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Acute hepatic porphyrias (AHPs) are a family of rare, autosomal, dominantly inherited conditions characterized by abnormalities in the production of heme. Advances in molecular engineering have provided new therapeutic possibilities for modifying the heme synthetic pathway in patients with porphyria. In particular, the RNA interference therapeutic givosiran was approved for the treatment of adults and adolescents with AHP aged >12 years based on the positive results of the phase III trial ENVISION. Despite the extended characterization of the activity of givosiran in clinical trials, reports on the long-term effects and effectiveness of the treatment in clinical practice are still scant. To fill this gap, this case series describes a monocentric Italian cohort of AHP patients treated with givosiran. Overall, our real-life experience supports the clinical evidence that long-term treatment with givosiran is well tolerated and able to provide sustained and continuous benefit to patients with acute intermittent porphyria, as reflected by the reduction in the frequency of attacks. In our series, givosiran treatment was also associated with improvement in assessments of quality of life, pain and fatigue.
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The gut microbiota has gained increasing attention in recent years due to its significant impact on colorectal cancer (CRC) development and progression. The recent detection of bacterial DNA load in plasma holds promise as a potential non-invasive approach for early cancer detection. The aim of this study was to examine the quantity of bacterial DNA present in the plasma of 50 patients who have CRC in comparison to 40 neoplastic disease-free patients, as well as to determine if there is a correlation between the amount of plasma bacterial DNA and various clinical parameters. Plasma bacterial DNA levels were found to be elevated in the CRC group compared to the control group. As it emerged from the logistic analysis (adjusted for age and gender), these levels were strongly associated with the risk of CRC (OR = 1.02, p < 0.001, 95% C.I.: 1.01-1.03). Moreover, an association was identified between a reduction in tumor mass and the highest tertile of plasma bacterial DNA. Our findings indicate that individuals with CRC displayed a higher plasma bacterial DNA load compared to healthy controls. This observation lends support to the theory of heightened bacterial migration from the gastrointestinal tract to the bloodstream in CRC. Furthermore, our results establish a link between this phenomenon and the size of the tumor mass.
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Increased values of the FIB-4 index appear to be associated with poor clinical outcomes in COVID-19 patients. This study aimed to develop and validate predictive mortality models, using data upon admission of hospitalized patients in four COVID-19 waves between March 2020 and January 2022. A single-center cohort study was performed on consecutive adult patients with Covid-19 admitted at the Fondazione Policlinico Gemelli IRCCS (Rome, Italy). Artificial intelligence and big data processing were used to retrieve data. Patients and clinical characteristics of patients with available FIB-4 data derived from the Gemelli Generator Real World Data (G2 RWD) were used to develop predictive mortality models during the four waves of the COVID-19 pandemic. A logistic regression model was applied to the training and test set (75%:25%). The model's performance was assessed by receiver operating characteristic (ROC) curves. A total of 4936 patients were included. Hypertension (38.4%), cancer (12.15%) and diabetes (16.3%) were the most common comorbidities. 23.9% of patients were admitted to ICU, and 12.6% had mechanical ventilation. During the study period, 762 patients (15.4%) died. We developed a multivariable logistic regression model on patient data from all waves, which showed that the FIB-4 score > 2.53 was associated with increased mortality risk (OR = 4.53, 95% CI 2.83-7.25; p ≤ 0.001). These data may be useful in the risk stratification at the admission of hospitalized patients with COVID-19.
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COVID-19 , Adulto , Humanos , SARS-CoV-2 , ARN Viral , Mortalidad Hospitalaria , Estudios de Cohortes , Pandemias , Inteligencia Artificial , Estudios RetrospectivosRESUMEN
Desmosomes are essential structures for ensuring tissue functions, and their deregulation is involved in the development of colorectal cancer (CRC). JUP (γ-catenin) is a desmosome adhesion component that also acts as a signaling hub, suggesting its potential involvement in CRC progression. In this context, we recently demonstrated that miR-195-5p regulated JUP and desmosome cadherins expression. In addition, miR-195-5p gain of function indirectly modulated the expression of key effectors of the Wnt pathway involved in JUP-dependent signaling. Here, our purpose was to demonstrate the aberrant expression of miR-195-5p and JUP in CRC patients and to functionally characterize the role of miR-195-5p in the regulation of desmosome function. First, we showed that miR-195-5p was downregulated in CRC tumors compared to adjacent normal tissue. Then, we demonstrated that JUP expression was significantly increased in CRC tissues compared to adjacent normal tissues. The effects of miR-195-5p on CRC progression were assessed using in vitro transient transfection experiments and in vivo miRNA administration. Increased miR-195-5p in colonic epithelial cells strongly inhibits cell proliferation, viability, and invasion via JUP. In vivo gain of function of miR-195-5p reduced the numbers and sizes of tumors and significantly ameliorated the histopathological changes typical of CRC. In conclusion, our findings indicate a potential pharmacological target based on miR-195-5p replacement as a new therapeutic approach in CRC.
