Biomedical subjects

D Watanabe

Publications and source records attributed to D Watanabe.

At least 55 records · Page 3Linked to original sources

PubMed1998

A case of central carcinoma of the mandible arising from a recurrent odontogenic keratocyst: delineation of surgical margins and reconstruction with bilateral rectus abdominis myocutaneous free flaps.

A case of central carcinoma of the mandible arising from a recurrent odontogenic keratocyst is reported. A 38-year-old man was admitted to the Tokai University Hospital due to postoperative infection of a recurrent odontogenic keratocyst of the left mandible. He had had a cystectomy for an odontogenic keratocyst 4 years ago. The lesion revealed bony destruction of the mandible with worm-eating shaped margins with extension to the facial skin. A biopsy specimen revealed squamous cell carcinoma. The mandible was resected with facial skin and the sublingual space was dissected to preserve the lingual nerve. The oral and the facial resections were reconstructed with a titanium plate and bilateral rectus abdominis myocutaneous free flaps. The plate was removed due to infection around the margins and readjustment of the flaps was conducted 5 months after the surgery. He has not had a local relapse, metastasis, or incisional hernia for 8 months following surgery. Good occlusion has been attained by the residual mandible, and he is able to eat without any problems.

Adult↗

PubMed1997

The putative chaperone calmegin is required for sperm fertility.

The proper folding of newly synthesized membrane proteins in the endoplasmic reticulum (ER) is required for the formation of functional mature proteins. Calnexin is a ubiquitous ER chaperone that plays a major role in quality control by retaining incompletely folded or misfolded proteins. In contrast to other known chaperones such as heat-shock proteins, BiP and calreticulin, calnexin is an integral membrane protein. Calmegin is a testis-specific ER protein that is homologous to calnexin. Here we show that calmegin binds to nascent polypeptides during spermatogenesis, and have analysed its physiological function by targeted disruption of its gene. Homozygous-null male mice are nearly sterile even though spermatogenesis is morphologically normal and mating is normal. In vitro, sperm from homozygous-null males do not adhere to the egg extracellular matrix (zona pellucida), and this defect may explain the observed infertility. These results suggest that calmegin functions as a chaperone for one or more sperm surface proteins that mediate the interactions between sperm and egg. The defective zona pellucida-adhesion phenotype of sperm from calmegin-deficient mice is reminiscent of certain cases of unexplained infertility in human males.

Animals↗

PubMed1997

[Four cases of late infection following scleral buckling procedure].

We report four cases with late infection following a scleral buckling procedure. These cases were a 44-year-old male, a 52-year-old female, a 59-year-old male, and a 60-year-old male. All of these cases developed conjunctival injection, chemosis, and mucopurulent discharge 7 to 15 years after the procedure. The symptoms did not improve despite months of medical therapy, suggesting scleral buckle infection, and finally the buckling materials were removed. Solid silicone was used in 2 cases, and a sponge was used in 2 cases, with encircling elements in 1 case, and without encircling elements in 3 cases. Pus culture of the removal exoplant revealed fungaul infection in 2 cases. The others were negative, but bacterial infection was suspected from their clinical course and intraoperative findings. After removal of the buckles, the symptoms improved rapidly in all cases and there was no recurrence of retinal detachment. Scleral buckle infection should be suspected and removal of buckling materials should be considered, in cases with refractory conjunctival and scleral inflammation even years after scleral buckling procedure.

Adult↗

PubMed1996

Enhanced and accelerated lymphoproliferation in Fas-null mice.

Fas is a 45-kDa membrane protein that transduces an apoptotic signal. The mouse lymphoproliferation (lpr) mutation is a leaky mutation of Fas. In this study, we examined lymphocyte development in Fas-null mice generated by gene targeting. The Fas-/- mice progressively accumulated abnormal T cells (Thy1+, B220+, CD4-, and CD8-) and developed lymphadenopathy and splenomegaly, which were much more accelerated and pronounced than those in lpr mice. In addition, the Fas-null mice showed lymphocytosis, accompanied by lymphocytic infiltration in the lungs and liver. The number of apparently normal B cells also increased, and large amounts of immunoglobulins, including anti-DNA antibodies, were produced. Thymic clonal deletion, assessed by deletion of T cells reactive to mouse endogenous superantigens, was apparently normal in the Fas-/- mice, whereas the peripheral clonal deletion of mature T cells against a bacterial superantigen was impaired. These results suggested that Fas plays a decisive role in peripheral clonal deletion but not in negative selection in the thymus.

