P-094 LAPAROSCOPIC VS OPEN VENTRAL HERNIA REPAIR: AN OBSERVATIONAL SINGLE CENTRE STUDY

Background

Various surgical techniques are practised to provide best possible outcome for ventral hernia patients. This study was conducted to understand the patient's perspective regarding the choice and outcome of treatment.

Aim

To determine the level of satisfaction 1 month after ventral hernia repair. To analysed various factors which affects the patient's decision regarding the choice of surgery. To compare post operative outcomes between laparoscopic and open ventral hernia repair.

Material & Methods

An observational study was conducted between January 2020 and December 2021. Total 70 patients with ventral hernia were included. Relevant data was collected and analysed using SPSS version 28.

Results

39 patients underwent open repair and 31 patients underwent laparoscopic repair. 40% patients thought that their choice is better than the other option. 18.5% patients who preferred laparoscopic surgery were scared of big incision and 5% patients opted for open surgery because of unaffordability of mesh. 11.4% patient's decision was affected by the advice from other doctors whom they may have consulted before, 2.8% patients took advise from friends and family. Almost 20% patients left the decision on the treating team. The incidence of complications was significantly less in laparoscopic repair. However, there was no significant difference in the postoperative pain, duration of hospital stay, return to activity and satisfaction at discharge. level of satisfaction at 1 month was significantly higher in the laparoscopic group compared to open group.

Conclusion

laparoscopic ventral hernia repairs should be preferred in view of fewer complications and higher satisfaction.

Functions of long non-coding RNA in Arabidopsis thaliana

A major part of the eukaryotic genome is transcribed into non-coding RNAs (ncRNAs) having no protein coding potential. ncRNAs which are longer than 200 nucleotides are categorized as long non coding RNAs (lncRNAs). Most lncRNAs are induced as a consequence of various environmental and developmental cues. Among plants, the functions of lncRNAs are best studied in Arabidopsis thaliana. In this review, we highlight the important functional roles of various lncRNAs during different stages of Arabidopsis life cycle and their response to environmental changes. These lncRNAs primarily govern processes such as flowering, seed germination, stress response, light- and auxin-regulated development, and RNA-dependent DNA methylation (RdDM). Major challenge is to differentiate between functional and cryptic transcripts. Genome editing, large scale RNAi and computational approaches may help to identify and characterize novel functional lncRNAs in Arabidopsis.

Genome-wide analysis of epigenetic and transcriptional changes associated with heterosis in pigeonpea

Hybrids are extensively used in agriculture to deliver an increase in yield, yet the molecular basis of heterosis is not well understood. Global DNA methylation analysis, transcriptome analysis and small RNA profiling were aimed to understand the epigenetic effect of the changes in gene expression level in the two hybrids and their parental lines. Increased DNA methylation was observed in both the hybrids as compared to their parents. This increased DNA methylation in hybrids showed that majority of the 24-nt siRNA clusters had higher expression in hybrids than the parents. Transcriptome analysis revealed that various phytohormones (auxin and salicylic acid) responsive hybrid-MPV DEGs were significantly altered in both the hybrids in comparison to MPV. DEGs associated with plant immunity and growth were overexpressed whereas DEGs associated with basal defence level were repressed. This antagonistic patterns of gene expression might contribute to the greater growth of the hybrids. It was also noticed that some common as well as unique changes in the regulatory pathways were associated with heterotic growth in both the hybrids. Approximately 70% and 67% of down-regulated hybrid-MPV DEGs were found to be differentially methylated in ICPH 2671 and ICPH 2740 hybrid, respectively. This reflected the association of epigenetic regulation in altered gene expressions. Our findings also revealed that miRNAs might play important roles in hybrid vigour in both the hybrids by regulating their target genes, especially in controlling plant growth and development, defence and stress response pathways. The above finding provides an insight into the molecular mechanism of pigeonpea heterosis.

