Comprehensive analysis of long COVID in a Japanese nationwide prospective cohort study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly since 2019, and the number of reports regarding long COVID has increased. Although the distribution of long COVID depends on patient characteristics, epidemiological data on Japanese patients are limited. Hence, this study aimed to investigate the distribution of long COVID in Japanese patients. This study is the first nationwide Japanese prospective cohort study on long COVID. METHODS: This multicenter, prospective cohort study enrolled hospitalized COVID-19 patients aged ≥18 years at 26 Japanese medical institutions. In total, 1200 patients were enrolled. Clinical information and patient-reported outcomes were collected from medical records, paper questionnaires, and smartphone applications. RESULTS: We collected data from 1066 cases with both medical records and patient-reported outcomes. The proportion of patients with at least one symptom decreased chronologically from 93.9% (947/1009) during hospitalization to 46.3% (433/935), 40.5% (350/865), and 33.0% (239/724) at 3, 6, and 12 months, respectively. Patients with at least one long COVID symptom showed lower quality of life and scored higher on assessments for depression, anxiety, and fear of COVID-19. Female sex, middle age (41-64 years), oxygen requirement, and critical condition during hospitalization were risk factors for long COVID. CONCLUSIONS: This study elucidated the symptom distribution and risks of long COVID in the Japanese population. This study provides reference data for future studies of long COVID in Japan.

Remdesivir Treatment Lacks the Effect on Mortality Reduction in Hospitalized Adult COVID-19 Patients Who Required High-Flow Supplemental Oxygen or Invasive Mechanical Ventilation.

Background and Objectives: The therapeutic impact of remdesivir on hospitalized adult COVID-19 patients is unknown. The purpose of this meta-analysis was to compare the mortality outcomes of hospitalized adult COVID-19 patients receiving remdesivir therapy to those of patients receiving a placebo based on their oxygen requirements. Materials and Methods: The clinical status of the patients was assessed at the start of treatment using an ordinal scale. Studies comparing the mortality rate of hospitalized adults with COVID-19 treated with remdesivir vs. those treated with a placebo were included. Results: Nine studies were included and showed that the risk of mortality was reduced by 17% in patients treated with remdesivir. Hospitalized adult COVID-19 patients who did not require supplemental oxygen or who required low-flow oxygen and were treated with remdesivir had a lower mortality risk. In contrast, hospitalized adult patients who required high-flow supplemental oxygen or invasive mechanical ventilation did not have a therapeutic benefit in terms of mortality. Conclusions: The clinical benefit of mortality reduction in hospitalized adult COVID-19 patients treated with remdesivir was associated with no need for supplemental oxygen or requiring supplemental low-flow oxygen at the start of treatment, especially in those requiring supplemental low-flow oxygen.

Factors associated with oxygen requirement and persistent symptoms 1 year after severe COVID-19 infection.

OBJECTIVE: We aimed to describe the prevalence and factors associated with the need for supplemental oxygen and persistent symptoms 1 year after severe SARS-CoV-2 infection. METHODS: In this historical cohort and nested case-control study, we included adults with severe COVID-19 (requiring admission to the intensive care unit or invasive mechanical ventilation). We evaluated factors associated with a need for supplemental oxygen and persistent symptoms 1 year after severe infection. RESULTS: We included 135 patients (median age 62 years, 30% women). At 1-year follow-up, the main symptoms were dyspnea (32%), myalgia (9%), cough (7%), anxiety (4%), and depression (5%); 12.59% of patients had prolonged requirement for supplemental oxygen. Factors associated with a persistent requirement for supplemental oxygen were female sex (odds ratio 3.15, 95% confidence interval 1.11-8.90) and Charlson Comorbidity Index > 4 (odds ratio 1.60, 95% confidence interval 1.20-2.12). CONCLUSIONS: We found that a high prevalence of supplemental oxygen requirement 1 year after severe COVID infection was associated with female sex and a baseline high rate of comorbidities. It is unknown whether this prevalence was related to other factors, such as the altitude at which patients lived. More than half of patients had prolonged post-COVID syndrome.

Prevalence of antimicrobial-resistant Cutibacterium isolates and development of multiplex PCR method for Cutibacterium species identification.

