Injectable composite hydrogels embedded with gallium-based liquid metal particles for solid breast cancer treatment via chemo-photothermal combination

Photothermal therapy (PTT) holds great promise as a cancer treatment modality by generating localized heat at the tumor site. Among various photothermal agents, gallium-based liquid metal (LM) has been widely used as a new photothermal-inducible metallic compound due to its structural transformability. To overcome limitations of random aggregation and dissipation of administrated LM particles into a human body, we developed LM-containing injectable composite hydrogel platforms capable of achieving spatiotemporal PTT and chemotherapy. Eutectic gallium-indium LM particles were first stabilized with 1,2-Distearoyl-sn‑glycero-3-phosphoethanolamine (DSPE) lipids. They were then incorporated into an interpenetrating hydrogel network composed of thiolated gelatin conjugated with 6-mercaptopurine (MP) chemodrug and poly(ethylene glycol)-diacrylate. The resulted composite hydrogel exhibited sufficient capability to induce MDA-MB-231 breast cancer cell death through a multi-step mechanism: (1) hyperthermic cancer cell death due to temperature elevation by near-infrared laser irradiation via LM particles, (2) leakage of glutathione (GSH) and cleavage of disulfide bonds due to destruction of cancer cells. As a consequence, additional chemotherapy was facilitated by GSH, leading to accelerated release of MP within the tumor microenvironment. The effectiveness of our composite hydrogel system was evaluated both in vitro and in vivo, demonstrating significant tumor suppression and killing. These results demonstrate the potential of this injectable composite hydrogel for spatiotemporal cancer treatment. In conclusion, integration of PTT and chemotherapy within our hydrogel platform offers enhanced therapeutic efficacy, suggesting promising prospects for future clinical applications. STATEMENT OF SIGNIFICANCE: Our research pioneers a breakthrough in cancer treatments by developing an injectable hydrogel platform incorporating liquid metal (LM) particle-mediated photothermal therapy and 6-mercaptopurine (MP)-based chemotherapy. The combination of gallium-based LM and MP achieves synergistic anticancer effects, and our injectable composite hydrogel acts as a localized reservoir for specific delivery of both therapeutic agents. This platform induces a multi-step anticancer mechanism, combining NIR-mediated hyperthermic tumor death and drug release triggered by released glutathione from damaged cancer populations. The synergistic efficacy validated in vitro and in vivo studies highlights significant tumor suppression. This injectable composite hydrogel with synergistic therapeutic efficacy holds immense promise for biomaterial-mediated spatiotemporal treatment of solid tumors, offering a potent targeted therapy for triple negative breast cancers.

Corrigendum: Korean Ginseng Berry Extract Enhances the Male Steroidogenesis Enzymes In Vitro and In Vivo

This corrects the article on p. 446 in vol. 41, PMID: 36649918.

Optimized Design of Hyaluronic Acid-Lipid Conjugate Biomaterial for Augmenting CD44 Recognition of Surface-Engineered NK Cells

Triple-negative breast cancer (TNBC) presents treatment challenges due to a lack of detectable surface receptors. Natural killer (NK) cell-based adaptive immunotherapy is a promising treatment because of the characteristic anticancer effects of killing malignant cells directly by secreting cytokines and lytic granules. To maximize the cancer recognition ability of NK cells, biomaterial-mediated ex vivo cell surface engineering has been developed for sufficient cell membrane immobilization of tumor-targeting ligands via hydrophobic anchoring. In this study, we optimized amphiphilic balances of NK cell coating materials composed of CD44-targeting hyaluronic acid (HA)-poly(ethylene glycol) (PEG)-lipid to improve TNBC recognition and the anticancer effect. Changes in the modular design of our material by differentiating hydrophilic PEG length and incorporating lipid amount into HA backbones precisely regulated the amphiphilic nature of HA-PEG-lipid conjugates. The optimized biomaterial demonstrated improved anchoring into NK cell membranes and facilitating the surface presentation level of HA onto NK cell surfaces. This led to enhanced cancer targeting via increasing the formation of immune synapse, thereby augmenting the anticancer capability of NK cells specifically toward CD44-positive TNBC cells. Our approach addresses targeting ability of NK cell to solid tumors with a deficiency of surface tumor-specific antigens while offering a valuable material design strategy using amphiphilic balance in immune cell surface engineering techniques.

Tailoring tumor-recognizable hyaluronic acid-lipid conjugates to enhance anticancer efficacies of surface-engineered natural killer cells

Natural killer (NK) cells have clinical advantages in adoptive cell therapy owing to their inherent anticancer efficacy and their ability to identify and eliminate malignant tumors. However, insufficient cancer-targeting ligands on NK cell surfaces often inhibit their immunotherapeutic performance, especially in immunosuppressive tumor microenvironment. To facilitate tumor recognition and subsequent anticancer function of NK cells, we developed hyaluronic acid (HA, ligands to target CD44 overexpressed onto cancer cells)-poly(ethylene glycol) (PEG, cytoplasmic penetration blocker)-Lipid (molecular anchor for NK cell membrane decoration through hydrophobic interaction) conjugates for biomaterial-mediated ex vivo NK cell surface engineering. Among these major compartments (i.e., Lipid, PEG and HA), optimization of lipid anchors (in terms of chemical structure and intrinsic amphiphilicity) is the most important design parameter to modulate hydrophobic interaction with dynamic NK cell membranes. Here, three different lipid types including 1,2-dimyristoyl-sn-glycero-3-phosphati-dylethanolamine (C14:0), 1,2-distearoyl-sn-glycero-3-phosphatidylethanolamine (DSPE, C18:0), and cholesterol were evaluated to maximize membrane coating efficacy and associated anticancer performance of surface-engineered NK cells (HALipid-NK cells). Our results demonstrated that NK cells coated with HA-PEG-DSPE conjugates exhibited significantly enhanced anticancer efficacies toward MDA-MB-231 breast cancer cells without an off-target effect on human fibroblasts specifically via increased NK cell membrane coating efficacy and prolonged surface duration of HA onto NK cell surfaces, thereby improving HA-CD44 recognition. These results suggest that our HALipid-NK cells with tumor-recognizable HA-PEG-DSPE conjugates could be further utilized in various cancer immunotherapies.

Ex Vivo Peptide Decoration Strategies on Stem Cell Surfaces for Augmenting Endothelium Interaction

Ischemic vascular diseases remain leading causes of disability and death. Although various clinical therapies have been tried, reperfusion injury is a major issue, occurring when blood recirculates at the damaged lesion. As an alternative approach, cell-based therapy has emerged. Mesenchymal stem cells (MSCs) are attractive cellular candidates due to their therapeutic capacities, including differentiation, safety, angiogenesis, and tissue repair. However, low levels of receptors/ligands limit targeted migration of stem cells. Thus, it is important to improve homing efficacy of transplanted MSCs toward damaged endothelium. Among various MSC modulations, ex vivo cell surface engineering could effectively augment homing efficiency by decorating MSC surfaces with alternative receptors/ligands, thereby facilitating intercellular interactions with the endothelium. Especially, exogenous decoration of peptides onto stem cell surfaces could provide appropriate functional signaling moieties to achieve sufficient MSC homing. Based on their protein-like functionalities, high modularity in molecular design, and high specific affinities and multivalency to target receptors, peptides could be representative surface-presentable moieties. Moreover, peptides feature a mild synthetic process, enabling precise control of amino acid composition and sequence. Such ex vivo stem cell surface engineering could be achieved primarily by hydrophobic interactions of the cellular bilayer with peptide-conjugated anchor modules and by covalent conjugation between peptides and available compartments in membranes. To this end, this review provides an overview of currently available peptide-mediated, ex vivo stem cell surface engineering strategies for enhancing MSC homing efficiency by facilitating interactions with endothelial cells. Stem cell surface engineering techniques using peptide-based bioconjugates have the potential to revolutionize current vascular disease treatments while addressing their technical limitations.

Molecular detection of Bartonella and Borrelia in pet dogs in Metro Manila and Laguna, Philippines

Background and Aim

Bartonella and Borrelia are zoonotic vector-borne pathogens that can infect dogs and humans. Data on Bartonella and Borrelia in dogs in the Philippines are lacking. This study was conducted to validate previous reports and further investigate the occurrence of Bartonella and Borrelia spp. in cities of Metro Manila.

