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We use the new QUIJOTE-MFI wide survey (11, 13, 17, and 19 GHz) to produce spectral energy distributions (SEDs), on an angular scale of 1°, of the supernova remnants (SNRs) CTB 80, Cygnus Loop, HB 21, CTA 1, Tycho, and HB 9. We provide new measurements of the polarized synchrotron radiation in the microwave range. The intensity and polarization SEDs are obtained and modelled by combining QUIJOTE-MFI maps with ancillary data. In intensity, we confirm the curved spectra of CTB 80 and HB 21 with a break frequency νb at 2.0 |$^{+1.2}_{-0.5}$| and 5.0 |$^{+1.2}_{-1.0}$|  GHz, respectively; and spectral indices above the break of |$-0.6^{+0.04}_{-0.05}$| and |$-0.86^{+0.04}_{-0.05}$|⁠. We provide constraints on the Anomalous Microwave Emission, suggesting that it is negligible towards these SNRs. From a simultaneous intensity and polarization fit, we recover synchrotron spectral indices as flat as −0.24, and the whole sample has a mean and scatter of −0.44 ± 0.12. The polarization fractions have a mean and scatter of 6.1 ± 1.9 per cent. When combining our results with the measurements from other QUIJOTE (Q-U-I JOint TEnerife CMB experiment) studies of SNRs, we find that radio spectral indices are flatter for mature SNRs, and particularly flatter for CTB 80 (⁠|$-0.24^{+0.07}_{-0.06}$|⁠) and HB 21 (⁠|$-0.34^{+0.04}_{-0.03}$|⁠). In addition, the evolution of the spectral indices against the SNRs age is modelled with a power-law function, providing an exponent −0.07 ± 0.03 and amplitude −0.49 ± 0.02 (at 10 kyr), which are conservative with respect to previous studies of our Galaxy and the Large Magellanic Cloud. [ABSTRACT FROM AUTHOR]

In tumor biology, hypoxia triggers signaling pathways that induce transcription of genes related to angiogenesis, metastasis, glucose metabolism and apoptosis. We investigated the expression of hypoxia related proteins, galectin-3 (Gal-3) and hypoxia-inducible factor-1α (HIF-1α), in conventional (CA) and unicystic ameloblastomas (UA). We applied immunohistochemistry for Gal-3 and HIF-1α to 72 cases of ameloblastoma: 59 cases of CA and 13 cases of unicystic UA. Immunoexpression was evaluated semiquantitatively. Gal-3 expression was observed in 40% of the cases: 23/59 CA and 6/13 UA. HIF-1α immunostaining was observed in 55% of cases: 36/59 CA and 4/13 UA. 19 CA and 2 UA were positive for both markers. Immunostaining was evident in the center of the tumor islands, which exhibited squamous metaplasia or cystic degeneration. The expression of Gal-3 and HIF-1α in ameloblastomas could be interpreted as a response to hypoxic stress. Co-expression of both proteins in CA may suggest a potential interaction that participates in the biological behavior of this ameloblastoma variant. [ABSTRACT FROM AUTHOR]

Abstract Background The oral administration of vitamin B12 offers a potentially simpler and cheaper alternative to parenteral administration, but its effectiveness has not been definitively demonstrated. The following protocol was designed to compare the effectiveness of orally and intramuscularly administered vitamin B12 in the treatment of patients ≥65 years of age with vitamin B12 deficiency. Methods/design The proposed study involves a controlled, randomised, multicentre, parallel, non-inferiority clinical trial lasting one year, involving 23 primary healthcare centres in the Madrid region (Spain), and patients ≥65 years of age. The minimum number of patients required for the study was calculated as 320 (160 in each arm). Bearing in mind an estimated 8-10% prevalence of vitamin B12 deficiency among the population of this age group, an initial sample of 3556 patients will need to be recruited. Eligible patients will be randomly assigned to one of the two treatment arms. In the intramuscular treatment arm, vitamin B12 will be administered as follows: 1 mg on alternate days in weeks 1 and 2, 1 mg/week in weeks 3–8,and 1 mg/month in weeks 9–52. In the oral arm, the vitamin will be administered as: 1 mg/day in weeks 1–8 and 1 mg/week in weeks 9–52. The main outcome variable to be monitored in both treatment arms is the normalisation of the serum vitamin B12 concentration at weeks 8, 26 and 52; the