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1.
Microorganisms ; 9(3)2021 Feb 26.
Article En | MEDLINE | ID: mdl-33652895

BACKGROUND: The 2014-2016 Ebola outbreak in West Africa recapitulated that nosocomial spread of Ebola virus could occur and that health care workers were at particular risk including notable cases in Europe and North America. These instances highlighted the need for centers to better prepare for potential Ebola virus cases; including understanding how the virus spreads and which interventions pose the greatest risk. METHODS: We created a fully equipped intensive care unit (ICU), within a Biosafety Level 4 (BSL4) laboratory, and infected multiple sedated non-human primates (NHPs) with Ebola virus. While providing bedside care, we sampled blood, urine, and gastric residuals; as well as buccal, ocular, nasal, rectal, and skin swabs, to assess the risks associated with routine care. We also assessed the physical environment at end-point. RESULTS: Although viral RNA was detectable in blood as early as three days post-infection, it was not detectable in the urine, gastric fluid, or swabs until late-stage disease. While droplet spread and fomite contamination were present on a few of the surfaces that were routinely touched while providing care in the ICU for the infected animal, these may have been abrogated through good routine hygiene practices. CONCLUSIONS: Overall this study has helped further our understanding of which procedures may pose the highest risk to healthcare providers and provides temporal evidence of this over the clinical course of disease.

3.
Intensive Care Med Exp ; 7(1): 54, 2019 Sep 13.
Article En | MEDLINE | ID: mdl-31520194

BACKGROUND: There are currently limited data for the use of specific antiviral therapies for the treatment of Ebola virus disease (EVD). While there is anecdotal evidence that supportive care may be effective, there is a paucity of direct experimental data to demonstrate a role for supportive care in EVD. We studied the impact of ICU-level supportive care interventions including fluid resuscitation, vasoactive medications, blood transfusion, hydrocortisone, and ventilator support on the pathophysiology of EVD in rhesus macaques infected with a universally lethal dose of Ebola virus strain Makona C07. METHODS: Four NHPs were infected with a universally lethal dose Ebola virus strain Makona, in accordance with the gold standard lethal Ebola NHP challenge model. Following infection, the following therapeutic interventions were employed: continuous bedside supportive care, ventilator support, judicious fluid resuscitation, vasoactive medications, blood transfusion, and hydrocortisone as needed to treat cardiovascular compromise. A range of physiological parameters were continuously monitored to gage any response to the interventions. RESULTS: All four NHPs developed EVD and demonstrated a similar clinical course. All animals reached a terminal endpoint, which occurred at an average time of 166.5 ± 14.8 h post-infection. Fluid administration may have temporarily blunted a rise in lactate, but the effect was short lived. Vasoactive medications resulted in short-lived improvements in mean arterial pressure. Blood transfusion and hydrocortisone did not appear to have a significant positive impact on the course of the disease. CONCLUSIONS: The model employed for this study is reflective of an intramuscular infection in humans (e.g., needle stick) and is highly lethal to NHPs. Using this model, we found that the animals developed progressive severe organ dysfunction and profound shock preceding death. While the overall impact of supportive care on the observed pathophysiology was limited, we did observe some time-dependent positive responses. Since this model is highly lethal, it does not reflect the full spectrum of human EVD. Our findings support the need for continued development of animal models that replicate the spectrum of human disease as well as ongoing development of anti-Ebola therapies to complement supportive care.

4.
Sci Rep ; 7(1): 1204, 2017 04 26.
Article En | MEDLINE | ID: mdl-28446775

Critical care needs have been rising in recent decades as populations age and comorbidities increase. Sepsis-related admissions to critical care contribute up to 50% of volume and septic shock carries a 35-54% fatality rate. Improvements in sepsis-related care and mortality would have a significant impact of a resource-intensive area of health care delivery. Unfortunately, research has been hampered by the lack of an animal model that replicates the complex care provided to humans in an intensive care unit (ICU). We developed a protocol to provide full ICU type supportive care to Rhesus macaques. This included mechanical ventilation, continuous sedation, fluid and electrolyte management and vasopressor support in response to Ebolavirus-induced septic shock. The animals accurately recapitulated human responses to a full range of ICU interventions (e.g. fluid resuscitation). This model can overcome current animal model limitations by accurately emulating the complexity of ICU care and thereby provide a platform for testing new interventions in critical care and sepsis without placing patients at risk.


