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1.
Reprod Fertil Dev ; 31(6): 1078-1090, 2019 May.
Article in English | MEDLINE | ID: mdl-30922439

ABSTRACT

In mammals, tight regulation of maternal endometrial function is critical for pregnancy success. In bovine species, endometrial expression of members of the scavenger receptor class A (SR-A) has been listed in high-throughput analyses, but very little is known about the involvement of these immune factors during implantation in mammals. To provide first insights into the contribution of SR-A to endometrial physiology, we analysed the expression and regulation of all members of SR-A (SR-A1, SR-A3-SR-A6) during the oestrous cycle and early pregnancy in cattle. Levels of SR-A1 were increased on Day 20 of pregnancy, whereas SR-A3 levels were increased on Day 13 of the oestrous cycle and of the pregnancy. Although SR-A4 levels were reduced on Day 20 of the oestrous cycle, they remained high in pregnant animals. SR-A5 levels increased by Day 13 of the oestrous cycle and decreased on Day 20, but remained high in pregnant animals. Interferon-τ does not affect SR-A gene expression, whereas progesterone regulates the expression of the SR-A3 and SR-A5 transcripts. Endometrial SR-A3 appeared significantly higher in cows carrying invitro-produced embryos than in AI cows. Our data suggest that members of the SR-A family are involved in endometrial remodelling and regulation of endometrial gland physiology, both processes being critical for implantation in mammals.


Subject(s)
Endometrium/metabolism , Estrous Cycle/metabolism , Gene Expression Regulation/physiology , Pregnancy, Animal/metabolism , Scavenger Receptors, Class A/metabolism , Animals , Cattle , Embryo Implantation/physiology , Endometrium/drug effects , Female , Gene Expression Regulation/drug effects , Pregnancy , Pregnancy, Animal/genetics , Progesterone/pharmacology , Scavenger Receptors, Class A/genetics
2.
Reprod Fertil Dev ; 28(4): 459-74, 2016 Mar.
Article in English | MEDLINE | ID: mdl-25116692

ABSTRACT

Signal transducer and activator of transcription (STAT) proteins are critical for the regulation of numerous biological processes. In cattle, microarray analyses identified STAT1 as a differentially expressed gene in the endometrium during the peri-implantation period. To gain new insights about STAT1 during the oestrous cycle and early pregnancy, we investigated STAT1 transcript and protein expression, as well as its biological activity in bovine tissue and cells of endometrial origin. Pregnancy increased STAT1 expression on Day 16, and protein and phosphorylation levels on Day 20. In cyclic and pregnant females, STAT1 was located in endometrial cells but not in the luminal epithelium at Day 20 of pregnancy. The expression of STAT1 during the oestrous cycle was not affected by progesterone supplementation. In vivo and in vitro, interferon-tau (IFNT) stimulated STAT1 mRNA expression, protein tyrosine phosphorylation and nuclear translocation. Using chromatin immunoprecipitation in IFNT-stimulated endometrial cells, we demonstrated an increase of STAT1 binding on interferon regulatory factor 1 (IRF1), cytokine-inducible SH2-containing protein (CISH), suppressor of cytokine signaling 1 and 3 (SOCS1, SOCS3) gene promoters consistent with the induction of their transcripts. Our data provide novel molecular insights into the biological functions of STAT1 in the various cells composing the endometrium during maternal pregnancy recognition and implantation.


Subject(s)
Endometrium/metabolism , Interferon Type I/metabolism , Pregnancy Proteins/metabolism , STAT1 Transcription Factor/metabolism , Suppressor of Cytokine Signaling Proteins/metabolism , Active Transport, Cell Nucleus , Animals , Binding Sites , Cattle , Cells, Cultured , Embryo Implantation , Estrous Cycle/genetics , Estrous Cycle/metabolism , Female , Gene Expression Regulation , Gestational Age , Insemination, Artificial/veterinary , Phosphorylation , Pregnancy , Primary Cell Culture , Promoter Regions, Genetic , STAT1 Transcription Factor/genetics , Signal Transduction , Suppressor of Cytokine Signaling Proteins/genetics , Time Factors
3.
Reproduction ; 148(6): 545-57, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25187621

