Biochemical and Biophysical Characterization of the dsDNA Packaging Motor from the Lactococcus lactis Bacteriophage Asccphi28

Double-stranded DNA viruses package their genomes into pre-assembled protein procapsids. This process is driven by macromolecular motors that transiently assemble at a unique vertex of the procapsid and utilize homomeric ring ATPases to couple genome encapsidation to ATP hydrolysis. Here, we describe the biochemical and biophysical characterization of the packaging ATPase from Lactococcus lactis phage asccφ28. Size-exclusion chromatography (SEC), analytical ultracentrifugation (AUC), small angle X-ray scattering (SAXS), and negative stain transmission electron microscopy (TEM) indicate that the ~45 kDa protein formed a 443 kDa cylindrical assembly with a maximum dimension of ~155 Å and radius of gyration of ~54 Å. Together with the dimensions of the crystallographic asymmetric unit from preliminary X-ray diffraction experiments, these results indicate that gp11 forms a decameric D5-symmetric complex consisting of two pentameric rings related by 2-fold symmetry. Additional kinetic analysis shows that recombinantly expressed gp11 has ATPase activity comparable to that of functional ATPase rings assembled on procapsids in other genome packaging systems. Hence, gp11 forms rings in solution that likely reflect the fully assembled ATPases in active virus-bound motor complexes. Whereas ATPase functionality in other double-stranded DNA (dsDNA) phage packaging systems requires assembly on viral capsids, the ability to form functional rings in solution imparts gp11 with significant advantages for high-resolution structural studies and rigorous biophysical/biochemical analysis.     

Targeting Antigens for Universal Influenza Vaccine Development

Traditional influenza vaccines generate strain-specific antibodies which cannot provide protection against divergent influenza virus strains. Further, due to frequent antigenic shifts and drift of influenza viruses, annual reformulation and revaccination are required in order to match circulating strains. Thus, the development of a universal influenza vaccine (UIV) is critical for long-term protection against all seasonal influenza virus strains, as well as to provide protection against a potential pandemic virus. One of the most important strategies in the development of UIVs is the selection of optimal targeting antigens to generate broadly cross-reactive neutralizing antibodies or cross-reactive T cell responses against divergent influenza virus strains. However, each type of target antigen for UIVs has advantages and limitations for the generation of sufficient immune responses against divergent influenza viruses. Herein, we review current strategies and perspectives regarding the use of antigens, including hemagglutinin, neuraminidase, matrix proteins, and internal proteins, for universal influenza vaccine development.     

Herpesvirus Regulation of Selective Autophagy

Selective autophagy has emerged as a key mechanism of quality and quantity control responsible for the autophagic degradation of specific subcellular organelles and materials. In addition, a specific type of selective autophagy (xenophagy) is also activated as a line of defense against invading intracellular pathogens, such as viruses. However, viruses have evolved strategies to counteract the host’s antiviral defense and even to activate some proviral types of selective autophagy, such as mitophagy, for their successful infection and replication. This review discusses the current knowledge on the regulation of selective autophagy by human herpesviruses.     

Development of a clinical risk score for incident diabetes: A 10-year prospective cohort study

Aims/IntroductionWe developed a self‐assessable Korean Diabetes Risk score using the data of the Korean Genome and Epidemiology Study.Materials and MethodsA total of 8,740 participants without diabetes at baseline were followed up biannually over a period of 10 years. We included variables that were significantly different between participants who developed diabetes mellitus and those who did not in the development cohort at baseline. We assigned a maximum score of 100 to the selected variable in each gender group. Next, the 10‐year probability of incident diabetes was calculated and validated in the validation cohort. Finally, we compared the predictive power of Korean Diabetes Risk score with models including fasting plasma glucose or glycated hemoglobin and other cohort models of Atherosclerosis Risk in Communities and Korea National Health and Nutrition Examination Survey.ResultsDuring a median follow‐up period of 9.7 years, 22.7% of the participants progressed to diabetes. The Korean Diabetes Risk score included age, living location (urban or rural area), waist circumference, hypertension, family history of diabetes and smoking history. The developed risk score yielded acceptable discrimination for incident diabetes (area under the curve 0.657) and the predictive power was improved when the model included fasting plasma glucose (area under the curve 0.690) or glycated hemoglobin (area under the curve 0.746). In addition, our model predicted incident diabetes more accurately than previous Western or Korean models.ConclusionsThis newly developed self‐assessable diabetes risk score is easily applicable to predict the future risk of diabetes even without the necessity for laboratory tests. This score is useful for the Korean diabetes prevention program, because high‐risk individuals can be easily screened.     

