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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 811 records · Page 45Linked to original sources
PubMed1992

Stimulation of IgM production in human-human hybridoma HB4C5 cells by chitosan.

We screened for immunoglobulin production stimulating factors (IPSFs) in polysaccharides using human-human hybridoma cells, HB4C5, cultured in serum-free medium. Among polysaccharides, citrus pectin, locust bean gum, and chitosan stimulated IgM production of HB4C5 cells. Especially chitosan showed the strongest IPSF activity; 100 ng/ml of chitosan stimulated IgM production approximately 5-fold. Chitosan had several characteristics as IPSF, as follows. 1) For the IPSF activity, 70-90% deacetylation was essential. 2) Chitosan oligomers (n = 5, 6, 7) and chitin oligomers (n = 5, 6, 7) showed no IPSF activities. 3) The IPSF activity of chitosan was inhibited by glucosamine, one of the constitutive sugars of chitosan. 4) Chitosan stimulated IgM production of human lymphocytes in serum-free culture, but not IgG or IgA, nor in serum-supplemented culture.

Cell Line↗
PubMed1992

Prediction of postoperative performance status in patients with giant bulla.

To predict the postoperative improvement in performance status after bullectomy, preoperative pulmonary function and dyspneic grade were evaluated in 20 patients with giant bulla. The patients were divided into two groups, based on postoperative performance status: group 1 consisted of 15 patients with improved status after surgery; and group 2 of five patients with worsened status after temporary improvement. To determine correlation with the groups, preoperative functional measurements such as %VC, FEV1%, MMF, PEFR, RV/TLC, delta N2, LCI, and PNCD were then analyzed by the multivariate statistic method; results of delta N2 and FEV1% showed significant correlation with the groups. Prediction of the groups based on the two measurements agreed with the actual results except in one patient. These results show that postoperative improvement in performance status of patients with giant bulla can be predicted on the basis of preoperative pulmonary function.

Adult↗
PubMed1992

[Psychosocial approach of the epileptic patient: analysis of 30 adults].

Psychosocial aspects of patient's life were analysed in 30 patients with epilepsy aged over 18 years old. At this age people usually are apt by themselves to exert several psychosocial activities. Professional, familial, social, scholar, affective, sexual and religious activities were evaluated in our group of patients. Results evidence that epileptic patients studied show several kinds of difficulties in their psychosocial adjustment.

Adult↗
PubMed1992

Serum tumor necrosis factor activity in inflammatory bowel disease.

Serum tumor necrosis factor (TNF) levels in 33 patients with inflammatory bowel disease (IBD) were measured by using a sensitive enzyme immunoassay. Four of five Crohn's diseases (CD) and nine of twenty eight ulcerative colitis (UC) had elevated levels of serum TNF. In active CD or UC, a greater fraction of patients studied had significantly increased serum TNF levels (3/3 for CD and 8/11 for UC). Production of TNF by peripheral blood monocytes when stimulated by lipopolysaccharide was also increased in these patients and correlated with their serum TNF levels. These results suggest that TNF may have some pathoetiological meaning in IBD.

Adult↗
PubMed1992

[The reactivity of dispersed human lung mast cells and peripheral blood basophils to acetylcholine].

To clarify the relation between human lung mast cells and parasympathetic nerve function as well as IgE mediated allergic reactions, highly purified dispersed human lung mast cells were obtained by using the techniques of scissors dispersion, enzymatic treatment, percoll centrifugation and exclusion of adherent cells. The reactivity to acetylcholine was examined by observing the histamine release of purified mast cells. Moreover, peripheral blood basophils, which have many functional similarities with mast cells, were also examined in the same manner. The following results were obtained; 1) Histamine was significantly released from dispersed human lung mast cells at a final concentration of 10(-5) M acetylcholine (p less than 0.05); the peak of histamine release was 10(-4) M of acetylcholine. Acetylcholine had the additional effect of releasing histamine in response to anti-IgE. Histamine release was partially inhibited by 10(-5) M atropine. 2) Basophils had no response to acetylcholine. These results suggest that human lung mast cells play an important role in the defensive mechanism as an effector cell of acetylcholine-mediated autonomic nerve system as well as IgE-mediated allergic reaction.

