Organothiol Monolayer Formation Directly on Muscovite Mica.

Organothiol monolayers on metal substrates (Au, Ag, Cu) and their use in a wide variety of applications have been extensively studied. Here, the growth of layers of organothiols directly onto muscovite mica is demonstrated using a simple procedure. Atomic force microscopy, surface X-ray diffraction, and vibrational sum-frequency generation IR spectroscopy studies revealed that organothiols with various functional endgroups could be self-assembled into (water) stable and adaptable ultra-flat organothiol monolayers over homogenous areas as large as 1 cm2 . The strength of the mica-organothiol interactions could be tuned by exchanging the potassium surface ions for copper ions. Several of these organothiol monolayers were subsequently used as a template for calcite growth.

The structure of PbCl2 on the {100} surface of NaCl and its consequences for crystal growth.

The role that additives play in the growth of sodium chloride is a topic which has been widely researched but not always fully understood at an atomic level. Lead chloride (PbCl2) is one such additive which has been reported to have growth inhibition effects on NaCl {100} and {111}; however, no definitive evidence has been reported which details the mechanism of this interaction. In this investigation, we used the technique of surface x-ray diffraction to determine the interaction between PbCl2 and NaCl {100} and the structure at the surface. We find that Pb2+ replaces a surface Na+ ion, while a Cl- ion is located on top of the Pb2+. This leads to a charge mismatch in the bulk crystal, which, as energetically unfavourable, leads to a growth blocking effect. While this is a similar mechanism as in the anticaking agent ferrocyanide, the effect of PbCl2 is much weaker, most likely due to the fact that the Pb2+ ion can more easily desorb. Moreover, PbCl2 has an even stronger effect on NaCl {111}.

Achromatic synesthesias - a functional magnetic resonance imaging study.

Grapheme-color synesthetes experience consistent, automatic and idiosyncratic colors associated with specific letters and numbers. Frequently, these specific associations exhibit achromatic synesthetic qualities (e.g. white, black or gray). In this study, we have investigated for the first time the neural basis of achromatic synesthesias, their relationship to chromatic synesthesias and the achromatic congruency effect in order to understand not only synesthetic color but also other components of the synesthetic experience. To achieve this aim, functional magnetic resonance imaging experiments were performed in a group of associator grapheme-color synesthetes and matched controls who were stimulated with real chromatic and achromatic stimuli (Mondrians), and with letters and numbers that elicited different types of grapheme-color synesthesias (i.e. chromatic and achromatic inducers which elicited chromatic but also achromatic synesthesias, as well as congruent and incongruent ones). The information derived from the analysis of Mondrians and chromatic/achromatic synesthesias suggests that real and synesthetic colors/achromaticity do not fully share neural mechanisms. The whole-brain analysis of BOLD signals in response to the complete set of synesthetic inducers revealed that the functional peculiarities of the synesthetic brain are distributed, and reflect different components of the synesthetic experience: a perceptual component, an (attentional) feature binding component, and an emotional component. Additionally, the inclusion of achromatic experiences has provided new evidence in favor of the emotional binding theory, a line of interpretation which constitutes a bridge between grapheme-color synesthesia and other developmental modalities of the phenomenon.

Self-recognition of CD1 by gamma/delta T cells: implications for innate immunity.

The specificity of immunoglobulins and alpha/beta T cell receptors (TCRs) provides a framework for the molecular basis of antigen recognition. Yet, evolution has preserved a separate lineage of gamma/delta antigen receptors that share characteristics of both immunoglobulins and alpha/beta TCRs but whose antigens remain poorly understood. We now show that T cells of the major tissue gamma/delta T cell subset recognize nonpolymorphic CD1c molecules. These T cells proliferated in response to CD1+ presenter cells, lysed CD1c+ targets, and released T helper type 1 (Th1) cytokines. The CD1c-reactive gamma/delta T cells were cytotoxic and used both perforin- and Fas-mediated cytotoxicity. Moreover, they produced granulysin, an important antimicrobial protein. Recognition of CD1c was TCR mediated, as recognition was transferred by transfection of the gamma/delta TCR. Importantly, all CD1c-reactive gamma/delta T cells express V delta 1 TCRs, the TCR expressed by most tissue gamma/delta T cells. Recognition by this tissue pool of gamma/delta T cells provides the human immune system with the capacity to respond rapidly to nonpolymorphic molecules on professional antigen presenting cells (APCs) in the absence of foreign antigens that may activate or eliminate the APCs. The presence of bactericidal granulysin suggests these cells may directly mediate host defense even before foreign antigen-specific T cells have differentiated.

An antimicrobial activity of cytolytic T cells mediated by granulysin.

Cytolytic T lymphocytes (CTLs) kill intracellular pathogens by a granule-dependent mechanism. Granulysin, a protein found in granules of CTLs, reduced the viability of a broad spectrum of pathogenic bacteria, fungi, and parasites in vitro. Granulysin directly killed extracellular Mycobacterium tuberculosis, altering the membrane integrity of the bacillus, and, in combination with perforin, decreased the viability of intracellular M. tuberculosis. The ability of CTLs to kill intracellular M. tuberculosis was dependent on the presence of granulysin in cytotoxic granules, defining a mechanism by which T cells directly contribute to immunity against intracellular pathogens.

