The effects of Hh morphogen source movement on signaling dynamics.

Morphogens of the Hh family trigger gene expression changes in receiving cells in a concentration-dependent manner to regulate their identity, proliferation, death or metabolism, depending on the tissue or organ. This variety of responses relies on a conserved signaling pathway. Its logic includes a negative-feedback loop involving the Hh receptor Ptc. Here, using experiments and computational models we study and compare the different spatial signaling profiles downstream of Hh in several developing Drosophila organs. We show that the spatial distributions of Ptc and the activator transcription factor CiA in wing, antenna and ocellus show similar features, but are markedly different from that in the compound eye. We propose that these two profile types represent two time points along the signaling dynamics, and that the interplay between the spatial displacement of the Hh source in the compound eye and the negative-feedback loop maintains the receiving cells effectively in an earlier stage of signaling. These results show how the interaction between spatial and temporal dynamics of signaling and differentiation processes may contribute to the informational versatility of the conserved Hh signaling pathway.

Cold platelet transfusion: The effects of a fluid warmer on platelet function.

BACKGROUND: Recently the US Food and Drug Administration has granted variances to select blood centers to supply cold-stored platelet components (CSP). In hemorrhage resuscitation warming of blood components with approved fluid warming devices is common. STUDY DESIGN AND METHODS: Pathogen-reduced apheresis platelet units were collected and stored in one of two ways: (1) CSP-I, (2) CSP-D. CSP-I were collected and immediately stored at 1-6°C until used. CSP-D were collected and stored at 20-24°C for 5 days and transferred to storage at 1-6°C until use. Aggregometry using arachidonic acid (AA), adenosine diphosphate (ADP) and collagen as agonists was performed on the unit samples before and after the units were infused through a Ranger blood-warming device. RESULTS: CSP-I, 23 units, had very high aggregation responses to all agonists (all ≥47.6 ± 20.7). There was a statistically significant reduction in ADP-induced aggregometry results from 55.1 ± 23.2 before compared to 33.5 ± 14.6 following infusion of the PLT through the blood warmer (p < .001). There were no differences in AA and collagen aggregometry results before and after the infusion of the platelets through the blood warmer. CSP-D had 5 of the 15 units with visible clotting in the bag. The 10 CSP-Ds studied had lower aggregation than all agonists before and after infusion through the blood-warming device (all ≤49.9 ± 35.9). CONCLUSION: We detected a statistically significant reduction in ADP-induced aggregometry in CSP-I run through a Ranger blood-warming device with no change with AA or collagen agonist aggregometry.

Performance evaluation of Trichoderma reseei in tolerance and biodegradation of diuron herbicide in agar plate, liquid culture and solid-state fermentation.

The present study evaluated the performance of the fungus Trichoderma reesei to tolerate and biodegrade the herbicide diuron in its agrochemical presentation in agar plates, liquid culture, and solid-state fermentation. The tolerance of T. reesei to diuron was characterized through a non-competitive inhibition model of the fungal radial growth on the PDA agar plate and growth in liquid culture with glucose and ammonium nitrate, showing a higher tolerance to diuron on the PDA agar plate (inhibition constant 98.63 mg L-1) than in liquid culture (inhibition constant 39.4 mg L-1). Diuron biodegradation by T. reesei was characterized through model inhibition by the substrate on agar plate and liquid culture. In liquid culture, the fungus biotransformed diuron into 3,4-dichloroaniline using the amide group from the diuron structure as a carbon and nitrogen source, yielding 0.154 mg of biomass per mg of diuron. A mixture of barley straw and agrolite was used as the support and substrate for solid-state fermentation. The diuron removal percentage in solid-state fermentation was fitted by non-multiple linear regression to a parabolic surface response model and reached the higher removal (97.26%) with a specific aeration rate of 1.0 vkgm and inoculum of 2.6 × 108 spores g-1. The diuron removal in solid-state fermentation by sorption on barley straw and agrolite was discarded compared to the removal magnitude of the biosorption and biodegradation mechanisms of Trichoderma reesei. The findings in this work about the tolerance and capability of Trichoderma reesei to remove diuron in liquid and solid culture media demonstrate the potential of the fungus to be implemented in bioremediation technologies of herbicide-polluted sites.

