From doping to composites: zirconia (ZrO2) modified hematite photoanodes for water splitting

Herein, a ZrO2 added α-Fe2O3 photoanode that can split water at low applied potential is reported. First, the pristine hematite α-Fe2O3 photoanode was synthesized using an aerosol-assisted chemical vapour deposition (AACVD) method followed by modification with various amounts of ZrO2 (2 to 40%) in the form of thin films on conducting glass substrate. The XRD, Raman spectroscopy and scanning electron microscopy (SEM) analyses confirmed the presence of the monoclinic phase of ZrO2 in the composites with multifaceted particles of compact morphology. The optical analysis showed an increase in the absorbance and variation in band gap of the composites ascribed to the heterogeneity of the material. The photoelectrochemical studies gave a photocurrent density of 1.23 mA cm-2 at 1.23 V vs. RHE for the pristine hematite and remarkably higher value of 3.06 mA cm-2 for the optimized amount of ZrO2 in the modified α-Fe2O3 photoanode. To the best of our knowledge, this is the highest photocurrent reported for a ZrO2 containing photoanode. The optimized composite electrode produced nine times more oxygen than that produced by pristine hematite.

Ab initio insight into the physical properties of MgXH3 (X = Co, Cu, Ni) lead-free perovskite for hydrogen storage application

Renewable energy systems are vital for a sustainable future, where solid-state hydrogen storage can play a crucial role. Perovskite hydride materials have attracted the scientific community for hydrogen storage applications. The current work focuses on the theoretical study using density functional theory (DFT) to evaluate the characteristics of MgXH3 (X = Co, Cu, Ni) hydrides. The structural, vibrational, electronic, mechanical, thermodynamic, and hydrogen storage properties of these hydrides were investigated. The equilibrium lattice parameters were calculated using the Birch-Murnaghan equation of state-to-energy volume curves. The elastic constants (Cij) and relevant parameters, such as Born criteria, were calculated to confirm the mechanical stability of the hydrides. The Cauchy pressure (Cp) revealed brittle or ductile behavior. The outcomes of the Pugh ratio, Poisson ratio, and anisotropy were also calculated and discussed. The absence of negative lattice vibrational frequencies in phonon dispersion confirmed the lattice's dynamic stability. The heat capacity curves of thermodynamic properties revealed that hydrides can conduct thermal energy. The metallic character and ample interatomic distances of hydrides were confirmed by the band structure and population analysis, which confirmed that hydrides can conduct electrical energy and adsorb hydrogen. The density of state (DOS) and partial DOS unveiled the role of specific atoms in the DOS of the crystal. The calculated gravimetric hydrogen storage capacity of MgCoH3, MgCuH3, and MgNiH3 hydrides was 3.64, 3.32, and 3.49wt%, respectively. Our results provide a deeper understanding of its potential for hydrogen storage applications through a detailed analysis of MgXH3 (X = Co, Cu, Ni) perovskite hydride material.

Outcomes of Children Diagnosed with Unilateral Retinoblastoma: Retrospective Audit

PURPOSE/OBJECTIVE(S)

To evaluate treatment outcomes of children diagnosed with unilateral retinoblastoma.

MATERIALS/METHODS

Retrospective study of children diagnosed with unilateral retinoblastoma registered at the Tata Memorial Hospital (TMH), Mumbai from January 2013 to December 2018 and completed the planned curative treatment protocol.

RESULTS

For the 98 cases that were analyzed, the median age of presentation was 24 months. The majority of patients had the intraocular disease (n = 72), whereas orbital retinoblastoma was in 26 patients. At the time of presentation, on imaging extra scleral spread was observed in 16 patients whereas 18 patients had optic nerve involvement, 11 patients had both extra scleral invasion and optic nerve involvement. We used the International Classification of Retinoblastoma for grouping. Out of 98 patients, 71 patients were in Group E, 21 were in Group D and 4 were in Group B and 2 were in Group C. For Staging of Retinoblastoma, we used International Retinoblastoma Staging System (IRSS) in our study and 14 patients had Stage 0 disease, 52 patients had Stage I disease, 10 patients had Stage II, 21 patients had Stage III A and 1 patient had Stage III B disease. High-risk features on surgical specimen histopathology were optic nerve cut margin positive in 6 patients, optic nerve involvement in 21 patients, extra scleral spread in 3 patients, Choroidal invasion in 38 and Iris involvement in 10 patients. Primary enucleation was offered in 52 patients whereas 26 patients underwent secondary enucleation. Systemic chemotherapy was received by the patient in the neoadjuvant setting in 17 patients as a form of chemo-reduction and 51 patients received systemic chemotherapy in the adjuvant setting. Intra-arterial chemotherapy was offered to 27 patients as a primary treatment or in conjugation with focal therapy (n = 11). Definitive radiotherapy was offered to only 2 patients and 22 patients received adjuvant radiotherapy. At a median follow-up of 62 months, 2patients had local relapse, which was salvaged by focal therapy in one and enucleation in the other. Ten patients who had leptomeningeal relapse had died. The 5-year local control (LC) is 97.6%, event-free survival (EFS) is 88% and overall survival (OS) is 89.5%. Globe was salvaged in only 16 cases. On univariate analysis, we observed a significant association between overall survival and extraocular and intraocular disease (p-value 0.0), Extra scleral spread (p-value 0.0), optic Nerve involvement (imaging), and an optic nerve cut margin positive (p-value 0.045), ICRB Groups (p-value 0.0) and IRSS stage (p- value 0.024).

CONCLUSION

Retinoblastoma is curable if detected early. Extra ocular disease and high-risk features are associated with inferior outcomes and poor globe salvage rates.

