A Novel Ex Vivo Tumor Spheroid-Tissue Model for Investigating Microvascular Remodeling and Lymphatic Blood Vessel Plasticity.

Biomimetic tumor microenvironment models bridge the gap between in vitro and in vivo systems and serve as a useful way to address the modeling challenge of how to recreate the cell and system complexity associated with real tissues. Our laboratory has developed an ex vivo rat mesentery culture model, which allows for simultaneous investigation of blood and lymphatic microvascular network remodeling in an intact tissue environment. Given that angiogenesis and lymphangiogenesis are key contributors to the progression of cancer, the objective of this study was to combine tissue and tumor spheroid culture methods to establish a novel ex vivo tumor spheroid-tissue model by verifying its use for evaluating the effects of cancer cell behavior on the local microvascular environment. H1299 or A549 tumor spheroids were formed via hanging drop culture and seeded onto rat mesenteric tissues harvested from adult male Wistar rats. Tissues with transplanted spheroids were cultured in serum-free media for 3 to 5 days. PECAM, NG2, CD11b, and αSMA labeling identified endothelial cells, pericytes, immune cells, and smooth muscle cells, respectively. Time-lapse imaging confirmed cancer cell type specific migration. In addition to increasing PECAM positive capillary sprouting and LYVE-1 positive endothelial cell extensions indicative of lymphangiogenesis, tumor spheroid presence induced the formation of lymphatic/blood vessel connections and the formation of hybrid, mosaic vessels that were characterized by discontinuous LYVE-1 labeling. The results support the application of a novel tumor spheroid microenvironment model for investigating cancer cell-microvascular interactions.

Evaluating the performance of polygenic risk profiling across diverse ancestry populations in Parkinson's disease.

Objective: This study aims to address disparities in risk prediction by evaluating the performance of polygenic risk score (PRS) models using the 90 risk variants across 78 independent loci previously linked to Parkinson's disease (PD) risk across seven diverse ancestry populations. Methods: We conducted a multi-stage study, testing PRS models in predicting PD status across seven different ancestries applying three approaches: 1) PRS adjusted by gender and age; 2) PRS adjusted by gender, age and principal components (PCs); and 3) PRS adjusted by gender, age and percentage of population admixture. These models were built using the largest four population-specific summary statistics of PD risk to date (base data) and individual level data obtained from the Global Parkinson's Genetics Program (target data). We performed power calculations to estimate the minimum sample size required to conduct these analyses. A total of 91 PRS models were developed to investigate cumulative known genetic variation associated with PD risk and age of onset in a global context. Results: We observed marked heterogeneity in risk estimates across non-European ancestries, including East Asians, Central Asians, Latino/Admixed Americans, Africans, African admixed, and Ashkenazi Jewish populations. Risk allele patterns for the 90 risk variants yielded significant differences in directionality, frequency, and magnitude of effect. PRS did not improve in performance when predicting disease status using similar base and target data across multiple ancestries, demonstrating that cumulative PRS models based on current known risk are inherently biased towards European populations. We found that PRS models adjusted by percentage of admixture outperformed models that adjusted for conventional PCs in highly admixed populations. Overall, the clinical utility of our models in individually predicting PD status is limited in concordance with the estimates observed in European populations. Interpretation: This study represents the first comprehensive assessment of how PRS models predict PD risk and age at onset in a multi-ancestry fashion. Given the heterogeneity and distinct genetic architecture of PD across different populations, our assessment emphasizes the need for larger and diverse study cohorts of individual-level target data and well-powered ancestry-specific summary statistics. Our current understanding of PD status unraveled through GWAS in European populations is not generally applicable to other ancestries. Future studies should integrate clinical and *omics level data to enhance the accuracy and predictive power of PRS across diverse populations.

Lymphatic/blood vessel plasticity: motivation for a future research area based on present and past observations.

The lymphatic system plays a significant role in homeostasis and drainage of excess fluid back into venous circulation. Lymphatics are also associated with a number of diseases including lymphedema, tumor metastasis, and various lymphatic malformations. Emerging evidence suggests that lymphatics might have a bigger connection to the blood vascular system than originally presumed. As these two systems are often studied in isolation, several knowledge gaps exist surrounding what constitutes lymphatic vascular plasticity, under what conditions it arises, and where structures characteristic of plasticity can form. The objective of this review is to overview current structural, cell lineage-based, and cell identity-based evidence for lymphatic plasticity. These examples of plasticity will then be considered in the context of potential clinical and surgical implications of this evolving research area. This review details our current understanding of lymphatic plasticity, highlights key unanswered questions in the field, and motivates future research aimed at clarifying the role and therapeutic potential of lymphatic plasticity in disease.

