A possible postsynaptic role for SNAP-25 in hippocampal synapses

The SNARE protein SNAP-25 is well documented as regulator of presynaptic vesicle exocytosis. Increasing evidence suggests roles for SNARE proteins in postsynaptic trafficking of glutamate receptors as a basic mechanism in synaptic plasticity. Despite these indications, detailed quantitative subsynaptic localization studies of SNAP-25 have never been performed. Here, we provide novel electron microscopic data of SNAP-25 localization in postsynaptic spines. In addition to its expected presynaptic localization, we show that the protein is also present in the postsynaptic density (PSD), the postsynaptic lateral membrane and on small vesicles in the postsynaptic cytoplasm. We further investigated possible changes in synaptic SNAP-25 protein expression after hippocampal long-term potentiation (LTP). Quantitative analysis of immunogold-labeled electron microscopy sections did not show statistically significant changes of SNAP-25 gold particle densities 1 h after LTP induction, indicating that local trafficking of SNAP-25 does not play a role in the early phases of LTP. However, the strong expression of SNAP-25 in postsynaptic plasma membranes suggests a function of the protein in postsynaptic vesicle exocytosis and a possible role in hippocampal synaptic plasticity.

Abstract P5-05-03: Upregulated purinergic signaling enhances cell proliferation in human and murine breast carcinomas

The composition of the extracellular tumor microenvironment differs from that of most other tissues and is thought to provide cancer cells with a growth and survival advantage compared to normal cells. In solid tumors, the extracellular concentration of ATP can be elevated to ~100 µm and extracellular pH can be as low as 6.5. In the current project, we investigate the consequences of purinergic signaling in human and murine breast carcinomas: we study intracellular Ca2+ signals and associated changes in cell proliferation during stimulation with extracellular nucleotides.

We employ biopsies of human and murine primary breast carcinomas and compare them with matched normal breast tissue. Human biopsies are obtained with written informed consent from patients undergoing breast conserving surgery at Aarhus University Hospital or Regional Hospital Randers in Denmark. Murine biopsies are from mice overexpressing unactivated ErbB2 specifically in the breast tissue. We isolate epithelial organoids (~150 µm diameter) from tissue biopsies by partial digestion with collagenase III. Organoids loaded with the Ca2+-sensitive fluorophore Fura-2 are studied by fluorescence microscopy. In separate experiments, cell proliferation is quantified by detecting newly synthesized DNA using immunofluorescence imaging of organoids incubated with the thymidine analogue bromodeoxyuridine (BrdU).

We find that intracellular Ca2+ responses during stimulation with extracellular ATP are elevated 2- to 10-fold in breast carcinomas from mice and humans, respectively, compared to matched normal breast tissue. We observe similar differences between breast cancer tissue and normal breast tissue in response to stimulation with the P2Y2/P2Y4-agonist UTP, whereas virtually no rise in the intracellular concentration of Ca2+ is observed in response to the P2X7-agonist 3'-O-(4-benzoyl)benzoyl-ATP. Application of cyclopiazonic acid – an inhibitor of the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase – also cause exaggerated intracellular Ca2+ responses in breast cancer compared to normal breast tissue. Consistent with the elevated Ca2+ responses, stimulation with 100 µm ATP or 100 µm UTP increases the rate of cell proliferation (i.e., fraction of BrdU-positive cells) by ~2-fold in the breast cancer tissue.

In conclusion, we find that purinergic signaling is upregulated in human and murine breast carcinomas compared to normal breast tissue. Activation of purinergic receptors – most likely P2Y2 and/or P2Y4 – enhances cell proliferation in breast cancer tissue. We propose that the high ATP levels in the tumor microenvironment promote breast cancer development or progression and that the associated signaling pathways represent promising targets for therapy.

Citation Format: Mele M, McWhan K, Henningsen M, Vahl P, Jensen V, Johansen T, Pedersen H, Christiansen P, Bødtkjer E. Upregulated purinergic signaling enhances cell proliferation in human and murine breast carcinomas [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-05-03.

Abstract P3-03-02: Na+,HCO3--cotransport is the major mechanism of cellular acid extrusion in human and murine breast cancer

High metabolism and insufficient blood supply are characteristics of cancer tissue, which in combination with biochemical changes favor glycolytic metabolism and result in prominent intracellular acid production. Although extracellular pH at the core of malignant tumors is as low as one unit below normal, intracellular pH (pHi) in tumor cells is typically normal or even slightly alkaline. Thus, cancer cells must possess efficient mechanisms of acid extrusion to eliminate the excess acid load.

