A genetic switch for epilepsy in adult mice

Premature death from seizures afflicts gene-targeted mice expressing the Q/R site-unedited glutamate receptor subunit GluR-B(Q) of AMPA receptors in central neurons. Early seizure-related death has now been circumvented by a genetic switch that restricts GluR-B(Q) expression to forebrain principal neurons from postnatal stages onward, prominently in hippocampus and striatum and less so in cortex and amygdala. When switched on, functional receptor incorporation of GluR-B(Q) could be demonstrated by imaging evoked AMPA channel-mediated spinous Ca2+ transients in CA1 pyramidal cells. Sustained GluR-B(Q) expression in adult mice led to smaller excitatory postsynaptic responses in the CA1 region with unchanged presynaptic fiber excitability. Notably, despite the smaller excitatory response, the CA1 cells exhibited a reduced population spike threshold, which might underlie the spontaneous manifestations of epilepsy, including myocloni and generalized seizures with limbic components, observed by synchronous video monitoring and electroencephalographic recordings. No neuropathological symptoms developed when GluR-B(Q) expression was restricted to only hippocampal neurons. Our results show that seizure susceptibility is triggered by GluR-B(Q) expression also in the adult brain and that circuit hyperexcitability is not an immediate consequence of GluR-B(Q) but requires yet unknown downstream events, likely to be induced by non-Hebbian plasticity from Ca2+-permeable AMPA channels in principal neurons.

Mice with a fra-1 knock-in into the c-fos locus show impaired spatial but regular contextual learning and normal LTP

The immediate early gene c-fos is part of the AP-1 transcription factor complex, which is involved in molecular mechanisms underlying learning and memory. Mice that lack c-Fos in the brain show impairments in spatial reference and contextual learning, and also exhibit a reduced long-term potentiation of synaptic transmission (LTP) at CA3-to-CA1 synapses. In the present study, we investigated mice in which c-fos was deleted and replaced by fra-1 (c-fos(fra-1) mice) to determine whether other members of the c-fos gene family can substitute for the functions of the c-fos gene. In c-fos(fra-1) mice, both CA3-to-CA1 LTP and contextual learning in a Pavlovian fear conditioning task were similar to wild-type littermates, indicating that Fra-1 expression restored the impairments caused by brain-specific c-Fos depletion. However, c-Fos-mediated learning deficits in a reference memory task of the Morris watermaze were also present in c-fos(fra-1) mice. These findings suggest that different c-Fos target genes are involved in LTP, contextual learning, and spatial reference memory formation.

Intracellular domains of NMDA receptor subtypes are determinants for long-term potentiation induction

NMDA receptors (NMDARs) are essential for modulating synaptic strength at central synapses. At hippocampal CA3-to-CA1 synapses of adult mice, different NMDAR subtypes with distinct functionality assemble from NR1 with NR2A and/or NR2B subunits. Here we investigated the role of these NMDA receptor subtypes in long-term potentiation (LTP) induction. Because of the higher NR2B contribution in the young hippocampus, LTP of extracellular field potentials could be enhanced by repeated tetanic stimulation in young but not in adult mice. Similarly, NR2B-specific antagonists reduced LTP in young but only marginally in adult wild-type mice, further demonstrating that in mature CA3-to-CA1 connections LTP induction results primarily from NR2A-type signaling. This finding is also supported by gene-targeted mutant mice expressing C-terminally truncated NR2A subunits, which participate in synaptic NMDAR channel formation and Ca2+ signaling, as indicated by immunopurified synaptic receptors, postembedding immunogold labeling, and spinous Ca2+ transients in the presence of NR2B blockers. These blockers abolished LTP in the mutant at all ages, revealing that, without the intracellular C-terminal domain, NR2A-type receptors are deficient in LTP signaling. Without NR2B blockade, CA3-to-CA1 LTP was more strongly reduced in adult than young mutant mice but could be restored to wild-type levels by repeated tetanic stimulation. Thus, besides NMDA receptor-mediated Ca2+ influx, subtype-specific signaling is critical for LTP induction, with the intracellular C-terminal domain of the NR2 subunits directing signaling pathways with an age-dependent preference.

