Hybrid speciation driven by multilocus introgression of ecological traits.

Hybridization allows adaptations to be shared among lineages and may trigger the evolution of new species1,2. However, convincing examples of homoploid hybrid speciation remain rare because it is challenging to demonstrate that hybridization was crucial in generating reproductive isolation3. Here we combine population genomic analysis with quantitative trait locus mapping of species-specific traits to examine a case of hybrid speciation in Heliconius butterflies. We show that Heliconius elevatus is a hybrid species that is sympatric with both parents and has persisted as an independently evolving lineage for at least 180,000 years. This is despite pervasive and ongoing gene flow with one parent, Heliconius pardalinus, which homogenizes 99% of their genomes. The remaining 1% introgressed from the other parent, Heliconius melpomene, and is scattered widely across the H. elevatus genome in islands of divergence from H. pardalinus. These islands contain multiple traits that are under disruptive selection, including colour pattern, wing shape, host plant preference, sex pheromones and mate choice. Collectively, these traits place H. elevatus on its own adaptive peak and permit coexistence with both parents. Our results show that speciation was driven by introgression of ecological traits, and that speciation with gene flow is possible with a multilocus genetic architecture.

Drug exposure during pregnancy: Current understanding and approaches to measure maternal-fetal drug exposure.

Prescription drug use is prevalent during pregnancy, yet there is limited knowledge about maternal-fetal safety and efficacy of this drug use because pregnant individuals have historically been excluded from clinical trials. Underrepresentation has resulted in a lack of data available to estimate or predict fetal drug exposure. Approaches to study fetal drug pharmacology are limited and must be evaluated for feasibility and accuracy. Anatomic and physiological changes throughout pregnancy fluctuate based on gestational age and can affect drug pharmacokinetics (PK) for both mother and fetus. Drug concentrations have been studied throughout different stages of gestation and at or following delivery in tissue and fluid biospecimens. Sampling amniotic fluid, umbilical cord blood, placental tissue, meconium, umbilical cord tissue, and neonatal hair present surrogate options to quantify and characterize fetal drug exposure. These sampling methods can be applied to all therapeutics including small molecule drugs, large molecule drugs, conjugated nanoparticles, and chemical exposures. Alternative approaches to determine PK have been explored, including physiologically based PK modeling, in vitro methods, and traditional animal models. These alternative approaches along with convenience sampling of tissue or fluid biospecimens can address challenges in studying maternal-fetal pharmacology. In this narrative review, we 1) present an overview of the current understanding of maternal-fetal drug exposure; 2) discuss biospecimen-guided sampling design and methods for measuring fetal drug concentrations throughout gestation; and 3) propose methods for advancing pharmacology research in the maternal-fetal population.

Improving Dose-Optimization Processes Used in Oncology Drug Development to Minimize Toxicity and Maximize Benefit to Patients.

This review highlights strategies to integrate dose optimization into premarketing drug development and discusses the underlying statistical principles. Poor dose optimization can have negative consequences for patients, most commonly because of toxicity, including poor quality of life, reduced effectiveness because of inability of patients to stay on current therapy or receive subsequent therapy because of toxicities, and difficulty in developing combination regimens. We reviewed US Food and Drug Administration initial approvals (2019-2021) of small molecules and antibody-drug conjugates for oncologic indications to determine the proportion with a recommended dosage at the maximum tolerated dose or the maximal administered dose, to characterize the use of randomized evaluations of multiple dosages in dose selection, to describe the frequency of dose modifications at the recommended dosage, and to identify case examples that highlight key principles for premarket dose optimization during drug development. Herein, we highlight major principles for dose optimization and review examples of recent US Food and Drug Administration approvals that illustrate how investigation of dose- and exposure-response relationships and use of randomized dose trials can support dose optimization. Although there has been some progress, dose optimization through randomized dose evaluation in oncology trials is not routinely conducted. Dose optimization is essential to ensure that patients receive therapies which maximize efficacy while minimizing toxicity.

Examination of Complementary Medicine for Treating Urinary Tract Infections Among Pregnant Women and Children.

Urinary tract infections (UTIs) are a significant clinical problem that pregnant women and children commonly experience. Escherichia coli is the primary causative organism, along with several other gram-negative and gram-positive bacteria. Antimicrobial drugs are commonly prescribed to treat UTIs in these patients. Conventional treatment can range from using broad-spectrum antimicrobial drugs for empirical or prophylactic therapy or patient-tailored therapy based on urinary cultures and sensitivity to prospective antibiotics. The ongoing emergence of multi-drug resistant pathogens has raised concerns related to commonly prescribed antimicrobial drugs such as those used routinely to treat UTIs. Consequently, several natural medicines have been explored as potential complementary therapies to improve health outcomes in patients with UTIs. This review discusses the effectiveness of commonly used natural products such as cranberry juice/extracts, ascorbic acid, hyaluronic acid, probiotics, and multi-component formulations intended to treat and prevent UTIs. The combination of natural products with prescribed antimicrobial treatments and use of formulations that contained high amounts of cranberry extracts appear to be most effective in preventing recurrent UTIs (RUTIs). The incorporation of natural products like cranberry, hyaluronic acid, ascorbic acid, probiotics, Canephron® N, and Cystenium II to conventional treatments of acute UTIs or as a prophylactic regimen for treatment RUTIs can benefit both pregnant women and children. Limited information is available on the safety of natural products in these patients' populations. However, based on limited historical information, these remedies appear to be safe and well-tolerated by patients.

