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BACKGROUND: Hybrid closed-loop (HCL) systems, also known as automated insulin delivery systems, are a rapidly growing technology in diabetes management. Because more patients are using these systems in the outpatient setting, it is important to also assess inpatient safety to determine whether HCL use can be continued when those patients become hospitalized. METHODS: The records of patients using HCL technology on admission to our hospital between June 1, 2020, and June 30, 2021, were analyzed. RESULTS: The final analysis included 71 patients divided into 3 categories based on their pump use as an inpatient: (1) HCL users; (2) manual pump users; and (3) pump removed. All cohorts were similar in age, sex, race, hemoglobin A1C at admission, and in Medicare Severity Diagnosis Related Group. Pairwise comparisons indicated that patient-stay mean glucose levels, frequency of patient-specific hyperglycemic measurements, and frequency of hypoglycemic events were similar between all groups. No adverse events, particularly occurrences of diabetic ketoacidosis, pump site complications or infection, or equipment malfunction, were reported. CONCLUSION: This preliminary case series review indicates that continued use of HCL technology in the hospital is safe. Moreover, glycemic control in HCL users was comparable with that in those using insulin pump with manual settings and those converted to basal-bolus insulin therapy.
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Diabetes Mellitus Tipo 1 , Estados Unidos , Humanos , Idoso , Diabetes Mellitus Tipo 1/tratamento farmacológico , Glicemia/análise , Insulina/efeitos adversos , Pacientes Internados , Sistemas de Infusão de Insulina , Medicare , Hipoglicemiantes/efeitos adversos , Tecnologia , Automonitorização da GlicemiaRESUMO
The objective of this study is to measure the prevalence and demographic predictors of depressive symptoms in a diverse group of adolescent athletes. Retrospective chart review of demographic and Patient Health Questionnaire-Adolescent (PHQ-A) data obtained during a mass pre-participation physical exam (PPE) was examined. Independent variables included race and sex. A total of 16.9% (n = 115) of students had clinically meaningful depressive symptoms, while 2.5% (n = 23) reported having thoughts that they would be better off dead or of hurting themselves. Of those who had moderate to severe levels of depressive symptoms, 25.8% (n = 31) were Black females, significantly more than any other race-sex group. A majority of our sample did not have depressive symptoms but a plan for those in severe mental distress must be in place. Prevalence of adolescent depressive symptoms, mental health emergency preparedness and culturally sensitive interventions deserve further investigation. (Journal of Surgical Orthopaedic Advances 31(3):193-198, 2022).
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Atletas , Depressão , Feminino , Adolescente , Humanos , Prevalência , Depressão/epidemiologia , Depressão/diagnóstico , Estudos Retrospectivos , Atletas/psicologia , Estudantes/psicologiaRESUMO
Wildlife conservation and management on military lands must be accomplished in the context of military readiness, which often includes ground-based training that is perceived to conflict with wildlife needs and environmental regulations. From 2008â2012, we examined territory density, pairing success, and fledging success of the federally endangered golden-cheeked warbler (Setophaga chrysoparia; hereafter warbler) in relation to removal of small-diameter trees from the understory of mature oak-juniper (Quercus-Juniperus) woodland at the 87,890 ha Fort Hood Military Reservation in central Texas. Understory thinning created troop maneuver lanes, but left canopy vegetation intact. Warbler density, pairing success, and fledging success were similar across thinned and control sites. We found that warbler pairing and fledging success were best predicted by Ecological site (hereafter Ecosite), an indicator of hardwood tree species composition. Warbler pairing and fledging success were about 1.5 and 1.6 times higher, respectively, for territories dominated by the Low Stony Hill Ecosite than territories dominated by the Redlands Ecosite. Our results indicate that understory thinning for military training purposes did not have a negative effect on warblers at Fort Hood in the manner tested, and suggest that removal of smaller trees from the understory in a way that replicates historic conditions may elicit neutral responses from this forest-dependent songbird. Quantifying wildlife responses to military activities provides the Department of Defense and US Fish and Wildlife Service with data to guide conservation of threatened and endangered species on Department of Defense facilities while maintaining the military mission, and supports wildlife management efforts on other public and private lands.
