The clinical KRAS(G12C) inhibitor AMG 510 drives anti-tumour immunity.

KRAS is the most frequently mutated oncogene in cancer and encodes a key signalling protein in tumours1,2. The KRAS(G12C) mutant has a cysteine residue that has been exploited to design covalent inhibitors that have promising preclinical activity3-5. Here we optimized a series of inhibitors, using novel binding interactions to markedly enhance their potency and selectivity. Our efforts have led to the discovery of AMG 510, which is, to our knowledge, the first KRAS(G12C) inhibitor in clinical development. In preclinical analyses, treatment with AMG 510 led to the regression of KRASG12C tumours and improved the anti-tumour efficacy of chemotherapy and targeted agents. In immune-competent mice, treatment with AMG 510 resulted in a pro-inflammatory tumour microenvironment and produced durable cures alone as well as in combination with immune-checkpoint inhibitors. Cured mice rejected the growth of isogenic KRASG12D tumours, which suggests adaptive immunity against shared antigens. Furthermore, in clinical trials, AMG 510 demonstrated anti-tumour activity in the first dosing cohorts and represents a potentially transformative therapy for patients for whom effective treatments are lacking.

High incidence of EDNRB gene mutation in seven southern Chinese familial cases with Hirschsprung's disease.

PURPOSE: Hirschsprung's disease (HSCR) is the leading cause of neonatal functional intestinal obstruction, which has been identified in many familial cases. HSCR, a multifactorial disorder of enteric nervous system (ENS) development, is associated with at least 24 genes and seven chromosomal loci, with RET and EDNRB as its major genes. We present a genetic investigation of familial HSCR to clarify the genotype-phenotype relationship. METHODS: We performed whole exome sequencing (WES) on Illumina HiSeq X Ten platform to investigate genetic backgrounds of core family members, and identified the possibly harmful mutation genes. Mutation carriers and pedigree relatives were validated by Sanger sequencing for evaluating the gene penetrance. RESULTS: Four familial cases showed potential disease-relative variants in EDNRB and RET gene, accounting for all detection rate of 57.1%. Three familial cases exhibited strong pathogenic variants as frameshift or missense mutations in EDNRB gene. A novel c.367delinsTT mutation of EDNRB was identified in one family member. The other two EDNRB mutations, c.553G>A in family 2 and c.877delinsTT in family 5, have been reported in previous literatures. The penetrance of EDNRB variants was 33-50% according mutation carries. In family 6, the RET c.1858T>C (C620R) point mutation has previously been reported to cause HSCR, with 28.5% penetrance. CONCLUSION: We identified a novel EDNRB (deleted C and inserted TT) mutation in this study using WES. Heterozygote variations in EDNRB gene were significantly enriched in three families and RET mutations were identified in one family. EDNRB variants showed an overall higher incidence and penetrance than RET in southern Chinese families cases.

Electrostatic Interaction-Induced Aggregation-Induced Emission-Type AgAu Bimetallic Nanoclusters as a Highly Efficient Electrochemiluminescence Emitter for Ultrasensitive Detection of Glial Fibrillary Acidic Protein.

Herein, the aggregation-induced emission (AIE)-type carboxymethyl chitosan (CMCS)@6-aza-2-thiothymine (ATT) templated AgAu bimetallic nanoclusters (CMCS@ATT-AgAu BMNCs) with superior electrochemiluminescence (ECL) emission were first synthesized to construct a biosensor for the ultrasensitive detection of glial fibrillary acidic protein (GFAP). Impressively, unlike the traditional AIE-type bimetallic nanoclusters (BMNCs) obtained by complicated multi-step synthesis, the AIE-type CMCS@ATT-AgAu BMNCs were prepared by the electrostatic interaction between the negatively charged ATT and positively charged CMCS, in which the molecule ATT was served as a capping and reducing agent of bimetal ions. In addition, a rapidly moving cholesterol labeled DNA walker was constructed to move freely on the lipid bilayer to increase its moving efficiency, and the well-regulated DNA was intelligently designed to further improve its walking efficiency for rapid and ultrasensitive detection of GFAP with a limit of detection (LOD) as low as 73 ag/mL. This strategy proposed an avenue to synthesize highly efficient BMNCs-based ECL emitters, which have great potential in ultrasensitive biosensing for early diagnosis of diseases.

