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1.
Am J Perinatol ; 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39271113

RESUMO

OBJECTIVE: We aimed to summarize the available evidence examining the association between prenatal ultrasound findings and adverse fetal, obstetric, and neonatal outcomes in pregnancies complicated by type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) and to evaluate whether the predictive value of ultrasound findings for adverse outcomes varies between T1DM and T2DM pregnancies. DATA SOURCES: We conducted a systematic review of the existing literature through August 12, 2024. METHODS OF STUDY SELECTION: We included articles in English that reported associations between ultrasound findings and fetal, obstetric, and neonatal outcomes in pregnant people with T1DM and T2DM. Two independent reviewers examined articles at the abstract level and, if eligible, at the full-text level; disagreements were adjudicated by a third reviewer. TABULATION, INTEGRATION, AND RESULTS: Of the 2,088 unique citations reviewed, 12 studies met the inclusion criteria describing associations between ultrasound findings and fetal, obstetric, and neonatal outcomes among a total of 1,165 pregnant people with T1DM and 489 pregnant people with T2DM. Most studies (10/12) examined the association between ultrasound measures of growth, including estimated fetal weight (EFW) and its individual components, abdominal wall thickness, head circumference to abdominal circumference (HC/AC) ratio, and birthweight, large for gestational age (LGA) or small for gestational age (SGA). Studies did not examine stillbirth, neonatal demise, or maternal outcomes other than cesarean section. CONCLUSION: This systematic review synthesizes the available literature on ultrasound risk markers of adverse fetal, obstetric, and neonatal outcomes separately in pregnant people with T1DM and T2DM. We identified very few studies that distinguished between pregnant people with T1DM and T2DM, and the majority focused on surrogate outcomes (e.g., LGA, SGA) of morbidity. Our findings highlight the need for further studies investigating these distinct diseases to provide evidence for antenatal management recommendations.

2.
bioRxiv ; 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-38105992

RESUMO

Artemisinins have been a cornerstone of malaria control, but resistance in Plasmodium falciparum, due to mutations in the Kelch13 (K13) protein, threaten these advances. Artemisinin exposure results in a dynamic transcriptional response across multiple pathways, but most work has focused on ring stages and ex vivo transcriptional analysis. We applied single cell RNAseq to two unsynchronized coisogenic parasite lines (K13C580 and K13580Y) over 6 hrs after a pulse exposure to dihydroartemisinin (DHA). Transcription was altered across all stages, with the greatest occurring at the trophozoite and ring stage in both lines. This response involved the arrest of metabolic processes, support for a dormancy phenomenon upon treatment, and the enhancement of protein trafficking and the unfolded protein response. While similar, the response was consistent across stages in K13580Y, with enhanced parasite survival to drug induced stress. Increased surface protein expression was seen in K13580Y parasites at baseline and upon drug exposure, highlighted by the increased expression of PfEMP1 and GARP, a potential therapeutic target. Antibody targeting GARP maintained anti-parasitic efficacy in K13580Y parasites. This work provides single cell insight of gene transcription across all life cycle stages revealing transcriptional changes that could initiate a dormancy state and mediate survival upon treatment.

3.
medRxiv ; 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36865135

RESUMO

The Zanzibar archipelago of Tanzania has become a low-transmission area for Plasmodium falciparum. Despite being considered an area of pre-elimination for years, achieving elimination has been difficult, likely due to a combination of imported infections from mainland Tanzania, and continued local transmission. To shed light on these sources of transmission, we applied highly multiplexed genotyping utilizing molecular inversion probes to characterize the genetic relatedness of 282 P. falciparum isolates collected across Zanzibar and in Bagamoyo District on the coastal mainland from 2016-2018. Overall, parasite populations on the coastal mainland and Zanzibar archipelago remain highly related. However, parasite isolates from Zanzibar exhibit population microstructure due to rapid decay of parasite relatedness over very short distances. This, along with highly related pairs within shehias, suggests ongoing low level local transmission. We also identified highly related parasites across shehias that reflect human mobility on the main island of Unguja and identified a cluster of highly related parasites, suggestive of an outbreak, in the Micheweni district on Pemba island. Parasites in asymptomatic infections demonstrated higher complexity of infection than those in symptomatic infections, but have similar core genomes. Our data support importation as a main source of genetic diversity and contribution to the parasite population on Zanzibar, but they also show local outbreak clusters where targeted interventions are essential to block local transmission. These results highlight the need for preventive measures against imported malaria and enhanced control measures in areas that remain receptive for malaria reemergence due to susceptible hosts and competent vectors.