A mixed methods study of perceptions of bias among neonatal intensive care unit staff.

BACKGROUND: Inequity in neonatology may be potentiated within neonatal intensive care units (NICUs) by the effects of bias. Addressing bias can lead to improved, more equitable care. Understanding perceptions of bias can inform targeted interventions to reduce the impact of bias. We conducted a mixed methods study to characterize the perceptions of bias among NICU staff. METHODS: Surveys were distributed to all staff (N = 245) in a single academic Level IV NICU. Respondents rated the impact of bias on their own and others' behaviors on 5-point Likert scales and answered one open-ended question. Kruskal-Wallis test (KWT) and Levene's test were used for quantitative analysis and thematic analysis was used for qualitative analysis. RESULTS: We received 178 responses. More respondents agreed that bias had a greater impact on others' vs. their own behaviors (KWT p < 0.05). Respondents agreed that behaviors were influenced more by implicit than explicit biases (KWT p < 0.05). Qualitative analysis resulted in nine unique themes. CONCLUSIONS: Staff perceive a high impact of bias across different domains with increased perceived impact of implicit vs. explicit bias. Staff perceive a greater impact of others' biases vs. their own. Mixed methods studies can help identify unique, unit-responsive approaches to reduce bias. IMPACT: Healthcare staff have awareness of bias and its impact on their behaviors with patients, families, and staff. Healthcare staff believe that implicit bias impacts their behaviors more than explicit bias, and that they have less bias than others. Healthcare staff have ideas for strategies and approaches to mitigate the impact of bias. Mixed method studies are effective ways of understanding environment-specific perceptions of bias, and contextual assets and barriers when creating interventions to reduce bias and improve equity. Generating interventions to reduce the impact of bias in healthcare requires a context-specific understanding of perceptions of bias among staff.

Biomarker-Concordant Steroid Administration in Severe Coronavirus Disease-2019.

BACKGROUND: Although corticosteroids have become the standard of care for patients with coronavirus disease-2019 (COVID-19) on supplemental oxygen, there is growing evidence of differential treatment response. This study aimed to evaluate if there was an association between biomarker-concordant corticosteroid treatment and COVID-19 outcomes. METHODS: This registry-based cohort study included adult COVID-19 hospitalized patients between January 2020 and December 2021 from 109 institutions. Patients with available C-reactive protein (CRP) levels within 48 h of admission were evaluated. Those on steroids before admission, stayed in the hospital for <48 h, or were not on oxygen support were excluded. Corticosteroid treatment was biomarker-concordant if given with high baseline CRP ≥150 mg/L or withheld with low CRP (<150 mg/L) and vice-versa was considered discordant (low CRP with steroids, high CRP without steroids). Hospital mortality was the primary outcome. Sensitivity analyses were conducted using varying CRP level thresholds. The model interaction was tested to determine steroid effectiveness with increasing CRP levels. RESULTS: Corticosteroid treatment was biomarker-concordant in 1778 (49%) patients and discordant in 1835 (51%). The concordant group consisted of higher-risk patients than the discordant group. After adjusting for covariates, the odds of in-hospital mortality were significantly lower in the concordant group than the discordant (odds ratio [95% confidence interval (C.I.)] = 0.71 [0.51, 0.98]). Similarly, adjusted mortality difference was significant at the CRP thresholds of 100 and 200 mg/L (odds ratio [95% C.I.] = 0.70 [0.52, 0.95] and 0.57 [0.38, 0.85], respectively), and concordant steroid use was associated with lower need for invasive ventilation for 200 mg/L threshold (odds ratio [95% C.I.] = 0.52 [0.30, 0.91]). In contrast, no outcome benefit was observed at CRP threshold of 50. When the model interaction was tested, steroids were more effective at reducing mortality as CRP levels increased. CONCLUSION: Biomarker-concordant corticosteroid treatment was associated with lower odds of in-hospital mortality in severe COVID-19.