Materials and Methods

A total of 182 canine blood samples were acquired with DNA using a commercial extraction kit from selected veterinary clinics in the cities of Metro Manila and Laguna, Philippines. The mammalian actin was amplified through polymerase chain reaction (PCR), followed by PCR assays targeting Bartonella gltA and Borrelia flaB. Further PCR assays targeting 16S of Borrelia and ospA and ospC of Borrelia burgdorferi were performed for those that showed flaB bands.

Results

A positive band for gltA of Bartonella was observed in 9 (4.95%) samples, whereas a positive band for flaB of Borrelia was observed in 15 (8.24%) samples. Subsequent PCR assays for other genes of Borrelia were negative.

Conclusion

These results confirmed the presence of Bartonella and warranted further investigation for the possible presence of other Borrelia species.

Korean Ginseng Berry Extract Enhances the Male Steroidogenesis Enzymes In Vitro and In Vivo

PURPOSE

Testosterone hormonal replacement is the most commonly prescribed solution for men with reproductive issues; however, this treatment has various drawbacks. Hence, the identification of a natural product that promotes steroidogenesis is urgently needed. Ginseng is a popular traditional medicine. This study aimed to investigate steroidogenic effects of Korean ginseng berry extract (GBE; Panax ginseng C.A. Meyer) in vitro and in vivo.

MATERIALS AND METHODS

In vitro model, mouse Leydig cells were treated with varying concentrations of GBE, and the levels of steroidogenesis-related genes and proteins and testosterone were measured using western blotting, qRT-PCR, and enzyme-linked immunosorbent assay (ELISA). Similarly, in an in vivo model using lipopolysaccharide-injected C57BL/6J mice, expression of steroidogenesis-related genes and proteins and testosterone levels were analyzed. Additionally, sleep deprivation was used to simulate common life stressors related to late-onset hypogonadism (LOH) and the natural effects of aging. Mice were fed sham or GBE before being subjected to paradoxical sleep deprivation.

RESULTS

In vitro, GBE induced steroidogenic effects by increasing the levels of enzymes associated with steroidogenesis, steroidogenic acute regulatory protein (STAR), CYP11A1, and CYP17A1. In vivo, GBE significantly increased mRNA and protein levels of steroidogenic enzymes. Furthermore, the synthetic testosterone levels in mouse Leydig cell supernatants and blood sera were increased. In the sleep deprivation study, mice fed GBE showed increased testosterone production and survival under such stressful conditions.

CONCLUSIONS

GBE increased mRNA and protein levels of steroidogenesis-related enzymes STAR, CYP11A1, and CYP17A1. These key enzymes induced the increased production of testosterone both in vivo and in vitro. Thus, GBE might be a promising therapeutic or additive nutritional agent for improving men's health by increasing steroidogenesis or improving LOH.

Current Progress in Gallium-based Liquid Metals for Combinatory Phototherapeutic Anticancer Applications

A variety of therapeutic approaches using liquid metal (LM) have been intensively investigated, due to its unique physico-chemical properties that include high surface tension, fluidity, shape deformability, thermal conductivity, and electrical conductivity. Among a series of LMs, the relatively lower toxicity and minimal volatility of gallium (Ga)-based LMs (GaLMs) enables their usage in a series of potential biomedical applications, especially implantable platforms, to treat multiple diseases. In addition, the highly efficient conversion of light energy into thermal or chemical energy via GaLMs has led to recent developments in photothermal and photodynamic applications for anticancer treatments. As attractive photothermal agents or photosensitizers, a systematic interpretation of the structural characteristics and photo-responsive behaviors of GaLMs is necessary to develop effective anticancer engineering applications. Therefore, the aim of this review is to provide a comprehensive summary of currently suggested GaLM-mediated photo-therapeutic cancer treatments. In particular, the review summarizes (1) surface coating techniques to form stable and multifunctional GaLM particulates, (2) currently investigated GaLM-mediated photothermal and photodynamic anticancer therapies, (3) synergistic efficacies with the aid of additional interventions, and (4) 3D composite gels embedded with GaLMs particles, to convey the potential technological advances of LM in this field.

Association between polycystic ovary syndrome and non-infectious uveitis

Polycystic ovary syndrome (PCOS) is a common endocrine disease in young women. It has been reported that increased proinflammatory cytokines can induce systemic inflammation. However, the association between PCOS and uveitis remains elusive. In this study, we investigate the possible association between PCOS and uveitis using Korean National Health Insurance Service-National Sample Cohort. The incidence of non-infectious uveitis was compared between patients with and without PCOS before and after propensity score matching. Hazard ratios were determined using univariate and multivariate Cox regression models. Of 558,302 female participants, 2039 had PCOS and 8122 had non-infectious uveitis. The incidence of non-infectious uveitis was 35.1 per 10,000 person-years in the PCOS patients compared to 16.6 in non-patients (P < .001). This tendency remained after 1:3 propensity score matching. The hazard ratio of PCOS using a multivariate Cox regression model was 2.79 (95% CI, 1.92-4.05; P < .001) and 2.87 (95% CI, 1.77-4.67; P < .001) before and after matching, respectively. Our results suggests that PCOS is associated with non-infectious uveitis, particularly in women of reproductive age. This may be due to hormonal changes and proinflammatory factors. Future investigations should examine the clinical features and underlying mechanisms.

Voxel-wise adversarial semi-supervised learning for medical image segmentation

BACKGROUND AND OBJECTIVE

Semi-supervised learning for medical image segmentation is an important area of research for alleviating the huge cost associated with the construction of reliable large-scale annotations in the medical domain. Recent semi-supervised approaches have demonstrated promising results by employing consistency regularization, pseudo-labeling techniques, and adversarial learning. These methods primarily attempt to learn the distribution of labeled and unlabeled data by enforcing consistency in the predictions or embedding context. However, previous approaches have focused only on local discrepancy minimization or context relations across single classes.

METHODS

In this paper, we introduce a novel adversarial learning-based semi-supervised segmentation method that effectively embeds both local and global features from multiple hidden layers and learns context relations between multiple classes. Our voxel-wise adversarial learning method utilizes a voxel-wise feature discriminator, which considers multilayer voxel-wise features (involving both local and global features) as an input by embedding class-specific voxel-wise feature distribution. Furthermore, our previous representation learning method is improved by overcoming information loss and learning stability problems, which enables rich representations of labeled data.

RESULT

In the experiments, we used the Left Atrial Segmentation Challenge dataset and the Abdominal Multi-Organ dataset to prove the effectiveness of our method in both single class and multiclass segmentation. The experimental results demonstrate that our method outperforms current best-performing state-of-the-art semi-supervised learning approaches. Our proposed adversarial learning-based semi-supervised segmentation method successfully leveraged unlabeled data to improve the network performance by 2% in Dice score coefficient for multi-organ dataset.

CONCLUSION

We compare our approach to a wide range of medical datasets, and showed our method can be adapted to embed class-specific features. Furthermore, visual interpretation of the feature space demonstrates that our proposed method enables a well-distributed and separated feature space from both labeled and unlabeled data, which improves the overall prediction results.

The telomere maintenance mechanism spectrum and its dynamics in gliomas

Background

The activation of the telomere maintenance mechanism (TMM) is one of the critical drivers of cancer cell immortality. In gliomas, TERT expression and TERT promoter mutation are considered to reliably indicate telomerase activation, while ATRX mutation and/or loss indicates an alternative lengthening of telomeres (ALT). However, these relationships have not been extensively validated in tumor tissues.

Methods

Telomerase repeated amplification protocol (TRAP) and C-circle assays were used to profile and characterize the TMM cross-sectionally (n = 412) and temporally (n = 133) across glioma samples. WES, RNA-seq, and NanoString analyses were performed to identify and validate the genetic characteristics of the TMM groups.

Results

We show through the direct measurement of telomerase activity and ALT in a large set of glioma samples that the TMM in glioma cannot be defined solely by the combination of telomerase activity and ALT, regardless of TERT expression, TERT promoter mutation, and ATRX loss. Moreover, we observed that a considerable proportion of gliomas lacked both telomerase activity and ALT. This telomerase activation-negative and ALT negative group exhibited evidence of slow growth potential. By analyzing a set of longitudinal samples from a separate cohort of glioma patients, we discovered that the TMM is not fixed and can change with glioma progression.

