ABSTRACT
The syntheses, coordination chemistry, and Mössbauer spectroscopy of hepta-iron(III) complexes using derivatised salicylaldoxime ligands from two categories; namely, 'single-headed' (H2L) and 'double-headed' (H4L) salicylaldoximes are described. All compounds presented here share a [Fe3-µ3-O] core in which the iron(III) ions are µ3-hydroxo-bridged in the complex C1 and µ3-oxo-bridged in C2 and C3. Each compound consists of 2 × [Fe3-µ3-O] triads that are linked via a central [Fe(µ2-OH)6]3- ion. In addition to the charge balance and microanalytical evidence, Mössbauer measurements support the fact that the triads in C1 are µ3-OH bridged and are µ3-O bridged in C2 and C3.
ABSTRACT
PURPOSE: To investigate the physicochemical compatibility of caffeine citrate and caffeine base injections with 43 secondary intravenous (IV) drugs used in Neonatal Intensive Care Unit (NICU) settings. METHODS: Caffeine citrate (20 mg/mL or 10 mg/mL) or caffeine base injection (10 mg/mL) were mixed in a volume ratio of 1:1 with the secondary drug solution to simulate Y-site co-administration procedures in NICUs. Physical compatibility was evaluated based on visual observation for 2 h, against a black and white background and under polarised light, for changes in colour, precipitation, haze and evolution of gas. Chemical compatibility was determined from caffeine concentration measurements, using a validated high-performance liquid chromatography assay. RESULTS: Six of the 43 secondary drugs tested (aciclovir, amphotericin (liposomal), furosemide, hydrocortisone, ibuprofen and ibuprofen lysine) were physically incompatible with caffeine citrate undiluted injection (20 mg/mL), at their high-end, clinically relevant concentrations for NICU settings. However, when tested at lower concentrations, hydrocortisone (1 mg/mL) was physicochemically compatible, whereas furosemide (0.2 mg/mL) was physically incompatible with caffeine citrate. The six drugs which showed physical incompatibility with caffeine citrate 20 mg/mL injection were also physically incompatible with caffeine citrate 10 mg/mL solution. All 43 secondary drugs tested were physicochemically compatible with caffeine base injection. CONCLUSIONS: Most secondary test drugs, except aciclovir, amphotericin (liposomal), furosemide, hydrocortisone, ibuprofen and ibuprofen lysine, were physicochemically compatible with caffeine citrate injection. Caffeine base injection was physicochemically compatible with all 43 test drugs tested.
Subject(s)
Caffeine , Citrates , Drug Incompatibility , Caffeine/chemistry , Caffeine/administration & dosage , Humans , Citrates/chemistry , Citrates/administration & dosage , Infant, Newborn , Intensive Care, Neonatal , Intensive Care Units, Neonatal , Acyclovir/administration & dosage , Acyclovir/chemistryABSTRACT
Sildenafil is used to treat pulmonary hypertension in neonatal intensive care unit (NICU) settings. As multiple intravenous (IV) medications are co-administered in NICU settings, we sought to investigate the physicochemical compatibility of sildenafil with a range of IV drugs. Sildenafil 600 mcg/mL or 60 mcg/mL was mixed 1:1 with the secondary drug solution to simulate Y-site co-administration procedures. Physical compatibility was evaluated by visual observation against a black and white background and under polarized light for two hours for changes in colour, precipitation, haze and evolution of gas. Chemical compatibility was determined from sildenafil concentrations, using a validated, stability-indicating high-performance liquid chromatography assay. Sildenafil 600 mcg/mL was physicochemically compatible with 29 of the 45 drugs tested at 'high-end' clinical concentrations and physically incompatible with 16 drugs and six '2-in-1' parenteral nutrition solutions. Sildenafil 600 mcg/mL was compatible with lower, clinically relevant concentrations of calcium gluconate, heparin and hydrocortisone. Aciclovir, amoxicillin, ampicillin, ibuprofen lysine, indometacin, phenobarbitone and rifampicin were incompatible with sildenafil 600 mcg/mL, however these IV medications were compatible with sildenafil 60 mcg/mL. Sildenafil 600 mcg/mL and 60 mcg/mL were incompatible with amphotericin, flucloxacillin, furosemide, ibuprofen, meropenem and sodium bicarbonate. Sildenafil compatibility with commonly used syringe filters was also investigated. Sildenafil solution was compatible with nylon syringe filters, however, absorption/adsorption loss occurred with polyethersulfone and cellulose ester filters.
