Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 44
Filter
1.
Microbiol Spectr ; 11(3): e0433822, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37074181

ABSTRACT

Visceral leishmaniasis (VL) is caused by protozoan parasites of the Leishmania donovani complex and is one of the most prominent vector-borne infectious diseases with epidemic and mortality potential if not correctly diagnosed and treated. East African countries suffer from a very high incidence of VL, and although several diagnostic tests are available for VL, diagnosis continues to represent a big challenge in these countries due to the lack of sensitivity and specificity of current serological tools. Based on bioinformatic analysis, a new recombinant kinesin antigen from Leishmania infantum (rKLi8.3) was developed. The diagnostic performance of rKLi8.3 was evaluated by enzyme-linked immunosorbent assay (ELISA) and lateral flow test (LFT) on a panel of sera from Sudanese, Indian, and South American patients diagnosed with VL or other diseases, including tuberculosis, malaria, and trypanosomiasis. The diagnostic accuracy of rKLi8.3 was compared with rK39 and rKLO8 antigens. The VL-specific sensitivity of rK39, rKLO8, and rKLi8.3 ranged from 91.2% over 92.4% to 97.1% and specificity ranged from 93.6% over 97.6% to 99.2%, respectively. In India, all tests showed a comparable specificity of 90.9%, while the sensitivity ranged from 94.7% to 100% (rKLi8.3). In contrast to commercial serodiagnostic tests, rKLi8.3-based ELISA and LFT showed improved sensitivity and no cross-reactivity with other parasitic diseases. Thus, rKLi8.3-based ELISA and LFT offer improved VL serodiagnostic efficiency in East Africa and other areas of endemicity. IMPORTANCE Reliable and field suitable serodiagnosis of visceral leishmaniasis (VL) in East Africa has until now been a big challenge due to low sensitivity and cross-reactivity with other pathogens. To improve VL serodiagnosis, a new recombinant kinesin antigen from Leishmania infantum (rKLi8.3) was developed and tested with a panel of sera from Sudanese, Indian, and South American patients diagnosed with VL or other infectious diseases. Both prototype rKLi8.3-based enzyme-linked immunosorbent assay (ELISA) and lateral flow test (LFT) showed improved sensitivity and no cross-reactivity with other parasitic diseases. Thus, rKLi8.3-based ELISA and LFT offer substantially increased diagnostic efficiency for VL in East Africa and other areas of endemicity, compared to currently commercially available serodiagnostic tests.


Subject(s)
Leishmaniasis, Visceral , Humans , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/parasitology , Antigens, Protozoan , Protozoan Proteins , Kinesins , Serologic Tests , Enzyme-Linked Immunosorbent Assay
2.
Article in German | MEDLINE | ID: mdl-34861719

ABSTRACT

OBJECTIVE: This retrospective study describes the use of ventral mandibular trepanation for extraction of diseased mandibular incisors in guinea pigs and evaluates the clinical outcome. MATERIAL AND METHODS: In 40 guinea pigs with abnormal feed intake, at least one mandibular incisor was extracted via ventral mandibular trepanation. The diagnosis of primary mandibular incisor disease was based on the findings of the clinical general examination and intraoral and radiographic examination under general anesthesia. Following the procedure radiographs were taken and the patients were monitored and cared for as inpatients until discharge. Regular re-examinations were undertaken in order to assess and treat the surgical sites. RESULTS: A total of 42 altered mandibular incisors were extracted via ventral mandibular trepanation. Macrodonts (25/42) and periapical and alveolar changes (8/42) were the main reasons for extraction. Tooth residuals of unknown etiology (4/42) as well as such resulting from failed conventional extraction attempt using luxators (3/42) and traumatically loosened incisors (2/42) were also extracted. Tooth-associated jaw abscesses were found in 40 % of the guinea pigs. In addition, 40 % of the animals presented secondary elongation of the molars requiring occlusal equilibration. In all patients, it was possible to completely remove the altered incisors or residuals. On average, independent feed intake was observed 2 days after surgery and the animals were discharged. Complete healing of the surgical site was observed on average after 39 days (minimum 9 days, maximum 98 days). A total of 22 animals were evaluated 6 months following surgery and showed no further tooth-associated complaints. CONCLUSION AND CLINICAL RELEVANCE: Ventral mandibular trepanation allows diseased mandibular incisors in guinea pigs to be removed entirely within one surgery and thus represents a curative procedure. Unlike the conventional extraction with luxators, it does not bear the risk of tooth fractures resulting in tooth fragments remaining in the alveolus.


