Involvement of autologous myeloid dendritic cells in the evaluation of immediate hypersensitivity reactions to betalactams.

BACKGROUND: Amoxicillin (AX) and clavulanic acid (CLV) are the betalactam antibiotics (BLs) most used to treat bacterial infections, although they can trigger immediate hypersensitivity reactions (IDHRs). The maturation analysis of monocyte-derived dendritic cells (moDCs) and their capacity to induce proliferative response of lymphocytes are useful to test the sensitisation to a drug, although without optimal sensitivity. Nevertheless, this can be improved using directly isolated DCs such as myeloid DCs (mDCs). METHODS: mDCs and moDCs were obtained from 28 allergic patients (AP), 14 to AX, 14 to CLV and from 10 healthy controls (HC). The expression of CCR7, CD40, CD80, CD83, and CD86 was analysed after stimulation with both BLs. We measured the capacity of these pre-primed DCs to induce drug-specific activation of different lymphocyte subpopulations, CD3+, CD4+, CD8+, CD4+Th1, and CD4+Th2, by flow cytometry. RESULTS: Higher expression of CCR7, CD40, CD80, CD83, and CD86 was observed on mDCs compared to moDCs from AP after stimulating with the culprit BL. Similarly, mDCs induced higher proliferative response, mainly of CD4+Th2 cells, compared to moDCs, reaching up to 67% of positive results with AX, whereas of only 25% with CLV. CONCLUSIONS: mDCs from selective AP efficiently recognise the culprit drug which trigger the IDHR. mDCs also trigger proliferation of lymphocytes, mainly those with a Th2 cytokine pattern, although these responses depend on the nature of the drug, mimicking the patient's reaction.

The Non-Dereliction in Evolution: Trophic Specialisation Drives Convergence in the Radiation of Red Devil Spiders (Araneae: Dysderidae) in the Canary Islands.

Natural selection plays a key role in deterministic evolution, as clearly illustrated by the multiple cases of repeated evolution of ecomorphological characters observed in adaptive radiations. Unlike most spiders, Dysdera species display a high variability of cheliceral morphologies, which has been suggested to reflect different levels of specialization to feed on isopods. In this study, we integrate geometric morphometrics and experimental trials with a fully resolved phylogeny of the highly diverse endemic species from the Canary Islands to 1) quantitatively delimit the different cheliceral morphotypes present in the archipelago, 2) test their association with trophic specialization, as reported for continental species, 3) reconstruct the evolution of these ecomorphs throughout the diversification of the group, 4) test the hypothesis of convergent evolution of the different morphotypes, and 5) examine whether specialization constitutes a case of evolutionary irreversibility in this group. We show the existence of 9 cheliceral morphotypes and uncovered their significance for trophic ecology. Further, we demonstrate that similar ecomorphs evolved multiple times in the archipelago, providing a novel study system to explain how convergent evolution and irreversibility due to specialization may be combined to shape phenotypic diversification in adaptive radiations.

Structural Model of Suicidal Ideation and Behavior: Mediating Effect of Impulsivity.

The present study aimed to establish the associations between hopelessness, depression and impulsivity with respect to suicidal ideation and behavior, and to explore the role that impulsivity plays in the mechanism that operates between depression and hopelessness. Through an empirical observational study, with an analytical scope based on a cross-sectional design for a sample of 228 university students and using The Inventory of Suicide Orientation (ISO-30); Beck Depression Inventory (BDI); Beck Hopelessness Scale (BHS); and Barratt Impulsiveness Scale (BIS-11). The results indicated a significant positives correlations between BDI, BHS, BIS and ISO-30. Regression analysis showed that depression, impulsivity and hopelessness explain between 57% and 67% of the variance in the risk of suicidal ideation and behavior. Through the analysis of structural equation modeling, three models were established showing that impulsivity mediates the relationship between depressive symptomatology and suicidal ideation and behavior. This study has implications for mental health intervention and research, in that it emphasizes the importance of impulsivity traits as factors that act as triggers in the association between the presence of depressive symptoms and suicidal behavior.