Phylogenetic relationship and domain organisation of SET domain proteins of Archaeplastida

BACKGROUND

SET is a conserved protein domain with methyltransferase activity. Several genome and transcriptome data in plant lineage (Archaeplastida) are available but status of SET domain proteins in most of the plant lineage is not comprehensively analysed.

RESULTS

In this study phylogeny and domain organisation of 506 computationally identified SET domain proteins from 16 members of plant lineage (Archaeplastida) are presented. SET domain proteins of rice and Arabidopsis are used as references. This analysis revealed conserved as well as unique features of SET domain proteins in Archaeplastida. SET domain proteins of plant lineage can be categorised into five classes- E(z), Ash, Trx, Su(var) and Orphan. Orphan class of SET proteins contain unique domains predominantly in early Archaeplastida. Contrary to previous study, this study shows first appearance of several domains like SRA on SET domain proteins in chlorophyta instead of bryophyta.

CONCLUSION

The present study is a framework to experimentally characterize SET domain proteins in plant lineage.

The ASYMMETRIC LEAVES Complex Employs Multiple Modes of Regulation to Affect Adaxial-Abaxial Patterning and Leaf Complexity

Flattened leaf architecture is not a default state but depends on positional information to precisely coordinate patterns of cell division in the growing primordium. This information is provided, in part, by the boundary between the adaxial (top) and abaxial (bottom) domains of the leaf, which are specified via an intricate gene regulatory network whose precise circuitry remains poorly defined. Here, we examined the contribution of the ASYMMETRIC LEAVES (AS) pathway to adaxial-abaxial patterning in Arabidopsis thaliana and demonstrate that AS1-AS2 affects this process via multiple, distinct regulatory mechanisms. AS1-AS2 uses Polycomb-dependent and -independent mechanisms to directly repress the abaxial determinants MIR166A, YABBY5, and AUXIN RESPONSE FACTOR3 (ARF3), as well as a nonrepressive mechanism in the regulation of the adaxial determinant TAS3A. These regulatory interactions, together with data from prior studies, lead to a model in which the sequential polarization of determinants, including AS1-AS2, explains the establishment and maintenance of adaxial-abaxial leaf polarity. Moreover, our analyses show that the shared repression of ARF3 by the AS and trans-acting small interfering RNA (ta-siRNA) pathways intersects with additional AS1-AS2 targets to affect multiple nodes in leaf development, impacting polarity as well as leaf complexity. These data illustrate the surprisingly multifaceted contribution of AS1-AS2 to leaf development showing that, in conjunction with the ta-siRNA pathway, AS1-AS2 keeps the Arabidopsis leaf both flat and simple.

The ASYMMETRIC LEAVES complex maintains repression of KNOX homeobox genes via direct recruitment of Polycomb-repressive complex2

Polycomb-repressive complexes (PRCs) ensure the correct spatiotemporal expression of numerous key developmental regulators. Despite their pivotal role, how PRCs are recruited to specific targets remains largely unsolved, particularly in plants. Here we show that the Arabidopsis ASYMMETRIC LEAVES complex physically interacts with PRC2 and recruits this complex to the homeobox genes BREVIPEDICELLUS and KNAT2 to stably silence these stem cell regulators in differentiating leaves. The recruitment mechanism resembles the Polycomb response element-based recruitment of PRC2 originally defined in flies and provides the first such example in plants. Combined with recent studies in mammals, our findings reveal a conserved paradigm to epigenetically regulate homeobox gene expression during development.

Synthesis of mesoporous silica nanoparticles and drug loading of poorly water soluble drug cyclosporin A

Mesoporous silica nanoparticles (MSNs) are introduced as chemically and thermally stable nanomaterials with well-defined and controllable morphology and porosity. It is shown that these particles possess external and internal surfaces that can be selectively functionalized with multiple organic and inorganic groups. Silica nano-particles were synthesized by chemical methods from tetraethylorthosilicate (TEOS), methanol (CH3OH) and deionised water in the presence of sodium hydroxide as catalyst at 80°C temperature. The nature and morphology of particles was investigated by scanning electron microscopy (SEM), N2 adsorption/desorption method using BET instrument and X-ray diffraction (XRD). Silica nanoparticles are applicable to a wide range of therapeutic entities from small molecule to peptides and proteins including hydrophobic and hydrophilic entities. Drug loading does not require chemical modification of the molecule; there are no changes in the drug structure or activity after loading and subsequent release of the drug. Thus, well suited to solve formulation problems associated with hydrophobic drugs such as peptide and protein drugs like cyclosporine A. Silica nanoparticles improved the solubility of poorly water soluble drugs and enhanced the absorption and bioavailability of these compounds.

