127 results on '"T C Pearson"'
Search Results
2. Rheology of Polycythemias T. C. Pearson
- Author
-
T. C. Pearson
- Subjects
Rheology ,Chemistry ,Thermodynamics ,Polycythemias - Published
- 2019
3. High-Speed Optical Sorting of Soft Wheat for Reduction of Deoxynivalenol
- Author
-
T. C. Pearson, Daniel L. Brabec, and Stephen R. Delwiche
- Subjects
Fusarium ,biology ,Optical sorting ,Sorting (sediment) ,food and beverages ,Plant Science ,biology.organism_classification ,chemistry.chemical_compound ,Fungal disease ,Animal science ,chemistry ,Vomitoxin ,Botany ,Poaceae ,Hordeum vulgare ,Mycotoxin ,Agronomy and Crop Science - Abstract
Fusarium head blight (FHB) is a fungal disease that affects small cereal grains, such as wheat and barley, and is becoming more prevalent throughout much of the world's temperate climates. The disease poses a health risk to humans and livestock because of the associated production of the mycotoxin deoxynivalenol (DON or vomitoxin) by the causal organism, Fusarium graminearum. A study was undertaken to examine the efficiency of high-speed, optical sorting of intact wheat (Triticum aestivum) kernels for reduction of DON concentration. Soft red winter (n = 32) and soft white (n = 3) wheat samples, known to have elevated levels of FHB, were obtained from commercial mills throughout the eastern United States. An additional seven samples of wheat from the discard piles of in-mill cleaners were also studied. Fusarium-damaged wheat, cleaned of nonkernels and foreign material ( ~4.5 kg/sample, DON range = 0.6 to 20 mg/kg), was fed into a commercial high-speed bichromatic sorter operating at a throughput of 0.33 kg/(channel-min) and a kernel rejection rate of 10%. A wavelength filter pair combination of 675 and 1,480 nm was selected for sorting, based on prior research. Visual measurements of the proportion of Fusarium-damaged kernels were collected on incoming and sorted seed (separate analyses of accepted and rejected portions), as were measurements of DON concentration. Results indicated that the fraction of DON contaminant level in the sorted wheat to that in the unsorted wheat ranged from 18 to 112%, with an average of 51%. Nine of the 35 regular samples and all seven of the discard pile samples underwent a second sort, with five from this second set undergoing a third sort. Multiple sorting was effective in producing wheat whose DON concentration was between 16 and 69% of its original, unsorted value.
- Published
- 2019
4. Impact of grain morphology and the genotype by environment interactions on test weight of spring and winter wheat (Triticum aestivum L.)
- Author
-
Jonathan Kleinjan, Dalitso N. Yabwalo, William A. Berzonsky, Karl D. Glover, Daniel L. Brabec, and T. C. Pearson
- Subjects
0106 biological sciences ,Mixed model ,Biplot ,04 agricultural and veterinary sciences ,Plant Science ,Horticulture ,Biology ,01 natural sciences ,Test weight ,Animal science ,Genetic gain ,Linear regression ,Genotype ,040103 agronomy & agriculture ,Genetics ,0401 agriculture, forestry, and fisheries ,Cultivar ,Gene–environment interaction ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
Wheat (Triticum aestivum L.) market grades and prices are determined in part by test weight (TW). Millers value high TW because it is typically associated with higher flour extraction rates and better end-use quality. Test weight is expected to be influenced by other directly quantifiable grain attributes such as grain length (GL), grain width (GW), shape, single-grain-density (SGD), thousand-grain-weight (TGW), and packing efficiency (PE). The objectives of this study were to: (1) determine the primary morphological grain attributes that comprise TW measurements for winter and spring wheat classes; and (2) determine TW stability and genotype and genotype × environment interactions (GEIs) of the attributes that comprise TW. A market class representative group of 32 hard spring and 24 hard winter wheat cultivars was grown at several locations in South Dakota in 2011 and 2012. A regularized multiple regression algorithm was used to develop a TW model and determine what grain attribute reliably predicts TW. A GGE biplot was used for stability and GEI analyses whereas a linear mixed model was used for variance analyses. Data were collected on eight grain traits: TW, SGD, TGW, protein concentration, GW, GL, shape, size, and PE. Observations showed that in both spring and winter wheat, SGD accounted for over 90% of the phenotypic variation of TW. Cultivars with stable and high TW were identified in both wheat classes. Apart from TW; significant (p
- Published
- 2018
5. Detection of Fragments from Internal Insects in Wheat Samples Using a Laboratory Entoleter
- Author
-
T. C. Pearson, Paul W. Flinn, Elizabeth B. Maghirang, and Daniel L. Brabec
- Subjects
Larva ,Agronomy ,Organic Chemistry ,Winter wheat ,Biology ,Water content ,Whole grains ,Food Science - Abstract
A simple, rapid method that uses a small mechanical rotary device (entoleter) was developed for estimating insect fragment counts in flour caused by hidden, internal-feeding insects in whole grains of hard red winter and soft red winter wheat. Known counts of preemergent adults, pupae, and larvae of lesser grain borers and rice weevils were blended with 500 g samples of uninfested wheat. The entoleter impeller speed was adjusted based on grain hardness and moisture content to obtain about ≈98% intact and ≈2–2.5% broken kernels in an uninfested sample. The entoleter flung the wheat kernels against a surrounding steel ring. Approximately 70–90% of the insect-infested kernels, being weaker, released internal insect pieces upon impact. The broken kernels were sieved with number 10 and number 20 sieves to obtain large-sieved and small-sieved fractions, respectively. Insect pieces in sieved fractions were counted. The insect piece counts were correlated with the estimated flour fragments (R2 = 0.94). T...
- Published
- 2015
6. The Management of Polycythaemia Vera
- Author
-
T. C. Pearson and T. Barbui
- Subjects
medicine.medical_specialty ,Pediatrics ,Polycythaemia ,Chlorambucil ,business.industry ,Pipobroman ,Hematology ,Anagrelide ,medicine.disease ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,Older patients ,030220 oncology & carcinogenesis ,Internal medicine ,Medicine ,Platelet ,business ,030215 immunology ,medicine.drug - Abstract
Thrombo-embolic complications are the commonest cause of morbidity and mortality in untreated PV. Control of the PCV (0.45) and platelet count (400 x 10(9)/I) minimizes the risk of these complications. In addition, suppression of megakaryocytic proliferation delays myelofibrotic transformation, which is probably the 'natural' long-term outcome of PV. A small percentage of patients transform to acute leukaemia, particularly after myelofibrotic transformation. Leukaemic transformation is enhanced with some forms of myelosuppression, notably high accumulated doses of chlorambucil and (32)P. Venesection should be used initially to reduce the PCV and subsequently as required. The choice of myelosuppressive agent depend on the patients age. Older patients can be managed with (32)P, low-dose busulphan or pipobroman. Hydroxyurea has a role in the management of patients at all ages, although it possibly enhances the leukaemogenic risk. Therefore, agents such as interferon-α or anagrelide should be considered in younger patients.
- Published
- 2016
7. Detection of Fungus-Infected Corn Kernels Using Near-Infrared Reflectance Spectroscopy and Color Imaging
- Author
-
Paul R. Armstrong, T. C. Pearson, D. T. Wicklow, and Jasper G. Tallada
- Subjects
genetic structures ,Color image ,business.industry ,Near-infrared spectroscopy ,technology, industry, and agriculture ,Biomedical Engineering ,Analytical chemistry ,food and beverages ,Soil Science ,Forestry ,Pattern recognition ,Linear discriminant analysis ,Perceptron ,Multilayer perceptron ,Principal component analysis ,Near infrared reflectance spectroscopy ,Color imaging ,Artificial intelligence ,business ,Agronomy and Crop Science ,Food Science ,Mathematics - Abstract
Contamination of grain products by fungus can lead to economic losses and is deleterious to human and livestock health. Detection and quantification of fungus-infected corn kernels would be advantageous for producers and breeders in evaluating quality and in selecting hybrids with resistance to infection. This study evaluated the performance of single-kernel near-infrared reflectance spectroscopy (NIRS) and color imaging to discriminate corn kernels infected by eight fungus species at different levels of infection. Discrimination was done according to the level of infection and the mold species. NIR spectra (904 to 1685 nm) and color images were used to develop linear and nonlinear prediction models using linear discriminant analysis (LDA) and multi-layer perceptron (MLP) neural networks. NIRS was able to accurately detect 98% of the uninfected control kernels, compared to about 89% for the color imaging. Results for detecting all levels of infection using NIR were 89% and 79% for the uninfected control and infected kernels, respectively; color imaging was able to discriminate 75% of both the control and infected kernels. In general, there was better discrimination for control kernels than for infected kernels, and certain mold species had better classification accuracy than others when using NIR. The vision system was not able to classify mold species well. The use of principal component analysis on image data did not improve the classification results, while LDA performed almost as well as MLP models. LDA and mean centering NIR spectra gave better classification models. Compared to the results of NIR spectrometry, the classification accuracy of the color imaging system was less attractive, although the instrument has a lower cost and a higher throughput.
- Published
- 2011
8. Detection of internal insects in wheat using a conductive roller mill and estimation of insect fragments in the resulting flour
- Author
-
Daniel L. Brabec, Paul W. Flinn, D. Katzke, and T. C. Pearson
- Subjects
biology ,media_common.quotation_subject ,fungi ,Winter wheat ,Wheat flour ,food and beverages ,Insect ,Horticulture ,biology.organism_classification ,Agronomy ,Insect Science ,Roller mill ,Bostrichidae ,Sample preparation ,Poaceae ,PEST analysis ,Agronomy and Crop Science ,Food Science ,media_common - Abstract
A laboratory roller mill that monitors the conductance of kernels that pass through it was tested for its ability to estimate the number of insect fragments in flour after milling. This system can test a kilogram of whole wheat in approximately 1 min and requires little sample preparation. Hard red winter wheat samples were infested with lesser grain borers and stored at 24 � C. Infestations ranged from 12 to over 2000 infested kernels per 1 kg or per 30,000 kernels. After crushing of samples in the conductance instrument, the samples were milled into flour and sub-samples were sent to two laboratories for insect fragment analysis. The insect fragments were proportional to the number of detection incidences obtained using the conductance instrument and X-ray images. Insect fragment counts per 50 g of flour ranged from 0 to over 5000. For insect fragment counts from 0 to 250, correlations between fragment counts and conductance mill detection were 0.75 and 0.80 from two separate cereal chemistry laboratories. Therefore, the conductance mill is potentially a good method for testing incoming grain for live internally infesting insects; it is able to test 1 kg of grain in about 1 min and can detect low levels (as low as three insects) of live internal infestations in a 1- or 2-kg sample. Published by Elsevier Ltd.