Dopamine oxidation at gold electrodes: mechanism and kinetics near neutral pH.

The two-electron electrochemical oxidation of dopamine is studied voltammetrically at gold macroelectrodes around neutral pH with simulations used to give kinetic and mechanistic data. In particular, the system shows "potential inversion" in which the thermodynamic oxidation potential of dopamine to form the corresponding semi-quinone formation occurs at a more positive potential than that of the oxidation of the semi-quinone to the quinone form. The use of Tafel slopes measured from the voltammograms as a function of the voltage scan rate is show to be a particularly sensitive indicator of mechanism showing the effect of the follow-up chemistry in which the two-electron oxidation product undergoes an irreversible cyclization reaction.

Highly realistic simulation for robot-assisted hypothalamic hamartoma real-time MRI-guided laser interstitial thermal therapy (LITT).

PURPOSE: Real-time MRI-guided laser interstitial thermal therapy (LITT) is a challenging procedure due to its technical complexity, as well as the need for efficient multidisciplinary teamwork and transfer of an anesthetized patient between operating room (OR) and magnetic resonance (MR). A highly realistic simulation was developed to design the safest process before being applied to real patients. In this report, authors address the description of the methodology used for this simulation and its purposefulness. METHODS: The entire image planning, anesthetic, and surgical process were performed on a modified pediatric simulation mannequin with a brain made of medical grade silicone including a hypothalamic hamartoma. Preoperative CT and MR were acquired. Stereotactic insertion of the optical fiber was assisted by the Neuromate® stereotactic robot. Laser ablation was performed with the Medtronic Visualase® MRI-guided system in a 3T Phillips Ingenia® MR scanner. All the stages of the process, participants, and equipment were the same as planned for a real surgery. RESULTS: No critical errors were found in the process design that prevented the procedure from being performed with adequate safety. Specific proposals for team positioning and interaction in patient transfers and in MR room were validated. Some specific elements that could improve safety were identified. CONCLUSION: Highly realistic simulation has been an extremely useful tool for safely planning LITT, because professionals were able to take actions in the workflow based not on ideas but on lived experiences. It contributed definitively to build a well-coordinated surgical team that worked safely and more efficiently.

High-sensitivity troponin T in asymptomatic severe aortic stenosis.

Background: In asymptomatic severe aortic stenosis (ASAS), treatment decisions are made on an individual basis, and case management presents a clinical conundrum. Methods: We prospectively phenotyped consecutive patients with ASAS using echocardiography, exercise echocardiography, cardiac MRI and biomarkers (NT-proBNP, high-sensitivity troponin T (hs-TnT) and ST2) (n = 58). The primary endpoint was a composite of cardiovascular death, new-onset symptoms, cardiac hospitalization, guideline-driven indication for valve replacement and cardiovascular death at 12 months. Results: During the first year, 46.6% patients met primary endpoint. In multivariable analysis, aortic regurgitation ≥2 (p = 0.01) and hs-TnT (p = 0.007) were the only independent predictors of the primary endpoint. The best cutoff value was identified as hs-TnT >10ng/L, which was associated with a ∼10-fold greater risk of the primary endpoint (HR, 9.62; 95% CI, 2.27-40.8; p = 0.002). A baseline predictive model including age, sex and variables showing p < 0.10 in univariable analyses showed an area under the curve (AUC) of 0.79(0.66-0.91). Incorporation of hs-TnT into this model increased the AUC to 0.90(0.81-0.98) (p = 0.03). Patient reclassification with the model including hs-TnT yielded an NRI of 1.28(0.46-1.78), corresponding to 43% adequately reclassified patients. Conclusions: In patients with ASAS, hs-TnT >10ng/L was associated with high risk of events within 12 months. Including hs-TnT in routine ASAS management markedly improved prediction metrics.

