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Biomedical subjects

Y Hara

Publications and source records attributed to Y Hara.

At least 19 recordsLinked to original sources
PubMed1992

A marine algal Na(+)-activated ATPase possesses an immunologically identical epitope to Na+,K(+)-ATPase.

Immunological homology was investigated between Heterosigma akashiwo (a marine algae) Na(+)-activated ATPase and animal Na+,K(+)-ATPase. The former polypeptide [(1989) Plant Cell Physiol. 30, 923-928] reacted with anti-serum raised against the amino-terminal half of the pig kidney Na+,K(+)-ATPase alpha subunit. It is suggested that the Na+,K(+)-ATPase epitope within the amino-terminal region is conserved in the plant Na(+)-activated ATPase, and the region containing the epitope may be important for Na ion transport.

Antibodies↗
PubMed1992

Analysis of an in vitro-generated signal that induces systemic immune deviation similar to that elicited by antigen injected into the anterior chamber of the eye.

The selective deficit in delayed hypersensitivity that characterizes anterior chamber-associated immune deviation (ACAID) is the direct result of a blood borne, Ag-specific, cell-associated signal that is created after Ag is injected into the anterior chamber of the eye of normal mice. The cells that carry this signal via the blood to the spleen express the mature macrophage marker F4/80 and are similar to, or perhaps even arise from, F4/80+ dendritic cells found within the stroma of normal iris and ciliary body. We have recently reported that ACAID-inducing properties can be conferred upon conventional F4/80-bearing macrophages harvested from the normal peritoneal cavity by incubating these cells in vitro with the soluble protein Ag, BSA, in the presence of supernatants harvested from cultured iris and ciliary body cells. Using this in vitro induction system, we have examined the limiting conditions for conferring ACAID-inducing potential on peritoneal exudate cells. We have found that an ACAID-inducing signal can be created in vitro with several different soluble Ag, including the retinal autoantigen-interphotoreceptor retinol binding protein, and that active endocytosis and processing by peritoneal exudate cells is required because chloroquine prevents these cells from acquiring ACAID-inducing properties. In addition, we have determined that for supernatant-treated peritoneal macrophages to induce ACAID to soluble Ag the cells must be 1) alive, 2) injected i.v. or i.p. (but not s.c.), and 3) administered to recipients with an anatomically intact spleen. When these conditions are met, as few as 20 F4/80+ macrophages pulsed with Ag in the presence of iris and ciliary body supernatants are sufficient to induce ACAID. Macrophage hybridomas derived from "conventional" APC can acquire ACAID-inducing potential in vitro if exposed to iris and ciliary body supernatants, whereas macrophage hybridomas derived from "suppressor inducer" APC constitutively possess ACAID-induced potential. Peritoneal macrophages that were endowed with ACAID-inducing properties by in vitro exposure to supernatants were found to elicit splenic suppressor cells similar to those found in spleens of mice with ACAID. Moreover, the expression of experimental autoimmune uveitis in mice immunized with interphotoreceptor retinol binding protein was significantly suppressed if the animals were pretreated with peritoneal exudate cells pulsed with this Ag in the presence of iris and ciliary body supernatants.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Structure and evolution of four POU domain genes expressed in mouse brain.

Four mouse POU domain genomic DNA clones--Brain-1, Brain-2, Brain-4, and Scip--and Brain-2 cDNA, which are expressed in adult brain, were cloned and the coding and noncoding regions of the genes were sequenced. The amino acid sequences of the four POU domains are highly conserved; sequences in other regions of the proteins also are conserved but to a lesser extent. The absence of introns from the coding regions of the four POU domain genes and the similarity of amino acid sequences of the corresponding proteins suggest that the coding region of the ancestral class III POU domain gene lacked introns and therefore may have originated by reverse transcription of a molecule of POU domain mRNA followed by insertion of the cDNA into germ cell genomic DNA. Additional duplications of the ancestral class III POU domain gene (or mRNA) would create the Brain-1, Brain-2, Brain-4, and Scip genes.

Amino Acid Sequence↗
PubMed1992

Suppression of experimental autoimmune uveitis in mice by induction of anterior chamber-associated immune deviation with interphotoreceptor retinoid-binding protein.

