Genetic diagnosis: a troublesome method?
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Colorectal Neoplasms↗
Biomedical subjects
K Imai
Publications and source records attributed to K Imai.
Expression of sulfated carbohydrate chain and core peptides of mucin detected by monoclonal antibodies in Barrett's esophagus and esophageal adenocarcinoma.
Columnar epithelium-lined esophagus (Barrett's esophagus) is an acquired disorder associated with a high incidence of adenocarcinoma of the lower esophagus. Columnar epithelium resembling intestinal metaplasia (IM) is especially important, since it is considered to be a premalignant condition. The aim of this study was to define the sulfated carbohydrate chain of mucin and its core peptide profile in Barrett's esophagus (BE) and to compare it with the profile in Barrett's adenocarcinoma and lower esophageal adenocarcinoma. The sulfated carbohydrate chain was not expressed in 16 specimens of normal esophageal epithelium, but in BE, it was expressed in 50% (8/16) of the specimens. This chain was detected in 100% (7/7) of esophageal adenocarcinoma specimens, including four cases of Barrett's adenocarcinoma. These data suggest that the sulfated carbohydrate chain may be associated with malignant phenotype of the esophagus. MUC1 core peptide was positive in 87% (13/15) of BE specimens and in 29% (2/7) of the esophageal adenocarcinoma specimens. MUC2 core peptide was present in 57% (8/14) and 43% (3/7) of these specimens, respectively. These data suggest that Barrett's epithelium, which is similar to IM, but not normal esophageal epithelium, expresses the sulfated sugar chain which is known to be present in gastric IM and colonic mucosa. However, there was no significant correlation between the expression of the sulfated sugar chain and the expression of either mucin core peptide MUC1 or MUC2. Thus, this carbohydrate chain may be expressed on as yet unidentified core proteins, other than MUC1 or MUC2 core peptide, in BE and esophageal adenocarcinoma. Identification of these proteins may be very important in helping to detect premalignant status in BE.
Adenocarcinoma↗
Translocation of the retina for management of subfoveal choroidal neovascularization I: experimental studies in the rabbit eye.
PURPOSE: To report a surgical method for retinal translocation as a potential treatment for eyes with subfoveal choroidal neovascularization. METHODS: Thirty right eyes of 30 pigmented rabbits were used for this study. The first 15 were used to develop the technique. The complete surgical technique for retinal translocation was performed in the last consecutive 15 rabbits. Intravitreal injection of sulfur hexafluoride was performed to compress and liquefy the vitreous. Two weeks later, we used transscleral subretinal hydrodissection to create a retinal detachment. A scleral resection was then performed near the equator in the superotemporal quadrant. Fundus photographs were taken to record the retinal status before, immediately after, and 1, 3, and 7 days after surgery. Electroretinography was performed in three rabbits 3, 7, and 14 days after retinal translocation. Histologic studies were performed in one rabbit 7 days after retinal translocation. RESULTS: Our results are based on experiments performed in the last consecutive 15 rabbits. One day after surgery, retinal reattachment was observed in 14 of the 15 animals. The remaining animal developed endophthalmitis. A predictable retinal translocation of about 1,000 microm was achieved. Retinal tears were noted on the retinal folds in four cases after 1 week. Electroretinographic studies showed transient reduction in retinal function. Mild morphologic damage to the outer retinal layers was seen histologically. Retinal detachment or proliferative vitreoretinopathy did not develop in any rabbit in the 14 days of follow-up. CONCLUSIONS: Limited retinal translocation with repositioning of the central retina was accomplished in rabbits.
Animals↗
Phe-X-Pro-Arg-Leu-NH(2) peptide producing cells in the central nervous system of the silkworm, Bombyx mori.
