Evidence for the early emergence of piperaquine-resistant Plasmodium falciparum malaria and modeling strategies to mitigate resistance.

Multidrug-resistant Plasmodium falciparum parasites have emerged in Cambodia and neighboring countries in Southeast Asia, compromising the efficacy of first-line antimalarial combinations. Dihydroartemisinin + piperaquine (PPQ) treatment failure rates have risen to as high as 50% in some areas in this region. For PPQ, resistance is driven primarily by a series of mutant alleles of the P. falciparum chloroquine resistance transporter (PfCRT). PPQ resistance was reported in China three decades earlier, but the molecular driver remained unknown. Herein, we identify a PPQ-resistant pfcrt allele (China C) from Yunnan Province, China, whose genotypic lineage is distinct from the PPQ-resistant pfcrt alleles currently observed in Cambodia. Combining gene editing and competitive growth assays, we report that PfCRT China C confers moderate PPQ resistance while re-sensitizing parasites to chloroquine (CQ) and incurring a fitness cost that manifests as a reduced rate of parasite growth. PPQ transport assays using purified PfCRT isoforms, combined with molecular dynamics simulations, highlight differences in drug transport kinetics and in this transporter's central cavity conformation between China C and the current Southeast Asian PPQ-resistant isoforms. We also report a novel computational model that incorporates empirically determined fitness landscapes at varying drug concentrations, combined with antimalarial susceptibility profiles, mutation rates, and drug pharmacokinetics. Our simulations with PPQ-resistant or -sensitive parasite lines predict that a three-day regimen of PPQ combined with CQ can effectively clear infections and prevent the evolution of PfCRT variants. This work suggests that including CQ in combination therapies could be effective in suppressing the evolution of PfCRT-mediated multidrug resistance in regions where PPQ has lost efficacy.

Evaluation of fluid absorption during flexible ureteroscopy in an in vivo porcine model.

OBJECTIVE: To evaluate the relationship between renal pelvis pressure and fluid absorption during ureteroscopy (URS) in a live porcine model. MATERIALS AND METHODS: Flexible URS (fURS) was performed in anaesthetised female Yorkshire pigs. Prior to performing fURS, a 0.3556-mm (0.014″) pressure-sensing guidewire (Comet™, Boston Scientific) was placed to monitor renal pelvis pressure. A simulated fURS procedure was then performed for 1 h. Infusion of irrigation fluid (5% ethanol in saline) at target renal pelvis pressures (37-150 mmHg) was maintained for 1 h using a pressure bag and real-time feedback from the pressure-sensing guidewire. Venous blood was sampled every 10 min. The volume of irrigation fluid absorbed was estimated with established equations. RESULTS: A URS procedure was performed in vivo in 18 porcine kidneys and the volume of irrigation fluid absorbed during the 1 h URS was calculated. The mean (SD) volume of irrigation fluid absorbed after 1 h of simulated URS was 7.6 (5.7), 10.8 (7.1), 26.0 (15.8), and 56.8 (22.3) mL at renal pelvis pressures of 37, 55, 75, and 150 mmHg, respectively. Compared with URS with renal pelvis pressure of 37 mmHg, the volume of fluid absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (P = 0.026 and P = 0.047, respectively). In addition, compared with URS with renal pelvis pressure of 37 mmHg, the rate of absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (both P < 0.001). CONCLUSION: In this study of an in vivo porcine model of URS, increasing renal pelvis pressures during URS were associated with increases in irrigation fluid absorption and increases in the rate of fluid absorption.

Injectable Colloidal Hydrogels of N-Vinylformamide Microgels Dispersed in Covalently Interlinked pH-Responsive Methacrylic Acid-Based Microgels.

