Ca2Lib: Simple and Accurate LiDAR-RGB Calibration Using Small Common Markers

Modern visual perception techniques often rely on multiple heterogeneous sensors to achieve accurate and robust estimates. Knowledge of their relative positions is a mandatory prerequisite to accomplish sensor fusion. Typically, this result is obtained through a calibration procedure that correlates the sensors' measurements. In this context, we focus on LiDAR and RGB sensors that exhibit complementary capabilities. Given the sparsity of LiDAR measurements, current state-of-the-art calibration techniques often rely on complex or large calibration targets to resolve the relative pose estimation. As such, the geometric properties of the targets may hinder the calibration procedure in those cases where an ad hoc environment cannot be guaranteed. This paper addresses the problem of LiDAR-RGB calibration using common calibration patterns (i.e., A3 chessboard) with minimal human intervention. Our approach exploits the flatness of the target to find associations between the sensors' measurements, leading to robust features and retrieval of the solution through nonlinear optimization. The results of quantitative and comparative experiments with other state-of-the-art approaches show that our simple schema performs on par or better than existing methods that rely on complex calibration targets.

Single-Stage Bilateral Reverse Shoulder Arthroplasty for a Bilateral Four-Part Fracture Dislocation of the Proximal Humerus in an Elderly Patient: A Case Report

Proximal humerus fractures (PHFs) are a common type of fracture in adults. Although PHFs are common, bilateral presentation is extremely rare. Most PHFs are treated conservatively. In this report, we describe a 69-year-old right-hand-dominant male patient who was involved in a high-impact motor vehicle accident (MVA). The patient's upper limbs were in a fully extended position while he was holding the driving wheel, where he sustained a side impaction to the car by a hard object that caused bilateral four-part PHF with dislocation, which was confirmed on radiological investigations. The orthopedic surgery team believed that surgical treatment was necessary and ideal for these bilateral fracture dislocations, specifically bilateral reverse total shoulder arthroplasty (RTSA). This is due to multiple factors, including the risk of humeral head avascular necrosis (AVN), the patient's advanced age, low demand, poor bone stock, osteoporosis, and a non-fixable fracture pattern. The patient underwent a single-stage bilateral RTSA procedure, which was well tolerated. He was optimized postoperatively. The post-operative X-ray showed good and satisfactory implant positions and orientation. Functional assessment using the Constant-Murley Score (CMS) and Disabilities of the Arm, Shoulder and Hand (DASH) score were calculated at three-months follow-up (right-left: 50-60 and 41-14, respectively), at five-months follow-up (right-left: 34-66 and 38-14, respectively), and at eight-months follow-up (right-left: 40-68 and 24-7.5, respectively). Follow-up X-rays revealed good tuberosities healing, and no loosening or scapular notching. In addition, pain was assessed on a numerical rating scale (NRS), which demonstrated fast pain relief. Short-term follow-up with the patient demonstrated that he was satisfied with the surgery, especially the left side with a pain score on the NRS of one. We selected to share our experience of this complex case with our peers in the field of orthopedic surgery worldwide so that such a procedure could be implemented in similar cases to ensure satisfactory outcomes following bilateral four-part PHF with dislocation.

HDACi-dependent Microenvironmental Normalization Overcomes Tumor Burden-induced T-cell Exhaustion

PURPOSE

T-cell exhaustion limits immunotherapy for the treatment of solid tumors. Although immune checkpoint blockade and adoptive T-cell therapy (ACT) can mediate tumor regression, their potency is often determined by tumor burden. Here, we identified tumor burden-related pathway changes that are conducive to T-cell exhaustion. We then determined whether microenvironmental reprogramming via epigenetic modulation could reverse T-cell exhaustion and improve immunotherapeutic responsiveness.

EXPERIMENTAL DESIGN

We developed a murine syngeneic tumor model wherein an increased burden ablated therapeutic responsiveness to ACT, which corresponded with systemic induction of T-cell exhaustion. Transcriptome analysis of these large tumors allowed us to characterize changes to immunosuppressive pathway expression during class I histone deacetylase inhibitor MS-275 treatment. We then measured the therapeutic impact of MS-275 during ACT and assessed T-cell exhaustion by transcriptome/phenotypic analysis.

RESULTS

ACT durably regressed small tumors but failed to control large tumors, which were associated with systemic T-cell exhaustion and ablation of T-cell responses. Large tumors were defined by an immunosuppressive pathway signature. MS-275 reversed this pathway signature and promoted durable regression of large tumors during ACT. Prototypical exhaustion marker Tim-3 was selectively upregulated in transferred T cells despite displaying a reduced exhaustion signature. Instead, we observed enhanced activation-dependent signaling correlating with enrichment of the IL2-STAT5 signaling axis. Activated CD8+ T-cell responses were predominantly skewed toward terminal effector cell-like CD44+ Tim-3hi TCF1- CD127- KLRG1+ differentiation.

CONCLUSIONS

Tumor burden-induced pathway changes can be reversed through epigenetic reprogramming, enabling the conversion from T-cell exhaustion to effector lineage differentiation.

