pti

Tonga volcano eruption disrupted satellites halfway around the world

A link between volcanic activity and rising bubbles of low pressure in the ionosphere has now been proven, which may be why the colossal Tonga volcano eruption in 2022 disrupted satellite communications




pti

Kīlauea volcano: Watch live footage of the eruption in Hawaii

The Kīlauea volcano in Hawaii has begun erupting, spewing volcanic gas and ash across the island




pti

Stunning image of erupting volcano reminds us of Earth’s violent past

This photo of Tungurahua, a volcano exploding in the Ecuadorian night, comes from an illustrated book to accompany a TV series about Earth’s deep history




pti

Iceland volcano: Current cycle of eruptions could last for decades

Iceland is bracing for a volcanic eruption, as thousands of small earthquakes have shaken the southern part of the Reykjanes peninsula since October




pti

Iceland volcano: Watch the Fagradalsfjall eruption live

Iceland’s Fagradalsfjall volcano, located on the country’s south-west Reykjanes peninsula, has erupted after weeks of earthquake activity




pti

Lightning during volcanic eruptions may have sparked life on Earth

Lightning strikes during volcanic eruptions could have provided nitrogen in a form that was needed by early life forms




pti

Largest volcanic eruption in recorded history happened 7300 years ago

The Kikai-Akahoya eruption of an underwater volcano off the coast of Japan ejected enough material to fill Lake Tahoe twice, three times as much as the eruption of Mount Tambora in 1815




pti

Eerie green sunsets after 1883 Krakatoa eruption finally explained

Mysterious green sunsets were reported after the massive eruption of Krakatoa in 1883 – now simulations show how they were created and just how rare they are




pti

Sulphur dioxide from Iceland volcano eruption has reached the UK

A huge plume of sulphur dioxide from the latest eruption in Iceland is drifting across Europe, but it isn't expected to cause any significant harm




pti

Record amount of water from 2022 Tonga eruption is still in atmosphere

Millions of tonnes of water vapour have been lingering in the atmosphere since the Hunga Tonga-Hunga Ha’apai volcano erupted in 2022– possibly contributing to global warming




pti

Next Mauna Loa eruption could be forecast months in advance

An analysis of crystals in lava from the 2022 eruption of Mauna Loa has revealed an unknown magma reservoir within the volcano, which could extend forecasts of eruptions from minutes to months




pti

Ancient Egyptians shaped sheep's horns – and we don't know why

The earliest evidence of livestock with modified horns has been discovered in ancient Egypt – sheep skulls with horns that point in unnatural directions suggest humans forced them to grow that way




pti

Next Mauna Loa eruption could be forecast months in advance

An analysis of crystals in lava from the 2022 eruption of Mauna Loa has revealed an unknown magma reservoir within the volcano, which could extend forecasts of eruptions from minutes to months




pti

Ancient campsite may show how humans survived volcanic super-eruption

Evidence from an archaeological site in Ethiopia suggests ancient humans adapted their diet during a dry spell after the Toba volcano eruption 74,000 years ago




pti

Ancient Egyptian skull shows oldest known attempt at treating cancer

Cut marks on a 4000-year-old skull suggest ancient Egyptian doctors tried to treat a man with nasopharyngeal cancer




pti

Skeletons reveal ancient Egyptian scribes had bad posture at work

The skeletons of ancient Egyptian scribes reveal the health toll of sitting on the floor while performing administrative tasks like writing




pti

Egyptian pyramid may have been built using a water-powered elevator

Ancient Egyptians may have relied on a vertical shaft that could be filled with water, along with a network of water channels and filtration structures, to build the Step Pyramid of Djoser 4500 years ago




pti

Ancient Egyptians shaped sheep's horns – and we don't know why

The earliest evidence of livestock with modified horns has been discovered in ancient Egypt – sheep skulls with horns that point in unnatural directions suggest humans forced them to grow that way




