Thymus Dependency of the Immune Response in Murine Malaria

Studies were carried out to elucidate the role of the thymus and thymus derived lymphocyte population in the immune response of mice to malaria. Infection of normal CBA mice with the malaria parasite P. b. yoelii resulted in a mild, non fatal infection which lasted 15 to 16 days. Mice which recovered from a primary infection were immune to reinfection. Parasites could be demonstrated in the kidneys of such mice 3 to 4 weeks after recovery from infection, but were not detected in the peripheral blood and other tissues examined. In T cell deprived CBA mice P. b. yoelii infections followed a fulminant course and proved fatal within 30 to 35 days, thus demonstrating the absolute thymus dependency of these infections. In ATS treated mice P. b. yoelii infections followed an essentially similar pattern, but 30% of the treated mice recovered. Studies of fluorescent antibody levels and the histopathological changes in the spleens of normal and T cell deprived mice during infection showed that while normal CBA mice made high levels of IgG1, IgG2 and IgM antibodies and showed a strong and sustained germinal centre response, in T cell deprived mice the production of IgG1 antibodies was almost completely abolished and the germinal centre response was severely impaired. Reconstitution of T cell deprived mice with syngeneic thymus grafts resulted in restoration of immune responsiveness; the level of protective immunity and the germinal centre response correlated well with the degree of reconstitution achieved. The response of the CBA mouse to P. b. berghei, a progressive infection which proved fatal in 20 to 25 days, was also examined. These infections were found to provoke antibody and germinal centre responses intermediate between those elicited by P. b. yoelii infections in normal and T cell deprived mice. The T cell mitotic response to P. b. yoelii and P. b. berghei was defined in CBA/Lac - CBA/H.T6T6 mouse radiation chimaeras carrying a chromosomally distinguishable population of T cells. While P. b. yoelii provoked a rapid and sustained burst of T cell mitosis, the T cell response evoked by P. b. berghei was feeble and failed early in the infection despite the progressive parasitaemia. The functional state of the T cell pool was assayed by examining the responses of infected CBA mice to Oxazolone and of spleen cells to PHA (Phytohaemagglutinin). P. b. yoelii infected mice responded normally to oxazolone and despite a decrease in the proportion of PHA responsive cells there was a net increase in the absolute number of such cells in the spleen. In contrast, P. b. berghei infections resulted in marked depression of the response to oxazolone and of the absolute number of PHA responsive cells in the spleen. Both infections caused a decrease in the proportion of LPS responsive (B), cells, but when the response was computed on a per spleen basis there was no significant impairment of the response. Mechanisms of resistance in P. b. yoelii infections were further analysed by carrying out a series of cell and serum transfers from immune to non immune mice. While hyperimmune serum was protective against low parasite innocula, immune serum had no protective effect. Doses of hyperimmune serum which protected intact recipients completely, caused orly transient inhibition of infection in T cell deprived recipients. Immune spleen cells were the most effective in transferring immunity to normal and T cell deprived recipients. Treatment of these cells with anti theta antiserum did not remove their protective effect, suggesting that the effector cells in the immune spleen cell population were non T cells. These results ar e discussed in relation to their significance in effector and suppressor responses elicited during malarial infections

From Islamic Feminism to a Muslim Holistic Feminism

This article looks at the trajectory from secular feminism to Islamic feminism to Muslim holistic feminism, examining the changing meanings of ‘the secular’ and ‘the religious’ and the ways they intersect in the different modes of feminism. It contrasts the open, inclusive nature that typifies the secular feminisms Muslim and non?Muslims created in the twentieth century in contexts of anti?colonial struggle and early nation?state building with the communalism of the new Muslim holistic feminism now emerging in global space at a time when religious identity is fore?fronted and there is an international preoccupation with Muslim women's rights. The article argues that the communalisation of women's rights activism or the privileging of Muslim women's rights occurring at the global level and being exported to local terrain can be divisive and threatening national unity

