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Biomedical subjects

M Kamada

Publications and source records attributed to M Kamada.

At least 73 records · Page 4Linked to original sources
PubMed2000

In vitro detection of equine arteritis virus from seminal plasma for identification of carrier stallions.

Equine arteritis virus (EAV) was readily isolated in RK-13 cell monolayers by plaque assay from seminal plasma of experimental carrier stallions when they contained high titers of virus regardless of the presence of non-viral cytotoxicity in the seminal plasma. The cytotoxicity interfered with virus isolation from seminal plasma which contained virus at titers less than 10 PFU/ml. However, it was possible to detect the virus in seminal plasma pretreated with PEG (#6000). EAV was consistently identified by RT-PCR from crude seminal plasma which contained virus at titers of more than 10(2.7) PFU/ml. In vitro detection of EAV by virus isolation supplemented with RT-PCR using seminal plasma was proved to be an effective alternative to the standard test mating as a diagnostic method for carrier stallions.

Animals↗
PubMed2000

Evidence that Toki-shakuyaku-san and its ingredients enhance the secretion of a cytokine-induced neutrophil chemoattractant (CINC/gro) in the ovulatory process.

We investigated the effects of Toki-shakuyaku-san and its crude ingredients in relation to the secretion of a cytokine-induced neutrophil chemoattractant, CINC/gro, interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF alpha) in the ovulatory process. Toki-shakuyaku-san significantly (p < 0.01) stimulated the secretion of 17 beta-estradiol but did not stimulate the secretion of progesterone in cultured whole ovarian dispersates. Toki-shakuyaku-san enhanced the secretion of CINC/gro in a dose-dependent manner and the production of CINC/gro at concentrations of 10 and 100 micrograms/ml of Toki-shakuyaku-san increased significantly (p < 0.01). Toki-shakuyaku-san also enhanced secretions of both IL-1 beta and TNF alpha, which are known to stimulate the secretion of CINC/gro in the ovulatory process. The production of TNF alpha increased significantly (p < 0.05) with 10 and 100 micrograms/ml of Toki-shakuyaku-san. Atractylodis Lanceae Rhizoma, Cnidii Rhizoma, Angelicae Radix, Paeoniae Radix and Alismatis Rhizoma, which are crude ingredients of Toki-shakuyaku-san, significantly (p < 0.01) enhanced the secretion of CINC/gro at concentrations of 100 micrograms/ml. The results of this study show that Toki-shakuyaku-san can stimulate the secretion of 17 beta-estradiol and stimulate the ovulatory process by stimulating the production of CINC/gro, IL-1 beta and TNF alpha in vitro. As a treatment for ovulatory disorders, Toki-shakuyaku-san may have stimulatory effects on both steroidogenesis and the ovulatory process.

Animals↗
PubMed2000

Gravimorphogenesis of Cucurbitaceae plants: development of peg cells and graviperception mechanism in cucumber seedlings.

We examined the effect of microgravity on the peg formation of cucumber seedlings for clarifying the mechanism of gravimorphogenesis in cucurbitaceous plants. The spaceflight experiments verified that gravity controls the formation of peg, hypocotyl hook and growth orientation of cucumber seedlings. Space-grown cucumber developed a peg on each side of the transition zone of the hypocotyl and root, indicating that on the ground peg formation is regulated negatively by gravity (Takahashi et al. 2000). It was found that the auxin-regulated gene, CS-IAA1, was strongly expressed in the transition zone where peg develops (Fujii et al. 2000). In the seedlings grown horizontally on the ground, CS-IAA1 transcripts were much abundant on the lower side of the transition zone, but no such differential expression of CS-IAA1 was observed in the space-grown cucumber (Kamada et al. 2000). These results imply that gravity plays a role in peg formation through auxin redistribution. By the negative control, peg formation on the upper side of the transition zone in the horizontally growing seedlings might be suppressed due to a reduction in auxin concentration. The threshold theory of auxin concentration accounted for the new concept, negative control of morphogenesis by gravity (Kamada et al. 2000). Anatomical studies have shown that there exists the target cells destined to be a peg and distinguishable at the early stage of the growth. Ultra-structural analysis suggested that endoplasmic reticulum develops well in the cells of the future peg. Furthermore, it was found that reorganization of cortical microtubules is required for the change in cell growth polarity in the process of peg formation. The spaceflight experiment with cucumber seedlings also suggested that in microgravity positive hydrotropic response of roots occurred without interference by gravitropic response (Takahashi et al. 1999b). Thus, this spaceflight experiment together with the ground-based studies has shown that cucumber seedling is an ideal for the study of gravimorphogenesis, hydrotropism and their interaction. Although peg formation is seen specifically in cucurbitaceous seedlings, it involves graviperception, auxin transport and redistribution and cytoskeletal modification for controlling cell growth polarity. This system could be a useful model for studying important current issues in plant biology.

