Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 133
Filtrar
1.
J Pediatr Pharmacol Ther ; 29(2): 208, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38596411
2.
Sci Rep ; 14(1): 3765, 2024 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-38355600

RESUMEN

Homozygous Apolipoprotein L1 (APOL1) variants G1 and G2 cause APOL1-mediated kidney disease, purportedly acting as surface cation channels in podocytes. APOL1-G0 exhibits various single nucleotide polymorphisms, most commonly haplotype E150K, M228I and R255K ("KIK"; the Reference Sequence is "EMR"), whereas variants G1 and G2 are mostly found in a single "African" haplotype background ("EIK"). Several labs reported cytotoxicity with risk variants G1 and G2 in KIK or EIK background haplotypes, but used HEK-293 cells and did not verify equal surface expression. To see if haplotype matters in a more relevant cell type, we induced APOL1-G0, G1 and G2 EIK, KIK and EMR at comparable surface levels in immortalized podocytes. G1 and G2 risk variants (but not G0) caused dose-dependent podocyte death within 48h only in their native African EIK haplotype and correlated with K+ conductance (thallium FLIPR). We ruled out differences in localization and trafficking, except for possibly greater surface clustering of cytotoxic haplotypes. APOL1 surface expression was required, since Brefeldin A rescued cytotoxicity; and cytoplasmic isoforms vB3 and vC were not cytotoxic. Thus, APOL1-EIK risk variants kill podocytes in a dose and haplotype-dependent manner (as in HEK-293 cells), whereas unlike in HEK-293 cells the KIK risk variants did not.


Asunto(s)
Podocitos , Humanos , Podocitos/metabolismo , Haplotipos , Apolipoproteína L1/genética , Apolipoproteína L1/metabolismo , Células HEK293 , Variación Genética
3.
J Pediatr Pharmacol Ther ; 28(8): 710-713, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38094678

RESUMEN

OBJECTIVE: Sublingual (SL) buprenorphine is a cornerstone of care in the treatment of adult opioid use disorder. Recent studies have demonstrated its advantages in the management of neonatal opioid withdrawal syndrome (NOWS). Commercially available SL tablets and transdermal patches are not amenable to neonatal use, and published compounding formulas of SL solutions contained undesirable excipients, including ethanol, sugars, and preservatives. The objective of this research is to explore the stability of a novel SL buprenorphine formulation free of alcohol, sugars, and preservatives. METHODS: A 0.075 mg/mL buprenorphine solution was prepared by diluting the commercial injectable solution with normal saline and packaged into polyethylene terephthalate amber prescription bottles and polypropylene amber oral syringes and stored in refrigeration. Quality assessments were conducted by visual, pH, and high-performance liquid chromatography (HPLC) analysis immediately after preparation, and at 7 and 14 days of storage. RESULTS: There were neither visual nor pH changes detected through 14 days. HPLC analysis indicated that all samples retained >99% initial buprenorphine concentration. Drug concentration increased slightly in the oral syringe after day 7, probably due to moisture loss. No degradation peaks were observed in chromatograms. CONCLUSIONS: This novel buprenorphine is free of alcohol, sugar, and preservatives, and it may offer a significant safety advantage for NOWS patients. Additional clinical studies are recommended to verify the bioavailability and efficacy of this formulation.

4.
Rev Sci Instrum ; 94(6)2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37862514

RESUMEN

We report on the design, construction, and testing of a high-speed rotor intended for use in hypervelocity microparticle impact studies. The rotor is based on a four-wing design to provide rotational stability and includes flat "paddle" impact surfaces of ∼0.5 cm2 at the tips of each wing. The profile of each wing minimizes the variation in tensile forces at any given rotational speed. The rotor was machined using titanium (grade 5) and operated in high vacuum using magnetically levitated bearings. Initial experiments were run at several speeds up to 100 000 rpm (revolutions per minute), corresponding to a tip speed of 670 m/s. Elongation at the wing tips as a function of rotational speed was measured with a precision of several micrometers using a focused diode laser and found to agree with an elastic modulus of 1.16 GPa for the rotor material. Applications to microparticle impact experiments are discussed.

