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Biomedical subjects

Y Yagi

Publications and source records attributed to Y Yagi.

At least 109 records · Page 6Linked to original sources
PubMed1995

Human pulmonary vascular and venous compliances are reduced before and during left-sided heart failure.

Human pulmonary vascular and venous compliances were measured in 41 patients with or without left-sided heart failure. Two methods were used. Method 1 was based on analysis of pulmonary capillary wedge (PCW) pressure tracings according to Cv,PCW = (SF/100)(0.075PCW + 0.90)SV/[(v - d)PCW + 1], where Cv,PCW is compliance of pulmonary venous system, SF is systolic fraction of pulmonary venous flow [related to pulmonary capillary wedge pressure (PCW) as SF = 82 - 2.01PCW], (v - d)PCW is pulse pressure in PCW position, and SV is stroke volume. The (0.075PCW + 0.90) term equals k", i.e., systolic run-off ratio. Method 2 was used to measure to pulmonary vascular volume-pressure (V-P) relationship and pulmonary vascular compliance (Cvasc) and is based on measurement of pulmonary blood volume (PBV) and its increase with passive elevation of the legs to calculate Cvasc. Assuming the proportion of blood entering pulmonary venous system (in increase of PBV) during passive leg elevation to be 0.8, pulmonary venous compliance (Cv,PBV) was calculated as Cv,PBV = 0.8Cvasc. Cv,PCW correlated fairly closely with Cv,PBV (r = 0.81, coefficient of variation = 31%). This fair agreement between two independent methods suggests strongly that both methods may be valid, although other interpretations are possible. Cv,PCW, Cvasc, and Cv,PBV decreased going from New York Heart Association class I to classes II and III. When PBV was plotted vs. PCW, average V-P line for class II patients was flatter and shifted downward to the right compared with that for class I. This suggests pulmonary vasoconstriction as well as other factors. Average V-P line for class III patients is flatter but not displaced compared with that for class II. Another previously reported series of 50 patients, most of whom had ischemic heart disease, are included in this study.

Blood Pressure↗
PubMed1995

Direct sub-Tenon's ocular anesthesia for strabismus surgery.

We assessed the safety and effectiveness of sub-Tenon's anesthesia, a local anesthesia, for strabismus surgery. For 15 surgeries, we used anesthesia by sub-Tenon's infusion, followed by direct infusion through a transconjunctival route with a local anesthetic agent. We found the procedure was simple, it minimized complications compared with other techniques and was effective in achieving rapid anesthesia. With the ocular movement remaining, we checked eye position by the alternative cover-uncover test at the end of surgery. We obtained good eye position for all patients. This method leads to good results for strabismus surgery.

Adolescent↗
PubMed1995

[Efficacy of combination chemotherapy with mitoxantrone, vincristine, prednisolone (MVP) for recurrence of breast cancer].

Fourteen patients with recurrent breast cancer were treated with a combination of mitoxantrone (10 mg/m2 iv, day 1), vincristine (1 mg/m2 iv, day 1) and prednisolone (30 mg/day day 1-7). Cycles were repeated every 4 weeks and all patients received more than 3 cycles. The objective response rate was 70.0% (7 of 10). In two patients, the treatment has been continued now for more than one year. In these 2 patients, the duration of response is more than 40 weeks. The toxicity was primarily myelosuppression. Five of 14 patients (35.7%) had leukopenia of Grade 3 and 4. These patients received G-CSF therapy and recovered well from leukopenia. Nausea and vomiting were well tolerated, probably by prednisolone. This regimen was especially superior in the maintenance of quality of life because hair loss was much less compared to CAF (cyclophosphamide, ADM, 5-fluorouracil) treatment. In conclusion, MVP treatment is highly effective and safe for the treatment of recurrent breast cancer.

Adult↗
PubMed1995

[Saphenous vein to saphenous vein bypass grafting in four redo CABG patients].

In four redo CABG patients, new saphenous vein grafts were anastomosed to the angiographically normal part of the old, and partially narrowed or occluded saphenous vein grafts in an end-to-side fashion. Inner surface of the old saphenous vein was confirmed to be smooth and free of atherosclerotic change during anastomosis. Postoperative course was uneventful and angiography demonstrated the good patency of new saphenous vein grafts in all patients. Although this technique is not acceptable if the old saphenous vein graft shows extensive atherosclerotic change, this method may be a useful alternative in case of limited saphenous vein graft disease in terms of less difficulty and operation time.