INTRODUCTION: Cutibacterium species such as C. acnes, C. avidum, and C. granulosum are known anaerobic skin inhabitants and often cause surgical site infections. These species are genetically similar and are difficult to identify rapidly. In addition, their pathogenicity and antimicrobial resistance remain unknown. In this study, antimicrobial resistance in Cutibacterium isolates was studied and a multiplex PCR method for their identification was developed. METHODS: A total of 497 C. acnes, 71 C. avidum, and 25 C. granulosum strains which were isolated from the acne pustule and infectious regions, were used. RESULTS: The antimicrobial resistance rates of C. acnes, C. avidum, and C. granulosum strains isolated from patients with acne vulgaris were higher than those of strains isolated from patients with infectious diseases. In particular, macrolide-clindamycin-resistant strains were isolated most frequently from all species. Among the resistant strains, strains with 23S rRNA mutations were the most common in C. acnes (24.3%, 71/292), whereas C. avidum and C. granulosum strains were most frequently found with erm(X). For the first time, a C. granulosum strain carrying pTZC1, which codes erm(50) and tet(W), was isolated from patients with acne vulgaris. Regarding the rapid identification of causative pathogens from infectious regions, three Cutibacterium species were identified with 100% sensitivity and specificity using multiplex PCR method. CONCLUSIONS: Our data showed that antimicrobial resistance differed among Cutibacterium species. The multiplex PCR method may contribute to the rapid detection of Cutibacterium species and selection of appropriate antimicrobial agents.

Perioperative fluid management and associated complications in children receiving kidney transplants in the UK.

BACKGROUND: Intravenous fluid administration is an essential part of perioperative care for children receiving a kidney transplant. There is a paucity of evidence to guide optimal perioperative fluid management. This study aimed to identify the volume of perioperative fluids administered across 5 UK paediatric kidney transplant centres and explore associations between fluid volume administered, graft function, and fluid-related adverse events. METHODS: Data were collected from five UK paediatric kidney transplant centres on perioperative fluid volumes administered, and incidence of pulmonary oedema, systemic hypertension, and requirement for intensive care support. Children < 18 years of age who received a kidney-only transplant between 1st January 2020 and 31st December 2021 were included. RESULTS: Complete data from 102 children were analysed. The median total volume of fluid administered in 72 h was 377 ml/kg (IQR 149 ml/kg) with a high degree of variability. A negative relationship between total fluid volume administered and day 7 eGFR was noted (p < 0.001). Association between urine volume post-transplant and day 7 eGFR was also negative (p < 0.001). Adverse events were frequent but no significant difference was found in the fluid volume administered to those who developed an adverse event, vs those who did not. CONCLUSIONS: This study describes a high degree of variability in perioperative fluid volumes administered to children receiving kidney transplants. Both fluid volume and urine output were negatively associated with short-term graft function. These data contrast traditional interpretation of high urine output as a marker of graft health, and highlight the need for prospective clinical trials to optimise perioperative fluid administration for this group. A higher resolution version of the Graphical abstract is available as Supplementary information.

Six-minute walk test and its predictability in outcome of COVID-19 patients.

BACKGROUND: The world is worsely hit by the COVID-19 pandemic resulting in increased morbidity and mortality. Increased mortality has been observed in older adults with multiple comorbidities. Six-minute walk distance (6MWD) at admission can help us to guide the requirement of oxygen during hospital stay that can be used to determine which patient can be managed at home. MATERIALS AND METHODS: This study was a prospective observational study conducted on COVID-19 patients admitted at AIIMS, New Delhi, from October to December 2020. Patients aged more than 60 years were included in the study and underwent 6-min walk tests. Polypharmacy and multimorbidity were also assessed along with dyspnea which was measured on BORG scale. P < 0.05 was considered statistically significant. Statistical software STATA (version 14.2) was used for all the analyses. RESULTS: The mean age of the study population was 68.76 (7.4). Oxygen saturation prior to the 6-MWT was normal and has significantly higher than the post test (P ≤ 0.001). 6MWD was significantly correlated with pre values of oxygen saturation. 6MWD was observed more in patients who did not require oxygen during hospital stay. Self-reported dyspnea, pulse rate, oxygen saturation, and systolic blood pressure were significantly associated with the patients who had an oxygen requirement during the hospital stay. CONCLUSION: Self-reported dyspnea after 6MWT was found to be associated with oxygen requirement during hospital stay. Patients who have covered more distance in 6-min walk test have less oxygen requirement during hospital stay hence can be managed at home. This will reduce the health-care burden and will help to tackle the outburst during the ongoing pandemic.

