No Wound Healing Complications or Recurrences Were Seen and a High Level of Satisfaction Was Reported in Patients Who Underwent Endoscopic Olecranon Bursectomy for Recalcitrant Olecranon Bursitis

Purpose

To determine the outcomes of endoscopic olecranon bursectomy for the treatment of recalcitrant olecranon bursitis in one surgeon's practice.

Methods

A retrospective analysis was conducted on all patients who underwent an endoscopic olecranon bursectomy for the treatment of recalcitrant olecranon bursitis between January 2018 and May 2021 at one surgeon's practice. Demographic variables as well as causes for olecranon bursitis such as aseptic, septic, and gouty tophi were recorded. In addition, any complications such as infection, recurrence, wound failure, or hospitalizations were documented, with wound dehiscence, recurrence of bursitis, and return to the operating room being the primary outcome measures. During the final phone encounter before finalizing this project, patients were queried to obtain the patient-reported form of the American Shoulder and Elbow Surgeons Elbow Questionnaire, quick Disabilities of the Arm Shoulder and Hand score, and the Single Assessment Numeric Evaluation score.

Results

Our study included 28 patients (23 male and 5 female) with an average age of 68 years (ranging from 33-86 years), all of whom had follow-up. The average follow-up was 24.7 months (range 3-42 months). There were 15 cases (54%) of aseptic bursitis, 13 cases (46%) of septic bursitis, and 7 cases (25%) that contained gouty tophi (5 aseptic and 2 septic). Of the 28 patients, 4 experienced complications. These all occurred within 3 months of surgery. One necessitated hospitalization and intravenous antibiotics, 2 were minor infections treated with oral antibiotics, and one was swelling treated successfully with in-office aspiration. Overall, 24 (86%) patients reported no issues at all related to the surgery. There were no instances of recurrence, wound failure, or secondary operations. Of the 20 (71.4%) patients who were reached for patient-reported form of the American Shoulder and Elbow Surgeons Elbow Questionnaire, quick Disabilities of the Arm Shoulder and Hand score, and Single Assessment Numeric Evaluation scores, all 20 patients reported no residual pain or difficulties with daily tasks. Average satisfaction with the procedure was 9.9 of 10 and, on average, patients reported that their elbow functionality was 96% with 100% representing completely normal.

Conclusions

In this population, patients who underwent endoscopic olecranon bursectomy experienced no recurrences or wound-healing complications necessitating return to the operating room. In addition, patients reported high function and satisfaction after the procedure.

Level of Evidence

Level IV, therapeutic case series.

Minimum 5-Year Outcomes After Primary Segmental Labral Reconstruction for Irreparable Labral Tears in the Hip With Hamstring Grafts: With a Subanalysis Comparing Autograft Versus Allograft

BACKGROUND

Comparable short-term outcomes have been obtained using hamstring allografts versus autografts after primary segmental labral reconstruction (SLR). Midterm results have not yet been determined.

PURPOSE

(1) To evaluate minimum 5-year patient-reported outcome (PRO) scores in patients who underwent primary SLR with hamstring grafts in the setting of femoroacetabular impingement syndrome (FAIS) and irreparable labral tears and (2) to compare the outcomes of hamstring autografts versus allografts in a subanalysis using propensity-matched groups.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Prospectively collected data were retrospectively reviewed for patients who underwent primary hip arthroscopy between September 2010 and November 2015. Patients were included if they underwent SLR using hamstring autografts or allografts and had preoperative and minimum 5-year PROs. The exclusion criteria were previous ipsilateral hip surgery or conditions, dysplasia, or Tönnis grade >1. Patients with autograft SLR were propensity matched 1 to 1 based on age, sex, and body mass index (BMI) to patients who underwent SLR using hamstring allografts. The minimal clinically important difference (MCID) and the Patient Acceptable Symptom State (PASS) were calculated.

RESULTS

Overall, 48 patients (N = hips 48) were eligible to be included in this study, and 41 patients (n = 41 hips [85.4%]) had a minimum 5-year follow-up reporting significant improvements in all PROs. Within the entire cohort, 9.8% required a secondary arthroscopy, with a mean time of 19 ± 1.8 months, and survivorship was 82.9%. Of the 41 included patients, 15 underwent an SLR with a hamstring autograft and were matched to 15 patients with labral reconstruction using a hamstring allograft. Groups were similar for sex (P > .999), age (P = .775), and BMI (P = .486). The mean follow-up times were 80.8 ± 25.5 and 66.1 ± 8.3 months (P = .223) for the autograft and allograft groups, respectively. Baseline PROs, preoperative radiographic measurements, surgical findings, and intraoperative procedures were similar. The groups achieved significant and comparable improvements for all PROs (P < .0001), satisfaction (P = .187), and the rate of achieving the MCID and the PASS. However, a tendency for higher postoperative PROs favoring allograft reconstruction was found.

CONCLUSION

At a minimum 5-year follow-up, patients who underwent primary arthroscopic SLR in the context of FAIS and irreparable labra, with either autograft or allograft hamstring tendons, reported significant improvements and comparable postoperative scores for all PROs, patient satisfaction, MCID, and PASS.

Magnon-phonon hybridization in 2D antiferromagnet MnPSe3

Magnetic excitations in van der Waals (vdW) materials, especially in the two-dimensional (2D) limit, are an exciting research topic from both the fundamental and applied perspectives. Using temperature-dependent, magneto-Raman spectroscopy, we identify the hybridization of two-magnon excitations with two phonons in manganese phosphorus triselenide (MnPSe₃), a magnetic vdW material that hosts in-plane antiferromagnetism. Results from first-principles calculations of the phonon and magnon spectra further support our identification. The Raman spectra’s rich temperature dependence through the magnetic transition displays an avoided crossing behavior in the phonons’ frequency and a concurrent decrease in their lifetimes. We construct a model based on the interaction between a discrete level and a continuum that reproduces these observations. Our results imply a strong hybridization between each phonon and a two-magnon continuum. This work demonstrates that the magnon-phonon interactions can be observed directly in Raman scattering and provides deep insight into these interactions in 2D magnetic materials.

Oversedation in Postoperative Patients Requiring Ventilator Support Greater than 48 Hours: A 4-year National Surgical Quality Improvement Program-driven Project

Prolonged mechanical ventilation of postoperative patients can contribute to an increase in morbidity. Every effort should be made to wean patients from the ventilator after surgery. Over-sedation may prevent successful extubation. Cases identified by the National Surgical Quality Improvement Program (NSQIP) for Huntington Hospital were reviewed. Oversedation, days on the ventilator, type and duration of sedation, and cost were studied. Data were collected from the NSQIP database and patient charts. Oversedation was determined by the Richmond Agitation Sedation Score (RASS) of each patient. The hospital pharmacy provided data on propofol. Forty-three (35%) patients were oversedated. Propofol was used in 111 (90%) cases with an average use of 4.8 days. Propofol was used greater than 48 hours in 77 (62%) cases. After identifying inconsistent nurse documentation of sedation, corrective actions helped decrease oversedation, average number of days on the ventilator, number of days on propofol, hospital expenditure on propofol, and number of patients on the ventilator greater than 48 hours. Oversedation contributed to prolonged mechanical ventilation. Standardization of RASS and physician sedation order sheets contributed to improving our NSQIP rating. Sedation use decreased and fewer patients spent less time on the ventilator. NSQIP is an effective tool to identify issues with quality in surgical patients.