secondary outcome variables include the serum concentration of vitamin B12 (in pg/ml), adherence to treatment, quality of life (EuroQoL-5D questionnaire), patient 3satisfaction and patient preferences. All statistical tests will be performed with intention to treat and per protocol. Logistic regression with random effects will be used to adjust for prognostic factors. Confounding factors or factors that might alter the effect recorded will be taken into account in analyses. Discussion The results of this study should help establish, taking quality of life into account, whether the oral administration of vitamin B12 is an effective alternative to its intramuscular administration. If this administration route is effective, it should provide a cheaper means of treating vitamin B12 deficiency while inducing fewer adverse effects. Having such an alternative would also allow patient preferences to be taken into consideration at the time of prescribing treatment. Trial registration This trial has been registered with ClinicalTrials.gov, number NCT 01476007, and under EUDRACT number 2010-024129-20.

Background Kidney transplantation (KT) is the replacement therapy of choice in patients with end-stage renal disease (ESRD). Here we show a cohort of kidney transplant recipients from the period of May 1994 to May 2016 in 2 2nd-level private hospitals from the city of Toluca in the state of Mexico. Methods We checked the clinical files of all the patients that received KT in the period of study. Results We report 25 KT: 23 performed in Sanatorio Toluca and 2 in Sanatorio Florencia; 16 (64%) male and 9 (26%) female; mean age 36.03 ± 15.9 years (range, 10–66); 19 (76%) hemodialysis and 9 (24%) continuous ambulatory peritoneal dialysis before KT; ESRD etiology unknown in 16 (64%), diabetes in 5 (20%), IgA nephropathy in 2 (8%), and other in 2 (8%); living donors in 13 (52%) and deceased donors in 12 (48%); blood group 0+ in 18 (72%), A+ in 5 (20%), and B+ in 2 (8%); 21 (84%) with 0 and 4 (16%) with 1 HLA mismatch; and delayed graft function in 8 (32%), of which 7 were from deceased donors and 1 from a living donor. All 25 (100%) had a functional kidney at 1 year of follow-up. Immunosuppression regime consisted of multitarget maintenance therapy in all 25 (100%): cyclosporine in 18 (72%) and tacrolimus in 7 (28%). We used only methylprednisolone (MTP) as induction therapy. There were only 2 cases (8%) of acute rejection during the 1st 6 months of follow-up, and both responded to treatment with MTP. Conclusions KT is the treatment of choice for patients with ESRD. The obtained results using only an MTP induction regime are satisfactory, with graft and patient survivals of 100% in the 1st year of follow-up. [ABSTRACT FROM AUTHOR]

Objective: Analyse the association between the use of diagnostic tests and the characteristics of older patients 65 years of age or more who consult the emergency department (ED)., Methods: We performed an analysis of the EDEN cohort that includes patients who consulted 52 Spanish EDs. The association of age, sex, and ageing characteristics with the use of diagnostic tests (blood tests, electrocardiogram (ECG), microbiological cultures, X-ray, computed tomography, ultrasound, invasive techniques) was studied. The association was analysed by calculating the adjusted odds ratios (aOR) and their 95 % confidence intervals (CI) using a logistic regression model., Results: A total of 25,557 patients were analysed. There was an increase in the use of diagnostic tests based on age, with an aOR for blood test of 1.805 (95 %CI 1.671 - 1.950), ECG 1.793 (95 %CI 1.664 - 1.932) and X-ray 1.707 (95 %CI 1.583 - 1.840) in the group of 85 years or more. The use of diagnostic tests is lower in the female population. Most ageing characteristics (cognitive impairment, previous falls, polypharmacy, dependence, and comorbidity) were independently associated with increased use of diagnostic tests., Conclusions: Age, and the characteristics of ageing itself are generally associated with a greater use of diagnostic tests in the ED., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 College of Emergency Nursing Australasia. Published by Elsevier Ltd. All rights reserved.)

