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1.
J Astronaut Sci ; 71(4): 33, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39021366

RESUMEN

This paper documents the results from the highly successful Lunar flashlight Optical Navigation Experiment with a Star tracker (LONEStar). Launched in December 2022, Lunar Flashlight (LF) was a NASA-funded technology demonstration mission. After a propulsion system anomaly prevented capture in lunar orbit, LF was ejected from the Earth-Moon system and into heliocentric space. NASA subsequently transferred ownership of LF to Georgia Tech to conduct an unfunded extended mission to demonstrate further advanced technology objectives, including LONEStar. From August to December 2023, the LONEStar team performed on-orbit calibration of the optical instrument and a number of different OPNAV experiments. This campaign included the processing of nearly 400 images of star fields, Earth and Moon, and four other planets (Mercury, Mars, Jupiter, and Saturn). LONEStar provided the first on-orbit demonstrations of heliocentric navigation using only optical observations of planets. Of special note is the successful in-flight demonstration of (1) instantaneous triangulation with simultaneous sightings of two planets with the LOST algorithm and (2) dynamic triangulation with sequential sightings of multiple planets.

2.
Int J Pharm ; 662: 124511, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39067548

RESUMEN

Monoclonal antibodies (mAbs) represent a promising modality for the prevention and treatment of viral infections. For infections that initiate from the respiratory tract, direct administration of specific neutralizing mAbs into lungs has advantages over systemic injection of the same mAbs. Herein, using AUG-3387, a human-derived mAb with high affinity to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its various variants, as a model mAb, we formulated the mAb into dry powders by thin-film freeze-drying, confirmed that the AUG-3387 mAb reconstituted from the dry powders retained their integrity, high affinity to the SARS-CoV-2 spike protein receptor binding domain (RBD), as well as ability to neutralize RBD-expressing pseudoviruses. Finally, we showed that one of the AUG-3387 mAb dry powders had desirable aerosol properties for pulmonary delivery into the lung. We concluded that thin-film freeze-drying represents a viable method to prepare inhalable powders of virus-neutralizing mAbs for pulmonary delivery into the lung.


Asunto(s)
Anticuerpos Monoclonales , Liofilización , Polvos , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/administración & dosificación , Administración por Inhalación , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/administración & dosificación , Humanos , Inhaladores de Polvo Seco , Aerosoles , Pulmón/metabolismo , COVID-19/prevención & control , Tratamiento Farmacológico de COVID-19
3.
Am J Trop Med Hyg ; 111(3): 671-675, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-38981507

RESUMEN

Patients with ciguatera poisoning commonly present with gastrointestinal and neurologic symptoms, but its cardiotoxicity has been largely unrecognized. This systematic review is the first to summarize the evidence regarding clinical characteristics of cardiotoxicity from ciguatera poisoning to provide the illness script and pertinent knowledge for clinicians. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement, we searched MEDLINE and EMBASE for all peer-reviewed articles using keywords including "ciguatera" and "cardiotoxicity" from their inception to January 2024. We included 20 articles, including 148 cases, in this systematic review. Among the included cases, the median age was 54 years with male predominance (62.2%). Based on the WHO designation, 68.5% were reported from the Western Pacific Region. Common symptoms included hypotension (75.0%) and bradycardia (67.6%), and chest pain or syncope were less commonly reported (2.7% and 1.4%, respectively). Sinus bradycardia was the most common electrocardiogram abnormality (35.9%), followed by atrioventricular blocks (15.4%). Symptomatic treatments such as atropine, dopamine, and epinephrine were commonly used, and only 4.1% required intensive care unit admission. None expired due to cardiotoxicity from ciguatera. This review summarizes the current evidence and the characteristics of cardiotoxicity from ciguatera. Although ciguatera cardiotoxicity is currently underrecognized, increased awareness of the condition in clinicians is crucial because the clinical outcomes of the patients could be benign as long as it is identified and intervened early.


