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Biomedical subjects

T Nakada

Publications and source records attributed to T Nakada.

At least 19 recordsLinked to original sources
PubMed2006

Drug eruptions to contrast media in Japan.

BACKGROUND: In Japan, drug eruptions to nonionic iodinated contrast media have been reported since the products appeared on the market in 1986. OBJECTIVES: To evaluate this clinical finding, we analysed the number of patients with drug eruption to contrast media in our hospital from 1989 to 2003. METHODS: In total, 117 patients suspected of such drug eruptions were patch and intradermal tested with contrast media (as commercially sold). Those who tested positive were evaluated. RESULTS: Of the 117 patients, 69 patients (19 men; 50 women, mean +/- SD age 51.4 +/- 16.5 years, range 17-86) showed positive reactions to contrast media. The number was 6-13 annually from 1989 to 1995, and 1-4 annually from 1996 to 2003. CONCLUSION: Although our data suggest (but do not prove) that patients with drug eruption to contrast media decreased in number, this condition is still not rare in Japan. Higher annual exposure to contrast media, including pretesting, could play an important role in this observation.

Adolescent↗
PubMed2006

Parietal white matter abnormalities in obsessive-compulsive disorder: a magnetic resonance spectroscopy study at 3-Tesla.

OBJECTIVE: To identify a neurochemical basis for the hypothesis that an aberrant cortico-subcortical circuit underlies obsessive-compulsive disorder (OCD). The white matter was also investigated because of recent research which suggests the altered connectivity of axons. METHOD: Using 3-Tesla magnetic resonance spectroscopy, the relative concentrations of N-acetylaspartate (NAA) and choline-containing compounds (Cho) to creatine/phosphocreatine (Cr) were measured in the anterior cingulate, basal ganglia, thalamus, frontal and parietal white matter of 12 OCD patients, and 32 control subjects. RESULTS: The mean concentration of Cho/Cr was significantly higher in the patients than in the controls, but only in the parietal white matter, while no significant group differences in NAA/Cr were observed in any of the brain regions. Parietal Cho/Cr correlated positively with the severity of OCD symptoms. CONCLUSION: This finding provides indirect evidence for the parietal white matter involvement in OCD, thus suggesting a change in the phospholipids of myelinated axons and/or glia cells.

Adolescent↗
PubMed2005

Molecular cloning and functional expression of enolase from Trichinella spiralis.

The cDNA library was constructed from muscle larvae of Trichinella spiralis, and immunoscreened with sera from mice infected with T. spiralis. A cDNA clone, designated as TsENO, encoded 2-phospho-D-glycerate hydro-lyase (enolase) that catalyzed a reversible conversion of 2-phospho-D-glyceric acid (2PGA) to phosphoenolpyruvate (PEP) in the glycolytic pathway. The recombinant TsENO protein was produced in an Escherichia coli expression system. The recombinant full-length TsENO protein had no activity in the conversion of 2PGA to PEP, but gained enolase activity after cutting off the signal peptide from the full-length protein. There was no meaningful difference in the expression level of TsENO gene at three distinct stages of T. spiralis. Also, antibody against the recombinant TsENO protein reacted with crude extract of muscle larvae, but not with the excretory and secretory products.

Amino Acid Sequence↗
PubMed2004

Adult-onset leukoencephalopathy with vanishing white matter with a missense mutation in EIF2B5.

We report of a woman aged 52 years born to consanguineous parents and seeking treatment for progressive dementia and delusion. Neurologic examination revealed dementia and emotional instability, indifference, and confabulation. There was also mild spasticity of the bilateral lower limbs. MRI revealed diffuse white matter hyperintensity on T2-weighted images accompanied by hypointense areas on fluid-attenuated inversion recovery images. A homozygous missense mutation was identified in EIF2B5.

Adult↗
PubMed2004

Differences and similarities of nurse cells in cysts of Trichinella spiralis and T. pseudospiralis.

