Synthesis of Structural ADP-Ribose Analogues as Inhibitors for SARS-CoV-2 Macrodomain 1.

Protein adenosine diphosphate (ADP)-ribosylation is crucial for a proper immune response. Accordingly, viruses have evolved ADP-ribosyl hydrolases to remove these modifications, a prominent example being the SARS-CoV-2 NSP3 macrodomain, "Mac1". Consequently, inhibitors are developed by testing large libraries of small molecule candidates, with considerable success. However, a relatively underexplored angle in design pertains to the synthesis of structural substrate mimics. Here, we present the synthesis and biophysical activity of novel adenosine diphosphate ribose (ADPr) analogues as SARS-CoV-2 NSP3 Mac1 inhibitors.

Perceived acceptability and appropriateness of a web-based program targeting risk for anxiety in young children and their parents.

OBJECTIVE: This mixed-methods study examined perceived acceptability and appropriateness of a novel digital mental health program targeting anxiety risk (i.e., perfectionism or error sensitivity) in 5-to-7-year-old children and their parents. METHODS: Parent-child dyads participated in a modular, web-based cognitive-behavioral program targeting negative overreactions to making mistakes. The program, "Making Mistakes", consisted of a 6-month series of short video clips, journaling activities, and weekly reminders, and modules were delivered to caregivers and children separately. 86 dyads completed self-report measures, 18 of whom participated in semi-structured interviews, following completion of the primary program module. A standard thematic analysis was used to elucidate themes from the parent and child interview content. RESULTS: Our quantitative and qualitative results were generally aligned. Children and parents viewed the novel digital mental health program as acceptable and appropriate, favoring the cognitive behavioral strategies such as modeling positive reactions to mistakes, responding positively to child mistakes, and emphasizing effort over outcome. Participants also provided helpful feedback related to program content, delivery, and engagement, as well as suggestions to enhance the program. CONCLUSIONS: Findings have implications for design and content features of parent-based and dyad-based programs, as well as digital mental health programs focused on reducing anxiety risk.

Lung Cancer Screening Before and After a Multifaceted Electronic Health Record Intervention: A Nonrandomized Controlled Trial.

Importance: Lung cancer is the deadliest cancer in the US. Early-stage lung cancer detection with lung cancer screening (LCS) through low-dose computed tomography (LDCT) improves outcomes. Objective: To assess the association of a multifaceted clinical decision support intervention with rates of identification and completion of recommended LCS-related services. Design, Setting, and Participants: This nonrandomized controlled trial used an interrupted time series design, including 3 study periods from August 24, 2019, to April 27, 2022: baseline (12 months), period 1 (11 months), and period 2 (9 months). Outcome changes were reported as shifts in the outcome level at the beginning of each period and changes in monthly trend (ie, slope). The study was conducted at primary care and pulmonary clinics at a health care system headquartered in Salt Lake City, Utah, among patients aged 55 to 80 years who had smoked 30 pack-years or more and were current smokers or had quit smoking in the past 15 years. Data were analyzed from September 2023 through February 2024. Interventions: Interventions in period 1 included clinician-facing preventive care reminders, an electronic health record-integrated shared decision-making tool, and narrative LCS guidance provided in the LDCT ordering screen. Interventions in period 2 included the same clinician-facing interventions and patient-facing reminders for LCS discussion and LCS. Main Outcome and Measure: The primary outcome was LCS care gap closure, defined as the identification and completion of recommended care services. LCS care gap closure could be achieved through LDCT completion, other chest CT completion, or LCS shared decision-making. Results: The study included 1865 patients (median [IQR] age, 64 [60-70] years; 759 female [40.7%]). The clinician-facing intervention (period 1) was not associated with changes in level but was associated with an increase in slope of 2.6 percentage points (95% CI, 2.4-2.7 percentage points) per month in care gap closure through any means and 1.6 percentage points (95% CI, 1.4-1.8 percentage points) per month in closure through LDCT. In period 2, introduction of patient-facing reminders was associated with an immediate increase in care gap closure (2.3 percentage points; 95% CI, 1.0-3.6 percentage points) and closure through LDCT (2.4 percentage points; 95% CI, 0.9-3.9 percentage points) but was not associated with an increase in slope. The overall care gap closure rate was 175 of 1104 patients (15.9%) at the end of the baseline period vs 588 of 1255 patients (46.9%) at the end of period 2. Conclusions and Relevance: In this study, a multifaceted intervention was associated with an improvement in LCS care gap closure. Trial Registration: ClinicalTrials.gov Identifier: NCT04498052.