Association of Blood Pressure Variability with Delirium in Patients with Critical Illness.

BACKGROUND: The objective was to examine the association of blood pressure variability (BPV) during the first 24 h after intensive care unit admission with the likelihood of delirium and depressed alertness without delirium ("depressed alertness"). METHODS: This retrospective, observational, cohort study included all consecutive adult patients admitted to an intensive care unit at Mayo Clinic, Rochester, Minnesota, from July 1, 2004, through October 31, 2015. The primary outcomes were delirium and delirium-free days, and the secondary outcomes included depressed alertness and depressed alertness-free days. Logistic regression was performed to determine the association of BPV with delirium and depressed alertness. Proportional odds regression was used to assess the association of BPV with delirium-free days and depressed alertness-free days. RESULTS: Among 66,549 intensive care unit admissions, delirium was documented in 20.2% and depressed alertness was documented in 24.4%. Preserved cognition was documented in 55.4% of intensive care unit admissions. Increased systolic and diastolic BPV was associated with an increased odds of delirium and depressed alertness. The magnitude of the association per 5-mm Hg increase in systolic average real variability (the average of absolute value of changes between consecutive systolic blood pressure readings) was greater for delirium (odds ratio 1.34; 95% confidence interval 1.29-1.40; P < 0.001) than for depressed alertness (odds ratio 1.06; 95% confidence interval 1.02-1.10; P = 0.004). Increased systolic and diastolic BPV was associated with fewer delirium-free days but not with depressed alertness-free days. CONCLUSIONS: BPV in the first 24 h after intensive care unit admission is associated with an increased likelihood of delirium and fewer delirium-free days.

Dynamic Hh signalling can generate temporal information during tissue patterning.

The differentiation of tissues and organs requires that cells exchange information in space and time. Spatial information is often conveyed by morphogens: molecules that disperse across receiving cells to generate signalling gradients. Cells translate such concentration gradients into space-dependent patterns of gene expression and cellular behaviour. But could morphogen gradients also convey developmental time? Here, by investigating the developmental role of Hh on a component of the Drosophila visual system, the ocellar retina, we have discovered that ocellar cells use the non-linear gradient of Hh as a temporal cue, collectively performing the biological equivalent of a mathematical logarithmic transformation. In this way, a morphogen diffusing from a non-moving source is decoded as a wave of differentiating photoreceptors that travels at constant speed throughout the retinal epithelium.

