Peripheral blood as a potential source for Alzheimer's disease biomarkers

Alzheimer’s disease (AD) is characterised by two major histological hallmarks; neurofibrillary tangles (NFT) and neuritic plaques. But, unlike plaques, the degree of NFT deposition in the brain correlates to the severity of clinical symptoms of neuronal dysfunction. The major constituent of NFT is hyperphosphorylated tau protein. The involvement of neuropsychological testing, neuroimaging techniques and biochemical measurement of cerebrospinal fluid markers (amyloid beta and tau proteins) have improved the sensitivity and specificity of AD diagnosis. But these diagnostic methods are challenged by individual’s education level, high cost and its invasiveness, hence the need for an alternative analysis platform that overcome these challenges. Peripheral blood fulfils the criteria as a suitable medium to evaluate AD diagnostic markers. Since NFT deposition correlates with neuronal dysfunction severity and the NFT is constituted mainly of hyperphosphorylated tau protein then, the evaluation of tau in peripheral blood could provide useful information about AD progression. As tau protein in blood is susceptible to thrombin degradation, tau may be enwrapped in a vesicle such as extracellular vesicles (ECVs). The ECVs are formed when a multivesicular body fuses with the plasma membrane and release its contents into the extracellular milieu. The formation and release of these ECVs are ubiquitous and cell type specific. Besides, ECVs contain several cargo molecules such as proteins, and it can cross the blood brain barrier into peripheral blood. Therefore, blood-based neuron derived extracellular vesicles (ndECVs) could be a dependable source to measure AD-like tau protein. At present, the significance of tau protein in blood-based ndECVs for the diagnosis of AD remains largely unclear. Hence, this study aimed to quantify tau protein in peripheral blood ndECVs using flow cytometry technique and evaluate the significance of this measured proteins in the diagnosis of AD. This study set the following objectives: (1) Establish a protocol for the isolation and characterization of ECVs and ndECVs using western blot and flow cytometry techniques, (2). Use the flow cytometry platform to quantify tau protein in the ndECVs of clinical patients who had already undergone clinical diagnostic (such as CSF tau, CSF p-tau, CSF β-amyloid or MMSE evaluation). (3).Evaluate the significance of tau protein in the ndECVs as a potential biomarker for AD. Using the bead-assisted technique ECVs and ndECVs were isolated from serum and analysed. This study made attempt to measure tau protein in peripheral blood ndECVs using flow cytometry technique. While quantification of tau protein by flow cytometry platform posed a challenge, ELISA technique was used as alternative to measure the proteins in the ECVs. Tau protein was measured in some of the ndECVs, but study did not observe any significant correlation between measured tau protein in ndECVs and the validated diagnostic markers (CSF tau, CSF p-tau, CSF β-amyloid or MMSE evaluation). Of interest was the trend for a negative correlation between serum tau protein and CSF β-amyloid. Peripheral blood is a relevant source for tau protein measurement and therefore more studies are needed to evaluate the significance of blood serum tau content as a diagnostic biomarker for AD.:TABLE OF CONTENT LIST OF ABBREVIATION III LIST OF FIGURES V 1. INTRODUCTION 1 1.1. ALZHEIMER’S DISEASE 1 1.1.1. The neuritic plaque 2 1.1.2. The neurofibrillary tangles 2 1.1.3. Pathophysiology of NFT 3 1.2. EPIDEMIOLOGY AND SOCIO-ECONOMIC BURDEN OF ALZHEIMER’S DISEASE 4 1.3. CLINICAL DIAGNOSIS OF ALZHEIMER’S DISEASE 5 1.4. CHALLENGES ASSOCIATED WITH THE CURRENT DIAGNOSIS OF AD 7 1.5. EXTRACELLULAR VESICLES 8 1.5.1. Formation of ECVs (ectosomes and exosomes) 9 1.5.2. Size, density and composition of ECVs 9 1.5.3. Functions of central nervous system ECVs 10 1.6. TAU PROTEIN, ECVS AND PERIPHERAL BLOOD 11 1.7. AIM OF THE STUDY 13 1.8. OBJECTIVES 13 2. METHODOLOGY 15 2.1. STUDY DESIGN 15 2.2. ETHICAL ISSUES 15 2.3. MATERIALS 15 2.4. METHODS 21 2.4.1. Blood sampling 21 2.4.2. SH-SY5Y Cell culture processing 21 2.4.3. Isolation of ECVs 22 2.4.4. Detection, characterization and quantification of ECVs and the cargo tau protein 26 2.5. STATISTICAL ANALYSIS 31 3. RESULTS 32 3.1. ESTABLISHMENT OF PROTOCOL FOR THE ISOLATION AND CHARACTERISATION OF ECVS 32 3.1.1. Precipitation versus ultracentrifugation techniques of isolating ECVs 32 3.1.2. Purification of ECVs using iodixanol or sucrose density gradient 33 3.1.3. Demonstration of other marker proteins of ECVs 34 3.1.4. Analysis of reproducibility 36 3.1.5. ECVs’ density determination 37 3.1.6. Comparing serum and plasma as ideal starting material 41 3.1.7. Optimal minimum starting volume of serum 43 3.1.8. Isolation of ndECVs from ultracentrifuge or pre-cleaned serum 44 3.2. DETECTION AND QUANTIFICATION OF ECVS’ CARGO PROTEINS, HSP70 AND TAU 45 3.2.1. western blot technique 46 3.2.2. Flow cytometry 47 3.2.3. ELISA as an alternative approach to quantify of tau protein in ndECVs 49 4. DISCUSSION 56 4.1. BASIS FOR CONSIDERING BLOOD-BASED MARKERS FOR THE DIAGNOSIS OF AD 56 4.2. BASIS FOR TARGETING TAU PROTEIN IN PERIPHERAL BLOOD 57 4.3. POTENTIAL ROLE OF NDECVS IN THE TRANSPORTATION OF TAU PROTEIN 58 4.4. ESTABLISHMENT OF PROTOCOL FOR ISOLATION AND CHARACTERISATION OF ECVS 59 4.4.1. Precipitation versus ultracentrifugation 60 4.4.2. Purification of ECVs by density gradient technique 61 4.4.3. Detection of ECVs’ cargo protein using western blot technique 63 4.4.4. ECVs isolation using the Bead-assisted technique 64 4.4.5. Isolation of cell type specific ECVs (ndECVs) 65 4.4.6. Comparison of plasma and serum as a source of ndECVs 66 4.5. DETECTION AND QUANTIFICATION OF ECVS’ CARGO PROTEINS (HSP70 & TAU) 67 4.5.1. Flow cytometry analysis 67 4.5.2. ELISA analysis 68 4.5.3. Tau protein in the ECVs of hibernating animals 71 5. CONCLUSION 73 6. REFERENCES 74 7. APPENDICES 100 7.1. CURRICULUM VITAE 100 7.2. PUBLICATIONS 101 7.3. DECLARATION OF THE INDEPENDENT WRITING OF THIS THESIS 103 7.4. ACKNOWLEDGEMENT 10

