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Biomedical subjects

M Yamashina

Publications and source records attributed to M Yamashina.

At least 19 recordsLinked to original sources
PubMed2001

Improved nasal absorption of drugs using poly-L-arginine: effects of concentration and molecular weight of poly-L-arginine on the nasal absorption of fluorescein isothiocyanate-dextran in rats.

The effects of the concentration and molecular weight of poly-L-arginine (poly-L-Arg) on the in vivo nasal absorption of fluorescein isothiocyanate-labeled dextran (MW, 4 kDa, FD-4) in rats were studied. When poly-L-Arg with a range of different molecular weights (MW, 8.9, 45.5 and 92.0 kDa) was applied intranasally at various concentrations, the bioavailability (F(0-9 h)) of FD-4 increased with the increasing concentration of poly-L-Arg. The enhanced absorption was also dependent on the molar concentration, in that the poly-L-Arg with a higher molecular weight increased F(0-9 h) at a lower molar concentration. In addition, for each applied concentration, the poly-L-Arg exhibited a molecular weight-dependence as far as the enhancement of FD-4 absorption was concerned. On the other hand, the maximum absorption rate (MAR) of FD-4, calculated by means of a deconvolution method, tended to reach a maximum plateau level at a lower applied concentration for the poly-L-Arg with the highest molecular weight, but this plateau level was almost the same for poly-L-Arg with molecular weights of 45.5 and 92.0 kDa. Moreover, the simulated absorption profiles of FD-4 indicate that the degree of enhancement (the level of MAR and the subsequent reduction in the absorption rate) was dependent on the molecular weight of poly-L-Arg, while the effect of poly-L-Arg was maintained for a longer period, depending on the applied concentration, although the MAR was relatively similar. These results indicate that the molecular weight of poly-L-Arg appears to affect both the enhancing efficiency (absorption rate) and the time-frame of this enhancing effect, whereas the concentrations of each poly-L-Arg system applied only have an effect on the time-frame. These effects may also be associated with the charge density of a poly-L-Arg molecule.

Absorption↗
PubMed2001

Schizophrenic outpatient perceptions of psychiatric treatment and psychotic symptomatology: an investigation using structural equation modeling.

Schizophrenic patient perceptions of treatment have clinical value and deserve detailed psychiatric investigation. The present study sought a model indicating statistically estimated cause-effect relationships of perceptions and psychotic symptomatology of outpatients with schizophrenia by applying a method of structural equation modeling. The perceptions included in this model were patient satisfaction with treatment, perceptions of their treating psychiatrists, and patient-role perception. Scores of Positive and Negative Syndrome Scale and poor insight measures were added to the model as possible influential factors. The constructed model revealed that the poor insight exerted a major influence on the patient-role perception that had small effects on the reliable therapist perception and the satisfaction. It was also shown that satisfaction was chiefly determined by the reliable therapist perception that was formed in the treatment relationship, rather independently of the other construct. These findings were valuable in terms of their implications for understanding the makeup of the perceptions and the strategy for interventions to improve them.

Adult↗
PubMed1999

P300 and disability of daily life in schizophrenia.

1. The relationship between the P300 component of event-related potentials and disability of daily life was examined in schizophrenia. The subjects were 26 chronic schizophrenic patients. 2. Disability of daily life was assessed by using the Life Assessment Scale for Mental Illness (LASMI). 3. Auditory event-related potentials were recorded during a standard oddball task. 3. P300 amplitude correlated negatively with general psychopathology scale of PANSS (r = -0.416) and Work of LASMI (r = -0.417). P300 latency did not correlate with any of PANSS or LASMI score. 4. These results indicate that P300 amplitude can be an index for disability of daily life in schizophrenia.

Activities of Daily Living↗
PubMed1998

Interrater reliability of the Japanese version of the Positive and Negative Syndrome Scale and the appraisal of its training effect.

The purpose of the present study is to test interrater reliability of the Japanese version of the Positive and Negative Syndrome Scale (PANSS) and to examine factors possibly affecting the reliability. The study group conducted the PANSS rating on 20 patients with DSM-IV schizophrenia. For the analysis of interrater reliability, intraclass correlation coefficient (ICC) was calculated. The ICC for individual items of the PANSS ranged from 0.26 to 0.92, and those for the positive, negative, and general psychopathology subscales were 0.85, 0.83 and 0.75, respectively. The Cronbach's alpha coefficient for the subscales were 0.84, 0.87 and 0.76, respectively. The interrater reliability and the internal consistency were satisfactory and similar to those obtained in the antecedent studies. No salient training effect was found in a sequential analysis of the concordance rate. It is concluded that the Japanese version of the PANSS is a reliable and efficient tool for comprehensive assessment of the schizophrenic syndrome.

Adult↗
PubMed1997

Unique expression of HRF20 (CD59) in human nervous tissue.

