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Biomedical subjects

M Fujimoto

Publications and source records attributed to M Fujimoto.

At least 289 records · Page 16Linked to original sources
PubMed1995

[A case of bilateral upper medial medullary infarction].

A clinical case of bilateral upper medial medullary infarction was reported. A 61-year-old woman was admitted to our hospital because of numbness of trunk and bilateral upper and lower limbs, aphonia and left-hemiparesis, which progressed to quadriplegia. Facial movements were intact. Her tongue was not fully protruded and deviated to the right side. Impairment of the position sense was noted in bilateral lower limbs. Respiratory failure was not observed. A brain MRI revealed a high-intensity area on T2-weighted imaging in the upper medulla oblongata. The lesion involved the medial medulla oblongata bilaterally. No lesions were present in the other brain parenchyma. According to the literature, respiratory failure was present in almost all patients with bilateral medial medullary infarction. The findings of our patient suggest that respiratory failure is not induced by the bilateral medial medullary infarction limited to the upper medulla oblongata.

Cerebral Infarction↗
PubMed1994

Growth hormone and insulin-like growth factor I induce immunoglobulin (Ig)E and IgG4 production by human B cells.

We studied the effects of growth hormone (GH), insulin-like growth factor I (IGF-I), IGF-II, and insulin on human immunoglobulin E (IgE) and IgG4 production. GH and IGF-I induced IgE and IgG4 production by normal donors' mononuclear cells (MNC) depleted of sIgE+ and sIgG4+ B cells without affecting IgM, IgG1, IgG2, IgG3, IgA1, or IgA2 production, whereas IGF-II and insulin failed to do so. GH-induced IgE and IgG4 production was specific, and was not mediated by IGF-I, interleukin 4 (IL-4), or IL-13, since it was blocked by anti-GH antibody (Ab), but not by anti-IGF-I Ab, anti-IL-4 Ab, or anti-IL-13 Ab. Conversely, IGF-I-induced IgE and IgG4 production was blocked by anti-IGF-I Ab, but not by anti-GH Ab, anti-IL-4 Ab, or anti-IL-13 Ab. Moreover, interferon alpha (IFN-alpha) or IFN-gamma, which counteracted IL-4-and IL-13-induced IgE and IgG4 production, had no effect on induction by GH or IGF-I. In contrast to MNC, GH or IGF-I failed to induce IgE and IgG4 production by purified sIgE-, sIgG4- B cells. However, in the presence of anti-CD40 monoclonal antibody (mAb), GH or IGF-I induced IgE and IgG4 production by these cells. Purified sIgE+, but not sIgE-, B cells from atopic patients spontaneously produced IgE. GH or IGF-I with anti-CD40 mAb failed to enhance IgE production by sIgE+ B cells, whereas they induced IgE production by sIgE- B cells. Similarly, whereas GH or IGF-I with anti-CD40 mAb failed to enhance IgG4 production by sIgG4+ B cells from atopic patients, they induced IgG4 production by sIgG4- B cells. Again, neither IgE nor IgG4 induction was blocked by anti-IL-4 Ab or anti-IL-13 Ab. These results indicate that GH and IGF-I induce IgE and IgG4 production by class switching in an IL-4- and IL-13-independent mechanism.

B-Lymphocytes↗
PubMed1994

Y2 receptors for neuropeptide Y are coupled to three intracellular signal transduction pathways in a human neuroblastoma cell line.

Neuropeptide Y (NPY) attenuated angiotensin II (AII)-or bradykinin (BK)-induced Ca2+ release from intracellular stores and inhibited forskolin-stimulated cAMP accumulation and omega-conotoxin-sensitive high K(+)-induced Ca2+ influx in the human neuroblastoma cell line SMS-KAN. All three NPY actions were mediated via Y2 receptors. Pretreatment with pertussis toxin completely abolished all of the NPY actions. Activation or down-regulation of protein kinase C had no effect on any NPY-mediated effect; herbimycin A, a tyrosine kinase inhibitor, only abolished the inhibitory effect of NPY on AII- or BK-induced Ca2+ mobilization. Herbimycin A also blocked platelet-derived growth factor-induced Ca2+ mobilization, which involves tyrosine kinase activation, and there was a good correlation in the concentration dependency between the two effects of herbimycin A, strongly suggesting that its ability to cancel the NPY effect is due to inhibition of tyrosine kinase activity. NPY attenuated AII- or BK-induced inositol 1,4,5-trisphosphate production, and herbimycin A reversed this NPY effect. These results provide the first evidence that Y2 receptors negatively couple to AII- or BK-induced phosphoinositide turnover leading to Ca2+ mobilization through pertussis toxin-sensitive GTP-binding protein(s). Inhibition of phospholipase C-beta activity by NPY seems to be mediated by activation of protein-tyrosine kinase or phosphotyrosine-containing protein(s).

