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Mexican, Puerto Rican, and Central American Ancestry (MPRCA) individuals represent 82% of US Latinos. An intergenerational group of MPRCA women and allies met to discuss persistent underrepresentation of MPRCA women in STEM, identifying multi-level challenges and solutions. Implementation of these solutions is important and will benefit MPRCA women and the entire academic community.

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) is a novel coronavirus that infects many types of cells and causes cytokine storms, excessive inflammation, acute respiratory distress to induce failure of respiratory system and other critical organs. In this study, our results showed that trimethylamine-N-oxide (TMAO), a metabolite generated by gut microbiota, acts as a regulatory mediator to enhance the inerleukin-6 (IL-6) cytokine production and the infection of human endothelial progenitor cells (hEPCs) by SARS-CoV-2. Treatment of N-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) could effectively block the entry of SARS-CoV-2 in hEPCs. The anti-infection effects of N-3 PUFAs were associated with the inactivation of NF-κB signaling pathway, a decreased expression of the entry receptor angiotensin-converting enzyme 2 (ACE2) and downstream transmembrane serine protease 2 in hEPCs upon the stimulation of TMAO. Treatment of DHA and EPA further effectively inhibited TMAO-mediated expression of IL-6 protein, probably through an inactivation of MAPK/p38/JNK signaling cascades and a downregulation of microRNA (miR)-221 in hEPCs. In conclusion, N-3 PUFAs such as DHA and EPA could effectively act as preventive agents to block the infection of SARS-CoV-2 and IL-6 cytokine production in hEPCs upon the stimulation of TMAO.

Recombinant butyrylcholinesterase produced in a metabolically regulated transgenic rice cell culture (rrBChE) was purified to produce a highly pure (95%), active form of enzyme. The developed downstream process uses common manufacturing friendly operations including tangential flow filtration, anion-exchange chromatography, and affinity chromatography to obtain a process recovery of 42% active rrBChE. The purified rrBChE was then characterized to confirm its comparability to the native human form of the molecule (hBChE). The recombinant and native enzyme demonstrated comparable enzymatic behavior and had an identical amino acid sequence. However, rrBChE differs in that it contains plant-type complex N-glycans, including an α-1,3 linked core fucose, and a β-1,2 xylose, and lacking a terminal sialic acid. Despite this difference, rrBChE is demonstrated to be an effective stoichiometric bioscavenger for five different organophosphorous nerve agents in vitro. Together, the efficient downstream processing scheme and functionality of rrBChE confirm its promise as a cost-effective alternative to hBChE for prophylactic and therapeutic use.

Studies suggest that a low level of circulating human endothelial progenitor cells (EPCs) is a risk factor for ischemic injury and coronary artery disease (CAD). Consumption of S-allylcysteine (SAC) is known to prevent CAD. However, the protective effects of SAC on the ischemic injury are not yet clear. In this study, we examined whether SAC could improve blood flow recovery in ischemic tissues through EPC-mediated neovasculogenesis. The results demonstrate that SAC significantly enhances the neovasculogenesis of EPCs in vitro. The molecular mechanisms for SAC enhancement of neovasculogenesis include the activation of Akt/endothelial nitric oxide synthase signaling cascades. SAC increased the expression of c-kit, β-catenin, cyclin D1, and Cyclin-dependent kinase 4 (CDK4) proteins in EPCs. Daily intake of SAC at dosages of 0.2 and 2 mg/kg body weight significantly enhanced c-kit protein levels in vivo. We conclude that dietary consumption of SAC improves blood flow recovery and prevents ischemic injury by inducing neovasculogenesis in experimental models.

Studies suggest that a low level of circulating human endothelial progenitor cells (EPCs) is a risk factor for ischemic injury and coronary artery disease (CAD). Consumption of S-allylcysteine (SAC) is known to prevent CAD. However, the protective effects of SAC on the ischemic injury are not yet clear. In this study, we examined whether SAC could improve blood flow recovery in ischemic tissues through EPC-mediated neovasculogenesis. The results demonstrate that SAC significantly enhances the neovasculogenesis of EPCs in vitro. The molecular mechanisms for SAC enhancement of neovasculogenesis include the activation of Akt/endothelial nitric oxide synthase signaling cascades. SAC increased the expression of c-kit, β-catenin, cyclin D1, and Cyclin-dependent kinase 4 (CDK4) proteins in EPCs. Daily intake of SAC at dosages of 0.2 and 2 mg/kg body weight significantly enhanced c-kit protein levels in vivo. We conclude that dietary consumption of SAC improves blood flow recovery and prevents ischemic injury by inducing neovasculogenesis in experimental models.