5.
Rev Sci Instrum ; 94(3): 034104, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37012798

RESUMEN

This paper outlines the use of charge detection mass spectrometry to simultaneously measure the charge and mass of micron-sized particles. In a flow-through instrument, the detection of charge was achieved through charge induction onto cylindrical electrodes that connect to a differential amplifier. Mass was determined by particle acceleration under the influence of an electric field. Particles ranging from 30 to 400 fg (3 to 7 µm diameter) were tested. The detector design can measure particle mass within 10% accuracy for particles up to 620 fg with total charge ranging from 500e- to 56 ke-. This charge and mass range are expected to be relevant for dust on Mars.

6.
JSES Int ; 7(1): 30-34, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36820413

RESUMEN

Background: We aimed to evaluate midterm patient-reported outcomes and reoperation rates following rotator cuff repair in patients with either rheumatoid arthritis (RA) or other inflammatory arthritis (nonRA-IA) diagnoses. Methods: We identified all patients with either RA or nonRA-IA who underwent a rotator cuff repair at our institution between 2008 and 2018. IA diagnoses included RA, systemic lupus erythematosus, psoriatic arthritis, and other unspecified inflammatory arthritis. We compiled a cohort of 51 shoulders, with an average follow-up time of 7.0 years. The average age was 60 years (range 39-81), and 55% of patients were female. Patients were contacted via phone to obtain patient-reported outcomes surveys. Univariate linear regression was used to evaluate associations between patient characteristics and outcomes. Results: A review of preoperative radiographs demonstrated that 50% of patients presented with some degree of glenohumeral joint inflammatory degeneration. At the final follow-up, the mean visual analog score for pain was 2 (range 0-8), and the mean American Shoulder and Elbow Surgeons score (ASES) was 77 (standard deviation [SD] = 19). The mean subjective shoulder value was 75% (SD = 22%), and the average satisfaction was 9 (SD 1.9). The mean Patient-Reported Outcomes Measurement Information System upper extremity score was 41 (SD = 10.6). Female sex and a complete tear (vs. partial) were both associated with lower ASES scores, whereas no other characteristics were associated with postoperative ASES scores. The 5-year Kaplan-Meier survival estimate free of reoperation was 91.8% (95% confidence interval 83.0-99.8). Conclusions: Rotator cuff repair in patients with RA or other inflammatory arthritis diagnoses resulted in satisfactory patient-reported outcomes that seem comparable to rotator cuff repair when performed in the general population. Furthermore, reoperations were rare, with a 5-year survival rate free of reoperation for any reason of over 90%. Altogether, an inflammatory arthritis diagnosis should not preclude by itself attempted rotator cuff repair surgery in these patients.

7.
ACS Pharmacol Transl Sci ; 6(1): 88-91, 2023 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-36654755

RESUMEN

Cephalosporins are a widely used subclass of ß-lactam antibiotics that demonstrate variable protein binding independent of generation or antibiotic coverage. Prior work analyzed carbon 3 (C3) and carbon 7 (C7) substituents (locations of R2 and R1 groups respectively) for protein binding interactions. This study builds upon these results with statistical analysis of additional agents of the class. Chemical structures of 23 cephalosporins were used to identify the presence of 40 functional groups, and correlative relationships were identified using established protein binding data. Four functional groups were significantly correlated with protein binding: tetrazole (positive association), pyridinium, primary amine, and quaternary amine (negative associations). Cephalosporins with a negative charge at physiological pH were associated with increased protein binding. Analysis of tetrazole-containing cephalosporins and ceftriaxone indicates the need for further study of the potential role in protein binding of neutral or negatively charged aromatic nitrogen heterocycles linked at the C3 position by a thiomethylene group.

