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Biomedical subjects

N Fujiki

Publications and source records attributed to N Fujiki.

At least 73 records · Page 4Linked to original sources
PubMed1993

Sulfite suppresses transducer function of the carotid sinus baroreceptor.

The purpose of this study was to examine the effect of sodium metabisulfite (MBS) solution on the transducer function of the carotid sinus baroreceptor. In anesthetized dogs with vagotomy, we vascularly isolated the carotid bifurcation to load a pressure on the carotid sinus baroreceptor. As the pressure load, we used a slow ramp increase (0.7 mmHg/s) in intracarotid sinus pressure (ICSP). The response of carotid sinus nerve activity (CSNA) to the slow ramp increase in ICSP was suppressed when the isolated carotid sinus was filled with the MBS solution of 10(-2) M. This suppressive effect of MBS solution on the response of CSNA was reversible. The MBS solution had no effect on the pressure-volume relationship of the arterial wall of the isolated carotid sinus and on the impulse conduction of carotid sinus nerve. This suppressive effect of the MBS solution of 10(-2) M was weakened by introducing oxygen gas into the solution to lose the total sulfite anions in the solution. These results suggest that: (1) the MBS solution reversibly suppresses the transducer function of the carotid sinus baroreceptor; (2) the target construction of the carotid sinus region that was affected by the MBS solution might be the carotid sinus baroreceptor nerve terminal where ICSP was transduced into carotid sinus nerve firing; and (3) the suppressive effect might be provoked by the sulfite anions in the MBS solution.

Animals↗
PubMed1993

The effect of the B subunit of cholera toxin on the action of nerve growth factor on PC12 cells.

Exogenous gangliosides, especially ganglioside GM1 (GM1), seem to potentiate the action of nerve growth factor (NGF). We have examined the possible regulation of the NGF signaling pathway in PC12 cells by the B subunit of cholera toxin (CTB), which binds to endogenous GM1 specifically and with a high affinity. CTB treatment (1 micrograms/ml) enhanced NGF-induced neurite outgrowth from PC12 cells, NGF-induced activation of ribosomal protein S6 kinase, and NGF-induced stimulation of trk phosphorylation. CTB plus NGF also caused a greater inhibition of [3H]thymidine incorporation into DNA than did NGF alone. These enhancing effects of CTB were blocked by the presence of cytochalasin B in the culture medium but were not affected by the presence of colchicine or by the depletion of Ca2+ in the medium. 125I-NGF binding experiments revealed that CTB treatment did not affect the specific binding of NGF to the cells. These results strongly suggest that the binding of cell surface GM1 by CTB modulates the pathway of intracellular signaling initiated by NGF and that the association of CTB with a cytoskeletal component is essential for these effects.

Animals↗
PubMed1993

Early progression stage of malignancy of human colon border-line adenoma as revealed by immunohistochemical demonstration of increased DNA-instability.

The degree of DNA-instability was used as the marker of malignancy and applied to adenoma (7 benign cases and 17 border-line cases) and cancer (8 carcinoma-in-adenoma cases and 17 invasive cancer cases) of human colon. Proliferative activity by PCNA index and the activity of protein synthesis by AgNORs were also estimated for all cases as the supporting markers of malignancy. In all border-line cases, the following findings were obtained: (1), the degree of DNA-instability as revealed by immunohistochemical staining with anti-single-stranded DNA antiserum after acid hydrolysis was increased in border-line adenoma to the level of invasive overt cancer, indicating its malignancy with marked DNA-instability; (2), reflecting the malignant character, abnormal mitosis and single cell necrosis were usually observed in all border-line adenomas by fluorescent Feulgen staining, indicating the DNA alterations; (3), not only the parenchymal but also the stromal PCNA indices were statistically larger in border-line adenoma than in benign adenoma, indicating the "stromal activation" in malignancy; (4), the volumes of AgNORs were much increased in border-line adenoma in comparison with those in benign adenoma, and these showed further increases with the progression of malignancy to the invasive overt cancer. These findings indicate that border-line adenoma of human colon has already malignant character at the early progression stage, although no apparent epithelial atypia, or destructive invasion, is taking place.

