[New simple semiquantitative estimation of sulfosalcylic acid negative urinary proteins by phosphotungstic acid (author's transl)].
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Benzenesulfonates↗
Biomedical subjects
M Katoh
Publications and source records attributed to M Katoh.
Freon-TF freeze drying method for SEM sample.
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Animals↗
[Fine structure of mitotic melanocytes in the epidermis of C57 black mouse after UV irradiation (UV-A) (author's transl)].
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Animals↗
High resolution shadowing for electron microscopy by sputter deposition.
The sputtering process by an ion beam well collimated and highly accelerated provides a valuable means of high resolution shadowing, replication of a fine object by a combination of pre-shadowing and deposition as well as a preparation of supporting films. High resolution shadowing and films with grains smaller than 1 nm can be obtained by argon ion-sputtering targets of tungsten and tungsten/tantalum alloy. The resolution of carbon replicas pre-shadowed with tungsten/tantalum is determined from the radius of curvature of replicated magnesium oxide crystal corners.
Alloys↗
Inhibition of human cytochrome P450 enzymes by 1,4-dihydropyridine calcium antagonists: prediction of in vivo drug-drug interactions.
OBJECTIVE: 1,4-Dihydropyridine calcium antagonists such as nifedipine are potent vasodilators. It is now commonly agreed that the oxidation of 1,4-dihydropyridine into pyridine, which is one of the main metabolic pathways, is catalysed by the cytochrome P450 (CYP) 3A4 isoform. In the present study, the inhibitory effects of 13 kinds of 1,4-dihydropyridine calcium antagonists clinically used in Japan on human CYP-isoform-dependent reactions were investigated to predict the drug interactions using microsomes from human B-lymphoblast cells expressing CYP. RESULTS: The specific activities for human CYP isoforms included 7-ethoxyresorfin O-deethylation (CYP1A1), phenacetin O-deethylation (CYP1A2), coumarin 7-hydroxylation (CYP2A6), 7-benzyloxyresorufin O-dealkylation (CYP2B6), S-warfarin 7-hydroxylation (CYP2C9), S-mephenytoin 4'-hydroxylaion (CYP2C19), bufuralol 1'-hydroxylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), and testosterone 6beta-hydroxylation (CYP3A4). Benidipine and amlodipine competitively inhibited the CYP1A1 activity. Nifedipine, nisoldipine and aranidipine competitively inhibited the CYP1A2 activity. No 1,4-dihydropyridie calcium antagonists used in this study inhibited the CYP2A6 activity. Barnidipine and amlodipine inhibited the CYP2B6 activity. Nicardipine, benidipine, manidipine and barnidipine competitively inhibited the CYP2C9 and CYP2D6 activities. Inhibition extent of the CYP2E1 activity by nifedipine and aranidipine were weak. Nicardipine, benidipine and barnidipine inhibited the CYP2C19 and CYP3A4 activities. Among the human CYP isoforms investigated, the inhibitory effects of 1,4-dihydropyridine calcium antagonists were potent on human CYP1A2, CYP2B6, CYP2C9, CYP2C19 and CYP2D6 as well as CYP3A4. Furthermore, the isoform selectivity of inhibition by 1,4-dihydropyridine calcium antagonists was clarified. CONCLUSIONS: In consideration of the Ki values obtained in the in vitro inhibition study and the concentration of 1,4-dihydropyridine calcium antagonists in human liver, the possibility of in vivo drug interactions of nicardipine and other drugs which are mainly metabolised by CYP2C9 and/or CYP3A4 was suggested. The inhibition of human CYP isoforms by 1,4-dihydropyridine calcium antagonists except nicardipine might be clinically insignificant.
B-Lymphocytes↗
The characteristic binding of catechol estrogens to estrogen receptors in 7,12-dimethylbenz(a)anthracene-induced rat mammary tumors.
The binding of catechol estrogens (2-hydroxyestrone, 4-hydroxyestrone, 2-hydroxyestradiol, and 4-hydroxyestradiol) to estrogen receptors in 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumor cytosols was investigated. Cytosol estrogen receptors exhibited high affinities (Ka = 1.12-1.88 X 10(8) M-1) for all catechol estrogens as well as estradiol. The receptor level of catechol estrogens (46.1-97.5 fmol/mg protein) was 1.6-3.0 times higher than that of estradiol; especially the binding of 4-hydroxyestrone to estrogen receptors was the highest of all catechol estrogens and estradiol. In judging the receptor level of more than 20 fmol/mg protein to be positive, the binding of catechol estrogens to estrogen receptors was approximately correlated with that of estradiol. The positive receptor level of catechol estrogens was found in a half of tumor cytosols which showed the negative receptor level of estradiol. These results suggested that characteristic estrogen receptors indicating high affinities for catechol estrogens might be present in rat mammary tumor cytosols.
