Scalable all-fiber coherent beam combination using digital control.

This paper describes a filled-aperture coherent beam combining (CBC) system based on locking of optical coherence via single-detector electronic-frequency tagging (LOCSET). The sensing and control architecture is implemented using a field-programmable gate array and high-bandwidth electro-optic phase modulators. The all-fiber optical configuration consists of a narrow linewidth 1560 nm seed laser separated into three channels, each containing 7 W erbium-doped fiber amplifiers. The system was demonstrated experimentally, achieving a total stabilized output power of 20 W, a combination efficiency greater than 95%, and an output RMS phase stability of λ/493. As this architecture employs an entirely digital sensing and control scheme based on LOCSET, it presents a highly scalable and cost-effective solution for CBC that is wavelength agnostic and can support an arbitrarily large number of channels.

High-Precision Quantum-Enhanced Gravimetry with a Bose-Einstein Condensate.

We show that the inherently large interatomic interactions of a Bose-Einstein condensate (BEC) can enhance the sensitivity of a high precision cold-atom gravimeter beyond the shot-noise limit (SNL). Through detailed numerical simulation, we demonstrate that our scheme produces spin-squeezed states with variances up to 14 dB below the SNL, and that absolute gravimetry measurement sensitivities between two and five times below the SNL are achievable with BECs between 10^{4} and 10^{6} in atom number. Our scheme is robust to phase diffusion, imperfect atom counting, and shot-to-shot variations in atom number and laser intensity. Our proposal is immediately achievable in current laboratories, since it needs only a small modification to existing state-of-the-art experiments and does not require additional guiding potentials or optical cavities.

All-optical low noise fiber Bragg grating microphone.

We present an all-fiber design for a microphone using a fiber Bragg grating Fabry-Perot resonator attached to a diaphragm transducer. We analytically model and verify the fiber-diaphragm mechanical interaction, using the Hänsch-Couillaud readout technique to provide necessary sensitivity. We achieved a noise-equivalent strain sensitivity of 7.1×10-12 ϵ/Hz, which corresponds to a sound pressure of 74 µPa/Hz at 1 kHz limited by laser frequency noise and yielding a signal-to-noise ratio of 47±2 dB with a 1 Pa drive at 1 kHz, in close agreement with modeled results.

External cavity diode lasers with 5kHz linewidth and 200nm tuning range at 1.55µm and methods for linewidth measurement.

Two simple external cavity diode laser designs using fibre pigtailed gain chips are tested and their properties compared with a high end DBR fibre laser. These ECDLs demonstrate a FWHM linewidth as low as 5.2kHz with a fitted Lorentzian FWHM linewidth as low as 1.6kHz. Tuning ranges of 200nm covering 1420nm to 1620nm were demonstrated. To the best of our knowledge these are the narrowest linewidth and most broadly tunable external cavity diode lasers reported to date. The improvement in linewidth is attributed to greatly enhanced acoustic isolation allowed by using fiber coupled gain chips and by replacing kinematic mounts with a pair of rotatable wedges for cavity alignment which eliminates acoustic resonances. A detailed description and discussion of techniques used to characterize the frequency noise and linewidths of these lasers is provided.

Dentin matrix protein 1 (DMP1) signals via cell surface integrin.

Dentin matrix phosphoprotein 1 (DMP1) is a non-collagenous, acidic extracellular matrix protein expressed chiefly in bone and dentin. We examined the DMP1 ability to engage cell-surface receptors and subsequently activate intracellular signaling pathways. Our data indeed show that the presence of extracellular DMP1 triggers focal adhesion point formation in human mesenchymal stem cells and osteoblast-like cells. We determine that DMP1 acts via interaction with αvß3 integrin and stimulates phosphorylation of focal adhesion kinase. Further biochemical characterization confirms the activation of downstream effectors of the MAPK pathways, namely ERK and JNK, after DMP1 treatment. This activation is specifically inhibitable and can also be blocked by the addition of anti-αvß3 integrin antibody. Furthermore, we show that extracellular treatment with DMP1 stimulates the translocation of phosphorylated JNK to the nucleus and a concomitant up-regulation of transcriptional activation by phosphorylated c-Jun. The evidence presented here indicates that DMP1 is specifically involved in signaling via extracellular matrix-cell surface interaction. Combined with the published DMP1-null data (Feng, J. Q., Ward, L. M., Liu, S., Lu, Y., Xie, Y., Yuan, B., Yu, X., Rauch, F., Davis, S. I., Zhang, S., Rios, H., Drezner, M. K., Quarles, L. D., Bonewald, L. F., and White, K. E. (2006) Nat. Genet. 38, 1310-1315) it can be hypothesized that DMP1 could be a key effector of ECM-osteocyte signaling.

