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2.
Epidemiol Psychiatr Sci ; 27(2): 146-156, 2018 Apr.
Article in English | MEDLINE | ID: mdl-27866510

ABSTRACT

AIMS: For nearly a century, the incidence of cancer in people with schizophrenia was lower than in the general population. In the recent decade, the relationship between cancer and schizophrenia has become obscured. Thus, we investigated the cancer risk among young and middle-aged patients with schizophrenia. METHODS: Records of newly admitted patients with schizophrenia (n = 32 731) from January 2000 through December 2008 were retrieved from the Psychiatric Inpatient Medical Claims database in Taiwan, and the first psychiatric admission of each patient during the same period was defined as the baseline. We obtained 514 incident cancer cases that were monitored until December 2010. Standardised incidence ratios (SIRs) were calculated to compare the risk of cancer between those with schizophrenia and the general population. Stratified analyses of cancer incidences were performed by gender, site of cancers and duration since baseline (first psychiatric admission). RESULTS: The incidence of cancer for all sites was slightly higher than that of the general population for the period (SIR = 1.15 [95% CI 1.06-1.26], p = 0.001). Men had a significantly higher incidence of colorectal cancer (SIR = 1.48 [95% CI 1.06-2.06], p = 0.019). Women had a higher incidence of breast cancer (SIR = 1.47 [95% CI 1.22-1.78], p < 0.001). Intriguingly, the risk for colorectal cancer was more pronounced 5 years after the first psychiatric admission rather than earlier (SIR = 1.94 [1.36-2.75], p < 0.001) and so was the risk for breast cancer (SIR = 1.85 [1.38-2.48], p < 0.001). The cancer incidence was higher in patients with schizophrenia contradicting the belief that schizophrenia was protective of cancers. CONCLUSIONS: Our analyses suggest that men and women with schizophrenia were more vulnerable to certain types of cancers, which indicates the need for gender-specific cancer screening programs. The fact that risk of colorectal cancer was more pronounced 5 years after the first psychiatric admission could imply the impact of unhealthy lifestyles or the possibility of delayed diagnoses.


Subject(s)
Neoplasms/epidemiology , Schizophrenia/complications , Adolescent , Adult , Age Distribution , Breast Neoplasms/epidemiology , Cohort Studies , Colorectal Neoplasms/epidemiology , Databases, Factual , Female , Humans , Incidence , Male , Middle Aged , Risk Factors , Schizophrenia/epidemiology , Sex Distribution , Taiwan/epidemiology , Young Adult
3.
Dis Esophagus ; 29(4): 392-9, 2016 May.
Article in English | MEDLINE | ID: mdl-25715747

ABSTRACT

Esophagitis is the second most common gastrointestinal manifestation of cytomegalovirus (CMV) infection after colitis. CMV esophagitis has been reported in patients who have undergone transplantation, are on long-term renal dialysis, or who have the human immunodeficiency virus infection. This study aimed to investigate the clinical characteristics and manifestations of CMV esophagitis in patients who underwent diagnostic endoscopy. A total of 16 patients with histologically proven CMV infection were identified from 1539 patients with esophageal ulcers and analyzed retrospectively (January 2006 to December 2013). Patients' personal data (age, smoking, and alcohol consumption), underlying systemic diseases (diabetes mellitus, end-stage renal disease, and chronic obstructive pulmonary disease), malignancy, indication for esophagogastroduodenoscopy, endoscopic characteristics, and diagnostic methods (pathological or serological findings) were collected for further analysis. Among the patients with CMV esophagitis, the mean age was 59.94 years (range, 23-84 years). The male : female ratio was 1.67:1. Odynophagia and epigastralgia were common symptoms. Of the 16 patients, 3 (18.75%) were infected with the human immunodeficiency virus and 9 (56.25%) had an underlying malignancy, including lung cancer (6 patients), esophageal cancer (2 patients), gastric cancer (1 patient), ampulla of Vater cancer (1 patient), and lymphoma (1 patient). Six of the 9 patients (66.7%) with malignancy had been administered concurrent chemoradiotherapy (CCRT). In this study, patients with malignancy who had been administered CCRT were at increased risk for CMV esophagitis, which had not been reported before in the literature. CMV esophagitis should be considered as a potential treatment-related complication of CCRT.


