ABSTRACT
Elevated concentrations of As, Cr, Cu, Ni, Pb, V and Zn in topsoils in Belfast, Northern Ireland have been found to exceed assessment criteria in the city and therefore may pose a risk to human health. Most generic assessment criteria (GAC) for potentially toxic elements (PTEs) in soils assume PTEs are 100% bioavailable to humans. Here we use in-vitro oral bioaccessibility testing using the Unified BARGE method (UBM) to measure what proportion of soil contamination dissolves in the digestive tract and therefore is available for absorption by the body. This study considers how PTE bioaccessibility in soils varies spatially across urban areas and refines human health risk assessment for these PTEs using site specific oral bioaccessibility results to present the first regional assessment of risk that incorporates bioaccessibility testing. A total of 103 urban soil samples were selected for UBM testing. Results showed low bioaccessible fraction (BAF) for the PTEs from geogenic sources: Cr (0.45-5.9%), Ni (1.1-46.3%) and V (2.2-23.9%). Higher BAF values were registered for PTEs from anthropogenic sources: As (8.0-86.9%), Cu (3.4-67.8%), Pb (9.1-106.2%) and Zn (2.4-77.5%). Graphs of bioaccessibility adjusted assessment criteria (BAAC) were derived for each urban land use type and PTE. These provide a visual representation of the significance of oral bioaccessibility when deriving BAAC and how this is affected by 1) dominant exposure pathways for each land use and 2) relative harm posed from exposure to PTEs via each pathway, allowing oral bioaccessibility research to be targeted to contaminants and pathways that most significantly impact risk assessment. Pb was the most widespread contaminant with 16.5% of sites exceeding the Pb GAC. Applying BAAC did not significantly change risk evaluation for these samples as many had Pb BAF>50%. In contrast, all samples that exceeded the As GAC were found to no longer exceed a minimal level of risk when oral bioaccessibility was considered. Oral bioaccessibility testing resulted in a 45% reduction in the number of sites identified as posing a potential risk to human health.
Subject(s)
Biological Availability , Environmental Monitoring , Metals, Heavy , Soil Pollutants , Risk Assessment , Soil Pollutants/analysis , Northern Ireland , Humans , Environmental Monitoring/methods , Metals, Heavy/analysis , Cities , Soil/chemistryABSTRACT
The goal of this study was to develop a methylation-based droplet digital PCR to separate 2 cancer classes that do not have sensitive and specific immunohistochemical stains: gastric/esophageal and pancreatic adenocarcinomas. The assay used methylation-independent primers and methylation-dependent probes to assess a single differentially methylated CpG site; analyses of array data from The Cancer Genome Atlas network showed that high methylation at the cg06118999 probe supports the presence of cells originating from the stomach or esophagus (eg, as in gastric metastasis), whereas low methylation suggests that these cells are rare to absent (eg, pancreatic metastasis). On validation using formalin-fixed paraffin-embedded primary and metastatic samples from our institution, methylation-based droplet digital PCR targeting the corresponding CpG dinucleotide generated evaluable data for 60 of the 62 samples (97%) and correctly classified 50 of the 60 evaluable cases (83.3%), mostly adenocarcinomas from the stomach or pancreas. This ddPCR was created to be easy-to-interpret, rapid, inexpensive, and compatible with existing platforms at many clinical laboratories. We suggest that similarly accessible PCRs could be developed for other differentials in pathology that do not have sensitive and specific immunohistochemical stains.
Subject(s)
Adenocarcinoma , Pancreatic Neoplasms , Stomach Neoplasms , Humans , Adenocarcinoma/diagnosis , Adenocarcinoma/genetics , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/genetics , DNA Methylation , Polymerase Chain Reaction , Stomach Neoplasms/diagnosis , Stomach Neoplasms/genetics , Esophagus , Pancreatic NeoplasmsABSTRACT
Prostate tumours are highly variable in their response to therapies, but clinically available prognostic factors can explain only a fraction of this heterogeneity. Here we analysed 200 whole-genome sequences and 277 additional whole-exome sequences from localized, non-indolent prostate tumours with similar clinical risk profiles, and carried out RNA and methylation analyses in a subset. These tumours had a paucity of clinically actionable single nucleotide variants, unlike those seen in metastatic disease. Rather, a significant proportion of tumours harboured recurrent non-coding aberrations, large-scale genomic rearrangements, and alterations in which an inversion repressed transcription within its boundaries. Local hypermutation events were frequent, and correlated with specific genomic profiles. Numerous molecular aberrations were prognostic for disease recurrence, including several DNA methylation events, and a signature comprised of these aberrations outperformed well-described prognostic biomarkers. We suggest that intensified treatment of genomically aggressive localized prostate cancer may improve cure rates.