Evidence of novel Treponema phylotypes implicated in contagious ovine digital dermatitis and association of treponemes with major lameness causing foot pathogens

In this study 269 swabs collected from 254 ovine foot lesions and 15 apparently healthy ovine feet were screened by PCR for the presence of major lameness causing foot pathogens viz. Treponema species, D. nodosus, F. necrophorum and T. pyogenes with the presumption that ovine foot lesion positive for Treponema species alone or in association with other three pathogens were categorized as contagious ovine digital dermatitis (CODD). While samples positive for D. nodosus alone or its combination with F. necrophorum and T. pyogenes were considered as footrot (FR) and samples in which F. necrophorum or T. pyogenes was found either alone or in combination were considered as interdigital dermatitis (ID). The overall occurrence of Treponema sp. in ovine foot lesions was 48.0%, and ranged from 33 to 58%. In Treponema positive samples D. nodosus, F. necrophorum and T. pyogenes were present in 34 (27.4%), 66 (54.4%) and 84 (68.5%) in contrast to Treponema negative samples in which these were present in 15 (11.1%), 20 (14.12%) and 17 (12.6%) samples, respectively. The data signifies that Treponema sp. are significantly associated with these foot pathogens and their different combinations with Treponema sp. influence the severity of CODD lesion. The identification of Treponema phylotypes was done by sequencing the 16S rRNA gene fragment of ten representative samples. Out of ten sequences, four (Trep-2, Trep-4, Trep-7 and Trep-10) were identical to Treponema sp. phylotype 1 (PT1) that belongs to phylogroup T. refringens-like, one sequence (Trep-1) was genetically close (90% sequence homology) to Treponema brennaborense while five sequences (Trep-3, Trep-5, Trep-6, Trep-8 and Trep-9) matched with uncultured bacterium clones of treponemes forming separate monophyletic group in phylogenetic tree and could represent new digital dermatitis phylogroup presently containing five ovine specific phylotypes. This is the first report on the presence of Treponema phylotypes other than three digital dermatitis (DD) Treponema phylogroups viz. T. phagedenis-like, T. medium/T. vincentii-like, and T. pedis-like that are frequently detected in CODD lesions. Metagenomic analysis of two representative samples revealed the abundance of genus Treponema in CODD lesion while this genus was absent in swab collected from clinically healthy foot suggesting that it might play primary role in producing CODD. These findings may further aid in understanding the etiopathogenesis of CODD and could help to develop appropriate treatment and mitigation strategies to combat the disease.

Post-Traumatic Growth Among Frontline Doctors Fighting Against COVID-19 At A Tertiary Care Public Hospital In Karachi, Pakistan

Objective

To evaluate post-traumatic growth experienced by medical doctors who served coronavirus disease 2019 patients.

METHODS

The cross-sectional study was conducted from December 1, 2021, to February 28, 2022, at the Civil Hospital, Karachi, and comprised medical doctors of either gender aged >22 years who directly provided care for at least one month to coronavirus disease-2019 patients. Other than demographic and professional profile of the subjects, data was collected using the Post-Traumatic Growth Inventory, with total score ≥60 indicating a positive post-traumatic growth. Data was analysed using SPSS 22.

RESULTS

Of the 166 subjects approached, 150(90.3%) finished the study. There were 90(60%) females, 88(58.7%) were aged 25-35 years, 55(36.7%) were married, 107(71.3%) were postgraduate trainees, 79(52.7%) had 1-3 family members in the vulnerable groups, and 43(28.7%) had received any sort of psychological training. The mean post traumatic growth score was 64.81±20.27 and 87(58%) doctors scored ≥60. The odds of experiencing post- traumatic growth for doctors with the number of vulnerable family members were significant (p<0.05). Doctors who had received psychological training before providing care to coronavirus disease-2019 patients showed higher odds of experiencing post-traumatic growth (p<0.05).

Conclusion

Coronavirus disease-2019 resulted in substantial positive psychological growth for frontline doctors. Psychological training showed a significant role in post-traumatic growth.

A novel microfluidic compact disc to investigate electrochemical property changes between artificial and real salivary samples mixed with mouthwashes using electrical impedance analysis

Diagnosing oral diseases at an early stage may lead to better preventive treatments, thus reducing treatment burden and costs. This paper introduces a systematic design of a microfluidic compact disc (CD) consisting of six unique chambers that run simultaneously from sample loading, holding, mixing and analysis. In this study, the electrochemical property changes between real saliva and artificial saliva mixed with three different types of mouthwashes (i.e. chlorhexidine-, fluoride- and essential oil (Listerine)-based mouthwashes) were investigated using electrical impedance analysis. Given the diversity and complexity of patient's salivary samples, we investigated the electrochemical impedance property of healthy real saliva mixed with different types of mouthwashes to understand the different electrochemical property which could be a foundation for diagnosis and monitoring of oral diseases. On the other hand, electrochemical impedance property of artificial saliva, a commonly used moisturizing agent and lubricant for the treatment of xerostomia or dry mouth syndrome was also studied. The findings indicate that artificial saliva and fluoride-based mouthwash showed higher conductance values compared to real saliva and two other different types of mouthwashes. The ability of our new microfluidic CD platform to perform multiplex processes and detection of electrochemical property of different types of saliva and mouthwashes is a fundamental concept for future research on salivary theranostics using point-of-care microfluidic CD platform.

Can Honey Improve the Quality of Cryopreserved Cross Bred Ram Semen Added to Tris Egg Yolk Extender?

BACKGROUND: Honey can improve the quality of cryopreserved ram semen because of its multinutrient and cryoprotective nature added to standard tris egg yolk extender. OBJECTIVE: Different concentrations of honey were added to the standard tris egg yolk extender to improve the post-thaw quality of crossbred ram semen. METHOD: Thirty six (36) ejaculates from eight healthy cross bred rams were pooled and divided into four aliquots. Standard tris egg yolk extender without any alteration acted as Control (C) and was supplemented with different concentrations of honey, viz. T1 (honey 1.5%), T2 (2.5%), and T3 (3.5%). RESULTS: The percent (mean ± S. E. M) sperm motility at pre-freeze was significantly (P<;0.05) higher in Group T2 and at post-thaw in Group T3 in comparison to T1 and C treatment groups. The percent (mean ± S. E. M) HOST reacted spermatozoa at post-thaw was significantly (P< 0.05) higher in Group C and at pre-freeze the value was significantly (P< 0.05) higher in the same treatment group than Group T1. The mean MDA level (mean ± S. E. M) at post thaw was significantly (P<0.05) low er in Group T3 than the treatment groups C and Group T1. CONCLUSION: From this study it is concluded that the addition of 3.5% honey to the standard tris egg yolk extender provides better protection to ram semen than the addition of 1.5% honey (i. e., Control).

Can honey improve the quality of cryopreserved cross bred ram semen added to tris egg yolk extender?

BACKGROUND

Honey can improve the quality of cryopreserved ram semen because of its multinutrient and cryoprotective nature added to standard tris egg yolk extender.

