Sex-specific diet differences in harbor seals (Phoca vitulina) via spatial assortment.

The lack of recovery of Chinook salmon (Oncorhynchus tshawytscha) in the Pacific Northwest has been blamed in part on predation by pinnipeds, particularly the harbor seal (Phoca vitulina). Previous work at a limited number of locations has shown that male seal diet contains more salmon than that of female seals and that sex ratios at haul-out sites differ spatiotemporally. This intrapopulation variation in predation may result in greater effects on salmon than suggested by models assuming equal spatial distribution and diet proportion. To address the generality of these patterns, we examined the sex ratios and diet of male and female harbor seals from 13 haul-out sites in the inland waters of Washington State and the province of British Columbia during 2012-2018. DNA metabarcoding was conducted to determine prey species proportions of individual scat samples. The sex of harbor seals was then determined from each scat matrix sample with the use of quantitative polymerase chain reaction (qPCR). We analyzed 2405 harbor seal scat samples using generalized linear mixed models (GLMMs) to examine the factors influencing harbor seal sex ratio at haul-out sites and permutational multivariate analysis of variance (PERMANOVA) to examine the influence of sex and haul-out site on harbor seal diet composition. We found that the overall sex ratio was 1:1.02 (female:male) with notable spatiotemporal variation. Salmoniformes were about 2.6 times more abundant in the diet of males than in the diet of females, and Chinook salmon comprised ca. three times more of the average male harbor seal's diet than the average female's diet. Based on site-specific sex ratios and diet data, we identified three haul-out sites where Chinook salmon appear to be under high predation pressure by male harbor seals: Cowichan Bay, Cutts Area, and Fraser River. Our study indicates that combining sex-specific pinniped diet data with the sex ratio of haul-out sites can help identify priority sites of conservation concern.

Successful Treatment of Tenofovir Alafenamide-Induced Lactic Acidosis: A Case Report.

Nucleoside or nucleotide analogues (NAs) have the potential to cause lactic acidosis by inhibiting DNA polymerase-γ of human mitochondria and impairing aerobic metabolism. Patients may be asymptomatic, have mild non-specific symptoms, or present in multisystem organ failure. There is a paucity of data to guide management of life-threatening lactic acidosis due to NA therapy. Here we describe a case of a 60-year old critically ill male with decompensated cirrhosis secondary to hepatitis B virus (HBV) infection who developed severe lactic acidosis (13.8 mmol/L) 2 days after initiation of tenofovir alafenamide (TAF). All other possible etiologies for the elevated lactate were ruled out. Lactic acidosis resolved rapidly with TAF discontinuation and supplementation with cofactors supporting mitochondrial oxidative phosphorylation, including coenzyme Q10, levocarnitine, riboflavin, and thiamine. This case highlights the ability of TAF to cause lactic acidosis early after therapy initiation, especially in susceptible hosts, and reviews the potential role for cofactor supplementation for drug-induced mitochondrial injury.

PACAP-expressing neurons in the lateral habenula diminish negative emotional valence.

The lateral habenula (LHb) is a small, bilateral, epithalamic nucleus which processes aversive information. While primarily glutamatergic, LHb neurons express genes coding for many neuropeptides, such as Adcyap1 the gene encoding pituitary adenylate cyclase-activating polypeptide (PACAP), which itself has been associated with anxiety and stress disorders. Using Cre-dependent viral vectors, we targeted and characterized these neurons based on their anatomical projections and found that they projected to both the raphe and rostromedial tegmentum but only weakly to ventral tegmental area. Using RiboTag to capture ribosomal-associated mRNA from these neurons and reanalysis of existing single cell RNA sequencing data, we did not identify a unique molecular phenotype that characterized these PACAP-expressing neurons in LHb. In order to understand the function of these neurons, we conditionally expressed hM3 Dq DREADD selectively in LHb PACAP-expressing neurons and chemogenetically excited these neurons during behavioral testing in the open field test, contextual fear conditioning, sucrose preference, novelty suppressed feeding, and conditioned place preference. We found that Gq activation of these neurons produce behaviors opposite to what is expected from the LHb as a whole-they decreased anxiety-like and fear behavior and produced a conditioned place preference. In conclusion, PACAP-expressing neurons in LHb represents a molecularly diverse population of cells that oppose the actions of the remainder of LHb neurons by being rewarding or diminishing the negative consequences of aversive events.

Towards a generic method for ion chromatography/mass spectrometry of low-molecular-weight amines in pharmaceutical drug discovery and development.

RATIONALE: Low-molecular-weight amines are encountered in pharmaceutical analysis, e.g. as reactants in chemical syntheses, but are challenging to analyse using ultrahigh-performance liquid chromatography/mass spectrometry (UHPLC/MS) due to their high polarity causing poor retention. Ion chromatography/mass spectrometry (IC/MS) is an emerging technique for polar molecule analysis that offers better separation. A generic IC/MS method would overcome problems associated with using UHPLC/MS in drug discovery and development environments. METHODS: Amine standards were analysed using IC/MS with gradient elution (variety of column temperatures evaluated). An electrospray ionisation (ESI) quadrupole mass spectrometer was operated in positive ion polarity in scanning mode. The make-up flow composition was evaluated by assessing the performance of a range of organic modifiers (acetonitrile, ethanol, methanol) and additives (acetic acid, formic acid, methanesulfonic acid). The ESI conditions were optimised to minimise adduct formation and promote generation of protonated molecules. RESULTS: The performance attributes were investigated and optimised for low-molecular-weight amine analysis. Organic solvents and acidic additives were evaluated as make-up flow components to promote ESI, with 0.05% acetic acid in ethanol optimal for producing protonated molecules. The hydrogen bonding capability of amines led to abundant protonated molecule-solvent complexes; optimisation of source conditions reduced these, with collision-induced dissociation voltage having a strong effect. The detection limit was ≤1.78 ng for the amines analysed, which is fit-for-purpose for an open-access chemistry environment. CONCLUSIONS: This study demonstrates the value of IC/MS for analysing low-molecular-weight amines. Good chromatographic separation of mixtures was possible without derivatisation. Ionisation efficiency was greatest using a make-up flow of 0.05% acetic acid in ethanol, and optimisation of ESI source conditions promoted protonated molecule generation for easy determination of molecular weight.