Quasi-Two-Dimensional Magnon Identification in Antiferromagnetic FePS3via Magneto-Raman Spectroscopy

Recently it was discovered that van der Waals-bonded magnetic materials retain long range magnetic ordering down to a single layer, opening many avenues in fundamental physics and potential applications of these fascinating materials. One such material is FePS3, a large spin (S=2) Mott insulator where the Fe atoms form a honeycomb lattice. In the bulk, FePS3 has been shown to be a quasi-two-dimensional-Ising antiferromagnet, with additional features in the Raman spectra emerging below the Néel temperature (T N ) of approximately 120 K. Using magneto-Raman spectroscopy as an optical probe of magnetic structure, we show that one of these Raman-active modes in the magnetically ordered state is actually a magnon with a frequency of ≈3.7 THz (122 cm-1). Contrary to previous work, which interpreted this feature as a phonon, our Raman data shows the expected frequency shifting and splitting of the magnon as a function of temperature and magnetic field, respectively, where we determine the g-factor to be ≈2. In addition, the symmetry behavior of the magnon is studied by polarization-dependent Raman spectroscopy and explained using the magnetic point group of FePS3.

Phonon origin and lattice evolution in charge density wave states

Metallic transition metal dichalcogenides, such as tantalum diselenide (TaSe2), display quantum correlated phenomena of superconductivity and charge density waves (CDW) at low temperatures. Here, the photophysics of 2H-TaSe2 during CDW transitions is revealed by combining temperature-dependent, low-frequency Raman spectroscopy and density functional theory (DFT). The spectra contain amplitude, phase, and zone-folded modes that are assigned to specific phonons and lattice restructuring predicted by DFT calculations with superb agreement. The non-invasive and efficient optical methodology detailed here demonstrates an essential link between atomic-scale and microscopic quantum phenomena.

Resonance Raman signature of intertube excitons in compositionally-defined carbon nanotube bundles

Electronic interactions in low-dimensional nanomaterial heterostructures can lead to novel optical responses arising from exciton delocalization over the constituent materials. Similar phenomena have been suggested to arise between closely interacting semiconducting carbon nanotubes of identical structure. Such behavior in carbon nanotubes has potential to generate new exciton physics, impact exciton transport mechanisms in nanotube networks, and place nanotubes as one-dimensional models for such behaviors in systems of higher dimensionality. Here we use resonance Raman spectroscopy to probe intertube interactions in (6,5) chirality-enriched bundles. Raman excitation profiles for the radial breathing mode and G-mode display a previously unobserved sharp resonance feature. We show the feature is evidence for creation of intertube excitons and is identified as a Fano resonance arising from the interaction between intratube and intertube excitons. The universality of the model suggests that similar Raman excitation profile features may be observed for interlayer exciton resonances in 2D multilayered systems.

Bundles of single-wall carbon nanotubes with enriched chirality can be used as model systems for exploring exciton physics in low-dimensional nanostructures. Here, the authors use resonant Raman spectroscopy to probe intertube interactions in bundles of (6,5)-enriched carbon nanotubes, and observe a Fano resonance arising from coupling between intertube and intratube excitons.

Intricate Resonant Raman Response in Anisotropic ReS2

The strong in-plane anisotropy of rhenium disulfide (ReS₂) offers an additional physical parameter that can be tuned for advanced applications such as logic circuits, thin-film polarizers, and polarization-sensitive photodetectors. ReS₂ also presents advantages for optoelectronics, as it is both a direct-gap semiconductor for few-layer thicknesses (unlike MoS₂ or WS₂) and stable in air (unlike black phosphorus). Raman spectroscopy is one of the most powerful characterization techniques to nondestructively and sensitively probe the fundamental photophysics of a 2D material. Here, we perform a thorough study of the resonant Raman response of the 18 first-order phonons in ReS₂ at various layer thicknesses and crystal orientations. Remarkably, we discover that, as opposed to a general increase in intensity of all of the Raman modes at excitonic transitions, each of the 18 modes behave differently relative to each other as a function of laser excitation, layer thickness, and orientation in a manner that highlights the importance of electron-phonon coupling in ReS₂. In addition, we correct an unrecognized error in the calculation of the optical interference enhancement of the Raman signal of transition metal dichalcogenides on SiO₂/Si substrates that has propagated through various reports. For ReS₂, this correction is critical to properly assessing the resonant Raman behavior. We also implemented a perturbation approach to calculate frequency-dependent Raman intensities based on first-principles and demonstrate that, despite the neglect of excitonic effects, useful trends in the Raman intensities of monolayer and bulk ReS₂ at different laser energies can be accurately captured. Finally, the phonon dispersion calculated from first-principles is used to address the possible origins of unexplained peaks observed in the Raman spectra, such as infrared-active modes, defects, and second-order processes.

Enhancing single-wall carbon nanotube properties through controlled endohedral filling

Chemical control of the endohedral volume of single-wall carbon nanotubes (SWCNTs) via liquid-phase filling is established to be a facile strategy to controllably modify properties of SWCNTs in manners significant for processing and proposed applications. Encapsulation of over 20 different compounds with distinct chemical structures, functionalities, and effects is demonstrated in SWCNTs of multiple diameter ranges, with the ability to fill the endohedral volume based on the availability of the core volume and compatibility of the molecule's size with the cross-section of the nanotube's cavity. Through exclusion of ingested water and selection of the endohedral chemical environment, significant improvements to the optical properties of dispersed SWCNTs such as narrowed optical transition linewidths and enhanced fluorescence intensities are observed. Examples of tailoring modified properties towards applications or improved processing by endohedral passivation are discussed.

Intensity Ratio of Resonant Raman Modes for (n,m) Enriched Semiconducting Carbon Nanotubes

Relative intensities of resonant Raman spectral features, specifically the radial breathing mode (RBM) and G modes, of 11, chirality-enriched, single-wall carbon nanotube (SWCNT) species were established under second-order optical transition excitation. The results demonstrate an under-recognized complexity in the evaluation of Raman spectra for the assignment of (n,m) population distributions. Strong chiral angle and mod dependencies affect the intensity ratio of the RBM to G modes and can result in misleading interpretations. Furthermore, we report five additional (n,m) values for the chirality-dependent G(+) and G(-) Raman peak positions and intensity ratios; thereby extending the available data to cover more of the smaller diameter regime by including the (5,4) second-order, resonance Raman spectra. Together, the Raman spectral library is demonstrated to be sufficient for decoupling G peaks from multiple species via a spectral fitting process, and enables fundamental characterization even in mixed chiral population samples.