ABSTRACT
BACKGROUND: Although the benefits of regular physical activity (PA) after stroke are well established, many stroke survivors do not achieve recommended PA levels. To date, studies exploring determinants to PA have not used a behaviour change theory and focused on stroke survivors with physical disabilities. As a precursor to an intervention development study, we aimed to use the Theoretical Domains Framework (TDF) to identify factors influencing PA in stroke survivors with physical disabilities in Singapore. METHODS: Between November 2021 and January 2022, we conducted interviews with 19 community-dwelling stroke survivors with a weak arm and/or leg. An interview guide based on the TDF was developed. We analysed the data deductively by coding interview transcripts into the theoretical domains of the TDF, and then inductively by generating themes and belief statements. To identify relevant TDF domains, we prioritised the domains based on the frequencies of the belief statements, presence of conflicting belief statements and evidence of strong belief statements. RESULTS: Eight of the 14 TDF domains were relevant, and included environmental context and resources, knowledge, social influences, emotion, reinforcement, behavioural regulation, skills and beliefs about capabilities. The lack of access, suitable equipment and skilled help often limited PA participation at public fitness spaces such as parks, gyms and swimming pools (environmental context and resources). While a few stroke survivors expressed that they had the skills to engage in regular PA, most expressed not knowing how much and how hard to work, which exercises to do, which equipment to use and how to adapt exercises and equipment (knowledge and skills). This often left them feeling afraid to try new activities or venture out to new places for fear of the unknown or adverse events (e.g., falls) (emotion). For some, doing the activities in a group encourage them to get out and engage in PA (social influences). CONCLUSIONS: In stroke survivors with physical disabilities, environmental context and resources had a significant influence on PA participation, and this often had a spill over effect into other domains. Our results inform a complex behaviour change intervention to improve PA after stroke, and has implications for intervention design for people with physical disabilities.
Subject(s)
Disabled Persons , Exercise , Humans , Qualitative Research , Emotions , Survivors/psychologyABSTRACT
Our objective was to establish and test a machine learning-based screening process that would be applicable to systematic reviews in pharmaceutical sciences. We used the SPIDER (Sample, Phenomenon of Interest, Design, Evaluation, Research type) model, a broad search strategy, and a machine learning tool (Research Screener) to identify relevant references related to y-site compatibility of 95 intravenous drugs used in neonatal intensive care settings. Two independent reviewers conducted pilot studies, including manual screening and evaluation of Research Screener, and used the kappa-coefficient for inter-reviewer reliability. After initial deduplication of the search strategy results, 27 597 references were available for screening. Research Screener excluded 1735 references, including 451 duplicate titles and 1269 reports with no abstract/title, which were manually screened. The remainder (25 862) were subject to the machine learning screening process. All eligible articles for the systematic review were extracted from <10% of the references available for screening. Moderate inter-reviewer reliability was achieved, with kappa-coefficient ≥0.75. Overall, 324 references were subject to full-text reading and 118 were deemed relevant for the systematic review. Our study showed that a broad search strategy to optimize the literature captured for systematic reviews can be efficiently screened by the semi-automated machine learning tool, Research Screener.
Subject(s)
Intensive Care, Neonatal , Machine Learning , Systematic Reviews as Topic , Humans , Infant, Newborn , Reproducibility of ResultsABSTRACT
Background: There is limited information about diabetes and thyroid related autoantibodies in children with type 1 diabetes (T1D) or their siblings in Sri Lanka. Objectives: To assess in T1D children and their unaffected siblings the prevalence of autoantibodies to (1) glutamic acid decarboxylase (GADA), insulinoma associated antigen-2 (IA-2A) and zinc transporter 8 (ZnT8A) using 3 Screen ICA™ (3-Screen) and individual ELISA assays; (2) insulin (IAA); and (3) thyroid peroxidase (TPOA), thyroglobulin (TgA) and the TSH receptor (TSHRA). Methods: We selected - (a) consecutive T1D children, and (b) their unaffected siblings of both sexes, from the T1D Registry at Lady Ridgeway Hospital, Colombo. Results: The median age (IQR) of 235 T1D children and 252 unaffected siblings was 11 (8.4, 13.2) and 9 (5.4, 14.9) years respectively, and the duration of T1D was 23 (7, 54) months. (1) T1D children (a) 79.1% were 3-Screen positive; (b) all 3-Screen positives were individual antibody positive (GADA in 74%; IA-2A 31.1%; ZnT8A 38.7%); (c) and were younger (p=0.01 vs 3-Screen negatives); (d) multiple autoantibodies were present in 45.1%; (e) IA-2A (p=0.002) and ZnT8A (p=0.006) prevalence decreased with T1D duration. (f) TPOA and TgA prevalence was higher in T1D children compared to unaffected siblings (28%, p=0.001 and 31%, p=0.004, respectively). (2) Unaffected siblings (a) 6.3% were 3-Screen positive (p=0.001 vs T1D), and 2.4% were positive for IAA; (b) four subjects had two diabetes related autoantibodies, one of whom developed dysglycaemia during follow-up. Conclusions: The 3-Screen assay, used for the first time in Sri Lankan T1D children and their siblings as a screening tool, shows a high prevalence of T1D related Abs with a high correlation with individual assays, and is also a helpful tool in screening unaffected siblings for future T1D risk. The higher prevalence of thyroid autoantibodies in T1D children is consistent with polyglandular autoimmunity.
