Spacecraft sample collection and subsurface excavation of asteroid (101955) Bennu.

Carbonaceous asteroids, such as (101955) Bennu, preserve material from the early Solar System, including volatile compounds and organic molecules. We report spacecraft imaging and spectral data collected during and after retrieval of a sample from Bennu's surface. The sampling event mobilized rocks and dust into a debris plume, excavating a 9-meter-long elliptical crater. This exposed material is darker, spectrally redder, and more abundant in fine particulates than the original surface. The bulk density of the displaced subsurface material was 500 to 700 kilograms per cubic meter, which is about half that of the whole asteroid. Particulates that landed on instrument optics spectrally resemble aqueously altered carbonaceous meteorites. The spacecraft stored 250 ± 101 grams of material, which will be delivered to Earth in 2023.

Initial Orbit Determination and Event Reconstruction From Estimation of Particle Trajectories About (101955) Bennu.

The OSIRIS-REx mission has observed multiple instances of particles being ejected from the surface of near-Earth asteroid (101955) Bennu. The ability to quickly identify the particle trajectories and origins is necessary following a particle ejection event. Using proven initial orbit determination techniques, we can rapidly estimate particle trajectories and ejection locations. We present current results pertaining to the identification of particle tracks, an evaluation of the estimated orbits and the excess velocity necessary to induce the particle ejection from the surface, and the uncertainty quantification of the ejection location. We estimate energies per particle ranging from 0.03 to 11.03 mJ for the largest analyzed events and velocities ranging from 5 to 90 cm/s, though we exclude the highest-velocity particles in this technique. We estimate ejection times for eight events and constrain six of the analyzed ejection events to have occurred between about 16:30 and 19:00 local solar time, with the largest events occurring between 16:30 and 18:05.

Episodes of particle ejection from the surface of the active asteroid (101955) Bennu.

Active asteroids are those that show evidence of ongoing mass loss. We report repeated instances of particle ejection from the surface of (101955) Bennu, demonstrating that it is an active asteroid. The ejection events were imaged by the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) spacecraft. For the three largest observed events, we estimated the ejected particle velocities and sizes, event times, source regions, and energies. We also determined the trajectories and photometric properties of several gravitationally bound particles that orbited temporarily in the Bennu environment. We consider multiple hypotheses for the mechanisms that lead to particle ejection for the largest events, including rotational disruption, electrostatic lofting, ice sublimation, phyllosilicate dehydration, meteoroid impacts, thermal stress fracturing, and secondary impacts.

Risk factors for community-associated Clostridioides difficile infection in young children.

The majority of paediatric Clostridioides difficile infections (CDI) are community-associated (CA), but few data exist regarding associated risk factors. We conducted a case-control study to evaluate CA-CDI risk factors in young children. Participants were enrolled from eight US sites during October 2014-February 2016. Case-patients were defined as children aged 1-5 years with a positive C. difficile specimen collected as an outpatient or ⩽3 days of hospital admission, who had no healthcare facility admission in the prior 12 weeks and no history of CDI. Each case-patient was matched to one control. Caregivers were interviewed regarding relevant exposures. Multivariable conditional logistic regression was performed. Of 68 pairs, 44.1% were female. More case-patients than controls had a comorbidity (33.3% vs. 12.1%; P = 0.01); recent higher-risk outpatient exposures (34.9% vs. 17.7%; P = 0.03); recent antibiotic use (54.4% vs. 19.4%; P < 0.0001); or recent exposure to a household member with diarrhoea (41.3% vs. 21.5%; P = 0.04). In multivariable analysis, antibiotic exposure in the preceding 12 weeks was significantly associated with CA-CDI (adjusted matched odds ratio, 6.25; 95% CI 2.18-17.96). Improved antibiotic prescribing might reduce CA-CDI in this population. Further evaluation of the potential role of outpatient healthcare and household exposures in C. difficile transmission is needed.

Heat-induced changes in intracellular Na+, pH and bioenergetic status in superfused RIF-1 tumour cells determined by 23Na and 31P magnetic resonance spectroscopy.