Anthrax toxin receptor-mediated drug development for blocking anthrax toxin action has received much attention in recent decades. In this study, we produced a secreted anthrax decoy fusion protein comprised of a portion of the human capillary morphogenesis gene-2 (CMG2) protein fused via a linker to the fragment crystallizable (Fc) domain of human immunoglobulin G1 in Nicotiana benthamiana plants using a transient expression system. Using the Cauliflower Mosaic Virus (CaMV) 35S promoter and co-expression with the p19 gene silencing suppressor, we were able to achieve a high level of recombinant CMG2-Fc-Apo (rCMG2-Fc-Apo) protein accumulation. Production kinetics were observed up to eight days post-infiltration, and maximum production of 826 mg/kg fresh leaf weight was observed on day six. Protein A affinity chromatography purification of the rCMG2-Fc-Apo protein from whole leaf extract and apoplast wash fluid showed the homodimeric form under non-reducing gel electrophoresis and mass spectrometry analysis confirmed the molecular integrity of the secreted protein. The N-glycosylation pattern of purified rCMG2-Fc-Apo protein was analysed; the major portion of N-glycans consists of complex type structures in both protein samples. The most abundant (>50%) N-glycan structure was GlcNAc₂(Xyl)Man₃(Fuc)GlcNAc₂ in rCMG2-Fc-Apo recovered from whole leaf extract and apoplast wash fluid. High mannose N-glycan structures were not detected in the apoplast wash fluid preparation, which confirmed the protein secretion. Altogether, these findings demonstrate that high-level production of rCMG2-Fc-Apo can be achieved by transient production in Nicotiana benthamiana plants with apoplast targeting.

The processes that define mammalian physiology evolved millions of years ago in response to ancient signaling molecules, most of which were acquired by ingestion and digestion. In this way, evolution inextricably linked diet to all major physiological systems including the nervous system. The importance of diet in neurological development is well documented, although the mechanisms by which diet-derived signaling molecules (DSMs) affect cognition are poorly understood. Studies on the positive impact of nutritive and non-nutritive bioactive molecules on brain function are encouraging but lack the statistical power needed to demonstrate strong positive associations. Establishing associations between DSMs and cognitive functions like mood, memory and learning are made even more difficult by the lack of robust phenotypic markers that can be used to accurately and reproducibly measure the effects of DSMs. Lastly, it is now apparent that processes like neurogenesis and neuroplasticity are embedded within layers of interlocked signaling pathways and gene regulatory networks. Within these interdependent pathways and networks, the various transducers of DSMs are used combinatorially to produce those emergent adaptive gene expression responses needed for stimulus-induced neurogenesis and neuroplasticity. Taken together, it appears that cognition is encoded genomically and modified by epigenetics and epitranscriptomics to produce complex transcriptional programs that are exquisitely sensitive to signaling molecules from the environment. Models for how DSMs mediate the interplay between the environment and various neuronal processes are discussed in the context of the food-brain axis.

Anthrax toxin receptor-mediated drug development for blocking anthrax toxin action has received much attention in recent decades. In this study, we produced a secreted anthrax decoy fusion protein comprised of a portion of the human capillary morphogenesis gene-2 (CMG2) protein fused via a linker to the fragment crystallizable (Fc) domain of human immunoglobulin G1 in Nicotiana benthamiana plants using a transient expression system. Using the Cauliflower Mosaic Virus (CaMV) 35S promoter and co-expression with the p19 gene silencing suppressor, we were able to achieve a high level of recombinant CMG2-Fc-Apo (rCMG2-Fc-Apo) protein accumulation. Production kinetics were observed up to eight days post-infiltration, and maximum production of 826 mg/kg fresh leaf weight was observed on day six. Protein A affinity chromatography purification of the rCMG2-Fc-Apo protein from whole leaf extract and apoplast wash fluid showed the homodimeric form under non-reducing gel electrophoresis and mass spectrometry analysis confirmed the molecular integrity of the secreted protein. The N-glycosylation pattern of purified rCMG2-Fc-Apo protein was analysed; the major portion of N-glycans consists of complex type structures in both protein samples. The most abundant (>50%) N-glycan structure was GlcNAc₂(Xyl)Man₃(Fuc)GlcNAc₂ in rCMG2-Fc-Apo recovered from whole leaf extract and apoplast wash fluid. High mannose N-glycan structures were not detected in the apoplast wash fluid preparation, which confirmed the protein secretion. Altogether, these findings demonstrate that high-level production of rCMG2-Fc-Apo can be achieved by transient production in Nicotiana benthamiana plants with apoplast targeting.

