High-resolution color doppler ultrasound examination and related risk factor analysis of lower extremity vasculopathy in type 2 diabetes patients

This study aims to investigate the value of high-resolution color Doppler ultrasonography (HR-CDU) in the evaluation of lower-extremity vasculopathy (LEV) and its related risk factors in type 2 diabetes mellitus (T2DM) patients. Two hundred forty T2DM patients were selected, who underwent lower-extremity arterial HR-CDU. The patients were divided into the LEV group (V group) and the nonvasculopathy group (A group). The V group was then divided into the mild (B group), moderate (C group), and severe (D group) subgroups. The relevant clinical parameters were simultaneously recorded. The results showed that the lesion-positive detection rate of HR-CDU was significantly higher than that of clinical examination. The age, disease duration, smoking history, blood pressure, blood sugar, fibrinogen (FIB), C-reactive protein (CRP), uric acid (UA), and urinary albumin excretion (UAE) in the V group were higher than in the N group. In the logistic regression analysis, smoking history, age, disease duration, FIB, UA, and fasting blood glucose were independent risk factors of T2DM LEV. The incidence of LEV in T2DM patients increased significantly with increasing age, UA, FIB, CRP, UAE, disease duration, and smoking history, and the vasculopathy level became more severe. In conclusion, age, disease duration, smoking history, blood pressure, blood sugar, FIB, CRP, UA, and UAE are the related risk factors of LEV in T2DM patients.

Transposon variation by order during allopolyploidisation between Brassica oleracea and Brassica rapa

Although many studies have shown that transposable element (TE) activation is induced by hybridisation and polyploidisation in plants, much less is known on how different types of TE respond to hybridisation, and the impact of TE-associated sequences on gene function. We investigated the frequency and regularity of putative transposon activation for different types of TE, and determined the impact of TE-associated sequence variation on the genome during allopolyploidisation. We designed different types of TE primers and adopted the Inter-Retrotransposon Amplified Polymorphism (IRAP) method to detect variation in TE-associated sequences during the process of allopolyploidisation between Brassica rapa (AA) and Brassica oleracea (CC), and in successive generations of self-pollinated progeny. In addition, fragments with TE insertions were used to perform Blast2GO analysis to characterise the putative functions of the fragments with TE insertions. Ninety-two primers amplifying 548 loci were used to detect variation in sequences associated with four different orders of TE sequences. TEs could be classed in ascending frequency into LTR-REs, TIRs, LINEs, SINEs and unknown TEs. The frequency of novel variation (putative activation) detected for the four orders of TEs was highest from the F1 to F2 generations, and lowest from the F2 to F3 generations. Functional annotation of sequences with TE insertions showed that genes with TE insertions were mainly involved in metabolic processes and binding, and preferentially functioned in organelles. TE variation in our study severely disturbed the genetic compositions of the different generations, resulting in inconsistencies in genetic clustering. Different types of TE showed different patterns of variation during the process of allopolyploidisation.

DDIT3 overexpression increases odontoblastic potential of human dental pulp cells

OBJECTIVES

Human dental pulp cells (HDPCs) with multi-potential differentiational capacity can undergo odontoblastic differentiation when stimulated with proinflammatory cytokines. However, factors linking proinflammatory stimuli and their odontoblastic differentiation have, as yet, not been completely understood. As an apoptotic transcription factor, DDIT3 plays a crucial role in the inflammatory reaction and in osteogenic differentiation. Thus, we hypothesized that DDIT3 may participate in odontoblastic differentiation of HDPCs.

MATERIALS AND METHODS

Immunofluorescent staining was used to detect expression of DDIT3 in HDPCs and effects of TNFα, on its nuclear accumulation. HDPCs that overexpressed DDIT3 were developed and their proliferation and odontoblastic differentiation abilities were examined. qRT-PCR was employed to detect mineralization-related genes, including ALP, runt-related transcription factor-2 (Runx2), osterix (OSX), dentin sialophosphoprotein (DSPP), dentin matrix acidic phosphoprotein 1 (DMP1) and osteocalcin (OCN). Western blot analysis was performed to detect expression of DSPP protein.