Animals↗

PubMed1996

Differential expression of oxytocin receptor mRNA in the developing rat brain.

The embryonic and postnatal localizations of oxytocin receptor mRNA in the developing rat brain were studied by in situ hybridization histochemistry. The hybridization signal was first detected at embryonic-day 13 in the primordium of the dorsal motor nucleus of vagus. Other positive regions progressively appeared after this time. The developmental profile of oxytocin receptor gene expression could be classified into two types; transient expression and constant abundant expression. The caudate putamen, cingulate cortex, the anterior thalamic nuclei, and the ventral tegmental area belonged to the first type. In these regions, oxytocin receptor mRNA was expressed intensely only during the early postnatal period. The regions such as the anterior olfactory nucleus, tenia tecta, some amygdaloid nuclei, piriform cortex, the ventromedial hypothalamic nucleus, subiculum, the prepositus hypoglossal nucleus and the dorsal motor nucleus of vagus showed constant expression of oxytocin receptor mRNA at high levels throughout development and in the adult. These findings concurred well with those of the ontogenic studies using receptor binding autoradiography with a ligand specific to oxytocin. Thus, the transient expression of oxytocin receptor during development was regulated at the transcriptional level in several brain regions, and oxytocin may play a role in brain development as well as in neural transmission in the mature brain.

Animals↗

PubMed1996

Random and imprinted monoallelic expression.

This review has surveyed the current literature on random and imprinted monoallelic expression from the unusual perspective of considering that these two forms of monoallelic expression (MAE) may be regulated by similar mechanisms. The true extent of genes which show MAE is not yet known. Imprinted MAE is thought to involve 0.1-0.2% of mammalian genes, while the number of genes in the random MAE category cannot at present be predicted since very few genes have been examined with assays that distinguish parental transcripts in single cells. The perspective adopted in this review is speculative since only one gene (XIST) is known which displays both random and imprinted MAE. However, a recent report that H19 may also show random allelic expression, suggests that MAE should be further investigated as a gene regulation mechanism in mammals.

Alleles↗

PubMed1996

Characteristic localization of gp130 (the signal-transducing receptor component used in common for IL-6/IL-11/CNTF/LIF/OSM) in the rat brain.

The localization of gp130, the signal transducing receptor component used in common for interleukin (IL)-6, IL-11, ciliary neurotrophic factor (CNTF), LIF and OSM, in the rat brain was demonstrated by immunohistochemistry using an antibody specific to gp130. The gp130 immunoreactivity was observed in both glial and neuronal cells. Two distinct neuronal staining patterns were observed. The first showed neuropil staining, observed mainly in telencephalic structures including the hippocampus, cerebral cortex and caudate-putamen. The second pattern was observed on the cytoplasmic membrane of neuronal somata and was found primarily in the lower brainstem, in the large neurons of the reticular formation, and in spinal and cranial motor neurons. Electron-microscopic analysis revealed that both types of gp130 immunoreactivity were primarily associated with the cytoplasmic membrane and were not localized exactly at synaptic sites. Further, gp130 immunoreactivity was also observed in the oligodendrocytes and subependymal zone. These widespread but characteristic patterns of gp130 immunoreactivity overlap well with those of IL-6 receptor and CNTF alpha chains, suggesting a role of cytokines and growth factors such as IL-6 and CNTF via gp130 in certain specific regions of the brain.

Amino Acid Sequence↗

PubMed1996

The fractional inhibitory concentration index of antimicrobial agents for bacteria and Mycoplasma isolated from the nasal swabs of cattle with respiratory diseases.

We investigated the effect of thiamphenicol plus lincomycin (TP + LCM) and thiamphenicol plus tylosin (TP + TS) combinations using checker board method on the growth of Pasteurella (P.) multocida, P. haemolytica and Mycoplasma (M.) bovis by calculating the fractional inhibitory concentration index (FIC index). The results showed that the FIC indexes of the TP + LCM combination for P. multocida, P. haemolytica and M. bovis were 0.36 +/- 0.10, 0.72 +/- 0.09 and 0.81 +/- 0.18, respectively. The FIC indexes of the TP + TS combination for P. multocida, P. haemolytica, and M. bovis were 0.79 +/- 0.20, 0.66 +/- 0.11 and 0.32 +/- 0.14, respectively. Thus, these combinations are assumed to have a more synergistic or additive effect on bacteria growth than a single antimicrobial agent.