8.
Am J Sports Med ; 51(2): 351-357, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36541470

RESUMEN

BACKGROUND: Arthroscopic debridement for osteochondritis dissecans (OCD) lesions of the capitellum is a relatively common and straightforward surgical option for failure of nonoperative management. However, the long-term outcomes of this procedure remain unknown. HYPOTHESIS: Arthroscopic debridement of capitellar OCD would provide satisfactory long-term improvement in patient-reported outcomes. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients aged ≤18 years who underwent arthroscopic debridement procedures for OCD lesions (International Cartilage Repair Society grades 3 and 4) were identified. Procedures included loose body removal when needed and direct debridement of the lesion; marrow stimulation with drilling or microfracture was added at the discretion of each surgeon. The cohort consisted of 53 elbows. Patient evaluation included visual analog scale for pain; motion; subjective satisfaction; Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores; reoperation; and rate of return to sports. RESULTS: At a mean 11 years of follow-up (range, 5-23 years), the median visual analog scale score for pain was 0, and 96% of patients reported being improved as compared with how they were before surgery. The mean ± SD QuickDASH score was 4 ± 9 points (range, 0-52 points), and 80% of patients returned to their sports of interest. The arc of motion significantly improved from 115°± 28° preoperatively to 130°± 17° at latest follow-up (P = .026). Seven elbows (13%) required revision surgery for OCD lesions, resulting in high rates of overall survivorship free of revision surgery: 90% (95% CI, 80%-96%) at 5 years and 88% (95% CI, 76%-94%) at 10 years. At final follow-up, 7 all-cause reoperations were performed without revision surgery on the OCD lesion. CONCLUSION: Arthroscopic debridement of grade 3 or 4 OCD lesions of the capitellum produced satisfactory patient-reported outcomes in a majority of elbows, although a subset of patients experienced residual symptoms. The inherent selection bias of our cohort should be considered when applying these results to the overall population with OCD lesions, as we do not recommend this procedure for all patients.


Asunto(s)
Articulación del Codo , Osteocondritis Disecante , Humanos , Resultado del Tratamiento , Desbridamiento/métodos , Osteocondritis Disecante/cirugía , Artroscopía/métodos , Articulación del Codo/cirugía , Dolor
9.
Mol Imaging Biol ; 25(1): 46-57, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36447084

RESUMEN

Fluorescence-guided surgery (FGS) is an evolving field that seeks to identify important anatomic structures or physiologic phenomena with helpful relevance to the execution of surgical procedures. Fluorescence labeling occurs generally via the administration of fluorescent reporters that may be molecularly targeted, enzyme-activated, or untargeted, vascular probes. Fluorescence guidance has substantially changed care strategies in numerous surgical fields; however, investigation and adoption in orthopaedic surgery have lagged. FGS shows the potential for improving patient care in orthopaedics via several applications including disease diagnosis, perfusion-based tissue healing capacity assessment, infection/tumor eradication, and anatomic structure identification. This review highlights current and future applications of fluorescence guidance in orthopaedics and identifies key challenges to translation and potential solutions.


Asunto(s)
Neoplasias , Procedimientos Ortopédicos , Ortopedia , Cirugía Asistida por Computador , Humanos , Fluorescencia , Imagen Óptica/métodos , Cirugía Asistida por Computador/métodos , Colorantes Fluorescentes
10.
J Shoulder Elbow Surg ; 31(12): 2506-2513, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36115618

RESUMEN

BACKGROUND: Radial head arthroplasty (RHA) is an important tool in the acute treatment of comminuted radial head and neck fractures. RHA is also performed in a delayed manner after failed open reduction and internal fixation, for fracture malunion or nonunion, and other chronic post-traumatic elbow disorders where restoration of the lateral column of the elbow is considered necessary. The relative efficacy and longevity of acute vs. delayed RHA is unknown. We sought to compare clinical, radiographic, and patient-reported outcomes between these groups. METHODS: We identified patients ≥18 years old who underwent an RHA between 2000 and 2018 and then extracted 135 total elbows with a mean follow-up of 2.3 years that sustained isolated radial head fractures (30%), terrible triad injuries (66%), or Essex-Lopresti injuries (4%). The acute cohort (RHA: <12 weeks) contained 101 elbows that underwent surgery at a mean of 0.6 weeks (range, 0 days to 7 weeks, 96% <2 weeks) from injury, whereas the delayed cohort (RHA: 12 weeks to 2 years) contained 34 elbows that underwent surgery at a mean of 36 weeks (range, 14-82 weeks) from injury. Patients in the acute group had a higher percentage of terrible triad injuries (75% vs. 40%, P < .001) and Mason 3 fractures (98% vs. 45%, P < .001). RESULTS: At the final follow-up, 13 of 101 patients in the acute cohort (13%) and 7 of 34 patients in the delayed cohort (21%) required implant revision or resection. A total of 25 patients (25%) in the acute cohort and 12 patients (35%) in the delayed cohort required a reoperation. Kaplan-Meier 2-year survival estimates free of implant resection or revision (90% acute, 86% delayed) and reoperation (76% acute, 70% delayed) were similar between groups. In patients with 5-year follow-up, there was an increased rate of revision or resection in the delayed group (30% vs. 13%). Two-year survival estimates free of radiographic loosening were 80% in the acute cohort vs. 57% in the delayed cohort (P = .04). Mayo Elbow Performance Score at 2 years demonstrated mean scores of 83 and 79 in the acute and delayed groups, respectively, with 71% of the acute cohort and 64% of the delayed cohort achieving good or excellent scores. CONCLUSIONS: Our results demonstrated that although 2-year Kaplan-Meier survival free of revision or resection estimates and reoperation rates was equivalent between the groups, the delayed group experienced worse Mayo Elbow Performance Score outcomes, a higher revision or resection rate at 5 years, and an increased rate of radiographic loosening.