Critical Care/methods , Critical Illness , Hemorrhagic Fever, Ebola/complications , Shock, Septic/therapy , Animals , Disease Models, Animal , Macaca mulatta
6.
Parasit Vectors ; 9(1): 322, 2016 06 06.
Article En | MEDLINE | ID: mdl-27267592

BACKGROUND: Fluralaner is a novel systemic ectoparasiticide for cats providing immediate and persistent flea- and tick-control after a single topical dose. Emodepsid and praziquantel are routinely used to control intestinal worm infections in cats. The safety of concurrent use of fluralaner and a commercially available emodepsid-praziquantel combination topical solution was investigated using topical administrations at the maximum recommended dose rates. FINDINGS: Few mild and transient clinical findings like erythema at the administration site and single incidences of salivation or vomiting were observed. All of which were consistent with the individual product leaflets. There were no findings suggesting an increased safety risk associated with the concurrent treatment of cats with fluralaner and emodepsid-praziquantel. CONCLUSIONS: Concurrent treatment with fluralaner, emodepsid and praziquantel is well tolerated in cats.


Anthelmintics/adverse effects , Cat Diseases/drug therapy , Depsipeptides/adverse effects , Insecticides/adverse effects , Isoxazoles/adverse effects , Praziquantel/adverse effects , Animals , Anthelmintics/administration & dosage , Anthelmintics/pharmacokinetics , Cat Diseases/parasitology , Cats , Depsipeptides/administration & dosage , Depsipeptides/pharmacokinetics , Dermatitis, Contact/veterinary , Drug Interactions , Drug Therapy, Combination , Ectoparasitic Infestations/drug therapy , Ectoparasitic Infestations/veterinary , Erythema/chemically induced , Erythema/veterinary , Female , Insecticides/administration & dosage , Insecticides/pharmacokinetics , Intestinal Diseases, Parasitic/drug therapy , Intestinal Diseases, Parasitic/veterinary , Isoxazoles/administration & dosage , Isoxazoles/pharmacokinetics , Male , Praziquantel/administration & dosage , Praziquantel/pharmacokinetics , Salivation/drug effects
7.
Parasit Vectors ; 9(1): 296, 2016 05 31.
Article En | MEDLINE | ID: mdl-27241240

BACKGROUND: Bravecto™ Chewable Tablets for Dogs, containing fluralaner as active ingredient, is an innovative treatment for flea and tick infestations that provides safe, rapid and long acting efficacy after a single oral administration in dogs. Topically applied fluralaner provides similar safe, rapid and long acting efficacy, both in dogs and in cats. The pharmacokinetic profile of fluralaner was evaluated in dogs and in cats following either topical or intravenous administration. METHODS: Twenty four dogs and 24 cats received three different topical doses, with the mid-dose based on the respective minimum recommended dose, and one intravenous dose. Plasma samples were collected for 112 days and fluralaner concentrations were quantified using a validated high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) method. Pharmacokinetic parameters were calculated using non-compartmental methods. RESULTS: In dogs, fluralaner was readily absorbed from the topical administration site into the skin, subjacent tissues and blood. Fluralaner plasma concentrations showed an apparent plateau between ~ day 7 and 63, with individual tmax seen within this time period. After the plasma plateau, concentrations declined slowly and were quantifiable for more than 12 weeks. In cats, fluralaner was readily systemically absorbed from the topical administration site, reaching maximum concentrations (Cmax) in plasma between 3 and 21 days post administration, after which concentrations declined slowly, and were also quantifiable for more than 12 weeks. Systemic exposure, as shown by Cmax and the area under the concentration versus time curve from time 0 to the last measurable concentration (AUC(0→t)) increased proportionally with dose in both species. Following intravenous administration fluralaner showed a relatively high apparent volume of distribution (Vz), a low plasma clearance (Cl), a long terminal half-life (t1/2) and a long mean residence time (MRT); thereby demonstrating a long persistence of fluralaner in both species. CONCLUSIONS: The pharmacokinetic characteristics of fluralaner explain its prolonged activity against fleas and ticks on both dogs and cats after a single topical administration.


