Essential transcription factors for induced neuron differentiation.

Neurogenins are proneural transcription factors required to specify neuronal identity. Their overexpression in human pluripotent stem cells rapidly produces cortical-like neurons with spiking activity and, because of this, they have been widely adopted for human neuron disease models. However, we do not fully understand the key downstream regulatory effectors responsible for driving neural differentiation. Here, using inducible expression of NEUROG1 and NEUROG2, we identify transcription factors (TFs) required for directed neuronal differentiation by combining expression and chromatin accessibility analyses with a pooled in vitro CRISPR-Cas9 screen targeting all ~1900 TFs in the human genome. The loss of one of these essential TFs (ZBTB18) yields few MAP2-positive neurons. Differentiated ZBTB18-null cells have radically altered gene expression, leading to cytoskeletal defects and stunted neurites and spines. In addition to identifying key downstream TFs for neuronal differentiation, our work develops an integrative multi-omics and TFome-wide perturbation platform to rapidly characterize essential TFs for the differentiation of any human cell type.

Multiplexed detection of proteins, transcriptomes, clonotypes and CRISPR perturbations in single cells.

Multimodal single-cell assays provide high-resolution snapshots of complex cell populations, but are mostly limited to transcriptome plus an additional modality. Here, we describe expanded CRISPR-compatible cellular indexing of transcriptomes and epitopes by sequencing (ECCITE-seq) for the high-throughput characterization of at least five modalities of information from each single cell. We demonstrate application of ECCITE-seq to multimodal CRISPR screens with robust direct single-guide RNA capture and to clonotype-aware multimodal phenotyping of cancer samples.

Short-term and midterm survival of ruptured abdominal aortic aneurysms in the contemporary endovascular era.

OBJECTIVE: Endovascular aneurysm repair (EVAR) has been shown to reduce mortality in the emergent repair of ruptured abdominal aortic aneurysms (AAAs). However, long-term survival data for this group of patients are lacking with contemporary endovascular endografts. The purpose of this study was to evaluate both 30-day mortality rates and 1-year survival in patients undergoing emergent EVAR in a 43-facility hospital system with a quaternary referral center with an established ruptured aneurysm protocol. METHODS: Retrospective analysis of patients captured prospectively in an Institutional Review Board-approved registry for patients treated emergently for AAA were reviewed between 2012 and 2017 was conducted. Primary outcome measures were 30-day mortality and 1-year survival for the entire group as well as for symptomatic and ruptured aneurysms. Data were analyzed using logistic regression survival curves, and a log-rank test was performed to compare survival between open and endovascular repair. Patients were evaluated on an intent-to-treat basis, and outcomes were evaluated in a multivariate model. RESULTS: A total of 249 patients were referred as part of the protocol. Of these, 102 (41%) were treated emergently. Kaplan-Meier estimates of 30-day and 1-year survival were 64% and 53% for all patients, 58% and 46% for ruptured patients, and 86% and 81% for symptomatic patients. EVAR resulted in improved 30-day survival (64% vs 31%; odds ratio, 4.0; P = .03) and 1-year survival (40% vs 23%; odds ratio, 2.3; P = .4) over open repair. Significant predictors for 30-day mortality included hypotension (P = .0003), blood transfusion (P < .0001), length of stay (P = .0005), extravasation (P = .01), preoperative cardiopulmonary resuscitation (P = .04), open repair (P = .007), aortouni-iliac reconstruction (P = .008), and abdominal compartment syndrome (P = .007). Significant predictors for 1-year mortality included advanced age (P = .04), hypotension (P = .01), blood transfusion (P = .006), extravasation (P = .03), reintubation (P = .03), and abdominal compartment syndrome (P = .03). There were no differences in outcomes based on race, gender, or outside transfer. Peripheral arterial disease (P = .04), hypertension (P = .04), coronary artery disease (P = .03), and familial history of aneurysms (P = .05) were related to increased 30-day mortality. Peripheral arterial disease (P = .06) and coronary artery disease (P = .07) were nearly significant, with increased 1-year mortality. CONCLUSIONS: EVAR is associated with improved survival compared with open repair in patients requiring emergent AAA repair. However, in the first year, there is a significant risk of death based on initial presentation as well as underlying comorbidities. To improve long-term survival, aggressive medical management and medical surveillance are warranted.

