Left ventricular remodelling and vascular adaptive changes in adolescents with obesity

BACKGROUND

The aim of this study was to determine the effects of obesity on myocardial mechanics and ventriculo-arterial coupling (V-A) in children.

METHODS

Strain parameters, stroke volume, arterial elastance, left ventricular (LV) elastance and V-A were compared after adjusting for age and hypertension and after multivariate sub-group analysis between patients with and without obesity.

RESULTS

Among 123 retrospectively enrolled subjects, 6-21 years age, 79.7% males, 52% were obese. Median (range) Body Mass Index Z score was +2.35 (1.67-4.43) for obese and +0.68 (-2.48-1.63) for non-obese. Subjects with obesity had higher LV mass indexed^2.7 (LVMI^2.7 ) compared with non-obese (P < 0.001). Lower global longitudinal strain (GLS) (P = 0.012), global circumferential strain (GCS) (P = 0.004), average longitudinal strain rate (P = 0.002) and average circumferential strain rate (P < 0.001) were seen in subjects with obesity; no difference was noted in arterial elastance, LV end systolic elastance and V-A. Increased LVMI^2.7 , decreased GLS, GCS, average longitudinal strain rate, average circumferential strain rate and maintained V-A were noted in the multivariate analysis between subgroups.

CONCLUSIONS

Obesity causes alterations in myocardial mechanics with preserved V-A in children. These findings may aid intervention in preventing the long-term cadiovascular effects of obesity.

An Observational Epidemiological Study of Exercise-induced Rhabdomyolysis Causing Acute Kidney Injury: A Single-center Experience

Exercise-induced rhabdomyolysis (EIR) is an uncommon cause of severe rhabdomyolysis and a very rare cause of acute kidney injury (AKI). A prospective observational study of 25 patients diagnosed with EIR was conducted in a multispecialty hospital in Dubai, from 2009 to 2015. Five out of 25 patients experienced AKI necessitating temporary renal replacement therapy. The initial presentation, biochemical parameters, and clinical course of patients were monitored, to understand epidemiology and risk factors for the development of AKI. There was male preponderance (4 out of 5 patients), higher rate of systemic symptoms (all 5 patients) versus 60% in NRAKI), oligo-anuria (all 5 patients), compartment syndrome (3 out \of 5) and severe dehydration seen in patients with RAKI group. On laboratory evaluation, there was higher rise in creatinine kinase (CK) enzyme, serum and urine myoglobin levels impaired renal function on presentation, hyperuricemia, high D-dimer level, PCV of more than 55%, found to be associated with RAKI as compared to NRAKI group. Hematuria by positive urine dipstick with absent red blood cells on urinalysis, is an insensitive tool as was present in only 62% and 43% of RAKI and NRAKI groups, respectively. It was also observed that delayed pesentation for medical care, metabolic acidosis, were commonly associated with AKI. All patients with RAKI required RRT for a comparable period of time (3-4 weeks). In all of them, no deterioration or relapse reported on follow-up of 3 months.

An Observational Epidemiological Study of Exercise-induced Rhabdomyolysis Causing Acute Kidney Injury: A Single-center Experience

Exercise-induced rhabdomyolysis (EIR) is an uncommon cause of severe rhabdomyolysis and a very rare cause of acute kidney injury (AKI). A prospective observational study of 25 patients diagnosed with EIR was conducted in a multispecialty hospital in Dubai, from 2009 to 2015. Five out of 25 patients experienced AKI necessitating temporary renal replacement therapy. The initial presentation, biochemical parameters, and clinical course of patients were monitored, to understand epidemiology and risk factors for the development of AKI. There was male preponderance (4 out of 5 patients), higher rate of systemic symptoms (all 5 patients) versus 60% in NRAKI), oligo-anuria (all 5 patients), compartment syndrome (3 out \of 5) and severe dehydration seen in patients with RAKI group. On laboratory evaluation, there was higher rise in creatinine kinase (CK) enzyme, serum and urine myoglobin levels impaired renal function on presentation, hyperuricemia, high D-dimer level, PCV of more than 55%, found to be associated with RAKI as compared to NRAKI group. Hematuria by positive urine dipstick with absent red blood cells on urinalysis, is an insensitive tool as was present in only 62% and 43% of RAKI and NRAKI groups, respectively. It was also observed that delayed pesentation for medical care, metabolic acidosis, were commonly associated with AKI. All patients with RAKI required RRT for a comparable period of time (3-4 weeks). In all of them, no deterioration or relapse reported on follow-up of 3 months.