Animals↗

PubMed1995

Characterization of the testis-specific gene 'calmegin' promoter sequence and its activity defined by transgenic mouse experiments.

We have cloned the genomic DNA of calmegin [(1992) J. Biol. Chem. 269, 7744-7749] and analyzed its promoter region. It contained GC-rich sequences and potential binding sites for AP 2 and Sp 1, but lacked the TATA sequence. The 330 bp 5' flanking sequence of calmegin genomic DNA fused with the CAT gene was used for the study of promoter activity in transgenic mice. The CAT gene activity was detected exclusively in testes, indicating that the 330 bp calmegin 5' sequence was sufficient for the testis-specific expression. The existence of testicular nuclear factors specifically bound to the putative promoter sequence was also demonstrated.

Animals↗

PubMed1995

Constitutive activation of the Fas ligand gene in mouse lymphoproliferative disorders.

Mice homozygous for lpr (lymphoproliferation) or gld (generalized lymphoproliferative disease) develop lymphadenopathy and splenomegaly and suffer from autoimmune disease. The lpr mice have a defect in a cell-surface receptor, Fas, that mediates apoptosis, while gld mice have a mutation in the Fas ligand (FasL). Northern hybridization with the FasL cDNA as probe indicated that the cells accumulating in lpr and gld mice abundantly express the FasL mRNA without stimulation. By means of in situ hybridization and immunohistochemistry, we identified the cells expressing the FasL mRNA as CD4-CD8- double negative T cells. The T cells from lpr mice were specifically cytotoxic against Fas-expressing cells. Since FasL is normally expressed in activated mature T cells these results indicate that the double negative T cells accumulating in lpr and gld mice are activated once, and support the notion that the Fas/FasL system is involved in activation-induced suicide of T cells. Furthermore, the graft-versus host disease caused by transfer of lpr bone marrow to wild-type mice can be explained by the constitutive expression of the FasL in lpr-derived T cells.

Animals↗

PubMed1995

Characterization of a novel spermatogenic cell antigen specific for early stages of germ cells in mouse testis.

To study the mechanism of spermatogenesis during the premeiotic phase, a hybridoma producing monoclonal antibody (mAb) specific for early stages of spermatogenic cells was obtained. In immunohistochemical staining of adult testis, this mAb, designated as EE2, was able to react with type A to B spermatogonia and early meiotic cells, but not with Sertoli cells, Leydig cells, and other somatic tissues. Precursor cells of type A spermatogonia (gonocytes) were also positive for EE2 in perinatal mouse testis. The antigenic molecule recognized by mAb EE2 was a novel glycoprotein with molecular weight of 114 kDa, which had affinity with Con A and WGA lectins, and was susceptible to N-glycanase, suggesting the presence of asparagine-linked sugar chains. Furthermore, EE2 antigen was found to localize on the germ cell surface. The specific expression of this antigenic molecule suggests that it may play an important role in early spermatogenesis, of which only a little information is available at present.

Animals↗

PubMed1995

Expression of Fas in B cells of the mouse germinal center and Fas-dependent killing of activated B cells.

Fas is a cell-surface protein of 45 kDa. Binding of the Fas ligand (FasL) to Fas induces apoptosis in Fas-bearing cells. Analysis of mouse mutants in either Fas or FasL have indicated that the Fas system is involved in apoptosis of lymphocytes. To identify the cells expressing Fas, mouse spleen sections were analyzed by in situ hybridization and immunohistochemistry. Fas mRNA was detected in the T cells of the inner region of the periarterial lymphatic sheath and the inner lumen of the marginal zone. The cells in the outer region of the periarterial lymphatic sheath weakly expressed Fas mRNA, whereas it was abundant in the B cells of germinal centers. Immunizing mice with keyhole limpet hemocyanin induced formation of many germinal centers in the spleen. The B cells in the activated germinal center expressed abundant Fas and underwent apoptosis. The in vitro activation of splenocytes with lipopolysaccharide induced Fas expression in B cells and the B cells became sensitive to the Fas-mediated apoptosis. These results suggest that Fas is involved in the activation-induced death of B cells.

