Adult tonsillectomy: An evaluation of indications and complications.

OBJECTIVE: This study aimed to evaluate current adult tonsillectomy indications along with risk factors associated with postoperative complications. METHODS: In this retrospective chart review, demographic, clinical, and surgical data were collected from 2004 to 2020 of adult patients who underwent tonsillectomy. Indications for surgery were categorized as infectious etiology, biopsy, obstructive sleep apnea (OSA), and tonsillar stones. Data regarding postoperative hemorrhage, emergency department (ED) visits, and readmissions were collected. Multivariable logistic regression models were used to evaluate factors associated with postoperative complications. RESULTS: 574 adults (mean age 32 years, 69.9% F vs. 30.1% M) were included. The most common indication was infections (62.2%), followed by biopsy (26.5%), tonsillar stones (6.8%), and OSA (4.5%). The highest frequency of postoperative bleeds (17.9%) occurred in the tonsillar stones cohort; however, the indication for surgery was not a significant predictor on multivariate analysis. Male sex and younger age were independent predictors of postoperative bleeding, while younger age was a significant predictor of postoperative ED visits. There was a significant linear trend of an increasing proportion of tonsillectomies performed for tonsillar stones compared to other indications for 2011-2019. CONCLUSION: Infectious etiology was the most common indication for tonsillectomy. Indication for surgery was not a significant predictor of postoperative bleeding; however, male sex and younger age had higher odds of postoperative bleeding. The proportion of tonsillectomies performed for tonsillar stones was steadily increasing.

Income is an independent risk factor for worse asthma outcomes.

BACKGROUND: Socioeconomic status (SES) is associated with asthma morbidity in observational studies, but the factors underlying this association are uncertain. OBJECTIVE: We investigated whether 3 SES correlates-low income, low education, and high perceived stress-were independent risk factors for treatment failure and asthma exacerbations in the context of a randomized controlled trial. METHODS: The effect of low SES (household income of <$50,000/y and household educational level of less than a Bachelor's degree) and high perceived stress (defined as a score of >20 on a perceived stress scale) on asthma morbidity was analyzed in 381 participants by using Poisson regression models. The primary outcome was treatment failure (defined in the trial protocol as a significant clinical or airflow deterioration), and the secondary outcome was asthma exacerbations requiring systemic corticosteroids. RESULTS: Fifty-four percent of participants had a low income, 40% had a low educational level, and 17% had high perceived stress levels. Even after adjusting for race and other important confounders, participants with lower income had higher rates of both treatment failures (rate ratio, 1.6; 95% CI, 1.1-2.3; P = .03) and exacerbations (rate ratio, 1.9; 95% CI, 1.1-3.3; P = .02). Adherence with inhaled corticosteroids was similarly high for both income categories. Education and perceived stress were not significantly associated with either outcome. CONCLUSIONS: In the context of a randomized controlled trial, participants with lower income were more likely to experience adverse asthma outcomes independent of education, perceived stress, race, and medication adherence.

Race is associated with differences in airway inflammation in patients with asthma.

BACKGROUND: African American subjects have a greater burden from asthma compared with white subjects. Whether the pattern of airway inflammation differs between African American and white subjects is unclear. OBJECTIVE: We sought to compare sputum airway inflammatory phenotypes of African American and white subjects treated or not with inhaled corticosteroids (ICSs; ICS+ and ICS-, respectively). METHODS: We performed a secondary analysis of self-identified African American and white subjects with asthma enrolled in clinical trials conducted by the National Heart, Lung, and Blood Institute-sponsored Asthma Clinical Research Network and AsthmaNet. Demographics, clinical characteristics, and sputum cytology after sputum induction were examined. We used a sputum eosinophil 2% cut point to define subjects with either an eosinophilic (≥2%) or noneosinophilic (<2%) inflammatory phenotype. RESULTS: Among 1018 participants, African American subjects (n = 264) had a lower FEV1 percent predicted (80% vs 85%, P < .01), greater total IgE levels (197 vs 120 IU/mL, P < .01), and a greater proportion with uncontrolled asthma (43% vs 28%, P < .01) compared with white subjects (n = 754). There were 922 subjects in the ICS+ group (248 African American and 674 white subjects) and 298 subjects in the ICS- group (49 African American and 249 white subjects). Eosinophilic airway inflammation was not significantly different between African American and white subjects in either group (percentage with eosinophilic phenotype: ICS+ group: 19% vs 16%, P = .28; ICS- group: 39% vs 35%, P = .65; respectively). However, when adjusted for confounding factors, African American subjects were more likely to exhibit eosinophilic airway inflammation than white subjects in the ICS+ group (odds ratio, 1.58; 95% CI, 1.01-2.48; P = .046) but not in the ICS- group (P = .984). CONCLUSION: African American subjects exhibit greater eosinophilic airway inflammation, which might explain the greater asthma burden in this population.

