Biomedical subjects

S Tahara

Publications and source records attributed to S Tahara.

At least 73 records · Page 4Linked to original sources

PubMed1997

[Postoperative three-dimensional CT angiography (3D-CTA) in evaluation of proximal clipping for ruptured vertebral aneurysms].

At present, intra-arterial angiography remains the gold standard for most cerebrovascular problems. Recently, three-dimensional computed tomographic angiography (3D-CTA) has been reported as a screening method for the diagnosis of cerebrovascular disease. This imaging modality uses the information obtained on a contrast-enhanced CT scan to generate three-dimensional images of the cerebrovascular system. We performed 3D-CTA in the preoperative and postoperative evaluation of patients undergoing proximal clipping of ruptured vertebral artery aneurysms in addition to conventional cerebral angiography. In this study, the value of 3D-CTA after proximal clipping of ruptured vertebral artery aneurysm was evaluated retrospectively. Six patients were examined with a spinal CT (HITACHI CT-W 3000) after intravenous bolus injection of 100 ml contrast material (Iohexhol 300 mgI/ml) at the rate of 2 ml/s with a 25 second pre-scanning delay. The images of 3D-CTA were reconstructed using a new 3D-volume-render (Voxel Transmission) technique. The ages of the six patients ranged from 33 to 61 years and five cases were males and one case was female. Only one patient had a saccular aneurysm and the other five had fusiform aneurysms. Two patients underwent emergency operations within 4 days, and the other four had delayed operations. The outcome was good recovery in five cases and severe disability in one case. Postoperative conventional cerebral angiography demonstrated no delineation of the aneurysms in five cases. These results correspond well to postoperative 3D-CTA. Postoperative conventional cerebral angiography could not be performed in only one patient, but the aneurysm was visualized on the third postoperative 3D-CTA. Proximal clipping is still one of the therapeutic options for ruptured vertebral aneurysms, but some reports emphasized the possibility of rebleeding after proximal clipping of vertebral artery aneurysms. The rebleeding occurred within 1 week after proximal clipping in 6 of 9 cases (66.7%), and the prognoses were extremely poor. Therefore, in patients selected for proximal clipping, it is necessary to undertake postoperative evaluation of the aneurysm within one week after proximal clipping. 3D-CTA is minimally invasive and can be easily performed repeatedly, even if the patients are in a poor condition. In conclusion, 3D-CTA is very useful especially for evaluation of ruptured vertebral artery aneurysms following proximal clipping.

Adult↗

PubMed1996

Non-linear accumulation of 8-hydroxy-2'-deoxyguanosine, a marker of oxidized DNA damage, during aging.

Damage to DNA seems to be involved in aging and the etiology of age-associated degenerative diseases. The purpose of this study is to examine changes in DNA damage during aging. An oxidized nucleoside, 8-hydroxy-2'-deoxyguanosine (8-OHdG), is a proposed biomarker for DNA damaged by oxidative stress. The content of 8-OHdG in nuclear DNA isolated from brain, heart, liver, and kidneys of male Fischer 344 rats of different ages was measured, 8-OHdG can be detected selectively and sensitively at the fmol level by high performance liquid chromatography-electrochemical detection at an applied potential of +350 mV. The amount of 8-OHdG, expressed as the ratio to deoxyguanosine in nuclear DNA, in heart, liver, and kidney remained steady from 2 to 24 months and then increased progressively. The content of 8-OHdG in the DNA in brain showed no changes from 2 to 27 months, but was significantly higher in 30 month-old rats. There was a significant 2-fold increase in the amount of 8-OHdG in the nuclear DNA of all organs tested in 30 month-old rats as compared to 2-24 month-old rats. These results indicate that the accumulation of 8-OHdG in the DNA of rat organs begins at ages above 24 months.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed1996

[Pleural fibroma with a cavity-like air space].

A 45-year-old man was admitted to the hospital because of an increase in the size of an abnormal shadow on chest X-ray films over the preceding 5 years. A chest X-ray film on admission revealed a round air space in a mass-like shadow in the right upper lung field. Results of physical examination, sputum cytologic examination, and Ziehl-Neelsen staining were negative. Histopathological examination of a percutaneous lung biopsy specimen revealed a benign fibrous tumor of the pleura. Thoracotomy revealed a pedunculated tumor arising from the visceral pleura at the apical segment of the right upper lobe. A wedge resection was done. Histological examination revealed that the tumor consisted of regularly-shaped spindle cells with densely collagenous tissue. Normal lung tissue was found to be invaginated into the tumor tissue. These findings are consistent with the radiologic findings.