Subject(s)
Genome, Human/genetics , Genomics , Mutation , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Chromothripsis , DNA Copy Number Variations , DNA Methylation , Exome/genetics , Humans , Male , Neoplasm Metastasis/genetics , Prognosis , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/pathology , RecurrenceABSTRACT
BACKGROUND: Studies have demonstrated that a culturally and linguistically tailored Diabetes Prevention Program (DPP) can be effective in reducing diabetes risk in Chinese Americans. The purpose of this study was to explore the cultural and linguistic acceptability of the Centers for Disease Control and Prevention's Prevent T2 curriculum in an online format in the Chinese American community in New York City (NYC). METHODS: Three focus groups among a total of 24 Chinese Americans with prediabetes and one community advisory board (CAB) meeting with 10 key stakeholders with expertise in diabetes care and lifestyle interventions were conducted. Each focus group lasted approximately 1 to 1.5 h. All groups were moderated by a bilingual moderator in Chinese. The sessions were audiotaped, transcribed and translated to English for analysis. Using Atlas.ti software and open coding techniques, two researchers analyzed transcripts for thematic analysis. RESULTS: Five key themes were identified: barriers to behavioral changes, feedback on curriculum content and suggestions, web-based intervention acceptability, web-based intervention feasibility, and web-based intervention implementation and modifications. Participants with prediabetes were found to have high acceptability of web-based DPP interventions. Suggestions for the curriculum included incorporating Chinese American cultural foods and replacing photos of non-Asians with photos of Asians. Barriers included lack of access to the internet, different learning styles and low technology self-efficacy for older adults. CONCLUSION: Although the acceptability of web-based DPP in the Chinese American community in NYC is high, our focus group findings indicated that the major concern is lack of internet access and technical support. Providing support, such as creating an orientation manual for easy online program access for future participants, is important.
Subject(s)
Diabetes Mellitus, Type 2 , Prediabetic State , Aged , Asian , Diabetes Mellitus, Type 2/prevention & control , Humans , Life Style , Prediabetic State/therapy , Qualitative ResearchABSTRACT
BACKGROUND: The Western Pacific Region (WPR) is exposed each year to seasonal influenza and is often the source of new influenza virus variants and novel pathogen emergence. National influenza surveillance systems play a critical role in detecting emerging viruses, monitoring influenza epidemics, improving public disease awareness and promoting pandemic preparedness, but vary widely across WPR countries. The aim of this study is to improve existing influenza surveillance systems by systematically comparing selected WPR influenza surveillance systems. METHODS: Three national influenza surveillance systems with different levels of development (Australia, China and Malaysia) were compared and their adherence to World Health Organization (WHO) guidance was evaluated using a structured framework previously tested in several European countries consisting of seven surveillance sub-systems, 19 comparable outcomes and five evaluation criteria. Based on the results, experts from the Asia-Pacific Alliance for the Control of Influenza (APACI) issued recommendations for the improvement of existing surveillance systems. RESULTS: Australia demonstrated the broadest scope of influenza surveillance followed by China and Malaysia. In Australia, surveillance tools covered all sub-systems. In China, surveillance did not cover non-medically attended respiratory events, primary care consultations, and excess mortality modelling. In Malaysia, surveillance consisted of primary care and hospital sentinel schemes. There were disparities between the countries across the 5 evaluation criteria, particularly regarding data granularity from health authorities, information on data representativeness, and data communication, especially the absence of publicly available influenza epidemiological reports in Malaysia. This dual approach describing the scope of surveillance and evaluating the adherence to WHO guidance enabled APACI experts to make a number of recommendations for each country that included but were not limited to introducing new surveillance tools, broadening the use of specific existing surveillance tools, collecting and sharing data on virus characteristics, developing immunization status registries, and improving public health communication. CONCLUSIONS: Influenza monitoring in Australia, China, and Malaysia could benefit from the expansion of existing surveillance sentinel schemes, the broadened use of laboratory confirmation and the introduction of excess-mortality modelling. The results from the evaluation can be used as a basis to support expert recommendations and to enhance influenza surveillance capabilities.
