Characterising phagocytes and measuring phagocytosis from live Galleria mellonella larvae

Over the last 20 years, the larva of the greater waxmoth, Galleria mellonella, has rapidly increased in popularity as an in vivo mammalian replacement model organism for the study of human pathogens. Experimental readouts of response to infection are most often limited to observing the melanization cascade and quantifying larval death and, whilst transcriptomic and proteomic approaches, and methods to determine microbial load are also used, a more comprehensive toolkit of profiling infection over time could transform the applicability of this model. As an invertebrate, Galleria harbour an innate immune system comprised of both humoral components and a repertoire of innate immune cells - termed haemocytes. Although information on subtypes of haemocytes exists, there are conflicting reports on their exact number and function. Flow cytometry has previously been used to assay Galleria haemocytes, but protocols include both centrifugation and fixation - physical methods which have the potential to affect haemocyte morphology prior to analysis. Here, we present a method for live haemocyte analysis by flow cytometry, revealing that Galleria haemocytes constitute only a single resolvable population, based on relative size or internal complexity. Using fluorescent zymosan particles, we extend our method to show that up to 80% of the Galleria haemocyte population display phagocytic capability. Finally, we demonstrate that the developed assay reliably replicates in vitro data, showing that cell wall β-1,3-glucan masking by Candida albicans subverts phagocytic responses. As such, our method provides a new tool with which to rapidly assess phagocytosis and understand live infection dynamics in Galleria.

Dyslipidemia and heart failure: current evidence and perspectives of use of statins

Heart failure (HF) is a condition with growing morbidity and mortality. Dyslipidemia in HF is not concentrated around hypercholesterolemia as in coronary artery disease. As a corollary, the robust benefits seen with statins across the spectrum of CAD have not been replicated in HF. Multiple potential pleiotropic effects of statins include anti-inflammatory, antioxidant, endothelial stabilization, antiapoptotic, anti-thrombotic, and modulation of the autonomic system apart from lipid lowering. These benevolent actions need to be counterbalanced with the potential derangement of ubiquinone, selenoprotein and endotoxin pathways. While small randomized and non-randomized studies demonstrated a multitude of benefits in clinical and surrogate endpoints, two large RCTs failed to demonstrate unequivocal benefits. However, multiple large meta-analyses do demonstrate definite improvement in clinical endpoints including death and heart failure hospitalization. The clinical likelihood of benefit was higher in younger patients with less advanced HF and use of lipophilic statins.

C. albicans N-linked mannans potentiate the induction of trained immunity via Dectin-2

The interaction between the Candida albicans cell wall and pattern recognition receptors is crucial for the initiation of host immune responses which, ultimately, contribute to the clearance of this pathogenic fungus. In the present study, we investigate the ability of C. albicans mannans to modulate immune response and induce innate immune memory (also termed trained immunity). Using mutants of C. albicans that are defective in, or lack mannosyl residues, we show that alterations in the mannosylation of the C. albicans cell wall affect the innate cytokine response and strongly reduce the secretion of T cell-derived cytokines. Subsequently, we demonstrate that the branching of N-linked mannan, but not O-linked mannan, is essential to potentiate the induction of trained immunity, a process mediated by Dectin-2. In conclusion, N-linked mannan is needed, in addition to β-glucans, for an effective induction of trained immunity by C. albicans.

A CO2 sensing module modulates β-1,3-glucan exposure in Candida albicans

Microbial species capable of co-existing with healthy individuals, such as the commensal fungus Candida albicans, exploit multifarious strategies to evade our immune defenses. These strategies include the masking of immunoinflammatory pathogen-associated molecular patterns (PAMPs) at their cell surface. We reported previously that C. albicans actively reduces the exposure of the proinflammatory PAMP, β-1,3-glucan, at its cell surface in response to host-related signals such as lactate and hypoxia. Here, we show that clinical isolates of C. albicans display phenotypic variability with respect to their lactate- and hypoxia-induced β-1,3-glucan masking. We have exploited this variability to identify responsive and non-responsive clinical isolates. We then performed RNA sequencing on these isolates to reveal genes whose expression patterns suggested potential association with lactate- or hypoxia-induced β-1,3-glucan masking. The deletion of two such genes attenuated masking: PHO84 and NCE103. We examined NCE103-related signaling further because NCE103 has been shown previously to encode carbonic anhydrase, which promotes adenylyl cyclase-protein kinase A (PKA) signaling at low CO2 levels. We show that while CO2 does not trigger β-1,3-glucan masking in C. albicans, the Sch9-Rca1-Nce103 signaling module strongly influences β-1,3-glucan exposure in response to hypoxia and lactate. In addition to identifying a new regulatory module that controls PAMP exposure in C. albicans, our data imply that this module is important for PKA signaling in response to environmental inputs other than CO2.IMPORTANCEOur innate immune defenses have evolved to protect us against microbial infection in part via receptor-mediated detection of "pathogen-associated molecular patterns" (PAMPs) expressed by invading microbes, which then triggers their immune clearance. Despite this surveillance, many microbial species are able to colonize healthy, immune-competent individuals, without causing infection. To do so, these microbes must evade immunity. The commensal fungus Candida albicans exploits a variety of strategies to evade immunity, one of which involves reducing the exposure of a proinflammatory PAMP (β-1,3-glucan) at its cell surface. Most of the β-1,3-glucan is located in the inner layer of the C. albicans cell wall, hidden by an outer layer of mannan fibrils. Nevertheless, some β-1,3-glucan can become exposed at the fungal cell surface. However, in response to certain specific host signals, such as lactate or hypoxia, C. albicans activates an anticipatory protective response that decreases β-1,3-glucan exposure, thereby reducing the susceptibility of the fungus to impending innate immune attack. Here, we exploited the natural phenotypic variability of C. albicans clinical isolates to identify strains that do not display the response to β-1,3-glucan masking signals observed for the reference isolate, SC5314. Then, using genome-wide transcriptional profiling, we compared these non-responsive isolates with responsive controls to identify genes potentially involved in β-1,3-glucan masking. Mutational analysis of these genes revealed that a sensing module that was previously associated with CO2 sensing also modulates β-1,3-glucan exposure in response to hypoxia and lactate in this major fungal pathogen of humans.

The impact of ORF19.36.1 in the pathobiology of Candida albicans

BACKGROUND

Our previous proteomics data obtained from Candida albicans recovered after serial passage in a murine model of systemic infection revealed that Orf19.36.1 expression correlates with the virulence of the fungus. Therefore, the impact of ORF19.36.1 upon virulence was tested in this study.

MATERIALS & METHODS

CRISPR-Cas9 technology was used to construct homozygous C. albicans orf19.36.1 null mutants and the phenotypes of these mutants examined in vitro (filamentation, invasion, adhesion, biofilm formation, hydrolase activities) and in vivo assays.

RESULTS

The deletion of ORF19.36.1 did not significantly impact the phenotypes examined or the virulence of C. albicans in two infection models.

CONCLUSION

These results suggest that, although Orf19.36.1 expression correlates with virulence, this protein is not essential for C. albicans pathobiology.