The Microvascular-Lymphatic Interface and Tissue Homeostasis: Critical Questions That Challenge Current Understanding.

Lymphatic and blood microvascular networks play critical roles in the clearance of excess fluid from local tissue spaces. Given the importance of these dynamics in inflammation, tumor metastasis, and lymphedema, understanding the coordinated function and remodeling between lymphatic and blood vessels in adult tissues is necessary. Knowledge gaps exist because the functions of these two systems are typically considered separately. The objective of this review was to highlight the coordinated functional relationships between blood and lymphatic vessels in adult microvascular networks. Structural, functional, temporal, and spatial relationships will be framed in the context of maintaining tissue homeostasis, vessel permeability, and system remodeling. The integration across systems will emphasize the influence of the local environment on cellular and molecular dynamics involved in fluid flow from blood capillaries to initial lymphatic vessels in microvascular networks.

A Challenge for Engineering Biomimetic Microvascular Models: How do we Incorporate the Physiology?

The gap between in vitro and in vivo assays has inspired biomimetic model development. Tissue engineered models that attempt to mimic the complexity of microvascular networks have emerged as tools for investigating cell-cell and cell-environment interactions that may be not easily viewed in vivo. A key challenge in model development, however, is determining how to recreate the multi-cell/system functional complexity of a real network environment that integrates endothelial cells, smooth muscle cells, vascular pericytes, lymphatics, nerves, fluid flow, extracellular matrix, and inflammatory cells. The objective of this mini-review is to overview the recent evolution of popular biomimetic modeling approaches for investigating microvascular dynamics. A specific focus will highlight the engineering design requirements needed to match physiological function and the potential for top-down tissue culture methods that maintain complexity. Overall, examples of physiological validation, basic science discoveries, and therapeutic evaluation studies will emphasize the value of tissue culture models and biomimetic model development approaches that fill the gap between in vitro and in vivo assays and guide how vascular biologists and physiologists might think about the microcirculation.

A Novel ex vivo Method for Investigating Vascularization of Transplanted Islets.

Revascularization of transplanted pancreatic islets is critical for survival and treatment of type 1 diabetes. Questions concerning how islets influence local microvascular networks and how networks form connections with islets remain understudied and motivate the need for new models that mimic the complexity of real tissue. Recently, our laboratory established the rat mesentery culture model as a tool to investigate cell dynamics involved in microvascular growth. An advantage is the ability to observe blood vessels, lymphatics, and immune cells. The objective of this study was to establish the rat mesentery tissue culture model as a useful tool to investigate islet tissue integration. DiI-labeled islets were seeded onto adult rat mesentery tissues and cultured for up to 3 days. Live lectin labeling enabled time-lapse observation of vessel growth. During culture, DiI-positive islets remained intact. Radial lectin-positive capillary sprouts with DiI labeling were observed to form from islets and connect to host networks. Lectin-positive vessels from host networks were also seen growing toward islets. PECAM and NG2 labeling confirmed that vessels sprouting from islets contained endothelial cells and pericytes. Our results introduce the rat mesentery culture model as a platform for investigating dynamics associated with the initial revascularization of transplanted islets.

Viewing stromal vascular fraction de novo vessel formation and association with host microvasculature using the rat mesentery culture model.