- Published
- 2010
9. Sorting of In-Shell Pistachio Nuts from Kernels Using Color Imaging
- Author
-
T. C. Pearson, Ronald P. Haff, and Natsuko Toyofuku
- Subjects
Pixel ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,General Engineering ,Sorting ,Pattern recognition ,Linear discriminant analysis ,k-nearest neighbors algorithm ,Histogram ,RGB color model ,Artificial intelligence ,Pistachio Nuts ,business ,Kernel (category theory) ,Mathematics - Abstract
Sorting pistachio kernels from in-shell nuts currently requires a combination of automated and manual sorting, an expensive and labor-intensive two-stage process. This research demonstrates the feasibility of using color imaging as a basis for distinguishing both regular and small in-shell pistachio nuts from kernels in the pistachio nut process stream. Two algorithms were developed to classify images of in-shell nuts, small in-shell nuts, and kernels. The first algorithm used a discriminant analysis (DA) routine to evaluate features extracted from the images based on histograms of red, green, and blue (RGB) pixel intensities, and resulted in a 99.9% overall accuracy for separating regular in-shell pistachio nuts from kernels. Small in-shell pistachio nuts were harder to discriminate from kernels, with an overall accuracy of 85%. The second algorithm used a k-nearest neighbors (knn) routine to evaluate features based on color histograms plus intensity slope information. The knn routine matched the accuracy of the DA algorithm for distinguishing regular in-shells from kernels with 99.9% correct. For the small in-shell case, however, the knn approach was superior with 96% accuracy. When used in a high-speed color imaging system, the algorithms would provide the means for economical high-speed sorting of in-shell pistachio nuts and kernels.
- Published
- 2010
10. Interpretation of Measured Red Cell Mass in the Diagnosis of Polycythaemia
- Author
-
U. H. Glass, T. C. Pearson, and G. Wetherley‐Mein
- Subjects
Male ,Polycythaemia ,Red Cell ,Body Surface Area ,Chemistry ,business.industry ,Body Weight ,Analytical chemistry ,Blood volume ,Polycythemia ,Hematology ,medicine.disease ,Body Height ,Confidence interval ,Sex Factors ,Body Water ,Reference Values ,Lean body mass ,medicine ,Humans ,Female ,Nuclear medicine ,business ,Erythrocyte Volume - Abstract
Expression of predicted and measured red cell mass (RCM) in terms of ml/kg body wt. lacks precision. The use of formulae for prediction of normal mean red cell mass derived from the blood volume prediction (BV) of Nadler et al (1962) has been examined. It is proposed that a more accurate determination of mean normal predicted red cell mass (MNRCM) is obtained by using: 0.47 times 0.91 × BV = MNRCM for males 0.43 times 0.91 × BV = MNRCM for females The MNRCMs given by these formulae agree with those given by predictions based on lean body mass and surface area. Examination of the ‘95 % confidence limits’ of the ‘Nadler’ prediction indicates that males with measured RCMs greater than 25 % and females with measured RCMs greater than 30 % above their MNRCM may be regarded as having polycythaemia.
- Published
- 2009
11. Technical Note: Characteristics and Sorting of White Food Corn Contaminated with Mycotoxins
- Author
-
D. T. Wicklow, Daniel L. Brabec, and T. C. Pearson
- Subjects
chemistry.chemical_compound ,Aflatoxin ,chemistry ,Botany ,Fumonisin ,General Engineering ,Dual wavelength ,Food science ,Contamination ,One pass ,Mycotoxin ,Food contaminant - Abstract
White corn grown in southern Texas was collected for characterization and evaluation of the feasibility of sorting kernels containing mycotoxins. Kernels were grouped into one of six symptom categories depending on the degree of visible discoloration and bright green-yellow fluorescence (BGYF) or bright orange fluorescence (BOF). Kernels visibly discolored (= 25% of their surface) and having BGYF contained over 57% of the aflatoxin. However, kernels approximately 50% discolored without BGYF contained over 35% of the aflatoxin. Over 33% of the fumonisin was found in kernels that were visibly discolored and had BOF. The remaining fumonisin was in asymptomatic kernels at low levels. Sorting tests for removing mycotoxin-contaminated kernels were performed using a dual wavelength high-speed commercial sorter. In one pass through the sorter, aflatoxin was reduced by an average of 46%, and fumonisin was reduced by 57% while removing 4% to 9% of the corn. Re-sorting accepted kernels a second time resulted in an 88% reduction in aflatoxin while removing approximately 13% of the corn. Approximately half of the aflatoxin missed by the optical sorter was found in larger kernels showing BGYF but no other symptoms, with the remaining aflatoxin in smaller kernels where the germ was damaged by insect feeding.
- Published
- 2009
12. Improved discrimination of soft and hard white wheat using SKCS and imaging parameters
- Author
-
T. C. Pearson, Hulya Dogan, and Daniel L. Brabec
- Subjects
Kernel (image processing) ,business.industry ,General Chemical Engineering ,Sample classification ,Real-time computing ,Pattern recognition ,Artificial intelligence ,Safety, Risk, Reliability and Quality ,Kernel size ,business ,Natural variation ,Industrial and Manufacturing Engineering ,Mathematics - Abstract
Natural variation of hardness of wheat kernels often results in overlapping hardness indices (HI) distributions between hard and soft classes as measured with the single kernel characterization system (SKCS). This is particularly true for the case of the hard white (HW) and soft white (SW) wheat classes. To address this problem, a color camera was incorporated into the SKCS system so that color and kernel size data could be combined with SKCS measurements for classification purposes. Samples of hard red (HR), soft red (SR), HW, and SW wheat were classified using the SKCS system with and without the camera and results compared. Using the camera system, errors for separating HW from SW classes were reduced to less than 5%, as compared to 17.1% using SKCS alone. Furthermore, improved data processing applied to the low-level data currently produced by the SKCS system led to greater than 50% reduction in classification errors between SW and HR as compared to using HI data alone. Similar improvements in classification accuracies for 300-kernel sample containing mixtures of SW and HW were also achieved. The 300 kernel sample classification is usually what inspectors and grain traders use to determine sample purity rather than individual kernel results. The techniques developed should aid grain inspectors in properly identifying mixtures of these two classes. Unfortunately, for the SR and HR classes, incorporating the camera data decreased classification accuracy while increasing the complexity of the system. However, SR and HR classes can be adequately distinguished with the SKCS in its current form.
- Published
- 2008
13. The course and complications of idiopathic erythrocytosis
- Author
-
T. C. Pearson and G. Wetherley-Mein
- Subjects
Adult ,Male ,medicine.medical_specialty ,Pediatrics ,Polycythaemia ,Erythrocytes ,business.industry ,Clinical course ,Polycythemia ,Hematology ,Middle Aged ,medicine.disease ,Surgery ,Primary proliferative polycythaemia ,medicine ,Humans ,Female ,Idiopathic erythrocytosis ,Vascular Diseases ,High incidence ,Presentation (obstetrics) ,business ,Cell Division ,Aged ,Erythrocyte Volume - Abstract
Summary The presenting features, haematological and clinical course of 30 patients with unexplained high venous haematocrit have been analysed. At presentation these patients had definite polycythaemia, but lacked other features which would permit their classification as primary proliferative polycythaemia (PPP). In the follow-up period, twelve patients (40%) developed features within 6 years of diagnosis which allowed them to be reclassified as PPP. It is suggested that, because of this transition, the term idiopathic erythrocytosis is a more suitable initial description of this group than, for example, benign erythrocytosis. The high incidence of vascular complications at presentation, and the fact that a cerebrovascular accident was responsible for the death of five out of the seven patients who have so far died, is discussed and compared with similar events in PPP. The existence of a pure line red cell proliferation cannot be confirmed or excluded by the observations in the present group of patients. The findings do indicate that follow-up and observation of such patients may establish causes for polycythaemia not in evidence or considered at presentation.
- Published
- 2008
14. Blood transfusion in pregnancies complicated by maternal sickle cell disease. Effects on blood rheology and uteroplacental Doppler velocimetry
- Author
-
Susan M. Tuck, T. C. Pearson, and Richard J. Howard
- Subjects
medicine.medical_specialty ,Blood transfusion ,Placenta ,medicine.medical_treatment ,Hemoglobin, Sickle ,Blood viscosity ,Exchange Transfusion, Whole Blood ,Anemia, Sickle Cell ,Hematocrit ,Pregnancy ,Internal medicine ,Laser-Doppler Flowmetry ,medicine ,Humans ,Blood Transfusion ,Prospective Studies ,skin and connective tissue diseases ,Maternal-Fetal Exchange ,Ultrasonography ,medicine.diagnostic_test ,business.industry ,Pregnancy Complications, Hematologic ,Uterus ,Hematology ,Blood flow ,Laser Doppler velocimetry ,Blood Viscosity ,medicine.disease ,Sickle cell anemia ,Surgery ,medicine.anatomical_structure ,Regional Blood Flow ,Uteroplacental Circulation ,Vascular resistance ,Cardiology ,Female ,Vascular Resistance ,sense organs ,business - Abstract
Doppler ultrasound gives a measure of downstream resistance to blood flow. In this study it has been used to assess the change in placental vascular resistance following blood transfusion in pregnancies complicated by sickle cell disease. Eight women with homozygous sickle cell disease were followed prospectively to assess the effect of transfusion on haemoglobin S percentage, blood and plasma viscosity and uteroplacental Doppler velocimetry. Measurements were made immediately pre and post-transfusion and after several weeks when the desired improvement in haemoglobin S had been achieved. Despite significant changes in haemoglobin S levels and consequent rheological change there was found to be no change in measurements of resistance in the uteroplacental circulation as assessed by Doppler ultrasound.
