Prevalence, Habit Pattern, and Awareness on Harmful Effects of Tobacco/Areca Nut Use among Patients Visiting a Tertiary Care Center in Sri Lanka.

S.P. Kalpana Jeewanthi SubasingheBackground The carcinogenicity of tobacco and areca nut is well established worldwide. Areca nut is the fourth most common psychoactive substance identified recently. The effects of areca nut on the autonomic nervous system make the users dependent on the habit which has been an emerging health issue among Sri Lankan adults and adolescents. This study aimed to evaluate the prevalence and patterns of these risk habits among the patients attending a tertiary care center in Sri Lanka, and their awareness of the harmful effects of the habit. Method A hospital-based cross-sectional study was conducted among 512 patients using an interviewer-administered questionnaire. Results The sample consisted of 167 (33%) tobacco consumers. The average age of the initiation of tobacco consumption was 23.66 years (standard deviation ± 8.04). Age ( p = 0.001), gender ( p = 0.001), income ( p = 0.005), and educational level ( p = 0.001) are significantly associated with tobacco consumption. There is a strong likelihood for tobacco consumers to consume areca nut (odds ratio [OR] 30.58, 95% confidence interval [CI] 17.05-54.88) and alcohol (OR 11.16, 95% CI 6.91-17.98) at any stage in their lives. The majority of the tobacco consumers (61%) were smokeless tobacco users. Areca nut consumers are 0.44 times more likely to know its carcinogenic effects than nonconsumers (95% CI 0.28-0.69). Tobacco consumers are more likely to be aware of the harmful effects of tobacco consumption than nonconsumers (OR 1.11, 95% CI 0.45-2.74). Sixty percent have made at least one attempt to quit the habit. Sixty-two percent of the unsuccessful quitters reported the reason as "addiction." Conclusion Prevalence of smokeless tobacco consumption prevails at a high level among Sri Lankans. Tobacco and areca nut users are more likely to be aware of its harmful effects than the nonconsumers but unable to quit the habit due to the psychoactive properties of tobacco and areca nut.

Choice Modeling for the Commercial Cultivation of Underutilized Aromatic Plants for Producing Mosquito Repellents: Targeting Rural Sector Income Generation.

Tropical countries face considerable economic losses due to mosquito-borne diseases which can be effectively combatted using plant-based mosquito repellents. Therefore, using a questionnaire survey, we selected the 25 top-ranked common but underutilized aromatic plants with mosquito repellent ability in Sri Lanka to investigate the rural sector's willingness to cultivate and supply them. Cinnamomum verum, Citrus aurantiifolia, Citrus sinensis, Citrus reticulata, Aegle marmelos, and Ocimum tenuiflorum were the common species thus identified. The willingness to cultivate and supply aromatic plants with mosquito repellent ability varied between 88% and 60%. The Chi-squared test indicated a significant association between gender and willingness to cultivate and supply these plants. Men had a higher willingness (82%). Persons formally educated up to elementary school level had the highest willingness (85%). The willingness from households with many non-income-generating members was 100%. The random forest model developed in this study identifies farmers' willingness to cultivate and supply aromatic plants with mosquito repellent properties. It was trained using an upsampling strategy. Our findings aid in understanding the scenarios involved with introducing, cultivating, and supplying aromatic plants.

Toward quantification of hypoxia using fluorinated EuII/III-containing ratiometric probes.

