One-Year and 18-Month Outcomes in nAMD Patient Eyes Switched to Brolucizumab Alone versus to Brolucizumab Alternating with Other Anti-VEGF Agents

Objective

Retrospective, real-world study to evaluate visual acuity (VA), anti-vascular endothelial growth factor (anti-VEGF) injection intervals, and central macular thickness (CMT) in neovascular age-related macular degeneration (nAMD) eyes switched to brolucizumab only or to brolucizumab alternating with another anti-VEGF.

Methods

The overall study population comprised eyes that were given ≥1 brolucizumab injection between 1 October 2019 and 30 November 2021. The brolucizumab-only (BRO) cohort consisted of prior anti-VEGF-treated eyes treated exclusively with ≥3 brolucizumab injections over ≥12 or ≥18 months; the alternating brolucizumab (ALT) cohort comprised prior anti-VEGF-treated eyes treated with ≥2 brolucizumab injections and ≥1 other anti-VEGF over ≥12 or ≥18 months.

Results

A total of 482 eyes received ≥1 brolucizumab injection during the study period. Mean VA changes from baseline were -1.1±15.1 letters (BRO cohort; n = 174) and 1.3±13.0 letters (ALT cohort; n = 47) at Month 12, and 0.0±13.5 letters (BRO cohort; n = 95) and -7.3±17.2 letters (ALT cohort; n = 29) at Month 18. Mean changes in injection intervals were +26.9±48.1 days (BRO cohort) and +11.1±17.3 days (ALT cohort) at Month 12 and +36.3±52.3 days (BRO cohort) and +14.0±19.9 days (ALT cohort) at Month 18. Mean changes in CMT were -35.2±108.1 μm (BRO cohort) and -31.5±91.2 μm (ALT cohort) at Month 12 and -38.9±75.0 μm (BRO cohort) and -9.0±59.9 μm (ALT cohort) at Month 18. Intraocular inflammation-related adverse events were recorded in 22/482 (4.6%) eyes.

Conclusion

Treatment with either brolucizumab alone or brolucizumab alternating with another anti-VEGF can preserve vision, reduce CMT, and extend anti-VEGF injection intervals in patients with nAMD.

In Vivo Optical Characterization of Middle Ear Effusions and Biofilms During Otitis Media

Otitis media (OM), a common ear infection, is characterized by the presence of an accumulated middle ear effusion (MEE) in a normally air-filled middle ear cavity. While assessing the MEE plays a critical role in the overall management of OM, identifying and examining the MEE is challenging with the current diagnostic tools since the MEE is located behind the semi-opaque eardrum. The objective of this cross-sectional, observational study is to non-invasively visualize and characterize MEEs and bacterial biofilms in the middle ear. A portable, handheld, otoscope-integrated optical coherence tomography (OCT) system combined with novel analytical methods has been developed. In vivo middle ear OCT images were acquired from 53 pediatric subjects (average age of 3.9 years; all awake during OCT imaging) diagnosed with OM and undergoing a surgical procedure (ear tube surgery) to aspirate the MEE and aerate the middle ear. In vivo middle ear OCT acquired prior to the surgery was compared with OCT of the freshly extracted MEEs, clinical diagnosis, and post-operative evaluations. Among the subjects who were identified with the presence of MEEs, 89.6% showed the presence of the TM-adherent biofilm in in vivo OCT. This study provides an atlas of middle ear OCT images exhibiting a range of depth-resolved MEE features, which can only be visualized and assessed non-invasively through OCT. Quantitative metrics of OCT images acquired prior to the surgery were statistically correlated with surgical evaluations of MEEs. Measurements of MEE characteristics will provide new readily available information that can lead to improved diagnosis and management strategies for the highly prevalent OM in children.

Switching to brolucizumab: injection intervals and visual, anatomical and safety outcomes at 12 and 18 months in real-world eyes with neovascular age-related macular degeneration

BACKGROUND

The anti-vascular endothelial growth factor (anti-VEGF) injection interval influences treatment burden and compliance in neovascular age-related macular degeneration (nAMD). This real-world study investigates visual acuity (VA), injection-interval extension, central macular thickness (CMT) and safety in nAMD eyes switched to the anti-VEGF agent brolucizumab and followed for up to 18 months.

METHODS

This retrospective study included patients with nAMD who were switched from other anti-VEGF agents to brolucizumab only. Patient eyes were grouped into three nested cohorts with the overall cohort receiving ≥ 1 brolucizumab injection, the second receiving ≥ 3 brolucizumab injections with a follow-up period of ≥ 12 months and the third cohort receiving ≥ 3 brolucizumab injections with a follow-up period of ≥ 18 months. Study endpoints included changes from baseline at 12 or 18 months in VA, injection intervals, and CMT. Sub-group analyses were conducted using baseline injection interval length or baseline VA as qualifiers.

RESULTS

Overall, 482 eyes received ≥ 1 brolucizumab injection; 174 eyes received ≥ 3 brolucizumab injections with ≥ 12 months of follow-up, and 95 eyes received ≥ 3 brolucizumab injections with ≥ 18 months of follow-up. VA (mean [95% confidence intervals]) remained stable relative to baseline after 12 months (- 1.1 [- 3.7, 1.6] letters; p = 0.42) and 18 months (0.0 [- 3.1, 3.1] letters; p = 0.98) of brolucizumab treatment, respectively, and pre-switch injection intervals or baseline VA had no notable effect. Following the switch to brolucizumab, injection intervals were extended from baseline to month 12 by 26.9 (19.7, 34.0) days (p < 0.0001), and eyes with pre-switch injection intervals < 8 weeks were able to have their injection intervals extended by 23.6 days longer than eyes with pre-switch injection intervals ≥ 8 weeks. At 18 months, injection intervals were extended by 36.3 (25.6, 46.9) days (p < 0.0001) compared to baseline. Following switch to brolucizumab, CMT was reduced at both 12 and 18 months (12 months: - 35.2 (- 51.7, - 18.8) µm, p < 0.0001; 18 months: - 38.9 (- 54.3, - 22.0) µm, p < 0.0001). Intraocular inflammation-related adverse events were reported in 4.6% of brolucizumab-treated eyes.

CONCLUSIONS

This real-world study demonstrates that injection intervals may be significantly extended with maintained vision and reduced CMT in nAMD eyes switching to brolucizumab therapy from other anti-VEGFs.

Automated classification of otitis media with OCT: augmenting pediatric image datasets with gold-standard animal model data

Otitis media (OM) is an extremely common disease that affects children worldwide. Optical coherence tomography (OCT) has emerged as a noninvasive diagnostic tool for OM, which can detect the presence and quantify the properties of middle ear fluid and biofilms. Here, the use of OCT data from the chinchilla, the gold-standard OM model for the human disease, is used to supplement a human image database to produce diagnostically relevant conclusions in a machine learning model. Statistical analysis shows the datatypes are compatible, with a blended-species model reaching ∼95% accuracy and F1 score, maintaining performance while additional human data is collected.