Acetylcholine↗
PubMed1992

[Acoustic neurinoma associated with facial neurinoma--a case report].

A 38-year-old man developing slowly progressive left facial paresis was admitted to our hospital. The clinical diagnosis of "adhesive arachnoiditis was made. The first operation was performed in December 1987, and his symptom disappeared postoperatively. Three years later, left facial paresis recurred together with trunkal ataxia. A computed tomography and magnetic resonance image revealed two tumors located at the left cerebellopontine angle region and in the left middle cerebral fossa. These two tumors were thought to arise in the different cranial nerve. Under the clinical diagnosis of acoustic neurinoma associated with facial nerve neurinoma, the two step-operation was designed for total removal of the tumor in December 1990 and January 1991. Intraoperative finding confirmed that these two tumors had the different origin. Pathologic diagnosis was compatible with neurinoma. This patient had no family history of "Neurofibromatosis".

Adult↗
PubMed1992

Dynamical conformational change of DNA induced by synthetic polymers: direct observation by fluorescence microscopy.

Brownian motion and Higher-order structure of DNA molecules complexed with synthetic polymers: poly-L-arginine (pArg) and polyacrylamide (pAAm), were observed using fluorescence microscopy. Quantitative analyses of the conformation and motion of the complexes demonstrate that these two polymers influence the structure of DNA molecules in an opposite way. The electrostatic binding of pArg induces contraction of DNA, whereas the intercalative pseudo-grafting of pAAm extends DNA.

Acrylic Resins↗
PubMed1992

Molecular abnormalities of a human glucose-6-phosphate dehydrogenase variant associated with undetectable enzyme activity and immunologically cross-reacting material.

Among a large number of glucose-6-phosphate dehydrogenase (G6PD) variants associated with different severity of clinical manifestations, enzyme deficiency, and kinetic abnormalities found in humans, only one variant exhibits no measurable activity and lacks an immunologically cross-reacting material in blood cells and other tissues. The mRNA content of the patient's lymphoblastoid cells was found to be normal, and the size of mRNA was also normal (i.e., approximately 2.4 kb). Western blot hybridization indicated that the patient's cells did not produce cross-reacting material. The variant mRNA was reverse transcribed and amplified by PCR. Nucleotide sequencing of the variant cDNA showed the existence of three nucleotide base changes, i.e., a C----G at nucleotide 317 (counting from adenine of the initiation codon), which should cause Ser----Cys substitution at the 106th position (counting from the initiation Met); a C----T at nucleotide 544, which induces the Arg----Trp at the 182d position; and a C----T at nucleotide 592, which induces Arg----Cys at the 198th position of the protein. The existence of three mutation sites was confirmed by sequencing of selected regions of the variant gene. No base deletion or frameshift mutation was found in the variant cDNA. No nucleotide change was detected in the extended 5' region, which included the most distal cap site. When the variant cDNA was expressed in Escherichia coli, the G6PD activity was approximately 2% of that expressed by the normal cDNA, and cross-reacting material was undetectable. However, when the variant mRNA was expressed in the in vitro translation system of rabbit reticulocytes, the variant protein was produced. These results suggest that extremely rapid in vivo degradation or precipitation of the variant enzyme induced by the three amino acid substitutions could be the major cause of the molecular deficiency.

Base Sequence↗
PubMed1992

Temporomandibular joint movement. Evaluation of protrusive splint therapy with GRASS MR imaging.

