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Afinitor Disperz Approved for Rare Pediatric Cancer

Title: Afinitor Disperz Approved for Rare Pediatric Cancer
Category: Health News
Created: 8/29/2012 6:05:00 PM
Last Editorial Review: 8/30/2012 12:00:00 AM




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Health Tip: Triggers for Hiatal Hernia

Title: Health Tip: Triggers for Hiatal Hernia
Category: Health News
Created: 8/26/2013 7:35:00 AM
Last Editorial Review: 8/26/2013 12:00:00 AM




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Good Nutrition Can Boost School Performance, Expert Says

Title: Good Nutrition Can Boost School Performance, Expert Says
Category: Health News
Created: 8/25/2013 9:35:00 AM
Last Editorial Review: 8/26/2013 12:00:00 AM




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Start School Later for Older Kids, Pediatricians Urge

Title: Start School Later for Older Kids, Pediatricians Urge
Category: Health News
Created: 8/25/2014 9:35:00 AM
Last Editorial Review: 8/25/2014 12:00:00 AM




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Pediatricians Offer New Dental Recommendations

Title: Pediatricians Offer New Dental Recommendations
Category: Health News
Created: 8/25/2014 9:35:00 AM
Last Editorial Review: 8/25/2014 12:00:00 AM




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Number of Young Non-Smokers Who Tried E-Cigs Tripled in 2 Years

Title: Number of Young Non-Smokers Who Tried E-Cigs Tripled in 2 Years
Category: Health News
Created: 8/25/2014 2:36:00 PM
Last Editorial Review: 8/26/2014 12:00:00 AM




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Electrical Pulses to Scalp May Boost Memory: Study

Title: Electrical Pulses to Scalp May Boost Memory: Study
Category: Health News
Created: 8/28/2014 2:36:00 PM
Last Editorial Review: 8/29/2014 12:00:00 AM




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Hep B Vaccine Should Be Given Sooner: Pediatricians Group

Title: Hep B Vaccine Should Be Given Sooner: Pediatricians Group
Category: Health News
Created: 8/28/2017 12:00:00 AM
Last Editorial Review: 8/28/2017 12:00:00 AM




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Pediatric Treatment Approved for 'Kissing Bug' Disease

Title: Pediatric Treatment Approved for 'Kissing Bug' Disease
Category: Health News
Created: 8/30/2017 12:00:00 AM
Last Editorial Review: 8/31/2017 12:00:00 AM




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Pediatricians Sound Alarm on Rapid Weight Changes in Young Athletes

Title: Pediatricians Sound Alarm on Rapid Weight Changes in Young Athletes
Category: Health News
Created: 9/1/2017 12:00:00 AM
Last Editorial Review: 9/1/2017 12:00:00 AM




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Arkansas Law Restricting Abortion Pills Remains on Hold

Title: Arkansas Law Restricting Abortion Pills Remains on Hold
Category: Health News
Created: 8/24/2018 12:00:00 AM
Last Editorial Review: 8/27/2018 12:00:00 AM




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Expert Advice for a Safe Trip Back to School

Title: Expert Advice for a Safe Trip Back to School
Category: Health News
Created: 8/27/2018 12:00:00 AM
Last Editorial Review: 8/28/2018 12:00:00 AM




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Is Climate Change Draining Nutrients From Crops?

Title: Is Climate Change Draining Nutrients From Crops?
Category: Health News
Created: 8/27/2018 12:00:00 AM
Last Editorial Review: 8/28/2018 12:00:00 AM




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Pediatricians Make Change to Child Car Seat Guidelines

Title: Pediatricians Make Change to Child Car Seat Guidelines
Category: Health News
Created: 8/30/2018 12:00:00 AM
Last Editorial Review: 8/30/2018 12:00:00 AM




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Monkey Trials Raise Hope for Non-Addictive Opioid Alternative

Title: Monkey Trials Raise Hope for Non-Addictive Opioid Alternative
Category: Health News
Created: 8/30/2018 12:00:00 AM
Last Editorial Review: 8/31/2018 12:00:00 AM




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Men Should be Included in Breast Cancer Clinical Trials: FDA

Title: Men Should be Included in Breast Cancer Clinical Trials: FDA
Category: Health News
Created: 8/26/2019 12:00:00 AM
Last Editorial Review: 8/27/2019 12:00:00 AM




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Vaping May Trigger Lung Damage Like That Seen in Emphysema

Title: Vaping May Trigger Lung Damage Like That Seen in Emphysema
Category: Health News
Created: 8/26/2019 12:00:00 AM
Last Editorial Review: 8/27/2019 12:00:00 AM




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Rising Obesity Rates Undermining Strides Made Against Heart Disease

Title: Rising Obesity Rates Undermining Strides Made Against Heart Disease
Category: Health News
Created: 8/27/2019 12:00:00 AM
Last Editorial Review: 8/28/2019 12:00:00 AM




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Coronavirus' Weird Trip Inside Cells Might Be Its Undoing, Scientists Say

Title: Coronavirus' Weird Trip Inside Cells Might Be Its Undoing, Scientists Say
Category: Health News
Created: 8/24/2020 12:00:00 AM
Last Editorial Review: 8/24/2020 12:00:00 AM




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Just Like COVID, Severe Flu Can Trigger Heart Crises