Subject(s)
Diabetes Mellitus, Type 1 , Male , Female , Humans , Child , Sri Lanka , Siblings , Thyroid Gland , Prevalence , AutoantibodiesABSTRACT
Syntheses and magnetic and structural characterization of hexa-iron complexes of derivatized salicylaldoximes are discussed. Complexation of Fe(BF4)2·6H2O with each ligand (H2 L1 and H4 L2) in a methanolic-pyridine solution resulted in hexa-iron compounds (C1 and C2, respectively), which each contain two near-parallel metal triangles of [Fe3-µ3-O], linked by six fluoride bridges and stabilized by a hydrogen-bonded proton between the µ3-O groups. Within each metal triangle of C2, Fe(III) ions are connected via the amine "straps" of (H4 L2-2H). Variable-temperature magnetic susceptibility and Mössbauer data of C1 and C2 indicate the presence of dominant antiferromagnetic interactions between the high-spin (S = 5/2) Fe(III) centers. For C1, two quadrupole doublets are observed at room temperature and 5 K, consistent with structural data from which discrete but disordered [Fe3-µ3-O] and [Fe3-µ3-OH] species were inferred. For C2, a single sharp quadrupole doublet with splitting intermediate between those determined for C1 was observed, consistent with the symmetric [Fe3-µ3-O···H···µ3-O-Fe3] species inferred crystallographically from the very short µ3-O···µ3-O separation. The differences in the physical properties of the complexes, as seen in the Mössbauer, X-ray, and magnetic data, are attributed to the conformational flexibility imparted by the nature of the linkages between the closely related ligands.
ABSTRACT
BACKGROUND: Median overall survival (OS) for women with high-grade serous ovarian cancer (HGSOC) is â¼4 years, yet survival varies widely between patients. There are no well-established, gene expression signatures associated with prognosis. The aim of this study was to develop a robust prognostic signature for OS in patients with HGSOC. PATIENTS AND METHODS: Expression of 513 genes, selected from a meta-analysis of 1455 tumours and other candidates, was measured using NanoString technology from formalin-fixed paraffin-embedded tumour tissue collected from 3769 women with HGSOC from multiple studies. Elastic net regularization for survival analysis was applied to develop a prognostic model for 5-year OS, trained on 2702 tumours from 15 studies and evaluated on an independent set of 1067 tumours from six studies. RESULTS: Expression levels of 276 genes were associated with OS (false discovery rate < 0.05) in covariate-adjusted single-gene analyses. The top five genes were TAP1, ZFHX4, CXCL9, FBN1 and PTGER3 (P < 0.001). The best performing prognostic signature included 101 genes enriched in pathways with treatment implications. Each gain of one standard deviation in the gene expression score conferred a greater than twofold increase in risk of death [hazard ratio (HR) 2.35, 95% confidence interval (CI) 2.02-2.71; P < 0.001]. Median survival [HR (95% CI)] by gene expression score quintile was 9.5 (8.3 to -), 5.4 (4.6-7.0), 3.8 (3.3-4.6), 3.2 (2.9-3.7) and 2.3 (2.1-2.6) years. CONCLUSION: The OTTA-SPOT (Ovarian Tumor Tissue Analysis consortium - Stratified Prognosis of Ovarian Tumours) gene expression signature may improve risk stratification in clinical trials by identifying patients who are least likely to achieve 5-year survival. The identified novel genes associated with the outcome may also yield opportunities for the development of targeted therapeutic approaches.
