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Biomedical subjects

M Katagiri

Publications and source records attributed to M Katagiri.

At least 37 records · Page 2Linked to original sources
PubMed2000

Successful treatment of IBL-like T-cell lymphoma with cyclosporin A: two case reports with special reference to serum cytokine levels.

The prognosis of immunoblastic lymphadenopathy (IBL)-like T-cell lymphoma is grave, and its effective treatments have not been established. We applied oral cyclosporin A (CsA) treatment to two cases of IBL-like T-cell lymphoma, and succeeded in achieving complete remissions. CsA is known to have a suppressive effect on the immune system, most notably T-cells, but it also has a direct cytotoxic/apoptosis-inducing effect on lymphocytes. Its combined effects on neoplastic T-cells might have played an important role in achieving remission. In both cases, serum levels of interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-alpha) were elevated and decreased or returned to normal after achieving remissions. Considering that both cytokines represent monokines, it seems that a macrophage system is also involved in the pathogenesis of this disorder. Our two cases indicate that administration of CsA may be an effective therapy for IBL-like T-cell lymphoma.

Administration, Oral↗
PubMed1999

Neuronal differentiation of neuro 2a cells by inhibitors of cell cycle progression, trichostatin A and butyrolactone I.

Trichostatin A (TSA, 17 nM), a specific and reversible inhibitor of histone deacetylase induced neurite network formation at and after 4 days. The networks were preserved for at least 3 weeks in the presence of TSA. Butyrolactone I (BLI, 23.6 microM), an inhibitor of cdc2 and cdk2 kinases, also induced neurite extension. Both compounds enhanced the acetylcholinesterase activity of the cells. Cell cycle progression of the cells was blocked by TSA (17 nM) at G1 phase alone. Furthermore, the level of histone hyperacetylation and p21(WAF1) expression in TSA-treated cells increased transiently. These findings suggest that the induction of the neuronal differentiation in Neuro 2a cells by these agents requires the cell cycle arrest at G1 phase, which is caused by inhibition of cycline dependent kinase, a target molecule of BLI and p21(WAF1).

4-Butyrolactone↗
PubMed1999

Autoradiographic evaluation of 99mTc-methylene diphosphonate accumulation in oral cancer invading the mandible.

PURPOSE: Skeletal scintigraphy, a sensitive diagnostic tool used to detect changes in bone, is helpful for evaluating bone invasion by oral cancer. However, the exact sites of accumulation of 99mTc-phosphate compounds in the mandible have not yet been fully elucidated. The aim of this study was to determine the localization of 99mTc-methylene diphosphonate (MDP) in the areas of mandible that have been invaded by cancer. PATIENTS AND METHODS: Seven patients with oral cancer (lower gingiva, 4; tongue, 2; floor of the mouth, 1) who underwent surgical treatment with mandibular bone resection were included in the study. Autoradiography and contact macroradiography were used for evaluation of 99mTc-MDP accumulation. RESULTS: Radioactivity reflecting accumulation of 99mTc-MDP was documented encircling the portion of the mandible with cancerous invasion, suggesting that 99mTc-MDP accumulated in immature bone. High uptake also was found in the periosteal reactive bone around the cortical bone. CONCLUSIONS: The amount of increased 99mTc-MDP circumscribing carcinoma invasion varies among cases. Additionally, uptake may not correspond directly with the amount of the carcinoma invasion; that seen in periosteal bone could be attributed mistakenly to bone invasion in planar scintigraphy.

Aged↗
PubMed1999

Contribution of human hepatic cytochrome P450s and steroidogenic CYP17 to the N-demethylation of aminopyrine.

