Regional cerebral blood flow throughout the sleep-wake cycle. An H2(15)O PET study

To assess dynamic changes in brain function throughout the sleep-wake cycle, CBF was measured with H2(15)O and PET in 37 normal male volunteers: (i) while awake prior to sleep onset; (ii) during Stage 3-4 sleep, i.e. slow wave sleep (SWS); (iii) during rapid eye movement (REM) sleep; and (iv) upon waking following recovery sleep. Subjects were monitored polysomnographically and PET images were acquired throughout the course of a single night. Stage-specific contrasts were performed using statistical parametric mapping. Data were analysed in repeated measures fashion, examining within-subject differences between stages [pre-sleep wakefulness-SWS (n = 20 subjects); SWS-post-sleep wakefulness (n = 14); SWS-REM sleep (n = 7); pre-sleep wakefulness-REM sleep (n = 8); REM sleep-post-sleep wakefulness (n = 7); pre-sleep wakefulness-post-sleep wakefulness (n = 20)]. State dependent changes in the activity of centrencephalic regions, including the brainstem, thalamus and basal forebrain (profound deactivations during SWS and reactivations during REM sleep) are consistent with the idea that these areas are constituents of brain systems which mediate arousal. Shifts in the level of activity of the striatum suggested that the basal ganglia might be more integrally involved in the orchestration of the sleep-wake cycle than previously thought. State-dependent changes in the activity of limbic and paralimbic areas, including the insula, cingulate and mesial temporal cortices, paralleled those observed in centrencephalic structures during both REM sleep and SWS. A functional dissociation between activity in higher order, heteromodal association cortices in the frontal and parietal lobes and unimodal sensory areas of the occipital and temporal lobes appeared to be characteristic of both SWS and REM sleep. SWS was associated with selective deactivation of the heteromodal association areas, while activity in primary and secondary sensory cortices was preserved. SWS may not, as previously thought, represent a generalized decrease in neuronal activity. On the other hand, REM sleep was characterized by selective activation of certain post-rolandic sensory cortices, while activity in the frontoparietal association cortices remained depressed. REM sleep may be characterized by activation of widespread areas of the brain, including the centrencephalic, paralimbic and unimodal sensory regions, with the specific exclusion of areas which normally participate in the highest order analysis and integration of neural information. Deactivation of the heteromodal association areas (the orbital, dorsolateral prefrontal and inferior parietal cortices) constitutes the single feature common to both non-REM and REM sleep states, and may be a defining characteristic of sleep itself. The stages of sleep could also be distinguished by characteristic differences in the relationships between the basal ganglia, thalamic nuclei and neocortical regions of interest.

Dissociated pattern of activity in visual cortices and their projections during human rapid eye movement sleep

Positron emission tomography was used to measure cerebral activity and to evaluate regional interrelationships within visual cortices and their projections during rapid eye movement (REM) sleep in human subjects. REM sleep was associated with selective activation of extrastriate visual cortices, particularly within the ventral processing stream, and an unexpected attenuation of activity in the primary visual cortex; increases in regional cerebral blood flow in extrastriate areas were significantly correlated with decreases in the striate cortex. Extrastriate activity was also associated with concomitant activation of limbic and paralimbic regions, but with a marked reduction of activity in frontal association areas including lateral orbital and dorsolateral prefrontal cortices. This pattern suggests a model for brain mechanisms subserving REM sleep where visual association cortices and their paralimbic projections may operate as a closed system dissociated from the regions at either end of the visual hierarchy that mediate interactions with the external world.

Altered patterns of cerebral activity during speech and language production in developmental stuttering. An H2(15)O positron emission tomography study