Genetic and epigenetic regulation of stem cell homeostasis in plants

Plants generate new organs through the activity of small populations of stem cells present in specialized niches called meristems. Stem cell homeostasis is attained by dynamic regulatory networks involving transcriptional regulators, hormones, and other intercellular signals that specify cell fate and convey positional information to the apical stem cells and the organizing center located immediately below. The balance between stem cell maintenance within the shoot apical meristem (SAM) and differentiation of cells that are displaced from the niche to form new organs involves the epigenetic silencing of stem cell regulatory genes. Recent advances have identified highly conserved chromatin remodeling factors as epigenetic regulators of stem cell fate that confer plasticity in plant development and ensure the stable inheritance of repressed expression states during organogenesis. These advances reveal that common mechanisms contribute to stem cell homeostasis in plants and animals.

Heat shock factor 1 is a key regulator of the stress response in Chlamydomonas

We report here on the characterization of heat shock factor 1 (HSF1), encoded by one of two HSF genes identified in the genome of Chlamydomonas reinhardtii. Chlamydomonas HSF1 shares features characteristic of class A HSFs of higher plants. HSF1 is weakly expressed under non-stress conditions and rapidly induced by heat shock. Heat shock also resulted in hyperphosphorylation of HSF1, and the extent of phosphorylation correlated with the degree of induction of heat shock genes, suggesting a role for phosphorylation in HSF1 activation. HSF1, like HSFs in yeasts, forms high-molecular-weight complexes, presumably trimers, under non-stress, stress and recovery conditions. Immunoprecipitation of HSF1 under these conditions led to the identification of cytosolic HSP70A as a protein constitutively interacting with HSF1. Strains in which HSF1 was strongly under-expressed by RNAi were highly sensitive to heat stress. 14C-labelling of nuclear-encoded proteins under heat stress revealed that synthesis of members of the HSP100, HSP90, HSP70, HSP60 and small HSP families in the HSF1-RNAi strains was dramatically reduced or completely abolished. This correlated with a complete loss of HSP gene induction at the RNA level. These data suggest that HSF1 is a key regulator of the stress response in Chlamydomonas.

Diabetic retinopathy is a poor predictor of type of nephropathy in proteinuric type 2 diabetic patients

BACKGROUND

Both diabetic nephropathy (DN) and nondiabetic nephropathy (NDN) are reported to occur in patients with type 2 diabetes mellitus (DM). The precise diagnosis of the type of nephropathy has obvious clinical and prognostic implication. The aim of the study was to evaluate the histologic spectrum of nephropathy in proteinuric type 2 diabetic patients and to find the correlation between type of nephropathy and diabetic retinopathy (DR).

METHODS

Twenty eight proteinuric type 2 diabetic patients were included in the study. Five patients (ADPKD 3 and chronic pyelonephritis 2) were excluded from biopsy. Percutaneous renal biopsy was carried in remaining 23 patients.