ABSTRACT

In mammals, suppressor of cytokine signalling (CISH, SOCS1 to SOCS7) factors control signalling pathways involved in the regulation of numerous physiological processes including pregnancy. In order to gain new insights into the biological functions of SOCS in the endometrium, a comprehensive analysis of SOCS gene expression was carried out in bovine caruncular (CAR) and intercaruncular (ICAR) tissues collected i) during the oestrous cycle, ii) at the time of maternal recognition of pregnancy and at implantation in inseminated females, iii) following uterine interferon-tau (IFNT) infusion at day 14 post-oestrus, iv) following a period of controlled intravaginal progesterone release and v) following transfer of embryos by somatic-cell nuclear transfer (SCNT). The regulatory effects of IFNT on in vitro cultured epithelial and stromal cells were also examined. Altogether, our data showed that CISH, SOCS4, SOCS5 and SOCS7 mRNA levels were poorly affected during luteolysis and pregnancy. In contrast, SOCS1, SOCS2, SOCS3 and SOCS6 mRNA levels were strongly up-regulated at implantation (day 20 of pregnancy). Experimental in vitro and in vivo models demonstrated that only CISH, SOCS1, SOCS2 and SOCS3 were IFNT-induced genes. Immunohistochemistry showed an intense SOCS3 and SOCS6 staining in the nucleus of luminal and glandular epithelium and of stromal cells of pregnant endometrium. Finally, SOCS3 expression was significantly increased in SCNT pregnancies in keeping with the altered immune function previously reported in this model of compromised implantation. Collectively, our data suggest that spatio-temporal changes in endometrial SOCS gene expression reflect the acquisition of receptivity, maternal recognition of pregnancy and implantation.


Subject(s)
Cattle/physiology , Embryo Implantation/physiology , Embryo, Mammalian/physiology , Endometrium/physiology , Gene Expression Regulation, Developmental/physiology , Suppressor of Cytokine Signaling Proteins/physiology , Animals , Cattle/genetics , Cells, Cultured , Embryo Implantation/genetics , Endometrium/cytology , Endometrium/drug effects , Estrous Cycle/physiology , Female , Gene Expression Regulation, Developmental/genetics , In Vitro Techniques , Interferon Type I/pharmacology , Interferon Type I/physiology , Pregnancy , Pregnancy Proteins/pharmacology , Pregnancy Proteins/physiology , Pregnancy, Animal/physiology , Progesterone/pharmacology , Progesterone/physiology , Signal Transduction/physiology , Suppressor of Cytokine Signaling Proteins/genetics
4.
Vox Sang ; 106(3): 219-26, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24117950

ABSTRACT

BACKGROUND AND OBJECTIVES: Refrigerated storage of red blood cells (RBCs) induces numerous changes that may target the cells for erythrophagocytosis following transfusion. The influence of storage upon the phagocytosis of unseparated and fractionated young and old stored RBCs was investigated using two in vitro quantitative phagocytosis assays. MATERIALS AND METHODS: Leucocyte-depleted RBC units were sampled at day 1 or 42 of storage. Young and old RBCs were fractionated at day 1 by density centrifugation and stored in paediatric packs for up to 42 days. RBCs were labelled with the fluorescent dye PKH26 and incubated with the human monocytic cell line THP-1. Erythrophagocytosis was quantified by flow cytometry and plate fluorometric assays. RESULTS: A higher proportion of THP-1 cells phagocytosed RBCs stored for 42 days compared with 1 day (41% and 24% respectively; P<0·0001). This was associated with an increased mean number of RBCs phagocytosed per THP-1 cell (5·2±0·6 and 3·3±0·2 respectively; P<0·002). Erythrophagocytosis of fractionated young and old RBCs increased with longer storage duration up to 28 days (P<0·05). However, no significant differences were observed between erythrophagocytosis of young and old RBCs. CONCLUSION: The susceptibility of stored RBCs to erythrophagocytosis significantly increased with longer storage time of the RBC units. Storage duration of RBCs had a greater influence on in vitro erythrophagocytosis than the chronological age of the RBCs at donation.