Association of hypothyroidism with outcomes in hospitalized adults with COVID-19: Results from the International SCCM Discovery Viral Infection and Respiratory Illness Universal Study (VIRUS): COVID-19 Registry.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) is associated with high rates of morbidity and mortality. Primary hypothyroidism is a common comorbid condition, but little is known about its association with COVID-19 severity and outcomes. This study aims to identify the frequency of hypothyroidism in hospitalized patients with COVID-19 as well as describe the differences in outcomes between patients with and without pre-existing hypothyroidism using an observational, multinational registry. METHODS: In an observational cohort study we enrolled patients 18 years or older, with laboratory-confirmed severe acute respiratory syndrome coronavirus-2 infection between March 2020 and February 2021. The primary outcomes were (1) the disease severity defined as per the World Health Organization Scale for Clinical Improvement, which is an ordinal outcome corresponding with the highest severity level recorded during a patient's index COVID-19 hospitalization, (2) in-hospital mortality and (3) hospital-free days. Secondary outcomes were the rate of intensive care unit (ICU) admission and ICU mortality. RESULTS: Among the 20,366 adult patients included in the study, pre-existing hypothyroidism was identified in 1616 (7.9%). The median age for the Hypothyroidism group was 70 (interquartile range: 59-80) years, and 65% were female and 67% were White. The most common comorbidities were hypertension (68%), diabetes (42%), dyslipidemia (37%) and obesity (28%). After adjusting for age, body mass index, sex, admission date in the quarter year since March 2020, race, smoking history and other comorbid conditions (coronary artery disease, hypertension, diabetes and dyslipidemia), pre-existing hypothyroidism was not associated with higher odds of severe disease using the World Health Organization disease severity index (odds ratio [OR]: 1.02; 95% confidence interval [CI]: 0.92, 1.13; p = .69), in-hospital mortality (OR: 1.03; 95% CI: 0.92, 1.15; p = .58) or differences in hospital-free days (estimated difference 0.01 days; 95% CI: -0.45, 0.47; p = .97). Pre-existing hypothyroidism was not associated with ICU admission or ICU mortality in unadjusted as well as in adjusted analysis. CONCLUSIONS: In an international registry, hypothyroidism was identified in around 1 of every 12 adult hospitalized patients with COVID-19. Pre-existing hypothyroidism in hospitalized patients with COVID-19 was not associated with higher disease severity or increased risk of mortality or ICU admissions. However, more research on the possible effects of COVID-19 on the thyroid gland and its function is needed in the future.

Hemodynamics in Patients With Pheochromocytoma or Paraganglioma Undergoing Non-neuroendocrine Operations.

INTRODUCTION: Surgical resection of pheochromocytoma and paraganglioma (PPGL) may be associated with excessive hemodynamic variability. Whether hemodynamic variability occurs in patients with undiagnosed PPGL undergoing unrelated, non-neuroendocrine, operations is unknown. METHODS: We identified patients who underwent non-neuroendocrine surgical procedures up to 5 y before pathologic diagnosis of PPGL. For each PPGL, two non-PPGL patients were matched based on sex, age, type, and year of operation. Electronic medical records were reviewed for intraoperative blood pressures, heart rates, and hemodynamic variability was assessed with range (maximum-minimum), standard deviation, coefficient of variation, and average real variability. RESULTS: Thirty-seven PPGL patients underwent operations preceding the diagnosis of PPGL: 25 pheochromocytomas, 11 paragangliomas, and one metastatic pheochromocytoma. Median interquartile range tumor size at diagnosis was 35 mm (23 to 60). The time from index operation to PPGL diagnosis was ≤12 mo in 21 (56.8%) patients. In 23 (62.2%) patients, the subsequently diagnosed PPGL was functional. Fifteen (40.5%) PPGL and 20 (27.0%) control patients were preoperatively treated for hypertension (P = 0.149). Maximum intraoperative systolic BP was >180 mmHg for 4 (10.8%) PPGL patients and 3 (4.1%) controls (P = 0.219). Two PPGL patients had intraoperative systolic BP >230 mmHg. No significant differences were found with all other measures of intraoperative hemodynamic variability. Similarly, in secondary analysis there was no significant difference in intraoperative hemodynamic variability between biochemically active PPGL and their respective controls. CONCLUSIONS: Patients with undiagnosed PPGL undergoing a wide variety of non-neuroendocrine operations had intraoperative hemodynamic variability comparable to non-PPGL patients undergoing the same type of procedures.

Incidence and Outcomes of Life-Threatening Events During Hospitalization: A Retrospective Study of Patients Treated with Naloxone.

