Biomedical subjects

M Kamada

Publications and source records attributed to M Kamada.

At least 91 records · Page 5Linked to original sources

PubMed1998

beta-Microseminoprotein/prostatic secretory protein is a member of immunoglobulin binding factor family.

Human seminal plasma contains a factor that binds human IgG, designated as immunoglobulin binding factor (IgBF). Under reducing condition IgBF interacts with anti-Leu-11b, a murine monoclonal antibody raised against human FcgammaRIII/CD16. IgBF shows no binding activity under non-reducing condition. Three components having IgBF activity were separated by HPLC and their amino acid sequences determined. The main IgBF showed structural identity to beta-microseminoprotein (beta-MSP), prostatic secretory protein of 94 amino acids (PSP94) and beta-inhibin. The slight variation in the reported sequences of these proteins has been attributed to analytical error. In the present study the molecular masses of main IgBF and beta-MSP/PSP94 were found to be identical by mass spectrometry. In addition, a large component of IgBF and a shorter beta-MSP consisting of 93 amino acids were identified. The binding of beta-MSP for human IgG and anti-Leu-11b antibody is demonstrable only under reducing condition, determined by Western blot analysis. The present data clearly show that IgBF is a family composed of at least three isoforms. One of the members is beta-MSP/PSP94. This family should be designated as IgBF.

Amino Acid Sequence↗

PubMed1998

Enzymatic activation of immunoglobulin binding factor in female reproductive tract.

Human seminal plasma and cervical mucus contains an immunoglobulin binding factor (IgBF) which interacts with IgG as monomers under reducing condition. It may play a role in preventing antibody production against allogeneic sperms in the female reproductive tract. However, since IgBF is secreted as a homodimer that does not bind IgG, in vivo activation systems should be investigated. GSH reduces the inactive native dimer to the active monomer. Protein disulfide isomerase (PDI), a molecular chaperone, alters the configuration of dimers to active monomers. 20S proteasomes produced by activated T cells which cleave the dimers in the presence of GSH to active fragments. All these activating systems are widely distributed as cellular enzymes in vivo. Also PDI mRNAs are expressed in uterine cervix, endometrium and fallopian tube. Since these enzymes are produced upon stimulation by the immune system, we hypothesize that immunocompetent cells interact with allogeneic sperms, leading to the local production of these enzymes that will activate IgBF.

Cervix Mucus↗

PubMed1998

Performance of a helical undulator of the UVSOR.

A helical undulator was installed in the 0.75 GeV storage ring of the UVSOR facility of the Institute for Molecular Science. The undulator was designed to produce the fundamental of the circularly polarized undulator radiation in the energy range 2-43 eV, and the higher harmonics with elliptical polarization in the energy range up to 300 eV. Recently, the first spectrum from the undulator was observed. The performance of the undulator and the obtained spectrum are reported.

Journal Article↗

PubMed1998

Application of synchrotron radiation to ultrafast spectroscopy.

A novel application of synchrotron radiation to ultrafast optical spectroscopy is demonstrated. The application is based on the short coherence time of broadband synchrotron radiation and employs a conventional interferometer. From a detailed study of the coherence of synchrotron radiation, it is shown that the coherent interference between two synchrotron radiation beams, split from a single beam, can provide ultimate time resolution down to a few femtoseconds. Experimental results of ultrafast spectroscopy using broadband synchrotron radiation are presented; these include free-induction decay and photon echoes in the visible and ultraviolet regions.

Journal Article↗

PubMed1998

Upgraded IR beamline at UVSOR.

BL6A1, a far-infrared (FIR) beamline at UVSOR, originally built in 1986, has been recently upgraded. The upgrade included the introduction of a second FT-IR spectrometer, making it possible to cover the entire FIR-IR range (3-10000 cm(-1)) in one sequence of measurements, without having to open the sample chamber; the beamline has become a more convenient and powerful experimental station than before. The upgrade is also expected to enable such experiments as IR studies of molecules adsorbed on solid surfaces, and time-resolved IR spectroscopies. This paper describes the characteristics of the upgraded BL6A1.

