Modeling Pichia pastoris Growth on Methanol and Optimizing the Production of a Recombinant Protein, the Heavy-Chain Fragment C of Botulinum Neurotoxin, Serotype A

An unstructured growth model for the recombinant methylotrophic yeast P. pastoris Mut+ expressing the heavy-chain fragment C of botulinum neurotoxin serotype A [BoNT/A(Hc)], was successfully established in quasi-steady state fed-batch fermentations with varying cell densities. The model describes the relationships between specific growth rate and methanol concentration, and the relationships between specific methanol and ammonium consump-tion rates and specific growth rate under methanol-limited growth conditions. The maximum specific growth rate (μ) determined from the model was 0.08 h−1 at a methanol concentration of 3.65 g/L, while the actual maximum μ was 0.0709 h−1. The maximum specific methanol consumption rate was 0.0682 g/g WCW/h. From the model, growth can be defined as either methanol-limited or metha-nol-inhibited and is delineated at a methanol concentration of 3.65 g/L. Under inhibited conditions, the observed biomass yield (YX/MeOH) was lower and the maintenance coefficient (mMeOH) was higher than compared to limited methanol conditions. The YX/MeOH decreased and mMeOH increased with increasing methanol concen-tration under methanolinhibited conditions. BoNT/A(Hc) content in cells (a) under inhibited growth was lower than that under limited growth, and decreased with increasing methanol concentration. A maximum a of 1.72 mg/g WCW was achieved at a μ of 0.0267 h−1 and induction time of 12 h

Crystallization and preliminary X-ray analysis of \u3ci\u3eNa\u3c/i\u3e-ASP-1, a multi-domain pathogenesis-related-1 protein from the human hookworm parasite \u3ci\u3eNecator americanus\u3c/i\u3e

Human hookworm infection is a major cause of anemia and malnutrition in the developing world. In an effort to control hookworm infection, the Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective larval stage (L3) of the parasite, including a family of pathogenesis-related-1 (PR-1) proteins known as the ancylostoma-secreted proteins (ASPs). The functions of the ASPs are unknown. In addition, it is unclear why some ASPs have one while others have multiple PR-1 domains. There are no known structures of a multi-domain ASP and in an effort to remedy this situation, recombinant Na-ASP-1 has been expressed, purified and crystallized. Na-ASP-1 is a 406-amino-acid multi-domain ASP from the prevalent human hookworm parasite Necator americanus. Useful X-ray data to 2.2 A ° have been collected from a crystal that belongs to the monoclinic space group P21 with unit-cell parameters a = 67.7, b = 74.27, c = 84.60 Å, β = 112.12°. An initial molecular-replacement solution has been obtained with one monomer in the asymmetric unit

Crystallization and preliminary X-ray analysis of \u3ci\u3eNa\u3c/i\u3e-ASP-1, a multi-domain pathogenesis-related-1 protein from the human hookworm parasite \u3ci\u3eNecator americanus\u3c/i\u3e

Human hookworm infection is a major cause of anemia and malnutrition in the developing world. In an effort to control hookworm infection, the Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective larval stage (L3) of the parasite, including a family of pathogenesis-related-1 (PR-1) proteins known as the ancylostoma-secreted proteins (ASPs). The functions of the ASPs are unknown. In addition, it is unclear why some ASPs have one while others have multiple PR-1 domains. There are no known structures of a multi-domain ASP and in an effort to remedy this situation, recombinant Na-ASP-1 has been expressed, purified and crystallized. Na-ASP-1 is a 406-amino-acid multi-domain ASP from the prevalent human hookworm parasite Necator americanus. Useful X-ray data to 2.2 A ° have been collected from a crystal that belongs to the monoclinic space group P21 with unit-cell parameters a = 67.7, b = 74.27, c = 84.60 Å, β = 112.12°. An initial molecular-replacement solution has been obtained with one monomer in the asymmetric unit

Crystallization and preliminary X-ray analysis of Na-ASP-1, a multi-domain pathogenesis-related-1 protein from the human hookworm parasite Necator americanus. Corrigendum

A correction to the paper by Asojo et al. [(2005), Acta Cryst. F61, 391–394]

Determining the incidence and risk factors for short-term complications following distal biceps tendon repair

