Search PubMed⌕ Search

Biomedical subjects

R Fujii

Publications and source records attributed to R Fujii.

At least 55 records · Page 3Linked to original sources
PubMed1999

Neural features of recovery from CNS injury revealed by PET in human brain.

Dysfunction of the brain occurring after local brain injury often improves clinically; however, the reason for this improvement has not been scientifically clarified. We used a new technique for imaging phosphoinositide turnover, carbon-11-labeled diacylglycerol-positron emission tomography, to observe the process of recovery from injury in human brain. Patients with local brain injury exhibited radioactive spots located in the association areas distant from the lesion, while normal controls did not exhibit such spots. These findings indicated one of possible features of the neural recovery from the central nervous system injury, which appears to play a role in modulation of synaptic transmission in the intact brain. Conventionally, attention has been directed primarily to areas surrounding brain injury, such as the penumbra; however, the present study suggests that initiation of reorganization of neural connections occurs in remote cortex.

Adult↗
PubMed1999

Factors associated with calcification of the abdominal aorta in hemodialysis patients.

BACKGROUND: Cardiovascular and cerebrovascular injury caused by arteriosclerosis has been the major cause of the death in hemodialysis (HD) patients. We quantitatively analyzed and evaluated the severity of abdominal aortic calcification in HD patients in comparison to risk factors for arteriosclerosis. METHODS: One hundred thirty-seven HD patients were examined. Using image analysis software, areas of the calcified abdominal aorta were quantitatively analyzed on plain computerized tomography images. Other factors such as blood pressure (BP), lipid levels, and calcium (Ca) x phosphorus (Pi) value were also analyzed. RESULTS: Patients with a higher one-year average of systolic BP showed a higher severity of abdominal aortic calcification. That is, the severity of abdominal aortic calcification in patients with a one-year systolic BP average above 160 mm Hg was 31.5 +/- 13.6%, and this severity was significantly higher than that in patients with a one-year systolic BP average of less than 120 mm Hg (8.0 +/- 7.7%, P < 0.01). The severity of abdominal aortic calcification in patients demonstrating risk values of ectopic calcification, that is serum Ca x Pi > or = 60 (mg/dl), on more than 4 of 24 measurements within one year (25.8 +/- 13.6%) was significantly higher than the severity of aortic calcification in patients demonstrating this value less than four times in one year (P < 0.05). There was no correlation between levels of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, lipoprotein(a), and severity of abdominal aortic calcification. CONCLUSIONS: Systolic BP levels and the product of serum Ca and Pi were related to the severity of abdominal aortic calcification in HD patients. These observations suggested that BP control, as well as control of serum Ca and Pi levels, was important in preventing the progression of abdominal aortic arteriosclerosis.

Age Factors↗
PubMed1999

Distribution of mefE and ermB genes in macrolide-resistant strains of Streptococcus pneumoniae and their variable susceptibility to various antibiotics.

From February to October 1995, 62 erythromycin-resistant strains of Streptococcus pneumoniae isolated at Yamanashi Red Cross Hospital were tested to determine their susceptibility to various macrolides, subjected to resistance induction tests by the disc diffusion method and analysed for genes encoding resistance to macrolides (ermB and mefE). On the basis of resistance induction testing, the isolates were classified as having either inducible (59.7%) or non-inducible (40.3%) macrolide resistance. The ermB gene was always detected in resistance-inducible type isolates, either alone or in combination with mefE. The mefE gene alone was found only in non-inducible type isolates. Isolates with non-inducible resistance (those with only the mefE gene) had an intermediate level of resistance to 14-membered macrolides, and were susceptible to rokitamycin, a 16-membered macrolide. According to NCCLS guidelines, 9.6% of S. pneumoniae strains were judged to be susceptible to penicillin, 62.9% of reduced susceptibility and 27.4% penicillin resistant. No correlation was detected between the presence of particular macrolide-resistance genes (ermB, ermB + mefE, or mefE) and resistance to penicillin G.

Anti-Bacterial Agents↗
PubMed1999

[Three children with systemic cat scratch disease].

Three girls with systemic cat scratch disease, aged 10, 13 and 9 years, were reported. They presented a prolonged fever and back pain in the early stage of the disease, and had no regional lymphadenopathy. Two of them had hepatosplenic granulomas, one with multiple 5 mm hypoechoic lesions in the liver and spleen, and the other with a single 2.5 cm hypodense lesion in the left hepatic lobe. The latter patient underwent a partial left hepatic lobectomy. All patients had elevated titers of antibodies to Bartonella henselae. Polymerase chain reaction detected B. henselae DNA in tissue specimens of the patient who underwent a hepatic lobectomy. Cat scratch disease should be recognized as a cause of fever of unknown origin because the prevalence of B henselae infection might be higher in Japan.