Predictors of response to tiotropium versus salmeterol in asthmatic adults.

BACKGROUND: Tiotropium has activity as an asthma controller. However, predictors of a positive response to tiotropium have not been described. OBJECTIVE: We sought to describe individual and differential responses of asthmatic patients to salmeterol and tiotropium when added to an inhaled corticosteroid, as well as predictors of a positive clinical response. METHODS: Data from the double-blind, 3-way, crossover National Heart, Lung, and Blood Institute's Asthma Clinical Research Network's Tiotropium Bromide as an Alternative to Increased Inhaled Glucocorticoid in Patients Inadequately Controlled on a Lower Dose of Inhaled Corticosteroid (ClinicalTrials.gov number, NCT00565266) trial were analyzed for individual and differential treatment responses to salmeterol and tiotropium and predictors of a positive response to the end points FEV1, morning peak expiratory flow (PEF), and asthma control days (ACDs). RESULTS: Although approximately equal numbers of patients showed a differential response to salmeterol and tiotropium in terms of morning PEF (n = 90 and 78, respectively) and ACDs (n = 49 and 53, respectively), more showed a differential response to tiotropium for FEV1 (n = 104) than salmeterol (n = 62). An acute response to a short-acting bronchodilator, especially albuterol, predicted a positive clinical response to tiotropium for FEV1 (odds ratio, 4.08; 95% CI, 2.00-8.31; P < .001) and morning PEF (odds ratio, 2.12; 95% CI, 1.12-4.01; P = 0.021), as did a decreased FEV1/forced vital capacity ratio (FEV1 response increased 0.39% of baseline for every 1% decrease in FEV1/forced vital capacity ratio). Higher cholinergic tone was also a predictor, whereas ethnicity, sex, atopy, IgE level, sputum eosinophil count, fraction of exhaled nitric oxide, asthma duration, and body mass index were not. CONCLUSION: Although these results require confirmation, predictors of a positive clinical response to tiotropium include a positive response to albuterol and airway obstruction, factors that could help identify appropriate patients for this therapy.

Demonstration of Physicochemical and Functional Similarity of the Biosimilar BAT1806/BIIB800 to Reference Tocilizumab.

BACKGROUND AND OBJECTIVE: Tocilizumab is an immunoglobulin G1 monoclonal antibody targeting the interleukin-6 receptor (IL-6R). BAT1806/BIIB800 (tocilizumab-bavi) has been developed as a biosimilar to the reference product tocilizumab (TCZ). The objective of this study was to demonstrate physicochemical and functional similarity between BAT1806/BIIB800 and TCZ in a comprehensive comparability exercise. METHODS: A comprehensive panel of over 20 methods was used to generate datasets comparing critical and non-critical product quality attributes for 10 BAT1806/BIIB800 lots and 44 TCZ lots (16 sourced from China, 16 from the EU, and 12 from the US). Primary structure, higher-order structure, and physicochemical properties were assessed using liquid chromatography, mass spectrometry, various spectroscopy techniques/methods, capillary electrophoresis, and thermoanalytical techniques. Fragment antigen-binding (Fab)- and fragment crystallizable (Fc)-mediated biological properties were assessed using cell-based assays, immunoassays, flow cytometry, and kinetic binding assays. RESULTS: BAT1806/BIIB800 and TCZ (irrespective of source) were shown to be similar in terms of structural and functional properties. No differences were observed in terms of the most critical quality attributes, that is, soluble-IL-6R binding and inhibition of IL-6-mediated cell proliferation. BAT1806/BIIB800 and TCZ demonstrated similarity in terms of Fab- and Fc-mediated binding and biological activity. Minor differences were observed in glycosylation (afucosylation and sialylation), glycation, aggregation, and charge variants, which were demonstrated to be not clinically relevant. CONCLUSION: BAT1806/BIIB800 and TCZ were highly similar for all critical quality attributes. Where differences were observed in less critical quality attributes, additional analytical assessments and clinical study results determined these to be not clinically meaningful.

