Publications by authors named "Rifat S Rahman"

Despite the near ubiquitous presence of Ig-based antibodies in vertebrates, IgE is unique to mammals. How and why it emerged remains mysterious. IgE expression is greatly constrained compared to other IgH isotypes.

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Background: Few studies have examined the burden of postacute sequelae of coronavirus disease 2019 (COVID-19) (PASC) in low- and middle-income countries. We sought to characterize PASC with self-reported questionnaires and clinical examinations of end-organ function in Lima, Peru.

Methods: From January to July 2021, we recruited participants at least 8 weeks after COVID-19 diagnosis from a case registry in Lima, Peru.

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Allergen immunotherapy (AIT) is the only disease-modifying therapy for allergic disease. Through repeated inoculations of low doses of allergen-either as whole proteins or peptides-patients can achieve a homeostatic balance between inflammatory effectors induced and/or associated with allergen contact, and mediators of immunologic non-responsiveness, potentially leading to sustained clinical improvements. AIT for airborne/respiratory tract allergens and insect venoms have traditionally been supplied subcutaneously, but other routes and modalities of administration can also be effective.

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Artemisinin and its semisynthetic derivatives (ART) are fast acting, potent antimalarials; however, their use in malaria treatment is frequently confounded by recrudescences from bloodstream parasites that enter into and later reactivate from a dormant persister state. Here, we provide evidence that the mitochondria of dihydroartemisinin (DHA)-exposed persisters are dramatically altered and enlarged relative to the mitochondria of young, actively replicating ring forms. Restructured mitochondrial-nuclear associations and an altered metabolic state are consistent with stress from reactive oxygen species.

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Article Synopsis
  • The study investigates the drug response of Plasmodium falciparum strains to lumefantrine and mefloquine, focusing on genetic factors influencing susceptibility and resistance.
  • Drug response phenotypes were measured through half-maximal effective concentrations (ECs) and recovery days after lumefantrine exposure, revealing significant differences between two strains and their progeny.
  • The research found correlations between drug response and specific genetic polymorphisms in the PfMDR1, PfK13, and PfCRT proteins, suggesting these variations may impact the effectiveness of malaria treatments.
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Background: In Southeast Asia, people are often coinfected with different species of malaria (Plasmodium falciparum [Pf] and Plasmodium vivax [Pv]) as well as with multiple clones of the same species. Whether particular species or clones within mixed infections are more readily transmitted to mosquitoes remains unknown.

Methods: Laboratory-reared Anopheles dirus were fed on blood from 119 Pf-infected Cambodian adults, with 5950 dissected to evaluate for transmitted infection.

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Concerns about malaria parasite resistance to treatment with artemisinin drugs (ARTs) have grown with findings of prolonged parasite clearance s (>5 h) and their association with mutations in Kelch-propeller protein K13. Here, we describe a laboratory cross of K13 C580Y mutant with C580 wild-type parasites to investigate ART response phenotypes in vitro and in vivo. After genotyping >400 isolated progeny, we evaluated 20 recombinants in vitro: IC measurements of dihydroartemisinin were at similar low nanomolar levels for C580Y- and C580-type progeny (mean ratio, 1.

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Some Kelch mutations of the K13 protein confer increased survival to dihydroartemisinin (DHA)-treated ring-stage parasites. Here, we asked if K13 mutations affect a dormancy phenotype allowing parasites to survive DHA exposure and then sorbitol selection. Although recrudescence from dormancy differed between two distinct parasite lines, it was similar for isogenic lines carrying single-site substitutions in K13.

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