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Biomedical subjects

S Akamatsu

Publications and source records attributed to S Akamatsu.

At least 73 records · Page 4Linked to original sources
PubMed1993

Development and characterization of a novel anti-fucosylated antigen monoclonal antibody YB-2 and its usefulness in the immunohistochemical diagnosis of colorectal cancer.

A novel monoclonal antibody, YB-2 was obtained after immunization of mice with fucosylated antigens isolated from human saliva. The antibody was demonstrated to react with Y (Fuc alpha 1-->2Gal-beta 1-->4[Fuc alpha 1-->3]GlcNAc beta),Leb (Fuc alpha 1-->2Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta) and H type 2 (Fuc alpha 1-->2Gal-beta 1-->4GlcNAc beta) antigens, but not with H type 1 (Fuc alpha 1-->2Gal beta 1-->3GlcNAc beta), Lea (Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta), X (Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta) or with non-fucosylated antigens. Inhibition assays of YB-2 antibody with such reactive antigens showed that YB-2 antibody preferentially reacted with Y antigen. Formalin-fixed and paraffin-embedded sections prepared from normal and malignant colorectal tissues were examined immunohistochemically with YB-2. The positive rates of staining with YB-2 antibody were 88.6% in malignant and 12.0% in normal tissues. The expression of fucosylated antigens detected by YB-2 antibody seemed to be correlated with survival among patients with primary colorectal cancer. Therefore, YB-2 antibody could be useful as an immunochemical tool for diagnosis and evaluation of the prognosis of colorectal cancer.

Antibodies, Monoclonal↗
PubMed1993

Mitral prosthetic dehiscence with laminar regurgitant flow signals assessed by transesophageal echocardiography.

A patient with a Björk-Shiley mitral prosthesis developed progressive heart failure without heart murmur and hemolysis. The prosthetic dehiscence was not diagnosed using transthoracic echocardiography, but transesophageal echocardiography. The regurgitant signals revealed laminar flow pattern with large regurgitant orifice. In patients with mitral prosthetic dehiscence with laminar flow pattern, transesophageal echocardiography can provide reliable diagnostic information.

Adult↗
PubMed1993

[Detection of carbohydrate antigens of malignant cells in sputum with panel of monoclonal antibodies].

Serum tumor markers are useful for post-operative follow up, however, they are not necessarily useful for early stage diagnosis. Because the lesion is so small that it is unable to detect a tiny amount of their molecules in serum. If we could detect those antigens directly in cells from cytological specimens, it would provide a new diagnostic method for early stage cancers. The expression of carbohydrate antigens were examined with panel of specific anti-carbohydrate monoclonal antibodies (MAbs) on cytological specimens of sputum. In total, 146 sputa were collected in Sacomano's solution; 69 malignant cases (35 squamous cell carcinomas, 13 adenocarcinomas and 21 other primary lung cancers), 19 benign cases (pneumonia and bronchitis) and 58 borderline-malignancy cases which were defined by the standard of Japan Society of Lung Cancer. After removing mucus, the cells were stained with Vector's ABC method. Evaluation was performed by counting positively-stained cells among benign or atypical cells. As we examined previously in lung cancer tissue sections, there was statistical significance of frequency of positive stain between malignant and benign cases especially in MAbs AH6, THK2, SH1 and SNH3. Borderline malignancy gave intermediate value which means certain number of cells with cancerous biochemical character are mixed in the borderline specimens. In most cases, cell membrane was positively stained and sometimes, cytoplasm. Although the high sensitivity was observed in AH6 and SNH3, their specificity was lower than that of SH1, and visa versa. Those results indicate that the combination of anti-carbohydrate MAbs is useful for cytological diagnosis of lung cancer.

Antibodies, Monoclonal↗
PubMed1992

Age-related increase in systolic fraction of pulmonary vein flow velocity-time integral from transesophageal Doppler echocardiography in subjects without cardiac disease.

The pulmonary vein flow velocity-time profile would be equivalent to the pulmonary vein flow volume-time profile, provided that the cross-sectional area of the pulmonary vein remains unchanged during 1 cardiac cycle. The systolic fraction of the pulmonary vein flow velocity-time integral, a ratio of velocity-time integral of the S wave to the sum of velocity-time integrals of the S and D waves, represents the ratio of left atrial storage volume to left ventricular stroke volume. This systolic fraction may help early filling of the left ventricle through an appropriate storage of blood and generation of driving pressure in the left atrium. Because early filling of the left ventricle is progressively impaired with age, it was hypothesized that this systolic fraction is increased with age. Forty-four noncardiac surgical patients (age range 17 to 70 years) who underwent transesophageal Doppler echocardiography under general anesthesia were studied, and left upper pulmonary vein flow and mitral inflow velocities were recorded. The ratio of peak velocity of the E wave to that of the A wave of mitral inflow velocity-time profile (y) decreased with age (y = -0.0245 x age + 2.41; r = -0.672, p < 0.01). Systolic fraction (y) increased with age (y = 0.00373 x age + 0.514; r = 0.656, p < 0.01). The age-related increase in the systolic fraction of pulmonary vein flow velocity-time integral may account for the compensation for impaired early filling of the left ventricle in elderly patients.