Immunization with bovine interphotoreceptor retinoid-binding protein induces autoimmune uveitis in B10.A mice. We have examined whether this soluble retina-specific Ag can induce anterior chamber-associated immune deviation when injected into the anterior chamber (AC) of the eye, and whether this deviant immune response has any effect on uveitis is susceptible mice. The results of these experiments indicate that interphotoreceptor retinoid-binding protein (IRBP) injected intracamerally altered the subsequent immune response of B10.A mice such that a) they were not able to develop IRBP-specific delayed hypersensitivity, nor (b) were they able to express significant autoimmune uveitis following a uveitogenic regimen. Moreover, spleen cells from mice that received IRBP in the AC suppressed uveitis when adoptively transferred into naive recipients. The splenic suppressor cells were able to prevent autoimmune uveitis in recipient mice when administered after the uveitogenic regimen. Most important, IRBP-specific splenic cells from mice treated with IRBP in the AC when injected into mice with established uveitis caused an abrupt cessation of the intraocular inflammation. The ability of intracamerally-injected soluble Ag to induce suppressor T cells that act on the efferent limb of the immune response suggests that the anterior-chamber-associated immune deviation phenomenon may have physiologic relevance in terms of preservation of the integrity of ocular tissue and renders this approach particularly suitable for treating already established experimental autoimmune diseases of this type. These results are discussed in terms of other methods that have been devised experimentally to suppress and prevent autoimmune uveitis and encephalomyelitis.

Animals↗
PubMed1992

Stimulation of human monocyte and polymorphonuclear cell iodination and interleukin-1 production by epigallocatechin gallate.

(-)Epigallocatechin gallate (EGCg) stimulated iodination of human peripheral blood monocytes, polymorphonuclear cells (PMN), and human promyelocytic leukemic HL-60 cells, dependent on time, dose, and temperature. However, EGCg did not affect iodination of nonadherent peripheral blood mononuclear cells, red blood cells, or 11 other cultured cell lines. Although various immunoregulators such as lipopolysaccharide (LPS), opsonized zymosan, 12-O-tetradecanoylphorbol-13-acetate (TPA) and tumor necrosis factor stimulated PMN iodination to varying degrees, their ability to stimulate monocyte iodination was much lower than that of EGCg. Washout experiments demonstrated that contact with EGCg for less than 60 min irreversibly stimulated PMN and monocyte iodination. EGCg also potently stimulated the production of interleukin-1-like factor by monocytes. The data suggest that EGCg is a strong in vitro stimulant of human phagocytes.

Adjuvants, Immunologic↗
PubMed1992

Anorexia nervosa responding to zinc supplementation: a case report.

An emaciated 16-year-old female with anorexia nervosa was hospitalized for treatment of vomiting, epigastralgia and diarrhea. The finding of a taste disorder, low serum alkaline phosphatase activity and relatively low serum zinc level strongly suggested a zinc deficiency. Zinc was initially administered intravenously (40 mumol/day) for 7 days, then orally (15 mg elemental zinc/day) for about 60 days. Her digestive symptoms disappeared after the second day of intravenous treatment and she began to gain weight. She rapidly regained her normal weight after one month of receiving the oral zinc supplementation. Both exocrine pancreatic function and intestinal absorption were improved by the prolonged oral administration of zinc. In such cases zinc supplementation may be a therapeutic option in addition to psychologic and other approaches to management.

Adolescent↗
PubMed1992

Central cardiovascular effects of physostigmine in anesthetized cats.

The central cardiovascular effects of a cholinesterase inhibitor, physostigmine, were studied in alpha-chloralose- and urethane-anesthetized cats, to determine the underlying site and mechanism of action. Intravenous injection of physostigmine produced a dose-dependent fall in blood pressure and heart rate. These responses were blocked by intravenous injection of atropine; however, the peripheral antimuscarinic agent, methscopolamine, failed to inhibit the depressor response. In decerebrated cats, physostigmine elicited similar responses in blood pressure and heart rate as in intact animals. In spinal cats, physostigmine failed to evoke any response. Physostigmine significantly reduced sympathetic nervous activity, as measured by renal sympathetic nerve discharges, indicating that the fall in blood pressure was due to a decrease in sympathetic tone. These results demonstrate that physostigmine, which crosses the blood-brain barrier, produces a depressor response through stimulation of muscarinic cholinergic receptors, located in the medullary region and that the effect is mediated by a decrease in sympathetic activity.

Anesthesia↗
PubMed1992

Mitogenic activity of (-)epigallocatechin gallate on B-cells and investigation of its structure-function relationship.