OBJECTIVE: The objective of the study is to demonstrate the innovation and utility of mesenteric tissue culture for discovering the microvascular growth dynamics associated with adipose-derived stromal vascular fraction (SVF) transplantation. Understanding how SVF cells contribute to de novo vessel growth (i.e., neovascularization) and host network angiogenesis motivates the need to make observations at single-cell and network levels within a tissue. METHODS: Stromal vascular fraction was isolated from the inguinal adipose of adult male Wistar rats, labeled with DiI, and seeded onto adult Wistar rat mesentery tissues. Tissues were then cultured in MEM + 10% FBS for 3 days and labeled for BSI-lectin to identify vessels. Alternatively, SVF and tissues from green fluorescent-positive (GFP) Sprague Dawley rats were used to track SVF derived versus host vasculature. RESULTS: Stromal vascular fraction-treated tissues displayed a dramatically increased vascularized area compared to untreated tissues. DiI and GFP+ tracking of SVF identified neovascularization involving initial segment formation, radial outgrowth from central hub-like structures, and connection of segments. Neovascularization was also supported by the formation of segments in previously avascular areas. New segments characteristic of SVF neovessels contained endothelial cells and pericytes. Additionally, a subset of SVF cells displayed the ability to associate with host vessels and the presence of SVF increased host network angiogenesis. CONCLUSIONS: The results showcase the use of the rat mesentery culture model as a novel tool for elucidating SVF cell transplant dynamics and highlight the impact of model selection for visualization.

An Ex Vivo Tissue Culture Method for Discovering Cell Dynamics Involved in Stromal Vascular Fraction Vasculogenesis Using the Mouse Mesentery.

Stromal vascular fraction (SVF), isolated from adipose tissue, identifies as a rich cell source comprised of endothelial cells, endothelial progenitor cells, pericytes, smooth muscle cells, fibroblasts, and immune cells. SVF represents a promising therapeutic heterogonous cell source for growing new blood microvessels due to its rich niche of cells. However, the spatiotemporal dynamics of SVF within living tissues remain largely unknown. The objective of this chapter is to describe a protocol for culturing SVF on mouse mesentery tissues in order to aid in the discovery of SVF dynamics and associated vessel growth over time. SVF was isolated from the inguinal adipose from adult mice and seeded onto mesentery tissues. Tissues were then cultured for up to 5 days and labeled with endothelial cell and pericyte markers. Representative results demonstrate the observation of SVF-derived vasculogenesis characterized by de novo vessel formation and subsequent vessel connection.

Warfarin-induced vitamin K deficiency affects spermatogenesis in Sprague-Dawley rats.

Vitamin K is present in the testes though its actual function in male reproduction is poorly understood. This study investigated the harmful effect of extrahepatic vitamin K insufficiency on the testicular structure. Sprague-Dawley rats were fed with a diet containing warfarin for 2, 4 and 8 weeks; control animals received a standard diet without warfarin. It was found that extrahepatic vitamin K deficiency that is induced by warfarin results in histopathological features that range from delayed spermiation, presence of multinucleated giant cells in the seminiferous tubules, germ cells degeneration, asthenozoospermia, oligozoospermia and increase in the percentage of abnormal sperm morphology when compared to the controls. Data obtained from the two groups were analysed using the Student t test. It is concluded that warfarin-induced vitamin K deficiency has a negative impact on spermatogenesis.

Serum Levels of Inflammatory Cytokines in Helminth Infested Pregnant Women and Cord Blood of their Babies in Relation to Pregnancy Outcome.

Pregnancy places a very high demand on physical, physiological and immunological responses of females,especially when aggravated by parasitic infestation. There is strong evidence that maternal infestations with helminth haveprofound effects on immunity to helminths and other pathogens. This case-control study involved 245 pregnant women aged18-40 years (>30 weeks of gestation) recruited from three secondary level hospitals in Ibadan, Nigeria. Morning stoolsamples collected from pregnant women were examine for intestinal helminths using formol-ether concentration method. Atotal of 38 participants comprising 17 Helminth Positive (HP) and 21 Helminth Negative (HN) pregnant women werepurposely selected for the study. Sera from these women (38) and their babies' cord (38) were analysed for immune factors[interleukins 6 and 8 (IL-6, IL-8), tumor necrosis factor-alpha (TNF-α) and immunoglobulin E (IgE)] were analyzed usingELISA. Anthropometric indices [weight and height in mothers and babies and Chest Circumference (CC) in babies] weremeasured using standard methods. Data were subjected to descriptive statistics and analysed using Student t-test and Pearsoncorrelation at α0.05. Only Ascaris lumbricoides was found in the 17 (6.9%) infested pregnant women. The mean levels of IL-6 (57.8 ± 32.8 vs 52.8±39.6 pg/mL), IL-8 (24.3±3.5 vs 22.0±7.1 pg/mL) and IgE (333.3±96.6 vs 242.3±96.8 IU/mL) weresimilar in HP when compared with HN. In cord sera, IL-8 level was significantly higher in babies of HP (23.7±3.9 pg/mL)compared with babies of HN (20.1±5.9 pg/mL). The levels of IL-6, TNF-α and nutritional indices in HP had significantpositive correlation with corresponding levels in babies of HP mothers. Only CC was significantly lowered in babies of HPcompared with HN mothers. Other anthropometric indices were not significantly different. Therefore, this present studysuggests that helminth infestation may lead to strong Th2 immune responses as is reflected by the cytokine levels of mothersand babies as well as anthropometric measurements of babies of infested mothers. The outcomes of this study provide basisto deworm pregnant women during pregnancy.