BACKGROUND: We describe the clinical course of medical and surgical patients who received naloxone on general hospital wards for suspected opioid-induced respiratory depression (OIRD). METHODS: From May 2018 through October 2020, patients who received naloxone on hospital wards were identified and their records reviewed for incidence and clinical course. RESULTS: There were 86,030 medical and 106,807 surgical admissions. Naloxone was administered to 99 (incidence 11.5 [95% confidence interval 9.4-14.0] per 10,000 admissions) medical and 63 (5.9 [95% confidence interval 4.5-7.5]) surgical patients (P < 0.001). Median oral morphine equivalents administered within 24 hours before naloxone were 32 [15, 64] and 60 [32, 88] mg for medical and surgical patients, respectively (P = 0.002). The rapid response team was activated in 69 (69.7%) vs 42 (66.7%) and critical care transfers in 51 (51.5%) vs 30 (47.6%) medical and surgical patients respectively. The number of in-hospital deaths was 21 (21.2%) vs two (3.2%) and the number of discharges to hospice 12 (12.1%) vs one (1.6%) for medical and surgical patients, respectively (P = 0.001). Naloxone did not reverse OIRD in 38 (23%) patients, and these patients had more transfers to the intensive care unit and a higher 30-day mortality rate. CONCLUSION: Medical inpatients are more likely to suffer OIRD than are surgical inpatients despite lower opioid doses. Definitive OIRD was confirmed in 77% of patients because of immediate naloxone response, whereas 23% of patients did not respond, and this subset was more likely to need a higher level of care and had a higher 30-day mortality rate. Careful monitoring of mental and respiratory variables is necessary when opiates are used in hospital.

Myocardial Infarction and Cardiac Arrest in a Patient With Severe Undiagnosed Hypothyroidism During Bronchoscopy.

Thyroid hormones have an integral role in cardiac homeostasis, and hypothyroidism may be associated with impaired myocardial contractility, altered endothelial function, and blunted response to catecholamines. Herein, the case of a patient with undiagnosed severe hypothyroidism, who developed an acute myocardial infarction and cardiac arrest during sedation for bronchoscopy, is described. He required prolonged resuscitation, which included coronary catheterization and placement of an intra-aortic balloon pump. The resuscitation was noteworthy for blunted physiologic responses to large doses of epinephrine; in particular, persistent bradycardia without evidence of conduction abnormalities. On admission to the intensive care unit, he was hypothermic (31.4°C), bradycardic, and hypotensive. Laboratory investigations revealed profound hypothyroidism, and thyroid hormone replacement was initiated. Within hours of initiation of thyroid hormone replacement, the need for vasopressor support was reduced. He had a complete recovery and was discharged home neurologically intact. The authors of the present report believe that this favorable neurologic outcome could be attributed to efficient resuscitation, prompt coronary revascularization, and profound hypothermia likely related to a hypothyroidism-associated hypometabolic state.

Urine output and acute kidney injury following laparoscopic pancreas operations.

BACKGROUND: This study aims to assess if intraoperative urine output is associated with acute kidney injury (AKI) during laparoscopic pancreas surgery. METHODS: Medical records of adult patients who underwent laparoscopic pancreas surgery from 2010 to 2020 were reviewed to identify patients who experienced AKI (creatinine increase of 0.3 mg/dL within 72 h). Surgeries were classified as with 'vascular reconstruction' (e.g. Whipple, total pancreatectomy) versus 'without reconstruction' (e.g., distal pancreatectomy). RESULTS: Included were 365 patients (221 with and 114 without reconstruction), and 42 (11.4%) developed AKI (32 [14.5%] reconstruction and 10 [6.9%] without reconstruction (P = 0.164)). The median urine output for AKI group was 0.79 [0.43, 1.15] mL/kg/h and 0.88 [0.55, 1.53] mL/kg/h for non-AKI group, P = 0.121. Urine output between AKI and non-AKI did not vary among reconstruction cases (P = 0.383), but was lower in AKI patients without reconstruction (P = 0.047). Older age, preexisting kidney disease, higher disease burden, and intraoperative hypotension were associated with AKI. Postoperative course was more complicated for AKI patients including rates of pancreatic fistulas and mortality. CONCLUSION: Incidence of AKI increases with more extensive surgery, but is not associated with low urine output. However, low urine output was associated with AKI in patients undergoing operation without reconstruction.

