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"Lopez, Martha"
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Release Behavior and Antibacterial Activity of Chitosan/Alginate Blends with Aloe vera and Silver Nanoparticles
2017
Aloe vera is a perennial plant employed for medical, pharmaceutical and cosmetic purposes that is rich in amino acids, enzymes, vitamins and polysaccharides, which are responsible for its therapeutic properties. Incorporating these properties into a biopolymer film obtained from alginate and chitosan allowed the development of a novel wound dressing with antibacterial capacity and healing effects to integrate the antibacterial capacity of silver nanoparticles with the healing and emollient properties of Aloe vera gel. Three alginate-chitosan matrices were obtained through blending methods using different proportions of alginate, chitosan, the Aloe vera (AV) gel and silver nanoparticles (AgNps), which were incorporated into the polymeric system through immersion methods. Physical, chemical and antibacterial characteristics were evaluated in each matrix. Interaction between alginate and chitosan was identified using the Fourier transform infrared spectroscopy technique (FTIR), porosity was studied using scanning electron microscopy (SEM), swelling degree was calculated by difference in weight, Aloe vera gel release capacity was estimated by applying a drug model (Peppas) and finally antibacterial capacity was evaluated against S. Aureus and P. aeruginosa. Results show that alginate-chitosan (A (1:3 Chit 1/Alg 1); B (1:3 Chit 1.5/Alg 1) and C (3:1 Chit 1/Alg 1/B12)) matrices with Aloe vera (AV) gel and silver nanoparticles (AgNps) described here displayed antibacterial properties and absorption and Aloe vera release capacity making it a potential wound dressing for minor injuries.
Journal Article
Postharvest application of partitioned plant extracts from Sinaloa, Mexico for controlling papaya pathogenic fungus Colletotrichum gloeosporioides
by
Bautista-Baños, Silvia
,
López-López, Martha E.
,
Ayón-Reyna, Lidia E.
in
Acetic acid
,
Anthracnose
,
Antifungal activity
2021
Anthracnose compromises papaya production and is caused by the fungus Colletotrichum gloeosporioides. New natural alternatives to synthetic fungicides are necessary to control anthracnose due to health and environmental concerns. In this regard, extracts of plants from Sinaloa, Mexico, have shown activity against molds and yeasts with medical and agricultural importance; however, their protective effect on papaya fruit infected with C. gloeosporioides is still unknown. This study aimed to assess the in vitro and in vivo antifungal activities of crude methanol extracts (ME) from nine plants from Sinaloa, Mexico, and their semi-purified fractions. In vitro assays showed that C. gloeosporioides was inhibited by 7 out the 16 extracts assessed; Psidium sartorianum (pulp), Echeveria kimnachii (leaf), and Vitex mollis (VM) (pulp) had the highest antifungal activity and the lowest toxicity against Artemia salina. When these extracts were fractionated, the activity increased. Hexane (HF-VM) and ethyl acetate (EAF-VM) fractions of V. mollis were the most effective fractions (MEF), with the lowest minimum inhibitory concentration (MIC) (20 and 30 mg/mL, respectively). The in vivo results showed that HF-VM at 40 mg/mL (HF40) was the best to delay the apparition and development of anthracnose symptoms. Coumarins, alkaloids and terpenes were detected on this fraction by tube assays or thin layer chromatography (TLC). Moreover, this treatment decreased water loss and did not affect any of the quality parameters assessed. Therefore, HF40 is a natural alternative to thiabendazole (TBZ) in the protection of papaya fruit against anthracnose.
Journal Article
Effects of Chronic Exposure to Low-Dose delta-9-Tetrahydrocannabinol in Adolescence and Adulthood on Serotonin/Norepinephrine Neurotransmission and Emotional Behavior
by
Canul, Martha-Lopez
,
De Gregorio, Danilo
,
Bambico, Francis Rodriguez
in
Adolescence
,
Adults
,
Child development
2020
Abstract
Background
Chronic exposure to D9-tetrahydrocannabinol (THC), the main pharmacological component of cannabis, during adolescence has been shown to be associated with an increased risk of depression and suicidality in humans. Little is known about the impact of the long-term effects of chronic exposure to low doses of THC in adolescent compared with adult rodents.
