Search PubMed⌕ Search

Biomedical subjects

T Okada

Publications and source records attributed to T Okada.

At least 757 records · Page 42Linked to original sources
PubMed1991

In vitro growth pattern of myeloma cells in liquid suspension or semi-solid culture containing interleukin-6.

We examined in vitro growth pattern of myeloma cells from 21 patients with multiple myeloma either in liquid suspension or methylcellulose semi-solid culture, both in the presence of interleukin-6 (IL-6). The survival or growth of myeloma cells in liquid culture was classified into four categories. Type 1: myeloma cells survived for only 2-3 weeks in eight patients; Type 2: survival for 1-2 months in seven patients; Type 3: survival for more than 3 months without an obvious increase in cell number in three patients; and Type 4: continuous proliferation (cell line) in three patients. As the clinical stage advanced, the survival of myeloma cells became longer. All three myeloma cell lines were obtained from patients in an advanced clinical stage. Human plasma added to the liquid culture induced the survival or growth of myeloma cells better than fetal calf serum in any survival or growth type. Myeloma colonies or clusters were generated in seven of 21 patients, though myeloma colony formation was restricted to Type 4 patients. IL-6 neither prolonged the survival of myeloma cells nor promoted their growth in vitro except for Type 4 cells. Moreover, IL-6 did not increase the success rate of generating myeloma colonies in vitro. However, IL-6 did elevate the number of myeloma clusters in Types 1, 2 and 3 patients examined. These results suggest that IL-6 has a minor proliferative effect on myeloma cells in semi-solid culture but not in liquid suspension culture except for cells from patients with aggressive myeloma.

Cell Division↗
PubMed1991

[Comparison of noninvasive techniques in evaluation of the Björk-Shiley and the St. Jude Medical valve prostheses in mitral position].

Pressure gradients and left ventricular function were assessed by Doppler echocardiography in 50 patients with Björk-Shiley mitral valve and 50 patients with St. Jude Medical valve prosthesis. There was correlation between pressure gradient and valve size, and between effective valve orifice area and valve size for St. Jude Medical valve. These correlations were not found in Björk-Shiley valve. Clinical improvement and cardiac function were quite satisfactory in 20 patients with Björk-Shiley valve and in 32 patients with St. Jude Medical valve whose pressure gradients were less than 10 mmHg. Twenty eight of 50 patients with Björk-Shiley valve and 42 of 50 patients with St. Jude Medical valve showed good response to the exercise test. Eight patients underwent reoperation because of unacceptably high gradient caused by thrombus and pannus formation. The patients who show high pressure gradient across the valve prosthesis should be followed up cautiously.

Cardiac Volume↗
PubMed1991

[Age-related changes of auditory event-related potential (P300) in children].

Auditory event-related potentials (ERPs) were recorded from 53 neurologically normal children of 5 to 15 years of age, and 8 healthy adults. To clarify the developmental changes and to obtain a normative value in childhood, the latency and amplitude of ERPs (N100, P200, N200, and P300) were examined. ERPs were elicited with the auditory oddball paradigm. P300 components were detected in all subjects. A strong positive correlation was demonstrated between latencies of two trials, and a small latency difference between trials was interpreted as being clinically unimportant. A significant negative correlation was observed between P300 latency and age during childhood (latency (msec) = -9.81 X (Age) + 459: r = 0.75, p less than 0.01). A mild negative correlation was also observed between N100, P200 and N200 latency and age. P300-topography of amplitude showed various patterns in young childhood, but in adolescence a maximum point was Pz in almost all subjects. These findings suggest that auditory ERPs can be easily measured in childhood and are useful for objective evaluation of the cognitive function.

Adolescent↗
PubMed1991

[A case of beriberi heart--with special reference to the rapid effect of fursultiamine on hemodynamics].