PolyGlcNAc-containing exopolymers enable surface penetration by non-motile Enterococcus faecalis.

Bacterial pathogens have evolved strategies that enable them to invade tissues and spread within the host. Enterococcus faecalis is a leading cause of local and disseminated multidrug-resistant hospital infections, but the molecular mechanisms used by this non-motile bacterium to penetrate surfaces and translocate through tissues remain largely unexplored. Here we present experimental evidence indicating that E. faecalis generates exopolysaccharides containing ß-1,6-linked poly-N-acetylglucosamine (polyGlcNAc) as a mechanism to successfully penetrate semisolid surfaces and translocate through human epithelial cell monolayers. Genetic screening and molecular analyses of mutant strains identified glnA, rpiA and epaX as genes critically required for optimal E. faecalis penetration and translocation. Mechanistically, GlnA and RpiA cooperated to generate uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) that was utilized by EpaX to synthesize polyGlcNAc-containing polymers. Notably, exogenous supplementation with polymeric N-acetylglucosamine (PNAG) restored surface penetration by E. faecalis mutants devoid of EpaX. Our study uncovers an unexpected mechanism whereby the RpiA-GlnA-EpaX metabolic axis enables production of polyGlcNAc-containing polysaccharides that endow E. faecalis with the ability to penetrate surfaces. Hence, targeting carbohydrate metabolism or inhibiting biosynthesis of polyGlcNAc-containing exopolymers may represent a new strategy to more effectively confront enterococcal infections in the clinic.

Pediatric multisystem SARS COV2 with versus without cardiac involvement: a multicenter study from Latin America.

Latin America (LATAM) children offer special insight into Severe Acute Respiratory Syndrome Coronavirus 2 (SARS COV2) due to high-risk race/ethnicity, variability in medical resources, diverse socioeconomic background, and numerous involved organ systems. This multinational study of LATAM youth examined the distinguishing features of acute or late multisystem SARS COV2 with versus without cardiac involvement. A consecutive sample of youth 0-18 years old (N = 98;50% male) presenting with multisystem SARS COV2 to 32 centers in 10 Latin American countries participating in a pediatric cardiac multi-imaging society were grouped as with versus without cardiac involvement, defined as abnormal echocardiographic findings or arrhythmia. Collected clinical data were analyzed by Student's t-test or Fisher's exact test. Cardiac (N = 48, 50% male) versus no cardiac (N = 50, 50% male) were similar in age; weight; nonrespiratory symptoms; and medical history. The cardiac group had 1 death and symptoms including coronary artery dilation, ejection fraction <50%, pericardial effusion, peripheral edema, arrhythmia, and pulmonary artery thrombus. The cardiac group had higher risk of ICU admission (77% vs 54%, p = 0.02); invasive ventilation (23% vs 4%,p = 0.007); vasoactive infusions (27% vs 4%, p = 0.002); prominent respiratory symptoms (60% vs 36%, p < 0.03); abnormal chest imaging (69% vs 34%, p = 0.001); troponin (33% vs 12%, p = 0.01); alanine aminotransferase (33% vs 12%, p = 0.02); and thrombocytopenia (46% vs 22%, p = 0.02). Receiver operating curve analysis showed that abnormal laboratories had 94% sensitivity and 98% negative predictive value on the need for ICU interventions.Conclusion: In LATAM children with multisystem SARS COV2, cardiac involvement was prevalent. Cardiac involvement was more likely to require ICU interventions, certain abnormal labs, and respiratory involvement. What is Known: • SARS COV2 can be asymptomatic in children but in some cases can have serious multisystemic involvement. • Hispanic ethnicity is purportedly at high risk of SARS COV2 in nations where they are often disadvantaged minority populations. What is New: • Latin American children presenting with multisystem SARS COV2 frequently have cardiac involvement which was associated with ICU interventions; prominent respiratory symptoms; abnormal chest X-ray; elevated troponin, ALT, and thrombocytopenia. • Elevated troponin, ALT or thrombocytopenia had high sensitivity and negative predictive value on the need for intensive care interventions.

