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Biomedical subjects

M Kataoka

Publications and source records attributed to M Kataoka.

At least 361 records · Page 20Linked to original sources
PubMed1989

Assessment of hepatic excretory function in chronic liver disease by hepatobiliary scintigraphy.

Hepatobiliary scintigraphy was performed in 23 normal subjects and 47 patients with chronic liver disease (chronic hepatitis; n = 27, liver cirrhosis; n = 20) to evaluate its availability as a test of liver function. After intravenous administration of Tc-99m N-pyridoxyl-5-methyl-tryptophan, the data were acquired for 60 min and the time-activity curves of ROIs (the heart and liver) were generated. In two compartment model simulation, the early blood clearance rate (kl), late blood clearance rate (km), hepatic uptake rate (ku) hepatic excretion rate (ke), and hepatic excretion T 1/2 were calculated. There was no significant difference in those four k values in normal and chronic hepatitis. However, in liver cirrhosis each of them, except km, was lower than in normal subjects. The kl value correlated closely with the indocyanine green plasma clearance test, whereas the ke and T 1/2 values were closely correlated with the level of serum bilirubins. Only hepatobiliary scintigraphy showed the excretory function of the liver quantitatively and the ke value was helpful in detecting hepatic excretory dysfunction early in chronic liver disease before serum bilirubins increased.

Adolescent↗
PubMed1989

Radiation-induced oesophageal stricture in a case of Bloom's syndrome.

A case of Bloom's syndrome with lung cancer treated by radiation therapy is described. Squamous cell carcinoma of the lung responded well to a tumour dose of 50.4 Gy. The most serious complication of therapy was an oesophageal stricture induced by only 30.6 Gy to the mediastinum. Brief reviews of radiation-induced oesophageal stricture and radiosensitivity in Bloom's syndrome are presented.

Adult↗
PubMed1989

Melittin binding causes a large calcium-dependent conformational change in calmodulin.

The interaction between calmodulin and its target protein is a key step in many calcium-regulated cellular functions. Melittin binds tightly to calmodulin in the presence of calcium and is a competitive inhibitor of calmodulin function. Using melittin as a model for the target peptide of calmodulin, we have found a large Ca2+-dependent conformational change of calmodulin in solution induced by peptide binding. Mg2+ does not substitute for Ca2+ in producing the conformation change. Small-angle x-ray scattering has shown that calmodulin exists as a dumbbell in solution, similar to that observed in the crystalline state. Our present measurements reveal that the overall structure of the Ca2+-calmodulin-melittin complex is not a dumbbell but a globular shape. Upon binding melittin, the radius of gyration decreases from 20.9 to 18.0 A and the largest dimension decreases from 60 to 47.5 A. In the absence of calcium, however, melittin has little effect on the solution structure of calmodulin.

Animals↗
PubMed1989

Endothelial mediation is necessary for subsequent hepatocyte uptake of transferrin.

The authors previously have reported on the presence of transferrin (TF) receptors on liver endothelial cells and have shown that hepatic uptake of transferrin-iron (TF-Fe) complexes in the liver is mediated by the endothelium. We now provide evidence that this endothelial cell mediation may be necessary for hepatocyte uptake of TF-Fe complexes. Transport of TF-Fe from endothelial cell to hepatocyte was studied in mixed cell suspensions in which radiolabeled TF-Fe complexes were incubated at 37 degrees C with the two cell populations purified and then mixed in equal ratios. The mixtures were then refractionated at various times after incubation and cell-associated radioactivities measured. Radiolabeled TF was rapidly taken up by the endothelial cell fraction, but radioactivity began to decline in this fraction as it increased in the hepatocyte fraction. In double labeling experiments with 125I-TF-59Fe, both radiolabels moved across the endothelium in parallel fashion, indicating that Fe remains associated with TF during transcytosis. However, in hepatocytes the two radiolabels became dissociated, with Fe remaining cell-associated and TF being recycled. Hepatocyte uptake of processed TF was partially inhibitable by galactan and asialofetuin, indicating that hepatocyte uptake may occur via asialoglycoprotein receptors of hepatocyte.

Animals↗
PubMed1989

Problems associated with the EEA stapling technique for esophagojejunostomy after total gastrectomy.