A 33-year-old man was admitted to Kushiro City General Hospital on February 27, 1989, because of palpitation, shortness of breath and anasarca. Eight months previously he had noted the onset of pretibial edema, which had progressed to anasarca. He had had a meal only once a day for nine months. Physical examination revealed a blood pressure of 114/46 mmHg and pulse rate of 80/min. The 3rd sound was audible. No rales in the chest and no hepatosplenomegaly were noted. Ascites, pretibial edema and anasarca were present. Vibration sensation was diminished, and the deep tendon reflexes were absent in the legs. The blood thiamine level on the 4th day of hospitalization decreased to 2.9 micrograms/dl. The red cell transketolase activity and TPP effect on the 10th hospital day were 0.76 IU/gHb and 11%, respectively. A chest roentogenogram showed pulmonary congestion and cardiomegaly (CTR 61.3%). The electrocardiogram showed non-specific T wave changes. On the echocardiogram, remarkable pericardial effusion and diffuse hypertrophy of the left ventricular wall were observed. In addition, the left ventricular wall motion showed a hyperkinetic state. On the basis of these findings, the diagnosis of beriberi heart was made. The hemodynamic study performed on the 10th hospital day showed a remarkable high cardiac output (CO) of 10.7 l/min and an extremely reduced total peripheral resistance (TPR) of 352 dynes.sec.cm-5. 15 min after intravenous administration of Fursultiamine 100 mg, CO decreased to 7.24 l/min and TPR increased to 848 dynes.sec.cm-5. Following the administration of Fursultiamine 75 mg, po/day, his symptoms and abnormal findings of clinical examination data rapidly improved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Immunochemical quantification of the airborne chironomid allergens].

We collected airborne particles in the air using a high-volume air sampler, and measured chironomid allergen in the air-filter extract by use of RAST inhibition assay. The results obtained were as follows: 1) The assay revealed the presence of chironomid allergen in the air varying from 6.8 to less than 0.3 ng/m3. 2) In Toyama, seasonal fluctuations of airborne chironomid allergen demonstrated some large peaks in summer (June to August), and showed a tendency to decrease in winter. 3) There were significant correlations between airborne chironomid allergen and dry weight of chironomid midges, collected by using light traps, in all period of a week just before, 1 to 2 weeks before, 2 to 3 weeks before, or 3 to 4 weeks before air sampling. There were not significant correlations between airborne chironomid allergen and weathers (temperature, wind speed and precipitation) during or just before air sampling. 4) In Toyama, the frequency of asthma attacks in the asthmatic children with positive C.p. RAST was much increased in summer compared with that of the negative, in which the amount of airborne chironomid allergen was increased. These results show that there is large amount of chironomid allergen in the air from spring to autumn, especially large in summer, and it is related for some asthmatics to the increase of the frequency of asthma attack.

Air Pollutants↗
PubMed1991

Establishment and characterization of four myeloma cell lines which are responsive to interleukin-6 for their growth.

Four human myeloma cell lines (MM-S1, MM-A1, MM-Y1 and MM-C1) were established from patients in the terminal stage of multiple myeloma. All the cell lines were PCA-1 positive and three were CD38 (OKT10) positive. The class of cytoplasmic immunoglobulin in each of these cell lines was identical to that of the monoclonal protein detected in each patient. Epstein-Barr virus nuclear antigen was negative in all cell lines. An examination of the tritiated thymidine uptake showed that all four cell lines proliferated in response to interleukin-6 (IL-6), while MM-S1 also responded to IL-5. Immunological staining with an anti-IL-6 receptor monoclonal antibody revealed the presence of receptors for IL-6 on the cells from each cell line. Three of them formed colonies dependent on IL-6 in methylcellulose semi-solid culture. All four cell lines grew better when human plasma was added as a supplement to the culture in comparison to fetal calf serum. Northern blot analysis showed that the three cell lines tested did not express IL-6 messenger RNA. These results indicate that these four cell lines are responsive to IL-6, but not by an autocrine mechanism, at least in the three lines examined.

Adult↗
PubMed1990

Central neurocytoma: report of a case.