Ultrasensitive Electrochemiluminescence Biosensor Based on 2D Co3O4 Nanosheets as a Coreaction Accelerator and Highly Ordered Rolling DNA Nanomachine as a Signal Amplifier for the Detection of MicroRNA.

A novel ultrasensitive electrochemiluminescence (ECL) biosensor was constructed using two-dimensional (2D) Co3O4 nanosheets as a novel coreaction accelerator of the luminol/H2O2 ECL system for the detection of microRNA-21 (miRNA-21). Impressively, coreaction accelerator 2D Co3O4 nanosheets with effective mutual conversion of the Co2+/Co3+ redox pair and abundant active sites could promote the decomposition of coreactant H2O2 to generate more superoxide anion radicals (O2•-), which reacted with luminol for significantly enhancing ECL signals. Furthermore, the trace target miRNA-21 was transformed into a large number of G-wires through the strand displacement amplification (SDA) process to self-assemble the highly ordered rolling DNA nanomachine (HORDNM), which could tremendously improve the detection sensitivity of biosensors. Hence, on the basis of the novel luminol/H2O2/2D Co3O4 nanosheet ternary ECL system, the biosensor implemented ultrasensitive detection of miRNA-21 with a detection limit as low as 4.1 aM, which provided a novel strategy to design an effective ECL emitter for ultrasensitive detection of biomarkers for early disease diagnosis.

Thickness measurement of cell walls of closed-cell foams in micro-CT images.

Characterising the microstructure of foams is an important task for improving foam manufacturing processes and building foam numerical models. This study proposed a method for measuring the thickness of individual cell walls of closed-cell foams in micro-CT images. It comprises a distance transform on CT images to obtain thickness information of cell walls, a watershed transform on the distance matrix to locate the midlines of cell walls, identifying the intersections of midlines of cell walls by examining how many regions each pixel on the midlines of cell walls connects with, disconnecting and numbering the midlines of cell walls, extracting the distance values of the pixels on the midlines (or midplanes) of cell walls, and calculating the thickness of individual cell walls by multiplying the extracted distance values by two. Using this method, the thickness of cell walls of a polymeric closed-cell foam was measured. It was found that cell wall thickness measured in 2D images shows larger average values (around 1.5 times) and dispersion compared to that measured in volumetric images.

Oncogenic BRAF induces senescence and apoptosis through pathways mediated by the secreted protein IGFBP7.

Expression of an oncogene in a primary cell can, paradoxically, block proliferation by inducing senescence or apoptosis through pathways that remain to be elucidated. Here we perform genome-wide RNA-interference screening to identify 17 genes required for an activated BRAF oncogene (BRAFV600E) to block proliferation of human primary fibroblasts and melanocytes. Surprisingly, we find a secreted protein, IGFBP7, has a central role in BRAFV600E-mediated senescence and apoptosis. Expression of BRAFV600E in primary cells leads to synthesis and secretion of IGFBP7, which acts through autocrine/paracrine pathways to inhibit BRAF-MEK-ERK signaling and induce senescence and apoptosis. Apoptosis results from IGFBP7-mediated upregulation of BNIP3L, a proapoptotic BCL2 family protein. Recombinant IGFBP7 (rIGFBP7) induces apoptosis in BRAFV600E-positive human melanoma cell lines, and systemically administered rIGFBP7 markedly suppresses growth of BRAFV600E-positive tumors in xenografted mice. Immunohistochemical analysis of human skin, nevi, and melanoma samples implicates loss of IGFBP7 expression as a critical step in melanoma genesis.