Ethnic disparities in outcomes of patients with complicated type B aortic dissection.

OBJECTIVE: The objective of this study was to evaluate the difference in outcomes after endovascular intervention in patients with complicated type B aortic dissection (TBAD) based on ethnicity and blood pressure control. METHODS: Between 2012 and 2016, there were 126 patients who underwent endovascular procedures for complicated TBAD at a single-institution quaternary referral center. Patients self-identified as African American (n = 53), white (n = 70), and Asian (n = 3). African American and white patients were compared on a number of variables, including age, ethnicity, insurance type, blood pressure, comorbidities, number of previous interventions, and number of antihypertension medications they were taking before intervention. Primary outcomes were survival and need for reintervention. RESULTS: Kaplan-Meier estimates for survival for African Americans vs whites were 94% vs 89%, 91% vs 83%, 89% vs 79%, and 89% vs 76% at 30 days, 1 year, 3 years, and 5 years, respectively (P = .05). African Americans were younger overall (52.5 ± 11 years) vs whites (63.7 ± 14.7 years; P < .0001). African Americans required a significantly greater number of reinterventions (P = .007). They also had higher rates of chronic kidney disease (P = .01), smoking (P = .03), and cocaine use (P = .02) and were more likely to be on Medicaid (P = .02). Hypertension was poorly controlled in both groups, with the percentage of patients with uncontrolled hypertension (systolic >140 mm Hg) preoperatively, postoperatively, and 30 days after intervention at 32%, 32%, and 39%. There was no significant difference between the cohorts in uncontrolled hypertension preoperatively (P = .39) or postoperatively (P = .63). However, more African Americans had uncontrolled hypertension at 30 days (African Americans, 49%; whites, 31%; odds ratio, 2.1; P = .09). African Americans were taking a greater number of antihypertension medications at presentation than whites (P = .01) and specifically had higher use rates of beta blockers (P = .02), diuretics (P = .02), and angiotensin-converting enzyme inhibitors (P = .04). CONCLUSIONS: African Americans with TBAD present at a younger age than their white counterparts do and have a survival advantage up to at least 5 years. However, African Americans have a higher rate of reintervention that is probably associated with poor blood pressure control despite taking more antihypertension medications both before and after the repair. It appears that optimal medical therapy is difficult to achieve in all groups. More aggressive medical management is needed, particularly more so in African Americans, which may in turn decrease the number of interventions and potentially improve long-term survival.

Successful Repair of Acute Type B and Retrograde Type A Aortic Dissection With Kidney Ischemia.

Acute dissection of thoracic aorta carries a risk of renal ischemia followed by the development of a kidney failure. The optimal surgical and nonsurgical management of these patients, timing of intervention, and the factors predicting renal recovery are not well delineated and remain controversial. We present a case of acute type B thoracic aortic dissection with left kidney ischemia. Evaluation of renal function was performed by the means of internationally accepted Risk, Injury, Failure, Loss of kidney function, End stage kidney disease and Acute Kidney Injury Network classifications for acute kidney injury, renal duplex sonography, and intravascular ultrasound that demonstrated left renal artery dissection with a flap completely compressing the true lumen. The patient underwent thoracic endovascular aortic repair and left renal artery stent and recovered well. Six months later, at the follow-up visit, retrograde type A aortic dissection was found, which was successfully repaired. Reversal of renal ischemia after aortic dissection depends on the precise assessment of renal function and prompt intervention.

The perfused, pulseless supracondylar humeral fracture: intermediate-term follow-up of vascular status and function.

