Search PubMed⌕ Search

Biomedical subjects

Y Fujimoto

Publications and source records attributed to Y Fujimoto.

At least 271 records · Page 15Linked to original sources
PubMed1994

Test performances of three diagnostic procedures in evaluating thyroid nodules: physical examination, ultrasonography and fine needle aspiration cytology.

A retrospective study was performed to determine the reliability of physical examination (PE), ultrasonography (US) and fine-needle aspiration cytology (FNA) in the evaluation of thyroid nodules. Preoperative diagnoses of 252 euthyroid patients comprised 126 with benign lesions, 114 with papillary carcinoma and 12 with follicular carcinoma made by PE, US and FNA were reviewed. The specificity of PE, US and FNA for malignancy was 98%, 90% and 98%, respectively. The sensitivity of PE, US and FNA for malignancy was 63%, 78% and 80%. The sensitivity for papillary carcinoma of the three procedures was 68%, 83%, 88%, whereas that for follicular carcinoma was 25%, 25%, 8%, respectively. When all the test results were negative, the likelihood ratio favoring papillary carcinoma was 0.008 whereas that favoring follicular carcinoma was 0.6. The histological category of carcinoma should be considered when evaluating diagnostic procedures for thyroid nodules. No negative test result is conclusive for ruling out the possibility of follicular carcinoma.

Biopsy, Needle↗
PubMed1994

[A study on predicting factors of the effect of intra-arterial infusion chemotherapy in patients with bladder cancers: the usefulness of in-vitro chemisensitivity test measuring intracellular ATP contents (ATP assay)].

We studied a relationship between in vitro sensitivity of the tumors to anti-cancerous drugs and histopathological effectiveness of an intra-arterial infusion chemotherapy in 15 patients with bladder cancers. The in vitro sensitivity test was performed by measuring intra-cellular ATP contents (ATP assay). The intra-arterial chemotherapy were performed by injecting methotrexate (MTX), adriamycin (ADM) and eisplatin (CDDP) from the internal iliac artery. When the intra-cellular ATP contents of the tumor cells treated with an anti-cancerous drug decreased to less than 50% of the untreated tumor cells, the tumor was evaluated as sensitive to the drug. The effectiveness of the chemotherapy were histopathologically evaluated by a pathologist according to the response criteria for bladder cancer treatment. When the histopathological responses of higher than grade 2 were observed in the tumor, the chemotherapy was evaluated as effective. In 8 of 9 tumors sensitive to ADM, chemotherapy were effective histopathologically and in all 6 tumors resistant to ADM, histopathological response of the chemotherapies were poor. The overall coincidence ratio between sensitivity to ADM and the histopathological effectiveness of the chemotherapy was 93%, showing statistically significant correlation. In 7 of 12 tumors sensitive to CDDP, the chemotherapies were effective and in 2 of 3 tumors resistant to CDDP, the chemotherapies were ineffective. Although the overall coincidence ratio between the sensitivities to CDDP and chemotherapeutic effectiveness was 60%, there was no significant correlation between them. In 7 of 8 tumors sensitive to both of ADM and CDDP, the chemotherapies were effective and in 6 of 7 tumors resistant to at least one of them, the chemotherapies were ineffective. (ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1994

Multidrug resistance gene and P-glycoprotein expression in anaplastic carcinoma of the thyroid.

The resistance of malignant tumors to chemotherapy with anticancer drugs has been considered to be due partly to overexpression of the multidrug resistance gene (mdr1) and its gene product, P-glycoprotein (P-GP), which acts as a drug efflux pump for several chemotherapeutic agents. In order to elucidate the mechanism of anticancer drug resistance in anaplastic thyroid carcinoma with very poor prognosis, we examined the expression of mdr1 mRNA and P-GP, and analyzed their relationships to chemotherapy response. Twenty surgical samples from 16 patients with anaplastic thyroid carcinoma were used. The mdr1 mRNA expression was examined by reverse transcription and polymerase chain reaction, and P-GP expression was evaluated by an immunohistochemical method using JSB-1 monoclonal antibody. Of the 20 clinical samples, expression of mdr1 mRNA and P-GP was observed in three and four samples, respectively. Three of the patients from whom the samples were obtained had been given anticancer drugs before biopsy. Of 12 patients who received chemotherapy for clinically evaluable diseases, 2 responded well, but 10 showed no response. All except one patient died of cancer progression. There was no relationship between the response to chemotherapy and the expression of mdr1 and P-GP. The expression of mdr1 mRNA and/or P-GP was observed in 5 of 16 patients with anaplastic thyroid carcinoma. However, the appearance of anticancer drug resistance in anaplastic thyroid carcinoma may not be explained solely by the expression of mdr1 and P-GP.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

[A rare case of high cervical spinal cord dural arteriovenous fistula presenting with intracranial subarachnoid hemorrhage].

