Hybrid machine learning architecture for automated detection and grading of retinal images for diabetic retinopathy

Purpose: Diabetic retinopathy is the leading cause of blindness, affecting over 93 million people. An automated clinical retinal screening process would be highly beneficial and provide a valuable second opinion for doctors worldwide. A computer-aided system to detect and grade the retinal images would enhance the workflow of endocrinologists. Approach: For this research, we make use of a publicly available dataset comprised of 3662 images. We present a hybrid machine learning architecture to detect and grade the level of diabetic retinopathy (DR) severity. We also present and compare simple transfer learning-based approaches using established networks such as AlexNet, VGG16, ResNet, Inception-v3, NASNet, DenseNet, and GoogLeNet for DR detection. For the grading stage (mild, moderate, proliferative, or severe), we present an approach of combining various convolutional neural networks with principal component analysis for dimensionality reduction and a support vector machine classifier. We study the performance of these networks under different preprocessing conditions. Results: We compare these results with various existing state-of-the-art approaches, which include single-stage architectures.We demonstrate that this architecture is more robust to limited training data and class imbalance. We achieve an accuracy of 98.4% for DR detection and an accuracy of 96.3% for distinguishing severity of DR, thereby setting a benchmark for future research efforts using a limited set of training images. Conclusions: Results obtained using the proposed approach serve as a benchmark for future research efforts. We demonstrate as a proof-of-concept that an automated detection and grading system could be developed with a limited set of images and labels. This type of independent architecture for detection and grading could be used in areas with a scarcity of trained clinicians based on the necessity

Leprosy post-exposure prophylaxis with single-dose rifampicin

_Objective:_ Leprosy post-exposure prophylaxis with single-dose rifampicin (SDRPEP) has proven effective and feasible, and is recommended by WHO since 2018. This SDR-PEP toolkit was developed through the experience of the leprosy postexposure prophylaxis (LPEP) programme. It has been designed to facilitate and standardise the implementation of contact tracing and SDR-PEP administration in regions and countries that start the intervention. _Results:_ Four tools were developed, incorporating the current evidence for SDRPEP and the methods and learnings from the LPEP project in eight countries. (1) th

Occupational health issues in small-scale industries in Sri Lanka: An underreported burden

BACKGROUND: Work-related diseases and occupational accidents affect a significant number of workers globally. The majority of these diseases and accidents are reported from developing countries; and a large percentage of the workforce in developing countries is estimated to be employed in small-scale industries. Sri Lanka is no exception. These workers are exposed to occupational hazards and are at a great risk of developing work- related diseases and injuries. OBJECTIVE: To identify occupational health issues faced by small-scale industry workers in Sri Lanka. METHODS: A cross sectional study was conducted among workers in four selected small-scale industry categories in two districts of Sri Lanka. A small-scale industry was defined as a work setting with less than 20 workers. Cluster sampling using probability proportionate to size of workers was used. Eighty clusters with a cluster size of eight from each district were selected. Data was collected using a pre-tested interviewer administered questionnaire. RESULTS: Our study surveyed 198 industries. Headache (2.2, 95 CI 1.5-3.1) and eye problems (2.1, 95 CI 1.4-2.9) were the commonest general health issues detected. Back pain (4.8, 95 CI 3.8-6.1) was the most prevalent work-related musculoskeletal pain reported. Knee pain was the second highest (4.4, 95 CI 3.4-5.6). Most of the work-related musculoskeletal pain was either of short duration or long lasting. CONCLUSIONS: Work-related musculoskeletal pain was much more common than the general health issues reported. Health promotional programs at workplaces focusing ergonomics will benefit the workers at small-scale industries in Sri Lanka.</p

Sri Lankan Medical Undergraduates Awareness of Nanotechnology and Its Risks

This study examines students’ understanding of the normative connections between key concepts of nanotechnology in nanomedicine and underlying biological principles that are critical for an in-depth understanding of its therapeutic application in medical field. A structured questionnaire was distributed among randomly selected undergraduates at the Faculty of Medicine and Allied Sciences, University of Rajarata, Sri Lanka. A total of 80 students participated in this study and completed written questionnaire on nanomedicine. The outcome of this study shows that there is a strong positive response on basic knowledge on nanoscale, but the undergraduates had an average knowledge on therapeutic application related to nanomedicine. Almost all students had a good knowledge on nanoscale but they lack knowledge of the relationship between nano and nanomedicine. Specifically, students were challenged to demonstrate an integrated understanding of the nanomedicine therapeutic application. Almost 58% of them were unable to give an example of it. Also some students struggled to explain it. Furthermore, in this study it was observed that there is a positive correlation in risk benefit section related to nanomedicine. Although the outcome is preliminary in nature, the results provide cause for concern over the status of nanotechnology education in Sri Lanka which needed to be uplifted

Universal barcoding regions, rbcL, matK and trnH-psbA do not discriminate Cinnamomum species in Sri Lanka.