Isolation of >1 nm Diameter Single-Wall Carbon Nanotube Species Using Aqueous Two-Phase Extraction

In this contribution we demonstrate the effective separation of single-wall carbon nanotube (SWCNT) species with diameters larger than 1 nm through multistage aqueous two-phase extraction (ATPE), including isolation at the near-monochiral species level up to at least the diameter range of SWCNTs synthesized by electric arc synthesis (1.3-1.6 nm). We also demonstrate that refined species are readily obtained from both the metallic and semiconducting subpopulations of SWCNTs and that this methodology is effective for multiple SWCNT raw materials. Using these data, we report an empirical function for the necessary surfactant concentrations in the ATPE method for separating different SWCNTs into either the lower or upper phase as a function of SWCNT diameter. This empirical correlation enables predictive separation design and identifies a subset of SWCNTs that behave unusually as compared to other species. These results not only dramatically increase the range of SWCNT diameters to which species selective separation can be achieved but also demonstrate that aqueous two-phase separations can be designed across experimentally accessible ranges of surfactant concentrations to controllably separate SWCNT populations of very small (∼0.62 nm) to very large diameters (>1.7 nm). Together, the results reported here indicate that total separation of all SWCNT species is likely feasible by the ATPE method, especially given future development of multistage automated extraction techniques.

Isolation of specific small-diameter single-wall carbon nanotube species via aqueous two-phase extraction

Aqueous two-phase extraction is demonstrated to enable isolation of single semiconducting and metallic single-wall carbon nanotube species from a synthetic mixture. The separation is rapid and robust, with remarkable tunability via modification of the surfactant environment set for the separation.

Thermal conductivity of monolayer molybdenum disulfide obtained from temperature-dependent Raman spectroscopy

Atomically thin molybdenum disulfide (MoS2) offers potential for advanced devices and an alternative to graphene due to its unique electronic and optical properties. The temperature-dependent Raman spectra of exfoliated, monolayer MoS2 in the range of 100-320 K are reported and analyzed. The linear temperature coefficients of the in-plane E2g 1 and the out-of-plane A1g modes for both suspended and substrate-supported monolayer MoS2 are measured. These data, when combined with the first-order coefficients from laser power-dependent studies, enable the thermal conductivity to be extracted. The resulting thermal conductivity κ = (34.5(4) W/mK at room temperature agrees well with the first principles lattice dynamics simulations. However, this value is significantly lower than that of graphene. The results from this work provide important input for the design of MoS2-based devices where thermal management is critical.

Oversedation in postoperative patients requiring ventilator support greater than 48 hours: a 4-year National Surgical Quality Improvement Program-driven project

Prolonged mechanical ventilation of postoperative patients can contribute to an increase in morbidity. Every effort should be made to wean patients from the ventilator after surgery. Oversedation may prevent successful extubation. Cases identified by the National Surgical Quality Improvement Program (NSQIP) for Huntington Hospital were reviewed. Oversedation, days on the ventilator, type and duration of sedation, and cost were studied. Data were collected from the NSQIP database and patient charts. Oversedation was determined by the Richmond Agitation Sedation Score (RASS) of each patient. The hospital pharmacy provided data on propofol. Forty-three (35%) patients were oversedated. Propofol was used in 111 (90%) cases with an average use of 4.8 days. Propofol was used greater than 48 hours in 77 (62%) cases. After identifying inconsistent nurse documentation of sedation, corrective actions helped decrease oversedation, average number of days on the ventilator, number of days on propofol, hospital expenditure on propofol, and number of patients on the ventilator greater than 48 hours. Oversedation contributed to prolonged mechanical ventilation. Standardization of RASS and physician sedation order sheets contributed to improving our NSQIP rating. Sedation use decreased and fewer patients spent less time on the ventilator. NSQIP is an effective tool to identify issues with quality in surgical patients.

Analyzing surfactant structures on length and chirality resolved (6,5) single-wall carbon nanotubes by analytical ultracentrifugation

The structure and density of the bound interfacial surfactant layer and associated hydration shell were investigated using analytical ultracentrifugation for length and chirality purified (6,5) single-wall carbon nanotubes (SWCNTs) in three different bile salt surfactant solutions. The differences in the chemical structures of the surfactants significantly affect the size and density of the bound surfactant layers. As probed by exchange of a common parent nanotube population into sodium deoxycholate, sodium cholate, or sodium taurodeoxycholate solutions, the anhydrous density of the nanotubes was least for the sodium taurodeoxycholate surfactant, and the absolute sedimentation velocities greatest for the sodium cholate and sodium taurodeoxycholate surfactants. These results suggest that the thickest interfacial layer is formed by the deoxycholate, and that the taurodeoxycholate packs more densely than either sodium cholate or deoxycholate. These structural differences correlate well to an observed 25% increase in fluorescence intensity relative to the cholate surfactant for deoxycholate and taurodeoxycholate dispersed SWCNTs displaying equivalent absorbance spectra. Separate sedimentation velocity experiments including the density modifying agent iodixanol were used to establish the buoyant density of the (6,5) SWCNT in each of the bile salt surfactants; from the difference in the buoyant and anhydrous densities, the largest hydrated diameter is observed for sodium deoxycholate. Understanding the effects of dispersant choice and the methodology for measurement of the interfacial density and hydrated diameter is critical for rationally advancing separation strategies and applications of nanotubes.

The tree BVOC index

Urban trees can produce a number of benefits, among them improved air quality. Biogenic volatile organic compounds (BVOCs) emitted by some species are ozone precursors. Modifying future tree planting to favor lower-emitting species can reduce these emissions and aid air management districts in meeting federally mandated emissions reductions for these compounds. Changes in BVOC emissions are calculated as the result of transitioning to a lower-emitting species mix in future planting. A simplified method for calculating the emissions reduction and a Tree BVOC index based on the calculated reduction is described. An example illustrates the use of the index as a tool for implementation and monitoring of a tree program designed to reduce BVOC emissions as a control measure being developed as part of the State Implementation Plan (SIP) for the Sacramento Federal Nonattainment Area.

Separation of empty and water-filled single-wall carbon nanotubes

The separation of empty and water-filled laser ablation and electric arc synthesized nanotubes is reported. Centrifugation of these large-diameter nanotubes dispersed with sodium deoxycholate using specific conditions produces isolated bands of empty and water-filled nanotubes without significant diameter selection. This separation is shown to be consistent across multiple nanotube populations dispersed from different source soots. Detailed spectroscopic characterization of the resulting empty and filled fractions reveals that water filling leads to systematic changes to the optical and vibrational properties. Furthermore, sequential separation of the resolved fractions using cosurfactants and density gradient ultracentrifugation reveals that water filling strongly influences the optimal conditions for metallic and semiconducting separation.

Carbon nanotubes: measuring dispersion and length

Advanced technological uses of single-walled carbon nanotubes (SWCNTs) rely on the production of single length and chirality populations that are currently only available through liquid-phase post processing. The foundation of all of these processing steps is the attainment of individualized nanotube dispersions in solution. An understanding of the colloidal properties of the dispersed SWCNTs can then be used to design appropriate conditions for separations. In many instances nanotube size, particularly length, is especially active in determining the properties achievable in a given population, and, thus, there is a critical need for measurement technologies for both length distribution and effective separation techniques. In this Progress Report, the current state of the art for measuring dispersion and length populations, including separations, is documented, and examples are used to demonstrate the desirability of addressing these parameters.

