Publications by authors named "Jean Chan"

Genetic medicines, including CRISPR/Cas technologies, extend tremendous promise for addressing unmet medical need in inherited retinal disorders and other indications; however, there remain challenges for the development of therapeutics. Herein, we evaluate genome editing by engineered Cas9 ribonucleoproteins (eRNP) in vivo via subretinal administration using mouse and pig animal models. Subretinal administration of adenine base editor and double strand break-inducing Cas9 nuclease eRNPs mediate genome editing in both species.

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Background: Adrenal insufficiency in patients with classic 21-hydroxylase deficiency congenital adrenal hyperplasia (CAH) is treated with glucocorticoid replacement therapy. Control of adrenal-derived androgen excess usually requires supraphysiologic glucocorticoid dosing, which predisposes patients to glucocorticoid-related complications. Crinecerfont, an oral corticotropin-releasing factor type 1 receptor antagonist, lowered androstenedione levels in phase 2 trials involving patients with CAH.

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Background: Children with classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency require treatment with glucocorticoids, usually at supraphysiologic doses, to address cortisol insufficiency and reduce excess adrenal androgens. However, such treatment confers a predisposition to glucocorticoid-related complications. In 2-week phase 2 trials, patients with CAH who received crinecerfont, a new oral corticotropin-releasing factor type 1 receptor antagonist, had decreases in androstenedione levels.

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Context: Crinecerfont, a corticotropin-releasing factor type 1 receptor antagonist, has been shown to reduce elevated adrenal androgens and precursors in adults with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD), a rare autosomal recessive disorder characterized by cortisol deficiency and androgen excess due to elevated adrenocorticotropin.

Objective: To evaluate the safety, tolerability, and efficacy of crinecerfont in adolescents with 21OHD CAH.

Methods: This was an open-label, phase 2 study (NCT04045145) at 4 centers in the United States.

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Clinically significant portal hypertension (CSPH), defined as hepatic venous pressure gradient (HVPG) ≥ 10 mm Hg, identifies patients with compensated cirrhosis at a high risk of decompensation. However, HVPG is an invasive and nuanced method. The ANTICIPATE models, which include liver stiffness measurements by transient elastography (TE) and platelet count ± body mass index, are robust noninvasive surrogates of CSPH but required external validation in patients with nonalcoholic steatohepatitis (NASH) cirrhosis.

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Context: Classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21OHD) is characterized by impaired cortisol synthesis and excess androgen production. Corticotropin-releasing factor type 1 receptor (CRF1R) antagonism may decrease adrenal androgen production.

Objective: This work aimed to evaluate the safety, tolerability, and efficacy of crinecerfont (NBI-74788), a selective CRF1R antagonist, in 21OHD.

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Despite achieving sustained virologic response (SVR) to hepatitis C virus (HCV) therapy, there remains a post liver transplantation population with advanced fibrosis/cirrhosis. Emricasan is an orally active, pan-caspase inhibitor that suppresses apoptosis and inflammation, potentially decreasing hepatic inflammation and fibrosis. We aimed to determine the safety and efficacy of emricasan (IDN-6556-07) in a double-blind, randomized, placebo-controlled, multicenter study in reducing or preventing the progression of hepatic fibrosis in HCV liver transplant recipients with residual fibrosis or cirrhosis after achieving SVR.

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Background & Aims: Non-alcoholic steatohepatitis is a leading cause of end-stage liver disease. Hepatic steatosis and lipotoxicity cause chronic necroinflammation and direct hepatocellular injury resulting in cirrhosis, end-stage liver disease and hepatocellular carcinoma. Emricasan is a pan-caspase inhibitor that inhibits excessive apoptosis and inflammation; it has also been shown to decrease portal pressure and improve synthetic function in mice with carbon tetrachloride-induced cirrhosis.

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Background & Aims: Non-alcoholic steatohepatitis (NASH) is characterized by hepatocyte steatosis, ballooning, and lobular inflammation which may lead to fibrosis. Lipotoxicity activates caspases, which cause apoptosis and inflammatory cytokine (IL-1β and IL-18) production. Emricasan is a pan-caspase inhibitor that decreases serum aminotransferases and caspase activation in patients with NASH.

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Background & Aims: Emricasan, an oral pan-caspase inhibitor, decreased portal pressure in experimental cirrhosis and in an open-label study in patients with cirrhosis and severe portal hypertension, defined as a hepatic venous pressure gradient (HVPG) ≥12 mmHg. We aimed to confirm these results in a placebo-controlled study in patients with non-alcoholic steatohepatitis (NASH)-related cirrhosis.

Methods: We performed a multicenter double-blinded study, randomizing 263 patients with NASH-related cirrhosis and baseline HVPG ≥12 mmHg to twice daily oral emricasan 5 mg, 25 mg, 50 mg or placebo in a 1:1:1:1 ratio for up to 48 weeks.

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Background: Lipotoxicity leading to excessive caspase-mediated apoptosis and inflammation is believed to drive liver damage in NAFLD. Emricasan is a pan-caspase inhibitor that decreased serum ALT and apoptotic and inflammatory markers in subjects with chronic hepatitis.

