Reducing Intestinal Digestion and Absorption of Fat Using a Nature-Derived Biopolymer: Interference of Triglyceride Hydrolysis by Nanocellulose

Engineered nanomaterials are increasingly added to foods to improve quality, safety, or nutrition. Here we report the ability of ingested nanocellulose (NC) materials to reduce digestion and absorption of ingested fat. In the small intestinal phase of an acellular simulated gastrointestinal tract, the hydrolysis of free fatty acids (FFA) from triglycerides (TG) in a high-fat food model was reduced by 48.4% when NC was added at 0.75% w/w to the food, as quantified by pH stat titration, and by 40.1% as assessed by fluorometric FFA assay. Furthermore, translocation of TG and FFA across an in vitro cellular model of the intestinal epithelium was significantly reduced by the presence of 0.75% w/w NC in the food (TG by 52% and FFA by 32%). Finally, in in vivo experiments, the postprandial rise in serum TG 1 h after gavage with the high fat food model was reduced by 36% when 1.0% w/w NC was administered with the food. Scanning electron microscopy and molecular dynamics studies suggest two primary mechanisms for this effect: (1) coalescence of fat droplets on fibrillar NC (CNF) fibers, resulting in a reduction of available surface area for lipase binding and (2) sequestration of bile salts, causing impaired interfacial displacement of proteins at the lipid droplet surface and impaired solubilization of lipid digestion products. Together these findings suggest a potential use for NC, as a food additive or supplement, to reduce absorption of ingested fat and thereby assist in weight loss and the management of obesity.

Nurses´ stressors and psychological distress during the COVID-19 pandemic: The mediating role of coping and resilience

Aims

This study analyses the cross‐sectional effect of sources of stress during the peak of COVID‐19 pandemic on nurses´ psychological distress, focusing on the mediating role of coping strategies, both problem focused and emotion focused and resilience.

Design

Cross‐sectional and quantitative analyses.

Methods

Structural equation modelling was performed using survey data obtained during the period between 1 April‐25 May 2020 in a sample of 421 nurses from 39 Spanish provinces.

Results

Results confirmed that: (a) All the stressors have a significant, direct, and negative relationship with nurses´ psychological distress; (b) Emotion‐focused strategies is negatively related to nurses´ psychological distress directly and indirectly through resilience; and (c) Problem‐focused strategies is positively related to nurses´ psychological distress and negatively and indirectly through emotion‐focused strategies.

Conclusion

This study identifies an important mediation sequence of stressors on psychological distress through the simultaneous concurrent effect of Problem‐focused and Emotion‐focused strategies and resilience. It shows that enacting the two coping mechanisms and resilience resources is important to achieve an adaptive effect on nurses´ mental health.

Impact

Nurses with insufficient preparation and those with high levels of fear of contagion do not enact proper coping strategies. Thus, these nurses need special consideration due to their risk of higher vulnerability.

A randomized trial on the effect of tubing changes on hub contamination and catheter sepsis during parenteral nutrition

In previous studies the contamination of the catheter hub was found to be a common portal of entry for bacteria causing catheter-related sepsis. Since hub manipulations during tubing changes may increase the risk of contamination, a prospective trial was conducted to find out the effects of the frequency of tubing replacements on hub colonization and catheter sepsis rates. The results were compared with those obtained during an outbreak of coagulase negative staphylococci septicemia. Fifty-two patients were randomly allocated into two groups. Group A (n = 20) had the line changes every 2 days while group B (n = 32) had it replaced every 4 days. When the catheter was removed, the catheter tip and the hub were cultured by a quantitative method. Sterile, colonized, or infected hubs were equally distributed in both groups (A: 80, 15, and 5% vs B: 84, 6, and 10%). There were three episodes of catheter sepsis, one in group A and one in group B due to hub infection, and one in group B due to hematogenous seeding of the catheter tip. There were significant (p less than 0.001) differences between the trial and the historic series in respect to rates of hub colonization infection (19 vs 50%) and catheter sepsis (5.7 vs 40%). Delaying tubing changes does not increase catheter sepsis or hub contamination rates and, together with adequate hub protection, has proved to be a valuable factor in controlling an outbreak of catheter sepsis due to the coagulase negative staphylococci.