Background: Cleft lip and palate is an anomaly that affects both women and men. It is considered to be among the most frequent congenital abnormalities and is related to modifications in chromosomal DNA and multiple genetic alterations. This anomaly can also be associated with various environmental factors, such as tobacco and alcohol consumption, medication use, and exposure to different environmental and industrial toxic substances. The objective of this study was to document the frequency of risk factors related to cleft lip and palate through a systematic review of Mexican studies., Methods: In this systematic review, a bibliographic search was conducted following PRISMA guidelines in the databases Scielo, ScienceDirect, PubMed, and EBSCO. Keywords related to cleft lip and palate, epidemiology, and risk factors were used. In all, 3 independent reviewers (J.A.S.L., S.L.V., and N.M.F.) selected and evaluated a total of 17 articles included in this analysis, achieving a coefficient of κ = 0.84., Results: The analysis revealed that the highest frequency of conducted studies was in the State of Mexico. The most common risk factors identified were environmental, pharmacological, consumption habits, and gynecological factors., Conclusions: Identifying the main risk factors for cleft lip and palate in the Mexican population will enable the implementation of preventive measures aimed at reducing exposure to these factors. Additionally, early intervention can improve the quality of life for individuals affected by this condition.

Background: Dental fluorosis (DF) is caused by excessive exposure to fluoride during odontogenesis and leads to various changes in the development of tooth enamel. Some regions in Mexico are considered endemic fluorosis zones due to the high fluoride content in drinking water. The objective of this study was to perform a systematic review and meta-analysis to identify the association between the concentration of fluoride in drinking water and the severity of dental fluorosis in northern and western Mexico., Methods: This protocol was registered in the PROSPERO database (ID: CRD42023401519). The search for information was carried out in the PubMed/Medline, Scopus, SpringerLink, and Google Scholar databases between January 2015 and October 2023. The overall relative risk was calculated using the inverse of variance approach with the random effects method. The RoB 2.0 tool was used to construct risk plots., Results: Eleven articles were analyzed qualitatively, and most of the included studies presented at least one level of DF severity; six articles were analyzed quantitatively, dividing them into two regions. In North region it was observed a higher prevalence of severe TF cases, corresponding to ≥ TF 5 category (4.78) [3.55, 6.42]. In the West region, most of the included studies presented a higher prevalence of less severe cases, corresponding to ≤ TF 4, in comparison with the North region (0.01) [0.00, 0.52], interpreted as a protective effect., Conclusion: The concentrations of fluorides in drinking water are reportedly high in these regions and are directly related to the severity of dental fluorosis experienced by the inhabitants. In the Northern region exists a major concentration of fluoride in drinking water compared with the Western region as well as a prevalence of higher severity cases of dental fluorosis., (© 2024. The Author(s).)