Fibroma↗

PubMed1995

Role of the perforating vein in vascular pedicle of free forearm flap.

An innovation in the preparation of the vascular pedicle of the free radial forearm flap is presented. While the radial artery is commonly used as the arterial pedicle of the flap, either the cutaneous venous system or the radial comitant vein (deep venous system) is used as the venous pedicle. The perforating vein communicates between these two venous systems at the cubital fossa, and we confirmed its presence in all but one of more than 180 cases. When the vascular pedicle is dissected proximally to the perforating vein contained in the flap, the venous drainage of both the deep and cutaneous systems can be restored by anastomosis of only one vein: the cutaneous or the radial comitant vein. On the other hand, the flap can be raised with the radial vessels (without the cutaneous vein) at the start of surgery, and a large caliber cutaneous vein, such as the median cubital, the cephalic, or the basilic, can be used for anastomosis in cases where the cutaneous veins in the distal forearm are too thin, or where the radial comitant vein is composed of two thin separated veins. We believe that preserving the perforating vein would make the forearm flap more reliable and more convenient in reconstructive surgery.

Forearm↗

PubMed1995

Antimicrobial stress compounds from Hypochoeris radicata.

The exudates of Hypochoeris radicata leaves stressed with cupric chloride afforded two eudesmane- and guaiane-type sesquiterpenes, and two alkenals, (2E,4E)-6-hydroxyhexadienal and (2E,4E)-hexadienedial (mucondialdehyde). Their structures were determined by spectroscopic and synthetic methods.

Antifungal Agents↗

PubMed1994

Carbohydrate antigens recognized by anti-horseradish peroxidase antiserum are expressed on mammalian cells.

Antiserum raised against horseradish peroxidase (HRP) recognizes neural specific carbohydrate antigens in Drosophila and other insects. The occurrence of the antigens in mammalian cells was investigated. Proteins were extracted from rat pheochromocytoma cells, PC12, and various tissue of rat and bovine origin, and further purified by successive chromatography with Con A-Sepharose and anti-HRP glycopeptide antibody-Sepharose. The proteins were separated by SDS-PAGE and subjected to immunoblot analysis of the antigens. When the Con A- and antibody-Sepharose bound fractions were examined, four glycoproteins with carbohydrate antigens recognized by anti-HRP antiserum were identified in all the tissue. They are low molecular weight glycoproteins that are not membrane-bound. We demonstrated that the carbohydrate antigens recognized by the anti-HRP antibodies are not confined to insects but are expressed on mammalian cells in several tissue.

Adrenal Gland Neoplasms↗

PubMed1994

Identification of mucondialdehyde as a novel stress metabolite.

In a survey of antifungal stress compounds induced by cupric chloride we found that leaves of Chenopodium album exuded a highly fungitoxic metabolite mucondialdehyde (trans-2,trans-4-hexadienedial), which was associated with 13-oxo-9,11-tridecadienoic acids (cis-9,trans-11 and trans-9,trans-11 isomers) presumably resulting from beta-scission of 13-hydroperoxy-octadecadi(tri)enoic acid. The biogenesis and role as a general defensive agent in plants are briefly discussed.

Aldehydes↗

PubMed1994

Prenylated flavonoids in the roots of yellow lupin.

A further investigation of the methanol-soluble compounds in yellow lupin roots has revealed a new diprenylchromone, a new coumaronochromone (lupinalbin H), a new isoflavone 5,7,4'-trihydroxy-8,3'-di-(3,3-dimethylally)isoflavone (isolupalbigenin), and some complex flavanones. The latter compounds have been identified as two known diprenylated flavanones (lonchocarpol A and euchrestaflavanone A), two diasteroisomeric pairs of dihydrofuranoflavanones (lonchocarpols C1 and C2, and lonchocarpols D1 and D2, the structures formerly proposed for lonchocarpols C and D were also reinvestigated), a new furanoflavanone (lupinenol), and three 8-prenylflavanones with an additional (2RS)-hydroxy-3-methyl-3-butenyl side chain. The structures of the latter flavanones were unambiguously identified by spectroscopic (1H NMR) comparison with 6-, 8- and 3'-prenylnaringenins chemically prepared from (2S)-naringenin. The antifungal activity of the prenylated naringenins, and of the various yellow lupin flavanones, was determined by TLC place bioassays using Cladosporium herbarum as the test fungus.

Chromatography, Thin Layer↗

PubMed1994

[A case report of primary fibrosarcoma originated in the heart invading adjacent organs ].

