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1.
Nat Immunol ; 21(7): 790-801, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32424361

RESUMO

Plasmodium parasite-specific antibodies are critical for protection against malaria, yet the development of long-lived and effective humoral immunity against Plasmodium takes many years and multiple rounds of infection and cure. Here, we report that the rapid development of short-lived plasmablasts during experimental malaria unexpectedly hindered parasite control by impeding germinal center responses. Metabolic hyperactivity of plasmablasts resulted in nutrient deprivation of the germinal center reaction, limiting the generation of memory B cell and long-lived plasma cell responses. Therapeutic administration of a single amino acid to experimentally infected mice was sufficient to overcome the metabolic constraints imposed by plasmablasts and enhanced parasite clearance and the formation of protective humoral immune memory responses. Thus, our studies not only challenge the current model describing the role and function of blood-stage Plasmodium-induced plasmablasts but they also reveal new targets and strategies to improve anti-Plasmodium humoral immunity.


Assuntos
Imunidade Humoral , Malária/imunologia , Plasmócitos/metabolismo , Plasmodium falciparum/imunologia , Adolescente , Adulto , Aminoácidos/administração & dosagem , Aminoácidos/metabolismo , Animais , Anticorpos Antiprotozoários/sangue , Anticorpos Antiprotozoários/imunologia , Anticorpos Antiprotozoários/metabolismo , Antimaláricos/administração & dosagem , DNA de Protozoário/isolamento & purificação , Modelos Animais de Doenças , Centro Germinativo/citologia , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Interações Hospedeiro-Parasita/imunologia , Humanos , Malária/sangue , Malária/tratamento farmacológico , Malária/parasitologia , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Nutrientes/metabolismo , Plasmócitos/imunologia , Plasmócitos/parasitologia , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Estudo de Prova de Conceito , Adulto Jovem
2.
Clin Microbiol Rev ; 37(1): e0009423, 2024 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-38226640

RESUMO

Neisseria gonorrhoeae infection is an important public health issue, with an annual global incidence of 87 million. N. gonorrhoeae infection causes significant morbidity and can have serious long-term impacts on reproductive and neonatal health and may rarely cause life-threatening disease. Global rates of N. gonorrhoeae infection have increased over the past 20 years. Importantly, rates of antimicrobial resistance to key antimicrobials also continue to increase, with the United States Centers for Disease Control and Prevention identifying drug-resistant N. gonorrhoeae as an urgent threat to public health. This review summarizes the current evidence for N. gonorrhoeae vaccines, including historical clinical trials, key N. gonorrhoeae vaccine preclinical studies, and studies of the impact of Neisseria meningitidis vaccines on N. gonorrhoeae infection. A comprehensive survey of potential vaccine antigens, including those identified through traditional vaccine immunogenicity approaches, as well as those identified using more contemporary reverse vaccinology approaches, are also described. Finally, the potential epidemiological impacts of a N. gonorrhoeae vaccine and research priorities for further vaccine development are described.


Assuntos
Anti-Infecciosos , Gonorreia , Vacinas , Recém-Nascido , Humanos , Neisseria gonorrhoeae , Gonorreia/tratamento farmacológico , Gonorreia/epidemiologia , Gonorreia/prevenção & controle
3.
Immunity ; 45(2): 333-45, 2016 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-27533014

RESUMO

Many pathogens, including Plasmodium spp., exploit the interaction of programmed death-1 (PD-1) with PD-1-ligand-1 (PD-L1) to "deactivate" T cell functions, but the role of PD-L2 remains unclear. We studied malarial infections to understand the contribution of PD-L2 to immunity. Here we have shown that higher PD-L2 expression on blood dendritic cells, from Plasmodium falciparum-infected individuals, correlated with lower parasitemia. Mechanistic studies in mice showed that PD-L2 was indispensable for establishing effective CD4(+) T cell immunity against malaria, because it not only inhibited PD-L1 to PD-1 activity but also increased CD3 and inducible co-stimulator (ICOS) expression on T cells. Importantly, administration of soluble multimeric PD-L2 to mice with lethal malaria was sufficient to dramatically improve immunity and survival. These studies show immuno-regulation by PD-L2, which has the potential to be translated into an effective treatment for malaria and other diseases where T cell immunity is ineffective or short-lived due to PD-1-mediated signaling.