Subject(s)
Chemoradiotherapy/adverse effects , Cytomegalovirus Infections , Esophagitis , HIV Infections/epidemiology , Neoplasms , Cytomegalovirus Infections/complications , Cytomegalovirus Infections/diagnosis , Cytomegalovirus Infections/epidemiology , Cytomegalovirus Infections/physiopathology , Endoscopy, Digestive System/methods , Esophagitis/diagnosis , Esophagitis/epidemiology , Esophagitis/physiopathology , Esophagitis/virology , Female , Humans , Male , Middle Aged , Neoplasms/epidemiology , Neoplasms/therapy , Retrospective Studies , Risk Factors , Symptom Assessment/methods , Taiwan/epidemiology
4.
Br J Cancer ; 110(3): 602-8, 2014 Feb 04.
Article in English | MEDLINE | ID: mdl-24292447

ABSTRACT

BACKGROUND: This study evaluated the efficacy and safety of ziv-aflibercept in combination with cisplatin and pemetrexed in non-small cell lung cancer (NSCLC). METHODS: This single arm, multicentre phase II trial enrolled patients with previously untreated, locally advanced or metastatic non-squamous NSCLC. Patients received intravenous ziv-aflibercept 6 mg kg(-1), pemetrexed 500 mg m(-2), and cisplatin 75 mg m(-2), every 21 days for up to six cycles. Maintenance administration of ziv-aflibercept was to continue until disease progression, intolerable toxicity or other cause for withdrawal. The co-primary end points were objective response rate (ORR) and progression-free survival (PFS). Planned sample size was 72 patients. RESULTS: The study was closed prematurely because of three confirmed and two suspected cases of reversible posterior leukoencephalopathy syndrome (RPLS). A total of 42 patients were enrolled. Median age was 61.5 years; 55% were male, 86% Caucasian and 50% had Eastern Cooperative Oncology Group performance status (ECOG PS)=0. A median of four cycles of ziv-aflibercept was administered. The most common treatment-emergent adverse events (TEAEs) of any grade were nausea (69%) and fatigue (67%), with hypertension (36%) as the most common grade 3/4 TEAE. Of the 38 evaluable patients, ORR was 26% and median PFS was 5 months. CONCLUSION: Cases of RPLS had been observed in other studies in the ziv-aflibercept clinical development programme but the rate observed in this study was higher than previously observed. This might be related to declining renal function and/or hypertension. Although ORR and PFS were in accordance with most historical first-line NSCLC studies, this combination of ziv-aflibercept/cisplatin/pemetrexed will not be further explored in NSCLC.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Carcinoma, Non-Small-Cell Lung/drug therapy , Cisplatin/administration & dosage , Glutamates/administration & dosage , Guanine/analogs & derivatives , Receptors, Vascular Endothelial Growth Factor/administration & dosage , Recombinant Fusion Proteins/administration & dosage , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Carcinoma, Non-Small-Cell Lung/mortality , Carcinoma, Non-Small-Cell Lung/pathology , Cisplatin/adverse effects , Disease-Free Survival , Drug-Related Side Effects and Adverse Reactions/classification , Drug-Related Side Effects and Adverse Reactions/pathology , Female , Glutamates/adverse effects , Guanine/administration & dosage , Guanine/adverse effects , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Pemetrexed , Receptors, Vascular Endothelial Growth Factor/adverse effects , Recombinant Fusion Proteins/adverse effects , Treatment Outcome
5.
Cell Microbiol ; 15(1): 82-97, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22985085

ABSTRACT

Enterohaemorrhagic Escherichia coli (EHEC) causes life-threatening infections in humans as a consequence of the production of Shiga-like toxins. Lack of a good animal model system currently hinders in vivo study of EHEC virulence by systematic genetic methods. Here we applied the genetically tractable animal, Caenorhabditis elegans, as a surrogate host to study the virulence of EHEC as well as the host immunity to this human pathogen. Our results show that E. coli O157:H7, a serotype of EHEC, infects and kills C. elegans. Bacterial colonization and induction of the characteristic attaching and effacing (A/E) lesions in the intact intestinal epithelium of C. elegans by E. coli O157:H7 were concomitantly demonstrated in vivo. Genetic analysis indicated that the Shiga-like toxin 1 (Stx1) of E. coli O157:H7 is a virulence factor in C. elegans and is required for full toxicity. Moreover, the C. elegans p38 mitogen-activated protein kinase (MAPK) pathway, an evolutionarily conserved innate immune and stress response signalling pathway, is activated in the regulation of host susceptibility to EHEC infection in a Stx1-dependent manner. Our results validate the EHEC-C. elegans interaction as suitable for future comprehensive genetic screens for both novel bacterial and host factors involved in the pathogenesis of EHEC infection.