Multimodal, nanoscale, hyperspectral imaging demonstrated on heterostructures of quantum dots and DNA-wrapped single-wall carbon nanotubes

A multimodality imaging technique integrating atomic force, polarized Raman, and fluorescence lifetime microscopies, together with 2D autocorrelation image analysis is applied to the study of a mesoscopic heterostructure of nanoscale materials. This approach enables simultaneous measurement of fluorescence emission and Raman shifts from a quantum dot (QD)-single-wall carbon nanotube (SWCNT) complex. Nanoscale physical and optoelectronic characteristics are observed including local QD concentrations, orientation-dependent polarization anisotropy of the SWCNT Raman intensities, and charge transfer from photoexcited QDs to covalently conjugated SWCNTs. Our measurement approach bridges the properties observed in bulk and single nanotube studies. This methodology provides fundamental understanding of the charge and energy transfer between nanoscale materials in an assembly.

Centrifugal length separation of carbon nanotubes

Separation of single-wall carbon nanotubes (SWCNTs) by length via centrifugation in a high density medium, and the characterization of both the separated fractions and the centrifugation process are presented. Significant quantities of the separated SWCNTs ranging in average length from <50 nm to approximately 2 microm were produced, with the distribution width being coupled to the rate of the separation. Less rapid separation is shown to produce narrower distributions; these length fractions, produced using sodium deoxycholate dispersed SWCNTs, were characterized by UV-visible-near-infrared absorption and fluorescence spectroscopy, dynamic light scattering, Raman scattering, and atomic force microscopy. Several parameters of the separation were additionally explored: SWCNT concentration, added salt concentration, liquid density, rotor speed, surfactant concentration, and the processing temperature. The centrifugation technique is shown to support 10 mg per day scale processing and is applicable to all of the major SWCNT production methods. The cost per unit of the centrifugation-based separation is also demonstrated to be significantly less than size exclusion chromatography-based separations.

Length-Dependent Optical Effects in Single-Wall Carbon Nanotubes

Among the novel chemical and physical attributes of single-wall carbon nanotubes (SWCNTs), the optical properties are perhaps the most compelling. Although much is known about how such characteristics depend on nanotube chirality and diameter, relatively little is known about how the optical response depends on length, the next most obvious and fundamental nanotube trait. We show here that the intrinsic optical response of single-wall carbon nanotubes exhibits a strong dependence on nanotube length, and we offer a simple explanation that relates this behavior to the localization of a bound exciton along the length of a nanotube. The results presented here suggest that, for a given volume fraction, the longest nanotubes display significantly enhanced absorption, near-infrared fluorescence, and Raman scattering, which has important practical implications for potential applications that seek to exploit the unique optical characteristics of SWCNTs.

Dielectric response of aligned semiconducting single-wall nanotubes

We report measurements of the full intrinsic optical anisotropy of isolated single-wall carbon nanotubes (SWNTs). By combining absorption spectroscopy with transmission ellipsometry and polarization-dependent resonant Raman scattering, we obtain the real and imaginary parts of the SWNT permittivity from aligned semiconducting SWNTs dispersed in stretched polymer films. Our results are in agreement with theoretical predictions, highlighting the limited polarizability of excitons in a quasi-1D system.

Comparative Measures of Single-Wall Carbon Nanotube Dispersion

Model composites of DNA-wrapped single-wall carbon nanotubes in poly(acrylic acid) are used to evaluate metrics of nanotube dispersion. By varying the pH of the precursor solutions, we introduce a controlled deviation from ideal behavior. On the basis of small-angle neutron scattering, changes in near-infrared fluorescence intensity are strongly correlated with dispersion, while optical absorption spectroscopy and resonant Raman scattering are less definitive. Our results represent the first systematic comparison of currently accepted measures of nanotube dispersion.

High temperature ferromagnetism with a giant magnetic moment in transparent co-doped SnO(2-delta)

The occurrence of room temperature ferromagnetism is demonstrated in pulsed laser deposited thin films of Sn(1-x)Co(x)O(2-delta) (x<0.3). Interestingly, films of Sn(0.95)Co(0.05)O(2-delta) grown on R-plane sapphire not only exhibit ferromagnetism with a Curie temperature close to 650 K, but also a giant magnetic moment of 7.5+/-0.5 micro(B)/Co, not yet reported in any diluted magnetic semiconductor system. The films are semiconducting and optically highly transparent.

Exchange interaction effects on the optical properties of LuMnO3

We have measured the optical conductivity of single crystal LuMnO3 from 10 to 45000 cm(-1) at temperatures between 4 and 300 K. A symmetry allowed on-site Mn d-d transition near 1.7 eV is observed to blueshift ( approximately 0.1 eV) in the antiferromagnetic state due to Mn-Mn superexchange interactions. Similar anomalies are observed in the temperature dependence of the TO phonon frequencies which arise from spin-phonon interaction. We find that the known anomaly in the temperature dependence of the quasistatic dielectric constant epsilon(0) below T(N) approximately 90 K is overwhelmingly dominated by the phonon contributions.

Intensity-modulated radiation therapy reduces late salivary toxicity without compromising tumor control in patients with oropharyngeal carcinoma: a comparison with conventional techniques

BACKGROUND AND PURPOSE

Intensity-modulated radiation therapy (IMRT) offers superior dosimetric conformity for normal tissue sparing in patients with oropharyngeal cancer. In this study, acute and late toxicity, and tumor control were compared between conventional beam arrangement (CRT) and IMRT.

MATERIALS AND METHODS

Between January 1970 and December 1999, 430 patients with carcinoma of the oropharynx were treated at the Mallinckrodt Institute of Radiology. There were 260 patients with tonsil primary tumors and 170 patients with tumors arising from the base of the tongue. Twenty-four (6%) patients had stage I disease, 88 (20%) had stage II, 128 (30%) had stage III, and 190 (44%) had stage IV disease. Patients were divided into five treatment groups. Group I consisted of 109 patients who received preoperative CRT. Group II consisted of 142 patients who received postoperative CRT. Group III consisted of 153 patients who received definitive CRT. Inverse planning IMRT (Peacock, NOMOS) was used to treat 14 patients postoperatively (Group IV) and 12 patients definitively without surgery (Group V). Acute and late normal tissue side-effects were scored according to the Radiation Therapy Oncology Group radiation morbidity criteria. The median follow-up was 3.9 years.

RESULTS

The 2-year local-regional control values for the five studied groups were 78, 76, 68, 100 and 88%, respectively. The 2-year disease-free survival values for the five studied groups were 68, 74, 58, 92 and 80%, respectively. IMRT significantly reduced the incidence of late xerostomia.

CONCLUSIONS

When IMRT was compared with conventional techniques, the dosimetric advantage of IMRT did translate into a significant reduction of late salivary toxicity in patients with oropharyngeal carcinoma. No adverse impact on tumor control and disease-free survival was observed in patients treated with IMRT.