Detection of Human Papillomavirus Genotypes and Epstein-Barr Virus in Nasopharyngeal Carcinomas at the Korle-Bu Teaching Hospital, Ghana

Nasopharyngeal carcinomas (NPC) are endemic in Far East Asia and commonly harbour Epstein-Barr virus (EBV) which is known to serve as a key oncogenic promoter. Human papillomavirus (HPV) is known to contribute to the pathogenesis of NPC. However, in Ghana these two viruses have not been linked to NPC prevalence. This study was designed to determine the HPV genotypes and EBV involved in NPC tissue biopsies. A retrospective study design involving 72 formalin-fixed paraffin-embedded tissue (FFPET) samples of NPC from 2006 to 2012 were retrieved from the Department of Pathology, University of Ghana School of Biomedical and Allied Health Sciences. Sections were taken for histological analysis and for DNA lysate preparation. The DNA lysates were subjected to polymerase chain reaction (PCR) analysis to determine the presence of HPV genotypes and EBV. HPV specific primers were used to type for fourteen HPV genotypes (HPV-16, 18, 6/11, 31, 33, 35, 44, 42, 43, 45, 56, 52, 58, and 59). Out of the 72 NPC biopsies analyzed by PCR, EBV DNA was present in 18 (25%) cases and HPV DNA in 14 (19.23%). High risk HPV (HR-HPV) genotypes 18 and 31 were associated with the NPC. There were 3 (4.2%) cases of coinfection by both viruses. The EBV DNA present in the undifferentiated variant of the NPC and the histopathology of the NPC in Ghana is similar to the type described in endemic areas