Subject(s)
Caenorhabditis elegans/enzymology , Caenorhabditis elegans/microbiology , Escherichia coli O157/pathogenicity , Host-Pathogen Interactions , Shiga Toxin 1/metabolism , Virulence Factors/metabolism , p38 Mitogen-Activated Protein Kinases/biosynthesis , Animals , Caenorhabditis elegans/immunology , Escherichia coli Infections , Intestinal Mucosa/microbiology , Intestinal Mucosa/pathology , Models, Animal , Survival Analysis
6.
Dis Esophagus ; 24(3): 131-7, 2011 Apr.
Article in English | MEDLINE | ID: mdl-20946132

ABSTRACT

Foreign bodies should not be allowed to remain in the esophagus beyond 24 hours after presentation. However, some patients with esophageal foreign body ingestion do not come to the hospital immediately and may delay medical intervention from the time of ingestion. The aim of this study was to investigate the outcomes of adults with suspected esophageal foreign body ingestion according to the time of ingestion and types of foreign bodies. A total of 326 adult patients (151 men and 175 women) were analyzed, and divided into two groups according to the time period: within or beyond 24 hours from ingestion to endoscopic intervention. A total of 172 patients (52.7%) were found to have ingested foreign bodies; 73.5% were removed smoothly, 10.3% were treated by push technique and 16.0% with failed retrieval received alternative treatments. A higher proportion of patients in the beyond-24 hours group suffered from odynophagia (25.9 vs. 12.9%, P < 0.05). Negative identification of esophageal foreign bodies was more frequent in the beyond-24 hours group (67 vs. 40.2%, P < 0.05), but these patients showed higher proportions of esophageal ulcers (21.1 vs. 7.2%, P < 0.05). The beyond-24 hours group also showed a significantly higher rate of foreign bodies in the lower esophagus (40.0 vs. 15.3%, P < 0.05). Patients with esophageal food bolus impaction had significant delayed endoscopic intervention, longer therapeutic endoscopic time, higher proportions of esophageal cancer, stricture and fewer complications. Endoscopic intervention within 24 hours from the time of ingestion should be considered early in adults, because delaying intervention may produce more symptomatic esophageal ulcerations with odynophagia.


Subject(s)
Esophagus , Foreign Bodies/therapy , Adolescent , Adult , Aged , Aged, 80 and over , Esophagoscopy , Female , Food , Foreign Bodies/complications , Foreign Bodies/diagnosis , Humans , Male , Middle Aged , Time Factors , Treatment Outcome , Young Adult
7.
Dis Esophagus ; 23(2): 122-7, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19473206

ABSTRACT

Carcinosarcoma of the esophagus is a rare neoplasm with both carcinomatous and sarcomatous components. This study aimed to investigate its clinicopathologic features and endoscopic characteristics. The data of patients diagnosed to have esophageal carcinosarcoma pathologically in the past 30 years (January 1976-December 2007) were reviewed. Of 3318 cases of esophageal malignancy, 12 were diagnosed as esophageal carcinosarcoma, with an incidence of 0.36%. All of the cases were male with a mean age of 62.3 years. Of the 12 tumors, 8 were polypoid type, and 4 were ulcerative type. In the endoscopic ultrasonography examination, the tumors show heterogeneous hypoechoic lesions with irregular outer margins and internal multicystic components. Four patients (33.3%) had previous head and neck squamous cell carcinoma that occurred metachronously. This is the first report about the characteristics of esophageal carcinosarcoma under endoscopic ultrasonography examination. The relationship between esophageal carcinosarcomas and head and neck cancer needs further investigation.


