Biomedical subjects

T Yazawa

Publications and source records attributed to T Yazawa.

At least 73 records · Page 4Linked to original sources

PubMed1992

[Electrophysiologic effect of a new Ca(2+)-antagonist, TA-3090 on supraventricular tachycardia and conduction system].

We investigated the effect of a new Ca-antagonist, TA-3090 on supraventricular tachycardia (SVT) and conduction system, comparing it with the effect of Diltiazem Hydrochloride, in 11 patients who had paroxysmal SVT attacks. Seven of the 11 patients presented atrioventricular reentrant tachycardia (AVRT) via retrograde concealed conduction through an accessory pathway, and the others presented AV nodal reentrant tachycardia (AVNRT). After SVT was induced by means of programmed electrical stimulation at high right atrium, TA-3090 (0.1 mg/kg body weight) or Diltiazem (0.2 mg/kg) was administered intravenously for 3 minutes. TA-3090 terminated nine of 11 SVTs, while Diltiazem terminated four of 4 SVTs. On termination of SVT, both drugs interrupted A-H conduction during AVRT and the slow pathway during AVNRT. After TA injection, five of 11 SVTs could not be induced by programmed electrical stimulation, while two of 4 SVTs could not be induced after Diltiazem. In AVRT, three patients in which TA-3090 prevented SVT induction had a longer AV node effective refractory period than that of the others in which TA-3090 could not prevent SVT (330 +/- 46 vs 210 +/- 24 msec, p less than 0.01). However, SVT was induced more easily than before in three of the 11 patients treated with TA-3090 administration, and in one of the 4 patients treated with Diltiazem administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

Pulmonary blastoma with a topographic transition from blastic to more differentiated areas. An immunohistochemical assessment of its embryonic nature using stage-specific embryonic antigens.

In order to investigate the probable embryonic nature of pulmonary blastoma, immunohistochemical studies were performed using stage-specific embryonic antigens (Ley, Lex, sialyl Lex-i) in case of pulmonary blastoma with a very wide spectrum of morphological features. The tumour presented a topographic transition from primitive blastic and embryonic areas to more differentiated areas showing diverse differentiation. Blastic areas composed of extremely immature cells were found in most peripheral parts of the tumour. Inside the blastic areas there were "embryonic" areas which morphologically resembled human embryo lungs in the pseudoglandular and canalicular stages. Most central parts of the tumour showed more differentiated features including chondrosarcomatous, leiomyosarcomatous and rhabdomyosarcomatous elements and the common type of adenocarcinomatous element. Electron microscopic observation suggested the blastic and embryonic nature of these immature cell elements. Ley was expressed in the blastic and pseudoglandular areas. Lex was expressed in the canalicular areas. These antigens were not expressed in the more differentiated areas. The topographic gradient in the tumour of morphology and antigen expression from the peripheral blastic areas to the central more differentiated areas suggests that the primitive cells gradually differentiated into more mature cells of various directions as the tumour grew in size.

Antigens↗

PubMed1991

Expression of MHC class II antigens in human lung cancer cells.

Surgical specimens of lung cancers were examined immunopathologically for the expression of major histocompatibility complex class II (MHC-II) antigens in the tumor cells and their relationship to the lymphocytic infiltration. A lymphocytic infiltrate was frequently observed in the tumor tissue, though its intensity differed among the various histological types. MHC-II antigens were often demonstrated in tumors with a lymphocytic infiltrate. They were detected predominantly in the cytoplasm of tumor cells and to a lesser extent on the cell membranes. The emergence of the MHC-II-positive tumor cells was closely related to a local infiltration by lymphocytes including interferon-gamma (IFN-gamma)-producing T-cells. On the basis of the histological findings, an in vitro experiment was carried out. Four types of lung cancer cells were incubated with recombinant IFN-gamma in order to induce MHC-II antigens. MHC-II antigens (HLA-DR as well as HLA-DQ and HLA-DP antigens) were elicited in three cancer cell lines depending on the concentration of IFN-gamma. Immunoelectron microscopic study revealed that they were expressed on the surface of the cell membrane, though to a lesser extent than in the cytoplasm. It was considered that MHC-II antigens could be induced in some tumor cells in the immunological environment where IFN-gamma was secreted from T-cells and concentrated locally.

HLA-DQ Antigens↗

PubMed1991

Inhibitory effect of oral sorbent on accumulation of albumin-bound indoxyl sulfate in serum of experimental uremic rats.

Serum indoxyl sulfate, which is markedly accumulated in uremic patients, cannot be removed efficiently by hemodialysis due to its albumin binding. To determine if oral adsorbent (AST-120) can decrease its serum concentration in uremic state, oral adsorbent was administered to experimental nephrectomized uremic rats. Uremic rats fed with oral adsorbent showed a significantly lower serum concentration of indoxyl sulfate compared to control uremic rats, even when serum concentrations of urea nitrogen and creatinine were not significantly decreased in the uremic rats fed with oral adsorbent. Indoxyl sulfate was detected only at a lower concentration in bile as compared with the serum of uremic rats. These results suggest that oral adsorbent adsorbs indole, a precursor of indoxyl sulfate, in the intestine and prevents the accumulation of indoxyl sulfate in uremic rats.

