[Impact of days elapsed from the onset of symptoms to hospitalization in COVID-19 in-hospital mortality: Time matters]. / Impacto de los días transcurridos desde el inicio de los síntomas hasta la hospitalización en la mortalidad hospitalaria por COVID-19: el tiempo importa.

Background: COVID-19 shows different clinical and pathophysiological stages over time. Theeffect of days elapsed from the onset of symptoms (DEOS) to hospitalization on COVID-19prognostic factors remains uncertain. We analyzed the impact on mortality of DEOS to hospital-ization and how other independent prognostic factors perform when taking this time elapsedinto account. Methods: This retrospective, nationwide cohort study, included patients with confirmed COVID-19 from February 20th and May 6th, 2020. The data was collected in a standardized online datacapture registry. Univariate and multivariate COX-regression were performed in the generalcohort and the final multivariate model was subjected to a sensitivity analysis in an earlypresenting (EP; < 5 DEOS) and late presenting (LP; ≥5 DEOS) group. Results: 7915 COVID-19 patients were included in the analysis, 2324 in the EP and 5591 in theLP group. DEOS to hospitalization was an independent prognostic factor of in-hospital mortalityin the multivariate Cox regression model along with other 9 variables. Each DEOS incrementaccounted for a 4.3% mortality risk reduction (HR 0.957; 95% CI 0.93---0.98). Regarding variationsin other mortality predictors in the sensitivity analysis, the Charlson Comorbidity Index onlyremained significant in the EP group while D-dimer only remained significant in the LP group. Conclusion: When caring for COVID-19 patients, DEOS to hospitalization should be consideredas their need for early hospitalization confers a higher risk of mortality. Different prognosticfactors vary over time and should be studied within a fixed timeframe of the disease.

Impact of days elapsed from the onset of symptoms to hospitalization in COVID-19 in-hospital mortality: time matters.

BACKGROUND: COVID-19 shows different clinical and pathophysiological stages over time. The effect of days elapsed from the onset of symptoms (DEOS) to hospitalization on COVID-19 prognostic factors remains uncertain. We analyzed the impact on mortality of DEOS to hospitalization and how other independent prognostic factors perform when taking this time elapsed into account. METHODS: This retrospective, nationwide cohort study, included patients with confirmed COVID-19 from February 20th and May 6th, 2020. The data was collected in a standardized online data capture registry. Univariate and multivariate COX-regression were performed in the general cohort and the final multivariate model was subjected to a sensitivity analysis in an early presenting (EP; <5 DEOS) and late presenting (LP; ≥5 DEOS) group. RESULTS: 7915 COVID-19 patients were included in the analysis, 2324 in the EP and 5591 in the LP group. DEOS to hospitalization was an independent prognostic factor of in-hospital mortality in the multivariate Cox regression model along with other 9 variables. Each DEOS increment accounted for a 4.3% mortality risk reduction (HR 0.957; 95% CI 0.93-0.98). Regarding variations in other mortality predictors in the sensitivity analysis, the Charlson Comorbidity Index only remained significant in the EP group while D-dimer only remained significant in the LP group. CONCLUSION: When caring for COVID-19 patients, DEOS to hospitalization should be considered as their need for early hospitalization confers a higher risk of mortality. Different prognostic factors vary over time and should be studied within a fixed timeframe of the disease.

The effects of acute ethanol exposure and ageing on rat brain glutathione metabolism.

Binge alcohol consumption in adolescents is increasing, and it has been proposed that immature brain deals poorly with oxidative stress. The aim of our work was to study the effect of an acute dose of ethanol on glutathione (GSH) metabolism in frontal cortex, hippocampus and striatum of juvenile and adult rats. We have observed no change in levels of glutathione produced by acute alcohol in the three brain areas studied of juvenile and adult rats. Only in the frontal cortex the ratio of GSH/GSSG was increased in the ethanol-treated adult rats. GSH levels in the hippocampus and striatum were significantly higher in adult animals compared to young ones. Higher glutathione peroxidase (GPx) activity in adult rats was observed in frontal cortex and in striatum. Our data show an increased GSH concentration and GPx activity in different cerebral regions of the adult rat, compared to the young ones, suggesting that age-related variations of total antioxidant defences in brain may predispose young brain structures to ethanol-induced, oxidative stress-mediated tissue damage.

Diagnosis of patients with immediate hypersensitivity to beta-lactams using retest.

