Mutation Carriers with Reduced C-Afferent Density Reveal Cortical Dynamics of Pain-Action Relationship during Acute Pain.

The evidence that action shapes perception has become widely accepted, for example, in the domain of vision. However, the manner in which action-relevant factors might influence the neural dynamics of acute pain processing has remained underexplored, particularly the functional roles of anterior insula (AI) and midanterior cingulate cortex (mid-ACC), which are frequently implicated in acute pain. To address this, we examined a unique group of heterozygous carriers of the rare R221W mutation on the nerve growth factor (NGF) gene. R221W carriers show a congenitally reduced density of C-nociceptor afferent nerves in the periphery, but can nonetheless distinguish between painful and nonpainful stimulations. Despite this, carriers display a tendency to underreact to acute pain behaviorally, thus exposing a potential functional gap in the pain-action relationship and allowing closer investigation of how the brain integrates pain and action information. Heterozygous R221W carriers and matched controls performed a functional magnetic resonance imaging (fMRI) task designed to dissociate stimulus type (painful or innocuous) from current behavioral relevance (relevant or irrelevant), by instructing participants to either press or refrain from pressing a button during thermal stimulation. Carriers' subjective pain thresholds did not differ from controls', but the carrier group showed decreased task accuracy. Hemodynamic activation in AI covaried with task performance, revealing a functional role in pain-action integration with increased responses for task-relevant painful stimulation ("signal," requiring button-press execution) over task-irrelevant stimulation ("noise," requiring button-press suppression). As predicted, mid-ACC activation was associated with action execution regardless of pain. Functional connectivity between AI and mid-ACC increased as a function of reported urge to withdraw from the stimulus, suggesting a joint role for these regions in motivated action during pain. The carrier group showed greater activation of primary sensorimotor cortices-but not the AI and mid-ACC regions-during pain and action, suggesting compensatory processing. These findings indicate a critical role for the AI-mid-ACC axis in supporting a flexible, adaptive action selection during pain, alongside the accompanying subjective experience of an urge to escape the pain.

Cumulative evidence for MS as a neural network disconnection syndrome consistent with cognitive impairment mechanisms and the confounding role of fatigue and depression-outlook from the Fourth Nordic MS symposium.

The Fourth Nordic MS symposium served as a platform to present an overview over the rise and impact of cognitive impairment in people with MS, from early stages on, impairing their quality of life. After discussing MS and cognitive impairment symptoms, a review on the pathophysiology underlying cognitive impairment was given, followed by a talk on neuroimaging highlighting cortical reorganization in MS-affected brains. As a conclusion, therapy and treatment options were discussed. The symposium presented several cutting-edge research studies providing or testing working models that appear successful in predicting and explaining cognitive impairment in MS, such as the disconnection syndrome.

Right-hemispheric brain activation correlates to language performance.

Language function in the right-hemispheric homologues of Broca's and Wernicke's areas does not only correlate with left-handedness or pathology, but occurs naturally in right-handed healthy subjects as well. In the current study, two non-invasive methods of assessing language lateralization are correlated with behavioral results in order to link hemispheric dominance to language ability in healthy subjects. Functional magnetic resonance imaging (fMRI) together with a sentence-completion paradigm was used to determine region-specific lateralization indices in the left- and right-sided Broca's and Wernicke's areas, the frontal temporal lobe, the anterior cingulate cortex and the parietal lobe. In addition, dichotic listening results were used to determine overall language lateralization and to strengthen conclusions by correlating with fMRI indices. Results showed that fMRI lateralization in the superior parietal, the posterior temporal, and the anterior cingulate cortices correlated to dichotic listening. A decreased right ear advantage (REA), which indicates less left-hemispheric dominance in language, correlated with higher performance in most administered language tasks, including reading, language ability, fluency, and non-word discrimination. Furthermore, right hemispheric involvement in the posterior temporal lobe and the homologue of Broca's area suggests better performance in behavioral language tasks. This strongly indicates a supportive role of the right-hemispheric counterparts of Broca's and Wernicke's areas in language performance.

fMRI-guided TMS on cortical eye fields: the frontal but not intraparietal eye fields regulate the coupling between visuospatial attention and eye movements.

It is well known that parts of a visual scene are prioritized for visual processing, depending on the current situation. How the CNS moves this focus of attention across the visual image is largely unknown, although there is substantial evidence that preparation of an action is a key factor. Our results support the view that direct corticocortical feedback connections from frontal oculomotor areas to the visual cortex are responsible for the coupling between eye movements and shifts of visuospatial attention. Functional magnetic resonance imaging (fMRI)-guided transcranial magnetic stimulation (TMS) was applied to the frontal eye fields (FEFs) and intraparietal sulcus (IPS). A single pulse was delivered 60, 30, or 0 ms before a discrimination target was presented at, or next to, the target of a saccade in preparation. Results showed that the known enhancement of discrimination performance specific to locations to which eye movements are being prepared was enhanced by early TMS on the FEF contralateral to eye movement direction, whereas TMS on the IPS resulted in a general performance increase. The current findings indicate that the FEF affects selective visual processing within the visual cortex itself through direct feedback projections.