1. Aminopyrine N-demethylase activity was determined for 11 forms of human hepatic cytochrome P450s (P450s) expressed in yeast Saccharomyces cerevisiae and for human steroidogenic CYP17 expressed in Escherichia coli. 2. Among the hepatic P450s, the N-demethylation of aminopyrine was catalysed most efficiently by CYP2C19, followed by CYP2C8, 2D6, 2C18 and 1A2, whereas the activity with CYP2E1 was negligible. The kinetics of the N-demethylation process by CYP1A2, 2C8, 2C19 and 2D6 were studied by fitting to Michaelis-Menten kinetics by Lineweaver-Burk plots. CYP2C19 exhibited the highest affinity and a high capacity for the aminopyrine N-demethylation. CYP2C8 showed the highest Vmax, followed by CYP2C19, 2D6 and 1A2, whereas the Km for CYP2C8, 2D6 and 1A2 were 10-17 times higher than that for CYP2C19. Accordingly, the Vmax/Km for CYP2C19 was more than nine times higher than that of other P450s. 3. Human steroidogenic CYP17 also catalysed aminopyrine N-demethylation and the activity was comparable with that for CYP3A4 which is a dominant P450 in human liver. The activity was increased 1.5-fold by the addition of cytochrome b5, whereas the activity was not affected by the addition of Mg2+. 4. These results suggest that several human hepatic P450s, especially CYP2C19, and steroidogenic CYP17 exhibit aminopyrine N-demethylase activity.

Aminopyrine↗
PubMed1999

Postinspiratory activity of costal and crural diaphragm.

Because the first stage of expiration or "postinspiration" is an active neurorespiratory event, we expect some persistence of diaphragm electromyogram (EMG) after the cessation of inspiratory airflow, as postinspiratory inspiratory activity (PIIA). The costal and crural segments of the mammalian diaphragm have different mechanical and proprioceptive characteristics, so postinspiratory activity of these two portions may be different. In six canines, we implanted chronically EMG electrodes and sonomicrometer transducers and then sampled EMG activity and length of costal and crural diaphragm segments at 4 kHz, 10.2 days after implantation during wakeful, resting breathing. Costal and crural EMG were reviewed on-screen, and duration of PIIA was calculated for each breath. Crural PIIA was present in nearly every breath, with mean duration 16% of expiratory time, compared with costal PIIA with duration -2. 6% of expiratory time (P < 0.002). A linear regression model of crural centroid frequency vs. length, which was computed during the active shortening of inspiration, did not accurately predict crural EMG centroid frequency values at equivalent length during the controlled relaxation of postinspiration. This difference in activation of crural diaphragm in inspiration and postinspiration is consistent with a different pattern of motor unit recruitment during PIIA.

Animals↗
PubMed1999

Effects of methanol and temperature on enzyme immunoassay with monoclonal antibodies specific to the insecticide etofenprox.

We examined the effects of methanol and temperature on the reactivity of monoclonal antibodies specific to the insecticide etofenprox. When the antigen-antibody reaction was done at 4 degrees C in 10% methanol, the sensitivity in the enzyme immunoassay with each antibody was more than 10-fold higher than that measured at 37 degrees C. Although in 10% methanol one of the antibodies reacted equally with both etofenprox and the carbonate-derivative of etofenprox, in 50% methanol the antibody reacted with etofenprox, but not with the derivative.

Antibodies, Monoclonal↗
PubMed1999

Successful treatment of immunoblastic lymphadenopathy-like T-cell lymphoma with cyclosporin A.

Immunoblastic lymphadenopathy (IBL)-like T-cell lymphoma is considered to belong to peripheral T-cell lymphoma. Its prognosis is grave and effective treatments have not been established. Recently, we gave oral cyclosporin A (CsA) to a patient with IBL-like T-cell lymphoma, and succeeded in achieving dramatic remission. In this case, serum levels of interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF alpha) were elevated and decreased or returned to normal after achieving remission. Since CsA is a potent suppressor of the immune system and most notably T-cells, the immunosuppression of T-cell function might have played an important role in achieving remission in this case, although the precise mechanism still remains to be elucidated. The present case indicates that administration of CsA may be a very effective and safe selection of therapy for IBL-like T-cell lymphoma, as well as analogous disorders such as IBL and angioimmunoblastic lymphadenopathy with dysproteinemia (AILD), thereby will contribute to improving the prognosis of patients with these diseases.

