This paper describes the use of data mining methods in e-learning system for providing feedback t... more This paper describes the use of data mining methods in e-learning system for providing feedback to courseware authors. The discovered information is presented in the form of prediction rules since these are highly comprehensible and they show important relationships among the presented data. The rules will be used to improve courseware, specially Adaptive Systems for Web-based Education (ASWE). We propose
Visual impairment due to glaucoma currently impacts 70 million people worldwide. While disease pr... more Visual impairment due to glaucoma currently impacts 70 million people worldwide. While disease progression can be slowed or stopped with effective lowering of intraocular pressure, current medical treatments are often inadequate. Fortunately, three new classes of therapeutics that target the diseased conventional outflow tissue responsible for ocular hypertension are in the final stages of human testing. The rho kinase inhibitors have proven particularly efficacious and additive to current therapies. Unfortunately, non-contact technology that monitors the health of outflow tissue and its response to conventional outflow therapy is not available clinically. Using optical coherence tomographic (OCT) imaging and novel segmentation software, we present the first demonstration of drug effects on conventional outflow tissues in living eyes. Topical netarsudil (formerly AR-13324), a rho kinase/ norepinephrine transporter inhibitor, affected both proximal (trabecular meshwork and Schlemm's Canal) and distal portions (intrascleral vessels) of the mouse conventional outflow tract. Hence, increased perfusion of outflow tissues was reliably resolved by OCT as widening of the trabecular meshwork and significant increases in cross-sectional area of Schlemm's canal following netarsudil treatment. These changes occurred in conjunction with increased outflow facility, increased speckle variance intensity of outflow vessels, increased tracer deposition in conventional outflow tissues and decreased intraocular pressure. This is the first report using live imaging to show real-time drug effects on conventional outflow tissues and specifically the mechanism of action of netarsudil in mouse eyes. Advancements here pave the way for development of a clinic-friendly OCT platform for monitoring glaucoma therapy.
Epitaxial layers of GaAs and GaAs:Si highly doped were grown on GaAs(100) at a substrate temperat... more Epitaxial layers of GaAs and GaAs:Si highly doped were grown on GaAs(100) at a substrate temperature of 600 Ā°C by molecular beam epitaxy. The layers were characterized by Auger electron spectroscopy, double crystal X ray diffractometry and low temperature photoluminescence (PL). It is shown that the main impurity present in the layers is carbon. The PL spectra of the GaAs:Si
c-Crystallin is a novel nicotinamide adenine dinucleotide phosphate : quinone reductase, present ... more c-Crystallin is a novel nicotinamide adenine dinucleotide phosphate : quinone reductase, present at enzymatic levels in various tissues of different species, which is highly expressed in the lens of some hystricomorph rodents and camelids. We report here the complementary DNA (cDNA) cloning of c-crystallin from liver libraries in guinea pig ( Cavia porcellus), where I;-crystallin is highly expressed in the
HortScience: a publication of the American Society for Horticultural Science
The most important worldwide problem in citrus production is the bacterial disease Huanglongbing ... more The most important worldwide problem in citrus production is the bacterial disease Huanglongbing (HLB; citrus greening) caused by a phloem-limited bacterium Candidatus Liberibacter asiaticus. The earliest visible symptoms of HLB on leaves are vein yellowing and an asymmetrical chlorosis referred to as āāblotchy mottle,āā thought to be the result of starch accumulation. We tested the hypothesis that such visible symptoms are not unique to HLB by stem girdling 2-year-old seedlings of two citrus rootstocks with and without drought stress in the greenhouse. After 31 days, girdling had little effect on shoot growth but girdling increased the relative growth rate of shoots in drought-stressed trees. Starch content in woody roots of non-girdled trees was three to 19 times higher than in girdled trees. In non-girdled trees, drought stress induced some starch accumulation in roots, but there were no effects of drought stress on root starch or sucrose in girdled trees. Girdling induced a 4-fo...