Changes in leucocyte and lymphocyte subsets during tuberculosis treatment; prominence of CD3dimCD56+ natural killer T cells in fast treatment responders.

The immune responses against pulmonary tuberculosis are still poorly defined. This study describes changes in leucocyte and lymphocyte subsets during treatment to find reliable immunological markers for the disease and treatment response. Flow cytometric peripheral blood immune phenotyping, routine haematology and sputum microbiology were performed on 21 HIV-negative adult tuberculosis (TB) patients with positive sputum cultures during therapy in comparison with 14 healthy purified protein derivative (PPD)-positive volunteers. Patients at diagnosis showed high absolute neutrophil and monocyte counts which fell during treatment but low lymphocyte subset counts which increased [except natural killer (NK) and NK T cells]. High counts of a population of CD3(dim)/CD56+ NK T cells at diagnosis correlated significantly with negative sputum culture after 8 weeks of treatment. A multivariate classification technique showed improved correlation when NK cells were taken into account. In conclusion, peripheral blood white cell counts change significantly during treatment and counts at diagnosis, especially CD3(dim)/CD56+ NK T cells, hold promise in predictive models of TB treatment response.

Monoclonal antibody SM047 as an immunohistochemical marker of ovarian adenocarcinoma.

AIMS: This study describes the generation of a monoclonal antibody designated SM047 which binds to an epitope that is displayed by a multivalent antigen associated with the glycocalyx of ovarian adenocarcinoma cells. The study also investigates SM047 staining in adenocarcinomas of diverse sites in order to determine whether the antibody is specific for ovarian adenocarcinoma and of value in the confirmation of an ovarian origin when the site of primary tumour is unknown. METHODS AND RESULTS: SM047, an IgM monoclonal antibody, was the product of hybridoma cells derived from fusion of SP2 myeloma cells with splenocytes of a mouse that had been immunized with a membrane preparation of tumour (ovarian serous cystadenocarcinoma) and boosted with cells from a cell line established from a similar tumour in a different patient. Sixty-two primary ovarian adenocarcinomas (28 serous, 23 mucinous, five endometrioid and six clear cell), 69 adenocarcinomas arising primary at other sites and 10 mesotheliomas were stained with SM047. There was positive membrane staining, which was usually strong and widespread, in 27 of 28 ovarian serous carcinomas and in all ovarian endometrioid and clear cell carcinomas. Most ovarian mucinous tumours were negative or exhibited weak cytoplasmic staining. Staining was variable in the other tumours but there was positive staining of most endometrial, endocervical and pancreatic adenocarcinomas. Most colonic adenocarcinomas were negative or exhibited weak cytoplasmic staining. CONCLUSIONS: SM047 is strongly expressed in most ovarian serous adenocarcinomas and in other female genital tract adenocarcinomas, with the exception of ovarian mucinous tumours. The antibody may be useful in confirming the ovarian origin of an adenocarcinoma when used as part of a larger panel. This is especially so in the distinction between a non-mucinous ovarian adenocarcinoma, which usually exhibits strong membranous staining, and a colonic adenocarcinoma which is usually negative or exhibits weak cytoplasmic staining. These findings need to be confirmed by further study of larger numbers of cases.

Major histocompatibility complex class II invariant chain expression in non-antigen-presenting cells.

In contrast to the generally accepted belief, the major histocompatibility complex (MHC) class II invariant chain (Ii) is commonly expressed intracellularly in cells that do not present exogenous antigens. Such cells include resting peripheral blood T cells and natural killer (NK) cells. In T cells, the Ii is associated with a 77 000 molecular-weight molecule (p77) that has yet to be identified. This molecule is co-precipitated with the anti-Ii monoclonal antibody (mAb) VCD-1, but not with mAb BU-45. This suggests that in the p77-Ii complex, the extracellular epitope of Ii recognized by BU-45 is hidden, whereas the Ii epitope for VCD-1 remains exposed. In antigen-presenting cells (APCs), p77 association with the Ii was minimal, if detectable. The p77-Ii association in non-professional APCs suggests that the Ii may have another, more general, function other than the one accepted in antigen presentation.

Determination of the tyrosine phosphorylation sites in the T cell transmembrane glycoprotein CD5.

