Fluticasone in mild to moderate atopic dermatitis relapse: A randomized controlled trial.

BACKGROUND: The long-term efficacy of corticosteroids to prevent atopic dermatitis (AD) relapses has partially been addressed in children. This study compared an intermittent dosing regimen of fluticasone propionate (FP) cream 0.05% with its vehicle base in reducing the risk of relapse in children with stabilized AD. METHODS: A randomized controlled, multicentric, double-blind trial was conducted. Children (2-10 years) with mild/moderate AD (exclusion criteria: >30% affected body surface area and/or head) were enrolled into an Open-label Stabilization Phase (OSP) of up to 2 weeks on twice daily FP. Those who achieved treatment success entered the Double-blind Maintenance Phase (DMP). They were randomly allocated to receive FP or vehicle twice-weekly on consecutive days for 16 weeks. The primary study endpoint was relapse rate; time to relapse and severity of disease were also studied. Kaplan-Meier estimates were calculated. RESULTS: Fifty-four patients (29 girls) entered the OSP (23 mild AD) and 49 (26 girls) continued into the DMP. Mean age was 5.5 (SD: 2.8) and 5.1 (SD: 2.3) yrs for FP and vehicle groups, respectively. Four patients withdrew from the DMP (two in every group). Patients treated with FP twice weekly had a 2.7 fold lower risk of experiencing a relapse than patients treated with vehicle (relative risk 2.72, SD: 1.28; p=0.034). FP was also superior to vehicle for delaying time to relapse. Both treatment therapies were well tolerated. CONCLUSION: This long-term study shows that twice weekly FP provides an effective maintenance treatment to control the risk of relapse in children with AD.

[Complete and inverted esophagastric duplicity]. / Duplicidad esofagogástrica completa e invertida.

CASE REPORT: A 4-month old girl affected by gastric duplication discovered as a palpable abdominal mass displacing the spleen and left kidney. During laparotomy, a yellowish secretion is aspirated and the gastric duplication is excised together with the common muscular Wall of the greater curvature of the stomach. Also excised, a tubular structure starting from the inferior pole of the malformation, and communicating with it, passing superior to the head of the pancreas and the second portion of the duodenum, followed by a posterior course before inserting into the right cruz of the diaphragm. The histology of the tubular formation was compatible with esophagus. CONCLUSION: This type of duplication has not been reported in the literature and reinforces the theory that these malformations could be secondary to genetic transcription errors, in the differentiation of the endoderm of the primitive digestive tract and the notochord.

CASO CLINICO: Niña de 4 meses, afecta de una duplicidad gástrica, descubierta como masa abdominal palpable y que desplazaba el bazo y el riñón izquierdo. Mediante laparotomía, se observa una duplicidad gástrica y, tras aspirar una secreción amarillenta, se realiza su exéresis junto con la pared muscular común con la curvatura mayor del estómago y una estructura tubular que, partiendo del polo inferior de la malformación y comunicada con ella, pasaba por encima de la cabeza del páncreas y de la segunda porción duodenal, siguiendo luego un curso posterior hasta insertarse en la base del pilar diafragmático derecho. La histología de esta formación tubular fue compatible con el esófago. CONCLUSIONES: Este tipo de duplicidad no la hemos visto referida en la literatura y refuerza la teoría de que estas malformaciones pudieran ser secundarias a errores de transcripción genéticas de información en la diferenciación del endodermo del tubo digestivo primitivo y de la notocorda.

The partial labyrinthectomy petrous apicectomy approach to petroclival meningiomas. A quantitative anatomic comparison with other approaches to the same region.

The partial labyrinthectomy petrous apicectomy (PLPA) approach is a transpetrous route that provides the advantages of the labyrinthine removal but with hearing preservation. Using seven temporal bone tissue blocks and three formaldehyde-fixed cadaveric heads we have made a morphometric and comparative study on this approach that summarizes the invasiveness, the optimal surgical exposure, the anatomic complexity of the skull base approaches and, on the other hand, the spirit of preservation that is the constant aim of modern neurosurgery. The morphometric analysis is designed to make the bony phase of the PLPA approach safer and to define the relationship between petrous landmarks. The comparative study is made between the PLPA and other neurosurgical routes enhancing the potentiality of the PLPA approach that permits a wider angle of incidence towards the brainstem than with the retrosigmoid routes.

High expression of cytochrome b 5 reductase isoform 3/cytochrome b 5 system in the cerebellum and pyramidal neurons of adult rat brain.

