A dual nociceptin and mu opioid receptor agonist exhibited robust antinociceptive effect with decreased side effects

The compelling demand of a consummate analgesic medication without addiction is rising due to the clinical mistreatment. Additionally, the series of severe untoward effects usually deterred the utilization while coping with serious pain. As a possible turning point, we revealed that compound 14 is a dual agonist of mu opioid receptor (MOR) and nociceptin-orphanin FQ opioid peptide (NOP) receptor in this study. More importantly, compound 14 achieves pain relieving at very small doses, meanwhile, reduces several unwanted side effects such as constipation, reward, tolerance and withdrawal effects. Here, we evaluated the antinociception and side effects of this novel compound from wild type and humanized mice to further develop a safer prescription analgesic drug.

Increased activation of HDAC1/2/6 and Sp1 underlies therapeutic resistance and tumor growth in glioblastoma

BACKGROUND

Glioblastoma is associated with poor prognosis and high mortality. Although the use of first-line temozolomide can reduce tumor growth, therapy-induced stress drives stem cells out of quiescence, leading to chemoresistance and glioblastoma recurrence. The specificity protein 1 (Sp1) transcription factor is known to protect glioblastoma cells against temozolomide; however, how tumor cells hijack this factor to gain resistance to therapy is not known.

METHODS

Sp1 acetylation in temozolomide-resistant cells and stemlike tumorspheres was analyzed by immunoprecipitation and immunoblotting experiments. Effects of the histone deacetylase (HDAC)/Sp1 axis on malignant growth were examined using cell proliferation-related assays and in vivo experiments. Furthermore, integrative analysis of gene expression with chromatin immunoprecipitation sequencing and the recurrent glioblastoma omics data were also used to further determine the target genes of the HDAC/Sp1 axis.

RESULTS

We identified Sp1 as a novel substrate of HDAC6, and observed that the HDAC1/2/6/Sp1 pathway promotes self-renewal of malignancy by upregulating B cell-specific Mo-MLV integration site 1 (BMI1) and human telomerase reverse transcriptase (hTERT), as well as by regulating G2/M progression and DNA repair via alteration of the transcription of various genes. Importantly, HDAC1/2/6/Sp1 activation is associated with poor clinical outcome in both glioblastoma and low-grade gliomas. However, treatment with azaindolyl sulfonamide, a potent HDAC6 inhibitor with partial efficacy against HDAC1/2, induced G2/M arrest and senescence in both temozolomide-resistant cells and stemlike tumorspheres.

CONCLUSION

Our study uncovers a previously unknown regulatory mechanism in which the HDAC6/Sp1 axis induces cell division and maintains the stem cell population to fuel tumor growth and therapeutic resistance.

Betulinic Acid-Mediated Tuning of PERK/CHOP Signaling by Sp1 Inhibition as a Novel Therapeutic Strategy for Glioblastoma

Patients with glioblastoma are at high risk of local recurrences after initial treatment with standard therapy, and recurrent tumor cells appear to be resistant to first-line drug temozolomide. Thus, finding an effective second-line agent for treating primary and recurrent glioblastomas is critical. Betulinic acid (BA), a natural product of plant origin, can cross the blood-brain barrier. Here, we investigated the antitumor effects of BA on typical glioblastoma cell lines and primary glioblastoma cells from patients, as well as corresponding temozolomide-resistant cells. Our findings verified that BA significantly reduced growth in all examined cells. Furthermore, gene-expression array analysis showed that the unfolded-protein response was significantly affected by BA. Moreover, BA treatment increased activation of the protein kinase RNA-like endoplasmic reticulum kinase (PERK)/C/EBP homologous protein (CHOP) apoptotic pathway, and reduced specificity protein 1 (Sp1) expression. However, Sp1 overexpression reversed the observed cell-growth inhibition and PERK/CHOP signaling activation induced by BA. Because temozolomide-resistant cells exhibited significantly increased Sp1 expression, we concluded that Sp1-mediated PERK/CHOP signaling inhibition protects glioblastoma against cancer therapies; hence, BA treatment targeting this pathway can be considered as an effective therapeutic strategy to overcome such chemoresistance and tumor relapse.

BPR1M97, a dual mu opioid receptor/nociceptin-orphanin FQ peptide receptor agonist, produces potent antinociceptive effects with safer properties than morphine

There is unmet need to design an analgesic with fewer side effects for severe pain management. Although traditional opioids are the most effective painkillers, they are accompanied by severe adverse responses, such as respiratory depression, constipation symptoms, tolerance, withdrawal, and addiction. We indicated BPR1M97 as a dual mu opioid receptor (MOP)/nociceptin-orphanin FQ peptide (NOP) receptor full agonist and investigated the pharmacology of BPR1M97 in multiple animal models. In vitro studies on BPR1M97 were assessed using cyclic-adenosine monophosphate production, β-arrestin, internalization, and membrane potential assays. In vivo studies were characterized using the tail-flick, tail-clip, lung functional, heart functional, acetone drop, von Frey hair, charcoal meal, glass bead, locomotor activity, conditioned place preference (CPP) and naloxone precipitation tests. BPR1M97 elicited full agonist properties for all cell-based assays tested in MOP-expressing cells. However, it acted as a G protein-biased agonist for NOP. BPR1M97 initiated faster antinociceptive effects at 10 min after subcutaneous injection and elicited better analgesia in cancer-induced pain than morphine. Unlike morphine, BPR1M97 caused less respiratory, cardiovascular, and gastrointestinal dysfunction. In addition, BPR1M97 decreased global activity and induced less withdrawal jumping precipitated by naloxone. Thus, BPR1M97 could serve as a novel small molecule dual receptor agonist for antinociception with fewer side effects than morphine. This article is part of the Special Issue entitled 'New Vistas in Opioid Pharmacology'.

Convallatoxin enhance the ligand-induced mu-opioid receptor endocytosis and attenuate morphine antinociceptive tolerance in mice

Morphine is a unique opioid analgesic that activates the mu-opioid receptor (MOR) without efficiently promoting its endocytosis that may underlie side effects. Our objective was to discover a novel enhancer of ligand-induced MOR endocytosis and determine its effects on analgesia, tolerance and dependence. We used high-throughput screening to identify convallatoxin as an enhancer of ligand-induced MOR endocytosis with high potency and efficacy. Treatment of cells with convallatoxin enhanced morphine-induced MOR endocytosis through an adaptor protein 2 (AP2)/clathrin-dependent mechanism, attenuated morphine-induced phosphorylation of MOR, and diminished desensitization of membrane hyperpolarization. Furthermore, co-treatment with chronic convallatoxin reduced morphine tolerance in animal models of acute thermal pain and chronic inflammatory pain. Acute convallatoxin administration reversed morphine tolerance and dependence in morphine-tolerant mice. These findings suggest convallatoxin are potentially therapeutic for morphine side effects and open a new avenue to study MOR trafficking.

