Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 100
Filter
3.
Front Physiol ; 14: 1263500, 2023.
Article in English | MEDLINE | ID: mdl-37942230

ABSTRACT

Introduction: A hallmark of aging is poor muscle recovery following disuse atrophy. Efficacious strategies to enhance muscle recovery following disuse atrophy in aging are non-existent. Prior exercise training could result in favorable muscle morphological and cellular adaptations that may promote muscle recovery in aging. Here, we characterized the impact of exercise training on skeletal muscle inflammatory and metabolic profiles and cellular remodeling and function, together with femoral artery reactivity prior to and following recovery from disuse atrophy in aged male mice. We hypothesized that 12 weeks of treadmill training in aged male mice would improve skeletal muscle cellular remodeling at baseline and during recovery from disuse atrophy, resulting in improved muscle regrowth. Methods: Physical performance, ex vivo muscle and vascular function, tissue and organ mass, hindlimb muscle cellular remodeling (macrophage, satellite cell, capillary, myofiber size, and fibrosis), and proteolytic, inflammatory, and metabolic muscle transcripts were evaluated in aged exercise-trained and sedentary mice. Results: We found that at baseline following exercise training (vs. sedentary mice), exercise capacity and physical function increased, fat mass decreased, and endothelial function improved. However, exercise training did not alter tibialis anterior or gastrocnemius muscle transcriptional profile, macrophage, satellite cell, capillarity or collagen content, or myofiber size and only tended to increase tibialis mass during recovery from disuse atrophy. Conclusion: While exercise training in old male mice improved endothelial function, physical performance, and whole-body tissue composition as anticipated, 12 weeks of treadmill training had limited impact on skeletal muscle remodeling at baseline or in response to recovery following disuse atrophy.

4.
J Am Coll Health ; 71(6): 1887-1896, 2023.
Article in English | MEDLINE | ID: mdl-34283707

ABSTRACT

OBJECTIVE: The present study evaluated the effects of nicotine concentration (0-10 mg/ml) and flavor (gummy bear vs unflavored) on the subjective experiences of vaporized nicotine in young adult low-dose nicotine (3 mg/ml) ECIG users. PARTICIPANTS: Eight young adult ECIG users were recruited. METHODS: A single blinded crossover study was used. Participants were instructed to take ten 1.5 second puffs, each separated by 20 seconds. After self-administration, heart rate was recorded, and participants completed the Drug Effects, Direct Effects of Nicotine, and Direct Effects of ECIG questionnaires. RESULTS: ECIG user's standard daily nicotine dose influenced the rewarding and aversive effects of nicotine as the 10 mg/ml dose was found to be aversive in this user group. The combination of flavor and nicotine increased the subjective effects of ECIGs. CONCLUSIONS: Flavored e-liquids contribute to the reinforcing properties of nicotine by enhancing the subjective effects, which may lead to continued ECIG use.

5.
Emerg Infect Dis ; 28(11): 2326-2329, 2022 11.
Article in English | MEDLINE | ID: mdl-36198315

ABSTRACT

Crimean-Congo hemorrhagic fever (CCHF) was detected in 2 refugees living in a refugee settlement in Kikuube district, Uganda. Investigations revealed a CCHF IgG seroprevalence of 71.3% (37/52) in goats within the refugee settlement. This finding highlights the need for a multisectoral approach to controlling CCHF in humans and animals in Uganda.


Subject(s)
COVID-19 , Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Refugees , Animals , Humans , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/veterinary , Seroepidemiologic Studies , Uganda/epidemiology , Pandemics , Disease Outbreaks , Goats , Immunoglobulin G , Antibodies, Viral
6.
J Appl Physiol (1985) ; 133(4): 919-931, 2022 10 01.
Article in English | MEDLINE | ID: mdl-36049060

