Biomedical subjects

I Nagano

Publications and source records attributed to I Nagano.

At least 73 records · Page 4Linked to original sources

PubMed2000

The genetic analysis of F1 hybrid larvae between female Trichinella spiralis and male Trichinella britovi.

Hybrids between female Trichinella spiralis and male Trichinella britovi were constructed. Then, hybrid genotype was characterized by DNA markers including mitochondrial cytochrome c oxidase subunit I (CO I) gene, the gene encoding the 43-kDa excretory-secretory (ES) protein, and genomic DNA fragments specific for T. spiralis and T. britovi identified from random amplified polymorphism DNA (RAPD). PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial CO I gene revealed that all hybrids carried a T. spiralis pattern. The same analysis of the gene encoding the 43-kDa ES protein showed that each hybrid carried both T. spiralis and T. britovi gene type simultaneously. In the analysis of genomic DNA using RAPD-derived PCR primers, some hybrids carried T. spiralis and T. britovi-specific RAPD markers, while others carried the RAPD marker of T. spiralis only.

Animals↗

PubMed2000

Five types of nuclei present in the capsule of Trichinella spiralis.

This study describes morphological changes during capsule formation of Trichinella spiralis with emphasis on nuclei within the capsule. The nuclei of the pre-existing muscle cell may become hypertrophied or degrade soon after the entrance of newborn larvae. Cytoplasm associated with these hypertrophied nuclei was basophilic in H&E staining and composed of mitochondria and rough endoplasmic reticulum. Satellite cells underwent cell division and joined to the nurse cell. These nuclei may also become hypertrophied or degrade. Cytoplasm associated with nuclei of satellite cell origin was eosinophilic in H&E staining and composed of mitochondria, polysomes, and smooth and rough endoplasmic reticulum. Eosinophilic cytoplasm (of satellite cell origin) became prevalent in the capsule as capsule formation proceeded. Infiltrated cells were observed within the capsule. Thus this study showed diversity of nuclei in the capsule of Trichinella.

Animals↗

PubMed2000

Genomic analysis of Blastocystis hominis strains isolated from two long-term health care facilities.

The genotype Blastocystis hominis is highly polymorphic. Therefore, a genetic marker would be a powerful tool for the identification or classification of B. hominis subtypes and could be used as a means to resolve the transmission route or origin of the parasite. To this end, 32 B. hominis isolates were collected from patients and/or staff members of two long-term health care facilities (facilities A and B), and these organisms were subjected to genotype analysis based on diagnostic PCR primers and restriction fragment length polymorphism (RFLP) of small subunit rRNA gene (rDNA). Based on PCR amplification using diagnostic primers which were developed from randomly amplified polymorphic DNA analysis of known strains of B. hominis, the 32 isolates of B. hominis were classified into three different subtypes. Thirty isolates, including twenty-four that were isolated from patients and a staff member, from facility A and all isolates isolated from six patients from facility B showed the same genotype. Two of six patients of facility B had been transferred from facility A, and these two patients also had the same-genotype B. hominis that corresponded to 24 isolates from facility A. This genotype strain may have been transmitted by these two patients from facility A to facility B, suggesting human-to-human transmission. In contrast, 2 of 26 isolates from facility A showed distinct genotypes, suggesting that the colonization by these two isolates is attributable to another infectious route. These different subtypes were subjected to RFLP analysis, and the RFLP profiles were correlated with the results obtained by diagnostic PCR primers. This study presents the first molecular evidence of possible human-to-human B. hominis infection between and/or among two small communities.

Animals↗

PubMed2000

Pulsatile flow enhances endothelium-derived nitric oxide release in the peripheral vasculature.