pti

'Extended Cycle' Contraception Garners More Interest

Title: 'Extended Cycle' Contraception Garners More Interest
Category: Health News
Created: 8/25/2008 2:00:00 AM
Last Editorial Review: 8/25/2008 12:00:00 AM




pti

Chronic Drinking Linked to Circadian Disruptions

Title: Chronic Drinking Linked to Circadian Disruptions
Category: Health News
Created: 8/25/2010 12:00:00 AM
Last Editorial Review: 8/26/2010 12:00:00 AM




pti

More Baby Boomers Opting to Cohabit, Not Marry

Title: More Baby Boomers Opting to Cohabit, Not Marry
Category: Health News
Created: 8/31/2012 10:05:00 AM
Last Editorial Review: 8/31/2012 12:00:00 AM




pti

Prescription Sleep Aids a Common Choice for American Insomnia

Title: Prescription Sleep Aids a Common Choice for American Insomnia
Category: Health News
Created: 8/29/2013 9:35:00 AM
Last Editorial Review: 8/29/2013 12:00:00 AM




pti

Light Therapy a Good Option for Pre-Cancerous Skin Lesions, Study Says

Title: Light Therapy a Good Option for Pre-Cancerous Skin Lesions, Study Says
Category: Health News
Created: 8/27/2014 4:35:00 PM
Last Editorial Review: 8/28/2014 12:00:00 AM




pti

Could Oral Contraceptives Help Ease Rheumatoid Arthritis?

Title: Could Oral Contraceptives Help Ease Rheumatoid Arthritis?
Category: Health News
Created: 8/28/2015 12:00:00 AM
Last Editorial Review: 8/28/2015 12:00:00 AM




pti

Season of Conception May Affect Fetal Brain Growth

Title: Season of Conception May Affect Fetal Brain Growth
Category: Health News
Created: 8/24/2016 12:00:00 AM
Last Editorial Review: 8/25/2016 12:00:00 AM




pti

6 in 10 of America's Single Guys 'Take Responsibility' for Contraception

Title: 6 in 10 of America's Single Guys 'Take Responsibility' for Contraception
Category: Health News
Created: 8/31/2017 12:00:00 AM
Last Editorial Review: 8/31/2017 12:00:00 AM




pti

Health Tip: Keep Your Epileptic Child Safer

Title: Health Tip: Keep Your Epileptic Child Safer
Category: Health News
Created: 8/31/2018 12:00:00 AM
Last Editorial Review: 8/31/2018 12:00:00 AM




pti

Brain Implant Puts the Brakes on Epileptic Seizures in Mice

Title: Brain Implant Puts the Brakes on Epileptic Seizures in Mice
Category: Health News
Created: 8/30/2018 12:00:00 AM
Last Editorial Review: 8/31/2018 12:00:00 AM




pti

Staying Optimistic Might Lengthen Your Life, Study Shows

Title: Staying Optimistic Might Lengthen Your Life, Study Shows
Category: Health News
Created: 8/26/2019 12:00:00 AM
Last Editorial Review: 8/27/2019 12:00:00 AM




pti

Survivors' Plasma Still a Solid Option for Treating COVID-19, Experts Say

Title: Survivors' Plasma Still a Solid Option for Treating COVID-19, Experts Say
Category: Health News
Created: 8/26/2020 12:00:00 AM
Last Editorial Review: 8/26/2020 12:00:00 AM




pti

'Vacation PrEP': Short-Term HIV Prevention a Viable Option

Title: 'Vacation PrEP': Short-Term HIV Prevention a Viable Option
Category: Health News
Created: 8/27/2020 12:00:00 AM
Last Editorial Review: 8/28/2020 12:00:00 AM




pti

7 Healthy Sushi Options, Plus Ingredients to Look Out For

Title: 7 Healthy Sushi Options, Plus Ingredients to Look Out For
Category: Health and Living
Created: 8/26/2022 12:00:00 AM
Last Editorial Review: 8/26/2022 12:00:00 AM




pti

7 Scrumptious Drinks That Are High in Iron

Title: 7 Scrumptious Drinks That Are High in Iron
Category: Health and Living
Created: 8/26/2022 12:00:00 AM
Last Editorial Review: 8/26/2022 12:00:00 AM




pti

What Therapeutic Options Are Available for Treating an Antiretroviral Naive Patient?