The acute effects of hyperthermia on intracellular Na+ (Nai+), bioenergetic status and intracellular pH (pHi) were investigated in superfused Radiation Induced Fibrosarcoma-1 (RIF-1) tumour cells using shift-reagent-aided 23Na and 31P nuclear magnetic resonance (NMR) spectroscopy. Hyperthermia at 45 degrees C for 30 min produced a 50% increase in Na, a 0.42 unit decrease in pHi and a 40-45% decrease in NTP/P(i). During post-hyperthermia superfusion at 37 degrees C, pHi and NTP/P(i) recovered to the baseline value, but Na initially decreased and then increased to the hyperthermic level 60 min after heating. Hyperthermia at 42 degrees C caused only a 15-20% increase in Nai+. In the presence of 3 microM 5-(N-ethyl-N-isopropyl)amiloride (EIPA), an inhibitor of the Na+/H+ exchanger, the increase in Nai+ during 45 degrees C hyperthermia was attenuated, suggesting that the heat-induced increase in Nai+ was mainly due to an increase in Na+/H+ anti-porter activity. EIPA did not prevent hyperthermia-induced acidification. This suggests that pHi is controlled by other ion exchange mechanisms in addition to the Na+/H+ exchanger. EIPA increased the thermo-sensitivity of the RIF-1 tumour cells only slightly as measured by cell viability and clonogenic assays. The hyperthermia-induced irreversible increase in Nai+ suggests that changes in transmembrane ion gradients play an important role in cell damage induced by hyperthermia.

Effects of hyperglycemia on oxygenation, radiosensitivity and bioenergetic status of subcutaneous RIF-1 tumors.

Since tissue oxygen tension is a balance between delivery and consumption of oxygen, considerable effort has been directed at increasing the former and/or decreasing the latter. Techniques to decrease the rate of cellular oxygen consumption (increasing the distance oxygen can diffuse into tissues) include increasing glycolysis by administering supra-physiologic levels of glucose. We have examined the effect of hyperglycemia produced by intravenous glucose infusion on the tissue oxygenation and radiation response of subcutaneously implanted murine radiation induced fibrosarcomas (RIF-1). A 0.3 M glucose solution was delivered via tail vein injection according to a protocol that maintained glucose at a plasma concentration of 17+/-1 mM. The effect of this treatment on radiation response (clonogenic and growth delay studies), tumor oxygenation (needle electrode pO2 and 2-[2-nitro-1H-imidazol-1-yl]-N-(2,2,3,3,3-pentafluoropropyl) acetamide (EF5) binding), and tumor bioenergetics and pH (31P NMR spectroscopy) was examined. Systemic measurements included hematocrit and blood glucose and lactate concentrations. The results of these studies suggest that these subcutaneously implanted RIF-1 tumors are both radiobiologically and metabolically hypoxic and that intravenous glucose infusion is not an effective method of modifying this metabolic state.

A prospective evaluation of the clinical presentation of pediatric pelvic fractures.

BACKGROUND: We sought to describe pediatric, blunt trauma patients with pelvic fracture (PF) and to evaluate pelvis examination sensitivity and specificity. METHODS: We conducted a prospective study of blunt trauma patients at a Level I pediatric trauma center. A pediatric emergency medicine physician attempted to diagnose a PF, solely on the basis of the history and pelvis examination. Patients with blunt trauma but no pelvic fracture (NPF) were used as controls. RESULTS: We enrolled 140 patients (16 PF, 124 NPF), and no significant differences were found regarding median age, gender, injury mechanism, acuity, and medical outcome. Approximately 25% of PF patients had iliac-wing fractures; 37%, single pelvic ring; 25%, double pelvic ring; and 13%, acetabular fractures. Eleven patients with PF had an abnormal pelvis examination (69% sensitivity), compared with six NPF patients (95% specificity, negative predictive value 0.91). CONCLUSION: Pediatric patients with PF have low mortality and few complex fractures. The pelvis examination appears to have both high specificity and negative predictive value.

Do parents choose appropriate automotive restraint devices for their children?

This study aims to describe parental choices of childhood automotive restraints and compare them with guidelines based on weight and height. Parents were surveyed and their children's heights and weight were measured. Results indicated that many parents believed their child fit a lap or shoulder belt when their children were too short to fit these devices. For children weighing < 40 pounds, 45% of parents believed the lap belt fit. Thirteen percent of 4-7-year-olds used booster seats, appropriate for 72% by sitting height criteria; and 33% of children < or = 7 years used the lap/shoullder belt, appropriate for 8% by sitting height criteria. Implications are that parental perceptions of fit may lead to inappropriate restraint choices for children. Practitioners should discuss child restraint use with parents in the context of their child's weight and height.