Ulinastatin ameliorates the malignant progression of prostate cancer cells by blocking the RhoA/ROCK/NLRP3 pathway.

Prostate cancer is a male malignant tumor disease with high incidence and mortality. This study was designed to explore the effects of ulinastatin (UTI) on the malignant progression of prostate cancer and its relevant mechanism of action. Human prostate cancer cell line PC-3 was applied to investigate the anticancer activity of UTI. PC-3 cells were treated with increasing concentrations (400, 800, and 1600 U/ml) of UTI. Cell proliferation, migration, invasion, and apoptosis were determined by cell counting kit-8 (CCK-8), colony formation, wound-healing, Transwell assay, and flow cytometry analysis, respectively. The expression level of corresponding proteins was detected by western blot. In addition, PC-3 cells were pretreated with RhoA agonist CN03 (1 µg/ml) or NLRP3 agonist nigericin (10 µM) before UTI treatment, and the cellular behaviors above were detected again. It was demonstrated that UTI significantly suppressed cell proliferation, migration, and invasion but promoted apoptosis in PC-3 cells in a concentration-dependent manner. Meanwhile, UTI could block RhoA/ROCK/NLRP3 inflammasome pathway in PC-3 cells, and the activation of RhoA or NLRP3 inflammasome partly weakened the impacts of UTI on cell proliferation, migration, and apoptosis in PC-3 cells, respectively. In summary, our study demonstrated the antitumor activity of UTI against prostate cancer by regulating RhoA/NLRP3 inflammasome pathway, providing a promising candidate drug for the therapeutic treatment of prostate cancer.

Two Novel, Nonoperative Methods of Stoma Prolapse in Newborns: 3 Case Reports.

BACKGROUND: Prolapse is a common complication following enterostomy; the defect and consequences of a prolapse significantly affect health-related quality of life. Creative techniques must be employed to manage the prolapse. CASES: This article describes management of 3 neonates with stoma prolapse. CONCLUSION: Management of stoma prolapse should be individualized, employing successful nonoperative techniques rather than more difficult operative procedures to prevent recurrent prolapse.

Leflunomide versus azathioprine for maintenance therapy of lupus nephritis: a prospective, multicentre, randomised trial and long-term follow-up.

OBJECTIVES: Previous studies have compared mycophenolate mofetil and azathioprine as maintenance therapy for lupus nephritis (LN). Leflunomide is an immunosuppressant widely used in the treatment of rheumatoid arthritis. The aim of this investigator-initiated study was to compare the efficacy and safety of leflunomide versus azathioprine as maintenance therapy for LN. METHODS: 270 adult patients with biopsy-confirmed active LN from 7 Chinese Rheumatology Centres were enrolled. All patients received induction therapy with 6-9 months of intravenous cyclophosphamide plus glucocorticoids. Patients who achieved complete response (CR) or partial response (PR) were randomised to receive prednisone in combination with leflunomide or azathioprine as maintenance therapy for 36 months. The primary efficacy endpoint was the time to kidney flare. Secondary outcomes included clinical parameters, extrarenal flare and adverse effects. RESULTS: A total of 215 patients were randomly allocated to the leflunomide group (n=108) and azathioprine group (n=107). Kidney flares were observed in 17 (15.7%) leflunomide-treated patients and 19 (17.8%) azathioprine-treated patients. Time to kidney flare did not statistically differ (leflunomide: 16 months vs azathioprine: 14 months, p=0.676). 24-hour proteinuria, serum creatinine, serum albumin, serum C3 and serum C4 improved similarly. Extrarenal flare occurred in two patients from the azathioprine group and one patient from the leflunomide group. The incidence of adverse events was similar in the 2 groups: leflunomide 56.5% and azathioprine 58.9%. CONCLUSIONS: The efficacy and safety profile of leflunomide are non-inferior to azathioprine for maintenance therapy of LN. Leflunomide may provide a new candidate for maintenance therapy in patients with LN. TRIAL REGISTRATION NUMBER: NCT01172002.