(-)Epigallocatechin gallate (EGCg), the main constituent of green tea, strongly enhanced the direct plaque-forming cell (PFC) response to sheep red blood cells (SRBC) in vitro and showed strong mitogenic activity for mouse splenic B-cells but not for splenic T-cells and thymocytes. The enhancement of B-cell proliferation was not mediated by macrophages since their removal did not eliminate the activity. Among the derivatives of catechin examined, (+)catechin (C); (-)epicatechin (EC); (-)-epigallocatechin (EGC); (-)epicatechin gallate (ECg); (-)epigallocatechin gallate (EGCg); and theaflavin digallate (TF3), only the derivatives with the galloyl group (ECg, EGCg, and TF3) displayed significant enhancement of the spontaneous proliferation of B-cells. Structural analogs of the catechin and galloyl groups were also examined in the system. Gallic acid and tannic acid induced some enhancement, but rutin, pyrogallol and caffeine did not. The results indicate that the galloyl group on EGCg was responsible for enhancement. However, the basic conformations of the catechins are also important, because ECg, EGCg, TF3, gallic acid, and tannic acid had quite different potencies to induce B-cell proliferation.

Adjuvants, Immunologic↗
PubMed1992

Breed differences in the histochemical properties of the M. iliotibialis lateralis myofibre of domestic cocks.

1. Reduced nicotinamide adenine dinucleotide dehydrogenase (NADH-DH) activity in the M. iliotibialis lateralis was compared histochemically among 7 breeds of cocks. This muscle was composed only of Type-IIA and -IIB fibres. 2. Apparent breed differences were observed in muscle development, the NADH-DH activity in every fibre type, fibre type distribution and fibre diameters. 3. From the results of this study, it was concluded that the muscle characteristics of various breeds were based not only on the fibre type composition, but also the different activities of oxidative enzyme in every type.

Animals↗
PubMed1992

Intraarterial infusion chemotherapy with [Sar1,Ile8]angiotensin II for bladder cancer.

Thirty-three patients with primary bladder cancer (nine stage T1 with multifocal tumors and 24 stage T2-4) were treated with intraarterial infusion chemotherapy including cisplatin, doxorubicin, and [Sar1,Ile8]Angiotensin II(AT II). Of the 32 evaluable patients, 12 had pathologically proven complete response (CR), 19 showed partial response (PR), and one showed no change (NC); the overall response rate (CR + PR) was 97%. The blood pressure increased in response to the administration of [Sar1,Ile8]AT II in all the patients; the mean increase in the systolic blood pressure was 36 mmHg. Most of the side effects were mild to moderate in severity, transient in nature, and included nausea/vomiting (100%), alopecia (84%), leukopenia (66%), headache (9%), nephrotoxicity (6%), diarrhea (3%), skin pigmentation (3%), and neurotoxicity (3%). One patient who dropped out of the study developed hemiplegia as a result of cerebral infarction. The findings indicate that it is necessary to exercise caution in selecting the patients to be subjected to this therapy. We conclude that intraarterial infusion chemotherapy combined with a vasoconstrictor has a significant effect not only against multifocal superficial bladder cancer but also against invasive bladder cancer.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1992

Cystatin activity in gingival crevicular fluid from periodontal disease patients measured by a new quantitative analysis method.

Cystatins are protein inhibitors of cysteine proteinases, which are believed to play an important role in the pathogenesis of periodontal disease. In this study, we report a new sensitive method for the quantitative analysis of cystatin activity in a small amount of crude sample such as gingival crevicular fluid. Cystatin activity in the crude sample was determined by using active site-titrated papain, which is a cysteine proteinase from the plant Carica papaya. Crude samples usually contain endogenous cysteine proteinases. These competed with the added papain for the active sites of the cystatins. The cystatin-cysteine proteinase complex was able to be dissociated by the addition of papain. This competition and dissociation could interfere with the determination of cystatin activity, since some of the cysteine proteinases, such as cathepsin B, hydrolyzed the specific substrate for papain during titration with the papain. In order to exclude this interference and measure total cystatin activity, the crude sample must be alkalinized (pH 11.0) for 5 min at 4 degrees C followed by 10 min at 40 degrees C before titration with papain. The minimum detectable amount of cystatins was 20 fmol/assay when it was calculated per mole of papain inhibitory sites. Using this method, significant levels of cystatin activity were detected in all the samples of gingival crevicular fluid taken from periodontal disease patients. These results suggest that cystatins could regulate the cysteine proteinases in gingival crevicular fluid and that this new method could be useful to clarify the role of cystatins in the pathogenesis of periodontal disease.

Alkalies↗
PubMed1992

A possible mechanism of endothelium-dependent relaxation induced by pirarubicin and carbachol in rat isolated aorta.

