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T Obayashi

Publications and source records attributed to T Obayashi.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Clinical significance of the technetium-99m/thallium-201 overlap in acute myocardial infarction].

The region of overlap of thallium-201 (Tl) and technetium-99m pyrophosphate (Tc) was evaluated as a scintigraphic prognosticator of future necrosis. Serial time courses of myocardial perfusion according to Tl and left ventricular wall motion evaluated by two-dimensional echocardiography (2D echo) were used in 22 patients. In all, dual energy emission computed tomography (dual-SPECT) showed the Tl/Tc overlap on identical slices on the third post-infarction day. According to the results of dual-SPECT, the patients were categorized in three groups: nine with large Tl/Tc overlap (group A); five with small Tc accumulation and small Tl/Tc overlap (group B); and eight with large Tl defect and Tc accumulation, which are concordant with each other (group C). Tl-201 SPECT and 2D echo were attempted serially on the 1st and 2nd days, the 7th-10th days and the 28th-30th days. To estimate infarct size with Tl-201 SPECT, we measured pixel counts of eight short-axis images with the 40% cut-off level and computed "% defect". To evaluate the viability of the myocardium, "% Tl uptake" was computed from the ROIs both in the centers of the infarct areas and their border zones. 2D echoes of the left ventricular short axis at the chordae tendineae level were recorded to identify the time course of percent fractional area change (% FAC) of the ischemic left ventricular wall. The scintigraphic results were compared with the serial changes of regional ejection fraction in the areas of infarcts and ischemic lesions. The % defect remained unchanged in group C (29.2 +/- 11.5----25.7 +/- 8.3%); whereas those of groups A and B decreased significantly (21.2 +/- 11.3----9.9 +/- 6.3%, 13.8 +/- 2.6----5.4 +/- 2.9%, respectively). In groups A and B, % FAC improved significantly in the centers of the infarct areas and the border zones, but not in group C. Exercise-induced ischemia determined by redistribution of Tl at the chronic phase was observed more frequently in groups A and B than in group C. These findings indicated that more myocardium can be saved from necrosis in group A than in group C. In conclusion, it is suggested that there is considerable viable myocardium in patients with large Tl/Tc overlap on dual-SPECT.

Aged↗
PubMed1989

[Rapid diagnosis of gram-negative bacteriuria with endotoxin-specific chromogenic test].

Limulus amebocyte lysate test is a simple, yet sensitive laboratory method for detecting endotoxin. Although the specificity of the test was questioned, we recently solved this problem by removing a (1----3)-beta-D-glucan-sensitive factor G from the lysate (Endospecy, Seikagaku Kogyo Co., Ltd, Tokyo). In this study, we have established a method for the determination of endotoxin urine in using Endospecy. An aliquot of 0.2 ml of Endospecy dissolved in 4.4 ml of 0.1 mol/l Tris-HCl buffer (pH 8.0) was added to 5 microliter of urine sample. The mixture was incubated at 37 degrees C for 30 min. After diazo-coupling, absorbance was measured at 545 nm. The standard curve using Escherichia coli 0111: B4 endotoxin showed a good linearity. The addition-recovery test of various endotoxins showed nearly 100% recovery. Normal urine contained less than 60 pg/ml of endotoxin. Urine from patients with Gram-negative bacteriuria showed definitely high values, whereas urines infected either with Gram-positive bacteria or with fungi all showed nearly normal values. This method will be useful as a rapid and reliable test for the diagnosis of urinary tract infection with Gram-negative bacteria.

Endotoxins↗
PubMed1989

[Dobutamine stress thallium myocardial scintigraphy compared with two-dimensional echocardiography].