Thioctic acid in oral submucous fibrosis (India's disease) - A better tomorrow

Oral submucous fibrosis (OSMF), because of its common occurrence in Indian population is known as India's disease. Regardless of diagnostic and therapeutic developments, oral potentially malignant disorders (PMD) and cancers are disseminating at a distressing rate. There is this prerequisite for unrelenting determination to find out apt treatment options so that malignant transformation may be prevented and more so the prevailing morbidity and mortality. Considering the frequency with which oral submucous fibrosis undergoes malignant transformation with free radicals playing a major part, the role of antioxidants in general and thioctic acid also known as alpha lipoic acid (ALA) in particular need to be studied in these individuals. Previous few studies indicated the use of alpha lipoic acid in oral submucous fibrosis patients leading to improvement in signs and symptoms. So, it led us to set forth and propose probable role of thioctic acid in improving symptoms in these patients. As oral submucous fibrosis poses as a threat with its various signs and symptoms and as a potentially malignant disorder as well as considering the role of free radicals in malignant transformation, we proposed the possible mechanisms behind the commonest signs and symptoms in oral submucous fibrosis and role of alpha lipoic acid in managing these signs and symptoms.

Sustained Rhythmic Brain Activity Underlies Visual Motion Perception in Zebrafish

Following moving visual stimuli (conditioning stimuli, CS), many organisms perceive, in the absence of physical stimuli, illusory motion in the opposite direction. This phenomenon is known as the motion aftereffect (MAE). Here, we use MAE as a tool to study the neuronal basis of visual motion perception in zebrafish larvae. Using zebrafish eye movements as an indicator of visual motion perception, we find that larvae perceive MAE. Blocking eye movements using optogenetics during CS presentation did not affect MAE, but tectal ablation significantly weakened it. Using two-photon calcium imaging of behaving GCaMP3 larvae, we find post-stimulation sustained rhythmic activity among direction-selective tectal neurons associated with the perception of MAE. In addition, tectal neurons tuned to the CS direction habituated, but neurons in the retina did not. Finally, a model based on competition between direction-selective neurons reproduced MAE, suggesting a neuronal circuit capable of generating perception of visual motion.

Fetal myocardial deformation in maternal diabetes mellitus and obesity

OBJECTIVE

Experimental evidence suggests that changes in the fetal myocardium result from intrauterine effects of maternal diabetes mellitus and obesity. The aim of this study was to assess fetal cardiac function using two-dimensional speckle-tracking echocardiography to determine the effects of maternal diabetes and obesity on the fetal myocardium.

METHODS

Comparative cross-sectional evaluation of myocardial function in fetuses of mothers with diabetes mellitus (FDM) or obesity (FO) and normal gestational age-matched control fetuses (FC) was performed using two-dimensional speckle-tracking echocardiography at two centers.

RESULTS

In total, 178 fetuses (82 FDM, 26 FO and 70 FC) met the enrolment criteria. Mean gestational age at assessment was similar among groups: 25.3 ± 5.1 weeks for FDM, 25.0 ± 4.6 weeks for FO and 25.1 ± 4.9 weeks for FC. Mean maternal body mass index was significantly higher in FDM and FO groups compared with the FC group. Statistically significant differences in fetal cardiac function were detected between FDM and FC for global longitudinal strain (mean ± SD, -21.4 ± 6.5% vs -27.0 ± 5.2%; P < 0.001), global circumferential strain (mean ± SD, -22.6 ± 6.5% vs -26.2 ± 6.8%; P = 0.002), average longitudinal systolic strain rate (median, -1.4 (interquartile range (IQR), -1.7 to -1.1)/s vs -1.6 (IQR, -2.0 to -1.4)/s; P = 0.001) and average circumferential systolic strain rate (median, -1.4 (IQR, -1.9 to -1.1)/s vs -1.6 (IQR, -2.1 to -1.3)/s; P = 0.006). Cases of non-obese FDM also had abnormal strain parameters compared with FC. Global longitudinal strain (mean ± SD, -21.1 ± 7.5%) and average circumferential systolic strain rate (median, -1.3 (IQR, -1.8 to -1.1)/s) were significantly lower in FO compared with FC.