Subject(s)
Influenza, Human , Orthomyxoviridae , Australia/epidemiology , China/epidemiology , Humans , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Malaysia/epidemiologyABSTRACT
Cell-free DNA in human plasma is nonrandomly fragmented and reflects genomewide nucleosomal organization. Previous studies had demonstrated tissue-specific preferred end sites in plasma DNA of pregnant women. In this study, we performed integrative analysis of preferred end sites with the size characteristics of plasma DNA fragments. We mined the preferred end sites in short and long plasma DNA molecules separately and found that these "size-tagged" ends showed improved accuracy in fetal DNA fraction estimation and enhanced noninvasive fetal trisomy 21 testing. Further analysis revealed that the fetal and maternal preferred ends were generated from different locations within the nucleosomal structure. Hence, fetal DNA was frequently cut within the nucleosome core while maternal DNA was mostly cut within the linker region. We further demonstrated that the nucleosome accessibility in placental cells was higher than that for white blood cells, which might explain the difference in the cutting positions and the shortness of fetal DNA in maternal plasma. Interestingly, short and long size-tagged ends were also observable in the plasma of nonpregnant healthy subjects and demonstrated size differences similar to those in the pregnant samples. Because the nonpregnant samples did not contain fetal DNA, the data suggested that the interrelationship of preferred DNA ends, chromatin accessibility, and plasma DNA size profile is likely a general one, extending beyond the context of pregnancy. Plasma DNA fragment end patterns have thus shed light on production mechanisms and show utility in future developments in plasma DNA-based noninvasive molecular diagnostics.
Subject(s)
Cell-Free Nucleic Acids/blood , Molecular Diagnostic Techniques/methods , Prenatal Diagnosis/methods , Case-Control Studies , Cell-Free Nucleic Acids/classification , Female , Fetus/physiology , Humans , Liquid Biopsy , Nucleosomes/chemistry , PregnancyABSTRACT
OBJECTIVE: Cognitive side effects are a common unintended outcome of electroconvulsive therapy (ECT). Routine cognitive assessment is important for monitoring patient outcomes, although it can pose challenges in busy clinical settings. Computerized cognitive testing has advantages that can facilitate routine monitoring. This study explored the construct and criterion validity of computerized cognitive testing compared with standard pen-and-paper tests for monitoring cognition in ECT patients. METHODS: The study included 24 participants with major depression who received an acute course of ECT. Cognition was assessed at pretreatment and at posttreatment with 3 computerized tests from the CogState battery (International Shopping List task, One-Card Learning, and One-Back Task) and 3 conceptually matched pen-and-paper-administered neuropsychological tests. RESULTS: At pretreatment, only performance on the computer-administered test of verbal anterograde memory (International Shopping List task) was significantly correlated with the analogous pen-and-paper measure, whereas the other computerized tests were not. Of the computerized measures, only the International Shopping List task showed significant changes from pretreatment to posttreatment (P < 0.01, Cohen d > 1.0). In contrast, all the pen-and-paper-administered tests showed significant changes from pretreatment to posttreatment (P < 0.01, Cohen d range, 0.8-1.2). Pretreatment to posttreatment cognitive changes on the computerized measures were not correlated with changes on the pen-and-paper-administered tests. CONCLUSION: Construct and criterion validity and tolerability varied between the computerized measures. The results highlighted potentially important issues related to the interpretation and utility of computerized tests in this patient population.
Subject(s)
Cognition Disorders/diagnosis , Depressive Disorder, Major/therapy , Diagnosis, Computer-Assisted/methods , Electroconvulsive Therapy/adverse effects , Neuropsychological Tests , Humans , Male , Middle AgedABSTRACT
The aryl hydrocarbon receptor (AHR) mediates many toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). However, the AHR alone does not explain the widely different outcomes among organisms. To identify the other factors involved, we evaluated three transgenic mouse lines, each expressing a different rat AHR isoform (rWT, DEL, and INS) providing widely different resistance to TCDD toxicity, as well as C57BL/6 and DBA/2 mice which exhibit a ~ tenfold divergence in TCDD sensitivity (exposures of 5-1000 µg/kg TCDD). We supplement these with whole-genome sequencing, together with transcriptomic and proteomic analyses of the corresponding rat models, Long-Evans (L-E) and Han/Wistar (H/W) rats (having a ~ 1000-fold difference in their TCDD sensitivities; 100 µg/kg TCDD), to identify genes associated with TCDD-response phenotypes. Overall, we identified up to 50% of genes with altered mRNA abundance following TCDD exposure are associated with a single AHR isoform (33.8%, 11.7%, 5.2% and 0.3% of 3076 genes altered unique to rWT, DEL, C57BL/6 and INS respectively following 1000 µg/kg TCDD). Hepatic Pxdc1 was significantly repressed in all three TCDD-sensitive animal models (C57BL/6 and rWT mice, and L-E rat) after TCDD exposure. Three genes, including Cxxc5, Sugp1 and Hgfac, demonstrated different AHRE-1 (full) motif occurrences within their promoter regions between rat strains, as well as different patterns of mRNA abundance. Several hepatic proteins showed parallel up- or downward alterations with their RNAs, with three genes (SNRK, IGTP and IMPA2) showing consistent, strain-dependent changes. These data show the value of integrating genomic, transcriptomic and proteomic evidence across multi-species models in toxicologic studies.
