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1.
J Small Anim Pract ; 47(9): 541-4, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16961473

ABSTRACT

A five-year-old, male crossbreed rabbit was referred for acute caudal abdominal swelling. On physical examination, the rabbit was slightly depressed and showed an enlarged subcutaneous cyst in the caudal abdomen and an adjacent small, ulcerated solid mass. A drainage tube was placed in the cystic area, and surgical resection of the solid mass was performed. The histopathological diagnosis of the mass was apocrine adenocarcinoma. To the authors' knowledge, this report describes the first case of spontaneous apocrine adenocarcinoma of possible sweat gland origin in a male rabbit.


Subject(s)
Adenocarcinoma/veterinary , Apocrine Glands/pathology , Rabbits , Sweat Gland Neoplasms/veterinary , Adenocarcinoma/diagnosis , Adenocarcinoma/pathology , Adenocarcinoma/surgery , Animals , Apocrine Glands/surgery , Male , Sweat Gland Neoplasms/diagnosis , Sweat Gland Neoplasms/pathology , Sweat Gland Neoplasms/surgery
2.
Diabetes ; 46(10): 1548-56, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9313748

ABSTRACT

Islet cell antigen p69 (ICA69) is a target autoantigen in IDDM. Studies of T-cells from newly diabetic children suggested possible antigenic mimicry between human ICA69 (in particular the Tep69 T-cell epitope, aa 36-47) and the ABBOS region in bovine serum albumin (BSA; aa 152-169), one of several cow's milk proteins that evoke abnormal immunity in diabetes-prone hosts. We recently found the sequence of Tep69 regions to be identical in the four alternatively spliced human and rodent ICA69 isoforms. Immunization of nonobese diabetic (NOD) mice with BSA or ICA69 generates fully cross-reactive T-cell responses to both Tep69 and ABBOS as the immunodominant, naturally generated, and presented T-cell mimicry epitopes. Such responses are absent or weak in healthy strains of mice. NOD mouse recipients of adoptive spleen cell grafts from diabetic donors spontaneously generate easily detectable pools of T-cells specific for ICA69/BSA, as well as the unrelated GAD65. NOD mice injected neonatally with ABBOS or Tep69 show cross-tolerance, but ABBOS-induced tolerance is transient. Neonatal injection of Tep69 reduces disease incidence (23 vs. 68% IDDM, P < 0.02), while neonatal injection of ABBOS has little effect. In contrast, systemic immunization of young NOD females with ABBOS (but not Tep69) reduces the diabetes incidence and delays disease expression, with protected mice generating ABBOS-specific T-cell repertoires unable to recognize the Tep69 mimicry antigen. Our observations demonstrate a loss of self-tolerance to ICA69 in NOD mice, and they establish antigenic mimicry between the two T-cell epitopes in ICA69 and BSA. Further studies are necessary to understand the molecular basis of this mimicry and how either T-cell peptide can modify the disease course.


Subject(s)
Autoantigens/immunology , Diabetes Mellitus/immunology , Immune Tolerance , Adoptive Transfer , Amino Acid Sequence , Animals , Animals, Newborn/immunology , Immunization , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Inbred DBA , Mice, Inbred NOD , Molecular Mimicry , Molecular Sequence Data , Nerve Tissue Proteins , Peptide Fragments/immunology , Serum Albumin, Bovine/immunology , Spleen/immunology , T-Lymphocytes/immunology
3.
Diabetes ; 46(4): 557-64, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9075794

