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Biomedical subjects

M Asahina

Publications and source records attributed to M Asahina.

At least 19 recordsLinked to original sources
PubMed1999

Hemorrhagic enteritis associated with Clostridium perfringens type A in a dog.

A female Shetland sheep dog died suddenly with hemorrhagic diarrhea and vomitting, and was examined pathologically and microbiologically. Gross pathological change was restricted to the intestinal tract. The intestine contained watery, blood-stained fluid. Histopathologically, the principal intestinal lesion was superficial mucosal hemorrhagic necrosis at the jejunoileum. Many Gram-positive bacilli were found adhering to the necrotic mucosal surface in parts of the intestinal tract. Clostridium perfringens in pure culture were isolated from jejunal contents by anaerobic culture. These results suggested that the typical lesion of this case coincided with canine hemorrhagic enteritis and enterotoxemia due to C. perfringens infection could be the cause of sudden death.

Acute Disease↗
PubMed1998

Demyelinating polyneuropathy with preferentially-proximal involvement.

A 47-year-old man showed progressive, symmetrical weakness in the limbs for 6 months. There was muscle atrophy, fasciculations, and acute denervation without motor conduction abnormalities below the elbows or knees, and motor neuron disease had once been suspected. However, compound muscle action potentials (CMAPs) after proximal stimulation showed an amplitude reduction between axilla and Erb's point for the median and ulnar nerves on both sides. His weakness as well as the amplitude reduction improved after administration of prednisolone. Demyelinative conduction abnormalities can be limited to the proximal segments for at least several months in a conduction equivalent to chronic inflammatory demyelinating polyneuropathy (CIDP).

Demyelinating Diseases↗
PubMed1998

Brain muscarinic receptors in progressive supranuclear palsy and Parkinson's disease: a positron emission tomographic study.

OBJECTIVES: To assess muscarinic acetylcholine receptors (mAChRs) in the brains of patients with progressive supranuclear palsy and Parkinson's disease, and to correlate the cholinergic system with cognitive function in progressive supranuclear palsy and Parkinson's disease. METHODS: Positron emission tomography (PET) and [11C]N-methyl-4-piperidyl benzilate ([11C]NMPB) was used to measure mAChRs in the brain of seven patients with progressive supranuclear palsy, 12 patients with Parkinson's disease, and eight healthy controls. All of the patients with progressive supranuclear palsy were demented. The Parkinson's disease group consisted of 11 non-demented patients and one demented patient. The mini mental state examination (MMSE) was used to assess the severity of cognitive dysfunction in all of the subjects. The modified Wisconsin card sorting test (WCST) was used to evaluate frontal cognitive function in the non-demented patients with Parkinson's disease and controls. RESULTS: The mean K3 value, an index of mAChR binding, was significantly higher for the frontal cortex in the patients with Parkinson's disease than in the controls (p<0.01). By contrast, the patients with progressive supranuclear palsy had no significant changes in the K3 values of any cerebral cortical regions. The mean score of the MMSE in the progressive supranuclear palsy group was significantly lower than that in the control group. Although there was no difference between the Parkinson's disease and control groups in the MMSE, the non-demented patients with Parkinson's disease showed significant frontal lobe dysfunction in the WCST. CONCLUSIONS: The increased mAChR binding in the frontal cortex of the patients with Parkinson's disease may reflect denervation hypersensitivity caused by loss of the ascending cholinergic input to that region from the basal forebrain and may be related to frontal lobe dysfunction in Parkinson's disease. The cerebral cortical cholinergic system may not have a major role in cognitive dysfunction in progressive supranuclear palsy.

Aged↗
PubMed1998

D-penicillamine treatment for chronic sensory ataxic neuropathy associated with Sjögren's syndrome.

Beneficial treatment has not been established for chronic sensory ataxic neuropathy associated with Sjögren's syndrome (CSAN-SS). We describe two patients with CSAN-SS who clinically improved in response to D-penicillamine treatment. Their neuropathic symptoms were lessened after D-penicillamine, and the results of electrophysiologic studies support the clinical improvement. D-Penicillamine can be considered a potentially beneficial agent in the treatment of CSAN-SS.

Adult↗
PubMed1998

Two patterns of clinical recovery in Guillain-Barré syndrome with IgG anti-GM1 antibody.