Hypoxia is a prognostic biomarker of rapidly growing cancers, where the extent of hypoxia is an indication of tumor progression and prognosis; therefore, hypoxia is also used for staging while performing chemo- and radiotherapeutics for cancer. Contrast-enhanced MRI using EuII-based contrast agents is a noninvasive method that can be used to map hypoxic tumors, but quantification of hypoxia using these agents is challenging due to the dependence of signal on the concentration of both oxygen and EuII. Here, we report a ratiometric method to eliminate concentration dependence of contrast enhancement of hypoxia using fluorinated EuII/III-containing probes. We studied three different EuII/III couples of complexes containing 4, 12, or 24 fluorine atoms to balance fluorine signal-to-noise ratio with aqueous solubility. The ratio between the longitudinal relaxation time (T1) and 19F signal of solutions containing different ratios of EuII- and EuIII-containing complexes was plotted against the percentage of EuII-containing complexes in solution. We denote the slope of the resulting curves as hypoxia indices because they can be used to quantify signal enhancement from Eu, that is related to oxygen concentration, without knowledge of the absolute concentration of Eu. This mapping of hypoxia was demonstrated in vivo in an orthotopic syngeneic tumor model. Our studies significantly contribute toward improving the ability to radiographically map and quantify hypoxia in real time, which is critical to the study of cancer and a wide range of diseases.

Reactivity of a Dithiocarbamate-Ligated [WVI≡S] Complex with Hydride Donors: Toward a Synthetic Mimic of Formate Dehydrogenase.

Formate dehydrogenase (FDH) enzymes catalyze redox interconversion of CO2 and HCO2-, with a key mechanistic step being the transfer of H- from HCO2- to an oxidized active site featuring a [MVI≡S] group in a sulfur-rich environment (M = Mo or W). Here, we report reactivity studies with HCO2- and other reducing agents of a synthetic [WVI≡S] model complex ligated by dithiocarbamate (dtc) ligands. Reactions of [WVIS(dtc)3][BF4] (1) conducted in MeOH solvent generated [WVIS(S2)(dtc)2] (2) and [WVS(µ-S)(dtc)]2 (3) products by a solvolysis pathway that was accelerated by the presence of [Me4N][HCO2] but did not require it. Under MeOH-free conditions, the reaction of 1 with [Et4N][HCO2] produced some [WIV(µ-S)(µ-dtc)(dtc)]2 (4), but predominantly [WV(dtc)4]+ (5), along with stoichiometric CO2 detected by headspace gas chromatography (GC) analysis. Stronger hydride sources such as K-selectride generated the more reduced analogue, 4, exclusively. The reaction of 1 with the electron donor, CoCp2, also produced 4 and 5 in varying amounts depending on reaction conditions. These results indicate that formates and borohydrides act as electron donors rather than hydride donors toward 1, an outcome that diverges from the behavior of FDHs. The difference is ascribed to the more oxidizing potential of [WVI≡S] complex 1 when supported by monoanionic dtc ligands that allows electron transfer to outcompete hydride transfer, as compared to the more reduced [MVI≡S] active sites supported by dianionic pyranopterindithiolate ligands in FDHs.

Outersphere Approach to Increasing the Persistance of Oxygen-Sensitive Europium(II)-Containing Contrast Agents for Magnetic Resonance Imaging with Perfluorocarbon Nanoemulsions toward Imaging of Hypoxia.

Radiographic mapping of hypoxia is needed to study a wide range of diseases. Complexes of Eu(II) are a promising class of molecules to fit this need, but they are generally limited by their rapid oxidation rates in vivo. Here, a perfluorocarbon-nanoemulsion perfused with N2 , forms an interface with aqueous layers to hinder oxidation of a new perfluorocarbon-soluble complex of Eu(II). Conversion of the perfluorocarbon solution of Eu(II) into nanoemulsions results in observable differences between reduced and oxidized forms by magnetic resonance imaging both in vitro and in vivo. Oxidation in vivo occurrs over a period of ≈30 min compared to <5 min for a comparable Eu(II)-containing complex without nanoparticle interfaces. These results represent a critical step toward delivery of Eu(II)-containing complexes in vivo for the study of hypoxia.

A Mouse Holder for Awake Functional Imaging in Unanesthetized Mice: Applications in 31P Spectroscopy, Manganese-Enhanced Magnetic Resonance Imaging Studies, and Resting-State Functional Magnetic Resonance Imaging.

