[Immunoglobulin producing mechanism and their abnormalities].
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Antigens, CD↗
Biomedical subjects
T Hamano
Publications and source records attributed to T Hamano.
Triggering of calcium signals in antigen-specific B-cells on the supported lipid monolayers.
Using supported lipid monolayers we have studied here calcium signals in antigen-specific B-cells (TNP-specific B-cell hybridomas, TP67.21) triggered by lipid hapten (TNP-Cap-DPPE). Stimulation of the B-cell hybridomas (TP67.21) with a supported DPPC monolayers containing 1% TNP-Cap-DPPE increased the intracellular free calcium ion concentration [Ca2+]i in B-cells. None of B-cells responded to a DPPC monolayers without lipid hapten (TNF-Cap-DPPE). Triggering for calcium signals was clearly dependent on the fluidity of the lipid monolayers. Solid DPPC and DSPC monolayers triggered the calcium signals more efficiently than the fluid DMPC monolayers did. These calcium signals became apparently more efficient in the presence of cholesterol. All of these results suggested that the rigidity of cross-linking for antigen receptors (mIgM) may be a crucial role for triggering calcium signals in B-cells.
1,2-Dipalmitoylphosphatidylcholine↗
Confocal fluorescence microscopy for studying thapsigargin-induced bivalent-cation entry into B cells.
We studied thapsigargin-induced bivalent-cation entry into antigen-specific B cells (TP67.21) with a confocal fluorescence microscope. Confocal fluorescence images of fluo-3-loaded B cells showed that thapsigargin-stimulated Ca2+ signals were transferred not only to the cytoplasm but also to the nucleus. In the absence of external Ca2+ ions, the free Ca2+ concentrations both in the cytosol and in the nucleus declined to basal levels by 5 min after addition of thapsigargin. However, subsequent addition of Ca2+ in the external medium made the fluo-3 (fura-2) fluorescence intensity rise, reflecting the fact that Ca2+ accumulated again in the nucleus as well as in the cytoplasm. Then, we added Ba2+ and Mn2+ instead of Ca2+, because Ba2+ and Mn2+ are known to enter via Ca2+ channels. The addition of Ba2+ and Mn2+ in the external medium quenched the fluo-3 fluorescence both in the nucleus and in the cytoplasm of B cells. This suggested the possibility that the increase in intranuclear Ca2+ after thapsigargin stimulation may come from the cytoplasm, not from the nuclear stores.
Aniline Compounds↗
Prevalence of dry eye in Japanese eye centers.
BACKGROUND: The purpose of the investigation was to ascertain the prevalence of dry eye in new outpatients. METHODS: A total of 2127 consecutive new outpatients seen in eight Japanese centers from April 1992 to January 1993 underwent comprehensive examinations, including double vital staining and measurement of tear film break-up time, basal tear secretion, and tear clearance. Dry eye was diagnosed if patients had abnormalities of both the tear film and the ocular surface. RESULTS: Three hundred fifty-nine patients (17%) had dry eye. There was no seasonal pattern for dry eye. The condition was significantly more common in Tokyo than in suburban areas (P < 0.01). The prevalence of dry eye in visual display terminal (VDT) users and contact lens (CL) wearers was significantly higher than in non-VDT users and non-CL wearers (P < 0.05 and P < 0.02, respectively). CONCLUSION: Our findings suggest that dry eye is one of the most common ocular disorders encountered by physicians. Furthermore, if patients use VDTs or wear CLs, the likelihood of dry eye occurring is higher.
Adolescent↗
Movement-related potentials associated with bilateral simultaneous and unilateral movements recorded from human supplementary motor area.
To clarify the differences of movement-related potentials (MRPs) among ipsilateral, contralateral and simultaneous bilateral movements, MRPs with finger, thumb or foot movements were recorded from subdural electrodes chronically implanted on the supplementary motor area (SMA) in 3 patients, and also from the primary sensorimotor area in two of them being evaluated for epilepsy surgery. As a result: (1) SMA generated clear pre-movement potentials regardless of the type of movement. Its amplitude was almost identical between contralateral and bilateral movements except for the motor potential (MP). The pre-movement potentials associated with ipsilateral movements were relatively smaller than those with contralateral or bilateral movements. (2) The primary sensorimotor area generated clear pre-movement potentials in contralateral and bilateral movements with similar amplitude. With ipsilateral hand movements, however, only a small Bereitschaftspotential (BP) and no negative slope (NS') or MP was seen, and ipsilateral foot movements were not preceded by any BP. It is, therefore, most likely that, as far as the preparation for simple voluntary self-paced movement is concerned, the SMA plays an equally important role in unilateral and bilateral movements, whereas the primary sensorimotor area is involved predominantly in the preparation of contralateral movements.