Changes in mediators of inflammation and pro-thrombosis after 12 months of dietary modification in adults with metabolic syndrome.

OBJECTIVE: This study evaluated the effects of a 12-month dietary modification on indices of inflammation and pro-thrombosis in adults with metabolic syndrome (MS). MATERIALS AND METHODS: This longitudinal study involved 252 adults with MS recruited from the Bodija market, Ibadan and its environs. Participants were placed on 20%, 30% and 50% calories obtained from protein, total fat and carbohydrate respectively and were followed up monthly for 12 months. Anthropometry and blood pressure were measured using standard methods. Fasting plasma glucose (FPG), total cholesterol (TC), triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), fibrinogen, plasminogen activator inhibitor-1 (PAI-1)], interleukin-6 (IL-6) and interleukin-10 (IL-10) were measured using spectrophotometric methods and ELISA as appropriate. Data was analysed using ANCOVA, Student's t-test, Mann-Whitney U and Wilcoxon signed-rank tests. P-values less than 0.05 were considered significant. RESULTS: After 6 months of dietary modification, there was a significant reduction in waist circumference (WC), while the levels of HDL-C, fibrinogen and PAI-1 were significantly increased when compared with the corresponding baseline values. However, WC and fibrinogen reduced significantly, while HDL-C and IL-10 significantly increased after 12 months of dietary modification as compared with the respective baseline values. CONCLUSION: Long-term regular dietary modification may be beneficial in ameliorating inflammation and pro-thrombosis in metabolic syndrome.

Anthropometric Indices and Serum Micronutrient Status of Helminth - Infected School Children from Semi-Urban Communities in Southwestern Nigeria.

Adequate nutrition is essential for normal growth of children but helminth infection is proposed to cause nutritional deficiencies. This study was carried out to assess the nutritional status of helminth infected school aged children in semi-urban communities of South-West Nigeria. Two hundred children from primary schools in Akinyele Local Government of Oyo State, Nigeria participated in the study. Anthropometric measurements were analyzed using the WHO AnthroPlus software. Kato Katz method was used to detect ova of helminths in the stool while serum levels of iron, zinc, selenium, ferritin, transferrin, vitamin A, vitamin C and haptoglobin were measured using High Performance Liquid Chromatography and Atomic Absorption Spectophotometry as appropriate. 60 (30%) of the children had intestinal helminth infection with Ascaris lumbricoides (23.0%) as most prevalent, followed by hookworm (2.5%) and Trichuris trichuria (0.5%).  Stunting was more prevalent than thinness or underweight among the study population especially the female children. There were significantly reduced serum levels of zinc and vitamin A and significantly increased serum levels of transferrin and selenium in helminth-infected children compared with helminth-uninfected children. This study established the need for regular deworming of school age children and supplementing diets of school children in rural communities with vitamin A and zinc.

Plasma Adenosine Deaminase Enzyme Reduces with Treatment of Pulmonary Tuberculosis in Nigerian Patients: Indication for Diagnosis and Treatment Monitoring.

Tuberculosis(TB)-specific host biomarkers for diagnosis and monitoring of treatment response have been identified as priorities for TB research. Macrophage and T cell lymphocytes play vital roles in Mycobacterium tuberculosis immune response and their associated biomarkers could form good candidates for diagnosis and treatment monitoring. The enzyme adenosine deaminase (ADA) is produced mainly by monocytes and macrophages and increase in biological fluids in the course of infection with microorganisms infecting macrophages. This study comprised sixty-eight (68) participants; twenty-four (24) multi-drug-resistant TB(MDR-TB) patients, twenty-four (24) drug-sensitive TB patients(DS-TB) and twenty (20) non-TB apparently healthy individuals. Five (5) milliliters of blood was drawn before commencement of chemotherapy and 6 anti-TB therapy. In DSTB and MDR-TB patients before commencement of chemotherapy and 6 months of anti-TB treatment, the mean plasma levels of ADA were significantly increased compared with control. At 6 months of anti-TB chemotherapy of DSTB or MDR TB patients, ADA level was significantly decreased compared with before chemotherapy. Plasma ADA in DSTB patients before and 6 months of chemotherapy were not significantly different compared MDR TB patients. Plasma ADA level is a promising biomarker for the screening and treatment monitoring of pulmonary tuberculosis but not to differentiate MDR TB from DSTB patients.