In vivo dynamic characterization of the human tympanic membrane using pneumatic optical coherence tomography

Decreased mobility of the human eardrum, the tympanic membrane (TM), is an essential indicator of a prevalent middle ear infection. The current diagnostic method to assess TM mobility is via pneumatic otoscopy, which provides subjective and qualitative information of subtle motion. In this study, a handheld spectral-domain pneumatic optical coherence tomography system was developed to simultaneously measure the displacement of the TM, air pressure inputs applied to a sealed ear canal, and to perform digital pneumatic otoscopy. A novel approach based on quantitative parameters is presented to characterize spatial and temporal variations of the dynamic TM motion. Furthermore, the TM motions of normal middle ears are compared with those of ears with middle ear infections. The capability of noninvasively measuring the rapid motion of the TM is beneficial to understand the complex dynamics of the human TM, and can ultimately lead to improved diagnosis and management of middle ear infections.

Longitudinal optical coherence tomography to visualize the in vivo response of middle ear biofilms to antibiotic therapy

Studying the impact of antibiotic treatment on otitis media (OM), the leading cause of primary care office visits during childhood, is critical to develop appropriate treatment strategies. Tracking dynamic middle ear conditions during antibiotic treatment is not readily applicable in patients, due to the limited diagnostic techniques available to detect the smaller amount and variation of middle ear effusion (MEE) and middle ear bacterial biofilm, responsible for chronic and recurrent OM. To overcome these challenges, a handheld optical coherence tomography (OCT) system has been developed to monitor in vivo response of biofilms and MEEs in the OM-induced chinchilla model, the standard model for human OM. As a result, the formation of MEE as well as biofilm adherent to the tympanic membrane (TM) was longitudinally assessed as OM developed. Various types of MEEs and biofilms in the chinchilla model were identified, which showed comparable features as those in humans. Furthermore, the effect of antibiotics on the biofilm as well as the amount and type of MEEs was investigated with low-dose and high-dose treatment (ceftriaxone). The capability of OCT to non-invasively track and examine middle ear conditions is highly beneficial for therapeutic OM studies and will lead to improved management of OM in patients.

Automated classification platform for the identification of otitis media using optical coherence tomography

The diagnosis and treatment of otitis media (OM), a common childhood infection, is a significant burden on the healthcare system. Diagnosis relies on observer experience via otoscopy, although for non-specialists or inexperienced users, accurate diagnosis can be difficult. In past studies, optical coherence tomography (OCT) has been used to quantitatively characterize disease states of OM, although with the involvement of experts to interpret and correlate image-based indicators of infection with clinical information. In this paper, a flexible and comprehensive framework is presented that automatically extracts features from OCT images, classifies data, and presents clinically relevant results in a user-friendly platform suitable for point-of-care and primary care settings. This framework was used to test the discrimination between OCT images of normal controls, ears with biofilms, and ears with biofilms and middle ear fluid (effusion). Predicted future performance of this classification platform returned promising results (90%+ accuracy) in various initial tests. With integration into patient healthcare workflow, users of all levels of medical experience may be able to collect OCT data and accurately identify the presence of middle ear fluid and/or biofilms.

The interplay between single particle anisotropy and interparticle interactions in ensembles of magnetic nanoparticles

This paper aims to analyze the competition of single particle anisotropy and interparticle interactions in nanoparticle ensembles using a random anisotropy model. The model is first applied to ideal systems of non-interacting and strongly dipolar interacting ensembles of maghemite nanoparticles. The investigation is then extended to more complex systems of pure cobalt ferrite CoFe2O4 (CFO) and mixed cobalt-nickel ferrite (Co,Ni)Fe2O4 (CNFO) nanoparticles. Both samples were synthetized by the polyol process and exhibit the same particle size (DTEM ≈ 5 nm), but with different interparticle interaction strengths and single particle anisotropy. The implementation of the random anisotropy model allows investigation of the influence of single particle anisotropy and interparticle interactions, and sheds light on their complex interplay as well as on their individual contribution. This analysis is of fundamental importance in order to understand the physics of these systems and to develop technological applications based on concentrated magnetic nanoparticles, where single and collective behaviors coexist.

In vivo detection of nanometer-scale structural changes of the human tympanic membrane in otitis media

Otitis media (OM) is a common ear infection and a leading cause of conductive hearing loss in the pediatric population. Current technologies such as otoscopy, pneumatic otoscopy, tympanometry, and acoustic reflectometry are used to diagnose OM, which can reasonably diagnose the infection with a sensitivity and specificity of 50-90% and 60-90%, respectively. However, these techniques provide limited information about the physical architecture of the tympanic membrane (TM), or what may lie behind it. Here, we report the detection of nanometer-scale structural changes of the TM using nano-sensitive optical coherence tomography (nsOCT). In total, an image dataset from 65 pediatric subjects from three different groups (normal, acute OM, and chronic OM) and with longitudinal image-based analysis of ear infections were included in this study. The nsOCT data were correlated with physician diagnosis and with OCT thickness measurements and were found to be in good agreement with these results. We report that nsOCT detects in vivo structural deformations of the TM earlier than OCT alone, and enhances the detection sensitivity of OCT measurements. This unique technique for early detection of nano-scale structural modifications in the TM has the potential to aid in our understanding of microbiological effects, and possibly for early diagnosis and more effective treatment of OM.

Direct Analysis of Pathogenic Structures Affixed to the Tympanic Membrane during Chronic Otitis Media

Objective To characterize otitis media-associated structures affixed to the mucosal surface of the tympanic membrane (TM) in vivo and in surgically recovered in vitro samples. Study Design Prospective case series without comparison. Setting Outpatient surgical care center. Subjects and Methods Forty pediatric subjects scheduled for tympanostomy tube placement surgery were imaged intraoperatively under general anesthesia. Postmyringotomy, a portable optical coherence tomography (OCT) imaging system assessed for the presence of any biofilm affixed to the mucosal surface of the TM. Samples of suspected microbial infection-related structures were collected through the myringotomy incision. The sampled site was subsequently reimaged with OCT to confirm collection from the original image site on the TM. In vitro analysis based on confocal laser scanning microscope (CLSM) images of fluorescence in situ hybridization-tagged samples and polymerase chain reaction (PCR) provided microbiological characterization and verification of biofilm activity. Results OCT imaging was achieved for 38 of 40 subjects (95%). Images from 38 of 38 (100%) of subjects observed with OCT showed the presence of additional microbial infection-related structures. Thirty-four samples were collected from these 38 subjects. CLSM images provided evidence of clustered bacteria in 32 of 33 (97%) of samples. PCR detected the presence of active bacterial DNA signatures in 20 of 31 (65%) of samples. Conclusion PCR and CLSM analysis of fluorescence in situ hybridization-stained samples validates the presence of active bacteria that have formed into a middle ear biofilm that extends across the mucosal layer of the TM. OCT can rapidly and noninvasively identify middle ear biofilms in subjects with severe and persistent cases of otitis media.