The nurse cell in the cyst of Trichinella spiralis comprises at least two kinds of cytoplasm, derived from muscle or satellite cells, as indicated by the pattern of staining using regular dye (haematoxylin and eosin, or toluidine blue), alkaline phosphatase (ALP) expression, acid phosphatase (ACP) expression and immunostaining with an anti-intermediate filament protein (desmin or keratin). Muscle cells undergo basophilic changes following a T. spiralis infection and transform to the nurse cells, accompanied by an increase in ACP activity and the disappearance of desmin. Satellite cells are activated, transformed and joined to the nurse cells but remain eosinophilic. The eosinophilic cytoplasm is accompanied by an increase in desmin and ALP expression but not an increase in ACP activity. Differences in the staining results for ALP or ACP suggest that the two kinds of cytoplasm have different functions. Trichinella pseudospiralis infection results in an increase of ACP activity at a later stage than T. spiralis. There is also a difference in the location pattern of ACP in the cyst of T. spiralis compared with T. pseudospiralis. In T. spiralis, ACP is diffused within the cell, but in T. pseudospiralis, ACP distribution is spotty corresponding to the location of the nucleus. Trichinella pseudospiralis infection is accompanied by a slight increase in ALP activity. Activated satellite cells following a T. pseudospiralis infection exhibit an increase in desmin expression. The present study therefore reveals that nurse cell cytoplasm differs between the two Trichinella species and between the two origins of cytoplasm in the cyst of T. spiralis.

Acid Phosphatase↗
PubMed2003

Molecular cloning and expression of the full-length tropomyosin gene from Trichinella spiralis.

A clone, designated as TsTM, was selected from the cDNA library of newborn larvae (NBL) of Trichinella spiralis through immunoscreening against infected sera. The clone contained a cDNA transcript of 855 bp in length with a single open reading frame, which encoded 285-amino acids (33 kDa in the estimated molecular weight). A sequence analysis revealed that the clone TsTM encoded the full-length of tropomyosin gene. The phylogenetic analysis of the tropomyosin gene was in good agreement with the classical taxonomical position of T. spiralis. The fusion proteins encoded by the clone TsTM were produced in an Escherichia coli expression system and affinity purified, and the antibody was raised against the protein for the following studies. The antibody against the fusion protein positively bound to the hypodermal muscle layer in immunolocalization analysis, and the 35 kDa band in crude extracts of muscle larvae but not in excretory and secretory (ES) products on Western blots. The antigenicity of the clone TsTM was recognized by host mice but exhibited little species specificity.

Amino Acid Sequence↗
PubMed2003

Molecular expression and characterization of a homologue of host cytokine macrophage migration inhibitory factor from Trichinella spp.

A homologue of cytokine macrophage migration inhibitory factor (MIF) from complementary DNA (cDNA) of Trichinella spiralis and Trichinella pseudospiralis was expressed in Escherichia coli and characterized. The sequence analysis indicated that the predicted amino acid sequence has an identity of 57 and 44% with the MIF of nematodes Trichuris trichiura and Brugia malayi respectively, and 41 and 40% with that of a human and a mouse, respectively. The identity in sequences of cDNA and amino acids between T. spiralis and T. pseudospiralis was 91 and 86%, respectively. Western blot analysis showed that anti-MIF antibodies positively stained proteins from the extracts of adult worms or muscle larvae migrating at about 12.5 kDa (3 isoforms with isoelectric point 5.23, 5.72, and 6.29). Semiquantitative reverse transcriptase-polymerase chain reaction revealed that the gene was expressed in various developmental stages, including in adult worms, newborn larvae, precyst muscle larvae, and postcyst muscle larvae, although there was difference in the expression level among these stages. The immunohistochemical analysis showed the MIF exists in the muscle cells of the body wall and some stichocytes of larvae. Histopathology of T. spiralis-infected muscles revealed an accumulation of mononuclear cells around the worms, and immunocytochemical staining showed these cells were not macrophages. Mononuclear cells, including macrophages, were, however, observed in cardiac muscles where the parasite did not encyst. Macrophages accumulated around the Sephadex beads transplanted in mice subcutaneously, but this accumulation was profoundly inhibited when the beads were pretreated with MIF recombinant protein.

Amino Acid Sequence↗
PubMed2003

[New surgical approach "intrapulmonary septation technic" for Fontan candidates with unilateral pulmonary arterial hypoplasia and/or pulmonary venous obstruction].

