Buprenorphine affects the initiation and severity of interleukin-induced acute pancreatitis in mice.

Acute pancreatitis (AP) is a common disease with no targeted therapy and has varied outcomes ranging from spontaneous resolution to being lethal. Although typically painful, AP can also be painless. Various agents, including opioids, are used for pain control in AP; the risks and benefits of which are often debated. As experimental AP in mice is used to study the efficacy of potential therapies, we studied the effect of a commonly used opioid, buprenorphine, on the initiation and progression of AP. For this, we administered extended-release buprenorphine subcutaneously before inducing the previously established severe AP model that uses interleukins 12 and 18 (IL12,18) in genetically obese (ob/ob) mice and compared this to mice with AP but without the drug. Mice were monitored over 3 days, and parameters of AP induction and progression were compared. Buprenorphine significantly reduced serum amylase, lipase, pancreatic necrosis, and AP-associated fat necrosis, which is ubiquitous in obese mice and humans. Buprenorphine delayed the AP-associated reduction of carotid artery pulse distention and the development of hypothermia, hastened renal injury, and muted the early increase in respiratory rate versus IL12,18 alone. The site of buprenorphine injection appeared erythematous, inflamed, and microscopically showed thinning, loss of epidermal layers that had increased apoptosis. In summary, subcutaneous extended-release buprenorphine interfered with the induction of AP by reducing serum amylase, lipase, pancreatic and fat necrosis, the worsening of AP by delaying hypotension, hypothermia, while hastening renal injury, respiratory depression, and causing cutaneous injury at the site of injection.NEW & NOTEWORTHY Extended-release buprenorphine interferes with the initiation and progression of acute pancreatitis at multiple levels.

Commonly disrupted pathways in brain and kidney in a pig model of systemic endotoxemia.

Sepsis is a life-threatening state that arises due to a hyperactive inflammatory response stimulated by infection and rarely other insults (e.g., non-infections tissue injury). Although changes in several proinflammatory cytokines and signals are documented in humans and small animal models, far less is known about responses within affected tissues of large animal models. We sought to understand the changes that occur during the initial stages of inflammation by administering intravenous lipopolysaccharide (LPS) to Yorkshire pigs and assessing transcriptomic alterations in the brain, kidney, and whole blood. Robust transcriptional alterations were found in the brain, with upregulated responses enriched in inflammatory pathways and downregulated responses enriched in tight junction and blood vessel functions. Comparison of the inflammatory response in the pig brain to a similar mouse model demonstrated some overlapping changes but also numerous differences, including oppositely dysregulated genes between species. Substantial changes also occurred in the kidneys following LPS with several enriched upregulated pathways (cytokines, lipids, unfolded protein response, etc.) and downregulated gene sets (tube morphogenesis, glomerulus development, GTPase signal transduction, etc.). We also found significant dysregulation of genes in whole blood that fell into several gene ontology categories (cytokines, cell cycle, neutrophil degranulation, etc.). We observed a strong correlation between the brain and kidney responses, with significantly shared upregulated pathways (cytokine signaling, cell death, VEGFA pathways) and downregulated pathways (vasculature and RAC1 GTPases). In summary, we have identified a core set of shared genes and pathways in a pig model of systemic inflammation.

Interleukin 21 Drives a Hypermetabolic State and CD4+ T-Cell-Associated Pathogenicity in Chronic Intestinal Inflammation.