Corticosteroids in Patients Hospitalized With Community-Acquired Pneumonia: Systematic Review and Individual Patient Data Metaanalysis.

Background: Our aim was to evaluate the benefits and harms of adjunctive corticosteroids in adults hospitalized with community-acquired pneumonia (CAP) using individual patient data from randomized, placebo-controlled trials and to explore subgroup differences. Methods: We systematically searched Medline, Embase, Cochrane Central, and trial registers (all through July 2017). Data from 1506 individual patients in 6 trials were analyzed using uniform outcome definitions. We investigated prespecified effect modifiers using multivariable hierarchical regression, adjusting for pneumonia severity, age, and clustering effects. Results: Within 30 days of randomization, 37 of 748 patients (5.0%) assigned to corticosteroids and 45 of 758 patients (5.9%) assigned to placebo died (adjusted odds ratio [aOR], 0.75; 95% confidence interval [CI], .46 to 1.21; P = .24). Time to clinical stability and length of hospital stay were reduced by approximately 1 day with corticosteroids (-1.03 days; 95% CI, -1.62 to -.43; P = .001 and -1.15 days; 95% CI, -1.75 to -.55; P < .001, respectively). More patients with corticosteroids had hyperglycemia (160 [22.1%] vs 88 [12.0%]; aOR, 2.15; 95% CI, 1.60 to 2.90; P < .001) and CAP-related rehospitalization (33 [5.0%] vs 18 [2.7%]; aOR, 1.85; 95% CI, 1.03 to 3.32; P = .04). We did not find significant effect modification by CAP severity or degree of inflammation. Conclusions: Adjunct corticosteroids for patients hospitalized with CAP reduce time to clinical stability and length of hospital stay by approximately 1 day without a significant effect on overall mortality but with an increased risk for CAP-related rehospitalization and hyperglycemia.

Impact of COVID-19 on diabetes care: mixed methods study in an Indigenous area of Guatemala.

INTRODUCTION: SARS-CoV-2 has impacted globally the care of chronic diseases. However, direct evidence from certain vulnerable communities, such as Indigenous communities in Latin America, is missing. We use observational data from a health district that primarily serves people of Maya K'iche' ethnicity to examine the care of type 2 diabetes in Guatemala during the pandemic. METHODS: We used a parallel convergent mixed methods design. Quantitative data (n=142 individuals with diabetes) included glycated haemoglobin (HbA1c), blood pressure, body mass index and questionnaires on diabetes knowledge, self-care and diabetes distress. Quantitative data was collected at two points, at baseline and after COVID restrictions were lifted. For quantitative outcomes, we constructed multilevel mixed effects models with multiple imputation for missing data. Qualitative data included interviews with providers, supervisors and individuals living with diabetes (n=20). We conducted thematic framework analysis using an inductive approach. RESULTS: Quantitative data was collected between June 2019 and February 2021, with a median of 487 days between data collection points. HbA1c worsened +0.54% (95% CI, 0.14 to 0.94) and knowledge about diabetes decreased -3.54 points (95% CI, -4.56 to -2.51). Qualitatively, the most important impact of the pandemic was interruption of the regular timing of home visits and peer group meetings which were the standard of care. CONCLUSIONS: The deterioration of diabetes care was primarily attributed to the loss of regular contact with healthcare workers. The results emphasize the vulnerability of rural and Indigenous populations in Latin America to the suspension of chronic disease care.

Neovagina in Mayer-Rokitansky-Küster-Hauser (MRKH) Syndrome: Vaginoplasty Using Ileal Flap.