The effects of pulsatility in blood flow on endothelium-derived nitric oxide (EDNO) release in the peripheral vasculature were investigated. The basal and flow-stimulated EDNO release were compared between pulsatile and nonpulsatile systemic flows before and after the administration of NO synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA). Peripheral vascular resistance (PVR) was significantly lower in pulsatile flow than in nonpulsatile flow, but this difference disappeared after L-NMMA. The percent increase in PVR by L-NMMA was significantly larger in pulsatile flow. In reactive hyperemia in the hindlimb, the peak flow did not differ; however, both the repayment flow and the duration were significantly larger in pulsatile flow. Percent changes of these parameters by L-NMMA were significantly larger in pulsatile flow. These data indicated that pulsatility significantly enhances the basal and flow-stimulated EDNO release in the peripheral vasculature under in vivo conditions. We also studied the involvement of the Ca(2+)-dependent and Ca(2+)-independent pathways in flow-induced vasodilation using calmodulin inhibitor calmidazolium and tyrosine kinase inhibitor erbstatin A. PVR was significantly elevated by erbstatin A but not by calmidazolium, suggesting that flow-induced vasodilation was largely caused by tyrosine kinase inhibitor-sensitive activation of NO synthase.

Angiotensin II↗

PubMed2000

Significant gene expression of insulin-like growth factor II and proliferating cell nuclear antigen in a rapidly growing recurrent pituitary acth-secreting adenoma.

BACKGROUND: We quantified the expression of various growth-related factors in an adrenocorticotropic hormone (ACTH)-secreting adenoma that had recurred very rapidly as invasive macroadenoma. METHODS/RESULTS: A 43-year-old woman underwent successful transsphenoidal surgery for Cushing's disease. Seven years later, she was admitted to our ward for further endocrine examinations. In spite of a very high plasma ACTH level, the serum cortisol level was normal. Discrepancies between ACTH and cortisol levels were detected on the basis of diurnal rhythms, dexamethasone suppression tests, and corticotropin-releasing hormone test. The patient showed no clinical features of Cushing's disease. Magnetic resonance imaging of the pituitary showed an almost empty sella, and no microadenoma was found. These results, along with those of Sephadex column gel filtration and high-performance liquid chromatography of plasma-immunoreactive ACTH, suggested that the patient's residual corticotrophs secreted biologically inactive ACTH. Two years later, the patient suddenly developed diplopia and right abducens nerve palsy. She was slightly moonfaced and centrally obese. Her plasma ACTH and serum and urinary free cortisol levels were elevated, although discrepancies between ACTH and cortisol still existed. Magnetic resonance imaging revealed a large pituitary mass with suprasellar and cavernous sinus extensions. The tumor was excised, and the proopiomelanocortin gene and the expression of growth-related factors were analyzed. No mutations were found in the ACTH-coding region of the proopiomelanocortin gene. A significant expression of insulin-like growth factor II and proliferating cell nuclear antigen mRNAs was demonstrated. A high MIB-1 antibody labeling index was also detected in the adenoma tissue, suggesting high Ki-67 expression. CONCLUSION: These growth- and proliferation-related factors might be involved in the rapid growth and aggressiveness of this patient's pituitary adenoma.

Adenoma↗

PubMed1999

Identification of Trichinella isolates by polymerase chain reaction--restriction fragment length polymorphism of the mitochondrial cytochrome c-oxidase subunit I gene.

We developed a polymerase chain reaction based approach using restriction fragment length polymorphisms of the mitochondrial cytochrome c-oxidase subunit I to identify nine genotypes (Trichinella spiralis, Trichinella britovi-European strains, Trichinella britovi-Japanese strains, Trichinella nativa, Trichinella nelsoni, Trichinella T5, Trichinella T6, Trichinella T8 and Trichinella pseudospiralis) in the genus Trichinella. Partial mitochondrial cytochrome c-oxidase subunit I genes of nine genotypes were amplified by polymerase chain reaction, sequenced, and digested with three restriction endonucleases (Mse I, Alu I and Bsp1248 I). This polymerase chain reaction based restriction fragment length polymorphism method allowed the identification of Trichinella genotypes. Trichinella spiralis, Trichinella britovi-Japanese strains, Trichinella nelsoni, T5 and Trichinella pseudospiralis were distinguishable by digestion with Mse I. Trichinella britovi-European strains and Trichinella T8 were distinguishable by digestion using Alu I, and Trichinella nativa and Trichinella T6 were distinguishable by double-digestion with Mse I and Bsp1286 I. The results obtained with this polymerase chain reaction based restriction fragment length polymorphism assay confirmed those previously reported by others and support the separation of the Japanese isolates as a new genotype, namely Trichinella T9.

