RUES2 hESCs exhibit MGE-biased neuronal differentiation and muHTT-dependent defective specification hinting at SP1

RUES2 cell lines represent the first collection of isogenic human embryonic stem cells (hESCs) carrying different pathological CAG lengths in the HTT gene. However, their neuronal differentiation potential has yet to be thoroughly evaluated. Here, we report that RUES2 during ventral telencephalic differentiation is biased towards medial ganglionic eminence (MGE). We also show that HD-RUES2 cells exhibit an altered MGE transcriptional signature in addition to recapitulating known HD phenotypes, with reduced expression of the neurodevelopmental regulators NEUROD1 and BDNF and increased cleavage of synaptically enriched N-cadherin. Finally, we identified the transcription factor SP1 as a common potential detrimental co-partner of muHTT by de novo motif discovery analysis on the LGE, MGE, and cortical genes differentially expressed in HD human pluripotent stem cells in our and additional datasets. Taken together, these observations suggest a broad deleterious effect of muHTT in the early phases of neuronal development that may unfold through its altered interaction with SP1.

Stem Cell-Derived Human Striatal Progenitors Innervate Striatal Targets and Alleviate Sensorimotor Deficit in a Rat Model of Huntington Disease

Huntington disease (HD) is an inherited late-onset neurological disorder characterized by progressive neuronal loss and disruption of cortical and basal ganglia circuits. Cell replacement using human embryonic stem cells may offer the opportunity to repair the damaged circuits and significantly ameliorate disease conditions. Here, we showed that in-vitro-differentiated human striatal progenitors undergo maturation and integrate into host circuits upon intra-striatal transplantation in a rat model of HD. By combining graft-specific immunohistochemistry, rabies virus-mediated synaptic tracing, and ex vivo electrophysiology, we showed that grafts can extend projections to the appropriate target structures, including the globus pallidus, the subthalamic nucleus, and the substantia nigra, and receive synaptic contact from both host and graft cells with 6.6 ± 1.6 inputs cell per transplanted neuron. We have also shown that transplants elicited a significant improvement in sensory-motor tasks up to 2 months post-transplant further supporting the therapeutic potential of this approach.

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hESC-derived striatal progenitors give rise to MSNs in a neurotoxin model of HD

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Donor transplants extend projections to appropriate striatal target regions

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Grafted cells establish synaptic contact with both donor and resident cells

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Transplanted animals show improvements in HD-related sensorimotor responses

MR imaging evaluation of the postoperative meniscus

MR imaging has been widely evaluated in the assessment of patients with recurrent or residual symptoms following meniscal surgery. Importantly, the causes of such symptoms may relate to failure or complication of the surgical procedure, a possible recurrent or residual meniscal tear, or may be related to other causes of joint symptoms, including tears of the contralateral meniscus, or local hyaline cartilage, or marrow abnormalities subjacent to or distant to the meniscal surgical site. The complex diagnostic issues involved in the MR imaging evaluation of the postoperative meniscus were identified in early MR imaging studies. The knowledge of the normal MR imaging appearance of the knee after the more common repair procedures will allow radiologists to recognize complications associated with such procedures. In this article, we discuss the MR imaging evaluation of the knee after meniscal surgery.

Diagnostic value of computed tomography colonography (CTC) after incomplete optical colonoscopy

INTRODUCTION

This study evaluated the role of computed tomography colonography (CTC) in patients who previously underwent incomplete optical colonoscopy (OC). We analyzed the impact of colonic lesions in intestinal segments not studied by OC and extracolonic findings in these patients.

METHODS

Between January 2014 and May 2015, 61 patients with a history of abdominal pain and incomplete OC examination were studied by CTC. CTCs were performed by 320-row CT scan in both the supine and the prone position, without intravenous administration of contrast medium. In all patients both colonic findings and extracolonic findings were evaluated.

RESULTS

Among the study group, 24 CTC examinations were negative for both colonic and extracolonic findings while 6 examinations revealed the presence of both colonic and extracolonic findings. In 24 patients CTC depicted colonic anomalies without extracolonic ones, while in 7 patients it showed extracolonic findings without colonic ones.

DISCUSSION

CTC is a noninvasive imaging technique with the advantages of high diagnostic performance, rapid data acquisition, minimal patient discomfort, lack of need for sedation, and virtually no recovery time. CTC accurately allows the evaluation of the nonvisualized part of the colon after incomplete OC and has the distinct advantage to detect clinically important extracolonic findings in patients with incomplete OC potentially explaining the patient's symptoms and conditioning their therapeutic management.

CONCLUSION

CTC accurately allows the assessment of both colonic and extracolonic pathologies representing a useful diagnostic tool in patients for whom complete OC is not achievable.

