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Biomedical subjects

T Toyoda

Publications and source records attributed to T Toyoda.

At least 19 recordsLinked to original sources
PubMed2006

Cerebellar hypoplasia associated with an avian leukosis virus inducing fowl glioma.

Fowl glioma-inducing virus (FGV), which belongs to subgroup A of avian leukosis virus (ALV), shows tumorigenicity and pathogenicity, mainly in the nervous system, and causes astrocytoma and perineurioma. Apart from these neoplasms, cerebellar anomaly was found in chickens infected with FGV in ovo. The study reported here describes the morphologic characteristics of the affected cerebellum. Specific-pathogen-free chickens (C/O) were inoculated with FGV through the yolk sac on the 7th day of incubation. The cerebellar anomaly included diffuse depletion of granular cells of the internal granular layer (IGL), remnants of the external granular layer (EGL), and disorganization of the Purkinje cell layer. These cerebellar changes were observed in all birds except one. In the infected embryos, the EGL was thicker and had an irregular arrangement with a thin molecular layer (ML) and IGL, compared with the control. The granular cells were immunohistochemically positive for ALV common antigen. Immunohistochemical analysis for vimentin revealed disarrangement and decreased number of Bergmann's fibers. Use of the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling method and electron microscopy indicated that apoptotic granular cells were frequently observed in the EGL and ML. These results suggested that the cerebellar anomaly was hypoplasia, principally resulting from the apoptosis of granular cells in the EGL and ML caused by FGV infection and that the cell loss induced obstruction of granular cell migration and disarrangement of Bergmann's fibers in the ML.

Animals↗
PubMed2005

Mechanical compression and hydrostatic pressure induce reversible changes in actin cytoskeletal organisation in chondrocytes in agarose.

In numerous cell types, the cytoskeleton has been widely implicated in mechanotransduction pathways involving stretch-activated ion channels, integrins and deformation of intracellular organelles. Studies have also demonstrated that the cytoskeleton can undergo remodelling in response to mechanical stimuli such as tensile strain or fluid flow. In articular chondrocytes, the mechanotransduction pathways are complex, inter-related and as yet, poorly understood. Furthermore, little is known of how the chondrocyte cytoskeleton responds to physiological mechanical loading. This study utilises the well-characterised chondrocyte-agarose model and an established confocal image-analysis technique to demonstrate that both static and cyclic, compressive strain and hydrostatic pressure all induce remodelling of actin microfilaments. This remodelling was characterised by a change from a uniform to a more punctate distribution of cortical actin around the cell periphery. For some loading regimes, this remodelling was reversed over a subsequent 1h unloaded period. This reversible remodelling of actin cytoskeleton may therefore represent a mechanism through which the chondrocyte alters its mechanical properties and mechanosensitivity in response to physiological mechanical loading.

Actin Cytoskeleton↗
PubMed2005

Nested polymerase chain reaction for detection of the avian leukosis virus causing so-called fowl glioma.

The complete nucleotide sequence of the avian leukosis virus causing so-called fowl glioma has been previously determined. Primers were designed for detection of the fowl glioma-causal virus (FGV) based on the 3' untranslated region of the viral genome. The provirus and viral RNA of FGV were specifically detected in various organs and tissues, including feather pulp, from experimentally infected birds using nested polymerase chain reaction (PCR) and reverse transcription nested PCR. The prevalence of FGV was evaluated in 131 Japanese fowls of a zoological garden in Japan based on the detection of the FGV genome in feather pulp using PCR and the detection of viral antigen in faeces by enzyme-linked immunosorbent assay. FGV proviral DNA was detected in feather pulp of 52 birds (39.7%) by nested PCR. Later, nine dead birds from among the 52 were histologically diagnosed as having fowl glioma and found to have the proviral DNA in the affected brain. These results demonstrated that the PCR-based detection of FGV in feather pulp is useful for epidemiological studies on fowl glioma.

Animals↗
PubMed2005

Multiple perineuriomas in chicken (Gallus gallus domesticus).