Conclusions

This study suggests that the TMM is dynamic and reflects the plasticity and oncogenicity of tumor cells. Direct measurement of telomerase enzyme activity and evidence of ALT should be considered when defining TMM. An accurate understanding of the TMM in glioma is expected to provide important information for establishing cancer management strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01095-x.

Soluble ACE2 and TMPRSS2 Levels in the Serum of Asthmatic Patients

BACKGROUND

Angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine subtype 2 (TMPRSS2) are key proteins mediating viral entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although gene expressions of ACE2 and TMPRSS2 have been analyzed in various organs and diseases, their soluble forms have been less studied, particularly in asthma. Therefore, we aimed to measure circulating ACE2 and TMPRSS2 in the serum of asthmatics and examine their relationship with clinical characteristics.

METHODS

Clinical data and serum samples of 400 participants were obtained from an asthma cohort. The soluble ACE2 (sACE2) and soluble TMPRSS2 (sTMPRSS2) level was measured by enzyme-linked immunosorbent assay, and the values underwent a natural log transformation. Associations between sACE2 and TMPRSS2 levels and various clinical variables were analyzed.

RESULTS

The patients younger than 70 years old, those with eosinophilic asthma (eosinophils ≥ 200 cells/µL), and inhaled corticosteroids (ICS) non-users were associated with higher levels of sACE2. Blood eosinophils and fractionated exhaled nitric oxide levels were positively correlated with serum ACE2. In contrast, lower levels of sTMPRSS2 were noted in patients below 70 years and those with eosinophilic asthma, while no association was noted between ICS use and sTMPRSS2. The level of sTMPRSS2 also differed according to sex, smoking history, coexisting hypertension, and forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio. The proportion of sputum neutrophils was positively correlated with sTMPRSS2, while the FEV1/FVC ratio reported a negative correlation with sTMPRSS2.

CONCLUSION

The levels of ACE2 and TMPRSS2 were differently expressed according to age, ICS use, and several inflammatory markers. These findings suggest variable susceptibility and prognosis of SARS-CoV-2 infection among asthmatic patients.

Voxel-level Siamese Representation Learning for Abdominal Multi-Organ Segmentation

BACKGROUND AND OBJECTIVE

Recent works in medical image segmentation have actively explored various deep learning architectures or objective functions to encode high-level features from volumetric data owing to limited image annotations. However, most existing approaches tend to ignore cross-volume global context and define context relations in the decision space. In this work, we propose a novel voxel-level Siamese representation learning method for abdominal multi-organ segmentation to improve representation space.

METHODS

The proposed method enforces voxel-wise feature relations in the representation space for leveraging limited datasets more comprehensively to achieve better performance. Inspired by recent progress in contrastive learning, we suppressed voxel-wise relations from the same class to be projected to the same point without using negative samples. Moreover, we introduce a multi-resolution context aggregation method that aggregates features from multiple hidden layers, which encodes both the global and local contexts for segmentation.

RESULTS

Our experiments on the multi-organ dataset outperformed the existing approaches by 2% in Dice score coefficient. The qualitative visualizations of the representation spaces demonstrate that the improvements were gained primarily by a disentangled feature space.

CONCLUSION

Our new representation learning method successfully encoded high-level features in the representation space by using a limited dataset, which showed superior accuracy in the medical image segmentation task compared to other contrastive loss-based methods. Moreover, our method can be easily applied to other networks without using additional parameters in the inference.

Chemokine Expression during Adipogenesis and Inflammation in Orbital Fibroblasts from Patients with Graves' Orbitopathy

Purpose

Chemokines are involved in the pathogenesis of various autoimmune diseases, including Graves' orbitopathy (GO), but comprehensive analyses of the dynamics of these cytokines and their receptors in such diseases remain lacking. In this study, we investigated the expressions of chemokines and their receptors during adipogenesis and inflammation in primary cultured orbital fibroblasts from patients with GO.

Methods

The messenger RNA (mRNA) expression levels of chemokines were compared between GO (n = 6) and non-GO (n = 5) orbital tissues by real-time polymerase chain reaction. After adipogenesis was induced in primary cultured orbital fibroblasts from patients with GO (n =5) and following stimulation with interleukin (IL)-1β and tumor necrosis factor (TNF)-α, the mRNA expression levels of chemokines and their receptors were analyzed.

Results

Chemokines were significantly downregulated in GO orbital tissues compared to non-GO orbital tissues (p < 0.05). Adipogenesis resulted in a strong increase in mRNA expression levels of chemokines and their receptors at an early stage (day 1); however, expression levels started to decrease thereafter and, eventually, decreased to below basal levels at the end of adipogenesis (day 10). Following stimulation with IL-1β and TNF-α, the mRNA expression levels of chemokines and their receptors increased, showing different responses to various proinflammatory cytokines.

Conclusions

Chemokines were strongly upregulated in the early phase of adipogenesis before decreasing continuously until the end of adipogenesis. Also, overt mature GO tissues showed reduced mRNA expression of chemokines compared to controls, which might indicate the existence of a shorter window for effective medical inflammatory treatment. The heightened levels of chemokines and their receptors observed after stimulation with IL-1β and TNF-α suggest a crucial role of proinflammatory cytokines in the pathogenesis of GO and, further, support the idea that chemokines could be used as biomarkers of GO activity.

Absolute quantification of tumor-infiltrating immune cells in high-grade glioma identifies prognostic and radiomics values

PURPOSE

To understand the tumor immune microenvironment precisely, it is important to secure the quantified data of tumor-infiltrating immune cells, since the immune cells are true working unit. We analyzed unit immune cell number per unit volume of core tumor tissue of high-grade gliomas (HGG) to correlate their immune microenvironment characteristics with clinical prognosis and radiomic signatures.

METHODS

The number of tumor-infiltrating immune cells from 64 HGG core tissue were analyzed using flow cytometry and standardized. After sorting out patient groups according to diverse immune characteristics, the groups were tested if they have any clinical prognostic relevance and specific radiomic signature relationships. Sparse partial least square with discriminant analysis using multimodal magnetic resonance images was employed for all radiomic classifications.

RESULTS

The median number of CD45 + cells per one gram of HGG core tissue counted 865,770 cells which was equivalent to 8.0% of total cells including tumor cells. There was heterogeneity in the distribution of immune cell subpopulations among patients. Overall survival was significantly better in T cell-deficient group than T cell-enriched group (p = 0.019), and T8 dominant group than T4 dominant group (p = 0.023). The number of tumor-associated macrophages (TAM) and M2-TAM was significantly decreased in isocitrate dehydrogenase mutated HGG. Radiomic signature classification showed good performance in predicting immune phenotypes especially with features extracted from apparent diffusion coefficient maps.

CONCLUSIONS

Absolute quantification of tumor-infiltrating immune cells confirmed the heterogeneity of immune microenvironment in HGG which harbors prognostic impact. This immune microenvironment could be predicted by radiomic signatures non-invasively.

Individual tooth detection and identification from dental panoramic X-ray images via point-wise localization and distance regularization

Dental panoramic X-ray imaging is a popular diagnostic method owing to its very small dose of radiation. For an automated computer-aided diagnosis system in dental clinics, automatic detection and identification of individual teeth from panoramic X-ray images are critical prerequisites. In this study, we propose a point-wise tooth localization neural network by introducing a spatial distance regularization loss. The proposed network initially performs center point regression for all the anatomical teeth (i.e., 32 points), which automatically identifies each tooth. A novel distance regularization penalty is employed on the 32 points by considering L₂ regularization loss of Laplacian on spatial distances. Subsequently, teeth boxes are individually localized using a multitask neural network on a patch basis. A multitask offset training is employed on the final output to improve the localization accuracy. Our method successfully localizes not only the existing teeth but also missing teeth; consequently, highly accurate detection and identification are achieved. The experimental results demonstrate that the proposed algorithm outperforms state-of-the-art approaches by increasing the average precision of teeth detection by 15.71 % compared to the best performing method. The accuracy of identification achieved a precision of 0.997 and recall value of 0.972. Moreover, the proposed network does not require any additional identification algorithm owing to the preceding regression of the fixed 32 points regardless of the existence of the teeth.