Damage to autologous tissue by complement is limited by several widely distributed membrane-associated glycoproteins which restrict the action of the complement in homologous species. These include decay accelerating factor (DAF), membrane cofactor protein (MCP) and 20 kDa homologous restriction factor (HRF20,CD59). Using immunohistochemical techniques, we examined the localization of these proteins in the central nervous system (CNS) and peripheral nervous system (PNS) using non-neurological human nervous tissue since some complement components have been demonstrated to be synthesized in the CNS. There was no evidence of parenchymal staining by anti-DAF or anti-MCP antibodies in either type of tissue except for the staining of the endothelium in capillaries. On the other hand, anti-HRF20 antibody clearly stained myelinated axons in the CNS as well as Schwann cells in the PNS. In addition, we detected positive staining by anti-DAF antibody in the PNS of a Paroxysmal nocturnal hemoglobinuria (PNH) patient who is genetically deficient in HRF20.

2-Methyl-4-chlorophenoxyacetic Acid↗
PubMed1995

A case of Fabry's disease with granulomatous interstitial nephritis.

A 15-year-old boy with proteinuria and hematuria is reviewed in this study. He was first found to have urinary abnormalities at the age of 13 years, and his renal function was exacerbated for a short duration. Renal biopsy was performed to make a histological diagnosis and to establish adequate therapy. Light microscopy showed marked tubulointerstitial inflammation with granulomatous changes, and electron microscopy revealed that numerous osmiophilic inclusions were present in podocytes, mesangial cells, and endothelial cells of the glomeruli and in epithelial cells of the tubules. The alpha-galactosidase activity of lymphocytes from the patient was measured, and the results of this assay indicated that the patient's lymphocytes had a low level of alpha-galactosidase activity. Therefore, the patient was diagnosed as having Fabry's disease with renal dysfunction. This study demonstrated that the onset age of renal insufficiency in Fabry's disease may be earlier than that described previously, and that when granulomatous interstitial nephritis is developed, renal function may deteriorate progressively.

Adolescent↗
PubMed1993

Immunohistochemical demonstration of membrane cofactor protein (MCP) of complement in normal and diseased kidney tissues.

The immunohistochemically stained membrane cofactor protein of complement (MCP/CD46), one of the complement regulatory proteins, was up-regulated in some diseased kidney tissues. MCP in diseased kidneys was strongly concentrated along the glomerular capillary walls as well as in the mesangial regions, while MCP in normal kidneys was weakly detected in all glomerular structural cells and in the epithelial cells of tubules. Since the enhanced staining was noted in those areas where depositions of C3b/C3c occurred, ongoing complement reaction might be responsible for the up-regulation of MCP expression. MCP expression may be up-regulated by complement fragments generated during complement activation in glomerulonephritis. Furthermore, anti-MCP staining was stronger in intensity in patients with moderate to massive proteinuria, indicating that up-regulation of MCP expression could be directly correlated to the kidney damage.

Antigens, CD↗
PubMed1993

[Clinical assessments on pre-treatment prognostic factors in 138 patients with advanced prostatic carcinoma (stage D2)].

We investigated the prognostic factors in 138 patients with stage D2 prostatic cancer by univariate and multivariate analyses. Analysis was restricted to 8 pre-treatment parameters, that is, age, general condition (PS), pain, number of metastases on bone scan, acid phosphatase value, Gleason's primary pattern, secondary pattern, and nucleoli grading. In addition, 4 therapeutic modalities except routine endocrine therapy, that is, castration, oral administration of estramustine phosphate, of 5-fluorouracil (5-FU) or its analogue, and combination chemotherapy, during the whole treatment period were included in the analysis. Univariate analysis (Kaplan-Meier method) showed only PS to be a significant prognostic factor. Multivariate analysis (Cox's proportional hazard model) revealed that PS, Gleason's primary pattern, oral administration of 5-FU or its analogue and combination chemotherapy were significant prognostic factors. However, patients treated by combination chemotherapy had poorer prognosis and chi 2 values of combination chemotherapy was the highest among the four parameters cited above. These results suggested that the 8 pre-treatment parameters examined in this study were not sufficient for predicting the prognosis of each patient.

Acid Phosphatase↗
PubMed1992

Paroxysmal nocturnal hemoglobinuria due to hereditary nucleotide deletion in the HRF20 (CD59) gene.