Pneumatic low-coherence interferometry otoscope to quantify tympanic membrane mobility and middle ear pressure

Pneumatic otoscopy to assess the mobility of the tympanic membrane (TM) is a highly recommended diagnostic method of otitis media (OM), a widespread middle ear infection characterized by the fluid accumulation in the middle ear. Nonetheless, limited depth perception and subjective interpretation of small TM displacements have challenged the appropriate and efficient examination of TM dynamics experienced during OM. In this paper, a pneumatic otoscope integrated with low coherence interferometry (LCI) was adapted with a controlled pressure-generating system to record the pneumatic response of the TM and to estimate middle ear pressure (MEP). Forty-two ears diagnosed as normal (n = 25), with OM (n = 10), or associated with an upper respiratory infection (URI) (n = 7) were imaged with a pneumatic LCI otoscope with an axial, transverse, and temporal resolution of 6 µm, 20 µm, and 1 msec, respectively. The TM displacement under pneumatic pressure transients (a duration of 0.5 sec with an intensity of ± 150 daPa) was measured to compute two metrics (compliance and amplitude ratio). These metrics were correlated with peak acoustic admittance and MEP from tympanometry and statistically compared via Welch's t-test. As a result, the compliance represents pneumatic TM mobility, and the amplitude ratio estimates MEP. The presence of a middle ear effusion (MEE) significantly decreased compliance (p<0.001). The amplitude ratio of the OM group was statistically less than that of the normal group (p<0.01), indicating positive MEP. Unlike tympanometry, pneumatic LCI otoscopy quantifies TM mobility as well as MEP regardless of MEE presence. With combined benefits of pneumatic otoscopy and tympanometry, pneumatic LCI otoscopy may provide new quantitative metrics for understanding TM dynamics and diagnosing OM.

Noninvasive in vivo optical coherence tomography tracking of chronic otitis media in pediatric subjects after surgical intervention

In an institutional review board-approved study, 25 pediatric subjects diagnosed with chronic or recurrent otitis media were observed over a period of six months with optical coherence tomography (OCT). Subjects were followed throughout their treatment at the initial patient evaluation and preoperative consultation, surgery (intraoperative imaging), and postoperative follow-up, followed by an additional six months of records-based observation. At each time point, the tympanic membrane (at the light reflex region) and directly adjacent middle-ear cavity were observed in vivo with a handheld OCT probe and portable system. Imaging results were compared with clinical outcomes to correlate the clearance of symptoms in relation to changes in the image-based features of infection. OCT images of most all participants showed the presence of additional infection-related biofilm structures during their initial consultation visit and similarly for subjects imaged intraoperatively before myringotomy. Subjects with successful treatment (no recurrence of infectious symptoms) had no additional structures visible in OCT images during the postoperative visit. OCT image findings suggest surgical intervention consisting of myringotomy and tympanostomy tube placement provides a means to clear the middle ear of infection-related components, including middle-ear fluid and biofilms. Furthermore, OCT was demonstrated as a rapid diagnostic tool to prospectively monitor patients in both outpatient and surgical settings.

Quantitative Pneumatic Otoscopy Using a Light-Based Ranging Technique

Otitis media is the leading cause of hearing loss in children. It is commonly associated with fluid in the ear, which can result in up to 45 dB of hearing loss for extended periods of time during a child's most important developmental years. Accurate assessment of middle ear effusions is an important part of understanding otitis media. Current technologies used to diagnose otitis media with effusion are pneumatic otoscopy, tympanometry, and acoustic reflectometry. While all of these techniques can reasonably diagnose the presence of an effusion, they provide limited information about the infection present behind the tympanic membrane.We have developed a technique based on low-coherence interferometry-a non-invasive optical ranging technique capable of sensing depth-resolved microscopic scattering features through the eardrum-to quantify eardrum thickness and integrity, as well as detect any effusion, purulence, or biofilm behind the tympanic membrane. In this manuscript, the technique is coupled with a pneumatic otoscope to measure minute deflections of the tympanic membrane from insufflation pressure stimuli. This results in quantitative measurements of tympanic membrane mobility, which may be used to gain a better understanding of the impact of infection on the membrane dynamics. A small pilot study of 15 subjects demonstrates the ability of pneumatic low-coherence interferometry to quantitatively differentiate normal ears from ears with effusions present. Analysis of the strengths and weaknesses of the technique, as well as focus areas of future research, is also discussed.

Fatty acid supplements improve hair coat condition in rhesus macaques

As captive rhesus macaques often exhibit hair loss, alopecia was quantified and behavior was recorded before, during, and after fatty acid supplementation in six macaques. Fatty acid treatment was associated with a decrease in alopecia and in self-grooming behavior. Therefore, fatty acids may be a viable treatment for alopecia in some captive primates.

Non-invasive optical assessment of viscosity of middle ear effusions in otitis media

Eustachian tube dysfunction can cause fluid to collect within the middle ear cavity and form a middle ear effusion (MEE). MEEs can persist for weeks or months and cause hearing loss as well as speech and learning delays in young children. The ability of a physician to accurately identify and characterize the middle ear for signs of fluid and/or infection is crucial to provide the most appropriate treatment for the patient. Currently, middle ear infections are assessed with otoscopy, which provides limited and only qualitative diagnostic information. In this study, we propose a method utilizing cross-sectional depth-resolved optical coherence tomography to noninvasively measure the diffusion coefficient and viscosity of colloid suspensions, such as a MEE. Experimental validation of the proposed technique on simulated MEE phantoms with varying viscosity and particulate characteristics is presented, along with some preliminary results from in vivo and ex vivo samples of human MEEs. In vivo Optical Coherence Tomography (OCT) image of a human tympanic membrane and Middle Ear Effusion (MEE) (top), with a CCD image of the tympanic membrane surface (inset). Below is the corresponding time-lapse M-mode OCT data acquired along the white dotted line over time, which can be analyzed to determine the Stokes-Einstein diffusion coefficient of the effusion.

Read My Lips: Brain Dynamics Associated with Audiovisual Integration and Deviance Detection

Information from different modalities is initially processed in different brain areas, yet real-world perception often requires the integration of multisensory signals into a single percept. An example is the McGurk effect, in which people viewing a speaker whose lip movements do not match the utterance perceive the spoken sounds incorrectly, hearing them as more similar to those signaled by the visual rather than the auditory input. This indicates that audiovisual integration is important for generating the phoneme percept. Here we asked when and where the audiovisual integration process occurs, providing spatial and temporal boundaries for the processes generating phoneme perception. Specifically, we wanted to separate audiovisual integration from other processes, such as simple deviance detection. Building on previous work employing ERPs, we used an oddball paradigm in which task-irrelevant audiovisually deviant stimuli were embedded in strings of non-deviant stimuli. We also recorded the event-related optical signal, an imaging method combining spatial and temporal resolution, to investigate the time course and neuroanatomical substrate of audiovisual integration. We found that audiovisual deviants elicit a short duration response in the middle/superior temporal gyrus, whereas audiovisual integration elicits a more extended response involving also inferior frontal and occipital regions. Interactions between audiovisual integration and deviance detection processes were observed in the posterior/superior temporal gyrus. These data suggest that dynamic interactions between inferior frontal cortex and sensory regions play a significant role in multimodal integration.

