Wnt signaling mediates self-organization and axis formation in embryoid bodies

Embryonic stem cells (ESCs) form descendants of all three germ layers when differentiated as aggregates, termed embryoid bodies. In vivo, differentiation of cells depends on signals and morphogen gradients that provide instructive and positional cues, but do such gradients exist in embryoid bodies? We report here the establishment of anteroposterior polarity and the formation of a primitive streak-like region in the embryoid body, dependent on local activation of the Wnt pathway. In this region, cells undergo an epithelial-to-mesenchymal transition and differentiate into mesendodermal progenitors. Exogenous Wnt3a protein posteriorizes the embryoid body, resulting in predominantly mesendodermal differentiation. Conversely, inhibiting Wnt signaling promotes anterior character and results in neurectodermal differentiation. The activation of Wnt signaling and primitive streak formation requires external signals but is self-reinforcing after initiation. Our findings show that the Wnt pathway mediates the local execution of a gastrulation-like process in the embryoid body, which displays an unexpected degree of self-organization.

SWI/SNF complex prevents lineage reversion and induces temporal patterning in neural stem cells

Members of the SWI/SNF chromatin-remodeling complex are among the most frequently mutated genes in human cancer, but how they suppress tumorigenesis is currently unclear. Here, we use Drosophila neuroblasts to demonstrate that the SWI/SNF component Osa (ARID1) prevents tumorigenesis by ensuring correct lineage progression in stem cell lineages. We show that Osa induces a transcriptional program in the transit-amplifying population that initiates temporal patterning, limits self-renewal, and prevents dedifferentiation. We identify the Prdm protein Hamlet as a key component of this program. Hamlet is directly induced by Osa and regulates the progression of progenitors through distinct transcriptional states to limit the number of transit-amplifying divisions. Our data provide a mechanistic explanation for the widespread tumor suppressor activity of SWI/SNF. Because the Hamlet homologs Evi1 and Prdm16 are frequently mutated in cancer, this mechanism could well be conserved in human stem cell lineages. PAPERCLIP:

The potential clinical role of ultrasonic strain and strain rate imaging in diagnosing acute rejection after heart transplantation

BACKGROUND

There has been a continued search for a more sensitive noninvasive technique for detecting sub-clinical acute rejection in heart transplant recipients. Ultrasonic deformation imaging (strain/strain rate) is sensitive in detecting sub-clinical abnormalities in regional systolic function and could potentially be sufficiently sensitive to detect changes in deformation induced by graft rejection.

AIM

To assess the use of strain (S) and strain rate (SR) imaging as a noninvasive method for monitoring and diagnosing acute rejection in heart transplant recipients.

METHODS AND RESULTS

A prospective preliminary study was carried out involving 31 consecutive heart transplant patients who underwent a total of 106 routine follow up endomyocardial biopsy with correlative cardiac ultrasound data. To assess regional longitudinal deformation, ultrasonic S and SR data were acquired from the intraventricular septum, left ventricular (LV) lateral and right ventricular free walls (RVFW). For radial deformation, data were obtained from the LV posterior wall (LVPW). According to the International Society of Heart and Lung Transplantation criteria, 88 biopsies (Group 1) had grade 0 or IA rejection, and 18 biopsies (Group 2) had > or =grade IB rejection. Longitudinal peak systolic S and SR were decreased (p<0.05) in Group 2, compared to Group 1 in the RVFW basal and apical segments and the basal and mid segments of the LV lateral wall. Radial peak systolic S and SR were significantly lower (p<0.001) in Group 2, compared to Group 1.

CONCLUSIONS

S/SR imaging might be a good technique and an additional tool for detecting > or =IB grade of acute rejection. The myocardial deformation, as assessed by S/SR imaging could be of clinical value in monitoring and diagnosing acute rejection in heart transplant recipients and could improve patients' management by reducing the number of biopsies performed.

Thigh-worn accelerometry for measuring movement and posture across the 24-hour cycle: a scoping review and expert statement

INTRODUCTION

The Prospective Physical Activity Sitting and Sleep consortium (ProPASS) is an international collaboration platform committed to harmonise thigh-worn accelerometry data. The aim of this paper is to (1) outline observational thigh-worn accelerometry studies and (2) summarise key strategic directions arising from the inaugural ProPASS meeting.