To study the gene expression profile of the human trabecular meshwork (HTM). A polymerase chain r... more To study the gene expression profile of the human trabecular meshwork (HTM). A polymerase chain reaction (PCR)-amplified cDNA library was constructed using RNA from the TM of a 67-year-old normal, perfused human eye. A total of 1060 clones were randomly selected for sequencing of one end. These sequences were searched against nonredundant GenBank and dbEST databases for similarity comparison by using a FASTA file and the BLASTcl3 program. Relative expression patterns of those clones that matched other expressed sequence tags (ESTs) were determined using the National Center for Biotechnology Information (NCBI) Unique Human Gene Sequence Collection (UniGene) database. Of the 1060 clones analyzed, 519 (48.9%) had sequences identical with known genes, 125 (11.8%) matched ESTs, and 189 (17.8%) did not match any database sequences. Of the remaining clones, 31 (3%) corresponded to mitochondrial transcripts and 196 (18.5%) to repetitive and noninformative sequences. It is notable that some ...
To identify genes upregulated in perfused, intact human trabecular meshwork (TM) in response to e... more To identify genes upregulated in perfused, intact human trabecular meshwork (TM) in response to elevated intraocular pressure (IOP). Two pairs of anterior segments of normal human eyes from postmortem donors were placed in culture and perfused 24 hours at constant flow (3 microl/min). After reaching baseline, the flow of one eye from each pair was raised to obtain an incremental pressure (deltaP) of 50 mm Hg for 6 hours. The anterior segments were then quickly frozen in liquid nitrogen, and their TMs were dissected for RNA extraction. SMART cDNA libraries were generated from control and high-pressure human TM RNAs and hybridized to sets of identical high-density cDNA gene arrays. These arrays contained 18,376 human expressed sequence tags (ESTs), corresponding to both characterized and unknown genes. Differentially expressed genes were identified by different-intensity hybridization signals and confirmed by semi-quantitative polymerase chain reaction. Eleven genes were found to be c...
Additional index words. sucrose uptake, sink strength, storage tissue Abstract. By combining the ... more Additional index words. sucrose uptake, sink strength, storage tissue Abstract. By combining the principles of density gradient separation and two phase par- titioning, we devised a system to obtain highly pure plasmalemma and tonoplast vesicles from citrus (Citrus limettioides Tan.) juice cells. Both tonoplast and plasmalemma fractions were virtually free from golgi, endoplasmic reticulum and mitochondria contamination. Plasmalemma and tonoplast
To contrast genome-wide gene expression profiles of cultured human trabecular meshwork (HTM) cell... more To contrast genome-wide gene expression profiles of cultured human trabecular meshwork (HTM) cells to that of control and primary open angle glaucoma (POAG) HTM tissues. Cultured HTM cells, HTM tissue dissected from control donors, and HTM tissue from POAG donors receiving medication for glaucoma were fixed in RNA latertrade mark. Total RNA extracted from these samples was linearly amplified with the Ovation Biotin RNA Amplification and Labeling System and individually hybridized to Affymetrix Human Genome U133 Plus 2.0 high density microarrays. Data analysis was performed using GeneSpring Software 7.0. Selected genes showing significant differential expression were validated by quantitative real-time PCR in nonamplified RNA. Cultured HTM cells retained the expression of some genes characteristic of HTM tissue, including chitinase 3-like 1 and matrix Gla protein, but demonstrated downregulation of physiologically important genes such as myocilin. POAG HTM tissue showed relatively sm...
To identify if recently described LOXL1 (lysyl oxidase-like 1) polymorphisms are associated with ... more To identify if recently described LOXL1 (lysyl oxidase-like 1) polymorphisms are associated with pseudoexfoliation glaucoma (XFG) in a United States (U.S.) Caucasian patient population. Individuals with XFG were identified using standard clinical examination techniques. TaqMan allelic discrimination assays were used to genotype 13 single nucleotide polymorphisms (SNPs) that tag LOXL1 in Caucasian individuals. The coding region of exon 1 that includes the previously associated SNP, rs1048661, was sequenced. Allele and genotype frequencies were compared between cases and unrelated controls. Fifty affected individuals and 235 control individuals were recruited into this study. We replicated the previously reported association of three SNPs (rs1048661, rs2165241, and rs3825942) in our independent XFG population (single SNP p-values were 0.001-0.02). The risk alleles at these three and several other intragenic SNPs are part of an extended XFG-associated LOXL1 haplotype with a frequency o...
