Renu Dhingra

Role of oxidative stress markers and antioxidants in the placenta of preeclamptic patients

Aim:  The present study aimed to evaluate and compare the placental variables of oxidative stress markers in preeclamptic women.

Practical guidelines for setting up neurosurgery skills training cadaver laboratory in India

Though the necessity of cadaver dissection is felt by the medical fraternity, and described as early as 600 BC, in India, there are no practical guidelines available in the world literature for setting up a basic cadaver dissection laboratory for neurosurgery skills training. Hands-on dissection practice on microscopic and endoscopic procedures is essential in technologically demanding modern neurosurgery training where ethical issues, cost constraints, medico-legal pitfalls, and resident duty time restrictions have resulted in lesser opportunities to learn. Collaboration of anatomy, forensic medicine, and neurosurgery is essential for development of a workflow of cadaver procurement, preservation, storage, dissection, and disposal along with setting up the guidelines for ethical and legal concerns.

Plastinated knee specimens: a novel educational tool.

INTRODUCTION During the routine dissection of knee joints in an anatomy dissection hall, it was observed that the specimens had deteriorated overtime, due to their repeated handling and the use of high concentrations of formalin for their fixation. In order to stop their further deterioration, we decided to plastinate these specimens. Thus, the present study was undertaken to prepare plastinated knee specimens from old embalmed cadavers and to compare them with freshly fixed, plastinated specimens. OBJECTIVES 1. To plastinate old embalmed and fresh formalin fixed knee regions.2. To demonstrate the extra and the intracapsular structures around both the plastinated knee regions.3. To compare their morphological features in terms of their colours, dilatation and flexibility. METHODS A total of 15 knee joint specimens from among fresh formalin (5-8%) fixed (group I) and old embalmed bodies (group II) were collected, washed and plastinated by using the standard S-10 silicon technique and they were compared for their colours, dilatation and flexibility. RESULTS All the plastinated specimens showed an accurate reproduction of the tissue details that were comparable to those of the natural unfixed specimens. A comparison among the two groups showed a significant difference in terms of the colour, dilatation and the flexibility of the specimens. The plastinated knee joint specimens from group I were of good quality, with negligible shrinkage, more flexibility and well preserved morphologies. CONCLUSION Plastinated knee specimens can serve as an excellent educational tool for the undergraduate and postgraduate students of anatomy, radiology and orthopaedics, as they are dry, odourless and nontoxic, with a good structural preservation and a higher instructional value. The fresh knee regions, when they were plastinated, were aesthetically superior in terms of their colours, dilatation and flexibility, thus making them ideal for teaching and hands-on experiences.

Feasibility study of a novel intraosseous device in adult human cadavers.

Background & objectives: Intraosseous (IO) access is an alternative to difficult intravenous (iv) access during emergency clinical situations. Existing IO solutions are expensive, require power supply and trained manpower; limiting their use in resource constrained settings. To address these limitations, a novel IO device has been developed. The objectives of this study were to evaluate functionality and safety of this device in adult human cadavers. Methods: The ability of the IO device to penetrate the proximal and/or distal tibia was evaluated in three adult cadavers. Subjective parameters of loss of resistance, stable needle hold, easy needle withdrawal and any damage to the device were evaluated during the study. The insertion time was the objective parameter measured. Four sets of radiographs per insertion confirmed the position of the needle and identified complications. Results: A single physician performed 12 IO access procedures using the same device. Penetration of proximal and/or distal tibia was achieved in all instances. It was successful in the first attempt in eight (66.7%) and during second attempt in the remaining. The mean time to insertion was 4.1 ± 3.1 sec. Appropriate insertion of needle in the intra-medullary space of bone was confirmed with radiological examination in 10 (83.3%) insertions. In two occasions after penetrating the cortical layer of bone, the device overshot the intra-medullary space, as detected by radiological examination. Device got bent during insertion in one instance. There was no evidence of needle breakage or bone fracture. The needle could be withdrawn effortlessly in all instances. Interpretation & conclusions: The novel IO device could successfully penetrate the adult cadaver bones in most cases. Further studies are needed to confirm these results on a large sample.

