Search PubMed⌕ Search

Biomedical subjects

T Tajima

Publications and source records attributed to T Tajima.

At least 73 records · Page 4Linked to original sources
PubMed2000

A novel missense mutation in the HMG box region of the SRY gene in a Japanese patient with an XY sex reversal.

The sex-determining region of the Y chromosome, the SRY gene, located on the short arm of the Y chromosome, is appreciated as one of the genes that is responsible for directing the process of sex differentiation. To date, 34 different mutations, including 29 missense and nonsense mutations in the SRY gene, have been described in XY female patients. We investigated the molecular basis of the sex reversal in one Japanese XY female patient by determining the nucleotide sequence of the SRY gene, using polymerase chain reaction and direct sequencing. We identified a novel mutation, of the substitution of Tyr for Asn at nucleotide position 87 (N87Y). This Asn residue is located within the DNA-binding high-mobility-group (HMG) motif, which is considered to be the main functional domain of the SRY protein. Further, this amino acid, Asn, is a conserved residue among mammalian SRY genes. These findings indicate that this amino acid substitution may be responsible for the sex reversal in this patient.

Amino Acid Substitution↗
PubMed2000

Cloning of a cDNA for Xenopus prolactin receptor and its metamorphic expression profile.

A pituitary hormone, prolactin (PRL) shows various effects on cellular metabolism in amphibians, such as stimulation of larval tissue growth and inhibition of metamorphic changes. All these effects are mediated by its cell surface receptor. However, lack of information on PRL receptor (PRL-R) gene expression has made the physiological importance of the PRL/PRL-R system obscure in amphibian metamorphosis. Hence, a Xenopus PRL-R cDNA was cloned, its structure was characterized, and specific binding of PRL to Xenopus PRL-R expressed in COS-7 cells was confirmed. In adult tissues, high level expression was found in the lung, heart, brain, thymus and skin, and low level in the oviduct, kidney and spinal cord. The developmental expression pattern showed that PRL-R messenger ribonucleic acid (mRNA) was expressed in the brain and tail from premetamorphosis and the level increased toward late metamorphosis, suggesting that PRL may inhibit the metamorphic changes in those organs. The level of brain PRL-R mRNA reached a peak just at the start of the metamorphic climax stages and then decreased, whereas in the tail, mRNA expression peaked at late metamorphosis. In the kidney, mRNA expression increased and reached a maximum level at the end of metamorphosis. The results obtained were discussed in relation to metamorphosis.

Amino Acid Sequence↗
PubMed2000

Clinicopathological studies of esophageal carcinosarcoma: analyses of its morphological characteristics using endoscopic, histological, and immunohistochemical procedures.

BACKGROUND AND STUDY AIMS: Carcinosarcoma of the esophagus is a rare malignant neoplasm consisting of both carcinomatous and sarcomatous components, which characteristically forms polypoid tumors. PATIENTS AND METHODS: Seven carcinosarcomas were analyzed using endoscopic, histological, and immunohistochemical procedures. Endoscopically, six of the seven lesions were found to be of the protruding type, while the other one was an ulcerating tumor. RESULTS: In all seven cases, the carcinomatous component consisted of differentiated squamous cell carcinoma, and the sarcomatous component was spindle cell carcinoma. Histological analyses demonstrated that the majority of the protruding tumors consisted of the sarcomatous component, while the ulcerating tumor mainly consisted of squamous cell carcinoma. The Ki-67 (MIB-1) labeling index (LI) of the carcinomatous component (28.2%) did not differ significantly from that of the sarcomatous component (25.5%). The sarcomatous component showed abundant expression of type IV collagen and laminin. CONCLUSIONS: It is conceivable that the carcinomatous and sarcomatous components grow separately from the early stage of the tumors, and that the sarcomatous component forms a protruding tumor mass because it has abundant stroma positive for type IV collagen and laminin.

Aged↗
PubMed2000

Three cases of malignant lymphoma of the breast.