Inhibition of MUC1 exerts cell-cycle arrest and telomerase suppression in glioblastoma cells

Mucin 1 (MUC1) is a transmembrane glycoprotein involved in tumorigenesis of diverse cancers. However, the role of MUC1 in glioblastoma (GBM) has not yet been fully explored. In this study, the anticancer mechanism of MUC1 suppression in GBM was investigated. The expression level of MUC1 was analyzed in human glioma and paired normal brain tissues. MUC1 was overexpressed in GBM and was negatively associated with overall survival. Moreover, we silenced MUC1 to investigate its effect in GBM cell lines and found that knockdown of MUC1 inhibited cell proliferation and resulted in cell cycle arrest at G1 phase. MUC1 silencing decreased the phosphorylation of RB1 and increased the expression of CDKN1B. Gene set enrichment analysis showed that a series of genes related to cell cycle, telomere maintenance and transforming growth factor Beta (TGF-β) signaling in epithelial mesenchymal transition (EMT) were influenced by MUC1 knockdown. Notably, the reduced TERT expression levels combined with impaired telomerase activity and the switching of telomere maintenance mechanism to alternative lengthening of telomeres (ALT) were observed after MUC1 knockdown. Our results support the role of MUC1 in oncological process in GBM which can be developed as a therapeutic target for cell cycle control and telomere maintenance mechanism.

Envelopes in multivariate regression models with nonlinearity and heteroscedasticity

Envelopes have been proposed in recent years as a nascent methodology for sufficient dimension reduction and efficient parameter estimation in multivariate linear models. We extend the classical definition of envelopes in Cook et al. (2010) to incorporate a nonlinear conditional mean function and a heteroscedastic error. Given any two random vectors ${X}\in\mathbb{R}^{p}$ and ${Y}\in\mathbb{R}^{r}$, we propose two new model-free envelopes, called the martingale difference divergence envelope and the central mean envelope, and study their relationships to the standard envelope in the context of response reduction in multivariate linear models. The martingale difference divergence envelope effectively captures the nonlinearity in the conditional mean without imposing any parametric structure or requiring any tuning in estimation. Heteroscedasticity, or nonconstant conditional covariance of ${Y}\mid{X}$, is further detected by the central mean envelope based on a slicing scheme for the data. We reveal the nested structure of different envelopes: (i) the central mean envelope contains the martingale difference divergence envelope, with equality when ${Y}\mid{X}$ has a constant conditional covariance; and (ii) the martingale difference divergence envelope contains the standard envelope, with equality when ${Y}\mid{X}$ has a linear conditional mean. We develop an estimation procedure that first obtains the martingale difference divergence envelope and then estimates the additional envelope components in the central mean envelope. We establish consistency in envelope estimation of the martingale difference divergence envelope and central mean envelope without stringent model assumptions. Simulations and real-data analysis demonstrate the advantages of the martingale difference divergence envelope and the central mean envelope over the standard envelope in dimension reduction.

Pharmacogenomic Analysis Reveals CCNA2 as a Predictive Biomarker of Sensitivity to Polo-Like Kinase I Inhibitor in Gastric Cancer

Despite recent innovations and advances in early diagnosis, the prognosis of advanced gastric cancer remains poor due to a limited number of available therapeutics. Here, we employed pharmacogenomic analysis of 37 gastric cancer cell lines and 1345 small-molecule pharmacological compounds to investigate biomarkers predictive of cytotoxicity among gastric cancer cells to the tested drugs. We discovered that expression of CCNA2, encoding cyclin A2, was commonly associated with responses to polo-like kinase 1 (PLK1) inhibitors (BI-2536 and volasertib). We also found that elevated CCNA2 expression is required to confer sensitivity to PLK1 inhibitors through increased mitotic catastrophe and apoptosis. Further, we demonstrated that CCNA2 expression is elevated in KRAS mutant gastric cancer cell lines and primary tumors, resulting in an increased sensitivity to PLK1 inhibitors. Our study suggests that CCNA2 is a novel biomarker predictive of sensitivity to PLK1 inhibitors for the treatment of advanced gastric cancer, particularly cases carrying KRAS mutation.

Testing conditional mean independence for functional data

We propose a new nonparametric conditional mean independence test for a response variable $Y$ and a predictor variable $X$ where either or both can be function-valued. Our test is built on a new metric, the so-called functional martingale difference divergence, which fully characterizes the conditional mean dependence of $Y$ given $X$ and extends the martingale difference divergence proposed by Shao & Zhang (2014). We define an unbiased estimator of functional martingale difference divergence by using a $\mathcal{U}$-centring approach, and we obtain its limiting null distribution under mild assumptions. Since the limiting null distribution is not pivotal, we use the wild bootstrap method to estimate the critical value and show the consistency of the bootstrap test. Our test can detect the local alternative which approaches the null at the rate of $n^{-1/2}$ with a nontrivial power, where $n$ is the sample size. Unlike the three tests developed by Kokoszka et al. (2008), Lei (2014) and Patilea et al. (2016), our test does not require a finite-dimensional projection or assume a linear model, and it does not involve any tuning parameters. Promising finite-sample performance is demonstrated via simulations, and a real-data illustration is used to compare our test with existing ones.

SURG-05. EXPERIENCE PROFILING OF FLUORESCENCE-GUIDED SURGERY FOR GLIOMAS

Numerous studies reported a usefulness of 5-ALA fluorescence-guided surgery (FGS) in high grade gliomas. However, fluorescence pattern and intensity is variable among gliomas. In this study, we report our extensive experiences of FGS in various gliomas focusing on epidemiological data of fluorescence pattern. A total of 827 histologically proven glioma patients out of 900 brain tumor patients who had undergone FGS using 5-ALA during the period of 8.5 years between July 2010 and January 2019 were analyzed. Indication for FGS in glioma surgery harbored any evidence of possible high-grade foci at presumed gliomas in preoperative magnetic resonance images (MRI). Among the 827 gliomas, the number of cases corresponding to 2016 World Health Organization (WHO) grade IV, III, II, and I are 528 (58.7%), 193 (21.4%), 87 (9.7%) and 19 (2.1%), respectively. In terms of fluorescence rate, grade IV gliomas showed positive fluorescence in 95.4% of cases including strong intensity in 85.6%. Grade III gliomas showed fluorescence in about half of cases (55.0%), while 45.0% of cases did not show any fluorescence. Anaplastic oligodendroglioma had more positive rate (63.9%) than anaplastic astrocytoma (46.2%). Both grade II and I gliomas still showed positive fluorescence in about one-fourths of cases (24.1% and 26.3%, respectively). Among them ependymoma and pilocytic astrocytoma were fluorescence-prone tumors. This epidemiological data of 5-ALA fluorescence in various grades of gliomas provides fundamental reference to clinical application of FGS using 5-ALA in glioma surgery.

A pilot evaluation of an advocacy programme on knowledge, empowerment, family-school partnership and parent well-being

BACKGROUND

Internationally, it has been recognised that parents need to advocate for their children with disabilities to receive services. However, many parents find advocacy difficult because of systemic and logistical barriers. As such, parents of children with disabilities may seek a special education advocate to help them understand their child's rights and secure services. Yet little research has been conducted about programmes to develop special education advocates.

METHODS

In this study, we conducted a comparison study to determine the association of an advocacy programme (i.e. the Volunteer Advocacy Project) on a primary outcome (i.e. special education knowledge) and other outcomes (i.e. family-school partnership, empowerment and parent well-being). Specifically, in 2017, 34 participants, all mothers of children with disabilities, were recruited from disability organisations in the USA. Seventeen mothers participated in the intervention group (i.e. the advocacy training), while 17 mothers participated in the wait list control group. The Volunteer Advocacy Project is a 36 hr advocacy training for individuals to gain instrumental and affective knowledge to advocate for their own children with disabilities and for other families. All participants completed a pre-survey and post-survey; only intervention group participants completed a 6-month follow-up survey.

