Ocular manifestations of HIV infection at Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa

BACKGROUND

The pattern of HIV-associated eye disease has changed with ongoing advancements in highly active antiretroviral therapy (HAART). HIV-infected individuals now live longer, enabling us to observe the long-term effects of HIV and HAART on the eye. There are few recent studies on HIV-related ocular disease in sub-Saharan Africa.

OBJECTIVES

To describe the ocular manifestations of HIV in patients attending the Nthabiseng HIV clinic at Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa.

METHODS

A cross-sectional study was conducted in 2021 and 2022 using convenience sampling of patients at the HIV clinic. The participants' clinical history was taken, their files were reviewed, and they underwent ocular examination. Correlation between eyes was managed by taking disease in one eye as the presence of disease in the participant. Descriptive statistics were used to summarise participant characteristics. Univariate and multivariate logistic regression models were used to assess the odds ratio (OR) of developing HIV-associated ocular diseases, and a p-value of <0.05 was used to define statistical significance.

RESULTS

There were 182 participants (139 females and 43 males), with a mean (standard deviation) age of 48.9 (10.6) years. The most common anterior segment diagnoses were conjunctival microangiopathy (34.6%), pinguecula (31.3%) and cataracts (30.2%), while the most common posterior segment finding was peripheral retinal scarring with features in keeping of previous cytomegalovirus retinitis (24.2%). Notably, only 1.1% of patients had HIV retinopathy. A CD4 count <200 cells/μL showed an increased OR for cataracts (OR 4.24; p=0.003) and any anterior segment diagnoses (OR 10.05; p=0.029), while a CD4 count ≥200 cells/μL showed an increased risk of conjunctival microangiopathy (OR 2.14; p=0.017).

CONCLUSION

With the advent of HAART, ocular manifestations of HIV are changing and the incidence of severe ocular opportunistic infections and HIV retinopathy has decreased precipitously. Although this study has shown that patients with a CD4 count <200 cells/μL are at increased risk of developing anterior ocular manifestations of HIV, including cataracts, these diseases are relatively innocuous or easily treatable. Routine ocular screening of HIV patients seems to be substantially less important now than it was in the pre-HAART era.

Stress perceived by drivers in public healthcare facilities in Negeri Sembilan during the first year of the COVID-19 pandemic

INTRODUCTION

Healthcare drivers, including ambulance drivers, were less concerned about health and safety during the COVID-19 pandemic, with not only the risk of COVID-19 infection but also a higher risk of prolonged states of alertness, stress, burnout, fatigue and road traffic accident. This study aimed to determine the prevalence of stress and its associated factors among healthcare drivers, especially during the COVID-19 pandemic.

MATERIALS AND METHODS

This study employs a crosssectional study design and utilises self-reported data obtained from locally validated personal stress inventory questionnaires. The data collection period spanned from August 1 to 31, 2020. The study sample consisted of 163 healthcare drivers affiliated with the Negeri Sembilan State Health Department. The Chi-square test and Fisher's exact test were the first used to determine the association between variables prior to conducting multiple logistic regression to predict the relationship between dependent and independent variables.

RESULTS

In COVID-19's first year, 7.4% (n = 12) of healthcare drivers reported perceived stress with ambulance drivers reporting more stress (10.6%; n = 5) than non-ambulance drivers (6.0%; n = 7). Simple statistical analysis identified perceived stress significantly associated with household income, smoking status and performing on-call. Further analysis by multiple logistic regression found that perceived stress was significantly related to smoking (aOR 19.9, 95% CI: 1.86-213.90), and performing on-call (aOR 8.69, 95% CI 1.21-62.28). Nevertheless, no association was found between perceived stress and age, ethnicity, marital status, education, household income, co-morbidities, driving assignment, employment duration, needing a part-time job or motor vehicle accident history.

CONCLUSION

The study found that the perceived stress amongst Malaysian healthcare drivers during the COVID-19 pandemic was relatively low. This could be due to fewer lifethreatening tasks, emergencies, assigned tasks and increase income due to overtime during the COVD-19 pandemic. The OSH team's efforts to provide consistent safety and health training, including stress management, may have contributed to the healthcare driver's ability to effectively manage the stressful circumstances encountered during the pandemic. In order to enhance salary competitiveness, employers should provide financial management education alongside subsidised housing and childcare provisions. Healthcare drivers who smoke should be taught different stress reduction techniques so that they can handle their stress in a healthy way.

The Engineer as Economist: Sewers and the Making of the Water Consumer in Colonial Cairo, 1890

Modern sewage systems were once a cutting-edge innovation that transformed how people consumed water. This article examines a debate among a group of British engineers involved in a sewage system scheme in late nineteenth-century Cairo, when Egypt was under British colonial rule. Assessing the project's economic feasibility, the engineers came to different conclusions regarding the future users of the system and, by extension, future consumers of water. Reconstructing the debate sets up a dialogue between engineering and economics to show that engineers could be economists too. This debate represents a type of economic analysis that public works engineers pioneered in the mid-nineteenth century. The engineers reached novel conclusions by centering consumers as the foundation for calculating economic realities.

Epidemiology and risk factors of colorectal cancer in Syria: a single-center retrospective study

OBJECTIVE

Colorectal cancer represents the third most common malignancy and the second leading cause of cancer deaths worldwide. Many factors contribute to the risk of developing colorectal carcinoma including diet, lifestyle, age, and genetic abnormalities.  Recent findings have shown a considerable increase in the incidence rate of CRC in developing countries. However, there is little information regarding its incidence in the Middle East countries, including Syria. With our manuscript we aimed at presenting the first large epidemiological study regarding colorectal carcinoma incidence in Syria.

PATIENTS AND METHODS

We conducted a retrospective study on colorectal carcinoma cases at our institution from 2014 to 2018. The data include the cases that were diagnosed and recorded based on multiple parameters including gender, age, year of diagnosis, city of origin, and profession.

RESULTS

The number of colorectal cancer cases was 1,117 out of 13,589 cases of all malignant tumors recorded from 2014 to 2018, with an annual average incidence of 8.2%. There was a statistically significant difference in CRC cases according to age and gender. We also found a statistically significant difference according to physical activity and occupation.

CONCLUSIONS

These results demonstrate that risk factors related to colorectal cancer incidence in Syria mainly include male sex, age over 50 years old, and occupation with no physical activity.

OP0003 DOES IMMUNOSUPPRESSIVE THERAPY IMPROVE GASTROINTESTINAL SYMPTOMS IN PATIENTS WITH SYSTEMIC SCLEROSIS?

Background

The gastrointestinal (GI) tract is frequently affected in systemic sclerosis (SSc), leading to considerable morbidity and even mortality. While important progress has been made in the last years regarding treatment of SSc, there is no disease-modifying treatment available for SSc-related GI involvement.