Subject(s)
Incisor , Trephining , Animals , Guinea Pigs , Incisor/diagnostic imaging , Incisor/surgery , Mandible/surgery , Retrospective Studies , Trephining/veterinary
3.
Adv Biochem Eng Biotechnol ; 174: 161-193, 2020.
Article in English | MEDLINE | ID: mdl-32157319

ABSTRACT

Since aptamers have been selected against a broad range of target structures of medical interest and nanoparticles are available with diverse properties, aptamer-modified nanoparticles can be used in various diagnostic and therapeutic applications. While the aptamer is responsible for specificity and affinity of the conjugate, the nanoparticles' function varies from signal generation in diagnostic approaches to drug loading in drug delivery systems. Within this chapter different medical applications of aptamer-modified nanoparticles will be summarized and underlying principles will be described.


Subject(s)
Aptamers, Nucleotide , Nanoparticles , Aptamers, Nucleotide/chemistry , Aptamers, Nucleotide/therapeutic use , Drug Delivery Systems , Humans , Nanoparticles/chemistry , Nanoparticles/therapeutic use
4.
Biosensors (Basel) ; 9(4)2019 Oct 14.
Article in English | MEDLINE | ID: mdl-31615077

ABSTRACT

Aptamers are single-stranded oligonucleotides which can be used as alternative recognition elements for protein detection, because aptamers bind their targets with a high affinity similar to antibodies. Due to the targetinduced conformational changes of aptamers, these oligonucleotides can be applied in various biosensing platforms. In this work, aptamers directed against the vascular endothelial growth factor (VEGF) were used as a model system. VEGF plays a key role in physiological angiogenesis and vasculogenesis. Furthermore, VEGF is involved in the development and growth of cancer and other diseases like agerelated macular degeneration, rheumatoid arthritis, diabetes mellitus, and neurodegenerative disorders. Detecting the protein biomarker VEGF is therefore of great importance for medical research and diagnostics. In this research, VEGFbinding aptamers were investigated for the systematic development of a targetinduced dissociation (TID) assay utilizing thermophoresis and microarrays. The established aptamer-microarray allowed for the detection of 0.1 nM of VEGF. Furthermore, the systematic development of the TID method using the VEGF model protein could help to develop further TID assays for the detection of various protein biomarkers.


Subject(s)
Aptamers, Nucleotide/chemistry , Biosensing Techniques , Vascular Endothelial Growth Factor A/chemistry , Humans , Oligonucleotide Array Sequence Analysis , Vascular Endothelial Growth Factor A/analysis
5.
Eng Life Sci ; 19(10): 658-665, 2019 Oct.
Article in English | MEDLINE | ID: mdl-32624959

ABSTRACT

Cancer is a worldwide increasing burden and its therapy is often challenging and causes severe side effects in healthy tissue. If drugs are loaded into nanoparticles, side effects can be reduced, and efficiency can be increased via the enhanced permeability and retention effect. This effect is based on the fact that nanoparticles with sizes from 10 to 200 nm can accumulate in tumor tissue due to their leaky vasculature. In this work, we produced polycaprolactone (PCL) in the sizes 1.8, 5.4, and 13.6 kDa and were able to produce spherical shaped nanoparticles with mean diameters of 64 ± 19 nm out of the PCL5.4 and 45 ± 8 nm out of the PCL13.6 reproducibly. By encapsulation of paclitaxel the diameter of that nanoparticles did not increase, and we were able to encapsulate 73 ± 7 fmol paclitaxel per 1000 particles in the PCL5.4-nanoparticles and 35 ± 8 fmol PTX per 1000 PCL13.6-nanoparticles. Furthermore, we coupled the aptamer S15 to preformed PCL5.4-nanoparticles resulting in particles with a hydrodynamic diameter of 153 nm. This offers the opportunity to use these nanoparticles for targeted drug delivery.

6.
Plant Physiol ; 169(4): 2665-83, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26424159

ABSTRACT

The development of abiotic stress-resistant cultivars is of premium importance for the agriculture of developing countries. Further progress in maize (Zea mays) performance under stresses is expected by combining marker-assisted breeding with metabolite markers. In order to dissect metabolic responses and to identify promising metabolite marker candidates, metabolite profiles of maize leaves were analyzed and compared with grain yield in field trials. Plants were grown under well-watered conditions (control) or exposed to drought, heat, and both stresses simultaneously. Trials were conducted in 2010 and 2011 using 10 tropical hybrids selected to exhibit diverse abiotic stress tolerance. Drought stress evoked the accumulation of many amino acids, including isoleucine, valine, threonine, and 4-aminobutanoate, which has been commonly reported in both field and greenhouse experiments in many plant species. Two photorespiratory amino acids, glycine and serine, and myoinositol also accumulated under drought. The combination of drought and heat evoked relatively few specific responses, and most of the metabolic changes were predictable from the sum of the responses to individual stresses. Statistical analysis revealed significant correlation between levels of glycine and myoinositol and grain yield under drought. Levels of myoinositol in control conditions were also related to grain yield under drought. Furthermore, multiple linear regression models very well explained the variation of grain yield via the combination of several metabolites. These results indicate the importance of photorespiration and raffinose family oligosaccharide metabolism in grain yield under drought and suggest single or multiple metabolites as potential metabolic markers for the breeding of abiotic stress-tolerant maize.