BACKGROUND & AIMS: Incapacitated regulatory T cells (Tregs) contribute to immune-mediated diseases. Inflammatory Tregs are evident during human inflammatory bowel disease; however, mechanisms driving the development of these cells and their function are not well understood. Therefore, we investigated the role of cellular metabolism in Tregs relevant to gut homeostasis. METHODS: Using human Tregs, we performed mitochondrial ultrastructural studies via electron microscopy and confocal imaging, biochemical and protein analyses using proximity ligation assay, immunoblotting, mass cytometry and fluorescence-activated cell sorting, metabolomics, gene expression analysis, and real-time metabolic profiling utilizing the Seahorse XF analyzer. We used a Crohn's disease single-cell RNA sequencing dataset to infer the therapeutic relevance of targeting metabolic pathways in inflammatory Tregs. We examined the superior functionality of genetically modified Tregs in CD4+ T-cell-induced murine colitis models. RESULTS: Mitochondria-endoplasmic reticulum appositions, known to mediate pyruvate entry into mitochondria via voltage-dependent anion channel 1 (VDAC1), are abundant in Tregs. VDAC1 inhibition perturbed pyruvate metabolism, eliciting sensitization to other inflammatory signals reversible by membrane-permeable methyl pyruvate supplementation. Notably, interleukin (IL) 21 diminished mitochondria-endoplasmic reticulum appositions, resulting in enhanced enzymatic function of glycogen synthase kinase 3 ß, a putative negative regulator of VDAC1, and a hypermetabolic state that amplified Treg inflammatory response. Methyl pyruvate and glycogen synthase kinase 3 ß pharmacologic inhibitor (LY2090314) reversed IL21-induced metabolic rewiring and inflammatory state. Moreover, IL21-induced metabolic genes in Tregs in vitro were enriched in human Crohn's disease intestinal Tregs. Adoptively transferred Il21r-/- Tregs efficiently rescued murine colitis in contrast to wild-type Tregs. CONCLUSIONS: IL21 triggers metabolic dysfunction associated with Treg inflammatory response. Inhibiting IL21-induced metabolism in Tregs may mitigate CD4+ T-cell-driven chronic intestinal inflammation.

Opinion: Common Errors, Omissions, and Presentation Problems in the Conduct and Reporting of Animal-based Research.

As experienced authors, statisticians, editors, and scientists, we present the following comments to highlight some usages or omissions that are common in research manuscripts. Consideration of these comments will improve practices of data analysis and reporting.

Knee immobilization reproduces key arthrofibrotic phenotypes in mice.

AIMS: As has been shown in larger animal models, knee immobilization can lead to arthrofibrotic phenotypes. Our study included 168 C57BL/6J female mice, with 24 serving as controls, and 144 undergoing a knee procedure to induce a contracture without osteoarthritis (OA). METHODS: Experimental knees were immobilized for either four weeks (72 mice) or eight weeks (72 mice), followed by a remobilization period of zero weeks (24 mice), two weeks (24 mice), or four weeks (24 mice) after suture removal. Half of the experimental knees also received an intra-articular injury. Biomechanical data were collected to measure passive extension angle (PEA). Histological data measuring area and thickness of posterior and anterior knee capsules were collected from knee sections. RESULTS: Experimental knees immobilized for four weeks demonstrated mean PEAs of 141°, 72°, and 79° after zero, two, and four weeks of remobilization (n = 6 per group), respectively. Experimental knees demonstrated reduced PEAs after two weeks (p < 0.001) and four weeks (p < 0.0001) of remobilization compared to controls. Following eight weeks of immobilization, experimental knees exhibited mean PEAs of 82°, 73°, and 72° after zero, two, and four weeks of remobilization, respectively. Histological analysis demonstrated no cartilage degeneration. Similar trends in biomechanical and histological properties were observed when intra-articular violation was introduced. CONCLUSION: This study established a novel mouse model of robust knee contracture without evidence of OA. This was appreciated consistently after eight weeks of immobilization and was irrespective of length of remobilization. As such, this arthrofibrotic model provides opportunities to investigate molecular pathways and therapeutic strategies.Cite this article: Bone Joint Res 2023;12(1):58-71.

Corrigendum: Pharmacokinetic assessment of staphylococcal phage K following parenteral and intra-articular administration in rabbits.

[This corrects the article DOI: 10.3389/fphar.2022.840165.].

Pharmacokinetic Assessment of Staphylococcal Phage K Following Parenteral and Intra-articular Administration in Rabbits.

The therapeutic value of phage as an alternative to antibiotics for the treatment of bacterial infections is being considered in the wake of mounting antibiotic resistance. In this study, the pharmacokinetic properties of Staphylococcus aureus phage K following intravenous and intra-articular administration were investigated in a rabbit model. Using a traditional plaque assay and a novel quantitative PCR assay to measure phage levels in specimens over time, it was found that intra-articularly administered phage enters the systemic circulation; that phage may be detected in synovial fluid up to 24 h following the intra-articular, but not intravenous, administration; and that qPCR-based enumeration is generally more sensitive than plaque enumeration, with fair to moderate correlation between the two methods. Findings presented should inform the design of phage therapy experiments and therapeutic drug monitoring in preclinical and human phage studies.