Adolescent↗
PubMed1999

[Influence of dexamethasone on the clinical course of bacterial meningitis in children. Especially on secondary fever. Experiences in 27 institutions].

Of pediatric patients with purulent meningitis seen at the institutions listed in the title page of this paper between 1986 and 1994, 93 patients treated with antibiotics and dexamethasone (DXM) were compared with 91 patients treated with antibiotics alone. The patients receiving antibiotics with dexamethasone achieved overall improvement in inflammatory symptoms and signs and cerebrospinal fluid findings and became afebrile significantly earlier than those receiving antibiotics alone. However, some of the patients became febrile again. The secondary fever rate for the DXM group was much higher than that for the antibiotic alone group (p < 0.0001). In most of the rebounded cases, the body temperature rose above 38 degrees C and remained elevated for 2-4 days. Cerebrospinal fluid (CSF) was cultured daily in 54 and 32 patients receiving antibiotics with and without DXM, respectively. Although this study was not a controlled study in a strict sense, these patients compared. In both groups, the CSF became mostly culture-negative within 48 hours. In a few patients receiving DXM, however, it became culture-negative after 72 hours or longer. DXM caused an adverse effect in a patient with meningitis caused by Streptococcus pneumoniae. The adverse effect was mild gastrointestinal bleeding, which recovered spontaneously. From the findings described above, the use of DXM combined with antibiotic therapy was considered to accelerate the relief from fever and improvement of inflammatory symptoms and signs and CSF findings. The body temperature rose again in more than half of the patients receiving DXM, but fell to normal spontaneously without treatment. The elevation doubtlessly could not be distinguished from recurrence of the meningitis itself or complications. It seems to be likely that no treatment but careful observation is required even if the fever recurs as far as the CSF findings showed favorable progress with excelluent general conditions. When DXM is given, it is essential that CSF tests and culture are repeated during the early stages and the progress is monitored carefully.

Anti-Bacterial Agents↗
PubMed1999

[Pharmacokinetic analysis of cefozopran in neonatal infections--population pharmacokinetics using nonmem].

This report describes the results on pharmacokinetics, efficacy and safety of cefozopran (CZOP) in neonatal patients. Enrolled patients were 136 in total whose informed consents to enter this study had been given by their parents. Among them, blood samples were collected from 42 neonates to analyze concentrations of CZOP by population pharmacokinetics (PPK) methods. Based on this analysis, the average pharmacokinetic parameters of CZOP and the variabilities of them in different morbid pharmacological backgrounds and in different subjects were evaluated. This PPK analysis showed that clearance (CL) and distribution volume (Vd) of CZOP could be estimated by the following equations; CL = 0.0452 x WT1.75 (in the case of the postnatal age of over than 1 day) CL = 0.623 x 0.0452 WT1.75 (in the case of the postnatal age of 1 day or less) Vd = 0.455 x WT where WT indicates body weight in kg. The coefficients of variation among individual subjects on CL and Vd were found to be 20.7% and 20.0%, respectively. From this PPK analysis it was indicated that the elimination of CZOP is dependent on the postnatal age and is approximately 38% lower in the younger group than in the older group. Therefore, it could be concluded that, though the cases of evaluation were small in number, adjustment of dosing of CZOP is necessary, particularly in prolongation of intervals of administration, in cases of postnatal age of 1 day or less.

Cephalosporins↗
PubMed1999

MPC-1-CD49e- immature myeloma cells include CD45+ subpopulations that can proliferate in response to IL-6 in human myelomas.

Using three-colour phenotypic analysis, we detected five subpopulations of myeloma cells (CD38++) in the bone marrow mononuclear cells of human myeloma patients: MPC-1-CD45-CD49e-, MPC-1-CD45+CD49e-, MPC-1+CD45-CD49e-, MPC-1+CD45+CD49e- and MPC-1+CD45+CD49e+. Most of the myeloma cells did not express CD45 but a few MPC-1- immature myeloma cells and some MPC-1+ myeloma cells expressed CD45 and CD45RO but not CD45RA, whereas all of normal early plasma cells in the peripheral blood, lymph node plasma cells and bone marrow plasma cells expressed CD45 and CD45RA, CD45RB but not CD45RO. In order to clarify the biological character of these myeloma subpopulations, we examined the expression of Ki-67 antigen. Proliferating myeloma cells (Ki-67+) were found in the MPC-1- fractions and the MPC-1-CD45+ fractions rather than MPC-1-CD45- fractions. Next, in order to further clarify the biological difference of two immature subpopulations (MPC-1-CD45-CD49e- and MPC-1- CD45+CD49e-), determined cell viability and phenotypic change after culturing with interleukin 6 (IL-6) in vitro. In the presence of IL-6, MPC-1-CD45+ cells kept their viability more than MPC-1-CD45- cells and some MPC-1-CD45- cells could be converted to MPC-1-CD45+ cells. In conclusion, these data suggest that human myeloma cells are phenotypically subdivided into five subpopulations, and among these subpopulations MPC-1-CD45+CD49e- but not MPC-1-CD45-CD49e- immature cells contain proliferating cells in response to IL-6, and IL-6 can also induce expression of CD45 on MPC-1-CD45- subpopulation of immature myeloma cells.