A novel expression domain of extradenticle underlies the evolutionary developmental origin of the chelicerate patella.

Neofunctionalization of duplicated gene copies is thought to be an important process underlying the origin of evolutionary novelty and provides an elegant mechanism for the origin of new phenotypic traits. One putative case where a new gene copy has been linked to a novel morphological trait is the origin of the arachnid patella, a taxonomically restricted leg segment. In spiders, the origin of this segment has been linked to the origin of the paralog dachshund-2 , suggesting that a new gene facilitated the expression of a new trait. However, various arachnid groups that possess patellae do not have a copy of dachshund-2 , disfavoring the direct link between gene origin and trait origin. We investigated the developmental genetic basis for patellar patterning in the harvestman Phalangium opilio , which lacks dachshund-2 . Here, we show that the harvestman patella is established by a novel expression domain of the transcription factor extradenticle . Leveraging this definition of patellar identity, we surveyed targeted groups across chelicerate phylogeny to assess when this trait evolved. We show that a patellar homolog is present in Pycnogonida (sea spiders) and various arachnid orders, suggesting a single origin of the patella in the ancestor of Chelicerata. A potential loss of the patella is observed in Ixodida. Our results suggest that the modification of an ancient gene, rather than the neofunctionalization of a new gene copy, underlies the origin of the patella. Broadly, this work underscores the value of comparative data and broad taxonomic sampling when testing hypotheses in evolutionary developmental biology.

Renewable hemicellulose-based materials for value-added applications.

The importance of renewable resources and environmentally friendly materials has grown globally in recent time. Hemicellulose is renewable lignocellulosic materials that have been the subject of substantial valorisation research. Due to its distinctive benefits, including its wide availability, low cost, renewability, biodegradability, simplicity of chemical modification, etc., it has attracted increasing interest in a number of value-added fields. In this review, a systematic summarizes of the structure, extraction method, and characterization technique for hemicellulose-based materials was carried out. Also, their most current developments in a variety of value-added adsorbents, biomedical, energy-related, 3D-printed materials, sensors, food packaging applications were discussed. Additionally, the most recent challenges and prospects of hemicellulose-based materials are emphasized and examined in-depth. It is anticipated that in the near future, persistent scientific efforts will enable the renewable hemicellulose-based products to achieve practical applications.

Biochemical characterization of purified phytase produced from Aspergillus awamori AFE1 associated with the gastrointestinal tract of longhorn beetle (Cerambycidae latreille).

The need for industrially and biotechnologically significant enzymes, such as phytase, is expanding daily as a result of the increased use of these enzymes in a variety of operations, including the manufacture of food, animal feed, and poultry feed. This study sought to characterize purified phytase from A. awamori AFE1 isolated from longhorn beetle for its prospect in industrial applications. Ammonium sulfate precipitation, ion-exchange chromatography, and gel-filtration chromatography were used to purify the crude enzyme obtained from submerged fermentation using phytase-producing media, and its physicochemical characteristics were examined. The homogenous 46.8-kDa phytase showed an 8.1-fold purification and 40.7% recovery. At 70 C and pH 7, the optimum phytase activity was noted. At acidic pH 4-6 and alkaline pH 8-10, it likewise demonstrated relative activity of 88-95% and 67-88%, respectively. It showed 67-70% residual activity between 30 and 70 C after 40 min, and 68-94% residual activity between pH 2 and 12 after 2 h. The presence of Hg+, Mg2+, and Al3+ significantly decreased the enzymatic activity, whereas Ca2+ and Cu2+ enhanced it. Ascorbic acid increased the activity of the purified enzyme, whereas ethylenediaminetetraacetic acid (EDTA) and mercaptoethanol inhibited it. The calculated values for Km and Vmax were 55.4 mM and1.99 µmol/min/mL respectively. A. awamori phytase, which was isolated from a new source, showed unique and remarkable qualities that may find use in industrial operations such as feed pelleting and food processing.