BACKGROUND: beta-Lactams are the drugs most frequently involved in hypersensitivity reactions mediated by immunoglobulin (Ig) E. OBJECTIVE: To evaluate a population of patients with suspected B-lactam allergy using a validated algorithm that includes specific IgE antibodies, skin testing, and/or a drug provocation test. METHODS: A total of 1032 patients with symptoms compatible with B-lactam allergy were evaluated by means of their clinical history, specific immunoglobulin (Ig) E antibody determinations (benzylpenicillin, ampicillin, and amoxicillin), and skin tests with major determinants (penicilloyl-polylysine) and minor determinants (minor determinant mixture) of benzylpenicillin, penicillin G, ampicillin, and amoxicillin-clavulanic acid. Patients whose skin test results were negative were challenged with amoxicillin-clavulanic acid. Only immediate hypersensitivity reactions were evaluated. All patients with negative study results and for whom a reaction occurred more than 1 year before were retested using the same protocol. RESULTS: A total of 170 patients (16.4%) were finally confirmed as having immediate allergic reactions to beta-lactams (62.3% by skin testing, 16.5% by specific IgE, and 21.2% by drug provocation test). The mean age of these patients was 43.3 years, and the drug most frequently involved in the reaction was amoxicillin (41.1%), followed by the combination amoxicillin-clavulanic acid (36.4%). In the remaining 22.5%, different beta-lactams were involved or the culprit drug was not known. Only mild reactions were observed after the drug provocation test. A retest was required in 23% of patients in order to confirm their hypersensitivity. CONCLUSIONS: These results indicate that a diagnostic protocol based on the combination of skin testing and in vitro determination of specific IgE antibodies plus, if required, drug provocation testing is an appropriate procedure for evaluating immediate hypersensitivity reactions to beta-lactams. Because the sensitivity of skin testing and in vitro IgE assays is not optimal and a considerable proportion of patients are tolerant, drug provocation tests are necessary to achieve the diagnosis or confirm tolerance. A large percentage of patients (23%) were diagnosed using retest.

Potential hypersensitivity due to the food or food additive content of medicinal products in Spain.

The Drug Allergy Committee of the Spanish Society of Allergology and Clinical Immunology reviewed the allergenic potential of several substances of food origin that are found in the composition of some drugs. Despite recent legislation on labeling, many labels do not clearly state whether the drug contains raw material (active ingredients, excipient, or other manufacturing intermediate) with an origin in any of the substances in the list of the 14 groups of food allergens that are subject to mandatory declaration. The objective of legislation is that the drug package, the Summary of Product Characteristics, and the patient information leaflet clearly state the food content in order to improve the safety of allergic patients. Therefore, any food or allergen derivative that must be declared should be clearly stated on the drug label. Of all the evaluated products, egg and milk derivatives are the most frequently discussed in literature reviews. The natural or synthetic origin of potentially allergenic substances such as lysozyme, casein, lactose, albumin, phosphatide, and aromatic essences should be clearly stated. Providing this information has 2 clear advantages. First, allergic reactions to drugs in patients with food allergy could be avoided (if the substances have a natural origin). Second, prescription would improve by not restricting drugs containing synthetic substances (which do not usually induce allergic reactions).

Breast cancer risk factors: PCB congeners.

The chronic effects of polychlorinated biphenyls (PCBs) are a public health concern, and a potential relationship with breast cancer has been postulated. The purpose of this study was to examine the possible relationship between PCBs and breast cancer. All women (134) treated by excision biopsy because of breast lump at Reina Sofia University Hospital, Cordoba, Spain over a period of 10 months were included in our study. They were all administered a questionnaire by interview, calculation of body mass index, histopathological examination of excised mass and chemical estimation of PCB congener levels in breast fat. The collected samples were from 65 (48.5%) women with benign lesions and 69 (51.5%) with malignant lesions. The variables associated with malignant lesions on univariate analysis were age, lactation period, overweight, PCB n-28 and PCB n-52. On the multivariate analysis PCB n-28 was found to be the most important risk factor (OR 9.6, 95% CI 3.8-24.4). Other risk factors were identified as age, drinking alcohol, low parity and overweight. If these findings can be confirmed in a large study population, however, they may have important implications for breast cancer risk.