Administration, Oral↗
PubMed1999

[Electromyographic activity of neck muscles during the production of inspiratory pressure].

The differential inspiratory EMG activities of the scalene (SCLN), sternocleidomastoid (STERNO), and trapezius (TRAPEZ) muscles were studied in 6 awake and healthy men (mean age, 22 years; and mean weight, 62.4 kg). Pairs of fine wire EMG electrodes were inserted into each of these muscles using a guide needle and high-resolution ultrasonography. With subjects on a mouthpiece, inspiratory effort against an occluded airway was recorded at end expiratory position in the standing position. Mouth pressure and integrated EMG signals were sampled to a computer during the gradual production of maximal static inspiratory pressure (PImax) over 10 s. Maximum EMG activity (EMGmax) was obtained for each muscle during specific respiratory and postural maneuvers. Mouth pressures and integrated EMG activities were expressed as percentages of PImax and EMGmax, respectively. As mouth pressure increased, SCLN, then STERNO, and finally TRAPEZ EMGs were sequentially activated in 5 subjects. In one subject, STERNO preceded SCLN EMG activation. Group mean (+/- SE) mouth pressures at the onset of SCLN, STERNO, and TRAPEZ EMG were 10.3 +/- 5.8% PImax. 30.8 +/- 8.2% PImax, and 79.3 +/- 9.6% PImax, respectively. TRAPEZ mouth pressures differed from SCLN and STERNO values (p < 0.05). At 90% PImax, group mean (+/- SE) SCLN, STERNO, and TRAPEZ EMG activity reached 69.7 +/- 9.0% EMGmax, 51.5 +/- 11.1% EMGmax, and 5.1 +/- 2.4% EMGmax, respectively. TRAPEZ EMG at 90% PImax differed from both SCLN and STERNO values (p < 0.05). These results suggest that SCLN has strong, STERNO intermediate, and TRAPEZ weak, inspiratory activities.

Adult↗
PubMed1999

[Adenosine deaminase activity in bronchoalveolar lavage fluid of sarcoidosis patients].

We studied adenosine deaminase (ADA) activity in bronchoalveolar lavage fluid (BALF) specimens from 24 patients with sarcoidosis. Mean BALF-ADA activity was significantly (p < 0.0001) elevated in patients with sarcoidosis (1.02 +/- 1.01 IU/L, mean +/- SD) compared to the subjects in a healthy control group (0.08 +/- 0.29 IU/L). In the sarcoidosis patients with high BALF-ADA activity (> or = 1.0 IU/L), AaDO2 was significantly (p < 0.0001) elevated compared to its level in patients with normal BALF-ADA activity (< 1.0 IU/L). BALF-ADA activity was significantly (p < 0.01) higher in patients who exhibited lung-field accumulations on 67Ga scintigrams compared to those with no accumulations, and significantly (p < 0.001) higher in patients undergoing corticosteroid treatment compared to in those patients who did not receive such treatment. These findings were similar to the results of studies using data on BALF-ADA/albumin ratios. Furthermore, they suggest that the localized production of ADA may increase in sarcoidosis patients displaying 67Ga scintigram lung-field accumulations with increased AaDO2, and that BALF-ADA activity may be a useful indicator of disease activity and the need for treatment.

Adenosine Deaminase↗
PubMed1999

[Usefulness of 67Ga scintigraphy in deciding surgical indication in secondary hyperparathyroidism].