OBJECTIVE: To investigate the prognostic value of anti-GM1 antibody. BACKGROUND: Whether anti-GM1 antibody is a marker of poor prognosis due to axonal degeneration in Guillain-Barré syndrome (GBS) is a matter of controversy. METHODS: The clinical recovery of 41 consecutive GBS patients was analyzed. RESULTS: The Hughes functional grading scores were similar at the peak, and 1, 3, and 6 months after onset for the groups of patients with (n=19) and without (n=22) immunoglobulin (Ig) G anti-GM1 antibodies. However, the anti-GM1-positive group included significantly higher proportions of patients with poor recovery (inability to walk independently at 6 months, 5 of 19 versus 0 of 22; p=0.01) and those with a markedly rapid recovery (improvement by two or more Hughes grades within a month, 9 of 19 versus 4 of 22; p=0.05). The positivity of IgG anti-GM1 antibody correlated well with the electrodiagnosis of the acute motor axonal neuropathy pattern but was not always associated with poor prognosis. Anti-GM1-positive patients showed two different patterns of clinical recovery-their conditions improved slower or faster than those of the anti-GM1-negative patients, most of whom had acute inflammatory demyelinating polyneuropathy. CONCLUSIONS: Anti-GM1 antibody is not always a marker of poor prognosis and, besides axonal degeneration, early reversible effects other than demyelination could be part of the pathophysiology of Guillain-Barré syndrome with IgG anti-GM1 antibody.

Adult↗
PubMed1997

Characterization of differentiation antigens expressed in bovine lymphosarcomas.

To characterize the cell-surface antigens expressed in tumour cells derived from bovine leukosis and to determine their cell lineages, the immunophenotypes of the tumour cells from 13 bovine lymphosarcomas were examined with 13 monoclonal antibodies (mAbs). Of 13 cattle with lymphosarcomas, four were identified clinically as having the thymic-type sporadic bovine leukosis (SBL) and one as having the skin-type; two had enzootic bovine leukosis (EBL) and six were untypable. Flow cytometric analysis revealed that the tumour cells from nine cases were of T-cell lineage (BoCD5+, BoCD2+ or BoCD2-) and two were of B-cell lineage (MHC-II+, BoCD5+, IgM+); there were two bovine leukaemia virus-infected cattle (EBL). T-cell tumours appeared to originate from immature (BoCD4-, BoCD8-) T cells, but there was no significant relationship between clinical type (EBL, calf-, skin- and thymic-type) and tumour-cell immunophenotype.

Animals↗
PubMed1997

Further analysis of the phenotype and distribution of tumor cells in sporadic B-cell and T-cell lymphomas in the lymph node and spleen of cattle.

Immunohistologic studies were performed to identify the phenotype and distribution of neoplastic lymphocytes in the spleens of BLV-negative animals examined by PCR and diagnosed as having sporadic bovine leukosis. Tumor cells from three cases of sporadic bovine leukosis were identified as of B-cell lineage. Tumor cells from three additional cattle were identified as CD3+ CD4- CD8+, CD3+ CD4- CD8-, and CD3+ CD4- WC1+, respectively. The last case was diagnosed as a gamma/delta T-cell lymphoma. Differences in morphology proliferative characteristics were recognized between B- and T-cell type lymphomas. The tumor cells in B-cell type lymphoma were characterized as follows: medium or large in size, round or polymorphic nucleus with rough chromatin with some tumor cells containing a convoluted nucleus. These tumor cells of B-cell type lymphoma were present in the red pulp and periarteriolar lymphoid sheath. Tumor cells of the T-cell type lymphoma were uniformly smaller than B-cell type and present around arteries or replaced red pulp of the spleen.

Animals↗
PubMed1997

p53 mutation as a potential cellular factor for tumor development in enzootic bovine leukosis.

Mutations of p53 in the lymphocytes from peripheral blood and from tumoral lymph nodes in six naturally occurring bovine leukemia virus (BLV)-infected cows were examined. A point mutation of the p53 gene was found in three of six (50%) BLV-infected cows. These p53 gene mutations resulted in amino acid substitutions of codons 144, 167 and 241. The BLV-infected cow in the tumor stage had abnormally proliferating monoclonal B-lymphocytes having the p53 mutation. However, the mutation was not found in somatic cells, except for tumor cells. These results show that p53 mutation plays an important role in the pathogenesis of BLV-induced neoplasms, and that the B-lymphocyte bearing p53 mutations may be a target cell for tumor formation of enzootic bovine leukosis.