Towards zebrafish models to unravel translational insights of obsessive-compulsive disorder: A neurobehavioral perspective.

Obsessive-compulsive disorder (OCD) is a chronic and debilitating illness that has been considered a polygenic and multifactorial disorder, challenging effective therapeutic interventions. Although invaluable advances have been obtained from human and rodent studies, several molecular and mechanistic aspects of OCD etiology are still obscure. Thus, the use of non-traditional animal models may foster innovative approaches in this field, aiming to elucidate the underlying mechanisms of disease from an evolutionary perspective. The zebrafish (Danio rerio) has been increasingly considered a powerful organism in translational neuroscience research, especially due to the intrinsic features of the species. Here, we outline target mechanisms of OCD for translational research, and discuss how zebrafish-based models can contribute to explore neurobehavioral aspects resembling those found in OCD. We also identify possible advantages and limitations of potential zebrafish-based models, as well as highlight future directions in both etiological and therapeutic research. Lastly, we reinforce the use of zebrafish as a promising tool to unravel the biological basis of OCD, as well as novel pharmacological therapies in the field.

Utility of zebrafish-based models in understanding molecular mechanisms of neurotoxicity mediated by the gut-brain axis.

The gut microbes perform several beneficial functions which impact the periphery and central nervous systems of the host. Gut microbiota dysbiosis is acknowledged as a major contributor to the development of several neuropsychiatric and neurological disorders including bipolar disorder, depression, anxiety, Parkinson's disease, Alzheimer's disease, attention deficit hyperactivity disorder, and autism spectrum disorder. Thus, elucidation of how the gut microbiota-brain axis plays a role in health and disease conditions is a potential novel approach to prevent and treat brain disorders. The zebrafish (Danio rerio) is an invaluable vertebrate model that possesses conserved brain and intestinal features with those of humans, thus making zebrafish a valued model to investigate the interplay between the gut microbiota and host health. This chapter describes current findings on the utility of zebrafish in understanding molecular mechanisms of neurotoxicity mediated via the gut microbiota-brain axis. Specifically, it highlights the utility of zebrafish as a model organism for understanding how anthropogenic chemicals, pharmaceuticals and bacteria exposure affect animals and human health via the gut-brain axis.

Severity and complications in infants with respiratory syncytial virus infection after the SARS-CoV-2 pandemic.

BACKGROUND: After the SARS-CoV-2 pandemic, there has been an increase in hospitalization for lower respiratory infection secondary to respiratory syncytial virus (RSV), with greater complications. Associated extrapulmonary alterations, biventricular dysfunction, acute kidney injury, among others, have been found. The objective of this study was to analize the evolution and complications in hospitalized children with lower respiratory infection secondary to RSV after COVID-19 pandemic. METHODS: All pediatric patients under 2 years of age admitted to the emergency department with RSV infection were included. Clinical characteristics, need for supplemental oxygen, use of amines, renal angina index, and requirement for renal replacement therapy were analyzed. Lung ultrasound was performed upon admission. Statistical analysis was carried out for the quantitative variables by means of mean and standard deviation, and qualitative variables by frequency and percentage. Differences in the distribution were evaluated with Fisher's exact distribution. RESULTS: 45 patients with RSV infection were identified, 26.7% required invasive mechanical ventilation and 11.1% requiered peritoneal dialysis. Fatality was observed in four cases, three of these younger than 12 months with a LUS score > 7; contrasts with 90.2% of survivors with a score < 7 (p = 0.0004). CONCLUSIONS: An increase in the incidence of bronchiolitis after pandemic was observed, with more than half having moderate to severe symptoms and requiring supplemental oxygen support in all patients upon admission. Acute kidney injury is the most common extrapulmonary manifestation.