Cytochrome b 5 reductase (Cb 5R) and cytochrome b 5 (Cb 5) form an enzymatic redox system that plays many roles in mammalian cells. In the last 15 years, it has been proposed that this system is involved in the recycling of ascorbate, a vital antioxidant molecule in the brain and that its deregulation can lead to the production of reactive oxygen species that play a major role in oxidative-induced neuronal death. In this work, we have performed a regional and cellular distribution study of the expression of this redox system in adult rat brain by anti-Cb 5R isoform 3 and anti-Cb 5 antibodies. We found high expression levels in cerebellar cortex, labeling heavily granule neurons and Purkinje cells, and in structures such as the fastigial, interposed and dentate cerebellar nuclei. A large part of Cb 5R isoform 3 in the cerebellum cortex was regionalized in close proximity to the lipid raft-like nanodomains, labeled with cholera toxin B, as we have shown by fluorescence resonance energy transfer imaging. In addition, vestibular, reticular and motor nuclei located at the brain stem level and pyramidal neurons of somatomotor areas of the brain cortex and of the hippocampus have been also found to display high expression levels of these proteins. All these results point out the enrichment of Cb 5R isoform 3/Cb 5 system in neuronal cells and structures of the cerebellum and brain stem whose functional impairment can account for neurological deficits reported in type II congenital methemoglobinemia, as well as in brain areas highly prone to undergo oxidative stress-induced neurodegeneration.

Targeted over-expression of FGF in chick embryos induces formation of ectopic neural cells.

Fibroblast growth factors (FGFs) are known to be involved mainly in mesoderm formation in Xenopus embryos but their participation in other inductive mechanisms such as neural induction has not been clearly established and is now under study. Here, we provide evidence that targeted over-expression of members of this family of growth factors in the periphery of full-length primitive streak chick embryos produces the formation of ectopic neural cells that are able to differentiate into neurons. The supernumerary neural plate obtained derives from the epiblast layer of the blastoderm and show signs of neural differentiation 24 h after the application of FGF. We have used cell labeling and have examined the expression of mesodermal markers to ascertain how this expansion of the neural forming region of the epiblast takes place. We conclude that the new neural cells formed are originated in the region of the epiblast fated to be epithelia and that the induction of the ectopic neural tissue is not mediated by an increase, migration or new formation of axial mesoderm. This strongly suggests that FGF is acting directly on epiblast cells, changing their fate from epidermal ectoderm to neural ectoderm. Therefore, our results show that FGF can induce neural ectoderm when acting on still uncommitted cells and, therefore, it is a putative candidate for acting in normal neural induction during development.

Sphingomyelin derivatives increase the frequency of microvesicle and granule fusion in chromaffin cells.

Sphingomyelin derivatives like sphingosine have been shown to enhance secretion in a variety of systems, including neuroendocrine and neuronal cells. By studying the mechanisms underlying this effect, we demonstrate here that sphingomyelin rafts co-localize strongly with synaptosomal-associated protein of 25Kda (SNAP-25) clusters in cultured bovine chromaffin cells and that they appear to be linked in a dynamic manner. In functional terms, when cultured rat chromaffin cells are treated with sphingomyelinase (SMase), producing sphingomyelin derivatives, the secretion elicited by repetitive depolarizations is enhanced. This increase was independent of cell size and it was significant 15min after initiating stimulation. Interestingly, by evaluating the membrane capacitance we found that the events in control untreated cells corresponded to two populations of microvesicles and granules, and the fusion of both these populations is clearly enhanced after treatment with SMase. Furthermore, SMase does not increase the size of chromaffin granules. Together, these results strongly suggest that SNARE-mediated exocytosis is enhanced by the generation of SMase derivatives, reflecting an increase in the frequency of fusion of both microvesicles and chromaffin granules rather than an increase in the size of these vesicles.

Morphologic characteristics and structure of surface excrescences (Lambl's excrescences) in the normal aortic valve.

The incidence, morphologic characteristics and structure of surface valve excrescences (Lambl's excrescences) were studied by transmission and scanning electron microscopy of the aortic valve of 56 human subjects, age range birth to 91 years, without cardiac disease. Valve excrescences consisting of a core of connective tissue covered by the endocardium were observed in 90% of the subjects; the incidence was significantly lower in patients in the first decade of life. Two types of excrescences, lamellar and filiform, were found. Lamellar excrescences are located along the lower boundary of the lunulas and occurred more often in those younger than 30 years. Filiform excrescences appear most often in the nodulus Arantius and in the free-margin of the cusps. The excrescences of the nodulus are the most numerous. Free-margin excrescences are the least numerous and occur more frequently in persons older than 40 years. The connective tissue core of the filiform excrescences contains abundant collagen fibrils and elastic material arranged in apposed layers with different collagen fibril orientation. A circular zone devoid of identifiable connective tissue is present at the center of the filiform excrescences.