Methods
THC (1 mg/kg i.p., once per day) or vehicle was administered for 20 days in both adolescent (post-natal day 30–50) and young adult rats (post-natal day 50–70). After a long washout period (20 days), behavioral tests and electrophysiological recordings of serotonin and norepinephrine neurons were carried out.
Results
Adolescent THC exposure resulted in depressive behaviors: decreased latency to first immobility in the forced swim test and increased anhedonia in the sucrose preference test. Decreased entries in the open arms were observed in the elevated plus maze after adolescent and adult exposure, indicating an anxious phenotype. A significant reduction in dorsal raphe serotonergic neural activity without a change in locus coeruleus noradrenergic neural activity was found after adolescent and adult exposure.
Conclusions
Altogether, these findings suggest that chronic low-dose THC exposure during the critical developmental period of adolescence and during adulthood could result in increased vulnerability of the serotonin system accompanied by anxiety symptoms. However, depressive phenotypes occur only after adolescent exposure but not after adult exposure, underscoring the greater vulnerability of young ages to the mental effects of cannabis.
Journal Article
Nipbl and Mediator Cooperatively Regulate Gene Expression to Control Limb Development
by
Schilling, Thomas F.
,
Kikuchi, Yutaka
,
Lander, Arthur D.
in
Analysis
,
Animals
,
Animals, Genetically Modified
2014
Haploinsufficiency for Nipbl, a cohesin loading protein, causes Cornelia de Lange Syndrome (CdLS), the most common \"cohesinopathy\". It has been proposed that the effects of Nipbl-haploinsufficiency result from disruption of long-range communication between DNA elements. Here we use zebrafish and mouse models of CdLS to examine how transcriptional changes caused by Nipbl deficiency give rise to limb defects, a common condition in individuals with CdLS. In the zebrafish pectoral fin (forelimb), knockdown of Nipbl expression led to size reductions and patterning defects that were preceded by dysregulated expression of key early limb development genes, including fgfs, shha, hand2 and multiple hox genes. In limb buds of Nipbl-haploinsufficient mice, transcriptome analysis revealed many similar gene expression changes, as well as altered expression of additional classes of genes that play roles in limb development. In both species, the pattern of dysregulation of hox-gene expression depended on genomic location within the Hox clusters. In view of studies suggesting that Nipbl colocalizes with the mediator complex, which facilitates enhancer-promoter communication, we also examined zebrafish deficient for the Med12 Mediator subunit, and found they resembled Nipbl-deficient fish in both morphology and gene expression. Moreover, combined partial reduction of both Nipbl and Med12 had a strongly synergistic effect, consistent with both molecules acting in a common pathway. In addition, three-dimensional fluorescent in situ hybridization revealed that Nipbl and Med12 are required to bring regions containing long-range enhancers into close proximity with the zebrafish hoxda cluster. These data demonstrate a crucial role for Nipbl in limb development, and support the view that its actions on multiple gene pathways result from its influence, together with Mediator, on regulation of long-range chromosomal interactions.
Journal Article
Multiple Organ System Defects and Transcriptional Dysregulation in the Nipbl+/− Mouse, a Model of Cornelia de Lange Syndrome
by
Chua, Abigail
,
Lander, Arthur D.
,
Lopez-Burks, Martha E.