A Comparative Study of Apoptosis in Placentas of Normal and Preeclamptic Indian Pregnant Women by TUNEL Assay and M30 Immunostaining

Preeclampsia is a unique life‐threatening disorder of human pregnancy associated with the abnormal placentation caused by the inadequate trophoblastic invasion due to altered apoptosis of these cells. The aim of the present study was to assess and compare the apoptosis in trophoblastic cells in various zones (villous and extravillous) of placentas of preeclamptic and normotensive nonproteinuric pregnant women.

sFlt-1 commutes unfolded protein response into endoplasmic reticulum stress in trophoblast cells in preeclamptic pregnancies

Preeclampsia (PE) and its subtypes (early and late onset) are serious concerns all across the globe affecting about 8% of total pregnancies and accounts for approximately 60,000 deaths annually with a predominance in developing under-developed and countries. The two-stage model in the progression of this disease, deficient spiral artery remodelling and an imbalance between angiogenic (VEGF) and anti-antigenic factor(s) (sFlt-1) are well established facts pertaining to this disease. The presence of increased sFlt-1, high oxidative stress and Endoplasmic reticulum stress (ER stress) have been proposed in preeclamptic pregnancies. Recently, the role of endoplasmic reticulum stress in the onset of the variant forms of PE highlighted a new window to explore further. In our previous studies, we demonstrated that sFlt-1 can induce apoptosis and oxidative stress in trophoblast cells. However the role of sFlt-1, in inducing ER stress is not known so far. In the present study, we for the first time demonstrated significant ER stress in the placental cells (BeWo Cells) (in vitro) when exposed to sera from preeclamptic pregnancies having increased concentration of sFlt-1. The expression of ER stress markers (GRP78, eIF2α, XBP1, ATF6 and CHOP) at both transcript and protein levels were compared (between preeclamptic and normotensive non-proteinuric women) at three different time points (8h, 14h and 24hrs), analyzed and found to be significant (p<0.05). Conclusion Our results suggested that sFlt-1, released from placental cells in preeclampsia may be one of the various factors having potential to induce endoplasmic reticulum stress in BeWo cells.

Standardization of the technique of silicon injection of human cadaveric heads for opacification of cerebral vasculature in Indian conditions

A surgeons understanding of the surgical anatomy can be greatly enhanced by the dissection of preserved cadaveric specimens. A reliable and inexpensive biological model for testing and standardization of dye injection concentrations is proposed utilizing the goats head as a biological model. The first phase was concerned with standardization of the dye by titrating its concentration and injecting various amounts into cerebral vessels of a goats head until an optimal concentration had been ascertained. In the second phase, this optimum concentration of the dye was injected into four human cadaveric heads following the same technique standardized using the goats head. Upon dissecting the four cadaveric human heads which were injected with silicon dyes and preserved in 10% formalin, the vessels were all well-opacified and the brain was of near normal consistency and good for dissection, without showing any features of putrefaction. The goat model, having similar color, texture, and the handling as the cadaveric head, offers an opportunity to test indigenously manufactured polymerizing dyes in the future. This biological model, therefore, has the potential to considerably reduce the cost of cadaver preparation.

sFlt-1 (sVEGFR1) induces placental endoplasmic reticulum stress in trophoblast cell: implications for the complications in preeclampsia - an in vitro study

Background The concentration of sFlt-1, a major anti-angiogenic protein in maternal circulation has been seen to be raised in preeclamptic pregnancies. Endoplasmic reticulum (ER) stress represents one of the three (immunological, oxidative and ER stress) major stresses which placenta undergoes during pregnancies. The present study is designed to investigate the role of sFlt-1 in induction of ER stress in trophoblast cells. Materials and Methods Maternal serum levels of anti-angiogenic protein sFlt-1 and central regulator of unfolded protein response GRP78 was measured using sandwich ELISA. The expression of various ER stress markers (GRP78, eIF2α, XBP1, ATF6 and apoptotic protein CHOP) were analyzed depending on various treatments given to the trophoblast cells using Immunofluorescence, western blot and q-RT PCR. Results Increased expression of ER stress markers (GRP78, eIF2α, XBP1 ATF6 and apoptotic protein CHOP) was detected in the placental trophoblast cells treated with raised concentration of sFlt-1. Conclusion Significant upregulated expression of ER stress markers in trophoblast cells exposed with increased concentration of sFlt-1 suggested that it may be one of the anti-angiogenic factors present in maternal sera which not only contributes to oxidative stress but also may cause endoplasmic reticulum stress.