ABSTRACT

Human epidemiological studies delineated early exposure to intact dietary protein (e.g., most infant formulas) as an environmental risk factor for the development of IDDM. The Trial to Reduce IDDM in the Genetically at Risk (TRIGR), an international IDDM prevention trial, has been designed to determine if avoidance of intact dairy protein in high-risk infants < or =6 months of age can reduce the subsequent diabetes incidence. We here studied the casein hydrolysate-based trial diet (Nutramigen) in NOD mice. When given either continuously or for 10 weeks after weaning, the test diet was highly effective in preventing autoimmune diabetes (32-week incidence: 4.6 vs. 58.8%) and in preserving pancreatic insulin levels, with little effect on islet inflammation. Spleen cells from protected NOD mice failed to adoptively transfer diabetes into irradiated syngeneic recipients. When co-transferred with splenocytes from diabetic donors, cells from diet-protected mice inhibited adoptive diabetes transfer (incidence 50 vs. 94%, P < 0.001). T-cell reactivity to the islet cell autoantigens ICA69 (islet cell antigen 69) and GAD65 developed only in diabetic recipients of spleen cell grafts, indicating that diabetes protection extends to more than one autoantigen. In protected mice, ICA69 T-cell reactivity was not detectable spontaneously nor after priming with this autoantigen; however, priming with the cross-reactive non-self-antigen bovine serum albumin recruited T-cells responsive to ICA69. Thus, diabetes prevention with the clinical trial diet is effective in NOD mice, where it affects some T-cell repertoires and allows development of regulatory cells that interfere with destructive autoimmunity.


Subject(s)
Adoptive Transfer , Autoantigens/immunology , Caseins/immunology , Diabetes Mellitus, Type 1/prevention & control , Spleen/cytology , T-Lymphocytes/immunology , Animals , Caseins/administration & dosage , Caseins/chemistry , Cattle , Cross Reactions , Diabetes Mellitus, Type 1/epidemiology , Diabetes Mellitus, Type 1/immunology , Diet , Disease Models, Animal , Female , Hydrolysis , Incidence , Insulin/analysis , Islets of Langerhans/pathology , Male , Mice , Mice, Inbred NOD , Ovalbumin/immunology , Pancreas/chemistry , Pilot Projects , Serum Albumin/immunology , Spleen/immunology , Time Factors
4.
Plant Physiol ; 110(2): 387-392, 1996 Feb.
Article in English | MEDLINE | ID: mdl-12226190

ABSTRACT

It has been suggested that jasmonic acid (JA) could be an integral part of a general signal transduction system regulating inducible defense genes in plants. It was reported that treatment with an elicitor (N-acetylchitoheptaose) induced production of phytoalexin in suspension-cultured rice (Oryza sativa L.) cells. In this study, the role of JA in the induction of phytoalexin production by N-acetylchitoheptaose was investigated. Exogenously applied ([plus or minus])-JA (10-4 M) clearly induced the production of momilactone A, a major phytoalexin, in suspension-cultured rice cells. On the other hand, in rice cells treated with N-acetylchitoheptaose, endogenous JA was rapidly and transiently accumulated prior to accumulation of momilactone A. Treatment with ibuprofen, an inhibitor of JA biosynthesis, reduced production of momilactone A in the cells treated with N-acetylchitoheptaose, but the addition of ([plus or minus])-JA increased production of momilactone A to levels higher than those in the elicited rice cells. These results strongly suggest that JA functions as a signal transducer in the induction of biosynthesis of momilactone A by N-acetylchitoheptaose in suspension-cultured rice cells.

5.
Arch Intern Med ; 148(4): 921-5, 1988 Apr.
Article in English | MEDLINE | ID: mdl-2895617

ABSTRACT

To clarify the mechanism of development of hypercalcemia in adult T-cell leukemia/lymphoma (ATLL), ten patients with a serum creatinine level less than 177 mumol/L (2 mg/dL) were examined. Although hypercalcemia was seen in only four (40%) of these patients, four of six normocalcemic patients showed hypercalciuria (greater than 5 mmol/d [greater than 200 mg/24 h]). All hypercalcemic patients exhibited high nephrogenous cyclic adenosine monophosphate (NcAMP) levels in the face of low-normal immunoreactive parathyroid hormone and reduced serum 1,25-dihydroxyvitamin D [1,25(OH)2D] concentration. Half of the hypercalciuric patients with normocalcemia also showed high NcAMP and reduced serum 1,25(OH)2D levels. Furthermore, the changes in NcAMP and serum 1,25(OH)2D concentration closely paralleled the development of hypercalcemia and hypercalciuria in two patients. These results are reminiscent of the syndrome of humoral hypercalcemia of malignancy and suggest that derangements in calcium metabolism develop by a similar mechanism in patients with ATLL. The present data also indicate the importance of the measurement of urinary calcium excretion for early detection and prevention of fatal hypercalcemia in patients with ATLL.