Doppler-Guided Acoustically Active Injection Catheter: Transendocardial Delivery Assessed by an Efficacy Testing Animal Model.

Percutaneous transendocardial injections of therapeutic agents into the myocardium may not always be effective. We used an animal model for assessing the efficacy of the injections using linoleic acid as a testing agent. Efficacious delivery into the myocardium of a beating heart was indicated by rapidly developed local myocardial necrosis and wall motion abnormalities using echocardiography. We employed this experimental model to test our innovative technology, an acoustically active injection catheter. The Doppler ultrasound-guided acoustically active injection catheter effectively delivers the substance to the myocardium but needs further technical improvements to minimize an unwanted systemic distribution of the agent.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Gastrointestinal defect closure using a novel through-the-scope helix tack and suture device compared to endoscopic clips in a survival porcine model (with video).

Background and aims Endoscopic resections are associated with bleeding and perforation and may be managed with through-the-scope (TTS) clips, over-the-scope clips and endoscopic suturing. The aim of this preclinical study was to compare technical success of closure using a novel TTS tissue helix tack and suture device (X-Tack) to TTS clips in a porcine model. Materials and methods Four subjects underwent 40 mucosal resections, diameter range 25-50 mm, in the stomach (n = 24) and colon (n = 16). Closures were randomized to X-Tack (n = 24) or clip (n = 16). Animals underwent weekly endoscopic follow-up for 4 weeks. Results Technical closure with X-Tack was successful in 24 of 24 (100 %) cases and with clips in 13 of 16 cases (81.3 %) ( P  = 0.0001). One colonic perforation occurred and was successfully managed using X-Tack. The rate of healing was not statistically different between the groups, and all sites healed at 4 weeks including the perforation and were confirmed by histology. Conclusions Compared to TTS clip, X-Tack is superior for effecting large mucosal defect closure, including durable sealing of full-thickness perforation. There was no difference in rate of healing between devices.

Erratum: Gastrointestinal defect closure using a novel through-the-scope helix tack and suture device compared to endoscopic clips in a survival porcine model (with video).

[This corrects the article DOI: 10.1055/a-1370-9256.].

Lack of Absorption of a Sustained-release Buprenorphine Formulation Administered Subcutaneously to Athymic Nude Rats.

Female athymic nude rats (Rattus norvegicus; n = 45; age, 6 wk) were used in an IACUC-approved protocol to investigate mechanisms and potential treatments associated with brain, spine, and spinal cord metastases from triple negative breast cancer. The analgesic plan included the use of buprenorphine SR LAB (0.6 mg/kg; 0.11 mL/rat) subcutaneously and an oral NSAID delivered via the water. Thirty-seven rats reached the experimental end point at 3 mo after xenotransplantation and were euthanized for tissue harvest. Grossly, all 37 rats had nodules in the subcutis over the shoulders; these were identified as small, cystic structures (diameter, approximately 0.25 cm). The cysts and haired skin were submitted for LC-MS/MS (liquid chromatography-tandem mass spectrometry) and histopathology. Histologically, the cysts were lined by fibrous connective tissue mildly infiltrated by macrophages, lymphocytes, and plasma cells. Adjacent blood vessels were rimmed by a mild infiltrate of lymphocytes and plasma cells. The cysts contained variable accumulations of a light pink, proteinaceous fluid. The cause for the cysts could not be determined histologically; there was no evidence of neoplasia. LC-MS/MS analysis revealed that the cysts contained buprenorphine. We hypothesize that the lack of T cells and a cell-mediated immune response in these rats prevented the dissolution of the vehicle and absorption of the buprenorphine. The manufacturer provides a cautionary statement regarding the use of this formulation in nude mice due to skin reactions, but to our knowledge, this report is the first description of an apparent lack of absorption of the drug in immunodeficient animals.

Longitudinal evaluation of sexual function in a male cohort: the Olmsted county study of urinary symptoms and health status among men.

