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Biomedical subjects

N Iida

Publications and source records attributed to N Iida.

At least 109 records · Page 6Linked to original sources
PubMed1989

Physical properties of resistance vessel wall in peripheral blood flow regulation--I. Mathematical model.

A mathematical model is introduced to investigate the influence of the physical properties of the resistance vessel wall on the metabolic and myogenic mechanisms. The resistance vessel wall is assumed to have an elastic property and the elastic modulus to be a function of pressure (myogenic) and flow (metabolic). Blood is Poiseuille's flow. The resulting mathematical equations for pressure-flow, pressure-diameter, pressure-wall tension and pressure-wall elastic modulus relationships introduced obey Laplace's law. Poiseuille's law and Hooke's law. In comparison with the experimental data (pressure diameter), the mathematical model is confirmed to explain well the dynamic behavior of the resistance vessel wall in vivo.

Elasticity↗
PubMed1989

Role of physical properties of resistance vessel wall in regulating peripheral blood flow--II. Structural and mechanical behavior.

In order to examine the structural and mechanical properties of the vessel wall resistance when subjected to autoregulatory flow control, a mechanical model for the vascular wall was derived from a mathematical model. The mechanical model was an analogue model which connected in series the Maxwell model (elastic modulus: K3) with the parallel elements of Hill's model (elastic modules: K2) and Hooke's elastic model (elastic modulus: K1); it was also mathematically equivalent to the Spring model (see part I). The structural and mechanical properties of the resistance vessel wall were characterized by the three elastic moduli (K1, alpha K2 and K3) [mmHg]. The parameter alpha was a modification factor of the elastic modulus K2 given by the myogenic mechanism. After a numerical analysis of the experimental data given by the mechanical model, we confirmed that the arterial pressure range for autoregulatory flow controls shifted to the upper region with an increase of the elastic modulus K1 and the flow regulation was reduced.

Animals↗
PubMed1989

Complement C6 and C7 polymorphisms in Japanese patients with chronic glomerulonephritis.

C6 and C7 types were studied in 158 Japanese patients with different types of chronic glomerulonephritis: 75 patients with IgA nephropathy (IgA-N); 49 patients with idiopathic membranous nephropathy (IMN), and 34 patients with minimal-change nephrotic syndrome (MCNS). There were significant differences in the C6 and C7 allele and phenotype frequencies between the patient groups and controls. A strong association was found between IgA-N and C7 5 phenotype (p less than 0.001, RR = 12.71), and between MCNS and C7 5 phenotype (p less than 0.001, RR = 14.20). A significant association between MCNS and C6 B2 phenotype (p less than 0.05, RR = 2.42) was also found. In the IMN patient group, a significant association with C7 4 phenotype (p less than 0.05, RR = 2.42) was observed. Thus, C6 and C7 phenotypes may be causative factors in the development of chronic glomerulonephritis.

Complement C6↗
PubMed1989

Effects of venous pressure elevation on myogenic vasoconstrictive responses to static and dynamic arterial pressures.

In order to establish the nature of the stretch-evoked dynamic properties of vascular smooth muscle in arterioles, we have examined the static and dynamic effects of both arterial pulse pressure and elevated venous pressure on the resistance vessels (arteries and arterioles) in an intestinal mesenteric preparation derived from dogs. The dynamic myogenic response to stretch stimuli was directly related to both the frequency of arterial pulse pressure (1-20 c/min) and the level of venous pressure (0-45 mmHg). Under elevated venous pressure (20 mmHg), the mean arterial flow decreased with an increase in the frequency of arterial pulse pressure. The arteriolar vascular tone (namely, vascular resistance) was seen to be enhanced. We found that elevated venous pressure promotes active constriction (9-53%) of arteriolar smooth muscle (myogenic mechanism). The elevation of venous pressure also caused a rhythmic constriction (vasomotion) in the site of both vein and artery, which was completely abolished by an alpha-blocker (phentolamine). The results suggest that during venous pressure elevation a very pronounced myogenic constriction in terminal arterioles is caused by either a local neural reflex or a propagated myogenic response in the arteriolar network.

Animals↗
PubMed1989

[Acute phase protein (alpha 1 AT) as a tumor marker in patients with ovarian cancer (OC)].

