IgG-cleavage protein allows therapeutic AAV gene delivery in passively immunized MPS IIIA mice.

The widespread pre-existing αAAV-Abs in humans pose a critical challenge in translation of AAV gene therapy. The IgG degrading enzyme of Streptococci (IdeS) is demonstrated to specifically cleave IgG of humans and other species (not mouse). This study developed a modified new modified IdeS protein product (IdeSop). When incubated in vitro, IdeSop was shown to completely cleave human and rabbit IgGs within 6 h. To test IdeSop in a disease setting, we established a rabbitized αAAV9-Ab+ mouse by an IV infusion of purified acute αAAV9-Ab+ rabbit IgG into MPS IIIA mice, resulting in serum αAAV9-IgG at 1:6,400 and αAAV9-nAbs at 1:800. IdeSop-Ab-cleavage was shown to be dose-dependent. An IV IdeSop infusion at the effective doses resulted in rapid IgG depletion and clearance of pre-existing αAAV9-IgG and αAAV9-nAbs in rabbitized αAAV9-Abs+ MPS IIIA mice. Importantly, an IV injection of a high dose AAV9-hSGSHop vector (5 × 1013vg/kg) at 24 h post IdeSop treatment led to transduction as effective in αAAV9-Abs+ MPS IIIA mice, as in αAAV9-Abs-negative controls. We believe that transient IdeSop administration may offer a great tool to address the pre-existing-αAAV-Abs for the translation of rAAV gene therapy to treat diseases in humans, making effective rAAV gene therapy available to all patients in need.

Methyl Aminolaevulinic Acid versus Aminolaevulinic Acid Photodynamic Therapy of Actinic Keratosis with Low Doses of Red-Light LED Illumination: Results of Long-Term Follow-Up.

Photodynamic therapy (PDT) treatment for multiple actinic keratosis (AK) has been found effective when lower doses of red light were used with methyl aminolaevulinic acid (MAL). The aim of this study was to compare the results of lower doses of red light conventional PDT (h-PDT, 16 J/cm2) with MAL and aminolaevulinic acid (ALA) in a long-term follow-up. Patients with more than five symmetrical AK on the scalp who were candidates for PDT were selected and divided randomly between MAL and ALA treatment and patients were followed at 3 and 12 months. The responses were assessed by counting the total AK and the AK per patient. Pain and adverse events were also compiled. A total of 46 patients were treated, 24 with MAL, and 22 with ALA. The two groups were comparable at baseline (p > 0.005). No significant differences were found in the results of both treatments at 12 months, despite ALA exhibiting slightly better results at 3 months. No differences in pain and adverse events were assessed. Both ALA and MAL were effective when lower doses of red light were used in c-PDT. Long term efficacy was also documented. Further studies are necessary to determine the inferior point of red-light illumination without losing efficacy.

Overproduction of hydrogen sulfide, generated by cystathionine ß-synthase, disrupts brain wave patterns and contributes to neurobehavioral dysfunction in a rat model of down syndrome.

Using a novel rat model of Down syndrome (DS), the functional role of the cystathionine-ß-synthase (CBS)/hydrogen sulfide (H2S) pathway was investigated on the pathogenesis of brain wave pattern alterations and neurobehavioral dysfunction. Increased expression of CBS and subsequent overproduction of H2S was observed in the brain of DS rats, with CBS primarily localizing to astrocytes and the vasculature. DS rats exhibited neurobehavioral defects, accompanied by a loss of gamma brain wave activity and a suppression of the expression of multiple pre- and postsynaptic proteins. Aminooxyacetate, a prototypical pharmacological inhibitor of CBS, increased the ability of the DS brain tissue to generate ATP in vitro and reversed the electrophysiological and neurobehavioral alterations in vivo. Thus, the CBS/H2S pathway contributes to the pathogenesis of neurological dysfunction in DS, most likely through dysregulation of cellular bioenergetics and gene expression.

[Effectiveness and safety of intravesical hyaluronic acid for symptom control in chronic bladder diseases.] / Efectividad y seguridad del ácido hialurónico intravesical para el control de los síntomas en cistopatías crónicas.

