Adaptive Relation-Aware Network for zero-shot classification

Supervised learning-based image classification in computer vision relies on visual samples containing a large amount of labeled information. Considering that it is labor-intensive to collect and label images and construct datasets manually, Zero-Shot Learning (ZSL) achieves knowledge transfer from seen categories to unseen categories by mining auxiliary information, which reduces the dependence on labeled image samples and is one of the current research hotspots in computer vision. However, most ZSL methods fail to properly measure the relationships between classes, or do not consider the differences and similarities between classes at all. In this paper, we propose Adaptive Relation-Aware Network (ARAN), a novel ZSL approach that incorporates the improved triplet loss from deep metric learning into a VAE-based generative model, which helps to model inter-class and intra-class relationships for different classes in ZSL datasets and generate an arbitrary amount of high-quality visual features containing more discriminative information. Moreover, we validate the effectiveness and superior performance of our ARAN through experimental evaluations under ZSL and more practical GZSL settings on three popular datasets AWA2, CUB, and SUN.

Zero-Shot Learning With Attentive Region Embedding and Enhanced Semantics

The performance of zero-shot learning (ZSL) can be improved progressively by learning better features and generating pseudosamples for unseen classes. Existing ZSL works typically learn feature extractors and generators independently, which may shift the unseen samples away from their real distribution and suffers from the domain bias problem. In this article, to tackle this challenge, we propose a variational autoencoder (VAE)-based framework, that is, joint Attentive Region Embedding with Enhanced Semantics (AREES), which is tailored to advance the zero-shot recognition. Specifically, AREES is end-to-end trainable and consists of three network branches: 1) attentive region embedding is used to learn the semantic-guided visual features by the attention mechanism (AM); 2) a decomposition structure and a semantic pivot regularization are used to extract enhanced semantics; and 3) a multimodal VAE (mVAE) with the cross-reconstruction loss and the distribution alignment loss is used to obtain a shared latent embedding space of visual features and semantics. Finally, features' extraction and features' generation are optimized together in AREES to address the domain shift problem to a large extent. The comprehensive evaluations on six benchmarks, including the ImageNet, demonstrate the superiority of the proposed model over its state-of-the-art counterparts.

Radical Hydrocarboxylation of Unactivated Alkenes via Photocatalytic Formate Activation

Herein we disclose a strategy to promote the hydrocarboxylation of unactivated alkenes using photochemical activation of formate salts. We illustrate that an alternative initiation mechanism circumvents the limitations of prior approaches and enables hydrocarboxylation of this challenging substrate class. Specifically, we found that accessing the requisite thiyl radical initiator without an exogenous chromophore eliminates major byproducts that have plagued attempts to exploit similar reactivity for unactivated alkene substrates. This redox-neutral method is technically simple to execute and effective across a broad range of alkene substrates. Feedstock alkenes, such as ethylene, are hydrocarboxylated at ambient temperature and pressure. A series of radical cyclization experiments indicate how the reactivity described in this report can be diverted by more complex radical processes.

High Electron Mobility Hot-Exciton Induced Delayed Fluorescent Organic Semiconductors

The development of high mobility emissive organic semiconductors is of great significance for the fabrication of miniaturized optoelectronic devices, such as organic light emitting transistors. However, great challenge exists in designing key materials, especially those who integrates triplet exciton utilization ability. Herein, dinaphthylanthracene diimides (DNADIs), with 2,6-extended anthracene donor, and 3'- or 4'-substituted naphthalene monoimide acceptors were designed and synthesized. By introducing acceptor-donor-acceptor structure, both materials show high electron mobility. Moreover, by fine-tuning of substitution sites, good integration with high solid state photoluminescence quantum yield of 26 %, high electron mobility of 0.02 cm²  V^-1  s^-1 , and the feature of hot-exciton induced delayed fluorescence were obtained in 4'-DNADI. This work opens a new avenue for developing high electron mobility emissive organic semiconductors with efficient utilization of triplet excitons.

The state of the art in beyond 5G distributed massive multiple-input multiple-output communication system solutions

Beyond fifth generation (5G) communication systems aim towards data rates in the tera bits per second range, with improved and flexible coverage options, introducing many new technological challenges in the fields of network architecture, signal pro- cessing, and radio frequency front-ends. One option is to move towards cell-free, or distributed massive Multiple-Input Multiple-Output (MIMO) network architectures and highly integrated front-end solutions. This paper presents an outlook on be- yond 5G distributed massive MIMO communication systems, the signal processing, characterisation and simulation challenges, and an overview of the state of the art in millimetre wave antennas and electronics.

QSPR modelling for intrinsic viscosity in polymer-solvent combinations based on density functional theory

Linear and nonlinear quantitative structure-property relationship (QSPR) models were developed based on a dataset with 65 polymer-solvent combinations. Seven quantum chemical descriptors, dipole moment, hardness, chemical potential, electrophilicity index, total energy, HOMO and LUMO orbital energies, were calculated with density functional theory at the B3LYP/6-31 G(d) level for polymers and solvents. Considering the strong correlation between intrinsic viscosity and weight, size, shape as well as topological structure of polymers and solvents, topological descriptors were also applied in this work. Meanwhile, the most appropriate polymer structure representation was investigated by considering 1-5 monomeric repeating units. The molecular descriptors were first screened by using the genetic algorithms-multiple linear regression (GA-MLR), with coefficient of determinations (r2) of 0.78 and 0.83 for the training set and the prediction set, respectively. The support vector machine model (SVM) model based on the selected descriptors subset showed a r2 value of 0.95 for the training set and 0.93 for the prediction set. All statistical results suggest that the established QSPR models have good predictability. Furthermore, a new test set obtained from the literature was used for further validation. The r2 values were 0.81 for the MLR model and 0.90 for the SVM model.

CFD simulation of subcooled boiling flow in PWR 5 ⨯ 5 rod bundle

This paper describes the computational fluid dynamics (CFD) methodology to simulate the boiling flow in a typical Pressurized Water Reactor (PWR) 5 ⨯ 5 rod bundle. The method includes the Eulerian-Eulerian two-fluid model coupled with the improved wall heat partitioning model. The NUPEC PWR Subchannel and Bundle Test (PSBT) International Benchmark are used for validation. The simulated surface averaged void fraction agree well with the experimental data, which indicate the promising application of the present method for modeling the boiling flow in the fuel rod bundle. The main emphasis of current research has been given to the analysis of the phase distribution around and downstream the spacer grid, the effect of the spacer grid structure, including the mixing vanes, the springs and the dimples on the void fraction distribution is investigated. The findings can contribute to a better understanding of three dimensional flow boiling characteristics and can be used to assist in optimizing the spacer grid.

Long non-coding RNA UCA1 promotes the progression of paclitaxel resistance in ovarian cancer by regulating the miR-654-5p/SIK2 axis

OBJECTIVE

Ovarian cancer (OC) is a common tumor in women, and the development of chemoresistance is the major obstacle to its treatment. Long non-coding RNAs (LncRNAs) have been linked to chemoresistance in many cancers. However, the function of lncRNA urothelial carcinoma associated1 (UCA1) in paclitaxel (PTX) resistance of OC is not well elucidated.

PATIENTS AND METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of UCA1, microRNA-654-5p (miR-654-5p) and salt inducible kinase 2 (SIK2). Cell PTX resistance and proliferation were evaluated by 3-(4, 5-dimethyl-2 thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The abilities of apoptosis, migration and invasion were measured by Flow cytometry and Transwell assays, respectively. Dual-luciferase reporter assay was used to verify the interaction among UCA1, miR-654-5p and SIK2. Besides, Western blot analysis was performed to assess the protein level of SIK2.

