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Biomedical subjects

S Iida

Publications and source records attributed to S Iida.

At least 109 records · Page 6Linked to original sources
PubMed1999

Temporal changes in mRNA expression for bikunin in the kidneys of rats during calcium oxalate nephrolithiasis.

Inter-alpha-inhibitor and other bikunin-containing proteins are synthesized in relatively large quantities by the liver. These proteins function as Kunitz-type serine protease inhibitors and appear capable of inhibiting calcium oxalate (CaOx) crystallization in vitro. Preliminary studies have shown that renal tubular epithelial cells synthesize bikunin in response to CaOx challenge. To examine this response in vivo, a sensitive reverse transcription-quantitative competitive template-PCR was developed to detect and quantify poly(A)+ -tailed bikunin mRNA expression in kidney tissue from normal rats and rats developing CaOx nephrolithiasis after challenge with ethylene glycol. Bikunin mRNA expression in rat liver tissue was assessed as a positive control. The expression of bikunin mRNA in liver did not differ significantly between normal control rats and experimental rats with induced hyperoxaluria and renal CaOx crystallization. In contrast, there were significant temporal increases in the levels of bikunin mRNA expression in rat kidneys during CaOx nephrolithiasis after challenge with ethylene glycol. Urinary excretion of bikunin-containing proteins seemed to increase concomitantly. These findings indicate an association between the induction of hyperoxaluria/CaOx nephrolithiasis and the expression of the bikunin gene in rat kidneys.

Alpha-Globulins↗
PubMed1999

Chromosomal rearrangement of the PAX-5 locus in lymphoplasmacytic lymphoma with t(9;14)(p13;q32).

B-cell non-Hodgkin's lymphoma (NHL) consists of heterogeneous subtypes based on histologic, immunophenotypic, and clinical findings. Recent advances in molecular biology have provided us new insights into the pathogenesis of this neoplasm at the genetic level, such as the deregulation of the protooncogenes adjoining the immunoglobulin gene (Ig) loci, which is a specific event in mature B-cell tumors. Moreover, involvement of certain protooncogenes corresponds to certain subtypes of NHL. Recently, we found that t(9;14)(p13;q32) chromosomal translocation associated with lymphoplasmacytic lymphoma (LPL) juxtaposes PAX-5 gene encoding for an essential transcription factor (BSAP: B-cell specific activator protein) for B-cell proliferation and differentiation to the Ig heavy chain gene (IgH) locus. This results in deregulated expression of the PAX-5 mRNA. We also developed a diagnostic FISH (fluorescence in situ hybridization) procedure which is able to detect 80% of the widely scattering 9p13 breakpoints involved in this translocation. Thus, an understanding of the PAX-5 gene's physiological role in B-cell development and the pathological role in tumorigenesis may lead to the optimal clinical treatment strategy for LPL and LPL-derived diffuse large cell lymphoma (DLCL).

Animals↗
PubMed1999

Microsatellite instability as a potential marker for poor prognosis in adult T cell leukemia/lymphoma.

Microsatellite instability (MSI) represents a replication error resulting from the dysfunction of mismatch repair gene products. In this study, MSI was analyzed in 18 patients with various subtypes of adult T cell leukemia/lymphoma (ATL/L). Using six different microsatellite loci, we defined MSI as positive when replication errors were observed in at least two loci. The MSI was positive in four cases (22.2%)with acute type ATL, who tended to show more prognostically unfavorable factors and shorter overall survival. These results suggest that genomic instability may be associated with tumor progression rather than the development of ATL/L itself. In addition, the presence of the MSI at initial presentation could appear to warrant consideration as an additional prognostically unfavorable factor.

Adult↗
PubMed1999

Exchangeability of accessory Vif and Vpu proteins between various HIV/SIVs (review).

Representative human and simian immunodeficiency viruses (HIV/SIVs) have been monitored for their Vif and Vpu activities in a wide variety of cells. In contrast to the prototype HIV-1, viruses of the other groups do not necessarily have these activities. Only HIV-2 and SIVmnd were clearly demonstrated to show the Vif and Vpu activities, respectively. The exchangeability of these accessory activities between viruses was then assessed to determine the relatedness of the viruses. Quite different from the results for Tat and Rev trans-activators, the activities are almost fully compatible between viruses. These results may facilitate the functional grouping of various HIV/SIVs.

Gene Products, vif↗
PubMed1999

Rev-dependent expression of three species of HIV-1 mRNAs (review).