We investigated the role of the Na+,HCO3–cotransporter NBCn1 (SLC4A7), which in recent genome-wide association studies has been linked to human breast cancer. Based on immunohistochemistry of tumor slices and immunoblotting of enzymatically isolated epithelial organoids, we found that NBCn1 expression is upregulated in human and murine primary breast carcinomas and metastases compared to normal breast tissue. The upregulation of NBCn1 was of similar or greater magnitude than that observed for the Na+/H+-exchanger NHE1, which has previously been implicated in cell migration, proliferation and malignancy. Measurements of pHi from slices of human and murine breast cancers and from malignant and normal breast epithelial organoids showed that Na+,HCO3–cotransport is the major mechanism of acid extrusion in the near-physiological pHi range. Na+/H+-exchange was important for acid extrusion only at very low pHi values. We furthermore found that Na+,HCO3–cotransport activity was substantially greater in malignant compared to normal breast epithelial organoids of both human and murine origin, while no apparent difference in Na+/H+-exchange activity was detected between cancer and normal breast tissue. Steady-state pHi was higher in the breast cancer tissue compared to normal breast epithelium in the presence of CO2/HCO3- but not in its nominal absence.

We propose that NBCn1 plays a major role for cellular acid extrusion and pHi regulation in human and murine breast cancer. The upregulated expression of NBCn1 and the functional importance of Na+,HCO3–cotransport for pHi regulation support a causative role for NBCn1 in breast cancer development or progression.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-03-02.

P4-01-17: TIMP-1 Over-Expression Confers Resistance of MCF-7 Breast Cancer Cells to Fulvestrant

Background

Endocrine resistance represents a major challenge in the management of estrogen receptor (ER) positive breast cancer. Currently no predictive biomarkers for endocrine resistance in ERpositive breast cancer patients are in clinical use.

In a clinical study, patients with metastatic breast cancer and high levels of serum Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) had less benefit from endocrine therapy than patients with a lower level of serum TIMP-1 [1].

Therefore, we evaluated the association between TIMP-1 and response to endocrine therapy using an in vitro approach.

We have previously presented initial results on TIMP-1 and response to endocrine therapy [2].

Materials and Methods: MCF-7 cells were stably transfected with pcDNA3.1(Hyg)-TIMP-1 plasmid, and a panel of 11 subclones with different expression levels of TIMP-1 was generated. TIMP-1 expression levels were confirmed using enzyme-linked immunosorbent assay (ELISA).

Four subclones with high or low TIMP-1 expression were analyzed for the growth response to estrogen, 4-hydroxytamoxifen and fulvestrant. These four subclones were analyzed for protein expression by western blotting. All subclones were analyzed by whole human genome oligo microarrays 4×44K for determination of gene expression levels. Data were analyzed using the limma R/Bioconductor package. Paired-end Solexa sequencing was applied to selected subclones with high and low TIMP-1 levels to identify transcriptomic changes.

Results: High expression of TIMP-1 was associated with resistance to fulvestrant, whereas growth response to either estrogen or 4-hydroxytamoxifen was independent of TIMP-1 expression levels. High expression of TIMP-1 protein and mRNA was associated with undetectable levels of progesterone receptor (PgR) protein and mRNA whereas ER protein and mRNA levels were unaffected by TIMP-1. To characterize the potential role of TIMP-1 in estrogen signaling we analyzed the expression of reported estrogen-responsive genes and no general change was observed. We identified genes that correlated positively or negatively to TIMP-1 expression. Among the identified genes was PgR, which is a direct target for ER.

Conclusion: Our data suggest that a high expression of TIMP-1 in vitro is associated with resistance to fulvestrant but not to 4-hydroxytamoxifen. Estrogen-regulated genes are not generally affected by changes in TIMP-1 expression levels and therefore TIMP-1 appears to affect endocrine resistance through other mechanisms than globally regulating ER signaling. However, high expression of TIMP-1 is associated with loss of PgR and this may be related to the resistance towards fulvestrant.