INTRODUCTION: The presence of erectile or ejaculatory dysfunction may indicate physical problems; however, individual perceptions (e.g., sexual satisfaction) may reflect the degree of concern about these changes. Long-term data showing how changes in multiple sexual function domains track together may be useful in understanding the importance of physical declines vs. sexual satisfaction. AIM: The aim of this study was to describe changes in sexual function among a population-based sample of aging men. METHODS: A population-based cohort study using data from the Olmsted County Study of Urinary Symptoms and Health Status among Men. Sexual function was assessed biennially from 1996 to 2004 using a previously validated questionnaire in a random sample of 2,213 men. MAIN OUTCOME MEASURES: Changes in erectile function, libido, ejaculatory function, sexual problems, and sexual satisfaction. RESULTS: Overall, we observed declines in all of the sexual function domains, ranging from an annual decrease of 0.03 point per year for sexual satisfaction to an annual decrease of 0.23 point per year in erectile function. Moderate correlations were observed among all longitudinal changes in sexual function (range in age-adjusted r(s) = 0.14-0.43); however, significantly smaller correlations between changes in the functional domains and changes in sexual satisfaction and problem assessment were observed among older men (range in age-adjusted r(s) = 0.03-0.29). CONCLUSION: Overall, these results demonstrate that longitudinal changes in five sexual function domains change together over time in our community-based cohort. Erectile function, ejaculatory function, and sexual drive decrease over time with greater rates of decline for older men. However, older men may be less likely to perceive these declines as a problem and be dissatisfied. These data may prove helpful to patients and clinicians in understanding and discussing changes in multiple aspects of sexual function.

Alpha-blocker use is associated with decreased risk of sexual dysfunction.

OBJECTIVES: To examine the association between alpha-blocker use and sexual dysfunction among men participating in a population-based cohort of men residing in Olmsted County, MN. Lower urinary tract symptoms (LUTS) in men have previously been associated with sexual dysfunction. The use of alpha-adrenergic receptor blocking agents results in an improvement in LUTS for many men. If sexual dysfunction and LUTS share a common etiology, alpha-blocker use might also be associated with a decreased risk of sexual dysfunction. METHODS: White men, aged 40-79 years, were randomly selected in 1990 and assessed for alpha-blocker use and LUTS severity. Sexual function was assessed using the Brief Male Sexual Function Inventory. Men who used alpha-blockers before any sexual dysfunction were considered "exposed." Hazard ratios and 95% confidence intervals were estimated separately for each sexual function domain using Cox proportional hazard models. RESULTS: Of the 1724 men with a regular sexual partner included in the present study (mean age 57.74 years), 263 (15.3%) reported alpha-blocker use. alpha-Blocker use was associated with a decreased risk of sexual dysfunction across all domains for men > or =50 years old (age-adjusted hazard ratio 0.53-0.69). A decreased risk of erectile dysfunction and low libido remained significant only among those using alpha-blockers who also experienced an improvement in LUTS (P = .01). CONCLUSIONS: The use of alpha-blockers for LUTS was associated with a decreased risk of sexual dysfunction. Improvement in sexual function correlated with the improvement in LUTS more strongly among those using alpha-blockers.

The associations between serum sex hormones, erectile function, and sex drive: the Olmsted County Study of Urinary Symptoms and Health Status among Men.

INTRODUCTION: Testosterone replacement therapy has been used in the treatment of sexual dysfunction; however, its use remains controversial, and the effectiveness and long-term health implications are unknown. AIM: To evaluate the association between sex hormone serum levels, erectile function, and sexual drive in a population-based sample of men. METHODS: A stratified random sample of men residing in Olmsted County, Minnesota, completed a questionnaire containing questions from the Brief Male Sexual Function Inventory (BMSFI), and participated in a clinical exam, which included serum hormone measurements. MAIN OUTCOME MEASURES: Levels of sexual drive (libido) and erectile function as assessed by the BMSFI and serum testosterone, bioavailable testosterone, and estradiol measurements. RESULTS: Out of 414 men, 294 had a regular sexual partner and androgen measurements at the 14th year of follow-up. Total testosterone and erectile function were significantly correlated even after adjustment for age (r = 0.12, P = 0.04). Conversely, total testosterone was not significantly correlated with sex drive (r = 0.08, P = 0.17). Bioavailable testosterone was significantly correlated with both erectile function and sex drive (r = 0.16, P = 0.01 and r = 0.20, P = 0.001, respectively). However, these associations disappeared after age adjustment (r = 0.04 and r = 0.09). CONCLUSIONS: These cross-sectional results suggest the relationship between sex hormones and sexual function is complex, and that the age-related decline in sexual function may be due to age-related declines in levels of bioavailable testosterone rather than total testosterone levels.