RESULTS

DDIT3 was expressed in HDPCs. TNFα treatment enhanced mRNA expression as well as nuclear accumulation of DDIT3 (slightly). DDIT3 overexpression reduced HDPC proliferation, however, it increased their calcium nodule formation and expression of OSX, DSPP, DMP1 and OCN.

CONCLUSIONS

DDIT3 may be a factor that links proinflammatory stimuli and differentiation of HDPCs.

Trap healing and ultralow-noise Hall effect at the surface of organic semiconductors

Fundamental studies of intrinsic charge transport properties of organic semiconductors are often hindered by charge traps associated with static disorder present even in optimized single-crystal devices. Here, we report a method of surface functionalization using an inert non-conjugated polymer, perfluoropolyether (PFPE), deposited at the surface of organic molecular crystals, which results in accumulation of mobile holes and a 'trap healing' effect at the crystal/PFPE interface. As a consequence, a remarkable ultralow-noise, trp-free conduction regime characterized by intrinsic mobility and transport anisotropy emerges in organic single crystals, and Hall effect measurements with an unprecedented signal-to-noise ratio are demonstrated. This general method to convert trap-dominated organic semiconductors to intrinsic systems may enable the determination of intrinsic transport parameters with high accuracy and make Hall effect measurements in molecular crystals ubiquitous.

Effects of modified LDL and HDL on retinal pigment epithelial cells: a role in diabetic retinopathy?

AIMS/HYPOTHESIS

Blood-retina barrier leakage in diabetes results in extravasation of plasma lipoproteins. Intra-retinal modified LDLs have been implicated in diabetic retinopathy (DR), but their effects on retinal pigment epithelial (RPE) cells and the added effects of extravasated modified HDLs are unknown.

METHODS

In human retinas from individuals with and without diabetes and DR, immunohistochemistry was used to detect ApoB, ApoA1 and endoplasmic reticulum (ER) stress markers. In cell culture, human RPE cells were treated with native LDL (N-LDL) or heavily-oxidised glycated LDL (HOG-LDL) with or without pretreatment with native HDL (N-HDL) or heavily-oxidised glycated HDL (HOG-HDL). Cell viability, oxidative stress, ER stress, apoptosis and autophagy were assessed by Cell Counting Kit-8 assay, dichlorofluorescein assay, western blotting, immunofluorescence and TUNEL assay. In separate experiments, RPE cells were treated with lipid oxidation products, 7-ketocholesterol (7-KC, 5-40 μmol/l) or 4-hydroxynonenal (4-HNE, 5-80 μmol/l), with or without pretreatment with N-HDL or HOG-HDL.

RESULTS

ApoB, ApoA1 staining and RPE ER stress were increased in the presence of DR. HOG-LDL but not N-LDL significantly decreased RPE cell viability and increased reactive oxygen species generation, ER stress, apoptosis and autophagy. Similarly, 4-HNE and 7-KC decreased viability and induced ER stress. Pretreatment with N-HDL mitigated these effects, whereas HOG-HDL was less effective by most, but not all, measures.

CONCLUSIONS/INTERPRETATION

In DR, extravascular modified LDL may promote RPE injury through oxidative stress, ER stress, autophagy and apoptosis. N-HDL has protective effects, but HOG-HDL is less effective. Extravasation and modification of HDL may modulate the injurious effects of extravasated modified LDL on the retinal pigment epithelium.

Mechanisms of modified LDL-induced pericyte loss and retinal injury in diabetic retinopathy

AIMS/HYPOTHESIS

In previous studies we have shown that extravasated, modified LDL is associated with pericyte loss, an early feature of diabetic retinopathy (DR). Here we sought to determine detailed mechanisms of this LDL-induced pericyte loss.