CONCLUSIONS

Unfavorable changes occur in the fetal myocardium in response to both maternal diabetes mellitus and obesity. The long-term prognostic implications of these changes require further study. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

A Study of Microalbuminuria (MAU) and Advanced Glycation End Products (AGEs) Levels in Diabetic and Hypertensive Subjects

The prevalence of non-communicable diseases like diabetes mellitus (DM) and hypertension (HTN) is growing worldwide. Both lead to nephropathy if not controlled effectively. Microalbuminuria (MAU) is recognized as an early predictor for nephropathy. Additionally, the timely detection of advanced glycation end products (AGEs) is also considered to be an important prognostic factor for diabetic nephropathies. Hence, screening for the early detection of MAU and AGEs would be an useful and relatively inexpensive laboratory test for early clinical diagnosis for the incidence of nephropathy in these diseases. This study was conducted in DM, HTN and pregnancy induced hypertensive (PIH) subjects. MAU and N^ε-Carboxymethyllysine (CML) levels were estimated by in-house RIA kits in the patient groups and controls, while the total AGEs level in serum was determined by ELISA. The levels of MAU, CML and AGE-BSA were observed to be significantly higher in DM, HTN and PIH subjects compared to controls (p < 0.001). Increased serum CML and AGEs levels in DM, HTN and PIH subjects indicated ongoing glycemic damage and their susceptibility to develop renal complications.

A source to deliver mesoscopic particles for laser plasma studies

Intense ultrashort laser produced plasmas are a source for high brightness, short burst of X-rays, electrons, and high energy ions. Laser energy absorption and its disbursement strongly depend on the laser parameters and also on the initial size and shape of the target. The ability to change the shape, size, and material composition of the matter that absorbs light is of paramount importance not only from a fundamental physics point of view but also for potentially developing laser plasma sources tailored for specific applications. The idea of preparing mesoscopic particles of desired size/shape and suspending them in vacuum for laser plasma acceleration is a sparsely explored domain. In the following report we outline the development of a delivery mechanism of microparticles into an effusive jet in vacuum for laser plasma studies. We characterise the device in terms of particle density, particle size distribution, and duration of operation under conditions suitable for laser plasma studies. We also present the first results of x-ray emission from micro crystals of boric acid that extends to 100 keV even under relatively mild intensities of 10¹⁶ W/cm².

The influence of cemented femoral stem choice on the incidence of revision for periprosthetic fracture after primary total hip arthroplasty

Aims

Periprosthetic fracture (PF) after primary total hip arthroplasty (THA) is an uncommon but potentially devastating complication. This study aims to investigate the influence of cemented stem designs on the risk of needing a revision for a PF.

Patients and Methods

We analysed data on 257 202 primary THAs with cemented stems and 390 linked first revisions for PF recorded in the National Joint Registry (NJR) of England, Wales and Northern Ireland to determine if a cemented femoral stem brand was associated with the risk of having revision for a PF after primary THA. All cemented femoral stem brands with more than 10 000 primary operations recorded in the NJR were identified. The four most commonly used cemented femoral stems were the Exeter V40 (n = 146 409), CPT (n = 24 300), C-Stem (n = 15 113) and Charnley (n = 20 182). We compared the revision risk ratios due to PF amongst the stems using a Poisson regression model adjusting for patient factors. Compared with the Exeter V40, the age, gender and ASA grade adjusted revision rate ratio was 3.89 for the cemented CPT stem (95% confidence interval (CI) 3.07 to 4.93), 0.89 for the C-Stem (95% CI 0.57 to 1.41) and 0.41 for the Charnley stem (95% CI 0.24 to 0.70).