Cucumis sativus↗
PubMed2000

Low density lipoproteins develop resistance to oxidative modification due to inhibition of cholesteryl ester transfer protein by a monoclonal antibody.

Although numerous studies have investigated the relationship between cholesteryl ester transfer protein (CETP) and high density lipoprotein (HDL) remodeling, the relationship between CETP and low density lipoproteins (LDL) is still not fully understood. In the present study, we examined the effect of the inhibition of CETP on both LDL oxidation and the uptake of the oxidized LDL, which were made from LDL under condition of CETP inhibition, by macrophages using a monoclonal antibody (mAb) to CETP in incubated plasma. The 6-h incubation of plasma derived from healthy, fasting human subjects led to the transfer of cholesteryl ester (CE) from HDL to VLDL and LDL, and of triglycerides (TG) from VLDL to HDL and LDL. These net mass transfers of neutral lipids among the lipoproteins were eliminated by the mAb. The incubation of plasma either with or without the mAb did not affect the phospholipid compositions in any lipoproteins. As a result, the LDL fractionated from the plasma incubated with the mAb contained significantly less CE and TG in comparison to the LDL fractionated from the plasma incubated without the mAb. The percentage of fatty acid composition of LDL did not differ among the unincubated plasma, the plasma incubated with the mAb, and that incubated without the mAb. When LDL were oxidized with CuSO4, the LDL fractionated from the plasma incubated with the mAb were significantly resistant to the oxidative modification determined by measuring the amount of TBARS and by continuously monitoring the formation of the conjugated dienes, in comparison to the LDL fractionated from the plasma incubated without the mAb. The accumulation of cholesteryl ester of oxidized LDL, which had been oxidized for 2 h with CuSO4, in J774.1 cells also decreased significantly in the LDL fractionated from the plasma incubated with mAb in comparison to the LDL fractionated from the plasma incubated without the mAb. These results indicate that CETP inhibition reduces the composition of CE and TG in LDL and makes the LDL resistant to oxidation. In addition, the uptake of the oxidized LDL, which was made from the LDL under condition of CETP inhibition, by macrophages also decreased.

Antibodies, Monoclonal↗
PubMed2000

A novel chiral stationary phase in HPLC: optical resolution of racemic amino compounds by (1-->6)-2,5-anhydro-3,4-di-O-ethyl-D-glucitol bound on silica gel.

[(1-->6)-2,5-Anhydro-3,4-di-O-ethyl-D-glucitol]-bound silica gel (CSP 4a), which was prepared by a two-step reaction, was used as a chiral stationary phase in high-performance liquid chromatography. The chiral recognition ability of the CSP 4a for racemates was examined using aq. NaClO4 (pH 2) and aq. NaClO4 (pH 2)/CH3CN as the eluents. For the resolution of amino acids and amino acid methyl esters, the D-isomers were eluted first. The separation factors of many of the racemates were 1.1-1.4, and the resolution factors were 0.59-7.75. This stationary phase showed a relatively high-resolving power toward compounds having a bulky substituent on the chiral carbon, such as phenylglycine and 1-(1-naphthyl)ethylamine.