Objectives

We aimed to identify, in an observational cohort study of real-life patients with SSc, an association between immunosuppressive therapy and the severity of GI symptoms, measured by the University of California at Los Angeles / Scleroderma Clinical Trial Consortium Gastro-Intestinal Tract instrument 2.0 (UCLA GIT 2.0).

Methods

We selected patients from our EUSTAR centre who met the 2013 ACR/EULAR classification criteria for SSc and had at least two visits with completed UCLA GIT 2.0 questionnaires, with an interval of 12±3 months between visits. We defined the first visit with a completed UCLA GIT 2.0 questionnaire as baseline visit. Immunosuppressive therapy was defined as exposure for at least 6 months between the two visits to at least one of the following drugs, regardless of indication: mycophenolate mofetil (MMF), cyclophosphamide, methotrexate, azathioprine, leflunomide, glucocorticoids (>10mg/d prednisone-equivalent), rituximab, tocilizumab, and abatacept. The study outcome was the UCLA GIT 2.0 score at the follow-up visit. We performed multivariable linear regression with this outcome as dependent variable and immunosuppressive therapy during follow-up, immunosuppressive therapy before baseline, baseline UCLA GIT 2.0 score and several baseline parameters selected by clinical judgment as potentially influencing GI symptoms, as independent variables. Multiple imputation was implemented to handle missing values.

Results

We included 209 patients. Baseline characteristics were: 82.3% female, median (IQR) age 59.0 (48.6, 68.2) years, median disease duration 6.0 (2.7, 12.5) years, 40 (19.1%) diffuse cutaneous SSc, median baseline UCLA GIT 2.0 score 0.19 (0.06, 0.43). Of these, 71 patients were exposed to immunosuppressive therapy during the observation period: 27/71 methotrexate, 1/71 cyclophosphamide, 17/71 MMF, 3/71 leflunomide, 3/71 azathioprine, 6/71 glucocorticoids >10mg/d, 16/34 rituximab, 18/34 tocilizumab. Patients on immunosuppressive therapy during the observation period had, compared to patients without such treatment, overall more severe SSc, higher prevalence of treatment with proton pump inhibitors, similar UCLA GIT 2.0 scores at baseline and at follow up and tendentially less severe GI symptoms at baseline and follow-up by medical history. In multivariable linear regression, immunosuppressive therapy, lower body mass index, longer disease duration and lower baseline UCLA GIT 2.0 score were significantly associated with lower (better) UCLA GIT 2.0 scores at follow-up (Table 1).

Table 1.Predictors of UCLA GIT 2.0 score at follow-upEstimates95% CIpAge0.002-0.001 – 0.0060.136Sex [male]-0.056-0.172 – 0.0610.347Disease duration-0.005-0.009 – -0.0000.030Body mass index0.0140.002 – 0.0250.017UCLA GIT 2.0 total score baseline0.6900.571 – 0.809<0.001Immunosuppressive therapy during observation period-0.119-0.228 – -0.0100.032Immunosuppressive therapy before baseline0.080-0.032 – 0.1920.160Modified Rodnan Skin Score-0.001-0.008 – 0.0070.860Forced vital capacity-0.001-0.004 – 0.0010.302Erythrocyte sedimentation rate0.003-0.001 – 0.0060.116Proton pump inhibitors-0.034-0.120 – 0.0520.435(Intercept)-0.120-0.531 – 0.2910.566

Baseline factors associated with the total UCLA GIT 2.0 score at the end of the observation period. Multiple linear regression model with imputation for missing variables. N=209 patients

Conclusion

Immunosuppressive treatment was associated with lower UCLA GIT 2.0 scores, which suggests potential effects of immunosuppressants on GI manifestations in patients with SSc. These results need verification in additional studies and randomised controlled clinical trials.

References

[1]Khanna D et al. Arthritis Rheum, 2009; 61: 1257-63.

Disclosure of Interests

Lea Stamm: None declared, Alexandru Garaiman: None declared, Norina Zampatti: None declared, Mike O. Becker Speakers bureau: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Consultant of: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Grant/research support from: Mepha, MSD, Novartis, GSK, Bayer and Vifor, Cosimo Bruni Speakers bureau: Actelion, Eli-Lilly, Boehringer-Ingelheim, Grant/research support from: Abbvie, EUSTAR, Gruppo Italiano Lotta alla Sclerodermia (GILS), SCTC, Rucsandra Dobrota Consultant of: Boehringer-Ingelheim, Grant/research support from: Iten-Kohaut Foundation, Muriel Elhai: None declared, Sherif Ismail Grant/research support from: EULAR scientific training grant for young fellows 2021, Suzana Jordan: None declared, Aurora Tatu: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Carina Mihai Speakers bureau: Boehringer-Ingelheim, Mepha, MED Talks Switzerland, Consultant of: Boehringer-Ingelheim, Janssen, Grant/research support from: Boehringer-Ingelheim, Janssen, Roche.

Stabilization of the RAS:PDE6D Complex Is a Novel Strategy to Inhibit RAS Signaling

RAS is a major anticancer drug target which requires membrane localization to activate downstream signal transduction. The direct inhibition of RAS has proven to be challenging. Here, we present a novel strategy for targeting RAS by stabilizing its interaction with the prenyl-binding protein PDE6D and disrupting its localization. Using rationally designed RAS point mutations, we were able to stabilize the RAS:PDE6D complex by increasing the affinity of RAS for PDE6D, which resulted in the redirection of RAS to the cytoplasm and the primary cilium and inhibition of oncogenic RAS/ERK signaling. We developed an SPR fragment screening and identified fragments that bind at the KRAS:PDE6D interface, as shown through cocrystal structures. Finally, we show that the stoichiometric ratios of KRAS:PDE6D vary in different cell lines, suggesting that the impact of this strategy might be cell-type-dependent. This study forms the foundation from which a potential anticancer small-molecule RAS:PDE6D complex stabilizer could be developed.

Salmonella-induced pulmonary and pericardial abscesses in a patient presenting with subacute cough

The non-typhoid Salmonella (NTS) species are commonly associated with gastroenteritis and other forms of intestinal disease. Thoraco-pulmonary infections are less commonly reported. We describe the case of a 66-year-old Qatari lady who presented with subacute cough. Chest imaging revealed multiple pulmonary and a pericardial cavitary lesion with air fluid levels. Bronchoalveolar lavage culture grew Salmonella species group D. The patient was treated with 4 weeks of appropriate antibiotics. Clinical and radiological improvement were documented on subsequent follow up. To our knowledge, this is the first reported case of pulmonary and pericardial salmonella abscesses in the state of Qatar.