Conclusions

The limitations of the study include incomplete data capture, analysis of only PF requiring revision and that observation does not imply causality. Nevertheless, this study demonstrates that the choice of a cemented stem may influence the risk of revision for PF. Cite this article: Bone Joint J 2016;98-B:1347–54.

Risk factors for intramedullary nail breakage in proximal femoral fractures: a 10-year retrospective review

INTRODUCTION Intramedullary nailing is a common treatment for proximal femoral fractures. Fracture of the nail is a rare but devastating complication that exposes often frail patients to complex revision surgery. We investigated which risk factors predict nail failure. METHODS We reviewed all cases of nail breakage seen over a 10-year period in a single busy trauma unit; 22 nail fractures were seen in 19 patients. Comparison was made with a group of 209 consecutive patients who underwent intramedullary fixation of a proximal femur fracture with no nail breakage over a 2-year period. RESULTS In the fractured nail group, mean age was 70.4 years (range 55-88 years).The mean time to fracture was 10 months (range 2.5-23 months). Logistical regression was used to show that low American Society of Anesthesiologists (ASA) score, subtrochanteric fracture and pathological fracture were independent risk factors for nail fracture. CONCLUSIONS Young patients with a low ASA score are at highest risk of nail breakage. We advise close follow-up of patients with these risk factors until bony union has been achieved. In addition, there may be merit in considering other treatment options, such as proximal femoral replacement, especially for those with pathological fracture with a good prognosis.

The clinical utility of genetic testing of tissues from pregnancy losses

OBJECTIVE

To map the current testing being undertaken following pregnancy loss across the UK and to examine the clinical utility in terms of identifying a cause for the loss and in identifying couples at risk of an unbalanced liveborn child.

DESIGN

Retrospective audit.

SETTING

UK, for the year 2014.

POPULATION

An audit of 6465 referrals for genetic testing of tissue samples following pregnancy loss.

METHODS

Data were obtained by questionnaire from 15 UK regional genetics laboratories.

MAIN OUTCOME MEASURES

Data were analysed with respect to gestational age, the presence of identified fetal anomalies, methodologies used, abnormality rates and the presence of a parental balanced rearrangement.

RESULTS

Of 6465 referrals a genetic cause was identified in 22% of cases (before 12 weeks' gestation, in 47%; at 12-24 weeks, in 14%; after 24 weeks, in 6%). In 0.4% of cases a balanced parental rearrangement was identified where there was a risk of an affected liveborn child in a future pregnancy. Eighty percent of genetic imbalances identified were aneuploidy or triploidy and could be identified by quantitative fluorescence polymerase chain reaction alone. There was significant variation across the UK in acceptance criteria, testing strategies and thus level of resolution of testing.

CONCLUSIONS

Genetic testing of tissues following pregnancy loss identifies a probable cause of fetal demise in 22% of cases, but it is of low clinical utility in identifying couples at risk of a future unbalanced liveborn child. A comprehensive multidisciplinary review is needed to develop proposals for an affordable and equitable service.

TWEETABLE ABSTRACT

UK audit of genetic testing of fetal loss shows variation in access to and resolution of analysis.

Outcome of operable oral cavity cancer and impact of maintenance metronomic chemotherapy: A retrospective study from rural India

BACKGROUND

Oral cavity cancer is the most common cancer among rural India. There is a paucity of data for outcomes of operable oral cavity cancer from rural India. Use of maintenance metronomic may delay or avoid relapse.

AIM

To evaluate outcomes of operable oral cavity carcinoma and evaluate impact of maintenance metronomic chemotherapy.

OBJECTIVES

To evaluate disease-free survival (DFS), overall survival (OS), and factors affecting the outcome in operable oral cavity cancer.

MATERIALS AND METHODS

Data of patients diagnosed with oral cavity cancer registered between May 2008 and May 2014 were retrieved. Only those patients with operable oral cavity cancer and upfront definitive surgery were included in the study. Demographic profile, stage, tobacco consumption, adjuvant therapy, and pattern of failure were collected. Kaplan-Meir survival analysis was used to determine DFS and OS. Log-rank test was used to evaluate factors affecting outcome.