RESULTS

Compared with 17 wait list control group participants, the 17 intervention group participants demonstrated improvements in special education knowledge, P = 0.002, η²  = 0.32, and self-mastery, P = 0.04, η²  = 0.15, and decreases in the quality of family-school partnerships, P = 0.002, η²  = 0.32. At the follow-up survey, intervention group participants demonstrated increases in empowerment, P = 0.04, η²  = 0.29, and special education knowledge, P = 0.02, η²  = 0.38.

CONCLUSIONS

Implications for research including the need for a randomised controlled trial are discussed; also, practitioners need to evaluate advocacy training programmes regarding their effectiveness.

Abstract GS4-05: Dose escalated simultaneous integrated boost radiotherapy for women treated by breast conservation surgery for early breast cancer: 3-year adverse effects in the IMPORT HIGH trial (CRUK/06/003)

Background

IMPORT HIGH is a randomised, multi-centre phase III trial testing dose escalated simultaneous integrated boost (SIB) against sequential boost each delivered by intensity modulated radiotherapy (IMRT) for early stage breast cancer with higher risk of local relapse. The primary endpoint was initially breast induration at 3 years, requiring 840 patients; accrual was extended (target 2568) with the new primary endpoint of local relapse. We report adverse effects (AE) at 3 years.

Methods

Women age ≥18 after breast conservation surgery for pT1-3 pN0-pN3a M0 invasive carcinoma were eligible. Randomisation was 1:1:1 between 40Gy/15F to whole breast (WB) + 16Gy/8F sequential photon boost to tumour bed (40+16Gy), 36Gy/15F to WB, 40Gy to partial breast + 48Gy (48Gy) or + 53Gy (53Gy) in 15F SIB to tumour bed. AEs were assessed annually by clinicians in all patients and in a planned sub-set (840) of patients by photographs at 3 years and by patients at 6 months, 1 and 3 years. AE scores were dichotomised as none/mild vs marked for photographs and none/mild vs moderate/marked for patients and clinicians. Fisher's exact tests compared groups; principal comparison (protocol-specified) between 53Gy and 48Gy (p&lt;0.01 defined as statistical significance).

Results

2617 women consented between 03/2009 and 09/2015 from 39 UK radiotherapy centres. Median follow-up was 49.1 (IQR 36.8-63.2) months. Median age was 49 (IQR 44-56); 9%, 38% & 53% were tumour grade 1, 2 & 3 respectively; 30% were node positive. 66% received chemotherapy and 73% endocrine therapy. 3-year AE data were available for 2017 clinician assessments, 641 photographs and 842 patient assessments. Proportions of patients with marked AEs were low overall. Rates of moderate/marked AEs at 3 years were broadly similar between the randomised groups; with a suggestion of a slightly increased risk for breast induration in 53Gy compared with control (borderline significance).

AE at 3 years 40+16Gy n(%)48Gy n(%)53Gy n(%)ClinicianBreast induration;N656668654None451 (69)483 (72)445 (68)Mild167 (25)141 (21)146 (22)Moderate32 (5)42 (6)56 (9)Marked6 (1)2 (1)7 (1)P-value 0.57010.0102  0.0443Breast shrinkage;N655669654None442 (68)472 (71)448 (69)Mild167 (26)161 (24)166 (25)Moderate40 (6)33 (5)35 (5)Marked6 (1)3 (1)5 (1)P-value 0.25410.5772  0.6373Breast distortion;N656669654None451 (69)464 (69)442 (68)Mild169 (26)170 (25)170 (26)Moderate33 (5)32 (5)38 (6)Marked3 (1)3 (1)4 (1)P-value 0.90310.4862  0.4113PatientChange in breast appearance;N287264285None38 (13)50 (19)58 (20)Mild164 (57)151 (57)142 (50)Moderate57 (20)45 (17)54 (19)Marked28 (10)18 (7)31 (11)P-value 0.14910.9992  0.1243PhotographChange in breast appearance;N218210213None183 (84)185 (88)177 (83)Mild25 (11)23 (11)32 (15)Marked10 (5)2 (1)4 (2)P-value 0.03610.1732  0.6853148Gy v 40+16Gy; 253Gy v 40+16Gy; 353Gy v 48Gy

Conclusions

These results represent the largest and most mature reported AE outcomes of breast SIB within a clinical trial. At 3 years, rates of moderate/marked AEs were similar between SIB IMRT and WB + sequential boost IMRT delivered over 3 and 4.5 weeks respectively.

Citation Format: Coles CE, Griffin CL, Kirby AM, Haviland JS, Titley JC, Benstead K, Brunt AM, Chan C, Ciurlionis L, Din OS, Donovan EM, Eaton DJ, Harnett AN, Hopwood P, Jefford ML, Jenkins PJ, Lee CE, McCormack M, Sherwin L, Syndikus I, Tsang Y, Twyman NI, Ventikaraman R, Wickers S, Wilcox MH, Bliss JM, Yarnold JR. Dose escalated simultaneous integrated boost radiotherapy for women treated by breast conservation surgery for early breast cancer: 3-year adverse effects in the IMPORT HIGH trial (CRUK/06/003) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS4-05.

Steroidogenic effects of Taraxacum officinale extract on the levels of steroidogenic enzymes in mouse Leydig cells

In this study, we investigated the steroidogenic effect of Taraxacum officinale extract on mouse TM3 Leydig cells, which produce male hormones by increasing the levels of steroidogenic enzymes. Steroidogenic enzymes are involved in the production of testosterone in the testis. To date, the steroidogenic effect of T. officinale has not been reported. Therefore, we examined the steroidogenic effects of T. officinale extract (TOE) on mouse Leydig cells in vitro. Traditionally, plants have been used for the treatment of various kinds of ailments. For many years, some medicinal plants have been used to regulate steroidogenesis or late-onset hypogonadism (LOH). In particular, plants belonging to the genus Taraxacum have anti-inflammatory, anti-nociceptive, anti-oxidant, and anti-cancer properties. In this study, we determined whether the TOE exerts steroidogenic effects by increasing the levels of enzymes associated with steroidogenesis, such as the steroidogenic acute regulatory protein (STAR), CYP11A1, and translocator protein (TSPO) in the mitochondria and CYP17A1 in the smooth endoplasmic reticulum, in mouse Leydig cells. Our results showed that the TOE significantly increased the mRNA and protein levels of steroidogenic enzymes, thereby increasing the testosterone levels in mouse Leydig cells. Thus, our results indicate that the TOE increases the levels of steroidogenic enzymes, and further studies are required to establish the potential of this plant in regulating steroidogenesis and improving LOH.

The particle size dependence of the oxygen reduction reaction for carbon-supported platinum and palladium

Model carbon supported Pt and Pd electrocatalysts have been prepared using a high-throughput physical vapor deposition method. For Pt, metal particle sizes are controlled between 1.5-5.5 nm over 100 electrodes of an electrochemical screening chip, allowing the oxygen reduction reaction (ORR) activity of the catalysts to be determined simultaneously. The ORR-specific current density is observed to increase with increasing particle diameter up to approximately 4 nm, at which point the activity begins to level off. The reduction in ORR activity for particles below 4 nm is accompanied by a concomitant increase in the overpotential for surface reduction. The resulting mass activity exhibits a maximum for particles with diameters of approximately 3.5 nm. These results are consistent with results published recently for high area carbon-supported Pt catalysts. For Pd particles, both the specific current density and the mass-specific activity for the ORR are observed to increase with increasing particle diameter, with no distinct optimum observed. The implications for the optimization of Pt- or Pd-based ORR catalysts for proton exchange membrane fuel cell (PEMFC) applications are discussed.

A comprehensive bone-health management approach for men with prostate cancer receiving androgen deprivation therapy

For advanced and metastatic prostate cancer, androgen deprivation therapy (adt) is the mainstay of treatment. Awareness of the potential bone-health complications consequent to adt use is increasing. Many studies have shown that prolonged adt leads to significant bone loss and increased fracture risk that negatively affect quality of life. Clinical practice guidelines for preserving bone health in men with prostate cancer on adt vary across Canada. This paper reviews recent studies on bone health in men with prostate cancer receiving adt and the current evidence regarding bone-health monitoring and management in reference to Canadian provincial guidelines. Based on this narrative review, we provide general bone-health management recommendations for men with prostate cancer receiving adt.