To assess dynamic brain function in adults who had stuttered since childhood, regional cerebral blood flow (rCBF) was measured with H2O and PET during a series of speech and language tasks designed to evoke or attenuate stuttering. Speech samples were acquired simultaneously and quantitatively compared with the PET images. Both hierarchical task contrasts and correlational analyses (rCBF versus weighted measures of dysfluency) were performed. rCBF patterns in stuttering subjects differed markedly during the formulation and expression of language, failing to demonstrate left hemispheric lateralization typically observed in controls; instead, regional responses were either absent, bilateral or lateralized to the right hemisphere. Significant differences were detected between groups when all subjects were fluent-during both language formulation and non-linguistic oral motor tasks-demonstrating that cerebral function may be fundamentally different in persons who stutter, even in the absence of stuttering. Comparison of scans acquired during fluency versus dysfluency-evoking tasks suggested that during the production of stuttered speech, anterior forebrain regions-which play an a role in the regulation of motor function-are disproportionately active in stuttering subjects, while post-rolandic regions-which play a role in perception and decoding of sensory information-are relatively silent. Comparison of scans acquired during these conditions in control subjects, which provide information about the sensorimotor or cognitive features of the language tasks themselves, suggest a mechanism by which fluency-evoking maneuvers might differentially affect activity in these anterior and posterior brain regions and may thus facilitate fluent speech production in individuals who stutter. Both correlational and contrast analyses suggest that right and left hemispheres play distinct and opposing roles in the generation of stuttering symptoms: activation of left hemispheric regions appears to be related to the production of stuttered speech, while activation of right hemispheric regions may represent compensatory processes associated with attenuation of stuttering symptoms.

The neural organization of discourse: an H2 15O-PET study of narrative production in English and American sign language

In order to identify brain regions that play an essential role in the production of discourse, H2 15O-PET scans were acquired during spontaneous generation of autobiographical narratives in English and in American Sign Language in hearing subjects who were native users of both. We compared languages that differ maximally in their mode of expression yet share the same core linguistic properties in order to differentiate the stages of discourse production: differences between the languages should reflect later, modality-dependent stages of phonological encoding and articulation; congruencies are more likely to reveal the anatomy of earlier modality-independent stages of conceptualization and lexical access. Common activations were detected in a widespread array of regions; left hemisphere language areas classically related to speech were also robustly activated during sign production, but the common neural architecture extended beyond the classical language areas and included extrasylvian regions in both right and left hemispheres. Furthermore, posterior perisylvian and basal temporal regions appear to play an integral role in spontaneous self-generated formulation and production of language, even in the absence of exteroceptive stimuli. Results additionally indicate that anterior and posterior areas may play distinct roles in early and late stages of language production, and suggest a novel model for lateralization of cerebral activity during the generation of discourse: progression from the early stages of lexical access to later stages of articulatory-motor encoding may constitute a progression from bilateral to left-lateralized activation. This pattern is not predicted by the standard Wernicke-Geschwind model, and may become apparent when language is produced in an ecologically valid context.

Essential and opposing roles of zebrafish beta-catenins in the formation of dorsal axial structures and neurectoderm

In Xenopus, Wnt signals and their transcriptional effector beta-catenin are required for the development of dorsal axial structures. In zebrafish, previous loss-of-function studies have not identified an essential role for beta-catenin in dorsal axis formation, but the maternal-effect mutation ichabod disrupts beta-catenin accumulation in dorsal nuclei and leads to a reduction of dorsoanterior derivatives. We have identified and characterized a second zebrafish beta-catenin gene, beta-catenin-2, located on a different linkage group from the previously studied beta-catenin-1, but situated close to the ichabod mutation on LG19. Although the ichabod mutation does not functionally alter the beta-catenin-2 reading frame, the level of maternal beta-catenin-2, but not beta-catenin-1, transcript is substantially lower in ichabod, compared with wild-type, embryos. Reduction of beta-catenin-2 function in wild-type embryos by injection of morpholino antisense oligonucleotides (MOs) specific for this gene (MO2) results in the same ventralized phenotypes as seen in ichabod embryos, and administration of MO2 to ichabod embryos increases the extent of ventralization. MOs directed against beta-catenin-1 (MO1), by contrast, had no ventralizing effect on wild-type embryos. beta-catenin-2 is thus specifically required for organizer formation and this function is apparently required maternally, because the ichabod mutation causes a reduction in maternal transcription of the gene and a reduced level of beta-catenin-2 protein in the early embryo. A redundant role of beta-catenins in suppressing formation of neurectoderm is revealed when both beta-catenin genes are inhibited. Using a combination of MO1 and MO2 in wild-type embryos, or by injecting solely MO1 in ichabod embryos, we obtain expression of a wide spectrum of neural markers in apparently appropriate anteroposterior pattern. We propose that the early, dorsal-promoting function of beta-catenin-2 is essential to counteract a later, dorsal- and neurectoderm-repressing function that is shared by both beta-catenin genes.