Metabolic syndrome in patients with intermittent claudication referred to vascular rehabilitation

AIM

The prevalence of the metabolic syndrome, a clustering of cardiovascular risk factors whose underlying pathophysiology is related to insulin resistance, was estimated in patients with intermittent claudication referred to a short-course intensive rehabilitation program focused on physical training. Improvements in walking distance at the end of the program were also compared among patients with and without the syndrome.

METHODS

The metabolic syndrome was documented among 34 (39%) out of 87 enrolled patients, without significant differences between those with and without the syndrome concerning sex (males 91% vs 92% respectively, P=0.816), age (64+/-8 vs 65+/-7 years, P=0.54), coronary heart disease (44% vs 32%, P=0.365), localization of peripheral arterial disease, and impairment of walking capacity as evaluated by constant treadmill test (initial claudication distance (ICD) 156+/-93 vs 176+/-126 m, P=0.428; absolute claudication distance (ACD) 429+/-324 vs 409+/-269 m, P=0.756).

RESULTS

At the end of the program, both ICD and ACD significantly improved without any of significant differences between the two groups (ICD +152% vs +174% respectively, P=0.518; ACD +112% vs +177%, P=0.053).

CONCLUSIONS

Metabolic syndrome is frequent among patients with intermittent claudication and is not associated with poor response to physical training. Our data highlight the need for considering vascular rehabilitation in these patients in order to both improve walking capacity and minimize cardiovascular morbidity and mortality.

[Twenty-six consecutive patients with acute superior mesenteric infarction. Comparison of conventional radiology, ultrasonography, and computerized tomography]

Ischemic bowel disease is a rare disorder whose incidence is increasing as the mean age of the population increases. Diagnosis by clinical, laboratory and radiologic means is often difficult, and delay in definitive therapy results in substantial morbidity and mortality. A series of 26 consecutive patients, with proved acute superior mesenteric ischemia, was retrospectively reviewed: the authors report the diagnostic methods performed preoperatively, the site and the cause of infarction and the time passed between the first radiograph ans surgery. Plain abdominal radiographs were performed in 25 of 26 patients, screening abdominal US in 23 cases and CT in 19 cases. All radiological examinations were retrospectively reviewed by three authors, independently, to recognize the different signs of infarction. On plain abdominal films, the findings warranting a presumptive diagnosis of bowel infarction were air-fluid levels (84% of cases), dilated bowel loops (48%), thickened and unchanging loops (20%), gastric distension and gasless abdomen (12%), small bowel pseudo-obstruction (8%). Screening abdominal US demonstrated intraperitoneal free fluid (26%) and dilated bowel loops (22%). Abdominal CT showed air-fluid levels (79%), dilated loops and free intraperitoneal fluid (47%), intramural gas and thickened bowel loops (36.8%), engorgement of the mesenteric vessels (31%), mesenteric-portal gas, mesenteric thrombus and marked reduction in the volume of gas in the small bowel (10.5%) and paper-thin bowel loops (5%). The authors conclude that air-fluid levels, dilated loops and intraperitoneal free fluid are the most frequent findings, even though they are not specific. While abdominal plain film and screening ultrasonography can be negative, CT detects at least one abnormal finding and at least three abnormal findings in 73% of cases.

Prediction of late arrhythmic events after acute myocardial infarction from combined use of noninvasive prognostic variables and inducibility of sustained monomorphic ventricular tachycardia

A combined use of noninvasive techniques and electrophysiologic study in the prediction of arrhythmic events was prospectively evaluated in 303 surviving patients of acute myocardial infarction (AMI). The most powerful combination of noninvasive prognostic variables in identifying patients suitable for invasive strategies was also assessed. Patients who had > or = 2 variables among left ventricular ejection fraction < 0.4, ventricular late potentials and repetitive ventricular premature complexes (VPCs) were considered eligible for programmed ventricular stimulation. After 15 +/- 7 months of follow-up, 19 patients (6%) had an arrhythmic event. Left ventricular dyskinesia (p < 0.00001) and ejection fraction < 0.4 (p < 0.000001), late potentials (p < 0.001), filtered QRS duration > or = 106 ms (p < 0.00001), VPCs/hour > 6 (p < 0.05), paired VPCs (p < 0.01), > or = 2 runs of unsustained ventricular tachycardia (VT) per monitoring (p < 0.001), heart rate variability index < or = 29 (p < 0.00001) and mean RR interval < or = 750 ms (p < 0.01) were found to be significant univariate predictors of events. At multivariate analysis, only low left ventricular ejection fraction, prolonged filtered QRS duration, reduced heart rate variability index and detection of > or = 2 runs of unsustained VT per monitoring had an independent relation to late arrhythmic events. Of 67 eligible patients, 47 (70%) consented to undergo programmed stimulation. A positive electrophysiologic study was found to be the strongest independent predictor of events among patients preselected by noninvasive techniques. With a good sensitivity (81%), a combined use of noninvasive tests and electrophysiologic study selected a group of post-AMI patients at sufficiently high risk (event rate 65%) to be considered candidates for interventional therapy. The combination of > or = 2 variables among left ventricular ejection fraction < 0.4, filtered QRS duration > or = 106 ms and > or = 2 runs of unsustained VT was superior to the other ones in identifying high-risk subjects (positive and negative predictive values for arrhythmic events of 44 and 99%, respectively). On the basis of the data, this scheme appears to be the most appropriate for selecting patients suitable for electrophysiologic testing and invasive strategies after AMI.