We report three cases of malignant lymphoma (ML) of the breast and discuss diagnosis and management. The first case is a 35-year-old woman who had a left breast tumor. Fine needle aspiration cytology (FNAC) showed ML. Mastectomy was performed without any adjuvant chemotherapy. Histology revealed diffuse large B-cell lymphoma of REAL classification. Seventy one months after surgery, lesions indicating relapse were detected in nodes of the right axilla, mediastinum and para-aorta. She underwent eight cycles of CHOP regimen, but 1 month after the chemotherapy a brain metastasis was detected. The patient then received a high-dose methotrexate regimen with whole-skull irradiation. The second case is a 47-year-old woman who had anterior neck swelling and bilateral breast tumors. Histology of the tumor revealed diffuse large B-cell lymphoma. The patient underwent eight cycles of CHOP regimen and high-dose chemotherapy (HDC) with peripheral blood stem cell transplantation (PBSCT). Forty eight months after the PBSCT, there is no evidence of disease. The third case is a 38-year-old woman who had a right breast tumor. FNAC of the breast tumor showed ML and a CT scan of the chest revealed lymphadenopathy at the crus of the diaphragm. Histology of the tumor revealed low-grade B-cell lymphoma of MALT type. The patient underwent six cycles of CHOP regimen and HDC supported by PBSCT. Eighteen months after the PBSCT, relapse lesions were detected in nodes of the neck, mediastinum and renal hilum. The patient received nine cycles of a THP-COP regimen.

Adult↗
PubMed2000

Prepulse effects on the interaction of intense femtosecond laser pulses with high-Z solids

Kalpha emission of high-Z solid targets irradiated by an intense, short (<100 fs) laser pulse in the 10 keV region is shown to be sensitive to the electron energy cutoff, which is strongly dependent on the density gradient of the plasma corona formed by a long prepulse. The absorption rate of short laser pulses, the hot electron distribution, and x-ray emission from a Cu slab target are studied via a hybrid model, which combines the hydrodynamics, collisional particle-in-cell, and Monte Carlo simulation techniques, and via a direct spectroscopic measurement. An absorption mechanism originating from the interaction of the laser pulse with plasma waves is found to increase the absorption rate by over 30% even for a very short, s-polarized laser pulse. Calculated and measured x-ray spectra are in good agreement, confirming the electron energy cutoff.

Journal Article↗
PubMed2000

Comparison of two recombinant major outer membrane proteins of the human granulocytic ehrlichiosis agent for use in an enzyme-linked immunosorbent assay.

Enzyme-linked immunosorbent assay (ELISA) for human granulocytic ehrlichiosis (HGE) using two different recombinant P44 proteins (rP44 and rP44-2hv) of the HGE agent as antigens was evaluated. Sera from a total of 72 healthy humans both from regions where HGE is nonendemic and regions where HGE is endemic were used as negative controls to determine the cutoff value for ELISA. Sera from a total of 14 patients (nine from whom the HGE agent was isolated and five who were HGE-PCR positive) were used as positive controls. One hundred nine sera from 72 patients in an area where HGE is endemic who were suspected of having HGE were examined by ELISA and indirect immunofluorescence assay (IFA). All IFA-negative sera were negative by both ELISAs. Of 39 sera that were IFA positive, 35 and 27 were positive by ELISA using rP44 and rP44-2hv, respectively, indicating that the use of rP44 is more sensitive. Western blot analysis of the four rP44-ELISA-negative IFA-positive sera using whole HGE agent as antigen suggests that these four sera were false IFA positive. There was no difference in results with or without the preabsorption of sera with Escherichia coli or with or without the cleavage of the fused protein derived from the vector. There was a significant positive correlation between IFA titers and optical densities of ELISAs. Four Ehrlichia chaffeensis-positive and 10 Borrelia burgdorferi-positive sera were negative by ELISA. However, two Babesia microti-positive sera showed strong cross-reactivity to the fused vector protein, which was eliminated after cleavage of the protein. Thus, ELISA using rP44 nonfusion protein would provide a simple, specific, and objective HGE serologic test which can be easily automated.

Bacterial Outer Membrane Proteins↗
PubMed2000

Three novel PHEX gene mutations in Japanese patients with X-linked hypophosphatemic rickets.

X-linked hypophosphatemic rickets (XLH) is an X-linked dominant disorder characterized by renal phosphate wasting, abnormal vitamin D metabolism, and defects of bone mineralization. The phosphate-regulating gene on the X-chromosome (PHEX) that is defective in XLH has been cloned, and its location identified at Xp22.1. It has been recognized to be homologous to certain endopeptidases. So far, a variety of PHEX mutations have been identified mainly in European and North American patients with XLH. To analyze the molecular basis of four unrelated Japanese families with XLH, we determined the nucleotide sequence of the PHEX gene of affected members. We detected a new nonsense mutation (R198X) in exon 5, a new 3 nucleotides insertion mutation in exon 12 and a new missense mutation (L160R) in exon 5 as well as a previously reported nonsense mutation in exon 8 (R291X). These results suggest that: 1) PHEX gene mutations are responsible for XLH in Japanese patients, and 2) PHEX gene mutations are heterogeneous in the Japanese population similarly to other ethnic populations.