INTRODUCTION: Chronic bladder disorders are a common condition. Endovesical hyaluronic acid is one of the therapeutic options for these patients. It is intended to verify the effectiveness and safety of treatment with intravesical instillations of hyaluronic acidin patients with bladder symptoms. MATERIAL AND METHODS: We present a series of 32 patients who received intravesical instillations of hyaluronic acid. Demographic characteristics, tolerance, and complications were analyzed, and symptoms before and after treatment were compared. Symptomatic relief achieved with treatment was assessed using the Patient Global Improvement Impression Scale (PGI-I). RESULTS: The median age was 74 years (IQR 60-78) and 65.6% were women. Median follow-up was 10 months (IQR 7-14). Eleven patients were diagnosed with radiotherapy-induced cystitis, 17 with bladder pain syndrome/interstitial cystitis (BPS/IC), and 4 with recurrent cystitis. After treatment, symptoms improved in 81.8% of patients with radical cystitis, 82.3% of patients with BPS/IC, and 75% of the patients with recurrent cystitis. The incidence of hematuria was reduced from 46.9% to 9.4% (p<0.001), filing symptoms from 62.5% to 12.5% (p<0.001) and pain from 40.6% to 12.5% (p= 0.004). 100% of the patients tolerated the treatment well and only 2 adverse effects were recorded (urinary tract infection and acute urine retention). During follow-up, 65.6% showed total control of symptoms and 15.6% partial control, achieving a greater response in the group of patients with hematuria (73.3%). 61.3% of the patients perceived relief of symptoms after treatment according to the PGI-I scale. 88.9% maintained symptomatic improvement at the end of the follow-up. CONCLUSION: Intravesical hyaluronic acid is a safe and effective treatment for filling symptoms, hematuria, and pain in patients with chronic cystopathies. Patients with radiotherapy-induced cystitis seem to especially benefit from treatment.

INTRODUCCIÓN: Las cistopatías crónicas son una patología frecuente. El ácido hialurónico endovesical es una de las opciones terapéuticas para estos pacientes. Se pretende verificar la efectividad y seguridad del tratamiento con instilaciones intravesicales de ácido hialurónico en pacientes con síntomas vesicales.MATERIAL Y MÉTODOS: Se presenta una serie de 32 pacientes que recibieron instilaciones intravesicales de ácido hialurónico. Se analizaron las características demográficas, tolerancia y complicaciones, y se compararon los síntomas antes y después del tratamiento. El alivio sintomático conseguido con el tratamiento se evaluó mediante la escala de impresión de mejoría global del paciente (PGI-I).RESULTADOS: La mediana de edad fue de 74 años (IQR60-78), siendo el 65,6% mujeres. La mediana de seguimiento fue 10 meses (IQR 7-14). Once pacientes fueron diagnosticados de cistitis rádica, 17 de síndrome de dolor vesical/cistitis intersticial (SDV/CI) y 4 de cistitis de repetición. Tras el tratamiento mejoraron los síntomas el 81,8% de los pacientes con cistitis rádica, el 82,3% de los pacientes con SDV/CI y el 75% de los pacientes con cistitis recurrentes. La incidencia de hematuria se redujo del 46,9% al 9,4% (p<0,001), los síntomas de llenado del 62,5% al 12,5% (p<0,001) y el dolor de un 40,6% al 12,5% (p=0,004). El 100% de los pacientes toleró bien el tratamiento y sólo se registraron 2 efectos adversos (infección del tracto urinario y retención agudade orina). Durante el seguimiento un 65,6% mostró un control total de los síntomas y un 15,6% un control parcial, consiguiendo una respuesta mayor en el grupo de pacientes con hematuria (73,3%). El 61,3% de los pacientes percibió alivio de los síntomas tras el tratamiento según la escala PGI-I. El 88,9% mantiene la mejoría de los síntomas al finalizar el seguimiento.CONCLUSIÓN: El ácido hialurónico intravesical es un tratamiento seguro y efectivo para los síntomas de llenado, hematuria y dolor en pacientes con cistopatías crónicas. Los pacientes con cistitis rádica parecen beneficiarse especialmente del tratamiento.

Effects of Integrated Amrita Meditation Technique on Anxiety, Depression, and Plasma Neurotransmitters on a Healthy Population: A Randomized Controlled Trial Followed by a Case-Control Study.

