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Biomedical subjects

M Nagano

Publications and source records attributed to M Nagano.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Transurethral resection of the prostate for patients with dementia].

During the period from July 1995 to June 1996 we performed transurethral resection of the prostate (TURP) on 824 patients with benign prostatic hyperplasia (BPH). Among them, 13 were dementia patients between 74 and 96 years old; they presented with urinary hesitancy in 6, retention in 4, frequency in 2 and incontinence in 1 patient. Past history included stroke in 7, hypertension in 6, pulmonary tuberculosis in 4, diabetes in 3, asthma in 2, angina pectoris in 1, Parkinson's disease in 1, pneumonia in 1, and hepatitis in 1. Careful preoperative examination revealed that they were proper candidates for TURP. They underwent TURP under spinal anesthesia. The mean operative time was 34 min, ranging from 20 to 60 min. The adenoma resected weighed 24 g on the average, ranging from 7.5 to 48 g. During surgery, although hypotension was noted in 2 patients, there was no serious morbidity. Their mental condition was well controlled with ketamine and diazepam during and after surgery. Postoperative complications included acute myocardial infarction in 1, multiple gastric ulcer in 1, and decubitus in 1. None died within 3 months after TURP, 3 died there after, and 10 patients were alive at the mean follow-up period of 26 months. Six patients reported good urination, 3 reported some improvement in urination after surgery, although requiring intermittent catheterization and 1 developed mild incontinence. In conclusion, TURP appears to provide some benefit in selected patients with dementia and should not be considered to be a contraindication for such patients.

Aged↗
PubMed1999

[Detection of t(3 ; 21) (q26 ; q22) with AML1/EVI1 mRNA during progression of myelodysplastic syndrome to acute myeloid leukemia].

A 74-year-old woman had myelodysplastic syndrome (MDS) in 1986. In June 1994, she suffered exacerbation of pancytopenia with no chromosomal abnormalities, but AML1/EVI1 chimeric mRNA was detected by RT-PCR. Two months later, an increase in bone marrow blasts (5%) was noted, and chromosomal analysis detected t(3 ; 21) (q26 ; 22), del(7) (q22), del(11) (q23). In 1995, the marrow blasts increased to 30% and the patient died of disease progression. The AML1/EVI1 gene has been shown to cause blast crisis in chronic myelogenous leukemia. This case suggested that the AML1/EVI1 gene may be involved in the progression of MDS together with del(7) (q22) and del(11) (q23).

Acute Disease↗
PubMed1999

CD56+CD7+ stem cell leukemia/lymphoma with D2-Jdelta1 rearrangement.

OBJECT: We describe the characteristics of three patients with CD56+CD7+ stem cell leukemia/lymphoma. METHODS: These blasts were analyzed for morphologic, karyotypic, immunophenotypic, and immunogenotypic features using Southern blot and polymerase chain reaction analysis. MATERIALS: Peripheral blood, bone marrow aspirates, or biopsied mediastinal tumor specimens of three CD56+CD7+ stem cell leukemia/lymphoma patients were investigated. RESULTS: The bone marrow of all patients showed myeloperoxidase (MPO) negative blast cells with basophilic cytoplasm and distinct nucleoli with no azurophilic granules. The blasts of two patients were classified as acute lymphoblastic leukemia (L2). The liver, spleen, and lymph nodes were unaffected in all patients. All had an aggressive clinical course. The blasts were strongly positive for both CD7 and CD56 but negative for other T-lineage associated antigens, including CD1, CD2, surface membrane CD3, cytoplasmic CD3c (2/2), CD4, CD5 and CD8. The additional antigens were recognized as follows: CD19 (1/3 cases) as a B lineage, CD33 (1/3) as a myeloid marker, CD34 (2/3) as a stem cell, CD38 (1/1) and HLA-DR (2/3). When the patients relapsed, the phenotypes changed to blasts positive for CD5, CD10 and CD13 in patient 1, CD5 in patient 2, and CD33 in patient 3. MPO, however, remained negative. Cytogenetic analysis showed no common abnormal karyotype. All had a common D2-Jdelta1 induced by T-cell specific enhancer. Rearrangement of TCR beta and gamma genes occurred in patient 2, and IgH and TCR beta underwent rearrangement in patient 3. CONCLUSION: Although a more comprehensive case analysis is necessary, these data suggest the possibility that the blasts of the present cases come from a common lymphoid precursor (T, NK, and B cell) or from a NKT precursor as the fourth lymphoid lineage.