AR activates YAP/TAZ differentially in prostate cancer

The Hippo signalling pathway is a master regulator of cell growth, proliferation, and cancer. The transcriptional coregulators of the Hippo pathway, YAP and TAZ, are central in various cancers. However, how YAP and TAZ get activated in most types of cancers is not well understood. Here, we show that androgens activate YAP/TAZ via the androgen receptor (AR) in prostate cancer (PCa), and that this activation is differential. AR regulates YAP translation while inducing transcription of the TAZ encoding gene, WWTR1 Furthermore, we show that AR-mediated YAP/TAZ activation is regulated by the RhoA GTPases transcriptional mediator, serum response factor (SRF). Importantly, in prostate cancer patients, SRF expression positively correlates with TAZ and the YAP/TAZ target genes CYR61 and CTGF We demonstrate that YAP/TAZ are not essential for sustaining AR activity, however, targeting YAP/TAZ or SRF sensitize PCa cells to AR inhibition in anchorage-independent growth conditions. Our findings dissect the cellular roles of YAP, TAZ, and SRF in prostate cancer cells. Our data emphasize the interplay between these transcriptional regulators and their roles in prostate tumorigenesis and highlight how these insights might be exploited therapeutically.

Oncolytic BHV-1 Is Sufficient to Induce Immunogenic Cell Death and Synergizes with Low-Dose Chemotherapy to Dampen Immunosuppressive T Regulatory Cells

Immunogenic cell death (ICD) can switch immunologically "cold" tumors "hot", making them sensitive to immune checkpoint inhibitor (ICI) therapy. Many therapeutic platforms combine multiple modalities such as oncolytic viruses (OVs) and low-dose chemotherapy to induce ICD and improve prognostic outcomes. We previously detailed many unique properties of oncolytic bovine herpesvirus type 1 (oBHV) that suggest widespread clinical utility. Here, we show for the first time, the ability of oBHV monotherapy to induce bona fide ICD and tumor-specific activation of circulating CD8⁺ T cells in a syngeneic murine model of melanoma. The addition of low-dose mitomycin C (MMC) was necessary to fully synergize with ICI through early recruitment of CD8⁺ T cells and reduced infiltration of highly suppressive PD-1⁺ Tregs. Cytokine and gene expression analyses within treated tumors suggest that the addition of MMC to oBHV therapy shifts the immune response from predominantly anti-viral, as evidenced by a high level of interferon-stimulated genes, to one that stimulates myeloid cells, antigen presentation and adaptive processes. Collectively, these data provide mechanistic insights into how oBHV-mediated therapy modalities overcome immune suppressive tumor microenvironments to enable the efficacy of ICI therapy.

YAP/TAZ activation predicts clinical outcomes in mesothelioma and is conserved in in vitro model of driver mutations

The Hippo signalling pathway is dysregulated across a wide range of cancer types and, although driver mutations that directly affect the core Hippo components are rare, a handful is found within pleural mesothelioma (PM). PM is a deadly disease of the lining of the lung caused by asbestos exposure. By pooling the largest-scale clinical datasets publicly available, we here interrogate associations between the most prevalent driver mutations within PM and Hippo pathway disruption in patients, while assessing correlations with a variety of clinical markers. This analysis reveals a consistent worse outcome in patients exhibiting transcriptional markers of YAP/TAZ activation, pointing to the potential of leveraging Hippo pathway transcriptional activation status as a metric by which patients may be meaningfully stratified. Preclinical models recapitulating disease are transformative in order to develop new therapeutic strategies. We here establish an isogenic cell-line model of PM, which represents the most frequently mutated genes and which faithfully recapitulates the molecular features of clinical PM. This preclinical model is developed to probe the molecular basis by which the Hippo pathway and key driver mutations affect cancer initiation and progression. Implementing this approach, we reveal the role of NF2 as a mechanosensory component of the Hippo pathway in mesothelial cells. Cellular NF2 loss upon physiological stiffnesses analogous to the tumour niche drive YAP/TAZ-dependent anchorage-independent growth. Consequently, the development and characterisation of this cellular model provide a unique resource to obtain molecular insights into the disease and progress new drug discovery programs together with future stratification of PM patients.

A Combination of Chemotherapy and Oncolytic Virotherapy Sensitizes Colorectal Adenocarcinoma to Immune Checkpoint Inhibitors in a cDC1-Dependent Manner

Immune checkpoint therapy has shown great promise in the treatment of cancers with a high mutational burden, such as mismatch repair-deficient colorectal carcinoma (dMMR CRC). However, many patients fail to respond to immune checkpoint therapy. Using a mouse model of dMMR CRC, we demonstrated that tumors can be further sensitized to immune checkpoint therapy by using a combination of low-dose chemotherapy and oncolytic HSV-1. This combination induced the infiltration of CD8+ and CD4+ T cells into the tumor and the upregulation of gene signatures associated with the chemoattraction of myeloid cell subsets. When combined with immune checkpoint therapy, the combination promoted the infiltration of activated type 1 conventional dendritic cells (cDC1s) into the tumor. Furthermore, we found this combination strategy to be dependent on cDC1s, and its therapeutic efficacy to be abrogated in cDC1-deficient Batf3-/- mice. Thus, we demonstrated that the adjuvanticity of dMMR CRCs can be improved by combining low-dose chemotherapy and oncolytic HSV-1 in a cDC1-dependent manner.