ABSTRACT

Poor recovery of muscle size and strength with aging coincides with a dysregulated macrophage response during the early stages of regrowth. Immunomodulation in the form of ex vivo cytokine (macrophage-colony stimulating factor) or polarized macrophage delivery has been demonstrated to improve skeletal muscle regeneration. However, it is unclear if these macrophage-promoting approaches would be effective to improve skeletal muscle recovery following disuse in aged animals. Here, we isolated bone marrow-derived macrophages from donor mice of different ages under various experimental conditions and polarized them into proinflammatory macrophages. Macrophages were delivered intramuscularly into young adult or aged recipient mice during the early recovery period following a period of hindlimb unloading (HU). Delivery of proinflammatory macrophages from donor young adults or aged mice was sufficient to increase muscle function of aged mice during the recovery period. Moreover, proinflammatory macrophages derived from aged donor mice collected during recovery were similarly able to increase muscle function of aged mice following disuse. In addition to the delivery of macrophages, we showed that the intramuscular injection of the cytokine, macrophage-colony stimulating factor, to the muscle of aged mice following HU was able to increase muscle macrophage content and muscle force production during recovery. Together, these results suggest that macrophage immunomodulation approaches in the form of ex vivo proinflammatory macrophage or macrophage-colony stimulating factor delivery during the early recovery phase following disuse atrophy were sufficient to restore the loss of aged skeletal muscle function.NEW & NOTEWORTHY A single intramuscular administration of polarized macrophages into muscles of aged mice following a bout of disuse atrophy was sufficient to improve functional recover similarly to young adults after disuse atrophy regardless of the age or experimental condition of the donor mice. Additionally, intramuscular delivery of macrophage-colony stimulating factor into aged mice was similarly effective. Targeting macrophage function early during the regrowth phase may be a novel tool to bolster muscle recovery in aging.


Subject(s)
Muscular Atrophy , Muscular Disorders, Atrophic , Animals , Cytokines , Hindlimb Suspension/physiology , Immunomodulation , Macrophages/pathology , Mice , Muscle, Skeletal/physiology , Muscular Disorders, Atrophic/pathology
7.
MMWR Morb Mortal Wkly Rep ; 71(9): 329-334, 2022 Mar 04.
Article in English | MEDLINE | ID: mdl-35239633

ABSTRACT

Persons infected with HIV are more likely to transmit the virus during the early stages (acute and recent) of infection, when viral load is elevated and opportunities to implement risk reduction are limited because persons are typically unaware of their status (1,2). Identifying recent HIV infections (acquired within the preceding 12 months)* is critical to understanding the factors and geographic areas associated with transmission to strengthen program intervention, including treatment and prevention (2). During June 2019, a novel recent infection surveillance initiative was integrated into routine HIV testing services in Malawi, a landlocked country in southeastern Africa with one of the world's highest prevalences of HIV infection.† The objectives of this initiative were to collect data on new HIV diagnoses, characterize the epidemic, and guide public health response (2). New HIV diagnoses were classified as recent infections based on a testing algorithm that included results from the rapid test for recent infection (RTRI)§ and HIV viral load testing (3,4). Among 9,168 persons aged ≥15 years with a new HIV diagnosis who received testing across 103 facilities during October 2019-March 2020, a total of 304 (3.3%) were classified as having a recent infection. Higher proportions of recent infections were detected among females, persons aged <30 years, and clients at maternal and child health and youth clinics. Using a software application that analyzes clustering in spatially referenced data, transmission hotspots were identified with rates of recent infection that were significantly higher than expected. These near real-time HIV surveillance data highlighted locations across Malawi, allowing HIV program stakeholders to assess program gaps and improve access to HIV testing, prevention, and treatment services. Hotspot investigation information could be used to tailor HIV testing, prevention, and treatment to ultimately interrupt transmission.


