MyMedR

Displaying publications 1 - 20 of 41 in total

Abstract:

Sort:

Differences in serum potassium concentrations between Chinese, Indians and Malays

Hawkins RC

Clin Chem Lab Med, 2010;48(1):105-8.
PMID: 19929751 DOI: 10.1515/CCLM.2010.010

It has been suggested that potassium concentrations may vary between different geographical regions, possibly reflecting ethnic differences in potassium status. This study compared the serum potassium concentrations of three Asian ethnicities in a single geographical location.
Differences in serum creatinine concentration between Caucasians, Chinese, Indians and Malays

Hawkins RC

Clin Chim Acta, 2010 Sep 6;411(17-18):1393.
PMID: 20580697 DOI: 10.1016/j.cca.2010.05.027
Fulltext Dietary and lifestyle changes of Malaysian breast cancer survivors: a qualitative study

Redhwan, A.A., Md Idris, M.N., Robert, C.

Malaysian Journal of Community Health, 2008;14(1):24-31.
MyJurnal

Objective :This study was performed to determine changes in diet and lifestyle among breast cancer survivors in Malaysia.
Methods :This was a qualitative study done on fifteen survivors (8 Malays and 7 non-Malays) obtained from the Oncology and Surgery Department, National University of Malaysia Hospital. The study was conducted using a semi-structured interview format. The data obtained were sorted into various categories via content analysis.
Results :Majority of breast cancer survivors increased their fruit and vegetable intake following diagnosis. Some non-Malays changed to vegetarian whereas all the Malays remained on the same dietary pattern. As far as exercise was concerned, all Malays did not exercise before diagnosis, but did so after diagnosis, whereas most of non- Malays did not exercise either before or after diagnosis.
Conclusion : Some changes were noticed in dietary and lifestyle behaviors after diagnosis among some survivors. The differences were due to their different cultural and religious backgrounds.
Fulltext The differences between the quality of life of Malays and non-Malays breast cancer survivors women from a teaching hospital, Kuala Lumpur: a qualitative study

Redhwan, A.A., Idris, M.N., Fuad, I., Hairol, O., Robert, C.

Malaysian Journal of Community Health, 2009;15(2):98-105.
MyJurnal

Introduction : The purpose of this study is to explore the differences of quality of life (QOL) of Malay and non-Malay breast cancer survivors using qualitative method.
Methods : Data was collected using in-depth face to face interview. List of the patients were obtained from Oncology & Surgery Departments and contact numbers were obtained from the medical record. The interviews were conducted either in their home or in the hospital after the appointment has been made.
Results : The majority of the Malays were unable to fulfill the needs of their families. However, the non-Malays were able to fulfill the needs of their families. The majority were satisfied with social interaction and the relationships with their families and friends. In terms of feelings, most survivors felt sad, angry and sometimes they feel like they were going to die early. However the majority coped well with their illness. Regarding sleep, all Malays did not have any sleeping problems, but most of the non-Malays reported serious problems. All survivors were worried about the other female members of the family of getting the same illness. Most survivors did not have any problems with altered body image.
Conclusion : Malays did not have any sleeping problems, but most of the non-Malays reported serious problems. However, the majority of survivors coped well with their illnesses.
Fulltext Quality of life among women with breast cancer from Universiti Kebangsaan Malaysia Medical Centre, Malaysia

Redhwan, A.A., Md Idris, M.N., Zaleha, M.I., Robert, C., Fuad, I., Sami, R.A.