Identification of Oxygen-Independent Pathways for Pyridine Nucleotide and Coenzyme A Synthesis in Anaerobic Fungi by Expression of Candidate Genes in Yeast.

Neocallimastigomycetes are unique examples of strictly anaerobic eukaryotes. This study investigates how these anaerobic fungi bypass reactions involved in synthesis of pyridine nucleotide cofactors and coenzyme A that, in canonical fungal pathways, require molecular oxygen. Analysis of Neocallimastigomycetes proteomes identified a candidate l-aspartate-decarboxylase (AdcA) and l-aspartate oxidase (NadB) and quinolinate synthase (NadA), constituting putative oxygen-independent bypasses for coenzyme A synthesis and pyridine nucleotide cofactor synthesis. The corresponding gene sequences indicated acquisition by ancient horizontal gene transfer (HGT) events involving bacterial donors. To test whether these enzymes suffice to bypass corresponding oxygen-requiring reactions, they were introduced into fms1Δ and bna2Δ Saccharomyces cerevisiae strains. Expression of nadA and nadB from Piromyces finnis and adcA from Neocallimastix californiae conferred cofactor prototrophy under aerobic and anaerobic conditions. This study simulates how HGT can drive eukaryotic adaptation to anaerobiosis and provides a basis for elimination of auxotrophic requirements in anaerobic industrial applications of yeasts and fungi. IMPORTANCE NAD (NAD+) and coenzyme A (CoA) are central metabolic cofactors whose canonical biosynthesis pathways in fungi require oxygen. Anaerobic gut fungi of the Neocallimastigomycota phylum are unique eukaryotic organisms that adapted to anoxic environments. Analysis of Neocallimastigomycota genomes revealed that these fungi might have developed oxygen-independent biosynthetic pathways for NAD+ and CoA biosynthesis, likely acquired through horizontal gene transfer (HGT) from prokaryotic donors. We confirmed functionality of these putative pathways under anaerobic conditions by heterologous expression in the yeast Saccharomyces cerevisiae. This approach, combined with sequence comparison, offers experimental insight on whether HGT events were required and/or sufficient for acquiring new traits. Moreover, our results demonstrate an engineering strategy for enabling S. cerevisiae to grow anaerobically in the absence of the precursor molecules pantothenate and nicotinate, thereby contributing to alleviate oxygen requirements and to move closer to prototrophic anaerobic growth of this industrially relevant yeast.

The value of AI based CT severity scoring system in triage of patients with Covid-19 pneumonia as regards oxygen requirement and place of admission.

CONTEXT: CT scan is a quick and effective method to triage patients in the Covid-19 pandemic to prevent the heathcare facilities from getting overwhelmed. AIMS: To find whether an initial HRCT chest can help triage patient by determining their oxygen requirement, place of treatment, laboratory parameters and risk of mortality and to compare 3 CT scoring systems (0-20, 0-25 and percentage of involved lung models) to find if one is a better predictor of prognosis than the other. SETTINGS AND DESIGN: This was a prospective observational study conducted at a Tertiary care hospital in Mumbai, Patients undergoing CT scan were included by complete enumeration method. METHODS AND MATERIAL: Data collected included demographics, days from swab positivity to CT scan, comorbidities, place of treatment, laboratory parameters, oxygen requirement and mortality. We divided the patients into mild, moderate and severe based on 3 criteria - 20 point CT score (OS1), 25 point CT score (OS2) and opacity percentage (OP). CT scans were analysed using CT pneumonia analysis prototype software (Siemens Healthcare version 2.5.2, Erlangen, Germany). STATISTICAL ANALYSIS: ROC curve and Youden's index were used to determine cut off points. Multinomial logistic regression used to study the relations with oxygen requirement and place of admission. Hosmer-Lemeshow test was done to test the goodness of fit of our models. RESULTS: A total of 740 patients were included in our study. All the 3 scoring systems showed a significant positive correlation with oxygen requirement, place of admission and death. Based on ROC analysis a score of 4 for OS1, 9 for OS2 and 12.7% for OP was determined as the cut off for oxygen requirement. CONCLUSIONS: CT severity scoring using an automated deep learning software programme is a boon for determining oxygen requirement and triage. As the score increases, the chances of requirement of higher oxygen and intubation increase. All the three scoring systems are predictive of oxygen requirement.