In order to evaluate the usefulness in deciding surgical indication in secondary hyperparathyroidism (SHP), 67Ga scintigraphy was performed in 37 patients of SHP before parathyroidectomy (PTx). The radionuclide accumulation in skull and submandible was classified into 4 patterns (skull-submandibular pattern, skull pattern, submandibular pattern and normal pattern). Serum alkaline phosphatase levels were significantly elevated in patients of skull-submandibular pattern (13 cases) compared with skull pattern (6 cases), submandibular pattern (6 cases) and normal pattern (12 cases). Serum intact parathyroid hormone levels were significantly elevated in patients of skull-submandibular and skull patterns compared with normal pattern. No significant difference was observed among the weight of resected parathyroid glands. In 4 of 6 patients of normal pattern on 67Ga scintigram, bone scintigraphy showed a characteristic pattern of SHP including an increased accumulation in the skull and submandible. Bone mineral density (BMD) in the distal radius was increased within six to twelve months after PTx in 10 of 11 patients of skull-submandibular pattern on 67Ga scintigram, whereas only one patient showed an increase in BMD in 9 patients of normal pattern. In summary, it was concluded that 67Ga scintigraphy could provide a useful information in deciding the indication for PTx in secondary hyperparathyroidism.

Citrates↗
PubMed1999

Eradication of Helicobacter pylori using 30 mg or 60 mg lansoprazole combined with amoxicillin and metronidazole: one and two weeks of a new triple therapy.

A new triple therapy using a proton pump inhibitor and two antibiotics shows high efficiency against Helicobacter pylori infection. The aim of this study was to determine the optimal dose and duration of lansoprazole (LA) administration in combination with amoxicillin (AMPC) and metronidazole (MNZ). A total of 91 patients were enrolled in this study. They were divided into four groups: group A, 2 weeks of 30mg LA once daily, 500mg AMPC tid, and 250mg MNZ tid; group B, 2 weeks of 30mg LA bid, 500mg AMPC tid, and 250mg MNZ tid; group C, 1 week of 30mg LA once daily, 500mg AMPC tid, and 250mg MNZ tid; group D, 1 week of 30mg LA bid, 500mg AMPC tid, and 250mg MNZ tid. H. pylori status was determined by the rapid urease test, culture, histology, and 13C-urea breath test before and at least 4 weeks after the end of therapy. The cure rates in a per-protocol analysis and the incidence of adverse events in the evaluated patients were, respectively, 89.5% and 21.1% in group A, 100% and 20.0% in group B, 96.8% and 12.9% in group C, and 92.3% and 26.9% in group D. Most of the adverse events were tolerated. All four regimens in this study showed the same cure rates, and they were effective and well tolerated. One week of triple therapy using once-daily administration of 30mg LA is a good alternative.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

The metabolic pathway of visual pigment chromophore formation in Drosophila melanogaster--all-trans (3S)-3-hydroxyretinal is formed from all-trans retinal via (3R)-3-hydroxyretinal in the dark.

Carotenoid-depleted fruit flies, Drosophila melanogaster, were reared on yeast/glucose medium containing lipid-depleted white corn grits and cholesterol. After rearing for more than a year, the yield of flies remained constant and the content of 3-hydroxyretinal in a head was three logarithmic units less than that of normal flies reared on medium containing yellow corn grits. When all-trans retinal was supplied as the sole source of retinoids, the flies formed and accumulated all-trans 3-hydroxyretinal in the dark. To examine the metabolic pathway to produce (3S)-3-hydroxyretinal in Drosophila, all-trans retinal was supplemented for two hours to carotenoid-depleted flies in the dark, and the subsequent changes in the composition of 3-hydroxyretinal enantiomers were analyzed using a chiral column on HPLC. The results indicated initial formation of (3R)-3-hydroxyretinal followed by isomerization into the 3S enantiomer. In another set of experiments, the membrane fraction was obtained from the head homogenate of retinoid-depleted flies and an in vitro assay of 3-hydroxyretinal formation from retinal was performed. The 3-hydroxyretinal produced was the 3R enantiomer, supporting the result obtained from the in vivo experiment whereby (3S)-3-hydroxyretinal is produced from retinal via (3R)-3-hydroxyretinal. Addition of NADPH enhanced 3-hydroxyretinal formation and the presence of carbon monoxide inhibited it, suggesting that hydroxylation at the C3 position of retinal occurred via the monooxygenase activity of cytochrome P-450.

