Foetal haemoglobin and disease severity in sickle cell anaemia patients in Kampala, Uganda

<p>Abstract</p> <p>Background</p> <p>Sickle cell anaemia (SCA) is a major chronic health problem in Uganda. In patients with SCA, the level of foetal haemoglobin (HbF) has been found to be important in influencing the clinical course of the disease. Thus populations with high levels of HbF like those in Saudi Arabia have been described as having a milder clinical course with fewer complications as compared to populations with lower levels. Disease modifying drugs can increase the Hb F levels and modify the presentation of SCA.</p> <p>Methods</p> <p>This was a cross sectional study in which we determined foetal haemoglobin levels and examined the relationship between HbF levels and disease severity in SCA patients in Mulago Hospital, Kampala, Uganda. We consecutively enrolled 216 children aged 1 year to 18 years with SCA attending the Sickle Cell Clinic at Mulago Hospital whose guardians had given consent. The history included age at onset of initial symptoms and diagnosis, number of hospitalisations and blood transfusions and other complications of SCA (cardiovascular accidents, avascular hip necrosis and priapism). A detailed physical examination was performed to assess the current state and help describe the disease severity for each patient. Blood samples were drawn for HbF levels. HbF levels ≥10% was defined as high.</p> <p>Results</p> <p>Of the 216 children, (80) 37% had HbF levels ≥10%. Significant correlations were observed between HbF level and several clinical parameters independent of age including age at diagnosis (p value 0.013), number of hospitalisations (p value 0.024) and transfusions (p value 0.018) since birth.</p> <p>Conclusion</p> <p>A third of the children with SCA attending the Sickle cell clinic in Mulago Hospital have high HbF levels. Higher HbF level is associated with later onset of symptoms and presentation, and less severe disease characterised by fewer hospitalisations and blood transfusions. We suggest HbF levels should be determined at initial contact for patients with SCA to guide counselling and identify those who may need closer follow up and consideration for disease modifying drugs.</p

Tracking zoonotic pathogens using bloodsucking flies as 'flying syringes'

About 60% of emerging infectious diseases in humans are of zoonotic origin. Their increasing number requires the development of new methods for early detection and monitoring of infectious agents in wildlife. Here, we investigated whether blood meals from hematophagous flies could be used to identify the infectious agents circulating in wild vertebrates. To this aim, 1230 blood-engorged flies were caught in the forests of Gabon. Identified blood meals (30%) were from 20 vertebrate species including mammals, birds and reptiles. Among them, 9% were infected by different extant malaria parasites among which some belonged to known parasite species, others to new parasite species or to parasite lineages for which only the vector was known. This study demonstrates that using hematophagous flies as 'flying syringes' constitutes an interesting approach to investigate blood-borne pathogen diversity in wild vertebrates and could be used as an early detection tool of zoonotic pathogens

Clinical and molecular characteristics of sickle cell anemia in the northeast of Brazil

Beta S-globin gene (&#946;S-globin) haplotypes, markers for severe sickle cell anemia (SCA), and the alpha-thalassemia 2 gene 3.7 kb deletion (-&#945;2(3.7 kb) thal) along with demographic and clinical data were investigated in SCA outpatients (n = 125, 63 female and 62 male) in the Brazilian state of Bahia, which has a high prevalence SCA. PCR-RFLP showed that the Central African Republic/Benin (CAR/BEN, 51.2%) haplotype was most frequent, followed by the Benin/Benin (Ben/Ben, 28.8%). At least one CAR haplotype was present in every outpatient with a history of cerebrovascular accident. The Cameroon (Cam), Senegal (Sen) and Arab-India haplotypes occurred in small numbers, as did atypical haplotypes. Fetal hemoglobin (HbF, %) was unevenly distributed. Compared to those > 18 y, those aged < 18 y had had fewer erythrocyte transfusions and high HbF levels (12.3% ± 7.01 to 7.9% ± 4.36) but a higher frequency of spleen sequestration and pneumonia. Compared with normal &#945; - genes carriers values, the outpatients with -&#945;2(3.7 kb) thal (determined by PCR analysis) had significantly higher mean hemoglobin concentration (Hb) (8.3 ± 1.34 g/dL, p = 0.018) and packed cell volume (PCV = 27.1% ± 4.26, p = 0.019) but low mean corpuscular volume (MCV = 86.1 fL = 10-15 L ± 9.56, p = 0.0004) and mean corpuscular hemoglobin (MCH = 26.6% ± 4.60, p = 0.039)

The 2.1 Ga old Francevillian biota: biogenicity, taphonomy and biodiversity.

The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth’s surface environments following the first appreciable rise of free atmospheric oxygen concentrations ~2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rodshaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life