Determination of Acyl-, O-, and N-Glucuronide Using Chemical Derivatization Coupled with Liquid Chromatography-High-Resolution Mass Spectrometry.

Glucuronidation is the most common phase II metabolic pathway to eliminate small molecule drugs from the body. However, determination of glucuronide structure is quite challenging by mass spectrometry due to its inability to generate structure-informative fragments about the site of glucuronidation. In this article, we describe a simple method to differentiate acyl-, O-, and N-glucuronides using chemical derivatization. The idea is that derivatization of acyl-, O-, or N-glucuronides of a molecule results in predictable and different numbers of derivatized functional groups, which can be determined by the mass shift using mass spectrometry. The following two reactions were applied to specifically derivatize carboxyl and hydroxyl groups that are present on the aglycone and its glucuronide metabolite: Carboxyl groups were activated by thionyl chloride followed by esterification with ethanol. Hydroxyl groups were derivatized via silylation by 1-(trimethylsilyl)imidazole. The mass shift per derivatized carboxyl and hydroxyl group was +28.031 Da and +72.040 Da, respectively. This approach was successfully validated using commercial glucuronide standards, including benazepril acyl-glucuronides, raloxifene O-glucuronide, and silodosin O-glucuronide. In addition, this approach was applied to determine the type of glucuronide metabolites that were isolated from liver microsomal incubation, where alvimopan and diclofenac acyl-glucuronides; darunavir, haloperidol, and propranolol O-glucuronides; and darunavir N-glucuronide were identified. Lastly, this approach was successfully used to elucidate the definitive structure of a clinically observed metabolite, soticlestat O-glucuronide. In conclusion, a novel, efficient, and cost-effective approach was developed to determine acyl-, O-, and N-glucuronides using chemical derivatization coupled with liquid chromatography-high resolution mass spectrometry. SIGNIFICANCE STATEMENT: The method described in this study can differentiate acyl-, O-, and N-glucuronides and allow for elucidation of glucuronide structures when multiple glucuronidation possibilities exist. The type of glucuronidation information is particularly useful for a drug candidate containing carboxyl groups, which can form reactive acyl-glucuronides. Additionally, the method can potentially be used for definitive structure elucidation for a glucuronide with its aglycone containing a single carboxyl, hydroxyl, or amino group even when multiple types of functional groups are present for glucuronidation.

Absorption, Distribution, Metabolism, and Excretion of Therapeutic Proteins: Current Industry Practices and Future Perspectives.

Therapeutic proteins (TPs) comprise a variety of modalities, including antibody-based drugs, coagulation factors, recombinant cytokines, enzymes, growth factors, and hormones. TPs usually cannot traverse cellular barriers and exert their pharmacological activity by interacting with targets on the exterior membrane of cells or with soluble ligands in the tissue interstitial fluid/blood. Due to their large size, lack of cellular permeability, variation in metabolic fate, and distinct physicochemical characteristics, TPs are subject to different absorption, distribution, metabolism, and excretion (ADME) processes as compared with small molecules. Limited regulatory guidance makes it challenging to determine the most relevant ADME data required for regulatory submissions. The TP ADME working group was sponsored by the Translational and ADME Sciences Leadership Group within the Innovation and Quality (IQ) consortium with objectives to: (1) better understand the current practices of ADME data generated for TPs across IQ member companies, (2) learn about their regulatory strategies and interaction experiences, and (3) provide recommendations on best practices for conducting ADME studies for TPs. To understand current ADME practices and regulatory strategies, an industry-wide survey was conducted within IQ member companies. In addition, ADME data submitted to the U.S. Food and Drug Administration was also collated by reviewing regulatory submission packages of TPs approved between 2011 and 2020. This article summarizes the key learnings from the survey and an overview of ADME data presented in biologics license applications along with future perspectives and recommendations for conducting ADME studies for internal decision-making as well as regulatory submissions for TPs. SIGNIFICANCE STATEMENT: This article provides comprehensive assessment of the current practices of absorption, distribution, metabolism, and excretion (ADME) data generated for therapeutic proteins (TPs) across the Innovation and Quality participating companies and the utility of the data in discovery, development, and regulatory submissions. The TP ADME working group also recommends the best practices for condu-cting ADME studies for internal decision-making and regulatory submissions.