Human masseter muscle fiber type properties, skeletal malocclusions, and muscle growth factor expression.

PURPOSE: We identified masseter muscle fiber type property differences in subjects with dentofacial deformities. PATIENTS AND METHODS: Samples of masseter muscle were collected from 139 young adults during mandibular osteotomy procedures to assess mean fiber areas and percent tissue occupancies for the 4 fiber types that comprise the muscle. Subjects were classified into 1 of 6 malocclusion groups based on the presence of a skeletal Class II or III sagittal dimension malocclusion and either a skeletal open, deep, or normal bite vertical dimension malocclusion. In a subpopulation, relative quantities of the muscle growth factors IGF-I and GDF-8 gene expression were quantified by real-time polymerase chain reaction. RESULTS: Fiber properties were not different in the sagittal malocclusion groups, but were very different in the vertical malocclusion groups (P ≤ .0004). There were significant mean fiber area differences for type II (P ≤ .0004) and type neonatal-atrial (P = .001) fiber types and for fiber percent occupancy differences for both type I-II hybrid fibers and type II fibers (P ≤ .0004). Growth factor expression differed by gender for IGF-I (P = .02) and GDF-8 (P < .01). The ratio of IGF-I:GDF-8 expression associates with type I and II mean fiber areas. CONCLUSION: Fiber type properties are very closely associated with variations in vertical growth of the face, with statistical significance for overall comparisons at P ≤ .0004. An increase in masseter muscle type II fiber mean fiber areas and percent tissue occupancies is inversely related to increases in vertical facial dimension.

Practitioner and patient perceptions of orthodontic treatment: is the patient always right?

PURPOSE: As dentists embrace evidence-based clinical practice, we place increased emphasis on patient values. Standards like Angle Classification are not related to patient perceptions of the tangible benefits of treatment. This study quantifies the differences dentists and patients perceive in orthodontic treatment outcome. MATERIALS AND METHODS: A survey is used to quantify a patient's perception of orthodontic treatment. It was completed by 30 patients who completed treatment at the University of Pittsburgh School of Dental Medicine. Their responses were compared with the perceptions of five orthodontists, three general dentists, and two prosthodontists. RESULTS: Multivariate analysis of variance found the differences between and within the subjects to be significant at p < 0.004. Univariate analysis of variance of the initial scores showed the data to be significant at p < 0.002 and pairwise comparisons showed significant mean differences. Final score analysis of variance was significant at p < 0.001 and pairwise comparison showed significant mean differences. CONCLUSIONS: Patients and general dentists have a significantly less favorable initial perception of their dental esthetics and function when compared with orthodontists. Final scores of esthetic and functional perceptions between the patients and all three dentist groups showed significant differences, with patients perceiving the results of their treatment more favorably than practitioners. CLINICAL SIGNIFICANCE: The data herein elucidates differences in the value systems of professionals and patients. It is meant to encourage dentists to consider whether these differences justify the persistence of traditional orthodontic treatment goals or if treatment planning should incorporate consideration of each individual patient's preferences to maximize utility.

Overcoming barriers to tobacco cessation counselling in dental students.

PURPOSE: Tobacco use screening and brief intervention is recognised as an effective available preventive health service; yet, this service is still not routinely offered to dental patients by clinicians, despite dental schools generally providing some form of tobacco cessation counselling (TCC) by including it in their dental curriculum. A pilot study was therefore carried out to more clearly identify barriers that prevented the delivery of this service to tobacco-using patients at the University of Pittsburgh School of Dental Medicine and educational initiatives that might overcome these barriers. MATERIALS AND METHODS: A survey of faculty and students asked participants to rank their knowledge, preparation and comfort levels in performing TCC as well as their belief as to the importance of such training in the dental curriculum. Six months following training and practice opportunities, surveys were again administered to participants. Each individual's pre- and post-TCC training surveys were reviewed and difference in response to each item was calculated. RESULTS: The results of the present study show that students feel more prepared, that the time required to provide TCC was less than anticipated and that training in TCC is an important part of dental education to a greater extent after the pilot study than before. CONCLUSIONS: TCC training and practice opportunities for clinical application were effective in this pilot study in improving students' attitudes towards cited barriers.