Ten temporomandibular joints (TMJs) of 5 healthy volunteers and 19 TMJs of internal derangements in 16 patients with splint therapy were examined with MR imaging. T1-weighted images were obtained only in the closed mouth position, and gradient recalled acquisition in steady state (GRASS) images were obtained in active opening and closing phases, allowing a pseudodynamic display of TMJ movement. All patients received protrusive splint treatment. The usefulness of MR imaging to assess the efficacy of splint therapy was evaluated. Corrected disk position with the splint in place was clearly demonstrated in 9 TMJs, corresponding with elimination of reciprocal clicking. Ten other TMJs of anterior disk displacement without reduction showed uncorrected disk position by the splint. This information could confirm the therapeutic efficacy, or suggest other treatment alternatives. GRASS MR imaging can provide accurate and physiologic information about disk function in initial and follow-up assessment of protrusive splint therapy.

Adolescent↗
PubMed1992

Human T lymphotropic virus type-I (HTLV-I) immortalizes human T cells in vitro--its implication in the pathogenesis of adult T cell leukemia (ATL).

HTLV-I is the first human retrovirus that was isolated from a patient with T-cell malignancy in 1980 in the United States. HTLV-I is detected in most patients with adult T cell leukemia (ATL) and healthy carriers, who are frequently found in the southwestern parts of Kyushu and Shikoku Districts. HTLV-I-infected cells express IL-2 receptors, and HTLV-I-infected T cell lines can be established from most of ATL patients in culture in the presence of IL-2. Furthermore, these IL-2 dependent T cell lines often begin to proliferate in the absence of IL-2 and to not respond to IL-2, despite IL-2 receptors on their cell surface, thus mimicking ATL cells in vivo. These findings suggest that HTLV-I is an etiological agent of ATL. In this mini-review, the T cell immortalizing activity of HTLV-I in vitro, with special reference to the evolution of ATL cells based on our results, is described.

Antigens, CD↗
PubMed1992

[Diseases and operative modes of tracheobronchoplasty].

In 251 patients of tracheobronchoplasty, the disease distribution and the indicative expansion were analysed. The largest series was lung cancer encountered in 49%, followed by thyroid cancer in 20%, posttracheostomy tracheal stenoses, primary tracheobronchial tumors, and tuberculosis in 7-8% respectively, and others in remaining 4%. In lung cancer, two way of operative modes have been tried, which were carinal resection extensively and sleeve or wedge segmentectomy limitedly. Laryngotracheal anastomosis increased applicable cases in thyroid cancer and posttracheostomy subglottic stenosis. Preoperative irradiation for adenoid cystic carcinoma increased the cases for operation. A new carinal reconstruction via the subaortic arch approach for tuberculous stenosis was successfully underwent. End-to-end anastomosis instead of partial suture was advisable in the early stage of traumatic bronchial rupture. Congenital airway malformation is a disease to be divised some operations which might furthermore increase operative modes. In summary, 38 operative modes have been experienced so far, and these might increase in number depending to diseases.

Adolescent↗
PubMed1992

[Intra-bullous ventilation of giant bulla: does slow ventilation space on multi-breath nitrogen washout test mean that giant bulla is present?].

Intra-bullous ventilation and uneven ventilation in patients with giant bulla were studied by the multi-breath nitrogen washout and 133Xe washout tests. Fourteen patients underwent the nitrogen washout test before and after bullectomy; 2 of them also underwent the 133Xe washout test before surgery. After bullectomy, pulmonary nitrogen clearance delay and alveolar dilution rate (ADR) of slow ventilation space improved significantly (p less than 0.01) from 202.5% to 51.5%, and from 0.98 to 0.95, respectively. The dilution rate of 133Xe in the bullous region, based on the 133Xe clearance curve, showed the same values as the nitrogen washout test. Therefore, we considered that bullous ventilation could be estimated by the ADR of the nitrogen washout test and that uneven ventilation resulted from the ADR difference between the giant bulla and the nonbullous lung. When the nonbullous lung region was emphysematous, however, it was impossible to estimate the intra-bullous ventilation from the nitrogen washout test.

Adolescent↗