Biomedical subjects

K Nagashima

Publications and source records attributed to K Nagashima.

At least 163 records · Page 9Linked to original sources

PubMed1998

Reactivation of herpes simplex virus type 1 in patients with Bell's palsy.

Reactivation of herpes simplex virus type 1 (HSV-1) has been implicated in the pathogenesis of idiopathic peripheral facial palsy (Bell's palsy). The present study used the polymerase chain reaction (PCR) to analyze the saliva of patients with Bell's palsy for the presence of shed HSV-1. The study involved 47 patients with Bell's palsy, 24 patients with Ramsay Hunt syndrome, and 16 healthy HSV-seropositive volunteers. HSV-1 DNA was not detected in the saliva samples from HSV-seronegative patients. The prevalence of shed HSV-1 in patients with Bell's palsy (50%) was significantly higher than that in healthy volunteers (19%, p<0.05). When saliva samples were tested within 7 days after the onset of palsy, the prevalence of shed HSV-1 in patients with Bell's palsy (40%) was significantly higher than that in patients with Ramsay Hunt syndrome (7%, p<0.05). Furthermore, HSV-1 usually became undetectable by the second week after the onset of Bell's palsy when HSV-1 was detected during the acute phase of the disease. These findings strongly suggest that reactivation of HSV-1 is involved in the pathogenesis Bell's palsy, and indicate that PCR is a useful tool for early diagnosis of HSV-1 reactivation in patients with Bell's palsy.

Antibodies, Viral↗

PubMed1998

Adenoma with clear cell change of the large intestine.

BACKGROUND AND OBJECTIVES: Clear cell change of the large intestinal neoplasm is rare, and its character remains unclear. We report a case of the large intestinal adenoma with clear cell change with immunohistochemical and molecular studies to investigate whether the clear cell change is associated with a malignant progression of the adenoma. METHODS: We studied the histochemical and immunohistochemical staining characteristics of the tumor by staining with hematoxylin-eosin, periodic acid-Schiff, alcian blue, and by immunostaining using antibodies against carcinoembryonic antigen, epithelial membrane antigen, p53, and Ki-67. The c-K-ras codon 12 point mutations were analyzed using a nonradioactive restriction fragment length polymorphism technique. RESULTS: The tumor was composed of a typical tubular adenoma and a tubular adenoma with clear cytoplasm. The clear cytoplasm was negative by mucin stains. Immunohistochemically p53 was negative in both the components. Labeling index of Ki-67 showed no significant difference between the two components. No codon 12 mutation of c-K-ras gene was observed in both the components. CONCLUSION: These findings suggest that the clear cell change of the tubular adenoma is not associated with a malignant progression in adenoma-carcinoma sequence involving c-K-ras and p53.

Adenoma↗

PubMed1998

Neuropathological and molecular studies of spinocerebellar ataxia type 6 (SCA6).

SCA6 is an autosomal dominant spinocerebellar ataxia (SCA) caused by a small CAG repeat expansion of the gene encoding an alpha-1A-voltage-dependent Ca channel gene subunit on chromosome 19p13. A Japanese woman with SCA6, with a 7-year history of progressive pure cerebellar ataxia, died of malignant lymphoma. Systematic neuropathological examination showed that neuronal degeneration was confined to the cerebellar Purkinje cells and, to a lesser degree, the granular cells, without any involvement of other central nervous system structures. Such pathological selectivity correlates with the localized expression of the responsible gene, and coincides with the neurological manifestation. These findings might contribute to establishing the phenotype of the SCA6 via comparison with other dominant ataxias.

Age of Onset↗

PubMed1998

Expression of oncogenic molecules in primary central nervous system lymphomas in immunocompetent patients.

