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Biomedical subjects

M Oshima

Publications and source records attributed to M Oshima.

At least 199 records · Page 11Linked to original sources

Generation of species-specific antihemoglobin antibodies by immunization with synthetic peptides of human hemoglobin.

Four peptides (7-16 residues) representing nonconserved regions of human hemoglobin (Hb) were selected for synthesis by comparison of the amino acid sequence of human Hb with those of the most common domesticated animals. Mouse antisera resulting from immunization with the synthetic peptides were investigated for binding to a panel of animal Hbs using solid-phase radioimmunoassay (RIA). One of the peptides elicited antibodies which bound specifically to human Hb, but not to any Hb of the nonprimate animals tested. The results show that the peptide immunogen chosen on the basis of dissimilarity between regions of different species is useful for the generation of species-specific antibodies. Such antibodies could serve as valuable tools for clinical screening of fecal occult blood trait and for forensic identification of bloodstains of human origin.

Amino Acid Sequence↗

Biochemical mechanisms of aminoglycoside cell toxicity. II. Accumulation of phospholipids during myeloid body formation and histological studies on myeloid bodies using twelve aminoglycoside antibiotics.

Cultured human skin fibroblasts take up aminoglycoside antibiotics into lysosomes to form myeloid bodies. Gentamicin (GM), one such antibiotic, was taken up until the cellular concentration reached an estimated 64 mM on the 3rd day when cells were incubated with 2 mM gentamicin. The rate of release of intracellular GM was high on the first day of incubation and gradually slowed down over the next 4 d. About 50% of the GM remained in the cells even on longer incubation in GM-free medium, suggesting it may irreversibly bind to cellular components. With myeloid body formation, the cellular phospholipid content increased 1.5 times. Bis(monoacyl-glyceryl)phosphate, which is known as a marker of lysosomal phospholipid, phosphatidylcholine and phosphatidylserine showed 250, 162, and 153% increases, respectively. Sphingomyelin was not accumulated, while lysosomal sphingomyelinase was dramatically inhibited. Of 12 different aminoglycoside antibiotics, paromomycin is the most prominent myeloid body-forming antibiotic. The myeloid body-formation is not directly correlated to human nephrotoxicity. On the other hand, the number of myeloid bodies is well correlated to the affinity to the brush border membrane, suggesting that such aminoglycoside antibiotics are taken up easily through cellular endocytosis. The cytotoxic effects of aminoglycoside antibiotics may be due to by their binding to cellular organelles other than lysosomes.

Anti-Bacterial Agents↗

A new scanning method for thallium-201 myocardial SPECT: semidecubital position method.

The authors have developed a new scanning method for Tl-201 myocardial SPECT using a rotating gamma camera with 180-degree data collection. This requires a new type of imaging table on which the patient is placed in a 50-degree right semidecubital position to allow close proximity to the camera-collimator system. Using this method, attenuation by the imaging table is completely avoidable because the projected views in the left oblique directions are not obstructed by the table. In addition, the radius of camera rotation is about 25% shorter than in the conventional method. Phantom and 16 clinical studies were performed to compare the performance of conventional and semidecubital position methods. In phantom studies, tomographic images produced using the new method showed better lesion contrast and more counts in the posteroinferior wall of the heart than those produced using the conventional method. Clinically, 12 of the 16 studies showed more counts in the posteroinferior wall of the heart with the semidecubital position method than with the conventional method. The semidecubital position method is useful for Tl-201 myocardial SPECT, especially for evaluation of posteroinferior wall hypoperfusion.

Gamma Cameras↗

[The trends of hemolytic streptococci isolated from clinical specimens in hospitals in Saitama during the period of 1979-1987].

