3,593 research outputs found
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Correlation of thyroid hormone measurements with thyroid stimulating hormone stimulation test results in radioiodine-treated cats.
BACKGROUND: Iatrogenic hypothyroidism can develop after radioiodine-I131 (RAI) treatment of hyperthyroid cats and can be diagnosed using the thyroid stimulating hormone (TSH) stimulation test. OBJECTIVES: To assess the effect of noncritical illness on TSH stimulation test results in euthyroid and RAI-treated cats. To assess the correlation of low total-thyroxine (tT4), low free-thyroxine (fT4), and high TSH concentrations with TSH stimulation test results. ANIMALS: Thirty-three euthyroid adult cats and 118 client-owned cats previously treated with RAI. METHODS: Total-thyroxine, fT4, and TSH were measured, and a TSH stimulation test was performed in all cats. Euthyroid control cats were divided into apparently healthy and noncritical illness groups. RAI-treated cats were divided into RAI-hypothyroid (after-stimulation tT4 ≤ 1.5 μg/dL), RAI-euthyroid (after-stimulation tT4 ≥ 2.3 μg/dL OR after-stimulation tT4 1.5-2.3 μg/dL and before : after tT4 ratio > 1.5), and RAI-equivocal (after stimulation tT4 1.5-2.3 μg/dL and tT4 ratio < 1.5) groups. RESULTS: Noncritical illness did not significantly affect the tT4 following TSH stimulation in euthyroid (P = .38) or RAI-treated cats (P = .54). There were 21 cats in the RAI-equivocal group. Twenty-two (85%) RAI-hypothyroid cats (n = 26) and 10/71 (14%) of RAI-euthyroid cats had high TSH (≥0.3 ng/mL). Twenty-three (88%) RAI-hypothyroid cats had low fT4 (<0.70 ng/dL). Of the 5 (7%) RAI-euthyroid cats with low fT4, only one also had high TSH. Only 5/26 (19%) RAI-hypothyroid cats had tT4 below the laboratory reference interval (<0.78 μg/dL). CONCLUSIONS AND CLINICAL RELEVANCE: The veterinary-specific chemiluminescent fT4 immunoassay and canine-specific TSH immunoassay can be used to aid in the diagnosis of iatrogenic hypothyroidism in cats
Does Fungal Endophyte Infection Improve Tall Fescue’s Growth Response to Fire and Water Limitation?
Invasive species may owe some of their success in competing and co-existing with native species to microbial symbioses they are capable of forming. Tall fescue is a cool-season, non-native, invasive grass capable of co-existing with native warm-season grasses in North American grasslands that frequently experience fire, drought, and cold winters, conditions to which the native species should be better-adapted than tall fescue. We hypothesized that tall fescue’s ability to form a symbiosis with Neotyphodium coenophialum, an aboveground fungal endophyte, may enhance its environmental stress tolerance and persistence in these environments. We used a greenhouse experiment to examine the effects of endophyte infection (E+ vs. E−), prescribed fire (1 burn vs. 2 burn vs. unburned control), and watering regime (dry vs. wet) on tall fescue growth. We assessed treatment effects for growth rates and the following response variables: total tiller length, number of tillers recruited during the experiment, number of reproductive tillers, tiller biomass, root biomass, and total biomass. Water regime significantly affected all response variables, with less growth and lower growth rates observed under the dry water regime compared to the wet. The burn treatments significantly affected total tiller length, number of reproductive tillers, total tiller biomass, and total biomass, but treatment differences were not consistent across parameters. Overall, fire seemed to enhance growth. Endophyte status significantly affected total tiller length and tiller biomass, but the effect was opposite what we predicted (E−\u3eE+). The results from our experiment indicated that tall fescue was relatively tolerant of fire, even when combined with dry conditions, and that the fungal endophyte symbiosis was not important in governing this ecological ability. The persistence of tall fescue in native grassland ecosystems may be linked to other endophyte-conferred abilities not measured here (e.g., herbivory release) or may not be related to this plant-microbial symbiosis
Endoscopic Assessment and Prediction of Prostate Urethral Disintegration After Histotripsy Treatment in a Canine Model*