We studied overexpression of p53, Bcl-2, Bcl-6, c-Myc and Mdm2 proteins by immunohistochemistry for a total of 27 primary central nervous system B cell lymphomas (CNS lymphomas) in immunocompetent patients and one CNS lymphoma in an AIDS patient. The expression of Epstein-Barr (EB) virus-encoded small RNA-1 (EBER-1) was also analysed using in situ hybridisation. Overexpression (more than 20% of cells stained) of p53 protein was detected in 8 of 27 immunocompetent cases (30%); 6 cases showed a nuclear stain and 2 cases showed cytoplasmic stain (nuclear exclusion). Strong Bcl-2 or Bcl-6 immunoreactivity suggestive of overexpression was seen, respectively, in 5 (19%) and 6 (22%) cases; 2 cases were positive for both immunoreactivities. Interestingly, overexpression of Bcl-2 or Bcl-6 was not seen in the cases which showed p53 overexpression (P < 0.03; chi-square test). EBER-1 expression was not detected in any of the 27 immunocompetent cases, but was found in the AIDS-related CNS lymphoma, which also showed an overexpression of Bcl-6, but not Bcl-2. None of the cases showed c-Myc or Mdm2 overexpression. Taken together, it is suggested that CNS lymphoma in immunocompetent hosts is a distinct disease that has a different molecular profile from those of systemic lymphoma and/or AIDS-related CNS lymphoma.

Acquired Immunodeficiency Syndrome↗

PubMed1998

Amplification of JC virus regulatory DNA sequences from cerebrospinal fluid: diagnostic value for progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease in the central nervous system caused by a ubiquitous human polyomavirus designated as JC virus (JCV). PML affects individuals with decreased immune competence and is now one of the common opportunistic infections in patients with AIDS. JCV DNAs in the brain of PML patients contain various PML-type regulatory regions that were generated from the archetypal regulatory region during persistence. Recently, many studies have suggested that detection of JCV DNA from the cerebrospinal fluid (CSF) may offer a tool for diagnosing PML. However, in all of these studies, coding sequences within the T antigen or capsid protein gene have been targeted for amplification. To amplify the JCV regulatory region, we established a nested PCR that could efficiently amplify the regulatory region from most JCV subtypes prevalent in the world. Using this PCR, we amplified JCV regulatory regions from the CSF samples from 4 patients strongly suspected of PML, whereas amplification was negative from 80 CSF samples from patients without PML. Sequencing of the amplified fragments revealed that they had unique deletions and/or duplications. Furthermore, in 3 PML patients, we analyzed the structures of regulatory regions derived from the brain as well as CSF. In each of these cases, the major regulatory sequence of both origins were identical. This finding indicates that JCV DNA in brain lesions is excreted in the CSF. Since the structures of PML-type JCV regulatory regions are unique to individual patients, the current PCR, if the amplified fragments are sequenced, can eliminate false positives that may arise from contaminations.

Brain↗

PubMed1998

Surgical treatment of neuroblastomas in infants under 12 months of age.

BACKGROUND: Surgical treatment of neuroblastomas, both those detected by screening and those detected clinically, in infants less than 12 months of age, is controversial, because some tumors in this age group potentially have the ability to regress spontaneously. METHODS: From January 1985 to March 1997, the authors treated 50 infants (under 1 year of age) with neuroblastoma: 23 boys and 27 girls. Forty-one cases were detected preclinically by screening when the patients were 6 to 11 months of age (median, 7 months), and nine patients were discovered to have clinical manifestations at the age of 1 to 10 months (median, 4 months). RESULTS: The tumor was INSS stage 3 or 4 in 10 patients (24%) with screening-detected tumor and in five (56%) with clinically detected tumor, although the difference was not statistically significant. Four screening-positive patients had multifocal primary tumors, and three of them were synchronous bilateral adrenal neuroblastomas. There was no statistically significant difference between the screening-detected tumors and the clinically detected tumors in biological characteristics such as Shimada's histology, DNA ploidy, and N-myc amplification. Complete resection of the primary lesion was accomplished by either primary surgery or second look (delayed primary) surgery in 46 patients (92%), and the resection was incomplete in the remaining four. In patients with bilateral adrenal tumors, the larger one was primarily resected, and the smaller contralateral tumor was enucleated or resected by partial adrenalectomy. Surgical complications included postoperative adhesive ileus (n=2), Horner's syndrome (n=2), renal atrophy (n=1), renal failure (n=1), phrenic nerve injury (n=1), chylous ascites (n=1), chylothorax (n=1) and intussusception (n=1). One patient died of respiratory failure caused by a complication, but 49 patients (98%) were alive at the time of evaluation. CONCLUSION: When considering surgical treatment of infants with biologically favorable neuroblastoma, the risk involved in treatment should be weighed against the risk inherent in a tumor capable of spontaneous regression, and aggressive surgery is unacceptable.