Subject(s)
Carcinosarcoma/epidemiology , Esophageal Neoplasms/epidemiology , Age Factors , Aged , Alcohol Drinking/epidemiology , Areca , Carcinoma, Squamous Cell/epidemiology , Carcinosarcoma/secondary , Endoscopy, Digestive System , Endosonography , Follow-Up Studies , Head and Neck Neoplasms/epidemiology , Humans , Incidence , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Staging , Neoplasms, Second Primary/epidemiology , Polyps/epidemiology , Retrospective Studies , Risk Factors , Smoking/epidemiology , Survival Rate , Taiwan/epidemiology , Ulcer/epidemiology
8.
J Neural Transm (Vienna) ; 110(6): 641-9, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12768359

ABSTRACT

Recent studies indicate a possible link between serum cholesterol level, beta-amyloid (Abeta) peptide concentrations, and the incidence of Alzheimer's disease (AD). In the present report, the effects of dietary cholesterol on Abeta and apolipoprotein E (APOE) levels in several brain regions were examined using diet-induced hypercholesterolemic rabbits as the animal model. Increased dietary cholesterol levels increased Abeta concentrations in temporal cortex (p = 0.02). A similar trend was observed in the frontal cortex (p = 0.06), yet not in the cerebellum. Interestingly, the regional levels of Abeta in the hypercholesterolemic rabbit paralleled the amyloid pathology observed in AD brain. Elevated APOE levels were also noticed in temporal (p < 0.01) and frontal (p < 0.01) cortices, but not in cerebellum, in the rabbit fed with cholesterol-abundant diet. These results suggest that high serum cholesterol levels could induce the elevation of brain APOE, which may play a role in aggravating the Abeta accumulation.


Subject(s)
Alzheimer Disease/etiology , Amyloid beta-Peptides/metabolism , Apolipoproteins E/metabolism , Brain/metabolism , Hypercholesterolemia/complications , Up-Regulation/physiology , Alzheimer Disease/blood , Alzheimer Disease/physiopathology , Amyloid beta-Protein Precursor/metabolism , Animals , Brain/physiopathology , Cerebellum/metabolism , Cerebellum/physiopathology , Cerebral Cortex/metabolism , Cerebral Cortex/physiopathology , Food, Formulated , Hypercholesterolemia/blood , Hypercholesterolemia/physiopathology , Lipoproteins, HDL/blood , Lipoproteins, LDL/blood , Male , Rabbits
9.
J Opt Soc Am A Opt Image Sci Vis ; 18(10): 2491-501, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11583266

ABSTRACT

Diffractive optical element design is an important problem for many applications and is usually achieved by the Gerchberg-Saxton or the Yang-Gu algorithm. These algorithms are formulated on the basis of monochromatic wave propagation and the far-field assumption, because the Fourier transform is used to model the wave propagation. We propose an iterative algorithm (based on rigorous coupled-wave analysis) for the design of a diffractive optical element. Since rigorous coupled-wave analysis (instead of Fourier transformation) is used to calculate the light-field distribution behind the optical element, the diffractive optical element can thus be better designed. Simulation results are provided to verify the proposed algorithm for designing a converging lens. Compared with the well-known Gerchberg-Saxton and Yang-Gu algorithms, our method provides 7.8% and 10.8%, respectively, improvement in converging the light amplitude when a microlens is desired. In addition, the proposed algorithm provides a solution that is very close to the solution obtained by the simulated annealing method (within 1.89% error).

10.
Addiction ; 96(5): 729-36, 2001 May.
Article in English | MEDLINE | ID: mdl-11331031

ABSTRACT

AIMS: The causes of death among a series of patients with substance dependence were investigated. SETTING: A psychiatric teaching hospital in Taipei, Taiwan (Taipei City Psychiatric Center). PARTICIPANTS: A total of 1698 patients with various diagnostic categories of substance dependence, who had been admitted to TCPC for detoxification were followed-up from 1985 to 1996. DESIGN: A record-linkage study was performed using the patient's national identification number to link between TCPC chart records and the mortality file compiled by the National Department of Health. Risk factor analyses for mortality included socio-demographic data, clinical diagnosis and cause of death. FINDINGS: A total of 141 patients died during the study period. Among them, 83 had a diagnosis of alcohol dependence, 41 of heroin dependence and the remaining 17 cases of sedative, glue or hallucinogen dependence. The annual mortality rate of patients with heroin dependence was 1.94%. Accidental death is the leading cause of death among patients with heroin dependence. However, the patients with alcohol dependence had a higher mortality risk than those with heroin dependence (relative hazard = 1.91, p < 0.001) in this study. The proportion of non-violent death was significantly higher among the patients with alcohol dependence than those with heroin dependence (p < 0.005). CONCLUSION: The causes of death among patients with substance dependence found in this Taiwanese series were very similar to those reported in the western literature. However, differences included the absence of death among heroin addicts due to HIV-related disease and a markedly high percentage of alcoholic patients who died of liver diseases.