Animals↗
PubMed1998

CD4+ T cells from peripheral blood of a melanoma patient recognize peptides derived from nonmutated tyrosinase.

Tyrosinase is an antigen that is expressed by normal melanocytes as well as melanoma cells, against which responses by autologous T cells have been detected. Although CD4+ T cells play an important role in tumor immunity in animal tumor models, little information about CD4+ T-cell immunity against human tumors exists. Here, we report that CD4+ T cells from the peripheral blood of a patient with melanoma respond to synthetic peptides derived from nonmutated tyrosinase. T-cell clones were generated that recognized the tyrosinase p386-406 peptide when it was presented by the HLA-DR15 (DRB1*1501) molecule. The CD4+ T-cell clone also recognized autologous EBV-transformed B-lymphoblastoid cell lines that had been pulsed with the lysate of melanoma cells. The synthetic tyrosinase p386-406 peptide was capable of binding to HLA-DR15 (DRB1*1501) molecules on cell surface of DR15 homozygous cells. Thus, the finding that nonmutated tyrosinase peptides are immunogenic in a melanoma patient may provide the basis for the development of cancer immunotherapy, based on knowledge of synthetic tumor-associated peptide antigens.

Antigen-Presenting Cells↗
PubMed1998

A study of sternocleidomastoid muscular atrophy after modified neck dissection.

To elucidate the conditions of atrophy in the sternocleidomastoid muscle (SCM) after modified neck dissection (MND), we tried to scrutinize the atrophic regions in the SCM and determine the cause of atrophy, by electromyography in 40 patients with SCM atrophy following MND. We also examined the detailed anatomy of the SCM in 40 cadavers. Atrophy was observed in the caudal portion in the SCM in 90% of the patients. Electromyographic examination revealed neurogenic atrophy in 24 patients, ischemic atrophy in 11, and a mixing of both types in 5. The SCM was found to be innervated by the spinal accessory nerve (SAN) and the SCM branch of the cervical nerve. The main artery feeding the cranial half of the SCM was a branch of the occipital artery (Oc) or the external carotid artery (Ex), and the auxiliary artery was a branch of the posterior auricular artery (Ap). The main artery feeding the caudal half of the SCM was a branch of the superior thyroidal artery (St), and the auxiliary artery was a branch of the subclavian artery (Sc). Postoperative SCM atrophy is attributed to damage of the feeding artery in the SCM caudal portion and local damage in the nerve fibers running through the SCM. To prevent this type of atrophy, it is important to carefully handle this muscle itself and protect the nerve fibers running through it, as well as to conserve the SCM branches of the St and Sc.

Aged↗
PubMed1998

Tyrosinase epitope recognized by an HLA-DR-restricted T-cell line from a Vogt-Koyanagi-Harada disease patient.

Human T-cell-mediated autoimmune diseases are often genetically linked to particular alleles of HLA class II genes. Vogt-Koyanagi-Harada's (VKH) disease, which is regarded as an autoimmune disorder in multiple organs containing melanocytes, has been found to be associated with HLA-DR4 (DRB1(*)0405) and HLA-DR53 (DRB4(*)0101). Tyrosinase is a melanoma antigen (Ag) expressed by normal melanocytes as well as melanoma cells against which responses by autologous T cells have been detected. We established a T-cell line from the peripheral blood of a patient with VKH disease which responded to synthetic peptides corresponding to tyrosinase. The T-cell line was generated which recognized the tyrosinase p188 - 208 peptide when presented by the HLA-DR4 (DRB1(*)0405) molecule on the surface of HLA class II-expressing L-cell transfectants. The minimal antigenic peptide which induced T-cell responses was an 11-amino-acid sequence and located at tyrosinase p193 - 203 (E-I-W-R-D-I-D-F-A-H-E). This peptide contained the DRB1(*)0405-binding peptide motif (hydrophobic residues (Y, F, W) at position 1 as an anchor residue, and negatively charged residues (D, E) at position 9), which corresponded to the W at p195 and the D at p203. These observations demonstrate that tyrosinase peptides are immunogenic, and may be a candidate for an autoantigen in VKH disease, suggesting that probing the T-cell responses against synthetic peptides is a productive approach for identifying the autoantigenic peptides associated with autoimmune diseases including VKH disease.

