Strategies Utilized by Pinus attenuata and Pinus coulteri at Low Elevations in the San Bernardino Mountains

Plants use an isohydric or an anisohydric strategy to cope with declining soil moisture availability and increasing evaporative demand. The goal of this study was to determine the physiological and structural strategies utilized by Pinus attenuata (knobcone pine) and Pinus coulteri (Coulter pine) at low elevations in the San Bernardino Mountains of California, which experienced above-average precipitation after a severe seven-year drought. Based on a previous study, it was hypothesized that P. attenuata should be isohydric and P. coulteri should be anisohydric because P. attenuata has a slower transpirational loss of water than P. coulteri. Physiological, morphological, and anatomical measurements were used to compare the responses of the two species to seasonal environmental changes and induced drought. In the field, P. coulteri had greater water potentials and maximum quantum yields of photosystem II than did P. attenuata; however, gas exchange did not differ with species. In a controlled drought study, young P. coulteri had higher water potentials and gas exchange than young P. attenuata, with P. coulteri continuing to take up CO2 two weeks after P. attenuata had ceased uptake; however, P. attenuata took up CO2 at lower water potentials than P. coulteri. Tracheid diameter was larger for P. coulteri than P. attenuata for bands of late wood only and tracheid cell wall thickness did not differ with species. The species did not differ in plant height, but P. attenuata at low elevations had the smallest diameter at breast height, indicating P. coulteri could transport and store more water where it occurred. Finally, neither species experienced extensive branch or canopy dieback due to the previous drought. In conclusion, based on their physiological responses, both species appear to be isohydric, but also display some traits of anisohydric species

Glucose transport in vesicles reconstituted from Saccharomyces cerevisiae membranes and liposomes.

Glucose transport activity was reconstituted into liposomes by the freeze-thaw-sonication procedure from unextracted Saccharomyces cerevisiae membranes and preformed phospholipid liposomes. Fluorescence-dequenching measurements with octadecylrhodamine B chloride (R18)-labeled membranes showed that the yeast membrane lipids are diluted by the liposome lipids after the freeze-thaw-sonication procedure. At lipid-to-protein ratios greater than 75:1, vesicles with single transporters were formed. Reconstituted specific activity was increased at least twofold if the liposomes contained 50 mol% cholesterol. A further increase in specific activity, from 3- to 10-fold, was achieved by fractionation of the membranes on a Renografin gradient before reconstitution. Examination of the fractions from the Renografin gradient by sodium dodecyl sulfate-gel electrophoresis showed a parallel enrichment of glucose transport activity and a number of proteins including one with an apparent Mr of ca. 60,000, which might be the glucose transporter. Finally, preliminary kinetic analysis of glucose transport activity in vesicles reconstituted at a high lipid-to-protein ratio gave a Vmax of ca. 2.8 mumol/mg of protein per min at 23 degrees C and a Km of ca. 8 mM. The latter value corresponds to the kinase-independent, low-affinity component of glucose transport observed in wild-type cells

Cardiovascular Profile of patients with COVID-19 infection admitted at a tertiary hospital

Abstract Funding Acknowledgements Type of funding sources: None. Introduction In December 2019, a novel Coronavirus disease 2019 (COVID-19) was discovered and spread rapidly worldwide. The virus spared no country in its contagiousness. The most common clinical manifestations are respiratory symptoms; but COVID-19 may induce arrhythmias, myocardial infarction, heart failure, and other cardiovascular diseases due to the systemic inflammatory response coupled with localized vascular inflammation. The study aims to provide knowledge about the clinical profile, cardiovascular complications, and clinical outcomes among adult COVID-19 patients admitted to a tertiary hospital. Methods This study is a single-centered cross-sectional retrospective study of hospitalized adult COVID-19 patients between March 2020 to May 2022. COVID-19 confirmed patients who met the inclusion criteria with clinical data upon hospitalization are followed up for occurrence of critical illness. The study's primary outcome is determining the demographic profile and clinical course of COVID-19 infection regarding cardiovascular signs and symptoms. Data were retrieved from electronic health records. All outcomes were obtained with standardized data collection forms, and clinical severity was defined based on the National Institute of Health guidelines. Results A total of 1341 hospitalized adult COVID-19 patients were admitted with a mean age of 50.41±15.92 years. More males than females account for 60.2% of the total number of patients. Hypertension is the most common comorbidity among COVID-19 patients, comprising 44% of cases, followed by diabetes at 31.9% and dyslipidemia at 11.4%. About 5.4% had coronary artery disease, followed by heart disease 6 (3.6%) and arrhythmia (0.6%). Most COVID-19 patients were smokers 12% and alcoholic beverage drinkers (11.4%). A univariate analysis associated with mortality showed diabetes mellitus (odds ratio 2.7, p = 0.029) and hypertension (odds ratio 3.4, p = 0.11). In the multiple logistic regression analysis, factors' age (OR 1.095, estimate coefficient 0.091, standard error 0.028, p-value &amp;lt;0.05) and admission duration (OR 0.906, estimate coefficient -0.099, standard error 0.028, p-value &amp;lt;0.05) were significantly associated with mortality. Based on the fitted model, older people are more likely to be deceased than younger people. The log odds for mortality increase by 0.091 units for each year. During hospital admission, 24.43% of patients developed acute COVID-19 infection, with an in-hospital case-fatality rate of 13.89%. During hospital stay, COVID-19 patients had a significant QTc (.43 ± 0.04, p«0.001). Patients admitted to Non-ICU had lower QTc (.44 ± 0.045) compared to ICU patients (.45 ± .05). Conclusion Myocardial injury and significant cardiovascular risk factors increased mortality among critically-ill COVID-19 patients. Hence, aside from risk factor modification, emphasis on cardiovascular protection should also be considered during treatment for COVID-19. </jats:sec