The emotional modulation of cognitive processing: an fMRI study

The functional neuroanatomy of visual processing of surface features of emotionally valenced pictorial stimuli was examined in normal human subjects using functional magnetic resonance imaging (fMRI). Pictorial stimuli were of two types: emotionally negative and neutral pictures. Task performance was slower for the negatively valenced than for the neutral pictures. Significant blood oxygen level dependent (BOLD) increases occurred in the medial and dorsolateral prefrontal cortex, midbrain, substantia innominata, and/or amygdala, and in the posterior cortical visual areas for both stimulus types. Increases were greater for the negatively valenced stimuli. While there was a small but significant BOLD decrease in the subgenual prefrontal cortex, which was larger in response to the negatively valenced pictures, there was an almost complete absence of other decreases prominently seen during the performance of demanding cognitive tasks [Shulman, G. L., Fiez, J. A., Corbetta, M., Buckner, R. L., Miezin, F. M., Raichle, M. E., & Petersen, S. E. (1997). Common blood flow changes across visual tasks: II. Decreases in cerebral cortex. Journal of Cognitive Neuroscience, 9, 648--663]. These results provide evidence that the emotional valence and arousing nature of stimuli used during the performance of an attention-demanding cognitive task are reflected in discernable, quantitative changes in the functional anatomy associated with task performance.

Esthesioneuroblastoma: the impact of treatment modality

BACKGROUND

We evaluated the impact of treatment modality on esthesioneuroblastoma.

METHODS

Between 1976 and 1996, 25 patients with esthesioneuroblastoma were treated at Mallinckrodt Institute of Radiology. There were 11 male and 14 female patients; their ages ranged from 16 to 73 years (median, 57 years). The tumors were Kadish stage A in 3, Stage B in 13, C in 8, and modified D in 1 (cervical nodal metastasis). Seventeen patients were treated with surgery and radiation therapy, six were treated with irradiation alone, and two were treated with surgery only. Eight patients received neoadjuvant chemotherapy. Median follow-up was 8 years (range, 2-24 years).

RESULTS

The 5-year actuarial overall survival, disease-free survival, and local tumor control rates were 66.3%, 56.3%, and 73.0%, respectively. Kadish stage was not a significant prognosticator for local control or disease-free survival. Five-year local control rates were 87.4% for the combination of surgery and radiation therapy and 51.2% for irradiation alone. Two patients with Kadish stage A and B disease underwent surgical resection alone; both failed locally. In contrast, 33.3% of patients (three of nine) with Kadish stage A or B disease who received adjuvant radiation therapy had a local recurrence develop. With adjuvant radiation therapy, the surgical margin status did not influence local tumor control. Among the eight patients who received neoadjuvant chemotherapy, six patients showed no response, one had partial response, and one showed a complete response.

CONCLUSIONS

Surgical resection plus adjuvant radiation therapy yielded the best treatment outcome. More effective chemotherapy agents with a reproducible effectiveness are needed for patients with locally advanced esthesioneuroblastoma.

Cancer of retromolar trigone: long-term radiation therapy outcome

BACKGROUND

Cancer of the retromolar trigone is an uncommon head and neck cancer. In this retrospective study, we identified the prognostic factors and evaluated the therapeutic outcomes of patients treated with preoperative radiation therapy (RT), postoperative RT, and RT alone.

METHODS

Between 1971 and 1994, 65 patients with histologically proven epidermoid carcinoma of the retromolar trigone were treated at the Mallinckrodt Institute of Radiology; 10 patients received preoperative RT (30-55.2 Gy), 39 received postoperative RT (46-66.6 Gy), and 15 were treated with RT alone (63-74 Gy). Surgery included 44 composite resections and 7 wide excisions. The minimum follow-up was 5 years.

RESULTS

The 5-year disease-free survival rates were 90% with preoperative RT, 63% with postoperative RT, and 31% with RT alone. The 5-year disease-free survival rates were 76% for patients with T1 disease, 50% for T2, 72% for T3, and 54% for T4. The 5-year disease-free survival rates were 69% for patients with NO disease, 56% for N1, and 26% for N2. The locoregional recurrence rates were 10% (1 of 10) for preoperative RT, 23% (9 of 39) for postoperative RT, and 44% (7 of 16) for RT alone. On multivariate analysis, the significant factors for disease-free survival were treatment modality (p =.002) and N stage (p =.012); for locoregional control it was treatment modality (p =.046); and for distant metastasis it was N stage (p =.002). The incidence of bone necrosis, soft tissue necrosis, and severe trismus was 12% with postoperative RT, 11% with RT alone, and none with preoperative RT.

CONCLUSIONS

Combination surgery with postoperative or preoperative RT offers better locoregional control and disease-free survival than RT alone for epidermoid carcinoma of the retromolar trigone. Lymph node status significantly influences the disease-free survival and distant metastasis rates.

Emotion-induced changes in human medial prefrontal cortex: II. During anticipatory anxiety

Regional cerebral blood flow (BF) was examined in the human medial prefrontal cortex (MPFC) with positron emission tomography during anticipatory anxiety. Transient anxiety was induced in normal subjects by having them anticipate a painful shock to the fingers of one hand. BF was decreased during anticipatory anxiety, relative to an eyes-closed resting condition, in two regions of the MPFC (Brodmann Areas 10/32 and 24/25). BF decreases in these areas were inversely correlated with anxiety self rating, such that the least anxious subjects exhibited the largest BF reductions, whereas the most anxious subjects showed no significant BF reduction or a slight increase. BF changes in MPFC and in the midbrain were correlated with each other and with anxiety self rating. These results are consistent with the hypothesis that BF reductions in MPFC, previously observed in cognitive tasks, reflect a dynamic balance between focused attention and subject anxiety and may occur from a functionally active baseline or default state. The characterization of such relationships within the human brain enables new insights into the integration of cognition and emotion.

Emotion-induced changes in human medial prefrontal cortex: I. During cognitive task performance

Regional cerebral blood flow (BF) was examined in regions of the medial prefrontal cortex (MPFC) with positron-emission tomography while subjects performed two cognitive tasks, reading nouns aloud and generating appropriate verbs for the same nouns. The control task was passive viewing of the same words. BF was reduced in regions of the MPFC during word reading and naive verb generation, relative to a control state in which the subjects passively viewed nouns. Practicing verb generation produced improved performance, as measured by response time, which was strongly correlated with further reductions in MPFC and hypothalamic BF. After practice, when verb generation was performed on a novel list of words, reaction times slowed and the pattern of MPFC BF reverted to that seen in the word reading and naive conditions. A separate behavioral study of the verb-generation task indicated that anxiety, high during naive use-generation as measured by heart rate and self-report, decreased with practice on the task but returned with the introduction of a novel list of words. Taken together, these results suggest that the MPFC is part of a network, including the hypothalamus and brainstem, whose activity reflects a dynamic interplay between cognitive task performance and emotion.

Stage I (T1 N0 M0) squamous cell carcinoma of the laryngeal glottis: therapeutic results and voice preservation

BACKGROUND

The therapeutic outcomes for voice preservation in Stage I (T1 N0 M0) glottic carcinoma, treated with conservation surgery, radiation therapy, and endoscopic resection, are controversial.

METHODS

A retrospective tumor registry retrieval of data on patients treated with curative intent at Washington University Medical Center-Barnes Hospital between January 1971 and December 1990 for the surgical group, January 1971 to December 1985 for the low-dose radiation group, and January 1986 to January 1995 for the high-dose radiation group, was performed.

