BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD), and its more severe form, nonalcoholic steatohepatitis (NASH), is the leading cause for liver failure and liver cancer. Although the etiology is likely multifactorial, genes involved in regulating lipid metabolism are enriched in human NAFLD genome-wide association studies (GWAS), pointing to dysregulated lipid metabolism as a major pathogenic factor. Glycerol-3-phosphate acyltransferase 1 (GPAT1), encoded by GPAM, converts acyl-CoAs and glycerol-3phosphate into lysophosphatidic acid and has been shown to regulate lipid accumulation in the liver. However, its role in mediating the progression from NAFLD to NASH has not been explored. METHODS: GPAT1-deficient mice were generated and challenged with diets inducing hepatic steatosis and NASH. Effects of GPAT1 deficiency on lipid and systemic metabolic end points were evaluated. RESULTS: Ablating GPAT1 globally or specifically in mouse hepatocytes reduced hepatic steatosis in the context of dietinduced or genetic obesity. Interestingly, blunting of progression from NAFLD to NASH in global GPAT1 knockout (KO) mice was model dependent. GPAT1 KO mice were protected from choline deficient, amino acid defined high-fat diet-induced NASH development, but not from the high fat, high carbohydrate, and high cholesterol diet-induced NASH. CONCLUSIONS: Our preclinical data support the notion that lipid metabolism pathways regulated by GPAT1 in hepatocytes play an essential role in NASH progression, albeit in a modeldependent manner. (Cell Mol Gastroenterol Hepatol 2024; 17:279-291; https://doi.org/10.1016/j.jcmgh.2023.10.002)

Malignant hyperthermia susceptibility (MHS) and the associated condition malignant hyperthermia (MH) are rare but well-known disorders in the field of anesthesiology. MHS is usually determined by a history of a family member developing a positive episode during general anesthesia and then confirmed by an invasive caffeine halothane contracture test (CHCT). More recently, within the context of MH as a pharmacogenetic disorder, the question of whether or not MHS can be principally genetically determined is of high importance as knowledge of detailed pathogenesis may prevent against its largely invariable lethality if untreated. Thus, in this brief report, genetic terms, as well as updates in the genetics of MHS, will be reviewed in order to better understand both the condition and the current research.

Regular exercise (EX) is recommended in addition to pharmacotherapies for the management of type 2 diabetes (T2D), but patients with T2D often have difficulty tolerating EX. Additionally, some studies report that the combination of metformin, the first line pharmacotherapy for T2D, and EX may have non‐additive or even inhibitory effects on glycemic control and aerobic capacity. Therefore, further investigation into the combination of EX with alternative T2D medications is needed. The objectives of this study were to 1) determine whether co‐treatment with a sodium‐glucose cotransporter 2 inhibitor (SGLT2i), a new class of T2D medication, and EX further improve glycemic control when compared to SGLT2i alone and 2) assess whether the addition of SGLT2i to EX affects exercise tolerance. It was hypothesized that SGLT2i combined with EX would further improve indices of glycemic control when compared to SGLT2i alone and that the combination of therapies would not worsen exercise tolerance. All procedures performed were in accordance with established regulations and guidelines and were approved by the Pfizer IACUC. A low‐dose streptozotocin (30 mg/kg) and high‐fat feeding model was used to induce T2D in male Sprague Dawley rats. Animals were then randomized to the following conditions (n=7–10 animals/group): vehicle (0.5% methylcellulose) and sedentary (VEH SED), VEH EX, canagliflozin (3 mg/kg/d) SED (SGLT2i SED), or SGLT2i EX for 12 weeks. EX consisted of treadmill running for 60 min/d, 5d/wk, on a 10% incline at ~50–55% of the maximal running speed obtained from a VO2peak test. Reported values are the mean ± SEM. EX had lower body weight (p<0.05) and body fat percentage (p<0.01) compared to SED. SGLT2i EX tended to have ~10% lower body weight than VEH EX (p=0.07), with similar body fat percentage (p=0.74 vs. SGLT2i SED). EX improved glucose (glu) area under the curve ~27% (AUC; p<0.001 vs SED) during a glucose tolerance test, with no differences between VEH EX and SGLT2i EX (p=0.08). SGLT2i had lower fasting glu and insulin, HOMA‐IR, glu AUC, and insulin AUC vs. VEH (p<0.05 for each). SGLT2i EX demonstrated further improvements in HOMA‐IR (3.0±1.0 vs. 6.5±1.2, p≤0.05) and glu AUC (19976± 934 vs. 25718± 1483 mg/dl/120 min, p=0.01), and tended to have lower insulin AUC (140±24 vs 160±23 ng/ml/120 min, p=0.056) vs. SGLT2i SED. As expected, EX had higher VO2peak and maximal running speed during VO2peak (p<0.05), with no differences between EX groups. Interestingly, at submaximal running speeds (50–75% maximal running speed), SGLT2i EX ran further before fatigue than VEH EX (882±183 vs 417±34 m, p<0.05); this was accompanied by a lower respiratory exchange ratio (0.81 vs 0.86, p<0.01) at the same VO2. When taken together, these findings suggest that the combination of SGLT2i and EX may further improve glycemic control vs. SGLT2i alone. Additionally, the combination of therapies may improve exercise tolerance, which could have potent metabolic effects in this population.Support or Funding InformationAuthors TTR, DAB, and WPE are employees and shareholders of Pfizer. MAL is a former employee of Pfizer. BB has consulted for Pfizer, Inc. MAL, KLH, BFM, and BB have received research funding from Pfizer, Inc.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Increased fructose consumption and its subsequent metabolism have been implicated in hepatic steatosis, dyslipidemia, obesity, and insulin resistance in humans. Since ketohexokinase (KHK) is the principal enzyme responsible for fructose metabolism, identification of a selective KHK inhibitor may help to further elucidate the effect of KHK inhibition on these metabolic disorders. Until now, studies on KHK inhibition with small molecules have been limited due to the lack of viable in vivo pharmacological tools. Herein we report the discovery of 12, a selective KHK inhibitor with potency and properties suitable for evaluating KHK inhibition in rat models. Key structural features interacting with KHK were discovered through fragment-based screening and subsequent optimization using structure-based drug design, and parallel medicinal chemistry led to the identification of pyridine 12.