Malaysian Journal of Community Health, 2008;14(2):46-55.
MyJurnal

Introduction : The purpose of this study was to determine the quality of life (QOL) of breast cancer survivors based on socio-demographic and clinical characteristics.
Methods : A cross-sectional study was performed on 125 breast cancer survivors from the outpatient clinics. FACT-B (Functional Assessment of Cancer Therapy-Breast) questionnaire was used to assess survivors’ QOL.
Results : Survivors with low body mass index (BMI) (underweight) were found to have the lowest overall QOL. Those who were overweight had a higher overall QOL, and those who were normal-weight had the highest QOL. Low educational level, being underweight and low monthly household income were significantly associated with lower overall QOL Tamoxifen use and employment status were significantly associated with QOL in some domains. Time since diagnosis to QOL interview was significantly associated with greater scores in emotional well-being (EWB). Multiple linear regression indicated that age, marital status, monthly household income, surgery and histological grade were indicative of the patients QOL.
Conclusion : The four primary factors related to better QOL were high educational level, high income, normal body weight and greater duration from the time of diagnosis to the time of interview. Age, marital status, income, lumpectomy and histological grade were indicative of the patient QOL.
Study site: Oncology and Surgical clinics; Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
Fulltext Carbon stocks and fluxes in tropical lowland dipterocarp rainforests in Sabah, Malaysian Borneo

Saner P, Loh YY, Ong RC, Hector A

PLoS One, 2012;7(1):e29642.
PMID: 22235319 DOI: 10.1371/journal.pone.0029642

Deforestation in the tropics is an important source of carbon C release to the atmosphere. To provide a sound scientific base for efforts taken to reduce emissions from deforestation and degradation (REDD+) good estimates of C stocks and fluxes are important. We present components of the C balance for selectively logged lowland tropical dipterocarp rainforest in the Malua Forest Reserve of Sabah, Malaysian Borneo. Total organic C in this area was 167.9 Mg C ha⁻¹±3.8 (SD), including: Total aboveground (TAGC: 55%; 91.9 Mg C ha⁻¹±2.9 SEM) and belowground carbon in trees (TBGC: 10%; 16.5 Mg C ha⁻¹±0.5 SEM), deadwood (8%; 13.2 Mg C ha⁻¹±3.5 SEM) and soil organic matter (SOM: 24%; 39.6 Mg C ha⁻¹±0.9 SEM), understory vegetation (3%; 5.1 Mg C ha⁻¹±1.7 SEM), standing litter (<1%; 0.7 Mg C ha⁻¹±0.1 SEM) and fine root biomass (<1%; 0.9 Mg C ha⁻¹±0.1 SEM). Fluxes included litterfall, a proxy for leaf net primary productivity (4.9 Mg C ha⁻¹ yr⁻¹±0.1 SEM), and soil respiration, a measure for heterotrophic ecosystem respiration (28.6 Mg C ha⁻¹ yr⁻¹±1.2 SEM). The missing estimates necessary to close the C balance are wood net primary productivity and autotrophic respiration.Twenty-two years after logging TAGC stocks were 28% lower compared to unlogged forest (128 Mg C ha⁻¹±13.4 SEM); a combined weighted average mean reduction due to selective logging of -57.8 Mg C ha⁻¹ (with 95% CI -75.5 to -40.2). Based on the findings we conclude that selective logging decreased the dipterocarp stock by 55-66%. Silvicultural treatments may have the potential to accelerate the recovery of dipterocarp C stocks to pre-logging levels.
Fulltext Fungi and insects compensate for lost vertebrate seed predation in an experimentally defaunated tropical forest

Williams PJ, Ong RC, Brodie JF, Luskin MS

Nat Commun, 2021 Mar 12;12(1):1650.
PMID: 33712621 DOI: 10.1038/s41467-021-21978-8

Overhunting reduces important plant-animal interactions such as vertebrate seed dispersal and seed predation, thereby altering plant regeneration and even above-ground biomass. It remains unclear, however, if non-hunted species can compensate for lost vertebrates in defaunated ecosystems. We use a nested exclusion experiment to isolate the effects of different seed enemies in a Bornean rainforest. In four of five tree species, vertebrates kill many seeds (13-66%). Nonetheless, when large mammals are excluded, seed mortality from insects and fungi fully compensates for the lost vertebrate predation, such that defaunation has no effect on seedling establishment. The switch from seed predation by generalist vertebrates to specialist insects and fungi in defaunated systems may alter Janzen-Connell effects and density-dependence in plants. Previous work using simulation models to explore how lost seed dispersal will affect tree species composition and carbon storage may require reevaluation in the context of functional redundancy within complex species interactions networks.
IgG4 related orbit disease - An unusual cause of an orbital mass

