Interrelations of α- and ß-amylase activity with starch, sugars, and culinary and nutritional quality attributes in sweetpotato storage roots.

BACKGROUND: Little information is available on α- and ß-amylase activity and their associations with starch, sugars and other culinary qualities in sweetpotato. The present study aimed to assess sweetpotato storage root α- and ß-amylase activity in relation to starch, sugars, ß-carotene content and storage root flesh color. RESULTS: α- and ß-amylase activity (α-AA and ß-AA) were assayed from a Tanzania (T) × Beauregard (B) genetic mapping population in their uncured (raw), cured and stored (approximately 11 weeks) forms during 2016 and 2017. Ceralpha and Betamyl methods, with modifications to suit a high-throughput microplate assay format, were used to quantify α-AA and ß-AA, respectively. Storage root dry matter, starch, glucose, fructose, sucrose and ß-carotene content were predicted using near infrared reflectance spectroscopy. There was little relationship (r2 = 0.02-0.08, P ≤ 0.05 in 2016 and r2 = 0.05-0.11, P ≤ 0.05 in 2017) between α-AA and ß-AA. We observed negative linear associations between α-AA and dry matter content and generally no correlations between ß-AA and dry matter content. ß-AA and sugars were weakly positively correlated. ß-AA and ß-carotene content were positively correlated (r = 0.3-0.4 in 2016 and 0.3-0.5 in 2017). CONCLUSION: Generally, the correlation coefficient for amylase enzyme activity and sugar components of storage roots at harvest increased after curing and during post-harvest storage. The present study is a major step forward in sweetpotato breeding in terms of providing a better understanding of how α- and ß-amylase activity are inter-associated with several culinary quality attributes. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Development of NIRS calibration curves for sugars in baked sweetpotato.

BACKGROUND: Variability in sugar content between raw and cooked sweetpotato storage roots impact nutritional and dietary importance with implications for consumer preference. High-throughput phenotyping is required to breed varieties that satisfy consumer preferences. RESULTS: Near-infrared reflectance spectroscopy (NIRS) calibration curves were developed for analysing sugars in baked storage roots using 147 genotypes from a population segregating for sugar content and other traits. The NIRS prediction curves had high coefficients of determination in calibration (R2 c ) of 0.96 (glucose), 0.93 (fructose), 0.96 (sucrose), and 0.96 (maltose). The corresponding coefficients of determination for cross-validation (R2 cv ) were 0.92 (glucose), 0.89 (fructose), 0.96 (sucrose) and 0.93 (maltose) and were similar to the R2 c for all sugars measured. The ratios of the standard deviation of the reference set to the standard error of cross-validation were greater than three for all sugars. These results confirm the applicability of the NIRS curves in efficiently determining sugar content in baked sweetpotato storage roots. External validation was performed on an additional 70 genotypes. Coefficients of determination (r2 ) were 0.88 (glucose), 0.88 (fructose), 0.86 (sucrose) and 0.49 (maltose). The results were comparable to those found for the calibration and cross-validation in fructose, glucose, and sucrose, but were moderate for maltose due to the low variability of maltose content in the population. CONCLUSIONS: NIRS can be used for screening sugar content in baked sweetpotato storage roots in breeding programs and can be used to assist with the development of improved sweetpotato varieties that better meet consumer preferences. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Antimicrobial stewardship in a community hospital: attacking the more difficult problems.

BACKGROUND: Antibiotic stewardship has been proposed as an important way to reduce or prevent antibiotic resistance. In 2001, a community hospital implemented an antimicrobial management program. It was successful in reducing antimicrobial utilization and expenditure. In 2011, with the implementation of a data-mining tool, the program was expanded and its focus transitioned from control of antimicrobial use to guiding judicious antimicrobial prescribing. OBJECTIVE: To test the hypothesis that adding a data-mining tool to an existing antimicrobial stewardship program will further increase appropriate use of antimicrobials. DESIGN: Interventional study with historical comparison. METHODS: Rules and alerts were built into the data-mining tool to aid in identifying inappropriate antibiotic utilization. Decentralized pharmacists acted on alerts for intravenous (IV) to oral conversion, perioperative antibiotic duration, and restricted antimicrobials. An Infectious Diseases (ID) Pharmacist and ID Physician/Hospital Epidemiologist focused on all other identified alert types such as antibiotic de-escalation, bug-drug mismatch, and double coverage. Electronic chart notes and phone calls to physicians were utilized to make recommendations. RESULTS: During 2012, 2,003 antimicrobial interventions were made with a 90% acceptance rate. Targeted broad-spectrum antimicrobial use decreased by 15% in 2012 compared to 2010, which represented cost savings of $1,621,730. There were no statistically significant changes in antimicrobial resistance, and no adverse patient outcomes were noted. CONCLUSIONS: The addition of a data-mining tool to an antimicrobial stewardship program can further decrease inappropriate use of antimicrobials, provide a greater reduction in overall antimicrobial use, and provide increased cost savings without negatively affecting patient outcomes.

