Kinematic gait characteristics of straight line walk in clinically sound dairy cows

The aim of this study is to describe the kinematic gait characteristics of straight line walk in clinically sound dairy cows using body mounted Inertial Measurement Units (IMUs) at multiple anatomical locations. The temporal parameters used are speed and non-speed normalized stance duration, bipedal and tripedal support durations, maximal protraction and retraction angles of the distal limbs and vertical displacement curves of the upper body. Gait analysis was performed by letting 17 dairy cows walk in a straight line at their own chosen pace while equipped with IMU sensors on tubera sacrale, left and right tuber coxae (LTC and RTC), back, withers, head, neck and all four lower limbs. Data intervals with stride by stride regularity were selected based on video data. For temporal parameters, the median was calculated and 95% confidence intervals (CI) were estimated based on linear mixed model (LMM) analysis, while for limb and vertical displacement curves, the median and most typical curves were calculated. The temporal parameters and distal limb angles showed consistent results with low variance and LMM analysis showed non-overlapping CI for all temporal parameters. The distal limb angle curves showed a larger and steeper retraction angle range for the distal front limbs compared with the hind limbs. The vertical displacement curves of the sacrum, withers, LTC and RTC showed a consistent sinusoidal pattern while the head, back and collar curves were less consistent and showed more variation between and within cows. This kinematic description might allow to objectively differentiate between normal and lame gait in the future and determine the best anatomical location for sensor attachment for lameness detection purposes.

Functional or not functional; that's the question: Can we predict the diagnosis functional movement disorder based on associated features?

Background and purpose

Functional movement disorders (FMDs) pose a diagnostic challenge for clinicians. Over the years several associated features have been shown to be suggestive for FMDs. Which features mentioned in the literature are discriminative between FMDs and non‐FMDs were examined in a large cohort. In addition, a preliminary prediction model distinguishing these disorders was developed based on differentiating features.

Method

Medical records of all consecutive patients who visited our hyperkinetic outpatient clinic from 2012 to 2019 were retrospectively reviewed and 12 associated features in FMDs versus non‐FMDs were compared. An independent t test for age of onset and Pearson chi‐squared analyses for all categorical variables were performed. Multivariate logistic regression analysis was performed to develop a preliminary predictive model for FMDs.

Results

A total of 874 patients were eligible for inclusion, of whom 320 had an FMD and 554 a non‐FMD. Differentiating features between these groups were age of onset, sex, psychiatric history, family history, more than one motor phenotype, pain, fatigue, abrupt onset, waxing and waning over long term, and fluctuations during the day. Based on these a preliminary predictive model was computed with a discriminative value of 91%.

Discussion

Ten associated features are shown to be not only suggestive but also discriminative between hyperkinetic FMDs and non‐FMDs. Clinicians can use these features to identify patients suspected for FMDs and can subsequently alert them to test for positive symptoms at examination. Although a first preliminary model has good predictive accuracy, further validation should be performed prospectively in a multi‐center study.

Correction: Automatic detection of break-over phase onset in horses using hoof-mounted inertial measurement unit sensors

[This corrects the article DOI: 10.1371/journal.pone.0233649.].

Automatic hoof-on and -off detection in horses using hoof-mounted inertial measurement unit sensors

For gait classification, hoof-on and hoof-off events are fundamental locomotion characteristics of interest. These events can be measured with inertial measurement units (IMUs) which measure the acceleration and angular velocity in three directions. The aim of this study was to present two algorithms for automatic detection of hoof-events from the acceleration and angular velocity signals measured by hoof-mounted IMUs in walk and trot on a hard surface. Seven Warmblood horses were equipped with two wireless IMUs, which were attached to the lateral wall of the right front (RF) and hind (RH) hooves. Horses were walked and trotted on a lead over a force plate for internal validation. The agreement between the algorithms for the acceleration and angular velocity signals with the force plate was evaluated by Bland Altman analysis and linear mixed model analysis. These analyses were performed for both hoof-on and hoof-off detection and for both algorithms separately. For the hoof-on detection, the angular velocity algorithm was the most accurate with an accuracy between 2.39 and 12.22 ms and a precision of around 13.80 ms, depending on gait and hoof. For hoof-off detection, the acceleration algorithm was the most accurate with an accuracy of 3.20 ms and precision of 6.39 ms, independent of gait and hoof. These algorithms look highly promising for gait classification purposes although the applicability of these algorithms should be investigated under different circumstances, such as different surfaces and different hoof trimming conditions.