PINK1 drives production of mtDNA-containing extracellular vesicles to promote invasiveness

The cystine-glutamate antiporter, xCT, supports a glutathione synthesis program enabling cancer cells to cope with metabolically stressful microenvironments. Up-regulated xCT, in combination with glutaminolysis, leads to increased extracellular glutamate, which promotes invasive behavior by activating metabotropic glutamate receptor 3 (mGluR3). Here we show that activation of mGluR3 in breast cancer cells activates Rab27-dependent release of extracellular vesicles (EVs), which can transfer invasive characteristics to "recipient" tumor cells. These EVs contain mitochondrial DNA (mtDNA), which is packaged via a PINK1-dependent mechanism. We highlight mtDNA as a key EV cargo necessary and sufficient for intercellular transfer of invasive behavior by activating Toll-like receptor 9 in recipient cells, and this involves increased endosomal trafficking of pro-invasive receptors. We propose that an EV-mediated mechanism, through which altered cellular metabolism in one cell influences endosomal trafficking in other cells, is key to generation and dissemination of pro-invasive microenvironments during mammary carcinoma progression.

SARS-CoV-2 associated pathogenesis, immune dysfunction and involvement of host factors: a comprehensive review

Infectious diseases, especially viral infections, have emerged as a major concern for public health in recent years. Recently emerged COVID-19, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has been declared a pandemic by World Health Organization since March 2020. It was first identified in Wuhan, China, in December 2019 and has since claimed more than a million lives. Complicated symptoms are associated with rising incidence and fatality rates, while many of the vaccine candidates are in the final stages of clinical trials. This review encompasses a summary of existing literature on COVID-19, including the basics of the disease such as the causative agent's genome characterization, modes of transmission of the virus, pathogenesis, and clinical presentations like associated immune responses, neurological manifestations, the variety of host genetic factors influencing the disease and the vulnerability of different groups being affected by COVID-19.

CYRI-A limits invasive migration through macropinosome formation and integrin uptake regulation

The Scar/WAVE complex drives actin nucleation during cell migration. Interestingly, the same complex is important in forming membrane ruffles during macropinocytosis, a process mediating nutrient uptake and membrane receptor trafficking. Mammalian CYRI-B is a recently described negative regulator of the Scar/WAVE complex by RAC1 sequestration, but its other paralogue, CYRI-A, has not been characterized. Here, we implicate CYRI-A as a key regulator of macropinosome formation and integrin internalization. We find that CYRI-A is transiently recruited to nascent macropinosomes, dependent on PI3K and RAC1 activity. CYRI-A recruitment precedes RAB5A recruitment but follows sharply after RAC1 and actin signaling, consistent with it being a local inhibitor of actin polymerization. Depletion of both CYRI-A and -B results in enhanced surface expression of the α5β1 integrin via reduced internalization. CYRI depletion enhanced migration, invasion, and anchorage-independent growth in 3D. Thus, CYRI-A is a dynamic regulator of macropinocytosis, functioning together with CYRI-B to regulate integrin trafficking.

The Structural and Biochemical Characterization of UNC119B Cargo Binding and Release Mechanisms

Two paralogs of the guanine dissociation inhibitor-like solubilizing factors UNC119, UNC119A and UNC119B, are present in the human genome. UNC119 binds to N-myristoylated proteins and masks the hydrophobic lipid from the hydrophilic cytosol, facilitating trafficking between different membranes. Two classes of UNC119 cargo proteins have been classified: low affinity cargoes, released by the Arf-like proteins ARL2 and ARL3, and high affinity cargoes, which are specifically released by ARL3 and trafficked to either the primary cilium or the immunological synapse. The UNC119 homologues have reported differences in functionality, but the structural and biochemical bases for these differences are unknown. Using myristoylated peptide binding and release assays, we show that peptides sharing the previously identified UNC119A high affinity motif show significant variations of binding affinities to UNC119B of up to 427-fold. Furthermore, we solve the first two crystal structures of UNC119B, one in complex with the high affinity cargo peptide of LCK and a second one in complex with the release factor ARL3. Using these novel structures, we identify a stretch of negatively charged amino acids unique to UNC119B that may undergo a conformational change following binding of a release factor which we propose as an additional release mechanism specific to UNC119B.

123 Use of The Induction Mobile Application in A Busy General Surgery Department

Introduction

Contacting other hospital professionals, or accessing local guidelines is a common task for surgeons, which is usually facilitated by inefficient switchboard and intranet systems. Induction is a mobile application which includes crowd-sourced hospital directories and local guidelines, which could theoretically expedite these tasks. To assess this, we undertook a QIP within the General Surgery department using a bespoke Induction group.

Method

A private Induction group was created with the features mentioned above. We audited Induction against local trust processes (Switchboard and Intranet Trust Guidelines). We estimated cost saving using the 2019 junior doctor pay-scales. We also surveyed our department to evaluate their experiences using the application with a Likert scale.

Results

The timesaving from using Induction compared to current methods was on average 9.93 hours/week accumulated by 16 staff members, giving an estimated cost saving of £10,636.54/year. In a qualitative analysis, respondents rated Induction 4.8/5 for speed and 3.4/5 for completeness of directory, compared to 1.5/5 and 4.5/5 respectively for switchboard. Regarding accessing clinical guidelines, respondents rated the app as ‘easier’ and ‘quicker’ than the intranet.

Conclusions

We have demonstrated significant time and cost-savings using Induction compared to standard practices. Our QIP provides a replicable model to increase efficiency in surgery departments.

An ARF GTPase module promoting invasion and metastasis through regulating phosphoinositide metabolism

The signalling pathways underpinning cell growth and invasion use overlapping components, yet how mutually exclusive cellular responses occur is unclear. Here, we report development of 3-Dimensional culture analyses to separately quantify growth and invasion. We identify that alternate variants of IQSEC1, an ARF GTPase Exchange Factor, act as switches to promote invasion over growth by controlling phosphoinositide metabolism. All IQSEC1 variants activate ARF5- and ARF6-dependent PIP5-kinase to promote PI(3,4,5)P3-AKT signalling and growth. In contrast, select pro-invasive IQSEC1 variants promote PI(3,4,5)P3 production to form invasion-driving protrusions. Inhibition of IQSEC1 attenuates invasion in vitro and metastasis in vivo. Induction of pro-invasive IQSEC1 variants and elevated IQSEC1 expression occurs in a number of tumour types and is associated with higher-grade metastatic cancer, activation of PI(3,4,5)P3 signalling, and predicts long-term poor outcome across multiple cancers. IQSEC1-regulated phosphoinositide metabolism therefore is a switch to induce invasion over growth in response to the same external signal. Targeting IQSEC1 as the central regulator of this switch may represent a therapeutic vulnerability to stop metastasis.

Structural Basis of CYRI-B Direct Competition with Scar/WAVE Complex for Rac1

Rac1 is a major regulator of actin dynamics, with GTP-bound Rac1 promoting actin assembly via the Scar/WAVE complex. CYRI competes with Scar/WAVE for interaction with Rac1 in a feedback loop regulating actin dynamics. Here, we reveal the nature of the CYRI-Rac1 interaction, through crystal structures of CYRI-B lacking the N-terminal helix (CYRI-BΔN) and the CYRI-BΔN:Rac1Q61L complex, providing the molecular basis for CYRI-B regulation of the Scar/WAVE complex. We reveal CYRI-B as having two subdomains - an N-terminal Rac1 binding subdomain with a unique Rac1-effector interface and a C-terminal Ratchet subdomain that undergoes conformational changes induced by Rac1 binding. Finally, we show that the CYRI protein family, CYRI-A and CYRI-B can produce an autoinhibited hetero- or homodimers, adding an additional layer of regulation to Rac1 signaling.