Subject(s)
Cystadenocarcinoma, Serous , Ovarian Neoplasms , Cystadenocarcinoma, Serous/genetics , Female , Humans , Ovarian Neoplasms/genetics , Prognosis , Proportional Hazards Models , Survival Analysis , TranscriptomeABSTRACT
BACKGROUND: Recent advances in treatment for stroke give new possibilities for optimizing outcomes. To deliver these prehospital care needs to become more efficient. AIM: To develop a framework to support improved delivery of prehospital care. The recommendations are aimed at clinicians involved in prehospital and emergency health systems who will often not be stroke specialists but need clear guidance as to how to develop and deliver safe and effective care for acute stroke patients. METHODS: Building on the successful implementation program from the Global Resuscitation Alliance and the Resuscitation Academy, the Utstein methodology was used to define a generic chain of survival for Emergency Stroke Care by assembling international expertise in Stroke and Emergency Medical Services (EMS). Ten programs were identified for Acute Stroke Care to improve survival and outcomes, with recommendations for implementation of best practice. CONCLUSIONS: Efficient prehospital systems for acute stroke will be improved through public awareness, optimized prehospital triage and timely diagnostics, and quick and equitable access to acute treatments. Documentation, use of metrics and transparency will help to build a culture of excellence and accountability.
Subject(s)
Emergency Medical Services , Stroke , Emergency Service, Hospital , Humans , Stroke/therapy , TriageABSTRACT
INTRODUCTION: Russell's viper envenoming in dogs is a significant problem in Sri Lanka. The current study focused on investigating clinical profile, laboratory findings of three selected tests and to develop a treatment strategy with Indian polyvalent Anti-Venom Serum (AVS). It was also intended to report adverse effects and complications caused by both Russell's viper venom (RVV) and AVS in Russell's Viper (RV) envenomed dogs. OBJECTIVE: To evaluate and report the clinical manifestations, to find out the minimum effective vials of AVS and to record AVS induced adverse reactions of RV envenoming in dogs. MATERIALS AND METHODS: A prospective study was conducted on Russell's viper bitten dogs (nâ¯=â¯65) admitted to the Veterinary Teaching Hospital (VTH) in Sri Lanka. Indian polyvalent AVS was used to treat all the envenomed dogs. The number of vials of AVS that was administered to a patient was decided upon by a second degree polynomial model with a number of vials of AVS in the X axis verses Prothrombine Time (PT), Activated Partial Thromboplastine Time (aPTT) and Clotting Time (CT) in the Y axis respectively. RESULTS: Varying degrees of pain were exhibited by all the victim dogs. Mild swelling and necrosis at the site of bite was seen in 54% (nâ¯=â¯35) and 37% (nâ¯=â¯24) of dogs respectively. Prolonged values of, PT, aPTT and CT were seen from all the RV envenomed dogs. The mean leukocyte count in these dogs was 39.79â¯×â¯103/µL (normal range; 4-20â¯×â¯103/µL) (IQR:29.05â¯×â¯103/µL-45.92â¯×â¯103/µL). Statistical analysis showed that the initial vials of 7 AVS would be the minimum required vials. Therefore, a range of 6-15 AVS vials in total were administered to these dogs and in 7.6% (nâ¯=â¯5) of dogs, the results of PT, aPTT and CT became normal with 6 AVS vials at 32-97â¯minutes. Acute Renal Failure (ARF) was detected from 29% (nâ¯=â¯19) of dogs as a complication. CONCLUSIONS: Systemic clinical signs of haemorrhagic lesions, cardio respiratory toxicities were common in Russell's viper envenomed dogs. Initially 6 vials of AVS must be administered. AVS induced reactions were reported commonly. Russell's viper envenoming was found to be lethal in dogs.
ABSTRACT
Anion hydrolysis reactions between salicylaldoximato ligands (L'-L''') and copper and iron BF4- metal salts, have resulted in the formation of new salicylaldoximato borate containing transition metal complexes: [Fe2(L' + 2H)2](BF4)2(MeOH)4 (C1), [Fe3(L'' + 4H)(OH)2(Py)2](BF4)2(H2O)2(Py)2 (C2), and [Cu2(L''' + H)2Cl2] (C3). Each of the complexes have been structurally characterised, revealing the indirect role boron plays in the formation of these complexes. For complexes C1 and C2, Mössbauer spectroscopy confirmed the existence of Fe(iii) oxidation states. SQUID magnetometry measurements were performed on complexes C2 and C3, revealing the presence of two competing exchange pathways between the three Fe(iii) centres in C2, with antiferromagnetic exchange dominating. For C3 weak antiferromagnetic exchange dominated between the two Cu(ii) centres.