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Neoplasias del Colon , MicroARNs , Humanos , Desmosomas/genética , gamma Catenina , Regulación hacia Abajo/genética , Neoplasias del Colon/genética , MicroARNs/genéticaRESUMEN
Heme is a member of the porphyrins family of cyclic tetrapyrroles and influences various cell processes and signalling pathways. Enzyme deficiencies in the heme biosynthetic pathway provoke rare human inherited metabolic diseases called porphyrias. Protein levels and activity of enzymes involved in the heme biosynthetic pathway and especially 5'-Aminolevulinate Synthase 1 are featured by 24-h rhythmic oscillations driven by the biological clock. Heme biosynthesis and circadian pathways intermingle with mutual modulatory roles. Notably, heme is a ligand of important cogs of the molecular clockwork, which upon heme binding recruit co-repressors and inhibit the transcription of numerous genes enriching metabolic pathways and encoding functional proteins bringing on crucial cell processes. Herein, we assessed mRNA levels of circadian genes in patients suffering from porphyrias and found several modifications of core clock genes and clock-controlled genes expression, associated with metabolic and electrolytic changes. Overall, our results show an altered expression of circadian genes accompanying heme biosynthesis disorders and confirm the need to deepen the knowledge of the mechanisms through which the alteration of the circadian clock circuitry could take part in determining signs and symptoms of porphyria patients and then again could represent a target for innovative therapeutic strategies.
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OBJECTIVES: Differential diagnosis between pancreatic ductal adenocarcinoma (PDAC) and benign mimickers can be very difficult on small histological samples, such as fine needle aspiration biopsies (FNAB). We aimed to investigate the diagnostic value of immunostaining for IMP3, Maspin, S100A4, S100P, TFF2, and TFF3 in FNAB pancreatic lesions. METHODS: We prospectively enrolled 20 consecutive patients with suspected PDAC, collecting FNABs at our department between 2019 and 2021. RESULTS: Three of the 20 enrolled patients resulted negative for all immunohistochemical markers, while all the others were positive for Maspin. All other immunohistochemistry (IHC) markers had sensitivity and accuracy of less than 100%. On the basis of the IHC, the preoperative diagnosis on FNAB was nonmalignant lesions in the IHC negative cases and PDAC in the others. All patients subsequently underwent surgery for the pancreatic solid mass demonstrated by imaging techniques. The concordance between the preoperative and postoperative diagnosis was 100%; all IHC negative samples were diagnosed on surgical specimens as chronic pancreatitis and Maspin-positive samples as PDAC. CONCLUSIONS: Our results demonstrate that even in the presence of little histological material, such as FNAB, the use of Maspin alone is sufficient to discriminate between PDAC and nonmalignant pancreatic lesions, with 100% accuracy.
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Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Biopsia con Aguja Fina , Estudios Prospectivos , Inmunohistoquímica , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/patología , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/cirugía , Carcinoma Ductal Pancreático/patología , Neoplasias PancreáticasRESUMEN
Porphyrias are a group of diseases that are clinically and genetically heterogeneous and originate mostly from inherited dysfunctions of specific enzymes involved in heme biosynthesis. Such dysfunctions result in the excessive production and excretion of the intermediates of the heme biosynthesis pathway in the blood, urine, or feces, and these intermediates are responsible for specific clinical presentations. Porphyrias continue to be underdiagnosed, although laboratory diagnosis based on the measurement of metabolites could be utilized to support clinical suspicion in all symptomatic patients. Moreover, the measurement of enzymatic activities along with a molecular analysis may confirm the diagnosis and are, therefore, crucial for identifying pre-symptomatic carriers. The present review provides an overview of the laboratory assays used most commonly for establishing the diagnosis of porphyria. This would assist the clinicians in prescribing appropriate diagnostic testing and interpreting the testing results.