Automatic detection of break-over phase onset in horses using hoof-mounted inertial measurement unit sensors

A prolonged break-over phase might be an indication of a variety of musculoskeletal disorders and can be measured with optical motion capture (OMC) systems, inertial measurement units (IMUs) and force plates. The aim of this study was to present two algorithms for automatic detection of the break-over phase onset from the acceleration and angular velocity signals measured by hoof-mounted IMUs in walk and trot on a hard surface. The performance of these algorithms was evaluated by internal validation with an OMC system and a force plate separately. Seven Warmblood horses were equipped with two wireless IMUs which were attached to the lateral wall of the right front (RF) and hind (RH) hooves. Horses were walked and trotted over a force plate for internal validation while simultaneously the 3D position of three reflective markers, attached to lateral heel, lateral toe and lateral coronet of each hoof, were measured by six infrared cameras of an OMC system. The performance of the algorithms was evaluated by linear mixed model analysis. The acceleration algorithm was the most accurate with an accuracy between -9 and 23 ms and a precision around 24 ms (against OMC system), and an accuracy between -37 and 20 ms and a precision around 29 ms (against force plate), depending on gait and hoof. This algorithm seems promising for quantification of the break-over phase onset although the applicability for clinical purposes, such as lameness detection and evaluation of trimming and shoeing techniques, should be investigated more in-depth.

Treatable inherited rare movement disorders

There are many rare movement disorders, and new ones are described every year. Because they are not well recognized, they often go undiagnosed for long periods of time. However, early diagnosis is becoming increasingly important. Rapid advances in our understanding of the biological mechanisms responsible for many rare disorders have enabled the development of specific treatments for some of them. Well-known historical examples include Wilson disease and dopa-responsive dystonia, for which specific and highly effective treatments have life-altering effects. In recent years, similarly specific and effective treatments have been developed for more than 30 rare inherited movement disorders. These treatments include specific medications, dietary changes, avoidance or management of certain triggers, enzyme replacement therapy, and others. This list of treatable rare movement disorders is likely to grow during the next few years because a number of additional promising treatments are actively being developed or evaluated in clinical trials. © 2017 International Parkinson and Movement Disorder Society.

Physical therapy aimed at self-management versus usual care physical therapy after hip arthroscopy for femoroacetabular impingement: study protocol for a randomized controlled trial

Background

Femoroacetabular impingement has been recognized as a common cause of hip pain and dysfunction, especially in athletes. Femoroacetabular impingement can now be better treated by hip arthroscopy but it is unclear what postoperative rehabilitation of hip arthroscopy should look like. Several rehabilitation protocols have been described, but none presented clinical outcome data. These protocols also differ in frequency, duration and level of supervision. We developed a rehabilitation protocol with supervised physical therapy which showed good clinical results and is considered usual care in our treatment center. However, it is unknown whether, due to the relatively young age and low complication rate of hip arthroscopy patients, rehabilitation based on self-management might lead to similar results. The aims of this pilot study are (1) to determine feasibility and acceptability of the self-management intervention, (2) to obtain a preliminary estimate of the difference in effect between physical therapy aimed at self-management versus usual care physical therapy in patients who undergo hip arthroscopy for femoroacetabular impingement.