OBJECTIVE

Different concentrations of honey were added to the standard tris egg yolk extender to improve the post-thaw quality of crossbred ram semen.

METHOD

Thirty six (36) ejaculates from eight healthy cross bred rams were pooled and divided into four aliquots. Standard tris egg yolk extender without any alteration acted as Control (C) and was supplemented with different concentrations of honey, viz. T1 (honey 1.5%), T2 (2.5%), and T3 (3.5%).

RESULTS

The percent (mean ± S.E.M) sperm motility at pre-freeze was significantly (P < 0.05) higher in Group T2 and at post-thaw in Group T3 in comparison to T1 and C treatment groups. The percent (mean ± S.E.M) HOST reacted spermatozoa at post-thaw was significantly (P < 0.05) higher in Group C and at pre-freeze the value was significantly (P < 0.05) higher in the same treatment group than Group T1. The mean MDA level (mean ± S.E.M) at post thaw was significantly (P < 0.05) lower in Group T3 than the treatment groups C and Group T1.

CONCLUSION

From this study it is concluded that the addition of 3.5% honey to the standard tris egg yolk extender provides better protection to ram semen than the addition of 1.5% honey (i.e., Control). doi.org/10.54680/fr22610110212.

Bioactive scaffold (sodium alginate)-g-(nHAp@SiO2@GO) for bone tissue engineering

Globally, people suffering from bone disorders are steadily increasing and bone tissue engineering is an advanced approach to treating fractured and defected bone tissues. In this study, we have prepared polymeric nanocomposite by free-radical polymerization from sodium alginate, hydroxyapatite, and silica with different GO amounts. The porous scaffolds were fabricated using the freeze drying technique. The structural, morphological, mechanical, and wetting investigation was conducted by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, universal tensile machine, and water contact angle characterization techniques. The swelling, biodegradation, and water retention were also studied. The biological studies were performed (cell viability, cell adherence, proliferation, and mineralization) against osteoblast cell lines. Scaffolds have exhibited different pore morphology SAG-1 (pore size = 414.61 ± 56 μm and porosity = 81.45 ± 2.17 %) and SAG-4 (pore size = 195.97 ± 82 μm and porosity = 53.82 ± 2.45 %). They have different mechanical behavior as SAG-1 has the least compression strength and compression modulus 2.14 ± 2.35 and 16.51 ± 1.27 MPa. However, SAG-4 has maximum compression strength and compression modulus 13.67 ± 2.63 and 96.16 ± 1.97 MPa with wetting behavior 80.70° and 58.70°, respectively. Similarly, SAG-1 exhibited the least and SAG-4 presented maximum apatite mineral formation, cell adherence, cell viability, and cell proliferation against mouse pre-osteoblast cell lines. The increased GO amount provides different multifunctional materials with different characteristics. Hence, the fabricated scaffolds could be potential scaffold materials to treat and regenerate fracture bone tissues in bone tissue engineering.

Plaque Control Efficacy: Interdental Brushes versus Dental Floss

Aims: In this study, we compared plaque control efficacy between interdental brushes & dental floss for the prevention of periodontal disease (gingivitis). We also investigated the convenient method for plaque control among these two interdental cleaning methods in routine. Study Design:  Randomized clinical trial Place and Duration of Study: Department of Periodontology at Fatima Jinnah Dental College and Hospital, Karachi, Pakistan from Jan 2019 to July 2020. Methodology: The sample size of 180 was calculated using OpenEpi software each group (Interdental brush & Dental floss) carried 90 patients respectively at 95% confidence interval and 80% power of the test. Probability sampling technique was used. The Clinical trial was registered at ClinicalTrial.gov (Identifier: NCT05439785). Ethical approval was taken from the Ethical Review Committee of Ziauddin University (1130519MSOM). SPSS version 20 was used to analyze the study data. P-value ≤ 0.05 was considered as significant. Results: The statistical results showed significant improvement in the plaque score and bleeding index among patients pre and post intervention (p <0.001). Moreover, this study stated that interdental brush was slightly better in reducing interproximal plaque accumulation in patients of gingivitis (p <0.001). The symptom of bleeding from the gingival tissue was also improved by using both interdental cleaning methods.  The posterior region appeared to be a difficult site to use both the intervention (interdental brushes or dental floss). Both interdental cleaning methods assisted in the improvement of other symptoms like sensitivity, halitosis, and food impaction in the patients. Conclusion: The findings of our research revealed that both interdental cleaning methods had a statistically significant effect in removing interdental plaque, with little variation in plaque removal seen between interdental brush and dental floss when compared to baseline. This study endorses better outcome of interdental brush in reducing dental plaque accumulation than dental floss in the gingivitis patients.

The Measurement of Contact Angle, pH, and Conductivity of Artificial Saliva and Mouthwashes on Enamel, Glass-Ionomer, and Composite Dental Materials

The aim of this study was to tackle the topic of appropriate recommendations for artificial-saliva and mouthwash usage. The contact angle, pH, and conductivity of two artificial saliva solutions, four mouthwashes, and their mixtures on enamel, glass-ionomer, and composite dental materials were measured. The measurements were conducted with a MATLAB algorithm to minimize human error. The obtained values for the contact angle were in the range from 7.98° to 52.6°, and they showed completely nonlinear and nonuniform behavior for all investigated liquids and on all investigated substrates. Results reveal statistically significant differences among all tested liquids on all investigated substrates (p < 0.05). pH values ranged from 1.54 to 7.01. A wide range of conductivity values were observed, from 1205µS/cm in the saliva-stimulating solution to 6679 mS/cm in the artificial saliva. Spearman’s test showed a moderate positive correlation between the pH and conductivity of the tested fluids (R = 0.7108). A comparison of the data obtained using Image J software and the MATLAB algorithm showed consistency, not exceeding 5% error. When an experiment uses human material and bioactive materials THAT are used in biomedicine as substrates, an additional definition of protocols is highly recommended for future research on this topic.