References:

[1] Lipton, A et al: Serum TIMP-1 and Response to the Aromatase Inhibitor Letrozole Versus Tamoxifen in Metastatic Breast Cancer. J Clin Oncol; 2008; 26;(16); 2653–8

[2] Effect of TIMP-1 Overexpression on Endocrine Sensitivity of MCF-7 ER-positive Human Breast Cancer Cells In Vitro. Cancer Res; 2009; 69(24 suppl); abstract nr 2029

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-01-17.

Abstract P6-01-09: HER4 Is Downregulated in Lymphnode Metastases Compared to the Paired Primary Breast Carcinoma

Introduction: The Human Epidermal Growth Factor Receptor 4 (HER4) of the EGF receptor family has been characterized in both normal and malignant human breast tissue and HER4 overexpression has been shown to predict prolonged survival compared to HER4 receptor negative disease.

In our study we investigated the HER4 expression in normal breast tissue, primary breast carcinoma and in ipsilateral metastatic axillary lymphnodes at the time of primary breast cancer surgery.

Material and methods: Paired tissue samples from normal breast tissue and primary breast carcinomas were obtained from 169 patients. Out of these a third sample was obtained from 66 patients with metastatic lymphnodes. The primary tumour specimens were sampled uniformly at random. The mRNA expression of HER4 was quantified with real time RT-PCR and expressed relative to the householdgene (HMBS) in arbitrary units (arb.u.).

Results: The mRNA expression of HER4 was significantly higher in breast carcinoma with a mean of 2.26 arb.u. [95% c.i.:1.87 to 2.65 arb.u.] than in the paired sample of normal breast tissue with a mean of 0.82 arb.u. [95% c.i.: 0.47 to 1.16 arb.u.] (p=0.0001). The mRNA expression of HER4 was also significantly higher in breast carcinoma than in the corresponding lymphnode mean 0.75 arb. u. [95% c.i.: 0.43 to 1.07 arb.u.] (p=0.015). There was no significant difference observed in mRNA expression of HER4 between the metastatic lymphnode and the corresponding normal breast tissue (P>0.05). When HER4 expression was compared between the primary tumours that had metastasised and those that had not, there was no significant difference (P>0.05). Conclusion:

The HER4 expression was high in the primary tumour as compared to normal breast tissue and the corresponding lymphnode. In view of previously published relations between a low expression of HER4 and a poor prognosis our results warrant further studies in order to evaluate whether suppression of HER4 in tumour cells could be involved in lymphogenic metastatic spread.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-01-09.

Synapsin-dependent development of glutamatergic synaptic vesicles and presynaptic plasticity in postnatal mouse brain

Inactivation of the genes encoding the neuronal, synaptic vesicle-associated proteins synapsin I and II leads to severe reductions in the number of synaptic vesicles in the CNS. We here define the postnatal developmental period during which the synapsin I and/or II proteins modulate synaptic vesicle number and function in excitatory glutamatergic synapses in mouse brain. In wild-type mice, brain levels of both synapsin I and synapsin IIb showed developmental increases during synaptogenesis from postnatal days 5-20, while synapsin IIa showed a protracted increase during postnatal days 20-30. The vesicular glutamate transporters (VGLUT) 1 and VGLUT2 showed synapsin-independent development during postnatal days 5-10, following which significant reductions were seen when synapsin-deficient brains were compared with wild-type brains following postnatal day 20. A similar, synapsin-dependent developmental profile of vesicular glutamate uptake occurred during the same age periods. Physiological analysis of the development of excitatory glutamatergic synapses, performed in the CA1 stratum radiatum of the hippocampus from the two genotypes, showed that both the synapsin-dependent part of the frequency facilitation and the synapsin-dependent delayed response enhancement were restricted to the period after postnatal day 10. Our data demonstrate that while both synaptic vesicle number and presynaptic short-term plasticity are essentially independent of synapsin I and II prior to postnatal day 10, maturation and function of excitatory synapses appear to be strongly dependent on synapsin I and II from postnatal day 20.

