Rash induced by anti-tumor necrosis factor agents in an adolescent with Crohn's disease

BACKGROUND

A 17-year-old white male with Crohn's disease who was receiving maintenance infusions of the anti-tumor necrosis factor (TNF) agent, infliximab, presented with a new-onset psoriasiform skin rash. The rash was not responsive to topical or oral corticosteroids and worsened after infliximab infusions and after subsequent administration of a second anti-TNF drug, adalimumab.

INVESTIGATIONS

Full medical history and physical examination, including assessment of the morphology of rash and the temporal correlation with administration of anti-TNF agents.

DIAGNOSIS

Anti-TNF-agent induced psoriasiform skin rash.

MANAGEMENT

Discontinuation of anti-TNF therapy. The patient opted to have his gastrointestinal symptoms treated with oral mesalazine and metronidazole.

Frequency-velocity mismatch: a fundamental abnormality in parkinsonian gait

Gait dysfunction and falling are major sources of disability for patients with advanced Parkinson's disease (PD). It is presently thought that the fundamental defect is an inability to generate normal stride length. Our data suggest, however, that the basic problem in PD gait is an impaired ability to match step frequency to walking velocity. In this study, foot movements of PD and normal subjects were monitored with an OPTOTRAK motion-detection system while they walked on a treadmill at different velocities. PD subjects were also paced with auditory stimuli at different frequencies. PD gait was characterized by step frequencies that were faster and stride lengths that were shorter than those of normal controls. At low walking velocities, PD stepping had a reduced or absent terminal toe lift, which truncated swing phases, producing shortened steps. Auditory pacing was not able to normalize step frequency at these lower velocities. Peak forward toe velocities increased with walking velocity and PD subjects could initiate appropriate foot dynamics during initial phases of the swing. They could not control the foot appropriately in terminal phases, however. Increased treadmill velocity, which matched the natural PD step frequency, generated a second toe lift, normalizing step size. Levodopa increased the bandwidth of step frequencies, but was not as effective as increases in walking velocity in normalizing gait. We postulate that the inability to control step frequency and adjust swing phase dynamics to slower walking velocities are major causes for the gait impairment in PD.

Cyclin D1 Is a Direct Target of JAG-Mediated Notch Signaling in Breast Cancer

We have previously demonstrated that expression of the Notch ligand, JAG1 is associated with the basal breast cancer phenotype and disease recurrence. Herein we report on a genomics approach to elucidate mechanisms downstream of JAG1 that promote breast cancer growth. In a survey of 46 breast cancer cell lines we found that triple negative (TN; basal and mesenchymal ER-, PR- and Her2-negative) lines express JAG1 at significantly higher levels than do HER2+ or luminal (ER+) Her2- cell lines. The TN breast cancer cell lines HCC1143 and MDA MB231, which express JAG1 and demonstrate growth inhibition with RNA interference-induced down-regulation of JAG1, were selected for further study. We used microarray profiling of tumor cells transfected with JAG1 siRNA to identify JAG1-regulated genes. Differentially expressed genes (p ≤ 0.005; fold change ≥ 1.5) were identified for further study. Among the JAG1-regulated genes identified, cyclin D1 was found to be a direct target of NOTCH1 and NOTCH3. We show that JAG1 down-regulation results in reduced cyclin D1 expression, reduced direct binding of Notch to the cyclin D1 promoter, and inhibition of cell cycle progression through the cyclin D1-dependant G1/S check-point. Furthermore, we show that cyclin D1 and JAG1 expression correlate in basal breast cancer expression data sets. These data suggest a model whereby JAG1 promotes cyclin D1-mediated proliferation of TN breast cancer cells.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2150.