The behavior of pericardial versus porcine valve xenografts in the growing sheep model.

The comparative long-term behavior of the pericardial versus the porcine bioprostheses is not yet known. The need for long follow-up times to answer this question makes the growing sheep model an attractive alternative, given its ability to induce early valve degeneration. Sixty-three sheep, 12 to 16 weeks old, were operated on and received 39 porcine (11 Xenomedica, 10 Carpentier-Edwards S, nine Hancock I standard, and nine Hancock I T6-treated) and 24 pericardial (14 Mitroflow and 10 Ionescu-Shiley low profile) prostheses of clinical quality in the tricuspid position. Of the 52 operative survivors (32 received porcine valves and 20 received pericardial bioprostheses), six animals (five pericardial and one porcine) were eliminated because of bioprosthetic infection. Late sudden death before the scheduled killing occurred significantly more often (p less than 0.0001) in the pericardial (8/15 or 53%) than in the porcine group (1/31 or 3%). Calcium content of the explanted valves was significantly correlated with time in the pericardial group and the Xenomedica porcine prostheses (p less than 0.05) but not in the Hancock I and Carpentier-Edwards S valves, where it was only marginally significant (0.1 greater than p greater than 0.05). Linear regression analysis of tissue calcium content showed a similar slope for the pericardial group and Xenomedica porcine valves, in comparison with the remaining porcine valves. Comparison between the two lines using covariance analysis demonstrated a statistically significant difference between them, which shows that the pericardial and Xenomedica porcine valves appear to reach higher levels of calcification in a shorter follow-up time than the Hancock I, standard and T6-treated, and the Carpentier-Edwards S valve in this animal model.

In vivo experimental assessment of polytetrafluoroethylene trileaflet heart valve prosthesis.

This report summarizes the results of a series of experimental implantations of polytetrafluoroethylene valves in sheep. Twelve prostheses were implanted in the tricuspid position in weanling (3- to 4-month-old, 26 +/- 3 kg) sheep. The valve sizes were 23 mm (eight animals) and 25 mm (four animals). There were two early deaths, and the 10 survivors were killed in a stepwise manner to get a mineralization profile of the valve. There was one episode of acute thrombosis but no evidence of pulmonary thromboemboli in any animal. In all cases the leaflets were thin and unretracted, but in half of them one cusp or more were stiffened. One valve displayed a fixed outward eversion of the free margin of two leaflets. Macroscopic calcification was detected in seven specimens and always involved the commissural areas. Radiologic studies confirmed this calcium topography and revealed only one case of severe and diffuse mineralization. In most cases the cusps showed a grossly visible pannus that was thinner and less extensive than usually seen in bioprostheses. Examination with light microscopy disclosed a complete lack of infiltrating cells within the cuspal material (made of compact polytetrafluoroethylene). However, those parts of the prostheses made of expanded polytetrafluoroethylene (the material covering the valve frame and the sutures) did show infiltration by host cells and calcium. Mineralized lesions were of extrinsic type, involving fibrin and fibroelastic host tissue accumulated in the inflow aspect of the commissures. Examination with transmission electron microscopy disclosed electron-dense masses surrounded by an electron-lucent granular homogeneous material in areas of mineralization. The time-course evolution of the tissue calcium content shows a moderate mineralization rate (0.46 +/- 0.31 mg/gm of dry-weight material per week of follow-up) and a marginally significant positive correlation between calcium content and follow-up. Our results suggest that the polytetrafluoroethylene valves have a moderate overall calcification rate and that calcium deposits appear to be always related to the commissural region and to the presence of expanded polytetrafluoroethylene.

Degenerative pathologic findings after long-term implantation of bovine pericardial bioprosthetic heart valves.