METHODS

Human retinal capillary pericytes (HRCP) were exposed to 'highly-oxidised glycated' LDL (HOG-LDL) (a model of extravasated and modified LDL) and to 4-hydroxynonenal or 7-ketocholesterol (components of oxidised LDL), or to native LDL for 1 to 24 h with or without 1 h of pretreatment with inhibitors of the following: (1) the scavenger receptor (polyinosinic acid); (2) oxidative stress (N-acetyl cysteine); (3) endoplasmic reticulum (ER) stress (4-phenyl butyric acid); and (4) mitochondrial dysfunction (cyclosporin A). Oxidative stress, ER stress, mitochondrial dysfunction, apoptosis and autophagy were assessed using techniques including western blotting, immunofluorescence, RT-PCR, flow cytometry and TUNEL assay. To assess the relevance of the results in vivo, immunohistochemistry was used to detect the ER stress chaperon, 78 kDa glucose-regulated protein, and the ER sensor, activating transcription factor 6, in retinas from a mouse model of DR that mimics exposure of the retina to elevated glucose and elevated LDL levels, and in retinas from human participants with and without diabetes and DR.

RESULTS

Compared with native LDL, HOG-LDL activated oxidative and ER stress in HRCP, resulting in mitochondrial dysfunction, apoptosis and autophagy. In a mouse model of diabetes and hyperlipidaemia (vs mouse models of either condition alone), retinal ER stress was enhanced. ER stress was also enhanced in diabetic human retina and correlated with the severity of DR.

CONCLUSIONS/INTERPRETATION

Cell culture, animal, and human data suggest that oxidative stress and ER stress are induced by modified LDL, and are implicated in pericyte loss in DR.

Registration of wheat lines carrying the partial stripe rust resistance gene Yr36 without the Gpc-B1 high grain protein content allele

While the high-temperature adult plant resistance gene Yr36 represents a promising source of quantitative and potentially race non-specific resistance to wheat stripe rust (causal organism Puccinia striiformis Westend. f. sp. tritici), its tight linkage (0.3 cM) with the high-grain protein content gene Gpc-B1 may hinder its introgression in certain cases, such as in soft wheat varieties requiring low grain protein content or in lines where the Gpc-B1 allele may be associated with a yield penalty. The development and registration of two donor lines, one tetraploid (Triticum turgidum L. ssp. durum; PI 656793) and one hexaploid (T. aestivum L. ssp. aestivum; PI 664549), each carrying the resistant wild emmer (T. turgidum ssp. dicoccoides) allele for Yr36 linked with the non-functional Gpc-B1 allele, are intended to overcome this potential limitation. Meiotic recombination events breaking the linkage between these two genes were discovered during the systematic screening of a population of 4,500 F₂ durum plants (cv. Langdon background) used to fine map Yr36. One of the critical recombination events was selected for fixation by self-pollination and transferred to a California adapted spring hexaploid background (breeding line UC1110₅₊₁₀) through five generations of backcrossing. Genotypic and phenotypic data confirm the presence of Yr36 and the non-functional Gpc-B1 allele in both registered lines.

Negative words on surgical wards result in therapeutic failure of patient-controlled analgesia and further release of cortisol after abdominal surgeries

BACKGROUND

The perception of pain is germane to the environmental stimuli. Nurses on surgical wards are the main contributor in influencing patients' psychophysiological fettle. The aim of the study was to investigate the effect of different words, negative or positive, from nurses on postoperative pain therapy with patient-controlled analgesia (PCA).

METHODS

1500 ASA I-II patients, who underwent abdominal hysterectomy, were screened and 771 were randomized into one of four groups. In the no words group (NW, N.=35), no words was delivered. The positive (PW, N.=248), partially negative (NW1, N.=241) and totally negative (NW2, N.=247) groups received corresponding words when treating with morphine PCA, the words were given singly at the 3(rd), 6(th), 12(th), 18(th) h and repeatedly at the 3(rd) and 6(th) h, and each group was redivided into six subgroups according to varying time points. Pain intensity, morphine consumption, side effects, overall sedation and satisfaction scores were recorded and plasma cortisol was tested.