In-vitro evaluation of frictional resistance with 5 ligation methods and Gianelly-type working wires.

INTRODUCTION: Numerous in-vitro studies have been conducted with various archwire-ligation combinations to evaluate the effect of wire size and ligation method on frictional resistance. The aim of this in-vitro study was to compare the frictional resistance during sliding mechanics with Gianelly-type stainless steel working wires, Leone slide ligature, conventional elastic ligature, and stainless steel (SS) ligature, and a conventional bracket and active and passive self-ligating brackets. METHODS: Three ligation methods with Victory (V) brackets--Leone (VLeone), conventional (regular) elastic (VReg), and SS (VSS)--were used with standard SS brackets, and 2 self-ligating brackets--Damon MX (Ormco/"A", St. Paul, Minn) (DMX) and In-Ovation R (GAC Intl., Bohemia, NY)--were used with 2 rectangular SS wires (0.016 x 0.022 and 0.018 x 0.022 in). Therefore, 5 ligation methods and 2 wire sizes were evaluated with respect to their effects on frictional resistance. RESULTS: No statistically significant differences were found between the SS ligation method and DMX (neither produced measurable static friction). For the wire size 0.016 x 0.022-in SS, the DMX and SS produced significantly less static friction than the In-Ovation R, VLeone, and VReg. The In-Ovation R produced significantly less friction than both the VLeone and VReg, whereas the VLeone produced significantly less friction than the VReg. For the wire size 0.018 x 0.022-in SS, the overall results were the same, except that the In-Ovation R produced significantly more friction than the VLeone. An increase in wire size (from 0.016 x 0.022 to 0.018 x 0.022 in) led to an increase in friction in all bracket-archwire combinations (except DMX and VSS, which showed no measurable friction at either wire size). CONCLUSIONS: The Leone slide ligature showed less friction at both wire sizes than VReg; however, it showed significantly more friction than both DMX and VSS. DMX and VSS brackets produced no measurable friction with either 0.016 x 0.022-in or 0.018 x 0.022-in wires. An increase in wire size (from 0.016 x 0.022 to 0.018 x 0.022 in) led to an increase in friction in all bracket-archwire combinations (excluding DMX and VSS, which showed no measurable friction at either wire size).

Assessing the need for anesthesia and sedation services in Kuwaiti dental practice.

The objective of this study was to examine the public health relevance of the prevalence of dental fear in Kuwait and the resultant barrier that it creates regarding access to dental care. The study analysis demonstrated a high prevalence of dental fear and anxiety in the Kuwaiti population and a perceived need for anesthesia services by dental care providers. The telephone survey of the general population showed nearly 35% of respondents reported being somewhat nervous, very nervous, or terrified about going to the dentist. In addition, about 36% of the population postponed their dental treatment because of fear. Respondents showed a preference to receive sedation and anesthesia services as a means of anxiety relief, and they were willing to go to the dentist more often when such services were available. People with high fear and anxiety preferred to receive some type of medication to relieve their anxiety. In conclusion, the significance and importance of the need for anesthesia services to enhance the public health of dental patients in Kuwait has been demonstrated, and improvements are needed in anesthesia and sedation training of Kuwaiti dental care providers.

Complications associated with anesthesia administered for dental treatment.

This assessment sought to identify and quantify complications that occur with anesthesia administration during dental treatment of consecutive patients who received care through the University of Pittsburgh School of Dental Medicine's (UPSDM) Department of Anesthesiology. This prospective study was completed by participating anesthesia caregivers at the UPSDM as a case-by-case evaluation. A standardized form delineating possible complications was used to collect data following 286 consecutive outpatient anesthetic cases administered within the UPSDM. After statistical analysis of five types of administered anesthesia, the overall complication rate was 22.4% in 286 cases. All of the complications were considered to be mild (90.6%) or moderate (9.4%); there were no reports of severe complications. The complications encountered most frequently were airway obstruction (18 reports) and occurrence of nausea/vomiting (12 reports). ASA classification, anesthetic technique, pre-existing medical findings, and the type of dental procedure performed all were variables that were found to affect the incidence of anesthesia-related complications. The overall complication rate from anesthesia administered during dental care is similar to or less than that reported within the hospital operating system environment.

Quantification of myosin heavy chain RNA in human laryngeal muscles: differential expression in the vertical and horizontal posterior cricoarytenoid and thyroarytenoid.

