Treatment Failure and Adverse Events After Amoxicillin-Clavulanate vs Amoxicillin for Pediatric Acute Sinusitis

Importance

Acute sinusitis is one of the most common indications for antibiotic prescribing in children, with an estimated 4.9 million such prescriptions in the US annually. Consensus does not exist regarding the optimal empirical antibiotic.

Objective

To compare amoxicillin-clavulanate vs amoxicillin for the treatment of acute sinusitis in outpatient children.

Design, Setting, and Participants

Cohort study of children and adolescents aged 17 years or younger with a new outpatient diagnosis of acute sinusitis and a same-day new prescription dispensation of amoxicillin-clavulanate or amoxicillin in a nationwide health care utilization database. Propensity score matching was used to mitigate confounding.

Exposure

A new prescription dispensation of amoxicillin-clavulanate or amoxicillin.

Main Outcomes and Measures

Treatment failure, defined as an aggregate of a new antibiotic dispensation, emergency department or inpatient encounter for acute sinusitis, or inpatient encounter for a sinusitis complication, was assessed 1 to 14 days after cohort enrollment. Adverse events were evaluated, including gastrointestinal symptoms, hypersensitivity and skin reactions, acute kidney injury, and secondary infections.

Results

The cohort included 320 141 patients. After propensity score matching, there were 198 942 patients (99 471 patients per group), including 100 340 (50.4%) who were female, 101 726 (51.1%) adolescents aged 12 to 17 years, 52 149 (26.2%) children aged 6 to 11 years, and 45 067 (22.7%) children aged 0 to 5 years. Treatment failure occurred in 1.7% overall; 0.01% had serious failure (an emergency department or inpatient encounter). There was no difference in the risk of treatment failure between the amoxicillin-clavulanate and amoxicillin groups (relative risk [RR], 0.98 [95% CI, 0.92-1.05]). The risk of gastrointestinal symptoms (RR, 1.15 [95% CI, 1.05-1.25]) and yeast infections (RR, 1.33 [95% CI, 1.16-1.54]) was higher with amoxicillin-clavulanate. After patients were stratified by age, the risk of treatment failure after amoxicillin-clavulanate was an RR of 0.98 (95% CI, 0.86-1.12) for ages 0 to 5 years; RR was 1.06 (95% CI, 0.92-1.21) for 6 to 11 years; and RR was 0.87 (95% CI, 0.79-0.95) for 12 to 17 years. The age-stratified risk of adverse events after amoxicillin-clavulanate was an RR of 1.23 (95% CI, 1.10-1.37) for ages 0 to 5 years; RR was 1.19 (95% CI, 1.04-1.35) for 6 to 11 years; and RR was 1.04 (95% CI, 0.95-1.14) for 12 to 17 years.

Conclusions and Relevance

In children with acute sinusitis who were treated as outpatients, there was no difference in the risk of treatment failure between those who received amoxicillin-clavulanate compared with amoxicillin, but amoxicillin-clavulanate was associated with a higher risk of gastrointestinal symptoms and yeast infections. These findings may help inform decisions for empirical antibiotic selection in acute sinusitis.

Baseline stool toxin concentration is associated with risk of recurrence in children with Clostridioides difficile infection

BACKGROUND

In adults with Clostridioides difficile infection (CDI), higher stool concentrations of toxins A and B are associated with severe baseline disease, CDI-attributable severe outcomes, and recurrence. We evaluated whether toxin concentration predicts these presentations in children with CDI.

METHODS

We conducted a prospective cohort study of inpatients aged 2-17 years with CDI who received treatment. Patients were followed for 40 days after diagnosis for severe outcomes (intensive care unit admission, colectomy, or death, categorized as CDI primarily attributable, CDI contributed, or CDI not contributing) and recurrence. Baseline stool toxin A and B concentrations were measured using ultrasensitive single-molecule array assay, and 12 plasma cytokines were measured when blood was available.

RESULTS

We enrolled 187 pediatric patients (median age, 9.6 years). Patients with severe baseline disease by IDSA-SHEA criteria (n = 34) had nonsignificantly higher median stool toxin A+B concentration than those without severe disease (n = 122; 3,217.2 vs 473.3 pg/mL; P = .08). Median toxin A+B concentration was nonsignificantly higher in children with a primarily attributed severe outcome (n = 4) versus no severe outcome (n = 148; 19,472.6 vs 429.1 pg/mL; P = .301). Recurrence occurred in 17 (9.4%) of 180 patients. Baseline toxin A+B concentration was significantly higher in patients with versus without recurrence: 4,398.8 versus 280.8 pg/mL (P = .024). Plasma granulocyte colony-stimulating factor concentration was significantly higher in CDI patients versus non-CDI diarrhea controls: 165.5 versus 28.5 pg/mL (P < .001).

CONCLUSIONS

Higher baseline stool toxin concentrations are present in children with CDI recurrence. Toxin quantification should be included in CDI treatment trials to evaluate its use in severity assessment and outcome prediction.

Accuracy of identifying pediatric acute bacterial sinusitis diagnoses in outpatient claims data

PURPOSE

Acute bacterial sinusitis is among the most frequent outpatient infections in children and adolescents and is well suited to study in large healthcare utilization databases, but the validity of International Classification of Diseases, 10^th Revision (ICD-10) codes together with antibiotic prescriptions to identify cases of acute bacterial sinusitis has not been established. We aimed to evaluate the validity of ICD-10 codes combined with antibiotic prescriptions to identify new diagnoses of acute bacterial sinusitis among pediatric patients evaluated in the outpatient setting.

METHODS

Children and adolescents aged 17 years and younger with an outpatient diagnosis of acute sinusitis along with an antibiotic prescription from an ambulatory facility affiliated with the Mass General Brigham health system were identified via a clinical data warehouse. Patients were stratified by age (0-5 years, 6-11 years, and 12-17 years), and fifty cases per age group were randomly sampled. Medical records were independently reviewed by two pediatric infectious diseases physicians to assess for the documentation of a clinician-defined diagnosis of acute bacterial sinusitis. Positive predictive values (PPVs) and 95% confidence intervals (CIs) were calculated.