Acaricides/pharmacokinetics , Cats/metabolism , Dogs/metabolism , Insecticides/pharmacokinetics , Isoxazoles/pharmacokinetics , Acaricides/blood , Administration, Intravenous , Administration, Topical , Animals , Arachnid Vectors/drug effects , Cat Diseases/parasitology , Cat Diseases/prevention & control , Cat Diseases/transmission , Dog Diseases/parasitology , Dog Diseases/prevention & control , Dog Diseases/transmission , Female , Flea Infestations/prevention & control , Flea Infestations/veterinary , Insect Vectors/drug effects , Insecticides/blood , Isoxazoles/blood , Male , Pharmaceutical Solutions , Siphonaptera/drug effects , Siphonaptera/parasitology , Tick Infestations/prevention & control , Tick Infestations/veterinary , Ticks/drug effects , Ticks/parasitology , Treatment Outcome
8.
Parasit Vectors ; 8: 508, 2015 Oct 06.
Article En | MEDLINE | ID: mdl-26438338

BACKGROUND: Fluralaner is a novel systemic ectoparasiticide for dogs providing immediate and persistent flea, tick and mite control after a single oral dose. Ivermectin has been used in dogs for heartworm prevention and at off label doses for mite and worm infestations. Ivermectin pharmacokinetics can be influenced by substances affecting the p-glycoprotein transporter, potentially increasing the risk of ivermectin neurotoxicity. This study investigated ivermectin blood plasma pharmacokinetics following concurrent administration with fluralaner. FINDINGS: Ten Beagle dogs each received a single oral administration of either 56 mg fluralaner (Bravecto™), 0.3 mg ivermectin or 56 mg fluralaner plus 0.3 mg ivermectin/kg body weight. Blood plasma samples were collected at multiple post-treatment time points over a 12-week period for fluralaner and ivermectin plasma concentration analysis. Ivermectin blood plasma concentration profile and pharmacokinetic parameters Cmax, tmax, AUC∞ and t½ were similar in dogs administered ivermectin only and in dogs administered ivermectin concurrently with fluralaner, and the same was true for fluralaner pharmacokinetic parameters. CONCLUSIONS: Concurrent administration of fluralaner and ivermectin does not alter the pharmacokinetics of either compound. Based on the plasma pharmacokinetic profile and the clinical observations, there is no evident interaction between fluralaner and ivermectin, and co-administration does not increase the risk of ivermectin associated neurotoxicity.


Dogs/blood , Insecticides/pharmacokinetics , Isoxazoles/pharmacokinetics , Ivermectin/pharmacokinetics , Administration, Oral , Animals , Area Under Curve , Drug Interactions , Half-Life , Insecticides/administration & dosage , Insecticides/blood , Isoxazoles/administration & dosage , Isoxazoles/blood , Ivermectin/administration & dosage , Ivermectin/blood
9.
Sci Rep ; 5: 8674, 2015 Mar 02.
Article En | MEDLINE | ID: mdl-25728468

Genomic selection (GS) approaches, in combination with reproductive technologies, are revolutionizing the design and implementation of breeding programs in livestock species, particularly in cattle. GS leverages genomic readouts to provide estimates of breeding value early in the life of animals. However, the capacity of these approaches for improving genetic gain in breeding programs is limited by generation interval, the average age of an animal when replacement progeny are born. Here, we present a cost-effective approach that combines GS with reproductive technologies to reduce generation interval by rapidly producing high genetic merit calves.


Breeding , Cattle/genetics , Selection, Genetic , Animals , Cell Line , Embryo Transfer , Female , Fetus
11.
Parasit Vectors ; 7: 481, 2014 Oct 15.
Article En | MEDLINE | ID: mdl-25315498

BACKGROUND: Fluralaner (Bravecto™; Merck/MSD Animal Health) is a novel systemic ectoparasiticide for dogs providing long-acting flea and tick control after a single oral dose. Milbemycin oxime and praziquantel are routinely used to control Dirofilaria immitis and intestinal worm infections in dogs. The safety of concurrent use of fluralaner and a commercially available milbemycin oxime plus praziquantel combination tablet, in particular with regard to gastrointestinal symptoms, was investigated using oral doses at or above the maximum recommended rates. FINDINGS: Some minor and transient clinical findings were observed during the study period; however, none of these was considered to be related to concurrent treatment with fluralaner and milbemycin oxime plus praziquantel, or to the use of either product alone. CONCLUSIONS: Concurrent treatment with fluralaner, milbemycin oxime and praziquantel is well tolerated in dogs.