Intraneural perineurioma is an extremely rare condition characterized by perineurial cell proliferation within peripheral nerve (PN) sheaths. In the veterinary field, this entity has been reported only in a dog. We examined multiple enlargements of PNs in 11 chickens (Gallus gallus domesticus) (9 Japanese bantams and 2 specific pathogen-free White Leghorn), which were inoculated with an avian leukosis virus (ALV) causing so-called fowl glioma. All chickens clinically exhibited progressive leg paralysis. Lumbosacral plexus, brachial plexus, and/or spinal ganglion were commonly affected, and these nerves contained a diffuse proliferation of spindle cells arranged concentrically in characteristic onion bulb-like structures surrounded by residual axons and myelin sheaths. The spindle cells were immunohistochemically negative for S-100alpha/beta protein. Electron microscopy revealed that these cells were characterized by short bipolar cytoplasmic processes, occasional cytoplasmic pinocytotic vesicles, and discontinuous basal laminae. These features are consistent with those of intraneural perineurioma. Furthermore, the specific sequence of the ALV was detected in the PN lesions of 8/11 (73%) birds by polymerase chain reaction. These results indicate that the multiple intraneural perineuriomas of chicken may be associated with the ALV-A causing fowl glioma.

Animals↗
PubMed2004

In vitro release of Tacrolimus from Tacrolimus ointment and its speculated mechanism.

The in vitro release profiles and the bleeding phenomenon of Tacrolimus and propylene carbonate (PC) as a dispersing solvent for Tacrolimus drug substance in Tacrolimus ointment were investigated when changing concentrations of Tacrolimus and PC in the ointment were used, respectively. The bleeding test result indicated that Tacrolimus was in equilibrium between inside and outside of PC droplets in intact ointment base. A cumulative release amount of Tacrolimus from ointment, plotted against the square root of time, showed a straight line initially with a slope of q1 followed to change a slope to be q2 at a certain time, where the relation of these slopes being q1<q2. The q1 values increased with the concentration of Tacrolimus but decreased with PC concentration in Tacrolimus ointment. And the q2 values increased with Tacrolimus concentration but were independent of PC concentration. These profiles indicated that there were two phases for Tacrolimus release from ointment, namely, first phase was related with the period during PC release and the second phase was related with the state of ointment after PC release. When the PC release was applied to the Higuchi's release equation, the above slope q1 was found to be correlated to the parameter of A/phi(0), where A was a parameter of release rate of PC and phi(0) was an initial volume fraction of PC droplets. It should be indicated that more rapid release rate of PC rather than that of Tacrolimus resulted in the generation of amorphous phase of Tacrolimus outside of remaining PC droplets. During PC release, the slope q1 could be influenced by the thermodynamic activity of Tacrolimus dissolved in PC droplets. After PC release, it would be reasonable to speculate that the amorphous cluster of Tacrolimus with a constant thermodynamic activity would give constant q2 values regardless of PC contents in Tacrolimus ointment.

Chemistry, Pharmaceutical↗
PubMed2004

Do olfactory reference syndrome and jiko-shu-kyofu (a subtype of taijin-kyofu) share a common entity?

OBJECTIVE: Olfactory reference syndrome (ORS) in the Western literature is characterized as preoccupation with the idea that the body emits a foul odor. Japanese patients with a feature similar to ORS have long been recognized as jiko-shu-kyofu, which is believed to be a culture-bound syndrome and specific to Japan. The aim of the study was to clarify the relationship between the two separate syndromes that had independently been recognized in culturally different settings. METHOD: The phenomenology and treatment of seven patients with jiko-shu-kyofu were described. A feature of jiko-shu-kyofu was then compared with that of ORS. RESULTS: In our cases, clinical characteristics of jiko-shu-kyofu such as symptomatology, insight, and pharmacotherapy response were found identical to those of ORS except for the onset at relatively younger ages. CONCLUSION: Jiko-shu-kyofu and ORS may share a common clinical entity, hence the former is not a culturally distinctive disorder.

Adolescent↗
PubMed2004

Nutritional secondary hyperparathyroidism and osteodystrophia fibrosa in a Hodgson's hawk-eagle (Spizaetus nipalensis).

A Hodgson's hawk-eagle (Spizaetus nipalensis) reared by a falconer showed severe weakness with multiple fractures of bone. It had a history of being fed an all-meat diet. Serological examination revealed a hypocalcaemia (72.0 microg/ml), and hypophosphataemia (29.0 microg/ml). Gross and microscopic examinations demonstrated severe osteodystrophia fibrosa (fibrous osteodystrophy) characterized by osteoclastic bone resorption and intertrabecular fibrosis with unmineralized trabecular bone containing a large amount of unmineralized osteoid. There was also hypertrophy and hyperplasia of the parathyroid glands, which is consistent with nutritional secondary hyperparathyroidism.