Angiotensin II↗
PubMed1994

Vasoactive intestinal peptide specifically induces human IgA1 and IgA2 production.

The effects of vasoactive intestinal peptide (VIP) on human IgA1 and IgA2 production were studied. In unfractionated small resting B cells stimulated with anti-CD40 monoclonal antibody (mAb), VIP induced IgA1 and IgA2 production without affecting the production of IgG1, IgG2, IgG3, IgG4, IgM, or IgE. When small B cells were separated into sIgA1+, sIgA2+, sIgA1- and sIgA2- B cells, anti-CD40 mAb plus VIP induced IgA1 and IgA2 production by surface IgA1- (sIgA1-) and sIgA2- B cells, respectively, while having no effect on sIgA1+ and sIgA2+ B cells. This induction by VIP was specific, since anti-CD40 mAb plus other neuropeptides, i.e., somatostatin or substance P, had no effect, and moreover, the induction was specifically blocked by a VIP antagonist. Further, anti-CD40 mAb plus various cytokines, including interleukin (IL)-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, transforming growth factor-beta, low molecular weight B cell growth factor, and interferon-gamma, did not induce IgA1 and IgA2 production by sIgA1- and sIgA2- B cells, respectively. These results indicate that in the presence of anti-CD40 mAb, VIP induces IgA1 and IgA2 production by isotype switching.

Antibodies, Monoclonal↗
PubMed1994

Histamine inhibits immunoglobulin production via histamine H2 receptors without affecting cell growth in human B cells.

The effect of histamine upon immunoglobulin (Ig) production and proliferation in human B cells was studied. Histamine inhibited Ig production by the human B cell lines IM-9 and CBL in a dose-dependent fashion during 4 days of culture. As little as 10(-5) M was inhibitory. In contrast, proliferation was not affected. Inhibition by histamine was blocked by histamine H2 antagonist, cimetidine, but not by histamine H1 antagonist, diphenhydramine. Moreover, histamine H2 agonist dimaprit inhibited Ig production from B cell lines in a dose-dependent manner, and as little as 10(-8) M was inhibitory. Histamine also inhibited IgM and IgG production by peripheral and tonsillar B cells stimulated with Staphylococcus aureus Cowan strain I and IL-2 without affecting proliferation. This inhibition was also blocked by cimetidine. These results indicate that histamine has a direct inhibitory effect on B cells via histamine H2 receptors, and acts as an immunoregulatory factor.

B-Lymphocytes↗
PubMed1994

Memory deficit accompanying cerebral neurodegeneration after stroke in stroke-prone spontaneously hypertensive rats (SHRSP).

Memory performances of SHRSP with chronic stroke were examined on the three-panel runway task in addition to the histological evaluation and magnetic resonance imaging (MRI) of the brain. After recovery from the neurological symptoms with stroke. SHRSP were subjected to acquisition training on the memory tasks, and they exhibited both a delay and a persistent impairment of acquisition on the memory tasks, compared to the non-stroke SHRSP. T2-weighted MRI with the stroke SHRSP suggested marked edematous formation in the cortex, caudate putamen and/or thalamus, preferentially in the frontal and/or occipital cortex. The histological evaluation showed edematous degeneration such as edema, gliosis and cyst preferentially in the cortex, but no degeneration in the hippocampus. Thus, SHRSP with chronic stroke was found to exhibit impairment of learning and memory, which may be due to the cortical edematous degeneration.

Animals↗
PubMed1994

Effect of simple shear flow on photosynthesis rate and morphology of micro algae.

The convective motion of micro algal suspension gives an advantageous effect on the photosynthetic rate in the bioreactor, however, the nature of convective effect on the photosynthesis has not been fully understood. The purpose of this study concerns the nature of photosynthetic rate in a well-defined hydrodynamic shear flow of Spirulina platensis suspension, generated in a double rotating coaxial cylinders. The double rotating coaxial cylinders was installed in the incubator chamber with the controlled illumination intensity and temperature. Two kind of experiments, short and long term experiments, were performed to evaluate the direct effect of shear flow on the photosynthetic rate. The short term experiment indicates that the simple shear flow enables to augment the photosynthesis of Spirulina suspension and simultaneously causes the cell destruction due to the excessive shear stress. The long term experiment for 100 hours reveals that the growth rate and the morphology of Spirulina is sensitive to the external fluid mechanical stimulus. The long term application of mechanical stress on the algae may result in the adaptation of the photosynthetic function and morphology.

