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Biomedical subjects

T Osada

Publications and source records attributed to T Osada.

At least 109 records · Page 6Linked to original sources
PubMed1995

Cloning of boar SPMI gene which is expressed specifically in seminal vesicle and codes for a sperm motility inhibitor protein.

Boar semen contains a seminal plasma motility inhibitor (SPMI) that blocks the motility of demembranated-reactivated spermatozoa as well as of intact spermatozoa. In this paper, we describe the primary structure of SPMI, the coding of boar SPMI cDNA gene and its expression in various porcine tissues. Nucleotide sequence analysis of the 645-bp SPMI cDNA predicts a coded polypeptide of 137 amino acid residues which includes a 21-residue signal peptide and a 116-residue secreted protein. The amino acid sequence of SPMI was found to be highly homologous to AQN-3, a member of spermadhesin family proteins of boar that bind to spermatozoa. Expression of the boar SPMI gene detected by Northern blot analysis revealed that its expression is very abundant in seminal vesicles and specific to this tissue.

Amino Acid Sequence↗
PubMed1995

Is nestin a marker for chemosensory precursor cells?

The vomeronasal and olfactory systems are unique in that their chemosensory neurons undergo continuous neurogenesis after development. Immunoreactivity to nestin, a neuronal precursor marker protein, was investigated in the developing rat vomeronasal organ to determine its potential as a cell marker. From postnatal day 1 (P1) to P22, the distribution of nestin positive cells became progressively restricted to the area adjacent to the basement membrane. By P29, the vomeronasal organ reached structural maturity and only a few nestin positive cells were observed. Results suggest that nestin may be a useful marker for neuronal precursor cells in studies of neurogenesis and development of chemosensory systems.

Animals↗
PubMed1995

Prevention of bone loss by percutaneous estradiol implants in ovariectomized rats.

This study was conducted to investigate whether hydroxyapatite (HAP) is appropriate as a percutaneous drug carrier for estradiol (E2) for the suppression of bone loss. Ten-week-old female Sprague-Dawley rats were subjected either to bilateral ovariectomy (OVX) or to sham surgery (control). Ovariectomized rats were implanted percutaneously with E2-HAP disks containing low, medium or high doses of estradiol (50, 250, or 500 micrograms E2/rat, respectively). Ovariectomized rats without implant and OVX rats implanted only with HAP served as additional controls. All rats were sacrificed 90 days after surgery. At the end of the experiment, bone mineral density of the lumbar spine was measured by dual energy X-ray absorption, and serum E2 was assayed by radioimmunoassay. The bone mineral density of OVX and HAP-treated OVX rats decreased by 18% compared to sham surgery rats, but decreased by only 13, 7, and 3% in rats treated with 50, 250, and 500 micrograms E2/rat, respectively. The in vitro release of E2 from E2-HAP devices was determined by an HPLC method. Estradiol release from the HAP devices followed almost a zero-order kinetics. Estradiol remained intact in E2-HAP implants for up to six months when stored at 5, 25, and 40 degrees C. This study indicates that E2-HAP implants are effective in suppressing bone loss in the spine of OVX rats in a dose-dependent manner.

Animals↗
PubMed1995

Morphology of vomeronasal organ cultures from fetal rat.

The vomeronasal organs (VNOs) of rats were cultured from embryonic 15-day littermates on collagen-coated membrane in Dulbecco's modified Eagle's medium containing serum. The explants were observed sequentially and fixed at 4, 6, 8, 10 and 14 days in vitro (DIV). Organogenesis of VNOs and cell differentiation took place in vitro. Patterns of organogenesis of the VNO in vitro were different from those in vivo. Both sensory and supporting cells in the sensory epithelium had microvilli on their surface. Epithelial cells in aggregates of non-sensory epithelial cells had cilia and microvilli on their surface. Vomeronasal axons forming two to three large fascicles were seen originating from the VNO at 4, 6, and 8 DIV, and degenerated at 10 or 14 DIV. Glial cells (ensheathing cells) were observed in the fascicles. These morphological characteristics of VNO cells in vitro were similar to those observed in vivo.

Animals↗
PubMed1995

Coculture of the vomeronasal organ and olfactory bulb of the fetal rat.