The expression of structural and accessory genes of human immunodeficiency virus type 1 (HIV-1) except for nef requires a viral regulatory protein Rev. Rev-dependency of the expression of structural (gag, pol and env), regulatory (tat and rev), and accessory genes (vif, vpr, vpu and nef) has been investigated by various systems, and it has been demonstrated that unspliced (encodes gag and pol) and singly-spliced (env-vpu, vif and vpr) viral mRNAs are differentially dependent on the function of Rev. In this review, the function of HIV-1 Rev in relation to these findings is discussed.

Gene Expression Regulation, Viral↗
PubMed1999

[A case in which palatal squamous cell carcinoma responded to UFT therapy].

We administered UFT to a 70-year-old female with squamous cell carcinoma of the palatal mucosa (T1 N0 M0) who had not consented to radical surgical treatment. The tumor disappeared grossly and histopathologically after 1 month, and no adverse reaction to oral administration of UFT was noted. The patient remains under observation.

Administration, Oral↗
PubMed1999

Multiple myeloma preceding the development of chronic myelogenous leukemia.

A case of a 70-year-old man who first developed multiple myeloma and then chronic myelogenous leukemia (CML) within a 3-year period is documented. The patient, with monoclonal hypergammopathy, was diagnosed with smoldering myeloma with IgG-kappa and Bence Jones protein kappa paraproteinemia. No chemotherapy was given for the myeloma until progressive leukocytosis developed after approximately 3 years. This was found to be due to Philadelphia chromosome positive CML. A reverse transcription-polymerase chain reaction assay did not reveal BCR/ABL mRNAs when the myeloma was first diagnosed. The occurrence of 2 distinct hematologic malignancies in the same patient suggests either a different clonal evolution from a common pluripotent malignant stem cell since the CML stem cell also involves the B-lymphoid lineage, a coincident complication of the 2 hematological malignancies, or the coexistence of 2 distinct malignancies due to the same genetic background and/or exposure to similar carcinogenic agents. The literature provides support for the existence of a relationship between multiple myelomas and CML.

Aged↗
PubMed1999

Infrequent germ-line mutation of the E-cadherin gene in Japanese familial gastric cancer kindreds.

Germ-line mutation of the E-cadherin gene was reported in familial gastric cancer (FGC) kindreds from New Zealand. Therefore, we analyzed all of the exons of E-cadherin by PCR-single-strand conformational polymorphism analysis in 16 patients from 14 Japanese FGC kindreds. However, no germ-line mutation was detected, suggesting that a predisposition to FGCs by E-cadherin gene mutation is infrequent in Japanese cases.

Adolescent↗
PubMed1999

Growth characteristics of T-cell tropic HIV-1 vpu gene mutants in human peripheral blood mononuclear cells.

A mutant designated NL-E65, which lacks the expression of entire vpu gene, was constructed from T-cell tropic wild-type (wt) human immunodeficiency virus type 1 (HIV-1) clone and monitored for its replication property in human cells, along with a mutant NL-Ss which expresses a C-terminal truncated Vpu. The mutant NL-Ss could grow in two cell lines and in all peripheral blood mononuclear cell (PBMC) preparations to some extent, with kinetics similar to those of wt virus. Likewise, the mutant NL-E65 exhibited a replication property typical to the vpu mutant in the two cell lines and in all PBMC cultures, growing at a low level. Along with the results previously reported, these data indicate that HIV-1 Vpu is dispensable for virus replication in any of the types of cells so far tested.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Expression of bikunin mRNA in renal epithelial cells after oxalate exposure.

PURPOSE: To determine the changes in expression of bikunin in renal epithelial cells on exposure to oxalate and calcium oxalate crystals. MATERIALS AND METHODS: This study used reverse transcription polymerase chain reaction (RT-PCR) to examine bikunin mRNA expression levels in MDCK cells exposed to oxalate or calcium oxalate crystals. Poly(A)+ RNA was isolated directly from renal epithelial cells, then converted to cDNA with random primers and reverse transcriptase. To quantify the expression level ofbikunin mRNA, we developed a competitive DNA template for competitive PCR analysis. The PCR products were resolved by electrophoresis on 1.3% agarose gel and visualized with ethidium bromide. In this system, we could quantify the exact number of bikunin mRNA transcripts. Bikunin mRNA from rat liver was expressed as a positive control. RESULTS: Bikunin mRNAs and competitive templates from renal epithelial cells were expressed in all samples as 434 bp and 312 bp bands, respectively. Bikunin expression was significantly increased in oxalate exposed cells. Cells exposed to calcium oxalate monohydrate crystals or latex beads showed no significant change in expression of bikunin. Western blotting analysis also showed increased expression of bikunin and inter-alpha-inhibitor-related proteins in the culture medium of oxalate exposed cells. CONCLUSIONS: These findings suggest that renal epithelial cells express bikunin gene and have the capability to produce bikunin when stimulated by certain agents such as oxalate. This increased expression and production of bikunin may represent a protective response of renal epithelial cells to nephrotoxic challenges of oxalate.