"Eating healthy": Distrust of expert nutritional knowledge among elderly adults.

Elderly adults in southern Ecuador often distrust nutritionists' advice when implementing changes to their dietary practices. This distrust is no overt disregard for expert nutritional knowledge but rather the result of structural and situated practices that combine suspicion, misinformation, financial limitations, and family care. In this article, we examine eating practices among elderly adults in southern Ecuador in order to understand how nutrition distrust is constructed. In doing so, our aim is to understand how elderly adults incorporate-or not-expert nutritional knowledge into their eating practices. By ethnographically documenting daily eating practices among elderly adults in their homes, alongside expert nutritional discourses, our findings reveal that there is first, a local understanding of "eating healthy" connected to lived realities (e.g. farming practices, agricultural toxicity, age, education, polypharmacy, kinship ties), and second, a disconnect between expert nutritional knowledge and eating practices linked to how knowledge is produced and disseminated (e.g. power relations, scientific vocabulary, perceptions of health). Understanding how elderly adults build trust around eating can be a fertile ground for promoting more effective and suitable dietary advice among specific communities or groups like elderly adults.

Evaluation in the performance of the biodegradation of herbicide diuron to high concentrations by Lysinibacillus fusiformis acclimatized by sequential batch culture.

We evaluated and characterized the biodegradation of the herbicide diuron in its commercial form above its saturation concentration by Lysinibacillus fusiformis acclimatized by sequential batch culturing. Acclimatization was carried out in eight cycles in liquid culture, improving the capacity of L. fusiformis to remove diuron from 55.13 ± 1.3% in the first batch to 87.2 ± 0.11% in the eighth batch. Diuron biosorption was characterized with Langmuir and Freundlich isotherms, obtaining a maximum biosorption (qmax) of 0.00885 mg mg-1. In diuron biodegradation assays, a consumption substrate biomass yield (YSD/X) of 6.266 mg mg-1 was obtained, showing that biodegradation was the main mechanism in diuron removal. Diuron biodegradation by L. fusiformis was characterized by the Monod model, with a maximum specific growth rate (µmax) of 0.0245 h-1 and an affinity constant (KSD) of 344.09 mg L-1. A low accumulation of 3,4-dichloroaniline with the production of chloride ions indicated dechlorination when diuron was present at high concentrations. A phytotoxic assay conducted with Lactuca sativa showed that the toxicity of an effluent with diuron at 250 mg L-1 decreased when it was pretreated with acclimatized L. fusiformis. Acclimatization by sequential batch culturing improved the ability of L. fusiformis to biodegrade diuron at high concentrations, showing potential in the bioremediation of diuron-contaminated sites.

Risk of a syndemic between COVID-19 and dengue fever in southern Mexico.

A syndemic is the convergence of two or more diseases in the same space and time. In Mexico, the dengue epidemic is active and predominates in areas of the Pacific and the Gulf of Mexico; in turn, the COVID-19 epidemic severely affects the same areas as dengue fever. Given that both these diseases share many clinical manifestations, in areas where tropical diseases are endemic, it is important to make careful evaluations of the patient who consults for fever in order to establish a timely diagnosis. Laboratory diagnostic tests are necessary to take the pertinent measures for each patient. In Mexico, the risk of a syndemic between COVID-19 and dengue fever is high, and thus it that can collapse health systems. The states of southeastern Mexico and the Pacific region require special attention, since they have geographic, environmental and climatic conditions that favor the rapid spread of dengue and COVID-19. Simultaneous infection will worsen the epidemiological situation, and complicate the diagnosis, control and treatment of both diseases.

