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Biomedical subjects

M Kamada

Publications and source records attributed to M Kamada.

At least 271 records · Page 15Linked to original sources

Spontaneous intracranial hypotension successfully treated by epidural patching with fibrin glue.

We report a case of spontaneous intracranial hypotension due to a cerebrospinal fluid leak at the C2 level, which was successfully treated by epidural fibrin glue patching. Epidural blood patching was performed twice, first with 6 mL of autologous blood and then with 10 mL, but the intracranial hypotension was unresponsive. Although successful treatment of postdural puncture headache and persistent leak after intrathecal catheterization by epidural patching with fibrin glue has been reported, fibrin glue has not been previously applied in spontaneous intracranial hypotension. Our observation suggests that epidural patching with fibrin glue should be considered in patients with spontaneous intracranial hypotension, if epidural blood patching fails to resolve the symptoms.

Adult↗

Specific cytotoxicity of antibody to YAL-198, a sperm antigen peptide, to murine zygote.

Active immunization with the peptide segments rSMP-230 and YAL-198, corresponding to the hydrophilic extracellular domain of two human sperm antigens (rSMP-B and YWK-II, respectively), reduced fertility in female rats by different mechanisms. The anti-rSMP-230 antibody interferes with human and murine fertilization, and the anti-YAL-198 antibody blocks the development of mouse embryos. The authors examined in vitro at which stage the antibodies to rSMP-230 and YAL-198 were cytotoxic to murine embryos up to morula/blastocyst stage. Anti-rSMP-230 antibody was not cytotoxic to any stages. On the other hand, the anti-YAL-198 antibody arrested the growth of embryos at the 2-cell stage but not at more advanced developmental stages. When the anti-YAL-198 antibody was used, spotty staining was observed only on the surfaces of embryos that had arrested at the 2-cell stage. Unstained embryos, however, continued to develop normally. In contrast, the anti-rSMP-230 antibody stained murine sperm but failed to stain murine ova and embryos. The present results suggest that the human sperm components rSMP-B and YWK-II play important roles in sperm-egg interaction and early development of the embryo, respectively.

Animals↗

Progesterone accelerates the onset of capacitation in mouse sperm via T-type calcium channels.

This study was undertaken to evaluate whether progesterone induces capacitation of mouse spermatozoa. When sperm were evaluated by chlortetracycline staining, addition of progesterone significantly increased the proportion of spermatozoa exhibiting the B pattern at 60 minutes of incubation, compared with that before incubation (23 +/- 6.2% vs. 13 +/- 2.9%, p < 0.01) and that in hTF medium without progesterone (23 +/- 6.2% vs. 13 +/- 4.2%, p < 0.01). If the redistribution of proteins in sperm plasma membrane such as protein binding calcium ion were defined as capacitation, it could be said that progesterone promoted capacitation of mouse sperm. This progesterone-induced capacitation was prevented by depletion of extracellular calcium ion and addition of NiCl2, a T-type calcium channel blocker, although thapsigargin, an inhibitor of Ca2+-ATPase, did not increase the number of capacitated sperm (B pattern; progesterone vs. progesterone + depletion of calcium ion, 18 +/- 3.5% vs. 8 +/- 2.5%, p < 0.05, progesterone vs. progesterone + NiCl2, 20 +/- 3.8% vs. 6 +/- 5.2%, p < 01). Furthermore, genistein, a protein tyrosine phosphorylation inhibitor, inhibited progesterone-induced capacitation (B pattern; progesterone vs. progesterone + genistein, 20 +/- 3.8% vs. 11 +/- 2.4%, p < 01). In conclusion, progesterone induces capacitation in mouse sperm and this capacitation may be associated with calcium influx and tyrosine phosphorylation.

Animals↗

Sperm-immobilizing antibodies block capacitation in human spermatozoa.

Sperm-immobilizing antibodies block human fertilization by interfering with the acrosome reaction (AR). To clarify the mechanism of blockage of AR by sperm-immobilizing antibodies, the authors examined their effects on the increase of intracellular free Ca2+ concentration induced by follicular fluids (Ca2+ influx) in spermatozoa and on their capacitation. Sperm-immobilizing antibodies did not suppress Ca2+ influx induced by follicular fluid, but they inhibited capacitation of human spermatozoa. Namely delta%AR (%AR after addition of an AR inducer--%AR before treatment) induced by progesterone was significantly (p < .0001) lower when spermatozoa were incubated in human tubal fluid medium cotaining antibody-positive serum (1.2%), compared to that when incubated in control medium (19.2%). Furthermore, the proportion of both spermatozoa that became capacitated and ones that had become capacitated decreased significantly (p < .0001) after 2, 4, and 6 h of incubation in medium containing antisperm antibody-positive serum, compared to those of spermatozoa incubated in control medium. In conclusion, sperm-immobilizing antibodies may be closely related to their blockage of capacitation.

Acrosome Reaction↗

Concentration of granulocyte elastase in seminal plasma is not associated with sperm motility.