Subject(s)
Medical Record Linkage , Substance-Related Disorders/mortality , Accidents/statistics & numerical data , Adult , Aged , Alcohol-Related Disorders/mortality , Cause of Death , Demography , Female , Humans , Male , Middle Aged , Multivariate Analysis , Opioid-Related Disorders/mortality , Patient Admission , Proportional Hazards Models , Risk Factors , Statistics, Nonparametric , Taiwan/epidemiology , Violence/statistics & numerical data
11.
J Affect Disord ; 64(2-3): 185-93, 2001 May.
Article in English | MEDLINE | ID: mdl-11313085

ABSTRACT

BACKGROUND: Circulating soluble interleukin-2 receptors (sIL-2Rs) and soluble interleukin-6 receptors (sIL-6Rs) are stable immune measures. Elevated plasma sIL-2R levels are present in patients with schizophrenia, major depression, and bipolar mania, but not with minor psychiatric disorders. The increased plasma sIL-2R levels are state-dependent in bipolar mania. However, altered production of plasma sIL-6R and the effects of clinical characteristics on plasma sIL-6R and sIL-2R levels in bipolar disorder remains uncertain. METHODS: Plasma sIL-2R and sIL-6R levels were measured in 31 Taiwanese bipolar manic (DSM-IV) patients with Young Mania Rating Scale (YMRS) scores of > or =26 as well as during the subsequent remission (YMRS< or =12), and equal numbers of age- and gender-matched healthy controls. The relationships of clinical variables such as age, age of onset, smoking, medication status, coexisting psychotic features, number of prior episodes, duration of illness, presence of depression before or following the manic episode, and manic severity to plasma sIL-2R and sIL-6R levels in acute mania along with remission were examined. RESULTS: Plasma sIL-2R but not sIL-6R levels were significantly higher in acute mania than in subsequent remission (P<0.05) and controls (P<0.0005). In acute mania, the plasma sIL-2R levels were significantly correlated to YMRS scores (r=0.34, P<0.05). The remaining clinical variables had no effect on plasma sIL-2R and sIL-6R levels in acute mania or remission. There was a significantly positive relationship between the reduction of plasma sIL-2R levels from the acute to follow-up measurements (DeltasIL-2R) and symptomatic improvement of acute mania (DeltaYMRS) (r=0.61, P<0.001). LIMITATIONS: Our sample included medicated and unmedicated patients in acute mania. The psychotropic medication may have divergent effects on the plasma sIL-2R levels in acute mania and subsequent remission. CONCLUSIONS: Elevation of plasma sIL-2R but not sIL-6R levels in bipolar mania supports the idea that the immunomodulatory mechanism may vary in different psychotic disorders. In contrast to being a trait marker in schizophrenia and depressive disorder, plasma sIL-2R levels may be considered a biological indicator of manic severity in a group of bipolar affective patients.


Subject(s)
Bipolar Disorder/blood , Bipolar Disorder/diagnosis , Receptors, Interleukin-2/blood , Acute Disease , Adult , Biomarkers/blood , Circadian Rhythm/physiology , Female , Follow-Up Studies , Humans , Male , Psychiatric Status Rating Scales , Receptors, Interleukin-6/blood , Remission Induction , Severity of Illness Index , Solubility , Surveys and Questionnaires
12.
Proc Natl Sci Counc Repub China B ; 25(1): 17-25, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11254168

ABSTRACT

A selection procedure with three rules, high efficiency, low individual variability, and low redundancy, was developed to screen electroencephalogram (EEG) features for predicting behavioral alertness levels. A total of 24 EEG features were derived from temporal, frequency spectral, and statistical analyses. Behavioral alertness levels were quantified by correct rates of performance on an auditory and a visual vigilance task, separately. In the auditory task study, a subset of three EEG features, the relative spectral amplitudes in the alpha (alpha%, 8-13 Hz) and theta (theta%, 4-8 Hz) bands, and the mean frequency of the EEG spectrum (MF), was found to be the best combination for predicting the auditory alertness level. In the visual task study, the mean frequency of the beta band (Fbeta, 13-32 Hz) was the only EEG feature selected. The application of an averaging subwindow procedure within a moving time window to EEG analysis increased the predictive power of EEG features and decreased the disturbing effect of movement artifacts on the EEG data.


