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Biomedical subjects

A Uchiyama

Publications and source records attributed to A Uchiyama.

At least 19 recordsLinked to original sources
PubMed1992

Suppression by interferon-gamma of tumor cell-induced increase in mesothelial permeability.

The effect of interferon-gamma (IFN-gamma) on the interaction between tumor cells and mesothelial cell layers was studied from the aspect of changes in mesothelial permeability. Mesothelial permeability was assessed as the percentage diffusion of radiolabeled albumin across the mesothelial cell sheets on Matrigel-coated filter cup assemblies. When lined gastric carcinoma cells (KATO-III) were seeded on the confluent mesothelial cell layers, the fine cobblestone appearance of the cell sheet was disrupted and mesothelial permeability significantly increased. The increase in permeability was suppressed by the addition of as little as 1 U/ml of IFN-gamma. The effect of IFN-gamma was observed when either the conditioned medium of tumor cells alone or the IFN-gamma-resistant tumor cells, K-562, was placed onto the mesothelium. The cobblestone appearance of the cell sheet was relatively well preserved in the presence of IFN-gamma. In contrast, IFN-alpha did not suppress tumor-induced mesothelial permeability. These results suggest that IFN-gamma has the potential to protect the human mesothelial cell layers against tumor cells.

Cell Communication↗
PubMed1991

A 60-kDa phosphorylated protein from fetal human bone.

A phosphorylated protein was isolated and purified from fetal human bone. Fetal and adult human bones were decalcified with EDTA, and the extract from the fetal bone was fractionated using Q-Sepharose anion exchange chromatography. The fraction containing Ser(P) was purified by Sephacryl S-200 molecular sieving and C4 reverse-phase HPLC. The purified protein had a molecular weight of 60000 on SDS-PAGE, where the protein was stained with Rhodamine-B. The amino acid composition of this protein was different from any other reported phosphorylated proteins in human bone. However, this phosphorylated protein was difficult to detect in the adult bone extract on SDS-PAGE.

Adult↗
PubMed1991

Fluorophores from aging human articular cartilage.

Human articular cartilages of various ages were digested with collagenase, and the fluorescence of the digests was measured as a function of age. At acidic pH, all collagenase-treated fractions were found to contain two main fluorophores with fluorescence maxima at 395 and 385 nm (excitation at 295 and 335 nm, respectively). Each fluorophore was isolated from the hydrolysate and its structure was deduced from spectral and chemical data. The 395/295 nm fluorophore was identified as pyridinoline, which is one of the non-reducible cross-linkages in collagen. The 385/335 nm fluorophore was identical to pentosidine, which was isolated from human dura mater and characterized by Sell and Monnier in 1989. Our results showed that the amount of pentosidine per collagen in human articular cartilage increases linearly with age (r = 0.929, p less than 0.005), while the amount of pyridinoline per collagen remained constant and was not correlated with age (r = 0.20). On the other hand, the amount of pentosidine per pyridinoline increased exponentially during life (r2 = 0.839, p less than 0.05).

Adult↗
PubMed1991

Evidence that induction and regulation of lymphokine-activated killer (LAK) activity are mediated by changes in tumour-binding potential of lymphocytes after activation by interleukin-2 (IL-2).

The changes in the tumour-binding potential of human peripheral blood lymphocytes (PBL) after activation by interleukin-2 (IL-2) was investigated by directly counting the number of lymphocytes bound to lined hepatoma cell monolayers. A significant increase in the tumour-binding potential of PBL was found after activation by more than 100 U/ml of IL-2. Maximal tumour-binding potential was achieved at 1000 U/ml of activation, and an overdose of IL-2 activation slightly decreased this potential. These changes were almost exactly the same as the changes in anti-tumour cytotoxicity as measured by a 4-hr 51Cr-release assay. In addition, the kinetics of tumour binding by lymphokine-activated killer (LAK) cells was shown to be almost identical to that of tumour cell lysis. These results thus provide evidence that induction and regulation of LAK activity are mediated by changes in tumour-binding potential of lymphocytes after activation by IL-2.

Animals↗
PubMed1991

[Eighteen-year experience of cancer immunotherapies--evaluation of their therapeutic benefits and future].

The purpose of this study is to evaluate the therapeutic benefits of cancer immunotherapies and to predict the future of these therapies. The results of our clinical trials are as follows; (1) A group of gastric and colonic cancer patients at stages III-IV treated with BCG immunotherapy showed a significant prolongation of survival period (2) A significant prolongation of the disease-free period and the survival time were observed in the PSK-treated group in a randomized clinical trial on patients with curative surgical operation for stages III-IV colonic cancer. (3) We established clinically that intracavital administration of OK-432 is a useful therapy for patients with malignant pleuro-peritoneal effusions. We found that the reduction and disappearance of effusions were observed in more than 60% of patients with this therapy and they survived significantly longer. These results indicate that the immunotherapies may be effective to prolong survival period of advanced cancer patients with improvement of their quality of life. Furthermore, a series of our studies on the intracavital OK-432 injections for malignant ascites are useful to understand the reaction of host immune system against tumor cells.