Effect of repeated public releases on cesarean section rates

OBJECTIVES

Public release of and feedback (here after public release) on institutional (clinics and hospitals) cesarean section rates has had the effect of reducing cesarean section rates. However, compared to the isolated intervention, there was scant evidence of the effect of repeated public releases (RPR) on cesarean section rates. The objectives of this study were to evaluate the effect of RPR for reducing cesarean section rates.

METHODS

From January 2003 to July 2007, the nationwide monthly institutional cesarean section rates data (1,951,303 deliveries at 1194 institutions) were analyzed. We used autoregressive integrated moving average (ARIMA) time-series intervention models to assess the effect of the RPR on cesarean section rates and ordinal logistic regression model to determine the characteristics of the change in cesarean section rates.

RESULTS

Among four RPR, we found that only the first one (August 29, 2005) decreased the cesarean section rate (by 0.81 percent) and continued to have an impact period through the last observation in May 2007. Baseline cesarean section rates (OR, 4.7; 95% CI, 3.1 to 7.1) and annual number of deliveries (OR, 2.8; 95% CI, 1.6 to 4.7) of institutions in the upper third of each category at before first intervention had a significant contribution to the decrease of cesarean section rates.

CONCLUSIONS

We could not found the evidence that RPR has had the significant effect of reducing cesarean section rates. Institutions with upper baseline cesarean section rates and annual number of deliveries were more responsive to RPR.

Isolation of the first three cases of Clostridium difficile polymerase chain reaction ribotype 027 in Singapore

INTRODUCTION

The incidence of Clostridium (C.) difficile infection (CDI) was on the rise from 2001 to 2006 in Singapore. Recent unpublished data suggests that its incidence had remained stable or decreased in most local public hospitals between 2006 and 2010. It is, however, not known if the polymerase chain reaction (PCR) ribotype 027 strains have been circulating, although reports suggest that this strain is emerging in Asia, with the first cases reported from Japan in 2007, as well as in Hong Kong and Australia in 2009. We initiated a culture-based surveillance to detect this epidemic strain in Singapore.

METHODS

From September 2008 to December 2009, all non-duplicate toxin-positive stool samples from the three largest public hospitals in Singapore were collected for culture and further analysis.

RESULTS

Out of the 366 samples collected, 272 viable isolates were cultured. Of these, 240 tested toxin-positive and ten tested positive for the binary toxin gene; 35 different PCR ribotypes were found. Three isolates that tested positive for binary toxin contained the same PCR ribotyping pattern as the C. difficile 027 control strain. All three had the 18-bp deletion and single nucleotide tcdC deletion at position 117. Susceptibility testing was performed, demonstrating susceptibility to erythromycin and moxifloxacin.

CONCLUSION

We report the first three isolates of C. difficile 027 from Singapore. However, their susceptibility patterns are more consistent with the historical 027 strains. Rising CDI incidence may not be associated with the emergence of the epidemic 027 strain at this time.

[The change in readmission rate, length of stay and hospital charge after performance reporting of hip hemiarthroplasty]

OBJECTIVES

We assessed impact of performance reporting information about the readmission rate, length of stay and cost of hip hemiarthroplasty.

METHODS

The data are from a nationwide claims database, National Quality Improvement Project database, of Health Insurance Review & Assessment Service in Korea. From January 2006 to April 2008, we received information of length of stay, readmission within 30 days, cost of 22 851 hip hemiarthroplasty episodes. Each episodes has retained the diagnoses of comorbidities and demographics. We used time-series analysis to assess the shifting of patients selections, between high volume(over 16 operations in a year) and low volume institutions, after performance reporting (december 2007). The changes of quality (readmission, length of stay) and cost were evaluated by multilevel analysis with adjustment of patient's factors and institutional factors after performance reporting.

RESULTS

As compared with the before performance reporting, the proportion of patients who choose the high volume institution, increased 3.45% and the trends continued 4 months at marginal significance (p=0.059). After performance reporting, national average readmission rate, length of stay were decreased by 0.49 OR (95% CI=0.25-0.95) and 10% (β=-0.102 p<0.01) and cost was not changed (β=-0.01, p<0.27). The high volume institutions were more decreased than low volume in length of stay.

CONCLUSIONS

After performance reporting, readmission rate, length of stay were decreased and the patient selections were marginal shifted from low volume institutions to high volume institutions.

Characterization of Kiss1 neurons using transgenic mouse models

Humans and mice with loss-of-function mutations of the genes encoding kisspeptins (Kiss1) or kisspeptin receptor (Kiss1r) are infertile due to hypogonadotropic hypogonadism. Within the hypothalamus, Kiss1 mRNA is expressed in the anteroventral periventricular nucleus (AVPV) and the arcuate nucleus (Arc). In order to better study the different populations of kisspeptin cells we generated Kiss1-Cre transgenic mice. We obtained one line with Cre activity specifically within Kiss1 neurons (line J2-4), as assessed by generating mice with Cre-dependent expression of green fluorescent protein or β-galactosidase. Also, we demonstrated Kiss1 expression in the cerebral cortex and confirmed previous data showing Kiss1 mRNA in the medial nucleus of amygdala and anterodorsal preoptic nucleus. Kiss1 neurons were more concentrated towards the caudal levels of the Arc and higher leptin-responsivity was observed in the most caudal population of Arc Kiss1 neurons. No evidence for direct action of leptin in AVPV Kiss1 neurons was observed. Melanocortin fibers innervated subsets of Kiss1 neurons of the preoptic area and Arc, and both populations expressed melanocortin receptors type 4 (MC4R). Specifically in the preoptic area, 18-28% of Kiss1 neurons expressed MC4R. In the Arc, 90% of Kiss1 neurons were glutamatergic, 50% of which also were GABAergic. In the AVPV, 20% of Kiss1 neurons were glutamatergic whereas 75% were GABAergic. The differences observed between the Kiss1 neurons in the preoptic area and the Arc likely represent neuronal evidence for their differential roles in metabolism and reproduction.

Antiphospholipid syndrome with pulmonary artery embolism and multiple venous thromboses

We report a case of a 21-year-old university student with underlying lupus nephritis who presented with recurrent symptoms of fever, haemoptysis, and pleuritic chest pain. CT pulmonary angiogram confirmed pulmonary embolism in the right subsegmental pulmonary arteries. One week later, she developed left renal vein and left common iliac vein thromboses, with new emboli in the left subsegmental pulmonary arteries. We hereforth discuss the diagnostic issues of a patient with systemic lupus erythematosus (SLE) on corticosteroids therapy, and also treatment of the antiphospholipid syndrome.

Clinical experiences of digital model surgery and the rapid-prototyped wafer for maxillary orthognathic surgery

OBJECTIVE

The aim of this study was to present our clinical experience regarding the production and accuracy of digitally printed wafers for maxillary movement during the bimaxillary orthognathic surgery.

STUDY DESIGN

Fifty-five consecutive patients requiring maxillary orthognathic surgery were included in this study. The plan for digital model surgery (DMS) was dictated by the surgical plans for each clinical case. We carried out digital model mounting, DMS, wafer printing, and confirmation of the accuracy of the procedure.

RESULTS

Moving the reference points to the target position in DMS involved a mean error of 0.00-0.09 mm. The mean errors confirmed by the model remounting procedure with the printed wafer by DMS were 0.18-0.40 mm (for successful cases; n = 42) and 0.03-1.04 mm (for poor cases; n = 3).

CONCLUSION

The accuracies of the wafers by DMS were similar to those for wafers produced by manual model surgery, although they were less accurate than those produced by DMS alone. The rapid-prototyped interocclusal wafer produced with the aid of DMS can be an alternative procedure for maxillary orthognathic surgery.

Solitary fibrous tumour of the pleura presenting with refractory non-insulin mediated hypoglycaemia (the Doege-Potter syndrome)

We report a case of a 61 year-old man who presented with refractory non-insulin mediated hypoglycaemia. A chest radiograph showed a right lung opacity, which was confirmed as a large intra-thoracic mass by computed tomography (CT) of the thorax. CT-guided biopsy with histological examination revealed features of a solitary fibrous tumour of low malignant potential. We discuss the association of solitary fibrous tumour of the pleura (SFTP) with hypoglycaemia, and the management of such rare tumours.