A rare case of cardiogenic fibrosarcoma is reported. A 66 y.o. male with dyspnea, cough and fatigue was examined. B-mode echo, MRI, and angiography disclosed a large tumor in the left atrium. A large fibrosarcoma and 2 cm of the left atrial wall around the tumor pedicle were removed. The atrial defect and right lower pulmonary vein were repaired with a patch. Four months later, the tumor recurred in the right lung, mediastinum, and left atrium. The tumor, middle and lower lobes of the right lung, and part of the left atrial wall were excised. One year after the first operation, the patient died of air way obstruction due to another recurrence of the fibrosarcoma in the left lung, esophagus, and mediastinum. Cardiogenic fibrosarcoma invading outward for the mediastinal organs is rare.

Aged↗

PubMed1993

Effects of mouse hepatitis virus infection on host cell metabolism.

A time dependent decrease in cell surface expression of major histocompatibility complex (MHC) class 1 proteins was found during JHMV infection of the mouse macrophage J774.1 cells line by radioimmunoassay. MHC class I, actin and CSF-1 receptor mRNA levels were also found to decrease during infection. Surprisingly, not all host cell mRNA were similarly affected, suggesting that the apparent MHV-induced translational shut off of host cell protein synthesis during infection was specific for only some host cell mRNAs. Interestingly, two mRNAs found to be refractory to JHMV infection encode monokines, suggesting a role in pathogenesis. To understand the mechanism(s) of this preferential mRNA stability and the apparent shut off of host cell mRNA, translation lysates were prepared from infected and uninfected cells. Translation of host mRNAs in these extracts showed no apparent loss of translational ability in the infected cells vs. the uninfected cells; however, viral mRNAs were preferentially translated in the lysates from the infected cells. Chimeric mRNAs containing the MHV leader upstream of a globin reporter gene showed that preferential translation was a property of the MHV leader RNA. Deletional analysis showed that the sequences responsible for this cis translational augmentation are in a 12 nucleotide (nt) tract at the 3' end of the leader. The previously reported interaction of the nucleocapsid protein with these nts suggest that it may play a role in translational augmentation of MHV mRNAs.

Animals↗

PubMed1993

Dental implantation to free scapular bone flap used for mandibular reconstruction.

Three patients who underwent mandibular reconstruction with a free vascularized scapular osteocutaneous flap after tumor resection are presented. Dental reconstruction was performed on three patients by implanting an artificial dental root into the grafted bone. The procedures for dental implantation were done just as on a normal jaw, and did not require hospitalization of the patients. They were followed up for 3 to 5 years after dental reconstruction. They have been able to masticate and ingest in a virtually normal manner during these periods. They also showed good appearance of the reconstructed mandible and dentes. On the basis of these results, the indication and evaluation of this procedure are discussed.

Adolescent↗

PubMed1993

[Peri- and postoperative management in one staged operation of cardiac disease combined with pectus excavatum].

Patients with pectus excavatum occasionally have coexisting surgical heart disease. During a 10-year period up to the end of 1988, we surgically treated a total of 2015 cases of pectus excavatum, including 12 cases with one staged operation for pectus excavatum and heart disease. Proving the advantage of our one staged operation for the coexisting diseases we studied data resulting from the perioperative management in the group of one staged operations (n = 5), and in the other group of single valve replacement (n = 10). Operative time, amount of operative blood loss and total amount of transfused blood, were 433 +/- 66 min. (mean +/- SD), 3180 +/- 1867 ml and 4836 +/- 2247 ml, in the former group (n = 5), respectively. These data were almost similar to those in the latter group (n = 10). Postoperative ventilatory support time and ICU stay time also showed little difference between two groups. We conclude these data supports our previous report that one staged operation has no perioperative disadvantage in the surgical treatment of patients with both cardiac disease and pectus excavatum.

Adolescent↗

PubMed1992

Biosynthesis of White Lupin Isoflavonoids from [U-C]l-Phenylalanine and Their Release into the Culture Medium.

Pulse-labeling experiments of white lupin (Lupinus albus L.) cell cultures with [U-(14)C]l-phenylalanine for 72 h resulted in the incorporation of the radioactivity into the isoflavone aglucones, glucosides, and prenylated derivatives. Both the aglucones genistein and 2'-hydroxygenistein and their 7-O-glucosides accounted for 85% of the total isoflavonoids identified in the cultured cells and contained 35% of the radioactivity, whereas the prenylated derivatives comprised 15 and 65%, respectively. Almost 20% of the labeled isoflavones of the cellular pool was recovered from the culture medium, 90% of which were monoprenylated and diprenylated derivatives containing 80% of the radioactivity. These results clearly demonstrate the release into the culture medium of a substantial amount of the endogenously synthesized isoflavonoids, especially the prenylated derivatives.