METHODS

(1) We performed a systematic scoping review for observational studies of thigh-worn triaxial accelerometers in free-living adults (n≥100, 24 hours monitoring protocols). (2)Attendees of the inaugural ProPASS meeting were sent a survey focused on areas related to developing ProPASS: important terminology (Q1); accelerometry constructs (Q2); advantages and distinct contribution of the consortium (Q3); data pooling and harmonisation (Q4); data access and sharing (Q5 and Q6).

RESULTS

(1) Eighty eligible articles were identified (22 primary studies; n~17 685). The accelerometers used most often were the ActivPAL3 and ActiGraph GT3X. The most commonly collected health outcomes were cardiometabolic and musculoskeletal. (2) None of the survey questions elicited the predefined 60% agreement. Survey responses recommended that ProPASS: use the term physical behaviour or movement behaviour rather than 'physical activity' for the data we are collecting (Q1); make only minor changes to ProPASS's accelerometry construct (Q2); prioritise developing standardised protocols/tools (Q4); facilitate flexible methods of data sharing and access (Q5 and Q6).

CONCLUSIONS

Thigh-worn accelerometry is an emerging method of capturing movement and posture across the 24 hours cycle. In 2020, the literature is limited to 22 primary studies from high-income western countries. This work identified ProPASS's strategic directions-indicating areas where ProPASS can most benefit the field of research: use of clear terminology, refinement of the measured construct, standardised protocols/tools and flexible data sharing.

Serum concentration of procoagulant, endothelial and oxidative stress markers in early primary varicose veins

OBJECTIVE

Endothelial disorders of the veins are considered to play a role in the pathogenesis of primary varicose veins and oxidative stress is implicated in these disorders. With this aim, we investigated vascular endothelial marker levels and the effect of endothelial damage on coagulation parameters and vasodilator substances to determine metabolic markers of oxidative stress in patients with varicose veins and vascular endothelial damage caused by oxidative stress.

METHODS

We investigated the levels of malondialdehyde (MDA), protein C, protein S, fibrinogen, von Willebrand factor (vWf), tissue plasminogen activator (tPA), vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), interleukin-12 (IL-12) and nitric oxide (NO) in the blood taken from the brachial vein of 25 patients with primary varicose veins (study group) and compared the results with 25 healthy volunteers (control group). We also investigated the urinary levels of prostaglandin I2 (PGI2) in the study group and compared the results with the control group.

RESULTS

There was no statistically significant difference between the study group and the control group with respect to the plasma levels of MDA, protein C, fibrinogen, tPA, IL-6, NO and urinary levels of PGI2. But plasma levels of protein S, vWf, VEGF and IL-12 were found to be statistically significantly higher in the study group than in the control group.

CONCLUSIONS

Although the systemically measured levels of protein S, vWf, VEGF and IL-12 were found to be higher in patients of primary varicose veins, levels of protein C, fibrinogen, homocysteine and PGI2 were not found to be statistically significant. No systemic increased oxidative stress seems to be related to the early stages of chronic venous insufficiency. Further studies are warranted for understanding the role of molecules such as NO, oxidative stress parameters and cytokines.

Comparison of real-time tri-plane and conventional 2D dobutamine stress echocardiography for the assessment of coronary artery disease

AIMS

Although dobutamine stress echocardiography (DSE) is an accepted tool for the diagnosis of coronary artery disease (CAD), it requires subsequent image acquisitions of the left ventricle (LV) in order to visualize all segments. This makes the procedure relatively time-consuming and might limit its accuracy. With the introduction of matrix array transducers, the real-time simultaneous acquisition of all LV segments has become possible using multi-plane imaging. The purpose of this study was: (i) to test the feasibility and efficiency of real-time tri-plane (RT3P) imaging during DSE, (ii) to compare the accuracy of RT3P DSE in detecting CAD using coronary angiography as the reference method.

METHODS AND RESULTS

Thirty-six patients suspected of CAD were prospectively enrolled. Both conventional two-dimensional (2D) and RT3P imaging were performed during a DSE protocol. Coronary angiography was performed within 24 h. Ultrasound data were acquired at each stage of the DSE. The total effective acquisition time for RT3P imaging was significantly shorter (55+/-29 vs. 137+/-63 s, P<0.001). Data yield was similar for both methods (2D: 98% vs. 3D: 97%). Overall sensitivity (93%), specificity (75%), and accuracy (89%) were identical between both methods. On a segmental level, the sensitivity, specificity, and accuracy of the RT3P and the 2D DSE were similar.