Objective: We aimed to study the short-term effects of Integrated Amrita Meditation (IAM) technique in anxiety and depression states and to have a better understanding on the underlying physiological changes related to short-term and long-term IAM practice. Design: Short-term IAM practitioners (ST-IAM) and long-term IAM practitioners (LT-IAM) were compared to control groups of the same age and naïve to yoga and meditation (ST-control and LT-control, respectively). Settings/Location: Kerala, India. Subjects: People that did not suffer from any major medical condition. All participants were naïve to yoga and meditation practices, except for the 5 LT-IAM practitioners. Intervention: ST-IAM practitioners underwent 2 community IAM practices and 5 individual IAM practices. LT-IAM practitioners (performing IAM regularly for more than 4 years) underwent a community IAM practice before the study. Outcome measures: Anxiety and depression states and physiological parameters from ST-IAM and ST-control groups were assed in two different visits (before and after the week of IAM practice or control condition). LT-IAM and LT-control subjects' physiological measurements were taken in only one visit. Results: Short-term IAM practice significantly decreased anxiety and depression states; two way ANOVA indicated differences on anxiety and depression scores across visits between ST-IAM and ST-control groups (Group effect: F(1, 25) = 6.083, p = 0.0209; F(1, 25) = 4.449, p = 0.0451). However, no changes were observed on their physiological parameters (heart rate, blood pressure, oxygen saturation, and dopamine and GABA plasma levels). Interestingly, LT-IAM practitioners showed increased GABA plasma levels than the LT-control group (p = 0.0358, t = 2.521, df = 8). Conclusions: Our study indicates the possible role of IAM technique on modulations of the plasma GABAergic levels and shows that one week of IAM practice is accompanied by a significant decrease of anxiety and depression states in the healthy population.

New Sequence Type ST3449 in Multidrug-Resistant Pseudomonas aeruginosa Isolates from a Cystic Fibrosis Patient.

Pseudomonas aeruginosa is one of the most critical bacterial pathogens associated with chronic infections in cystic fibrosis patients. Here we show the phenotypic and genotypic characterization of five consecutive multidrug-resistant isolates of P. aeruginosa collected during a month from a CF patient with end-stage lung disease and fatal outcome. The isolates exhibited distinct colony morphologies and pigmentation and differences in their capacity to produce biofilm and virulence potential evaluated in larvae of Galleria mellonella. Whole genome-sequencing showed that isolates belonged to a novel sequence type ST3449 and serotype O6. Analysis of their resistome demonstrated the presence of genes blaOXA-396, blaPAO, aph(3')-IIb, catB, crpP and fosA and new mutations in chromosomal genes conferring resistance to different antipseudomonal antibiotics. Genes exoS, exoT, exoY, toxA, lasI, rhlI and tse1 were among the 220 virulence genes detected. The different phenotypic and genotypic features found reveal the adaptation of clone ST3449 to the CF lung environment by a number of mutations affecting genes related with biofilm formation, quorum sensing and antimicrobial resistance. Most of these mutations are commonly found in CF isolates, which may give us important clues for future development of new drug targets to combat P. aeruginosa chronic infections.

Optogenetic Stimulation of Basal Forebrain Parvalbumin Neurons Activates the Default Mode Network and Associated Behaviors.

Activation of the basal forebrain (BF) has been associated with increased attention, arousal, and a heightened cortical representation of the external world. In addition, BF has been implicated in the regulation of the default mode network (DMN) and associated behaviors. Here, we provide causal evidence for a role of BF in DMN regulation, highlighting a prominent role of parvalbumin (PV) GABAergic neurons. The optogenetic activation of BF PV neurons reliably drives animals toward DMN-like behaviors, with no effect on memory encoding. In contrast, BF electrical stimulation enhances memory performance and increases DMN-like behaviors. BF stimulation has a correlated impact on peptide regulation in the BF and ACC, enhancing peptides linked to grooming behavior and memory functions, supporting a crucial role of the BF in DMN regulation. We suggest that in addition to enhancing attentional functions, the BF harbors a network encompassing PV GABAergic neurons that promotes self-directed behaviors associated with the DMN.

Short-Term Effects of PENS versus Dry Needling in Subjects with Unilateral Mechanical Neck Pain and Active Myofascial Trigger Points in Levator Scapulae Muscle: A Randomized Controlled Trial.