Title: What Therapeutic Options Are Available for Treating an Antiretroviral Naive Patient?
Category: Diseases and Conditions
Created: 6/16/2022 12:00:00 AM
Last Editorial Review: 6/16/2022 12:00:00 AM




pti

FDA Mulling Over-the-Counter Sale of Contraceptive Pill

Title: FDA Mulling Over-the-Counter Sale of Contraceptive Pill
Category: Health News
Created: 7/11/2022 12:00:00 AM
Last Editorial Review: 7/11/2022 12:00:00 AM




pti

Treating central sleep apnoea in heart failure: is positive airway pressure and adaptive servo-ventilation in particular the gold standard?

Extract

We read with great interest the review article by Randerath et al. [1] recently published in the European Respiratory Review. We would like to congratulate the authors on this clearly structured review, which emphasises the urgent need for an increasingly differentiated view of central sleep apnoea (CSA) in the context of precision medicine.




pti

Mutational scanning of CRX classifies clinical variants and reveals biochemical properties of the transcriptional effector domain [RESEARCH]

The transcription factor (TF) cone-rod homeobox (CRX) is essential for the differentiation and maintenance of photoreceptor cell identity. Several human CRX variants cause degenerative retinopathies, but most are variants of uncertain significance. We performed a deep mutational scan (DMS) of nearly all possible single amino acid substitutions in CRX using a cell-based transcriptional reporter assay, curating a high-confidence list of nearly 2000 variants with altered transcriptional activity. In the structured homeodomain, activity scores closely aligned to a predicted structure and demonstrated position-specific constraints on amino acid substitution. In contrast, the intrinsically disordered transcriptional effector domain displayed a qualitatively different pattern of substitution effects, following compositional constraints without specific residue position requirements in the peptide chain. These compositional constraints were consistent with the acidic exposure model of transcriptional activation. We evaluated the performance of the DMS assay as a clinical variant classification tool using gold-standard classified human variants from ClinVar, identifying pathogenic variants with high specificity and moderate sensitivity. That this performance could be achieved using a synthetic reporter assay in a foreign cell type, even for a highly cell type-specific TF like CRX, suggests that this approach shows promise for DMS of other TFs that function in cell types that are not easily accessible. Together, the results of the CRX DMS identify molecular features of the CRX effector domain and demonstrate utility for integration into the clinical variant classification pipeline.




pti

Headache Treatment Options

Family medicine physicians often see headache as the chief complaint when meeting patients within their practice. The goal is to try different treatment modalities without having to send the patient to a specialist. Headaches affect different individuals during their lifetime. Before any treatment begins, it is best that one rules out possible causes of the headache, for example, drug interactions or structural cerebrum conditions. Nonpharmacological treatment is recommended first before attempting a stepwise approach to cost-effective pharmacological treatment options. Pharmacological treatment options should include preventive and on-demand options. A family physician has all the resources to assist patients with different types of headaches.




pti

Effects of Lung Injury and Abdominal Insufflation on Respiratory Mechanics and Lung Volume During Time-Controlled Adaptive Ventilation