CONCLUSION

RT3P imaging fastens the DSE protocol without compromising the accuracy for the diagnosis of CAD. This could facilitate a more wide-spread use of DSE and therefore contributes positively to its routine clinical acceptance.

Quantitative dobutamine stress echocardiography for the early detection of cardiac allograft vasculopathy in heart transplant recipients

BACKGROUND

A non-invasive method to detect the presence of cardiac allograft vasculopathy (CAV) remains an important goal in clinical cardiology.

OBJECTIVE

To assess the value of quantitative dobutamine stress echocardiography (DSE) for the early detection of CAV.

METHODS

42 heart transplant recipients underwent DSE with acquisition of both conventional two-dimensional and colour tissue Doppler data. All studies were analysed conventionally and quantitatively using regional deformation parameters-that is, peak systolic longitudinal strain (in(peak sys)), strain rate (SR(peak sys)) and post-systolic strain index. Myocardial segments were classified as normal, mildly abnormal or severely abnormal based on correlative angiographic findings.

RESULTS

At baseline, in(peak sys) was significantly lower in severely abnormal segments than in normal ones. However, at peak stress, in(peak sys) was able to separate three groups of segments. Receiver operating characteristic analysis showed an SR(peak sys) response of <0.5/s to identify patients with CAV with a sensitivity of 88%, specificity of 85% and a negative predictive value of 92%.

CONCLUSION

Regional myocardial function is impaired in heart transplant recipients with CAV even when the disease is considered to be non-significant on conventional angiography. Systolic deformation parameters tended to detect the existence of CAV more accurately than conventional visual DSE assessment. Strain rate imaging during stress can therefore safely be used as a non-invasive screening test for detecting CAV in heart transplant recipients.

Thyroid cancer in toxic and non-toxic multinodular goiter

BACKGROUND

Many authors have claimed that hyperthyroidism protects against thyroid cancer and believed that the incidence of malignancy is lower in patients with toxic multinodular goiter (TMG) than in those with non-toxic multinodular goiter. But in recent studies, it was reported that the incidence of malignancy with TMG is not as low as previously thought.

AIM

To compare the thyroid cancer incidence in patients with toxic and non-toxic multinodular goiter.

SETTINGS AND DESIGN

Histology reports of patients treated surgically with a preoperative diagnosis of toxic and non-toxic multinodular goiter were reviewed to identify the thyroid cancer incidence. Patients having a history of neck irradiation or radioactive iodine therapy were excluded from the study.

MATERIALS AND METHODS

We reviewed 294 patients operated between 2001-2005 from toxic and non-toxic multinodular goiter. One hundred and twenty-four of them were toxic and 170 were non-toxic. Hyperthyroidism was diagnosed by elevated tri-iodothyroinine / thyroxine ratios and low thyroid-stimulating hormone with clinical signs and symptoms. All patients were evaluated with ultrasonography and scintigraphy and fine needle aspiration biopsy.

STATISTICAL ANALYSIS USED

Significance of the various parameters was calculated by using ANOVA test.

RESULTS

The incidence of malignancy was 9% in the toxic and 10.58% in the non-toxic multinodular goiter group. Any significant difference in the incidence of cancer and tumor size between the two groups could not be detected.

CONCLUSIONS

The incidence of malignancy in toxic multinodular goiter is not very low as thought earlier and is nearly the same in non-toxic multinodular goiter.

Doppler Tissue Evaluation of Atrial Conduction Properties in Patients With Non-alcoholic Fatty-liver Disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in clinical practice, and there is an increasing trend in its prevalence in the general population. Recent studies have demonstrated increased risk of atrial fibrillation (AF) in NAFLD. However, information on the mechanism of increased risk of AF in NAFLD is lacking. Impaired atrial conduction is an important factor in the pathophysiology of AF. We aimed to investigate atrial conduction properties in patients with NAFLD by tissue Doppler echocardiography. Fifty-nine ultrasound diagnosed NAFLD patients without clinical diagnosis of hypertension, diabetes mellitus, or cardiac disease and 22 normal subjects as controls were included in this study. Atrial conduction properties were assessed by electromechanical delay (EMD) derived from Doppler tissue echocardiography examination and P-wave dispersion (PWD) calculated from the 12-lead electrocardiogram. Inter-atrial and intra-atrial EMD intervals were significantly longer in NAFLD patients than in controls (inter-atrial EMD, 31.9 ± 8.5 ms vs. 23.4 ± 4.6 ms,p= 0.0001, and intra-atrial EMD, 14.3 ± 5.2 vs. 10.2 ± 4.0 ms,p= 0.001). Similarly, PWD was significantly higher in NAFLD patients compared with controls (49.2 ± 6.3 ms vs. 43.3 ± 4.2 ms,p= 0.0001). Maximum left atrial volume was also significantly higher in the NAFLD group than in controls (51 ± 11 mL vs. 34 ± 9 mL,p< 0.0001). This study demonstrated that atrial conduction is impaired in patients with NAFLD. Also, in a patient population of NAFLD without any clinical diagnosis of cardiac disease, diabetes, or hypertension, left atrial volume was increased compared with controls. These findings suggest impaired atrial conduction as a factor in increased risk of AF in NAFLD.

