Surfactant protein-S (SP-D) is a naturally occurring lung protein with the potential to treat pulmonary infections. A recombinant surfactant protein-D (SP-D) has been produced and was previously ...found to exist in multiple oligomeric states.
Separation and characterization of interconverting oligomeric states of a protein can be difficult using chromatographic methods, so an alternative separation technique was employed for SPD to characterize the different association states that exist.
Samples of SP-D were analyzed using asymmetrical flow field-flow fractionation (AF4) using UV and multi-angle laser light scattering (MALLS) detection. The AF4 method appears to be able to separate species as small as the monomer up to the dodecamer (the dominant species) to much larger species with a molar mass greater than 5 MDa.
Consistent elution of four distinct peaks was observed after repeated injections. The largest species observed under the last peak (labeled as Peak 4) were termed "unstructured multimers" and were resolved fairly well from the other species. The AF4-MALLS data suggest that only a small fraction of Peak 4 truly corresponds to high molar mass unstructured multimers. All other peaks demonstrated significant molar mass homogeneity consistent with AFM results.
AF4-MALLS technology appears to be a powerful analytical approach to characterize the complex and dynamic interplay among different protein oligomeric species of SP-D in an aqueous solution.
While asymmetrical flow field-flow fractionation (AF4) has been widely used for separation of high molecular weight species and even particles, its ability to resolve lower molecular weight species ...has rarely been explored. Over the course of many projects, we have discovered that AF4 can be an effective analytical method for separating peptides from oligomers and higher molecular weight aggregates. The methodology can be used even for peptides as small as 2 kD in molecular weight. Using multi-angle laser light scattering (MALLS) detection, accurate masses of the parent peptide can be obtained, provided accurate extinction coefficients are provided. It was shown that AF4 can be stability-indicating, suggesting that AF4-MALLS may be a suitable alternative to the use of SEC to monitor the aggregation of peptides.
One challenge of conducting intervention studies is ensuring that study participants are exposed to the intervention. For example, in our randomized controlled trial of Take Charge!, a ...mentor‐implemented and research‐informed violence prevention program that partners with one‐on‐one community‐based mentoring agencies, only 50% of intervention youth with fight‐related injuries were successfully matched with a mentor. We examined the differences between matched (n = 49) and unmatched (n = 49) youth with regard to demographics, time from injury to study enrollment, perceived seriousness of injury, belief that future injury can be avoided, and household chaos. Youth who were successfully matched with a mentor were more likely to perceive the injury as very serious or somewhat serious compared with unmatched youth (95.9% vs. 79.6%, p = .028). All other factors were not significantly associated with successful mentor matching. Future violence prevention interventions should consider youth perceptions as a factor that may influence the completion of desired interventions.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
ABSTRACT
BACKGROUND
Our objective is to describe violence‐related injuries to early adolescents that occurred at school, resulting in emergency department (ED) evaluation.
METHODS
This retrospective ...cohort study at an urban academic pediatric ED in Baltimore, MD, identified patients 10‐15 years old who presented with an injury from intentional, interpersonal violence that occurred at school between January 2019‐December 2020. Descriptive statistics were used to summarize patient and event characteristics.
RESULTS
Of 819 youth 10‐15 years of age evaluated for a violence‐related injury, school was the location in 115 cases (14.0%). All events occurred prior to the statewide stay at home order (March 30, 2020). School‐injured youth had a mean age of 12.7 ± 1.7 years and were predominantly male (64.3%). Of the 115 cases, 75 (65.2%) involved an altercation with a peer, 26 (22.6%) involved a teacher or school staff, 6 (5.2%) involved a family member, 1 (0.9%) involved police, 6 (5.2%) involved an unknown party, and 1 (0.9%) involved an unrelated but known adult. All injured youth were discharged from the ED.
CONCLUSIONS
School‐based violence is a well‐recognized cause of traumatic injuries to adolescents and may involve peers, teachers, or school staff.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK, VSZLJ
Exposure to family violence during childhood and adolescence increases the risk for experiencing or perpetrating future violence. Social distancing protocols combined with reduction in access to ...youth/family services during the COVID-19 pandemic may have intensified the risk of exposure to familial violence.
This study describes the epidemiology of violence-related injuries to 10- to 15-year-old children from family violence, including child maltreatment and physical fighting, resulting in emergency department (ED) evaluation.
This retrospective cohort study located in an urban academic pediatric ED in the mid-Atlantic region is a review of electronic medical records between January 2019 and March 2020 (prepandemic period) and March to December 2020 (pandemic period). This review focused on visits for youth aged 10 to 15 years who presented for evaluation of an injury due to a violent event involving a family member. Demographic and clinical data were abstracted, including circumstances of the event. Descriptive statistics were used to summarize data and compare prepandemic to postpandemic proportions.
Of 819 youth aged 10 to 15 years evaluated for a violence-related injury, 448 (54.7%) involved a family member. Of these, most involved parents/guardians, 343 (76.6%), and occurred at home (83.9%). Most patients were girls (54.0%), Black/African American (84.4%), and were enrolled in a public insurance plan (71.2%). Most youth were transported to the hospital by police (66.7%). Overall, alcohol, drugs, and weapons were involved in 10.0%, 6.5%, and 10.7% of events, respectively, and their involvement significantly increased during the pandemic period to 18.8%, 14.9%, and 23.8% ( P < 0.001). Most patients (98.7%) were discharged from the ED.