Subject(s)
Disease Hotspot , HIV Infections/diagnosis , HIV Infections/epidemiology , HIV Infections/transmission , HIV Testing/methods , Sentinel Surveillance , Spatial Analysis , Adult , Female , Humans , Malawi/epidemiology , Male , Public Health , Software , Young Adult
8.
Female Pelvic Med Reconstr Surg ; 28(2): 72-76, 2022 02 01.
Article in English | MEDLINE | ID: mdl-34171880

ABSTRACT

OBJECTIVE: The aim of this study was to determine if injection of bupivacaine into levator muscles after posterior colporrhaphy reduces postoperative pain. METHODS: This study was a multicenter, double-blinded, placebo-controlled, randomized clinical trial of 130 participants, comparing bilateral infiltration of puborectalis and iliococcygeus muscles with 0.5% bupivacaine without epinephrine or normal saline after vaginal prolapse repair that included a posterior colporrhaphy. Primary outcome was the 24-hour cumulative Visual Analog Scale (VAS) pain score (measured as a sum of VAS pain scores at postoperative hours 0, 4, 8, 16, and 24) across intervention allocations. Secondary outcomes include the individual VAS pain scores per postoperative times 0, 4, 8, 16, and 24 hours and at 1 and 2 weeks, morphine equivalent use, postoperative void trial success, and time to first bowel movement. RESULTS: Sixty-eight participants received bupivacaine, and 62 participants received normal saline. No significant differences were identified in the 24-hour postoperative cumulative VAS pain scores for the bupivacaine and normal saline arms, 19 and 18 (P = 0.71); individual pain scores per each postoperative assessment time; opiate use (24-hour use was 42 vs 48, P = 0.39; 48-hour use was 75 vs 37, P = 0.09); length of hospital stay (26 hours vs 22 hours, P = 0.069); hours to passing void trial (10 hours vs 12 hours, P = 0.17); or hours to first postoperative bowel movement (18 hours vs 12 hours, P = 0.78). CONCLUSIONS: Use of bupivacaine for muscle block after posterior colporrhaphy does not reduce postoperative pain, opiate use, and time to first bowel movement, or increase void trial success.


Subject(s)
Anesthetics, Local , Bupivacaine , Double-Blind Method , Female , Humans , Pain Measurement , Pain, Postoperative/drug therapy , Pain, Postoperative/etiology , Pain, Postoperative/prevention & control
9.
Plast Reconstr Surg Glob Open ; 9(8): e3768, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34422532

ABSTRACT

The purpose of our study is to investigate differences in normative PROMIS upper extremity function (PROMIS-UE), physical function (PROMIS-PF), and pain interference (PROMIS-PI) scores across age cohorts in individuals without upper extremity disability. METHODS: Individuals without upper extremity disability were prospectively enrolled. Subjects were administered PROMIS-UE, PROMIS-PF, and PROMIS-PI forms. Retrospective PROMIS data for eligible subjects were also utilized. The enrolled cohort was divided into age groups: 20-39, 40-59, and 60-79 years old. ANOVA, ceiling and floor effect analysis, and kurtosis and skewness statistics were performed to assess PROMIS scores trends with age. RESULTS: This study included 346 individuals. In the 20-39 age group, mean PROMIS scores were 56.2 ± 6.1, 59.8 ± 6.9, and 43.1 ± 6.7 for PROMIS-UE, PROMIS-PF, and PROMIS-PI, respectively. In the "40-59" age group, mean PROMIS computer adaptive test scores were 53.3 ± 7.5, 55.3 ± 7.6, and 46.6 ± 7.8 for PROMIS-UE, PROMIS-PF, and PROMIS-PI, respectively. In the 60-79 age group, mean PROMIS scores were 48.4 ± 7.6, 48.5 ± 5.6, and 48.7 ± 6.9 for PROMIS-UE, PROMIS-PF, and PROMIS-PI, respectively. Differences in mean PROMIS scores were significant across all PROMIS domains and age cohorts (P < 0.001). CONCLUSION: Younger individuals without hand or upper extremity disability show higher normative PROMIS-UE and PROMIS-PF scores and lower PROMIS-PI scores, indicating greater function and less pain than older counterparts. A universal reference PROMIS score of 50 appears suboptimal for clinical assessment and decision-making in the hand and upper extremity clinic.