INTRODUCTION: Surgical treatment of patients with malformations of the female genital tract is a complex problem and there are different techniques described in the literature. The goal of all these techniques is the reconstruction of a neovagina that is anatomically similar to a vagina, with adequate length to facilitate sexual functioning and with the lowest risk of possible complications. The aim of this study is to describe the surgical technique for the reconstruction of a neovagina from an ileal segment without a vascular pedicle. MATERIAL AND METHODS: Description of a surgical technique developed in our tertiary university center in a patient with Mayer-Rokitansky-Küster-Hauser syndrome. RESULTS: The vaginoplasty surgery using ileal flap was performed in three steps. In the first part of the intervention a laparoscopic hysterectomy with bilateral salpingectomy was performed. The second step consisted of isolating the ileal segment, ileal anastomosis and preparing the ileal segment. After the isolated segment was prepared, it was repositioned in a vagina mold to configure the neovagina. Finally, the third step included the adaptation of the vaginal mold with the ileal mucosa to the vesicorectal space. CONCLUSION: Ileal vaginoplasty without a vascular pedicle is an option that can be used to reconstruct the vagina, because it provides an excellent tissue for vaginal replacement. This technique can be used in patients with genital malformations of the genital tract with absence or vaginal hypoplasia.

Social Cognition and Prosocial Behavior in Children with Attention Deficit Hyperactivity Disorder: A Systematic Review.

The purpose of this research is to analyze the empirical evidence on the relationship between social cognition and prosocial behavior in children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD). A systematic review was carried out following the PRISMA guidelines of empirical studies found in PubMed and Scopus databases, including a total of 51 research studies. The results indicate that children and adolescents with ADHD have deficits in social cognition and prosocial behavior. For children with ADHD, their deficits in social cognition highlight their difficulty in the process of theory of mind, emotional self-regulation, emotion recognition and empathy, affecting prosocial behavior, evidencing difficulty in personal relationships, and the creation of emotional bonds with their peers.

Validation of an Ultraviolet Light Response Gene Signature for Predicting Prognosis in Patients with Uveal Melanoma.

Uveal melanoma (UVM) is a highly aggressive ocular cancer with limited therapeutic options and poor prognosis particularly for patients with liver metastasis. As such, the identification of new prognostic biomarkers is critical for developing effective treatment strategies. In this study, we aimed to investigate the potential of an ultraviolet light response gene signature to predict the prognosis of UVM patients. Our approach involved the development of a prognostic model based on genes associated with the cellular response to UV light. By employing this model, we generated risk scores to stratify patients into high- and low-risk groups. Furthermore, we conducted differential expression analysis between these two groups and explored the estimation of immune infiltration. To validate our findings, we applied our methodology to an independent UVM cohort. Through our study, we introduced a novel survival prediction tool and shed light on the underlying cellular processes within UVM tumors, emphasizing the involvement of immune subsets in tumor progression.

Levator ani muscle avulsion in patients with pelvic floor dysfunction - Does it help in understanding pelvic organ prolapse?

INTRODUCTION: Levator ani muscle (LAM) lesions are an important factor in the development of female pelvic organ prolapse (POP). OBJECTIVE: To determine the prevalence of LAM avulsion by transperineal ultrasound. The second outcome is to evaluate the association between complete avulsion and the type, degree, and number of POP compartments involved. MATERIALS AND METHODS: This was a retrospective cohort study performed in a tertiary hospital that included patients with pelvic floor dysfunction evaluated from January 2016 to March 2020. The presence of LAM avulsion was diagnosed by 3D/4D pelvic floor transperineal ultrasound. We identified women with POP, and they were classified according to the POP-Q system. The association between complete avulsion and the type, degree and number of compartments were calculated using generalized logit models. RESULTS: 848 women were included in the analysis. A complete LAM avulsion was found in 195 patients (23 %). Patients with complete avulsion were 4.7 (CI: 1.98-11.5) times more likely to have POP than patients with partial avulsion. The anterior compartment was the most frequently affected (n = 605, 25.8 %). Women with severe stage POP were 3.13 times (CI: 1.90-5.16) more likely to have bilateral complete LAM avulsion than women with mild prolapse. Patients with three-compartment POP were 2.75 times (CI: 1.53-4.94) more likely to have unilateral complete LAM avulsion than women with POP in one compartment. CONCLUSION: The prevalence of LAM avulsion is high in patients with urogynecological symptoms. Patients with complete LAM avulsion are at greater risk of developing POP and have a more advanced stage of prolapse and involvement of multiple compartments.

