Detection of SARS-CoV-2 in aerosols in long term care facilities and other indoor spaces with known COVID-19 outbreaks.

Coronavirus outbreaks are likely to occur in crowded and congregate indoor spaces, and their effects are most severe in vulnerable long term care facilities (LTCFs) residents. Public health officers benefit from tools that allow them to control COVID-19 outbreaks in vulnerable settings such as LTCFs, but which could be translated in the future to control other known and future virus outbreaks. This study aims to develop and test a methodology based on detection of SARS-CoV-2 in aerosol samples collected with personal pumps that could be easily implemented by public health officers. The proposed methodology was used to investigate the levels of SARS-CoV-2 in aerosol in indoor settings, mainly focusing on LTCFs, suffering COVID-19 outbreaks, or in the presence of known COVID-19 cases, and targeting the initial days after diagnosis. Aerosol samples (N = 18) were collected between November 2020 and March 2022 in Castelló (Spain) from LTCFs, merchant ships and a private home with recently infected COVID-19 cases. Sampling was performed for 24-h, onto 47 mm polytetrafluoroethylene (PTFE) and quartz filters, connected to personal pumps at 2 and 4 L/min respectively. RNA from filters was extracted and SARS-CoV-2 was determined by detection of regions N1 and N2 of the nucleocapsid gene alongside the E gene using RT-PCR technique. SARS-CoV-2 genetic material was detected in 87.5% samples. Concentrations ranged ND-19,525 gc/m3 (gene E). No genetic traces were detected in rooms from contacts that were isolated as a preventative measure. Very high levels were also measured at locations with poor ventilation. Aerosol measurement conducted with the proposed methodology provided useful information to public health officers and contributed to manage and control 12 different COVID-19 outbreaks. SARS-CoV-2 was detected in aerosol samples collected during outbreaks in congregate spaces. Indoor aerosol sampling is a useful tool in the early detection and management of COVID-19 outbreaks and supports epidemiological investigations.

Saturated and unsaturated fat diets impair hippocampal glutamatergic transmission in adolescent mice.

Consumption of high-fat diets (HFD) has been associated with neuronal plasticity deficits and cognitive disorders linked to the alteration of glutamatergic disorders in the hippocampus. As young individuals are especially vulnerable to the effects of nutrients and xenobiotics on cognition, we studied the effect of chronic consumption of saturated (SOLF) and unsaturated oil-enriched foods (UOLF) on: i) spatial memory; ii) hippocampal synaptic transmission and plasticity; and iii) gene expression of glutamatergic receptors and hormone receptors in the hippocampus of adolescent and adult mice. Our results show that both SOLF and UOLF impair spatial short-term memory. Accordingly, hippocampal synaptic plasticity mechanisms underlying memory, and gene expression of NMDA receptor subunits are modulated by both diets. On the other hand, PPARγ gene expression is specifically down-regulated in adolescent SOLF individuals and up-regulated in adult UOLF mice.

Development of concomitant diseases in COVID-19 critically ill patients. / Desarrollo de enfermedades concomitantes en pacientes críticos con COVID-19.

It may be necessary a consideration about the best approach to the acute concomitant problems that critical COVID-19 patients can develop. They require a rapid diagnosis and an early treatment by a multidisciplinary team. As a result, we would like to describe two clinical cases a patient with diagnosis of COVID-19 pneumonia with good respiratory evolution that, after extubation suffered an acalculous cholecystitis and a patient with COVID-19 pneumonia that suffered an overinfection with necrotising pneumonia that presented with haemoptysis and was finally treated with arterial embolisation by the interventional radiologist's team.

Investigating intracellular persistence of Staphylococcus aureus within a murine alveolar macrophage cell line.