The mechanism of endothelium-dependent relaxation induced by pirarubicin, (2''R)-4'-O-tetrahydropyranyladriamycin, THP, or carbachol was investigated in the rat isolated aorta. The relaxant effect of THP (1.5 x 10(-6)-4.5 x 10(-5) M) or carbachol (10(-8)-10(-4) M) on the aorta with endothelium was decreased by lowering Ca2+ in the medium. The relaxation induced by THP was not inhibited by pretreatment with verapamil (10(-6)-10(-5) M), and that induced by carbachol was only partially inhibited. However, on replacement of all but 20 mM Na+ with either Li+ or choline, the THP- or carbachol-induced relaxation was inhibited. Furthermore, the relaxing effect of THP or carbachol was inhibited by pretreatment with amiloride (10(-4)-3 x 10(-4) M), with ouabain (10(-4)-10(-3) M), or with K(+)-depletion. These results suggest that the THP- or carbachol-induced relaxation depending on endothelium was affected by modifying the calcium ion concentration, and that a Na(+)-Ca2+ exchange process is involved.

Amiloride↗
PubMed1992

Inhibitory effects of tiamulin on contractile and electrical responses in isolated thoracic aorta and cardiac muscle of guinea-pigs.

The inhibitory effect of tiamulin, an antibiotic produced by Pleurotus mutilis, on contractile and electrical responses in isolated thoracic aorta and cardiac muscle of guinea-pigs was studied. In the thoracic aorta, tiamulin with an IC50 of 9.7 x 10(-6) M inhibited sustained contractions induced by isosmotically added 60 mM KCl. The inhibitory effect of tiamulin on a Ca(2+)-induced contraction in a depolarized muscle was competitively antagonized by raising external Ca2+ concentration. Bay K 8644 (10(-7) M) antagonized tiamulin's inhibition of the Ca(2+)-induced contraction. Tiamulin (2 x 10(-5) M) decreased the elevated cytoplasmic Ca2+ level measured by the fura 2 AM method in the depolarized muscle. In high K(+)-isoprenaline-treated left atria, tiamulin (2 x 10(-5)-2 x 10(-4) M) produced negative inotropic effects. On the other hand in the membrane action potential of papillary muscles, tiamulin (2 x 10(-6)-2 x 10(-4) M) produced decreases in action potential and durations and 2 x 10(-4) M tiamulin depressed the slow response action potential in depolarized muscles. Tiamulin produced prolongations of the PR interval in ECG, negative chrono- and inotropic effects, and an increase in perfusion flow in guinea-pig isolated and perfused hearts. These effects of tiamulin on the aorta or cardiac muscle were similar to those of verapamil and nifedipine. These results suggest that both the inhibitory action of tiamulin on the high K(+)-induced contraction in the aorta and the negative inotropic effect of tiamulin on the cardiac muscle are due to an inhibition of Ca2+ entry through the voltage-dependent Ca2+ channels of cells of both these muscles.

Action Potentials↗
PubMed1992

[Protective activity of tea and catechins against Bordetella pertussis].

We examined the bactericidal activity of tea and catechins against Bordetella pertussis. Green tea, black tea and coffee showed marked bactericidal activity at their concentrations in beverages, while pu-erh tea killed the bacteria in a moderate way. (-) Epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) showed also marked bactericidal activity. Green tea and black tea also effectively blocked the adhesion of B. pertussis to HeLa and CHO cells, whereas ECGg and TF3 could not. EGCg and TF3 markedly inactivated leuco-lymphocytosis promoting activity of pertussis toxin. Black tea showed slight but significant inactivation of the activity, whereas green tea showed no inactivation. These results suggest that green tea, black tea, EGCg and TF3 might act as prophylactic agents against pertussis infection.

Animals↗
PubMed1992

[Antimicrobial and microbicidal activities of tea and catechins against Mycoplasma].

We examined tea extracts, (-) epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) for their antimicrobial and microbicidal activities against Mycoplasma. Green tea and black tea showed antimicrobial activities against M. pneumoniae. At a concentration of 0.2% green tea and black tea showed microbicidal activities against M. pneumoniae and M. orale but not against M. salivarium. Extracts of pu-erh tea showed a slight microbicidal activity against M. pneumoniae and M. orale. EGCg purified from green tea and TF3 from black tea markedly showed microbicidal activities against M. pneumoniae. M. orale and M. salivarium. These results suggest that tea and catechins can be used as prophylactic agents against Mycoplasma pneumoniae infection.

Biflavonoids↗
PubMed1992

Lambert-Eaton myasthenic syndrome without anti-calcium channel antibody: adverse effect of calcium antagonist diltiazem.

A 59 year old man with ischaemic heart disease, developed the clinical and electromyographic changes of the Lambert-Eaton myasthenic syndrome after taking calcium antagonist, diltiazem. The symptoms appeared periodically with a rise and fall in serum level of diltiazem. Extensive search was made for systemic neoplasms and autoimmune diseases without success. Serum antibody to voltage operated calcium channel was not detected.

Autoantibodies↗