Chidambaram VA, Anita CSY, Robert C, Garry C

Med J Malaysia, 2018 12;73(6):415-417.
PMID: 30647218

IgG4-related disease is a newly described systemic autoimmune and allergic disease, characterized histologically by a fibroinflammatory response with IgG4 plasma cells. It was initially described as affecting the pancreas, but commonly involves the head and neck region as well. While a biopsy is essential for definitive diagnosis, cross sectional imaging may be the initial modality which may suggest this entity. We describe a case of pathologically proven IgG4 related disease which highlights some key radiologic features seen in this entity. Our case highlights some key radiological features of IgG4- related disease in the head and neck, with involvement of the lacrimal glands, pituitary gland and cranial nerves on CT.
Fulltext Linking Ayurveda and Western medicine by integrative analysis

Fauzi FM, Koutsoukas A, Lowe R, Joshi K, Fan TP, Glen RC, et al.

J Ayurveda Integr Med, 2013 Apr;4(2):117-9.
PMID: 23930045 DOI: 10.4103/0975-9476.113882

In this article, we discuss our recent work in elucidating the mode-of-action of compounds used in traditional medicine including Ayurvedic medicine. Using computational ('in silico') approach, we predict potential targets for Ayurvedic anti-cancer compounds, obtained from the Indian Plant Anticancer Database given its chemical structure. In our analysis, we observed that: (i) the targets predicted can be connected to cancer pathogenesis i.e. steroid-5-alpha reductase 1 and 2 and estrogen receptor-β, and (ii) predominantly hormone-dependent cancer targets were predicted for the anti-cancer compounds. Through the use of our in silico target prediction, we conclude that understanding how traditional medicine such as Ayurveda work through linking with the 'western' understanding of chemistry and protein targets can be a fruitful avenue in addition to bridging the gap between the two different schools of thinking. Given that compounds used in Ayurveda have been tested and used for thousands of years (although not in the same approach as Western medicine), they can potentially be developed into potential new drugs. Hence, to further advance the case of Ayurvedic medicine, we put forward some suggestions namely: (a) employing and integrating novel analytical methods given the advancements of 'omics' and (b) sharing experimental data and clinical results on studies done on Ayurvedic compounds in an easy and accessible way.
Fulltext The interplay of climate, intervention and imported cases as determinants of the 2014 dengue outbreak in Guangzhou

Cheng Q, Jing Q, Spear RC, Marshall JM, Yang Z, Gong P

PLoS Negl Trop Dis, 2017 Jun;11(6):e0005701.
PMID: 28640895 DOI: 10.1371/journal.pntd.0005701

Dengue is a fast spreading mosquito-borne disease that affects more than half of the population worldwide. An unprecedented outbreak happened in Guangzhou, China in 2014, which contributed 52 percent of all dengue cases that occurred in mainland China between 1990 and 2015. Our previous analysis, based on a deterministic model, concluded that the early timing of the first imported case that triggered local transmission and the excessive rainfall thereafter were the most important determinants of the large final epidemic size in 2014. However, the deterministic model did not allow us to explore the driving force of the early local transmission. Here, we expand the model to include stochastic elements and calculate the successful invasion rate of cases that entered Guangzhou at different times under different climate and intervention scenarios. The conclusion is that the higher number of imported cases in May and June was responsible for the early outbreak instead of climate. Although the excessive rainfall in 2014 did increase the success rate, this effect was offset by the low initial water level caused by interventions in late 2013. The success rate is strongly dependent on mosquito abundance during the recovery period of the imported case, since the first step of a successful invasion is infecting at least one local mosquito. The average final epidemic size of successful invasion decreases exponentially with introduction time, which means if an imported case in early summer initiates the infection process, the final number infected can be extremely large. Therefore, dengue outbreaks occurring in Thailand, Singapore, Malaysia and Vietnam in early summer merit greater attention, since the travel volumes between Guangzhou and these countries are large. As the climate changes, destroying mosquito breeding sites in Guangzhou can mitigate the detrimental effects of the probable increase in rainfall in spring and summer.
Fulltext Perceptions about food allergy among medical science students in a university in Shah Alam, Selangor, Malaysia