Dog Diseases/chemically induced , Isoxazoles/adverse effects , Isoxazoles/pharmacokinetics , Macrolides/adverse effects , Macrolides/pharmacokinetics , Praziquantel/adverse effects , Praziquantel/pharmacokinetics , Animals , Anthelmintics/administration & dosage , Anthelmintics/adverse effects , Anthelmintics/pharmacokinetics , Dogs , Dose-Response Relationship, Drug , Drug Interactions , Drug Therapy, Combination , Female , Insecticides/administration & dosage , Insecticides/adverse effects , Insecticides/pharmacokinetics , Isoxazoles/administration & dosage , Macrolides/administration & dosage , Male , Praziquantel/administration & dosage
12.
Parasit Vectors ; 7: 86, 2014 Mar 06.
Article En | MEDLINE | ID: mdl-24602342

BACKGROUND: Fluralaner is a novel systemic ectoparasiticide for dogs providing long-acting flea- and tick-control after a single oral dose. This study investigated the safety of oral administration of fluralaner at 3 times the highest expected clinical dose to Multi Drug Resistance Protein 1 (MDR1(-/-)) gene defect Collies. METHODS: Sixteen Collies homozygous for the MDR1 deletion mutation were included in the study. Eight Collies received fluralaner chewable tablets once at a dose of 168 mg/kg; eight sham dosed Collies served as controls. All Collies were clinically observed until 28 days following treatment. RESULTS: No adverse events were observed subsequent to fluralaner treatment of MDR1(-/-) Collies at three times the highest expected clinical dose. CONCLUSIONS: Fluralaner chewable tablets are well tolerated in MDR1(-/-) Collies following oral administration.


ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Antiparasitic Agents/pharmacology , Dogs/genetics , Isoxazoles/pharmacology , Administration, Oral , Animals , Antiparasitic Agents/administration & dosage , Antiparasitic Agents/pharmacokinetics , Dose-Response Relationship, Drug , Female , Isoxazoles/administration & dosage , Isoxazoles/pharmacokinetics , Male , Safety , Sequence Deletion , Sex Factors , Single-Blind Method , Tablets , Time Factors
13.
Parasit Vectors ; 7: 85, 2014 Mar 07.
Article En | MEDLINE | ID: mdl-24606874

BACKGROUND: Fluralaner is a novel systemic insecticide and acaricide. The purpose of these studies was to investigate the pharmacokinetic properties of fluralaner in Beagle dogs following single oral or intravenous (i.v.) administration. METHODS: Following the oral administration of 12.5, 25 or 50 mg fluralaner/kg body weight (BW), formulated as chewable tablets or i.v. administration of 12.5 mg fluralaner/kg BW, formulated as i.v. solution to 24 Beagles, plasma samples were collected until 112 days after treatment. Plasma concentrations of fluralaner were measured using HPLC-MS/MS. Pharmacokinetic parameters were calculated by non-compartmental methods. RESULTS: After oral administration, maximum plasma concentrations (C(max)) were reached within 1 day on average. Fluralaner was quantifiable in plasma for up to 112 days after single oral and i.v. treatment. The apparent half-life of fluralaner was 12-15 days and the mean residence time was 15-20 days. The apparent volume of distribution of fluralaner was 3.1 L/kg, and clearance was 0.14 L/kg/day. CONCLUSIONS: Fluralaner is readily absorbed after single-dose oral administration, and has a long elimination half-life, long mean residence time, relatively high apparent volume of distribution, and low clearance. These pharmacokinetic characteristics help to explain the prolonged activity of fluralaner against fleas and ticks on dogs after a single oral dose.


Antiparasitic Agents/pharmacokinetics , Dogs/metabolism , Isoxazoles/pharmacokinetics , Acaricides/administration & dosage , Acaricides/blood , Acaricides/pharmacokinetics , Administration, Intravenous , Administration, Oral , Animals , Antiparasitic Agents/administration & dosage , Antiparasitic Agents/blood , Dose-Response Relationship, Drug , Female , Half-Life , Insecticides/administration & dosage , Insecticides/blood , Insecticides/pharmacokinetics , Isoxazoles/administration & dosage , Isoxazoles/blood , Male , Pharmaceutical Solutions , Safety , Tablets
14.
Parasit Vectors ; 7: 87, 2014 Mar 07.
Article En | MEDLINE | ID: mdl-24606886