RESULTS

150 patients were included in the final cohort. Frontal, maxillary, and "unspecified" sinuses accounted for 88% of the diagnoses. The positive predictive value of the algorithm to identify clinician-defined diagnoses of acute bacterial sinusitis was 92% (95% CI 87%,95%). The PPVs were consistent across age strata.

CONCLUSIONS

ICD-10 codes for acute sinusitis, when paired with a same-day antibiotic prescription, have a high positive predictive value among a cohort of pediatric patients, suggesting that they can be used to study new acute bacterial sinusitis diagnoses with claims.

Risk of Infection in Children With Psoriasis Receiving Treatment With Ustekinumab, Etanercept, or Methotrexate Before and After Labeling Expansion

Importance

Psoriasis in children is increasingly treated with systemic medications, yet their risk of serious infection is not well characterized in clinical practice. Pediatric clinical trials for these medications were often small and placebo controlled.

Objective

To estimate the 6-month rate of infections among children with psoriasis who started treatment with ustekinumab, etanercept, or methotrexate.

Design, Setting, and Participants

This cohort study used insurance claims data from clinical practices across the US on children aged 17 years or younger with psoriasis who were receiving treatment with a topical medication for psoriasis and started new treatment with ustekinumab, etanercept, or methotrexate. The analysis was stratified by the time before pediatric labeling (2009-2015) and after pediatric approval (2016-2021). Patient follow-up started 1 day after initiating treatment and ended at 6 months.

Exposures

New treatment with ustekinumab, etanercept, and methotrexate.

Main Outcomes and Measures

During follow-up, the frequency of inpatient serious infections and outpatient infections requiring treatment was compared. Event rates and rate ratios were estimated after propensity score decile stratification.

Results

After exclusions, we identified 2338 patients (1368 girls [57.8%]) who initiated new treatment with a targeted immunomodulating agent. In all, 379 patients started treatment with ustekinumab, 779 patients started treatment with etanercept, and 1180 patients started treatment with methotrexate from 2009 through 2021. The propensity score-adjusted incidence rate of serious infection was 18.4 per 1000 person-years (3 events) for ustekinumab users, 25.6 per 1000 person-years (9 events) for etanercept users, and 14.9 per 1000 person-years (8 events) for methotrexate users. The adjusted rate of outpatient infections was 254.9 per 1000 person-years (39 events) for ustekinumab users, 435.7 per 1000 person-years (139 events) for etanercept users, and 433.6 per 1000 person-years (209 events) for methotrexate users. The adjusted rate ratio of outpatient infections was 0.58 (95% CI, 0.41-0.83) for ustekinumab vs etanercept, 0.66 (95% CI, 0.48-0.91) for ustekinumab vs methotrexate, and 0.95 (95% CI, 0.75-1.21) for etanercept vs methotrexate. Rate ratios were similar during the off-label use era and after pediatric labeling.

Conclusions and Relevance

Among children with psoriasis who started treatment with immunomodulating agents, serious infections were infrequent. This cohort study suggests that there was no increase in the risk of outpatient infections for children who started treatment with ustekinumab compared with etanercept or methotrexate.

563. Nationwide Trends in Antibiotic Selection for the Treatment of Pediatrics Acute Sinusitis, 2003-2020

Background

Acute sinusitis is a common diagnosis associated with outpatient antibiotic prescribing for children. Infectious Diseases Society of America guidelines (published in 2012) and American Academy of Pediatrics guidelines (published in 2013) for the management of acute sinusitis recommend amoxicillin with or without clavulanate as empiric therapy. Nationwide trends in antibiotic treatment of sinusitis have not been described since guideline publication.

Methods

We evaluated trends in antibiotic prescriptions for new acute sinusitis diagnoses among commercially insured patients &lt; 18 years old between January 1, 2003 and December 31, 2020 using the MarketScan Research Database. Subjects were identified via an outpatient encounter with an ICD code for acute sinusitis along with an oral antibiotic prescription dispensed on the day of the visit. New diagnoses were defined as having no sinusitis diagnosis in the preceding 180 days. Patients were excluded if they had a diagnosis code for chronic sinusitis or cystic fibrosis in the 6 months prior to the acute sinusitis diagnosis or had a same-day ICD code for another infection that would influence antibiotic selection (acute otitis media, cellulitis/abscess, community acquired pneumonia, Group A Streptococcal pharyngitis/tonsillitis, or urinary tract infection).

Results

3.3 million patients met the inclusion and exclusion criteria (Table 1). From 2003-2012, about 50% of patients received amoxicillin with or without clavulanate (Figure 1). Since 2013, the proportion of patients receiving first line antibiotics increased by 13%. The proportion receiving two or more antibiotics was unchanged. Approximately 80% of patients were prescribed 10-13 days of antibiotics (Figure 2). The proportion of patients receiving 14 or more days decreased by 67% over the study period.

Conclusion

In a nationwide cohort of commercially insured children with acute sinusitis, prescriptions for amoxicillin with or without clavulanate increased after publication of society guidelines. About 40% of patients are prescribed a non-first line antibiotic or multiple antibiotics and nearly 90% of patients are prescribed 10 or more days of antibiotics, presenting important opportunities for antimicrobial stewardship interventions.

Disclosures

Timothy J. Savage, MD, MPH, MSc, UCB: Contract to Brigham and Women's Hospital.

883. Stool Toxin Concentrations Are Higher in Children with Baseline Severe Disease, Severe Outcomes, and Recurrence

Background

In adults with C. difficile infection (CDI), higher baseline stool concentrations of toxins A and B are associated with severe baseline disease, CDI-attributable severe outcomes, and recurrence. We evaluated whether stool toxin concentration predicts these presentations in children with CDI.