It is now recognized that spinal dural arteriovenous fistula causes myelopathy, resulting from congestive venous hypertension of the spinal cord. We have recently encountered a rare case of high cervical spinal cord dural arteriovenous fistula which caused intracranial subarachnoid hemorrhage. The patient was a 62-year-old female, who had exhibited an abrupt onset of severe headache and loss of consciousness. Plain head CT scan revealed intracranial subarachnoid hemorrhage. No abnormal vascular lesions were found on the first cerebral angiography. The second angiographical examination demonstrated a spinal arteriovenous malformation at the high cervical region. A dural arteriovenous fistula around the right C2 nerve root was found by surgical intervention. The fistula was recognized between rt. C2 radicular artery and dural sheath of rt. C2 nerve root, draining to the epidural plexus and intradural local medullary vein. No serpentine coronal venous plexus on the dorsal aspect of the cervical cord was seen as it is in a usual dural type of spinal arteriovenous fistula. The bleeding point was an intradural varix of the medullary vein just where it penetrated the nerve root area. Feeder ligation of the C2 radicular artery and coating of the varix complex were performed. The postoperative course was uneventful. The patient was discharged from our institute with no neurological deficits.

Arteriovenous Fistula↗
PubMed1994

High density lipoprotein inhibits platelet 12-lipoxygenase activity.

The effects of high density lipoprotein (HDL) and low density lipoprotein (LDL) on the formation of 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE), thromboxane (TX) B2 and 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) in washed rabbit platelets were examined. HDL had a powerful inhibitory effect on 12-HETE formation, while it produced only a small increase in TXB2 and HHT formation. LDL did not affect the formation of 12-HETE, TXB2 and HHT. These results suggest that HDL is a selective inhibitor of platelet 12-lipoxygenase and may play a protective role in atherogenesis by preventing the generation of 12-HETE.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1994

[Aberrations of tumor suppressor genes in hepatocellular carcinomas].

Mutation of the p53 gene and loss of heterozygosity of the p53, Rb, APC, and MCC genes were examined in 14 hepatocellular carcinomas (HCCs) diagnosed at the third department of internal medicine in Asahikawa Medical College. Mutations in the p53 gene were detected in 4 HCCs out of 14 (25%) using polymerase chain reaction-single strand conformational polymorphism. The sites of the mutations showed a random distribution from exon 6 to 8. No mutation was observed at codon 249, which has been considered as a mutational hot spot caused by aflatoxin B1. All of the mutations occurred at a G:C base pair site, while two mutations were C:G to T:A transitions and other two mutations were G:C to T:A transversions. Pathological examination showed that the 14 HCCs consisted of 7 moderately and 7 poorly differentiated HCCs. All of the 4 HCCs which showed mutations were poorly differentiated and the frequency of the mutations were 0% in moderately and 57% in poorly differentiated HCCs. Loss of heterozygosity of the p53, Rb and APC genes were examined in the 14 HCCs using restriction fragment length polymorphism analysis. Frequencies of the loss of the p53, Rb, APC, and MCC genes were 2 out of 7 informative cases (2/7), 1/6, 0/4, and 0/7, respectively. Frequency of loss of the p53 gene in four HCCs carrying a mutated p53 gene was 1/3. These data suggest that inactivation of the p53 gene is involved in human hepatocarcinogenesis, but the APC/MCC genes are not.

Adult↗
PubMed1994

Effect of 13-hydroperoxyoctadecadienoic acid on prostaglandin synthesis in rabbit kidney medulla microsomes.

The effect of 13-hydroperoxyoctadecadienoic acid (13-HPODE) on the synthesis of prostaglandins (PGs) was examined in rabbit kidney medulla microsomes. Medulla microsomes were incubated with arachidonic acid in 0.1 M-Tris/HCl buffer (pH 8.0) containing reduced glutathione and hydroquinone and the PGE2, PGF2a and PGD2 formed were measured by high-pressure liquid chromatography using 9-anthryldiazomethane for derivatization. Under our incubation conditions rabbit kidney medulla was found to produce mainly PGE2. The addition of 13-HPODE inhibited the production of all three PGs to a similar extent. 13-Hydroxyoctadecadienoic acid did not suppress the formation of PGs, indicating the requirement of the hydroperoxy moiety for the inhibitory effect of 13-HPODE on PG formation. Experiments utilizing the native fatty acid linoleic acid and tert-butyl hydroperoxide suggested the importance of the fatty acid-derived hydroperoxide in PG synthesis by kidney medulla. We conclude that 13-HPODE is an inhibitor of renomedullary cyclooxygenase and may have functional effects within the kidney.

Animals↗
PubMed1994

Blood supply of the parathyroid gland from the superior thyroid artery.

