Evaluation of a portable assembly catheter simulator using a 3D-printed heart model for percutaneous transvenous mitral commissurotomy in developing countries: Catheter simulator for PTMC.

AIMS: We developed a catheter simulator for percutaneous transvenous mitral commissurotomy (PTMC) based on the data from a patient with mitral valve stenosis. The simulator has the following characteristics: 1) the simulator is portable and easy to assemble and disassemble, 2) the cardiac portion is created using a 3D-printer, based on patient computed tomography data, 3) the simulator uses a foot-operated water pump to create pulsatile flow, and 4) the fossa ovalis in the atrial septum of the heart model is made of a thin polyurethane membrane and is interchangeable. We aimed to assess the effectiveness of this novel simulator for training in PTMC using the Inoue balloon in developing countries. METHODS AND RESULTS: We used this simulator for training in the National Institute of Cardiovascular Diseases in Bangladesh (13 physicians), and in Kenyatta National Hospital in Kenya (11 physicians). The effectiveness of training was evaluated by questionnaire and the procedure time in simulation. The questionnaire obtained from the trainees showed that the model scored 4.7±0.5 for realism, utility of pulsatile flow scored 4.7±0.5, simulator utility scored 4.9±0.3, and the effect of training on PTMC performance scored 4.9±0.5. The procedure time in simulation was shortened from 30.0±12.6 min (first time), to 23.4±11.9 min (second time) and to 20.4 ± 11.1 min (third time) (p<0.01). CONCLUSIONS: The novel portable assembly catheter simulator using a 3D-printed heart model for PTMC received positive comments and improved the skills of trainees.

Preliminary assessment of free radical scavenging, thrombolytic and membrane stabilizing capabilities of organic fractions of Callistemon citrinus (Curtis.) skeels leaves.

BACKGROUND: Callistemon citrinus (Curtis.) (Family- Myrtaceae) is a popular evergreen shrub in Bangladesh. In the present study, the leaves of this plant have been assessed comprehensively for free radical scavenging, thrombolytic and membrane stabilizing activities. METHODS: The leaves were collected, powdered and extracted with methanol. The extract was then concentrated and successively fractionated into petroleum ether, carbon tetrachloride, chloroform and aqueous soluble fractions. The extractives were investigated for free radical scavenging, thrombolytic and membrane stabilizing activities. RESULTS: In case of 1,1 diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide radical scavenging assays, the crude methanol extract of the leaves showed the highest free radical scavenging activity among the tested materials including standard ascorbic acid (p = 0.0000). Besides, this extract was also found significantly rich (p = 0.0000) in phenolics and flavonoids compared to other organic fractions. In thrombolytic study, the petroleum ether fraction exhibited significantly stronger thrombolysis (p = 0.024) than other leaf extractives but was weaker than the standard streptokinase. In membrane stabilizing assay, the activity of chloroform fraction was similar to that of standard acetylsalicylic acid (p = 1.000) in hypotonic solution induced hemolysis. However, membrane stabilization activity of this chloroform fraction was found significantly stronger than that of the standard (p = 0.0000) in heat induced hemolysis. CONCLUSION: This study has revealed the medicinal capabilities of different organic fractions of C. citrinus displaying free radical scavenging, thrombolysis and membrane stabilizing antiinflammatory potentials. Further bioactivity guided isolation is required to obtain pharmacologically secondary metabolites.

Prevalence of obesity and central obesity among adolescent girls in a district school in Bangladesh.

INTRODUCTION: The prevalence of childhood obesity has increased over the last two decades. Obesity is a major risk factor for chronic diseases and plays a central role in insulin resistance or metabolic syndrome. METHODS: The aim of the study was to assess the prevalence of obesity and abdominal obesity by means of body mass index (BMI) and waist-to-height ratio (WHtR) in adolescent girls in a district school in Bangladesh. Based on age and sex specific BMI percentiles, the students were classified as normal weight (5(th)-<85(th) percentile), overweight (85(th)-<95(th) percentiles), and obese (≥95(th) percentile). Central obesity was categorized as WHtR ≥ 0.5. Adolescent girls (aged 9-17 years) attending the sixth to twelfth grades (n = 501) in a Bengali medium school participated in the study. RESULTS: The prevalence of obesity and overweight were 23% and 14% among the girls. The prevalence of central obesity was 26%. Around 14% of girls in the normal weight group were centrally obese. There was a significant relationship between WHtR and BMI status (P = 0.0001). CONCLUSION: Our study provides evidence showing a high prevalence of overall and central obesity in adolescent girls in our population. We emphasize the need for further large scale surveillance programs and preventive strategies in our population to reduce the incidence of obesity.

Targeting the IL-6 pathway in multiple myeloma and its implications in cancer-associated gene hypermethylation.

Aberrant methylation of tumor suppressor genes (TSG) is an important epigenetic event in cancer, including multiple myeloma (MM). Interleukin-6 (IL-6), which plays a significant role in the pathogenesis of MM, also regulates DNA methylation. However, attempts to bring IL-6 blockade to the clinic have had limited success. We hypothesize that IL-6 regulation of hypermethylation may be an important pathway leading to rational chemotherapeutic/anti-IL-6 combinations. We first studied the correlation of IL-6 expression and dependence in MM cell lines: U266B1, RPMI8226, and KAS6/1. We confirmed that KAS6/1 is IL-6-dependent whereas U266B1 and RPMI8226 cells are IL-6-independent and that blocking IL-6 inhibited the growth of U266B1 (36% inhibition; p<0.05) and KAS6/1 (68% inhibition; p<0.01), but not the RPMI8226 cells. Using RT-PCR, we showed that U266B1 cells express IL-6, but RPMI8226 and KAS6/1 cells do not. This IL-6 expression pattern correlates with the anti-IL-6 inhibition findings. To correlate IL-6 sensitivity with hypermethylation of TSG, we investigated promoter methylation of CDH1 and DcR1. We found that the promoter of DcR1 and CDH1 is methylated in U266B1 cells and un-methylated in RPMI8226 cells. Furthermore, the DcR1 promoter was un-methylated in KAS6/1 cells. These data support our hypothesis that an IL-6-dependent pathway may regulate hypermethylation of TSG in MM. Newer chemotherapeutic agents that affect methylation are being studied in combination with IL-6 blockade.

Periostin induces proliferation of human autosomal dominant polycystic kidney cells through alphaV-integrin receptor.

Progressive renal enlargement due to the growth of innumerable fluid-filled cysts is a central pathophysiological feature of autosomal dominant polycystic kidney disease (ADPKD). These epithelial neoplasms enlarge slowly and damage noncystic parenchyma by mechanisms that have not been clearly defined. In a microarray analysis of cultured human ADPKD cyst epithelial cells, periostin mRNA was overexpressed 15-fold compared with normal human kidney (NHK) cells. Periostin, initially identified in osteoblasts, is not expressed in normal adult kidneys but is expressed transiently during renal development. We found periostin in cyst-lining cells in situ in the extracellular matrix adjacent to the cysts and within cyst fluid. ADPKD cells secreted periostin across luminal and basolateral plasma membranes. Periostin increased proliferation of cyst epithelial cells 27.9 +/- 3.1% (P < 0.001) above baseline and augmented in vitro cyst growth but did not affect proliferation of normal renal cells. Expression of alphaV-integrin, a periostin receptor, was ninefold higher in ADPKD cells compared with NHK cells, and antibodies that block alphaV-integrin inhibited periostin-induced cell proliferation. We conclude that periostin is a novel autocrine mitogen secreted by mural epithelial cells with the potential to accelerate cyst growth and promote interstitial remodeling in ADPKD.