Variegation in the Number of Islets of Langerhans in the Pancreas of Rats Fed on Sodium Cyclamate

Objective: To observe the effects of an artificial sweetener (sodium cyclamate) on a rat's pancreas and glucose levels. Study Design: Laboratory-based experimental study. Place and Duration of Study: Army Medical College Rawalpindi, in association with the National Institute of Health, Islamabad, Pakistan from Jun 2014 to Jan 2015. Methodology: Forty Sprague Dawley rats (male and female housed separately to avoid mating and pregnancy) were involved in the experiment. Twenty rats in each control and experimental group. C served as control and E for the experimental group. A normal laboratory diet was fed to control Group-C for two months, whereas through an oral gavage needle, artificial sweetener 60mg/kg/day (sodium cyclamate) was fed to experimental animals for two months. During the two months after twelve-hour fasting, rats' blood glucose level was recorded weekly. At the commencement and completion of these two months, the weight of the animals was noted. Results: Fasting blood sugars of experimental group was found to be statistically significant from week 3 to 9 with p-values of 0.034, <0.001, <0.001, 0.002, 0.001, <0.001, <0.001 respectively. Number of islets of Langerhans was significantly higher 13.70 ± 1.87μm in experimental group compared with control group with the p-value of <0.001. Conclusion: Sodium cyclamate not only affected the glucose metabolism but also disturbed the normal histology of the endocrine pancreas.

Multifunctional Arabinoxylan-functionalized-Graphene Oxide Based Composite Hydrogel for Skin Tissue Engineering

Wound healing is an important physiological process involving a series of cellular and molecular developments. A multifunctional hydrogel that prevents infection and promotes wound healing has great significance for wound healing applications in biomedical engineering. We have functionalized arabinoxylan and graphene oxide (GO) using the hydrothermal method, through cross-linking GO-arabinoxylan and polyvinyl alcohol (PVA) with tetraethyl orthosilicate (TEOS) to get multifunctional composite hydrogels. These composite hydrogels were characterized by FTIR, SEM, water contact angle, and mechanical testing to determine structural, morphological, wetting, and mechanical behavior, respectively. Swelling and biodegradation were also conducted in different media. The enhanced antibacterial activities were observed against different bacterial strains (E. coli, S. aureus, and P. aeruginosa); anticancer activities and biocompatibility assays were found effective against U-87 and MC3T3-E1 cell lines due to the synergic effect of hydrogels. In vivo activities were conducted using a mouse full-thickness skin model, and accelerated wound healing was found without any major inflammation within 7 days with improved vascularization. From the results, these composite hydrogels might be potential wound dressing materials for biomedical applications.

A review on sensing and catalytic activity of nano-catalyst for synthesis of one-step ammonia and urea: Challenges and perspectives

One of the most significant chemical operations in the past century was the Haber-Bosch catalytic synthesis of ammonia, a fertilizer vital to human life. Many catalysts are developed for effective route of ammonia synthesis. The major challenges are to reduce temperature and pressure of process and to improve conversion of reactants produce green ammonia. The present review, briefly discusses the evolution of ammonia synthesis and current advances in nanocatalyst development. There are promising new ammonia synthesis catalysts of different morphology as well as magnetic nanoparticles and nanowires that could replace conventional Fused-Fe and Promoted-Ru catalysts in existing ammonia synthesis plants. These magnetic nanocatalyst could be basis for the production of magnetically induced one-step green ammonia and urea synthesis processes in future.

Silver Conductive Threads-Based Embroidered Electrodes on Textiles as Moisture Sensors for Fluid Detection in Biomedical Applications

Wearable sensors have become part of our daily life for health monitoring. The detection of moisture content is critical for many applications. In the present research, textile-based embroidered sensors were developed that can be integrated with a bandage for wound management purposes. The sensor comprised an interdigitated electrode embroidered on a cotton substrate with silver-tech 150 and HC 12 threads, respectively, that have silver coated continuous filaments and 100% polyamide with silver-plated yarn. The said sensor is a capacitive sensor with some leakage. The change in the dielectric constant of the substrate as a result of moisture affects the value of capacitance and, thus, the admittance of the sensor. The moisture sensor's operation is verified by measuring its admittance at 1 MHz and the change in moisture level (1-50) µL. It is observed that the sensitivity of both sensors is comparable. The identically fabricated sensors show similar response and sensitivity while wash test shows the stability of sensor after washing. The developed sensor is also able to detect the moisture caused by both artificial sweat and blood serum, which will be of value in developing new sensors tomorrow for smart wound-dressing applications.

FEM Analysis of Various Multilayer Structures for CMOS Compatible Wearable Acousto-Optic Devices

Lately, wearable applications featuring photonic on-chip sensors are on the rise. Among many ways of controlling and/or modulating, the acousto-optic technique is seen to be a popular technique. This paper undertakes the study of different multilayer structures that can be fabricated for realizing an acousto-optic device, the objective being to obtain a high acousto-optic figure of merit (AOFM). By varying the thicknesses of the layers of these materials, several properties are discussed. The study shows that the multilayer thin film structure-based devices can give a high value of electromechanical coupling coefficient (k2) and a high AOFM as compared to the bulk piezoelectric/optical materials. The study is conducted to find the optimal normalised thickness of the multilayer structures with a material possessing the best optical and piezoelectric properties for fabricating acousto-optic devices. Based on simulations and studies of SAW propagation characteristics such as the electromechanical coupling coefficient (k2) and phase velocity (v), the acousto-optic figure of merit is calculated. The maximum value of the acousto-optic figure of merit achieved is higher than the AOFM of all the individual materials used in these layer structures. The suggested SAW device has potential application in wearable and small footprint acousto-optic devices and gives better results than those made with bulk piezoelectric materials.

133 Incidence of Imaging Confirmed Stroke and Thrombotic Events in Older Adults with Severe COVID-19 Infection

 

During the initial phase of the response to COVID-19, concern was raised regarding a potential link with increased risk of stroke. We aimed to explore the incidence of stroke and thrombotic events within our local population with COVID-19 infection who required admission to the Intensive Care Unit (ICU).

Methods

Retrospective analysis of 57 consecutive patients with a diagnosis of COVID-19 infection admitted to Barnet General Hospital ICU between 6th March and 26th April 2020. Cases were reviewed to establish whether there had been imaging (CT or MRI) confirmed ischaemic stroke, intra-cerebral haemorrhage (ICH), venous sinus thrombosis (VST) or other thrombotic event, including pulmonary embolism (PE). Data was collected on baseline characteristics and blood tests including D-Dimer levels. Statistical analysis was performed using two-tailed t-test and Fischer’s exact test (FET). Findings: Nineteen patients (33%) were age 65 years or older (mean age 69, range 65 to 74 years) and of these 2 patients (10.5%) had imaging confirmed acute ischaemic stroke. In those under 65 (mean age 54, range 29–64 years) there was one confirmed ICH and one VST. The incidence of PE was 21% in both groups. Survival was significantly lower in the age 65 or older group (26.3% versus 63.2%, p = 0.0119 (FET)). Peak recorded D-Dimer levels also appeared to be significantly higher in the age 65 or older group (p = 0.0003, 95% CI 13068.89 to 39858.68).