A juvenile form of postsynaptic hippocampal long-term potentiation in mice deficient for the AMPA receptor subunit GluR-A

In adult mice, long-term potentiation (LTP) of synaptic transmission at CA3-to-CA1 synapses induced by tetanic stimulation requires L-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors containing GluR-A subunits. Here, we report a GluR-A-independent form of LTP, which is comparable in size to LTP in wild-type mice at postnatal day 14 (P14) but diminishes between P14 and P42 in brain slices of GluR-A-deficient mice. The GluR-A-independent form of LTP is sensitive to D(-)-2-amino-5-phosphonopentanoic acid (D-AP5), but lacks short-term potentiation (STP) and can also be observed in the pairing induction protocol. As judged by unaltered paired-pulse facilitation, this LTP form is postsynaptically expressed despite depleted extrasynaptic AMPA receptor pools with reduced levels of GluR-B, which accumulates in somata and synapses of CA1 pyramidal neurons in GluR-A-deficient mice. Our results show that in the developing hippocampus synaptic plasticity can be expressed by AMPA receptors lacking the GluR-A subunit.

Impaired long-term memory and NR2A-type NMDA receptor-dependent synaptic plasticity in mice lacking c-Fos in the CNS

The immediate early gene c-fos is part of the activator protein-1 transcription factor and has been postulated to participate in the molecular mechanisms of learning and memory. To test this hypothesis in vivo, we generated mice with a nervous system-specific c-fos knock-out using the Cre-loxP system. Adult mice lacking c-Fos in the CNS (c-fosDeltaCNS) showed normal general and emotional behavior but were specifically impaired in hippocampus-dependent spatial and associative learning tasks. These learning deficits correlated with a reduction of long-term potentiation (LTP) in hippocampal CA3-CA1 synapses. The magnitude of LTP was restored by a repeated tetanization procedure, suggesting impaired LTP induction in c-fosDeltaCNS mice. This rescue was blocked by a selective inhibitor of NR2B-type NMDA receptors. This blockade was compensated in wild-type mice by NR2A-type NMDA receptor-activated signaling pathways, thus indicating that these pathways are compromised in c-fosDeltaCNS mice. In summary, our data suggest a role for c-Fos in hippocampus-dependent learning and memory as well as in NMDA receptor-dependent LTP formation.

Levels of tissue inhibitor of metalloproteinases-1 in blood transfusion components

Blood transfusion during surgery for solid tumors may reduce patient survival because of various bioactive substances present in blood preparations. The anti-proteolytic protein tissue inhibitor of metalloproteinases-1 (TIMP-1) present in large quantities in platelets has been shown to stimulate cell growth and to inhibit apoptosis and may therefore be considered to influence tumor progression. We measured TIMP-1 levels in blood transfusion preparations. especially in platelet-containing preparations, before and after leucofiltration and at different time-points during storage. The mean TIMP-1 levels in whole blood (WB) and platelet-rich plasma (PRP) were slightly reduced by leucofiltration; WB: 41.6 microg/L versus 34.9 microg/L. PRP: 139.8 microg/L versus 127.2 microg/L. However, with prestorage leucofiltration. TIMP-1 levels in buffy-coat-derived platelet (BCP) pools were significantly reduced from 134.2 microg/L to 102.2 microg/L (p=0.0013). In saline-adenine-glucose-mannitol (SAG-M) blood preparations in which the platelet content is reduced by more than 99%,. TIMP-1 could not be detected. Extracellular TIMP-1 accumulated significantly in non-filtered WB and in aferesis platelet concentrates (APC), but TIMP-1 was at no time detectable in SAG-M blood during storage. In conclusion. TIMP-1 is present in various platelet-containing blood preparations, but not in platelet-free preparations such as SAG-M, indicating that most of the TIMP-1 measured in blood preparations originates from platelets. Furthermore, TIMP-1 levels increased during storage in preparations containing platelets. which suggests a continuous disintegration of platelets. These data imply that information on preoperative blood transfusions should be taken into account when evaluating plasma TIMP-1 levels in patients.

Conditional restoration of hippocampal synaptic potentiation in Glur-A-deficient mice

Plasticity of mature hippocampal CA1 synapses is dependent on l-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors containing the glutamate receptor A (GluR-A) subunit. In GluR-A-deficient mice, plasticity could be restored by controlled expression of green fluorescent protein (GFP)-tagged GluR-A, which contributes to channel formation and displayed the developmental redistribution of AMPA receptors in CA1 pyramidal neurons. Long-term potentiation (LTP) induced by pairing or tetanic stimulation was rescued in adult GluR-A(-/-) mice when (GFP)GluR-A expression was constitutive or induced in already fully developed pyramidal cells. This shows that GluR-A-independent forms of synaptic plasticity can mediate the establishment of mature hippocampal circuits that are prebuilt to express GluR-A-dependent LTP.