Title: Just Like COVID, Severe Flu Can Trigger Heart Crises
Category: Health News
Created: 8/25/2020 12:00:00 AM
Last Editorial Review: 8/25/2020 12:00:00 AM




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Making a COVID-19 Vaccine Is Tough, Distributing It Might Be Tougher

Title: Making a COVID-19 Vaccine Is Tough, Distributing It Might Be Tougher
Category: Health News
Created: 8/25/2020 12:00:00 AM
Last Editorial Review: 8/25/2020 12:00:00 AM




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How to Keep Your Kids Trim Through Quarantine

Title: How to Keep Your Kids Trim Through Quarantine
Category: Health News
Created: 8/25/2020 12:00:00 AM
Last Editorial Review: 8/26/2020 12:00:00 AM




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Changes to CDC's COVID-19 Testing Guidelines Trigger Concern

Title: Changes to CDC's COVID-19 Testing Guidelines Trigger Concern
Category: Health News
Created: 8/26/2020 12:00:00 AM
Last Editorial Review: 8/27/2020 12:00:00 AM




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Tasty, Nutritious School Lunches for Your Budget

Title: Tasty, Nutritious School Lunches for Your Budget
Category: Health News
Created: 8/21/2022 12:00:00 AM
Last Editorial Review: 8/22/2022 12:00:00 AM




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Too Few Psychiatric Beds: Psychiatrists' Group Takes Aim at Ongoing Crisis

Title: Too Few Psychiatric Beds: Psychiatrists' Group Takes Aim at Ongoing Crisis
Category: Health News
Created: 8/17/2022 12:00:00 AM
Last Editorial Review: 8/18/2022 12:00:00 AM




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More Athletes Are Getting Their Nutrition Through an IV. This Should Stop, Experts Say

Title: More Athletes Are Getting Their Nutrition Through an IV. This Should Stop, Experts Say
Category: Health News
Created: 8/17/2022 12:00:00 AM
Last Editorial Review: 8/18/2022 12:00:00 AM




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Lamisil (terbinafine) vs. Lotrimin (clotrimazole)

Title: Lamisil (terbinafine) vs. Lotrimin (clotrimazole)
Category: Medications
Created: 6/10/2019 12:00:00 AM
Last Editorial Review: 8/10/2022 12:00:00 AM




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Ketoconazole cream vs. clotrimazole cream

Title: Ketoconazole cream vs. clotrimazole cream
Category: Medications
Created: 5/29/2019 12:00:00 AM
Last Editorial Review: 8/25/2022 12:00:00 AM




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Who Fares Worse After Multiple Sclerosis Strikes?

Title: Who Fares Worse After Multiple Sclerosis Strikes?
Category: Health News
Created: 8/11/2022 12:00:00 AM
Last Editorial Review: 8/12/2022 12:00:00 AM




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There's More MS in Northern Countries. Now, Researchers Find New Reason Why

Title: There's More MS in Northern Countries. Now, Researchers Find New Reason Why
Category: Health News
Created: 8/25/2022 12:00:00 AM
Last Editorial Review: 8/25/2022 12:00:00 AM




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New Multiple Sclerosis Treatment Shows Promise in Trial

Title: New Multiple Sclerosis Treatment Shows Promise in Trial
Category: Health News
Created: 8/25/2022 12:00:00 AM
Last Editorial Review: 8/26/2022 12:00:00 AM




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Theoretical framework for the difference of two negative binomial distributions and its application in comparative analysis of sequencing data [METHODS]

High-throughput sequencing (HTS) technologies have been instrumental in investigating biological questions at the bulk and single-cell levels. Comparative analysis of two HTS data sets often relies on testing the statistical significance for the difference of two negative binomial distributions (DOTNB). Although negative binomial distributions are well studied, the theoretical results for DOTNB remain largely unexplored. Here, we derive basic analytical results for DOTNB and examine its asymptotic properties. As a state-of-the-art application of DOTNB, we introduce DEGage, a computational method for detecting differentially expressed genes (DEGs) in scRNA-seq data. DEGage calculates the mean of the sample-wise differences of gene expression levels as the test statistic and determines significant differential expression by computing the P-value with DOTNB. Extensive validation using simulated and real scRNA-seq data sets demonstrates that DEGage outperforms five popular DEG analysis tools: DEGseq2, DEsingle, edgeR, Monocle3, and scDD. DEGage is robust against high dropout levels and exhibits superior sensitivity when applied to balanced and imbalanced data sets, even with small sample sizes. We utilize DEGage to analyze prostate cancer scRNA-seq data sets and identify marker genes for 17 cell types. Furthermore, we apply DEGage to scRNA-seq data sets of mouse neurons with and without fear memory and reveal eight potential memory-related genes overlooked in previous analyses. The theoretical results and supporting software for DOTNB can be widely applied to comparative analyses of dispersed count data in HTS and broad research questions.