10.
Viruses ; 13(6)2021 05 27.
Article in English | MEDLINE | ID: mdl-34072112

ABSTRACT

Hantavirus pulmonary syndrome (HPS) is an often-fatal disease caused by New World hantaviruses, such as Sin Nombre orthohantavirus (SNV). In the US, >800 cases of HPS have been confirmed since it was first discovered in 1993, of which 43 were reported from the state of Montana. The primary cause of HPS in the US is SNV, which is primarily found in the reservoir host Peromyscus maniculatus (deer mouse). The reservoir host covers most of the US, including Montana, where multiple studies found SNV in local deer mouse populations. This study aimed to check the prevalence of SNV in the deer mice at popular recreation sites throughout the Bitterroot Valley in Western Montana as compared to previous studies in western Montana. We found high prevalence (up to 20%) of deer mice positive for SNV RNA in the lungs. We were unable to obtain a SNV tissue culture isolate from the lungs but could passage SNV from lung tissue into naïve deer mice. Our findings demonstrate continuing circulation of SNV in western Montana.


Subject(s)
Disease Reservoirs/virology , Hantavirus Pulmonary Syndrome/epidemiology , Peromyscus/virology , Rodent Diseases/epidemiology , Rodent Diseases/virology , Animals , Antibodies, Viral/blood , Lung/virology , Montana/epidemiology , RNA, Viral/analysis , RNA, Viral/genetics
11.
Benef Microbes ; 12(3): 239-248, 2021 Jun 15.
Article in English | MEDLINE | ID: mdl-33789551

ABSTRACT

Implicated in several chronic diseases, the gastrointestinal microbiome is hypothesised to influence carcinogenesis. We compared faecal microbiota of newly diagnosed treatment-naïve overweight and obese cancer patients and matched controls. Cases were enrolled in presurgical weight-loss trials for breast (NCT02224807) and prostate (NCT01886677) cancers and had a body mass index (BMI) ≥25 kg/m2. Cancer-free controls were matched 1:1 by age (±5 years), race, gender, and BMI (±5 kg/m2). All participants provided faecal samples; isolated bacterial DNA were PCR amplified at the V4 region of the 16S rRNA gene and analysed using the QIIME pipeline. Tests compared cases versus controls, then separately by gender. Microbial alpha-diversity and beta-diversity were assessed, and relative abundance of Operational Taxonomic Units (OTU's) were compared at the genus level, with false discovery rate (FDR) correction. 22 overweight and obese cancer patients were matched with 22 cancer-free controls, with an average BMI of 30.5±4.3 kg/m2, age 54.4±5.3 years, and 54.5% were black. Fourteen matches were made between breast cancer cases and healthy female controls, and 8 matches were made with prostate cancer cases and healthy male controls. Comparison of all cases and controls revealed no differences in alpha diversity, though prostate cancer patients had higher Chao1 (P=0.006) and Observed Species (P=0.036) than cancer-free males. Beta-diversity metrics were significantly different between cases and controls (P<0.03 for all tests in whole sample and in men), though only unweighted Unifrac was different in women (P=0.005). Kruskal Wallis tests indicated significant differences among 16 genera in all matches, 9 in female, and 51 in male. This study suggests the faecal microbiota of treatment-naive breast and prostate cancer patients differs from controls, though larger samples are needed to substantiate these findings. Trial registration: NIH Clinical Trials, NCT01886677, NCT02224807, registered 26 June 2013, 25 Aug 2014 (respectively) - retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT01886677; https://clinicaltrials.gov/ct2/show/NCT02224807.


Subject(s)
Breast Neoplasms/microbiology , Gastrointestinal Microbiome , Prostatic Neoplasms/microbiology , Case-Control Studies , Feces/microbiology , Female , Humans , Male , Middle Aged , Obesity/microbiology , Overweight/microbiology , Randomized Controlled Trials as Topic
12.
J Am Geriatr Soc ; 69(3): 581-586, 2021 03.
Article in English | MEDLINE | ID: mdl-33370463