Management of patients with hemophilia A (HA) requires the knowledge and experience of specialized health care professionals. However, these patients may need to be attended in emergencies, outside the referral hospital, where health care professionals do not know about hemophilia and/or new innovative treatments. This study aimed to develop a simple and practical algorithm that could be used in emergency situations by nonspecialized treaters in HA and bleeding with or without factor VIII (FVIII) inhibitors under emicizumab prophylaxis. A group of experts agreed on a simple algorithm, easy to operate, adapted from previous international guidelines, and based on their clinical experience. The proposed algorithm starts with identifying the patient, confirming the diagnosis of HA, prophylaxis with emicizumab, and/or use of other treatments. After stabilizing the patient and stratifying the bleeding risk, the patient is managed according to the presence/absence of FVIII inhibitors. Patients without FVIII inhibitors should receive FVIII concentrate. Dose and follow-up depend on bleeding localization and severity. Patients with FVIII inhibitors should preferably receive recombinant activated factor VII as bypass agent. A basic coagulation assay, FVIII assessment, and FVIII inhibitors detection assays are necessary in an emergency. However, these tests should be interpreted with caution and appropriately chosen, as emicizumab may alter the results. The management of patients with HA is challenging in emergency situations, especially if they are treated with new agents. Nonspecialized in coagulopathies health care professionals have limited understanding of the disease, highlighting the need for an algorithm to assist them in making informed decisions., Competing Interests: Conflict of Interest V.J-Y. has received reimbursement for attending symposia/congresses and/or honoraria for speaking and/or honoraria for consulting, and/or funds for research from Takeda, Bayer, BioMarin, CSL-Behring, Grifols, Novo Nordisk, Sobi, Roche, Octapharma, and Pfizer. M.T.Á-R. has received reimbursement for attending symposia/congresses and/or honoraria for speaking and/or honoraria for consulting, and/or funds for research from Takeda, Bayer, CSL-Behring, Novo Nordisk, Sobi, Roche, Grifols, Novartis, Amgen, and Pfizer. R.B.M. has received reimbursement for attending symposia/congresses and/or honoraria for speaking and/or honoraria for consulting, and/or funds for research from Takeda, Bayer, CSL-Behring, Novo Nordisk, Sobi, Roche, Boehringer Ingelheim, and Pfizer. S.B. has received reimbursement for attending symposia/congresses and/or honoraria for speaking and/or honoraria for consulting, and/or funds for research from Takeda, Bayer, CSL-Behring, Novo Nordisk, SOBI, Roche, Biomarin, and Pfizer. J.M.C.V. has received reimbursement for attending symposia/congresses and/or honoraria for speaking and/or honoraria for consulting, and/or funds for research from Takeda, Bayer, CSL-Behring, Novo Nordisk, Sobi, Roche, and Pfizer. R.G.G. has received personal fees from Novo Nordisk. J.R.G.P. has received reimbursement for attending symposia/congresses from Roche, Amgem, Novo Nordisk, and Pfizer, and funds for consulting from Roche. R.J.N.V. has received reimbursement for attending symposia/congresses and/or honoraria for speaking and/or honoraria for consulting, and/or funds for research from Takeda, Octapharma, Bayer, CSL-Behring, Novo Nordisk, Grifols, Sobi, Roche, and Pfizer. M.R.L. has received reimbursement for attending symposia/congresses and/or honoraria for speaking and/or honoraria for consulting, and/or funds for research from Takeda, Octapharma, CSL-Behring, Novo Nordisk, Sobi, Roche, and Pfizer., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. ( https://creativecommons.org/licenses/by/4.0/ ).)

Background: Polypharmacy is a growing phenomenon among elderly individuals. However, there is little information about the frequency of polypharmacy among the elderly population treated in emergency departments (EDs) and its prognostic effect. This study aims to determine the prevalence and short-term prognostic effect of polypharmacy in elderly patients treated in EDs., Methods: A retrospective analysis of the Emergency Department Elderly in Needs (EDEN) project's cohort was performed. This registry included all elderly patients who attended 52 Spanish EDs for any condition. Mild and severe polypharmacy was defined as the use of 5-9 drugs and ⩾10 drugs, respectively. The assessed outcomes were ED revisits, hospital readmissions, and mortality 30 days after discharge. Crude and adjusted logistic regression analyses, including the patient's comorbidities, were performed., Results: A total of 25,557 patients were evaluated [mean age: 78 (IQR: 71-84) years]; 10,534 (41.2%) and 5678 (22.2%) patients presented with mild and severe polypharmacy, respectively. In the adjusted analysis, mild polypharmacy and severe polypharmacy were associated with an increase in ED revisits [odds ratio (OR) 1.13 (95% confidence interval (CI): 1.04-1.23) and 1.38 (95% CI: 1.24-1.51)] and hospital readmissions [OR 1.18 (95% CI: 1.04-1.35) and 1.36 (95% CI: 1.16-1.60)], respectively, compared to non-polypharmacy. Mild and severe polypharmacy were not associated with increased 30-day mortality [OR 1.05 (95% CI: 0.89-2.26) and OR 0.89 (95% CI: 0.72-1.12)], respectively., Conclusion: Polypharmacy was common among the elderly treated in EDs and associated with increased risks of ED revisits and hospital readmissions ⩽30 days but not with an increased risk of 30-day mortality. Patients with polypharmacy had a higher risk of ED revisits and hospital readmissions ⩽30 days after discharge., Competing Interests: The authors declare that there is no conflict of interest., (© The Author(s), 2024.)