BACKGROUD:Lung volume measurements are important for monitoring functional aeration and recruitment and may help guide adjustments in ventilator settings. The expiratory phase of airway pressure release ventilation (APRV) may provide physiologic information about lung volume based on the expiratory flow-time slope, angle, and time to approach a no-flow state (expiratory time [TE]). We hypothesized that expiratory flow would correlate with estimated lung volume (ELV) as measured using a modified nitrogen washout/washin technique in a large-animal lung injury model.METHODS:Eight pigs (35.2 ± 1.0 kg) were mechanically ventilated using an Engström Carescape R860 on the APRV mode. All settings were held constant except the expiratory duration, which was adjusted based on the expiratory flow curve. Abdominal pressure was increased to 15 mm Hg in normal and injured lungs to replicate a combination of pulmonary and extrapulmonary lung injury. ELV was estimated using the Carescape FRC INview tool. The expiratory flow-time slope and TE were measured from the expiratory flow profile.RESULTS:Lung elastance increased with induced lung injury from 29.3 ± 7.3 cm H2O/L to 39.9 ± 15.1cm H2O/L, and chest wall elastance increased with increasing intra-abdominal pressures (IAPs) from 15.3 ± 4.1 cm H2O/L to 25.7 ± 10.0 cm H2O/L in the normal lung and 15.8 ± 6.0 cm H2O/L to 33.0 ± 6.2 cm H2O/L in the injured lung (P = .39). ELV decreased from 1.90 ± 0.83 L in the injured lung to 0.67 ± 0.10 L by increasing IAP to 15 mm Hg. This had a significant correlation with a TE decrease from 2.3 ± 0.8 s to 1.0 ± 0.1 s in the injured group with increasing insufflation pressures (ρ = 0.95) and with the expiratory flow-time slope, which increased from 0.29 ± 0.06 L/s2 to 0.63 ± 0.05 L/s2 (ρ = 0.78).CONCLUSIONS:Changes in ELV over time, and the TE and flow-time slope, could be used to demonstrate evolving lung injury during APRV. Using the slope to infer changes in functional lung volume represents a unique, reproducible, real-time, bedside technique that does not interrupt ventilation and may be used for clinical interpretation.




pti

The Impact of Opioid Prescription on the Occurrence and Outcome of Pneumonia: A Nationwide Cohort Study in South Korea

BACKGROUND:Opioids are known to cause respiratory depression, aspiration, and to suppress the immune system. This study aimed to investigate the relationship between short- and long-term opioid use and the occurrence and clinical outcomes of pneumonia in South Korea.METHODS:The data for this population-based retrospective cohort analysis were obtained from the South Korean National Health Insurance Service. The opioid user group consisted of those prescribed opioids in 2016, while the non-user group, who did not receive opioid prescriptions that year, was selected using a 1:1 stratified random sampling method. The opioid users were categorized into short-term (1–89 d) and long-term (≥90 d) users. The primary end point was pneumonia incidence from January 1, 2017–December 31, 2021, with secondary end points including pneumonia-related hospitalizations and mortality rates during the study period.RESULTS:In total, 4,556,606 adults were enrolled (opioid group, 2,070,039). Opioid users had a 3% higher risk of pneumonia and an 11% higher risk of pneumonia requiring hospitalization compared to non-users. Short-term users had a 3% higher risk of pneumonia, and long-term users had a 4% higher risk compared to non-users (P < .001). Additionally, short-term users had an 8% higher risk of hospital-treated pneumonia, and long-term users had a 17% higher risk compared to non-users (P < .001).CONCLUSIONS:Both short- and long-term opioid prescriptions were associated with higher incidences of pneumonia and hospital-treated pneumonia. In addition, long-term opioid prescriptions were linked to higher mortality rates due to pneumonia.




pti

Fundamentals of Descriptive Statistics

Descriptive statistics (DS) play a crucial role in establishing a solid foundation for study analysis and are important for understanding the results of a study or data set. If the data from DS is used incorrectly, the study may be misinterpreted. Descriptive statistics summarizes and organizes data, making analysis easier and providing an overview of the characteristics of sampled data. This analysis is comprised of measures of central tendency, which includes the mean, median, and mode of a particular data set. Understanding how to use each metric is essential for basic statistical analysis. The purpose of this short report is to review descriptive statistics and describe how to best utilize them during data analysis. The authors aim to provide this short report as an educational resource to assist the dental hygiene research community in understanding statistical analysis through descriptive statistics.