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Pleomorphic hyalinizing angiectatic tumor (PHAT) is a very rare entity of soft tissue considered a "neoplasm of uncertain behaviour of connective or other soft tissue" by the World Health Organization (2020). It develops in subcutaneous tissue of the lower extremities, more frequently in the region of the ankle and foot, and rarely as a deep-seated soft tissue mass in locations such as the perineum, buttock, arms, head and neck, and viscera. Although inconsistent cytogenetic data have been reported on PHAT so far, there are potential morphological and genetic overlaps with hemosiderotic fibrolipomatous tumor (HFLT) and myxoinflammatory fibroblastic sarcoma (MIFS). Here we report a case of PHAT at the level of the upper third of the right thigh in a 48-year-old patient and we also focus on the differential diagnoses of these entities and conduct a literature review of reported cases.
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BACKGROUND: Erythropoietic protoporphyria (EPP) is a rare inherited disease associated with heme metabolism, characterized by severe life-long photosensitivity and liver involvement. OBJECTIVE: To provide epidemiological data of EPP in Italy. MATERIALS & METHODS: Prospective/retrospective data of EPP patients were collected by an Italian network of porphyria specialist centres (Gruppo Italiano Porfiria, GrIP) over a 20-year period (1996-2017). RESULTS: In total, 179 patients (79 females) with a clinical and biochemical diagnosis of EPP were assessed, revealing a prevalence of 3.15 cases per million persons and an incidence of 0.13 cases per million persons/year. Incidence significantly increased after 2009 (due to the availability of alfa-melanotide, which effectively limits skin photosensitivity). Mean age at diagnosis was 28 years, with only 22 patients (12.2%) diagnosed ≤10 years old. Gene mutations were assessed in 173 (96.6%) patients; most (164; 91.3%) were FECH mutations on one allele in association with the hypomorphic variant, c.315-48C, on the other (classic EPP), and nine (5.2%) were ALAS2 mutations (X-linked EPP). Only one case of autosomal recessive EPP was observed. Of the 42 different FECH mutations, 15 are novel, three mutations collectively accounted for 45.9% (75/164) of the mutations (c.215dupT [27.2%], c.901_902delTG [11.5%] and c.67 + 5G > A [7.2%]), and frameshift mutations were prevalent (33.3%). A form of light protection was used by 109/179 (60.8%) patients, and 100 (56%) had at least one α-melanotide implant. Three cases of severe acute liver involvement, requiring OLT, were observed. CONCLUSION: These data define, for the first time, the clinical and molecular epidemiology of EPP in Italy.
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Protoporfiria Eritropoyética/epidemiología , Protoporfiria Eritropoyética/genética , 5-Aminolevulinato Sintetasa/genética , Adulto , Estudios Transversales , Femenino , Ferroquelatasa/genética , Genes Recesivos , Genes Ligados a X , Humanos , Incidencia , Italia , Masculino , Epidemiología Molecular , Mutación , Prevalencia , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
CONTEXT: Tasks that activate the lateral trunk muscles are clinically relevant in athletic and rehabilitation programs. However, no electromyography studies have compared tasks aimed at lateral trunk muscle activation. OBJECTIVE: To compare the activation magnitudes of the internal and external obliques between 4 tasks targeting recruitment of the lateral trunk muscles, including the proposal of a novel assessment. DESIGN: Comparative laboratory study. SETTING: University-based biomechanics laboratory. PARTICIPANTS: Sixty-three participants (35 females, age = 23.6 [2.0] y, height = 1.72 [0.10] m, mass = 70.7 [14.4] kg, body mass index = 23.6 [2.86] kg/m2). INTERVENTION(S): Surface electromyography data were recorded bilaterally from the internal and external obliques while the participants performed 2 maximum voluntary contraction tasks followed by 4 isometric tasks. The isometric tasks included feet-elevated side-supported, trunk-elevated side-unsupported, lateral plank, and side-lying hip abduction. MAIN OUTCOME MEASURES: Maximum voluntary contraction-normalized and integrated muscle activities were calculated for targeted and nontargeted muscles in each task. A side-by-task analysis of variance with Bonferroni correction was conducted. RESULTS: The trunk-elevated side-unsupported task strongly activated the internal (199% maximum voluntary contraction) and external (103%) oblique muscles. The feet-elevated side-supported task strongly activated the internal obliques (205%) but not the external obliques (55%). The lateral plank task successfully activated the internal (107%) and external (72%) obliques, but not at the highest levels of the tested tasks. The side-lying hip abduction task was the least effective at activating either the internal (48%) or external (20%) obliques. CONCLUSIONS: We recommend the novel trunk-elevated side-unsupported task for assessing lateral trunk muscle performance. For independent exercise, we recommend the lateral plank task, unless arm or shoulder pathologies are present, whereby the feet-elevated side-supported task may be favorable.