Animals↗
PubMed1999

Molecular detection of heparan sulfate proteoglycan mRNA in rat kidney during calcium oxalate nephrolithiasis.

The present study used reverse transcription (RT)-PCR to examine heparan sulfate proteoglycan (HSPG) mRNA expression in rat kidneys. Total mRNA in kidney was isolated and converted to cDNA. To confirm the exact expression level of HSPG mRNA, quantitative competitive (QC)-PCR was performed for each sample. PCR products were resolved by electrophoresis on 1.5% agarose gel and visualized with ethidium bromide. Fragment intensity and area were measured using an image analyzer. In QC-PCR, target DNA and competitive DNA were expressed, using gene-specific primer for HSPG mRNA, as 506- and 345-bp bands, respectively. The level of HSPG mRNA expression apparently increased in the nephrolithic rat kidney. Immunohistochemical study revealed that increased production of heparan sulfate was detected in both distal and proximal tubules during nephrolithiasis. These findings suggest that increased expression of HSPG may play a significant role during calcium oxalate stone formation.

Animals↗
PubMed1999

Carbohydrate epitopes and mucins expressed by 17 human ovarian carcinoma cell lines.

Ovarian carcinomas are known to be diverse in their histological types and response to therapeutic agents. Specific immunotherapy by the use of mucins or carbohydrate vaccines has been attempted, in which expression of these epitopes by each histotype should clearly be assessed. Seventeen human ovarian carcinoma cell lines were evaluated for their expression of mucin core polypeptide mRNAs (MUC1, MUC2, MUC3, MUC5AC, MUC5B, and MUC6) by the reverse transcription-polymerase chain reaction. They were also examined for their expression of mucin-associated carbohydrate epitopes by flow cytometry. Eleven monoclonal antibodies, including those specific for Lewis antigen-related epitopes and Tn-related epitopes, were used. Expression of the MUC1 gene and sialyl Lewis X was characteristic to all five cell lines derived from clear cell adenocarcinomas. Multiple mucin genes and a diverse range of carbohydrate epitopes were observed with all six cell lines derived from mucinous adenocarcinomas. Mucin-associated carbohydrate epitopes were not detected on three of four serous adenocarcinoma cell lines, although MUC1 and MUC2 mRNAs were detected in all of them. Therefore, ovarian carcinoma cells from tumors of different histological types showed characteristic expression patterns of mucin genes and carbohydrate epitopes.

Adenocarcinoma, Clear Cell↗
PubMed1998

Accessory genes in the darA operon of bacteriophage P1 affect antirestriction function, generalized transduction, head morphogenesis, and host cell lysis.

Bacteriophage P1 mutants with the 8.86-kb region between the invertible C-segment and the residential IS1 element deleted from their genome are still able to grow vegetatively and to lysogenize stably, but they show several phenotypic changes. These include the formation of minute plaques due to delayed cell lysis, the abundant production of small-headed particles, a lack of specific internal head proteins, sensitivity to type I host restriction systems, and altered properties to mediate generalized transduction. In the wild-type P1 genome, the accessory genes encoding the functions responsible for these characters are localized in the darA operon that is transcribed late during phage production. We determined the relevant DNA sequence that is located between the C-segment and the IS1 element and contains the cin gene for C-inversion and the accessory genes in the darA operon. The darA operon carries eight open reading frames that could encode polypeptides containing >100 amino acids. Genetic studies indicate that some of these open reading frames, in particular those residing in the 5' part of the darA operon, are responsible for the phenotypic traits identified. The study may contribute to a better comprehension of phage morphogenesis, of the mobilization of host DNA into phage particles mediating generalized transduction, of the defense against type I restriction systems, and of the control of host lysis.

Bacteriolysis↗
PubMed1998

Multicolor spectral karyotyping identifies new recurring breakpoints and translocations in multiple myeloma.