Subject(s)
Blood Preservation , Erythrocytes/immunology , Phagocytosis/immunology , Actins/antagonists & inhibitors , Blood Preservation/adverse effects , Cell Line, Tumor , Cellular Senescence/immunology , Cytochalasin D/chemistry , Erythrocytes/metabolism , Flow Cytometry , Fluorescent Dyes/chemistry , Fluorometry , Hemolysis/immunology , Humans , Organic Chemicals/chemistry , Polymerization/drug effects , Time Factors
5.
Reprod Domest Anim ; 47 Suppl 4: 402-9, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22827398

ABSTRACT

Microbes often infect the uterus and particularly the endometrium of animals. Infections are most commonly associated with natural service, pregnancy and the post-partum period, leading to inflammation with the elaboration of cytokines, chemokines and prostaglandins. Clinical diseases such as metritis, endometritis and abortion are important causes of infertility. The adaptive immune response to infection has been characterized previously, so the present review aims to highlight the emerging role for innate immunity in the endometrium. The detection of microbes and the innate immune response depends on the detection of pathogen-associated molecular patterns by pattern recognition receptors. The main families of pattern recognition receptors are Toll-like receptors (TLRs), nucleotide oligomerization domain-like receptors, retinoic acid-inducible gene I-like receptors and C-type lectin receptors. These receptors are most often expressed by hematopoietic cells, but the epithelial and stromal cells of the endometrium also possess functional receptors. For example, endometrial cells express TLR4 for recognition of the lipopolysaccharide endotoxin of Gram-negative bacteria, leading to secretion of IL-6, IL-8 and prostaglandin E(2) . It is likely that the epithelial and stromal cells provide a first line of defence in the endometrium to alert hematopoietic cells to the presence of microbes within the uterus.


Subject(s)
Inflammation/veterinary , Uterine Diseases/veterinary , Animals , Bacterial Infections/immunology , Bacterial Infections/pathology , Bacterial Infections/veterinary , Female , Humans , Immunity, Innate , Inflammation/immunology , Inflammation/pathology , Pregnancy , Uterine Diseases/immunology , Uterine Diseases/pathology , Uterus/immunology , Uterus/pathology
6.
Rural Remote Health ; 11(2): 1680, 2011.
Article in English | MEDLINE | ID: mdl-21702639

ABSTRACT

INTRODUCTION: Food insecurity is a chronic problem affecting Inuit communities. The most comprehensive assessment of Inuit food security to-date, the Inuit Health Survey, reported that 70% of Inuit pre-school children lived in 'food insecure' households. Food banks and soup kitchens are relatively new in the Arctic but the number of users is increasing. Little is known about the experience and determinants of food insecurity among food program users who are often among the most marginalized (socially and economically) in communities. The use of participatory research methods when working in the north of Canada can promote meaningful knowledge exchange with community members and this approach was used in the present 'Photovoice' research. Photovoice uses photography to develop a baseline understanding of an issue, in this case the experience and determinants of food insecurity among users of community food programs in Iqaluit, Nunavut. The target population includes those who face significant social and economic marginalization, an often neglected group in Arctic food systems research. METHODS: Eight regular users of food programs were recruited and engaged in a Photovoice research project to document factors determining their daily food consumption. The research method was introduced in workshops and discussion included the ethical concerns related to photography and how to take pictures. Participants were supplied with digital cameras, and asked to answer the following question using photography: 'What aspects of your everyday life affect what you eat and how much you have to eat?'. In the final workshop, photographs were discussed among the group and participants identified key themes in the photographs, offering an understanding of food insecurity from their perspectives. The group then discussed what should be done with the knowledge gained. RESULTS: Factors improving food security were the customary systems for sharing 'country food', and the presence of social support networks in the community, such as the Food Bank, the Soup Kitchen and the Tukisigiarvik Center. Factors identified as negatively affecting food security were the high cost of food in the Arctic, and substance abuse. The participants decided by consensus whether and how the knowledge from this project would be disseminated. They decided that a museum exhibit of the photographs in the summer of 2010 and promotion of the results among policy-makers in Nunavut were of high priority. CONCLUSION: The use of participatory research approaches such as Photovoice offers promise for exploring food security issues among similarly disadvantaged and vulnerable populations elsewhere in the Arctic. This approach was found to be a useful method for gathering and sharing research data because the data was generated and analysed by the participants. The clear and concise messages developed by the participants can be used to inform policy. This research method can assist in making a valuable contribution to health research, both in the Arctic and worldwide, because it promotes an understanding of the experiences of individuals from their own perspective.