Obesity, glucose intolerance, advanced age, and lymphocytopenia are independent risk factors for oxygen requirement in Japanese patients with Coronavirus disease 2019 (COVID-19).

At the current time of rising demand for hospital beds, it is important to triage COVID-19 patients according to the treatment needed during hospitalization. The need for oxygen therapy is an important factor determining hospital admission of these patients. Our retrospective study was designed to identify risk factors associated with the progression to oxygen requirement in COVID-19 patients. A total of 133 patients with laboratory-confirmed COVID-19 were admitted to our hospital from February 22, 2020, to August 23. After excluding asymptomatic, non-Japanese, pediatric, pregnant patients and also those who needed oxygen immediately at admission, data of the remaining 84 patients were analyzed. The patients were separated into those who required oxygen after admission and those who did not, and their characteristics were compared. Age, body mass index (BMI), lymphocyte count, C-reactive protein (CRP), lactate dehydrogenase, estimated glomerular filtration rate, glucose intolerance, hypertension, and dyslipidemia were significantly different between the two groups. Multivariate analysis identified four significant and independent risk factors of oxygen requirement, including advanced age, obesity, glucose intolerance and lymphocytopenia. Dividing the patients into subgroups according to the number of these risk factors found in each patient indicated that the need for oxygen increased with higher number of these risk factors in the same individual. Our results suggest that the presence of higher number of these risk factors in COVID-19 patients is associated with future oxygen requirement and that this index can be potentially useful in triaging COVID-19 patients staying home in the context of need for hospitalization.

Outcomes in Patients With COVID-19 Disease and High Oxygen Requirements.

BACKGROUND: Approximately 19% of people infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) progress to severe or critical stages of the coronavirus disease 2019 (COVID-19) with a mortality rate exceeding 50%. We aimed to examine the characteristics, mortality rates, intubation rate, and length of stay (LOS) of patients hospitalized with COVID-19 disease with high oxygen requirements (critically ill). METHODS: We conducted a retrospective analysis in a single center in Brooklyn, New York. Adult hospitalized patients with confirmed COVID-19 disease and high oxygen requirements were included. We performed multivariate logistic regression analyses for statistically significant variables to reduce any confounding. RESULTS: A total of 398 patients were identified between March 19th and April 25th, 2020 who met the inclusion criteria, of which 247 (62.1%) required intubation. The overall mortality rate in our study was 57.3% (n = 228). The mean hospital LOS was 19.1 ± 17.4 days. Patients who survived to hospital discharge had a longer mean LOS compared to those who died during hospitalization (25.4 ± 22.03 days versus10.7 ± 1.74 days). In the multivariate analysis, increased age, intubation and increased lactate dehydrogenase (LDH) were each independently associated with increased odds of mortality. Diarrhea was associated with decreased mortality (OR 0.4; CI 0.16, 0.99). Obesity and use of vasopressors were each independently associated with increased intubation. CONCLUSIONS: In patients with COVID-19 disease and high oxygen requirements, advanced age, intubation, and higher LDH levels were associated with increased mortality, while diarrhea was associated with decreased mortality. Gender, diabetes, and hypertension did not have any association with mortality or length of hospital stay.

Prolonged Oxygen Therapy Post COVID-19 Infection: Factors Leading to the Risk of Poor Outcome.