Apoptosis↗
PubMed1999

[Plasma nicotinic acid levels in hemodialysis patients after the administration of niceritrol].

Lp(a) has recently begun to attract attention as a risk factor of atherosclerotic disease, especially of ischemic heart disease. The Lp(a) concentration in the serum was shown to be important for chronic hemodialysis patients who have high mortality due to cardiovascular disease. Nicotinic acid derivatives, which are recognized for their capacity to lower the serum Lp(a) concentration, are effective against a high Lp(a) concentration in hemodialysis patients. In this study, niceritrol which is a nicotinic acid derivative was tested on hemodialysis patients and healthy controls by investigating the serum nicotinic acid level. Serum nicotinic acid concentration was also measured by the severity of renal dysfunction of patients untreated by niceritrol. The blood nicotinic acid concentration in healthy controls (n = 4) was changed after 2 hrs by the administration of niceritrol from 9.8 +/- 1.4 ng/ml to 192.7 +/- 23.1 ng/ml then slowly decreased. Chronic hemodialysis patients who take niceritrol every day showed the highest nicotinic acid serum concentration (500-1,000 ng/ml) on the day without hemodialysis and the serum level decreased with dialysis for 4 hrs to 25-80%. There was no significant difference in the nicotinic acid level in the serum between healthy controls (n = 10), chronic glomerulonephritis patients (n = 7), chronic renal failure patients (n = 8) and chronic hemodialysis patients (n = 17). Lp(a) concentration in the serum, however, was increased with greater severity of renal dysfunction, The side effect was not observed in any cases administered niceritrol. These data suggest nicotinate derivatives are effective for hemodialysis patients. High nicotinic acid level in the serum after treatment with niceritrol was lowered by dialysis. It is plausible that the nicotinate level in patients without niceritrol treatment did not influence the Lp(a) concentration, because there was no increase in the nicotinate level of the serum even if the patients had renal dysfunction.

Arteriosclerosis↗
PubMed1999

Evaluation of phosphoinositide turnover on ischemic human brain with 1-[1-11C]-butyryl-2-palmitoyl-rac-glycerol using PET.

UNLABELLED: It is important to evaluate cerebral function from neural signal transduction in ischemic brain in judging morbid state and prognosis. We synthesized 1-[1-(11)C]-butyryl-2-palmitoyl-rac-glycerol (DAG) for the purpose of imaging the second messenger on PET and applied it to clinical cases of cerebral infarction. METHODS: Five patients, who had ischemic stroke, were examined with PET. [15O]-CO2 and [15O]-O2 inhalation methods were applied to cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2). For the measurement of phosphoinositide turnover after intravenous injection of DAG, dynamic PET data were collected continuously for 46 min. Arterial blood samples were taken to evaluate changes in the serum concentration of DAG. To quantify the metabolic activity of inositol phospholipid, the incorporation constant k*(DAG) was calculated on the basis of the kinetics of DAG. RESULTS: The plasma concentration of DAG increased rapidly and peaked 30 s after injection of DAG solution. In the normal cortex, DAG concentration increased gradually and reached a plateau between 15 and 20 min after injection. In the ischemic core (infarction), DAG concentration increased slowly, and its peak concentration was lower than that in normal tissue. In comparison with blood flow and metabolic parameters, k*(DAG) showed the best correlation with CMRO2, suggesting a reflection of neuronal activity. Locally, CBF and CMRO2 gradually decreased from the normal area toward the ischemic center (infarction), whereas k*(DAG) and OEF significantly decreased only in the ischemic center. CONCLUSION: The k*(DAG) of ischemic brain, including that caused by infarction, significantly correlated with CMRO2, suggesting that metabolic activity of inositol phospholipid reflects neural viability. Maintained metabolic activity of inositol phospholipid in the region around the ischemic core indicated preservation of the signal transduction system through the metabotropic receptor.