RESULTS

There was a preponderance of male (75%) and majority of the patients were in the age group of 30-78 years. Duration of diabetes ranged between 4 months to 25 years with mean +/- SD of 10.53 +/- 7.62 years. The presenting features were nephrotic syndrome 14 (60.9%), non-nephrotic proteinuria 9 (39.1%) and impaired renal function in 19 (82.6%) patients. Renal biopsy in 23 cases revealed; isolated diabetic nephropathy 13 (56.2%), NDN7 (13.43%) and 3 (13%) patients had NDN superimposed on diabetic nephropathy. Membranous nephropathy (2), focal segmental glomerulosclerosis (2), mesangiocapillary glomerulonephritis (1) were the nondiabetic glomerular disease in our type 2 diabetic patients. Chronic pyelonephritis and ischemic interstial nephropathy was the predominant tubulointerstial lesion in this study. Diabetic retinopathy (DR) observed in 12 (75%) patients with biopsy proven DN and absent in 4 (25%) patients with DN. The distribution of renal lesions in patients with DR (n = 15) showed DN in 9 (60%), NDN 3 (20%) and remaining 3 patients had combined lesions. Renal biopsy in 8 patients without DR showed typical DN in 4 (50%) and NDN in 4 (50%) patients.

CONCLUSION

This study demonstrates presence of both glomerular and tubulointerstitial lesions unrelated to diabetes (NDN) in proteinuric type 2 diabetic patients. Further presence or absence of DR was a poor predictor of diabetic nephropathy because DN was noted in 50% of patients without DR and 40% of patients with DR had non-diabetic nephropathy either alone or in combination with DN.

Analysis of chromatin structure in the control regions of the chlamydomonas HSP70A and RBCS2 genes

We have used DNaseI and micrococcal nuclease sensitivity assays to determine the chromatin structures in the control regions of the Chlamydomonas reinhardtii HSP70A and RBCS2 genes. Both genes appear to be organized into nucleosome arrays, which exhibit shorter nucleosome repeat lengths than bulk chromatin. In HSP70A we have identified up to four confined DNaseI hypersensitive sites, three of them localize to the promoter region, a fourth one to the fourth intron. Three hypersensitive sites map close to putative heat shock elements, one close to a CCAAT-box. All hypersensitive sites are located to internucleosomal linkers. Alternative nucleosome positions at half-nucleosomal phasing were constitutively detected in the HSP70A promoter region, indicating local chromatin remodelling. Upon heat shock, dramatic changes in the nucleosome structure of HSP70A were detected that particularly affected the promoter, but also a region within the fourth intron. In contrast, light induction entailed no change in HSP70A chromatin. In the RBCS2 control region we identified a strong DNaseI hypersensitive site that maps close to a CCAAT-box. This site forms the boundary of a nucleosome array with a region of approximately 700 bp apparently devoid of nucleosomes. This study demonstrates that chromatin structure may be determined readily at fairly high resolution in Chlamydomonas, suggesting this organism as a well-suited model for studying the role of chromatin structure on gene expression in photosynthetic eukaryotes.

J-domain protein CDJ2 and HSP70B are a plastidic chaperone pair that interacts with vesicle-inducing protein in plastids 1

J-domain cochaperones confer functional specificity to their heat shock protein (HSP)70 partner by recruiting it to specific substrate proteins. To gain insight into the functions of plastidic HSP70s, we searched in Chlamydomonas databases for expressed sequence tags that potentially encode chloroplast-targeted J-domain cochaperones. Two such cDNAs were found: the encoded J-domain proteins were named chloroplast DnaJ homolog 1 and 2 (CDJ1 and CDJ2). CDJ2 was shown to interact with a approximately 28-kDa protein that by mass spectrometry was identified as the vesicle-inducing protein in plastids 1 (VIPP1). In fractionation experiments, CDJ2 was detected almost exclusively in the stroma, whereas VIPP1 was found in low-density membranes, thylakoids, and in the stroma. Coimmunoprecipitation and mass spectrometry analyses identified stromal HSP70B as the major protein interacting with soluble VIPP1, and, as confirmed by cross-linking data, as chaperone partner of CDJ2. In blue native-PAGE of soluble cell extracts, CDJ2 and VIPP1 comigrated in complexes of >>669, approximately 150, and perhaps approximately 300 kDa. Our data suggest that CDJ2, presumably via coiled-coil interactions, binds to VIPP1 and presents it to HSP70B in the ATP state. Our findings and the previously reported requirement of VIPP1 for the biogenesis of thylakoid membranes point to a role for the HSP70B/CDJ2 chaperone pair in this process.