- Published
- 2008
15. The interpretation of measured red cell mass and plasma volume in patients with elevated PCV values
- Author
-
T. C. Pearson and D. L. Guthrie
- Subjects
Adult ,Erythrocyte Indices ,Male ,Polycythaemia ,Red Cell ,Incidence (epidemiology) ,Polycythemia ,Hematology ,Normal values ,Middle Aged ,medicine.disease ,Plasma volume ,Interpretation (model theory) ,Sex Factors ,Hematocrit ,Statistics ,medicine ,Humans ,Female ,In patient ,Plasma Volume ,Mathematics ,Normal range ,Aged - Abstract
Summary. Various formulae using both height and weight have been proposed to interpret measured red cell mass (RCM) and plasma volume (PV). This paper compares four different methods for evaluating these measurements in 50 males with PCV values above 0.51 and three different methods for evaluating results in 50 females with PCV values above 0.49. Overall there was close agreement in the RCM result expressions by all methods for both males and females except at extremes of height and/or weight. The incidence of absolute polycythaemia in both sexes was influenced by the width of the normal range. When this was taken into account overall the incidence of polycythaemia was similar, but in a small number of individuals there were discrepancies of interpretation. These individual patient differences establish that decisions regarding further investigations of a patient must not rest on a strict interpretation of a measured RCM. The various methods of measured PV interpretation gave dissimilar results-in particular by one of the male PV interpretation methods. The differences in the methods almost certainly reflect methodological discrepances in the original techniques used to establish the normal values. The differences in result expression for PV would however lead to a different incidence of relative, low plasma volume, polycythaemia by the various techniques.
- Published
- 2008
16. Separating in-shell pistachio nuts from kernels using impact vibration analysis
- Author
-
Ron P. Haff and T. C. Pearson
- Subjects
Vibration ,General Chemical Engineering ,Acoustics ,Speech recognition ,Nozzle ,Shell (structure) ,Sorting ,Safety, Risk, Reliability and Quality ,Pistachio Nuts ,Throughput (business) ,Industrial and Manufacturing Engineering ,Kernel (category theory) ,Mathematics - Abstract
A sorting system has been developed for the separation of small in-shell pistachio nuts from kernels without shells on the basis of vibrations generated when moving samples strike a steel plate. Impacts between the steel plate and the hard shells, as measured using an accelerometer attached to the bottom of the plate, produce higher frequency signals than impacts between the plate and the kernels. Signal amplitudes, on the other hand, were highly variable and by themselves were not useful for the separation of samples. An algorithm was developed using both amplitude and frequency information to classify the signals. The algorithm activated an air nozzle to divert in-shell nuts away from the kernel stream. A prototype sorter was tested at throughput rates of 0.33, 10, 20, and 40 nuts per second using a mix of 10% in-shell and 90% kernels. At the lowest throughput rate, classification accuracies were 96% for in-shell nuts and 99% for kernels. For throughput rates between 10 and 40 nuts/s, correct classification ranged from 84 to 90% for in-shell nuts. For kernels, accuracy was 95% at 10 and 20 nuts/s and 89% at 40 nuts/s.
- Published
- 2007
17. An automatic algorithm for detection of infestations in X-ray images of agricultural products
- Author
-
Ronald P. Haff and T. C. Pearson
- Subjects
Agricultural commodity ,biology ,General Chemical Engineering ,Sitophilus ,biology.organism_classification ,Linear discriminant analysis ,Industrial and Manufacturing Engineering ,Total error ,X ray image ,Decision boundary ,Decision function ,Bactrocera ,Safety, Risk, Reliability and Quality ,Algorithm ,Mathematics - Abstract
An automatic recognition algorithm was developed and tested for detection of certain defects or contaminants in X-ray images of agricultural commodities. Testing of the algorithm on wheat kernels infested with larvae of the granary weevil, Sitophilus granarius (L.) yielded comparable results to those obtained by human subjects evaluating digitized X-ray film images (14.4% overall error vs. 15.6% for human subjects). Further tests on X-ray images of olives infested with the Olive Fly, Bactrocera oleae (L.), yielded a total error of 12% for large infestations and over 50% for the smallest infestations with false positive results below 10%. Testing of alternate training strategies showed that for this type of algorithm, which uses a form of discriminant analysis with a generally “fuzzy” decision boundary, best results are obtained when training with samples that map far away from the boundary, then applying the derived decision function to all samples to be classified.
- Published
- 2007
18. DETECTION OF CORN KERNELS INFECTED BY FUNGI
- Author
-
D. T. Wicklow and T. C. Pearson
- Subjects
Fusarium ,biology ,Color image ,Near-infrared spectroscopy ,Biomedical Engineering ,Diplodia maydis ,Soil Science ,Forestry ,Aspergillus flavus ,Spectral bands ,biology.organism_classification ,Reflectivity ,Horticulture ,Botany ,Agronomy and Crop Science ,Kernel (category theory) ,Food Science ,Mathematics - Abstract
Single-kernel reflectance spectra (550 to 1700 nm), visible color reflectance images, x-ray images, multi-spectral transmittance images (visible and NIR), and physical properties (mass, length, width, thickness, and cross-sectional area) were analyzed to determine if they could be used to detect fungal-infected corn kernels. Kernels were collected from corn ears inoculated with one of several different common fungi several weeks before harvest, and then collected at harvest time. It was found that two NIR reflectance spectral bands centered at 715 nm and 965 nm could correctly identify 98.1% of asymptomatic kernels and 96.6% of kernels showing extensive discoloration and infected with Aspergillus flavus, Aspergillus niger, Diplodia maydis, Fusarium graminearum, Fusarium verticillioides, or Trichoderma viride. These two spectral bands can easily be implemented on high-speed sorting machines for removal of fungal-damaged grain. Histogram features from three transmittance images (blue and red components of color images and another at 960 nm) can distinguish 91.9% of infected kernels with extensive discoloration from 96.2% of asymptomatic kernels. Similar classification accuracies were achieved using x-ray images and physical properties (kernel thickness, weight, length). A neural network was trained to identify infecting fungal species on single kernels using principle components of the reflectance spectra as input features.
- Published
- 2006
19. Camera Attachment for Automatic Measurement of Single-Wheat Kernel Size on a Perten SKCS 4100
- Author
-
T. C. Pearson and Daniel L. Brabec
- Subjects
Kernel (image processing) ,business.industry ,General Engineering ,Computer vision ,Artificial intelligence ,Kernel size ,business ,Mathematics - Abstract
A simple camera was attached to a Perten Single-Kernel Characterization System (SKCS) 4100 to measure single kernel morphology as they are fed through the SKCS. The camera and lighting were positioned above the SKCS weigher bucket. Each image of a wheat kernel was captured and processed in 15 to 60 ms. Image measurements included kernel area, length, and width.
- Published
- 2006
20. NON-DESTRUCTIVE DETECTION OF PITS IN DRIED PLUMS
- Author
-
T. C. Pearson, E. S. Jackson, and Ronald P. Haff
- Subjects
Compressive strength ,Force transducer ,Materials science ,Acoustics ,Non destructive ,General Engineering ,Forensic engineering ,Classification methods ,Compression (physics) ,Signal - Abstract
An economical, non-destructive device was constructed to detect pits in dried plums (prunes). The device compresses the product between a roller and a force transducer, which detects the higher force generated when a pit is present. Two methods of classifying fruit were developed, one based on the maximum magnitude of the compression force and the other on analysis of the frequency spectra of the force transducer signal during compression. The accuracy of the former was 98.6% for pitted fruit and 69.4% for fruit with pits, versus 99.1% and 75.3% for the latter. The frequency spectra classification method was more accurate, but more complex and costly to implement. The requirement to restrict the compression of the fruit to be non-destructive precludes the possibility to detect small pit fragments using this method. However, the low cost of materials for the device make it a potential method to supplement other technology currently in use to reduce the pit count in the final product.
- Published
- 2005
21. Reduction of Aflatoxin and Fumonisin Contamination in Yellow Corn by High-Speed Dual-Wavelength Sorting
- Author
-
T. C. Pearson, Donald T. Wicklow, and M. C. Pasikatan
- Subjects
Aflatoxin ,biology ,Organic Chemistry ,Sorting ,Aspergillus flavus ,Contamination ,biology.organism_classification ,Reflectivity ,Absorbance ,chemistry.chemical_compound ,Horticulture ,chemistry ,Fumonisin ,Botany ,Dual wavelength ,Food Science - Abstract
A high-speed dual-wavelength sorter was tested for removing corn contaminated in the field with aflatoxin and fumonisin. To achieve accurate sorting, single kernel reflectance spectra (500–1,700 nm) were analyzed to select the optimal pair of optical filters to detect mycotoxin-contaminated corn during high-speed sorting. A routine, based on discriminant analysis, was developed to select the two absorbance bands in the spectra that would give the greatest classification accuracy. In a laboratory setting, and with the kernels stationary, absorbances at 750 and 1,200 nm could correctly identify >99% of the kernels as aflatoxin-contaminated (>100 ppb) or uncontaminated. A high-speed sorter was tested using the selected filter pair for corn samples inoculated with Aspergillus flavus; naturally infested corn grown in central Illinois; and naturally infested, commercially grown and harvested corn from eastern Kansas (2002 harvest). For the Kansas corn, the sorter was able to reduce aflatoxin levels by ...
