PubMed Health⌕ Search

Biomedical subjects

M Kaneda

Publications and source records attributed to M Kaneda.

At least 91 records · Page 5Linked to original sources
PubMed1994

Protective effects of sulfhydryl compounds on HOCl-induced intracellular Ca2+ increase in single rat ventricular myocytes.

Effects of sulfhydryl compounds on cell injuries caused by hypochlorous acid (HOCl) were studied in isolated rat cardiomyocytes by way of continuous measurement of intracellular Ca2+ using calcium sensitive fluorescent dye, fura-2. Ten minutes exposure of the cell to 100 microM HOCl induced a significant increase in the intracellular free calcium concentration ([Ca2+]i) from 90 +/- 20 nM to 266 +/- 74 nM (n = 44, mean +/- S.D.). This increase in [Ca2+]i was reversed by subsequent application of dithiothreitol (DTT) in a dose dependent manner; 30 microM DTT was found effective, while 2 mM DTT almost completely restored the [Ca2+]i to the control level. Similar to DTT, cysteine ethyl ester and cysteine methyl ester could also reverse the HOCl-induced rise of [Ca2+]i where the order of the potency was DTT > cysteine ethyl ester > cysteine methyl ester. In contrast, increase in [Ca2+]i induced by HOCl was not recovered by application of other sulfhydryl compounds such as cysteine and glutathione. Since HOCl administrated in the presence of cysteine failed to induce an increase in [Ca2+]i, we conclude that membrane permeable sulfhydryl compounds may reverse the increase in [Ca2+]i caused by HOCl.

Animals↗
PubMed1994

Purification and properties of a protease from the sarcocarp of bead tree fruit.

A protease was purified from bead tree fruit (Melia azedarach L. var. japonica Makino) in four steps, including HPLC gel-filtration. The M(r) of the enzyme, named melain, was estimated to be 25,000 on SDS-PAGE and on HPLC gel filtration. Melain contained a carbohydrate moiety. Using casein as a substrate, the optimum pH of the enzyme was 7.5-8.5 at 37 degrees. The enzyme was inhibited by iodoacetic acid, but was not inhibited by phenylmethanesulphonyl fluoride or EDTA. The enzyme had a wide specificity for peptide substrates such as oxidized insulin B-chain. All split sites (P1 and/or P'1) were hydrophobic or charged amino acid residues. The enzymatic properties of this protease were similar to those of phytolacain, an enzyme from the fruit of pokeweed, Phytolacca americana.

Amino Acid Sequence↗
PubMed1994

Protease from the sarcocarp of Trichosanthes bracteata.

A protease has been purified from sarcocarp of Trichosanthes bracteata (Lam.) Voigt by four steps of chromatography. Its M(r) was estimated by SDS-PAGE to be ca 67,000. The optimum pH of the enzyme was 11 at 35 degrees using casein substrate. The enzyme was strongly inhibited by di-isopropyl fluorophosphate, but not by EDTA and cysteine protease inhibitors. The oxidized insulin B-chain was cleaved at the peptide bonds of Cys7 (SO3H)-Gly8, Glu13-Ala14, Try16-Leu17 by the enzyme for 1 min. The results indicated that the T. bracteata protease is serine protease, similar to cucumisin from the sarcocarp of melon fruit (Cucumis melo L. var. Prince).

Amino Acid Sequence↗
PubMed1994

Activation of chloride current by P2-purinoceptors in rat ventricular myocytes.

1. Rat ventricular myocytes were dissociated and their responses to extracellularly applied ATP were recorded using patch pipettes under the whole cell configuration. 2. ATP initially induced an inward current followed by an outward current at -50 mV. With a Cs-rich pipette solution the late outward current was blocked, leaving a sustained inward current (IATPs) suggesting that a K+ conductance underlies the late response. 3. When the extracellular Cl- concentration was changed, the reversal potential of IATPs corresponded well to the shift of the Cl- equilibrium potential. IATPs was reversibly blocked by the chloride channel blocker, 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS). 4. The concentration-response curve of IATPs had a Hill coefficient of 0.98 and an EC50 value of 5.2 x 10(-6) M. 5. ATP was more potent than ADP, while AMP and adenosine were ineffective, suggesting that P2-purinoceptor activation induced IATPs. 6. The activation of IATPs was depressed by depleting the extracellular Mg2+ and increased by adding Mg2+. 7. Our results strongly suggest that P2-purinoceptor activation by ATP induces both a Cl(-)-conductance (IATPs) and a K(+)-conductance in rat ventricular myocytes.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1994

Characterization of a Protease from a Psychrotroph, Pseudomonas fluorescens 114.