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Conservação dos Recursos Naturais/métodos , Espécies em Perigo de Extinção , Monitoramento Ambiental/métodos , Juniperus/crescimento & desenvolvimento , Quercus/crescimento & desenvolvimento , Aves Canoras/crescimento & desenvolvimento , Animais , Ecossistema , Florestas , Aves Canoras/fisiologia , TexasRESUMO
OBJECTIVES: The association of tenofovir (TDF) with nephrotoxicity has been a controversial issue. Few studies are published regarding the reversibility of renal dysfunction once TDF is discontinued. Studies have yet to be conducted in an urban, non-white patient population, making this one of the largest studies observing a non-white cohort. The objective of this study was to determine whether the decline in creatinine clearance (CrCL) associated with TDF use is reversible once TDF is discontinued in a non-white patient population. METHODS: This single-center, retrospective, chart review was performed at an urban outpatient HIV clinic. Patients who had been switched from tenofovir to zidovudine or abacavir because of a decline in renal function were included. The primary endpoint was the percentage of patients who regained full, moderate, mild, or no recovery of CrCl. RESULTS: Sixty-two patients were included. The mean age was 50 years old, 82% were black, and 66% were males with a mean baseline CrCL of 76 ml/min. Mean difference in CrCL from baseline to 12 months post-TDF was shown to be -11.34 ml/min. After a 1-year follow up period, 37.5% of patients had a full recovery of their baseline CrCL. An additional 41% of patients achieved a moderate recovery (80%-99% of baseline CrCL) and 17.9% patients had a mild recovery (50%-79% of baseline CrCL). Two patients required dialysis. The percent of patients with an undetectable HIV RNA while on a TDF-containing regimen was 67.1% compared with 74.6% on alternative ART. CONCLUSION: Renal dysfunction caused by TDF was fully reversible in 37.5% of patients. Improvement to at least 50% of baseline was seen in 96.4% of patients. Viral suppression was not compromised when patient was switched from TDF to an alternative nucleoside reverse transcriptase inhibitor.
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Injúria Renal Aguda/induzido quimicamente , Fármacos Anti-HIV/efeitos adversos , Infecções por HIV/tratamento farmacológico , Tenofovir/efeitos adversos , População Urbana , Injúria Renal Aguda/etnologia , Adulto , Negro ou Afro-Americano , Idoso , Fármacos Anti-HIV/uso terapêutico , Feminino , Taxa de Filtração Glomerular , Infecções por HIV/etiologia , Hispânico ou Latino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tenofovir/uso terapêuticoRESUMO
Though it may appear counterintuitive, certain positive attributes can eventually have negative consequences when taken to an extreme. This concept is exemplified in sports, where an increase in talent among team members initially leads to improved success, but beyond a certain threshold, excessive talent can adversely affect the team. This occurrence is known as the Too Much Talent (TMT) effect, wherein status conflicts among highly skilled players can hinder team performance, particularly in sports that require coordination and cooperation. While early evidence supported the TMT effect in team sports, its validity has recently been challenged. In this study, we analyzed a comprehensive dataset consisting of 780 data points across 42 seasons from seven top European football (soccer) leagues to examine the TMT effect's presence. Our findings reveal that football does not exhibit the TMT effect. Instead, we observed a consistent, positive correlation between the number of skilled players on a team and team success. Additionally, talent did not display diminishing returns, as its impact on success remained stable even at the highest concentrations of talent. We relate our results to existing theories and propose that future research comparing more individualistic and interdependent team sports could further enhance the field.