Injectable hydrogels offer great potential to augment damaged or degenerated soft tissues. A key criterion for such gels is that their modulus is as close as possible to that of the target tissue. The majority of synthetic hydrogels have used low molecular weight polymer chains which may cause problems if they diffuse away from the injection site and/or increase the local osmotic pressure. We previously introduced a different approach of injecting preformed ultra-high molecular weight pH-responsive microgels (MGs) that interlink to form hydrogels. MGs are crosslinked polymer colloid particles that swell when the pH approaches the particle pKa. These colloidal hydrogels are termed doubly crosslinked microgels (DX MGs). The gel moduli of previous DX MGs were much greater than that reported for human nucleus pulposus (NP) tissue of the spinal intervertebral disk. Here, we replace some of the pH-responsive poly(ethyl acrylate-co-methacrylic acid) (PEA-MAA) MGs with hydrophilic non-ionic MGs based on poly(N-vinylformamide) (NVF). We investigate the morphology and mechanical properties of these new injectable composite DX MGs and show that the mechanical properties can be tuned by systematically varying the NVF MG content. Using this approach, the gel moduli close to that for NP tissue are achieved. These injectable new pH-responsive gels exhibit low cytotoxicity. Our work provides a potential new system for minimally invasive intervertebral disk augmentation.

Mutant PfCRT Can Mediate Piperaquine Resistance in African Plasmodium falciparum With Reduced Fitness and Increased Susceptibility to Other Antimalarials.

BACKGROUND: Additional therapeutic strategies could benefit efforts to reverse the recent increase in malaria cases in sub-Saharan Africa, which mostly affects young children. A primary candidate is dihydroartemisinin + piperaquine (DHA + PPQ), which is effective for uncomplicated malaria treatment, seasonal malaria chemoprevention, and intermittent preventive treatment. In Southeast Asia, Plasmodium falciparum parasites acquired PPQ resistance, mediated primarily by mutations in the P falciparum chloroquine resistance transporter PfCRT. The recent emergence in Africa of DHA-resistant parasites creates an imperative to assess whether PPQ resistance could emerge in African parasites with distinct PfCRT isoforms. METHODS: We edited 2 PfCRT mutations known to mediate high-grade PPQ resistance in Southeast Asia into GB4 parasites from Gabon. Gene-edited clones were profiled in antimalarial concentration-response and fitness assays. RESULTS: The PfCRT F145I mutation mediated moderate PPQ resistance in GB4 parasites but with a substantial fitness cost. No resistance was observed with the PfCRT G353V mutant. Both edited clones became significantly more susceptible to amodiaquine, chloroquine, and quinine. CONCLUSIONS: A single PfCRT mutation can mediate PPQ resistance in GB4 parasites, but with a growth defect that may preclude its spread without further genetic adaptations. Our findings support regional use of drug combinations that exert opposing selective pressures on PfCRT.

Highly Stretchable Conductive Covalent Coacervate Gels for Electronic Skin.

Highly stretchable electrically conductive hydrogels have been extensively researched in recent years, especially for applications in strain and pressure sensing, electronic skin, and implantable bioelectronic devices. Herein, we present a new cross-linked complex coacervate approach to prepare conductive hydrogels that are both highly stretchable and compressive. The gels involve a complex coacervate between carboxylated nanogels and branched poly(ethylene imine), whereby the latter is covalently cross-linked by poly(ethylene glycol) diglycidyl ether (PEGDGE). Inclusion of graphene nanoplatelets (Gnp) provides electrical conductivity as well as tensile and compressive strain-sensing capability to the hydrogels. We demonstrate that judicious selection of the molecular weight of the PEGDGE cross-linker enables the mechanical properties of these hydrogels to be tuned. Indeed, the gels prepared with a PEGDGE molecular weight of 6000 g/mol defy the general rule that toughness decreases as strength increases. The conductive hydrogels achieve a compressive strength of 25 MPa and a stretchability of up to 1500%. These new gels are both adhesive and conformal. They provide a self-healable electronic circuit, respond rapidly to human motion, and can act as strain-dependent sensors while exhibiting low cytotoxicity. Our new approach to conductive gel preparation is efficient, involves only preformed components, and is scalable.

Relationship Between Body Composition and Death in Patients with COVID-19 Differs Based on the Presence of Gastrointestinal Symptoms.