Methods

We performed a prospective cohort study from 2016-2019. Participants were inpatients ≤17 years old at two pediatric hospitals with diarrhea and positive C. difficile testing who received therapy. Patients were followed for 40 days after baseline stool sample for severe outcomes (intensive care unit admission, colectomy, or death, categorized as CDI primarily attributable, CDI contributed, or CDI not contributing) and recurrence (resolution followed by new diarrhea and re-initiation of therapy). Baseline stool toxin A & B concentrations were measured using ultrasensitive single molecule array assay (cutoff for positive result = 20 pg/mL). Median baseline toxin concentrations were compared between groups using Wilcoxon tests.

Results

We enrolled 206 patients [median age 8.9 years (IQR, 4.7–13.2)]. Children with severe baseline disease by IDSA-SHEA criteria (n = 39) had higher median stool toxin A+B concentration than those without severe disease (n = 131) (2,912.6 vs. 500.5 pg/mL, P=0.05). Of the cohort, 40 (19%) had a severe outcome (4 primarily attributed to CDI, 19 with contribution from CDI, and 17 unrelated to CDI). Median toxin A+B concentration was non-significantly higher in children with a primarily-attributed severe outcome versus those without severe outcome (19,473 vs. 429.1 pg/mL, P=0.317) (Figure 1). Of 197 children with eligible data, recurrence occurred in 18 (9.1%); baseline toxin A+B concentration was significantly higher in patients with versus without recurrence (3,946.7 vs. 283.3 pg/mL, P=0.026) (Figure 2).

Conclusion

Higher stool toxin concentrations are present in children with baseline severe CDI, a CDI-attributable severe outcome, or recurrence compared with children without these presentations. Quantification of stool toxin concentration may be helpful in identifying severe CDI and predicting CDI outcomes, which could help guide decisions about clinical management.

Disclosures

Larry K. Kociolek, MD, MSCI, Merck: Grant/Research Support Timothy J. Savage, MD, MPH, MSc, UCB: Contract to Brigham and Women's Hospital Alice Banz, PhD, biomerieux: Simoa assays were performed by bioMerieux, and A.B. is an employee of bioMerieux Kevin W. Garey, PharmD, MS, Acurx: Grant/Research Support|cidara: Advisor/Consultant|cidara: Grant/Research Support|Paratek: Grant/Research Support|Seres Health: Grant/Research Support|Summit: Grant/Research Support Ciaran P. Kelly, n/a, Artugen: Advisor/Consultant|Facile Therapeutics: Advisor/Consultant|Ferring Pharma: Advisor/Consultant|Finch: Advisor/Consultant|Finch: Advisor/Consultant|First Light Biosciences: Advisor/Consultant|First Light Biosciences: Ownership Interest|Milky Way Biosciences: Advisor/Consultant|Milky Way Biosciences: Grant/Research Support|Pfizer: Advisor/Consultant|Seres Therapeutics: Advisor/Consultant|Summit Therapeutics: Advisor/Consultant.

Stool Toxin Concentration Does Not Distinguish Clostridioides difficile Infection from Colonization in Children Less Than 3 Years of Age

In a prospective cohort study, stools from children <3 years with and without diarrhea who were Clostridioides difficile nucleic acid amplification test-positive underwent ultrasensitive and quantitative toxin measurement. Among 37 cases and 46 controls, toxin concentration distributions overlapped substantially. Toxin concentration alone does not distinguish C. difficile infection from colonization in young children.

Comorbidities Associated with Hospitalization and Progression Among Adolescents with Symptomatic Coronavirus Disease 2019

OBJECTIVE

To identify subgroups likely to benefit from monoclonal antibody and antiviral therapy by evaluating the relationship between comorbidities and hospitalization among US adolescents with symptomatic coronavirus disease 2019 (COVID-19).

STUDY DESIGN

We analyzed the relationship between presence of comorbidities and need for hospitalization within 28 days of COVID-19 diagnosis for adolescents aged 12-17 years listed in the Pediatric COVID-19 US registry, a multicenter retrospective cohort of US pediatric patients with COVID-19. Comorbidities assessed included obesity, chronic kidney disease (CKD), diabetes, immunosuppressive disease or treatment, sickle cell disease (SCD), heart disease, neurologic disease/neurodevelopmental disorders, and pulmonary disease (excluding patients with mild asthma). We used multivariable logistic regression to determine race/ethnicity-adjusted associations between comorbidities and hospitalization.

RESULTS

A total of 1877 patients met our inclusion criteria, of whom 284 (15%) were hospitalized within 28 days of their COVID-19 diagnosis. In a race/ethnicity-adjusted model, the following comorbidities were independently associated with increased odds of hospitalization: SCD (aOR, 6.9; 95% CI, 3.0-15.9), immunocompromising condition (aOR, 6.4; 95% CI, 3.8-10.8), obesity (aOR, 3.2; 95% CI, 2.1-4.9), diabetes (aOR, 3.0; 95% CI, 1.4-6.2), neurologic disease (aOR, 2.8; 95% CI, 1.8-4.3), and pulmonary disease (excluding mild asthma) (aOR, 1.9; 95% CI, 1.2-3.1). Heart disease and CKD were not independently associated with hospitalization.

CONCLUSIONS

SCD, immunocompromising conditions, obesity, diabetes, neurologic disease, and pulmonary disease (excluding mild asthma) were associated with hospitalization for symptomatic COVID-19. Adolescents with acute COVID-19 and these comorbidities should be prioritized for consideration of therapy to avert hospitalization.

Trends in clinical presentation of children with COVID-19: a systematic review of individual participant data

BACKGROUND

There are sparse patient-level data available for children with novel coronavirus disease (COVID-19). Therefore, there is an urgent need for an updated systematic literature review that analyzes individual children rather than aggregated data in broad age groups.

METHODS

Six databases (MEDLINE, Scopus, Web of Science, CINAHL, Google Scholar, medRxiv) were searched for studies indexed from January 1 to May 15, 2020, with MeSH terms: children, pediatrics, COVID-19, SARS-CoV-2. 1241 records were identified, of which only unique papers in English with individual patient information and documented COVID-19 testing were included. This review of 22 eligible studies followed Preferred Reporting Items for Systematic Review and Meta-Analyses of individual participant data guidelines.