HER-2 Protein Overexpression in Patients with Gastric and Oesophageal Adenocarcinoma at a Tertiary Care Facility in Ghana

The prognosis of gastric and oesophageal adenocarcinoma remains generally poor. However, mounting evidence suggests a positive role of human epidermal growth factor receptor-2 (HER-2) expression in the prognosis of patients with these cancers. In this work, the patterns of HER-2 protein expression were determined in patients with gastric or oesophageal adenocarcinoma. Retrospectively, we reviewed records of gastric and oesophageal biopsies received from 2008 to 2012 and their corresponding archived formalin-fixed paraffin-embedded tissue blocks selected for immunohistochemical analysis. The prevalence of gastric and oesophageal adenocarcinomas and their association with HER-2 protein overexpression were evaluated. Gastric adenocarcinoma made up 18.79% of the gastric biopsies reviewed, and majority of these cancers occurred in males. Regarding the tumour type, HER-2 overexpression was common in the intestinal subtype compared to the diffuse type. Although squamous cell carcinoma was observed to be the commonest (31%) tumour type in the oesophagus compared to adenocarcinoma (8.79%), HER-2 was overexpressed in 42.9% of oesophageal adenocarcinomas, like gastric adenocarcinoma (41.4%). There is a high prevalence of gastric and oesophageal adenocarcinoma, with significant overexpression of HER-2 in these tumours, a window of hope for the management of patients with these cancers