The addition of ceftriaxone to oral therapy does not improve outcome in febrile children with urinary tract infections.

OBJECTIVE: To determine whether the addition of a single dose of ceftriaxone sodium to a 10-day course of trimethoprim and sulfamethoxazole hastens urine sterilization or resolution of clinical symptoms in febrile children with urinary tract infections. DESIGN: Prospective, single-blind, randomized study. SETTING: Tertiary care children's hospital emergency department. PATIENTS: Febrile children aged 6 months to 12 years with a presumptive urinary tract infection based on history, physical examination, and urinalysis findings. INTERVENTIONS: A history was taken, a physical examination and urinalysis and culture were performed, and a white blood cell count and erythrocyte sedimentation rate were obtained. Children were randomized to receive an intramuscular dose of ceftriaxone then 10 days of trimethoprim-sulfamethoxazole (IM + PO group) or oral trimethoprim-sulfamethoxazole alone (PO group). After receiving study medication, patients were discharged from the hospital to return in 48 hours for a follow-up evaluation and urine culture. Treatment failure was defined as the persistence of a positive culture at 48 hours or the need for hospital admission for intravenous rehydration or antibiotic therapy. RESULTS: Sixty-nine children were enrolled, 34 in the IM + PO group and 35 in the PO group. The 2 groups were similar at the initial visit with respect to age, sex, clinical degrees of illness, white blood cell count, and erythrocyte sedimentation rate (P>.05). At the 48-hour follow-up visit, there were no differences between the 2 treatment groups in resolution of vomiting, fever, general appearance, abdominal tenderness, and hydration state (P>.05). There were 9 treatment failures, 4 in the IM + PO group and 5 in the PO group (P =.93). CONCLUSION: The addition of a single dose of intramuscular ceftriaxone to a 10-day course of oral trimethoprim-sulfamethoxazole for urinary tract infection with fever resulted in no difference at 48 hours in the urine sterilization rate, degree of clinical improvement, or subsequent hospital admission rate.

Use of propofol sedation in a pediatric emergency department: a prospective study.

The purpose of this study was to determine the efficacy and safety of propofol sedation for pediatric procedures in the emergency department. For patients needing painful procedures, propofol was administered intravenously. Vital signs, complications, and time to recovery were recorded. Patient amnesia and parent, patient, and operator satisfaction with sedation were assessed. The mean age was 7.4 years; 65% were male. Most underwent fracture reduction. Mean total dose was 3.3 mg/kg. Thirty percent experienced desaturation. One required assisted ventilation. Most had decreases in blood pressure. Mean recovery time was 18 minutes. Satisfaction with sedation was rated "excellent." Propofol was an effective sedation with minimal complications in the emergency department setting.

Appendiceal perforation in children diagnosed in a pediatric emergency department.

OBJECTIVE: To determine the incidence of appendiceal perforation (AP) among children with acute appendicitis (AA) and determine factors associated with AP. DESIGN: Retrospective chart review. SETTING: Emergency department (ED) of Primary Children's Medical Center (PCMC). PATIENTS: 131 children less than 17 years of age with AA diagnosed in the PCMC ED. RESULTS: The overall rate of AP was 47%. One hundred eleven (85%) children with AA were correctly diagnosed on their first ED visit. Patients with AP had a significantly (P < 0.05) lower median age (8.0 vs 11.0 years), longer duration of illness (3.0 vs 1.4 days), greater incidence of vomiting and fever by history (91% vs 69% and 83% vs 58%, respectively), higher median temperatures (39.0 degrees vs 38.3 degrees C), and higher proportions of leukocyte (WBC) band forms (14% vs 5%). Patients with AP did not differ from those without AP with respect to total WBC count, hour of arrival, or number of ED visits. CONCLUSIONS: The rate of AP among pediatric patients with AA is greater among younger children and is associated with vomiting, prolonged illness, and higher body temperatures. Unexpectedly, patients with AP did not have higher total WBC values, more frequent late night arrivals, a longer time interval prior to surgery, or more ED visits prior to diagnosis. These findings suggest that efforts to decrease the rate of AP should be directed toward heightening awareness among primary care physicians regarding the high rate of AP in children, with an emphasis on early ED and surgical referral.