Subject(s)
Basic Helix-Loop-Helix Transcription Factors/genetics , Environmental Pollutants/toxicity , Liver/metabolism , Polychlorinated Dibenzodioxins/toxicity , Receptors, Aryl Hydrocarbon/genetics , Animals , Dose-Response Relationship, Drug , Environmental Pollutants/administration & dosage , Genomics , Male , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Mice, Transgenic , Polychlorinated Dibenzodioxins/administration & dosage , Proteomics , RNA, Messenger/genetics , Rats , Rats, Long-Evans , Rats, Wistar , Species Specificity , TranscriptomeABSTRACT
Plasma DNA obtained from a pregnant woman was sequenced to a depth of 270× haploid genome coverage. Comparing the maternal plasma DNA sequencing data with the parental genomic DNA data and using a series of bioinformatics filters, fetal de novo mutations were detected at a sensitivity of 85% and a positive predictive value of 74%. These results represent a 169-fold improvement in the positive predictive value over previous attempts. Improvements in the interpretation of the sequence information of every base position in the genome allowed us to interrogate the maternal inheritance of the fetus for 618,271 of 656,676 (94.2%) heterozygous SNPs within the maternal genome. The fetal genotype at each of these sites was deduced individually, unlike previously, where the inheritance was determined for a collection of sites within a haplotype. These results represent a 90-fold enhancement in the resolution in determining the fetus's maternal inheritance. Selected genomic locations were more likely to be found at the ends of plasma DNA molecules. We found that a subset of such preferred ends exhibited selectivity for fetal- or maternal-derived DNA in maternal plasma. The ratio of the number of maternal plasma DNA molecules with fetal preferred ends to those with maternal preferred ends showed a correlation with the fetal DNA fraction. Finally, this second generation approach for noninvasive fetal whole-genome analysis was validated in a pregnancy diagnosed with cardiofaciocutaneous syndrome with maternal plasma DNA sequenced to 195× coverage. The causative de novo BRAF mutation was successfully detected through the maternal plasma DNA analysis.
Subject(s)
DNA/blood , DNA/genetics , Genetic Testing/methods , Pregnancy/blood , Pregnancy/genetics , Prenatal Diagnosis/methods , Computational Biology , DNA Fragmentation , DNA Mutational Analysis , Ectodermal Dysplasia/genetics , Facies , Failure to Thrive/genetics , Female , Fetus , Genome, Human , Heart Defects, Congenital/genetics , High-Throughput Nucleotide Sequencing , Humans , Male , Maternal Inheritance , Paternal Inheritance , Polymorphism, Single Nucleotide , Sequence Analysis, DNA , Whole Genome SequencingABSTRACT
OBJECTIVES: Assessment of post-electroconvulsive therapy (ECT) disorientation at a single time point after ECT treatment may prove an effective and clinically useful method for monitoring the severity of disorientation and predicting ECT-induced retrograde amnesia. In this study, we aimed to validate a novel instrument (10-Item Orientation Questionnaire) developed to assess the level of disorientation after ECT. METHODS: Twenty-four depressed inpatients who were prescribed an acute course of ECT were administered the 10-Item Orientation Questionnaire at 30 minutes after ECT and had time to reorientation assessed at 3 time points after ECT (10, 30, and 60 minutes) at ECT treatments 1 to 3. The association between average performance of the 10-Item Orientation Questionnaire across the acute ECT course and retrograde amnesia at post-ECT was examined using the Autobiographical Memory Interview-Short Form. RESULTS: Mean performance on the 10-Item Orientation Questionnaire across treatments 1 to 3 was moderately correlated with average time to reorientation (r = -0.52, P = 0.02, n = 20). Across the acute ECT course, poorer performance on the 10-Item Orientation Questionnaire was associated with greater retrograde amnesia at post-ECT (r = 0.53, P = 0.03, n = 16). CONCLUSIONS: The 10-Item Orientation Questionnaire when administered at 30 minutes after ECT is sensitive for detecting patients with slow recovery of orientation after ECT. Use of this instrument therefore has potential for improving routine patient monitoring in clinical practice and identifying patients at increased risk of retrograde memory adverse effects following treatment.