Conclusions and limitations

These findings highlight the importance of awareness of risk of thrombotic events, including acute stroke, in older adults with severe Covid-19 infection. It is possible that the incidence of stroke was underestimated, including due to challenges identifying clinical signs of acute stroke and safely obtaining imaging in this population. Further, ideally prospective, studies are required to more clearly elucidate the degree of association between COVID-19 infection and stroke and VST.

Lumbar Spinal Fusion Using Lateral Oblique (Pre-psoas) Approach (Review)

Lumbar spinal fusion is one of the most common operations in spinal surgery. For its implementation, anterolateral (pre-psoas) approach (oblique lumbar interbody fusion, OLIF) is now increasingly used due to its high efficacy and safety. However, there is still little information on the clinical and radiological results of using this technique.

The aim of the study was to analyze the safety and efficacy of OLIF in the treatment of lumbar spine disorders as presented in the literature.

Genotyping and antibiotic resistance patterns of Campylobacter fetus subsp.venerealis from cattle farms in India

Bovine genital campylobacteriosis caused by Campylobacter fetus subsp. venerealis (Cfv) is of considerable economic importance to the cattle industry worldwide. Cfv causes syndrome of temporary infertility in female cattle, early embryonic mortality, aberrant oestrus cycles, delayed conception, abortions and poor calving rates. In the present study, a total of 200 samples obtained from vaginal swabs, cervicovaginal mucous (CVM), preputial washes and semen straws were investigated that were obtained from organized cattle farm of MLRI, Manasbal and unorganized sectors. Out of a total of 200 samples, 49 (47·57%) vaginal swabs, 1 (3·33%) preputial wash and 8 (25%) carried out CVM samples were positive for Cfv, whereas none of the semen straws were positive for Cfv. A total of eleven isolates of Cfv were recovered. PFGE (Pulse field gel electrophoresis) analysis revealed four different pulsotypes (I-IV) circulating in the screened farms. A common pulsotype circulating among farms could not be established. Insertion element (ISCfe1), a 233 bp amplicon of Cfv, was sequenced and the sequence was deposited in GenBank (accession no: MK475662).

Late Intraocular Lens Dislocation Resulting From Haptic Breakage Following Cardiopulmonary Resuscitation

We report a case of an asymptomatic 65-year-old male who on routine eye examination had anterior dislocation of an intraocular lens (IOL) implant placed 23 years prior. Ten months prior to presentation, the patient had cardiac surgery complicated by cardiac arrest requiring chest compressions. Dislocation of an intraocular lens is a rare complication of cataract surgery. One of the causative factors for haptic breakage in our case was the polyimide haptic material. Polyimide has been shown to become brittle over time in warm and moist environments such as the human eye. This case demonstrates a case of late IOL dislocation chest compressions and, to the best of our knowledge, the first such case reported in the literature.

FRI0448 FOUR CASES OF SYPHILIS MIMICKING RHEUMATOLOGICAL CONDITIONS PRESENTING TO THE GENERAL RHEUMATOLOGY SERVICE AT ST GEORGES HOSPITAL, LONDON, UK IN 2018-2019

Background:

Sir William Osler once wrote: “He, who knows syphilis, knows medicine”.

Whilst the Tuskegee Syphilis trials live in infamy, the advent of succesful penicillin treatment and sexual health education resulted in the lowest recorded incidence ever in 20011.

Unfortunately, cases of syphilis have nearly tripled in the past decade (from 2,847 in 2009 to 7,541 in 2018 in the UK)1. WHO now estimates the global median prevalence of Syphilis, among men who have sex with men, is 6%2

The current cohort of clinicians will therefore have limited clinical experience of Syphilis, which can often mimic rheumatic conditions. We present the clinical experience of a tertiary teaching centre hospital.

Objectives:

To identify the scope of clinical cases, with a diagnosis of Syphilis, during 2018-2019 at St Georges University Hospital, London, UK.

Methods:

Clinical cases were identified by health professionals and a retrospective review of medical records was undertaken.

Results:

There were 4 cases identified during 2018-19.

PatientAgeSexPast Medical HistorySymptomatologyRisk FactorsPresumed DiagnosisSerology169MaleHypertensionGCABilateral visual loss, rashMSMPrednisoloneTocilizumabGCA-related visual lossRPR 1:64TPPA 1: 10248246FemaleNilJoint pain and swelling, rashHepatitis B Core Antibody positiveUndifferentiatedInflammatory ArthritisRPR 1: 16340MaleNilJoint pain, alopecia, uveitis and rash, weight lossMSMPrimary SyphilisRPR 1: 16TPPA 1: 10248486FemalePulmonary Sarcoidosis, Squamous cell carcinoma of left maxillary sinusLower motor neuron facial nerve palsyPrednisoloneSarcoidosisRPR 1:4TPPA 1:80

GCA: Giant cell arteritis, MSM: Men who have sex with men, RPR: rapid plasma regain, TPPA: Treponema pallidum particle agglutination assay

Case 1:The patient was diagnosed with bilateral uveitis secondary to primary syphilis, and immunosuppression may have contributed to this.

Case 2:The rash developed after the initial presentation and an extended infection screen was performed.

Case 3:The patient had a 6 month duration of symptoms and had had a negative sexual health screen 1 year prior to presentation.

Case 4:The patient had no features of extra pulmonary sarcoidosis and an infectious screen was undertaken.

All 4 cases were referred to the Infectious Disease Unit for treatment. 3 patients received standard treatment with Penicillin, and 1 patient received an oral course of Doxycycline, due to a penicillin allergy.

2 of the 4 cases had complete resolution of symptoms, and 2 of the cases had only partial resolution of symptoms at the time of publication.

Conclusion:

Syphilis can present with an inflammatory arthritis, PMR and GCA –type symptoms, ocular inflammation, neurological disturbance and rashes that can mimic autoimmune conditions.