Subject(s)
Diet , Food Supply , Inuit/psychology , Social Welfare/psychology , Community Participation , Diet/psychology , Female , Food Deprivation , Food Supply/economics , Humans , Male , Narration , Nunavut , Photography , Social Support
7.
Ann Oncol ; 22(2): 383-9, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20675559

ABSTRACT

BACKGROUND: Autoantibodies may be present in a variety of underlying cancers several years before tumours can be detected and testing for their presence may allow earlier diagnosis. We report the clinical validation of an autoantibody panel in newly diagnosed patients with lung cancer (LC). PATIENTS AND METHODS: Three cohorts of patients with newly diagnosed LC were identified: group 1 (n = 145), group 2 (n = 241) and group 3 (n = 269). Patients were individually matched by gender, age and smoking history to a control individual with no history of malignant disease. Serum samples were obtained after diagnosis but before any anticancer treatment. Autoantibody levels were measured against a panel of six tumour-related antigens (p53, NY-ESO-1, CAGE, GBU4-5, Annexin 1 and SOX2). Assay sensitivity was tested in relation to demographic variables and cancer type/stage. RESULTS: The autoantibody panel demonstrated a sensitivity/specificity of 36%/91%, 39%/89% and 37%/90% in groups 1, 2 and 3, respectively, with good reproducibility. There was no significant difference between different LC stages, indicating that the antigens included covered the different types of LC well. CONCLUSION: This assay confirms the value of an autoantibody panel as a diagnostic tool and offers a potential system for monitoring patients at high risk of LC.


Subject(s)
Autoantibodies/blood , Lung Neoplasms/diagnosis , Cohort Studies , Humans , Lung Neoplasms/immunology
8.
Ann Oncol ; 21(8): 1687-1693, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20124350

ABSTRACT

BACKGROUND: Publications on autoantibodies to tumour-associated antigens (TAAs) have failed to show either calibration or reproducibility data. The validation of a panel of six TAAs to which autoantibodies have been described is reported here. MATERIALS AND METHODS: Three separate groups of patients with newly diagnosed lung cancer were identified, along with control individuals, and their samples used to validate an enzyme-linked immunosorbant assay. Precision, linearity, assay reproducibility and antigen batch reproducibility were all assessed. RESULTS: For between-replicate error, samples with higher signals gave coefficients of variation (CVs) in the range 7%-15%. CVs for between-plate variation were only 1%-2% higher. For between-run error, CVs were in the range 15%-28%. In linearity studies, the slope was close to 1.0 and correlation coefficient values were generally >0.8. The sensitivity and specificity of individual batches of antigen varied slightly between groups of patients; however, the sensitivity and specificity of the panel of antigens as a whole remained constant. The validity of the calibration system was demonstrated. CONCLUSIONS: A calibrated six-panel assay of TAAs has been validated for identifying nearly 40% of primary lung cancers via a peripheral blood test. Levels of reproducibility, precision and linearity would be acceptable for an assay used in a regulated clinical setting.