Tiotropium bromide step-up therapy for adults with uncontrolled asthma.

BACKGROUND: Long-acting beta-agonist (LABA) therapy improves symptoms in patients whose asthma is poorly controlled by an inhaled glucocorticoid alone. Alternative treatments for adults with uncontrolled asthma are needed. METHODS: In a three-way, double-blind, triple-dummy crossover trial involving 210 patients with asthma, we evaluated the addition of tiotropium bromide (a long-acting anticholinergic agent approved for the treatment of chronic obstructive pulmonary disease but not asthma) to an inhaled glucocorticoid, as compared with a doubling of the dose of the inhaled glucocorticoid (primary superiority comparison) or the addition of the LABA salmeterol (secondary noninferiority comparison). RESULTS: The use of tiotropium resulted in a superior primary outcome, as compared with a doubling of the dose of an inhaled glucocorticoid, as assessed by measuring the morning peak expiratory flow (PEF), with a mean difference of 25.8 liters per minute (P<0.001) and superiority in most secondary outcomes, including evening PEF, with a difference of 35.3 liters per minute (P<0.001); the proportion of asthma-control days, with a difference of 0.079 (P=0.01); the forced expiratory volume in 1 second (FEV1) before bronchodilation, with a difference of 0.10 liters (P=0.004); and daily symptom scores, with a difference of -0.11 points (P<0.001). The addition of tiotropium was also noninferior to the addition of salmeterol for all assessed outcomes and increased the prebronchodilator FEV1 more than did salmeterol, with a difference of 0.11 liters (P=0.003). CONCLUSIONS: When added to an inhaled glucocorticoid, tiotropium improved symptoms and lung function in patients with inadequately controlled asthma. Its effects appeared to be equivalent to those with the addition of salmeterol. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT00565266.).

Predictors of Quality of Life for Head and Neck Cancer Patients at an Academic Institution.

Objective: Quality of life (QOL) is an important consideration in head and neck cancer (HNC) due to lasting disease and treatment-related toxicities. We performed a comprehensive review of predictors of QOL in this population, including distance to care. Study Design: Retrospective cohort study from 2017 to 2022. Setting: Academic medical center. Methods: QOL was quantified in patients treated for HNC utilizing the University of Washington Quality of Life and 20-Item Short Form surveys completed at subsequent clinic visits. Distance to treatment center and other demographic, socioeconomic, disease-specific, and behavioral data were analyzed. Results: There were 176 patients in the cohort (69% male; mean age, 64 ± 10.8 years). There was no association between miles traveled and any of the QOL subscales. Marital status was the strongest predictor of QOL, significantly associated with 7/8 QOL domains and favoring those who were married. Other significant predictors of decreased QOL included emotional/physical abuse, current tobacco use, documented religious affiliation, and treatment involving surgery plus adjuvant therapy. A significant positive trend over time existed for multiple QOL subscales. Conclusion: QOL is unchanged in patients who travel greater distances for care. QOL is more closely linked to factors such as marital status, physical/emotional abuse, tobacco use, religious affiliation, treatment intensity, and time following surgery. This highlights the importance of a strong support structure and the influence of certain socioeconomic and lifestyle factors on patients, with opportunities for screening and intervention throughout their cancer care.

Comparison of physician-, biomarker-, and symptom-based strategies for adjustment of inhaled corticosteroid therapy in adults with asthma: the BASALT randomized controlled trial.