Abstract Background and Purpose: Histotripsy is a nonthermal focused ultrasound technology that uses acoustic cavitation to homogenize tissue. Previous research has demonstrated that the prostatic urethra is more resistant to histotripsy effects than prostate parenchyma, a finding that may complicate the creation of transurethral resection of the prostate-like treatment cavities. The purpose of this study was to characterize the endoscopic appearance of the prostatic urethra during and after histotripsy treatment and to identify features that are predictive of urethral disintegration. Materials and Methods: Thirty-five histotripsy treatments were delivered in a transverse plane traversing the prostatic urethra in 17 canine subjects (1?3/prostate ≥1?cm apart). Real-time endoscopy was performed in the first four subjects to characterize development of acute urethral treatment effect (UTE). Serial postprocedure endoscopy was performed in all subjects to assess subsequent evolution of UTE. Results: Endoscopy during histotripsy was feasible with observation of intraurethral cavitation, allowing characterization of the real-time progression of UTE from normal to frank urethral disintegration. While acute urethral fragmentation occurred in 3/35 (8.6%) treatments, frank urethral disintegration developed in 24/35 (68.5%) within 14 days of treatment. Treating until the appearance of hemostatic pale gray shaggy urothelium was the best predictor of achieving urethral fragmentation within 14 days of treatment with positive and negative predictive values of 0.91 and 0.89, respectively. Conclusion: Endoscopic assessment of the urethra may be a useful adjunct to prostatic histotripsy to help guide therapy to ensure urethral disintegration, allowing drainage of the homogenized adenoma and effective tissue debulking.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98446/1/end%2E2011%2E0349.pd
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A Global Climatology of Extratropical Transition. Part I: Characteristics across Basins
The authors present a global climatology of tropical cyclones (TCs) that undergo extratropical transition (ET). ET is objectively defined based on a TC’s trajectory through the cyclone phase space (CPS), which is calculated using storm tracks from 1979–2017 best track data and geopotential height fields from reanalysis datasets. Two reanalyses are used and compared for this purpose, the Japanese 55-yr Reanalysis and the ECMWF interim reanalysis. The results are used to study the seasonal and geographical distributions of storms undergoing ET and interbasin differences in the statistics of ET occurrence. About 50% of all TCs in the North Atlantic and the western North Pacific undergo ET. In the Southern Hemisphere, ET fractions range from about 20% in the south Indian Ocean and the Australian region to 45% in the South Pacific. In the majority of ETs, TCs become thermally asymmetric before forming a cold core. However, a substantial fraction of TCs take the reverse pathway, developing a cold core before becoming thermally asymmetric. This pathway is most common in the eastern North Pacific and the North Atlantic. Different ET pathways can be linked to different geographical trajectories and environmental settings. In ETs over warmer sea surface temperatures, TCs tend to lose their thermal symmetry while still maintaining a warm core. Landfalls by TCs undergoing ET occur 3–4 times per year in the North Atlantic and 7–10 times per year in the western North Pacific, while coastal regions in the Australian region are affected once every 1–2 years
Characterisation of the Upper Respiratory Tract Virome of Feedlot Cattle and its Association with Bovine Respiratory Disease
Bovine respiratory disease (BRD) is a major health problem within the global cattle industry. This disease has a complex aetiology, with viruses playing an integral role. In this study, metagenomics was used to sequence viral nucleic acids in the nasal swabs of BRD affected cattle. Viruses detected included those well known for their association with BRD in Australia (bovine viral diarrhea virus 1), as well as viruses known to be present but not fully characterised (bovine coronavirus) and viruses that have not been reported in BRD affect cattle in Australia (bovine rhinitis, bovine influenza D, and bovine nidovirus). Nasal swabs from a case control study were subsequently tested for 10 viruses and the presence of at least one virus was found to be significantly associated with BRD. Some of the more recently detected viruses had inconsistent association with BRD. Full genome sequences for bovine coronavirus, a virus increasingly associated with BRD, and bovine nidovirus were complete. Both viruses belong to the Coronaviridae family, which are frequently associated with disease in mammals. This study has provided greater insights into the viral pathogens associated with BRD and highlighted the need for further studies to elucidate more precisely the roles viruses play in BRD
Characterisation of the Upper Respiratory Tract Virome of Feedlot Cattle and its Association with Bovine Respiratory Disease