Adenoma↗
PubMed1992

Systems analysis of the carotid sinus baroreflex system using a sum-of-sinusoidal input.

The purpose of the present study was to determine the dynamic characteristics of the carotid sinus baroreflex system (CS) employing systems analysis. In 28 anesthetized and mechanically ventilated dogs with vagotomy, intracarotid sinus pressure (ICSP) was changed artificially. In protocol 1 (n = 7), we estimated the transfer function of the CS by means of a single sinusoidal input (SIN), the Gaussian white-noise input (GWN), and a sum-of-sinusoidal input (SUM). The transfer function of ICSP to systemic arterial pressure (SAP) was second-order delay with an identical corner frequency of 0.025 Hz and damping ratio of 0.7. The steady-state gain estimated using GWN (1.12 +/- 0.13) or SUM (1.13 +/- 0.08) was significantly smaller than SIN (1.69 +/- 0.25). In protocol 2, to find the reason why there was a difference among the estimated steady-state gains, we investigated the effect of ICSP pulsation on the open-loop gain of the CS. The maximum gain of the gain curve was decreased and the operating range was increased significantly with the 2-Hz pulsation. We could simulate the above phenomena by using a model with a nonlinear sigmoidal relationship between ICSP and SAP. The dynamic characteristics of the CS appeared to be changed by pulsation, but this phenomenon was attributable to the sigmoidal nature of the relationship between ICSP and SAP. Pulsation decreases the maximum gain and increases the operating range, which may contribute to stability of the CS and homeostasis of SAP.

Animals↗
PubMed1992

Importance of acidic mucin secretions by foveolar and mucous neck cells of rat fundic mucosa as the defence mechanisms against HCl as revealed by fasting.

The localization of neutral mucin and acidic mucins in both control and fasted rat gastric fundic mucosa were examined by microscopic and electron microscopic histochemical methods. By Carnoy's fixation, the surface mucous coat of the control rat gastric fundic mucosa was found to be composed of alternating layers of acidic mucins and neutral mucin, indicating the synchronous and cyclic secretions of them. In many gastric pits of the fundic glands, the acidic mucins were found to spring out from the deep foveolar regions like volcanoes. This phenomenon may suggest that the acidic mucins play a fundamental role in protecting the pit cells against HCl during its passage, and the layers of neutral mucin and acidic mucins in the surface coat is the safeguard against the HCl and digestive enzymes in the gastric lumen. In the fasting rat gastric fundic mucosa, the acidity and the amount of the gastric juice were markedly decreased, indicating the suppressed secretions of mucins and HCl. The decreased production of sulfomucin was directly demonstrated by 35SO4-autoradiography. Many mucous neck cells existing in close association with the parietal cells were ballooned due to accumulation of alcian blue (AB)-positive but high iron-diamine (HID)-negative sialomucin, which was not demonstrable in the control. The secretory granules of sialomucin contained in the ballooned mucous neck cells were positively stained ultrastructurally with cacodylate-ferric colloid to stain acid mucopolysaccharides.

Acid Phosphatase↗
PubMed1992

Genetic disease patterns in Japan: a review.

Comprehensive genetic studies in which the genetic structure of a population is considered against the background of ecological factors, including environmental and social variables, often supply valuable information for the solution of a number of problems in human biology, including reproductive compensation and inbreeding depression. In the first section of this paper we consider the incidence of genetic diseases in Japan in reference to other populations. Some of the genetic disorders found elsewhere do not occur or are of lower frequencies in Japan. On the other hand, a number of genetic diseases occur at higher than usual frequencies, leading to an incidence of genetic disease of the order of about 1 per 100 in newborn Japanese. We next review the studies of consanguinity in Japan and report evidence of very high levels, ranging from 8.6% to 58.0%, for villages during the early part of the twentieth century. The rates are declining rapidly for the country but, because of traditional social values, inbreeding rates remain significant in many small villages. In the final section we consider the probable trends in the frequency of inbreeding on a worldwide basis and point out that frequencies of certain genetic diseases are likely to remain high and even increase in some societies because of various socially prescribed mating patterns.