Una sindemia es la convergencia de dos o más enfermedades en un mismo espacio y tiempo. En México, la epidemia de dengue está activa y predomina en zonas del Pacífico y Golfo de México; por su parte, la epidemia de COVID-19 afecta severamente las mismas zonas que el dengue. Dado que estas enfermedades comparten numerosas manifestaciones clínicas, en zonas endémicas de enfermedades tropicales es importante la evaluación minuciosa del paciente que consulta por fiebre, para establecer oportunamente un diagnóstico correcto. Las pruebas de laboratorio son necesarias para llevar a cabo las medidas pertinentes en cada paciente. En México, el riesgo de sindemia de COVID-19 y dengue es alto, por lo que puede colapsar los sistemas de salud. Los estados del sureste y los colindantes con el Pacífico requieren especial atención ya que presentan condiciones geográficas, ambientales y climáticas que favorecen la rápida propagación del dengue y COVID-19. La infección simultánea empeorará la situación epidemiológica, complicará el diagnóstico, control y tratamiento de ambas enfermedades.

The Pseudomonas aeruginosa efflux pump MexGHI-OpmD transports a natural phenazine that controls gene expression and biofilm development.

Redox-cycling compounds, including endogenously produced phenazine antibiotics, induce expression of the efflux pump MexGHI-OpmD in the opportunistic pathogen Pseudomonas aeruginosa Previous studies of P. aeruginosa virulence, physiology, and biofilm development have focused on the blue phenazine pyocyanin and the yellow phenazine-1-carboxylic acid (PCA). In P. aeruginosa phenazine biosynthesis, conversion of PCA to pyocyanin is presumed to proceed through the intermediate 5-methylphenazine-1-carboxylate (5-Me-PCA), a reactive compound that has eluded detection in most laboratory samples. Here, we apply electrochemical methods to directly detect 5-Me-PCA and find that it is transported by MexGHI-OpmD in P. aeruginosa strain PA14 planktonic and biofilm cells. We also show that 5-Me-PCA is sufficient to fully induce MexGHI-OpmD expression and that it is required for wild-type colony biofilm morphogenesis. These physiological effects are consistent with the high redox potential of 5-Me-PCA, which distinguishes it from other well-studied P. aeruginosa phenazines. Our observations highlight the importance of this compound, which was previously overlooked due to the challenges associated with its detection, in the context of P. aeruginosa gene expression and multicellular behavior. This study constitutes a unique demonstration of efflux-based self-resistance, controlled by a simple circuit, in a Gram-negative pathogen.

Anthocyanin and Oil Contents, Fatty Acids Profiles and Antioxidant Activity of Mexican Landrace Avocado Fruits.

Mexican landrace avocados are naturally distributed mainly in high areas of central Mexico, where they have been produced and consumed since pre-Hispanic times. However, trees of these species are being replaced by improved varieties with greater global demand, and many species have been lost due to the destruction of their natural habitats. Many people in Mexico like to consume the pulp and peel of these fruits and have done so since pre-Hispanic times. This is because the peel of Mexican landrace avocados, unlike the peel of Hass avocados, is very thin and flavorful. The peel color may be bluish-purple or dark reddish due to the presence of anthocyanins, which are compounds with antioxidant activity. The objective of this study was to assess the oil and anthocyanin contents and to evaluate the antioxidant activity in fruits of 11 accessions collected from producing-regions of Mexico. The oil content was 16.2 to 32.3 g 100 g-1 in pulp, and the main unsaturated fatty acids were oleic, linoleic and palmitoleic acids, depending on the accession. The anthocyanin contents in peels ranged from 0.64 to 47 mg g-1 fresh weight. The highest antioxidant activity was found in the peel (53.3-307.3 mmol g-1 fresh weight). The results confirm that the pulp and peel of dark-peel Mexican landrace avocados could be important nutraceuticals for humans.