INTRODUCCIÓN: Posterior a la pandemia por SARS-CoV-2 se ha observado un incremento en la hospitalización por virus respiratorio sincitial (VRS), con mayores complicaciones. Se han encontrado alteraciones extrapulmonares asociadas, disfunción biventricular y lesión renal aguda, entre otras. El objetivo de este estudio fue analizar la evolución y las complicaciones en niños hospitalizados con enfermedad respiratoria de vías bajas secundaria a infección por VRS tras la pandemia de COVID-19. MÉTODOS: Se incluyeron todos los menores de 2 años que ingresaron al servicio de urgencias con infección por VRS. Se analizaron las características clínicas, la necesidad de oxígeno suplementario, el uso de aminas, el índice de angina renal y el requerimiento de terapia de sustitución renal. Se realizó ecografía pulmonar al ingreso. En el análisis estadístico, para las variables cuantitativas se determinaron la media y la desviación estándar, y para las variables cualitativas la frecuencia y el porcentaje. Se evaluaron las diferencias de la distribución con la prueba exacta de Fisher. RESULTADOS: Hubo 45 pacientes con infección por VRS. El 26.7% requirieron ventilación mecánica invasiva y el 11.1% diálisis peritoneal. La letalidad fue de cuatro casos, tres de ellos menores de 12 meses con puntuación de LUS > 7; esto contrasta con el 90.2% de los sobrevivientes con puntaje < 7 (p = 0.0004). CONCLUSIONES: Se observó un aumento en la incidencia de bronquiolitis tras la pandemia, en más de la mitad de los casos con cuadros de moderados a graves, y todos requirieron oxígeno suplementario al ingreso. La lesión renal aguda fue la manifestación extrapulmonar más frecuente.

Insomnia in Forensic Detainees: Is Salience Network the Common Pathway for Sleep, Neuropsychiatric, and Neurodegenerative Disorders?

Forensic hospitals throughout the country house individuals with severe mental illness and history of criminal violations. Insomnia affects 67.4% of hospitalized patients with chronic neuropsychiatric disorders, indicating that these conditions may hijack human somnogenic pathways. Conversely, somnolence is a common adverse effect of many antipsychotic drugs, further highlighting a common etiopathogenesis. Since the brain salience network is likely the common denominator for insomnia, neuropsychiatric and neurodegenerative disorders, here, we focus on the pathology of this neuronal assembly and its likely driver, the dysfunctional neuronal and mitochondrial membrane. We also discuss potential treatment strategies ranging from membrane lipid replacement to mitochondrial transplantation. The aims of this review are threefold: 1. Examining the causes of insomnia in forensic detainees with severe mental illness, as well as its role in predisposing them to neurodegenerative disorders. 2. Educating State hospital and prison clinicians on frontotemporal dementia behavioral variant, a condition increasingly diagnosed in older first offenders which is often missed due to the absence of memory impairment. 3. Introducing clinicians to natural compounds that are potentially beneficial for insomnia and severe mental illness.

Impact of chronic thrombocytopenia on healthcare resource utilization, in-hospital outcomes, and costs following percutaneous coronary intervention of chronic total occlusion: a nationwide propensity weighted analysis.