RESULTS

A total of 123 patients from five countries were identified. 46% were females. The median age was 5 years (IQR = 8). At presentation, 62% had a fever, 32% had a cough, 58% had a single symptom, and 21% were asymptomatic. Abnormal chest imaging was seen in 62% (65/105) of imaged and 76.9% (20/26) of asymptomatic children. A minority of children had elevated platelets, CRP, lactate dehydrogenase, and D-dimer.

CONCLUSION

Data from this independent participant data systematic review revealed that the majority of children with COVID-19 presented with either no symptoms or a single, non-respiratory symptom.

IMPACT

This systematic review revealed that the majority of children with COVID-19 presented with either no symptoms or a single, non-respiratory symptom. By using an independent participant data approach, this analysis underscores the challenge of diagnosing COVID-19 in pediatric patients due to the wide variety of symptoms and seemingly poor correlation of imaging findings with symptomatic disease. The data presented from individual patients from case series or cohort studies add more granularity to the current description of pediatric COVID-19.

Clostridioides difficile Infection in Children: The Role of Infection Prevention and Antimicrobial Stewardship

There are 2 primary approaches to prevent Clostridioides difficile infection (CDI) in children: prevent transmission and acquisition of the organism and prevent the progression from colonization to disease. The most important interventions to reduce the risk of transmission include contact precautions, hand hygiene, and environmental disinfection. Glove use minimizes contamination of the hands by spores and is associated with reductions in CDI incidence. Hand hygiene with soap and water and disinfection with a sporicidal agent are recommended as the best approaches in hyperendemic settings. Because antibiotic exposure is the most important modifiable risk factor for CDI, antimicrobial stewardship focused on identified high-risk antibiotic classes (including clindamycin, fluoroquinolones, and third- and fourth-generation cephalosporins) is critical to preventing progression from colonization to infection. Despite clear evidence that antimicrobial stewardship programs (ASPs) are associated with reduced CDI rates in adults, data demonstrating the ASP impact on pediatric CDI are lacking.

Predictive Value of Direct Disk Diffusion Testing from Positive Blood Cultures in a Children's Hospital and Its Utility in Antimicrobial Stewardship

Accurate and early susceptibility results could reduce overuse of broad-spectrum antibiotics for empirical treatment of bacteremia. Direct disk diffusion testing (dDD) using nonstandardized inocula directly from blood cultures could facilitate earlier narrowing of antibiotics. To determine the predictive value of dDD compared with standardized antimicrobial susceptibility testing (AST), we performed a retrospective cohort study of 582 blood cultures from 495 pediatric patients with bacteremia. Positive and negative predictive value (PPV: number of isolates susceptible by both dDD and AST divided by the total number of isolates susceptible by dDD; NPV: number of isolates not susceptible [either intermediate or resistant] by both dDD and AST divided by the total number of isolates not susceptible by dDD), sensitivity, specificity, and 95% confidence interval were calculated for each bacterium-antibiotic combination. We evaluated the Antibiotic Spectrum Index of prescribed antibiotics to assess change in antibiotic prescribing after availability of Gram stain, dDD, and AST results. dDD results were available a median of 21 h before AST results. dDD had PPVs of ≥96% for most organism-antibiotic pairs, including 100% (CI 96 to 100%) for Staphylococcus aureus with oxacillin and 99% (CI 93 to 100%) for Enterobacterales with ceftriaxone. NPVs of dDD were variable and frequently lower than the PPV. Very major errors and major errors occurred in 31/5,454 (0.6%) and 231/5,454 (4.2%) organism-antibiotic combinations, respectively. Antibiotics were narrowed in 30% of cases after a dDD result and a further 25% of cases after AST result. dDD is highly predictive of susceptibility for many common organism-antibiotic combinations and provides actionable information one day earlier than standard susceptibility approaches. dDD has the potential to facilitate earlier deescalation to narrow-spectrum antibiotic treatment.

Correlation of SARS-CoV-2 Nucleocapsid Antigen and RNA Concentrations in Nasopharyngeal Samples from Children and Adults Using an Ultrasensitive and Quantitative Antigen Assay

Diagnosis of COVID-19 by PCR offers high sensitivity, but the utility of detecting samples with high cycle threshold (CT ) values remains controversial. Currently available rapid diagnostic tests (RDTs) for SARS-CoV-2 nucleocapsid antigens (Ag) have sensitivity well below PCR. The correlation of Ag and RNA quantities in clinical nasopharyngeal (NP) samples is unknown. An ultrasensitive, quantitative electrochemiluminescence immunoassay for SARS-CoV-2 nucleocapsid (the MSD S-PLEX SARS-CoV-2 N assay) was used to measure Ag in clinical NP samples from adults and children previously tested by PCR. The S-PLEX Ag assay had a limit of detection (LOD) of 0.16 pg/ml and a cutoff of 0.32 pg/ml. Ag concentrations measured in clinical NP samples (collected in 3.0 ml of media) ranged from less than 160 fg/ml to 2.7 μg/ml. Log-transformed Ag concentrations correlated tightly with CT values. In 35 adult and 101 pediatric PCR-positive samples, the sensitivities were 91% (95% confidence interval, 77 to 98%) and 79% (70 to 87%), respectively. In samples with a CT of ≤35, the sensitivities were 100% (88 to 100%) and 96% (88 to 99%), respectively. In 50 adult and 40 pediatric PCR-negative specimens, the specificities were 100% (93 to 100%) and 98% (87 to 100%), respectively. Nucleocapsid concentrations in clinical NP samples span 8 orders of magnitude and correlate closely with RNA concentrations (CT values). The S-PLEX Ag assay showed 96 to 100% sensitivity in samples from children and adults with CT values of ≤35, and a specificity of 98 to 100%. These results clarify Ag concentration distributions in clinical samples, providing insight into the performance of Ag RDTs and offering a new approach to diagnosis of COVID-19.