Peripheral blood as a potential source for Alzheimer's disease biomarkers

Alzheimer’s disease (AD) is characterised by two major histological hallmarks; neurofibrillary tangles (NFT) and neuritic plaques. But, unlike plaques, the degree of NFT deposition in the brain correlates to the severity of clinical symptoms of neuronal dysfunction. The major constituent of NFT is hyperphosphorylated tau protein. The involvement of neuropsychological testing, neuroimaging techniques and biochemical measurement of cerebrospinal fluid markers (amyloid beta and tau proteins) have improved the sensitivity and specificity of AD diagnosis. But these diagnostic methods are challenged by individual’s education level, high cost and its invasiveness, hence the need for an alternative analysis platform that overcome these challenges. Peripheral blood fulfils the criteria as a suitable medium to evaluate AD diagnostic markers. Since NFT deposition correlates with neuronal dysfunction severity and the NFT is constituted mainly of hyperphosphorylated tau protein then, the evaluation of tau in peripheral blood could provide useful information about AD progression. As tau protein in blood is susceptible to thrombin degradation, tau may be enwrapped in a vesicle such as extracellular vesicles (ECVs). The ECVs are formed when a multivesicular body fuses with the plasma membrane and release its contents into the extracellular milieu. The formation and release of these ECVs are ubiquitous and cell type specific. Besides, ECVs contain several cargo molecules such as proteins, and it can cross the blood brain barrier into peripheral blood. Therefore, blood-based neuron derived extracellular vesicles (ndECVs) could be a dependable source to measure AD-like tau protein. At present, the significance of tau protein in blood-based ndECVs for the diagnosis of AD remains largely unclear. Hence, this study aimed to quantify tau protein in peripheral blood ndECVs using flow cytometry technique and evaluate the significance of this measured proteins in the diagnosis of AD. This study set the following objectives: (1) Establish a protocol for the isolation and characterization of ECVs and ndECVs using western blot and flow cytometry techniques, (2). Use the flow cytometry platform to quantify tau protein in the ndECVs of clinical patients who had already undergone clinical diagnostic (such as CSF tau, CSF p-tau, CSF β-amyloid or MMSE evaluation). (3).Evaluate the significance of tau protein in the ndECVs as a potential biomarker for AD. Using the bead-assisted technique ECVs and ndECVs were isolated from serum and analysed. This study made attempt to measure tau protein in peripheral blood ndECVs using flow cytometry technique. While quantification of tau protein by flow cytometry platform posed a challenge, ELISA technique was used as alternative to measure the proteins in the ECVs. Tau protein was measured in some of the ndECVs, but study did not observe any significant correlation between measured tau protein in ndECVs and the validated diagnostic markers (CSF tau, CSF p-tau, CSF β-amyloid or MMSE evaluation). Of interest was the trend for a negative correlation between serum tau protein and CSF β-amyloid. Peripheral blood is a relevant source for tau protein measurement and therefore more studies are needed to evaluate the significance of blood serum tau content as a diagnostic biomarker for AD.:TABLE OF CONTENT LIST OF ABBREVIATION III LIST OF FIGURES V 1. INTRODUCTION 1 1.1. ALZHEIMER’S DISEASE 1 1.1.1. The neuritic plaque 2 1.1.2. The neurofibrillary tangles 2 1.1.3. Pathophysiology of NFT 3 1.2. EPIDEMIOLOGY AND SOCIO-ECONOMIC BURDEN OF ALZHEIMER’S DISEASE 4 1.3. CLINICAL DIAGNOSIS OF ALZHEIMER’S DISEASE 5 1.4. CHALLENGES ASSOCIATED WITH THE CURRENT DIAGNOSIS OF AD 7 1.5. EXTRACELLULAR VESICLES 8 1.5.1. Formation of ECVs (ectosomes and exosomes) 9 1.5.2. Size, density and composition of ECVs 9 1.5.3. Functions of central nervous system ECVs 10 1.6. TAU PROTEIN, ECVS AND PERIPHERAL BLOOD 11 1.7. AIM OF THE STUDY 13 1.8. OBJECTIVES 13 2. METHODOLOGY 15 2.1. STUDY DESIGN 15 2.2. ETHICAL ISSUES 15 2.3. MATERIALS 15 2.4. METHODS 21 2.4.1. Blood sampling 21 2.4.2. SH-SY5Y Cell culture processing 21 2.4.3. Isolation of ECVs 22 2.4.4. Detection, characterization and quantification of ECVs and the cargo tau protein 26 2.5. STATISTICAL ANALYSIS 31 3. RESULTS 32 3.1. ESTABLISHMENT OF PROTOCOL FOR THE ISOLATION AND CHARACTERISATION OF ECVS 32 3.1.1. Precipitation versus ultracentrifugation techniques of isolating ECVs 32 3.1.2. Purification of ECVs using iodixanol or sucrose density gradient 33 3.1.3. Demonstration of other marker proteins of ECVs 34 3.1.4. Analysis of reproducibility 36 3.1.5. ECVs’ density determination 37 3.1.6. Comparing serum and plasma as ideal starting material 41 3.1.7. Optimal minimum starting volume of serum 43 3.1.8. Isolation of ndECVs from ultracentrifuge or pre-cleaned serum 44 3.2. DETECTION AND QUANTIFICATION OF ECVS’ CARGO PROTEINS, HSP70 AND TAU 45 3.2.1. western blot technique 46 3.2.2. Flow cytometry 47 3.2.3. ELISA as an alternative approach to quantify of tau protein in ndECVs 49 4. DISCUSSION 56 4.1. BASIS FOR CONSIDERING BLOOD-BASED MARKERS FOR THE DIAGNOSIS OF AD 56 4.2. BASIS FOR TARGETING TAU PROTEIN IN PERIPHERAL BLOOD 57 4.3. POTENTIAL ROLE OF NDECVS IN THE TRANSPORTATION OF TAU PROTEIN 58 4.4. ESTABLISHMENT OF PROTOCOL FOR ISOLATION AND CHARACTERISATION OF ECVS 59 4.4.1. Precipitation versus ultracentrifugation 60 4.4.2. Purification of ECVs by density gradient technique 61 4.4.3. Detection of ECVs’ cargo protein using western blot technique 63 4.4.4. ECVs isolation using the Bead-assisted technique 64 4.4.5. Isolation of cell type specific ECVs (ndECVs) 65 4.4.6. Comparison of plasma and serum as a source of ndECVs 66 4.5. DETECTION AND QUANTIFICATION OF ECVS’ CARGO PROTEINS (HSP70 & TAU) 67 4.5.1. Flow cytometry analysis 67 4.5.2. ELISA analysis 68 4.5.3. Tau protein in the ECVs of hibernating animals 71 5. CONCLUSION 73 6. REFERENCES 74 7. APPENDICES 100 7.1. CURRICULUM VITAE 100 7.2. PUBLICATIONS 101 7.3. DECLARATION OF THE INDEPENDENT WRITING OF THIS THESIS 103 7.4. ACKNOWLEDGEMENT 10