A General Assessment of India's Extremely Low Number of Transgender Cancer Patients

PURPOSE/OBJECTIVE(S)

Physiological transgender (TJ) is one of the most marginalized and oppressed community in the Indian subcontinent. The observable percentage of physiological transgender (TJ) cancer patients is extremely low. This concise report aims to assess the factors that contribute to the scarcity of transgender cancer patients.

MATERIALS/METHODS

The hospital database (2012-2021) of 2 centers in New Delhi (population 32 million) & 1 in Kolkata (15 million) were evaluated. In addition, 28 senior oncologists (ONC) and 17 trans women (TWs) completed a six-point questionnaire. ONC was asked how many TJ patients they had seen in their career, as well as histopathology/site. Furthermore, the data was extrapolated to account for all clinicians' cumulative years of experience. The questions for TWs were age and where they go if you have a disease or illness. And, do they know any TJ cancer patients?

RESULTS

India's last census (2011) revealed a half-million TJ population. TJ density must be at least 1 million to be comparable to the rest of the world. Hospital databases counted 10,486 patients, with no patient identified as TJ. A total of 37 TJ cancer patients were reported by 28 ONC with an average and collective years of their medical service of 23.1±4.1 and 646 years; distributed in 3 metropolis of 67 million (combined) population (Kolkata, New Delhi, and Mumbai). The average lifetime number of TJ cancer patients/oncologist was 1.3±1.1. Total 12 cases were head neck cancers, with 4 caused by human papillomavirus. The remaining 25 patients have 5 lung, 5 gynecological, 4 breast, 3 brain cancers, 2 soft tissue sarcomas, and 6 cases of unknown origin. The density of 5-year prevalent cancer cases in India is 0.2%, with an estimated 0.007% of TJ cancer patients. TW could not identify any cancer patients in their community.

CONCLUSION

Being transgender is a social taboo in this part of the world. Their legal rights and classification as the third gender are uncommon. TJs are denied access to standard education, mainstream occupations, and social respect. Although the exact number has never been determined, it is estimated that a large proportion (≈90%) of TJ people are forced to choose roadside begging and working as cheap sex workers. There is no clinical reason why TJs should have fewer cancer incidents, they should be more susceptible to cancer due to unhealthy living conditions, unprotected sex, lack of medical care, proper nutrition, and all other factors associated with their very low socioeconomic status. Nonetheless, it's difficult to find single TJ cancer patients in both public and private hospital OPD. They may be unable to access a traditional clinic due to social discrimination, financial constraints, or they may be unwilling to disclose their true sex. Even TJ's do not show up at free public clinics. The disclosure of true sex may be beneficial in obtaining better treatment, but the more prevalent reason is social unacceptability, which can be overcome through proper education and community economic growth.

Glucose-enhanced oxidative stress resistance-A protective anticipatory response that enhances the fitness of Candida albicans during systemic infection

Most microbes have developed responses that protect them against stresses relevant to their niches. Some that inhabit reasonably predictable environments have evolved anticipatory responses that protect against impending stresses that are likely to be encountered in their niches-termed "adaptive prediction". Unlike yeasts such as Saccharomyces cerevisiae, Kluyveromyces lactis and Yarrowia lipolytica and other pathogenic Candida species we examined, the major fungal pathogen of humans, Candida albicans, activates an oxidative stress response following exposure to physiological glucose levels before an oxidative stress is even encountered. Why? Using competition assays with isogenic barcoded strains, we show that "glucose-enhanced oxidative stress resistance" phenotype enhances the fitness of C. albicans during neutrophil attack and during systemic infection in mice. This anticipatory response is dependent on glucose signalling rather than glucose metabolism. Our analysis of C. albicans signalling mutants reveals that the phenotype is not dependent on the sugar receptor repressor pathway, but is modulated by the glucose repression pathway and down-regulated by the cyclic AMP-protein kinase A pathway. Changes in catalase or glutathione levels do not correlate with the phenotype, but resistance to hydrogen peroxide is dependent on glucose-enhanced trehalose accumulation. The data suggest that the evolution of this anticipatory response has involved the recruitment of conserved signalling pathways and downstream cellular responses, and that this phenotype protects C. albicans from innate immune killing, thereby promoting the fitness of C. albicans in host niches.

Nature of β-1,3-Glucan-Exposing Features on Candida albicans Cell Wall and Their Modulation

Candida albicans exists as a commensal of mucosal surfaces and the gastrointestinal tract without causing pathology. However, this fungus is also a common cause of mucosal and systemic infections when antifungal immune defenses become compromised. The activation of antifungal host defenses depends on the recognition of fungal pathogen-associated molecular patterns (PAMPs), such as β-1,3-glucan. In C. albicans, most β-1,3-glucan is present in the inner cell wall, concealed by the outer mannan layer, but some β-1,3-glucan becomes exposed at the cell surface. In response to host signals, such as lactate, C. albicans induces the Xog1 exoglucanase, which shaves exposed β-1,3-glucan from the cell surface, thereby reducing phagocytic recognition. We show here that β-1,3-glucan is exposed at bud scars and punctate foci on the lateral wall of yeast cells, that this exposed β-1,3-glucan is targeted during phagocytic attack, and that lactate-induced masking reduces β-1,3-glucan exposure at bud scars and at punctate foci. β-1,3-Glucan masking depends upon protein kinase A (PKA) signaling. We reveal that inactivating PKA, or its conserved downstream effectors, Sin3 and Mig1/Mig2, affects the amounts of the Xog1 and Eng1 glucanases in the C. albicans secretome and modulates β-1,3-glucan exposure. Furthermore, perturbing PKA, Sin3, or Mig1/Mig2 attenuates the virulence of lactate-exposed C. albicans cells in Galleria. Taken together, the data are consistent with the idea that β-1,3-glucan masking contributes to Candida pathogenicity. IMPORTANCE Microbes that coexist with humans have evolved ways of avoiding or evading our immunological defenses. These include the masking by these microbes of their "pathogen-associated molecular patterns" (PAMPs), which are recognized as "foreign" and used to activate protective immunity. The commensal fungus Candida albicans masks the proinflammatory PAMP β-1,3-glucan, which is an essential component of its cell wall. Most of this β-1,3-glucan is hidden beneath an outer layer of the cell wall on these microbes, but some can become exposed at the fungal cell surface. Using high-resolution confocal microscopy, we examine the nature of the exposed β-1,3-glucan at C. albicans bud scars and at punctate foci on the lateral cell wall, and we show that these features are targeted by innate immune cells. We also reveal that downstream effectors of protein kinase A (Mig1/Mig2, Sin3) regulate the secretion of major glucanases, modulate the levels of β-1,3-glucan exposure, and influence the virulence of C. albicans in an invertebrate model of systemic infection. Our data support the view that β-1,3-glucan masking contributes to immune evasion and the virulence of a major fungal pathogen of humans.