Insertion of tympanostomy tubes is a common elective pediatric surgical procedure and is typically performed under general anesthesia. The potential to reduce general anesthetic requirements for young children has led to increased interest in alternatives for tympanostomy tube placement. A tympanostomy tube system, developed to enable tympanostomy tube placement in a single pass on conscious patients under moderate sedation, was evaluated. A prospective study on 128 children and 253 tympanostomy tube placements conducted at 4 centers in the United States demonstrated an 88.3% success rate in performing the procedure under moderate sedation with adverse events within normal rates reported in the literature. The feasibility of completing tympanostomy tube placement under moderate sedation enables avoidance of general anesthesia and provides additional choices to physicians and parents.

BACKGROUND Intraoperative hypotension secondary to acute blood loss and fluid shifts increases morbidity and mortality. Intrathoracic pressure regulation (IPR) is a new therapy that enhances circulation by increasing venous return with a negative intrathoracic pressure created non-invasively, either actively (vacuum source or patient inspiration) or passively (chest recoil during cardiopulmonary resuscitation).OBJECTIVE In this Phase II pilot study, we tested the hypothesis that active IPR therapy would improve the haemodynamic status of patients who developed clinically significant hypotension during abdominal surgery.DESIGN A phase II, single cohort, interventional pilot study.SETTING University of Minnesota Fairview Hospital.PATIENTS Twenty-two patients [American Society of Anesthesiologists (ASA) physical status I to III] were enrolled prospectively of whom 15 experienced intraoperative hypotension.INTERVENTION If intraoperative hypotension occurred more than 10 min after induction, the IPR device was applied immediately for a minimum of 10 min.MAIN OUTCOME MEASURE The hypotensive SBP immediately before the start of IPR treatment was compared with the SBP obtained at the end of IPR therapy. The paired Student's t-test was used to determine statistical significance (P< 0.05).RESULTS Fifteen of the 22 patients enrolled experienced 18 hypotensive episodes, which were treated with at least 10 min of IPR therapy. Fourteen episodes responded to IPR alone and four episodes (four patients) required additional fluid and vasopressor therapy to treat the hypotension. The group mean +/- SD SBPs at the onset of the IPR treatment and at the end of IPR treatment were 90.7 +/- 9.7 and 98.4 +/- 17.4mmHg (P = 0.02), respectively. The maximum SBP reached during the treatment was 105.6 +/- 19.6 mmHg. Pulse pressure increased from 36.8 +/- 8.5 mmHg immediately before IPR treatment to 41.5 +/- 11.1mmHg (P = 0.02) at the end of IPR treatment. Mean arterial pressure (MAP) increased from 66.3 +/- 9.4mmHg immediately before IPR treatment to 71.5 +/- 14.4mmHg (P = 0.03) at the end of IPR treatment. No adverse events were identified with use of the IPR device.CONCLUSION IPR may be useful in treating intraoperative hypotension without additional fluid or vasopressor therapy. No significant adverse events were observed. On the basis of this phase II pilot study, a larger study is justified.