OBJECTIVE: Staphylococcus aureus is a particularly difficult pathogen to eradicate from the respiratory tract. Previous studies have highlighted the intracellular capacity of S.aureus in several phagocytic and non-phagocytic cells. The aim of this study was to define S.aureus interaction within a murine alveolar macrophage cell line. METHODS: Cell line MH-S was infected with Newman strain. Molecular mechanisms involved in phagocytosis were explored. To assess whether S.aureus survives intracellularly quantitative (gentamicin protection assays and bacterial plating) and qualitative analysis (immunofluorescence microscopy) were performed. Bacterial colocalization with different markers of the endocytic pathway was examined to characterize its intracellular trafficking. RESULTS: We found that S.aureus uptake requires host actin polymerization, microtubule assembly and activation of phosphatidylinositol 3-kinase signaling. Time course experiments showed that Newman strain was able to persist within macrophages at least until 28.5 h post infection. We observed that intracellular bacteria are located inside an acidic subcellular compartment, which co-localizes with the late endosome/lysosome markers Lamp-1, Rab7 and RILP. Colocalization counts with TMR-dextran might reflect a balance between bacterial killing and intracellular survival. CONCLUSIONS: This study indicates that S.aureus persists and replicates inside murine alveolar macrophages, representing a privileged niche that can potentially offer protection from antimicrobial activity and immunological host defense mechanisms.

Trends in arsenic levels in PM10 and PM 2.5 aerosol fractions in an industrialized area.

Arsenic is a toxic element that affects human health and is widely distributed in the environment. In the area of study, the main Spanish and second largest European industrial ceramic cluster, the main source of arsenic aerosol is related to the impurities in some boracic minerals used in the ceramic process. Epidemiological studies on cancer occurrence in Spain points out the study region as one with the greater risk of cancer. Concentrations of particulate matter and arsenic content in PM10 and PM2.5 were measured and characterized by ICP-MS in the area of study during the years 2005-2010. Concentrations of PM10 and its arsenic content range from 27 to 46 µg/m(3) and from 0.7 to 6 ng/m(3) in the industrial area, respectively, and from 25 to 40 µg/m(3) and from 0.7 to 2.8 ng/m(3) in the urban area, respectively. Concentrations of PM2.5 and its arsenic content range from 12 to 14 µg/m(3) and from 0.5 to 1.4 ng/m(3) in the urban background area, respectively. Most of the arsenic content is present in the fine fraction, with ratios of PM2.5/PM10 in the range of 0.65-0.87. PM10, PM2.5, and its arsenic content show a sharp decrease in recent years associated with the economic downturn, which severely hit the production of ceramic materials in the area under study. The sharp production decrease due to the economic crisis combined with several technological improvements in recent years such as substitution of boron, which contains As impurities as raw material, have reduced the concentrations of PM10, PM2.5, and As in air to an extent that currently meets the existing European regulations.

Salvage parenchymal liver transection for patients with insufficient volume increase after portal vein occlusion -- an extension of the ALPPS approach.

BACKGROUND: Portal vein ligation (PVL) or embolization (PVE) are standard approaches to induce liver hypertrophy of the future liver remnant (FLR) prior to hepatectomy in primarily non-resectable liver tumors. However, this approach fails in about one third of patients. Recently, the new "ALPPS" approach has been described that combines PVL with parenchymal transection to induce rapid liver hypertrophy. This series explores whether isolated parenchymal transection boosts liver hypertrophy in scenarios of failed PVL/PVE. METHODS: A multicenter database with 170 patients undergoing portal vein manipulation to increase the size of the FLR was screened for patients undergoing isolated parenchymal transection as a salvage procedure. Three patients who underwent PVL/PVE with subsequent insufficient volume gain and subsequently underwent parenchymal liver transection as a salvage procedure were identified. Patient characteristics, volume increase, postoperative complications and outcomes were analyzed. RESULTS: The first patient underwent liver transection 16 weeks after failed PVL with a standardized FLR (sFLR) of 30%, which increased to 47% in 7 days. The second patient showed a sFLR of 25% 28 weeks after PVL and subsequent PVE of segment IV, which increased to 41% in 7 days after transection. The third patient underwent liver partition 8 weeks after PVE with a sFLR of 19%, which increased to 37% in six days. All patients underwent a R0 resection. CONCLUSION: Failed PVE or PVL appears to represent a good indication for the isolated parenchymal liver transection according to the newly developed ALPPS approach.