RESULTS

UCA1 was markedly upregulated in OC tissues and PTX-resistant OC cells. Silencing of UCA1 restrained the PTX resistance, reduced the proliferation, migration, invasion and enhanced the apoptosis of PTX-resistant OC cells. MiR-654-5p could be sponged by UCA1, and the inhibitory effect of its overexpression on the progression of PTX-resistant OC cells could be reversed by overexpressed-UCA1. Moreover, SIK2 was a target of miR-654-5p. Silencing of SIK2 could hinder the PTX resistance and suppress the progression of PTX-resistant OC cells, while miR-654-5p inhibitor could invert this inhibitory effect. Also, the expression of SIK2 was regulated by miR-654-5p and UCA1 expression.

CONCLUSIONS

LncRNA UCA1 plays an active role in PTX resistance of OC and is crucial to maintain the development of PTX resistance in OC, which provides a new therapeutic target for the study of OC chemoresistance.

64 SIN3 transcription regulator family member A regulates porcine early embryonic development by modulating CCNB1 expression

SIN3 transcription regulator family member A (SIN3A) is the central scaffold protein of the SIN3/HDAC (histone deacetylase) transcriptional repressor complex. We previously found that SIN3A participates in the mouse pre-implantation development by finetuning HDAC1 expression. However, it remains unresolved whether this functional significance of SIN3A is conserved in other mammals. The objective of this work was thus to characterise the expression profiles and the functional role of SIN3A in pre-implantation development using non-rodent animal models. RNA sequencing results show that a large amount of SIN3A mRNA is present in oocytes and early embryos before embryonic genome activation and a low amount thereafter, suggesting a maternal origin of SIN3A in all species examined. Interestingly, immunofluorescence data show that SIN3A protein level peaks at the 4-cell stage in pigs compared with the morula stage in cattle, suggesting a differential role of SIN3A among species. To explore the function of SIN3A in early embryonic development, we used a short interfering (si)RNA-mediated knockdown approach in porcine parthenogenetic activated (PA) embryos. Immunocytochemical analysis showed that SIN3A levels were diminished ∼80% compared with nonspecific siRNA (NC) injected control (n=3). To monitor the developmental potential of embryo depleted of SIN3A, we injected SIN3A-siRNA into MII stage oocytes, followed by parthenogenetic activation, and percent cleavage and blastocyst formation were recorded. We found that SIN3A knockdown (KD) did not affect the cleavage rate (NC vs. KD, 83.63±3.63% vs. 80.08±4.66%, n=5), but significantly reduced blastocyst rate compared with the NC group (NC vs. KD, 36.64±4.28% vs. 6.33±3.12%, n=5). Specifically, SIN3A depletion in early embryos causes developmental arrest at 2-cell stage in pigs but does not affect early embryonic development in bovines. In contrast with mouse data, SIN3A depletion results in only a slight decrease and even no difference in HDAC1 expression in porcine and bovine early embryos, respectively. In addition, HDAC1 knockdown does not cause 2-cell block but leads to a reduced blastocyst rate, suggesting that the effect of SIN3A depletion on porcine early embryos is independent of HDAC1. RNA-Seq analysis was used to compare the global transcript content between NC and KD 2-cell embryos. A total of 23 genes (14 upregulated and 9 downregulated) had undergone significant changes. Interestingly, cyclin B1 (CCNB1) ranked second among downregulated genes. To test whether knockdown of CCNB1 would display a similar phenotype in porcine early embryos, we injected CCNB1-siRNA into pronuclear stage. CCNB1 KD resulted in a similar phenotype as SIN3A depletion. Injection of exogenous CCNB1 mRNA into SIN3A-depleted embryos could partly rescue embryonic development. In conclusion, our results indicate SIN3A plays an essential role in porcine early embryonic development, probably involving the regulation of CCNB1 expression. This work was funded by National Natural Science Foundation of China, the Anhui Provincial Natural Science Foundation and China Postdoctoral Science Foundation.

JNK activation and translocation to mitochondria mediates mitochondrial dysfunction and cell death induced by VDAC opening and sorafenib in hepatocarcinoma cells

The multikinase inhibitor sorafenib, and opening of voltage dependent anion channels (VDAC) by the erastin-like compound X1 promotes oxidative stress and mitochondrial dysfunction in hepatocarcinoma cells. Here, we hypothesized that X1 and sorafenib induce mitochondrial dysfunction by increasing reactive oxygen species (ROS) formation and activating c-Jun N-terminal kinases (JNKs), leading to translocation of activated JNK to mitochondria. Both X1 and sorafenib increased production of ROS and activated JNK. X1 and sorafenib caused a drop in mitochondrial membrane potential (ΔΨ), a readout of mitochondrial metabolism, after 60 min. Mitochondrial depolarization after X1 and sorafenib occurred in parallel with JNK activation, increased superoxide (O2•-) production, decreased basal and oligomycin sensitive respiration, and decreased maximal respiratory capacity. Increased production of O2•- after X1 or sorafenib was abrogated by JNK inhibition and antioxidants. S3QEL 2, a specific inhibitor of site IIIQo, at Complex III, prevented depolarization induced by X1. JNK inhibition by JNK inhibitors VIII and SP600125 also prevented mitochondrial depolarization. After X1, activated JNK translocated to mitochondria as assessed by proximity ligation assays. Tat-Sab KIM1, a peptide selectively preventing the binding of JNK to the outer mitochondrial membrane protein Sab, blocked the depolarization induced by X1 and sorafenib. X1 promoted cell death mostly by necroptosis that was partially prevented by JNK inhibition. These results indicate that JNK activation and translocation to mitochondria is a common mechanism of mitochondrial dysfunction induced by both VDAC opening and sorafenib.

Association between intraplaque neovascularization assessed by contrast-enhanced ultrasound and the risk of stroke

AIM

To determine the cut-off value of the area ratio under the curve (ARUC) for predicting symptoms of stroke.

MATERIALS AND METHODS

Contrast-enhanced ultrasound was used to analyse intraplaque neovascularization (IPN). The correlations between the ARUC and risk factors of stroke were examined. A receiver operating characteristic curve was used to determine the cut-off value of the ARUC.

RESULTS

Using a quantitative analysis method for IPN, the ARUC was significantly higher in the symptomatic group than in the asymptomatic group (p=0.017). The ARUC was positively associated with the homocysteine level (r=0.429, p=0.002) and high-sensitivity C-reactive protein level (r=0.424, p=0.003). Regression analysis showed that the ARUC was a risk factor for symptoms of stroke. The receiver operating characteristic curve showed that the cut-off value for symptoms was 0.24; the sensitivity was 77%, and the specificity was 70%; the positive predictive value was 68%, and the negative predictive value was 78%.

CONCLUSION

IPN was a risk factor for the occurrence of the clinical symptoms of stroke. Patients with an ARUC of >0.24 had a higher risk of stroke.

Utilizing size-based thresholds of stiffness gradient to reclassify BI-RADS category 3-4b lesions increases diagnostic performance

AIM

To investigate the role of utilizing size-based thresholds of stiffness gradient in diagnosing solid breast lesions and optimizing original Breast Imaging-Reporting And Data System (BI-RADS) classifications.

MATERIALS AND METHODS

Two-hundred and twenty-seven consecutive women underwent shear-wave elastography (SWE) before ultrasound-guided biopsy, and 234 solid breast lesions categorized as BI-RADS 3-5 were analysed. Receiver operating characteristic curve analysis was performed based on histopathology. Diagnostic performance among SWE, BI-RADS, and their combination were compared.