HRF20 (CD59) is a membrane glycoprotein which protects cells from the membrane attack reaction of homologous complement. A patient who is completely deficient in HRF20 expression and is suffering from paroxysmal nocturnal hemoglobinuria (PNH) was studied. His parents are cousins and both have decreased HRF20 expression, suggesting that the deficiency is genetic. We established a cultured cell line (NCU1) which is HRF20 deficient from the patient's lymphocytes by Epstein-Barr-virus (EBV) infection. Northern blot analysis revealed HRF20 mRNA signals, indicating that HRF20 mRNA were transcribed. HRF20 cDNA was amplified by the polymerase chain reaction (PCR) method. Sequencing of the cDNA from the NCU1 showed two single-base deletions at amino acid 16 and 96 from the N terminus of the mature protein. Deletion in the genomic DNA of peripheral blood lymphocytes was confirmed by the DNA sequence of an HRF20 open reading frame containing amino acid 16. Furthermore, the patient's parents and sister possessed both intact and deleted genomic HRF20 DNA while his brother's DNA was intact. These findings demonstrate that the HRF20 deficiency was genomic in origin, and that complete deletion was brought about by a homozygous abnormality in the HRF20 gene. The base deletion caused a codon frame shift resulting in failure to produce intact HRF20 protein in the patient.

Antigens, CD↗
PubMed1992

Myofibroblastic pseudotumor mimicking epididymal sarcoma. A clinicopathologic study of three cases.

The clinical and pathologic features of three cases of epididymal pseudotumor are described with emphasis on its differential diagnosis and histopathogenesis. The first lesion was found histologically worrisome in the region of ductus epididymis by a torsioned testis in an 8-month-old boy, although the lesion was clinically indistinctive, and grossly not remarked. Histodiagnostic difficulties are encountered because this lesion forms numerous infiltrative spindle cells in haphazard arrangement. Ultrastructurally, the cell components of this lesion are predominantly myofibroblasts, intermediate cells between fibroblasts and myocytes. Similar epididymal lesions with the same cell components were identified in the two other infantile cases on the review of 36 consecutive orchiectomy specimens all obtained for testicular torsion. These three boys were found to present with a relatively gradual clinical course of the testicular torsion. It is suggested that myofibroblastic proliferation in the epididymal location histologically reminiscent of sarcomas occurs under ischemic circumstances.

Diagnosis, Differential↗
PubMed1992

Follicular neoplasms of the thyroid. Total circumferential evaluation of the fibrous capsule.

Fourteen encapsulated follicular neoplasms were extensively dissected without tangential sectioning to represent the circumference of the entire capsule on sequential histologic sections. A thorough evaluation of these sections divided the 14 cases into five benign adenomas, seven encapsulated carcinomas with only intracapsular angioinvasion, and two minimally invasive carcinomas with focal capsular invasion. Among these nine early-stage follicular carcinomas it was found that angioinvasion occurred multicentrically in at least seven and showed a geographically even distribution. Angioinvasion was found far more often than capsular invasion on the circumference of all nine early-stage carcinomas. Multiple sections produced by this extensive dissection aided the disclosure of minute but convincing findings of angioinvasion. Also, a fibrous capsule as thick as 3.8 mm at its maximum thickness as well as an irregular interface between the capsule and parenchyma were often found to be characteristic of these early-stage carcinomas. Thus, upon comparison with 38 previous cases of similarly localized follicular neoplasms, in which randomly sampled histologic sections yielded diagnoses of benign adenoma (21 cases) and encapsulated or minimally invasive carcinoma (17 cases), extensive circumferential evaluation of the capsule is considered to allow not only effective distinction of follicular neoplasm with slight invasive capability from benign adenoma but also adequate assessment of invasive foci with application of strict criteria. Despite the similarity of clinical prognosis among all the above adenomas and early-stage carcinomas, given the limited follow-up period, an extensive examination method introduced herein is practically useful and necessary for identification of malignancy in encapsulated follicular neoplasms.

Adenocarcinoma↗
PubMed1991

Suppression of immunoglobulin production of lymphocytes by intravenous immunoglobulin.

The proliferative responses and the immunoglobulin production of peripheral blood mononuclear cells to pokeweed mitogen were dose-dependently suppressed by sulfonated intravenous immunoglobulin (IVIG), polyethylene glycol-treated IVIG, pH 4-treated IVIG, or human gamma-globulin, but they were not or only slightly suppressed by human serum albumin or pepsin-treated IVIG. Moreover, the suppression of immunoglobulin production by sulfonated IVIG, polyethylene glycol-treated IVIG, or pH 4-treated IVIG was seen in the cases in which B cells preincubated with IVIGs were cocultured with T cells and monocytes preincubated with or without IVIGs and in the cases in which monocytes preincubated with IVIGs were cocultured with T cells and B cells preincubated with or without IVIGs. However, in the cases in which only T cells were preincubated with IVIGs, immunoglobulin production was not suppressed. The suppression of the monocyte function by IVIGs tended to be less than the suppression of the B-cell function by IVIGs. Moreover, the suppression by IVIGs was blocked by anti-human IgG Fc. Our results suggest that IVIGs suppress the immunoglobulin production of lymphocytes through suppression of the B-cell function and the antigen presenting-cell function by attachment of IVIGs to Fc receptors of B-cell membranes and antigen presenting-cell membranes.

Antigen-Presenting Cells↗