Redhwan AA, Low WY, Mustafa FM, Robert C, Ali A

International Food Research Journal, 2011;18(1):451-458.
MyJurnal

This study aimed to determine the perceptions and opinions of medical students about food allergy. Universal sampling was used to conduct focus group discussions. The majority of the participants 40 (67%) mentioned that the common symptoms of food allergy are: skin rashes, swollen lips, diarrhea, vomiting, bronchospasm, redness, itchiness, difficulty in breathing, stomach ache and fever. Majority of participants mentioned that seafood is the food that can cause most food allergies 52 (87%), followed by tree nuts 25 (42%), peanuts and dairy products 19 (32%). Regarding the most allergenic food named by the participants are seafood 23 (38%); followed by milk and dairy products 5 (8%) and nuts 5 (8%). The majority of participants mentioned that food allergy can be fatal 48 (80%), a child can catch food allergy 57 (95%), and 10 of 100 people would have food allergy 31 (52%). Half of the participants 30 (50%) mentioned that it is very hard to care for children with food allergy. The majority of participants mentioned that food allergies do run in families 50 (83%), avoiding allergenic food is the best preventive methods 36 (60%) and that food allergy can be treated and will go away and 32 (53%). This study showed that in spite of sufficient knowledge among medical students about food allergy, some misconceptions still exist such as the high prevalence of food allergy and that food allergy can be treated and will go away. Therefore, there is a need for improving the continuous medical education among medical students with regard to food allergy because they are our future physicians.
Fulltext Co-benefits of sustainable forest management in biodiversity conservation and carbon sequestration

Imai N, Samejima H, Langner A, Ong RC, Kita S, Titin J, et al.

PLoS One, 2009;4(12):e8267.
PMID: 20011516 DOI: 10.1371/journal.pone.0008267

Sustainable forest management (SFM), which has been recently introduced to tropical natural production forests, is beneficial in maintaining timber resources, but information about the co-benefits for biodiversity conservation and carbon sequestration is currently lacking.
Influence of Genotype on Warfarin Maintenance Dose Predictions Produced Using a Bayesian Dose Individualization Tool

Saffian SM, Duffull SB, Roberts RL, Tait RC, Black L, Lund KA, et al.

Ther Drug Monit, 2016 12;38(6):677-683.
PMID: 27855133

BACKGROUND: A previously established Bayesian dosing tool for warfarin was found to produce biased maintenance dose predictions. In this study, we aimed (1) to determine whether the biased warfarin dose predictions previously observed could be replicated in a new cohort of patients from 2 different clinical settings, (2) to explore the influence of CYP2C9 and VKORC1 genotype on predictive performance of the Bayesian dosing tool, and (3) to determine whether the previous population used to develop the kinetic-pharmacodynamic model underpinning the Bayesian dosing tool was sufficiently different from the test (posterior) population to account for the biased dose predictions.
METHODS: The warfarin maintenance doses for 140 patients were predicted using the dosing tool and compared with the observed maintenance dose. The impact of genotype was assessed by predicting maintenance doses with prior parameter values known to be altered by genetic variability (eg, EC50 for VKORC1 genotype). The prior population was evaluated by fitting the published kinetic-pharmacodynamic model, which underpins the Bayesian tool, to the observed data using NONMEM and comparing the model parameter estimates with published values.
RESULTS: The Bayesian tool produced positively biased dose predictions in the new cohort of patients (mean prediction error [95% confidence interval]; 0.32 mg/d [0.14-0.5]). The bias was only observed in patients requiring ≥7 mg/d. The direction and magnitude of the observed bias was not influenced by genotype. The prior model provided a good fit to our data, which suggests that the bias was not caused by different prior and posterior populations.
CONCLUSIONS: Maintenance doses for patients requiring ≥7 mg/d were overpredicted. The bias was not due to the influence of genotype nor was it related to differences between the prior and posterior populations. There is a need for a more mechanistic model that captures warfarin dose-response relationship at higher warfarin doses.
Fulltext CCoAOMT Down-Regulation Activates Anthocyanin Biosynthesis in Petunia

Shaipulah NF, Muhlemann JK, Woodworth BD, Van Moerkercke A, Verdonk JC, Ramirez AA, et al.