Aged↗
PubMed1994

Design and synthesis of seco-oxysterol analogs as potential inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase gene transcription.

The synthesis and biological activity of a series of seco-oxysterol analogs designed to be inhibitors of transcription of the gene for 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGR) are described. The compound possessing the most significant activity, [1 alpha (E),4 beta]-3-[2-(4- hydroxy-1-methylcyclohexyl)ethenyl]-alpha,alpha-dimethylbenzenepentan ol (4, U-88156), inhibited (IC50 = 10 microM) the expression of beta-galactosidase (beta-gal) in a transfected human HepG2 cell line wherein the beta-gal gene was driven by a 5 kB segment of the promoter for hamster HMGR. Furthermore, using wild-type HepG2 cells, it was shown that 10 microM 4 reduced HMGR mRNA levels by 73% while stimulating LDL-receptor activity by 47%. In the same system, the related oxysterol, 25-hydroxycholesterol (1), at 10 microM lowered both HMGR mRNA levels and LDL-receptor activity by 58% and 64%, respectively. Overall HMGR activity in wild-type HepG2 cells was inhibited 30% by 4 at 10 microM. These findings collectively demonstrate that a seco-oxysterol analog is capable of regulating HMGR gene expression and that this regulation can occur without a concomitant attenuation of the level of LDL-receptor activity.

Animals↗
PubMed1994

Assignment of disulfide bond location in prothoracicotropic hormone of the silkworm, Bombyx mori: a homodimeric peptide.

The disulfide bond location of a homodimeric peptide, prothoracicotropic hormone (PTTH) of the silkworm, Bombyx mori, was determined by a combination of partial reduction and sequence analysis of peptide fragments generated through a partial reduction of PTTH followed by alkylation and enzyme digestion. The partial reduction and S-alkylation broke the interchain disulfide bond but did not affect the intrachain disulfide bonds, generating monomeric PTTH whose intrachain disulfide bonds were kept intact. This monomeric PTTH has about one-half the biological activity of intact PTTH. Sequence analysis of the fragments generated by lysyl endopeptidase digestion of this monomeric PTTH after complete reduction and S-alkylation by another S-alkylating reagent showed that only the Cys15 residue was reduced and S-alkylated by the foregoing partial reduction, indicating that this residue formed the interchain disulfide bond. The other disulfide bonds which formed intrachain bridgings were determined by sequence and mass analyses of the fragments generated by two successive enzyme digestions of the monomeric PTTH. In conclusion, the disulfide bond location of PTTH was assigned to Cys15-Cys15' as an interchain disulfide linkage and Cys17-Cys54, Cys40-Cys96, and Cys48-Cys98 as intrachain disulfide linkages.

Amino Acid Sequence↗
PubMed1994

Isolation and characterization of addition products of alpha-tocopherol with peroxyl radicals of dilinoleoylphosphatidylcholine in liposomes.

alpha-Tocopherol was reacted with peroxyl radicals of phosphatidylcholine at 37 degrees C in liposomes. The phospholipid-peroxyl radicals were generated by the reaction of 1,2-dilinoleoyl-3-sn-phosphatidylcholine with a free radical initiator, 2,2'-azobis(2,4-di-methylvaleronitrile), under air. One peak corresponding to the reaction products of alpha-tocopherol with phosphatidylcholine-peroxyl radicals was isolated by reversed-phase high-performance liquid chromatography. Its structure was identified as a mixture of 8a-(phosphatidylcholine-peroxy)-alpha-tocopherones: 1-[9-(8a-peroxy-alpha-tocopherone)-10,12-octadecadienoyl]-2- linoleoyl-3-sn-phosphatidylcholine,1-[13-(8a-peroxy-alpha-tocopherone )-9,11-octadecadienoyl]-2-linoleoyl-3-sn-phosphatidylcholine, 1-linoleoyl-2-[9-(8a, peroxy-alpha-tocopherone)-10,12-octadecadienoyl]-3-sn-pho sph atidylcholine and 1-linoleoyl-2-[13-(8a-peroxy-alpha-tocopherone)-9,11-octadecadi enoyl]-3-sn- phosphatidylcholine. The results indicate that each alpha-tocopherol can trap two peroxyl radicals during the peroxidation of unsaturated phospholipid in liposomes.

Chromatography, High Pressure Liquid↗
PubMed1994

Magnetic resonance imaging and brain-stem auditory evoked potentials in neuro-Behçet's disease.