A psychrotrophic bacterium isolated from river sediment was identified as Pseudomonas fluorescens 114. It grew at 0 degrees C and optimally at 20 degrees C. The bacterium produced a protease with a molecular weight of 47,000, which was stable in the pH range of 5 to 9 and worked optimally between pH 6.5 and 10. Activity was optimal at 35 degrees C and was lost immediately at 50 degrees C and after 5 min at 45 degrees C. At 0, 10, and 20 degrees C, 24, 38, and 57% of optimal activity were observed, respectively.

Journal Article↗
PubMed1994

[A case of lung cancer avoidable right pneumonectomy due to external and intraluminal irradiation therapy].

A 54-year-old man with squamous cell carcinoma of the lung resected after external and high dose rate intraluminal irradiation (HDRII) therapy is reported. Cancer existed in right lower bronchus, extended to bifurcation of upper broncus and truncus intermedius. The patient received external irradiation of 40 Gy and HDRII of 18 Gy (Iridium192 was used) simultaneously. Effectiveness of irradiation was remarkable, tumor disappeared in chest CT and bronchoscopy. Middle and lower lobectomy and bronchial wedge resection was performed. Histologically, cancer was not existed in second carinal portion, so curative resection was done. The result suggests that HDRII is effective therapy as preoperative adjuvant irradiation.

Brachytherapy↗
PubMed1994

Reduced fertility in females of the hereditary polydactyly rat.

The present studies assessed reproductive capacity of hereditary polydactyly(pd/pd) female rats that had genetically caused polydactyly in both fore- and hindlimbs. During an 8- or 10-day period of vaginal estrous cycle observation, persistent estrus was found in 30 to 39% of the pd/pd females. Although mating indices were comparable between polydactylous (pd/pd) and phenotypically normal (pd/+ or +/+) females, fertility indices were significantly decreased in pd/pd females. All impregnated pd/pd females delivered normally but had a significant decrease in the numbers of corpora lutea and pups delivered as compared with pd/+ or +/+ females. Examination of oviductal ova at 2 days after copulation revealed ovulation in only 75% of the pd/pd females and also a slight decrease in the numbers of ovulatory corpora lutea and oviductal ova in these females. In the nonovulating persistent estrus pd/pd females, the ovaries were polycystic. These results demonstrate a reduction in reproductive ability of pd/pd females.

Animals↗
PubMed1994

Immunohistochemical localization of transforming growth factor-beta 1, -beta 2, and -beta 3 latency-associated peptide in human cornea.

PURPOSE: To study spatial distribution of TGF-beta isoforms (TGF-beta 1, -beta 2, and -beta 3) in the human cornea and to elucidate their biologic roles in corneal maintenance. METHODS: Frozen sections obtained from eight human autopsy eyes were placed on gelatin-coated slides. After blocking of nonspecific binding sites, the slides were incubated with rabbit polyclonal antibody to the latency-associated peptide (LAP) region of human TGF-beta 1, TGF-beta 2, and TGF-beta 3 precursors, followed by the incubation with biotinylated swine anti-rabbit IgG. Subsequently, a streptavidin-labeled alkaline phosphatase technique was used. RESULTS: In the corneal region, beta 1-LAP antibody did not stain either epithelium or stroma, beta 2-LAP antibody stained all epithelial cell layers and the corneal stroma, and beta 3-LAP antibody stained the subepithelial region alone. The staining pattern in the limbal region was almost the same as in the corneal region, except in the limbal stroma, which was stained with beta 1-LAP antibody in three of eight samples. In the trabecular meshwork, all samples showed clear staining with beta 2-LAP antibody, whereas beta 1-LAP and beta 2-LAP antibody stained faintly in five of eight and four of eight samples, respectively. CONCLUSION: beta 2-LAP was found in the corneal epithelium and stroma and beta 3-LAP in the subepithelial region, suggesting that TGF-beta 2 and TGF-beta 3 may play essential roles in normal corneal epithelial maintenance in vivo.

Adult↗
PubMed1993

A case report of gastric cancer associated with sarcoid reactions in the regional lymph nodes and liver.

Epithelioid cell granulomas identical to those of systemic sarcoidosis are occasionally observed within malignant neoplasms, particularly in the lymphatics draining a primary tumor. These histologic changes have been termed sarcoid reactions and are easily confused with systemic sarcoidosis. This report describes an extremely rare case of gastric cancer accompanied by sarcoid reactions in the regional lymph nodes and liver parenchyma near a tumor metastasis. A 63-year-old woman with advanced gastric cancer was treated by subtotal gastrectomy with dissection of the regional lymph nodes and local excision of the liver tissue involved by metastasis. Microscopic examination of the resected lymph nodes and liver disclosed the presence of sarcoid-like granulomas. The absence of any clinical manifestations and the negative results of the Kveim test, chest radiograph, and laboratory tests, including that for the serum angiotensin converting enzyme excluded the possibility of systemic sarcoidosis. The presence of a sarcoid reaction in the liver parenchyma adjacent to a metastasis has never been reported previously.