Noninvasive depth-resolved optical measurements of the tympanic membrane and middle ear for differentiating otitis media

OBJECTIVE/HYPOTHESIS

In this study, optical coherence tomography (OCT) is used to noninvasively and quantitatively determine tympanic membrane (TM) thickness and the presence and thickness of any middle-ear biofilm located behind the TM. These new metrics offer the potential to differentiate normal, acute, and chronic otitis media (OM) infections in pediatric subjects.

STUDY DESIGN

Case series with comparison group.

METHODS

The TM thickness of 34 pediatric subjects was acquired using a custom-built, handheld OCT system following a traditional otoscopic ear exam.

RESULTS

Overall thickness (TM and any associated biofilm) was shown to be statistically different for normal, acute, and chronic infection groups (normal-acute and normal-chronic: P value < 0.001; acute-chronic: P value = 0.0016). Almost all observed scans from the chronic group had an accompanying biofilm structure. When the thickness of the TM and biofilm were considered separately in chronic OM, the chronic TM thickness correlated with the normal group (P value = 0.68) yet was still distinct from the acute OM group (P value < 0.001), indicating that the TM in chronic OM returns to relatively normal thickness levels.

CONCLUSION

Identifying these physical changes in vivo provides new metrics for noninvasively and quantitatively differentiating normal, acute, and chronic OM. This new diagnostic information has the potential to assist physicians to more effectively and efficiently screen, manage, and refer patients based on quantitative data.

LEVEL OF EVIDENCE

4.

Investigation of bacterial biofilm in the human middle ear using optical coherence tomography and acoustic measurements

Children with chronic otitis media (OM) often have conductive hearing loss which results in communication difficulties and requires surgical treatment. Recent studies have provided clinical evidence that there is a one-to-one correspondence between chronic OM and the presence of a bacterial biofilm behind the tympanic membrane (TM). Here we investigate the acoustic effects of bacterial biofilms, confirmed using optical coherence tomography (OCT), in adult ears. Non-invasive OCT images are collected to visualize the cross-sectional structure of the middle ear, verifying the presence of a biofilm behind the TM. Wideband measurements of acoustic reflectance and impedance (0.2-6 [kHz]) are used to study the acoustic properties of ears with confirmed bacterial biofilms. Compared to known acoustic properties of normal middle ears, each of the ears with a bacterial biofilm has an elevated power reflectance in the 1 to 3 [kHz] range, corresponding to an abnormally small resistance (real part of the impedance). These results provide assistance for the clinical diagnosis of a bacterial biofilm, which could lead to improved treatment of chronic middle ear infection and further understanding of the impact of chronic OM on conductive hearing loss. This article is part of a special issue entitled "MEMRO 2012".

Measuring environmental stress in East Greenland polar bears, 1892-1927 and 1988-2009: what does hair cortisol tell us?

Hair sampled from 96 East Greenland polar bears (Ursus maritimus) over the periods 1892-1927 and 1988-2009 was analyzed for cortisol as a proxy to investigate temporal patterns of environmental stress. Cortisol concentration was independent of sex and age, and was found at significantly higher (p<0.001) concentrations in historical hair samples (1892-1927; n=8) relative to recent ones (1988-2009; n=88). In addition, there was a linear time trend in cortisol concentration of the recent samples (p<0.01), with an annual decrease of 2.7%. The recent hair samples were also analyzed for major bioaccumulative, persistent organic pollutants (POPs). There were no obvious POP related time trends or correlations between hair cortisol and hair POP concentrations. Thus, polar bear hair appears to be a relatively poor indicator of the animal's general POP load in adipose tissue. However, further investigations are warranted to explore the reasons for the temporal decrease found in the bears' hair cortisol levels.

Associations between complex OHC mixtures and thyroid and cortisol hormone levels in East Greenland polar bears

The multivariate relationship between hair cortisol, whole blood thyroid hormones, and the complex mixtures of organohalogen contaminant (OHC) levels measured in subcutaneous adipose of 23 East Greenland polar bears (eight males and 15 females, all sampled between the years 1999 and 2001) was analyzed using projection to latent structure (PLS) regression modeling. In the resulting PLS model, most important variables with a negative influence on cortisol levels were particularly BDE-99, but also CB-180, -201, BDE-153, and CB-170/190. The most important variables with a positive influence on cortisol were CB-66/95, α-HCH, TT3, as well as heptachlor epoxide, dieldrin, BDE-47, p,p'-DDD. Although statistical modeling does not necessarily fully explain biological cause-effect relationships, relationships indicate that (1) the hypothalamic-pituitary-adrenal (HPA) axis in East Greenland polar bears is likely to be affected by OHC-contaminants and (2) the association between OHCs and cortisol may be linked with the hypothalamus-pituitary-thyroid (HPT) axis.

Determination of the relevant magnetic interactions in low-dimensional molecular materials: the fundamental role of single crystal high frequency EPR

A new one-dimensional copper(II) complex with formula [Cu(hfac)(2)(N(3)TEMPO)](n) (hfac = hexafluoroacetylacetonate and N(3)TEMPO = 4-azido-2,2,6,6-tetramethylpiperidine-1-oxyl) has been synthesized and investigated by X-ray crystallography, magnetometry and multifrequency single crystal EPR. The system crystallizes in the P1 space group with two non equivalent copper(II) ions in the unit cell, the two nitroxide radicals being coordinated to Cu(1) in axial positions. The copper(II) ions are bridged by N(3)TEMPO radicals resulting in a zig-zag chain structure. The magnetic susceptibility data were at first satisfactorily modeled assuming an alternating spin chain along the monodimensional covalent skeleton, with a ferromagnetic interaction between Cu(1) and the nitroxide moieties and a weaker antiferromagnetic interaction between these and Cu(2) (J(1) = -13.8 cm(-1), J(2) = +2.4 cm(-1)). However, single crystal EPR studies performed at the X- and W-band clearly demonstrate that the observed magnetic monodimensional character of the complex is actually due to the intermolecular contacts involving N(3)TEMPO ligands. This prompted us to fit the magnetic data using a consistent model, pointing out the fundamental role of single crystal EPR data in defining a correct model to describe the magnetic properties of molecular low dimensional systems.

Cortisol levels in hair of East Greenland polar bears

To demonstrate the ability to assess long-term hypothalamic-pituitary-adrenocortical (HPA) axis activity in polar bears (Ursus maritimus), a pilot study was conducted in which cortisol concentrations was analyzed in hair from 7 female (3-19 years) and 10 male (6-19 years) East Greenland polar bears sampled in 1994-2006. The hair was chosen as matrix as it is non-invasive, seasonally harmonized, and has been validated as an index of long-term changes in cortisol levels. The samples were categorized according to contamination: eight were clean (2 females, 6 males), 5 had been contaminated with bear blood (2 F, 3 M), and 4 with bear fat (3 F, 1 M). There was no significant difference in cortisol concentration between the three categories after external contamination was removed. However, contaminated hair samples should be cleaned before cortisol determination. Average hair cortisol concentration was 8.90 pg/mg (range: 5.5 to 16.4 pg/mg). There was no significant correlation between cortisol concentration and age (p=0.81) or sampling year (p=0.11). However, females had higher mean cortisol concentration than males (females mean: 11.0 pg/mg, males: 7.3 pg/mg; p=0.01). The study showed that polar bear hair contains measurable amounts of cortisol and that cortisol in hair may be used in studies of long-term stress in polar bears.