[HLA genetic polymorphisms and prognosis of patients with COVID-19]

OBJECTIVE

Different genetic polymorphisms of human leukocyte antigen (HLA) have been associated with the risk and prognosis of autoimmune and infectious diseases. The objectives of this study were to determine whether there is an association between HLA genetic polymorphisms and the susceptibility to and mortality of coronavirus disease 2019 (COVID-19) patients.

DESIGN

Observational and prospective study.

SETTING

Eight Intensive Care Units (ICU) from 6 hospitals of Canary Islands (Spain).

PATIENTS

COVID-19 patients admitted in ICU and healthy subjects.

INTERVENTIONS

Determination of HLA genetic polymorphisms.

MAIN VARIABLE OF INTEREST

Mortality at 30 days.

RESULTS

A total of 3886 healthy controls and 72 COVID-19 patients (10 non-survivors and 62 survivor patients at 30 days) were included. We found a trend to a higher rate of the alleles HLA-A*32 (p=0.004) in healthy controls than in COVID-19 patients, and of the alleles HLA-B*39 (p=0.02) and HLA-C*16 (p=0.02) in COVID-19 patients than in healthy controls; however, all these p-values were not significant after correction for multiple comparisons. Logistic regression analysis showed that the presence of certain alleles was associated with higher mortality, such as the allele HLA-A*11 after controlling for SOFA (OR=7.693; 95% CI=1.063-55.650; p=0.04) or APACHE-II (OR=11.858; 95% CI=1.524-92.273; p=0.02), the allele HLA-C*01 after controlling for SOFA (OR=11.182; 95% CI=1.053-118.700; p=0.04) or APACHE-II (OR=17.604; 95% CI=1.629-190.211; p=0.02), and the allele HLA-DQB1*04 after controlling for SOFA (OR=9.963; 95% CI=1.235-80.358; p=0.03).

CONCLUSIONS

The new finding from our preliminary study of small sample size was that HLA genetic polymorphisms could be associated with COVID-19 mortality; however, studies with a larger sample size before definitive conclusions can be drawn.

Guidelines for the prevention of ventilator-associated pneumonia and their implementation. The Spanish "Zero-VAP" bundle

BACKGROUND

"Zero-VAP" is a proposal for the implementation of a simultaneous multimodal intervention in Spanish intensive care units (ICU) consisting of a bundle of ventilator-associated pneumonia (VAP) prevention measures.

METHODS/DESIGN

An initiative of the Spanish Societies of Intensive Care Medicine and of Intensive Care Nurses, the project is supported by the Spanish Ministry of Health, and participation is voluntary. In addition to guidelines for VAP prevention, the "Zero-VAP" Project incorporates an integral patient safety program and continuous online validation of the application of the bundle. For the latter, VAP episodes and participation indices are entered into the web-based Spanish ICU Infection Surveillance Program "ENVIN-HELICS" database, which provides continuous information about local, regional and national VAP incidence rates. Implementation of the guidelines aims at the reduction of VAP to less than 9 episodes per 1000 days of mechanical ventilation. A total of 35 preventive measures were initially selected. A task force of experts used the Grading of Recommendations, Assessment, Development and Evaluation Working Group methodology to generate a list of 7 basic "mandatory" recommendations (education and training in airway management, strict hand hygiene for airway management, cuff pressure control, oral hygiene with chlorhexidine, semi-recumbent positioning, promoting measures that safely avoid or reduce time on ventilator, and discouraging scheduled changes of ventilator circuits, humidifiers and endotracheal tubes) and 3 additional "highly recommended" measures (selective decontamination of the digestive tract, aspiration of subglottic secretions, and a short course of iv antibiotic).

DISCUSSION

We present the Spanish VAP prevention guidelines and describe the methodology used for the selection and implementation of the recommendations and the organizational structure of the project. Compared to conventional guideline documents, the associated safety assurance program, the online data recording and compliance control systems, as well as the existence of a pre-defined objective are the distinct features of "Zero VAP".

