Conserved regions of the Plasmodium yoelii rhoptry protein RhopH3 revealed by comparison with the P. falciparum homologue.
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Amino Acid Sequence↗
Biomedical subjects
M Tachibana
Publications and source records attributed to M Tachibana.
The high molecular mass rhoptry protein, RhopH1, is encoded by members of the clag multigene family in Plasmodium falciparum and Plasmodium yoelii.
Malarial merozoite rhoptries contain a high molecular mass protein complex called RhopH. RhopH is composed of three polypeptides, RhopH1, RhopH2, and RhopH3, encoded by distinct genes. Using monoclonal antibody-purified protein complex from both Plasmodium falciparum and Plasmodium yoelii, peptides were obtained by digestion of RhopH1 and their sequence determined either by mass spectrometry or Edman degradation. In both species the genes encoding RhopH1 were identified as members of the cytoadherence linked asexual gene (clag) family. In P. falciparum the family members on chromosome 3 were identified as encoding RhopH1. In P. yoelii two related genes were identified and sequenced. One of the genes, pyrhoph1a, was positively identified as encoding RhopH1 by the peptide analysis and the other gene, pyrhoph1a-p, was at least transcribed. Genes in the clag family present in both parasite species have a number of conserved features. The size and location of the P. yoelii protein complex in the rhoptries was confirmed. The first clag gene identified on chromosome 9 was implicated in cytoadherence, the binding of infected erythrocytes to host endothelial cells; this study shows that other members of the family encode merozoite rhoptry proteins, proteins that may be involved in merozoite-erythrocyte interactions. We propose that the family should be renamed as rhoph1/clag.
Amino Acid Sequence↗
A key role of starburst amacrine cells in originating retinal directional selectivity and optokinetic eye movement.
The directional selectivity of retinal ganglion cell responses represents a primitive pattern recognition that operates within a retinal neural circuit. The cellular origin and mechanism of directional selectivity were investigated by selectively eliminating retinal starburst amacrine cells, using immunotoxin-mediated cell targeting techniques. Starburst cell ablation in the adult retina abolished not only directional selectivity of ganglion cell responses but also an optokinetic eye reflex derived by stimulus movement. Starburst cells therefore serve as the key element that discriminates the direction of stimulus movement through integrative synaptic transmission and play a pivotal role in information processing that stabilizes image motion.
Acetylcholine↗
Clinicopathologic factors correlated with number of metastatic lymph nodes in oesophageal cancer.
BACKGROUND: The number of metastatic lymph nodes is applied to the staging system of gastric cancer and colorectal cancer. However, it has not been evaluated in oesophageal cancer. PATIENTS AND METHODS: Of 258 patients with primary squamous cell carcinoma of the thoracic oesophagus between February 1981 and December 1999, 160 underwent three-field oesophagectomy with a curative intent. Clinicopathologic characteristics of those 160 patients were retrospectively investigated according to the number of metastatic lymph nodes. RESULTS: Seventy-eight patients had no lymph node metastases and 82 (51.3%) had lymph node metastases; 51 [31.9%)] had between 1 and 4 positive lymph nodes, and 31 (19.4%) had > or =5. The number of metastatic lymph nodes was significantly correlated with tumour size, macroscopic classification, histological differentiation, pT, pN, and vessel invasions. Multivariate analysis showed that lymph vessel invasion (relative risk 12.6), histological differentiation (relative risk 4.2), and tumour size (relative risk 3.8) were independent factors correlated with number of metastatic lymph nodes. The number of metastatic lymph nodes was also well correlated with the Japanese nodal level and TNM stage, respectively (p<0.001). The 5-year disease-specific survival rate according to the number of positive lymph nodes was 90% for patients without lymph node metastases, 52.2% with 1-4, and 28.9% with > or =5, respectively, p<0. 0001; 0 vs 1-4, p<0.05; 1-4 vs > or =5). CONCLUSION: The number of positive lymph nodes is well correlated with tumour progression and provides a useful prognostic indicator after oesophagectomy for oesophageal cancer.
Aged↗
Selective approaches to gastric cancer patients with liver metastases: role of liver-directed chemotherapy.