A Cross Company Perspective on the Assessment of Therapeutic Protein Biotransformation.

Unlike with new chemical entities, the biotransformation of therapeutic proteins (TPs) has not been routinely investigated or included in regulatory filings. Nevertheless, there is an expanding pool of evidence suggesting that a more in-depth understanding of biotransformation could better aid the discovery and development of increasingly diverse modalities. For instance, such biotransformation analysis of TPs affords important information on molecular stability, which in turn may shed light on any potential impact on binding affinity, potency, pharmacokinetics, efficacy, safety, or bioanalysis. This perspective summarizes the current practices in studying biotransformation of TPs and related findings in the biopharmaceutical industry. Various TP case studies are discussed, and a fit-for-purpose approach is recommended when investigating their biotransformation. In addition, we provide a decision tree to guide the biotransformation characterization for selected modalities. By raising the awareness of this important topic, which remains relatively underexplored in the development of TPs (Bolleddula et al., 2022), we hope that current and developing practices can pave the way for establishing a consensus on the biotransformation assessment of TPs. SIGNIFICANCE STATEMENT: This article provides a comprehensive perspective of the current practices for exploring the biotransformation of therapeutic proteins across the drug development industry. We, the participants of the Innovation and Quality therapeutic protein absorption distribution metabolism excretion working group, recommend and summarize appropriate approaches for conducting biotransformation studies to support internal decision making based on the data generated in discovery and development.

Monitoring the Production Information of Conventional Machining Equipment Based on Edge Computing.

A production status monitoring method based on edge computing is proposed for traditional machining offline equipment to address the deficiencies that traditional machining offline equipment have, which cannot automatically count the number of parts produced, obtain part processing time information, and discern anomalous operation status. Firstly, the total current signal of the collected equipment was filtered to extract the processing segment data. The processing segment data were then used to manually calibrate the feature vector of the equipment for specific parts and processes, and the feature vector was used as a reference to match with the real-time electric current data on the edge device to identify and obtain the processing start time, processing end time, and anomalous marks for each part. Finally, the information was uploaded to further obtain the part processing time, loading and unloading standby time, and the cause of the anomaly. To verify the reliability of the method, a prototype system was built, and extensive experiments were conducted on many different types of equipment in an auto parts manufacturer. The experimental results show that the proposed monitoring algorithm based on the calibration vector can stably and effectively identify the production information of each part on an independently developed edge device.

High-Efficient Electrochemiluminescence of Au Nanoclusters Induced by the Electrosensitizer Cu2O: The Mechanism Insights from the Electrogenerated Process.

Herein, a novel Au nanoclusters/Cu2O (Au NCs/Cu2O) heterostructure exhibited exceptionally strong electrochemiluminescence (ECL) emission, in which the p-type semiconductor Cu2O was defined as the electrosensitizer to provide the electrogenerated holes for rapidly transferring the electrogenerated hot electrons of Au NCs. Thus, the fast charge transfer of Au NCs/Cu2O was achieved by the electrosensitizer compared to the sluggish one via intramolecular covalent bond charge transfer of traditional Au NCs, resulting in a greatly higher ECL efficiency (63.8%) than that of pure Au NCs (2.7%) versus the standard [Ru(bpy)3]2+. It solved one main challenge of electrochemiluminophore-based metal NCs: high efficiency with energic charge-transport kinetics. As a proof of concept, Au NCs/Cu2O was successfully employed in an ultrasensitive ECL biosensing platform for determining the biological antioxidant glutathione with a limit of detection (LOD) as low as 6.3 pM. The heterostructure as an ECL emitter is a very promising start for guiding the rational design of efficient electrochemiluminophores in intense light-emitting devices and high-definition ECL imaging.

