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Biomedical subjects

M Ozawa

Publications and source records attributed to M Ozawa.

At least 37 records · Page 2Linked to original sources
PubMed2001

Regulatory role of inhibin in follicle-stimulating hormone secretion and folliculogenesis in the guinea pig.

The effects of unilateral and bilateral ovariectomy and passive immunization against inhibin on follicle-stimulating hormone (FSH) secretions and follicular development in the guinea pig were investigated. Bilateral ovariectomy decreased plasma immunoreactive (ir-) inhibin rapidly and increased plasma FSH significantly. Unilateral ovariectomy decreased plasma ir-inhibin and increased plasma FSH temporarily, and doubled the number of ova released from the remaining ovary at the subsequent ovulation in guinea pigs. Injection of 1.0 ml inhibin antiserum significantly increased concentrations of plasma FSH at 6 hr onwards and the number of small follicles (100-200 microm in diameter) at 48 hr after the injection in guinea pigs bearing progesterone-containing implants. In vitro bioassay showed that inhibin antiserum could neutralize the suppression of ovarian homogenate on FSH secretion from cultured rat anterior pituitary cells. These results confirm the evidence that the ovary is the main source of inhibin secretion and both in vitro bioassay and passive immunization against inhibin show that the inhibin is a major regulator in the follicular development through FSH secretion in guinea pigs.

Animals↗
PubMed2001

Dynamic changes in plasma concentrations of gonadotropins, inhibin, estradiol-17beta and progesterone in cows with ultrasound-guided follicular aspiration.

To elucidate the effects of ultrasound-guided transvaginal follicular aspiration, plasma concentrations of FSH, LH, inhibin, estradiol-17beta and progesterone, and folliculogenesis were examined in Holstein cows. Four clinically healthy cows with regular estrous cycles were scanned by ultrasound per rectum once a week for 9 weeks before the commencement of follicular aspiration. All visible follicles were divided into 3 categories based on their sizes (2 < or = small < 5 mm; 5 < or = medium < 10 mm, large > or = 10 mm). The follicular aspiration was started at random during the estrous cycle and conducted under epidural anesthesia induced with 5 ml of 2% lidocaine once a week for 6 weeks. The average number of total visible follicles > or = 2 mm in diameter at 7 days after aspiration (21.7 +/- 7.4, n = 24) was similar to that before starting aspiration (26.7 +/- 10.5, n = 36). Plasma inhibin and estradiol-17beta declined and fell to a trough on 1.5 days and returned to pre-aspiration values by 5 days after aspiration. Plasma concentrations of FSH increased and reached peak levels between 1 and 1.5 days after aspirations. Plasma concentrations of LH also increased and reached peak levels between 0.5 and 1.5 days after aspirations. Both plasma FSH and LH had returned to pre-aspiration levels by 5 days after aspirations. Plasma concentrations of progesterone did not change with the follicular aspiration. These results demonstrate that follicular aspiration decreases plasma concentrations of inhibin and estradiol-17beta, which in turn leads to a rise in plasma concentrations of FSH and LH. It is suggested that marked increases in plasma concentrations of FSH and LH after the aspiration stimulate the development and maturation of a new cohort of follicles within one week in cows.

Animals↗
PubMed2001

Isolation and characterization of galectins in the mammalian retina.