We studied central nervous system lesions in patients with neuro-Behcet's disease using magnetic resonance imaging (MRI) of the brain and recording of brain-stem auditory evoked potentials (BAEPs). MRI revealed abnormal findings in seven of eight patients. MRI studies demonstrated extensive regions with high intensity signal in the brain stem and/or basal ganglia on T2-weighted images obtained during the acute stage of the disease in three patients. One of these patients had a strongly gadolinum-enhanced round lesion in the lower pons. In four of the other five patients with chronic disease, brain-stem atrophy was observed on T1-weighted images. Atrophic changes were more severe in the brain stem than in the cerebellum. Abnormal BAEPs were observed in three patients and consisted of prolongation of interpeak latency of waves III-V and defects of wave III or V. Abnormal BAEPs were recorded in patients with severe inflammatory changes or progression of atrophic changes in the brain stem. Our findings show that MRI and BAEPs are useful in detecting the presence and assessing the degree of neurological involvement in patients with neuro-Behçet's disease.

Adult↗
PubMed1994

Quantitative evaluation of postsurgical inflammation by infrared radiation thermometer and laser flare-cell meter.

Using an infrared radiation thermometer and a laser flare-cell meter, we evaluated intraocular inflammation in 40 patients who had cataract surgery by measuring central corneal temperature, number of cells, and amount of flare in the anterior chamber. Patients were divided into two groups based on duration of surgery: Group A, more than 40 minutes; Group B, less than 40 minutes. In Group A (n = 32), corneal temperature (degrees Celsius) increased by 1.10 +/- 0.57, 0.75 +/- 0.69, 0.41 +/- 0.56, and 0.24 +/- 0.45 on days 1, 2, 14, and 30, respectively. Group B (n = 8) had no significant rise in corneal temperature, but cell count (mean +/- 1 SD) increased to 39.3 +/- 13.6, 36.4 +/- 18.1, 15.5 +/- 16.5, and 4.4 +/- 3.1 on days 1, 2, 7, and 14, respectively. Flare increased to 88.9 +/- 88.9, 45.8 +/- 30.1, 38.3 +/- 25.4, and 18.5 +/- 9.4 on days 2, 7, 14, and 30, respectively. These observations show that the longer the cataract surgery, the greater the inflammation. Although inflammation was evaluated quantitatively by both infrared radiation thermometer and laser flare-cell meter, the latter appears to be more sensitive. Thermometry will only detect the results of very traumatic surgery, with a corresponding breakdown of the blood-aqueous barrier.

Anterior Chamber↗
PubMed1994

Three different types of dry eye syndrome.

We analyzed patients with dry eye syndrome with regard to autoimmune conditions. A total of 116 patients with dry eye syndrome were divided into three groups: simple dry eye (SDE), i.e., dry eye with no circulating autoantibodies; autoimmune positive dry eye (ADE), dry eye with circulating autoantibodies; and Sjogren's syndrome (SS), dry eye associated with Sjogren's syndrome. Schirmer test showed values of 3.0 +/- 2.2 mm in SDE, 3.1 +/- 2.0 mm in ADE, and 2.4 +/- 2.3 mm in SS reflecting the inadequacy of this test in differentiating among the groups. However, Schirmer test with nasal stimulation showed values of 19.1 +/- 12.4 mm in SDE and 16.4 +/- 10.9 mm in ADE, which were significantly higher than the 7.0 +/- 6.6 mm found in SS (p < 0.01). Moreover, ocular surface alterations evaluated by vital staining and brush cytology were significantly milder in SDE and ADE than in SS. SDE and ADE have less ocular surface abnormalities with good reflex tearing, whereas SS has less reflex tearing and more squamous metaplasia.

Adult↗
PubMed1994

Comparison of displacemental potencies of terazosin enantiomers for alpha 1-adrenoceptor subtypes.

The present study was designed to assess displacemental potencies of terazosin and its isomers for alpha 1 High and alpha 1 Low adrenoceptor subtypes in rat brain, heart, bovine prostate and canine aorta using a radioligand binding assay method. Although no significant difference in pKi values of each terazosin isomer for alpha 1 High in canine aorta and rat brain were observed, the displacemental potency of (S-)terazosin for those in rat heart and bovine prostate was stronger than that of (R+)isomer (p < 0.01). On the other hand, only in alpha 1 Low subtypes of bovine prostate was stronger displacemental potency of (S-)terazosin than (R+)isomer (p < 0.05) observed. Thus, these results imply that there is a different affinity between (S-)terazosin and (R+)isomer on the alpha 1 High in bovine prostate and rat heart and alpha 1 Low in bovine prostate.

