Biomedical subjects

Masaharu Kamada

Publications and source records attributed to Masaharu Kamada.

9 recordsLinked to original sources

PubMed2006

Changes in serum cytokine concentrations during the menopausal transition.

OBJECTIVE: The purpose of the present study was to clarify the changes in serum concentrations of 17 cytokines in healthy women during the menopausal transition by using a multiplexed cytokine assay and to clarify the associations of these cytokines with serum estradiol concentration. METHODS: Sixteen premenopausal, 54 perimenopausal and 52 postmenopausal women were enrolled in this study. Seventeen cytokines in serum samples were measured simultaneously using a Bio-Plex human cytokine 17-Plex assay. RESULTS: Serum IL-6 concentration showed a weak positive correlation with age (r=0.196, p<0.05). Postmenopausal women for whom less than 5 years had passed since menopause showed significant (p<0.05) increase in serum concentrations of IL-2, GM-CSF and G-CSF, while serum IL-4 concentration was significantly (p<0.05) increased in postmenopausal women for whom more than 5 years had passed since menopause. Serum estradiol concentration showed a significant negative correlation with serum IL-6 concentration and weak negative correlations with serum concentrations of IL-2, IL-8 and GM-CSF. CONCLUSION: We were able to simultaneously measure the levels of 17 cytokines using a highly sensitive cytokine assay, and we found that the changes in serum cytokine concentrations during the menopausal transition differed. We also found that serum IL-6 concentration during the menopausal transition was negatively correlated with serum estradiol concentration.

Adult↗

PubMed2006

Myeloid-related protein-8/14 is associated with proinflammatory cytokines in cervical mucus.

Myeloid-related protein-8 (MRP-8), MRP-14, and MRP-8/14 are found in a variety of inflammatory conditions and are involved in the host defense system. The objective of this study was to determine the concentrations of MRP-8, MRP-14, and MRP-8/14 in human cervical mucus and the associations between MRP-8/14 and proinflammatory cytokines. Samples of cervical mucus were obtained using a syringe from sexually active women (n=97) during the preovulatory phase. Samples from seven women were obtained using a swab placed in the cervical canal during the proliferative, preovulatory, and luteal phases. Concentrations of MRP-8, MRP-14, MRP-8/14, IL-1alpha, IL-6, IL-8, and granulocyte elastase were measured using an ELISA. The mean levels of MRP-8, MRP-14, and MRP-8/14 in cervical mucus were 1.87, 0.46, and 23.90microg/ml, respectively. The concentration of MRP-8/14 showed positive correlations with concentrations of IL-1alpha (p<0.0001), IL-8 (p<0.0001), and granulocyte elastase (p<0.0001). However, there were no significant differences in MRP-8/14 levels in the cervical mucus of each patient during the menstrual cycle. MRP-8/14 was mainly detected in human cervical mucus and showed a positive correlation with proinflammatory cytokines. The MRP-8/14 level in cervical mucus may be useful as a marker of inflammation of the uterine cervix.

Adult↗

PubMed2005

Antifertility effect of passive administration of antibodies to 80 kDa human sperm antigen and its synthetic peptides in male and female rats.

PROBLEM: A human sperm antigen of molecular size of about 80 kDa (80 kDa HSA) has been reported to be sperm-specific, conserved and responsible for inducing immunological infertility. The partial N-terminal amino acid sequence of 80 kDa HSA (peptide NT) and its peptides obtained by enzymatic digestion with endoproteinase Lys-C (peptides 1-4) and with endoproteinase Glu-C (peptides 5 and 6) did not show sequence homology with any of the proteins of the GenBank. The peptides NT, 1, 2, 3 and 4 were synthesized, conjugated to keyhole limpet hemocyanin and used as an immunogen to raise the antibodies in rabbits. Peptide 3 did not elicit significant antibody titer while peptides NT, 1, 2 and 4 elicited significant antibody titer and immunobiologically mimicked the native protein. METHOD OF STUDY: Effects of passive administration of two injections each of 200 microL of antibodies or 10 and 40 microg purified immunoglobulins to 80 kDa HSA, peptides NT, 1, 2 and 4 on fertility in male and female rats were investigated. RESULTS: Passive administration of antibodies to 80 kDa HSA and its peptides NT, 1, 2 and 4 resulted in agglutination of epididymal spermatozoa with loss of motility but had no effect on sperm count or weights of the reproductive organs. These animals failed to impregnate normal female rats. Passive administration of these antibodies to female rats also resulted in infertility. The presence of antibodies was detected by enzyme-linked immunosorbent assay in uterine secretions of animals treated with antipeptide antibody. The presence of agglutinated spermatozoa was observed in the post-coital vaginal smears of these animals. The immunized females were found to be ovulating normally and the number of corpora lutea were unaltered. Of the four antipeptide antibodies studied, antibodies to peptides NT and 1 were most effective in inhibiting fertility both in male as well as female rats. Hence, the antifertility studies were further confirmed by passive administration of 10 and 40 microg of purified immunoglobulins of antibodies to NT and 1, which resulted in a dose-dependent inhibition of fertility in male and female rats. CONCLUSIONS: The study demonstrated that the synthetic peptides of 80 kDa HSA immunobiologically mimicked the native protein and impaired fertility following passive administration of antipeptide antibodies and hence, suggested the suitability of synthetic peptides of 80 kDa HSA as candidates for development of antifertility vaccine.