Animals↗
PubMed1997

Identification and mRNA developmental profiles of two ultraspiracle isoforms in the epidermis and wings of Manduca sexta.

cDNAs were isolated from Manduca sexta that encode two isoforms of an ultraspiracle (USP) homologue MsUSP-1 and MsUSP-2 with different N-terminal A/B regions. The MsUSP-1 cDNA predicts a protein with 97% and 45% amino acid identities in the DNA- and ligand-binding domains respectively to the Drosophila USP and 89% overall identity with Bombyx mori CF1 (an USP homologue). Northern blot hybridizations with probes specific to MsUSP-1 and MsUSP-2 showed transcripts of an approximately equal size (4.5 kb), but with diverse developmental profiles in Manduca epidermis during the two final larval instars and the onset of the adult moult. The MsUSP-1 mRNA was expressed during the intermoult periods, with higher levels around the time of the larval ecdyses and at the onset of wandering behaviour. In contrast, the MsUSP-2 mRNA was up-regulated at times of high ecdysteroid titre during the larval moults, when the MsUSP-1 mRNA disappeared. Together, these conversely regulated isoform mRNAs contribute to the constitutive expression profile of total MsUSP mRNA.

Amino Acid Sequence↗
PubMed1997

[Muscarinic cholinergic receptor imaging of parkinsonian brain using 11C-NMPB and PET].

11C-NMPB is a useful ligand which is used to measure brain muscarinic cholinergic receptors (mAChRs) for its high affinity and high brain uptake. PET images of 11C-NMPB uptake had the highest accumulations in the cerebral cortex and striatum and the lowest in the cerebellum, both in patients with Parkinson's disease (PD) and normal subjects. 11C-NMPB uptake was homogeneous throughout the cerebral cortex in the normal subjects but greater in the frontal cortex of about one half of the PD patients as compared with other cerebral cortical areas. Quantitative analysis showed that the PD patients had high K3 values, an index of mAChR binding, in the frontal cortex. In PD, increased mAChR binding in the frontal cortex may be related to frontal lobe dysfunction. This technique should prove useful for detecting subclinical impairment of the central cholinergic system in PD.

Animals↗
PubMed1996

B-1a, B-1b and conventional B cell lymphoma from enzootic bovine leukosis.

In order to characterize the phenotypes of tumor cells and to clarify from which B cell lineage the lymphomas were derived, ten cows with enzootic bovine leukosis were examined by means of immunohistologic staining and flow cytometry. The tumor cells expressed mainly major histocompatibility complex (MHC) class II+ (10/10), BoCD11b+ (9/10), IgG1+ (8/10), B-B2+ (8/10) BoCD5+ (7/10), and lambda light chain+ (7/10). Tumor cells from only one animal expressed sIgM+ (1/10). Tumor cells from all ten animals were negative for IgG2, BoCD3, BoCD4, BoCD8, WC1-N2, and IL-2R alpha. The phenotypes of these tumor cells were all slightly different, suggesting that bovine leukemia virus (BLV)-induced lymphoma expresses phenotypic diversity. Moreover, tumor cells from seven cattle coexpressed BoCD5 and BoCD11b (B-1a cells). On the other hand, tumor cells from two of them only expressed BoCD11b (B-1b cells), and those from one were negative for both BoCD5 and BoCD11b (conventional B cells). Therefore, we concluded that BLV-induced lymphoma cells can be derived from B-1a, B-1b and conventional B cells.

Animals↗
PubMed1996

The proto-oncogene c-myb is expressed in sporadic bovine lymphoma, but not in enzootic bovine leukosis.

We examined bovine c-myb gene expression in six samples of sporadic bovine lymphomas (two calf, three thymic and one intermediate) and five of enzootic bovine leukosis. Tumor cells of the sporadic bovine lymphomas were of immature cell lineage (one B lymphoma and five T lymphomas). The c-myb mRNA was expressed in almost all the sporadic bovine lymphomas (except for one thymic form) including a BoCD8 single positive T lymphoma. On the contrary, c-myb was not expressed in mature B lymphomas of enzootic bovine leukosis. The results suggest that c-myb expression is closely associated with tumor cell differentiation of bovine lymphomas.

Animals↗
PubMed1996

[A case of relapsing demyelinating multiple mononeuropathy with multifocal nerve enlargement].

We report a 23-year-old woman, who had a relapsing-remitting multiple mononeuropathy with multifocal nerve enlargement. The patient was characterized by asymmetrical, marked enlargement of multiple nerves in the arms (median and ulnar nerves) and neck (accessory nerve) bilaterally. Sequential nerve conduction studies revealed persistent demyelinative abnormalities, especially across the segment of nerve thickening. The MRI of the proximal arm confirmed the markedly enlarged median and ulnar nerves which showed high signal intensity on T2-weighted images and partial enhancement after administration of gadolinium. We consider that the patient had the clinical features of "multifocal pseudohypertrophic neuropathy" described by Adams et al, and that chronic demyelination and inflammation associated with impairment of the blood-nerve barrier might be underlying mechanisms.