ABSTRACT
Cartilaginous fish are the evolutionarily oldest group of animals which possess antibodies, T cell receptors and major histocompatibility complex (MHC). The immunoglobulin novel antigen receptor (IgNAR) found in cartilaginous fish is a heavy chain homodimer which lacks light chain. The presence of non-canonical cysteine molecules and lack of CDR2 region make it more significant. To synthesize active binding domains based on variable region of IgNAR (VNAR), knowledge on the constant region dynamics play a significant role. The IgNAR exhibit species variations in its primary sequence features; hence, this study was conducted to determine the IgNAR heavy chain constant domain of the brownbanded bamboo shark (Chiloscyllium punctatum). Peripheral blood leukocytes (PBL) isolated from adult bamboo sharks were used to synthesize a cDNA library. A total of four billion residues of two million sequences (average length 218.41 bp) were obtained. Assembled sequences were aligned with published cartilaginous fish IgNAR constant region sequences. Transcriptome analysis revealed two distinct types of IgNAR in the brownbanded bamboo shark. Also, constant-1 domain sequences displayed 13 unique sequences which may reflect the least number of IgNAR gene clusters. The phylogenetic analysis revealed the closest relationship with the nurse shark (Ginglymostoma cirratum) followed by the wobbegong shark (Orectolobus maculatus) which belong to the same order Orectolobiformes. Analysis of the constant domains of the brownbanded bamboo shark IgNAR revealed an evolutionarily conserved nature and this knowledge can be used to design primers for VNAR cloning. Furthermore, knowledge on the structural features in IgNAR constant domains that increase the stability could be useful in the process of stabilizing human immunoglobulins.
Subject(s)
Adaptive Immunity/genetics , Fish Diseases/immunology , Gene Expression Regulation/immunology , Receptors, Antigen/genetics , Receptors, Antigen/immunology , Sharks/genetics , Sharks/immunology , Amino Acid Sequence , Animals , Base Sequence , Fish Proteins/chemistry , Fish Proteins/genetics , Fish Proteins/immunology , Gene Expression Profiling/veterinary , Immunoglobulin Heavy Chains/chemistry , Immunoglobulin Heavy Chains/genetics , Immunoglobulin Heavy Chains/immunology , Male , Phylogeny , Receptors, Antigen/chemistry , Sequence Alignment/veterinaryABSTRACT
AIM: The objective of this study was to describe and characterize the postmortem and histopathological findings of putative esophageal chondrosarcoma associated with Spirocerca lupi. MATERIALS AND METHODS: Spirocerca-associated esophageal nodules were collected from 54 dogs at postmortem examination and were stained with hematoxylin and eosin. Of the cases examined, 15 were selected randomly for further investigation, of which 11 were classified as non-neoplastic nodules while 4 had changes reflecting a neoplastic process. RESULTS: In all four neoplastic cases, the wall of the esophageal nodules contained islands and nests of highly proliferative atypical chondroblasts within a cartilaginous matrix. However, there was no statistically significant association between gender (p=0.228), age (p=0.568), and breeds (p>0.05) with the occurrence of spirocercosis. Moreover, all esophageal nodules identified were located near the caudal segment, and their diameters ranged from 1 to 6 cm (4.7±1.5 cm). A number of worms in each nodule varied from 5 to 25 (11.3±5). CONCLUSION: Histopathology and cytology revealed that the wall of the esophageal nodules contained islands and nests of highly proliferative atypical chondroblasts within a cartilaginous matrix, a rare finding, and clinical challenge in spirocercosis.