Enterovirus D-68 in children presenting for acute care in the hospital setting

BACKGROUND

Severe respiratory disease associated with enterovirus D68 (EV-D68) has been reported in hospitalized pediatric patients. Virologic and clinical characteristics of EV-D68 infections exclusively in patients presenting to a hospital Emergency Department (ED) or urgent care have not been well defined.

METHODS

Mid-nasal swabs from pediatric patients with respiratory symptoms presenting to the ED or urgent care were evaluated using a commercial multiplex PCR platform. Specimens positive for rhinovirus/enterovirus (HRV/EV) were subsequently tested using real-time reverse-transcriptase PCR for EV-D68. The PCR cycle threshold (CT) was used as a viral load proxy. Clinical outcomes were compared between patients with EV-D68 and patients without EV-D68 who tested positive for HRV/EV.

RESULTS

From August to December 2014, 511 swabs from patients with HRV/EV were available. EV-D68 was detected in 170 (33%) HRV/EV-positive samples. In multivariable models adjusted for age and underlying asthma, patients with EV-D68 were more likely to require hospitalization for respiratory reasons (odds ratio (OR): 3.11, CI: 1.85-5.25), require respiratory support (OR: 1.69, CI: 1.09-2.62), have confirmed/probable lower respiratory tract infection (LRTI; OR: 3.78, CI: 2.03-7.04), and require continuous albuterol or steroids (OR: 3.91, CI: 2.22-6.88 and OR: 4.73, CI: 2.65-8.46, respectively). Higher EV-D68 viral load was associated with need for respiratory support and LRTI in multivariate models.

CONCLUSIONS

Among pediatric patients presenting to the ED or urgent care, EV-D68 causes more severe disease than non-EV-D68 HRV/EV independent of underlying asthma. High viral load was associated with worse clinical outcomes. Rapid and quantitative viral testing may help identify and risk stratify patients.

Elevated expression of adenosine A1 receptor in bronchial biopsy specimens from asthmatic subjects

Asthmatics, unlike healthy subjects, experience bronchoconstriction in response to inhaled adenosine, and extracellular adenosine concentrations are elevated in the bronchoalveolar lavage fluid and exhaled breath condensate of asthmatic subjects. However, little is known about the location and expression of adenosine receptors in asthmatic airways. The aim of the present study was to investigate the distribution of adenosine A(1) receptors in bronchial biopsy specimens from mildly asthmatic steroid-naïve subjects and then compare the degree of expression with that of healthy subjects. Biopsy sections were immunostained using an adenosine A(1) receptor antibody, the selectivity of which was validated in specific experiments. Image analysis was then performed in order to determine differences in immunostaining intensity. Immunostaining of biopsy sections from the asthmatic subjects revealed strong expression of the A(1) receptor, located predominantly in the bronchial epithelium and bronchial smooth muscle. In comparison, very weak immunostaining was observed in biopsy specimens obtained from healthy subjects. Image analysis revealed that the intensity of positive staining of the asthmatic bronchial epithelium and smooth muscle regions was significantly greater than that observed for the healthy epithelium and smooth muscle. In conclusion, the sensitivity of asthmatics to inhaled adenosine coupled with increased adenosine A(1) receptor expression implies that these receptors play a role in the pathophysiology of this disease.

Airway subepithelial fibrosis in a murine model of atopic asthma: suppression by dexamethasone or anti-interleukin-5 antibody

Fibrosis in the reticular layer beneath the epithelial basement membrane is a feature of airway remodeling in human asthma. We previously reported the presence of subepithelial fibrosis (SEF) in a disease model of atopic asthma in which mice were sensitized and intratracheally challenged with ovalbumin (OVA) (Blyth and colleagues, Am. J. Respir. Cell Mol. Biol. 1996;14:425-438). Here, we describe further studies to quantify the degree of SEF after its induction by repeated exposure of the airways to allergen. The amount of subepithelial reticulin in the airways of animals challenged three times with 80 microg OVA was typically increased 1. 4-fold. The increased amount of reticulin showed no reduction after a 50-d period after the third allergen challenge. A reduction in SEF was achieved by daily treatment with dexamethasone (DEX) for 8 d during the allergen challenge period, or by treatment with anti-interleukin-5 antibody (TRFK5) at the time of allergen challenge. Postchallenge treatment with DEX for 15 d resulted in significant resolution of previously established SEF. Severe nonallergic inflammation during repeated exposure of airways to lipopolysaccharide did not induce SEF. The results indicate that development of SEF is associated with eosinophil infiltration into airways, and may occur only when the inflammatory stimulus is allergic in nature.

Monoterpene synthases of loblolly pine (Pinus taeda) produce pinene isomers and enantiomers

The turpentine fraction of conifer oleoresin is a complex mixture of monoterpene olefins and plays important roles in defense and in the mediation of chemical communication between conifer hosts and insect predators. The stereochemistry of the turpentine monoterpenes is critical in these interactions, influencing host recognition, toxicity, and potency of derived pheromones, and the stereochemical composition of these compounds lends insight into their biogenetic origin, with implications for the numbers and types of enzymes responsible and their corresponding genes. Analysis of the oleoresin from several tissues of loblolly pine (Pinus taeda) showed the derived turpentine to consist mainly of (+)-(3R:5R)-alpha-pinene and (-)-(3S:5S)-beta-pinene. Cell-free extracts from xylem tissue yielded three monoterpene synthases which together account for the monoterpene isomer and enantiomer content of the turpentine of this tissue. The major products of these enzymes, produced from the universal precursor of monoterpenes, geranyl diphosphate, were shown to be (+)-alpha-pinene, (-)-alpha-pinene, and (-)-beta-pinene, respectively. In most properties (molecular mass of approximately 60 kDa, K(m) for geranyl diphosphate of 3 microM, requirement for monovalent and divalent cations), these enzymes resemble other monoterpene synthases from conifer species.