BACKGROUND: There is considerable controversy about the arterial supply to the superior parathyroid glands. Knowledge of this blood supply should be important for the surgeon performing thyroid and parathyroid operations. The purpose of this investigation was to document whether the superior parathyroid glands receive their blood supply from the superior thyroid artery. METHODS: We injected contrast material into the superior thyroid artery in 52 cadavers and determined the arterial blood supply to the parathyroid glands by using a dissecting microscope. RESULTS: The upper parathyroid gland was identified in 51 instances and the upper and lower glands in 26 instances on the side of injection. Of 92 parathyroid glands identified, 57 glands (62%) had a single artery, 26 (28%) had two, and 9 (10%) had three or more arteries. In 9 (45%) of the 20 cases specifically examined, a distinct anastomosing branch was identified between the inferior and the superior thyroid arteries, from which the upper parathyroid artery arose. CONCLUSIONS: Our study documented that the superior thyroid artery almost always supplies the upper parathyroid glands. Forty-five percent of the subjects had a distinct anastomosing branch between the superior and inferior thyroid arteries, which should be kept intact at operation to preserve the upper parathyroid function. One third of the parathyroid glands have two or more parathyroid arteries.

Arteries↗
PubMed1994

[Clinical investigation of clean intermittent catheterization].

We evaluated 120 patients with neurogenic bladder treated by clean intermittent self catheterization (CIC) in our department. These cases were divided into 2 groups: early treatment cases in which CIC started within 1 year after onset of dysuria, and late treatment cases in which CIC started after more than 1 year. Urinary tract infections (UTI) were recognized in 35% of the early treatment cases and 80% of the late treatment cases in the subsequent period. Pyelonephritis was experienced in 4% of the early treatment cases and 12% of the late treatment cases. Antibiotics therapy was considered unnecessary for asymptomatic UTIs. After CIC treatment, hydronephrosis detected by intravenous pyelography (IVP) and ultrasonography was improved in 18 of the 20 cases, and no cases showed deteriorated renal function. In the cases with neurogenic bladder after radical operations of the uterus or rectum, 45% of the early treatment cases have become free from CIC within 3 months postoperatively, and 84% eventually became free. Most of the late treatment cases have been continuing CIC. We considered that CIC was unnecessary when the residual urine was less than 100ml based on the periodical urinalysis and observation of renal function.

Adolescent↗
PubMed1994

Myxoma of the maxilla.

A case of myxoma, arising in the maxilla of a 28-year-old female, is presented. Relevant literature is discussed.

Adult↗
PubMed1993

[Immunohistochemical determination of endometrial progesterone receptor (PR) content after intrauterine infusion of danazol in rabbits].

Danazol, an isoxazole derivative of 17 alpha-ethinyl-testosterone, has various effects on the female reproductive system. To examine its anti-estrogenic effects through the receptor system and clarify its direct effect on the endometrium in vivo, we applied danazol jelly into the rabbit uterine cavity. Recent studies performed in our laboratory using the ligand-binding assay have shown that danazol administered directly into the uterine cavity is absorbed by the endometrial tissue and exerts its anti-estrogenic effects possibly through progesterone receptors (PR) in the cells. In the present study we examined the variations in endometrial PR content during 7 days after the intrauterine administration of danazol into the rabbit uterine cavity. Immature female white rabbits were used. They were given daily subcutaneous injections of estradiol-17 beta (E2) for 3 days after which their abdomens were opened, and danazol gel was infused into the lumen of the right horn and HPC-jelly was infused into the lumen of the left horn, as the control. Thereafter and until they were killed, the same daily dose of E2 was injected. They were killed 6h, 24h, 3 days, 5 days or 7 days after intrauterine infusion of danazol and PRs were studied immunohistochemically using a specific antireceptor monoclonal antibody (PR-AT 4.14). Six hours after danazol infusion, the PR staining in the glandular epithelium and part of the stroma surrounding the epithelium had declined. On day 3, PR staining declined to its lowest level in the glandular epithelium and stroma. On Day 5, PR staining had been restored in the glandular epithelium but stayed low in the stroma.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Role of Lys-110 of human NADH-cytochrome b5 reductase in NADH binding as probed by site-directed mutagenesis.

Lys-110 of human NADH-cytochrome b5 reductase was replaced by Ala, Met, or Arg by site-directed mutagenesis to evaluate the role of the residue. Km values of purified Lys-110-->Ala and Lys-110-->Met mutants for NADH were approximately 200-fold and 1,100-fold higher than that of the wild-type, respectively, while the value of the Arg mutant was almost the same as that of the wild-type. These results indicate that the positive charge at position 110 is important for NADH binding. The kcat value of Lys-110-->Ala was not affected, indicating that the residue only participates in the binding process in the reaction by forming an ionic interaction with phosphoryl group of NADH.