Procedures such as dry needling (DN) or percutaneous electrical nerve stimulation (PENS) are commonly proposed for the treatment of myofascial trigger points (MTrP). The aim of the present study is to investigate if PENS is more effective than DN in the short term in subjects with mechanical neck pain. This was an evaluator-blinded randomized controlled trial. Subjects were recruited through announcements and randomly allocated into DN or PENS groups. Pain intensity, disability, pressure pain threshold (PPT), range of motion (ROM), and side-bending strength were measured. The analyses included mixed-model analyses of variance and pairwise comparisons with Bonferroni correction. The final sample was composed of 44 subjects (22 per group). Both groups showed improvements in pain intensity (ηp2 = 0.62; p < 0.01), disability (ηp2 = 0.74; p < 0.01), PPT (ηp2 = 0.79; p < 0.01), and strength (ηp2 = 0.37; p < 0.01). The PENS group showed greater improvements in disability (mean difference, 3.27; 95% CI, 0.27-6.27) and PPT (mean difference, 0.88-1.35; p < 0.01). Mixed results were obtained for ROM. PENS seems to produce greater improvements in PPT and disability in the short term.

Latency to Reward Predicts Social Dominance in Rats: A Causal Role for the Dopaminergic Mesolimbic System.

Reward signals encoded in the mesolimbic dopaminergic system guide approach/seeking behaviors to all varieties of life-supporting stimuli (rewards). Differences in dopamine (DA) levels have been found between dominant and submissive animals. However, it is still unclear whether these differences arise as a consequence of the rewarding nature of the acquisition of a dominant rank, or whether they preexist and favor dominance by promoting reward-seeking behavior. Given that acquisition of a social rank determines animals' priority access to resources, we hypothesized that differences in reward-seeking behavior might affect hierarchy establishment and that modulation of the dopaminergic system could affect the outcome of a social competition. We characterized reward-seeking behaviors based on rats' latency to get a palatable-reward when given temporary access to it. Subsequently, rats exhibiting short (SL) and long (LL) latency to get the rewards cohabitated for more than 2 weeks, in order to establish a stable hierarchy. We found that SL animals exhibited dominant behavior consistently in social competition tests [for palatable-rewards and two water competition tests (WCTs)] after hierarchy was established, indicating that individual latency to rewards predicted dominance. Moreover, because SL animals showed higher mesolimbic levels of DA than LL rats, we tested whether stimulation of mesolimbic DA neurons could affect the outcome of a social competition. Indeed, a combination of optical stimulation of mesolimbic DA neurons during individual training and during a social competition test for palatable rewards resulted in improved performance on this test.

Mutations in the zebrafish hmgcs1 gene reveal a novel function for isoprenoids during red blood cell development.

Erythropoiesis is the process by which new red blood cells (RBCs) are formed and defects in this process can lead to anemia or thalassemia. The GATA1 transcription factor is an established mediator of RBC development. However, the upstream mechanisms that regulate the expression of GATA1 are not completely characterized. Cholesterol is 1 potential upstream mediator of GATA1 expression because previously published studies suggest that defects in cholesterol synthesis disrupt RBC differentiation. Here we characterize RBC development in a zebrafish harboring a single missense mutation in the hmgcs1 gene (Vu57 allele). hmgcs1 encodes the first enzyme in the cholesterol synthesis pathway and mutation of hmgcs1 inhibits cholesterol synthesis. We analyzed the number of RBCs in hmgcs1 mutants and their wild-type siblings. Mutation of hmgcs1 resulted in a decrease in the number of mature RBCs, which coincides with reduced gata1a expression. We combined these experiments with pharmacological inhibition and confirmed that cholesterol and isoprenoid synthesis are essential for RBC differentiation, but that gata1a expression is isoprenoid dependent. Collectively, our results reveal 2 novel upstream regulators of RBC development and suggest that appropriate cholesterol homeostasis is critical for primitive erythropoiesis.