Anesthesia is often used in preclinical imaging studies that incorporate mouse or rat models. However, multiple reports indicate that anesthesia has significant physiological impacts. Thus, there has been great interest in performing imaging studies in awake, unanesthetized animals to obtain accurate results without the confounding physiological effects of anesthesia. Here, we describe a newly designed mouse holder that is interfaceable with existing MRI systems and enables awake in vivo mouse imaging. This holder significantly reduces head movement of the awake animal compared to previously designed holders and allows for the acquisition of improved anatomical images. In addition to applications in anatomical T2-weighted magnetic resonance imaging (MRI), we also describe applications in acquiring 31P spectra, manganese-enhanced magnetic resonance imaging (MEMRI) transport rates and resting-state functional magnetic resonance imaging (rs-fMRI) in awake animals and describe a successful conditioning paradigm for awake imaging. These data demonstrate significant differences in 31P spectra, MEMRI transport rates, and rs-fMRI connectivity between anesthetized and awake animals, emphasizing the importance of performing functional studies in unanesthetized animals. Furthermore, these studies demonstrate that the mouse holder presented here is easy to construct and use, compatible with standard Bruker systems for mouse imaging, and provides rigorous results in awake mice.

Dual-Mode Tumor Imaging Using Probes That Are Responsive to Hypoxia-Induced Pathological Conditions.

Hypoxia in solid tumors is associated with poor prognosis, increased aggressiveness, and strong resistance to therapeutics, making accurate monitoring of hypoxia important. Several imaging modalities have been used to study hypoxia, but each modality has inherent limitations. The use of a second modality can compensate for the limitations and validate the results of any single imaging modality. In this review, we describe dual-mode imaging systems for the detection of hypoxia that have been reported since the start of the 21st century. First, we provide a brief overview of the hallmarks of hypoxia used for imaging and the imaging modalities used to detect hypoxia, including optical imaging, ultrasound imaging, photoacoustic imaging, single-photon emission tomography, X-ray computed tomography, positron emission tomography, Cerenkov radiation energy transfer imaging, magnetic resonance imaging, electron paramagnetic resonance imaging, magnetic particle imaging, and surface-enhanced Raman spectroscopy, and mass spectrometric imaging. These overviews are followed by examples of hypoxia-relevant imaging using a mixture of probes for complementary single-mode imaging techniques. Then, we describe dual-mode molecular switches that are responsive in multiple imaging modalities to at least one hypoxia-induced pathological change. Finally, we offer future perspectives toward dual-mode imaging of hypoxia and hypoxia-induced pathophysiological changes in tumor microenvironments.

Novel frameshift variant in the PCNT gene associated with Microcephalic Osteodysplastic Primordial Dwarfism (MOPD) Type II and small kidneys.

BACKGROUND: Microcephalic Osteodysplastic Primordial Dwarfism (MOPD) Type II is an autosomal recessive condition encompassing a heterogeneous group of disorders characterized by symmetrical growth retardation leading to dwarfism, microcephaly, and a range of multiple medical complications including neurovascular diseases. Biallelic pathogenic variants in the pericentrin gene (PCNT) have been implicated in its pathogenesis. CASE PRESENTATION: We performed whole-exome sequencing to ascertain the diagnosis of a 2 year and 6 months old boy who presented with severe failure to thrive, microcephaly, and facial gestalt suggestive of MOPD Type II which included features such as retrognathia, small ears, prominent nasal root with a large nose, microdontia, sparse scalp hair, bilateral fifth finger clinodactyly. He had a small ostium secundum atrial septal defect and bilaterally small kidneys. Microcephalic Osteodysplastic Primordial Dwarfism (MOPD) Type II was confirmed based on a pathogenic compound heterozygous frameshift variant in the PCNT gene c.5059_5060delAA | p. Asn1687fs (novel variant) and c.9535dup (p. Val3179fs). His parents were found to be heterozygous carriers for the variants. CONCLUSION: We report a novel frameshift variant in the PCNT gene and a previously unreported phenotype for Microcephalic Osteodysplastic Primordial Dwarfism (MOPD) Type II.