RESULTS

The 659 patients with Stage I (T1 N0 M0) glottic carcinoma treated with curative intent were subdivided into four groups: (1) 90 patients received low-dose radiation (mean dose 58 Gy, range 55-65 Gy, daily fractionation 1.5-1.8 Gy); (2) 104 patients received high-dose radiation (mean dose 66.5 Gy, range 65-70 Gy, daily fractionation 2-2.25 Gy); (3) 404 patients underwent conservation surgery; and (4) 61 patients had endoscopic resection. T1A (85%) and T1B (15%) disease was equally distributed among the groups. The anterior commissure was involved in 38 patients in the radiation therapy groups and 56 patients in the surgical groups. The overall local control was 89%. The overall local salvage was 84%. The overall unaided laryngeal voice preservation was 90%. The overall 5-year disease specific and actuarial survival rates were 95% and 81%, respectively. Prevalence of 2% regional metastases, 1.2% distant metastases, and 14% second primary malignancies were documented. The cure rate was 69% for regional metastases, 13% for distant metastases, and 44% for second primary malignancies. There were 5 complication deaths (0.1%), and 38 (6%) patients died of intercurrent disease. The use and dose of tobacco products was significantly increased in patients who died of intercurrent disease (p = 0.004) or developed second primary malignancies (p = 0.024). No significant difference was observed among the four therapeutic groups in the 5-year cause-specific survival rate (p, 0.68). Actuarial survival was significantly decreased in the low-dose radiation therapy group as compared with the other three therapeutic groups (p = 0.04). Initial local control was poorer for the endoscopic (77%) and low-dose radiation (78%) groups as compared with the high-dose radiation (89%) and conservation surgery (92%) groups (p = 0.02) but significant differences were not found for ultimate local control following salvage treatment. Unaided laryngeal voice preservation was similar for high-dose radiation (89%), conservation surgery (93%) and endoscopic resection (90%), but significantly poorer for low-dose radiation (80%; p = 0.02). T1B disease (N = 94) had similar local control and voice preservation with conservation surgery (87%) and high-dose radiation (88%) but lower results with low-dose radiation and endoscopic resections (67% unaided laryngeal voice preservation; p = 0.02).

CONCLUSION

(1)The four therapeutic groups achieved similar rates of disease specific survival and ultimate local control. (2) Low-dose radiation was associated with significantly lower overall actuarial survival and unaided laryngeal voice preservation. (3) Endoscopic resection was associated with a significantly lower initial local control rate, but following salvage therapy achieved equivalent results to the other treatment methods. (4) Patients with (T1 N0 M0) glottic carcinoma had similar survival, local control, and unaided laryngeal voice preservation rates with high-dose radiation, conservation surgery, and endoscopic resections, but not with low-dose radiation therapy. (c) 1999 John Wiley & Sons, Inc. Head Neck 21: 707-717, 1999.

Stage I (T1 N0 M0) squamous cell carcinoma of the laryngeal glottis: therapeutic results and voice preservation

BACKGROUND

The therapeutic outcomes for voice preservation in Stage I (T1 N0 M0) glottic carcinoma, treated with conservation surgery, radiation therapy, and endoscopic resection, are controversial.

METHODS

A retrospective tumor registry retrieval of data on patients treated with curative intent at Washington University Medical Center-Barnes Hospital between January 1971 and December 1990 for the surgical group, January 1971 to December 1985 for the low-dose radiation group, and January 1986 to January 1995 for the high-dose radiation group, was performed.

RESULTS

The 659 patients with Stage I (T1 N0 M0) glottic carcinoma treated with curative intent were subdivided into four groups: (1) 90 patients received low-dose radiation (mean dose 58 Gy, range 55-65 Gy, daily fractionation 1.5-1.8 Gy); (2) 104 patients received high-dose radiation (mean dose 66.5 Gy, range 65-70 Gy, daily fractionation 2-2.25 Gy); (3) 404 patients underwent conservation surgery; and (4) 61 patients had endoscopic resection. T1A (85%) and T1B (15%) disease was equally distributed among the groups. The anterior commissure was involved in 38 patients in the radiation therapy groups and 56 patients in the surgical groups. The overall local control was 89%. The overall local salvage was 84%. The overall unaided laryngeal voice preservation was 90%. The overall 5-year disease specific and actuarial survival rates were 95% and 81%, respectively. Prevalence of 2% regional metastases, 1.2% distant metastases, and 14% second primary malignancies were documented. The cure rate was 69% for regional metastases, 13% for distant metastases, and 44% for second primary malignancies. There were 5 complication deaths (0.1%), and 38 (6%) patients died of intercurrent disease. The use and dose of tobacco products was significantly increased in patients who died of intercurrent disease (p = 0.004) or developed second primary malignancies (p = 0.024). No significant difference was observed among the four therapeutic groups in the 5-year cause-specific survival rate (p, 0.68). Actuarial survival was significantly decreased in the low-dose radiation therapy group as compared with the other three therapeutic groups (p = 0.04). Initial local control was poorer for the endoscopic (77%) and low-dose radiation (78%) groups as compared with the high-dose radiation (89%) and conservation surgery (92%) groups (p = 0.02) but significant differences were not found for ultimate local control following salvage treatment. Unaided laryngeal voice preservation was similar for high-dose radiation (89%), conservation surgery (93%) and endoscopic resection (90%), but significantly poorer for low-dose radiation (80%; p = 0.02). T1B disease (N = 94) had similar local control and voice preservation with conservation surgery (87%) and high-dose radiation (88%) but lower results with low-dose radiation and endoscopic resections (67% unaided laryngeal voice preservation; p = 0.02).

CONCLUSION

(1)The four therapeutic groups achieved similar rates of disease specific survival and ultimate local control. (2) Low-dose radiation was associated with significantly lower overall actuarial survival and unaided laryngeal voice preservation. (3) Endoscopic resection was associated with a significantly lower initial local control rate, but following salvage therapy achieved equivalent results to the other treatment methods. (4) Patients with (T1 N0 M0) glottic carcinoma had similar survival, local control, and unaided laryngeal voice preservation rates with high-dose radiation, conservation surgery, and endoscopic resections, but not with low-dose radiation therapy. (c) 1999 John Wiley & Sons, Inc. Head Neck 21: 707-717, 1999.

Management of stage II (T2N0M0) glottic carcinoma by radiotherapy and conservation surgery

BACKGROUND

The best therapeutic approach for the treatment of stage II (T2N0M0) glottic carcinoma is controversial.

METHODS

A retrospective tumor registry data retrieval of patients with stage II glottic carcinoma treated with curative intent at Washington University Medical Center-Barnes Hospital between January 1971 and December 1989 (surgery) and December 1995 (radiotherapy) was performed.

RESULTS

Among 134 patients with stage II glottic carcinomas treated with curative intent and function preservation, there were 47 patients treated with low dose radiotherapy (median dose, 58.5 Gy at 1.5-1.8 Gy daily fractions), 16 patients with high dose radiotherapy (67.5-70 Gy) at higher daily fractionation doses (2-2.25 Gy), and 71 patients underwent conservation surgery. The overall local control rate was 85%. The overall salvage rate was 68%. The 5-year actuarial and disease specific survivals were 81.5% and 92%, respectively. Unaided phonation was achieved in 84.4% of the patients. An incidence of 10.4% regional metastases, 2.2% distant metastases, and 6% second primary tumors was documented. There were no statistical differences in local control, voice preservation, and 5-year actuarial and disease specific cure rates between conservation surgery and high dose radiation (p = .89). Low dose radiation had statistically lower local controls, 5-year survival, and voice preservation (p = .014). In advanced T2B disease, treating the ipsilateral neck nodes reduced regional metastases (p = .02).