N-methyl-D-aspartate receptor subunit dysfunction at hippocampal glutamatergic synapses in an animal model of attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is the most common neurobehavioural disorder among children. ADHD children are hyperactive, impulsive and have problems with sustained attention. These cardinal features are also present in the best validated animal model of ADHD, the spontaneously hypertensive rat (SHR), which is derived from the Wistar Kyoto rat (WKY). Current theories of ADHD relate symptom development to factors that alter learning. N-methyl-D-aspartate receptor (NMDAR) dependent long term changes in synaptic efficacy in the mammalian CNS are thought to represent underlying cellular mechanisms for some forms of learning. We therefore hypothesized that synaptic abnormality in excitatory, glutamatergic synaptic transmission might contribute to the altered behavior in SHRs. We studied physiological and anatomical aspects of hippocampal CA3-to-CA1 synapses in age-matched SHR and WKY (controls). Electrophysiological analysis of these synapses showed reduced synaptic transmission (reduced field excitatory postsynaptic potential for a defined fiber volley size) in SHR, whereas short-term forms of synaptic plasticity, like paired-pulse facilitation, frequency facilitation, and delayed response enhancement were comparable in the two genotypes, and long-term potentiation (LTP) of synaptic transmission was of similar magnitude. However, LTP in SHR was significantly reduced (by 50%) by the NR2B specific blocker CP-101,606 (10 microM), whereas the blocker had no effect on LTP magnitude in the control rats. This indicates that the SHR has a functional predominance of NR2B, a feature characteristic of early developmental stages in these synapses. Quantitative immunofluorescence and electron microscopic postembedding immunogold cytochemistry of the three major NMDAR subunits (NR1, NR2A; and NR2B) in stratum radiatum spine synapses revealed no differences between SHR and WKY. The results indicate that functional impairments in glutamatergic synaptic transmission may be one of the underlying mechanisms leading to the abnormal behavior in SHR, and possibly in human ADHD.

Impaired spatial working memory but spared spatial reference memory following functional loss of NMDA receptors in the dentate gyrus

Novel spatially restricted genetic manipulations can be used to assess contributions made by synaptic plasticity to learning and memory, not just selectively within the hippocampus, but even within specific hippocampal subfields. Here we generated genetically modified mice (NR1^ΔDG mice) exhibiting complete loss of the NR1 subunit of the N-methyl-d-aspartate receptor specifically in the granule cells of the dentate gyrus. There was no evidence of any reduction in NR1 subunit levels in any of the other hippocampal subfields, or elsewhere in the brain. NR1^ΔDG mice displayed severely impaired long-term potentiation (LTP) in both medial and lateral perforant path inputs to the dentate gyrus, whereas LTP was unchanged in CA3-to-CA1 cell synapses in hippocampal slices. Behavioural assessment of NR1^ΔDG mice revealed a spatial working memory impairment on a three-from-six radial arm maze task despite normal hippocampus-dependent spatial reference memory acquisition and performance of the same task. This behavioural phenotype resembles that of NR1^ΔCA3 mice but differs from that of NR1^ΔCA1 mice which do show a spatial reference memory deficit, consistent with the idea of subfield-specific contributions to hippocampal information processing. Furthermore, this pattern of selective functional loss and sparing is the same as previously observed with the global GluR-A l-α-amino-3-hydroxy-5-methyl-4-isoxazelopropionate receptor subunit knockout, a mutation which blocks the expression of hippocampal LTP. The present results show that dissociations between spatial working memory and spatial reference memory can be induced by disrupting synaptic plasticity specifically and exclusively within the dentate gyrus subfield of the hippocampal formation.

Massive localized lipolymphedema pseudotumor in a morbidly obese patient

We describe a 31 year old man with a massive localized tumor-like lipolymphedema, a puzzling entity that afflicts the morbidly obese. The 281 kg man presented with a growing ulcerated bleeding mass located on his proximal medial thigh and suspicious for sarcoma. After en bloc resection of the 28.2 kg edematous mass, no evidence of neoplasm was found, only prominent lymphatic vessel dilation and edema with large quantities of unremarkable adipose and connective tissue. The lesion conformed to the diagnostic criteria for massive localized lipolymphedema (MLL) pseudotumor.

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.

The anaesthetic management of a patient with Emery-Dreifuss muscular dystrophy

PURPOSE

This case report presents a patient with Emery-Dreifuss Muscular Dystrophy and describes the anaesthetic considerations.

CLINICAL FEATURES

The features of Emery-Dreifuss Muscular Dystrophy are contractures, humeroperoneal muscle weakness and cardiomyopathy. The anaesthetic considerations for this syndrome are difficult tracheal intubation, difficult spinal anaesthetic, heart block, gastric reflux, rhabdomyolysis, and unproved malignant hyperthermia susceptibility.

CONCLUSION

The major anaesthetic problem for the patient with Emery-Dreifuss Muscular Dystrophy could be a life-threatening cardiomyopathy.