Antibody-drug Conjugate PCMC1D3-Duocarmycin SA as a Novel Therapeutic Entity for Targeted Treatment of Cancers Aberrantly Expressing MET Receptor Tyrosine Kinase.

BACKGROUND: Aberrant expression of the MET receptor tyrosine kinase is an oncogenic determinant and a drug target for cancer therapy. Currently, antibody-based biotherapeutics targeting MET are under clinical trials. OBJECTIVE: Here, we report the preclinical and therapeutic evaluation of a novel anti-MET antibody- drug conjugate PCMC1D3-duocarmycin SA (PCMC1D3-DCM) for targeted cancer therapy. METHODS: The monoclonal antibody PCMC1D3 (IgG1a/κ), generated by a hybridoma technique and specific to one of the MET extracellular domains, was selected based on its high specificity to human MET with a binding affinity of 1.60 nM. PCMC1D3 was conjugated to DCM via a cleavable valine-citrulline dipeptide linker to form an antibody-drug conjugate with a drug-to-antibody ratio of 3.6:1. PCMC1D3-DCM in vitro rapidly induced MET internalization with an internalization efficacy ranging from 6.5 to 17.2h dependent on individual cell lines. RESULTS: Studies using different types of cancer cell lines showed that PCMC1D3-DCM disrupted the cell cycle, reduced cell viability, and caused massive cell death within 96h after treatment initiation. The calculated IC50 values for cell viability reduction were 1.5 to 15.3 nM. Results from mouse xenograft tumor models demonstrated that PCMC1D3-DCM in a single dose injection at 10 mg/kg body weight effectively delayed xenograft tumor growth up to two weeks without signs of tumor regrowth. The calculated tumoristatic concentration, a minimal dose required to balance tumor growth and inhibition, was around 2 mg/kg body weight. Taken together, PCMC1D3-DCM was effective in targeting the inhibition of tumor growth in xenograft models. CONCLUSION: This work provides the basis for the development of humanized PCMC1D3-DCM for MET-targeted cancer therapy in the future.

Duocarmycin-based antibody-drug conjugates as an emerging biotherapeutic entity for targeted cancer therapy: Pharmaceutical strategy and clinical progress.

Duocarmycins are a class of DNA minor-groove-binding alkylating molecules. For the past decade, various duocarmycin analogues have been used as payloads in the development of antibody-drug conjugates (ADCs). Currently, more than 15 duocarmycin-based ADCs have been studied preclinically, and some of them such as SYD985 have been granted Fast-Track Designation status. Nevertheless, progress in duocarmycin-based ADCs also faces challenges, with setbacks including the termination of BMS-936561/MDX-1203. In this review, we discuss issues associated with the efficacy, pharmacokinetic profile, and toxicological activity of these biotherapeutics. Furthermore, we summarize the latest advances in duocarmycin-based ADCs that have different target specificities and linker chemistries. Evidence from preclinical and clinical studies has indicated that duocarmycin-based ADCs are promising biotherapeutics for oncological application in the future.

MET and RON receptor tyrosine kinases in colorectal adenocarcinoma: molecular features as drug targets and antibody-drug conjugates for therapy.

Advanced colorectal adenocarcinoma (CRAC), featured by distinctive histopathological appearance, distant organ metastasis, acquired chemoresistance, and tumorigenic stemness is a group of heterogeneous cancers with unique genetic signatures and malignant phenotypes. Treatment of CRAC is a daunting task for oncologists. Currently, various strategies including molecular targeting using therapeutic monoclonal antibodies, small molecule kinase inhibitors and immunoregulatory checkpoint therapy have been applied to combat this deadly disease. However, these therapeutic modalities and approaches achieve only limited success. Thus, there is a pharmaceutical need to discover new targets and develop novel therapeutics for CRAC therapy. MET and RON receptor tyrosine kinases have been implicated in CRAC pathogenesis. Clinical studies have revealed that aberrant MET and/or RON expression and signaling are critical in regulating CRAC progression and malignant phenotypes. Increased MET and/or RON expression also has prognostic value for CRAC progression and patient survival. These features provide the rationale to target MET and RON for clinical CRAC intervention. At present, the use of small molecule kinase inhibitors targeting MET for CRAC treatment has achieved significant progress with several approvals for clinical application. Nevertheless, antibody-based biotherapeutics, although under clinical trials for more than 8 years, have made very little progress. In this review, we discuss the importance of MET and/or RON in CRAC tumorigenesis and development of anti-MET, anti-RON, and MET and RON-dual targeting antibody-drug conjugates for clinical application. The findings from both preclinical studies and clinical trials highlight the potential of this novel type of biotherapeutics for CRAC therapy in the future.