The in vivo antinociceptive and μ-opioid receptor activating effects of the combination of N-phenyl-2',4'-dimethyl-4,5'-bi-1,3-thiazol-2-amines and naloxone

Morphine is widely used for the treatment of severe pain. This analgesic effect is mediated principally by the activation of μ-opioid receptors (MOR). However, prolonged activation of MOR also results in tolerance, dependence, addiction, constipation, nausea, sedation, and respiratory depression. To address this problem, we sought alternative ways to activate MOR - either by use of novel ligands, or via a novel activation mechanism. To this end, a series of compounds were screened using a sensitive CHO-K1/MOR/Gα15 cell-based FLIPR^® calcium high-throughput screening (HTS) assay, and the bithiazole compound 5a was identified as being able activate MOR in combination with naloxone. Structural modifications of 5a resulted in the discovery of lead compound 5j, which could effectively activate MOR in combination with the MOR antagonist naloxone or naltrexone. In vivo, naloxone in combination with 100 mg/kg of compound 5j elicited antinociception in a mouse tail-flick model with an ED₅₀ of 17.5 ± 4 mg/kg. These results strongly suggest that the mechanism by which the 5j/naloxone combination activates MOR is worthy of further study, as its discovery has the potential to yield an entirely novel class of analgesics.

Upregulation of Znf179 acetylation by SAHA protects cells against oxidative stress

The accumulation of reactive oxygen species (ROS) commonly occurs during normal aging and during some acute/chronic progressive disorders. In order to avoid oxidative damage, scavenging of these radicals is important. Previously, we identified zinc finger protein 179 (Znf179) as a neuroprotector that increases antioxidant enzymes against superoxide radicals. However, the molecular mechanisms involved in the activation and regulation of Znf179 remain unresolved. Here, by performing sequence alignment, bioinformatics analysis, immunoprecipitation using two specific acetyl-lysine antibodies, and treatment with the histone deacetylase (HDAC) inhibitor SAHA, we determined the lysine-specific acetylation of Znf179. Furthermore, we investigated Znf179 interaction with HDACs and revealed that peroxide insult induced a dissociation of Znf179-HDAC1/HDAC6, causing an increase in Znf179 acetylation. Importantly, HDAC inhibition by SAHA further prompted Znf179 hyperacetylation, which promoted Znf179 to form a transcriptional complex with Sp1 and increased antioxidant gene expression against oxidative attack. In summary, the results obtained in this study showed that Znf179 was regulated by HDACs and that Znf179 acetylation was a critical mechanism in the induction of antioxidant defense systems. Additionally, HDAC inhibitors may have therapeutic potential for induction of Znf179 acetylation, strengthening the Znf179 protective functions against neurodegenerative processes.

Specificity protein 1-zinc finger protein 179 pathway is involved in the attenuation of oxidative stress following brain injury

After sudden traumatic brain injuries, secondary injuries may occur during the following days or weeks, which leads to the accumulation of reactive oxygen species (ROS). Since ROS exacerbate brain damage, it is important to protect neurons against their activity. Zinc finger protein 179 (Znf179) was shown to act as a neuroprotective factor, but the regulation of gene expression under oxidative stress remains unknown. In this study, we demonstrated an increase in Znf179 protein levels in both in vitro model of hydrogen peroxide (H₂O₂)-induced ROS accumulation and animal models of traumatic brain injury. Additionally, we examined the sub-cellular localization of Znf179, and demonstrated that oxidative stress increases Znf179 nuclear shuttling and its interaction with specificity protein 1 (Sp1). Subsequently, the positive autoregulation of Znf179 expression, which is Sp1-dependent, was further demonstrated using luciferase reporter assay and green fluorescent protein (GFP)-Znf179-expressing cells and transgenic mice. The upregulation of Sp1 transcriptional activity induced by the treatment with nerve growth factor (NGF) led to an increase in Znf179 levels, which further protected cells against H₂O₂-induced damage. However, Sp1 inhibitor, mithramycin A, was shown to inhibit NGF effects, leading to a decrease in Znf179 expression and lower cellular protection. In conclusion, the results obtained in this study show that Znf179 autoregulation through Sp1-dependent mechanism plays an important role in neuroprotection, and NGF-induced Sp1 signaling may help attenuate more extensive (ROS-induced) damage following brain injury.

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Znf179 levels increase in vitro after hydrogen peroxide treatment.

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Znf179 levels increase in vivo in traumatic brain injury mouse model.

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Oxidative stress increases Znf179 translocation to nucleus.

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Znf179 autoregulates its expression through Sp1-dependent mechanism.

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Sp1-Znf179 pathway plays an important role in neuroprotection.

Suberoylanilide hydroxamic acid represses glioma stem-like cells

Background

Glioma stem-like cells (GSCs) are proposed to be responsible for high resistance in glioblastoma multiforme (GBM) treatment. In order to find new strategies aimed at reducing GSC stemness and improving GBM patient survival, we investigated the effects and mechanism of a histone deacetylases (HDACs) inhibitor, suberoylanilide hydroxamic acid (SAHA), since HDAC activity has been linked to cancer stem-like cell (CSC) abundance and properties.

Methods

Human GBM cell lines were plated in serum-free suspension cultures allowed for sphere forming and CSC enrichment. Subsequently, upon SAHA treatment, the stemness markers, cell proliferation, and viability of GSCs as well as cellular apoptosis and senescence were examined in order to clarify whether inhibition of GSCs occurs.

Results

We demonstrated that SAHA attenuated cell proliferation and diminished the expression stemness-related markers (CD133 and Bmi1) in GSCs. Furthermore, at high concentrations (more than 5 μM), SAHA triggered apoptosis of GSCs accompanied by increases in both activation of caspase 8- and caspase 9-mediated pathways. Interestingly, we found that a lower dose of SAHA (1 μM and 2.5 μM) inhibited GSCs via cell cycle arrest and induced premature senescence through p53 up-regulation and p38 activation.

Conclusion

SAHA induces apoptosis and functions as a potent modulator of senescence via the p38-p53 pathway in GSCs. Our results provide a perspective on targeting GSCs via SAHA treatment, and suggest that SAHA could be used as a potent agent to overcome drug resistance in GBM patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-016-0296-6) contains supplementary material, which is available to authorized users.

Discovery, structure-activity relationship studies, and anti-nociceptive effects of N-(1,2,3,4-tetrahydro-1-isoquinolinylmethyl)benzamides as novel opioid receptor agonists

μ-Opioid receptor (MOR) agonists are analgesics used clinically for the treatment of moderate to severe pain, but their use is associated with severe adverse effects such as respiratory depression, constipation, tolerance, dependence, and rewarding effects. In this study, we identified N-({2-[(4-bromo-2-trifluoromethoxyphenyl)sulfonyl]-1,2,3,4-tetrahydro-1-isoquinolinyl}methyl)cyclohexanecarboxamide (1) as a novel opioid receptor agonist by high-throughput screening. Structural modifications made to 1 to improve potency and blood-brain-barrier (BBB) penetration resulted in compounds 45 and 46. Compound 45 was a potent MOR/KOR (κ-opioid receptor) agonist, and compound 46 was a potent MOR and medium KOR agonist. Both 45 and 46 demonstrated a significant anti-nociceptive effect in a tail-flick test performed in wild type (WT) B6 mice. The ED₅₀ value of 46 was 1.059 mg/kg, and the brain concentrations of 45 and 46 were 7424 and 11696 ng/g, respectively. Accordingly, compounds 45 and 46 are proposed for lead optimization and in vivo disease-related pain studies.

