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Biomedical subjects

T Kumagai

Publications and source records attributed to T Kumagai.

At least 19 recordsLinked to original sources
PubMed2006

Psychiatric, somatic, and gastrointestinal disorders, and Helicobacter pylori infection in children with recurrent abdominal pain.

AIMS: To examine the utility of the Rome II criteria in children with recurrent abdominal pain (RAP) and compare them to those who met Apley's criteria and those who met neither criteria. METHODS: Prospective study in general paediatric clinics in Komagane, Japan. Children with abdominal pain were classified into those who met Rome II criteria, those who met Apley's criteria, and those who met neither. RESULTS: A total of 182 children with RAP participated; 45 children met Rome II criteria, 55 met Apley's criteria, and 82 met neither. Children who met Rome II criteria had a significantly higher prevalence of psychiatric and somatic disorders compared to the group met neither (36% v 6%, 22% v 10%, respectively). The overall prevalence of H pylori was 7%; prevalence increased with age from 3% at age < or = 10 to 10% for children >10 years. Children who met Rome II criteria had a significantly higher prevalence of H pylori infection than the reference group (18% v 4%). In a logistic regression model, all the study variables were included in the model specifying first the Rome II criteria group as the independent variable; psychiatric disorders, H pylori infection, and older age group were independent risk factors. CONCLUSIONS: More than half the children suffering from recurrent abdominal pain met neither Apley's nor Rome II criteria. Children who meet Rome II criteria should be evaluated for psychiatric disorders and should be tested for H pylori infection. Despite the overall trend for a fall in the prevalence of H pylori infection among children in Japan, there are subpopulations of sick children where the prevalence of the infection is relatively high.

Abdominal Pain↗
PubMed2006

Altered alpha1-syntrophin expression in myofibers with Duchenne and Fukuyama muscular dystrophies.

Alpha1-syntrophin, a scaffolding adapter and modular protein, is a cytoplasmic component of the dystrophin glycoprotein complex. This study investigated immunohistochemically the expression of alpha1-syntrophin in Duchenne and Fukuyama muscular dystrophies (DMD and FCMD, respectively). Biopsied muscles of five DMD, five FCMD, five normal controls and five disease controls (three myotonic and two facioscapulohumeral dystrophies) were analyzed. Immunoblot analysis showed that anti-alpha1-syntrophin antibody had a decreased reaction in both DMD and FCMD muscle extracts. Biopsied muscle sections and their serial sections were immunostained with rabbit anti-alpha1-syntrophin and rabbit anti-muscle-specific beta-spectrin antibodies, respectively. Immunoreactive patterns of sarcolemma were classified into (i) a continuously positive immunostaining pattern, (ii) a partially positive immunostaining pattern, (iii) a negative immunostaining pattern and (iv) a faint but entire surface positive immunostaining pattern. The group mean percentages of alpha1-syntrophin and beta-spectrin immunonegative myofibers in the DMD group were 39.3% and 10.8%, respectively, while those in the FCMD group were 45.5% and 10.4%, respectively. These values were statistically significant compared with those of disease control and normal control muscles. Thus we found that dystrophin-deficient DMD muscles contained significant numbers of alpha1-syntrophin-positive fibers and significant numbers of alpha1-syntrophin-negative fibers were present in dystrophin-positive muscles of severe muscular dystrophy such as FCMD. Alpha-dystrobrevin immunoreactivity was tested in DMD muscles and appreciable amounts of alpha-dystrobrevin that binds to syntrophin were found in DMD muscle membranes.

Adolescent↗
PubMed2005

A sero-epidemiological survey of gelatin sensitization in young Japanese children during the 1979-1996 period.

Recently, an increasing number of adverse reactions in children inoculated with live attenuated virus vaccines containing gelatin have been reported. However, the distribution, magnitude and rate of gelatin sensitization in the Japanese population have not been established. Here, the purpose was to investigate the distribution of children with positive gelatin immunoglobulin G (IgG) and/or IgE in Japan and to ascertain whether the incidence of positive antigelatin antibody cases among the general population, as reflected in the sample employed here, has been increasing during the period in question. The presence of IgE and IgG antibodies were measured against gelatin in 1600 panel sera collected from different age groups of Japanese children in Hokkaido/Sapporo from 1979 through 1996. Among the subjects, 39 had gelatin IgG- and/or IgE-positive sera, and these were correlated with the time of obtaining the sera as well as with the age of the subjects. The older the subject and the later the period, the higher the sero-incidence. Japanese children have become increasingly sensitized to gelatin, especially since the mid-1990s.