RESULTS

The stiffness gradient correlated with the standard deviation of elasticity (SD, r=0.90), and with Tozaki's pattern classification (r=0.64). The area under the receiver operating characteristic curves (AUC) for stiffness gradient (0.939) outperformed SD (0.897) or colour pattern (0.852). Due to significant association with lesion size (r=0.394, p<0.001), stiffness gradient's size-based thresholds (lesions >15 mm: 82.5 kPa; lesions ≤15 mm: 51.1 kPa) were established to reclassify BI-RADS 3-4b lesions. Upgrading category 3 lesions (over the corresponding cut-off value, 3 to 4a) and downgrading categories 4a-4b lesions (less than or equal to the corresponding cut-off value, 4b to 4a, 4a to 3), yielded significant improvement in specificity (90.28% versus 77.78%, p<0.001) and AUC (0.948 versus 0.926, p=0.035) than BI-RADS alone. No significant loss emerged in the sensitivity (88.89% versus 91.11%, p=0.500).

CONCLUSION

Stiffness gradient exhibited better discriminatory ability than SD or four-colour pattern classification in determining solid breast lesions and applying its size-specific thresholds to categorize BI-RADS 3-4b lesions could improve diagnostic performance.

The role of 18F-FDG PET/CT in the management of patients with secondary haemophagocytic lymphohistiocytosis

AIM

To investigate the ability of combined 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography (PET)/computed tomography (CT) to determine potential causes of secondary haemophagocytic lymphohistiocytosis (sHLH) and to predict prognosis.

MATERIAL AND METHODS

Forty-three patients (male/female 20/23, median age 48.5 years), who were diagnosed with sHLH and underwent FDG-PET/CT before treatment, were retrospectively reviewed. The clinical characteristics were compared to identify the predictors of high-yield FDG-PET/CT. Univariate and multivariate analyses were conducted to identify factors associated with survival. Statistical analysis was performed using SPSS version 19.0.

RESULTS

PET results were helpful in 65.1% (28/43), whilst non-contributory in 34.9% (15/43) of patients with regard to the final diagnosis. Lymphoma was the most common (25/43) reason for sHLH, and patients with focal FDG uptake were more likely to be diagnosed with underlying diseases. C-reactive protein (CRP) was found to be a good indicator for the usefulness of PET/CT in HLH patients. Multivariate analysis showed that therapy regimen (hazard ratio [HR]=4.99, p=0.026), fibrinogen (FBG) <1.5 g/l (HR=3.87, p=0.049) and spleen:mediastinum ratio (SP/M) (HR=7.44, p=0.006) were independent prognostic factors for survival.

CONCLUSION

FDG-PET/CT could be a useful technique for detecting underlying diseases causing sHLH. CRP was a useful predictor of FDG-PET/CT effectiveness. Therapy regimen, FBG level, and SP/M were independent prognostic factors for HLH survival.

Lentivirus pre-packed with Cas9 protein for safer gene editing

The CRISPR/Cas9 system provides an easy way to edit specific site/s in the genome and thus offers tremendous opportunity for human gene therapy for a wide range of diseases. However, one major concern is off-target effects, particularly with long-term expression of Cas9 nuclease when traditional expression methods such as via plasmid/viral vectors are used. To overcome this limitation, we pre-packaged Cas9 protein (Cas9P LV) in lentiviral particles for transient exposure and showed its effectiveness for gene disruption in cells, including primary T cells expressing specific single guide RNAs (sgRNAs). We then constructed an 'all in one virus' to express sgRNAs in association with pre-packaged Cas9 protein (sgRNA/Cas9P LV). We successfully edited CCR5 in TZM-bl cells by this approach. Using an sgRNA-targeting HIV long terminal repeat, we also were able to disrupt HIV provirus in the J-LAT model of viral latency. Moreover, we also found that pre-packaging Cas9 protein in LV particle reduced off-target editing of chromosome 4:-29134166 locus by CCR5 sgRNA, compared with continued expression from the vector. These results show that sgRNA/Cas9P LV can be used as a safer approach for human gene therapy applications.

[Characteristics and perioperative management of hemophilia patients with fractures]

OBJECTIVE

To investigate the characteristics and perioperative management of hemophilia patients with fracture.

METHODS

Retrospectively, we analyzed 8 patients with hemophilia combined with fracture, who were admittted to our department from 2005 to 2013. Six patients were with hemophilia A and two with hemophilia B; Based on the severity of hemophilia, 2 cases were light, 3 moderate and 3 severe; Based on the location of fracture, 4 cases were femoral neck fractures, 1 femoral intertrochanteric fracture, 1 bilateral distal femur fractures, 1 tibiofibula fracture, and 1 humerus intercondylar fracture. Blood coagulation factor replacement therapy was conducted preoperatively, intraoperatively and postoperatively, All the patients underwent closed or open reduction and internal fixation or joint replacement. Also, we analyzed the perioperative complications and observed whether the fracture healed.

RESULTS

The average age was 33.5 years (14 to 47 years); In 6 cases, fractures occurred at femur, accounting for 75% of all the fractures; Femoral neck fracture was treated by closed reduction and hollow screws fixation; Femoral intertrochanteric fracture, distal femur fracture, and tibiofibula fracture were treated by open reduction and internal fixation with plate; Humerus intercondylar fracture was treated by elbow joint replacement. Intraoperative bleeding was from 50 to 600 mL, an average of 262 mL; Perioperatively, the average use of FVIII/activated prothrombin complex concentrates (APCC) was 358 U/kg (125 to 554 U/kg). Postoperatively, poor wound healing was observed in 2 patients, and the condition improved after symptomatic treatment; In patients with internal fixation, all the fractures united, and the average healing time was 14 weeks. No complications such as fixation loosening or rupture occurred after internal fixation.

CONCLUSION

Hemophilia combined with fracture mainly occurred in the young, and the site of fracture was given priority to femur. With perfect preoperative preparation, on the basis of the replacement therapy, hemophilia combined with fractures was safe for surgical treatment, and postoperative fractures healing wasgood. But the risk of poor wound healing was high.

Correlation between down-expression of miR-431 and clinicopathological significance in HCC tissues

BACKGROUND AND AIMS

Researches have shown that miRNAs have been proposed as novel diagnostic biomarkers for classification and prognostic stratification of HCC. However, whether or not miR-431 contributes to the progression of HCC remains unknown. Therefore, we aimed to investigate the clinicopathological significance of miR-431 in HCC.

METHODS

MiR-431 expression in 95 HCC cases and corresponding adjacent non-cancerous tissues was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, statistical analysis was performed to identify the correlations between expression of miR-431 and a variety of clinicopathological parameters and patient recurrence. The area under the receiver operating characteristic curve (AUC) was used to evaluate the accuracy of miR-431 as a biomarker for HCC diagnosis and prediction of disease deterioration.

RESULTS

MiR-431 was markedly down-regulated in the HCC samples (1.1885 ± 0.75867) compared with corresponding adjacent tumor tissues (1.7957 ± 0.89333, P < 0.001). The AUC of low miR-431 expression to diagnose HCC was 0.668 (95 % CI 0.592-0.744, P < 0.001). MiR-431 down-expression was correlated with multiple malignant characteristics, including lymph node metastasis (r = -0.455, P < 0.001), clinical TNM stage (r = -0.223, P = 0.030), MTDH (r = -0.292, P = 0.006), vaso-invasion (r = -0.204, P = 0.047), MVD (r = -0.281, P = 0.006) and HCV (r = 0.215, P = 0.037). Additionally, the recurrent time of lower miR-431 expression group was 56.602 ± 3.914 months, much longer than that in the high expression group (50.009 ± 2.731 months), however, no significant difference was noted (χ (2) = 0.005, P = 0.943).