Assuntos
Antígeno B7-H1/metabolismo , Linfócitos T CD4-Positivos/imunologia , Células Dendríticas/imunologia , Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Proteína 2 Ligante de Morte Celular Programada 1/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Adamantano/análogos & derivados , Adamantano/uso terapêutico , Adulto , Animais , Antimaláricos/uso terapêutico , Antígeno B7-H1/genética , Células Cultivadas , Ensaios Clínicos como Assunto , Células Dendríticas/parasitologia , Feminino , Humanos , Imunidade Celular , Ativação Linfocitária , Malária Falciparum/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Parasitemia/imunologia , Peróxidos/uso terapêutico , Proteína 2 Ligante de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/genética , Pirimidinas/uso terapêutico , Triazóis/uso terapêutico , Adulto Jovem
4.
J Infect Dis ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38723177

RESUMO

Maintaining high affinity antibodies after vaccination may be important for long-lasting immunity to malaria, but data on induction and kinetics of affinity is lacking. In a Phase 1 malaria vaccine trial, antibody affinity increased following a second vaccination but declined substantially over 12-months, suggesting poor maintenance of high affinity antibodies.

5.
N Engl J Med ; 385(11): 971-981, 2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34496173

RESUMO

BACKGROUND: Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied. METHODS: In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients. RESULTS: We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group. CONCLUSIONS: In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).


Assuntos
Ambulâncias , Serviços Médicos de Emergência , AVC Isquêmico/tratamento farmacológico , Unidades Móveis de Saúde , Tempo para o Tratamento , Ativador de Plasminogênio Tecidual/uso terapêutico , Idoso , Avaliação da Deficiência , Feminino , Humanos , AVC Isquêmico/complicações , AVC Isquêmico/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Razão de Chances , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X
6.
Immunity ; 42(3): 580-90, 2015 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-25786180

RESUMO

Antibodies play major roles in immunity to malaria; however, a limited understanding of mechanisms mediating protection is a major barrier to vaccine development. We have demonstrated that acquired human anti-malarial antibodies promote complement deposition on the merozoite to mediate inhibition of erythrocyte invasion through C1q fixation and activation of the classical complement pathway. Antibody-mediated complement-dependent (Ab-C') inhibition was the predominant invasion-inhibitory activity of human antibodies; most antibodies were non-inhibitory without complement. Inhibitory activity was mediated predominately via C1q fixation, and merozoite surface proteins 1 and 2 were identified as major targets. Complement fixation by antibodies was very strongly associated with protection from both clinical malaria and high-density parasitemia in a prospective longitudinal study of children. Ab-C' inhibitory activity could be induced by human immunization with a candidate merozoite surface-protein vaccine. Our findings demonstrate that human anti-malarial antibodies have evolved to function by fixing complement for potent invasion-inhibitory activity and protective immunity.


Assuntos
Anticorpos Antiprotozoários/biossíntese , Complemento C1q/metabolismo , Vacinas Antimaláricas/imunologia , Malária Falciparum/prevenção & controle , Merozoítos/imunologia , Parasitemia/prevenção & controle , Plasmodium falciparum/imunologia , Adolescente , Animais , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Criança , Pré-Escolar , Testes de Fixação de Complemento , Via Clássica do Complemento , Eritrócitos/imunologia , Eritrócitos/parasitologia , Feminino , Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Imunoglobulina G/biossíntese , Vacinas Antimaláricas/administração & dosagem , Malária Falciparum/imunologia , Malária Falciparum/parasitologia , Masculino , Proteína 1 de Superfície de Merozoito/antagonistas & inibidores , Proteína 1 de Superfície de Merozoito/genética , Proteína 1 de Superfície de Merozoito/imunologia , Parasitemia/imunologia , Parasitemia/parasitologia , Estudos Prospectivos , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia
7.
J Pathol ; 260(3): 289-303, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37186300