Child, Preschool↗
PubMed2004

Human Kluver-Bucy syndrome following acute subdural haematoma.

We present a rare case of complete human Kluver-Bucy syndrome (KBS) following recovery from transtentorial herniation caused by acute subdural haematoma (ASDH). A 17-year-old right-handed high school boy got into stupor within five minutes after 3-rounds of sparing at boxing. Emergency computed tomographic (CT) scan showed right cerebral hemispheric ASDH, which was evacuated following intentional decompressive craniectomy. After recovery of consciousness, he developed emotional changes (placidity with loss of normal fear and anger), psychic blindness, aberrant sexual behaviour, excessive oral tendencies, increased appetite, and hypermetamorphosis in order of mention, which were observed with waxing and waning from 17th to 28th hospital day. Peri-operative CT scaning and magnetic resonance imaging showed lesions of the right temporal lobe and right-dominant orbitofrontal regions including bilateral rectal and medial orbital gyri, and the intact left temporal lobe. Two pathogeneses can be thought of and the whole picture of KBS following ASDH can arise even though one (left in this case) temporal lobe is preserved, 1) in which associated orbitofrontal lesions of the frontal lobes may correlate with occurrence of KBS, or 2) cerebral blood hypoperfusion of both temporal lobes due to increased intracranial pressure and/or compression of both posterior cerebral arteries at the edge of the tentorium cerebelli occurs.

Adolescent↗
PubMed2004

Ruptured de novo intracranial aneurysms.

OBJECTIVE: We describe the actual state of ruptured de novo intracranial aneurysms to contribute to a guideline of follow-up for the patients with treated intracranial aneurysm. METHODS: The authors retrospectively investigated 12 cases drawn from 483 consecutive cases of aneurysmal subarachnoid hemorrhage at our institute over a period of 22 years, in which a previously undemonstrated (hence "de novo") intracranial saccular aneurysm formed and ruptured after successful treatment of a prior aneurysm. FINDINGS: The 12 cases constitute 2.5% of the 483 patients who left our hospital alive. Eleven cases were females and one was a male with a mean age of 55.7 years (range 29-75) at the first subarachnoid haemorrhage (SAH) and an interval between the first and the second rupture of 10.7 years (range: 2.6-23.8, standard deviation: 6.86, 95% confidence interval: 6.39-15.1). Four cases did not have risk factors such as hypertension, family history, smoking, multiple aneurysms, and moyamoya disease. None of these ruptured de novo aneurysms was at the same location as the original lesion. One-third (4 cases) of the de novo lesions in our series were found on the opposite side to each prior lesion. INTERPRETATION: For not only young but also elder patients with a treated aneurysm (from the fifth decade to the sixth), especially for women, late angiography or alternative modalities of less-invasive examination should be considered. To detect de novo intracranial aneurysms before rupture, the search for a de novo aneurysm should be performed within 6.39 years after a previous examination that shows an aneurysm to be nonexistent, in view of the 95% confidence interval of the mean time to de novo aneurysmal rupture (6.39-15.1 years). If applied this survey, 75% (8 cases of 12 cases) of our de novo aneurysms would be detected before rupture.

Adult↗
PubMed2003

Altered aquaporin 4 expression in muscles of Fukuyama-type congenital muscular dystrophy.

This study was undertaken to investigate the expression of aquaporin 4 (AQP4) in the muscle plasma membrane of children with Fukuyama-type congenital muscular dystrophy (FCMD) at protein and mRNA levels. The biopsied six muscles with FCMD, six histochemically normal muscles and eight disease control muscles were analyzed by means of immunoblots, immunohistochemistry and reverse-transcription polymerase chain reaction (RT-PCR). Immunoblots showed that the band of FCMD muscle extracts stained with anti-AQP4 antibody was faint in comparison with that of normal muscle extracts. The immunohistochemistry revealed that most of the FCMD myofibers showed negative immunostaining with anti-AQP4 antibody, although the partially positive immunostaining of sporadic FCMD myofibers was noted. The immunoreactivity was positive with anti-dystrophin and anti-beta-spectrin antibodies in almost all FCMD myofibers. The quantitative RT-PCR demonstrated that the AQP4 mRNA level of the FCMD muscles was markedly reduced. On the basis of these findings, we conclude that the expression of AQP4 in FCMD myofibers is reduced and the reduced content of AQP4 mRNA in FCMD muscles may be related to the decreased expression of AQP4 at the muscle plasma membrane of FCMD myofibers.