The processes that define mammalian physiology evolved millions of years ago in response to ancient signaling molecules, most of which were acquired by ingestion and digestion. In this way, evolution inextricably linked diet to all major physiological systems including the nervous system. The importance of diet in neurological development is well documented, although the mechanisms by which diet-derived signaling molecules (DSMs) affect cognition are poorly understood. Studies on the positive impact of nutritive and non-nutritive bioactive molecules on brain function are encouraging but lack the statistical power needed to demonstrate strong positive associations. Establishing associations between DSMs and cognitive functions like mood, memory and learning are made even more difficult by the lack of robust phenotypic markers that can be used to accurately and reproducibly measure the effects of DSMs. Lastly, it is now apparent that processes like neurogenesis and neuroplasticity are embedded within layers of interlocked signaling pathways and gene regulatory networks. Within these interdependent pathways and networks, the various transducers of DSMs are used combinatorially to produce those emergent adaptive gene expression responses needed for stimulus-induced neurogenesis and neuroplasticity. Taken together, it appears that cognition is encoded genomically and modified by epigenetics and epitranscriptomics to produce complex transcriptional programs that are exquisitely sensitive to signaling molecules from the environment. Models for how DSMs mediate the interplay between the environment and various neuronal processes are discussed in the context of the food-brain axis.

An active and tetrameric form of recombinant butyrylcholinesterase (BChE), a large and complex human enzyme, was produced via semicontinuous operation in a transgenic rice cell suspension culture. After transformation of rice callus and screening of transformants, the cultures were scaled up from culture flask to a lab scale bioreactor. The bioreactor was operated through two phases each of growth and expression. The cells were able to produce BChE during both expression phases, with a maximum yield of 1.6 mg BChE/L of culture during the second expression phase. Cells successfully regrew during a 5-day growth phase. A combination of activity assays and Western blot analysis indicated production of an active and fully assembled tetramer of BChE.

An active and tetrameric form of recombinant butyrylcholinesterase (BChE), a large and complex human enzyme, was produced via semicontinuous operation in a transgenic rice cell suspension culture. After transformation of rice callus and screening of transformants, the cultures were scaled up from culture flask to a lab scale bioreactor. The bioreactor was operated through two phases each of growth and expression. The cells were able to produce BChE during both expression phases, with a maximum yield of 1.6 mg BChE/L of culture during the second expression phase. Cells successfully regrew during a 5-day growth phase. A combination of activity assays and Western blot analysis indicated production of an active and fully assembled tetramer of BChE.

To optimize the expression, extraction and purification of plant-derived tetrameric recombinant human butyrylcholinesterase (prBChE), we describe the development and use of plant viral amplicon-based gene expression system; Tobacco Mosaic Virus (TMV) RNA-based overexpression vector (TRBO) to express enzymatically active FLAG-tagged plant made recombinant butyrylcholinesterase (rBChE) in Nicotiana benthamiana leaves using transient agroinfiltration. Two gene expression cassettes were designed to express the recombinant protein in either the ER or to the apoplastic compartment. Leaf homogenization was used to isolate ER-retained recombinant butyrylcholinesterase (prBChE-ER) while apoplast-targeted rBChE was isolated by either leaf homogenization (prBChE) or vacuum-extraction of apoplastic wash fluid (prBChE-AWF). rBChE from apoplast wash fluid had a higher specific activity but lower enzyme yield than leaf homogenate. To optimize the isolation and purification of total recombinant protein from leaf homogenates, an acidic extraction buffer was used. The acidic extraction buffer yielded >95% enzymatically active tetrameric rBChE as verified by Coomassie stained and native gel electrophoresis. Furthermore, when compared to human butyrylcholinesterase, the prBChE was found to be similar in terms of tetramerization and enzyme kinetics. The N-linked glycan profile of purified prBChE-ER was found to be mostly high mannose structures while the N-linked glycans on prBChE-AWF were primarily complex. The glycan profile of the prBChE leaf homogenates showed a mixture of high mannose, complex and paucimannose type N-glycans. These findings demonstrate the ability of plants to produce rBChE that is enzymatically active and whose oligomeric state is comparable to mammalian butyrylcholinesterase. The process of plant made rBChE tetramerization and strategies for improving its pharmacokinetics properties are also discussed.

