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Biomedical subjects

S Fujimoto

Publications and source records attributed to S Fujimoto.

At least 433 records · Page 24Linked to original sources

Histamine release from Weibel-Palade bodies of toad aortas induced by endothelin-1 and sarafotoxin-S6b.

BACKGROUND: Endothelin-1 (ET-1) and sarafotoxin-S6b (STX) induce a remarkable degranulation of Weibel-Palade (WP) bodies prior to the vasocontraction of toad aortas. As WP bodies play the role of a reservoir site of the histamine in the endothelial cells, there is the possibility that ET-1 and STX evoke the release of histamine from WP bodies of this vessel. METHODS: Histamine concentrations were assayed by high-performance liquid chromatography (HPLC) from the perfusate after being perfused with a solution containing ET-1 and STX. Each vessel was fixed and embedded for conventional electron microscopy and immunoelectron microscopy using antihistamine sera. RESULTS: The appreciable concentrations of histamine were assayed by HPLC from the perfusate after the toad aortas were perfused with a solution containing ET-1 and STX. The immunoelectron microscopy revealed that histamine immunoreactive gold particles in the WP bodies remarkably decreased in number in the treated samples when compared to the control ones. Our immunoelectron micrographs indicated that the release of histamine from the endothelial cells occurred in association with the degranulation and the exocytosis of the WP bodies after treatment with ET-1 and STX. CONCLUSIONS: The present study clearly shows that ET-1 and STX induce the histamine release from WP bodies of the toad aortas by means of HPLC and immunoelectron microscopy. Histamine discharged from the WP bodies may be involved in the vasocontraction evoked by ET-1 and STX.

Animals↗

Rapid diagnosis of premature rupture of membranes using a new kit employing anti-AFP monoclonal antibody.

A kit using mouse monoclonal antibody against human alpha-fetoprotein (anti-AFP kit) has been developed. Cervical secretion (n = 34) and vaginal fluid (n = 15) was obtained from 30 pregnant volunteers. All 31 specimens obtained from women with intact membranes tested negative while all 18 specimens from women with premature rupture of membranes (PROM) tested positive. The newly developed kit allowed rapid and accurate diagnosis. We compared the kit results with those obtained by pH determination (nitrazine, bromthymol blue test) and measurement of AFP concentrations by enzyme-linked immunoassay (EIA).

Adult↗

Biologic activity of human papillomavirus type 16 E6/E7 cDNA clones isolated from SiHa cervical carcinoma cell line.

Three species of E6/E7 cDNAs of human papillomavirus type 16 (HPV16) for the full-length E6/E7 and spliced E6*I/E7 and E6*II/E7 mRNAs were synthesized by reverse transcriptase-(RT-)PCR from RNA of the cervical carcinoma cell line SiHa. Two cDNA mutants carrying point mutations in either a splice donor site or acceptor site within the E6 open reading frame were also constructed. These HPV16 E6/E7 cDNAs were cloned under the SV40 enhancer/promoter and the MMTV LTR to examine the activities of ras-collaborative transformation and induction of cellular DNA synthesis, both of which depend on the E7 gene product. The E6*II/E7 cDNA and two mutated cDNAs deficient in the spliced mRNA transcription showed lower levels of both activities than the full-length E6/E7 and the E6*I/E7 cDNA. The rat cell lines carrying each of the E6/E7 cDNAs contained the E6/E7 mRNA species expected. A small amount of E6*I/E7-sized mRNA was transcribed from a splice-donor site mutant of the E6/E7 cDNA, which turned out to be a transcript derived from a cryptic splice donor site six bases upstream from the conventional site. Among NIH3T3 cells carrying one of the above-mentioned E6/E7 cDNAs, the cells expressing E6*I/E7 mRNA [cells carrying cF(wt) and c*I] produced an amount of E7 protein comparable with those carrying the E7 or E6E7 region. These results suggest that the E6*I/E7 is the mRNA that is important for the efficient expression of E7 product from the HPV16 E6/E7 region.

3T3 Cells↗

Magnetic resonance velocity mapping of normal human transmitral velocity profiles.