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The Impact of Increased PEEP on Hemodynamics, Respiratory Mechanics, and Oxygenation in Pediatric ARDS

BACKGROUND:PEEP is a cornerstone treatment for children with pediatric ARDS. Unfortunately, its titration is often performed solely by evaluating oxygen saturation, which can lead to inadequate PEEP level settings and consequent adverse effects. This study aimed to assess the impact of increasing PEEP on hemodynamics, respiratory system mechanics, and oxygenation in children with ARDS.METHODS:Children receiving mechanical ventilation and on pressure-controlled volume-guaranteed mode were prospectively assessed for inclusion. PEEP was sequentially changed to 5, 12, 10, 8 cm H2O, and again to 5 cm H2O. After 10 min at each PEEP level, hemodynamic, ventilatory, and oxygenation variables were collected.RESULTS:A total of 31 subjects were included, with median age and weight of 6 months and 6.3 kg, respectively. The main reasons for pediatric ICU admission were respiratory failure caused by acute viral bronchiolitis (45%) and community-acquired pneumonia (32%). Most subjects had mild or moderate ARDS (45% and 42%, respectively), with a median (interquartile range) oxygenation index of 8.4 (5.8–12.7). Oxygen saturation improved significantly when PEEP was increased. However, although no significant changes in blood pressure were observed, the median cardiac index at PEEP of 12 cm H2O was significantly lower than that observed at any other PEEP level (P = .001). Fourteen participants (45%) experienced a reduction in cardiac index of > 10% when PEEP was increased to 12 cm H2O. Also, the estimated oxygen delivery was significantly lower, at 12 cm H2O PEEP. Finally, respiratory system compliance significantly reduced when PEEP was increased. At a PEEP of 12 cm H2O, static compliance had a median reduction of 25% in relation to the initial assessment (PEEP of 5 cm H2O).CONCLUSIONS:Although it may improve arterial oxygen saturation, inappropriately high PEEP levels may reduce cardiac output, oxygen delivery, and respiratory system compliance in pediatric subjects with ARDS with low potential for lung recruitability.




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Accuracy of CAD4TB (Computer-Aided Detection for Tuberculosis) on paediatric chest radiographs

Background

Computer-aided detection (CAD) systems hold promise for improving tuberculosis (TB) detection on digital chest radiographs. However, data on their performance in exclusively paediatric populations are scarce.

Methods

We conducted a retrospective diagnostic accuracy study evaluating the performance of CAD4TBv7 (Computer-Aided Detection for Tuberculosis version 7) using digital chest radiographs from well-characterised cohorts of Gambian children aged <15 years with presumed pulmonary TB. The children were consecutively recruited between 2012 and 2022. We measured CAD4TBv7 performance against a microbiological reference standard (MRS) of confirmed TB, and also performed Bayesian latent class analysis (LCA) to address the inherent limitations of the MRS in children. Diagnostic performance was assessed using the area under the receiver operating characteristic curve (AUROC) and point estimates of sensitivity and specificity.

Results

A total of 724 children were included in the analysis, with confirmed TB in 58 (8%), unconfirmed TB in 145 (20%) and unlikely TB in 521 (72%). Using the MRS, CAD4TBv7 showed an AUROC of 0.70 (95% CI 0.60–0.79), and demonstrated sensitivity and specificity of 19.0% (95% CI 11–31%) and 99.0% (95% CI 98.0–100.0%), respectively. Applying Bayesian LCA with the assumption of conditional independence between tests, sensitivity and specificity estimates for CAD4TBv7 were 42.7% (95% CrI 29.2–57.5%) and 97.9% (95% CrI 96.6–98.8%), respectively. When allowing for conditional dependence between culture and Xpert assay, CAD4TBv7 demonstrated a sensitivity of 50.3% (95% CrI 32.9–70.0%) and specificity of 98.0% (95% CrI 96.7–98.9%).

Conclusion

Although CAD4TBv7 demonstrated high specificity, its suboptimal sensitivity underscores the crucial need for optimisation of CAD4TBv7 for detecting TB in children.




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Nonclinical Pharmacokinetics Study of OLX702A-075-16, N-Acetylgalactosamine Conjugated Asymmetric Small Interfering RNA (GalNAc-asiRNA) [Articles]

In this study, the nonclinical pharmacokinetics of OLX702A-075-16, an RNA interference therapeutic currently in development, were investigated. OLX702A-075-16 is a novel N-acetylgalactosamine conjugated asymmetric small-interfering RNA (GalNAc-asiRNA) used for the treatment of an undisclosed liver disease. Its unique 16/21-mer asymmetric structure reduces nonspecific off-target effects without compromising efficacy. We investigated the plasma concentration, tissue distribution, metabolism, and renal excretion of OLX702A-075-16 following a subcutaneous administration in mice and rats. For bioanalysis, high-performance liquid chromatography with fluorescence detection was used. The results showed rapid clearance from plasma (0.5 to 1.5 hours of half-life) and predominant distribution to the liver and/or kidney. Less than 1% of the liver concentration of OLX702A-075-16 was detected in the other tissues. Metabolite profiling using liquid chromatography coupled with high-resolution mass spectrometry revealed that the intact duplex OLX702A-075-16 was the major compound in plasma. The GalNAc moiety was predominantly metabolized from the sense strand in the liver, with the unconjugated sense strand of OLX702A-075-16 accounting for more than 95% of the total exposure in the rat liver. Meanwhile, the antisense strand was metabolized by the sequential loss of nucleotides from the 3'-terminus by exonuclease, with the rat liver samples yielding the most diverse truncated forms of metabolites. Urinary excretion over 96 hours was less than 1% of the administered dose in rats. High plasma protein binding of OLX702A-075-16 likely inhibited its clearance through renal filtration.