Aims: To assess whether 28 days of emricasan would reduce elevated levels of serum ALT, AST, cleaved cytokeratin-18, full-length cytokeratin-18, and caspase 3/7 in subjects with NAFLD and raised aminotransferases.

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Rational design of drug-like small-molecule ligands based on structural information of proteins remains a significant challenge in chemical biology. In particular, designs targeting protein-protein interfaces have met little success given the dynamic nature of the protein surfaces. Herein, we utilized the structure of a small-molecule ligand in complex with Toll-like receptor 8 (TLR8) as a model system due to TLR8's clinical relevance.

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Caspases play a central role in apoptosis, inflammation, and fibrosis. They produce hemodynamically active, proinflammatory microparticles that cause intrahepatic inflammation, vasoconstriction, and extrahepatic splanchnic vasodilation. Emricasan is a pan-caspase inhibitor that lowers portal hypertension (PH) and improves survival in murine models of cirrhosis.

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Background & Aims: Caspase-mediated apoptosis and inflammation contribute to progression of liver disease. Emricasan is a pan-caspase inhibitor that reduced serum markers of apoptosis and liver inflammation in patients with hepatitis C and non-alcoholic steatohepatitis (NASH).

Methods: We performed a multicenter study of 86 patients with cirrhosis (Child-Pugh class A or B; mean score, 6.

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Objective: Recombinant human leptin (metreleptin) improves glycaemia and hypertriglyceridaemia in patients with generalized lipodystrophy; antibody development with in vitro neutralizing activity has been reported. We aimed to characterize antimetreleptin antibody development, including in vitro neutralizing activity.

Design: Two randomized controlled studies in patients with obesity (twice-daily metreleptin ± pramlintide for 20-52 weeks; 2006-2009); two long-term, open-label studies in patients with lipodystrophy (once-daily or twice-daily metreleptin for 2 months to 12·3 years; 2000-2014).

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Acquired generalized lipodystrophy (AGL) is a rare disease thought to result from autoimmune destruction of adipose tissue. Peripheral T-cell lymphoma (PTCL) has been reported in two AGL patients. We report five additional cases of lymphoma in AGL, and analyze the role of underlying autoimmunity and recombinant human leptin (metreleptin) replacement in lymphoma development.

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Objective: To evaluate the long-term clinical effect of treatment with metreleptin (an analogue of human leptin) on glycemic and lipid abnormalities and markers of hepatic steatosis in patients with inherited or acquired lipodystrophy.

Methods: Fifty-five patients (36 with generalized lipodystrophy and 19 with partial lipodystrophy) with at least 1 of 3 metabolic abnormalities (diabetes mellitus, fasting triglyceride level ≥200 mg/dL, and insulin resistance) and low leptin levels received subcutaneous injections of metreleptin once or twice daily in an ongoing clinical trial at the National Institutes of Health.

Results: At baseline, hemoglobin A1c-8.

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Background: Cricoid pressure is a routine component of rapid sequence induction and is designed to reduce the risk of reflux and its associated morbidity. Recent studies have raised questions regarding the efficacy of cricoid pressure in terms of changes in the pharyngeal and esophageal anatomy.

Objective: This current descriptive study was designed to observe the anatomical effect of cricoid pressure on the occlusion of esophageal lumen in conscious volunteers using magnetic resonance imaging (MRI).

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Glucocorticoids are widely used to treat patients with autoimmune diseases such as systemic lupus erythematosus (SLE). However, regimens used to treat many such conditions cannot maintain disease control in the majority of SLE patients and more aggressive approaches such as high-dose methylprednisolone pulse therapy are used to provide transient reductions in disease activity. The primary anti-inflammatory mechanism of glucocorticoids is thought to be NF-kappaB inhibition.

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Objective: To review the initial clinical manifestations of congenital and acquired lipodystrophy syndromes, discuss novel classifications associated with genetic mutations, and assess currently available therapeutic options for patients with lipodystrophy.

Methods: This review is the result of the authors' collective clinical experience and a comprehensive MEDLINE literature search on the English-language literature published between January 1966 and October 2009 on "lipodystrophy." This review focuses primarily on severe dystrophy not related to human immunodeficiency virus (HIV) infection, in light of the additional scope required to cover HIV-related lipodystrophy.

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Objective: To review evidence supporting the hypothesis that metabolic manifestations of lipodystrophy result from leptin deficiency and that leptin replacement may be a viable treatment for generalized lipodystrophy.

Methods: This review results from the authors' collective clinical experience and a comprehensive MEDLINE search of the English-language literature (1998 to 2009) on "leptin and lipodystrophy."

Results: Severe lipodystrophy syndromes are characterized by loss of subcutaneous adipose tissue and thus a relative deficiency of the adipocyte-secreted hormone leptin.

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The discovery of leptin in 1994 was a seminal event in obesity research. It helped to establish that body weight is tightly regulated by a complex neurohormonal feedback system and that obesity should be viewed as a disorder with a strong biological basis rather than simply the result of poor lifestyle choices and lack of willpower.Leptin, secreted from adipocytes, acts as a prototypic long-term (tonic) adiposity signal.

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