PURPOSE: Previous studies have suggested that galectins may be involved in retinal adhesion and photoreceptor cell survival. To elucidate the underlying mechanisms, the authors isolated retinal galectins, determined their types and distributions, and investigated the validity of the hypothesis, using rat models. METHODS: An antibody was prepared against a bovine retinal lectin that was isolated by use of a lactose-agarose column. cDNA of the lectin was isolated by screening of a bovine retinal cDNA library, using the antibody, and then was sequenced. The cDNAs of rat retinal galectins were also isolated by means of polymerase chain reaction and used to produce an antibody against recombinant galectin-3. Using the described antibodies, the authors examined the distributions of galectins in bovine and rat retinas, morphologic changes of rat retinas induced by the antibodies, and distributional changes of galectins in constant-light-exposed rat retinas. RESULTS: The cDNAs of bovine galectin-1, rat galectin-1, and rat galectin-3 were isolated. Galectin-1 was found in various regions, including the retinal pigment epithelium, outer limiting membrane, and outer plexiform layer in bovine and rat retinas. Galectin-3 was increasingly detected in the cytoplasm of Müller cells after constant light exposure after an increase in its transcript. Retinal detachment and vacuolation of the outer plexiform layer were induced in rat eyes by intravitreous injection of the anti-galectin-1 antibody. CONCLUSIONS: Galectin-1 may be involved in adhesion of the photoreceptor and outer plexiform layers by interacting with glycoconjugates with beta-galactoside residues in the interphotoreceptor matrix and synaptic cleft matrix. Galectin-3 may increase in Müller cells of a degenerative rat retina, probably through endogenous anti-apoptosis.

Animals↗
PubMed2000

Central core disease and congenital neuromuscular disease with uniform type 1 fibers in one family.

We report a family in which the father had central core disease and his son had congenital neuromuscular disease with uniform type 1 fibers. This is the first report of such a combination. Although they had no recognized mutation in the ryanodine receptor gene, it is highly likely that the son also had central core disease but without core structures. The absence of cores may be due to the muscle sample or the young age of the patient since core structures have been reported to increase with age. Although the prevalence of core structures in individual muscles is unknown, there is a possibility of sampling error. In some patients, congenital neuromuscular disease with uniform type 1 fibers is closely related to or identical with central core disease.

Adult↗
PubMed2000

Indolyl carboxylic acids by condensation of indoles with alpha-keto acids.

The novel indole derivatives 2,2-bis(3,3'-indolyl)propionic acid (1); 1,1,1,-tris(3,3',3"-indolyl)ethane (2); and 2,2-bis(3, 3'-indolyl)isocaproic acid (3) were isolated from solvent extracts of indole-supplemented supernatants of Escherichia coli and corynebacteria. The compounds were also obtained by chemical synthesis: compounds 1 and 2 from indole and pyruvic acid and compound 3 from indole and alpha-ketoisocaproic acid, following incubation at 37 degrees C in aqueous medium. Tryptophan and pyruvic acid gave the novel 2-(2-tryptophanyl)lactic acid (4). The condensation reaction between indoles and alpha-keto acids was of general nature, and the mild reaction conditions suggested it may proceed in vivo. Examples for endogenous occurrence may be the neuro-degenerative diseases phenylketonuria and maple syrup urine disease, both characterized by elevated blood levels of alpha-keto acids.

Brevibacterium↗
PubMed2000

Role of neutrophils in induction of acute inflammation in T-cell-mediated immune dermatosis, psoriasis: a neutrophil-associated inflammation-boosting loop.

A growing body of evidence has indicated that T-cell-mediated immunity plays an important role in triggering and maintenance of psoriatic lesions. In this review we present our own experimental results as well as those from the literature related to the pathomechanism of the development of inflammatory changes in psoriatic lesions. First of all it is important to acknowledge the fact that psoriatic lesions are not uniform as assumed by many authors but that they are actually rather heterogeneous both clinically and histologically even within the same plaques. Lymphokines produced by activated T cells in psoriatic lesions have a strong influence on the proliferation of the epidermis, whose stimulated kertinocytes released several cytokines, which in turn enhance the activation state of T cells. Thus, they form a vicious cycle, a T-cell-mediated inflammation-sustaining loop. Although the interaction between T-cell-mediated immunity and epidermal keratinocytes may well explain the maintenance of background "chronic" inflammatory changes diffusely observed throughout psoriatic lesions, it is not enough to explain the island-like, "acute" inflammatory changes observed within and at the border of the plaque lesions. Characteristic neutrophil accumulation under the stratum corneum can be observed in the highly inflamed and therapeutically recalcitrant areas of psoriatic lesions. They are chemotactically attracted and activated there by synergistic action of chemokines, IL-8 and Gro-a released by the stimulated keratinocytes, and particularly C5a/C5a des arg produced via the alternative complement pathway activation possibly on the surface of corneocytes. In this review, we emphasize that the accumulation of neurophils is not simply a passive event. We think that those stimulated neutrophils are able to influence not only the growth and differentiation of epidermal keratinocytes but also the activation-state of T cells by aberrant expression of HLA-DR on their surfaces as well as by their effects. These T cells in turn influence the transepidermal neutrophil migration through the effect of their lymphokines on the keratinocyte production of pro-inflammatory mediators including C3. Therefore, we propose a neutrophil-associated inflammation-boosting loop that may well explain the localized "acute" inflammatory changes scattered over the "chronic" psoriatic plaques as well as in the acutely inflamed lesions of pustular psoriasis.