Plant Physiol, 2016 Feb;170(2):717-31.
PMID: 26620524 DOI: 10.1104/pp.15.01646

Anthocyanins and volatile phenylpropenes (isoeugenol and eugenol) in petunia (Petunia hybrida) flowers have the precursor 4-coumaryl coenzyme A (CoA) in common. These phenolics are produced at different stages during flower development. Anthocyanins are synthesized during early stages of flower development and sequestered in vacuoles during the lifespan of the flowers. The production of isoeugenol and eugenol starts when flowers open and peaks after anthesis. To elucidate additional biochemical steps toward (iso)eugenol production, we cloned and characterized a caffeoyl-coenzyme A O-methyltransferase (PhCCoAOMT1) from the petals of the fragrant petunia 'Mitchell'. Recombinant PhCCoAOMT1 indeed catalyzed the methylation of caffeoyl-CoA to produce feruloyl CoA. Silencing of PhCCoAOMT1 resulted in a reduction of eugenol production but not of isoeugenol. Unexpectedly, the transgenic plants had purple-colored leaves and pink flowers, despite the fact that cv Mitchell lacks the functional R2R3-MYB master regulator ANTHOCYANIN2 and has normally white flowers. Our results indicate that down-regulation of PhCCoAOMT1 activated the anthocyanin pathway through the R2R3-MYBs PURPLE HAZE (PHZ) and DEEP PURPLE, with predominantly petunidin accumulating. Feeding cv Mitchell flowers with caffeic acid induced PHZ expression, suggesting that the metabolic perturbation of the phenylpropanoid pathway underlies the activation of the anthocyanin pathway. Our results demonstrate a role for PhCCoAOMT1 in phenylpropene production and reveal a link between PhCCoAOMT1 and anthocyanin production.
Fulltext Long-term outcomes in leadless Micra transcatheter pacemakers with elevated thresholds at implantation: Results from the Micra Transcatheter Pacing System Global Clinical Trial

Piccini JP, Stromberg K, Jackson KP, Laager V, Duray GZ, El-Chami M, et al.

Heart Rhythm, 2017 05;14(5):685-691.
PMID: 28111349 DOI: 10.1016/j.hrthm.2017.01.026

BACKGROUND: Device repositioning during Micra leadless pacemaker implantation may be required to achieve optimal pacing thresholds.
OBJECTIVE: The purpose of this study was to describe the natural history of acute elevated Micra vs traditional transvenous lead thresholds.
METHODS: Micra study VVI patients with threshold data (at 0.24 ms) at implant (n = 711) were compared with Capture study patients with de novo transvenous leads at 0.4 ms (n = 538). In both cohorts, high thresholds were defined as >1.0 V and very high as >1.5 V. Change in pacing threshold (0-6 months) with high (1.0 to ≤1.5 V) or very high (>1.5 V) thresholds were compared using the Wilcoxon signed-rank test.
RESULTS: Of the 711 Micra patients, 83 (11.7%) had an implant threshold of >1.0 V at 0.24 ms. Of the 538 Capture patients, 50 (9.3%) had an implant threshold of >1.0 V at 0.40 ms. There were no significant differences in patient characteristics between those with and without an implant threshold of >1.0 V, with the exception of left ventricular ejection fraction in the Capture cohort (high vs low thresholds, 53% vs 58%; P = .011). Patients with an implant threshold of >1.0 V decreased significantly (P < .001) in both cohorts. Micra patients with high and very high thresholds decreased significantly (P < .01) by 1 month, with 87% and 85% having 6-month thresholds lower than the implant value. However, when the capture threshold at implant was >2 V, only 18.2% had a threshold of ≤1 V at 6 months and 45.5% had a capture threshold of >2 V.
CONCLUSIONS: Pacing thresholds in most Micra patients with elevated thresholds decrease after implant. Micra device repositioning may not be necessary if the pacing threshold is ≤2 V.
Patient selection, pacing indications, and subsequent outcomes with de novo leadless single-chamber VVI pacing

Piccini JP, Stromberg K, Jackson KP, Kowal RC, Duray GZ, El-Chami MF, et al.