Asunto(s)
Lesiones de Codo , Articulación del Codo , Fracturas del Radio , Humanos , Adolescente , Rango del Movimiento Articular , Estudios Retrospectivos , Resultado del Tratamiento , Fracturas del Radio/diagnóstico por imagen , Fracturas del Radio/cirugía , Articulación del Codo/diagnóstico por imagen , Articulación del Codo/cirugía , Artroplastia/métodos
11.
J Clin Transl Sci ; 6(1): e43, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35651960

RESUMEN

Background: Chemical structure is a vital consideration early in the drug development process. Its role in analysis of safety and efficacy is relatively diminished after drugs are approved for clinical use. This interdisciplinary study explores a strategy by which readily available clinical data may be used along with structural features of drugs to identify associations with potential utility for both clinical decision-making and drug development. Methods: Chemical functional groups and structural groups (SGs) of 261 drugs were manually classified in tiers, and their incidence of gastrointestinal (GI) and central nervous system (CNS) adverse drug reactions (ADRs) were obtained from a clinical database. Drugs with an GI or CNS ADR incidence of at least 10% were analyzed for correlations with their functional and SGs. Results: Eight statistically significant associations were detected by preliminary analysis: piperazine and methylene groups were associated with higher rate of CNS ADRs; while amides, secondary alcohols, and di-substituted phenyl groups were associated with lower rates of GI or CNS ADRs or both. Conclusions: Although further study is necessary to understand these associations and build upon this strategy, this exploratory analysis establishes a methodology by which chemical properties of drugs may be used to aid in clinical decision-making when choosing between otherwise equivalent drug therapy options, as the presence of specific groups on drugs may be associated with increased or decreased risks of specific ADRs.

12.
JSES Int ; 6(3): 406-412, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35572450

RESUMEN

Background: While the effect of clopidogrel on outcomes in elective hip and knee arthroplasty has been well described, there is a paucity of data regarding elective shoulder arthroplasty. Methods: Fifty-eight patients were identified who underwent primary anatomic total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty while prescribed clopidogrel. There were 33 (57%) reverse shoulder arthroplasties and 25 (43%) TSAs performed. Patients were separated into two groups based upon their use of clopidogrel in the preoperative period. Twenty patients (35%; group 1) continued clopidogrel through surgery, and 38 patients (65%; group 2) did not. The mean age was 74 years, and the mean follow-up was 42 months. Results: Both groups demonstrated substantial improvements in pain and motion: visual analog scale pain improved by 7 points (P < .001), elevation by 71° (P < .001), external rotation by 29° (P < .001), and internal rotation by 1.7 points (P < .001), with no significant difference between groups. At the final follow-up, the mean American Shoulder and Elbow Surgeons score was 77 in group 1 and 86 in group 2 (P = .067, minimum clinically important difference = 9). Estimated blood loss was 176 mL in group 1 and 127 in group 2 (P = .02). There was one transfusion in group 1 (5%) and 0 in group 2 (P = .16). The 90-day complication rates were 3/20 (15%) in group 1 and 0/37 in group 2 (hazard ratio = 13, P = .14). There was no statistically significant difference between groups for 30-day adverse cardiac events (2.6% and 0%, respectively, P = .46). Conclusion: For the patients who continued clopidogrel preoperatively, estimated blood loss was significantly higher and trended toward a lower American Shoulder and Elbow Surgeons score (with differences meeting the minimum clinically important difference) and a higher 90-day complication rate. Perioperative continuation of clopidogrel in shoulder arthroplasty should be approached cautiously.