We used magnetic resonance imaging (MRI) velocity mapping to assess the velocity profile of early diastolic mitral inflow in 11 normal subjects. Velocity maps of left ventricular inflow were obtained in the horizontal long axis of the left ventricle at the time of peak early diastolic filling. Velocity profile curves across the mitral inflow were obtained at 1-cm intervals from the mitral ring to 4 cm into the cavity. The jet width was 3.06 +/- 0.64 cm at the mitral ring level, increasing to 3.6 +/- 0.61 cm at 4 cm. The peak/mean velocity was 1.2 +/- 0.07 at the mitral ring and increased to around 1.4 at 3-4 cm from the mitral ring. The point at which the peak velocity was recorded at each level was skewed towards the septal side by 10%-13% of jet width from the center at the mitral ring and 2-4 cm from the ring. However, at a depth of 1 cm, corresponding to the mitral tip level, the peak velocity was at the center of the jet. The ratio of vertical and horizontal dimensions of the jet cross section was 1.11 +/- 0.05. Thus, the mitral inflow velocity profile is relatively flat at the mitral ring and tip level; the inflow jet cross section is effectively circular.

Adolescent↗

Detection and localization of early diastolic forces within the left ventricle from inflow jet dynamics. A comparison between normal subjects and patients with dilated cardiomyopathy.

We studied the properties of the jet of blood entering the left ventricle from the left atrium during early diastole in 32 patients with dilated cardiomyopathy, and 24 normal subjects of similar age. The diameter of the jet was measured from the cross-sectional color Doppler image and its cross-sectional area (JA) was derived. Pulsed Doppler records of flow velocity were made at 1-cm intervals into the ventricle from the mitral ring. Peak (Vp) and mean (Vm) E wave velocity and time velocity integral (TVI) were determined. At any level in the ventricle, therefore, the early diastolic volume of blood remaining in the jet, i.e., the flow time integral, is given by JA.TVI; the local flow rate, Q, by JA.Vm; and jet momentum along the long axis of the ventricle by Q.Vp. In normals, the jet cross-sectional area fell from 5.9 (1.3) cm2 at the mitral ring to 4.9 (0.7) cm2 at 4 cm (P < 0.05), but the flow time integral fell proportionately more, from 46.0 (15.2) ml at the ring level to 15.9 (3.4) ml at 4 cm (P < 0.01). Axial momentum flux was 44 (13) x 10(2) cm4s-2 at the ring level, falling to 28 (10) x 10(2) cm4s-2 at 4 cm (P < 0.01). In dilated cardiomyopathy, the jet cross-sectional area was much smaller than normal, 1.9 (0.8) cm2 at the ring level, and it remained effectively constant, being 2.0 (0.9) cm2 at 6 cm (P < 0.01 vs normals).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Primary biliary cirrhosis complicated by severe hypoxemia.

The case reported here is of a 61-year-old woman diagnosed with hepatopulmonary syndrome. She had had severe hypoxemia for 5 years. In room air, her arterial oxygen tension was low, and although we anticipated that treatment with oxygen would increase it, the treatment failed to do so. Pulmonary perfusion imaging with Tc-99m-labelled macroaggregated albumin showed an arterio-venous shunt in the lungs. Blood tests and liver scanning with Tc-99m-labelled galactosyl human serum albumin showed abnormalities of liver function, and per-rectal portal scintigraphy with Tc-99m pertechnetate showed severe portal hypertension. Inspection of a biopsy specimen taken under ultrasonographic guidance showed primary biliary cirrhosis of Scheuer stage I. The causes of hepatopulmonary syndrome are unknown, but seem to include a decrease in hepatic functional reserve, portal hypertension, or other factors. The development of hepatopulmonary syndrome due to portal hypertension in this patient is of interest.

Biopsy↗

Southern blotting analyses of strains of Campylobacter fetus using the conserved region of sapA.

Chromosomal DNA of 27 strains of Campylobacter fetus was analyzed by Southern blotting with a probe of the conserved region of sapA. The probe hybridized with 23 strains that produced type A lipopolysaccharide. These strains had more than six sapA homologs. In Southern blots of SalI-digested chromosomal DNA separated by pulsed-field gel electrophoresis, one fragment from 19 strains and two fragments from 4 strains hybridized. These data indicate that multiple sapA homologs are localized to a limited region on the chromosomal DNA of C. fetus and thus suggest the possibility of developing a typing system using this method.

Bacterial Proteins↗

Fetal fibronectin concentration in amniotic fluid decreases with advancing gestational age.

OBJECTIVE: The purpose of this study was to investigate the changes in the level of fetal fibronectin in amniotic fluid during the course of pregnancy. METHOD: Amniotic fluid samples were obtained from 74 women whose pregnancies ranged in gestation from 14 to 38 weeks. Fetal fibronectin in amniotic fluid was examined with a sensitive immunoassay using a monoclonal antibody FDC-6 which recognizes a unique epitope (III-CS) of the molecule. RESULTS: Fetal fibronectin levels in amniotic fluid decreased significantly during pregnancy (r = -0.79, P < 0.0001). The mean levels at less than 20 weeks of gestation were significantly higher than those at 20-29 weeks (P < 0.0001) and at 30 weeks to term (P < 0.0001). CONCLUSION: These results must be considered when fetal fibronectin in vaginal fluid is used as an indicator of the rupture of membranes.