CONTEXT: No consensus exists for adjusting inhaled corticosteroid therapy in patients with asthma. Approaches include adjustment at outpatient visits guided by physician assessment of asthma control (symptoms, rescue therapy, pulmonary function), based on exhaled nitric oxide, or on a day-to-day basis guided by symptoms. OBJECTIVE: To determine if adjustment of inhaled corticosteroid therapy based on exhaled nitric oxide or day-to-day symptoms is superior to guideline-informed, physician assessment-based adjustment in preventing treatment failure in adults with mild to moderate asthma. DESIGN, SETTING, AND PARTICIPANTS: A randomized, parallel, 3-group, placebo-controlled, multiply-blinded trial of 342 adults with mild to moderate asthma controlled by low-dose inhaled corticosteroid therapy (n = 114 assigned to physician assessment-based adjustment [101 completed], n = 115 to biomarker-based [exhaled nitric oxide] adjustment [92 completed], and n = 113 to symptom-based adjustment [97 completed]), the Best Adjustment Strategy for Asthma in the Long Term (BASALT) trial was conducted by the Asthma Clinical Research Network at 10 academic medical centers in the United States for 9 months between June 2007 and July 2010. INTERVENTIONS: For physician assessment-based adjustment and biomarker-based (exhaled nitric oxide) adjustment, the dose of inhaled corticosteroids was adjusted every 6 weeks; for symptom-based adjustment, inhaled corticosteroids were taken with each albuterol rescue use. MAIN OUTCOME MEASURE: The primary outcome was time to treatment failure. RESULTS: There were no significant differences in time to treatment failure. The 9-month Kaplan-Meier failure rates were 22% (97.5% CI, 14%-33%; 24 events) for physician assessment-based adjustment, 20% (97.5% CI, 13%-30%; 21 events) for biomarker-based adjustment, and 15% (97.5% CI, 9%-25%; 16 events) for symptom-based adjustment. The hazard ratio for physician assessment-based adjustment vs biomarker-based adjustment was 1.2 (97.5% CI, 0.6-2.3). The hazard ratio for physician assessment-based adjustment vs symptom-based adjustment was 1.6 (97.5% CI, 0.8-3.3). CONCLUSION: Among adults with mild to moderate persistent asthma controlled with low-dose inhaled corticosteroid therapy, the use of either biomarker-based or symptom-based adjustment of inhaled corticosteroids was not superior to physician assessment-based adjustment of inhaled corticosteroids in time to treatment failure. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00495157.

Feasibility of same day surgery for pediatric second branchial cleft anomalies.

OBJECTIVE: The risk of expansile hematoma and airway compromise following neck surgery have been used to validate overnight observation. We investigated the outcomes of pediatric patients undergoing a removal of second branchial cleft anomalies (BCA) via either same day surgery or overnight observation. METHODS: A retrospective review of patients undergoing second BCA removal between January 1, 2008 to January 1, 2019 was performed. 40 cases were identified for review. Bivariate analyses were performed to determine predictive factors for overnight admission as well as associations between overnight observation and adverse outcomes (hematoma, seroma, airway compromise, infection). Factors evaluated for analysis included ASA class, surgeon type, history of pre-operative infection, recurrent case, operation >90 min, pharyngeal violation, intraoperative cyst rupture, cyst size, and drain placement. RESULTS: There were no life-threatening adverse events. Same day discharge was not associated with adverse events (p = 0.24). Overnight observation was associated with a history of preoperative infection (p = 0.003), cyst > 3.0 cm (p = 0.046), operative time > 90 min (p < 0.001), and drain placement (p = 0.001). There was no association between other investigated variables and adverse events or overnight stay. CONCLUSION: Same day discharge following second branchial cleft anomalies appears safe and feasible. Further study is needed to determine the safety profile of same day discharge and etiologies of practice patterns of overnight observation.

Myosin Va binding to neurofilaments is essential for correct myosin Va distribution and transport and neurofilament density.

The identification of molecular motors that modulate the neuronal cytoskeleton has been elusive. Here, we show that a molecular motor protein, myosin Va, is present in high proportions in the cytoskeleton of mouse CNS and peripheral nerves. Immunoelectron microscopy, coimmunoprecipitation, and blot overlay analyses demonstrate that myosin Va in axons associates with neurofilaments, and that the NF-L subunit is its major ligand. A physiological association is indicated by observations that the level of myosin Va is reduced in axons of NF-L-null mice lacking neurofilaments and increased in mice overexpressing NF-L, but unchanged in NF-H-null mice. In vivo pulse-labeled myosin Va advances along axons at slow transport rates overlapping with those of neurofilament proteins and actin, both of which coimmunoprecipitate with myosin Va. Eliminating neurofilaments from mice selectively accelerates myosin Va translocation and redistributes myosin Va to the actin-rich subaxolemma and membranous organelles. Finally, peripheral axons of dilute-lethal mice, lacking functional myosin Va, display selectively increased neurofilament number and levels of neurofilament proteins without altering axon caliber. These results identify myosin Va as a neurofilament-associated protein, and show that this association is essential to establish the normal distribution, axonal transport, and content of myosin Va, and the proper numbers of neurofilaments in axons.

