Characterization of RNA interactions of dMi-2

Chromatin is maintained in a dynamic relaxed or repressed state such that DNA binding sites for the transcription machinery are either accessible or occluded. This way the gene expression is regulated. There are several chromatin regulators including ATP-dependent chromatin remodelers that help change or modulate the conformation of the chromatin to repress or to facilitate gene expression. Recent studies have implicated several chromatin remodelers in RNA binding. However, the precise function of this RNA binding property is intensively debated due to our limited understanding of its function. In this thesis, dMi-2, an ATP-dependent chromatin remodeler, has been studied for its interaction with RNA and a model is proposed for the effects of RNA binding on its function that supports the hypothesis that RNA binding modulates the function of chromatin remodelers. In the first part of this thesis, the RNA binding properties of dMi-2 were characterized in vitro. dMi-2 formed biochemically stable complexes with several RNAs of varying sequences. This suggested a binding of promiscuous nature. However, dMi-2 bound some RNAs with higher affinity compared with others. Further, the RNA binding regions in dMi-2 were mapped. The major RNA binding regions of dMi-2 were located in its N-terminal part. Analysis of the type of sequences that dMi-2 bound to revealed a preference for G-rich RNA. In the second part of this study, in vivo RNA binding of dMi-2 was characterized in an unbiased genome-wide manner. The individual nucleotide-resolution crosslinking and immunoprecipitation (iCLIP) experiment recapitulated the promiscuous nature of RNA binding that was found in in vitro assays. iCLIP revealed thousands of different dMi-2-binding RNAs. Further analysis revealed that dMi-2 interacted almost exclusively near the 3’-end of the mRNAs. At the cross-linking site, G-nucleotides were enriched. In the third part of this thesis, the effects of RNA binding on the function of dMi-2 were studied. It was shown that RNA binding inhibits the remodeling activity of dMi-2. Further analysis illustrated that the RNAs that bound dMi-2 with higher affinity also inhibited its remodeling better compared with the RNAs that bound with lower affinity. Biochemical analysis revealed that the depletion of RNA led to an increased chromatin occupancy of dMi- 2. Likewise, inhibition of transcription in vivo also resulted to an increased chromatin occupancy of dMi-2. In summary, the results of this thesis support a model which suggests that dMi-2-RNA interaction causes inhibition of the remodeling function of dMi-2. This may be caused by eviction of dMi-2 from chromatin upon RNA interaction. At actively transcribing genes, RNA competes dMi-2 away from the chromatin and at repressed genes, dMi-2 has increased chromatin occupancy due to lack of RNA. This thesis contributes to the understanding of the role of RNA interaction in modulating the function of chromatin remodelers

Proximally Based Medial Hemi-Soleus Muscle Flap Employed For Moderate-Sized Pretibial Defects of the Middle Third of the Leg

OBJECTIVES This study was undertaken to document the clinical indications and outcome of proximally based medial Hemi-soleus muscle flap for coverage of moderate-sized complex pretibial defects of the middle third of the leg. METHODOLOGY This descriptive case series was conducted at the Department of Plastic Surgery, National Institute of Rehabilitation Medicine (NIRM), Islamabad and Burn & Trauma Center, Hayatabad, Peshawar, over five years. (i.e., from November 01, 2016, to December 31, 2021). It included all adult patients of either gender whose complex pretibial wounds of the middle third leg were managed with proximally based medial Hemi-soleus muscle flaps. RESULTS The mean age was 31.40±9.83 years, ranging between 19-47 years. All the patients had complex post-traumatic defects secondary to road traffic accidents. There were 9(33.3%) patients with minor defects (i.e., measuring ≤2×2 cm2), whereas 18(66.6%) patients had medium-sized defects (i.e., ≥2×2 cm2 and ≤7×5 cm2). Their hospital stay ranged between 9-15 days with a mean stay of 11.92±3.1 days. All the flaps (100%) survived. Partial skin graft loss was encountered among three patients (n=3;11.1%). CONCLUSION The study provides a good evidence base regarding the usefulness of the flap in managing complex defects of the leg. It is recommended to carry out similar studies internationally. These should help improve our findings and come up with further refinements

Convalescent Plasma Therapy in Coronavirus Disease 2019 (COVID-19) Patients: A Brief Review

The recent outbreak of the COVID-19 pandemic has reevaluated effectiveness of the convalescent plasma therapy (CPT). This review was carried out to assess the usefulness of CPT in critically COVID-19 patients, based on the published data to date. To the best of our knowledge, this is the second review of the usefulness of CPT in COVID-19 patients. PubMed, Google Scholar, Medline and EMBASE databases were searched for the relevant reports up to June 21, 2020. All the records of the published data were analyzed according to eligibility criteria protocols. Five different studies on CPT for COVID-19 critically ill patients were included in this review. The significant findings from the records are: (a) the CPT may help to reduce mortality in the seriously ill patients (b) administration of CPT increased antibodies titer and reduced the level of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) RNA beyond detection limit (c) transfusion of convalescent plasma (CP) subsided clinical symptoms. Based on the currently available data, the CPT in the COVID-19 patients seems effective, safe and reduces mortality. There is urgent need of performing well-designed, multicenter clinical trials for establishing efficacy of the CPT in COVID-19 patients

Chemically cross-linked poly(acrylic-co-vinylsulfonic) acid hydrogel for the delivery of isosorbide mononitrate.