Since November 1980, the EEA stapling device has been used to create an end-to-side esophagojejunostomy in 238 patients who underwent total gastrectomy. Failures in the stapling technique were divided into two groups: immediate and delayed. Immediate failures were observed and corrected at the time of surgery. In ten cases, the muscular layer of the esophagus was disrupted, and in three the mucosal layer of the jejunum was disrupted. There were 18 delayed complications: eight cases of anastomotic leakage (3.4%), and ten of stenosis (4.2%). The leakage in one case was classified as major, and those in the other seven as minor. Of the ten stenosis cases, there were five of membranous stricture, four of granular stricture, and one of narrowing after major leakage healing. Only this last case required further surgical treatment. The other nine were successfully dilated either endoscopically or by bougienage.

Adult↗
PubMed1989

Asymmetric synthesis of 2-substituted-3-aminocarbonyl propionic acid.

An asymmetric synthetic route to 2-substituted-3-aminocarbonyl propionic acid, which is the significant component of low-molecular-weight renin inhibitors, is described. The key step of this synthesis is diastereoselective alkylation by using chiral oxazolidinone and benzyl bromoacetate.

Chemical Phenomena↗
PubMed1989

[Effects of total parenteral nutrition containing essential trace elements on their concentrations in rats].

Twenty-four rats were equally divided into 4 groups and maintained for 1 week as follows: Group A (normal control) with a synthetic normal diet and distilled water, group B with conventional total parenteral nutrition (TPN), i.e., TPN without essential trace elements (ETE), group C with TPN supplemented with a usual dose of ETE solution (TE-5), and group D with TPN supplemented with 3 times the usual dose of TE-5. Body weight, trace element concentrations in various tissues and certain blood biochemical parameters were determined in these rats. The results were as follows: 1) No significant differences in body weight were observed among the groups. 2) The iron concentrations in plasma and tibia decreased significantly in group B as compared with group A. The addition of TE-5 prevented these decreases, but dose-dependent increases in the concentrations of iron were observed in liver, spleen and kidney (groups C and D). 3) The zinc concentrations in plasma, whole blood, brain, heart, kidney and tibia decreased significantly in group B as compared with group A. The addition of TE-5 prevented these decreases dose-dependently (groups C and D). 4) The copper concentrations in plasma, whole blood, liver, spleen, kidney, testis and tibia decreased significantly in group B as compared with group A. The addition of TE-5 resulted in a tendency for these decreases to diminish (groups C and D). 5) The manganese concentrations of whole blood in group B decreased significantly as compared with group A. The addition of TE-5 caused the manganese concentrations of various tissues in groups C and D to increase significantly as compared with group A.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Supplementation of essential trace elements during total parenteral nutrition--effects on trace element-deficient rats].

Thirty-one male SD rats, six weeks old, were fed a trace element-deficient diet for two weeks and then divided into three groups and maintained for 1 week as follows: group A with total parenteral nutrition (TPN) without supplementation of trace elements, group B with TPN supplemented with the following 5 trace elements ... iron, zinc, copper, manganese and iodine, and group C with a diet free of the above five trace elements. Another group of eight rats was fed a diet supplemented with the above five trace elements for three weeks as a control (group D). Feeding or TPN without supplementation of trace elements evoked microcytic hypochromic anemia and significant decreases in iron concentrations in plasma and tissues (groups A and C). Supplementation of trace elements in the TPN solution showed a tendency to cure anemia and a significant increase in the iron concentration in tibia (group B). Decreases in the zinc or copper concentrations in plasma and tissues during TPN without trace elements were prevented by supplementation of trace elements in the TPN solution (group B). The plasma zinc and copper concentrations correlated well with their levels in liver, kidney and tibia. Manganese deficiency was not recognized in this investigation (groups A and C), though supplementation of trace elements in the TPN solution increased tissue manganese concentration (group B). Feeding or TPN without supplementation of trace elements induced decreases in plasma triiodothyronine and thyroxine (groups A and C). Supplementation of trace elements in the TPN solution showed a tendency to increase plasma thyroxine (group B).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Changes in trace-element concentrations after intravenous injection of an essential trace-element preparation for parenteral use in rats].