Journal Article↗
PubMed1999

Direct interaction of the beta-domain of VHL tumor suppressor protein with the regulatory domain of atypical PKC isotypes.

VHL tumor suppressor protein contains two domains, alpha and beta. The alpha-domain is involved in the formation of a large protein complex suggested to be involved in ubiquitin-mediated protein degradation. However, the role of the beta-domain, which may recognize the target proteins for protein degradation, remains unknown. Here we report that the beta-domain interacts directly with atypical PKC isotypes, PKCzeta and PKClambda. Further, the regulatory domain of aPKC is sufficient for this direct protein-protein interaction. Since aPKC isotypes have been implicated in the regulation of cell growth and apoptosis, these results suggest that aPKC isotypes are potential direct target of the VHL beta-domain.

Amino Acid Sequence↗
PubMed1999

Human mismatch repair gene (hMSH2) product expression in relation to recurrence of transitional cell carcinoma of the urinary bladder.

BACKGROUND: Several convincing studies have shown that the hMSH2 gene plays major roles in mismatch repair by recognizing mismatched bases and preventing mutations during DNA replication. Loss of this function may result in the accumulation of DNA replication errors or even the mutator phenotype (which may be responsible for the multiple mutations required for multistep carcinogenesis), and it has been found to affect the prognosis of patients. Thus, the authors felt that it would be of interest to study the expression patterns of hMSH2 protein in malignant tumors and to assess the correlation of hMSH2 protein to various clinical and pathologic features in these patients. METHODS: The authors examined the expression patterns of hMSH2 protein in 115 patients with transitional cell carcinoma (TCC) of the urinary bladder by immunohistochemical technique using monoclonal antibody to hMSH2 protein. RESULTS: The group in which hMSH2 was preserved (>20% of nuclei were positive for staining by anti-hMSH2 antibody) included 86 of 115 (75%) of the TCCs, whereas the remaining 29 cases (25%) belonged to the group in which hMSH2 was preserved (< or = 20% of tumor nuclei were positive), including 2 negative cases. Univariate analysis indicated that reduced expression of hMSH2 protein was significantly more frequent in high grade tumors than in low grade tumors (P = 0.04). Furthermore, statistical multivariate analysis revealed that hMSH2 reduction was significantly related to the recurrence (P = 0.02). CONCLUSIONS: These results suggest that abnormal expression of hMSH2 protein might be involved in tumorigenic processes and in the progression of some TCCs, and that the loss of hMSH2 protein expression might be a useful predictor of recurrence of TCC.

Aged↗
PubMed1999

Cardioprotective effect of orally administered angiotensin-converting enzyme inhibitor against ischemia. Reperfusion injury in the isolated rat heart.

Angiotensin-converting enzyme inhibitors are reported to be cardioprotective against ischemia/reperfusion injury. Few studies have been made, however, on the cardioprotectiveness of orally administered angiotensin-conrerting enzyne inhibitors. Wistar rats were pretreated with oral delapril--30 mg/kg/day in the low-dose group and 90 mg/kg/day in the high-dose group--for one week. Cardiac function recovery was assessed after ischemia/reperfusion in the isolated working heart model. Rat hearts in the high-dose group were also reperfused with a solution containing nitro-L-arginine methyl ester, a nitric-oxide synthase inhibitor. Oral pretreatment of delapril did not affect baseline cardiac function. The percentage of cardiac output recovery for controls was 22 +/- 4.5%, for the low-dose group 44 +/- 6.5% (P < 0.05 versus controls), and for the high-dose group 76 +/- 5.3% (P < 0.001 versus controls and low-dose). Although coronary vascular resistance at the end of reperfusion showed no difference, mean coronary vascular resistance early after reperfusion was significantly lower (P < 0.0001) in both delapril groups than in control. In the high-dose group, reperfusion with L-NAME significantly increased coronary vascular resistance after ischemia/reperfusion and attenuated the cardioprotectiveness of delapril (P < 0.05 versus without nitro-L-arginine methyl ester). We thus found that oral administration of delapril was cardioprotective dose-dependently against ischemia/reperfusion injury. Nitric oxide appeared to be involved in the mechanism behind this cardioprotective effect.