Pneumonia in patients with severe burns : a classification according to the concept of the carrier state

OBJECTIVE

To establish baseline values of pneumonia incidence and mortality and to distinguish primary endogenous from secondary endogenous and exogenous pneumonias in a homogeneous patient population with severe burns.

DESIGN

Cohort study.

SETTING

A six-bed burn ICU.

PATIENTS

All patients of > or = 14 years admitted to the ICU between January 1995 and June 1996 with a total body surface area burn of > or = 20%.

INTERVENTION

Collection of data on surveillance samples from throat and rectum on admission and twice weekly afterward, and pneumonias during the ICU stay.

MEASUREMENTS AND RESULTS

Fifty-six patients fulfilled the criteria of the study. Mean age was 43 +/- 19.8 years; total body surface area burn, 41 +/- 18.2%; the area of full-thickness burn was 24 +/- 17.7%. Forty-one patients required mechanical ventilation. Twenty-seven patients (48%) experienced 37 episodes of pneumonia. Twenty-one pneumonias were of primary endogenous development, ie, caused by potential pathogens carried in the admission flora. There were 14 secondary endogenous and 2 exogenous infections caused by microorganisms acquired on the burn unit. Inhalation injury was identified in 26 patients. The pneumonia rate was two times higher in the subset of patients with inhalation injury compared with the group of patients without inhalation injury (p < 0.001). Overall mortality was 25%.

CONCLUSIONS

This study shows that pneumonia in burn patients is mainly an endogenous problem. Interventions that prevent the development of endogenous infections deserve prospective evaluation in patients with severe burns.

Prospective study on loss of signal on the first side during neuromonitoring of the recurrent laryngeal nerve in total thyroidectomy

Background

Staged thyroidectomy has been recommended when loss of the signal from intraoperative nerve monitoring is observed after first-side dissection of the recurrent laryngeal nerve. There is no high-quality evidence supporting this recommendation. In addition, it is not clear whether signal loss predicts postoperative vocal cord paralysis.

Methods

This was a prospective observational study of consecutive adult patients undergoing neuromonitored total thyroidectomy for either malignancy or multinodular goitre. The prevalence of first-side loss of signal was recorded. Surgery was completed, and vagus and laryngeal nerves on the first side were rechecked at the end of the procedure.

Results

Two-hundred and ninety patients were included. Loss of signal on the first side was noted in 16 procedures (5·5 per cent). Thyroidectomy was completed and, at retesting, 15 of 16 initially silent nerves recovered an electromyographic signal with a mean(s.d.) amplitude of 132(26) mcV. Mean time to recovery was 20·2 (range 10–35) min. In no patient was the signal lost on the opposite side. Only three of 15 nerves with a recovered signal were associated with transient vocal cord dysfunction.

Conclusion

After loss of signal of the recurrent laryngeal nerve dissected initially, there was a 90 per cent chance of intraoperative signal recovery. In this setting, judicious bilateral thyroidectomy can be performed without risk of bilateral recurrent nerve paresis.

Early non-invasive ventilation treatment for severe influenza pneumonia

The role of non-invasive ventilation (NIV) in acute respiratory failure caused by viral pneumonia remains controversial. Our objective was to evaluate the use of NIV in a cohort of (H1N1)v pneumonia. Usefulness and success of NIV were assessed in a prospective, observational registry of patients with influenza A (H1N1) virus pneumonia in 148 Spanish intensive care units (ICUs) in 2009-10. Significant variables for NIV success were included in a multivariate analysis. In all, 685 patients with confirmed influenza A (H1N1)v viral pneumonia were admitted to participating ICUs; 489 were ventilated, 177 with NIV. The NIV was successful in 72 patients (40.7%), the rest required intubation. Low Acute Physiology and Chronic Health Evaluation (APACHE) II, low Sequential Organ Failure Assessment (SOFA) and absence of renal failure were associated with NIV success. Success of NIV was independently associated with fewer than two chest X-ray quadrant opacities (OR 3.5) and no vasopressor requirement (OR 8.1). However, among patients with two or more quadrant opacities, a SOFA score ≤7 presented a higher success rate than those with SOFA score >7 (OR 10.7). Patients in whom NIV was successful required shorter ventilation time, shorter ICU stay and hospital stay than NIV failure. In patients in whom NIV failed, the delay in intubation did not increase mortality (26.5% versus 24.2%). Clinicians used NIV in 25.8% of influenza A (H1N1)v viral pneumonia admitted to ICU, and treatment was effective in 40.6% of them. NIV success was associated with shorter hospital stay and mortality similar to non-ventilated patients. NIV failure was associated with a mortality similar to those who were intubated from the start.