This experiment was carried out to investigate the effects of intravenous injection of an essential trace-element preparation (TE-5) on iron, zinc, copper and manganese concentrations, and blood biochemical and hematological parameters in rats. The rats were treated by intravenous injection of TE-5 for 7 days and the following results were obtained: 1) Neither a 0.04 nor a 0.4 ml/kg/day injection of TE-5 affected the iron, zinc, copper and manganese concentrations in tissues. 2) At a higher dose (1.2 ml/kg/day), iron concentrations in liver and spleen, zinc concentrations in liver, kidney, tibia and plasma, copper concentrations in heart, kidney and whole blood, and manganese concentrations in brain, heart, spleen, kidney, femoral muscle, tibia and whole blood increased. 3) At the highest does (4 ml/kg/day), all rats died and iron, zinc, copper and manganese concentrations in tissues increased remarkably. 4) With injections of TE-5 (0.04-1.2 ml/kg/day), hemoglobin, hematocrit, alkaline phosphatase activity and blood urea nitrogen decreased slightly. These results suggest that iron, zinc, copper and manganese concentrations, and blood biochemical and hematological parameters are maintained at doses up to 0.4 ml/kg/day of TE-5, but that doses higher than that destroy homeostasis.

Animals↗
PubMed1989

[An unresectable gastric cancer radically resectable following UFT, ADM, MMC therapy].

A 58-year-old woman who was inoperable because of S3 (pancreas and colon) and P1 at the initial operation was treated with UFT, ADM and MMC at a dosage of 242.7 g, 418 mg and 166 mg, respectively. After the chemotherapy (2 years and 6 months from initial operation), a second look operation revealed that a tumor was localized in the submucosal layer and there were no lymph node metastases. Thus, it could be resected radically. Until now, various methods of chemotherapy for unresectable gastric cancer have been reported, and many cases of CR contained fluoropyrimidine derivates. In the case under study, combination chemotherapy containing UFT was performed with good results.

Adenocarcinoma↗
PubMed1989

[Antibody activity to Propionibacterium acnes in bronchoalveolar lavage fluid in sarcoidosis].

While increased levels of circulating antibody to various microorganisms have been reported in sarcoidosis patients, the pathogenesis of the disease is still unknown. In this report, the levels of antibody activities against Propionibacterium acnes (P. acnes) were measured in bronchoalveolar lavage fluid (BALF) in patients with sarcoidosis, using an enzyme-linked immunosorbent assay method. Each immunoglobulin class of antibody activity to P. acnes was corrected by albumin concentrations in BALF. The levels of whole immunoglobulin antibody activities to P. acnes in BALF were as follows: 412.3 +/- 443.9 O.D./albumin 1 mg (M +/- SD) in 31 untreated sarcoidosis patients, 556.6 +/- 341.8 in 10 sarcoidosis patients treated with prednisolone, and 231.5 +/- 156.8 in 16 control individuals. The levels of antibody activities were significantly elevated in untreated patients (p less than 0.05) and in treated patients (p less than 0.02) compared to those of controls. However, considering the treated vs. untreated patients, there was no significant difference in levels. The serum levels of whole immunoglobulin antibody activities were 0.484 +2- 0.191 O.D. in 38 untreated patients, 0.410 +/- 0.166 in 13 treated patients and 0.571 +/- 0.254 in 52 controls. The levels of antibody activity were significantly lower in treated patients than in the controls (p less than 0.05). However, there was no significant difference between the untreated patients and controls. To assess the site of antibody production, the secretion ratio was calculated by dividing the levels in BALF to those in serum. For this purpose, each serum level of antibody activity was also corrected by serum albumin concentration as with BALF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Quantifying manganese in lymphocytes to assess manganese nutritional status.

To clarify whether manganese nutritional status is better reflected by the manganese concentration in lymphocytes or in whole blood, we injected manganese solutions intravenously into manganese-deficient rats and determined manganese concentrations in lymphocytes, whole blood, and various tissues. The manganese concentrations in lymphocytes and tissues, but not in whole blood, were significantly less in manganese-deficient rats than in normal rats. These low values could be prevented by intravenous injection of manganese in a dose-dependent manner. These results suggest that, for assessment of manganese nutritional status, measurement of manganese in lymphocytes is better than that in whole blood.

Animals↗
PubMed1989

[Interleukin-2 production and receptor expression of alveolar lymphocytes stimulated by Propionibacterium acnes in sarcoidosis].