- Published
- 2004
22. The incidences of trisomy 8, trisomy 9 and D20S108 deletion in polycythaemia vera: an analysis of blood granulocytes using interphase fluorescence in situ hybridization
- Author
-
Mary Frances McMullin, C. E. Pearson, T. C. Pearson, Brian J. P. Huntly, Nigel Westwood, Anthony R. Green, Alicja M. Gruszka-Westwood, A. Lakhani, and C. F. M. DeLord
- Subjects
Polycythaemia ,medicine.medical_specialty ,medicine.diagnostic_test ,Cytogenetics ,Aneuploidy ,Hematology ,Biology ,medicine.disease ,Trisomy 8 ,Trisomy 9 ,Molecular biology ,Polycythemia vera ,medicine ,Trisomy ,Fluorescence in situ hybridization - Abstract
We have used interphase fluorescence in situ hybridization (IFISH) to detect trisomy 8, trisomy 9 and 20q deletion in circulating granulocytes from patients with polycythaemia vera (PV). Out of 64 PV patients, 15 (23%) exhibited an abnormality. Two patients had trisomy 9, three had trisomy 8 and 10 patients had hemizygous deletion of D20S108 (a locus in the 20q common deleted region). Aberrant nuclei ranged from 10% to 80% in these 15 cases. There was no correlation between the presence of a marker and sex, age, interval between presentation and IFISH analysis, neutrophil or platelet count or therapy. Conventional marrow cytogenetic karyotype results were available in 23 cases and there was concurrence between these and blood IFISH in 16 cases (13 normal and three with 20q/D20S108 deletion by both methods). Three patients with D20S108 deletion by IFISH were normal by previous marrow cytogenetic testing and four cases with 20q deletion by previous marrow cytogenetics had normal blood granulocytes according to IFISH. Thus, we confirm that trisomies 8 and 9 and deletion of 20q are diagnostically useful markers of PV. IFISH analysis of blood granulocytes is a practical method for detecting these markers, but as an adjunct to, not as a substitute for, conventional marrow cytogenetics.
- Published
- 2000
23. AUTOMATED SORTING OF PISTACHIO NUTS WITH CLOSED SHELLS
- Author
-
N. Toyofuku and T. C. Pearson
- Subjects
Engineering ,Channel (digital image) ,business.industry ,Machine vision ,General Engineering ,Sorting ,business ,Pistachio Nuts ,Material handling ,Throughput (business) ,Computer hardware ,Digital signal processing ,Machine vision system - Abstract
An automated machine vision system was developed to identify and remove pistachio nuts with closed shells from processing streams. The system includes a novel material handling system to feed nuts to linescan cameras without tumbling. The camera output signals are input to digital signal processing boards which extract image features characteristic of closed and open shell pistachios. The classification accuracy of this machine vision system for separating open shell from closed shell nuts is approximately 95%. The system has a throughput rate of approximately 40 nuts per second and cost of about $15,000 per channel. This throughput and cost is comparable to color sorters used to remove other pistachio defects. Currently, closed shell pistachio nuts are removed by mechanical devices. These devices also have a classification accuracy of about 95% but damage kernels in open shell pistachios by “pricking” them with a needle. The needle hole can give the appearance of an insect tunnel and cause rejection by the consumer. The newly developed machine vision system is a non-invasive inspection method.
- Published
- 2000
24. Postpartum thrombosis in primary thrombocythaemia
- Author
-
B. E. Woodcock, S. Fairhead, S. J. B. Willoughby, and T. C. Pearson
- Subjects
Pediatrics ,medicine.medical_specialty ,business.industry ,Medicine ,Hematology ,General Medicine ,business ,medicine.disease ,Thrombosis ,Primary thrombocythaemia - Published
- 2009
25. Sickle cell disease and nitrous oxide-induced neuropathy
- Author
-
O. Ogundipe, Matthew C. Walker, T. Adepegba, N. G. P. Slater, T. C. Pearson, and N. Westerdale
- Subjects
medicine.diagnostic_test ,Anemia ,business.industry ,Neurological examination ,Hematology ,Macrocytosis ,medicine.disease ,Sickle cell anemia ,Pernicious anaemia ,Peripheral neuropathy ,Anesthesia ,medicine ,Vitamin B12 ,Complication ,business - Abstract
We report three cases of peripheral neuropathy in patients with sickle cell disease. All had a history of frequent painful crises and regular attendance at our Accident and Emergency department where nitrous oxide analgesia was administered for prolonged periods. All three patients (one male and two females) presented with difficulty in walking associated with paraesthesiae, and neurological examination revealed signs compatible with a peripheral sensorimotor neuropathy, later confirmed by nerve conduction studies. Serum vitamin B12 levels were mildly reduced in two patients and very low in one patient (< 10 ng/l). Haemoglobin levels in all the patients were unchanged compared with their steady-state levels but one had developed a macrocytosis (103 fl). Schilling tests were normal in two patients, and two patients had negative gastric parietal antibodies. All three patients were given intramuscular vitamin B12 in addition to avoiding further exposure to nitrous oxide, and their neurological symptoms improved completely. As nitrous oxide is known to cause a neuropathy similar to that seen in pernicious anaemia, we postulate that nitrous oxide analgesia combined with low B12 levels was the cause of the marked neuropathy in these patients. As a result of our observations and the probable association, we now do not use nitrous oxide analgesia in the management of patients with sickle cell disease.
- Published
- 1999
26. Machine Vision System for Automated Detection of Aflatoxin-Contaminated Pistachios
- Author
-
Thomas F. Schatzki and T. C. Pearson
- Subjects
Aflatoxin ,Product recovery ,Sorting ,sort ,Gross defects ,General Chemistry ,Contamination ,General Agricultural and Biological Sciences ,Pulp and paper industry ,Mathematics ,Machine vision system - Abstract
The previously reported [Pearson, T. Lebensm. Wiss. -Technol. 1996, 28 (6), 203−209] channel image sorter has been used to re-sort color-sort and hand-sort rejects and to sort mainstream (pre-hand-sort) U.S. pistachios. Sorting was carried out at commercial speeds of up to 163 kg/channel/h. Recoveries of good nuts of 39−67% on re-sorted product and 97.8% on mainstream nuts were achieved. Aflatoxin levels were reduced from 8.6−4.8 to 0.04−2.5 ng/g on color-sort rejects and to 15 from 22 ng/g on hand-sort rejects. For mainstream product, aflatoxin levels were reduced from 0.12 to 0 ng/g by image sorting, compared to reduction to 0.04 ng/g by hand sorting. Quality for mainstream sorting improved significantly, particularly for other damage, serious insect damage, gross defects, and loose kernels. Re-sort quality improved as well, but recovered product will still require dyeing. The sorter should find application in product recovery, in preparation of product for very stringent markets [Schatzki, T. F. J. Agr...
- Published
- 1998
27. Blocking the CD28-B7 T cell costimulation pathway induces long term cardiac allograft acceptance in the absence of IL-4
- Author
-
F G Lakkis, B T Konieczny, S Saleem, F K Baddoura, P S Linsley, D Z Alexander, R P Lowry, T C Pearson, and C P Larsen
- Subjects
Immunology ,Immunology and Allergy - Abstract
Blocking the CD28-B7 T lymphocyte costimulatory pathway with the recombinant protein CTLA4Ig induces long term allograft survival in rodents. It has been suggested that this results from selective activation of the Th2 immune pathway. To test this hypothesis, we compared vascularized cardiac allograft survival in wild-type (IL-4 +/+) and homozygous IL-4 gene-knockout (IL-4 -/-) mice. We report in this study that long term survival (>100 days) of fully allogeneic grafts can be induced readily in IL-4 -/- recipients treated with a short course of CTLA4Ig. We also demonstrate that IL-4 -/- mice are deficient in Th2-type cytokine expression following in vitro or in vivo allostimulation. These results suggest that IL-4 production and subsequent generation of a Th2-type immune response are not obligatory for CTLA4Ig-induced long term acceptance of vascularized allografts.
- Published
- 1997
28. One Dimensional Linescan x-ray Detection of Pits in Fresh Cherries
- Author
-
T. C. Pearson, R. P. Haff, and E. S. Jackson
- Subjects
Orientation (computer vision) ,Computer science ,business.industry ,Detector ,Total error rate ,Signal ,Total error ,Photodiode ,law.invention ,law ,General Earth and Planetary Sciences ,Computer vision ,Artificial intelligence ,business ,General Environmental Science - Abstract
The presence of pits in processed cherries is a concern for both processors and consumers, in many cases causing injury and potential lawsuits. While machines used for pitting cherries are extremely efficient, if one or more plungers in a pitting head become misaligned, a large number of pits may pass before corrective action is taken. While x-ray imaging has the potential to detect pits, traditional commercially available equipment is expensive and bulky, and implementation on the processing line is cumbersome. An x-ray inspection system using an array of photodiode based x-ray detectors in a linescan configuration whose outputs are combined to produce a one dimensional signal would be simpler, faster, and more economical. The data collection process is then reduced from a two dimensional image to a much simpler one dimensional signal, resulting in faster and simpler processing and classification. An algorithm designed to differentiate unpitted from pitted cherries for such a system yielded recognitiothe unpitted cherries, with a total error rate of 3.5%. When the a of pitted fruit, 100% of pitted cherries were detected with a orientation is controlled after pitting, total error is reduced to 1%.
- Published
- 2013
29. Advances in automated nut sorting
- Author
-
Ronald P. Haff, Natsuko Toyofuku, and T. C. Pearson
- Subjects
Nut ,Engineering ,business.industry ,Food processing ,Sorting ,Operations management ,Biochemical engineering ,business - Abstract
Nuts in general and tree nuts in particular are a high value crop in many countries. Products with defects, contamination, insects or fungal damage can cause serious losses to producers, so almost all products are subjected to some level of sorting to remove these undesirable products. This chapter focuses on post harvest processing, specifically the advances in the removal of undesired nuts and contaminants from a nut processing stream via automated sorting. Specifically, we will discuss the advantages and disadvantages of computer- and acoustics-based sorting systems.