Subject(s)
Calcium/blood , Deltaretrovirus Infections/blood , Hypercalcemia/blood , Adult , Aged , Calcium/urine , Cyclic AMP/blood , Deltaretrovirus Infections/urine , Female , Humans , Hypercalcemia/urine , Male , Middle Aged , Parathyroid Hormone/blood , Vitamin D/blood
6.
Eur Psychiatry ; 30(2): 291-5, 2015 Feb.
Article in English | MEDLINE | ID: mdl-24768472

ABSTRACT

BACKGROUND: It has been shown that certain personality traits are related to mortality and disease morbidity, but the biological mechanism linking them remains unclear. Telomeres are tandem repeat DNA sequences located at the ends of chromosomes, and shorter telomere length is a predictor of mortality and late-life disease morbidity. Thus, it is possible that personality traits influence telomere length. In the present study, we examined the relationship of leukocyte telomere length with personality traits in healthy subjects. SUBJECTS AND METHODS: The subjects were 209 unrelated healthy Japanese who were recruited from medical students at 4th-5th grade. Assessment of personality traits was performed by the Revised NEO Personality Inventory (NEO-PI-R) and the Temperament and Character Inventory (TCI). Leukocyte relative telomere length was determined by a quantitative real-time PCR method for a ratio of telomere/single copy gene. RESULTS: In the stepwise multiple regression analysis, shorter telomere length was related to lower scores of neuroticism (P<0.01) and conscientiousness (P<0.05) of the NEO-PI-R, and lower scores of harm avoidance (P<0.05) and reward dependence (P<0.05) of the TCI. CONCLUSIONS: The present study suggests that leukocyte telomere length is associated with some personality traits, and this association may be implicated in the relationship between personality traits and mortality.


Subject(s)
Asian People/statistics & numerical data , Leukocytes , Personality , Telomere , Adult , Anxiety Disorders , Character , Cooperative Behavior , Extraversion, Psychological , Female , Healthy Volunteers , Humans , Japan , Male , Mortality , Neuroticism , Personality/genetics , Personality Inventory , Reward , Self Efficacy , Temperament
7.
J Neuropathol Exp Neurol ; 43(4): 426-38, 1984 Jul.
Article in English | MEDLINE | ID: mdl-6610726

ABSTRACT

The effect of intravenously injected tumor immune spleen cells on growth of 3 X 10(5) gliosarcoma T9 cells injected intradermally (ID) or intracerebrally (IC) into sublethally irradiated CDF rats was evaluated. Spleen cells from donor rats with sufficient immunity to reject 5 X 10(5) T9 cells inhibited the growth of T9 cells mixed with spleen cells in a ratio of 1:25 and injected ID, but could not act after intravenous transfer. However, donor rats which had rejected increasing T9 challenge doses up to 1 X 10(7) cells produced immune spleen cells which, upon IV transfer, could inhibit growth of ID T9 challenge but not of EB-679, an unrelated glioma, in recipient rats. Rejection of IC T9 challenge was also obtained after IV transfer, in recipients of such "hyperimmune" spleen cells, but was less (60% maximum) than that noted after ID T9 challenge (100% maximum). The removal of B cells from the transferred spleen cells did not affect the results, suggesting that the specific immunity was mediated by T cells. We conclude that the special immunological circumstances of tumors growing in the brain renders them less accessible to rejection by systemically transferred immune cells, but it is nevertheless possible to effect a significant incidence of rejection of syngeneic tumor growth in the brain by the intravenous transfer of hyperimmune spleen cells.