Subject(s)
Droughts , Hot Temperature , Metabolome , Metabolomics/methods , Plant Leaves/metabolism , Zea mays/metabolism , Amino Acids/metabolism , Analysis of Variance , Biomass , Edible Grain/metabolism , Genotype , Hybridization, Genetic , Oligosaccharides/metabolism , Plant Leaves/genetics , Principal Component Analysis , Seasons , Species Specificity , Stress, Physiological , Zea mays/classification , Zea mays/genetics
7.
Plant Cell Environ ; 38(8): 1591-612, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25630535

ABSTRACT

Most terrestrial plants benefit from the symbiosis with arbuscular mycorrhizal fungi (AMF) mainly under nutrient-limited conditions. Here the crop plant Zea mays was grown with and without AMF in a bi-compartmented system separating plant and phosphate (Pi) source by a hyphae-permeable membrane. Thus, Pi was preferentially taken up via the mycorrhizal Pi uptake pathway while other nutrients were ubiquitously available. To study systemic effects of mycorrhizal Pi uptake on leaf status, leaves of these plants that display an increased biomass in the presence of AMF were subjected to simultaneous ionomic, transcriptomic and metabolomic analyses. We observed robust changes of the leaf elemental composition, that is, increase of P, S and Zn and decrease of Mn, Co and Li concentration in mycorrhizal plants. Although changes in anthocyanin and lipid metabolism point to an improved P status, a global increase in C versus N metabolism highlights the redistribution of metabolic pools including carbohydrates and amino acids. Strikingly, an induction of systemic defence gene expression and concomitant accumulation of secondary metabolites such as the terpenoids alpha- and beta-amyrin suggest priming of mycorrhizal maize leaves as a mycorrhiza-specific response. This work emphasizes the importance of AM symbiosis for the physiological status of plant leaves and could lead to strategies for optimized breeding of crop species with high growth potential.


Subject(s)
Mycorrhizae/metabolism , Symbiosis , Zea mays/metabolism , Anthocyanins/metabolism , Biomass , Carbon/metabolism , Gene Expression Profiling , Gene Expression Regulation, Plant/drug effects , Lipid Metabolism/drug effects , Lipid Metabolism/genetics , Metabolome/drug effects , Metabolome/genetics , Multivariate Analysis , Mycorrhizae/drug effects , Nitrogen/metabolism , Phenotype , Phosphates/metabolism , Photosynthesis/drug effects , Photosynthesis/genetics , Plant Leaves/drug effects , Plant Leaves/genetics , Plant Leaves/metabolism , Principal Component Analysis , Symbiosis/drug effects , Symbiosis/genetics , Transcription, Genetic/drug effects , Zea mays/drug effects , Zea mays/genetics , Zea mays/growth & development
8.
Public Health Rep ; 128 Suppl 3: 48-53, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24179279

ABSTRACT

In Alameda County, California, significant health inequities by race/ethnicity, income, and place persist. Many of the county's low-income residents and residents of color live in communities that have faced historical and current disinvestment through public policies. This disinvestment affects community conditions such as access to economic opportunities, well-maintained and affordable housing, high-quality schools, healthy food, safe parks, and clean water and air. These community conditions greatly affect health. At the invitation of the Joint Center for Political and Economic Studies' national Place Matters initiative, Alameda County Supervisor Keith Carson's Office and the Alameda County Public Health Department launched Alameda County Place Matters, an initiative that addresses community conditions through local policy change. We describe the initiative's creation, activities, policy successes, and best practices.