CONCLUSIONS

The down-expression of miR-431 is partially responsible for a series of clinicopathological features which may be tightly correlated with the progression of HCC. Thus, expression of miR-431 may be proposed as a new factor in association with the progression of HCC.

Folic acid supplementation and dietary folate intake, and risk of preeclampsia

BACKGROUND/OBJECTIVES

Folic acid supplementation has been suggested to reduce the risk of preeclampsia. However, results from few epidemiologic studies have been inconclusive. We investigated the hypothesis that folic acid supplementation and dietary folate intake before conception and during pregnancy reduce the risk of preeclampsia.

SUBJECTS/METHODS

A birth cohort study was conducted in 2010-2012 at the Gansu Provincial Maternity & Child Care Hospital in Lanzhou, China. A total of 10,041 pregnant women without chronic hypertension or gestational hypertension were enrolled.

RESULTS

Compared with nonusers, folic acid supplement users had a reduced risk of preeclampsia (OR=0.61, 95% CI: 0.43-0.87). A significant dose-response of duration of use was observed among women who used folic acid supplemention during pregnancy only (P-trend=0.007). The reduced risk associated with folic acid supplement was similar for mild or severe preeclampsia and for early- or late-onset preeclampsia, although the statistical significant associations were only observed for mild (OR=0.50, 95% CI: 0.30-0.81) and late-onset (OR=0.60, 95% CI: 0.42-0.86) preeclampsia. The reduced risk associated with dietary folate intake during pregnancy was only seen for severe preeclampsia (OR=0.52, 95% CI: 0.31-0.87, for the highest quartile of dietary folate intake compared with the lowest).

CONCLUSIONS

Our study results suggest that folic acid supplementation and higher dietary folate intake during pregnancy reduce the risk of preeclampsia. Future studies are needed to confirm the associations.

Blood glucose fluctuation affects skin collagen metabolism in the diabetic mouse by inhibiting the mitogen-activated protein kinase and Smad pathways

BACKGROUND

We recently reported that in mice, blood glucose fluctuations (BGF) produced more detrimental effects on skin structure and function than did diabetes alone.

AIM

To determine whether treatment of BGF changes the collagen metabolism in the skin of diabetic mice, and to explore its possible molecular mechanism further.

METHODS

The study used diabetic and BGF animal models. Immunohistochemistry, western blotting and real-time PCR analysis were used to detect the expression of type I collagen, matrix metalloproteinase (MMP)-1, MMP-2 and MMP-13, tissue inhibitor of metalloproteinase (TIMP)-1, extracellular signal-regulated kinase, p38, and Smad2/3. The activities of mitogen-activated protein kinase (MAPK) and Smad signal molecules were also detected by western blotting, and the skin fibroblast ultrastructure was examined using an electron microscope.

RESULTS

BGF treatment produced a twofold reduction in type I collagen synthesis compared with diabetes-only mice. Expression of MMP-1, MMP-2 and MMP-13 increased markedly in the BGF-treated mice, but TIMP-1 expression was strongly downregulated by the BGF treatment. There was also evidence of higher levels of apoptosis of skin fibroblasts after BGF treatment.

CONCLUSIONS

BGF treatment can affect collagen production in the skin of diabetic BGF mice by inhibiting collagen synthesis and increasing collagen degradation. Furthermore, both MAPK and Smad signalling pathways seem to play a role in the inhibition of collagen production in diabetic mice treated with BGF.

Abstract P5-16-04: A phase I study of a DNA plasmid based vaccine encoding the HER-2/neu intracellular domain in subjects with HER2+ breast cancer

HER2+ breast cancer (BC) is associated with early disease relapse, usually to distant sites. This would suggest relapse is due to residual microscopic disease. Generation of vaccine-induced HER2-specific CD4+ T helper immunity (Th1) may result in immunologic eradication of residual HER2+ tumor cells and subsequent development of immunologic memory and epitope spreading (ES), which has been associated with a survival benefit in vaccinated BC patients. We have shown HER2 peptide-based vaccines can generate immunity in BC however, more recently we developed a plasmid DNA based vaccine (pNGVL3-hICD) which may have additional advantages over synthetic peptides. DNA vaccines offer a strategy to immunize against multiple tumor antigens and are able to elicit both CTL and Th1 immunity. Plasmid DNA can also remain at the vaccine site, providing a constant source of antigen. Intradermal (i.d.) delivery of DNA vaccines with GM-CSF as adjuvant may enhance immunogenicity due to local influx of dermal Langerhans cells. We have recently completed a phase I trial utilizing pNGVL3-hICD in optimally treated stage III and IV HER2+ BC patients and have defined vaccine safety profile, optimal dose and schedule; and demonstrated vaccine biologic activity.

Methods: A total of 66 subjects with stage III and IV HER2+ BC in complete remission were enrolled sequentially into 1 of 3 pNGVL3-hICD dose arms (22 subjects/arm): Arm 1=10µg, Arm 2=100 µg, and Arm 3 = 500µg. All vaccines were admixed with 100µg GM-CSF and given i.d. monthly for a total of 3 vaccines. Toxicity was assessed at baseline, during vaccination and at follow-up. Immune responses to HER ICD and ECD were assessed with IFN-γ ELISPOT at baseline and serially through week 60 post-vaccination. Linear regression analysis was used to compare differences in immune responses from baseline over the whole study period between dose arms. Vaccine site skin biopsies and peripheral lymphocytes were serially analyzed for plasmid persistence via RT-PCR.

Results: 64 subjects (20 in Arm 1; 22 in Arm 2; 22 in Arm 3) completed 3 vaccines. Age, stage/status, number of previous chemotherapy regimens, and use of bisphosphonate and trastuzumab therapies was similar across dose arms. Vaccine-related toxicity was primarily Grade 1/2 injection site reactions, myalgias, arthralgias and not significantly different between arms; no cardiac or grade IV toxicity was observed. Immune responses to HER2 ICD were significantly better in Arms 2 and 3 vs Arm 1 (p = 0.001 and 0.002, respectively) but not statistically different between Arms 2 and 3. 38 patients had DNA plasmid persistence at the vaccination site with no difference between arms. There has been no detection of DNA plasmid in lymphocytes from patients in all arms. Analyses of survival and ES (HER ECD immune responses) are on-going and will be presented.

Conclusions: pNGVL3-hICD was safe and effectively induced persistent HER2 ICD specific Th1 immunity without increased cardiac toxicity. Moreover, immunity was present more than 1 year after end of vaccination, indicative of vaccine-induced immunologic memory.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-16-04.

Quantitative assessment of external carotid artery territory supply with modified vessel-encoded arterial spin-labeling

BACKGROUND AND PURPOSE

In patients with carotid stenosis or occlusion, cerebral blood could be supplied through collateral pathways to improve regional blood flow and protect against ischemic events. The contribution of collaterals from the ICA can be assessed by depiction of vascular perfusion territories with ASL. However, so far there is no method available to evaluate the collateral perfusion territory from the ECA in MR imaging. In this study, we present a new labeling scheme based on VE-ASL to quantitatively assess the perfusion territory of the ECA.

MATERIALS AND METHODS

A new labeling approach with a Hadamard encoding scheme was developed to label major arteries, especially the ECA. Twelve healthy subjects with normal cerebrovascular anatomy were examined to demonstrate their perfusion territories. Eight patients with carotid artery stenosis or occlusion were assessed before and after surgery to show changes of their collateral blood supply.

RESULTS

The proposed method enables assessment of the perfusion territories of the ECA. Good agreement was found between the vascular territories and normal cerebrovascular anatomy in healthy subjects. For the patients with carotid stenosis or occlusion, our noninvasive results provided information on collateral flow comparable with that from DSA. Their collateral flows from the ECA, moreover, could be quantitatively estimated pre- and postoperatively.