Dependence of the roll angular vestibuloocular reflex (aVOR) on gravity

Little is known about the dependence of the roll angular vestibuloocular reflex (aVOR) on gravity or its gravity-dependent adaptive properties. To study gravity-dependent characteristics of the roll aVOR, monkeys were oscillated about a naso-occipital axis in darkness while upright or tilted. Roll aVOR gains were largest in the upright position and decreased by 7-15% as animals were tilted from the upright. Thus the unadapted roll aVOR gain has substantial gravitational dependence. Roll gains were also decreased or increased by 0.25 Hz, in- or out-of-phase rotation of the head and the visual surround while animals were prone, supine, upright, or in side-down positions. Gain changes, determined as a function of head tilt, were fit with a sinusoid; the amplitudes represented the amount of the gravity-dependent gain change, and the bias, the gravity-independent gain change. Gravity-dependent gain changes were absent or substantially smaller in roll (approximately 5%) than in yaw (25%) or pitch (17%), whereas gravity-independent gain changes were similar for roll, pitch, and yaw (approximately 20%). Thus the high-frequency roll aVOR gain has an inherent dependence on head orientation re gravity in the unadapted state, which is different from the yaw/pitch aVORs. This inherent gravitational dependence may explain why the adaptive circuits are not active when the head is tilted re gravity during roll aVOR adaptation. These behavioral differences support the idea that there is a fundamental difference in the central organization of canal-otolith convergence of the roll and yaw/pitch aVORs.

Primary cutaneous CD30 positive anaplastic large cell lymphoma in an adolescent

We present a case of a 14-year-old boy with a large ulcerated plaque on the scalp for 6 months, who was found to have primary cutaneous CD30-positive, anaplastic kinase-negative, anaplastic large cell lymphoma with post-auricular lymphadenopathy. MRI, bone marrow biopsy, and laboratory data demonstrated no other systemic involvement. He was treated with radiation and low-dose oral methotrexate, with improvement of the lesion and lymphadenopathy. Very few cases of primary cutaneous CD30-positive anaplastic large cell lymphoma in the pediatric population have been reported, and our case represents one of the first pediatric patients with local lymph node involvement.

Vascular risk factors, HIV serostatus, and cognitive dysfunction in gay and bisexual men

BACKGROUND

The purpose of this study was to evaluate the relationship between cognitive performance, risk factors for cardiovascular and cerebrovascular disease (CVD), and HIV infection in the era of highly active antiretroviral therapy.

METHODS

We evaluated the cognitive functions of men enrolled in the cardiovascular disease substudy of the Multicenter AIDS Cohort Study who were aged > or =40 years, with no self-reported history of heart disease or cerebrovascular disease. Results from comprehensive neuropsychological evaluations were used to construct composite scores of psychomotor speed and memory performance. Subclinical CVD was assessed by measuring coronary artery calcium and carotid artery intima-media thickness (IMT), as well as laboratory measures, including total cholesterol, fasting glucose, glycosylated hemoglobin, glomerular filtration rate (estimated), and standardized blood pressure and heart rate measures.

RESULTS

After accounting for education, depression, and race, carotid IMT and glomerular filtration rate were significantly associated with psychomotor speed, whereas IMT was associated with memory test performance. HIV serostatus was not significantly associated with poorer cognitive test performance. However, among the HIV-infected individuals, the presence of detectable HIV RNA in plasma was linked to lower memory performance.

CONCLUSIONS

These findings suggest that HIV infection may not be the most important predictor of cognitive performance among older gay and bisexual men in the post-highly active antiretroviral therapy era, at least among those with access to medical care and to appropriate medications. Medical factors associated with normal aging are significantly associated with performance on neuropsychological tests, and good clinical management of these factors both in HIV-infected individuals and those at risk for infection may have beneficial effects in the short term and could reduce the risk of subsequent cognitive decline.

Adaptation of orientation of central otolith-only neurons

Otolith-only neurons were recorded extracellularly in the vestibular nuclei before and after cynomolgus monkeys were held on-side for up to 3 hr. The aim was to determine whether the polarization vectors of these neurons reorient toward the spatial vertical as do canal-otolith convergent neurons. Otolith input was characterized by tilting the animal 30 degrees from the upright position while positioning the head in different directions in yaw. This determined the response vector orientation (RVO), that is, the projection of the otolith polarization vector onto the head horizontal plane. Changes in the RVO of otolith-only neurons ranged from 2 degrees -16 degrees , which was on average considerably less than the changes previously noted in canal-otolith convergent vestibulo-only (VO) and vestibular plus saccade (VPS) neurons, which ranged up to 109 degrees. Some of the otolith-only neurons had marked sensitivity changes. These findings suggest that otolith-only neurons tend to maintain a head-fixed orientation during prolonged head tilts relative to gravity. In contrast, canal-convergent VO and VPS neurons optimize their response vector orientation to gravity when the head is oriented for prolonged periods.