Does acuity matter?--Optimal timing of tracheostomy stratified by injury severity.

BACKGROUND: A number of conflicting studies have been conducted to analyze the relationship between the timing of tracheostomy and mortality, intensive care unit (ICU) length of stay (LOS), hospital LOS, and the incidence of pneumonia. In contrast to previous studies, this relationship was investigated in the context of expected survival based on probability of survival (Ps) greater than 25%. METHODS: Trauma patients were screened using a statewide registry during a 5-year period (January 2001 to December 2005). Burn patients, transfer patients, permanent tracheostomies, and patients who underwent multiple surgical airways were excluded from the study. Data were collected on patient demographics, Trauma and Injury Severity Score, days to tracheostomy, mortality, ICU LOS, total ventilator days, pneumonia, and hospital LOS. STATISTICAL ANALYSES: log-linear modeling, chi2, p < 0.05. RESULTS: A total of 125,533 trauma patients were analyzed. Out of these, 82,148 patients met inclusion criteria and had complete data for analysis. There were 6,880 patients intubated at the scene, during transport, or at admission to the emergency department, with 685 receiving a temporary tracheostomy. There was a significantly higher mortality rate (48.9%) associated with patients with low Ps (<0.25) receiving early tracheostomy (ET), <4 days. Among high-Ps patients, the ET group demonstrated reduced ICU LOS, total ventilator days, pneumonia, and hospital LOS (p < 0.05). CONCLUSION: ET in patients with low Ps may not be beneficial given the substantially high mortality rate before post injury day 4. However, ET in high-Ps patients reduces ICU and hospital LOS, total ventilator days, and the incidence of pneumonia. This suggests an increased benefit in ET to trauma patients with high Ps.

A simple, bead-based approach for multi-SNP molecular haplotyping.

Single nucleotide polymorphisms (SNPs) within a gene region have often been studied to determine their effect on phenotype. Although a single base pair change can produce a phenotypic change, phenotype is often influenced by the presence of multiple polymorphisms and their relative positions within a given region. For example, if multiple changes occur in a promoter region, how they influence gene expression will depend on their cis/trans configuration. As such, it is essential to consider the haplotype, or the alignment of multiple SNP alleles on each chromosome when attempting to associate genomic changes with phenotype. Unfortunately, no method of high-throughput molecular haplotyping of multiple SNPs currently exists. In response to this unmet need, we have developed an inexpensive, reliable bead-based capture-based haplotyping (CBH) assay to determine the phase, or haplotype, of multiple SNP alleles in a high-throughput manner. The CBH assay requires minimal setup and handling, requires no centrifugation steps and can be performed in <1 h. Data collection is performed via flow cytometry and the assay yields plus/minus results allowing for automated calling by a simple computer application. We will present data demonstrating the molecular haplotyping of 11 SNPs within exon 2 of the N-acetyltransferase-2 (NAT2) gene, which expresses an important drug-metabolizing enzyme. This assay has applications in diagnostic testing, promoter analysis, association studies and pharmacogenetic analysis.

Serum osteoprotegerin levels in healthy controls and cancer patients.

PURPOSE: Osteoprotegerin (OPG) is a novel secreted member of the tumor necrosis factor receptor superfamily. In vitro, OPG blocks osteoclastogenesis in a dose-dependent manner. Serum OPG levels were assayed in cancer patients and healthy control subjects using an ELISA. RESULTS: OPG levels in healthy controls were significantly higher in sera (0.17 ng/ml) than in plasma (0.14 ng/ml). OPG levels did not differ by age in either control group. Serum was available from patients with solid tumors (n = 145), hematological malignancies (n = 111), benign hematological disorders (n = 35), and rheumatologic diseases (n = 60). When adjusted for age and sex, there was no significant OPG elevation in the sera of patients with solid tumors compared with controls (0.2 versus 0.18 ng/ml). When analyzed by site of primary malignancy within the solid tumor patient group, serum OPG elevations were observed only in patients with colorectal cancer (0.29 ng/ml; P < 0.0001) and pancreatic cancer (0.35 ng/ml; P < 0.0001). When analyzed by site of metastasis within the solid tumor patient group, significant elevations in serum OPG were observed only in patients with liver metastases (0.29 ng/ml) and soft tissue metastases (0.21 ng/ml) but not in patients with bone or lung metastases. Within the hematological malignancy group, serum levels of OPG were significantly lower in patients with multiple myeloma (0.12 ng/ml) but were elevated in patients with Hodgkin's disease (0.29 ng/ml) and Non-Hodgkin's Lymphoma (0.24 ng/ml; P = 0.048). CONCLUSIONS: Although some patients with malignancy have significant elevations of circulating OPG, these concentrations do not approach the level that would be expected to suppress osteoclast function.