Usefulness of N-terminal pro-B-type natriuretic peptide to predict clinical course in patients with hypertrophic cardiomyopathy

This study was designed to assess the value of plasma N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) levels in predicting clinical courses in 80 patients with hypertrophic cardiomyopathy. Patients were followed for a mean of 571 +/- 294 days for clinical end points, defined as a composite of cardiovascular death and hospitalization for worsening heart failure symptoms. NT-pro-BNP plasma level (hazard ratio 1.6, 95% confidence interval 1.10 to 2.55, p = 0.015) and New York Heart Association (NYHA) functional class (hazard ratio 3.7, 95% confidence interval 1.17 to 12.09, p = 0.025) were the independent variables associated with increased risk for experiencing clinical end points. NT-pro-BNP plasma level > or =1,500 pg/ml detected patients with clinical end points with sensitivity, specificity, and accuracy of 83%, 81%, and 81%, respectively. The hypertrophic cardiomyopathy population was stratified into low-, medium-, and high-risk subgroups using 2 simple variables, NYHA functional class and NT-pro-BNP. Patients in lower NYHA classes and with NT-pro-BNP levels <1,500 pg/ml were significantly free of clinical end points. In conclusion, for patients with hypertrophic cardiomyopathy, plasma levels of NT-pro-BNP seem a reliable parameter to identify those at risk for clinical deterioration at long-term follow-up in conjunction with symptomatic status.

Evaluation of myocardial bridges with 64-slice computed tomography coronary angiography

OBJECTIVE

The aim of this study is to report the characteristics of myocardial bridging (MB) using 64-slice computed tomography and to demonstrate the association between atherosclerotic coronary artery disease (CAD) and MB.

METHODS AND RESULTS

In 990 consecutive patients who underwent multi-slice computed tomography (MSCT) coronary angiography for suspected or known coronary artery disease, myocardial bridge evaluation was performed with axial, curved multiplanar reconstruction and three-dimensional volume-rendered images. 265 bridged segments were identified in 223 (22.5%) patients. Multiple MBs on left coronary arteries were found in 41 patients. Most of the MBs were in the LAD (62.6%), followed by the obtuse marginal artery (14.7%) and diagonal artery (14.3%). The average length of MBs was 14 +/- 7 mm, and the average depth was 1.6 +/- 11 mm. No significant difference was observed between patients with and without MB on the middle LAD in respect of age, gender, prevalence of diabetes, hyperlipidaemia, hypertension, current smoking and prevalence of atherosclerotic plaques at the proximal LAD. On the other hand, prevalence of atherosclerotic plaques at the distal LAD were significantly lower in patients with MB on the middle LAD (3.5% vs. 19.7%, P: 0.0001).

CONCLUSIONS

The presence and morphological characteristics of MB and its relation with atherosclerotic plaques in the involved coronary artery can be comprehensively analysed with 64-slice computed tomography coronary angiography. Atherosclerosis is a common finding in segments proximal to MB, but the prevalence of plaques in equivalent segments (proximal LAD in our study) is not higher than in patients under similar coronary artery disease risk and without MB. On the other hand, prevalence of atherosclerotic plaques at the distal LAD was significantly lower in our patients with MB on the middle LAD. Finally, we suggest that rather than causing proximal atherosclerosis, MB might have a more important role in the protection of distal segments of the bridged arteries from atherosclerosis.

Ultrasonic strain/strain rate imaging—a new clinical tool to evaluate the transplanted heart

OBJECTIVE

The aim of this study was to investigate the clinical applicability of strain and strain rate imaging (epsilon/SRI) in heart transplantation (Htx) patients and to establish "normal" post-Htx regional systolic deformation values.