Asunto(s)
Cardiotoxicidad , Intoxicación por Ciguatera , Humanos , Cardiotoxicidad/epidemiología , Cardiotoxicidad/etiología , Intoxicación por Ciguatera/epidemiología , Masculino , Persona de Mediana Edad , Femenino , Adulto , Anciano
4.
Cureus ; 16(3): e56362, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38633923

RESUMEN

Iatrogenic venous compression syndrome is defined by extrinsic vein compression due to medical hardware, particularly relevant after joint replacement surgeries. Inserting medical hardware can lead to immediate risks such as deep vein thrombosis and pulmonary embolisms due to local tissue inflammation. The long-term issues include venous insufficiency due to chronic vessel irritation, subsequently causing intimal proliferation and thickening. Despite the existing knowledge of venous compression syndromes, iatrogenic cases are severely underreported. Here, we present a unique case of bilateral common femoral vein compression in a patient with May-Thurner syndrome and prior bilateral hip arthroplasty. An 85-year-old man with a history of venous insufficiency and bilateral hip arthroplasty for osteoarthritis presented with bilateral leg edema. Unsuccessful sclerotherapy and radiofrequency ablation led to a referral to a vascular specialist for venous duplex scans, venograms, and intravascular ultrasound. May-Thurner syndrome was revealed in the left common iliac vein, prompting the deployment of an 18 mm × 16 mm stent. Subsequently, during a venogram, what initially appeared to be a vasospasm in the left common femoral vein was diagnosed as extrinsic iatrogenic venous compression due to acetabular hip screws. This was found after two IV injections of 400 mg nitrogen and one balloon angioplasty could not resolve the compression. After advancement over a 0.35" microwire and accurate positioning over the center of the left common femoral vein lesion, a 16 mm × 90 mm stent was deployed. The venogram and intravascular ultrasound also showed a similar compression in the right common femoral vein. Another 400 mg IV nitrogen did not expand the lesion, so it was concluded that there was similarly an iatrogenic venous compression of the right common femoral vein, also due to acetabular hip screws in the right femur. A follow-up was scheduled a couple of weeks later to address the issue in the right common femoral vein. The underreported issue of iatrogenic venous compression following joint replacements highlights the need for better recognition and management of vascular complications due to inflammation and intimal proliferation. This is especially the case in high-risk patients, such as those with May-Thurner syndrome.

5.
J Feline Med Surg ; 25(7): 1098612X231185680, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37470518

RESUMEN

OBJECTIVES: Thrombocytosis is an uncommon hematologic abnormality that is associated with various physiologic, metabolic, inflammatory and neoplastic conditions in people and dogs. Thrombocytosis is not a well-described abnormality in cats. The objective of this study was to classify thrombocytosis in cats based on underlying disease processes and severity, and to compare this with a control population of cats. METHODS: A retrospective study was conducted by reviewing the medical records of cats with increased (>600 × 103/µl; thrombocytosis group) and normal (200-600 × 103/µl; 2:1 age-matched control group) platelet counts between 2011 and 2018. Platelet counts were estimated based on blood smear assessment in all cats. Cats were classified by the severity (mild, moderate or marked) of thrombocytosis. Diagnoses were recorded for all cases, and were classified broadly into either neoplasia, endocrine or inflammatory disease. RESULTS: In total, 158 cats were identified with thrombocytosis, with 315 cats in the control group. Non-neoplastic inflammatory disease was the most common diagnosis in both groups (54.4% in cats with thrombocytosis and 56.2% in controls; P = 0.77); however, gastrointestinal diseases were more common in cats with thrombocytosis (75.6%) when compared with controls (34.5%; P <0.0001). Neoplasia was diagnosed more frequently in cats with thrombocytosis (44.3%) compared with the control group (25.4%; P <0.0001). Round cell tumor was the most common neoplasia diagnosis in both groups, but gastrointestinal and multicentric lymphoma were diagnosed more frequently in cats with thrombocytosis compared with control cats. No association between the severity of thrombocytosis and etiology was identified. CONCLUSIONS AND RELEVANCE: Thrombocytosis in cats is more commonly associated with gastrointestinal, hepatobiliary or immune-mediated diseases when compared with a control population. Neoplasia, especially multicentric and gastrointestinal lymphoma, was more commonly diagnosed in cats with thrombocytosis when compared with control cats.