SIGNIFICANCE STATEMENT

This study presents the first comprehensive characterization of the in vivo pharmacokinetics of GalNAc-asiRNA. The pharmacokinetic insights gained from this research will aid in understanding toxicology and efficacy, optimizing delivery platforms, and improving the predictive power of preclinical species data for human applications.




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CYP8B1 Catalyzes 12alpha-Hydroxylation of C27 Bile Acid: In Vitro Conversion of Dihydroxycoprostanic Acid into Trihydroxycoprostanic Acid [Articles]

Sterol 12α-hydroxylase (CYP8B1) is the unique P450 enzyme with sterol 12-oxidation activity, playing an exclusive role in 12α-hydroxylating intermediates along the bile acid (BA) synthesis pathway. Despite the long history of BA metabolism studies, it is unclear whether CYP8B1 catalyzes 12α-hydroxylation of C27 BAs, the key intermediates shuttling between mitochondria and peroxisomes. This work provides robust in vitro evidence that both microsomal and recombinant CYP8B1 enzymes catalyze the 12α-hydroxylation of dihydroxycoprostanic acid (DHCA) into trihydroxycoprostanic acid (THCA). On the one hand, DHCA 12α-hydroxylation reactivity is conservatively detected in liver microsomes of both human and preclinical animals. The reactivity of human tissue fractions conforms well with the selectivity of CYP8B1 mRNA expression, while the contribution of P450 enzymes other than CYP8B1 is excluded by reaction phenotyping in commercial recombinant enzymes. On the other hand, we prepared functional recombinant human CYP8B1 proteins according to a recently published protocol. Titration of the purified CYP8B1 proteins with either C4 (7α-hydroxy-4-cholesten-3-one) or DHCA yields expected blue shifts of the heme Soret peak (type I binding). The recombinant CYP8B1 proteins efficiently catalyze 12α-hydroxylation of both DHCA and C4, with substrate concentration occupying half of the binding sites of 3.0 and 1.9 μM and kcat of 3.2 and 2.6 minutes–1, respectively. In summary, the confirmed role of CYP8B1 in 12α-hydroxylation of C27 BAs has furnished the forgotten passageway in the BA synthesis pathway. The present finding might have opened a new window to consider the biology of CYP8B1 in glucolipid metabolism and to evaluate CYP8B1 inhibition as a therapeutic approach of crucial interest for metabolic diseases.

SIGNIFICANCE STATEMENT

The academic community has spent approximately 90 years interpreting the synthesis of bile acids. However, the 12α-hydroxylation of intermediates catalyzed by CYP8B1 is not completely mapped on the classic pathway, particularly for the C27 bile acids, the pivotal intermediates shuttling between mitochondria and peroxisomes. This work discloses the forgotten 12α-hydroxylation pathway from dihydroxycoprostanic acid into trihydroxycoprostanic acid. The present finding may facilitate evaluating CYP8B1 inhibition as a therapeutic approach of crucial interest for metabolic diseases.




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Roles of the ABCG2 Transporter in Protoporphyrin IX Distribution and Toxicity [Special Section on New and Emerging Areas and Technologies in Drug Metabolism and Disposition, Part II-Minireview]

ATP-binding cassette transporter subfamily G member 2 (ABCG2) is a membrane-bound transporter responsible for the efflux of various xenobiotics and endobiotics, including protoporphyrin IX (PPIX), an intermediate in the heme biosynthesis pathway. Certain genetic mutations and chemicals impair the conversion of PPIX to heme and/or increase PPIX production, leading to PPIX accumulation and toxicity. In mice, deficiency of ABCG2 protects against PPIX-mediated phototoxicity and hepatotoxicity by modulating PPIX distribution. In addition, in vitro studies revealed that ABCG2 inhibition increases the efficacy of PPIX-based photodynamic therapy by retaining PPIX inside target cells. In this review, we discuss the roles of ABCG2 in modulating the tissue distribution of PPIX, PPIX-mediated toxicity, and PPIX-based photodynamic therapy.

SIGNIFICANCE STATEMENT

This review summarized the roles of ABCG2 in modulating PPIX distribution and highlighted the therapeutic potential of ABCG2 inhibitors for the management of PPIX-mediated toxicity.




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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.:




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Ghrelin Modulates Voltage-Gated Ca2+ Channels through Voltage-Dependent and Voltage-Independent Pathways in Rat Gastric Vagal Afferent Neurons [Article]

