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1.
Sci Rep ; 14(1): 3021, 2024 02 06.
Article in English | MEDLINE | ID: mdl-38321123

ABSTRACT

The initiation of alcohol use early in life is one of the strongest predictors of developing a future alcohol use disorder. Clinical studies have identified specific behaviors during early childhood that predict an increased risk for excess alcohol consumption later in life. These behaviors, including increased hyperactivity, anxiety, novelty-seeking, exploratory behavior, impulsivity, and alcohol-seeking, are similarly stimulated in children and adolescent offspring of mothers who drink alcohol during pregnancy. Here we tested larval zebrafish in addition to young pre-weanling rats and found this repertoire of early behaviors along with the overconsumption of alcohol during adolescence to be increased by embryonic ethanol exposure. With hypocretin/orexin (Hcrt) neurons known to be stimulated by ethanol and involved in mediating these alcohol-related behaviors, we tested their function in larval zebrafish and found optogenetic activation of Hcrt neurons to stimulate these same early alcohol-related behaviors and later alcohol intake, suggesting that these neurons have an important role in producing these behaviors. Together, these results show zebrafish to be an especially useful animal model for investigating the diverse neuronal systems mediating behavioral changes at young ages that are produced by embryonic ethanol exposure and predict an increased risk for developing alcohol use disorder.


Subject(s)
Alcoholism , Ethanol , Child, Preschool , Humans , Pregnancy , Female , Child , Animals , Rats , Adolescent , Orexins/genetics , Zebrafish , Optogenetics , Alcohol Drinking , Neurons
2.
Article in English | MEDLINE | ID: mdl-35176416

ABSTRACT

Prenatal alcohol exposure (PAE) increases alcohol consumption and risk for alcohol use disorder. This phenomenon in rodents is suggested to involve a stimulatory effect of PAE, in female more than male offspring, on neurogenesis and density of neurons expressing neuropeptides in lateral hypothalamus (LH), including melanin-concentrating hormone (MCH), known to promote alcohol intake. With evidence suggesting a role for fibroblast growth factor 2 (FGF2) and its receptor FGFR1 in stimulating neurogenesis and alcohol drinking, we investigated here whether the FGF2-FGFR1 system is involved in the PAE-induced increase in MCH neurons, in postnatal offspring of pregnant rats given ethanol orally (embryonic day 10-15) at a low-moderate (2 g/kg/day) or high (5 g/kg/day) dose. Our results demonstrate that PAE at the low-moderate but not high dose stimulates FGF2 and FGFR1 gene expression and increases the density of MCH neurons co-expressing FGF2, only in females, but FGFR1 in both sexes. PAE induces this effect in the dorsal but not ventral area of the LH. Further analysis of FGF2 and FGFR1 transcripts within individual MCH neurons reveals an intracellular, sex-dependent effect, with PAE increasing FGF2 transcripts positively related to FGFR1 in the nucleus as well as cytoplasm of females but transcripts only in the cytoplasm of males. Peripheral injection of FGF2 itself (80 µg/kg, s.c.) in pregnant rats mimics these effects of PAE. Together, these results support the involvement of the FGF2-FGFR1 system in mediating the PAE-induced, sex dependent increase in density of MCH neurons, possibly contributing to increased alcohol consumption in the offspring.


Subject(s)
Fibroblast Growth Factor 2 , Prenatal Exposure Delayed Effects , Animals , Ethanol , Female , Fibroblast Growth Factor 2/adverse effects , Fibroblast Growth Factor 2/metabolism , Male , Neurons , Peptides/pharmacology , Pregnancy , Prenatal Exposure Delayed Effects/chemically induced , Rats , Rats, Sprague-Dawley
3.
Sci Rep ; 11(1): 16078, 2021 08 09.
Article in English | MEDLINE | ID: mdl-34373563

ABSTRACT

Neurons expressing the neuropeptide hypocretin/orexin (Hcrt) in the hypothalamus promote reward-related behaviors including alcohol consumption and are shown in rodents and zebrafish to be stimulated by embryonic exposure to ethanol (EtOH). We used here in zebrafish three-dimensional analyses of the entire population of Hcrt neurons to examine how embryonic EtOH exposure at low-moderate concentrations (0.1% or 0.5% v/v) alters these neurons in relation to behavior. We found that EtOH in the water for 2 h (22-24 h post fertilization) increases the number of Hcrt neurons on the left but not right side of the brain through a stimulation of cell proliferation, this is accompanied by a decrease in locomotor activity under novel conditions but not after habituation, and these effects are evident in both larvae and adults indicating they are long lasting. Our analyses in adults revealed sexually dimorphic effects, with females consuming more EtOH-gelatin and exhibiting more freezing behavior along with an asymmetric increase in Hcrt neurons and males exhibiting increased aggression with no change in Hcrt. These findings suggest that a long lasting, asymmetric increase in Hcrt neurons induced by EtOH results from an asymmetric increase in proliferation specific to Hcrt and contributes to behavioral changes in females.