BACKGROUND: Data on the impact of chronic thrombocytopenia (CT) on outcomes following chronic total occlusion (CTO) percutaneous coronary interventions (PCI) is limited. Most studies are case reports and focused on postprocedural thrombocytopenia. The purpose of this present study is to assess the impact of CT (> one year) on health resource utilization (HRU), in-hospital outcomes, and cost following CTO PCI. METHODS: We used discharge data from the 2016-2018 National Inpatient Sample and propensity score-weighted approach to examine the association between CT and HRU among patients undergoing CTO PCI. HRU was measured as a binary indicator defined as a length of stay greater than seven days and/or discharge to a non-home setting. The cost was measured as total charges standardized to 2018 dollars. Both outcomes were assessed using generalized linear models adjusted for survey year, and baseline characteristics. RESULTS: Relative to its absence, the presence of CT following CTO PCI was associated with a 4.8% increased probability of high HRU (Population Average Treatment Effect (PATE) estimate = 0.048; 95% Confidence Interval (CI) = 0.041-0.055; P<0.001) and approximately $18,000 more in total hospital charges (PATE estimate = +$18,297.98; 95% CI = $15,101.33-$21,494.63, P<0.001). CONCLUSION: Among chronic total occlusion patients undergoing percutaneous coronary intervention, those with chronic thrombocytopenia had higher resource use, including total hospital charges, and worse in-hospital outcomes when compared with those without chronic thrombocytopenia.

Birth Prevalence of Sickle Cell Disease and County-Level Social Vulnerability - Sickle Cell Data Collection Program, 11 States, 2016-2020.

Sickle cell disease (SCD) remains a public health priority in the United States because of its association with complex health needs, reduced life expectancy, lifelong disabilities, and high cost of care. A cross-sectional analysis was conducted to calculate the crude and race-specific birth prevalence for SCD using state newborn screening program records during 2016-2020 from 11 Sickle Cell Data Collection program states. The percentage distribution of birth mother residence within Social Vulnerability Index quartiles was derived. Among 3,305 newborns with confirmed SCD (including 57% with homozygous hemoglobin S or sickle ß-null thalassemia across 11 states, 90% of whom were Black or African American [Black], and 4% of whom were Hispanic or Latino), the crude SCD birth prevalence was 4.83 per 10,000 (one in every 2,070) live births and 28.54 per 10,000 (one in every 350) non-Hispanic Black newborns. Approximately two thirds (67%) of mothers of newborns with SCD lived in counties with high or very high levels of social vulnerability; most mothers lived in counties with high or very high levels of vulnerability for racial and ethnic minority status (89%) and housing type and transportation (64%) themes. These findings can guide public health, health care systems, and community program planning and implementation that address social determinants of health for infants with SCD. Implementation of tailored interventions, including increasing access to transportation, improving housing, and advancing equity in high vulnerability areas, could facilitate care and improve health outcomes for children with SCD.

Social domains of poor mental health: A qualitative pilot study of community stakeholders' understanding and demarcation of mental illness and its interpretations in rural Nigeria.

Background and Aims: Although previous studies on mental health/illness in Nigeria have explored knowledge and attitude of community members using quantitative approaches, few studies have engaged stakeholders within rural communities on the issue of mental illness using qualitative approaches. Community stakeholders play a critical role in influencing health behaviors. The objective of this pilot study was to explore community stakeholders' understanding and demarcation of mental illness, and its interpretations in a rural Nigerian town. This is with the aim of shaping stakeholders understanding of people when they experience mental distress within the community. Methods: The study was conducted in Ijebu-Igbo town of Ogun State in south-west Nigeria. In-depth interviews were conducted among two religious' leaders: a Pastor and an Imam, a traditional healer, a medical doctor, and a registered nurse, and a focus group discussion was held in a church with members of its advisory committee. Results: The findings showed that community stakeholders gave multiple interpretations of mental illness and many attribute mental illness to spiritual attack, ancestral curse, anger of the gods, and personal affliction (Ogun-Afowofa). This has been categorized as familial and individual attributes in this study which is part of the main themes derived. The study findings also show that the understanding of community members regarding the root causes of mental illness is somewhat vague based on their poor knowledge of mental illness. This is because of the various interpretations they gave to explain mental health is based on their cultural orientation, socialization, and belief system, and not based on any medical knowledge. Conclusion: This pilot study was conducted to justify the main study. There is therefore a need for health education interventions to enlighten and educate community stakeholders with requisite knowledge for better understanding and interpretation of mental illness. Also, through mental health education interventions, community members will gain clarity on what mental health is and what it is not.

