Month: September 2020

Most of these data come from controlled studies in which primaquine was given to G6PD deficient volunteers or normal recipients after transfusion of 51Cr-labelled GPD-deficient red cells, and from case reports of patients who developed hemolytic anaemia after receiving primaquine. Therefore, beyond the routine use of primaquine, comprehensive knowledge of the epidemiology of the G6PD deficiency by using reliable methods is needed. In this study, we have determined, for the first time, the normal reference values of G6PD enzymatic activity for both Cambodian males and females adults by using the quantitative spectrophotometric assay. Reference ranges generally used are derived from North American or European populations which may not be applicable to the Cambodian population. For this purpose, healthy individuals were selected with a normal range of hemoglobin concentration and a wild-type sequence in their G6PD gene. Surprisingly, we found that globally G6PD enzymatic activity was significantly higher in males compared to females while SB431542 previous reports showed no difference using the same methodology. Using these values, the global prevalence of G6PD deficiency in our sample population was 10.7%, ranging from 9.3% in the most southern village to 20% in the most northern village of the Pailin province. The cut-off point to diagnose G6PD deficiency both in Cambodian males and females was around 30% of the normal mean value. As expected, we found that the prevalence of G6PD deficiency was almost 2-fold higher in males compared to females. This proportion was similar to previous reports from Cambodia and in the bordering countries of Vietnam, Laos and Thailand.. Clinical manifestations include early onset of dry skin, pruritus, eczema with typical age-dependent distribution, and personal or family history of atopic disease. Knowledge of the pathophysiology behind the disease is emerging, several common genetic, environmental disease mechanisms and individual trigger factors being of importance. Central in the pathogenesis are combinations of inherited and acquired insults thought to alter epidermal structure. Which in turn has negative consequences for skinbarrier homeostasis. Impaired homeostasis of the skin leads to increased trans-epidermal water loss and changes in gene expression patterns and enzymatic activity. The most common monogenic disorder of keratinisation, ichthyosis vulgaris, is associated with AD and related atopic manifestations in up to 50%. This contrasts with X-linked recessive ichthyosis, which is due to mutations in the STS gene leading to accumulation of cholesterol sulphate in the stratum corneum. XLI occurs almost exclusively in males and may look almost indistinguishable from IV. However, skin histology and surface pH differ in the two conditions and no association to AD has been reported in XLI. In 2006, it was found that mutations in the FLG gene resulting in filaggrin dysfunction are the causative genetic factor for IV.

The phylogenetic relationship to a free-living sister group, acanthocephalans are attractive candidates as model organisms for studying host-parasite co-evolution. For example, the species distribution within the host illustrates that fish and birds are the most widely used definitive hosts, followed by mammals. It is, however, interesting to note that the oldest group of vertebrates, the fish, is not utilized by significantly more species than the youngest groups, the birds and mammals, indicating expansive adaptive radiation in these newly explored host groups. We are aware that the presented molecular phylogeny of the Acanthocephala is not yet comprehensive, and needs to be tested and validated by future studies. This requires further taxon sampling and ideally the inclusion of additional molecular markers. However, our data also demonstrate the preliminary nature of the acanthocephalan classification in general, especially of the derived echinorhynchids, the most common acanthocephalans in fish.

We suggest that the current state of knowledge warrants the identification of further morphological characters for a better understanding of the acanthocephalan diversity, perhaps best driven by more in-depth molecular phylogenetic studies. This will enable the mapping of more morphological characters onto the molecular trees, and redefining the higher level classification of the Acanthocephala. Acanthocephalans are attractive candidates as model organisms for studying the ecology and co-evolutionary history of parasitic life cycles in the marine ecosystem. However, the lack of phylogenetic studies and taxonomic identification of especially marine Acanthocephala prevents detailed comparison to other endoparasites. We do hope that our study will iniciate future research on the species composition, zoogeography and evolution of the phylum Acanthocephala, allowing comparisons to be made on the ecology of this taxon and other species groups such as the nematodes and cestodes that have diversified under similar conditions. The conversion of NADP+ to NADPH by G6PD is the ratelimiting reaction in the pentose phosphate pathway, the primary source of reducing potential for the glutathione redox flux which serves to as the primary protection of erythrocytes against oxidative stress.

Numerous drugs and chemicals such as primaquine, foods or stress can induce hemolytic anemia in G6PD-deficient individuals. G6PD deficiency is the Olaparib second most common hereditary enzyme deficiency which affects approximately 400 million people worldwide and is distributed in areas of current and previous endemic malaria. This human enzyme defect is caused by mutations in the G6PD gene located on chromosome Xq28; thus, transmission of the genetic defect is X linked. Hemizygote males are most affected and homozygous females least affected; both are prone to red cell haemolysis. Heterozygote females have mixed G6PD normal and deficient red cells and their susceptibility to haemolysis depends on the balance between the expression of the normal and abnormal X chromosomes.