The orexigenic gut peptide ghrelin is an endogenous ligand for the growth hormone secretagogue receptor type 1a (GHSR1a). Systemic ghrelin administration has previously been shown to increase gastric motility and emptying. While these effects are known to be mediated by the vagus nerve, the cellular mechanism underlying these effects remains unclear. Therefore, the purpose of the present study was to investigate the signaling mechanism by which GHSR1a inhibits voltage-gated Ca2+ channels in isolated rat gastric vagal afferent neurons using whole-cell patch-clamp electrophysiology. The ghrelin pharmacological profile indicated that Ca2+ currents were inhibited with a log (Ic50) = –2.10 ± 0.44 and a maximal inhibition of 42.8 ± 5.0%. Exposure to the GHSR1a receptor antagonist (D-Lys3)-GHRP-6 reduced ghrelin-mediated Ca2+ channel inhibition (29.4 ± 16.7% vs. 1.9 ± 2.5%, n = 6, P = 0.0064). Interestingly, we observed that activation of GHSR1a inhibited Ca2+ currents through both voltage-dependent and voltage-independent pathways. We also treated the gastric neurons with either pertussis toxin (PTX) or YM-254890 to examine whether the Ca2+ current inhibition was mediated by the Gαi/o or Gαq/11 family of subunits. Treatment with both PTX (Ca2+ current inhibition = 15.7 ± 10.6%, n = 8, P = 0.0327) and YM-254890 (15.2 ± 11.9%, n = 8, P = 0.0269) blocked ghrelin’s effects on Ca2+ currents, as compared with control neurons (34.3 ± 18.9%, n = 8). These results indicate GHSR1a can couple to both Gαi/o and Gαq/11 in gastric vagal afferent neurons. Overall, our findings suggest GHSR1a-mediated inhibition of Ca2+ currents occurs through two distinct pathways, offering necessary insights into the cellular mechanisms underlying ghrelin’s regulation of gastric vagal afferents.

SIGNIFICANCE STATEMENT

This study demonstrated that in gastric vagal afferent neurons, activation of GHSR1a by ghrelin inhibits voltage-gated Ca2+ channels through both voltage-dependent and voltage-independent signaling pathways. These results provide necessary insights into the cellular mechanism underlying ghrelin regulation of gastric vagal afferent activity, which may benefit future studies investigating ghrelin mimetics to treat gastric motility disorders.




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Antenatal Care Interventions to Increase Contraceptive Use Following Birth in Low- and Middle-Income Countries: Systematic Review and Narrative Synthesis

ABSTRACTIntroduction:Health risks associated with short interpregnancy intervals, coupled with women’s desires to avoid pregnancy following childbirth, underscore the need for effective postpartum family planning programs. The antenatal period provides an opportunity to intervene; however, evidence is limited on the effectiveness of interventions aimed at reaching women in the antenatal period to increase voluntary postpartum family planning in low- and middle-income countries (LMICs). This systematic review aimed to identify and describe interventions in LMICs that attempted to increase postpartum contraceptive use via contacts with pregnant women in the antenatal period.Methods:Studies published from January 2012 to July 2022 were considered if they were conducted in LMICs, evaluated an intervention delivered during the antenatal period, were designed to affect postpartum contraceptive use, were experimental or quasi-experimental, and were published in French or English. The main outcome of interest was postpartum contraceptive use within 1 year after birth, defined as the use of any method of contraception at the time of data collection. We searched EMBASE, Global Health, and Medline and manually searched the reference lists from studies included in the full-text screening.Results:We double-screened 771 records and included 34 reports on 31 unique interventions in the review. Twenty-three studies were published from 2018 on, with 21 studies conducted in sub-Saharan Africa. Approximately half of the study designs (n=16) were randomized controlled trials, and half (n=15) were quasi-experimental. Interventions were heterogeneous. Among the 24 studies that reported on the main outcome of interest, 18 reported a positive intervention effect, with intervention recipients having greater contraceptive use in the first year postpartum.Conclusion:While the studies in this systematic review were heterogeneous, the findings suggest that interventions that included a multifaceted package of initiatives appeared to be most likely to have a positive effect.




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Development and Piloting of Implementation Strategies to Support Delivery of a Clinical Intervention for Postpartum Hemorrhage in Four sub-Saharan Africa Countries

ABSTRACTIntroduction:Postpartum hemorrhage (PPH) remains the leading cause of maternal mortality. A new clinical intervention (E-MOTIVE) holds the potential to improve early PPH detection and management. We aimed to develop and pilot implementation strategies to support uptake of this intervention in Kenya, Nigeria, South Africa, and Tanzania.Methods:Implementation strategy development: We triangulated findings from qualitative interviews, surveys and a qualitative evidence synthesis to identify current PPH care practices and influences on future intervention implementation. We mapped influences using implementation science frameworks to identify candidate implementation strategies before presenting these at stakeholder consultation and design workshops to discuss feasibility, acceptability, and local adaptations. Piloting: The intervention and implementation strategies were piloted in 12 health facilities (3 per country) over 3 months. Interviews (n=58), case report forms (n=1,269), and direct observations (18 vaginal births, 7 PPHs) were used to assess feasibility, acceptability, and fidelity.Results:Implementation strategy development: Key influences included shortages of drugs, supplies, and staff, limited in-service training, and perceived benefits of the intervention (e.g., more accurate PPH detection and reduced PPH mortality). Proposed implementation strategies included a PPH trolley, on-site simulation-based training, champions, and audit and feedback. Country-specific adaptations included merging the E-MOTIVE intervention with national maternal health trainings, adapting local PPH protocols, and PPH trollies depending on staff needs. Piloting: Intervention and implementation strategy fidelity differed within and across countries. Calibrated drapes resulted in earlier and more accurate PPH detection but were not consistently used at the start. Implementation strategies were feasible to deliver; however, some instances of limited use were observed (e.g., PPH trolley and skills practice after training).Conclusion:Systematic intervention development, piloting, and process evaluation helped identify initial challenges related to intervention fidelity, which were addressed ahead of a larger-scale effectiveness evaluation. This has helped maximize the internal validity of the trial.