Central and peripheral haemodynamic determinants of effort tolerance in patients with heart failure

We studied central and peripheral hemodynamics and exercise tolerance in 24 patients with left ventricular dysfunction. All were in NYHA class II or III, and echocardiographic left ventricular ejection fraction was < 35% without pharmacologic influences. Patients underwent to treadmill test (Naughton protocol), cardiopulmonary upright bicycle test, and supine bicycle test with haemodynamic measurements. All tests were exhaustive. Average exercise time was 9 +/- 3.4 min, (range 3-20). Average ejection fraction (.28 +/- 0.65) dis not correlate with working capacity (r = .32), nor did left ventricular filling pressure (pulmonary capillary wedge pressure) at rest and at peak exercise (r = .29 and r = .02). Stroke volume and stroke volume index were on average depressed, with no variations during work; cardiac output and cardiac index were also depressed, with a significant increase at peak exercise (both p < .001). Systemic and pulmonary resistances were increased, but systemic resistances tended to decrease during effort (p < .001), while pulmonary resistances did not (p = NS). We subdivided patients according to systemic vascular resistances lower or higher than 1500 dynes.cm.sec-5 at rest; this identifies two different working capacities (low systemic vascular resistances 11.7 +/- 4.4 min, high systemic vascular resistances 6.9 +/- 3.2 min, p < .05). Patients were then divided in two groups: group I (rest stroke volume > 60 ml) and group II (rest stroke volume < 60 ml). Group I worked 11 +/- 5 min, group II 8.5 +/- 3 min (p < .05). We performed a linear regression analysis between cardiac output and systemic vascular resistances at rest and during exercise in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Late arrhythmic events and patency of the infarct-related coronary artery in survivors of acute myocardial infarction

In the present study we evaluated the influence of intravenous thrombolysis and patency of the infarct-related coronary artery on both markers of ventricular electrical instability and incidence of late arrhythmic events after acute myocardial infarction (AMI). Ninety one patients surviving a first AMI who consecutively performed coronary angiography were enrolled in the present study; 44 patients (48%) received thrombolysis, 47 patients (52%) were treated conventionally. Of 91 patients, 90 (99%) had signal-averaged electrocardiogram (SAECG), and 40 (44%) programmed ventricular stimulation. No significant difference was observed between thrombolytic-treated and control group in late potential rate, SAECG determinants and ventricular arrhythmia inducibility. Of 91 patients, 40 (44%) had occlusion of the infarct-related artery: of these, 15 (37%) had late potentials compared with 5 of 51 patients (9%) with a patent artery (p < 0.01). Mean left ventricular ejection fraction was not significantly different between the two groups (0.50 +/- 0.15 vs 0.55 +/- 0.12; p = NS). No significant difference was present between the two groups of patients with regard to inducibility of sustained ventricular tachyarrhythmias, however an odds ratio of 3.5 was observed in the group with a closed vessel.(ABSTRACT TRUNCATED AT 250 WORDS)

[The electrocardiographic anomalies and 2D-echocardiographic findings during the recovery phase of the stress test in the postinfarct patient]

BACKGROUND

The appearance or the increase of repolarization abnormalities in the EKG during post exercise (ET) recovery phase (R) is considered a marker of ischemia.

METHODS

In order to evaluate the real meaning of these changes we compared the EKG data with eventual modifications of left ventricular kinesis analyzed by 2D-ECHO. 10 male patients with previous myocardial infarction, mean age 50 +/- 4.8 y, underwent exercise testing on a treadmill (Bruce's protocol) and continuous 2D-ECHO observation from the end of exercise along the whole R. Patients were divided in two groups: Group A (6 patients) and Group B (4 patients), all free of symptoms.

