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Biomedical subjects

H Miyahara

Publications and source records attributed to H Miyahara.

At least 55 records · Page 3Linked to original sources
PubMed1995

Histochemical differences of the lectin affinities of backbone polylactosamine structures carrying the ABO blood group antigens in papillary carcinoma and other types of thyroid neoplasm.

Endo-beta-galactosidase from Escherichia freundii cleaves linear polylactosamine structure as follows: R-GlcNAc-beta 1-3Gal-beta 1-4GlcNAc-beta 1-R' + H2O-->R-GlcNAc-beta 1-3Gal + GlcNAc-beta 1-R'. Staining with Griffonia simplicifolia agglutinin II (GSA-II) following enzyme digestion reveals the distribution of R-GlcNac-beta 1-3Gal-beta 1-4GlcNAc-beta 1-R' structures in tissue sections. In this study, the procedure was applied to formalin-fixed, paraffin-embedded tissue sections from 26 cases of papillary carcinomas including 2 follicular variants, 8 follicular carcinomas, 7 adenomas, 1 anaplastic carcinoma and 1 medullary carcinoma in order to investigate whether different types of polyactosamine-containing structure are produced in these thyroid neoplasms. Simultaneously, the susceptibility of the ABH antigens expressed in these neoplastic cells to endo-beta-galactosidase digestion was examined. Most of the papillary carcinoma cells from all the individuals examined were strongly stained by GSA-II following enzyme digestion. Without enzyme digestion, little or no reactivity with GSA-II was observed. Among other types of neoplasms, only one case of follicular carcinoma exhibited reactivity with GSA-II following enzyme digestion. ABH antigens were expressed in 22 cases of papillary carcinomas, 2 adenomas, 5 follicular carcinomas and 1 anaplastic carcinoma, and their expression was dependent on the ABO blood group of the patients. Endo-beta-galactosidase digestion resulted in the elimination of these antigens not only in papillary carcinomas but also in other neoplasms.(ABSTRACT TRUNCATED AT 250 WORDS)

ABO Blood-Group System↗
PubMed1995

Effects of cyclosporin on serum hyaluronan levels in collagen arthritis.

Serum hyaluronan (HA) levels were measured in a rat model of collagen arthritis using a sandwich enzyme-linked immunosorbent assay. Values became elevated as the arthritis developed, correlating with its severity. Daily subcutaneous treatment with cyclosporin at the dose of 25 mg/kg per day for fourteen days completely prevented anti-type II collagen antibody production and the serum HA increase as well as development of collagen arthritis. HA in the blood may thus provide a good quantitative marker for joint disease in rat collagen arthritis with potential as a tool for evaluation of drug efficacy in this experimental model.

Animals↗
PubMed1995

Role of glucocorticoid in vestibular compensation in relation to activation of vestibular nucleus neurons.

It is still not established whether or not glucocorticoids are effective in the treatment of vestibular disorders such as dizziness and imbalance, although these drugs in combination with several others are used to treat dizziness and imbalance in some diseases. This study was undertaken to investigate the effects of a glucocorticoid, dexamethasone, on vestibular disorder following unilateral labyrinthectomy in pigmented rabbits. Neuronal activities of the medial vestibular nucleus (MVN) in alpha-chloralose-anesthetized cats were also investigated. Systemic injection of dexamethasone decreased the frequency of nystagmus and head deviation dose-dependently following hemilabyrinthectomy, and the rate of decrease was faster than that obtained by saline. In contrast, RU38486 (a glucocorticoid receptor antagonist) delayed the reduction of nystagmus and head deviation. Micro-iontophoretic application of dexamethasone rapidly enhanced the spontaneous firing of MVN neurons in a dose-dependent manner. These increases were blocked by RU38486, but not by GDEE (a glutamate receptor antagonist) or Co2+ (a Ca2+ channel blocker). These results suggest that dexamethasone directly activates the MVN neurons, thereby accelerating vestibular compensation.