The sigma-1 receptor-zinc finger protein 179 pathway protects against hydrogen peroxide-induced cell injury

The accumulation of reactive oxygen species (ROS) have implicated the pathogenesis of several human diseases including neurodegenerative disorders, stroke, and traumatic brain injury, hence protecting neurons against ROS is very important. In this study, we focused on sigma-1 receptor (Sig-1R), a chaperone at endoplasmic reticulum, and investigated its protective functions. Using hydrogen peroxide (H2O2)-induced ROS accumulation model, we verified that apoptosis-signaling pathways were elicited by H2O2 treatment. However, the Sig-1R agonists, dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS), reduced the activation of apoptotic pathways significantly. By performing protein-protein interaction assays and shRNA knockdown of Sig-1R, we identified the brain Zinc finger protein 179 (Znf179) as a downstream target of Sig-1R regulation. The neuroprotective effect of Znf179 overexpression was similar to that of DHEAS treatment, and likely mediated by affecting the levels of antioxidant enzymes. We also quantified the levels of peroxiredoxin 3 (Prx3) and superoxide dismutase 2 (SOD2) in the hippocampi of wild-type and Znf179 knockout mice, and found both enzymes to be reduced in the knockout versus the wild-type mice. In summary, these results reveal that Znf179 plays a novel role in neuroprotection, and Sig-1R agonists may be therapeutic candidates to prevent ROS-induced damage in neurodegenerative and neurotraumatic diseases.

Identification of Substituted Naphthotriazolediones as Novel Tryptophan 2,3-Dioxygenase (TDO) Inhibitors through Structure-Based Virtual Screening

A structure-based virtual screening strategy, comprising homology modeling, ligand-support binding site optimization, virtual screening, and structure clustering analysis, was developed and used to identify novel tryptophan 2,3-dioxygenase (TDO) inhibitors. Compound 1 (IC50 = 711 nM), selected by virtual screening, showed inhibitory activity toward TDO and was subjected to structural modifications and molecular docking studies. This resulted in the identification of a potent TDO selective inhibitor (11e, IC50 = 30 nM), making it a potential compound for further investigation as a cancer therapeutic and other TDO-related targeted therapy.

Morphine drives internal ribosome entry site-mediated hnRNP K translation in neurons through opioid receptor-dependent signaling

Heterogeneous nuclear ribonucleoprotein K (hnRNP K) binds to the promoter region of mu-opioid receptor (MOR) to regulate its transcriptional activity. How hnRNP K contributes to the analgesic effects of morphine, however, is largely unknown. We provide evidence that morphine increases hnRNP K protein expression via MOR activation in rat primary cortical neurons and HEK-293 cells expressing MORs, without increasing mRNA levels. Using the bicistronic reporter assay, we examined whether morphine-mediated accumulation of hnRNP K resulted from translational control. We identified potential internal ribosome entry site elements located in the 5′ untranslated regions of hnRNP K transcripts that were regulated by morphine. This finding suggests that internal translation contributes to the morphine-induced accumulation of hnRNP K protein in regions of the central nervous system correlated with nociceptive and antinociceptive modulatory systems in mice. Finally, we found that down-regulation of hnRNP K mediated by siRNA attenuated morphine-induced hyperpolarization of membrane potential in AtT20 cells. Silencing hnRNP K expression in the spinal cord increased nociceptive sensitivity in wild-type mice, but not in MOR-knockout mice. Thus, our findings identify the role of translational control of hnRNP K in morphine-induced analgesia through activation of MOR.

58-kDa microspherule protein (MSP58) is novel Brahma-related gene 1 (BRG1)-associated protein that modulates p53/p21 senescence pathway

The nucleolar 58-kDa microspherule protein (MSP58) protein is a candidate oncogene implicated in modulating cellular proliferation and malignant transformation. In this study, we show that knocking down MSP58 expression caused aneuploidy and led to apoptosis, whereas ectopic expression of MSP58 regulated cell proliferation in a context-dependent manner. Specifically, ectopic expression of MSP58 in normal human IMR90 and Hs68 diploid fibroblasts, the H184B5F5/M10 mammary epithelial cell line, HT1080 fibrosarcoma cells, primary mouse embryonic fibroblasts, and immortalized NIH3T3 fibroblasts resulted in induction of premature senescence, an enlarged and flattened cellular morphology, and increased senescence-associated β-galactosidase activity. MSP58-driven senescence was strictly dependent on the presence of functional p53 as revealed by the fact that normal cells with p53 knockdown by specific shRNA or cells with a mutated or functionally impaired p53 pathway were effective in bypassing MSP58-induced senescence. At least two senescence mechanisms are induced by MSP58. First, MSP58 activates the DNA damage response and p53/p21 signaling pathways. Second, MSP58, p53, and the SWI/SNF chromatin-remodeling subunit Brahma-related gene 1 (BRG1) form a ternary complex on the p21 promoter and collaborate to activate p21. Additionally, MSP58 protein levels increased in cells undergoing replicative senescence and stress-induced senescence. Notably, the results of analyzing expression levels of MSP58 between tumors and matched normal tissues showed significant changes (both up- and down-regulation) in its expression in various types of tumors. Our findings highlight new aspects of MSP58 in modulating cellular senescence and suggest that MSP58 has both oncogenic and tumor-suppressive properties.

Selective inhibition of early--but not late--expressed HIF-1α is neuroprotective in rats after focal ischemic brain damage

The expression of hypoxia-inducible factor-1-alpha (HIF-1α) is upregulated in ischemic stroke, but its function is still unclear. In the present study, biphasic expression of HIF-1α was observed during 1-12 h and after 48 h in neurons exposed to ischemic stress in vitro and in vivo. Treating neurons with 2-methoxyestradiol (2ME2) 0.5 h after ischemic stress or pre-silencing HIF-1α with small interfering RNA (siRNA) decreased brain injury, brain edema and number of apoptotic cell, and downregulates Nip-like protein X (Nix) expression. Conversely, applying 2ME2 to neurons 8 h after ischemic stress or silencing the HIF-1α with siRNA 12 h after oxygen-glucose deprivation (OGD) increased neuron damage and decreased vascular endothelial growth factor (VEGF) expression. Taken together, these results demonstrate that HIF-1α induced by ischemia in early and late times leads cellular apoptosis and survival, respectively, and provides a new insight into the divergent roles of HIF-1α expression in neurons after ischemic stroke.

Late expression of brain-derived neurotrophic factor in the amygdala is required for persistence of fear memory

In many instances, increase in neuronal activity can induce biphasic secretion of a modulator. The initial release of the modulator triggers the induction of synaptic plasticity, whereas the second-phase release reinforces the efficacy of synaptic transmission and growth of dendrites and axons. In this study, we showed that fear conditioning not only induced the first but also a second peak of brain-derived neurotrophic factor (BDNF) expression. Fluorescent immunohistostaining confirmed that BDNF expression increased at 1 and 12 h after conditioning and returned to baseline at 30 h after conditioning. Mature BDNF expression increased in a similar manner. TrkB-IgG or K252a infusion before training impaired fear memory on days 1 and 7 after training. In contrast, TrkB-IgG or K252a infusion 9 h after fear conditioning did not affect memory retention on day 1 after training but impaired fear memory on day 7 after training. Fear conditioning significantly enhanced Zif268 expression in the amygdala at 12 h after training; this enhanced expression was completely inhibited by TrkB-IgG infusion 9 h after training. The level of growth-associated protein 43 (GAP-43), a marker of newly formed synapses, in the amygdala increased 7 days after fear conditioning. Moreover, conditioned rats had higher AMPA/NMDA ratio than unpaired rats. These results suggest that consolidated memory could be continuously modulated by previous molecular changes produced during memory acquisition.