Adult↗
Enzymic method for the amperometric determination of nicotinic acid in meat products.
An enzymic method for the determination of nicotinic acid is described, based on the indirect electrochemical monitoring of nicotinic acid via its reaction with oxygen in the presence of nicotinic acid hydroxylase. Derivative amperometric signals due to oxygen depletion enable a one-point kinetic analysis to be carried out. Nicotinic acid hydroxylase catalyses the hydroxylation of nicotinic acid to produce 6-hydroxynicotinic acid, which is accompanied by a stoichiometric consumption of oxygen. The method was applied successfully to the analysis of real samples.
Catalysis↗
Observation of precorneal tear film in patients with Sjögren's syndrome.
The present study was designed to examine whether the lipid layer of the precorneal tear film has a role in the pathogenesis of dry eye. The study involved 104 eyes of 52 patients with primary Sjögren's syndrome. The lipid layer of the precorneal tear film was observed by non-contact specular microscopy, and relationships between grade of interference color and the tear function parameters were examined. The lipid layer was classified from Grade 1, with no interference color, to Grade 4, of most intense interference color. In addition to these four grades, an oil droplet type not previously described was characterized. The grade of interference color was closely related to the intensity of vital staining. The oil droplet type was associated with more severe ocular surface damage than were Grades 1 through 4. The findings of this study suggest that the state of the lipid layer of the tear film may have some involvement in the pathogenesis of dry eye.
Adult↗
Artificial cell-spreading of permeabilized BHK cells on fibronectin-coated substratum.
We developed a cell-spreading model of permeabilized BHK cells to analyze molecular interactions in the cell-spreading machinery. BHK cells in suspension were allowed to attach onto the fibronectin-coated cover slips at 37 degrees C for 20 min. The cells were then permeabilized with 50 micrograms/ml saponin for 10 min at 4 degrees C. Approximately 50 percent of the cell models spread in response to exogenous 1 mM ATP for 90 min at 37 degrees C. Anti-actin antibody penetrated into almost all the cell models which spread ATP-dependently. These indicate that half number of the cell models permeabilized with saponin is spread by the exogenous ATP and has pores larger than an IgG molecule.
Adenosine Triphosphate↗
[Neuron specific enolase-producing IgD multiple myeloma with high serum amylase activity].
A 68-year-old man who was admitted to our hospital because of general fatigue and anorexia. He was diagnosed as suffering from neuron specific enolase (NSE)-producing IgD-lambda type multiple myeloma with high activity of serum amylase, based on the detection of monoclonal IgD-lambda M-protein in the serum and urine, markedly high activities of salivary-type amylase and NSE in the serum, and immunohistochemical evidence of NSE and IgD in the myeloma cells. After two courses of alpha-IFN and VMCP chemotherapy, serum IgD, amylase and NSE decreased to normal levels. These observations indicate that NSE was ectopically produced by myeloma cells.
Aged↗
Tunicamycin inhibits prostaglandin F2 alpha receptor-mediated phosphoinositide hydrolysis in cultured rat astrocytes.
Effect of tunicamycin, an inhibitor of N-linked glycosylation, on prostaglandin (PG) F2 alpha-stimulated phosphoinositide (PI) hydrolysis was examined in cultured rat astrocytes. Pretreatment of cultured astrocytes with tunicamycin (25-250 ng/ml) inhibited subsequent PGF2 alpha (1 microM)-stimulated PI-hydrolysis in concentration- and time-dependent manners. The inhibition completely recovered after removal of tunicamycin and re-incubation for 12 h. Tunicamycin pretreatment (100 ng/ml for 12 h) significantly blocked [35S]methionine incorporation into cultured astrocytes, but cell viability was not affected under the condition. Inhibitors of processing of N-linked sugar chains such as bromoconduritol, 1-deoxymannojirimycin, and swainsonine had no effect on PI response to PGF2 alpha. These observations suggest that PGF2 alpha receptor is N-linked glycosylated.