13.
J Shoulder Elbow Surg ; 31(10): 1993-2000, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35483567

RESUMEN

BACKGROUND: The location (proximal vs. distal) of elbow medial ulnar collateral ligament (MUCL) tears impacts clinical outcomes of nonoperative treatment. The purposes of our study were to (1) determine whether selective releases of the MUCL could be performed under ultrasound (US) guidance without disrupting overlying soft tissues, (2) assess the difference in medial elbow stability for proximal and distal releases of the MUCL using stress US and a robotic testing device, and (3) elucidate the flexion angle that resulted in the greatest amount of medial elbow laxity after MUCL injury. METHODS: Sixteen paired, fresh-frozen elbow specimens were used. Valgus laxity was evaluated with both US and robotic-assisted measurements before and after selective MUCL releases. A percutaneous US-guided technique was used to perform proximal MUCL releases in 8 elbows and to perform distal MUCL releases in their matched pairs. The robot was used to determine the elbow flexion angle at which the maximum valgus displacement occurred for both proximally and distally released specimens. Open dissection was then performed to assess the accuracy of the percutaneous releases. RESULTS: Percutaneous US-guided releases were successfully performed in 15 of 16 specimens. The proximal release resulted in greater valgus angle displacement (11° ± 2°) than the distal release (8° ± 2°) between flexion angles of 30° and 70° (P < .0001 at 30°, P < .0001 at 40°, P = .001 at 50°, P = .005 at 60°, and P = .020 at 70°). Valgus displacement between release locations did not reach the level of statistical significance between 80° and 120° (P = .051 at 80°, P = .131 at 90°, P = .245 at 100°, P = .400 at 110°, and P = .532 at 120°). When we compared the values for the mean increase in US delta gap (stressed - supported state) from before to after MUCL release, the proximally released elbows had larger increases than the distally released elbows (5.0 mm proximal vs. 3.7 mm distal, P = .032). After MUCL release, maximum mean valgus displacement occurred at 49° of flexion. CONCLUSIONS: US-guided selective releases of the MUCL can be performed reliably without violating the overlying musculature. Valgus instability is not of greater magnitude for distal releases when compared with proximal releases. This findings suggests there must be alternative factors to explain the difference in clinical prognosis between distal and proximal tears. The observed flexion angle for maximum valgus laxity could have important implications for elbow positioning during US or fluoroscopic stress examination, as well as surgical repair or reconstruction of the MUCL.


Asunto(s)
Ligamento Colateral Cubital , Ligamentos Colaterales , Articulación del Codo , Inestabilidad de la Articulación , Robótica , Fenómenos Biomecánicos , Cadáver , Ligamento Colateral Cubital/diagnóstico por imagen , Ligamento Colateral Cubital/lesiones , Ligamento Colateral Cubital/cirugía , Ligamentos Colaterales/cirugía , Codo/cirugía , Articulación del Codo/cirugía , Humanos , Inestabilidad de la Articulación/diagnóstico por imagen , Inestabilidad de la Articulación/cirugía , Ultrasonografía Intervencional
14.
Artículo en Inglés | MEDLINE | ID: mdl-35224410

RESUMEN

BACKGROUND: Periprosthetic joint infection (PJI) can be a devastating complication following shoulder arthroplasty. PJI following hip and knee arthroplasties has been found to increase mortality. However, anatomical and bacteriologic differences could potentially result in a different trend after shoulder arthroplasties. Thus, the purpose of the present study was to determine whether there is an association between shoulder PJI and all-cause mortality. METHODS: Our institutional Total Joint Registry Database was queried to identify patients who underwent revision shoulder arthroplasty procedures between 2000 and 2018. A total of 1,160 procedures were then classified as either septic (21.8%) or aseptic (78.2%). Septic revisions were further subdivided into (1) debridement, antibiotics, irrigation, and implant retention (9.1%); (2) 2-stage reimplantation for deep infection (61.3%); (3) implant resection without reimplantation (3.6%); and (4) unexpected positive cultures at revision surgery (26.1%). The most common bacterium isolated was Cutibacterium acnes (64.4%). All-cause patient mortality was determined with use of our registry and confirmed with use of a nationwide mortality database. All-cause crude and adjusted mortality rates were then compared between groups. RESULTS: The 1-year crude mortality rate was 1.8% (95% confidence interval [CI], 0.9% to 2.6%) for the aseptic group and 2.8% (95% CI, 0.7% to 4.8%) for the septic group (p = 0.31). Multivariate Cox regression analysis demonstrated an elevated but statistically similar adjusted hazard ratio for 1-year all-cause mortality of 1.9 (95% CI, 0.8 to 4.6) when comparing the septic to the aseptic group (p = 0.17). The risk of 2-year all-cause mortality was significantly higher in the septic group, with a hazard ratio of 2.2 (95% CI, 1.1 to 4.5; p = 0.029). In univariate analyses, increased 5-year mortality in the septic revision group was associated with age, Charlson Comorbidity Index, and methicillin-resistant Staphylococcus aureus infection, whereas C. acnes infection was associated with lower mortality. CONCLUSIONS: Shoulder PJI is associated with an adjusted 2-year all-cause mortality rate that is double that of aseptic patients. The results of the present study should be utilized to appropriately counsel patients who are considered to be at risk for infection following shoulder arthroplasty. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