CONCLUSIONS

High dose and daily fractionation (70 Gy at 2 Gy daily fraction doses) radiation achieved results equivalent to those of conservation surgery in 5-year local control, survival, and voice preservation. In advanced T2B disease, treatment of the ipsilateral neck nodes by radiotherapy or functional neck dissection reduced regional metastases.

Symptoms as an index of biologic behavior in head and neck cancer

The TNM staging system for head and neck cancer is based on the morphologic description of the tumor and disregards the clinical condition of the patient. Cancer symptoms were evaluated as a biologic index of disease to improve survival estimates. The medical records of 1010 patients receiving initial cancer treatment between 1980 and 1991 were retrospectively reviewed. The mean survival duration was 62 months for the entire population. By use of SAS statistical software (SAS Institute, Cary, NC), 48 symptom variables were screened by univariate analysis, and 23 of these variables were selected for entry into a Cox proportional hazards model on the basis of survival duration. Dysphagia, otalgia, neck lump, and weight loss were identified as independent predictors of survival duration (P < 0.01). A composite symptom-severity staging system was created on the basis of the 4 symptoms. Mean survival duration (95% CI) by symptom-severity stage was as follows: none, 74 months (70 to 79 months); mild, 56 months (51 to 61 months); moderate, 40 months (33 to 47 months); and severe, 31 months (22 to 41 months) (chi 2 = 30.8, P = 0.0001). Survival duration by TNM stage was as follows: I, 89 months (82 to 95 months); II, 71 months (65 to 78 months); III, 53 months (47 to 59 months); and IV, 42 months (37 to 47 months) (chi 2 = 56.2, P = 0.0001). When symptom-severity stage was entered in a proportional-hazards model along with TNM stage, comorbidity, age, and alcohol use, all 5 variables were independently predictive of survival duration (risk ratio: symptom severity 1.28, TNM 1.33, comorbidity 1.80, age 1.47, alcohol use 1.09). Appropriately defined symptom variables contain important prognostic information, which is independent of the TNM system. Therefore symptoms provide an index of biologic behavior in head and neck cancer.

Clinical-severity staging system for oral cavity cancer: five-year survival rates

The objective of this research is to improve the classification and survival estimates for patients with oral cavity cancer by combining cancer symptom severity and comorbidity with the current TNM staging system. The study design is a retrospective medical record review that uses explicit coding criteria. The medical records of 277 patients receiving initial treatment at the Washington University Medical Center between 1980 and 1989 were reviewed. Multivariate analysis identified patient factors that significantly affected 5-year survival. These patient factors, symptom severity and comorbidity, were combined with TNM to create a composite clinical-severity staging system. The overall 5-year survival rate was 46% (128/277). Survival rates by TNM stage were as follows: stage I, 72% (36/50); II, 54% (45/84); III, 37% (24/65); and IV, 29% (23/78) (chi2 = 25.27, P = 0.001). When patients were grouped according to the clinical-severity staging system, survival rates were as follows: stage I, 77% (33/43); II, 56% (45/80); III, 42% (43/103); and IV, 14% (7/51) (chi2 = 40.62, P = 0.001). Survival estimates can be improved by adding carefully studied and suitably defined patient variables to the TNM system. The current TNM staging system for oral cavity cancer is based solely on the morphologic description of the tumor and disregards the clinical condition of the patient. Patient factors, such as cancer symptom severity and comorbidity, have a significant impact on survival. Continued exclusion of patient factors leads to imprecision in prognostic estimates and hinders interpretation of clinical studies.

Carcinoma of the tonsillar fossa: prognostic factors and long-term therapy outcome

PURPOSE

To identify prognostic parameters and evaluate the therapeutic outcomes for patients with carcinoma of the tonsillar fossa treated with three treatment modalities.

METHODS AND MATERIALS

The results of therapy are reported in 384 patients with histologically proven epidermoid carcinoma of the tonsillar fossa; 154 were treated with irradiation alone (55-70 Gy), 144 with preoperative radiation therapy (20-40 Gy), and 86 with postoperative irradiation (50-60 Gy). The operation in all but four patients in the last two groups consisted of an en bloc radical tonsillectomy with ipsilateral lymph node dissection.

RESULTS

Treatment modality and total irradiation doses had no impact on survival. Actuarial 10-year disease-free survival rates were 65% for patients with T1 tumors, 60% for T2, 60% for T3, and 30% for T4 disease. Patients with no cervical lymphadenopathy or with a small metastatic lymph node (N1) had better disease-free survival (60% and 70%, respectively) at 5 years than those with large or fixed lymph nodes (30%). Primary tumor recurrence (local, marginal) rates in the T1, T2, and T3 groups were 20-25% in patients treated with irradiation and surgery and 31% for those treated with irradiation alone (difference not statistically significant). In patients with T4 disease treated with surgery and postoperative irradiation, the local failure rate was 32% compared with 86% with low-dose preoperative irradiation and 47% with irradiation alone (p = 0.03). The overall recurrence rates in the neck were 10% for N0 patients, 25% for N1 and N2, and 35-40% for patients with N3 cervical lymph nodes, without significant differences among the various treatment groups. The incidence of contralateral neck recurrences was 8% with the various treatment modalities. On multivariate analysis the only significant factors for local tumor control and disease-free survival were T and N stage (p = 0.04-0.001). Fatal complications were noted in 7 of 144 (5%) patients treated with preoperative irradiation and surgery, 2 of 86 (2%) of those receiving postoperative irradiation, and 2 of 154 (1.3%) patients treated with radiation therapy alone. Other moderate or severe nonfatal sequelae were noted in 30% of the patients treated with preoperative irradiation and surgery, in 53% treated with postoperative irradiation, and in 19% receiving radiation therapy alone.

CONCLUSION

Primary tumor and neck node stage are the only significant prognostic factors influencing locoregional tumor control and disease-free survival. Treatment modality had no significant impact on outcome. Radiation therapy remains the treatment of choice for patients with stage T1-T2 carcinoma of the tonsillar fossa. In patients with T3-T4 tumors and good general condition, combination surgery and postoperative irradiation offers better tumor control than single-modality and preoperative irradiation procedures, but with greater morbidity.

Validation and predictive power of Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis classes for malignant glioma patients: a report using RTOG 90-06

PURPOSE

The recursive partitioning analysis (RPA) classes for malignant glioma patients were previously established using data on over 1500 patients entered on Radiation Therapy Oncology Group (RTOG) clinical trials. The purpose of the current analysis was to validate the RPA classes with a new dataset (RTOG 90-06), determine the predictive power of the RPA classes, and establish the usefulness of the database norms for the RPA classes.

PATIENTS AND METHODS

There are six RPA classes for malignant glioma patients that comprise distinct groups of patients with significantly different survival outcome. RTOG 90-06 is a randomized Phase III study of 712 patients accrued from 1990 to 1994. The minimum potential follow-up is 18 months. The treatment arms were combined for the purpose of this analysis. There were 84, 13, 105, 240, 150, and 23 patients in the RPA Classes I-VI from RTOG 90-06, respectively.