Sequences in the -35 region of Escherichia coli rpoS-dependent genes promote transcription by E sigma S.

sigma S is an alternate sigma factor which functions with RNA polymerase to activate transcription of genes that are involved in a number of stress responses, including stationary-phase survival and osmoprotection. The similarity of the sigma S protein to sigma D (Escherichia coli's major sigma factor) in the regions thought to recognize and bind promoter sequences suggests that sigma S- and sigma D-associated RNA polymerases recognize promoter DNA in a similar manner. However, no promoter recognition sequence for sigma S holoenzyme (E sigma S) has been identified. An apparent conservation of cytosine nucleotides was noted in the -35 region of several sigma S-dependent promoters. Site-directed mutagenesis and reporter gene fusions were used to investigate the importance of the -35 cytosine nucleotides for sigma S-dependent transcription. Substitution of cytosine nucleotides for thymidine at the -35 site of the sigma D-dependent proU promoter effectively abolished transcription by E sigma D but allowed E sigma S to direct transcription from the mutant promoter. Inclusion of the sigma D consensus -10 hexamer strengthened transcription by E sigma S, demonstrating that both E sigma D and E sigma S can recognize the same -10 sequences. Conversely, replacement of -35 site cytosine nucleotides with thymidine in the sigma S-dependent osmY promoter reduced transcription by E sigma S and increased transcription by E sigma D. Our data suggest that DNA sequences in the -35 region function as part of a discriminator mechanism to shift transcription between E sigma D and E sigma S.

Promoter selectivity control of Escherichia coli RNA polymerase by ionic strength: differential recognition of osmoregulated promoters by E sigma D and E sigma S holoenzymes.

Transcription in vitro of two osmoregulated promoters, for the Escherichia coli osmB and osmY genes, was analysed using two species of RNA polymerase holoenzyme reconstituted from purified core enzyme and either sigma D (sigma 70, the major sigma in exponentially growing cells) or sigma S (sigma 38, the principal sigma at stationary growth phase). Under conditions of low ionic strength, the osmB and osmY promoters were transcribed by both E sigma D and E sigma S. Addition of up to 400 mM potassium glutamate (K glutamate), mimicking the intracellular ionic conditions under hyperosmotic stress, specifically enhanced transcription at these promoters by E sigma S but inhibited that by E sigma D. At similar high concentrations of potassium chloride (KCl), however, initiation at both these promoters was virtually undetectable. These data suggest that the RNA polymerase, E sigma S, itself can sense osmotic stress by responding to changes in intracellular K glutamate concentrations and altering its promoter selectivity in order to recognize certain osmoregulated promoters.

Two different Escherichia coli proP promoters respond to osmotic and growth phase signals.

proP of Escherichia coli encodes an active transport system for proline and glycine betaine which is activated by both hyperosmolarity and amino acid-limited growth. proP DNA sequences far upstream from the translational start site are strongly homologous to the promoter of proU, an operon that specifies another osmoregulated glycine betaine transport system. Mutation and deletion analysis of proP and primer extension experiments established that this promoter, P1, was responsible for proP's strong expression in minimal medium and its response to osmotic signals. When cells were grown in complex medium, expression from a proP-lacZ fusion was induced three- to fourfold as growth slowed and cells entered stationary phase. Stationary-phase induction was dependent on rpoS, which encodes a stationary-phase sigma factor. Deletion of 158 bp of the untranslated leader sequence between P1 and the proP structural gene abolished rpoS-dependent stationary-phase regulation. Transcription initiation detected by primer extension within this region was absent in an rpoS mutant. proP is therefore a member of the growing class of sigma S-dependent genes which respond to both stationary-phase and hyperosmolarity signals.

[Present regulation on infant and follow-on formula]. / Situación legislativa de preparados para lactantes y de continuación.

BACKGROUND: The commercialization of breast milk substitutes has had great economic transcendence, sometimes without considering the sanitary and nutritional consequences for the customer. The sanitary authorities have been implied in this matter both in the International and European fields, issuing standards and regulations for the commercialization of breast milk substitutes which have been adopted by the Spanish Regulation. The aim of this paper is comment the regulations that affect foods for breast-feeding and short age children. METHODS: This report analyzes and comments on the contents of international, european and national regulation on infant and follow-on formula. RESULTS: The regulations about Infant formula and Follow-on formula, banning the term of "humanized milk" and remarking the preference for breast feeding, which could only be substituted by sanitary professionals. This regulation deals with the appropriate chemical composition of these products, qualitative and quantitative. It includes standards for correct labeling, which should contain the appropriate information without idealizing the product Drawings and pictures showing the correct preparation are allowed. It provides for distribution and sales, as well as for correct advertising, which should be under control. This regulation also bans free samples and any other donation to particular customers or sanitary institutions. CONCLUSIONS: The present regulation on "Infant and Follow-on formulas" pursues the adequate nutrition of breast-feeding and short age children, being the protection of this kind of customers everyone's responsibility.