Base Sequence↗
PubMed1993

Spontaneous rupture of splenic angiosarcoma: a case report of chemotherapeutic approach and review of the literature.

Angiosarcoma of the spleen is a rare disease, and the prognosis of this disease is extremely unfavorable. We herein review the case of a 45-year-old Japanese woman, who received a combined chemotherapy with cyclophosphamide, Adriamycin, vincristine, and prednisone after splenectomy and experienced a good response. The various types of chemotherapy for this disease are also discussed with references to the above case because no effective chemotherapeutic protocol for angiosarcomas has yet to be established.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Effect of 13-hydroperoxyoctadecadienoic acid on 15-hydroxy prostaglandin dehydrogenase activity in rabbit kidney cortex.

The effect of a hydroperoxy adduct of linoleic acid, 13-hydroperoxyoctadecadienoic acid (13-HPODE), on 15-hydroxy prostaglandin dehydrogenase activity in rabbit kidney cortex was examined. 13-HPODE inhibited the 15-hydroxy prostaglandin dehydrogenase activity at concentrations ranging from 1 to 10 microM. The effect was concentration-dependent and the concentration required for 50% inhibition was approximately 3 microM. Linoleic acid and 13-hydroxyoctadecadienoic acid (13-HODE) exhibited weaker inhibition of the enzyme activity than did 13-HPODE (linoleic acid, 30% inhibition at 10 microM; 13-HODE, 45% inhibition at 10 microM). Studies utilizing Fe2+ (a catalyst of peroxide decomposition), and mannitol or dimethylsulfoxide (a hydroxy radical scavenger) revealed that the inhibitory effect of 13-HPODE on the 15-hydroxy prostaglandin dehydrogenase activity is not due to the hydroxy radicals which are expected to be formed from 13-HPODE and that the hydroperoxy functional group is a prerequisite. The inhibition by 13-HPODE was uncompetitive and non-competitive with regard to NAD+ and prostaglandin E2, respectively. These results suggest that 13-HPODE has the potential to modulate the prostaglandin catabolism by affecting the 15-hydroxy prostaglandin dehydrogenase activity.

Animals↗
PubMed1993

Effects of reactive oxygen species on arachidonic acid metabolism in rabbit platelets.

Rabbit platelets were exposed to a reactive oxygen species (ROS) generating system (xanthine plus xanthine oxidase) to explore the effect of ROS on the formation of 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE), thromboxane (TX) B2, and 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) from exogenous arachidonic acid. Xanthine plus xanthine oxidase suppressed the production of 12-HETE, TXB2, and HHT by 65-69%. This effect was reversed by addition of catalase to the ROS generating system but not by superoxide dismutase, mannitol, or dimethylsulfoxide, indicating that H2O2 is the responsible metabolite. These results suggest that H2O2 plays an important role in the regulation of platelet cyclo-oxygenase and lipoxygenase activities.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1993

Pathogenesis of autoimmune hypothyroidism induced by lymphokine-activated killer (LAK) cell therapy: in vitro inhibition of human thyroid function by interleukin-2 in the presence of autologous intrathyroidal lymphocytes.

Lymphokine-activated killer (LAK) cell therapy frequently results in primary hypothyroidism. To elucidate the responsible mechanism, we investigated the effects of interleukin-2 (IL-2) on thyroid function of cultured human thyroid follicles in the presence or absence of autologous thyroid-derived lymphoid cells (TDLC). Human thyroid follicles, obtained by subtotal thyroidectomy from patients with Graves' disease, were cultured in serum-free medium containing bTSH and various concentrations of human IL-2, with or without TDLC. After 5 days of culture, 125I was added, and after an additional 3 days of culture, 125I incorporated into thyroid follicles and organic 125I (125I-T4 + 125I-T3) released into the culture medium were estimated. In the absence of TDLC, IL-2 did not affect bTSH-induced thyroid function. In the presence of TDLC, however, IL-2 inhibited the bTSH-stimulated thyroid function in a concentration-dependent manner. The minimum IL-2 concentration required to inhibit thyroid function was 1 U/ml. At 100 U/ml, IL-2 inhibited thyroid function completely. IL-2 increased the concentration of IFN-gamma in the culture medium conditioned by TDLC but not by thyroid follicles. When both were cocultured, IL-2 more significantly increased the concentration of IFN-gamma to an extent sufficient for inhibiting thyroid function per se. Furthermore, the addition of anti-IFN-gamma antibody to the medium partially restored the IL-2-inhibited thyroid function. In summary, by coculturing human thyroid follicles and autologous intrathyroidal lymphocytes with IL-2, it was possible to reproduce the thyroid dysfunction associated with LAK cell therapy. Our data indicate that IL-2 inhibits thyroid function, at least partly, by stimulating production of IFN-gamma, a potent inhibitory cytokine for thyroid cells.

Analysis of Variance↗