Administration, Oral↗

PubMed1991

A case of lupus nephritis showing rectal erosion with cytomegalovirus infection.

A case of lupus nephritis showing rectal erosion with cytomegalovirus infection is described. The patient revealed nephrotic syndrome. She complained of skin ulcer with livedo reticularis on the right breast, purpura with thrombocytopenia, hepatic dysfunction, and bloody stool. Renal biopsy demonstrated diffuse proliferative lupus nephritis with prominent wire loops. Intestinal fiberscopy showed rectal erosion which was a cause of bloody stool, and rectal biopsy revealed cytomegalic inclusions characteristic of cytomegalovirus infection. Immunosuppression due to combined therapy with prednisolone and mizoribine could have led to reactivation of latent cytomegalovirus infection, resulting in the rectal erosion with bloody stool.

Adult↗

PubMed1991

[Treatment with percutaneous nephrolithotripsy and dissolution for bilateral renal cystine calculi in an infant].

A 20-month-old child was admitted to our hospital due to obstructive renal failure caused by cystine calculi. After recovering from the renal failure by bilateral percutaneous nephrostomy, pelvic irrigation with N-acetylcysteine was performed using a 12Fr. flexible double lumen catheter. In 2 weeks the calculus was reduced by 39% in size, then residual calculi were successfully removed by percutaneous nephrolithotripsy using 11.5Fr. rigid ureteroscope and postoperative irrigation with N-acetylcysteine.

Acetylcysteine↗

PubMed1990

Enzyme immunoassay for urinary albumin at low concentration in diabetes mellitus.

Microalbuminuria, an increased excretion of urinary albumin undetectable by Albustix test strips, appears to predict the late development of diabetic nephropathy at a stage that albuminuria might be reduced by good metabolic control Once albuminuria is detected by Albustix, it indicates the likelihood of diabetic nephropathy. Microalbuminuria is also related to an increased prevalence of proliferative retinopathy, blindness, and peripheral neuropathy. It is therefore important to detect microalbuminuria by a sensitive, rapid and simple method. Microalbuminuria can be measured by radial immunodiffusion, immunoelectrophoresis, radioimmunoassay, enzyme immunoassay, latex-bead immunoagglutination, turbidimetric immunoassay and dye-binding. The disadvantages of radioimmunoassays are: short shelf life, isotope-related health and safety hazards, and the expense of equipment used to measure gamma-emitting isotopes. Our aim in this study was to develop a simple, rapid and sensitive one-step sandwich enzyme immunoassay using anti-human albumin monoclonal antibodies for screening microalbuminuria.

Adult↗

PubMed1990

Efficient removal of albumin-bound furancarboxylic acid, an inhibitor of erythropoiesis, by continuous ambulatory peritoneal dialysis.

3-Carboxy-4-methyl-5-propyl-2-furanpropionic acid, which cannot be removed by conventional hemodialysis due to its strong albumin binding, was found to be efficiently removed by continuous ambulatory peritoneal dialysis (CAPD), resulting in a lower serum level in uremic patients on CAPD than in those on hemodialysis. 3-Carboxy-4-methyl-5-propyl-2-furanpropionic acid was demonstrated in vitro to inhibit erythroid colony formation. The anemia in patients on CAPD was significantly less severe than in those on hemodialysis. These results suggest that the efficient removal by CAPD of 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid, an inhibitor of erythropoiesis, is related to an improvement of anemia in patients on CAPD.

Adult↗

PubMed1990

[Effect of oral sorbent, AST-120, on serum concentration of indoxyl sulfate in uremic rats].

Indoxyl sulfate is a metabolite of tryptophan. Indole is synthesized in intestine from tryptophan by intestinal bacteria. The absorbed indole is converted to indoxyl sulfate through indoxyl in liver. Serum concentration of indoxyl sulfate is markedly increased as an inhibitor of drug-binding in uremic patients as compared with healthy subjects. Since indoxyl sulfate is bound to serum albumin, it cannot be removed efficiently by hemodialysis, and it tends to accumulate in uremic serum. To determine if oral sorbent, AST-120, could adsorb indole in intestine and then decrease serum concentration of indoxyl sulfate, it was administered to nephrectomized uremic rats. Serum concentration of indoxyl sulfate was markedly decreased in uremic rats fed with oral sorbent as compared with control uremic rats. However, serum concentrations of creatinine and urea nitrogen were not significantly decreased in the uremic rats fed with oral sorbent as compared with the control uremic rats. Serum concentration of tryptophan was not decreased but rather increased in the uremic rats fed with oral sorbent as compared with the control uremic rats. Concentration of indoxyl sulfate in bile of a uremic rat was much lower than that in the uremic serum, suggesting that the adsorption of indoxyl sulfate in intestine is not a major mechanism of decreasing the serum concentration of indoxyl sulfate. These results demonstrate that oral sorbent, AST-120, can decrease serum concentration of indoxyl sulfate in uremia due to adsorption of indole in intestine.