To optimize the expression, extraction and purification of plant-derived tetrameric recombinant human butyrylcholinesterase (prBChE), we describe the development and use of plant viral amplicon-based gene expression system; Tobacco Mosaic Virus (TMV) RNA-based overexpression vector (TRBO) to express enzymatically active FLAG-tagged plant made recombinant butyrylcholinesterase (rBChE) in Nicotiana benthamiana leaves using transient agroinfiltration. Two gene expression cassettes were designed to express the recombinant protein in either the ER or to the apoplastic compartment. Leaf homogenization was used to isolate ER-retained recombinant butyrylcholinesterase (prBChE-ER) while apoplast-targeted rBChE was isolated by either leaf homogenization (prBChE) or vacuum-extraction of apoplastic wash fluid (prBChE-AWF). rBChE from apoplast wash fluid had a higher specific activity but lower enzyme yield than leaf homogenate. To optimize the isolation and purification of total recombinant protein from leaf homogenates, an acidic extraction buffer was used. The acidic extraction buffer yielded >95% enzymatically active tetrameric rBChE as verified by Coomassie stained and native gel electrophoresis. Furthermore, when compared to human butyrylcholinesterase, the prBChE was found to be similar in terms of tetramerization and enzyme kinetics. The N-linked glycan profile of purified prBChE-ER was found to be mostly high mannose structures while the N-linked glycans on prBChE-AWF were primarily complex. The glycan profile of the prBChE leaf homogenates showed a mixture of high mannose, complex and paucimannose type N-glycans. These findings demonstrate the ability of plants to produce rBChE that is enzymatically active and whose oligomeric state is comparable to mammalian butyrylcholinesterase. The process of plant made rBChE tetramerization and strategies for improving its pharmacokinetics properties are also discussed.

Human endothelial progenitor cells (hEPCs) derived from bone marrow play a crucial in the prevention of ischemic injuries in the course of postnatal neovasculogenesis. Frequent fish oil (FO) consumption is reportedly associated with a significantly lower incidence of cardiovascular disease. However, the molecular mechanisms of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) are not well elucidated, and the beneficial effect of FO consumption on neovasculogenesis has not been demonstrated yet. In the current study, we investigated the effects of EPA/DHA and FO consumption on neovasculogenesis by using vascular tube formation assay, Western blotting, real-time polymerase chain reaction, immunohistochemical staining and Doppler imaging in both in vitro and in vivo models. The results demonstrate that EPA and DHA dose-dependently enhance the neovasculogenesis and cell migration of hEPCs in vitro. The mechanisms of action included up-regulation of the c-kit protein as well as the phosphorylation of the ERK1/2, Akt and endothelial nitric oxide synthase signaling molecules in hEPCs. Furthermore, EPA significantly suppressed the expression of microRNA 221 in vitro. In experimental animal models, FO consumption significantly induced the formation of new blood vessels (neovasculogenesis) and prevented ischemia. Taken together, it is suggested that FO consumption enhances neovasculogenesis mainly through the effects of EPA in hEPCs, thereby exerting a preventive effect against ischemic injury. © 2014 Elsevier Inc. All rights reserved.