Administration, Oral↗
PubMed1999

A spaceflight experiment for the study of gravimorphogenesis and hydrotropism in cucumber seedlings.

Seedlings of Cucurbitaceae plants form a protuberance, termed peg, on the transition zone between hypocotyl and root. Our spaceflight experiment verified that the lateral positioning of a peg in cucumber seedlings is modified by gravity. It has been suggested that auxin plays an important role in the gravity controlled positioning of a peg on the ground. Furthermore, cucumber seedlings grown in microgravity developed a number of the lateral roots that grew towards the water containing substrate in the culture vessel, whereas on the ground they oriented perpendicular to the primary root growing down. The response of the lateral roots in microgravity was successfully mimicked by clinorotation of cucumber seedlings on the three dimensional clinostat. However, this bending response of the lateral roots was observed only in an aeroponic culture of the seedlings but not in solid medium. We considered the response of the lateral roots in microgravity and on clinostat as positive hydrotropism that could easily be interfered by gravitropism on the ground. This system with cucumber seedlings is thus a useful model of spaceflight experiment for the study of the gravimorphogenesis, root hydrotropism and their interaction.

Cucumis sativus↗
PubMed1999

Binding of human secretory leukocyte protease inhibitor in uterine cervical mucus to immunoglobulins: pathophysiology in immunologic infertility and local immune defense.

OBJECTIVE: To identify an Fc receptor-like molecule in human cervical mucus. DESIGN: Controlled experimental laboratory study. SETTING: Department of Obstetrics and Gynecology, School of Medicine, University of Tokushima. PATIENT(S): Women undergoing treatment for infertility. INTERVENTION(S): Sodium dodecyl sulfate-polyacrylimide gel electrophoresis and Western blot were used for analysis. MAIN OUTCOME MEASURE(S): A water-insoluble protein with immunoglobulin-binding activity was purified from human cervical mucus by ammonium sulfate fractionation. The initial 21 amino acids of the N-terminus of the immunoglobulin-binding protein were determined and analyzed in a computer search for homology. RESULT(S): The purified fraction contained a 15-kd protein that binds immunoglobulin A, immunoglobulin M, and all subclasses of human immunoglobulin G as determined by Western blot analysis. The amino acid sequence of the N-terminus is identical to that of secretory leukocyte protease inhibitor. The capacity of secretory leukocyte protease inhibitor to bind immunoglobulins was confirmed by Western blot analysis. CONCLUSION(S): A component in human cervical mucus capable of binding immunoglobulins was identified as secretory leukocyte protease inhibitor. The capacity to bind immunoglobulins is a unique property of the protein, providing additional support for the contention that it plays an important physiologic role in local tissue defense mechanisms. It also is involved in the pathogenesis of immunologic infertility by trapping sperm in the cervical mucus.

Amino Acid Sequence↗
PubMed1999

Identification of the human sperm protein that interacts with sperm-immobilizing antibodies in the sera of infertile women.

OBJECTIVE: To identify the target antigen of sperm-immobilizing antibodies present in the circulation of infertile women. DESIGN: Laboratory research. SETTING: Academic research laboratory. PATIENT(S): Twenty-nine infertile women with sperm-immobilizing antibodies, 22 infertile women with other disorders, and 20 fertile women. INTERVENTION(S): Titers of antibodies to the sperm protein, rSMP-B, were determined by ELISA using as substrate the synthetic peptide segment (rSMP-230) that corresponds with the hydrophilic domain of rSMP-B. Tests for sperm immobilization and zona pellucida penetration were performed using the human IVF system. MAIN OUTCOME MEASURE(S): Human sera with sperm-immobilizing activity were assayed for the presence of antibodies to rSMP-230. Polyclonal antibodies to rSMP-230 were assessed for the same biologic activities as sperm-immobilizing antibodies. RESULT(S): Antibodies to rSMP-230 were detected in 10 (34%) of 29 sera obtained from women with immunologic infertility. In contrast, only one serum sample (2%) from women without sperm-immobilizing activity had a low titer of antibodies to rSMP-230. Polyclonal antibodies to rSMP-230 completely immobilized human sperm in the presence of complement and blocked sperm penetration across the zona pellucida. CONCLUSION(S): The human sperm protein, rSMP-B, probably is the target antigen of sperm-immobilizing antibodies.