Subject(s)
Behavior, Animal/drug effects , Embryo, Nonmammalian/drug effects , Ethanol/pharmacology , Neurons/drug effects , Orexins/metabolism , Zebrafish/metabolism , Animals , Animals, Genetically Modified/metabolism , Cell Proliferation/drug effects , Embryo, Nonmammalian/metabolism , Female , Hypothalamus/drug effects , Hypothalamus/metabolism , Locomotion/drug effects , Male , Neurons/metabolism , Neuropeptides/metabolism , Sex Characteristics
4.
Intern Med J ; 50(12): 1538-1546, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33174353

ABSTRACT

BACKGROUND: Gaucher disease (GD) manifests heterogeneously and other conditions are often misdiagnosed in its place, leading to diagnostic delays. The Gaucher Earlier Diagnosis Consensus (GED-C) initiative proposed a point-scoring system (PSS) based on the signs and covariables that are most indicative of GD to help clinicians identify which individuals to test for GD. AIMS: To validate the PSS retrospectively in a test population including patients with GD and other conditions with overlapping manifestations. METHODS: Four cohorts of adults with GD, liver disease, haematological malignancy or immune thrombocytopenia were identified from hospital records. Clinical data were audited for GED-C factors identified as potentially indicative of GD and aggregate scores calculated (sum of scores/number of factors) based on published PSS weightings. Threshold discriminatory PSS scores, sensitivity and specificity were determined by receiver-operating characteristic analysis. RESULTS: Among 100 patients (GD, n = 25; non-GD, n = 75), analyses based on 11 possible factors estimated group mean (standard deviation) PSS scores of: GD (n = 14), 1.08 (0.25); non-GD (n = 38), 0.58 (0.31). Mean between-group difference (95% confidence interval) was -0.49 (-0.68, -0.31) and area under the receiver-operating characteristic analysis curve (95% confidence interval) was 0.88 (0.78, 0.97). A threshold PSS score of 0.82 identified all 14 patients with GD in the analysis set (100% sensitivity) and 27 of 38 patients in the non-GD group (71% specificity). Patients with liver disease and haematological malignancy were most likely to have manifestations overlapping GD. CONCLUSIONS: Preliminary validation of the GED-C PSS discriminated effectively between patients with GD and those with overlapping signs.


Subject(s)
Gaucher Disease , Adult , Early Diagnosis , Gaucher Disease/diagnosis , Gaucher Disease/epidemiology , Humans , ROC Curve , Retrospective Studies , Sensitivity and Specificity
5.
Alcohol Clin Exp Res ; 44(12): 2519-2535, 2020 12.
Article in English | MEDLINE | ID: mdl-33067812

ABSTRACT

BACKGROUND: Embryonic exposure to ethanol (EtOH) produces marked disturbances in neuronal development and alcohol-related behaviors, with low-moderate EtOH doses stimulating neurogenesis without producing apoptosis and high doses having major cytotoxic effects while causing gross morphological abnormalities. With the pro-inflammatory chemokine system, Cxcl12, and its main receptor Cxcr4, known to promote processes of neurogenesis, we examined here this neuroimmune system in the embryonic hypothalamus to test directly if it mediates the stimulatory effects low-moderate EtOH doses have on neuronal development. METHODS: We used the zebrafish (Danio rerio) model, which develops externally and allows one to investigate the developing brain in vivo with precise control of dose and timing of EtOH delivery in the absence of maternal influence. Zebrafish were exposed to low-moderate EtOH doses (0.1, 0.25, 0.5% v/v), specifically during a period of peak hypothalamic development from 22 to 24 hours postfertilization, and in some tests were pretreated from 2 to 22 hpf with the Cxcr4 receptor antagonist, AMD3100. Measurements in the hypothalamus at 26 hpf were taken of cxcl12a and cxcr4b transcription, signaling, and neuronal density using qRT-PCR, RNAscope, and live imaging of transgenic zebrafish. RESULTS: Embryonic EtOH exposure, particularly at the 0.5% dose, significantly increased levels of cxcl12a and cxcr4b mRNA in whole embryos, number of cxcl12a and cxcr4b transcripts in developing hypothalamus, and internalization of Cxcr4b receptors in hypothalamic cells. Embryonic EtOH also caused an increase in the number of hypothalamic neurons and coexpression of cxcl12a and cxcr4b transcripts within these neurons. Each of these stimulatory effects of EtOH in the embryo was blocked by pretreatment with the Cxcr4 antagonist AMD3100. CONCLUSIONS: These results provide clear evidence that EtOH's stimulatory effects at low-moderate doses on the number of hypothalamic neurons early in development are mediated, in part, by increased transcription and intracellular activation of this chemokine system, likely due to autocrine signaling of Cxcl12a at its Cxcr4b receptor within the neurons.