Adrenal Gland Neoplasms↗

PubMed1998

Congenital aural sinuses: clinical study and application of microsurgery.

METHODS: The authors studied 45 cases of congenital aural sinuses. RESULTS: Aural sinuses were observed on both sides in 17 cases (37.8%) and in girls (24 cases, 53.3%). Family history was positive in 12 cases (26.6%), and history of local infection was present in 40 cases (88.9%). The opening of aural sinuses was located most frequently in the marginal helicine region (36 cases, 80%). CONCLUSIONS: Microsurgery was extremely effective for accurate determination of the margins of intricately ramified aural sinuses, their detachment from surrounding tissues, and their total resection. Complete resolution without postoperative complications was achieved in 43 cases (95.6%).

Adolescent↗

PubMed1998

Adrenocortical tumor in a patient with familial adenomatous polyposis: a case associated with a complete inactivating mutation of the APC gene and unusual histological features.

Familial adenomatous polyposis (FAP) is an autosomal dominant hereditary disorder caused by a germline inactivating mutation of the adenomatous polyposis coli (APC) gene. Patients with FAP sometimes develop various extracolonic manifestations including adrenocortical neoplasms. We present a 14-year-old boy with FAP who had an adrenocortical tumor with atypical histopathologic features, ie, sex-cord-like differentiation. Immunohistochemical studies of adrenal 4 binding protein (Ad4BP) and steroidogenic enzymes showed the capacity of these tumor cells to produce steroids. Genetic analysis of the tumor disclosed a two-hit mutation in APC: a germline 5-base pair deletion accompanied by a loss of the normal allele. Because there were no reports of genetic alterations in adrenocortical tumors developed in FAP patients, we examined 10 sporadic adrenal tumors (four carcinomas and six adenomas) for mutations in APC. However, no mutations were found in these 10 sporadic adrenal tumors. These results suggest that mutation of APC is also responsible for some fraction of the adrenocortical tumors: the tumor in this case is included.

Adenoma↗

PubMed1998

Cyclin D1 gene amplification in esophageal carcinosarcoma shown by differential polymerase chain reaction.

We studied cyclin D1 gene amplification in four esophageal carcinosarcomas using the differential polymerase chain reaction. Three cases showed amplification in the sarcomatous components, and one of these also showed amplification in the carcinomatous component. No amplification was detected in the other case. We also examined p53 expression in these four tumors by immunostaining. Both components of all four cases showed diffuse overexpression of p53 protein in the nuclei. Our results showed that the cyclin D1 gene is frequently amplified in esophageal carcinosarcoma, especially in the sarcomatous component. Two cases showed amplification only in the sarcomatous component, suggesting that amplification may have a role in the pathogenesis of that component of this malignancy. The diffuse overexpression of p53 observed in both components suggests that such overexpression, which could be the result of somatic mutation, might be an early event in the pathogenesis of esophageal carcinosarcoma.

Blotting, Southern↗

PubMed1998

Immune response to recombinant visna virus Gag and Env precursor proteins synthesized in insect cells.

Two different recombinant visna virus (VV) gag-baculoviruses were constructed for the expression of precursor VV Gag in insect cells. Both recombinant Gag viruses expressed proteins migrating on SDS PAGE at the predicted rate for VV Gag precursor, Pr50gag. However, differences were seen in the morphology of the virus-like particles produced. Monoclonal antibody directed against the VV Gag capsid protein (p25) and sera from sheep infected with ovine lentiviruses reacted to both 50-kDa proteins. A recombinant VV env-baculovirus was constructed, substituting sequences encoding the signal peptide of VV Env with the murine IFN-gamma analogue. Sera from ovine lentivirus infected sheep reacted in immunoblots with two proteins of approximately 100 and 200 kDa found in the plasma membrane of insect cells infected with env-recombinant virus. Sheep immunized with either the recombinant Gag or the Env proteins developed high antibody titers to VV in ELISA. The serum of sheep and ascitic fluid of mice immunized with the recombinant Gag reacted with native Pr50gag and the processed Gag proteins in immunoblots, whereas serum of the recombinant Env immunized sheep reacted with VV gp135 and a putative oligomer of gp135. The immunized sheep responded specifically to visna virus by lymphocyte proliferation in vitro.