ARL3 activation requires the co-GEF BART and effector-mediated turnover

The ADP-ribosylation factor-like 3 (ARL3) is a ciliopathy G-protein which regulates the ciliary trafficking of several lipid-modified proteins. ARL3 is activated by its guanine exchange factor (GEF) ARL13B via an unresolved mechanism. BART is described as an ARL3 effector which has also been implicated in ciliopathies, although the role of its ARL3 interaction is unknown. Here, we show that, at physiological GTP:GDP levels, human ARL3GDP is weakly activated by ARL13B. However, BART interacts with nucleotide-free ARL3 and, in concert with ARL13B, efficiently activates ARL3. In addition, BART binds ARL3GTP and inhibits GTP dissociation, thereby stabilising the active G-protein; the binding of ARL3 effectors then releases BART. Finally, using live cell imaging, we show that BART accesses the primary cilium and colocalises with ARL13B. We propose a model wherein BART functions as a bona fide co-GEF for ARL3 and maintains the active ARL3GTP, until it is recycled by ARL3 effectors.

Understanding the structure of a country’s health service providers for defence health engagement

There are a variety of structural and systems frameworks for describing the building blocks of country’s public health and health systems. In this paper, we propose a conceptual framework for a holistic view of a country’s health service providers in order to inform the plan for Defence Health Engagement activities with partner countries. This includes all potential government ministries involved in healthcare provision, the independent, private sector and the non-government organisation/charity sector. The framework provides a visualisation to support the analysis of a country’s health services providers. We propose that recognising and analysing the different contributions of all these national health providers is essential for understanding the wider political economy of a nation’s health systems. This can inform a plan of Defence Health Engagement for capacity building in crisis response, development and health systems strengthening.

Spatiotemporal Regulation of Signaling: Focus on T Cell Activation and the Immunological Synapse

In a signaling network, not only the functions of molecules are important but when (temporal) and where (spatial) those functions are exerted and orchestrated is what defines the signaling output. To temporally and spatially modulate signaling events, cells generate specialized functional domains with variable lifetime and size that concentrate signaling molecules, enhancing their transduction potential. The plasma membrane is a key in this regulation, as it constitutes a primary signaling hub that integrates signals within and across the membrane. Here, we examine some of the mechanisms that cells exhibit to spatiotemporally regulate signal transduction, focusing on the early events of T cell activation from triggering of T cell receptor to formation and maturation of the immunological synapse.

Bacterial delivery of the anti-tumor azurin-like protein Laz to glioblastoma cells

Salmonella typhimurium VNP-20009 (VNP) is a non-pathogenic attenuated strain, which, as a facultative anaerobe, preferentially accumulates in hypoxic regions of solid tumors. Here, VNP was utilized as a delivery vehicle of the anti-tumor protein Lipidated azurin, Laz, which is produced by the meningitis-causing bacterium Neisseria meningitides. In brain cancer cells, Laz has been demonstrated to induce apoptosis through an interaction with the tumor suppressor protein p53. In this study, the laz gene, including its signal sequence, was cloned downstream of a hypoxia inducible promoter (HIP-1), before being electroporated into VNP. Successful ectopic expression and export of the Laz protein by VNP under hypoxic conditions were confirmed by Western blot analysis of the cell-free culture medium. Effective expression of Laz by VNP was investigated in two glioblastoma cell lines: LN-229 and U-373, with the latter line carrying a mutated version of p53; as well as in the breast cancer line MCF-7. Cytotoxicity of the VNP-Laz was assessed by determining the fluorescence of the apoptotic marker caspases 3/7. Compared to the purified Laz, VNP-Laz, significantly induced apoptosis in MCF-7, LN-229 and, to a much lower extent in U-373 cells, suggesting a p53-linked mechanism. Our results might represent a new approach of targeted gene delivery and suggest a potential application in brain tumor therapy.

ARL3, a small GTPase with a functionally conserved role in primary cilia and immune synapses

The primary cilium and the immunological synapse are both specialized functional plasma membrane domains that share several similarities. Signalling output of membrane domains is regulated, spatially and temporally, by segregating and focusing lipids and proteins. ARL3, a small GTPase, plays a major role in concentrating lipid-modified proteins in both the immunological synapse and the primary cilia. Here in this review we will introduce the role of ARL3 in health and disease and its role in polarizing signalling at the primary cilia and immunological synapses.

WASP Restricts Active Rac to Maintain Cells' Front-Rear Polarization

Efficient motility requires polarized cells, with pseudopods at the front and a retracting rear. Polarization is maintained by restricting the pseudopod catalyst, active Rac, to the front. Here, we show that the actin nucleation-promoting factor Wiskott-Aldrich syndrome protein (WASP) contributes to maintenance of front-rear polarity by controlling localization and cellular levels of active Rac. Dictyostelium cells lacking WASP inappropriately activate Rac at the rear, which affects their polarity and speed. WASP's Cdc42 and Rac interacting binding ("CRIB") motif has been thought to be essential for its activation. However, we show that the CRIB motif's biological role is unexpectedly complex. WASP CRIB mutants are no longer able to restrict Rac activity to the front, and cannot generate new pseudopods when SCAR/WAVE is absent. Overall levels of Rac activity also increase when WASP is unable to bind to Rac. However, WASP without a functional CRIB domain localizes normally at clathrin pits during endocytosis, and activates Arp2/3 complex. Similarly, chemical inhibition of Rac does not affect WASP localization or activation at sites of endocytosis. Thus, the interaction between small GTPases and WASP is more complex than previously thought-Rac regulates a subset of WASP functions, but WASP reciprocally restricts active Rac through its CRIB motif.

Prevalence of Cryptosporidium spp. infection among children admitted to Hospital Tengku Ampuan Afzan

INTRODUCTION

Cryptosporidium spp. is identified as an important cause of diarrhoeal morbidity and mortality worldwide particularly in children below five years of age and immunocompromised individuals. Infections are present among cattle and humans. Until now, there is no report on its prevalence in humans in Kuantan. The aim of this study is to record the prevalence and associated risk factors of Cryptosporidium spp. infection among children admitted to Hospital Tengku Ampuan Afzan (HTAA), Kuantan.

METHODS

This is a cross-sectional study conducted among children admitted to the Paediatrics ward in HTAA between December 2017 and May 2018. Faecal samples were examined using wet smear and Modified Ziehl-Neelsen (MZN) staining techniques. Data on demography and hygiene practices was collected using a pretested questionnaire, and analysed using SPSS version 22.