- Published
- 2013
30. Machine Vision Detection of Early Split Pistachio Nuts
- Author
-
David C. Slaughter and T. C. Pearson
- Subjects
Nut ,Machine vision ,digestive, oral, and skin physiology ,Botany ,food and beverages ,Longitudinal axis ,Pistachio Nuts ,Geodesy ,Agricultural and Biological Sciences (miscellaneous) ,Geology - Abstract
Computer vision was used to detect early split lesions on the hull of pistachio nuts. Gray scale intensity profiles were computed across the width of the nut (perpendicular to the suture along the longitudinal axis). If the profile crossed an early split lesion, a deep and narrow valley on the profile at the early split location was observed. Profiles were computed every 0.5 mm along the longitudinal axis of the nut and the number of adjacent profiles with deep and narrow valleys was recorded. Early split nuts contained a significantly higher count of these adjacent profiles than normal nuts. Combining unhulled nut cross-sectional area with the adjacent profile data, 100% of the early split nuts and 99% of the normal nuts were correctly classified of the total of 180 nuts tested.
- Published
- 1996
31. Regulation of immunostimulatory function and costimulatory molecule (B7-1 and B7-2) expression on murine dendritic cells
- Author
-
C P Larsen, S C Ritchie, R Hendrix, P S Linsley, K S Hathcock, R J Hodes, R P Lowry, and T C Pearson
- Subjects
Immunology ,Immunology and Allergy - Abstract
Dendritic cells (DC) play a critical role in the initiation of T cell-mediated immune responses, and express costimulatory molecules that are required for optimal activation of unprimed T cells. Studies on the regulation of the costimulatory molecules on DC have produced evidence from several systems that GM-CSF can up-regulate expression of CTLA4 counter receptor (CTLA4-CR) (but not intercellular adhesion molecule 1 (ICAM-1) and heat stable Ag (HsAg)) on DC. This is demonstrated on splenic DC, Langerhans cells, kidney DC in culture, and in a skin-explant culture system, in which the increased expression of CTLA4-CR on Langerhans cells (LC) occurs concomitantly with their migration out of skin. Interestingly, despite the ability of both GM-CSF and IFN-gamma to increase CTLA4-CR and maintain similar levels of ICAM-1, HsAg, and MHC molecule expression, the functional consequences of these cytokines on splenic DC are distinctly different. GM-CSF enhances the ability of DC to stimulate both T cell proliferation and cytokine release, whereas IFN-gamma causes no increase in immunostimulatory function. Further analysis of the CTLA4-CR on these cell populations by using the GL-1 and IG10 mAbs has shown that GM-CSF-cultured DC express high levels of both B7-1 and B7-2, whereas IFN-gamma-cultured DC express increased levels of only B7-2. These results suggest that optimal stimulation of unprimed T cells to proliferate and release cytokines may require participation of both of these CTLA4 counter receptors, and confirm the importance of GM-CSF for the maturation of DC into potent stimulators of T cell activation.
- Published
- 1994
32. The in vitro effects of stem cell factor, interleukin 3 and granulocyte-macrophage colony stimulating factor on haemopoietic progenitor cells from premature infants
- Author
-
R. Chung, N. B. Westwood, A. J. B. Emmerson, and T. C. Pearson
- Subjects
medicine.medical_specialty ,Stem cell factor ,Biology ,Hematopoietic Cell Growth Factors ,Colony-Forming Units Assay ,Hemoglobins ,hemic and lymphatic diseases ,Internal medicine ,medicine ,Humans ,Progenitor cell ,Cells, Cultured ,Interleukin 3 ,Erythroid Precursor Cells ,Colony-forming unit ,Stem Cell Factor ,Macrophages ,Infant, Newborn ,Granulocyte-Macrophage Colony-Stimulating Factor ,Hematology ,Hematopoietic Stem Cells ,Colony-stimulating factor ,Globins ,Granulocyte macrophage colony-stimulating factor ,Endocrinology ,Erythropoietin ,embryonic structures ,Interleukin-3 ,Stem cell ,Infant, Premature ,Granulocytes ,medicine.drug - Abstract
Summary. Circulating haemopoietic progenitor cells from premature infants were assessed for their ability to respond to interleukin 3, granulocyte-macrophage colony stimulating factor and stem cell factor (SCF) in vitro. All three cytokines increased the number of colonies derived from burst forming units erythroid (BFU-E), colony forming units granulocyte-macrophage (CFU-GM) and multi-lineage progenitors (CFU-Mix) grown in the presence of erythropoietin (Epo). The size and haemoglobin content of BFU-E derived colonies also increased in the presence of the cytokines. Of those tested, SCF was found to be the most potent additive to Epo for the enhanced growth of BFU-E and CFU-Mix. In short-term liquid cultures without Epo, SCF alone induced globin synthesizing cells. Progenitors from premature infants were at least as responsive to all three cytokines as those from healthy adults. The use of SCF in combination with Epo in the prevention or treatment of anaemia in premature infants warrants further investigation.
- Published
- 1994
33. Physical Properties of Pistachio Nuts
- Author
-
H. E. Studer, T. C. Pearson, and David C. Slaughter
- Subjects
Nut ,Aflatoxin ,Horticulture ,biology ,Chemistry ,Aspergillus flavus ,Food science ,Pistachio Nuts ,biology.organism_classification ,Agricultural and Biological Sciences (miscellaneous) - Abstract
Physical properties of pistachio nuts were evaluated to determine distinguishable characteristics of early split pistachio nuts. The hulls of early split pistachios abnormally split open several weeks before harvest, making the kernel more vulnerable to the aflatoxin producing mold Aspergillus flavus. The most distinguishing features of early split pistachio nuts were found to be shell staining and hull adhesion tendencies. Using shell stain characteristics and shell dimensions, an algorithm was developed that correctly classified 90% of the early splits, and 97% of the normal nuts. When unhulled nuts were placed into a tumbler, 98% of the early split nuts kept their hulls while 95% of the normal nuts were hulled. A mechanical separation device was constructed that successfully separated 90% of the early split nuts and only 5% of the nonsplit nuts from the rest of the samples. Nut mass, length, width, and height are significantly different between early split nuts and normal nuts, however, these properties cannot be used to accurately classify the nuts into split types.
- Published
- 1994
34. Double blind trial of recombinant human erythropoietin in preterm infants
- Author
-
H. J. Coles, A. J. B. Emmerson, C. M. M. Stern, and T. C. Pearson
- Subjects
Male ,medicine.medical_specialty ,Pediatrics ,Anemia ,Injections, Subcutaneous ,Infant, Premature, Diseases ,Placebo ,Anemia of prematurity ,Gastroenterology ,Drug Administration Schedule ,law.invention ,Double-Blind Method ,Randomized controlled trial ,law ,Internal medicine ,medicine ,Humans ,Erythropoietin ,Anemia, Neonatal ,business.industry ,Infant, Newborn ,medicine.disease ,Recombinant Proteins ,Clinical trial ,Pediatrics, Perinatology and Child Health ,Gestation ,Erythropoiesis ,Female ,business ,Infant, Premature ,Research Article ,medicine.drug - Abstract
Twenty four infants between 27 and 33 weeks' gestation were recruited into a double blind study to investigate the use of recombinant human erythropoietin (r-HuEpo) for the prevention of anaemia of prematurity. Between 50 and 150 U of r-HuEpo (n = 16) or placebo was administered subcutaneously twice a week from 7 days of age until discharge. There was a significant increase in the reticulocyte count in infants receiving r-HuEpo sustained from the second week of treatment until discharge compared with placebo. There was a reduction in the number of transfusions required in the r-HuEpo group with only 47% requiring a transfusion compared with 87% in the placebo group. During treatment with r-HuEpo there was a significant rise in the red cell folate concentration, a significant fall in the ferritin concentration, and a significantly higher percentage of haemoglobin F at discharge suggesting active erythropoiesis. The study provides strong evidence for the efficacy of r-HuEpo in stimulating erythropoiesis and reducing the requirement for transfusions for anaemia of prematurity.
- Published
- 1993
35. The in vitro effect of high-dose recombinant human erythropoietin on granulocyte-macrophage colony production in premature infants using a defined serum deprived cell culture system
- Author
-
A. J. B. Emmerson, N. B. Westwood, C. S. Ward, and T. C. Pearson
- Subjects
Male ,medicine.medical_specialty ,Myeloid ,Biology ,Granulocyte ,Culture Media, Serum-Free ,Internal medicine ,Granulocyte Colony-Stimulating Factor ,medicine ,Humans ,Erythropoietin ,Cells, Cultured ,Interleukin 3 ,Colony-forming unit ,Dose-Response Relationship, Drug ,Macrophages ,Infant, Newborn ,Granulocyte-Macrophage Colony-Stimulating Factor ,Cell Differentiation ,Hematology ,Hematopoietic Stem Cells ,Colony-stimulating factor ,Recombinant Proteins ,Hematopoiesis ,Granulocyte colony-stimulating factor ,medicine.anatomical_structure ,Endocrinology ,Cell culture ,Female ,Interleukin-3 ,Cell Division ,Infant, Premature ,Granulocytes ,medicine.drug - Abstract
Recent reports of neutropenia associated with the use of recombinant human erythropoietin (r-HuEpo) in preterm infants with the anaemia of prematurity have raised concern over the clinical use of this hormone. The present studies were undertaken to determine whether high-dose r-HuEpo has an effect on granulocyte production in vitro. The studies used a serum deprived, optimized semi-solid cell culture system to investigate the effect of lineage specific and non-specific granulocyte and erythroid colony stimulating factors on circulating peripheral blood granulocyte-macrophage colony forming units (CFU-GM), erythroid burst forming units (BFU-E) and multilineage colonies (CFU-Mix) from nine premature infants and seven healthy adults. CFU-GM were grown in the presence of interleukin 3 (IL3) 8 ng/ml, granulocyte-macrophage colony stimulating factor (GM-CSF) 20 ng/ml and granulocyte colony stimulating factor (G-CSF) 15 ng/ml alone and combinations of G-CSF with GM-CSF or IL3. The number, size and differentiation of CFU-GM colonies were then analysed in the presence and absence of high dose r-HuEpo (4 U/ml). High-dose r-HuEpo did not exert any significant modulatory effects on the number of CFU-GM colonies produced in the presence of IL3, GM-CSF and G-CSF alone or in combination. The number of cells within each CFU-GM colony did not change significantly, nor was there a significant change in the degree of differentiation. The combined number of BFU-E. CFU-GM and CFU-Mix colonies increased with r-HuEpo in both adults (1·8x) and preterm infants (1·4x), almost exclusively due to an increase in BFU-E derived colonies. Thus, no evidence was found for an r-HuEpo mediated redirection of multipotential haemopoietic stem cells into committed erythroid precursors at the expense of myeloid precursors.