Adaptation, Physiological↗
PubMed1995

Clinical application of ultrasonic blood rheography in vertebral artery for vertigo.

In 507 vertigo cases in which circulatory velocity in the vertebral artery was determined, using ultrasonic blood rheography, the results in 150 cases (32%) were abnormal, falling appropriately into a 'laterality' group and a 'lower' group. Twenty-one patients whose clinical course was followed up showed a decrease in the side difference of their circulatory velocity, with consequent improvement in their vertigo. VBI demonstrated a poorer prognosis for the laterality group than for the normals, thus indicating a positive correlation between side difference and the effect of fluctuating blood pressure on serum lipids. Certain antivertiginous drugs had a beneficial effect on side difference, increasing the circulatory velocity.

Adolescent↗
PubMed1995

ABR findings in brainstem ischemia: occlusion of the left anterior inferior cerebellar artery.

ABR was measured ipsilaterally following permanent left anterior inferior cerebellar artery (AICA) occlusion to assess the discrepancy in recovery between blood flow and function in the rat brainstem. Three types of wave patterns were classified: in type 1, all components disappeared: in type 2, all components disappeared transiently, then re-appeared; and in type 3, only a significant increase in the latency difference between components I-IV was noted. In type 2, we suggest that all components re-appeared because cochlear blood flow was re-established quickly by collateral circulation.

Animals↗
PubMed1995

Clinical application of ultrasonic blood rheography for vertigo.

The blood flow in the vertebral artery was measured in 507 patients with vertigo using ultrasonic blood rheography. In 150 of the 507 cases (32%), abnormal findings including laterality and decreased flow were detected. Twenty-one cases whose clinical course was observed showed a decrease in the differences in velocity between sides as vertigo improved. VBI (vertebro-basilar insufficiency) showed a worse prognosis in patients with laterality compared with those without and a positive correlation was demonstrated between side differences and fluctuating blood pressure or serum lipids. Some anti-vertiginous drugs improved the difference between sides by increasing the velocity.

Adolescent↗
PubMed1995

[Evaluation of blood-group-related carbohydrate antigens in thyroid neoplasms].

An immunohistochemical study using a panel of monoclonal antibodies (mAbs) against blood group A, B, H and Lewis antigens Le(a), Le(b), Le(x) and Le(y) and lectins, such as PNA, VVA-B4 and UEA -1, was carried out to investigate the aberrant expression of carbohydrate antigens in formalin-fixed, paraffin-embedded tissue sections of thyroid neoplasms. The tissues examined consisted of 26 papillary carcinomas, seven follicular adenomas, seven follicular carcinomas, one anaplastic carcinoma and one medullary carcinoma. MAbs against A, B and H antigens reacted strongly with papillary carcinomas from most of the individuals studied (22 of 26 individuals) and their reactivity corresponded well to the blood groups of individuals. In follicular adenomas and carcinomas, these mAbs reacted weakly with a small number of neoplastic cells from two of seven, and four of seven individuals, respectively. Positive staining with mAbs against Le(a) and Le(b) antigens was found in almost all papillary carcinomas. On the contrary, these mAbs rarely reacted with cells from follicular adenomas and carcinomas. T and Tn antigens which were recognized by PNA and VVA-B4, respectively, were only weakly expressed in a limited number of cells from the thyroid neoplasms. Normal cells adjacent to malignant cells were not stained by any of the stains used in this study. These results are discussed in light of our recent findings that polylactosamine structures produced in papillary carcinomas are quite different from those expressed in other types of neoplasms.

Adenocarcinoma, Follicular↗
PubMed1995

Collagen-induced arthritis in B10.RIII mice (H-2r): identification of an arthritogenic T-cell determinant.