RESUMO

Breast cancer invasion and metastasis result from a complex interplay between tumor cells and the tumor microenvironment (TME). Key oncogenic changes in the TME include aberrant synthesis, processing, and signaling of hyaluronan (HA). Hyaluronan-mediated motility receptor (RHAMM, CD168; HMMR) is an HA receptor enabling tumor cells to sense and respond to this aberrant TME during breast cancer progression. Previous studies have associated RHAMM expression with breast tumor progression; however, cause and effect mechanisms are incompletely established. Focused gene expression analysis of an internal breast cancer patient cohort confirmed that increased RHAMM expression correlates with aggressive clinicopathological features. To probe mechanisms, we developed a novel 27-gene RHAMM-related signature (RRS) by intersecting differentially expressed genes in lymph node (LN)-positive patient cases with the transcriptome of a RHAMM-dependent model of cell transformation, which we validated in an independent cohort. We demonstrate that the RRS predicts for poor survival and is enriched for cell cycle and TME-interaction pathways. Further analyses using CRISPR/Cas9-generated RHAMM-/- breast cancer cells provided direct evidence that RHAMM promotes invasion in vitro and in vivo. Immunohistochemistry studies highlighted heterogeneous RHAMM protein expression, and spatial transcriptomics associated the RRS with RHAMM-high microanatomic foci. We conclude that RHAMM upregulation leads to the formation of 'invasive niches', which are enriched in RRS-related pathways that drive invasion and could be targeted to limit invasive progression and improve patient outcomes. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/patologia , Ácido Hialurônico/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Receptores de Hialuronatos/metabolismo , Microambiente Tumoral
8.
J Hand Surg Am ; 49(6): 603-606, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38456864

RESUMO

The sensory-collapse test (formerly the scratch-collapse test) is a physical examination finding describing a momentary inhibition of external shoulder rotation following light stimulation of an injured nerve in the ipsilateral limb. Similar to other physical examination tests designed to interrogate nerve compression, such as the Phalen or Tinel tests, its test characteristics demonstrate variation. There remains speculation about the test's existence and anatomic basis. The literature of mammalian reflex physiology was reviewed with an emphasis on the sensory pathways from the upper extremity, the extrapyramidal system, and newly discovered pathways and concepts of nociception. A clear reflex pathway is described connecting the stimulus within an injured nerve through the afferent pathways in the fasciculus cuneatus in the spinal cord directly to the lateral reticulospinal tract, resulting in the inhibition of extensor muscles in the proximal limb (eg, shoulder) and activation of the limb flexors by acting upon alpha and gamma motor neurons. The sensory-collapse test represents a reflex pathway that teleologically provides a mechanism to protect an injured nerve by withdrawal toward the trunk and away from the noxious environment.


Assuntos
Reflexo , Humanos , Reflexo/fisiologia , Síndromes de Compressão Nervosa/fisiopatologia , Nociceptividade/fisiologia , Traumatismos dos Nervos Periféricos/fisiopatologia , Vias Aferentes/fisiologia
9.
J Fish Biol ; 104(3): 698-712, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37926443

RESUMO

Reservoir formation in a river system changes a lotic environment to more lacustrine conditions, with impacts throughout the ecosystem. In this study, a river reach containing typical salmonid riffle/run habitat was flooded to create a large, deep pool from June to September in each of 3 years. We test the hypothesis that juvenile Atlantic salmon (Salmo salar) with their preference for run/riffle habitats will respond to the transformation to a lentic environment by moving into adjacent lotic environments. Movements of juvenile Atlantic salmon were monitored using a combination of biotelemetry (radio- and passive integrated transponder-tagging) and electrofishing. Results showed that no tracked fish moved away from the created pool habitat. Mass-specific growth rates showed the created pool habitat resulted in net growth of juveniles. The results confirm that fish may not immediately (i.e., at least for an approximate 2 months) respond to rapid, large-scale habitat alterations by moving to find similar habitat conditions outside the altered habitat. This is most probably related to plasticity of behavior and habitat use, and no change in biological conditions to a point that would negatively impact fish growth and survival, for example food availability, competition, or predation. The results also support the hypothesis that the relative importance of physical habitat variables is not universal among streams and populations, therefore limiting the value of applying standard habitat suitability criteria and use.