Adenocarcinoma↗
PubMed1993

Protease D from the sarcocarp of honeydew melon fruit.

A serine protease was purified from commercially available honeydew melon fruit (Cucumis melo L. var. inodorus Naud) by five steps including CM-Sepharose CL-6B column chromatography. At the first CM-Sepharose CL-6B chromatography four active fractions appeared. No difference in enzymatic properties and M(r) in each fraction was found. Finally, honeydew melon protease D was isolated from the major active fraction D. A M(r) of 50,000 was determined for protease D on SDS-PAGE and gel filtration. Protease D was a glycoprotein. The protease exhibited a remarkable stability, even in 8 M urea or 2 M guanidine hydrochloride for 24 hr. The optimum pH of the enzyme was 11 at 35 degrees using casein as substrate. The enzyme was strongly inhibited by diisopropyl fluorophosphate and was not inhibited by metal-chelating reagents or cysteine protease inhibitors. The enzymatic properties of honeydew melon protease D were similar to those of cucumisin [EC 3.4.21.25], except for its stability at high temperature, wide pH range and against detergents.

Amino Acid Sequence↗
PubMed1993

A two-generation reproduction study in rats with methyl bromide-fumigated diets.

Crj:CD(SD) rats were fed basal (control) diet or methyl bromide-fumigated diet containing 80, 200 or 500 ppm total bromine for two successive generations (18 wk for each generation). Compared with controls, food consumption was significantly lower in F1 parental females of the 500-ppm group during the second half of the dosing period, and F2 female pups of the 500-ppm group showed lower body weights throughout the lactation period. No other treatment-related changes were found at any dietary level of total bromine in either parental animals (F0, F1) or their offspring (F1, F2) for any of the parameters studied (i.e. clinical signs, oestrous cycle, sperm count and morphology, mating, fertility, gestation, parturition, litter size, pup viability, organ weights, and gross or histopathological examination). It was concluded that residues of 200 and 500 ppm total bromine in diets fumigated with methyl bromide are the no-observed-effect level and the minimum toxic level, respectively, for both parental rats and their offspring, and that bromine residues do not affect reproductive performance at dietary levels of up to 500 ppm.

Administration, Oral↗
PubMed1993

Determination of auranofin, a chrysotherapy agent, in urine by HPLC with a postcolumn reaction and visible detection.

Auranofin [(2,3,4,6-tetra-O-acetyl-1-thio-beta-D-glucopyranosato-S) (triethylphosphine)gold(I): AF] is a unique orally active chrysotherapy agent. A HPLC method has been developed for determining AF in urine. The proposed method comprises initial chromatographic separation of AF followed by on-line decomposition by potassium iodide with a released mercapto group undergoing a color-developing reaction with 5,5'-dithiobis(2-nitrobenzoic acid). An aliquot (100 microliters) of a urine sample was chromatographed on a YMC AM-302 octadecylsilica column (4.6 mm i.d. x 15 cm, ambient) with a water-methanol (35:65) eluent delivered at a flow rate of 1 ml/min. A reagent solution for a postcolumn reaction comprised of 50 microM 5,5'-dithiobis(2-nitrobenzoic acid), 0.3 M potassium iodide and a 50 mM phosphate buffer (pH 7.4), was delivered at a flow rate of 0.5 ml/min. The postcolumn reactor consisted of a poly(tetrafluoroethylene) tube (0.5 mm i.d. x 5 m) at 60 degrees C. Detection wavelength was 412 nm. The identity of the AF peak was confirmed by a 3-dimensional chromatogram as well as by atomic absorption spectrophotometric analysis of gold in the column effluent. Under the conditions described above, a linear relationship was obtained between peak height and AF concentration in the range 0.1 to 10 microM, with a correlation coefficient of 0.999. The detection limit was 50 nM (S/N = 3 at 0.005 AUFS) and the reproducibility was within 4% for 5 determinations. The AF concentrations in the urine of a rabbit given AF intraperitoneally were determined.

Animals↗
PubMed1993

Role of the extracellular Ca2+ on the intracellular Ca2+ changes in fertilized and activated mouse oocytes.

