Promotion of the Differentiation of Dental Pulp Stem Cells into Oligodendrocytes by Knockdown of Heat-Shock Protein 27

Stem cell-based therapy has been evaluated in many different clinical trials for various diseases. This capability was applied in various neurodegenerative diseases, such as Alzheimer's disease, which is characterized by synaptic damage accompanied by neuronal loss. Dental pulp stem cells (DPSCs) are mesenchymal stem cells from the oral cavity and have been studied with potential application for regeneration of different tissues. Heat shock protein 27 (HSP27) is known to regulate neurogenesis in the process of neural differentiation of placenta-multipotent stem cells. Here, we hypothesize that HSP27 expression is also critical in neural differentiation of DPSCs. An evaluation of the possible role of HSP27 in differentiation of DPSCs was per-formed by gene knockdown and neural immunofluorescent staining. We found that HSP27 has a role in the differentiation of DPSCs and that knockdown of HSP27 in DPSCs renders cells to oligodendrocyte progenitors. In other words, shHSP27-DPSCs showed NG2-positive immunoreactivity and gave rise to oligodendrocytes or type-2 astrocytes. This neural differentiation of DPSCs may have clinical significance for treatment of patients with neurodegenerative diseases. In conclusion, our data provide an example of oligodendrocyte differentiation of a DPSCs model that may have potential application in human regenerative medicine.

Gastric Anatomic Type Is Associated with Obesity and Gender

OBJECTIVE

To enhance our understanding of the associations among gastric anatomy, obesity, and gender.

METHODS

777 randomly selected participants received health checkups, including a series of radiographs of the upper gastrointestinal tract (UGI); the findings were linked with each corresponding subject's gender and BMI. We measured the length, angle, and different portions of the stomach with the subjects in the standing position using radiographs to classify all individuals into anatomic types 1 through 6 based on gastric morphology. The gastric morphology was identified based on the initial UGI examination: 166 follow-up UGI radiographs at 12 ± 1.5 months to evaluate whether the stability of gastric anatomy persisted over time.

RESULTS

There was a significant difference in anatomic types between females and males (p < 0.001). The proportions of men with certain types (e.g., barium initially pools in a retroflexed fundus) were significantly higher than those of women; these participants were more likely to be overweight/obese (p < 0.001) compared with participants with other anatomic types. Additionally, the proportion of women with gastroptosis was significantly higher than that of men; participants with this type were less likely to be overweight/obese (p < 0.001).

CONCLUSION

Gastric anatomic types were associated with obesity and gender.

Carotid intima-media thickness and plaque occurrence in predicting stable angiographic coronary artery disease

BACKGROUND

Carotid intima-media thickness (CIMT) and plaque formation have been used as surrogate end-points for evaluating the regression and/or progression of atherosclerotic cardiovascular disease, but their predictive value for stable coronary artery disease (CAD) is inconclusive.

METHODS

Carotid ultrasonography was performed in patients who underwent noninvasive multislice computed tomography (MSCT) angiography for CAD suspected, due to chest pain. CIMT and plaque formation on the left and right common carotid arteries (CCAs), carotid bulb (CB), and proximal internal carotid arteries (ICAs) were evaluated, and the relationship between angiographic CAD, CIMT, and plaque formation was determined.

RESULTS

120 patients (95 male; 25 female), with a mean age ± standard deviation of 61 ± 11 years (range: 35-89 years) were recruited. Because age had a significant impact on CAD (r = 0.191; P = 0.036), CCA plaques (r = 0.368; P = 0.001), ICA plaques (r = 0.334; P = 0.004), and mean CIMT (r = 0.436; P = 0.001), patients were divided into two groups aged <60 years and ≥60 years. In the <60 years group, CIMT-CB was significantly higher in patients with CAD (P = 0.041), while in the ≥60 years group, mean CIMT, CIMT-CCA, and CIMT-CB were significantly higher in patients with CAD (P < 0.05, for each). In both groups, the occurrence of carotid plaques was significantly higher in patients with CAD than in those without CAD (P < 0.007, for each). After controlling for other risk factors, carotid plaques were an independent predictor of CAD in both groups (P < 0.05, for each), while CIMT-CB could independently predict CAD only in patients ≥60 years old (P = 0.031).

CONCLUSION

Our findings suggest that carotid plaques are a strong predictor of stable CAD. However, CIMT-CB could predict stable CAD only in patients over 60 years of age.