Susceptibility to collagen-induced arthritis (CIA), a murine model of autoimmune arthritis, is strongly linked to only two major histocompatibility complex (MHC) haplotypes, H-2q and H-2r. In order to identify the determinants of type II collagen (CII) required to induce arthritis in H-2r-bearing mice, B10.RIII mice were immunized with bovine, chick or human CII. Only bovine CII induced significant arthritis and autoantibodies. When the major CNBr peptides of bovine collagen were isolated and used for immunization, only mice immunized with CB8, representing CII 403-551, developed arthritis. To identify immunogenic epitope(s) within CB8, a panel of synthetic peptides representing overlapping sequences of the bovine peptide was generated. When each peptide was cultured with T cells from B10.RIII mice immunized with CII, one peptide, representing CII 430-466, contained a major T-cell epitope. By using an in vitro lymphokine production assay, the T-cell epitope was further narrowed to CII 442-456. These findings suggest that a T-cell determinant important for the initiation of arthritis in B10.RIII (H-2r) mice is located within a 15 amino acid sequence, residues 442-456 of bovine CII.

Amino Acid Sequence↗
PubMed1995

Identification and characterization of a major tolerogenic T-cell epitope of type II collagen that suppresses arthritis in B10.RIII mice.

Tolerization of B10.RIII mice (H-2r) with intravenously injected type II collagen (CII) renders the animals resistant to induction of collagen-induced arthritis (CIA). In order to clarify H-2r-restricted T-cell responses that modulate CIA, we have analysed the T-cell proliferative response of B10.RIII mice against cyanogen bromide (CB) peptides of CII, and detected the strongest response to alpha 1(II)-CB10 (CII 552-897). A panel of chemically synthesized overlapping peptide homologues was used to deduce the minimum structure of this determinant which was found to be CII 610-618. A 15-residue synthetic peptide flanking this region, CII 607-621, was found to effectively suppress arthritis when administered as a tolerogen. Collectively, these data identify the structural component within alpha 1(II)-CB10 which is capable of inducing tolerance in B10.RIII mice. A similar approach to the treatment of autoimmune arthritis, involving the institution of self-tolerance, has potential applicability to human rheumatoid arthritis.

Amino Acid Sequence↗
PubMed1995

Model of rate-dependent property in myocardial tissues as a useful algorithm for the PC-based arrhythmia generator.

Two mathematical models were presented as an arrhythmia generator. One was the so-called modulated parasystole model. The other was a model of the rate-dependent property of atrioventricular nodal conduction represented by the atrioventricular recovery curve (AVRC). Both models were mathematically formulated as a nonlinear first-order difference equation, and implemented on a personal computer (PC) as an arrhythmia simulator. It was utilized for evaluating the diagnostic performance of computerized ECG analyzers.

Algorithms↗
PubMed1995

Computer-assisted instruction of arrhythmia for MS-windows.

