24 research outputs found
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European mtDNA Variants Are Associated With Differential Responses to Cisplatin, an Anticancer Drug: Implications for Drug Resistance and Side Effects.
Background: Cisplatin, a powerful antitumor agent, causes formation of DNA adducts, and activation of apoptotic pathways. Presently, cisplatin resistance develops in up to 70% of patients but the underlying molecular mechanism(s) are unclear and there are no markers to determine which patients will become resistant. Mitochondria play a significant role not only in energy metabolism but also retrograde signaling (mitochondria to nucleus) that modulates inflammation, complement, and apoptosis pathways. Maternally inherited mitochondrial (mt) DNA can be classified into haplogroups representing different ethnic populations that have diverse susceptibilities to diseases and medications. Methods: Transmitochondrial cybrids, where all cell lines possess identical nuclear genomes but either the H (Southern European) or J (Northern European) mtDNA haplogroups, were treated with cisplatin and analyzed for differential responses related to viability, oxidative stress, and expression levels of genes associated with cancer, cisplatin-induced nephrotoxicity and resistance, apoptosis and signaling pathways. Results: The cisplatin-treated-J cybrids showed greater loss of cell viability along with lower levels of reactive oxygen species and mitochondrial membrane potential compared to cisplatin-treated-H cybrids. After cisplatin treatment, J cybrids showed increased gene expression of BAX, CASP3, and CYP51A, but lower levels of SFRP1 compared to untreated-J cybrids. The cisplatin-treated-H cybrids had elevated expression of CDKN1A/P21, which has a role in cisplatin toxicity, compared to untreated-H cybrids. The cisplatin-treated H had higher transcription levels of ABCC1, DHRS2/HEP27, and EFEMP1 compared to cisplatin-treated-J cybrids. Conclusions: Cybrid cell lines that contain identical nuclei but either H mtDNA mitochondria or J mtDNA mitochondria respond differently to cisplatin treatments suggesting involvement of the retrograde signaling (from mitochondria to nucleus) in the drug-induced cell death. Varying toxicities and transcription levels of the H vs. J cybrids after cisplatin treatment support the hypothesis that mtDNA variants play a role in the expression of genes affecting resistance and side effects of cisplatin
Hospital trajectories and early predictors of clinical outcomes differ between SARS-CoV-2 and influenza pneumonia
BACKGROUND: A comparison of pneumonias due to SARS-CoV-2 and influenza, in terms of clinical course and predictors of outcomes, might inform prognosis and resource management. We aimed to compare clinical course and outcome predictors in SARS-CoV-2 and influenza pneumonia using multi-state modelling and supervised machine learning on clinical data among hospitalised patients.
METHODS: This multicenter retrospective cohort study of patients hospitalised with SARS-CoV-2 (March-December 2020) or influenza (Jan 2015-March 2020) pneumonia had the composite of hospital mortality and hospice discharge as the primary outcome. Multi-state models compared differences in oxygenation/ventilatory utilisation between pneumonias longitudinally throughout hospitalisation. Differences in predictors of outcome were modelled using supervised machine learning classifiers.
FINDINGS: Among 2,529 hospitalisations with SARS-CoV-2 and 2,256 with influenza pneumonia, the primary outcome occurred in 21% and 9%, respectively. Multi-state models differentiated oxygen requirement progression between viruses, with SARS-CoV-2 manifesting rapidly-escalating early hypoxemia. Highly contributory classifier variables for the primary outcome differed substantially between viruses.
INTERPRETATION: SARS-CoV-2 and influenza pneumonia differ in presentation, hospital course, and outcome predictors. These pathogen-specific differential responses in viral pneumonias suggest distinct management approaches should be investigated.
FUNDING: This project was supported by NIH/NCATS UL1 TR002345, NIH/NCATS KL2 TR002346 (PGL), the Doris Duke Charitable Foundation grant 2015215 (PGL), NIH/NHLBI R35 HL140026 (CSC), and a Big Ideas Award from the BJC HealthCare and Washington University School of Medicine Healthcare Innovation Lab and NIH/NIGMS R35 GM142992 (PS)
Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy
Background
A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets.
Methods
Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis.
Results
A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001).
Conclusion
We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty
Population‐based cohort study of outcomes following cholecystectomy for benign gallbladder diseases
Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‐cause 30‐day readmissions and complications in a prospective population‐based cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‐cause 30‐day readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‐level hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16·3 per cent) were performed as an emergency, 4165 (46·8 per cent) as elective operations, and 3293 patients (37·0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7·1 per cent (633 of 8909) and 10·8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics
European mtDNA Variants Are Associated With Differential Responses to Cisplatin, an Anticancer Drug: Implications for Drug Resistance and Side Effects.
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Ever-increasing diversity of drug-induced pancreatitis.