- Published
- 1992
36. Apparent polycythaemia
- Author
-
T C, Pearson
- Subjects
Hematocrit ,Oncology ,Reference Values ,Risk Factors ,Humans ,Thrombosis ,Polycythemia ,Hematology - Abstract
Patients with apparent polycythaemia are characterised by a raised packed cell volume (PCV; males above 0.51, females above 0.48) but normal red cell mass (RCM; less than 25% greater than predicted). Prediction and interpretation of RCM and PV should be based on height and weight, since the use of body weight alone is misleading. Patients with PCV values up to 0.60 may have apparent polycythaemia but only 18% have a reduced PV (relative polycythaemia). Therefore, the most common cause of the raised PCV is a change in RCM and/or PV within their normal ranges. The clinical associations and possible causes for the RCM/PV changes include male sex, obesity, dehydration, diuretics, smoking, hypertension, alcohol, arterial oxygen desaturation, renal disease and increased catecholamine levels. Retrospective studies of patients with apparent polycythaemia and information from other groups of polycythaemic patients suggest an increased risk of vascular occlusion, although other factors, such as hypertension and smoking, are also involved. Proposed management includes modification of possible underlying causes and examination for risk factors for vascular occlusion. In patients with PCV levels chronically above 0.54 venesection should be used, but patients with PCV values below this level should only be venesected if they are considered to be at risk of vascular occlusion. The suggested target value for PCV for venesected patients is 0.45 or below.
- Published
- 1991
37. Identification Of Damaged Wheat Kernels And Cracked-Shell Hazelnuts With Impact Acoustics Time-Frequency Patterns
- Author
-
T. C. Pearson, Ibrahim Onaran, A.H. Tewfik, Yasemin Yardimci, Ahmet Enis Cetin, Nuri F. Ince, Habil Kalkan, and Çetin, A. Enis
- Subjects
Kernel classification ,Frequency band ,Acoustics ,Biomedical Engineering ,Soil Science ,Forestry ,Linear discriminant analysis ,Impact acoustics ,Time–frequency analysis ,Data acquisition ,Discriminative model ,Discriminant ,Principal component analysis ,Cluster analysis ,Adaptive time-frequency analysis ,Food kernel inspection ,Agronomy and Crop Science ,Food Science ,Mathematics - Abstract
A new adaptive time-frequency (t-f) analysis and classification procedure is applied to impact acoustic signals for detecting hazelnuts with cracked shells and three types of damaged wheat kernels. Kernels were dropped onto a steel plate, and the resulting impact acoustic signals were recorded with a PC-based data acquisition system. These signals were segmented with a flexible local discriminant bases (F-LDB) procedure in the time-frequency plane to extract discriminative patterns between damaged and undamaged food kernels. The F-LDB procedure requires no prior knowledge of the relevant time or frequency indices of the impact acoustics signals for classification. The method automatically finds all crucial time-frequency indices from the training data by combining local cosine packet analysis and a frequency axis clustering approach, which supports individual time and frequency band adaptation. Discriminant features are extracted from the adaptively segmented acoustic signal, sorted according to a Fisher class separability criterion, post-processed by principal component analysis, and fed to a linear discriminant classifier. Experimental results establish the superior performance of the proposed approach when compared to prior techniques reported in the literature or used in the field. The new approach separated damaged wheat kernels (IDK, pupal, and scab) from undamaged wheat kernels with 96%, 82%, and 94% accuracy, respectively. It also separated cracked-shell hazelnuts from those with undamaged shells with 97.1% accuracy. The adaptation capability of the algorithm to the time-frequency patterns of signals makes it a universal method for food kernel inspection that can resist the impact acoustic variability between different kernel and damage types.
- Published
- 2008
38. Discrimination between closed-and open-shell (Turkish) pistachio nuts using undecimated wavelet packet transform
- Author
-
Nuri F. Ince, Ahmet Enis Cetin, A.H. Tewfik, Fikri Goksu, Ibrahim Onaran, T. C. Pearson, and Çetin, A. Enis
- Subjects
Engineering ,Signal processing ,business.industry ,Feature extraction ,Bioengineering ,Pattern recognition ,Undecimated wavelet packet transform ,Classification ,Signal ,Wavelet packet decomposition ,Data set ,Impact acoustic ,Discriminative model ,Feature (computer vision) ,Turkish pistachios ,Artificial intelligence ,business ,Pruning (morphology) ,Food Science ,Biotechnology - Abstract
Due to low consumer acceptance and the possibility of immature kernels, closed-shell pistachio nuts should be separated from open-shell nuts before reaching the consumer. A system using impact acoustics as a means of classifying closed-shell nuts from open-shell nuts has already been shown to be feasible and have better discrimination performance than a mechanical system. The accuracy of an impact acoustics based system is determined by the signal processing and feature extraction procedures. In this article, a new time-frequency plain feature extraction and classification algorithm was developed to discriminate between open- and closed-shell pistachio nuts produced in the Gaziantep region of Turkey. The proposed approach relies on the analysis of the impact acoustics signal of pistachio nuts, which are emitted from their impact with a steel plate after dropping from a certain height. Features are extracted by decomposing the acoustic signals into time and frequency components, using double-tree undecimated wavelet packet transform. The most discriminative features from the dual tree nodes are selected by a wrapper strategy that includes the structural pruning of the double-tree feature dictionary. The proposed approach requires no prior knowledge of the relevant time or frequency content of the acoustic signals. The algorithm used a small number of features and achieved a classification accuracy of 91.7% on the validation data set, while separating the closed shells from the open ones. A previously implemented algorithm, which uses maximum signal amplitude, absolute integration, and gradient features, achieved 82% classification accuracy on the same dataset. The results show that the time-frequency features extracted from impact acoustics can be used successfully for classification of open- and closed-shell Turkish pistachios.
- Published
- 2008
39. A New PCA/ICA Based Feature Selection Method
- Author
-
Zehra Cataltepe, Hakh Murat Genc, and T. C. Pearson
- Subjects
ComputingMethodologies_PATTERNRECOGNITION ,business.industry ,Dimensionality reduction ,Principal component analysis ,Feature extraction ,Entropy (information theory) ,Feature selection ,Time critical ,Pattern recognition ,Artificial intelligence ,business ,Independent component analysis ,Mathematics - Abstract
Dimensionality reduction algorithms help reduce the classification time and sometimes the classification error of a classifier (Yang, et al., 1997). For time critical applications, in order to have reduction in the feature acquisition phase, feature selection methods are more preferable to dimensionality reduction methods, which require measurement of all inputs. Traditional feature selection methods, such as forward or backward feature selection, are costly to implement. In this study, we introduce a new feature selection method that decides on which features to retain, based on how PCA (principal component analysis) or ICA (independent component analysis) (Hyvarinen and Oja, 1999) values those features. We compare the accuracy of our method to backward and forward feature selection with the same number of features selected and PCA and ICA using the same number of principal and independent components. For our experiments, we use spectral measurement data taken from corn kernels infested and not infested by fungi.
- Published
- 2007
40. Organ donation and utilization, 1995-2004: entering the collaborative era
- Author
-
J. Burdick, P. W. Nelson, W. H. Marks, D. Wagner, T. C. Pearson, Mary K. Guidinger, J. P. Orlowski, and Joshua J. McGowan
- Subjects
medicine.medical_specialty ,Tissue and Organ Procurement ,Best practice ,Disease ,Living donor ,History, 21st Century ,Annual growth % ,Ethnicity ,Living Donors ,Immunology and Allergy ,Medicine ,Humans ,Pharmacology (medical) ,Organ donation ,Intensive care medicine ,Transplantation ,business.industry ,Donation after cardiac death ,Organ Transplantation ,History, 20th Century ,Tissue Donors ,United States ,Surgery ,Donation ,Tissue and Organ Harvesting ,business - Abstract
Continued progress in organ donation will help enable transplantation to alleviate the increasing incidence of end-stage organ disease. This article discusses the implementation and effect of the federally initiated Organ Donation Breakthrough Collaborative; it then reviews organ donation data, living and deceased, from 1995 to 2004. It is the first annual report of the Scientific Registry of Transplant Recipients to include national data following initiation of the collaborative in 2003. Prior to that, annual growth in deceased donation was 2%-4%; in 2004, after initiation of the collaborative, deceased donation increased 11%. Identification and dissemination of best practices for organ donation have emphasized new strategies for improved consent, including revised approaches to minority participation, timing of requests and team design. The number of organs recovered from donation after cardiac death (DCD) grew from 64 in 1995 to 391 in 2004. While efforts are ongoing to develop methodologies for identifying expanded criteria donors (ECD) for organs other than kidney, it is clear DCD and ECD raise questions regarding cost and recovery. The number of living donor organs increased from 3493 in 1995 to 7002 in 2004; data show trends toward more living unrelated donors and those providing non-directed donations.