9,10-Dimethyl-1,2-benzanthracene↗
Establishment of a rapid bone resorption in vitro assay using previously frozen mouse unfractionated bone cells pretreated with parathyroid hormone.
We established a useful assay system for evaluating osteoclast-mediated bone resorption based on the use of unfractionated bone cells obtained from 10- to 11-day-old mice. When cells from 10 to 11 mice were treated for 7 days with rat parathyroid hormone (rPTH, 10(-8) M), a total of 4 to 5 x 10(7) cells could be obtained from the culture by treatment with 0.05% trypsin and 0.02% EDTA in PBS. These harvested cells contained about 20% tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells. When the harvested cells were cultured on dentine slices without rPTH, after 1 day, they formed TRAP-positive multinucleate cells that were active in bone resorption. Eel calcitonin (eCT) decreased the number of pits in a dose-dependent manner, and its half maximal inhibition dose (ID50) was 1.08 x 10(-11) M. Even after having been frozen in liquid nitrogen for 5 months, upon thawing, these cells were capable for forming pits; and this pit formation was inhibited by eCT. Since no appropriate osteoclastic cell line for evaluating bone resorption is available at present, this system can provide a useful, practical means for assaying osteoclastic bone-resorbing activity.
Acid Phosphatase↗
Pathologic characteristics of acute humoral rejection after ABO-incompatible kidney transplantation.
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ABO Blood-Group System↗
Behavioral and electroencephalographic studies of beagles with an Eck's fistula: suitability as a model of hepatic encephalopathy.
Behavioral manifestations, electroencephalograms (EEGs) and visually evoked potentials (VEPs) were studied in beagles with Eck's fistula (portacaval shunt [PCS]), an established model of hyperammonemia, to determine whether they developed CNS disorders characteristic of hepatic encephalopathy. After PCS, behavioral changes occurred in the form of listlessness, sluggishness (altered gait, snapping and transient catatonia-like symptoms) and apparent blindness, which appeared in that order and progressed to coma and death in some animals. The EEGs from the frontal cortex showed a gradual decrease in voltage and frequency. Development of snapping and catatonia-like symptoms coincided with the occurrence of high voltage fast waves in the EEGs from the occipital cortex. In comatose Eck's fistula dogs. flattening of the EEGs was recorded from the frontal cortex and a lowered voltage was noted in the EEGs from the occipital cortex. After PCS, the latencies and amplitudes of the components of VEP were increased. The snapping and catatonia-like symptoms were markedly ameliorated by carbamazepine and the coma by flumazenil and thyrotropin-releasing hormone. These findings indicate that Eck's fistula dogs provide a useful model of hepatic encephalopathy.
Ammonia↗
Comb-type polycations effectively stabilize DNA triplex.
DNA triplex formation has been studied as a potential strategy for regulation of gene expression. The triplex is, however, unstable under physiological conditions, so that an effective stabilizer for the triplex formation is needed. Here is shown a novel strategy to stabilize the triplex based on the molecular design of a comb-type polycation. Linear polycations, such as poly(L-lysine) and poly(L-arginine), thermally stabilize DNA duplexes (and triplexes). The complexes between DNA and the polycation are irreversible and are liable to precipitate out of aqueous media. The irreversibility and phase separating properties of the complex impede association of single-stranded (ss) DNAs in the complex to form duplexes and triplexes. A comb-type polycation consisting of a poly(L-lysine) backbone and grafted chains of hydrophilic polymers was prepared. The comb-type copolymers increased solubility of their complex with DNA and suppressed conformational changes of DNA. Thermal melting curve analyses revealed that the comb-type copolymer markedly stabilized DNA triplexes and did not disturb ssDNAs in forming duplexes and triplexes. Reversible and one-step melting/reassociation transitions of poly(dA).2poly(dT) triplex were shown in the pressure of the copolymers. The stabilizing effect of the copolymer was larger than that of spermine, a polyamine considered effective in stabilizing triplexes. These results indicated that molecular design of polycations with a comb-type structure is a novel strategy to create efficient triplex stabilizers. Such comb-type copolymer consisting of various types of polycation backbones and hydrophilic graft chains may have many applications in which specific and precise interactions of polynucleotides are involved.