Subject(s)
Amnesia, Retrograde/diagnosis , Confusion/diagnosis , Electroconvulsive Therapy/adverse effects , Monitoring, Physiologic/methods , Adult , Aged , Amnesia, Retrograde/etiology , Confusion/etiology , Female , Humans , Male , Mental Disorders/therapy , Middle Aged , Orientation , Reproducibility of Results , Surveys and QuestionnairesABSTRACT
Polarisome is a protein complex that plays an important role in polarized growth in fungi by assembling actin cables towards the site of cell growth. For proper morphogenesis, the polarisome must localize to the right place at the right time. However, the mechanisms that control polarisome localization remain poorly understood. In this study, using the polymorphic fungus Candida albicans as a model, we have discovered that the cyclin-dependent kinase (CDK) Cdc28 phosphorylates the polarisome scaffold protein Spa2 to govern polarisome localization during both yeast and hyphal growth. In a yeast cell cycle, Cdc28-Clb2 phosphorylates Spa2 and controls the timing of polarisome translocation from the bud tip to the bud neck. And during hyphal development, Cdc28-Clb2 and the hyphal-specific Cdc28-Hgc1 cooperate to enhance Spa2 phosphorylation to maintain the polarisome at the hyphal tip. Blocking the CDK phosphorylation causes premature tip-to-neck translocation of Spa2 during yeast growth and inappropriate septal localization of Spa2 in hyphae and abnormal hyphal morphology under certain inducing conditions. Together, our results generate new insights into the mechanisms by which fungi regulate polarisome localization in the control of polarized growth.
Subject(s)
CDC28 Protein Kinase, S cerevisiae/metabolism , Cell Polarity/physiology , Cytoskeletal Proteins/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Candida albicans/growth & development , Candida albicans/metabolism , Cell Cycle/genetics , Cell Polarity/genetics , Fungal Proteins/metabolism , Gene Expression Regulation, Fungal/genetics , Hyphae/growth & development , Hyphae/metabolism , Phosphorylation , Saccharomyces cerevisiae/metabolismABSTRACT
Successful pathogens must be able to swiftly respond to and repair DNA damages inflicted by the host defence. The replication protein A (RPA) complex plays multiple roles in DNA damage response and is regulated by phosphorylation. However, the regulators of RPA phosphorylation remain unclear. Here, we investigated Rfa2 phosphorylation in the pathogenic fungus Candida albicans. Rfa2, a RFA subunit, is phosphorylated when DNA replication is inhibited by hydroxyurea and dephosphorylated during the recovery. By screening a phosphatase mutant library, we found that Pph3 associates with different regulatory subunits to differentially control Rfa2 dephosphorylation in stressed and unstressed cells. Site-directed mutagenesis revealed T11, S18, S29, and S30 being critical for Rfa2 phosphorylation in response to genotoxic insult. We obtained evidence that the genome integrity checkpoint kinase Mec1 and the cyclin-dependent kinase Clb2-Cdc28 mediate Rfa2 phosphorylation. Although cells expressing either a phosphomimetic or a non-phosphorylatable version of Rfa2 had defects, the latter exhibited greater sensitivity to genotoxic challenge, failure to repair DNA damages and to deactivate Rad53-mediated checkpoint pathways in a dosage-dependent manner. These mutants were also less virulent in mice. Our results provide important new insights into the regulatory mechanism and biological significance of Rfa2 phosphorylation in C. albicans.