[Nosocomial urinary tract infection in critical pediatric patients]. / Infección nosocomial del tracto urinario en niños críticos.

OBJECTIVE: To determine the incidence, etiology and risk factors of nosocomial urinary tract infections (nUTI) in a second level Pediatric Intensive Care Unit (PICU). PATIENTS AND METHODS: A prospective study of 104 patients admitted to the PICU with a length of stay of more than 48 hours was carried out over a one year period (January to December 2009) to study the incidence and risk factors of nUTI. Urine samples were collected and cultured in all patients admitted for more than 48 hours to our PICU. Those needing indwelling urinary catheters had urine samples collected upon admission and every 24 hours until catheter retrieval, while those who did not need catheters had samples collected upon admission and every 48 hours until discharge from the PICU. RESULTS: Six patients (5.8% of those admitted) were diagnosed of nUTI, with an incidence density of 5/1000 patients/day and 12.2/1000 catheterization days. Four of these were caused by E. coli (including a multiresistant strain), and two by C. albicans. Patients suffering nUTIs had significantly more relevant medical antecedents and a longer period of admittance than patients without nUTI. A statistically nonsignificant tendency towards increased infection risk was also found in younger patients and in those who needed an indwelling catheter for longer periods. CONCLUSIONS: We found a higher incidence density of catheter associated nUTI than in other reports. This at least partially could be due to the characteristics of our patients, and to the exhaustive methodology used for detection.

High-fat diets impair spatial learning in the radial-arm maze in mice.

It has been suggested that hyperglycemia and insulin resistance triggered by energy-dense diets can account for hippocampal damage and deficits of cognitive behaviour. We wonder if the impairment of learning and memory processes detected in diet-induced obese (DIO) mice is linked to diet composition itself. With this purpose we have evaluated learning performance in mice undergoing a short-term high-fat (HF) treatment, which leads to a pre-obese state characterized by increased adiposity without significant changes of glucose and insulin plasma levels. C57BL/6J mice were fed either a HF (45 kcal% from fat) or control diet (10 kcal% from fat) during 8 weeks. Learning performance was evaluated by using the four-arm baited version of the eight-arm radial maze test (RAM). Mice were trained to learn the RAM protocol and then memory was tested at different time-points. Time spent to consume food placed in baited arms and errors committed to find them were measured in all sessions. DIO mice significantly spent more time in learning the task and made a greater number of errors than controls. Moreover, retention tests revealed that both working and total memory errors were also more numerous in DIO mice. The current results show that short-term DIO impairs spatial learning and suggest that impairment of hippocampal learning elicited by HF diets might be perceptible before metabolic alterations linked to obesity develop.

A cholecystokinin-1 receptor agonist (CCK-8) mediates increased permeability of brain barriers to leptin.

BACKGROUND AND PURPOSE: Leptin regulates energy expenditure and body weight by acting both on the hypothalamus and on peripheral targets. Central actions of leptin are enhanced by cholecystokinin (CCK). The interaction between leptin and CCK makes physiological sense, as rats lacking CCK1 receptors are resistant to peripheral leptin but not to leptin directly infused into the brain. We have recently reported that CCK enhances leptin effects by increasing the entry of leptin into the CNS. The aim of this work was to further characterize the effect of CCK (10 microg kg(-1)) on leptin kinetics as well as the CCK receptor subtype involved in the interaction between CCK and leptin. EXPERIMENTAL APPROACH: Experiments were carried out both in free-feeding and in fasted rats receiving a single dose of leptin (100 microg kg(-1); i.p.). Parameters analysed over the next 6 h were plasma and cerebrospinal fluid concentrations of leptin. KEY RESULTS: We observed that CCK-8 depressed the increase in plasma leptin that followed the i.p. injection and simultaneously increased leptin concentration in the cerebrospinal fluid from 92+/-25 to 230+/-24 pg mL(-1) (P<0.05). The effect of CCK-8 was totally prevented by the CCK1 receptor antagonist, SR-27,897 (0.3 mg kg(-1), s.c.), but not by the CCK2 receptor antagonist, L-365,260 (1 mg kg(-1)). CONCLUSIONS AND IMPLICATIONS: These results show that CCK plays a role in regulating the access of leptin to the brain and suggest that CCK analogues, acting on CCK1 receptors, might be useful drugs in improving leptin actions within the brain.