BACKGROUND

Epsilon/SR indices have been shown to be a more sensitive measure of regional systolic function than standard echo measurements. Thus, they might provide a new tool to better define both normal cardiac graft function and detect changes due to post-Htx complications. However, prior to investigating the role of epsilon/SRI in detecting abnormalities, "normal" post-Htx regional deformation values must be established as graft regional function can be altered by a number of factors such as ischemic time, surgical technique or accelerated graft ageing.

METHODS

A total of 57 Htx patients (age 36+/-12 years; post-Htx 5.5+/-3 years) without any documented complication were studied. Epsilon/SRI data were acquired from the septum, left ventricular (LV) free walls and right ventricular free wall (RVFW). A total of 29 age-matched healthy subjects served as controls.

RESULTS

Htx longitudinal peak systolic velocities (Vsys) were lower in inferior, septal and RVFW segments compared to controls. Peak systolic epsilon/SR (epsilonsys/SRsys)) did not differ from controls except in septum and RVFW in which the values were significantly reduced. Radial Vsys) in the Htx group were higher than controls while epsilonsys/SRsys were reduced. There was a significant decrease in SR(sys) in apical LV segments with increasing time post-Htx, whereas those measured in RVFW showed an increase by that time.

CONCLUSION

Epsilon/SRI demonstrated that "healthy" Htx hearts have normal global systolic function but altered regional systolic deformation indices compared to normal hearts. Post-Htx time has a diminishing effect on the regional systolic deformation indices in LV segments but an improving effect in RVFW. These "normal" Htx values should provide the basis for subsequent studies into the role of epsilon/SRI in the non-invasive detection of post-Htx complications.

Alpha-interferon and isoprinosine in adult-onset subacute sclerosing panencephalitis

We report eight patients with adult-onset subacute sclerosing panencephalitis (SSPE), of which, four were treated with oral isoprinosine and four with intraventricular alpha-interferon plus oral isoprinosine. One of the four patients treated with oral isoprinosine died within two months, and the disease progressed in three patients. Of the four patients treated with oral isoprinosine plus intraventricular alpha-interferon, one showed mild progression, one remission, and the remaining two showed stabilization. The group of patients is relatively small, but our results suggest that treatment with oral isoprinosine plus alpha-interferon is effective for SSPE.

The effect of various cooking methods on resistant starch content of foods

Purpose

Resistant starch, defined as all starch and starch-degradation products not absorbed by small intestine of healthy individuals, is included in the diet of individuals due to its prebiotic characteristics and protective effects against diseases like colon cancer, type II diabetes, obesity and cardiovascular diseases. Some cooking methods are known as effective on resistant starch content of foods. The purpose of this paper is to explore the effect of various cooking methods on resistant starch content of foods.

Design/methodology/approach

Potential health benefits and functional features of the resistant starch have been emphasized in the recent years. This review includes up-to-date scientific findings in different studies on the effect of various cooking methods on resistant starch content of foods. Advantages and nutritional quality of resistant starch are included to topic.

Findings

Cooking methods including baking, steaming and autoclave cooking increased the amount of the resistant starch of foods, but cooking method such as pressure cooking decreased the amount of the resistant starch of foods. Boiling, frying, microwave cooking and extrusion cooking have the potential of increasing the amount of resistant starch, which depends on the source of starch and the process conditions. Although frying method has a high potential to increase the resistant starch content of foods, it is inconvenient to recommend frying to modify resistant starch content of foods due to detrimental effects of frying and products on health.

Originality/value

This paper focuses on the effects of various cooking methods on resistant starch content of foods, which offers a promising future for the inartificial development of the prebiotic content of diet. Due to its potential health benefits, appropriate cooking methods should be preferred to increase resistant starch content of foods.

Right ventricular longitudinal deformation parameters and exercise capacity : prognosis of patients with chronic thromboembolic pulmonary hypertension

OBJECTIVE

Chronic thromboembolic pulmonary hypertension (CTEPH) is a progressive disease characterized by increased pulmonary vascular resistance resulting in pulmonary hypertension and right heart failure. The six-minute walk test (6MWT) distance is associated with the prognosis of CTEPH patients. Speckle tracking echocardiography (STE) is a reliable method for determining ventricular function. The aim of this study was to assess and compare the right ventricular (RV) function of CTEPH patients according to their 6MWT distances.