Unilateral pulmonary arterial hypoplasia and/or pulmonary venous obstruction are serious hazards for Fontan candidates. For these patients, we have started new surgical approach "intrapulmonary septation technic". This consists of 3 components; (A) partial right heart bypass to well-grown side, (B) mandatory pulmonary blood flow to low-capacity side, (aorto-pulmonary shunt or others) and (C) a patch between partial right heart bypass and mandatory pulmonary blood flow. Thirteen patients underwent the approach. The source of partial right heart bypass was brought from superior vena cava (11 patients), inferior vena cava (1 patient) and fenestrated Fontan (1 patient). The mandatory pulmonary blood flow was supplied by aorto-pulmonary shunt (11 patients), pulmonary arterial banding (1 patient) and native pulmonary valve stenosis (1 patient). We added pulmonary artery enlargement (9 patients), release of pulmonary venous obstruction (8 patients) and/or atrio-ventricular valve plasty (5 patients), simultaneously. No hospital death. Early post-operative course was uneventful in all cases except 1, as pulmonary blood flow to low-capacity side had increased gradually after this intervention. Eight patients had reached Fontan operation. In this approach, nearly whole pulmonary artery can grow without any affect of volume overload through well-grown side from collateral arteries of low-capacity side. All procedures of "intrapulmonary septation technic" and reconstruction of pulmonary artery in Fontan operation can be easily performed in larger pulmonary artery of well-grown side, eliminating need for extensive dissection.

Child↗
PubMed2002

Pre-operative histopathological evaluation of meningiomas by 3 0T T2R MRI.

BACKGROUND: To assess the potential of T2 reversed (T2R) magnetic resonance imaging (MRI) for the pre-operative histopathological assessment of meningiomas. METHOD: Twenty patients scheduled for meningioma resection were prospectively assessed using T2R MRI on a 3 tesla system. Image characteristics were compared with intra-operative findings and post-operative histopathological examination of excised meningioma tissues. FINDINGS: The averaged T2 characteristics expressed as averaged gray scale levels of the tumour correlated highly with tumour consistency, in agreement with previous reports. Furthermore, detailed evaluation of the structural appearance of tumour on T2R images revealed brightness of tumour (shorter T2) was dependent on the degree of histopathological heterogeneity. Significantly shorter T2 value correlated with collagen-rich fibrous tissue. INTERPRETATION: The study demonstrated the advantage of T2R imaging in pre-operative determination of histopathological characteristics of meningiomas. As a step towards MR microscopy and improved pre-operative treatment planning, T2R imaging on a 3.0 T system appears to play an important role in the non-invasive pre-operative structural assessment of a tissue of interest.

Adult↗
PubMed2002

Absence of microdeletions in the Y chromosome in patients with Prader-Willi syndrome with cryptorchidism.

Unilateral or bilateral cryptorchidism is found in 80-100% of male patients with Prader-Willi syndrome (PWS). Recently, the relationship between Yq deletions and cryptorchidism has been assessed. However, the relationship between Yq deletions and PWS patients with cryptorchidism remains unclear. Polymerase chain reaction (PCR) amplification of 51 DNA loci encompassing all of the regions for azoospermia factor (AZF) of the Y chromosome, including the deleted in azoospermia (DAZ) and ribonucleic acid-binding motif (RBM) genes, were examined for microdeletions in 10 PWS males with cryptorchidism and 20 healthy control male subjects. No microdeletions of 51 loci were found in any of the PWS males. The present study therefore suggests that microdeletions in the AZF regions of the Y chromosome do not relate to the occurrence of cryptorchidism in PWS patients.

Adolescent↗
PubMed2002

Effects of electropermeabilization after the administration of anticancer drugs on transitional cell carcinoma.

OBJECTIVE: To assess in vitro and in vivo the potential utility of electropermeabilization (EP) as an anticancer drug delivery system for the treatment of transitional cell carcinoma (TCC). MATERIALS AND METHODS: To analyse the effects of EP on the internalization of adriamycin and bleomycin by cells, aliquots of a suspension of YTS-1 carcinoma cells (derived from a human TCC line) were mixed with a solution of adriamycin or bleomycin and then exposed immediately to an electric field (1000 V/cm, 1 Hz, 100-micros square wave, eight pulses). After a 2-h incubation the concentration of each drug in the cells was measured by high-performance liquid chromatography (for adriamycin) and by bioassay (for bleomycin). The concentrations of drugs in the cells were compared with untreated cells. To analyse the effects of EP on cytotoxicity, the same treatments were applied to a suspension of cells plus adriamycin or bleomycin and then the cells incubated for 6 h with tritiated thymidine ([3H]-TdR), monitoring the incorporation of [3H]-TdR into the cells. Cells with no electrotreatment acted as controls. To assess the effects on tumours in vivo, YTS-1 cells were transplanted subcutaneously into nude mice; when the tumours had reached 7 mm in diameter, EP was applied (using electrical pulses as before, 10 min after the direct injection of bleomycin into the tumour). Tumours were then measured regularly and compared with sham-treated tumours, tumours treated with electric pulses alone, and tumours treated with bleomycin alone. Survival was also compared. RESULTS: There were no significant differences in the levels of adriamycin between cells with and with no EP, whereas there was a marked difference for bleomycin. Growth inhibition by adriamycin with and with no EP was similar, while the growth-inhibitory effects of bleomycin were almost doubled. There was a reduction in tumour size only in the group treated with bleomycin plus electric pulses and two of five tumours disappeared completely. Survival in this group was also significantly better than in the other groups. CONCLUSION: EP after administering bleomycin might be an effective treatment for TCC.