Aged↗
PubMed1998

Generation of triplet and cation-radical bacteriochlorophyll a in carotenoidless LH1 and LH2 antenna complexes from Rhodobacter sphaeroides.

The LH1 antenna complex and a native form of the LH2 complex were isolated from the carotenoidless R26 and R26.1 mutants of Rhodobacter sphaeroides by the use of a new detergent, sucrose monocholate. One-color, pump-and-probe transient Raman spectroscopy of these complexes using 351 nm, approximately 50 ps pulses showed the generation of the triplet state of bacteriochlorophyll a (BChl a), whereas measurements using 355 nm, approximately 12 ns pulses showed the generation of BChl a cation radical. Subpicosecond to nanosecond time-resolved absorption spectroscopy using 388 nm, 200 fs pulses for excitation showed rapid (<1 ps) generation of the triplet state and fast decay (<10 ps) of the singlet state of BChl a. Microsecond absorption spectroscopy confirmed the generation of BChl a cation radical. EPR spectroscopy using 532 nm, approximately 5 ns pulses for excitation established the generation of BChl a cation radical. The EPR line width suggested that the unpaired electron is shared by two BChl a molecules. In LH1, the yield of BChl a cation radical per complex was estimated to be about 80% of that in the reaction center, and in LH2 about 50%. Thus, rapid generation of the triplet state, and its subsequent transformation into the cation-radical state of BChl a have been shown to be intrinsic properties of B870 and B850 BChl a assembly in the carotenoidless LH1 and LH2 antenna complexes. In the case of the carotenoid-containing LH2 complex, the triplet states of BChl a and carotenoid (spheroidene) were generated immediately after excitation, but the triplet-state BChl a was quenched efficiently by the carotenoid so that no BChl a cation radical was generated. Thus, the photoprotective function of the carotenoid in this antenna complex is shown.

Bacterial Proteins↗
PubMed1998

Induction of CD45 expression and proliferation in U-266 myeloma cell line by interleukin-6.

Recently, there has been an increasing interest in the expression pattern and biological significance of the CD45 molecule in myeloma cells. In this study, we have further defined the phenotypic pattern of CD45 expression on myeloma cells. Using a panel of myeloma cell lines, we showed that CD45 showed a remarkably heterogeneous pattern of expression. Whereas some cell lines were CD45(+) and others were CD45(-), the U-266 cell line, although predominantly CD45(-), still had a considerable subpopulation of CD45(+) cells. Among the myeloma cell lines examined, there was a direct correlation between interleukin-6 (IL-6) dependency and CD45 positivity. Moreover, we showed that IL-6 stimulation led to the induction of expression of CD45 and cellular proliferation. Using independent experimental approaches, we could show that the IL-6-induced effects were closely linked to CD45 expression. First, sorting out CD45(+) and CD45(-) subsets of U-266 cell line followed by IL-6 stimulation, only the CD45(+) cells showed a proliferative advantage after IL-6 stimulation. Second, IL-6 stimulation of sorted CD45(-) cells was gradually followed by phenotypic conversion to CD45(+) cells that started after 2 days as judged by the detection of CD45 mRNA by reverse transcription polymerase chain reaction (RT-PCR) and immunophenotypic analysis by flow cytometry. Withdrawal of IL-6 from the medium led to gradual loss of CD45 expression in CD45(+) flow-sorted U-266 cells. Third, the use of vanadate, a potent inhibitor of protein tyrosine phosphatase (PTP), abrogated the IL-6-induced proliferation in the CD45(+) myeloma cells. On the other hand, cellular proliferation induced by IL-6 was not affected by the serine-threonine phosphatase inhibitor okadaic acid. Our data show that the expression pattern of CD45 in myeloma cell lines is heterogeneous and show for the first time that CD45 expression can be induced by IL-6 stimulation. Finally, these data shed some light on the biological role of CD45 in myeloma by determining the proliferative population among myeloma cells.

Antigens, Neoplasm↗
PubMed1998

Isolation and characterization of a novel endogenous peptide ligand for the human APJ receptor.

In the search for an endogenous ligand of the orphan G protein-coupled receptor APJ, the presence of the ligand in various tissue extracts was examined by measuring the increase in extracellular acidification rate of the cells expressing the APJ receptor as a specific signal induced by the interaction of the receptor and ligand. By monitoring this activity, we isolated an APJ receptor ligand, designated apelin, from bovine stomach extracts. The structures of bovine and human apelin preproproteins were deduced from the sequences of the corresponding cDNAs. The preproproteins consisted of 77 amino acid residues, and the apelin sequence was encoded in the C-terminal regions. Synthetic peptides derived from the C-terminal amino acid sequence of bovine preproapelin were capable of specifically promoting the acidification rate in the cells expressing the APJ receptor in a range from 10(-7) to 10(-10) M, indicating that apelin is an endogenous ligand for the APJ receptor.