Cambios en el IMC posterior a gastrectomía vertical en un grupo de pacientes de una clínica de la ciudad de Medellín, 2016-2018 / Changes in the Body Mass Index After Vertical Gastrectomy in a Group of Patients of a Clinic in the City of Medellín, 2016-2018

Resumen Antecedentes: la OMS define la obesidad como un depósito excesivo de grasa que puede ser lesivo para la salud con un gran impacto social. En las últimas dos décadas, se ha incrementado la realización de las cirugías bariátricas como una alternativa para reducir el exceso de peso y grasa corporal, entre las que se destaca la gastrectomía vertical. Objetivo: describir el cambio en el IMC, hábitos alimentarios y actividad física en un grupo de pacientes sometidos a la cirugía de gastrectomía vertical en una clínica de la ciudad de Medellín, entre 2016-2018. Materiales y métodos: estudio descriptivo retrospectivo, en el cual se revisaron historias clínicas de 49 pacientes, 13 hombres y 36 mujeres, sometidos a gastrectomía vertical en una clínica privada de la ciudad de Medellín. Resultados: los pacientes iniciaron con un promedio de IMC de 34,2 kg/m2 y al año posoperatorio descendieron a uno de 24,4 kg/m2 (p=0,00); también hubo una tendencia de mejoría en los hábitos alimentarios, como comer entre comidas y no consumir dulces ni gaseosas. Conclusiones: la cirugía de gastrectomía vertical muestra ser una técnica apropiada para el descenso del IMC, al menos en el primer año de ser realizada.

Abstract Background: The WHO defines obesity as an excess deposit of fat that can be harmful to health with a great social impact. In the last two decades, bariatric surgery has increased as an alternative to reduce excess weight and body fat, of which we highlight the vertical gastrectomy. Objective: To describe the change in Body Mass Index, dietary behaviors, and physical activity in a group of patients undergoing vertical Gastrectomy surgery in a clinic in Medellin, Colombia between 2016-2018. Materials and Methods: Retrospective descriptive study, in which medical records were reviewed in 49 patients, 13 men and 36 women, who underwent vertical gastrectomy in a private clinic in Medellin. Results: Patients started with an average BMI of 34.2 kg/m2 and one year post-surgery they descended to an average BMI of 24.4 kg/m2 (p=0.00); also, an improvement in eating habits such as eating between meals, and less consumption of sweets and soft drinks was found. Conclusions: Vertical Gastrectomy surgery proves to be an appropriate technique for decreasing BMI, at least in the first year post-operative.

High Prevalence of Extensively Drug-resistant Acinetobacter baumannii at a Children Hospital in Bolivia.

Acinetobacter baumannii causes serious hospital-acquired infections and has been positioned as a priority organism by the World Health Organization. This study includes 36 A. baumannii isolates from a children hospital recovered between March 2014 and May 2015 in Cochabamba. The majority of the isolates were recovered from blood cultures (n = 10, 31.3%) and respiratory samples (n = 11, 34.4%); 53% of the patients were younger than 1 month old. Most of these isolates (n = 30, 80.6%) were extremely drug resistant and 8.3% were multidrug resistant. The circulation of 2 predominant clones including 25 isolates was determined by pulsed-field gel electrophoresis; 9 of the isolates were considered sporadic strains. The isolates grouped in the predominant clones and 5 of the unrelated sporadic strains were single-locus variant or double locus variant of clonal complex (CC110), belonging to international clone 7; the rest of the isolates were single-locus variant or double locus variant of another clonal complex. All the carbapenem-resistant isolates (88.9%) carried the blaOXA-23-like in a similar structure to Tn2008 located on the chromosome, and the aac(3)-IIa gene was present in all the aminoglycoside-resistant isolates (86.1%). Strong biofilm producers were found among these isolates, being the strongest ones those recovered from the hospital environment, catheter, blood and cerebrospinal fluid (CSF) all of them belonged to the unrelated sporadic strains. The present study demonstrated the predominance and spread of closely related extremely drug-resistant A. baumannii isolates, what confers increasing risk to children and is of major concern because of the kind of infections and the lack of therapeutic alternatives to treat them.

Stress Impacts the Regulation Neuropeptides in the Rat Hippocampus and Prefrontal Cortex.