Serum Levels of Selected Vitamins and Trace Elements in Nigerian Consumers of Alcoholic Beverage: A Suggestion for DNA Hypomethylation.

Folic acid, vitamins and Zinc play essential role in DNA methylation but alcohol consumption is known to affectthe levels of these micronutrients leading to risk of developing various illnesses and certain cancers. This study determinedthe levels of DNA methylation dependent-micronutrients (folate, vitamin B12, vitamin B6, zinc and selenium) andhomocysteine as a suggestion for DNA methylation status in Nigerian alcohol consumers compared with non-consumers ofalcohol. Venous blood (5ml) was obtained from thirty-four males that consume alcoholic beverages for at least 10 years andthirty-two male controls that did not consume alcoholic beverages at least 10 years. Serum concentrations of folate, vitaminB12, vitamin B6, homocysteine (Hcy), selenium (Se) and zinc (Zn) were determined using High Performance LiquidChromatography (HPLC) and Atomic Absorption Spectrophotometry (AAS) as appropriate. Independent Student t-test wasused to compare the mean values between alcohol consumers and control. Mean differences were considered significant atp<0.05. The mean serum levels of Zn and Se were significantly raised in alcohol consumers when compared with nonalcohol consumers while the mean levels of Vitamin B6 and Hcy were significantly reduced in alcohol consumers whencompared with non-alcohol consumers. There were no statistically significant differences in the mean serum levels ofVitamin B12 and folate in alcohol consumers when compared with non-alcohol consumers. Since vitamin B6 and Hcy arerequired for DNA methylation, reduced vitamin B6 and Hcy levels in consumers of alcoholic beverages might suggest DNAhypomethylation in alcohol consumers.

Pneumococcal-specific IgG levels after 13-valent pneumococcal conjugate vaccination in Nigerian children with sickle cell disease.

BACKGROUND: Children with sickle cell disease (SCD) are particularly susceptible to pneumococcal infection. Administration of the 13-valent conjugate pneumococcal vaccine which is now available in Nigeria may help to reduce the incidence. OBJECTIVES: To determine the serum level of pneumococcal-specific IgG (PIgG) in a cohort of patients with SCD after administration of a single-dose of a 13-valent pneumococcal conjugate vaccine. METHODS: The study was conducted between December 2011 and March 2012 among children with SCD aged 5 months to 5 years attending the sickle cell clinic in five public hospitals in Lagos. Altogether, 151 children with SCD and 52 without it (controls) were recruited by convenience sampling from the sickle cell clinics and well-child clinics. Blood samples were collected for PIgG concentrations before and 2 months after a single dose of the Prevenar 13 vaccine. Seroconversion was defined as a fourfold or greater increase in antibody concentration after vaccination while those with PIgG concentrations ≥200 µU/ml were considered to have protective levels. RESULTS: The age range of the total study group was 5-60 months with a mean (SD) of 39.04 (15.44) months and a median of 39 months. The mean (SD) ages of subjects with and without SCD were 38.91 (15.75) months and 16.39 (15.45) months, respectively. The PIgG concentration 2 months post-vaccination was significantly greater than the pre-vaccination levels in all age categories in both groups and almost all subjects had protective PIgG concentrations 2 months after vaccination. A four-fold increase in PIgG concentration was detected more commonly in the controls than in SCD patients. CONCLUSION: Prevenar 13 provided protective immunity in all vaccinated children but those under 2 years of age who had non-protective levels pre-vaccination benefited the most.

Physical activity and pattern of blood pressure in postmenopausal women with hypertension in Nigeria.