Aquaporin 4↗
PubMed2003

Mapping of quantitative trait loci associated with ultraviolet-B resistance in rice (Oryza sativa L.).

The detection of quantitative trait loci (QTLs) associated with UV-B resistance in rice should allow their practical application in breeding for such a complex trait, and may lead to the identification of gene characteristics and functions. Considerable variation in UV-B resistance exists within cultivated rice (Oryza sativa L.), but its detailed genetic control mechanism has not been well elucidated. We detected putative QTLs associated with the resistance to enhanced UV-B radiation in rice, using 98 BC(1)F(5) (backcross inbred lines; BILs) derived from a cross between Nipponbare (a resistant japonica rice variety) and Kasalath (a sensitive indica rice variety). We used 245 RFLP markers to construct a framework linkage map. BILs and both parents were grown under visible light with or without supplemental UV-B radiation in a growth chamber. In order to evaluate UV-B resistance, we used the relative fresh weight of aerial parts (RFW) and the relative chlorophyll content of leaf blades (RCC). The BIL population exhibited a wide range of variation in RFW and RCC. Using composite interval mapping with a LOD threshold of 2.9, three putative QTLs associated with both RFW and RCC were detected on chromosomes 1, 3 and 10. Nipponbare alleles at the QTLs on chromosome 1 and 10 increased the RFW and RCC, while the Kasalath allele at the QTL on chromosome 3 increased both traits. Furthermore, the existence of both QTLs on chromosomes 1 and 10 for UV-B resistance was confirmed using chromosome segment substitution lines. Plants with Kasalath alleles at the QTL on chromosome 10 were more sensitive to UV-B radiation than plants with them on chromosome 1. These results also provide the information not only for the improvement of UV-B resistance in rice though marker-associated selection, but also for the identification of UV-B resistance mechanisms by using near-isogenic lines.

Chromosome Mapping↗
PubMed2003

A gene for a Class II DNA photolyase from Oryza sativa: cloning of the cDNA by dilution-amplification.

Ultraviolet radiation induces the formation of two classes of photoproducts in DNA-the cyclobutane pyrimidine dimer (CPD) and the pyrimidine [6-4] pyrimidone photoproduct (6-4 product). Many organisms produce enzymes, termed photolyases, which specifically bind to these lesions and split them via a UV-A/blue light-dependent mechanism, thereby reversing the damage. These photolyases are specific for either CPDs or 6-4 products. Two classes of photolyases (class I and class II) repair CPDs. A gene that encodes a protein with class II CPD photolyase activity in vitro has been cloned from several plants including Arabidopsis thaliana, Cucumis sativus and Chlamydomonas reinhardtii. We report here the isolation of a homolog of this gene from rice (Oryza sativa), which was cloned on the basis of sequence similarity and PCR-based dilution-amplification. The cDNA comprises a very GC-rich (75%) 5; region, while the 3; portion has a GC content of 50%. This gene encodes a protein with CPD photolyase activity when expressed in E. coli. The CPD photolyase gene encodes at least two types of mRNA, formed by alternative splicing of exon 5. One of the mRNAs encodes an ORF for 506 amino acid residues, while the other is predicted to code for 364 amino acid residues. The two RNAs occur in about equal amounts in O. sativa cells.

Amino Acid Sequence↗
PubMed2003

Secreted adhesion molecules of Strongyloides venezuelensis are produced by oesophageal glands and are components of the wall of tunnels constructed by adult worms in the host intestinal mucosa.

The parasitic female of Strongyloides venezuelensis keeps invading the epithelial layer of the host intestinal mucosa. Upon invasion, it adheres to the surface of the intestinal epithelial cells with adhesion molecules secreted from the mouth. It has been demonstrated that S. venezuelensis are expelled from the intestine because mucosal mast cells inhibit the attachment of adult worms to the mucosal surface. In the present study, we generated specific antibodies against secreted adhesion molecules to investigate their function in vivo, because these molecules have been demonstrated only in vitro in spite of the importance in the infection processes. A mouse monoclonal antibody specific to S. venezuelensis adhesion molecules inhibited the attachment of adult worms to plastic dishes and the binding of adhesion molecules to rat intestinal epithelial cells. Immunohistochemical study revealed that adhesion molecules were produced by oesophageal glands and were continuously secreted in vivo to line the wall of the tunnels formed by adult worms in the intestinal mucosa. Our findings indicate that adhesion molecules play essential roles in the infection processes of S. venezuelensis in the host intestine.