Members of the neuropeptide family having Phe-X-Pro-Arg-Leu-NH(2) (FXPRLamide; X=Ser, Thr, Val, or Gly) at the C-terminus serve as regulators of oviduct and visceral muscle contraction, sex pheromone production, and diapause induction. Antibody raised against Bombyx mori diapause hormone recognized a variety of FXPRLamide peptides. Using this antibody, the antigen was immunocytochemically localized in the central nervous system (CNS) of the silkworm, Bombyx mori. Immunoreactive somata were observed in all ganglia of the CNS including the brain. Twelve somata localized at the midline of the suboesophageal ganglion (SG) were most intensely stained, and their neurite projections reached the retrocerebral complex. Thus, these cells in the SG exhibited typical features of neuroendocrine neurons. Marked reduction in immunoreactivity was observed in a pair of neurosecretory cells in the labial neuromere in SG of diapause type pupae, which indicates an active release of FXPRLamide peptides from these cells. No clear connection to neurohemal sites were observed in immunoreactive cells in the brain, thoracic or abdominal ganglia, suggesting that the immunoreactive peptides in these organs are likely to serve as neurotransmitters or neuromodulators.
Journal Article↗
Experimental evaluation of hepatic circulation, energy metabolism, and morphologic changes in brain death.
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Adenine Nucleotides↗
A myoglobin evolved from indoleamine 2,3-dioxygenase, a tryptophan-degrading enzyme.
The distribution, isolation, spectral and oxygen-binding properties, stability of ferrous state (autoxidation), amino acid sequence and gene structure of indoleamine 2,3-dioxygenase (IDO)-like myoglobins are summarized, and their evolution is discussed. Although it has long been thought that all hemoglobins and myoglobins have evolved from a common ancestral gene encoding a 14-16 kDa polypeptide, the discovery of IDO-like myoglobin from several gastropod molluscs clearly indicates that there was an alternative pathway for myoglobin evolution.
Amino Acid Sequence↗
Isolated lissencephaly sequence with balanced chromosome translocation involving 17p13.3.
We describe a patient with isolated lissencephaly sequence (ILS) who had a de novo balanced translocation with breakpoint at 8p11.23 and 17p13.3. She developed infantile spasms and had severe developmental delay. There was no apparent deletion of 17p13.3 on fluorescence in situ hybridization (FISH) analysis. The breakpoint was located centromeric to the Miller-Dieker syndrome (MDS) marker (D17S379), and telomeric to the marker D17S1566, which is located centromeric to the LIS1 gene. This is the second reported case of ILS with balanced translocation. It is suspected that the breakpoint of 17p13.3 in this patient is located in the responsible gene for ILS.
Brain↗
A hydrophobic peptide (VAP-peptide) of the silkworm, Bombyx mori: structure, expression and an enhancing function of diapause hormone activity.
We have recently identified a unique lipophilic peptide (VAP-peptide) with diapause egg inducing activity in the silkworm, Bombyx mori (Imai et al., 1996). The cloning and sequencing of cDNA encoding VAP-peptide have demonstrated that the deduced amino acid sequence consisted of 84 amino acid residues, from which the mature VAP-peptide of 68 amino acid residues was released by cleaving a signal sequence. Searches of the GenBank data base revealed no significant sequence similarity to other proteins including diapause hormone (DH). VAP-peptide gene was selectively expressed just before and at adult eclosion in the head and the thorax not in the abdomen. By a Western blot analysis, VAP-peptide was also localized in the head and the thorax of adults. The purified recombinant VAP-peptide could not induce diapause eggs even when injected at a high dose of 10 nmol/pupa. Whereas, injection of a mixture of VAP-peptide and DH clearly decreased a half-maximum dose (ED50 value) and a threshold dose (TD value) of DH, and these values decreased according to increasing molar ratios of VAP-peptide to DH. Thus, the VAP-peptide is concluded to be an endogenous protein acting as a potent enhancer of DH activity through interaction with DH.
Amino Acid Sequence↗
A hydrophobic peptide (VAP-peptide) of the silkworm, Bombyx mori: a unique role for adult activity proposed from gene expression and production at the terminal phase of metamorphosis.