Agglutination Tests↗

PubMed2004

Sperm-immobilizing antibodies suppress an increase in the plasma membrane fluidity of human spermatozoa.

OBJECTIVE: To clarify the mechanism by which capacitation is blocked by sperm-immobilizing antibodies, changes in the plasma membrane fluidity of human spermatozoa exposed to sperm-immobilizing antibodies were evaluated. DESIGN: In vitro cell culture study using human spermatozoa. SETTING: Department of Obstetrics and Gynecology, School of Medicine, The University of Tokushima. PATIENT(S): Semen samples were obtained from four healthy, fertile volunteers. INTERVENTION(S): The internalization of [3H]lyso-platelet activating factor (lyso-PAF) across the plasma membranes of human spermatozoa, which were exposed to sperm-immobilizing antibodies (antisperm group) or not exposed (control group), was measured at 20 and 60 minutes after the addition of a phospholipid probe using the modified albumin-back extraction method. MAIN OUTCOME MEASURE(S): The percentage of internalization of [3H]lyso-PAF across the plasma membrane of human spermatozoa. RESULT(S): Although the percentages of internalization of [3H]lyso-PAF (mean +/- SE) in the antisperm and control groups 20 minutes after addition of [3H]lyso-PAF were not significantly different (6.6% +/- 1.5% and 9.2% +/- 2.1%, respectively), at 60 minutes after the addition, the percentage in the antisperm group (9.0% +/- 1.3%) was significantly lower than that in the control group (13.4% +/- 1.3%). This inhibitory effect was diminished when spermatozoa exposed to sperm-immobilizing antibodies were incubated in an antibody-free medium. CONCLUSION(S): Sperm-immobilizing antibodies suppress the increase in internalization of an alkyl ester lysophospholipid probe in plasma membranes of human spermatozoa, and this inhibitory effect is reversible. Therefore, sperm-immobilizing antibodies suppress the fluidity of the plasma membranes of human spermatozoa, thus blocking capacitation.

Antibodies↗

PubMed2002

Production of human mast cell chymase in human myometrium and placenta in cases of normal pregnancy and preeclampsia.

OBJECTIVE: To investigate whether the human mast cell chymase-endothelin-1(1-31) system was present in human myometrium, chorion and umbilical cord in normal pregnancy. METHODS: Myometrium, placenta and umbilical cord were obtained from five normal pregnant women and 10 with preeclampsia. Each tissue was stained with antibodies against hMC and ET-1(1-31). RESULTS: Routine cells were located mainly around vessels. The number of hMC-positive cells and production of ET-1(1-31) were significantly higher in myometrium from patients with severe preeclampsia compared to those from normal pregnant women. In contrast, their numbers were significantly lower in placenta and umbilical cord in patients with severe preeclampsia. CONCLUSIONS: These results suggest that the hMC-ET-1(1-31) system is active in normal pregnancy. Overproduction of hMC and ET-1(1-31) in the myometrium may be involved in the pathogenesis of severe preeclampsia, and in such cases some defense mechanism may operate in the fetus to cope with the pathological effect of the hMC-ET-1(1-31) system.

Chymases↗

PubMed2002

The obesity in bilateral ovariectomized rats is related to a decrease in the expression of leptin receptors in the brain.

We investigated the expression levels of leptin receptors in the brain of ovariectomized (OVX) rats. The mean expression level of ob mRNA in adipose tissues of OVX rats was significantly (P < 0.01) lower than that in the SHAM operation group rats, and the mean body weight of OVX rats was significantly (P < 0.01) greater than that in the SHAM group rats. However, there were no differences between serum leptin concentrations in these two groups. The mean level of leptin receptor (OB-R) mRNA expression in the brain tissue and the mean level of long form type OB-R (OB-RL) mRNA expression in the hypothalamus of the OVX rats were significantly (P < 0.05) lower than those in the SHAM group rats. These changes were cancelled by supplementation with 17 beta-estradiol in OVX rats. These results suggested that not only changes in the expression level of ob mRNA in adipose tissue and the serum leptin concentration but also changes in the OB-R mRNA in the brain are involved in the body weight increase in OVX rats and that a decrease in OB-R makes transmission of signals to suppress the amount of food intake difficult, thus leading to an increase in body weight.

Animals↗

PubMed2002

Lysophosphatidic acid stimulates nuclear and cytoplasmic maturation of golden hamster immature oocytes in vitro via cumulus cells.