BACKGROUND: Human laryngeal muscles are composed of fibers that express type I, IIA, and IIX myosin heavy chains (MyHC), but the presence and quantity of atypical myosins such as perinatal, extraocular, IIB, and alpha (cardiac) remain in question. These characteristics have been determined by biochemical or immunohistologic tissue sampling but with no complementary evidence of gene expression at the molecular level. The distribution of myosin, the main motor protein, in relation to structure-function relationships in this specialized muscle group will be important for understanding laryngeal function in both health and disease. OBJECTIVES: We determined the quantity of MyHC genes expressed in human posterior cricoarytenoid (PCA) and thyroarytenoid (TA) muscle using real-time quantitative reverse-transcriptase polymerase chain reaction in a large number of samples taken from laryngectomy subjects. The PCA muscle was divided into vertical (V) and horizontal (H) portions for analysis. RESULTS AND CONCLUSIONS: No extraocular or IIB myosin gene message is present in PCA or TA, but IIB is expressed in human extraocular muscle. Low but detectable amounts of perinatal and alpha gene message are present in both of the intrinsic laryngeal muscles. In H- and V-PCA, MyHC gene amounts were beta greater than IIA greater than IIX, but amounts of fast myosin RNA were greater in V-PCA. In TA, the order was beta greater than IIX greater than IIA. The profiles of RNA determined here indicate that, in humans, neither PCA nor TA intrinsic laryngeal muscles express unique very fast-contracting MyHCs but instead may rely on differential synthesis and use of beta, IIA, and IIX isoforms to perform their specialized contractile functions.

Redefining the biologic width in severe, generalized, chronic periodontitis: implications for therapy.

BACKGROUND: Previous studies demonstrated significant variability in the histologic biologic width in periodontal health and mild periodontitis. The purpose of this study was to determine whether the previously established dimensions of the biologic width applied to subjects with severe, generalized, chronic periodontitis. METHODS: Twenty-eight subjects, aged 29 to 45 years, with severe, generalized, chronic periodontitis were included in the study. There were 18 males and 10 females, and 19 (68%) of the patients were smokers. Clinical and radiographic measures were taken by calibrated examiners. The clinical biologic width was determined from the most coronal level of clinical attachment to the crest of the alveolar bone for proximal surfaces only and compared to the histologic biologic width previously reported. RESULTS: The clinical biologic width in subjects with severe, generalized periodontitis was significantly greater than previously reported (P <0.001). For all evaluable proximal sites, the mean clinical biologic width was 3.95 mm versus the mean histologic biologic width of 2.04 mm. The greatest clinical biologic widths were seen with pockets <2 mm (5.02 +/- 2.48 mm; range: 1.60 to 9.00 mm) and 2 to 4 mm (4.16 +/- 1.32 mm; range: 0.20 to 6.40 mm). CONCLUSIONS: The mean clinical biologic width in subjects with severe, generalized, chronic periodontitis seemed to be significantly greater than the histologic biologic width previously reported for subjects not demonstrating significant periodontal pathology. In addition, sites with shallow probing depths demonstrated the greatest biologic width, suggesting that these sites may be at increased risk for losing clinically significant attachment during surgical procedures.

Exploring dental students' perceptions of cultural competence and social responsibility.

The improvement of basic cultural competency skills and the creation of a greater community-minded spirit among dental students are important parts of dental education. The purpose of our study was to assess changes in dental students' attitudes and beliefs about community service and changes in cultural competencies after participation in a two-year program of non-dental community service (Student Community Outreach Program and Education, SCOPE). During 2003-07, two identical twenty-eight-item surveys were administered to SCOPE participants/completers. In the first, students reported on their attitudes after program completion. In the second, students reported retrospectively on their attitudes prior to starting the program. One hundred twenty-six post- and pre-intervention surveys were matched and assessed for changes in student attitudes after program participation. Based on factor analysis, four distinct scales were identified: 1) community service, 2) cultural competence, 3) communication, and 4) treatment perspective. Over time, statistically significant changes (p<.05) in student attitudes and beliefs were found for scales 1 (p=.017), 2 (p=.001), and 3 (borderline significance, p=.057). Scale 4 showed no significant difference (p=.108). These scales indicate main focus areas to help guide future dentists in acquiring relevant sociocultural competencies and enabling community-minded attitudes. Overall, this study provides support for the addition of a non-dental community service-learning program into the preclinical curriculum.