Impact of changes at the Candida albicans cell surface upon immunogenicity and colonisation in the gastrointestinal tract

The immunogenicity of Candida albicans cells is influenced by changes in the exposure of microbe-associated molecular patterns (MAMPs) on the fungal cell surface. Previously, the degree of exposure on the C. albicans cell surface of the immunoinflammatory MAMP β-(1,3)-glucan was shown to correlate inversely with colonisation levels in the gastrointestinal (GI) tract. This is important because life-threatening systemic candidiasis in critically ill patients often arises from translocation of C. albicans strains present in the patient's GI tract. Therefore, using a murine model, we have examined the impact of gut-related factors upon β-glucan exposure and colonisation levels in the GI tract. The degree of β-glucan exposure was examined by imaging flow cytometry of C. albicans cells taken directly from GI compartments, and compared with colonisation levels. Fungal β-glucan exposure was lower in the cecum than the small intestine, and fungal burdens were correspondingly higher in the cecum. This inverse correlation did not hold for the large intestine. The gut fermentation acid, lactate, triggers β-glucan masking in vitro, leading to attenuated anti-Candida immune responses. Additional fermentation acids are present in the GI tract, including acetate, propionate, and butyrate. We show that these acids also influence β-glucan exposure on C. albicans cells in vitro and, like lactate, they influence β-glucan exposure via Gpr1/Gpa2-mediated signalling. Significantly, C. albicans gpr1Δ gpa2Δ cells displayed elevated β-glucan exposure in the large intestine and a corresponding decrease in fungal burden, consistent with the idea that Gpr1/Gpa2-mediated β-glucan masking influences colonisation of this GI compartment. Finally, extracts from the murine gut and culture supernatants from the mannan grazing gut anaerobe Bacteroides thetaiotaomicron promote β-glucan exposure at the C. albicans cell surface. Therefore, the local microbiota influences β-glucan exposure levels directly (via mannan grazing) and indirectly (via fermentation acids), whilst β-glucan masking appears to promote C. albicans colonisation of the murine large intestine.

Inflammation and risk of recurrent cardiovascular events according to prior vascular disease location

Background

In recent years, anti-inflammatory drugs have been shown to reduce the risk of recurrent cardiovascular disease (CVD) events in patients with coronary artery disease (CAD), but have not yet been tested in patients with other vascular disease locations. Whether the relation between inflammation and recurrent CVD is modified by prior vascular disease location is unknown.

Purpose

This study aimed to establish the relation between low-grade inflammation and recurrent CVD according to prior vascular disease location.

Methods

Inflammation was measured by plasma concentrations of high-sensitivity C-reactive protein (CRP). Patients from the UCC-SMART cohort with CAD (n=4,517), cerebrovascular disease (CeVD; n=2,154), peripheral artery disease (PAD, n=1,154), or abdominal aortic aneurysm (AAA, n=424), and CRP ≤10 mg/L were included in the main analysis (combined n=8,249). Patients with CRP >10 mg/L (n=756) were analysed separately. The primary outcome was a composite of myocardial infarction, ischemic stroke, or cardiovascular death. Secondary outcomes included the primary outcome components, major adverse limb events (MALE), and all-cause mortality. The relation between CRP and outcomes was assessed using Cox proportional hazard models stratified by prior vascular disease location, and adjusted for potential confounders.

Results

During a median follow-up of 9.5 years (interquartile range 5.1–13.9) 1,877 CVD events, 887 MALE events, and 2,341 deaths were observed. In the total population, CRP was related to recurrent CVD (hazard ratio [HR] per 1 mg/L 1.08; 95% confidence interval [CI] 1.05–1.10), and all secondary outcomes except for ischemic stroke (HR 1.03; 95% CI 0.99–1.08). Compared to the first quintile of CRP, HRs for recurrent CVD were 1.66 (95% CI 1.41–1.96) for the last quintile ≤10 mg/L, and 1.97 (95% CI 1.64–2.36) for the subgroup with CRP >10 mg/L. CRP was related to recurrent CVD in patients with CAD (HR per 1 mg/L 1.08; 95% CI 1.04–1.11), as well as CeVD (HR 1.05; 95% CI 1.01–1.10), PAD (HR 1.08; 95% CI 1.03–1.13), and AAA (HR 1.08; 95% CI 1.01–1.15; p for interaction 0.815). The relation between CRP and all-cause mortality was stronger for patients with CAD (HR 1.13; 95% CI 1.09–1.16) compared to other locations (HRs 1.06–1.08; p=0.002).

Conclusion

Inflammation is an independent risk factor of recurrent CVD and mortality, irrespective of prior vascular disease location. Trials of anti-inflammatory drugs in patients with CeVD, PAD, and AAA are warranted.

Funding Acknowledgement

Type of funding sources: None.

Refractive and Binocular Vision Status and Associated Asthenopia among Clinical Microscopists

Background Clinical microscopists are at a greater risk of developing binocular vision anomalies and asthenopia. Objective To assess the refractive and binocular vision status and to explore the association between the presence of asthenopic symptoms and microscopy work among clinical microscopists working at medical laboratory department. Method This cross-sectional study involved 37 clinical microscopists working at medical laboratory department of Dhulikhel Hospital, Nepal. The study was conducted from January to December 2013. Only those participants who had been using microscope for at least a year were enrolled in this study. Each participant underwent distance visual acuity (VA) assessment, refractions, and orthoptic evaluation, including measurement of distance and near phoria, near point of convergence (NPC), near point of accommodation (NPA), positive fusional vergence (PFV), adduction, and calculation of accommodation convergence/accommodation (AC/A) ratio. The tear test was also carried out in each subject. Information about use of glasses, microscopy work (duration, and time spent per day in microscope), and visual symptoms associated with the use of microscope such as eye strain, headache, double vision, and near vision were collected. Result The mean age of the clinical microscopists was 29 ± 5.7 years. The prevalence of refractive error was 56.76% and the mean spherical equivalent (SE) refractive error was -0.77 ± 0.86 D. Refractive error had neither correlation with microscopy work and asthenopic symptoms associated with it, and nor with binocular vision parametersNPC, AA and AC/A ratio. However, there was a positive association between asthenopic symptoms and microscopy work. There was statistically significant difference between symptomatic and asymptomatic subjects for binocular vision parameters, including NPC, AA and positive fusional vergence (PFV) for near. Conclusion Microscopy work has an impact on near binocular vision. Asthenopic symptoms bear a positive association with microscopy work. Refractive error has no significant correlation with either microscopy works or associated asthenopic symptoms.

S9.4c Diverse environmental inputs mediate changes in β-glucan exposure at the Candida albicans cell surface thereby influencing tissue colonisation during systemic infection

S9.4 Free oral presentations (late breaking), September 23, 2022, 4:45 PM - 6:15 PM

 

 