4.
Elife ; 122024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38935423

RESUMO

Background: The Zanzibar archipelago of Tanzania has become a low-transmission area for Plasmodium falciparum. Despite being considered an area of pre-elimination for years, achieving elimination has been difficult, likely due to a combination of imported infections from mainland Tanzania and continued local transmission. Methods: To shed light on these sources of transmission, we applied highly multiplexed genotyping utilizing molecular inversion probes to characterize the genetic relatedness of 282 P. falciparum isolates collected across Zanzibar and in Bagamoyo district on the coastal mainland from 2016 to 2018. Results: Overall, parasite populations on the coastal mainland and Zanzibar archipelago remain highly related. However, parasite isolates from Zanzibar exhibit population microstructure due to the rapid decay of parasite relatedness over very short distances. This, along with highly related pairs within shehias, suggests ongoing low-level local transmission. We also identified highly related parasites across shehias that reflect human mobility on the main island of Unguja and identified a cluster of highly related parasites, suggestive of an outbreak, in the Micheweni district on Pemba island. Parasites in asymptomatic infections demonstrated higher complexity of infection than those in symptomatic infections, but have similar core genomes. Conclusions: Our data support importation as a main source of genetic diversity and contribution to the parasite population in Zanzibar, but they also show local outbreak clusters where targeted interventions are essential to block local transmission. These results highlight the need for preventive measures against imported malaria and enhanced control measures in areas that remain receptive to malaria reemergence due to susceptible hosts and competent vectors. Funding: This research was funded by the National Institutes of Health, grants R01AI121558, R01AI137395, R01AI155730, F30AI143172, and K24AI134990. Funding was also contributed from the Swedish Research Council, Erling-Persson Family Foundation, and the Yang Fund. RV acknowledges funding from the MRC Centre for Global Infectious Disease Analysis (reference MR/R015600/1), jointly funded by the UK Medical Research Council (MRC) and the UK Foreign, Commonwealth & Development Office (FCDO), under the MRC/FCDO Concordat agreement and is also part of the EDCTP2 program supported by the European Union. RV also acknowledges funding by Community Jameel.


Assuntos
Malária Falciparum , Plasmodium falciparum , Tanzânia/epidemiologia , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Malária Falciparum/transmissão , Malária Falciparum/parasitologia , Malária Falciparum/epidemiologia , Humanos , Genótipo
5.
mBio ; 12(3): e0075321, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34044591

RESUMO

Artemisinin and its semisynthetic derivatives (ART) are fast acting, potent antimalarials; however, their use in malaria treatment is frequently confounded by recrudescences from bloodstream Plasmodium 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. New contacts between the mitochondria and nuclei may support communication pathways of mitochondrial retrograde signaling, resulting in transcriptional changes in the nucleus as a survival response. Further characterization of the organelle communication and metabolic dependencies of persisters may suggest strategies to combat recrudescences of malaria after treatment. IMPORTANCE The major first-line treatment for malaria, especially the deadliest form caused by Plasmodium falciparum, is combination therapy with an artemisinin-based drug (ART) plus a partner drug to assure complete cure. Without an effective partner drug, ART administration alone can fail because of the ability of small populations of blood-stage malaria parasites to enter into a dormant state and survive repeated treatments for a week or more. Understanding the nature of parasites in dormancy (persisters) and their ability to wake and reestablish actively propagating parasitemias (recrudesce) after ART exposure may suggest strategies to improve treatment outcomes and counter the threats posed by parasites that develop resistance to partner drugs. Here, we show that persisters have dramatically altered mitochondria and mitochondrial-nuclear interactions associated with features of metabolic quiescence. Restructured associations between the mitochondria and nuclei may support signaling pathways that enable the ART survival responses of dormancy.


Assuntos
Antimaláricos/farmacologia , Artemisininas/farmacologia , Núcleo Celular/metabolismo , Mitocôndrias/metabolismo , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/fisiologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/parasitologia , Humanos , Malária Falciparum/parasitologia
6.
Trends Parasitol ; 36(9): 735-744, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32586776

RESUMO

Artemisinin and its derivatives (ART) are crucial first-line antimalarial drugs that rapidly clear parasitemia, but recrudescences of the infection frequently follow ART monotherapy. For this reason, ART must be used in combination with one or more partner drugs that ensure complete cure. The ability of malaria parasites to survive ART monotherapy may relate to an innate growth bistability phenomenon whereby a fraction of the drug-exposed population enters into metabolic quiescence (dormancy) as persister forms. Characterization of the events that underlie entry and waking from persistence may lead to lasting breakthroughs in malaria chemotherapy that can prevent recrudescences and protect the future of ART-based combination therapies.


Assuntos
Artemisininas/farmacologia , Resistência a Medicamentos , Plasmodium/efeitos dos fármacos , Antimaláricos/farmacologia , Humanos , Recidiva
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