Subject(s)
Autoantibodies/blood , Enzyme-Linked Immunosorbent Assay/methods , Lung Neoplasms/immunology , Adult , Aged , Aged, 80 and over , Case-Control Studies , Humans , Middle Aged , Quality Control , Reproducibility of Results
9.
Bone Marrow Transplant ; 33(4): 367-75, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14716351

ABSTRACT

SUMMARY: Graft-versus-host disease (GVHD) due to host-reactive antigenic differences between HLA-identical pairs remains an important cause of morbidity and mortality after allogeneic transplantation. The helper T-lymphocyte precursor (HTLp) assay, using peripheral blood mononuclear cells (PBMCs), has been variably shown to detect such host-reactive differences. We assessed whether using dendritic cells (DCs) as the stimulator cells would improve the ability of the HTLp assay to detect these differences. We used PBMCs (standard HTLp assay) or monocyte-derived DCs (DC-HTLp assay) as the stimulator cells for 12 HLA-identical sibling pairs undergoing allogeneic peripheral blood stem cell transplantation. HTLp frequencies were greater by the DC-HTLp assay (median 1:77 712 vs 1:727 514; P=0.008). The standard HTLp assay did not predict for acute GVHD (P=0.42), whereas a trend was noted for the DC-HTLp assay (P=0.095). Of note, of seven patients developing moderately severe to severe acute GVHD, four had a significantly greater DC-HTLp frequency compared to the standard HTLp frequency, whereas all four patients who developed no to moderate acute GVHD had similar HTLp frequencies whether PBMCs or DCs were used as the stimulator cells. Although the small number of donor/recipient pairs assessed limits the strength of any conclusions, our study suggests that the DC-HTLp assay is better able to detect clinically significant host-reactive antigenic differences between HLA-identical siblings.


Subject(s)
Graft vs Host Disease/immunology , Histocompatibility Testing/methods , Isoantigens/analysis , Lymphocyte Culture Test, Mixed/methods , Peripheral Blood Stem Cell Transplantation/methods , Adult , Animals , Cell Line , Cells, Cultured , Dendritic Cells/immunology , Female , Humans , Incidence , Lymphocyte Culture Test, Mixed/standards , Male , Mice , Middle Aged , Peripheral Blood Stem Cell Transplantation/standards , Predictive Value of Tests , Siblings , T-Lymphocytes, Helper-Inducer/immunology , Transplantation, Homologous , Transplantation, Isogeneic , Treatment Outcome
10.
Bone Marrow Transplant ; 30(6): 341-6, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12235517

ABSTRACT

Here, we report the first study assessing the helper T lymphocyte precursor (HTLp) frequency as a predictor of outcome in patients undergoing allogeneic PBSC transplantation. The HTLp assay uses limiting dilution analysis to measure the frequency, in PBMCs from the donor, of T lymphocytes capable of producing IL-2 in response to histocompatibility antigenic differences on PBMCs from the recipient. This assay has shown promise as a functional histocompatibility assessment used to predict the risk of recipients of HLA-matched donor bone marrow developing severe acute GVHD: the higher the HTLp frequency, the greater the significance of any histoincompatibility, and the greater the risk of severe acute GVHD. In the current report, the HTLp frequency was measured in 28 HLA-identical sibling pairs who subsequently underwent allogeneic PBSC transplantation for haematological malignancies. The HTLp frequency did not predict for acute GVHD (P = 0.38), chronic GVHD (P = 0.95), transplant-related mortality (P = 0.79), relapse (P = 0.39) or overall survival (P = 0.84). Converting the HTLp frequency to HTLp infused per kilogram of recipient body weight also did not predict for any of the outcome measures. We conclude that, although the HTLp assay may be useful for patients undergoing BMT, it does not predict for outcome after HLA-identical sibling donor G-CSF-mobilised PBSC transplantation.