MIB-1 expression and iododeoxyuridine labelling in soft tissue sarcomas: an immunohistochemical study including correlations with p53, bcl-2 and histological characteristics

We investigated the relationship between immunohistochemical estimates of proliferative activity and expression of bcl-2 protein and mutant p53 protein in 23 cases of soft tissue sarcoma. Furthermore, the reproducibility of estimates of proliferative activity was analysed and correlations between the variables and with mitotic score were investigated. Proliferative activity was assessed by use of monoclonal antibody MIB-1 and staining for iododeoxyuridine (IdUrd), and evaluated in multiple, random, systematically sampled fields of vision. MIB-1 indices were higher than those of IdUrd but for each case the two values were positively correlated (r = 0.78). The MIB-1 index correlated positively with mitotic score (2P < 0.001) and malignancy grade (2P = 0.001). The intraobserver reproducibility of the MIB-1 and IdUrd indices were excellent (r = 0.98 and r = 0.90, respectively). p53 expression was detected in 43% and strong bcl-2 expression was present in 57% of the studied cases. Expression of p53 and bcl-2 were not significantly correlated to proliferative activity or the histological features. We conclude, that the MIB-1 index is a reliable and reproducible estimate of proliferative activity and might improve the accuracy of conventional malignancy grading of soft tissue sarcomas. Furthermore, the results indicate that neither mutant p53 protein nor bcl-2 oncogene alone are sufficient to induce increased proliferation in these sarcomas.

Stereologic estimation of breast tumor size

OBJECTIVE

The largest tumor diameter, D(T), is a variable of great clinical value in breast cancer but a biased and imprecise estimator of real tumor size. Three-dimensional, shape-independent estimates would more realistically reflect the tumor bulk and provide more accurate clinical staging. For experimental oncology, the measurements may be useful for precise assessment of tumor burden.

STUDY DESIGN

In 64 prospectively collected breast cancers, unbiased stereology was used for estimating the gross tumor volume, V(T), cutting specimens into parallel, equally thick sections with subsequent determination of total tumor sectional area. For comparison, the volume of invasive tumor epithelium, "V"(epi), was obtained by microscopic examination of systematically sampled tissue fractions of the same tumors, embedded in both methacrylate and paraffin.

RESULTS

The median D(T) was 2.2 cm, and the median V(T) was 6.72 cm3. The correlation between these variables was not very close (r = .77), and the slope of the regression line was steeper than expected, presumably reflecting a change in tumor shape with growing size. The sampling scheme used for estimation of V(T) proved highly efficient, yielding a mean error coefficient of 9%. The median "V"(epi) in methacrylate was 1.19 cm3, 21% larger than in paraffin. Estimates of "V" (epi) were highly reproducible (r = .97) and correlated highly with point counting-based estimates of the feature (r = .96). "V"(epi) correlated with V(T) (r > or = .75), but the slopes of the regression lines were steeper than expected, corresponding with the correlation found between epithelial volume fraction and tumor size (r = .26). On average, about 25% of the gross tumor was composed of invasive epithelium, but with a wide range.

CONCLUSION

In breast cancer, realistic estimates of tumor volume, volume of invasive epithelium and epithelial volume fraction can be obtained by efficient stereologic techniques, which seem useful for clinical and experimental oncology. In the present methodologic study, baseline data were generated. Further studies are needed to assess the clinical value of stereologic tumor size estimates as compared with traditional staging parameters.

Quantitative histopathology in lymph node-negative breast cancer. Prognostic significance of mitotic counts

Reliable prognostic factors are needed to improve the stratification of patients with lymph node-negative breast cancer to different therapy modalities. We investigated the prognostic value of quantitative histopathology in a retrospective study of 98 "low-risk" breast cancer patients (T1+2N0M0) with a median follow-up of 9 years. An interactive video system and stereological and morphometric techniques were used to obtain estimates of four nuclear features (mean volume, mean profile area, volume fraction, and profile density), and two mitotic counts [mitotic profile frequency (MF) and mitotic profile density (MD)]. All measurements were performed in fields of vision sampled systematically from the whole tumour area of a routine histological section. Histological grade, histological type, and oestrogen receptor (ER) status was reassessed, whereas tumour diameter and age at diagnosis were recorded from the files. We found that all quantitative histopathological variables and ER status were correlated with histological grade. Single-factor prognostic analyses showed a highly significant value of MF (2p = 0.001) and a marginally significant value of MD (2p = 0.09), whereas no other variable approached statistical significance (2p > or = 0.25). In a multivariate Cox analysis, MF was the only parameter of significant independent prognostic value (2p = 0.03). Thus, the prognostic value of nuclear features found in previous studies could not be reproduced, whereas the marked value of mitotic counts for prediction of the outcome in patients with breast cancer was confirmed. Mitotic counts are easily obtained and may be of clinical value for identification of high-risk cases among patients with lymph node-negative breast cancer.