The vomeronasal organ and the olfactory bulb of the rat were cocultured from 15-day embryo siblings on collagen-coated membrane in Dulbecco's modified Eagle's medium containing fetal calf serum, horse serum, and antibiotics. At 4 days in vitro (DIV), vomeronasal axons forming two to three large fascicles were seen originating from the explants of the vomeronasal organ. Differential axonal growth was observed. Some fascicles made connections with the explants of the olfactory bulb. Twenty percent of the cocultures studied here showed the formation of connections. At 6-10 DIV many fascicles that did not connect with the olfactory bulb had degenerated, and large fascicles that were connected with the olfactory bulb survived for more than 10 DIV. The formation of connections between the vomeronasal organ and the olfactory bulb in coculture favors the survival of large nerve fascicles, but it could not be determined whether or not the presence of the olfactory bulb affects the initial orientation of the fibers and fascicles from the explants of the vomeronasal organ.

Animals↗
PubMed1995

Differential binding patterns of three antibodies (VOBM1, VOBM2, and VOM2) in the rat vomeronasal organ and accessory olfactory bulb.

Immunohistochemical properties of monoclonal antibodies raised against the rat vomeronasal epithelium were examined in adult rats. Three monoclonal antibodies, VOBM1, VOBM2, and VOM2, reacted specifically to the luminal surface of the sensory epithelium of the vomeronasal organ. In addition, the reactivities of VOBM1 and VOBM2 were detected in the vomeronasal nerve layer and the glomerular layer of the accessory olfactory bulb. Electron-microscopic study revealed differential patterns of the immunoreactivity of the three antibodies to the microvilli of vomeronasal sensory epithelium. VOBM1 immunoreactivity was found on the microvilli of the supporting cells, whereas VOBM2 immunoreactivity was found on those of the sensory cells. VOM2 immunoreactivity was observed on the microvilli of both the sensory and supporting cells. These results suggest that the three antibodies recognize different antigens on the vomeronasal sensory epithelium. In particular, VOBM2 antibody appears to react to an antigen specific to the microvilli of the vomeronasal sensory cells.

Animals↗
PubMed1995

Effect of T-cell deficiency on the formation of periapical lesions in mice: histological comparison between periapical lesion formation in BALB/c and BALB/c nu/nu mice.

The role of T-cells in the development of periapical lesions was investigated immunohistochemically using 16 normal (BALB/c) mice and 16 nude (BALB/c nu/nu) mice (congenitally T-cell-deficient mice). The pulp chambers of maxillar first molars of all mice were opened, and the infiltrated immunocytes (anti-Thy1.2, -Lyt-1, -Lyt-2, -L3T4, -I-Ad, -IgG, and -IgM positive cells) were determined immunohistochemically at 2, 4, 6, and 8 wk after operation. Periapical lesions appeared at 2 wk in both mouse groups. Numerous anti-I-Ad positive-stained cells appeared at 2 wk, anti-I-Ad, -Thy1.2 (-Lyt-1, -L3T4), -IgG positive-stained cells appeared between 4 and 8 wk, and periapical lesions with bone resorption rapidly increased until 4 wk in normal mice. On the other hand in nude mice, only anti-I-Ad and -IgG positive cells were present from 4 to 6 wk, and the progress of periapical lesions with inflammatory cells stopped at 6 wk. Furthermore, numerous fibroblasts were found instead of inflammatory cells at 8 wk. These findings suggest that the progression of periapical lesions with bone resorption required helper T-cells and numerous immunoglobulin-producing cells.

Animals↗
PubMed1995

Transcatheter arterial embolization for massive bleeding from duodenal ulcers not controlled by endoscopic hemostasis.