Magnetic studies of CoFe2O4/SiO2 aerogel and xerogel nanocomposites

The evolution of the structural and magnetic properties of nanocomposites formed by cobalt ferrite particles dispersed in xerogel and aerogel silica matrices (CoFe2O4/SiO2) have been studied as a function of the temperature of preparation and the amount of ferrite dispersed in the matrix. Wet samples with different amounts of CoFe2O4 in SiO2 matrix were prepared by sol-gel process in monolithic form. Xerogel and aerogel samples were prepared by controlled and hypercritical drying, respectively, and heated at various temperatures between 300 and 1100 degrees C. Superparamagnetic behavior has been observed by magnetization studies at room temperature for xerogels prepared at low temperature. Aerogel samples showed significant superparamagnetic fractions for all thermal treatment temperatures as determined by Mössbauer spectroscopy. Magnetization of the nanocomposites at 10 KOe applied field varied from 1 to 19 emu/g and the coercivity from 90 to 2320 Oe, respectively, for the different morphologies and textures of the analyzed material. The results show that besides the magnetization and coercivity depend on crystallite size, parameters such as ferrite content, porosity and drying conditions greatly influence the nanocomposite magnetic behavior.

Standard Cochlear Implantation of Adults With Residual Low-Frequency Hearing

OBJECTIVE

This study compared preoperative and postoperative cochlear implant benefit in subjects with steeply sloping high-frequency hearing losses (HLs) who were implanted with standard long cochlear implant electrodes to: 1) determine the effect of etiology, 2) compare outcomes in studies exploring the use of combined electrical and acoustic stimulation, and 3) compare outcomes in patients implanted using standard criteria.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Nine adults with steeply sloping high-frequency congenital (n=2) or acquired (n=7) bilateral sensorineural HL. All pure-tone audiograms fit the criteria for trials of a short electrode aimed at preserving low-frequency acoustic hearing.

INTERVENTION

Subjects received full insertion of a standard cochlear implant long electrode in the poorer ear.

MAIN OUTCOME MEASURES

Preoperative versus postoperative audiograms, word and sentence recognition in quiet and noise.

RESULTS

Patients with progressive acquired HLs experienced significantly improved speech understanding in quiet and in noise with the cochlear implant, especially when combined with hearing aid use in the contralateral ear. Patients with congenital HLs experienced little or no improvement in the implanted ear when tested with the implant alone, but achieved some benefit when the implant was combined with a hearing aid in the nonimplanted ear.

CONCLUSION

Based on this small sample, patients with acquired steeply sloping high-frequency HLs obtain significant benefit from cochlear implantation with standard long electrodes. In progressive losses, full insertion of a long electrode would be preferable to a short electrode because acoustic hearing may diminish over time. In contrast, patients with congenital losses may not benefit from long electrodes, and might be better served by implanting a short electrode, thereby allowing use of low-frequency acoustic stimulation.

Tryptophan hydroxylase-2 gene polymorphisms in rhesus monkeys: association with hypothalamic-pituitary-adrenal axis function and in vitro gene expression

Tryptophan hydroxylase-2 (TPH2) is a newly identified second form of TPH responsible for serotonin synthesis in the brain and has been increasingly implicated as a contributor to the etiology of various psychiatric disorders. In this study, we have identified the constellation of polymorphisms in rhesus monkey TPH2 and investigated genotype/phenotype association as well as gene expression effects of specific polymorphisms. Genomic DNA was obtained from 247 rhesus monkeys, among which 24 had been previously examined for plasma cortisol level, dexamethasone suppression, and combined dexmethasone/ACTH challenge. Polymorphisms in all exons, splicing junctions and approximately 2 kb of the 5'-flanking region (5'-FR) of TPH2 were identified by sequencing. We identified 17 single nucleotide polymorphisms (SNPs) including two that are predictive of amino-acid change (25Pro>His and 75Gly>Ser, respectively), two mononucleotide repeats, one dinucleotide repeat, and one 159-bp insertion polymorphism. The 3'-UTR polymorphisms were significantly associated with hypothalamic-pituitary-adrenal (HPA) axis activity, especially 2051A>C, which was strikingly correlated with plasma cortisol level in the morning only (F=10.203, P=0.001). Luciferase reporter gene assays showed that the 3'-UTR polymorphisms and haplotypes had a profound effect on in vitro gene expression. Accordingly, these investigations revealed that polymorphisms in 3'-UTR of rhesus monkey TPH2 modulate HPA axis function, presumably by affecting levels of TPH2 expression.

Finite-size effects in single chain magnets: an experimental and theoretical study

The problem of finite-size effects in s=1/2 Ising systems showing slow dynamics of the magnetization is investigated introducing diamagnetic impurities in a Co2+-radical chain. The static magnetic properties have been measured and analyzed considering the peculiarities induced by the ferrimagnetic character of the compound. The dynamic susceptibility shows that an Arrhenius law is observed with the same energy barrier for the pure and the doped compounds while the prefactor decreases, as theoretically predicted. Multiple spin reversal has also been investigated.

A mu-opioid receptor single nucleotide polymorphism in rhesus monkey: association with stress response and aggression

Variations in the human mu-opioid receptor gene have driven exploration of their biochemical, physiological and pathological relevance. We investigated the existence of variations in the nonhuman primate mu-opioid receptor gene to determine whether nonhuman primates can model genotype/phenotype associations of relevance to humans. Similar to the A118G single nucleotide polymorphism (SNP) in the human mu-opioid receptor gene, a SNP discovered in the rhesus monkey mu-opioid receptor gene (C77G) alters an amino acid in the N-terminal arm of the receptor (arginine for proline at position 26). Two mu-opioid receptor coding regions isolated from a single heterozygous (C77/G77) rhesus monkey brain were expressed in HEK-293 cells and characterized in radioreceptor assays. Paralleling the findings of increased affinity of beta-endorphin by the A118G allele in the human, the rhesus monkey mu-opioid receptor protein derived from the G77-containing clone demonstrated a 3.5-fold greater affinity for beta-endorphin than the receptor derived from the C77-containing clone. An assay developed to assess the incidence of the C77G SNP in a behaviorally and physiologically characterized cohort of rhesus monkeys (n=32) indicated that 44% were homozygous for C77-containing alleles, 50% were heterozygous and 6% were homozygous for G77-containing alleles. The presence of G77-containing alleles was associated with significantly lower basal and ACTH-stimulated plasma cortisol levels (P<0.03-0.05 and P<0.02, respectively) and a significantly higher aggressive threat score (P<0.05) in vivo. In a cohort of 20 monkeys, a trend towards an inverse correlation between aggressive threat and plasma cortisol levels was observed. The findings suggest that mu-opioid receptor haplotypes in monkeys can contribute to individual variability in stress response and related aggression. The data support the use of nonhuman primates to investigate mu-opioid receptor genotype/phenotype relations of relevance to humans.