Subject(s)
Arousal/physiology , Auditory Perception/physiology , Electroencephalography , Visual Perception/physiology , Acoustic Stimulation , Adult , Artifacts , Electromyography , Female , Head Movements , Humans , Male , Neuropsychological Tests , Photic Stimulation
13.
Proc Natl Acad Sci U S A ; 98(8): 4605-10, 2001 Apr 10.
Article in English | MEDLINE | ID: mdl-11274374

ABSTRACT

Although the systemic administration of a number of different gene products has been shown to result in the inhibition of angiogenesis and tumor growth in different animal tumor models, the relative potency of those gene products has not been studied rigorously. To address this issue, recombinant adenoviruses encoding angiostatin, endostatin, and the ligand-binding ectodomains of the vascular endothelial growth factor receptors Flk1, Flt1, and neuropilin were generated and used to systemically deliver the different gene products in several different preexisting murine tumor models. Single i.v. injections of viruses encoding soluble forms of Flk1 or Flt1 resulted in approximately 80% inhibition of preexisting tumor growth in murine models involving both murine (Lewis lung carcinoma, T241 fibrosarcoma) and human (BxPC3 pancreatic carcinoma) tumors. In contrast, adenoviruses encoding angiostatin, endostatin, or neuropilin were significantly less effective. A strong correlation was observed between the effects of the different viruses on tumor growth and the activity of the viruses in the inhibition of corneal micropocket angiogenesis. These data underscore the need for comparative analyses of different therapeutic approaches that target tumor angiogenesis and provide a rationale for the selection of specific antiangiogenic gene products as lead candidates for use in gene therapy approaches aimed at the treatment of malignant and ocular disorders.


Subject(s)
Neovascularization, Pathologic , Proto-Oncogene Proteins/physiology , Receptor Protein-Tyrosine Kinases/physiology , Receptors, Growth Factor/physiology , Transfection , Adenoviridae/genetics , Amino Acid Sequence , Animals , Cell Division/genetics , Evaluation Studies as Topic , Humans , Mice , Molecular Sequence Data , Neoplasms/blood supply , Proto-Oncogene Proteins/genetics , Receptor Protein-Tyrosine Kinases/genetics , Receptors, Growth Factor/genetics , Receptors, Vascular Endothelial Growth Factor , Tumor Cells, Cultured , Vascular Endothelial Growth Factor Receptor-1
14.
J Cell Biol ; 152(6): 1219-32, 2001 Mar 19.
Article in English | MEDLINE | ID: mdl-11257122

ABSTRACT

Type XVIII collagen is a homotrimeric basement membrane molecule of unknown function, whose COOH-terminal NC1 domain contains endostatin (ES), a potent antiangiogenic agent. The Caenorhabditis elegans collagen XVIII homologue, cle-1, encodes three developmentally regulated protein isoforms expressed predominantly in neurons. The CLE-1 protein is found in low amounts in all basement membranes but accumulates at high levels in the nervous system. Deletion of the cle-1 NC1 domain results in viable fertile animals that display multiple cell migration and axon guidance defects. Particular defects can be rescued by ectopic expression of the NC1 domain, which is shown to be capable of forming trimers. In contrast, expression of monomeric ES does not rescue but dominantly causes cell and axon migration defects that phenocopy the NC1 deletion, suggesting that ES inhibits the promigratory activity of the NC1 domain. These results indicate that the cle-1 NC1/ES domain regulates cell and axon migrations in C. elegans.