Assuntos
Ecossistema , Salmo salar , Animais , Rios , Comportamento Predatório
10.
Clin Infect Dis ; 76(3): 506-512, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35731843

RESUMO

BACKGROUND: Blocking the transmission of parasites from humans to mosquitoes is a key component of malaria control. Tafenoquine exhibits activity against all stages of the malaria parasite and may have utility as a transmission blocking agent. We aimed to characterize the transmission blocking activity of low-dose tafenoquine. METHODS: Healthy adults were inoculated with Plasmodium falciparum 3D7-infected erythrocytes on day 0. Piperaquine was administered on days 9 and 11 to clear asexual parasitemia while allowing gametocyte development. A single 50-mg oral dose of tafenoquine was administered on day 25. Transmission was determined by enriched membrane feeding assays predose and at 1, 4, and 7 days postdose. Artemether-lumefantrine was administered following the final assay. Outcomes were the reduction in mosquito infection and gametocytemia after tafenoquine and safety parameters. RESULTS: Six participants were enrolled, and all were infective to mosquitoes before tafenoquine, with a median 86% (range, 22-98) of mosquitoes positive for oocysts and 57% (range, 4-92) positive for sporozoites. By day 4 after tafenoquine, the oocyst and sporozoite positivity rate had reduced by a median 35% (interquartile range [IQR]: 16-46) and 52% (IQR: 40-62), respectively, and by day 7, 81% (IQR 36-92) and 77% (IQR 52-98), respectively. The decline in gametocyte density after tafenoquine was not significant. No significant participant safety concerns were identified. CONCLUSIONS: Low-dose tafenoquine (50 mg) reduces P. falciparum transmission to mosquitoes, with a delay in effect.


Assuntos
Anopheles , Antimaláricos , Malária Falciparum , Malária , Adulto , Animais , Humanos , Plasmodium falciparum , Antimaláricos/efeitos adversos , Voluntários Saudáveis , Artemeter/farmacologia , Combinação Arteméter e Lumefantrina , Malária Falciparum/prevenção & controle , Esporozoítos , Anopheles/parasitologia
11.
Clin Infect Dis ; 76(11): 1919-1927, 2023 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-36795050

RESUMO

BACKGROUND: The long-acting 8-aminoquinoline tafenoquine may be a good candidate for mass drug administration if it exhibits sufficient blood-stage antimalarial activity at doses low enough to be tolerated by glucose 6-phosphate dehydrogenase (G6PD)-deficient individuals. METHODS: Healthy adults with normal levels of G6PD were inoculated with Plasmodium falciparum 3D7-infected erythrocytes on day 0. Different single oral doses of tafenoquine were administered on day 8. Parasitemia and concentrations of tafenoquine and the 5,6-orthoquinone metabolite in plasma/whole blood/urine were measured and standard safety assessments performed. Curative artemether-lumefantrine therapy was administered if parasite regrowth occurred, or on day 48 ± 2. Outcomes were parasite clearance kinetics, pharmacokinetic and pharmacokinetic/pharmacodynamic (PK/PD) parameters from modelling, and dose simulations in a theoretical endemic population. RESULTS: Twelve participants were inoculated and administered 200 mg (n = 3), 300 mg (n = 4), 400 mg (n = 2), or 600 mg (n = 3) tafenoquine. The parasite clearance half-life with 400 mg or 600 mg (5.4 hours and 4.2 hours, respectively) was faster than with 200 mg or 300 mg (11.8 hours and 9.6 hours, respectively). Parasite regrowth occurred after dosing with 200 mg (3/3 participants) and 300 mg (3/4 participants) but not after 400 mg or 600 mg. Simulations using the PK/PD model predicted that 460 mg and 540 mg would clear parasitaemia by a factor of 106 and 109, respectively, in a 60-kg adult. CONCLUSIONS: Although a single dose of tafenoquine exhibits potent P. falciparum blood-stage antimalarial activity, the estimated doses to effectively clear asexual parasitemia will require prior screening to exclude G6PD deficiency. Clinical Trials Registration. Australian and New Zealand Clinical Trials Registry (ACTRN12620000995976).