Adolescent↗
PubMed1992

Biological activity of chemically synthesized core sugar linked lipid A analog, heptose-(alpha 1----5)-2-keto-3-deoxyoctonic acid-(alpha 2----6)-2,3-diacyloxyacylglucosamine-4-phosphate.

The mitogenicity, lethal toxicity and antitumor activity against Meth A fibrosarcoma and the induction of tumor necrosis factor (TNF) of chemically synthesized compounds designated as A-103, 2,3-diacyloxyacylglucosamine-4-phosphate (GlcN-4-P), and A-503), heptose-(alpha 1----5)-2-keto-3-deoxyoctonic acid (KDO)-linked GlcN-4-P (A-103), were determined. Compound A-103 induced significant incorporation of [3H]thymidine of C57BL/6 mice at 25-100 micrograms/ml, and A-503 showed the highest incorporation of [3H]thymidine at 100 micrograms/ml. The mitogenicity of A-503 exhibited a lower activity than of A-103. Compound A-503 showed no lethality at high doses of 25 and 50 micrograms/mouse in C57BL/6 mice loaded with D-galactosamine, whereas A-103 caused the death of one of three mice at a dose of 50 micrograms/mouse. Although, the two compounds with or without muramyl dipeptide showed weak antitumor activity against Meth A fibrosarcoma in BALB/c mice, but there were no remarkable differences between the compounds on antitumor activity. Peritoneal macrophages, stimulated with A-103 or A-503 caused no production of TNF which induces L929 cell lysis in vitro. These findings indicate that the addition of heptose and KDO to GlcN-4-P seems not to affect mitogenic activity, lethal toxicity, antitumor activity and TNF-production of the GlcN-4-P compound (A-103).

Animals↗
PubMed1991

Immunoreactive transforming growth factor alpha is commonly present in colorectal neoplasia.

Surgical specimens from 19 patients with invasive colorectal cancers and 12 specimens of normal mucosa from the same patients were examined immunohistochemically for the production of the immunoreactive (IR-) transforming growth factor (TGF)-alpha and IR-epidermal growth factor (EGF) with an anti-TGF-alpha monoclonal antibody (MAb) OAL-MTG01 and anti-EGF MAb KEM-10. Immunoreactive TGF-alpha was detected in 16 (84.2%) of 19 colorectal cancers. In contrast, there was no IR-TGF-alpha in the gland cells of normal mucosa. Immunoreactive EGF was detected in 7 (36.8%) of 19 colorectal cancers and 1 (8.3%) of 12 cases of normal mucosa. The production of both IR-TGF-alpha and IR-EGF in colorectal cancer did not differ by histologic type and Dukes' stage. Immunoreactive TGF-alpha was detected at significantly higher incidence than IR-EGF in colorectal cancer. These results indicate that IR-TGF-alpha should prove valuable as a possible tumor marker in colorectal cancers, and it may be very useful in understanding the biology of colorectal cancer.

Antibodies↗
PubMed1991

[Evaluation of intraoperative transesophageal echocardiography].

With the development of medical ultrasonics, anesthesiologists have recognized the usefulness of transesophageal echocardiography as an intraoperative monitoring. Intraoperative transesophageal echocardiography is now used to monitor left ventricular function and to confirm the result of surgical correction immediately after cardiac operation. In this study, we evaluated the detectability of air embolism and the effect of hemodynamic changes on physiological mitral regurgitant flow by transesophageal Doppler echocardiography (TEDE). TEDE was more sensitive than precordial Doppler ultrasound in detecting intracardiac air. TEDE could detect air inflow to the right atrium earlier than alterations in pulmonary hemodynamics. The monitoring of intracardiac air by TEDE minimized the complication by air embolism. Regarding physiological mitral regurgitation, the degree of regurgitation increased with the elevation of BP in 70% of patients. An increase in afterload seemed to cause accidental volume loading on the left heart resulting in physiological mitral regurgitation. Intraoperative monitoring of regurgitant flow by TEDE was useful for the anesthesiologist as a guide of hemodynamic management. Transesophageal echocardiography is a useful intraoperative monitoring method regardless of its several disadvantages. With further improvement of mechanical device, transesophageal echocardiography will be more often and safely performed in operating room.

Echocardiography, Doppler↗
PubMed1990

[Evaluation of physiological mitral regurgitant flow using transesophageal Doppler echocardiography].

Transesophageal Doppler echocardiography (TEDE) was performed to determine the incidence of physiological mitral regurgitation (MR) and the characteristics of regurgitant blood flow in presumably normal subjects. TEDE included color flow mapping, pulsed Doppler echocardiography and M-mode color flow mapping. Sixty-six surgical patients who had no histories or physical evidence of cardiac abnormalities were studied using TEDE under general anesthesia. MR flow was detected in 94% (62/66) of the patients by transesophageal color flow mapping. Transesophageal color flow mapping clearly differentiated physiological MR flow and signals generated from mitral valve closure. In 40% (25/62) of the patients whose MR flow was detected, transesophageal pulsed Doppler echocardiography (TEPD) revealed regurgitant signals lasting less than half of systole. Only 31% (19/62) had peak MR flow velocities greater than 1 m/sec. TEPD could not detect high velocities reflecting the pressure gradients across the mitral valve. Since the regurgitant volume was very small, TEPD may have been incapable of detecting high velocity components of the MR flow. In conclusion, our data suggested that nearly all normal subjects may have mild mitral regurgitation.