Background: The development and establishment of oral squamous cell carcinoma are confined to carcinogenesis, which involves oxidative stress via oxygen-free radical production as a hydroxyl radical (HO•), considered the most important cause of oxidative damage to basic biomolecules since it targets DNA strands. 8-Hydroxy-2´-deoxyguanosine (8-OHdG) is considered a free radical with a promutagenic capacity due to its ability to pair with adenosine instead of cytosine during replication., Material and Methods: We collected 30 paraffin-embedded tissue samples of OSCC from patients treated between 2013 and 2018. We recorded risk habits, disease stage, disease free survival and death with at least 3 years of follow-up. 8-Hydroxyguanosine was evaluated by immunohistochemistry and subsequently classified as weak-moderate or strong positive expression. Additionally, we noted whether it was expressed in the cytoplasm and/or nucleus., Results: Most of the cases expressed 8-OHdG with a strong intensity (80%). All neoplastic cells were preferentially stained in only the cytoplasm (70.0%), but nuclear positivity was found in 30%, independent of the intensity. Based on the location in the cytoplasm and/or nucleus, tumors >4 cm showed a high frequency (95.5%) of 8-OHdG expression in only the cytoplasm, with a significant difference (p value 0.001). Additionally, overall survival was affected when immunoexpression was present in the cytoplasm and nucleus because all deaths were in this group were statistically significant (p value = 0.001)., Conclusions: All tumors showed DNA oxidative damage, and 8-OHdG was preferentially expressed in the cytoplasm. This finding was associated with tumor size and, when present in the nucleus, might also be related to death.

Purpose: To investigate the knowledge, training and clinical practice of Spanish optometrists about preventing and controlling myopia progression., Methods: A web-based questionnaire was distributed to Spanish optometrists through social networks, optometric professional bodies and one of the major Spanish optometrists' associations to assess practitioner perception, understanding, and self-reported clinical practice behavior related to myopia diagnosis and management., Results: A total of 534 optometrists with a mean age of 40.8 ± 10.3 years completed the survey. Most respondents have been practicing optometry for more than 20 years (89.8%), report having actively treated childhood myopia (82.4%), and are very concerned about the increasing frequency of pediatric myopia in their daily practice (85.3%). Almost all of the respondents (97.3%) agreed that the efficacy of treatment is related to the age at which it is prescribed, and more than half (53.6%) considered a progression higher than - 0.50 and up to - 1.00D as the minimum necessary to consider a myopia management option. Respondents who reported actively managing childhood myopia considered orthokeratology, atropine and soft-defocus contact lenses the most effective myopia control interventions. However, the most frequently prescribed form of myopia correction by Spanish optometrists was single-vision spectacles, followed by orthokeratology and soft-defocus contact lenses., Conclusions: Spanish optometrists are very active in the management of myopia, especially by fitting orthokeratology lenses or dual-focus soft contact lenses for myopia control, but there is still potential for improvement in the methodology they follow for both the diagnosis and management of myopia., (© 2023. The Author(s).)