BACKGROUND AND STUDY AIMS: We evaluated the efficacy of transcatheter arterial embolization (TAE) in patients in whom endoscopic hemostasis of a massively bleeding duodenal ulcer failed. PATIENTS AND METHODS: TAE was performed in 11 patients with endoscopically uncontrollable massively bleeding duodenal ulcers, and the results and long-time outcome were studied. Two additional cases of failed endoscopic hemostasis were treated surgically without TAE. The entire group of 13 patients represented 5% of endoscopically treated duodenal ulcers and 0.6% of all cases with upper gastrointestinal bleeding who underwent emergency endoscopy (n = 2073). All but one of these 13 patients had concomitant disease. RESULTS: Arteriograms performed before TAE revealed extravasation of contrast material around the gastroduodenal artery (GDA), the anterior superior pancreaticoduodenal artery (ASPD), or the posterior superior pancreaticoduodenal artery (PSPD) in six of 11 cases. We failed to stop the bleeding in one patient, in whom only the common hepatic artery side of the GDA bleeding site was embolized; this patient died. TAE was successful in the other ten patients, in whom the long stretch of the GDA, including the ASPD and PSPD, was embolized around the bleeding site. Two surgically treated patients died within a week. CONCLUSIONS: Our findings indicate that TAE may induce hemostasis in 90% of patients with serious concomitant diseases who have endoscopically uncontrollable massive bleeding from duodenal ulcers.

Aged↗
PubMed1995

Prevention of vascular graft infection by sisomicin incorporated into fibrin glue.

To examine the efficacy of sisomicin (SISO) incorporated into fibrin glue (FG) for the prevention of graft infection in animal models, the susceptibility to infection of Dacron grafts (control) and SISO-FG Dacron grafts following the inoculation of Staphylococcus aureus or S. epidermidis was compared. The results showed that SISO-FG Dacron grafts displayed resistance to graft infection.

Animals↗
PubMed1995

Effect of levofloxacin-albumin Dacron graft on graft infection.

The susceptibility of Dacron grafts to infection is compared with Dacron grafts applied with levofloxacin-bonded albumin (LVFX-ALB) following the inoculation of 10(7) cells Staphylococcus aureus in rats. Staphylococcus epidermidis was inoculated in the same manner. While the control grafts were infected at the time of removal, the LVFX-ALB Dacron grafts resisted infection, thus demonstrating their effectiveness.

Animals↗
PubMed1995

LHRH effects on hippocampal neurons are modulated by estrogen in rats.

The effect of luteinizing hormone releasing hormone (LHRH) on the neuronal activity of CA1 and CA3 regions of the hippocampus was studied by means of extracellular recordings in the castrated male, intact male, castrated female, and castrated female injected s.c. with 20 micrograms estradiol benzoate (EB) for 3 days. The basal firing rate of the CA3 neurons of castrated EB-treated female rats was significantly lower than that of the neurons in castrated EB-untreated female rats as well as male rats, either intact or castrated, whereas that of the CA1 neurons was not significantly different from castrated EB-untreated female rats. Iontophoretically applied LHRH predominantly resulted in facilitation of the neuronal firing in most of the animal groups. In the CA3 region of castrated EB-treated female rats, however, inhibition occurred in a large percentage of neurons, and the ratio of facilitation, inhibition and no response was significantly different from that in castrated EB-untreated female rats. In the CA1 region of castrated EB-treated female rats, the predominant effect of LHRH was facilitation and the ratio of facilitation, inhibition and no response was not significantly different from that in castrated EB-untreated female rats. These results suggest that LHRH is involved in increasing the neuronal activity of the CA3 region in the hippocampus, and estrogen reduces this LHRH action.

Animals↗
PubMed1995

Serum levels of soluble interleukin-2 receptor in chronic hepatitis C treated with interferon-alpha.

BACKGROUND: Serum levels of soluble interleukin-2 receptor (sIL-2R) seem to serve as a marker for the activation of T lymphocytes. The aim of this study was to evaluate the clinical significance of such levels in patients with chronic hepatitis C (CHC) treated with interferon. METHODS: We measured serum levels of sIL-2R in 37 patients with CHC before and after treatment with recombinant interferon-alpha. Serum receptor levels were then compared with the response of the hepatitis C virus (HCV)-RNA level in serum after interferon. RESULTS: Receptor levels were significantly higher in the patients with chronic persistent hepatitis and chronic active hepatitis than in normal controls (p < 0.01). There was a weak correlation between serum sIL-2R and alanine aminotransferase (ALAT) levels (r = 0.14, p = 0.010). Patients were then classified into three groups on the basis of the effect of interferon treatment on HCV-RNA levels in serum: sustained response (SR; n = 21), non-sustained response (NSR; n = 14), and nonresponse (NR; n = 2). Before and during interferon treatment the serum sIL-2R level remained increased in the SR group and in the combined groups with NSR or NR. However, after interferon was withdrawn, the serum sIL-2R decreased in the SR group but remained significantly increased in the combined response group (p < 0.01-0.05). CONCLUSION: This finding seems to reflect the disappearance of HCV-RNA from the serum of the patients with an SR, and monitoring of sIL-2R levels may therefore be of value as an adjunct to the measurement of serum ALAT and HCV-RNA in evaluating the response to the interferon therapy for CHC.