Effect of canal plugging on quadrupedal locomotion in monkey

The vestibular system plays an important role in controling gait, but where in the labyrinths relevant activity arises is largely unknown. After the semicircular canals are plugged, low frequency (0.01-2 Hz) components of the angular vestibulo-ocular reflex (aVOR) and angular vestibulo-collic reflex (aVCR) are lost, but high frequency (3-20 Hz) components remain. We determined how loss of low frequency canal afference affects limb and head movements during quadrupedal locomotion. Head, body, and limb movements were recorded in three dimensions (3-D) in a cynomolgus monkey with a motion detection system, while the animal walked on a treadmill. All six canals were plugged, reducing the canal time constants from approximately 4.0 sec to approximately 0.07 sec. Major changes in the control of the limbs occurred after surgery. Fore and hind limbs were held farther from the body, producing a broad-based gait. Swing-phase trajectories were inaccurate, and control of medial-lateral limb movement was erratic. These changes in gait were present immediately after surgery, as well as 15 months later, when the animal had essentially recovered. Thus, control of the limbs in the horizontal plane was defective after loss of the low-frequency semicircular canal input and never recovered. Cycle-averaged pitch and roll head rotations, and 3-D head translations were also significantly larger and more erratic after than before surgery. Head rotations in yaw could not be quantified due to intrusion of voluntary head turns. These findings indicate that the semicircular canals provide critical low frequency information to maximize the accuracy of stepping and stabilize the head during normal quadrupedal locomotion.

Modification of the cervico-ocular reflex by canal plugging

The cervico-ocular reflex (COR) has a low gain in normal animals. In this study, we determined whether COR gain increases were specific to the low/midband frequency range, which is the range over which the angular vestibulo-ocular reflex (aVOR) is compromised by plugging. The gain and phase of the yaw and pitch COR and aVOR were compared in normal monkeys and those with all six semicircular canals or only the lateral canal plugged. During experiments animals sat with the body fixed to a chair and the head fixed in space. The body was oscillated about body-yaw and body-pitch axes over a frequency range of 0.05-6 Hz, with amplitude <10 degrees. For normal animals, both yaw and pitch eye velocities were compensatory to the relative velocity of the head with respect to the body. The gains were 0.1-0.2 at frequencies below 1 Hz and decreased to zero as stimulus frequency increased above 1 Hz. Canal-plugged animals had COR gains close to 1.0 at low frequencies, decreasing to approximately 0.6 at 0.5 Hz and to 0.2 for stimulus frequencies above 3 Hz. The phase of eye velocity was 180 degrees relative to head-re-body velocity at frequencies below 0.5 Hz and shifted toward 270 degrees as frequencies were increased to 4 Hz. This study demonstrates that adaptation of COR gain is tuned to a frequency range at which the aVOR is compromised by the canal plugging.

Effects of the linear vestibulo-ocular reflex on accommodative vergence eye movements

The aim of the study was to determine whether accommodation to the relative motion of a target along the visual axis of one eye during fore-aft movement of the head could induce accurate vergence over a wide range of viewing distances and frequencies of oscillation, despite lack of vision in the second eye. This was compared to the vergence when both eyes viewed the target. Two rhesus monkeys were trained to fixate a visual target located 216-336 mm in front and along the visual axis of one eye, while being sinusoidally translated in the fore-aft direction. There was no movement of the seeing eye while the other eye converged, regardless of whether there was vision in the converged eye. Gain and phase of the convergence were determined based on the ratio of actual versus expected eye position if the target was accurately fixated. During translation at frequencies from 0.05 to 2 Hz, the eye converged on the target with an eye position gain of approximately 1, and a phase close to zero. When vision was occluded in the converging eye, gains of convergence were 0.6-0.8 Hz up to 2 Hz, and the phases remained close to zero. At low frequencies of fore-aft movement, when the acceleration was negligible, convergence was driven by accommodation in the seeing eye. At higher frequencies, vergence could also be driven by the linear vestibulo-ocular reflex (lVOR). Thus, vision in one nonmoving eye and the lVOR combine to generate convergence over a wide range of frequencies and viewing distances.