Acute Disease↗
PubMed1999

[Acute renal failure due to over-infusion in a child with bilateral obstruction of the pyeloureteral junction].

A 2-year-old boy was hospitalized with the chief complaint of oliguria and dyspnea. Bilateral hydronephrosis and obstruction of the pyeloureteral junction were detected by ultrasonography. Pulmonary edema was also found on chest radiographs. The clinical diagnosis was acute post renal failure due to bilateral pyeloureteral obstruction and pulmonary edema due to overtransfusion. After we performed bilateral percutaneous nephrostomy, the patient recovered from renal failure and pulmonary edema. Both nephrostomies were removed after we confirmed a non-obstructing pattern using the Whitaker test.

Acute Kidney Injury↗
PubMed1998

Immunological studies on the settlement-inducing protein complex (SIPC) of the barnacle Balanus amphitrite and its possible involvement in larva-larva interactions.

Immunological investigation has revealed that a settlement-inducing protein complex (SIPC), which induces cypris settlement of the barnacle Balanus amphitrite, is synthesized during larval development and accumulates in the cypris larva. We previously purified the SIPC from adult B. amphitrite, which was active when bound to a substratum. The SIPC is a glycoprotein of high molecular mass, consisting of three major subunits of 76, 88 and 98 kDa with lentil lectin (LCA)-binding sugar chains. In the present study, we prepared antiserum against each LCA-binding subunit of SIPC, and performed immunoblot analyses. Immunoblotting of adult extracts showed that anti-76-kDa antibody reacted only with the 76-kDa protein, whereas anti-88-kDa and anti-98-kDa antibodies reacted with both the 88-kDa and the 98-kDa proteins. Immunoblotting of larval extracts indicated that reactivity of the 76-kDa protein to anti-76-kDa antiserum increased during larval development and cyprid extracts reacted strongly. Moreover, by using immunostaining we found that the SIPC was contained in 'footprints' of cyprids, which have been shown to act as a settlement-inducing pheromone, and is secreted onto the antennular attachment discs. The results suggest that the SIPC (or SIPC-like proteins) is involved in both adult-larva and larva-larva interactions during settlement of the barnacle B. amphitrite.

Animals↗
PubMed1998

Mutagenic analysis of Vav reveals that an intact SH3 domain is required for transformation.

The vav proto-oncogene encodes a protein with multiple modulae domains that enable it to function as a mediator, linking tyrosine signaling to downstream events in hematopoietic cells. Circumstantial evidence suggests that protein-protein interactions exerted by two of these domains, the Src homology 2 (SH2) and the Src homology 3 (SH3), play an important role in the regulation of Vav activity. To study the relevance of the SH3 domain for the function of vav as a transforming gene, we have created several mutations in the SH3 domain located at its carboxy region. Substitution of the non-conserved aspartic acid 797 (to asparagine, D797N) retained the transforming potential of the vav oncogene, whereas substitutions of five highly conserved amino-acids: alanine 789 (to asparagine, A789N), leucine 801 (to arginine, L801R), tryptophan 821 (to arginine, W821R), glycine 830 (to valine, G830V) and valine 837 (to glutamic acid, V837E) greatly reduced its transforming potential. The mutant proteins resemble Vav in many biochemical properties; however, while the transforming mutant protein (D797N) associates with several unidentified proteins in a manner similar to that of Vav, the non-transforming mutant Vav proteins react very poorly with these proteins. Among the known Vav-interacting proteins, hnRNP-K associates with all mutant proteins except A789N and V837E whereas binding of Zyxin to any of the mutant proteins is not affected. Taken together, our results clearly demonstrate that the SH3 domain has a positive effect on vav activity and is needed for vav transformation. The vavSH3C associating protein(s) that are crucial for its activity as a transforming gene have probably not yet been identified.