Subject(s)
Axons/physiology , Caenorhabditis elegans/physiology , Cell Movement , Collagen/metabolism , Neurons/physiology , Peptide Fragments/metabolism , Protein Structure, Tertiary , Amino Acid Sequence , Angiogenesis Inhibitors/genetics , Angiogenesis Inhibitors/metabolism , Animals , Animals, Genetically Modified , Blotting, Western , Caenorhabditis elegans/cytology , Caenorhabditis elegans/genetics , Collagen/chemistry , Collagen/genetics , Collagen Type XVIII , Endostatins , Genes, Reporter/genetics , Male , Microscopy, Fluorescence , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/genetics , Protein Isoforms , RNA/antagonists & inhibitors , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Sequence Alignment
15.
J Cell Biol ; 152(6): 1233-46, 2001 Mar 19.
Article in English | MEDLINE | ID: mdl-11257123

ABSTRACT

Collagen XVIII (c18) is a triple helical endothelial/epithelial basement membrane protein whose noncollagenous (NC)1 region trimerizes a COOH-terminal endostatin (ES) domain conserved in vertebrates, Caenorhabditis elegans and Drosophila. Here, the c18 NC1 domain functioned as a motility-inducing factor regulating the extracellular matrix (ECM)-dependent morphogenesis of endothelial and other cell types. This motogenic activity required ES domain oligomerization, was dependent on rac, cdc42, and mitogen-activated protein kinase, and exhibited functional distinction from the archetypal motogenic scatter factors hepatocyte growth factor and macrophage stimulatory protein. The motility-inducing and mitogen-activated protein kinase-stimulating activities of c18 NC1 were blocked by its physiologic cleavage product ES monomer, consistent with a proteolysis-dependent negative feedback mechanism. These data indicate that the collagen XVIII NC1 region encodes a motogen strictly requiring ES domain oligomerization and suggest a previously unsuspected mechanism for ECM regulation of motility and morphogenesis.


Subject(s)
Bacterial Proteins , Cell Movement/physiology , Collagen/metabolism , Endothelium, Vascular/cytology , Extracellular Matrix/physiology , Peptide Fragments/metabolism , Protein Structure, Tertiary , Angiogenesis Inhibitors/genetics , Angiogenesis Inhibitors/metabolism , Animals , Bacterial Toxins/pharmacology , Blotting, Western , Cell Movement/drug effects , Cells, Cultured , Collagen/chemistry , Collagen/genetics , Collagen Type XVIII , Cytotoxins/pharmacology , Dimerization , Endostatins , Endothelium, Vascular/drug effects , Endothelium, Vascular/growth & development , Humans , Mice , Mitogen-Activated Protein Kinases/metabolism , Morphogenesis , Peptide Fragments/chemistry , Peptide Fragments/genetics , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , cdc42 GTP-Binding Protein/genetics , cdc42 GTP-Binding Protein/metabolism , rac GTP-Binding Proteins/genetics , rac GTP-Binding Proteins/metabolism , rho GTP-Binding Proteins/metabolism
16.
Appl Opt ; 40(32): 5894-7, 2001 Nov 10.
Article in English | MEDLINE | ID: mdl-18364882

ABSTRACT

In fabricating a diffractive optical element the ratio of the etching depth between the (n - 1)th and the nth mask is usually 1/2. We found that the diffraction efficiency of a diffractive optical element can be improved by as much as 7.8% if the above ratio (1/2) is not kept constant. For achieving this improvement the difference between the desired and the actual diffraction pattern is also used as an objective function for phase quantization.

17.
IEEE Trans Image Process ; 9(3): 329-39, 2000.
Article in English | MEDLINE | ID: mdl-18255406

ABSTRACT

The domain pool design is one of the dominant issues which affect the coding performance of fractal image compression. In this paper, we employ the LBG algorithm and propose a block averaging method to design the efficient domain pools based on a proposed iteration-free fractal image codec. The redundancies between the generated domain blocks are reduced by the proposed methods. Therefore, we can obtain the domain pools that are more efficient than those in the conventional fractal coding schemes and thus the coding performance is improved. On the other hand, the iteration process in the conventional fractal coding scheme not only requires a large size of memory and a high computation complexity but also prolongs the decoding process. The proposed iteration-free fractal codec can overcome the problems above. In computer simulation, both the LBG-based and block-averaging methods for the domain pool design in the proposed iteration free scheme achieve excellent performances. For example, based on the proposed block-averaging method, the decoded Lena image has at least a 0.5 dB higher PSNR (under the same bit rate) and an eight-time faster decoding speed than the conventional fractal coding schemes that require iterations.