Direct comparison of rapid deployment versus sutureless aortic valve replacement: a meta-analysis

BackgroundThis meta-analysis was conducted to compare the procedural and early outcomes of aortic valve replacement (AVR) using rapid deployment valve (RD group) versus sutureless valve (SU group).MethodsA literature search of 5 online databases was conducted. The primary outcomes were mean transvalvular pressure gradient (MPG) after AVR, the incidence of paravalvular leak (PVL) and the need for a permanent pacemaker implantation (PPI). The secondary outcomes included aortic cross-clamp (ACC) and cardiopulmonary bypass (CPB) times, early mortality and other postoperative complications, such as atrial fibrillation, bleeding reoperation and stroke.ResultsEight articles were included, and all outcomes except MPG after AVR in matched valve sizes were extracted from 7 studies (RD group =842 patients and SU group =1,386 patients). The pooled analysis demonstrated a lower MPG in the RD group than in the SU group, with mean difference (MD) of 2.64 mmHg. The pooled risk ratios of any PVL and grade ≥2 (or moderate) PVL were not significantly different between the groups; however, the incidence of PPI was significantly lower in the RD group than in the SU group, with a risk ratio of 0.69. The pooled analyses showed that the ACC and CPB times were significantly longer in the RD group than in the SU group, with weighted MDs of 8.74 (P<0.001) and 9.94 (P<0.001) minutes, respectively. The risks of early mortality and other postoperative complications were not significantly different between the groups.ConclusionsAVR using RD valve was associated with better valve hemodynamics in terms of the MPG than AVR using SU valve, and better outcomes were observed in the RD group regarding PPI. Procedural times were longer in AVR using RD valve than SU valve. Early clinical outcomes showed no difference between RD and SU valve.     

Surgery is a safe,effective first-line treatment modality for noninvasive prolactinomas

Pituitary - Dopamine agonists (DAs) have long been the recommended first-line treatment for prolactinoma. Given the remarkable developments in surgical techniques, however, surgery is on the rise....     

Early combination versus initial metformin monotherapy in the management of newly diagnosed type 2 diabetes: An East Asian perspective

Type 2 diabetes (T2D) in the East Asian population is characterized by phenotypes such as low body mass index, an index of β-cell dysfunction, and higher percentage of body fat, an index of insulin resistance. These phenotypes/pathologies may predispose people to early onset of diabetes with increased risk of stroke and renal disease. Less than 50% of patients with T2D in East Asia achieve glycaemic targets recommended by national or regional guidelines, which may be attributable to knowledge and/or implementation gaps. Herein, we review the latest evidence with special reference to East Asian patients with T2D and present arguments for the need to use early combination therapy to intensify glycaemic control. This strategy is supported by the 5-year worldwide VERIFY study, which reported better glycaemic durability in newly diagnosed patients with T2D with a mean HbA1c of 6.9% treated with early combination therapy of vildagliptin plus metformin versus those treated with initial metformin monotherapy followed by addition of vildagliptin only with worsening glycaemic control. This paradigm shift of early intensified treatment is now recommended by the American Diabetes Association and the European Association for the Study of Diabetes. In order to translate these evidence to practice, increased awareness and strengthening of the healthcare system are needed to diagnose and manage patients with T2D early for combination therapy.