Field comparison of passive samplers versus UV-photometric analyser to measure surface ozone in a Mediterranean area.

The aim of the present work is to compare the performance of the Radiello passive sampler versus UV-photometric ozone analyser to measure surface ozone in a Mediterranean Spanish coastal area. The comparison presented considers precision, bias, accuracy, selectivity, detection limit, cost and applicability. For assessing precision, co-located samplers were exposed in duplicate in two reference-sampling sites, beside UV-photometric ozone analyser. Bias was calculated comparing results of passive samplers exposed in three reference-sampling sites and two contrast-sampling sites with the measurements given by the reference analysers. Accuracy was calculated following the EN 482:1994 standard. The limit of detection was calculated as 3 times the standard deviation of the blanks in a batch of passive samplers. The compared Radiello passive samplers give a precision of 5.2%, a bias of 13.8%, an accuracy of 20.5% and a limit of detection of 12.6 microg m(-3). The selectivity and applicability of this methodology is in both aspects successful. Surface ozone levels measured with passive samplers were comparable with the averaged values measured with the reference analyser both in the reference-sampling sites and in the contrast-sampling sites.

eIF5A: uma proteína essencial para a viabilidade celular cuja função permanece obscura / eIF5A: an essential protein for cell viability whose function remains obscure

O provável fator de início de tradução 5A (eIF5A) é uma proteína abundante e altamente conservada em todos os organismos eucarióticos observados e também está presente em arquebactérias. eIF5A é essencial para aviabilidade celular e esse fator é a única proteína descrita que contém o resíduo de aminoácido hipusina. Em Saccharomyces cerevisiae, eIF5A é expressa em condições aeróbicas pelo gene TIF51A. Apesar de eIF5A ser conhecida há quase 30 anos, a sua função biológica ainda é obscura. Este artigo revisa os estudos de caracterização funcional de eIF5A, evidenciando como esse fator foi envolvido com diferentes etapas do metabolismo de RNA mensageiro (mRNA), como o início de tradução, o transporte nucleocitoplasmático e o decaimento de RNA mensageiro. Ainda, estudos que evidenciaram o envolvimento de eIF5A com a proliferação celular e progressão no ciclo celular também foram abordados. Finalmente, esse artigo apresenta os resultados recentes dos experimentos que colocam eIF5A novamente no cenário da tradução. Novos experimentos serão necessários para definir o papel desempenhado por eIF5A na maquinaria de tradução.

[Frontal bone aneurysmal cyst. Case report]. / Quiste óseo aneurismático del hueso frontal. Caso clínico.

Aneurysmal bone cysts are very rare in the calvaria. We are reporting a 23 year old white male with a very large right frontal aneurysmal bone cyst and a large follow-up period. The MRI findings--a multiloculated expansive tumor with fluid levels inside--are almost pathognomonic for this lesion. Radical surgery was curative for this patient.

General practitioners and the Internet--a questionnaire survey of Internet connectivity and use in Lothian.