BACKGROUND: Coronavirus disease 2019 (COVID-19) infection is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a single-stranded ribonucleic acid (RNA) ß-coronavirus. Prolonged duration of symptoms, ill health, disability, and need for hospitalisation are all well-known features of severe COVID-19 disease. OBJECTIVE: To describe the epidemiological, clinical and imaging characteristics of hospitalised patients of COVID-19 who required prolonged oxygen therapy after testing negative for SARS-CoV-2 and attempt to determine the associated factors leading to delayed recovery, failure to wean, and mortality. MATERIAL AND METHOD: Prospective observational study from 9th September to 6th November 2020 in a tertiary care COVID hospital of Jharkhand. Included COVID-19-infected patients requiring oxygen to maintain a saturation of ≥95% after testing reverse transcription polymerase chain reaction (RT-PCR) negative. Patients were classified as Group I, those who could be weaned off oxygen, and Group II, those who could not be weaned off oxygen during their stay in the isolation ward. A detailed assessment for outcome in these two groups related to age, gender, presence or absence of co-morbidities, nature of co-morbidities and findings of high-resolution CT (HRCT) thorax was done to ascertain risk factors for failure to wean and adverse outcomes. RESULTS: During the study period, 93 patients suffering from moderate to severe COVID-19 infection, could not be discharged from the hospital and were admitted to the post-COVID isolation ward after testing RT-PCR negative, due to breathlessness and need for oxygen therapy, with a male predominance, M:F ratio of 2.2:1. Of these 93 patients, 51 could be weaned off oxygen in the isolation ward. The mean and median age of patients who could be successfully weaned was 58.5±14.3 years and 60 years respectively, compared to a mean age of 64±12.4 years and a median age of 67 years for patients who could not be weaned off oxygen during the isolation period. Patients aged ≥60 years were at risk for prolonged requirement of oxygen compared to those <50 years of age, relative risk (RR) 1.43 (95%CI 0.9-2, p=0.051). Failure to wean in <50 years was noted in presence of co-morbidities, RR 4 (95%CI 1.5-10.6, p=0.005). Multivariable logistic regression analysis calculated an odds ratio (OR) of 12.22 (95%CI 2.4-61.5, p<0.002) in patients of coronary artery disease (CAD), and 3.34 (95%CI 1.01-10.9, p<0.046) in patients of diabetes, for failure to wean with delayed recovery in patients aged 50 years and more, having multiple co-morbidities. Presence of ≥three co-morbid conditions was associated with increased risk of critical care unit (CCU) admissions (RR 2.1, p=0.02), failure to wean (RR 1.79, p<0.006), and death (p=0.02). Elderly male patients (mean age of 81.3±7.2years) with CAD and multiple comorbidities were at a high risk of mortality (p=0.01). CONCLUSION:  Patients ≥50 years of age having ≥three co-morbidities are at increased risk of prolonged hospitalisation and oxygen therapy in moderate to severe COVID-19 infection, precluding their discharge even after they test negative for SARS-CoV-2. Elderly male patients of COVID-19 with CAD and multiple comorbidities are at a high risk of mortality.

Cardiac Arrhythmias and COVID-19: Correlation With Disease Severity.

Background Cardiac arrhythmia is one of the life-threatening cardiovascular complications commonly reported in patients hospitalized with coronavirus disease 2019 (COVID-19). We aimed to evaluate the association between cardiac arrhythmias and disease severity based on oxygen requirement. Methods In this retrospective observational chart review-based study we recruited 396 patients hospitalized with COVID-19 from March 2020 to May 2020 from two regional medical centers in New Jersey, USA. Patients' baseline characteristics, secondary diagnoses, and laboratory findings were manually extracted and compared among two groups: patients with cardiac arrhythmias and those without. Poisson regression analysis was used to evaluate the correlation of cardiac arrhythmias and increased oxygen requirement, which are: room air (RA), nasal cannula (NC), high flow nasal cannula (HFNC), and bi-level positive airway pressure ventilation or invasive mechanical ventilation (BIPAP/MV). Results The demographic characteristics of the patients were: aged 61 +/- 18.7 years (mean +/- standard deviation); with 56% being male, and 44.9% of African American race. There were 16% patients on RA, 40% on NC, 15% on HFNC, and 29% on BIPAP/MV. The incidence of cardiac arrhythmias was 36.7% (20% pulseless electrical activity (PEA), 13.5% atrial fibrillation (AF). 56% of AF was new-onset arrhythmia. Compared to the RA group, the risk of cardiac arrhythmias was significantly higher in BIPAP/MV (OR 3.3; 95% CI 1.8 - 6.2, p <0.001) and HFNC (OR 2.9; 95% CI 1.5-5.7, p0.001), but not in NC group (OR 0.95; 95% CI 0.4-1.8, p0.89). Compared to patients without arrhythmias, patients with arrhythmias were older (mean age 71 vs. 56 years, p <0.001) and had more comorbidities (Charlson comorbidity index (CCI), 4.7 vs. 2.9, p <0.001). The continued therapy of angiotensin-converting enzyme inhibitors or angiotensin-II receptor blockers did not seem to be associated with increased or decreased risk of cardiac arrhythmias. Conclusion The incidence of cardiac arrhythmias among hospitalized COVID-19 patients was 36.7% with PEA being common in patients who succumbed to death, and AF in those patients who survived. The incidence of cardiac arrhythmias positively correlated with disease severity based on oxygen requirement and was higher among patients requiring HFNC or BIPAP/MV.