To explore lens crystallin characteristics and morphology of rabbit regenerated lenses in compari... more To explore lens crystallin characteristics and morphology of rabbit regenerated lenses in comparison with wild type natural lenses by means of proteomic analysis and histological assay. The lens regeneration model of the New Zealand rabbit was established, and lens regeneration was observed by slit lamp examination and photography. A histological assay was evaluated under light microscopy and transmission electron microscopy (TEM). Protein samples of regenerated lenses were collected from experimental rabbit eyes 2, 4, and 16 weeks after surgery. Two-dimensional gel electrophoresis (2-DE) was performed. Image analyses was done using the ImageMaster 2D Elite 3.01 software package. The protein spots were trypsinized and identified by matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry. Lens regeneration began in the periphery of the capsule bag about one to two weeks after the surgery and proceeded to regenerate toward the center. The regenerated lens appeared...
To investigate the changes in gene expression induced by cyclic mechanical stress (CMS) in trabec... more To investigate the changes in gene expression induced by cyclic mechanical stress (CMS) in trabecular meshwork (TM) cells. Human TM cultures from three donors were plated on type I collagen-coated flexible silicone bottom plates and subjected to 15% stretching, one cycle per second for 6 h. Non-stressed parallel control cultures were incubated under the same conditions in the absence of CMS. Total RNA from each culture was amplified (1 round of amplification) and hybridized to Operon Human Oligo Arrays version 3.0 (35 K probes). Differences in gene expression induced by CMS were analyzed using Genespring 7.2. quantitative polymerase chain reaction (Q-PCR) was used to confirm changes in the expressions of 12 selected genes. The effects of chemical inhibitors for p38, ERK (extracellular signal-regulated kinase), JNK (Jun N-terminal kinase), PKA (protein kinase A), PI3K (phosphoinositide 3-kinase), and P2 (purinergic 2) receptors on the induction of MMP3 (matrix metalloproteinase 3), H...
This paper describes the use of data mining methods in e-learning system for providing feedback t... more This paper describes the use of data mining methods in e-learning system for providing feedback to courseware authors. The discovered information is presented in the form of prediction rules since these are highly comprehensible and they show important relationships among the presented data. The rules will be used to improve courseware, specially Adaptive Systems for Web-based Education (ASWE). We propose
Visual impairment due to glaucoma currently impacts 70 million people worldwide. While disease pr... more Visual impairment due to glaucoma currently impacts 70 million people worldwide. While disease progression can be slowed or stopped with effective lowering of intraocular pressure, current medical treatments are often inadequate. Fortunately, three new classes of therapeutics that target the diseased conventional outflow tissue responsible for ocular hypertension are in the final stages of human testing. The rho kinase inhibitors have proven particularly efficacious and additive to current therapies. Unfortunately, non-contact technology that monitors the health of outflow tissue and its response to conventional outflow therapy is not available clinically. Using optical coherence tomographic (OCT) imaging and novel segmentation software, we present the first demonstration of drug effects on conventional outflow tissues in living eyes. Topical netarsudil (formerly AR-13324), a rho kinase/ norepinephrine transporter inhibitor, affected both proximal (trabecular meshwork and Schlemm's Canal) and distal portions (intrascleral vessels) of the mouse conventional outflow tract. Hence, increased perfusion of outflow tissues was reliably resolved by OCT as widening of the trabecular meshwork and significant increases in cross-sectional area of Schlemm's canal following netarsudil treatment. These changes occurred in conjunction with increased outflow facility, increased speckle variance intensity of outflow vessels, increased tracer deposition in conventional outflow tissues and decreased intraocular pressure. This is the first report using live imaging to show real-time drug effects on conventional outflow tissues and specifically the mechanism of action of netarsudil in mouse eyes. Advancements here pave the way for development of a clinic-friendly OCT platform for monitoring glaucoma therapy.
