NewPath Research

Methane emissions at oil and gas facilities can be measured in real time with continuous monitoring systems that alert operators of upset conditions, including fugitive emissions. We report on extensive operator field testing of a continuous laser monitoring system in ~year-long deployments at 46 oil and gas sites in two U.S. basins. The operator assessed periods of non-alerts with daily optical gas imaging sweeps to confirm emission status. Detection precision was 98% and false positive and negative rates were 3%. Quantification of challenge-controlled release tests at active oil and gas sites yielded a measured versus true emissions curve with slope = 1.2, R2 = 0.90. Repeatability test measurements of four production facilities with two different laser systems showed 33.9% average quantification agreement. Separate third-party blind controlled release testing at two state-of-the-art test facilities yielded 100% true positive rate (0 false negatives). Combining the third-party blind tests with field tests, emission rate quantification uncertainty was +/−41% across five orders of magnitude. These varied evaluation approaches validate the measurement system and operator integration of data for measurement and monitoring of upstream oil and gas emissions and demonstrate a test regime for vetting of monitoring and measurement technologies in active oil and gas operations.

The 2025 Town Hall meeting of the Society of Toxicologic Pathology (STP) discussed virtual control groups (VCG) in nonclinical toxicity testing, which are being pursued by multiple organizations to reduce animal use in product development. The current VCG literature infrequently reflects the toxicologic pathology perspective. Audience members noted that concurrent control groups (CCG) are the gold standard for toxicity studies, essential for replenishing the historical control data (HCD) from which VCG are generated. The utility of VCG is context-dependent: acceptable when test article (TA)-related effects are easily separated from background findings but likely unsuitable where subtle findings must be distinguished. Global regulatory acceptance is of paramount concern in trying to shift from CCG to partly or wholly relying on VCG. Alternative approaches to reduce animal use include eliminating studies that are a common regulatory expectation but lack scientific justification, obtaining early regulatory agreement that single-species testing is sufficient, and altering study designs to reduce group numbers, sharing CCG, or blending CCG and VCG. The most effective way for toxicologic pathologists to influence this debate is to dispassionately consider opportunities and challenges of VCG related to pathology diagnoses and interpretations and communicate this perspective clearly to the broader (non-pathologist) scientific community.

ABSTRACT Due to the prevalence of hematoxylin and eosin (H&E) staining in routine histological preparations, understanding the factors that impact stain color characteristics is vital to attain consistently high-quality stains. In the last decade, increased use of digital pathology and image analysis (specifically by optical density [OD] measures) has provided new ways of assessing staining precision. This paper combines data from two studies that tracked H&E staining quality in both nuclear and cytoplasmic components of 12 tissues (11 human and 1 porcine) by OD after overuse of H&E staining reagents from 5 vendors. Both studies showed a decrease in eosin stain intensity by OD and visual inspection (by a histologist) with reagent overuse. This trend varied in degree by tissue type and reagent vendor. Nonetheless, staining quality for H&E staining from all vendors and for all organs remained acceptable (but not always optimal) for microscopic evaluation by the College of American Pathologists (CAP) and National Society for Histotechnology (NSH) staining criteria when stained sections were reviewed by a board-certified veterinary pathologist.

Historically, safety and efficacy assessment of medical devices began and has continued as standards under the International Organization for Standardization (ISO) rather than under regulatory agency guidelines applied to developing other biomedical product classes. These parallel and unequal pathways have led to multiple and substantive differences in methods and endpoints to determine adverse biological responses among therapeutic classes. Toxicologic pathologists with medical device experience consider standardized nomenclature and diagnostic criteria for medical devices and device-containing combination products as a critical unmet need for nonclinical pathology evaluations. The International Harmonization of Nomenclature and Diagnostic Criteria for Lesions (INHAND) initiative has established globally accepted terminology for proliferative and nonproliferative lesions in various laboratory animal species. Experienced pathologists have identified that some existing INHAND terms for rodents and particularly nonrodents are already used or can be modified for use in medical device studies, but new terms for diagnostic features unique to medical device studies are needed to close gaps in existing INHAND nomenclature. The best approach to establishing appropriate INHAND terms for medical devices (and by extension, device-containing combination products) will be to develop and implement suitable terminology (modified and new, as warranted) to address unmet needs for this distinctive therapeutic class.

Conventional methods of gene transfer lead to inconsistent transgene expression within cells. This variability can be problematic, particularly in conditions like Rett syndrome (RTT), a neurological disorder caused by mutations in the MECP2 (methyl-CpG binding protein 2) gene, because overexpression of MECP2 can also cause adverse effects. To address these challenges, we devised a gene regulation system called Expression Attenuation via Construct Tuning (EXACT), which uses a self-contained, microRNA-based feed-forward loop that not only ensures more consistent transgene expression but also protects against excessive expression. Through cell-based screening assays, we demonstrated the ability of the EXACT circuit to modulate the expression of full-length human MeCP2. Compared with a conventional construct, an EXACT-MECP2 construct exhibited a narrower range of cellular protein abundance. Furthermore, the degree of regulation by the EXACT circuit increased with higher transgene doses in vitro and in wild-type mice and mice modeling RTT. On the basis of cellular and in vivo testing, we identified an optimal configuration for the adeno-associated virus serotype 9 (AAV9) construct for self-regulated MECP2 gene therapy, designated NGN-401. Delivery of NGN-401 to neonatal male Mecp2-/y hemizygous mice via intracerebroventricular injection resulted in prolonged survival and amelioration of RTT-like phenotypes compared with vehicle-treated animals. NGN-401 was also well tolerated by female Mecp2+/- mice and healthy juvenile nonhuman primates, in contrast with a conventional construct, which caused toxicity. The results from these studies underpin a first-in-human pediatric trial of NGN-401 in RTT (ClinicalTrials.gov, NCT05898620).

Mid-infrared dual comb spectroscopy is capable of multispecies detection with a high resolution. We discuss the design and mobilization of an intrapulse difference frequency generation dual comb spectrometer with <70 L volume.

ABSTRACTMitogen-activated protein 3 kinase 1 (MAP3K1) has a plethora of cell type-specific functions not yet fully understood. Herein, we describe a role for MAP3K1 in female reproductive tract (FRT) development. MAP3K1 kinase domain-deficient female mice exhibited an imperforate vagina, labor failure and infertility. These defects corresponded with shunted Müllerian ducts (MDs), the embryonic precursors of FRT, that manifested as a contorted caudal vagina and abrogated vaginal–urogenital sinus fusion in neonates. The MAP3K1 kinase domain is required for optimal activation of the Jun-N-terminal kinase (JNK) and cell polarity in the MD epithelium, and for upregulation of WNT signaling in the mesenchyme surrounding the caudal MD. The MAP3K1-deficient epithelial cells and MD epithelium had reduced expression of WNT7B ligands. Correspondingly, conditioned media derived from MAP3K1-competent, but not -deficient, epithelial cells activated a TCF/Lef-luciferase reporter in fibroblasts. These observations indicate that MAP3K1 regulates MD caudal elongation and FRT development, in part through the induction of paracrine factors in the epithelium that trans-activate WNT signaling in the mesenchyme.