Exploiting the Diversity of Saccharomycotina Yeasts To Engineer Biotin-Independent Growth of Saccharomyces cerevisiae.

Biotin, an important cofactor for carboxylases, is essential for all kingdoms of life. Since native biotin synthesis does not always suffice for fast growth and product formation, microbial cultivation in research and industry often requires supplementation of biotin. De novo biotin biosynthesis in yeasts is not fully understood, which hinders attempts to optimize the pathway in these industrially relevant microorganisms. Previous work based on laboratory evolution of Saccharomyces cerevisiae for biotin prototrophy identified Bio1, whose catalytic function remains unresolved, as a bottleneck in biotin synthesis. This study aimed at eliminating this bottleneck in the S. cerevisiae laboratory strain CEN.PK113-7D. A screening of 35 Saccharomycotina yeasts identified six species that grew fast without biotin supplementation. Overexpression of the S. cerevisiaeBIO1 (ScBIO1) ortholog isolated from one of these biotin prototrophs, Cyberlindnera fabianii, enabled fast growth of strain CEN.PK113-7D in biotin-free medium. Similar results were obtained by single overexpression of C. fabianii BIO1 (CfBIO1) in other laboratory and industrial S. cerevisiae strains. However, biotin prototrophy was restricted to aerobic conditions, probably reflecting the involvement of oxygen in the reaction catalyzed by the putative oxidoreductase CfBio1. In aerobic cultures on biotin-free medium, S. cerevisiae strains expressing CfBio1 showed a decreased susceptibility to contamination by biotin-auxotrophic S. cerevisiae This study illustrates how the vast Saccharomycotina genomic resources may be used to improve physiological characteristics of industrially relevant S. cerevisiaeIMPORTANCE The reported metabolic engineering strategy to enable optimal growth in the absence of biotin is of direct relevance for large-scale industrial applications of S. cerevisiae Important benefits of biotin prototrophy include cost reduction during the preparation of chemically defined industrial growth media as well as a lower susceptibility of biotin-prototrophic strains to contamination by auxotrophic microorganisms. The observed oxygen dependency of biotin synthesis by the engineered strains is relevant for further studies on the elucidation of fungal biotin biosynthesis pathways.

A Uniquely Altered Oral Microbiome Composition Was Observed in Pregnant Rats With Porphyromonas gingivalis Induced Periodontal Disease.

Porphyromonas gingivalis is an anaerobic bacterium commonly found in the oral cavity and associated with the development of periodontal disease. P. gingivalis has also been linked to several systemic vascular and inflammatory diseases including poor pregnancy outcomes. Little is known about the changes in the oral flora during pregnancy in connection to P. gingivalis infection. This pilot study aims to explore changes in the oral microbiome due to P. gingivalis inoculation and pregnancy in an in vivo rat model of periodontal disease. A metagenomic sequencing analysis targeting seven of the 16S rRNA gene variable regions was performed for oral samples collected at the following time points: baseline control (week 0), P. gingivalis inoculated (week 11), P. gingivalis inoculated and pregnant rat at necropsy (week 16). A second set of animals were also sampled to generate a sham-inoculated (week 11) control group. We found that the rat oral microbiome profiles were more similar to that of the human oral cavity compared to previous reports targeting one or two 16S variable regions. Overall, there appears to be a relatively stable core microbiome in the oral cavity. As expected, P. gingivalis induced periodontal disease resulted in oral microbiome dysbiosis. During pregnancy, some aspects of the oral microbiome shifted toward a more baseline-like profile. However, population analyses in terms of dissimilarity measures and especially metagenomic based predictions of select characteristics such as cell morphology, oxygen requirement, and major metabolite synthesis showed that pregnancy did not restore the composition of the oral microbiome. Rather, a uniquely altered oral microbiome composition was observed in pregnant rats with pre-established periodontal disease.

Late onset oxygen requirement following neonatal therapeutic hypothermia.