Costs of sedation using oral midazolam: money, time, and parental attitudes.

OBJECTIVE: Many agents suitable for pediatric outpatient sedation have been identified and compared, but less data have appeared on the effect of sedation use on Emergency Department (ED) length of stay (LOS) or visit costs. We sought to discover the relationship between one commonly used method of sedation, orally administered midazolam, and ED LOS and visit costs. Parents were then surveyed to determine their attitudes toward sedation given knowledge of these costs. METHODS: All ED patients under 10 years of age seen in a pediatric ED during April and May of 1996 for repair of lacerations <2.5 cm in length were identified via retrospective chart review. Children were excluded if they had other significant injuries, received sedatives other than oral midazolam, or were repaired by non-ED physicians. Preliminary cost and LOS data from this review was used to create a parental survey measuring attitudes toward the costs of an unnamed form of sedation (not mentioning oral midazolam). A convenience sample of parents in an ED waiting room were asked if they would want sedation administered to a child needing sutures if this increased the visit cost by $100 and/or increased LOS by 30 minutes. Parents were then asked to re-answer these questions assuming that the sedation medication was effective only 50% of the time. RESULTS: Of 120 patients meeting entry criteria, 57 (48%) received oral midazolam. Children sedated with this agent were significantly younger (3.6 vs. 4.6 years, P = 0.015), had more layered repairs (30% vs. 14%, P = 0.047), and more facial lacerations (84% vs. 63%, P = 0.01) when compared with nonsedated patients. Mean LOS for patients with simple lacerations receiving oral midazolam increased by 17.1 minutes (P = 0.03) compared with nonsedated children; for layered repairs, the mean increase was 30.9 minutes (P<0.05). The use of oral midazolam did not effect physician charges, but did significantly increase mean combined nurse/hospital charges and total charges by 73 to 87 dollars, depending on laceration type (P<0.001 all cases). Of 81 parents surveyed, 81% said that they would be willing to wait 30 extra minutes for sedation to be used; this figure fell to 73% if sedation was effective 50% of the time. Seventy-five percent of parents were willing to pay $100 extra for sedation; 67% if sedation was effective only half the time. Willingness to endure a longer LOS or pay increased charges was not associated with parental sex or insurance status. CONCLUSION: The use of oral midazolam significantly increases ED visit LOS and cost. This information is important to review with parents when discussing sedation options. Up to one third of parents surveyed would not want to wait extra time or pay extra money for sedation to be administered, especially if the efficacy of the chosen method was not assured.

Binding relationships of membrane tethering components. The giantin N terminus and the GM130 N terminus compete for binding to the p115 C terminus.

By forming a molecular tether between two membranes, p115, giantin, and GM130 may mediate multiple Golgi-related processes including vesicle transport, cisternae formation, and cisternal stacking. The tether is proposed to involve the simultaneous binding of p115 to giantin on one membrane and to GM130 on another membrane. To explore this model, we tested for the presence of the putative giantin-p115-GM130 ternary complex. We first mapped p115-binding site in giantin to a 70-amino acid coiled-coil domain at the extreme N terminus, a position that may exist up to 400 nm away from the Golgi membrane. We then generated glutathione S-transferase (GST) fusion proteins containing either giantin's or GM130's p115 binding site and tested whether such proteins could bind p115 and GM130 or bind p115 and giantin, respectively. Unexpectedly, GST fusions containing either the giantin or the GM130 p115 binding site efficiently bound p115, but the p115 bound to GST-giantin did not bind GM130, and the p115 bound to GST-GM130 did not bind giantin. To explain this result, we mapped the giantin binding site in p115 and found that it is located at the C-terminal acidic domain, the same domain involved in binding GM130. The presence of a single binding site in p115 for giantin and GM130 was confirmed by demonstration that giantin and GM130 compete for binding to p115. These results question a simple tethering model involving a ternary giantin-p115-GM130 complex and suggest that p115-giantin and p115-GM130 interactions might mediate independent membrane tethering events.