BACKGROUND: Patients with SARS-CoV-2 who present with gastrointestinal symptoms have a milder clinical course than those who do not. Risk factors for severe COVID-19 disease include increased adiposity and sarcopenia. AIMS: To determine whether body composition risk factors are associated with worse outcomes among patients with gastrointestinal symptoms. METHODS: This was a retrospective study of hospitalized patients with COVID-19 who underwent abdominal CT scan for clinical indications. Abdominal body composition measures including skeletal muscle index (SMI), intramuscular adipose tissue index (IMATI), visceral adipose tissue index (VATI), subcutaneous adipose tissue index (SATI), visceral-to-subcutaneous adipose tissue ratio (VAT/SAT ratio), and liver and spleen attenuation were collected. The association between body composition measurements and 30-day mortality was evaluated in patients with and without gastrointestinal symptoms at the time of positive SARS-CoV-2 test. RESULTS: Abdominal CT scans of 190 patients with COVID-19 were evaluated. Gastrointestinal symptoms including nausea, vomiting, diarrhea, or abdominal pain were present in 117 (62%). Among patients without gastrointestinal symptoms, those who died had greater IMATI (p = 0.049), less SMI (p = 0.010), and a trend toward a greater VAT/SAT ratio. Among patients with gastrointestinal symptoms, those who died had significantly greater IMATI (p = 0.025) but no differences in other measures. CONCLUSIONS: Among patients with COVID-19, those without gastrointestinal symptoms showed the expected associations between mortality and low SMI, high IMATI, and trend toward higher VAT/SAT ratio, but those with gastrointestinal symptoms did not. Future studies should explore the mechanisms for the altered disease course in patients with COVID-19 who present with gastrointestinal symptoms.

Maternal and neonatal outcomes among incarcerated women who gave birth in custody.

BACKGROUND: In the United States, the population of incarcerated women has increased by more than 600% since the 1980s. With this rise, correctional facilities have faced new challenges meeting the health care needs of women, especially those who are pregnant. This retrospective cohort study sought to describe five indicators of maternal and neonatal health among women who gave birth in custody, and to compare outcomes among incarcerated women who did and did not receive enhanced pregnancy support. METHODS: We used deidentified electronic health records (EHRs) to examine maternal and neonatal birth outcomes (ie, mode of birth, low birthweight, preterm birth, APGAR score, NICU admission) among women who gave birth in custody. Regression models examined differences in outcomes between women who received enhanced pregnancy support-group prenatal education and one-on-one doula visits-and a historical control group of women who received standard prenatal care. RESULTS: Adverse maternal and neonatal birth outcomes in this sample were rare. No differences in outcomes were found between incarcerated women who received enhanced pregnancy support and the historical control group. CONCLUSIONS: Despite evidence for the benefits of enhanced pregnancy support in the general population, this study did not find differences in outcomes between incarcerated women who did and did not receive support. Integrated data from prison and hospital records are innovative, but effect measurement is limited by sample size. Future research should include primary data collection on maternal, neonatal, and dyadic outcomes longitudinally and across prisons.

Body Mass Index and Risk for Intubation or Death in SARS-CoV-2 Infection : A Retrospective Cohort Study.

BACKGROUND: Obesity is a risk factor for pneumonia and acute respiratory distress syndrome. OBJECTIVE: To determine whether obesity is associated with intubation or death, inflammation, cardiac injury, or fibrinolysis in coronavirus disease 2019 (COVID-19). DESIGN: Retrospective cohort study. SETTING: A quaternary academic medical center and community hospital in New York City. PARTICIPANTS: 2466 adults hospitalized with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection over a 45-day period with at least 47 days of in-hospital observation. MEASUREMENTS: Body mass index (BMI), admission biomarkers of inflammation (C-reactive protein [CRP] level and erythrocyte sedimentation rate [ESR]), cardiac injury (troponin level), and fibrinolysis (D-dimer level). The primary end point was a composite of intubation or death in time-to-event analysis. RESULTS: Over a median hospital length of stay of 7 days (interquartile range, 3 to 14 days), 533 patients (22%) were intubated, 627 (25%) died, and 59 (2%) remained hospitalized. Compared with overweight patients, patients with obesity had higher risk for intubation or death, with the highest risk among those with class 3 obesity (hazard ratio, 1.6 [95% CI, 1.1 to 2.1]). This association was primarily observed among patients younger than 65 years and not in older patients (P for interaction by age = 0.042). Body mass index was not associated with admission levels of biomarkers of inflammation, cardiac injury, or fibrinolysis. LIMITATIONS: Body mass index was missing for 28% of patients. The primary analyses were conducted with multiple imputation for missing BMI. Upper bounding factor analysis suggested that the results are robust to possible selection bias. CONCLUSION: Obesity is associated with increased risk for intubation or death from COVID-19 in adults younger than 65 years, but not in adults aged 65 years or older. PRIMARY FUNDING SOURCE: National Institutes of Health.