Although elastase could affect sperm motility in vitro, secretory leukocytes protease inhibitor (SLPI) prevents sperm from being attacked by elastase. The authors investigated the correlations of elastase level with sperm motility and SLPI level in vivo. Semen samples (n = 116) were collected and centrifuged after semen analysis. Elastase and SLPI levels were determined by an enzyme immunosorbent assay. Samples were classified by elastase levels into low (<250 ng/mL), moderate (250-1,000 ng/mL), and high elastase groups (> or =1,000 ng/mL). Elastase levels (range, 2.8-23,974.4 ng/mL) were not associated with sperm motility. The median SLPI level in the high elastase group was 15,900 ng/mL (range, 2.860-46,900 ng/mL). However, there was no significant correlation between elastase and SLPI levels in seminal plasma. Since SLPI forms a 1:1 complex with elastase, these results suggest that seminal plasma has a sufficient amount of SLPI to protect spermatozoa from elastase.

Enzyme Inhibitors↗

Postmenopausal changes in production of type 1 and type 2 cytokines and the effects of hormone replacement therapy.

OBJECTIVE: An appropriate defense against infective agents or malignant cells is attributed to the exquisitely balanced T helper 1 type (cellular) and T helper 2 type (humoral) immune reactions. We investigated the effect of hormone replacement therapy (HRT) on postmenopausal changes in the production of interferon (IFN)-gamma and interleukin (IL)-10, a type 1 and a type 2 cytokine, respectively. DESIGN: Both cytokines were measured by ELISA in the supernatant of lipopolysaccharide-stimulated whole blood cells from 72 untreated and 44 HRT-treated women. Thirteen women were examined before and during HRT. RESULTS: The production of IFN-gamma in women in their 40s and in postmenopausal women was significantly higher compared with that of younger women. However, IFN-gamma fell to the lowest level in the late postmenopausal stage, whereas the production of IL-10 increased gradually with age and in parallel with the postmenopausal period. Thus, in women in the mid-and late postmenopausal period, excessive production of type 2 cytokine (IL-10) compared with type 1 cytokine (IFN-gamma) occurred. The IFN-gamma levels of women on HRT were significantly lower than those of untreated women in the early and mid-postmenopausal stages, and IL-10 levels of women on HRT were significantly lower than those of untreated women in the mid-and late postmenopausal stages. HRT induced a significant decrease in the production of IL-10 and tended to lower the level of IFN-gamma. CONCLUSIONS: Production of IL-10 is augmented in postmenopausal women. HRT probably prevents postmenopausal women from an aberration of the immune system by improving the balance of type 1 and type 2 immune reactions.

Adult↗

Immunoglobulin-Fc binding factor in human male reproductive organs.

Human seminal plasma, testis, seminal vesicle, epididymis, and prostate contain a component with an estimated Mr of 20 kD that binds human immunoglobulin-Fc. The factor did not bind goat-IgG-Fc, immunoglobulins of human, rat, mouse, goat, horse, or rabbit sera and did not interact with antibodies raised against Fc gamma receptors. The present findings show that this Fc binding factor in seminal plasma is a secretory product of the testis and accessory sex organs. It binds human Ig-Fc but does not meet the criteria of an Fc receptor. Additional IgG-Fc binding proteins with estimated Mr of 90, 88, and 86 kD were detected in the prostate, testis, and seminal vesicle, respectively.

Genitalia, Male↗

Binding of a specific subclass of immunoglobulins by a human seminal plasma component.

Human seminal plasma contains a component that binds immunoglobulins (Ig). The Ig binding factor was purified by ammonium sulphate precipitation, preparative isoelectrofocusing and gel filtration chromatography and found to bind strongly human IgGl and mouse IgM. This seminal plasma component may possess immunosuppressive activity and may modulate the activities of the immunosurveillance system of the reproductive tract.

Animals↗

Identification of IgG and Fc-binding proteins in human seminal plasma and sperm.

Human seminal plasma contains two novel soluble proteins capable of binding IgG and Fc, but not Fab. The IgG- and Fc-binding proteins were identified by immunoblotting using IgG of various species, Fc and Fab fragments. Their estimated molecular sizes are 16-kD and 20-kD. The monoclonal antibody (MAb), Leu 11b, raised against Fc gamma RIII interacts with the 16-kD protein, whereas other mAbs (32.2, IV.3, and 3G8) raised against FcR did not. The 16-kD protein is capable of binding IgG of several species (human, mouse, rabbits, and goat), whereas the 20-kD protein interacted only with human IgG-Fc fragment. The 16-kD IgG and the 20-kD Fc-binding proteins were found in the PBS extract of human sperm. Human seminal plasma/sperm contain an IgG- and a Fc-binding protein with estimated Mr of 16 and 20 kD, respectively.

Antibodies, Monoclonal↗

Purification and characterization of a boar sperm protein interacting with immunoglobulins from an infertile woman.

Immunoglobulin G (IgG) fraction was prepared from a serum obtained from an infertile woman (IS) that induced sperm agglutination of human and boar sperm. The antisperm antibodies interacted with a 50-kD boar sperm protein, determined by immunoblot. The 50-kD protein was extracted with deoxycholate (DOC) and purified by affinity chromatography on concanavalin A column, ion exchange chromatography on CM52 column, affinity chromatography on IS IgG-protein G-agarose, and by preparative electrophoresis with electroelution. The purified 50-kD protein migrated as a single homogeneous band when analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and by Western blot. The production of antibodies against specific sperm proteins may be a cause of immunological infertility.