Label2label: Training a neural network to selectively restore cellular structures in fluorescence microscopy

Immunofluorescence microscopy is routinely used to visualise the spatial distribution of proteins that dictates their cellular function. However, unspecific antibody binding often results in high cytosolic background signals, decreasing the image contrast of a target structure. Recently, convolutional neural networks (CNNs) were successfully employed for image restoration in immunofluorescence microscopy, but current methods cannot correct for those background signals. We report a new method that trains a CNN to reduce unspecific signals in immunofluorescence images; we name this method label2label (L2L). In L2L, a CNN is trained with image pairs of two non-identical labels that target the same cellular structure. We show that after L2L training a network predicts images with significantly increased contrast of a target structure, which is further improved after implementing a multiscale structural similarity loss function. Here, our results suggest that sample differences in the training data decrease hallucination effects that are observed with other methods. We further assess the performance of a cycle generative adversarial network, and show that a CNN can be trained to separate structures in superposed immunofluorescence images of two targets.

Summary: Label2label is a new deep learning-based image restoration method that reduces cytosolic background signals in immunofluorescence images of cellular structures.

Response to FEC Chemotherapy and Oncolytic HSV-1 Is Associated with Macrophage Polarization and Increased Expression of S100A8/A9 in Triple Negative Breast Cancer

Simple Summary

We have previously reported that a combination of clinical chemotherapies and oncolytic HSV-1 works to sensitize tumors to respond to immune checkpoint blockade. We further showed that this therapeutic platform worked via the upregulation of B cells and the concomitant control of immunosuppressive myeloid cells. In this manuscript, we sought to further dissect the mechanism of myeloid cell regulation and differentiation and to identify a therapeutically driven gene signature that is associated with the switch in the myeloid phenotype. This work not only impacts triple-negative breast cancer but all solid tumor phenotypes as we aim to better understand the underlying immunology associated with responses to immune checkpoint therapies in these typically refractory disease types.

Abstract

The era of immunotherapy has seen an insurgence of novel therapies driving oncologic research and the clinical management of the disease. We have previously reported that a combination of chemotherapy (FEC) and oncolytic virotherapy (oHSV-1) can be used to sensitize otherwise non-responsive tumors to immune checkpoint blockade and that tumor-infiltrating B cells are required for the efficacy of our therapeutic regimen in a murine model of triple-negative breast cancer. In the studies herein, we have performed gene expression profiling using microarray analyses and have investigated the differential gene expression between tumors treated with FEC + oHSV-1 versus untreated tumors. In this work, we uncovered a therapeutically driven switch of the myeloid phenotype and a gene signature driving increased tumor cell killing.

Immune checkpoint blockade in triple negative breast cancer influenced by B cells through myeloid-derived suppressor cells

Triple negative breast cancer holds a dismal clinical outcome and as such, patients routinely undergo aggressive, highly toxic treatment regimens. Clinical trials for TNBC employing immune checkpoint blockade in combination with chemotherapy show modest prognostic benefit, but the percentage of patients that respond to treatment is low, and patients often succumb to relapsed disease. Here, we show that a combination immunotherapy platform utilizing low dose chemotherapy (FEC) combined with oncolytic virotherapy (oHSV-1) increases tumor-infiltrating lymphocytes, in otherwise immune-bare tumors, allowing 60% of mice to achieve durable tumor regression when treated with immune checkpoint blockade. Whole-tumor RNA sequencing of mice treated with FEC + oHSV-1 shows an upregulation of B cell receptor signaling pathways and depletion of B cells prior to the start of treatment in mice results in complete loss of therapeutic efficacy and expansion of myeloid-derived suppressor cells. Additionally, RNA sequencing data shows that FEC + oHSV-1 suppresses genes associated with myeloid-derived suppressor cells, a key population of cells that drive immune escape and mediate therapeutic resistance. These findings highlight the importance of tumor-infiltrating B cells as drivers of antitumor immunity and their potential role in the regulation of myeloid-derived suppressor cells.

Functional Analysis of Tumor-Infiltrating Myeloid Cells by Flow Cytometry and Adoptive Transfer

The tumor-infiltrating myeloid cell compartment represents a heterogeneous population of broadly immunosuppressive cells that have been exploited by the tumor to support its growth. Their accumulation in tumor and secondary lymphoid tissue leads to the suppression of antitumor immune responses and is thus a target for therapeutic intervention. As it is known that the local cytokine milieu can dictate the functional programming of tumor-infiltrating myeloid cells, strategies have been devised to manipulate the tumor microenvironment (TME) to express a cytokine landscape more conducive to antitumor myeloid cell activity. To evaluate therapy-induced changes in tumor-infiltrating myeloid cells, this paper will outline the procedure to dissociate intradermal/subcutaneous tumor tissue from solid tumor-bearing mice in preparation for leukocyte recovery. Strategies for flow cytometric analysis will be provided to enable the identification of heterogeneous myeloid populations within isolated leukocytes and the characterization of unique myeloid phenotypes. Lastly, this paper will describe a means of purifying viable myeloid cells for functional assays and determining their therapeutic value in the context of adoptive transfer.