The Escherichia coli proU promoter element and its contribution to osmotically signaled transcription activation.

The proU operon of Escherichia coli encodes a high-affinity glycine betaine transport system which is osmotically inducible and enables the organism to recover from the deleterious effects of hyperosmotic shock. Regulation occurs at the transcriptional level. KMnO4 footprinting showed that the preponderance of transcription initiated at a single primary promoter region and that proU transcription activation did not occur differentially at alternate promoters in response to various levels of salt shock. Mutational analysis confirmed the location of the primary promoter and identified an extended -10 region required for promoter activity. Specific nucleotides within the spacer, between position -10 and position -35, were important for maximal expression, but every mutant which retained transcriptional activity remained responsive to osmotic signals. A chromosomal 90-bp minimal promoter fragment fused to lacZ was not significantly osmotically inducible. However, transcription from this fragment was resistant to inhibition by salt shock. A mutation in osmZ, which encodes the DNA-binding protein H-NS, derepressed wild-type proU expression by sevenfold but did not alter expression from the minimal promoter. The current data support a model in which the role of the proU promoter is to function efficiently at high ionic strength while other cis-acting elements receive and respond to the osmotic signal.

Genes encoding osmoregulatory proline/glycine betaine transporters and the proline catabolic system are present and expressed in diverse clinical Escherichia coli isolates.

Sixty-three clinical isolates identified as Escherichia coli, 30 from the human urinary tract and 33 derived from other human origins, were screened for proline/glycine betaine transporters similar to those that support proline catabolism and proline- or glycine betaine-based osmoregulation in E. coli K-12. Both molecular (DNA- and protein-based) analyses and physiological tests were performed. All tests were calibrated with E. coli K-12 derivatives from which genetic loci putP (encoding a proline transporter required for proline catabolism), proP, and (or) proU (loci encoding osmoregulatory proline/glycine betaine transporters) had been deleted. All clinical isolates showed both enhanced sensitivity to the toxic proline analogue azetidine-2-carboxylate on media of high osmolality and growth stimulation by glycine betaine in an artificial urine preparation of high osmolality. DNA sequences similar to the putP, proP, and proU loci of E. coli K-12 were detected by DNA amplification and (or) hybridization and protein specifically reactive with antibodies raised against the ProX protein of E. coli K-12 (a ProU constituent) was detected by western blotting in over 95% of the isolates. Two anomalous isolates were reclassified as non-E. coli on the basis of the API 20E series of tests. A protein immunochemically cross-reactive with the ProP protein of E. coli K-12 was also expressed by the clinical isolates. Since all three transporters were ubiquitous, no particular correlation between clinical origin and PutP, ProP, or ProU activity was observed. These data suggest that the transporters encoded in loci putP, proP, and proU perform housekeeping functions essential for the survival of E. coli cells in diverse habitats.

Molecular characterization of the promoter of osmY, an rpoS-dependent gene.

The osmY gene, which encodes a periplasmic protein with an apparent M(r) of 22,000, is induced by both osmotic and growth phase signals. We demonstrate here that osmY expression is regulated at the level of transcription and that transcription initiates 242 nucleotides upstream of the osmY open reading frame. Relative to the transcriptional start site, 5' deletions up to -36 did not inhibit osmY expression. 3' deletions that extended into the untranslated leader region affected the overall level of osmY::lacZ expression but did not affect inducibility. 5' and 3' deletions that extended past the transcriptional start region essentially abolished osmY expression, suggesting that there is a single promoter region. A putative promoter was identified, and its -10 region, TATATT, closely resembles the sigma 70 consensus -10 sequence, TATAAT. However, we show that osmY is not absolutely dependent on a functional sigma 70 for its expression. Since osmY expression does require rpoS (R. Hengge-Aronis, R. Lange, N. Henneberg, and D. Fischer, J. Bacteriol. 175:259-265, 1993), which encodes a stationary-phase sigma factor, sigma S (K. Tanaka, Y. Takayanagi, N. Fujita, A. Ishihama, and H. Takahashi, Proc. Natl. Acad. Sci. USA 90:3511-3515, 1993), E sigma S may be the form of RNA polymerase responsible for transcription of osmY.