Animals↗

PubMed1999

Exposure with the environmental estrogen bisphenol A disrupts the male reproductive tract in young mice.

Environmental estrogens (endocrine disruptive chemicals) have been shown to affect reproduction in wild life and it has been reported that maternal exposure with those chemicals have adverse effects on the male reproductive tract. However, little is known about the potential effects of prepubertal or pubertal exposure with environmental estrogens on the male reproductive tract. Here we examine plasma hormone levels and histology in the testis of mice following either 4- or 8-week oral administration of bisphenol A. Plasma free testosterone levels were dramatically decreased following 8 weeks of bisphenol A treatment compared with control group and morphologically multinucleated giant cells having greater than three nuclei were found in seminiferous tubules in the testis following the 8-week bisphenol A treatment. No differences in plasma corticosterone and luteinizing hormone levels were seen between bisphenol A and control groups. Thus, exposure with bisphenol A around pubertal period may directly disrupt the male reproductive tract. These facts suggest that more detailed studies will warrant the assessment of the risk to the developing human testis from exposure to bisphenol A and other environmental estrogens in prepubertal and pubertal period.

Administration, Oral↗

PubMed1999

Antifibrinolytic therapy with tranexamic acid in cardiac operations.

To demonstrate its antifibrinolytic effects and establish an effective regimen of tranexamic acid for hemostasis, the authors measured alpha2-plasmin inhibitor-plasmin complexes, thrombin-antithrombin III complexes and postoperative blood loss in three groups undergoing different regimens during cardiac operations. Forty-six patients undergoing coronary artery bypass grafting or valve replacement were enrolled in this study. They were divided into three groups of drug administration. A bolus infusion of 50 mg/kg tranexamic acid was given to 17 patients at the end of cardiopulmonary bypass (control group) and to 14 patients at the beginning of cardiopulmonary bypass (group A). In addition to the same bolus infusion at the beginning of cardiopulmonary bypass as group A, a continuous infusion of 10 mg/kg per h, starting at the time of skin incision and maintained for 6 h after cardiopulmonary bypass was given to 15 patients (group B). The marked increase in alpha2-plasmin inhibitor-plasmin complexes at the end of cardiopulmonary bypass in the control group was significantly reduced in group A (P < 0.01) and a further reduction was observed in group B (P < 0.001). The difference in postoperative blood loss only reached significant levels between the control group and group B (P < 0.05). Although a significant increase in thrombin-antithrombin III complexes during cardiopulmonary bypass was similarly observed in all groups, no thromboembolic events occurred in any group, nor was any difference seen in graft patency. From the tranexamic acid therapy regimens tested in this study, a continuous infusion of 10 mg/kg per h starting at the time of skin incision to 6 h after cardiopulmonary bypass, with a bolus infusion of 50 mg/kg at the beginning of cardiopulmonary bypass, proved to be the most effective.

Aged↗

PubMed1999

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the identification of Trichinella isolates.

In the present study, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was developed to identify 5 species (Trichinella spiralis, Trichinella britovi, Trichinella nativa, Trichinella nelsoni and Trichinella pseudospiralis) and 3 phenotypes of uncertain taxonomic status (Trichinella T5, T6, and T8). Eleven restriction endonucleases were used to restrict 3 DNA fragments (1) a 2800 bp fragment of the 43 kDa excretory-secretory (E-S) protein gene, (2) a 1250 bp fragment amplified with the primer pair SB147A and (3) a 372 bp fragment amplified with the primer pair SB372A. This RFLP method allows the identification of the 8 Trichinella phenotypes as follows: T. spiralis by the HinfI or DdeI endonuclease restriction of the 2800 bp fragment; T. nativa by the RsaI restriction of the 2800 bp fragment, or by the AluI restriction of the 1250 bp fragment; T. britovi and Trichinella T8 by the AluI restriction of the 1250 bp fragments, and can be discriminated between them by the SspI restriction of the 2800 bp fragment; T. pseudospiralis by the MspI restriction of the 372 bp fragment; T. nelsoni by the HhaI or AluI restriction of the 2800 bp fragment; Trichinella T5 by the HhaI restriction of the 2800 bp fragment; Trichinella T6 by the AluI restriction of the 1250 bp fragment; and Trichinella T8 by the SspI or RsaI restriction of the 2800 bp fragment. This study reveals also an intraspecifies polymorphism in the 2800 bp and 1250 bp fragments for T. britovi, Trichinella T5 and T6.

