Dietary Selenium (Se) and Vitamin E (V<Subscript>E</Subscript>) Supplementation Modulated Methylmercury-Mediated Changes in Markers of Cardiovascular Diseases in Rats

Epidemiological studies demonstrated that human exposure to methylmercury (MeHg) may contribute to the development and progression of metabolic and cardiovascular disorders. However, the mechanisms involved and the role of selenium (Se) and vitamin E (V_E) supplementation in modulating MeHg cardiovascular toxicities remain unclear. This study examined the effects of Se and V_E supplementation on MeHg-mediated systemic oxidative stress, antioxidant defense, inflammation, and endothelial dysfunction in an animal model. Male Sprague–Dawley rats were fed a starch-based casein diet or the same diet supplemented with 1 or 3 mg Se/kg diet and with or without 250 or 750 mg V_E/kg diet. After 28 days of dietary treatment, rats were gavaged with 0 or 3 mg MeHg/kg BW for 14 consecutive days. Results suggested that exposure to MeHg may increase the risk of cardiovascular disease by decreasing circulating paraoxonase-1 activities, increasing serum oxidized low density lipoprotein levels, and associated systemic inflammation and endothelial dysfunction as reflected by increased leukocyte counts and serum levels of intercellular adhesion molecule-1 and monocyte chemotactic protein-1. Se and V_E supplementation may either alleviate or augment the effects of MeHg, depending on their doses and combinations.     

Novel non-mulberry silk fibroin nanoparticles with enhanced activity as potential candidate in nanocarrier mediated delivery system

Silk fibroin (SF) is well known for its excellent biocompatible properties facilitating its application in the field of biomedical engineering through different biomaterial fabrications in the recent era. Here in this study, novel nanoparticles from non-mulberry SF of Antheraea assamensis were fabricated, characterized and evaluated for its applicability as nanocarrier. Fabricated nanoparticles were initially compared with prevailing SF nanoparticles from Bombyx mori. Fabricated A. assamensis silk fibroin nanoparticles (AA-SFNps) were found to be lesser in size (80–300 nm in diameter) than B. mori silk fibroin nanoparticles (BM-SFNps) (120–500 nm in diameter). When checked for stability, AA-SFNps were found to be more stable than BM-SFNps in biological media. FTIR and XRD studies revealed persistence of structural properties even after fabrication. TGA and DSC studies showed AA-SFNps to be thermally more stable than BM-SFNps without any cytotoxicity (MTT assay). On loading with model drug Doxorubicin hydrochloride (DOX), AA-SFNps exhibited an encapsulation efficiency of 94.47% with 11.81% loading of the anticancer drug. Cumulative release study revealed highest percentage release of DOX (42.1 ± 0.4%) at pH 5.2 on day 7 in comparison to pH 7.4 and 8.0. Sustained release profile of the DOX loaded AA-SFNps (AA-SFNps-DOX) was clearly reflected and it was found to be highly cytotoxic against triple negative MDA-MB-231 cells in comparison to free DOX at different time points. Overall, this study showed the efficacy of the AA-SFNps as a nanocarrier for future drug delivery applications.

Novel Antheraea assamensis silk fibroin nanoparticles (AA-SFNps) exhibiting enhanced activity as doxorubicin hydrochloride (DOX) loaded nanocarriers for future drug delivery applications.     

CdTe QD-based inhibition and reactivation assay of acetylcholinesterase for the detection of organophosphorus pesticides