Methods/Design

Thirty participants (aged 18–50 years) scheduled for hip arthroscopy will be included and randomized (after surgery) to either self-management or usual care physical therapy in this assessor-blinded randomized controlled trial. After surgery, the self-management group will perform a home-based exercise program three times a week and will receive physical therapy treatment once every 2 weeks for 14 weeks. The usual care group will receive physical therapy treatment twice a week for 14 weeks and will perform an additional home-based exercise program once a week. Assessment will occur preoperatively and at 6, 14, 26 and 52 weeks after surgery. Primary outcomes are feasibility, acceptability and preliminary effectiveness. Feasibility and acceptability will be determined by the willingness to enroll, recruitment rate, adherence to treatment, patient satisfaction, drop-out rate and adverse events. Preliminary effectiveness will be determined using the following outcomes: the International Hip Outcome Tool 33 and hip functional performance as measured with the Single Leg Squat Test 14 weeks after surgery.

Discussion

The results of this study will be used to help decide on the need, feasibility and acceptability of a large-scale randomized controlled trial.

Trial registration

This protocol was registered with the Dutch Trial Registry (NTR5168) on 8 May 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1222-7) contains supplementary material, which is available to authorized users.

Hip joint pathology: relationship between patient history, physical tests, and arthroscopy findings in clinical practice

The purpose of this retrospective cohort study was to (a) describe the clinical presentation of femoroacetabular impingement (FAI) and hip labral pathology; (b) describe the accuracy of patient history and physical tests for FAI and labral pathology as confirmed by hip arthroscopy. Patients (18-65 years) were included if they were referred to a physical therapist to gather pre-operative data and were then diagnosed during arthroscopy. Results of pre-operative patient history and physical tests were collected and compared to arthroscopy. Data of 77 active patients (mean age: 37 years) were included. Groin as main location of pain, the Anterior Impingement test (AIT), Flexion-Abduction-External Rotation (FABER) test, and Fitzgerald test had a high sensitivity (range 0.72-0.91). Sensitivity increased when combining these tests (0.97) as either groin as main location of pain and a positive FABER test or a positive AIT and a positive FABER test were the shortest most sensitive combinations. The results of this study point out that in clinical practice absence of groin as main location of pain combined with a negative FABER test or the combination of a negative AIT and a negative FABER test are suggested to rule out the diagnosis of symptomatic FAI and/or labral pathology.

Three Cases of Palatal Tics and Gilles De La Tourette Syndrome

Five patients with palatal tics and Gilles de la Tourette syndrome have been previously reported. Little is known about the characteristics of palatal tics given that there are so few reports. On one hand, palatal tics may be rare. Alternatively, they may be less well recognized than repetitive eye blinking or sniffing, which are both obvious and, therefore, more often reported. We describe 3 patients with palatal tics and Gilles de la Tourette syndrome. We also review the 5 patients reported in the literature and explore whether there are characteristic features among this group of 8 cases. The 8 patients had the following features: (1) Personal history of other multiple motor/vocal tics, (2) the presence of typical Gilles de la Tourette syndrome comorbidities, (3) positive family history of tics and/or Gilles de la Tourette syndrome comorbidities, (4) the presence of audible "ear clicks," (5) younger age at onset (2 years). We suggest that palatal tics are underreported.

Patient-Reported Outcome (PRO) questionnaires for young to middle-aged adults with hip and groin disability: a systematic review of the clinimetric evidence

BACKGROUND/AIM

To recommend Patient-Reported Outcome (PRO) questionnaires to measure hip and groin disability in young-aged to middle-aged adults.

METHODS

A systematic review was performed in June 2014. The methodological quality of the studies included was determined using the COnsensus-based Standards for the selection of health Measurement INstruments list (COSMIN) together with standardised evaluations of measurement properties of each PRO.

RESULTS

Twenty studies were included. Nine different questionnaires for patients with hip disability, and one for hip and groin disability, were identified. Hip And Groin Outcome Score (HAGOS), Hip Outcome Score (HOS), International Hip Outcome Tool-12 (IHOT-12) and IHOT-33 were the most thoroughly investigated PROs and studies including these PROs reported key aspects of the COSMIN checklist. HAGOS and IHOT-12 were based on studies with the least ratings of poor study methodology (23% and 31%, respectively), whereas IHOT-33 and HOS had a somewhat larger distribution (46%). These PROs all contain adequate measurement qualities for content validity (except HOS), test-retest reliability, construct validity, responsiveness and interpretability. No information or poor quality rating on methodological aspects made it impossible to fully evaluate the remaining PROs at present.