To assess the relationships among wall motion abnormality, myocardial ischemia and ST change in patients with myocardial infarction (MI), dobutamine stress thallium (Tl) myocardial scintigraphy, and two-dimensional echocardiography (2DE) and electrocardiography were simultaneously performed. Sixteen patients with anterior MI who underwent 2DE and ECG were studied at baseline and during dobutamine infusion with incremental doses of two to 40 micrograms/kg/min. The stress endpoints were chest pain, significant ST changes, tachycardia (greater than or equal to 110/min), and complicated arrhythmias. At the maximal tolerable dose of dobutamine, Tl scintigraphy was completed, and then repeated again four hours later. Left ventricular wall motion was evaluated using superimposed wall tracings of the configuration on 2DE, and was expressed as regional % area changes. Myocardial ischemia was quantified by SPECT and measured as regional % Tl uptake. Dobutamine stress testing was well tolerated by all patients, and no complications occurred. Hemodynamic changes included: heart rate increased from 61 +/- 9 to 113 +/- 11 beats/min, left ventricular end-diastolic volume (2DE) decreased from 93 +/- 27 to 59 +/- 33 ml, and mean blood pressure and ejection fraction were unchanged. In 11 of the 16 patients, redistributions on planar and SPECT images were observed. Although redistributions were observed in the areas adjacent to infarcts in patients with significant ST elevation in V3, additional wall motion abnormalities were not observed. The shape of the ST elevation had no relation to myocardial ischemia. In some cases, wall motion abnormality can be improved in spite of ischemia. Thus, this new combined method is useful for evaluating the relationship between ischemia and wall motion dynamics.

Adult↗
PubMed1989

[Changes of plasma amino acid on the course of septic multiple organ failure].

The changes of plasma amino acid (AA) pattern on the course of septic multiple organ failure (SMOF), and the effect of branched chain amino acid enriched solution (BCAA-S) on the AA pattern were evaluated in thirteen patients who died of SMOF in ICU. The course of ICU was divided into the following three stages. Stage I was a few days after the admission in ICU. Stage II was severe infected state. Stage III was terminal state. Following results were obtained: 1) Total AA value (TAA) of each stage was 2,693 n.mol/ml, 6,666 n.mol/ml and 19,480 n.mol/ml. 2) BCAA/aromatic AA (B/A) of each stage was 1.4, 1.03 and 1.05. Above values were lower than those of normal one (2.44). 3) Most kinds of AA in stage III were exhibited significantly higher than those of stage I as evaluated in absolute value. 4) In the BCAA-S administered group, B/A exhibited higher values than those of control, but, there was no sign of amelioration for SMOF condition in the former group. In severe infected or septic shock state, AA metabolism is deeply deteriorated. So, we can not decide whether BCAA-S given in this condition plays beneficial effect on the course of SMOF or not.

Adult↗
PubMed1986

Tortuous vertebral artery simulating extradural spinal tumour.

A rare case of cervical bone erosion resulting from pressure exerted by a congenital tortuous vertebral artery is presented with seven additional cases from the literature. The 3-4 level, especially on the left side, has been the most commonly affected site. The importance of the knowledge of this entity lies in the fact that it causes a surgically treatable radiculopathy, and also that this condition could easily be mistaken for a tumour, leading to accidental bleeding if carelessly approached.

Adult↗
PubMed1986

Endotoxin-inactivating activity in normal and pathological human blood samples.

The endotoxin-specific chromogenic test revealed that plasma endotoxin-inactivating activity was markedly diminished by endotoxemia, but not by fungemia or by dialysis with cellulose membranes, suggesting that fungal polysaccharides and other nonendotoxic, Limulus-reactive materials do not consume endotoxin-inactivating factors in the blood. There was a close negative correlation between plasma endotoxin concentration and endotoxin-inactivating activity. The specificity of the test was improved by fractionating amebocyte lysate and using only the factors that constitute the endotoxin-sensitive coagulation pathway of the horseshoe crab. This test was able to differentiate endotoxemia from fungemia and from contamination with other nonendotoxic, Limulus-reactive materials.

Endotoxins↗
PubMed1985

A new chromogenic endotoxin-specific assay using recombined limulus coagulation enzymes and its clinical applications.