Peripheral blood as a potential source for Alzheimer's disease biomarkers

Alzheimer’s disease (AD) is characterised by two major histological hallmarks; neurofibrillary tangles (NFT) and neuritic plaques. But, unlike plaques, the degree of NFT deposition in the brain correlates to the severity of clinical symptoms of neuronal dysfunction. The major constituent of NFT is hyperphosphorylated tau protein. The involvement of neuropsychological testing, neuroimaging techniques and biochemical measurement of cerebrospinal fluid markers (amyloid beta and tau proteins) have improved the sensitivity and specificity of AD diagnosis. But these diagnostic methods are challenged by individual’s education level, high cost and its invasiveness, hence the need for an alternative analysis platform that overcome these challenges. Peripheral blood fulfils the criteria as a suitable medium to evaluate AD diagnostic markers. Since NFT deposition correlates with neuronal dysfunction severity and the NFT is constituted mainly of hyperphosphorylated tau protein then, the evaluation of tau in peripheral blood could provide useful information about AD progression. As tau protein in blood is susceptible to thrombin degradation, tau may be enwrapped in a vesicle such as extracellular vesicles (ECVs). The ECVs are formed when a multivesicular body fuses with the plasma membrane and release its contents into the extracellular milieu. The formation and release of these ECVs are ubiquitous and cell type specific. Besides, ECVs contain several cargo molecules such as proteins, and it can cross the blood brain barrier into peripheral blood. Therefore, blood-based neuron derived extracellular vesicles (ndECVs) could be a dependable source to measure AD-like tau protein. At present, the significance of tau protein in blood-based ndECVs for the diagnosis of AD remains largely unclear. Hence, this study aimed to quantify tau protein in peripheral blood ndECVs using flow cytometry technique and evaluate the significance of this measured proteins in the diagnosis of AD. This study set the following objectives: (1) Establish a protocol for the isolation and characterization of ECVs and ndECVs using western blot and flow cytometry techniques, (2). Use the flow cytometry platform to quantify tau protein in the ndECVs of clinical patients who had already undergone clinical diagnostic (such as CSF tau, CSF p-tau, CSF β-amyloid or MMSE evaluation). (3).Evaluate the significance of tau protein in the ndECVs as a potential biomarker for AD. Using the bead-assisted technique ECVs and ndECVs were isolated from serum and analysed. This study made attempt to measure tau protein in peripheral blood ndECVs using flow cytometry technique. While quantification of tau protein by flow cytometry platform posed a challenge, ELISA technique was used as alternative to measure the proteins in the ECVs. Tau protein was measured in some of the ndECVs, but study did not observe any significant correlation between measured tau protein in ndECVs and the validated diagnostic markers (CSF tau, CSF p-tau, CSF β-amyloid or MMSE evaluation). Of interest was the trend for a negative correlation between serum tau