Subject(s)
Chemokine CXCL12/metabolism , Ethanol/pharmacology , Hypothalamus/drug effects , Neurons/drug effects , Receptors, CXCR4/metabolism , Zebrafish Proteins/metabolism , Animals , Benzylamines/pharmacology , Cell Count , Cyclams/pharmacology , Embryo, Nonmammalian/drug effects , Hypothalamus/cytology , Hypothalamus/embryology , Neurogenesis/drug effects , Zebrafish/embryology
6.
Methods Mol Biol ; 2116: 225-262, 2020.
Article in English | MEDLINE | ID: mdl-32221924

ABSTRACT

Understanding the rate and patterns of genome variation is becoming ever more amenable to whole-genome analysis through advances in DNA sequencing, which may, at least in some circumstances, have supplanted more localized analyses by cellular and genetic approaches. Whole-genome analyses can utilize both short- and long-read sequence technologies. Here we describe how sequence generated by these approaches has been used in trypanosomatids to examine DNA replication dynamics, the accumulation of modified histone H2A due to genome damage, and evaluation of genome variation, focusing on ploidy change.


Subject(s)
Genome, Protozoan/genetics , Genomic Instability , High-Throughput Nucleotide Sequencing , Leishmania major/genetics , Sequence Analysis, DNA , Chromosomes/genetics , Computational Biology/methods , DNA Copy Number Variations , DNA, Protozoan/genetics , Datasets as Topic , Histones/genetics , Parasitology/methods
7.
Clin Infect Dis ; 71(9): e506-e508, 2020 12 03.
Article in English | MEDLINE | ID: mdl-32109275

ABSTRACT

In a retrospective, quasi-experimental study of 380 adult patients with a reported penicillin allergy who received antibiotics at a community hospital emergency department, a pharmacist-led penicillin allergy assessment via medical records review and patient interview improved guideline-preferred antibiotic use by 13% (P = .018) and reduced fluoroquinolone use by 11% (P = .035).


Subject(s)
Drug Hypersensitivity , Penicillins , Adult , Anti-Bacterial Agents/adverse effects , Drug Hypersensitivity/diagnosis , Emergency Service, Hospital , Fluoroquinolones/adverse effects , Humans , Penicillins/adverse effects , Pharmacists , Retrospective Studies
8.
Article in English | MEDLINE | ID: mdl-31394141

ABSTRACT

There are numerous clinical and pre-clinical studies showing that exposure of the embryo to ethanol markedly affects neuronal development and stimulates alcohol drinking and related behaviors. In rodents and zebrafish, our studies show that embryonic exposure to low-dose ethanol, in addition to increasing voluntary ethanol intake during adolescence, increases the density of hypothalamic hypocretin (hcrt) neurons, a neuropeptide known to regulate reward-related behaviors. The question addressed here in zebrafish is whether maternal ethanol intake before conception also affects neuronal and behavioral development, phenomena suggested by clinical reports but seldom investigated. To determine if preconception maternal ethanol consumption also affects these hcrt neurons and behavior in the offspring, we first standardized a method of measuring voluntary ethanol consumption in AB strain adult and larval zebrafish given gelatin meals containing 10% or 0.1% ethanol, respectively. We found the number of bites of gelatin to be an accurate measure of intake in adults and a strong predictor of blood ethanol levels, and also to be a reliable indicator of intake in larval zebrafish. We then used this feeding paradigm and live imaging to examine the effects of preconception maternal intake of 10% ethanol-gelatin compared to plain-gelatin for 14 days on neuronal development in the offspring. Whereas ethanol consumption by adult female HuC:GFP transgenic zebrafish had no impact on the number of differentiated HuC+ neurons at 28 h post-fertilization (hpf), preconception ethanol consumption by adult female hcrt:EGFP zebrafish significantly increased the number of hcrt neurons in the offspring, an effect observed at 28 hpf and confirmed at 6 and 12 days post-fertilization (dpf). This increase in hcrt neurons was primarily present on the left side of the brain, indicating asymmetry in ethanol's actions, and it was accompanied by behavioral changes in the offspring, including a significant increase in novelty-induced locomotor activity but not thigmotaxis measured at 6 dpf and also in voluntary consumption of 0.1% ethanol-gelatin at 12 dpf. Notably, these measures of ethanol intake and locomotor activity stimulated by preconception ethanol were strongly, positively correlated with the number of hcrt neurons. These findings demonstrate that preconception maternal ethanol consumption affects the brain and behavior of the offspring, producing effects similar to those caused by embryonic ethanol exposure, and they provide further evidence that the ethanol-induced increase in hcrt neurogenesis contributes to the behavioral disturbances caused by ethanol.