BACKGROUND: Fluralaner is a novel systemic insecticide and acaricide that provides long acting efficacy in dogs after a single oral treatment. This study investigated the safety of oral administration of fluralaner in chewable tablets to dogs at the highest recommended treatment dose and at multiples of this dose. METHODS: Thirty-two (16 male and 16 female) healthy 8-week old Beagle dogs weighing 2.0 - 3.6 kg at first administration were included in the study. Fluralaner was administered on three occasions at 8-week intervals at doses of up to 56, 168, and 280 mg fluralaner/kg body weight, equivalent to 1, 3, and 5 times the highest recommended treatment dose of fluralaner; sham dosed dogs served as controls.During the study, all dogs were clinically observed, and their health was carefully monitored including body weight development, food consumption and measurement of hematology, coagulation, clinical chemistry (including measurement of levels of ACTH and C-reactive protein) and urinalysis. Following euthanasia of the dogs, complete gross post mortem examination, including organ weight determination, and histopathological examination of multiple tissues were conducted. RESULTS: There were no clinical findings related to fluralaner treatment. Statistically significant differences between the treated groups and the control group were observed for some clinical pathology parameters and organ weights; none of these findings were considered to be of clinical relevance. CONCLUSIONS: Oral administration of fluralaner at the highest recommended treatment dose (56 mg/kg) at 8-week intervals is well tolerated and has a safety margin of more than five in healthy dogs eight weeks of age or older and weighing at least 2 kg.


Antiparasitic Agents/pharmacology , Dogs/physiology , Isoxazoles/pharmacology , Acaricides/administration & dosage , Acaricides/pharmacokinetics , Acaricides/pharmacology , Administration, Oral , Animals , Antiparasitic Agents/administration & dosage , Antiparasitic Agents/pharmacokinetics , Body Weight/drug effects , C-Reactive Protein/analysis , Dose-Response Relationship, Drug , Eating/drug effects , Female , Hematology , Insecticides/administration & dosage , Insecticides/pharmacokinetics , Insecticides/pharmacology , Isoxazoles/administration & dosage , Isoxazoles/pharmacokinetics , Male , Organ Size/drug effects , Safety , Single-Blind Method , Tablets , Time Factors
15.
Parasit Vectors ; 7: 105, 2014 Mar 19.
Article En | MEDLINE | ID: mdl-24646450

BACKGROUND: Bravecto (fluralaner; MSD Animal Health) is a novel systemic ectoparasiticide for dogs providing long-acting flea- and tick-control after a single oral dose. Scalibor Protectorband (deltamethrin; MSD Animal Health) is a collar often used to reduce sandfly feeding for leishmaniasis prevention. This study investigated the safety of the concurrent use of Bravecto and Scalibor Protectorband at the recommended dosage regimens. FINDINGS: Throughout the study period of 24 weeks, there were no clinical findings related to the concurrent treatment with Bravecto in dogs fitted with Scalibor Protectorband at the recommended dosage regimen. CONCLUSIONS: Concurrent treatment with Bravecto in dogs fitted with Scalibor Protectorband is well tolerated.


Dog Diseases/chemically induced , Isoxazoles/adverse effects , Isoxazoles/therapeutic use , Nitriles/adverse effects , Nitriles/therapeutic use , Pyrethrins/adverse effects , Pyrethrins/therapeutic use , Animals , Dogs , Drug Interactions , Insect Control , Insecticides/administration & dosage , Insecticides/adverse effects , Insecticides/therapeutic use , Isoxazoles/administration & dosage , Nitriles/administration & dosage , Pyrethrins/administration & dosage , Tick Control , Tick Infestations/prevention & control , Tick Infestations/veterinary
16.
Parasit Vectors ; 7: 84, 2014 Mar 05.
Article En | MEDLINE | ID: mdl-24598049

BACKGROUND: Fluralaner is a novel systemic ectoparasiticide for dogs providing long-acting flea- and tick-control after a single oral dose. The pharmacokinetics of orally administered drugs may be influenced by feeding. This study investigated the influence of concurrent feeding on fluralaner pharmacokinetics. METHODS: Twelve fasted or fed beagles received a single oral administration of 25 mg fluralaner/kg body weight in a chewable tablet. Plasma samples were collected at multiple post-treatment time points for fluralaner concentration analysis. Clinical observations were performed on all dogs at regular intervals throughout the study. RESULTS: Fluralaner was readily absorbed in fasted and fed dogs administered at a dose of 25 mg/kg BW with a similar mean tmax for both groups. In fed dogs, AUC and C(max) were increased compared to fasted dogs by a factor of 2.5 and 2.1 respectively. The difference in AUC and C(max) between the fed and fasted groups was statistically significant. No adverse events were observed following oral fluralaner administration to fasted and fed dogs. CONCLUSIONS: Fluralaner is absorbed to a considerable extent in fasted and fed dogs. Administration of fluralaner chewable tablets with food significantly increases bioavailability.