Nanostructured calcium phosphates (NanoCaPs) for non-viral gene delivery: influence of the synthesis parameters on transfection efficiency.

Calcium phosphate (CaP) based approaches remain an attractive option for delivering plasmid DNA (pDNA) into cultured cells. However, despite their appeal, current synthesis methodologies typically yield lower, less consistent transfection efficiencies when compared to viral approaches. Therefore, we report here a novel method to consistently synthesize efficient, nano-sized, mono-dispersed CaP-pDNA particles; accomplished by optimizing both the stoichiometry (Ca/P ratio) of the CaP particles as well as the mode in which the calcium and phosphate precursor solutions are mixed. Our results indicate that calcium and phosphate precursors when mixed in a controlled and regulated manner reproducibly result in nano-sized particles that consistently yield higher transfection efficiencies when compared to particles synthesized via manual mixing (a two-fold increase was observed). Also, maximum transfection efficiencies in both HeLa and MC3T3-E1 cells lines were obtained when a Ca/P ratio between 100 and 300 was used. Particles synthesized within this optimum Ca/P ratio range were between 25 and 50 nm. Our data suggests that these maximized transfection efficiencies were obtained because these particles not only effectively condensed (70% efficient) but also efficiently bound (90% efficient) the pDNA. In addition, X-ray diffraction and Fourier transform infrared spectroscopy analyses confirmed that all of the synthesized CaP structures exhibited the hydroxyapatite phase.

Factors associated with parents' and adolescents' perceptions of oral health and need for dental treatment.

OBJECTIVE: The aim of this study was to characterize the association between clinical and psychosocial factors as they related to perceptions by parents and adolescents to the adolescent's oral health status and treatment need. Additionally, the degree to which adolescent's and parent's perceptions of oral health and treatment need were related was examined. METHODS: Data from the Pennsylvania oral health needs assessment for 530 parent-adolescent pairs were used to address the objectives of this study. Comparisons between clinical oral health measures, psychosocial factors, and the parent- and adolescent-reported perceptions of the adolescent's oral health status were made using descriptive and inferential statistics, including exploratory factor analysis and path analysis. RESULTS: Parents and adolescents exhibited only modest concordance on ratings of the adolescent's oral health status and need for dental treatment. Furthermore, parents tended to rate their adolescent's oral health status as better than did the adolescent. The results of the path analysis showed that adolescents based their ratings of oral health status more on oral symptoms, while parents rated their adolescent's oral health more on esthetic or psychosocial factors. CONCLUSIONS: Adolescents and parents based their perceptions of oral health status and treatment need on different underlying factors. Additionally, adolescents' perceptions of their oral health status and treatment needs did not appear to be communicated to their parents.

General dentists' evaluation of anesthesia sedation education in U.S. dental schools.

To assess the quality and quantity of sedation education in U.S. dental schools, a prospective, questionnaire-based survey was administered to general dental practitioners who graduated in 2003. Questionnaires were sent via facsimile to recent dental graduates using a list obtained through the American Dental Association. The response rate was 54 percent; 718 of the 1,328 nine-question surveys were returned. The response to the questionnaires indicates a perceived need for sedation care by the majority of recent graduates and low overall satisfaction with the quality of sedation education in U.S. dental schools. The general consensus of most 2003 dental school graduates is that they have gained little or no hands-on experience in sedation techniques and would have supported an increase in tuition and fees if an institution were to offer more efficient sedation training. With increased popularity and high patient demand for sedation techniques, the new dentist feels a need for sedation education before graduation.

Lobar and sublobar resection with and without brachytherapy for small stage IA non-small cell lung cancer.

OBJECTIVE: Computed tomographic screening is detecting ever smaller peripheral non-small cell lung cancers. These smaller cancers are amenable to sublobar resection, but sublobar resection is not currently the treatment of choice. This study compared sublobar resection with lobar resection for stage IA non-small cell lung cancers to assess whether sublobar resection is appropriate treatment for certain lesions. The use of adjuvant brachytherapy was also evaluated. METHODS: A retrospective multicenter study of 291 patients with T1 N0 disease was done. Outcomes after sublobar resection (n = 124) were compared with those after lobar resection (n = 167). Brachytherapy was used in conjunction with 60 (48%) sublobar resection operations. Analysis based on tumor diameter was performed. RESULTS: There were 137 cancers smaller than 2 cm and 154 cancers ranging from 2 to 3 cm. Patients undergoing sublobar resection were older (68.4 vs 66.1 years, P = .018) with poorer pulmonary function (forced expiratory volume in 1 second of 53.1% vs 78.2%, P = .001). Mean follow-up was 34.5 months. Brachytherapy decreased local recurrence rate significantly among patients undergoing sublobar resection, from 11 (17.2%) to 2 (3.3%). For tumors smaller than 2 cm, there was no difference in survival between sublobar resection and lobar resection groups. For the larger tumors (2-3 cm), median survival was significantly better in the lobar resection group, at 70 versus 44.7 months ( P = .003). CONCLUSION: Intraoperative brachytherapy may reduce the local recurrence that is usually reported with sublobar resection. Our experience supports the further investigation of the use of sublobar resection with brachytherapy for peripheral stage IA non-small cell lung cancers smaller than 2 cm.