Subject(s)
Alcohol Drinking/trends , Ethanol/administration & dosage , Fertilization/physiology , Neurogenesis/physiology , Orexins/metabolism , Prenatal Exposure Delayed Effects/metabolism , Alcohol Drinking/adverse effects , Animals , Animals, Genetically Modified , Ethanol/adverse effects , Female , Fertilization/drug effects , Locomotion/drug effects , Locomotion/physiology , Male , Neurogenesis/drug effects , Pregnancy , Prenatal Exposure Delayed Effects/chemically induced , Zebrafish
9.
F1000Res ; 82019.
Article in English | MEDLINE | ID: mdl-31448080

ABSTRACT

The era of biologic agents for the treatment of Crohn's disease has brought about significant benefits for patients, and since the introduction of infliximab at the turn of the century, the entire field has moved on rapidly. Clinicians now have multiple agents at their disposal and a choice between several different anti-inflammatory mechanisms of action. This has allowed unprecedented improvements not only in symptoms and quality of life for patients previously refractory to conventional treatments but also for demonstrated healing of the intestinal mucosa and resolution of perianal fistulation. However, despite the undisputed efficacy of these agents, there remains a significant proportion of patients who fail to gain a meaningful benefit. Through years of studying infliximab and its counterpart anti-tumour necrosis factor (anti-TNF) agent, adalimumab, we now understand that strategies such as combining use with a conventional immunomodulator or measuring serum levels can help to optimise outcomes and reduce the proportion of patients for whom treatment fails. Work is ongoing to understand whether these principles apply to newer biologics such as vedolizumab and ustekinumab. In addition, novel approaches are being investigated in an attempt to maximise the benefit that these agents could offer. In this article, we summarise these new understandings and consider ways in which they could be integrated into clinical practice for the benefit of patients.


Subject(s)
Biological Therapy , Crohn Disease , Antibodies, Monoclonal , Crohn Disease/therapy , Humans , Quality of Life , Tumor Necrosis Factor-alpha
10.
Alcohol Clin Exp Res ; 43(8): 1702-1713, 2019 08.
Article in English | MEDLINE | ID: mdl-31206717

ABSTRACT

BACKGROUND: Embryonic ethanol (EtOH) exposure is known to increase alcohol drinking later in life and have long-term effects on neurochemical systems in the brain. With zebrafish having marked advantages for elucidating neural mechanisms underlying brain disorders, we recently tested and showed in these fish, similar to rodents, that low-dose embryonic EtOH stimulates voluntary consumption of EtOH while increasing expression of hypocretin/orexin (hcrt) neurons, a neuropeptide that promotes consummatory and reward-related behaviors. The goal of the present study was to characterize how embryonic EtOH affects early development of the hcrt system and produces persistent changes at older ages that may contribute to this increase in EtOH consumption. METHODS: We utilized live imaging and Imaris software to investigate how low-dose embryonic EtOH (0.5%), administered from 22 to 24 hours postfertilization, affects specific properties of hcrt neurons in hcrt:EGFP transgenic zebrafish at different ages. RESULTS: Time-lapse imaging from 24 to 28 hpf showed that embryonic EtOH increased the number of hcrt neurons, reduced the speed, straightness, and displacement of their migratory paths, and altered their direction early in development. At older ages up to 6 dpf, the embryonic EtOH-induced increase in hcrt neurons was persistent, and the neurons became more widely dispersed. These effects of embryonic EtOH were found to be asymmetric, occurring predominantly on the left side of the brain, and at 6 dpf, they resulted in marked changes in the anatomical location of the hcrt neurons, with some detected outside their normal position in the anterior hypothalamus again primarily on the left side. CONCLUSIONS: Our findings demonstrate that low-dose embryonic EtOH has diverse, persistent, and asymmetric effects on the early development of hypothalamic hcrt neurons, which lead to abnormalities in their ultimate location that may contribute to behavioral disturbances, including an increase in EtOH consumption.