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Factors Influencing the Central Nervous System (CNS) Distribution of the Ataxia Telangiectasia Mutated and Rad3-Related Inhibitor Elimusertib (BAY1895344): Implications for the Treatment of CNS Tumors [Metabolism, Transport, and Pharmacogenetics]

Glioblastoma (GBM) is a disease of the whole brain, with infiltrative tumor cells protected by an intact blood-brain barrier (BBB). GBM has a poor prognosis despite aggressive treatment, in part due to the lack of adequate drug permeability at the BBB. Standard of care GBM therapies include radiation and cytotoxic chemotherapy that lead to DNA damage. Subsequent activation of DNA damage response (DDR) pathways can induce resistance. Various DDR inhibitors, targeting the key regulators of these pathways such as ataxia telangiectasia mutated and Rad3-related (ATR), are being explored as radio- and chemosensitizers. Elimusertib, a novel ATR kinase inhibitor, can prevent repair of damaged DNA, increasing efficacy of DNA-damaging cytotoxic therapies. Robust synergy was observed in vitro when elimusertib was combined with the DNA-damaging agent temozolomide; however, we did not observe improvement with this combination in in vivo efficacy studies in GBM orthotopic tumor-bearing mice. This in vitro–in vivo disconnect was explored to understand factors influencing central nervous system (CNS) distribution of elimusertib and reasons for lack of efficacy. We observed that elimusertib is rapidly cleared from systemic circulation in mice and would not maintain adequate exposure in the CNS for efficacious combination therapy with temozolomide. CNS distribution of elimusertib is partially limited by P-glycoprotein efflux at the BBB, and high binding to CNS tissues leads to low levels of pharmacologically active (unbound) drug in the brain. Acknowledging the potential for interspecies differences in pharmacokinetics, these data suggest that clinical translation of elimusertib in combination with temozolomide for treatment of GBM may be limited.

SIGNIFICANCE STATEMENT

This study examined the disconnect between the in vitro synergy and in vivo efficacy of elimusertib/temozolomide combination therapy by exploring systemic and central nervous system (CNS) distributional pharmacokinetics. Results indicate that the lack of improvement in in vivo efficacy in glioblastoma (GBM) patient-derived xenograft (PDX) models could be attributed to inadequate exposure of pharmacologically active drug concentrations in the CNS. These observations can guide further exploration of elimusertib for the treatment of GBM or other CNS tumors.




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MIRD Pamphlet No. 30: MIRDfit--A Tool for Fitting of Biodistribution Time-Activity Data for Internal Dosimetry

In nuclear medicine, estimating the number of radioactive decays that occur in a source organ per unit administered activity of a radiopharmaceutical (i.e., the time-integrated activity coefficient [TIAC]) is an essential task within the internal dosimetry workflow. TIAC estimation is commonly derived by least-squares fitting of various exponential models to organ time–activity data (radiopharmaceutical biodistribution). Rarely, however, are methods used to objectively determine the model that best characterizes the data. Additionally, the uncertainty associated with the resultant TIAC is generally not evaluated. As part of the MIRDsoft initiative, MIRDfit has been developed to offer a biodistribution fitting software solution that provides the following essential features and advantages for internal dose assessment: nuclear medicine–appropriate fit functions; objective metrics for guiding best-fit selection; TIAC uncertainty calculation; quality control and data archiving; integration with MIRDcalc software for dose calculation; and a user-friendly Excel-based interface. For demonstration and comparative validation of MIRDfit’s performance, TIACs were derived from serial imaging studies involving 18F-FDG and 177Lu-DOTATATE using MIRDfit. These TIACs were then compared with TIAC estimates obtained using other software. In most cases, the TIACs agreed within approximately 10% between MIRDfit and the other software. MIRDfit has been endorsed by the MIRD Committee of the Society of Nuclear Medicine and Molecular Imaging and has been integrated into the MIRDsoft suite of free dosimetry software; it is available for download at no user cost (https://mirdsoft.org/).




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Intrapatient Intermetastatic Heterogeneity Determined by Triple-Tracer PET Imaging in mCRPC Patients and Correlation to Survival: The 3TMPO Cohort Study

Intrapatient intermetastatic heterogeneity (IIH) has been demonstrated in metastatic castration-resistant prostate cancer (mCRPC) patients and is of the utmost importance for radiopharmaceutical therapy (RPT) eligibility. This study was designed to determine the prevalence of IIH and RPT eligibility in mCRPC patients through a triple-tracer PET imaging strategy. Methods: This was a multisite prospective observational study in which mCRPC patients underwent both 18F-FDG and 68Ga-prostate-specific membrane antigen (PSMA)–617 PET/CT scans. A third scan with 68Ga-DOTATATE, a potential biomarker of neuroendocrine differentiation, was performed if an 18F-FDG–positive/68Ga-PSMA–negative lesion was found. Per-tracer lesion positivity was defined as having an uptake at least 50% above that of the liver. IIH prevalence was defined as the percentage of participants having at least 2 lesions with discordant features on multitracer PET. Results: IIH was observed in 81 patients (82.7%), and at least 1 18F-FDG–positive/68Ga-PSMA–negative lesion was found in 45 patients (45.9%). Of the 37 participants who also underwent 68Ga-DOTATATE PET/CT, 6 (16.2%) had at least 1 68Ga-DOTATATE–positive lesion. In total, 12 different combinations of lesion imaging phenotypes were observed. On the basis of our prespecified criteria, 52 (53.1%) participants were determined to be eligible for PSMA RPT, but none for DOTATATE RPT. Patients with IIH had a significantly shorter median overall survival than patients without IIH (9.5 mo vs. not reached; log-rank P = 0.03; hazard ratio, 2.7; 95% CI, 1.1–6.8). Conclusion: Most mCRPC patients showed IIH, which was associated with shorter overall survival. On the basis of a triple-tracer PET approach, multiple phenotypic combinations were found. Correlation of these imaging phenotypes with genomics and treatment response will be relevant for precision medicine.




