The Bradyrhizobium Sp. LmicA16 Type VI Secretion System Is Required for Efficient Nodulation of Lupinus Spp.

Many bacteria of the genus Bradyrhizobium are capable of inducing nodules in legumes. In this work, the importance of a type VI secretion system (T6SS) in a symbiotic strain of the genus Bradyrhizobium is described. T6SS of Bradyrhizobium sp. LmicA16 (A16) is necessary for efficient nodulation with Lupinus micranthus and Lupinus angustifolius. A mutant in the gene vgrG, coding for a component of the T6SS nanostructure, induced less nodules and smaller plants than the wild-type (wt) strain and was less competitive when co-inoculated with the wt strain. A16 T6SS genes are organized in a 26-kb DNA region in two divergent gene clusters of nine genes each. One of these genes codes for a protein (Tsb1) of unknown function but containing a methyltransferase domain. A tsb1 mutant showed an intermediate symbiotic phenotype regarding vgrG mutant and higher mucoidity than the wt strain in free-living conditions. T6SS promoter fusions to the lacZ reporter indicate expression in nodules but not in free-living cells grown in different media and conditions. The analysis of nodule structure revealed that the level of nodule colonization was significantly reduced in the mutants with respect to the wt strain.

Ultrasound as a diagnostic and management tool in hidradenitis suppurativa patients: a multicentre study.

BACKGROUND: It has been reported that clinical evaluation consistently underestimates the severity of hidradenitis suppurativa (HS). OBJECTIVE: To determine the usefulness of ultrasound as a diagnostic tool in HS compared with clinical examination and to assess the subsequent modification of disease management. METHODS: Cross-sectional multicentre study. Severity classification and therapeutic approach according to clinical vs. ultrasound examination were compared. RESULTS: Of 143 HS patients were included. Clinical examination scored 38, 70 and 35 patients as Hurley stage I, II and III, respectively; with ultrasound examination, 21, 80 and 42 patients were staged with Hurley stage I, II and III disease, respectively (P < 0.01). In patients with stage I classification as determined by clinical examination, 44.7% changed to a more severe stage. Clinical examination indicated that 44.1%, 54.5% and 1.4% of patients would maintain, increase or decrease treatment, respectively. For ultrasound examination, these percentages were 31.5%, 67.1% and 1.4% (P < 0.01). Concordance between clinical and ultrasound intra-rater examination was 22.8% (P < 0.01); intra-rater and inter-rater (radiologist) ultrasound agreement was 94.9% and 81.7%, respectively (P < 0.01). LIMITATIONS: The inability to detect lesions that measure ≤0.1 mm or with only epidermal location. CONCLUSION: Ultrasound can modify the clinical staging and therapeutic management in HS by detecting subclinical disease.

[Ultrasound examination of hidradenitis suppurativa]. / Ecografía de la hidradenitis supurativa.

Hidradenitis suppurativa is a debilitating chronic, recurrent, inflammatory cutaneous disease of the hair follicle that usually presents with painful, deep and inflamed lesions in the areas of the body with apocrine glands, most frequently the axillary, groin and anogenital regions. This entity is difficult to manage since it can be difficult to determine the true nature and extension of the lesions. Cutaneous ultrasound allows real-time visualization of the cutaneous structures under examination, defining the type of lesion, its anatomical extension, and the degree of inflammatory activity, which affects adequate patient management. The present review analyses the importance of ultrasound in the assessment of patients with hidradenitis suppurativa.

[Ultrasound in the management of inflammatory dermatosis]. / Ecografía aplicada al manejo de las dermatosis inflamatorias.

Cutaneous ultrasound is a dermatological diagnostic imaging technique based on the interaction of high-frequency ultrasounds with the skin. Because it is non-invasive, rapid and accessible, it has increasingly wide clinical applications. This article reviews its use in the management of inflammatory dermatological diseases.

Functional and expression analysis of the metal-inducible dmeRF system from Rhizobium leguminosarum bv. viciae.