A study on knowledge, attitudes and practices regarding dengue fever, its prevention and management among dengue patients presenting to a tertiary care hospital in Sri Lanka.

BACKGROUND: The World Health Organization (WHO) has ranked dengue as one of the top ten threats to Global health in 2019. Sri Lanka faced a massive dengue epidemic in 2017, the largest outbreak in the country during the last three decades, consisting of 186,101 reported cases, and over 320 deaths. The epidemic was controlled by intense measures taken by the health sector. However, the reported dengue cases and dengue deaths in 2019 were significantly higher than that of 2018. Deaths were mostly due to delay in hospitalization of severe dengue patients. The mortality of dengue hemorrhagic fever is 2-5% if detected early and treated promptly, but is high as 20% if left untreated. METHODS: A descriptive cross-sectional study was done among patients with dengue fever presenting to the Sri Jayawardenepura General Hospital during October 2019. Data was collected using a questionnaire comprising 20 questions based on knowledge, attitudes and practices on dengue, which were categorized into questions on awareness of mortality and severity of dengue burden, prevention of dengue vector mosquito breeding and acquiring the infection, patient's role in dengue management, and warning signs requiring prompt hospitalization. RESULTS: The mean KAP score on all questions was 55%, while a majority of 65.2% patients scored moderate KAP scores (50-75%) on all questions, and only 7.6% had high KAP scores (> 75%). The highest categorical mean score of 62% was on awareness of dengue prevention, followed by 54% on awareness of dengue burden, and only 51% on dengue management. Only 5.3% patients scored high scores on awareness of dengue management, followed by 28.5%, and 40.9% patients scoring high scores on awareness of dengue burden, and awareness of prevention of dengue respectively. The mean KAP scores on all questions increased with increasing age category. CONCLUSION: The population relatively has a better awareness of dengue prevention, as compared to awareness of dengue mortality and dengue management. The identified weak point is patient awareness of the patients' role in dengue management, and identifying warning signs requiring prompt hospitalization. This results in delay in treatment, which is a major cause for increased mortality. There was a correlation between those who had good knowledge on dengue burden and those who were aware of patients' role in dengue management. An action plan should be implemented to improve public awareness through education programs on the role of the public and patients in dengue management to drive a better outcome.

A young girl with chronic isolated cervical lymphadenopathy found to have lupus lymphadenopathy, progressing to develop lupus nephritis: a case report.

BACKGROUND: Systemic lupus erythematosus is a rare autoimmune disorder, with the prevalence in Asia ranging from 30 to 50/100,000. The diagnosis of systemic lupus erythematosus is made according to the 2019 European League Against Rheumatism/American College of Rheumatology classification criteria, and it does not contain lymphadenopathy as diagnostic criteria. However, lupus lymphadenopathy has an estimated prevalence of 5-7% at the onset of disease, and 12-15% at any stage of the disease. CASE PRESENTATION: A 19-year-old Sinhalese girl had neck nodules since the age of 5 years, which increased in size and became tender since 1 year. She had alopecia and joint stiffness for 6 months. She presented with a 5-day history of worsening joint pain, fever, and painful, enlarging cervical nodules. She had tender cervical lymphadenopathy, and a vasculitic rash on both lower limbs. She had pancytopenia, an erythrocyte sedimentation rate of 92, positive antinuclear antibody titer, and high anti-double-stranded deoxyribonucleic acid (DNA), with low C3 and C4 complements. She had a high reticulocyte count of 5%, with direct and indirect antiglobulin tests being positive, indicating autoimmune hemolytic anemia. Lymph node biopsy showed moderate reactive follicular hyperplasia, with scattered plasma cells and immunoblasts, with varying degree of coagulative necrosis, suggestive of lupus lymphadenopathy. On immunohistochemistry of the lymph node biopsy, Bcl2 was negative, excluding lymphoma. Contrast-enhanced computed tomography of abdomen and chest was normal with no hepatosplenomegaly or lymphadenopathy. Skin biopsy showed leukocytoclastic vasculitis. Later, with development of generalized edema, she was found to have impaired renal function, and renal biopsy showed lupus nephritis. She was started on hydroxychloroquine, prednisolone, and mycophenolate mofetil, and her symptoms improved and lymphadenopathy regressed. CONCLUSION: In the case of cervical lymphadenopathy in a patient with systemic lupus erythematosus, the possibilities of lupus lymphadenopathy, Kikuchi-Fujimoto disease, and lymphoma should all be considered, after excluding secondary infection due to immunosuppression. Histology confirms the differentiation of these pathologies. It is important to differentiate the cause for lymphadenopathy in systemic lupus erythematosus as the outcome and treatment varies. Lupus lymphadenopathy is usually generalized, but isolated cervical lymphadenopathy could also rarely be the first presentation of systemic lupus erythematosus. Lupus lymphadenopathy can be the only presenting feature, and needs a high index in suspecting systemic lupus erythematosus, though it is not included in the diagnostic criteria.