Subject(s)
Alcohol Drinking/physiopathology , Cell Movement/drug effects , Embryo, Nonmammalian/drug effects , Ethanol/adverse effects , Hypothalamus, Anterior/growth & development , Orexins/physiology , Aging/physiology , Animals , Animals, Genetically Modified , Cell Count/statistics & numerical data , Dominance, Cerebral/physiology , Hypothalamus, Anterior/anatomy & histology , Neurons/physiology , Orexins/drug effects , Orexins/genetics , Zebrafish
11.
J Crohns Colitis ; 13(6): 735-743, 2019 May 27.
Article in English | MEDLINE | ID: mdl-30590513

ABSTRACT

BACKGROUND AND AIMS: There are no universally accepted guidelines regarding surveillance of ulcerative colitis [UC] patients after restorative proctocolectomy and ileal pouch-anal anastomosis [IPAA]. There also exists a lack of validated quality assurance standards for performing pouchoscopy. To better understand IPAA surveillance practices in the face of this clinical equipoise, we carried out a retrospective cohort study at five inflammatory bowel disease [IBD] referral centres. METHODS: Records of patients who underwent IPAA for UC or IBD unclassified [IBDU] were reviewed, and patients with <1-year follow-up after restoration of intestinal continuity were excluded. Criteria for determining the risk of pouch dysplasia formation were collected as well as the use of pouchoscopy, biopsies, and completeness of reports. RESULTS: We included 272 patients. Median duration of pouch follow-up was 10.5 [3.3-23.6] years; 95/272 [35%] had never undergone pouchoscopy for any indication; 191/272 [70%] had never undergone pouchoscopy with surveillance as the specific indication; and 3/26 [12%] high-risk patients had never undergone pouchoscopy. Two cases of adenocarcinoma were identified, occurring in the rectal cuff of low-risk patients. Patients under the care of surgeons appeared more likely to undergo surveillance, but rates of incomplete reporting were higher among surgeons [78%] than gastroenterologists [54%, p = 0.002]. CONCLUSIONS: We observed wide variation in surveillance of UC/IBDU-IPAA patients. In addition, the rate of neoplasia formation among 'low-risk' patients was higher than may have been expected. We therefore concur with previous recommendations that pouchoscopy be performed at 1 year postoperatively, to refine risk-stratification based on clinical factors alone. Reports should document findings in all regions of the pouch and biopsies should be taken.


Subject(s)
Colitis, Ulcerative/diagnosis , Pouchitis/diagnosis , Proctocolectomy, Restorative , Colitis, Ulcerative/pathology , Colitis, Ulcerative/surgery , Endoscopy, Gastrointestinal , Female , Humans , Male , Middle Aged , Pouchitis/pathology , Retrospective Studies
12.
Transplant Direct ; 4(6): e352, 2018 Jun.
Article in English | MEDLINE | ID: mdl-30123825

ABSTRACT

BACKGROUND: Low clearance transplant clinics (LCTCs) are recommended for the management of recipients with a failing kidney transplant (RFKT) but data to support their use is limited. We conducted a retrospective study to assess management of RFKT at 2 transplant centers, 1 with a LCTC (center A) and 1 without (center B). METHODS: Patients who transitioned to an alternative form of renal replacement therapy (RRT) between January 1, 2012, and November 30, 2016, were included. Patients with graft failure within a year of transplantation or due to an unpredictable acute event were excluded. Clinical data were collected after review of medical records. RESULTS: One hundred seventy-nine patients (age, 48.6 ± 13.4 years, 99 [55.3%] male, and mean transplant duration 10.3 ± 7.8 years) were included. RRT counseling occurred in 79 (91%) and 68 (74%) patients at centers A and B (P = 0.003), at median 135 (61-319) and 133 (69-260) days before dialysis after graft loss (P = 0.92). Sixty-one (34.1%) patients were waitlisted for retransplantation; 18 (32.7%) nonwaitlisted patients were still undergoing workup at center A compared with 37 (58.7%) at center B (P = 0.028). Preemptive retransplantation occurred in 4 (4.6%) and 5 (5.4%) patients at centers A and B (P = 0.35). At 1 year after initiation of dialysis after graft loss, 11 (15.3%) and 11 (17.2%) patients were retransplanted (P = 0.12), and mortality was 6.6% overall. CONCLUSIONS: A dedicated LCTC improved RRT counseling and transplant work-up but did not lead to improved rates of retransplantation. Earlier consideration of retransplantation in LCTCs is required to improve RFKT outcomes.