Progress and challenge in development of biotherapeutics targeting MET receptor for treatment of advanced cancer.

Advanced epithelial cancers such as gastric, lung, and pancreatic tumors are featured by invasive proliferation, distant metastasis, acquired chemoresistance, and tumorigenic stemness. For the last decade, molecular-targeted therapies using therapeutic antibodies, small molecule kinase inhibitors and immune-checkpoint blockades have been applied for these diseases with significant clinical benefits. Nevertheless, there is still a large gap to achieve curative outcomes. MET (mesenchymal-epithelial transition protein), a receptor tyrosine kinase, is a tumorigenic determinant that regulates epithelial cancer initiation, progression, and malignancy. Increased MET expression also has prognostic value for cancer progression and patient survival. These features provide the rationale to target MET for cancer treatment. In this review, we discuss the importance of MET in epithelial tumorigenesis and the development of antibody-based biotherapeutics, including bispecific antibodies and antibody-drug conjugates, for clinical application. The findings from both preclinical and clinical studies highlight the potential of MET-targeted biotherapeutics for cancer therapy in the future.

Immune Responses and Performance Are Influenced by Respiratory Vaccine Antigen Type and Stress in Beef Calves.

The study objective was to determine if a combined weaning and transportation stress model affected performance, antibody, endocrine, or hematological responses to modified-live virus (MLV) or killed virus (KV) respiratory vaccination in beef steers. In total, 48 calves (Day 0 BW = 226 ± 6.2 kg) from a single origin were used in a 2 × 2 factorial to evaluate main effects of stress model, vaccine type, and their interaction, resulting in four treatments (n = 12/treatment) including non-stress control (C) with KV (CKV), C with MLV (CMLV), stress model implementation (S) with KV (SKV), and S with MLV (SMLV). The C calves were weaned at the origin ranch on Day -37 and transported 472 km to the study site on Day -21 to allow acclimation. The S calves were weaned on Day -3, transported 460 km to a research facility on Day -2, held overnight, and transported 164 km to the study site on Day -1 to mimic the beef cattle marketing process. Vaccines were administered on Day 0 and KV was revaccinated on Day 14. The animal was the experimental unit and dependent variables were analyzed using PROC MIXED with repeated measures (day). A stress model effect (p = 0.01) existed for DMI from Day 0 to Day 7 with greater DMI for C (6.19 vs. 4.64 kg/day) when compared to S. The MLV groups had reduced (p = 0.05) ADG from Day 0 to Day 56, compared to KV. There was a vaccine type × day (p < 0.01) interaction with increased (p ≤ 0.01) PI3V- and IBRV-specific antibody titers for KV on Day 21; conversely, MLV had increased (p ≤ 0.01) BVDV titers on Days 14, 28, 35, 42, 49, and 56. Increased (p ≤ 0.05) BRSV titers were observed in a stress model × day (p < 0.01) interaction for S on Days 21, 28, 36, and 42; however, C exceeded S in BVDV-specific antibody concentration on Days 21, 28, and 49. A day effect (p < 0.01) was observed for serum haptoglobin with the greatest (p < 0.01) concentration on Day 3. Serum cortisol concentration was greater (p ≤ 0.04) for C vs. S on Days -2, 0, 1, 3, and 5. Total leukocytes were decreased for C vs. S on Days 0, 1, 3, 5, 7, 14, and 21 (p ≤ 0.02). A reduction (p ≤ 0.04) in total leukocytes was observed for MLV on Days 5, 7, and 14 vs. KV. Neutrophils and neutrophil:lymphocyte were markedly increased (p ≤ 0.01) for S on Day -2, whereas neutrophils were decreased (p ≤ 0.01) on Days 1 and 21 for S. Monocytes were decreased on Days 1, 5 and 7 for MLV (p ≤ 0.04) and Days -2 to 14 for S (p ≤ 0.03). Eosinophils were reduced (p = 0.007) for S vs. C on Day -2, yet a distinct rebound response (p = 0.03) was noted for S on Day 0. The results indicate that S and MLV vaccination more profoundly induced immunomodulation in beef calves.

Antibody-drug conjugates targeting RON receptor tyrosine kinase as a novel strategy for treatment of triple-negative breast cancer.