Animal Feed↗
PubMed2004

Genome sequence analysis of the avian retrovirus causing so-called fowl glioma and the promoter activity of the long terminal repeat.

So-called fowl glioma is a retroviral infectious disease caused by avian leukosis virus subgroup A (ALV-A). We determined the complete nucleotide sequence of the virus genome. The full-length sequence was consistent with a genetic organization typical of a replication-competent type C retrovirus lacking viral oncogenes. The coding sequences were well conserved with those of replication-competent viruses, but the 3' noncoding regions including LTR were most related to those of replication-defective sarcoma viruses. The U3 region of the LTR had a few deletions and several point mutations compared to that of other ALVs. The promoter activities of the LTRs of glioma-inducing ALV and ALV-A standard strain, RAV-1, were equivalent in chick embryo fibroblasts (CEF), while that of glioma-inducing ALV was significantly lower than that of RAV-1 in human astrocytic cells. These subtle differences of the promoter activity of the LTR may be related to the induction of glial neoplasm.

Alpharetrovirus↗
PubMed2003

Ser624 of the PA subunit of influenza A virus is not essential for viral growth in cells and mice, but required for the maximal viral growth.

Serine at position 624 of PA subunit of the Influenza A virus RNA polymerase is the active site of a serine protease domain. To examine the role of this protease activity in the viral infection cycle, we compared the growth and the pathogenesis of influenza A/WSN/33 (WSN) and the virus encoding a PA with a S624A mutation (S624A virus), which were generated by the plasmid-based rescue system. The growth of S624A virus was less extensive than that of WSN in cells. The LD50 of S624A virus and WSN for intranasal infection in Balb/C mice was 4.0 x 10(4) and 9.3 x 10(3) PFU, respectively. That for intracranial infection was 460 and 200 PFU, respectively. These data indicated that Ser624, the active site of the serine protease activity of PA, is not essential for viral growth and pathogenesis, but is required for the maximal viral growth.

Animals↗
PubMed2001

Effect of diazepam binding inhibitor (DBI) on the fluid intake, preference and the taste reactivity in mice.

We have reported that a diazepam binding inhibitor (DBI)-like peptide is released by the aversive quinine stimuli 'Chem. Senses 25 (2000) 739'. To determine the effect of DBI on the fluid intake, we injected a DBI peptide fragment into the fourth ventricle in mice. DBI suppressed the intake of 5% sucrose, water and 0.9 mM quinine-HCl and the preference for 0.05% saccharin. Administration (i.p.) of flumazenil, a benzodiazepine receptor antagonist, 20 min before the injection of DBI (i.c.v.) antagonized the suppressive effect of DBI on the intake and the preference for saccharin. We also studied the dose dependency of the effect of DBI on the intake of 5% sucrose. Injection of DBI in excess of 3 microg suppressed the intake of 5% sucrose in mice. Furthermore, injection of DBI (i.c.v.) increased the aversive response to 0.9% NaCl in the taste reactivity in mice. These results suggest that DBI affect the preference to food.

Animals↗
PubMed2001

Cerebral aneurysms in the perforating artery manifesting intracerebral and subarachnoid haemorrhage--report of two cases.

BACKGROUND: An arteriosclerotic aneurysm in the perforating artery has been focused on as a causative factor for hypertensive intracerebral haemorrhage. However, its pathogenesis remains unknown, and its existence is still a controversy. CASE DESCRIPTION: A 62-year-old female and a 70-year-old male with a history of hypertension suffered from intracerebral haemorrhage accompanied by subarachnoid haemorrhage. Cerebral angiograms demonstrated an aneurysm arising from the perforating artery at the central location of the haematoma in both cases. The aneurysms were confirmed as the cause of bleeding during microsurgery, and were resected. Histological examination of the surgical specimens revealed that the walls of the aneurysms lacked internal elastic lamina and consisted only of the adventitia. CONCLUSION: These findings demonstrate that the aneurysm in the perforating artery can be a causative factor for hypertensive intracerebral haemorrhage, and indicate that the loss of internal elastic lamina induced by hypertension may contribute to the formation of the aneurysm of the perforating artery.