Central neurocytoma is a rare intraventricular tumor recently accepted as a clinicopathological entity. A 21-year-old female was admitted with three-year history of episodic headaches and vomiting, and with rapid deterioration of her left vision over two weeks prior to admission. Computed tomography (CT) scan revealed a marked hydrocephalus and an isodense, mildly enhancing mass in the left lateral ventricle. On magnetic resonance imaging (MRI) scan, T1-weighted images revealed an intraventricular mass of slightly high intensity signal, which contained areas of low intensity signal representing multiple intratumoral cysts. The tumor showed a minimal enhancement with Gd-DTPA. A diagnosis of central neurocytoma was confirmed by an electron-microscopic study of a surgical specimen; there were numerous neuronal cell processes containing microtubules and dense-core vesicles, and a few small intercellular junctions were also identified.

Adult↗
PubMed1990

[Meningiomas in the elderly: analysis of 34 patients].

We have operated on 82 patients with intracranial meningiomas in the past 10 years. They ranged in age from 6 to 80 (mean 56.3), 59 patients were female and 23 were male. Thirty-four patients were 60 years of age or older. Of 82 patients, follow-up examination was possible in 71, with a mean follow-up period of 3 10/12 years. Pattern of clinical onset, location of tumors, and histology were compared among groups of approximately 59 years, 60-69 years, and 70 years approximately in age. Of 71 followed-up patients, 11 (15.5%) had expired. Operative mortality in patients aged 60 or older in this series, however, was low at 2.9%.

Aged↗
PubMed1990

[Antitumor responses after reinfusion of autologous plasma perfused over immobilized protein A: a study in patients at advanced stages of cancer].

Four patients at advanced stages of cancer (Pts.#1 and #4; breast adenocarcinoma, Pt.#2; rectal adenocarcinoma, and Pt.#3; adenocarcinoma possibly originated in the pancreas) received reinfusions of plasma perfused over protein A columns (IMURé Corporation; Seattle, Wa., U.S.A.). The treatment schedule was essentially the same as was reported by "the Protein A Clinical Trial Group" (Messerschmidt, G. L., et al.). Twice a week, patients received 230-250 ml of protein A-treated plasma. No other anticancer modality was employed. Pt.#1 received only one treatment due to increased general malaise. Pts.#2 and #4 completed 12 and Pt.#3 received 13 plasma-therapies. General malaise on the day after plasma return was a common untoward effect, which usually disappeared spontaneously in 48 hours. Pt.#2 experienced chills during the first two plasma returns. Pt.#3 complained dyspnea at the 6th treatment. Otherwise, no serious adverse effect was observed. No remarkable changes were obvious in the profile of daily blood chemistry. Tumor ulcerated to the chest wall in Pt.#1 appeared to be dried and, in parts, to be edematous or have reduced the size 16 hours after the first plasma therapy, while no changes were obvious in the skin adjacent to the tumor. In Pts.#2 and #4, there appeared to be tumors were isolated at palpation. Ascites was reduced in Pt.#3. Increases in tumor markers were retarded in Pts.#2 (CEA) and #4 (CA15-3). CA19-9 in Pts.#3 and #4 did not increase during the perfusion therapy. Histology of tumor obtained from Pt.#4 six weeks after completion of the protocol revealed disruption of the tumor structure, necrosis of the tumor cells and increased deposit of fibrous materials. No objective reduction in the tumor sizes was achieved in any of the patients, and the overall result was "PD". It appeared to be full of suggestions, however, that the autologous plasma in such amounts of 230 ml or 3,000 ml did, after extra-corporeal manipulation, cause some changes in the tumor as were revealed by macroscopic and microscopic observations.

Adult↗
PubMed1990

Effects of maternal bilateral ureteral ligation on the development of the proximal tubule of the kidney in fetal rats: morphometry and electron microscopic study.