RESULTS

Median follow-up is 24 months. Out of 335 patients, 225 (67%) had advanced operable cancer with 42/225 (18%) and 183/225 (82%) as Stages III and IVA, respectively. Buccal mucosa was the most common subsite (178/335, 53%) followed by tongue (63/335, 19%). Ninety-two percent patients were addicted to smokeless tobacco, whereas 27% were smokers. Median DFS is 13 months with 2 years relative DFS 32%. Median OS is 30 months, with 2 years OS of 54%. Metronomic adjuvant oral chemotherapy was given in 130/225 (58%); Stage III and IVA patients with median of 14 months (3-18 months). Use of metronomic chemotherapy improved DFS (8 vs. 14 months, P = 0.22) and OS (14 vs. 26 months, P = 0.04).

CONCLUSION

Oral cavity cancer is a major health care problem in rural India. Presentation at advanced stage leads to suboptimal outcomes. Benefit of metronomic maintenance chemotherapy in locally advanced oral cavity needs to be further evaluated prospectively.

Reasons why patients fail screening in Indian breast cancer trials

Introduction:

An increased number of screen failure patients in a clinical trial increases time and cost required for the recruitment. Assessment of reasons for screen failure can help reduce screen failure rates and improve recruitment.

Materials and Methods:

We collected retrospective data of human epidermal growth factor receptor (HER2) positive Indian breast cancer patients, who failed screening for phase 3 clinical trials and ascertained their reasons for screen failure from screening logs. Statistical comparison was done to ascertain if there are any differences between private and public sites.

Results:

Of 727 patients screened at 14 sites, 408 (56.1%) failed screening. The data on the specific reasons for screen failures was not available at one of the public sites (38 screen failures out of 83 screened patients). Hence, after excluding that site, further analysis is based on 644 patients, of which 370 failed screening. Of these, 296 (80%) screen failure patients did not meet selection criteria. The majority -266 were HER2 negative. Among logistical issues, 39 patients had inadequate breast tissue sample. Sixteen patients withdrew their consent at private sites as compared to six at public sites. The difference between private and public sites for the above three reasons was statistically significant.

Conclusion:

Use of prescreening logs to reduce the number of patients not meeting selection criteria and protocol logistics, and patient counseling to reduce consent withdrawals could be used to reduce screen failure rate.

Note: Real time optical sensing of alpha-radiation emitting radioactive aerosols based on solid state nuclear track detector

A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO3)4 ⋅ 5H2O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

Thoracoscopic and endovascular management of retained haemothoarx associated with an intercostal artery pseudoaneurysm

Intercostal artery pseudoaneurysm (IAP) is a rare entity and may complicate a percutaneous intervention through an intercostal space or follow thoracic trauma. Its rupture into the pleural space can give rise to haemothorax, which if untreated may lead to a retained haemothorax (RH). Traditionally both the IAP and the RH are managed by a thoracotomy. We report a patient who developed an IAP with haemothorax following a trauma. The diagnosis was established by computed tomography. The patient was treated by endovascular embolisation of the IAP followed by thoracoscopic decortications of the RH.

DSPP contains an IRES element responsible for the translation of dentin phosphophoryn

The major phosphoprotein in dentin is the aspartic acid and serine-rich protein called dentin phosphophoryn (DPP). DPP appears to be synthesized as a part of a larger compound protein, dentin sialophosphoprotein (DSPP). DSPP has never been isolated or detected in dentin extracts. It is now evident that DSPP is a chimeric protein composed of 3 parts: dentin sialoprotein (DSP), DPP, and dentin glycoprotein (DGP). Previous reports have suggested that the BMP1 protease is responsible for processing DSPP. However, unequal amounts of these products are present in the dentin matrix. Here, we provide evidence for an internal ribosome entry site in the DSPP gene that directs the synthesis of DPP. This mechanism would account for unequal amounts of intracellular DSP and DPP. The internal ribosomal entry site (IRES) activity varied in different cell types, suggesting the presence of additional regulatory elements during the translational regulation of DPP. Further, we provide evidence that DPP is transported to the extracellular matrix (ECM) through exosomes. Using tissue recombination and lentivirus-mediated gain-of-function approaches, we also demonstrate that DPP is essential for the formation of well-defined tooth structures with mineralized dentin matrix.