The complete chloroplast genome of Walla Patta, Gyrinops walla (Thymelaeaceae), an agarwood-producing tree species from Sri Lanka.

Gyrinops walla is an important agarwood-producing tree and threatened species from Sri Lanka. Herein, we assembled and characterized the complete chloroplast (cp) genome of G. walla as a genomic resource for conservation purposes. The 175,130 bp long genome is comprised of 87,376 bp large single-copy (LSC) and 3316 bp small single-copy (SSC) regions, which are separated by two inverted repeat (IR) region, each with a size of 42,291 bp. A total of 140 genes were predicted for the cp genome, which includes 94 protein-coding, 38 tRNA, and eight rRNA genes. Phylogenetic analysis showed that G. walla is fully resolved in a sister position to Aquilaria in the family Thymelaeaceae. The data provided will be useful for study on the molecular phylogenetics and evolution of Thymelaeaceae in the future.

Complicated Dengue Fever and Its Treatment Dilemmas: A Single-Center Experience in Sri Lanka.

Dengue is an arboviral infection that affects humanscausing significant morbidity and mortality in tropical countries. Our first patient who had diabetes presented with shock and was managed as dengue hemorrhagic fever with superadded sepsis which required noradrenalin plus broad-spectrum intravenous antibiotics. The second patient developed severe bradycardia during the ascending limb of the critical phase with hemodynamic stability, which recovered on discharge. Third patient presented with severe and rapid leaking; we used intravenous albumin as an alternative colloid with good outcome. The fourth patient was a pregnant mother at term, and she went into spontaneous labor during the latter half of the critical phase. The fifth patient developed dengue hemorrhagic fever complicated with probable haemophagocytic lymphohistiocytosis. She was treated with intravenous steroids andimmunoglobulin, yet succumbed on day 7. Conclusion. Dengue is an extremely challenging and dynamic disease, which can lead to many unusual complications.A high index of suspicion is key to diagnose and treat promptly.

Magnetic resonance thermometry using a GdIII-based contrast agent.

The complexes described here serve as contrast agents for magnetic resonance imaging thermometry. The complexes differentially enhance contrast between 275 and 325 K. The basis of the temperature response of the fluorinated contrast complex is the modulation of water exchange caused by trifluoromethyl groups that can be chemically controlled.

Unknowing ingestion of Brugmansia suaveolens leaves presenting with signs of anticholinergic toxicity: a case report.

BACKGROUND: Brugmansia suaveolens is the commonest species under the Solanacea ("Angels Trumpet" in English; "Attana" in Sinhalese) plant family in Sri Lanka. It contains alkaloids like scopolamine, atropine and hyoscyamine which can cause an anticholinergic toxindrome. There have been a few reported cases of accidental ingestion of Brugmansia seeds among children, seeds being the most toxic part, but no such reported cases of Brugmansia leaves poisoning among adults. CASE PRESENTATION: A 60-year-old-female Sinhalese presented with acute confusion, delirium, and agitation. She had ingested a herbal drink made from leaves of an unknown plant from her garden prior to onset of symptoms. She had urinary retention, mydriasis and sinus tachycardia. She was managed supportively with activated charcoal and hydration and the delirium completely resolved within 15 hours. The presented unkown plant leaves were identified as Brugmansia suaveolens. CONCLUSION: Although seeds are the most toxic plant part in most cases of Brugmansia poisoning, leaves also have a significant degree of toxicity. It is important that medical professionals promptly recognize the features of anticholinergic syndrome, and have a high index to suspect Brugmansia poisoning and start prompt treatment. It is also important to improve awareness of toxic plants among the general community to prevent toxicities and fatalities.