RESULTS

One hundred thirty five children (95.6% were of Malay ethnicity) were included in the study. The overall prevalence of Cryptosporidium spp. infection was 25.2%. The prevalence was slightly higher in females (28.1%) than males (23.1%). The prevalence was higher than expected. This study showed that some risk factors namely children's age and trash disposal methods were significantly associated with Cryptosporidium spp. infection (p<0.05).

CONCLUSION

Higher prevalence could possibly be due to an outbreak of this infection or until now undetected.

Abstract AP18: PRO-INVASIVE TUMOUR-STROMA INTERACTIONS: ROLE OF THE SECRETED OXIDOREDUCTASE CLIC3

Cancer cells are embedded within a microenvironment populated with cancer associated fibroblasts (CAFs) with whom they establish two-way communications through paracrine factors and physical interactions. Through these interactions, CAFs play pivotal roles in cancer and have emerged as promising therapeutic target.

To unravel key contributors of CAF-tumour/stroma cell interactions, we have developed mass spectrometry (MS)-based approaches to map proteins secreted in condition medium and extracellular matrix (ECM). Through an extensive MS-proteomic comparative analysis of CAFs with their normal fibroblasts (NFs) counterpart, we have identified the chloride intracellular channel protein 3 (CLIC3), a protein previously considered an intracellular chloride channel (regulator), as one of the most upregulated proteins in CAFs and deposited in the ECM.

Secreted CLIC3 promotes invasive behaviour of endothelial cells to drive blood vessels growth and increases invasiveness of cancer cells, both in vivo and in 3D cell culture models, via activation of the tissue transglutaminase-2 (TGM2). We found that CLIC3 is a glutathione-dependent oxidoreductase that reduces TGM2 and regulates TGM2 binding to its cofactors. Finally, CLIC3 is also secreted by cancer cells, is abundant in the stromal and tumour compartments of aggressive ovarian cancers and its levels in primary tumours and omental metastases correlate with poor clinical outcome.

Our work has unraveled an unprecedented mechanism of cell invasion to be explored for targeting in ovarian cancer.

Citation Format: Juan R Hernandez-Fernaud, Elena Ruengeler, Lisa J Neilson, Shehab Ismail, Iain McNeish, Samuel Atkinson, Sergio Lilla, Alice Santi, Stella M Valenzuela, Karen Blyth, Huabing Yin, Massimiliano Mazzone, Jim C Norman and Sara Zanivan. PRO-INVASIVE TUMOUR-STROMA INTERACTIONS: ROLE OF THE SECRETED OXIDOREDUCTASE CLIC3 [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr AP18.

Intranasal inoculation of recombinant DNA vaccine ABA392 against haemorrhagic septicaemia disease

We evaluate the efficacy of recombinant DNA vaccine ABA392 against haemorrhagic septicaemia infection through intranasal administration route by targeting the mucosal immunity. The DNA vaccine was constructed and subjected to animal study using the Sprague Dawley (SD) rat. The study was divided into two major parts: (i) active and (ii) passive immunization studies, involving 30 animals for each part. Each group was then divided into five test groups: two test samples G1 and G2 with 50 and 100 µg ml^-1 purified DNA vaccine; one positive control G5 with 10⁶  CFU per ml formalin-killed PMB2; and two negative controls, G3 and G4 with normal saline and pVAX1 vector. Both studies were conducted for the determination of immunogenicity by total white blood cell count (TWBC), indirect ELISA and histopathological changes for the presence of the bronchus-associated lymphoid tissue (BALT). Our findings demonstrate that TWBC, IgA and IgG increased after each of the three vaccination regimes: groups G1, G2 and G5. Test samples G1 and G2 showed significant differences (P < 0·05) compared to the negative controls, G3 and G4, but no significant differences from the positive control G5. Groups G1, G2 and G5 showed more formation of BALT compared to the negative controls, G3 and G4. Our results show that intranasal inoculation of recombinant DNA vaccine ABA392 can provoke mucosal immunity which makes it a potential prophylactic against HS. SIGNIFICANCE AND IMPACT OF THE STUDY: New approach of combating haemorrhagic septicaemia disease among bovines by recombinant DNA vaccine is crucial to overcome the loss of edible products from the infected bovines. DNA vaccine can potentially serve as a better immunogen which would elicit both cellular and humoral immunity, and it is also stable for its molecular reproduction. This research report demonstrates an effective yet simple way of administering the DNA vaccine via the intranasal route in rats, to provoke the mucosal immunity through the development of immunoglobulins IgA, IgG and bronchus-associated lymphoid tissue which guard as the first-line defence at the host's mucosal lining.

Hypoxic cancer-associated fibroblasts increase NCBP2-AS2/HIAR to promote endothelial sprouting through enhanced VEGF signaling

Intratumoral hypoxia causes the formation of dysfunctional blood vessels, which contribute to tumor metastasis and reduce the efficacy of therapeutic treatments. Blood vessels are embedded in the tumor stroma of which cancer-associated fibroblasts (CAFs) constitute a prominent cellular component. We found that hypoxic human mammary CAFs promoted angiogenesis in CAF-endothelial cell cocultures in vitro. Mass spectrometry-based proteomic analysis of the CAF secretome unraveled that hypoxic CAFs contributed to blood vessel abnormalities by altering their secretion of various pro- and anti-angiogenic factors. Hypoxia induced pronounced remodeling of the CAF proteome, including proteins that have not been previously related to this process. Among those, the uncharacterized protein NCBP2-AS2 that we renamed HIAR (hypoxia-induced angiogenesis regulator) was the protein most increased in abundance in hypoxic CAFs. Silencing of HIAR abrogated the pro-angiogenic and pro-migratory function of hypoxic CAFs by decreasing secretion of the pro-angiogenic factor VEGFA and consequently reducing VEGF/VEGFR downstream signaling in the endothelial cells. Our study has identified a regulator of angiogenesis and provides a map of hypoxia-induced molecular alterations in mammary CAFs.

Effect And Predictive Value Of Routine Preoperative Laboratory Testing For Endoscopic Retrograde Cholangiopancreatography

BACKGROUND AND AIMS

Several studies and guidelines are questioning routine preoperative laboratory tests in surgical and endoscopic procedures. Their effect in endoscopic retrograde cholangiopancreatography is not currently known. This study was carried out to evaluate the risk of adverse effects in endoscopic retrograde cholangiopancreatography and their association with preoperative lab tests.

MATERIALS AND METHODS

A single-center, prospective observational study on all 956 patients undergoing 1196 endoscopic retrograde cholangiopancreatographies in the Endoscopy Unit of Helsinki University Central Hospital from 1 March 2012 to 28 February 2013. Routine preoperative laboratory test results (basic blood count, creatinine, potassium, sodium, international normalized ratio/thromboplastin time, and amylase), health status, medication, and demographic information of all patients were analyzed in relation to adverse effects related to endoscopic retrograde cholangiopancreatography and procedural sedation.