Studies of CD5-deficient mice indicate that the transmembrane glycoprotein CD5 negatively regulates antigen receptor-mediated signals in thymocytes, lymph node T cells and B1a cells. CD5 contains four tyrosine residues in its cytoplasmic domain and is phosphorylated on tyrosine residues following antigen receptor ligation. Recently it has been proposed that CD5 function is dependent on the recruitment of the tyrosine phosphatase SHP-1 to tyrosine-phosphorylated CD5 and subsequent dephosphorylation of signaling molecules. In this study we investigated the requirements for, and sites of, CD5 tyrosine phosphorylation. Using a T cell line deficient in the tyrosine kinase p56(lck) and the same cell line reconstituted with this kinase, we show that p56(lck) expression is required for efficient CD5 tyrosine phosphorylation. Using tyrosine-phosphorylated peptides corresponding to CD5 cytoplasmic sequences we also show that the Src homology 2 (SH2) domain of p56(lck) binds prominently to pY429SQP, with 30-fold less affinity to pY463DLQ and not to pY441PAL. A number of murine CD5 Y --> F and deletion mutants were expressed in Jurkat T cells. The Y441F mutant was tyrosine phosphorylated at levels comparable to wild-type, but the Y429F and Y463F mutants were phosphorylated at lower levels. Two deletion mutants, which contain only one tyrosine residue (Y378) located at the interface of the transmembrane and cytoplasmic domains, were not tyrosine phosphorylated, suggesting that Y378 is not readily available for phosphorylation. Taken together these results suggest that both Y429 and Y463 can recruit p56(lck), and that these residues are the only prominent sites for CD5 tyrosine phosphorylation.

Three-dimensional time-resolved optical tomography of a conical breast phantom.

A 32-channel time-resolved imaging device for medical optical tomography has been employed to evaluate a scheme for imaging the human female breast. The fully automated instrument and the reconstruction procedure have been tested on a conical phantom with tissue-equivalent optical properties. The imaging protocol has been designed to obviate compression of the breast and the need for coupling fluids. Images are generated from experimental data with an iterative reconstruction algorithm that employs a three-dimensional (3D) finite-element diffusion-based forward model. Embedded regions with twice the background optical properties are revealed in separate 3D absorption and scattering images of the phantom. The implications for 3D time-resolved optical tomography of the breast are discussed.

Abnormal association between invariant chain and HLA class II alpha and beta chains in chronic lymphocytic leukemia.

We have previously shown that peripheral blood lymphocytes from patients with chronic lymphocytic leukemia (CLL) express increased amounts of the minor p35 form of class II invariant chain (Ii) relative to the major p33 form. In this report we demonstrate in Western blots that in CLL lymphocytes, but not in normal or Epstein-Barr virus-transformed normal lymphocytes, p35 and p33 Ii form sodium dodecyl sulfate (SDS)-resistant complexes with class II alpha and beta chains and that these complexes form an abnormally large proportion of the total class II molecules. Others have shown that stable SDS-resistant alpha-beta complexes are only formed upon binding of exogenous antigenic peptides for presentation at the cell surface. Large amounts of p35 Ii remaining in the endoplasmic reticulum and capable of forming stable complexes with alpha and beta chains could compete with endogenous antigenic peptides for available class II peptide binding sites. The presentation of endogenous tumor antigens would thus be prevented, leading to the escape of the CLL clone from immunological surveillance.

Processing of HLA-class II invariant chain and expression of the p35 form is different in malignant and transformed cells.

A monoclonal antibody VCD-1, directed against the N-terminal intracellular part of the invariant chain (li) was used to show, by immunoprecipitation and Western blotting, the unprocessed and processed forms of li in chronic lymphocytic leukemia (CLL) cells, in Epstein-Barr virus-transformed normal lymphocytes (EBVL), and in cells of the Raji Burkitt's lymphoma cell line. Terminal glycosylation and sulphation of li in the Golgi apparatus was shown in Raji cells and not in EBVL. CLL lymphocytes contain a higher concentration of p35 li than do EBVL or Raji cells.

A monoclonal antibody to an antigen present in cells from a patient with Hodgkin's disease.

A monoclonal antibody-secreting hybridoma cell line, VCD-1, was derived from the fusion of murine myeloma cells with splenocytes from a BALB/c mouse that had been immunised with chronic B-lymphocytic leukaemia cells. The cells came from a patient who had developed the leukaemia approximately 10 years after a course of radiotherapy for nodular sclerosing Hodgkin's disease. The antibody bound to a 30,000-dalton protein that was present in normal and malignant B cells, in monocytes, neutrophils, and interdigitating reticulum cells, and in malignant cells present in Hodgkin's disease lymph nodes. The reactive epitope was not accessible to antibody in viable intact cells; binding to peripheral blood cells could only be seen if the cells were fixed. The antibody recognises a determinant that probably resides on the alpha-chain of HLA class II molecules.