An enzyme immobilized glutathione (GSH)-capped CdTe quantum dot (QD)-based fluorescence assay has been developed for monitoring organophosphate pesticides. In principle, GSH-capped CdTe QDs exhibit higher sensitivity towards H₂O₂ produced from the active enzymatic reaction of acetylcholinesterase (AChE) and choline oxidase (CHOx), which results in the fluorescence (FL) “turn-off” of the GSH-capped CdTe QDs. A “turn-on” FL of the CdTe QDs at 520 nm was recovered in the presence of organophosphate (OP). The FL changes of the GSH-capped CdTe QD/AChE/CHOx biosensor reasonably correspond to the amount of OP pesticides. The detection limit of the CdTe/AChE/CHOx biosensor towards paraoxon, dichlorvos, malathion and triazophos was 1.62 × 10⁻¹⁵ M, 75.3 × 10⁻¹⁵ M, 0.23 × 10⁻⁹ M and 10.6 × 10⁻¹² M, respectively. The GSH-capped CdTe QDs/AChE/CHOx biosensor was applied as a FL nanoprobe for assaying the enzymatic activity of AChE. The inhibited AChE was reactivated up to 94% using pyridine oximate (2-PyOx⁻), and functionalized pyridinium oximates (4-C₁₂PyOx⁻ and 4-C₁₈PyOx⁻) of varying chain lengths. It was found that the reactivation potency of the tested oximes varied with the chain length of the oximes. This biosensing system offers the promising benefit for the determination of the OP pesticides in food, water and environmental samples.

An enzyme immobilized glutathione (GSH)-capped CdTe quantum dot (QD)-based fluorescence assay has been developed for monitoring organophosphate pesticides.     

Pulmonary embolectomy with use of pediatric bronchoscope for the detection of residual emboli: an innovative surgical technique

Pulmonary embolectomy in the treatment of massive pulmonary embolus has been in doubt since the introduction of thrombolytic therapy. Recent indications for surgical intervention are- contraindication to thrombolysis, failed medical treatment and severe Right Ventricular (RV) dysfunction. A 54-year male came to us with complaints of palpitation, tachypnea and repeated syncope . Transthoracic echocardiography and Computed Tomography pulmonary angiogram demonstrated- Biatrial mass with right atrial mass extending into right ventricle and main pulmonary artery. Pulmonary embolectomy was performed. Residual emboli of bilateral pulmonary arteries were detected with a fiberoptic pediatric bronchoscope and removed. Bronchoscopic evaluation appears to be safe and useful for direct visual detection of emboli.     

Swan-Ganz entrapment during cardiac surgery – a case report

Inability to withdraw a Swan-Ganz catheter as a result of its intracardiac entrapment is a rare but serious complication. In a normal intracardiac course, the catheter tends to rest against the antero-lateral wall of the right atrium where the catheter may be caught by the suture during cannulation for Cardiopulmonary Bypass (CPB). Entrapment of a Swan-Ganz catheter by the left atriotomy suture is described in this case report.     

Reduction in augmentation index after successful renal transplantation

Background

Patients of end stage renal disease (ESRD) have an increased risk of cardiovascular events. Arterial stiffness is an established independent predictor of cardiovascular morbidity and mortality in ESRD patients. Carotid femoral pulse wave velocity (c-f PWV) and augmentation index (AI) are the indices which are used for the noninvasive assessment of arterial stiffness. Renal transplantation (RT) as a treatment modality in ESRD patients is associated with improvement in cardiovascular survival. Whether this improvement is due to attenuation of arterial stiffness has been inadequately investigated. The present study was conducted in ESRD patients before and 3 months after RT to assess the reversibility of the abnormalities of vascular compliance that are known to be associated with adverse outcome.

Methods

Arterial stiffness indices (c-f PWV and AI) were measured using the principle of applanation tonometry with a SphygmoCor^® CvMS system (Atcor Medicals, Australia) in 23 ESRD patients (age: 35.9 ± 9.3 years) before and 3 months after successful RT.

Results

After transplantation, augmentation index values reduced significantly as compared to their pre-transplant values (27.7 ± 11.3 % vs. 17.1 ± 9.0 %; P < 0.0001), while the carotid femoral pulse wave velocity values did not differ significantly (8.7 ± 2.0 vs. 8.6 ± 3.2 m/s). The augmentation index was correlated with the biochemical parameters of serum creatinine (Pearson r = 0.3628; P = 0.0128) and calcium phosphate product (Pearson r = 0.3868; P = 0.0079).

Conclusions

Restoration of renal function following successful RT is associated with differential effects on the two indices of arterial stiffness. The salient finding of our study is that 3 months after transplantation, functional changes in vasculature lead to a significant reduction in the augmentation index, while the pulse wave velocity may take longer to show an improvement.