Early identification and cochlear implantation: critical factors for spoken language development

Documentation is lacking regarding the ability of congenitally deaf children to attain age-appropriate spoken language skills using a cochlear implant, and how early implantation must occur if such development is to be possible. Spoken language data are presented for infants who underwent implantation at 18 months of age or younger. Additional data are used to compare outcomes among children who differed in age at implantation. Data collected at Carle Clinic and Foundation Hospital were reviewed for 47 consecutively implanted children ranging in age from 9 to 48 months at implantation. These data were analyzed and compared by age-at-implantation groupings for speech perception skills, communication mode, and spoken language abilities. The groups differed dramatically in abilities. The best outcomes occurred in children who underwent implantation at or before 18 months of age. Several of these infants demonstrated age-appropriate spoken language skills. We conclude that early implantation is desirable. Children who undergo implantation as infants may develop language skills commensurate with those of their hearing peers.

Single nucleotide polymorphisms distinguish multiple dopamine transporter alleles in primates: implications for association with attention deficit hyperactivity disorder and other neuropsychiatric disorders

The human dopamine transporter (DAT) gene contains a variable number tandem repeat (VNTR; 40 bases/3 to >11 repeats) in the 3'-untranslated region (3'-UTR), resulting in multiple alleles categorized by length. The 10-copy allele has been associated with attention deficit hyperactivity disorder (ADHD), yet it accounts for only a small proportion of symptom variance. We investigated whether the rhesus monkey DAT gene contains a repeat sequence similar to the human and whether this region differs in the five most hyperactive and the five most sedate animals selected from a behaviorally characterized cohort (n = 22). A fixed number tandem repeat (FNTR; 39 bases/12 repeats) was observed in all animals. Accordingly, this FNTR is unbefitting an association of DAT transcript length with hyperactivity. However, sequence analysis revealed potential single nucleotide polymorphisms (SNPs), one of which affects a Bst1107I restriction site. We screened the entire cohort, confirmed that all the rhesus monkeys had repeat regions of the same length, and demonstrated that digestion with Bst1107I was sufficient to distinguish two distinct FNTR alleles. Bst1107I genotype was suggestive but not predictive of hyperactive behavior. Based on these data, we speculated that SNPs may exist in human DAT VNTR alleles. To support this hypothesis, we cloned a portion of a novel 10-repeat allele from the human gene containing an SNP that abolishes a DraI restriction site. We conclude that SNPs create a diversity of DAT alleles between individuals that may be greater than previously identified based solely on the length of the VNTR region, and that alleles of specific sequence may contribute to dopamine-related disorders.

Physiological correlates of self-injurious behavior in captive, socially-reared rhesus monkeys

This study examined the relationship between self-injurious behavior (SIB) in rhesus monkeys and several biological variables, including monoamine metabolites in cerebrospinal fluid (CSF) and circulating levels of ACTH, cortisol, and testosterone. Cisternal CSF and blood plasma samples were obtained from 23 individually housed male rhesus macaques, 14 of which had a veterinary record of self-inflicted wounding. CSF samples were analyzed for 5-hydroxyindole-3-acetic acid (5-HIAA), homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) using isocratic high-performance liquid chromatography with electrochemical detection (HPLC-EC). Plasma samples were analyzed for ACTH, cortisol, and testosterone using commercially available radioimmunoassays (RIAs). Rates of self-directed biting were determined by systematic observation of all monkeys. Monkeys with SIB did not differ from controls in their basal monoamine or gonadal activity. However, the SIB group showed consistently lower mean plasma cortisol levels than the control group. Plasma cortisol was negatively correlated with rates of self-directed biting. These results suggest a persistent dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in monkeys with SIB. It is not yet clear whether this phenomenon of low cortisol represents chronically reduced adrenocortical secretion under basal conditions or a difference in response to the mild stress of capture and chemical restraint. The implications of these findings will be discussed with respect to SIB in humans as well as post-traumatic stress disorder (PTSD), a condition characterized by pituitary-adrenocortical hypoactivity.

Techniques for collecting saliva from awake, unrestrained, adult monkeys for cortisol assay

Cortisol levels serve as an index of pituitary-adrenal activity in nonhuman primates. In adult monkeys, cortisol is normally measured in blood (typically requiring restraint or sedation) or urine (reflecting a state rather than point estimate). In contrast, saliva collection is less invasive than drawing blood and allows for repeated sampling within a short period of time. Although protocols exist for collecting saliva from young monkeys, these procedures are inadequate for awake, unrestrained adult animals. Our laboratory has developed two methods for collecting saliva from adult rhesus monkeys: a "screen" method, which involves licking screen-covered gauze, and a "pole" method, which involves sucking and chewing on an attached rope. Twenty-three adult male rhesus monkeys were used to evaluate these two methods. After a period of adaptation, saliva samples were collected from 21 of 23 subjects. Saliva collection was faster with the pole than with the screen method (P < 0.01), but the pole method was not suitable for some animals because of their tendency to bite off the attached rope. An analysis of 19 saliva samples revealed a mean cortisol concentration of 0.84 microg/dl (range 0.27-1.77 microg/dl). There was no statistically significant difference in cortisol value between methods used (P > 0.22). The influence of the flavoring on the cortisol assay was tested, and was found to have no significant effect (P > 0.28). Our results indicate that either technique can be used to safely collect saliva from unrestrained adult monkeys. Choice of technique will depend on the proclivities of individual monkeys.

Where's the ball? Two- and three-year-olds reason about unseen events

Children 2, 2 1/2, and 3 years of age engaged in a search task in which they opened 1 of 4 doors in an occluder to retrieve a ball that had been rolled behind the occluder. The correct door was determined by a partially visible wall placed behind the occluder that stopped the motion of the unseen ball. Only the oldest group of children was able to reliably choose the correct door. All children were able to retrieve a toy that had been hidden in the same apparatus if the toy was hidden from the front by opening a door. Analysis of the younger children's errors indicated that they did not search randomly but instead used a variety of strategies. The results are consistent with the Piagetian view that the ability to use representations to guide action develops slowly over the first years of life.

Effects of puzzle feeders on pathological behavior in individually housed rhesus monkeys

Self-injurious behavior (SIB) occurs in about 10% of individually housed monkeys. Monkeys with SIB bite their own bodies frequently, occasionally inflicting wounds as a result. At present, there is no standard treatment for this phenomenon. We examined the effectiveness of puzzle feeders in alleviating SIB in monkeys with a veterinary record of self-inflicted wounding. Two groups of monkeys (SIB and controls) were exposed to puzzle feeders for a 6 week period. Three levels of maze difficulty were examined. All monkeys used the feeders, but manipulation was confined to a brief period immediately after the feeders were loaded each day (1000 h) and was infrequent during the later sampling periods (1100 and 1400 h). The most difficult maze yielded a slight increase in usage at 1100 h. During the puzzle feeder phase, whole body stereotypies, including pacing and rocking, were reduced substantially in all monkeys at 1000 h when feeder manipulation was at its highest. However, self-biting in the SIB group was unchanged. Some monkeys actually bit themselves while manipulating the feeder. Long-term effects on abnormal behavior were assessed by comparing behavior during the feeder phase to baseline periods and to a phase in which the monkeys were provisioned with treats placed directly into their food box. Whole body stereotypies, including pacing, were reduced during both treatment phases; however, the reduction was associated only with the 1000 h observation. Puzzle feeders were more effective than treats alone in alleviating whole body stereotypies. Self-biting was unchanged through all phases. Puzzle feeders are beneficial from the perspective of eliciting manipulation. They also yield transient reductions in whole body stereotypy, an effect that does not extend beyond the direct manipulation of the feeder. Puzzle feeders are ineffective in alleviating self-injurious behavior.