BACKGROUND: This study provides intermediate-term follow-up data on the vascular status of a cohort of children with a perfused, pulseless supracondylar humeral fracture who were managed with closed reduction, percutaneous pinning, and observation. METHODS: Pediatric patients who sustained a perfused, pulseless supracondylar humeral fracture in the period from 2007 to 2011 and who had at least six months of clinical follow-up were identified and returned for evaluation. The primary outcome was vascular status as indicated by palpation of the radial pulse, the wrist brachial index, and arterial patency on duplex ultrasound. Secondary outcomes included functional parameters assessed with the Pediatric Outcomes Data Collection Instrument (PODCI), arm circumference, arm length, elbow motion, neurologic findings, muscle endurance, grip strength, and intolerance to cold. RESULTS: Follow-up data were obtained for twenty of thirty-six patients with a Gartland type-III fracture who had been managed with closed reduction and percutaneous pinning. Five patients had a return of a palpable pulse in the operating room after closed reduction and percutaneous pinning. All twenty had a palpable radial pulse at the time of the latest follow-up, and all nerve palsies resolved. Duplex ultrasound performed at the time of follow-up showed that fourteen patients had a patent brachial artery, five had brachial artery occlusion with large collateral vessels, and one had severe arterial stenosis. All fourteen patients with a patent brachial artery, two of the five with an occluded brachial artery, and the patient with a stenotic brachial artery had a normal wrist brachial index. Three patients with an occluded brachial artery had an abnormal wrist brachial index (0.73, 0.71, and 0.80). No differences between the injured and uninjured sides were observed with regard to arm circumference, arm length, elbow motion, muscle endurance, or grip strength. Thirteen of the twenty patients had higher functioning in all domains of the PODCI questionnaire compared with the general population. Two patients (one with an occluded artery and one with a patent artery) had lower values on the global functioning score. CONCLUSIONS: After an average of twenty months of follow-up, children with a perfused, pulseless supracondylar humeral fracture that had been treated with closed reduction, percutaneous pinning, and observation demonstrated a palpable distal radial pulse, normal growth of the arm, and good/excellent functional outcomes, although five of the twenty patients had an occluded brachial artery. LEVEL OF EVIDENCE: Therapeutic level IV. See Instructions for Authors for a complete description of levels of evidence.

Current status of endovascular aneurysm repair: 20 years of learning.

Parodi first introduced endovascular aneurysm repair (EVAR) in 1991 and since that time it has been shown to have a lower 30-day morbididty and mortality compared to open surgery. Anatomic constraints governed by the need for adequate access vessels, and sufficient proximal and distal landing zones, as well as the need for long-term surveillance, have been the main limitations of this technology. Anatomic factors were initially estimated to exclude 40% of patients with abdominal aortic aneurysm (AAA). The rapid extension of EVAR technology has been complimented by improved access to both high-quality imaging modalities and a variety of endografts. These developments have led EVAR to become a more practical alternative for patients with ruptured AAA. Early data in this setting is encouraging with even more profound reductions in morbidity and mortality than seen in the elective repair.

Spontaneous splanchnic dissection: application and timing of therapeutic options.