METHODS

Forty-nine consecutive CTEPH patients (mean age, 50 ± 16 years; 22 male) who were referred to our center for pulmonary thromboendarterectomy (PTE) were included in the study. All patients underwent the 6MWT and right heart catheterization (RHC). Standard echocardiography and STE were performed on all patients before PTE. Patients were divided into two groups based on their 6MWT distance being less or more than 300 m.

RESULTS

Patients with a shorter 6MWT distance had a significantly larger RV, while they had a significantly lower RV fractional area change and higher myocardial performance index suggesting impaired RV function. Both RV basal-lateral strain and strain rate measures were significantly lower in patients with shorter 6MWT distances than those with longer 6MWT distances. Similarly, they had lower RV basal-septal, mid-lateral, and global strain measures. 6MWT distances were correlated with RV basal-lateral and mid-lateral strain measures (r = 0.349, p = 0.025 and r = 0.415, p = 0.008, respectively).

CONCLUSION

Our data suggest that RV myocardial deformation parameters are associated with 6MWT distances. Determination of RV dysfunction by STE may be helpful in identifying patients with a poor prognosis.

Epicardium-derived cells organize through tight junctions to replenish cardiac muscle in salamanders

The contribution of the epicardium, the outermost layer of the heart, to cardiac regeneration has remained controversial due to a lack of suitable analytical tools. By combining genetic marker-independent lineage-tracing strategies with transcriptional profiling and loss-of-function methods, we report here that the epicardium of the highly regenerative salamander species Pleurodeles waltl has an intrinsic capacity to differentiate into cardiomyocytes. Following cryoinjury, CLDN6+ epicardium-derived cells appear at the lesion site, organize into honeycomb-like structures connected via focal tight junctions and undergo transcriptional reprogramming that results in concomitant differentiation into de novo cardiomyocytes. Ablation of CLDN6+ differentiation intermediates as well as disruption of their tight junctions impairs cardiac regeneration. Salamanders constitute the evolutionarily closest species to mammals with an extensive ability to regenerate heart muscle and our results highlight the epicardium and tight junctions as key targets in efforts to promote cardiac regeneration.

The transcription factor odd-paired regulates temporal identity in transit-amplifying neural progenitors via an incoherent feed-forward loop

Neural progenitors undergo temporal patterning to generate diverse neurons in a chronological order. This process is well-studied in the developing Drosophila brain and conserved in mammals. During larval stages, intermediate neural progenitors (INPs) serially express Dichaete (D), grainyhead (Grh) and eyeless (Ey/Pax6), but how the transitions are regulated is not precisely understood. Here, we developed a method to isolate transcriptomes of INPs in their distinct temporal states to identify a complete set of temporal patterning factors. Our analysis identifies odd-paired (opa), as a key regulator of temporal patterning. Temporal patterning is initiated when the SWI/SNF complex component Osa induces D and its repressor Opa at the same time but with distinct kinetics. Then, high Opa levels repress D to allow Grh transcription and progress to the next temporal state. We propose that Osa and its target genes opa and D form an incoherent feedforward loop (FFL) and a new mechanism allowing the successive expression of temporal identities.

The brain consists of billions of neurons that come in a range of shapes and sizes, with different types of neurons specialized to perform different tasks. Despite their diversity, all of these neurons originate from a single population known as neural stem cells. As the brain develops, each neural stem cell divides to produce two daughter cells: one remains a stem cell, which can then divide again, and the other becomes a neuron.

A longstanding question in developmental biology is how a limited pool of neural stem cells can generate so many different types of neurons. The answer seems to lie in a process known as temporal identity, whereby neural stem cells of different ages give rise to different types of neurons. This requires neural stem cells to keep track of their own age, but it is still unclear how they can do so.

Abdusselamoglu et al. have now uncovered part of the underlying mechanism behind temporal identity by studying fruit flies, an insect in which the early stages of brain development are similar to the ones in mammals. A method was developed to sort fly neural stem cells into groups based on their age. Comparing these groups revealed that a protein called Opa make neural stem cells switch from being 'young' to being 'middle-aged'. Another protein, Osa activates Opa, which in turn represses a protein called Dichaete. As Dichaete is mainly active in young neural stem cells, the actions of Osa and Opa push neural stem cells into middle age.