ABSTRACT

BACKGROUND/OBJECTIVE: Recommendations for infection prevention and control (IPC) of COVID-19 in long-term care settings were developed based on limited understanding of COVID-19 and should be evaluated to determine their efficacy in reducing transmission among high-risk populations. DESIGN AND SETTING: Site visits to 24 long-term care facilities (LTCFs) in Fulton County, Georgia, were conducted between June and July 2020 to assess adherence to current guidelines, provide real-time feedback on potential weaknesses, and identify specific indicators whose implementation or lack thereof was associated with higher or lower prevalence of COVID-19. PARTICIPANTS: Twenty-four LTCFs were visited, representing 2,580 LTCF residents, among whom 1,004 (39%) were infected with COVID-19. MEASUREMENTS: Overall IPC adherence in LTCFs was analyzed for 33 key indicators across five categories: Hand Hygiene, Disinfection, Social Distancing, PPE, and Symptom Screening. Facilities were divided into Higher- and Lower-prevalence groups based on cumulative COVID-19 infection prevalence to determine differences in IPC implementation. RESULTS: IPC implementation was lowest in the Disinfection category (32%) and highest in the Symptom Screening category (74%). Significant differences in IPC implementation between the Higher- and Lower-prevalence groups were observed in the Social Distancing category (Higher-prevalence group 54% vs Lower-prevalence group 74%, P < .01) and the PPE category (Higher-prevalence group 41% vs Lower-prevalence group 72%, P < .01). CONCLUSION: LTCFs with lower COVID-19 prevalence among residents had significantly greater implementation of IPC recommendations compared to those with higher COVID-19 prevalence, suggesting the utility in adhering to current guidelines to reduce transmission in this vulnerable population.


Subject(s)
COVID-19/prevention & control , Guideline Adherence/statistics & numerical data , Homes for the Aged/statistics & numerical data , Infection Control/standards , Long-Term Care/standards , Residential Facilities/statistics & numerical data , Aged , Female , Georgia , Homes for the Aged/standards , Humans , Male , Residential Facilities/standards , SARS-CoV-2
13.
MMWR Morb Mortal Wkly Rep ; 69(37): 1296-1299, 2020 Sep 18.
Article in English | MEDLINE | ID: mdl-32941413

ABSTRACT

Long-term care facility (LTCF) residents are at particularly high risk for morbidity and mortality associated with infection with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), given their age and high prevalence of chronic medical conditions, combined with functional impairment that often requires frequent, close contact with health care providers, who might inadvertently spread the virus to residents (1,2). During March-May 2020 in Fulton County, Georgia, >50% of COVID-19-associated deaths occurred among LTCF residents, although these persons represented <1% of the population (3,4). Mass testing for SARS-CoV-2 has been an effective strategy for identifying asymptomatic and presymptomatic infections in LTCFs (5). This analysis sought to evaluate the timing at which mass testing took place in relation to the known presence of a COVID-19 infection and the resulting number of infections that occurred. In 15 LTCFs that performed facility-wide testing in response to an identified case, high prevalences of additional cases in residents and staff members were found at initial testing (28.0% and 7.4%, respectively), suggesting spread of infection had already occurred by the time the first case was identified. Prevalence was also high during follow-up, with a total of 42.4% of residents and 11.8% of staff members infected overall in the response facilities. In comparison, 13 LTCFs conducted testing as a preventive strategy before a case was identified. Although the majority of these LTCFs identified at least one COVID-19 case, the prevalence was significantly lower at initial testing in both residents and staff members (0.5% and 1.0%, respectively) and overall after follow-up (1.5% and 1.7%, respectively). These findings indicate that early awareness of infections might help facilities prevent potential outbreaks by prioritizing and adhering more strictly to infection prevention and control (IPC) recommendations, resulting in fewer infections than would occur when relying on symptom-based screening (6,7).


Subject(s)
Clinical Laboratory Techniques , Coronavirus Infections/prevention & control , Disease Outbreaks/prevention & control , Mass Screening/methods , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Residential Facilities/organization & administration , Aged , COVID-19 , COVID-19 Testing , Coronavirus Infections/diagnosis , Coronavirus Infections/epidemiology , Georgia/epidemiology , Humans , Pneumonia, Viral/epidemiology
14.
Preprint in English | medRxiv | ID: ppmedrxiv-20174466

ABSTRACT

Through infection prevention and control (IPC) site visits to 23 LTCFs in Fulton County, Georgia, comparison between the Higher- and Lower-prevalence groups revealed significant differences in PPE and Social Distancing, with five specific indicators driving these differences.