13.
Elife ; 52016 05 26.
Article in English | MEDLINE | ID: mdl-27228154

ABSTRACT

Survival of Trypanosoma brucei depends upon switches in its protective Variant Surface Glycoprotein (VSG) coat by antigenic variation. VSG switching occurs by frequent homologous recombination, which is thought to require locus-specific initiation. Here, we show that a RecQ helicase, RECQ2, acts to repair DNA breaks, including in the telomeric site of VSG expression. Despite this, RECQ2 loss does not impair antigenic variation, but causes increased VSG switching by recombination, arguing against models for VSG switch initiation through direct generation of a DNA double strand break (DSB). Indeed, we show DSBs inefficiently direct recombination in the VSG expression site. By mapping genome replication dynamics, we reveal that the transcribed VSG expression site is the only telomeric site that is early replicating - a differential timing only seen in mammal-infective parasites. Specific association between VSG transcription and replication timing reveals a model for antigenic variation based on replication-derived DNA fragility.


Subject(s)
Antigenic Variation , DNA Replication , Telomere/metabolism , Transcription, Genetic , Trypanosoma brucei brucei/genetics , Trypanosoma brucei brucei/metabolism , Variant Surface Glycoproteins, Trypanosoma/biosynthesis , DNA Breaks , DNA Repair , RecQ Helicases/metabolism
14.
J Sport Rehabil ; 25(3): 288-93, 2016 Aug.
Article in English | MEDLINE | ID: mdl-25946512

ABSTRACT

CLINICAL SCENARIO: Patellofemoral pain syndrome (PFPS) occurs in 25% of adolescents and adults and is the leading cause of knee pain in runners. Pain is commonly felt when ascending or descending stairs, deep squatting, kneeling, or running. There is no consensus on the etiology of this condition, but insufficient hip strength, malalignment of the lower extremity, hyperpronation of the foot, and patellar incongruence have been suggested. Common treatments of PFPS include strengthening of quadriceps and hip muscles, McConnell taping, electrical stimulation, and foot orthotics, but effectiveness of these treatments is inconclusive. Kinesio Taping is an alternative taping technique for musculoskeletal injuries including PFPS. Although research suggests that Kinesio Taping decreases pain and improves range of motion for some musculoskeletal injuries, its effectiveness in decreasing pain in patients with PFPS in unknown. Furthermore, Kinesio Taping has not been compared with other taping techniques including McConnell taping. Focused Clinical Question: For patients with anterior knee pain consistent with PFPS, does treatment with Kinesio Taping decrease pain more than McConnell taping or no tape at all?


Subject(s)
Athletic Tape , Patellofemoral Pain Syndrome/therapy , Physical Therapy Modalities , Humans , Pain Measurement , Patellofemoral Pain Syndrome/diagnosis , Physical Therapy Modalities/instrumentation , Treatment Outcome
15.
Genome Biol ; 16: 230, 2015 Oct 19.
Article in English | MEDLINE | ID: mdl-26481451

ABSTRACT

BACKGROUND: DNA replication initiates on defined genome sites, termed origins. Origin usage appears to follow common rules in the eukaryotic organisms examined to date: all chromosomes are replicated from multiple origins, which display variations in firing efficiency and are selected from a larger pool of potential origins. To ask if these features of DNA replication are true of all eukaryotes, we describe genome-wide origin mapping in the parasite Leishmania. RESULTS: Origin mapping in Leishmania suggests a striking divergence in origin usage relative to characterized eukaryotes, since each chromosome appears to be replicated from a single origin. By comparing two species of Leishmania, we find evidence that such origin singularity is maintained in the face of chromosome fusion or fission events during evolution. Mapping Leishmania origins suggests that all origins fire with equal efficiency, and that the genomic sites occupied by origins differ from related non-origins sites. Finally, we provide evidence that origin location in Leishmania displays striking conservation with Trypanosoma brucei, despite the latter parasite replicating its chromosomes from multiple, variable strength origins. CONCLUSIONS: The demonstration of chromosome replication for a single origin in Leishmania, a microbial eukaryote, has implications for the evolution of origin multiplicity and associated controls, and may explain the pervasive aneuploidy that characterizes Leishmania chromosome architecture.