Cloning of an Mx cDNA from Atlantic halibut (Hippoglossus hippoglossus) and characterization of Mx mRNA expression in response to double-stranded RNA or infectious pancreatic necrosis virus

Mx proteins are GTPases that are specifically induced by type I interferons (IFN) in vertebrates. Some mammalian Mx proteins have antiviral activity against certain RNA viruses. A 2.3-kb full-length cDNA clone of an Atlantic halibut Mx gene was isolated from a liver cDNA library. The open reading frame (ORF) predicts a 622 amino acid protein of 71.2 kDa possessing a tripartite GTP binding motif, a dynamin signature, and a leucine zipper motif, which are conserved in all known Mx proteins. The C-terminal half contains a putative bipartite nuclear localization signal. The deduced halibut Mx protein showed approximately 76% sequence identity with the Atlantic salmon and rainbow trout Mx proteins, 55% identity with the human MxA, and 48% identity with the chicken Mx protein. Based on sequence comparison of 554-bp Mx cDNA fragments, the Atlantic halibut Mx showed more relationship with the perch and turbot than the salmonid Mx genes. Halibut appears to possess at least two Mx loci, as suggested by Southern blot analysis of genomic DNA. Two halibut Mx transcripts (2.2 kb and 2.6 kb) were strongly induced in vivo by the double-stranded RNA (dsRNA) poly I:C or infectious pancreatic necrosis virus (IPNV) in all organs studied.

Protein phosphatase-1 regulation in the induction of long-term potentiation: heterogeneous molecular mechanisms

Protein phosphatase inhibitor-1 (I-1) has been proposed as a regulatory element in the signal transduction cascade that couples postsynaptic calcium influx to long-term changes in synaptic strength. We have evaluated this model using mice lacking I-1. Recordings made in slices prepared from mutant animals and also in anesthetized mutant animals indicated that long-term potentiation (LTP) is deficient at perforant path-dentate granule cell synapses. In vitro, this deficit was restricted to synapses of the lateral perforant path. LTP at Schaffer collateral-CA1 pyramidal cell synapses remained normal. Thus, protein phosphatase-1-mediated regulation of NMDA receptor-dependent synaptic plasticity involves heterogeneous molecular mechanisms, in both different dendritic subregions and different neuronal subtypes. Examination of the performance of I-1 mutants in spatial learning tests indicated that intact LTP at lateral perforant path-granule cell synapses is either redundant or is not involved in this form of learning.

Dysfunctions in mice by NMDA receptor point mutations NR1(N598Q) and NR1(N598R)

NMDA receptors in mice were mutated by gene targeting to substitute asparagine (N) in position 598 of the NR1 subunit to glutamine (Q) or arginine (R). Animals expressing exclusively the mutated NR1 alleles, NR1(Q/Q) and NR1(-/R) mice, developed a perinatally lethal phenotype mainly characterized by respiratory failure. The dysfunctions were partially rescued in heterozygous mice by the presence of pure wild-type receptors. Thus, NR1(+/Q) mice exhibited reduced life expectancy, with females being impaired in nurturing; NR1(+/R) mice displayed signs of underdevelopment such as growth retardation and impaired righting reflex, and died before weaning. We analyzed the key properties of NMDA receptors, high Ca(2+) permeability, and voltage-dependent Mg(2+) block, in the mutant mice. Comparison of the complex physiological and phenotypical changes observed in the different mutants indicates that properties controlled by NR1 subunit residue N598 are important for autonomic brain functions at birth and during postnatal development. We conclude that disturbed NMDA receptor signaling mediates a variety of neurological phenotypes.

Occupational use of precision grip and forceful gripping, and arthrosis of finger joints: a literature review

A systematic review of arthrosis of finger joints in relation to occupational exposure revealed 11 epidemiological studies and 13 case reports. All studies but one were cross-sectional rendering demonstration of causation problematic. The reviewed literature also had drawbacks relating to exposure classification, confounding and non-attendance. Four studies showed an association between extensive use of precision grip and development of arthrosis of the distal interphalangeal joints of fingers. Two studies found an association between forceful gripping and the occurrence of arthrosis involving the metacarpophalangeal joints. Arthrosis of the proximal interphalangeal joints and first carpo-metacarpal joints was not related to any specific occupational task. Well-designed studies are needed to further elucidate this possible occupational hazard.