In order to analyze the trends of hemolytic streptococcal infections, we have investigated the source of clinical specimens, monthly isolation rates, and the isolation rates by sex and age o patients of 6,440 hemolytic streptococci (group A, B, C and G) isolated from clinical specimens in hospitals in Saitama during the period of 1979-1987. 1) Serological group of 6,440 hemolytic streptococci isolated from clinical specimens were 4,691 (72.9%) isolates of group A, 1,535 (23.8%) isolates of group B, 47 (0.7%) isolates of group C, and 169 (2.6%) isolates of group G. 2) The main clinical sources of hemolytic streptococci, group A streptococci were 4,243 (90.7%) isolates from throat swabs, 117 (2.5%) isolates from ear secretions, 87 (1.9%) isolates from nose secretions, and 58 (1.2%) isolates etc., group B streptococci were 647 (42.2%) isolates from urines, 446 (29.1%) isolates from vaginal swabs, 127 (8.3%) isolates from throat swabs, 118 (7.7%) isolates from semen, 55 (3.6%) isolates from urethral secretions, 13 (0.8%) isolates from blood, and 9 (0.6%) isolates from cerebrospinal fluid etc.. 3) The monthly isolation rates of hemolytic streptococci, showed that group A streptococci had a general trend by the season, that is, the highest ratio in winter and the lowest ratio in summer, group B streptococci was not influenced by the season. 4) The isolation rates by sex of patients showed that group A streptococci had no difference between male and female, however, group B streptococci showed that the isolation rate of female was higher than that of male with the ratio of 7 to 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Cerebrospinal fluid lactate in patients with diabetes mellitus and hypoglycaemic coma.

Cerebrospinal fluid (CSF) lactate and pyruvate concentrations were determined in 20 patients with diabetes mellitus but without disturbance of consciousness and five who recovered from hypoglycaemic coma. CSF lactate was slightly but significantly higher in diabetes mellitus (1.78, SEM 0.04 m mol/l) than that in 15 control subjects (1.40, SEM 0.05 m mol/l). In those who recovered from hypoglycaemic coma, CSF lactate was markedly elevated to 2.45-4.43 m mol/l. CSF glucose concentrations, however, were substantially the same between treated hypoglycaemic and diabetes mellitus groups. These findings indicate that CSF lactate levels increase with glycaemic levels in diabetes mellitus owing to enhanced glucose influx into glycolytic pathway of the brain, and also increases in treated hypoglycaemic coma probably due to mitochondrial dysfunction or damage.

Brain Damage, Chronic↗

Comparison of peptide-coating conditions in solid phase plate assays for detection of anti-peptide antibodies.

Mice were immunized with 14 free (i.e. not conjugated to any carrier) synthetic peptides representing the entire human hemoglobin alpha-chain. Antibodies against each peptide were determined using solid phase radioimmunoassay, both with free peptides and peptides coupled to a protein carrier as the coating antigen. It has been demonstrated that large improvements in the ability to detect anti-peptide antibodies were achieved in some cases by precoating the assay wells with free peptides and in other cases by precoating with peptide-protein conjugates. Sodium carbonate buffer, pH 9.6, had a favorable effect on the coating of two of the free peptides when compared with phosphate-buffered saline, pH 7.2. The assay with the plates coated with optimum peptide form (free peptide or peptide-protein conjugate) was superior in the detection of antibody binding to 9 of the peptides when compared with the assay using chemically activated plates. The results suggest that the appropriate form (conjugated or free) and conditions for immobilizing small peptides to plastic supports are not universal but will have to be determined for each test peptide.

Amino Acid Sequence↗

Quantification of leg muscle perfusion using thallium-201 single photon emission computed tomography.

The purpose of this study is to quantify leg muscle perfusion with 201Tl single photon emission computed tomography (SPECT). Six normal controls and 21 patients with peripheral arterial disease underwent this examination. Thallium-201 leg SPECT of both stress and redistribution was performed using a dual-headed digital gamma camera. Each slice of transverse images was normalized with pixels and whole-body counts. In normal controls, the activity of posterior tibial muscle components was significantly higher than that of anterior tibial muscle components (p less than 0.001). In 14 components, where patients had insignificant lesions, profile curves were normal in 10 (71%). In 62 components, where patients had arteriographically significant lesions, stress profile curves were abnormal in 57 (92%) compared with normal controls. Approximately, in half (28/62) components which had significant lesions, profile curves showed redistribution after 3 hr compared with normal redistribution curves. In three patients who underwent successful bypass graftings, the activity of each muscle component returned to a normal range.

Adult↗

Succinic acidemia: a new syndrome of organic acidemia associated with congenital lactic acidosis and decreased NADH-cytochrome c reductase activity.

Two siblings with succinic acidemia, a hitherto unreported organic acidemia, were investigated. Succinic acidemia, lactic acidosis and respiratory distress were observed in one of the siblings, who died 37 days after birth, and succinic acidemia was also detected in the next sibling at the fetal stage. NADH-cytochrome c reductase activity was significantly low in both cases and NADH-ferricyanide reductase activity was also low in the fetal case, suggesting a complex I deficiency of the electron transport system in the mitochondrial membrane.

Acidosis, Lactic↗