Assuntos
Antimaláricos , Malária Falciparum , Adulto , Humanos , Antimaláricos/efeitos adversos , Plasmodium falciparum , Voluntários Saudáveis , Parasitemia/tratamento farmacológico , Artemeter/farmacologia , Artemeter/uso terapêutico , Combinação Arteméter e Lumefantrina/uso terapêutico , Austrália , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia
12.
Breast Cancer Res ; 25(1): 74, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-37349798

RESUMO

BACKGROUND: RHAMM is a multifunctional protein that is upregulated in breast tumors, and the presence of strongly RHAMM+ve cancer cell subsets associates with elevated risk of peripheral metastasis. Experimentally, RHAMM impacts cell cycle progression and cell migration. However, the RHAMM functions that contribute to breast cancer metastasis are poorly understood. METHODS: We interrogated the metastatic functions of RHAMM using a loss-of-function approach by crossing the MMTV-PyMT mouse model of breast cancer susceptibility with Rhamm-/- mice. In vitro analyses of known RHAMM functions were performed using primary tumor cell cultures and MMTV-PyMT cell lines. Somatic mutations were identified using a mouse genotyping array. RNA-seq was performed to identify transcriptome changes resulting from Rhamm-loss, and SiRNA and CRISPR/Cas9 gene editing was used to establish cause and effect of survival mechanisms in vitro. RESULTS: Rhamm-loss does not alter initiation or growth of MMTV-PyMT-induced primary tumors but unexpectedly increases lung metastasis. Increased metastatic propensity with Rhamm-loss is not associated with obvious alterations in proliferation, epithelial plasticity, migration, invasion or genomic stability. SNV analyses identify positive selection of Rhamm-/- primary tumor clones that are enriched in lung metastases. Rhamm-/- tumor clones are characterized by an increased ability to survive with ROS-mediated DNA damage, which associates with blunted expression of interferon pathway and target genes, particularly those implicated in DNA damage-resistance. Mechanistic analyses show that ablating RHAMM expression in breast tumor cells by siRNA knockdown or CRISPR-Cas9 gene editing blunts interferon signaling activation by STING agonists and reduces STING agonist-induced apoptosis. The metastasis-specific effect of RHAMM expression-loss is linked to microenvironmental factors unique to tumor-bearing lung tissue, notably high ROS and TGFB levels. These factors promote STING-induced apoptosis of RHAMM+ve tumor cells to a significantly greater extent than RHAMM-ve comparators. As predicted by these results, colony size of Wildtype lung metastases is inversely related to RHAMM expression. CONCLUSION: RHAMM expression-loss blunts STING-IFN signaling, which offers growth advantages under specific microenvironmental conditions of lung tissue. These results provide mechanistic insight into factors controlling clonal survival/expansion of metastatic colonies and has translational potential for RHAMM expression as a marker of sensitivity to interferon therapy.


Assuntos
Neoplasias Pulmonares , Neoplasias Mamárias Animais , Animais , Espécies Reativas de Oxigênio , Neoplasias Mamárias Animais/genética , Neoplasias Pulmonares/patologia , RNA Interferente Pequeno , Dano ao DNA
13.
New Phytol ; 240(5): 1774-1787, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37743552

RESUMO

Evolutionary radiations of woody taxa within arid environments were made possible by multiple trait innovations including deep roots and embolism-resistant xylem, but little is known about how these traits have coevolved across the phylogeny of woody plants or how they jointly influence the distribution of species. We synthesized global trait and vegetation plot datasets to examine how rooting depth and xylem vulnerability across 188 woody plant species interact with aridity, precipitation seasonality, and water table depth to influence species occurrence probabilities across all biomes. Xylem resistance to embolism and rooting depth are independent woody plant traits that do not exhibit an interspecific trade-off. Resistant xylem and deep roots increase occurrence probabilities in arid, seasonal climates over deep water tables. Resistant xylem and shallow roots increase occurrence probabilities in arid, nonseasonal climates over deep water tables. Vulnerable xylem and deep roots increase occurrence probabilities in arid, nonseasonal climates over shallow water tables. Lastly, vulnerable xylem and shallow roots increase occurrence probabilities in humid climates. Each combination of trait values optimizes occurrence probabilities in unique environmental conditions. Responses of deeply rooted vegetation may be buffered if evaporative demand changes faster than water table depth under climate change.