Importance of AMPA receptors for hippocampal synaptic plasticity but not for spatial learning

Gene-targeted mice lacking the L-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor subunit GluR-A exhibited normal development, life expectancy, and fine structure of neuronal dendrites and synapses. In hippocampal CA1 pyramidal neurons, GluR-A-/- mice showed a reduction in functional AMPA receptors, with the remaining receptors preferentially targeted to synapses. Thus, the CA1 soma-patch currents were strongly reduced, but glutamatergic synaptic currents were unaltered; and evoked dendritic and spinous Ca2+ transients, Ca2+-dependent gene activation, and hippocampal field potentials were as in the wild type. In adult GluR-A-/- mice, associative long-term potentiation (LTP) was absent in CA3 to CA1 synapses, but spatial learning in the water maze was not impaired. The results suggest that CA1 hippocampal LTP is controlled by the number or subunit composition of AMPA receptors and show a dichotomy between LTP in CA1 and acquisition of spatial memory.

Phosphorylation of the inositol 1,4,5-trisphosphate receptor by cyclic nucleotide-dependent kinases in vitro and in rat cerebellar slices in situ

We have examined cyclic nucleotide-regulated phosphorylation of the neuronal type I inositol 1,4,5-trisphosphate (IP3) receptor immunopurified from rat cerebellar membranes in vitro and in rat cerebellar slices in situ. The isolated IP3 receptor protein was phosphorylated by both cAMP- and cGMP-dependent protein kinases on two distinct sites as determined by thermolytic phosphopeptide mapping, phosphopeptide 1, representing Ser-1589, and phosphopeptide 2, representing Ser-1756 in the rat protein (Ferris, C. D., Cameron, A. M., Bredt, D. S., Huganir, R. L., and Snyder, S. H. (1991) Biochem. Biophys. Res. Commun. 175, 192-198). Phosphopeptide maps show that cAMP-dependent protein kinase (PKA) labeled both sites with the same time course and same stoichiometry, whereas cGMP-dependent protein kinase (PKG) phosphorylated Ser-1756 with a higher velocity and a higher stoichiometry than Ser-1589. Synthetic decapeptides corresponding to the two phosphorylation sites (peptide 1, AARRDSVLAA (Ser-1589), and peptide 2, SGRRESLTSF (Ser-1756)) were used to determine kinetic constants for the phosphorylation by PKG and PKA, and the catalytic efficiencies were in agreement with the results obtained by in vitro phosphorylation of the intact protein. In cerebellar slices prelabeled with [32P]orthophosphate, activation of endogenous kinases by incubation in the presence of cAMP/cGMP analogues and specific inhibitors of PKG and PKA induced in both cases a 3-fold increase in phosphorylation of the IP3 receptor. Thermolytic phosphopeptide mapping of in situ labeled IP3 receptor by PKA showed labeling on the same sites (Ser-1589 and Ser-1756) as in vitro. In contrast to the findings in vitro, PKG preferentially phosphorylated Ser-1589 in situ. Because both PKG and the IP3 receptor are specifically enriched in cerebellar Purkinje cells, PKG may be an important IP3 receptor regulator in vivo.

Neurological dysfunctions in mice expressing different levels of the Q/R site-unedited AMPAR subunit GluR-B

We generated mouse mutants with targeted AMPA receptor (AMPAR) GluR-B subunit alleles, functionally expressed at different levels and deficient in Q/R-site editing. All mutant lines had increased AMPAR calcium permeabilities in pyramidal neurons, and one showed elevated macroscopic conductances of these channels. The AMPAR-mediated calcium influx induced NMDA-receptor-independent long-term potentiation (LTP) in hippocampal pyramidal cell connections. Calcium-triggered neuronal death was not observed, but mutants had mild to severe neurological dysfunctions, including epilepsy and deficits in dendritic architecture. The seizure-prone phenotype correlated with an increase in the macroscopic conductance, as independently revealed by the effect of a transgene for a Q/R-site-altered GluR-B subunit. Thus, changes in GluR-B gene expression and Q/R site editing can affect critical architectural and functional aspects of excitatory principal neurons.

Proliferative activity (MIB-1 index) is an independent prognostic parameter in patients with high-grade soft tissue sarcomas of subtypes other than malignant fibrous histiocytomas: a retrospective immunohistological study including 216 soft tissue sarcomas

AIMS

To evaluate the prognostic value of tumour proliferative activity, p53 accumulation and bcl-2 expression in a retrospective series of 216 patients with soft tissue sarcomas (STS).