Administration, Oral↗

PubMed1990

[An autopsy case of HTLV-I associated myelopathy (HAM) with adult T-cell leukemia (ATL)].

An autopsy case of HTLV-I associated myelopathy (HAM) combined with adult T-cell leukemia (ATL) was reported. Although HAM and ATL are reported to be caused by an identical virus, a combination of these two conditions is extremely rare. This is the first report of an autopsy of the case. A 42-year-old female born in Kumamoto noticed gait disturbance at age 20. Dysesthesia in her lower limbs and bladder bowel disturbance (BBD) gradually appeared at age 29 and at age 39, respectively, and slowly progressed. Neurological examination revealed spastic paraparesis, sensory disturbance in her lower limbs in all modalities and BBD. Furthermore, titers of the anti HTLV-I antibody were increased both in serum and CSF. She was diagnosed as HAM at this stage. She responded to the oral administration of prednisolone. Ten months after the initiation of prednisolone therapy, a tumor shadow appeared in the right lung and characteristic ATL cells were found in the pleural effusion. She died with respiratory failure. ATL cells were not found either in the peripheral blood or CSF throughout the course of her illness. Autopsy revealed solid tumors in both lungs, liver, kidneys, spleen, thyroid gland and para-aortic lymphnodes, composed of ATL cells with extensive necrosis. The spinal cord showed a marked loss of myelin and axons, and perivascular fibrosis in the lateral and anterior columns. These changes were most severe at the 6th and 7th thoracic segments. No ATL cell was found in the spinal cord. Concerning the sensory system, the posterior root, ganglion and posterior column were preserved, whereas the axonal degeneration was found in the biopsied specimen of the sural nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

PubMed1988

Clinical, electrophysiological, and histopathological observations in supraventricular tachycardia.

Fifty patients with supraventricular tachycardia (SVT) underwent clinical electrophysiological studies (EPS), endomyocardial biopsies and cardiac catheterizations. EPS revealed AV nodal reentrant tachycardia (AVNRT) in seven patients, AV reentrant tachycardia utilizing concealed AV bypass tracts (AVR-CBT) in nine patients, AV reentrant tachycardia utilizing AV bypass tracts with ventricular preexcitation (manifest WPW) in 13 patients, sinus nodal or intra-atrial reentrant tachycardia (SNRT or IART) in three patients, atrial flutter (AF) in nine patients, automatic atrial tachycardia (AAT) in five patients, and multifocal atrial tachycardia (MAT) in four patients. According to the clinical observations, three patients with AVNRT (43%), six with AVR-CBT (67%), six with manifest WPW (46%), two with SNRT or IART (67%), eight with AF (89%), two with AAT (40%), and two with MAT (50%) showed other accompanying clinical abnormalities. In all patients who were studied histologically, changes in the myocardium were seen; myocarditic changes, postmyocarditic changes and nonspecific abnormalities were present in six (12%), 15 (30%), and nine (18%) respectively. Myocardial changes were observed in four out of seven cases with AVNRT (57%), in six out of nine with AVR-CBT (67%), in five out of 13 with manifest WPW (38%), in two out of three with SNRT or IART (67%), in six out of nine with AF (67%), in all five cases of AAT (100%), and in two out of four with MAT (50%). Nineteen out of 32 without clinical abnormalities except for arrhythmias (59%) had myocardial changes (six had myocarditic changes, ten had postmyocarditic changes, and three had nonspecific abnormalities). On the other hand, nine out of 21 with myocarditic or postmyocarditic changes were accompanied with various arrhythmias other than SVT (two had SSS, five had AV block or rBBB, and two had VT). Elevated LVEDP was present in 36% of the group with normal myocardium and in 53% of the group with myocardial changes. However, the low EF was shown in no patients with normal myocardium but in 21% of the group with myocardial changes. The low CI was also shown in only 9% of the group with normal myocardium but in 28% of the group with myocardial changes. These results suggest that patients with SVT may exhibit several histopathological changes in the myocardium, even in the absence of any clinical organic heart disease.

Adult↗

PubMed1988

The occurrence of acute lymphoblastic leukemia shortly after the cessation of human growth hormone therapy.

We encountered a case of a 21-year-old man who had developed acute lymphoblastic leukemia (ALL) shortly after the cessation of approximately six years' human growth hormone treatment for pituitary dwarfism. The patient had also been treated with thyroid preparations and methylandrostanolone, a kind of anabolic steroid. Factors relating to the onset of ALL in this case are discussed.

Child↗

PubMed1988