The genus Cinnamomum consists of about 250 species spread globally. Out of these, C. verum (C. zeylanicum), also known as true cinnamon or Ceylon cinnamon, has gained worldwide attention due to its culinary uses and medicinal values. Sri Lanka is the largest true cinnamon producer in the world and accounts for about 80-90% of global production. Other than the cultivated species, Sri Lankan natural vegetation is home to seven endemic wild species of the genus Cinnamomum. While these are underutilized, proper identification and characterization are essential steps in any sustainable conservation and utilization strategies. Currently, species identification is purely based on morphological traits, and intraspecific diversity has made it more challenging. In this study, all the eight Cinnamomum species found in Sri Lanka, C. capparu-coronde, C. citriodorum C. dubium, C. litseifolium, C. ovalifolium, C. rivulorum, C. sinharajaense, and C. verum were collected in triplicates and identified using typical morphological traits. DNA extracted with the same collection was assessed with universal barcoding regions, rbcL, matK, and trnH-psbA. While no intraspecific sequence differences were observed in C. citriodorum, C. rivulorum, and C. verum, the others had polymorphic sites in one, two, or all regions assessed. Interestingly, two individuals of C. sinharajaense had identical barcodes to the cultivated species C. verum, while the other one had one variable cite in matK region and three cites in trnH-psbA reigon. Further, one C. dubium and one C. capparu-coronde accession each had identical, rbcL, and trnH-psbA sequences while those had only a single nucleotide variation observed in matK region. Overall, the phylogeny of Cinnamomum species found in Sri Lanka could not be completely resolved with DNA barcoding regions studied

Non-alcoholic fatty liver disease: Not time for an obituary just yet!

There has been a concerted effort to change the nomenclature of non-alcoholic fatty liver disease (NAFLD) to metabolic dysfunction-associated fatty liver disease (MAFLD), and one wonders if it is appropriate and timely to bid adieu to the good old term. Numerous reasons have been put forth to justify this, as outlined in a recently published statement proposing the change. However, there are considerable flaws in the proposal, and changing NAFLD to MAFLD is unlikely to move the field forward.We have serious misgivings on this matter.o begin with, the statement by the MAFLD consensus group that the term NAFLD was coined by Ludwig and colleagues is factually incorrect. Although the histological features of NAFLD were first described decades ago, Klatskin and his colleagues, in 1979, were the first to use the term \u2018non-alcoholic liver disease\u2019.Later, while reporting similar findings, Ludwig and colleagues coined the term \u201cnon-alcoholic steatohepatitis (NASH)\u201d.Although an association between metabolic syndrome (MS) and NAFLD has been established and NAFLD termed the hepatic manifestation of MS, this generalisation has since been questioned, since the complex heterogeneity of this entity precludes any single postulation to explain its pathogenesis. Besides, individuals with normal BMI also develop NAFLD, and studies in non-Caucasian populations have shown that a significant proportion of patients with NAFLD do not have insulin resistance (IR).Further, even with elevated hepatic triacylglycerol and diacylglycerol content, hepatic IR has not been observed in murine models,and dissociation of hepatic steatosis from IR has also been noted in a subset of individuals. Importantly, in subjects with PNPLA3 polymorphisms,steatosis occurs independently of IR and serum lipid concentration. Further, increased serum bile acid levels also seem to be independently associated with NASH in non-diabetics.NAFLD is also associated with gut dysbiosis independent of BMI and IR. Finally, \u201csoft\u201d drink consumption has also been linked to the development of fatty liver independent of obesity, diabetes and hyperlipidemia.and last but not least, cigarette smoking too has been found to be an independent risk factor in NAFLD progression. Thus it is clear that pathogenesis of NAFLD is multifactorial and complex, involving multiple and divergent pathways.In Medicine, a change of name of any disease has significant implications for both medical professionals and patients.The term \u2018NAFLD\u2019 aptly describes individuals who have fatty liver but neither consume significant amounts of alcohol nor had any other reason for fatty liver. Research in NAFLD to date has failed to pinpoint any factor as the sole cause for hepatic steatosis and NAFLD still encompasses a spectrum of disorders, metabolic syndrome being a part \u2013 maybe a major part \u2013 of that spectrum with a relatively barren treatment armamentarium. Will changing nomenclature address these concerns? We fear it might paradoxically misdirect therapeutics in the direction of MS alone which may ultimately turn out to be a red herring. The consensus group found multiple faults with the term NAFLD; these include: i) NAFLD is a disease of exclusion instead of being defined by inclusion, ii) NAFLD is a vastly heterogeneous entity and cannot be managed as one single condition and iii) patients with NAFLD do consume alcohol and the impact of alcohol, albeit in non-significant amounts, is under scrutiny. In Medicine, naming a disease through exclusion has been acceptable since time immemorial. Non-Hodgkin lymphoma encompasses vastly diverse malignancies and yet the terminology very effectively delineates those disorders from Hodgkin lymphoma. Regarding heterogeneity, it is not clear how a mere change of name would make the entity more homogeneous. If the word \u201cmetabolic\u201d in MAFLD is meant as a reference to MS, it would be a rejection of much of the scientific evidence gathered on NAFLD pathogenesis. In contrast to the assertion of the proponents of MAFLD, who after splitting \u201cnonalcoholic\u201d into - \u2018non\u2019 and \u2018alcoholic\u2019, suggest that the word \u201cnon\u201d trivializes the problem while the word \u201calcoholic\u201d demeans the patient, we believe that the word \u2018nonalcoholic\u2019 does go a long way in destigmatizing the patient. The European Liver Patients Association (ELPA) is believed to have expressed displeasure with the term NAFLD to the European Commission in 2018, and suggested that a change in nomenclature was required. The degree of assertion and the rationale for such a suggestion are unclear; it is also unclear whether the diverse pathogenesis of NAFLD \u2013 especially in non-Caucasians \u2013 was considered in the decision. Further, an opinion on the impact of non-significant alcohol intake on hepatic steatosis is also unclear as acknowledged in the consensus statement. Notably, metabolic abnormalities and BMI are well described risk factors for alcoholic liver disease too,but it is unclear why both conditions more or less related to alcohol should be brought under the umbrella of MAFLD. The change of nomenclature has also been argued against since NAFLD is treated by cardiologists, diabetologists and primary care providers in addition to hepatologists; a name change could create unnecessary clinical confusion and coding issues. The heterogeneity of NAFLD and presence of multiple pathophysiological pathways inherent to its progression implies that the time is ripe to classify NAFLD in a novel way that takes into account the various pathophysiological processes. We wish to propose the \u2018MEGA-D\u2019 classification emphasising the \u2018mega diversity\u2019 or heterogeneity in NAFLD where NAFLD remains the umbrella entity with different subgroups under it (NAFLD-M: Metabolic syndrome associated NAFLD, NAFLD-E: Environmental Stressor Related NAFLD, NAFLD-G: Genetic Factor Associated NAFLD, NAFLD-A: Bile Acid Dysregulation Related NAFLD, NAFLD-D: Gut Dysbiosis Related NAFLD) representing separate pathways culminating in hepatic steatosis. We feel, instead of semantic juggling, collaborative efforts should be launched worldwide to better understand the vast heterogeneity in NAFLD across populations and ethnicities and explore its different pathophysiologic mechanisms, with the sole purpose of modifying disease progression, bolstering the treatment arsenal and curbing this epidemic