Adverse life experiences increase the lifetime risk to several stress-related psychopathologies, such as anxiety or depressive-like symptoms following stress in adulthood. However, the neurochemical modulations triggered by stress have not been fully characterized. Neuropeptides play an important role as signaling molecules that contribute to physiological regulation and have been linked to neurological and psychiatric diseases. However, little is known about the influence of stress on neuropeptide regulation in the brain. Here, we have performed an exploratory study of how neuropeptide expression at adulthood is modulated by experiencing a period of multiple stressful experiences. We have targeted hippocampus and prefrontal cortex (PFC) brain areas, which have previously been shown to be modulated by stressors, employing a targeted liquid chromatography-mass spectrometry (LC-MS) based approach that permits broad peptide coverage with high sensitivity. We found that in the hippocampus, Met-enkephalin, Met-enkephalin-Arg-Phe, and Met-enkephalin-Arg-Gly-Leu were upregulated, while Leu-enkephalin and Little SAAS were downregulated after stress. In the PFC area, Met-enkephalin-Arg-Phe, Met-enkephalin-Arg-Gly-Leu, peptide PHI-27, somatostatin-28 (AA1-12), and Little SAAS were all downregulated. This systematic evaluation of neuropeptide alterations in the hippocampus and PFC suggests that stressors impact neuropeptides and that neuropeptide regulation is brain-area specific. These findings suggest several potential peptide candidates, which warrant further investigations in terms of correlation with depression-associated behaviors.

PTEN recruitment controls synaptic and cognitive function in Alzheimer's models.

Dyshomeostasis of amyloid-ß peptide (Aß) is responsible for synaptic malfunctions leading to cognitive deficits ranging from mild impairment to full-blown dementia in Alzheimer's disease. Aß appears to skew synaptic plasticity events toward depression. We found that inhibition of PTEN, a lipid phosphatase that is essential to long-term depression, rescued normal synaptic function and cognition in cellular and animal models of Alzheimer's disease. Conversely, transgenic mice that overexpressed PTEN displayed synaptic depression that mimicked and occluded Aß-induced depression. Mechanistically, Aß triggers a PDZ-dependent recruitment of PTEN into the postsynaptic compartment. Using a PTEN knock-in mouse lacking the PDZ motif, and a cell-permeable interfering peptide, we found that this mechanism is crucial for Aß-induced synaptic toxicity and cognitive dysfunction. Our results provide fundamental information on the molecular mechanisms of Aß-induced synaptic malfunction and may offer new mechanism-based therapeutic targets to counteract downstream Aß signaling.

Carbapenem-resistant Klebsiella pneumoniae isolates from Egypt containing blaNDM-1 on IncR plasmids and its association with rmtF.

OBJECTIVES: The aim of this study was to characterize carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates recovered from clinical specimens at a tertiary care hospital in Egypt over a period of 15 months. METHODS: Eight CRKP isolates were included in this study. The minimum inhibitory concentrations of different antibiotics were determined by broth microdilution and Etest methods. Multilocus sequence typing was performed. Antibiotic resistance genes were assessed by PCR and DNA sequencing. Plasmid analysis was done by S1 nuclease digestion of whole genomic DNA followed by pulsed-field gel electrophoresis (S1-PFGE). RESULT: Eight carbapenem-resistant NDM-1-producing K. pneumoniae isolates of three different sequence types (ST) were identified (ST147, ST11, and ST17), in which blaNDM-1 was carried by either IncR or untypeable plasmids. Seven out of the eight isolates also contained the rmtF methylase gene. CONCLUSION: This study describes the occurrence of IncR plasmids carrying blaNDM-1 and rmtF in Egypt, raising concerns regarding this type of replicon and its role in the transmission of these resistance determinants.

Mutational and acquired carbapenem resistance mechanisms in multidrug resistant Pseudomonas aeruginosa clinical isolates from Recife, Brazil.

An investigation was carried out into the genetic mechanisms responsible for multidrug resistance in nine carbapenem-resistant Pseudomonas aeruginosa isolates from different hospitals in Recife, Brazil. Susceptibility to antimicrobial agents was determined by broth microdilution. Polymerase chain reaction (PCR) was employed to detect the presence of genes encoding ß-lactamases, aminoglycoside-modifying enzymes (AMEs), 16S rRNA methylases, integron-related genes and OprD. Expression of genes coding for efflux pumps and AmpC cephalosporinase were assessed by quantitative PCR. The outer membrane proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The blaSPM-1, blaKPC-2 and blaGES-1 genes were detected in P. aeruginosa isolates in addition to different AME genes. The loss of OprD in nine isolates was mainly due to frameshift mutations, premature stop codons and point mutations. An association of loss of OprD with the overexpression of MexAB-OprM and MexXY-OprM was observed in most isolates. Hyper-production of AmpC was also observed in three isolates. Clonal relationship of the isolates was determined by repetitive element palindromic-PCR and multilocus sequence typing. Our results show that the loss of OprD along with overexpression of efflux pumps and ß-lactamase production were responsible for the multidrug resistance in the isolates analysed.