1. INTRODUCTION. Training in the diagnosis of arrhythmias is an important part of the curriculum for medical students, postgraduates, and paramedical staff. Although several CAI for arrhythmia have been developed [1-3], we could not get CAI software for arrhythmia for the MS-Windows environment. In this report, we present a newly-developed computer-assisted reference system for arrhythmia that functions in the Windows environment. 2. DESCRIPTION OF THE SYSTEM. The system consists of a program and two data files. An MS-Windows program (ECG9405.EXE, 180kB) was compiled using Borland's C++ v.3.1. A binary file (ECPAT.BAS 33kB) includes data of normal and abnormal wave segments of ECG: P wave, PQ interval segment, and QRs complex with/without T wave. A mother file (ECG9405.sys, 57kB) includes 85 data sets to generate ECG waveforms of arrhythmia. Each data set contains a sequence of wave form numbers, the text for questions and answers, and the commands strings. There are five major commands: 1) to create a new window as "wave window"; 2) to make electrocardiogram data; 3) to plot the data on the window; 4) to create a "dialog box" for questions and explanations; and 5) to check the answers. he program gets a data set from the data according to the user's choice. The program then interprets the data set and executes the commands. The wave segment data are plotted in a "wave window" at every 10 milliseconds; this is controlled by the MS-Windows' timer. The timer interval can be changed by selecting the speed button. The ECG waveforms are displayed on a window just like an ordinary ECG monitor with beat sound. Many windows can be created by the user and many ECG waves simultaneously plotted on CRT. 3. USAGE OF THE SYSTEM. The "main window" has a menu that has three items corresponding to the training course: BASIC, TRY, and TEST. Thirty-five types of arrythmias are listed in the "list box" of the windows in BASIC course e.g., sinus arrhythmia, atrial flutter, atrial premature contraction, ventricular extrasystole, ventricular flutter, etc. If the user selects one of them on the list by double clicking, some textual explanations of the wave are described in a dialog box. Ten multiple choice questions are displayed in the dialog box in course of learning TRY and TEST; the answers to these are requested. In the TEST course, the system offers random access to each arrhythmia. he user can send the pictorial ECG data in the window to other graphics programs through a clip board. 4. DISCUSSION. It was successfully used in a lecture of electrocardiogram for medical students. They seem to be interested in this system because of its simple usage and the dynamic drawing of ECG waves on CRT. Multiple computer-based medical resources can be run on MS-Windows. The system is able to run simultaneously with other programs, such as an electronic reference system [4]. The system may be obtained from the authors upon request.

Arrhythmias, Cardiac↗
PubMed1994

Expression of the estrogen receptor in human thyroid neoplasms.

The expression and quantitation of the estrogen receptor (ER) in human thyroid tumors were examined by biochemical, immunohistochemical, and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques. For this study, neoplasms, adenomatous goiters and adjacent normal thyroid tissues were obtained from 35 patients which included 10 cases of papillary carcinomas, 17 cases of adenomas and 8 cases of adenomatous goiters. Regardless of the histopathological subtype, ER was detected in 19% (5/27) of the neoplastic tissues with the mean value of ER content of 5.0 +/- 1.3 fmol/mg protein and the mean Kd value of 0.38 +/- 0.28 nM. ER was also detected, but at a lower concentration (2.8 +/- 1.6 fmol/mg protein), in the surrounding normal tissues. There was no significant difference between the neoplasms and adenomatous goiters with respect to the incidence of ER positivity and ER content. Furthermore, ER-positive specimens, as determined by both biochemical and immunohistochemical techniques, also showed the expression of ER mRNA detected by RT-PCR method. These results demonstrate that both ER mRNA as well as ER protein are expressed in thyroid neoplasms. This suggests the possibility that estrogen may affect the tumorigenesis or the progression of some thyroid neoplasms.

Adenoma↗
PubMed1994

Legg-Calvé-Perthes' disease in the Russell-Silver syndrome. A report of two cases and a review of the literature.

Perthes' disease was seen in two boys, aged 6 1/2, with the Russell-Silver Syndrome. Both presented with groin or thigh pain in their shortened side together with a progressive limp. They were treated conservatively, and when reviewed 6 1/2 years after diagnosis the lesions of the hip had improved clinically and radiographically. The leg length discrepancy did not increase.

Abnormalities, Multiple↗
PubMed1994

Autoradiographic measurement of regional brainstem blood flow: occlusion of the anterior inferior cerebellar artery.

Autoradiography was used to measure regional brainstem blood flow in Wistar rats following permanent left anterior inferior cerebellar artery (AICA) occlusion. With the AICA occluded, blood flow to the left vestibular nucleus decreased 31% while flow to the left cochlear nucleus decreased 47% when compared to the right (unobstructed) side. In the rat, the median pontine branch of the basilar artery was found to provide the principal blood supply to the vestibular nucleus. Electrocochleography was also used to measure the action potential (AP), summating potential (SP) and cochlear microphonics (CM) during left AICA occlusion. The AP disappeared completely after at least 7 min, while the SP polarity changed from negative to positive. Findings also showed that CM2 did not disappear completely in pre-mortem animals.