Subject(s)
Brain Neoplasms/immunology , Glioma/immunology , Immunization, Passive , Neoplasm Transplantation , Animals , Male , Nitroso Compounds , Rats , T-Lymphocytes/immunology , Urea
8.
Endocrinology ; 118(4): 1440-4, 1986 Apr.
Article in English | MEDLINE | ID: mdl-3512255

ABSTRACT

To evaluate the role of insulin in the regulation of circulating 1,25-dihydroxyvitamin D [1,25(OH)2D] levels, serum 1,25(OH)2D concentrations in response to phosphorus (P) deprivation were examined in control, streptozotocin-diabetic and insulin-treated diabetic rats. Dietary P deprivation for 1 week caused a marked increase in serum 1,25(OH)2D level from 75 +/- 4 pg/ml to 274 +/- 16 pg/ml in control rats. In contrast, serum 1,25(OH)2D level was significantly lower in diabetic rats on a normal P diet (20 +/- 2 pg/ml) compared to that in control rats and increased only slightly by P deprivation (33 +/- 4 pg/ml). Treatment of the diabetic rats on normal P diet with insulin caused an increase in serum 1,25(OH)2D concentration to a level (82 +/- 10 pg/ml) similar to that in control rats and restored the increase in serum 1,25(OH)2D concentration in response to P deprivation (315 +/- 38 pg/ml). Although there was a marked decrease in serum phosphate level by P deprivation in all groups of animals, the rise in serum calcium level by P deprivation seen in control rats was abolished in diabetic rats. In addition, while bone mineral contents decreased significantly in response to P deprivation in control rats, no significant changes in either bone calcium or P contents were observed after P deprivation in diabetic rats. Insulin treatment of the diabetic rats recovered the responsiveness to P deprivation in both serum calcium level and bone mineral contents. P deprivation did not affect plasma glucose or serum creatinine level in any group of rats. These results suggest that insulin, either directly or indirectly, is required for the increase in circulating 1,25(OH)2D concentrations in response to P deprivation, and that the rise in serum 1,25(OH)2D level may play a role in the hypercalcemic response to P deprivation.


Subject(s)
Calcitriol/blood , Diabetes Mellitus, Experimental/blood , Insulin/pharmacology , Phosphorus/physiology , Animals , Body Weight/drug effects , Bone and Bones/analysis , Calcium/blood , Creatinine/blood , Energy Intake , Male , Phosphates/blood , Rats , Rats, Inbred Strains
9.
FEBS Lett ; 326(1-3): 80-2, 1993 Jul 12.
Article in English | MEDLINE | ID: mdl-7686865

ABSTRACT

The rate of bait region cleavage of human alpha-2-macroglobulin by chymotrypsin was determined by a rapid quenching method under conditions where the bimolecular encounter between the two reactants was not rate-limiting. alpha 2M was first mixed with a 30 molar excess of chymotrypsin in a sequential stopped-flow apparatus and after programmed time intervals the activity of chymotrypsin was quenched with 1 N HCl. The fraction of uncleaved subunits was quantitated by SDS-PAGE under reducing conditions. The result indicated that the bait region cleavage proceeded following a two-exponential decay curve with respective rate constants of k1 = 40 s-1 and k2 = 2 s-1.


Subject(s)
Chymotrypsin/metabolism , alpha-Macroglobulins/metabolism , Binding Sites , Electrophoresis, Polyacrylamide Gel , Humans , Hydrochloric Acid , Kinetics , Male
10.
FEBS Lett ; 306(2-3): 176-80, 1992 Jul 20.
Article in English | MEDLINE | ID: mdl-1378792

ABSTRACT

A stable subunit of Sambucus sieboldiana bark lectin (MSSA) was prepared by selective reduction of disulfide bridges between the subunits and alkylation with 4-vinylpyridine. Amino acid analysis of MSSA revealed that 1.4 cysteine residues per subunit were selectively modified. MSSA failed to agglutinate rabbit erythrocytes and precipitate fetuin. However, MSSA retained the ability to bind to fetuin, as detected by ELISA. Neu5Ac alpha 2-6lactose inhibited the binding to fetuin of both SSA and MSSA. Flow cytometric analysis showed that human histocytic lymphoma U937 cells were clearly stained with FITC-labeled MSSA (FITC-MSSA) without any detectable agglutination and that this staining was almost completely inhibited by the addition of Neu5Ac alpha 2-6lactose (2 mM). Treatment of U937 cells with native FITC-SSA at the sub-agglutinating concentration (0.3 microgram/ml) showed much poorer fluorescence intensity than that of MSSA, suggesting that MSSA is an invaluable tool for the detection of cell surface glycoconjugates containing NeuAc alpha 2-6Gal/GalNAc sequences by flow cytometry.