Evaluation of the accuracy and precision of glucometers currently used in Sri Lanka.

AIMS: Life threatening macrovascular and microvascular complications of diabetes can be minimized by effective glycaemic control. Self monitoring of blood glucose with glucometers is recognized as a cost effective strategy to improve glycaemic control. However accuracy and precision of glucometers will determine the effectiveness of this strategy. We aimed to evaluate accuracy and precision of commonly used glucometers in Sri Lanka. MATERIALS AND METHODS: An observational study was conducted in a tertiary care setting including patients with diabetes and healthy volunteers. Eight commonly used glucometers were used. Blood glucose was measured in 50 participants (16 healthy volunteers, 34 patients with diabetes) in finger prick capillary blood using glucometers and venous blood using standard laboratory methods, and were compared to determine accuracy. Repeated measurements from same glucometer with a single finger prick were made and compared to determine precision. RESULTS: Only one glucometer showed insignificant difference to venous plasma glucose values. Only one glucometer met ADA recommended bias of <5%. None of the glucometers fell within the ISO recommendations for accuracy. CONCLUSION: Majority of commonly used glucometers in Sri Lanka do not meet the ADA recommendations and ISO standards for accuracy and precision. However their variations are unlikely to make significant adverse impact on patient management.

Lean non-alcoholic fatty liver disease (lean NAFLD): characteristics, metabolic outcomes and risk factors from a 7-year prospective, community cohort study from Sri Lanka.

INTRODUCTION: While patients with non-alcoholic fatty liver disease (NAFLD) are mostly overweight or obese, some are lean. METHODS: In a community-based follow-up study (baseline and follow-up surveys performed in 2007 and 2014), we investigated and compared the clinical characteristics, body composition, metabolic associations and outcomes, and other risk factors among individuals with lean (BMI < 23 kg/m2) NAFLD, non-lean (BMI ≥ 23 kg/m2) NAFLD and those without NAFLD. To investigate associations of selected genetic variants, we performed a case-control study between lean NAFLD cases and lean non-NAFLD controls. RESULTS: Of the 2985 participants in 2007, 120 (4.0%) had lean NAFLD and 816 (27.3%) had non-lean NAFLD. 1206 (40.4%) had no evidence of NAFLD (non-NAFLD). Compared to non-lean NAFLD, lean NAFLD was commoner among males (p < 0.001), and had a lower prevalence of hypertension (p < 0.001) and central obesity (WC < 90 cm for males, < 80 cm for females) (p < 0.001) without prominent differences in the prevalence of other metabolic comorbidities at baseline survey. Of 2142 individuals deemed as either NAFLD or non-NAFLD in 2007, 704 NAFLD individuals [84 lean NAFLD, 620 non-lean NAFLD] and 834 individuals with non-NAFLD in 2007 presented for follow-up in 2014. There was no difference in the occurrence of incident metabolic comorbidities between lean NAFLD and non-lean NAFLD. Of 294 individuals who were non-NAFLD in 2007 and lean in both 2007 and 2014, 84 (28.6%) had developed lean NAFLD, giving an annual incidence of 4.1%. Logistic regression identified the presence of diabetes at baseline, increase in weight from baseline to follow-up and a higher educational level as independent risk factors for the development of incident lean NAFLD. NAFLD association of PNPLA3 rs738409 was more pronounced among lean individuals (one-tailed p < 0.05) compared to the whole cohort sample. CONCLUSION: Although lean NAFLD constitutes a small proportion of NAFLD, the risk of developing incident metabolic comorbidities is similar to that of non-lean NAFLD. A PNPLA3 variant showed association with lean NAFLD in the studied population. Therefore, lean NAFLD also warrants careful evaluation and follow-up.

