Search PubMed⌕ Search

Biomedical subjects

T Fujiwara

Publications and source records attributed to T Fujiwara.

At least 829 records · Page 46Linked to original sources
PubMed1992

Vascular alpha-1 antagonistic and agonistic effects of beta adrenoceptor agonists in rabbit common carotid arteries.

The stainless-steel cannula-inserting method was used to observe vascular effects of mixed and selective beta adrenoceptor agonists, isoproterenol, procaterol and denopamine, on isolated, perfused rabbit common carotid arteries. In phenylephrine-preconstricted preparations, the three beta agonists induced a dose-dependent vasodilation which was not suppressed by treatment with beta antagonists, atenolol, a selective beta-1 antagonist and ICI 118551, a selective beta-2 antagonist. On the other hand, in prostaglandin F2 alpha-preconstricted preparations, these agonists produced no vasodilation and revealed weak vasoconstrictions which were readily suppressed by bunazosin, a selective alpha-1 antagonist. Moreover, these agonists caused a shift of the dose-response curve for phenylephrine to the right in a parallel fashion in non-preconstricted preparations. The relative pA2 values for isoproterenol, procaterol and denopamine calculated from the displacement curve were 7.47, 7.59 and 8.17, respectively. Thus, it is concluded that 1) there are little functional beta adrenoceptors in the rabbit common carotid arteries, 2) beta adrenoceptor agonists have both antagonistic and agonistic properties for alpha-1 adrenoceptor activation, 3) denopamine possesses a higher potency as an alpha-1 antagonist and 4) beta agonists generally act as vasodilators in rabbit cerebral circulation.

Adrenergic beta-Agonists↗
PubMed1992

[Choice of conduit in coronary bypass surgery].

Since 1987, arterial conduits have been used in 78 of 130 cases receiving coronary bypass surgery, including 25 treated by arterial conduits alone. The use of arterial conduits was mainly indicated to the anterior descending coronary artery (LAD), but the saphenous vein had to be used in 39 percent, 47 of 120 cases receiving bypass grafting to the LAD for various reasons including a combination of multiple obstructive arteriosclerosis, multiple bypass graftings in the aged, unstable angina, emergency operation and no suitable artery for a conduit as indicated by preoperative angiography. Hereafter, arterial conduits for coronary bypass grafting to LAD should be used in many more cases to the best possible advantage.

Adult↗
PubMed1992

Evaluation of four semi-synthetic Mycobacterium leprae antigens with sera from healthy populations in endemic and non-endemic areas.

In order to determine the frequency of occurrence of antibodies to semisynthetic antigens of Mycobacterium leprae in clinically healthy nonpatient populations and to establish a 'baseline' for comparison with antibody frequencies in both patients with a history of leprosy and their contacts, ELISAs were conducted using representative sera from two areas: a leprosy endemic area, Cebu City, Philippines and a nonendemic area for leprosy Chicago, Illinois, USA. These sera were tested, by an indirect IgM ELISA, for the presence of antibodies reacting with four semisynthetic antigens based on the phenolic glycolipid I antigen of M. leprae: ND-O-BSA (natural disaccharide with octyl linkage to bovine serum albumin), NT-O-BSA (natural trisaccharide with octyl linkage to BSA), ND-P-BSA (natural disaccharide with phenolic ring linkage to BSA) and NT-P-BSA (natural trisaccharide with phenolic ring linkage to BSA). Using an OD reading > or = 0.16 as positive, the antigen with the lowest background seroreactivity was ND-O-BSA, which reacted with 5/398 (1.3%) sera from Cebu, and 3/426 (0.7%) sera from Chicago. A total of 10 (2.5%) of 398 sera from the endemic area reacted with at least one antigen and 5 (1.3%) sera reacted with all four semisynthetic antigens. Of the 426 sera from Chicago, 12 (2.8%) were reactive with at least one antigen and 3 (0.7%) were reactive with all four semisynthetic antigens. Mean ELISA values for the 22 positive sera for each antigen ranged from 0.17 to 0.3 OD units, while the mean values for all sera in each area ranged from 0.01 to 0.04 OD units for all four antigens. Reactivity of 14 of the positive sera to some antigens, but not all four semisynthetic antigens, indicated that the carrier and linker arms might be associated with this background reactivity. Investigation of alternative linker arms and carriers is warranted. We conclude that nonspecific background reactivity to the semisynthetic antigens representing the PG-I molecule of M. leprae is 0.7-1.3%, based on a > or = 0.16 OD cutoff value. From these data it was concluded that reactivity in individuals free of leprosy was low enough to warrant use of these antigens in a diagnostic setting, such as screening household contacts and highly endemic populations. When incidence and prevalence of leprosy are low, testing with these antigens would not be cost effective, unless applied to high risk individuals.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