Assuntos
Embolia , Água Subterrânea , Água/fisiologia , Madeira/fisiologia , Xilema/fisiologia , Plantas , Folhas de Planta/fisiologia , Secas
14.
Malar J ; 22(1): 199, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37381013

RESUMO

BACKGROUND: Evaluation of parasite clearance patterns in experimental human infection trials helps increase understanding of drug action. In a previously reported phase Ib trial of a new investigational anti-malarial drug M5717, parasite clearance showed a biphasic linear pattern: slow removal phase with a near flat clearance rate followed by a fast clearance phase with a steep slope. In this study three statistical approaches were implemented and compared to estimate the parasite clearance rate for each phase and the time point corresponding to the change of clearance rates (changepoint between the two phases). METHODS: Data using three M5717 doses 150 mg (n = 6), 400 mg (n = 8), 800 mg (n = 8) were used to estimate biphasic clearance rates. Three models were investigated: firstly, segmented mixed models with estimated changepoint-models with/without random effects in various parameters were compared. Secondly, a segmented mixed model using grid search-this method is similar to the first except that changepoints were not estimated, instead they were selected based on model fit from given candidate values. Thirdly, a two-stage approach whereby a segmented regression model fit to each participant followed by a meta-analysis method. Hourly rate of parasite clearance (HRPC) interpreted as the percentage of parasites removed each hour was calculated. RESULTS: The three models generated similar results. Using segmented mixed models, the estimated changepoints after treatment in hours (95% CI) were: 150 mg: 33.9 (28.7, 39.1); 400 mg: 57.4 (52.5, 62.4); and 800 mg: 52.8 (47.4, 58.1). For all three treatment groups, there was nearly no clearance before the changepoints, but rapid clearance in the second phase (HRPC [95% CI]): 150 mg: 16.8% (14.3, 19.1%); 400 mg: 18.6% (16.0, 21.1%); and 800 mg: 11.7% (9.3, 14.1%). CONCLUSIONS: All three statistical approaches are effective tools to characterize the bi-phasic clearance of M5717 in the phase 1b experimental Plasmodium falciparum malaria human infection study. The statistical approaches produced similar results to estimate the two-phase clearance rates and the changepoint for each treatment dose of M5717. However, the segmented mixed model with random changepoints has several advantages: it is computationally efficient, provides precision for changepoint estimates and is robust concerning outlying datapoints or individuals.


Assuntos
Antimaláricos , Malária Falciparum , Parasitos , Humanos , Animais , Antimaláricos/uso terapêutico , Malária Falciparum/tratamento farmacológico , Cinética
15.
Nature ; 542(7639): 101-104, 2017 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-28117441

RESUMO

Elucidation of the evolutionary history and interrelatedness of Plasmodium species that infect humans has been hampered by a lack of genetic information for three human-infective species: P. malariae and two P. ovale species (P. o. curtisi and P. o. wallikeri). These species are prevalent across most regions in which malaria is endemic and are often undetectable by light microscopy, rendering their study in human populations difficult. The exact evolutionary relationship of these species to the other human-infective species has been contested. Using a new reference genome for P. malariae and a manually curated draft P. o. curtisi genome, we are now able to accurately place these species within the Plasmodium phylogeny. Sequencing of a P. malariae relative that infects chimpanzees reveals similar signatures of selection in the P. malariae lineage to another Plasmodium lineage shown to be capable of colonization of both human and chimpanzee hosts. Molecular dating suggests that these host adaptations occurred over similar evolutionary timescales. In addition to the core genome that is conserved between species, differences in gene content can be linked to their specific biology. The genome suggests that P. malariae expresses a family of heterodimeric proteins on its surface that have structural similarities to a protein crucial for invasion of red blood cells. The data presented here provide insight into the evolution of the Plasmodium genus as a whole.