Candida albicans adaptation to host niches affects the exposure of key pathogen-associated molecular patterns (PAMPs) on its cell surface and, consequently, the detection of C. albicans cells by the immune system. Focusing on β-(1,3)-glucan, we screened for host inputs that influence the exposure of this immune-stimulatory PAMP on the C. albicans cell surface. We used a combination of fluorescent microscopy, flow cytometry, and cytokine assays, and then analyzed certain conditions in more detail using transmission electron microscopy and time-lapse video microscopy of C. albicans-phagocyte interactions. We found that some nutrients, micronutrient limitation, stresses, and antifungal drugs trigger β-glucan masking, whereas other inputs, such as nitrogen sources and quorum sensing molecules, exert limited effects on β-glucan exposure. In particular, host- or bacterial-derived L-lactate, hypoxia, or iron limitation induce β-glucan masking, and this leads to attenuation of phagocytic responses [Nature Micro 2, 16 238; mBio 9, e01318-18; Nature Comms 10, 5315]. Lactate signals through Gpr1 to activate Crz1 in a calcineurin-independent manner, whereas hypoxia signals via mitochondrial ROS, and iron limitation signals through Ftr1 and Sef1. β-glucan masking also depends upon downstream signaling via the cAMP-PKA pathway. We conclude that C. albicans has evolved to exploit a range of specific host-derived signals to modulate the exposure of a major PAMP at its cell surface in an attempt to evade phagocytic uptake. Using barcode-sequencing in direct competition assays in vivo, we showed that preadaptation to specific β-glucan masking signals affects the ability of this fungus to colonize particular tissues during systemic infection in a murine model. This reinforces the view that β-glucan masking promotes C. albicans infection.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Comparison of Hearing Result and Graft Uptake Rate between Temporalis Fascia and Tragal Cartilage in Endoscopic Myringoplasty

Background There are different methods to repair the perforation of the tympanic membrane. Recently cartilage has been used for the repair and results are comparable to temporalis fascia. For surgical procedure endoscope had added good assistance in middle ear surgery. Though the one hand technique the image quality and results are on par with the use of a microscope. Objective To compare the graft uptake rate and hearing results between temporalis fascia and tragal cartilage in endoscopic myringoplasty. Method This is a prospective, longitudinal study conducted among 50 patients who underwent endoscopic myringoplasty using temporalis fascia and tragal cartilage with 25 patients in each group. The hearing was assessed by comparing pre with post-operative ABG (Air bone gap) and ABG closure in speech frequencies (500Hz, 1 KHz, 2 KHz, 4 KHz). The status of graft and hearing results was evaluated on 6 months of follow up in both the groups. Result Out of total 25 patients enrolled for study in both (temporalis fascia and cartilage) groups, 23 (92%) patients in each group had graft uptaken. The audiological gain in the temporalis fascia group was 11.37±0.32 dB whereas in the tragal cartilage group it was 14.56±1.22dB. The audiological gain between the two groups did not show any statistically significant (p = 0.765). However, the pre and post-operative hearing difference was statistically significant in both temporalis fascia and tragal cartilage group. Conclusion Tragal cartilage has similar graft uptake rate and hearing gain when compared with temporalis fascia in endoscopic myringoplasty. Hence, tragal cartilage can be used for myringoplasty whenever required without any fear of deterioration in hearing.

Ischemic and Bleeding Profile of Patients on Dual Antiplatelet Therapy beyond 1 Year of Index Acute Coronary Syndrome / Percutaneous Intervention

Dual antiplatelet treatment (DAPT) is the cornerstone of the management and prophylaxis of acute coronary syndrome (ACS). However, the associated risk of bleeding with the usage of DAPT and risk of thrombosis with stoppage of the drug makes it a challenging task to take appropriate decisions regarding the choice and duration of DAPT. The present study is aimed to tackle these challenges and to analyze whether prolonged dual antiplatelet therapy carries more risk of bleeding or a higher risk of thrombosis is present with discontinuation of the same.

MATERIAL

In this study, a total of 235 cases of confirmed myocardial infarction, unstable angina, or those who underwent percutaneous intervention were included. After 1 year, the number of patients on DAPT, the type of antiplatelets they were using were observed, their ischemic risk was calculated using DAPT score, and bleeding risk was calculated using PRECISE-DAPT score. Bleeding events were assessed using BARC classification.

OBSERVATION

Out of 235 patients, the majority of the patients were males (78.7%). Only 7.2% of the patients had bleeding since the start of the drugs. The majority (5% out of 7.2%) of bleeding episodes were clinically insignificant. 163 (69%) patients were on Dual antiplatelet therapy after 1 year. Out of which 115 were appropriately taking DAPT as per their DAPT score. Patients with high bleeding risk (PRECISE DAPT score ≥25) were 89, out of which 38 (53.2%) patients were taking SAPT, appropriate for their bleeding risk. While 112 (68.7%) were taking prolonged DAPT, appropriate for PRECISE-DAPT risk.

CONCLUSION

The majority of patients remained on DAPT following discharge for more than 1 year after ACS. This suggests that treating physicians prioritizes ischemic risk reduction over bleeding risk in patients with ACS, according to the patient's risk profile.

Instantaneous wave-free ratio and fractional flow reserve: effect of variation in left ventricular end diastolic pressure

Funding Acknowledgements

Type of funding sources: None.

Introduction

Among patients with intermediate coronary artery stenosis (50-90%), assessment of functional significance of the lesion by instantaneous wave free ratio (iFR)/ fractional flow reserve (FFR) is recommended in latest guidelines. Though iFR is not much affected by change in hemodynamics compared to FFR, the change in iFR vs FFR due to various hemodynamic factors need a validation. Left ventricular end-diastolic pressure (LVEDP) is one of the hemodynamic factors whose variation and effect on FFR vs iFR is largely unknown. In the present study we evaluated the association of change in LVEDP on the changing pattern of iFR/FFR which may hold a clinical significance especially with percutaneous coronary intervention in heart failure patients.

Methods

This was a prospective, investigator-initiated, single-center study involving 20 patients with stable coronary artery disease and at least one intermediate coronary lesion (50-90%). The enrolled patients were subjected to both iFR and FFR along with baseline LVEDP measurement. Subsequently, intravenous nitroglycerine infusion was given to reduce LVEDP and corresponding iFR and FFR were re-evaluated. The dynamic changes in iFR and FFR were studied in relation to changes in LVEDP using Pearson’s correlation analysis and linear regression analysis.

Results

The mean LVEDP was lowered from 16.20 ± 1.54 mmHg to 9.50 ± 1.10 mmHg, the mean iFR and FFR got changed from 0.80 ± 0.12 to 0.76 ± 0.12 mmHg and 0.75 ± 0.09 to 0.72 ± 0.09 mmHg respectively. On Pearson’s correlation analysis, LVEDP change did not show statistically significant correlation (linear relationship) with iFR (p = 0.105, r2 = 0.373) and FFR (p = 0.227, r2 = 0.283) changes across the entire range of stenosis severity and in all vessels. Linear regression analysis did not state any independent correlation between LVEDP and iFR and FFR changes in the study group (p >0.05). The % R2 value for iFR and FFR (as a coefficient of determination) of the regression equation were 13.9% and 8%, which means only these percentages of the total variance in iFR and FFR change were explained by LVEDP changes respectively. There was no serious adverse event related to the procedure.

Conclusion

To the best of our knowledge, this is the first study comparing the effect of changes in LVEDP on both iFR and FFR simultaneously. In our study, 1 mmHg change in LVEDP was associated with a change in FFR by 0.004 and change in iFR by 0.004 which didn’t reveal any significant association (p = 0.227 and 0.105 respectively). This helps us to put FFR at par with iFR under variable hemodynamics.  So either of the variables may be used interchangeably with confidence in varied hemodynamic conditions including patients with heart failure. The correlation was non-significant across entire range of stenosis severity, irrespective of sex, age, diabetes and hypertension. This study sets platform for further research with larger number of heterogeneous patient population. Abstract Figure. Box whisker plot

Role of oral flecainide in assessement of atrio-ventricular conduction in symptomatic bifascicular block

Background

Intravenous flecainide is used to stress Atrio-ventricular (AV) conduction in patients (pts) with a history of syncope & bifascicular (Bi-Fasc) block. Role of oral flecainide is unclear.