pti

Intraprofessional Education Experiences in Dentistry: Dental hygienists&#x2019; perceptions of collaboration with dentists

Purpose Health care professionals (HCPs) working collaboratively can improve patient outcomes and also increase their understanding of each other’s professional roles. This descriptive study aimed to explore dental hygienists’ perceptions of collaboration with dentists and intraprofessional educational (IntraPE) experiences.Methods A convenience sampling method was used to assess DHs perceptions of collaboration with dentists using the Interprofessional Collaboration Scale (ICS), a validated scale that measures perceptions of communication, accommodation, and isolation among HCPs. One open-ended question was added to explore IntraPE. Demographics, work characteristics and responses from the ICS were analyzed using frequency, mean, standard deviation, Pearson’s correlation, t-test, ANOVA, and multivariable regression. Responses from the open-ended question were transcribed, organized, and coded. Themes were identified using the Delve Qualitative Analysis Tool.Results Of the 264 participants, the average age was 38.9, and most identified as female (98.9%). Data analysis revealed that DHs had positive perceptions of collaboration with dentists. Significant relationships were found between ICS factor accommodation and the average number of patients treated per day (rs = −0.242, p<0.001), dentists’ age (rs = −.145, p<0.05). Isolation showed a significant negative correlation with the average number of patients treated per day (rs = −0.156, p<0.05). Most reported having no opportunities for IntraPE education experiences with dentists. Five categories of themes were identified from the open-ended question: shared academic setting, clinic dentist, externships, desire for more shared learning, and shared patient experiences.Conclusion Dental hygienists in this study had an overall more positive than negative perception of collaboration with dentists. Dental and dental hygiene programs should focus on intraprofessional education experiences to continue to enhance collaboration.




pti

Interoceptive inference and prediction in food-related disorders [Special Section: Symposium Outlook]

The brain's capacity to predict and anticipate changes in internal and external environments is fundamental to initiating efficient adaptive responses, behaviors, and reflexes that minimize disruptions to physiology. In the context of feeding control, the brain predicts and anticipates responses to the consumption of dietary substances, thus driving adaptive behaviors in the form of food choices, physiological preparation for meals, and engagement of defensive mechanisms. Here, we provide an integrative perspective on the multisensory computation between exteroceptive and interoceptive cues that guides feeding strategy and may result in food-related disorders.




pti

Decoding genetic susceptibility to Pseudomonas aeruginosa infections in cystic fibrosis

Extract

In cystic fibrosis (CF), Pseudomonas aeruginosa acquisition represents a turning point in disease progression. The presence of chronic P. aeruginosa infection is associated with worsening lung function and increased risk of earlier death, whereas treatment substantially improves lung function and survival [1, 2]. Efforts to diagnose and eradicate early P. aeruginosa provide lasting benefits for children with CF [3, 4]. However, the timing of infection varies considerably between individuals with CF, treatment centres [5, 6], and different birth cohorts of people with the disease [7, 8].




pti

Genome-wide association study of susceptibility to Pseudomonas aeruginosa infection in cystic fibrosis

Background

Pseudomonas aeruginosa is a common pathogen that contributes to progressive lung disease in cystic fibrosis (CF). Genetic factors other than CF-causing CFTR (CF transmembrane conductance regulator) variations contribute ~85% of the variation in chronic P. aeruginosa infection age in CF according to twin studies, but the susceptibility loci remain unknown. Our objective is to advance understanding of the genetic basis of host susceptibility to P. aeruginosa infection.

Materials and methods

We conducted a genome-wide association study of chronic P. aeruginosa infection age in 1037 Canadians with CF. We subsequently assessed the genetic correlation between chronic P. aeruginosa infection age and lung function through polygenic risk score (PRS) analysis and inferred their causal relationship through bidirectional Mendelian randomisation analysis.