A gene encoding a homolog to the cation diffusion facilitator protein DmeF from Cupriavidus metallidurans has been identified in the genome of Rhizobium leguminosarum UPM791. The R. leguminosarum dmeF gene is located downstream of an open reading frame (designated dmeR) encoding a protein homologous to the nickel- and cobalt-responsive transcriptional regulator RcnR from Escherichia coli. Analysis of gene expression showed that the R. leguminosarum dmeRF genes are organized as a transcriptional unit whose expression is strongly induced by nickel and cobalt ions, likely by alleviating the repressor activity of DmeR on dmeRF transcription. An R. leguminosarum dmeRF mutant strain displayed increased sensitivity to Co(II) and Ni(II), whereas no alterations of its resistance to Cd(II), Cu(II), or Zn(II) were observed. A decrease of symbiotic performance was observed when pea plants inoculated with an R. leguminosarum dmeRF deletion mutant strain were grown in the presence of high concentrations of nickel and cobalt. The same mutant induced significantly lower activity levels of NiFe hydrogenase in microaerobic cultures. These results indicate that the R. leguminosarum DmeRF system is a metal-responsive efflux mechanism acting as a key element for metal homeostasis in R. leguminosarum under free-living and symbiotic conditions. The presence of similar dmeRF gene clusters in other Rhizobiaceae suggests that the dmeRF system is a conserved mechanism for metal tolerance in legume endosymbiotic bacteria.

Dermatofibromas treated with pulsed dye laser: Clinical and dermoscopic outcomes.

Dermatofibroma (DF), a common benign skin tumour, sometimes requires treatment either because of cosmetic concern or for associated symptoms. However, no effective treatment with optimal cosmetic outcomes has been reported. An effective and safe therapeutic option could be treatment with pulsed dye laser (PDL). Twenty-two DFs in 15 patients were treated with PDL at 595-nm wavelength, using a spot size of 7 mm, a pulse duration of 2 ms and a fluence of 11 J/cm(2) with 2 or 3 stacked pulses. Clinical and dermoscopic photographs were taken before and after therapy. Global clinical improvement was higher than 50% in 12 lesions. Patient satisfaction assessment showed 73% of patients as satisfied or very satisfied. All lesions showed changes from the previous dermoscopic pattern. We consider that PDL could be a safe, palliative treatment as it is well accepted by patients and has a better cosmetic outcome than surgical excision.

Beta-adrenergic-receptor localization by light microscopic autoradiography.

beta-Receptors were identified in rat brain by a light microscopic autoradiographic technique. The procedure involved binding 3H-labeled dihydroalprenolol to beta-receptors in intact slide-mounted tissue sections and generating autoradiograms by the apposition of emulsion-coated cover slips, Biochemical analysis of the binding indicated that these conditions provided a high degree of selective labeling of beta-receptors. High densities of receptors were found in superficial layers of the cerebral cortex, throughout the caudate-putamen, in the periventricular nucleus of the thalamus, in the molecular layer of the cerebellum, and in other areas. These results are in agreement with other electrophysiological and histochemical data. This radiohistochemical approach should be an important addition to other methods for mapping functional catecholamine neuronal pathways and sites of hormonal action.

Characterization of carbon nanofibers grown over Ni and Ni-cu catalysts.

Carbon nanofibers were obtained by thermo-catalytic decomposition of methane at 700 degrees C over Ni and Ni-Cu catalysts prepared by different methods (co-precipitation, impregnation and fusion) and using either Al or Mg as textural promoter. Characterization of the carbon thus obtained was performed by N2 adsorption isotherms (BET surface area), temperature programmed desorption (TPD), temperature programmed oxidation (TPO), X-ray diffraction, Raman spectrometry, and electron microscopy SEM and TEM. The carbon obtained possesses high crystallinity and poor surface chemistry. The crystallinity is enhanced when using Mg as textural promoter and in the presence of copper. SEM and TEM examinations show that the fibers have fishbone structure and they grow generally from one nickel particle (tip growing) although there are some bidirectional growing. Copper-doping lead to the formation of thicker filaments and promotes the formation of bamboo-like structures. Catalyst particles higher than 100 nm do not promote the formation of nanofibers and the carbon deposits as uniform coatings.