New sonographic feature (C-sign) to improve the prenatal accuracy of jejunal atresia.

OBJECTIVES: To describe a new sonographic feature of the C-sign for prenatal diagnosis of jejunal atresia and evaluate its role in prenatal jejunal atresia, particularly preceding bowel dilatation and polyhydramnios. METHODS: This was a retrospective study from a tertiary maternal hospital. Patients with prenatal sonographic examination and confirmed small bowel atresia postdelivery were included. All sonographic images were reviewed by two senior sonographers. Comparison of sonographic images between prenatal jejunal and ileal atresia using the C-sign resembles the shape of the entire duodenum and other traditional sonographic features. The control group without bowel atresia was assessed for the presence of the C-sign. RESULTS: The C-sign and combined bowel dilatation with polyhydramnios were more frequent in jejunal atresia than ileal atresia, but the C-sign can be used to detect jejunal atresia earlier. The C-sign can be more likely to diagnose jejunal atresia in persisting bowel dilatation and polyhydramnios. The C-sign was not reported in any of the control fetuses. CONCLUSION: The C-sign is a new sonographic feature that can be used to improve the prenatal accuracy and early detection of jejunal atresia. However, further prospective validation is needed.

Water Extraction Method Based on Multi-Texture Feature Fusion of Synthetic Aperture Radar Images.

Lakes play an important role in the water ecosystem on earth, and are vulnerable to climate change and human activities. Thus, the detection of water quality changes is of great significance for ecosystem assessment, disaster warning and water conservancy projects. In this paper, the dynamic changes of the Poyang Lake are monitored by Synthetic Aperture Radar (SAR). In order to extract water from SAR images to monitor water change, a water extraction algorithm composed of texture feature extraction, feature fusion and target segmentation was proposed. Firstly, the fractal dimension and lacunarity were calculated to construct the texture feature set of a water object. Then, an iterated function system (IFS) was constructed to fuse texture features into composite feature vectors. Finally, lake water was segmented by the multifractal spectrum method. Experimental results showed that the proposed algorithm accurately extracted water targets from SAR images of different regions and different imaging modes. Compared with common algorithms such as fuzzy C-means (FCM), the accuracy of the proposed algorithm is significantly improved, with an accuracy of over 98%. Moreover, the proposed algorithm can accurately segment complex coastlines with mountain shadow interference. In addition, the dynamic analysis of the changes of the water area of the Poyang Lake Basin was carried out with the local hydrological data. It showed that the extracted results of the algorithm in this paper are a good match with the hydrological data. This study provides an accurate monitoring method for lake water under complex backgrounds.

Circular RNA sequencing indicates circ-IQGAP2 and circ-ZC3H6 as noninvasive biomarkers of primary Sjögren's syndrome.

OBJECTIVES: This study aims to characterize the expression profiles of circRNAs in primary Sjogren's Syndrome (pSS) and examine the potential of noninvasive circular RNAs (circRNAs) as biomarkers of pSS. METHODS: We performed RNA sequencing of minor salivary gland (MSG) biopsies from four pSS and four non-pSS individuals (subjects undergoing MSG biopsies but not meeting 2012 or 2016 ACR classification criteria for SS). Differentially expressed circRNAs were identified by DESeq2, and confirmed by quantitative real-time PCR in the MSGs as well as in plasma exosomes in 37 pSS and 14 non-pSS subjects. Discriminatory capacity testing using receiver operating characteristic analysis was used to evaluate the performance of circRNAs as diagnostic biomarkers for pSS. RESULTS: Circ-IQGAP2 and circ-ZC3H6 had significantly upregulated expression in the MSGs of pSS patients, and this elevated expression was confirmed by quantitative real-time PCR of plasma exosome RNA. The expression of these circRNAs also showed significant correlation with both clinical features, serum IgG level and MSG focus scores. Receiver operating characteristic analysis showed that the indices comprised of both the two circRNAs and clinical features were better able to distinguish pSS from non-pSS subjects with high mean areas under the curve of 0.93 in the MSGs and 0.92 in the plasma exosomes. CONCLUSION: This study indicated the potential roles of circ-IQGAP2 and circ-ZC3H6 as noninvasive biomarkers for the diagnosis of pSS.