Ventilator-associated pneumonia with or without toothbrushing: a randomized controlled trial

Certain guidelines for the prevention of ventilator-associated pneumonia (VAP) recommend oral care with chlorhexidine, but none refer to the use of a toothbrush for oral hygiene. The role of toothbrush use has received scant attention. Thus, the objective of this study was to compare the incidence of VAP in critical care patients receiving oral care with and without manual brushing of the teeth. This was a randomized clinical trial developed in a 24-bed medical-surgical intensive care unit (ICU). Patients undergoing invasive mechanical ventilation for than 24 h were included. Patients were randomly assigned to receive oral care with or without toothbrushing. All patients received oral care with 0.12 % chlorhexidine digluconate. Tracheal aspirate samples were obtained during endotracheal intubation, then twice a week, and, finally, on extubation. There were no significant differences between the two groups of patients in the baseline characteristics. We found no statistically significant differences between the groups regarding the incidence of VAP (21 of 217 [9.7 %] with toothbrushing vs. 24 of 219 [11.0 %] without toothbrushing; odds ratio [OR] = 0.87, 95 % confidence interval [CI] = 0.469-1.615; p = 0.75). Adding manual toothbrushing to chlorhexidine oral care does not help to prevent VAP in critical care patients on mechanical ventilation.

Clinical and Genetic Features of Autosomal Dominant Alport Syndrome: A Cohort Study

RATIONALE & OBJECTIVE

Alport syndrome is a common genetic kidney disease accounting for approximately 2% of patients receiving kidney replacement therapy (KRT). It is caused by pathogenic variants in the gene COL4A3, COL4A4, or COL4A5. The aim of this study was to evaluate the clinical and genetic spectrum of patients with autosomal dominant Alport syndrome (ADAS).

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

82 families (252 patients) with ADAS were studied. Clinical, genetic, laboratory, and pathology data were collected.

OBSERVATIONS

A pathogenic DNA variant in COL4A3 was identified in 107 patients (35 families), whereas 133 harbored a pathogenic variant in COL4A4 (43 families). Digenic/complex inheritance was observed in 12 patients. Overall, the median kidney survival was 67 (95% CI, 58-73) years, without significant differences across sex (P=0.8), causative genes (P=0.6), or type of variant (P=0.9). Microhematuria was the most common kidney manifestation (92.1%), and extrarenal features were rare. Findings on kidney biopsies ranged from normal to focal segmental glomerulosclerosis. The slope of estimated glomerular filtration rate change was-1.46 (-1.66 to-1.26) mL/min/1.73m² per year for the overall group, with no significant differences between ADAS genes (P=0.2).

LIMITATIONS

The relatively small size of this series from a single country, potentially limiting generalizability.

CONCLUSIONS

Patients with ADAS have a wide spectrum of clinical presentations, ranging from asymptomatic to kidney failure, a pattern not clearly related to the causative gene or type of variant. The diversity of ADAS phenotypes contributes to its underdiagnosis in clinical practice.