Asunto(s)
Enfermedades de los Gatos , Enfermedades de los Perros , Sarcoma , Trombocitosis , Gatos , Animales , Perros , Estudios Retrospectivos , Trombocitosis/epidemiología , Trombocitosis/veterinaria , Trombocitosis/complicaciones , Recuento de Plaquetas/veterinaria , Sarcoma/veterinaria , Enfermedades de los Gatos/diagnóstico , Enfermedades de los Gatos/epidemiología , Enfermedades de los Gatos/etiología
6.
Neurol Int ; 14(4): 997-1006, 2022 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-36548184

RESUMEN

BACKGROUND: Dopamine Responsive Dystonia (DRD) and Juvenile Parkinsonism (JP) are two diseases commonly presenting with parkinsonian symptoms in young patients. Current clinical guidelines offer a diagnostic approach based on molecular analysis. However, developing countries have limitations in terms of accessibility to these tests. We aimed to assess the utility of imaging equipment, usually more available worldwide, to help diagnose and improve patients' quality of life with these diseases. METHODS: We performed a systematic literature review in English using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and meta-analysis of observational studies in epidemiology (MOOSE) protocols. We only used human clinical trials about dopamine responsive dystonia and juvenile parkinsonism patients in which a fluorodopa (FD) positron emission tomography (PET) scan was performed to identify its use in these diseases. RESULTS: We included six studies that fulfilled our criteria. We found a clear pattern of decreased uptake in the putamen and caudate nucleus in JP cases. At the same time, the results in DRD were comparable to normal subjects, with only a slightly decreased marker uptake in the previously mentioned regions by the FD PET scan. CONCLUSIONS: We found a distinctive pattern for each of these diseases. Identifying these findings with FD PET scans can shorten the delay in making a definitive diagnosis when genetic testing is unavailable, a common scenario in developing countries.

7.
Vet J ; 289: 105911, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36202308

RESUMEN

Prognostic factors for dogs with diffuse large B-cell lymphoma (DLBCL) are poorly characterized. Prior reports suggest that dogs with a systemic inflammatory response at the time of lymphoma diagnosis experience inferior survival times. However, no specific biomarkers of inflammation have been identified as prognostic indicators in dogs with DLBCL. Baseline C-reactive protein (CRP) concentrations were measured in banked sera from 91 dogs with chemotherapy-treated DLBCL using a commercially available laboratory assay. Associations between baseline serum CRP concentrations and other variables of potential prognostic significance with progression-free survival (PFS) were tested using Cox proportional hazards modeling. In the final multivariable model, only a complete (rather than partial) remission to chemotherapy (Hazard ratio [HR] 0.02; 95% confidence intervals [CI] 0.01-0.07; P < 0.001) and serum CRP concentration > 1.0 mg/dL (HR, 1.73; 95% CI, 1.02-2.92; P = 0.042) were significantly associated with PFS. The median PFS for dogs with CRP concentration ≤ 1.0 mg/dL (within the test reference interval) was 315 days, while that for dogs with CRP concentration > 1.0 mg/dL was 232 days (P = 0.06). These results suggest that baseline serum CRP concentration is independently associated with progression-free survival in dogs with DLBCL, making it a potentially useful prognostic biomarker for dogs with this cancer.