Fruit flies are therefore a valuable system with which to study the mechanisms that regulate neural stem cell aging. Revealing how the brain generates different types of neurons could help us study the way these cells organize themselves into complex circuits. This knowledge could then be harnessed to understand how these processes go wrong and disrupt development.

Chronic cigarette smoking affects left and right ventricular long-axis function in healthy young subjects: a Doppler myocardial imaging study

OBJECTIVE

Cigarette smoking is one of the major risk factors for coronary artery disease. However, chronic smoking has additional cardiac adverse effects independent of coronary atherosclerosis. We assessed the possible effects of chronic smoking on left and right ventricular (LV, RV) long-axis function using Doppler myocardial imaging (DMI).

METHODS

Forty otherwise healthy smokers (mean age = 26+/-3 years) and 40 age-matched nonsmoking controls enrolled. Standard echocardiography protocol was followed by DMI. Peak systolic (V(S)), early (V(E)) and late diastolic (V(A)) velocities, peak systolic strain (S), and strain rate (SR) were measured from septal, lateral, and RV free walls.

RESULTS

The baseline characteristics of two groups were similar. There were significant differences regarding Doppler myocardial velocity, S, and SR indices. Septal V(E) (P < 0.04), S (P < 0.0001) and SR (P < 0.02) were significantly reduced in smokers. For both lateral and RV free wall, V(S) (P < 0.003, P < 0.002, respectively), V(E) (P < 0.0001, P < 0.002, respectively), S (P < 0.0001 for both), and SR (P < 0.0001, P < 0.002, respectively) were significantly reduced in smokers. There were significant correlations between the amount of smoking and septal, lateral, and RV free wall S and SR.

CONCLUSIONS

Chronic cigarette smoking causes alterations in long-axis systolic and diastolic functions of right and left ventricles in healthy young subjects. These changes can be accurately detected with Doppler myocardial velocity and SR imaging.

Changes in physical activity and adiposity with all-cause, cardiovascular disease, and cancer mortality

Background

The relationship between joint changes in physical activity and adiposity with mortality is not well understood. We examined the association of changes in these two established risk factors with all-cause (ACM), cardiovascular disease (CVD), and cancer mortality.

Methods

We used longitudinal data from Taiwan’s MJ Cohort, comprising 116,228 general population adults recruited from 1998-2013 with repeated measures 4.6 y (2.5) apart and followed up for mortality for 11.9 y (3.5). Physical activity, body mass index (BMI), waist circumference (WC), and body fat percentage (BF%) groups and changes were based on public health and clinical guidelines.

Results

Compared to stable-insufficient physical activity, increasing physical activity from any baseline level was associated with lower ACM (HR [95%CI]): 0.85 [0.74, 0.96]) and CVD mortality (0.72 [0.55, 0.93]) risk. This was approximately equal to meeting physical activity guidelines at both timepoints (eg: 0.71 [0.58, 0.88] for CVD mortality). Compared to stable-overweight/moderate adiposity, decreasing adiposity level attenuated but did not offset mortality risk for all three outcomes (eg: BMI = 0.95 [0.76, 1.16] for CVD mortality). Only maintaining a healthy adiposity level at both timepoints offset mortality risk (BMI = 0.75 [0.61, 0.89]) for CVD mortality). In the joint changes analyses, lower mortality risk was a consequence of increases in physical activity across adiposity change groups (eg: WC decrease = 0.57 [0.48, 0.67]; WC stability = 0.73 [0.66, 0.80], WC increase = 0.83 [0.72, 0.97] for ACM). Decreasing adiposity attenuated the negative associations of decreased physical activity (BF% = 1.13 [0.95, 1.35] for ACM).

Conclusions

We found a lower risk for ACM, CVD, and cancer mortality from increasing physical activity and an attenuation from decreasing adiposity regardless of baseline levels. The beneficial associations of joint changes were primarily driven by physical activity, suggesting lower mortality risk may be more immediate through physical activity improvements compared to adiposity improvements alone.