Induction, duration, and resolution of airway goblet cell hyperplasia in a murine model of atopic asthma: effect of concurrent infection with respiratory syncytial virus and response to dexamethasone

We recently described a murine model of atopic asthma in which a marked, extensive hyperplasia of airway goblet cells is induced by repeated challenge of ovalbumin (OA)-sensitized mice with intratracheally administered allergen (Am. J. Respir. Cell Mol. Biol. 1996;14:425-438). We report here the time course of the duration of this feature and of its spontaneous resolution in the absence of further allergen exposure. Induction of severe neutrophilic inflammation in the airways by repeated intratracheal administration of lipopolysaccharide failed to induce goblet cell hyperplasia (GCH) to as great a degree as that induced by allergen, suggesting that nonallergic inflammation is a relatively poor inducer of this phenotype change in mice. When a "subclinical" infection of the lungs with the human A2 strain of respiratory syncytial virus was superimposed on the model of atopic asthma, recruitment of monocytes and lymphocytes to the airways was enhanced and a discharge of goblet cell mucin contents was observed. This may partly explain the respiratory difficulty that typifies virally induced exacerbations of asthma in humans. Daily systemic treatment of sensitized mice with dexamethasone during the period of allergen challenge produced a dose-related suppression of developing GCH, while similar treatment during the period following the establishment of extensive hyperplasia induced an accelerated resolution toward a normal epithelial phenotype. These results confirm and extend the relevance of this model as a representation of the human disease.

Monoterpene synthases from common sage (Salvia officinalis). cDNA isolation, characterization, and functional expression of (+)-sabinene synthase, 1,8-cineole synthase, and (+)-bornyl diphosphate synthase

Common sage (Salvia officinalis) produces an extremely broad range of cyclic monoterpenes bearing diverse carbon skeletons, including members of the p-menthane (1,8-cineole), pinane (alpha- and beta-pinene), thujane (isothujone), camphane (camphene), and bornane (camphor) families. An homology-based polymerase chain reaction cloning strategy was developed and used to isolate the cDNAs encoding three multiproduct monoterpene synthases from this species that were functionally expressed in Escherichia coli. The heterologously expressed synthases produce (+)-bornyl diphosphate, 1, 8-cineole, and (+)-sabinene, respectively, as their major products from geranyl diphosphate. The bornyl diphosphate synthase also produces significant amounts of (+)-alpha-pinene, (+)-camphene, and (+/-)-limonene. The 1,8-cineole synthase produces significant amounts of (+)- and (-)-alpha-pinene, (+)- and (-)-beta-pinene, myrcene and (+)-sabinene, and the (+)-sabinene synthase produces significant quantities of gamma-terpinene and terpinolene. All three enzymes appear to be translated as preproteins bearing an amino-terminal plastid targeting sequence, consistent with the plastidial origin of monoterpenes in plants. Deduced sequence analysis and size exclusion chromatography indicate that the recombinant bornyl diphosphate synthase is a homodimer, whereas the other two recombinant enzymes are monomeric, consistent with the size and subunit architecture of their native enzyme counterparts. The distribution and stereochemistry of the products generated by the recombinant (+)-bornyl diphosphate synthase suggest that this enzyme might represent both (+)-bornyl diphosphate synthase and (+)-pinene synthase which were previously assumed to be distinct enzymes.

Lung inflammation and epithelial changes in a murine model of atopic asthma

A murine model of allergen-induced airway inflammation and epithelial phenotypic change, and the time-courses of these events, are described. Mice were sensitized to ovalbumin using an adjuvant-free protocol, and challenged by multiple intratracheal instillations of ovalbumin by a non-surgical technique. Many of the characteristic features of human atopic asthma were seen in the mice. A marked eosinophilic infiltration of lung tissue and airways followed allergen challenge, and its severity increased with each challenge, as did the number of eosinophils in the blood. Lymphocytes, neutrophils, and monocytes also invaded the lungs. Airway macrophages showed signs of activation, their appearance resembling those recovered from antigen-challenged human asthmatic airways. The airway epithelium was thickened and displayed a marked goblet cell hyperplasia in terminal bronchioles and larger airways. After repeated challenges, the reticular layer beneath the basement membrane of the airway epithelium showed fibrosis, reproducing a commonly observed histologic feature of human asthma. Goblet cell hyperplasia began to appear before eosinophils or lymphocytes had migrated across the airway epithelium, and persisted for at least 11 days after the third intratracheal challenge with ovalbumin, despite the number of inflammatory cells in the lungs and airways having decreased to near-normal levels by 4 days. Plugs of mucus occluded some of the airways. These results indicate that some of the phenotypic changes in airway epithelium that follow an allergic response in the lung can be initiated before the migration of eosinophils or lymphocytes across the epithelial layer.

Internal fixation of distal fibula fractures: a case presentation demonstrating a unique technique for a severely comminuted fibula

The laterally comminuted fracture-dislocation of the ankle can be associated with devastating consequences. Previously described surgical as well as nonsurgical-treatment results have been disappointing. Accurate anatomical reduction and rigid fracture stabilization of a comminuted fibula can be extremely difficult. This manuscript presents some of the more common methods of comminuted fibular fracture fixation described in the literature. A case report demonstrates successful anatomical stabilization of a comminuted fibula, utilizing a method for internal fibular fixation which has been previously employed, but has not been advocated, in the literature. Clinical and radiographic results at 12 and 20 months post-injury are promising.

The internal fixation of ankle fracture repair

A descriptive overview of the type of internal fixation, the biomechanical principles of this fixation technique, and the methods of application are outlined. Clinical illustrations demonstrate some of the more commonly used internal fixation techniques.