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Músculos Oblicuos del Abdomen/fisiología , Electromiografía , Ejercicio Físico/fisiología , Contracción Isométrica/fisiología , Adulto , Femenino , Humanos , Masculino , Torso/fisiología , Adulto JovenRESUMEN
BACKGROUND: Carotid stenting stimulates intimal proliferation through platelet and stem cell activation. OBJECTIVE: The aim of this study is to evaluate whether the administration before or after carotid stenting of clopidogrel loading dose may play a role on circulating endothelial progenitor cells, stromal cell-derived factor-1α (SDF-1α) and neointimal hyperplasia. METHODS: We recruited 13 patients (aged 74.52±7.23) with indication of carotid revascularization and in therapy with salicylic acid and statin. We blindly randomized them in two groups: pre-carotid angioplasty with stent (Pre-CAS group) receiving 300âmg of clopidogrel before stenting, and post-carotid angioplasty with stent (Post-CAS group) receiving 300âmg after stenting. At the admission, we valued endothelial progenitor cells, SDF-1α and prospectively we repeated blood samples and measured intima-media thickness to estimate neointimal hyperplasia on the stent at 3, 6 and 12 months. RESULTS: In the days following the CAS, we found a lower, statistically not significant, trend of endothelial progenitor cells in Pre-CAS group. The SDF-1α concentration tended to be lower at baseline in the pre-CAS group than in the post-CAS group and it did not show an increase in the observed time. On the contrary, in the Post-CAS group we observed a peak at six hours with a significant reduction (pâ<â0.001) at one day after stenting.The intima-media thickness was significantly lower in the Pre-CAS group than the Post-CAS group both at six months and 12 months after stenting. CONCLUSIONS: Pre-stenting clopidogrel loading dose leaded to short-time modification of endothelial progenitor cells and platelets and to long-term a minor neointimal hyperplasia.
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Arterias Carótidas/efectos de los fármacos , Estenosis Carotídea/tratamiento farmacológico , Quimiocina CXCL12/metabolismo , Clopidogrel/uso terapéutico , Células Progenitoras Endoteliales/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/uso terapéutico , Anciano , Arterias Carótidas/cirugía , Grosor Intima-Media Carotídeo , Estenosis Carotídea/patología , Clopidogrel/farmacología , Femenino , Humanos , Masculino , Inhibidores de Agregación Plaquetaria/farmacología , Células Madre/fisiología , StentsRESUMEN
Th17 cells have been casually associated to the pathogenesis of autoimmune disease. We have previously demonstrated that Rai/ShcC, a member of the Shc family of adaptor proteins, negatively regulates Th17 cell differentiation and lupus autoimmunity. In this study, we have investigated the pathogenic outcome of the Th17 bias associated with Rai deficiency on multiple sclerosis development, using the experimental autoimmune encephalomyelitis (EAE) mouse model. We found that, unexpectedly, EAE was less severe in Rai(-/-) mice compared with their wild-type counterparts despite an enhanced generation of myelin-specific Th17 cells that infiltrated into the CNS. Nevertheless, when adoptively transferred into immunodeficient Rai(+/+) mice, these cells promoted a more severe disease compared with wild-type encephalitogenic Th17 cells. This paradoxical phenotype was caused by a dampened inflammatory response of astrocytes, which were found to express Rai, to IL-17. The results provide evidence that Rai plays opposite roles in Th17 cell differentiation and astrocyte activation, with the latter dominant over the former in EAE, highlighting this adaptor as a potential novel target for the therapy of multiple sclerosis.