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Antineoplastic Combined Chemotherapy Protocols↗
Cochlear melanocytes and MITF signaling.
Melanocytes occur not only in the skin and eyes but in the cochlea, where they exist as intermediate cells of the stria vascularis. Intermediate cells play an important role for cochlear function: Na+K+-ATPase and potassium channels of intermediate cells are essential for production of endocochlear potential and for preparation of ionic milieu in the stria. Consistent with this notion, melanocyte deficiency due to some gene disruptions results in hearing impairment in mice and humans. Mitf/MITF is essential for development and maturation of melanocytes, including strial intermediate cells. Disruption of MITF causes deafness, heterochromia irides, and leucodermia in Waardenburg syndrome type 2 individuals, whereas that of Mitf causes phenotypes of deafness, microphthalmia, and white coat in mice. Again, all of these phenotypes may be explained by a lack of melanocytes. Many signal transduction pathways target the Mitf/MITF gene or Mitf/MITF protein, and disruption of these pathways sometimes results in the phenotype similar to that caused by Mitf/MITF disruption. If not all, certainly many roads lead to MITF in melanocytes.
Animals↗
Transurethral needle ablation of the prostate: an initial Japanese clinical trial.
OBJECTIVES: Transurethral needle ablation of the prostate is a new alternative endoscopic thermal therapy that uses a low-energy radio frequency delivered into the prostatic adenoma. Herein is reported the initial clinical experience by multiple institutes in Japan of transurethral needle ablation of the prostate for the treatment of symptomatic benign prostatic hyperplasia. METHODS: A total of 93 patients were treated with this technique. Transurethral needle ablation of the prostate was generally performed under low-spinal anesthesia. Before and after the procedure, international symptom score (IPSS), quality of life (QOL) score, peak urinary flow rate (Qmax), postvoid residual urine volume and prostate size were evaluated. RESULTS: There was a reduction of IPSS of more than 50% when compared with that of pretreatment, being 51.3% (57/93 patients) and 60.2% (56/93 patients) at 3 months and 6 months after the procedure, respectively. Sixty-seven patients who were available for a 12-month follow-up period demonstrated a markedly decreased mean IPSS when compared with that measured before the treatment for a statistically significant difference (P < 0.01). Fifty-eight patients who were available for uroflowmetric study at 12 months exhibited a notably increased mean Qmax of 11.2 +/- 4.5 mL/s, which was a statistically significant increase when compared with that found before treatment (P < 0.05). Although all patients suffered some degree of gross hematuria after the procedure, none of them required any specific treatment for complications. CONCLUSION: Transurethral needle ablation technique for the treatment of symptomatic benign prostatic hyperplasia is safe and effective. However, a much longer follow-up study is essential for fully evaluating the extended effectiveness of this technique.
Aged↗
Primary signet-ring cell carcinoma of the urinary bladder inducing renal failure.
A case of primary signet-ring cell carcinoma of the urinary bladder that was found to have induced renal failure is the second such case reported in the world. Primary signet-ring cell carcinoma of the urinary bladder is a rare histologic variant of adenocarcinoma. The patient died of distant metastasis 8 months after undergoing total cystectomy. The neoplasm had a high stage at diagnosis, so the prognosis was very poor. To improve the prognosis, earlier diagnosis and establishing a regimen of chemotherapy is necessary.
Carcinoma, Signet Ring Cell↗
M1 prostate cancer with a serum level of prostate-specific antigen less than 10 ng/mL.