Heat shock protein 90 is important for Sp1 stability during mitosis

Our previous study has revealed that heat shock protein (Hsp) 90 can interact with Sp1 to regulate the transcriptional activity of 12(S)-lipoxygenase. Herein, we further found that the interaction between Hsp90 and Sp1 occurred during mitosis. By geldanamycin (GA) treatment and knockdown of Hsp90, we found that this interaction during mitosis was involved in the maintenance of Sp1 stability, and that the phospho-c-Jun N-terminal kinase (JNK)-1 level also decreased. As the JNK-1 was knocked down by the shRNA of JNK-1, Sp1 was degraded through a ubiquitin-dependent proteasome pathway. In addition, for mutation of the JNK-1 phosphorylated residues of Sp1, namely, Sp1(T278/739A) and Sp1(T278/739D), the effect of GA on Sp1 stability was reversed. Finally, based on the involvement of Hsp90 in Sp1 stability, the transcriptional activities of p21(WAF1/CIP1) and 12(S)-lipoxygenase under GA treatment were observed to have decreased. Taken together, Hsp90 is important for maintaining Sp1 stability during mitosis by the JNK-1-mediated phosphorylation of Sp1 to enable division into daughter cells and to regulate the expression of related genes in the interphase.

Phosphorylation by c-Jun NH2-terminal kinase 1 regulates the stability of transcription factor Sp1 during mitosis

The transcription factor Sp1 is ubiquitously expressed in different cells and thereby regulates the expression of genes involved in many cellular processes. This study reveals that Sp1 was phosphorylated during the mitotic stage in three epithelial tumor cell lines and one glioma cell line. By using different kinase inhibitors, we found that during mitosis in HeLa cells, the c-Jun NH(2)-terminal kinase (JNK) 1 was activated that was then required for the phosphorylation of Sp1. In addition, blockade of the Sp1 phosphorylation via inhibition JNK1 activity in mitosis resulted in the ubiquitination and degradation of Sp1. JNK1 phosphorylated Sp1 at Thr278/739. The Sp1 mutated at Thr278/739 was unstable during mitosis, possessing less transcriptional activity for the 12(S)-lipoxygenase expression and exhibiting a decreased cell growth rate compared with wild-type Sp1 in HeLa cells. In N-methyl-N-nitrosourea-induced mammary tumors, JNK1 activation provided a potential relevance with the accumulation of Sp1. Together, our results indicate that JNK1 activation is necessary to phosphorylate Sp1 and to shield Sp1 from the ubiquitin-dependent degradation pathway during mitosis in tumor cell lines.

Synaptic Expression of Glutamate Receptor after Encoding of Fear Memory in the Rat Amygdala

Fear conditioning has been ascribed to presynaptic mechanisms, particularly presynaptic facilitation of transmission at thalamo- and cortico-amygdala synapses. Here, by labeling surface receptors with biotin or using membrane fractionation approaches, we report that fear conditioning resulted in an increase in surface expression of GluR1 subunit of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors in the amygdala, whereas total GluR1 mRNA and protein levels were unchanged. The control group that received conditioned stimulus (CS) and unconditioned stimulus in an unpaired fashion did not present any increase, indicating that GluR1 increase was specific to the learning component of the task. Conditioning-induced increase in surface expression of GluR1 depended on the activation of N-methyl-d-aspartate receptors and protein kinases and required the synthesis of new proteins. CS-alone trials applied 24 h before training attenuated fear-potentiated startle and prevented conditioning-induced increase in surface expression of GluR1. Increase in GluR1 was also observed in the amygdala slices after delivery of tetanic stimulation that elicited long-term potentiation of synaptic transmission. Proteasome inhibitor increased surface expression of GluR1 in a time- and dose-dependent manner. Furthermore, pretraining administration of proteasome inhibitor into the amygdala facilitated the fear-potentiated startle. These results suggest that long-term memory formation is correlated with the change in synaptic expression of GluR1, and trafficking of GluR1 to the synaptic sites contributes at least in part to the expression of fear memory.

Acetylation of nuclear factor-kappaB in rat amygdala improves long-term but not short-term retention of fear memory

Memory consolidation is mediated by new protein synthesis. However, the transcriptional pathways induced in neurons by behavioral training that activate gene responses have yet to be fully delineated. We have previously shown that nuclear factor kappaB (NF-kappaB) is activated in the amygdala after fear conditioning. Here we report that fear conditioning resulted in an increase in histone acetyl-transferase activity, the association between NF-kappaB p65 and CBP, and the increase in acetylated p65. Pretreating animals with histone deacetylase (HDAC) inhibitors prolonged the nuclear expression of acetyl-p65 and increased its DNA binding activity. Consistent with these results, HDAC inhibitors enhanced long-term but not short-term fear memory, and this effect was attenuated by kappaB decoy DNA, whereas scrambled DNA was without effect. This study provides evidence that HDAC-mediated deacetylation functions as an intranuclear molecular switch culminating in the termination of NF-kappaB transcriptional response that is involved in the formation of fear memory.

The similarities and diversities of signal pathways leading to consolidation of conditioning and consolidation of extinction of fear memory

It is generally believed that consolidation of long-term memory requires activation of protein kinases, transcription of genes, and new protein synthesis. However, little is known about the signal cascades involved in the extinction of memory, which occurs when the conditioned stimulus is no longer followed by the unconditioned stimulus. Here, we show for the first time that an intra-amygdala injection of transcription inhibitor actinomycin D at the dose that blocked acquisition failed to affect extinction of a learned response. Conversely, protein synthesis inhibitor anisomycin blocked both acquisition and extinction. Extinction training-induced expression of calcineurin was blocked by anisomycin but not by actinomycin D. NMDA receptor antagonist, phosphatidylinositol 3-kinase (PI-3 kinase), and MAP kinase inhibitors that blocked the acquisition also blocked the extinction of conditioned fear. Likewise, PI-3 kinase inhibitor blocked fear training-induced cAMP response element-binding protein (CREB) phosphorylation as well as extinction training-induced decrease in CREB phosphorylation, the latter of which was associated with calcineurin expression and could be reversed by a specific calcineurin inhibitor. Thus, molecular processes that underlie long-term behavioral changes after acquisition and extinction share some common mechanisms and also display different characteristics.

Identification of calcineurin as a key signal in the extinction of fear memory

Memory extinction refers to a gradual decrease of the previously acquired response when exposed to conditional stimulus without pairing with unconditional stimulus. Here we show for the first time that fear training-induced phosphorylation of specific substrates in the rat amygdala is reduced after extinction trials and is accompanied by an increase in the protein level and enzymatic activity of calcineurin. In parallel, calcineurin inhibitors prevented extinction-induced protein dephosphorylation as well as extinction of fear memory. Thus, extinction training increased phosphatase activity likely via an expression of calcineurin. Calcineurin then created a negative-feedback loop and directly or indirectly dephosphorylated specific substrates, which, in their phosphorylated state, were required for memory consolidation. Accordingly, in our experimental condition, extinction could be ascribed at least in part to a weakening of the original signaling.