Growth of Escherichia coli in human urine: role of salt tolerance and accumulation of glycine betaine.

Glycine betaine is a powerful osmoprotectant molecule present in the inner medulla of the kidney and excreted into urine. It may be responsible for the ability of Escherichia coli to grow in hypertonic urine. Also, strains of E. coli that cause urinary tract infections may be more salt-tolerant than strains from other sites. To explore these questions, 301 isolates from blood, urine, or stool and 12 representative enteric strains were examined. Tolerance varied from 0.1 to 0.7 M NaCl (median, 0.5) in minimal medium. There were no significant differences in salt tolerance by site of isolation. A salt-sensitive enteric strain that responded poorly to glycine betaine and mutant strains lacking the ability to synthesize or transport glycine betaine did not grow well in hypertonic urine. Accumulation of glycine betaine appears to be a mechanism by which E. coli can adapt to external osmotic forces and grow in hypertonic urine.

osmY, a new hyperosmotically inducible gene, encodes a periplasmic protein in Escherichia coli.

A new osmotically inducible gene in Escherichia coli, osmY, was induced 8- to 10-fold by hyperosmotic stress and 2- to 3-fold by growth in complex medium. The osmY gene product is a periplasmic protein which migrates with an apparent molecular mass of 22 kDa on sodium dodecyl sulfate-polyacrylamide gels. A genetic fusion to osmY was mapped to 99.3 min on the E. coli chromosome. The gene was cloned and sequenced, and an open reading frame was identified. The open reading frame encoded a precursor protein with a calculated molecular weight of 21,090 and a mature protein of 18,150 following signal peptide cleavage. Sequencing of the periplasmic OsmY protein confirmed the open reading frame and defined the signal peptide cleavage site as Ala-Glu. A mutation caused by the osmY::TnphoA genetic fusion resulted in slightly increased sensitivity to hyperosmotic stress.

Osmotic signal transduction to proU is independent of DNA supercoiling in Escherichia coli.

proU expression has been proposed to form part of a general stress response that is regulated by increased negative DNA supercoiling brought about by environmental signals such as osmotic or anaerobic stress (N. Ni Bhriain, C. J. Dorman, and C. F. Higgins, Mol. Microbiol. 3:933-944, 1989). However, we find that although proU-containing plasmids derived from cells grown in media of elevated osmolarity were more supercoiled than plasmids from cells grown in standard media, they did not activate proU expression in vitro. The gyrA96 mutation and anaerobic conditions are known to affect DNA supercoiling but did not alter proU expression. Finally, the gyrase inhibitors coumermycin and novobiocin did not reduce in vitro proU expression. Therefore, this evidence rules out regulation by changes in DNA superhelicity for proU in Escherichia coli.

Osmotic control of proU transcription is mediated through direct action of potassium glutamate on the transcription complex.

Osmoregulated transcription from the proU promoter of Escherichia coli has been successfully reconstituted from purified components in a simple in vitro system consisting of plasmid DNA template, RNA polymerase, and nucleotides in the absence of any other protein factor. proU transcription is stimulated by addition of high concentrations of potassium glutamate, the ionic compound accumulated in vivo during hyperosmotic stress. Transcription from the nonosmoregulated promoters beta la, lac, and pepN is inhibited under the same conditions, demonstrating the specificity of potassium glutamate as an inducer of proU transcription. proU transcription requires a circular DNA template, but stable alterations in the degree of supercoiling are unnecessary for this potassium glutamate-dependent signaling. These results agree well with previous data obtained in an S-30 coupled transcription/translation system and suggest that physiological changes in the ionic composition of the intracellular millieu can regulate gene expression.

Osmotic regulation of PhoE porin synthesis in Escherichia coli.

In Escherichia coli, adaptation to hyperosmotic conditions alters the expression of the outer membrane porins OmpF and OmpC. The amount of PhoE porin, which is normally induced by phosphate deprivation, was greatly reduced in cells adapted to high-osmolarity conditions. Osmoregulation of PhoE operated independently of the activity of the PhoR phosphate sensor and did not involve cross-talk from the homologous osmosensor EnvZ. PhoE synthesis was partially restored by additional copies of the positive regulator phoB+ and by the osmoprotectant glycine betaine.