CONCLUSIONS

The modified approach has been validated by the consistency of collateral perfusion territories with cerebrovascular anatomy, and quantitative assessment of collaterals proved useful for assisting in evaluating therapeutic interventions.

OT2-05-05: Phase I/II Study of Adoptive T Cell Therapy Following In Vivo Priming with a HER2 Peptide-Based Vaccine in Patients with Stage IV Breast Cancer

Background

Adoptive T cell therapy has evolved from preclinical setting to a potentially feasible treatment strategy for advanced breast cancer (BC). However, the ability to expand tumor antigen specific T cells ex vivo has been one of the major hurdles that has limited clinical translation of adoptive T cell therapy. Tumor specific T cells are rare in unprimed patients and generating large bulk cultures from rare precursor frequencies is difficult. We have found immunizing HER2+ patients to increase tumor specific T cell precursor frequencies to the levels of a vaccinated foreign antigen markedly improves the ability to generate large numbers of tumor specific T cells in vitro. We hypothesize that T cell expansion strategies that are facilitated by prior immunization will be clinically useful in the treatment of advanced BC.

Design: A Phase I/II non-randomized, single arm study. Priming with a HER2 ICD vaccine will be performed at 1 week intervals for a total of 3 vaccines. Patients will undergo leukapheresis 2 weeks after the 3rd vaccine to collect PBMC for T cell expansion. Patients will be pre-treated with cyclophosphamide 24 hours prior to 1st T cell infusion and then receive up to 3 dose-escalating infusions of T cells given 7–10 days apart. Three HER2 vaccine booster immunizations will then be administered at 1, 2, and 4 months after the final T cell infusion. Follow-up for persistent and continued immunity will then ensue.

Aims: To evaluate the safety of infusing escalating doses of HER2 specific T cells into patients with advanced HER2+ BC using ex vivo expanded autologous T cells, to investigate to what extent HER2 specific T cell immunity can be boosted or generated in individuals after infusion of HER2 specific T cells, to evaluate how long T cell immune augmentation persists in vivo after adoptive transfer of HER2 specific T cells and subsequent booster immunizations.

Criteria: Patients with HER2+ Stage IV BC who: have been maximally treated and not achieved a complete remission, have stable or slowly progressive disease, HER2+, and have adequate LVEF.

Statistical Methods: Toxicity will be determined by chemical and clinical parameters evaluated at various time points. If the true probability of a DLT is 0.11, then the probability of observing 0 DLT's in 20 patients is 0.097. If the true probability of a DLT is 0.18, then the probability of observing ≤1 DLT's in 20 patients is 0.102, and if the true probability of a DLT is 0.27, then the probability of observing ≤2 DLT's in 20 patients is 0.064. Therefore, with low observed rates of DLT (≤10%), we can be reasonably confident (∼90%) with 20 patients that the true DLT rate is &lt; 0.27. Immunologic response, defined as the successful boosting of precursor frequency with infusion of HER2−specific T cells, will be evaluated by assessing the change in T cell level from baseline. To assess the durability of the T cell response, we are primarily interested in estimating the proportion of patients whose T cells persist at a level the same or greater as the level after the final T cell infusion as long as 6 months following the final booster vaccine.

Accrual: Target=20/Actual=14

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT2-05-05.

Investigation of irradiation by different nonablative lasers on primary cultured skin fibroblasts

BACKGROUND

A variety of lasers with different wavelengths and biological effects are widely used for nonablative skin rejuvenation, but the underlying mechanisms have not been fully investigated.

AIM

To investigate the effects of irradiation by different nonablative lasers on collagen synthesis and the antioxidant status of cultured fibroblasts to identify a possible mechanism for laser photorejuvenation.

METHODS

Cultured skin fibroblasts were irradiated with three different lasers: 532 nm potassium-titanyl phosphate (KTP), 1064 nm Q-switched neodymium:yttrium-aluminium-garnet (Nd:Yag) and 1064 nm long-pulse Nd:YAG, and production of collagen and changes in lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were assayed.

RESULTS

Irradiation by all three lasers led to a marked increase in collagen production. Two major antioxidant enzymes, SOD and GSH, were significantly increased, whereas MDA was markedly reduced after laser irradiation. No change in LDH activity was found between nonirradiated and irradiated fibroblasts.

CONCLUSION

This study indicates that the increased collagen synthesis by fibroblasts after laser treatment may be partly due to improved antioxidant capacity, which reduces oxidative stress and thus stimulates new collagen production.

Phase I-II Study of Denileukin Diftitox (ONTAK®) in Patients with Advanced Refractory Breast Cancer

Background: CD4+CD25+Foxp3+ regulatory T cells (Tregs) are potent suppressors of CD4+ and CD8+ T cells, produce the immunosuppressive cytokine TGF-β; and as such, may down-regulate immune responses to tumor antigens. Additionally, Tregs are increased in the peripheral blood (PB) and tumors of breast cancer patients; and are associated with poor prognosis. Depletion of PB and tumor-associated Tregs may induce anti-tumor immunity by augmenting anti-tumor effector T cells and enhancing endogenous tumor specific immunity. ONTAK®, a diphtheria/IL-2R fusion protein depletes PB Tregs when given intravenously (IV) and selectively targets tumor cells that overexpress IL-2R. Breast tumors have been shown to overexpress IL-2R which is associated with their malignant potential. We hypothesized that ONTAK® could (1) have direct anti-tumor activity in breast cancers that overexpress IL-2R, and (2) deplete Tregs resulting in generation of functional immune effector cells and enhanced anti-tumor immunity. A phase I-II study was conducted to evaluate the safety of IV ONTAK® and assess its effect on Tregs and endogenous immunity in patients with advanced refractory breast cancer.Materials and Methods: 15 patients with progressive stage IV breast cancer following standard therapy were sequentially enrolled and received IV ONTAK® 18 mcg/kg/day on Days1-5 every 21 days for a total of 6 cycles and/or maximal tumor response. Toxicity was evaluated on Days 1 8, and 14 of each cycle per CTEP CTCAE v3.0. Tumor response was evaluated per RECIST at baseline, and after cycles 3 and 6. PB was collected at baseline and after cycles 2, 4, and 6 for evaluation of Tregs, sIL-2R, and endogenous tumor-antigen specific T cell immunity to HER-2/neu (HER2), CEA, and MAGE-3 via RT-PCR, LUMINEX and IFN-γ ELISPOT assay, respectively. Expression of IL-2R in patient paraffin embedded tumor samples was analyzed by IHC analysis.Results: 15 subjects have been enrolled and 14/15 have completed treatment; median age is 58 years (range, 32-69) and median salvage regimens is 3 (range, 2-8). 7/14 subjects had triple negative tumors. 7 subjects completed 1-2 and 7 completed 3-6 ONTAK® cycles, respectively. 4 subjects who completed 6 cycles of ONTAK® had SD or PR per RECIST. ONTAK®-related toxicities have been primarily grade I and II fatigue, nausea, and headache; and transient grade 3 hypoalbuminemia and lymphopenia. Preliminary data in 2 subjects shows enhanced tumor-antigen specific T cell immunity defined as mean tumor antigen-specific T cell precursors:PBMC to CEA (pre- ONTAK® 1:250,000; post- ONTAK® 1:15,000) and HER2 (pre- ONTAK® 1:63,000; post- ONTAK® 1:6,312). Immunologic analyses are ongoing and will be presented along with clinical data on all patients.Conclusions: ONTAK® is well-tolerated when used as a salvage regimen in heavily pretreated breast cancer patients. Additionally, ONTAK® treatment can enhance endogenous immunity to known breast cancer antigens and potentially lead to more effective eradication of tumor.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4130.