Subject(s)
Carbohydrates/analysis , Cell Membrane/chemistry , Lectins/isolation & purification , Carbohydrate Sequence , Cell Line , Chromatography, High Pressure Liquid , Electrophoresis, Polyacrylamide Gel , Flow Cytometry , Humans , Molecular Sequence Data , Plant Lectins , Plants , Ribosome Inactivating Proteins , alpha-Fetoproteins/pharmacology
11.
FEBS Lett ; 329(1-2): 75-8, 1993 Aug 23.
Article in English | MEDLINE | ID: mdl-8354412

ABSTRACT

Binding experiments using a 125I-labeled tyramine conjugate of N-acetylchitooctaose, a highly potent elicitor for the induction of phytoalexin production in rice cells, and a microsomal membrane preparation from suspension-cultured rice cells showed the presence of a novel high-affinity binding site for this oligosaccharide. The binding of the ligand was saturable and the Scatchard plot analysis of the results indicated the presence of a single class of binding site with a Kd of 5.4 nM which is comparable with that reported for the binding of the hepta-beta-glucoside elicitor in soybean membrane. The ligand binding was inhibited by unlabeled N-acetylchitoheptaose but not by its deacetylated form. These characteristics of this binding site coincide well with the specificity and sensitivity for the elicitor in several assay systems, suggesting the possible involvement of this binding site in the recognition of the elicitor in vivo.


Subject(s)
Oligosaccharides/metabolism , Oryza/metabolism , Binding Sites , Cell Membrane/metabolism , Cells, Cultured , Chromatography, High Pressure Liquid , Colorimetry , Molecular Structure , Oligosaccharides/chemistry , Spectrometry, Mass, Fast Atom Bombardment , Spectrophotometry, Ultraviolet , Tyramine/metabolism
12.
Neurology ; 28(8): 804-11, 1978 Aug.
Article in English | MEDLINE | ID: mdl-210423

ABSTRACT

We studied the effects of normal and myasthenic sera on the miniature endplate potential (MEPP) and resting membrane potential (RP) of rat muscle in vitro by conventional intracellular microelectrode techniques. Normal sera had little or no effect on either the amplitude or frequency of MEPP or RP. On the other hand, MEPP amplitude was reduced in each of nine muscles during exposure to myasthenic sera; five of these muscles showed a significant difference, by student's t-test, from the values in a control solution. The half decay time of diminished MEPP remained unchanged. MEPP frequency and RP were not affected by myasthenic sera. The reduced amplitude of the MEPP was almost completely restored when the muscle was washed with a control solution for more than 30 minutes. These observations indicate that myasthenic sera contain factors that bind reversibly with the acetylcholine receptor and reduce postsynaptic responses to acetylcholine.


Subject(s)
Myasthenia Gravis/immunology , Neuromuscular Junction/physiology , Synaptic Transmission , Adult , Animals , Female , Humans , In Vitro Techniques , Male , Membrane Potentials , Microelectrodes , Middle Aged , Myasthenia Gravis/blood , Rats , Receptors, Cholinergic/immunology
13.
Neuropharmacology ; 32(4): 377-85, 1993 Apr.
Article in English | MEDLINE | ID: mdl-7684515