Europace, 2019 Nov 01;21(11):1686-1693.
PMID: 31681964 DOI: 10.1093/europace/euz230

AIMS: Patient selection is a key component of securing optimal patient outcomes with leadless pacing. We sought to describe and compare patient characteristics and outcomes of Micra patients with and without a primary pacing indication associated with atrial fibrillation (AF) in the Micra IDE trial.
METHODS AND RESULTS: The primary outcome (risk of cardiac failure, pacemaker syndrome, or syncope related to the Micra system or procedure) was compared between successfully implanted patients from the Micra IDE trial with a primary pacing indication associated with AF or history of AF (AF group) and those without (non-AF group). Among 720 patients successfully implanted with Micra, 228 (31.7%) were in the non-AF group. Reasons for selecting VVI pacing in non-AF patients included an expectation for infrequent pacing (66.2%) and advanced age (27.2%). More patients in the non-AF group had a condition that precluded the use of a transvenous pacemaker (9.6% vs. 4.7%, P = 0.013). Atrial fibrillation patients programmed to VVI received significantly more ventricular pacing compared to non-AF patients (median 67.8% vs. 12.6%; P
The value of biodiversity for the functioning of tropical forests: insurance effects during the first decade of the Sabah biodiversity experiment

Tuck SL, O'Brien MJ, Philipson CD, Saner P, Tanadini M, Dzulkifli D, et al.

Proc Biol Sci, 2016 Dec 14;283(1844).
PMID: 27928046

One of the main environmental threats in the tropics is selective logging, which has degraded large areas of forest. In southeast Asia, enrichment planting with seedlings of the dominant group of dipterocarp tree species aims to accelerate restoration of forest structure and functioning. The role of tree diversity in forest restoration is still unclear, but the 'insurance hypothesis' predicts that in temporally and spatially varying environments planting mixtures may stabilize functioning owing to differences in species traits and ecologies. To test for potential insurance effects, we analyse the patterns of seedling mortality and growth in monoculture and mixture plots over the first decade of the Sabah biodiversity experiment. Our results reveal the species differences required for potential insurance effects including a trade-off in which species with denser wood have lower growth rates but higher survival. This trade-off was consistent over time during the first decade, but growth and mortality varied spatially across our 500 ha experiment with species responding to changing conditions in different ways. Overall, average survival rates were extreme in monocultures than mixtures consistent with a potential insurance effect in which monocultures of poorly surviving species risk recruitment failure, whereas monocultures of species with high survival have rates of self-thinning that are potentially wasteful when seedling stocks are limited. Longer-term monitoring as species interactions strengthen will be needed to more comprehensively test to what degree mixtures of species spread risk and use limited seedling stocks more efficiently to increase diversity and restore ecosystem structure and functioning.
Menstrual and Reproductive Factors, Hormone Use, and Risk of Pancreatic Cancer: Analysis From the International Pancreatic Cancer Case-Control Consortium (PanC4)

Lujan-Barroso L, Zhang W, Olson SH, Gao YT, Yu H, Baghurst PA, et al.

Pancreas, 2016 11;45(10):1401-1410.
PMID: 27088489

OBJECTIVES: We aimed to evaluate the relation between menstrual and reproductive factors, exogenous hormones, and risk of pancreatic cancer (PC).
METHODS: Eleven case-control studies within the International Pancreatic Cancer Case-control Consortium took part in the present study, including in total 2838 case and 4748 control women. Pooled estimates of odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated using a 2-step logistic regression model and adjusting for relevant covariates.
RESULTS: An inverse OR was observed in women who reported having had hysterectomy (ORyesvs.no, 0.78; 95% CI, 0.67-0.91), remaining significant in postmenopausal women and never-smoking women, adjusted for potential PC confounders. A mutually adjusted model with the joint effect for hormone replacement therapy (HRT) and hysterectomy showed significant inverse associations with PC in women who reported having had hysterectomy with HRT use (OR, 0.64; 95% CI, 0.48-0.84).
CONCLUSIONS: Our large pooled analysis suggests that women who have had a hysterectomy may have reduced risk of PC. However, we cannot rule out that the reduced risk could be due to factors or indications for having had a hysterectomy. Further investigation of risk according to HRT use and reason for hysterectomy may be necessary.
Fulltext Existing and potential infection risk zones of yellow fever worldwide: a modelling analysis

Shearer FM, Longbottom J, Browne AJ, Pigott DM, Brady OJ, Kraemer MUG, et al.