With over 100000 hospital admissions per annum, acute pancreatitis remains the leading gastrointestinal cause of hospitalization in the United States and has far-reaching impact well beyond. It has become increasingly recognized that drug-induced pancreatitis (DIP), despite accounting for less than 3% of all cases, represents an important and growing though often inconspicuous cause of acute pancreatitis. Nevertheless, knowledge of DIP is often curtailed by the limited availability of evidence needed to implicate given agents, especially for non-prescription medications. Indeed, the majority of available data is derived from case reports, case series, or case control studies. Furthermore, the mechanism of injury and causality for many of these drugs remain elusive as a definitive correlation is generally not established (< 10% of cases). Several classification systems have been proposed, but no single system has been widely adopted, and periodic updates are required in light of ongoing pharmacologic expansion. Moreover, infrequently prescribed medications or those available over-the-counter (including herbal and other alternative remedies) are often overlooked as a potential culprit of acute pancreatitis. Herein, we review the ever-increasing diversity of DIP and the potential mechanisms of injury with the goal of raising awareness regarding the nature and magnitude of this entity. We believe this manuscript will aid in increasing both primary and secondary prevention of DIP, thus ultimately facilitating more expedient diagnosis and a decrease in DIP-related morbidity
Altered Retrograde Signaling Patterns in Breast Cancer Cells Cybrids with H and J Mitochondrial DNA Haplogroups
The aim of this study was to determine the role of retrograde signaling (mitochondria to nucleus) in MCF7 breast cancer cells. Therefore, in the present study, MCF7-H and MCF7-J cybrids were produced using the mitochondria from the same H and J individuals that were already used in our non-diseased retinal pigment epithelium (ARPE19) cybrids. MCF7 cybrids were treated with cisplatin and analyzed for cell viability, mitochondrial membrane potential, ROS, and expression levels of genes associated with the cGAS-STING and cancer-related pathways. Results showed that unlike the ARPE19-H and ARPE19-J cybrids, the untreated MCF7-H and MCF7-J cybrids had similar levels of ATP, lactate, and OCR: ECAR ratios. After cisplatin treatment, MCF7-H and MCF7-J cybrids showed similar (a) decreases in cell viability and ROS levels; (b) upregulation of ABCC1, BRCA1 and CDKN1A/P21; and (c) downregulation of EGFR. Cisplatin-treated ARPE19-H and ARPE19-J cybrids showed increased expression of six cGAS-STING pathway genes, while two were increased for MCF7-J cybrids. In summary, the ARPE19-H and ARPE19-J cybrids behave differentially from each other with or without cisplatin. In contrast, the MCF7-H and MCF7-J cybrids had identical metabolic/bioenergetic profiles and cisplatin responses. Our findings suggest that cancer cell nuclei might have a diminished ability to respond to the modulating signaling of the mtDNA that occurs via the cGAS-STING pathway
Altered Retrograde Signaling Patterns in Breast Cancer Cells Cybrids with H and J Mitochondrial DNA Haplogroups.
The aim of this study was to determine the role of retrograde signaling (mitochondria to nucleus) in MCF7 breast cancer cells. Therefore, in the present study, MCF7-H and MCF7-J cybrids were produced using the mitochondria from the same H and J individuals that were already used in our non-diseased retinal pigment epithelium (ARPE19) cybrids. MCF7 cybrids were treated with cisplatin and analyzed for cell viability, mitochondrial membrane potential, ROS, and expression levels of genes associated with the cGAS-STING and cancer-related pathways. Results showed that unlike the ARPE19-H and ARPE19-J cybrids, the untreated MCF7-H and MCF7-J cybrids had similar levels of ATP, lactate, and OCR: ECAR ratios. After cisplatin treatment, MCF7-H and MCF7-J cybrids showed similar (a) decreases in cell viability and ROS levels; (b) upregulation of ABCC1, BRCA1 and CDKN1A/P21; and (c) downregulation of EGFR. Cisplatin-treated ARPE19-H and ARPE19-J cybrids showed increased expression of six cGAS-STING pathway genes, while two were increased for MCF7-J cybrids. In summary, the ARPE19-H and ARPE19-J cybrids behave differentially from each other with or without cisplatin. In contrast, the MCF7-H and MCF7-J cybrids had identical metabolic/bioenergetic profiles and cisplatin responses. Our findings suggest that cancer cell nuclei might have a diminished ability to respond to the modulating signaling of the mtDNA that occurs via the cGAS-STING pathway
Recommended from our members
European mtDNA Variants Are Associated With Differential Responses to Cisplatin, an Anticancer Drug: Implications for Drug Resistance and Side Effects.
Background: Cisplatin, a powerful antitumor agent, causes formation of DNA adducts, and activation of apoptotic pathways. Presently, cisplatin resistance develops in up to 70% of patients but the underlying molecular mechanism(s) are unclear and there are no markers to determine which patients will become resistant. Mitochondria play a significant role not only in energy metabolism but also retrograde signaling (mitochondria to nucleus) that modulates inflammation, complement, and apoptosis pathways. Maternally inherited mitochondrial (mt) DNA can be classified into haplogroups representing different ethnic populations that have diverse susceptibilities to diseases and medications. Methods: Transmitochondrial cybrids, where all cell lines possess identical nuclear genomes but either the H (Southern European) or J (Northern European) mtDNA haplogroups, were treated with cisplatin and analyzed for differential responses related to viability, oxidative stress, and expression levels of genes associated with cancer, cisplatin-induced nephrotoxicity and resistance, apoptosis and signaling pathways. Results: The cisplatin-treated-J cybrids showed greater loss of cell viability along with lower levels of reactive oxygen species and mitochondrial membrane potential compared to cisplatin-treated-H cybrids. After cisplatin treatment, J cybrids showed increased gene expression of BAX, CASP3, and CYP51A, but lower levels of SFRP1 compared to untreated-J cybrids. The cisplatin-treated-H cybrids had elevated expression of CDKN1A/P21, which has a role in cisplatin toxicity, compared to untreated-H cybrids. The cisplatin-treated H had higher transcription levels of ABCC1, DHRS2/HEP27, and EFEMP1 compared to cisplatin-treated-J cybrids. Conclusions: Cybrid cell lines that contain identical nuclei but either H mtDNA mitochondria or J mtDNA mitochondria respond differently to cisplatin treatments suggesting involvement of the retrograde signaling (from mitochondria to nucleus) in the drug-induced cell death. Varying toxicities and transcription levels of the H vs. J cybrids after cisplatin treatment support the hypothesis that mtDNA variants play a role in the expression of genes affecting resistance and side effects of cisplatin