Molecular cloning, characterization, and dynamics of rat formiminotransferase cyclodeaminase, a Golgi-associated 58-kDa protein.

A peripherally associated 58-kDa Golgi protein (58K) of unknown function has been previously described (Bloom, G. S., and Brashear, T. A. (1989) J. Biol. Chem. 264, 16083-16092). To molecularly characterize 58K, we used a monoclonal anti-58K antibody (monoclonal antibody 58K-9) to screen a rat liver cDNA expression library. Positive clones were isolated, characterized, and partially sequenced. The obtained sequences show a high level of identity with sequences of porcine formiminotransferase cyclodeaminase (FTCD), suggesting that 58K is rat FTCD. Rat FTCD is structurally similar to porcine FTCD, a metabolic enzyme involved in conversion of histidine to glutamic acid, and exists in dimeric, tetrameric, and octameric complexes resistant to proteolysis. To define parameters of FTCD association with the Golgi, comparison of its behavior with various Golgi and ER-to-Golgi intermediate compartment marker proteins was examined under specific conditions. The results show that extraction parameters of FTCD are similar to those of GM130, a tightly associated Golgi matrix protein. FTCD appears to be a dynamic component of the Golgi, and a proportion of FTCD molecules cycle between the Golgi and earlier compartments of the secretory pathway. FTCD remains associated with Golgi fragments during microtubule disruption and is not released into cytosol during brefeldin A treatment. Instead, FTCD relocates from the Golgi, but the time course of its redistribution is distinct from that of mannosidase II relocation. FTCD is already dispersed into small punctate structures at a time when mannosidase II is still largely localized to Golgi structures. FTCD is not observed in tubules originating from the Golgi and containing mannosidase II. Instead, it appears to redistribute in small vesicles arranged in a linear "pearls on a string" pattern. These results suggest that FTCD relocation is temporally and spatially distinct from mannosidase II relocation and that FTCD provides a novel marker to study Golgi dynamics.

Management of febrile children with urinary tract infections.

This study of the management of children with fever and urinary tract infection (UTI) was conducted to identify factors associated with initial admission, outpatient treatment, and outpatient treatment failure. A retrospective chart review identified children 3 months to 16 years of age with an emergency department (ED) diagnosis of cystitis, pyelonephritis, or UTI, a positive urine culture, and an ED temperature of >38 degrees C. Sixty-nine patients (90% female) were studied; 19% were admitted initially. Age younger than 2 years was associated with admission (P < .001). Of those initially discharged, 63% received parenteral antibiotics (usually intramuscular ceftriaxone), followed by oral antibiotics; 9% failed outpatient treatment. Outpatient failure was associated with higher initial temperatures (median 40.1 degrees C v 39.2 degrees C, P=.03, Mann-Whitney U) but was unrelated to age, initial white blood cell count, or use of parenteral antibiotics. These results indicate that most children with fever and UTI do not require hospital admission; those with temperatures of > or = 40 degrees C are at increased risk for outpatient failure.

The membrane transport factor TAP/p115 cycles between the Golgi and earlier secretory compartments and contains distinct domains required for its localization and function.

The mammalian protein TAP/p115 and its yeast homologue Uso1p have an essential role in membrane traffic (Nakajima et al., 1991; Waters et al., 1992; Sztul et al., 1993; Rabouille et al.; 1995). To inquire into the site and mechanism of TAP/p115 action, we aimed to localize it and to identify domains required for its function. We show that in interphase cells, TAP/p115 localizes predominantly to the Golgi and to peripheral structures that represent vesicular tubular clusters (VTCs) involved in ER to Golgi transport. Using BFA/ nocodazole treatments we confirm that TAP/p115 is present on ER to Golgi transport intermediates. TAP/ p115 redistributes to peripheral structures containing ERGIC-53 during a 15 degreesC treatment, suggesting that it is a cycling protein. Within the Golgi, TAP/p115 is associated with pleiomorphic structures on the cis side of the cis-Golgi cisterna and the cis-most cisterna, but is not detected in more distal compartments of the Golgi. TAP/p115 binds the cis-Golgi protein GM130, and the COOH-terminal acidic domain of TAP/p115 is required for this interaction. TAP/p115 interaction with GM130 occurs only in the Golgi and is not required for TAP/p115 association with peripheral VTCs. To examine whether interaction with GM130 is required to recruit TAP/p115 to the Golgi, TAP/p115 mutants lacking the acidic domain were expressed and localized in transfected cells. Mutants lacking the GM130-binding domain showed normal Golgi localization, indicating that TAP/p115 is recruited to the Golgi independently of its ability to bind GM130. Such mutants were also able to associate with peripheral VTCs. Interestingly, TAP/p115 mutants containing the GM130-binding domain but lacking portions of the NH2-terminal region were restricted from the Golgi and localized to the ER. The COOH-terminal domain required for GM130 binding and the NH2-terminal region required for Golgi localization appear functionally relevant since expression of TAP/p115 mutants lacking either of these domains leads to loss of normal Golgi morphology.