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Desempenho Atlético , Futebol , Logro , Esportes de Equipe , AptidãoRESUMO
Urban environments expose wildlife to levels of anthropogenic noise they would not experience in rural areas (e.g., traffic noise), and research suggests that many species adjust their acoustic signals for optimal transmission in urban soundscapes. However, our understanding of anuran (order Anura) responses to noise pollution in urban environments of the southeastern United States is limited, particularly for species that can breed during winter. Our goal was to examine how vocal anuran advertisement call characteristics during winter varied with increasing distance from roadways in bottomland hardwoods of Louisiana, USA. We deployed acoustic recording units at two sites (i.e., rural and urban) perpendicular to Interstate 10 at 200-, 400-, and 600-m intervals (i.e., close, middle, and far) from November 2019 to January 2020. We detected Cajun Chorus Frogs (Pseudacris fouquettei) and Cricket Frogs (Acris spp.) at our rural site, and only detected Cricket Frogs at our urban site. At the rural site, Cajun Chorus Frogs produced longer duration notes at the far location compared to the middle location. At the urban site, Cricket Frogs produced higher dominant frequency calls at the close location compared to the far and middle locations and longer duration notes at the far location compared to the close location. We were unable to account for additional factors in our models (e.g., temperature, noise levels), but our results generally align with previous research. Our study provides baseline data for future research to examine the potential effects of traffic noise on winter advertisement calls in locations with similar environmental conditions and species.
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The miniaturization of satellite systems has compounded the need to protect microelectronic components from damaging radiation. Current approaches to mitigate this damage, such as indiscriminate mass shielding, built-in redundancies, and radiation-hardened electronics, introduce high size, weight, power, and cost penalties that impact the overall performance of the satellite or launch opportunities. Additive manufacturing provides an appealing strategy to deposit radiation shielding only on susceptible components within an electronic assembly. Here, a versatile material platform and process to conformally print customized composite inks at room temperature directly and selectively onto commercial-off-the-shelf electronics is described. The suite of inks uses a flexible styrene-isoprene-styrene block copolymer binder that can be filled with particles of different atomic densities for diverging radiation shielding capabilities. Additionally, the system enables the combination of multiple distinct particle species within the same printed structure. The method can produce graded shielding that offers improved radiation attenuation by tailoring both shield geometry and composition to provide comprehensive protection from a broad range of radiation species. The authors anticipate this alternative to traditional shielding methods will enable the rapid proliferation of the next generation of compact satellite designs.
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BACKGROUND: The reconstitution of membrane proteins and complexes into nanoscale lipid bilayer structures has contributed significantly to biochemical and biophysical analyses. Current methods for performing such reconstitutions entail an initial detergent-mediated step to solubilize and isolate membrane proteins. Exposure to detergents, however, can destabilize many membrane proteins and result in a loss of function. Amphipathic copolymers have recently been used to stabilize membrane proteins and complexes following suitable detergent extraction. However, the ability of these copolymers to extract proteins directly from native lipid bilayers for subsequent reconstitution and characterization has not been explored. RESULTS: The styrene-maleic acid (SMA) copolymer effectively solubilized membranes of isolated mitochondria and extracted protein complexes. Membrane complexes were reconstituted into polymer-bound nanoscale discs along with endogenous lipids. Using respiratory Complex IV as a model, these particles were shown to maintain the enzymatic activity of multicomponent electron transporting complexes. CONCLUSIONS: We report a novel process for reconstituting fully operational protein complexes directly from cellular membranes into nanoscale lipid bilayers using the SMA copolymer. This facile, single-step strategy obviates the requirement for detergents and yields membrane complexes suitable for structural and functional studies.
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Biotecnologia/métodos , Proteínas de Membrana/isolamento & purificação , Membranas Mitocondriais/enzimologia , Complexos Multienzimáticos/isolamento & purificação , Nanopartículas/química , Maleatos/química , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Modelos Biológicos , Complexos Multienzimáticos/química , Complexos Multienzimáticos/metabolismo , Nanopartículas/metabolismo , Poliestirenos/química , Saccharomyces cerevisiae/enzimologia , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/isolamento & purificação , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
The purpose of this study was to compare the motor performance of tongue, using Tongue Drive System, to hand operation for relatively complex tasks under different levels of background physical exertion. Thirteen young able-bodied adults performed tasks that tested the accuracy and variability in tracking a sinusoidal waveform, and the performance in playing two video games that require accurate and rapid movements with cognitive processing using tongue and hand under two levels of background physical exertion. Results show additional background physical activity did not influence rapid and accurate displacement motor performance, but compromised the slow waveform tracking and shooting performances in both hand and tongue. Slow waveform tracking performance by the tongue was compromised with an additional motor or cognitive task, but with an additional motor task only for the hand.