Phase II Study of a HER-2/Neu (HER2) Intracellular Domain (ICD) Vaccine Given Concurrently with Trastuzumab in Patients with Newly Diagnosed Advanced Stage Breast Cancer

HER2 is a tumor antigen in breast cancer and several trials have demonstrated that breast cancer patients can be immunized against this protein. We have developed HER2 peptide based vaccines that are aimed at eliciting CD4+ Th1 tumor antigen specific T cell responses. Th1 effectors provide immunologic memory, enhance cross priming which will allow the elaboration of tumor specific CD8+ T cells, and stimulate epitope spreading which we have shown to be a potential biomarker of clinical response. 52 patients will be enrolled with the primary objective to determine relapse free survival after active immunization. Eligible patients are newly diagnosed with Stage III (B or C) or Stage IV breast cancer and begin vaccination within 6 months of starting maintenance trastuzumab. This interim report will present data on the first 25 patients enrolled; 21 stage IV and 4 locally advanced patients. The vaccine is well tolerated with all adverse events (AE) being Grade I or 2. The most common AE is injection site reaction. Moreover, the combination of HER2 vaccination with trastuzumab did not result in additive cardiac toxicity in these patients. Immune responses were evaluated by IFN-gamma ELISPOT. To date, 88% of patients immunized developed significant immunity to the components of the ICD vaccine. The majority, 75%, developed robust immunity to the HER2 protein. Our group has recently demonstrated that a broadening of immunity throughout the HER2 protein, to components of the protein that weren't in the vaccine, i.e. epitope spreading, may be associated with improved survival in vaccinated patients. 63% of immunized patients demonstrated evidence of intramolecular epitope spreading. We questioned whether such high frequencies of homing Type 1 T cells might modulate the immunosuppressive tumor microenvironment, so we evaluated whether circulating serum immunosuppressive cytokines were impacted by immunization. TGF-beta is an immunosuppressive cytokine secreted by tumor stroma and regulatory T cells. We found that the levels of serum TGF-beta decreased significantly in the majority of patients after vaccination. We further analyzed the correlation between the change of serum levels of TGF-beta post vaccination and HER2 ICD vaccine-induced T cell responses. We found that the greater the magnitude of the HER2 specific T cell response, as demonstrated by IFN-gamma secretion, the greater the decrease in serum TGF-beta (p=0.0045, r=0.742). The correlation between the increased epitope spreading T cell response and decreased levels of TGF-beta was even more significant (p=0.0003). The median overall survival has not been reached with 100% of patients alive at this time. Relapse free survival data will be presented.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5102.

A phase I study of a DNA plasmid based vaccine encoding the HER2/neu (HER2) intracellular domain (ICD) in subjects with HER2+ breast cancer

3054

Background: HER2 is overexpressed in 25% of breast cancers and plays a role in the malignant transformation of cells. Vaccine-induced immunity against the HER2 ICD correlates with antitumor responses in animal models. DNA-based vaccines offer a strategy to immunize against multiple tumor antigens and are able to elicit both CTL and T helper immune responses. Plasmid DNA can also remain at the vaccine site, providing a constant source of antigen. However, DNA vaccines have been poorly immunogenic due in part to inefficient APC transfection. Intradermal (i.d.) delivery of DNA vaccines with GM-CSF as adjuvant may enhance immunogenicity due to local influx of dermal Langerhans cells. A phase I study was conducted to evaluate the safety and immunogenicity of a DNA-based vaccine encoding the HER2 ICD. Methods: 44 subjects with stage III and IV HER2+ breast cancer in complete remission were enrolled sequentially into 2 vaccine arms (22 subjects/arm) and received 10μg pNGVL3-hICD (Arm 1) or 100μg pNGVL3-hICD (Arm 2). All vaccines were admixed with 100μg GM-CSF and given i.d. monthly for a total of 3 vaccines. Toxicity was assessed at baseline, during vaccination, and at follow-up. Immune responses were assessed with IFN-γ ELISPOT at baseline and post-vaccination. Vaccine site biopsies were analyzed for plasmid persistence via RT-PCR, 1 and 6 months after vaccination. Results: 43 subjects (21 in Arm 1; 22 in Arm 2) completed 3 vaccines. Vaccine-related toxicity in both arms was primarily grade I/II; no cardiac or grade IV toxicity was observed. 13/21 (62%) subjects in Arm 1 developed T-cell immunity, defined as HER2-specific T cell precursors:PBMC, to the HER2 protein (median 1:5,972, range 1:717–1:3,000,000) and to p776, a HER2 pan DR binding epitope (median 1:3,150, range 1:543–1:108,696). 13/19 (68%) subjects in Arm 1 had persistent plasmid DNA at the vaccine site. ELISPOT and RT-PCR analysis for Arm 2 are on-going. Conclusions: Immunization with a DNA plasmid-based HER2 vaccine is safe and immunogenic. Moreover, plasmid DNA persists at the vaccine site post-immunization and HER2+ cancer patients are able to develop immunity to the HER2 ICD.

No significant financial relationships to disclose.

Persistent immunity and survival after immunization with a HER2/neu (HER2) vaccine

3010

Background: Our initial vaccine studies showed that optimally treated breast cancer patients can be immunized against HER2 during active immunization. The majority of patients developed T-cell immunity to HER2 peptides and protein and also epitope spreading (ES). The goal of this study was to determine if patients previously immunized with a HER2 vaccine had persistent immunity years after active immunization and to assess their clinical outcome in terms of overall survival (OS). Methods: Subjects eligible for this IRB-approved long term follow-up (LTFU) study: (1) had HER2+ breast cancer and were immunized between 1996–1999 in a phase I HER2 peptide vaccine trial, (2) were at least 1 year out from their last vaccine, and (3) if donating blood samples could not be receiving chemotherapy. 52 patients (37 stage IV, 15 stage III) were identified and 21/52 patients (12 stage IV, 9 stage III) were determined to be living. All 21 subjects were contacted by letter and sent a LTFU Questionnaire. OS was defined as the time between date of vaccine study entry and death or last follow-up and was estimated using the Kaplan-Meier method. Cox proportional hazards were used to determine associations between OS and known clinical and vaccine-related immunologic factors; analyses included all 52 subjects. Long-term T-cell immunity was evaluated using IFN-γ ELISPOT assay. Results: Median follow-up time for the 21 patients still alive was 112 months (range, 104–126 months). Blood samples were collected in 10/21 subjects and 6/8 (75%) evaluble patients had persistent T-cell immunity to immunizing HER2 peptides; and 7/8 patients (88%) had T-cell immunity specific for HER2 protein and peptides not contained in their immunizing mix (defined as ES). In multivariate analysis, number of chemotherapy regimens prior to vaccination (HR=5.7 (CI 95%, 1.5–23; p=<0.001)), and development of ES after HER2 vaccination (HR=0.34 (CI 95%, 0.12–1.0; p=0.05)) were independent predictors of OS. Median OS for 33 subjects who developed ES was 84 months vs 25 months for 16 subjects who did not develop ES. Conclusions: HER2-specific T-cell immunity elicited with active immunization is durable years after vaccination has ended and the generation of ES is an independent predictor of OS.

No significant financial relationships to disclose.