Subject(s)
Granulocyte Colony-Stimulating Factor/administration & dosage , Peripheral Blood Stem Cell Transplantation/methods , T-Lymphocytes, Helper-Inducer/cytology , Adult , Female , Graft vs Host Disease , Granulocyte Colony-Stimulating Factor/pharmacology , Hematologic Neoplasms/complications , Hematologic Neoplasms/mortality , Hematologic Neoplasms/therapy , Hematopoietic Stem Cell Mobilization/methods , Humans , Lymphocyte Count , Male , Middle Aged , Peripheral Blood Stem Cell Transplantation/mortality , Prognosis , Prospective Studies , Recurrence , Siblings , Survival Rate , T-Lymphocytes, Helper-Inducer/immunology , Transplantation, Homologous , Transplantation, Isogeneic
11.
J Opt Soc Am A Opt Image Sci Vis ; 18(8): 1954-61, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11488499

ABSTRACT

We consider the problem of acquiring models for unknown materials in airborne 0.4-2.5 microm hyperspectral imagery and using these models to identify the unknown materials in image data obtained under significantly different conditions. The material models are generated with use of an airborne sensor spectrum measured under unknown conditions and a physical model for spectral variability. For computational efficiency, the material models are represented by using low-dimensional spectral subspaces. We demonstrate the effectiveness of the material models by using a set of material tracking experiments in HYDICE images acquired in forest and desert environments over widely varying conditions. We show that techniques based on the new representation significantly outperform methods based on direct spectral matching.

12.
J Endourol ; 14(4): 351-6, 2000 May.
Article in English | MEDLINE | ID: mdl-10910151

ABSTRACT

BACKGROUND AND PURPOSE: The best management of patients with low-stage, high-grade prostate cancer remains unclear. In an attempt to improve the outcomes of this high-risk group, we have offered those with Gleason > or =7 cancers removable-source high-dose-rate (HDR) brachytherapy in combination with external-beam radiation. PATIENTS AND METHODS: We reviewed the clinical histories of 61 consecutive patients with high-grade clinical stage T1-T2 lesions who received the combination radiation therapy between March 1997 and November 1998. The average Gleason score was 7.5. The HDR brachytherapy was given in three sessions with removable-source afterloaded (192)Ir to a minimum peripheral dose of 6 Gy. Conformal external-beam radiation in 25 fractions to a dose of 50 Gy was given beginning 1 week later. Patients with prostate volumes >40 cc received a luteinizing hormone-releasing hormone analog before brachytherapy. RESULTS: Among the 52 patients available for follow-up (average duration 11.8 months), there has been one death from prostate cancer. After treatment, only one patient had an initial rise in serum prostate specific antigen (PSA) concentration. In addition to the patient who died, there have been three confirmed treatment failures. Toxicity was mild, with only two patients having RTOG grade 3 or 4 effects. Neither of them required surgery. CONCLUSION: Although long-term results are not available, available data suggest that HDR brachytherapy plus external-beam radiation is at least as effective as any single therapy for high-risk, low-stage prostate cancer. The toxicity is acceptable.


Subject(s)
Brachytherapy , Prostatic Neoplasms/pathology , Prostatic Neoplasms/radiotherapy , Aged , Aged, 80 and over , Brachytherapy/adverse effects , Brachytherapy/instrumentation , Humans , Male , Middle Aged , Neoplasm Staging , Radiometry , Treatment Outcome
13.
Article in English | MEDLINE | ID: mdl-18252393

ABSTRACT

Color textures contain a large amount of spectral and spatial structure that can be exploited for recognition. Recent work has demonstrated that spatial filters offer a convenient means of extracting illumination-invariant spatial information from a color image. In this paper, we address the problem of deriving optimal filters for illumination-invariant color texture discrimination. Color textures are represented by a set of illumination-invariant features that characterize the color distribution of a filtered image region. Similar features have been used in previous studies. Given a pair of color textures, we derive a spatial filter that maximizes the distance between these textures in feature space. We provide a method for using the pairwise result to obtain a filter that maximizes discriminability among multiple classes. A set of experiments on a database of deterministic and random color textures obtained under different illumination conditions demonstrates the improved discriminatory power achieved by using an optimized filter.