18.
Oncogene ; 18(36): 5108-14, 1999 Sep 09.
Article in English | MEDLINE | ID: mdl-10490847

ABSTRACT

Rapamycin is an immunosuppressant which antagonizes cellular proliferation by inhibiting the function of mTOR. The mTOR:FKBP12: rapamycin complex blocks G1/S transition by inhibiting downstream targets essential for cell cycle progression. One such target is p70S6k1 (S6K1), a serine/threonine kinase which is inactivated by the mTOR : FKBP12 : rapamycin complex, and which has been linked to translational control by virtue of its ability to phosphorylate the ribosomal protein S6. In the current work, we describe cloning and characterization of a novel S6K1 homolog, p54 S6 kinase 2 (p54S6k2/S6K2). Similar to S6K1, S6K2 is activated by mitogens and by constitutively active PI3K, and is inhibited by rapamycin as well as wortmannin. Differences between activation of S6K1 and S6K2 by PDK1 were observed, suggesting potential differences in the regulation of these homologs. Strikingly, S6K2 activity and S6 phosphorylation were both intact in S6K1-/-ES cell, indicating a possible role for S6K2 in in vivo S6 phosphorylation. Interestingly, we found two isoforms of S6K2 which are localized to distinct cellular compartments; the smaller form resides in the detergent-soluble fraction, whereas the larger form is found in the particulate fraction. Our findings demonstrate the existence of a family of rapamycin-sensitive protein kinases potentially involved in S6 phosphorylation, translational control, and transduction of mTOR signals.


Subject(s)
Isoenzymes/genetics , Ribosomal Protein S6 Kinases/genetics , Sequence Homology, Nucleic Acid , Cell Line , Expressed Sequence Tags , Isoenzymes/metabolism , Molecular Sequence Data , Phosphorylation , Ribosomal Protein S6 Kinases/metabolism , Sirolimus/pharmacology
19.
Cell Growth Differ ; 10(12): 797-804, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10616904

ABSTRACT

To identify essential components of the Fas-induced apoptotic signaling pathway, Jurkat T lymphocytes were chemically mutagenized and selected for clones that were resistant to Fas-induced apoptosis. We obtained five cell lines that contain mutations in the adaptor FADD. All five cell lines did not express FADD by immunoblot analysis and were completely resistant to Fas-induced death. Complementation of the FADD mutant cell lines with wild-type FADD restored Fas-mediated apoptosis. Fas activation of caspase-2, caspase-3, caspase-7, and caspase-8 and the proteolytic cleavage of substrates such as BID, protein kinase Cdelta, and poly(ADP-ribose) polymerase were completely defective in the FADD mutant cell lines. In addition, Fas activation of the stress kinases p38 and c-Jun NH2 kinase and the generation of ceramide in response to Fas ligation were blocked in the FADD mutant cell lines. These data indicate that FADD is essential for multiple signaling events downstream of Fas.


Subject(s)
Adaptor Proteins, Signal Transducing , Carrier Proteins/metabolism , MAP Kinase Signaling System , fas Receptor/metabolism , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Carrier Proteins/genetics , Carrier Proteins/physiology , Caspase 8 , Caspase 9 , Caspases/metabolism , Ceramides/biosynthesis , Enzyme Activation , Fas-Associated Death Domain Protein , Genetic Complementation Test , Humans , JNK Mitogen-Activated Protein Kinases , Jurkat Cells , Mitogen-Activated Protein Kinases/metabolism , Mutagenesis , p38 Mitogen-Activated Protein Kinases
20.
IEEE Trans Image Process ; 8(1): 33-40, 1999.
Article in English | MEDLINE | ID: mdl-18262863

ABSTRACT

Noise reduction of VQ encoded images is achieved through the proposed anti-gray coding (AGC) and noise detection and correction scheme. In AGC, binary indices are assigned to the codevector in such a way that the 1-b neighbors of a code vector are as far apart as possible. To detect the channel errors, we first classify an image into uniform and edge regions. Then we propose a mask to detect the channel errors based on the image classification (uniform or edge region) and the characteristics of AGC. We also mathematically derive a criterion for error detection based on the image classification. Once error indices are detected, the recovered indices can be easily chosen from a "candidate set" by minimizing the gray-level transition across the block boundaries in a VQ encoded image. Simulation results show that the proposed technique provides detection results with smaller than 0.1% probability of error and more than 86.3% probability of detection at a random bit error rate of 0.1%, while the undetected errors are invisible. In addition, the proposed detection and correction techniques improve the image quality (compared with that encoded by AGC) by 3.9 dB.

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