Nosocomial outbreak of Pseudomonas aeruginosa infections related to a flexible bronchoscope

An outbreak of Pseudomonas aeruginosa infections affecting 17 patients was detected in the 27-bed intensive care unit (ICU) of a community hospital from 1 July to 30 September 2003. An ambidirectional cohort study was conducted to identify the risk factors for infection. Nosocomial infections were defined using the criteria of the Centers for Disease Control and Prevention. Random arbitrary polymorphic DNA-polymerase chain reaction was used for genotypic characterization. Logistic regression analyses demonstrated that case patients were more likely than non-cases to have had a longer stay in the ICU, and to have undergone mechanical ventilation and antimicrobial treatment. The multi-variate analysis identified recent bronchoscopy [risk ratio (RR) 3.8, 95% confidence interval (CI) 2.5-3.9] and exposure to an infected patient (RR 2.9, 95% CI 1.1-3.7) as independent risk factors. Molecular analysis showed that of the nine isolates available, four patients had a similar strain. The factor with the strongest influence on the risk of death was infection with P. aeruginosa (RR 2.1, 95% CI 1.0-2.4, P=0.04). A combined infection control strategy was implemented, including strict compliance with isolation precautions and recommendations for cleaning and disinfecting bronchoscopes, and a sharp reduction in the incidence of P. aeruginosa infection followed. It is thought that this outbreak was caused by patient-to-patient transmission and infection from a common source, i.e. the flexible bronchoscope.

[Recommendations of the Infectious Diseases Work Group (GTEI) of the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC) and the Infections in Critically Ill Patients Study Group (GEIPC) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) for the diagnosis and treatment of influenza A/H1N1 in seriously ill adults admitted to the Intensive Care Unit]

The diagnosis of influenza A/H1N1 is mainly clinical, particularly during peak or seasonal flu outbreaks. A diagnostic test should be performed in all patients with fever and flu symptoms that require hospitalization. The respiratory sample (nasal or pharyngeal exudate or deeper sample in intubated patients) should be obtained as soon as possible, with the immediate start of empirical antiviral treatment. Molecular methods based on nucleic acid amplification techniques (RT-PCR) are the gold standard for the diagnosis of influenza A/H1N1. Immunochromatographic methods have low sensitivity; a negative result therefore does not rule out active infection. Classical culture is slow and has low sensitivity. Direct immunofluorescence offers a sensitivity of 90%, but requires a sample of high quality. Indirect methods for detecting antibodies are only of epidemiological interest. Patients with A/H1N1 flu may have relative leukopenia and elevated serum levels of LDH, CPK and CRP, but none of these variables are independently associated to the prognosis. However, plasma LDH> 1500 IU/L, and the presence of thrombocytopenia <150 x 10(9)/L, could define a patient population at risk of suffering serious complications. Antiviral administration (oseltamivir) should start early (<48 h from the onset of symptoms), with a dose of 75 mg every 12h, and with a duration of at least 7 days or until clinical improvement is observed. Early antiviral administration is associated to improved survival in critically ill patients. New antiviral drugs, especially those formulated for intravenous administration, may be the best choice in future epidemics. Patients with a high suspicion of influenza A/H1N1 infection must continue with antiviral treatment, regardless of the negative results of initial tests, unless an alternative diagnosis can be established or clinical criteria suggest a low probability of influenza. In patients with influenza A/H1N1 pneumonia, empirical antibiotic therapy should be provided due to the possibility of bacterial coinfection. A beta-lactam plus a macrolide should be administered as soon as possible. The microbiological findings and clinical or laboratory test variables may decide withdrawal or not of antibiotic treatment. Pneumococcal vaccination is recommended as a preventive measure in the population at risk of suffering severe complications. Although the use of moderate- or low-dose corticosteroids has been proposed for the treatment of influenza A/H1N1 pneumonia, the existing scientific evidence is not sufficient to recommend the use of corticosteroids in these patients. The treatment of acute respiratory distress syndrome in patients with influenza A/H1N1 must be based on the use of a protective ventilatory strategy (tidal volume <10 ml / kg and plateau pressure <35 mmHg) and positive end-expiratory pressure set to high patient lung mechanics, combined with the use of prone ventilation, muscle relaxation and recruitment maneuvers. Noninvasive mechanical ventilation cannot be considered a technique of choice in patients with acute respiratory distress syndrome, though it may be useful in experienced centers and in cases of respiratory failure associated with chronic obstructive pulmonary disease exacerbation or heart failure. Extracorporeal membrane oxygenation is a rescue technique in refractory acute respiratory distress syndrome due to influenza A/H1N1 infection. The scientific evidence is weak, however, and extracorporeal membrane oxygenation is not the technique of choice. Extracorporeal membrane oxygenation will be advisable if all other options have failed to improve oxygenation. The centralization of extracorporeal membrane oxygenation in referral hospitals is recommended. Clinical findings show 50-60% survival rates in patients treated with this technique. Cardiovascular complications of influenza A/H1N1 are common. Such problems may appear due to the deterioration of pre-existing cardiomyopathy, myocarditis, ischemic heart disease and right ventricular dysfunction. Early diagnosis and adequate monitoring allow the start of effective treatment, and in severe cases help decide the use of circulatory support systems. Influenza vaccination is recommended for all patients at risk. This indication in turn could be extended to all subjects over 6 months of age, unless contraindicated. Children should receive two doses (one per month). Immunocompromised patients and the population at risk should receive one dose and another dose annually. The frequency of adverse effects of the vaccine against A/H1N1 flu is similar to that of seasonal flu. Chemoprophylaxis must always be considered a supplement to vaccination, and is indicated in people at high risk of complications, as well in healthcare personnel who have been exposed.