BACKGROUND: Spontaneous splanchnic dissection (SSD) occurs infrequently and has a poorly defined natural history. Few studies address the application, timing, and consequences of therapeutic options. Our goal was to apply conservative (non-operative) management in the care of each patient, reserving interventions for specific indications that may be predictive of adverse outcomes. METHODS: Between 2003 and 2008, 10 consecutive patients (mean age 54.7-years-old, 70.0% male) presented with 11 SSDs involving either the celiac artery (n = 6), superior mesenteric artery (n = 3), or both (n = 1). Each patient had acute, spontaneous onset of persistent abdominal pain and was diagnosed with SSD following multidetector row computed tomographic angiography (CTA). Non-operative management (anticoagulation, anti-impulse therapy, analgesics, and serial CTA examinations) was initially used in 9 patients. Endovascular (n = 2) or operative (n = 2) intervention was performed either immediately (n = 1) or following failed medical management (n = 3) in 4 patients for specific indications that included persistent symptoms (n = 3), expansion of false lumen (n = 3), and/or radiologic malperfusion (n = 3). RESULTS: All patients were asymptomatic after successful non-operative management or following intervention. No morbidity occurred. Upon complete follow-up (mean 13.4 months, range, 2 to 36 months), all patients remained asymptomatic. Preservation of distal perfusion with either thrombosis or ongoing regression of false lumen was achieved in 5 patients who received only non-operative management and in 4 patients following intervention. A stable chronic dissection was present in 1 patient who had only non-operative management. CONCLUSION: Successful outcomes following SSD may be achieved with either non-operative therapy alone or intervention if persistent symptoms, expansion of false lumen, and/or malperfusion occur. The unpredictable response of the false lumen to conservative management mandates close, long-term follow-up. Endovascular and operative interventions produced similar outcomes in a small number of patients with limited follow-up. Although SSD is currently perceived as rare, the increasing use of CTA may prove that the true incidence has been underestimated.

Endovascular exclusion of mycotic aortic aneurysm.

The presence of prohibitive risk may preclude usual surgical management. Such was the case for a critically ill, 60-year-old woman who presented with concomitant, life-threatening conditions. The patient presented with acute central cord syndrome and lower-extremity paraplegia after completing a 6-week course of intravenous antibiotics for methicillin-sensitive Staphylococcus aureus bacteremia and osteomyelitis of the thoracic spine. Radiologic examination revealed bony destruction of thoracic vertebrae T4 through T6, impingement on the spinal cord and canal by an inflammatory mass, and a separate 2.5-cm mycotic aneurysm of the infrarenal aorta. The clinical and radiologic findings warranted immediate decompression and stabilization of the spinal cord, aneurysmectomy, and vascular reconstruction. However, the severely debilitated patient could not tolerate 2 simultaneous open procedures. She underwent emergent endovascular exclusion of the mycotic aneurysm with a stent-graft, followed immediately by laminectomy and stabilization of the thoracic spine. Intraoperative microbiology specimens showed no growth. The patient was maintained on prophylactic antibiotic therapy for 6 months. Fourteen months postoperatively, her neurologic function was near full recovery, and neither surveillance blood cultures nor radiologic examinations showed a recurrence of infection or aneurysm. Although the long-term outcome of endovascular stent-grafts in the treatment of culture-negative mycotic aneurysms is unknown, the use of these grafts in severely debilitated patients can reduce operative risk and enable recovery in the short term.

Arteriopathy in the high-performance athlete.

Pain occurs frequently in high-performance athletes and is most often due to musculoskeletal injury or strain. However, athletes who participate in sports that require highly frequent, repetitive limb motion can also experience pain from an underlying arteriopathy, which causes exercise-induced ischemia. We reviewed the clinical records and follow-up care of 3 high-performance athletes (mean age, 29.3 yr; range, 16-47 yr) who were admitted consecutively to our institution from January 2002 through May 2003, each with a diagnosis of limb ischemia due to arteriopathy. The study group comprised 3 males: 2 active in competitive baseball (ages, 16 and 19 yr) and a cyclist (age, 47 yr). Provocative testing and radiologic evaluation established the diagnoses. Treatment goals included targeted resection of compressive structures, arterial reconstruction to eliminate stenosis and possible emboli, and improvement of distal perfusion. Our successful reconstructive techniques included thoracic outlet decompression and interpositional bypass of the subclavian artery in the 16-year-old patient, pectoralis muscle and tendon decompression to relieve compression of the axillary artery in the 19-year-old, and patch angioplasty for endofibrosis affecting the external iliac artery in the 47-year-old. Each patient was asymptomatic on follow-up and had resumed participation in competitive athletics. The recognition and anatomic definition of an arteriopathy that produces exercise-induced ischemia enables the application of precise therapy that can produce a symptom-free outcome and the ability to resume competitive athletics.