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Mãos/fisiologia , Análise e Desempenho de Tarefas , Língua/fisiologia , Adulto , Feminino , Humanos , Masculino , Movimento/fisiologia , Esforço Físico , Interface Usuário-Computador , Jogos de Vídeo , Carga de Trabalho , Adulto JovemRESUMO
CONTEXT: Depression is among the most common mental health disorders in youth, results in significant impairment, and is associated with a higher risk of suicide. Screening is essential, but assessment tools may not account for the complex interrelatedness of various demographic factors, such as sex, socioeconomic status, and race. OBJECTIVES: To determine the (1) the factor structure of the Patient Health Questionnaire-Adolescent (PHQ-A) for measuring depression in a group of adolescent athletes and (2) measurement invariance between Black and White patients on the PHQ-A. DESIGN: Retrospective cohort design. SETTING: Data were obtained from a secure database collected at a free, comprehensive, mass preparticipation physical examination event hosted by a large health care system. PATIENTS OR OTHER PARTICIPANTS: Participants were 683 high school athletes (Black = 416, White = 267). The independent variables were somatic and affective factors contributing to the construct of depression measured by the PHQ-A and participant race (Black or White). MAIN OUTCOME MEASURE(S): (1) Factors upon which the construct of depression is measured and (2) measurement invariance between Black and White participants. RESULTS: A 2-factor model, involving affective and somatic components, was specified and exhibited adequate fit to the data (comparative fit index >0.90). All items exhibited moderate to high squared multiple correlation values (R2 = 0.10-0.65), suggesting that these items resonated relatively well with participants. The 2-factor model demonstrated noninvariance between Black and White participants (root mean square error of approximation = 0.06-0.08). CONCLUSIONS: Overall, the structure of the PHQ-A was supported by a 2-factor model in adolescent athletes, measuring both affective and somatic symptoms of depression. However, a 2-factor PHQ-A structure was not fully invariant for the adolescents sampled across participant groups, indicating that the model functioned differently between the Black and White participants sampled.
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Depressão , Questionário de Saúde do Paciente , Adolescente , Depressão/diagnóstico , Humanos , Programas de Rastreamento , Psicometria , Reprodutibilidade dos Testes , Estudos Retrospectivos , Instituições Acadêmicas , Inquéritos e QuestionáriosRESUMO
Acoustic communication allows animals to coordinate and optimize resource utilization in space. Cardioderma cor, the heart-nosed bat, is one of the few species of bats known to sing during nighttime foraging. Previous research found that heart-nosed bats react aggressively to song playback, supporting the territorial defense hypothesis of singing in this species. We further investigated the territorial defense hypothesis from an ecological standpoint, which predicts that singing should be associated with exclusive areas containing a resource, by tracking 14 individuals nightly during the dry seasons in Tanzania. We quantified the singing behavior of individuals at all perches used throughout the night. Using home range analysis tools, we quantified overall use, night ranges and singing ranges, as well as areas used in early and later time periods at night. Males sang back and forth from small ( x ¯ = 3.48 ± 2.71 ha), largely exclusive areas that overlapped with overall night ranges used for gleaning prey. Individuals varied in singing effort; however, all sang significantly more as night progressed. Subsequently, areas used earlier at night and overall use areas were both larger than singing areas. Individuals varied in singing strategies. Some males sang for long periods in particular trees and had smaller core areas, while others moved frequently among singing trees. The most prolific singers used more perches overall. Our results support the hypothesis that acoustic communication repertoires evolved in support of stable foraging territory advertisement and defense in some bats.