RESULTS

A total of 614 patients completed the study. Negative words expressed significant influence on pain therapy at the 3(rd) and 6(th) h after surgeries (P<0.01), and this effect was more convenient in repeatedly treated patients (P<0.001). Positive and the 12(th) and 18(th) h negative words displayed little role in pain management. Morphine consumption, side effects, satisfaction and cortisol level converted with the change of the pain intensity. No intergroup differences were observed in patients' overall conditions.

CONCLUSION

Negative words on surgical wards influenced postoperative pain management at the earlier period of time after abdominal surgeries associated with the HPA axis activation.

Prevalence of insomnia and associated symptoms in patients with cancer

9098

Background: High rates of insomnia have been reported in patients undergoing treatment for cancer. The etiology of insomnia in these patients is unknown, but may be related to psychological factors (anxiety or depression), pain, treatment-related toxicity, or other co-morbid medical conditions. Insomnia has been linked with increased rates of depression, decreased quality of life, and increased fatigue in other patient populations, and is therefore important to understand in the context of cancer. Methods: The Patient Care Monitor (PCM; Supportive Oncology Services, Memphis, TN) is a validated software package assessing oncology-related patient symptoms using a 11- point Likert scale. This instrument is administered routinely to patients at each office visit at most community oncology clinics within the Accelerated Community Oncology Research Network (ACORN). Cross-sectional patient-reported data from 11,445 consecutive patients evaluated at ACORN sites are presented here. Results: The mean age of the sample was 61.5 (±14.2; range 18–95), and 74.3% was female. 25% had received chemotherapy within the prior month. The sample size by tumor site was as follows: breast- 3,316; GU- 2,966; GI- 1,634; hematologic- 1,373; lung- 1,224; head and neck- 501; skin- 321. 55% of the pts reported trouble sleeping, with 26% describing this trouble as moderate or severe. Mean values from patient reported symptoms on the PCM are reported below. 21.9% of patients without insomnia had recent chemotherapy, compared with 27.5% of patients with insomnia who had recent therapy (p<.001). Conclusions: Insomnia occurs commonly in patients with cancer, and is associated with significantly increased fatigue, pain, and depressed mood. Additional research will explore changes in insomnia over the course of treatment, and relate these to possible etiological factors.

[Table: see text]

No significant financial relationships to disclose.

Imaging and therapy for Epstein-Barr virus-associated gastric cancer

4644

Background: Epstein-Barr virus (EBV) has been identified in a wide variety of malignancies, including gastric carcinomas. The virus encodes kinases that phosphorylate nucleoside analogs such as 2’-deoxy-2’-fluoro-5-iodo-1-beta-D- arabinofuranosyluracil (FIAU). We hypothesized that it might be possible to use the viral enzyme to specifically concentrate [125I]FIAU or [131I] FIAU in tumor cells harboring virus and thus deliver imaging and therapeutic radiation. Bortezomib is a potent stimulator of viral kinase expression in EBV tumor cell lines. Methods: We imaged lytic induction in vivo and evaluated the effect of [131I] FIAU on human cancer xenografts in SCID mice. These include a tumor line engineered to constitutively express the EBV thymide kinase (EBVTK), and a control engineered with a sham vector (SHAM), as well one EBV-associated human gastric tumor (KT tumor). Mice were treated with buffer, bortezomib (2μg/g), or radiolabeled FIAU or radiolabeled FIAU and bortezomib in combination. For imaging, mice, [125I]-FIAU and SPECT/CT were used. For therapy, 131I-FIAU was used and tumor dimensions were monitored with calipers. Results: SPECT/CT imaging with [125I]-FIAU of tumor-bearing SCID mice showed selective concentration of radiotracer in tumor tissue in EBVTK (3/3) and in EBV-associated KT tumors (3/3) when animals were pretreated with bortezomib. Treatment with buffer had no effect on 3 EBVTK tumors and 3 SHAM tumors all of which increased in volume. Treatment with 1.6 mCi of [131I]-FIAU alone led to tumor response in 3/3 mice with EBVTK tumors and 0/3 mice with SHAM tumors. Treatment with [131I]-FIAU alone had no effect on EBV KT tumor xenografts (0/3) and all tumors increased in volume. Treatment with bortezomib induced modest responses in all KT tumors. However, treatment with bortezomib and [131I]-FIAU led to marked tumor regression (>80%) in EBV-associated KT tumors (3/3). Conclusions: Treatment with bortezomib leads to selective concentration of radiolabeled FIAU in the EBV-associated tumor xenografts. In combination with [131I]-FIAU it leads to tumor regression.