Antiparasitic Agents/pharmacokinetics , Dogs/metabolism , Food-Drug Interactions , Isoxazoles/pharmacokinetics , Acaricides/administration & dosage , Acaricides/blood , Acaricides/pharmacokinetics , Administration, Oral , Animals , Antiparasitic Agents/administration & dosage , Antiparasitic Agents/blood , Area Under Curve , Body Weight , Dose-Response Relationship, Drug , Fasting , Female , Food , Gastrointestinal Absorption , Insecticides/administration & dosage , Insecticides/blood , Insecticides/pharmacokinetics , Isoxazoles/administration & dosage , Isoxazoles/blood , Male , Safety , Tablets
17.
Pediatr Ann ; 43(2): e50-5, 2014 Feb.
Article En | MEDLINE | ID: mdl-24512162

Hospitals have, for centuries, maintained a central position in the health care system, providing care for critically ill patients. Despite being a cornerstone of health care delivery, we are witnessing the beginning of a major transformation in their function. There are several forces driving this transformation, including health care costs, shortage of health care professionals, volume of people with chronic diseases, consumerism, health care reform, and hospital errors. The neonatal intensive care unit (NICU) at Utah Valley Regional Medical Center in Provo, Utah, began an aggressive redesign/quality improvement effort in 1990. It became obvious that our care processes were designed for health care deliverers and not for the families. An ongoing revamp of our care delivery processes was undertaken using significant input from a parent focus meeting, parental interviews, and development of a parent-to-parent support group. As a result of this work, it became obvious we needed a new model to truly empower parents. The idea of "NICU is Home" was born. We elected to make a mind shift, not to focus on what families think, but rather on how they think. Web cams and other video apparatus have been used in a number of NICUs across the country. We decided our equipment requirements would need to include high-resolution cameras, full high-definition video recording, autofocus, audio microphones, automatic noise reduction, and automatic low-light correction. Our conferencing software needed to accommodate multiple users and have multiple-picture capabilities, low band width, and inexpensive technology. It was recognized that a single video camera feed was insufficient to adequately capture the desired amount of information. Verbal communication between parents and their babies' principal care providers is critical. Parents loved the idea of expanding the remote NICU web cam of their baby to a two-way physician-parent communication bedside monitor. Doctors at Utah Valley Regional Medical Center now have a mobile desk using a WiFi computer/camera/audio to communicate with the family in real-time or leave a recording.


Infant Care/organization & administration , Intensive Care Units, Neonatal/organization & administration , Neonatology/organization & administration , Telemedicine/organization & administration , Focus Groups , Health Services Needs and Demand , Humans , Infant, Newborn , Intensive Care Units, Neonatal/trends , Parent-Child Relations , Physician-Patient Relations , Telemedicine/trends , United States
18.
BMC Genomics ; 13: 456, 2012 Sep 05.
Article En | MEDLINE | ID: mdl-22950759

BACKGROUND: To understand the genetic architecture of complex traits and bridge the genotype-phenotype gap, it is useful to study intermediate -omics data, e.g. the transcriptome. The present study introduces a method for simultaneous quantification of the contributions from single nucleotide polymorphisms (SNPs) and transcript abundances in explaining phenotypic variance, using Bayesian whole-omics models. Bayesian mixed models and variable selection models were used and, based on parameter samples from the model posterior distributions, explained variances were further partitioned at the level of chromosomes and genome segments. RESULTS: We analyzed three growth-related traits: Body Weight (BW), Feed Intake (FI), and Feed Efficiency (FE), in an F2 population of 440 mice. The genomic variation was covered by 1806 tag SNPs, and transcript abundances were available from 23,698 probes measured in the liver. Explained variances were computed for models using pedigree, SNPs, transcripts, and combinations of these. Comparison of these models showed that for BW, a large part of the variation explained by SNPs could be covered by the liver transcript abundances; this was less true for FI and FE. For BW, the main quantitative trait loci (QTLs) are found on chromosomes 1, 2, 9, 10, and 11, and the QTLs on 1, 9, and 10 appear to be expression Quantitative Trait Locus (eQTLs) affecting gene expression in the liver. Chromosome 9 is the case of an apparent eQTL, showing that genomic variance disappears, and that a tri-modal distribution of genomic values collapses, when gene expressions are added to the model. CONCLUSIONS: With increased availability of various -omics data, integrative approaches are promising tools for understanding the genetic architecture of complex traits. Partitioning of explained variances at the chromosome and genome-segment level clearly separated regulatory and structural genomic variation as the areas where SNP effects disappeared/remained after adding transcripts to the model. The models that include transcripts explained more phenotypic variance and were better at predicting phenotypes than a model using SNPs alone. The predictions from these Bayesian models are generally unbiased, validating the estimates of explained variances.