[Quantitative analysis of glutathione and glutathione S-transferase in human brain tumors, C6 rat glioma cells and drug resistant C6 cells].

Glutathione (GSH) and Glutathione S-transferase (GST) plays an important role in the protection of cells against damage from free radicals and also influences cytotoxicity to some kinds of chemotherapeutic agents. GST comprises a group of abundant and widely distributed catalytic and binding proteins that facilitate the conjugation of GSH with the electrophilic center of a large spectrum of hydrophilic molecules. Multiple GST isozymes in mammalian tissues arise from dimeric combination of a number of distinct subunits grouped into three major classes: alpha (alpha), mu (mu), and pi (p). We report the total GST, GST-p activity and GSH content of human brain tumors, C6 rat glioma cells and drug resistant C6 cells. The values of total GST activity in 42 normal brain and brain tumors were quantitatively analyzed. Total GST activity was 92.6 +/- 25.1 units (mean +/- standard deviation) in 8 samples of normal brain tissues, 126 +/- 58.8 units in five grade II or III astrocytomas (154 +/- 63.3 units in grade II astrocytomas, 84.4 +/- 2.7 units in 2 grade III astrocytoma), 66.2 +/- 29.3 in 5 glioblastoma cases, 94.7 +/- 47.7 units in 3 metastatic tumors, 302 +/- 114 unit in 8 meningiomas and 213 +/- 90.4 units in 3 neurinomas. Differences of GST activity between glioblastomas and meningiomas, grade II or III astrocytomas and meningioma, in normal brain tissues and meningioma were statistically significant (p < 0.01). The difference between normal brain tissues and benign tumors (meningiomas and neurinomas), gliomas and benign tumors were also statistically significant (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Dilated cardiomyopathy following alpha interferon therapy of renal tumor with pulmonary metastases: a case report].

We report a case of renal cell carcinoma with pulmonary metastases treated with recombinant alpha interferon and subsequently presenting as congestive heart failure due to a dilated cardiomyopathy. A 66-year-old man presented himself to the department of internal medicine at our hospital with a complaint of persistent cough with sputum on August 27, 1988. Ultrasonogram, computed tomography and angiography showed a right renal cell carcinoma and chest x-ray films disclosed bilateral multiple nodular shadows, probably representing metastases of the renal tumor. After being transferred to our department, the patient underwent the ligation of the right renal artery and vein and the postoperative treatment with recombinant alpha interferon, achieving a complete response for pulmonary metastases and a partial response for the primary region. On February 14, 1990 the patient was admitted to our hospital with a complaint of dyspnea to be diagnosed as congestive heart failure due to dilated cardiomyopathy. The interferon therapy was suspected to have caused the heart disease, and four months after discontinuation of interferon therapy the heart failure symptoms had improved, but hypokinesis of the cardiac wall still persisted. To our knowledge, this may be the first case of alpha interferon-related cardiomyopathy in Japan.

Aged↗
PubMed1992

[Coronary bypass surgery using arterial conduit and its pitfall].