Epidemiological analysis of injury in one year of Canadian professional rodeo.

OBJECTIVES: To document injury rates and treatment use during one competitive season of Canadian professional rodeo. DESIGN: Prospective cohort study. SETTING: Canadian professional rodeo competition. SUBJECTS: Competitors, included professional cowboys from Australia, Brazil, New Zealand, the United States, and Canada. METHODS: Data were gathered prospectively at 15 of 68 professional rodeos in Canada, constituting 22% of all Canadian professional rodeos. Data were collected by four certified athletic therapists using a standardized form. MAIN RESULTS: Overall, 94 athletes were injured during 3,882 individual competitor exposures (CEs). The composite injury rate was 2.3 per 100 CEs. This rate is lower than that reported in contact sports. Within the context of rodeo injuries, bareback riders and bull riders had similar high injury rates (4.6 and 3.6 per 100 CEs, respectively). Saddle bronc riders and steer wrestlers had moderate injury rates (1.4 and 0.9 per 100 CEs, respectively), whereas calf ropers had low injury rates (0.5 per 100 CEs). The knee and ankle were the most frequently treated sites of the body, followed by the shoulder, elbow, and lower back. Acute injury care and prophylactic taping were the most frequent services provided. CONCLUSIONS: In order to study injury patterns in more detail and to assess risk factors for injury, a larger scale epidemiological study should be undertaken. Through such risk-based analysis, preventative strategies could be identified.

Transcytosis-associated protein (TAP)/p115 is a general fusion factor required for binding of vesicles to acceptor membranes.

Transcytosis-associated protein (TAP) is found on transytotic vesicles (TCVs) and is required for their fusion with the target membrane. We developed a cell-free assay capable of differentiating targeting/binding of TCVs to membrane from later fusion events. We found that TAP mediates stable association of TCVs with the target membrane. The sequence of rat liver TAP (959-amino acid open reading frame) encodes a protein that contains (i) an N-terminal region (amino acids 1-649), (ii) an internal region with several coiled-coil stretches (amino acids 650-930), and (iii) a C-terminal acidic region (amino acids 931-959). Comparisons between TAP and other sequences indicate that TAP is identical to p115, a protein involved in cis to medial Golgi transport, and homologous to Uso1p, a yeast protein involved in endoplasmic reticulum to Golgi transport. Our findings suggest that TAP/p115/Usop1 is a general factor acting within the secretory and endocytic pathways to bind transport vesicles prior to membrane fusion.

Comparison of a recombinant endotoxin-neutralizing protein with a human monoclonal antibody to endotoxin for the treatment of Escherichia coli sepsis in rats.

A recombinant endotoxin-neutralizing protein (ENP) from Limulus polyphemus and a monoclonal IgM anti-lipid A antibody (HA-1A) were compared in a rat model of Escherichia coli sepsis. One hour after intraperitoneal challenge with 10(6) cfu of E. coli O18ac K1, animals were sensitized to endotoxin with lead acetate and treated with ENP, HA-1A, or saline, followed by ceftriaxone and gentamicin. Before treatment, 95% of rats had high-grade bacteremia and high serum endotoxin concentrations, which were similar in all treatment groups (P > .60). One hour after treatment, there was no bacterial growth in any blood sample, and endotoxin concentrations were significantly lower in the ENP group than in the HA-1A and saline groups (P < .01). At 24 h after challenge, survival in the ENP group was significantly higher than in the HA-1A saline group (P < .001). ENP improved survival in a rat model of E. coli sepsis with high mortality despite effective antibiotic therapy.