Genetic Variation , Genome/genetics , Models, Genetic , Phenotype , Transcriptome/genetics , Animals , Bayes Theorem , Body Weight/genetics , Crosses, Genetic , Eating/genetics , Genome/physiology , Mice , Polymorphism, Single Nucleotide/genetics , Quantitative Trait Loci/genetics , Transcriptome/physiology
19.
Genome Biol ; 10(5): R55, 2009.
Article En | MEDLINE | ID: mdl-19463160

BACKGROUND: Obesity is a particularly complex disease that at least partially involves genetic and environmental perturbations to gene-networks connecting the hypothalamus and several metabolic tissues, resulting in an energy imbalance at the systems level. RESULTS: To provide an inter-tissue view of obesity with respect to molecular states that are associated with physiological states, we developed a framework for constructing tissue-to-tissue coexpression networks between genes in the hypothalamus, liver or adipose tissue. These networks have a scale-free architecture and are strikingly independent of gene-gene coexpression networks that are constructed from more standard analyses of single tissues. This is the first systematic effort to study inter-tissue relationships and highlights genes in the hypothalamus that act as information relays in the control of peripheral tissues in obese mice. The subnetworks identified as specific to tissue-to-tissue interactions are enriched in genes that have obesity-relevant biological functions such as circadian rhythm, energy balance, stress response, or immune response. CONCLUSIONS: Tissue-to-tissue networks enable the identification of disease-specific genes that respond to changes induced by different tissues and they also provide unique details regarding candidate genes for obesity that are identified in genome-wide association studies. Identifying such genes from single tissue analyses would be difficult or impossible.


Adipose Tissue/metabolism , Gene Regulatory Networks , Liver/metabolism , Obesity/genetics , Animals , Humans , Mice , Obesity/physiopathology
20.
PLoS One ; 4(4): e5350, 2009.
Article En | MEDLINE | ID: mdl-19390634

The success of genome-wide association (GWA) studies for the detection of sequence variation affecting complex traits in human has spurred interest in the use of large-scale high-density single nucleotide polymorphism (SNP) genotyping for the identification of quantitative trait loci (QTL) and for marker-assisted selection in model and agricultural species. A cost-effective and efficient approach for the development of a custom genotyping assay interrogating 54,001 SNP loci to support GWA applications in cattle is described. A novel algorithm for achieving a compressed inter-marker interval distribution proved remarkably successful, with median interval of 37 kb and maximum predicted gap of <350 kb. The assay was tested on a panel of 576 animals from 21 cattle breeds and six outgroup species and revealed that from 39,765 to 46,492 SNP are polymorphic within individual breeds (average minor allele frequency (MAF) ranging from 0.24 to 0.27). The assay also identified 79 putative copy number variants in cattle. Utility for GWA was demonstrated by localizing known variation for coat color and the presence/absence of horns to their correct genomic locations. The combination of SNP selection and the novel spacing algorithm allows an efficient approach for the development of high-density genotyping platforms in species having full or even moderate quality draft sequence. Aspects of the approach can be exploited in species which lack an available genome sequence. The BovineSNP50 assay described here is commercially available from Illumina and provides a robust platform for mapping disease genes and QTL in cattle.


Cattle/genetics , Computational Biology/methods , Genotype , Polymorphism, Single Nucleotide/genetics , Animals , Chromosomes, Artificial, Bacterial/genetics , Gene Frequency , Genome , Genome-Wide Association Study , Quantitative Trait Loci
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