Objectives: To study baseline factors associated with hypo- and hypernatremia in older patients attended in emergency departments (EDs) and explore the association between these dysnatremias and indicators of severity in an emergency., Material and Methods: We included patients attended in 52 Spanish hospital EDs aged 65 years or older during a designated week. All included patients had to have a plasma sodium concentration on record. Patients were distributed in 3 groups according to sodium levels: normal, 135-145 mmol/L; hyponatremia, 135 mmol/L; or hypernatremia > 145 mmol/L. We analyzed associations between sodium concentration and 24 variables (sociodemographic information, measures of comorbidity and baseline functional status, and ongoing treatment for hypo- or hypernatremia). Indicators of the severity in emergencies were need for hospitalization, in-hospital mortality, prolonged ED stay (> 12 hours) in discharged patients, and prolonged hospital stay (> 7 days) in admitted patients. We used restricted cubic spline curves to analyze the associations between sodium concentration and severity indicators, using 140 mmol/L as the reference., Results: A total of 13 368 patients were included. Hyponatremia was diagnosed in 13.5% and hypernatremia in 2.9%. Hyponatremia was associated with age ($ 80 years), hypertension, diabetes mellitus, an active neoplasm, chronic liver disease, dementia, chemotherapy, and needing help to walk. Hypernatremia was associated with needing help to walk and dementia. The percentages of cases with severity indicators were as follows: hospital admission, 40.8%; in-hospital mortality, 4.3%; prolonged ED stay, 15.9%; and prolonged hospital stay, 49.8%. Odds ratios revealed associations between lower sodium concentration cut points in patients with hyponatremia and increasing need for hospitalization (130 mmol/L, 2.24 [IC 95%, 2.00-2.52]; 120 mmol/L, 4.13 [3.08-5.56]; and 110 mmol/L, 7.61 [4.53-12.8]); risk for in-hospital death (130 mmol/L, 3.07 [2.40-3.92]; 120 mmol/L, 6.34 [4.22- 9.53]; and 110 mmol/L, 13.1 [6.53-26.3]); and risk for prolonged ED stay (130 mmol/L, 1.59 [1.30-1.95]; 120 mmol/L, 2.77 [1.69-4.56]; and 110 mmol/L, 4.83 [2.03-11.5]). Higher sodium levels in patients with hypernatremia were associated with increasing need for hospitalization (150 mmol/L, 1.94 [1.61-2.34]; 160 mmol/L, 4.45 [2.88-6.87]; 170 mmol/L, 10.2 [5.1-20.3]; and 180 mmol/L, 23.3 [9.03-60.3]); risk for in-hospital death (150 mmol/L, 2.77 [2.16-3.55]; 160 mmol/L, 6.33 [4.11-9.75]; 170 mmol/L, 14.5 [7.45-28.1]; and 180 mmol/L, 33.1 [13.3-82.3]); and risk for prolonged ED stay (150 mmol/L, 2.03 [1.48-2.79]; 160 mmol/L, 4.23 [2.03-8.84]; 170 mmol/L, 8.83 [2.74-28.4]; and 180 mmol/L, 18.4 [3.69-91.7]). We found no association between either type of dysnatremia and prolonged hospital stay., Conclusion: Measurement of sodium plasma concentration in older patients in the ED can identify hypo- and hypernatremia, which are associated with higher risk for hospitalization, death, and prolonged ED stays regardless of the condition that gave rise to the dysnatremia.