Our cases highlight the increasing incidence, as well as the risk of reactivation following immunosuppression. Current practice does not advise routine testing for syphilis prior to initiation of immunosuppressive therapy. However the rising incidence should prompt careful evaluation, and detailed sexual history, particularly in high risk groups. The diagnostic test interpretation and treatment requires close collaboration with Infectious Diseases Specialists.

References:

[1]https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/805903/2018_Table_1_STI_diagnoses_and_rates_in_England_by_gender.ods

[2]Report on global sexually transmitted infection surveillance 2018, WHO, ISBN: 978-92-4-156569-1

Disclosure of Interests:

None declared

HPV sampling options for cervical cancer screening: preferences of urban-dwelling Canadians in a changing paradigm

Introduction

Of women in Canada diagnosed with invasive cervical cancer, 50% have not been screened according to guidelines. Interventions involving self-collected samples for human papillomavirus (hpv) screening could be an avenue to increase uptake. To guide the development of cervical cancer screening interventions, we assessed ■ preferred sample collection options,■ sampling preferences according to previous screening behaviours, and■ preference for self-sampling among women not screened according to guidelines, as a function of their reasons for not being screened.

Methods

Data were collected in an online survey (Montreal, Quebec; 2016) and included information from female participants between the ages of 21 and 65 years who had not undergone hysterectomy and who had provided answers to survey questions about screening history, screening interval, and screening preferences (n = 526, weighted n = 574,392).

Results

In weighted analyses, 68% of all women surveyed and 82% of women not recently screened preferred screening by self-sampling. Among women born outside of Canada, the United States, or Europe, preference ranged from 47% to 60%. Nearly all women (95%-100%) who reported fear or embarrassment, dislike of undergoing a Pap test, or lack of time or geography-related availability of screening as one of their reasons for not being screened stated a preference for undergoing screening by self-sampling.

Conclusions

The results demonstrate a strong preference for self-sampling among never-screened and not-recently-screened women, and provides initial evidence for policymakers and researchers to address how best to integrate self-sampling hpv screening into both organized and opportunistic screening contexts.

Rising prevalence of multiple sclerosis in Saudi Arabia, a descriptive study

BACKGROUND

In 2015, the first nationwide, multicenter Multiple Sclerosis (MS) registry was initiated in the Kingdom of Saudi Arabia (KSA) mainly with an objective to describe current epidemiology, disease patterns, and clinical characteristics of MS in Saudi Arabia. This article aimed to report initial findings of the registry and regional prevalence of MS.

METHOD

In 2015, a national MS registry was launched in KSA to register all MS patient with confirmed diagnosis according to the 2010 McDonald Criteria. The registry aimed to identify and recruit all healthcare facilities treating MS patients in the Kingdom, and collect data such as demographics, clinical characteristics (disease onset, diagnosis, presentation of symptoms at onset, disease course, relapse rate, and disability measures), family history, and treatments. All the included sites have obtained IRB/EC approvals for participating in the registry. Currently, the registry includes 20 hospitals from different regions across the Kingdom. The Projected prevalence was calculated based on the assumption that the number of diagnosed MS cases in participating hospitals (in each region) is similar to the number of cases in remaining nonparticipant hospitals in the same region.

RESULTS

As of September 2018, the registry has included 20 hospitals from the different regions across the Kingdom and has collected comprehensive data on 2516 patients from those hospitals, with median age 32 (Range: 11-63) and 66.5% being females. The reported prevalence of MS for those hospitals was estimated to be 7.70/100,000 population and 11.80/100,000 Saudi nationals. Based on the assumption made earlier, we projected the prevalence for each region and for the country as a whole. The overall prevalence of MS at the country level was reported to be 40.40/100,000 total population and 61.95/100,000 Saudi nationals. Around 3 out of every 4 patients (77.5%) were 40 years of age or younger. Female to male ratio was 2:1. The prevalence was higher among females, young and educated individuals across all five regions of Saudi Arabia.

CONCLUSION

The prevalence of MS has significantly increased in Saudi Arabia but is still much lower than that in the western and other neighboring countries like Kuwait, Qatar, and the UAE. However, compared to the past rates, Saudi Arabia's projected prevalence of MS through this national study is 40.40/100,000 population, putting the Kingdom above the low risk zone as per Kurtzke classification. The projected prevalence was estimated to be much higher among Saudi nationals (61.95/100,000 Saudi-nationals). The prevalence was higher among female, younger and educated individuals. Further studies are needed to assess the risk factors associated with increased prevalence in Saudi Arabia.

Complications in implant dentistry

After tooth loss, an individual may seek tooth replacement so that his/her function and esthetics could be restored. Clinical prosthodontics, during the past decade, has significantly improved and developed according to the advancements in the science and patient's demands and needs. Conventional options in prosthodontics for substituting a missing single tooth include the removable partial denture, partial and full coverage bridgework, and resin-bonded bridgework. Dental implants have gained increasing popularity over the years as they are capable of restoring the function to near normal in both partial and completely edentulous arches. With substantial evidence available, fixed implant-supported prosthesis are fully acknowledged as a reliable treatment option for the replacement of single or multiple missing teeth nowadays. While dental implants are increasingly becoming the choice of replacement for missing teeth, the impediments associated with them are progressively emerging too.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Randomized trial of red cell washing for the prevention of transfusion-associated organ injury in cardiac surgery

Background. Experimental studies suggest that mechanical cell washing to remove pro-inflammatory components that accumulate in the supernatant of stored donor red blood cells (RBCs) might reduce inflammation and organ injury in transfused patients.

Methods. Cardiac surgery patients at increased risk of large-volume RBC transfusion were eligible. Participants were randomized to receive either mechanically washed allogenic RBCs or standard care RBCs. The primary outcome was serum interleukin-8 measured at baseline and at four postsurgery time points. A mechanism substudy evaluated the effects of washing on stored RBCs in vitro and on markers of platelet, leucocyte, and endothelial activation in trial subjects.

Results. Sixty adult cardiac surgery patients at three UK cardiac centres were enrolled between September 2013 and March 2015. Subjects received a median of 3.5 (interquartile range 2–5.5) RBC units, stored for a mean of 21 (sd 5.2) days, within 48 h of surgery. Mechanical washing reduced concentrations of RBC-derived microvesicles but increased cell-free haemoglobin concentrations in RBC supernatant relative to standard care RBC supernatant. There was no difference between groups with respect to perioperative serum interleukin-8 values [adjusted mean difference 0.239 (95% confidence intervals −0.231, 0.709), P=0.318] or concentrations of plasma RBC microvesicles, platelet and leucocyte activation, plasma cell-free haemoglobin, endothelial activation, or biomarkers of heart, lung, or kidney injury.