8.
J Orthop Sports Phys Ther ; 52(11): 750-768, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36070427

RESUMEN

OBJECTIVE: To determine the effects of nonsurgical treatments on pain and function in people with patellofemoral pain (PFP). DESIGN: Systematic review with meta-analysis. LITERATURE SEARCH: We searched MEDLINE, Web of Science, and Scopus databases from their inception until May 2022 for interventional randomized controlled trials (RCTs) in people with PFP. STUDY SELECTION CRITERIA: We included RCTs that were scored ≥7 on the PEDro scale. DATA SYNTHESIS: We extracted homogenous pain and function data at short- (≤3 months), medium- (>3 to ≤12 months) and long-term (>12 months) follow-up. Interventions demonstrated primary efficacy if outcomes were superior to sham, placebo, or wait-and-see control. Interventions demonstrated secondary efficacy if outcomes were superior to an intervention with primary efficacy. RESULTS: We included 65 RCTs. Four interventions demonstrated short-term primary efficacy: knee-targeted exercise therapy for pain (standardized mean difference [SMD], 1.16; 95% CI: 0.66, 1.66) and function (SMD, 1.19; 95% CI: 0.51, 1.88), combined interventions for pain (SMD, 0.79; 95% CI: 0.26, 1.29) and function (SMD, 0.98; 95% CI: 0.47, 1.49), foot orthoses for global rating of change (OR = 4.31; 95% CI: 1.48, 12.56), and lower-quadrant manual therapy for function (SMD, 2.30; 95% CI: 1.60, 3.00). Two interventions demonstrated short-term secondary efficacy compared to knee-targeted exercise therapy: hip-and-knee-targeted exercise therapy for pain (SMD, 1.02; 95% CI: 0.58, 1.46) and function (SMD, 1.03; 95% CI: 0.61, 1.45), and knee-targeted exercise therapy and perineural dextrose injection for pain (SMD, 1.34; 95% CI: 0.72, 1.95) and function (SMD, 1.21; 95% CI: 0.60, 1.82). CONCLUSIONS: Six interventions had positive effects at 3 months for people with PFP, with no intervention adequately tested beyond this time point. J Orthop Sports Phys Ther 2022;52(11):750-768. Epub: 8 September 2022. doi:10.2519/jospt.2022.11359.


Asunto(s)
Manipulaciones Musculoesqueléticas , Síndrome de Dolor Patelofemoral , Humanos , Síndrome de Dolor Patelofemoral/terapia , Terapia por Ejercicio , Articulación de la Rodilla , Dolor
9.
J Geophys Res Planets ; 127(6): e2021JE007096, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35865672

RESUMEN

Gale crater, the field site for NASA's Mars Science Laboratory Curiosity rover, contains a diverse and extensive record of aeolian deposition and erosion. This study focuses on a series of regularly spaced, curvilinear, and sometimes branching bedrock ridges that occur within the Glen Torridon region on the lower northwest flank of Aeolis Mons, the central mound within Gale crater. During Curiosity's exploration of Glen Torridon between sols ∼2300-3080, the rover drove through this field of ridges, providing the opportunity for in situ observation of these features. This study uses orbiter and rover data to characterize ridge morphology, spatial distribution, compositional and material properties, and association with other aeolian features in the area. Based on these observations, we find that the Glen Torridon ridges are consistent with an origin as wind-eroded bedrock ridges, carved during the exhumation of Mount Sharp. Erosional features like the Glen Torridon ridges observed elsewhere on Mars, termed periodic bedrock ridges (PBRs), have been interpreted to form transverse to the dominant wind direction. The size and morphology of the Glen Torridon PBRs are consistent with transverse formative winds, but the orientation of nearby aeolian bedforms and bedrock erosional features raise the possibility of PBR formation by a net northeasterly wind regime. Although several formation models for the Glen Torridon PBRs are still under consideration, and questions persist about the nature of PBR-forming paleowinds, the presence of PBRs at this site provides important constraints on the depositional and erosional history of Gale crater.