OBJECTIVE: To determine the extent of Internet connectivity and use by GPs in the Lothian Health Board area and to investigate which Internet medical information resources GPs find most useful for work related purposes. DESIGN: Postal questionnaire. SETTING: General Practice. SUBJECTS: Postal questionnaires were sent to all GPs listed in the Lothian Health Primary Care mailing list. In total 546 questionnaires were sent to 126 practices during April/May 1999. RESULTS: At least one response was received from 86% of practices and overall 56% of questionnaires were returned. Ninety two percent of practices that responded indicated that an Internet connection was available with 86% reporting that access was restricted to one computer. Sixty seven percent of responding GPs indicated that they had used the Internet, with more time being spent using the Web than Email. Of the Internet users 54%, rated the Internet as useful or very useful for work related purposes. Accessibility and immediacy of access to information were among the most useful aspects of Internet use, with locating specific resources and lack of time being highlighted as commonly reported difficulties. Popular medical Internet resources included Medline/Pubmed, the eBMJ/BMA site and a range of other resources produced by authoritative medical bodies. CONCLUSION: This study indicates high Internet connectivity in Lothian general practices, with increased levels of use by GPs compared with previous benchmark studies and high levels of perceived usefulness of the Internet in relation to GPs work. Training and education of GPs is clearly required if they are to take best advantage of improved Internet accessibility.

[Posterior lumbar intersomatic fusion]. / Fusion intersomática lumbar posterior.

Since late 1992 we started performing posterior lumbar interbody fusions together with pedicular screws and intertransverse fusion. Later on we decided to use posterior lumbar interbody fusions with titanium cages and autologous bone. We are presenting our results with a group of 52 patients with 6 months to 4 and a half years of follow-up. We have used the Prolo Functional Economic Outcome Rating Scale to evaluate our results, obtaining a high percentage (92%) of satisfactory results. The fusion's percentage was also very high, although we express the difficulty to evaluate the fusion grade considering the X-ray artifact produced by the cages. We conclude that PLIF with cages it is a surgical procedure with a high rate of success if we establish clearly the clinical criteria for its application and perform correctly the surgical technique.

Selective cytotoxicity of 3-amino-L-tyrosine correlates with peroxidase activity.

In the presence of 3-amino-L-tyrosine (3-AT), abundant brown pigment forms in human HL-60 cells, but not in a variety of other cell lines, which are reported to be lower in mean myeloperoxidase (MPO) content than HL-60. Cells were assessed for peroxidase activity with an ABTS-based colorimetric assay and compared to values obtained with known amounts of human myeloperoxidase. HL-60 cells were estimated to contain the equivalent of 37.1 ng myeloperoxidase/10(6) cells versus 26.1 and 5.0 ng/10(6) cells for human K562 and murine RAW 264.7 cell lines, respectively. HL-60 cells exhibited a nearly 60% inhibition of proliferation and > 70% reduction in cell viability after 4 d of culture in the presence of 100 microg 3-AT per ml. Higher concentrations of 3-AT (up to 400 microg/ml) for 4 d reduced HL-60 proliferation by 80% and decreased viability to 1-3%. Comparable levels of cytotoxicity were achieved in KG-1 cells after 7 d with 200 or 400 microg 3-AT per ml. K562 cells exhibited a 40% reduction in cell number after 7 d with 400 microg 3-AT per ml, but concentrations less than 400 microg/ml did not significantly affect K562 proliferation. K562 viability remained unchanged with doses of 3-AT up to 400 microg/ml. RAW 264.7 cells exhibited unchanged viability and proliferation in the presence of 3-AT at concentrations up to 400 microg 3-AT per ml. K562, KG-1, and RAW 264.7 cells exhibited no evidence of brown pigment formation in the presence of 3-AT and medium containing 10% fetal bovine serum. However, RAW 264.7 cells that were converted to protein-free medium and exposed to 3-AT exhibited intense brown pigment in some cell nuclei. A high percentage of HL-60 cells treated with 3-AT exhibited membrane blebbing, pyknosis, and nuclear fragmentation, which was not observed among other 3-AT-treated cell lines. A mechanism involving toxic intermediates of peroxidase-mediated "aminomelanin" formation is hypothesized.

Mechanism of inhibition of rat liver bilirubin UDP-glucuronosyltransferase by triphenylalkyl derivatives.