ABSTRACT

Benzalkonium chloride (BA), a positively charged surface active agent, applied (> 10 nM) in the superfusing solution, produced a concentration-dependent reduction in the amplitude of both evoked endplate potentials (EPPs) and spontaneous miniature EPPs of the frog. Voltage-clamped endplate currents (EPCs) and spontaneous miniature endplate currents (MEPCs) were also diminished in amplitude, in the presence of BA (50-140 nM), whereas their time-course and reversal potential were not obviously affected. No significant change due to the addition of 50 nM BA was observed in apparent properties of the ACh channel estimated from ACh-induced current fluctuations. In the relationship between the amplitude of ACh potentials and the net charge for iontophoretic pulses at a single junction, the principal pattern of action of BA (30-60 nM) appeared to be a parallel shift to the right. At concentrations greater than about 1 microM, BA slightly increased the resting input conductance of the non-synaptic muscle fibre membrane. It was suggested that this increase was attributable to a slight increase in Cl ion conductance of the non-synaptic membrane. These results indicate that BA effectively blocked neuromuscular transmission, acting as an ACh receptor antagonist at smaller concentrations and as a more potent blocker that acts through multiple sites at greater concentrations.


Subject(s)
Benzalkonium Compounds/pharmacology , Neuromuscular Junction/drug effects , Acetylcholine/pharmacology , Animals , Depression, Chemical , Electric Stimulation , Evoked Potentials/drug effects , In Vitro Techniques , Ion Channels/drug effects , Membranes/drug effects , Motor Endplate/drug effects , Muscles/cytology , Muscles/innervation , Ranidae , Rats , Rats, Sprague-Dawley
14.
J Med Chem ; 38(15): 2964-8, 1995 Jul 21.
Article in English | MEDLINE | ID: mdl-7636857

ABSTRACT

(+/-)-(Z)-2-(Aminomethyl)-1-phenylcyclopropane-N,N-diethylcarbo xamide (milnacipran, 1), a clinically useful antidepressant, and its derivatives were prepared by an improved method and were evaluated as NMDA receptor antagonists. Of these, milnacipran (1), its N-methyl and N,N-dimethyl derivatives, 7 and 8, respectively, and its homologue 12 at the aminomethyl moiety had binding affinity for the receptor in vitro (IC50: 1, 6.3 +/- 0.3 microM; 7, 13 +/- 2.1 microM; 8, 88 +/- 1.4 microM; 12, 10 +/- 1.2 microM). These also protected mice from NMDA-induced lethality. These compounds would be important as anovel prototype for designing potent NMDA-receptor antagonists because of their characteristic structure, which clearly differentiated them from known competitive and noncompetitive antagonists to the receptor.


Subject(s)
Antidepressive Agents/chemical synthesis , Antidepressive Agents/pharmacology , Cyclopropanes/chemical synthesis , Cyclopropanes/pharmacology , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Animals , Antidepressive Agents/metabolism , Cyclopropanes/metabolism , Dizocilpine Maleate/metabolism , Kinetics , Male , Mice , Mice, Inbred Strains , Milnacipran , Radioligand Assay , Rats , Receptors, N-Methyl-D-Aspartate/metabolism , Structure-Activity Relationship , Tritium
15.
Am J Med Genet ; 34(4): 555-61, 1989 Dec.
Article in English | MEDLINE | ID: mdl-2576185

ABSTRACT

This study consisted of 1) molecular deletion analyses in patients with Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) using the entire cDNA for the DMD gene as hybridization probes, 2) RFLP analyses in a large number of Japanese normal women using 11 DMD-linked cloned DNAs as probes, and 3) segregation analyses with these RFLP data in 17 DMD families in which prenatal or carrier diagnosis was required. The deletion study showed that 18 (43%) of 42 male DMD patients had a deletion within the DMD gene, while no detectable deletion was found in 3 BMD patients. These deletions were preferentially observed at the 5' end of the DMD gene, while no deletion was found in the 3' portion of the gene. Of a total of 15 RFLPs detected with the 11 probes, one was a new RFLP (probe/enzyme: P20/MspI). In 6 RFLPs, the allele frequencies in the Japanese were statistically different from those in the Caucasian. Based on the RFLP data combined with the result of the deletion study, an estimated diagnostic rate for prenatal diagnosis and/or carrier detection in the Japanese DMD families was 63%. The real diagnostic rate obtained from the prenatal and carrier diagnoses, which were practically performed in 17 families, corresponded to the estimation. A protocol useful for the diagnosis in Japanese DMD families is presented.