Journal Article↗

PubMed1998

Construction and performance test of SGM-TRAIN at UVSOR.

A new spherical-grating monochromator with translational and rotational assembly including a normal-incidence mount (SGM-TRAIN) has been constructed at BL5A of the UVSOR facility. The SGM-TRAIN is an advanced version of a constant-length SGM with the following improvements: (i) a wide energy range of 5-250 eV; (ii) a high resolving power; (iii) use of linear and circular polarization; (iv) reduction of second-order light; (v) two computer-controlled driving modes. Part of the performance tests are reported along with a detailed description of the design.

Journal Article↗

PubMed1998

Combined system of synchrotron radiation and laser for solid-state research.

Two combined systems of synchrotron radiation and laser have been constructed for solid-state research. One is a laser-induced fluorescence system to observe synchrotron radiation-induced desorption of alkali atoms from ionic crystals, which consists of a laser diode with a high repetition rate and synchrotron radiation under a single-bunch operation. The other is a system of two-photon spectroscopy, which is based on the combination of synchrotron radiation pulses with a low intensity and high repetition rate and Nd:YAG laser pulses with a high intensity and low repetition rate. The experimental systems and the preliminary results are presented in this report.

Journal Article↗

PubMed1998

Present Status of the UVSOR Facility - 1997.

The UVSOR has been operational for nearly 14 years. In recent years, improvements to accelerators and beamlines have been carried out to obtain better performance and new scientific achievements. For example, a new type of helical undulator and a resonance transverse kicker were installed into the straight sections of the storage ring, and about one-third of the beamlines were upgraded by installing new monochromators and an interferometer. In addition, instruments and equipment were improved for research studies, with many interesting results. The most up-to-date information of the UVSOR facility is presented.

Journal Article↗

PubMed1998

Production of monoclonal antibodies to six isotypes of horse immunoglobulin.

Stable clones of 18 mouse hybridomas that produce monoclonal antibodies (MAbs) to six isotypes of horse immunoglobulin were produced. The number of hybridomas of different specificities are: four to IgGa, four to IgGb, one to IgGc, four to IgG(T), two to IgM, and three to IgA. The immunoglobulin isotypes purified from affinity columns bound with each MAb showed variable mobility in agarose-gel electrophoresis. Migration proceeded from the anode as: IgG(T), IgA, IgM, IgGc, IgGb and IgGa. The purified isotypes also demonstrated a single precipitin line when in immunoelectrophoresis against isotype-specific or polyclonal antisera, raised against the purified isotype or whole equine serum, respectively.

Animals↗

PubMed1998

Detection of virulent Rhodococcus equi in tracheal aspirate samples by polymerase chain reaction for rapid diagnosis of R. equi pneumonia in foals.

Polymerase chain reaction (PCR)-based assays were developed to detect virulent Rhodococcus equi in transtracheal aspirate samples from sick foals showing respiratory signs. An oligonucleotide primer pair from the sequence of the virulence-associated 15- to 17-kDa antigen gene of the virulence plasmid in virulent R. equi was used to amplify a 564 bp region by PCR, and the result was confirmed by Southern blot hybridization. No positive reaction was seen in DNA from 13 different microorganisms typically found in the respiratory tract. In tracheal aspirates seeded with virulent R. equi, a visible band could detect 10 to 10(2) bacteria per PCR assay (10(3) to 10(4)/ml of the aspirate). Virulent R. equi was demonstrated in 31 of 42 transtracheal aspirates by culture and colony blot analysis, whereas a positive PCR result was observed in only 12 of the 31 culture positive samples. To prevent false-negative results, two methods were developed: a nested PCR and a PCR in combination with enrichment cultures of aspirates in the selective medium to increase the number of bacteria to 10(4)/ml or more. All of the PCR-negative and culture-positive samples were positive by the two methods. These results indicated that PCR-based assays provide a specific and sensitive means to detect virulent R. equi in tracheal aspirates of foals, and they are more rapid than the routine culture procedures for the diagnosis of R. equi pneumonia in foals.