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[18F]AlF-NOTA-FAPI-04 PET/CT for Predicting Pathologic Response of Resectable Esophageal Squamous Cell Carcinoma to Neoadjuvant Camrelizumab and Chemotherapy: A Phase II Clinical Trial

This single-center, single-arm, phase II trial (ChiCTR2100050057) investigated the ability of 18F-labeled fibroblast activation protein inhibitor ([18F]AlF-NOTA-FAPI-04, denoted as 18F-FAPI) PET/CT to predict the response to neoadjuvant camrelizumab plus chemotherapy (nCC) in locally advanced esophageal squamous cell carcinoma (LA-ESCC). Methods: This study included 32 newly diagnosed LA-ESCC participants who underwent 18F-FAPI PET/CT at baseline, of whom 23 also underwent scanning after 2 cycles of nCC. The participants underwent surgery after 2 cycles of nCC. Recorded PET parameters included maximum, peak, and mean SUVs and tumor-to-background ratios (TBRs), metabolic tumor volume, and total lesion FAP expression. PET parameters were compared between patient groups with good and poor pathologic responses, and the predictive performance for treatment response was analyzed. Results: The good and poor response groups each included 16 participants (16/32, 50.0%). On 18F-FAPI PET/CT, the posttreatment SUVs were significantly lower in good responders than in poor responders, whereas the changes in SUVs with treatment were significantly higher (all P < 0.05). SUVmax (area under the curve [AUC], 0.87; P = 0.0026), SUVpeak (AUC, 0.89; P = 0.0017), SUVmean (AUC, 0.88; P = 0.0021), TBRmax (AUC, 0.86; P = 0.0031), and TBRmean (AUC, 0.88; P = 0.0021) after nCC were significant predictors of pathologic response to nCC, with sensitivities of 63.64%–81.82% and specificities of 83.33%–100%. Changes in SUVmax (AUC, 0.81; P = 0.0116), SUVpeak (AUC, 0.82; P = 0.0097), SUVmean (AUC, 0.81; P = 0.0116), and TBRmean (AUC, 0.74; P = 0.0489) also were significant predictors of the pathologic response to nCC, with sensitivities and specificities in similar ranges. Conclusion: 18F-FAPI PET/CT parameters after treatment and their changes from baseline can predict the pathologic response to nCC in LA-ESCC participants.




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Granzyme B PET/CT Imaging Evaluates Early Response to Immunotherapy in Gastric Cancer

In several malignancies, only a limited number of patients respond to immune checkpoint inhibitors. Predicting and monitoring responses to these inhibitors represent an unmet clinical need. Here, we developed a PET/CT probe targeting granzyme B, [68Ga]Ga-NOTA-Gly-Gly-Gly-Ile-Glu-Pro-Asp-CHO (GSI), and aimed to investigate whether it can be used to monitor the effects of immune checkpoint inhibitors early in the course of therapy. Methods: Seventy-two patients with gastric cancer (stages III–IV) were recruited for [68Ga]Ga-NOTA-GSI PET/CT imaging after 2 or 3 cycles of the immunotherapy, and 40 patients were included in the final analysis. The SUVmax of primary tumors (SUVmax-t), SUVmax of metastatic lymph nodes (SUVmax-LN), and SUVmax of normal tissues (liver and blood pool) were measured, and their target-to-liver background ratio (TLR) and target-to-blood background ratio (TBR) were denoted for primary tumors as TLRtumor and TBRtumor and for metastatic lymph nodes as TLRLN and TBRLN, respectively. The treatment responses were assessed within 1 wk after full-course treatment according to RECIST version 1.1. Wilcoxon rank-sum tests were used to compare the PET/CT parameters between responders and nonresponders. Receiver operating characteristic curve analysis was used to assess the diagnostic efficacy of [68Ga]Ga-NOTA-GSI PET/CT parameters in identifying responders. Two-tailed P value of less than 0.05 was considered statistically significant. Results: We found that SUVmax-t, TLRtumor, TBRtumor, SUVmax-LN, and TBRLN were higher in responders than in nonresponders (2.49 ± 0.58 vs. 1.55 ± 0.48, P = 0.000; 2.24 ± 0.48 vs. 1.74 ± 0.67, P = 0.007; 1.38 ± 0.43 vs. 0.90 ± 0.23, P = 0.000; 2.24 ± 0.99 vs. 1.42 ± 0.55, P = 0.003; and 1.28 ± 0.68 vs. 0.83 ± 0.32, P = 0.012, respectively). According to receiver operating characteristic curve analysis, the area under the curve for SUVmax-t, TBRtumor, TLRtumor, SUVmax-LN, TLRLN, and TBRLN was 0.886, 0.866, 0.746, 0.772, 0.648, and 0.731, respectively. The threshold of SUVmax-t was 2.05, and its sensitivity and specificity were 81.0% and 84.2%, respectively. In addition, multivariate logistic regression indicated that TBRtumor was an independent predictor of treatment response (P = 0.03). Conclusion: Our results indicated that [68Ga]Ga-NOTA-GSI PET/CT is a promising tool for predicting early response to combined immunotherapy in gastric cancer patients.