Subject(s)
Chromosome Deletion , Genes , Muscular Dystrophies/genetics , Polymorphism, Restriction Fragment Length , Chromosome Mapping , DNA/genetics , DNA Mutational Analysis , Female , Fetal Diseases/diagnosis , Fetal Diseases/genetics , Genetic Carrier Screening , Humans , Japan , Male , Muscular Dystrophies/diagnosis , Pedigree , Pregnancy , Prenatal Diagnosis , X Chromosome
16.
J Biochem ; 112(1): 143-6, 1992 Jul.
Article in English | MEDLINE | ID: mdl-1429503

ABSTRACT

The interaction of Japanese elderberry bark lectin (Sambucus sieboldiana agglutinin, SSA) with carbohydrate was investigated by 1H-NMR. When a low affinity ligand, methyl beta-D-galactoside (beta MeGal), was mixed with SSA, each proton signal of beta MeGal was broadened. The signal of H-4 was markedly broad, while those of H-1, OCH3, and H-2 of beta MeGal were rather sharp. The specific broadening of Gal H-4 was more evident when SSA was mixed with methyl-beta-D-lactoside (beta MeLac). Position-dependent signal broadening suggests that beta MeGal binds to SSA such that H-4 is closely involved in the contact region, but H-1, OCH3, and H-2 are far from this region. In the case of a high affinity ligand, Neu5Ac(alpha 2-6)Gal(beta 1-4)Glc(= N6L), ligand signals of the SSA-N6L mixture did not change at all. But when a small amount of N6L was added to the SSA-beta MeGal mixture, the broad signals of bound beta MeGal became dramatically sharp. This indicates that the added N6L molecules liberated the bound beta MeGal from SSA. On the other hand, the sialyllactose with the alpha(2-3)-linkage(= N3L) could not substitute for bound beta MeGal because of its lower affinity. This demonstrates that the competitive binding experiment between two ligands is a useful technique to detect the interaction of lectins with high affinity ligands which could not be observed directly by NMR signal broadening and/or chemical shift change.


Subject(s)
Lectins/chemistry , Oligosaccharides/chemistry , Plant Lectins , Carbohydrate Sequence , G(M3) Ganglioside/analogs & derivatives , G(M3) Ganglioside/chemistry , Magnetic Resonance Spectroscopy , Methylgalactosides/chemistry , Methylglycosides/chemistry , Molecular Sequence Data , Ribosome Inactivating Proteins
17.
J Biochem ; 106(6): 1098-103, 1989 Dec.
Article in English | MEDLINE | ID: mdl-2628427

ABSTRACT

Three elderberry lectins isolated from the bark of three different species of the genus Sambucus which are native to Europe (S. nigra), North America (S. canadensis), and Japan (S. sieboldiana) were studied comparatively with regard to their carbohydrate binding properties and some structural features. All three lectins contained two identical carbohydrate binding sites per molecule and showed a very high specificity for the Neu5Ac(alpha 2-6)-Gal/GalNAc sequence. However, relative affinities for various oligosaccharides were significantly different among them, suggesting differences in the detailed structure of the carbohydrate binding sites of these lectins. The three lectins were immunologically related, but not identical, and all were composed of hydrophobic and hydrophilic subunit regions, although the molecular sizes of these subunits were slightly different among the three lectins. N-terminal sequence analysis of the subunits of these lectins suggested that they have a very similar structure in this region but also indicated the occurrence of N-terminal processing such as the deletion of several amino acid residues at the N-termini for both hydrophobic and hydrophilic subunits of all three lectins. Tryptic peptide mapping of the three lectins showed a similar pattern for all of them but also showed the presence of some unique peptides for each lectin.