BACKGROUND: M1 prostate cancer, which is invasive, is usually associated with a serum level of prostate-specific antigen (PSA) greater than 10 ng/mL, but cases are occurring where the serum PSA level is less than this. The present study investigated the clinical and pathologic characteristics of these cases of M1 prostate cancer. METHODS: Between April 1989 and March 1998, 167 cases of M1 prostate cancer were diagnosed by transrectal needle biopsy and eight of these with a serum PSA level less than 10 ng/mL were investigated. The patients' ages ranged from 57 to 79 years (median, 73) and the serum PSA levels ranged from less than 4.0 to 9.8 ng/mL. In all cases except one, the distal metastasis was to bones only. All cases had received hormonal therapy as the initial therapy. Immunostaining of PSA, chromogranin A, neuron-specific enolase, carcinoembryonic antigen and vimentin were performed in five of the eight cases. RESULTS: Four cases were poorly differentiated, two were undifferentiated, one was a mixture of poorly differentiated and undifferentiated and one case was moderately differentiated. Of the five cases in the immunohistochemical study, three cases with an undifferentiated carcinoma component showed negative staining reactions for PSA and all cases were positive for carcinoembryonic antigen. Four of the patients died of prostate cancer. In two of these four cases, hormonal therapy was ineffective, but systemic chemotherapy and irradiation therapy had been moderately effective. The overall 3-year survival rate was 33.3%. CONCLUSIONS: The cases of M1 prostate cancer with a serum PSA less than 10 ng/mL are almost always poorly differentiated or undifferentiated and have a poor prognosis compared with the usual M1 prostate cancer. Because hormonal therapy is ineffective in these cases, systemic chemotherapy and irradiation therapy should be chosen as the initial therapy.
Aged↗
Re-evaluation of the latent period of bladder cancer in dyestuff-plant workers in Japan.
BACKGROUND: The carcinogenesis of benzidine (BZ) and beta-naphthylamine (BNA) for bladder is well known. Although it was thought to be rare to develop occupational bladder cancer more than 20 years after the exposure to these chemicals, there are still new clinical cases even 30 years after exposure. The purpose of this study was to re-evaluate the latent carcinogenic period of BZ and BNA, in order to set the safety period after exposure for the health surveillance system. METHODS: The subjects were 236 dyestuff-plant workers in Tokyo, who had been exposed to these dyestuffs. The incidence of bladder cancer and its histopathology in this group was surveyed in the period from 1962 to 1996. RESULTS: Nineteen workers (8.1%) were found to have bladder cancers. The exposure period for these 19 patients was 82.0 +/- 50.2 months. The mean +/- SD latent period from the subjects' initial and final exposure until tumor development was 29.5 +/- 8.2 years and 20.1 +/- 10.6 years, respectively. Significantly, a negative correlation (Pearson) was observed between the exposure period and the latent period from the end of exposure to cancer onset (R = -0.544, P < 0.05). All tumors except one were transitional cell carcinoma. Flow cytometric analysis was performed in 11 patients and all of these patients had DNA aneuploidy. CONCLUSIONS: The latent periods of bladder cancer caused by BZ and BNA were longer than previously expected. It is necessary to survey the onset of bladder cancer in exposed workers more than 30 years after the initial exposure.
2-Naphthylamine↗
Expression of sex steroid hormone receptors in human cornea.
PURPOSE: Previously we reported the occurrence of estrogen receptor alpha (ER beta), estrogen receptor beta (ER beta) and androgen receptor (AR) in mouse corneas. The present study was designed to investigate the occurrence of various sex steroid hormone receptors, including ER alpha, progesterone receptor (PR) and AR, in human corneas. METHODS: We used reverse transcription-polymerase chain reaction (RT-PCR) to look for sex hormone receptor mRNAs (ER alpha, PR and AR) in human corneal epithelial cells obtained at autopsy. Next, using an immunocytochemical technique, we localized these receptors in donor human corneas. RESULTS: mRNAs encoding all receptors tested for were found in corneal epithelial cells obtained from male and female donor eyes. Immunocytochemical examination revealed that the receptors were located in the nuclei of corneal epithelial, stromal, and endothelial cells. CONCLUSIONS: Since receptors for both male and female sex hormones are present in human corneas of both genders, we postulate that the receptors may influence the biological functions of corneal cells through direct interaction with specific hormones.
Aged↗
Concurrent expression of angiogenic growth factors and neovascularization during tumourigenesis in colorectal carcinoma patients.