Subject(s)
Candida albicans/genetics , Candidiasis/microbiology , DNA Damage , DNA-Binding Proteins/metabolism , Fungal Proteins/metabolism , Amino Acid Motifs , Animals , Candida albicans/chemistry , Candida albicans/metabolism , Candida albicans/pathogenicity , DNA Replication , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , Fungal Proteins/chemistry , Fungal Proteins/genetics , Humans , Mice , Mice, Inbred BALB C , Phosphorylation , Replication Protein A/genetics , Replication Protein A/metabolism , VirulenceABSTRACT
Rfa2 is a ssDNA (single-stranded DNA)-binding protein that plays an important role in DNA replication, recombination and repair. Rfa2 is regulated by phosphorylation, which alters its protein-protein interaction and protein-DNA interaction. In the present study, we found that the Pph3-Psy2 phosphatase complex is responsible for Rfa2 dephosphorylation both during normal G1-phase and under DNA replication stress in Candida albicans. Phosphorylated Rfa2 extracted from pph3Δ or psy2Δ G1 cells exhibited diminished binding affinity to dsDNA (double-stranded DNA) but not to ssDNA. We also discovered that Cdc28 (cell division cycle 28) and Mec1 are responsible for Rfa2 phosphorylation in G1-phase and under DNA replication stress respectively. Moreover, MS revealed that the domain of Rfa2 that was phosphorylated in G1-phase differed from that phosphorylated under the stress conditions. The results of the present study imply that differential phosphorylation plays a crucial role in RPA (replication protein A) regulation.
Subject(s)
Candida albicans/metabolism , DNA-Binding Proteins/metabolism , Fungal Proteins/metabolism , Phosphoprotein Phosphatases/metabolism , Amino Acid Sequence , Base Sequence , Candida albicans/cytology , Candida albicans/drug effects , Candida albicans/genetics , DNA Replication , DNA, Fungal/genetics , DNA, Fungal/metabolism , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , Fungal Proteins/chemistry , Fungal Proteins/genetics , G1 Phase , Genes, Fungal , Hydroxyurea/pharmacology , Molecular Sequence Data , Multiprotein Complexes/chemistry , Multiprotein Complexes/metabolism , Phosphoprotein Phosphatases/chemistry , Phosphoprotein Phosphatases/genetics , Phosphorylation , Protein Structure, Tertiary , Replication Protein A/chemistry , Replication Protein A/genetics , Replication Protein A/metabolism , Sequence Homology, Amino Acid , Stress, PhysiologicalABSTRACT
Drug screening based on in-vitro primary tumor cell culture has demonstrated potential in personalized cancer diagnosis. However, the limited number of tumor cells, especially from patients with early stage cancer, has hindered the widespread application of this technique. Hence, we developed a digital microfluidic system for drug screening using primary tumor cells and established a working protocol for precision medicine. Smart control logic was developed to increase the throughput of the system and decrease its footprint to parallelly screen three drugs on a 4 × 4 cm2 chip in a device measuring 23 × 16 × 3.5 cm3. We validated this method in an MDA-MB-231 breast cancer xenograft mouse model and liver cancer specimens from patients, demonstrating tumor suppression in mice/patients treated with drugs that were screened to be effective on individual primary tumor cells. Mice treated with drugs screened on-chip as ineffective exhibited similar results to those in the control groups. The effective drug identified through on-chip screening demonstrated consistency with the absence of mutations in their related genes determined via exome sequencing of individual tumors, further validating this protocol. Therefore, this technique and system may promote advances in precision medicine for cancer treatment and, eventually, for any disease.
Subject(s)
Breast Neoplasms , Microfluidics , Precision Medicine , Xenograft Model Antitumor Assays , Precision Medicine/methods , Humans , Animals , Mice , Female , Cell Line, Tumor , Microfluidics/methods , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Drug Screening Assays, Antitumor/methods , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Lab-On-A-Chip Devices , Microfluidic Analytical Techniques/instrumentation , Microfluidic Analytical Techniques/methodsABSTRACT
Yca1, the only metacaspase in Saccharomyces cerevisiae, is thought to be a clan CD cysteine protease that includes the caspase subfamily. Although yeast is a single cell eukaryote, it can undergo a cell death process reminiscent of apoptosis. Yca1 has been reported to play an important role in the regulation of such apoptotic process. However, the structure and functional mechanism of Yca1 remain largely enigmatic. In this study, we report the crystal structure of the Yca1 metacaspase at 1.7 Å resolution, confirming a caspase-like fold. In sharp contrast to canonical caspases, however, Yca1 exists as a monomer both in solution and in the crystals. Canonical caspase contains six ß-strands, with strand ß6 pairing up with ß6 of another caspase molecule to form a homodimerization interface. In Yca1, an extra pair of antiparallel ß-strands forms a continuous ß-sheet with the six caspase-common ß-strands, blocking potential dimerization. Yca1 was reported to undergo autocatalytic processing in yeast; overexpression in bacteria also led to autoprocessing of Yca1 into two fragments. Unexpectedly, we found that both the autocatalytic processing and the proteolytic activity of Yca1 are greatly facilitated by the presence of calcium (Ca(2+)), but not other divalent cations. Our structural and biochemical characterization identifies Yca1 as a Ca(2+)-activated cysteine protease that may cleave specific substrates during stress response in yeast.