Objective

To assess effect of oral Flecainide on infra-Hisian AV conduction in patients with symptomatic Bi-Fasc block.

Methods

Pts presenting with syncope & Bi-Fasc block without advanced AVCD on ECG, 24 hr holter or treadmill exercise test were taken. Those with history suggestive of reflex syncope & positive tilt test were excluded. Remaining underwent electro-physiological (EP) study. Pts with HV interval >100ms or intra/infra-Hisian block at rest or incremental pacing were subjected to PPI. Remaining received oral Flacanide 5 mg/kg (max 300 mg) & EP study was repeated after ½ hr, 1 hr, 2 hrs and 3 hrs. Primary end-point was HV ≥100ms or infra/intra-Hisian type IIB or III block.

Results

Of 41 pts enrolled for study, 28 patients (mean age 60.0 yrs, mean LVEF 60.7%) were eligible for EP Study. Basal PR interval was 185.8±47.4 ms & mean QRS width was 130.6±18.65 ms. On EP study, 4 (14.3%) with resting HV >100 ms & 6 (21.4%) with HV >100 ms on incremental pacing underwent PPI.

Out of remaining 18 pts who were given flecainide, 11 (66.1%) achieved primary endpoint (HV >100 ms in 6, infra-hisian IIB in 2 and 2:1 block in 3 patients). At mean follow up of 6.5 months, 13 (59.1%) out of 22 with PPI had mean 59.1% VP & none of 6 remaining patients had any symptom.

Conclusion

Oral Flecainide significantly increases the diagnostic yield of EP study in patients with symptomatic bi-fasc block.

Funding Acknowledgement

Type of funding sources: None.

Comparison of traditional versus artificial intelligence based coronary artery disease risk prediction scores in young patients with acute coronary syndrome

Background

Ever since the concept of preventive cardiology has come into vogue, several risk identification models have come up which combine several risk factors to create a risk prediction score for occurrence of cardiovascular (CV) event. While carrying a proven validation in Western population, none of the risk prediction model has been satisfactorily evaluated in Indians especially young <40 years old.

Objectives

To compare Artificial Intelligence based novel risk score with traditional risk scores in young (less than 40 years age) patients presenting with acute coronary syndrome (ACS) and to estimate the relative efficacy of different coronary artery disease (CAD) risk scores in young Indian Patients.

Design

Single center, Observational, Non-interventional study.

Participants

Cohort of Patients more than 20 but less than 40 years old with ACS in the department of Cardiology from 1st January 2019 to 31st October 2019.

Methods

314 young patients [mean age 36.14±4.17 years] presenting with acute coronary syndrome (ACS) were enrolled. The three clinically most pertinent risk assessment models [Framingham Risk score (FRS), World Health Organization risk prediction charts (WHO/ISH), and QRISK3 scores] and Artificial Intelligence based novel risk score (AICVD) were applied on day 1 of presentation, and tried to see whether one risk score versus other risk score could have predicted the event earlier had we applied it before the occurrence of ACS. Risk factors considered included those already in traditional scoring systems and new risk factors (diet, alcohol, tobacco, dyslipidemia, physical activity, family history of heart disease, history of heart disease, heart rate, respiratory rate, chronic heart symptoms and psychological stress).

Results

WHO/ISH provided the lowest high risk estimate with only 1 (0.9%) patient estimated to be having >20% 10-year risk. The FRS estimated high risk (>20% 10-year risk) in 3 (1%) patients. The QRISK3 estimated high risk (>10% 10-year risk) in 20 (6.5%) patient. In comparison, AICVD risk prediction model stood tall by identifying 73 (23.2%) patients as high risk and 62.74% patients as more than moderate risk for having CV events at 7 years (p<0.001).

Conclusion

Perhaps, this is the first study which has compared artificial intelligence based novel risk prediction model with the three most commonly applied models, in the young Indian patients. We found that a cohort of young Indian patients presenting with ACS, when studied retrospectively, was identified as “high risk” most likely by AICVD risk prediction model rather than the traditional counterparts. The WHO/ISH risk prediction charts and FRS were the poorest predictors. Performance of QRISK3 score also remained less than satisfactory. These findings suggested that AICVD risk prediction model is a promising tool to assess for CV risk in Indian population.

Funding Acknowledgement

Type of funding sources: None. Predictability of risk prediction models

Anticipatory Stress Responses and Immune Evasion in Fungal Pathogens

In certain niches, microbes encounter environmental challenges that are temporally linked. In such cases, microbial fitness is enhanced by the evolution of anticipatory responses where the initial challenge simultaneously activates pre-emptive protection against the second impending challenge. The accumulation of anticipatory responses in domesticated yeasts, which have been termed 'adaptive prediction', has led to the emergence of 'core stress responses' that provide stress cross-protection. Protective anticipatory responses also seem to be common in fungal pathogens of humans. These responses reflect the selective pressures that these fungi have faced relatively recently in their evolutionary history. Consequently, some pathogens have evolved 'core environmental responses' which exploit host signals to trigger immune evasion strategies that protect them against imminent immune attack.

Immune cells fold and damage fungal hyphae

Innate immunity provides essential protection against life-threatening fungal infections. However, the outcomes of individual skirmishes between immune cells and fungal pathogens are not a foregone conclusion because some pathogens have evolved mechanisms to evade phagocytic recognition, engulfment, and killing. For example, Candida albicans can escape phagocytosis by activating cellular morphogenesis to form lengthy hyphae that are challenging to engulf. Through live imaging of C. albicans-macrophage interactions, we discovered that macrophages can counteract this by folding fungal hyphae. The folding of fungal hyphae is promoted by Dectin-1, β2-integrin, VASP, actin-myosin polymerization, and cell motility. Folding facilitates the complete engulfment of long hyphae in some cases and it inhibits hyphal growth, presumably tipping the balance toward successful fungal clearance.

Mitochondrial Reactive Oxygen Species Regulate Immune Responses of Macrophages to Aspergillus fumigatus

Reactive Oxygen Species (ROS) are highly reactive molecules that can induce oxidative stress. For instance, the oxidative burst of immune cells is well known for its ability to inhibit the growth of invading pathogens. However, ROS also mediate redox signalling, which is important for the regulation of antimicrobial immunity. Here, we report a crucial role of mitochondrial ROS (mitoROS) in antifungal responses of macrophages. We show that mitoROS production rises in murine macrophages exposed to swollen conidia of the fungal pathogen Aspergillus fumigatus compared to untreated macrophages, or those treated with resting conidia. Furthermore, the exposure of macrophages to swollen conidia increases the activity of complex II of the respiratory chain and raises mitochondrial membrane potential. These alterations in mitochondria of infected macrophages suggest that mitoROS are produced via reverse electron transport (RET). Significantly, preventing mitoROS generation via RET by treatment with rotenone, or a suppressor of site IQ electron leak, S1QEL1.1, lowers the production of pro-inflammatory cytokines TNF-α and IL-1β in macrophages exposed to swollen conidia of A. fumigatus. Rotenone and S1QEL1.1 also reduces the fungicidal activity of macrophages against swollen conidia. Moreover, we have established that elevated recruitment of NADPH oxidase 2 (NOX2, also called gp91phox) to the phagosomal membrane occurs prior to the increase in mitoROS generation. Using macrophages from gp91phox-/- mice, we have further demonstrated that NOX2 is required to regulate cytokine secretion by RET-associated mitoROS in response to infection with swollen conidia. Taken together, these observations demonstrate the importance of RET-mediated mitoROS production in macrophages infected with A. fumigatus.

