The optimization of engineered metabolic pathways requires careful control over the levels and timing of metabolic enzyme expression1-4. Optogenetic tools are ideal for achieving such precise control, as light can be applied and removed instantly without complex media changes. Here we show that light-controlled transcription can be used to enhance the biosynthesis of valuable products in engineered Saccharomyces cerevisiae. We introduce new optogenetic circuits to shift cells from a light-induced growth phase to a darkness-induced production phase, which allows us to control fermentation purely with light. Furthermore, optogenetic control of engineered pathways enables a new mode of bioreactor operation using periodic light pulses to tune enzyme expression during the production phase of fermentation to increase yields. Using these advances, we control the mitochondrial isobutanol pathway to produce up to 8.49 ± 0.31 g/L of isobutanol and 2.38 ± 0.06 g/L of 2-methyl-1-butanol micro-aerobically from glucose. These results make a compelling case for the application of optogenetics to metabolic engineering for valuable products.

Immunization with live influenza virus expands Th1 memory cells and facilitates more rapid recovery after heterosubtypic virus challenge. Immunization with inactivated virus generates a Th2 response and does not lead to heterosubtypic immunity. Creation of a Th1 priming environment by the inclusion of interleukin (IL)-12 with antibodies to IL-4 converted the response against inactivated virus to a Th1 response that was able to facilitate virus clearance upon heterosubtypic virus challenge. Evaluation of memory responses of mice immunized by the various protocols demonstrated that the type of immunization imprints T cell memory, dictating the nature of the response to subsequent infection. After live virus challenge, expansion of Th1 cells seems to facilitate the generation of cytotoxic T lymphocytes from naïve precursors. This latter finding may be the mechanism by which inactivated virus immunization in a Th1 cytokine context mediates heterosubtypic immunity.

These data indicate that Abetax-42 and Abetax-43 are important species associated with early disease progression and suggest that the physiochemical properties of the Abeta species may be a major determinant in amyloid deposition. The results support an important role for Abeta in mediating initial pathogenic events in Alzheimer disease dementia and reinforce that treatment strategies targeting the formation, accumulation, or cytotoxic effects of Abeta should be pursued.

there was no association between overall cognitive decline and NVAF after 3 years' follow-up, nor any apparent effect of anti-thrombotic therapy. This is consistent with our baseline results, but conflicts with previous studies. Cognitive decline is probably multifactorial and any influence of NVAF was not identified in this study.

BACKGROUND: Birth cohort screening is recommended for hepatitis C virus (HCV) and underserved populations are disproportionally affected by HCV. Little is known about the influence of race on the HCV care continuum in this population. OBJECTIVE: To assess the cascade of HCV care in a large racially diverse and underserved birth cohort. DESIGN: Retrospective cohort study using electronic medical record data abstracted until August 31, 2017. PATIENTS: 34,810 patients born between 1945 and 1965 engaged in primary care between October 1, 2014, and October 31, 2016, within the safety-net clinics of the San Francisco Health Network. MAIN MEASURES: Rate of hepatitis C testing, hepatitis C treatment, and response to therapy. RESULTS: Cohort characteristics were as follows: median age 59 years, 57.6% male, 25.5% White (20.6% Black, 17.7% Latino, 33.0% Asian/Pacific Islander (API), 2% other), and 32.6% preferred a non-English language. 99.7% had an HCV test (95.4% HCV antibody, 4.3% HCVRNA alone). Among HCV antibody-positive patients (N = 4587), 22.9% were not tested for confirmatory HCVRNA. Among viremic patients (N = 3673), 20.8% initiated HCV therapy, 90.6% achieved sustained virologic response (SVR) and 8.1% did not have a SVR test. HCV screening and treatment were highest in APIs (98.7 and 34.7% respectively; p < 0.001). Blacks had the highest chronic HCV rate (22.2%; p < 0.001). Latinos had the lowest SVR rate (81.3%; p = 0.01). On multivariable analysis, API race (vs White, OR 1.20; p = 0.001), presence of HIV co-infection (OR 1.58; p = 0.02), presence of chronic kidney disease (OR 0.47; p < 0.001), English (vs non-English) as preferred language (OR 0.54; p = 0.002), ALT (OR 0.39 per doubling; p < 0.001), and HCVRNA (OR 0.83 per 10-fold increase; p < 0.001) were associated with HCV treatment. CONCLUSIONS: Despite near-universal screening, gaps in active HCV confirmation, treatment, and verification of cure were identified and influenced by race. Tailored interventions to engage and treat diverse and underserved populations with HCV infection are needed.

Objective:Atrial Fibrillation (AF) is associated with dementia. If AF-related cognitive decline is driven by cerebral embolic events, thromboprophylaxis may impact on this.This systematic review assessed the association between cognitive impairment and AF thromboprophylaxis. Conclusions:Our analyses show no definitive evidence of cognitive benefit or harm from anticoagulation. We demonstrated a potential benefit of anticoagulation in comparison to antiplatelet over time. Larger-scale studies with longer follow-up are needed to determine the true cognitive impact of AF thromboprophylaxis. 3 Key points• Atrial fibrillation (AF) is associated with dementia, the mechanism of which is not fully understood.• Published data do not prove any decrease (or increase) in incident dementia over time in patients anticoagulated versus those treated with antiplatelet or placebo.• The clinical significance of improvements in cognition comparing those treated with anticoagulation and antiplatelet is uncertain.• Data are not definitive and future AF studies and registries should collect cognitive outcomes.

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Background: Hematologic toxicity is a critical problem limiting treatment delivery in cancer patients undergoing concurrent chemoradiotherapy. However, the extent to which anatomic variations in radiation dose limit chemotherapy delivery is poorly understood. A unique natural experiment arises in patients with head and neck and cervical cancer, who frequently undergo identical chemotherapy but receive radiation to different regions of the body. Comparing these cohorts can help elucidate to what extent hematologic toxicity is attributable to marrow radiation as opposed to chemotherapy. Methods: In this longitudinal cohort study, we compared hematologic toxicity and bone marrow compensatory response in 148 patients (90 cervix, 58 head/neck) undergoing chemoradiotherapy with concurrent weekly cisplatin 40 mg/m 2 . We used linear mixed effect models to compare baseline and time-varying peripheral cell counts and hemoglobin levels between cohorts. To assess bone marrow compensatory response, we measured the change in metabolically active bone marrow (ABM) volume on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography. Results: We observed greater reductions in log-transformed lymphocyte, platelet, and absolute neutrophil counts (ANC) for cervix compared to head/neck cancer patients (fixed effects for time-cohort interaction [95% CI]: lymphocytes, −0.06 [−0.09, −0.031]; platelets,−0.028 [-0.051, −0.0047]; ANC, −0.043 [−0.075, −0.011]). Mean ANC nadirs were also lower for cervical vs. head/neck cancer cohorts (2.20 vs. 2.85 × 10 3 per μL, p < 0.01). Both cohorts exhibited reductions in ABM volume within the radiation field, and increases in ABM volume in out-of-field areas, indicating varying compensatory response to radiation injury. Conclusions: Cervical cancer patients had faster decreases in ANC, lymphocyte, and platelet counts, and lower ANC nadirs, indicating a significant effect of pelvic irradiation on acute peripheral blood cell counts. Both cohorts exhibited a compensatory response with increased out-of-field bone marrow activity.