Development of a monoclonal antibody-based flow-through immunoassay (FTA) for detection of white spot syndrome virus (WSSV) in black tiger shrimp Penaeus monodon

A flow-through immunoassay (FTA), an improved version of immunodot, was developed using a nitrocellulose membrane baked onto adsorbent pads enclosed in a plastic cassette to detect white spot syndrome virus (WSSV) in shrimp. Sharp purple dots developed with WSSV against the white background of the nitrocellulose membrane. The detection limits of WSSV by the FTA and immunodot were 0.312 and 1.2 μg mL(-1) crude WSSV protein, respectively. The FTA could be completed in 8-10 min compared with 90 min for immunodot. The FTA was 100 times more sensitive than 1-step polymerase chain reaction (PCR) and in between that of the 1- and 2-step PCR protocol recommended by the Office of International Epizootics (OIE). In experimental, orally infected shrimp post-larvae, WSSV was first detected 14, 16 and 18 h post-infection (hpi) by FTA, immunodot and one-step PCR, respectively. The FTA detected WSSV 2 and 4 h earlier than immunodot and one-step PCR, respectively. The FTA was more sensitive (25/27) than one-step PCR (23/27) and immunodot (23/27) for the detection of WSSV from white spot disease outbreak ponds. The reagent components of the FTA were stable giving expected results for 6 m at 4-8 °C. The FTA is available as a rapid test kit called 'RapiDot' for the early detection of WSSV under field conditions.

Structure prediction of binary pernitride MN2 compounds (M=Ca, Sr, Ba, La, and Ti)

Metal-pernitride compounds belong to a class of chemical systems in which both the complex ions and the non-bonding electrons may play roles in the formation of their modified crystalline structures. To investigate this issue, the energy landscapes of pernitrides of metals with different maximum valence (M=Ca, Sr, Ba, La, and Ti) were globally explored on the ab initio level at standard and high pressures, thereby yielding possible (meta)stable modifications in these systems together with information on how the landscape changed as function of the valence of the metal cation. For all of the systems in which no compounds had been synthesized so far, we predicted the existence of kinetically stable modifications that should, in principle, be experimentally accessible. In particular, TiN2 should crystallize in a new structure type, TiN2-I.

Truncated VP28 as oral vaccine candidate against WSSV infection in shrimp: an uptake and processing study in the midgut of Penaeus monodon

Several oral vaccination studies have been undertaken to evoke a better protection against white spot syndrome virus (WSSV), a major shrimp pathogen. Formalin-inactivated virus and WSSV envelope protein VP28 were suggested as candidate vaccine components, but their uptake mechanism upon oral delivery was not elucidated. In this study the fate of these components and of live WSSV, orally intubated to black tiger shrimp (Penaeus monodon) was investigated by immunohistochemistry, employing antibodies specific for VP28 and haemocytes. The midgut has been identified as the most prominent site of WSSV uptake and processing. The truncated recombinant VP28 (rec-VP28), formalin-inactivated virus (IVP) and live WSSV follow an identical uptake route suggested as receptor-mediated endocytosis that starts with adherence of luminal antigens at the apical layers of gut epithelium. Processing of internalized antigens is performed in endo-lysosomal compartments leading to formation of supra-nuclear vacuoles. However, the majority of WSSV-antigens escape these compartments and are transported to the inter-cellular space via transcytosis. Accumulation of the transcytosed antigens in the connective tissue initiates aggregation and degranulation of haemocytes. Finally the antigens exiting the midgut seem to reach the haemolymph. The nearly identical uptake pattern of the different WSSV-antigens suggests that receptors on the apical membrane of shrimp enterocytes recognize rec-VP28 efficiently. Hence the truncated VP28 can be considered suitable for oral vaccination, when the digestion in the foregut can be bypassed.