Perception of novel changes in a familiar environment by socially-housed rhesus monkeys

Many animals appear to have a sophisticated spatial representation of their environment. The development of these representations depends on the joint abilities of discriminating novel objects and remembering their locations. Variations of a detection of novelty paradigm were used to determine the nature and limitations of these abilities in rhesus monkeys. Socially-housed monkeys at two facilities (UMASS Primate Laboratory and the New England Regional Primate Research Center) were exposed to novelty detection tasks using a vertical object grid arranged on a mesh wall of the animals' pens. Monkeys rapidly responded with increased exploration to the replacement of one familiar object with a novel object, to the movement of a familiar object to a novel location, and to the swapping of two familiar objects. However, novelty of object was more salient than novelty of place. In these initial studies, monkeys were given continuous access to the grid, and only one or two changes occurred on a given day. In subsequent studies, the task difficulty was varied either by reducing the length of grid exposure or increasing the number of changed objects/session. Surprisingly, only a reduction in length of exposure markedly affected novelty detecting abilities. Rhesus monkeys clearly possessed the dual novelty detecting abilities. These skills were negatively affected only when monkeys' access to the grid was limited. The procedure employed here provided a convenient way to assess complex cognitive abilities in a group setting. It also relied on rhesus monkeys' inherent attraction to novelty and required only their species-typical behavior for assessment.

Where's the ball? Two- and three-year-olds reason about unseen events

Children 2, 2 1/2, and 3 years of age engaged in a search task in which they opened 1 of 4 doors in an occluder to retrieve a ball that had been rolled behind the occluder. The correct door was determined by a partially visible wall placed behind the occluder that stopped the motion of the unseen ball. Only the oldest group of children was able to reliably choose the correct door. All children were able to retrieve a toy that had been hidden in the same apparatus if the toy was hidden from the front by opening a door. Analysis of the younger children's errors indicated that they did not search randomly but instead used a variety of strategies. The results are consistent with the Piagetian view that the ability to use representations to guide action develops slowly over the first years of life.

Can memory requirements account for species' differences in invisible displacement tasks?

We tested the hypothesis that poor performance on the Piagetian invisible displacement task is related to increased memory requirements. Rhesus monkeys and orangutans received 3 types of problems (invisible, visible, and no transfer problems) each containing a number of steps equivalent to that of standard invisible displacements. If failure to solve invisible displacements was due to increased memory requirements, then the primates should perform at chance level on all 3 problems. However, rhesus monkeys solved visible and no transfer problems, but not invisible transfer problems. Half of the orangutans solved all 3 transfer problems, although their performance on invisible transfer problems was lower than that on the other problems. A subsequent cuing phase led to improved performance, and a few monkeys solved invisible transfer problems.

Can memory requirements account for species' differences in invisible displacement tasks?

We tested the hypothesis that poor performance on the Piagetian invisible displacement task is related to increased memory requirements. Rhesus monkeys and orangutans received 3 types of problems (invisible, visible, and no transfer problems) each containing a number of steps equivalent to that of standard invisible displacements. If failure to solve invisible displacements was due to increased memory requirements, then the primates should perform at chance level on all 3 problems. However, rhesus monkeys solved visible and no transfer problems, but not invisible transfer problems. Half of the orangutans solved all 3 transfer problems, although their performance on invisible transfer problems was lower than that on the other problems. A subsequent cuing phase led to improved performance, and a few monkeys solved invisible transfer problems.

Electrically evoked potentials recorded in adult and pediatric CLARION implant users

The purpose of this study was to record electrical auditory brain stem responses (EABRs) and electrical middle latency responses (EMLRs) in the clinic from 3 adult CLARION Multi-Strategy Cochlear Implant subjects and to record EABRs in the operating room from 3 pediatric subjects. For 2 of the 3 adult subjects, EABR thresholds were within the subject's behavioral dynamic range, whereas 1 adult subject's EABR thresholds were either absent or, when present, exceeded the upper limit of the dynamic range. For this subject, EMLRs were absent or of poor morphology for the channels tested. Moreover, this subject was not able to understand speech in an open-set, auditory-only format. The EABR thresholds obtained with children were within the behavioral dynamic range for 2 of the 3 subjects, but exceeded comfortable loudness levels for 1 subject. Although the EABR thresholds were measured at stimulus levels that were audible for all subjects, the relationship of the EABR threshold levels to behavioral measures of loudness varied. Evoked potentials that originate more centrally, such as the EMLR, should be investigated further to determine the possible relationship to postimplant performance.

Object permanence in orangutans (Pongo pygmaeus) and squirrel monkeys (Saimiri sciureus)

The authors tested orangutans (Pongo pygmaeus) and squirrel monkeys (Saimiri sciureus) on object permanence tasks. In Experiment 1, orangutans solved all visible displacements and most invisible displacements except those involving movements into 2 boxes successively. In Experiment 2, performance of orangutans on double invisible displacements and control displacements (assessing simple strategies) was compared. Orangutans did not use the simple strategy of selecting the box visited last by the experimenter. Instead, poorer performance on double invisible displacements may have been related to increased memory requirements. In Experiment 3, squirrel monkeys were tested using the procedure of Experiment 1. Squirrel monkeys solved visible but did not comprehend invisible displacements. Results suggest that orangutans but not squirrel monkeys possess Stage 6 object permanence capabilities.

Vitrectomy in patients with decreased visual acuity secondary to asteroid hyalosis

PURPOSE

To evaluate the role of vitrectomy in patients with decreased visual acuity solely attributable to asteroid hyalosis.

METHOD

We retrospectively reviewed the records of patients with asteroid hyalosis and identified those who underwent vitrectomy for symptomatic asteroid hyalosis alone.

RESULTS

After vitrectomy, nine of 10 eyes (10 patients) had at least 1 line of improvement in nonstandardized best-corrected visual acuity. In one eye, vision was unchanged postoperatively. The average gain was 3.44 lines.

CONCLUSIONS

A small percentage of patients with asteroid hyalosis have decreased visual acuity caused solely or primarily by the asteroid hyalosis. Vitrectomy in these patients may alleviate symptoms and improve visual acuity.

Familial internal limiting membrane dystrophy. A new sheen retinal dystrophy

OBJECTIVE

To describe the clinicopathologic features of a previously unreported retinal dystrophy.

METHODS

Fourteen members of a single family were examined. The medical records of 2 additional family members were reviewed. Pathologic examination was performed on 2 eyes of 1 affected patient.