Subject(s)
Chromosomes , Leishmania/genetics , Replication Origin , Chromosome Mapping , Genetic Loci , Genome, Protozoan , Leishmania major/genetics , Trypanosoma brucei brucei/genetics
16.
New Phytol ; 201(4): 1498-1507, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24304557

ABSTRACT

• Divergence in flowering time is a key contributor to reproductive isolation between incipient species, as it enforces habitat specialization and causes assortative mating even in sympatry. Understanding the genetic basis of flowering time divergence illuminates the origins and maintenance of species barriers. • We investigated the genetics of divergence in critical photoperiod for flowering between yellow monkeyflowers Mimulus guttatus (outcrosser, summer flowering) and Mimulus nasutus (selfer, spring flowering). We used quantitative trait locus (QTL) mapping of F2 hybrids and fine-mapping in nearly isogenic lines to characterize the genomic regions underlying a > 2 h critical photoperiod difference between allopatric populations, and then tested whether the same QTLs control flowering time in sympatry. • We identified two major QTLs that almost completely explain M. nasutus's ability to flower in early spring; they are shared by allopatric and sympatric population pairs. The smaller QTL is coincident with one that differentiates ecotypes within M. guttatus, but the larger effect QTL appears unique to M. nasutus. • Unlike floral traits associated with mating system divergence, large interspecific differences in flowering phenology depend on only a few loci. Major critical photoperiod QTLs may be 'speciation genes' and also restrict interspecific gene flow in secondary sympatry.


Subject(s)
Crosses, Genetic , Flowers/genetics , Flowers/physiology , Genetic Variation , Photoperiod , Quantitative Trait Loci/genetics , Chromosome Segregation/genetics , Genetic Association Studies , Hybridization, Genetic , Phenotype , Physical Chromosome Mapping , Sympatry
17.
Environ Microbiol Rep ; 5(1): 170-8, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23757146

ABSTRACT

We report on the characterization and genomic analysis of bacteriophage E3 isolated from soil and propagating in Rhodococcus equi strains. Phage E3 has a circular genome of 142 563 bp and is the first Myoviridae reported for the genus Rhodococcus and for a non-mycobacterial actinomycete. Phylogenetic analyses placed E3 in a distinct Myoviridae clade together with Mycobacterium phages Bxz1 and Myrna. The highly syntenic genomes of this myoviridal group comprise vertically evolving core phage modules flanked by hyperplastic regions specific to each phage and rich in horizontally acquired DNA. The hyperplastic regions contain numerous tRNA genes in the mycobacteriophages which are absent in E3, possibly reflecting bacterial host-specific translation-related phage fitness constraints associated with rate-limiting tRNAs. A structural proteome analysis identified 28 E3 polypeptides, including 15 not previously known to be virion-associated proteins. The E3 genome and comparative analysis provide insight into short-term genome evolution and adaptive plasticity in tailed phages from the environmental microbiome.


Subject(s)
Bacteriophages/genetics , Genome, Viral , Myoviridae/genetics , Proteome/analysis , Rhodococcus equi/virology , Bacteriophages/isolation & purification , DNA, Viral/genetics , Myoviridae/isolation & purification , Open Reading Frames , Phylogeny , Proteome/genetics , Proteomics/methods , Sequence Analysis, DNA , Soil Microbiology , Viral Proteins/genetics , Virion/genetics
18.
J Clin Exp Neuropsychol ; 34(8): 791-805, 2012.
Article in English | MEDLINE | ID: mdl-22624705

ABSTRACT

Two studies addressed how young adult college students with attention deficit hyperactivity disorder (ADHD) (n = 44) compare to their nonaffected peers (n = 42) on tests of auditory and visual-spatial working memory (WM), are vulnerable to auditory and visual distractions, and are affected by a simple intervention. Students with ADHD demonstrated worse auditory WM than did controls. A near significant trend indicated that auditory distractions interfered with the visual WM of both groups and that, whereas controls were also vulnerable to visual distractions, visual distractions improved visual WM in the ADHD group. The intervention was ineffective. Limited correlations emerged between self-reported ADHD symptoms and objective test performances; students with ADHD who perceived themselves as more symptomatic often had better WM and were less vulnerable to distractions than their ADHD peers.