AIM: To investigate the characteristics of infants with neonatal encephalopathy (NE) receiving therapeutic hypothermia (TH) who developed late onset oxygen requirement during or after rewarming. METHODS: Infants were stratified by receiving (a) new onset isolated oxygen requirements during or after rewarming; (b) no respiratory support during hospital stay; and (c) invasive and/or non-invasive respiratory support before or during cooling. RESULTS: Of 136 infants treated with TH, 49 (36%) did not require any respiratory support, and 78 (57.4%) received invasive or non-invasive support before or during cooling. Nine infants (6.6%) developed late onset oxygen requirement. The late onset oxygen requirement started at median age of 3.8 days (IQR 3.6-5.2) and ended at median 7.5 days (IQR 5.8-12.7). Total hours of O2 exposure were median 62.0 (IQR 24.4-112.6). Maximum support was low-flow nasal cannula from 100% oxygen source with a flow rate of 40-250 mL/min. Infants in this group had higher Apgar scores, milder metabolic acidosis and no seizures. Three infants had diagnostic investigations without significant findings. CONCLUSION: A small percentage of neonates with NE developed late onset oxygen requirement during or after rewarming. Late oxygen requirement was associated with evidence of less severe perinatal hypoxia-ischaemia.

Anaerobic growth of Saccharomyces cerevisiae CEN.PK113-7D does not depend on synthesis or supplementation of unsaturated fatty acids.

In Saccharomyces cerevisiae, acyl-coenzyme A desaturation by Ole1 requires molecular oxygen. Tween 80, a poly-ethoxylated sorbitan-oleate ester, is therefore routinely included in anaerobic growth media as a source of unsaturated fatty acids (UFAs). During optimization of protocols for anaerobic bioreactor cultivation of this yeast, we consistently observed growth of the laboratory strain S. cerevisiae CEN.PK113-7D in media that contained the anaerobic growth factor ergosterol, but lacked UFAs. To minimize oxygen contamination, additional experiments were performed in an anaerobic chamber. After anaerobic precultivation without ergosterol and Tween 80, strain CEN.PK113-7D and a congenic ole1Δ strain both grew during three consecutive batch-cultivation cycles on medium that contained ergosterol, but not Tween 80. During these three cycles, no UFAs were detected in biomass of cultures grown without Tween 80, while contents of C10 to C14 saturated fatty acids were higher than in biomass from Tween 80-supplemented cultures. In contrast to its UFA-independent anaerobic growth, aerobic growth of the ole1Δ strain strictly depended on Tween 80 supplementation. This study shows that the requirement of anaerobic cultures of S. cerevisiae for UFA supplementation is not absolute and provides a basis for further research on the effects of lipid composition on yeast viability and robustness.

Aerobic prokaryotes do not have higher GC contents than anaerobic prokaryotes, but obligate aerobic prokaryotes have.

BACKGROUND: Among the four bases, guanine is the most susceptible to damage from oxidative stress. Replication of DNA containing damaged guanines results in G to T mutations. Therefore, the mutations resulting from oxidative DNA damage are generally expected to predominantly consist of G to T (and C to A when the damaged guanine is not in the reference strand) and result in decreased GC content. However, the opposite pattern was reported 16 years ago in a study of prokaryotic genomes. Although that result has been widely cited and confirmed by nine later studies with similar methods, the omission of the effect of shared ancestry requires a re-examination of the reliability of the results. RESULTS: When aerobic and obligate aerobic prokaryotes were mixed together and anaerobic and obligate anaerobic prokaryotes were mixed together, phylogenetic controlled analyses did not detect significant difference in GC content between aerobic and anaerobic prokaryotes. This result is consistent with two generally neglected studied that had accounted for the phylogenetic relationship. However, when obligate aerobic prokaryotes were compared with aerobic prokaryotes, anaerobic prokaryotes, and obligate anaerobic prokaryotes separately using phylogenetic regression analysis, a significant positive association was observed between aerobiosis and GC content, no matter it was calculated from whole genome sequences or the 4-fold degenerate sites of protein-coding genes. Obligate aerobes have significantly higher GC content than aerobes, anaerobes, and obligate anaerobes. CONCLUSIONS: The positive association between aerobiosis and GC content could be attributed to a mutational force resulting from incorporation of damaged deoxyguanosine during DNA replication rather than oxidation of the guanine nucleotides within DNA sequences. Our results indicate a grade in the aerobiosis-associated mutational force, strong in obligate aerobes, moderate in aerobes, weak in anaerobes and obligate anaerobes.

Use of Primary Rat Hepatocytes for Prediction of Drug-Induced Mitochondrial Dysfunction.