Phase I study of infusion of HER2/neu (HER2) specific T cells in patients with advanced-stage HER2 overexpressing cancers who have received a HER2 vaccine

3000

Background: Adoptive T-cell therapy has shown promise in the treatment of advanced-stage melanoma. We have previously reported that expansion of HER2-specific T cells from peripheral blood mononuclear cells (PBMC) can be greatly facilitated by vaccine-priming. In this study, we evaluated the safety and clinical efficacy of infusion of HER2-specific T cells in patients with advanced HER2 overexpressing cancers. Methods: 10 patients with progressive HER2+ metastatic breast and ovarian cancer, not considered curable by conventional therapies, will be enrolled in this study. The patients must have been pre-immunized with a HER2-specific vaccine. Three escalating doses of T cells are given at 10-day intervals. Cyclophosphamide or denileukin diftitox is administrated before the first dose of T cells. Results: To date, 5 of 10 subjects have been enrolled. T cells were expanded with HER2-specific class II restricted peptides. After in vitro expansion cell products were >95% CD3+ with an average of 35% CD4+ and 60% CD8+ T cells. The maximal doses infused were 1x109-41x109 cells (median 10x109). Subjects tolerated the infusions well with the primary toxicity being related to the conditioning agent. Objective tumor regression has been observed in 2 of the 5 treated patients. One other patient has had stable disease after treatment. In patients with tumor regression, the magnitude of HER2-specific T cells in the infused product was 8-fold higher than that in patients without clinical responses. The total number of HER2-specific T cells infused was 43-fold higher in responding patients than in nonresponding patients. Moreover, HER2-specific CD4+ and CD8+ T cells persisted over a year and even augmented in magnitude post-infusion in responding patients. Conclusions: Adoptive transfer of autologous HER2 specific polyclonal T cells generated from PBMC after vaccine-priming is well tolerated and has shown evidence of some clinical efficacy in patients with advanced-stage HER2+ cancers.

No significant financial relationships to disclose.

Association of the level of HER2/neu (HER2) gene amplification in breast cancer and the magnitude of antigen specific T-cell immunity achieved after HER2 vaccination

3059

Background: Studies have demonstrated that the level of HER2 gene amplification in breast cancer, assessed by fluorescence in situ hybridization (FISH), correlates with favorable clinical response after treatment with trastuzumab. We questioned whether HER2 gene amplification impacted the development of HER2-specific T-cell immunity following immunization with a HER2 vaccine. Methods: Patients with HER2+ stage III or IV breast cancer, treated to complete remission or stable bone only disease, were enrolled in one of two concurrent clinical trials of HER2-specific vaccines. Eligibility criteria between the two studies were similar. Patients received either a plasmid DNA-based vaccine encoding the HER2 intracellular domain or a peptide-based vaccine composed of 3 HER2 class II epitopes. Peripheral blood was assessed for HER2-specific T-cell responses by interferon gamma (IFN-g) ELISPOT prior to, immediately after, and 6 months to 1 year after the end of vaccinations. Both immune response and FISH data were available on 31 patients. Results: Correlation of FISH levels to IFN-g spots/well in evaluable patients revealed the level of HER2 gene amplification was not related to the presence of pre-existent HER2-specific T-cell immunity prior to vaccination (p=0.43), the generation of a HER2-specific immune response after vaccination (p=0.35), or the persistence of the HER2-specific T-cell response (p=0.33). However, the magnitude of the T-cell response achieved was less as HER2 gene amplification increased (p=0.05). Conclusions: The level of HER2 gene amplification in the primary tumor can adversely impact the magnitude of HER2-specific T-cell immunity achieved after vaccination.

No significant financial relationships to disclose.

Combination of GM-CSF and cytosine in myelodysplasia results in improved neutrophil function

Granulocyte-macrophage colony-stimulating factor (GM-CSF) was given concurrently with low-dose cytosine arabinoside for 3 weeks to patients with myelodysplasia. Neutrophil activation as evidenced by increased chemiluminescence and reduced surface expression of CD16 was consistently seen during therapy. An attendant fall in chemotaxis was also observed. These effects occurred even when neutrophil counts did not rise significantly at lower doses of GM-CSF. Although no improvement in anaemia or thrombocytopenia was observed, the neutrophil counts became normal during therapy without significant expansion of marrow cellularity or colony-forming ability. No major toxicities were observed, even at higher dosages of GM-CSF.

Comparison of the catabolic effects of fibronectin fragments in human knee and ankle cartilages

OBJECTIVE

To compare the response of knee and ankle cartilages to fibronectin fragments (Fn-f) in terms of kinetics of matrix proteoglycan (PG) degradation and synthesis, since previous data had shown that knee was more sensitive to Fn-f in terms of steady-state PG content.

DESIGN

Human knee and ankle cartilage explants were treated with the 29kDa Fn-f, and its effects on PG-degradation kinetics, on the half-lives of 35S-sulfate-labeled PG, on PG synthesis suppression and on matrix metalloproteinase -3 (MMP-3) were compared. Cultures were also treated with the interleukin (IL) receptor antagonist protein (IRAP) in order to determine whether IL-1 is involved in the Fn-f effect.

RESULTS

The Fn-f enhanced PG-degradation rates in both human knee and ankle cartilages. Knee cartilage showed a greater effect of Fn-f on half-lives of newly synthesized 35S-labeled PG than ankle. The extent of release of MMP-3 was similar for human ankle and knee cartilages. However, PG synthesis in knee cartilage was sensitive to 10- to 100-fold lower concentrations of Fn-f than was ankle cartilage. IRAP partially reversed Fn-f activity in ankle cartilages.

CONCLUSIONS

The role of Fn-f in proteolysis leading to cartilage damage appears to be minor in human cartilages than had previously been shown for bovine. This decreased proteolysis is true for both knee and ankle. The major difference between human ankle and knee cartilage appears to be greater sensitivity to PG synthesis suppression in knee cartilage. A further indication that IL-1 is involved in the pathway was provided by the partial reversal with IRAP.

Cutting edge: regulation of uterine NKT cells by a fetal class I molecule other than CD1

The peri-implantation uterus contains an expanded population of NK1.1(+) V alpha 14(+) TCR(int) (NKT) lymphocytes. Although these cells bear the above features in common with other NKT cells populations in thymus, bone marrow, liver, and spleen, they differ from these other populations in terms of an altered V beta repertoire and absence of a CD4(+) component. In this study, we demonstrate that the uterine population also differs from other NKT cell populations because they recognize a class I/class I-like molecule other than CD1, whereas most previously described V alpha 14(+) NKT cells are CD1-restricted. Moreover, the class I/class I-like molecule leading to the uterine NKT cell expansion may be supplied by the fetus. These data demonstrate a novel mechanism whereby the fetus is capable of modulating the maternal immune system.

Effects of oxygen on kynurenine-3-monooxygenase activity

Kynurenine-3-monooxygenase (KM), the third enzyme in the kynurenine (KYN) pathway from tryptophan to quinolinic acid (QA), is a monooxygenase requiring oxygen, NADPH and FAD for the catalytic oxidation of L-kynurenine to 3-hydroxykynurenine and water. KM is innately low in the brain and similar in activity to indoleamine oxidase, the rate-limiting pathway enzyme. Accumulation in the CNS of QA, a known excitotoxin, is proposed to cause convulsions in several pathologies. Thus, we theorized that hyperbaric oxygen (HBO) induced convulsions arise from increased QA via oxygen K, effects on this pathway [Brown OR, Draczynska-Lusiak. Oxygen activation and inactivation of quinolinate-producing and iron-requiring 3-hydroxyanthranilic acid oxidase: a role in hyperbaric oxygen-induced convulsions? Redox Report 1995; 1: 383-385]. To complement prior studies on the effects of oxygen on pathway enzymes, in this paper we report the effects of oxygen on KM. Brain and liver KM enzyme are not known to be identical, and some systemically-produced KYN pathway intermediates can permeate the brain and might stimulate the brain pathway. Thus, KM from both brain and liver was assayed at various oxygen substrate concentrations to evaluate, in vitro, the potential effects of increases in oxygen, as would occur in mammals breathing therapeutic and convulsive HBO. In crude tissue extracts, KM was not activated during incubation in HBO up to 6 atm. The effects of oxygen as substrate on brain and liver KM activity was nearly identical: activity was nil at zero oxygen with an apparent oxygen Km of 20-22 microM. Maximum KM activity occurred at about 1000 microM oxygen and decreased slightly to plateau from 2000 to 8000 microM oxygen. This compares to approximately 30-40 microM oxygen typically reported for brain tissue of humans or rats breathing air, and an unknown but surely much lower value (perhaps below 1 microM) intracellularly at the site of KM. Thus HBO, as used therapeutically and at convulsive pressures, likely stimulates flux through the KM-catalyzed step of the KYN pathway in liver and in brain and could increase brain QA, by Km effects on brain KM, or via increased KM pathway intermediates produced systemically (in liver) and transported into the brain.