Adult↗
PubMed1999

Quality of embryo does not affect the implantation rate of IVF-ET in infertile women with antisperm antibody.

OBJECTIVE: To determine whether low quality score of embryos and advanced maternal age affect the implantation rate in infertile women with sperm-immobilizing antibody. DESIGN: A retrospective study. SETTING: The IVF Unit of the Department of Obstetrics and Gynecology at Tokushima University Hospital. PATIENT(S): Four infertile groups were studied: 20 women with sperm-immobilizing antibodies; 169 with tubal; 129 with male factor; and 72 with unexplained etiology. INTERVENTION(S): All women were hyperstimulated with GnRH analogue and scheduled ovarian stimulation with FSH and hMG for oocyte retrieval. MAIN OUTCOME MEASURE(S): Relationship of quality of transferred embryos, implantation rate and maternal age among four groups of infertile couples. RESULT(S): In the antisperm group, the fertilization rate (57.6%) and mean (+/- SD) score of transferred embryos (5.4+/-1.9) were significantly lower than those in the tubal group (72.4% and 6.2+/-1.9, respectively). However, the implantation rate in the antisperm group (23.6%) was significantly higher than those in other three groups (tubal, 8.6%; male factor, 9.5%; unexplained, 7.6%). With advancing maternal age, the implantation rate decreased in the three comparative groups. In contrast, the implantation rate in the antisperm group did not decrease with advancing maternal age. CONCLUSION(S): Women with antisperm antibodies have several disadvantages to overcome in order to achieve successful IVF-ET, such as a low fertilization rate and poor quality of transferred embryos. However, a high implantation rate was observed in this group, even in women at advanced age. The occurrence of a cellular or humoral immune reaction against sperm may augment the uterine receptivity for the implantation of fertilized ova or blastocyst.

Adult↗
PubMed1999

Characterization of immunoglobulin binding factor in sputum from patients with chronic airway diseases.

OBJECTIVE: Immunoglobulin binding factor (IgBF) is known to bind immunoglobulin, to interact with anti-Fc gamma-III antibodies and to be present in the lower respiratory tract of normal healthy subjects. In this study, in order to clarify the role of IgBF in respiratory diseases, we investigated whether IgBF exists in the airway of patients with chronic airway diseases. METHODOLOGY: IgBF was measured in the sputum of 28 normal subjects and 59 patients with chronic airway diseases including 37 cases of chronic bronchitis, 18 bronchiectasis, and four diffuse panbronchiolitis by enzyme-linked immunosorbent assay. RESULTS: Immunoglobulin binding factor concentration in the sputum of patients with chronic airway diseases (purulent sputum, 50.2 +/- 8.2 microg/mL; mucoid sputum, 88.6 +/- 12.8 microg/mL) was higher than that in induced sputum of normal subjects (6.3 +/- 5.5 microg/mL; P < 0.001). Immunoglobulin binding factor level in mucoid sputum was significantly higher than that in purulent sputum (P < 0.05). A significant inverse correlation was shown between the IgBF level and the elastase activity in sputum, and the concentration of IgBF purified from seminal plasma was decreased by treatment with neutrophil elastase, indicating that IgBF might be degraded by elastase. In the gel filtration chromatography of both types of sputum, IgBF was eluted in a region corresponding to a molecular weight of 27 kDa as a single peak. Western blot analysis with a monoclonal antibody to IgBF indicated that IgBF in both types of sputum had a molecular weight of 27 kDa under non-reducing conditions and of 16 kDa under reducing conditions. CONCLUSION: These results demonstrate that a high level of IgBF is present in the respiratory tract of patients with chronic airway diseases and may be related to the pathogenesis of these diseases.