Association between road accidents and low-grade hepatic encephalopathy among Sri Lankan drivers with cirrhosis: a prospective case control study.

BACKGROUND: Low-grade hepatic encephalopathy (LGHE) comprises minimal hepatic encephalopathy (MHE) and grade 1 hepatic encephalopathy. LGHE has no or minimal recognizable symptoms but has mild cognitive and psychomotor deficits. Studies in Western countries have demonstrated increased road accidents (RA) among patients with MHE. Our objective was to investigate the association between Sri Lankan LGHE phenotype and RA. STUDY DESIGN AND METHODS: A prospective, case-control study was conducted in the University Medical Unit, North Colombo Teaching Hospital, Ragama Sri Lanka. Patients with cirrhosis of any aetiology, without OHE, who had been driving during previous 1 month were included. A similar number of age matched, healthy control drivers were also enrolled. Both groups were subjected to five pencil-paper based psychometric tests used to detect LGHE in cirrhotics. Self-reported RA during the previous 1 month were recorded: categorized as 'major' when resulted in hospitalization of the involved, 'minor' when there were injuries, but not serious enough for hospitalization of the involved and 'other' when limited to damages to vehicle or environment without injuries. RESULTS: Among 55 drivers with cirrhosis and LGHE [males, median age 53 years (range 30-60)], 7 (12.7 %) reported RA compared to 6 (10.9 %) among 55 controls [males; median age 51 years (range 30-60)]. There were no 'major' accidents in either group. 2/55 (3.6 %) cases and 2/55 (3.6 %) controls reported 'minor' accidents. CONCLUSION: There was no increased frequency of RA among Sri Lankan drivers with LGHE compared to healthy controls. This is with the limitation of the study based only on self reported RA.

A novel reverse transcriptase-polymerase chain reaction based-liquid hybridisation (RT-PCR-LH) assay for early diagnosis of dengue infection.

BACKGROUND: Early definitive laboratory diagnosis of dengue is difficult with the tests in routine use at present. OBJECTIVE: To develop a reverse transcriptase-polymerase chain reaction based liquid hybridisation (RT-PCR-LH) technique for the rapid and early diagnosis of dengue. RESEARCH DESIGN: RT-PCR products of the NS3 gene of dengue virus prototypes and of a few positive sera for dengue virus by culture, were allowed to hybridise in liquid phase with a mixture of dengue specific radiolabelled oligonucleotides. The products were separated by PAGE and visualised by autoradiography. 78 suspected dengue sera were also tested by RT-PCR-LH method, and by IgM-ELISA and HAI tests, for comparison. RESULTS: Two DNA bands (approximately equal to 470 bp and approximately equal to 455 bp) specific to dengue virus, were observed. RT-PCR-LH assay takes only 24 h. Of the 78 suspected dengue acute sera tested, 45/78 were positive by RT-PCR-LH, 31/78 were positive by IgM-ELISA, and 14/78 had a HAI titre > or = 2560. Duration of fever was known in 72 cases, and infection was detected by RT-PCR-LH in 11/22 of cases with < 5 d fever and by IgM-ELISA in 1/22. In cases with 5 to 15 d fever RT-PCR-LH and IgM-ELISA/HAI titre > or = 2560 detected infection in 30/50 and 27/50 respectively. The 10 sera which were negative by RT-PCR-LH, but were positive by either IgM-ELISA or HAI titre > or = 2560 were all > 5 d fever cases. RT-PCR-LH together with IgM-ELISA were capable of detecting dengue infection in 56/78 of the suspected cases. CONCLUSION: RT-PCR-LH assay developed in this study appears to have an advantage over other diagnostic techniques for the early detection of dengue.