Risk Factors for the Development of Nosocomial Pneumonia and Its Clinical Impact in Cardiac Surgery

Abstract BackgroundThe development of nosocomial pneumonia after cardiac surgery is a significant post-operative complication that may lead to increased morbidity, mortality, and hospital cost. We aimed to identify risk factors associated with it and to determine its clinical impact in terms of in-hospital mortality and morbidity.MethodsThis is a retrospective cohort study conducted among all adult patients who underwent cardiac surgery from 2014-2019 in St. Luke’s Medical Center, Quezon City, Philippines. Baseline characteristics and possible risk factors for pneumonia were retrieved from medical records. Nosocomial pneumonia was based on the Centers for Disease Control and Prevention criteria. Clinical outcomes include in-hospital mortality and morbidity. Odds ratios from logistic regression was computed to determine risk factors associated with pneumonia using STATA 15.0.ResultsOut of 373 patients included in this study, 104 (28%) patients acquired pneumonia. Most surgeries were coronary artery bypass graft (CABG) (71.58%), followed by valve repair/replacement (29.76%). Neither age, sex, BMI, diabetes, LV dysfunction, renal dysfunction, COPD/asthma, urgency of surgery, surgical time, nor smoking showed association in the development of pneumonia. However, preoperative stay of &gt;2 days was associated with 92.3% (95%CI 18–213%) increased odds of having pneumonia (p=.009). Also, every additional hour on mechanical ventilation conferred 0.8% (95%CI, 0.3–1%) greater odds of acquiring pneumonia (p=.003).Patients who developed pneumonia had 3.9 times odds of mortality (95%CI 1.51–9.89, p=.005), 3.8 times odds of prolonged hospitalization (95%CI 1.81–7.90,p&lt;.001), 6.4 times odds of prolonged ICU stay (95%CI 3.59–11.35,p&lt;.001), and 9.5 times odds of postoperative reintubation (95%CI 3.01–29.76,p&lt;.001). ConclusionAmong adult patients undergoing cardiac surgeries, prolonged preoperative hospital stay and prolonged mechanical ventilation were both associated with an increased risk for nosocomial pneumonia. Those who developed pneumonia had worse outcomes with significantly increased in-hospital mortality, prolonged hospitalization, prolonged ICU stay, and increased postoperative re-intubation. Clinicians should therefore minimize delays in surgery to avoid unnecessary exposure to pathogenic organisms. Also, timely liberation from mechanical ventilation after surgery should be encouraged.</jats:p

Leucine transport in plasma membrane vesicles of Saccharomyces cerevisiae

AbstractYeast plasma membrane vesicles were obtained by the fusion of liposomes with purified yeast membranes by means of the freeze thaw-sonication technique. Beef heart mitochondria cytochrome-c oxidase was incorporated into the vesicles. Addition of substrate (ascorbate/TMPD/cytochrome c) generated a membrane potential negative inside, and an alkaline pH gradient inside the vesicle, that served as the driving force for leucine transport. Both ΔpH and ΔΨ could drive leucine transport. When ΔpH was increased in the presence of valinomycin and potassium, at the expense of ΔΨ, leucine uptake increased by 10%