T cell activation pathways: B7, LFA-3, and ICAM-1 shape unique T cell profiles

Two signals are required for induction of cell proliferation and cytokine production in resting T cells. Occupancy of the T cell receptor by antigen/MHC complexes delivers the first signal to the T cell, while the second signal is provided by interaction with costimulatory ligands on APC. CD2, LFA-1, and CD28 are the major costimulatory and adhesive molecules on T cells and bind to the LFA-3, ICAM-1 and B7 ligands, respectively, on APC. LFA-3 plays a central role for naive and memory T helper cells during the early phase of an immune response. The LFA-3/CD2 pathway initiates strong antigen-independent cell adhesion, substantial expansion of naive T helper cells, and induction of large amounts of IFN-gamma in memory cells. The release of IFN-gamma may upregulate expression of ICAM-1 and B7 on APC and allows multiple adhesion pathways to amplify the immune response. The LFA-1/ICAM-1 pathway stimulates adhesion and cell proliferation more efficiently in memory T helper cells than in naive cells. Further, the results suggest that naive T helper cells express functionally inactive LFA-1 molecules on the cell surface, which may have a physiological role in keeping these cells in a resting state. B7 costimulation superinduces IL-2 production in both naive and memory T helper cells and generates long-lasting cell proliferation. This permits transition from an autocrine to a paracrine immune response. Coexpression of B7/LFA-3 provides an optimal APC function and enables a vigorous T cell response to minute amounts of antigen. AP-1 and NF-kappa B transcription factors are involved in the induction of several cytokine gene promoters and play a central role in the regulation of IL-2 gene transcription. LFA-3 costimulation only moderately enhances AP-1 DNA-binding activity and does not influence the NF-kappa B activity induced by TCR engagement, whereas B7 costimulation induces large amounts of NF-kappa B and AP-1 activity in T helper cells. The costimulatory ligands represent a family of adhesion molecules with considerable redundancy. Interfamily redundancy of LFA-3, B7, and ICAM ligands offers an opportunity to regulate distinct T cell response profiles in various microenvironments at separate time points of an immune response.

Functional neuroanatomy of human vocalization: an H215O PET study

Vocalization in lower animals is associated with a well-described visceromotor call system centered on the mesencephalic periacqueductal grey matter (PAG), which is itself regulated by paramedian cortical structures. To determine the role this phylogenetically older system plays in human phonation, we contrasted voiced and unvoiced speech using positron emission tomography and then evaluated functional connectivity of regions that significantly differentiated these conditions. Vocalization was associated with increased and highly correlated activity within the midline structures--PAG and paramedian cortices--described in lower mammalian species. Concurrent activation and connectivity of neocortical and subcortical motor regions--medial and lateral premotor structures and elements of basal ganglia thalamocortical circuitry--suggest a mechanism by which this system may have come under an increasing degree of voluntary control in humans. Additionally, areas in the temporal lobe and cerebellum were selectively activated during voiced but not unvoiced speech. These regions are functionally coupled to both visceromotor and neocortical motor areas during production of voiced speech, suggesting they may play a central role in self-monitoring and feedback regulation of human phonation.

Implementation of the European health interview survey (EHIS) into the German health update (GEDA)

Background

This methodological paper describes the integration of the ‘European Health Interview Survey wave 2’ (EHIS 2) into the ‘German Health Update’ 2014/2015 (GEDA 2014/2015-EHIS).

Methods

GEDA 2014/2015-EHIS is a cross-sectional health survey. A two-stage stratified cluster sampling approach was used to recruit persons aged 15 years and older with permanent residence in Germany. Two different modes of data collection were used, self-administered web questionnaire and self-administered paper questionnaire. The survey instrument implemented the EHIS 2 modules on health status, health care use, health determinants and social background variables and additional national questions. Data processing was conducted according to the quality and validation rules specified by Eurostat.