RESULTS

Group A showed ischemic EKG markers during exercise which increased during R; Group B showed ischemic EKG markers only during R. The 2D-ECHO showed in Group A an impairment of left ventricular kinesis at peak exercise without increase or extension during R (WMSI at rest 1.32; peak ET 1.60; R 1.60); in Group B the kinetic alterations appeared only in R (WMSI at rest 1.33, peak ET 1.42; R 1.80), strictly related to EKG markers.

CONCLUSIONS

The data suggest : 1) that the increase of EKG abnormalities already present during exercise do not seem to imply more severe ischemia; 2) that EKG changes appearing during R are markers of ischemia which occur in the R.

Regional flow responses to exercise

Both neural and humoral systems participate in the control of blood flow to various organs. Exercise places the greatest demands on the circulation. At rest, in humans, skeletal muscle receives somewhere between 15% and 20% of cardiac output, while during maximal exercise, this percentage reaches a value of 80% to 90%. The active human muscles have a high-flow capacity that exceeds the capacity of the heart to pump blood. Measurements in single human muscle have indicated that blood flow may be inhomogenous, that is, probably depending on variations of the vasomotor tone of the muscle mediated by humoral and neural factors. Exercise raises cardiac output and coronary blood flow, which rise linearly with increases in heart rate. In normal young men, coronary blood flow averages 280 ml/min/100 g of the left ventricle and reaches as high as 390 ml/min during moderately severe exercise, requiring about 85% of maximal heart rate. In nonexercising organs, the blood flow decreases at about 20% to 40% of the resting values, being the net result of competing vasoconstrictor and vasodilator drives.

Influence of thrombolysis on signal-averaged electrocardiogram and late arrhythmic events after acute myocardial infarction

The influence of intravenous thrombolysis on both prevalence of ventricular late potentials and incidence of late arrhythmic events was evaluated in 174 consecutive patients surviving a first acute myocardial infarction; 106 patients (61%) received thrombolysis (group A) and 68 (34%) had conventional therapy (group B). In group A, 18 patients (17%) had late potentials compared with 23 (34%) in group B (p less than 0.05); mean left ventricular ejection fraction was not different (0.50 +/- 0.09 vs 0.50 +/- 0.10; p = not significant [NS]). Of 63 patients who underwent coronary arteriography because of postinfarction ischemia, 28 (44%) had a closed infarct-related artery; of these, 11 (39%) had late potentials compared with 3 of 35 (9%) with a patent artery (p less than 0.01). Mean left ventricular ejection fraction was not significantly different between the 2 groups (0.49 +/- 0.09 vs 0.53 +/- 0.09; p = NS). At a mean follow-up of 14 +/- 8 months, 8 of 161 patients (5%) had a late arrhythmic event; 6 of 8 (75%) with and 28 of 153 (18%) without events had late potentials (p less than 0.001). In group A, 4 of 99 patients (4%) had events compared with 4 of 62 (6%) in group B (p = NS, relative risk 1.6). Of 24 patients with anterior wall AMI and left ventricular dyskinesia, 6 events occurred. In this group of patients, a higher rate of events was observed (25%); 3 of 16 (19%) treated with thrombolysis had an event compared with 3 of 8 (37%) treated conventionally (p = NS, relative risk 2.6).(ABSTRACT TRUNCATED AT 250 WORDS)

Functional evaluation 10 days and 3 weeks after acute myocardial infarction: comparative significance and prognostic value

Early functional evaluation after non-complicated acute myocardial infarction (AMI) is widely recommended because of its prognostic value in the short term. In fact it seems to have a prognostic value within 15-20 days of the AMI, but in this period the patient is particularly controlled and is often still hospitalized. To evaluate the real significance of an early functional evaluation within 10 days of the AMI (mean 8.6 days +/- 1.2) as compared to an identical functional evaluation performed at 3 weeks after AMI (mean 20.16 days +/- 5.38) 25 patients with uncomplicated myocardial infarction were studied. Significant statistical differences were found between the first (ET1) and second (ET2) functional evaluations: they concern the maximal heart rate reached (P less than 0.001), the maximal pressure-rate product (P less than 0.05), the percentage increment of heart rate (P less than 0.01) and the total work performed (P less than 0.001). Agreement between ET1 and ET2 was found in 19 cases; 12 patients showed markers of ischaemia both at ET1 and ET2, while seven were free from ischaemia at both times. In six cases a disagreement between ET1 and ET2 was found: in particular, three cases had ischaemic ET1 and nonischaemic ET2; the reverse was seen in the other three. During follow-up (mean 215.4 days +/- 85.5), the total number of new events (reinfarctions, angina or surgery) among the 25 patients was eight; none occurred within the first 30 days after the AMI.(ABSTRACT TRUNCATED AT 250 WORDS)