Animals↗

PubMed1999

A panel of antigens of muscle larvae of Trichinella spiralis and T. pseudospiralis as revealed by two-dimensional western blot and immunoelectron microscopy.

This study characterized antigens of Trichinella spiralis and T. pseudospiralis muscle larvae recognized by mice infected with the worms. Two-dimensional (2-D) Western blot analysis revealed some profile of antigenic peptides including: (1) molecular weight (MW); (2) isoelectric points (pI), (3) reactivity to well-defined monoclonal antibodies (mAb) and (4) cross-reactivity between the 2 species. Antigenic peptides of T. spiralis consisted of about 100 spots. The MW ranged from 22 to 80 kDa, and pI ranged from 4 to 7. The mAb against TSL-1 stained most of the T. spiralis excretory-secretory (E-S) peptides migrating at 40, 45 and 50 kDa, and the mAb against TSL-4 stained non-E-S peptides. Antigenic peptides of T. pseudospiralis consisted of about 20 to 30 peptide spots. The MW ranged from 25 to 80 kDa, and pI ranged from 4 to 7. The mAb against TSL-1 stained most of the T. pseudospiralis E-S peptides migrating at 35 and 45 kDa, and the mAb against TSL-4 stained non-E-S peptides. Two-dimensional Western blots showed that the E-S products of T. spiralis and T. pseudospiralis were highly cross-reactive with each other. The non-E-S peptides were, however, not recognized by T. pseudospiralis-infected sera but were recognized by T. spiralis-infected sera. An immunoelectron microscopical study showed the similar result that stichocyte granules and cuticle surface (known to contain E-S antigen) had cross-reactive antigens between the two species. T. pseudospiralis-infected sera stained very weakly the cuticle inner layers and haemolymph (known to contain non-E-S antigen). This evidence implies that mice infected with T. pseudospiralis do not evoke antibodies against non-E-S antigen at the detectable level.

Animals↗

PubMed1999

Pituitary adenoma showing intermittent secretion of high molecular weight adrenocorticotropin without evidence of Cushing's disease.

A 29-year-old woman was admitted in March 1998 due to high plasma ACTH levels, amenorrhea and uncontrolled diabetes mellitus (DM) which had persisted since 1991. Plasma ACTH levels showed a wide range of changes: they were usually high (59-240 pg/ml), intermittently very high (336-942 pg/ml), and sometimes normal or low. Plasma cortisol levels were usually normal but were sometimes high when the ACTH levels were very high. However, even when the plasma ACTH levels were very high, she did not show any cushingoid features. DM was diagnosed as non-insulin-dependent DM. Plasma ACTH showed an excessive response to CRH, while cortisol showed a delayed response. Plasma cortisol showed a poor response to ACTH-(1-24). ACTH receptor gene analysis revealed no mutations in the ACTH receptor-coding region. MRI showed a nonenhancing mass on the left side of the pituitary. Cavernous sinus sampling showed a very high plasma ACTH level in the left cavernous sinus compared with the levels in the right cavernous sinus and peripheral blood. Sephadex G-75 gel filtration of plasma ACTH immunoreactivity in plasma obtained by cavernous sinus sampling showed mainly high molecular forms of ACTH, probably proopiomelanocortin and ACTH-beta-lipotropin. This case is a very rare form of pituitary adenoma showing intermittent secretion of high molecular ACTH unaccompanied by cushingoid features.