[Primary cardiac tumours in infancy]. / Tumores cardíacos primarios en la infancia.

INTRODUCTION: Primary cardiac tumours are very rare in the paediatric age, their incidence varies from 0.0017 % to 0.28 %. More than 90 % are benign in nature. The most common variety is the rhabdomyoma, present in over 60 % of cases with tuberous sclerosis. MATERIAL AND METHODS: We performed a retrospective analysis of medical records with a diagnosis of primary cardiac tumor between March 1977 and March 2007, finding a total of 27 patients. RESULTS: The age of initial diagnosis is more prevalent in the neonatal period, beginning with the discovery of a heart murmur (11 cases). There was no difference in gender distribution. In 14 patients were found cardiomegaly on chest radiograph. According to the echocardiography characteristics there were diagnosed 20 rhabdomyomas, 2 fibromas, 2 pericardial teratomas and 3 non classifiable tumours. Most were located in the left ventricle. Echocardiography, cardiac catheterization was also performed in 3 cases and angioresonance in 5 cases. During their evolution, episodes of arrhythmias were observed in 11 patients, 5 patients required some sort of surgical procedure, which confirmed the histopathology diagnosis. In 3 patients the initial cause of death was cardiological. The 75 % of cases with rhabdomyomas presented or developed tuberous sclerosis. In most of the rhabdomyomas (13 cases), there was a spontaneous regression. CONCLUSIONS: Firstly, there is shown to be a low prevalence of this disorder in children. Rhabdomyoma is the most common primary cardiac tumour in our study and it was associated in 75 % of cases with tuberous sclerosis. The diagnosis is more common in the early neonatal period after auscultation of a cardiac murmur and echocardiography, the diagnostic technique of choice, other imaging techniques, such as angioMRI not being of much for diagnosis in children. The emergence of foetal echocardiography allows early detection. The course is benign in most tumours, rhabdomyomas tending to regress spontaneously. It must be monitored as the occurrence of arrhythmias during its evolution will require medical treatment. Surgery is needed in cases with severe symptoms, due to obstruction in the ventricular output tracts. One option is the surgical cardiac transplant in non-resectable life-threatening tumours.

Receptor visualization and the atomic bomb. A historical account of the development of the chemical neuroanatomy of receptors for neurotransmitters and drugs during the Cold War.

This is a historical account of how receptors for neurotransmitters and drugs got to be seen at the regional, cellular, and subcellular levels in brain, in the years going from the end of the World War II until the collapse of the Soviet Union, the Cold War (1945-1991). The realization in the US of the problem of mental health care, as a consequence of the results of medical evaluation for military service during the war, let the US Government to act creating among other things the National Institute for Mental Health (NIMH). Coincident with that, new drug treatments for these disorders were introduced. War science also created an important number of tools and instruments, such as the radioisotopes, that played a significant role in the development of our story. The scientific context was marked by the development of Biochemistry, Molecular Biology and the introduction in the early 80's of the DNA recombinant technologies. The concepts of chemical neurotransmission in the brain and of receptors for drugs and transmitters, although proposed before the war, where not generally accepted. Neurotransmitters were identified and the mechanisms of biosynthesis, storage, release and termination of action by mechanisms such as reuptake, elucidated. Furthermore, the synapse was seen with the electron microscope and more important for our account, neurons and their processes visualized in the brain first by fluorescence histochemistry, then using radioisotopes and autoradiography, and later by immunohistochemistry (IHC), originating the Chemical Neuroanatomy. The concept of chemical neurotransmission evolved from the amines, expanded to excitatory and inhibitory amino acids, then to neuropeptides and finally to gases and other "atypical" neurotransmitters. In addition, coexpression of more than one transmitter in a neuron, changed the initial ideas of neurotransmission. The concept of receptors for these and other messengers underwent a significant evolution from an abstract chemical concept to their physical reality as gene products. Important steps were the introduction in the 70's of radioligand binding techniques and the cloning of receptor genes in the 80's. Receptors were first visualized using radioligands and autoradiography, and analyzed with the newly developed computer-assisted image analysis systems. Using Positron Emission Tomography transmitters and receptors were visualized in living human brain. The cloning of receptor genes allowed the use of in situ hybridization histochemistry and immunohistochemistry to visualize with the light and electron microscopes the receptor mRNAs and proteins. The results showed the wide heterogeneity of receptors and the diversity of mode of signal transmission, synaptic and extra-synaptic, again radically modifying the early views of neurotransmission. During the entire period the interplay between basic science and Psychopharmacology and Psychiatry generated different transmitter or receptor-based theories of brain drug action. These concepts and technologies also changed the way new drugs were discovered and developed. At the end of the period, a number of declines in these theories, the use of certain tools and the ability to generate new diagnostics and treatments, the end of an era and the beginning of a new one in the research of how the brain functions.