Acute Disease↗
PubMed2000

Primary malignant lymphoma of the central nervous system presenting with ascites and pleural effusion.

A 70-year-old woman was admitted to our hospital owing to ascites and pleural effusion. Though malignant cells (B-cell type lymphoma) were detected in both the ascites and pleural effusion, neither lymph node swelling nor a tumor was detected upon chest, abdominal and pelvic computed tomography (CT). After weekly THP-COP therapy for 8 weeks, the ascites and pleural effusion completely disappeared. Two years after the first admission, she was re-admitted because of a disturbance of consciousness, and a brain tumor was detected on CT scan. The immunohistological and genetic data for the brain tumor were identical to those of the malignant cells in the pleural effusion and ascites detected 2 years previously. Whereas the symptoms at onset of a primary lymphoma of the central nervous system (CNS) are usually neurological ones, in this rare case of primary CNS lymphoma, the symptoms at onset were the ascites and pleural effusion without neurological symptoms.

Aged↗
PubMed2000

Induction of superovulation by inhibin vaccine in cyclic guinea-pigs.

Experiments were conducted to determine whether neutralizing endogenous inhibin affects follicular development and ovulation rate in guinea-pigs. Eighteen female guinea-pigs bearing 4 week progesterone implants were divided into three groups. At 1 week after removal of the progesterone implants, the animals were given a s.c. injection of 1 ml placebo (saline in oil emulsion; control), or 25 or 50 micrograms inhibin vaccine three times at 4 week intervals. Blood samples were collected once a week throughout the experiment for measuring inhibin antibody titres. After the third injection of inhibin vaccine, blood samples and ovaries were collected on the morning of day 8 after the day of oestrus. Inhibin vaccine increased the ovulation rate in a dose-dependent manner (placebo: 4.2 +/- 0.4; 25 micrograms inhibin vaccine: 6.2 +/- 0.9; 50 micrograms inhibin vaccine: 9.8 +/- 0.9) without any effects on the duration of the oestrous cycle. The results also showed that active immunization against inhibin increased the number of atretic follicles of 300-399 microns in diameter on day 8 after ovulation. The present study is the first to show that the active immunization against inhibin may be a useful method for inducing multiple ovulation in guinea-pigs.

Analysis of Variance↗
PubMed2000

[Preliminary report: first identification of known mutation in the ryanodine receptor gene in a Japanese malignant hyperthermia pedigree].

In Japan, the rate of Ca-induced Ca release (CICR) using skinned fibers of skeletal muscle has been employed as a diagnostic test for malignant hyperthermia (MH) susceptibility, since most of the typical fulminant MH patients showed an enhancement of CICR rate. Recently the Ca releasing channel responsible for the CICR was reported to be mainly the ryanodine binding Ca protein which was identified as the causative site of MH muscle according to recent genetic studies. Among patients with enhanced CICR rate, one point mutation for Arg 2434 His was recognized in a family. Although this site is related to the central core disease (CCD), this pathological change could not be observed in this patient. This is the first report describing a gene mutation in a MH family identified in Japan.