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From August to December 2018, we collected blood samples from 98 individuals of 11 mammal species to examine seroprevalence of leptospirosis at the Sherburne Wildlife Management Area in central Louisiana, US. Overall, 21.4% of individuals tested positive for antibodies of at least one Leptospira interrogans serovar and six individuals were reactive for two or more serovars. The most prevalent serovar we detected was serovar Bratislava (19.4%), followed by serovar Grippotyphosa (6.1%), serovar Icterohaemorrhagiae and serovar Pomona (2.0%), and serovar Canicola and serovar Hardjo (1.0%). We detected the highest prevalence in fox squirrels (Sciurus niger), hispid cotton rats (Sigmodon hispidus), and feral swine (Sus scrofa), with serovar Bratislava being the most reactive for these three species. Positive samples returned titer results of 100-400 for all species and serovars, with the exception of one feral swine that returned a titer of 1,600 to serovar Bratislava, indicating an active infection. Although the potential effects of leptospirosis on our study species remains unclear, our data contribute information necessary to understand and manage potential risks of Leptospira exposure to wildlife, domestic animals, and humans.
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Leptospira , Leptospirose , Animais , Animais Selvagens , Anticorpos Antibacterianos , Leptospirose/epidemiologia , Leptospirose/veterinária , Louisiana/epidemiologia , Mamíferos , Estudos SoroepidemiológicosRESUMO
OBJECTIVE: The performing arts style of cirque has grown in popularity, with high-school participants increasingly practicing this style. Still, little research has examined the injury reporting rates and patterns in this population. Our study aimed to compare injury reporting rates and injury concealment patterns between high-school cirque performers and a peer-group of basketball players. METHODS: Fifty participants (30 cirque, 20 basketball) completed a 12-item injury history and concealment instrument with chi-squared analyses and Fisher's exact tests comparing groups (p = 0.05). RESULTS: While no group differences (p = 0.36) existed in injuries reported, basketball players were more likely (p = 0.01) to miss participation due to injury than cirque performers. No significant difference existed between participants regarding which healthcare provider they reported to first (p = 0.27), but basketball players reported their injuries to the athletic trainer at higher rates (50%) than cirque performers (20%). A nonsignificant trend (p = 0.08) was noted in promptness to report injury, with more cirque performers (13%) concealing their injuries than basketball players (5%). Several reasons were noted for concealment of injury, with the most common being the belief that the injury would "go away" on its own. Knee injuries were most common in basketball players (23.7%) and back and knee injuries (10.5% each) in cirque performers. CONCLUSIONS: Despite similar injury rates, cirque participants concealed injuries more than peer-basketball players. Reasons may include losing performance roles, unfamiliarity and low trust with healthcare providers, ignorance about initially minor-looking injuries, and higher pain tolerance thresholds. Education and communication are essential to allow performing artists to seek healthcare support. Research is needed to appropriately understand and meet the needs of this underserved performing artist population.
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Traumatismos em Atletas/epidemiologia , Basquetebol/lesões , Ginástica/lesões , Aceitação pelo Paciente de Cuidados de Saúde , Adolescente , Serviços de Saúde do Adolescente , Traumatismos em Atletas/etiologia , Feminino , Humanos , Traumatismos do Joelho/epidemiologia , Traumatismos do Joelho/etiologia , Masculino , Entorses e Distensões/epidemiologia , Entorses e Distensões/etiologia , Estudantes , Estados Unidos/epidemiologiaRESUMO
Necrotizing soft tissue infections are aggressive infections that cause necrosis of muscle, fascia, and tissue. They typically follow fascial planes that lack insufficient blood supply. Early drainage and debridement are essential for survival in these patients. This is a case of a patient who presented in diabetic ketoacidosis with a necrotizing soft tissue infection localized to the left flank and abdomen with underlying colon cancer pathology. The patient was a 54-year-old female who initially presented with acute dyspnea and left flank pain for two weeks. On admission, she was afebrile, tachycardic, tachypneic, and hypertensive. After being transferred to the ICU for diabetic ketoacidosis management, she began complaining of left abdominal pain and the CT showed concerns for a possible necrotizing soft tissue infection in the left flank region. She was taken to the operating room immediately for debridement and started on broad-spectrum antibiotics. The next day, an exploratory laparotomy was performed with a hemicolectomy and creation of an end colostomy due to concern for a perforated colonic malignancy. A final debridement was completed and a wound vacuum-assisted closure (VAC) was placed. Final pathology demonstrated well-differentiated colonic adenocarcinoma invading into the muscularis propria. Overall, necrotizing soft tissue infections can be related to a perforated viscus especially a colonic malignancy and this case demonstrates the importance of proper surgical management and high clinical suspicion for possible underlying pathology in a soft tissue infection.