Human Plasmodium knowlesi infections in Klang Valley, Peninsula Malaysia: a case series

We report seven cases of naturally acquired human Plasmodium knowlesi infections which were admitted to our centre from July 2007 till June 2008. Diagnosis was confirmed by nested PCR. Cases of P. knowlesi infections, dubbed the fifth type of human malaria, have been reported in East Malaysia (Sabah and Sarawak) as well as in the state of Pahang in Peninsula Malaysia. These seven patients appear to be the first few reported cases of P. knowlesi infection in the Klang valley, Peninsula Malaysia. We then discuss the characteristics of human P. knowlesi infections, which include its natural hosts, responsible vectors, clinical presentation, and the treatment of such infections.

Subclavian artery stent fracture

We report a case of a 52 year-old dentist who had stent implantation for a left subclavian artery stenosis. However, this was later complicated by a stent fracture within one week of stent placement. A chest radiograph showed two pieces of the fractured stent, which was confirmed by computed tomographic angiogram (CTA) of the affected artery. We then discuss the occurrence of stent fractures, which are not uncommon but serious complications of endovascular therapy.

Cytokine-mediated induction of anti-apoptotic genes that are linked to nuclear factor kappa-B (NF-kappaB) signalling in human islets and in a mouse beta cell line

AIMS/HYPOTHESIS

The destruction of pancreatic beta cells leading to type 1 diabetes in humans is thought to occur mainly through apoptosis and necrosis induced by activated macrophages and T cells, and in which secreted cytokines play a significant role. The transcription factor nuclear factor kappa-B (NF-kappaB) plays an important role in mediating the apoptotic action of cytokines in beta cells. We therefore sought to determine the changes in expression of genes modulated by NF-kappaB in human islets exposed to a combination of IL1beta, TNF-alpha and IFN-gamma.

METHODS

Microarray and gene set enrichment analysis were performed to investigate the global response of gene expression and pathways modulated in cultured human islets exposed to cytokines. Validation of a panel of NF-kappaB-regulated genes was performed by quantitative RT-PCR. The mechanism of induction of BIRC3 by cytokines was examined by transient transfection of BIRC3 promoter constructs linked to a luciferase gene in MIN6 cells, a mouse beta cell line.

RESULTS

Enrichment of several metabolic and signalling pathways was observed in cytokine-treated human islets. In addition to the upregulation of known pro-apoptotic genes, a number of anti-apoptotic genes including BIRC3, BCL2A1, TNFAIP3, CFLAR and TRAF1 were induced by cytokines through NF-kappaB. Significant synergy between the cytokines was observed in NF-kappaB-mediated induction of the promoter of BIRC3 in MIN6 cells.

CONCLUSIONS/INTERPRETATION

These findings suggest that, via NF-kappaB activation, cytokines induce a concurrent anti-apoptotic pathway that may be critical for preserving islet integrity and viability during the progression of insulitis in type 1 diabetes.

Grb2 dominantly associates with dynamin II in human hepatocellular carcinoma HepG2 cells

The two SH3 domains and one SH2 domain containing adaptor protein Grb2 is an essential element of the Ras signaling pathway in multiple systems. The SH2 domain of Grb2 recognizes and interacts with phosphotyrosine residues on activated tyrosine kinases, whereas the SH3 domains bind to several proline-rich domain-containing proteins such as Sos1. To define the difference in Grb2-associated proteins in hepatocarcinoma cells, we performed coprecipitation analysis using recombinant GST-Grb2 fusion proteins and found that several protein components (p170, p125, p100, and p80) differently associated with GST-Grb2 proteins in human Chang liver and hepatocarcinoma HepG2 cells. Sos1 and p80 proteins dominantly bind to Grb2 fusion proteins in Chang liver, whereas p100 remarkably associate with Grb2 in HepG2 cells. Also GST-Grb2 SH2 proteins exclusively bound to the p46(Shc), p52(Shc), and p66(Shc) are important adaptors of the Ras pathway in HepG2 cells. The p100 protein has been identified as dynamin II. We observed that the N-SH3 and C-SH3 domains of Grb2 fusion proteins coprecipitated with dynamin II besides Sos1. These results suggest that dynamin II may be a functional molecule involved in Grb2-mediated signaling pathway on Ras activation for tumor progression and differentiation of hepatocarcinoma cells.

Orexin (hypocretin) neurons contain dynorphin

Orexins (also called hypocretins) are peptide neurotransmitters expressed in neurons of the lateral hypothalamic area (LHA). Mice lacking the orexin peptides develop narcolepsy-like symptoms, whereas mice with a selective loss of the orexin neurons develop hypophagia and severe obesity in addition to the narcolepsy phenotype. These different phenotypes suggest that orexin neurons may contain neurotransmitters besides orexin that regulate feeding and energy balance. Dynorphin neurons are common in the LHA, and dynorphin has been shown to influence feeding; hence, we studied whether dynorphin and orexin are colocalized. In rats, double-label in situ hybridization revealed that nearly all (94%) neurons expressing prepro-orexin mRNA also expressed prodynorphin mRNA. The converse was also true: 96% of neurons in the LHA containing prodynorphin mRNA also expressed prepro-orexin mRNA. Double-label immunohistochemistry confirmed that orexin-A and dynorphin-A peptides were highly colocalized in the LHA. Wild-type mice and orexin knock-out mice showed abundant prodynorphin mRNA-expressing neurons in the LHA, but orexin/ataxin-3 mice with a selective loss of the orexin neurons completely lacked prodynorphin mRNA in this area, further confirming that within the LHA, dynorphin expression is restricted to the orexin neurons. These findings suggest that dynorphin-A may play an important role in the function of the orexin neurons.

Differential expression of orexin receptors 1 and 2 in the rat brain

Orexins (hypocretins) are neuropeptides synthesized in the central nervous system exclusively by neurons of the lateral hypothalamus. Orexin-containing neurons have widespread projections and have been implicated in complex physiological functions including feeding behavior, sleep states, neuroendocrine function, and autonomic control. Two orexin receptors (OX(1)R and OX(2)R) have been identified, with distinct expression patterns throughout the brain, but a systematic examination of orexin receptor expression in the brain has not appeared. We used in situ hybridization histochemistry to examine the patterns of expression of mRNA for both orexin receptors throughout the brain. OX(1)R mRNA was observed in many brain regions including the prefrontal and infralimbic cortex, hippocampus, paraventricular thalamic nucleus, ventromedial hypothalamic nucleus, dorsal raphe nucleus, and locus coeruleus. OX(2)R mRNA was prominent in a complementary distribution including the cerebral cortex, septal nuclei, hippocampus, medial thalamic groups, raphe nuclei, and many hypothalamic nuclei including the tuberomammillary nucleus, dorsomedial nucleus, paraventricular nucleus, and ventral premammillary nucleus. The differential distribution of orexin receptors is consistent with the proposed multifaceted roles of orexin in regulating homeostasis and may explain the unique role of the OX(2)R receptor in regulating sleep state stability.

An unliganded thyroid hormone receptor causes severe neurological dysfunction

Congenital hypothyroidism and the thyroid hormone (T(3)) resistance syndrome are associated with severe central nervous system (CNS) dysfunction. Because thyroid hormones are thought to act principally by binding to their nuclear receptors (TRs), it is unexplained why TR knock-out animals are reported to have normal CNS structure and function. To investigate this discrepancy further, a T(3) binding mutation was introduced into the mouse TR-beta locus by homologous recombination. Because of this T(3) binding defect, the mutant TR constitutively interacts with corepressor proteins and mimics the hypothyroid state, regardless of the circulating thyroid hormone concentrations. Severe abnormalities in cerebellar development and function and abnormal hippocampal gene expression and learning were found. These findings demonstrate the specific and deleterious action of unliganded TR in the brain and suggest the importance of corepressors bound to TR in the pathogenesis of hypothyroidism.