Animals↗
Characterization of interpolyelectrolyte complexes between double-stranded DNA and polylysine comb-type copolymers having hydrophilic side chains.
The polyionic interaction between DNA and polycations grafted with hydrophilic dextran side chains was evaluated. The comb-type copolymers, poly(L-lysine)-graft-dextran, were successfully prepared by employing a reductive amination reaction between epsilon-amino groups of poly(L-lysine) (PLL) and the reductive ends of dextran (Dex). A coupling efficacy on the order of 70% was obtained regardless of intrinsic philicities of the solvents used, either aqueous buffer or DMSO. The resulting graft copolymers, which varied in the degree of grafting and the length of hydrophilic side chains, formed a soluble complex with DNA. They also affected the melting behavior of double-stranded DNA (dsDNA) in different ways. Copolymers having a high degree of grafting thermally stabilized dsDNA without affecting its reversible transition between single-stranded and double-stranded forms. However, copolymers with a low degree of grafting or with a high degree of grafting of short dextran chains impeded the reversibility of this transition. Furthermore, highly grafted copolymers also accelerated the hybridization of DNA strands in a low-ionic strength medium. It is of particular note that these copolymers scarcely altered circular dichroismic signals of dsDNA even when the copolymers were added in excess. This suggested that the copolymer interacted with dsDNA without affecting its native structure or physicochemical properties. Finally, the copolymer even formed a stable complex with a short oligonucleotide (20 bases). We, therefore, concluded that, by regulating the degree of grafting and the molecular weight of grafted side chains, it would be possible to design novel different graft copolymers capable of acting as carriers of functional genes to target cells or tissue.
Animals↗
Induction of lymphokine-activated killer and natural killer cell activities from cryopreserved lymphocytes.
Lymphokine-activated killer (LAK) and natural killer (NK) cells were studied for their capacity to retain cytotoxicity after cryopreservation. LAK cells were generated by a 4-day culture of lymphocytes with recombinant interleukin-2 (rIL-2). Cytotoxicity was measured by 51Cr-release assay at effector:target ratios of 10:1 to 80:1. Cryopreserved LAK cells retained 58.8 to 87.4 percent of cytotoxicity, as compared with that in fresh control cells. Cryopreserved NK cell activity against K562 and Molt-4 targets was 45.7 to 67.9 percent of the respective values of the fresh control cells. The responsiveness of NK cells to polyinosinic-polycytidilic acid (poly I:C), interferon-alpha (IFN-alpha), or rIL-2 remained intact. Activated NK cell activity after poly I:C or IFN-alpha stimulation and that after rIL-2 were, respectively, comparable to and higher than the endogenous NK cell activity of the fresh cells. The composition of lymphocyte subsets as determined by flow cytometry using monoclonal antibodies did not change after cryopreservation, indicating that cellular loss of the given subsets did not occur during the procedure. The retention of substantial levels of cytotoxicity in cryopreserved LAK and NK cells may make them promising candidates as cytotoxic effector cells.
Antibodies, Monoclonal↗
Long-term results following different extent of resection in chronic pancreatitis.
BACKGROUND/AIMS: To evaluate, whether the indication related varying extent of resection in chronic pancreatitis has a predictable impact on long-term outcome. METHODOLOGY: One hundred and twenty-six patients consecutively underwent surgery for chronic pancreatitis from March 1987 to September 1997. Three treatment categories were defined: Pancreatoduodenectomy, duodenum-preserving resection and drainage procedures, and left-sided pancreatectomy. Main outcome measures were late mortality, pain scores preoperatively and at follow-up, body-weight change, percentage of insulin dependent diabetes, patient's and physician's satisfaction with surgery. RESULTS: Forty-one patients underwent pancreatoduodenectomy, 59 drainage procedures, and 26 left-sided pancreatectomy, respectively. Hospital mortality was 1 (2.4%), 4 (6.8%), and 1 (3.8%) (P = NS), totaling 4.8%. After an average follow-up of 5.2 years, late mortality was 10 (24.4%), 9 (15.3%), and 4 (15.4%) (P = NS) for a total of 23 (18.3%). Two patients (1.6%) died of unsuspected pancreatic cancer. Three patients (2.4%) had to be reoperated upon for pain relapse. The mean pain score was 8.8 preoperatively and 2.1 at late follow-up and not different among groups. Body-weight gain averaged 3.0, 4.0, and 3.4 kg, with no significant differences. Percentage of insulin dependency in all patients rose from 14% prior to surgery to 30% at reevaluation, and was very similar in all treatment categories. CONCLUSIONS: The different kind and level of invasiveness of the surgical procedures did not significantly influence the late outcome. High rates of late mortality and deterioration of endocrine function are to a greater extent sequelae of comorbidity and the progression of the underlying pancreatic disease.