Mitochondrial dysfunction plays a central role in drug-induced liver injury. To evaluate drug-induced mitochondrial impairment, several isolated mitochondria- or cell line-based assays have been reported. Among them, culturing HepG2 cells in galactose provides a remarkable method to assess mitochondrial toxicity by activating mitochondrial aerobic respiration. We applied this assay to primary rat hepatocytes by culturing cells in galactose and hyperoxia to enhance the evaluation of metabolism-related drug-induced mitochondrial toxicity. Conventional culture of primary hepatocytes under high-glucose and hypoxic conditions could force cells to switch energy generation to glycolysis. By contrast, cells cultured in galactose and hyperoxia could maintain energy generation from mitochondrial aerobic respiration, which is consistent with physiological conditions, and consequently improve the susceptibility of cells to mitochondrial toxicants. Measuring the toxicities of test compounds in primary rat hepatocytes cultured in modified conditions provides a useful model to identify mitochondrial dysfunction-mediated drug-induced hepatotoxicity. © 2017 by John Wiley & Sons, Inc.

Pulmonary rehabilitation for COPD improves exercise time rather than exercise tolerance: effects and mechanisms.

BACKGROUND: COPD patients undergoing pulmonary rehabilitation (PR) show various responses. The purpose of this study was to investigate the possible mechanisms and predictors of the response to PR in COPD patients. METHODS: Thirty-six stable COPD patients underwent PR including a 4-week high-intensity exercise training program, and they were evaluated by cardiopulmonary exercise testing. All patients (mean age 69 years, severe and very severe COPD 94%) were classified into four groups by whether the exercise time (Tex) or the peak oxygen uptake [Formula: see text] increased after PR: two factors increased (both the Tex and the peak [Formula: see text] increased); two factors decreased; time only increased (the Tex increased, but the peak [Formula: see text] economized); and [Formula: see text] only increased (the Tex decreased, but the peak [Formula: see text] increased). Within all patients, the relationships between baseline variables and the post-to-pre-change ratio of the time-slope, Tex/(peak minus resting [Formula: see text]), were investigated. RESULTS: Compared with the two factors increased group (n=11), in the time only increased group (n=18), the mean differences from pre-PR at peak exercise in 1) minute ventilation [Formula: see text] (P=0.004), [Formula: see text] (P<0.0001), and carbon dioxide output [Formula: see text] (P<0.0001) were lower, 2) [Formula: see text]/ [Formula: see text] (P=0.034) and [Formula: see text]/ [Formula: see text] (P=0.006) were higher, and 3) the dead space/tidal volume ratio (VD/VT) and the dyspnea level were similar. After PR, there was no significant difference in the ratio of the observed peak heart rate (HR) to the predicted peak HR (220 - age [years]) between the two groups. A significant negative correlation with the baseline time-slope (r=-0.496, P=0.002) and a positive correlation with the baseline body mass index (BMI) (r=0.496, P=0.002) were obtained. CONCLUSIONS: PR in COPD patients improves Tex rather than exercise tolerance, economizing oxygen requirements, resulting in reduced ventilatory requirements without cardiac loads followed by reduced exertional dyspnea. In addition, the time-slope and BMI could be used to predict PR responses beforehand.

Assessment of mitochondrial dysfunction-related, drug-induced hepatotoxicity in primary rat hepatocytes.

Evidence that mitochondrial dysfunction plays a central role in drug-induced liver injury is rapidly accumulating. In contrast to physiological conditions, in which almost all adenosine triphosphate (ATP) in hepatocytes is generated in mitochondria via aerobic respiration, the high glucose content and limited oxygen supply of conventional culture systems force primary hepatocytes to generate most ATP via cytosolic glycolysis. Thus, such anaerobically poised cells are resistant to xenobiotics that impair mitochondrial function, and are not suitable to identify drugs with mitochondrial liabilities. In this study, primary rat hepatocytes were cultured in galactose-based medium, instead of the conventional glucose-based medium, and in hyperoxia to improve the reliance of energy generation on aerobic respiration. Activation of mitochondria was verified by diminished cellular lactate release and increased oxygen consumption. These conditions improved sensitivity to the mitochondrial complex I inhibitor rotenone. Since oxidative stress is also a general cause of mitochondrial impairment, cells were exposed to test compounds in the presence of transferrin to increase the generation of reactive oxygen species via increased uptake of iron. Finally, 14 compounds with reported mitochondrial liabilities were tested to validate this new drug-induced mitochondrial toxicity assay. Overall, the culture of primary rat hepatocytes in galactose, hyperoxia and transferrin is a useful model for the identification of mitochondrial dysfunction-related drug-induced hepatotoxicity.