10.
JMIR Diabetes ; 7(2): e36181, 2022 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-35486904

RESUMEN

BACKGROUND: Lockdown restrictions reduce COVID-19 community transmission; however, they may pose challenges for noncommunicable disease management. A 112-day hard lockdown in Victoria, Australia (commencing March 23, 2020) coincided with an intervention trial of reducing and breaking up sitting time in desk workers with type 2 diabetes who were using a provided consumer-grade activity tracker (Fitbit). OBJECTIVE: This study aims to compare continuously recorded activity levels preceding and during COVID-19 lockdown restrictions among working adults with type 2 diabetes participating in a sitting less and moving more intervention. METHODS: A total of 11 participants (n=8 male; mean age 52.8, SD 5 years) in Melbourne, Australia had Fitbit activity tracked before (mean 122.7, SD 47.9 days) and during (mean 99.7, SD 62.5 days) citywide COVID-19 lockdown restrictions. Regression models compared device (Fitbit Inspire HR)-derived activity (steps; metabolic equivalent tasks [METs]; mean time in sedentary, lightly, fairly, and very active minutes; and usual bout durations) during restrictions to prerestrictions. Changes in activity were statistically significant when estimates (Δ%) did not intercept zero. RESULTS: Overall, there was a decrease in mean steps (-1584 steps/day; Δ% -9%, 95% CI -11% to -7%); METs (-83 METs/day; Δ% -5%, 95% CI -6% to -5%); and lightly active (Δ% -4%, 95% CI -8% to -1%), fairly active (Δ% -8%, 95% CI -21% to -15%), and very active (Δ% -8%, 95% CI -11% to -5%) intensity minutes per day, and increases in mean sedentary minutes per day (51 mins/day; Δ% 3%, 95% CI 1%-6%). Only very active (+5.1 mins) and sedentary (+4.3 mins) bout durations changed significantly. CONCLUSIONS: In a convenience sample of adults with type 2 diabetes, COVID-19 lockdown restrictions were associated with decreases in overall activity levels and increases in very active and sedentary bout durations. A Fitbit monitor provided meaningful continuous long-term data in this context. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12618001159246; https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12618001159246.

12.
Materials (Basel) ; 15(2)2022 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-35057337

RESUMEN

Recycled Excavation Materials (REM) are becoming viable alternative construction resources due to their economic benefits. However, REM may be composed of weak rocks, e.g., phyllites, limiting the use in a base layer. The present paper attempts to further the knowledge of the mechanical performance of REM by performing Repeated Load Triaxial Tests (RLTT). REM are mixed with Recycled Phyllite Materials (RPM) in systematic blends of 0%, 25%, 50%, and 100%. The batches' resilient modulus (MR) and permanent deformation (PD) characteristics were assessed to establish the maximum RPM allowed into REM while maintaining the required performance. Hicks and Monismith's and Uzan's models were used to characterize the stiffness behavior. A wide variation in the stiffness between the two materials was observed. Batches comprised of 0% RPM-100% REM and 25% RPM-75% REM showed high stiffness performance. The Coulomb model assessed the PD behavior, and the results showed a similar response for all batches. Unlike the stiffness, blended mixtures did not show sensitivity to increased RPM content in the PD. This study may help end-users to understand the performance of REM given the documented threshold on the allowable quantity of RPM in REM.

13.
Trials ; 22(1): 777, 2021 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-34742328

RESUMEN

BACKGROUND: Strong evidence supports the proximal combined with quadriceps strengthening for patellofemoral pain (PFP) rehabilitation. However, most reported rehabilitation programs do not follow specific exercise prescription recommendations or do not provide adequate details for replication in clinical practice. Furthermore, people with PFP have power deficits in hip and knee muscles and it remains unknown whether the addition of power exercises would result in superior or more consistent outcomes. Therefore, this study is designed to verify whether the benefits of a rehabilitation program addressing proximal and knee muscles comprising power and strength exercises are greater than those of a program consisting of strength exercises only. METHOD: This study will be a randomized controlled trial that will be conducted at university facilities. A minimum of 74 people with PFP between the ages of 18 and 45 years will be included. The experimental group will engage in a 12-week resistance training program focusing on proximal and knee muscles using power and strength exercises. The control group will engage in a 12-week resistance training program focusing on proximal and knee muscles using strength exercises only. Primary outcomes will be pain intensity and physical function; and secondary outcomes will be kinesiophobia, self-reported improvement, quality of life, peak hip and knee torque, and hip and knee rate of force development. The primary outcomes will be evaluated at baseline, and after 6 weeks, 12 weeks, 3 months, 6 months, and 1 year. The secondary outcomes will be evaluated at baseline and immediately after the interventions. Therapists and participants will not be blinded to group allocation. DISCUSSION: This randomized clinical trial will investigate if adding power exercises to a progressive resistance training may lead to more consistent outcomes for PFP rehabilitation. The study will provide additional knowledge to support rehabilitation programs for people with PFP. TRIAL REGISTRATION: ClinicalTrials.gov NCT03985254. Registered on 26 August 2019.