Adult↗
Micronucleus tests on N-ethyl-N-nitrosourea with mouse peripheral blood reticulocytes using acridine orange-coated slides.
The micronucleus test with peripheral blood using acridine orange-coated slides was validated in male CD-1 mice treated once with N-ethyl-N-nitrosourea (ENU) at doses of 6.25, 12.5, 25.0, and 50.0 mg/kg body weight. Peripheral blood preparations were made 0, 24, 48, and 72 h after treatment. The frequencies of micronucleated peripheral reticulocytes in the ENU-treated groups increased dose-dependently, peaking at 48 h after treatment. The results indicate that the method used in the present study can be an alternative to the method using bone marrow polychromatic erythrocytes.
Acridine Orange↗
Correlation of circulating tumor cells with tumor size and metastatic load in a spontaneous lung metastasis model.
BACKGROUND: The prognostic value of circulating tumor cells remains unclear since, in principle, most tumor cells are unable to survive in the bloodstream. The aim of the study was to establish a system that can be used to investigate the metastatic process in more detail, with emphasis on circulating tumor cells. MATERIALS AND METHODS: Human colon carcinoma cells (HT29) were transplanted into severe-combined-immunodeficient (scid) mice. The metastatic load in the blood was investigated using the human-specific carcinoembryonic antigen (CEA) as target for quantitative polymerase-chain-reaction (PCR). RESULTS: A close correlation between the weight of the primary tumor and the number of circulating tumor cells was detected (r=0.7240; p<0.0001). Moreover, the number of circulating tumor cells and the actual number of spontaneous lung metastases was related (r=0.8283; p<0.0001). CONCLUSION: A tumor xenotransplantation model is presented that allows for a detailed investigation of the metastatic process in three different compartments: the primary tumor bed, the bloodstream and the target organ of metastatic residency.
Animals↗
Expression of MAGE-1, MAGE-2 and MAGE-3 genes in human gastric carcinomas; lack of evidence for cytotoxic effects in cases with simultaneous expression of MAGE-3 and HLA-A2.
The human MAGE gene products are recognized by major histocompatibility complex-restricted cytotoxic T lymphocytes. We analyzed by RT-PCR the expression of MAGE-1, MAGE-2, MAGE-3 and HLA-A2 genes in 10 human gastric cancer cell lines and 46 human stomachs removed due to advanced gastric carcinomas. All the cell lines expressed MAGE genes, except for MKN-45 and -74 which lacked the expression of MAGE-1 and -3 genes in this study. Of the 46 gastric carcinomas, MAGE-1, -2 and -3 genes were expressed in 14 (30%), 10 (22%) and 26 (57%) cases, respectively, regardless of histological type. Normal gastric mucosa and intestinal metaplastic mucosa showed no expression of these genes. HLA-A2 gene expression was noted in 14 both normal and carcinoma cases. Simultaneous expression of MAGE-3 and HLA-A2 genes was noted in 7 cases. Mean apoptotic and Ki-67-labeling indices (AI and KI) of carcinoma cells were 2.3 +/- 0.5 and 48.1 +/- 6.0 in 7 cases, and 2.8 +/- 0.2 and 47.3 +/- 2.7 in the other 39 cases lacking the expression of MAGE-3 and/or HLA-A2 genes, respectively. The two-year survival rate did not differ between the two groups. Although this study confirmed the relatively higher expression of the MAGE gene family in human advanced gastric carcinomas, it might suggest that simultaneous expression of MAGE-3 and HLA-A2 genes does not necessarily imply the induction of cancer cell apoptosis by CTL.
Antigens, Neoplasm↗