Details of concurrent expression of angiogenic growth factors (AGFs) and microvessel density (MVD) in human colorectal adenomas and carcinomas remain obscure. Eighty lesions, 20 each from colorectal adenoma, Tis, T1 and T2 cancers were evaluated immunohistochemically for basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), thymidine phosphorylase (dThdPase) and MVD. MVD (p = 0.0001) and bFGF expression (p = 0.0001) increased in the order of adenoma, Tis, T1 and T2 cancers. VEGF expression was same in adenomas and cancers while dThdPase was weak in adenomas but strongly expressed in invasive carcinomas ( > T1). MVD had positive correlation with tumour size in small (< or = 4 cm) colorectal cancers. Concurrent expression of AGFs was noticed in invasive carcinomas. bFGF seems to be the strongest among the three AGFs expressed during colorectal carcinogenesis and had a significant correlation with tumour MVD. Concurrent expression of multiple AGFs is a crucial step in the transition from non-invasive to invasive carcinoma.
Adenocarcinoma↗
Characterization of an isoform of rice starch branching enzyme, RBE4, in developing seeds.
cDNA clones encoding an isoform of starch branching enzyme, RBE4, have been identified from a developing rice seed cDNA library, using a synthetic oligonucleotide probe corresponding to the N-terminal amino acid sequence of RBE4. The cDNA-derived amino acid sequence indicated that RBE4 is initially produced as a precursor protein of 841 amino acids, including a 53-residue transit peptide at the N-terminus. The mature form of RBE4 shared a high degree of sequence identity (80%) with mature RBE3, and possessed an N-terminal extra sequence, as found in RBE3. Northern blot analysis demonstrated that the RBE4 gene is expressed in both leaves and developing seeds. The RBE4 gene was distinguished from the RBE1 and RBE3 genes by expression at the earlier stages of seed development. To examine enzymatic functions of RBE4, recombinant proteins were produced in Escherichia coli cells, and purified by two chromatographic separations. The branched alpha-glucans produced by the recombinant enzymes from potato amylose revealed the different patterns of oligosaccharide chain transfer. The peak of major branches of the products by RBE3 or RBE4 was 6 glucose units, whereas the peaks of major branches of the products by RBE1 were 6 and 11 glucose units. The similar property between RBE3 and RBE4 is supported by high similarity of the amino acid sequences between them.
1,4-alpha-Glucan Branching Enzyme↗
Differences in the dynamic cerebrovascular response between stepwise up tilt and down tilt in humans.
We studied dynamic cerebrovascular responses in eight healthy humans during repetitive stepwise upward tilt (SUT) and stepwise downward tilt (SDT) maneuvers between supine and 70 degrees standing at intervals of 60 s. Mean cerebral blood flow velocity (FV(MCA)) was measured at the middle cerebral artery (MCA) with transcranial Doppler ultrasonography. Mean arterial blood pressure (ABP) was measured via the radial artery and adjusted at the level of the MCA (ABP(MCA)). Cerebral critical closing pressure (P(CC)) was estimated from the systolic-diastolic relationship between FV(MCA) and ABP(MCA). ABP(MCA) minus P(CC) was considered the cerebral perfusion pressure (CPP). The tilt maneuvers produced stepwise changes in both CPP and FV(MCA). The FV(MCA) response to SUT was well characterized by a linear second-order model. However, that to SDT presented a biphasic behavior that was described significantly better (P < 0.05) by the addition of a slowly responding component to the second-order model. This difference may reflect both different cardiovascular responses to SUT or SDT and different cerebrovascular autoregulatory behaviors in response to decreases or increases in CPP.
Blood Flow Velocity↗
Modulation of excitatory synaptic transmission by GABA(C) receptor-mediated feedback in the mouse inner retina.