Lancet Glob Health, 2018 03;6(3):e270-e278.
PMID: 29398634 DOI: 10.1016/S2214-109X(18)30024-X

BACKGROUND: Yellow fever cases are under-reported and the exact distribution of the disease is unknown. An effective vaccine is available but more information is needed about which populations within risk zones should be targeted to implement interventions. Substantial outbreaks of yellow fever in Angola, Democratic Republic of the Congo, and Brazil, coupled with the global expansion of the range of its main urban vector, Aedes aegypti, suggest that yellow fever has the propensity to spread further internationally. The aim of this study was to estimate the disease's contemporary distribution and potential for spread into new areas to help inform optimal control and prevention strategies.
METHODS: We assembled 1155 geographical records of yellow fever virus infection in people from 1970 to 2016. We used a Poisson point process boosted regression tree model that explicitly incorporated environmental and biological explanatory covariates, vaccination coverage, and spatial variability in disease reporting rates to predict the relative risk of apparent yellow fever virus infection at a 5 × 5 km resolution across all risk zones (47 countries across the Americas and Africa). We also used the fitted model to predict the receptivity of areas outside at-risk zones to the introduction or reintroduction of yellow fever transmission. By use of previously published estimates of annual national case numbers, we used the model to map subnational variation in incidence of yellow fever across at-risk countries and to estimate the number of cases averted by vaccination worldwide.
FINDINGS: Substantial international and subnational spatial variation exists in relative risk and incidence of yellow fever as well as varied success of vaccination in reducing incidence in several high-risk regions, including Brazil, Cameroon, and Togo. Areas with the highest predicted average annual case numbers include large parts of Nigeria, the Democratic Republic of the Congo, and South Sudan, where vaccination coverage in 2016 was estimated to be substantially less than the recommended threshold to prevent outbreaks. Overall, we estimated that vaccination coverage levels achieved by 2016 avert between 94 336 and 118 500 cases of yellow fever annually within risk zones, on the basis of conservative and optimistic vaccination scenarios. The areas outside at-risk regions with predicted high receptivity to yellow fever transmission (eg, parts of Malaysia, Indonesia, and Thailand) were less extensive than the distribution of the main urban vector, A aegypti, with low receptivity to yellow fever transmission in southern China, where A aegypti is known to occur.
INTERPRETATION: Our results provide the evidence base for targeting vaccination campaigns within risk zones, as well as emphasising their high effectiveness. Our study highlights areas where public health authorities should be most vigilant for potential spread or importation events.
FUNDING: Bill & Melinda Gates Foundation.
Fulltext Mechanisms of environmental chemicals that enable the cancer hallmark of evasion of growth suppression

Nahta R, Al-Mulla F, Al-Temaimi R, Amedei A, Andrade-Vieira R, Bay SN, et al.

Carcinogenesis, 2015 Jun;36 Suppl 1:S2-18.
PMID: 26106139 DOI: 10.1093/carcin/bgv028

As part of the Halifax Project, this review brings attention to the potential effects of environmental chemicals on important molecular and cellular regulators of the cancer hallmark of evading growth suppression. Specifically, we review the mechanisms by which cancer cells escape the growth-inhibitory signals of p53, retinoblastoma protein, transforming growth factor-beta, gap junctions and contact inhibition. We discuss the effects of selected environmental chemicals on these mechanisms of growth inhibition and cross-reference the effects of these chemicals in other classical cancer hallmarks.

Filters

Please provide feedback to Administrator ([email protected])

External Links