Animals↗
Characterization of a functional null cell line derived from NZB x NZW)F1 mice.
We attempted to establish a null cell line from NZB x NZW(B/W)F1 mice in order to investigate a regulatory role of null cells during polyclonal B cell activation in autoimmune diseases. NB2.2, a representative subclone of resulting null cell lines, was maintained in long-term tissue culture with 10% mouse ConA supernatant (MCAS). Interestingly, the cell free supernatant of the NB2.2 cells (NB-CFS) showed marked synergistic effects on IgM secretion by B cells induced by IL-5. In addition, NB-CFS had the ability to augment the production of autoantibodies against bromelain-treated mouse red blood cells (BrMRBC) and single-stranded DNA (ssDNA) by B cells induced by IL-5. To determine whether NB2.2 cells induce polyclonal B cell activation and autoantibody generation in vivo, BALB/c mice were injected with NB2.2 cells. The results showed that the level of anti-ssDNA antibodies in sera of BALB/c mice injected with NB2.2 cells was significantly higher than that of control BALB/c mice injected with FDC-P2 cells. In addition, splenic B cells from mice injected with NB2.2 cells significantly proliferated in vitro in response to IL-4 and IL-5, and produced anti-ssDNA antibodies in the presence of IL-5. These results suggest that NB2.2, a null cell line established from B/WF1 mice, produces mediators capable of promoting polyclonal B cell activation and inducing autoantibody secretion, and that this kind of null cell may play an important role in the pathogenesis of autoimmune diseases.
Animals↗
Ocular surface damage and tear lactoferrin in dry eye syndrome.
We studied the relationship between the severity of ocular surface damage and the level of tear lactoferrin in primary and secondary Sjögren's syndrome and keratoconjunctivitis sicca not associated with Sjögren's syndrome. A significant negative correlation was found between Rose Bengal staining score and level of tear lactoferrin in all three groups. Analysis of covariance disclosed no significant differences in regression lines for Rose Bengal staining score vs tear lactoferrin level among the three groups. The three regression lines appeared to be identical to each other. These findings indicate that the severity of ocular surface damage due to dry eye largely depends on the tear secretory function of the lacrimal gland, and that the function of the lacrimal gland can be evaluated by determination of level of tear lactoferrin using the same standards regardless of differences in pathogenesis of underlying diseases.
Adolescent↗
Optimisation of botulinum treatment for cervical and axial dystonias: experience with a Japanese type A toxin.
Twenty two patients with cervical and axial dystonias were treated with Japanese type A botulinum toxin. Injections were given repeatedly at intervals of 28-30 days to carefully chosen muscles with increased activities, with a maximum dose per session of 300 units. The maximum improvements in subjective and objective ratings were obtained only after repeated injections. No anti-toxin antibodies were detected; nor did any muscle fail to respond to the toxin. During the treatment, previously "silent" muscles were activated to reproduce the original abnormal posture, as if driven by a central motor programme. This resistance to treatment was overcome by injecting the toxin into newly activated muscles. Repeated injections are thus required to override central mechanisms in dystonias or to maximise drug delivery to large muscles. Antibody development may be controlled by the use of a less immunogenic toxin.
Adolescent↗
A case of pulmonary amyloidosis associated with multiple myeloma successfully treated with dimethyl sulfoxide.
A 57-year-old man with IgG multiple myeloma developed pulmonary infiltration caused by pulmonary amyloidosis, for which continuous transdermal dimethyl sulfoxide (DMSO) treatment was given. After 8 weeks from the start of DMSO treatment, a dramatic reduction of pulmonary infiltration as determined by chest roentgenogram was observed, and arterial blood gas levels were improved. No serious side effect of DMSO was encountered. We conclude that a therapeutic trial with transdermal DMSO administration brought about a marked regression of the pulmonary infiltrate.
Administration, Cutaneous↗
[A case of systemic lupus erythematosus (SLE) successfully treated with mizoribine (Bredinin)].