YC-1, a potent antithrombotic agent, induces lipolysis through the PKA pathway in rat visceral fat cells

This study investigated the effects of 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), a soluble guanylyl cyclase (sGC) activator and potential antithrombotic agent, on lipolysis in isolated visceral fat cells of the rat. Visceral fat cells were isolated from epididymal fat pads of rats and treated with YC-1 at different doses and times. Glycerol release, and intracellular cAMP and cGMP levels were analyzed by specific kits. Moreover, several inhibitors or drugs were used to examine the signal transduction pathways of YC-1-induced lipolysis in adipocytes. Herein we report that YC-1 stimulated glycerol release in dose- and time-dependent manners. Intracellular cAMP and cGMP levels of adipocytes both increased in time-dependent manners, but elevation of the cGMP level was faster and higher than that of the cAMP level after YC-1 treatment. An sGC inhibitor (ODQ) inhibited YC-1-induced glycerol release, indicating the involvement of sGC in YC-1-induced lipolysis. Administration of insulin, an activator of type-3B phosphodiesterase (PDE-3B), attenuated YC-1-induced lipolysis, indicating that elevation of the cAMP level is an important step in the lipolytic effect of YC-1. In addition, YC-1-induced lipolysis was inhibited by a protein kinase A (PKA) inhibitor (KT5720) but not by a PKG inhibitor (KT5823), indicating that YC-1-induced lipolysis occurs through a PKA-dependent pathway. A Western blot analysis showed that extracellular signal-regulated kinase was not phosphorylated by YC-1 treatment. In conclusion, our results suggest that YC-1 might stimulate lipolysis via activation of sGC/cGMP and then activation of the cAMP/PKA signaling cascade in isolated rat visceral adipocytes.

The correlation between three-dimensional vena contracta area and aortic regurgitation index in patients with aortic regurgitation

OBJECTIVES

The aims of this study are to explore the correlation between the three-dimensional vena contracta (3D VC) area and the aortic regurgitation (AR) index and to determine AR severity using the 3D VC area.

BACKGROUND

The geometry of regurgitant jets is complex in patients with AR. The 3D VC area can be easily cropped using any plane and we can obtain the complex geometry of the VC area.

METHODS

Full-volume three-dimensional (3D) color flow datasets were generated using the trans-thoracic parasternal approach. The AR jet could be well visualized and analyzed in three orthogonal planes using dedicated software.

RESULTS

We consecutively analyzed 77 AR patients with comprehensive 2D and 3D echocardiographic data. The 3D VC area increased proportionately with increasing AR severity using the AR index method (F = 86.1, P < 0.001) and correlated well with effective regurgitant orifice (P < 0.001). The cutoff value of the VC area was < 30 mm(2) (sensitivity = 90% and specificity = 88%) for predicting mild AR and > 50 mm(2) (sensitivity = 92% and specificity = 87%) for predicting severe AR.

CONCLUSION

3D color flow VC area measurement provides a simple and accurate method for assessing the severity of AR.

Diffusion tensor imaging in a symptomatic patient with an intra-axial arachnoid cyst

We present a case of an elderly lady with a symptomatic large intra-axial right frontoparietal arachnoid cyst displacing the corticospinal tract (CST) posteromedially on diffusion tensor imaging. This information assisted the surgeons in confirming the symptomatic nature of the lesion, in planning an appropriate surgical procedure, as well as in prognostication of recovery.

Prediction of severity of isolated aortic regurgitation by echocardiography: an aortic regurgitation index study

BACKGROUND

No single precise qualitative method is recommended for evaluating the severity of aortic regurgitation (AR). Quantitative methods for AR assessment are, typically, cumbersome and time-consuming. The purpose of this study was to develop a more comprehensive method for predicting the severity of AR.

METHODS

In all, 79 patients with normal left ventricular systolic function and at least mild AR were included in this prospective study. The standard references for evaluating AR severity were quantitative methods. The AR index consisted of 5 echocardiographic parameters: jet width ratio, vena contracta width, pressure half-time, jet density, and diastolic flow reversal in the descending aorta. Each parameter was scored on a 3-point scale from 1 to 3. The AR index was calculated as the sum of each score divided by the number of parameters. Thus, an increasing AR index score from 1 to 3 was indicative of increasing regurgitation.

