are required for gastric cancer with invasion of the serosa.

Gastrectomy↗
PubMed1989

[Clinical study of hypertensive cerebellar hemorrhage: surgical indication and measurement of volume of hematoma].

There have been a few reports available for determining surgical indications in hypertensive cerebellar hemorrhage based on volume of hematoma on computerized tomography (CT). The authors then studied the clinical results of hypertensive cerebellar hemorrhage, and the surgical indication based on clinical findings and volume of hematoma on CT scan was considered. Forty-five patients with hypertensive cerebellar hemorrhage diagnosed by CT scan who were hospitalized to Matsue Red Cross Hospital from January 1980 up to December 1986 were studied. The 25 male and 20 female patients ranged in age from 52 to 85 years, and 16 of them were operated on. The results were as follows: 1) The Kanaya's neurological grading tended to be high in the patients with cerebellar vermis hemorrhage or a large volume of hematoma (greater than or equal to 30 ml). 2) In patients with grade I or II and a moderate volume of hematoma (15-30 ml), the patient complicated with hydrocephalus should be treated with ventricular drainage. The patients with grade III and IVa should be treated with surgical therapy (suboccipital craniectomy and evacuation of the hematoma). The patients with cerebellar vermis hemorrhage should be treated with surgical therapy. The patients with a large volume of hematoma (greater than or equal to 30 ml) should be treated with surgical therapy. The patients with grade IVb and V should not be treated actively because the prognosis is bad.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Experimental focal cerebral ischemia produced by embolization with silicone cylinder in normotensive (NTR) and spontaneously hypertensive rats (SHR): comparison of neurological and pathological findings].

A focal cerebral ischemic model was produced by occlusion of the intracranial main cerebral artery with a silicone cylinder in normotensive (NTR) and spontaneously hypertensive rats (SHR). Main cerebral artery could be successfully occluded in approximately 90%. The most frequent embolized site was the distal part of the internal cerebral artery (ICb) and less frequently the horizontal segment of the anterior cerebral artery (Al). Mortality rate of NTR with ICb occlusion (NTR-ICb) was 43% at 72 hours after embolization and that of SHR with ICb occlusion (SHR-ICb) was 67% at 24 hours after embolization. NTR-ICb showed neurological signs (i.e. circling movement, hemiparesis, poor response to pain stimuli) and histologically, showed infarction in the deep cerebral structures (i.e. thalamus, hypothalamus, hippocampus, and internal capsule) accompanied with mild disruption of blood-brain barrier (BBB). SHR-ICb showed more serious neurological signs and more severe cerebral infarction in the deep cerebral structures with severe disruption of BBB. In SHR-ICb, ischemic cerebral edema was more prominent which may deteriorate symptoms and pathological findings compared to NTR-ICb. This embolization model is proposed to be useful for studying the pathophysiology of focal cerebral ischemia, especially, early ischemic edema.

Animals↗
PubMed1989

Clinical study on bacteria detected in the upper and lower respiratory tracts in patients with sinobronchial syndrome.

The authors examined bacteria to confirm the pathogenesis of sinobronchial syndrome (SBS). There were several theories such as the pus-descending, the pus-ascending, the coinciding theory and so on. Detection of bacteria was performed in SBS patients, empyema patients with no lower respiratory disease, and healthy adults. Considering SBS bacteriologically from the obtained results, the authors consider that internal infections of aerobic gram-negative bacteria of the normal flora mainly including Haemophilus influenzae possibly develop in two directions, downward and upward (into nasal cavities) from the pharynx, and so the pathogenesis of SBS might not be explained satisfactorily by either the ascending or the descending theory alone.

Adult↗
PubMed1989

[A case of dermatomyositis which rapidly developed to respiratory failure in the presence of pneumomediastinum].