Bioreactors↗
PubMed1994

Properties of the 'neutral zone' explain polarity of retinal spreading depression.

Retinal spreading depression was evoked using low Cl- Ringer's solution and the concomitant field potentials (spreading depression potential; SDP) were recorded. The polarity of the transretinally recorded SDPs was not consistent among animal species. The SDPs recorded from carp and frog were receptor side negative, while chick and cat induced receptor side positive SDPs. According to the K+ hypothesis, the retinal SDP is generated by Müller cells responding to an increase in the extracellular K+ concentration in the inner plexiform layer. In order to clarify the relationship between the K+ increase and the polarity of the SDP, a high-K+ solution was injected at various retinal depths and the evoked potential was recorded transretinally. The neutral zone within the retina, where a change in the extracellular K+ concentration produces no net potential difference, was revealed to be near the proximal end of the retina in carp and frog, while it was located distal to the inner plexiform layer in the chick and cat. These results support the Müller cell K+ hypothesis and explain the polarity of SDPs. We conclude that the concept of the neutral zone is valuable for the investigation of the mechanism and polarity of transretinal field potentials.

Animals↗
PubMed1994

Clinical characteristics associated with antihistone antibodies in patients with localized scleroderma.

BACKGROUND: Recently we demonstrated the presence of antihistone antibodies (AHA) in localized scleroderma. OBJECTIVE: Our purpose was to determine clinical characteristics associated with AHA in patients with localized scleroderma. METHODS: We examined 57 serum samples by an enzyme-linked immunosorbent assay in the following three subgroups: 15 patients with generalized morphea, 27 with linear scleroderma, and 15 with morphea. We classified the patients as having generalized morphea when they had four or more lesions on at least two areas of the body, irrespective of whether the lesions were of morphea or linear type. RESULTS: AHA were detected in 42% of patients with localized scleroderma (24 of 57), and in 87% of patients with generalized morphea (13 of 15). The presence of AHA strongly correlated with the number of morphea lesions, the total number of lesions, and the number of involved areas of the body. However, AHA did not correlate with the presence or number of linear lesions. The presence of AHA showed a 87% sensitivity (13 of 15 patients) and a 74% specificity (31 of 42 patients) for generalized morphea. CONCLUSION: Our data suggest that AHA are a serologic marker for generalized morphea and that the validity of our new classification for generalized morphea is supported by the high frequency of AHA detection.

Adolescent↗
PubMed1994

Increased levels of circulating intercellular adhesion molecule-1 in patients with localized scleroderma.

BACKGROUND: Intercellular adhesion molecule-1 (ICAM-1) is important in immune-mediated mechanisms, and its circulating form (cICAM-1) may be an indicator of immune activation. Localized scleroderma is accompanied by various immunologic abnormalities. OBJECTIVE: We investigated whether the serum level of cICAM-1 in patients with localized scleroderma was elevated and was correlated with the clinical or serologic features of this disease. METHODS: Serum cICAM-1 levels were determined by an enzyme-linked immunosorbent assay in 48 patients with localized scleroderma, in 20 patients with systemic sclerosis, and in 20 healthy control subjects. RESULTS: Serum levels of cICAM-1 were significantly higher in patients with localized scleroderma than in the healthy control subjects. These levels correlated with the number of lesions, the number of involved areas, levels of antihistone antibody IgM, and levels of soluble interleukin 2 receptor. CONCLUSION: The results suggest that immune activation may be a factor in localized scleroderma.

Adult↗
PubMed1994

Expression of leukemia inhibitory factor in human endometrium and placenta.

Leukemia inhibitory factor (LIF), a cytokine that induces macrophage differentiation in the murine M1 myeloid leukemia cell line, is essential for blastocyst implantation in mice. However, its expression and the role it plays in the human uterus are unknown. To clarify these issues, we examined LIF gene expression in the human uterus by Northern blot hybridization and by a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method. Analysis of LIF mRNA showed two hybridization bands, with estimated mRNA sizes of about 4.0-kb pairs and 1.8-kb pairs. LIF mRNA was detected at high levels in endometrial tissue and decidua, but at low levels in the chorionic villus in first trimester and term placenta. In the secretory phase, the endometrial tissue showed higher LIF expression than in the proliferative phase (9.5-fold; p < 0.01). The endometrial tissues were separated into a stroma-enriched fraction (SF) and an epithelium-enriched fraction (EF), and the LIF mRNA levels in each fraction were examined by quantitative RT-PCR. These levels were higher in the EF than in the SF (3.3-fold; p < 0.05). These findings suggest that, in humans, LIF plays a role in uterine function during the menstrual cycle, as well as during pregnancy.