Degeneration of bioprosthetic heart valves constitutes the most important limitation to their long-term durability and the factor that avoids a wider clinical use of these devices. We studied 26 degenerated bovine pericardial valves that belong to a series of 55 prostheses explanted for various reasons. Age of the patients at implantation of the valve and other factors predisposing to primary tissue failure did not seem to significantly influence the results obtained. Mean implantation time was longer for aortic than for mitral valves (p less than 0.05). Also, the mode of failure was different for mitral and aortic prostheses. Tearing of one or more leaflets without mineralization was more frequent (p less than 0.0025) among mitral than among aortic specimens. Coverage of the valve cusps by a macroscopically visible host sheath was more extensive on the outflow than on the inflow aspect (p less than 0.0015 aortic valves; p less than 0.015 mitral valves). On radiological examination the majority of valves had diffuse and severe mineralized lesions. Collagen degeneration was the most frequent histologic lesion to be found in both mineralized and calcium-free valves. Calcification was also frequent and appeared as mineral deposits that extended between different collagen planes. Scanning electron microscopy revealed the almost complete lack of "endothelium-like" cover on any of the valves and exposure of the underlying fibrous components of the pericardial tissue in areas subjected to abrasion. Transmission electron microscopy confirmed the collagen degeneration and disclosed electron-dense microparticles (probably mineralized) both in the extracellular space and within degenerated host connective tissue cells.

Morphology and significance of programmed cell death in the developing limb bud of the vertebrate embryo.

Cell death constitutes a basic mechanism accounting for many morphogenetic and histogenetic events during normal and abnormal development of embryonic organs and tissues. This article focuses on the major areas of mesodermal cell death occurring during vertebrate limb development. In early stages of limb development, cell death appears to reduce the amount of mesodermal tissue destined to form the anlage of the autopodium. In later stages, cell death plays a role sculpturing the shape of the digits. The morphology of the dying cells corresponds with apoptosis, but internucleosomal DNA fragmentation by endonuclease activation does not appear to be a precocious feature. The cell death program can be inhibited in vivo and in vitro by changing the environmental conditions of the prospective dying cells up to 6-10 h before death. In this review, we survey possible factors controlling the establishment of the cell death program. Information concerning the biochemical basis of cell death in the developing limb is also revised. Finally, the possible role of genes whose pattern of expression is coincident with the dying processes is discussed.

Cell shape and cytoskeletal organization of the endothelial cells of the semilunar heart valves in the developing chick.

The composition and arrangement of the cytoskeletal elements of the endothelium of the semilunar valves have been studied in the embryonic chick heart during the stages 30 to 38. Microtubules, vimentin intermediate filaments and actin microfilaments were constant components of the valvular endothelial cells in the studied stages. Scanning electron microscopy after Triton-X-100 extraction revealed significant differences in the tridimensional arrangement of the cytoskeleton in the course of valve development. In the ventricular face of the cusps the cytoskeletal elements displayed a progressive longitudinal alignment, while in the arterial face of the cusps the cytoskeleton maintained the appearance of a network. Transmission electron microscopy revealed that these differences were especially prominent for vimentin intermediate filaments, although a similar tendency was also observed for microtubules. Microfilaments were scarce in the endothelial cells of both faces of the cusps, and the stress fibers typical of the endothelial cells of the adult valves were not observed in the embryonic material. The significance of these results in valve morphogenesis and histogenesis and a possible linkage with differences in the local characteristics of the blood flow are discussed.

Immunofluorescent localization of tenascin during the morphogenesis of the outflow tract of the chick embryo heart.

The cono-truncus constitutes a complex segment of the developing heart that gives rise to the outflow tract of the ventricles and root of the pulmonary and aortic arteries. Numerous studies have revealed that the extracellular matrix plays a relevant role in most morphogenetic processes modulating cell behaviour. By means of immunofluorescence, we studied the distribution and possible involvement of tenascin during morphogenesis of the conus and truncus in chick embryo hearts between days 4.5-10 of incubation. Tenascin is an extracellular matrix glycoprotein with a significant role in morphogenesis and cell and tissue differentiation. Our results reveal a specific distribution of tenascin in the areas of the cono-truncus undergoing significant structural changes during morphogenesis of this cardiac segment, appearing mainly in the mesenchymal layer subjacent to the myocardial layer, the cono-truncal ridges and the aorto-pulmonary septum. The distribution of tenascin was compared and contrasted with that of collagen type I, which constitutes a further component of the extracellular matrix common to most developing connective tissues.

Structural arrangement of the extracellular matrix network during myocardial development in the chick embryo heart.