A model of cholestasis in the rat, using a microsurgical technique

An experimental model of extrahepatic cholestasis in the rat, using a microsurgical technique, is described. Sixteen days postoperatively all of the animals (n = 10) were alive and had hepatomegaly, splenomegaly, jaundice, and hyperbilirubinemia. The use of this technique prevents the development of hepatic cysts and other complications inherent in the surgical techniques of cholestasis, such as hepatopneumonic abscesses.

Neuro-immune-endocrine functional system and vascular pathology

A new interpretation of the response to injury by the nervous, immune and endocrine system is proposed, in order to integrate biochemical knowledge into the respective clinical areas. The discovery that the signaling molecules of the classical nervous, immune and endocrine systems, that is, the neurotransmitters, cytokines and hormones, respectively, are expressed and perceived by the three systems, has enabled us to establish a functional concept of these systems. The hypothetical integration of different pathological processes in a functional response made up by three phases, the immediate or nervous, intermediate or immune and late or endocrine ones, makes it possible to consider that all of them represent different forms of expression of a functional response whose meaning is always the same, that is, inflammation. If the functions that characterize each one of these three phases represent the activity of the nervous, immune and endocrine systems, the biochemical knowledge could be integrated into the functional meaning of each system.

How personal resources predict work engagement and self-rated performance among construction workers: a social cognitive perspective

Traditionally, research focussing on psychosocial factors in the construction industry has focused mainly on the negative aspects of health and on results such as occupational accidents. This study, however, focuses on the specific relationships among the different positive psychosocial factors shared by construction workers that could be responsible for occupational well-being and outcomes such as performance. The main objective of this study was to test whether personal resources predict self-rated job performance through job resources and work engagement. Following the predictions of Bandura's Social Cognitive Theory and the motivational process of the Job Demands-Resources Model, we expect that the relationship between personal resources and performance will be fully mediated by job resources and work engagement. The sample consists of 228 construction workers. Structural equation modelling supports the research model. Personal resources (i.e. self-efficacy, mental and emotional competences) play a predicting role in the perception of job resources (i.e. job control and supervisor social support), which in turn leads to work engagement and self-rated performance. This study emphasises the crucial role that personal resources play in determining how people perceive job resources by determining the levels of work engagement and, hence, their self-rated job performance. Theoretical and practical implications are discussed.

Influence of tracheostomy on the incidence of central venous catheter-related bacteremia

Although there are many studies on catheter-related infection, there are scarce data about the influence of tracheostomy in the incidence of central venous catheter-related bacteremia (CRB). In this cohort study, we found a higher incidence of CRB in patients with tracheostomy than without (11.25 vs. 1.43 per 1,000 catheter-days; odds ratio [OR] = 7.99; 95% confidence interval [CI] = 4.38-infinite; P < 0.001). Besides, we found a higher incidence of CRB in patients with tracheostomy using the jugular access compared to subclavian access (21.64 vs. 5.11 per 1,000 catheter-days; OR = 4.23; 95% CI = 1.44-infinite; P = 0.0097).