Characterization of CART neurons in the rat and human hypothalamus

Cocaine- and amphetamine-regulated transcript (CART) is a recently described neuropeptide widely expressed in the rat brain. CART mRNA and peptides are found in hypothalamic sites such as the paraventricular nucleus (PVH), the supraoptic nucleus (SON), the lateral hypothalamic area (LHA), the dorsomedial nucleus of the hypothalamus (DMH), the arcuate nucleus (Arc), the periventricular nucleus (Pe), and the ventral premammillary nucleus (PMV). Intracerebroventricular administration of recombinant CART peptide decreases food intake and CART mRNA levels in the Arc are regulated by leptin. Leptin administration induces Fos expression in hypothalamic CART neurons in the PVH, the DMH, the Arc, and the PMV. In the current study, we used double label in situ hybridization histochemistry to investigate the potential direct action of leptin on hypothalamic CART neurons and to define the chemical identity of the hypothalamic CART neurons in the rat brain. We found that CART neurons in the Arc, DMH, and PMV express long form leptin-receptor mRNA, and the suppressor of cytokine signaling-3 (SOCS-3) mRNA after an acute dose of intravenous leptin. We also found that CART neurons in the parvicellular PVH, in the DMH and in the posterior Pe coexpress thyrotropin-releasing hormone (TRH) mRNA. CART neurons in the magnocellular PVH and in the SON coexpress dynorphin (DYN), and CART cell bodies in the LHA and in the posterior Pe coexpress melanin-concentrating hormone (MCH) and glutamic acid decarboxylase (GAD-67) mRNA. In the Arc, a few CART neurons coexpress neurotensin (NT) mRNA. In addition, we examined the distribution of CART immunoreactivity in the human hypothalamus. We found CART cell bodies in the PVH, in the SON, in the LHA, in the Arc (infundibular nucleus) and in the DMH. We also observed CART fibers throughout the hypothalamus, in the bed nucleus of the stria terminalis, and in the amygdala. Our results indicate that leptin directly acts on CART neurons in distinct nuclei of the rat hypothalamus. Furthermore, hypothalamic CART neurons coexpress neuropeptides involved in energy homeostasis, including MCH, TRH, DYN, and NT. The distribution of CART cell bodies and fibers in the human hypothalamus indicates that CART may also play a role in the regulation of energy homeostasis in humans.

Interleukin-4 induces two distinct GAS-binding complexes containing STAT6: evidence for DNA binding of STAT6 monomer

Treatment of tonsillar mononuclear cells with interleukin-4 (IL-4) rapidly induced the formation of two distinct complexes upon reaction of the cell extracts with the IL-4-responsive element (IL-4RE) of the CD23b promoter in the electrophoretic mobility sift assays (EMSA). The two complexes were detected with a similar activation kinetics upon IL-4 stimulation. They were both immunoreactive with antibodies to signal transducer and activator of transcription (STAT) 6. The upper complex, however, appeared more stable in the competitor oligomer binding assays and more resistant in the anti-phosphotyrosine antibody inhibition assays than the lower complex. Western blot analysis revealed a single peptide of 105 kDa reacting with anti-STAT6 antibodies, which ruled out the possibility for multiple isoforms of STAT6 in these cells. Subsequently, Southwestern analysis demonstrated that monomeric STAT6 in the IL-4-treated nuclear extract can bind the labeled IL-4RE in an activation-dependent manner. Our data strongly suggests that in addition to dimeric STAT6, monomeric STAT6, albeit with a lower affinity, can bind the IL-4RE/gamma activation site (GAS) upon IL-4-induced activation. Also, the upper and lower bands observed in EMSA are likely to represent dimeric and monomeric STAT6 bound to the IL-4RE oligomer, respectively. The functional implication of the STAT6 monomer binding to GAS in the IL-4-induced gene activation is discussed.

Self-reports and clinician-measured physical function among patients with low back pain: a comparison

OBJECTIVE

To determine the relationships among self-reported activity limitation and clinician-measured functional performance tests.

DESIGN

Case series survey.

SETTING

A referral-based orthopedic spine clinic in Houston, TX.

PATIENTS

Eighty-three patients (48 women, 35 men) with low back pain (LBP).

INTERVENTIONS

The Roland-Morris Disability Questionnaire (RMDQ) and a physical performance test (PPT) battery.

MAIN OUTCOME MEASURES

Self-reported activity limitation (eg, walking, bending, getting out of chair, putting on sock, doing heavy jobs) was assessed by the RMDQ. Clinician-measured functional performance was assessed with the PPT, a battery comprised 6 tests: lumbar flexion range of motion, a 50-foot walk at fastest speed, a 5-minute walk, 5 repetitions of sit-to-stand, 10 repetitions of trunk flexion, and loaded reach task (patients reached forward while holding a weight weighing 5% of their body weight).

RESULTS

Pearson's product-moment correlations between total RMDQ score and each of the performance tests ranged from.29 to.41. Point biserial correlations between individual RMDQ items and their corresponding performance tests were slightly lower, ranging from.20 to.33.

CONCLUSION

There were moderate correlations between self-reported activity limitation and corresponding clinician-measured performance tests. The unique perspective each method provides appears to be useful for a comprehensive understanding of physical function in patients with LBP.

Global phylogeography of a cryptic copepod species complex and reproductive isolation between genetically proximate "populations"

The copepod Eurytemora affinis has a broad geographic range within the Northern Hemisphere, inhabiting coastal regions of North America, Asia, and Europe. A phylogenetic approach was used to determine levels of genetic differentiation among populations of this species, and interpopulation crosses were performed to determine reproductive compatibility. DNA sequences from two mitochondrial genes, large subunit (16S) rRNA (450 bp) and cytochrome oxidase I (COI, 652 bp), were obtained from 38 populations spanning most of the species range and from two congeneric species, E. americana and E. herdmani. Phylogenetic analysis revealed a polytomy of highly divergent clades with maximum sequence divergences of 10% in 16S rRNA and 19% in COI. A power test (difference of a proportion) revealed that amount of sequence data collected was sufficient for resolving speciation events occurring at intervals greater than 300,000 years, but insufficient for determining whether speciation events were approximately simultaneous. Geographic and genetic distances were not correlated (Mantel's test; r = 0.023, P = 0.25), suggesting that populations had not differentiated through gradual isolation by distance. At finer spatial scales, there was almost no sharing of mtDNA haplotypes among proximate populations, indicating little genetic exchange even between nearby sites. Interpopulation crosses demonstrated reproductive incompatibility among genetically distinct populations, including those that were sympatric. Most notably, two geographically distant (4000 km) but genetically proximate (0.96% 16S, 0.15% COI) populations exhibited asymmetric reproductive isolation at the F2 generation. Large genetic divergences and reproductive isolation indicate that the morphologically conservative E. affinis constitutes a sibling species complex. Reproductive isolation between genetically proximate populations underscores the importance of using multiple measures to examine patterns of speciation.

IFN-gamma and IFN-alpha posttranscriptionally down-regulate the IL-4-induced IL-4 receptor gene expression

As Th1 and Th2 cytokines, IFN-gamma/alpha and IL-4 counterregulate diverse immune functions. In particular, IFN-gamma and IFN-alpha have been reported to markedly suppress the IL-4-induced IgE production and type II IgE receptor (FcepsilonRII/CD23) expression. Because modulation of IL-4R may be an important mechanism in the regulation of IL-4 response, we have investigated the effect of IFN-gamma/alpha on IL-4R expression and signal transduction mechanisms involved in this process. In human mononuclear cells and B cells isolated from tonsil or peripheral blood, IL-4 up-regulates IL-4R(alpha) expression at surface protein and mRNA levels, and the IL-4-induced IL-4R(alpha) is significantly down-regulated by both IFN-gamma and IFN-alpha to a similar extent. The inhibitory effects of IFN-gamma/alpha on the IL-4R mRNA expression require a lag period of about 8 h, and are sensitive to cycloheximide treatment, which suggests that the suppressive effect of IFNs on IL-4R gene expression is a secondary response requiring de novo synthesis of IFN-induced factors. Under such conditions that the inhibitory effects of IFNs are observed, IFNs do not affect the IL-4-induced STAT6 activation and IL-4R transcription, as analyzed by EMSA and nuclear run-on assays, respectively. Subsequently, mRNA stability studies have indicated that the action of IFN-gamma/alpha is primarily mediated by an accelerated decay of IL-4-induced IL-4R mRNA. Thus, it appears that, as already shown in the case of the IL-4-induced FcepsilonRII regulation, posttranscriptional inhibition of IL-4-inducible genes by mRNA destabilization is a common mechanism by which type I and II IFNs antagonize the IL-4 response in human immune cells.