Results

Two novel genome-wide significant loci with lead single nucleotide polymorphisms (SNPs) rs62369766 (chr5p12; p=1.98x10–8) and rs927553 (chr13q12.12; p=1.91x10–8) were associated with chronic P. aeruginosa infection age. The rs62369766 locus was validated using an independent French cohort (n=501). Furthermore, the PRS constructed from CF lung function-associated SNPs was significantly associated with chronic P. aeruginosa infection age (p=0.002). Finally, our analysis presented evidence for a causal effect of lung function on chronic P. aeruginosa infection age (β=0.782 years, p=4.24x10–4). In the reverse direction, we observed a moderate effect (β=0.002, p=0.012).

Conclusions

We identified two novel loci that are associated with chronic P. aeruginosa infection age in individuals with CF. Additionally, we provided evidence of common genetic contributors and a potential causal relationship between P. aeruginosa infection susceptibility and lung function in CF. Therapeutics targeting these genetic factors may delay the onset of chronic infections, which account for significant remaining morbidity in CF.




pti

Characterization and Prediction of Organic Anion Transporting Polypeptide 1B Activity in Prostate Cancer Patients on Abiraterone Acetate Using Endogenous Biomarker Coproporphyrin I [Articles]

Organic anion transporting polypeptide (OATP) 1B1 and OATP1B3 are important hepatic transporters. We previously identified OATP1B3 being critically implicated in the disposition of abiraterone. We aimed to further investigate the effects of abiraterone on the activities of OATP1B1 and OATP1B3 utilizing a validated endogenous biomarker coproporphyrin I (CP-I). We used OATP1B-transfected cells to characterize the inhibitory potential of abiraterone against OATP1B-mediated uptake of CP-I. Inhibition constant (Ki) was incorporated into our physiologically based pharmacokinetic (PBPK) modeling to simulate the systemic exposures of CP-I among cancer populations receiving either our model-informed 500 mg or clinically approved 1000 mg abiraterone acetate (AA) dosage. Simulated data were compared with clinical CP-I concentrations determined among our nine metastatic prostate cancer patients receiving 500 mg AA treatment. Abiraterone inhibited OATP1B3-mediated, but not OATP1B1-mediated, uptake of CP-I in vitro, with an estimated Ki of 3.93 μM. Baseline CP-I concentrations were simulated to be 0.81 ± 0.26 ng/ml and determined to be 0.72 ± 0.16 ng/ml among metastatic prostate cancer patients, both of which were higher than those observed for healthy subjects. PBPK simulations revealed an absence of OATP1B3-mediated interaction between abiraterone and CP-I. Our clinical observations confirmed that CP-I concentrations remained comparable to baseline levels up to 12 weeks post 500 mg AA treatment. Using CP-I as an endogenous biomarker, we identified the inhibition of abiraterone on OATP1B3 but not OATP1B1 in vitro, which was predicted and observed to be clinically insignificant. We concluded that the interaction risk between AA and substrates of OATP1Bs is low.

SIGNIFICANCE STATEMENT

The authors used the endogenous biomarker coproporphyrin I (CP-I) and identified abiraterone as a moderate inhibitor of organic anion transporting polypeptide (OATP) 1B3 in vitro. Subsequent physiologically based pharmacokinetic (PBPK) simulations and clinical observations suggested an absence of OATP1B-mediated interaction between abiraterone and CP-I among prostate cancer patients. This multipronged study concluded that the interaction risk between abiraterone acetate and substrates of OATP1Bs is low, demonstrating the application of PBPK-CP-I modeling in predicting OATP1B-mediated interaction implicating abiraterone.




pti

Molecular Mechanisms for the Selective Transport of Dichlorofluorescein by Human Organic Anion Transporting Polypeptide 1B1 [Articles]