Adult↗
PubMed1995

[Significance of the motile sperm presented in the testis].

Generally it is believed that mammalian sperm mature during their transit through the whole epididymis. However spermatozoa aspirated from the epididymal duct or vasa defferentia have been recently reported to move actively in azoospermic patients with seminal tract obstruction. We examined whether the testicular sperm move which would provide useful information in the diagnosis of male infertility. Testicular biopsy materials were obtained from 38 testes of 37 patients as follows; 19 cases with azoospermia, 11 with oligozoospermia, and 8 orchiectomized for prostatic cancer (3), testicular cancer (2), epididymal abscess (1), and cryptorchid (2). All materials were obtained from either open biopsy or from the normal portion of the orchiectomized testis. The material was minced with a sharp knife or scissors in an Eppendorf tube containing Ham's F12 solution. Then a couple of drops of sperm suspension were placed on a warmed (37 degrees C) slide glass which was then covered with a coverglass. The prepared slide was immediately examined by phase-contrast microscopy. Another part was used for preparing a touch smear for confirming the presence of testicular sperm and then was fixed in Bouin's solution and stained with H-E. Spermatogenesis was evaluated by Johnsen's mean score (JMS). Eleven of the 19 azoospermic cases revealed the presence of testicular sperm, and ten of them demonstrated the presence of motile sperm. The mean JMS in these cases was 8.8 (normal spermatogenesis). After surgical exploration or vasography, these patients were diagnosed with obstructive azoospermia (post-vasectomy (4 cases), congenital absence of vas deferens (2 cases), secondary epididymal duct obstruction (4 cases)).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Clinical evaluation of a recurrent mode after treatment in patients with small hepatocellular carcinoma].

A total of 96 patients with small hepatocellular carcinoma (HCC) with a maximal diameter of below 2 cm were analyzed according to recurrent factors and recurrent modes after the first treatment. In this study, recurrences were divided into two groups based on the style of recurrences provisionally: intrahepatic metastases (IM, 35 cases) and multicentric recurrences (MC, 22 cases). In patients with IM, the majority of recurrences were observed within 2 years after the first treatment and the primary HCC lesions had strong relation to the degrees of malignancy. On the other hands, there were no association with recurrent intervals and the degrees of malignancy, although the recurrent rate was high in patients with anti-HCV in MC group. The prognosis after the second treatment in MC group was superior to that in IM group (p < 0.05). These results indicate MC group have a good prognosis if early detection and the second accurate treatment are performed.

Aged↗
PubMed1995

[Study of hepatocellular carcinoma type C by quantitation of serum HCV-RNA using branched DNA probe assay].

Serum HCV-RNA levels were determined by newly developed branched DNA probe (bDNA) assay in 87 patients with hepatocellular carcinoma (HCC), compared with 73 patients with chronic hepatitis active and 30 patients with liver cirrhosis. Patients with decompensated liver cirrhosis (LC-d) had a significant lower viremia (mean 3.2Meg.eq./ml, bDNA positive rate; 40%) than chronic hepatitis active (18.0; 64%) and compensated LC (LC-c, 17.9; 80%) (p < 0.05). Those data indicates that HCV replication may decrease as progression of LC. In contrast, there was no difference between the levels of HCC with LC-c (8.2; 85%) and LC-d (6.1; 89%), and their positive rate of bDNA assay were significantly higher than LC-d without HCC (p < 0.01). Therefore, patients undergoing LC in whom serum HCV-RNA sustained high level may correspond to the high risk group of HCC. In HCC of heavy drinker, serum HCV-RNA levels (11.3; 91%) were significantly higher than the levels (4.6; 79%) of HCC without heavy drink (p < 0.05). The result indicates that heavy drink may induced an increase in HCV replication.

Carcinoma, Hepatocellular↗