Subject(s)
Health Status Disparities , Public Policy , Social Determinants of Health , California , Chronic Disease/prevention & control , Health Impact Assessment , Housing/standards , Humans , Needs Assessment , Practice Guidelines as Topic
9.
Plant Cell ; 25(6): 2253-64, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23792371

ABSTRACT

Regulation of transcriptional processes is a critical mechanism that enables efficient coordination of the synthesis of required proteins in response to environmental and cellular changes. Transcription factors require accurate activity regulation because they play a critical role as key mediators assuring specific expression of target genes. In this work, we show that cullin3-based E3 ligases have the potential to interact with a broad range of ethylene response factor (ERF)/APETALA2 (AP2) transcription factors, mediated by Math-BTB/POZ (for Meprin and TRAF [tumor necrosis factor receptor associated factor] homolog)-Broad complex, Tramtrack, Bric-a-brac/Pox virus and Zinc finger) proteins. The assembly with an E3 ligase causes degradation of their substrates via the 26S proteasome, as demonstrated for the wrinkled1 ERF/AP2 protein. Furthermore, loss of Math-BTB/POZ proteins widely affects plant development and causes altered fatty acid contents in mutant seeds. Overall, this work demonstrates a link between fatty acid metabolism and E3 ligase activities in plants and establishes CUL3-based E3 ligases as key regulators in transcriptional processes that involve ERF/AP2 family members.


Subject(s)
Arabidopsis Proteins/metabolism , Carrier Proteins/metabolism , Fatty Acids/metabolism , Ubiquitin-Protein Ligases/metabolism , Amino Acid Sequence , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Carrier Proteins/genetics , Chromatin Immunoprecipitation , Cullin Proteins , Cycloheximide/pharmacology , Gene Expression Regulation, Plant/drug effects , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Microscopy, Confocal , Molecular Sequence Data , Nucleotidyltransferases/genetics , Nucleotidyltransferases/metabolism , Plants, Genetically Modified , Proteasome Endopeptidase Complex/metabolism , Protein Binding , Reverse Transcriptase Polymerase Chain Reaction , Seeds/genetics , Seeds/metabolism , Sequence Homology, Amino Acid , Transcription Factors/genetics , Transcription Factors/metabolism , Two-Hybrid System Techniques , Ubiquitin-Protein Ligases/genetics
10.
Mol Plant ; 5(2): 401-17, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22180467

ABSTRACT

Adaptation to abiotic stresses like drought is an important acquirement of agriculturally relevant crops like maize. Development of enhanced drought tolerance in crops grown in climatic zones where drought is a very dominant stress factor therefore plays an essential role in plant breeding. Previous studies demonstrated that corn yield potential and enhanced stress tolerance are associated traits. In this study, we analyzed six different maize hybrids for their ability to deal with drought stress in a greenhouse experiment. We were able to combine data from morphophysiological parameters measured under well-watered conditions and under water restriction with metabolic data from different organs. These different organs possessed distinct metabolite compositions, with the leaf blade displaying the most considerable metabolome changes following water deficiency. Whilst we could show a general increase in metabolite levels under drought stress, including changes in amino acids, sugars, sugar alcohols, and intermediates of the TCA cycle, these changes were not differential between maize hybrids that had previously been designated based on field trial data as either drought-tolerant or susceptible. The fact that data described here resulted from a greenhouse experiment with rather different growth conditions compared to natural ones in the field may explain why tolerance groups could not be confirmed in this study. We were, however, able to highlight several metabolites that displayed conserved responses to drought as well as metabolites whose levels correlated well with certain physiological traits.


Subject(s)
Droughts , Hybridization, Genetic , Stress, Physiological , Zea mays/growth & development , Zea mays/metabolism , Analysis of Variance , Chlorophyll/metabolism , Genotype , Metabolome , Organ Specificity , Phenotype , Plant Leaves/physiology , Plant Stomata/physiology , Principal Component Analysis , Temperature , Zea mays/anatomy & histology , Zea mays/genetics
11.
BMC Plant Biol ; 12: 245, 2012 Dec 29.
Article in English | MEDLINE | ID: mdl-23272737

