Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of Bifidobacterium longum subsp. suis.

Bifidobacteria are probiotic microorganisms commonly found in the gastrointestinal tract, some of which are known to utilize linear arabino-oligosaccharides (AOS) as prebiotic carbohydrates. In general, the synergistic actions of exo-type α-l-arabinofuranosidases (ABFs) and endo-α-1,5-l-arabinanases (ABNs) are required for efficient arabinan degradation. In this study, the putative gene cluster for arabinan degradation was discovered in the genome of Bifidobacterium longum subsp. suis. It consists of a variety of genes encoding exo- and endo-hydrolases, sugar-binding proteins, ABC-binding cassettes, and transcriptional regulators. Among them, two endo-ABNs GH43 (BflsABN43A and BflsABN43B), two exo-ABFs GH43 (BflsABF43A and BflsABF43B), and an exo-ABF GH51 (BflsABF51) were predicted to be the key hydrolases for arabinan degradation. These hydrolase genes were functionally expressed in Escherichia coli, and their enzymatic properties were characterized. Their synergism in arabinan degradation has been proposed from the detailed modes of action. Extracellular endo-BflsABN43A hydrolyzes sugar beet and debranched arabinans into the short-chain branched and linear AOS. Intracellularly, AOS can be further degraded into l-arabinose via the cooperative actions of endo-BflsABN43B, exo-BflsABF43A with debranching activity, α-1,5-linkage-specific exo-BflsABF43B, and exo-BflsABF51 with dual activities. The resulting l-arabinose is expected to be metabolized into energy through the pentose phosphate pathway by three enzymes expressed from the ara operon of bifidobacteria. It is anticipated that uncovering arabinan utilization gene clusters and their detailed functions in the genomes of diverse microorganisms will facilitate the development of customized synbiotics.

Characteristics and outcomes of patients with do-not-resuscitate and physician orders for life-sustaining treatment in a medical intensive care unit: a retrospective cohort study.

BACKGROUND: In the intensive care unit (ICU), we may encounter patients who have completed a Do-Not-Resuscitate (DNR) or a Physician Orders to Stop Life-Sustaining Treatment (POLST) document. However, the characteristics of ICU patients who choose DNR/POLST are not well understood. METHODS: We retrospectively analyzed the electronic medical records of 577 patients admitted to a medical ICU from October 2019 to November 2020, focusing on the characteristics of patients according to whether they completed DNR/POLST documents. Patients were categorized into DNR/POLST group and no DNR/POLST group according to whether they completed DNR/POLST documents, and logistic regression analysis was used to evaluate factors influencing DNR/POLST document completion. RESULTS: A total of 577 patients were admitted to the ICU. Of these, 211 patients (36.6%) had DNR or POLST records. DNR and/or POLST were completed prior to ICU admission in 48 (22.7%) patients. The DNR/POLST group was older (72.9 ± 13.5 vs. 67.6 ± 13.8 years, p < 0.001) and had higher Acute Physiology and Chronic Health Evaluation (APACHE) II score (26.1 ± 9.2 vs. 20.3 ± 7.7, p < 0.001) and clinical frailty scale (5.1 ± 1.4 vs. 4.4 ± 1.4, p < 0.001) than the other groups. Solid tumors, hematologic malignancies, and chronic lung disease were the most common comorbidities in the DNR/POLST groups. The DNR/POLST group had higher ICU and in-hospital mortality and more invasive treatments (arterial line, central line, renal replacement therapy, invasive mechanical ventilation) than the other groups. Body mass index, APAHCE II score, hematologic malignancy, DNR/POLST were factors associated with in-hospital mortality. CONCLUSIONS: Among ICU patients, 36.6% had DNR or POLST orders and received more invasive treatments. This is contrary to the common belief that DNR/POLST patients would receive less invasive treatment and underscores the need to better understand and include end-of-life care as an important ongoing aspect of patient care, along with communication with patients and families.

The Influence of Sex on Characteristics and Outcomes of Coronavirus-19 Patients: A Retrospective Cohort Study.

BACKGROUND: The influence of sex on the clinical characteristics and prognosis of coronavirus disease (COVID-19) patients is variable. This study aimed to evaluate COVID-19 management based on sex differences. METHODS: We retrospectively reviewed COVID-19 patients who were admitted to the tertiary hospital between January 2020 and March 2021. Logistic regression analysis was used to evaluate the factors associated with in-hospital mortality. RESULTS: During the study period, 584 patients were admitted to our hospital. Among them, 305 patients (52.2%) were female, and 279 patients (47.8%) were male. Males were younger than females, and frailty scale was lower in males than in females. Fever was more common in males, and there was no difference in other initial symptoms. Among the underlying comorbidities, chronic obstructive disease was more common in males, and there were no significant differences in other comorbidities. Moreover, treatment, severity, and outcome did not significantly differ between the groups. The risk factors for in-hospital mortality were age, high white blood cell count, and c-reactive protein level. CONCLUSIONS: We found no definite sex differences in the clinical characteristics and outcomes of COVID-19 patients. However, a better understanding of sex-dependent differences in COVID-19 patients could help in understanding and treating patients.