Actinomycetales Infections↗

PubMed1998

Effect of antisense oligonucleotides against cholesteryl ester transfer protein on the development of atherosclerosis in cholesterol-fed rabbits.

Cholesteryl ester transfer protein (CETP) is the enzyme that facilitates the transfer of cholesteryl ester from high density lipoprotein (HDL) to apolipoprotein B (apoB)-containing lipoproteins. However, the exact role of CETP in the development of atherosclerosis has not been determined. In the present study, we examined the effect of the suppression of increased plasma CETP by intravenous injection with antisense oligodeoxynucleotides (ODNs) against CETP targeted to the liver on the development of atherosclerosis in rabbits fed a cholesterol diet. The ODNs against rabbit CETP were coupled to asialoglycoprotein (ASOR) carrier molecules, which serve as an important method to regulate liver gene expression. Twenty-two male Japanese White rabbits were used in the experiment. Eighteen animals were fed a standard rabbit chow supplemented with 0.3% cholesterol throughout the experiment for 16 weeks. At 8 weeks, they were divided into three groups (six animals in each group), among which the plasma total and HDL cholesterol concentrations did not significantly change. The control group received nothing, the sense group were injected with the sense ODNs complex, and the antisense group were injected with the antisense ODNs complex, respectively, for subsequent 8 weeks. ASOR. poly(L-lysine) ODNs complex were injected via the ear veins twice a week. Four animals were fed a standard rabbit diet for 16 weeks. The total cholesterol concentrations and the CETP mass in the animals injected with antisense ODNs were all significantly decreased in 12 and 16 weeks compared with those injected with sense ODNs and the control animals. The HDL cholesterol concentrations measured by the precipitation assay did not significantly change among the groups fed a cholesterol diet, and triglyceride concentrations did not significantly change in the four groups. However, at the end of the study, when the HDL cholesterol concentrations were measured after the isolation by ultracentrifugation and a column chromotography, they were significantly higher in the animals injected with antisense ODNs than in the animals injected with sense ODNs and in the control animals. A reduction of CETP mRNA and an increase of LDL receptor mRNA in the liver were observed in the animals injected with antisense ODNs compared with those injected with sense ODNs and the control animals. Aortic cholesterol contents and the aortic percentage lesion to total surface area were significantly lower in the animals injected with antisense ODNs than in the animals injected with sense ODNs and in the control animals. These findings showed for the first time that suppression of increased plasma CETP by the injection with antisense ODNs against CETP coupled to ASOR carrier molecules targeted to the liver could thus inhibit the atherosclerosis possibly by decreasing the plasma LDL + very low density lipoprotein (VLDL) cholesterol in cholesterol-fed rabbits.

Animals↗

PubMed1998

Integrin beta2 (CD18)-mediated cell proliferation of HEL cells on a hematopoietic-supportive bone marrow stromal cell line, HESS-5 cells.

Cellular interactions between hematopoietic cells and stromal cells play important roles in the proliferation and differentiation of hematopoietic cells. The proliferation of a human erythroleukemia cell line, HEL cells, which can differentiate into macrophage- and megakaryocyte-like cells, and erythroid precursors was dramatically induced on coculture with a hematopoietic-supportive stromal cell line, HESS-5 cells, which can support long-term hematopoiesis in vitro without fetal bovine serum. HEL cells proliferated when they were cocultured with but not without direct cell contact. Because the coculture supernatants with direct cell contact and cytokines such as interleukins and growth factors did not exhibit growth-stimulating activity toward HEL cells, it was suggested that some molecule that has growth-stimulating activity exists on the surface of the cells. Extracellular matrix components such as fibronectin, laminin, vitronectin, and collagen did not affect the proliferation of HEL cells. An anti-CD18 monoclonal antibody, which recognizes the common beta chain of the beta2 integrin subfamily, induced dramatic proliferation of HEL cells. Moreover, the proliferation of HEL cells was inhibited by an antisense oligonucleotide of CD18 mRNA. As judged from these observations, the proliferation of HEL cells was mediated by CD18 molecules expressed on HEL cells. On the contrary, the common counter-receptor of the beta2 integrin subfamily, intercellular adhesion molecule-1, which is expressed on CHO-K1 cells, did not stimulate the growth of HEL cells. It is known that other counter molecules of the beta2 integrin subfamily, such as complement C3bi and fibrinogen, are not produced by stromal cells. These findings suggest that the proliferation of HEL cells may be induced through an interaction between a novel molecule of the beta2 integrin subfamily on HEL cells and the counter-receptor on HESS-5 cells. The beta2 integrin subfamily may regulate the growth of hematopoietic cells in hematopoiesis in vivo and/or cause the abnormal growth of leukemia cells.