Asian People↗
PubMed2000

[The countermeasure to pollinosis by a web site of Internet].

For the countermeasure to pollinosis, we opened "the web site of pollinosis by allergic group of otorhinolaryngology, Jikei Medical School" and provided the information of pollinosis for patients in the web site of internet from the spring of 1997. In the web site we kept to be informed of the pollen forecast, daily dispersed pollens, and medical information being renewed frequently of prevention and therapy for pollinosis. For the principle of therapy, we adopted the guideline for allergic rhinitis which was produced by Japan Allergic Societies and recommended visitors to get standard therapy for pollinosis. Consequently, the web site was accessed up to 160,000 times by the summer of 1999 and we received 204 medical questions by e-mail and answered to these all mails. We then made a questionnaire study after 3 each pollen seasons and received over 200 answers which showed that our fresh information was useful to decrease symptoms of pollinosis. These results show that information by web site seems to be useful for the countermeasure to pollinosis and will be more important to support medical treatment in hospitals in future.

Adolescent↗
PubMed2000

Down-regulation of E-cadherin by antisense oligonucleotide enhances basement membrane invasion of pancreatic carcinoma cells.

Pancreatic carcinoma shows a marked invasiveness around tissues lymph node and/or hematogenous metastases resulting in poor prognoses of the patients. We examined on whether E-cadherin is associated with these malignant behaviors of pancreatic carcinoma cells using a human pancreatic adenocarcinoma cell line, JHP-1. Immunohistochemically, E-cadherin expression of JHP-1 cells was remarkably inhibited by treatment with E-cadherin antisense oligonucleotide. By invasion-MTT assay, JHP-1 cells treated with E-cadherin antisense oligonucleotide showed a significant increase of invasiveness compared to those treated with the control oligonucleotide (P < 0.001), whereas the proliferation of JHP-1 cells was not affected by the presence of either E-cadherin antisense or control oligonucleotide. Thus, down-regulation of E-cadherin of pancreatic carcinoma cells induced the invasiveness into the basement membrane. These results suggest that the reduction in E-cadherin expression plays a key role not only in detachment of cell-cell adhesion but also in invasion and metastasis of pancreatic carcinoma cells.

Adenocarcinoma↗
PubMed2000

Isolation and characterization of mucinlike glycoprotein associated with photoreceptor cells.

PURPOSE: Although previous lectin-histochemical studies have shown that O-linked glycoproteins are distributed in cone pedicles and rod spherules, as well as in photoreceptors, including associated interphotoreceptor matrices (IPM), attention has been directed only to those in the IPM. In this study, cloning of the O-linked glycoproteins not only in the IPM but also in the region including the cone pedicles and rod spherules was attempted. METHODS: The cDNA for the core protein of the O-linked glycoprotein in the bovine retina was isolated by screening a bovine retinal cDNA library using a polyclonal antibody against the jacalin (a lectin specific for O-linked sugar residues)-binding glycoproteins (JBGPs) in the whole bovine retina. The expression of the JPGP core protein in the retina was examined by means of in situ hybridization histochemistry and immunohistochemistry. RESULTS: The cDNA was isolated and found to encode an entire core protein [predicted molecular mass (Mr): 101 kDa; rich in Ser and Thr; mucin-like] for the JBGPs with Mr of 120 and 135 kDa. The mRNA was expressed in both cone and rod photoreceptor cells. This protein was distributed in the cone pedicles and rod spherules as well as the photoreceptor layer. CONCLUSIONS: Mucinlike glycoproteins with Mr of 120 and 135 kDa may be synthesized in the cone and rod photoreceptor cells, respectively, and distributed not only in the photoreceptor layer (probably including the IPM) but also in the cone pedicles and rod spherules.

Amino Acid Sequence↗
PubMed2000

[The clinical statistics of the operations at the Department of Urology, Tokatsu Hospital: from 1994 to 1999].