The measurement of 60Co contaminated rebar buildings with thermoluminescence dosemeters

Three contaminated housing units, yielding annual dose levels of 6, 22 and 57 mSv, were selected randomly from identified radiation contaminated buildings (RCBs) to perform this experiment. The results are presented of a study to investigate the probability of finding RCBs by using eight thermoluminescence dosemeters (TLDs) for each suspected radiation contaminated housing unit. The results revealed that, for these three housing units, the probabilities of detecting contaminated housing units using eight TLDs were 93%, 86% and 99%, respectively. The number of TLDs required for such a determination depended strongly on both the radiation contaminated level (i.e., the activity) in the housing unit and the distribution of contaminated columns and beams in the house.

A requirement of nuclear factor-kappaB activation in fear-potentiated startle

Previous studies have shown that biochemical changes that occur in the amygdala during fear conditioning in vivo are similar to those occur during long term potentiation (LTP) in vitro. Electrophoretic mobility shift assay of nuclear extracts from startle-potentiated rats showed a selective increase in the amygdala of nuclear factor-kappaB (NF-kappaB) DNA binding activity. Supershift experiments further indicated that p65 and p50 subunits but not c-Rel were involved in DNA binding. The protein levels of IkappaB-alpha were reduced by treatments that reliably induced LTP in this area of the brain. This was accompanied by a decrease of NF-kappaB in the cytoplasm concomitant with an increase in the nucleus. Quantitative analysis of IkappaB kinase activity demonstrated that fear training led to an increase in kinase activity, and this effect was inhibited by thalidomide. Paralleled behavioral tests revealed that thalidomide inhibited fear-potentiated startle. Intra-amygdala administration of kappaB decoy DNA prior to training impaired fear-potentiated startle as well as LTP induction. Similarly, NF-kappaB inhibitors blocked IkappaB-alpha degradation and startle response. These results provide the first evidence of a requirement of NF-kappaB activation in the amygdala for consolidation of fear memory.

Strategies for development of combination vaccines

BACKGROUND

The increasing complexity of the recommended childhood immunization schedule has resulted in the need for combination vaccines.

METHODS

Through an extensive review of the current literature, various strategies and issues related to the development of combination vaccines are discussed.

RESULTS

Issues that should be considered when combining vaccine components include the current childhood immunization schedule, compatibility of components, availability of antigens for targeted diseases, safety, efficacy, immunogenicity and route of delivery. When choosing an appropriate combination of antigen(s)/serotype(s) for a global or national formulation, careful consideration must be made when selecting serotypes to combine depending on the market or area of use. It is important to know that potential interactions can involve other components of the vaccines, including buffers, adjuvants and preservatives. The Food and Drug Administration requires that the combination not only have immunogenicity comparable with those of the component vaccines, but that its safety profile be comparable with the most reactogenic component. The Food and Drug Administration also recommends that a test of noninferiority be performed, such that the combination performs similarly to the separate components with regard to antibody titers.

CONCLUSIONS

Combination vaccines are critical to the success of vaccination programs, and each new combination must be carefully studied to ensure comparable safety and immunogenicity of the individual components.

Safety and immunogenicity of a pentavalent diphtheria, tetanus, pertussis, hepatitis B and polio combination vaccine in infants

INTRODUCTION

The objectives of this study were to evaluate the safety and immunogenicity of a new combination vaccine (DTaP-HB-IPV) containing diphtheria, tetanus, acellular pertussis and hepatitis B (HB) and a new inactivated poliovirus vaccine (IPV) manufactured by GlaxoSmithKline (GSK). This vaccine was given in an all IPV or sequential IPV and oral polio vaccine (OPV) schedule. Another combination vaccine, DTaP-HB (GSK), was similarly evaluated given with OPV or IPV.

METHODS

Four hundred infants were randomized into one of four study groups and immunized at 2, 4 and 6 months of age. Group A received three doses of DTaP-HB-IPV; Group B received DTaP-HB-IPV at 2 and 4 months and DTaP-HB with OPV (Orimune) at 6 months; Group C received three doses of DTaP-HB with licensed IPV (IPOL) administered separately; Group D received separate doses of OPV, DTaP (Infanrix; GSK) and HB (Engerix; GSK). All subjects received conjugate Haemophilus influenzae type b vaccine (Hib) (OmniHIB) at 2, 4 and 6 months of age given at a separate injection site. Subjects who returned at 12 to 18 months of age (229) received booster immunization with DTaP and Hib. Safety was evaluated after each vaccine dose. Blood was drawn before the first dose and one month after the third dose as well as before and after the booster dose.

RESULTS

There were no vaccine-related serious adverse events in any group after any vaccine dose. Minor systemic and local adverse events were also not significantly different among the four groups after any dose. There were no differences in the immune response rates for Hib, HB, polio (types 1, 2 and 3), diphtheria, tetanus or pertussis antigens (pertussis toxin, filamentous hemagglutinin, pertactin) among groups, although there were some quantitative differences in specific antibody titers among groups. DTaP-HB-IPV and DTaP-HB combination vaccines had safety and immunogenicity equivalent to those of standard individually administered vaccines. The new IPV was not inferior to IPOL.

CONCLUSION

Use of the pentavalent combination vaccine would greatly reduce the number of required injections during the first 2 years of life, thereby simplifying the immunization schedule, enhancing compliance and facilitating acceptance of additional injections engendered by introduction of newer vaccines.

Antibody responses to bovine parainfluenza virus type 3 (PIV3) vaccination and human PIV3 infection in young infants

A phase 2 clinical trial was conducted to evaluate the antibody responses to bovine parainfluenza virus type 3 (bPIV3) vaccination in young infants. Three groups were tested as follows: placebo (n=66) and 10(5) (n=64) or 10(6) (n=62) TCID(50) of bPIV3. The vaccine or placebo was administered intranasally at ages 2, 4, 6, and 12-15 months, and serum specimens were collected at ages 2, 6, 7, 12-15, and 13-16 months. Serum hemagglutination inhibition (HI) and IgA antibody titers against bPIV3 and human PIV3 (hPIV3) were measured. The results indicate that antibody responses to bPIV3 vaccination are more likely to be detected by the bPIV3 IgA and HI assays than by the hPIV3 IgA and HI assays, that bPIV3-induced antibody response can be differentiated from hPIV3-induced antibody response most reliably by comparing bPIV3 and hPIV3 HI titers, and that bPIV3 vaccine prevents vaccine recipients from developing antibody profiles of hPIV3 primary infection.

A role for the PI-3 kinase signaling pathway in fear conditioning and synaptic plasticity in the amygdala

Western blot analysis of neuronal tissues taken from fear-conditioned rats showed a selective activation of phosphatidylinositol 3-kinase (PI-3 kinase) in the amygdala. PI-3 kinase was also activated in response to long-term potentiation (LTP)-inducing tetanic stimulation. PI-3 kinase inhibitors blocked tetanus-induced LTP as well as PI-3 kinase activation. In parallel, these inhibitors interfered with long-term fear memory while leaving short-term memory intact. Tetanus and forskolin-induced activation of mitogen-activated protein kinase (MAPK) was blocked by PI-3 kinase inhibitors, which also inhibited cAMP response element binding protein (CREB) phosphorylation. These results provide novel evidence of a requirement of PI-3 kinase activation in the amygdala for synaptic plasticity and memory consolidation, and this activation may occur at a point upstream of MAPK activation.

Chromosomal allelic imbalance evolving from liver cirrhosis to hepatocellular carcinoma

BACKGROUND & AIMS

Cirrhotic nodules have long been assumed to be the precancerous lesions of hepatocellular carcinoma (HCC). We thus investigated the allelic imbalance (AI) in cirrhotic nodules to define the genetic aberrations in early hepatocarcinogenesis.