in
Animals
,
Animals, Newborn
,
Behavior
2009
Cornelia de Lange Syndrome (CdLS) is a multi-organ system birth defects disorder linked, in at least half of cases, to heterozygous mutations in the NIPBL gene. In animals and fungi, orthologs of NIPBL regulate cohesin, a complex of proteins that is essential for chromosome cohesion and is also implicated in DNA repair and transcriptional regulation. Mice heterozygous for a gene-trap mutation in Nipbl were produced and exhibited defects characteristic of CdLS, including small size, craniofacial anomalies, microbrachycephaly, heart defects, hearing abnormalities, delayed bone maturation, reduced body fat, behavioral disturbances, and high mortality (75-80%) during the first weeks of life. These phenotypes arose despite a decrease in Nipbl transcript levels of only approximately 30%, implying extreme sensitivity of development to small changes in Nipbl activity. Gene expression profiling demonstrated that Nipbl deficiency leads to modest but significant transcriptional dysregulation of many genes. Expression changes at the protocadherin beta (Pcdhb) locus, as well as at other loci, support the view that NIPBL influences long-range chromosomal regulatory interactions. In addition, evidence is presented that reduced expression of genes involved in adipogenic differentiation may underlie the low amounts of body fat observed both in Nipbl+/- mice and in individuals with CdLS.
Journal Article
A glass bead semi-hydroponic system for intact maize root exudate analysis and phenotyping
by
Wang, Peng
,
Alvarez, Sophie
,
Phares, Felicia
in
Analysis
,
Biological Techniques
,
Biomedical and Life Sciences
2022
Background
Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage.
Results
This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl
2
, and to measure root phenotype data using standard methods and the Digital imaging of root traits (DIRT) software. LC–MS/MS (Liquid Chromatography—Tandem Mass Spectrometry) and GC–MS (Gas Chromatography—Mass Spectrometry) targeted metabolomics platforms were used to detect and quantify metabolites in the root exudates. Phytohormones, some of which are reported in maize root exudates for the first time, the benzoxazinoid DIMBOA (2,4-Dihydroxy-7-methoxy-1,4-benzoxazin-3-one), amino acids, and sugars were detected and quantified. After validating the methodology using known concentrations of standards for the targeted compounds, we found that the choice of the exudate collection solution affected the exudation and analysis of a subset of analyzed metabolites. No differences between collection in water or CaCl
2
were found for phytohormones and sugars. In contrast, the amino acids were more concentrated when water was used as the exudate collection solution. The collection in CaCl
2
required a clean-up step before MS analysis which was found to interfere with the detection of a subset of the amino acids. Finally, using the phenotypic measurements and the metabolite data, significant differences between genotypes were found and correlations between metabolites and phenotypic traits were identified.
Conclusions
A new plant growth system combining glass beads supported hydroponics with semi-automated drip irrigation of sterile solutions was implemented to grow maize plants and collect root exudates without disturbing or damaging the roots. The validated targeted exudate metabolomics platform combined with root phenotyping provides a powerful tool to link plant root and exudate phenotypes to genotype and study the natural variation of plant populations.
Journal Article
Association analyses of host genetics, root-colonizing microbes, and plant phenotypes under different nitrogen conditions in maize
2022
The root-associated microbiome (rhizobiome) affects plant health, stress tolerance, and nutrient use efficiency. However, it remains unclear to what extent the composition of the rhizobiome is governed by intraspecific variation in host plant genetics in the field and the degree to which host plant selection can reshape the composition of the rhizobiome. Here, we quantify the rhizosphere microbial communities associated with a replicated diversity panel of 230 maize ( Zea mays L .) genotypes grown in agronomically relevant conditions under high N (+N) and low N (-N) treatments. We analyze the maize rhizobiome in terms of 150 abundant and consistently reproducible microbial groups and we show that the abundance of many root-associated microbes is explainable by natural genetic variation in the host plant, with a greater proportion of microbial variance attributable to plant genetic variation in -N conditions. Population genetic approaches identify signatures of purifying selection in the maize genome associated with the abundance of several groups of microbes in the maize rhizobiome. Genome-wide association study was conducted using the abundance of microbial groups as rhizobiome traits, and n=622 plant loci were identified that are linked to the abundance of n=104 microbial groups in the maize rhizosphere. In 62/104 cases, which is more than expected by chance, the abundance of these same microbial groups was correlated with variation in plant vigor indicators derived from high throughput phenotyping of the same field experiment. We provide comprehensive datasets about the three-way interaction of host genetics, microbe abundance, and plant performance under two N treatments to facilitate targeted experiments toward harnessing the full potential of root-associated microbial symbionts in maize production.