We report synthesis, characterization, and drug release attributes of a series of novel pH-sensitive poly(acrylic-co-vinylsulfonic) acid hydrogels. These hydrogels were prepared by employing free radical polymerization using ethylene glycol dimethacrylate (EGDMA) and benzyl peroxide (BPO) as cross-linker and initiator, respectively. Effect of acrylic acid (AA), polyvinylsulfonic acid (PVSA), and EGDMA on prepared hydrogels was investigated. All formulations showed higher swelling at high pHs and vice versa. Formulations containing higher content of AA and EGDMA show reduced swelling, but one with higher content of PVSA showed increased swelling. Hydrogel network was characterized by determining structural parameters and loaded with isosorbide mononitrate. FTIR confirmed absence of drug polymer interaction while DSC and TGA demonstrated molecular dispersion of drug in a thermally stable polymeric network. All the hydrogel formulations exhibited a pH dependent release of isosorbide mononitrate which was found to be directly proportional to pH of the medium and PVSA content and inversely proportional to the AA contents. Drug release data were fitted to various kinetics models. Results indicated that release of isosorbide mononitrate from poly(AA-co-VSA) hydrogels was non-Fickian and that the mechanism was diffusion-controlled

Discoloration in poplar tree and production of sprouts after harvest

Poplar is distributed widely throughout the world. There are about 30 natural species. Taxonomically poplars are divided into six groups. Poplar tree can be 200-300 years old. Normally two sets of 19 chromosomes are present in the nucleus of Poplar, while the size of genome is remarkably small. Poplar is a fast growing species. Poplar species are deciduous and semi evergreen and are distributed widely on the northern hemisphere. Poplars have various ecological habitats. They can grow in pure stands or mixed with other hardwood and conifer species. Poplars are also used in short rotation forestry for production of biomass for bio energy, fiber and environmental services. The short rotation forestry in Sweden is based on Salix but in this study the focus is on poplar. Discoloration occurs normally in the core wood for most poplar species. Present thesis is made in order to study the distribution of the discoloration for poplars. In the study 36 poplar trees from three provinces in Sweden (Lat. 56-60˚ N.) were measured. Discs were collected at different percentages of different stem height. The objective of work was to observe the relationship of discoloration with diameter and height of poplar tree. Besides these 36 sample trees, a clear felled poplar stand at Valsätra in Uppsala Municipality was studied. Diameter and discoloration on 110 stumps were measured. In the third part the measurements of shootings of poplar species in Valsätra are shown. The discoloration in stems was directly proportional with the height of the tree. The percentage of discoloration in a stem decreased with increasing tree height

Sustainability, market conditions and outreach: the vicious misconception of the win-win proposition in the microfinance industry

The shift of the Microfinance Institutions (MFIs) from the poverty- lending approach to the financial system approach is likely to have two counterbalancing effects on the social mission of poverty alleviation and women empowerment. On the one hand and as is desirable financial sustainability could cause MFIs to increase the depth and breadth of their outreach. But on the other hand and possibly at the cost of the social mission financial sustainability may become the core objective of the MFIs. The aim of this paper is to investigate which of the two outcomes is most likely in MFIs following the financial system approach. For this purpose, the paper first develops a theoretical framework to deduce testable hypotheses. The hypotheses are then tested with data from 158 rated MFIs, using various panel data estimation techniques. Results obtained thus reveal that majority of the MFIs in developing countries hold some market power. Besides, we find that financial sustainability is at odds with the social mission of alleviating poverty and empowering women and does not translate into depth and breadth of outreach. The study also discusses some policy implications of the result

COVID-19 and the Unseen Benefits of Dexamethasone

According to World Health Organization (WHO) current updates, the COVID-19 pandemic has spread all over the globe affecting 216 countries and caused 8,860,331 confirmed cases and 465,740 deaths last followed by 24 June 2020. Many countries cannot afford the nucleic acid tests to confirm COVID-19 infected patients; as a result, people cannot know the COVID-19 status of the people living around them. The use of dexamethasone in COVID-19 hospitalized patients for up to 10 days lower 28-day mortality as compared to the patients taking usual care and also receiving mechanical ventilation at randomization (by age-adjusted percentage points 12.3, approximately one third of proportional reduction) and those patients receiving oxygen without invasive mechanical ventilation (by age-adjusted percentage points 4.1, approximately one fifth of proportional reduction)