METHODS AND RESULTS

The immunohistochemical analyses were performed on formalin-fixed, paraffin-embedded tissue. The proliferative activity was assessed by use of the monoclonal antibody MIB-1 and evaluated in multiple, random systematic sampled fields of vision. The percentage of proliferating cells (the MIB-1 index) ranged between 1% and 85% (median 12%). A significant increase in mean MIB-1 index was seen with increasing histological malignancy grade. Variation in the incidence of p53 accumulation and bcl-2 positivity among different histological subtypes was observed. p53 accumulation was frequent in synovial sarcomas and leiomyo- and rhabdomyosarcomas, whereas bcl-2 preferentially was expressed in synovial sarcomas. Univariate analysis identified patient age, tumour size, histological grade of malignancy, MIB-1 index and p53 accumulation as significant prognostic parameters. Multivariate Cox analysis, including tests for interaction terms between histological subtypes and MIB-1 index, showed independent prognostic effect of MIB-1 index and tumour size in patients with high-grade tumours of other subtypes than malignant fibrous histiocytoma (MFH).

CONCLUSIONS

Histopathological malignancy grading is the most important single prognostic factor for overall survival in STS, but estimation of MIB-1 index is useful for identifying the least favourable subgroup of high grade STS of other subtypes than MFH, for whom adjuvant therapy may be indicated.

Importance of the intracellular domain of NR2 subunits for NMDA receptor function in vivo

NMDA receptors, a class of glutamate-gated cation channels with high Ca2+ conductance, mediate fast transmission and plasticity of central excitatory synapses. We show here that gene-targeted mice expressing NMDA receptors without the large intracellular C-terminal domain of any one of three NR2 subunits phenotypically resemble mice made deficient in that particular subunit. Mice expressing the NR2B subunit in a C-terminally truncated form (NR2B(deltaC/deltaC) mice) die perinatally. NR2A(deltaC/deltaC) mice are viable but exhibit impaired synaptic plasticity and contextual memory. These and NR2C(deltaC/deltaC) mice display deficits in motor coordination. C-terminal truncation of NR2 subunits does not interfere with the formation of gateable receptor channels that can be synaptically activated. Thus, the phenotypes of our mutants appear to reflect defective intracellular signaling.

Prevalence of carcinoma in situ of the testis in 207 oligozoospermic men from infertile couples: prospective study of testicular biopsies

OBJECTIVE

To investigate the prevalence of carcinoma in situ of the testis in a group of oligozoospermic men from infertile couples.

DESIGN

A consecutive group of oligozoospermic men from infertile couples were offered bilateral testicular biopsy. The observed prevalence of carcinoma in situ was compared with the expected prevalence of testicular cancer in a corresponding age matched population of Danish men, assuming all untreated cases of carcinoma in situ progress to tumour stage. This calculation was based on data from the Danish Cancer Registry.

SUBJECTS

207 men aged 18-50 years who had sperm density below 10 million/ml in two samples within the previous 2 years or sperm density below 20 million/ml in two samples within the previous 2 years and a history of cryptorchidism or one or two atrophic testicles (orchidometer volume less than 15 cm3), or both.

INTERVENTIONS

Bilateral testicular biopsies.

MAIN OUTCOME MEASURES

Carcinoma in situ in the biopsy specimen.

RESULTS

No case of carcinoma in situ was found among the 207 men. The expected number in a normal age matched population of corresponding size was 0.8.

CONCLUSIONS

There is no increase in risk of carcinoma in situ of the testis in moderately oligozoospermic men of couples referred because of infertility.

MIB-1 expression in breast carcinomas with medullary features. An immunohistological study including correlations with p53 and bcl-2

Typical medullary carcinoma (TMC) is usually considered to have a more favourable prognosis than other types of infiltrating breast carcinomas. This is a biological paradox, since its clinical behaviour is not in agreement with its anaplastic morphology and high mitotic rate. It should be remembered that neoplastic growth reflects cell production minus cell loss, the latter being achieved by apoptosis. At present, bcl-2 oncogene (apoptosis inhibitor) and p53 gene are assumed to be involved in the regulation of cell death and tumour proliferation. Sixty breast carcinomas, initially indexed as medullary carcinomas, were re-classified using the diagnostic criteria given by Ridolfi. This review yielded 13 typical (TMC), 24 atypical (AMC), and 23 non-medullary carcinomas (NMC). Following antigen retrieval by microwave treatment, immunohistochemical analyses, using MIB-1, p53 and bcl-2 monoclonal antibodies were performed on serial sections from formalin-fixed, paraffin-embedded specimens. TMC revealed the highest incidence of intense p53 positivity, and the highest mean MIB-1 index, and absence of the apoptosis-inhibitor protein bcl-2. These results suggest the presence of a higher overall cell turnover in TMC than in AMC and NMC. Increased apoptosis balancing the increased cell proliferation might be among the possible explanations for the more favourable prognosis in TMC.