METHODS

One hundred eighty cirrhotic nodules from 7 female patients with HCC were collected by microdissection. Their clonality nature was assessed by examining the X chromosome methylation pattern. AI in monoclonal cirrhotic nodules and the corresponding HCCs were analyzed with microsatellite polymorphic markers.

RESULTS

One hundred one out of 180 nodules (56.1%) were monoclonal and the average fractional AI (FAI) was 21%, lower than the 40% in HCC. Their overall AI patterns differed significantly from that in HCC (P < 0.001) with FAI on 2q, 4q, 8p, and Xq higher than the mean value. Comparison of FAI in nodules (stratified by increasing total AI events) further revealed a progressive increase of FAI on 4q, 8p, and Xq. In contrast, FAI on 1p, 13q, 16q, and 17p were low in nodules but rose above the mean only in HCC.

CONCLUSIONS

About half of the cirrhotic nodules are monoclonal and already have chromosome aberrations. AI on 4q, 8p, and Xq may be the earlier mutations, whereas AI on 1p, 13q, 16q, and 17p occurs late in hepatocarcinogenesis.

[Continuing education needs & knowledge of gerontological nursing among nurses in nursing homes]

The purpose of this study was to explore continuing education needs and knowledge of gerontological nursing among nurses in nursing homes, and analyze the relationship of demographic characteristics, knowledge and continuing education needs. Twenty nursing homes were randomly selected and 130 nurses were interviewed by structured questionnaires to ascertain their demographic characteristics, knowledge of gerontological nursing, and continuing education needs. Results showed that more than half of the nurses had not attended any courses in gerontological nursing in school, or in post-graduate continuing education. The rate of correct answers for knowledge of gerontological nursing was 70.8%. The worst knowledge was of gerontological statistics, followed by physical and psychological aspects of aging. Knowledge levels in gerontological nursing were positively correlated with age (r = .22, p < .05) having taken gerontological nursing courses (r =.22, p < .05) and having taken continuing education in gerontological nursing (r = .18, p < .05). Knowledge levels were negatively correlated with having lived with the elders in their own family (r = -.30, p < .05). Nurses who graduated from junior college or nursing high school had lower scores for knowledge than college graduates (F = 25.31, p < .001). The intensity level of continuing education needs ranged from needed to strongly needed, especially for knowledge regarding clinical care, followed by general information on aging, and administration and management. The level of continuing education needs was not different among the various demographic characteristics and knowledge levels in gerontological nursing. Results from this study suggest that gerontological nursing courses should be increased in nursing schools. Furthermore, a well-formulated continuing education model for gerontological nurses in nursing homes is also essential to promote the quality of care of the elderly.

[The outcomes of restraint reduction program in nursing homes]

One of the problems in nursing home care in Taiwan is resident restraint, including physical and chemical restraints. This pre-experimental study was conducted to investigate whether a restraint reduction program could reduce the prevalence of restraint in nursing homes. Three registered nursing homes were randomly selected from nursing homes in the Kaohsiung area. Staff and residents of these nursing homes were educated in restraint alternatives, balance training and managing behavior problems in one month of interventions. Three days before and after interventions, prevalence of restraints, falls, and of pressure sores, balance reaction, frequency of agitation, use of psychotic drugs, as well as the restraint knowledge of the nursing staff, was measured. After the restraint reduction program, the prevalence of restraint and frequency of resident agitation decreased significantly. The prevalence of falls and pressure sores of residents was not changed significantly. The restraint knowledge of the nursing staff significantly increased after the restraint reduction program. The information from this study led to a better strategy to reduce restraint for the elderly in nursing homes. The results could also provide a model to improve the quality of care in nursing homes in Taiwan.

Prolonged and enhanced suppression of thymidylate synthase by weekly 24-h infusion of high-dose 5-fluorouracil

We have recently demonstrated that HDFL (high-dose 5-FU 2600 mg m-2 week-1 and leucovorin 500 mg m-2 week-1, weekly 24-h infusion) is highly active in the treatment of gastric cancer. To further clarify the possible mechanism underlying the improved activity of HDFL compared with conventional 5-FU regimens, we conducted in vitro studies examining the effect of these regimens on the differential regulation of thymidylate synthase (TS) in NCI-N87, a human gastric cancer cell line. The expected serum concentrations of 5-FU are 100-200 mM (lasting for less than 30 min) and 5-10 mM (lasting for 24 h) for the conventional 5-FU regimens (bolus injection or short intravenous infusion of 5-FU 370-500 mg m-2) and the HDFL regimens, respectively. Western blot analysis revealed that 24-h exposure of NCI-N87 to 2.5-10.0 mM of 5-FU resulted in a dose-dependent depletion of free TS, lasting for more than 24 h. In contrast, 30-min exposure of NCI-N87 to 200 mM of 5-FU resulted in a less than 12-h depletion of free TS. Moreover, 24-h exposure to 5-FU resulted in a higher S-phase blockade and enhanced cytotoxicity. In both modes of 5-FU treatment, the initial rapid depletion of free TS was accompanied by a rapid increment of a higher-molecular-weight TS molecule, suggesting that rapid formation of the ternary complex was the key mechanism of 5-FU action during this period. Northern blot analysis showed that the steady-state mRNA of TS was not affected by either of the schedules. We conclude that 24-h exposure of gastric cancer cells to low concentration of 5-FU resulted in better suppression of free TS, a higher degree of S-phase blockade, and enhanced cytotoxicity compared to 30-min exposure to high concentration of 5-FU. These in vitro results may help explain the improved clinical efficacy of HDFL regimens compared to conventional 5-FU regimens.

Chromosomal changes and clonality relationship between primary and recurrent hepatocellular carcinoma

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is highly malignant and prone to recur after surgical treatment. Differentiation between a true relapse of HCC and a second primary tumor is of clinical importance. However, no convenient method is currently available.

METHODS

Comparative genomic hybridization (CGH) was used to analyze 31 pairs of initial and recurrent HCC samples obtained from patients undergoing 2 consecutive surgeries. The resulting chromosomal aberration profiles were used as genomic fingerprints to determine tumor clonalities and their relationships.

RESULTS

Eleven recurrent tumors with high clonal relationship (CR) values (>0.95) were found to be relapsed HCCs, and 11 tumors with CR values close to 0 were found to be second primary HCCs. The other 9 paired samples had inconclusive CR values between 0.95 and 0.4. Two were confirmed by hepatitis B virus integration and X chromosome inactivation analysis to be de novo cancers (CR values, 0.35 and 0. 23, respectively). Initial HCCs that subsequently relapsed accumulated more chromosomal aberration events than those that developed de novo HCC (mean, 16.1 +/- 4.5 vs. 5.4 +/- 4.8 events; P < 0.01). Also, they more frequently showed gains on chromosome arms 3q, 6p, 8q, and 17q and losses on 4q and 16p.

CONCLUSIONS

CGH is useful for chromosomal aberration study and tumor clonality analysis. More and characteristic genomic changes in the initial HCC suggest that subsequent tumor recurrence is a true relapse.

Parapharyngeal abscess due to cat-scratch disease

The spectrum of illness attributed to cat-scratch disease (CSD) continues to expand. Although a common cause of cervical adenitis in children, CSD has not been associated as a cause of deep fascial space infections of the head and neck. We describe a child with extensive parapharyngeal adenitis and abscesses due to CSD confirmed by histological and serological evaluations.