Does post-stenotic dilatation enhance collateral flow?

Our goal was to investigate whether post-stenotic dilatation (PSD) enhances collateral blood flow. In vitro experiments and computer modeling analysis were used to study the flow through stenotic segments and through collateral channels in the presence and absence of PSD. Pulsatile blood flow was provided by a left heart simulator primed with glycerol or normal saline. Pressure gradients across the stenosis were measured at different "cardiac" outputs. Computer models were constructed to simulate the experiments. Flow patterns and pressure drop across the stenosis were determined for a steady flow of 3 L/min. We observed that PSD was associated with a larger pressure drop across the stenosis than the absence of PSD when the flow was occurring through the stenosis only. There was, however, no difference in the pressure drop between the two geometries when the flow was occurring through both the stenotic orifice and the collateral channels when saline solution was used, but a small pressure difference prevailed for glycerol. At all different geometries there was considerable turbulence at PSD, and PSD geometry was found to be either at a disadvantage or at no advantage when compared to the tapered geometry for the total flow past the stenosis. The PSD geometry, however, enhanced the flow through the collateral while the flow through the orifice decreased concomitantly, resulting in no net increase in the total flow. This was true for any proportion of the total flow going through the collateral channels. For the total flow past the stenosis, PSD does not offer a benefit over tapered geometry.

Prevention of contrast-induced nephropathy with sodium bicarbonate: a randomized controlled trial.

CONTEXT: Contrast-induced nephropathy remains a common complication of radiographic procedures. Pretreatment with sodium bicarbonate is more protective than sodium chloride in animal models of acute ischemic renal failure. Acute renal failure from both ischemia and contrast are postulated to occur from free-radical injury. However, no studies in humans or animals have evaluated the efficacy of sodium bicarbonate for prophylaxis against contrast-induced nephropathy. OBJECTIVE: To examine the efficacy of sodium bicarbonate compared with sodium chloride for preventive hydration before and after radiographic contrast. DESIGN, SETTING, AND PATIENTS: A prospective, single-center, randomized trial conducted from September 16, 2002, to June 17, 2003, of 119 patients with stable serum creatinine levels of at least 1.1 mg/dL (> or =97.2 micromol/L) who were randomized to receive a 154-mEq/L infusion of either sodium chloride (n = 59) or sodium bicarbonate (n = 60) before and after iopamidol administration (370 mg iodine/mL). Serum creatinine levels were measured at baseline and 1 and 2 days after contrast. INTERVENTIONS: Patients received 154 mEq/L of either sodium chloride or sodium bicarbonate, as a bolus of 3 mL/kg per hour for 1 hour before iopamidol contrast, followed by an infusion of 1 mL/kg per hour for 6 hours after the procedure. MAIN OUTCOME MEASURE: Contrast-induced nephropathy, defined as an increase of 25% or more in serum creatinine within 2 days of contrast. RESULTS: There were no significant group differences in age, sex, incidence of diabetes mellitus, ethnicity, or contrast volume. Baseline serum creatinine was slightly higher but not statistically different in patients receiving sodium bicarbonate treatment (mean [SD], 1.71 [0.42] mg/dL [151.2 [37.1] micromol/L] for sodium chloride and 1.89 [0.69] mg/dL [167.1 [61.0] micromol/L] for sodium bicarbonate; P =.09). The primary end point of contrast-induced nephropathy occurred in 8 patients (13.6%) infused with sodium chloride but in only 1 (1.7%) of those receiving sodium bicarbonate (mean difference, 11.9%; 95% confidence interval [CI], 2.6%-21.2%; P =.02). A follow-up registry of 191 consecutive patients receiving prophylactic sodium bicarbonate and meeting the same inclusion criteria as the study resulted in 3 cases of contrast-induced nephropathy (1.6%; 95% CI, 0%-3.4%). CONCLUSION: Hydration with sodium bicarbonate before contrast exposure is more effective than hydration with sodium chloride for prophylaxis of contrast-induced renal failure.