Incident type 2 diabetes attributable to suboptimal diet in 184 countries

The global burden of diet-attributable type 2 diabetes (T2D) is not well established. This risk assessment model estimated T2D incidence among adults attributable to direct and body weight-mediated effects of 11 dietary factors in 184 countries in 1990 and 2018. In 2018, suboptimal intake of these dietary factors was estimated to be attributable to 14.1 million (95% uncertainty interval (UI), 13.814.4 million) incident T2D cases, representing 70.3% (68.871.8%) of new cases globally. Largest T2D burdens were attributable to insufficient whole-grain intake (26.1% (25.027.1%)), excess refined rice and wheat intake (24.6% (22.327.2%)) and excess processed meat intake (20.3% (18.323.5%)). Across regions, highest proportional burdens were in central and eastern Europe and central Asia (85.6% (83.487.7%)) and Latin America and the Caribbean (81.8% (80.183.4%)); and lowest proportional burdens were in South Asia (55.4% (52.160.7%)). Proportions of diet-attributable T2D were generally larger in men than in women and were inversely correlated with age. Diet-attributable T2D was generally larger among urban versus rural residents and higher versus lower educated individuals, except in high-income countries, central and eastern Europe and central Asia, where burdens were larger in rural residents and in lower educated individuals. Compared with 1990, global diet-attributable T2D increased by 2.6 absolute percentage points (8.6 million more cases) in 2018, with variation in these trends by world region and dietary factor. These findings inform nutritional priorities and clinical and public health planning to improve dietary quality and reduce T2D globally. (c) 2023, The Author(s)

Children's and adolescents' rising animal-source food intakes in 1990-2018 were impacted by age, region, parental education and urbanicity

Animal-source foods (ASF) provide nutrition for children and adolescents physical and cognitive development. Here, we use data from the Global Dietary Database and Bayesian hierarchical models to quantify global, regional and national ASF intakes between 1990 and 2018 by age group across 185 countries, representing 93% of the worlds child population. Mean ASF intake was 1.9 servings per day, representing 16% of children consuming at least three daily servings. Intake was similar between boys and girls, but higher among urban children with educated parents. Consumption varied by age from 0.6 at <1 year to 2.5 servings per day at 1519 years. Between 1990 and 2018, mean ASF intake increased by 0.5 servings per week, with increases in all regions except sub-Saharan Africa. In 2018, total ASF consumption was highest in Russia, Brazil, Mexico and Turkey, and lowest in Uganda, India, Kenya and Bangladesh. These findings can inform policy to address malnutrition through targeted ASF consumption programmes. (c) 2023, The Author(s)

Monoclonal auto-antibodies and sera of autoimmune patients react with Plasmodium falciparum and inhibit its in vitro growth

The relationship between autoimmunity and malaria is not well understood. To determine whether autoimmune responses have a protective role during malaria, we studied the pattern of reactivity to plasmodial antigens of sera from 93 patients with 14 different autoimmune diseases (AID) who were not previously exposed to malaria. Sera from patients with 13 different AID reacted against Plasmodium falciparum by indirect fluorescent antibody test with frequencies varying from 33-100%. In addition, sera from 37 AID patients were tested for reactivity against Plasmodium yoelii 17XNL and the asexual blood stage forms of three different P. falciparum strains. In general, the frequency of reactive sera was higher against young trophozoites than schizonts (p < 0.05 for 2 strains), indicating that the antigenic determinants targeted by the tested AID sera might be more highly expressed by the former stage. The ability of monoclonal auto-antibodies (auto-Ab) to inhibit P. falciparum growth in vitro was also tested. Thirteen of the 18 monoclonal auto-Ab tested (72%), but none of the control monoclonal antibodies, inhibited parasite growth, in some cases by greater than 40%. We conclude that autoimmune responses mediated by auto-Ab may present anti-plasmodial activity

The origin and composition of carbonatite-derived carbonate-bearing fluorapatite deposits

Carbonate-bearing fluorapatite rocks occur at over 30 globally distributed carbonatite complexes and represent a substantial potential supply of phosphorus for the fertiliser industry. However, the process(es) involved in forming carbonate-bearing fluorapatite at some carbonatites remain equivocal, with both hydrothermal and weathering mechanisms inferred. In this contribution, we compare the paragenesis and trace element contents of carbonate-bearing fluorapatite rocks from the Kovdor, Sokli, Bukusu, Catalão I and Glenover carbonatites in order to further understand their origin, as well as to comment upon the concentration of elements that may be deleterious to fertiliser production. The paragenesis of apatite from each deposit is broadly equivalent, comprising residual magmatic grains overgrown by several different stages of carbonate-bearing fluorapatite. The first forms epitactic overgrowths on residual magmatic grains, followed by the formation of massive apatite which, in turn, is cross-cut by late euhedral and colloform apatite generations. Compositionally, the paragenetic sequence corresponds to a substantial decrease in the concentration of rare earth elements (REE), Sr, Na and Th, with an increase in U and Cd. The carbonate-bearing fluorapatite exhibits a negative Ce anomaly, attributed to oxic conditions in a surficial environment and, in combination with the textural and compositional commonality, supports a weathering origin for these rocks. Carbonate-bearing fluorapatite has Th contents which are several orders of magnitude lower than magmatic apatite grains, potentially making such apatite a more environmentally attractive feedstock for the fertiliser industry. Uranium and cadmium contents are higher in carbonate-bearing fluorapatite than magmatic carbonatite apatite, but are much lower than most marine phosphorites