Animals↗

PubMed1998

Constitutive association of EGF receptor with the CrkII-23 mutant that inhibits transformation of NRK cells by EGF and TGF-beta.

Crk belongs to the adapter proteins that participate in many signalling pathways from cell surface receptors. We have characterised the CrkII-23 mutant that inhibits the transformation of NRK cells induced by epidermal growth factor (EGF) and transforming growth factor (TGF)-beta. To study the biochemical difference, cDNAs of the wild-type CrkII and the CrkII-23 mutant were introduced stably into NIH 3T3 cells expressing EGF receptor (EGFR). Both CrkII and CrkII-23 were phosphorylated on tyrosine upon EGF simulation with similar time course and dose dependency. Whereas the wild-type CrkII bound to EGFR only after EGF stimulation, CrkII-23 bound to EGFR from before stimulation. Mutation in the Src homology (SH) 2 or amino-terminal SH3 domain did not abolish the binding of CrkII-23 to EGFR in the quiescent cells, suggesting that the binding is mediated by a novel mechanism. These CrkII-23-derived mutants, however, did not suppress transformation of NRK cells by EGF and TGF-beta. Hence, both the SH2 and amino-terminal SH3 domains are required to inhibit transformation of NRK cells. These results suggest that persistent signalling from CrkII-23 bound to EGFR suppresses transformation by EGF and TGF-beta in NRK23 cells.

3T3 Cells↗

PubMed1998

A new deleted allele in the human cytochrome P450 2A6 (CYP2A6) gene found in individuals showing poor metabolic capacity to coumarin and (+)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one hydrochloride (SM-12502).

The S-oxidation of (4)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one hydrochloride (SM-12502) and the 7-hydroxylation of coumarin are primarily catalyzed by cytochrome P450 2A6 (CYP2A6). The activities of SM-12502 S-oxidase and coumarin 7-hydroxylase were investigated with liver microsomes from 20 human individuals. Liver microsomes from individual H16 showed the lowest activities of both enzymes. The expression of CYP2A6 protein was not detectable in liver microsomes from individuals H4, H5, H7, H8, H12 and H16. CYP2A6 mRNA was hardly detectable in the liver of the individual H16. A new SacI-restriction fragment length polymorphism showing the lack of a 2.6 kb fragment was found in two of forty genomic DNA preparations from individuals H16 and No. 594, using CYP2A6 cDNA as a probe. This deletional 2.6 kb fragment was isolated from a genomic library prepared from one individuals showing normal coumarin 7-hydroxylase activity and was sequenced. This fragment contained a CYP2A6 gene region from 319 bp upstream of a putative exon 6 to a SacI site in exon 9, indicating that this region was deleted in the two individuals in this study. We also demonstrated by polymerase chain reaction analysis that the exon 8 of CYP2A6 gene was deleted in individuals H16 and No. 594. These results indicate that the reduced activity of SM-12502 S-oxidase and no activity of coumarin 7-hydroxylase are caused by the lack of CYP2A6 mRNA and CYP2A6 protein caused by the CYP2A6 gene deletion.

Aryl Hydrocarbon Hydroxylases↗

PubMed1998

Diagnosis of synovial sarcoma with the reverse transcriptase-polymerase chain reaction: analyses of 84 soft tissue and bone tumors.