The influence of acute dopamine transporter inhibition on manic-, depressive-like phenotypes, and brain oxidative status in adult zebrafish.

Functional changes in dopamine transporter (DAT) are related to various psychiatric conditions, including bipolar disorder (BD) symptoms. In experimental research, the inhibition of DAT induces behavioral alterations that recapitulate symptoms found in BD patients, including mania and depressive mood. Thus, developing novel animal models that mimic BD-related conditions by pharmacologically modulating the dopaminergic signaling is relevant. The zebrafish (Danio rerio) has been considered a suitable vertebrate system for modeling BD-like responses, due to the well-characterized behavioral responses and evolutionarily conservation of the dopaminergic system of this species. Here, we investigate whether GBR 12909, a selective inhibitor of DAT, causes neurobehavioral alterations in zebrafish similar to those observed in BD patients. Behaviors were recorded after a single intraperitoneal (i.p.) administration of GBR 12909 at different doses (3.75, 7.5, 15 and 30 mg/kg). To observe temporal effects on behavior, swim path parameters were measured immediately after the administration period during 30 min. Locomotion, anxiety-like behavior, social preference, aggression, despair-like behavior, and oxidative stress-related biomarkers in the brain were measured 30 min post administration. GBR 12909 induced prominent effects on locomotor activity and vertical exploration during the 30-min period. Hyperactivity was observed in GBR 30 group after 25 min, while all doses markedly reduced vertical drifts. GBR 12909 elicited hyperlocomotion, anxiety-like behavior, decreased social preference, aggression, and induced depressive-like behavior in a behavioral despair task. Depending on the dose, GBR 12909 also decreased SOD activity and TBARS levels, as well as increased GR activity and NPSH content. Collectively, our novel findings show that a single GBR 12909 administration evokes neurobehavioral changes that recapitulate manic- and depressive-like states observed in rodents, fostering the use of zebrafish models to explore BD-like responses in translational neuroscience research.

Reliability of the Metabolic Response During Steady-State Exercise at FATmax in Young Men with Obesity.

Purpose: In this study we evaluated the reliability of blood lactate levels (BLa), energy expenditure and substrate utilization during prolonged exercise at the intensity that elicits maximal fat oxidation (FATmax). Furthermore, we investigated the accuracy of a single graded exercise test (GXT) for predicting energy metabolism at FATmax. Methods: Seventeen young men with obesity (26 ± 6 years; 36.4 ± 7.2 %body fat) performed a GXT on a treadmill in a fasted state (10-12 h) for the assessment of FATmax and cardiorespiratory fitness. Afterward, each subject performed two additional prolonged FATmax trials (102 ± 11 beats·min-1; 60-min) separated by 7 days. Indirect calorimetry was used for the assessment of energy expenditure and substrate utilization kinetics whereas capillary blood samples were taken for the measurement of BLa. Results: The BLa (limits of agreement (LoA): -1.2 to 0.8 mmol∙L-1; p = 1.0), fat utilization (LoA: -8.0 to 13.4 g∙h-1; p = 0.06), and carbohydrate utilization (LoA: -27.6 to 22.4 g∙h-1; p = 0.41) showed a good agreement whereas a modest systematic bias was found for energy expenditure (LoA: -16811 to 33355 kJ∙h-1; p < 0.05). All the aforementioned parameters showed a moderate to good reliability (Intraclass correlation coefficient: 0.67-0.92). The GXT overestimated fat (~46%) and carbohydrate (~26%) utilization as well as energy expenditure (36%) during steady-state exercise at FATmax. Conversely the GXT underestimated BLa (~28%). Conclusion: a single GXT cannot be used for an accurate prediction of energy metabolism during prolonged exercise in men with obesity. Thus, an additional steady-state FATmax trial (40-60 min) should be performed for a tailored and precise exercise prescription.