Development of the proximal tubule in the fetal kidney was studied following ligation of both ureters of pregnant rats. The ligation was performed on days 15, 17, 19, and 21 of gestation and autopsy followed 24 hours after each operation. On fetal days 20 and 22, the proximal tubular length per unit volume (1 mm3) of whole kidney of the fetuses from the ligated mothers was significantly increased, while the ratio of total glomerular volume to total proximal tubular volume was remarkably decreased when compared to that of the fetuses from the non-ligated mothers. Apical vacuoles in proximal tubular cells were increased by the ligation on fetal days 20 and 22. These findings suggest that maternal bilateral ureteral ligation accelerates the growth and differentiation of the proximal tubule in fetal kidney, when the fetal kidney is functional in urine production.

Animals↗
PubMed1990

Analysis of MRI and SPECT in patients with acute head injury.

Traumatic lesions defined by magnetic resonance (MR) imaging were divided into two groups according to findings on computed tomography (CT). This classification reflected difference in the regional cerebral blood flow (rCBF). In the contusional lesions which CT could demonstrate, rCBF varied from hyperperfusion to hypoperfusion, while it was almost always decreased in the lesions which CT could not detect. These results suggest that the former may include a mixture of brain oedema and hyperemia and the latter may imply brain oedema. MR imaging can reveal the minor oedema which CT fails to show in patients with acute head injury.

Acute Disease↗
PubMed1990

Small bowel transit time measured by hydrogen breath test in patients with anorexia nervosa.

The gastrocecal transit time was measured in 10 patients suffering from anorexia nervosa, using a lactulose hydrogen breath test, and was compared with the orocecal transit time in 11 healthy controls. One of the 10 patients and one of the 11 controls were excluded from this study because of no discernible increase in hydrogen excretion. The transit time was significantly prolonged in patients with anorexia nervosa compared with controls (117 min +/- 31 SD vs 81 min +/- 33 SD, P less than 0.02). In addition to delayed gastric emptying, which has hitherto been well known, the small bowel transit time was considered to be prolonged in patients with anorexia nervosa. Both these abnormalities seem to contribute to the development of various gastrointestinal symptoms in patients with anorexia nervosa.

Adolescent↗
PubMed1990

In vitro and in vivo production of interleukin-6 by fetal mononuclear cells.

We examined the functional activity of cord mononuclear cells (MNCs) to produce interleukin (IL)-6 in vitro and in vivo. We stimulated fetal T-cell, B-cell, and macrophage fractions with mitogens. The supernatant of each stimulated cord cell fraction contained a comparable amount of IL-6 to that of each adult cell fraction activated similarly, suggesting functional maturity of cord MNCs' ability to produce IL-6. We then examined fetal cells' activities to produce IL-6 in response to perinatal infections, especially to intraamniotic infections (IAI). Among the cord MNCs from fetuses with IAI, macrophages were major cells producing IL-6. The serum IL-6 level in the fetuses with IAI was elevated, but it decreased to normal levels after antibiotic treatment; this finding indicates that IL-6-mediated host defense mechanisms by cord MNCs are triggered by perinatal infections.

Amniotic Fluid↗
PubMed1990

Influence of glycosaminoglycans on the collagen sponge component of a bilayer artificial skin.

A bilayer artificial skin composed of a silicone membrane and a collagen sponge layer containing glycosaminoglycans (GAGs) was first developed by Yannas and Burke. They reported that GAGs contained in the collagen sponge layer contributed to the function of the artificial skin. In an attempt to assess the effect of GAGs in the collagen sponge layer, the electron microscopic structure, mechanical strength of collagen sponges, and cell proliferation were examined in vitro, using four kinds of collagen sponges containing: no GAG, chondroitin 6-sulphate (C6S), dermatan sulphate (DER), and hyaluronic acid (HYA). The results indicated that: (1) addition of GAGs scarcely affected the mechanical structure of collagen sponges; (2) addition of C6S and DER reinforced mechanical strength, while addition of HYA did not; (3) addition of C6S and DER significantly decreased cell proliferation.

Artificial Organs↗