Results

In total, 24,824 questionnaires were completed. The response rate was 27.6%. The two-stage cluster sample method seems to have been successful in achieving a sample with high representativeness. The final micro data file was inspected, approved and certified by Eurostat. Access to micro data of the EHIS 2 can be provided by Eurostat via research contract and to the GEDA 2014/2015-EHIS public use file by the Research Data Centre of the Robert Koch Institute. First EHIS 2 results are available at the Eurostat website.

Conclusions

Integrating a multinational health survey into an existing national health monitoring system was a challenge in Germany. The national survey methodology for conducting the survey had to be further developed in order to meet the overarching goal of harmonizing the health information from national statistical offices and public health research institutes across the European Union. The harmonized EHIS 2 data source will profoundly impact international public health research in the near future. The next EHIS wave 3 will be conducted around 2019.

para-Nitroblebbistatin, the non-cytotoxic and photostable myosin II inhibitor

Blebbistatin, the best characterized myosin II-inhibitor, is commonly used to study the biological roles of various myosin II isoforms. Despite its popularity, the use of blebbistatin is greatly hindered by its blue-light sensitivity, resulting in phototoxicity and photoconversion of the molecule. Additionally, blebbistatin has serious cytotoxic side effects even in the absence of irradiation, which may easily lead to the misinterpretation of experimental results since the cytotoxicity-derived phenotype could be attributed to the inhibition of the myosin II function. Here we report the synthesis as well as the in vitro and in vivo characterization of a photostable, C15 nitro derivative of blebbistatin with unaffected myosin II inhibitory properties. Importantly, para-nitroblebbistatin is neither phototoxic nor cytotoxic, as shown by cellular and animal tests; therefore it can serve as an unrestricted and complete replacement of blebbistatin both in vitro and in vivo.

Complex regulation of autophagy in cancer - integrated approaches to discover the networks that hold a double-edged sword

Autophagy, a highly regulated self-degradation process of eukaryotic cells, is a context-dependent tumor-suppressing mechanism that can also promote tumor cell survival upon stress and treatment resistance. Because of this ambiguity, autophagy is considered as a double-edged sword in oncology, making anti-cancer therapeutic approaches highly challenging. In this review, we present how systems-level knowledge on autophagy regulation can help to develop new strategies and efficiently select novel anti-cancer drug targets. We focus on the protein interactors and transcriptional/post-transcriptional regulators of autophagy as the protein and regulatory networks significantly influence the activity of core autophagy proteins during tumor progression. We list several network resources to identify interactors and regulators of autophagy proteins. As in silico analysis of such networks often necessitates experimental validation, we briefly summarize tractable model organisms to examine the role of autophagy in cancer. We also discuss fluorescence techniques for high-throughput monitoring of autophagy in humans. Finally, the challenges of pharmacological modulation of autophagy are reviewed. We suggest network-based concepts to overcome these difficulties. We point out that a context-dependent modulation of autophagy would be favored in anti-cancer therapy, where autophagy is stimulated in normal cells, while inhibited only in stressed cancer cells. To achieve this goal, we introduce the concept of regulo-network drugs targeting specific transcription factors or miRNA families identified with network analysis. The effect of regulo-network drugs propagates indirectly through transcriptional or post-transcriptional regulation of autophagy proteins, and, as a multi-directional intervention tool, they can both activate and inhibit specific proteins in the same time. The future identification and validation of such regulo-network drug targets may serve as novel intervention points, where autophagy can be effectively modulated in cancer therapy.

Autophagy is required for zebrafish caudal fin regeneration

Regeneration is the ability of multicellular organisms to replace damaged tissues and regrow lost body parts. This process relies on cell fate transformation that involves changes in gene expression as well as in the composition of the cytoplasmic compartment, and exhibits a characteristic age-related decline. Here, we present evidence that genetic and pharmacological inhibition of autophagy - a lysosome-mediated self-degradation process of eukaryotic cells, which has been implicated in extensive cellular remodelling and aging - impairs the regeneration of amputated caudal fins in the zebrafish (Danio rerio). Thus, autophagy is required for injury-induced tissue renewal. We further show that upregulation of autophagy in the regeneration zone occurs downstream of mitogen-activated protein kinase/extracellular signal-regulated kinase signalling to protect cells from undergoing apoptosis and enable cytosolic restructuring underlying terminal cell fate determination. This novel cellular function of the autophagic process in regeneration implies that the role of cellular self-digestion in differentiation and tissue patterning is more fundamental than previously thought.