Animals↗
PubMed1994

Effects of 2,5-hexanedione on rat spinal pyramidal tract.

The present study was undertaken to investigate central axonal neuropathy caused by 2,5-hexanedione (2,5-HD) administration. The effects of 2,5-HD on rat pyramidal tract were studied electrophysiologically and histopathologically. Male rats were given 0.5% 2,5-HD in their drinking water for 4, 6 or 8 wk. Spinal motor conduction velocity was measured by direct electrical stimulation and was examined histopathologically by electron microscopy. Rats treated with 2,5-HD had reduced spinal motor conduction velocity at 6 wk and their pyramidal tract axons had decreased cross-sectional areas at 4 wk. The mean number of neurofilaments in myelinated axons of rats treated with 2,5-HD for 8 wk was 42.1% of that found in control rats, but the number of microtubules was not significantly different. The ratio of neurofilaments to microtubules in rats treated with 2,5-HD for 4 wk was less than 1.0 in 30.9% of myelinated fibers, while in control rats it was greater than 1.0 in all axons. These changes in spinal pyramidal tract were detected relatively early after 2,5-HD administration. These results in rats indicate the need for further studies of 2,5-HD neurotoxicity in the human central nervous system.

Animals↗
PubMed1994

[The mechanism of biochemical modulation in methotrexate/5-fluorouracil sequential chemotherapy].

5-fluorouracil (5-FU)/methotrexate (MTX) sequential chemotherapy is one of the standard regimen for the treatment of gastric cancer. Though this combination therapy is highly effective, the mechanism is still unclear. In this study, we investigated the relationship between antitumor activity and the inhibition of thymidylate synthase and between antitumor activity and incorporation of 5-FU into RNA (F-RNA) in mice bearing Sarcoma-180 treated by tegafur alone (100 mg/kg) or by the combination of MTX (42 mg/kg) and tegafur (100 mg/kg). A new method for the determination of F-RNA of tumor tissue samples was used. Briefly, RNA fractions containing incorporated 5-FU were extracted by KOH hydrolysis. FUra in RNA fractions was released by HCl hydrolysis and its levels were determined by GC-MS. The results showed that the F-RNA levels were significantly elevated by the pretreatment of MTX. According to this result, it is suggested that the measurement of F-RNA levels together with the determination of FUra concentration and the inhibition rate of thymidylate synthase were considered as a good means for the evaluation of antitumor efficacy of FUra. We concluded that the impairment of RNA metabolism played a major role in the antitumor activity of MTX/5-FU combination.

Animals↗
PubMed1994

[A case report of surgical treatment for coronary aneurysm following repeated PTCA].

A 53-year-old man who developed coronary artery aneurysm following repeated percutaneous transluminal coronary angioplasty (PTCA) was reported. At the first coronary angiography, the severity of coronary stenosis was 95% at areas #6 and #7. The first PTCA provided sufficient coronary dilatation, but 3 months later, PTCA was needed again because of the recurrence of stenosis. This second PTCA provided sufficient dilatation, but the coronary dissection remained. Eight months after the second PTCA, the patient suffered from recurrent angina. The repeated coronary angiography showed 95% stenosis of the original lesion and coronary aneurysm formation (4 mm in diameter) at the area of dissection which developed at the former PTCA site. Therefore, coronary artery bypass surgery with left internal thoracic artery to area #8 was performed.

Aortic Dissection↗
PubMed1994

[Emergency coronary artery bypass grafting for left main trunk stenosis in a patient with systemic lupus erythematosus].

A 57-year-old female who had been treated for SLE with prednisolone for 11 years was transferred to our hospital due to unstable angina caused by stenoses of the left main trunk (LMT) and the left anterior descending artery (LAD). She underwent emergency coronary artery bypass grafting of the LAD and the left circumflex artery (LCX) using saphenous vein grafts (SVGs). Since we were afraid the internal thoracic arteries (ITAs) and right gastroepiproic artery were less usable because preoperative angiography showed too small (1.2 mm) ITAs and she had undergone Miles' operation for anal canal cancer, SVG usage seemed more advantageous as an emergency procedure. Pre- and postoperatively, leukocytopenia was treated with granulocyte colony stimulating factor and she was free from infection. She had no chest pain postoperatively. However, postoperative angiography confirmed an occluded SVG to the LCX and a patent SVG to the LAD which supplied blood flow to the LCX area.

Aged↗