Affinity capillary electrophoresis for the screening of novel antimicrobial targets.

The increasing number of multiantibiotic-resistant organisms, including methicillin-resistant Staphylococcus aureus (MRSA), requires the development of novel chemotherapies that are structurally distinct and exempt from current resistance mechanisms. Bioinformatics data mining of microbial genomes has revealed numerous previously unexploited essential open reading frames (ORFs) of unknown biochemical function. The potential of these proteins as screening targets is not readily apparent because most screening technologies rely on knowledge of biological function. To address this problem, the authors employed affinity capillary electrophoresis (ACE) to identify antimicrobial compounds that bound the novel target YihA. Screening a small-molecule library of 44,000 compounds initially identified 115 binders, of which 76% were confirmed. Furthermore, the ACE assay distinguished diverse compounds that possessed drug-like properties and antimicrobial activity against drug-resistant clinical isolates. These data validate ACE as a valuable tool for the fast, efficient detection of specific binding molecules that possess biological activity.

Restoration of estrogen responsiveness by blocking the HER-2/neu pathway.

HER-2/neu gene amplification or protein overexpression is evident in 20-30% of primary breast cancers. Its amplification correlates with poor prognosis. There appears to be an association between HER-2/neu overexpression and estrogen independence. The MCF-7 human breast carcinoma cell line is estrogen-dependent and sensitive to the anti-estrogen, tamoxifen (TAM). This line, when transfected with the HER-2/neu gene, becomes estrogen-independent and resistant to TAM. Blockade of the HER-2/neu receptor with 1-5 nM of the humanized HER-2/neu antibody, Herceptin, restored estrogen, as well as TAM, sensitivity. These results suggest that Herceptin or similar drugs may restore estrogen sensitivity and the administration of a HER-2/neu inhibitor with an anti-estrogen to premenopausal patients should be considered.

Decreased response to paclitaxel versus docetaxel in HER-2/neu transfected human breast cancer cells.

Taxanes are effective in the treatment of metastatic breast cancer. Docetaxel has been shown to be more potent than paclitaxel in inducing bcl-2 phosphorylation and apoptosis and is clinically active in some paclitaxel-resistant breast tumors. HER-2/neu overexpression has been shown to correlate with resistance to hormonal therapy as well as chemotherapy. Using a HER-2/neu transfected MCF-7 human breast cancer cell line, we investigated the role of HER-2/neu overexpression on resistance to paclitaxel and docetaxel treatment. A control vector transfected MCF-7 human breast cancer cell line (MCF/neo) and a HER-2/neu transfected MCF-7 line (MCF/18) were treated with various concentrations of docetaxel or paclitaxel. Cell number was assessed using the MTT tetrazolium dye assay. In the control vector transfected MCF/neo cell line, paclitaxel and docetaxel gave similar dose-dependent growth inhibition ( p = 0.175). In HER-2/neu transfected MCF/18 cells, docetaxel treatment resulted in a dose-dependent inhibition similar to that seen in MCF/neo cells. Paclitaxel, however, gave significantly less growth inhibition than docetaxel in the HER-2/neu overexpressing MCF/18 cells (p = 0.0003). These data suggest that HER-2/neu overexpression may contribute to paclitaxel resistance. In contrast, the cytotoxic effects of docetaxel in these breast carcinoma cells are not affected by HER-2/neu expression. Therefore, docetaxel may be the preferred taxane therapy in HER-2/neu overexpressing breast tumors.

Structures of adnectin/protein complexes reveal an expanded binding footprint.