Imaging functional motor connectivity in hemiparetic children with perinatal stroke.

Perinatal stroke causes lifelong disability, particularly hemiparetic cerebral palsy. Arterial ischemic strokes (AIS) are large, cortical, and subcortical injuries acquired near birth due to acute occlusion of the middle cerebral artery. Periventricular venous infarctions (PVI) are smaller, subcortical strokes acquired prior to 34 weeks gestation involving injury to the periventricular white matter. Both stroke types can damage motor pathways, thus, we investigated resulting alterations in functional motor networks and probed function. We measured blood oxygen level dependent (BOLD) fluctuations at rest in 38 participants [10 arterial patients (age = 14.7 ± 4.1 years), 10 venous patients (age = 13.5 ± 3.7 years), and 18 typically developing controls (TDCs) (age = 15.3 ± 5.1 years)] and explored strength and laterality of functional connectivity in the motor network. Inclusion criteria included MRI-confirmed, unilateral perinatal stroke, symptomatic hemiparetic cerebral palsy, and 6-19 years old at time of imaging. Seed-based functional connectivity analyses measured temporal correlations in BOLD response over the whole brain using primary motor cortices as seeds. Laterality indices based on mean z-scores in lesioned and nonlesioned hemispheres explored laterality. In AIS patients, significant differences in both strength and laterality of motor network connections were observed compared with TDCs. In PVI patients, motor networks largely resembled those of healthy controls, albeit slightly weaker and asymmetric, despite subcortical damage and hemiparesis. Functional connectivity strengths were not related to motor outcome scores for either stroke group. This study serves as a foundation to better understand how resting-state fMRI can assess motor functional connectivity and potentially be applied to explore mechanisms of interventional therapies after perinatal stroke.

Highly deformable hydrogels constructed by pH-triggered polyacid nanoparticle disassembly in aqueous dispersions.

Most hydrogels are prepared using small-molecule monomers but unfortunately this approach may not be feasible for certain biomaterial applications. Consequently, alternative gel construction strategies have been established, which include using covalent inter-linking of preformed gel particles, or microgels (MGs). For example, covalently interlinking pH-responsive MGs can produce hydrogels comprising doubly crosslinked microgels (DX MGs). We hypothesised that the deformability of such DX MGs was limited by the presence of intra-MG crosslinking. Thus, in this study we designed new nanoparticle (NP)-based gels based on pH-swellable NPs that are not internally crosslinked. Two polyacid NPs were synthesised containing methacrylic acid (MAA) and either ethyl acrylate (EA) or methyl methacrylate (MMA). The PMAA-EA and PMAA-MMA NPs were subsequently vinyl-functionalised using glycidyl methacrylate (GMA) prior to gel formation via free-radical crosslinking. The NPs mostly disassembled on raising the solution pH but some self-crosslinking was nevertheless evident. The gels constructed from the EA- and MMA-based NPs had greater breaking strains than a control DX MG. The effect of varying the solution pH during curing on the morphology and mechanical properties of gels prepared using PMAA-MMA-GMA NPs was studied and both remarkable deformability and excellent recovery were observed. The gels were strongly pH-responsive and had tensile breaking strains of up to 420% with a compressive strain-at-break of more than 93%. An optimised formulation produced the most deformable and stretchable gel yet constructed using NPs or MGs as the only building block.

Synthesis of polyacid nanogels: pH-responsive sub-100 nm particles for functionalisation and fluorescent hydrogel assembly.