Monoterpene synthases from gymnosperms and angiosperms: stereospecificity and inactivation by cysteinyl- and arginyl-directed modifying reagents

To further define specific structural and mechanistic differences among monoterpene synthases from divergent plant sources, the stereospecificity of the enzyme-catalyzed isomerization of geranyl pyrophosphate to linalyl pyrophosphate and the subsequent cyclization to monoterpene olefins (which have been well established for monoterpene synthases from herbaceous angiosperms) were examined for monoterpene synthases from a conifer, lodgepole pine (Pinus contorta). The chiral monoterpenes isolated from lodgepole pine oleoresin and the major chiral products from cell-free assays of each of the four lodgepole pine monoterpene synthases belonged to the stereochemical family related by the biosynthetic intermediacy of 3S-linalyl pyrophosphate. Furthermore, both the putative intermediate, 3S-linalyl pyrophosphate, and the natural substrate, geranyl pyrophosphate, were enzymatically converted to the same monoterpene enantiomers. Thus, like monoterpene synthases from herbaceous angiosperms, monoterpene synthases from lodgepole pine appear to catalyze both the stereospecific isomerization of geranyl pyrophosphate to linalyl pyrophosphate and the subsequent cyclization of this enzyme-bound intermediate to multiple, stereochemically related monoterpene olefin isomers. The susceptibility of monoterpene synthases to inactivation by cysteinyl- and arginyl-directed chemical modification reagents was also examined to identify specific structural differences between enzymes from conifers and angiosperms. Like monoterpene synthases from peppermint (Mentha x piperita) and culinary sage (Salvia officinalis), monoterpene synthases from lodgepole pine were inactivated by thiol-directed reagents; however, unlike monoterpene synthases from these herbaceous angiosperms, monoterpene synthases from lodgepole pine were not protected against inactivation by coincubation with substrate and metal ion cofactor. Lodgepole pine monoterpene synthases were also inactivated by the arginyl-directed reagent phenylglyoxal, and coincubation with substrate and cofactor, to effect active-site protection, reduced the rate of inactivation 10-fold. (+)-Pinene synthase and (-)-pinene synthase from sage were also inactivated by phenylglyoxal, but no protection was afforded by coincubation with substrate and cofactor. Thus, monoterpene synthases of conifers appear to have catalytically important arginyl residues specifically located at or near the active site and have at least some catalytically important thiol residues at a non-substrate-protectable region of the enzyme, in contrast to monoterpene synthases from angiosperms which appear to have catalytically important cysteinyl residues at the active site and have catalytically important arginyl residues located at a non-substrate-protectable region of the enzyme.

Monoterpene synthases of Pinus contorta and related conifers. A new class of terpenoid cyclase

A cell-free extract from the xylem of lodgepole pine (Pinus contorta) catalyzes the conversion of [1-3H1]geranyl pyrophosphate to a variety of monoterpene olefins found in lodgepole pine oleoresin. This monoterpene synthase activity is similar to previously described terpenoid cyclases from grand fir (Abies grandis) and other higher plants in molecular mass (67 +/- 2 kDa as estimated by size-exclusion chromatography), Km for geranyl pyrophosphate (7.8 +/- 1.9 microM), and isoelectric point (4.75 +/- 0.2 as determined by isoelectric focusing), but the cyclases from both lodgepole pine and grand fir are unlike previously characterized terpenoid cyclases from angiosperms and fungi, in that they have an alkaline pH optimum (pH 7.8), are activated by K+, Rb+, Cs+, or NH+4 (Li+ and Na+ are not effective), require either Mn2+ or Fe2+ as divalent metal ion cofactors (Mg2+ is not effective), and are not protected by the substrate-metal ion complex against inhibition by the histidine-directed reagent diethyl pyrocarbonate. Chromatography of the pine xylem extracts on a quaternary amino anion-exchange resin results in the separation of four similar, but distinct, multiple product monoterpene synthases that produce sabinene, beta-phellandrene, 3-carene, and beta-pinene as the principal components, respectively. The major cyclase (phellandrene synthase) was subsequently purified by hydroxyapatite chromatography and electrophoresis. V8 proteolysis provided a peptide map significantly different from that obtained with limonene synthase from spearmint (Mentha spicata), and limited NH2-terminal sequencing of the phellandrene synthase fragments revealed no significant similarity to the deduced amino acid sequence of the angiosperm limonene synthase, the only monoterpene cyclase to be cloned and sequenced thus far. Furthermore, polyclonal antibodies raised against the angiosperm limonene synthase did not detectably cross-react with any proteins in extracts from either lodgepole pine or grand fir by immunoblotting analysis. In addition to these structural differences between cyclases from conifers and herbaceous angiosperms, the unusual pH optimum, mono- and divalent metal ion requirement, and reactivity toward histidine carbethoxylation indicate that monoterpene cyclases isolated from conifers may also have a different complement of active-site amino acid residues involved in substrate binding and catalysis than those of terpenoid cyclases previously isolated from angiosperms.

Biosynthesis of monoterpenes: regio- and stereochemistry of (+)-3-carene biosynthesis

Incubation of [1-3H1]geraniol with stem disks of Douglas fir (Pseudotsuga menziesii) and incubation of [1-3H1]geranyl pyrophosphate with both a soluble enzyme extract from Douglas fir and a partially purified preparation of (+)-3-carene synthase from lodgepole pine (Pinus contorta) resulted in the production of (+)-3-[3H] carene. Subsequent conversion of the product to car-3-en-5-one and to 4-isocaranone followed by base-catalyzed exchange of the alpha-hydrogens established that the 3H located at C1 in the geranyl substrate resided at C5 of (+)-3-carene. Incubation of the (+)-3-carene synthase preparation with (S)-[5-3H1, 4-14C]geranyl pyrophosphate resulted in the production of (+)-3-carene without loss of tritium, indicating that the 5-proR hydrogen is eliminated during cyclopropyl ring closure. Analysis of the conformational requirements for this 1,3 elimination involving the 5-proR hydrogen suggested that cyclopropyl ring formation occurs via a (4S)-alpha-terpinyl cation derived from the anti-endo cyclization of a (3S)-linalyl pyrophosphate intermediate. Kinetic analyses of the conversion of (1Z,3R)-[1-3H1]linalyl pyrophosphate, (1Z, 3S)-[1-3H1]linalyl pyrophosphate and [1-3H1]geranyl pyrophosphate by (+)-3-carene synthase revealed that the velocity of the reaction with the (3S)-linalyl enantiomer was 25-fold greater than the velocity with the (3R)-enantiomer and twice that of the natural substrate, geranyl pyrophosphate, thereby confirming this stereochemical prediction and also indicating that the cyclization of the linalyl intermediate is faster than the coupled isomerization and cyclization of the geranyl substrate. From these results, a model that details the regio- and stereochemistry of the enzymatic conversion of geranyl pyrophosphate to (+)-3-carene is proposed.