Subject(s)
Lectins/metabolism , Amino Acid Sequence , Binding Sites , Carbohydrate Metabolism , Dialysis , Electrophoresis, Polyacrylamide Gel , Molecular Sequence Data , Molecular Structure , Peptide Mapping , Plant Lectins , Plants/metabolism , Ribosome Inactivating Proteins , Tritium , Trypsin/metabolism
18.
J Biotechnol ; 76(2-3): 227-32, 2000 Jan 21.
Article in English | MEDLINE | ID: mdl-10656337

ABSTRACT

In order to analyze intracellular signal transduction, we investigated the mechanism of chemical elicitor action by single-cell transient assay using green fluorescent protein (GFP) as a reporter gene. When the elicitor was applied from outside the cell into which the chitinase promoter and GFP reporter were introduced beforehand, fluorescence emission of GFP was observed. In contrast, when the elicitor was introduced in the cell to let the elicitor act from inside, no emission was observed. Addition of further elicitor from outside, however, did cause GFP emission. Therefore, it is clear that the elicitor does not act after entering the cell but that its signal is transduced into the cell via the cell membrane.


Subject(s)
Chitinases/genetics , Molecular Biology/methods , Oligosaccharides/pharmacology , Oryza/drug effects , Oryza/metabolism , Cells, Cultured , Chitinases/drug effects , Chitinases/metabolism , Gene Expression Regulation, Plant , Genes, Reporter , Green Fluorescent Proteins , Luminescent Proteins/analysis , Luminescent Proteins/genetics , Luminescent Proteins/metabolism , Microscopy, Fluorescence/methods , Oryza/cytology , Oryza/genetics , Promoter Regions, Genetic , Recombinant Proteins/analysis , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Signal Transduction
19.
J Neurol Sci ; 51(1): 69-79, 1981 Jul.
Article in English | MEDLINE | ID: mdl-7252521

ABSTRACT

Ambenonium chloride was administered orally in a dosage of 6 mg/kg/day to rats for 14-360 days. Motor end-plate fine structure and junctional AChR were quantitatively analyzed and red (soleus) and white (EDL) muscle fibers. In treated animals, degeneration and simplification of postsynaptic folds and widening of synaptic clefts were often observed in soleus end-plates, but infrequently in EDL end-plates. On the other hand, the postsynaptic AChR was reduced markedly in both soleus and EDL end-plates. No presynaptic changes were observed. These results show that long-term administration of Anti-ChE agents in myasthenia gravis may have an adverse effect on neuromuscular transmission.


Subject(s)
Ambenonium Chloride/adverse effects , Motor Endplate/drug effects , Neuromuscular Junction/drug effects , Receptors, Cholinergic/drug effects , Animals , Female , Motor Endplate/analysis , Motor Endplate/ultrastructure , Myasthenia Gravis/drug therapy , Rats , Receptors, Cholinergic/analysis
20.
Phytochemistry ; 48(1): 49-54, 1998 May.
Article in English | MEDLINE | ID: mdl-9621452

ABSTRACT

A large portion of beta-glucosidase (EC 3.2.1.21) in germinating rice seeds, which appears to be ionically bound to cell walls, can be solubilized with 1 M NaCl. Its activity increased more than eight-fold within five days of germination. It was purified to electrophoretic homogeneity from the extracts of germinated rice seeds by fractionation with (NH4)2SO4 followed by CM-Sepharose, Polybuffer exchanger 118, Concanavalin A-Sepharose and Bio-Gel P-100. The Mr of the purified enzyme, estimated by SDS-PAGE, was 56,000 and the isoelectric point was > 10.0. Its N-terminal amino acid sequence (44 residues) exhibited high homology to those of beta-glucosidases from other plants, such as barley and white clover. Its activity was optimal at pH 4.5 and 50 degrees, and it was strongly inhibited by glucono-1,5-lactone. The enzyme showed hydrolytic as well as transglycosylation activity towards (1-->3)-beta- and (1-->4)-beta-linked oligosaccharides with degree of polymerization of 2-4. The results suggest that the beta-glucosidase is probably involved not only in hydrolysis but also in modification of oligosaccharides in cell walls of germinating rice seeds.


Subject(s)
Cell Wall/enzymology , Oryza/enzymology , beta-Glucosidase/isolation & purification , Amino Acid Sequence , Chromatography, Affinity , Chromatography, Gel , Electrophoresis, Polyacrylamide Gel , Molecular Sequence Data , Sequence Homology, Amino Acid , Substrate Specificity , beta-Glucosidase/antagonists & inhibitors , beta-Glucosidase/metabolism
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