Nanogels are crosslinked polymer particles with a swollen size between 1 and 100 nm. They are of major interest for advanced surface coatings, drug delivery, diagnostics and biomaterials. Synthesising polyacid nanogels that show triggered swelling using a scalable approach is a key objective of polymer colloid chemistry. Inspired by the ability of polar surfaces to enhance nanoparticle stabilisation, we report the first examples of pH-responsive polyacid nanogels containing high -COOH contents prepared by a simple, scalable, aqueous method. To demonstrate their functionalisation potential, glycidyl methacrylate was reacted with the -COOH chemical handles and the nanogels were converted to macro-crosslinkers. The concentrated (functionalised) nanogel dispersions retained their pH-responsiveness, were shear-thinning and formed physical gels at pH 7.4. The nanogels were covalently interlinked via free-radical coupling at 37 °C to form transparent, ductile, hydrogels. Mixing of the functionalised nanogels with polymer dots enabled covalent assembly of fluorescent hydrogels.

Forgotten Fundamentals: A Review of State Legislation on Nutrition for Incarcerated Pregnant and Postpartum People.

Adequate nutritional intake during pregnancy is critical to infant health and development. People with the capacity for pregnancy who are incarcerated have limited control over their diets and rely on prisons and jails to meet their nutritional needs. This study examined state and federal statutes pertaining to nutrition care for pregnant people while incarcerated. Following a systematic search and review, we identified four qualitative codes relating to access to vitamins, supplemental food, additional hydration, and prenatal nutrition education. Summaries of state and federal statutes pertaining to nutrition were developed and compared with current prenatal nutrition recommendations. Less than a third of states had nutrition-related mandates and no states had statutes that included all key nutrition recommendations. No federal statutes addressed nutrition during pregnancy. Additionally, our review found no provisions for enforcement of the limited nutritional statutes that do exist. To mitigate adverse health consequences for pregnant people and their fetuses, policymakers should enact or amend legislation to align nutrition standards in all prisons and jails with national policy recommendations and provide mechanisms to oversee compliance.

tRNA modification reprogramming contributes to artemisinin resistance in Plasmodium falciparum.

Plasmodium falciparum artemisinin (ART) resistance is driven by mutations in kelch-like protein 13 (PfK13). Quiescence, a key aspect of resistance, may also be regulated by a yet unidentified epigenetic pathway. Transfer RNA modification reprogramming and codon bias translation is a conserved epitranscriptomic translational control mechanism that allows cells to rapidly respond to stress. We report a role for this mechanism in ART-resistant parasites by combining tRNA modification, proteomic and codon usage analyses in ring-stage ART-sensitive and ART-resistant parasites in response to drug. Post-drug, ART-resistant parasites differentially hypomodify mcm5s2U on tRNA and possess a subset of proteins, including PfK13, that are regulated by Lys codon-biased translation. Conditional knockdown of the terminal s2U thiouridylase, PfMnmA, in an ART-sensitive parasite background led to increased ART survival, suggesting that hypomodification can alter the parasite ART response. This study describes an epitranscriptomic pathway via tRNA s2U reprogramming that ART-resistant parasites may employ to survive ART-induced stress.

Additional PfCRT mutations driven by selective pressure for improved fitness can result in the loss of piperaquine resistance and altered Plasmodium falciparum physiology.

IMPORTANCE: Our study leverages gene editing techniques in Plasmodium falciparum asexual blood stage parasites to profile novel mutations in mutant PfCRT, an important mediator of piperaquine resistance, which developed in Southeast Asian field isolates or in parasites cultured for long periods of time. We provide evidence that increased parasite fitness of these lines is the primary driver for the emergence of these PfCRT variants. These mutations differentially impact parasite susceptibility to piperaquine and chloroquine, highlighting the multifaceted effects of single point mutations in this transporter. Molecular features of drug resistance and parasite physiology were examined in depth using proteoliposome-based drug uptake studies and peptidomics, respectively. Energy minimization calculations, showing how these novel mutations might impact the PfCRT structure, suggested a small but significant effect on drug interactions. This study reveals the subtle interplay between antimalarial resistance, parasite fitness, PfCRT structure, and intracellular peptide availability in PfCRT-mediated parasite responses to changing drug selective pressures.