Knowledge and Attitude on Eye Donation among Undergraduate Medical Students of Kathmandu University School of Medical Sciences, Nepal

Background Corneal blindness accounts for a significant proportion of avoidable visual impairment in developing countries. Eye donation is voluntary and awareness in undergraduate medical students being a future practitioner in any field are expected to be linked to patients during death in hospitals. Objective To assess the awareness of medical students on eye donation at Kathmandu University School of Medical Sciences (KUSMS). Method This was a cross-sectional study conducted among undergraduate medical students of KUSMS. Students' responses were recorded using a predesigned, pretested, semistructured questionnaire inquiring knowledge and attitude of eye donation, sources of information, their willingness to donate eyes as well as the reasons for donating/ not donating eyes. Result Less than half of the medical students (45.6%) were aware of eye donation only after death. Newspapers (72.2%) were the major source of information. The final year medical students were more aware (Average knowledge score = 11.56 ± 2.05) than their juniors. 80.7% of the students were willing to donate their eyes. The adjudged reasons for willingness to donate were that eye donation is a noble work and pleasure in helping a blind person while the reasons for unwillingness to donate were lack of awareness followed by family objection to eye donation. Conclusion Future medical practitioners possessed satisfactory knowledge about eye donation. Educating this cadre of human resources to sensitize them towards the need for eye donation would be a crucial step towards reducing the global burden of corneal blindness.

Robust Simultaneous and Proportional Myoelectric Control Scheme for Individuals with Transradial Amputations

Commercial myoelectric prostheses need to be accurate and clinically viable to be successful. This study proposed a simultaneous and proportional control scheme with frequency division technique (SPEC-FDT) to address limitations in current myoelectric prosthesis control, specifically to address non-stationaries such as contraction level variations and unintended activations. Twenty able-bodied participants (14 males and 6 females, age 23.4 ± 3.0) and four individuals with transradial amputations performed wrist movements (flexion/extension, rotations and combined movements) in two degrees-of freedom virtual tasks. The SPEC-FDT had a completion rate (CR)>90% for both control and clinical participants which was significantly higher than the conventional technique (CR=68%). Our results showed that SPEC-FDT is highly accurate for both able-bodied and clinical participants and provides a robust myoelectric control scheme allowing for increased prosthetic hand functions.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Prevalence, Extent, and Severity of Oral Health Impacts Among Adults in Rural Karnataka, India

INTRODUCTION

Oral health affects quality of life. Many studies have investigated the factors associated with oral health-related quality of life (OHRQoL). Little is known about OHRQoL of adults living in rural and remote areas of India, where many have lower levels of education and limited availability of oral health care services.

OBJECTIVES

To determine the prevalence, extent, and severity of OHRQoL impacts associated with psychosocial factors, functional dentition, and patterns of dental visits among rural Indian adults between the ages of 35 and 54 y.

METHODS

A cross-sectional study was conducted with a multistage stratified sampling strategy targeting 35- to 54-year-olds. Interviews and oral examinations were performed to collect data on sociodemographic variables, Oral Health Impact Profile-14 (OHIP-14), patterns of dental visits, stress, tobacco and alcohol use, and dentition status. Univariate, bivariate, and multivariable analyses were done to determine the factors associated with prevalence, extent, and severity of OHIP-14 using SAS version 9.3.

RESULTS

There were 873 participants. Prevalence, extent, and severity of OHIP-14 were 13.4%, 0.5 (0.4-0.7), and 11.8 (11.2-12.5), respectively. The OHIP-14 impacts reported were not severe and mostly affected physical functioning. Levels of education, income, and number of functional teeth (FT) were inversely associated and last dental visit within the previous year was positively associated with prevalence, extent, and severity of OHIP-14. The prevalence of 1 or more oral health impacts was nearly 13% among rural middle-aged adults in India.

CONCLUSIONS

Low socioeconomic conditions, dental visits, and FT ≤19 were positively associated with prevalence, extent, and severity of oral health impacts.

KNOWLEDGE TRANSFER STATEMENT

This article provides data regarding OHRQoL of people in rural areas of a developing country. The study was intended to determine the factors associated with OHRQoL in rural people who are less educated and living in areas with minimal oral health care facilities. The findings of this study could potentially facilitate further research and health promotional activities for rural people of developing countries.

Universal Neonatal Hearing Screening: An Experience at Tertiary Care Hospital

Background Hearing loss among neonates is one of the important health issue in pediatric population which may remain unnoticed until the child reaches a certain age. The importance of universal early screening, diagnosis and intervention in reducing the negative impact of congenital hearing loss has been described all over the world. Objective To observe the outcome of hearing screening by Automated Auditory Brainstem Response (AABR) in newborns delivered in Dhulikhel Hospital and neonates admitted in an intensive care unit (NICU) of Dhulikhel Hospital. Method A prospective study was done in neonates who were born at Dhulikhel Hospital, Kathmandu University Hospital from February 15th, 2017 to October 30th, 2019. AABR was used for their hearing assessment within 24 hours of birth and again at about 6 weeks of age in those neonates who failed the initial test. All the neonates admitted in NICU were studied regarding the risk factors based on Joint committee on Infant Hearing. Those who failed the test for the second time were referred for detailed audiological diagnostic work up. Result The screening rate was 92.6% of the total deliveries. A total of 5517 neonates comprising of 2800 males and 2717 females were screened from total deliveries of 5956 neonates in the study period. Among them, NICU (sick) babies were 422 (7.7%) and well babies were 5095 (92.3%). Out of them, 1675 failed the test in the first screening and 374 failed in the second screening. So, the total number of referred babies in second screening was 6.7% (374) out of 5517 screened. Amongst them, well babies were 6.59% (336), out of 5095 screened and sick babies were 9% (38) out of 422 screened. Low birth weight and prematurity were found to be the commonest risk factor present among them, followed by the use of ototoxic medications, hyperbilirubinemia and prolonged use of mechanical ventilation. Conclusion Automated Auditory Brainstem Response (AABR) is a very useful tool for hearing screening which should preferably be done in all the neonates where possible. It should be done within one month of life and those with confirmed hearing loss should receive early appropriate intervention for better hearing in future.

Thoughts on the evolution of Core Environmental Responses in yeasts

The model yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe, display Core Environmental Responses (CERs) that include the induction of a core set of stress genes in response to diverse environmental stresses. CERs underlie the phenomenon of stress cross-protection, whereby exposure to one type of stress can provide protection against subsequent exposure to a second type of stress. CERs have probably arisen through the accumulation, over evolutionary time, of protective anticipatory responses (“adaptive prediction”). CERs have been observed in other evolutionarily divergent fungi but, interestingly, not in the pathogenic yeast, Candida albicans. We argue that this is because we have not looked in the right place. In response to specific host inputs, C. albicans does activate anticipatory responses that protect it against impending attack from the immune system. Therefore, we suggest that C. albicans has evolved a CER that reflects the environmental challenges it faces in host niches.