Asunto(s)
Síndrome de Dolor Patelofemoral , Entrenamiento de Fuerza , Adolescente , Adulto , Terapia por Ejercicio , Humanos , Persona de Mediana Edad , Fuerza Muscular , Síndrome de Dolor Patelofemoral/diagnóstico , Síndrome de Dolor Patelofemoral/terapia , Músculo Cuádriceps , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento , Adulto Joven
14.
Preprint en Inglés | bioRxiv | ID: ppbiorxiv-464150

RESUMEN

Infections from the SARS-CoV-2 virus have killed over 4.6 million people since it began spreading through human populations in late 2019. In order to develop a therapeutic or prophylactic antibody to help mitigate the effects of the pandemic, a human monoclonal antibody (mAb) that binds to the SARS-CoV-2 spike protein was isolated from a convalescent patient following recovery from COVID-19 disease. This mAb, designated AUG-3387, demonstrates a high affinity for the spike protein of the original viral strains and all variants tested to date. In vitro pseudovirus neutralization and SARS-CoV-2 neutralization activity has been demonstrated in vitro. In addition, a dry powder formulation has been prepared using a Thin-Film Freezing (TFF) process that exhibited a fine particle fraction (FPF) of 50.95 {+/-} 7.69% and a mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) of 3.74 {+/-} 0.73 {micro}m and 2.73 {+/-} 0.20, respectively. The dry powder is suitable for delivery directly to the lungs of infected patients using a dry powder inhaler device. Importantly, AUG-3387, administered as a liquid by intraperitoneal injection or the dry powder formulation delivered intratracheally into Syrian hamsters 24 hours after intranasal SARS-CoV-2 infection, demonstrated a dose-dependent reduction in the lung viral load of the virus. These data suggest that AUG-3387 formulated as a dry powder demonstrates potential to treat COVID-19.

16.
J Math Biol ; 83(1): 2, 2021 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-34143314

RESUMEN

Describing the anti-tumour immune response as a series of cellular kinetic reactions from known immunological mechanisms, we create a mathematical model that shows the CD4[Formula: see text]/CD8[Formula: see text] T-cell ratio, T-cell infiltration and the expression of MHC-I to be interacting factors in tumour elimination. Methods from dynamical systems theory and non-equilibrium statistical mechanics are used to model the T-cell dependent anti-tumour immune response. Our model predicts a critical level of MHC-I expression which determines whether or not the tumour escapes the immune response. This critical level of MHC-I depends on the helper/cytotoxic T-cell ratio. However, our model also suggests that the immune system is robust against small changes in this ratio. We also find that T-cell infiltration and the specificity of the intra-tumour TCR repertoire will affect the critical MHC-I expression. Our work suggests that the functional form of the time evolution of MHC-I expression may explain the qualitative behaviour of tumour growth seen in patients.