Insight, symptoms and neurocognition in bipolar I patients

BACKGROUND

Level of insight and its relationship to clinical variables and neurocognitive functions was assessed in bipolar I patients.

METHODS

Verbal memory, executive functioning, sustained attention, general intelligence and other neurocognitive functions were compared between 37 chronic in- and outpatients and 31 matched normal controls. Detailed psychiatric interviews were completed to define the level of symptomatology and psychosocial functioning. Insight was assessed by the Scale to Assess Unawareness of Mental Disorder (SUMD).

RESULTS

Seventy percent of the patients were classified as having impaired insight. Prevalence of impaired insight was 47% and 94% in remitted and symptomatic patients, respectively. Symptomatic patients scored significantly below remitted patients on insight and neurocognition. Illness and symptom unawareness were related to overall level of symptoms, measures of memory, conceptual ability and right hand psychomotor speed and accuracy. Misattribution of symptoms and signs was correlated to visuomotor speed and visuospatial performance in addition to affective symptoms and thought disturbance.

CONCLUSIONS

Our findings support the hypothesis that impaired insight and other neurocognitive dysfunctions were present in a large percentage of cases among symptomatic as well as remitted bipolar patients. This may be of clinical relevance and raises important questions about the course and outcome of the illness.

Both autologous bone marrow mononuclear cell and peripheral blood progenitor cell therapies similarly improve ischaemia in patients with diabetic foot in comparison with control treatment

BACKGROUND

The aim of our study was to compare the effect of bone marrow mononuclear cell and peripheral blood progenitor cell therapies in patients with diabetic foot disease and critical limb ischaemia unresponsive to revascularization with conservative therapy.

METHODS

Twenty-eight patients with diabetic foot disease (17 treated by bone marrow cells and 11 by peripheral blood cell) were included into an active group and 22 patients into a control group without cell treatment. Transcutaneous oxygen pressure and rate of major amputation, as the main outcome measures, were compared between bone marrow cells, peripheral blood cell and control groups over 6 months; both cell therapy methods were also compared by the characteristics of cell suspensions. Possible adverse events were evaluated by changes of serum levels of angiogenic cytokines and retinal fundoscopic examination.

RESULTS

The transcutaneous oxygen pressure increased significantly (p < 0.05) compared with baseline in both active groups after 6 months, with no significant differences between bone marrow cells and peripheral blood cell groups; however, no change of transcutaneous oxygen pressure in the control group was observed. The rate of major amputation by 6 months was significantly lower in the active cell therapy group compared with that in the control group (11.1% vs. 50%, p = 0.0032), with no difference between bone marrow cells and peripheral blood cell. A number of injected CD34+ cells and serum levels of angiogenic cytokines after treatment did not significantly differ between bone marrow cells and peripheral blood cell.

CONCLUSIONS

Our study showed a superior benefit of bone marrow cells and peripheral blood cell treatments of critical limb ischaemia in patients with diabetic foot disease when compared with conservative therapy. There was no difference between both cell therapy groups, and no patient demonstrated signs of systemic vasculogenesis.

Randomised clinical trial: a 1-week, double-blind, placebo-controlled study of pancreatin 25 000 Ph. Eur. minimicrospheres (Creon 25000 MMS) for pancreatic exocrine insufficiency after pancreatic surgery, with a 1-year open-label extension

BACKGROUND

Pancreatic exocrine insufficiency (PEI) often occurs following pancreatic surgery.

AIM

To demonstrate the superior efficacy of pancreatin 25 000 minimicrospheres (Creon 25000 MMS; 9-15 capsules/day) over placebo in treating PEI after pancreatic resection.

METHODS

A 1-week, double-blind, randomised, placebo-controlled, parallel-group, multicentre study with a 1-year, open-label extension (OLE). Subjects ≥18 years old with PEI after pancreatic resection, defined as baseline coefficient of fat absorption (CFA) <80%, were randomised to oral pancreatin or placebo (9-15 capsules/day: 3 with main meals, 2 with snacks). In the OLE, all subjects received pancreatin. The primary efficacy measure was least squares mean CFA change from baseline to end of double-blind treatment (ancova).