Animals↗
PubMed2003

Nested PCR for detection of mutans streptococci in dental plaque.

AIMS: Mutans streptococci such as Streptococcus mutans and Streptococcus sobrinus have been implicated in human dental caries. In an attempt to develop a rapid and sensitive method for detecting Strep. mutans and Strep. sobrinus in dental plaque, a nested PCR amplification based on the 16S rRNA gene was employed. METHODS AND RESULTS: A universal set of PCR primers for bacterial 16S rRNA gene was introduced for the first PCR, and then two sets of primers specific for the 16S rRNA gene sequences of either Strep. mutans or Strep. sobrinus were used for the second PCR. Eighteen plaque samples were analyzed, and a nested PCR was shown to be more sensitive for detecting Strep. mutans and Strep. sobrinus than direct PCR. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: The 16S rRNA gene-based nested PCR method is a rapid and sensitive method for the detection of mutans streptococci, and may also be suitable for carrying out large-scale studies on the cariogenicity of mutans streptococci.

Adult↗
PubMed2003

Duodenogastric reflux and Helicobacter pylori infection synergistically increase gastric mucosal cell proliferative activity in Mongolian gerbils.

BACKGROUND: Helicobacter pylori and duodenogastric reflux (DGR) are both recognized as aetiological factors in chronic gastritis and gastric carcinogenesis. In this study, a Mongolian gerbil (MG) model was used to investigate the histopathological changes in the gastric mucosa resulting from DGR and/or H. pylori infection. METHODS: One-hundred-and-eleven 7-week-old, specific-pathogen-free, male MGs were divided into four groups: normal controls, gerbils with surgically induced DGR, and H. pylori-infected gerbils with and without DGR. Gerbils were killed 4, 12 and 26 weeks after DGR surgery, their stomachs removed and sections prepared. Sections were fixed immediately in 20% phosphate-buffered formalin and subjected to haematoxylin and eosin staining, Alcian blue at pH 2.5/periodic acid-Schiff staining, and immunostaining for smooth muscle cells, H. pylori and 5'-bromo-2'-deoxyuridine (BrdU). RESULTS: The gastric mucosa of H. pylori-infected gerbils showed chronic active gastritis irrespective of DGR throughout the experimental period. The gastric mucosa of H. pylori-infected gerbils with DGR demonstrated higher BrdU labelling than in the other groups. CONCLUSIONS: In MGs, DGR and H. pylori infection synergistically increased gastric mucosal cell proliferative activity. DGR and H. pylori infection may be involved synergistically in gastric carcinogenesis by increasing cell proliferative activity.

Animals↗
PubMed2002

Gelatin-specific cellular immune responses persist for more than 3 years after priming with gelatin containing DTaP vaccine.

BACKGROUND: Gelatin-specific cell-mediated immunity develops in subjects inoculated with gelatin containing DTaP vaccine. However, it is not yet known whether such established sensitization to gelatin disappears or persists with time. OBJECTIVE: The aim of this study was to follow the patients with gelatin sensitization elicited by DTaP vaccination for their lymphocyte responsiveness and IgE, IgG antibody specific to gelatin over several years and to compare the activities with those at the time of enrollment into the study. METHODS: We studied 28 subjects who developed positive lymphocyte proliferation test (LPT) after receiving gelatin containing DTaP vaccine and eight subjects who had a negative LPT after inoculation of non-gelatin DTaP. Determination of IgE, IgG antibodies and specific lymphoproliferative response directed against gelatin were performed at enrollment and on follow up. RESULTS: None of the subjects had antibody to gelatin at enrollment and none developed gelatin IgE or IgG during follow-up. There was no significant difference in the SIs of the subjects receiving gelatin DTaP (P = 0.150, 95% CI, -0.198-0.032), whereas lymphocyte activity to gelatin increased between enrollment and follow-up in the subjects with non-gelatin DTaP (P = 0.011, 95% CI, 0.063-0.338). CONCLUSION: Gelatin-specific lymphocyte activity persists at comparable levels for more than 3 years in subjects who acquire a positive LPT response to gelatin after receiving primary DTaP vaccine containing gelatin. Furthermore, five out of eight subjects initially with negative LPT to gelatin have been shown to acquire specific LPT with time.