The chimeric transcript SYT-SSX is generated as a result of reciprocal translocation t(X;18), which is the primary cytogenetic abnormality found in, and appears to be specific for, synovial sarcoma. We performed a reverse transcriptase-polymerase chain reaction (RT-PCR) for SYT-SSX transcripts in a series of 84 tumors (61 soft tissue tumors and 23 bone tumors), including a variety of histologic types, to assess its usefulness in molecular diagnosis. Ten synovial sarcomas, three tumors initially unclassified, and one malignant peripheral nerve sheath tumor contained the chimeric transcripts. A review of the original slides and additional examination showed that a diagnosis of synovial sarcoma was appropriate for these cases. Additionally, in situ hybridization with an SSX1 probe indicated that the chimeric transcripts exist not only in the cells of special components but also in cells showing a variety of histologic patterns. Therefore, RT-PCR can be considered a useful molecular biological technique that can provide objective evidence for diagnosis of synovial sarcoma. Northern blot analysis with an SSX1 probe also detected chimeric SYT-SSX transcripts in the synovial sarcoma cases. The additional smaller bands, however, were also detected in six peripheral primitive neuroectodermal tumors (pPNETs) and one embryonal rhabdomyosarcoma. In five of these pPNETs, other bands ranging in size from 2.0 to 2.2 kb were also found, and it seems possible that these bands might represent novel karyotypic aberrations and/or splicing variants of SSX.

Adult↗

PubMed1998

Cyclin D1 gene amplification and p16 gene deletion in patients with esophageal carcinosarcoma.

Cyclin D1 (CD1) gene amplification is frequently observed in esophageal carcinosarcoma by differential polymerase chain reaction (DPCR). In this study, fluorescence in situ hybridization (FISH) was performed to show more direct evidence of CD1 gene amplification in patients with esophageal carcinosarcoma. FISH results were also compared with DPCR results studied previously. FISH analysis revealed CD1 gene amplification in all four patients with esophageal carcinosarcoma. CD1 gene amplification occurred with a high incidence in both components of esophageal carcinosarcoma, suggesting that CD1 gene amplification could have an important role in malignant transformation processes of esophageal carcinosarcoma. The results of the current study also suggest that FISH is a more sensitive method than DPCR. Because inactivation of p16 gene (which is a putative tumor suppressor gene) is thought to have similar oncogenic effects with CD1 gene amplification, DPCR was used to examine whether p16 homozygous deletion occurs in esophageal carcinosarcoma. These results suggest that homozygous deletion of the p16 gene occurs less frequently than CD1 gene amplification in esophageal carcinosarcoma. It does not seem to be an alternative event to CD1 gene amplification, though the number of studied cases was small.

Aged↗

PubMed1998

Seminoma in a postmenopausal woman with a Y;15 translocation in peripheral blood lymphocytes and a t(Y;15)/45,X Turner mosaic pattern in skin fibroblasts.

We report an unusual case of a 55 year old Japanese woman with a seminoma but relatively normal menses. The patient was a phenotypic female with late onset menarche (18 years of age), who was amenorrhoeic for the first year, followed by menses of one to three days' slight flow with dysmenorrhoea, but an otherwise normal menstrual history. A typical seminoma was removed from the left adnexal region and an immature testis was identified separately as an associated right adnexal mass. Repeated karyotypic studies on peripheral blood lymphocyte cultures showed only 46,X,-Y,t(Y;15)(q12;p13). Cytogenetic examination of the patient's younger brother, who had fathered three healthy children, showed an identical karyotype. Mosaicism of 46,X,-Y,t(Y;15)(q12;p13)/45,X cell lines was found in skin samples from the patient's elbow and genital regions, although there were no clinical stigmata of Turner syndrome. An androgen receptor binding assay of cultured genital skin fibroblasts was negative. Molecular analysis using Southern blot hybridisation, PCR, and direct DNA sequencing showed that neither the patient nor her brother had a detectable deletion or other abnormalities of Y chromosome sequences, including the SRY (sex determining region of the Y chromosome) gene sequence. These findings suggest that Turner mosaicism of the 45,X cell line may have contributed to this atypical presentation in an XY female, although we cannot exclude abnormalities of other genes related to sex differentiation.

Blotting, Southern↗

PubMed1998

Role of plasma osmolality in the delayed onset of thermal cutaneous vasodilation during exercise in humans.