The effect of lidocaine/prilocaine cream on an experimental wound healing model

The effects of lidocaine/prilocaine cream on wound healing were evaluated in this study. An incisional wound model on abdominal wall was performed on mice. A full thickness skin incision 2 cm in length was performed then it was sutured primarily with 4/0 polypropylene. In group I (n = 10) only suturing was done (control group), in group II (n = 10) lidocaine cream was applied after suturing on wound site and it was repeated for 6 days (twice in a day), in group III (n = 10) lidocaine/prilocaine cream was applied topically after suturing and repeated 6 days (twice in a day). At day 7, incisions were excised for evaluating tensile strength and 5-hydroxyproline (5-HP) values. Tensile strength values were lowest in control group and highest in lidocaine/prilocaine treatment group. 5-HP values were also expressed the same results. Both tensile strength and 5-HP values increased significantly in treatment groups in regard to the control (p < 0.05). It was concluded that lidocaine/prilocaine cream as topical anaesthetic agent had no adverse effect in an incisional wound model, furthermore it may have some beneficial effects on wound healing which remains to be evaluated and it can be used safely in day-to-day emergency practices.

Vascular Graft Infection by Staphylococcus aureus: Efficacy of Cefazolin, Teicoplanin and Vancomycin Prophylaxis Protocols in a Rat Model

OBJECTIVES

Prophylactic efficiencies of cefazolin, teicoplanin and vancomycin in a dacron graft infection model caused by methicillin-susceptible (MSSA) or -resistant Staphylococcus aureus (MRSA) were investigated.

DESIGN

Prospective, randomized, controlled animal study.

MATERIALS AND METHODS

Infections were established subcutaneously in the back of rats by implantation of Dacron prostheses followed by topical inoculation onto grafts of MSSA or MRSA. Experimental groups were as follows: Uncontaminated group (control), MSSA- or MRSA-contaminated and untreated groups, MSSA- or MRSA-contaminated groups treated with cefazolin, teicoplanin or vancomycin by one of three regimens (one day, two days, or three days regimen). Grafts were removed 7 days after the implantation and evaluated by using sonication and quantitative blood agar culture.

RESULTS

Contaminated groups demonstrated graft infections. Cefazolin, teicoplanin and vancomycin profoundly prevented the graft infections in MSSA- or MRSA-contaminated groups. For each antibiotic regimen, the most effective prevention was achieved by the drugs given as three days regimen. For MSSA and MRSA, the order of the effectiveness was as follows: teicoplanin>vancomycin>cefazolin.

CONCLUSION

As a prophylactic agent, teicoplanin seems to be more effective than vancomycin and cefazolin against vascular graft infections caused by MSSA and MRSA in rats.

Fibrillatory wave amplitude as a marker of left atrial and left atrial appendage function, and a predictor of thromboembolic risk in patients with rheumatic mitral stenosis

BACKGROUND

Patients with mitral stenosis, especially those with atrial fibrillation, are at increased risk for thromboembolic complications. Size of the left atrium, left atrial appendage dysfunction and severity of mitral stenosis are known risk factors for thromboembolism in patients with mitral stenosis. It has been postulated that F-wave amplitude on surface ECG is correlated with left atrial size, left atrial appendage function, and risk of thromboembolism in patients with nonrheumatic atrial fibrillation. The aims of this study were as follows: (1) to examine the relationship between surface ECG F-wave amplitude and left atrial appendage function, and (2) to assess the clinical significance of F-wave amplitude as it relates to risk of thromboembolism in a group of patients with rheumatic mitral stenosis.

MATERIAL AND METHODS

One hundred patients with rheumatic mitral stenosis and permanent atrial fibrillation but without moderate to severe mitral insufficiency were investigated by transthoracic and transesophageal echocardiography. Two groups were formed according to the presence of a coarse (Group 1; n=60; F-wave in lead V1> or =1 mm) or fine (Group 2; n=40; F-wave in lead V1<1 mm) F-wave on surface ECG.

RESULTS

Comparison showed that Group 1 had significantly smaller mitral valve area (1.44+/-0.6 versus 1.7+/-0.74 cm2, respectively; P<0.05), lower peak left atrial appendage flow velocity (18.8+/-2.1 versus 25.6+/-1.9 cm/s, respectively; P<0.005), higher-grade spontaneous echo contrast (2.05+/-1.44 versus 0.98+/-1.14, respectively; P<0.0001), and higher prevalence of thromboembolism (35% versus 12.5%, respectively; P<0.012). Multiple logistic regression analysis revealed that mitral valve area, left atrial appendage peak velocity, and coarse F-wave were independent clinical risk factors for thromboembolism in this patient group.

CONCLUSION

The data suggest that presence of a coarse F-wave on surface ECG is associated with left atrial appendage dysfunction, and indicates higher thromboembolic risk in patients with predominant rheumatic mitral stenosis.