Lysophosphatidic acid (LPA), a member of the phospholipid autacoid family, is induced in incubated human follicular fluid by lysophospholipase D. It is well known that LPA functions as a growth factor and the hypothesis that LPA in human follicular fluid takes a part in meiosis of oocytes is quite plausible. We studied the effects of LPA on the maturation of golden hamster immature oocytes in vitro. Hamster oocytes with a germinal vesicle were cultured in Tyrode's albumin lactate pyruvate (TALP) medium with 10(-5) M LPA, 10 ng/ml epidermal growth factor (EGF), 30 ng/ml insulin-like growth factor-1, 1 ng/ml tumor growth factor-alpha or 1 ng/ml basic fibroblast growth factor. The nuclear maturation rates in the LPA and EGF groups were significantly higher than in the control group and the other growth factors did not show any stimulatory effect (LPA group; 74.3% [75/101], EGF group; 82.4% [89/108] vs. control group; 60.2% [59/98], p < 0.05, p < 0.01, respectively). When the cells of cumulus were removed, EGF and LPA did not increase the nuclear maturation rates. Cotreatment EGF and LPA did not significantly enhance the stimulatory effect observed with LPA alone on maturation in vitro. The penetration rate determined by the zona-free hamster oocyte test was significantly higher in the LPA group than in the control group (26.7% vs. 13.2%, p < 0.05) and was comparable with that of oocytes matured in vivo. In conclusion, LPA stimulates the nuclear and cytoplasmic maturation of hamster immature oocytes via cumulus cells.

Animals↗

PubMed2002

A repertoire of cytokines in human seminal plasma.

The pathophysiological significance of seminal cytokines in sperm function is still controversial. We determined the repertoire of cytokines in seminal plasma obtained from men with or without abnormalities in semen and assessed the pathophysiological significance of seminal cytokines. After conventional analysis of semen samples obtained from 86 men, levels of seminal cytokines (interleukin [IL]-1alpha, IL-2, IL-4, IL-6, IL-8, tumor necrosis factor-alpha [TNF-alpha], interferon-gamma, granulocyte colony-stimulating factor [G-CSF], macrophage CFS [M-CSF]) and granulocyte elastase were measured by an enzyme-linked immunosorbent assay. Leukocytospermia was defined as seminal plasma, which has > or =1000 ng/ml granulocyte elastase. Leukocytospermia was found in nine of 62 of the subjects in the normozoospermic group but in none of the 24 subjects showing abnormal sperm parameters (azoospermia, n=5; oligozoospermia, n=4; asthenozoospermia, n=15). The IL-8 level in the leukocytospermic group was significantly higher than those in the normal and oligozoospermic groups. IL-1alpha and TNF-alpha levels in the leukocytospermic group were significantly higher than those in the normal and asthenozoospermic groups. Although the G-CSF level in the leukocytospermic group was significantly higher than that in the normal group, high levels of M-CSF were detected in all groups. The IL-8 level was strongly correlated with IL-1alpha (r=0.935, P<0.0001) and G-CSF (r=0.916, P<0.0001) levels. Cytokines detected in seminal plasma are associated with the pathogenesis of leukocytospermia but not with the pathogenesis of asthenozoospermia and oligozoospermia.

Cytokines↗

PubMed2002

Involvement of carbohydrate molecules on zona pellucida in human fertilization.

Although the involvement of several receptors and ligand molecules in sperm-zona interaction in many species have been proposed, there has been a little analysis of the kinetics between these molecules during the interaction. In the present study, we applied the detection method using surface plasmon resonance (SPR) by a BIAcore apparatus for the analysis of the putative receptor-ligand interaction of sperm-egg binding. Mannose-BSA or [man](5)-[GlcNAc](2)-Asp was immobilized on the surface of a sensor chip. When concanavalin A (Con A) was delivered to each of two different sensor chips to evaluate their usefulness, the resonance signal after sample injection onto a [man](5)-[GlcNAc](2)-Asp-fixed chip decreased rapidly than the mannose-BSA-fixed chip. However, the amount of binding for Con A during the injection onto the [man](5)-[GlcNAc](2)-Asp-fixed chip was high. When acid sperm extracts (acid extracts) and fractions through a CM column, containing protease activity (protease fractions), were delivered to the mannose-BSA-fixed chip, the SPR signal during the injection was not obviously changed compared with that of the control. However, when sperm samples were delivered to the [man](5)-[GlcNAc](2)-Asp-fixed chip, the SPR response during the injection was enormous. These results suggest that the [man](5)-[GlcNAc](2)-Asp-fixed chip is more useful than the mannose-BSA-fixed chip for investigating the interactions with sperm extracts and that the sensitive method using SPR by a BIAcore apparatus is applicable for the analysis of the putative receptor-ligand interaction of sperm-egg binding.

Animals↗