Minimal toxicity to myeloid progenitor cells of weekly 24-hr infusion of high-dose 5-fluorouracil: direct evidence from colony forming unit-granulocyte and monocyte (CFU-GM) clonogenic assay

Although very high doses of 5-fluorouracil was used in the weekly 24-h infusion, high-dose 5-fluorouracil (2600 mg/m2/week) and leucovorin (500 mg/m2/week) protocol, myelosuppression was surprisingly low. The current study was conducted to investigate the possible mechanism underlying the low myelosuppression. To mimic the clinical situation, peripheral blood progenitor cells collected from 12 patients were used for colony forming unit-granulocyte and monocyte clonogenic assay; and 2 representative modes of 5-fluorouracil exposure (30 min. versus 24 hr) were examined for cytotoxic effects on human myeloid progenitor cells. Previous pharmacokinetic studies have estimated the concentrations of 5-fluorouracil in the bone marrow to be 200-400 microM and 1-2 microM for the 30 min. infusion (600-900 mg/m2) and the 24 hr-infusion (1000-2000 mg/m2) regimens, respectively. The results of our colony-forming unit-granulocyte and monocyte clonogenic assay showed that 24-hr exposure to 5-fluorouracil (2 microM) and 30 min. exposure to 5-fluorouracil (100 microM) resulted in 27.2% and 78.2% inhibition of the colony formation, respectively. Our data provided direct evidence which may explain why myelotoxicity is significantly less in weekly 24 hr infusion of fluorouracil than in the conventional bolus regimens.

Gene therapy with tumor vaccine increases the survival of hepatoma-bearing mice

BACKGROUND

Tumor vaccines combined with cytokine gene therapy and Bacillus Calmette-Guérin (BCG) were tested for prevention and therapeutic effects in the H6 mouse hepatoma model.

METHODS

Plasmid DNA of expression vectors carrying cDNA of mouse interleukin (IL)-2 and mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) were used for transfection to obtain H6 mouse hepatoma cells that secreted IL-2 (H6/IL-2) or GM-CSF (H6/GM-CSF). For tumor prevention, groups of mice were immunized twice with irradiated tumor cells with untransduced H6, H6/IL-2, H6/GM-CSF, or an equal mixture of H6/IL-2 and H6/GM-CSF. Three weeks later, these mice were inoculated subcutaneously with live H6 hepatoma cells, and tumor growth was measured. For therapeutic studies, mice first inoculated with live H6 cells were treated three days later with various irradiated tumor cell vaccines alone or in combination with BCG. Subsequent tumor growth was measured.

RESULTS

In tumor prevention studies, significant protection from tumor growth has been observed in animals vaccinated with irradiated cytokine-secreting H6 cells compared with those immunized with irradiated parental H6 cells. In tumor therapy studies, subsequent administration of irradiated H6/GM-CSF cells in combination with BCG impeded the tumorigenicity of preinoculated live H6 hepatoma cells.

CONCLUSIONS

These results suggest that cytokine-secreting tumor vaccines have a prophylactic effect and BCG, in combination with irradiated H6/GM-CSF cells, shows a synergistic effect on delaying the growth of H6 mouse hepatomas.

Whole-body PET with (fluorine-18)-2-deoxyglucose for detecting recurrent ovarian carcinoma. Initial report

OBJECTIVE

To investigate positron emission tomography (PET) with (fluorine-18)-2-deoxyglucose (FDG) for detecting recurrent ovarian carcinoma.

STUDY DESIGN

Wholebody FDG-PET scanning was performed on five patients before surgical exploration. All five patients were suspected of having recurrence based upon clinical findings and underwent surgery after scanning.

RESULTS

In all five patients, PET images demonstrated increased FDG uptake in a distribution that correlated with surgical-pathologic findings (100%); computer tomography can detect 60% of such patients with malignant disease. Two cases with unexplained elevated serum CA-125 had lesions localized by PET.

CONCLUSION

Recurrence of ovarian carcinoma was clearly imaged with FDG-PET and was confirmed by surgical pathology. FDG-PET might be a fairly effective tool for detecting recurrent ovarian carcinoma.

11C-acetate clearance in nasopharyngeal carcinoma

This study assessed 11C-acetate turnover (clearance) in nasopharyngeal carcinoma (NPC). Data were acquired by dynamic PET after the intravenous injection of 4.625 MBq.kg-1 body weight of 11C-acetate for 30 min. Tomograms were reconstructed and evaluated visually. A time-activity curve of the nasopharynx and neck was generated and the clearance rate of 11C-acetate from the nasopharynx in the slow phase and from NPC was calculated using 0.693/T1/2. Ten patients with nasopharyngeal carcinoma and nine normal subjects were studied. The clearance of 11C-acetate from the normal nasopharynx was rapid and biexponential, in contrast to the rapid uptake followed by extremely slow clearance in patients with NPC. The clearance rate (mean +/- S.D.) was 0.0074 +/- 0.0042 in NPC and 0.0263 +/- 0.0152 in controls in the slow phase, being significantly different between the two groups with no overlap. All nasopharyngeal carcinomas were clearly visualized, in contrast to no obvious retention in the normal nasopharynx. Our initial results indicate that 11C-acetate clearance can be used to differentiate nasopharyngeal carcinoma from a normal nasopharynx. This finding may lead to new applications of 11C-acetate in oncology.

Detection of circulating cancer cells by nested reverse transcription-polymerase chain reaction of cytokeratin-19 (K19)--possible clinical significance in advanced gastric cancer

Intermediate filament cytokeratin-19 (K19) protein is expressed in normal and malignant gastrointestinal epithelial cells, but not in peripheral blood (PB). Small amount of circulating gastric cancer cells can be detected by a sensitive nested reverse transcription-polymerase chain reaction (RTPCR) with primers specific for K19 mRNA. Thirty-four PB samples obtained from patients with inoperable/metastatic gastric cancer were examined. The mononuclear cell (MNC) fraction was collected by Ficoll centrifugation, and followed by total RNA extraction by acid guanidinium thiocyanate-phenol-chloroform method. RNA from 8 gastric cancer cell lines and the mononuclear cells of 33 healthy adults were used as positive and negative controls, respectively. DNA fragment of 774 bp amplified by the internal primers was found to be a highly reliable marker for K19 mRNA expression. The sensitivity of detection was between 1 and 10 cells/10(6) normal MNCs. The K19 transcripts were detected in 20.6% (7/34; 8-37%, 95% C.I.) of PB samples. None of the other pertinent clinicopathological features, including the disease extent and the histopathologic types of the tumors, were related to the expression of K19 in PB. All 34 patients had been treated by systemic chemotherapy. Among the 17 non-responders to chemotherapy, the survival of the 4 patients with detectable K19 was significantly shorter than that of 13 patients without detectable K19 in their circulating blood (p = 0.014). However, the survival impact of K19 was less significant in the other 17 patients whose tumors had responded to systemic chemotherapy. Of the whole group of patients, the median survival of the 7 and 27 patients with and without detectable K19 in their circulating blood was 1 and 3.5 months, respectively (p = 0.368). We concluded that detecting circulating cancer cells by K19 nested RT-PCR is associated with poor prognosis of gastric cancer, particularly in those patients who are not responsive to systemic chemotherapy.