protein and CSF β-amyloid. Peripheral blood is a relevant source for tau protein measurement and therefore more studies are needed to evaluate the significance of blood serum tau content as a diagnostic biomarker for AD.:TABLE OF CONTENT LIST OF ABBREVIATION III LIST OF FIGURES V 1. INTRODUCTION 1 1.1. ALZHEIMER’S DISEASE 1 1.1.1. The neuritic plaque 2 1.1.2. The neurofibrillary tangles 2 1.1.3. Pathophysiology of NFT 3 1.2. EPIDEMIOLOGY AND SOCIO-ECONOMIC BURDEN OF ALZHEIMER’S DISEASE 4 1.3. CLINICAL DIAGNOSIS OF ALZHEIMER’S DISEASE 5 1.4. CHALLENGES ASSOCIATED WITH THE CURRENT DIAGNOSIS OF AD 7 1.5. EXTRACELLULAR VESICLES 8 1.5.1. Formation of ECVs (ectosomes and exosomes) 9 1.5.2. Size, density and composition of ECVs 9 1.5.3. Functions of central nervous system ECVs 10 1.6. TAU PROTEIN, ECVS AND PERIPHERAL BLOOD 11 1.7. AIM OF THE STUDY 13 1.8. OBJECTIVES 13 2. METHODOLOGY 15 2.1. STUDY DESIGN 15 2.2. ETHICAL ISSUES 15 2.3. MATERIALS 15 2.4. METHODS 21 2.4.1. Blood sampling 21 2.4.2. SH-SY5Y Cell culture processing 21 2.4.3. Isolation of ECVs 22 2.4.4. Detection, characterization and quantification of ECVs and the cargo tau protein 26 2.5. STATISTICAL ANALYSIS 31 3. RESULTS 32 3.1. ESTABLISHMENT OF PROTOCOL FOR THE ISOLATION AND CHARACTERISATION OF ECVS 32 3.1.1. Precipitation versus ultracentrifugation techniques of isolating ECVs 32 3.1.2. Purification of ECVs using iodixanol or sucrose density gradient 33 3.1.3. Demonstration of other marker proteins of ECVs 34 3.1.4. Analysis of reproducibility 36 3.1.5. ECVs’ density determination 37 3.1.6. Comparing serum and plasma as ideal starting material 41 3.1.7. Optimal minimum starting volume of serum 43 3.1.8. Isolation of ndECVs from ultracentrifuge or pre-cleaned serum 44 3.2. DETECTION AND QUANTIFICATION OF ECVS’ CARGO PROTEINS, HSP70 AND TAU 45 3.2.1. western blot technique 46 3.2.2. Flow cytometry 47 3.2.3. ELISA as an alternative approach to quantify of tau protein in ndECVs 49 4. DISCUSSION 56 4.1. BASIS FOR CONSIDERING BLOOD-BASED MARKERS FOR THE DIAGNOSIS OF AD 56 4.2. BASIS FOR TARGETING TAU PROTEIN IN PERIPHERAL BLOOD 57 4.3. POTENTIAL ROLE OF NDECVS IN THE TRANSPORTATION OF TAU PROTEIN 58 4.4. ESTABLISHMENT OF PROTOCOL FOR ISOLATION AND CHARACTERISATION OF ECVS 59 4.4.1. Precipitation versus ultracentrifugation 60 4.4.2. Purification of ECVs by density gradient technique 61 4.4.3. Detection of ECVs’ cargo protein using western blot technique 63 4.4.4. ECVs isolation using the Bead-assisted technique 64 4.4.5. Isolation of cell type specific ECVs (ndECVs) 65 4.4.6. Comparison of plasma and serum as a source of ndECVs 66 4.5. DETECTION AND QUANTIFICATION OF ECVS’ CARGO PROTEINS (HSP70 & TAU) 67 4.5.1. Flow cytometry analysis 67 4.5.2. ELISA analysis 68 4.5.3. Tau protein in the ECVs of hibernating animals 71 5. CONCLUSION 73 6. REFERENCES 74 7. APPENDICES 100 7.1. CURRICULUM VITAE 100 7.2. PUBLICATIONS 101 7.3. DECLARATION OF THE INDEPENDENT WRITING OF THIS THESIS 103 7.4. ACKNOWLEDGEMENT 10

A Review of African Medicinal Plants and Functional Foods for the Management of Alzheimer's Disease-related Phenotypes, Treatment of HSV-1 Infection and/or Improvement of Gut Microbiota