Evaluation of microvascular density in Barrett's associated neoplasia

Angiogenesis has an important role in the carcinogenesis of esophageal adenocarcinoma, however, the diagnostic and prognostic utility of microvascular density counts have not been clinically established. The aim of this study is to assess the correlation between microvascular density and disease progression of non-dysplastic Barrett's esophagus, low-grade dysplasia, high-grade dysplasia and invasive carcinoma in the superficial aspects of the tissue. Archival histological specimens from two referral centers for Barrett's esophagus and esophageal cancer were selected for review. A total of 160 regions marked according to histological grade were assessed with digitally interactive software to measure microvascular density. This was quantified in three levels: 0-50, 50-100 and 100-150 μm. In the areas of gastric cardia, Barrett's esophagus, low-grade dysplasia, high-grade dysplasia and cancer, microvascular density was significantly different (P<0.0001) among the five groups in the most superficial 150 μm of the mucosa. Furthermore, when examining the pairwise difference between the groups, there was a significant difference between cancer and each of the lower grades of histology (P<0.05) and between high-grade dysplasia and each of the lower grades of histology (P<0.05). These statistically significant differences were preserved in examining the depth at the most superficial 50 μm. We have used digital pathology to demonstrate a significant and stepwise increase in microvascular density, which supports the hypothesis that angiogenesis has a key role in Barrett's carcinogenesis. Furthermore, the differences in the most superficial mucosal layers are consistent with findings of increased vascularity by depth-restricted imaging modalities.

The use of a virtual learning environment in promoting virtual journal clubs and case-based discussions in trauma and orthopaedic postgraduate medical education: the Leicester experience

The use of journal clubs and, more recently, case-based discussions in order to stimulate debate among orthopaedic surgeons lies at the heart of orthopaedic training and education. A virtual learning environment can be used as a platform to host virtual journal clubs and case-based discussions. This has many advantages in the current climate of constrained time and diminishing trainee and consultant participation in such activities. The virtual environment model opens up participation and improves access to journal clubs and case-based discussions, provides reusable educational content, establishes an electronic record of participation for individuals, makes use of multimedia material (including clinical imaging and photographs) for discussion, and finally, allows participants to link case-based discussions with relevant papers in the journal club. The Leicester experience highlights the many advantages and some of the potential difficulties in setting up such a virtual system and provides useful guidance for those considering such a system in their own training programme. As a result of the virtual learning environment, trainee participation has increased and there is a trend for increased consultant input in the virtual journal club and case-based discussions. It is likely that the use of virtual environments will expand to encompass newer technological approaches to personal learning and professional development.

Pediatric spinal schwannomas: An institutional study

OBJECTIVE

The objective was to analyze the demography, clinical presentation, and management of spinal intradural schwannomas in pediatric population.

MATERIALS AND METHODS

This retrospective study includes 21 pediatric patients (under 18 years of age) who underwent surgery for spinal intradural schwannomas from January 1998 to April 2008. The medical records were reviewed retrospectively and the information regarding clinical presentation, tumor location, operative findings, and postoperative status and functional outcome were analyzed.

RESULTS

A total of 21 patients (14 females and 7 males) were operated for spinal schwannomas. Six patients had associated neurofibromatosis (five were NF I and one was NF II) at presentation. The most common presenting symptom was progressive myelopathy (86%). The tumor location was either cervical or dorsal in 18 cases. All patients underwent surgery. Gross total excision was achieved in 20 cases. The median follow-up was 38 months. All the patients had neurological improvement in both power and bladder symptoms.

CONCLUSION

Pediatric spinal neurofibromas/schwannomas are an uncommon but completely treatable group of tumors. Complete surgical excision gives excellent outcome.

The effects of chemokine, adhesion and extracellular matrix molecules on binding of mesenchymal stromal cells to poly(l-lactic acid)

BACKGROUND AIMS

Mesenchymal stromal cells (MSC) are pluripotent adult stem cells capable of osteogenesis and chondrogenesis to form bone and cartilage. This characteristic gives them the potential for bone and cartilage regeneration. Synthetic polymers have been studied to examine whether they could be used as a scaffold for tissue engineering. In the current study a two-dimensional (2-D) poly(l-lactic acid) (PLLA) scaffold was treated with chemokine, adhesion and extracellular matrix molecules with the aim of using biologic molecules to improve the attachment of human MSC.

METHODS

MSC were isolated from human bone marrow and applied to a 2-D PLLA scaffold. Chemokines ligand (CXCL12 and CXCL13), adhesion molecules [P-selectin, vascular cell adhesion molecule (VCAM)-1 and heparin] and extracellular matrix molecules (fibronectin and type IV collagen) were coated on the scaffold and their effects on the number of MSC that adhered were recorded.