Impairment of synaptic vesicle clustering and of synaptic transmission, and increased seizure propensity, in synapsin I-deficient mice

Synapsin I has been proposed to be involved in the modulation of neurotransmitter release by controlling the availability of synaptic vesicles for exocytosis. To further understand the role of synapsin I in the function of adult nerve terminals, we studied synapsin I-deficient mice generated by homologous recombination. The organization of synaptic vesicles at presynaptic terminals of synapsin I-deficient mice was markedly altered: densely packed vesicles were only present in a narrow rim at active zones, whereas the majority of vesicles were dispersed throughout the terminal area. This was in contrast to the organized vesicle clusters present in terminals of wild-type animals. Release of glutamate from nerve endings, induced by K+,4-aminopyridine, or a Ca2+ ionophore, was markedly decreased in synapsin I mutant mice. The recovery of synaptic transmission after depletion of neurotransmitter by high-frequency stimulation was greatly delayed. Finally, synapsin I-deficient mice exhibited a strikingly increased response to electrical stimulation, as measured by electrographic and behavioral seizures. These results provide strong support for the hypothesis that synapsin I plays a key role in the regulation of nerve terminal function in mature synapses.

The prognostic value of oncogenic antigen 519 (OA-519) expression and proliferative activity detected by antibody MIB-1 in node-negative breast cancer

The prognostic value of oncogenic antigen 519 (OA-519) expression and tumour proliferative activity was evaluated in a retrospective series of 118 patients with low-risk breast cancer. Low risk was defined as negative axillary nodes, tumour diameter < or = 50 mm, and no histological evidence of invasion of skin or deep fascia (= T1N0M0 and T2N0M0). The median follow-up time was 104 months (range 5-143 months). Immunohistochemical analysis of OA-519 expression was performed on formalin-fixed, paraffin-embedded tissue. The proliferative activity was estimated using a Ki-67 equivalent monoclonal antibody (MIB-1), which is applicable on formalin-fixed, paraffin-embedded tissue after microwave pretreatment. OA-519 was expressed in about one-third of the tumours and the percentage of proliferating cells (the MIB-1 index) ranged between 1 and 72 per cent (median 17 per cent). Using multivariate Cox analysis, both the MIB-1 index and OA-519 expression were of independent prognostic value (2p < or = 0.01), and the combined immunohistological approach may therefore be useful in selecting patients with node-negative breast cancer who might benefit from adjuvant therapy.

Reducing specialty bed use

Saint Joseph Hospital is a tertiary care teaching facility with 602 licensed beds. In 1992 it was noted that there was a significant rise in the use of specialty beds within the hospital. Guidelines for selection, initiation, and termination were nonexistent. In an effort to reduce high costs associated with specialty bed use a study was conducted to determine appropriate selection criteria and monitor patient outcomes.

Immunohistochemical quantitation of oestrogen receptors and proliferative activity in oestrogen receptor positive breast cancer

AIM

To evaluate the effect of the duration of formalin fixation and of tumour heterogeneity on quantitative estimates of oestrogen receptor content (oestrogen receptor index) and proliferative activity (MIB-1 index) in breast cancer.

METHODS

Two monoclonal antibodies, MIB-1 and oestrogen receptor, were applied to formalin fixed, paraffin wax embedded tissue from 25 prospectively collected oestrogen receptor positive breast carcinomas, using a microwave antigen retrieval method. Tumour tissue was allocated systematically to different periods of fixation to ensure minimal intraspecimen variation. The percentages of MIB-1 positive and oestrogen receptor positive nuclei were estimated in fields of vision sampled systematically from the entire specimen and from the whole tumour area of one "representative" cross-section.

RESULTS

No correlation was found between the oestrogen receptor and MIB-1 indices and the duration of formalin fixation. The estimated MIB-1 and oestrogen receptor indices in tissue sampled systematically from the entire tumour were closely correlated with estimates obtained in a "representative" section. The intra- and interobserver correlation of the MIB-1 index was good, although a slight systematical error at the second assessment of the intraobserver study was noted.