Adult↗
PubMed2000

A novel missense mutation of mineralocorticoid receptor gene in one Japanese family with a renal form of pseudohypoaldosteronism type 1.

Pseudohypoaldosteronism type 1 (PHA1) is a rare condition characterized by neonatal salt loss with dehydration, hypotension, hyperkalemia, and metabolic acidosis, despite elevated plasma aldosterone levels and PRA. Two modes of inheritance of PHA1 have been described: an autosomal dominant form and an autosomal recessive form. An autosomal recessive form manifests severe life-long salt wasting resulting from multiple mineralocorticoid target tissue such as sweat, salivary glands, the colonic epithelium, and lung. Contrary, an autosomal dominant PHA1 manifests milder salt wasting that gradually improves with advancing age. Recently, in one sporadic and four dominant cases, four different mutations including two frame shift mutations, two premature termination codons, and one splice site mutation in the mineralocorticoid receptor (MR) gene were identified. We studied the molecular mechanisms of one Japanese family with a renal form of PHA1. PCR and direct sequencing of the MR gene identified a heterozygous point mutation changing codon 924 Leu (CTG) to CCG (Pro) (L924P) in all affected members. COS-1 cells were transfected with expression vectors for either wild type or the mutant MR-L924P receptors, together with the reporter plasmid (glucocorticoid response element tk-CAT). Aldosterone increased CAT activity in cells expressing wild-type receptor, but had no effect in cells expressing the mutant receptors. These results suggest that mineralocorticoid resistance in this family is due to a missense mutation in the MR gene. To our knowledge, this is the first case of the missense mutation of the MR gene in renal PHA1.

Adolescent↗
PubMed2000

Gonadotropin-releasing hormone analog therapy failed to improve predicted final height in two children with central precocious puberty and microcephalus.

Long-acting gonadotropin-releasing hormone (GnRH) analog treatment for central precocious puberty (CPP) suppresses excessive bone maturation by inhibiting the pituitary-gonadal axis, and usually assures favorable results for growth potential. Recently, we encountered two children with CPP and microcephalus in whom GnRH analog therapy arrested pubertal development, but could not suppress bone age maturation effectively. Eventually, their final height deteriorated rather than improved. The reason why these two cases did not respond to GnRH analog therapy remains unknown. However, microcephalus and minor cerebral anomalies may have some links to deterioration of final height. Our cases suggest that careful evaluation will be required especially for CPP with microcephalus throughout treatment with GnRH analog.

Adolescent↗
PubMed2000

CEA immunohistochemical localization is correlated with growth and metastasis of human gallbladder carcinoma.

Carcinoembryonic antigen (CEA) is a good marker of colorectal cancer. Recent studies have demonstrated that CEA may function as a metastatic potentiator by different pathways; i.e., modulation of immune responses, facilitation of intercellular adhesion and cellular migration. However, expression patterns of CEA have not yet been established in human gallbladder carcinomas. In this study, we examined CEA expression in human gallbladder adenocarcinomas and its clinicopathological significance. CEA immunoreactivity was detected not only in the cancer cells (cytoplasmic type: 63.0%, 34/54) but also in the cancer stroma (stromal type: 29.6%, 16/54). According to TNM classification, 75.0% (30/40) of T2-4 gallbladder cancers showed cytoplasmic CEA, while 28.6% (4/14) of the T1 cancers were cytoplasmic CEA-positive (p<0.05). Stromal CEA expression was detected in 40.0% (16/40) and none (0/14) of the T2-4 and T1 cancers, respectively (p<0.05). Lymph node metastasis was frequently found in the cytoplasmic CEA- and stromal CEA-positive gallbladder cancers (44.1% and 62.5%, respectively). These observations suggested that CEA expression plays important roles in cancer cell growth and metastasis of human gallbladder adenocarcinomas.

Adenocarcinoma↗
PubMed2000

DF3 expression in human gallbladder carcinoma: significance for lymphatic invasion.