Adolescent↗
PubMed1990

Variations in intrathyroidal lithium content and their effect on the iodide uptake in mouse thyroid.

Lithium (Li) is accumulated in the thyroid but the mechanism of Li accumulation is not known. In the present study, the causes of variation in Li concentration in the thyroid and the relation between cellular Li and iodide were examined. This was done by using mice treated with Li (0.01% as Li2CO3) for 4 weeks, co-administered with propylthiouracil (PTU, 0.5 mg/ml daily p.o.) or thyroxine (T4, 0.5 micrograms per day i.p.) for last 10 days. The total content of Li in a whole thyroid (ng/thyroid) was not changed through treatment with PTU or T4. But the Li concentration in terms of mg/kg of the gland was reduced with PTU and was unchanged or slightly increased with T4, due to the change in the mass of thyroid. Furthermore, short-term (3 h) Li uptake in the thyroid was not affected by pre-treatment with PTU or T4. These results indicate that the variation in thyroidal Li concentration was not due to a direct effect of PTU or T4 on Li transport, but to a thyroidal condition caused by the secondary influence of drugs. A measurement of the thyroid: serum iodide concentration ratio (T/S) of 125I showed that the iodide uptake was reduced when intracellular Li concentration was high, and that PTU alone elevated the T/S, but Li + PTU brought it back to a normal level; whereas, T4 alone diminished the T/S, Li + T4 made it rise significantly more than did T4 alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Effect of lithium carbonate administration singly or in combination with some psychotropic drugs on the radioiodide uptake by mouse thyroid.

The present study dealt with two objects; the first object was to examine whether or not lithium uptake in thyroid is modified by the thyroid state and how the intrathyroidal Li affects iodide uptake by the thyroid. Male and female mice were given lithium carbonate (Li) with propylthiouracil (PTU) or thyroxine (T4). Li was measured by a flameless atomic absorption spectrometry. The total Li content in thyroid was unaffected with PTU or T4, however, Li concentration per unit mass was reduced by PTU but unaffected by T4. The thyroid: serum ratio (T/S) of 125I resulted that the T/S became higher when Li concentration per unit mass was lower and vice versa, suggesting that Li uptake is controlled by thyroid states and Li in the gland interferes with the iodide uptake. Serum triiodothyronine (T3) and T4 by radioimmunoassay showed that PTU alone and in combination with Li lowered serum T4, while a high level of T4 by its supplement was suppressed by co-administration of Li. T3 level was lowered by Li alone, but not severely affected by other drugs. The results suggest that Li enhances T4 clearance without T4-T3 conversion. The second object was to examine the effect of combined psychotropic drugs on thyroid function. Carbamazepine (CBZ), haloperidol (HLP) and imipramine (IPA) were given singly or in combination with Li to examine their effects on the T/S of 125I. Only CBZ reduced the T/S but CBZ plus Li had no summative effect. Neither HLP nor IPA affected the T/S, singly or in combination with Li, suggesting that HLP or IPA does not interfere with an iodide pumping machinery. No distinct sex difference was observed in drug effects.

Animals↗
PubMed1989

[Succinylcholine neuromuscular blockade in a case of pseudocholinesterase variant].

Since there is little or no pseudocholinesterase at the motor end plate, the neuromuscular blockade by succinylcholine is terminated by its diffusion away from the end-plate into extracellular fluid. Pseudocholinesterase (ChE), therefore, influences the duration of action of succinylcholine (SCC) by controlling the rate of hydrolysis before it reaches the end-plate. SCC neuromuscular blockade can be prolonged in the presence of an atypical form of ChE. A 37 year old male with the deficiency of ChE activity underwent pancreatico-duodenectomy under neuroleptanesthesia. The mode, duration and treatments of neuromuscular blockade following succinylcholine (SCC) were studied using train-of-four (TOF). SCC was administered 6 times (total 170 mg) during the operation. Prolonged apnea was noted after the first intravenous injection of SCC (60 mg, 1 mg.kg-1). It was found that spontaneous resolution of the neuromuscular block had four phases and there was a pronounced fade of the TOF response. After the second injection of SCC (30 mg), a remarkable fade of the TOF was detected and the character of the block was considered to be a desensitizing block (phase II block). The block was treated by intravenous infusion of fresh frozen plasma (FFP) (400 ml) which contained ChE, at the rate of 231 +/- 56 IU/l/37 degrees C begun shortly after the fifth injection of SCC (20mg). The duration of the block was remarkably shortened but the recovery curves were almost unchanged, indicating the diffusion of SCC away from the end-plate and/or that receptor-channel is presumably slow. The neuromuscular blockade was fully reversed by additional injection of FFP (400 ml) before extubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