Base Sequence↗
PubMed1994

Antibodies to centromere and centriole in scleroderma spectrum disorders.

The importance of early detection of scleroderma spectrum disorders (SSD) has been emphasized. We determined the clinical distribution of anticentromere antibody (ACA) and anticentriole antibody in the following four groups: (1) 264 patients with SSD, including 193 with systemic sclerosis, 29 with mixed connective tissue disease and 42 with suspected secondary Raynaud's phenomenon (RP); (2) 26 patients with primary RP; (3) 248 patients with other connective tissue diseases, and (4) 139 patients with other skin diseases. The frequency of ACA was significantly higher in SSD (78/264, 30%) than in the other groups. In patients with SSD, the incidence of ACA in suspected secondary RP (28/42, 67%) was similar to that in type I systemic sclerosis (24/36, 67%). Anticentriole antibody was detected in only 1 patient with suspected secondary RP (0.4%) out of the 264 SSD patients. These data indicate that anticentriole antibody is very rare and that the antibodies against mitosis-related antigens such as centromere and centriole are associated with early SSD.

Adult↗
PubMed1994

Progesterone enhances macrophage colony-stimulating factor production in human endometrial stromal cells in vitro.

Increasing evidence suggests that macrophage colony-stimulating factor (M-CSF) is produced in the uterine endometrium and that it plays an important role in the reproductive process. In the present study, using an in vitro decidualization model and human endometrium, we investigated M-CSF messenger RNA (mRNA) expression in human endometrial stromal cells (ESC) by Northern blotting and in situ hybridization. The secreted M-CSF in the culture medium of ESC was measured by enzyme-linked immunosorbent assay. ESC were cultured in the presence of progesterone (P) or estrogen. After a 9-day culture with P, when in vitro decidualization was confirmed by the production of PRL, M-CSF mRNA and protein levels were 3.1 +/- 0.5- and 3.2 +/- 0.8-fold (mean +/- SEM) higher, respectively, than those in cultures without P (P < 0.01). The P-induced increase was dose dependent. On the other hand, estrogen did not increase M-CSF mRNA expression. M-CSF mRNA expression in the first trimester deciduae that expressed PRL mRNA was higher than that in the endometria. By in situ hybridization, ESC as well as epithelial cells were shown to express M-CSF both in vitro and in vivo. These findings indicate that human ESC (decidua cells) express M-CSF mRNA and suggest that they secrete M-CSF in a P-dependent manner during the process of decidualization.

Adult↗
PubMed1994

Thrombotic obstruction of the right coronary artery in a postoperative patient with Bland-White-Garland syndrome.

A 53-year-old female presented with symptoms of severe chest and back pain associated with oliguria. The patient had a history of exertional dyspnea since the age of 20, and easy fatigability since the age of 27. At the age of 41, she noted marked exacerbation of these symptoms after suffering from a cold and was ultimately diagnosed as having Bland-White-Garland (BWG) syndrome with mitral valve regurgitation. The patient then underwent re-implantation of an anomalous left coronary artery from the pulmonary artery to the posterolateral wall of the aorta. Eleven years later, she re-presented with symptoms of angina and congestive heart failure. Coronary angiography was subsequently performed and a total occlusion of the right coronary artery with probable thrombus was revealed. The right coronary artery was filled via collaterals from the implanted left coronary artery. Mitral regurgitation was noted during angiography. The patient underwent aorto-coronary artery bypass grafting of the right coronary artery and concomitant mitral valve replacement. Her postoperative condition remained excellent.

Coronary Angiography↗
PubMed1994

Computer generated three-dimensional reconstruction of the bony labyrinth in Mondini's dysplasia.