Exome chip analyses identify genes affecting mortality after HLA-matched unrelated-donor blood and marrow transplantation.

Although survival outcomes have significantly improved, up to 40% of patients die within 1 year of HLA-matched unrelated-donor blood and marrow transplantation (BMT). To identify non-HLA genetic contributors to mortality after BMT, we performed the first exome-wide association study in the DISCOVeRY-BMT cohorts using the Illumina HumanExome BeadChip. This study includes 2473 patients with acute myeloid leukemia, acute lymphoblastic leukemia, or myelodysplastic syndrome and 2221 10/10 HLA-matched donors treated from 2000 to 2011. Single-variant and gene-level analyses were performed on overall survival (OS), transplantation-related mortality (TRM), and disease-related mortality (DRM). Genotype mismatches between recipients and donors in a rare nonsynonymous variant of testis-expressed gene TEX38 significantly increased risk of TRM, which was more dramatic when either the recipient or donor was female. Using the SKAT-O test to evaluate gene-level effects, variant genotypes of OR51D1 in recipients were significantly associated with OS and TRM. In donors, 4 (ALPP, EMID1, SLC44A5, LRP1), 1 (HHAT), and 2 genes (LYZL4, NT5E) were significantly associated with OS, TRM, and DRM, respectively. Inspection of NT5E crystal structures showed 4 of the associated variants affected the enzyme structure and likely decreased the catalytic efficiency of the enzyme. Further confirmation of these findings and additional functional studies may provide individualized risk prediction and prognosis, as well as alternative donor selection strategies.

Prediction of Human Disproportionate and Biliary Excreted Metabolites Using Chimeric Mice with Humanized Liver.

The PXB-mouse is potentially a useful in vivo model to predict human hepatic metabolism and clearance. Four model compounds, [14C]desloratadine, [3H]mianserin, cyproheptadine, and [3H]carbazeran, all reported with disproportionate human metabolites, were orally administered to PXB- or control SCID mice to elucidate the biotransformation of each of them. For [14C]desloratadine in PXB-mice, O-glucuronide of 3-hydroxydesloratadine was observed as the predominant metabolite in both the plasma and urine. Both 3-hydroxydesloratadine and its O-glucuronide were detected as major drug-related materials in the bile, whereas only 3-hydroxydesloratadine was detected in the feces, suggesting that a fraction of 3-hydroxydesloratadine in feces was derived from deconjugation of its O-glucuronide by gut microflora. This information can help understand the biliary clearance mechanism of a drug and may fill the gap in a human absorption, distribution, metabolism, and excretion study, in which the bile samples are typically not available. The metabolic profiles in PXB-mice were qualitatively similar to those reported in humans in a clinical study in which 3-hydroxydesloratadine and its O-glucuronide were major and disproportionate metabolites compared with rat, mouse, and monkey. In the control SCID mice, neither of the metabolites was detected in any matrix. Similarly, for the other three compounds, all human specific or disproportionate metabolites were detected at a high level in PXB-mice, but they were either minimally observed or not observed in the control mice. Data from these four compounds indicate that studies in PXB-mice can help predict the potential for the presence of human disproportionate metabolites (relative to preclinical species) prior to conducting clinical studies and understand the biliary clearance mechanism of a drug. SIGNIFICANCE STATEMENT: Studies in PXB-mice have successfully predicted the human major and disproportionate metabolites compared with preclinical safety species for desloratadine, mianserin, cyproheptadine, and carbazeran. In addition, biliary excretion data from PXB-mice can help illustrate the human biliary clearance mechanism of a drug.