Publications by authors named "Smith Donald"

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  • Oral antibiotic use in older adults can disrupt gut microbiota, leading to health issues like infections and chronic diseases.
  • A study involving mice showed that those on a high glycemic diet with antibiotics had significantly lower survival rates due to severe gut damage, unlike those on a low glycemic diet.
  • The low glycemic diet helped maintain a healthier gut microbiome and preserved important bacterial functions, suggesting it could be a helpful strategy to prevent gut issues caused by antibiotics.
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  • The article outlines recent updates to virus taxonomy approved by the International Committee on Taxonomy of Viruses (ICTV) in April 2024.
  • The ICTV invited members to vote on 203 taxonomic proposals, resulting in significant additions across various levels, including one new phylum and 3,547 new species.
  • The total number of established virus species now stands at 14,690, following the ratification of proposals for species name formatting to the binomial system.
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  • - Neurodegenerative retinal diseases like glaucoma and diabetic retinopathy involve the gradual death of retinal ganglion cells (RGCs), driven by mitochondrial dysfunction, oxidative stress, and decreased energy production.
  • - Familial dysautonomia (FD) also leads to RGC degeneration, revealing disruptions in mitochondrial structures and energy metabolism that may impact overall visual health, with specific changes in the serum and stool metabolomes indicating systemic deficiencies.
  • - The study investigated alterations in retinal metabolites and focused on dopaminergic amacrine cells, which influence RGC activity, using advanced techniques like NMR spectroscopy and mass spectrometry to link these changes to the progressive loss of RGCs in an FD mouse model.
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Background: Motor function is critical for children's health, yet remains an understudied neurodevelopmental domain. Exposure to metals has been linked with motor function, but no study has examined the joint effects of metal mixtures.

Methods: We evaluated cross-sectional associations between a metal mixture and motor function among 569 adolescents (10-14 years old) living near the ferroalloy industry.

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Endophytic microorganisms represent promising solutions to environmental challenges inherent in conventional agricultural practices. This study concentrates on the identification of endophytic bacteria isolated from the root, stem, and leaf tissues of four plant species. Sixty-one strains were isolated and sequenced by 16S rDNA.

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Background: Manganese (Mn) is an essential nutrient and neurotoxicant, and the neurodevelopmental effects of Mn may depend on exposure timing. Less research has quantitatively compared the impact of Mn exposure on neurodevelopment across exposure periods.

Methods: We used data from 125 Italian adolescents (10-14 years) from the Public Health Impact of Metals Exposure Study to estimate prospective associations of Mn in three early life exposure periods with adolescent attention-related behaviors.

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Intracellular sensors detect changes in levels of essential metals to initiate homeostatic responses. But, a mammalian manganese (Mn) sensor is unknown, representing a major gap in understanding of Mn homeostasis. Using human-relevant models, we recently reported that: 1) the primary homeostatic response to elevated Mn is upregulation of hypoxia-inducible factors (HIFs), which increases expression of the Mn efflux transporter SLC30A10; and 2) elevated Mn blocks the prolyl hydroxylation of HIFs by prolyl hydroxylase domain (PHD) enzymes, which otherwise targets HIFs for degradation.

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  • * The study found that Mn accumulation in the thyroid correlates with decreased iodine levels, contributing to hypothyroidism in these models.
  • * Differences in Mn sensitivity between mice and rats suggest that thyroid responses to Mn may vary between species, affecting the understanding of Mn-induced diseases in research.
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Background: Metal exposures can adversely impact olfactory function. Few studies have examined this association in children. Further, metal exposure occurs as a mixture, yet previous studies of metal-associated olfactory dysfunction only examined individual metals.

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(BP) is a medicinal plant used to treat many conditions when taken as a leaf juice, leaves in capsules, as an ethanolic extract, and as herbal tea. These preparations have been chemically analyzed except for decoctions derived from boiled green leaves. In preparation for a clinical trial to validate BP tea as a treatment for kidney stones, we used NMR and MS analyses to characterize the saturation kinetics of the release of metabolites.

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Background: Manganese (Mn) plays a significant role in both human health and global industries. Epidemiological studies of exposed populations demonstrate a dose-dependent association between Mn and neuromotor effects ranging from subclinical effects to a clinically defined syndrome. However, little is known about the relationship between early life Mn biomarkers and adolescent postural balance.

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Studies in children have reported associations between elevated manganese (Mn) exposure and ADHD-related symptoms of inattention, impulsivity/hyperactivity, and psychomotor impairment. Maternal choline supplementation (MCS) during pregnancy/lactation may hold promise as a protective strategy because it has been shown to lessen cognitive dysfunction caused by numerous early insults. Our objectives were to determine whether (1) developmental Mn exposure alters behavioral reactivity/emotion regulation, in addition to impairing learning, attention, impulse control, and sensorimotor function, and (2) MCS protects against these Mn-induced impairments.