A unique hydrophobic peptide (VAP-peptide) isolated from male adult heads of the silkworm, Bombyx mori, has been shown to act as a synergist to the diapause hormone when administered exogenously. Here, we investigated the true role of the endogenous VAP-peptide on differentiation and development of adult organs in the silkworm. By northern blot analyses, the VAP-peptide gene was shown to be exclusively expressed at the terminal phase of adult development in epithelial tissues, especially in the wing and the thoracic integument. In situ hybridization analysis revealed that the gene was highly expressed in the epidermal cells of the wing vein and the thoracic integument. The stage- and tissue-dependent gene expression were clearly correlated to the accumulation profile of VAP-peptide. In the adult thoracic integument, VAP-peptide was predominantly deposited in the cuticle layer. Affinity chromatography indicated the ability of VAP-peptide to bind to chitin. Based on its expression patterns, localization, and chemical properties, VAP-peptide is conceived to be a structural protein that participates in mechanical strengthening of specific cuticle structures, supporting their physical requirements in the adult life of the silkworm.
Animals↗
Relation of matrilysin messenger RNA expression with invasive activity in human gastric cancer.
Matrilysin is a member of the matrix metalloproteinase gene family which is believed to play an important role in tumor progression. Expression of matrilysin mRNA was examined by reverse transcription-polymerase chain reaction combined with Southern blot analysis in 46 human primary gastric cancers. Overexpression of matrilysin was observed in 28 (61%) of gastric cancer tissues. The positive expression ratio of matrilysin was significantly higher in the gastric cancers of subserosa or beyond it than in those within the submucosal layer. Immunohistochemical study with anti-matrilysin monoclonal antibody revealed that matrilysin was mainly expressed on cancer cells but not or very weakly expressed on other cells. In addition, an activated form of matrilysin detected by zymographic analysis was observed in gastric cancer tissues whereas none was detected in non-cancerous tissues, suggesting that matrilysin may directly and powerfully contribute to the invasion step of human gastric cancer. In order to gain more insight into the relationship of this metalloproteinase to invasive activity, we also modulated the expression of matrilysin in gastric cancer cells by DNA transfection using gastric cancer cell lines. Overexpression of matrilysin rendered the gastric cancer cells more invasive in vitro. Concomitant with clinical investigations, matrilysin may be an important metalloproteinase in the progression of gastric cancer.
Adenocarcinoma↗
Amino acid sequence, spectral, oxygen-binding, and autoxidation properties of indoleamine dioxygenase-like myoglobin from the gastropod mollusc Turbo cornutus.
Myoglobin was isolated from the radular muscle of the archaeogastropod mollusc Turbo cornutus (Turbinidae). This myoglobin is a monomer carrying one protoheme group; the molecular mass was estimated by SDS-PAGE to be about 40 kDa, 2.5 times larger than that of usual myoglobin. The cDNA-derived amino acid sequence of 375 residues was determined, of which 327 residues were identified directly by chemical sequencing of internal peptides. The amino acid sequence of Turbo myoglobin showed no significant homology with any other usual 16-kDa globins, but showed 36% identity with the myoglobin from Sulculus diversicolor (Haliotiidae) and 27% identity with human indoleamine 2,3-dioxygenase, a tryptophan-degrading enzyme containing heme. Thus, the Turbo myoglobin can be counted among the myoglobins which evolved from the same ancestor as that of indoleamine 2,3-dioxygenase. The absorbance ratio of gamma to CT maximum (gamma/CT) of Turbo metmyoglobin was 17.8, indicating that this myoglobin probably possesses a histidine residue near the sixth coordination position of heme iron. The Turbo myoglobin binds oxygen reversibly. Its oxygen equilibrium properties are similar to those of Sulculus myoglobin, giving P50 = 3.5 mm Hg at pH 7.4 and 20 degrees C. The pH dependence of autoxidation of Turbo oxymyoglobin was quite different from that of mammalian myoglobin, suggesting a unique protein folding around the heme cavity of Turbo myoglobin. A kinetic analysis of autoxidation indicates that the amino acid residue with pKa = 5.4 is involved in the reaction. The autoxidation reaction was enhanced markedly at pH 7.6, but not at pH 5.5 and 6.3 in the presence of tryptophan. We suggest that a noncatalytic binding site for tryptophan, in which several dissociation groups with pKa > or = 7.6 are involved, remains in Turbo myoglobin as a relic of molecular evolution.