Background Distal biceps rupture is a relatively uncommon injury that can significantly affect quality of life. Early complications following biceps tendon repair are not well described in the literature. This study utilizes a national surgical database to determine the incidence of and predictors for short-term complications following distal biceps tendon repair. Methods The American College of Surgeons’ National Surgical Quality Improvement Program database was used to identify patients undergoing distal biceps repair between January 1, 2011, and December 31, 2017. Patient demographic variables of sex, age, body mass index, American Society of Anesthesiologists class, functional status, and several comorbidities were collected for each patient, along with 30-day postoperative complications. Binary logistic regression was used to calculate risk ratios for these complications using patient predictor variables. Results Early postoperative surgical complications (0.5%)—which were mostly infections (0.4%)—and medical complications (0.3%) were rare. A readmission risk factor was diabetes (risk ratio [RR], 4.238; 95% confidence interval [CI], 1.180–15.218). Non-home discharge risk factors were smoking (RR, 3.006; 95% CI, 1.123–8.044) and ≥60 years of age (RR, 4.150; 95% CI, 1.611– 10.686). Maleness was protective for medical complications (RR, 0.024; 95% CI, 0.005–0.126). Surgical complication risk factors were obese class II (RR, 4.120; 95% CI, 1.123–15.120), chronic obstructive pulmonary disease (COPD; RR, 21.981; 95% CI, 3.719–129.924), and inpatient surgery (RR, 8.606; 95% CI, 2.266–32.689). Conclusions Complication rates after distal biceps repair are low. Various patient demographics, medical comorbidities, and surgical factors were all predictive of short-term complications

Crystallization and preliminary X-ray analysis of Na-ASP-1, a multi-domain pathogenesis-related-1 protein from the human hookworm parasite Necator americanus

In order to clarify the structural basis of the pathogenesis-related-1 domain, Na-ASP-1, the first multi-domain ASP from the human hookworm parasite N. americanus, has been crystallized. 2.2 Å resolution data have been collected from a crystal belonging to the monoclinic space group P21

Predictive Analysis of Healthcare Resource Utilization after Elective Spine Surgery

Introduction: The management of degenerative spine pathology continues to be a significant source of costs to the US healthcare system. Besides surgery, utilization of healthcare resources after spine surgery drives costs. The responsibility of managing costs is gradually shifting to patients and providers. Patient-centered predictors of healthcare utilization after elective spine surgery may identify targets for cost reduction and value creation. Therefore, our study aims to quantify patterns of healthcare utilization and identify risk factors that predict high healthcare utilization after elective spine surgery. Methods: A total of 623 patients who underwent elective spine surgery at a tertiary academic medical center by one of three fellowship-trained orthopedic spine surgeons between 2013 and 2018 were identified in this retrospective cohort study. Healthcare utilization was quantified including advanced spine imaging, emergency and urgent care visits, hospital readmission, reoperation, PT/OT referrals, opioid prescriptions, epidural steroid injections, and pain management referrals. Patient variables, namely, the Charlson comorbidity index (CCI) and the American Society of Anesthesiologists (ASA) classification system, were assessed as potential predictors for healthcare utilization. Results: Among all patients, a wide range of health utilization was identified. Age, body mass index, Charlson Comorbidity Index, and American Society of Anesthesiology class were identified as positive predictors of postoperative healthcare utilization including emergency department visits, spine imaging studies, opioid and nerve blocker prescriptions, inpatient rehabilitation, any referrals, and pain management referrals. Conclusions: Markers of patient health―such as CCI and ASA class―may be used to predict healthcare utilization following elective spine surgery. Identifying at-risk patients and addressing these challenges prior to surgery is an important step to deliver efficient postoperative care. Level of Evidence:

Coronal Heating as Determined by the Solar Flare Frequency Distribution Obtained by Aggregating Case Studies

Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counter-intuitively heats coronae to temperatures that are orders of magnitude hotter than the corresponding photospheres. It is widely accepted that the magnetic field is responsible for the heating, but there are two competing mechanisms that could explain it: nanoflares or Alfv\'en waves. To date, neither can be directly observed. Nanoflares are, by definition, extremely small, but their aggregate energy release could represent a substantial heating mechanism, presuming they are sufficiently abundant. One way to test this presumption is via the flare frequency distribution, which describes how often flares of various energies occur. If the slope of the power law fitting the flare frequency distribution is above a critical threshold, $\alpha=2$ as established in prior literature, then there should be a sufficient abundance of nanoflares to explain coronal heating. We performed $>$600 case studies of solar flares, made possible by an unprecedented number of data analysts via three semesters of an undergraduate physics laboratory course. This allowed us to include two crucial, but nontrivial, analysis methods: pre-flare baseline subtraction and computation of the flare energy, which requires determining flare start and stop times. We aggregated the results of these analyses into a statistical study to determine that $\alpha = 1.63 \pm 0.03$. This is below the critical threshold, suggesting that Alfv\'en waves are an important driver of coronal heating.Comment: 1,002 authors, 14 pages, 4 figures, 3 tables, published by The Astrophysical Journal on 2023-05-09, volume 948, page 7