Adenoma↗

PubMed1999

Ischemic heart attacks following cessation of aspirin before coronary artery bypass surgery: A report of two cases.

We present herein two patients who suffered life-threatening ischemic heart attacks following the preoperative discontinuation of aspirin. Since their cardiac conditions were stable in the long-term while under medication, the cessation of aspirin was highly suspected to have caused or at least to have contributed to their ischemic events. We thus discuss the appropriate timing for discontinuation of aspirin before surgery in patients with ischemic heart disease.

Aged↗

PubMed1998

Morphometric analysis of the peripheral neuropathy of AIDS.

A morphometric study of the peripheral nervous system at autopsy was undertaken in 11 AIDS patients and 10 controls. The left L4, L5, and S1 dorsal root ganglia (DRG) and samples of the sciatic nerve at the buttock, tibial nerve at the knee, and sural nerve at the ankle were collected. Indices of neuronal/axonal degeneration and of segmental demyelination/ remyelination were measured at each level. The small number of cases and evidence of neuropathy in a number of the control cases resulted in statistical significance for only a limited number of comparisons. Nodules of Nageotte in the DRG were increased fivefold in AIDS cases compared with controls, and axonal degeneration in single-teased nerve fibers was increased 9-fold in the sciatic nerve, 28-fold in the tibial nerve, and 12-fold in the sural nerve. The ratios of AIDS to controls for the density of remaining DRG neurons and large myelinated axons were reduced to 0.71 in the DRG, 0.84 in the sciatic nerve, 0.84 in the tibial nerve, and 0.66 in the sural nerve. Axonal regeneration in single-teased nerve fibers was increased threefold at the sciatic nerve level in AIDS, but was markedly reduced at distal levels. Acute segmental demyelination in single-teased nerve fibers was present to a greater extent than in controls at all levels of the peripheral nerves in the AIDS cases. Remyelinating fibers were increased compared with controls only in the proximal sciatic nerve. No case showed the changes of cytomegalovirus infection. In a parallel immunohistochemical study of these AIDS peripheral nerves, T-cell and macrophage infiltration, with cytokine expression, was demonstrated. The pathological process in the neuropathy of terminal AIDS appears to be a multifocal immunologically mediated inflammatory disease, with increased density of macrophages and T cells at all levels of the peripheral nervous system, producing segmental demyelination and axonal degeneration. Reparative processes (axonal regeneration and remyelination) occurred only at the most proximal levels of the nerves.

Acquired Immunodeficiency Syndrome↗

PubMed1998

Genomic polymorphism among Blastocystis hominis strains and development of subtype-specific diagnostic primers.

Genomic polymorphisms among nine strains of Blastocystis hominis were examined by random amplified polymorphic DNA (RAPD) using four different arbitrary polymerase chain reaction (PCR) primers. Based on the RAPD patterns, nine strains were classified into three groups. The specific primers designed from the unique bands yielded a single band from within each same group, but did not amplify between all the groups examined. Specificity of these diagnostic primers was tested against several common intestinal parasites and a yeast, and no amplification was confirmed. Since the current criteria indicates that Blastocystis organisms isolated from humans are designated as B. hominis, the authors propose to classify several subtypes among B. hominis groups based on the difference of genomic DNA using three diagnostic primers.

Animals↗

PubMed1998

Differences and similarities between Trichinella spiralis and T. pseudospiralis in morphology of stichocyte granules, peptide maps of excretory and secretory (E-S) products and messenger RNA of stichosomal glycoproteins.

The ultrastructure of muscle larvae of Trichinella pseudospiralis was studied by electron microscopy. The overall structure of muscle larvae of T. pseudospiralis resembled that of T. spiralis except for the stichocyte granules. T. pseudospiralis had at least 3 kinds of stichocyte granules distinguishable from each other by their shape, size and inclusions. The granules had some resemblance to alpha granules or beta granules of T. spiralis, but no resemblance to gamma granules. In favour of these morphological differences and similarities among T. spiralis and T. pseudospiralis, excretory and secretory (E-S) products (originating from stichocyte granules) of the 2 species differed to some degree. In an analysis by 2-dimensional electrophoresis, some peptide spots migrating at 45 kDa were shared by the 2 species but the other spots were unique to each of the 2 species. Messenger RNA encoding the 43 kDa glycoprotein of stichocyte granules was detected in the muscle larvae of both species but mRNA encoding the 53 kDa glycoprotein was detected only in muscle larvae of T. spiralis.