Epitaxial layers of GaAs and GaAs:Si highly doped were grown on GaAs(100) at a substrate temperat... more Epitaxial layers of GaAs and GaAs:Si highly doped were grown on GaAs(100) at a substrate temperature of 600 Ā°C by molecular beam epitaxy. The layers were characterized by Auger electron spectroscopy, double crystal X ray diffractometry and low temperature photoluminescence (PL). It is shown that the main impurity present in the layers is carbon. The PL spectra of the GaAs:Si
c-Crystallin is a novel nicotinamide adenine dinucleotide phosphate : quinone reductase, present ... more c-Crystallin is a novel nicotinamide adenine dinucleotide phosphate : quinone reductase, present at enzymatic levels in various tissues of different species, which is highly expressed in the lens of some hystricomorph rodents and camelids. We report here the complementary DNA (cDNA) cloning of c-crystallin from liver libraries in guinea pig ( Cavia porcellus), where I;-crystallin is highly expressed in the
HortScience: a publication of the American Society for Horticultural Science
The most important worldwide problem in citrus production is the bacterial disease Huanglongbing ... more The most important worldwide problem in citrus production is the bacterial disease Huanglongbing (HLB; citrus greening) caused by a phloem-limited bacterium Candidatus Liberibacter asiaticus. The earliest visible symptoms of HLB on leaves are vein yellowing and an asymmetrical chlorosis referred to as āāblotchy mottle,āā thought to be the result of starch accumulation. We tested the hypothesis that such visible symptoms are not unique to HLB by stem girdling 2-year-old seedlings of two citrus rootstocks with and without drought stress in the greenhouse. After 31 days, girdling had little effect on shoot growth but girdling increased the relative growth rate of shoots in drought-stressed trees. Starch content in woody roots of non-girdled trees was three to 19 times higher than in girdled trees. In non-girdled trees, drought stress induced some starch accumulation in roots, but there were no effects of drought stress on root starch or sucrose in girdled trees. Girdling induced a 4-fo...
To study the gene expression profile of the human trabecular meshwork (HTM). A polymerase chain r... more To study the gene expression profile of the human trabecular meshwork (HTM). A polymerase chain reaction (PCR)-amplified cDNA library was constructed using RNA from the TM of a 67-year-old normal, perfused human eye. A total of 1060 clones were randomly selected for sequencing of one end. These sequences were searched against nonredundant GenBank and dbEST databases for similarity comparison by using a FASTA file and the BLASTcl3 program. Relative expression patterns of those clones that matched other expressed sequence tags (ESTs) were determined using the National Center for Biotechnology Information (NCBI) Unique Human Gene Sequence Collection (UniGene) database. Of the 1060 clones analyzed, 519 (48.9%) had sequences identical with known genes, 125 (11.8%) matched ESTs, and 189 (17.8%) did not match any database sequences. Of the remaining clones, 31 (3%) corresponded to mitochondrial transcripts and 196 (18.5%) to repetitive and noninformative sequences. It is notable that some ...
To identify genes upregulated in perfused, intact human trabecular meshwork (TM) in response to e... more To identify genes upregulated in perfused, intact human trabecular meshwork (TM) in response to elevated intraocular pressure (IOP). Two pairs of anterior segments of normal human eyes from postmortem donors were placed in culture and perfused 24 hours at constant flow (3 microl/min). After reaching baseline, the flow of one eye from each pair was raised to obtain an incremental pressure (deltaP) of 50 mm Hg for 6 hours. The anterior segments were then quickly frozen in liquid nitrogen, and their TMs were dissected for RNA extraction. SMART cDNA libraries were generated from control and high-pressure human TM RNAs and hybridized to sets of identical high-density cDNA gene arrays. These arrays contained 18,376 human expressed sequence tags (ESTs), corresponding to both characterized and unknown genes. Differentially expressed genes were identified by different-intensity hybridization signals and confirmed by semi-quantitative polymerase chain reaction. Eleven genes were found to be c...