Calcium modulates interactions between bacteria and hydroxyapatite.

Bacterial adhesion onto hydroxyapatite is known to depend on the surface properties of both the biomaterial and the bacterial strain, but less is known about the influence of the composition of the aqueous medium. Here, the adhesion of Streptococcus mutans and 3 different Lactobacilli on powdered hydroxyapatite was shown to change with Ca2+ concentration. The effect depends on the surface properties of each strain. Adhesion of Lactobacillus fermentum and salivarius (and of Streptococcus mutans at low Ca2+) was enhanced with increasing Ca2+ concentration. Lactobacillus casei was efficiently removed by adhesion on hydroxyapatite, even without Ca2+ addition, and the effect of this ion was only marginal. The results are interpreted in terms of Ca2+-mediated adhesion, and relative to the hydrophobic properties of each strain and the electrical properties of the bacterial and solid surfaces (electrophoretic mobility).

Inhibition of enteropathogens adhesion to human enterocyte-like HT-29 cells by a dairy strain of Propionibacterium acidipropionici.

Adhesion to the host intestinal mucosa is considered relevant for orally delivered probiotics as it prolongs their persistence in the gut and their health promoting effects. Classical propionibacteria are microorganisms of interest due to their role as dairy starters as well as for their functions as probiotics. Propionibacterium acidipropionici Q4, is a dairy strain isolated from a Swiss-type cheese made in Argentina that displays probiotic potential. In the present work we assessed the ability of this strain to adhere to the human enterocyte-like HT-29 cell line and to counteract the adhesion of two common human enteropathogens, such as Escherichia coli C3 and Salmonella Enteritidis 90/390. The results were compared with those obtained with the well-known probiotic Lactobacillus rhamnosus GG. P. acidipropionici Q4 showed a high adhesion capacity, even higher than the reference strain L. rhamnosus GG (42.3±4.4% and 36.2±2.3%, respectively), whereas adhesion of enteropathogens was significantly lower (25.2±2.2% for E. coli and 21.0±3.4% for S. Enteritidis). Propionibacteria as well as lactobacilli were able to inhibit by exclusion and competition the adherence of E. coli C3 and S. Enteritidis 90/390 whereas only L. rhamnosus GG displaced S. Enteritidis from HT-29 intestinal cells. Inhibition of pathogens by propionibacteria was not exerted by antimicrobials or coaggregation but was mainly due to exclusion by cell surface components, such as proteins and carbohydrates. The relevance of cell surface proteins (CSP) for preventing pathogens infection was confirmed by their concentration dependent effect observed for both pathogens: 100 µg/ml of CSP inhibited E. coli attachment almost as untreated propionibacteria, whereas it partially inhibited the attachment of S. Enteritidis. Results suggest that P. acidipropionici Q4 could be considered for the development of propionibacteria containing functional foods helpful in counteracting enteropathogen infection.