Subject(s)
Calcium/chemistry , Caspases/chemistry , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae/enzymology , Calcium/metabolism , Caspases/genetics , Caspases/metabolism , Catalysis , Crystallography, X-Ray , Protein Structure, Secondary , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Stress, Physiological/physiology , Structure-Activity RelationshipABSTRACT
BACKGROUND: Rates of resistance to macrolide antibiotics in Streptococcus pneumoniae are rising around the world due to the spread of mobile genetic elements harboring mef(E) and erm(B) genes and post-vaccine clonal expansion of strains that carry them. RESULTS: Characterization of 592 clinical isolates collected in Arizona over a 10 year period shows 23.6% are macrolide resistant. The largest portion of the macrolide-resistant population, 52%, is dual mef(E)/erm(B)-positive. All dual-positive isolates are multidrug-resistant clonal lineages of Taiwan19F-14, mostly multilocus sequence type 320, carrying the recently described transposon Tn2010. The remainder of the macrolide resistant S. pneumoniae collection includes 31% mef(E)-positive, and 9% erm(B)-positive strains. CONCLUSIONS: The dual-positive, multidrug-resistant S. pneumoniae clones have likely expanded by switching to non-vaccine serotypes after the heptavalent pneumococcal conjugate vaccine release, and their success limits therapy options. This upsurge could have a considerable clinical impact in Arizona.
Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Macrolides/pharmacology , Pneumococcal Infections/epidemiology , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/drug effects , Adolescent , Adult , Aged , Aged, 80 and over , Arizona/epidemiology , Child , Child, Preschool , Cluster Analysis , DNA Transposable Elements , Female , Genes, Bacterial , Genotype , Humans , Infant , Male , Middle Aged , Molecular Epidemiology , Multilocus Sequence Typing , Pneumococcal Infections/microbiology , Polymerase Chain Reaction , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/isolation & purification , Young AdultABSTRACT
Chimeric antigen receptor T (CAR-T) cells are cytotoxic T cells engineered to specifically kill cancer cells expressing specific target receptor(s). Prior CAR-T efficacy tests include CAR expression analysis by qPCR or ELISA, in vitro measurement of interferon-γ (IFNγ) or interleukin-2 (IL-2), and xenograft models. However, the in vitro measurements did not reflect CAR-T cytotoxicity, whereas xenograft models are low throughput and costly. Here, we presented a robust in vitro droplet microfluidic assay for CAR-T cytotoxicity assessment. This method not only enabled assessment of CAR-T cytotoxic activity under different fluid viscosity conditions, but also facilitated measurement of CAR-T expansion and dissection of mechanism of action via phenotype analysis in vitro. Furthermore, our data suggested that label-free cytotoxicity analysis is feasible by acquiring data before and after treatment. Hence, this study presented a novel in vitro method for assessment of cellular cytotoxicity that could potentially be applied to any cytotoxicity experiment with varying solvent composition.
ABSTRACT
Background: Development of severe immune-related adverse events (irAEs) is a major predicament to stop treatment with immune checkpoint inhibitors, even though tumor progression is suppressed. However, no effective early phase biomarker has been established to predict irAE until now. Method: This study retrospectively used the data of four international, multi-center clinical trials to investigate the application of blood test biomarkers to predict irAEs in atezolizumab-treated advanced non-small cell lung cancer (NSCLC) patients. Seven machine learning methods were exploited to dissect the importance score of 21 blood test biomarkers after 1,000 simulations by the training cohort consisting of 80%, 70%, and 60% of the combined cohort with 1,320 eligible patients. Results: XGBoost and LASSO exhibited the best performance in this study with relatively higher consistency between the training and test cohorts. The best area under the curve (AUC) was obtained by a 10-biomarker panel using the XGBoost method for the 8:2 training:test cohort ratio (training cohort AUC = 0.692, test cohort AUC = 0.681). This panel could be further narrowed down to a three-biomarker panel consisting of C-reactive protein (CRP), platelet-to-lymphocyte ratio (PLR), and thyroid-stimulating hormone (TSH) with a small median AUC difference using the XGBoost method [for the 8:2 training:test cohort ratio, training cohort AUC difference = -0.035 (p < 0.0001), and test cohort AUC difference = 0.001 (p=0.965)]. Conclusion: Blood test biomarkers currently do not have sufficient predictive power to predict irAE development in atezolizumab-treated advanced NSCLC patients. Nevertheless, biomarkers related to adaptive immunity and liver or thyroid dysfunction warrant further investigation.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Immune System Diseases , Lung Neoplasms , Antibodies, Monoclonal, Humanized , Biomarkers , Hematologic Tests , Humans , Lung Neoplasms/diagnosis , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Machine Learning , Retrospective StudiesABSTRACT