Animals↗

PubMed1995

Insulin-like growth factor-I and transforming growth factor-alpha stimulate differentiation of type A spermatogonia in organ culture of adult mouse cryptorchid testes.

This study assessed the effect of growth factors on testicular germ cell differentiation in vitro. Testicular fragments of experimentally prepared cryptorchid testes of adult mice were cultured for 9 days in serum-free media containing various concentrations of IGF-I, TGF-alpha, FGF, and PDGF. Their histology was then examined under a light microscope. Each type of germ cell and mitotic cell in the seminiferous tubules was counted per 1000 Sertoli cells. IGF-I at a concentration of 10 ng/ml induced maximal differentiation of type A spermatogonia. TGF-alpha at concentrations ranging from 1 to 10 ng/ml also stimulated differentiation, whereas FGF and PDGF did not show any stimulation of spermatogonial differentiation in this experimental system.

Animals↗

PubMed1995

[Analysis of relationship between personality and emesis gravidarum in pregnant women].

The relationship between personality types and the symptoms of emesis gravidarum in pregnant women was analyzed by means of the Cattel personality test (revised by Nishizono) performed in early and mid pregnancy. Personality types were classified into five from cyclothymia A to schizothymia E. As for emesis, the patients were also classified into three groups, severe (35), mild (41) and none (19), according to the severity and duration of the symptoms. As a result, there was no significant difference between the types and the symptoms, but significant differences were seen in interpersonal attitudes, especially in sociality and dominative propensity, which were constituents of the personality type. The results of the analysis suggested that the patients who revealed disunification tended to express strong emesis as a somatic language. These results therefore indicate the necessity for counseling about personality without simply explaining it as their predisposing constitution, when we encounter strongly emetic pregnant women.

Female↗

PubMed1994

Molecular cloning of a novel Ca(2+)-binding protein (calmegin) specifically expressed during male meiotic germ cell development.

During mammalian spermatogenesis, many specific molecules are expressed. We have recently identified a 93-kDa male meiotic germ cell-specific antigen (Meg 1) exclusively expressed in germ cells from the pachytene spermatocyte to the spermatid stage using the monoclonal antibody TRA 369 (Watanabe, D., Sawada, K., Koshimizu, U., Kagawa, T., and Nishimune, Y. (1992) Mol. Reprod. Dev. 33, 307-312). In this study, we cloned a cDNA representing this antigen from a mouse testis cDNA expression library, using the monoclonal antibody TRA 369. Northern blotting showed that this transcript was 2.3 kilobases in length and was expressed only in the testis and not in other somatic tissues or in the ovary. The expression of the mRNA was first detected at the pachytene spermatocyte stage of male germ cell development, and this expression was correlated with the expression of the protein. Sequence analysis of the cDNA revealed that the predicted protein consists of 611 amino acids, including a hydrophobic NH2 terminus characteristic of a signal peptide, two sets of internal repetitive sequences (four repeats of IPDPSAVKPEDWDD and GEWXPPMIPNPXYQ), and a hydrophilic COOH terminus. The deduced amino acid sequence has 58% homology with dog calnexin (the ER membrane phosphoprotein of pancreatic cells) and significant partial homology with calreticulin (high affinity Ca(2+)-binding protein of the ER membrane) at the repetitive sequence. Furthermore, we demonstrated the 45Ca2+ binding ability of this antigen by a 45Ca2+ overlay assay, and the name calmegin is proposed for this antigen. Calmegin is a novel Ca(2+)-binding protein that is specifically expressed in spermatogenesis. The highly regulated, specific, and abundant expression of calmegin suggests that it has important roles in spermatogenesis.

Amino Acid Sequence↗

PubMed1994

Hepatitis B surface antigen, hepatitis C virus antibody, body mass index, and alcohol drinking among workers with elevated serum alanine aminotransferase.