Mutational and acquired carbapenem resistance mechanisms in multidrug resistant Pseudomonas aeruginosa clinical isolates from Recife, Brazil

An investigation was carried out into the genetic mechanisms responsible for multidrug resistance in nine carbapenem-resistant Pseudomonas aeruginosaisolates from different hospitals in Recife, Brazil. Susceptibility to antimicrobial agents was determined by broth microdilution. Polymerase chain reaction (PCR) was employed to detect the presence of genes encoding β-lactamases, aminoglycoside-modifying enzymes (AMEs), 16S rRNA methylases, integron-related genes and OprD. Expression of genes coding for efflux pumps and AmpC cephalosporinase were assessed by quantitative PCR. The outer membrane proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The blaSPM-1, blaKPC-2 and blaGES-1 genes were detected in P. aeruginosaisolates in addition to different AME genes. The loss of OprD in nine isolates was mainly due to frameshift mutations, premature stop codons and point mutations. An association of loss of OprD with the overexpression of MexAB-OprM and MexXY-OprM was observed in most isolates. Hyper-production of AmpC was also observed in three isolates. Clonal relationship of the isolates was determined by repetitive element palindromic-PCR and multilocus sequence typing. Our results show that the loss of OprD along with overexpression of efflux pumps and β-lactamase production were responsible for the multidrug resistance in the isolates analysed.

Multiwalled carbon nanotubes hinder microglia function interfering with cell migration and phagocytosis.

The intranasal drug delivery route provides exciting expectations regarding the application of engineered nanomaterials as nano-medicines or drug-delivery vectors into the brain. Among nanomaterials, multiwalled CNTs (MWCNTs) are some of the best candidates for brain cancer therapy since they are well known to go across cellular barriers and display an intrinsic ability to block cancer cell proliferation triggering apoptosis. This study reveals that microglial cells, the brain macrophages and putative vehicles for MWCNTs into the brain, undergo a dose-dependent cell division arrest and apoptosis when treated with MWCNTs. Moreover, it is shown that MWCNTs severely interfere with both cell migration and phagocytosis in live microglia. These results lead to a re-evaluation of the safety of inhaled airborne CNTs and provide strategic clues of how to biocompatibilize MWCNTs to reduce brain macrophage damage and to develop new nanodrugs.

Ectophosphorylation of CD36 regulates cytoadherence of Plasmodium falciparum to microvascular endothelium under flow conditions.

The adhesion of Plasmodium falciparum-infected erythrocytes (IRBCs) to human dermal microvascular endothelial cells (HDMECs) under flow conditions is regulated by a Src family kinase- and alkaline phosphatase (AP)-dependent mechanism. In this study, we showed that the target of the phosphatase activity is the ectodomain of CD36 at threonine-92 (Thr92). Mouse fibroblasts (NIH 3T3 cells) transfected with wild-type CD36 or a mutant protein in which Thr92 was substituted by Ala supported the rolling and adhesion of IRBCs. However, while the Src family kinase inhibitors PP1 and PP2 and the specific AP inhibitor levamisole significantly reduced IRBC adhesion to wild-type CD36 transfectants as with HDMECs, the inhibitors had no effect on IRBC adhesion to the mutant cells. Using a phosphospecific antibody directed at a 12-amino-acid peptide spanning Thr92, we demonstrated directly that CD36 was constitutively phosphorylated and could be dephosphorylated by exogenous AP. Endothelial CD36 was likewise constitutively phosphorylated. The phosphospecific antibody inhibited IRBC adhesion to HDMECs that could be reversed by preincubating the antibody with the phosphorylated but not the nonphosphorylated peptide. Pretreatment of HDMECs with AP abrogated the effect of PP1 on IRBC adhesion. Collectively, these results are consistent with a critical role for CD36 dephosphorylation through Src family kinase activation in regulating IRBC adhesion to vascular endothelium.