Journal Article
Stormwater Storage and Retention Within an Urban Prairie Wetland Complex
by
Jenkins, Jennifer
,
Miller, William M
,
Phillips, Colin B
in
Cities
,
Climate change
,
Climatic conditions
2025
Climate change is expected to increase the frequency and severity of flooding in the Great Lakes region. In many cities, flood‐control infrastructure is insufficient to protect against future climate conditions. Consequently, there is increasing focus on stormwater storage provided by urban greenspace, such as wetlands and prairies, but the ecohydrological behavior of these ecosystems is not well understood when they are embedded within cities. To improve understanding of hydrological connectivity between urban areas and natural greenspaces, we deployed a sensor network in Gensburg Markham Prairie (GMP), a large intact prairie‐wetland complex in south suburban Chicago. We used the resulting high‐frequency time‐series data to assess surface‐subsurface hydrologic dynamics between upland and low‐lying wetland areas, interactions between the prairie and surrounding environment, and stormwater storage provided by the prairie. Rapid infiltration within the prairie during and after storm events provides subsurface flow that stores considerable water, flattens storm hydrographs, and increases the wetland hydroperiod. Much of the stormwater input to GMP derives from the surrounding cityscape. Consequently, storage within the prairie‐wetland system reduces and slows stormwater discharge to downstream urban communities. For a typical 5‐year 24‐hr storm with 10.9 cm of rain, GMP stores 77,100 m3, 64% greater than the estimated direct rainfall volume onto the prairie, yielding 30,000 m3 of offsite stormwater storage. This improved understanding of ecohydrological dynamics in urban prairies and wetlands informs the design and implementation of green infrastructure to meet growing needs for stormwater management.
Journal Article
Conditional Creation and Rescue of Nipbl-Deficiency in Mice Reveals Multiple Determinants of Risk for Congenital Heart Defects
by
Santos, Rosaysela
,
Lander, Arthur D.
,
Lopez-Burks, Martha E.
in
Animals
,
Bioengineering
,
Biology
2016
Elucidating the causes of congenital heart defects is made difficult by the complex morphogenesis of the mammalian heart, which takes place early in development, involves contributions from multiple germ layers, and is controlled by many genes. Here, we use a conditional/invertible genetic strategy to identify the cell lineage(s) responsible for the development of heart defects in a Nipbl-deficient mouse model of Cornelia de Lange Syndrome, in which global yet subtle transcriptional dysregulation leads to development of atrial septal defects (ASDs) at high frequency. Using an approach that allows for recombinase-mediated creation or rescue of Nipbl deficiency in different lineages, we uncover complex interactions between the cardiac mesoderm, endoderm, and the rest of the embryo, whereby the risk conferred by genetic abnormality in any one lineage is modified, in a surprisingly non-additive way, by the status of others. We argue that these results are best understood in the context of a model in which the risk of heart defects is associated with the adequacy of early progenitor cell populations relative to the sizes of the structures they must eventually form.
Journal Article
Triclabendazole Treatment Failure for Fasciola hepatica Infection among Preschool and School-Age Children, Cusco, Peru
2021
We conducted a retrospective cohort study of children who had chronic fascioliasis in the highlands of Peru to determine triclabendazole treatment efficacy. Children passing Fasciola eggs in stool were offered directly observed triclabendazole treatment (>1 doses of 10 mg/kg). Parasitologic cure was evaluated by using microscopy of stool 1–4 months after each treatment. A total of 146 children who had chronic fascioliasis participated in the study; 53% were female, and the mean ± SD age was 10.4 ± 3.1 years. After the first treatment, 55% of the children achieved parasitologic cure. Cure rates decreased after the second (38%), third (30%), and fourth (23%) treatments; 17 children (11.6%) did not achieve cure after 4 treatments. Higher baseline egg counts and lower socioeconomic status were associated with triclabendazole treatment failure. Decreased triclabendazole efficacy in disease-endemic communities threatens control efforts. Further research on triclabendazole resistance and new drugs to overcome it are urgently needed.
Journal Article