3T3 Cells↗
PubMed1998

Effects of calmodulin inhibitors on cyprid larvae of the barnacle, Balanus amphitrite.

During our study on signal transduction systems involved in larval settlement and metamorphosis of the barnacle Balanus amphitrite, we could detect calmodulin, a major intracellular calcium-binding protein, in both cyprids and adult barnacles using immunoblot technique. In order to examine roles of calmodulin in larval settlement and metamorphosis, we examined the effects of calmodulin inhibitors involved in phosphodiesterase (PDE), myosin light chain kinase (MLCK), calmodulin kinase II (CaM-II) on cyprids. Calcium-calmodulin-dependent PDE inhibitors inhibited larval attachment and metamorphosis in a dose-dependent manner. In contrast, cyclic AMP (cAMP)-dependent PDE inhibitors promoted larval attachment and metamorphosis, while cyclic GMP (cGMP)-dependent PDE inhibitors did not show such effect. Thus, PDE activity may depend on cAMP rather than calmodulin or cGMP in promotion of larval attachment and metamorphosis. Moreover, calmodium inhibitors involved in MLCK or CaM-II inhibited larval behaviors for attachment and metamorphosis. These results suggest that calmodulin, which is present in both adult barnacles and cyprids, may be involved in enzyme reactions such as MLCK or CaM-II rather than PDE in B. amphitrite cyprids.

Animals↗
PubMed1998

Successful treatment of a patient with cardiac lymphoma who presented with a complete atrioventricular block.

A patient with primary cardiac lymphoma, which is very rare, generally is regarded to have a poor prognosis. We herein report a patient with cardiac lymphoma who was treated successfully by systemic chemotherapy and radiotherapy using a pacemaker to control the complete atrioventricular (A-V) block. A 70-year-old man had a syncope caused by a complete A-V block. An echocardiogram, a computed tomographic scan, and magnetic resonance imaging of his chest showed a cardiac tumor. At this time, a biopsy of the cardiac tumor disclosed malignant lymphoma (diffuse large cell type, B cell type). The patient was thus treated with systemic chemotherapy and radiotherapy and, as a result, achieved a complete remission with a disappearance of the A-V block. Recently, several successful outcomes involving primary cardiac lymphoma have been reported because of the progress in diagnostic techniques including echocardiography, computed tomographic scanning, and magnetic resonance imaging, as well as improvement in the therapy of malignant lymphoma. Our clinical experience indicated that an early and accurate diagnosis combined with the appropriate therapy can thus help in obtaining a long survival in patients with primary cardiac lymphoma.

Aged↗
PubMed1998

Spermatogonial stem cell transplantation, cryopreservation and culture.

Testis cells of a fertile male mouse can be transplanted to the seminiferous tubules of an infertile male, where the donor spermatogonial stem cells will establish spermatogenesis and produce spermatozoa that transmit the donor haplotype to progeny. In addition, stem cells can be cryopreserved for long periods, thereby making male germ lines immortal. Recently, mouse testis cells have been cultured for longer than 3 months and, following transplantation, produced spermatogenesis. These techniques are likely to be applicable to many species, since rat testis cells can be cryopreserved and generate spermatogenesis in the seminiferous tubules of immunodeficient mice.

Animals↗
PubMed1998

Culture of mouse spermatogonial stem cells.