CONCLUSION

Quantitative estimates of oestrogen receptor content and proliferative activity are not significantly influenced by the period of fixation in formalin, varying from less than four hours to more than 48 hours. The MIB-1 and the oestrogen receptor indices obtained in a "representative" section do not deviate significantly from average indices determined in tissue samples from the entire tumour. Finally, the estimation of MIB-1 index is reproducible, justifying its routine use.

Analysis of dendritic spines in rat CA1 pyramidal cells intracellularly filled with a fluorescent dye

The dendritic branching pattern and the distribution of dendritic spines were studied in hippocampal neurones with an improved technique. In slices taken from adult Wistar rats, CA1 pyramidal cells were filled with Lucifer yellow and examined under a laser-scanning confocal microscope. The basal dendrites were found evenly distributed inside a regular cupola-shaped volume. Their total length was about 4,500 microns. The branches divided between one and three times, with the initial segments comprising less than 2%, and the long terminal segments (mean length, 119 microns) including more than 80% of the total length of the basal dendrites. The apical dendritic branches emerged obliquely from the main shaft, ran for a distance of 50 to 250 microns, and made up a total length of about 5,100 microns in stratum radiatum and between 1,100 and 3,200 microns in stratum lacunosum-moleculare. The mean total length of the dendritic tree was 11,900 microns. All values were corrected for shrinkage. Shrinkage was measured in three dimensions and was 20.2% in the horizontal (x/y) plane and 40.9% in the vertical (z) plane. Both the basal and the apical dendritic branches were covered by regularly spaced spines. When corrected for dehydration-induced shrinkage and for hidden spines, the density was 1.80 and 2.00 spines/microns dendritic length for the basal and apical dendritic branches, respectively. Apart from the initial parts of the branches, which had few or no spines, the spines were remarkably evenly spaced. In particular, the distance between spine heads was significantly different from a random distribution, suggesting a regulatory process for the spacing of spines.

Goldhelox: a soft x-ray solar telescope

The Goldhelox Project is the construction and use of a near-normal incidence soft x-ray robotic solar telescope by undergraduate students at Brigham Young University. Once it is completed and tested, it will be deployed from a Get-Away-Special (GAS) canister in the bay of a space shuttle. It will image the sun at a wavelength of 171-181Å with a time resolution of 1 sec and a spatial resolution of 2.5 arcsec. The observational bandpass was chosen to image x-rays from highly ionized coronal Fe lines. The data will be an aid in better understanding the beginning phases of solar flares and how flaring relates to the physics of the corona-chromosphere transition region. Goldhelox is tentatively scheduled to fly on a space shuttle sometime in 1995 or 1996. This paper outlines the project goals, basic instrument design, and the unique aspects of making this an undergraduate endeavor.

Specificity of protein kinase inhibitor peptides and induction of long-term potentiation

Previous studies have used synthetic peptide analogs, corresponding to sequences within the pseudosubstrate domain of protein kinase C (PKC) or the autoregulatory domain of Ca2+/calmodulin-dependent protein kinase II (CaMKII), in attempts to define the contribution of each of these protein kinases to induction of long-term potentiation (LTP). However, the specificity of these inhibitor peptides is not absolute. Using intracellular delivery to rat CA1 hippocampal neurons, we have determined the relative potency of two protein kinase inhibitor peptides, PKC-(19-36) and [Ala286]CaMKII-(281-302), as inhibitors of the induction of LTP. Both peptides blocked the induction of LTP; however, PKC-(19-36) was 30-fold more potent than [Ala286]CaMKII-(281-302). The relative specificity of PKC-(19-36), [Ala286]CaMKII-(281-302), and several other CaMKII peptide analogs for protein kinase inhibition in vitro was also determined. A comparison of the potencies of PKC-(19-36) and [Ala286]CaMKII-(281-302) in the physiological assay with their Ki values for protein kinase inhibition in vitro indicates that the blockade of induction of LTP observed for each peptide is attributable to inhibition of PKC.