Link N suppresses interleukin-1β-induced biological effects on human osteoarthritic cartilage

Osteoarthritis (OA) is a disease of diarthrodial joints associated with extracellular matrix proteolytic degradation under inflammatory conditions, pain and disability. Currently, there is no therapy to prevent, reverse or modulate the disease course. The present study aimed at evaluating the regenerative potential of Link N (LN) in human OA cartilage in an inflammatory milieu and determining if LN could affect pain-related behaviour in a knee OA mouse injury model. Osteo-chondro OA explants and OA chondrocytes were treated with LN in the presence of interleukin-1β (IL-1β) to simulate an osteoarthritic environment. Quantitative von Frey polymerase chain reaction and Western blotting were performed to determine the effect of LN on matrix protein synthesis, catabolic enzymes, cytokines and nerve growth factor expression. Partial medial meniscectomy (PMM) was performed on the knee of C57BL/6 mice and, 12 weeks post-surgery, mice were given a 5 µg intra-articular injection of LN or phosphate-buffered saline. A von Frey test was conducted over 24 h to measure the mechanical allodynia in the hind paw. LN modulated proteoglycan and collagen synthesis in human OA cartilage through inhibition of IL-1β-induced biological effects. LN also supressed IL-1β-induced upregulation of cartilage-degrading enzymes and inflammatory molecules in OA chondrocytes. Upon investigation of the canonical signalling pathways IL-1β and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), LN resulted to significantly inhibit NF-κB activation in a dose-dependent manner. In addition, LN suppressed mechanical allodynia in an OA PMM mouse model. Results supported the concept that LN administration could provide therapeutic potential in OA.

The Hippo Pathway in Prostate Cancer

Despite recent efforts, prostate cancer (PCa) remains one of the most common cancers in men. Currently, there is no effective treatment for castration-resistant prostate cancer (CRPC). There is, therefore, an urgent need to identify new therapeutic targets. The Hippo pathway and its downstream effectors—the transcriptional co-activators, Yes-associated protein (YAP) and its paralog, transcriptional co-activator with PDZ-binding motif (TAZ)—are foremost regulators of stem cells and cancer biology. Defective Hippo pathway signaling and YAP/TAZ hyperactivation are common across various cancers. Here, we draw on insights learned from other types of cancers and review the latest advances linking the Hippo pathway and YAP/TAZ to PCa onset and progression. We examine the regulatory interaction between Hippo-YAP/TAZ and the androgen receptor (AR), as main regulators of PCa development, and how uncontrolled expression of YAP/TAZ drives castration resistance by inducing cellular stemness. Finally, we survey the potential therapeutic targeting of the Hippo pathway and YAP/TAZ to overcome PCa.

Short-term side effects and patient-reported outcomes of bleomycin sclerotherapy in vascular malformations

BACKGROUND

Vascular malformations (VM) are congenital lesions that can be debilitating and cause significant aesthetic and functional limitations. The chemotherapeutic agent bleomycin has been utilized as a sclerosant, directly injected percutaneously into the VM. Unfortunately, little is known about the benefits and short-term side effects of bleomycin with intralesional injections.

PROCEDURE

An IRB approved, retrospective chart review was performed on patients with VM who had been treated with intralesional bleomycin. Data included type of VM, number of treatments, total bleomycin dose per m², and adverse effects. A questionnaire was administered to available patients to assess subjective outcomes and side effects.

RESULTS

Forty-six patients were treated with 141 procedures of bleomycin sclerotherapy for VM. Patient ages ranged from 1 to 20 years (median age 10 years). The median cumulative bleomycin dose was 16.3 units/m²/person (range of 1.7-97.0 units/m²/person). Sixty-three percent of patients were reached for a questionnaire to assess short-term side effects. Ninety percent of patients surveyed were satisfied to very satisfied with the results from the procedure. About 24% of patients experienced transient nausea, vomiting and/or local hyperpigmentation.

CONCLUSION

Bleomycin sclerotherapy can be an effective treatment of VM with repeat exposure with minor risk of short-term side effects, however, long-term risks are of great concern. Further studies are required to assess systemic absorption and long-term risks.

Addictive behaviors among psychiatric outpatients

Introduction

Little is known about the epidemiology of smoking and substance use disorders (SUD) among psychiatric outpatients in south of Tunisia.

Objective

Examine the prevalence of smoking and SUD among adult psychiatric outpatients at the regional hospital of Gabes.

Method

A survey was conducted to assess the extent of alcohol abuse, drug abuse and smoking among adult psychiatric outpatients (n = 115), with different psychiatric diagnoses (DSM−5), aged over 18 years, following the psychiatric department of the regional hospital of Gabes. Data collection was done through a semi-structured interview with the patient and a family member + review of medical records. SUD was defined as an abuse or dependence to alcohol or drug.