RESULTS

The median survival times (MST) and 2-year survival rates for the six RPA classes in RTOG 90-06 are compared to those previously published. The MST and 2-year survival rates for the RTOG RPA classes were within 95% confidence intervals of the 90-06 estimates for Classes I, III, IV, and V. The RPA classes explained 43% of the variation (squared error loss). By comparison, a Cox model explains 30% of the variation. The RPA classes within RTOG 90-06 are statistically distinct with all comparisons exceeding 0.0001, except those involving Class II. A survival analysis from a prior RTOG study indicated that 72.0 Gy had superior outcome to literature controls; analysis of this data by RPA classes indicates the survival results were not superior to the RTOG database norms.

CONCLUSION

The validity of the model is verified by the reliability of the RPA classes to define distinct groups with respect to survival. Further evidence is given by prediction of MST and 2-year survival for all classes except Class II. The RPA classes explained a good portion of the variation in survival outcome in the data. Lack of correlation in RPA Class II between datasets may be an artifact of the small sample size or an indication that this class is not distinct. The validation of the RPA classes attests to their usefulness as historical controls for the comparison of future Phase II results.

Clinical-severity staging system for oropharyngeal cancer: five-year survival rates

OBJECTIVE

To improve the classification and survival estimates for patients with oropharyngeal cancer by combining cancer symptom severity and comorbidity with the current TNM cancer staging system.

DESIGN

Retrospective medical record review using explicit coding criteria.

SETTING

University medical center.

PATIENTS AND METHODS

Two hundred ninety-six patients receiving initial treatment from January 1, 1980, to December 31, 1989. Multivariate analysis identified patient factors that had a significant impact on 5-year survival. These patient factors, symptom severity and comorbidity, were combined with cancer stage to create a composite clinical-severity staging system.

MAIN OUTCOME MEASURE

Five-year survival.

RESULTS

The overall 5-year survival rate was 38% (111/ 296). Survival by TNM cancer stage was 67% (18/27) for stage I, 46% (24/52) for stage II, 31% (26/85) for stage III, and 32% (43/132) for stage IV (chi2=10.84; P=.001). When patients were grouped according to the clinical-severity staging system, survival rates were 70% (16 of 23) for stage A, 47% (71 of 152) for stage B, 27% (18 of 67) for stage C, and 11% (6 of 54) for stage D (chi2=34.49; P=.001).

CONCLUSIONS

Survival estimates can be improved by adding carefully studied and suitably defined patient variables to the TNM cancer stage. The current TNM cancer staging system for oropharyngeal cancer is based solely on the morphologic description of the tumor and disregards the clinical condition of the patient. Cancer symptom severity and comorbidity have a significant impact on survival. Continued exclusion of patient factors leads to imprecision in prognostic estimates and hinders interpretation of clinical studies.

Subgenual prefrontal cortex abnormalities in mood disorders

Pathological disturbances of mood may follow a 'bipolar' course, in which normal moods alternate with both depression and mania, or a 'unipolar' course, in which only depression occurs. Both bipolar and unipolar disorders can be heritable illnesses associated with neurochemical, neuroendocrine and autonomic abnormalities. The neurobiological basis for these abnormalities has not been established. Using positron emission tomographic (PET) images of cerebral blood flow and rate of glucose metabolism to measure brain activity, we have now localized an area of abnormally decreased activity in the prefrontal cortex ventral to the genu of the corpus callosum in both familial bipolar depressives and familial unipolar depressives. This decrement in activity was at least partly explained by a corresponding reduction in cortical volume, as magnetic resonance imaging (MRI) demonstrated reductions in the mean grey matter volume in the same area of 39 and 48% in the bipolar and unipolar samples, respectively. This region has previously been implicated in the mediation of emotional and autonomic responses to socially significant or provocative stimuli, and in the modulation of the neurotransmitter systems targeted by antidepressant drugs.

Race and prognosis of brain tumor patients entering multicenter clinical trials. A report from the Radiation Therapy Oncology Group

We investigated the possible influence of race on the survival of patients with malignant gliomas enrolled in three consecutive trials of the Radiation Therapy Oncology Group (RTOG) retrospectively using the group's statistical database. There were no statistical differences between the survival rates for black patients with glioblastoma multiforme (GBM) and those for the white patients. The limited influence of therapy on this disease may be responsible in part for this result.

Feasibility and acceptability of a proposed infant feeding intervention trial for the prevention of type I diabetes

OBJECTIVE

To determine the feasibility of a randomized double-blind controlled trial of an infant formula without intact cow's-milk protein for preventing type I diabetes in high-risk children.

RESEARCH DESIGN AND METHODS

We surveyed 83 people who either were parents of a child with type I diabetes or were pregnant women with type I diabetes in the ambulatory diabetes and obstetrics clinics in a university hospital. After a written and verbal description of the cow's milk-diabetes hypothesis, participants were asked to sign a sham consent form. A questionnaire designed to explore factors affecting their decision to either sign or not sign the consent form, as well as infant-feeding patterns, was subsequently administered.

RESULTS

Overall, 69.9% (95% confidence interval, 60.0-79.8%) consented to participation in the proposed randomized trial. The decision to consent was not affected by the degree of belief in the cow's milk-diabetes hypothesis, the child's risk of diabetes, the respondent's demographic data, or infant feeding habits.

CONCLUSIONS

A randomized feeding intervention study is an acceptable and feasible way to determine whether avoidance of cow's-milk protein during the first 6 months of life prevents type I diabetes in North American children.

Stereotactic external beam irradiation using a linear accelerator: the Washington University experience

From February 1989 to December 1993, 139 patients with a variety of brain lesions were treated with stereotactic external beam irradiation using a 6MV linear accelerator. The largest group consisted of patients with recurrent brain metastases (n = 46). Twenty seven patients had malignant gliomas, most of which were recurrent. Several benign conditions were treated, including arteriovenous malformations (n = 27), acoustic neuromas (n = 9), meningiomas (n = 7), and pituitary adenomas (n = 2). Durable responses were seen in the majority of patients with transient, mild, side effects. This experience suggests that stereotactic external beam irradiation is a safe, reliable, and effective method for non-invasive treatment of selected patients with small, localized brain lesions.

Blood flow changes in human somatosensory cortex during anticipated stimulation

Positron emission tomography (PET) measurements of brain blood flow were used to monitor changes in the human primary and secondary somatosensory cortices during the period when somatosensory stimuli were expected. In anticipation of either focal or innocuous touching, or localized, painful shocks, blood flow decreased in parts of the primary somatosensory cortex map located outside the representation of the skin area that was the target of the expected stimulus. Specifically, attending to an impending stimulus to the fingers produced a significant decrease in blood flow in the somatosensory zones for the face, whereas attending to stimulation of the toe produced decreases in the zones for the fingers and face. Decreases were more prominent in the side ipsilateral to the location of the expected stimulus. No significant changes in blood flow occurred in the region of the cortex representing the skin locus of the awaited stimulation. These results are concurrent with a model of spatial attention in which potential signal enhancement may rely on generalized suppression of background activity.