RESULTS

Multivariate analysis showed post-endoscopic retrograde cholangiopancreatography pancreatitis (43 cases, 3.6%) to have no association with abnormal routine preoperative laboratory tests. Respiratory depression caused by sedation (128 cases, 11%) was not associated with abnormal routine preoperative laboratory tests, and anemia was found to be a slightly protecting factor. Cardiovascular depression caused by sedation was associated with thrombocytopenia (odds ratio = 1.87, p = 0.025) and, in male patients, hyponatremia (odds ratio = 3.66, p < 0.001). Incidence of other adverse effects was too low for statistical analysis.

CONCLUSION

Routine universal preoperative lab testing was not found to be successful in predicting adverse effects in endoscopic retrograde cholangiopancreatography procedures. Laboratory testing should be done focusing on each patient's individual needs.

Encapsulation of Bacillus salmalaya 139SI using double coating biopolymer technique

Sustainable crop production for a rapidly growing human population is one of the current challenges faced by the agricultural sector. However, many of the chemical agents used in agriculture can be hazardous to humans, non-targeted organism and environment. Plant growth promoting rhizobacteria have demonstrated a role in promoting plant growth and health under various stress conditions including disease. Unfortunately, bacterial viability degrades due to temperature and other environmental factors (Bashan et al., Plant Soil 378: 1-33, 2014). Encapsulation of bacteria into core-shell biopolymers is one of the promising techniques to overcome the problem. This study deals with the encapsulation of Bacillus salmalaya 139SI using simple double coating biopolymer technique which consist of brown rice protein/alginate and 0·5% low molecular weight chitosan of pH 4 and 6. The influence of biopolymer to bacteria mass ratio and the chitosan pH on the encapsulation process, physic-chemical, morphology and bioactivity properties of encapsulated B. salmalaya 139SI have been studied systematically. Based on the analysis of physico-chemical, morphology and bioactivity properties, B. salmalaya 139S1 encapsulated using double coating encapsulation technology has promising viability pre- and postfreeze-drying with excellent encapsulation yields of 99·7 and 89·3% respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The need of a simple yet effective way of encapsulating plant growth promoting rhizobacteria is crucial to further improve their benefits to global sustainable agriculture practice. Effective encapsulation allows for protection, controlled release and function of the micro-organism, as well as providing a longer shelf life for the product. This research report offers an innovative yet simple way of encapsulating using double coating technology with environmentally friendly biopolymers that could degrade and provide nutrients when in soil. Importantly, the bioactivity of the bacteria is maintained upon encapsulation.

An Empirical Study of Service Quality and Customer Satisfaction of Malaysian Air Passenger

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The Ciliary Machinery Is Repurposed for T Cell Immune Synapse Trafficking of LCK

Upon engagement of the T cell receptor with an antigen-presenting cell, LCK initiates TCR signaling by phosphorylating its activation motifs. However, the mechanism of LCK activation specifically at the immune synapse is a major question. We show that phosphorylation of the LCK activating Y394, despite modestly increasing its catalytic rate, dramatically focuses LCK localization to the immune synapse. We describe a trafficking mechanism whereby UNC119A extracts membrane-bound LCK by sequestering the hydrophobic myristoyl group, followed by release at the target membrane under the control of the ciliary ARL3/ARL13B. The UNC119A N terminus acts as a "regulatory arm" by binding the LCK kinase domain, an interaction inhibited by LCK Y394 phosphorylation, thus together with the ARL3/ARL13B machinery ensuring immune synapse focusing of active LCK. We propose that the ciliary machinery has been repurposed by T cells to generate and maintain polarized segregation of signals such as activated LCK at the immune synapse.

ARL3 Mutations Cause Joubert Syndrome by Disrupting Ciliary Protein Composition

Joubert syndrome (JBTS) is a genetically heterogeneous autosomal-recessive neurodevelopmental ciliopathy. We investigated further the underlying genetic etiology of Joubert syndrome by studying two unrelated families in whom JBTS was not associated with pathogenic variants in known JBTS-associated genes. Combined autozygosity mapping of both families highlighted a candidate locus on chromosome 10 (chr10: 101569997-109106128, UCSC Genome Browser hg 19), and exome sequencing revealed two missense variants in ARL3 within the candidate locus. The encoded protein, ADP ribosylation factor-like GTPase 3 (ARL3), is a small GTP-binding protein that is involved in directing lipid-modified proteins into the cilium in a GTP-dependent manner. Both missense variants replace the highly conserved Arg149 residue, which we show to be necessary for the interaction with its guanine nucleotide exchange factor ARL13B, such that the mutant protein is associated with reduced INPP5E and NPHP3 localization in cilia. We propose that ARL3 provides a potential hub in the network of proteins implicated in ciliopathies, whereby perturbation of ARL3 leads to the mislocalization of multiple ciliary proteins as a result of abnormal displacement of lipidated protein cargo.

Fam49/CYRI interacts with Rac1 and locally suppresses protrusions

Actin-based protrusions are reinforced through positive feedback, but it is unclear what restricts their size, or limits positive signals when they retract or split. We identify an evolutionarily conserved regulator of actin-based protrusion: CYRI (CYFIP-related Rac interactor) also known as Fam49 (family of unknown function 49). CYRI binds activated Rac1 via a domain of unknown function (DUF1394) shared with CYFIP, defining DUF1394 as a Rac1-binding module. CYRI-depleted cells have broad lamellipodia enriched in Scar/WAVE, but reduced protrusion-retraction dynamics. Pseudopods induced by optogenetic Rac1 activation in CYRI-depleted cells are larger and longer lived. Conversely, CYRI overexpression suppresses recruitment of active Scar/WAVE to the cell edge, resulting in short-lived, unproductive protrusions. CYRI thus focuses protrusion signals and regulates pseudopod complexity by inhibiting Scar/WAVE-induced actin polymerization. It thus behaves like a 'local inhibitor' as predicted in widely accepted mathematical models, but not previously identified in cells. CYRI therefore regulates chemotaxis, cell migration and epithelial polarization by controlling the polarity and plasticity of protrusions.

Summary of the NACI Update on Herpes Zoster Vaccines

BACKGROUND

Steep increases in herpes zoster (HZ) incidence, hospitalization due to HZ and the risk of post-herpetic neuralgia as a complication of HZ occur in people over 50 years of age. Two HZ vaccines are currently authorized for use in those 50 years of age and older in Canada: a live attenuated zoster vaccine (LZV) authorized in 2008; and a recombinant subunit vaccine (RZV) authorized in October 2017.

OBJECTIVES

To review current evidence and develop guidance on whether the previously authorized LZV (Zostavax®) and/or the recently authorized RZV (Shingrix®) vaccine should be offered to Canadians 50 years of age and older: 1) at a population-level, in publicly funded immunization programs; and 2) at an individual-level, to individuals wishing to prevent HZ, or by clinicians wishing to advise individual patients about preventing HZ.