RESULTS

Five individuals were identified with a retinal dystrophy characterized by a glistening inner retinal surface throughout the posterior pole. Visual loss occurred in 3 affected patients in later life owing to superficial polycystic retinal edema and retinal folds. Electroretinographic testing revealed a selective diminution of the b wave. Pathologic examination revealed an abnormal internal limiting membrane with schisis cavities in the inner retina. Endothelial cell swelling, pericyte degeneration, and basement membrane thickening were present in retinal capillaries.

CONCLUSIONS

A previously unreported sheen retinal dystrophy is described. Pedigree analysis suggests an autosomal dominant mode of inheritance. A primary defect in Müller cells is the suspected, but unproved, cause. No effective treatment for the associated visual loss is known. The term familial internal limiting membrane dystrophy is proposed to describe this condition.

Tumor detachments of the retinal pigment epithelium in ocular/ central nervous system lymphoma

BACKGROUND

Ocular/central nervous system (CNS) lymphoma is a B-lymphocyte-derived tumor that characteristically involves the retina, optic nerve head, vitreous, and subretinal pigment epithelial areas of the eye.

METHOD

A retrospective analysis of clinical history and photography fluorescein angiography, histopathology, and immunocytochemistry of an untreated patient with ocular/CNS lymphoma was performed.

RESULTS

Tumor detachments of the retinal pigment epithelium (RPE) evolved into areas of RPE atrophy and depigmentation and disciform scars. Histopathologic studies disclosed foci of tumor cells in the wall of and around blood vessels and between the RPE and Bruch's membrane. Immunocytochemistry identified the malignant cells as B-lymphocytes.

CONCLUSIONS

The clinicopathologic features of a patient with ocular/CNS B-cell lymphoma are presented. Retinal pigment epithelium tumor detachments evolved to areas of RPE atrophy and depigmentation and disciform scars.

Multichannel cochlear implantation with inner ear malformation: case report of performance and management

A small percentage of children who have received the Nucleus multichannel cochlear implant have cochlear malformations of the inner ear and consequent partial electrode insertions. This case describes one child with a cochlear "common cavity" who received an implant at a young age. The case has been further complicated by a gradual malfunction of the electrode array, although the device has not failed completely. Despite the increase in the number of nonfunctional electrodes over time, the subject has continued to improve in auditory, speech production, and language development over a 30-month period. Methods are discussed for clinical monitoring of both performance and the stability of electrodes over time. The circumstances of this case reinforce the importance of postimplant collaboration with families and school staff and highlight the need for objective measures to evaluate both longitudinal changes in performance and device integrity.

Cohabitation alters vasopressin innervation and paternal behavior in prairie voles (Microtus ochrogaster)

The density of vasopressin-immunoreactive (AVP-ir) fibers in the lateral septum and lateral habenular nucleus is lower in prairie vole fathers--which display paternal behavior under natural conditions-than in sexually naive males. To see if these changes occur before or after the birth of pups, and whether they are related to changes in paternal behavior, we tested paternal responsiveness and measured AVP-ir fiber density in the lateral septum, lateral habenular nucleus, medial preoptic area, and paraventricular nucleus of the thalamus of sexually naive males and females (0P) and breeding pairs that were sacrificed shortly after mating (3P); during early (13P); or late gestation (21P); or after the birth of pups (6PP). Paternal responsiveness was increased in 3P males and reached a plateau in 13P males. AVP-ir fiber density did not change in the medial preoptic area and the paraventricular nucleus of the thalamus. The fiber density in the lateral septum and lateral habenular nucleus was affected differently in males and females. Among males, 3P animals had the lowest fiber density, while 13P and 6PP animals had an intermediate, and 0P and 21P animals the highest fiber density, whereas among females, no differences in fiber density were found. A second experiment showed that the decrease in fiber density in 3P males could be induced by cohabitation with an unfamiliar female but not by an unfamiliar male nor by relocation to a novel cage. The changes in AVP-ir fiber density shortly after mating suggest that these fibers may be involved in paternal responsiveness as well as in various other social behaviors that change after mating.

Sex and species differences in the vasopressin innervation of sexually naive and parental prairie voles, Microtus ochrogaster and meadow voles, Microtus pennsylvanicus

To study whether central systems that are implicated in functions associated with reproduction show different changes in males and females that become parental, the central vasopressin (AVP) innervation was compared in two species of voles: prairie voles, in which males and females provide parental care, and meadow voles, in which only females provide parental care. For both species, the densities of AVP-immunoreactive (AVP-ir) fibers in the lateral septum, lateral habenular nucleus, medial preoptic area and paraventricular nucleus of the thalamus were compared in males and females that were sexually inexperienced or had become parents 6 days before sacrifice. The lateral septum and lateral habenular nucleus presumably receive their projections from the bed nucleus of the stria terminalis and medial amygdaloid nucleus, while the other two areas presumably receive their projections from the suprachiasmatic nucleus. Differences between sexually naive and parental animals were found only in the presumed projections of the bed nucleus of the stria terminalis and medial amygdaloid nucleus. In both species, AVP-ir fiber densities in the lateral habenular nucleus and the lateral septum were much greater in males than in females regardless of parental state. In prairie voles, AVP-ir fiber density in the lateral septum and lateral habenular nucleus was reduced in parental males, while no differences were found in females. In parental meadow voles, the AVP-ir fiber density in the lateral septum did not show changes, while the fiber density in the lateral habenular nucleus was increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Auditory performance of children with cochlear ossification and partial implant insertion

The management of the profoundly deaf child with a cochlear implant poses a special challenge, particularly when total ossification of the cochlea is present. In this setting, insertion of an electrode array into a child's cochlea is often difficult. Our experience supports the feasibility of partial insertion of a multichannel implant into the basal turn of an ossified cochlea. Five children with ossified cochleae who had undergone partial implantation of a multichannel electrode were compared with the performance of matched controls who had full insertion of multichannel implants. No dramatic differences were detected during a 6- to 18-month follow-up period on selected test measures. These preliminary results suggest that active electrode number may exert a limited effect on performance with a cochlear implant. Drilling out the basal turn of an ossified cochlea in conjunction with partial insertion of a multichannel implant appears to be an acceptable surgical and rehabilitational alternative for placement of a cochlear implant prosthesis in children with complete cochlear ossification.

Do rhesus monkeys (Macaca mulatta) attribute knowledge and ignorance to others?

The ability of 4 rhesus monkeys (Macaca mulatta) to understand the causal connection between seeing and knowing was investigated. The subjects were tested to determine if they could discriminate between information provided by experimenters who randomly alternated between roles of guesser and knower. In a series of tests, the knower either hid food under 1 of 3 cups or watched as someone else hid the food. The guesser waited outside the room or covered her or his head until the food was hidden. The subjects watched this procedure occur but could not see which cup the food was hidden under. The knower pointed to the correct cup while the guesser pointed to an incorrect one. None of the macaques provided any evidence that they realized the different states of knowledge possessed by the guesser and knower. The results are consistent with the hypothesis that rhesus macaques are incapable of making inferences about the mental states of others.