ABSTRACT
OBJECTIVES: Physical inactivity is associated with high cardiovascular risk. The purpose of this study was to study physical activity levels of patients with acute coronary syndrome (ACS). METHODOLOGY: A total of 504 patients, from the Professorial Unit of the Colombo South Teaching Hospital completed the International Physical Activity Questionnaire (IPAQ). IPAQ is a validated questionnaire used internationally to objectively measure physical activity. Both the total volume and the number of sessions of activity are included in the IPAQ. Populations are divided into three levels based on physical activity levels: low, moderate and high activity. RESULTS: Out of 504 patients, 128 (25.1%) were highly active, 87 (17.1%) were minimally active and 289 (56.7%) were found be inactive. When considering mets per week 134 (26.3%) spent less than 1000mets/week. Physical activity levels of men and women were similar (p=0.06). There was a no significant association between body mass index (BMI) with total IPAQ score (p=0.11). There was no difference in the physical activity levels of patients presenting with different types of ACS: ST-Elevation Myocardial Infarction (STEMI), non-ST-elevation myocardial infarction (NSTEMI) or unstable angina (UA) (p=0.36). The activity levels did not affect the severity of ACS assessed by Thrombolysis In Myocardial Infarction (TIMI) scores. (NSTEMI/UA p=0.24, STEMI p=0.10). CONCLUSION: In Sri Lanka, a majority of patients with ACS were physically inactive. Physical inactivity is one of the remediable major risk factors of ACS and an active life style should be promoted.
Subject(s)
Acute Coronary Syndrome/physiopathology , Exercise/physiology , Acute Coronary Syndrome/diagnosis , Acute Coronary Syndrome/epidemiology , Aged , Exercise Test , Female , Humans , Incidence , Male , Middle Aged , Retrospective Studies , Sri Lanka/epidemiology , Surveys and Questionnaires , Survival Rate/trendsABSTRACT
In this retrospective multicentre study, we investigated the outcomes of elderly primary central nervous system lymphoma (PCNSL) patients (⩾65 years) who underwent high-dose chemotherapy followed by autologous stem cell transplantation (HDT-ASCT) at 11 centres between 2003 and 2016. End points included remission, progression-free survival (PFS), overall survival (OS) and treatment-related mortality. We identified 52 patients (median age 68.5 years, median Karnofsky Performance Status before HDT-ASCT 80%) who all underwent thiotepa-based HDT-ASCT. Fifteen patients (28.8%) received HDT-ASCT as first-line treatment and 37 (71.2%) received it as second or subsequent line. Remission status before HDT-ASCT was: CR 34.6%, PR 51.9%, stable disease 3.8% and progressive disease 9.6%. Following completion of HDT-ASCT, 36 patients (69.2%) achieved CR (21.2% first-line setting and 48.1% second or subsequent line setting) and 9 (17.3%) PR (5.8% first-line setting and 11.5% second or subsequent line setting). With a median follow-up of 22 months after HDT-ASCT, median PFS and OS were reached after 51.1 and 122.3 months, respectively. The 2-year PFS and OS rates were 62.0% and 70.8%, respectively. We observed two HDT-ASCT-associated deaths (3.8%). In selected elderly PCNSL patients, HDT-ASCT, using thiotepa-based conditioning regimes, is feasible and effective. Further prospective and comparative studies are warranted to further evaluate the role of HDT-ASCT in elderly PCNSL patients.
Subject(s)
Central Nervous System Neoplasms/therapy , Hematopoietic Stem Cell Transplantation/methods , Thiotepa/administration & dosage , Aged , Aged, 80 and over , Antineoplastic Agents, Alkylating/administration & dosage , Central Nervous System Neoplasms/mortality , Combined Modality Therapy , Disease-Free Survival , Europe , Hematopoietic Stem Cell Transplantation/mortality , Humans , Remission Induction , Retrospective Studies , Survival Analysis , Transplantation Conditioning/methods , Transplantation Conditioning/mortality , Transplantation, AutologousABSTRACT
Introduction: Over the years, Sri Lanka has achieved remarkable health gains for the money spent on health. Currently about 1450 doctors enter the health system annually. While some advocate opening up of new medical schools to address an apparent shortage of doctors in the country, others argue against it. Objective: To identify the number of doctors Sri Lanka need. Methodology: System dynamics, an analytical modelling approach and a methodology for studying complex feedback systems was used. Two sub models of "need" and "supply" were developed and simulated for a period of 15 years from 2017 to 2032 Results: At present the doctor to population ratio is 1:671 and 91% of the need has been met. This study shows that currently there is a shortage of doctors in the country. However, the supply will match the need by 2025/26. Increasing the number of doctors, will result in oversupply of doctors towards the latter part of the next decade. Conclusions: There is no acute necessity to open up new Medical Schools. However comprehensive health workforce analysis needs to be done once in 5 years and the number of doctors to be trained, decided accordingly.