METHODS

The National Advisory Committee on Immunization (NACI) Herpes Zoster Working Group developed a predefined search strategy to identify all eligible studies, assessed their quality, and summarized and analyzed the findings. A Cost Utility Analysis of LZV and RZV was also conducted from a health care system perspective. Recommendations were proposed according to NACI's evidence-based process. The strength of these recommendations was defined, and the Grade of evidence supporting them was identified. In light of the evidence, the recommendations were then considered and approved by NACI.

RESULTS

Five recommendations were developed for public health and individual-level decision-making. 1) RZV should be offered to populations/individuals >50 years of age without contraindications (Strong NACI Recommendation, Grade A evidence). 2) RZV should be offered to populations/individuals >50 years of age without contraindications who have previously been vaccinated with LZV (Strong NACI Recommendation, Grade A evidence). Re-immunization with two doses of RZV may be considered one year after LZV (Discretionary NACI Recommendation, Grade I evidence). 3) RZV should be offered to populations/individuals >50 years of age without contraindications who have had a previous episode of HZ (Strong NACI Recommendation, Grade B evidence). Immunization with two doses of RZV may be considered one year after the HZ episode (Discretionary NACI Recommendation, Grade I evidence). 4) LZV may be considered for immunocompetent populations/individuals >50 years of age without contraindications when RZV is contraindicated, unavailable or inaccessible (Discretionary NACI Recommendation, Grade A evidence). 5) RZV (not LZV) may be considered in immunocompromised adults >50 years of age on a case-by-case basis (Discretionary NACI Recommendation, Grade I evidence).

CONCLUSION

Both vaccines have been shown to be safe and immunogenic and to reduce the incidence of HZ and post-herpetic neuralgia. Vaccine efficacy of LZV against HZ decreases with age at, and time since vaccination. The vaccine efficacy of RZV remains higher and appears to decline more slowly than vaccine efficacy of LZV across all age groups. Both vaccines are cost-effective in those 50 years of age and older compared with no vaccination, especially in those 65-79 years of age. RZV is more cost-effective than LZV.

HIV-2 Infection in Malaysia: Current situation and the use of in-house real-time reverse transcription PCR for HIV-2

HIV-2 surveillance has been carried out in Malaysia for more than 25 years ago. Tests to discriminate HIV-1 and HIV-2 are available but the options of test are limited and the need to develop a new in-house HIV-2 real-time reverse transcription PCR (RT-PCR) is crucial. A study was done on 29 samples from hospitals in Malaysia which were found to be positive screening for HIV-2 antibodies by the commercial Western Blot assay. These samples were further tested by a Western Blot assay that detects specific antibodies to HIV-2. Detection of HIV-2 genome was then performed by using a commercial kit. Fifteen samples were evaluated by using in-house real-time RT-PCR for HIV-2. Ninety-three percent (27/29) of samples have positive results for HIV-2 on HIV-2 Western Blot with only 2 samples showing indeterminate results. All samples showed negative results for HIV-2 genomes by using a PCR commercial kit and the 15 samples that were subjected to our in-house real-time RT-HIV-2 PCR were also tested negative for HIV-2 RNA. Results of HIV-2 Western Blot did not reflect the actual positivity as both HIV-1 and HIV-2 antibodies may cross-react with either viral proteins. None of the samples was confirmed positive for HIV-2 by the commercial and in-house real-time RTPCR. In-house real-time RT-HIV-2 PCR assay can be further used to confirm the presence of HIV-2 genome. Up to the year 2015, Malaysia is still free from HIV-2 infection.

A clinicopathologic study of 173 odontogenic tumours in Northern Peninsular Malaysia (2007-2014)

INTRODUCTION

The objectives of this study were to analyse, compare and contrast the demographic, clinical and pathological data of odontogenic tumours seen at a regional oral pathology centre in the Northern part of Peninsular Malaysia with other international data as an aid to clinicians in diagnosing odontogenic tumours.

MATERIALS AND METHODS

This was a descriptive, retrospective study of odontogenic tumours diagnosed from January 2007 to December 2014 at this centre. The odontogenic tumours were classified using the 2005 World Health Organization classification system.

RESULTS

Among 2,733 biopsy specimens, 173 cases were diagnosed as odontogenic tumours (6.3%), of which 171 (98.8%) are benign and 2 (1.2%) are malignant. The most frequently encountered tumour was ameloblastoma (n=96, 55.5%), followed by keratocystic odontogenic tumour (KCOT) (n=38, 22.0%) and odontomas (n=16, 9.2%). Malignant tumours accounted for 1.2% of the tumours. Most ameloblastomas and KCOTs affected the mandible preferentially. The mean age was 33.5 (± 17.8) years and 64.7% of patients were in the age group of 10 to 39. Odontogenic tumours were slightly more common in males, with a male to female ratio of 1.4:1.

CONCLUSION

The findings of this study are similar to the other studies in Asia in which the most common tumour encountered is the ameloblastoma, followed by KCOT. The most common signs and symptoms are pain and swelling, while paraesthesia and root resorption are less frequently reported. Such clinical and radiographic features should alert the clinician of a possible odontogenic tumour and though rare, malignant tumours should also be included in the differential diagnoses.

Change in Mallampati class during labor: Hypertensive versus normotensive parturients

BACKGROUND

Mallampati class has been shown to increase during labor. There are no prospective studies evaluating airway changes in hypertensive parturients during labor. The aim of our study was to observe the frequency of change in Mallampati class during labor in hypertensive compared to normotensive parturients.

METHODS

In this prospective observational cohort study, 60 parturients were enrolled and divided into two groups of 30 each: hypertensive parturients and normotensive parturients. The Mallampati class was evaluated in each parturient at two points; during early labor (cervical dilation 1-3 cm and regular contractions) taken as T1 and at 20 minutes after delivery taken as T2. The change in Mallampati class from T1 to T2 was compared between the two groups. Post-stratification chi-square test was applied and P value <.05 was considered as significant.

RESULTS

The change in Mallampati class was significantly more frequent in hypertensive group as compared to normotensive group [80% (24/30) vs 46.7% (14/30); P = .002]. Overall, an increase in Mallampati class during labor was found with statistically significant difference between the hypertensive and normotensive group [80% (24/30) vs 42.9% (12/28); P = .004]. The risk of increase in Mallampati class was 2 times higher in hypertensive women as compared to normotensive 2.44; 95% CI: 1.19 to 5.02].

CONCLUSION

Mallampati class showed 2-fold increase in hypertensive compared to normotensive parturients during labor; requiring additional caution during airway management.