Conclusions. These results do not support a hypothesis that allogenic red blood cell washing has clinical benefits in cardiac surgery.

Clinical trial registration. ISRCTN 27076315.

Study of early post-operative complications in relation to nature of anaesthesia and type of surgery

Background: Many people have complications after surgery; some transient, others serious, but all are important to patients. The likelihood of postoperative complications is influenced by the type of surgery, the patients pre-existing comorbid state and perioperative management. Anaesthesia result in a variety of metabolic and endocrine responses, but conventional wisdom maintains that anaesthetic technique has little long-term effect on patient outcomes. There is accumulating evidence that, on contrary, anaesthetic management may in fact exert a number of longer-term effects in postoperative outcome.Methods: A prospective study of early post-operative complication in 100 patients’, who underwent major surgery, was done in the Department of Surgery in a tertiary care teaching hospital, Indore. Therefore, the present study was carried out prospectively to study the incidence of postoperative complications in relation to age, sex and other factors which influence them and correlation of post-operative complications with the nature of anaesthesia, duration of operation, type of surgery and in surgery above diaphragm or below diaphragm.Results: The incidence of post-operative complications was more in patients operated with general anaesthesia (48.38% and 12.9% respectively) the morbidity and mortality in patients who were operated under spinal anaesthesia was lower than general anaesthesia, but morbidity was higher in patients who were operated under epidural anaesthesia, but mortality was lower than epidural.Conclusions: There is accumulating evidence that anaesthetic management may indeed exert a number of influences on longer term postoperative outcomes. Further prospective, randomized, large scale, human trials with long- term follow-up are required to clarify the association between anaesthesia technique and postoperative outcome.

Isolation and genome analysis of a lytic Pasteurella multocida Bacteriophage PMP-GAD-IND

Currently used alum precipitated and oil adjuvant vaccines against HS caused by Pasteurella multocida B:2, have side effects and short-lived immunity, leading to regular catastrophic outbreaks in bovines in Asian subcontinent. The need for the development of an improved vaccine with longer immunity and the ability to differentiate between vaccinated and infected is essential. Pasteurella phage isolated in present study belongs to family Siphoviridae. PMP-GAD-IND phage exhibited lytic activity against vaccine strain (P52) as well as several field strains of P. multocida (B:2), and fowl cholera agent (P. multocida A:1).The phage has a double stranded DNA (dsDNA) with a genome of 46 335 bp. The complete genome sequence of the Pasteurella multocida phage has been deposited in Gen Bank with accession no: KY203335. PMP-GAD-IND being a lytic phage with broad activity range has a potential to be used in therapy against multidrug resistant P. multocida infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present work is a part of research for the development of an improved phage lysate marker vaccine and a companion DIVA assay against haemorhagic septicaemia. This study describes the isolation and genome analysis of PMP-GAD-IND a lytic Pasteurella multocida bacteriophage.

Developing culturally adapted lifestyle interventions for South Asian migrant populations: a qualitative study of the key success factors and main challenges

OBJECTIVES

South Asian migrant populations have a high risk of non-communicable diseases, such as type 2 diabetes (T2D). The aim of this study is to provide in-depth insight into key success factors and challenges in developing culturally adapted lifestyle interventions to prevent T2D within South Asian migrant populations.

STUDY DESIGN

The study has a qualitative research design.

METHODS

In-depth interviews, using a semi-structured interview guide, were conducted with eight researchers and project leaders from five studies of culturally adapted lifestyle interventions for South Asian migrant populations. Data were analysed using a grounded theory approach.

RESULTS

Four main themes emerged as key factors for success: 'approaching the community in the right way', 'the intervention as a space for social relations', 'support from public authorities' and 'being reflexive and flexible'. Two themes emerged as challenges: 'struggling with time' and 'overemphasising cultural differences'.

CONCLUSIONS

Our findings augment existing research by establishing the importance of cooperation at the organisational and institutional levels, of fostering the creation of social networks through interventions and of acknowledging the multiplicity of identities and resources among individuals of the same ethnic origin.

Restricting feeding to the active phase in middle-aged mice attenuates adverse metabolic effects of a high-fat diet

Time-restricted feeding ameliorates the deleterious effects of a high-fat diet on body weight and metabolism in young adult mice. Because obesity is highly prevalent in the middle-aged population, this study tested the hypothesis that time-restricted feeding alleviates the adverse effects of a high-fat diet in male middle-aged (12months) mice. C57BL6/J mice were fed one of three diets for 21-25weeks: 1) high-fat diet (60% total calories from fat) ad-libitum (HFD-AL), 2) HFD, time-restricted feeding (HFD-TRF), and 3) low-fat diet (10% total calories from fat) ad-libitum (LFD-AL) (n=15 each). HFD-TRF mice only had food access for 8h/day during their active period. HFD-TRF mice gained significantly less weight than HFD-AL mice (~20% vs 55% of initial weight, respectively). Caloric intake differed between these groups only during the first 8weeks and accounted for most but not all of their body weight difference during this time. TRF of a HFD lowered glucose tolerance in terms of incremental area under the curve (iAUC) (p<0.02) to that of LFD-AL mice. TRF of a HFD lowered liver weight (p<0.0001), but not retroperitoneal or epididymal fat pad weight, to that of LFD-AL mice. Neither HFD-AL nor HFD-TRF had any effect on performance in the novel object recognition or object location memory tests. Circulating corticosterone levels either before or after restraint stress were not affected by diet. In conclusion, TRF without caloric restriction is an effective strategy in middle-aged mice for alleviating the negative effects of a HFD on body weight, liver weight, and glucose tolerance.

Extended interval dosing of natalizumab in multiple sclerosis

BACKGROUND

Natalizumab (NTZ), a monoclonal antibody to human α4β1/β7 integrin, is an effective therapy for multiple sclerosis (MS), albeit associated with progressive multifocal leukoencephalopathy (PML). Clinicians have been extending the dose of infusions with a hypothesis of reducing PML risk. The aim of the study is to evaluate the clinical consequences of reducing NTZ frequency of infusion up to 8 weeks 5 days.