We analyzed the extracellular matrix and the connective tissue of the developing chick myocardium ("myocardial interstitium"). The importance of this myocardial element for heart function has been well documented both for the normal and pathologic adult hearts. However, little information is available on the organization of the embryonic myocardial interstitium and its modifications during development and increasing intracardiac pressure. In the present study we used light and scanning electron microscopic techniques, and lectin probes to study the interstitium of the ventricular myocardium of chick embryos from stage 29 (day 6 of development) until hatching. Our observations trace the progressive appearance and organization of the elements of the extracellular matrix, comprising the epimysium, perimysium and endomysium, which form a well-defined architectural network. Finally, we discuss the role of these elements of the extracellular matrix and their possible relation with the biomechanical properties of developing heart.

Glioblast migration in the optic stalk of the chick embryo.

Light and electron microscopy was used to study the chick embryo optic stalk from Hamburger and Hamilton stages 21 to 29. Observations of glioblast morphology in different developmental stages suggest that these cells undergo radial migration toward peripheral regions of the stalk. Immediately previous to and during migration, morphological changes were noted in the glioblasts, including the appearance of lateral prolongations which contribute to the subdivision of optic fiber fascicles and the radial elongation of their nucleus, which gives the impression of squeezing itself into the peripheral glioblastic prolongation. These phenomena occur in a retino-diencephalic direction, commencing in the distal optic stalk during stage 23 and continuing in subsequent stages. The significance of glioblastic migration is discussed in relation to possible mechanisms through which optic fiber fascicles, initially located on the surface of the stalk, come to lie in deeper areas of the stalk wall.

Age-dependent dystrophic calcification of the aortic valve leaflets in normal subjects.

The aortic valves of 43 subjects (14 females and 29 males, mean age 48.9 +/- 22.2 years, range 3-88 years), dying from accidental causes and without any previous record of cardiovascular disease, were studied. The whole aortic root was removed and morphological features recorded. Calcium content was determined by atomic absorption spectrophotometry. Calcium content sustained a positive significant correlation (p < 0.001) with age. Comparison of regression lines from subjects of different age groups disclosed a significantly greater slope in the regression line of persons older than 50 years than in those of the younger population (p < 0.05). The increase with age of calcium content displayed no significant differences between male and female nor between any of the three aortic cusps. The presence of Lambl's excrescences on the aortic leaflets became more frequent with age and was associated with a higher calcium content.

Morphological analysis of the fish heart ventricle: myocardial and connective tissue architecture in teleost species.

Light and scanning electron microscopy were used to study the structure of the heart ventricle in three species of marine teleost fishes: the hake (Merluccius merluccius), the angler fish (Lophius piscatorius) and the sea bream (Pagellus centrodontus). Our findings show the ventricle to be shaped differently in each species: tubular in the hake, saccular in the angler fish and pyramidal in the sea bream. From a structural viewpoint, interest was centered on two aspects: organization of the myocardial fibres and arrangement of connective tissue. In hake and angler fish ventricles, the myocardium was exclusively trabecular in nature, whereas the bream ventricle, in addition to trabecular myocardium, presented a thin compact layer. Muscle fibres showed precise patterns of organization at the level of the ventricular orifices. With the techniques used the intramyocardial connective tissue was detected in the following ventricular zones: i) at the level of subepicardial and subendocardial spaces, ii) surrounding the myocardial fascicles, and iii) surrounding individual myocardial cells. According to this structural study, the pyramidal ventricle of the fish should be considered as a ventricular pump with greater efficiency.

Neuroprotective actions of flavonoids.

The experimental evidences accumulated during last years point out a relevant role of oxidative stress in neurodegeneration. As anti-cellular oxidative stress agents flavonoids can act either as direct chemical antioxidants, the classic view of flavonoids as antioxidants, or as modulators of enzymes and metabolic and signaling pathways leading to an overshot of reactive oxygen species (ROS) formation, a more recently emerging concept. Flavonoids, a large family of natural antioxidants, undergo a significant hepatic metabolism leading to flavonoid-derived metabolites that are also bioactive as antioxidant agents. The development of more efficient flavonoid's based anti-oxidative stress therapies should also take into account their bioavailability in the brain using alternate administration protocols, and also that the major ROS triggering the cellular oxidative stress are not the same for all neurodegenerative insults and diseases. On these grounds, we have reviewed the reports on neuroprotection by different classes of flavonoids on cellular cultures and model animals. In addition, as they are now becoming valuable pharmacological drugs, due to their low toxicity, the reported adverse effects of flavonoids in model experimental animals and humans are briefly discussed.