Diphtheria-Tetanus-acellular Pertussis Vaccines↗
PubMed2002

Induction of cytochrome P4501A1 by autoclavable culture medium change in HepG2 cells.

1. Without the addition of xenobiotics, only by changing the culture medium can one induce extensively and transiently cytochrome P4501A1 (CYP1A1) protein and mRNA in human hepatoma HepG2 cells. The induction was aryl hydrocarbon receptor (AhR)-dependent, and was proven by: (1) the medium change activated the AhR, as judged by a electrophoretic mobility shift assay; and (2) the AhR inhibitor alpha-naphthoflavone inhibited the medium change-mediated induction. 2. Induction of CYP1A1 was related to medium prepared by autoclaving. By screening the ingredients in the medium, the serum had no effect on CYP1A1 induction, whereas both photo-oxidized and autoclaved tryptophan were shown to induce CYP1A1, as indicated by CYP1A1 protein or ethoxyresorufin-O-deethylase activity. The autoclaved tryptophan contained in an autoclavable medium was a more potent inducer of CYP1A1 than photo-oxidized tryptophan. 3. The results provide some practical suggestions with experiments related to CYP1A1.

Cell Line↗
PubMed2001

Oxidized low-density lipoprotein-binding specificity of Asp-hemolysin from Aspergillus fumigatus.

Oxidized low-density lipoprotein (Ox-LDL) is known to be involved in the generation and progression of atherosclerosis. Ox-LDL has a number of potentially atherogenic effects on vascular cells, including the uncontrolled uptake by scavenger receptors. We have previously shown that Asp-hemolysin binds to Ox-LDL in a concentration-dependent manner. The present study was undertaken to clarify the binding specificity of Asp-hemolysin to Ox-LDL. We examined the binding specificity of Asp-hemolysin to Ox-LDL using several modified lipoproteins and scavenger receptor ligands. Asp-hemolysin bound to Ox-LDL with shorter LDL oxidation times. However, Asp-hemolysin did not bind to the acetylated LDL. The native high-density lipoprotein (n-HDL) and modified HDL (e.g., acetylated HDL, oxidized HDL) also had no Asp-hemolysin binding. Furthermore, inhibitors of the scavenger receptor binding, including maleylated BSA, polyinosinic acid, dextran sulfate and fucoidin, had no effect on the binding of Ox-LDL to Asp-hemolysin. Surface plasmon resonance studies revealed that Ox-LDL binds with high affinity (K(D)=0.63 microg/ml) to Asp-hemolysin. We concluded that Asp-hemolysin is a specific binding protein with a high affinity for Ox-LDL, and its binding specificity is distinct from any receptor for Ox-LDL. The present studies suggest that Asp-hemolysin may bind to Ox-LDL using a mechanism different from the scavenger receptors.

Aspergillus fumigatus↗
PubMed2001

Neuroprotective effect of riluzole in MPTP-treated mice.

The neuroprotective effects of riluzole, a Na(+) channel blocker with antiglutamatergic activity, and MK-801, a blocker of N-methyl-D-aspartate (NMDA) receptors, were compared in the model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced depletion of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels in mice. The mice were injected intraperitoneally (i.p.) with four administrations of MPTP (10 mg/kg) at 1 h intervals and then the brains were analyzed 1, 3 and 7 days after the treatment. Dopamine and DOPAC levels were significantly decreased in the striatum from 1 day after MPTP treatment. A severe depletion in dopamine and DOPAC levels was found in the striatum 3 and 7 days after MPTP treatment. Riluzole antagonized the MPTP-induced decrease in dopamine, DOPAC and HVA levels in the striatum. On the other hand, MK-801 prevented the MPTP-induced decrease in DOPAC levels, but not in dopamine levels in the striatum. An immunohistochemical study indicated that riluzole can protect against MPTP-induced neuronal damage in the substantia nigra. These results suggest that riluzole is effective against MPTP-induced neurodegeneration of the nigrostriatal dopaminergic neuronal pathway.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