Aged↗
PubMed2001

Influenza virus RNA polymerase PA subunit is a novel serine protease with Ser624 at the active site.

BACKGROUND: Influenza virus RNA polymerase is a multifunctional enzyme that catalyses both transcription and replication of the RNA genome. The function of the influenza virus RNA polymerase PA subunit in viral replication is poorly understood, although the enzyme is known to be required for cRNA --> vRNA synthesis. The protease related activity of PA has been discussed ever since protease-inducing activity was demonstrated in transfection experiments. RESULTS: PA protein was highly purified from insect cells infected with the recombinant baculovirus carrying PA cDNA, and a novel chymotrypsin-type serine protease activity was identified with the synthetic peptide, Suc-LLVY-MCA, in the PA protein. [3H]DFP was crosslinked with PA and a mutational analysis revealed that serine624 was as an active site for the protease activity. CONCLUSIONS: These results constitute the demonstration of protease activity in PA subunit of the influenza virus RNA polymerase complexes.

Amino Acid Sequence↗
PubMed2001

Doppler sonography of the deep lingual artery.

PURPOSE: To clarify the Doppler sonographic features of the lingual artery in normal subjects and to evaluate those of patients with cancer of the tongue. MATERIAL AND METHODS: Sixty-seven volunteers and 12 patients with cancer and/or leukoplakia of the tongue were examined with an intraoral sonographic probe. The visibility of the deep lingual artery was determined on transverse and anteroposterior images. On the transverse images, the vascular index, which was defined as the number of colored pixels, was measured on bilateral lingual arteries. Thereafter, the degree of symmetry was evaluated for normal subjects and patients. RESULTS: In normal subjects, between younger and older volunteers, there were no significant differences in visibility of the trunk but differences were found between the two groups for the dorsal branches. The vascular indices of the right and left sides were not different. The characteristic Doppler sonographic feature was vasculature in and around the tumors in the patients with cancer of the tongue. The symmetry indices of the cancer patients were significantly different from those of normal subjects. CONCLUSION: Doppler sonography should be an important procedure for evaluation of tongue neoplasms.

Adult↗
PubMed2001

Molecular evolution of human echovirus 9 isolated from patients with aseptic meningitis in northern Kyushu during the summer of 1997.

An epidemic of aseptic meningitis caused by human echovirus 9 (E-9) occurred in the summer of 1997 in northern Kyushu, Japan. Sequences of genome position 2504-3358, which encoded a part of VP1, of the nine isolated viruses were determined. An RGD motif and B-C loop were found in all. They were almost identical and closely related to the virulent strain Barty.

Amino Acid Sequence↗
PubMed2001

Clinical evaluation of anti-tuberculous glycolipid immunoglobulin G antibody assay for rapid serodiagnosis of pulmonary tuberculosis.

Previously we reported the development of a highly sensitive enzyme-linked immunosorbent assay specific for anti-tuberculous glycolipid (anti-TBGL) for the rapid serodiagnosis of tuberculosis. In this study, the usefulness of an anti-TBGL antibody assay kit for rapid serodiagnosis was evaluated in a controlled multicenter study. Antibody titers in sera from 318 patients with active pulmonary tuberculosis (216 positive for Mycobacterium tuberculosis in smear and/or culture tests and 102 smear and culture negative and clinically diagnosed), 58 patients with old tuberculosis, 177 patients with other respiratory diseases, 156 patients with nonrespiratory diseases, and 454 healthy subjects were examined. Sera from 256 younger healthy subjects from among the 454 healthy subjects were examined as a control. When the cutoff point of anti-TBGL antibody titer was determined as 2.0 U/ml, the sensitivity for active tuberculosis patients was 81.1% and the specificity was 95.7%. Sensitivity in patients with smear-negative and culture-negative active pulmonary tuberculosis was 73.5%. Even in patients with noncavitary minimally advanced lesions, the positivity rate (60.0%) and the antibody titer (4.6 +/- 9.4 U/ml) were significantly higher than those in the healthy group. These results indicate that this assay using anti-TBGL antibody is useful for the rapid serodiagnosis of active pulmonary tuberculosis.

Antibodies, Bacterial↗