Amino Acid Sequence↗
PubMed1998

Potentiation of phosphoinositide-derived signals during LTP in intact rat brain.

In order to examine the relationship between long-term potentiation (LTP) and phosphoinositide (PI) turnover, we evaluated these throughout anesthetized rat brain using carbon-11-labeled diacylglycerol (11C-DAG). High-frequency tetanic stimulation (400 pulses at 400 Hz) to the perforant pathway induced LTP in rat dentate gyrus. In autoradiograms of rat brains, LTP was associated with the occurrence of multiple highly radioactive spots in many regions distant from the stimulated site. Following i.v. administration of an NMDA receptor antagonist prior to stimulation, however, no high-density spots were found. These findings directly demonstrate that potentiation of phosphoinositide-derived signaling was induced during LTP, and the finding of multiple location suggests the occurrence of polysynaptic neurotransmission through neural networks pertaining to learning and memory.

Animals↗
PubMed1998

A prolactin-releasing peptide in the brain.

Hypothalamic peptide hormones regulate the secretion of most of the anterior pituitary hormones, that is, growth hormone, follicle-stimulating hormone, luteinizing hormone, thyroid-stimulating hormone and adrenocorticotropin. These peptides do not regulate the secretion of prolactin, at least in a specific manner, however. The peptides act through specific receptors, which are referred to as seven-transmembrane-domain receptors or G-protein-coupled receptors. Although prolactin is important in pregnancy and lactation in mammals, and is involved in the development of the mammary glands and the promotion of milk synthesis, a specific prolactin-releasing hormone has remained unknown. Here we identify a potent candidate for such a hormone. We first proposed that there may still be unknown peptide hormone factors that control pituitary function through seven-transmembrane-domain receptors. We isolated the complementary DNA encoding an 'orphan' receptor (that is, one for which the ligand is unknown). This receptor, hGR3, is specifically expressed in the human pituitary. We then searched for the hGR3 ligand in the hypothalamus and identified a new peptide, which shares no sequence similarity with known peptides and proteins, as an endogenous ligand. We show that this ligand is a potent prolactin-releasing factor for rat anterior pituitary cells; we have therefore named this peptide prolactin-releasing peptide.

Amino Acid Sequence↗
PubMed1998

Toward the antibody-catalyzed chemiluminescence. Design and synthesis of hapten.

Hapten 4 was synthesized to generate catalytic antibodies triggering chemiluminescence by catalyzing the decomposition of the 1,2-dioxetane 3. The hapten 4 was so designed as to elicit a negatively charged functional group in the antibody combining site to catalyze the beta-elimination of the protecting group in 3 as well as to lock the protecting group into an energetically favorable anti-periplanar conformation.

Antibodies, Catalytic↗
PubMed1998

[Determination of anti-Bartonella henselae antibody by indirect fluorescence antibody test--comparison of two types of antigen: non-cocultivated B. henselae and cocultivated B. henselae with Vero cells].

Serum anti-Bartonella henselae IgG and IgM antibody titers for the diagnosis of cat scratch disease (CSD) were determined by indirect fluorescence antibody (IFA) tests. B. henselae as antigen were harvested either by cocultivating with Vero cells (cocultivated B. henselae) or by cultivating without them (non-cocultivated B. henselae). Based on the results on 110 healthy adults, cut off values were set at 1:32 for IgG, and < 1:20 for IgM antibodies. According to these criteria, IgG antibody was positive in 2.7% of the 110 adults, while nobody was positive for IgM antibody. The titers did not change depending on the types of antigen used. On the other hand, IgG antibody titers against cocultivated B. henselae tended to be higher than those against non-cocultivated B. henselae in 33 CSD suspected patients; 75.8% of the patients were anti-B. henselae IgG positive when tested with cocultivated B. henselae as antigen, while only 48.5% of the same patients gave positive results with non-cocultivated B. henselae. Anti-B. henselae IgM antibody was positive in 24.2% of the 33 CSD suspected patients against both types antigen. Vero cells themselves seemed to nonspecifically bind some IgM (but not IgG). We recommended cocultivated B. henselae as antigen for IgG IFA, and non-cocultivated B. henselae for IgM IFA in the serological tests of CSD.

Adult↗