Adnectins are targeted biologics derived from the tenth type III domain of human fibronectin (¹°Fn3), a member of the immunoglobulin superfamily. Target-specific binders are selected from libraries generated by diversifying the three ¹°Fn3 loops that are analogous to the complementarity determining regions of antibodies. The crystal structures of two Adnectins were determined, each in complex with its therapeutic target, EGFR or IL-23. Both Adnectins bind different epitopes than those bound by known monoclonal antibodies. Molecular modeling suggests that some of these epitopes might not be accessible to antibodies because of the size and concave shape of the antibody combining site. In addition to interactions from the Adnectin diversified loops, residues from the N terminus and/or the ß strands interact with the target proteins in both complexes. Alanine-scanning mutagenesis confirmed the calculated binding energies of these ß strand interactions, indicating that these nonloop residues can expand the available binding footprint.

A fibronectin scaffold approach to bispecific inhibitors of epidermal growth factor receptor and insulin-like growth factor-I receptor.

Engineered domains of human fibronectin (Adnectins™) were used to generate a bispecific Adnectin targeting epidermal growth factor receptor (EGFR) and insulin-like growth factor-I receptor (IGF-IR), two transmembrane receptors that mediate proliferative and survival cell signaling in cancer. Single-domain Adnectins that specifically bind EGFR or IGF-IR were generated using mRNA display with a library containing as many as 10 ( 13) Adnectin variants. mRNA display was also used to optimize lead Adnectin affinities, resulting in clones that inhibited EGFR phosphorylation at 7 to 38 nM compared to 2.6 µM for the parental clone. Individual, optimized, Adnectins specific for blocking either EGFR or IGF-IR signaling were engineered into a single protein (EI-Tandem Adnectin). The EI-Tandems inhibited phosphorylation of EGFR and IGF-IR, induced receptor degradation, and inhibited down-stream cell signaling and proliferation of human cancer cell lines (A431, H292, BxPC3 and RH41) with IC 50 values ranging from 0.1 to 113 nM. Although Adnectins bound to EGFR at a site distinct from those of anti-EGFR antibodies cetuximab, panitumumab and nimotuzumab, like the antibodies, the anti-EGFR Adnectins blocked the binding of EGF to EGFR. PEGylated EI-Tandem inhibited the growth of both EGFR and IGF-IR driven human tumor xenografts, induced degradation of EGFR, and reduced EGFR phosphorylation in tumors. These results demonstrate efficient engineering of bispecific Adnectins with high potency and desired specificity. The bispecificity may improve biological activity compared to monospecific biologics as tumor growth is driven by multiple growth factors. Our results illustrate a technological advancement for constructing multi-specific biologics in cancer therapy.

Efficacy of standard doses of Ibuprofen alone, alternating, and combined with acetaminophen for the treatment of febrile children.

BACKGROUND: Many pediatricians recommend, and many parents administer, alternating or combined doses of ibuprofen and acetaminophen for fever. Limited data support this practice with standard US doses. OBJECTIVE: This study compared the antipyretic effect of 3 different treatment regimens in children, using either ibuprofen alone, ibuprofen combined with acetaminophen, or ibuprofen followed by acetaminophen over a single 6-hour observation period. METHODS: Febrile episodes from children aged 6 to 84 months were randomized into the 3 treatment groups: a single dose of ibuprofen at the beginning of the observation period; a single dose of ibuprofen plus a single dose of acetaminophen at the beginning of the observation period; or ibuprofen followed by acetaminophen 3 hours later. Ibuprofen was administered at 10 mg/kg; acetaminophen at 15 mg/kg. Temperatures were measured hourly for 6 hours using a temporal artery thermometer. The primary outcome was temperature difference between treatment groups. Adverse-event data were not collected in this single treatment period study. RESULTS: Sixty febrile episodes in 46 children were assessed. The mean (SD) age of the children was 3.4 (2.2) years, and 31 (51.7%) were girls. Differences among temperature curves were significant (P < 0.001; the combined and alternating arms had significantly better antipyresis compared with the ibuprofen-alone group at hours 4 to 6 (hour 4, P < 0.005; hours 5 and 6, P < 0.001). All but one of the children in the combined and alternating groups were afebrile at hours 4, 5, and 6. In contrast, for those receiving ibuprofen alone, 30%, 40%, and 50% had temperatures >38.0 °C at hours 4, 5, and 6, respectively (hour 4, P = 0.002; hours 5 and 6, P < 0.001). CONCLUSION: During a single 6-hour observation period for these participating children, combined and alternating doses of ibuprofen and acetaminophen provided greater antipyresis than ibuprofen alone at 4 to 6 hours. ClinicalTrials.gov identifier: NCT00267293.