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Our study highlights a dual role for SAMHD1 in regulating hepatitis B virus cccDNA levels and reverse transcriptase–dependent particle genesis., Chronic hepatitis B is one of the world’s unconquered diseases with more than 240 million infected subjects at risk of developing liver disease and hepatocellular carcinoma. Hepatitis B virus reverse transcribes pre-genomic RNA to relaxed circular DNA (rcDNA) that comprises the infectious particle. To establish infection of a naïve target cell, the newly imported rcDNA is repaired by host enzymes to generate covalently closed circular DNA (cccDNA), which forms the transcriptional template for viral replication. SAMHD1 is a component of the innate immune system that regulates deoxyribonucleoside triphosphate levels required for host and viral DNA synthesis. Here, we show a positive role for SAMHD1 in regulating cccDNA formation, where KO of SAMHD1 significantly reduces cccDNA levels that was reversed by expressing wild-type but not a mutated SAMHD1 lacking the nuclear localization signal. The limited pool of cccDNA in infected Samhd1 KO cells is transcriptionally active, and we observed a 10-fold increase in newly synthesized rcDNA-containing particles, demonstrating a dual role for SAMHD1 to both facilitate cccDNA genesis and to restrict reverse transcriptase-dependent particle genesis.

Previous work has covered some displacement reactions, eliminations and olefine-rearrangements in the systems n-octane1, t-butylyclohexane2, and decalin3. In order to facilitate product-analyses in the last-named system, by the author and by future workers, two analytical problems were examined. The first problem was to devise a gas-liquid chromatographic method of separating the six alcohols (1-6) shown below. These alcohols are related to the possible substitution-products to be obtained form the solvolyses of trans-decalyl sulphonate esters. Out of a survey of three possible stationary phases, 1,1-oxydiglycerol was selected as the successful one. The second problem was the seperation of the following olefines (7-12). Although only four of these olefines (7,8,9 and 11) are likely products from solvolyses of trans-decalyl compounds, the complete analysis of the octalins would be useful in the study of their equilibration. Previous work has involved the use of more than one partial analysis3b, 3c. In this instance a successful phase proved to be 1,2-bis(2'-cyanoethoxy)ethane. It was chosen from a survey of ten phases. An analytical method was devised whereby mixtures of decalyl acetates (after conversion to the corresponding alcohols via treatment with lithium aluminium hydride) or of octalins could be reliably analysed as percentages of products formed during a reaction in solution in acetic acid. It was found that a number of precautions were needed if the former methid was to be reliable. Otherwise equilibration (presumably via an Oppenauer-Ponndorf mechanism) leads to the more stable (equatorial) epimer. The first application of the above methods was the analysis of products from the acetolysis of toluene-p-sulphonates of axial (5) and equatorial (6) trans-β-decalols. These compounds react more slowly than the corresponding compounds in the 4-t-butycyclohexyl system3g. The products from these latter reactions have recently been analysed2b. Comparison with these results indicated that the higher rate in the 4-t-butylcyclohexyl system is parelled by a higher olefine-yield in the equatorial case (but not in the axial one). A possible explanation of the slower rate of reaction of the decalyl compounds is that the hybridisation-change (sp3 to sp2) involved in these reactions of trans-decalin. Another factor contributing to the rate- and product- differences may be that non-chair forms are significant reacting conformations; possible non-chair forms are different for the two systems. A more detailed comparison of the products shows a much higher ratio of retention/inversion from the decalyl compounds. This is probably due to material rearranged to the other β-position. this ambiguity could be solved by repeating the work with resolved material. The effect of different cations (included as acetates to neutralise toluene-p-sulphonic acid formed during the reaction) on the reaction was found to be very small. The effects of the nature of leaving group and the temperature were small and in the same sense as was observed in other systems 1c, 2b. Streitwieser obtained kinetic evidence for sulphonate-exchange during the acetolysis of 2-actyl sulphonates4. Evidence was obtained that decalyl naphthalene-β-sulphonates are formed during the acetolyses of trans-β-decalyl tolune-p-sulphonates in the presence of potassium naphthalene-β-sulphonates. The extent was such that any effect on products would be negligibly small. Products were analysed from the acetolyses of the tolune-p-sulphonates of the trans-α-decalols (3 and 4). Kinetics3g and product-analysis from the axial epimer (3) suggest hydrogen-participation leading to the tertiary carbonium ion. the equatorial epimer is slow o react and the products contain material derived from a rearranged β-carbonium ion-pair, apparently similar to the one formed during the acetolysis of the tolune-p-sulphonate of the β-axial alcohol (5). A preliminary study of the reaction of trans-β-octalin (11) with solutions of toluene-p-sulphonic acid in acetic acid showed the reaction to be reduced in rate by tetrahydrofuran. An analysis of such acetylated material as was formed from this reduced reaction showed it to be largely axial. Nuclear magnetic resonance spectra of some decalyl compounds were recorded. Differences in chemical shifts for the proton marked (13) in pairs of epimers were in moderately good agreement with the value based on calculations of long-range shielding5.

The rise in the incidence rate of spontaneous intracranial hypotension (SIH) has increased the burden on physicians to accurately diagnose and treat patients presenting with SIH. However, conclusive evidence on the efficacy and risks associated with targeted epidural blood patches (EBPs) versus nontargeted ones does not exist. Herein, we describe two patients diagnosed with SIH who were treated with lumbar EBPs rather than with targeted EBPs at Vanderbilt University Medical Center. However, both patients were instructed to stay supine for 24 hours after the procedure. Both patients reported drastic improvement of symptoms within two days of the procedure. Furthermore, neither of the patients had any complications associated with the treatment. Based on this evidence, lumbar EBPs followed by rest in the supine position could be an effective and safe solution to SIH patients with CSF leaks in the cervical or thoracic regions of the spine. However, more detailed studies need to be performed for conclusive evidence on this topic.

Background Nilvadipine may lower rates of conversion from mild-cognitive impairment to Alzheimer's disease (AD), in hypertensive patients. However, it remains to be determined whether treatment with nilvadipine is safe in AD patients, given the higher incidence of orthostatic hypotension (OH) in this population, who may be more likely to suffer from symptoms associated with the further exaggeration of a drop in BP. Objective The aim of this study was to investigate the safety and tolerability of nilvadipine in AD patients. Methods AD patients in the intervention group (n = 56) received nilvadipine 8 mg daily over 6-weeks, compared to the control group (n = 30) who received no intervention. Differences in systolic (SBP) and diastolic (DBP) blood pressure, before and after intervention, was assessed using automated sphygmomanometer readings and ambulatory BP monitors (ABP), and change in OH using a finometer. Reporting of adverse events was monitored throughout the study. Results There was a significant reduction in the SBP of treated patients compared to non-treated patients but no significant change in DBP. Individuals with higher initial blood pressure (BP) had greater reduction in BP but individuals with normal BP did not experience much change in their BP. While OH was present in 84% of the patients, there was no further drop in BP recorded on active stand studies. There were no significant differences in adverse event reporting between groups. Conclusion Nilvadipine was well tolerated by patients with AD. This study supports further investigation of its efficacy as a potential treatment for AD. Copyright © 2010 John Wiley & Sons, Ltd.