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Astrocitos/inmunología , Encefalomielitis Autoinmune Experimental/inmunología , Proteína Transformadora 3 que Contiene Dominios de Homología 2 de Src/inmunología , Células Th17/inmunología , Animales , Diferenciación Celular/inmunología , Ensayo de Inmunoadsorción Enzimática , Ensayo de Immunospot Ligado a Enzimas , Femenino , Citometría de Flujo , Immunoblotting , Inflamación/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Reacción en Cadena de la PolimerasaRESUMEN
BACKGROUND: Hereditary Coproporphyria (HCP) is characterized by abdominal pain, neurologic symptoms and psychiatric disorders, even if it might remain asymptomatic. The pathophysiology of both neurologic and psychiatric symptoms is not fully understood. Therefore, aiming to evaluate a possible role of brain blood flow disorders, we have retrospectively investigated cerebral perfusion patterns in Single Photon Emission Computed Tomography (SPECT) studies in HCP patients. MATERIALS & METHODS: We retrospectively evaluated the medical records of patients diagnosed as being affected by HCP. A total of seven HCP patients had been submitted to brain perfusion SPECT study with 99mTc-Exametazime (hexamethylpropyleneamine oxime, HMPAO) or with its functionally equivalent 99mTc-Bicisate (ECD or Neurolite) according with common procedures. In 3 patients the scintigraphic study had been repeated for a second time after the first evaluation at 3, 10 and 20 months, respectively. All the studied subjects had been also submitted to an electromyographic and a Magnetic Resonance Imaging (MRI) study of the brain. RESULTS: Mild to moderate perfusion defects were detected in temporal lobes (all 7 patients), frontal lobes (6 patients) and parietal lobes (4 patients). Occipital lobe, basal ganglia and cerebellar involvement were never observed. In the three subjects in which SPECT study was repeated, some recovery of hypo-perfused areas and appearance of new perfusion defects in other brain regions have been found. In all patients electromyography resulted normal and MRI detected few unspecific gliotic lesions only in one patient. Discussion & Conclusions: Since perfusion abnormalities were usually mild to moderate, this can probably explain the normal pattern observed at MRI studies. Compared to MRI, SPECT with 99mTc showed higher sensitivity in HCP patients. Changes observed in HCP patients who had more than one study suggest that transient perfusion defects might be due to a brain artery spasm possibly leading to psychiatric and neurologic symptomatology, as already observed in patients affected by acute intermittent porphyria. This observation, if confirmed by other well designed studies aiming to demonstrate a direct link between artery spasm, perfusion defects and related symptoms could lead to improvements in HCP treatments.
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Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Coproporfiria Hereditaria/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Encéfalo/fisiopatología , Coproporfiria Hereditaria/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto JovenRESUMEN
OBJECTIVE: To investigate the role of CYP2D6 phenotype in the outcome of postoperative (PO) pain (POP) treatment. DESIGN: Longitudinal cohort study. Open-label trial with post hoc analysis. SETTING: General Hospital Surgery and Recovery Units. PATIENTS: Ninety unrelated Caucasians submitted to abdominal/thoracic surgery. INTERVENTIONS: Standard multimodal POP treatment including opioids (tramadol) and nonsteroidal anti-inflammatory drugs (ketoprofen) at different dosages and infusion rates according to the predicted mild, moderate, or severe POP. OUTCOME MEASURES: Pain (Numeric Rating Scale-NRS) and sedation (Ramsay Sedation Scale-RSS) up to 24 hours after surgery. By genotyping 16 CYP2D6 alleles, the four CYP2D6 phenotypes poor metabolizer (PM), intermediate metabolizers (IM), extensive metabolizers (EM) and ultrarapid metabolizers (UM) were predicted. RESULTS: As compared with the CYP2D6-EM phenotype, in the early PO time (30 min) a higher RSS mean score in IM was observed (P = 0.035). A suggestion towards higher mean score in PM (P = 0.091) and a minor mean score in UM (P = 0.091) was also detected. No difference in the outcome of pain across the CYP2D6 phenotypes was observed. CONCLUSIONS: In respect to the normal CYP2D6 phenotype, our results suggested that slowly metabolizers (IMs and PMs) might have a major sedation, whereas more rapid metabolizers (UM) a minor sedation, in the early time after surgery. A minor role of CYP2D6 phenotype in PO analgesia may be suggested.