•

We review Core Environmental Responses (CERs) in domesticated and pathogenic yeasts.

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CERs probably evolved through the accumulation of protective anticipatory responses.

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Evolutionarily diverse yeasts display CERs, but the pathogen, Candida albicans, does not.

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C. albicans has evolved an alternative CER that protects against immune clearance.

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This has implications for the investigation of CERs in other fungi.

4300Strain parameters at rest and after exercise in symptomatically stable patients with improved heart failure - STRESS-HF

Background

Optimal medical therapy (OMT) results in improvement in left ventricular (LV) ejection fraction (EF) and reduction in LV size in approximately 40% of patients of heart failure with reduced ejection fraction (HFrEF). Recent studies have proposed to continue treatment in all patients of this subgroup as improvement in LVEF does not indicate actual myocardial recovery. Global Longitudinal strain (GLS) is more sensitive marker of LV systolic function and better predictor of mortality than LVEF. GLS may identify probable patients in whom the therapy can be minimized or stopped.

Aim

To determine global longitudinal strain at rest and after exercise in patients with idiopathic dilated cardiomyopathy (DCM) who have improved LVEF ≥50% on guideline directed medical therapy (GDMT) and compare with resting & exercising LVEF on 3-dimesional (3D).

Material and methods

This Observational study was conducted in a tertiary care referral hospital, from February 2018 to October 2018. All patients with idiopathic DCM who had a documented LVEF of ≤40% in the past and improved LVEF (LVEF ≥50%) on GDMT were included in the study. Patients with secondary causes of HFrEF, poor echocardiographic window and inability to exercise were excluded from the study. Strain parameters were calculated at rest and after atleast 5 METS of exercise. GLS value of ≥ minus 12.6% was considered as mildly reduced strain, ≤ minus 8% as severely reduced strain and the values in between as moderately reduced strain. Post exercise, drop of >5% in absolute LVEF value or decrease in GLS >15% from baseline was considered as poor myocardial recovery.

Results

A total of 44 patients [mean age of 46.8±13.1 years and 24 males (54.5%)] constituted the study group. At the time of diagnosis, 31 (70.5%) patients were in NYHA class II and the remaining were in class III. Duration of GDMT ranged from 4 to 38 (median 12) months. Following improvement on GDMT, 25 (56.8%) were in class I and rest were in class II. Mean LVEF at diagnosis and after recovery was 33.6±4.9% and 55.1±4.5%, respectively with a mean absolute change in LVEF of 21.3±6.1%. At rest, mean 3D LVEF was 53±3.5% and GLS was −12.3±3.1. Mild, moderate and severely reduced strain was seen in 24 (54.5%), 13 (29.6%) and 7 (15.9%), respectively. After exercise, mean 3D LVEF was 51.5.±4.5% (mean decrease 1.5±2.1%) and mean GLS was −7±4.2% (mean decrease −5.3±4.6%). After exercise, none had a fall of LVEF >5% however 32 (72.7%) had a decrease of >15% in GLS. Seven (15.9%) patients had improvement in GLS, 4 (9.1%) had <15% decrease and 1 (2.3%) showed no change in GLS on exercise. The change in GLS on exercise was significant (p=0.001), but change in 3D LVEF was not significant (p=0.956).

Conclusion

Global longitudinal strain is a better marker for assessing myocardial recovery than LVEF in patients of heart failure with improved ejection fraction.

Acknowledgement/Funding

None

Factors Affecting Recanalisation after Optimal Management of Deep Vein Thrombosis; A single institution based study

Background Presence of recanalisation will favour for better physiological recovery after medical management of Deep Vein Thrombosis (DVT) along with lesser chances of post thrombotic syndrome. Rate of recanalisation is varied and can range from 43-57% and the factors that affect recanalisation are still a dilemma. Objective To know the factors for recanalisation following Deep Vein Thrombosis. Method This is a single institution based retrospective-prospective analytical study encompassing all ultrasonologically diagnosed cases of Deep Vein Thrombosis in adults from January 2015 to November 2017. All the cases were admitted with oral warfarin bridged by Heparin/ Enoxaparin and were discharged once International Normalization Ratio was in therapeutic range. The patients were followed up for three months with minimal of three outpatient followup. Best finding in the doppler ultrasonography (done by Acuson P500, Seimens) in relation to recanalisation was taken for the study. Result There were 67 cases of Deep Vein Thrombosis. Of these cases male to female ratio was 0.91. The mean age was 48.07. Most common extent was up to common femoral vein (47.8%) followed by upto popliteal vein (40.3%). Remaining 11.9% had extension upto iliac veins. There was no recanalisation in 2 cases (3%). Partial recanalisation was seen in 23 cases (34.3%) while complete recanalisation was seen in 42 cases (62.7%). Recanalisation is more in DVT involving popliteal vein while it decreases as the extension goes up. In contrast to 79.4% complete recanalisation in popliteal vein, that in common femoral vein is 62.5% while in iliac vein is only 37.5%. Mean age in no recanalisation group is much younger than partial or complete recanalisation groups. Conclusion Recanalisation following Deep Vein Thrombosis distal to popliteal vein is more than that in proximal Deep Vein Thrombosis. The information on recanalization can be considered to use to decide upon the duration of medical management of Deep Vein Thrombosis.

Impact of the Environment upon the Candida albicans Cell Wall and Resultant Effects upon Immune Surveillance

The fungal cell wall is an essential organelle that maintains cellular morphology and protects the fungus from environmental insults. For fungal pathogens such as Candida albicans, it provides a degree of protection against attack by host immune defences. However, the cell wall also presents key epitopes that trigger host immunity and attractive targets for antifungal drugs. Rather than being a rigid shield, it has become clear that the fungal cell wall is an elastic organelle that permits rapid changes in cell volume and the transit of large liposomal particles such as extracellular vesicles. The fungal cell wall is also flexible in that it adapts to local environmental inputs, thereby enhancing the fitness of the fungus in these microenvironments. Recent evidence indicates that this cell wall adaptation affects host-fungus interactions by altering the exposure of major cell wall epitopes that are recognised by innate immune cells. Therefore, we discuss the impact of environmental adaptation upon fungal cell wall structure, and how this affects immune recognition, focussing on C. albicans and drawing parallels with other fungal pathogens.

Does a facilitated pathway improve access to dental services for homeless and disadvantaged adults?