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OBJECTIVE: To determine the relationship between admissions criteria and grade point average (GPA) at the conclusion of the first-term of study at a chiropractic institution. METHODS: Secondary data analysis was used on the Fall 2017 entering cohort of doctor of chiropractic students. Independent samples t-tests and ordinary least squares linear regression were used to explain the extent to which incoming undergraduate GPA, undergraduate chemistry grade, undergraduate anatomy and physiology grade, and age, respectfully, influenced the end-of-trimester GPA. RESULTS: Linear regression found each of the four independent variables (undergraduate GPA, undergraduate chemistry grade, undergraduate anatomy and physiology grade, and age) to be significant influencers of end-of-trimester-1 GPA with undergraduate GPA being the most statistically significant predictor (p < .001).The difference in mean end-of-trimester GPAs for male and female students was not statistically significant. There also was no difference in mean end-of-trimester GPAs by race/ethnicity. CONCLUSION: Current admissions requirements may need to emphasize incoming undergraduate GPA and target student support for older students. This study should be repeated for increased sample size, be performed at other chiropractic institutions, and consider additional cohorts to strengthen results.
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Social work's ability to address complex societal problems such as those identified in the American Academy of Social Work and Social Welfare's Grand Challenges for Social Work is reliant on being innovative in how we prepare social workers and how we collaborate with others, including business. This research seeks to understand how leaders of major social work organizations perceive potential partnership with the business sector-including both possible threats and opportunities. Interviews were conducted with those serving on the Council on Social Work Education's Leadership Roundtable. The research explores how emerging partnership models can be helpful and ways in which the profession can prepare practitioners for better partnering with the business sector. Qualitative findings identify four key strategies to address the grand challenges and enhance partnerships: (1) more interdisciplinary work is needed, (2) social work students need to be adequately equipped for collaborative work, (3) a cohesive message is needed from the field, and (4) the potential benefits for partnering with business outweigh the risks.
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Anthropogenic noise associated with highway construction and operation can have individual- and population-level consequences for wildlife (e.g., reduced densities, decreased reproductive success, behavioral changes). We used a before-after control-impact study design to examine the potential impacts of highway construction and traffic noise on endangered golden-cheeked warblers (Setophaga chrysoparia; hereafter warbler) in urban Texas. We mapped and monitored warbler territories before (2009-2011), during (2012-2013), and after (2014) highway construction at three study sites: a treatment site exposed to highway construction and traffic noise, a control site exposed only to traffic noise, and a second control site exposed to neither highway construction or traffic noise. We measured noise levels at varying distances from the highway at sites exposed to construction and traffic noise. We examined how highway construction and traffic noise influenced warbler territory density, territory placement, productivity, and song characteristics. In addition, we conducted a playback experiment within study sites to evaluate acute behavioral responses to highway construction noises. Noise decreased with increasing distance from the highways. However, noise did not differ between the construction and traffic noise sites or across time. Warbler territory density increased over time at all study sites, and we found no differences in warbler territory placement, productivity, behavior, or song characteristics that we can attribute to highway construction or traffic noise. As such, we found no evidence to suggest that highway construction or traffic noise had a negative effect on warblers during our study. Because human population growth will require recurring improvements to transportation infrastructure, understanding wildlife responses to anthropogenic noise associated with the construction and operation of roads is essential for effective management and recovery of prioritized species.