METHODS: We conducted a case-control study on liver diseases among Japanese workers to examine associations between elevated serum alanine aminotransferase (alanine aminotransferase value > or = 50 IU/liter) and selected factors such as hepatitis B surface antigen positive, hepatitis C virus antibody positive, body mass index, and alcohol drinking. Out of 3,738 workers (1,477 males and 2,261 females) in a supermarket chain, 91 workers with an elevated serum alanine aminotransferase value (> or = 50 IU/liter) were classified as cases and 182 workers with normal serum alanine aminotransferase value and without an episode of blood transfusion were randomly selected as controls. RESULTS: Prevalence rates of hepatitis B surface antigen positive and hepatitis C virus antibody positive were 4.4 and 23.1% among the overall cases, 2.9 and 11.8% among the cases with 100 > alanine aminotransferase value > or = 50, and 8.7 and 56.5% among the cases with alanine aminotransferase value > or = 100. A logistic regression analysis was conducted. Odds ratios were 4.94 for hepatitis B surface antigen positive (P < 0.05) and 77.19 for hepatitis C virus antibody positive (P < 0.001). Odds ratios for body mass index increased with increasing body mass index values; 3.32 for 26 > body mass index > or = 24 (P < 0.01) and 5.03 for body mass index > or = 26 (P < 0.001). No increased risk was observed among regular drinkers of less than 27 g/day of ethanol (odds ratio is 0.23) or of 27-53 g/day of ethanol (odds ratio is 0.47). A slightly increased odds ratio of 1.35 was observed among regular drinkers of 54-81 g/day of ethanol, but this was not statistically significant. CONCLUSIONS: Our results suggest that hepatitis C virus and high body mass index are predominant factors in elevated serum alanine aminotransferase levels among Japanese workers, while alcohol drinking is a minor factor.

Adult↗

PubMed1994

Laboratory correlates of chemoimmunotherapy with low-dose recombinant interleukin-2 and mitomycin C in patients with advanced carcinoma.

Based on our clinical findings that the ability of cancer patients to generate lymphokine-activated killer (LAK) cells was remarkably augmented after mitomycin C (MMC) administration, we designed a treatment regimen that consisted of MMC 12 mg/m2, i.v. on day 1 and recombinant interleukin-2 (IL-2) 700 U/m2, i.v. every 12 hr from day 4 through day 8. Of 29 patients with advanced carcinoma treated with this regimen, 10 had a partial response (PR) and 4 had a minor response. The correlation of hematological and immunological changes associated with this treatment with the antitumor response to this therapy was investigated. Pretreatment values of total white blood cell and lymphocyte counts, and the level of increase of eosinophil counts in responder patients who showed a PR, were significantly greater than those in nonresponder patients. However, there was no correlation between clinical response and cytotoxic activities of peripheral blood mononuclear (PBM) cells, including NK and LAK activity, and the ability to generate LAK cells after the treatment. The capacity of adherent cells in PBM to produce IL-1-beta was increased after the treatment in both responders and nonresponders, whereas IL-1-alpha production was not increased. In addition, a significant increase in the ability to produce TNF-alpha was observed only in responders, indicating the correlation of TNF-alpha production with clinical response to this therapy. Since these correlations had been reported in the previous studies using IL-2, the present results suggested that the therapeutic effectiveness of this therapy against advanced carcinoma, is due to IL-2 probably augmented by its combination with MMC. In addition, these parameters might be predictive of therapeutic efficacy of this treatment.

Adult↗

PubMed1993

A novel stage-specific differentiation antigen is expressed on mouse testicular germ cells during early meiotic prophase.

A murine cell surface antigen exhibiting stage-specific expression during spermatogenesis was detected with two monoclonal antibodies (mAbs), designated BC7 and CA12. In mouse testis, these mAbs recognized a small population of cells located near the periphery of seminiferous tubules at stages XII and I-VI, and these spermatogenic cells were identified as zygotene and early pachytene spermatocytes. Expression of the antigens was transient and was not detected in germ cells at more advanced stages of spermatogenesis such as late pachytene spermatocytes and round spermatids. Immunoprecipitation and immunoblotting studies showed that both mAbs CA12 and BC7 reacted with the same antigenic molecule, which had an estimated molecular mass of 95 kDa. CA12/BC7 antigen, detected in plasma membrane fraction, was a glycoprotein with sialic acid residues and had affinity with WGA lectin. Furthermore, intraperitoneal injection of mAb BC7 caused an apparent spermatogenic disturbance in prepubertal mice. These results suggested that CA12/BC7 antigen, a novel cell surface glycoprotein, is an essential molecule that plays an important role during early meiotic prophase of spermatogenesis.

Animals↗