Humans↗
PubMed1991

[Anesthesia for cesarean section in patients with fetal anomaly].

Twenty-two cases of Cesarean section due to fetal anomaly diagnosed prenatally were reviewed in terms of the anesthetic managements. In 6 cases, diazepam 0.3 mg.kg-1, which provides fetal anesthesia for surgery scheduled immediately after birth, was administered intravenously to the mothers with/without fentanyl (2 general anesthesia and 4 regional anesthesia). The diagnosis of their fetuses was congenital diaphragmatic hernia, congenital cystic adenomatoid malformation of the lung, gastroschisis or omphalocele. No fetal anesthesia was performed in the other 16 cases (15 spinal anesthesia and 1 general anesthesia). Seven of their fetuses were diagnosed as hydrops. Since the general condition of the diseased newborn is known to be deteriorated after receiving various stress and aerophagia, fetal anesthesia in Cesarean delivery has the advantage of stress reduction and prevention of aerophagia. When the newborn is considered to need immediate neonatal resuscitation or intensive care including surgery, fetal anesthesia may be a choice of anesthetic technique.

Anesthesia, Obstetrical↗
PubMed1991

[Chemical burn caused by povidone-iodine].

Povidone-iodine (PVP-I) is a widely used antiseptic because of its low toxicity and high germicidal effect. A one-year-old boy who had undergone Nissen's fundoplication developed a chemical burn on his back postoperatively. The lesion was exposed to the surgical sheet immersed with a large amount of 10% PVP-I solution for 4 hours. Patch test with PVP-I (small aluminum chamber keeps a wet paper with PVP-I) revealed positive response in the patient. The same patch tests were performed in 17 volunteers. Sixteen subjects showed positive and one negative, while direct painting of a small quantity of PVP-I on skin without the chamber produced negative responses. This may indicate that prolonged exposure to wet PVP-I is harmful. It is important to use PVP-I carefully for the prevention of contact dermatitis.

Burns, Chemical↗
PubMed1990

Two methods for medical image compression.

Depending on the purpose for which a medical image is taken, some areas of it contain more clinical information than others. These areas are usually considered as regions of interest (ROI). The area outside the ROI is either the background or contains some clinical information with relative importance. In this paper we introduce two preprocessing and error-free compression routines. The first preprocessing routine, if applied to X-ray images, could result in a reconstructed image with a controllable amount of deterioration in its various areas. The second preprocessing routine is applied to X-ray CT, MR and radionuclide images prior to the compression. Its aim is to automatically detect the ROI and neglect the background. The background is replaced by an optional gray level when these images are being reconstructed. These routines were applied to a variety of medical images and relatively good compression ratios were obtained.

Algorithms↗
PubMed1988

Use of ultrasonographic risk score in the timing of operative intervention for acute cholecystitis.

Timing of operative intervention for acute cholecystitis has long been a subject of debate. However, actual or impending perforation constitutes an absolute indication for prompt operative intervention. To discriminate these cases from those undergoing observation with conservative treatment, clinical and ultrasonographic findings were reviewed and analyzed in 17 patients with acute cholecystitis. Specificity, sensitivity, and accuracy of ultrasonography in discriminating cases of acute cholecystitis, in terms of timing of operative intervention, were calculated retrospectively based on the operative findings. The risk score for each ultrasonographic finding was determined, and the total risk score was calculated for each patient. The calculated total risk score was found to be well correlated with the macroscopic appearance of the gallbladder at operation in cases of acute cholecystitis. Therefore, this score should be useful in determining the timing of operative intervention for acute cholecystitis. However, the usefulness of the variables should further be established prospectively in other patient populations.

Acute Disease↗
PubMed1988

Analysis of thallium-201 myocardial SPECT images using fuzzy set theory.

Using the fuzzy set theory, a method was developed for analyzing the extent and severity of ischemia by comparing the exercise and delayed SPECT images with Thallium-201. For each short axial image (slice) for exercise and delayed study, a defect probability matrix (DPM) is created so that it shows the severity of ischemia of myocardium in that slice. Each slice is divided into 8 equi-angle sectors, and the left ventricle (LV) also is divided into 8 equi-angle vertical sectors from apex to base. Using DPMs, the defect probability is calculated for each slice, sectors of each slice and vertical sectors of the LV. The results are displayed on a CRT by means of images, curves and histograms. They show what percentage of the area of each slice and that of the lateral, anterior, septum and inferior portions have how much defect. They provide comprehensive and easily understood information about the condition of the LV in exercise and delayed stages. Persistent and transient ischemia can be diagnosed by visual comparison of patients' curves and histograms with their corresponding normal limits.