Serum alpha 1 AT was measured in 30 healthy women, 30 pregnant women, in 97 patients with various benign gynecologic diseases, and 38 patients with OC. The positive ratio (cut off level: 317 mg/dl) in OC patients was 78.9% (30/38), 11.3% (11/97) in patients with a benign gynecologic disease, 90% (27/30) in pregnant women, and 0% (0/30) in healthy women. Histologically 92.3% of the patients (12/13) with a serous cystadenocarcinoma, 50% (4/8) with an endometrioid carcinoma, and 77.8% (7/9) with a mucinous cystadenocarcinoma were positive, but only 5.9% of the patients with a chocolate cyst were positive. Thus it was found that alpha 1 AT is a useful tumor marker in diagnosing OC.

Acute-Phase Proteins↗
PubMed1989

[Adult T cell leukemia with CD4- and CD8-].

A 53-year-old woman born in Kamo village of Shizuoka prefecture was admitted to Juntendo Izunagaoka hospital complaining cough and appetite loss. On physical examinations, general lymphadenopathy and hepatosplenomegaly were recognized. And also dry rales and wet rales were heard in the bilateral lungs. On hematological examinations, leukocytes has counted 74,900/microliters, of which 61% atypical lymphocytes, and there were HTLV-I infection and positive anti-ATLA antibody. By the above results, she was diagnosed as adult T cell leukemia (ATL). T cell subset analysis was (CD4-, CD8-, CD3-), which is rare in ATL. Three months after the admission, she was died of disturbances of respiratory function in spite of VEPA therapy. Surface marker changed from CD3- to CD3+ in the course. To illuminate this mechanism will be a key step for the future study.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

Monoclonal antibodies directed to a disulfated glycosphingolipid, SB1a (GgOse4Cer-II3IV3-bis-sulfate), associated with human hepatocellular carcinoma.

Two murine monoclonal antibodies, 2H6G5 (IgM) and 4A9E10 (IgG3), were obtained by using either cultured human hepatocellular carcinoma cells (PLC/PRF/5) or the acidic glycolipid mixture prepared from the same cells as immunogens. The antigen in PLC/PRF/5 cell membranes recognized by both antibodies was identified as a disulfated acidic glycolipid, GgOse4Cer-II3IV3-bis-sulfate (SB1a). Both antibodies reacted specifically with SB1a, and no significant reactivity was noted with other sulfated glycolipids or gangliosides except that the antibody 2H6G5 showed a weak cross-reactivity with LacCer-II3-sulfate (SM3), another sulfated glycolipid which partly shares the same carbohydrate structure as SB1a. The SB1a antigen is a relatively minor glycolipid in PLC/PRF/5 cells, but it was strongly expressed at the surface of PLC/PRF/5 cells as ascertained by cytofluorometry using both antibodies. A significant amount of SB1a antigen was present in 3 of the acidic glycolipid fractions isolated from 15 human hepatocellular carcinoma tissues as well as in the acidic glycolipid fraction prepared from PLC/PRF/5 cells, while all the acidic glycolipid fractions prepared from cirrhotic livers and a normal liver were essentially negative for SB1a, as ascertained by both solid phase enzyme immunoassay and the thin-layer chromatography-immunostaining method. These results strongly suggest that the SB1a antigen as defined by these new monoclonal antibodies is associated with human hepatocellular carcinoma.

Animals↗
PubMed1988

Relation between the level of IgG subclasses and infections in patients with systemic lupus erythematosus.

IgG subclasses in sera from 48 patients with systemic lupus erythematosus (SLE) were examined by enzyme-linked immunosorbent assay (ELISA), and the relation between the level of IgG subclasses and infections was investigated. In patients with SLE, IgG2 and IgG4 decreased when compared to normal subjects. In patients with infections, IgG3 and IgG4 were decreased when compared to patients without infections. When the level of IgG3 was less than 60 microliter/ml and the level of IgG4 was less than 20 microliters/ml, infection was increased, especially mycotic infections. It was shown that the estimation of IgG3 and IgG4 serum levels served as important indices for infection.

Adult↗
PubMed1987

Distribution of cholinesterase in canine venous system.

Cholinesterase (ChE) activity was examined in 15 veins from dogs by pharmacological and histochemical procedures. Potentiation of acetylcholine (ACh)-induced contractile response by neostigmine was observed in helical and longitudinal strips of portal, mesenteric veins and middle segment of the inferior vena cava, but not in the other 12 veins. Histochemical studies with an electron-microscope (the method of Karnovsky-Roots) revealed that ChE activity was identified as high density granules around the smooth muscle cells only in the former three veins. The visible ChE activity was abolished by pretreatment with neostigmine.

Animals↗