Adaptation of the angular vestibulo-ocular reflex to head movements in rotating frames of reference

Head movements in a rotating frame of reference are commonly encountered, but their long term effects on the angular vestibulo-ocular reflex (aVOR) are not well understood. To study this, monkeys were oscillated about a naso-occipital (roll) axis for several hours while rotating about a spatial vertical axis (roll-while-rotating, RWR). This induced oscillations in roll and pitch eye velocity and continuous horizontal (yaw) nystagmus. For several hours thereafter, simple roll in darkness induced horizontal nystagmus and pitch and roll oscillations. The rising and falling time constants of the horizontal velocity indicated that the nystagmus arose in velocity storage. The continuous nystagmus was correlated with a phase shift of vertical eye velocity from 90 degrees to 0 degrees re head position. As the phases reverted toward pre-adaptive values, the horizontal velocity declined. Similar yaw nystagmus and pitch and roll velocities were produced by oscillation in roll after adaptation with roll and horizontal optokinetic nystagmus (OKN), but not after adaptation with pitch-while-rotating (PWR). Findings were explained by a model that shifted the roll orientation vector of velocity storage toward the pitch axis during adaptation with RWR and Roll & OKN. This shift produced modulation in vertical eye velocity in the post adaptive state, which was approximately in phase with roll head position, generating horizontal nystagmus. Similar orientation changes to prolonged exposure to complex motion environments may be responsible for producing post-stimulus motion sickness and/or mal de debarquement.

Sensitive biomarker of polycyclic aromatic hydrocarbons (PAHs): urinary 1-hydroxyprene glucuronide in relation to smoking and low ambient levels of exposure

The study was conducted in a Chinese population with occupational or environmental exposures to polycyclic aromatic hydrocarbons (PAHs). A total of 106 subjects were recruited from coke-oven workers (workers), residents in a metropolitan area (residents) and suburban gardeners (gardeners). All subjects were monitored twice for their personal exposures to PAHs. The biological samples were collected for measurements of 1-hydroxypyrene (1-OHP) and cotinine in urine. The geometric means of personal exposure levels of pyrene, benz(a)anthracene (BaA) and benzo(a)pyrene (BaP) in workers were 1.470, 0.978 and 0.805 microg m-3, respectively. The corresponding levels in residents were 0.050, 0.034 and 0.025 microg m-3; and those in gardeners were 0.011, 0.020 and 0.008 microg m-3, respectively. The conjugate of 1-OHP with glucuronide (1-OHP-G) is the predominant form of pyrene metabolite in urine and it showed strong associations with exposures not only to pyrene, but also to BaA, BaP and total PAHs. Most importantly, a significant difference in 1-OHP-G was even detected between the subgroups with exposures to BaP at < 0.010 and > 0.010 but < 0.020 microg m-3, suggesting that 1-OHP-G is a good marker that can be used for the risk assessment of BaP exposure at levels currently encountered in ambient air. Furthermore, multiple regression analyses of 1-OHP-G on PAHs exposure indicated that cigarette smoke was a major confounding factor and should be considered and adjusted for while using 1-OHP to estimate PAHs exposure.

Head stabilization by vestibulocollic reflexes during quadrupedal locomotion in monkey

Little is known about the three-dimensional characteristics of vestibulocollic reflexes during natural locomotion. Here we determined how well head stability is maintained by the angular and linear vestibulocollic reflexes (aVCR, lVCR) during quadrupedal locomotion in rhesus and cynomolgus monkeys. Animals walked on a treadmill at velocities of 0.4-1.25 m/s. Head rotations were represented by Euler angles (Fick convention). The head oscillated in yaw and roll at stride frequencies (approximately 1-2 Hz) and pitched at step frequencies (approximately 2-4 Hz). Head angular accelerations (100-2,500 degrees/s2) were sufficient to have excited the aVOR to stabilize gaze. Pitch and roll head movements were <7 degrees , peak to peak, and the amplitude was unrelated to stride frequency. Yaw movements were larger due to spontaneous voluntary head shifts and were smaller at higher walking velocities. Head translations were small (< or =4 cm). Cynomolgus monkeys positioned their heads more forward in pitch than the rhesus monkeys. None of the animals maintained a forward head fixation point, indicating that the lVCR contributed little to compensatory head movements in these experiments. Significantly, aVCR gains in roll and pitch were close to unity and phases were approximately 180 degrees over the full frequency range of natural walking, which is in contrast to previous findings using anesthesia or passive trunk rotation with body restraint. We conclude that the behavioral state associated with active body motion is necessary to maintain head stability in pitch and roll over the full range of stride/step frequencies encountered during walking.