Takayuki Baba Nafees Baig Pejman Bakhtiari Lelio Baldeschi Adiel barak Yavuz Basterzi Maurizio Battaglia Parodi Paul E. Beaumont Ralph Becker Matthias Becker Phillip Bedggood David Beebe Michael Belkin Guy Ben Simon Eckart Bertelmann Cagri Besirli David Birch Andrea Birnbaum Norman Blair Marcus Blum Daniel Bohringer Silvia Bopp Puran Bora Vincent Borderie Maria Borrelli Mike Boulton David Boyer Curtis Brandt Andreas Bringmann Alain Bron Anne Brooks Jens Buehren Beatrix Buentello-Volante Bang Bui Catey Bunce

Background: Non human primates develop cardiovascular disease over decades. Whether the progression of vascular dysfunction with age is like that observed in humans is unclear. We hypothesize that, like humans, monkeys show age-related reductions in flow-mediated dilation (FMD, an index of endothelium-dependent vascular reactivity) and increases in pulse-wave velocity (PWV, an index of aortic stiffness). We also explored a potential relationship between the age-related vascular effects and circulating biomarkers of endothelial health, endothelial microparticles (EMP) and endothelial progenitor cells (EPC). Methods and Results: In M. fascicularis monkeys (N=21, 14 males and 7 females, 6 to 25 years of age), blood was sampled for EPC and EMP that were measured using flow cytometry. Monkeys were then sedated (midazolam + torbugesic) and baseline femoral artery diameter (4mm segment) was measured by ultrasonography. FMD was calculated as the peak %change from baseline diameter following a 5-minute cessation of blood flow below the knee. PWV was calculated using a modified SphygmoCor program and pulse waves from the radial and femoral arteries. FMD and PWV ranged from 6 to 33% and from 3 to 7 m/s, respectively, and multiple samplings showed high reproducibility up to 4 months (inter-assay variation <5%). FMD negatively (r=-0.94, p<0.0001), while PWV positively (r=0.60, p<0.002) correlated with age in these monkeys. Numbers of EPC (CD45- CD31+ CD34+ VEGFR2+) and EMP [CD45- CD42a- CD54(ICAM-1)+, CD45- CD42a- CD105(endoglin)+, and CD45- CD42a- CD144(VE-cadherin)+] were highly variable between individuals. Neither the EPC nor any of the EMPs significantly correlated with the age or age-related changes in FMD or PWV. Significance = p<0.05. Conclusion: For the first time in non-human primates, we established two non-invasive, clinically-relevant assessments of vascular function, FMD and PWV. Like humans, monkeys show age-related reductions in endothelium-dependent vascular reactivity and increases in aortic stiffness. The circulating numbers of EMP and EPC, independent of the chronic, age-related changes in FMD and PWV, may better serve as biomarkers of acute changes in vascular health associated with disease or therapeutic interventions.

A 3-amino-4-substituted pyrrolidine series of dipeptidyl peptidase IV (DPP-4) inhibitors was rapidly developed into a candidate series by identification of a polar valerolactam replacement for the lipophilic 2,4,5-trifluorophenyl pharmacophore. The addition of a gem-difluoro substituent to the lactam improved overall DPP-4 inhibition and an efficient asymmetric route to 3,4-diaminopyrrolidines was developed. Advanced profiling of a subset of analogs identified 5o with an acceptable human DPP-4 inhibition profile based on a rat PK/PD model and a projected human dose that was suitable for clinical development.

BACKGROUND:Living liver donation is becoming a more common means to treat patients with liver failure because of a shortage of cadaveric organs and tissues. There is a potential for morbidity and mortality, however, in patients who donate a portion of their liver. The purpose of this study is to identify anesthetic complications and morbidity resulting from living liver donor surgery. PATIENTS AND METHODS:The anesthetic records of all patients who donated a segment of their liver between January 1997 and January 2006 at University of Minnesota Medical Center-Fairview were retrospectively reviewed. The surgical and anesthesia time, blood loss, hospitalization length, complications, morbidity, and mortality were recorded. Data were reported as absolute values, mean ± SD, or percentage. Significance (P < 0.05) was determined using Student's paired t tests. RESULTS:Seventy-four patients (34 male, 40 female, mean age = 35.5 ± 9.8 years) donated a portion of their liver and were reviewed in the study. Fifty-seven patients (77%) donated the right hepatic lobe, while 17 (23%) donated a left hepatic segment. The average surgical time for all patients was 7.8 ± 1.5 hours, the anesthesia time was 9.0 ± 1.3 hours, and the blood loss was 423 ± 253 ml. Forty-six patients (62.2%) received autologous blood either from a cell saver or at the end of surgery following acute, normovolemic hemodilution, but none required an allogenic transfusion. Two patients were admitted to the intensive care unit due to respiratory depression. Both patients donated their right hepatic lobe. One required reintubation in the recovery room and remained intubated overnight. The other was extubated but required observation in the intensive care unit for a low respiratory rate. Twelve patients (16.2%) had complaints of nausea, and two reported nausea with vomiting during their hospital stay. There were four patients who developed complications related to positioning during the surgery: Two patients complained of numbness and tingling in the hands which resolved within two days, one patient reported a blister on the hand, and one patient complained of right elbow pain that resolved quickly. Postoperative hospitalization averaged 7.4 ± 1.5 days. There was no patient mortality. DISCUSSION:Living liver donation can be performed with low morbidity. However, postoperative respiratory depression is a concern and is perhaps due to altered metabolism of administered narcotics and anesthetic agents.