Karyotypic information on multiple myeloma (MM) is less extensive than that on other myeloid or lymphoid malignancies due to low mitotic activity of plasma cells. An add(14)(q32) marker chromosome has been reported to be the most frequent recurring abnormality in clonally abnormal cases; in approximately one third of the latter cases, this marker has been identified as a der(14)t(11;14)(q13;q32) chromosome. To map chromosomal breakpoints, characterize the add(14)(q32) marker chromosomes, and to identify other recurring translocations in MM, we used spectral karyotyping (SKY) to analyze a panel of nine bone marrow (BM) biopsy samples from eight patients and 10 tumor cell lines derived from MM patients. SKY involves hybridization of 24 fluorescently labeled chromosome painting probes to metaphase spreads in such a manner that simultaneous visualization of each of the chromosomes in a different color is accomplished. By this method, it was possible to define all chromosomal rearrangements and identify all of the clonal marker chromosomes in tumor cells. By detailed mapping of breakpoints of rearrangement, it was also possible to identify several novel recurring sites of breakage that map to the chromosomal bands 3q27, 17q24-25, and 20q11. The partner chromosomes in translocations that generated the add (14)(q32) marker chromosomes were identified in all cases in which they were detected by G-banding (one biopsy and six cell lines). In addition, two new translocations involving band 14q32, ie, t(12;14)(q24;q32) and t(14;20)(q32;q11) have also been identified. These studies demonstrate the power of SKY in resolving the full spectrum of chromosome abnormalities in tumors.

Aged↗
PubMed1998

The HIV-1 Vpr displays strong anti-apoptotic activity.

Mutations in the human immunodeficiency virus type 1 (HIV-1) vpr gene only slightly reduce the replication rate of the virus. To study the role of HIV-1 Vpr in biological effects on cells, HEp-2 cells, which express HIV-1 Vpr constitutively but at a low level, were established. While control HEp-2 cells underwent apoptosis when incubated with sorbitol, the morphological and biochemical apoptotic changes were inefficiently induced in the HIV-1 Vpr-expressing cells by the same treatment. These results clearly indicate that HIV-1 Vpr has anti-apoptotic activity, and raise the possibility that Vpr acts as a weak activator of virus replication through anti-apoptosis.

Animals↗
PubMed1998

Heterologous promoters fused to BCL6 by chromosomal translocations affecting band 3q27 cause its deregulated expression during B-cell differentiation.

The BCL6 gene encodes a POZ/Zinc-finger protein, which acts as a sequence-specific transcriptional repressor. It is expressed in B cells within the germinal centers (GC) and is required for GC formation. In approximately 40% of diffuse large cell lymphomas (DLCL) and approximately 14% of follicular lymphomas (FL), the BCL6 gene is rearranged by chromosomal translocations, which juxtapose heterologous promoters and 5' untranslated sequences derived from other chromosomes to the BCL6 coding domain or by mutations in the 5' regulatory region. To understand the functional consequence of the chromosomal translocations, we have studied the patterns of expression of the promoters found juxtaposed to BCL6 in DLCL and FL during B-lineage differentiation. Distinct heterologous 5' untranslated regions (IGH, IGL, TTF) were identified fused to the BCL6 coding domain by analysis of BCL6 cDNAs in two DLCL cases and one mixed follicular lymphoma (MxFL). These three sequences, as well as three other previously identified BCL6 fusion partners (IGHG3, BOB1, H4), were studied for their pattern of expression during B-lineage differentiation by Northern blot analysis of B-cell lines representation by Northern blot analysis of B-cell lines representative of the pre-B, B, immunoblast, and plasma cell stages. In contrast to BCL6, whose transcription is activated only in B cells within the GC, all of the other sequences displayed a broader pattern of expression ranging from constitutive expression throughout B-cell differentiation to persistent expression in immunoblasts and plasma cells. These results indicate that the expression of BCL6 is deregulated as a consequence of fusion to heterologous promoter regions. The persistent expression of activated BCL6 may contribute to lymphomagenesis by blocking B-cell differentiation within the GC.

B-Lymphocytes↗
PubMed1998

Inhibition of HIV replication by capsid mutant C6b.

A Gag capsid mutant of human immunodeficiency virus type 1 (HIV-1) designated C6b was biologically and biochemically characterized with respect to its ability to suppress the replication of wild-type (wt) HIV. The C6b efficiently interfered with the replication of wt HIV-1 in the cleavage of Gag precursor, and also in the early replication process before or during viral DNA synthesis after viral penetration. The C6b Gag appeared to be unable to form chimeric multimers with HIV-2 Gag and failed to inhibit the replication of wt HIV-2.

Blotting, Southern↗