15.
J Cardiothorac Vasc Anesth ; 36(5): 1343-1349, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35065876

RESUMEN

OBJECTIVES: To examine the use of inhaled nitric oxide (iNO) and inhaled epoprostenol (iPGI2) before and after implementation of an iPGI2-preferential protocol and the associated cost differences after rollout. DESIGN: A single-center, retrospective analysis. SETTING: A quaternary university hospital. PARTICIPANTS: All patients admitted to the Heart Center Intensive Care Unit (HCICU) who required inhaled pulmonary vasodilator use between December 2017 and November 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The HCICU comprised 84% of hospital-wide iNO utilization and 59% of hospital-wide iPGI2 use across the entire study period. There was no significant difference in postsurgical HCICU admission rates across the study period. There was a significant decrease in iNO mean monthly use from 578 ± 230 to 69 ± 71 hours, and a significant concurrent increase in iPGI2 from 756 ± 443 to 1,210 ± 547 hours after the implementation of a protocol. There were no changes in the average length of ICU stay between the 2 time periods. The protocol implementation led to a projected annual savings of roughly $1,180,000. CONCLUSIONS: These findings showed that multidisciplinary protocol development and implementation can have a substantial impact on medication utilization and lead to significant reductions in cost.


Asunto(s)
Epoprostenol , Vasodilatadores , Administración por Inhalación , Humanos , Unidades de Cuidados Intensivos , Óxido Nítrico , Estudios Retrospectivos
16.
Proc Biol Sci ; 288(1963): 20212029, 2021 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-34814749

RESUMEN

Avoiding detection through camouflage is often key to survival. However, an animal's appearance is not the only factor affecting conspicuousness: background complexity also alters detectability. This has been experimentally demonstrated for both artificially patterned backgrounds in the laboratory and natural backgrounds in the wild, but only for targets that already match the background well. Do habitats of high visual complexity provide concealment to even relatively poorly camouflaged animals? Using artificial prey which differed in their degrees of background matching to tree bark, we were able to determine their survival, under bird predation, with respect to the natural complexity of the background. The latter was quantified using low-level vision metrics of feature congestion (or 'visual clutter') adapted for bird vision. Higher background orientation clutter (edges with varying orientation) reduced the detectability of all but the poorest background-matching camouflaged treatments; higher background luminance clutter (varying achromatic lightness) reduced average mortality for all treatments. Our results suggest that poorer camouflage can be mitigated by more complex backgrounds, with implications for both camouflage evolution and habitat preferences.


Asunto(s)
Pigmentación , Conducta Predatoria , Animales , Aves , Ecosistema , Visión Ocular
17.
Am J Health Syst Pharm ; 78(21): 1952-1961, 2021 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-33993212