Amino Acid Sequence↗
Tauroursodeoxycholic acid protects cholestasis in rat reperfused livers: its roles in hepatic calcium mobilization.
Tauroursodeoxycholic acid (TUDCA) is of potential benefit in cholestatic disorders. However, the effect of TUDCA on hepatic ischemia-reperfusion injury is unknown. We studied this subject with particular regard to its roles in hepatic calcium mobilization. Three doses of TUDCA were used with continuous intravenous infusion (1.0, 0.1, and 0.01 micromol/kg body weight/min). At 3 hr after 1 hr of ischemia and reperfusion in 70% rat liver, high-dose TUDCA reduced hepatic reperfused injury according to biochemical and histological findings and significantly increased bile flow after reperfusion. It significantly increased tissue calcium content and serum calcium concentration after reperfusion. Furthermore, it also enhanced biliary calcium concentration and total output during reperfusion. In conclusion, TUDCA has a salutary effect on ischemia-reperfusion injury of the liver. However, it is still unclear how the calcium mobilization induced by TUDCA is associated with the hepatoprotection against ischemia-reperfusion injury.
Animals↗
Suppression of invasive properties of colon cancer cells by a metastasis suppressor KAI1 gene.
KAI1 is a potential metastatic suppressor gene for prostate cancer. We found by Northern blot analysis that six of ten (60%) gastric and colon cancer cell lines exhibited undetectable or very low expression level of KAI1 mRNA. The effects of KAI1 on the adhesion, motility and invasiveness of colon cancer cells was therefore investigated by using two kinds of stable transfectants, i.e., antisense transfectants of BM314 cells whose KAI1 mRNA expression was suppressed by transfer of antisense KAI1 cDNA and sense transfectants of DLD-1 cells with the enhanced KAI1 mRNA by sense cDNA transfer. The following results were obtained: (1) KAI1 gene expression had no significant effect on in vitro cell growth rate of colon cancer BM314 and DLD-1 cells; (2) Cell aggregation assay showed that KAI1 enhanced the Ca++-independent aggregatability of those colon cancer cells; (3) It was revealed by cell motility and invasion assays that KAI1 suppressed both the motility and in vitro invasiveness of those cells and (4) Furthermore, both the binding to fibronectin and the migration on fibronectin-coated plates of those cells were inhibited by KAI1 expression. These suggest that reduced KAI1 gene expression may contribute to the invasiveness and metastatic ability of colon cancer cells.
Antigens, CD↗
Prolonged cell survival enhances peritoneal dissemination of gastric cancer cells.
Bcl-2 and a Bcl-2-binding protein BAG-1 function in protection from apoptosis induced by a variety of stimuli. Deregulated expression of Bcl-2 leads to inhibition of apoptosis and is correlated with development of various cancers. Here, we provide evidence that prolonged cell survival introduced by overproduction of Bcl-2 or BAG-1 strongly enhances peritoneal dissemination of human gastric cancer MKN74 cells. Gene transfer-mediated overexpression of Bcl-2 or BAG-1 led to prolonged cell survival of MKN74 cells against serum-starved apoptosis and anoikis. When the viable transfectants were inoculated into the intraperitoneal cavity of BALB/c nude mice, the Bcl-2-expressing MKN74 cells and the BAG-1-expressing MKN74 cells exhibited strongly enhanced peritoneal dissemination in BALB/c nude mice and whole disseminated tumor weights were increased by 4-fold and 3.3-fold, respectively, compared with the control transfectants. The enhanced peritoneal dissemination of MKN74-Bcl-2 and MKN74-BAG-1 transfectants correlated well with resistance to cell death induced by serum-starvation and anoikis. However, the overexpression of Bcl-2 or BAG-1 caused no significant difference among the transfectants in cell growth rates, either in vitro or in vivo. Taken together, these studies demonstrate that resistance to apoptosis is a crucial factor for development of peritoneal dissemination of human gastric cancer cells.