Spermatogenesis occurs within the seminiferous tubules of mammals by a complex process that is highly organized, extremely efficient and very productive. At the foundation of this process is the spermatogonial stem cell that is capable of both self-renewal and production of progeny cells, which undergo differentiation over a period of weeks to months in order to generate mature spermatozoa. It had been thought that germ cells survive only a brief period in culture, generally less than a few weeks. However, an accurate assessment of the presence of spermatogonial stem cells in any cell population has only recently become possible with development of the spermatogonial transplantation technique. Using this technique, we have demonstrated that mouse spermatogonial stem cells can be maintained in culture for approximately 4 months and will generate spermatogenesis following transplantation to the seminiferous tubules of an appropriate recipient. Extensive areas of cultured donor cell-derived spermatogenesis are generated in the host, and production of mature spermatozoa occurs. Cultivation of the testis cells on STO feeders is beneficial to stem cell survival. These results provide the first step in establishing a system that will permit spermatogonial stem cells to be cultivated and their number increased in vitro to allow for genetic modification before transplantation to a recipient testis.

Animals↗
PubMed1998

H-7-induced apoptosis in the cells of a Drosophila neuronal cell line through affecting unidentified H-7-sensitive substance(s).

The present study was undertaken to reveal underlying mechanisms of apoptosis in neurons using clonal neuronal cells, ML-DmBG2-c2, derived from Drosophila larval central nervous system 1-(5-Isoquinolinesulfonyl)-2-methylpiperazine (H-7), a protein kinase inhibitor, induced cell death with typical features of apoptosis such as internucleosomal DNA fragmentation, nuclear condensation and apoptotic bodies in the cells. Though H-7 is known to inhibit cAMP-dependent protein kinase (PKA), protein kinase C (PKC), cGMP-dependent protein kinase (PKG), myosin light chain kinase (MLCK), and casein kinase I (CKI), specific inhibitors for these kinases such as H-89, calphostin C, ML-9, or CKI-7 did not induce apoptosis in the cells. Other kinases such as tyrosine kinase. PI3-kinase and Ca2+/CaM kinase II so far examined in the present study were interpreted not to be involved in the apoptotic cascade. Therefore, it is concluded that an H-7-sensitive substance(s) other than these kinases is responsible for the apoptosis in the neuronal cells. Caspase inhibitors prevented apoptosis in the cells treated with H-7. These results suggest that caspase(s) is involved downstream of the H-7-sensitive point in the cascade of the apoptosis.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1998

Spermatogonial transplantation and reconstitution of donor cell spermatogenesis in recipient mice.

Recently, we described a method to transplant testicular cells from a fertile donor mouse to the seminiferous tubules of an infertile recipient male, where the donor cells generate spermatogenesis. Spermatozoa produced by the transplanted cells in the recipient testis will fertilize eggs and transmit the donor haplotype to the resulting animals. In the most successful transplantations, up to 80 per cent of progeny sired by the recipient male arise from donor cell-derived spermatozoa. The cell responsible for generation of spermatogenesis following transplantation clearly is a spermatogonial stem cell, since the repopulation of recipient testes extends for periods exceeding 12 months. In the past year, experiments have shown that rat testicular cells transplanted to the seminiferous tubules of immunodeficient mice will generate rat spermatogenesis and produce normal appearing rat spermatozoa, opening the possibility of xenogeneic testicular cell transplantation for other species. In addition, it has proved possible to cryopreserve spermatogonial stem cells for long periods, following which they will produce normal spermatogenesis when transplanted to a recipient. The ability to cryopreserve testicular stem cells makes individual male germ lines immortal. In current work, we are focusing on techniques to increase the efficiency of spermatogonial transplantation and methods to culture the stem cells.

Animals↗
PubMed1998

Isolation of Aino virus from an aborted bovine fetus.