Objective: The aim of this study was to investigate and compare the immunohistochemical expression of connexin 43 (Cx43) in tooth germs (TGs), ameloblastic fibromas (AFs), ameloblastic fibro-odontomas (AFOs), and conventional ameloblastomas (AMs)., Study Design: Nine TGs, 12 AFs, 12 AFOs, and 27 AMs were evaluated for Cx43 expression by immunohistochemistry., Results: Most of the TGs expressed Cx43 in the mesenchyme (77.6%) and in the late stages of odontogenesis. Cx43 was more highly expressed (P < .05) in the mesenchymal layer of all groups than in the epithelial layer except for the AFOs. When comparing the expression of Cx43 in the different layers of the analyzed groups, statistically significant differences were observed between AFO vs AM (*P = .0158) in the epithelial layer and between AF vs AFO (P** = .0046) in the mesenchymal layer., Conclusions: The results obtained in this study showed that Cx43 is a protein with important expression in the mesenchymal layer of the embryonic and odontogenic tissues studied. It could be speculated that Cx43 participates in mineralization events based on the relationship of the expression of this protein between the epithelial and mesenchymal layers of odontogenic tissues., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The intake of high concentrations of fluoride, mainly through drinking water, diet and fluoridated dentifrices, produces fluorosis, which in its early stages is manifested as dental fluorosis (DF). To recognize exposure to fluoride in endemic areas and to evaluate the risk of developing health impairment, the WHO has established several biomarkers that are used to determine systemic fluorine (F - ) exposure. Thus, the aim of this study was to conduct a systematic review and meta-analysis of the relationship between the severity of DF and fluoride biomarkers in endemic areas. The protocol of this study was previously registered as CRD42021244974. A digital search was carried out in PubMed/Medline, SpringerLink, Scopus, Cochrane and Google Scholar by employing the keywords "urine", "nails", "hair", "plasma", "saliva" and "dental fluorosis" for the original studies with content associated with F - for the biomarkers and DF. The mean difference was established as the effect measure for the meta-analysis. Seven studies fulfilled the eligibility criteria, among which five assessed urine and two employed nails as fluoride biomarkers. A positive significant difference was found between the biomarkers and the severity of DF (0.27, p < 0.001) and individually for each biomarker (urine: 0.14, p = 0.001; nails: 0.88, p < 0.05). The F - concentration in urine and nails is correlated with the severity of DF, with the most evident differences between healthy individuals and those with mild severity. Both biomarkers are adequate to assess this relationship in endemic areas of fluoride and DF., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people worldwide. Public health strategies to reduce viral transmission are based on widespread diagnostic testing to detect and isolate contagious patients. Several reverse transcription (RT)-PCR tests, along with other SARS-CoV-2 diagnostic assays, are available to attempt to cover the global demand. Loop-mediated isothermal amplification (LAMP) based methods have been established as rapid, accurate, point of care diagnostic tests for viral infections; hence, they represent an excellent alternative for SARS-CoV-2 detection. The aim of this study was to develop and describe molecular detection systems for SARS-CoV-2 based on RT-LAMP. Recombinant DNA polymerase from Bacillus stearothermophilus and thermostable engineered reverse transcriptase from Moloney Murine Leukemia Virus were expressed using a prokaryotic system and purified by fast protein liquid chromatography. These enzymes were used to set up fluorometric real time and colorimetric end-point RT-LAMP assays. Several reaction conditions were optimized such as reaction temperature, Tris-HCl concentration, and pH of the diagnostic tests. The key enzymes for RT-LAMP were purified and their enzymatic activity was determined. Standardized reaction conditions for both RT-LAMP assays were 65°C and a Tris-HCl-free buffer at pH 8.8. Colorimetric end-point RT-LAMP assay was successfully used for viral detection from clinical saliva samples with 100% sensitivity and 100% specificity compared to the results obtained by RT-qPCR based diagnostic protocols with Ct values until 30. The developed RT-LAMP diagnostic tests based on purified recombinant enzymes allowed a sensitive and specific detection of the nucleocapsid gene of SARS-CoV-2., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: The detection using RT-LAMP was registered by Centro de Investigación y de Estudios Avanzados (CINVESTAV) to be protected as a patent. Biopure® is a registered trademark of CINVESTAV. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2023 Tapia-Sidas et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)