Amino Acid Sequence↗
PubMed1998

Evidence that immature rat liver is capable of participating in steroidogenesis by expressing 17alpha-hydroxylase/17,20-lyase P450c17.

Steroid hydroxylase cytochrome P450c17 has been previously purified from microsomal fractions of immature rat livers. In this study, we investigated the expression of P450c17 in rat livers to understand a role of steroidogenesis in the extrasteroidogenic tissue. Upon immunoblot analysis utilizing liver microsomes from rats, P450c17 was detected in 1 and 3 week old rats but not in adult rats. Data from immunohistochemical studies also showed a similar age-dependent expression of P450c17 and indicated that P450c17 detected in immature rat livers is localized in cells surrounding interlobular veins. This age-dependent expression of P450c17 in rat livers was observed in both sexes. Upon enzymatic analysis utilizing microsomal fractions from livers, levels of 17alpha-hydroxylase and 17,20-lyase activity for pregnenolone and progesterone increased by 3 weeks and dramatically reduced at 7 weeks, which is consistent with the expression level of P450c17. These data clearly indicate that P450c17 is expressed in immature rat liver to produce 17alpha-hydroxysteroids and C19-steroids. Based upon immunoblot analysis, the expression level of P450c17 in immature rat livers was approximately one third of that in testis. Compared expression level of P450c17 and total volume of organs between liver and testis, the total amount of steroid metabolites produced by liver P450c17 could be greater than that produced by gonadal P450c17. Because of the absence of P450c17 in rat adrenal glands, rat liver could be the major site for producing 17alpha-hydroxysteroids and C19-steroids in this particular period of life. Although physiological products formed by P450c17 in liver and their roles remain to be elucidated, this study suggests a large capacity of prepubertal rat liver for participating the production of steroid hormones and a putative importance of 17alpha-hydroxysteroids and C19-steroids, such as cortisol and androstendione, which are generally believed to be minor components of steroid hormones in rodents.

Animals↗
PubMed1998

Contribution of human hepatic cytochrome P450 isoforms to regioselective hydroxylation of steroid hormones.

1. Hydroxylation activities toward steroid hormones were determined for eleven forms of human hepatic cytochrome P450s expressed in yeast Saccharomyces cerevisiae cells. Microsomes were prepared from the yeast cells and assayed for their regioselectivity of hydroxylation toward progesterone, pregnenolone, dehydroepiandrosterone (DHEA) and oestrone. 2. 6 beta-Hydroxylation of progesterone was catalysed most efficiently by CYP3A4, followed by CYP2D6. CYP3A4 showed the highest progesterone 16 alpha-hydroxylation activity, followed by CYP1A1 and CYP2D6. 16 alpha-Hydroxylation of pregnenolone was catalysed efficiently by CYP1A1 and CYP3A4. Only CYP3A4 exhibited 16 alpha-hydroxylase activities toward DHEA and oestrone. 3. Addition of nifedipine, a typical substrate of CYP3A4, inhibited the 6 beta- and 16 alpha-hydroxylation of progesterone by CYP3A4. 4. These results suggest that CYP3A4 and CYP1A1 are responsible for the hydroxylation of these endogenous steroids, as well as xenobiotics, in human liver.

Aryl Hydrocarbon Hydroxylases↗