Three patients with spasm of internal mammary arteries and gastroepiploic artery immediately after coronary bypass surgery were reported. On completion of the revascularization, all patients could not be weaned from cardiopulmonary bypass. The flow velocity waveforms of the arterial grafts measured by pulsed Doppler velocimeter showed only small systolic component without diastolic flow and the palpation revealed profound spasm partially in the arterial conduits. Although all patients could be weaned from cardiopulmonary bypass only after insertion of a saphenous vein graft, two of them died on the next day. In all patients, free flow measured prior bypass was considered to be sufficient and a technically satisfactory anastomosis was felt to be performed. If a profound hemodynamic instability as a result of intractable spasm of arterial conduit occurred after completion of coronary bypass surgery, an additional saphenous vein graft should be placed before discontinuation of cardiopulmonary bypass.

Aged↗
PubMed1992

[Efficacy of percutaneous transluminal coronary angioplasty for cardiac event after coronary bypass surgery].

In 31 cases with previous coronary artery bypass graft (CABG) surgery, 46 percutaneous transluminal coronary angioplasty (PTCA) attempts were performed, including 21 angioplasty in vein grafts (success rate 95.7%). Overall success rate was 87.0%. No major complication occurred, but one reperfusion arrhythmia (ventricular tachycardia) in a case of AMI. PTCA was so effective and useful for cardiac events in cases with previous CABG surgery with low risk and minor complication.

Adult↗
PubMed1992

[The influence of increase in heart rate on coronary flow dynamics in the patients with aortic stenosis].

To clarify the causative factors responsible for the development of effort angina in aortic stenosis, the influence of an increase in heart rate by atrial pacing and isoproterenol infusion on the phasic left coronary flow velocity waveforms were studied using a pulsed Doppler velocimeter during cardiac surgery. Coronary flow velocity waveforms in aortic stenosis was characterized by a slowly increased diastolic inflow and an elongation of the time from the onset of diastole to the diastolic peak velocity. An increase in heart rate by pacing brought about a marked decrease in diastolic coronary flow since the slowly increasing diastolic flow was cut with the onset of following systole. On the contrary, after an increase in heart rate by infusion of isoproterenol, diastolic increasing rate in the coronary flow waveform accelerated and diastolic peak velocity markedly increased. As the results, isoproterenol produced a significant increase in diastolic coronary inflow.

Aged↗
PubMed1992

[Four cases of aortic valve replacement in aortitis syndrome].

Four surgically treated cases of aortic valve regurgitation associated with the aortitis syndrome were reported. All patients were female and ranged in age from 38 to 51 years. In two cases, obstructive lesions of the aortic arch branch were seen in aortograms. Three patients had no inflammatory findings at the operation and one was operated on after improvement of inflammatory findings by steroid therapy. Aortic regurgitation was caused by annuloaortic ectasia, and aortic valve replacement was performed by the everting mattress suture method in all cases. One patient with stenosis of the left carotid artery, occlusion of the left subclavian artery, and hypertension died of extended cerebral damage due to suspected low flow cerebral perfusion during cardiopulmonary bypass. The other three patients are doing well 4 months to 11 years after surgery without paravalvular leakage. In cardiac surgery for the aortitis syndrome with an obstructive lesion of the aortic arch branch, deep hypothermic and high flow cardiopulmonary perfusion is required to prevent ischemic brain complications during surgery.

Adult↗
PubMed1992

[A juvenile case of mesenchymal chondrosarcoma originating from soft tissue in the orbit].

Mesenchymal chondrosarcoma is a very rare occurrence in the orbit. A 10-year-old girl presented with right exophthalmos. Computed tomography revealed a round tumor inside the muscular cone of the right orbit. There was a sign of slight calcification inside the tumor. The tumor was surgically removed by the Krönlein-Berke procedure. Histopathological examination showed undifferentiated mesenchymal cells and cartilage tissue. A recurrent tumor was found in the same location 34 months after the surgery, which was removed by frontal approach saving the globe with normal function. Histopathology of the recurrent tumor revealed a slight difference from the primary tumor, showing hemangiopericytoma pattern without cartilage components. Immunohistochemical studies of the primary and recurrent tumors showed their cells to be positive for antifactor VIII and S-100, and negative for myoglobin and monoclonal antibody to muscle actin. Electron microscopically these undifferentiated cells had large nucleus and very scanty cytoplasm, mostly containing glycogen granules. This is probably the first description of a juvenile case of mesenchymal chondrosarcoma originating from soft tissue in the orbit.