Adenocarcinoma↗
Preparation and evaluation of new Pirkle type chiral stationary phases with long alkyl chains for the separation of amino acid enantiomers derivatized with NBD-F.
In order to improve the high-performance liquid chromatographic separation of alpha-amino acids derivatized with the fluorogenic reagent 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) on commercially available chiral stationary phases (CSPs) such as SUMICHIRAL OA-2500(S) (CSP 1) and OA-4700 (CSP 3), the preparation of two new CSPs (CSP 2 and CSP 4) having 11-aminoundecanoic acid between the aminopropyl silica gel support and the chiral moiety in CSP 1 and CSP 3 is described. CSP 2 and CSP 4 improved both the mutual and enantiomeric separation of NBD-amino acids compared with CSP 1 and CSP 3. Thus, 17 pairs of NBD-amino acid enantiomers and NBD-glycine were separated on CSP 2 except for six NBD-amino acids (D-Asn, D-Ser, D-Gln, L-Pro, L-Ser and Gly). CSP 2 and CSP 4 also showed better enantiomeric separation of NBD-amino acid esters and amides than CSP 1 and CSP 3. It was considered that the achiral long alkyl chains in the CSPs might form a hydrophobic space which assisted the stereoselective interaction of analytes with the chiral moiety by changing the environment around the chiral moiety. On CSP 1 and CSP 2, NBD-beta-amino acid was also enantiomerically separated.
4-Chloro-7-nitrobenzofurazan↗
Differences between bone marrow and lung endothelial cells.
To elucidate the mechanisms by which hematopoietic progenitor cells selectively lodge in bone marrow, we established endothelial cell lines derived from bone marrow and lung and then examined the transendothelial migration of hematopoietic progenitor cells by using cells was examined by a Transwell migration assay. Hematopoietic progenitor cells transmigrated through bone marrow endothelial cells but not through lung endothelial cells. Transendothelial migration of hematopoietic progenitor cells was inhibited by anti-vascular cell adhesion molecule (VCAM)-1 antibody. These findings suggest that transendothelial migration of hematopoietic progenitor cells is specific for bone marrow endothelial cells and that this difference may play an important role in the selective homing of hematopoietic progenitor cells to bone marrow.
Animals↗
Dysembryoplastic neuroepithelial tumor in the insular cortex. Three dimensional magnetoencephalographic localization of epileptic discharges.
A case of dysembryoplastic neuroepithelial tumor in the left insular cortex manifesting with intractable seizures is presented. The multichannel magnetoencephalography (MEG) localized equivalent current dipoles of epileptic discharges at the cerebral cortex adjacent to the tumor. The total removal of the tumor resulted in complete disappearance of seizures. This case demonstrated that multichannel MEG was useful in the three-dimensional localization of irritative zone in the concealed cortices such as inside the sylvian fissure.
Brain Neoplasms↗
Significance of free to total PSA ratio in men with slightly elevated serum PSA levels: a cooperative study.
BACKGROUND: The ratio of free PSA in total PSA (f/t) has been reported to improve the diagnostic accuracy of prostate cancer in the group with slightly elevated serum PSA values. In Japanese cases, the clinical significance of f/t is still controversial. METHODS: The diagnostic significance of f/t in serum for prostate cancer was evaluated in a cooperative study. A total of 77 cases with prostate cancer and 224 with non-prostate cancer showing less than 20 ng/ml of total PSA were evaluated. RESULTS: Serum total and free PSA values were not affected by storage at 25 degrees C for 2 days. The determination of f/t was useful in the cases with a serum total PSA of 5.1-10 ng/ml; the specificity was 60% with a sensitivity of 90% at an f/t of 0.148. The positive predictive value for diagnosis of prostate cancer also increased to 54% from 34% of that in total PSA alone. In the range of 4.1-10 ng/ml, the cut-off value of f/t was 0.155 for obtaining relatively high specificity; sensitivity was 85% and specificity was 56.5%. CONCLUSIONS: Thus, the determination of f/t was considered to be an effective tool for discriminating the non-prostate cancer cases from those of prostate cancer.
Humans↗