Total number of cancer cell nuclei and mitoses in breast tumors estimated by the optical disector

OBJECTIVE

The total number of cancer cell nuclei, N(nuc), and of mitoses, N(mit), in the primary lesion are potentially important indicators of tumor biology. In the present study, such estimates were obtained on breast cancers by an unbiased stereologic method.

STUDY DESIGN

The total number estimates are the product of two variables: (1) the volume of tumor, V(T), estimated by the Cavalieri principle, and (2) the densities of cancer cell nuclei and of mitoses obtained in small, three-dimensional samples (i.e., optical disectors) of 40-micron-thick methacrylate sections, which were selected systematically at random from the whole specimen.

RESULTS

In 93 prospectively collected tumors, N(nuc) ranged from 0.06 to 7.9 10(9) (median, 0.6 10(9)), and N(mit) ranged from 0.02 to 64 10(6) (median, 1.5 10(6)). Both N(nuc) and N(mit) correlated significantly with V(T) (r = .77 and .60, respectively); however, the steep slopes of the regression lines indicated that densities of nuclei and mitoses increased as a function of tumor size. On average, N(mit) and estimates of mitotic frequency tended to be larger in lymph node-positive patients as compared with lymph node-positive patients as compared with lymph node-negative ones (2P < or = .08), whereas no such relation was found for nuclear counts (2P > or = .40). By counting a median number of 195 nuclei and 28 mitoses per tumor, the average coefficients of error of N(nuc) and N(mit) were 17% and 32%, respectively; this gave seemingly sufficient precision as compared with the huge interpatient variation in estimates, 180% and 490%. Moreover, the intraobserver reproducibility of density estimates was excellent (r > or = .88).

CONCLUSION

The present study showed the feasibility, efficiency and reproducibility of the unbiased optical disector principle applied to human breast cancer and provided data on new parameters of biologic relevance. The technique seems suitable for use in experimental oncology, but further studies are needed to investigate its clinical value.

Prognostic comparison of three classifications for medullary carcinomas of the breast

The aim of this study was to make prognostic comparisons between the modified scheme of Pedersen et al. the definitions of Tavassoli and the Ridolfi criteria for medullary carcinomas. Sixty breast carcinomas primarily diagnosed as medullary carcinomas were reclassified into typical medullary carcinoma (TMC), atypical medullary carcinoma (AMC) and non-medullary carcinoma (NMC) according to the three classifications. The Ridolfi classification proved to be superior to the two other schemes in discriminating survival differences between the three groups TMC, AMC and NMC. All 13 patients with TMC are still alive indicating an excellent prognosis, while 29% and 39% of the 47 patients in the AMC and NMC category, respectively, have died of their disease. In the simplified system of Pedersen et al. the survival at 10 years for TMC patients decreased to 75% and no significant survival difference between the three groups could be demonstrated. As the prognosis for AMC proved to be worse compared to TMC and in fact was similar to NMC with values of 43% at 10 years in the Ridolfi classification, we find no reasons to maintain this category. We conclude that as long as no alternative and more easily applicable diagnostic method exists, pathologists should still apply the Ridolfi criteria on these tumours with medullary features leaving two diagnostic possibilities: TMC or NMC (i.e. poorly differentiated ductal carcinoma). Only lesions that fulfil all six criteria without any doubt should be diagnosed as TMC, thus avoiding overdiagnosis and a resulting risk of undertreatment.

NASA G-133 "GoldHelox": A Project Update

NASA G-133, also known as the "GoldHelox Project", is a fully autonomous, soft X-ray, solar telescope designed for use on board the space shuttle. Conceived, designed and built by students at Brigham Young University, it will image the sun with a spatial resolution of 2.5 arc-seconds with a temporal resolution of one second. The instrument will image X-rays with wavelengths between 171Å and 181Å coming from highly ionized Fe lines in the sun's corona. Data will consist of several hundred high resolution photographs that will help in understanding the initial phases of solar flares, and the relationship between solar flares and the physics of the coronal-chromospheric transition region. This paper briefly outlines the project's goals, gives a brief overview of the construction and operation of the instrument and addresses the unique aspects of running a predominantly undergraduate research project. It summarizes the lessons learned to date, and the current project status.