Subject(s)
Attention Deficit Disorder with Hyperactivity/complications , Memory Disorders/etiology , Memory Disorders/rehabilitation , Memory, Short-Term/physiology , Space Perception/physiology , Students/psychology , Acoustic Stimulation , Adolescent , Analysis of Variance , Female , Humans , Male , Neuropsychological Tests , Photic Stimulation , Psychiatric Status Rating Scales , Statistics as Topic , Surveys and Questionnaires , Time Factors , Universities , Verbal Learning , Young Adult
19.
Eukaryot Cell ; 5(9): 1517-31, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16963634

ABSTRACT

Currently the shikimate pathway is reported as a metabolic feature of prokaryotes, ascomycete fungi, apicomplexans, and plants. The plant shikimate pathway enzymes have similarities to prokaryote homologues and are largely active in chloroplasts, suggesting ancestry from the plastid progenitor genome. Toxoplasma gondii, which also possesses an alga-derived plastid organelle, encodes a shikimate pathway with similarities to ascomycete genes, including a five-enzyme pentafunctional arom. These data suggests that the shikimate pathway and the pentafunctional arom either had an ancient origin in the eukaryotes or was conveyed by eukaryote-to-eukaryote horizontal gene transfer (HGT). We expand sampling and analyses of the shikimate pathway genes to include the oomycetes, ciliates, diatoms, basidiomycetes, zygomycetes, and the green and red algae. Sequencing of cDNA from Tetrahymena thermophila confirmed the presence of a pentafused arom, as in fungi and T. gondii. Phylogenies and taxon distribution suggest that the arom gene fusion event may be an ancient eukaryotic innovation. Conversely, the Plantae lineage (represented here by both Viridaeplantae and the red algae) acquired different prokaryotic genes for all seven steps of the shikimate pathway. Two of the phylogenies suggest a derivation of the Plantae genes from the cyanobacterial plastid progenitor genome, but if the full Plantae pathway was originally of cyanobacterial origin, then the five other shikimate pathway genes were obtained from a minimum of two other eubacterial genomes. Thus, the phylogenies demonstrate both separate HGTs and shared derived HGTs within the Plantae clade either by primary HGT transfer or secondarily via the plastid progenitor genome. The shared derived characters support the holophyly of the Plantae lineage and a single ancestral primary plastid endosymbiosis. Our analyses also pinpoints a minimum of 50 gene/domain loss events, demonstrating that loss and replacement events have been an important process in eukaryote genome evolution.


Subject(s)
Evolution, Molecular , Phylogeny , Shikimic Acid/metabolism , Alcohol Oxidoreductases/genetics , Alcohol Oxidoreductases/metabolism , Amino Acids, Aromatic/biosynthesis , Animals , Bacteria/genetics , Bacteria/metabolism , Eukaryota/genetics , Eukaryota/metabolism , Eukaryotic Cells/metabolism , Fungi/genetics , Fungi/metabolism , Gene Fusion/genetics , Gene Transfer, Horizontal/genetics , Hydro-Lyases/genetics , Hydro-Lyases/metabolism , Lyases/genetics , Lyases/metabolism , Models, Genetic , Multienzyme Complexes/genetics , Multienzyme Complexes/metabolism , Phosphotransferases (Alcohol Group Acceptor)/genetics , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Plants/genetics , Plants/metabolism , Prokaryotic Cells/metabolism , Symbiosis/genetics , Transferases/genetics , Transferases/metabolism
20.
Int J Neurosci ; 116(7): 871-7, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16861152

ABSTRACT

This past year the 160th anniversary of the discovery of nitrous oxide as an analgesic/psychotropic anesthetic by an American dentist, Horace Wells, was celebrated in Hartford, Connecticut, USA. This useful gas has been in continuous use longer than any other anesthetic agent and has withstood the test of time. Applications in clinical practice over a variety of health disciplines are presented. This article provides technique guidelines for the administration of nitrous oxide/oxygen sedation to maximize and to customize individual gas dosages for optimal psychotropic and analgesic efficacy. Titration will be discussed with the intent for this manuscript to enable the proper concepts for nitrous oxide/oxygen administration and to customize individual gas dosages to achieve optimal doses of nitrous oxide consistent with psychotropic analgesic nitrous oxide (PAN).


Subject(s)
Analgesics, Non-Narcotic/administration & dosage , Anesthesia, Inhalation/methods , Drug Delivery Systems , Nitrous Oxide/administration & dosage , Analgesia, Patient-Controlled , Drug Delivery Systems/standards , Drug Delivery Systems/statistics & numerical data , Humans , Practice Guidelines as Topic , Titrimetry
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