We previously reported that alveolar lymphocytes in patients with active sarcoidosis are sensitized to Propionibacterium acnes (P. acnes) which may play a significant role in the induction of alveolitis in these patients. However, the mechanism of lymphocyte activation is not fully understood. In this study, we further investigated the production of Interleukin-2 (IL-2), and the responsiveness to IL-2 of alveolar lymphocytes obtained from sarcoidosis patients and stimulated by P. acnes in vitro. In 21 untreated sarcoidosis patients, 7 treated patients and 13 control subjects, the mean IL-2 activity of fluid released from cultured alveolar lymphocytes was 9.8 +/- 15.7 u/ml (M +/- SD), 1.9 +/- 4.7 u/ml and 0.2 +/- 0.8 u/ml respectively. The IL-2 activity of lymphocytes from untreated patients was significantly higher than that of control subjects (p less than 0.02). The responsiveness of alveolar lymphocytes to recombinant IL-2 was evaluated by 3H-thymidine uptake in the presence and absence of P. acnes. Lymphocytes stimulated by P. acnes showed a significantly increased uptake (3766 +/- 3929 dpm) compared to unstimulated lymphocytes (1123 +/- 968 dpm) obtained from 11 untreated sarcoidosis patients (p less than 0.02). On the other hand, the responsiveness of lymphocytes obtained from 6 control subjects was low, regardless of stimulation by P. acnes. There was a significant correlation (p less than 0.05) between the P. acnes-induced production of IL-2 by alveolar lymphocytes and the blastogenesis of alveolar lymphocytes in untreated sarcoidosis patients. Our data indicate that P. acnes stimulates IL-2 production and IL-2 receptor induction in alveolar lymphocytes from patients with active sarcoidosis.

Adult↗
PubMed1989

[The response of alveolar lymphocytes induced by Propionibacterium acnes in pulmonary sarcoidosis: correlation with clinical studies, pulmonary function studies and bronchoalveolar lavage].

Current concepts of the pathogenesis of sarcoidosis suggest that the alveolitis in this disorder is related to increased numbers of helper T-cells within the lungs. However, the mechanism of this accumulation of lymphocytes is not known. We have reported that proliferation of alveolar lymphocytes induced by P. acnes is increased in patients with active sarcoidosis. To determine whether the response of alveolar lymphocytes would be useful in staging the activity of pulmonary sarcoidosis, we studied 34 untreated patients with this disorder, and correlated the response of alveolar lymphocytes with clinical, roentgenographic, physiologic, and bronchoalveolar lavage findings in these non-smoking patients. There was a significant correlation of the response in the numbers of lymphocytes (p less than 0.05) and CD4 (+) T-cells (p less than 0.01) recovered from the lungs of these patients by bronchoalveolar lavage. Furthermore, the response correlated significantly with the activity of Interleukin-2 released by alveolar lymphocytes stimulated by P. acnes (p less than 0.05). In contrast, no correlation was found between the response and the clinical, roentgenographic, or physiologic data. However, in patients who showed abnormality in all three clinical examinations, i.e. serum angiotensin converting enzyme activity, number of alveolar lymphocytes, and 67Ga scintigraphy of the lung, the response was significantly higher than in controls (p less than 0.001) or in patients with none of these abnormalities (p less than 0.01). Also, the response in patients with an abnormality in two of these three examinations was significantly elevated compared to that in normals (p less than 0.025) or in patients without an abnormal examination (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Temperature dependence of the structure of aggregates of tobacco mosaic virus protein at pH 7.2. Static synchrotron small-angle X-ray scattering.

The small-angle X-ray scattering (SAXS) method using a synchrotron radiation source was applied to the study of the self-aggregation process of tobacco mosaic virus protein (TMVP) at a concentration of 5.0 or 12.0 mg ml-1 in 50 mM or 100 mM-phosphate buffer (ionic strengths approx. 0.1 and 0.2, respectively) at pH 7.2 in the temperature region of 4.8 to 25.0 degrees C. This paper presents the results of static measurements of SAXS. Sedimentation velocity experiments were performed simultaneously under the same conditions. These results are qualitatively parallel to those of the SAXS measurements, although the size of stacked disks derived from the SAXS measurements is larger than that derived from the sedimentation experiments, suggesting a change in the equilibrium conditions in the centrifugal field. Qualitative analysis of the SAXS data with model simulation calculations implies that the aggregation of TMVP consists of two steps: (1) the aggregation of A-protein comprising a few subunits to form double-layered disks; and (2) the random polymerization of double-layered disks by disk-stacking. Increase in temperature, ionic strength or protein concentration induced TMVP to polymerize to form a double-layered disk or a quadruple-layered short rod with consumption of A-proteins, accompanied by a small number of multi-layered short rods. The SAXS results indicate that the A-protein and the multilayered short rods are polydisperse with respect to size and shape, i.e. the mixture of A-protein, double-layered disks and multi-layered short rods coexists in the equilibrium state without pressure-induced partial dissociation of TMPV as observed during normal ultracentrifugation, and even under solution conditions in which the formation of double-layered disks or higher-order aggregates is favored.

Capsid Proteins↗