No significant financial relationships to disclose.

Randomized study of early intervention compared to standard intervention with darbepoetin-alpha (DA) for chemotherapy-induced anemia (CIA) in early stage breast cancer (ESBC)

19538

Background: Dose dense chemotherapy (DDC) with sequential doxorubicin/ cyclophosphamide followed by paclitaxel Q 14 days has an established place in the treatment of ESBC. However, moderate/severe CIA is a common consequence and therapeutic intervention is frequent. We sought to determine if early intervention at the onset of anemia with DA could reduce the emergence of more severe anemia during therapy and maintain quality of life compared to later intervention. Material and Methods: Non-iron deficient (ferritin > 50) patients (pts) with hemoglobin (Hb) levels >11.0 g/dl scheduled to receive adjuvant or neoadjuvant DDC for ESBC were recruited. Pts were randomly assigned prior to chemotherapy to initiate treatment with DA 200 μg q2w SQ when Hb < 11.5 g/dl (early intervention, EARLY), or DA 200 μg q2w SQ when Hb < 10.0 g/dl (standard intervention, STD) with end of treatment defined as 14 days after the last cycle of chemotherapy. Dose escalation for inadequate response of < 1 g/dl after 6 weeks of DA and dose withholding/reduction for Hb >13 g/dl were pre-specified. Results: The complete sample of 149 pts have been accrued (median age of 53.1, range 28.7 - 74.5). Analysis of fatigue ratings show a trend towards lower fatigue scores in EARLY at Hb nadir, and at end of study,(ANOVA, Group x Time interaction, p=.07). Discussion: Early intervention with DA significantly reduces the risk of developing moderate/severe CIA and increases time spent in the target range during DDC for ESBC.

[Table: see text]

No significant financial relationships to disclose.

Phase II trial of nab-paclitaxel (nanoparticle albumin-bound paclitaxel (ABX)) + capecitabine (XEL) in first-line treatment of metastatic breast cancer (MBC)

1053

Background: ABX and XEL both have substantial single agent activity in MBC. Taxane and anti-metabolite doublets improve response rate and TTP and longer survival. ABX administered weekly has an excellent safety and efficacy profile with maintenance of dose intensity. This study was designed to test the safety and efficacy of ABX + XEL given in a novel combination schedule. Methods: This phase II, multicenter open label study utilized ABX 125 mg/m2 IV on day 1, 8 and with no premeds and capecitabine 825 mg/m2 PO BID days 1–14 on a Q 3 week cycle. The primary endpoint is objective response rate, with evaluation performed after every 2 cycles. Entry criteria include measurable MBC by RECIST criteria, age >18, PS 0–2, no prior chemo for metastatic disease, > 6 months since adjuvant fluoropyrimidine and/or paclitaxel. Results: The full sample of 50 patients (pts) have been enrolled; data from 43 pts are available for analysis. Median age is 58 (range 23.7–90.6). 37% received prior adjuvant anthracycline and 33% prior adjuvant taxane. Median number of metastatic sites is 2 (range 1–7), with most common sites of disease liver, 53.5%; bone, 51.2%; and lung, 14%. 226 cycles of therapy have been delivered. 5 pts required a dose reduction in XEL (3 pts to 650 mg/m2; 2 to 550 mg/m2) and 4 pts had dose reduction in ABX to 100 mg/m2. XEL dose reductions occurred due to hand-foot syndrome (3), neutropenia (1), and fatigue (1). ABX dose reductions occurred due to mucositis, diarrhea, fatigue, and neuropathy (1 pt each). 10 pts had grade 3–4 non-hematologic AEs: 3 hand-foot syndrome, 4 fatigue, and 3 GI. Hematologic AEs included 4 with grade 3 and 1 with grade 4 neutropenia, and 2 with grade 4 febrile neutropenia. The most common AEs of any grade were GI (30), dermatological (23), fatigue (15), neuropathy (12), and hand-foot syndrome (11). The incidence of Grade 1–2 neuropathy was 25% (no grade 3–4). Of 38 pts available for analysis of response, the overall response rate is 47.5%: PR 39.5%, CR 8%. Total of 15 pts have stable disease, 20 pts have completed 6+ cycles.