Coronary Disease↗
PubMed1987

The distribution and propagation pattern of motor unit action potentials studied by multi-channel surface EMG.

We developed the multi-channel surface EMG system using a matrix-type of surface electrode and with the aid of digital signal processing. The subjects were 14 normals (4-50 years) and 2 patients with Duchenne muscular dystrophy (7 and 8 years). The biceps brachii and the tibialis anterior muscles were investigated. The location of the motor end-plates and the measurement of muscle fiber conduction velocity were evaluated by the time shift of bipolar EMG arrays along muscle fibers, or by the distribution map of averaged motor unit action potentials (MUAPs). The lateral extension of a motor unit could be also estimated from the changes of averaged MUAP's amplitudes in the distribution map. Moreover in the biceps of 2 patients with Duchenne dystrophy, the mean muscle fiber conduction velocities were reduced compared to normal subjects, and characteristic propagation patterns of action potentials were obtained. In the 2-dimensional or 3-dimensional distribution map of integrated monopolar EMGs, the high density area agreed with the motor end-plate band.

Action Potentials↗
PubMed1986

Isolation and chemical characterization of the phosphoproteins of chicken bone matrix: heterogeneity in molecular weight and composition.

Ethylenediaminetetraacetic acid and HCl extracts of calcified chicken bone were fractionated by a variety of techniques, including molecular sieving in guanidinium chloride, ion-exchange chromatography on DEAE-cellulose, high-performance liquid chromatography (HPLC), reverse-phase HPLC, and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Using several different experimental schemas, we isolated 14 apparently homogeneous components varying in molecular weight from approximately 150K to approximately 4K-5K. The compositions of all of the phosphoproteins were characterized by high concentrations of Asp, Glu, Ser, Gly, and Ala. Seven of the components which were analyzed contained concentrations of carbohydrate varying from approximately 4% to approximately 17%. Three of the components containing O-phosphoserine which behaved as single bands on SDS-PAGE with molecular weights of approximately 150K, approximately 90K, and approximately 70K contained Hyp and Hyl or Hyl alone and may represent covalently bonded or strongly associated collagen-phosphoprotein complexes or hydroxylated Pro and/or Lys residues of the phosphoproteins. The findings that the amino acid compositions of several of the components were very similar and that N-terminal partial amino acid sequences of the approximately 90- and approximately 60-kilodalton (kDa) and of the approximately 150- and approximately 32-kDa components, respectively, were identical make it clear that some of the lower molecular weight components are derived by proteolysis from higher molecular weight species. In addition to proteolysis, we speculate that it is possible, from the N-terminal amino acid sequence data and preliminary cross-reaction studies of antibodies to four of the phosphoproteins, that the heterogeneity observed in the phosphoprotein components may also be due in part to there being more than one independent gene product for chicken bone phosphoproteins.

Amino Acids↗
PubMed1986

Preliminary studies of the secondary structure in solution of two phosphoproteins of chicken bone matrix by circular dichroism and fourier transform-infrared spectroscopy.

The secondary structures of two phosphoproteins from chicken bone matrix of Mr approximately 15kDa and approximately 28kDa, rich in Asx, Glx, and Ser, and containing Ser(P) and Thr(P) residues, have been investigated in solution by Circular Dichroism (CD) and Fourier Transform-Infrared Spectroscopy (FT-IR). CD spectroscopy, which yields useful information on the backbone conformation of polypeptides and proteins, suggests a predominantly beta-sheet structure for the two phosphoproteins. The FT-IR spectra of the approximately 15kDa protein, which is sensitive to secondary structure and hence provides complimentary information to CD spectroscopy, are consistent with the results obtained by CD studies.

Amino Acids↗
PubMed1986

[Extraction and characterization of phosphoproteins from chicken bone].

EDTA and HCl extracts of chicken bone were fractionated by a variety of techniques, including molecular sieving, ion exchange chromatography, and high performance liquid chromatography. Six different molecular weight phosphoproteins, 13K, 14K, 15K, 28K, 33K, and 70K dalton, were obtained. Further purified fractions were isolated by extraction of single bands from SDS electrophoresis gels. The amino acid composition of these phosphoproteins suggested the origin of the lower molecular weight phosphoproteins from higher molecular weight phosphoprotein during the purification process or maturation of the animal. In those instances, however, the amino acid composition and the degree of phosphorylation varied. This suggested the existence of genetically different phosphoproteins. Molecular weight 70K fraction included collagen component, indicating some of the phosphoproteins strongly bound to the collagen of the bone matrix.

Amino Acids↗