- Published
- 2006
41. Identification of insect damaged wheat kernels using transmittance images
- Author
-
Enis A. Cetin, Zehra Cataltepe, T. C. Pearson, and Çetin, A. Enis
- Subjects
Radial basis function network ,Feature extraction ,Image processing ,Histogram ,Kernels ,Electrical and Electronic Engineering ,Radial function networks ,Image resolution ,Mathematics ,Mathematical models ,Contextual image classification ,business.industry ,Sensors ,Markov processes ,food and beverages ,Pattern recognition ,Computer simulation ,Image transmittance ,Mobile telecommunication systems ,Feature (computer vision) ,Pixel intensity ,Artificial intelligence ,False positive rate ,business ,Robustness (control systems) ,Algorithms - Abstract
Date of Conference: 24-27 October 2004 Conference Name: International Conference on Image Processing, IEEE 2004 We used transmittance images and different learning algorithms to classify insect damaged and un-damaged wheat kernels. Using the histogram of the pixels of the wheat images as the feature, and the linear model as the learning algorithm, we achieved a False Positive Rate (1-specificity) of 0.2 at the True Positive Rate (sensitivity) of 0.8 and an Area Under the ROC Curve (AUC) of 0.86. Combining the linear model and a Radial Basis Function Network in a committee resulted in a FP Rate of 0.1 at the TP Rate of 0.8 and an AUC of 0.92.
- Published
- 2005
42. Hull Adhesion Characteristics of Early-split and Normal Pistachio Nuts
- Author
-
T. C. Pearson, H. E. Studer, and David C. Slaughter
- Subjects
Condensed Matter::Soft Condensed Matter ,Nut ,High Energy Physics::Theory ,General Relativity and Quantum Cosmology ,Horticulture ,Hull ,General Engineering ,Mineralogy ,Adhesion ,Computer Science::Computational Geometry ,Pistachio Nuts ,Mathematics::Symplectic Geometry ,Mathematics - Abstract
The hull adhesion properties of early-split and normal pistachio nuts were studied to determine the feasibility of separating early-split nuts from normal nuts by their hulling characteristics. The hulls of pistachio nuts were found to adhere more tightly to the shells of early-split nuts than to normal nuts. Laboratory hulling tests on pistachio nuts harvested in 1993 indicated that under controlled conditions, 98% of the normal nut hulls were removed while only 9% of the early-split hulls were removed.
- Published
- 1996
43. INSECT EGG COUNTING ON MASS REARING OVIPOSITION PADS BY IMAGE ANALYSIS
- Author
-
E. L. Miller, T. C. Pearson, A. P. Mossman, R. H. Edwards, Pauline C. Yu, and D. F. Wood
- Subjects
body regions ,Mean squared error ,Histogram ,Statistics ,General Engineering ,Insect egg ,Regression analysis ,Biology ,Egg count ,biology.organism_classification ,Simulation ,Pink bollworm - Abstract
Variability of egg quantities laid on rearing trays during large–scale production of sterile insects can cause economic losses due to overfeeding or underfeeding. In addition, quality control measures to monitor egg numbers are both tedious and laborious. Methods were developed to count pink bollworm egg numbers on oviposition pads using histogram features from 10–bit grayscale images of the pads. Egg count prediction by regression analysis produced highly significant predictive model equations when individual histogram bin values or cumulative histogram bins (multiple thresholds) were used as independent variables. Models using cumulative histogram bin values appeared more robust as the mean squared error values were slightly lower. There was little difference in prediction results when using camera resolutions of 183, 139, and 94 pixels/cm. Automation of this methodology may allow a mass rearing facility to obtain oviposition pad segments with the desired number of eggs 10%, increasing insect yield and/or quality and minimizing diet costs. In addition, the methodology will allow entomologists to quickly and accurately count eggs from laboratory or large–scale experiments.
- Published
- 2002
44. Analysis of the CD40 and CD28 pathways on alloimmune responses by CD4+ T cells in vivo
- Author
-
A W, Bingaman, J, Ha, M M, Durham, S Y, Waitze, C, Tucker-Burden, S R, Cowan, T C, Pearson, and C P, Larsen
- Subjects
CD4-Positive T-Lymphocytes ,Graft Rejection ,Male ,Mice, Knockout ,Isoantigens ,Mice, Inbred BALB C ,Myocardium ,CD40 Ligand ,Immunity ,Skin Transplantation ,Lymphocyte Activation ,Mice, Inbred C57BL ,Mice ,CD28 Antigens ,CD4 Antigens ,Animals ,Cytokines ,Heart Transplantation ,Transplantation, Homologous ,CD40 Antigens ,Cell Division - Abstract
Blockade of the CD40 and CD28 pathways is a powerful strategy to inhibit CD4-mediated alloimmune responses. In this study, we examine the relative roles of the CD40 and CD28 pathways on CD4-mediated allograft rejection responses, and further characterize the role of these pathways on CD4+ T-cell activation, priming for cytokine production, and cell proliferation in response to alloantigen in vivo.BALB/c skin allografts were transplanted onto C57BL/6 Rag 1-/- recipients reconstituted with CD4 cells from CD28-/- or CD40L-/- donors. The popliteal lymph node assay was used to study the role of these pathways on CD4-cell activation and priming in vivo. To investigate the role of CD40 and CD28 blockade on CD4-cell proliferation, the fluorescein dye carboxyfluorescein diacetate succinimidyl ester was used. We performed heterotopic cardiac transplantation using CD40-/- mice to evaluate the role of CD40 on donor versus recipient cells in CD4-mediated rejection.B6 Rag 1-/- recipients reconstituted with CD28-/- CD4+ T cells acutely rejected allografts (median survival time 15 days), whereas recipients reconstituted with CD40L-/- CD4+ T cells had significantly prolonged survival of BALB/c skin grafts (MST 71 days). CD40L blockade was equivalent to or inferior to CD28 blockade in inhibition of in vivo CD4-cell activation, priming for cytokine production, and proliferation responses to alloantigen. BALB/c recipients depleted of CD8 cells promptly rejected donor B6 CD40-/- cardiac allografts, whereas B6 CD40-/- recipients depleted of CD8 cells had significantly prolonged survival of BALB/c wild-type cardiac allografts.The CD40/CD40L pathway, but not the CD28/B7 pathway, is critical for CD4-mediated rejection responses, however, the responsible mechanisms remain unclear.
- Published
- 2001
45. Gene expression analysis in human renal allograft biopsy samples using high-density oligoarray technology
- Author
-
E, Akalin, R C, Hendrix, R G, Polavarapu, T C, Pearson, J F, Neylan, C P, Larsen, and F G, Lakkis
- Subjects
Adult ,Graft Rejection ,Male ,Receptors, Antigen, T-Cell, alpha-beta ,T-Lymphocytes ,Gene Expression ,Middle Aged ,Phosphoproteins ,Chemokine CXCL9 ,Kidney Transplantation ,Case-Control Studies ,Chemokines, CC ,Chemokine CCL19 ,Humans ,Intercellular Signaling Peptides and Proteins ,ATP-Binding Cassette Transporters ,Female ,RNA, Messenger ,ATP Binding Cassette Transporter, Subfamily B, Member 2 ,Chemokines, CXC ,Oligonucleotide Array Sequence Analysis - Abstract
High-density oligoarray technology is a novel method for screening the expression of thousands of genes in a small tissue sample. Oligoarray analysis of genes expressed during human renal allograft rejection has not been reported previously.Seven human renal allograft biopsies with histologic evidence of acute cellular rejection and three renal allograft biopsies without evidence of rejection (control) were analyzed for the expression of 6800 human genes using high-density oligoarrays (GeneChip, Affymetrix, Santa Clara, CA). Quantitative expression of gene transcripts was determined and a comparison analysis between acute rejection and control biopsy samples was performed. Up-regulation of a specific gene transcript during acute rejection was considered to be significant if transcript abundance increased fourfold or more relative to control biopsy samples.Comparison analysis revealed that between 32 and 219 gene transcripts are up-regulated (fourfold) during acute rejection. Of these transcripts, only four (human monokine induced by interferon-gamma, T-cell receptor active beta-chain protein, interleukin-2 stimulated phosphoprotein, and RING4 (a transporter involved in antigen presentation)) were consistently up-regulated in each acute rejection sample relative to at least two of three control biopsy samples. Six other genes were up-regulated in six of seven acute rejection samples. These were interferon-stimulated growth factor-3, complement factor 3, nicotinamide N-methyltransferase, macrophage inflammatory protein-3beta, myeloid differentiation protein, and CD18. Only two gene transcripts were down-regulated in five of seven acute rejection samples. Significant up-regulation of cytotoxic T-cell effector molecules, previously reported as markers of acute renal rejection in humans, was not detected.High-density oligoarray technology is useful for screening gene expression in transplanted tissues undergoing acute rejection. Because this method does not rely on a priori knowledge of which genes are involved in acute rejection, it is likely to yield novel insights into the mechanisms and diagnosis of rejection.
- Published
- 2001
46. Polycythemia vera: analysis of DNA from blood granulocytes using comparative genomic hybridization
- Author
-
N B, Westwood, A M, Gruszka-Westwood, S, Atkinson, and T C, Pearson
- Subjects
Adult ,Chromosome Aberrations ,Male ,Cytogenetic Analysis ,Humans ,Nucleic Acid Hybridization ,Female ,Middle Aged ,Polycythemia Vera ,Aged ,Granulocytes - Abstract
The diagnosis of polycythemia vera (PV) is supported by the finding of an abnormal karyotype in patients with erythrocytosis. However, most PV patients have normal marrow cytogenetics at presentation and there is reluctance to use this test routinely. Comparative genomic hybridization (CGH) is a cytogenetic screening technique that analyzes interphase cells. This approach offers practical advantages over conventional cytogenetics and interphase fluorescence in-situ hybridization (IFISH). We have therefore evaluated the diagnostic utility of CGH applied to blood granulocytes in PV.Blood granulocytes from 17 PV patients were analyzed using CGH and the results compared with those from previous conventional cytogenetics and IFISH studies.Three patients had abnormal CGH profiles. One case had gain of 9p. This patient had normal IFISH results using a centromere-9 probe. The second case had complete gain of chromosomes 8 and 9 and the third had complete gain of chromosome 9, all confirmed by IFISH: Cytogenetics had not been performed in two of these cases and had failed in the third. Three cases with 20q deletion according to cytogenetics and/or IFISH, were normal by CGH. The remaining subjects were normal by all methods.CGH analysis of blood granulocytes can detect the chromosome gains commonly observed in PV. However, CGH cannot be relied on to detect 20q deletions, which are the most frequent cytogenetic abnormality in PV. Thus, CGH has a role in the diagnosis and follow-up of PV patients, but must be used in conjunction with other methods.