RESULT

The study demonstrated that the numeric value of AR index increased proportionately to the quantitative grading of AR severity, and proved to be an accurate predictor for AR severity. A 1.8 threshold for the AR index offered a high level of sensitivity and negative predictive value for severe AR. The possibility of missing severe AR was low with AR index less than 1.8. A 2.6 threshold for the AR index provided high specificity and positive predictive value for severe AR. The possibility of diagnosing severe AR was extremely high with AR index of 2.6 or more.

CONCLUSION

AR index provided a more comprehensive method for predicting the degree of AR severity in this study. We suggest that the AR index should be considered for any evaluation of the severity of AR.

Is guidewire exchange a better approach for subclavian vein re-catheterization for chronic hemodialysis patients?

BACKGROUND

The objectives of this study were to compare outcomes and survival rates of subclavian vein re-catheterization through guide wire exchange (GWE) or de novo insertion (DN).

MATERIALS AND METHODS

The study was conducted in a retrospective manner. Medical records of 36 patients who received percutaneous subclavian vein re-catheterization for hemodialysis in our institution during the period from April 1, 2001 to September 30, 2004 were reviewed. All patients had at least 2 catheter insertions records in our institute. Incidences of adverse events (infection, thrombosis) were compared between GWE and DN groups using x2 test. Predictors for adverse event occurrences were analyzed using logistic regression models. Cox proportional hazard model was used to investigate the predictors for adverse event-free catheter days. Kaplan-Meire survival curves were computed and compared using log rank test.

RESULTS

Information were generated from 98 catheters (41 from DN, 57 from GWE groups). The average catheter usage was 2.8+/-0.9 devices per patient and the mean catheter-indwelling-day was 125.4+/-129.5 days in this cohort. We found GWE group had significantly lower thrombosis rate (49.1% vs. 85.4% for DN group, P<0.000) in general. Surgical approach was a significant risk factors for catheter thrombosis (GWE vs. DN, odds ratio=0.261, P=0.05). The actuarial survival rates for GWE were > or =30 days, 85.4%; > or =60 days, 75.5%; > or =90 days, 64.5%; > or =180 days, 44.3%. The actuarial survival rates for DN were > or =30 days, 70.7%; > or =60 days, 58.5%; > or =90 days, 34.2%; > or =180 days, 18.4%. GWE group catheters had significantly higher catheter survival rates (P=0.0009). Mahukar catheter (hazard ratio 0.514, P=0.03), non-shock (hazard ratio 3.358, P=0.04), and older age (hazard ratio 0.958, P=0.026) were predictors of adverse event-free remaining catheter days.

CONCLUSION

We suggest that GWE might be a favorable option over DN insertion when revised subclavian vein catheterization is inevitable. GWE can be performed repeatedly without compromising catheter outcomes.

Lumbosacral nerve root avulsion

Lumbosacral nerve root avulsion is a rare clinical entity. Since the first description in 1955, only 35 cases have been reported. It is often associated with pelvic fractures and may be missed in the initial clinical examination as these patients usually present with multiple injuries. We present three such cases with clinical and radiological findings. These patients were involved in road traffic accidents. Two had fractures of the sacroiliac joint with diastasis of the symphysis pubis (Tile type C 1.2) and one had fractures of the public rami (Tile type B 2.1). All three had various degrees of sensory and motor deficit of the lower limbs. Lumbar myelogram shows characteristic pseudomeningoceles in the affected lumboscral region. Magnetic resonance (MR) imaging provides an additional non-invasive modality to diagnose this condition.

Knee arthrodesis with interlocking nail after excision of giant cell tumour of the distal femur

Giant cell tumour of bone occurring around the knee is fairly common and can be difficult to manage. We report a case of such tumour involving the distal femur which was successfully treated with complete excision followed by arthrodesis of the knee with a long interlocking intramedullary nail.

Interlocking nails for treatment of femoral fractures

A series of 23 fractures of the femur were treated using femoral interlocking nails. The average follow-up period was 14.8 months. There were 14 closed fractures and 9 compound fractures. Closed nailing was done for 8 patients and open nailing for 15 patients. All the fractures united. There were no superficial or deep infections. The most common complication was leg length discrepancy; shortening occurred in 5 patients whereas lengthening occurred in 2 patients. It is a technically demanding procedure but it is the method of choice in our Institution for stabilising complex fractures of the femoral shaft.