Human endothelial progenitor cells (hEPCs) derived from bone marrow play a crucial in the prevention of ischemic injuries in the course of postnatal neovasculogenesis. Frequent fish oil (FO) consumption is reportedly associated with a significantly lower incidence of cardiovascular disease. However, the molecular mechanisms of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) are not well elucidated, and the beneficial effect of FO consumption on neovasculogenesis has not been demonstrated yet. In the current study, we investigated the effects of EPA/DHA and FO consumption on neovasculogenesis by using vascular tube formation assay, Western blotting, real-time polymerase chain reaction, immunohistochemical staining and Doppler imaging in both in vitro and in vivo models. The results demonstrate that EPA and DHA dose-dependently enhance the neovasculogenesis and cell migration of hEPCs in vitro. The mechanisms of action included up-regulation of the c-kit protein as well as the phosphorylation of the ERK1/2, Akt and endothelial nitric oxide synthase signaling molecules in hEPCs. Furthermore, EPA significantly suppressed the expression of microRNA 221 in vitro. In experimental animal models, FO consumption significantly induced the formation of new blood vessels (neovasculogenesis) and prevented ischemia. Taken together, it is suggested that FO consumption enhances neovasculogenesis mainly through the effects of EPA in hEPCs, thereby exerting a preventive effect against ischemic injury.

Human endothelial progenitor cells (hEPCs) derived from bone marrow play a crucial in the prevention of ischemic injuries in the course of postnatal neovasculogenesis. Frequent fish oil (FO) consumption is reportedly associated with a significantly lower incidence of cardiovascular disease. However, the molecular mechanisms of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) are not well elucidated, and the beneficial effect of FO consumption on neovasculogenesis has not been demonstrated yet. In the current study, we investigated the effects of EPA/DHA and FO consumption on neovasculogenesis by using vascular tube formation assay, Western blotting, real-time polymerase chain reaction, immunohistochemical staining and Doppler imaging in both in vitro and in vivo models. The results demonstrate that EPA and DHA dose-dependently enhance the neovasculogenesis and cell migration of hEPCs in vitro. The mechanisms of action included up-regulation of the c-kit protein as well as the phosphorylation of the ERK1/2, Akt and endothelial nitric oxide synthase signaling molecules in hEPCs. Furthermore, EPA significantly suppressed the expression of microRNA 221 in vitro. In experimental animal models, FO consumption significantly induced the formation of new blood vessels (neovasculogenesis) and prevented ischemia. Taken together, it is suggested that FO consumption enhances neovasculogenesis mainly through the effects of EPA in hEPCs, thereby exerting a preventive effect against ischemic injury.

BackgroundThe aberrant regulation of phosphatidylinositide 3-kinases (PI3-K)/Akt, AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (m-TOR) signaling pathways in cancer has prompted significant interest in the suppression of these pathways to treat cancer. Caffeic acid (CA) has been reported to possess important anti-inflammatory actions. However, the molecular mechanisms by which CA derivatives including caffeic acid phenethyl ester (CAPE) and caffeic acid phenylpropyl ester (CAPPE), exert inhibitory effects on the proliferation of human colorectal cancer (CRC) cells have yet to be elucidated.Methodology/principal findingsCAPE and CAPPE were evaluated for their ability to modulate these signaling pathways and suppress the proliferation of CRC cells both in vitro and in vivo. Anti-cancer effects of these CA derivatives were measured by using proliferation assays, cell cycle analysis, western blotting assay, reporter gene assay and immunohistochemical (IHC) staining assays both in vitro and in vivo. This study demonstrates that CAPE and CAPPE exhibit a dose-dependent inhibition of proliferation and survival of CRC cells through the induction of G0/G1 cell cycle arrest and augmentation of apoptotic pathways. Consumption of CAPE and CAPPE significantly inhibited the growth of colorectal tumors in a mouse xenograft model. The mechanisms of action included a modulation of PI3-K/Akt, AMPK and m-TOR signaling cascades both in vitro and in vivo. In conclusion, the results demonstrate novel anti-cancer mechanisms of CA derivatives against the growth of human CRC cells.ConclusionsCA derivatives are potent anti-cancer agents that augment AMPK activation and promote apoptosis in human CRC cells. The structure of CA derivatives can be used for the rational design of novel inhibitors that target human CRC cells.