Consanguinity↗
PubMed1991

Genetic polymorphism of human glutamate oxaloacetate transaminase (GOT1) detected using isoelectric focusing and a sensitive and positive staining method.

Genetic polymorphism of glutamate oxaloacetate transaminase (GOT1) was demonstrated in human erythrocytes by isoelectric focusing in thin layer polyacrylamide gels and a sensitive and positive detection method. Using this technique, five phenotypes, GOT1 1, 2, 2-1, 3-1 and 3-2 were determined and the estimated gene frequencies of GOT1*1, GOT1*2 and GOT1*3 in the Japanese population were 0.9740, 0.0173 and 0.0087, respectively.

Aspartate Aminotransferases↗
PubMed1991

[A case of neoplastic angioendotheliosis--possible mechanism of JC virus infection for the selective growth of tumor cells in the blood vessel].

A case of 55-year-old man pathologically proven as neoplastic angioendotheliosis was reported. He initially developed sensory disturbance and motor weakness in the lower extremities. After admission, he showed progressive deterioration of higher brain functions with moderate fever. Routine laboratory examinations revealed elevated serum LDH level and erythrocyte sedimentation rate without leukocytosis or increased serum globulin level. Immunological tests were normal, except positive RA. Immunocytochemical investigation of tumor cells in the blood vessel gave the results that these cells appeared to be derived from B cells. Southern blot analyses of the brain samples revealed clear positive bands corresponding to JC virus DNA in the blot. JC virus has been known to infect the endothelial cells of the blood vessel as well as urethral epithelial cells. We discussed the possible mechanism of the selective growth of tumor cells in the blood vessel in terms of possible JC virus infection to the endothelial cells of the blood vessel and abnormal recognition between tumor cells and endothelial cells.

B-Lymphocytes↗
PubMed1991

Transferrin polymorphisms in Japanese populations: north-south cline in the distribution of the TF*C2 allele.

Allele frequencies for human transferrin (TF) subtypes were determined using serum samples from Japanese subjects living in Fukui prefecture, Japan, and compared with other Japanese populations using isoelectric focusing (IEF) and immunoblotting. The application of IEF revealed considerable heterogeneity in the TF system, enhancing its potential value for anthropologic and genetic studies. So far, TF subtypes of about 27,000 Japanese individuals from 35 population groups have been analyzed to evaluate the degree of genetic variation at the TF locus. Possible geographic and biologic factors are discussed.

Alleles↗
PubMed1990

[Measurement of gamma-interferon in sera and CSF in patients with multiple sclerosis and inflammatory neurological diseases].

We examined whether gamma-interferon (gamma-IFN) can be detected in serum and CSF of patients with multiple sclerosis and other inflammatory neurological diseases. Gamma-IFN was assayed by solid phase radioimmunoassay on the forward sandwich principle. In 7 serum samples in acute stage of multiple sclerosis without corticosteroid, in 2 CSF samples in acute stage, gamma-IFN was not detected. In stable stage there was no case with positive gamma-IFN. The patient with tuberculous meningitis showed high titer in CSF but not in serum. One case with herpes zoster meningitis, one case out of 2 aseptic encephalitis showed positive gamma-IFN in CSF. In one case with Vogt-Koyanagi-Harada disease, gamma-IFN was detected both in serum and CSF. One case with Neuro-Behçet syndrome showed positive gamma-IFN in CSF. No gamma-IFN was detected in 2 cases with Guillain-Barré syndrome, one case with Crow-Fukase syndrome, Fisher syndrome, 2 cases with polymyosits. gamma-IFN in CSF was detected in meningitis and encephalitis, but not in serum. This suggests that the locally infiltrating cells produce gamma-IFN. However, we could not detect gamma-IFN in either CSF or serum of patients with multiple sclerosis. Negative results of gamma-IFN in patients with multiple sclerosis can be interpreted in 2 ways. 1. The half life of gamma-IFN is very short in vivo, and the level of gamma-IFN may not be detected at the time of sampling. 2. Generalized augmentation of gamma-IFN production may not be observed but locally infiltrating cells or astrocytes might produce gamma-IFN.(ABSTRACT TRUNCATED AT 250 WORDS)