- Published
- 2001
47. Hemorheology in the erythrocytoses
- Author
-
T C, Pearson
- Subjects
Hematocrit ,Hemorheology ,Humans ,Polycythemia ,Blood Viscosity ,Hypoxia ,Blood Flow Velocity - Abstract
n vitro, rheological studies establish that whole blood viscosity and yield stress are high in patients with an erythrocytosis. However, a number of factors ensure that these patients, under physiological conditions, do not show the clinical features observed in other hyperviscosity states. These include red cell axial migration in flowing blood and "plug flow" in the largest vessels. In addition, a small increase in vessel diameter leads to large increases in blood flow, and generally high blood flows produce the lowest blood viscosity values. The increased hemoglobin levels and the increase in oxygen-carrying capacity at high hematocrit values compensate for the tissue hypoxia. In the "non-hypoxemic" erythrocytoses (polycythemia vera, idiopathic and apparent erythrocytosis), there is an increased incidence of vascular occlusion in untreated patients. The reasons for this include reduced peripheral blood flow, increased platelet-vessel wall interactions, and the demonstrated in vitro hyperviscosity which comes into play with abnormally low flow, seen in vivo under pathological conditions. In the erythrocytosis of hypoxemic lung disease and its associated hypoxemia, pulmonary vasoconstriction enhances susceptibility to hyperviscosity effects in particular. Moreover, the vasoconstriction caused by the hypoxemia prevents the normal adaptive changes of increased vessel diameter. Microcytic hypochromic red cell changes of iron deficiency do not cause a higher viscosity value at any given hematocrit value compared with normal red cells. However, in hypoxemic states oxygen-carrying capacity should be maximized, since the hemoglobin value is disproportionately lower at any given hematocrit in the presence of microcytic hypochromic cells compared with normal red cells.
- Published
- 2001
48. Automated sorting of almonds with embedded shell by laser transmittance imaging
- Author
-
T. C. Pearson and Richard Young
- Subjects
business.industry ,Fragment (computer graphics) ,Real-time computing ,Nuclear Theory ,General Engineering ,Shell (structure) ,Process (computing) ,Sorting ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Laser ,Computer algorithm ,law.invention ,Optics ,law ,Data_FILES ,Physics::Atomic and Molecular Clusters ,Transmittance ,business ,Biological system ,Computer hardware ,Kernel (category theory) ,Mathematics ,Block (data storage) - Abstract
A quality control problem for the almond industry is that of shell fragments lodging into kernels when kernels are being hulled and shelled. The occurrence of kernels with embedded shell is rare with only about 0.1% of shelled kernels exhibiting this problem. However, the incidence of shell fragments lodging into kernels has been increasing over the past several years. Thus the industry is in need of a method for removing these kernels from the process stream. A prototype device has been constructed to automatically detect and separate kernels with embedded shell fragments. This device images laser light transmitted through the kernel. Shell fragments block nearly all the transmitted light and appear as a very dark spot in the image. A computer algorithm was developed to detect these dark spots and activate an air valve to divert kernels with embedded shell from the process stream. Using a one pass sorting operation, approximately 83% of the kernels with embedded shell were detected while 11% of the kernels with no embedded shell were incorrectly classified as having embedded shell. Running the rejects of the first sorting pass through a second time can recover approximately 46% of kernels with no embedded shell. Kernels classified as having embedded shell can be chopped or sliced to remove the shell fragment. The sorting device has an inspection rate of approximately 40 kernels per second or 100 kg per hour.
- Published
- 2001
49. The incidences of trisomy 8, trisomy 9 and D20S108 deletion in polycythaemia vera: an analysis of blood granulocytes using interphase fluorescence in situ hybridization
- Author
-
N B, Westwood, A M, Gruszka-Westwood, C E, Pearson, C F, Delord, A R, Green, B J, Huntly, A, Lakhani, M F, McMullin, and T C, Pearson
- Subjects
Adult ,Aged, 80 and over ,Genetic Markers ,Male ,Trisomy ,Middle Aged ,Cytogenetic Analysis ,Humans ,Female ,Chromosomes, Human, Pair 9 ,Interphase ,Polycythemia Vera ,Gene Deletion ,In Situ Hybridization, Fluorescence ,Aged ,Chromosomes, Human, Pair 8 ,Granulocytes - Abstract
We have used interphase fluorescence in situ hybridization (IFISH) to detect trisomy 8, trisomy 9 and 20q deletion in circulating granulocytes from patients with polycythaemia vera (PV). Out of 64 PV patients, 15 (23%) exhibited an abnormality. Two patients had trisomy 9, three had trisomy 8 and 10 patients had hemizygous deletion of D20S108 (a locus in the 20q common deleted region). Aberrant nuclei ranged from 10% to 80% in these 15 cases. There was no correlation between the presence of a marker and sex, age, interval between presentation and IFISH analysis, neutrophil or platelet count or therapy. Conventional marrow cytogenetic karyotype results were available in 23 cases and there was concurrence between these and blood IFISH in 16 cases (13 normal and three with 20q/D20S108 deletion by both methods). Three patients with D20S108 deletion by IFISH were normal by previous marrow cytogenetic testing and four cases with 20q deletion by previous marrow cytogenetics had normal blood granulocytes according to IFISH. Thus, we confirm that trisomies 8 and 9 and deletion of 20q are diagnostically useful markers of PV. IFISH analysis of blood granulocytes is a practical method for detecting these markers, but as an adjunct to, not as a substitute for, conventional marrow cytogenetics.
- Published
- 2000
50. Analysis of a single-center experience with mycophenolate mofetil based immunosuppression in renal transplantation
- Author
-
H L, Triemer, T C, Pearson, K L, Odom, and C P, Larsen
- Subjects
Adult ,Graft Rejection ,Immunosuppression Therapy ,Male ,Survival Rate ,Graft Survival ,Humans ,Female ,Mycophenolic Acid ,Kidney Transplantation ,Immunosuppressive Agents ,Retrospective Studies - Abstract
Acute rejection continues to be a major clinical issue in renal transplantation. Three large multicenter trials have demonstrated a 50% decline in biopsy-proven rejection when mycophenolate mofetil (MMF) was given to renal transplant recipients with corticosteroids and cyclosporine. The purpose of this study was to compare the 6-month outcome of renal transplant recipients using MMF and non-MMF based immunosuppression protocols over a 4-year period at a single center.This retrospective study analyzed three patient groups defined by their immunosuppression protocol. The first group included patients who received a quadruple immunosuppression regimen of anti-lymphocyte induction (ATG), cyclosporine (CYA), azathioprine (AZA), and corticosteroids (CCS), and were transplanted between October 1993 and May 1995 (AZA group). The second group included patients who received a triple immunosuppression regimen of CYA, MMF, and CCS, and were transplanted between June 1995 and May 1996 (MMF group). The third group included patients who were transplanted between January 1997 and December 1997, and received an immunosuppression regimen of CYA and MMF with a reduced CCS dosing schema (reduced steroid group (RST)). Data were collected from a retrospective review of inpatient and outpatient clinical records.A total of 325 patients were included in the study (106 AZA, 106 MMF, 113 RST). The demographic characteristics of the three groups were similar; however, the mean donor age for the AZA group was 40+/-15.1 years versus 33+/-14.1 years and 34+/-13.1 years for the MMF and RST groups, respectively (p0.043). The incidence of acute, biopsy-proven rejection at 6 months was significantly less in the MMF group when compared with the AZA group [16 (15.1%) versus 35 (33%) patients, p = 0.002]. However, the incidence of acute, biopsy-proven rejection in the RST group (35 patients, 31%) was similar to that of the AZA group. Kaplan-Meier estimates for the cumulative incidence of acute rejection demonstrated a significant difference between the MMF group and the other two groups (p = 0.0059). The AZA group had more severe rejection as demonstrated by the more frequent use of antilymphocyte therapy for rejection treatment (68.4% episodes) compared with the MMF (38.9%) and RST (47.6%) groups. After 6 months of follow-up, 11 patients had lost their grafts (8, AZA; 1, MMF; 2, RST). One patient died in each of the AZA and RST groups due to hemorrhage and a pulmonary embolus, respectively. Four AZA patients were diagnosed with a malignancy (three post-transplant lymphoproliferative disorder, one squamous skin cell carcinoma) compared with 2 MMF patients (prostate cancer, basal skin cell carcinoma) and no RST patients. Herpes zoster was the only infection that occurred more frequently in the MMF group (p = 0.03). No other differences in infection rates were noted among the three groups. The initial length of hospital stay declined significantly over the 4-year study period [11+/-4.3 d (AZA), 7.0+/-4.0 d (MMF), 6.2+/-3.3 d (RST), p0.001]. Total number of hospital days for the first 6 months also followed a similar declining pattern. Despite using intravenous cyclosporine immediately post-transplant in the MMF and RST groups, the incidence of delayed graft function was similar among the three groups. Average serum creatinine at 1 month was significantly lower in the MMF group (p = 0.008), but no difference was noted at 3 and 6 months when compared with the AZA and RST groups.This retrospective analysis indicates that MMF is an effective immunosuppressant. Decreased length of stay and less steroid resistant rejections with MMF is favorable for decreased hospital costs. However, the rebound in rejection rate with the RST group suggests that further study is needed to define the optimal use of this agent in combination with others to maximize effectiveness and minimize negative side effects.
- Published
- 2000
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.