CONCLUSIONS

HAGOS, HOS, IHOT-12 and IHOT-33 can be recommended for assessment of young-aged to middle-aged adults with pain related to the hip joint, undergoing non-surgical treatment or hip arthroscopy. At present, HAGOS is the only PRO also aimed for young-aged to middle-aged adults presenting with groin pain and is recommended for use in this population.

TRIAL REGISTRATION NUMBER

CRD42014009995.

High lymph node yield is related to microsatellite instability in colon cancer

BACKGROUND

Lymph node (LN) yield in colon cancer resection specimens is an important indicator of treatment quality and has especially in early-stage patients therapeutic implications. However, underlying disease mechanisms, such as microsatellite instability (MSI), may also influence LN yield, as MSI tumors are known to exhibit more prominent lymphocytic antitumor reactions. The aim of the present study was to investigate the association of LN yield, MSI status, and recurrence rate in colon cancer.

METHODS

Clinicopathological data and tumor samples were collected from 332 stage II and III colon cancer patients. DNA was isolated and PCR-based MSI analysis performed. LN yield was defined as "high" when 10 or more LNs were retrieved and "low" in case of fewer than 10 LNs.

RESULTS

Tumors with high LN yield were significantly associated with the MSI phenotype (high LN yield: 26.3% MSI tumors vs low LN yield: 15.1% MSI tumors; P=.01), mainly in stage III disease. Stage II patients with high LN yield had a lower recurrence rate compared with those with low LN yield. Patients with MSI tumors tended to develop fewer recurrences compared with those with MSS tumors, mainly in stage II disease.

CONCLUSIONS

In the present study, high LN yield was associated with MSI tumors, mainly in stage III patients. Besides adequate surgery and pathology, high LN yield is possibly a feature caused by biologic behavior of MSI tumors.

Standing waves in fiber-optic interferometers

A study is presented giving the response of three types of fiber-optic interferometers by which a standing wave through an object is investigated. The three types are a Sagnac, Mach-Zehnder and Michelson-Morley interferometer. The response of the Mach-Zehnder interferometer is similar to the Sagnac interferometer. However, the Sagnac interferometer is much harder to study because of the fact that one input port and output port coincide. Further, the Mach-Zehnder interferometer has the advantage that the output ports are symmetric, reducing the systematic effects. Examples of standing wave light absorption in several simple objects are given. Attention is drawn to the influence of standing waves in fiber-optic interferometers with weak-absorbing layers incorporated. A method is described for how these can be theoretically analyzed and experimentally measured. Further experiments are needed for a thorough comparison between theory and experiment.

Loss of lamin A/C expression in stage II and III colon cancer is associated with disease recurrence

AIM OF THE STUDY

Loss of the nuclear lamina protein lamin A/C (LMNA) has been observed in several human malignancies. The present study aimed to investigate associations between LMNA expression and clinical outcome in colon cancer patients.

PATIENTS AND METHODS

Clinicopathological data and formalin-fixed paraffin embedded tissues were collected from 370 stage II and III colon cancer patients. Tissue microarrays were constructed, stained for lamin A/C and evaluated microscopically. Microsatellite instability status was determined for 318 tumours.

RESULTS

Low levels of LMNA expression were observed in 17.8% of colon tumours, with disease recurrence occurring in 45.5% of stage II and III colon cancer patients with LMNA-low expressing tumours compared to 29.6% of patients with LMNA-high expressing tumours (p=0.01). For stage II patients, disease recurrence was observed for 35.7% of LMNA-low compared to 20.3% of LMNA-high expressing tumours (p=0.03). Microsatellite stable (MSS) tumours exhibited more frequently low LMNA expression than microsatellite instable (MSI) tumours (21% versus 9.8%; p=0.05). Interestingly, disease recurrence among LMNA-low and LMNA-high expressing MSS tumours varied significantly for stage III patients who had not received adjuvant chemotherapy (100% versus 37.8%; p<0.01) while no such difference was observed for patients who received adjuvant chemotherapy (46.7% versus 46.0%; p=0.96).