Human organic anion transporting polypeptide (OATP) 1B1 and 1B3 are two highly homologous liver-specific uptake transporters. However, 2’,7’-dichlorofluorescein (DCF) is preferably transported by OATP1B1. In the present study, the molecular mechanisms for the selective transport of DCF by OATP1B1 were investigated by constructing and characterizing an array of OATP1B1/1B3 chimeras and site-directed mutagenesis. Our results show that transmembrane domain (TM) 10 is crucial for the surface expression and function of OATP1B1, in which Q541 and L545 play the most important roles in DCF transport. Replacement of TM10 in OATP1B1 with its OATP1B3 counterpart led to OATP1B1’s complete intracellular retention. Q541 and L545 may interact with DCF directly via hydrogen bonding and hydrophobic interactions. The decrease of DCF uptake by Q541A and L545S was due to their reduced binding affinity for DCF as compared with OATP1B1. In addition, Q541 and L545 are also crucial for the transport of estradiol-17β-glucuronide (E17βG) but not for the transport of estrone-3-sulfate (E3S), indicating different interaction modes between DCF/E17βG and E3S in OATP1B1. Taken together, Q541 and L545 in TM10 are critical for OATP1B1-mediated DCF uptake, but their effect is substrate-dependent.

SIGNIFICANCE STATEMENT

The key TMs and amino acid residues for the selective transport of DCF by OATP1B1 were identified. TM10 is crucial for the surface expression and function of OATP1B1. Within TM10, Q541 and L545 played the most significant roles and affected the function of OATP1B1 in a substrate-dependent manner. This information is crucial for a better understanding of the mechanism of the multispecificity of OATP1B1 and as a consequence the mechanism of OATP1B1-mediated drug–drug interactions.




pti

The Induction of Drug Uptake Transporter Organic Anion Transporting Polypeptide 1A2 by Radiation Is Mediated by the Nonreceptor Tyrosine Kinase v-YES-1 Yamaguchi Sarcoma Viral Oncogene Homolog 1 [Articles]

Organic anion transporting polypeptides (OATP, gene symbol SLCO) are well-recognized key determinants for the absorption, distribution, and excretion of a wide spectrum of endogenous and exogenous compounds including many antineoplastic agents. It was therefore proposed as a potential drug target for cancer therapy. In our previous study, it was found that low-dose X-ray and carbon ion irradiation both upregulated the expression of OATP family member OATP1A2 and in turn, led to a more dramatic killing effect when cancer cells were cotreated with antitumor drugs such as methotrexate. In the present study, the underlying mechanism of the phenomenon was explored in breast cancer cell line MCF-7. It was found that the nonreceptor tyrosine kinase v-YES-1 Yamaguchi sarcoma viral oncogene homolog 1 (YES-1) was temporally coordinated with the change of OATP1A2 after irradiation. The overexpression of YES-1 significantly increased OATP1A2 both at the mRNA and protein level. The signal transducer and activator of transcription 3 (STAT3) pathway is likely the downstream target of YES-1 because phosphorylation and nuclear accumulation of STAT3 were both enhanced after overexpressing YES-1 in MCF-7 cells. Further investigation revealed that there are two possible binding sites of STAT3 localized at the upstream sequence of SLCO1A2, the encoding gene of OATP1A2. Electrophoretic mobility shift assay and chromatin immunoprecipitation analysis suggested that these two sites bound to STAT3 specifically and the overexpression of YES-1 significantly increased the association of the transcription factor with the putative binding sites. Finally, inhibition or knockdown of YES-1 attenuated the induction effect of radiation on the expression of OATP1A2.