Evaluation of reference values of standard semen parameters in fertile Egyptian men

The reference values of human semen, published in the WHO's latest edition in 2010, were lower than those previously reported. The objective of this study was to evaluate reference values of standard semen parameters in fertile Egyptian men. This cross-sectional study included 240 fertile men. Men were considered fertile when their wives had recent spontaneous pregnancies with time to pregnancy (TTP) ≤12 months. The mean age of fertile men was 33.8 ± 0.5 years (range 20-55 years). The 5th percentiles (95% confidence interval) of macroscopic semen parameters were 1.5 ml for volume and 7.2 for pH. The 5th percentiles of microscopic parameters were 15 million/ml for sperm concentration, 30 million per ejaculate for total sperm count, 50% for total motility, 40% for progressive motility, 62% for vitality, 4% for normal sperm forms and 0.1 million/ml for seminal leucocyte counts. In conclusion, fertile Egyptian men had higher reference values of sperm total motility, progressive motility and vitality, and lower reference values for total sperm counts as compared to those determined by the latest edition of the WHO laboratory manual in 2010. Other semen parameters were identical to those defined by the WHO 2010 manual.

Maintaining protein composition in cilia

The primary cilium is a sensory organelle that is vital in regulating several signalling pathways. Unlike most organelles cilia are open to the rest of the cell, not enclosed by membranes. The distinct protein composition is crucial to the function of cilia and many signalling proteins and receptors are specifically concentrated within distinct compartments. To maintain this composition, a mechanism is required to deliver proteins to the cilium whilst another must counter the entropic tendency of proteins to distribute throughout the cell. The combination of the two mechanisms should result in the concentration of ciliary proteins to the cilium. In this review we will look at different cellular mechanisms that play a role in maintaining the distinct composition of cilia, including regulation of ciliary access and trafficking of ciliary proteins to, from and within the cilium.

A GDI/GDF-like system for sorting and shuttling ciliary proteins

Post/co-translational modifications by the addition of lipids take place in a vast number of proteins. Rab and Rho are small G proteins which are prenylated and targeted to membranes in complex with solubilizing factors called guanosine dissociation inhibitors (GDIs). The release of Rab and Rho at the correct destination from their cognate GDI has been proposed to be mediated through GDI displacement factors. However this mechanism is yet to be established and it has been shown that loading of Rab proteins with GTP at the destination can be sufficient for their correct targeting. PDE6D shares structural homology with Rho GDI and solubilises several prenylated proteins and mediate their targeting to different destinations including cilia. In a paper published by Fansa et al, the authors propose that sorting of cargo is dependent on the differential release by bona fide GDFs, Arl2 and Arl3, and the localization of the active Arl3GTP in cilia.

Saharan dust, convective lofting, aerosol enhancement zones, and potential impacts on ice nucleation in the tropical upper troposphere

Dry aerosol size distributions and scattering coefficients were measured on 10 flights in 32 clear-air regions adjacent to tropical storm anvils over the eastern Atlantic Ocean. Aerosol properties in these regions were compared with those from background air in the upper troposphere at least 40 km from clouds. Median values for aerosol scattering coefficient and particle number concentration >0.3 μm diameter were higher at the anvil edges than in background air, showing that convective clouds loft particles from the lower troposphere to the upper troposphere. These differences are statistically significant. The aerosol enhancement zones extended ~10-15 km horizontally and ~0.25 km vertically below anvil cloud edges but were not due to hygroscopic growth since particles were measured under dry conditions. Number concentrations of particles >0.3 μm diameter were enhanced more for the cases where Saharan dust layers were identified below the clouds with airborne lidar. Median number concentrations in this size range increased from ~100 l-1 in background air to ~400 l-1 adjacent to cloud edges with dust below, with larger enhancements for stronger storm systems. Integration with satellite cloud frequency data indicates that this transfer of large particles from low to high altitudes by convection has little impact on dust concentrations within the Saharan Air Layer itself. However, it can lead to substantial enhancement in large dust particles and, therefore, heterogeneous ice nuclei in the upper troposphere over the Atlantic. This may induce a cloud/aerosol feedback effect that could impact cloud properties in the region and downwind.

Tumor matrix stiffness promotes metastatic cancer cell interaction with the endothelium

Tumor progression alters the composition and physical properties of the extracellular matrix. Particularly, increased matrix stiffness has profound effects on tumor growth and metastasis. While endothelial cells are key players in cancer progression, the influence of tumor stiffness on the endothelium and the impact on metastasis is unknown. Through quantitative mass spectrometry, we find that the matricellular protein CCN1/CYR61 is highly regulated by stiffness in endothelial cells. We show that stiffness-induced CCN1 activates β-catenin nuclear translocation and signaling and that this contributes to upregulate N-cadherin levels on the surface of the endothelium, in vitro This facilitates N-cadherin-dependent cancer cell-endothelium interaction. Using intravital imaging, we show that knockout of Ccn1 in endothelial cells inhibits melanoma cancer cell binding to the blood vessels, a critical step in cancer cell transit through the vasculature to metastasize. Targeting stiffness-induced changes in the vasculature, such as CCN1, is therefore a potential yet unappreciated mechanism to impair metastasis.

Activated electric arc furnace slag as an effective and reusable Fenton-like catalyst for the photodegradation of methylene blue and acid blue 29

In this work, an activated electric arc furnace slag (A-EAFS) was investigated as an effective Fenton catalyst for the photodegradation of methylene blue (MB) and acid blue 29 (AB29). Fourier transform infrared spectroscopy and UV-visible absorption analyses indicated that A-EAFS offers additional Fe₃O₄ because of the changes in the iron oxide phase and the favorable response to visible light. It has been found that the highest degradation efficiency can reach up to 94% for MB under optimal conditions of 1 g L^-1 of A-EAFS, 20 mM H₂O₂, and pH 3. The optimal conditions for AB29 were 0.1 g L^-1 A-EAFS, 4 mM H₂O₂, and pH 3 to reach 98% degradation efficiency. Visible light enhanced the degradation of both dyes. In addition, A-EAFS, could be easily separated magnetically, exhibited good chemical stability after seven successive photodegradation cycles.

Development of Pyridazinone Chemotypes Targeting the PDEδ Prenyl Binding Site

The K-Ras GTPase is a major target in anticancer drug discovery. However, direct interference with signaling by K-Ras has not led to clinically useful drugs yet. Correct localization and signaling by farnesylated K-Ras is regulated by the prenyl binding protein PDEδ. Interfering with binding of PDEδ to K-Ras by means of small molecules provides a novel opportunity to suppress oncogenic signaling. Here we describe the identification and structure-guided development of novel K-Ras-PDEδ inhibitor chemotypes based on pyrrolopyridazinones and pyrazolopyridazinones that bind to the farnesyl binding pocket of PDEδ with low nanomolar affinity. We delineate the structure-property relationship and in vivo pharmacokinetic (PK) and toxicokinetic (Tox) studies for pyrazolopyridazinone-based K-Ras-PDEδ inhibitors. These findings may inspire novel drug discovery efforts aimed at the development of drugs targeting oncogenic Ras.