PROBLEM: Physicians are playing a growing role as clinician-innovators. Academic physicians are well positioned to contribute to the medical device innovation process, yet few medical school curricula provide students opportunities to learn the conceptual framework for clinical needs finding, needs screening, concept generation and iterative prototyping, and intellectual property management. This framework supports innovation and encourages the development of valuable interdisciplinary communication skills and collaborative learning strategies. APPROACH: Our university offers a novel 3-year-long medical student Longitudinal Interdisciplinary Elective in Biodesign (MSLIEB) that teaches medical device innovation in 4 stages: (1) seminars and small-group work, (2) shared clinical experiences for needs finding, (3) concept generation and product development by serving as consultants for biomedical engineering capstone projects, and (4) reflection and mentorship. The MSLIEB objectives are to: create a longitudinal interdisciplinary peer mentorship relationship between undergraduate biomedical engineering students and medical students, and encourage codevelopment of professional identities in relation to medical device innovation. OUTCOMES: The MSLIEB enrolled 5 entering cohorts from 2017 to 2021 with a total of 37 medical student participants. The first full entering cohort of 12 medical students produced 8 mentored biomedical engineering capstone projects, 7 of which were based on clinical needs statements derived from earlier in the elective. Medical student participants have coauthored poster and oral presentations; contributed to projects that won WolfieTank, a university-wide competition modeled after the television show Shark Tank; and participated in the filing of provisional patents. Students reflecting on the course reported a change in their attitude towards existing medical problems, felt better-equipped to collaboratively design solutions for clinical needs, and considered a potential career path in device design. NEXT STEPS: The MSLIEB will be scaled up by recruiting additional faculty, broadening clinical opportunities to include the outpatient setting, and increasing medical student access to rapid prototyping equipment.
Subject(s)
Education, Medical, Undergraduate , Students, Medical , Curriculum , Humans , Learning , Schools, MedicalABSTRACT
Importance: Blood cell count test (BCT) is a robust method that provides direct quantification of various types of immune cells to reveal the immune landscape to predict atezolizumab treatment outcomes for clinicians to decide the next phase of treatment. Objective: This study aims to define a new BCTscore model to predict atezolizumab treatment benefits in non-small lung cell cancer (NSCLC) patients. Design Setting and Participants: This study analyzed four international, multicenter clinical trials (OAK, BIRCH, POPLAR, and FIR trials) to conduct post-hoc analyses of NSCLC patients undergoing atezolizumab (anti-PD-L1) single-agent treatment (n = 1,479) or docetaxel single-agent treatment (n = 707). BCT was conducted at three time points: pre-treatment (T1), the first day of treatment cycle 3 (T2), and first day of treatment cycle 5 (T3). Univariate and multivariate Cox regression analyses were conducted to identify early BCT biomarkers to predict atezolizumab treatment outcomes in NSCLC patients. Main Outcomes and Measures: Overall survival (OS) was used as the primary end point, whereas progression-free survival (PFS) according to Response Evaluation Criteria in Solid Tumors (RECIST), clinical benefit (CB), and objective response rate (ORR) were used as secondary end points. Results: The BCT biomarkers of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) at time point T3 and neutrophil-to-monocyte ratio (NMR) at time point T2 with absolute cutoff values of NLR_T3 = 5, PLR_T3 = 180, and NMR_T2 = 6 were identified as strong predictive biomarkers for atezolizumab (Ate)-treated NSCLC patients in comparison with docetaxel (Dtx)-treated patients regarding OS (BCTscore low risk: HR Ate vs. Dtx = 1.54 (95% CI: 1.04-2.27), P = 0.031; high risk: HR Ate vs. Dtx = 0.84 (95% CI: 0.62-1.12), P = 0.235). The identified BCTscore model showed better OS AUC in the OAK (AUC12month = 0.696), BIRCH (AUC12month = 0.672) and POPLAR+FIR studies (AUC12month = 0.727) than that of each of the three single BCT biomarkers. Conclusion and Relevance: The BCTscore model is a valid predictive and prognostic biomarker for early survival prediction in atezolizumab-treated NSCLC patients.