BackgroundThe aberrant regulation of phosphatidylinositide 3-kinases (PI3-K)/Akt, AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (m-TOR) signaling pathways in cancer has prompted significant interest in the suppression of these pathways to treat cancer. Caffeic acid (CA) has been reported to possess important anti-inflammatory actions. However, the molecular mechanisms by which CA derivatives including caffeic acid phenethyl ester (CAPE) and caffeic acid phenylpropyl ester (CAPPE), exert inhibitory effects on the proliferation of human colorectal cancer (CRC) cells have yet to be elucidated.Methodology/principal findingsCAPE and CAPPE were evaluated for their ability to modulate these signaling pathways and suppress the proliferation of CRC cells both in vitro and in vivo. Anti-cancer effects of these CA derivatives were measured by using proliferation assays, cell cycle analysis, western blotting assay, reporter gene assay and immunohistochemical (IHC) staining assays both in vitro and in vivo. This study demonstrates that CAPE and CAPPE exhibit a dose-dependent inhibition of proliferation and survival of CRC cells through the induction of G0/G1 cell cycle arrest and augmentation of apoptotic pathways. Consumption of CAPE and CAPPE significantly inhibited the growth of colorectal tumors in a mouse xenograft model. The mechanisms of action included a modulation of PI3-K/Akt, AMPK and m-TOR signaling cascades both in vitro and in vivo. In conclusion, the results demonstrate novel anti-cancer mechanisms of CA derivatives against the growth of human CRC cells.ConclusionsCA derivatives are potent anti-cancer agents that augment AMPK activation and promote apoptosis in human CRC cells. The structure of CA derivatives can be used for the rational design of novel inhibitors that target human CRC cells.

BackgroundLife processes are determined by the organism's genetic profile and multiple environmental variables. However the interaction between these factors is inherently non-linear. Microarray data is one representation of the nonlinear interactions among genes and genes and environmental factors. Still most microarray studies use linear methods for the interpretation of nonlinear data. In this study, we apply Isomap, a nonlinear method of dimensionality reduction, to analyze three independent large Affymetrix high-density oligonucleotide microarray data sets.ResultsIsomap discovered low-dimensional structures embedded in the Affymetrix microarray data sets. These structures correspond to and help to interpret biological phenomena present in the data. This analysis provides examples of temporal, spatial, and functional processes revealed by the Isomap algorithm. In a spinal cord injury data set, Isomap discovers the three main modalities of the experiment--location and severity of the injury and the time elapsed after the injury. In a multiple tissue data set, Isomap discovers a low-dimensional structure that corresponds to anatomical locations of the source tissues. This model is capable of describing low- and high-resolution differences in the same model, such as kidney-vs.-brain and differences between the nuclei of the amygdala, respectively. In a high-throughput drug screening data set, Isomap discovers the monocytic and granulocytic differentiation of myeloid cells and maps several chemical compounds on the two-dimensional model.ConclusionVisualization of Isomap models provides useful tools for exploratory analysis of microarray data sets. In most instances, Isomap models explain more of the variance present in the microarray data than PCA or MDS. Finally, Isomap is a promising new algorithm for class discovery and class prediction in high-density oligonucleotide data sets.

BackgroundLife processes are determined by the organism's genetic profile and multiple environmental variables. However the interaction between these factors is inherently non-linear. Microarray data is one representation of the nonlinear interactions among genes and genes and environmental factors. Still most microarray studies use linear methods for the interpretation of nonlinear data. In this study, we apply Isomap, a nonlinear method of dimensionality reduction, to analyze three independent large Affymetrix high-density oligonucleotide microarray data sets.ResultsIsomap discovered low-dimensional structures embedded in the Affymetrix microarray data sets. These structures correspond to and help to interpret biological phenomena present in the data. This analysis provides examples of temporal, spatial, and functional processes revealed by the Isomap algorithm. In a spinal cord injury data set, Isomap discovers the three main modalities of the experiment--location and severity of the injury and the time elapsed after the injury. In a multiple tissue data set, Isomap discovers a low-dimensional structure that corresponds to anatomical locations of the source tissues. This model is capable of describing low- and high-resolution differences in the same model, such as kidney-vs.-brain and differences between the nuclei of the amygdala, respectively. In a high-throughput drug screening data set, Isomap discovers the monocytic and granulocytic differentiation of myeloid cells and maps several chemical compounds on the two-dimensional model.ConclusionVisualization of Isomap models provides useful tools for exploratory analysis of microarray data sets. In most instances, Isomap models explain more of the variance present in the microarray data than PCA or MDS. Finally, Isomap is a promising new algorithm for class discovery and class prediction in high-density oligonucleotide data sets.