15.
Nat Commun ; 11(1): 2062, 2020 04 28.
Article in English | MEDLINE | ID: mdl-32346060

ABSTRACT

Two-Photon Microscopy has become an invaluable tool for biological and medical research, providing high sensitivity, molecular specificity, inherent three-dimensional sub-cellular resolution and deep tissue penetration. In terms of imaging speeds, however, mechanical scanners still limit the acquisition rates to typically 10-100 frames per second. Here we present a high-speed non-linear microscope achieving kilohertz frame rates by employing pulse-modulated, rapidly wavelength-swept lasers and inertia-free beam steering through angular dispersion. In combination with a high bandwidth, single-photon sensitive detector, this enables recording of fluorescent lifetimes at speeds of 88 million pixels per second. We show high resolution, multi-modal - two-photon fluorescence and fluorescence lifetime (FLIM) - microscopy and imaging flow cytometry with a digitally reconfigurable laser, imaging system and data acquisition system. These high speeds should enable high-speed and high-throughput image-assisted cell sorting.


Subject(s)
Microscopy, Fluorescence, Multiphoton , Euglena/cytology , Imaging, Three-Dimensional , Time Factors
16.
Br J Pharmacol ; 177(10): 2256-2273, 2020 05.
Article in English | MEDLINE | ID: mdl-31968123

ABSTRACT

BACKGROUND AND PURPOSE: Respiratory viral infections play central roles in the initiation, exacerbation and progression of asthma in humans. An acute paramyxoviral infection in mice can cause a chronic lung disease that resembles human asthma. We sought to determine whether reduction of Sendai virus lung burden in mice by stimulating innate immunity with aerosolized Toll-like receptor (TLR) agonists could attenuate the severity of chronic asthma-like lung disease. EXPERIMENTAL APPROACH: Mice were treated by aerosol with 1-µM oligodeoxynucleotide (ODN) M362, an agonist of the TLR9 homodimer, and 4-µM Pam2CSK4 (Pam2), an agonist of the TLR2/6 heterodimer, within a few days before or after Sendai virus challenge. KEY RESULTS: Treatment with ODN/Pam2 caused ~75% reduction in lung Sendai virus burden 5 days after challenge. The reduction in acute lung virus burden was associated with marked reductions 49 days after viral challenge in eosinophilic and lymphocytic lung inflammation, airway mucous metaplasia, lumenal mucus occlusion and hyperresponsiveness to methacholine. Mechanistically, ODN/Pam2 treatment attenuated the chronic asthma phenotype by suppressing IL-33 production by type 2 pneumocytes, both by reducing the severity of acute infection and by down-regulating Type 2 (allergic) inflammation. CONCLUSION AND IMPLICATIONS: These data suggest that treatment of susceptible human hosts with aerosolized ODN and Pam2 at the time of a respiratory viral infection might attenuate the severity of the acute infection and reduce initiation, exacerbation and progression of asthma.


Subject(s)
Asthma , Hypersensitivity , Pneumonia , Virus Diseases , Animals , Asthma/drug therapy , Asthma/prevention & control , Lung , Mice , Mice, Inbred BALB C
17.
ACS Sens ; 5(2): 385-394, 2020 02 28.
Article in English | MEDLINE | ID: mdl-31902202

ABSTRACT

Nucleic acid amplification assays including loop-mediated isothermal amplification (LAMP) are routinely used in diagnosing diseases and monitoring water and food quality. The results of amplification in these assays are commonly measured with an analog fluorescence readout, which requires specialized optical equipment and can lack quantitative precision. Digital analysis of amplification in small fluid compartments based on exceeding a threshold fluorescence level can enhance the quantitative precision of nucleic acid assays (i.e., digital nucleic acid amplification assays), but still requires specialized optical systems for fluorescence readout and the inclusion of a fluorescent dye. Here, we report Fractal LAMP, an automated method to detect amplified DNA in subnanoliter scale droplets following LAMP in a label-free manner. Our computer vision algorithm achieves high accuracy detecting DNA amplification in droplets by identifying LAMP byproducts that form fractal structures observable in brightfield microscopy. The capabilities of Fractal LAMP are further realized by developing a Bayesian model to estimate DNA concentrations for unknown samples and a bootstrapping method to estimate the number of droplets required to achieve target limits of detection. This digital, label-free assay has the potential to lower reagent and reader cost for nucleic acid measurement while maintaining high quantitative accuracy over 3 orders of magnitude of concentration.