A 49-year-old woman was admitted in February 1987, with a six-month history of joint pain, maculopapular and erythematous rash, proximal muscle weakness and a two-month history of skin ulceration and dyspnea on exertion. Physical examination showed Gottron's papules on her fingers and a faint heliotrope rash. Biopsy of erythematous skin lesions on the shoulder and the back of the hand revealed perivascular inflammatory cell infiltration and tiny ulcerative lesions of the cutaneous tissue. Biopsy of the right quadriceps muscle showed type II fiber atrophy and slight perivascular lymphocytic infiltrate, whereas serum CPK level was within normal range. Chest X-ray film showed granular infiltrates in both lower lung fields. Based on the current findings the case was diagnosed as dermatomyositis associated with interstitial pneumonia. The administration of prednisolone, 30 mg/day resulted in the improvement of the skin lesions and muscle weakness, while the intensity of lung infiltrates was little affected. Three months after steroid therapy, the patient was readmitted because of increasing dyspnea on exertion and multiple skin ulcers. Chest X-ray revealed a small amount of gas in the mediastinum, in addition to slight deterioration of interstitial lung disease. In spite of various treatments for pneumomediastinum, including bed rest, administration of analgesics and oxygen inhalation, it developed rapidly, complicated severe subcutaneous emphysema and right-sided pneumothorax. Although high-dose prednisolone therapy and mediastinal drainage were performed, the pneumomediastinum was not resolved and she died from respiratory failure. At autopsy, predominant histological features of the lungs were acute interstitial pneumonia with hyaline membrane and edematous granulation formation in the alveoli.(ABSTRACT TRUNCATED AT 250 WORDS)

Dermatomyositis↗
PubMed1989

[The histological type and lymphatic permeation of diffuse infiltrative carcinoma of the stomach].

Although diffuse infiltrative carcinomas of the stomach are mostly composed of anaplastic/mucocellular type, some cases show tubular/trabeculoacinar carcinoma in a large or small part of the tumor. We have subdivided diffuse infiltrative carcinoma into two subtypes, mixed type and pure type, from the viewpoint of the carcinoma's histological structure and lymphatic permeation (LP). The former, or mixed type, includes a tubular/trabeculoacinar element in at least 10% of the tumor tissue, and shows a high tendency for LP. On the other hand, the latter, or pure type, consists almost exclusively of anaplastic/mucocellular carcinoma with a low tendency for LP. No difference in the frequency of LP between males and females was found in the pure type carcinomas, but a significantly higher frequency and grade of LP was observed in males in the mixed type carcinomas. Further, even in the pure type, the LP was rather frequent in people 60 or more years old. Thus, lymphatic permeation seems to be influenced not only by the histological type of the carcinoma but also by sex and age.

Adenocarcinoma↗
PubMed1989

[A case of chronic obstructive pulmonary disease associated with central alveolar hypoventilation diagnosed by exercise test].

We report a case of chronic obstructive pulmonary disease associated with central alveolar hypoventilation diagnosed by exercise test. A 61-year-old man with chronic obstructive pulmonary disease was admitted to our hospital because of respiratory failure caused by bacterial pneumonia. After recovery from pneumonia, we examined his functional ventilatory response to incremental exercise. Exercise was discontinued because of his maximal target heart rate, and there was no complaint of dyspnea throughout the exercise test. Although the patient had enough ventilatory reserve during exercise (VEmax/MVV = 50%), there was a marked progressive retention of carbon dioxide disproportionate to the extent of his air flow obstruction. Moreover the patient was able to reduce the carbon dioxide tension to a subnormal level by voluntary hyperventilation, and his ventilatory response to carbon dioxide and mouth occlusion pressure at rest was significantly diminished as compared with normal subjects. These findings suggest that this patient has several features compatible with central alveolar hypoventilation. Exercise test was useful for the diagnosis as well as exercise prescription because the patient could develop dangerous hypoxemia without alarming symptoms like dyspnea.

Exercise Test↗
PubMed1989

A study on death of alcoholics.

Out of 1,195 alcoholics treated in a psychiatric hospital during 1974-1986, 150 patients who died were examined. In 150 subjects, 86 natural deaths and 53 violent deaths were observed. Alcoholics who died from violent causes were hospitalized 10 years earlier and also died 10 years earlier than those of natural causes on the average. Furthermore, they failed more frequently to improve their drinking habits and their deaths tended to occur immediately after discharge. They were often single and of low economic status, and these social factors were considered to be closely related to their violent death.

Adult↗
PubMed1988

Modulation of human basophil histamine release by hemopoietic growth factors.