Metabolic disturbances identified by SPECT-CT in patients with a clinical diagnosis of sacroiliac joint incompetence.

PURPOSE: To establish the sensitivity and specificity of cross-sectional scintigraphy [single photon emission computed tomography (SPECT)] combined with computed X-ray tomography (CT) in the detection of sacroiliac joint (SIJ) mechanical dysfunction and evaluate reproducibility of reporting. METHODS: Patients with pelvic girdle pain either on the basis of peri-partum SIJ dysfunction or trauma were included. These patients were imaged with bone scintigraphy with hybrid imaging with SPECT/CT. RESULTS: The study group comprised 100 patients (72 females, 28 males). Trauma accounted for 52% and the remainder were patients with peri-partum pain. Average age was 43 years and average length of history was >2 years. The major finding was increased uptake in the upper SIJ and posterior soft-tissues/ligaments. Hybrid imaging had a sensitivity of 95% and specificity of 99%. Positive predictive value was 99% and negative predictive value 94%. Power of the test was 1.0. Reproducibility of the test was good with kappa values of 0.85. CONCLUSION: Hybrid imaging with SPECT/CT reproducibly demonstrates metabolic alterations around the SIJ in patients with SIJ dysfunction, which we have termed SIJ incompetence. The condition is more common than previously recognised and frequently occurs after trauma, which has not been reported previously.

A putative link between pertussis and new onset of gastroesophageal reflux an observational study.

Background: Pertussis is an infectious disease of the respiratory tract with a changing epidemiology. An increasing incidence has been found in the adult population with recurrent infections possibly related to changes in the current vaccine. Is there an association between pertussis infection, refractory cough and atypical gastro-oesophageal reflux (GORD)? Does this magnify and compound respiratory complications? Methods: Observational study which compares post-pertussis (n=103) with non-pertussis patients (n=105) with established GORD. Patients were assessed for laryngopharyngeal reflux and aspiration of refluxate by a novel scintigraphic study. Results: Both groups showed severe GORD in association with high rates of laryngopharyngeal reflux (LPR) and pulmonary aspiration and lung disease. High rates of hiatus hernia and clinical diagnosis of "atypical" asthma showed correlations with pulmonary aspiration. Conclusions: A high level of new onset LPR and lung aspiration has been shown in patients with chronic cough after recent pertussis infection by a novel scintigraphic technique with fused hybrid x-ray computed tomography (SPECT/CT).

Improving the Efficiency, Stability, and Adhesion of Perovskite Solar Cells Using Nanogel Additive Engineering.

Additive engineering has been applied widely to improve the efficiency and/or stability of perovskite solar cells (PSCs). Most additives used to date are difficult to locate within PSCs as they are small molecules or linear polymers. In this work, we introduce, for the first time, carboxylic acid-functionalized nanogels (NGs) as additives for PSCs. NGs are swellable sub-100 nm gel particles. The NGs consist of poly(2-(2-methoxyethoxy) ethyl methacrylate)-co-methacrylic acid-co-ethylenegylcol dimethacrylate (PMEO2MA-MAA-EGD) particles prepared by a scalable synthesis, which have a diameter of 40 nm. They are visualized in the perovskite films using SEM and are located at the grain boundaries. X-ray photoelectron and FTIR spectroscopy reveal that the NGs coordinate with Pb2+ via the -COOH groups. Including the NGs within the PSCs increased the grain size, decreased nonradiative recombination, and increased the power conversion efficiency (PCE) to 20.20%. The NGs also greatly increase perovskite stability to ambient storage, elevated temperature, and humidity. The best system maintained more than 80% of its original PCE after 180 days of storage under ambient conditions. Tensile cross-cut tape adhesion tests are used to assess perovskite film mechanical integrity. The NGs increased both the adhesion of the perovskite to the substrate and the mechanical stability. This study demonstrates that NGs are an attractive alternative to molecularly dispersed additives for providing performance benefits to PSCs. Our study indicates that the NGs act as a passivator, stabilizer, cross-linker, and adhesion promoter.