To elucidate the role of increased plasma osmolality (Posmol), which occurs during exercise in the regulation of cutaneous vasodilation (CVD) during exercise, we determined the relationship between the change in esophageal temperature (DeltaTes) required to elicit CVD (DeltaTes threshold for CVD) and Posmol during light and moderate exercise (30 and 55% of peak oxygen consumption, respectively) and passive body heating. Then we compared the relationship with the data obtained in our previous study [A. Takamata, K. Nagashima, H. Nose, and T. Morimoto. Am. J. Physiol. 273 (Regulatory Integrative Comp. Physiol. 42): R197-R204, 1997], in which we determined the relationships during passive body heating following isotonic (0.9% NaCl) or hypertonic (2 or 3% NaCl) saline infusions in the same subjects. Posmol values at 5 min after the onset of exercise were 287.5 +/- 0.9 mosmol/kgH2O during light exercise and 293.0 +/- 1.2 mosmol/kgH2O during moderate exercise. Posmol just before passive body heating was 289.9 +/- 1.4 mosmol/kgH2O. The DeltaTes threshold for CVD was 0.09 +/- 0.05 degrees C during light exercise, 0.31 +/- 0. 09 degrees C during moderate exercise, and 0.10 +/- 0.05 degrees C during passive body heating. The relationship between the DeltaTes threshold for CVD and Posmol was shown to be on the same regression line both during exercise and during passive body heating with or without infusions [A. Takamata, K. Nagashima, H. Nose, and T. Morimoto. Am. J. Physiol. 273 (Regulatory Integrative Comp. Physiol. 42): R197-R204, 1997]. Our data suggest that the elevated body core temperature threshold for CVD during exercise could be the result of increased Posmol induced by exercise and is not due to reduced plasma volume or the intensity of the exercise itself.

Adult↗

PubMed1998

Effect of continuous negative-pressure breathing on skin blood flow during exercise in a hot environment.

To assess the impact of continuous negative-pressure breathing (CNPB) on the regulation of skin blood flow, we measured forearm blood flow (FBF) by venous-occlusion plethysmography and laser-Doppler flow (LDF) at the anterior chest during exercise in a hot environment (ambient temperature = 30 degreesC, relative humidity = approximately 30%). Seven male subjects exercised in the upright position at an intensity of 60% peak oxygen consumption rate for 40 min with and without CNPB after 20 min of exercise. The esophageal temperature (Tes) in both conditions increased to 38.1 degreesC by the end of exercise, without any significant differences between the two trials. Mean arterial pressure (MAP) increased by approximately 15 mmHg by 8 min of exercise, without any significant difference between the two trials before CNPB. However, CNPB reduced MAP by approximately 10 mmHg after 24 min of exercise (P < 0.05). The increase in FBF and LDF in the control condition leveled off after 18 min of exercise above a Tes of 37.7 degreesC, whereas in the CNPB trial the increase continued, with a rise in Tes despite the decrease in MAP. These results suggest that CNPB enhances vasodilation of skin above a Tes of approximately 38 degrees C by stretching intrathoracic baroreceptors such as cardiopulmonary baroreceptors.

Adult↗

PubMed1998

Effects of posture on cardiovascular responses to lower body positive pressure at rest and during dynamic exercise.

We tested the hypothesis that cardiovascular responses to lower body positive pressure (LBPP) would be dependent on the posture of the subject and also on the background condition (rest or exercise). We measured heart rate (HR), mean arterial blood pressure (MAP), and cardiac stroke volume in eight subjects at rest and during cycle ergometer exercise (76 +/- 3 W) with and without LBPP (25, 50, and 75 mmHg) in the supine and upright positions. At rest, the increase in MAP was proportional to the increase in LBPP and was greater in the supine (6 +/- 2, 15 +/- 3, and 26 +/- 3 mmHg) than in the upright (2 +/- 3, 9 +/- 3, and 17 +/- 3 mmHg) position. During dynamic exercise, the increases in MAP evoked by 25, 50, and 75 mmHg LBPP were greater in the supine (13 +/- 2, 28 +/- 3, and 40 +/- 3 mmHg) than in the upright (7 +/- 3, 12 +/- 3, and 25 +/- 3 mmHg) position. We conclude that the systemic pressure response to LBPP is clearly dependent on the body position, with the larger pressure responses being associated with the supine position both at rest and during dynamic leg exercise.

Adult↗