Results

Smokers account for 29.6% of the patients. Smoking was significantly higher in male patients (97.1% vs. 43.2%, P < 10−3). Compared to nonsmokers, smokers patients had significantly more the diagnosis of schizophrenia (64.7% vs. 35.3%, P = 0.004), a higher level of education (52.9% vs. 32.1%, P = 0.03), a higher rate of alcohol (14.7% vs. 1.2%, P = 0.008) and drug use disorders (8.8% vs. 0%, P = 0.02), and a higher rate of relapses (3.5 vs. 2, P = 0.004). Alcohol use was noted in 6% of patients and cannabis in 4%. Patients with a SUD had significantly more the diagnosis of schizophrenia (100% vs. 36.2%, P = 0.05), a higher rate of smoking (100% vs. 27.7%, P = 0.02). Financial situation, education, marital status and age of onset of the disease were not associated with SUD.

Conclusion

Addictive behaviors are prevalent among psychiatric outpatients. This has implications in treatment and management of these patients.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Associations between gender and obesity among adults psychiatric outpatients in the town of Gabes (Tunisia)

Background

Patients with severe mental illness (SMI) suffer from two to three times higher rates of obesity, and this has translated into much higher rates of obesity-related morbidity and premature mortality in this population.

Aims

Measuring the frequency of obesity and its associations with gender, and others socio-demographics factors among 115 adults psychiatric outpatients.

Methods

A cross-sectional study, was conducted to assess frequency of obesity among 115 adults attending public mental health department in the regional hospital of Gabes (south of Tunisia). For the diagnosis of mental disorders, we used the diagnostic and statistical manual of mental disorders (DSM-V). Obesity was estimated by body mass index (BMI). This index is defined as the ratio of weight (kg) to squared size (m2). Overweight is defined as a BMI between 25 and 29.9 kg/m2 and obesity by a BMI ≥30 kg/m2. BMI was measured directly and other information was gathered by interview.

Results

The mean BMI was 25. In our patients, 40.9% were overweight, 49.6% (n = 57) were obese including 8.7% (n = 10) who were morbidly obese. Obesity was significantly more frequent in women (63.8% vs 39.7%, P = 0.009), living in a couple (60.9% vs 42%, P = 0.03) and having a medium or high socioeconomic level (53.3% vs 30.4%, P = 0.03). There were no differences between obese and non-obese regarding age, level of education and professional status.

Conclusion

The high prevalence of obesity among women suggests that targeted approaches are needed to promote optimal physical health in this population.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

The highly expressed 5'isomiR of hsa-miR-140-3p contributes to the tumor-suppressive effects of miR-140 by reducing breast cancer proliferation and migration

Background

miRNAs are small noncoding RNA molecules that play an important role in post-transcriptional regulation of gene expression. Length and/or sequence variants of the same miRNA are termed isomiRs. While most isomiRs are functionally redundant compared to their canonical counterparts, the so-called 5’isomiRs exhibit a shifted 5’ end and therefore a shifted seed sequence resulting in a different target spectrum. However, not much is known about the functional relevance of these isoforms.

Results

Analysis of miRNA-seq data from breast cancer cell lines identified six pairs of highly expressed miRNAs and associated 5’isomiRs. Among them, hsa-miR-140-3p was of particular interest because its 5’isomiR showed higher expression compared to the canonical miRNA annotated in miRbase. This miRNA has previously been shown to control stemness of breast cancer cells. miRNAseq data of breast cancer patients (TCGA dataset) showed that both the canonical hsa-miR-140-3p and its 5’isomiR-140-3p were highly expressed in patients’ tumors compared to normal breast tissue. In the current work, we present the functional characterization of 5’isomiR-140-3p and the cellular phenotypes associated with its overexpression in MCF10A, MDA-MB-468 and MDA-MB-231 cell lines in comparison to the canonical hsa-miR-140-3p. Contrary to the effect of the canonical hsa-miR-140-3p, overexpression of the 5’isomiR-140-3p led to a decrease in cell viability. The latter observation was supported by cell cycle analysis, where the 5’isomiR-140-3p but not the hsa-miR-140-3p caused cell cycle arrest in G₀/G₁-phase. Additionally, 5’ismoiR-140-3p overexpression was found to cause a decrease in cell migration in the three cell lines. We identified three novel direct target genes of the 5’isomiR-140-3p; COL4A1, ITGA6 and MARCKSL1. Finally, we have shown that knocking down these genes partially phenocopied the effects of the 5’isomiR-140-4p overexpression, where COL4A1 and ITGA6 knockdown led to reduced cell viability and cell cycle arrest, while MARCKSL1 knockdown resulted in a decrease in the migratory potential of cells.

Conclusions

In summary, this work presents evidence that there is functional synergy between the canonical hsa-miR-140-3p and the newly identified 5’isomiR-140-3p in suppressing growth and progression of breast cancer by simultaneously targeting genes related to differentiation, proliferation, and migration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2869-x) contains supplementary material, which is available to authorized users.