Behcet Syndrome↗
PubMed1990

[Correlation between Campylobacter pylori and chronic atrophic gastritis].

The correlation between urease activity of Campylobacter pylori and atrophic gastritis was studied. On the basis of fundamental study on the optimal pH of C. pylori urease activity, urease activity of 38 biopsied specimens were measured under pH 5 condition, and compared with the positive ratio of C. pylori. In this study, sensitivity was 86.7%, and specificity was 87.0%, respectively. Mean urease activity of C. pylori positive specimens was 3.69 mIU/mg protein, and under this condition, C. pylori was likely to produce ammonia of 0.0218 mumole per minute, enough to damage the gastric mucosa. In addition, there was encountered high urease activity in the specimens which showed moderate glandular atrophy and severe mucosal inflammation. In conclusion, urea-urease-NH3 sequence is most likely to have some association with gastric glandular atrophy.

Campylobacter↗
PubMed1989

[Two cases of familial spastic paraparesis with amyotrophy of the hands].

Familial spastic paraparesis with amyotrophy of the hands was reported, and its significance in the literature was reviewed. Case 1: An 18 year-old boy, who had been suffering from spastic gait since 12 years old, noticed his hand muscle wasting distributed bilateral first interosseous muscle, thenar and hypothenar muscle at age 17. Case 2: A 20 year-old man, elder brother of case 1, who also walked in spastic manner from his childhood, developed bilateral hand muscle atrophy similar to case 1 at age 19. Clinical features of these two cases could be summarized as familial spastic paraparesis with amyotrophy characterized by hand muscle atrophy, spasticity of lower extremities with hyperreflexia and bilateral positive pathological reflexes and spastic gait. Their younger sister was also examined, who showed only minimal spastic paraparesis. The electrophysiological examination including EMG and SEP suggested the pathological process could involve not only lateral column, but also posterior column and anterior horn. Slight but generalized spinal cord atrophy was demonstrated on metrizamide CT myelography. The muscle biopsy performed from left gastrocnemius in case 2, confirmed neurogenic changes. Although the association of retinal degeneration, cataracta, mental retardation, pes cavus or even generalized amyotrophy has been reported in familial spastic paraparesis, only limited cases are available, dealing with the amyotrophy of limbs. As far the cases with amyotrophy localized to the hands are concerned, it is absolutely rare and only the cases reported by Silver could be regarded as similar or same clinical entities to our cases.

Adolescent↗
PubMed1988

Infection of human T-lymphotropic virus type I to astrocytes in vitro with induction of the class II major histocompatibility complex.

To clarify the pathogenesis of human T-lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM), we examined whether HTLV-I infects normal human glial cells in vitro with induction of the major histocompatibility complex (HMC) class II antigen by immunofluorescence method. It was found that about 10% of astrocytes were infected with HTLV-I with induction of class II MHC antigen. Fluorescence-conjugated HTLV-I was adsorbed to 10% of astrocytes. On the contrary, there was no class II MHC antigen expression and very few HTLV-I infection on oligodendrocytes. We speculated that in patients with HAM, HTLV-I-specific, MHC class II antigen restricted, activated CD4+ cells could damage the MHC class II antigen + HTLV-I-infected astrocytes, leading to the disturbance of blood-brain barrier and to the destructive lesion in the central nervous system.