Asunto(s)
Neoplasias , Linfocitos T , Linfocitos T CD8-positivos , Humanos
17.
Am J Vet Res ; 82(5): 343-351, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33904808

RESUMEN

OBJECTIVE: To validate the use of a flow cytometric assay that uses 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) to measure reactive oxygen species in the erythrocytes of healthy dogs. ANIMALS: 50 healthy adult dogs. PROCEDURES: Erythrocytes were incubated with DCFH-DA or a vehicle control (dimethyl sulfoxide), then incubated with (stimulated) or without (unstimulated) hydrogen peroxide. The flow cytometric assay was evaluated for specificity with increasing concentrations of DCFH-DA and hydrogen peroxide, and a polynomial regression line was applied to determine optimal concentrations. For precision, samples were analyzed 5 consecutive times for determination of intra- and interassay variability. Stability of samples stored at 4°C for up to 48 hours after blood collection was determined with flow cytometric analysis. Coefficient of variation (CV) was considered acceptable at 20%. Baseline measurements were used to determine an expected range of median fluorescence intensity for unstimulated erythrocytes incubated with DCFH-DA. RESULTS: Erythrocytes were successfully isolated, and stimulated samples demonstrated higher median fluorescence intensity, compared with unstimulated samples. The intra-assay CV was 11.9% and 8.9% and interassay CV was 11.9% and 9.1% for unstimulated and stimulated samples, respectively. Unstimulated samples were stable for up to 24 hours, whereas stimulated samples were stable for up to 48 hours. CONCLUSIONS AND CLINICAL RELEVANCE: Flow cytometry for the measurement of reactive oxygen species in the erythrocytes of healthy dogs by use of DCFH-DA had acceptable specificity, precision, and stability. Flow cytometry is a promising technique for evaluating intraerythrocytic oxidative stress for healthy dogs.


Asunto(s)
Eritrocitos , Peróxido de Hidrógeno , Animales , Perros , Citometría de Flujo/veterinaria , Fluoresceínas , Especies Reactivas de Oxígeno
19.
Adv Physiol Educ ; 45(1): 103-108, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33544037

RESUMEN

The objective of this study was to determine gastrointestinal transit time in first-year health science students with a laboratory practical exercise conducted in two cohorts (classes of 2018 and 2019) of first-year health sciences students at the Health Science Campus in Windhoek, Namibia. All first-year health science students undertaking the Physiology course were invited to take part in the laboratory exercise. The primary outcome was the measurement of gastrointestinal transit time from the amount of time taken for ingested whole-kernel sweetcorn to be eliminated, which was calculated as the time period between ingestion of corn and the time of corn first seen in the stool and the time corn was last seen in the stool. The secondary outcome was an association between emotional irritability and/or anxiety and gastrointestinal transit time. The study analyzed responses of 175 students, who reported a median transit time of 29 (1-99) h. There was no difference in gastrointestinal transit time between male and female students. Likewise, there was no difference in the duration of the corn in the bowel between male and female students. Students who reported being worried and irritable during the exercise had more bowel movements before they saw corn in their stool and had slower transit times, respectively. A wider range of transit time was reported in a group of young, healthy students compared with previous studies in the literature. There were no differences between male and female student bowel activity. Anxiety did impact the bowel activity of the participants.


Asunto(s)
Tránsito Gastrointestinal , Zea mays , Defecación , Ejercicio Físico , Femenino , Humanos , Masculino , Estudiantes
20.
J Astronaut Sci ; 68(4): 1056-1144, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35001965

RESUMEN

It is often necessary to identify a pattern of observed craters in a single image of the lunar surface and without any prior knowledge of the camera's location. This so-called "lost-in-space" crater identification problem is common in both crater-based terrain relative navigation (TRN) and in automatic registration of scientific imagery. Past work on crater identification has largely been based on heuristic schemes, with poor performance outside of a narrowly defined operating regime (e.g., nadir pointing images, small search areas). This work provides the first mathematically rigorous treatment of the general crater identification problem. It is shown when it is (and when it is not) possible to recognize a pattern of elliptical crater rims in an image formed by perspective projection. For the cases when it is possible to recognize a pattern, descriptors are developed using invariant theory that provably capture all of the viewpoint invariant information. These descriptors may be pre-computed for known crater patterns and placed in a searchable index for fast recognition. New techniques are also developed for computing pose from crater rim observations and for evaluating crater rim correspondences. These techniques are demonstrated on both synthetic and real images.

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