Assuntos
Evolução Molecular , Genoma/genética , Malária/parasitologia , Plasmodium malariae/genética , Plasmodium ovale/genética , Animais , Eritrócitos/parasitologia , Feminino , Genômica , Humanos , Pan troglodytes/parasitologia , Filogenia
16.
J Paediatr Child Health ; 59(12): 1296-1303, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37920140

RESUMO

AIM: Here, we present results of a survey of scabies prevalence in childcare centres and primary schools in Auckland. METHODS: Children whose parents agreed to take part in participating centres in the Auckland region were examined for scabies by general practitioners and given questionnaires of relevant symptoms. Diagnoses of clinical or suspected scabies were made according to the International Alliance for the Control of Scabies (IACS) criteria. The survey was a stratified random sample of schools and early childcare centres. A quantitative polymerase chain reaction (PCR) test was also used to complement the IACS criteria. RESULTS: A total of 181 children were examined, with 145 children with history information, 16 of whom (11.0%) met the criteria for 'clinical' or 'suspected' scabies. Weighted analysis, accounting for the survey design, indicated that the prevalence of scabies in early childcare centres was 13.2% (95% CI: 4.3 to 22.1), with no school-aged children fulfilling these criteria. A higher proportion had clinical signs of scabies with 23 (12.7%) having typical scabies lesions and a further 43 (23.8%) had atypical lesions. A total of 64 PCR tests were taken and 15 (23%) were positive. None of these cases were receiving treatment for scabies. Five were undergoing topical skin treatment: three with topical steroid and two with calamine lotion. CONCLUSIONS: The prevalence of children with scabies is high in early childcare centres in Auckland. Misdiagnosis is suggested by several PCR positive cases being treated by topical agents used to treat other skin conditions.


Assuntos
Impetigo , Escabiose , Criança , Humanos , Escabiose/diagnóstico , Escabiose/epidemiologia , Impetigo/diagnóstico , Impetigo/tratamento farmacológico , Impetigo/epidemiologia , Prevalência , Instituições Acadêmicas , Inquéritos e Questionários , Erros de Diagnóstico
17.
J Pediatr Orthop ; 43(8): 505-510, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37390499

RESUMO

BACKGROUND: Various lateral humeral condyle fracture (LHCF) classification systems have been in use since the 1950s, but limited research exists on their reliability. The most widely utilized, yet un-validated system is that of Jakob and colleagues. The purpose of the current study was to analyze the reliability of a modified Jakob classification system and its value in guiding treatment either with or without arthrography. METHODS: Interrater and intrarater reliability studies were performed using radiographs and arthrograms from 32 LHCFs. Radiographs were presented to 3 pediatric orthopaedic surgeons and 6 pediatric orthopaedic surgery residents who were asked to classify the fractures according to a modified Jakob classification system, enunciate their treatment plan, and whether they would utilize arthrography. Classification was repeated within 2 weeks to assess intrarater reliability. The treatment plan using radiographs only and radiographs with arthrography were compared at both rating points. RESULTS: The modified Jakob system had excellent interrater reliability using only radiographs with a kappa value of 0.82 and an overall agreement of 86%. The average kappa for intrarater reliability using only radiographs was 0.88 with a range of 0.79 to 1.00 and an average overall agreement of 91% with a range of 84% to 100%. Interrater and intrarater reliability was poorer using both radiographs and arthrography. On average, arthrography changed the treatment plan in 8% of cases. CONCLUSIONS: The modified Jakob classification system proved to be a reliable classification system for LHCFs, independent of arthrography, given the excellent free-marginal multirater kappa values. LEVEL OF EVIDENCE: Level III-diagnostic.