ABSTRACT

BACKGROUND: Maize is a major crop plant, grown for human and animal nutrition, as well as a renewable resource for bioenergy. When looking at the problems of limited fossil fuels, the growth of the world's population or the world's climate change, it is important to find ways to increase the yield and biomass of maize and to study how it reacts to specific abiotic and biotic stress situations. Within the OPTIMAS systems biology project maize plants were grown under a large set of controlled stress conditions, phenotypically characterised and plant material was harvested to analyse the effect of specific environmental conditions or developmental stages. Transcriptomic, metabolomic, ionomic and proteomic parameters were measured from the same plant material allowing the comparison of results across different omics domains. A data warehouse was developed to store experimental data as well as analysis results of the performed experiments. DESCRIPTION: The OPTIMAS Data Warehouse (OPTIMAS-DW) is a comprehensive data collection for maize and integrates data from different data domains such as transcriptomics, metabolomics, ionomics, proteomics and phenomics. Within the OPTIMAS project, a 44K oligo chip was designed and annotated to describe the functions of the selected unigenes. Several treatment- and plant growth stage experiments were performed and measured data were filled into data templates and imported into the data warehouse by a Java based import tool. A web interface allows users to browse through all stored experiment data in OPTIMAS-DW including all data domains. Furthermore, the user can filter the data to extract information of particular interest. All data can be exported into different file formats for further data analysis and visualisation. The data analysis integrates data from different data domains and enables the user to find answers to different systems biology questions. Finally, maize specific pathway information is provided. CONCLUSIONS: With OPTIMAS-DW a data warehouse for maize was established, which is able to handle different data domains, comprises several analysis results that will support researchers within their work and supports systems biological research in particular. The system is available at http://www.optimas-bioenergy.org/optimas_dw.


Subject(s)
Computational Biology , Database Management Systems , Zea mays , Databases, Factual , Internet , Metabolomics , Proteomics , User-Computer Interface , Zea mays/chemistry , Zea mays/genetics , Zea mays/metabolism
12.
Plant Physiol ; 157(1): 55-69, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21788362

ABSTRACT

The process of dark-induced senescence in plants is not fully understood, however, the functional involvement of an electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase (ETF/ETFQO), has been demonstrated. Recent studies have revealed that the enzymes isovaleryl-coenzyme A (CoA) dehydrogenase and 2-hydroxyglutarate dehydrogenase act as important electron donors to this complex. In addition both enzymes play a role in the breakdown of cellular carbon storage reserves with isovaleryl-CoA dehydrogenase being involved in degradation of the branched-chain amino acids, phytol, and lysine while 2-hydroxyglutarate dehydrogenase is exclusively involved in lysine degradation. Given that the chlorophyll breakdown intermediate phytanoyl-CoA accumulates dramatically both in knockout mutants of the ETF/ETFQO complex and of isovaleryl-CoA dehydrogenase following growth in extended dark periods we have investigated the direct importance of chlorophyll breakdown for the supply of carbon and electrons during this process. For this purpose we isolated three independent Arabidopsis (Arabidopsis thaliana) knockout mutants of phytanoyl-CoA 2-hydroxylase and grew them under the same extended darkness regime as previously used. Despite the fact that these mutants accumulated phytanoyl-CoA and also 2-hydroxyglutarate they exhibited no morphological changes in comparison to the other mutants previously characterized. These results are consistent with a single entry point of phytol breakdown into the ETF/ETFQO system and furthermore suggest that phytol is not primarily metabolized by this pathway. Furthermore analysis of isovaleryl-CoA dehydrogenase/2-hydroxyglutarate dehydrogenase double mutants generated here suggest that these two enzymes essentially account for the entire electron input via the ETF complex.


Subject(s)
Arabidopsis/enzymology , Coenzyme A/metabolism , Darkness , Electron-Transferring Flavoproteins/metabolism , Mutation , Oxidoreductases/metabolism , Phytanic Acid/analogs & derivatives , Ubiquitin/metabolism , Amino Acids/metabolism , Coenzyme A/genetics , Phytanic Acid/metabolism
13.
Plant J ; 66(3): 414-32, 2011 May.
Article in English | MEDLINE | ID: mdl-21241390

ABSTRACT

Vitamin B6 is an essential nutrient in the human diet derived primarily from plant sources. While it is well established as a cofactor for numerous metabolic enzymes, more recently, vitamin B6 has been implicated as a potent antioxidant. The de novo vitamin B6 biosynthesis pathway in plants has recently been unraveled and involves only two proteins, PDX1 and PDX2. To provide more insight into the effect of the compound on plant development and its role as an antioxidant, we have overexpressed the PDX proteins in Arabidopsis, generating lines with considerably higher levels of the vitamin in comparison with other recent attempts to achieve this goal. Interestingly, it was possible to increase the level of only one of the two catalytically active PDX1 proteins at the protein level, providing insight into the mechanism of vitamin B6 homeostasis in planta. Vitamin B6 enhanced lines have considerably larger vegetative and floral organs and although delayed in pre-reproductive development, do not have an altered overall morphology. The vitamin was observed to accumulate in seeds and the enhancement of its levels was correlated with an increase in their size and weight. This phenotype is predominantly a consequence of embryo enlargement as reflected by larger cells. Furthermore, plants that overaccumulate the vitamin have an increased tolerance to oxidative stress providing in vivo evidence for the antioxidant functionality of vitamin B6. In particular, the plants show an increased resistance to paraquat and photoinhibition, and they attenuate the cell death response observed in the conditional flu mutant.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Nitrogenous Group Transferases/metabolism , Oxidative Stress , Vitamin B 6/metabolism , Antioxidants/metabolism , Arabidopsis/genetics , Arabidopsis/growth & development , Arabidopsis Proteins/genetics , Carbon-Nitrogen Lyases , Gene Expression Regulation, Plant , Metabolome , Nitrogenous Group Transferases/genetics , Plants, Genetically Modified/genetics , Plants, Genetically Modified/growth & development , Plants, Genetically Modified/metabolism , Seeds/growth & development , Seeds/metabolism
14.
Circ Res ; 107(4): 549-57, 2010 Aug 20.
Article in English | MEDLINE | ID: mdl-20576933

