Efficient site-specific integration of large genes in mammalian cells via continuously evolved recombinases and prime editing.

Methods for the targeted integration of genes in mammalian genomes suffer from low programmability, low efficiencies or low specificities. Here we show that phage-assisted continuous evolution enhances prime-editing-assisted site-specific integrase gene editing (PASSIGE), which couples the programmability of prime editing with the ability of recombinases to precisely integrate large DNA cargoes exceeding 10 kilobases. Evolved and engineered Bxb1 recombinase variants (evoBxb1 and eeBxb1) mediated up to 60% donor integration (3.

Phage-assisted evolution of highly active cytosine base editors with enhanced selectivity and minimal sequence context preference.

TadA-derived cytosine base editors (TadCBEs) enable programmable C•G-to-T•A editing while retaining the small size, high on-target activity, and low off-target activity of TadA deaminases. Existing TadCBEs, however, exhibit residual A•T-to-G•C editing at certain positions and lower editing efficiencies at some sequence contexts and with non-SpCas9 targeting domains. To address these limitations, we use phage-assisted evolution to evolve CBE6s from a TadA-mediated dual cytosine and adenine base editor, discovering mutations at N46 and Y73 in TadA that prevent A•T-to-G•C editing and improve C•G-to-T•A editing with expanded sequence-context compatibility, respectively.

Evaluation of appendectomy as a potential risk factor for immune checkpoint inhibitor-associated enterocolitis.

The relationship between appendectomy and immune checkpoint inhibitor (ICI) enterocolitis was explored. Patients who began ICIs between July 2010 and September 2020 (n = 10,907) were included. The exposure group included patients with evidence of appendectomy prior to ICIs in operative notes (n = 380).

The evolution of pituitary cysts in growth hormone-treated children.

Objectives: We have previously shown that pituitary cysts may affect growth hormone secretion. This study sought to determine cyst evolution during growth hormone treatment in children.

Methods: Forty-nine patients with short stature, a pituitary cyst, and at least two brain MRI scans were included.

Evolution of an adenine base editor into a small, efficient cytosine base editor with low off-target activity.

Cytosine base editors (CBEs) are larger and can suffer from higher off-target activity or lower on-target editing efficiency than current adenine base editors (ABEs). To develop a CBE that retains the small size, low off-target activity and high on-target activity of current ABEs, we evolved the highly active deoxyadenosine deaminase TadA-8e to perform cytidine deamination using phage-assisted continuous evolution. Evolved TadA cytidine deaminases contain mutations at DNA-binding residues that alter enzyme selectivity to strongly favor deoxycytidine over deoxyadenosine deamination.

Feeding intolerance in critically ill patients with COVID-19.

Background & Aims: Early reports suggest significant difficulty with enteral feeding in critically ill COVID-19 patients. This study aimed to characterize the prevalence, clinical manifestations, and outcomes of feeding intolerance in critically ill patients with COVID-19.

Methods: We examined 323 adult patients with COVID-19 admitted to the intensive care units (ICUs) of Massachusetts General Hospital between March 11 and June 28, 2020 who received enteral nutrition.

SynNotch-CAR T cells overcome challenges of specificity, heterogeneity, and persistence in treating glioblastoma.

Treatment of solid cancers with chimeric antigen receptor (CAR) T cells is plagued by the lack of ideal target antigens that are both absolutely tumor specific and homogeneously expressed. We show that multi-antigen prime-and-kill recognition circuits provide flexibility and precision to overcome these challenges in the context of glioblastoma. A synNotch receptor that recognizes a specific priming antigen, such as the heterogeneous but tumor-specific glioblastoma neoantigen epidermal growth factor receptor splice variant III (EGFRvIII) or the central nervous system (CNS) tissue-specific antigen myelin oligodendrocyte glycoprotein (MOG), can be used to locally induce expression of a CAR.

Association Between Systemic Corticosteroid Treatment for Cutaneous Immune-Related Adverse Events and Survival Outcomes in Patients With Advanced Cancer.

This cohort study investigates the association of systemic corticosteroid exposures with infectious complications and survival outcomes among patients with a cutaneous immune-related adverse event.

Patterns of Cutaneous and Noncutaneous Immune-Related Adverse Events Among Patients With Advanced Cancer.

Importance: Cutaneous immune-related adverse events (cirAEs) are some of the earliest toxic reactions to emerge following immune-checkpoint inhibitor (ICI) initiation. As an early indicator of robust inflammatory response, cirAEs may be associated with patterns of immune-mediated toxic effects, but associations between these events and noncutaneous immune-related adverse events (irAEs) remain underexplored.

Objectives: To characterize patterns of cirAEs and irAEs across care settings and examine associations between the features of first cirAE, overall irAE risk, and risk of specific irAE subtypes.

Effect of dermatological consultation on survival in patients with checkpoint inhibitor-associated cutaneous toxicity.

Background: Cutaneous immune-related adverse events (cirAEs) are a common side-effect of immune checkpoint inhibitors (ICIs). However, prior work examining these toxicities in detail has considered only the fraction of events evaluated by dermatologists. Associations between dermatology referral, cirAE treatment and survival outcomes remain underexplored across care settings.