Bovine respiratory disease (BRD) is a major health problem within the global cattle industry. This disease has a complex aetiology, with viruses playing an integral role. In this study, metagenomics was used to sequence viral nucleic acids in the nasal swabs of BRD affected cattle. Viruses detected included those well known for their association with BRD in Australia (bovine viral diarrhea virus 1), as well as viruses known to be present but not fully characterised (bovine coronavirus) and viruses that have not been reported in BRD affect cattle in Australia (bovine rhinitis, bovine influenza D, and bovine nidovirus). Nasal swabs from a case control study were subsequently tested for 10 viruses and the presence of at least one virus was found to be significantly associated with BRD. Some of the more recently detected viruses had inconsistent association with BRD. Full genome sequences for bovine coronavirus, a virus increasingly associated with BRD, and bovine nidovirus were complete. Both viruses belong to the Coronaviridae family, which are frequently associated with disease in mammals. This study has provided greater insights into the viral pathogens associated with BRD and highlighted the need for further studies to elucidate more precisely the roles viruses play in BRD
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A Global Climatology of Extratropical Transition. Part II: Statistical Performance of the Cyclone Phase Space
This study analyzes the differences between an objective, automated identification of tropical cyclones (TCs) that undergo extratropical transition (ET), and the designation of ET determined subjectively by human forecasters in best track data in all basins globally. The objective identification of ET is based on the cyclone phase space (CPS), calculated from the Japanese 55-yr Reanalysis (JRA-55) or the ECMWF interim reanalysis (ERA-Interim). The resulting classification into ET storms and non-ET storms underlies the global climatology of ET presented in Part I of this study. Here, the authors investigate how well the CPS classifications agree with those in the best track records calculated from JRA-55 or from ERA-Interim data. According to F1 scores and Matthews correlation coefficients (MCCs), the classification of ET storms in the CPS agrees best with the best track classification in the western North Pacific (MCC > 0.7) and the North Atlantic (MCC > 0.5). In other basins, the correlation between the CPS classification and the best track classification is only slightly higher than that of a random classification. The JRA-55 classification achieves higher performance scores than does the ERA-Interim classification, and the differences are statistically significant in all basins. The lower performance of ERA-Interim is mainly due to a higher false alarm rate, particularly in the eastern North Pacific. Overall, the results show that while the CPS-based classifications are good enough to be useful for many purposes, there is almost certainly room for improvement—in the representation of the storms in reanalyses, in our objective metrics of ET, and in our scientific understanding of the ET process
Histotripsy Effects on the Bladder Trigone: Functional and Histologic Consequences in the Canine Model
Background: Histotripsy is an extracorporeal therapeutic ultrasound (US) technology, where high-amplitude acoustic energy is applied to targeted tissue. Previous research has demonstrated the feasibility, safety, and effectiveness of histotripsy tissue homogenization and debulking of the prostate in the canine model. Before translating this technology for human use, it is prudent to examine the susceptibility of critical periprostatic structures to cavitation injury in the event of histotripsy mistargeting. In this study, we sought to characterize the tissue effects and biologic response of directly treating the bladder trigone with histotripsy. Materials and Methods: In eight anesthetized canines, 750,000 histotripsy pulses were applied uniformly across a 2?1.5-cm area encompassing the bladder trigone and ureteral orifices. Prostate and bladder trigone were harvested immediately after treatment (2 subjects) or at 14 days (6 subjects). Flexible cystourethroscopy, US imaging, and creatinine levels were obtained at intervals until harvest, 14 days after treatment. In one control subject, harvested at 2 days, the same treatment algorithm was applied to the prostate. Results: Transrectal US imaging revealed a cavitation bubble cloud on the surface of the bladder trigone and progressive development of tissue edema during treatment. Flexible cystourethroscopy immediately after treatment confirmed edema and erythema of the trigone. In the six subjects survived 2 weeks after treatment, one incidence of transient, self-limited ureteral obstruction was noted based on hydronephrosis and creatinine levels. At harvest, ureteral orifices were confirmed patent by passage of a guide wire. Histologic evaluation revealed hemorrhage acutely with mild localized fibrosis at 14 days. Conclusions: In this study, designed along the lines of a worst-case, destructive testing scenario, direct targeting of the bladder trigone with supratherapeutic histotripsy failed to induce significant tissue damage or clinical complication. These results are reassuring and will guide treatment strategy in upcoming human clinical trials of histotripsy treatment for benign prostatic hyperplasia.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140374/1/end.2013.0234.pd
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