Effect of corticosteroids on the clinical course of community-acquired pneumonia: a randomized controlled trial.

INTRODUCTION: The benefit of corticosteroids as adjunctive treatment in patients with severe community-acquired pneumonia (CAP) requiring hospital admission remains unclear. This study aimed to evaluate the impact of corticosteroid treatment on outcomes in patients with CAP. METHODS: This was a prospective, double-blind and randomized study. All patients received treatment with ceftriaxone plus levofloxacin and methyl-prednisolone (MPDN) administered randomly and blindly as an initial bolus, followed by a tapering regimen, or placebo. RESULTS: Of the 56 patients included in the study, 28 (50%) were treated with concomitant corticosteroids. Patients included in the MPDN group show a more favourable evolution of the pO2/FiO2 ratio and faster decrease of fever, as well as greater radiological improvement at seven days. The time to resolution of morbidity was also significantly shorter in this group. Six patients met the criteria for mechanical ventilation (MV): five in the placebo group (22.7%) and one in the MPDN group (4.3%). The duration of MV was 13 days (interquartile range 7 to 26 days) for the placebo group and three days for the only case in the MPDN group. The differences did not reach statistical significance. Interleukin (IL)-6 and C-reactive protein (CRP) showed a significantly quicker decrease after 24 h of treatment among patients treated with MPDN. No differences in mortality were found among groups. CONCLUSIONS: MPDN treatment, in combination with antibiotics, improves respiratory failure and accelerates the timing of clinical resolution of severe CAP needing hospital admission. TRIAL REGISTRATION: International Standard Randomized Controlled Trials Register, ISRCTN22426306.

A new ferrous diflunisal complex and its effects on biopools of labile iron.

Drugs bearing metal-coordinating moieties can alter biological metal distribution. In this work, a complex between iron(II) and diflunisal was prepared in the solid state, exhibiting the following composition: [Fe(diflunisal)2(H2O)2], (Fe(dif)2). The ability of diflunisal to alter labile pools of both plasmatic and cellular iron was investigated in this work. We found out that diflunisal does not increase the levels of redox-active iron in plasma of iron overloaded patients. However, diflunisal efficiently carries iron into HeLa or HepG2 cells, inducing an iron-catalyzed oxidative stress.

Protein Z levels and anti-protein Z antibodies in patients with arterial and venous thrombosis.

INTRODUCTION: The thrombotic risk associated with protein Z (PZ) deficiency is unclear. Anti-protein Z (anti-PZ) has been described as a risk factor in unexplained embryo demise. The aim of our study was to evaluate a possible PZ deficiency and presence of anti-PZ antibodies on thrombotic diseases. MATERIAL AND METHODS: We performed a case-control study on 114 patients with preexisting arterial or venous thrombosis (50 and 64, respectively). Thrombosis was studied based on etiology (creating factor risk subgroups) and on specific thrombotic disease. RESULTS: PZ levels of patients were significantly lower compared to controls (1709+-761.3 ng/mL vs. 2437+-964.7 ng/mL P=0.001). The high arterial risk factor subgroup showed the lowest PZ level (1267.5+-609 ng/mL) whereas the rest of arterial and venous etiological subgroups presented similar PZ levels. Patients with peripheral artery disease had the lowest PZ level (1022+-966 ng/mL). The rest of arterial and venous thrombotic diseases presented similar PZ levels. A significant increased risk for arterial and venous thrombosis for the lowest (<1685 ng/mL) quartile of PZ has been founded (OR:52, P=0.001 and OR:18, P=0.007, respectively). Anti-PZ antibodies were negative in the majority of patients, although mean anti-PZ IgG antibody levels in the arterial thrombosis group were significantly higher compared to venous thrombosis and control groups (P=0.05 and P=0.005, respectively). CONCLUSIONS: The results suggest that both arterial and venous thrombotic events are related to low PZ levels and that low PZ concentrations are associated with thrombosis in our study. In arterial thrombosis our findings strengthen previous studies that related low PZ levels to atherosclerotic disease. Anti-PZ antibodies do not seem to play a potent role in thrombosis.