RESULTS

When used alone CXCL12 and CXCL13 enhanced MSC adhesion, as did VCAM-1, P-selectin, fibronectin and collagen, but not heparin. The effects of VCAM-1, P-selectin and heparin were enhanced by the addition of CXCL12. Incubation of MSC with antibodies to integrins α4 and α5β1 inhibited their adhesion to VCAM-1 and fibronectin-treated PLLA respectively, suggesting that these integrins were involved in the MSC interactions.

CONCLUSIONS

The use of certain chemokines and adhesion and extracellular matrix molecules, alone or in combination, is beneficial for the attachment of MSC to PLLA, and may be helpful as natural molecules in scaffolds for regenerative medicine.

Automated rodent in situ muscle contraction assay and myofiber organization analysis in sarcopenia animal models

Age-related sarcopenia results in frailty and decreased mobility, which are associated with increased falls and long-term disability in the elderly. Given the global increase in lifespan, sarcopenia is a growing, unmet medical need. This report aims to systematically characterize muscle aging in preclinical models, which may facilitate the development of sarcopenia therapies. Naïve rats and mice were subjected to noninvasive micro X-ray computed tomography (micro-CT) imaging, terminal in situ muscle function characterizations, and ATPase-based myofiber analysis. We developed a Definiens (Parsippany, NJ)-based algorithm to automate micro-CT image analysis, which facilitates longitudinal in vivo muscle mass analysis. We report development and characterization of translational in situ skeletal muscle performance assay systems in rat and mouse. The systems incorporate a custom-designed animal assay stage, resulting in enhanced force measurement precision, and LabVIEW (National Instruments, Austin, TX)-based algorithms to support automated data acquisition and data analysis. We used ATPase-staining techniques for myofibers to characterize fiber subtypes and distribution. Major parameters contributing to muscle performance were identified using data mining and integration, enabled by Labmatrix (BioFortis, Columbia, MD). These technologies enabled the systemic and accurate monitoring of muscle aging from a large number of animals. The data indicated that longitudinal muscle cross-sectional area measurement effectively monitors change of muscle mass and function during aging. Furthermore, the data showed that muscle performance during aging is also modulated by myofiber remodeling factors, such as changes in myofiber distribution patterns and changes in fiber shape, which affect myofiber interaction. This in vivo muscle assay platform has been applied to support identification and validation of novel targets for the treatment of sarcopenia.

Expression pattern and prognostic significance of IGFBP isoforms in anaplastic astrocytoma

The role of insulin-like growth factors and their regulatory proteins (IGFBP isoforms) in gliomas, particularly glioblastoma, has been a subject of active research in recent years. There is paucity of literature on their expression and impact on clinical outcome in anaplastic astrocytomas. To evaluate the expression patterns of IGFBP isoforms in anaplastic astrocytoma and correlate with clinical outcome, a retrospective study of 53 adult patients operated for supratentorial lobar anaplastic astrocytoma was performed. The protein expression of IGFBP isoforms (IGFBP-2, -3, -5 and -7), was studied by immunohistochemistry on all samples. The patients were followed up and outcome was documented. The median age at presentation in the present study was 35 years. The pattern of staining was intra cytoplasmic, homogenous and diffuse for IGFBP-2, -3 and -5 and granular for IGFBP-7. IGFBP-2 expression was significantly low in anaplastic astrocytoma as compared to other isoforms (P < 0.001). IGFBP-3 expression was higher than the other isoforms. However, its' expression correlated with favorable overall survival and demonstrated a trend towards significance on univariate analysis. The present study is the first of its kind to describe comprehensively the pattern of expression of IGFBP isoforms (IGFBP-2, -3, -5 and -7) in anaplastic astrocytomas. IGFBP-2 and IGFBP-3 expression patterns and correlation to prognosis were distinct in anaplastic astrocytoma patients, contradictory to what has been reported in glioblastoma, thus giving further evidence that anaplastic astrocytomas are molecularly distinct from glioblastoma.