Adaptation of orientation vectors of otolith-related central vestibular neurons to gravity

Behavioral experiments indicate that central pathways that process otolith-ocular and perceptual information have adaptive capabilities. Because polarization vectors of otolith afferents are directly related to the electro-mechanical properties of the hair cell bundle, it is unlikely that they change their direction of excitation. This indicates that the adaptation must take place in central pathways. Here we demonstrate for the first time that otolith polarization vectors of canal-otolith convergent neurons in the vestibular nuclei have adaptive capability. A total of 10 vestibular-only and vestibular-plus-saccade neurons were recorded extracellularly in two monkeys before and after they were in side-down positions for 2 h. The spatial characteristics of the otolith input were determined from the response vector orientation (RVO), which is the projection of the otolith polarization vector, onto the head horizontal plane. The RVOs had no specific orientation before animals were in side-down positions but moved toward the gravitational axis after the animals were tilted for extended periods. Vector reorientations varied from 0 to 109 degrees and were linearly related to the original deviation of the RVOs from gravity in the position of adaptation. Such reorientation of central polarization vectors could provide the basis for changes in perception and eye movements related to prolonged head tilts relative to gravity or in microgravity.

A model-based approach for assessing parkinsonian gait and effects of levodopa and deep brain stimulation

Gait and balance disturbances are amongst the most disabling features of Parkinson's disease (PD), and are not adequately controlled with currently available medical and surgical therapies. Development of objective quantitative measures of these abnormalities would greatly help in the assessment and the development of therapeutic interventions. Recently, we developed a methodology, using dynamical system theory, for testing gait with a state-of-the-art motion-detection system (OPTOTRAK 3020, Northern Digital, Inc.). We also developed a model of the dynamics of the foot that predicts the stance and swing phase dynamics of normal walking. In the present study, we determined whether model parameters were altered in subjects with PD when they were tested on/off levodopa (LD) and on/off deep brain stimulation (DBS) in a 2 x 2 matrix.

Baclofen, motion sickness susceptibility and the neural basis for velocity storage

Reduction of the dominant time constant (T(VOR)) of the angular vestibulo-ocular reflex (aVOR) by habituation is associated with a decrease in motion sickness susceptibility. Baclofen, a GABA(b) agonist, reduces the time constant of the velocity storage integrator in the aVOR in a dose-dependent manner. The high frequency aVOR gain is unaltered by baclofen. Here we demonstrate that the reduction in T(VOR) produced by oral administration of 20 mg of baclofen causes a significant reduction in motion sickness susceptibility, tested with roll while rotating (RWR). These data show that motion sickness susceptibility can be pharmacologically manipulated with a GABA(b) agonist and support our conclusion that motion sickness is generated through velocity storage. We also show how baclofen acts on velocity storage at the neural level. A vestibular-plus-saccade (VPS) neuron was recorded in the rostral medial vestibular nucleus (rMVN) of a cynomolgus monkey, an area where we postulate that velocity storage is generated. The cell had a time constant during steps of velocity that was close to that of the T(VOR). After parenteral administration of baclofen, there was a similar decrease in the time constants of the VPS neuron and the T(VOR). This is the first demonstration of the concurrence of unit and aVOR time constants before and after baclofen. The data support the hypothesis that the velocity storage integrator is generated through activity of vestibular-only (VO) and VPS neurons in rMVN and suggest that GABA(b) synapses on VO and VPS neurons are likely to be involved in the baclofen-induced reduction in motion sickness susceptibility.

The systematic collection and characterisation of herbaceous forage species for recharge and discharge environments in southern Australia

Australian temperate pasture Genetic Resource Centres (GRCs) co-ordinated a major program to introduce and screen herbaceous forage species. This program aims to expand the environments where such species could reduce recharge and manage discharge for the control of dryland salinity in southern Australia. The sustainability of agriculture, in Australia especially, depends on continued access to new germplasm to enable plant breeders to continue crop and forage improvement. The GRCs supported the selection and identification of promising new legume, grass and herb species as part of a national pasture evaluation program. In total, 671 species and 21 non-species-specific genera were identified as having potential to increase water use profitability of recharge lands and to improve the productivity of saline lands across a diverse range of agricultural environments in southern Australia. Through a series of activities, 201 of these species, representing legumes, herbs and grasses were identified as promising. These were then disseminated for evaluation in a range of environments across southern Australia. The progress of selected species was monitored and germplasm of the most promising 11 species and three leguminous genera was targeted for intensive acquisition and characterisation as the basis for selection and breeding. In addition to the identification and dissemination of promising species of immediate potential, a comprehensive collection of 544 native and exotic, wild and cultivated pasture species was conserved and is now available to service future plant improvement programs.