Non-resolution of non-alcoholic fatty liver disease (NAFLD) among urban, adult Sri Lankans in the general population: A prospective, cohort follow-up study.

BACKGROUND:There are few studies investigating the natural course of non-alcoholic fatty liver disease (NAFLD) in the community. We assessed resolution of NAFLD in a general population cohort of urban Sri Lankans adults. METHODS:Participants were selected by age-stratified random sampling from electoral lists. They were initially screened in 2007 and re-evaluated in 2014. On both occasions structured interview, anthropometric-measurements, liver ultrasonography, and biochemical/serological tests were performed. NAFLD was diagnosed on ultrasound criteria for fatty liver, safe-alcohol consumption (<14-units/week for men, <7-units/week for women) and absence of hepatitis B/C markers. Non-NAFLD was diagnosed on absence of any ultrasound criteria for fatty liver and safe-alcohol consumption. Resolution of NAFLD was defined as absence of ultrasound criteria for fatty liver. Changes in anthropometric indices [Weight, Body-Mass-Index (BMI), waist-circumference (WC), waist-hip ratio (WHR)], clinical [systolic blood pressure (SBP), diastolic blood pressure (DBP)] and biochemical measurements [Triglycerides (TG), High Density Lipoprotein (HDL), Total Cholesterol (TC), HbA1c%] at baseline and follow-up were compared. RESULTS:Of the 2985 original study participants, 2148 (71.9%) attended follow-up after 7 years. This included 705 who had NAFLD in 2007 and 834 who did not have NAFLD in 2007. Out of 705 who had NAFLD in 2007, 11(1.6%) changed their NAFLD status due to excess alcohol consumption. After controlling for baseline values, NAFLD patients showed significant reduction in BMI, weight, WHR, HDL and TC levels and increase in HbA1c levels compared to non-NAFLD people. Despite this, none of them had complete resolution of NAFLD. CONCLUSION:We did not find resolution of NAFLD in this general population cohort. The observed improvements in anthropometric, clinical and biochemical measurements were inadequate for resolution of NAFLD