Best practices to optimize utilization of the National Living Donor Assistance Center for the financial assistance of living organ donors.

Living organ donors face direct costs when donating an organ, including transportation, lodging, meals, and lost wages. For those most in need, the National Living Donor Assistance Center (NLDAC) provides reimbursement to defray travel and subsistence costs associated with living donor evaluation, surgery, and follow-up. While this program currently supports 9% of all US living donors, there is tremendous variability in its utilization across US transplant centers, which may limit patient access to living donor transplantation. Based on feedback from the transplant community, NLDAC convened a Best Practices Workshop on August 2, 2018, in Arlington, VA, to identify strategies to optimize transplant program utilization of this valuable resource. Attendees included team members from transplant centers that are high NLDAC users; the NLDAC program team; and Advisory Group members. After a robust review of NLDAC data and engagement in group discussions, the workgroup identified concrete best practices for administrative and transplant center leadership involvement; for individuals filing NLDAC applications at transplant centers; and to improve patient education about potential financial barriers to living organ donation. Multiple opportunities were identified for intervention to increase transplant programs' NLDAC utilization and reduce financial burdens inhibiting expansion of living donor transplantation in the United States.

Effects of Short-term Temperature Change in the Innocuous Range on Histaminergic and Non-histaminergic Acute Itch.

While temperatures in the noxious range are well-known to inhibit acute itch, the impact of temperature in the innocuous temperature range is less well understood. We investigated the effect of alternating short-term temperature changes in the innocuous range on histamine and cowhage-induced acute itch, taking into account individual differences in baseline skin temperature and sensory thresholds. Results indicate that cooling the skin to the cold threshold causes a temporary increase in the intensity of histamine-induced itch, in line with previous findings. Skin warming increased cowhage-induced itch intensity. Potential mecha-nisms of this interaction between thermosensation and pruritoception could involve cold-sensitive channels such as TRPM8, TREK-1 or TRPC5 in the case of histamine. The rapid modulation of cowhage induced itch - but not histamine-induced itch - by transient skin warming could be related to the lower temperature threshold of pruriceptive polymodal C-fibres (cowhage) as compared to the higher temperature threshold of the mechanoinsensitive C-fibres conveying histaminergic itch.

Copy number variant discrepancy resolution using the ClinGen dosage sensitivity map results in updated clinical interpretations in ClinVar.

Conflict resolution in genomic variant interpretation is a critical step toward improving patient care. Evaluating interpretation discrepancies in copy number variants (CNVs) typically involves assessing overlapping genomic content with focus on genes/regions that may be subject to dosage sensitivity (haploinsufficiency (HI) and/or triplosensitivity (TS)). CNVs containing dosage sensitive genes/regions are generally interpreted as "likely pathogenic" (LP) or "pathogenic" (P), and CNVs involving the same known dosage sensitive gene(s) should receive the same clinical interpretation. We compared the Clinical Genome Resource (ClinGen) Dosage Map, a publicly available resource documenting known HI and TS genes/regions, against germline, clinical CNV interpretations within the ClinVar database. We identified 251 CNVs overlapping known dosage sensitive genes/regions but not classified as LP or P; these were sent back to their original submitting laboratories for re-evaluation. Of 246 CNVs re-evaluated, an updated clinical classification was warranted in 157 cases (63.8%); no change was made to the current classification in 79 cases (32.1%); and 10 cases (4.1%) resulted in other types of updates to ClinVar records. This effort will add curated interpretation data into the public domain and allow laboratories to focus attention on more complex discrepancies.

Pancreatic cancer surveillance among high-risk populations: knowledge and intent.

Pancreatic cancer is the fourth most common cancer in both men and women in the United States. It has the lowest survival rate of all cancers, largely due to the presence of non-specific symptoms, leading to diagnosis at advanced stages. While the majority of cases of pancreatic cancer are sporadic, up to 10% may be associated with an inherited predisposition. Currently, there is no standard screening protocol for pancreatic cancer, although this will change in the future as technology improves. Additionally, there is little information regarding the perceptions and intent to screen for pancreatic cancer among those with an increased risk due to a hereditary cancer predisposition syndrome, which was the objective of this study. Focus groups and individual telephone interviews were conducted, with questions focused on knowledge about pancreatic cancer and screening, perceived motivators, and perceived barriers related to each of the screening techniques currently available. Participants were recruited from the High Risk Breast Cancer and Pancreatic Cancer Registries at Huntsman Cancer Institute. The findings of this study indicated that individuals from these high-risk groups have low knowledge levels of pancreatic cancer screening, despite their desire for this information. Motivation to undergo a particular screening technique is related to whether the test is recommended by a physician, cost, degree of invasiveness, and comfort level. This information is useful to genetics professionals who counsel at-risk individuals, physicians who formulate patient care plans, and translational researchers who are developing pancreatic screening methods.