Development of a Large Animal Long-Term Intervertebral Disc Organ Culture Model That Includes the Bony Vertebrae for Ex Vivo Studies

Intervertebral disc (IVD) degeneration is a common cause of low back pain. Testing potential therapeutics in the regeneration of the disc requires the use of model systems. Although several animal models have been developed to investigate IVD degeneration, they are technically challenging to prepare, expensive, present with limitations when performing biomechanical studies on the disc, and are impractical in large-scale screening of novel anabolic and scaffolding agents. An IVD organ culture system offers an inexpensive alternative. In the current paradigm, the bony endplates are removed to allow for nutrient diffusion and maintenance of disc cell viability. Although this is an excellent system for testing biologics, it results in concave cartilage endplates and, as such, requires special platens for loading purposes in a bioreactor as flat ones can overload the annular disc region leading to improper loading. Furthermore, the absence of bone makes it unsuitable for applying complex cyclic loading, a topic of interest in the study of chronic progressive degeneration, as multiaxial loading is more representative of daily forces encountered by the IVD. We have developed and validated a novel long-term IVD organ culture model that retains vertebral bone and is easy to prepare. Our model is ideal for testing potential drugs and alternate-based therapies, in addition to investigating the long-term effects of loading paradigms on disc degeneration and repair.

Privileged Antigen Presentation in Splenic B Cell Follicles Maximizes T Cell Responses in Prime-Boost Vaccination

Effector T cells (TEFF) are a barrier to booster vaccination because they can rapidly kill Ag-bearing APCs before memory T cells are engaged. We report in this study that i.v. delivery of rhabdoviral vectors leads to direct infection of follicular B cells in the spleen, where the earliest evidence of secondary T cell responses was observed. This allows booster immunizations to rapidly expand CD8(+) central memory T cells (TCM) during the acute phase of the primary response that is dominated by TEFF Interestingly, although the ablation of B cells before boosting with rhabdoviral vectors diminishes the expansion of memory T cells, B cells do not present Ags directly. Instead, depletion of CD11c(+) dendritic cells abrogates secondary T cell expansion, suggesting that virus-infected follicular B cells may function as an Ag source for local DCs to subsequently capture and present the Ag. Because TCM are located within B cell follicles in the spleen whereas TEFF cannot traffic through follicular regions, Ag production and presentation by follicular APCs represent a unique mechanism to secure engagement of TCM during an ongoing effector response. Our data offer insights into novel strategies for rapid expansion of CD8(+) T cells using prime-boost vaccines by targeting privileged sites for Ag presentation.

Naproxen affects osteogenesis of human mesenchymal stem cells via regulation of Indian hedgehog signaling molecules

INTRODUCTION

We previously showed that type X collagen, a marker of late stage chondrocyte hypertrophy (associated with endochondral ossification), is constitutively expressed by mesenchymal stem cells (MSCs) from osteoarthritis patients and this may be related to Naproxen (Npx), a nonsteroidal anti-inflammatory drug used for therapy. Hedgehog (HH) signaling plays an important role during the development of bone. We tested the hypothesis that Npx affected osteogenic differentiation of human MSCs through the expression of Indian hedgehog (IHH), Patched-1 (PTC1) and GLI family members GLI1, GLI2, GLI3 in vitro.

METHODS

MSCs were cultured in osteogenic differentiation medium without (control) or with 0.5 μM Npx. The expression of collagen type X, alpha 1 (COL10A1), alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OC), collagen type I, alpha 1 (COL1A1) was analyzed with real-time reverse transcription (RT) PCR, and the ALP activity was measured. The osteogenesis of MSCs was monitored by mineral staining and quantification with alizarin red S. To examine whether Npx affects osteogenic differentiation through HH signaling, the effect of Npx on the expression of IHH, GLI1, GLI2, GLI3 and PTC1 was analyzed with real-time RT PCR. The effect of cyclopamine (Cpn), a HH signaling inhibitor, on the expression of COL10A1, ALP, OC and COL1A1 was also determined.

RESULTS

When MSCs were cultured in osteogenic differentiation medium, Npx supplementation led to a significant decrease in ALP gene expression as well as its activity, and had a tendency to decrease mineral deposition. It also decreased the expression of COL1A1 significantly. In contrast, the gene expression of COL10A1 and OPN were upregulated significantly by Npx. No significant effect was found on OC expression. The expression of IHH, PTC1, GLI1, and GLI2 was increased by Npx, while no significant difference was observed on GLI3 expression. Cpn reversed the effect of Npx on the expression of COL10A1, ALP, OPN and COL1A1.

CONCLUSIONS

These results indicate that Npx can affect gene expression during osteogenic differentiation of MSCs, and downregulate mineral deposition in the extracellular matrix through IHH signaling. Therefore, Npx could affect MSC-mediated repair of subchondral bone in OA patients.

A switch I mutant of Cdc42 exhibits less conformational freedom

Cdc42 is a Ras-related small G-protein and functions as a molecular switch in signal transduction pathways linked with cell growth and differentiation. It is controlled by cycling between GTP-bound (active) and GDP-bound (inactive) forms. Nucleotide binding and hydrolysis are modulated by interactions with effectors and/or regulatory proteins. These interactions are centralized in two relatively flexible "Switch" regions as characterized by internal dynamics on multiple time scales [Loh, A. P., et al. (2001) Biochemistry 40, 4590-4600], and this flexibility may be essential for protein interactions. In the Switch I region, Thr(35) seems to be critical for function, as it is completely invariant in Ras-related proteins. To investigate the importance of conformational flexibility in Switch I of Cdc42, we mutated threonine to alanine, determined the solution structure, and characterized the backbone dynamics of the single-point mutant protein, Cdc42(T35A). Backbone dynamics data suggest that the mutation changes the time scale of the internal motions of several residues, with several resonances not being discernible in wild-type Cdc42 [Adams, P. D., and Oswald, R. E. (2007) Biomol. NMR Assignments 1, 225-227]. The mutation does not appear to affect the thermal stability of Cdc42, and chymotrypsin digestion data further suggest that changes in the conformational flexibility of Switch I slow proteolytic cleavage relative to that of the wild type. In vitro binding assays show less binding of Cdc42(T35A), relative to that of wild type, to a GTPase binding protein that inhibits GTP hydrolysis in Cdc42. These results suggest that the mutation of T(35) leads to the loss of conformational freedom in Switch I that could affect effector-regulatory protein interactions.