Background: Rosiglitazone, 6 hours after dosing, rapidly increases endothelial-dependent flow mediated dilation (FMD) in subjects with healthy endothelium. Whether this acute improvement in FMD occurs in the presence of endothelial dysfunction is unknown. We test the hypothesis that rosiglitazone acutely improves FMD in senescent monkeys with endothelial dysfunction and that the improvement coincides with favorable changes in circulating biomarkers of endothelial health, endothelial progenitor cells (EPC) and endothelial microparticles (EMP). Euglycemic monkeys were used to avoid rosiglitazone’s glucose-lowering effects. Methods and Results: In a crossover design, 6 fasted M. fascicularis monkeys (5M/1F; 17 ± 1 yr) were dosed ≥2 weeks apart with vehicle or rosiglitazone at a dose (1 mg/kg, PO) that did not affect baseline hemodynamics, fasting plasma glucose (65 ± 6 mg/dL), insulin (10 ± 3 µlU/mL), total cholesterol (79 ± 7 mg/dL) or triglycerides (59 ± 6 mg/dL). EPC and EMP were sampled 6 h after dosing and measured by flow cytometry. Monkeys were then sedated (midazolam + torbugesic) and baseline femoral artery diameter (4mm segment) measured by ultrasonography. FMD was calculated as the peak %change from baseline following a 5-minute cessation of blood flow below the knee. FMD was lower in these monkeys (17.6 ± 1.3%) vs. young adults (≥25%). Rosiglitazone (vs. vehicle) increased (p<0.01) FMD to 21.3 ± 1.6% (vs.16.9 ± 1.4%) without affecting baseline diameter (1.52 ± 0.04 vs.1.51 ± 0.04 mm). Rosiglitazone (vs. vehicle) increased (p<0.01) EPC [CD45- CD31+ CD34+ VEGFR2+] to 7116 ± 1296 (vs. 4786 ± 1102) cells/ml and decreased (p<0.04) EMP [CD45- CD42a- CD54(ICAM-1)+] to 26669 ± 11112 (vs. 62245 ± 9772) EMP/ml; EMP [CD45- CD42a- CD105(endoglin)+] and EMP [CD45- CD42a- CD144(VE-cadherin)+] also trended lower. (Mean ± SEM; paired t-test). Conclusion: Rosiglitazone acutely improves the endothelial dysfunction in senescent monkeys. This increased FMD is independent of its metabolic effects on glucose and lipids and coincides with stimulation of EPC and with suppression of EMP linked to endothelial cell adhesion and potentially apoptosis. Whether these EPC and EMP changes directly contribute to the enhanced endothelial function warrants further study.

A promising area of novel anti-diabetic therapy involves identification of small molecule activators of the glucokinase enzyme to reduce blood glucose and normalize glucose stimulated insulin secretion. Herein, we report the identification and optimization of a series of 4-sulfonyl-2-pyridone activators. The activators were evaluated for in vitro biochemical activation and pharmacokinetic properties. As part of these efforts, a unique metabolic liability of the 4-sulfonyl-2-pyridone ring system was identified wherein this heterocycle readily undergoes conjugation with glutathione under non-enzymatic conditions.

A highly ligand efficient lead molecule was rapidly developed into a DPP-IV selective candidate series using focused small library synthesis. A significant hurdle for series advancement was genetic safety since some agents in this series impaired chromosome division that was detected using the in vitro micronucleus assay. A recently developed high-throughput imaging-based in vitro micronucleus assay enabled the identification of chemical space with a low probability of micronucleus activity. Advanced profiling of a subset within this space identified a compound with a clean safety profile, an acceptable human DPP-IV inhibition profile based on the rat PK/PD model and a projected human dose that was suitable for clinical development.