Tardy posterior interosseous nerve palsy as a result of an unreduced radial head dislocation in Monteggia fractures: a report of two cases

Tardy palsy of the posterior interosseous nerve after a malunited Monteggia fracture with an unreduced dislocation of the radial head is considered to be extremely rare. Four earlier cases were treated by excision of the radial head or by tendon transfers. Another two cases have been reported, both treated successfully by decompression of the nerve in the radial tunnel between the two heads of the supinator. This simple operation should be given a trial before tendon transfers are considered, even if the palsy has been of long duration.

Influence of moderate alcohol intake on wakening plasma thiopental concentration

In an earlier study, an inverse correlation between thiopental-induced sleeping time and alcohol intake in the preceding week was demonstrated in women undergoing termination of pregnancy. In order to investigate the mechanism behind the apparent cross-tolerance, the relationship between alcohol consumption in the week preceding thiopental/nitrous oxide/oxygen anesthesia and wakening plasma thiopental concentration on one hand and sleeping time on the other was examined in 68 women scheduled for termination of pregnancy and in 37 women scheduled for diagnostic uterine dilatation and curettage. In terms of pure alcohol, the weekly intake (mean +/- s.d.) was 1.17 +/- 2.07 ml . kg-1 in the former and 1.49 +/- 1.70 ml . kg-1 in the latter group. A positive correlation between alcohol consumption and wakening plasma thiopental concentration was found in both groups, reaching statistical significance (P less than 0.05) in the group undergoing termination of pregnancy, but not in the other. The inverse correlation found earlier between alcohol intake and sleeping time was not reproduced significantly in any of the groups. The results indicate that moderate alcohol intake may induce cerebral tolerance to thiopental.

Femoral-femoral cardiopulmonary bypass prior to induction of anaesthesia in the management of upper airway obstruction

A case is presented of a female with respiratory distress who was initially treated as having asthma. Her chest x-ray was normal but tracheal tomograms revealed a tracheal tumour almost completely occluding the tracheal lumen. The impending tracheal occlusion was managed with femoral-femoral cardiopulmonary bypass instituted under local anaesthesia prior to induction of anaesthesia and diagnostic bronchoscopy and airway establishment with tracheal intubation. Other indications for the use of cardiopulmonary bypass prior to the induction of anaesthesia are reviewed.

Influence of moderate alcohol intake on thiopental anesthesia

The relationship between alcohol intake over the week preceding anesthesia and various anesthetic parameters was examined in 119 women scheduled for termination of pregnancy under thiopental-nitrous oxide anesthesia. In terms of pure alcohol, the weekly intake was 1.03 +/- 1.09 ml.kg-1 (mean +/- s.d.), range 0-5.93, i.e. below average consumption in Denmark. Alcohol intake was negatively correlated with anesthetic sleeping time (P less than 0.01). Time and quality of anesthesia induction and frequency of anesthetic complications were not significantly correlated with the use of alcohol. Preanesthetic anxiety was not significantly correlated with any of the above data. Induction time and postoperative awareness were positively and sleeping time negatively correlated with age (P less than 0.05). The results indicate cross-tolerance between alcohol and thiopental, even when the regular intake of the former is low, and increasing thiopental requirements with increasing age.

A study of the rate of carbon dioxide output during mineralization of some organic materials in soil

Soil respiration (CO2-evolution) was measured at different intervals during mineralization of organic materials in an Egyptian clay-loam soil. The rate of CO2 output was found to decline by time, and a linear negative correlation was found between the logarithm of time and the logarithm of the rate of CO2 output. Applying the linear regression equation it was possible to describe this relationship mathematically. A significant positive correlation was also found between the rate of CO2 output and the total plate count of bacteria and the ATP content of the soil.

The redox potential of growing cultures of Streptococcus bovis Orla-Jensen compared with other facultative anaerobes

The changes of redox potential were measured in growing cultures of three strains of Streptococcus bovis, together with three strains of Staphylococcus aureus and one strain of each of Lactobacillus plantaram, Lactobacillus casei, and Eschericia coli. It was found that both S. aureus and E. coli could reduce the redox potential of the growth medium to very low values (between —400 mv and —600 mv), whereas the streptococci and lactobacilli were able to cause only slight or insignificant changes of the redox potential. Respirometric measurements confirmed that the capacity of oxygen consumption of S. bovis was very small compared to that of E. coli and S. aureus. On this basis the authors conclude that S. bovis in all probability is unable to contribute significantly to maintenance of the low redox potential of its natural habitat, the rumen. This function must be carried out by other bacteria, such as enterobacteria or staphylococci, which are capable of performing a true, aerobic respiration.