Changes in intracellular calcium concentration ([Ca2+]i) in fertilized mouse oocytes were measured using the calcium-sensitive dye, fura-2. After fertilization, an initial long-lasting [Ca2+]i increase was followed by a periodic [Ca2+]i increase. The periodic increase in [Ca2+]i persisted for 1 to 3 h and all fertilized oocytes extruded the second polar body within 4 h. The mean interval of periodic [Ca2+]i increase was 470 +/- 180 s (mean +/- SD). The frequency of the periodic [Ca2+]i increase depended on the extracellular calcium concentration. Verapamil and nifedipine inhibited the periodic [Ca2+]i increase. Sixty-five per cent of tested cells extruded the second polar body within 90 min of exposure to 7% ethanol. In these activated oocytes, the long-lasting [Ca2+]i increase was observed. However, no cells showed a repetitive increase in [Ca2+]i. Both release of calcium from intracellular stores and influx of extracellular calcium contribute to the increase in [Ca2+]i induced by ethanol. We conclude that the extrusion of the second polar body requires an increase in [Ca2+]i above a certain threshold level and the mobilization of calcium of both the intracellular and extracellular space in mouse oocytes.

Animals↗
PubMed1993

Usefulness of a simplified artificial insemination technique in the rabbit for teratology studies.

We describe usefulness of our simplified artificial insemination technique in rabbits for teratology studies. Our technique includes 1) semen collection from 2 or 3 bucks with a simple artificial vagina, 2) deposition of 0.5 microliters of the diluted semen mixture in the vagina with a glass pipette, and 3) injection of 25 U. of hCG through the auricular vein. Applying these techniques and procedures and keeping about 10 proven bucks would enable 2 operators to inseminate 10-15 does daily by only 1 hour work. This artificial insemination technique should be useful for rabbit teratology studies, especially for safety evaluation studies of toxicants, where a relatively large number of pregnant are needed to be prepared in a short period.

Animals↗
PubMed1992

The interaction of botrocetin with normal or variant von Willebrand factor (types IIA and IIB) and its inhibition by monoclonal antibodies that block receptor binding.

We have recently shown the existence of two distinct forms of botrocetin (one-chain and two-chain), and demonstrated that the two-chain species is approximately 30 times more active than the one-chain in promoting von Willebrand factor (vWF) binding to platelet glycoprotein (GP) Ib. The N-terminal sequence of two-chain botrocetin is highly homologous to sea-urchin Echinoidin and other Ca(2+)-dependent lectins (Fujimura et al., Biochemistry 1991; 30: 1957-64). Present data indicate that purified two-chain botrocetin binds to vWF from plasmas of patients with type IIA or IIB von Willebrand disease and its interaction is indistinguishable from that with vWF from normal individuals. However, an "activated complex" formed between botrocetin and IIB vWF expresses an enhanced biological activity for binding to GP Ib whereas the complex with IIA vWF has a decreased binding activity. Among several anti-vWF monoclonal antibodies (MoAbs) which inhibit ristocetin-induced platelet aggregation and/or vWF binding to GP Ib, only two MoAbs (NMC-4 and RFF-VIII RAG:1) abolished direct binding between purified botrocetin and vWF. This suggests that they recognize an epitope(s) on the vWF molecule in close proximity to the botrocetin binding site.

Antibodies, Monoclonal↗
PubMed1992

Voltage-dependent ionic currents in solitary horizontal cells isolated from cat retina.

1. Horizontal cells of the cat retina were isolated by enzymatic dissociation. Two types of horizontal cells were identified: the axonless (A-type) horizontal cell having four to six thick, long (approximately 100 microns) dendrites, and the short-axon (B-type) horizontal cell having many (> 5) fine, short (approximately 30 microns) dendrites. 2. Membrane properties of isolated horizontal cells were analyzed under current-clamp and voltage-clamp conditions. In the A-type cell, the average resting potential was -55 mV and the mean membrane capacitance was 110 pF, whereas values in the B-type cell were -58 mV and 40 pF, respectively. The A-type cell showed long-lasting Ca spikes, but B-type cells had no Ca spikes. 3. Five types of voltage-dependent ionic currents were recorded: a sodium current (INa), a calcium current (ICa), and three types of potassium currents. Potassium currents consisted of potassium current through the inward rectifier (Ianomal), transient outward potassium current (IA), and potassium current through the delayed rectifier (IK(v)). INa was recorded only from A-type cells. Other currents were recorded from both types of cells. 4. INa activated when cells were depolarized from a holding potential (Vh) of -95 mV, and it was maximal at -25 mV. This current was blocked by tetrodotoxin. Approximately half of the A-type cells had INa, but no B-type cell had this current. 5. L-type ICa, an inward-going sustained current, was activated with depolarization more positive than -25 mV. Current amplitude reached a maximal value near 15 mV and became smaller with further depolarization.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