Venezuelan equine encephalitis virus E1 protein interacts with PDIA6 and PDI inhibition reduces alphavirus production

Venezuelan equine encephalitis virus (VEEV) is an alphavirus transmitted by mosquitos that can cause a febrile illness and induce severe neurological complications in humans and equine populations. Currently there are no FDA approved vaccines or antiviral treatments to combat VEEV. Proteomic techniques were utilized to create an interactome of the E1 fusion glycoprotein of VEEV. VEEV E1 interacted with a number of cellular chaperone proteins including protein disulfide isomerase family A member 6 (PDIA6). PDI inhibition through LOC14 and/or nitazoxanide treatment effectively decreased production of VEEV and other alphaviruses in vitro, including eastern equine encephalitis virus, Sindbis virus, and chikungunya virus. Decreased oxidoreductive capabilities of PDIs through LOC14 or nitazoxanide treatment impacted both early and late events in viral replication, including the production of non-infectious virions and decreased VEEV E1 disulfide bond formation. Results from this study identified PDIs as critical regulators of alphavirus replication and potential therapeutic targets.

Combination Kinase Inhibitor Treatment Suppresses Rift Valley Fever Virus Replication

Viruses must parasitize host cell translational machinery in order to make proteins for viral progeny. In this study, we sought to use this signal transduction conduit against them by inhibiting multiple kinases that influence translation. Previous work indicated that several kinases involved in translation, including p70 S6K, p90RSK, ERK, and p38 MAPK, are phosphorylated following Rift Valley fever virus (RVFV) infection. Furthermore, inhibiting p70 S6K through treatment with the FDA approved drug rapamycin prevents RVFV pathogenesis in a mouse model of infection. We hypothesized that inhibiting either p70 S6K, p90RSK, or p90RSK’s upstream kinases, ERK and p38 MAPK, would decrease translation and subsequent viral replication. Treatment with the p70 S6K inhibitor PF-4708671 resulted in decreased phosphorylation of translational proteins and reduced RVFV titers. In contrast, treatment with the p90RSK inhibitor BI-D1870, p38MAPK inhibitor SB203580, or the ERK inhibitor PD0325901 alone had minimal influence on RVFV titers. The combination of PF-4708671 and BI-D1870 treatment resulted in robust inhibition of RVFV replication. Likewise, a synergistic inhibition of RVFV replication was observed with p38MAPK inhibitor SB203580 or the ERK inhibitor PD0325901 combined with rapamycin treatment. These findings serve as a proof of concept regarding combination kinase inhibitor treatment for RVFV infection.

Rapamycin modulation of p70 S6 kinase signaling inhibits Rift Valley fever virus pathogenesis

Despite over 60 years of research on antiviral drugs, very few are FDA approved to treat acute viral infections. Rift Valley fever virus (RVFV), an arthropod borne virus that causes hemorrhagic fever in severe cases, currently lacks effective treatments. Existing as obligate intracellular parasites, viruses have evolved to manipulate host cell signaling pathways to meet their replication needs. Specifically, translation modulation is often necessary for viruses to establish infection in their host. Here we demonstrated phosphorylation of p70 S6 kinase, S6 ribosomal protein, and eIF4G following RVFV infection in vitro through western blot analysis and in a mouse model of infection through reverse phase protein microarrays (RPPA). Inhibition of p70 S6 kinase through rapamycin treatment reduced viral titers in vitro and increased survival and mitigated clinical disease in RVFV challenged mice. Additionally, the phosphorylation of p70 S6 kinase was decreased following rapamycin treatment in vivo. Collectively these data demonstrate modulating p70 S6 kinase can be an effective antiviral strategy.

History and physical examination of elderly patients with dementia

The role of the physician is critical in the evaluation of cognitively impaired patients for two reasons: (a) The longitudinal relationship between the patient and physician provides a unique opportunity to observe changes over time, generating confidence that may encourage the patient and family to report any concerns; (b) All research in this field is geared toward the earliest possible intervention, a process made possible by early diagnosis. Preparations for interview and the interview process itself require special knowledge of dementia on the part of the evaluating physician, who must understand the potentials and problems of both the content the process of taking a history from the demented patient and his/her caregivers.

Relationship of isokinetic peak torque with work and power for ankle plantar flexion and dorsiflexion

Past research has analyzed the relationship of peak torque with work and power on the muscles surrounding the knee with correlation coefficients being reported, ranging from .67 to .99. No studies to date have examined this relationship for muscles surrounding the ankle joint. The purpose of this study was to analyze the relationship of peak torque with work and power for the plantar flexor and dorsiflexor muscles of the ankle. Isokinetic data were collected from 15 healthy subjects (six males, nine females; mean age = 26.6 years) on an isokinetic dynamometer across two trials at speeds of 30 and 120 degrees/sec. The results of Pearson product moment correlations between peak torque to work and peak torque to power indicated correlation coefficients ranging from .81 to .97 for all speeds of testing and angular velocities. These findings suggest that peak torque is representative of work and power.

Effect of ammonia on calcium homeostasis in primary astrocyte cultures

Calcium influx, accumulation and efflux were studied in primary cultures of rat astrocytes treated with ammonium chloride. Treatment of the cells for 3 days with 10 mMN4Cl resulted in a 35% reduction in 45Ca influx. The decrease in calcium influx was dose-dependent between 2 and 10 mM NH4Cl. Short-term (30 min) exposure to ammonia had no effect on calcium influx. Calcium accumulation, as measured by 20-min exposure to 45Ca, decreased after treating cultures with 10 mM NH4Cl for one or 3 days; a greater effect was observed after the 3-day treatment. Studies with lanthanum, an inhibitor of calcium transport, indicated that the effect of ammonia was not due to non-specific leakage of calcium. Calcium efflux was not affected by exposure of the cultures to ammonium chloride. Purinergic-evoked calcium influx and mobilization was not altered by ammonia. While the mechanism(s) of calcium homeostasis affected by long-term hyperammonemia remain to be defined, these results suggest that reduced astrocytic calcium may be related to the pathogenesis of ammonia-related disorders such as hepatic encephalopathy.

Nonmedical complications of diagnostic workup for dementia [clinic conference]

Testing for patients presenting with dementias can lead to diagnosis of disorders that can contribute to cognitive dysfunction, and to improvement, stabilization, or slowed deterioration in some demented patients. However, possible benefits must be balanced against possible costs. The present recommendations for workup of patients with dementia includes some tests with only marginal benefits, and a more limited workup may be as effective. This case demonstrates how important it is to be sensitive as well to possible effects on family relationships of demented patients. When we evaluate and treat demented patients, the dependence of the demented patient on the caregiver and the emotional and physical stresses experienced by many caregivers make it important to consider the patient and caregiver as a system vulnerable to many potential risks.