Alzheimer's disease (AD), which is a progressive neurodegenerative disorder is the most common form of dementia globally. Several studies have suggested alteration in the gut microbiota and HSV-1 infection as contributing factors to the development of the disease. As at now, there are no AD attenuating agents and AD pharmacotherapy is focused on managing symptoms while plants used in ethnomedicine remain potential sources of drugs for the treatment of the condition. Here, we reviewed published databases for African ethnomedicinal plants and functional foods of African origin that are used in the management of AD-related phenotypes, treatment of herpes simplex virus −1 (HSV-1) and/or improvement of gut microbiota. A total of 101 unique plant species and 24 different types of traditionally prepared African functional foodstuff were identified. Of the 101 identified plant species, 50 species serve as functional foodstuffs. Twenty-three (23) of the ethnomedicinal plant families were successfully identified for the treatment and management of AD-related phenotypes and age-related dementia. Eighteen (18) African plant species from 15 families were also identified as potent remedies for HSV-1; while many African wild fruits (3 species), roots and tubers (7 species), leafy vegetables (14 species), and seaweeds (26 species) were functional foods for modifying AD-related phenotypes. It was concluded that African medicinal plants are potential sources of both AD attenuating agents and phytocompounds that may be used against HSV-1 infection and alteration of gut microbiota. Additionally, a number of African functional foods are important sources of prebiotics and probiotics

Prevalence of helicobacter pylori infection among children living in a rural setting in Sub-Saharan Africa

Abstract Background Helicobacter pylori infection affects more than half of the world’s population. It is generally acquired during childhood with no symptoms but has long- term clinical sequelae. This study estimated the prevalence of H. pylori infection amongst children in a rural environment in Africa. Methods We conducted a cross-sectional study over a four (4)-month period within two rural communities. 240 asymptomatic children were tested using lateral flow immunochromatographic assay for the qualitative detection of H. pylori antigen in a fecal specimen. Statistical analysis and processing was done using Stata version 11. Results The mean age of the participants was 10.5 ± 2.7 years with the predominant age range being 8–10 years (34.6%), and a mean household size of 7.1 ± 1.7. The study population showed a female preponderance of 57.1%. 88% of the H. pylori positive children lacked pipe and borehole drinking water. All of the positive H. pylori children practiced open-air defecation. The overall prevalence of H. pylori infection among children in this study was at least 14.2%. Conclusion Our study demonstrated a high prevalence of H. pylori infection among children in a rural setting. Educational status of parents did not affect H. pylori prevalence but increasing household numbers, female gender, source of drinking water other than pipe and borehole, open-air defecation and younger age were associated with a higher H. pylori prevalence

Crude extracts from Allium cepa skin and Sorghum bicolor seed can provide as non-toxic and eco-friendly cytoplasmic stains

Introduction: Staining is an important histological process; however, the use of non-toxic and environmentally friendly products is generally required. We explored the staining quality of two natural plants, Allium cepa skin and Sorghum bicolor seed extract on the cytoplasm. Materials and methods: Distilled water at 37 °C and 1% acid-ethanol were respectively used to extract the dyes from Allium cepa skin and Sorghum bicolor seed. Result: The application of these two dyes on rodent tissue showed an excellent cytoplasmic histomorphology. Conclusion: Allium cepa skin and Sorghum bicolor seed extracts are good cytoplasmic dyes when used as counterstain for haematoxylin

High Iodine Deficiency among Pregnant Women in Periurban Ghana: A Hospital-Based Longitudinal Study

Background. Iodine deficiency causes maternal hypothyroidism which can lead to growth, cognitive, and psychomotor deficit in neonates, infants, and children. This study examined the iodine status of pregnant women in a periurban setting in Ghana. Methods. This longitudinal study recruited 125 pregnant women by purposeful convenience sampling from the antenatal clinic of the Sefwi Wiawso municipal hospital in Ghana. Urinary iodine concentration (UIC) was estimated by the ammonium persulfate method at an estimated gestational age (EGA) of 11, 20, and 32 weeks. Demographic information, iodized salt usage, and other clinical information were collected using a questionnaire. Results. The prevalence of iodine deficiency among the pregnant women was 47.2% at EGA 11 and 60.8% at both EGA of 20 and 32, whereas only 0.8% of participants not using iodized salt had iodine sufficiency at EGA 32. 18.4%, 20%, and 24% of participants using iodized salt had iodine sufficiency at EGA 11, 20, and 32, respectively. Conclusion. A high prevalence of iodine deficiency was observed among our study cohort