SIGNIFICANCE STATEMENT

The present study found that the effect of X-rays on v-YES-1 Yamaguchi sarcoma viral oncogene homolog 1 (YES-1) and organic anion transporting polypeptides (OATP)1A2 was temporally coordinated. YES-1 phosphorylates and increases the nuclear accumulation of signal transducer and activator of transcription 3, which in turn binds to the upstream regulatory sequences of SLCO1A2, the coding gene for OATP1A2. Hence, inhibitors of YES-1 may suppress the radiation induction effect on OATP1A2.




pti

Characterizing the Distribution of a Stimulator of Interferon Genes Agonist and Its Metabolites in Mouse Liver by Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry [Special Section on New and Emerging Areas and Technologies in Drug Met

A STING (stimulator of interferon genes) agonist GSK3996915 under investigation in early discovery for hepatitis B was orally dosed to a mouse model for understanding the parent drug distribution in liver, the target organ. Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) was used to quantify the distribution of GSK3996915 in liver collected from mice administered a single oral dose at 90 mg/kg. GSK3996915 was detected with a zonal distribution localized in the portal triad and highly concentrated in the main bile ducts, indicating clearance through biliary excretion. High spatial resolution imaging showed the distribution of the parent drug localized to the cellular populations in the sinusoids, including the Kupffer cells. Additionally, a series of drug-related metabolites were observed to be localized in the central zones of the liver. These results exemplify the potential of utilizing MALDI IMS for measuring not only quantitative drug distribution and target exposure but also drug metabolism and elimination in a single suite of experiments.

SIGNIFICANCE STATEMENT

An integrated imaging approach utilizing matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) complemented with immunohistochemistry (IHC) and histology was used to address the question of target exposure at the cellular level. Localized quantification of the parent drug in the target organ and identification of potential metabolites in the context of tissue histology were also achieved in one experimental suite to support characterization of pharmacokinetic properties of the drug in the early discovery stage.:




pti

Evaluating Drug-Drug Interaction Risk Associated with Peptide Analogs Using advanced In Vitro Systems [Special Section on New and Emerging Areas and Technologies in Drug Metabolism and Disposition, Part II]

Drug–drug interaction (DDI) assessment of therapeutic peptides is an evolving area. The industry generally follows DDI guidelines for small molecules, but the translation of data generated with commonly used in vitro systems to in vivo is sparse. In the current study, we investigated the ability of advanced human hepatocyte in vitro systems, namely HepatoPac, spheroids, and Liver-on-a-chip, to assess potential changes in regulation of CYP1A2, CYP2B6, CYP3A4, SLCO1B1, and ABCC2 in the presence of selected therapeutic peptides, proteins, and small molecules. The peptide NN1177, a glucagon and GLP-1 receptor co-agonist, did not suppress mRNA expression or activity of CYP1A2, CYP2B6, and CYP3A4 in HepatoPac, spheroids, or Liver-on-a-chip; these findings were in contrast to the data obtained in sandwich cultured hepatocytes. No effect of NN1177 on SLCO1B1 and ABCC2 mRNA was observed in any of the complex systems. The induction magnitude differed across the systems (e.g., rifampicin induction of CYP3A4 mRNA ranged from 2.8-fold in spheroids to 81.2-fold in Liver-on-a-chip). Small molecules, obeticholic acid and abemaciclib, showed varying responses in HepatoPac, spheroids, and Liver-on-a-chip, indicating a need for EC50 determinations to fully assess translatability data. HepatoPac, the most extensively investigated in this study (3 donors), showed high potential to investigate DDIs associated with CYP regulation by therapeutic peptides. Spheroids and Liver-on-a-chip were only assessed in one hepatocyte donor and further evaluations are required to confirm their potential. This study establishes an excellent foundation toward the establishment of more clinically-relevant in vitro tools for evaluation of potential DDIs with therapeutic peptides.

SIGNIFICANT STATEMENT

At present, there are no guidelines for drug–drug interaction (DDI) assessment of therapeutic peptides. Existing in vitro methods recommended for assessing small molecule DDIs do not appear to translate well for peptide drugs, complicating drug development for these moieties. Here, we establish evidence that complex cellular systems have potential to be used as more clinically-relevant tools for the in vitro DDI evaluation of therapeutic peptides.