RESUMEN

PURPOSE: Preliminary reports suggest that critically ill patients with coronavirus disease 2019 (COVID-19) infection requiring mechanical ventilation may have markedly increased sedation needs compared with critically ill, mechanically ventilated patients without COVID-19. We conducted a study to examine sedative use for this patient population within multiple intensive care units (ICUs) of a large academic medical center. METHODS: A retrospective, single-center cohort study of sedation practices for critically ill patients with COVID-19 during the first 10 days of mechanical ventilation was conducted in 8 ICUs at Massachusetts General Hospital, Boston, MA. The study population was a sequential cohort of 86 critically ill, mechanically ventilated patients with COVID-19. Data characterizing the sedative medications, doses, drug combinations, and duration of administration were collected daily and compared to published recommendations for sedation of critically ill patients without COVID-19. The associations between drug doses, number of drugs administered, baseline patient characteristics, and inflammatory markers were investigated. RESULTS: Among the study cohort, propofol and hydromorphone were the most common initial drug combination, with these medications being used on a given day in up to 100% and 88% of patients, respectively. The doses of sedative and analgesic infusions increased for patients over the first 10 days, reaching or exceeding the upper limits of published dosage guidelines for propofol (48% of patients), dexmedetomidine (29%), midazolam (7.7%), ketamine (32%), and hydromorphone (38%). The number of sedative and analgesic agents simultaneously administered increased over time for each patient, with more than 50% of patients requiring 3 or more agents by day 2. Compared with patients requiring 3 or fewer agents, patients requiring more than 3 agents were of younger age, had an increased body mass index, had increased serum ferritin and lactate dehydrogenase concentrations, had a lower Pao2:Fio2 (ratio of arterial partial pressure of oxygen to fraction of inspired oxygen), and were more likely to receive neuromuscular blockade. CONCLUSION: Our study confirmed the clinical impression of elevated sedative use in critically ill, mechanically ventilated patients with COVID-19 relative to guideline-recommended sedation practices in other critically ill populations.


Asunto(s)
COVID-19 , Enfermedad Crítica , Estudios de Cohortes , Humanos , Hipnóticos y Sedantes , Unidades de Cuidados Intensivos , Respiración Artificial , Estudios Retrospectivos , SARS-CoV-2
18.
J Am Acad Orthop Surg ; 29(14): 616-623, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33156213

RESUMEN

INTRODUCTION: Applying to orthopaedic surgery residency is competitive. Online information and mentorship are important tools applicants use to learn about programs and navigate the process. We aimed to identify which resources applicants use and their perspectives on those resources. METHODS: We surveyed all applicants at a single residency program for the 2018 to 2019 application cycle (n = 610) regarding the importance of online resources and mentors during the application process. We defined mentorship as advice from faculty advisors or counselors, orthopaedic residents, medical school alumni, or other medical students. We also assessed their attitudes about the quality and availability of these resources. Applicants were asked to rank resources and complete Likert scales (1 to 5) to indicate the relative utility and quality of options. Descriptive statistics were used to summarize data for comparisons. RESULTS: The response rate was 42% (259 of 610 applicants). Almost 50% of applicants reported that they would have likely applied to fewer programs if they had better information. Applicants used program websites with the highest cumulative frequency (96%), followed by advice from medical school faculty/counselors and advice from orthopaedic residents at home institution (both 82%). The next two most popular online resources were a circulating Google Document (78%) and the Doximity Residency Navigator (73%). On average, the quality of online resources was felt to be poorer than mentorship with advice from orthopaedic residents receiving the highest quality rating (4.16) and being ranked most frequently as a top three resource (122 votes). Mentorship comprised three of the top five highest mean quality ratings and three of the top five cumulative rankings by usefulness. CONCLUSION: Applicants reference online resources frequently, despite valuing mentorship more. If the orthopaedic community fostered better mentorship for applicants, they may not feel compelled to rely on subpar online information. Both online information and mentorship can be improved to create a more effective application experience.


Asunto(s)
Internado y Residencia , Procedimientos Ortopédicos , Ortopedia , Docentes Médicos , Humanos , Mentores , Ortopedia/educación
20.
Chest ; 159(3): 1155-1165, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32971075

RESUMEN

Emergency airway management (EAM) is associated with a high rate of complications, morbidity, and mortality. Handheld point-of-care ultrasound shows promise as an emerging technology to facilitate rapid screening for difficult laryngoscopy, identify the cricothyroid membrane for potential cricothyroidotomy, and assess for increased aspiration risk, as well as provide confirmation of proper endotracheal tube positioning. This review summarizes the available evidence for the use of point-of-care ultrasound in EAM, provides an algorithm to facilitate its incorporation into existing EAM practice to improve patient safety, and serves as a framework for future validation studies.


Asunto(s)
Manejo de la Vía Aérea , Servicios Médicos de Urgencia/métodos , Sistemas de Atención de Punto , Ultrasonografía , Manejo de la Vía Aérea/instrumentación , Manejo de la Vía Aérea/métodos , Humanos , Ultrasonografía/instrumentación , Ultrasonografía/métodos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...