Access to dental care is poorer for people experiencing homelessness and disadvantage due to barriers such as lengthy waiting lists, lack of transport, lack of information and fear of authorities and treatment. This study aimed to evaluate a system integration model for oral health care for clients of homeless services in Brisbane, Australia. This model aimed to provide a facilitated access pathway between homeless community organisations and a public dental service to improve access to dental care. Participants were adult (≥18 years) clients Brisbane homeless community organisations. Those who participated in the intervention evaluation completed a questionnaire, had their oral health screened and followed up for feedback at their dental appointment. Seventy-six clients of community organisations in Brisbane participated in the intervention and its evaluation. Fear was a barrier to accessing dental services for 23% (n = 18). Attendance to the subsequent appointments at the public dental clinic was high, with 85% (n = 64) attending their first appointment. A higher proportion of participants who had surgical and prosthodontic treatment needs at the screening did not attend their appointment compared to those with other needs. Overall the model piloted in this study had positive outcomes; with high attendance rates to the dental facility and positive experiences by participants.

Pattern and Prevalence of Refractive Error and Secondary Visual Impairment in Patients Attending a Tertiary Hospital in Dhulikhel, Nepal

Background Uncorrected refractive error is one of the most important causes of visual impairment worldwide. Objective To ascertain the pattern and prevalence of refractive error and secondary visual impairment in subjects attending Ophthalmology department. Method A prospective hospital-based study was designed where presenting visual acuity, age of presentation, refractive status, best corrected visual acuity and status of visual impairment were assessed in participants, ages ranging from 3-39 years presenting to the Ophthalmology department of Dhulikhel Hospital, Kathmandu University Hospital. History of use of spectacle was noted and participants were categorized into different visual impairment categories as per their presenting visual acuity. Result Out of a total of 4500 total clients examined during the study period, 388 (8.62%) had refractive error where 219 (56.44%) were females and 169 (43.56%) were males. Mean age at presentation was 22.70±7.69 years (range, 3-39 years). Astigmatism was the most common subtype seen in 373 eyes (48.06%), followed by myopia (366 eyes, 47.16%) and hypermetropia (31 eyes, 4.0%). Only 40.50% subjects who required refractive correction were using spectacle. 62.37% (242 clients) had some of visual impairment during their presentation. There was statistically significant improvement in visual acuity after refractive correction (p=0.00). Conclusion Uncorrected refractive error is one of the most important causes of visual impairment. Lack of awareness, infrequent ocular examination and lack of community or preschool vision screening were the main causes for the late presentation and significant visual impairment associated with the condition. Social stigma, economical limitation and negative counseling and attitudes about spectacle wear were primary factors behind the unsatisfactory spectacle use.

Sonographic Assessment of the Normal Dimensions of Liver, Spleen, and Kidney in Healthy Children at Tertiary Care Hospital

Background Ultrasonography is one of the most common imaging modality to measure dimensions of visceral organs in children. However, the normal limit of size of visceral organs according to age and body habitus has not been specified in the standard textbooks. This might result in under detection of organomegaly in pediatrics population. Objective The objective of this study was to determine the normal range of dimensions for the liver, spleen, and kidney in healthy children. Method This is prospective cross-sectional, hospital-based study done at Tertiary-care teaching hospital. Participants included 272 pediatric subjects (152 male and 120 female) with normal physical or sonographic findings who were examined because of problems unrelated to the measured organs. The subjects were one month to 15 year (180 months) old. All measured organs were sonographically normal. Relationships of the dimensions of these organs with sex, age, body weight and height were investigated. Limits of normal dimensions of these organs were defined. Result Normal length of liver, kidneys and spleen were obtained sonographically for 272 children (152 male [55.9%] and 120 female [44.1%]) in the age group from 1 months to 15 (180 months) years. The mean age was 45.78 months (SD, 44.73). The measured dimensions of all these organs showed highest correlation with height and age so the descriptive analysis of the organ dimensions (mean, minimum, and maximum values, SD and 5th and 95th percentiles) were expressed in 10 age groups along with height range of the included children. The mean length of right kidney was shorter than the left kidney length, and the difference was statistically significant (p = 0.001). Conclusion This study provides practical and comprehensive guide to the normal visceral organ dimension in pediatric population. The normal range limit of the liver, spleen, and kidney determined in this study could be used as a reference in daily practice in local radiology clinics.

Oral health impacts of medications used to treat mental illness

BACKGROUND

Many psychotropic medications affect oral health. This review identified oral side effects for antidepressant, antipsychotic, anticonvulsant, antianxiety and sedative drugs that are recommended in Australia for the management of common mental illnesses and provides recommendations to manage these side-effects.

METHODS

The Australian Therapeutic Guidelines and the Australian Medicines Handbook were searched for medications used to treat common mental health conditions. For each medication, the generic name, class, and drug company reported side-effects were extracted from the online Monthly Index of Medical Specialties (eMIMs) and UpToDate databases. Meyler's Side Effect of Drugs Encyclopaedia was used to identify additional oral adverse reactions to these medications.

RESULTS

Fifty-seven drugs were identified: 23 antidepressants, 22 antipsychotics or mood stabilisers, and 12 anxiolytic or sedative medications. Xerostomia (91%) the most commonly reported side effect among all classes of medications of the 28 identified symptoms. Other commonly reported adverse effects included dysguesia (65%) for antidepressants, and tardive dyskinesia (94%) or increased salivation (78%) for antipsychotic medications.

CONCLUSIONS

While xerostomia has often been reported as a common adverse effect of psychotropic drugs, this review has identified additional side effects including dysguesia from antidepressants and tardive dyskinesia and increased salivation from antipsychotics. Clinicians should consider oral consequences of psychotropic medication in addition to other side-effects when prescribing. For antidepressants, this would mean choosing duloxetine, agomelatine and any of the serotonin re-uptake inhibitors except sertraline. In the case of antipsychotics and mood stabilisers, atypical agents have less oral side effects than older alternatives.

A low gradient junction technique of craniospinal irradiation using volumetric-modulated arc therapy and its advantages over the conventional therapy

A technique using volumetric-modulated arc therapy (VMAT) fields for craniospinal irradiation with low dose gradients at the field junction was tested for its sensitivity to positional inaccuracy. It was compared against the conventional three-dimensional (3D) conformal radiotherapy in terms of dose uniformity at the junction. Treatment plans generated for ten patients who received craniospinal irradiation (35Gy in 21 fractions) by VMAT technique at our centre were included in this study. For these patients, 3D conformal radiotherapy plans were also generated in addition to the VMAT treatment plans. Intentional shifting of the cranial field in the superior and then in the inferior directions was done, creating a gap or overlap between the fields. Consequent changes in dose distributions in these two plans to positional inaccuracies were studied. The 3D conformal radiotherapy plans showed large dose variations at the junction due to positional shifts as compared to the VMAT plans. With a 5mm superior shift of the cranial field isocentre creating a gap between the cranial and spinal fields, the magnitudes of under-dosing were 13.9±3.6Gy and 4.8±2.0Gy for 3D conformal radiotherapy and VMAT respectively. When the cranial field was moved by 5mm inferiorly creating an overlap between the fields, overdose to the effects of 10.3±4.0Gy and 4.9±1.3Gy were observed for the 3D conformal radiotherapy plans and VMAT plans respectively. The VMAT technique is insensitive to longitudinal setup errors (1-3mm) in patients because of the existence of low dose gradients at the junction between fields. This is unlike the 3D conformal radiotherapy plans which have steep dose gradients at the field edges and thus are highly sensitive to setup errors. Such an advantage for VMAT circumvents the need for dose feathering often practiced with the 3D conformal radiotherapy technique and makes the technique simpler to follow.