Efficacy of laparoscopic fundoplication in controlling pulmonary symptoms associated with gastroesophageal reflux disease.

BACKGROUND: Gastroesophageal reflux disease (GERD)-induced pulmonary symptoms (PS) can be difficult to control. The effectiveness of laparoscopic fundoplication (LF) in controlling PS among patients with medically recalcitrant GERD is poorly documented. We evaluated our results in controlling important PS in patients with GERD undergoing LF. METHODS: Seventy-four patients (28 men, 46 women) were identified with clinically important PS from a prospective cohort of 155 patients undergoing elective LF for recalcitrant GERD. Median age was 52.5 years (range, 29-84 years). Sixty-seven (91%) patients were taking proton pump inhibitors at the time of operation. Quality of life by using the SF36 physical (PCS) and mental (MCS) component summary scores (normal, 50) and heartburn severity by using the health-related quality of life (HRQOL) (best score, 0; worst score, 45) were measured. RESULTS: All 74 patients with PS survived operation, and minor morbidity occurred in 5 (7%) patients. Median hospital stay was 2 days (range, 1-6 days), and return to normal activity was seen at 2.2 weeks (range, 1-8 weeks). Median follow-up was 12 months. PS were improved significantly (P < .01) for hoarseness (62% to 17.6%), bronchospasm (60% to 9.5%), and aspiration (22% to 1.4%). Before LF, 11 (14.9%) patients required bronchodilators or oral steroids. Postoperatively such therapy was required in only 3 (4.2%) patients (P = .019), with no patient requiring oral steroids. Patients with poorer control of their GERD on the basis of high HRQOL scores had significantly more PS after operation. CONCLUSIONS: A significant number of patients with medically recalcitrant GERD (46% from our prospective database) have important PS. LF can improve PS, decrease requirement for pulmonary medications, as well as improve typical reflux symptoms and quality of life.

Comparison of mutational changes in involved N1 lymph nodes with those in primary tumors in stage II non-small cell lung cancer: a pilot study.

OBJECTIVES: Surgical resection is the standard treatment for stage II non-small cell lung cancer, but recurrence rates approach 60%. This study compared mutational changes in involved lymph nodes and primary tumors from patients with stage II non-small cell lung cancer to determine whether risk factors for recurrence could be identified. METHODS: Forty patients with resected stage II non-small cell lung cancer (excluding T3 N0 disease) were studied. Microdissection was performed on primary tumors and lymph nodes. Analysis was performed across 9 genomic loci by using polymerase chain reaction amplification. The ratio of fractional allelic loss between involved lymph nodes and primary tumors was used to stratify patients into high-risk (fractional allelic loss ratio of >or=1) and low-risk (fractional allelic loss ratio of <1) groups. RESULTS: The median age of the patients was 68 years (range, 42-85 years). Median follow-up was 30 months. Fractional allelic loss was greater in patients with squamous carcinomas compared with that in adenocarcinomas, but survival was similar (35 vs 39 months). The median survival was 35 months in high-risk patients and was not reached in low-risk patients (P =.3). Disease-free survival was 24 months in high-risk patients and was not reached in low-risk patients (P =.35). In the subset with adenocarcinoma (n = 18), median survival was 24 months in the high-risk group; no deaths occurred in low-risk patients (P =.01). Also, disease-free survival was 14 months in high-risk patients and was not reached in the low-risk patients (P =.05). CONCLUSIONS: Squamous cancers demonstrate greater mutational changes than adenocarcinomas; this does not affect outcome. The patients with low-risk adenocarcinomas demonstrated superior outcomes compared with those of other patients. These results should be confirmed in larger studies.