To determine what kinds of CSF modulate human basophil function, recombinant or purified hemopoietic growth factors were tested for the effect on histamine release from basophils. Both granulocyte (G)-macrophage (M) CSF and IL-3 markedly enhanced histamine release upon stimulation with anti-IgE in a dose-dependent manner (maximal enhancement 25.5% by GM-CSF and 30.8% by IL-3 as expressed as percent increase against total cellular histamine content), whereas G-CSF, M-CSF, and IL-4 had no effect. Enhancing action of these factors was still observed in the highly enriched basophil population, suggesting that this action was not via contaminating cells. Enhancement of histamine release by both factors was not necessarily IgE mediated, because they also amplified histamine release upon stimulation with FMLP and ionophore A23187. The enhancement by both factors was temperature dependent, and took place rapidly and reached plateau levels in 15 min. GM-CSF and IL-3 achieved the similar plateau level of augmentation and no additive effects were observed between them. This finding suggests that they enhance histamine release by sharing the same pathway in the release reaction.

Adjuvants, Immunologic↗
PubMed1988

Sex-related difference in oxidative metabolism of testosterone and erythromycin by hamster liver microsomes.

The activities of testosterone hydroxylases and erythromycin N-demethylase were significantly higher in liver microsomes from female hamsters than in the male counterparts. SDS-polyacrylamide gel electrophoresis revealed a difference in protein composition between male and female liver microsomes in the molecular mass region comprising cytochrome P-450. Western blot analysis showed further that antibodies to rat male-specific cytochrome P-450 crossreacted with at least two proteins in both male and female hamster microsomes, but one of the female proteins had a different molecular mass from that of the male proteins. It is concluded that sex difference in liver microsomal cytochrome P-450 is not restricted to rats and mice, as has previously been believed.

Animals↗
PubMed1988

51-kd protein, a component of microtubule-organizing granules in the mitotic apparatus involved in aster formation in vitro.

Mitotic apparatuses (MAs) isolated from sea urchin metaphase eggs were chilled on ice to depolymerize microtubules, homogenized, and incubated with tubulin. This caused formation of many small asters with microtubules focusing on granules which were probably fragments of the centrosome. The aster-forming protein components of the granules in the homogenized MAs were solubilized in 0.5 M KCl containing 50% glycerol. After dialysis against low-ionic-strength buffer solution, proteins congregated to form granular assembly capable of initiating aster formation. Phosphocellulose column chromatography enabled the separation of the aster-forming protein fraction which contained a 51,000 molecular weight protein (51-kd protein) as a major component. The protein fraction possessing the aster-forming activity was also prepared from methaphase whole egg homogenate, and the elution profile of the 51-kd protein on phosphocellulose column also coincided with that of the aster-forming activity. The granular assembly reconstituted from the phosphocellulose fraction formed asters whose microtubules show the same growth rate and length distribution as those of asters reconstructed from the granules in the homogenized MAs. Anti-51-kd protein antibody that was raised in rabbit and affinity-purified stained the center of asters which were reconstructed either from the granules in the homogenized MAs or from the granular assembly reconstituted from the phosphocellulose fraction. These results suggest that the 51-kd protein is a component in the aster-forming activity of the centrosomal component in vitro.

Animals↗
PubMed1988

Lysosomal alterations during coronary atherosclerosis in the pigeon: correlative cytochemical and three-dimensional HVEM/IVEM observations.

Lysosomal changes have been implicated as one of the major factors contributing to the progression and complications of atherosclerosis, and recently foam cell formation has been correlated with increases in several acid hydrolases. To explore at the subcellular level relationships among lesion progression, cellular lipid accumulation, and lysosomal change, atherosclerotic lesions from hypercholesterolemic White Carneau pigeons have been studied through combined ultrastructural cytochemistry and stereo (three-dimensional) high-voltage electron microscopy. Lysosomal enzyme activity in the prelesion intima and in foam cells of early lesions was in discrete lysosomes of macrophage foam cells. Foam cell lipid at the early stages was primarily (72%) in cytoplasmic droplets, which formed a three-dimensional network with the small (0.25-0.8 microM in diameter), reaction-positive lysosomes suspended at the vertices of a cytoplasmic lattice that delineated individual lipid pools. Concomitant with lesion progression and increasing complexity, foam cell lysosome number, size, and complexity increased. The complexity was characterized by lysosome lipid accumulation (60% of cell lipid) and the fusion of lysosomes to form multilobulated organelles in which the acid phosphatase reaction product typically was circumferential to the lysosomal lipid core. The involvement of lysosomes climaxed in the more advanced region of lesions with foam cells in which the bulk of cytoplasmic volume was occupied by large (15-20 microM in diameter), multicompartmental, lipid-containing lysosomes. It is suggested that this progressive involvement of lysosomes is responsible for cell and tissue necroses characteristic of advanced lesions.

Acid Phosphatase↗