14.
IEEE Trans Image Process ; 7(1): 124-8, 1998.
Article in English | MEDLINE | ID: mdl-18267387

ABSTRACT

We introduce a representation for color texture using unichrome and opponent features computed from Gabor filter outputs. The unichrome features are computed from the spectral bands independently while the opponent features combine information across different spectral bands at different scales. Opponent features are motivated by color opponent mechanisms in human vision. We present a method for efficiently implementing these filters, which is of particular interest for processing the additional information present in color images. Using a data base of 2560 image regions, we show that the multiscale approach using opponent features provides better recognition accuracy than other approaches.

15.
IEEE Trans Image Process ; 7(2): 196-203, 1998.
Article in English | MEDLINE | ID: mdl-18267393

ABSTRACT

We develop a method for recognizing color texture independent of rotation, scale, and illumination. Color texture is modeled using spatial correlation functions defined within and between sensor bands. Using a linear model for surface spectral reflectance with the same number of parameters as the number of sensor classes, we show that illumination and geometry changes in the scene correspond to a linear transformation of the correlation functions and a linear transformation of their coordinates. A several step algorithm that includes scale estimation and correlation moment computation is used to achieve the invariance. The key to the method is the new result that illumination, rotation, and scale changes in the scene correspond to a specific transformation of correlation function Zernike moment matrices. These matrices can be estimated from a color image. This relationship is used to derive an efficient algorithm for recognition. The algorithm is substantiated using classification results on over 200 images of color textures obtained under various illumination conditions and geometric configurations.

16.
IEEE Trans Image Process ; 6(7): 1002-13, 1997.
Article in English | MEDLINE | ID: mdl-18282990

ABSTRACT

Spatial filters provide a useful and efficient means of analyzing an input color image into components that capture different spatial properties. Representations based on spatial filtering have restricted usefulness for recognition, however, because the output of a spatial filter across an image depends on the scene illumination conditions. We use a physically accurate linear model for spectral reflectance to derive invariants of distributions in spatially filtered color images that do not depend on the scene illumination. These invariants can be used for the illumination-invariant recognition of regions following an arbitrary linear filtering operation. We describe a method for illumination correction based on color distributions and introduce an illumination change consistency constraint that is useful for verifying matches obtained using the invariants. We show, using a set of classification experiments, that the filtered distribution invariants can significantly improve the capability of a recognition system in environments where illumination cannot be controlled.

17.
Arzneimittelforschung ; 46(6): 560-6, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8767344

ABSTRACT

Oncogenicity studies of ramosetron ((R)-5-[(1-methyl-3-indolyl)carbonyl]-4,5,6,7-tetrahydro-1H-benzimidazol e hydrochloride, CAS 132907-72-3, YM060), a new compound having serotonin (5-HT)3 receptor antagonist activity, were carried out in male and female mice and rats. Six groups (two control and four treated) of B6C3F1 mice and F344 rats were given YM060, dissolved in distilled water, once daily by oral intubation at doses of 0, 1, 10, 30 and 100 mg/kg/d. Toxicokinetics indicated that sufficient exposure of the animals to the test material was achieved during the oncogenicity studies. Cmax and AUC of YM060 at 100 mg/kg/d were in the range of 3-5 micrograms/ml and 8 micrograms.h/ml in mice, 1-5 micrograms/ml and 7-16 micrograms.h/ml in rats, respectively. The administration of YM060 resulted in a slightly increased mortality rate among female rats treated with 30 or 100 mg/kg/d, particularly during the Weeks 38-87. Body weights of the high-dosed male and female rats during the Weeks 36 to 96 were significantly decreased when compared to controls. An approximately 30% suppression of body weight gain was recorded during Weeks 36-96 for both male and female rats, and 15% suppression of body weight gain was recorded during Weeks 0-104 for male mice. There was no evidence of a treatment-related effect on the incidence of any tumor or tumor type, and there were no non-neoplastic findings considered to be related to the administration of YM060. All microscopic changes seen in mice and rats were of the usual type commonly occurring in untreated aged B6C3F1 mice and F344 rats. In conclusion, there was no evidence of an oncogenic effect of YM060 in mice and rats.