A series of potent and competitive inhibitors of UDP-glucuronosyltransferase derived from 7,7,7-triphenylheptanoic acid has been synthesized in order to probe the active site of the isozyme involved in the glucuronidation of the endogenous toxic compound, bilirubin IX alpha. Like triphenylalkylcarboxylic acids, triphenyl alcohols were found to be very effective competitive inhibitors of the reaction (Ki 12 to 180 microM). Superimposition of the best inhibitors with bilirubin by computer modeling showed a marked spatial similarity, which accounts for the observed competitive-type inhibition. The bulky triphenylmethyl moiety of the inhibitor superimposed well on the part of the bilirubin molecule containing three of the four pyrrole rings. In agreement, substitution of the triphenylmethyl moiety by planar structures such as fluorenyl or indenyl rings completely suppressed the inhibition. In addition, the weak inhibition exerted by the shortest carboxylic acids could be related to the higher acidity of these molecules. The inhibition potency depended on the acidity of the molecules; the more acidic, the less inhibitory, suggesting that the presence of a negative charge on the inhibitor molecule prevents bilirubin glucuronidation. Based on these results, a reaction mechanism for bilirubin glucuronidation is postulated.

Arginine 52 and histidine 54 located in a conserved amino-terminal hydrophobic region (LX2-R52-G-H54-X3-V-L) are important amino acids for the functional and structural integrity of the human liver UDP-glucuronosyltransferase UGT1*6.

The hepatic UDP-glucuronosyltransferase UGT1*6 is actively involved in the glucuronidation of short and planar phenols in humans. Based on the irreversible inhibition of the enzyme on chemical modification by 2,3-butanedione and diethyl pyrocarbonate, the roles of His54 and Arg52 were investigated by oligonucleotide site-directed mutagenesis. These amino acids belong to a consensus sequence LX2-R52-G-H54-X3-V-L located in a conserved hydrophobic region of the variable amino-terminal domain of UGT. Arg52 was replaced by alanine (mutant R52A), and His54 was replaced by alanine or glutamine (mutants H54A and H54Q). The immunological and catalytic properties of UGT1*6 and mutants were examined after stable expression in V79 cell lines. Immunoblots and immunoprecipitation studies revealed that the mutant and UGT1*6 proteins were expressed in the microsomal membranes in similar amounts. However, replacement of His54 by glutamine led to a complete loss of activity toward 4-methylumbelliferone, and the Vmax value was decreased 4-5-fold in the mutants R52A and H54A compared with the wild-type enzyme. The dissociation constants that characterize the binding of 4-methylumbelliferone and UDP-glucuronic acid to UGT1*6 were not greatly affected by the mutations. Interestingly, H54Q was not recognized by specific antibodies to the amino-terminal portion of UGT1*6, thereby indicating that this amino acid was critical to antibody recognition. In contrast, the mutants R52A and H54A could not be differentiated from the wild-type protein by pH optimum or thermal denaturation. Furthermore, these mutants were still sensitive to irreversible inhibition by diethyl pyrocarbonate and 2,3-butanedione, with second-order inactivation constant values similar to those obtained for UGT1*6. Altogether, the strict conservation of His54 and Arg52 and the mutational analysis of these residues suggest that these amino acids in the hydrophobic amino-terminal consensus sequence LX2-R52-G-H54-X3-V-L are important for the function and the structure required for optimal catalytic efficiency of UGT1*6.

Monometoxytrityl derivatives of uridine as inhibitors of a human recombinant UDP-glucuronosyltransferase: UGT1*6.

A series of inhibitors of the human liver recombinant UDP-glucuronosyltransferase 1*6 derived from uridine were synthetized as probes of the binding site of the cosubstrate, UDP-glucuronic acid. If triphenylmethanol or uridine alone failed to inhibit the glucuronidation of 4-methylumbelliferone, the trityl derivatives of uridine were found to be very effective inhibitors of the enzyme (Ki 4.4 to 73 microM). The type of inhibition (competitive or mixed) varied with the substitutions on the uracile or on the triphenylmethyl moiety by halogen atoms or methyl groups. Structural features for the binding of the cofactor are postulated.