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Reimagining Biologically Adapted Somatostatin Receptor-Targeted Radionuclide Therapy: Perspectives Based on Personal Experience and Observations on Recent Trials




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U.S. Imaging Costs: Michal Horny Talks with Ken Herrmann and Johannes Czernin About the Changing Contribution of Medical Imaging to Health Care Costs




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Nitric Oxide Signaling and Regulation in the Cardiovascular System: Recent Advances [75th Anniversary Celebration Collection Special Section]

Nitric oxide (NO) from endothelial NO synthase importantly contributes to vascular homeostasis. Reduced NO production or increased scavenging during disease conditions with oxidative stress contribute to endothelial dysfunction and NO deficiency. In addition to the classical enzymatic NO synthases (NOS) system, NO can also be generated via the nitrate-nitrite-NO pathway. Dietary and pharmacological approaches aimed at increasing NO bioactivity, especially in the cardiovascular system, have been the focus of much research since the discovery of this small gaseous signaling molecule. Despite wide appreciation of the biological role of NOS/NO signaling, questions still remain about the chemical nature of NOS-derived bioactivity. Recent studies show that NO-like bioactivity can be efficiently transduced by mobile NO-ferroheme species, which can transfer between proteins, partition into a hydrophobic phase, and directly activate the soluble guanylyl cyclase-cGMP-protein kinase G pathway without intermediacy of free NO. Moreover, interaction between red blood cells and the endothelium in the regulation of vascular NO homeostasis have gained much attention, especially in conditions with cardiometabolic disease. In this review we discuss both classical and nonclassical pathways for NO generation in the cardiovascular system and how these can be modulated for therapeutic purposes.

Significance Statement

After four decades of intensive research, questions persist about the transduction and control of nitric oxide (NO) synthase bioactivity. Here we discuss NO signaling in cardiovascular health and disease, highlighting new findings, such as the important role of red blood cells in cardiovascular NO homeostasis. Nonclassical signaling modes, like the nitrate-nitrite-NO pathway, and therapeutic opportunities related to the NO system are discussed. Existing and potential pharmacological treatments/strategies, as well as dietary components influencing NO generation and signaling are covered.




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Arterial Spin-Labeling Perfusion Lightbulb Sign: An Imaging Biomarker of Pediatric Posterior Fossa Hemangioblastoma [CLINICAL PRACTICE]

BACKGROUND AND PURPOSE:

Hemangioblastoma is a rare vascular tumor that occurs within the central nervous system in children. Differentiating hemangioblastoma from other posterior fossa tumors can be challenging on imaging, and preoperative diagnosis can change the neurosurgical approach. We hypothesize that a "lightbulb sign" on the arterial spin-labeling (ASL) sequence (diffuse homogeneous intense hyperperfusion within the solid component of the tumor) will provide additional imaging finding to differentiate hemangioblastoma from other posterior fossa tumors.

MATERIALS AND METHODS:

In this retrospective comparative observational study, we only included pathology-proved cases of hemangioblastoma, while the control group consisted of other randomly selected pathology-proved posterior fossa tumors from January 2022 to January 2024. Two blinded neuroradiologists analyzed all applicable MRI sequences, including ASL sequence if available. ASL was analyzed for the lightbulb sign. Disagreements between the radiologists were resolved by a third pediatric neuroradiologist. 2 and Fisher exact test were used to analyze the data.

RESULTS:

Ninety-five patients were enrolled in the study; 57 (60%) were boys. The median age at diagnosis was 8 years old (interquartile range: 3–14). Of the enrolled patients, 8 had hemangioblastoma, and 87 had other posterior fossa tumors, including medulloblastoma (n = 31), pilocytic astrocytoma (n = 23), posterior fossa ependymoma type A (n = 16), and other tumors (n = 17). The comparison of hemangioblastoma versus nonhemangioblastoma showed that peripheral edema (P = .02) and T2-flow void (P = .02) favor hemangioblastoma, whereas reduced diffusion (low ADC) (P = .002) and ventricular system extension (P = .001) favor nonhemangioblastoma tumors. Forty-two cases also had ASL perfusion sequences. While high perfusion favors hemangioblastoma (P = .03), the lightbulb sign shows a complete distinction because all the ASL series of hemangioblastoma cases (n = 4) showed the lightbulb sign, whereas none of the nonhemangioblastoma cases (n = 38) showed the sign (P < .001).

CONCLUSIONS:

Lightbulb-like intense and homogeneous hyperperfusion patterns on ASL are helpful in diagnosing posterior fossa hemangioblastoma in children.