Adult↗
PubMed1995

Nucleotide sequence and the molecular evolution of a new A2 gene in the DQ subregion of the bovine major histocompatibility complex.

cDNA clones encoding the bovine major histocompatibility complex (MHC) class II DQ alpha chain were isolated. One clone, MQ9, encoded a primary translated product of 255 amino acids, with a signal peptide of 23 amino acids and a mature polypeptide of 232 amino acids. A new A2 gene in the DQ subregion of the bovine genome was identified from a comparison of amino acid sequences encoded by class II A genes among several species and the construction of a phylogenetic tree. It was revealed that MQ9 is most closely related to the ovine DQA2 genes among sequences from various mammalian species. By contrast, the BoLA-DQA genes previously isolated are more closely related to ovine DQA1 than to the BoLA-DQA2 gene, and they represent BoLA-DQA1 genes. Thus, the presence of two BoLA A genes, which may be expressed and functional in the bovine, as well as in sheep was confirmed. A large number of amino acids unique to products of DQA2 genes of bovine and ovine origin were identified when the predicted amino acid sequences for both species were compared, and most of the DQA2-specific residues were located in the alpha 1 domain and were conserved with respect to products of DQA1 genes of ruminants. Thus, several characteristics of the bovine DQA genes were found to differ from those of human and rodent genes, despite similarities in gene structure and in nucleotide sequence.

Amino Acid Sequence↗
PubMed1995

Identification of a new bovine MHC class II DRB allele by nucleotide sequencing and an analysis of phylogenetic relationships.

Three overlapping cDNA clones coding for the bovine major histocompatibility complex (MHC) class II DR beta chain were isolated. A clone NR1 encoded a primary translated product of 266 amino acids, 29 of which were deduced to form a signal peptide and 237 to form the mature polypeptide. The protein predicted from this cDNA appeared to have all the features expected of an expressed MHC class II molecule. Comparison of the sequences and construction of a phylogenetic tree revealed that NR1 represents a BoLA-DRB3 gene and not a BoLA-DRB1 or BoLA-DRB2 pseudogene. NR1 and ovine sequences exhibited the greatest overall similarity among sequences from various mammalian species, followed by the equivalent human sequences. Indeed, the bovine allele was more closely related to certain ovine alleles than to other bovine alleles. A large number of replacement substitutions were identified when beta 1 domains encoded by NR1 and each of the 36 distinct BoLA-DRB3 alleles were compared, and most of the allelic variations were found in regions that are commonly polymorphic in DRB sequences from different species and correspond to the predicted antigen-recognition site. Thus, the predicted structure of the unique NR1 allele for BoLA-DRB3 further confirms the overall conservation of the product of this locus, as previously established from studies in rodent and man.

Alleles↗
PubMed1995

Hypersensitivity of cortical muscarinic receptors in Parkinson's disease demonstrated by PET.

The status of muscarinic receptors (mAChRs) is not clear in Parkinson's disease (PD). We measured mAChR binding in the brain of eight patients with PD and eight, age-matched, healthy controls by positron emission tomography (PET) and [11C]N-methyl-4-piperidyl benzilate ([11C]NMPB). PD patients were not demented according to DSM III criteria but showed significant frontal lobe dysfunction in the Modified Wisconsin Card Sorting Test. A mean K3 value, which is an index of mAChR binding calculated by a graphical method, was 20% higher in the frontal cortex of PD patients than controls (p < 0.05). Hypersensitivity of mAChRs in the frontal cortex of PD patients may be a response to a loss of ascending cholinergic input to that region, and may relate to frontal lobe dysfunction in PD.

Aged↗
PubMed1995

Immunohistologic studies on subpopulations of lymphocytes in cattle with enzootic bovine leukosis.

The distribution of subpopulations of lymphocytes in lymph nodes and tumors from cattle with enzootic bovine leukosis (EBL) was examined by immunohistochemistry using a panel of monclonal antibodies against leukocyte differentiation molecules of EBL. The lesions in lymph nodes could be divided into three types based on the extent of infiltration and proliferation of neoplastic cells with provirus and differential expression of leukocyte differentiation molecules. The number of B-B2+, sIgM+ cells was reduced in frequency in follicles during the neoplastic cell proliferation. CD4- and CD8-positive alpha/beta T cells and gamma/delta T cells positive for WC1 (workshop cluster designation) were also reduced in frequency in areas infiltrated with neoplastic cells. Almost all neoplastic cells were B-B2- and IgM-positive. However, there were a few B-B2- and/or IgM-negative cells or cells stained faintly in all cases. WC1+ cells were not observed in tumor tissues. However, CD4+ and CD8+ cells were observed throughout tumor tissues, suggesting a role for these cells in tumor immunity.

Animals↗