Fluorine-18 fluoromisonidazole tumour to muscle retention ratio for the detection of hypoxia in nasopharyngeal carcinoma

In vivo demonstration of hypoxia is of significance for tumour patient management. Fluorine-18 fluoromisonidazole ([18F]FMISO) is a proven hypoxic imaging agent. We developed an [18F]FMISO tumour to muscle retention ratio (TMRR) for the detection of tumour hypoxia in nasopharyngeal carcinoma (NPC). Data were acquired by positron emission tomography (PET) of the nasopharynx and neck after intravenous injection of 370 MBq of [18F]FMISO. Two imaging protocols were adopted: a long protocol for comprehensive dynamic information and a short protocol for a simple, clinically convenient imaging procedure. Tomograms were reconstructed and evaluated visually. ROI analysis on the basis of time-activity curve evaluation was performed to calculate the TMRR of NPC or cervical nodal metastases (CNMs) in relation to the suboccipital muscles at 2 h. The calculation of the TMRR was exactly the same for both the long and the short protocol as two 30-min composite frames had been created immediately after intravenous injection and 2 h after injection of [18F]FMISO in the long protocol. The normal tissue to muscle retention ratio (NTMRR) was derived similarly from the normal nasopharynx. The data of 12 controls and 24 patients with NPC were analysed. The long protocol was used in 15 patients, and the short protocol in nine. In controls, the mean NTMRR+/-1 SD was 0.96+/-0.14. The mean TMRRs for NPC and CNMs were 2.56+/-1.50 and 1.35+/-0.51, respectively; these values were significantly higher than the mean NTMRR for normal controls (P<0.005 in each case). At the retention threshold value of 1.24, tumour hypoxia occurred in 100% of the primary lesions of NPC and 58% of CNMs. The TMRR for undifferentiated carcinoma was significantly lower than that for non-keratinized carcinoma (P<0.05). The [18F]FMISO TMRR is a simple and clinically useful index for detecting tumour hypoxia in NPC.

Detection of anaerobic odontogenic infections by fluorine-18 fluoromisonidazole

Odontogenic infections are a potential risk for patients who receive cervicofacial radiotherapy and should be treated before irradiation. Anaerobic microbial infections are the most common causes. This study assessed the value of the hypoxic imaging agent fluorine-18 fluoromisonidazole (FMISO) in detecting anaerobic odontogenic infections. Positron emission tomography (PET) imaging was performed at 2 h after injection of 370 MBq (10 mCi) of FMISO in 26 nasopharyngeal carcinoma patients and six controls with healthy teeth. Tomograms were interpreted visually to identify hypoxic foci in the jaw. All patients received thorough dental examinations as a pre-radiotherapy work-up. Fifty-one sites of periodontitis, 15 periodontal abscesses, 14 sites of dental caries with root canal infection, 23 sites of dental caries without root canal infection, and seven necrotic pulps were found by dental examination. Anaerobic pathogens were isolated from 12 patients. Increased uptake of FMISO was found at 45 out of 51 sites of periodontitis, all 15 sites of periodontal abscess, all 14 sites of dental caries with root canal infection, all seven sites of necrotic pulp and 15 sites of dental caries without obvious evidence of active root canal infection. No abnormal uptake was seen in the healthy teeth of patients or in the six controls. The diagnostic sensitivity, specificity, positive and negative predictive values, and accuracy of FMISO PET scan in detecting odontogenic infections were 93%, 97%, 84%, 99% and 96%, respectively. 18F-fluoride ion bone scan done in three patients showed that 18F-fluoride ion plays no role in the demonstration of anaerobic odontogenic infection. FMISO PET scan is a sensitive method for the detection of anaerobic odontogenic infections, and may play a complementary role in the evaluation of the dental condition of patients with head and neck tumours prior to radiation therapy.

Technetium-99m-DMSA renal SPECT in diagnosing and monitoring pediatric acute pyelonephritis

This study compares the sensitivity of 99mTc-dimercaptosuccinic acid (DMSA) renal SPECT with planar scintigraphy, concluding the importance of 99mTc-DMSA renal SPECT for the early diagnosis of acute pyelonephritis (APN) in patients under 3 yr of age.

METHODS

Twenty-seven children under 3 yr of age, with clinical and/or laboratory suspicion of APN, were investigated. All 99mTc-DMSA renal SPECT and planar images and voiding cystoureterogram (VCUG) were obtained within 3 days of hospitalization.

RESULTS

In the first examination, renal cortical defects were detected in 23 patients (42 kidneys) with SPECT and in 9 patients (11 kidneys) with planar scintigraphy. One year after treatment, constant renal cortical lesions were observed in 11 patients (14 kidneys) with SPECT and 4 patients (4 kidneys) with planar scintigraphy. The high grades of vesicoureteral reflux (VUR) (grade >or= 3) correlate better with APN diagnosed by SPECT (34 kidneys) than by planar scintigraphy (8 kidneys). Multiple renal cortical defects (number of lesions >or= 4) were only seen in patients under 1.5 yr old and none of those with a negative 99mTc-DMSA renal SPECT had a positive 99mTc-DMSA renal planar scintigraphy at any time. There is a significant difference (p < 0.05) between the diagnostic ability of these two methods of examination.

CONCLUSION

Our results suggest that 99mTc-DMSA renal SPECT should be used, where possible, instead of planar DMSA in routine examination of children with clinical suspicion of APN, especially for those under 3 yr of age.

Superscan in patients with nasopharyngeal carcinoma

Bone scintigraphy plays an important role in the early detection of bone metastases in patients with nasopharyngeal carcinoma and serial scans may aid the clinician to assess the therapeutic response. A superscan is a pattern described as abnormal bone scan, indicating extensive bony metastases associated with various neoplastic diseases. Bone scans from 407 patients with nasopharyngeal carcinoma were reviewed retrospectively. Only six superscans (1.5%) were found. The appearance of a superscan is frequently accompanied by an abnormal titer of serological markers IgG-VCA and IgA-VCA, liver metastases, and poor survival. Although a superscan rarely occurs in nasopharyngeal carcinoma, its appearance may represent a poor prognosis in these patients.

Effect of egg white on serum cholesterol concentration in young women

In a previous study we observed favorable effects of egg white on serum lipids in rats and mice. The present study was designed to elucidate these effects in 24 female university students with moderate hypercholesterolemia. About 30% of total protein was supplied with egg white, tofu or cheese. The experiment was conducted for a complete menstruation cycle of each subject. Lipid intake was about 30% of total energy intake. The energy intake of each subject was constant throughout the experiment. Body weight was measured every morning. Daily activity was measured by a pedometer. Blood was withdrawn after an overnight fast on the first, 15th and last days and serum lipids were measured. Body weight was measured every morning. Daily activity was measured by a pedometer. Blood was withdrawn after an overnight fast on the first, 15th and last days and serum lipids were measured. Body weight and daily activity were maintained in all the groups throughout the experiment. The egg white group showed a similar decrease in the total cholesterol (Total-C) concentration but a greater increase of high-density lipoprotein cholesterol (HDL-C) concentration as compared to the tofu group and a greater decrease in Total-C and low-density lipoprotein cholesterol (LDL-C) concentrations and a greater increase in the HDL-C concentration as compared to the cheese group (p < 0.05). The results indicate the favorable effects of egg white in the control of hypercholesterolemia.