Animals↗

PubMed1998

Hemolysis complicating coil occlusion of patent ductus arteriosus.

We report on 5 patients who developed hemolysis (the Hemolysis group) following coil occlusion for PDA, and compare their data to 66 cases which were not complicated by hemolysis despite residual leak (the No Hemolysis group). A significant leak with a heart murmur was more frequent in the Hemolysis group than in the No Hemolysis group. The ratio of the sum of the loop diameter of coils to the minimal diameter of the ductus (C/D) in those who developed persistent hemolysis that needed a second intervention (2.2+/-0.4) was significantly smaller than in the No Hemolysis group (3.1+/-1.1). Persistent hemolysis can occur if a significant residual shunt remains after implantation of coils with small C/D. As this complication may be avoided by complete closure or, if not complete, a minimal leak, we should be careful to make residual leaks as small as possible by the use of multiple coils.

Anemia, Hemolytic↗

PubMed1998

Overexpression of CD44 variants 6 and 7 in human endometrial cancer.

OBJECTIVES: The expression of CD44 V6, V7, and V10 in normal endometrium and endometrial cancer was compared. METHODS: Using reverse transcription polymerase chain reaction (RT-PCR) blot analysis, the expression of mRNA containing CD44 V6, V7, and V10 was determined in 19 normal endometrium and 27 endometrial cancer samples. Immunohistochemical staining of CD44 V6 and V7 was performed in the same samples. RESULTS: In RT-PCR analysis, the CD44 variant forms containing V6 and V7 exons were expressed in 96 and 93% of endometrial cancer tissues, respectively. These proportions were significantly higher than those in normal endometrium (V6, 63%; V7, 58%) (P < 0.01). CD44 V10 was expressed in 96% of endometrial cancers and 89% of normal endometrial samples. In immunohistochemical staining, CD44 V6 and V7 were detected in 48 and 61% of endometrial cancers and in 26 and 42% of normal endometrial samples, respectively. Neither of these differences was significant. No correlation was found between the expression of CD44 variants and any clinicopathological features. CONCLUSION: CD44 V6 and V7 were expressed in a significantly larger proportion of endometrial cancers than normal endometrial samples. However, they were also expressed in a considerable proportion of normal endometria. These findings suggest that CD44 V6 and V7 play roles in normal endometrial function and overexpression of CD44 V6 and V7 is not related to the metastatic potential of endometrial cancer.

Adult↗

PubMed1998

[Successful repair of critical aortic stenosis with coarctation on the first day of life].