Adult↗
PubMed1999

Varicella-zoster virus-specific cellular immunity in subjects given acyclovir after household chickenpox exposure.

The time course of primary cell-mediated immune responses to varicella-zoster virus (VZV) among persons receiving acyclovir prophylaxis after exposure to chickenpox has not been well defined. Fifteen children who had household exposure to varicella received prophylactic acyclovir (40 mg/kg/day for 7-14 days after exposure) and were studied for development of both antibody and cell-mediated immunity (CMI) to VZV. Twelve developed antibodies and/or CMI; 10 had no symptoms and 2 manifested mild varicella. Two were already immune to varicella and had booster immune responses. One was not infected and subsequently developed full-blown varicella. Although acyclovir given after exposure to VZV is highly effective and does not appear to attenuate the immune response, it remains necessary to confirm whether, in the absence of clinical varicella, persons acquire specific immunity.

Acyclovir↗
PubMed1999

Development of a PCR test for rapid diagnosis of contagious equine metritis.

In order to establish a rapid diagnostic method for contagious equine metritis (CEM), we developed and evaluated a polymerase chain reaction (PCR) test. Species-specific PCR primer sets were derived from the DNA sequence of a cloned DNA fragment of Taylorella equigenitalis that did not hybridize with the genome of a taxomonically related species, Oligella urethralis. Single step PCR with primer set P1-N2 and two-step semi-nested PCR with primer sets P1-N2 and P2-N2 detected as low as 100 and 10 CFU of the bacteria, respectively. Single-step PCR detected T. equigenitalis from genital swabs of experimentally infected mares with sensitivity comparable to that of bacterial isolation. Furthermore, two-step PCR was more sensitive than the culture method. Upon examination of field samples, 12 out of 3,123 samples were positive by single-step PCR while only 2 were positive by bacterial culture. The 12 PCR-positive samples originated from 5 mares, of which 3 animals were considered to be carriers based on previous bacteriologic and serologic diagnoses for CEM. The PCR test described in this study would provide a specific and highly sensitive tool for the rapid diagnosis of CEM.

Animals↗
PubMed1999

[Acquired pulmonary stenosis caused by mediastinal mature teratoma: a case report].

A 13-year-old girl was admitted with a sudden onset of chest oppression. Mediastinal teratoma was suspected on chest X-ray and CT scan. A grade 2/6 systolic murmur was heard at the upper left sternal area and cardiac catheterization showed mild pulmonary stenosis. After resection of the tumor, the murmur disappeared and histopathological diagnosis was mature teratoma. This is a rare case report of pulmonary stenosis caused by mediastinal mature teratoma.

Adolescent↗
PubMed1999

Antisperm antibody: a monkey wrench in conception/magic bullet of contraception?

Antisperm antibodies can cause infertility by interacting with spermatozoa through immunoglobulin binding protein thereby blocking their penetrance of cervical mucus and/or by interfering with sperm-egg interaction. However, these antibodies appear not to be cytotoxic to embryos since a high implantation rate and consequently high pregnancy rate were achieved by IVF-ET treatment of women with antisperm antibodies. Also the finding that these antibodies do not appear to cause any deleterious clinical symptoms and have yet be associated with infertility suggested that sperm antigens are promising candidates in the development of immunocontraceptives. Some synthetic peptides corresponding to segments of human sperm antigens have effectively induced infertility in female rats when administered as an immunogen. Different peptides, adjuvants and routes of administration should be studied to determine the optimum conditions for inducing high antisperm antibody titers in the host. Moreover, identification of various steps and factors that are involved in regulating the production of antisperm antibodies such as immunoglobulin binding factor may open new paths in the treatment of immunological infertility and at the same time lead to a more effective immunocontraceptive.

Animals↗