Animals↗

PubMed1998

The detection of Trichinella with polymerase chain reaction (PCR) primers constructed using sequences of random amplified polymorphic DNA (RAPD) or sequences of complementary DNA encoding excretory-secretory (E-S) glycoproteins.

Diagnostic PCR primers for Trichinella were constructed. Twelve pairs of primers were designed based on the sequences of random amplified polymorphic DNA, and 4 pairs of primers were designed based on the reported sequences of complementary DNA encoding excretory-secretory glycoproteins. With these primers, 31 samples of DNA from different strains of Trichinella including 5 species (Trichinella spiralis, Trichinella britovi, Trichinella nativa, Trichinella nelsoni and Trichinella pseudospiralis) and 3 phenotypes of uncertain taxonomic level (Trichinella T5, T6 and T8) were tested with PCR. Genus Trichinella can be identified by 4 different primer pairs (SB147D, SB372A, SB153, or Ts43). Trichinella spiralis can be identified by the presence of a 673 bp amplicon in PCR with the primer pair SB147B. Trichinella nelsoni can be identified using primer pair SB147F or by the presence of 673 bp and ca. 380 bp amplicon in PCR with the primer pair SB147B. Trichinella pseudospiralis can be identified by 2 primer pairs (SB147E or SB372B). Trichinella T5 can be identified by the primer pair SB147G. Trichinella T8 can be identified by its positivity by the primer pair SB147C and its negativity by the primer pair SB372C. A group of Trichinella species (T. britovi, T. nativa and Trichinella T6) can be identified by the primer pair SB372C.

Animals↗

PubMed1998

Detection of verotoxin-producing Escherichia coli O157:H7 by multiplex polymerase chain reaction.

We constructed primers for multiplex polymerase chain reaction (PCR) to detect verotoxin-producing Escherichia coli (VTEC) O157:H7. The multiplex PCR primers were designed from the sequence of the flagellin structural gene of Escherichia coli flagellar type H7 (GenBank under accession number L07388), and from the sequence of the rfbE gene of Escherichia coli O157:H7 (GenBank under accession number S83460). In addition to these primers, we used a primer pair reported by Karch and Meyer (J. Clin. Microbiol. 27: 2751-2757, 1989) to amplify various VT genes from VTEC. All of the examined specimens (18 isolates) of VT-producing E. coli O157:H7 showed a positive result by the multiplex PCR test with the three sets of primers. The sensitivity of detection for VT-producing E. coli O157:H7 was shown to be at least 3,000 cells per PCR tube.

Animals↗

PubMed1997

CMO I deficiency caused by a point mutation in exon 8 of the human CYP11B2 gene encoding steroid 18-hydroxylase (P450C18).

Corticosterone methyloxidase I (CMO I) deficiency is an autosomal recessive disorder of aldosterone biosynthesis. To determine further the molecular genetic basis of CMO I deficiency, a patient of Turkish origin that suffered from CMO I deficiency was studied. Nucleotide sequencing of the PCR-amplified exons from the genomic DNA of this patient revealed a single point mutation CTG (leucine) CCG (proline) at codon 461 in exon 8 of CYP11B2, which is involved in the putative heme binding site of steroid 18-hydroxylase (P450(C18)). The expression study using a cDNA introducing the point mutation revealed that the amino acid substitution totally abolishes the P450(C18)p3 enzyme activities required for conversion of 11-deoxycorticosterone to aldosterone, even though the mutant product was detected in the mitochondrial fraction of the transfected cells. These results suggest that this point mutation causes CMO I deficiency.

Aldosterone↗