Defensive medicine in general practice: recent trends and the impact of the Civil Liability Act 2002 (NSW)

This article presents the results of a survey conducted among New South Wales medical practitioners to assess the extent to which the enactment of the Civil Liability Act 2002 (NSW) has reduced the practice of defensive medicine. The new legislation was intended in part to reduce the practice of defensive medicine, both "assurance-type" measures, such as performing additional tests to assure patients they have received all possible care, and "avoidance-type" measures, such as avoiding the treatment of patients who may be at a higher risk for adverse outcomes and therefore at higher risk for filing lawsuits. However, the results of the survey reveal that many medical practitioners in New South Wales remain unaware of the legal reforms and the consequent reduction in their legal liability and continue to practise defensive medicine. This article argues therefore that while the ultimate aim of reducing litigation has been achieved in New South Wales through the introduction of the Civil Liability Act, the underlying and arguably more important aim of providing medical practitioners with a more secure environment in which to practise their profession effectively has not been achieved. The apparent failure to disseminate the legal changes to the medical profession illustrates the limitations of law reform to effectively engender social change without the active use of educative and other implementation initiatives.

Prevalence of irritable bowel syndrome in young adult Malaysians: a survey among medical students

BACKGROUND AND AIMS

Irritable bowel syndrome (IBS) is a common functional bowel disease in the West. Information on the prevalence of IBS in the Asian population is relatively scanty. The aims of the present study were to determine the prevalence of IBS and to assess the symptom subgroups based on the predominant bowel habit in a young adult population of Asian origin.

METHODS

Basic demographic data and symptoms of IBS using the Rome I criteria were sought using a questionnaire administered to all apparently healthy students in a medical school. Other questions asked related to alcohol intake, smoking, chili consumption, dietary fiber intake, and to psychological and psychosomatic symptoms of anxiety, depression, insomnia, headache, and backache. The health-care seeking behavior of the subjects was also analyzed.

RESULTS

Of the 610 questionnaires administered, 533 complete responses were received (response rate of 87.4%). The responders comprised 229 men (43.0%) and 304 (57.0%) women with a mean age of 22 +/- 1.8 years. The ethnic distribution was Malays 278 (52.2%), Chinese 179 (33.6%), Indians 46 (8.6%), and others 30 (5.6%). Eighty-four (15.8%) reported symptoms consistent with the diagnosis of IBS, predominantly women. Sixty-five (77.4%) and six (7.1%) were of the constipation-predominant and diarrhea-predominant IBS subgroups, respectively. Thirteen (15.5%) subjects fell into the non-specific IBS subgroup. The self-reported psychological and psychosomatic symptoms of anxiety (P = 0.02), depression (P = 0.002), insomnia (P = 0.006), headache (P = 0.04), and backache (P = 0.006) were encountered more frequently in the subjects with IBS. Only 13.1% of the IBS group had consulted their health-care practitioner, and 20.2% reported self-medication.

CONCLUSIONS

Symptoms supportive of the diagnosis of IBS were common among young Malaysians, with a prevalence rate of 15.8%. There were significantly more women with IBS than men. Within the IBS population, the majority (77.4%) was of the constipation-predominant IBS subgroup. A significantly higher prevalence of psychological and psychosomatic symptoms was found in individuals with IBS. Only a minority sought medical advice for their symptoms.

Prevalence of irritable bowel syndrome in young adult Malaysians: a survey among medical students

BACKGROUND AND AIMS

Irritable bowel syndrome (IBS) is a common functional bowel disease in the West. Information on the prevalence of IBS in the Asian population is relatively scanty. The aims of the present study were to determine the prevalence of IBS and to assess the symptom subgroups based on the predominant bowel habit in a young adult population of Asian origin.

METHODS

Basic demographic data and symptoms of IBS using the Rome I criteria were sought using a questionnaire administered to all apparently healthy students in a medical school. Other questions asked related to alcohol intake, smoking, chili consumption, dietary fiber intake, and to psychological and psychosomatic symptoms of anxiety, depression, insomnia, headache, and backache. The health-care seeking behavior of the subjects was also analyzed.