ABSTRACT

RATIONALE: Elastin is a ubiquitous extracellular matrix protein that is highly organized in heart valves and arteries. Because elastic fiber abnormalities are a central feature of degenerative valve disease, we hypothesized that elastin-insufficient mice would manifest viable heart valve disease. OBJECTIVE: To analyze valve structure and function in elastin-insufficient mice (Eln(+/-)) at neonatal, juvenile, adult, and aged adult stages. METHODS AND RESULTS: At birth, histochemical analysis demonstrated normal extracellular matrix organization in contrast to the aorta. However, at juvenile and adult stages, thin elongated valves with extracellular matrix disorganization, including elastin fragment infiltration of the annulus, were observed. The valve phenotype worsened by the aged adult stage with overgrowth and proteoglycan replacement of the valve annulus. The progressive nature of elastin insufficiency was also shown by aortic mechanical testing that demonstrated incrementally abnormal tensile stiffness from juvenile to adult stages. Eln(+/-) mice demonstrated increased valve interstitial cell proliferation at the neonatal stage and varied valve interstitial cell activation at early and late stages. Gene expression profile analysis identified decreased transforming growth factor-beta-mediated fibrogenesis signaling in Eln(+/-) valve tissue. Juvenile Eln(+/-) mice demonstrated normal valve function, but progressive valve disease (predominantly aortic regurgitation) was identified in 17% of adult and 70% of aged adult Eln(+/-) mice by echocardiography. CONCLUSIONS: These results identify the Eln(+/-) mouse as a model of latent aortic valve disease and establish a role for elastin dysregulation in valve pathogenesis.


Subject(s)
Aortic Valve/abnormalities , Disease Models, Animal , Elastin/deficiency , Elastin/genetics , Heart Valve Diseases/genetics , Heart Valve Diseases/metabolism , Animals , Aortic Valve/metabolism , Aortic Valve/pathology , Disease Progression , Haploidy , Heart Valve Diseases/pathology , Mice , Mice, Inbred C57BL , Mice, Mutant Strains
15.
Plant Cell ; 22(5): 1549-63, 2010 May.
Article in English | MEDLINE | ID: mdl-20501910

ABSTRACT

The process of dark-induced senescence in plants is relatively poorly understood, but a functional electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase (ETF/ETFQO) complex, which supports respiration during carbon starvation, has recently been identified. Here, we studied the responses of Arabidopsis thaliana mutants deficient in the expression of isovaleryl-CoA dehydrogenase and 2-hydroxyglutarate dehydrogenase to extended darkness and other environmental stresses. Evaluations of the mutant phenotypes following carbon starvation induced by extended darkness identify similarities to those exhibited by mutants of the ETF/ETFQO complex. Metabolic profiling and isotope tracer experimentation revealed that isovaleryl-CoA dehydrogenase is involved in degradation of the branched-chain amino acids, phytol, and Lys, while 2-hydroxyglutarate dehydrogenase is involved exclusively in Lys degradation. These results suggest that isovaleryl-CoA dehydrogenase is the more critical for alternative respiration and that a series of enzymes, including 2-hydroxyglutarate dehydrogenase, plays a role in Lys degradation. Both physiological and metabolic phenotypes of the isovaleryl-CoA dehydrogenase and 2-hydroxyglutarate dehydrogenase mutants were not as severe as those observed for mutants of the ETF/ETFQO complex, indicating some functional redundancy of the enzymes within the process. Our results aid in the elucidation of the pathway of plant Lys catabolism and demonstrate that both isovaleryl-CoA dehydrogenase and 2-hydroxyglutarate dehydrogenase act as electron donors to the ubiquinol pool via an ETF/ETFQO-mediated route.