Natural killer 1.1(+) alpha beta T cells in the periimplantation uterus

When the developing embryo implants into the uterine wall, resident maternal immune cells may encounter antigens present on the fetal tissues. The nature and constituents of the ensuing maternal immune response, and its regulation, are of considerable interest in understanding normal and abnormal pregnancy. Here, we report the presence of natural killer (NK)1.1(+) alpha beta T cells in the murine periimplantation uterus. These cells account for a large portion of both the T-cell and natural killer cell populations in early pregnancy, while their numbers in the non-pregnant uterus and later in pregnancy are greatly reduced. Phenotypically, these NK1.1+ alpha beta T cells belong to a previously described subset of cells that bear a V alpha 14-J alpha 281-encoded T-cell receptor. Unlike other organs, where both CD4(+) and CD4(-)/CD8(-) NK1.1(+) alpha beta T cells are found, the placental/decidual population appears to be entirely CD4(-)/CD8(-). The V beta repertoire of the placental/decidual population is also altered from that of other organs, with a majority of cells expressing V beta 3. Together, these features suggest the possibility of local development. NK1.1(+) alpha beta T cells are known to recognize the class I-like CD1 molecule. Consistent with this association, we demonstrate CD1 expression by tissues within the pregnant uterus. Our findings define an additional organ-specific immune environment where NK1.1(+) alpha beta T cells may play a role, and continue to demonstrate the specialized nature of the maternal intrauterine immune system during pregnancy.

Evidence that kynurenine pathway metabolites mediate hyperbaric oxygen-induced convulsions

Metabolism of tryptophan (TRP) through the kynurenine (KYN) pathway in brain, liver, and kidney produces intermediates including the neuroactive agonist quinolinic acid (QA) and the antagonists kynurenic acid (KA) and anthranilic acid (AA) for N-methyl D-aspartate (NMDA) receptors in the central nervous system. We hypothesized that elevated concentrations of QA, KA, or AA can moderate the convulsions that are observed during exposure of rats to hyperbaric oxygen (HBO). We found that i.p. administration of TRP or KYN (both of which cross the blood-brain barrier) had no effect on HBO-induced seizures. However, AA (administered i.p.) or gavage administration of the KYN pathway blocking drug Ro 61-8048, both of which enter the brain from the circulatory system, affect the time to first convulsion and/or coma during HBO in a manner consistent with a modulatory role for seizure activity.

Cytoskeletal disruption accelerates caspase-3 activation and alters the intracellular membrane reorganization in DNA damage-induced apoptosis

In actinomycin D (AD)-induced apoptosis, caspase-3 activation and DNA cleavage in human megakaryoblastic leukemia CMK-7 cells were greatly accelerated by tubulin and actin polymerization inhibitors [e.g., colcemid (CL) and cytochalasin D (CD), respectively], but the acceleration was not found with Taxol or phalloidin. A decrease in mitochondrial transmembrane potential, release of cytochrome c into the cytosol, and cleavage of procaspase-9 to its active form preceded the activation of caspase-3 and, moreover, all of these events began earlier and/or proceeded faster in cells treated with AD plus CL or CD than in cells treated with AD only. These results suggest that cytoskeletal disruption in the apoptotic cells promotes damage of the mitochondrial membrane, resulting in the enhanced release of cytochrome c necessary for the activation of caspase-9 that initiates the caspase cascade. On the other hand, apoptotic bodies were rapidly formed from cells treated with AD and CL, but were suppressed when treated with AD and CD. Intracellular membranes and the actin system were reorganized to surround the nuclear fragments in the AD- and CL-treated cells, but such a membrane system was not formed in the presence of CD, implying that the apoptotic bodies are formed via reorganization of intracellular membranes under regulation by actin polymerization. Thus, the cytoskeletal change in CMK-7 cells has a strong effect on the early biochemical process as well as on the later morphologic process in AD-induced apoptosis.

Tryptophan metabolism through the kynurenine pathway in rat brain and liver slices

We hypothesized that hyperbaric oxygen (HBO) enhances tryptophan (TRP) flux through the kynurenine (KYN) pathway because oxygen is a substrate for four pathway enzymes. Our objective was to compare the biosynthesis of KYN pathway intermediates by rat brain and liver slices with air or HBO as the gas phase. One-millimeter thick liver and brain slices were obtained from male Sprague-Dawley rats and incubated individually in chambers containing Hanks'-HEPES- buffer with (3)H-TRP (30 Ci/mmol) for 2 h (37 degrees C) in either room air or oxygen (1.2 or 5.2 atmospheres absolute [ATA] oxygen). After incubation, tissue was snap-frozen and analyzed for protein content while medium was extracted for high-performance liquid chromatography analysis. Radiolabeled nicotinamide adenine dinucleotide (NAD) was produced by brain and liver; liver (with air as the gas phase) also produced quinolinic acid (QA). HBO at 1.2 and 5.2 ATA caused increased QA and NAD from liver slices. HBO did not affect KYN metabolism in brain slices, although there was decreased production of NAD during high oxygen. We conclude that rat brain and liver contain the complete KYN pathway and that HBO enhances KYN flux in liver tissue.

Hydroxyl radicals detected via brain microdialysis in rats breathing air and during hyperbaric oxygen convulsions

Microdialysis was done on 300-400 g, awake, male rats with microdialysis probes inserted through guide cannulas into the striatum (Bregma co-ordinates A 0.5, L 2.9, D -4.0 for guide cannulas implanted 5 days previously). Rats were exposed to hyperbaric oxygen (HBO; 6 atm absolute, 5 atm gauge pressure of oxygen with carbon dioxide absorbed by soda lime). Artificial cerebrospinal fluid (CSF) containing 5 mM sodium salicylate was perfused at 1 microl/min and collected over sequential 10 min intervals with rats breathing air, then HBO, and after decompression. Times to convulsions and duration and severity of convulsions were observed and recorded. CSF samples were analyzed for 2,3- and 2,5-dihydroxybenzoic acid (DHBA), reaction products of hydroxyl radicals with salicylate, by HPLC and compared to authentic standards. Recovery of DHBAs was 48% from fluid surrounding microdialysis probes, based on in vitro tests. The average time to the first convulsion was 21 min and rats convulsed an average of 4 times during 40 min in HBO. There were no significant differences in hydroxyl radical production by this protocol during any of the 10 min collection periods in air or HBO (average in pmoles for 10 microl of all samples: 2,3-DHBA = 7.0 +/- 2.5 and 2,5-DHBA = 11.3 +/- 4.1). The failure to detect an increase in hydroxyl radicals in HBO prior to or during convulsions appears valid since each rat served as its own control.