RESULTS

Of the 610 questionnaires administered, 533 complete responses were received (response rate of 87.4%). The responders comprised 229 men (43.0%) and 304 (57.0%) women with a mean age of 22 +/- 1.8 years. The ethnic distribution was Malays 278 (52.2%), Chinese 179 (33.6%), Indians 46 (8.6%), and others 30 (5.6%). Eighty-four (15.8%) reported symptoms consistent with the diagnosis of IBS, predominantly women. Sixty-five (77.4%) and six (7.1%) were of the constipation-predominant and diarrhea-predominant IBS subgroups, respectively. Thirteen (15.5%) subjects fell into the non-specific IBS subgroup. The self-reported psychological and psychosomatic symptoms of anxiety (P = 0.02), depression (P = 0.002), insomnia (P = 0.006), headache (P = 0.04), and backache (P = 0.006) were encountered more frequently in the subjects with IBS. Only 13.1% of the IBS group had consulted their health-care practitioner, and 20.2% reported self-medication.

CONCLUSIONS

Symptoms supportive of the diagnosis of IBS were common among young Malaysians, with a prevalence rate of 15.8%. There were significantly more women with IBS than men. Within the IBS population, the majority (77.4%) was of the constipation-predominant IBS subgroup. A significantly higher prevalence of psychological and psychosomatic symptoms was found in individuals with IBS. Only a minority sought medical advice for their symptoms.

Variceal bleeding and portal hypertension: has there been any progress in the last 12 months?

A review of the literature on the management of esophagogastric varices published in the last 12 months shows that the data are still quite conflicting. In the primary and secondary prophylaxis of variceal bleeding, beta-blockers are still the mainstay of pharmacotherapy. Measurement of the hepatic portal venous pressure gradient is considered to be a reliable parameter for successful reduction of portal pressure using medical therapy. However, intolerance of propranolol requiring discontinuation of therapy has been observed in approximately 30 % of patients. Patients' compliance with medication may represent another drawback of medical therapy. The role of endoscopic band ligation in secondary prophylaxis is now indisputable, especially in comparison with sclerotherapy. In the primary prevention of variceal bleeding, band ligation is beginning to have a competitive edge over pharmacological therapy. Acute variceal bleeding is no longer a frequent morbid emergency. Most cases of bleeding can now be managed successfully with band ligation and N-butyl-2-cyanoacrylate obliteration. N-butyl-2-cyanoacrylate has come into increasingly widespread use in the treatment of bleeding gastric fundal varices in which surgery or transjugular intrahepatic portosystemic shunting were previously regarded as the preferred therapies.

The morphology of the mandibular antegonial notches and facial symmetry

Thirty randomly selected pre-treatment postero-anterior cranial radiographs of adolescent patients attending the orthodontic department, School of Dental Medicine, State University of New York at Buffalo comprised the sample in this study. The aims of this study were (1) to compare the depths of the right, and the left, mandibular antegonial notches, and (2) to determine whether the morphology of the antegonial notches bears a statistical relationship to some other transverse metrical characters of the face. The frontal cranial radiographs of thirty patients were digitized to determine the linear, and surface area, measurements of the right, and the left, antegonial notches as well as some transverse dimensions of the faces. An analysis of variance showed that no statistically significant difference existed between the measurements made by the two examiners, who digitized the radiographs. The data were analyzed by means of the Student's t-test. The results showed that there were statistically significant differences (P<0.05) between the measurements of the right, and the left, mandibular antegonial notches. The data also showed that there were highly statistically significant differences between the corresponding bilateral facial dimensions (P<0.001). The results of this study suggest that facial symmetry, as measured on a frontal skull radiograph, is associated with the respective depths of the right, and the left, mandibular antegonial notches.

Subsite study of human pepsin in disease

The synthetic peptides AC-Glu-Phe-Phe (NO2)-Arg-amide (peptide VP) and AC-Ile-Glu-Phe-Phe (NO2)-Arg-amide (peptide VIP) are more readily hydrolyzed by human pepsin in gastric juice of patients of gastritis than those of duodenal ulcer and normal subjects. The kinetic parameters suggest that S3 subsite of the enzyme plays a role in the elevation of enzyme activity in gastric disease.

Liver transplantation following preoperative closure of intrapulmonary shunts

Intrapulmonary shunts producing basal resting hypoxemia and necessitating the continual use of supplemental oxygen by two cirrhotic men were closed prior to liver transplantation with octreotide acetate, a somatostatin analogue. The closure of these shunts was monitored by serial blood gas determinations and shunt estimations using two different techniques. Partial closure of the shunts with preoperative octreotide acetate administration allowed liver transplantation to proceed with successful engraftment and eventual permanent closure of the shunts. Currently, both patients are alive and well with normal liver function and blood gases and, most important, have no requirement for supplemental oxygen.

Lactobionic acid as an iron chelator: a rationale for its effectiveness as an organ preservant

Lactobionic acid, a major constituent of a solution used to preserve organs prior to transplantation, can chelate ferric iron. This is evident by its ability to solubilize iron as well as changes that occur in the UV-VIS spectra of iron in its presence. Relative to iron (III) chelated to EDTA, the lactobionic acid-iron (III) complex is less able to participate in the Fenton reaction as measured by formaldehyde generation from DMSO and bleaching of p-N,N-dimethylnitrosoaniline. Similar effects are seen with citrate and ATP, two substances which also appear to be able to ameliorate ischemia/reperfusion injury. These findings present a rationale for the effectiveness of lactobionic acid as an organ preservant.