The dark and bright sides of self-efficacy in predicting learning, innovative and risky performances

The objective of this study is to analyze the different role that efficacy beliefs play in the prediction of learning, innovative and risky performances. We hypothesize that high levels of efficacy beliefs in learning and innovative performances have positive consequences (i.e., better academic and innovative performance, respectively), whereas in risky performances they have negative consequences (i.e., less safety performance). To achieve this objective, three studies were conducted, 1) a two-wave longitudinal field study among 527 undergraduate students (learning setting), 2) a three-wave longitudinal lab study among 165 participants performing innovative group tasks (innovative setting), and 3) a field study among 228 construction workers (risky setting). As expected, high levels of efficacy beliefs have positive or negative consequences on performance depending on the specific settings. Unexpectedly, however, we found no time x self-efficacy interaction effect over time in learning and innovative settings. Theoretical and practical implications within the social cognitive theory of A. Bandura framework are discussed.

Changes of cytochrome oxidase activity in rat suprachiasmatic nucleus

This paper evaluates the changes of cytochrome oxidase (CO) activity that take place in the suprachiasmatic nucleus (SCN) during the light-dark cycle. CO is a mitochondrial energy-generating enzyme used as a marker of neural oxidative metabolism. We measured CO activity using quantitative histochemistry calibrated with brain tissue standards and a computerized analysis image system. The results indicate that the CO enzyme activity changes on the basis of a circadian pattern, with the higher levels during the light phase (P < 0.0001). These changes are detected over a period of hours, in accordance with other studies on the possible short-term regulation of CO activity in the nervous system. It is, therefore, possible to apply this methodology to the study of the SCN and other brain areas which show functional rhythmicity.

An integrative salivary approach regarding palate cleansers in wine tasting

Wine sensory sessions normally involve the tasting of several samples, to remove food residues from the mouth the use of palate cleansers (PC) is needed. Until now, there is no agreement on the best PC to use during wine tasting sessions. The aim of this work is to study the relationship between the components retained in saliva after wine tasting and the remnant sensory feeling (astringency, alcohol, and acidity). For that, different common PC (water, carbonated water, and milk) were tested and saliva samples (expectorated and scraped) from nine trained panelists were collected after wine with and without PC trials. Results showed that after palate cleansing and not cleansing, astringency, alcoholic and acidity perception were influenced by time, PC and panelist. Astringency perception showed the greatest intensity in comparison to alcoholic and acidity. Milk was the only PC which reduced quantifiable polyphenols in expectorated saliva, as well as reducing astringency feelings. Although compositions of expectorated and scraped saliva correlated between them, polyphenols accumulated in the expectorated saliva significantly more. Retained polyphenols were correlated with astringency perception, but no correlation was found with salivary proteins. These findings assessed the astringency build-up effect during wine tasting due to polyphenols accumulation in saliva, remarking the importance of an adequate PC selection. All things considered, the present work confirmed the relationship between after-swallow mouthfeel perception and mouth residues instrumentally quantified. Also, milk has proven to be the most effective of the three PC. PRACTICAL APPLICATIONS: During tasting the accumulation of residues from previous wine samples tasted, could mislead the judgment of wine sensory qualities by oenologists. Therefore, between tasting samples it is highly important to choose the right PC. However, until now the selection of PC remains empirical, therefore in this work, we proposed to study the residues in saliva by using different PC and quantifying instrumentally, the wine residues. The methodology selected to quantify the wines residues in saliva was quick and easy to use. Furthermore, instrumental results were related with the sensory feeling of mouth cleanliness without considering individual panel member's preferences of PC. In this study, to remove astringency feeling, milk was shown to be the best cleanser in comparison with water, carbonated water or nothing, but oenologist/winemakers could use this instrumental methodology in saliva to select which one is the best among their current PC used.