Therapeutic drug monitoring of prednisolone after lung transplantation.

BACKGROUND: Despite well-known and serious potential side-effects of corticosteroid therapy, therapeutic drug monitoring (TDM) of prednisolone is rarely performed after lung transplantation (LTx). METHODS: We measured prednisolone exposure using a 6-hour area-under-the-curve (AUC) analysis in 52 LTx recipients (41 bilateral, 9 single and 2 heart-lung), who were 99 +/- 13 (mean +/- SEM) weeks (range 4 to 380) post-LTx. Fourteen of 52 had cystic fibrosis (CF), and 36 of 52 were on cyclosporine and 16 of 52 on tacrolimus. Prednisolone dose was 9.8 +/- 0.7 mg/day (range 1 to 20). RESULTS: Only 9 of 52 LTx patients had a prednisolone AUC within the previously reported reference range for healthy adult control subjects (170 to 260 nmol x hr/liter/milligram prednisolone). Six patients had values below and 37 above this range. Prednisolone AUC was higher in patients with CF compared with non-CF patients (511 +/- 82 vs 349 +/- 27 nmol x hr/liter/milligram, p < 0.02) and 70% of LTx recipients had measurable prednisolone levels at baseline (26.5 +/- 4.5 nmol/liter), unlike normal controls. CONCLUSIONS: LTx recipients show a wide inter-individual variation in prednisolone pharmacokinetics; therefore, many are overdosed on conventional protocols. Side-effects of corticosteroid therapy remain a major clinical problem after transplantation, justifying the use of prednisolone TDM to optimize dosing and minimize morbidity.

Controlling use of antimicrobials in a community teaching hospital.

OBJECTIVE: To test the hypothesis that antibiotic use could be controlled or improved in a community teaching hospital, with improvement defined as reductions in overall use, overall cost, and antimicrobial resistance. DESIGN: Interventional study with historical comparison. SETTING: A not-for-profit, 900-bed community general hospital with residents in medicine, surgery, obstetrics-gynecology, and psychiatry. PARTICIPANTS: Physicians who requested any of the targeted antibiotics. INTERVENTIONS: Three categories of inpatient antibiotic orders were monitored beginning in April 2001: conversion from intravenous to oral administration for selected highly bioavailable antimicrobials, cessation of perioperative prophylaxis within 24 hours for patients undergoing clean and clean-contaminated surgery, and consultation with an infectious diseases physician before continuing administration of selected drugs beyond 48 hours. Data were analyzed after the first 33 months. Patient outcomes were reviewed during the hospital stay and at readmission if it occurred within 30 days after discharge. RESULTS: From April 2001 through December 2003, a total of 1426 requests for antimicrobial therapy met criteria for intervention. Overall physician compliance with the program was 76%, ranging from 57% for perioperative prophylaxis to 92% for intravenous to oral conversion. Antimicrobial costs per patient-day decreased by 31%, from 13.67 US dollars in 2000 (before program implementation) to 9.41 US dollars in 2003. Total savings in acquisition costs were 1,841,203 US dollars for the 3-year period. Resistance to numerous drugs among Klebsiella pneumoniae isolates was also significantly reduced. CONCLUSIONS: A program to improve the use of antibiotics in a community hospital was successful in reducing overall use, overall cost, and antimicrobial resistance.

CD161 (human NKR-P1A) signaling in NK cells involves the activation of acid sphingomyelinase.

NK and NKT cells play a major role in both innate immunity and in influencing the development of adaptive immune responses. CD161 (human NKR-P1A), a protein encoded in the NK gene complex, is a major phenotypic marker of both these cell types and is thought to be involved in the regulation of NK and NKT cell function. However, the mechanisms of action and signaling pathways of CD161 are poorly understood. To identify molecules able to interact with the cytoplasmic tail of human CD161 (NKR-P1A), we have conducted a yeast two-hybrid screen and identified acid sphingomyelinase as a novel intracellular signaling pathway linked to CD161. mAb-mediated cross-linking of CD161, in both transfectants and primary human NK cells, triggers the activation of acid, but not neutral sphingomyelinase. The sphingomyelinases represent the catabolic pathway for N-acyl-sphingosine (ceramide) generation, an emerging second messenger with key roles in the induction of apoptosis, proliferation, and differentiation. These data therefore define a novel signal transduction pathway for the CD161 (NKR-P1A) receptor and provide fresh insights into NK and NKT cell biology.