CONCLUSION

These data indicate that low expression of LMNA is associated with an increased disease recurrence in stage II and III colon cancer patients, and suggest that these patients in particular may benefit from adjuvant chemotherapy.

Nonsense mutations in CABC1/ADCK3 cause progressive cerebellar ataxia and atrophy

Hereditary ataxias are genetic disorders characterized by uncoordinated gait and often poor coordination of hands, speech, and eye movements. Frequently, atrophy of the cerebellum occurs. Many ataxias are autosomal dominant, but autosomal recessive (AR) disease occurs as well. Homozygosity mapping in a consanguineous family with three affected children with progressive cerebellar ataxia and atrophy revealed a candidate locus on chromosome 1, containing the CABC1/ADCK3 (the chaperone, ABC1 activity of bc1 complex homologue) gene. CABC1/ADCK3 is the homologue of the yeast Coq8 gene, which is involved in the ubiquinone biosynthesis pathway. Mutation analysis of this gene showed a homozygous nonsense mutation (c.1042C>T, p.R348X). Eight additional patients with AR cerebellar ataxia and atrophy were screened for mutations in the CABC1/ADCK3 gene. One patient was compound heterozygous for the same c.1042C>T mutation and a second nonsense mutation (c.1136T>A, p.L379X). Both mutations created a premature stop codon, triggering nonsense mediated mRNA decay as the pathogenic mechanism. We found no evidence of a Dutch founder for the c.1042C>T mutation in AR ataxia. We report here the first nonsense mutations in CABC1 that most likely lead to complete absence of a functional CABC1 protein. Our results indicate that CABC1 is an important candidate for mutation analysis in progressive cerebellar ataxia and atrophy on MRI to identify those patients, who may benefit from CoQ10 treatment.

Profiling of apoptosis genes allows for clinical stratification of primary nodal diffuse large B-cell lymphomas

Intrinsic resistance of lymphoma cells to apoptosis is a probable mechanism causing chemotherapy resistance and eventual fatal outcome in patients with diffuse large B cell lymphomas (DLBCL). We investigated whether microarray expression profiling of apoptosis related genes predicts clinical outcome in 46 patients with primary nodal DLBCL. Unsupervised cluster analysis using genes involved in apoptosis (n = 246) resulted in three separate DLBCL groups partly overlapping with germinal centre B-lymphocytes versus activated B-cells like phenotype. One group with poor clinical outcome was characterised by high expression levels of pro-and anti-apoptotic genes involved in the intrinsic apoptosis pathway. A second group, also with poor clinical outcome, was characterised by high levels of apoptosis inducing cytotoxic effector genes, possibly reflecting a cellular cytotoxic immune response. The third group showing a favourable outcome was characterised by low expression levels of genes characteristic for both other groups. Our results suggest that chemotherapy refractory DLBCL are characterised either by an intense cellular cytotoxic immune response or by constitutive activation of the intrinsic mediated apoptosis pathway with concomitant downstream inhibition of this apoptosis pathway. Consequently, strategies neutralising the function of apoptosis-inhibiting proteins might be effective as alternative treatment modality in part of chemotherapy refractory DLBCL.

Cross-platform array comparative genomic hybridization meta-analysis separates hematopoietic and mesenchymal from epithelial tumors