Adult↗

Putative mechanism for guinea pig ileum contraction by N-formyl peptides. A comparative study of N-formyl and N-acetyl peptides with the N-terminal sequence of the calpain small subunit.

N-formyl and N-acetyl peptides with the N-terminal sequence of the calpain small subunit were prepared and their spasmogenic activity was examined using guinea pig ileum preparations. Sections of ileum were found to contract in the presence of all N-formyl peptides used (tri- to nonapeptides and tridecapeptide) but failed to contract with N-acetyl peptides, although both N-formyl and N-acetyl peptides have chemotactic activity, indicating that spasmogenic activity and chemotactic activity involve different mechanisms. A formyl peptide antagonist, Boc-Phe-Leu-Phe-Leu-Phe, suppressed contraction by formyl peptides whereas a histamine antagonist, diphenhydramine, suppressed contraction by formyl peptides as well as by histamine. In addition, formyl peptide-induced contractions were noted after an approximately 20-sec time lag, and their profiles were bell-shaped and roughly symmetrical. On the other hand, histamine- and acetylcholine-induced contractions exhibited a much shorter time lag. These data led us to conclude that contraction induced by formyl peptides may not occur as a direct response but may be due to the histamine released from mast cells present in the tissues of the small intestine.

Amino Acid Sequence↗

Diagnosis of preterm premature rupture of the membranes using a newly developed AFP monoclonal antibody test kit.

OBJECTIVE: We have developed a new anti-AFP monoclonal antibody kit which is easier to use than other examination methods for detecting AFP in the leaked amniotic fluid. In this study, we investigate the clinical value of this test in the diagnosis of preterm premature rupture of the membranes (PROM). METHODS: We employed 103 patients of less than 37 weeks of gestational age for this preliminary study. We compared the clinical usefulness of this new AFP test with that of the nitrazine test and measured the concentration of AFP in vaginal fluid or cervical secretion by EIA. RESULTS: The nitrazine test showed a correct diagnostic rate of 62.1%, in contrast the AFP test kit had a 98.0% rate (P < 0.001). The reaction time using the kit is 3 min. CONCLUSION: The AFP test is a simple and non-invasive test which can be easily carried out repeatedly as a bedside examination. This study has confirmed the high clinical efficacy of the newly developed AFP test kit as a method of PROM diagnosis.

Amniotic Fluid↗

Malignant trophoblastic neoplasms with different modes of origin.

The genetic origin of 24 trophoblastic neoplasms was determined using PCR polymorphisms. Based on pregnancy history, these tumors included nine postmolar trophoblastic tumors, 12 tumors preceded by live birth or abortion, and three nongestational tumors. Androgenetic origin was defined in eight post-molar trophoblastic tumors, and the remaining one might have arisen from a normal fertilization. Six tumors retained genetic features carried by the homozygous complete mole. Two tumors showed PCR polymorphism compatible with that of the heterozygous complete mole. All 12 tumors in the second class had alleles of both paternal and maternal contribution. However, discordance of sex between the antecedent pregnancy product and the tumor was recognized in three choriocarcinomas. The absence of paternal contribution suggested a parthenogenetic origin of three nongestational choriocarcinomas. The findings that PCR polymorphisms were either homozygous in certain loci or heterozygous in others may mean that the tumor was derived from a germ cell after meiosis I. As a result, at least three subtypes with different modes of origin were demonstrated in the 24 trophoblastic tumors. These findings underscore the importance of precise genetic marker analyses in a large series to clearly identify clinical and biologic characteristics of each subset of tumors.

Base Sequence↗

Differentiation of the rat stria vascularis.

The differentiation of the rat stria vascularis (SV) was investigated by light- and electron microscopy and by immunocytochemistry. Loss of the basal lamina at the epithelial-mesenchymal interface of SVs as indicated by immunoreactions of laminin and fibronectin induces the formation of vascular feet by basal infoldings of the marginal cells (MCs), and the development of the strial capillaries (SCs) by mesenchymal cells in a manner of vasculogenesis is progressing at the same time. The production of fibronectin in the rough endoplasmic reticulum of mesenchymal cells and the involvement of this glycoprotein in a mechanical linkage between the vasoformative mesenchymal cells and endothelial ones of the SCs are indicated by immunocytochemistry. The plasma membrane of the marginal cells (MCs) begins to show immunoreactions of Na+.K+ ATPase at postnatal day 5 and is conjugated to each other by tight junctions at postnatal day 14. The apical tubules of the differentiating MCs do not seem to be involved in the endocytotic activity but are involved in the plasma membrane supply for the rapid differentiation.