Behaviour of nucleolar organizer regions in the different Wistar rat liver lobes

The area and number of silver-nucleolar organizer regions (Ag-NORs) in the hepatic lobes were determined in 3 male Wistar rats. There was a statistically significant increase in the percentage of Ag-NORs per nucleus in the right lateral and caudate lobe in relation to the left lateral and middle lobes. The area and number of Ag-NORs are greater in the caudate and right lateral lobes in relation to the left lateral and middle lobes. Since the Ag-NOR is a parameter which indicates hepatocytic protein synthesis, the different activity which corresponds to each lobe of the rat's liver makes it possible to assume that there is a functional heterogeneity which should be considered in the study of the hepatic regeneration according to the type of partial hepatectomy carried out.

High serum nitrates levels in non-survivor COVID-19 patients

OBJECTIVE

Higher blood nitrate and nitrite levels have been found in coronavirus disease 2019 (COVID-19) patients than in healthy subjects. The present study explores the potential association between serum nitrate levels and mortality in COVID-19 patients.

DESIGN

A prospective observation study was carried out.

SETTING

Eight Intensive Care Units (ICUs) from 6 hospitals in the Canary Islands (Spain).

PATIENTS

COVID-19 patients admitted to the ICU.

INTERVENTIONS

Determination of serum nitrate levels at ICU admission.

MAIN VARIABLE OF INTEREST

Mortality at 30 days.

RESULTS

Non-surviving (n=11) compared to surviving patients (n=42) showed higher APACHE-II (p<0.001) and SOFA scores (p=0.004), and higher serum nitrate levels (p=0.001). Logistic regression analyses showed serum nitrate levels to be associated to 30-day mortality after controlling for SOFA (OR=1.021; 95%CI=1.006-1.036; p=0.01) or APACHE-II (OR=1.023; 95%CI=1.006-1.041; p=0.01). There were no differences in the area under the curve (AUC) for mortality prediction by serum nitrate levels (AUC=83%; 95%CI=73-92%; p<0.001), APACHE II (AUC=85%; 95%CI=75-96%; p<0.001) and SOFA (AUC=78%; 95%CI=63-92%; p=0.005) based on the DeLong method. The Kaplan-Meier analysis found patients with serum nitrates levels>68.4μmol/l to have a higher mortality rate (hazard ratio=138.8; 95%CI=22.3-863.9; p<0.001).

CONCLUSIONS

The main novel finding was the association between serum nitrate levels and mortality in COVID-19 patients controlling for the SOFA or APACHE-II scores, though larger studies are needed to confirm this observation.

Rifampicin-miconazole-impregnated catheters save cost in jugular venous sites with tracheostomy

Antimicrobial-impregnated catheters are more expensive than standard catheters (S-C). A higher incidence of catheter-related bloodstream infection (CRBSI) has been found in jugular venous access with tracheostomy than without tracheostomy. The objective of this study was to determine central venous catheter (CVC)-related costs (considering only the cost of the CVC, diagnosis of CRBSI, and antimicrobial agents used to treat CRBSI) using rifampicin-miconazole-impregnated catheters (RM-C) or S-C in jugular venous access with tracheostomy. We performed a retrospective cohort study of patients admitted to the intensive care unit (ICU) with tracheostomy who received one or more jugular venous catheters. RM-C showed a lower incidence of CRBSI compared with S-C (0 vs. 20.16 CRBSI episodes/1,000 catheter-days; odds ratio=0.05; 95% confidence interval=0.001-0.32; p<0.001) and lower CVC-related costs (including the cost of the CVC, diagnosis, and treatment of CRBSI) (<euro>11.46 ± 6.25 vs. <euro>38.11 ± 77.25; p<0.001) in jugular venous access with tracheostomy. The use of RM-C could reduce CVC-related costs in jugular venous access with tracheostomy. The results of our study may contribute to clinical decision-making and selection of those patients who could benefit from the use of antimicrobial-impregnated catheters.