Carboxylate Adsorption on Rutile TiO2(100): Role of Coulomb Repulsion, Relaxation, and Steric Hindrance.

Understanding the adsorption and photoactivity of acetic acid and trimethyl acetic acid on TiO2 surfaces is important for improving the performance of photocatalysts and dye-sensitized solar cells. Here we present a structural study of adsorption on rutile TiO2(100)-1 × 1 and -1 × 3 using Scanning Tunnelling Microscopy and Density Functional Theory calculations. Exposure of both terminations to acetic acid gives rise to a ×2 periodicity in the [001] direction (i.e., along Ti rows), with a majority ordered c(2 × 2) phase in the case of the 1 × 1 termination. The DFT calculations suggest that the preference of c(2 × 2) over the 2 × 1 periodicity found for TiO2(110)-1 × 1 can be attributed to an increase in interadsorbate Coulomb repulsion. Exposure of TiO2(100)-1 × 1 and -1 × 3 to trimethyl acetic acid gives rise to largely disordered structures due to steric effects, with quasi-order occurring in small areas and near step edges where these effects are reduced.

Computed tomographic description of the highly variable imaging features of equine oromaxillary sinus and oronasal fistulae.

Oronasal and oromaxillary sinus fistulae are well-documented complications following removal or loss of a maxillary cheek tooth. Diagnosis is currently based on a combination of oral examination, videoendoscopy, radiography, and computed tomography (CT). The objective of this retrospective, case series study was to describe the CT characteristics of confirmed oronasal and oromaxillary sinus fistulae in a group of horses. Inclusion criteria were a head CT acquired at the authors' hospital during the period of 2012-2017, a CT diagnosis of oronasal or oromaxillary sinus fistulae, and a confirmed diagnosis based on a method other than CT. Signalment, clinical findings, oral examination findings, presence of a confirmed fistula, and method for confirmation of the diagnosis were recorded. A veterinary radiologist reviewed CT studies for all included horses and recorded characteristics of the fistulae. Seventeen horses were sampled. Fourteen oromaxillary sinus fistulae and three oronasal fistulae were identified. All fistulae appeared as variably sized focal defects in the alveolar bone. Defects frequently contained a linear tract of heterogeneous material interspersed with gas bubbles, considered consistent with food. Computed tomographic attenuation of the material (Hounsfield units, HU) varied widely within and between cases. In 16 of 17 cases, there was evidence of concurrent dental disease in addition to the fistulae. Although the gold standard diagnostic test remains identification of feed material within the sinus or nasal passages, findings from the current study support the use of CT as an adjunctive diagnostic test for assessing the extent of involvement and presurgical planning.

Phase III study of gefitinib compared with intravenous methotrexate for recurrent squamous cell carcinoma of the head and neck [corrected].

PURPOSE: To compare survival in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN) treated with gefitinib 250 or 500 mg/day or standard methotrexate. PATIENTS AND METHODS: Four hundred eighty-six patients with recurrent SCCHN were randomly assigned to oral gefitinib 250 mg/day, gefitinib 500 mg/day, or methotrexate 40 mg/m(2) intravenously weekly. Primary end point was overall survival, secondary end points were objective response rate (ORR), safety, symptom improvement, and quality of life (QOL). Exploratory end points included association of efficacy with epidermal growth factor receptor gene copy number and other biomarkers. RESULTS: Neither gefitinib 250 nor 500 mg/day improved overall survival compared with methotrexate (hazard ratio [HR], 1.22; 95% CI, 0.95 to 1.57; P = .12; and HR, 1.12; 95% CI, 0.87 to 1.43; P = .39, respectively). In the gefitinib 250 mg/day, 500 mg/day, and methotrexate groups, respectively, median overall survival was 5.6, 6.0, and 6.7 months; ORRs (Response Evaluation Criteria in Solid Tumors) were 2.7%, 7.6% and 3.9%, with no statistically significant difference between either gefitinib arm and methotrexate. No unexpected adverse events were observed, except for tumor hemorrhage-type events with gefitinib (8.9%, gefitinib 250 mg/day; 11.4%, gefitinib 500 mg/day; 1.9%, methotrexate). QOL improvement rates (Functional Assessment of Cancer Therapy-Head & Neck total score) were 13.4%, 18.0%, and 6.0% for gefitinib 250 mg/day, 500 mg/day, and methotrexate, respectively. CONCLUSION: In patients with recurrent or metastatic SCCHN, while responses with gefitinib were seen, neither gefitinib 250 nor 500 mg/day improved overall survival compared with methotrexate. With the exception of tumor hemorrhage-type events with gefitinib, the adverse event profiles were generally consistent with those previously observed.

Clinical experience with gefitinib in Indian patients.

INTRODUCTION: Treatment options are limited in patients with advanced or refractory non-small cell lung cancer and lead to suboptimal outcome and/or benefit. The epidermal growth factor tyrosine kinase inhibitor gefitinib (IRESSA) has been approved in many countries. Increased responsiveness to gefitinib has been demonstrated in particular subsets of patients, for example never smokers and patients of Asian origin. However, to date, little is known of its use specifically in patients from India. METHODS: Retrospective ad hoc analysis of clinical data from experience with gefitinib in patients with advanced NSCLC from India enrolled in the IRESSA Survival Evaluation in Lung (ISEL) study (n = 77) or included in the gefitinib expanded-access program in India (n = 133). RESULTS: Among Indian patients enrolled in the ISEL study, median survival was 6.4 months with gefitinib and 5.1 month with placebo. The objective response rate in Indian patients was 14% with gefitinib versus 0% with placebo. In ISEL, tolerability data from Indian patients were consistent with the overall study population. In the Indian gefitinib expanded-access program, median survival was 6 months and gefitinib was well tolerated. CONCLUSIONS: Gefitinib seems well tolerated in Indian patients with advanced NSCLC, with some clinical benefit observed.