Treatment of triple-negative breast cancer (TNBC) is a challenge to oncologists. Currently, the lack of effective therapy has fostered a major effort to discover new targets and therapeutics to combat this disease. The recepteur d'origine nantais (RON) receptor has been implicated in the pathogenesis of TNBC. Clinical studies have revealed that aberrant RON expression is crucial in regulating TNBC malignant phenotypes. Increased RON expression also has prognostic value for breast cancer progress. These features provide the rationale to target RON for TNBC treatment. In this review, we discuss the importance of RON in TNBC tumorigenesis and the development of anti-RON antibody-drug conjugates (ADCs) for clinical application. The findings from preclinical studies lay the foundation for clinical trials of this novel biotherapeutic for TNBC therapy.

RON receptor tyrosine kinase in pancreatic ductal adenocarcinoma: Pathogenic mechanism in malignancy and pharmaceutical target for therapy.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers with poor prognosis and high mortality. Molecular aberrations associated with PDAC pathogenesis and progression have been extensively investigated. Nevertheless, these findings have not been translated into clinical practice. Lack of therapeutics for PDAC treatment is another challenge. Recent application of molecularly targeted and immunoregulatory therapies appears to be disappointing. Thus, discovery of new targets and therapeutics is urgently needed to combat this malignant disease. The RON receptor tyrosine kinase is a tumorigenic determinant in PDAC malignancy, which provides the rationale to target RON for PDAC treatment. In this review, we summarize the latest evidence of RON in PDAC pathogenesis and the development of anti-RON antibody-drug conjugates for potential PDAC therapy. The finding that anti-RON antibody-drug conjugates show efficacy in preclinical animal models highlights the potential of this novel class of anti-cancer biotherapeutics in future clinical trials.

Hypospadias surgery in England: Higher volume centres have lower complication rates.

INTRODUCTION: Hypospadias surgery has progressed steadily over recent years. There remains considerable variation in the operative management of boys with hypospadias in the UK, and it is therefore difficult to identify acceptable standards with regards to reoperation rates. OBJECTIVE: To determine the frequency of reoperations and complications from all centres performing hypospadias surgery in England and to identify variables that influence outcome. METHODS: All children undergoing NHS hypospadias surgery in England between 1999 and 2009 were identified using the Hospital Episode Statistics database. Patient demographics, centre type, and associated diagnostic (ICD-10) and treatment codes (OPCS4.6) were collected for both primary repairs and postoperative complications. Centres were classed as high volume if they performed an average of 20 or more operations a year. Operative complications were split into revisions (repeat repairs), repairs of urethral fistulae, repairs of meatal stenosis, or urethral stricture repairs. Statistical analysis included logistic regression, Spearman's correlation, and Mann-Whitney U for non-parametric data, with p < 0.05 taken as significant. Data are presented as median (interquartile range) unless otherwise stated. RESULTS: children underwent a total of 23,962 operations at 75 centres in England during the study period. The median age at primary repair was 21 (15-38) months. The overall complication rate was 18.1%. The median complication rate for individual centres was 20.0% (13.9-27.4%) overall; 10.8% (4.7-15.9%) for revision procedures, 8.1% (5.5-11.7%) for urethral fistulae, 2.3% (1.1-3.7%) for meatal stenosis repairs, and 1.8% (0-2.8%) for urethral strictures. High volume centres had significantly lower complication rates than low volume centres (17.5% vs. 25%, p = 0.01) (Figure), and this was proven to be an independent predictor of outcomes (p = 0.01). Staged repairs were associated with more complications (p < 0.001); however, patient age and centre type were not. Median time to repair of complication was 13 (8-22) months. DISCUSSION: This national population-based study used hospital episode statistics data. While accuracy is high and it has been validated for use in research, it has intrinsic limitations which affect our study. We are unable to fully account for the severity of hypospadias or the number of operating surgeons within institutions. CONCLUSIONS: This study has found a clear relationship between caseload volume and complications following hypospadias surgery. Furthermore, there is significant variability between centres in terms of their surgical outcomes. Taken together these results suggest that surgeons, particularly those in centres with small caseloads should assess their results against such benchmarks when evaluating the service they provide.

A comparison of alternative strategies for cost-effective water quality management in lakes.

Roughly 45% of the assessed lakes in the United States are impaired for one or more reasons. Eutrophication due to excess phosphorus loading is common in many impaired lakes. Various strategies are available to lake residents for addressing declining lake water quality, including septic system upgrades and establishing riparian buffers. This study examines 25 lakes to determine whether septic upgrades or riparian buffers are a more cost-effective strategy to meet a phosphorus reduction target. We find that riparian buffers are the more cost-effective strategy in every case but one. Large transaction costs associated with the negotiation and monitoring of riparian buffers, however, may be prohibiting lake residents from implementing the most cost-effective strategy.