MIDDLE EAR AND NASOPHARYNGEAL BACTERIAL FLORA AND THEIR SENSITIVITY IN ACTIVE STAGE OF MUCOSAL DISEASE OTITIS MEDIA: A COMPARISON

Objective: Identifying the role of nasopharyngeal bacteria in recurrent middle ear (ME) infection helps in developing an effective treatment strategy.We aimed to compare bacterial flora of ME with nasopharynx (NP) and their sensitivity patterns in active stage of mucosal disease - otitis media(CSOM).Methods: Ear and nasopharyngeal swabs from patients with active ear discharge for >3 months were processed for culture and sensitivity, theorganisms were identified using Gram-stain.Results: Twenty patients between 10 and 65 years and male:female ratio of 13:7 were enrolled. 9 had symptoms since childhood. 10 patientscomplained unilateral ear discharge; five each had discharge from the left and right ear. 11 patients had nasal symptoms; nose block due to obstruction(9), nasal discharge (8), and both symptoms were seen in eight patients. 14 patients (70.0%) had deviated nasal septum and 8 (40.0%) had dischargein the NP. Of 20 ear swabs, 19 grew bacteria; 1 was sterile (5.0%). 13 (65%) nasopharyngeal swabs grew bacteria, 7 were sterile. Culture yieldedaerobic bacteria. Staphylococcus aureus was the most common bacterium (9/20, 45.0%) followed by Pseudomonas (7/20, 35.0%) isolated from theear. The most common nasopharyngeal isolate was S. aureus (9=45%). 10 patients had common ME and nasopharyngeal flora. Organisms weresensitive to amoxicillin+clavulanic acid, fluoroquinolones. Sensitivity was observed to polymyxin, trimethoprim, and sulfamethoxazole also.Conclusion: Common ME and nasopharyngeal flora with same antibiotic sensitivity pattern suggest nasopharyngeal etiology. Nasopharyngeal floramay have a role in recurrent ME infections in mucosal disease - otitis media.Keywords: Bacterial flora, Bacterial sensitivity, mucosal disease otitis media, Pseudomonas aeruginosa, Staphylococcus aureus

Aberrant activation of TCL1A promotes stem cell expansion in clonal haematopoiesis

Mutations in a diverse set of driver genes increase the fitness of haematopoietic stem cells (HSCs), leading to clonal haematopoiesis1. These lesions are precursors for blood cancers2,3,4,5,6, but the basis of their fitness advantage remains largely unknown, partly owing to a paucity of large cohorts in which the clonal expansion rate has been assessed by longitudinal sampling. Here, to circumvent this limitation, we developed a method to infer the expansion rate from data from a single time point. We applied this method to 5,071 people with clonal haematopoiesis. A genome-wide association study revealed that a common inherited polymorphism in the TCL1A promoter was associated with a slower expansion rate in clonal haematopoiesis overall, but the effect varied by driver gene. Those carrying this protective allele exhibited markedly reduced growth rates or prevalence of clones with driver mutations in TET2, ASXL1, SF3B1 and SRSF2, but this effect was not seen in clones with driver mutations in DNMT3A. TCL1A was not expressed in normal or DNMT3A-mutated HSCs, but the introduction of mutations in TET2 or ASXL1 led to the expression of TCL1A protein and the expansion of HSCs in vitro. The protective allele restricted TCL1A expression and expansion of mutant HSCs, as did experimental knockdown of TCL1A expression. Forced expression of TCL1A promoted the expansion of human HSCs in vitro and mouse HSCs in vivo. Our results indicate that the fitness advantage of several commonly mutated driver genes in clonal haematopoiesis may be mediated by TCL1A activation

Longitudinal profiling of clonal hematopoiesis provides insight into clonal dynamics

Background: Clonal hematopoiesis of indeterminate potential (CHIP), the age-related expansion of mutant hematopoietic stem cells, confers risk for multiple diseases of aging including hematologic cancer and cardiovascular disease. Whole-exome or genome sequencing can detect CHIP, but due to those assays’ high cost, most population studies have been cross-sectional, sequencing only a single timepoint per individual. Results: We developed and validated a cost-effective single molecule molecular inversion probe sequencing (smMIPS) assay for detecting CHIP, targeting the 11 most frequently mutated genes in CHIP along with 4 recurrent mutational hotspots. We sequenced 548 multi-timepoint samples collected from 182 participants in the Women’s Health Initiative cohort, across a median span of 16 years. We detected 178 driver mutations reaching variant allele frequency ≥ 2% in at least one timepoint, many of which were detectable well below this threshold at earlier timepoints. The majority of clonal mutations (52.1%) expanded over time (with a median doubling period of 7.43 years), with the others remaining static or decreasing in size in the absence of any cytotoxic therapy. Conclusions: Targeted smMIPS sequencing can sensitively measure clonal dynamics in CHIP. Mutations that reached the conventional threshold for CHIP (2% frequency) tended to continue growing, indicating that after CHIP is acquired, it is generally not lost. The ability to cost-effectively profile CHIP longitudinally will enable future studies to investigate why some CHIP clones expand, and how their dynamics relate to health outcomes at a biobank scale