Ultrasound-guided supraclavicular vs infraclavicular brachial plexus blocks in children.

BACKGROUND: Supraclavicular brachial plexus blocks are not common in children because of risk of pneumothorax. However, infraclavicular brachial plexus blocks have been described in paediatric patients both with nerve stimulation and ultrasound (US)-guidance. US-guidance reduces the risk of complications in supraclavicular brachial plexus blocks in adults. OBJECTIVE: To compare the success rate, complications and time of performance of US-guided supraclavicular vs infraclavicular brachial plexus blocks in children. MATERIAL AND METHODS: Eighty children, 5-15 years old, scheduled for upper limb surgery were divided into two randomized groups: group S (supraclavicular), n = 40, and group I (infraclavicular), n = 40. All blocks performed were exclusively US-guided, by a senior anaesthesiologist with at least 6 months of experience in US-guided blocks. For supraclavicular blocks the probe was placed in coronal-oblique-plane in the supraclavicular fossa and the puncture was in-plane (IP) from lateral to medial. For infraclavicular blocks the probe was placed parallel and below the clavicle and the puncture was out-of-plane. Ropivacaine 0.5% was administered up to a maximum of 0.5 ml x kg(-1) until appropriate US-guided-spread was achieved. Block duration and volumes of ropivacaine used (mean+/-1SD) in the supraclavicular approach were recorded. Success rate (mean +/- 1 SD, 95%confidence interval), complications rate and time to perform the block (two-tailed Student's test) were recorded both for supraclavicular and infraclavicular approaches. RESULTS: In the US-guided supraclavicular brachial plexus blocks, the duration of the sensory block was 6.5 +/- 2 h and of the motor block was 4 +/- 1 h. The volume of ropivacaine used in this group was 6 +/- 2 ml. In group I, 88% of blocks achieved surgical anaesthesia without any supplemental analgesia compared with 95% in group S (P = 0.39; difference=7%; 95% CI: -10% to 24%). Failures in group I were because of arterial puncture and insufficient ulnar or radial sensory block. Failures in group S were because of insufficient ulnar sensory block. No pneumothorax or Horner's syndrome was recorded in either group. The mean time (SD) to perform the block was in group I: 13 min (range 5-16) and in group S: 9 min (range 7-12); the 95% CI for this difference was 2-6 min and was statistically significant (P < 0.05). CONCLUSIONS: (i) Ultrasound-guided supraclavicular and infraclavicular brachial plexus blocks are effective in children. (ii) There has been no pneumothorax in 40 US-guided supraclavicular brachial plexus blocks performed by anaesthesiologists already trained in US-guided regional anaesthesia using an IP technique in children > or =5 years old. (iii) In this study, the supraclavicular approach of the brachial plexus was faster to perform than the infraclavicular one.

Association between environmental factors and hospitalisations for bronchiectasis in Badalona, Barcelona, Spain (2007-2015). / Asociación entre factores ambientales e ingresos por bronquiectasias en Badalona, Barcelona (2007-2015).

