High Throughput Genetics And Characterization Of An RNA Arbovirus, Sindbis Virus, Using Accurate Next-Generation Sequencing Of Viral Evolution And RNA Enrichment

The goal of these studies was to investigate Sindbis virus adaptation to various infection bottlenecks and utilize the dynamics of minor variants to study viral genetics in a high-throughput manner. During infection an RNA virus exists as a tremendously diverse population, and this genetic diversity underlies their ability to rapidly adapt to new conditions and cause disease. Since viruses evolve as populations, our understanding of viral evolution has historically been limited by the inability to characterize populations. Whilst new sequencing technologies provide sufficient depth to sequence full viral populations, their intrinsic base-calling error rate combined with mutations introduced during sample processing makes viral mutations and sequencing errors indistinguishable. Utilizing rolling reverse transcription, the novel CirSeq technique virtually eliminates sequencing errors by bioinformatically parsing tandem generated repeats, and for the first time allows a highly accurate mutational landscape profile of the whole viral population. In addition, a novel hybridization capture technique we developed allows us to maximize the sequencing coverage of desired viral RNA molecules. We used these technologies to map the mutational distribution of RNA virus populations and perform genetics are previously unseen scales. We sequenced serial passages of the well-characterized Sindbis virus to yield novel information on genetic features crucial for viral replication. We analyzed how the starting in vitro transcribed RNA population adapts to various bottlenecks encountered during electroporation and subsequent passaging, and during packaging and egress. Then we compared these data to previous studies of critical genome sites and expanded our study to new sites of interest. We posit that such unbiased high-throughput genetics pushes the envelope beyond the previous limits on discovery of viral functional elements. These techniques can be used to further characterize clinically relevant RNA viruses that are agents of current and recent epidemics, such as SARS-CoV-2 coronavirus, chikungunya virus, Zika virus, eastern equine encephalitis virus, dengue virus, and West Nile viru

Gait and cognition in older adults: Insights from the Bronx and Kerala

Background: Recent reports indicate that gait dysfunction can occur early in the course of cognitive decline suggesting that motor and cognitive functions in older adults may share common underlying brain substrates, pathological processes, and risk factors. Objective: This study was designed to report the association between gait and cognition in older adults in USA and the southern Indian state of Kerala. Materials and Methods: Literature review of gait and cognition studies conducted in Bronx County, USA as well as preliminary results from the Kerala-Einstein study (Kozhikode city, Kerala). Results: Review of published studies based in the Bronx shows that both clinical and quantitative gait dysfunction are common in older adults with cognitive impairment. Furthermore, clinical and quantitative gait dysfunction in cognitively normal older adults was a strong predictor of future cognitive decline and dementia. Our preliminary study in Kozhikode city shows that timed gait is slower in older adults diagnosed with dementia and mild cognitive impairment syndrome compared to healthy older controls. Conclusions: A strong association between gait and cognition is seen in seniors in USA as well as Kerala. A better understanding of the relationship between gait and cognition may help improve current diagnostic and therapeutic approaches globally

Oral lesions associated with nevirapine-related Stevens Johnson syndrome: A report of four cases

Nevirapine is a non-nucleoside reverse transcriptase inhibitor, widely used in combination with other antiretroviral agents for treatment of HIV infection. Steven Johnson syndrome (SJS) is the major toxicity of nevirapine. We describe here four cases of SJS in HIV seropositive patients following nevirapine therapy. In all four cases cutaneous hypersensitivity reaction was seen with extreme oral lesions, three patients presented clinically with elevated liver enzymes and hepatitis, and two patients had ocular involvement