No significant financial relationships to disclose.

The wheat and barley vernalization gene VRN3 is an orthologue of FT

Winter wheat and barley varieties require an extended exposure to low temperatures to accelerate flowering (vernalization), whereas spring varieties do not have this requirement. In this study, we show that in these species, the vernalization gene VRN3 is linked completely to a gene similar to Arabidopsis FLOWERING LOCUS T (FT). FT induction in the leaves results in a transmissible signal that promotes flowering. Transcript levels of the barley and wheat orthologues, designated as HvFT and TaFT, respectively, are significantly higher in plants homozygous for the dominant Vrn3 alleles (early flowering) than in plants homozygous for the recessive vrn3 alleles (late flowering). In wheat, the dominant Vrn3 allele is associated with the insertion of a retroelement in the TaFT promoter, whereas in barley, mutations in the HvFT first intron differentiate plants with dominant and recessive VRN3 alleles. Winter wheat plants transformed with the TaFT allele carrying the promoter retroelement insertion flowered significantly earlier than nontransgenic plants, supporting the identity between TaFT and VRN-B3. Statistical analyses of flowering times confirmed the presence of significant interactions between vernalization and FT allelic classes in both wheat and barley (P < 0.0001). These interactions were supported further by the observed up-regulation of HvFT transcript levels by vernalization in barley winter plants (P = 0.002). These results confirmed that the wheat and barley FT genes are responsible for natural allelic variation in vernalization requirement, providing additional sources of adaptive diversity to these economically important crops.

Enzymatically-targeted 131I therapy for herpesvirus-associated malignancies

3010

Background: Epstein-Barr virus (EBV) and Kaposi’s sarcoma herpesvirus (KSHV) are associated with tumors including AIDS-related lymphoma, Burkitt’s lymphoma, Hodgkin’s lymphoma, nasopharyngeal carcinoma and Kaposi’s sarcoma. Both viruses encode kinases that selectively phosphorylate nucleoside analogs such as ganciclovir and FIAU. We hypothesized that it might be possible to use the viral enzymes to specifically concentrate 131I-FIAU in tumor cells harboring virus and thus deliver therapeutic radiation. Bortezomib is a potent stimulator of viral kinase expression in gammaherpesvirus tumor cell lines. Methods: We evaluated the effect of 131I-FIAU on human cancer xenografts in SCID mice. These included a tumor line engineered to constitutively express the EBV thymidine kinase (EBVTK), and a control engineered with a sham vector (SHAM), as well 2 EBV(+) Burkitt’s lymphoma (BL) lines, and 1 KSHV(+) primary effusion lymphoma (PEL) cell line. Mice were treated with buffer, bortezomib 2 ug/gm, or I-FIAU, or I-FIAU and bortezomib in combination. For imaging, mice, 125I -FIAU and SPECT were used. For therapy, 131I-FIAU was used and tumor dimensions were monitored with calipers. Results: Treatment with buffer had no effect on on 3 EBVTK tumors and 3 SHAM tumors all of which increased in volume. Treatment with 1.4 mCi 131I-FIAU alone led to tumor responses (>90% volume reduction at 10 days) in 3/3 mice with EBVTK tumors and 0/3 mice with SHAM tumors. Treatment with 131I-FIAU alone had no effect on BL (0/3) or PEL (0/9) xenografts and all tumors increased in volume. Treatment with bortezomib induced modest responses in all tumors but had no greater effect on EBVTK tumors than SHAM tumors. However, treatment with bortezomib and 131I-FIAU led to marked tumor regression (>95%) in each of the virus-associated tumors (3/3 BL, 9/9 PEL). SPECT imaging with 125I-FIAU showed selective concentration of radiolabel in tumor tissue in the EBVTK tumor (2/2) and in viral tumors (6/6) when bortezomib was administered. There was no selective concentration in the absence of bortezomib treatment in the viral tumors (0/8). Conclusions: Treatment with bortezomib leads to selective concentration of labeled FIAU in the herpesvirus-associated tumor xenografts evaluated and to regression of tumor when the isotope is 131I.