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Externalizing disorders, such as attention-deficit/hyperactivity disorder (ADHD), account for the majority of the child/adolescent referrals to mental health services and increase risk for later-life psychopathology. Although the expression of externalizing disorders is more common among males, few studies have addressed how sex modifies associations between metal exposure and adolescent externalizing symptoms. This study aimed to examine sex-specific associations between co-exposure to multiple metals and externalizing symptoms in adolescence and young adulthood.

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Background: Exposure to environmental metals has been consistently associated with attention and behavioral deficits in children, and these associations may be modified by coexposure to other metals or iron (Fe) status. However, few studies have investigated Fe status as a modifier of a metal mixture, particularly with respect to attention-related behaviors.

Methods: We used cross-sectional data from the Public Health Impact of Metals Exposure study, which included 707 adolescents (10-14 years of age) from Brescia, Italy.

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Epidemiological studies have reported associations between elevated manganese (Mn) exposure and poorer psychomotor performance in children. Our studies in adult male rats have established that this relationship is causal and that prolonged methylphenidate (MPH) treatment is efficacious in treating this area of dysfunction. However, it is unclear if sensitivity to these Mn deficits differs between females and males, and whether existing pharmacological therapies are efficacious in improving sensorimotor dysfunction in females.

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Environmental manganese (Mn) exposure is associated with impaired attention and psychomotor functioning, as well as impulsivity/hyperactivity in children and adolescents. We have shown previously that developmental Mn exposure can cause these same dysfunctions in a rat model. Methylphenidate (MPH) lessens impairments in attention, impulse control, and psychomotor function in children, but it is unknown whether MPH ameliorates these dysfunctions when induced by developmental Mn exposure.

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Introduction: The assessment of resting state (rs) neurophysiological dynamics relies on the control of sensory, perceptual, and behavioral environments to minimize variability and rule-out confounding sources of activation during testing conditions. Here, we investigated how temporally-distal environmental inputs, specifically metal exposures experienced up to several months prior to scanning, affect functional dynamics measured using rs functional magnetic resonance imaging (rs-fMRI).

Methods: We implemented an interpretable XGBoost-shapley additive explanation (SHAP) model that integrated information from multiple exposure biomarkers to predict rs dynamics in typically developing adolescents.

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Environmental manganese (Mn) exposure is associated with impaired attention and psychomotor functioning, as well as impulsivity/hyperactivity in children and adolescents. We have shown previously that developmental Mn exposure can cause these same dysfunctions in a rat model. Methylphenidate (MPH) lessens impairments in attention, impulse control, and sensorimotor function in children, but it is unknown whether MPH ameliorates these dysfunctions when induced by developmental Mn exposure.

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Background: Manganese (Mn) is both an essential and toxic metal, and associations with neurodevelopment depend on exposure timing. Prospective data examining early life Mn with adolescent cognition are sparse.

Methods: We enrolled 140 Italian adolescents (10-14 years old) from the Public Health Impact of Metals Exposure study.

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Background: Metals, including lead (Pb), manganese (Mn), chromium (Cr) and copper (Cu), have been associated with neurodevelopment; iron (Fe) plays a role in the metabolism and neurotoxicity of metals, suggesting Fe may mediate metal-neurodevelopment associations. However, no study to date has examined Fe as a mediator of the association between metal mixtures and neurodevelopment.

Objective: We assessed Fe status as a mediator of a mixture of Pb, Mn, Cr and Cu in relation to verbal learning and memory in a cohort of Italian adolescents.

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Pseudomonas entomophila strain 23S is an effective biocontrol bacterium for tomato bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (Cmm); it produces an inhibitory compound affecting the growth of Cmm. In this study, the interactions between pure cultures of P.

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Salt stress can affect survival, multiplication and ability of plant growth promoting microorganisms to enhance plant growth. Changes in a microbe's proteome profile is one of the mechanisms employed by PGPM to enhance tolerance of salt stress. This study was focused on understanding changes in the exoproteome profile of EB2003A and EL2006H when exposed to salt stress.

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Lipo-chito-oligosaccharide (LCO-from ) and thuricin 17 (Th17-from ) are bacterial signal compounds from the rhizosphere of soybean that have been shown to enhance plant growth in a range of legumes and non-legumes. In this study, an attempt to quantify phytohormones involved in the initial hours after exposure of to these compounds was conducted using UPLC-ESI-MS/MS. A petri-plate assay was conducted to screen for drought stress tolerance to PEG 8000 infusion and plant growth was studied 21-days post-stress.

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This review provides a summary of the recently ratified changes to genus and species nomenclature within the virus family Flaviviridae along with reasons for these changes. First, it was considered that the vernacular terms "flaviviral", "flavivirus", and "flaviviruses" could under certain circumstances be ambiguous due to the same word stem "flavi" in the taxon names Flaviviridae and Flavivirus; these terms could either have referred to all viruses classified in the family Flaviviridae or only to viruses classified in the included genus Flavivirus. To remove this ambiguity, the genus name Flavivirus was changed to Orthoflavivirus by the International Committee on Taxonomy of Viruses (ICTV).

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