RESULTS

All 58 subjects randomised (32 pancreatin, 26 placebo) completed double-blind treatment and entered the OLE; 51 completed the OLE. The least squares mean CFA change in the double-blind phase was significantly greater with pancreatin vs. placebo: 21.4% (95% CI: 13.7, 29.2) vs. -4.2% (-12.8, 4.5); difference 25.6% (13.9, 37.3), P < 0.001. The mean ± s.d. CFA increased from 53.6 ± 20.6% at baseline to 78.4 ± 20.7% at OLE end (P < 0.001). Treatment-emergent adverse events occurred in 37.5% subjects on pancreatin and 26.9% on placebo during double-blind treatment, with flatulence being the most common (pancreatin 12.5%, placebo 7.7%). Only two subjects discontinued due to treatment-emergent adverse events, both during the OLE.

CONCLUSIONS

This study demonstrates superior efficacy of pancreatin 25 000 over placebo in patients with PEI after pancreatic surgery, measured by change in CFA. Pancreatin was generally well tolerated at the high dose administered (EudraCT registration number: 2005-004854-29).

AUTEN-67, an autophagy-enhancing drug candidate with potent antiaging and neuroprotective effects

Autophagy is a major molecular mechanism that eliminates cellular damage in eukaryotic organisms. Basal levels of autophagy are required for maintaining cellular homeostasis and functioning. Defects in the autophagic process are implicated in the development of various age-dependent pathologies including cancer and neurodegenerative diseases, as well as in accelerated aging. Genetic activation of autophagy has been shown to retard the accumulation of damaged cytoplasmic constituents, delay the incidence of age-dependent diseases, and extend life span in genetic models. This implies that autophagy serves as a therapeutic target in treating such pathologies. Although several autophagy-inducing chemical agents have been identified, the majority of them operate upstream of the core autophagic process, thereby exerting undesired side effects. Here, we screened a small-molecule library for specific inhibitors of MTMR14, a myotubularin-related phosphatase antagonizing the formation of autophagic membrane structures, and isolated AUTEN-67 (autophagy enhancer-67) that significantly increases autophagic flux in cell lines and in vivo models. AUTEN-67 promotes longevity and protects neurons from undergoing stress-induced cell death. It also restores nesting behavior in a murine model of Alzheimer disease, without apparent side effects. Thus, AUTEN-67 is a potent drug candidate for treating autophagy-related diseases.

FGF signaling is required for {beta}-catenin-mediated induction of the zebrafish organizer

We have used the maternal effect mutant ichabod, which is deficient in maternal beta-catenin signaling, to test for the epistatic relationship between beta-catenin activation, FGF signaling and bozozok, squint and chordin expression. Injection of beta-catenin RNA into ichabod embryos can completely rescue normal development. By contrast, when FGF signaling is inhibited, beta-catenin did not induce goosecoid and chordin, repress bmp4 expression or induce a dorsal axis. These results demonstrate that FGF signaling is necessary for beta-catenin induction of the zebrafish organizer. We show that FGFs function downstream of squint and bozozok to turn on chordin expression. Full rescue of ichabod by Squint is dependent on FGF signaling, and partial rescue by FGFs is completely dependent on chordin. By contrast, Bozozok can rescue the complete anteroposterior axis, but not notochord, in embryos blocked in FGF signaling. Surprisingly, accumulation of bozozok transcript in beta-catenin RNA-injected ichabod embryos is also dependent on FGF signaling, indicating a role of FGFs in maintenance of bozozok RNA. These experiments show that FGF-dependent organizer function operates through both bozozok RNA accumulation and a pathway consisting of beta-catenin-->Squint-->FGF-->Chordin, in which each component is sufficient for expression of the downstream factors of the pathway, and in which Nodal signaling is required for FGF gene expression and FGF signaling is required for Squint induction of chordin.

Decreased frequency of intrathymic regulatory T cells in patients with myasthenia-associated thymoma

Naturally occurring CD4+CD25+ regulatory T cells (Treg) are essential for the control of unwanted autoimmune responses. In this study, we analysed their frequency in peripheral blood and in the thymus/thymomas of patients with myasthenia gravis (MG). We found a marked decrease in the number of CD4+CD25+ thymocytes in MG-associated thymomas, but no differences in the peripheral compartment, suggesting that the thymic development of Treg might be impaired in these patients.