Action Potentials↗
PubMed1994

Tissue transmigration of CZON (Cosmosin) to middle ear mucosa, maxillary sinus mucosa, and palatine tonsils.

The concentration of CZON was determined by HPLC in surgical patients with chronic otitis media, sinusitis, and tonsillitis. One gram of CZON was injected intravenously prior to surgery. The time course of the mean tissue CZON level was as follows: In the middle ear mucosa, 3.7 micrograms/g at 15 min, 7.2 micrograms/g at 30 min, and 2.9 micrograms/g at 1 hr (the half life: 21.3 min). In the maxillary sinus mucosa, 10.5 micrograms/g at 15 min, 11.8 micrograms/g at 30 min, and 2.8 micrograms/g at 1 hr (the half life: 17.5 min). In the tonsils, 14.9 micrograms/g at 15 min, 9.3 micrograms/g at 30 min, and 2.0 micrograms/g at 1 hr (the half life: 13.2 min). The concentration was high in the maxillary sinus mucosa and the tonsils, but was low in the middle ear mucosa. In the formers the transfer ratio reached its peak 15 to 30 min after administration, but in the latter the peak was reached 30 to 60 min after administration. The order of the transfer ratio at each region was above 25%. The tissue concentration exceeded the MIC80s of frequent isolates from these infections. CZON is considered to be a highly useful drug in the treatment of these infections.

Adolescent↗
PubMed1994

High-density proteoglycan induces specific suppression of adjuvant-induced arthritis in rats.

In vitro data support the view that T cells in adjuvant-induced arthritis (AIA) respond to the proteoglycan (PG) component of articular cartilage; however, an in vivo role for PG in AIA has yet to be shown. To do so, we examined the effects of pretreatment with bovine cartilage high density PG (HDPG) on AIA induced by heat-killed Mycobacterium butyricum in Lewis rats. Purified bovine cartilage HDPG emulsified in Freund's incomplete adjuvant (FIA) was injected intradermally into rats 7 days before challenge with Myco. butyricum. The severity of arthritis was significantly suppressed in rats pretreated with as little as 0.75 mg of HDPG, and the arthritis was completely suppressed in rats pretreated with 3.0 mg of HDPG. This suppression was specific, as the same treatment did not protect against type II collagen-induced arthritis. Suppression of AIA is primarily a property of the HDPG, as suppression of the arthritis was significantly less with pretreatment with 3.0 mg of middle density fractions of PG, and no suppression was observed with pretreatment with the lowest density fraction of PG. Thus we report that pretreatment with cartilage HDPG, but not lower density PG, can induce specific suppression of AIA. These in vivo results support the view that immunity to cartilage HDPG plays a major role in the pathogenesis of AIA, and can induce specific tolerance to this type of arthritis.

Animals↗
PubMed1994

Tornwaldt's disease.

Tornwaldt's disease was first described by Tornwaldt as one of the causes of epipharyngitis, and is an inflammation or abscess of the embryonic remnant cyst of the pharyngeal bursa appearing at the posterior median wall of the nasopharynx. Although many cases are symptom-free, symptoms can often be caused by nasal tamponade, trauma, adenotomy, or other mechanical stimuli. Only a few cases have been reported in Japan between 1929 and 1992. At about the 10th week of embryonic development, the pouch, which forms by adhesion of the pharyngeal ectoderm to the notochord at the most cranial end of the notochord, becomes closed at the orifice (cystic type), or crusts adhere to the orifice without closing (crust type). Symptoms are those of upper respiratory tract infection with obstinate occipital pain, purulent choanal discharge, nasal obstruction, halitosis, feeling of ear fullness, clearing of the throat, etc. Posterior rhinoscopy, simple lateral view X-ray tomography, nasopharyngeal fiberoscopy, CT scan and MRI are useful in showing adhesion to the cervical vertebrae. While complete extirpation via a transpalatal approach is desirable, incision or excision of the cyst can also be performed.

Cysts↗