The polymorphism T1470A of the SLC16A1 gene is associated with the lactate and ventilatory thresholds but not with fat oxidation capacity in young men.

PURPOSE: To examine the association of the single nucleotide polymorphism A1470T in the SLC16A1 gene with blood lactate accumulation during a graded exercise test and its associated metaboreflex. METHODS: Forty-six Latin-American men (Age: 27 ± 6 years; Body fat: 17.5 ± 4.7%) performed a graded exercise test on a treadmill for the assessment of maximal oxygen uptake (VO2max), lactate threshold (LT), ventilatory threshold (VT) and the exercise intensity corresponding to maximal fat oxidation rate (FATmax), via capillary blood samples and indirect calorimetry. Genomic DNA was extracted from a peripheral blood sample. Genotyping assay was carried out by real-time polymerase chain reaction to identify the A1470T polymorphism (rs1049434). RESULTS: Genotypes distribution were in Hardy-Weinberg equilibrium (X2 = 5.6, p > 0.05), observing allele frequencies of 0.47 and 0.53 for the A and T alleles, respectively. No difference in VO2max, body composition nor FATmax were observed across genotypes, whereas carriers of the TT genotype showed a higher LT (24.5 ± 2.2 vs. 15.6 ± 1.7 mL kg-1 min-1, p < 0.01) and VT in comparison to carriers of the AA + AT genotypes (32.5 ± 3.3 vs. 21.7 ± 1.5 mL kg-1 min-1, p < 0.01). Both, VO2max and the A1470T polymorphism were positively associated to the LT (R2 = 0.50, p < 0.01) and VT (R2 = 0.55, p < 0.01). Only VO2max was associated to FATmax (R2 = 0.39, p < 0.01). CONCLUSION: Independently of cardiorespiratory fitness, the A1470T polymorphism is associated to blood lactate accumulation and its associated ventilatory response during submaximal intensity exercise. However, the A1470 polymorphism does not influence fat oxidation capacity during exercise in young men.

Enantio- and Diastereodivergent Cyclopropanation of Allenes by Directed Evolution of an Iridium-Containing Cytochrome.

Alkylidene cyclopropanes (ACPs) are valuable synthetic intermediates because of their constrained structure and opportunities for further diversification. Although routes to ACPs are known, preparations of ACPs with control of both the configuration of the cyclopropyl (R vs S) group and the geometry of the alkene (E vs Z) are unknown. We describe enzymatic cyclopropanation of allenes with ethyl diazoacetate (EDA) catalyzed by an iridium-containing cytochrome (Ir(Me)-CYP119) that controls both stereochemical elements. Two mutants of Ir(Me)-CYP119 identified by 6-codon (6c, VILAFG) saturation mutagenesis catalyze the formation of (E)-ACPs with -93% to >99% ee and >99:1 E/Z ratio with just three rounds of 96 mutants. By four additional rounds of mutagenesis, an enzyme variant was identified that forms (Z)-ACPs with up to 94% ee and a 28:72 E/Z ratio. Computational studies show that the orientation of the carbene unit dictated by the mutated positions accounts for the stereoselectivity.

Diphenyl Diselenide Through Reduction of Inflammation, Oxidative Injury and Caspase-3 Activation Abates Doxorubicin-Induced Neurotoxicity in Rats.