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Analgésicos/uso terapéutico , Citocromo P-450 CYP2D6/genética , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/genética , Polimorfismo de Nucleótido Simple/genética , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Marcadores Genéticos/genética , Predisposición Genética a la Enfermedad/epidemiología , Predisposición Genética a la Enfermedad/genética , Humanos , Italia/epidemiología , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud/métodos , Dimensión del Dolor/estadística & datos numéricos , Dolor Postoperatorio/epidemiología , Factores de Riesgo , Resultado del Tratamiento , Adulto JovenRESUMEN
The finishing and polishing of composite materials affect the restoration lifespan. The market shows a variety of finishing and polishing procedures and the choice among them is conditioned by different factors such as the resulting surface roughness. In the present study, 156 samples were realized with three composite materials, -microfilled, nanofilled and silorane-, and treated with different finishing and polishing procedures. Profilometric analyses were carried out on the samples' surface, the measured roughness values were submitted to statistical analysis. A complete factorial plan was drawn up and two-way analysis of variance (ANOVA) was carried out to investigate whether the following factors affect the values of roughness: (i) material; (ii) polishing/finishing procedure. Tukey post-hoc test was also conducted to evaluate any statistically significant differences between the material/procedure combinations. The results show that the tested materials do not affect the resulting surface quality but roughness values depend on the finishing/polishing procedure adopted. The procedures that involve: (a) the finishing with medium Sof-Lex discs and (b) the finishing with two tungsten carbide multi-blade milling cutters Q series and UF series are those that allow the lowest values of roughness to be obtained.
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Gluconic acid is produced in large quantities by the endophytic and diazotrophic bacterium Gluconacetobacter diazotrophicus Pal5. This organic acid derives from direct oxidation of glucose by a pyrroloquinoline-quinone-linked glucose dehydrogenase in this plant growth-promoting bacterium. In the present article, evidence is presented showing that gluconic acid is also responsible for the antimicrobial activity of G. diazotrophicus Pal5. The broad antagonistic spectrum includes Gram-positive and -negative bacteria. Eukaryotic microorganisms are more resistant to growth inhibition by this acid. Inhibition by gluconic acid can be modified through the presence of other organic acids. In contrast to other microorganisms, the Quorum Sensing system of G. diazotrophicus Pal5, a regulatory mechanism that plays a key role in several microbe-microbe interactions, is not related to gluconic acid production and the concomitant antagonistic activity.
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Antiinfecciosos/metabolismo , Antiinfecciosos/farmacología , Gluconacetobacter/metabolismo , Gluconatos/metabolismo , Gluconatos/farmacología , Eucariontes/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Pruebas de Sensibilidad MicrobianaRESUMEN
Rai, a Shc adapter family member, acts as a negative regulator of antigen receptor signaling in T and B cells. Rai(-/-) mice develop lupus-like autoimmunity associated to the spontaneous activation of self-reactive lymphocytes. Here, we have addressed the potential role of Rai in the development of the proinflammatory Th1 and Th17 subsets, which are centrally implicated in the pathogenesis of a number of autoimmune diseases, including lupus. We show that Rai(-/-) mice display a spontaneous Th1/Th17 bias. In vitro polarization experiments on naive and effector/memory CD4(+) T cells demonstrate that Rai(-/-) favors the development and expansion of Th17 but not Th1 cells, indicating that Rai modulates TCR signaling to antagonize the pathways driving naive CD4(+) T cell differentiation to the Th17 lineage, while indirectly limiting Th1 cell development in vivo. Th1 and Th17 cell infiltrates were found in the kidneys of Rai(-/-) mice, providing evidence that Rai(-/-) contributes to the development of lupus nephritis, not only by enhancing lymphocyte activation but also by promoting the development and expansion of proinflammatory effector T cells. Interestingly, T cells from SLE patients were found to have a defect in Rai expression, suggesting a role for Rai in disease pathogenesis.