A series of studies have been published that evaluate the chromosomal copy number changes of different tumor classes using array comparative genomic hybridization (array CGH); however, the chromosomal aberrations that distinguish the different tumor classes have not been fully characterized. Therefore, we performed a meta-analysis of different array CGH data sets in an attempt to classify samples tested across different platforms. As opposed to RNA expression, a common reference is used in dual channel CGH arrays: normal human DNA, theoretically facilitating cross-platform analysis. To this aim, cell line and primary cancer data sets from three different dual channel array CGH platforms obtained by four different institutes were integrated. The cell line data were used to develop preprocessing methods, which performed noise reduction and transformed samples into a common format. The transformed array CGH profiles allowed perfect clustering by cell line, but importantly not by platform or institute. The same preprocessing procedures used for the cell line data were applied to data from 373 primary tumors profiled by array CGH, including controls. Results indicated that there is no apparent feature related to the institute or platform and that array CGH allows for unambiguous cross-platform meta-analysis. Major clusters with common tissue origin were identified. Interestingly, tumors of hematopoietic and mesenchymal origins cluster separately from tumors of epithelial origin. Therefore, it can be concluded that chromosomal aberrations of tumors from hematopoietic and mesenchymal origin versus tumors of epithelial origin are distinct, and these differences can be picked up by meta-analysis of array CGH data. This suggests the possibility of prospectively using combined analysis of diverse copy number data sets for cancer subtype classification.

Reciprocal interactions between oscillatory activities of different frequencies in the subthalamic region of patients with Parkinson's disease

Synchronization of neuronal activity evident in the local field potential (LFP) recorded in the subthalamic region of patients with Parkinson's disease occurs at low frequencies (< 30 Hz) and, in some patients following treatment with levodopa, at high frequencies between 65 and 85 Hz. Here we investigate the functional relationship between these different activities by determining whether spontaneous fluctuations in their strength are correlated across time. To this end, we analysed recordings of LFPs from macroelectrodes inserted in the subthalamic area of 16 patients with Parkinson's disease, after treatment with anti-parkinsonian medication. Time-evolving autospectra of LFPs with significant 65-85 Hz peaks (from 21 sides) were computed and correlations between frequency components determined over time. LFP activity in the 5-32 Hz band was significantly negatively correlated with that in the 65-85 Hz band in data averaged across all 21 sides, as well as in 15 (71%) of the individual records. Negative correlations were relatively selective for interactions between these frequency bands and occurred over time epochs of as little as 40 s. They occurred about 50 min after levodopa and were recorded concurrently with contralateral levodopa-induced dyskinesias in all but four cases. Positive correlations were not seen between activities in the 5-32 Hz and 65-85 Hz bands. The spontaneous negative correlations suggest a reciprocal relationship between population synchrony in the high- and low-frequency ranges, and raise the possibility that spontaneous fluctuations in the balance between these activities may contribute to levodopa-induced dyskinesias.

Different functional loops between cerebral cortex and the subthalmic area in Parkinson's disease

We investigate the extent to which functional circuits coupling cortical and subthalamic activity are multiple and segregated by frequency in untreated Parkinson's disease (PD). To this end, we recorded EEG and local field potentials (LFPs) from macroelectrodes inserted into the subthalamic nucleus area (SA) in nine awake patients following functional neurosurgery for PD. Patients were studied after overnight withdrawal of medication. Coherence between EEG and SA LFPs was apparent in the theta (3-7 Hz), alpha (8-13 Hz), lower beta (14-20 Hz) and upper beta (21-32 Hz) bands, although activity in the alpha and upper beta bands dominated. Theta coherence predominantly involved mesial and lateral areas, alpha and lower beta coherence the mesial and ipsilateral motor areas, and upper beta coherence the midline cortex. SA LFPs led EEG in the theta band. In contrast, EEG led the depth LFP in the lower and upper beta bands. SA LFP activity in the alpha band could either lead or lag EEG. Thus there are several functional sub-loops between the subthalamic area and cerebral cortical motor regions, distinguished by their frequency, cortical topography and temporal relationships. Tuning to distinct frequencies may provide a means of marking and segregating related processing, over and above any anatomical segregation of processing streams.