Journal Article↗

PubMed1992

Report of a study using phantom materials, and clinical experience with simultaneous radio-hyperthermotherapy.

Simultaneous radiohyperthermotherapy (SRH) is a combined hyperthermia-radiation therapy in which irradiation is given during heating. Mutual interference between the high energy radiotherapy system (Toshiba LMR-15A) and the 13.56 MHz capacitive heating system (Omron HEH-500C) was tested with phantom materials prior to a clinical trial with SRH. The energy and flatness of irradiation were not affected by the heating system within the range of clinical use. The high energy radiotherapy system did not affect the increase or distribution of temperature during simultaneous treatment. The results of this phantom study indicated that these apparatuses would not produce clinically significant mutual interference during SRH. A clinical trial was performed on a 57-year-old woman with postoperative recurrence of rectal cancer. This is the first reported clinical case treated with true SRH in which external irradiation was administered during mid capacitive heating. Twelve SRH treatments were performed on the recurrent lesion at a frequency of twice a week for six weeks using the apparatuses described above. There was a significant reduction in pain after treatment. The tumor marker carcinoembryonic antigen (CEA) level decreased after treatment. On CT images taken after treatment, the tumor site became a low density area which indicated necrosis. There were no side effects. These results suggest that further clinical study of SRH should be performed to clarify its advantages.

Body Temperature Regulation↗

PubMed1992

[Microsurgical autotransplantation of abdominal testis].

A 32-year-old man who had bilateral non-palpable testis underwent microsurgical orchidopexy of the right abdominal testis. Inferior epigastric vessels were used for the recipient vessels. Ischemic time during the operation was 40 minutes. Postoperative doppler readings revealed excellent blood flow to the testis, and HCG-stimulating test revealed good response. Now, 2 years after surgery, no sign of atrophy is found.

Adult↗

PubMed1991

New perylenequinones from Shiraia bambusicola.

Two new perylenequinones, named hypocrellin B and C, together with the known hypocrellin A were isolated from the stromatal tissues of Shiraia bambusicola. The structures of these compounds, including the absolute stereochemistry, were determined.

Ascomycota↗

PubMed1991

Primary tracheojejunal shunt operation for voice restoration following pharyngolaryngoesophagectomy.

A primary tracheojejunal shunt operation was performed for voice restoration following pharyngolaryngoesophagectomy with free jejunum reconstruction for advanced hypopharyngeal cancer. A fistula was created between the membranous part of the trachea and the lower part of the transplanted jejunum. The membranous part of the trachea was tubed to construct the tracheojejunal shunt. All three patients who had the tracheojejunal shunt operation retained phonatory function. Pitch formation was seen in the voice waveform with use of the tracheojejunal shunt. No leakage was seen at all during deglutition and a swallowing function was obtained in all patients who had the tracheojejunal shunt.

Aged↗

PubMed1991

[Articulatory evaluation after mesopharyngeal reconstruction with the radial forearm flap].

Soft palate and tonsil (mesopharynx) play an important role on articulation and swallowing. We must take care not to restrict these physiological function when we reconstruct the mesopharyngeal defect after cancer ablation. In order not to restrict the postoperative function of mesopharynx, we take it the more important to preserve the function of the residual tissue rather than to rebuild the lost function. We took notice of pliable nature of the radial forearm flap and tried to reconstruct mesopharyngeal defect in five cases with this flap. We analyzed articulatory function and velopharyngeal closure in these cases, postoperatively. Articulatory function was assessed on the results of intelligibility test with 100 Japanese monosyllables. In four cases out of five, about 70% of syllables were accurately heard. According to the Hirose's standard of speech function after the operation of oral and/or oropharyngeal cancer, those four cases were evaluated also to be excellent. Whether the resection was done beyond the uvula or not, proved not to have anything to do with the postoperative speech intelligibility. Although speech intelligibility once went down immediately after the operation, it improved around six months later. The improvement might be due to the following facts; The forearm flap was cicatrized postoperatively, disturbing the mobility. After the softening of the cicatrix began, the flap gradually recovered flexibility, which enabled surrounding structure to move more smoothly. Articulatory dysfunction was characterized as plosives tend to be misunderstood as nasals or affricates. Concerning nasality, the velopharyngeal closure was examined by fiberscope. Perfect closure was seen in two cases, near-perfect in two cases, and insufficient in one case.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