Neurotoxicity associated with chemotherapy is a debilitating side effect of cancer management in humans which reportedly involves inflammatory and oxidative stress responses. Diphenyl diselenide (DPDS) is an organoselenium compound which exhibits its anti-tumoral, anti-oxidant, anti-inflammatory and anti-mutagenic effects. Nevertheless, its possible effect on chemotherapy-induced neurotoxicity is not known. Using rat model, we probed the behavioral and biochemical effects accompanying administration of antineoplastic agent doxorubicin (7.5 mg/kg) and DPDS (5 and 10 mg/kg). Anxiogenic-like behavior, motor and locomotor insufficiencies associated with doxorubicin were considerably abated by both DPDS doses with concomitant enhancement in exploratory behavior as demonstrated by reduced heat maps intensity and enhanced track plot densities. Moreover, with exception of cerebral glutathione (GSH) level, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, biochemical data demonstrated reversal of doxorubicin-mediated decline in cerebral and cerebellar antioxidant status indices and the increase in acetylcholinesterase (AChE) activity by both doses of DPDS. Also, cerebellar and cerebral lipid peroxidation, hydrogen peroxide as well as reactive oxygen and nitrogen species levels were considerably diminished in rats administered doxorubicin and DPDS. In addition, DPDS administration abated myeloperoxidase activity, tumour necrosis factor alpha and nitric oxide levels along with caspase-3 activity in doxorubicin-administered rats. Chemoprotection of doxorubicin-associated neurotoxicity by DPDS was further validated by histomorphometry and histochemical staining. Taken together, DPDS through offsetting of oxido-inflammatory stress and caspase-3 activation elicited neuroprotection in doxorubicin-treated rats.

Schistosoma mansoni vaccine candidates identified by unbiased phage display screening in self-cured rhesus macaques.

Schistosomiasis, a challenging neglected tropical disease, affects millions of people worldwide. Developing a prophylactic vaccine against Schistosoma mansoni has been hindered by the parasite's biological complexity. In this study, we utilized the innovative phage-display immunoprecipitation followed by a sequencing approach (PhIP-Seq) to screen the immune response of 10 infected rhesus macaques during self-cure and challenge-resistant phases, identifying vaccine candidates. Our high-throughput S. mansoni synthetic DNA phage-display library encoded 99.6% of 119,747 58-mer peptides, providing comprehensive coverage of the parasite's proteome. Library screening with rhesus macaques' antibodies, from the early phase of establishment of parasite infection, identified significantly enriched epitopes of parasite extracellular proteins known to be expressed in the digestive tract, shifting towards intracellular proteins during the late phase of parasite clearance. Immunization of mice with a selected pool of PhIP-Seq-enriched phage-displayed peptides from MEG proteins, cathepsins B, and asparaginyl endopeptidase significantly reduced worm burden in a vaccination assay. These findings enhance our understanding of parasite-host immune responses and provide promising prospects for developing an effective schistosomiasis vaccine.

Adaptive immune cells are necessary for SARS-CoV-2-induced pathology.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the ongoing global pandemic associated with morbidity and mortality in humans. Although disease severity correlates with immune dysregulation, the cellular mechanisms of inflammation and pathogenesis of COVID-19 remain relatively poorly understood. Here, we used mouse-adapted SARS-CoV-2 strain MA10 to investigate the role of adaptive immune cells in disease. We found that while infected wild-type mice lost ~10% weight by 3 to 4 days postinfection, rag-/- mice lacking B and T lymphocytes did not lose weight. Infected lungs at peak weight loss revealed lower pathology scores, fewer neutrophils, and lower interleukin-6 and tumor necrosis factor-α in rag-/- mice. Mice lacking αß T cells also had less severe weight loss, but adoptive transfer of T and B cells into rag-/- mice did not significantly change the response. Collectively, these findings suggest that while adaptive immune cells are important for clearing SARS-CoV-2 infection, this comes at the expense of increased inflammation and pathology.