INTRODUCTION: The relationship between environmental factors and the exacerbation of respiratory diseases has been widely studied. However, there are no studies examining the relationship between these factors and bronchiectasis exacerbations. Our objective was to analyse the association between various environmental factors and hospitalisation for bronchiectasis. MATERIAL AND METHODS: This was a retrospective observational study conducted at two hospitals in Badalona (Barcelona). The number of hospital admissions for exacerbation of bronchiectasis between 2007 and 2015 was obtained. Through multiple regression we analysed the relationship between the number of exacerbations and mean monthly values of temperature, SO2, NO, NO2, O3 and CO. RESULTS: Temperature, SO2, NO, NO2, O3 and CO were significantly associated with an increase in admissions due to exacerbation of bronchiectasis. By controlling the effect of temperature on the pollution variables, only SO2 maintained statistical significance (P=.008). CONCLUSION: We have detected an increase in hospital admissions for exacerbation of bronchiectasis with increases in the atmospheric concentration of SO2 and the decrease in temperature. Prospective studies with different geographical locations to confirm these results are needed.

Intravenous Remifentanil Analgaesia for an Obstetric Patient with Type I Neurofibromatosis and a Factor V Leiden Mutation.

Type I neurofibromatosis is characterised by altered skin pigmentation and the growth of benign tumours, particularly along the peripheral nerves and central nervous system. We report a 36-year-old primigravida woman in labour who was admitted to the obstetric suite of the Hospital Sant Joan de Déu, Barcelona, Spain, in 2007 with hypothyroidism, type I neurofibromatosis and a factor V Leiden mutation. Due to a lack of cranial and spinal imaging data, an epidural was not indicated; instead, continuous intravenous remifentanil analgaesia was administered. The remifentanil infusion was self-titrated by the patient using a visual analogue scale, with the dosage ranging from 0.01 to 0.25 µg/kg/minute. Due to rotational dystocia, Kjelland-type forceps were used during the delivery. After birth, the infant was found to have Apgar scores of 9 and 10, with no maternal or neonatal adverse effects observed. Although still controversial, remifentanil may be a successful alternative for analgaesia in similar cases; however, the specific risks and benefits for each patient should be considered prior to administration.

Desferrioxamine and desferrioxamine-caffeine as carriers of aluminum and gallium to microbes via the Trojan Horse Effect.

Iron acquisition by bacteria and fungi involves in several cases the promiscuous usage of siderophores. Thus, antibiotic resistance from these microorganisms can be circumvented through a strategy of loading toxic metals into siderophores (Trojan Horse Effect). Desferrioxamine (dfo) and its cell-permeant derivative desferrioxamine-caffeine (dfcaf) were complexed with aluminum or gallium for this purpose. The complexes Me(dfo) and Me(dfcaf) (Me=Al3+ and Ga3+) were synthesized and characterized by mass spectroscopy and cyclic voltammetry. Their relative stabilities were studied through competitive equilibria with fluorescent probes calcein, fluorescein-desferrioxamine and 8-hydroxyquinoline. Me(dfo) and Me(dfcaf) were consistently more toxic than free Me3+ against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans, demonstrating the Trojan Horse Effect. Wide spectrum antimicrobial action can be obtained by loading non-essential or toxic metal ions to microbes via a convenient siderophore carrier.

DNA damage in a solution containing copper(II) ions and ascorbic acid: Effect of the presence of sulfite

Some antioxidant compounds have a pro-oxidant effect in the presence of transition metal ions, due to the reduction of Mn+ to M(n-1)+ with simultaneous formation of free radicals, which then promote DNA damage. In the present study, we evaluated the pUC19 DNA damage in a solution containing Cu(II) and ascorbic acid (AA) or S(IV) saturated with air by agarose gel electrophoresis. Our results showed that this damage decreases if AA and S(IV) are simultaneously added. This study also illustrates the importance of Cu(II) in this process, as no DNA damage was observed when AA or S(IV) were present in the absence of this metallic ion. Our data showed that DNA preservation depends on the concentration of AA and S(IV) and occurs when the [S(IV)]:[AA] ratio ranges from 1:1 to 20:1. Absorbance measurements and thermodynamic data show that no reaction occurs between AA and S(IV) when this mixture (pH 5.5) is added to pUC-19 DNA. The presence of dissolved oxygen may be the cause of AA consumption in the mixture of these two antioxidants, which subsequently decreases DNA damage.