Assuntos
Fraturas Distais do Úmero , Fraturas do Úmero , Humanos , Criança , Artrografia , Reprodutibilidade dos Testes , Fraturas do Úmero/diagnóstico por imagem , Fraturas do Úmero/terapia , Radiografia , Variações Dependentes do Observador
18.
Pediatr Phys Ther ; 35(1): 57-64, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36638029

RESUMO

PURPOSE: To characterize and examine the variability in receipt of inpatient (IP) physical therapy after lower extremity (LE) orthopedic surgery for individuals with cerebral palsy (CP) across hospital-level (region, bed size) and individual characteristics (gender, age, race/ethnicity, insurance type, technology dependency, and surgical burden). METHODS: We retrospectively analyzed physical therapy billing data of children with CP who had LE orthopedic surgery from October 1, 2015, through September 30, 2017, from the Pediatric Health Information Services (PHIS) database. RESULTS: Seventy-five percent of individuals received IP physical therapy during the hospital stay. Individuals from the South and West and those who were technology dependent were less likely to receive IP therapy. Those at large hospitals, aged 11 to 14 years, and with a high surgical burden were more likely to receive therapy. CONCLUSIONS: Results provide a starting point for future research on the discrepancies of acute physical therapy services in children diagnosed with CP. (Supplemental digital content video abstract available at: http://links.lww.com/PPT/A420).


Assuntos
Paralisia Cerebral , Humanos , Criança , Estudos Retrospectivos , Paralisia Cerebral/cirurgia , Paralisia Cerebral/reabilitação , Pacientes Internados , Modalidades de Fisioterapia , Extremidade Inferior/cirurgia
19.
J Infect Dis ; 225(6): 1062-1069, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-32479608

RESUMO

BACKGROUND: Interventions that effectively target Plasmodium vivax are critical for the future control and elimination of malaria. We conducted a P. vivax volunteer infection study to characterize the antimalarial activity of artefenomel, a new drug candidate. METHODS: Eight healthy, malaria-naive participants were intravenously inoculated with blood-stage P. vivax and subsequently received a single oral 200-mg dose of artefenomel. Blood samples were collected to monitor the development and clearance of parasitemia, and plasma artefenomel concentration. Mosquito feeding assays were conducted before artefenomel dosing to investigate parasite transmissibility. RESULTS: Initial parasite clearance occurred in all participants after artefenomel administration (log10 parasite reduction ratio over 48 hours, 1.67; parasite clearance half-life, 8.67 hours). Recrudescence occurred in 7 participants 11-14 days after dosing. A minimum inhibitory concentration of 0.62 ng/mL and minimum parasiticidal concentration that achieves 90% of maximum effect of 0.83 ng/mL were estimated, and a single 300-mg dose was predicted to clear 109 parasites per milliliter with 95% certainty. Gametocytemia developed in all participants and was cleared 4-8 days after dosing. At peak gametocytemia, 75% of participants were infectious to mosquitoes. CONCLUSIONS: The in vivo antimalarial activity of artefenomel supports its further clinical development as a treatment for P. vivax malaria. CLINICAL TRIALS REGISTRATION: NCT02573857.


Assuntos
Antimaláricos , Culicidae , Antagonistas do Ácido Fólico , Malária Falciparum , Malária Vivax , Parasitos , Adamantano/análogos & derivados , Animais , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Antagonistas do Ácido Fólico/farmacologia , Humanos , Malária Falciparum/parasitologia , Malária Vivax/tratamento farmacológico , Peróxidos , Plasmodium falciparum , Plasmodium vivax
20.
Am J Psychoanal ; 83(1): 1-11, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36782041

RESUMO

Beginning in 1920 and in keeping with Freud's sustained encouragement, the first two generations of European psychoanalysts initiated a progressive mental health movement by offering very low cost and free psychoanalytic services that were in harmony with Austrian social democratic and socialist political leaders' commitment to societal reforms in light of the economic and social inequities after the First World War. This synthesis of biographical and autobiographical accounts of early Freudian, Ego Psychology and Neo-Freudian theorists' contributions highlights their consideration of the effects of social injustice as central challenges to the development of psychological growth.


Assuntos
Teoria Freudiana , Terapia Psicanalítica , Humanos , Saúde Mental , Áustria , Teoria Psicanalítica
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