Additional index words. sucrose uptake, sink strength, storage tissue Abstract. By combining the ... more Additional index words. sucrose uptake, sink strength, storage tissue Abstract. By combining the principles of density gradient separation and two phase par- titioning, we devised a system to obtain highly pure plasmalemma and tonoplast vesicles from citrus (Citrus limettioides Tan.) juice cells. Both tonoplast and plasmalemma fractions were virtually free from golgi, endoplasmic reticulum and mitochondria contamination. Plasmalemma and tonoplast
To contrast genome-wide gene expression profiles of cultured human trabecular meshwork (HTM) cell... more To contrast genome-wide gene expression profiles of cultured human trabecular meshwork (HTM) cells to that of control and primary open angle glaucoma (POAG) HTM tissues. Cultured HTM cells, HTM tissue dissected from control donors, and HTM tissue from POAG donors receiving medication for glaucoma were fixed in RNA latertrade mark. Total RNA extracted from these samples was linearly amplified with the Ovation Biotin RNA Amplification and Labeling System and individually hybridized to Affymetrix Human Genome U133 Plus 2.0 high density microarrays. Data analysis was performed using GeneSpring Software 7.0. Selected genes showing significant differential expression were validated by quantitative real-time PCR in nonamplified RNA. Cultured HTM cells retained the expression of some genes characteristic of HTM tissue, including chitinase 3-like 1 and matrix Gla protein, but demonstrated downregulation of physiologically important genes such as myocilin. POAG HTM tissue showed relatively sm...
To identify if recently described LOXL1 (lysyl oxidase-like 1) polymorphisms are associated with ... more To identify if recently described LOXL1 (lysyl oxidase-like 1) polymorphisms are associated with pseudoexfoliation glaucoma (XFG) in a United States (U.S.) Caucasian patient population. Individuals with XFG were identified using standard clinical examination techniques. TaqMan allelic discrimination assays were used to genotype 13 single nucleotide polymorphisms (SNPs) that tag LOXL1 in Caucasian individuals. The coding region of exon 1 that includes the previously associated SNP, rs1048661, was sequenced. Allele and genotype frequencies were compared between cases and unrelated controls. Fifty affected individuals and 235 control individuals were recruited into this study. We replicated the previously reported association of three SNPs (rs1048661, rs2165241, and rs3825942) in our independent XFG population (single SNP p-values were 0.001-0.02). The risk alleles at these three and several other intragenic SNPs are part of an extended XFG-associated LOXL1 haplotype with a frequency o...
To explore lens crystallin characteristics and morphology of rabbit regenerated lenses in compari... more To explore lens crystallin characteristics and morphology of rabbit regenerated lenses in comparison with wild type natural lenses by means of proteomic analysis and histological assay. The lens regeneration model of the New Zealand rabbit was established, and lens regeneration was observed by slit lamp examination and photography. A histological assay was evaluated under light microscopy and transmission electron microscopy (TEM). Protein samples of regenerated lenses were collected from experimental rabbit eyes 2, 4, and 16 weeks after surgery. Two-dimensional gel electrophoresis (2-DE) was performed. Image analyses was done using the ImageMaster 2D Elite 3.01 software package. The protein spots were trypsinized and identified by matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry. Lens regeneration began in the periphery of the capsule bag about one to two weeks after the surgery and proceeded to regenerate toward the center. The regenerated lens appeared...
To investigate the changes in gene expression induced by cyclic mechanical stress (CMS) in trabec... more To investigate the changes in gene expression induced by cyclic mechanical stress (CMS) in trabecular meshwork (TM) cells. Human TM cultures from three donors were plated on type I collagen-coated flexible silicone bottom plates and subjected to 15% stretching, one cycle per second for 6 h. Non-stressed parallel control cultures were incubated under the same conditions in the absence of CMS. Total RNA from each culture was amplified (1 round of amplification) and hybridized to Operon Human Oligo Arrays version 3.0 (35 K probes). Differences in gene expression induced by CMS were analyzed using Genespring 7.2. quantitative polymerase chain reaction (Q-PCR) was used to confirm changes in the expressions of 12 selected genes. The effects of chemical inhibitors for p38, ERK (extracellular signal-regulated kinase), JNK (Jun N-terminal kinase), PKA (protein kinase A), PI3K (phosphoinositide 3-kinase), and P2 (purinergic 2) receptors on the induction of MMP3 (matrix metalloproteinase 3), H...
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Papers by Pedro Gonzalez