We investigated the clinical statistics of the operations and inpatients since the establishment of the department in June 1994 up to May 1999. The total number of inpatients was 1,269 (1,047 males and 222 females), and a total of 1,098 operations were performed. Extracorporeal shock wave lithotriopy (ESWL) was also introduced in 1997, and in addition, it seemed that the number of operations and inpatients would be increasing in future.

Female↗
PubMed1999

p120(ctn) binds to the membrane-proximal region of the E-cadherin cytoplasmic domain and is involved in modulation of adhesion activity.

Cadherins are transmembrane glycoproteins involved in Ca(2+)-dependent cell-cell adhesion. Previously, we showed that the conserved membrane-proximal region of the E-cadherin cytoplasmic domain negatively regulates adhesion activity. In this report, we provide several lines of evidence that p120(ctn) is involved in this negative regulation. p120(ctn) binds to the membrane-proximal region of the nonfunctional carboxyl-terminally deleted E-cadherin protein. An additional internal deletion in this region prevented the association with p120(ctn) and activated the protein, as seen in an aggregation assay. Furthermore, the nonfunctional E-cadherin can be activated through coexpression of p120(ctn) proteins with amino-terminal deletions, which eliminate several potential serine/threonine phosphorylation sites but do not affect the ability to bind to cadherins. Finally, we show that staurosporine, a kinase inhibitor, induces an increased electrophoretic mobility of p120(ctn) bound to E-cadherin polypeptides, activates the nonfunctional E-cadherin protein, and converts the wild-type E-cadherin and an E-cadherin-alpha-catenin chimeric protein from a cytochalasin D-sensitive to a cytochalasin D-insensitive state. Together, these results indicate that p120(ctn) is a modulator of E-cadherin-mediated cell adhesion.

Animals↗
PubMed1999

312-nanometer ultraviolet B light (narrow-band UVB) induces apoptosis of T cells within psoriatic lesions.

Narrow-band (312 nm) ultraviolet B light (UVB) is a new form of therapy for psoriasis, but its mechanism of action is unknown. In a bilateral comparison clinical study, daily exposure of psoriatic plaques to broad-band UVB (290-320 nm) or 312-nm UVB depleted T cells from the epidermis and dermis of psoriatic lesions. However, 312-nm UVB was significantly more depleting in both tissue compartments. To characterize the mechanism of T cell depletion, assays for T cell apoptosis were performed on T cells derived from UVB-irradiated skin in vivo and on T cells irradiated in vitro with 312-nm UVB. Apoptosis was induced in T cells exposed to 50-100 mJ/cm2 of 312-nm UVB in vitro, as measured by increased binding of fluorescein isothiocyanate (FITC)-Annexin V to CD3(+) cells and by characteristic cell size/granularity changes measured by cytometry. In vivo exposure of psoriatic skin lesions to 312-nm UVB for 1-2 wk also induced apoptosis in T cells as assessed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) reaction in tissue sections, by binding of FITC-Annexin V to CD3(+) T cells contained in epidermal cell suspensions, and by detection of apoptosis-related size shifts of CD3(+) cells. Induction of T cell apoptosis could be the main mechanism by which 312-nm UVB resolves psoriasis skin lesions.

Adult↗
PubMed1999

Urocortin in human placenta and maternal plasma.

Plasma immunoreactive (IR-) urocortin (Ucn) and corticotropin-releasing factor (CRF) levels in pregnant women were measured by their specific radioimmunoassays after extraction. Although plasma IR-CRF levels were increased in pregnant women as compared to men and non-pregnant women, there was no difference of plasma IR-Ucn levels among groups. Ucn mRNA was detected in cytotrophoblasts and syncytiotrophoblasts by in situ hybridization. A reverse-phase high-performance liquid chromatography (HPLC) showed the major peak of IR-Ucn in placenta and plasma that had similar chromatographic mobility to synthetic Ucn1-40. These data suggest that Ucn is produced and processed into the same form of synthetic Ucn in placenta, but not secreted into maternal blood.

Adult↗