More than half of violence-related injuries treated in the ED in this population resulted from family violence. Family violence is a prevalent and possibly underrecognized cause of injuries during adolescence. Further research should explore the potential of the ED as a setting for preventive interventions.
Purpose
To evaluate the different degrees of residual structure in the unfolded state of interferon-τ using chemical denaturation as a function of temperature by both urea and guanidinium ...hydrochloride.
Methods
Asymmetrical flow field-flow fractionation (AF4) using both UV and multi-angle laser light scattering (MALLS). Flow Microscopy. All subvisible particle imaging measurements were made using a FlowCAM flow imaging system.
Results
The two different denaturants provided different estimates of the conformational stability of the protein when extrapolated back to zero denaturant concentration. This suggests that urea and guanidinium hydrochloride (GnHCl) produce different degrees of residual structure in the unfolded state of interferon-τ. The differences were most pronounced at low temperature, suggesting that the residual structure in the denatured state is progressively lost when samples are heated above 25°C. The extent of expansion in the unfolded states was estimated from the m-values and was also measured using AF4. In contrast, the overall size of interferon-τ was determined by AF4 to decrease in the presence of histidine, which is known to bind to the native state, thereby providing conformational stabilization. Addition of histidine as the buffer resulted in formation of fewer subvisible particles over time at 50°C. Finally, the thermal aggregation was monitored using AF4 and the rate constants were found to be comparable to those determined previously by SEC and DLS. The thermal aggregation appears to be consistent with a nucleation-dependent mechanism with a critical nucleus size of 4 ± 1.
Conclusion
Chemical denaturation of interferon-τ by urea or GnHCl produces differing amounts of residual structure in the denatured state, leading to differing estimates of conformational stability. AF4 was used to determine changes in size, both upon ligand binding as well as upon denaturation with GnHCl. Histidine appears to be the preferred buffer for interferon-τ, as shown by slower formation of soluble aggregates and reduced levels of subvisible particles when heated at 50°C.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Drowning is a common mechanism of injury in the pediatric population that often requires hospitalization. The primary objective of this study was to describe the epidemiology and clinical ...characteristics of pediatric drowning patients evaluated in a pediatric emergency department (PED), including the clinical interventions and outcomes of this patient population.
A retrospective cohort study was conducted of pediatric patients evaluated in a mid-Atlantic urban pediatric emergency department from January 2017 to December 2020 after a drowning event.
Eighty patients ages 0–18 were identified, representing 57 79 unintentional events and 1 intentional self-injury event. The majority of patients (50%) were 1–4 years of age. The majority (65%) of patients 4 years of age or younger were White, whereas racial/ethnic minority patients accounted for the majority (73%) of patients 5 years of age or older. Most drowning events (74%) occurred in a pool, on Friday through Saturday (66%) and during the summer (73%). Oxygen was used in 54% of admitted patients and only in 9% of discharged patients. Cardiopulmonary resuscitation (CPR) was performed in 74% of admitted patients and 33% of discharged patients.
Drowning can be an intentional or unintentional source of injury in pediatric patients. Among the patients who presented to the emergency department for drowning, more than half received CPR and/or were admitted, suggesting high acuity and severity of these events. In this study population, outdoor pools, summer season and weekends are potential high yield targets for drowning prevention efforts.
•Drowning is a significant cause of death for children and adolescents•Racial disparities exist in the rates of drowning•Drowning can be a source of intentional or unintentional injury•Drowning patients have a high rate of admission and/or need for cardiopulmonary resuscitation
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Referring facilities often overestimate the total body surface area of burns in comparison to the pediatric burn center.•Such discrepancies may trigger inappropriately aggressive interventions with ...potential for patient harm.•The consistency can be improved by sharing a common clinical assessment tool and standardization of the intake process.
Burns are a significant source of pediatric morbidity and frequently result in transfer of care to a pediatric burn center. Data suggest that referring facilities often overestimate the total body surface area (%TBSA) of burns in comparison to the subsequent assessment at the pediatric burn center. Such discrepancies may trigger inappropriately aggressive interventions with potential for patient harm. Our baseline assessment of data from 106 patients transferred to our pediatric burn center over a one-year period showed that 59/106 (56%) patients had a %TBSA recorded at the time of transfer and 18/59 (31%) had clinically significant differences (>5% difference) in estimates between the referring facility and the pediatric burn center.
Informed by this clinical audit and a root cause analysis, we implemented practices to enhance consistency of clinical assessments between referring facilities and our pediatric burn center. These practices included the use of a common clinical assessment instrument (a standardized Lund and Browder form) that was integrated into the interfacility transfer process as well as educational outreach at referring facilities for providers who treat children with burns, prioritizing facilities with the highest number of discrepancies.
Follow up data was reviewed 16–23 months after initiating the intervention. Cumulatively, we found significant improvement in the proportion of patients with %TBSA recorded (94% vs 56%, p < 0.001) that achieved our goal to exceed 90% and a reduction in clinically significant discrepancies that exceeded our goal of 15% (10% vs 31%, p = 0.002).
Referring facilities often overestimate the %TBSA in comparison to the subsequent assessment at the pediatric burn center. The consistency of the %TBSA estimates can be improved by interventions that utilize the sharing of a common clinical assessment instrument and standardization of the transfer intake process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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