Successful open aortic valvotomy and end-to-end anastomosis were performed to the patient with critical aortic stenosis and CoA on the first day of life. A fetus was diagnosed as aortic stenosis and coarctation by fetal echocardiography at 29 weeks of gestation. The mother was transferred to our hospital at the onset of labor and delivered vaginally at 40 weeks of gestation. Soon after the birth, the newborn, birth weight 2630 gram, female, underwent echocardiography by pediatric cardiologists which demonstrated the aortic orifice of 5.1 mm in diameter and thickened cusps with poor mobility. Transaortic pressure gradient measured by Doppler echocardiography was 111 mmHg and the left ventricular wall motion was hyperdynamic without any signs of endocardial fibroelastosis. Prostaglandin E1 administration was started to maintain systemic circulation and the hemodynamic status has been stable before surgery. On her first day of life, the operation was performed using cardiopulmonary bypass with moderate hypothermia. Isolated cerebral and myocardial perfusion technique was applied during the repair of coarctation of the aorta. The open aortic valvotomy with resection of myoxomatous nodules on leaflet edges effectively released pressure gradient across the aortic valve without regurgitation. Post-operative course was uneventful and she discharged at 28th day after surgery. We conclude early diagnosis including fetal echocardiography and early repair would lead the better surgical outcome to the neonates with critical aortic stenosis.

Alprostadil↗

PubMed1998

Phylogenetic analyses of the matrix and non-structural genes of equine influenza viruses.

Matrix (M) and nonstructural (NS) genes of thirteen equine H3N8 and H7N7 influenza viruses were sequenced and analyzed from an evolutionary point of view. The M and NS genes of H3N8 viruses isolated between 1989 and 1993 evolved into two minor branch clusters, including isolates from Europe and the American continent, respectively. It was noteworthy to reveal that the nucleotide sequences of the M and NS genes of an earlier American strain showed highest homology to those of recent European viruses. "Frozen evolution" was observed in the M and NS genes of A/eq/LaPlata/1/88. It was also evident that the NS gene of an H7N7 virus from 1977 was very similar to that of a 1979-H3N8 virus, while the M gene was closest phylogenetically to that of the earliest H7N7 virus isolated in 1956. Furthermore, the M2 protein of A/eq/Newmarket/1/77 virus contained a carboxyl terminal deletion of three amino acids. The evolutionary rates of the M and NS genes of H3N8 equine influenza viruses were estimated to be 5.4 x 10(-4) and 5.1 x 10(-4) substitutions per site per year, respectively, which were slower than those of human viruses.

Amino Acid Sequence↗

PubMed1998

Autoantibody against testosterone in a woman with hypergonadotropic hypogonadism.

We demonstrate that antitestosterone autoantibody is produced in a 24-yr-old woman with hypergonadotropic hypogonadism. The serum testosterone level measured by RIA was extremely elevated (5.80 ng/mL); after elution, serum testosterone had returned to a normal female value (0.21 ng/mL). The clinical features were suggestive of no androgen activity. Primary follicles were present in the patent's ovary. After gonadotropin treatment, conception was achieved, and a normal female infant was delivered. A gel filtration study showed that the testosterone-binding activity was eluted at the position of 15,000-kDa Ig. Scatchard analysis revealed a low affinity antibody; the association constant was 0.034 x 10(3) mol-1, and the maximal binding capacity was 162 mumol/mL. An immunoprecipitation study the chain-specific antibodies showed that the antitestosterone autoantibody belonged to kappa-type IgG. This subject is the first reported case with an endocrine disorder who possessed autoantibodies against testosterone.

Adult↗

PubMed1998

Identification of B cell epitopes of a 30 kDa Babesia equi merozoite surface protein.

A 30 kDa immunodominant surface antigen (p30) of Babesia equi has been used as a diagnostic antigen. The B cell epitopes on this molecule recognized by horse sera and monoclonal antibody (MAb) against p30, 36/133.97, were determined. A synthetic peptide of p30 with amino acid sequence of 123FYQEVLFKGFEAV135 exhibited strong positive reaction with the infected horse sera. In contrast, MAb 36/133.97 recognized different region of p30, as peptide synthesized with amino acid sequence of 27ASGAVVDFQLESI39 reacted strongly. In competitive inhibition ELISA, the binding of MAb 36/133.97 to recombinant p30 was inhibited by horse antibodies, although they did not recognize same or an overlapping epitope. The data on B cell epitopes in this study may be important in improving serodiagnostic methods of B. equi infection.

Amino Acid Sequence↗