Subject(s)
Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods
18.
Biotechnol Bioeng ; 117(1): 223-237, 2020 01.
Article in English | MEDLINE | ID: mdl-31612990

ABSTRACT

In vivo mesenchymal stem cell (MSC) survival is relevant to therapeutic applications requiring engraftment and potentially to nonengraftment applications as well. MSCs are a mixture of progenitors at different stages of cellular aging, but the contribution of this heterogeneity to the survival of MSC implants is unknown. Here, we employ a biomarker of cellular aging, the decoy TRAIL receptor CD264, to compare the survival kinetics of two cell populations in human bone marrow MSC (hBM-MSC) cultures. Sorted CD264+ hBM-MSCs from two age-matched donors have elevated ß-galactosidase activity, decreased differentiation potential and form in vitro colonies inefficiently relative to CD264- hBM-MSCs. Counterintuitive to their aging phenotype, CD264+ hBM-MSCs exhibited comparable survival to matched CD264- hBM-MSCs from the same culture during in vitro colony formation and in vivo when implanted ectopically in immunodeficient NIH III mice. In vitro and in vivo survival of these two cell populations were independent of colony-forming efficiency. These findings have ramifications for the preparation of hBM-MSC therapies given the prevalence of aging CD264+ cells in hBM-MSC cultures and the popularity of colony-forming efficiency as a quality control metric in preclinical and clinical studies with MSCs.


Subject(s)
Cell Survival/physiology , Cellular Senescence/physiology , Mesenchymal Stem Cells , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , Adult , Animals , Cell Differentiation/physiology , Cells, Cultured , Female , Humans , Male , Mesenchymal Stem Cells/chemistry , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/physiology , Mice
19.
Heliyon ; 5(10): e02752, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31720480

ABSTRACT

An experimental investigation of thermoelectric cooling using a Peltier element to dehumidify moist air under controlled, high relative humidity conditions has been conducted. The influence of the cold side heatsink orientation on the water collection rate was experimentally determined. One finned heatsink-fan combination was used on the heat rejection side. On the cold side flat plates, uncoated and Polytetrafluoroethylene (PTFE) coated, a fanned plate with four fins, and a heatsink having 15 fins were used. The PTFE coated plate showed up to a 30% higher water collection rate (expressed in L/kWh) compared to the uncoated flat plate that has the same surface area. Clearing the surfaces-removing all condensate every hour-increased the water collection rate by up to 18% for the flat plates. The finned heatsink and the PTFE coated flat plate were used for the orientation experiments. The finned heatsink was rotated from 0° to 90°, as well as tilted from 0° to 90° (vertical to horizontal). To investigate the effect of surface orientation on a single-side collection surface in isolation, the PTFE coated flat plate was tilted from 15° to 165° in 15° increments. The highest collection rates are found for a rotation angle of 60° and a tilted angle of 75° for the finned heatsink, 0.249 L/kWh and 0.221 L/kWh respectively. The highest measured collection rate for the PTFE coated plate is 0.319 L/kWh at an orientation of 15° from the horizontal. Experiments for the horizontal orientation of the finned heatsink show that once the spaces between the fins are completely filled with water the collection rate drops by an order of magnitude, from 0.203 L/kWh to 0.026 L/kWh. The experiments show that the orientation of a thermoelectric heatsink should be considered when optimizing the water collection rates under high humidity conditions for thermoelectric cooling heatsinks.

SELECTION OF CITATIONS
SEARCH DETAIL
...