Animals↗
PubMed2002

Molecular cloning and characterization of a novel protein of Trichinella pseudospiralis excretory-secretory products.

A novel excretory-secretory (ES) protein of Trichinella pseudospiralis was produced. A cDNA library was constructed from mRNA of muscle larvae at 30 days post infection (p.i.) and immunoscreened with the antibody against ES products. A clone, designated Tp22-3, contained a cDNA transcript of 815 bp in length with a single open reading frame which encoded 244-amino acids (28407 Da in the estimated molecular mass). A database search revealed that no sequences had a homology to this predicted protein. The recombinant protein was produced in an Escherichia coli expression system. Stage specific expression of this protein was suggested from the following experiments. An antibody against the recombinant protein could stain proteins migrating at about 28 kDa (which is the expected size from the sequence) on Western blotting of crude extracts or ES products from 30 days p.i. muscle larvae, but failed to stain any proteins in crude extracts from newborn larvae or 15 days p.i. muscle larvae. The antibody reacted to the stichocytes of larvae at 30 days p.i., but did not react to 15 days p.i. muscle larvae. The production of an mRNA transcript for Tp22-3 gene was restricted largely to the 30 days p.i. muscle larvae and adult worms.

Amino Acid Sequence↗
PubMed2001

Human brain imaging in the upright position.

The authors obtained brain images with patients in the upright position using a newly designed and constructed vertical MR system. They found little gravitational effect on brain structures, even in the case of a severely atrophied brain. Their vertical system was practical for routine clinical usage and might provide information regarding gravitational effects on regional perfusion and other aspects of brain physiology.

Adult↗
PubMed2001

Asymmetry of parietal lobe activation during piano performance: a high field functional magnetic resonance imaging study.

Functional asymmetry of the parietal lobes during piano performance was assessed utilizing independent component-cross correlation-sequential epoch analysis of functional magnetic resonance imaging time series. Eight right handed musically trained subjects played the piano with their right hand, left hand, or both hands as cued by visually presented musical scores. The areas activated included the posterior parietal cortex (PPC) and the primary sensorimotor areas (SM1). While unilateral SM1 activation was correlated to motion of the corresponding contralateral hand, PPC activation was correlated to piano performance irrespective of hand modality. Furthermore, PPC activation exhibited significant asymmetry, with left hemisphere dominance. The results indicate that the left parietal lobe plays a significant role in the cortical processes of piano performance.

Adult↗
PubMed2001

1H magnetic resonance spectroscopic imaging of permanent focal cerebral ischemia in rat: longitudinal metabolic changes in ischemic core and rim.

The purpose of this study was to determine whether regional differences in metabolites can be seen chronologically in permanent focal cerebral ischemia using 1H magnetic resonance spectroscopic imaging (MRSI), and whether these changes reflect pathological outcome. Regional variation in metabolites after permanent focal ischemia were investigated longitudinally in rats using 1H MRSI for a total of 7 days and then compared to histopathological findings. Four hours after the induction of ischemia, N-acetyl-L-aspartate (NAA) levels in the lateral caudo-putamen and the somatosensory cortex, core ischemic regions, decreased 22 and 40%, respectively. This reduction in NAA was coupled with a marked rise in lactate. In the medial caudo-putamen, the ischemic rim, however, NAA was preserved in spite of a marked increase in lactate. By 24 h post ischemia, the levels of NAA in medial caudo-putamen (ischemic rim in caudate) also decreased significantly. However NAA in cingulated cortex (ischemic rim in cortex) decreased more gradually between 24 and 48 h. This regional difference can reflect the severity of metabolic derangement in the acute stage. After 96 h following ischemia, the levels of all metabolites detected by 1H MRSI had decreased and the levels of NAA decline reflected the severity of histopathological damage. In conclusion, the regional metabolic differences could be assessed by 1H MRSI chronologically, and the depth of NAA decline reflected histopathological changes in the chronic stage.

Animals↗