A conventional limulus test is not specific to endotoxin because of the presence in amebocyte lysate of a (1----3)-beta-D-glucan-sensitive factor. By fractionating coagulation enzymes in the lysate and recombining only those factors involved in endotoxin-induced coagulation, we have developed a new test specific to endotoxin. The recombined enzymes reacted only with endotoxin, and not with fungal polysaccharides. Conventional amebocyte lysate, on the other hand, reacted with both of them. A good linearity was obtained with this method between endotoxin concentration and absorbance with a sensitivity of 1 pg/ml of Escherichia coli 0111:B4 endotoxin. The regression lines for different types of endotoxins were parallel to one another. For the correct diagnosis of endotoxemia, this new test has a definite advantage over the one using whole amebocyte lysate.

Arthropod Proteins↗
PubMed1984

Addition of perchloric acid to blood samples for colorimetric limulus test using chromogenic substrate: comparison with conventional procedures and clinical applications.

Preexposure of blood samples to perchloric acid permitted an accurate, quantitative measurement of endotoxin levels as low as 1 pg/ml using a colorimetric limulus test. Conventional chloroform and dilution-heating methods were unsatisfactory because of high residual nonspecific amidolytic activity and poor recovery. The normal peripheral plasma endotoxin level was less than 10 pg/ml when Escherichia coli 0111:B4 endotoxin was used as a reference. One nanogram in this assay was equivalent to 2.9 endotoxin units of USP reference standard endotoxin (E. coli 0113). High values were noted in portal venous blood and in cases of acute hepatitis, liver cirrhosis, strangulation ileus, pyothorax, lung abscess, diffuse panbronchiolitis, and pneumonia. Normal human plasma and serum exhibited a high capacity to inactivate added endotoxin. E. coli 0111:B4 and Salmonella minnesota 9700 were more susceptible to inactivation than Pseudomonas aeruginosa endotoxin. This inactivating activity was temperature dependent, was maximal between 37 degrees and 45 degrees C, and disappeared completely after heating plasma or serum to 56 degrees C for 30 minutes prior to the addition of endotoxin. The E. coli 0111:B4 endotoxin-inactivating activity of normal platelet-rich plasma, platelet-poor plasma, and serum, all at 37 degrees C, was 8.1 +/- 3.1, 11.7 +/- 4.5, and 15.2 +/- 4.9 micrograms/min/ml (mean +/- SD; n = 4), respectively. Endotoxin-inactivating activity was markedly decreased in plasma from patients with endotoxemia, but returned to normal with recovery from the underlying illness.

Colorimetry↗
PubMed1983

Human alpha 1-microglobulin levels in neurological disorders.

The concentration of alpha 1-microglobulin (alpha 1-m) in sera and cerebrospinal fluids (CSF) was measured in 121 patients with various neurological disorders. Using single radial immunodiffusion, its serum level was determined. No significant difference was found between the patients (29.1 +/- 4.3 mg/l; mean +/- 1 SD) and normal control group (23.7 +/- 4.6 mg/l). The level of CSF alpha 1-m was determined by the radioimmunoassay of solid antibody system. Its CSF level in the control group was 34.8 +/- 16.0 micrograms/l, while it was significantly increased in the patients with viral meningitis (p less than 0.01) and cerebral infarct (p less than 0.05). The level was also elevated in some cases of brain tumor, bacterial meningitis, cerebral hemorrhage, cervical spondylosis, and acute lymphocytic leukemia. There was a positive correlation between alpha 1-m and albumin levels in CSF. The analysis by CSF/serum albumin ratio and alpha 1-m ratio suggested that the increase of alpha 1-m in CSF could be explained mainly by an increase in permeability of the serum alpha 1-m through damaged blood brain barrier under these pathological conditions. Its local production within the central nervous system, however, could not be ruled out in these disorders.

Adolescent↗
PubMed1982

Perchloric acid treatment of human blood for quantitative endotoxin assay using synthetic chromogenic substrate for horseshoe crab clotting enzyme.

A new reliable human blood treatment was established for quantitative endotoxin assay using synthetic chromogenic substrate [Boc-Leu-Gly-Arg-rho-nitroanilide]. Addition of perchloric acid in a final concentration of 1.25% to platelet-rich plasma or serum in a 2:1 volume ratio completely eliminated nonspecific amidase activities as well as inhibitors. By this method, the recovery of added endotoxin was nearly 100%, and was almost independent of sample dilutions and anticoagulants.

Amidohydrolases↗