Animals↗

The antisense homology box: a new motif within proteins that encodes biologically active peptides.

Amphiphilic peptides approximately fifteen amino acids in length and their corresponding antisense peptides exist within protein molecules. These regions (termed antisense homology boxes) are separated by approximately fifty amino acids. Because many sense-antisense peptide pairs have been reported to recognize and bind to each other, antisense homology boxes may be involved in folding, chaperoning and oligomer formation of proteins. The antisense homology box-derived peptide CALSVDRYRAVASW, a fragment of human endothelin A receptor, proved to be a specific inhibitor of endothelin peptide (ET-1) in a smooth muscle relaxation assay. The peptide was able to block endotoxin-induced shock in rats as well. Our finding of endothelin receptor inhibitor among antisense homology box-derived peptides indicates that searching proteins for this new motif may be useful in finding biologically active peptides.

Amino Acid Sequence↗

Alteration of phospholipase C-delta protein level and specific activity in Alzheimer's disease.

Phosphoinositide-specific phospholipase C (PLC) is a key enzyme in signal transduction. We have previously demonstrated that an antibody to an isozyme of PLC, PLC-delta, produced intense staining of neurofibrillary tangles in the brains of patients with Alzheimer's disease. In the present study, we investigated the protein level and activity of this enzyme in control and Alzheimer brains. Western blot analysis using a specific antibody for PLC-delta showed that the concentration of PLC-delta protein was significantly higher in the cytosolic fraction of Alzheimer disease cortical tissue than in control brains. The activity of PLC-delta, which hydrolyzes phosphatidylinositol, was also investigated, and we found that PLC-delta activity was not significantly different in the Alzheimer and control cytosolic fractions. These results indicate that the specific activity of PLC-delta is decreased in Alzheimer brains and suggest that inactivation of PLC-delta might be related to the pathophysiology of this disease.

Aged↗

Progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy (PEHO syndrome) in two Japanese siblings.

We report on two Japanese siblings (one female and one male) with PEHO syndrome (progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy). They showed profound generalized hypotonia early in infancy and developed infantile spasms with hypsarrhythmia within the first year of life. Abnormal eye movement and visual failure with optic atrophy were also observed early in infancy. Psychomotor development was arrested and serial neuroradiological studies showed slight progressive brain atrophy, dominantly of the brainstem. This is the first case report of PEHO syndrome, other than those dealing with the Finnish population.

Brain↗

The structure and characterization of the surface protein layer of a Comamonas-like organism.

The regular surface layer of a strain of a Comamonas-like organism was examined by electron microscopy. The surface layer protein was easily extracted from the cell surface by a 2.5 M solution of lithium chloride. The protein subunit has a molecular size of 32,000 daltons, but usually forms a large aggregate of more than 1,200,000 daltons. In the extract it formed a regular array of p4 symmetry and was observed to be intimately associated with fragments of lipopolysaccharide. The size of a subunit determined by the negative staining method and the image processing method measured 5.2 x 6.4 nm (width and length), was arranged in a cobblestone-like pattern, and was located in a lattice space measuring 13.0 nm square.

Bacterial Proteins↗

Serum concentration of endogenous G-CSF in women during the menstrual cycle and pregnancy.

Although granulocyte-colony stimulating factor (G-CSF) is commonly used in the field of supportive therapy for cancer treatment, the serum concentration of endogenous G-CSF in healthy women is still obscure due to the low sensitivity (30 pg mL-1) of the usual enzyme immunoassay. With the development of a highly sensitive (1.0 pg mL-1) chemiluminescent immunoassay by Kiriyama et al., we have clarified the changes of serum G-CSF levels in healthy women during the menstrual cycle and pregnancy. The G-CSF concentration showed a peak value of 27.3 +/- 2.5 pg mL-1 (mean +/- SEM) at the ovulatory phase during the menstrual cycle, which is significantly higher than in all other phases (P < 0.0001, unpaired t-test). A significantly higher value compared to the menstrual cycle, except during the ovulatory phase, was also revealed throughout pregnancy (P < 0.0001, unpaired t-test). These results suggest that G-CSF plays an important role in ovulation and the maintenance of pregnancy.

Adult↗