The prevalence and volumetry of pituitary cysts in children with growth hormone deficiency and idiopathic short stature.

Background Pituitary cysts have been speculated to cause endocrinopathies. We sought to describe the prevalence and volumetry of pituitary cysts in patients with growth hormone deficiency (GHD) and idiopathic short stature (ISS). Methods Six hundred and eighteen children evaluated for growth failure at the Division of Pediatric Endocrinology at New York Medical College between the years 2002 and 2012, who underwent GH stimulation testing and had a brain magnetic resonance imaging (MRI) prior to initiating GH treatment were randomly selected to be a part of this study.

Brain and high metabolic rate organ mass: contributions to resting energy expenditure beyond fat-free mass.

Background: The degree to which interindividual variation in the mass of select high metabolic rate organs (HMROs) mediates variability in resting energy expenditure (REE) is unknown.

Objective: The objective was to investigate how much REE variability is explained by differences in HMRO mass in adults and whether age, sex, and race independently predict REE after adjustment for HMRO.

Design: A cross-sectional evaluation of 55 women [30 African Americans aged 48.

Smaller organ mass with greater age, except for heart.

Autopsy/cadaver data indicate that many organs and tissues are smaller in the elderly compared with young adults; however, in vivo data are lacking. The aim of this study was to determine whether the mass of specific high-metabolic-rate organs is different with increasing age, using MRI. Seventy-five healthy women (41 African-Americans and 34 Caucasians, age range 19-88 yr) and 36 men (8 African-Americans and 28 Caucasians, age range 19-84 yr) were studied.

Small organs with a high metabolic rate explain lower resting energy expenditure in African American than in white adults.

Background: African Americans have a lower resting energy expenditure (REE) relative to fat-free mass (FFM) than do whites. Whether the composition of FFM at the organ-tissue level differs between African Americans and whites and, if so, whether that difference could account for differences by race in REE are unknown.

Objective: The objectives were to quantify FFM in vivo in women and men at the organ-tissue level and to ascertain whether the mass of specific high-metabolic-rate organs and tissues differs between African Americans and whites and, if so, whether that difference can account for differences in REE.

Larger mass of high-metabolic-rate organs does not explain higher resting energy expenditure in children.

Background: Children have a high resting energy expenditure (REE) relative to their body weight. The decline in REE during growth may be due to changes in body composition or to changes in the metabolic rate of individual organs and tissues.

Objectives: The goals were to quantify body-composition components in children at the organ-tissue level in vivo and to determine whether the observed masses 1) account for the elevated REE in children and 2) account, when combined with specific organ-tissue metabolic constants, for children's REE.

Smaller organ tissue mass in the elderly fails to explain lower resting metabolic rate.

We previously reported our in vivo prediction of whole body resting energy expenditure (REE) using magnetic resonance imaging and echocardiography-derived organ volumes combined with published organ tissue metabolic rates. The models, developed in young healthy persons from predicted and measured variables, were highly correlated (e.g.

Reliability of enhanced gated SPECT in assessing wall motion of severely hypoperfused myocardium: echocardiographic validation.

Background: A method has been described for improving myocardial visibility on 99mTc-labeled sestamibi gated tomograms, even in the presence of severe hypoperfusion. It is essential to verify that images transformed in this manner truly depict the myocardium and do not contain image artifacts. This is especially important if transformed images are to be used to aid in the discernment of regional wall-motion abnormalities.

Organ-tissue mass measurement allows modeling of REE and metabolically active tissue mass.

Investigators have expressed interest in the associations between resting energy expenditure (REE) and body mass for over a century. Traditionally, descriptive models using regression analysis are applied, linking REE with metabolically active compartments such as body cell mass (BCM) and fat-free body mass (FFM). Recently developed whole body magnetic resonance imaging (MRI) and echocardiography methods now allow estimation of all major organs and tissue volumes in vivo.

Diagnosis of pericardial effusion and its effects on ventricular function using gated Tc-99m sestamibi perfusion SPECT.

Pericardial effusion is a common disorder associated with a variety of medical disorders. Diagnostic methods of choice include echocardiography, CT, and MRI. However, diagnosing pericardial effusion with radionuclides is uncommon.

Subaortic septal bulge simulates hypertrophic cardiomyopathy by angulation of the septum with age, independent of focal hypertrophy. An echocardiographic study.

Focal hypertrophy of the basal anterior septum occurs not infrequently in elderly patients and is considered by some to be a significant form of hypertrophic cardiomyopathy; others consider it to be an unimportant anatomic variant associated with an angulated septum, called a septal bulge (SB). We analyzed 94 cases of SB collected prospectively and compared them with 88 patients with extensive hypertrophic cardiomyopathy (HCM), 20 patients with hypertrophic cardiomyopathy limited to the entire septum (ASH), and 20 age-matched controls. The SB cases were also divided into three groups, with marked, moderate, or no basal septal hypertrophy associated with the occurrence of an SB.