Additive Induced Formation of Ultrathin Sodium Chloride Needle Crystals.

A multitude of ultrathin crystal needles are formed during the evaporation of saturated aqueous NaCl solution droplets in the presence of amide containing additives. The needles are as small as 300 nm wide and 100-1000 µm in length. Heating experiments, X-ray diffraction, and energy dispersive X-ray spectroscopy showed that the needles are cubic sodium chloride crystals with the needle length direction pointing toward [100]. This shape, not expected for the 43̅m point group symmetry of NaCl, has been explained using a model, based on tip formation by initial morphological instability followed by time dependent adsorption of additive molecules blocking the growth of the needle side faces. The latter also suppresses side branch formation, which normally occurs for dendrite growth.

Antigen presentation by CD1 and MHC-encoded class I-like molecules.

Three known lineages of antigen-presenting molecules restrict T-cell responses to microbial antigens: MHC class I and MHC encoded class I like molecules present peptides derived from the proteolysis of intracellular pathogens, MHC class ii molecules present peptides derived from the proteolysis of extracellular pathogens and CD1 molecules present unique microbial lipids and glycolipids. Recent studies have indicated that CD1 molecules mediate a novel system of antigen presentation and that MHC-encoded class I-like molecules can present unique subsets of intracellularly derived peptides.

[Posterior urethral valves, unilateral vesicoureteral reflux and renal dysplasia (VURD syndrome). Long-term follow-up of kidney function]. / Válvulas de uretra posterior, reflujo vesicoureteral unilateral y displasia renal (síndrome VURD). Seguimiento de la función renal a largo plazo.

Posterior urethral valves, unilateral vesicoureteral reflux and renal dysplasia (VURD syndrome) is an infrequent entity in childhood that has provoked multiple controversies. The shortage of studies that evaluate the long-term outcome in these children prompted up to write the present article. Three patients that met strict criteria for a diagnosis of VURD syndrome were retrospectively reviewed, with special emphasis on several indicators of renal function in these patients at diagnosis and in adulthood. The three patients currently have normal renal function, unlike a large percentage of patients diagnosed with posterior urethral valves with vesicoureteral bilateral reflux. Although the sample is small, our results support the hypothesis of good long-term renal function in affected children.

Dynamic restricted expression of the chaperone Hsc70 in early chick development.

The non-inducible chaperone heat shock cognate 70 kDa (Hsc70) is regulated during development. We now characterize its dynamic expression pattern from gastrulation to early organogenesis. Throughout this developmental period, hsc70 transcripts were largely restricted to neuroectoderm- and mesoderm-derived structures. In stage 10 embryos, Hsc70 protein was expressed in the neural tube with increasing rostrocaudal and decreasing dorsoventral gradients, and in some somite cells. This highly regulated expression of Hsc70 is likely to reflect specific developmental functions, besides its well-characterized role in protein folding.

Lectin-binding patterns in the development of the cerebellum.

We studied the binding distribution of several lectins, Con A, DBA, UEA and WGA, in the embryonic development of the chick cerebellum between stages 18 to 45 of Hamburger and Hamilton. We observed a differential labeling (in intensity and distribution) in the migratory and cortical layers of the cerebellum anlage with these different lectins. The different distributions and modifications in the labeling pattern suggest intense variations of the glycoproteins and glycosaminoglycans in the extracellular matrix during development. These variations coincide with cellular and organizational phenomena in the migratory and cortical layers, and suggest compartmentalization of the Purkinje cell labeling.

The ontogeny of the cerebellar fissures in the chick embryo.

We have studied the chronology of appearance and the cortical changes which precede the fissures appearing between stages 34 to 40. In this paper we demonstrate the structural modifications of the cerebellar cortex defined as the anlagen of the fissures. The anlage of a fissure begins in a well-determined place of the cerebellar cortex. It begins with a thickening of the internal cortical cell layer, which finally folds. These modifications precede other similar ones which occur in the overlying external granular layer. On the other hand, these cortical structural modifications precede the transversal projection of the fissures. Chronological order of appearance of the anlagen of the fissures, related to the appearance of fissures on the surface of the cerebellum is also given.

[The role of molecular genetics in childhood cancer]. / Papel de la genética molecular en el cáncer infantil.

In the last few years molecular genetic studies of childhood cancer have acquired great importance. Advances in these techniques have increased knowledge of the various genes involved in tumoral development. Genetic alterations can occur in three large groups of genes: oncogenes, tumor suppressor genes, and DNA repair genes. Cytogenetic analyses (karyotyping) are complemented by various molecular techniques, such as fluorescence in situ hybridization (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR) and spectral karyotyping (SKY). These are the most reliable techniques and improve the sensitivity of karyotyping. The present article reviews the most representative and best characterized genes involved in the molecular etiology of childhood cancer, both hematologic malignancies (leukemia and lymphoma) and solid tumors (brain tumors, neuroblastoma, Wilms' tumor, hepatoblastoma, rhabdomyosarcoma, Ewing's sarcoma and retinoblastoma). Molecular techniques have enabled more precise diagnosis as well as identification of new prognostic factors and the development of more effective treatments. These techniques can also be useful in identifying minimal residual disease during and after treatment for leukemias, neuroblastomas and sarcomas, with the aim of predicting recurrence.