The relationship between oscillatory activity and motor reaction time in the parkinsonian subthalamic nucleus

Averaging techniques have demonstrated that movement preparatory cues and movement itself are associated with marked reductions in the oscillatory synchrony of local neuronal populations in the area of the human parkinsonian subthalamic nucleus (STN), as indexed by 8-30 Hz local field potential (LFP) activity. In order to examine the detailed nature and strength of the relationship between reductions in oscillatory activity and movement we examined single-trial LFP activity recorded from the STN area of parkinsonian subjects engaged in a choice reaction task. In this task an initial warning cue was either fully predictive or non-predictive of the hand required to make a later motor response. This motor response was elicited by a second go cue to which data were aligned. We observed a significant linear relationship between the onset time of oscillation reduction after go cues and subsequent motor response time across single trials within subjects. Consistent with this observation we also found a positive correlation of power with response time following go cues. In addition, we observed shorter durations of suppression in fully predictive trials where selection of the response could precede go cue presentation. The results are consistent with the hypothesis that reductions in 8-30 Hz population synchrony in the STN area are related to the processing required for motor preparation, particularly response selection.

Behavioural cues are associated with modulations of synchronous oscillations in the human subthalamic nucleus

The speed with which one reacts to an imperative signal depends on the extent to which preceding cues predict that command. When reliable warning cues are available, the processing of the imperative stimulus can be favoured and responses partially pre-prepared, leading to shorter reaction times. Here we seek evidence for involvement of the human basal ganglia in the exploitation of behaviourally relevant predictive cues. To this end, local field potentials (LFPs) were recorded in the region of the subthalamic nuclei of parkinsonian patients during the performance of a pre-cued reaction task in which the cue either predicted or failed to predict the demands of the imperative signal. We demonstrate that LFP activity in the beta frequency band ( approximately 20 Hz) is modulated by the behavioural relevance of the external cue. The findings suggest that, first, the subthalamic nucleus is involved in mediating or facilitating the response advantage derived from predictive cues in humans and, secondly, variations in synchronous neuronal activity in the beta band may contribute to this function in the subthalamic nucleus.

Dopamine-dependent changes in the functional connectivity between basal ganglia and cerebral cortex in humans

We test the hypothesis that interaction between the human basal ganglia and cerebral cortex involves activity in multiple functional circuits characterized by their frequency of oscillation, phase characteristics, dopamine dependency and topography. To this end we took recordings from macroelectrodes (MEs) inserted into the subthalamic nucleus (STN) in eight awake patients following functional neurosurgery for Parkinson's disease. An EEG was also recorded, as were the signals from MEs in the globus pallidus interna (GPi) in two of the cases. Coherence between EEG and ME potentials was apparent in three major frequency bands, 2-10 Hz, 10-30 Hz and 70-85 Hz. These rhythmic activities differed in their cortical topography, although coherence was always strongest over the midline. Coherence between EEG and ME potentials in the 70-85 Hz band was only recorded in patients treated with levodopa. Cortical activity phase led that in the basal ganglia in those oscillatory activities with frequencies <30 Hz. In contrast, STN and GPi phase led cortex in the 70-85 Hz band. The temporal differences in the way in which cortical activity led or lagged behind that in STN/GPi were similar, around 20 ms, regardless of the overall direction of information flow and frequency band. We conclude that the basal ganglia may receive multiple cortical inputs at frequencies <30 Hz and, in the presence of dopaminergic activity, produce a high frequency drive back to the cerebral cortex, in particular the supplementary motor area (SMA).

Serial analysis of gene expression as a tool to assess the human thyroid expression profile and to identify novel thyroidal genes

The assessment of the expression profile of normal human thyroid tissue using serial analysis of gene expression (SAGE) generated a collection of 10,994 sequence transcripts (tags). Each tag represented a messenger RNA transcript, and, in total, 6099 different tags could be distinguished. The presence and abundance of thyroid-specific transcripts showed the overall expression profile to be from a normal thyroid cell. The expression level of several transcripts was confirmed on Northern blot. Seventy percent of tags could not be attributed to a known human gene and, therefore, possibly correspond to novel genes putatively involved in thyroid function. The tag sequence generated by the SAGE technique can be used to further characterize these novel genes. In this way, application of the SAGE technique to thyroid tissue gives insight in the expression profile of a normal thyroid gland and provides the information to characterize novel genes involved in thyroid pathology, such as congenital hypothyroidism and thyroid neoplasia.