Defense mechanisms of conifers : relationship of monoterpene cyclase activity to anatomical specialization and oleoresin monoterpene content

Cell-free extracts from Pinus ponderosa Lawson (ponderosa pine) and Pinus sylvestris L. (Scotch pine) wood exhibited high levels of monoterpene synthase (cyclase) activity, whereas bark extracts of these species contained no detectable activity, and they inhibited cyclase activity when added to extracts from wood, unless polyvinylpyrrolidone was included in the preparation. The molecular mass of the polyvinylpyrrolidone added was of little consequence; however, polyvinylpolypyrrolidone (a cross-linked insoluble form of the polymer) was ineffective in protecting enzyme activity. Based on these observations, methods were developed for the efficient extraction and assay of monoterpene cyclase activity from conifer stem (wood and bark) tissue. The level of monoterpene cyclase activity for a given conifer species was shown to correlate closely with the monoterpene content of the oleoresin and with the degree of anatomical complexity of the specialized resin-secreting structures. Cyclase activity and monoterpene content were lowest in the stems of species containing only isolated resin cells, such as western red cedar (Thuja plicata D. Don). Increasing levels of cyclase activity and oleoresin monoterpenes were observed in advancing from species with multicellular resin blisters (true firs [Abies]) to those with organized resin passages, such as western larch (Larix occidentalis Nutt.), Colorado blue spruce (Picea pungens Engelm.) and Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco). The highest levels of cyclase activity and oleoresin monoterpenes were noted in Pinus species that contain the most highly developed resin duct systems. The relationship between biosynthetic capacity, as measured by cyclase activity, monoterpene content, and the degree of organization of the secretory structures for a given species, may reflect the total number of specialized resin-producing cells per unit mass of stem tissue.

Navigating the system governance maze

Health care system governance today is a complex maze of concerns that assume a unique character in Catholic-sponsored multi-institutional systems. Most Catholic health care systems began with a common sponsor or mission and several shared services and gradually moved from separately incorporated entities to a system with few centralized operating functions but a governing body between the local facilities and the sponsoring religious institute. The next step was development of a managed system with consolidated services and centralized decision making. Now, many systems are attempting the most important and difficult effort--systemwide strategic planning. The phases described have required a rethinking of governance structures, and conflicts often arise during restructuring. Such turmoil requires many Catholic health care systems to develop a clearer sense of direction and purpose. To achieve their objectives, system leaders can use a governance compass that has five key points: Information. Boards must determine what they need to know, where to secure this information, and what form the information should take. Agenda. Boards must make reflective and intentional use of their agenda by reviewing and categorizing agenda items discussed in the past 12 months and establishing an agenda plan for the next 12 months. Structural mechanisms. Boards must decide structural issues such as relationships between system board and local boards, sizes of boards, and kinds of committees needed. Culture. Boards should reflect on their culture--values and traditions that have characterized them in the past--to assess whether changes are needed to strengthen or improve the culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Ketoconazole in experimental vaginal candidosis in rats

Rats in pseudoestrous were treated subcutaneously with ketoconazole at 25 mg/kg twice a day. In both uninfected and infected rats ketoconazole inhibited the cornification of the vaginal epithelium. Thus, ketoconazole, in addition to having an antifungal effect, may aid in the removal of candida by inhibiting the epithelial conditions suitable for hyphal invasion.

A morphological study of experimental rabbit staphylococcal endocarditis and aortitis. I. Formation and effect of infected and uninfected vegetations on the aorta

In this study the development of sterile thrombic vegetations on the aorta resulting from catheterization and the effect of subsequent infection with Staphylococcus aureus were examined by light and electron microscopy. Thrombi of various sizes, comprising fibrin, platelets and a few leucocytes and erythrocytes, develop on the damaged surface of the aorta with minimal changes in the underlying aortic wall. After intravenous inoculation of Staph. aureus most vegetations become infected, as shown by the presence of bacterial colonies, and the underlying aortic wall is markedly inflamed. The inflammatory cells invade the wall from the base of the aorta and cause swelling plus disruption of the elastic laminae with ulceration of the luminal surface in some cases. This structural damage appears to be a direct result of the bacterial infection of the lesions on the luminal surface.

Trusteeship: salvaging the myth of the governance role

A myth of trusteeship--that governance is the central role of board members--has been difficult for trustees to put into practice. The process of initiating new trustees implicitly communicates a set of largely unspoken practices that do not fulfill the myth. In actual practice, trustees find themselves involved in management, rather than governance. Although regulatory bodies, the courts, or a constituent can clarify the job of governance, trustees must call one another to action to reshape their practice and refurbish the myth with credibility. Trustees generally are expected to ensure quality of service and performance standards through governance, although many question their competence to do so. Since a direct link exists between a board's ability to evaluate itself and its ability to evaluate others, members first must learn to evaluate themselves in an open, verifiable manner. Trustees also must take account of the cyclical emphasis society places on private interests versus public issues, noting shifts in the cycle to identify and define board responsibilities. Members should act not as representatives of a single group but keep in touch with as many constituencies as possible. Though models are being developed to evaluate board performance and to chart management/governance functions, the most effective change in practice will come from within boards--through members' study and reflection. A board retreat that allows trustees to share information and examine principles of practice may facilitate this role definition.