Mizoribine, a novel immunosuppressive agent developed in Japan, was administered as a monotherapy to a systemic lupus erythematosus (SLE) patient with the clinical symptoms and immunological abnormalities accompanying SLE showing marked improvement. The result of prolonged administration over 22 months in this case showed neither relapse nor side-effects. Reports have been made about mizoribine used concomitantly with steroids in the treatment of SLE; however, there have not been any reports of mizoribine as a monotherapy for SLE being effective. In this case, mizoribine (150 mg/day) was administered without steroids as a monotherapy on a outpatient basis since the patient's condition overall was relatively good and the serious complications of the heart, kidneys, and lungs that accompany SLE were not observed. The results of this treatment showed improvements in alopecia, arthritis, and systemic malaise from about the 4th week after the start of administration, and the clinical symptoms that accompany SLE had completely disappeared in the 8th week. Also, the immunological tests markedly improved. Four months after the start of administration the immunological abnormalities in the anti-DNA antibody, rheumatoid factor, and immune complex were completely corrected. This case showed dramatic improvement in the SLE clinical symptoms and immunological abnormalities with the mizoribine monotherapy as well as the potential for mizoribine monotherapy to maintain a state of remission over the long term.
Anti-Inflammatory Agents, Non-Steroidal↗
A study of the complications induced by conventional and disposable contact lenses.
We reviewed the charts of 23,068 patients (45,580 eyes) who were prescribed contact lenses in order to investigate the incidence of corneal complications in Japan. This population of patients included wearers of various types of conventional contact lenses as well as disposable extended wear lenses and daily disposable lenses. The rate of corneal complications and 95% confidence interval for each lens group were: polymethylmethacrylate (PMMA) lenses, 15.8% (358 of 2,267 eyes, 14.3-17.3%); rigid gas permeable lenses, 10.5% (3,191 of 30,459 eyes, 10.2-10.8%); acrylelastomer lenses, 7.2% (nine of 124 eyes, 2.7-11.7%); HEMA lenses 8.5% (534 of 6,261 eyes, 7.8-9.2%); high water content lenses, 4.0% (103 of 2,591 eyes, 3.6-4.4%); weekly disposable lenses, 4.9% (146 of 2,985 eyes, 4.1-5.7%); and daily disposable lenses, 2.5% (22 of 893 eyes, 1.5-3.5%). PMMA lenses had a significantly higher rate of corneal complications compared with other lenses, whereas the daily disposable lens had a significantly lower rate for the same. The majority of corneal complications for all types of lenses consisted of superficial punctate keratopathy, and there were no cases of corneal ulcers.
Adolescent↗
Lack of prolonged cerebral blood flow change after transcranial magnetic stimulation.
To study the physiological changes in the human brain induced by transcranial magnetic stimulation (TMS), we measured cerebral blood flow (CBF) before and after TMS in 3 healthy volunteers with positron emission tomography (PET). The intersecting point of the figure-of-eight coil was positioned at C3. TMS was delivered 20-32 times at maximum intensity. CBF measured at 50 sec after the termination of TMS showed no significant change in the cerebral cortex corresponding to C3 or any other area. This finding indicates that the hemodynamic change in the brain induced by TMS, if any, lasts only for a short period.
Adult↗
Vibration-evoked sensory nerve action potentials derived from Pacinian corpuscles.
To evaluate sensory response to natural stimuli, we developed a method to record sensory nerve action potentials evoked by high-frequency vibratory stimulation. Trains of 250 Hz sinusoidal indentations with a duration of 100 msec were applied to the finger tip at a rate of 3 Hz. The responses were obtained with surface electrodes placed over the median and ulnar nerves at the wrist. Averaged wave forms consisted of two components: an initial diphasic or triphasic potential and the following low amplitude trains of discharges phase-locked to vibratory stimuli. Anesthesia of the skin at the stimulation site or tourniquet-induced ischemia of the limb eventually diminished both components. Neither of them therefore represented artifacts from electrode movement or electromagnetic field intrinsic to the stimulator. Various kinds of mechanoreceptors may contribute to the first component. Pacinian corpuscles probably give rise to the second component as the only skin receptors that can respond to high-frequency vibratory stimuli of 250 Hz. This method helps examine neural coding of the receptor and the peripheral nerve fiber mediating vibration sense.
Action Potentials↗