Subject(s)
Benzimidazoles/toxicity , Carcinogens/toxicity , Serotonin Antagonists/toxicity , Animals , Benzimidazoles/pharmacokinetics , Eating/drug effects , Female , Male , Mice , Mice, Inbred Strains , Rats , Rats, Inbred F344 , Serotonin Antagonists/pharmacokinetics , Survival , Weight Gain/drug effects
18.
IEEE Trans Image Process ; 5(3): 447-58, 1996.
Article in English | MEDLINE | ID: mdl-18285130

ABSTRACT

We investigate to what extent textures can be distinguished using conditional Markov fields and small samples. We establish that the least square (LS) estimator is the only reasonable choice for this task, and we prove its asymptotic consistency and normality for a general class of random fields that includes Gaussian Markov fields as a special case. The performance of this estimator when applied to textured images of real surfaces is poor if small boxes are used (20x20 or less). We investigate the nature of this problem by comparing the behavior predicted by the rigorous theory to the one that has been experimentally observed. Our analysis reveals that 20x20 samples contain enough information to distinguish between the textures in our experiments and that the poor performance mentioned above should be attributed to the fact that conditional Markov fields do not provide accurate models for textured images of many real surfaces. A more general model that exploits more efficiently the information contained in small samples is also suggested.

19.
IEEE Trans Image Process ; 5(4): 635-45, 1996.
Article in English | MEDLINE | ID: mdl-18285151

ABSTRACT

In this paper, we attack the problem of distinguishing textured images of real surfaces using small samples. We first analyze experimental data that results from applying ordinary conditional Markov fields. In the face of the disappointing performance of these models, we introduce a random field with spatial interaction that is itself a random variable (usually referred to as a random field in a random environment). For this class of models, we establish the power spectrum and the autocorrelation function as well-defined quantities, and we devise a scheme for the estimation of related parameters. The new set of features that resulted from this approach was applied to real images. Accurate discrimination was observed even for boxes of size 10x16.

20.
Radiother Oncol ; 35(3): 193-7, 1995 Jun.
Article in English | MEDLINE | ID: mdl-7480821

ABSTRACT

Although the evolution from low dose rate to high dose rate brachytherapy for malignant endobronchial malignancies was primarily based on economy, patient convenience, and radiation protection, the difference in therapeutic index, if any, between these two modalities must be kept in mind. Our experience with both methods permits assessment of the feasibility of replacing low dose rate brachytherapy with high dose rate brachytherapy. Results with our first 110 patients (group 1) treated with low dose rate brachytherapy (133 procedures) were compared with results with our initial 59 consecutive patients (group 2) treated with high dose rate brachytherapy (161 procedures). In group 1, patients were treated with one or two sessions of 30-60 Gy each calculated at a 1 cm radius. In patients in group 2, we aimed at three weekly sessions of 7 Gy each calculated at a 1 cm radius. External beam irradiation therapy had previously been given to 88% of patients in group 1 and to 85% of patients in group 2. Laser bronchoscopy was performed in 36% of patients in group 1 and in 24% of patients in group 2 before brachytherapy. Clinical or bronchoscopic improvement was noted in 72% of patients in group 1 and in 85% of patients in group 2 (p > 0.05). Complication rates were low and comparable. Survival was similar in both groups (median < 6 months). Although both low dose rate and high dose rate brachytherapy appear equally effective in palliation for malignant endobronchial obstruction, we are now practicing the latter exclusively.


Subject(s)
Brachytherapy/methods , Iridium Radioisotopes/therapeutic use , Lung Neoplasms/radiotherapy , Aged , Case-Control Studies , Female , Humans , Lung Neoplasms/mortality , Male , Middle Aged , Radiotherapy Dosage , Radiotherapy, High-Energy , Survival Analysis
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