Animals↗

Immunoglobulin binding factor of seminal plasma: a secretory product of human prostate.

To determine the source of the immunoglobulin binding factor (IBF) in seminal plasma, extracts of testis and accessory male sex organs were prepared and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot. The detection reagents used were human and mouse serum Ig, monoclonal anti-Leu 11b antibodies, and polyclonal rabbit anti-IBF antibodies. Of the tissues examined, only the prostate, including benign hypertrophy and adenocarcinoma, contained IBF. These findings suggest that IBF is a secretory product of the prostate.

Humans↗

Immunoglobulin binding factor in human seminal plasma: immunological function.

Human seminal plasma contains a protein with an estimated molecular weight of 16 kd that binds serum immunoglobulin gamma (IgG) and is named IgG binding factor (IgBF). Purified IgBF specifically suppressed pokeweed mitogen-induced lymphocyte blastogenesis, having little or no effect on lymphocyte blastogenesis stimulated with phytohemagglutinin or Concanavalin A; antibody-dependent cell-mediated cytotoxicity; natural killer cell activity; or complement-dependent cytotoxicity of antibodies against sperm. It would appear that IgBF may suppress activation of B cells in the male and female genital tract.

Antibody-Dependent Cell Cytotoxicity↗

Complement-inhibiting activity of human seminal plasma and semen quality.

Human seminal plasma (SP) contains potent complement inhibitors. This study examined the complement-inhibiting activity of individual SP samples from 118 patients with infertility and analyzed them in relation to various semen parameters. When 25% complement-inhibiting activity was considered the cut off value, less than 1 SD unit from the mean percentage of inhibition of SP samples with normal semen quality, 32 samples (27%) showed low inhibiting activity. Among the lower group, incidences of patients with asthenozoospermia (66%) and oligozoospermia (31%) were significantly (p < .01) higher than those (36 and 10%) in the group whose SP showed significant inhibiting activity. Partial characterization revealed that the component responsible for complement inhibition was heat labile, trypsin resistant, high molecular weight (>10 kD) glycoprotein that can inhibit alternative as well as classical complement pathways. Furthermore, since in the majority of SP samples the anticomplementary activity was blocked by monoclonal antibody against membrane cofactor protein (MCP) or decay accelerating factor (DAF), the complement-inhibiting factors that were identified are likely to be MCP and/or DAF, which are known to be present in human SP. These results suggest that complement-regulatory proteins in SP such as MCP and DAF may protect sperm cells against complement attack in the male reproductive tract.

Complement Inactivator Proteins↗

Colocalization of immunoglobulin binding factor and prostate specific antigen in human prostate gland.

Immunoglobulin binding factor (IgBF) produced in the prostate is a useful marker for the diagnosis of prostatic tumor. IgBF was localized in the majority of epithelial cells of benign prostatic hypertrophy by an immunohistochemical technique. Prostate specific antigen (PSA), a known marker for prostatic cancer, was localized to all epithelial cells. Double immunolabeling of IgBF and PSA using fluorescent methods revealed that all epithelial cells producing IgBF were also immunopositive for PSA and some cells were positive only for PSA. The present findings suggest that the prostatic glands consist of two types of epithelial cells, one producing both IgBF and PSA and the other producing PSA alone.

Humans↗

Presence of immunoglobulin binding factor on human sperm surface as sperm coating antigen.

The presence of IgBF as a sperm-coating antigen was demonstrated by showing that anti-IgBF antibodies agglutinate and immobilize human sperm and by localizing IgBF on sperm surface by immunofluorescence staining. Several components interacting with sperm immobilizing antibodies, known to be involved in infertility, are sperm-coating antigens. Anti-IgBF antibody in vitro did not block the ability of human sperm to penetrate human zona pellucida and zona-free hamster egg. Anti-IgBF activity of sera obtained from infertile women did not correlate with the titers of anti-sperm antibodies measured by the sperm immobilization test. IgBF is a sperm-coating antigen and may play a role in suppressing antibody production against alloantigenic sperm in the female reproductive tract.

Animals↗

Semen analysis and antisperm antibody.

Evaluation of the fertilizing potential of sperm is an important procedure in in vitro fertilization and embryo transfer (IVF-ET) clinic, in order to avoid performing invalid conventional IVF-ET or unnecessary intracytoplasmic sperm injection (ICSI). However, none of the standard semen parameters are reliable indices in predicting IVF outcome. The test examining sperm-zona interaction is the best present method, though the short supply of the human zona component should be solved. IVF-ET treatment is useful for pregnancy in women having sperm immobilizing antibodies because it avoids exposing sperms to antibodies that block fertilization. ICSI should be used in immunologically infertile men diagnosed by specific method to demonstrate the in vivo exposure of sperms to antisperm autoantibodies that block fertilization.

Antibodies↗