Spt6 is a maintenance factor for centromeric CENP-A

Replication and transcription of genomic DNA requires partial disassembly of nucleosomes to allow progression of polymerases. This presents both an opportunity to remodel the underlying chromatin and a danger of losing epigenetic information. Centromeric transcription is required for stable incorporation of the centromere-specific histone dCENP-A in M/G1 phase, which depends on the eviction of previously deposited H3/H3.3-placeholder nucleosomes. Here we demonstrate that the histone chaperone and transcription elongation factor Spt6 spatially and temporarily coincides with centromeric transcription and prevents the loss of old CENP-A nucleosomes in both Drosophila and human cells. Spt6 binds directly to dCENP-A and dCENP-A mutants carrying phosphomimetic residues alleviate this association. Retention of phosphomimetic dCENP-A mutants is reduced relative to wildtype, while non-phosphorylatable dCENP-A retention is increased and accumulates at the centromere. We conclude that Spt6 acts as a conserved CENP-A maintenance factor that ensures long-term stability of epigenetic centromere identity during transcription-mediated chromatin remodeling

Polo kinase recruitment via the constitutive centromere-associated network at the kinetochore elevates centromeric RNA

The kinetochore, a multi-protein complex assembled on centromeres, is essential to segregate chromosomes during cell division. Deficiencies in kinetochore function can lead to chromosomal instability and aneuploidy-a hallmark of cancer cells. Kinetochore function is controlled by recruitment of regulatory proteins, many of which have been documented, however their function often remains uncharacterized and many are yet to be identified. To identify candidates of kinetochore regulation we used a proteome-wide protein association strategy in budding yeast and detected many proteins that are involved in post-translational modifications such as kinases, phosphatases and histone modifiers. We focused on the Polo-like kinase, Cdc5, and interrogated which cellular components were sensitive to constitutive Cdc5 localization. The kinetochore is particularly sensitive to constitutive Cdc5 kinase activity. Targeting Cdc5 to different kinetochore subcomplexes produced diverse phenotypes, consistent with multiple distinct functions at the kinetochore. We show that targeting Cdc5 to the inner kinetochore, the constitutive centromere-associated network (CCAN), increases the levels of centromeric RNA via an SPT4 dependent mechanism

Impact of Thermal Cycling on Carbon Fiber Reinforced Glass Epoxy Laminates

Wind Turbine blade icing is a serious problem in cold climates, which leads to production losses, failure of the blade, ice throw etc. To eliminate production downtime associated with icing of wind turbine blades, a structurally integrated, carbon fiber based wind turbine blade heating system has been proposed. The de-icing of the blades, where the carbon fiber element is heated which results in a temperature gradient across the blade which may compromise the structural properties of the material. This is explained by the uneven thermal expansion of the different components in the composite (blade) material. Due to the micro-cracking in the composite material it leads to deterioration of the material which further leads to failure. There is a need to investigate the effects of thermal cycling on the structural properties of the composite material. The two main parts of this thesis include the thermal cycling of the CF reinforced glass epoxy laminate samples and Flexural testing on the thermal cycled samples. Thermal cycling is performed on CF reinforced glass epoxy laminate samples with a range of -18 °C to 4 °C with a hold time of 10 minutes for each heating/cooling cycle. A set of 6 samples were taken for each thermal cycle and ran 0, 50, 100, 200 thermal cycles. Temperatures of the samples were recorded using the computer program as well as pictures were taken using a thermal camera; from this data it shows that there is a considerable temperature difference between the carbon fiber and side thermocouples. To study the effects of this temperature gradient on the flexural properties of the laminate, on all the samples three point bending tests (following ASTM standards) are performed and examined for any change in the properties with the increase in the number of thermal cycles. Test results showed that there is very little decrease in the ultimate stress when numbers of thermal cycles were increased from 0 to 200; this decrease is not significant to affect or degrade the material properties of the sample. There might be an effect on material properties when thermal cycling is done in higher levels with more thermal cycling temperature range.Mechanical Engineering, Department o

Curcumin Attenuates Staurosporine-Mediated Death of Retinal Ganglion Cells

The functional effect of curcumin, a free radical scavenger and an herbal medicine from Indian yellow curry spice, Curcuma longa, on protease-mediated retinal ganglion cell death was investigated. These results show, for the first time, that curcumin indeed prevents the protease-mediated death of RGCs, both in vitro and in vivo

Implementation of a Modular Distributed Fault-Tolerant Controller for MMC Applications

Centralized control algorithm limits the hardware flexibility of a modular multilevel converter (MMC). Therefore, distributed control structure has recently started to be seen in the industry application. Even though distributed controller reduces a single point of failure risk compared to the centralized controller, the failure risk of the entire control systems increases due to the number of local controllers. However, the distributed controller can be programmed in such a way as to replace the faulty local controller and sustain the MMC operation. In this paper, the distributed modular fault-tolerant controller is implemented in a laboratory-scale MMC prototype. The controller is built to control four SMs per phase for the proof-of-concept. Therefore, the MMC prototype is also built by two SMs per arm. The controller capability is validated with experimental and the Opal-RT result-time simulator results in a control-hardware-in-loop (CHIL) environment

Simultaneous quantitation of lamivudine, zidovudine and nevirapine in human plasma by liquid chromatography–tandem mass spectrometry and application to a pharmacokinetic study

A rapid and sensitive LC–MS/MS method for the simultaneous quantitation of lamivudine, zidovudine and nevirapine in human plasma using abacavir as internal standard has been developed and validated. The analytes and IS were extracted from plasma by solid phase extraction using Oasis HLB cartridges and separated on a Hypurity Advance C18 column using a mixture of acetonitrile:0.1% formic acid (76:24, v/v) at a flow rate of 0.8 mL/min. Detection involved an API-4000 LC–MS/MS with electrospray ionization in the positive ion mode and multiple-reaction monitoring for analysis. The method was validated according to FDA guidelines and shown to provide intra- and inter-day precision and accuracy within acceptable limits in a run time of only 3.5 min. The method was successfully applied to a pharmacokinetic study involving a single oral administration of a combination tablet to human male volunteers