METHODS

A retrospective chart review in 9 MS centres was performed in order to identify patients treated with extended interval dosing (EID) regimens of NTZ. Patients were stratified into 3 groups based on EID NTZ treatment schedule in individual centres: early extended dosing (EED; n=249) every 4 weeks 3 days to 6 weeks 6 days; late extended dosing (LED; n=274) every 7 weeks to 8 weeks 5 days; variable extended dosing (n=382) alternating between EED and LED. These groups were compared with patients on standard interval dosing (SID; n=1093) every 4 weeks.

RESULTS

17% of patients on SID had new T2 lesions compared with 14% in EID (p=0.02); 7% of patients had enhancing T1 lesions in SID compared with 9% in EID (p=0.08); annualised relapse rate was 0.14 in the SID group, and 0.09 in the EID group. No evidence of clinical or radiographic disease activity was observed in 62% of SID and 61% of EID patients (p=0.83). No cases of PML were observed in EID group compared with 4 cases in SID cohort.

CONCLUSIONS

Dosing intervals up to 8 weeks 5 days did not diminish effectiveness of NTZ therapy. Further monitoring is ongoing to evaluate if the risk of PML is reduced in patients on EID.

Anesthetic management of a patient with Weaver syndrome undergoing emergency evacuation of extra-dural hematoma: A case report and review of the literature

Weaver syndrome is a rare disorder of unknown etiology characterized by skeletal overgrowth, distinctive craniofacial and digital abnormalities and advanced bone age. In general, craniofacial abnormalities that cause difficulty with tracheal intubation may improve, worsen, or remain unchanged as craniofacial structures mature. Furthermore, there is an estimated risk in these children of ≤1.09% of rhabdomyolysis or malignant hyperpyrexia. We report a case of a boy with Weaver syndrome who underwent emergency evacuation of extra-dural hematoma under general anesthesia.

Evaluating a murine model of endometritis using uterine isolates of Escherichia coli from postpartum buffalo

Ascending infection of the uterus with Gram-negative bacteria is responsible for postpartum endometritis in cattle and buffalo and can adversely affect fertility. Development of a laboratory animal model for bovine endometritis would facilitate the understanding of the pathogenesis as it is difficult to conduct controlled experimentation in the native host. In the present study, 30 virgin Swiss Albino mice (5-8 weeks old) were used to evaluate the pathogenic potential of Escherichia coli, isolated from the normally calved postpartum buffalo to induce endometritis. Mice in the diestrus phase of the estrous cycle were randomly allotted to one of the following four intravaginal inoculation (100 μL) treatments: EG (experimental group)-1: sterile normal saline; EG-2, -3 and -4: E. coli^@ 1.5 × 10⁴, 10⁵ and 10⁶ CFU/ml, respectively. The animals were then scarified 36 h post-inoculation to study gross and microscopical lesions. Gross changes were confined to EG-4. Acute endometritis was recorded in 50% of the EG-3 and 66.7% of the EG-4. The rate of acute endometritis development was significantly higher in EG-4 (P<0.05) as compared to the other groups. The present study demonstrated that the animal model for bubaline endometritis can be developed in mice by intravaginal inoculation of E.coli^@ 1.5 × 10⁶ CFU/ml at diestrus. Ease of intravaginal inoculation, apparent absence of systemic involvement and high infective rate are the advantages of the model over other studies.

Superbugs causing ventilator associated pneumonia in a tertiary care hospital and the return of pre-antibiotic era!

The rise in super bugs causing Ventilator-Associated Pneumonia (VAP) is a major cause of mortality and morbidity despite recent advances in management owing to the looming 'antibiotic apocalypse'. The aetiology and susceptibility pattern of the VAP isolates varies with patient population, type of intensive care unit (ICU) and is an urgent diagnostic challenge. The present study carried out for a period of one year in a tertiary care hospital, enrolled patients on mechanical ventilation (MV) for ≥48 hrs. Endotracheal aspirates (ETA) from suspected VAP patients were processed by semi quantitative method. Staphylococus aureus, members of Enterobacteriaceae were more common in early onset VAP (EOVAP), while Nonfermenting Gram negative bacilli (NFGNB) were significantly associated with late onset VAP (LOVAP). Most of the isolates were multi drug resistant (MDR) super bugs. With limited treatment options left for this crisis situation like the pre-antibiotic era; it is an alarm for rational antibiotic therapy usage and intensive education programs.

MPLA shows attenuated pro-inflammatory properties and diminished capacity to activate mast cells in comparison with LPS

BACKGROUND

Monophosphoryl lipid A (MPLA), a nontoxic TLR4 ligand derived from lipopolysaccharide (LPS), is used clinically as an adjuvant in cancer, hepatitis, and malaria vaccines and in allergen-specific immunotherapy. Nevertheless, its cell-activating effects have not been analyzed in a comprehensive direct comparison including a wide range of different immune cells. Therefore, the objective of this study was the side-by-side comparison of the immune-modulating properties of MPLA and LPS on different immune cells.

METHODS

Immune-activating properties of MPLA and LPS were compared in human monocytes and mast cells (MCs), a mouse endotoxin shock model (ESM), and mouse bone marrow (BM)-derived myeloid dendritic cells (mDCs), T cells (TCs), B cells, and MCs.

RESULTS

In a mouse in vivo ESM and a human ex vivo monocyte activation test (MAT), MPLA induced the same cytokine secretion pattern as LPS (ESM: IL-6, IL-12, TNF-α; MAT: IL-1β, IL-6, TNF-α), albeit at lower levels. Mouse mDCs and ex vivo isolated B cells stimulated with MPLA required a higher threshold to induce TRIF-dependent cytokine secretion (IL-1β, IL-6, IL-10, and TNF-α) than did LPS-stimulated cells. In mDC:DO11.10 CD4 TC cocultures, stimulation with MPLA, but not with LPS, resulted in enhanced OVA-specific IL-4 and IL-5 secretion from DO11.10 CD4 TCs. Unexpectedly, in both human and mouse MCs, MPLA, unlike LPS, did not elicit secretion of pro-inflammatory cytokines.

CONCLUSIONS

Compared to LPS, MPLA induced a qualitatively similar, but less potent pro-inflammatory immune response, but was unable to activate human or mouse MCs.