Subject(s)
Alcohol Oxidoreductases/metabolism , Arabidopsis/enzymology , Electrons , Isovaleryl-CoA Dehydrogenase/metabolism , Lysine/metabolism , Mitochondria/enzymology , Acyl Coenzyme A/metabolism , Carbohydrate Metabolism , DNA, Bacterial/genetics , Darkness , Electron Transport , Gas Chromatography-Mass Spectrometry , Isotope Labeling , Leucine/metabolism , Metabolome , Models, Biological , Mutagenesis, Insertional/genetics , Mutation/genetics , Phenotype , Phytol/metabolism , Plant Leaves/metabolism
17.
Plant Physiol ; 150(3): 1147-59, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19403724

ABSTRACT

The galactolipid digalactosyldiacylglycerol (DGD) is an abundant thylakoid lipid in chloroplasts. The introduction of the bacterial lipid glucosylgalactosyldiacylglycerol (GGD) from Chloroflexus aurantiacus into the DGD-deficient Arabidopsis (Arabidopsis thaliana) dgd1 mutant was previously shown to result in complementation of growth, but photosynthetic efficiency was only partially restored. Here, we demonstrate that GGD accumulation in the double mutant dgd1dgd2, which is totally devoid of DGD, also complements growth at normal and high-light conditions, but photosynthetic efficiency in the GGD-containing dgd1dgd2 line remains decreased. This is attributable to an increased susceptibility of photosystem II to photodamage, resulting in reduced photosystem II accumulation already at normal light intensities. The chloroplasts of dgd1 and dgd1dgd2 show alterations in thylakoid ultrastructure, a phenotype that is restored in the GGD-containing lines. These data suggest that the strong growth retardation of the DGD-deficient lines dgd1 and dgd1dgd2 can be primarily attributed to a decreased capacity for chloroplast membrane assembly and proliferation and, to a smaller extent, to photosynthetic deficiency. During phosphate limitation, GGD increases in plastidial and extraplastidial membranes of the transgenic lines to an extent similar to that of DGD in the wild type, indicating that synthesis and transport of the bacterial lipid (GGD) and of the authentic plant lipid (DGD) are subject to the same mechanisms of regulation.


Subject(s)
Arabidopsis/metabolism , Galactolipids/genetics , Homeostasis , Lipid Metabolism , Membrane Lipids/metabolism , Photosynthesis/physiology , Arabidopsis/physiology , Arabidopsis/ultrastructure , Arabidopsis Proteins/physiology , Arabidopsis Proteins/radiation effects , Biological Transport , Chloroflexus/metabolism , Chloroplasts/metabolism , Chloroplasts/ultrastructure , Diglycerides/metabolism , Galactolipids/metabolism , Galactolipids/physiology , Phenotype , Phosphates/metabolism , Photosystem II Protein Complex/physiology , Photosystem II Protein Complex/radiation effects , Plants, Genetically Modified/metabolism , Protein Stability , Thylakoids/metabolism , Thylakoids/ultrastructure
18.
J Pediatr ; 153(4): 565-9, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18534216

ABSTRACT

OBJECTIVES: Midwall shortening (mwSF) is thought to be a more accurate measure of myocardial performance in the presence of left ventricular hypertrophy (LVH). We examined mwSF in pediatric patients with varying degrees of chronic kidney disease (CKD). STUDY DESIGN: Fifty-seven children with CKD stages 2 to 4, 25 who were undergoing hemodialysis and 49 who were transplant recipients, were compared with 35 healthy control subjects. Left ventricular (LV) geometry and indices of LV function were assessed echocardiographically. RESULTS: There were no significant differences in LV contractility or endocardial shortening fraction between patients and control subjects. Yet, patients undergoing hemodialysis had significantly lower mwSF compared with control subjects (P < .01) and patients with stage 2 to 4 CKD (P < .01). Renal transplant patients had lower mwSF compared with control subjects (P < .01). The prevalence of abnormal mwSF (ie, <16) was significantly higher in patients undergoing hemodialysis (40%) compared with patients who were renal transplant recipeints (12%) and patients with CKD stages 2 to 4 (9%; P = .03). With stepwise regression, mwSF was demonstrated to be predicted by using relative wall thickness (P < .0001), dialysis group (P = .005), and endocardial shortening fraction (P = .001; model R(2) = 0.86). CONCLUSIONS: Children undergoing maintenance hemodialysis and children with concentric LVH have subclinical systolic dysfunction, which might be an indicator for the development of more severe cardiac disease.