The bony labyrinth obtained at necropsy in four cases was studied by a new computer-generated three-dimensional (3-D) system. One case was normal (control) and the other three were histopathologically confirmed cases of Mondini's dysplasia. In case 1, the cochlea had only 2 turns and the lateral semicircular canal did not make a circle but appeared as a spherical mass projecting from the utricle even though the posterior semicircular canal made a normal circle. In case 2, there were no turns in the cochlea even though the semicircular canals and the vestibule appeared normal. In case 3, the cochlea showed 1 to 1 and 1/2 turns and the semicircular canals were premature showing only bud-like projections. This 3-D imaging system, which utilizes the toggling method, provides a way of obtaining satisfactory images without markers, and the time required to obtain these 3-D images was reduced by using a video camera instead of a digitizer. One of the problems associated with the use of 3-D imaging is the long processing time. We resolved this by inputting the section images with a video camera and by picking up structures using density segmentation instead of tracing with a digitizer.

Child, Preschool↗
PubMed1994

Color Doppler sonography of hepatic tumors with a galactose-based contrast agent: correlation with angiographic findings.

OBJECTIVE: The purpose of this study was to evaluate the clinical usefulness of a galactose-based, IV sonographic contrast agent for assessing tumor vascularity and diagnosing hepatocellular carcinoma. SUBJECTS AND METHODS: We used color Doppler sonography with the sonographic contrast agent to examine 22 patients with 26 hepatic nodules (18 hepatocellular carcinomas, four hemangiomas, two adenomatous hyperplasias, and two metastatic tumors). In all 26 lesions, intratumoral arterial flow signals were examined before and after IV injection of the sonographic contrast agent at three concentrations (200, 300, and 400 mg/ml), and the findings on color Doppler sonograms of each lesion were correlated with angiographic findings. RESULTS: Conventional color Doppler sonograms showed flow in nine hepatocellular carcinomas (50%) and one hemangioma (25%). When the contrast agent was used, color Doppler sonograms showed intratumoral arterial flow in 11 hepatocellular carcinomas (61%) and one hemangioma (25%) at a concentration of 200 mg/ml, in 14 hepatocellular carcinomas (78%) and 1 hemangioma (25%) at 300 mg/ml, and in 15 hepatocellular carcinomas (83%) and two hemangiomas (50%) at 400 mg/ml. The detectability of intratumoral arterial flow was improved by the contrast agent, especially in hepatocellular carcinomas smaller than 30 mm in diameter. Angiography revealed neovascularization or staining in 15 hepatocellular carcinomas, four hemangiomas, and none of the adenomatous hyperplasias or metastatic tumors. Among 15 angiographically hypervascular hepatocellular carcinomas, the detection rate of intratumoral arterial flow with contrast-enhanced color Doppler sonography was 73% at 200 mg/ml, 93% at 300 mg/ml, and 100% at 400 mg/ml. No intratumoral Doppler signals were depicted with the use of contrast agent in any angiographically undetected tumors. CONCLUSION: Preliminary findings on contrast-enhanced color Doppler sonograms correlate well with angiographic findings for evaluating tumor vascularity. This noninvasive technique may be useful in diagnosing hypervascular hepatocellular carcinomas.

Adenoma↗
PubMed1994

Antigen specificity of antihistone antibodies in localized scleroderma.

BACKGROUND AND DESIGN: Recently, we detected antihistone antibodies (AHAs) in patients with localized scleroderma. However, the exact antigen specificity of AHAs in this disease is still unknown. Therefore, we determined the reactivity of AHAs with five individual histones and the correlation of AHAs with rheumatoid factor in localized scleroderma by means of enzyme-linked immunosorbent assay. Twenty patients with localized scleroderma who had IgG and/or IgM AHAs, as determined by enzyme-linked immunosorbent assay, were examined. These patients were classified into the following three subgroups: patients with generalized morphea (n = 11), patients with linear scleroderma (n = 6), and patients with morphea (n = 3). RESULTS: In generalized morphea, IgG AHAs strongly reacted with histones H1, H2A, and H2B; and IgM AHAs strongly reacted with H1 and H2B, as determined by means of enzyme-linked immunosorbent assay. The pattern of reactivity in linear scleroderma and morphea was similar to that in generalized morphea. A homogeneous immunofluorescent pattern on HEp-2 cells, which was produced by localized scleroderma sera, was completely abolished by absorption with total histones. By employing a latex agglutination test, IgM rheumatoid factor was detected in 60% of the 20 patients with localized scleroderma and at a frequency of 82% in those with generalized morphea. However, an absorption test of rheumatoid factor activity with human IgG revealed no cross-reactivity of AHAs with rheumatoid factor. CONCLUSIONS: Our data suggest that AHAs in localized scleroderma are directed against native chromatin, since H1, H2A, and H2B occupy a relatively exposed portion of chromatin.

Adolescent↗