[Neonatal convulsions of a familial character and with a benign prognosis. Nosological classification. Apropos of a new case]. / Convulsiones neonatales con carácter familiar y pronóstico benigno. Encuadre nosológico. A propósito de una nueva observación.

A new familial observation (3 members affected) of neonatal seizures without C. N. S. nor methabolic disturbance and subsequent normal development is reported. Seven other observations have been published before. The characteristics of this syndrome are discussed.

[Hospital admissions due to whooping cough: experience of the del niño hospital in Panama. Period 2001-2008]. / Hospitalizaciones por Bordetella pertussis: experiencia del Hospital del Niño de Panamá, periodo 2001-2008.

INTRODUCTION: Bordetella pertussis (whooping cough) is a worldwide public health problem. It is estimated that there are about 20 to 40 million cases with 200,000-400,000 deaths and is increasing in infants and adults. MATERIALS AND METHODS: An observational, retrospective study was made. We reviewed the epidemiologic surveillance notification forms from 2001 to 2008 period at the Epidemiology Department of Hospital Del Niño, a tertiary paediatric reference centre in Panama City. All pertussis (whooping cough) cases confirmed by PCR and cultures were selected. RESULTS: From a total of 759 notifications of suspected whooping cough cases, 180 confirmed cases using PCR and culture were analyzed for this study. The admission rate in all ages was 14.4/10,000 admissions, predominantly in < or =3 months with 42.76/10,000 admissions and which accounted for 75% of the cases. Cough was the most important symptom (91%). Cyanosis, leucocytosis and lymphocytosis were the most characteristic clinical findings when comparing positive pertussis with negative. More than two thirds of the subjects less than 3 months of age had not been vaccinated at the time of admission. The death rate was 8.3%, more than half of them in subjects less than 1 month of age. CONCLUSIONS: Whooping cough is an important public health problem. Post-partum vaccination could be a strategy to reduce morbidity and mortality in infants less than 3 months of age.

Expression of TGF-betas in the embryonic nervous system: analysis of interbalance between isoforms.

Transforming growth factor-beta (TGF-beta) is a family of growth factors with essential and multiple roles during embryonic development. In mammals, three isoforms (TGF-beta1, TGF-beta2, TGF-beta3) have been described. In the nervous system, the presence of TGF-beta1 has remained undetectable in other structures than meninges and choroids plexus, while TGF-beta2 and TGF-beta3 were considered as the neural members of the family. In the present study, we have analysed the expression pattern of the three isoforms in the neural tube, brain, and spinal cord during development in both mouse and chicken. The data reveal specific patterns for each isoform. This work also shows that both TGF-beta1 and TGF-beta3 are expressed in neural crest cells. In addition, we demonstrate the existence of interbalance between TGF-beta1 and TGF-beta3 with possible functional implications, which, together with the expression of TGF-beta1 in the CNS, represents one of the most important contributions of this work.

Efficacy of cyclo-oxygenase-2 inhibition by etoricoxib and naproxen on the axial manifestations of ankylosing spondylitis in the presence of peripheral arthritis.

OBJECTIVE: The combined efficacy of selective and non-selective cyclo-oxygenase-2 (COX-2) inhibition on the axial manifestations of ankylosing spondylitis (AS) in the presence or absence of chronic peripheral arthritis was evaluated. METHODS: In a post hoc subgroup analysis of a 6 week, randomised, double blind, placebo controlled trial, 387 patients with active axial AS were randomised to receive etoricoxib 90 mg or 120 mg once a day, naproxen 500 mg twice daily, or placebo. Randomisation was stratified by the presence or absence of chronic peripheral arthritis. The primary outcome measure was the time weighted average change from baseline of spine pain intensity. Efficacy data from the three groups receiving active treatment (the NSAID/COX-2 inhibitor group) were combined to improve precision. An analysis of covariance model was used to evaluate the effect of peripheral disease on treatment response. RESULTS: 93 patients were allocated to receive placebo and 294 to active treatment (naproxen or etoricoxib). The combined NSAID/COX-2 inhibitor group had a significant treatment response compared with the placebo group for all efficacy measures, both in patients with and without peripheral arthritis. A significantly greater difference in mean patient assessment of spine pain was found between active and placebo treatments in patients without compared with those with peripheral arthritis (p = 0.005; -32.5 mm v -17.0 mm, respectively). Similar differences, although not statistically significant, were seen for other end points. CONCLUSION: NSAIDs and COX-2 inhibitors have a clinically relevant symptomatic effect on axial AS irrespective of the presence of peripheral arthritis. In this exploratory analysis spinal improvement appeared to be greater in patients without peripheral disease.