Subject(s)
Heart/physiopathology , Hypertrophy, Left Ventricular/complications , Kidney Diseases/complications , Adolescent , Child , Chronic Disease , Echocardiography, Doppler , Female , Glomerular Filtration Rate , Humans , Hypertrophy, Left Ventricular/diagnostic imaging , Hypertrophy, Left Ventricular/physiopathology , Kidney Transplantation/physiology , Male , Renal Dialysis , Systole/physiology
19.
Pediatr Nephrol ; 23(8): 1297-302, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18458956

ABSTRACT

We sought to determine flow-mediated vasodilatation (FMD) of the brachial artery and to assess the relationship of FMD with multiple demographic, clinical and biochemical parameters and cardiac and vascular structure and function in children with chronic kidney disease (CKD) stages 2-4. Forty-three patients, aged 6-20 years, with CKD [mean glomerular filtration rate (GFR) 47 +/- 21 ml/min per 1.73 m2 body surface area, range 16-89 ml/min per 1.73 m2] and 34 healthy age-matched controls were included and studied cross-sectionally between 2001 and 2005. The peak FMD was similar in the CKD and control subjects (mean 6.3% vs 6.7%, P = 0.85). However, abnormally low FMD (< 1.1%) was found in ten (23%) children with CKD. Among children with CKD, those with low FMD were younger, shorter, lighter, and had lower body mass index (BMI) than children with normal FMD, but the difference reached statistical significance only for weight and BMI. Serum triglyceride levels were significantly lower in those with low FMD; otherwise, the two groups were similar with respect to multiple clinical and biochemical parameters. Cardiac and vascular structure was similar in children with normal and low FMD. In conclusion, children with CKD stage 2-4 appear to have increased prevalence of decreased FMD of the brachial artery. However, our study identified few significant factors associated with low FMD in children with CKD.


Subject(s)
Brachial Artery/physiology , Endothelium, Vascular/physiology , Regional Blood Flow/physiology , Renal Insufficiency, Chronic/physiopathology , Vasodilation/physiology , Adolescent , Body Mass Index , Child , Cohort Studies , Cross-Sectional Studies , Female , Glomerular Filtration Rate/physiology , Humans , Male , Renal Insufficiency, Chronic/epidemiology , Risk Factors , Triglycerides/blood
20.
J Am Coll Cardiol ; 51(14): 1342-8, 2008 Apr 08.
Article in English | MEDLINE | ID: mdl-18387434

ABSTRACT

OBJECTIVES: The purpose of this study was to evaluate changes in cardiac geometry, systolic and diastolic function before and after weight loss in morbidly obese adolescents. BACKGROUND: Cardiac abnormalities are present in morbidly obese adolescents; however, it is unclear if they are reversible with weight loss. METHODS: Data from 38 adolescents (13 to 19 years; 29 females, 9 males, 33 Caucasians, 5 African Americans) were evaluated before and after bariatric surgery. Left ventricular mass (LVM), left ventricular (LV) geometry, systolic and diastolic function were assessed by echocardiography. Mean follow up was 10 +/- 3 months. RESULTS: Weight and body mass index decreased post-operatively (mean weight loss 59 +/- 15 kg, pre-operative body mass index 60 +/- 9 kg/m(2) vs. follow-up 40 +/- 8 kg/m(2), p < 0.0001). Change in LVM index (54 +/- 13 g/m(2.7) to 42 +/- 10 g/m(2.7), p < 0.0001) correlated with weight loss (r = 0.41, p = 0.01). Prevalence of concentric left ventricular hypertrophy (LVH) improved from 28% at pre-operative to only 3% at follow up (p = 0.007), and normal LV geometry improved from 36% to 79% at follow up (p = 0.009). Diastolic function also improved (mitral E/Ea lateral 7.7 +/- 2.3 at pre-operative vs. 6.3 +/- 1.6 at post-operative, p = 0.003). In addition, rate-pressure product improved suggesting decreased cardiac workload (p < 0.001). CONCLUSIONS: Elevated LVM index, concentric LVH, altered diastolic function, and cardiac workload significantly improve following surgically induced weight loss in morbidly obese adolescents. Large weight loss due to bariatric surgery improves predictors of future cardiovascular morbidity in these young people.


Subject(s)
Bariatric Surgery , Heart Diseases/etiology , Heart Diseases/prevention & control , Heart/physiopathology , Obesity, Morbid/complications , Weight Loss , Adolescent , Adult , Body Mass Index , Diastole , Disease Progression , Female , Heart Diseases/physiopathology , Humans , Hypertrophy, Left Ventricular/etiology , Hypertrophy, Left Ventricular/physiopathology , Male , Obesity, Morbid/physiopathology , Obesity, Morbid/surgery , Prevalence , Systole
SELECTION OF CITATIONS
SEARCH DETAIL
...