DF3 (MUC 1) is a member of a family of high molecular weight glycoproteins. Recent studies have demonstrated that DF3 is expressed in tumors of various human organs, and may function as an anti-adhesion molecule that inhibits cell-to-cell adhesion, inducing tumor metastasis. However, expression patterns of DF3 have not yet been established in human gallbladder carcinomas. In this study, we examined DF3 expression in human gallbladder adenocarcinoma and its clinicopathological significance. DF3 immunoreactivity was detected not only in the cancer cells (cytoplasmic type; 50.0%, 27/54) but also in the cancer stroma (stromal type; 46.3%, 25/54). According to TNM classification, 65.0% (26/40) of T2-4 gallbladder cancers showed cytoplasmic DF3, while 7.1% (1/14) of the T1 cancers were cytoplasmic DF3-positive (p<0.001). Stromal DF3 expression was detected in 62.5% (25/40) and none (0/14) of the T2-4 and T1 cancers, respectively (p<0.001). Lymph node metastasis was frequently found in the cytoplasmic DF3- and stromal DF3-positive gallbladder cancers (59.3% and 60.0%, respectively). These observations suggested that DF3 expression plays important roles in cancer cell growth and metastasis of human gallbladder adenocarcinomas.

Adenocarcinoma↗
PubMed2000

[Contrast effects of background stimulus person on attitude similarity judgement and interpersonal attraction: a study of topic familiarity effect].

The purpose of this study was to examine the effects of a background stimulus person on attitude similarity judgement and interpersonal attraction. Mascaro and Graves (1973) argued that a contrast effect on perception of similarity mediated interpersonal attraction. In the present experiment, it was hypothesized that topic familiarity moderated the effects of a background stimulus person on attitude similarity judgement and interpersonal attraction. One hundred twenty-two (122) female students were randomly assigned to four groups, formed by two levels of topic familiarity and two levels of similarity for the background stimulus person. They saw the attitudes of two stimulus persons together, and were asked to rate perceived similarity and interpersonal attraction. Results showed that in familiar topic condition, contrast effect was not found for attitude similarity judgement, but it was found for interpersonal attraction. The finding suggested that presence of a background stimulus person immediately led to the contrast effect on interpersonal attraction.

Adult↗
PubMed2000

Single genotype of measles virus is dominant whereas several genotypes of mumps virus are co-circulating.

We have reported that in Japan measles virus strains have been classified into three distinct different genotypes (C1, D3 and D5) under the new international genotype classification since 1984. Similarly, mumps virus strains have been divided into two genotypes with three subtypes (B1, B2, B3, and D) under the proposed international classification since 1976. To differentiate these genotypes we developed a restriction fragment length polymorphism assay in the hemagglutinin (H) region for measles virus and in the hemagglutinin-neuraminidase (HN) region for mumps virus to facilitate the expanded molecular epidemiology. In the Sapporo 1995/1996 measles outbreak, all 26 strains were classified as D5. Among 32 samples from patients with measles from 1994 to 1997 in Tokyo, 28 were identified as D5 and four were D3; these D3 strains were ascertained as a same hospital acquired infection. Among 45 strains obtained in the Tokyo 1999 outbreak, 38 were D3 and the remaining seven were D5. The dominant genotype of measles in Tokyo has replaced from D5 to D3 similar to the Chicago1/89 strain. We obtained 220 samples from patients with mumps from 1993 to 1997 and they were classified into one strain of B1, 14 strains of B2, 151 strains of B3, and 54 strains of D. Therefore, we suggest that two or three subtypes of mumps virus are co-circulating with a different geographic pattern in genotype distribution, whereas a single measles virus genotype is dominantly observed, showing different epidemiological patterns.

Amino Acid Sequence↗
PubMed2000

Reducing the volume of polyethylene glycol electrolyte lavage solution to less than 2 liters for bowel preparation.

Smaller volumes of polyethylene glycol electrolyte lavage solution (PEG), an oral whole-bowel irrigation solution employed in colorectal preparation, were given to patients to decrease the discomfort associated with pretreatment. Comparison was made between groups receiving standard and modified preparations. A total of 68 patients (gastrointestinal surgery: 55; total colonoscopy: 13) were enrolled in the study. The mean volume of PEG used was significantly smaller in the modified than in the standard preparation (1,694 ml vs. 2,735 ml, p<0.01). In addition, the mean PEG administration period was significantly shorter for the modified preparation (183 min vs. 237 min, p<0.05). However, the mean PEG excretion time and the number of bowel movements were not significantly different between the two groups. There was also no significant difference between the two groups in terms of the efficacy, safety, usefulness, or tolerability of the preparations. These results suggest that it is possible to reduce the PEG volume by more than 1 L to alleviate patient discomfort without a significant loss of efficacy. The modified method is useful for preparing the large bowel for either gastrointestinal surgery or total colonoscopy.

Colonoscopy↗