Child↗
PubMed1991

Molecular cloning of the cytochrome aa3 gene from the archaeon (Archaebacterium) Halobacterium halobium.

A novel aa3-type cytochrome oxidase from the extremely halophilic archaeon, Halobacterium halobium, differs significantly from those of other prokaryotic and eukaryotic cytochrome oxidases (Fujiwara, T., Fukumori, Y., and Yamanaka, T. (1989) J. Biochem. 105, 287-292). In the present study, we cloned and sequenced the gene which encodes the cytochrome aa3 by using the polymerase chain reaction methods. The deduced amino acid sequence of subunit I of H. halobium cytochrome aa3 was more similar to that of subunit I of the eukaryotic cytochrome (44%, maize mitochondria) than that of the cytochrome from other bacteria (36%, Paracoccus denitrificans). The consensus sequence in putative metal binding residues is well-conserved also in H. halobium cytochrome aa3.

Amino Acid Sequence↗
PubMed1991

Functional expression of furin demonstrating its intracellular localization and endoprotease activity for processing of proalbumin and complement pro-C3.

We have cloned a rat cDNA encoding furin which is structurally related to yeast Kex2 protease. Products of 88 and 94 kDa were obtained by in vitro transcription/translation of the cDNA in the absence and presence of microsomes. When the cDNA was transfected into COS-1 cells, furin was expressed as a major glycosylated form of 94 kDa, accompanied by a minor proteolytic form of 86 kDa, and found to be localized in the Golgi complex. Proalbumin and complement pro-C3 are intracellularly processed into their mature forms by cleavage at the dibasic residues Arg-Arg, a common cleavage signal found in many pro-type precursors. In cells transfected with the cDNA of C3 or albumin alone, only about half of each proform expressed was processed by an endogenous activity of the cells. When furin was coexpressed, the proforms of both C3 and albumin were completely processed into their mature forms. In addition, co-expression of rat alpha 1-protease inhibitor mutant (Met352----Arg) resulted in inhibition of the endogenous and exogenous processing activities, as observed for the naturally occurring mutant Pittsburgh which has been identified as a specific inhibitor for the processing enzyme. Taken together, these results indicate that furin is an endoprotease localized to the Golgi complex and capable of processing proalbumin and pro-C3 into the mature forms.

Amino Acid Sequence↗
PubMed1991

Molecular cloning and sequence analysis of cDNAs for five major subunits of human proteasomes (multi-catalytic proteinase complexes).

Proteasomes are multicatalytic proteinase complexes consisting of a set of non-identical polypeptide components. Of these multiple components, the nucleotide sequences of five major subunits (named HC2, HC3, HC5, HC8 and HC9) of human proteasomes have been determined from recombinant cDNA clones by screening a human HepG2 hepatoblastoma cell cDNA library with rat proteasome cDNAs isolated previously as probes. The polypeptides deduced from their nucleotide sequences consisted of 263, 234, 241, 255 and 261 amino acid residues with calculated molecular weights of 29,554, 25,897, 26,487, 28,431 and 29,482, respectively, which are encoded by single independent genes. The primary structures of these subunits of human proteasomes closely resemble those of their rat counterparts and show considerably high inter-subunit homology, although the homology of HC5 is relatively low. These findings, together with the structural similarities of other eukaryotic proteasomes including those of Drosophila and yeast (Saccharomyces cerevisiae) support and extend the previously proposed concept that eukaryotic proteasome genes form a multi-gene family with the same evolutionary origin.

Amino Acid Sequence↗