Aberrant tetranectin expression in human breast carcinomas as a predictor of survival

AIMS

Tetranectin (TN), a plasminogen kringle 4 binding protein, is thought to play a prominent role in the regulation of proteolytic processes via binding to plasminogen. The aim of this study was to evaluate the expression of TN in human breast cancer and adjacent normal breast tissue and to determine the impact of this expression on survival.

METHODS

A retrospective analysis was performed on 189 patients with breast cancer, with a median follow up time of 10.6 years. The expression of TN was assessed in tumour tissue and adjacent normal breast tissue by immunohistochemistry, and the prognostic relevance of its expression in tumour cells was evaluated.

RESULTS

TN was highly expressed in connective tissue fibres surrounding normal breast epithelium, but not in normal epithelial cells. High expression of TN in tumour cells was found in 131 (69%) of the tumour samples. By western blot analysis, no significant difference in the amount and molecular weight of TN was seen between tumour tissue and normal tissue. Strong TN immunoreactivity in tumour tissue was predictive of poor disease free and tumour specific overall survival. By multivariate analysis, high TN expression in cancer cells was an independent prognostic factor for disease free and tumour specific overall survival.

CONCLUSIONS

Our results demonstrate differential TN expression in normal and malignant breast tissue and a prognostic impact of TN protein expression in breast carcinoma tissue. These data suggest a possible role of TN in invasiveness and the metastatic spread of human breast cancer.

Increased killer cell activity in aged humans

Natural cell-mediated cytotoxicity (NCMC) against a cell line (K-562) and antibody-dependent cellular cytotoxicity (ADCC) against the same target and against chicken red blood cells were investigated in two age groups (20--45 and 70--98 years old). Proliferative response to PHA and to allogenic cells as well as some subpopulation determinations were also carried out only lymphocytes of the same subjects. In contrast to the significantly decreased proliferative responses, NCMC showed a moderate, and the two ADCC values a highly significant increase in the group of aged subjects. These increased values showed some similarities with the quantitative changes within the T-lymphocyte subpopulations. The incidence of serum samples of NCMC inhibitory activity was only moderately increased in the group of aged subjects as compared to that of the young individuals. On the basis of these results, we concluded that the immune system of healthy aged subjects seems altered or inbalanced rather than depressed to that of the young individuals.

Chordin expression, mediated by Nodal and FGF signaling, is restricted by redundant function of two beta-catenins in the zebrafish embryo

Using embryos transgenic for the TOP-GFP reporter, we show that the two zebrafish beta-catenins have different roles in the organizer and germ-ring regions of the embryo. beta-Catenin-activated transcription in the prospective organizer region specifically requires beta-catenin-2, whereas the ventrolateral domain of activated transcription is abolished only when both beta-catenins are inhibited. chordin expression during zebrafish gastrulation has been previously shown in both axial and paraxial domains, but is excluded from ventrolateral domains. We show that this gene is expressed in paraxial territories adjacent to the domain of ventrolateral beta-catenin-activated transcription, with only slight overlap, consistent with the now well-known inhibitory effects of Wnt8 on dorsal gene expression. Eliminating both Wnt8/beta-catenin signaling and organizer activity by inhibition of expression of the two beta-catenins results in massive ectopic circumferential expression of chordin and later, by formation of a distinctive embryonic phenotype ('ciuffo') that expresses trunk and anterior neural markers with correct relative anteroposterior patterning. We show that chordin expression is required for this neural gene expression. The Nodal gene squint has been shown to be necessary for optimal expression of chordin and is sufficient in some contexts for its expression. However, chordin is not normally expressed in the ventrolateral germ-ring despite robust expression of squint in this domain. We show the ectopic circumferential expression of chordin and other dorsal genes to be completely dependent on Nodal and FGF signaling, and to be independent of a functional organizer. We propose that whereas the axial domain of chordin expression is formed by cells that are derived from the organizer, the paraxial domain is the result of axial-derived anti-Wnt signals, which relieve the repression that otherwise is set by the Wnt8/beta-catenin/vox,vent pathway on latent germ-ring Nodal/FGF-activated expression.