In many vertebrate CNS synapses, the neurotransmitter glutamate activates postsynaptic non-N-methyl-D-aspartate (NMDA) and NMDA receptors. Since their biophysical properties are quite different, the time course of excitatory postsynaptic currents (EPSCs) depends largely on the relative contribution of their activation. To investigate whether the activation of the two receptor subtypes is affected by the synaptic interaction in the inner plexiform layer (IPL) of the mouse retina, we analyzed the properties of the light-evoked responses of ON-cone bipolar cells and ON-transient amacrine cells in a retinal slice preparation. ON-transient amacrine cells were whole cell voltage-clamped, and the glutamatergic synaptic input from bipolar cells was isolated by a cocktail of pharmacological agents (bicuculline, strychnine, curare, and atropine). Direct puff application of NMDA revealed the presence of functional NMDA receptors. However, the light-evoked EPSC was not significantly affected by D(-)-2-amino-5-phosphonopentanoic acid (D-AP5), but suppressed by 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonamide (NBQX) or 1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine hydrochloride (GYKI 52466). These results indicate that the light-evoked EPSC is mediated mainly by AMPA receptors under this condition. Since bipolar cells have GABA(C) receptors at their terminals, it has been suggested that bipolar cells receive feedback inhibition from amacrine cells. Application of (1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid (TPMPA), a specific blocker of GABA(C) receptors, suppressed both the GABA-induced current and the light-evoked feedback inhibition observed in ON-cone bipolar cells and enhanced the light-evoked EPSC of ON-transient amacrine cells. In the presence of TPMPA, the light-evoked EPSC of amacrine cells was composed of AMPA and NMDA receptor-mediated components. Our results suggest that photoresponses of ON-transient amacrine cells in the mouse retina are modified by the activation of presynaptic GABA(C) receptors, which may control the extent of glutamate spillover.
Amacrine Cells↗
Genomic organization and chromosomal mapping of the basic helix-loop-helix factor OUT (Tcf23/TCF23).
The genomic organization of Tcf23, the gene coding for mouse OUT, a basic helix-loop-helix transcription factor, was determined and its chromosome location was assigned to the A3 region of chromosome 5. By in silico searching, we further found the human counterpart of the mouse OUT gene (TCF23) in the draft human genome sequence and assigned it to 2p24-->p23.
Amino Acid Sequence↗
Expression of estrogen receptor (ER-alpha and ER-beta) mRNA in human prostate cancer.
OBJECTIVE: The distribution of the two estrogen receptors (ER-alpha, ER-beta) in human prostate tissue have not been fully clarified, so the present study investigated the mRNA expression of the receptors to explain the broad spectrum of estrogen activity in prostate cancer. MATERIALS AND METHODS: Four human prostate cancer cell lines (LNCap, JCA-1, DU-145 and PC-3) and 24 pairs of untreated prostate cancer tissue and noncancerous tissue from resected prostate glands were subjected to RT-PCR testing. RESULTS: Both LNCap and JCA-1 expressed the mRNA of both receptors, but DU-145 and PC-3 only expressed ER-beta mRNA. In the human prostate tissue samples, 20 of the 24 prostate cancer tissues expressed ER-alpha, and 23 of the 24 expressed ER-beta. Of the 24 noncancer tissues, 14 expressed ER-alpha mRNA and 17 expressed ER-beta mRNA. The incidence of ER-beta mRNA expression between the paired cancer and noncancer tissues was statistically significantly different (p<0.05). CONCLUSIONS: A higher incidence of ER-beta mRNA expression in untreated prostate cancer tissues was observed. Furthermore, the absence of ER-alpha mRNA and the presence of ER-beta mRNA expression in hormone-independent and/or untreated prostate cancer cells leads to a tentative speculation of the mechanism of the hormone refractory feature of prostate cancer.
Estrogen Receptor alpha↗
Expression of metallothionein in colorectal cancers and synchronous liver metastases.
The aim of this study is to clarify whether the expression of metallothionein (MT) is related with the malignant potential in primary colorectal cancer and/or synchronous liver metastasis. Immunohistochemical staining for MT was performed on the specimens of adenocarcinoma of the colon and rectum and its liver metastases in 34 patients treated with curative surgery, respectively. Expression of MT was compared with clinicopathological variables and patient survival. In patients with primary colorectal cancer, positive expression was found in 7 of 34 (20.6%) patients, but MT was not detected in any of the cases of liver metastases (0%; p = 0.0111). In the primary tumor, positive MT expression was significantly associated with a higher degree of lymph node involvement (mean +/- SD: 48.4 +/- 33.8 vs. 18.6 +/- 24.4% in MT-positive and MT-negative tumors, respectively; p = 0.0122). The survival rate in the patients with MT-negative tumors was significantly better than that in those with MT-positive tumors as primary sites (p = 0.0198). MT expression in colorectal cancer may be a potential marker affecting lymph node metastases and may be a predictor of a poor prognosis, particularly in patients with synchronous liver metastases.
Adenocarcinoma↗