A male fetus of gestation day 187 was aborted from a Holstein-Friesian cow in an epizootic of the Aino virus (AINOV) in September 1995. Neutralizing antibody titers against AINOV were 1:128, 1:16 and 1:64 in the dam serum, fetal ascites and cerebrospinal fluid, respectively. A 10% brain suspension of the aborted fetus was prepared immediately after autopsy, rinsed three times and sonicated before centrifugation. The supernatant was then inoculated into HmLu-1 cell cultures. A cytopathic effect was noted on post-inoculation day 7. The isolated virus was identified as the AINOV based on the physicochemical properties and cross neutralization test. This is the first report on the isolation of AINOV from an aborted bovine fetus.

Abortion, Veterinary↗
PubMed1998

Whole-body vibration and health effects in the agricultural machinery drivers.

Recently farm mechanization has been widespread and developing rapidly, in particular riding farm machines are increasingly used in paddy fields in Japan. We have no information available on the actual situation regarding whole-body vibration on the seats of these farm machines from the standpoint of labour protection. Measurement and evaluation of whole-body vibration was performed on the seats of popular riding agricultural machineries. Whole-body vibration on the seats of combine harvesters and wheel tractors exceeded exposure limits and the fatigue-decreased proficiency boundary limit of 8 hr and also shortened the reduced comfort boundary limits of ISO 2631 (1985). Some combines, tractors and carieers had only less than one hour exposure duration as compared with the ISO 2631-1 standard (1997). On the other hand a questionnaire was also performed on the subject of agricultural machine operators. Any specific injury or other effects, i.e. low back injuries were not found among the group of operators as compared with those in non-operator farmers. It seems to be difficult to find out the health effects of whole-body vibration itself, because there may be a lot of causes, i.e. working posture, operating heavy materials, in farm working conditions.

Adult↗
PubMed1997

Cloning of Xenopus Dr1 (TBP-binding repressor) and its expression in oocytes and early embryos.

With a final goal to study how TBP-binding repressor Dr1 regulates transcription in Xenopus early embryos, we cloned its cDNA from Xenopus liver cDNA library. The cDNA was 1,986 bp long, with the open reading frame coding for 175 amino acids, whose sequence was highly homologous to its human counterpart. Xenopus Dr1 mRNA was expressed from the earliest stage of oogenesis, inherited as maternal mRNA at a high level, but its level became low at and after the neurula stage where RNA synthetic activity is strongly activated. Dr1 mRNA occurred in larger amounts in the animal half than in the vegetal half in 8-cell stage embryos, and in neurula and tailbud stage embryos its distribution was slightly larger in the anterior part than in the posterior part. These data show that Dr1 mRNA is expressed in a temporally and spatially regulated manner, and its occurrence at higher levels in earlier stage embryos may be responsible for their low transcriptional activity.

Amino Acid Sequence↗
PubMed1997

High affinity neurotensin receptor mRNA distribution in rat brain and peripheral tissues. Analysis by quantitative RT-PCR.

Neurotensin (NT) is widely distributed in the central nervous system (CNS) and peripheral tissues, and its actions are mediated by a specific family of G protein-coupled receptors. In this study, the authors have measured the levels of gene expression of the high-affinity neurotensin receptor (NTR) with quantitative reverse-transcriptase-polymerase chain reaction (RT-PCR). In the rat brain, the highest quantities of NTR mRNA were found in the ventral mesencephalon and in the hypothalamus. Surprisingly, almost identical quantities were detected in both structures, despite results from in situ hybridization studies revealing a low expression of NTR mRNA in the hypothalamus. The RT-PCR data suggest that large scale NTR mRNA synthesis is occurring in restrictive hypothalamic nuclei. Intermediate levels of expression were detected in the prefrontal cortex and striatum, and scant levels in the cerebellum. In peripheral tissues, the highest levels of NTR mRNA were detected in the colon, followed by the liver, and then duodenum and pancreas. In this study, the sensitivity and the accuracy of the quantitative RT-PCR method provided the means to estimate the relative distribution of NTR mRNA between brain structures and peripheral tissues. Therefore, this study promotes a better understanding of the localization of NTR synthesis in relationship with the various physiological effects of NT.

Animals↗