No significant financial relationships to disclose.

Screening a library of FDA-approved drugs identifies agents that induce lytic viral infection in EBV-associated tumors

2002

Background: Epstein-Barr virus (EBV) is associated with a variety of tumors including AIDS lymphoma, Burkitt’s lymphoma, nasopharyngeal carcinoma and Hodgkin’s lymphoma. We hypothesized that drugs used in practice might alter viral gene expression in tumor cells in ways that might be important to understand. For example induction of lytic viral gene expression leads to expression of immunodominant CD8 T cell antigens and expression of the viral thymidine kinase (which phosphorylates ganciclovir and other nucleotide analogues). Methods: A library of FDA-approved drugs that includes 2720 agents was screened to identify those that upregulated EBV lytic gene expression. The screen involved a Burkitt’s cell line with a recombinant GFP-EBV that assayed the impact of agents on replication of the complete viral genome, and assay of a lytic promoter reporter construct. Results: The assay identified 146 agents in the whole virus replication assay, 195 agents in the promoter assay, and 54 agents that were active in both assays. Agents with activity could be grouped into 4 families: anti-tubulin drugs, glucocorticoid and other steroid hormones, DNA damaging agents and nucleotide analogues (including cytarabine and gemcitabine), and the proteasome inhibitor bortezomib. Anti-tubulin drugs and nucleotide analogues were less active in thes whole virus assay than the promoter assay whereas bortezomib showed similar activity in both assays. Followup studies confirmed that bortezomib is a potent viral lytic activator that increases expression of the viral thymidine kinase and virion production in several different Burkitt’s lymphoma and primary effusion lymphoma cell lines. Although bortezomib decreases NFKB levels, in vitro investigations with an IKB repressor suggests that inhibition of NFKB alone does not account for lytic activation. Conclusions: Many cancer chemotherapeutic agents are upregulators of EBV lytic expression. Bortezomib is among the most potent. As strategies for using lytic induction therapeutically evolve, these agents may have an important role to play.

No significant financial relationships to disclose.

Volatile anaesthetic effects on phospholipid binding to synaptotagmin 1, a presynaptic Ca2+ sensor

BACKGROUND

Volatile anaesthetics have important effects on synaptic transmission in the CNS. Depression of excitatory transmission involves reduced transmitter release via unidentified presynaptic mechanisms. Synaptotagmin 1 is a synaptic vesicle-associated protein that regulates Ca(2+)-evoked transmitter release involving critical Ca(2+)/phospholipid interactions within its C2 domains.

METHODS

We analysed the effects of halothane and isoflurane on the binding of purified recombinant rat synaptotagmin 1 C2A, C2B and C2AB domains to radiolabelled phospholipid liposomes.

RESULTS

Halothane and isoflurane had no significant effects on the maximal binding or Ca(2+) dependence of binding of synaptotagmin 1 C2 domains to mixed phospholipid vesicles composed of either phosphatidylserine/phosphatidylcholine or phosphatidylinositol/phosphatidylcholine.

CONCLUSIONS

Inhibition of synaptic vesicle exocytosis by volatile anaesthetics does not appear to involve an effect on the critical Ca(2+)/phospholipid binding properties of synaptotagmin 1, a Ca(2+) sensor involved in regulating evoked Ca(2+)-dependent neurotransmitter release.