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Whole-brain irradiation is used for the treatment of brain tumors, but can it also induce neural changes, with progressive dementia occurring in 20-50% of long-term survivors. The present study investigated whether 45 Gy of whole-brain irradiation delivered to 12-month-old Fischer 344 x Brown Norway rats as nine fractions over 4.5 weeks leads to impaired Morris water maze (MWM) performance 12 months later. Compared to sham-irradiated rats, the irradiated rats demonstrated impaired MWM performance. The relative levels of the NR1 and NR2A but not the NR2B subunits of the NMDA receptor were significantly higher in hippocampal CA1 of irradiated rats compared to control rats. No significant differences were detected for these NMDA subunits in CA3 or dentate gyrus. Further analysis of CA1 revealed that the relative levels of the GluR1 and GluR2 subunits of the AMPA receptor and synaptophysin were not altered by whole-brain irradiation. In summary, a clinically relevant regimen of fractionated whole-brain irradiation led to significant impairments in spatial learning and reference memory and alterations in the relative levels of subunits of the NMDA, but not the AMPA, receptors in hippocampal CA1. These findings suggest for the first time that radiation-induced cognitive impairments may be associated with alterations in glutamate receptor composition.
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Lesões Encefálicas/metabolismo , Hipocampo/fisiologia , Hipocampo/efeitos da radiação , Transtornos da Memória/etiologia , Transtornos da Memória/metabolismo , Lesões por Radiação/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Animais , Lesões Encefálicas/etiologia , Masculino , Especificidade de Órgãos , Subunidades Proteicas/metabolismo , Doses de Radiação , Lesões por Radiação/etiologia , Ratos , Ratos Endogâmicos F344RESUMO
The aim of this study was to compare physiological effects of hindlimb suspension (HLS) in tail- and pelvic-HLS rat models to determine if severe stretch in the tail-HLS rats lumbosacral skeleton may contribute to the changes traditionally attributed to simulated microgravity and musculoskeletal disuse in the tail-HLS model. Adult male Sprague-Dawley rats divided into suspended and control-nonsuspended groups were subjected to two separate methods of suspension and maintained with regular food and water for 2 weeks. Body weights, food and water consumption, soleus muscle weight, tibial bone mineral density, random plasma insulin, and hindlimb pain on pressure threshold (PPT) were measured. X-ray analysis demonstrated severe lordosis in tail- but not pelvic-HLS animals. However, growth retardation, food consumption, and soleus muscle weight and tibial bone density (decreased relative to control) did not differ between two HLS models. Furthermore, HLS rats developed similar levels of insulinopenia and mechanical hyperalgesia (decreased PPT) in both tail- and pelvic-HLS groups. In the rat-to-rat comparisons, the growth retardation and the decreased PPT observed in HLS-rats was most associated with insulinopenia. In conclusion, these data suggest that HLS results in mild prediabetic state with some signs of pressure hyperalgesia, but lumbosacral skeleton stretch plays little role, if any, in these pathological changes.
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The ADP/ATP Carrier (AAC) is the most abundant transporter of the mitochondrial inner membrane. The central role that this transporter plays in cellular energy production highlights the importance of understanding its structure, function, and the basis of its pathologies. As a means of preparing proteoliposomes for the study of membrane proteins, several groups have explored the use of cell-free translation systems to facilitate membrane protein integration directly into preformed unilamellar vesicles without the use of surfactants. Using AAC as a model, we report for the first time the detergent-free reconstitution of a mitochondrial inner membrane protein into liposomes using a wheat germ-based in vitro translation system. Using a host of independent approaches, we demonstrate the efficient integration of AAC into vesicles with an inner membrane-mimetic lipid composition and, more importantly, that the integrated AAC is functionally active in transport. By adding liposomes at different stages of the translation reaction, we show that this direct integration is obligatorily cotranslational, and by synthesizing stable ribosome-bound nascent chain intermediates, we show that the nascent AAC polypeptide interacts with lipid vesicles while ribosome-bound. Finally, we show that the presence of the phospholipid cardiolipin in the liposomes specifically enhances AAC translation rate as well as the efficiency of vesicle association and integration. In light of these results, the possible mechanisms of liposome-assisted membrane protein integration during cell-free translation are discussed with respect to the mode of integration and the role of specific lipids.