BACKGROUND: Hormonal changes during menopause have been attributed to hypertension-a common public health concern. This study investigated physical activity (PA) and pattern of blood pressure (BP) in postmenopausal women newly diagnosed with hypertension and referred for treatment at the medicine outpatient clinic of a tertiary health facility in Ibadan, Oyo State, Nigeria. It compared BP pattern and adiposity variables [body mass index (BMI) and waist-hip ratio (WHR)] between two PA groups. METHODS: Purposive sampling technique was used to recruit 220 participants in this cross-sectional survey after obtaining their informed consent. International Physical Activity Questionnaire was used to assess PA level, while a 16-item questionnaire was used to assess socio-demographic and clinical profiles of the women. BP, BMI and WHR were assessed using standard measurement procedures. Descriptive statistics of mean ± standard deviation were used for data summarization and independent t-test was used to compare variables between low level and moderate to vigorous level PA groups. RESULTS: Participants' mean values include: age 61.6 ± 8.5 years, years since menopause 12.75± 8.15, BMI 28.63±4.99kg/m(2), WHR 1.11±0.08, SBP and DBP 145.9±17.9; 93.7±11.4 mmHg respectively. Mean values of SBP, DBP, BMI and WHR were higher among participants with low PA compared to those with moderate to vigorous even though the difference was not statistically significant (P>0.05). CONCLUSION: Involvement in moderate to vigorous physical activities among menopausal women in Nigeria should be encouraged. This may reduce hypertension and adiposity with a possible control of cardiovascular disease risk.

Metabolic alterations in different stages of hypertension in an apparently healthy nigerian population.

Metabolic syndrome (MS) amplifies hypertension (HTN) associated with increased risk of cardiovascular disease (CVD). MS components and other CVD risk measures were investigated in different stages of hypertension. 534 apparently healthy Nigerian traders aged 18-105 years were participants of a cohort study. The International Diabetes Federation (2005) and the National High Blood Pressure Education Program Coordinating Committee criteria were used for MS and HTN classifications, respectively. Anthropometric indices were obtained by standard methods. Levels of fasting plasma glucose (FPG), total cholesterol (TC), triglyceride (TG), and high-density lipoprotein cholesterol (HDLC) were determined by enzymatic methods, while low-density lipoprotein cholesterol (LDLC) was calculated. Data analysed statistically were significant at P < 0.05. 143 (26.8%), 197 (36.9%), and 194 (36.3%) of the traders had normotension, pre-HTN and HTN (stages 1 and 2), respectively. All indices tested except HDLC were significantly different among BP groups (P < 0.05). Waist to hip (WHR) and waist to height (WHT) ratios were significantly different between HTN groups (P < 0.05). HTN was associated with MS and female gender (P < 0.05). Metabolic alterations and significant HTN were observed. Treatment of the individual components of the syndrome and improvement of modifiable metabolic factors may be necessary to reduce MS and high BP.

Allergy sensitization and asthma among 13-14 year old school children in Nigeria.

BACKGROUND: The prevalence of asthma and role of atopy in asthma among children has not been clearly defined in Nigeria. OBJECTIVE: To determine the prevalence of asthma and investigate risk factors related to allergy sensitization among urban and rural school children in southwest Nigeria. METHODS: Validated ISAAC questionnaire was administered to 1736 high school children in randomly selected schools in rural and urban communities. Identified asthma cases were matched to controls. Allergy skin tests, blood eosinophil count, serum IgE and stool examination for parasites were performed. Dust samples from homes were also collected and analyzed for allergens. RESULTS: The prevalence of asthma was 7.5% (95% CI 6.0 to 9.2%) and 8% (95% CI 6.0-10.4%) in the rural and urban communities respectively . Risk factors for asthma included cigarette-smoking, cats in the home and family size. Eosinophil count (109/L) was elevated in asthmatics [0.70 (95% CI 0.48-1.11) vs. 0.32 (95% CI 0.19-0.69); p<0.01], but IgE levels were similar between the two groups (298±229 IU/mL vs. 288±257; p=0.97). Positive skin tests to cat hair, cockroach, mango blossom and mouse epithelium were more frequent in asthmatics than in healthy controls, especially in the rural communities. There was no correlation between allergens in dust collected from homes and skin test reactivity. CONCLUSION: Asthma prevalence is similar in rural and urban children in Southwest Nigeria and atopy with elevated IgE was not observed to be a major factor for asthma in our cohort of children in both communities.