Astrocytes↗
PubMed1988

Purification and characterization of human liver beta-galactosidase from a patient with the adult form of GM1 gangliosidosis and a normal control.

beta-Galactosidases were purified to homogeneity from livers of a normal control and a patient with the adult form of GM1 gangliosidosis. The purification was achieved by chromatography on DEAE-Sepharose fast flow, Con A-Sepharose, p-aminophenyl-1-thio-beta-D-galactopyranoside-Sepharose, and QAE-Mono Q. The normal and mutant enzymes were purified about 5000-fold with a yield of 10% and 1800-fold with a yield of 34%, respectively, and could hydrolyze 4-methylumbelliferyl-beta-D-galactoside, GM1 ganglioside, and asialofetuin. The purified normal enzyme was eluted from a TSK gel G-4000SW column as three symmetrical peaks of protein which were coincident with the three peaks of enzyme activity. The enzyme in these three peaks had apparent molecular weights of 800,000 (polymer), 140,000 (dimer), and 65,000 (monomer), whereas the mutant enzyme was eluted as two symmetrical peaks of protein and enzyme activity. The apparent molecular weight of a major monomeric form of the enzyme (beta-galactosidase A) was 60,000, and no dimeric form of the enzyme existed. Normal and mutant purified enzyme preparations migrated as a single major protein band with apparent molecular weights of 65,000 or 60,000, respectively, by SDS-polyacrylamide gel electrophoresis after treatment with mercaptoethanol. On isoelectric focussing, the mutant enzyme migrated more anodally than the normal enzyme. The mutant enzyme also had altered enzyme properties, such as pH optimum, Km values, substrate specificity and heat-stability. These data on the characteristics of the purified enzyme preparations provide the first direct evidence that patients with the adult form of GM1 gangliosidosis have a structurally altered beta-galactosidase.

Adult↗
PubMed1988

[Blood polymorphism in the study of isolated communities].

Isolated communities offer a unique opportunity for the study of biological and social consequences of consanguinity and migration. The studies of genetic polymorphisms have contributed greatly, not only to knowledge of the genetic constitution of a given individual and population, but also to clarify either relationship between structure and function of polymorphic traits or the susceptibility to multifactorial diseases, in which interaction between the gene and environment cannot be ignored. For over 25 years, we have investigated the effect of consanguinity and genetic polymorphisms in 9 isolated communities in Western Japan. We reported here different values of gene frequency for each polymorphic trait, compared with the neighboring communities and described how we applied these data to clarification of the genetic constitution of isolated communities as well as of genetic susceptibility to some diseases.

Anemia, Aplastic↗
PubMed1988

Clinical significance of immunoglobulin A antibody to hepatitis B core antigen of polymeric and monomeric forms in chronic type B liver disease with acute exacerbation.

Serum immunoglobulin A (IgA) hepatitis B core antibody (anti-HBc) was measured by a solid-phase enzyme immunoassay using monoclonal antibodies in sera from chronic carriers of hepatitis B surface antigen (HBsAg). To reinforce the clinical significance of IgA anti-HBc, levels of IgA subclasses and molecular characterization of IgA anti-HBc in sera of 13 patients in the acute exacerbation phase and the remission phase were compared. IgA anti-HBc was significantly higher in sera in the acute exacerbation phase than in the remission phase (p less than 0.025); in particular, more significant changes were observed in IgA2 anti-HBc (p less than 0.0025) and in secretory IgA anti-HBc (p less than 0.001). Analysis of molecular size distribution of IgA anti-HBc by high performance liquid chromatography showed that the elevation of polymeric IgA anti-HBc was significantly greater than that of monomeric IgA anti-HBc in the acute exacerbation phase (p less than 0.05), although there was an increase in both monomeric and polymeric IgA anti-HBc. Thus, the elevation of polymeric IgA anti-HBc suggests that the focal immune response against HBcAg in the liver and secretory IgA anti-HBc is an important marker of acute exacerbation in patients with HBsAg-positive chronic liver disease.

Carrier State↗