Lingual Focal Hyperplastic Lesion in a Pediatric Patient: Report of an Unusual Case / Lesión hiperplásica focal lingual en un paciente pediátrico: Informe de un caso inusual

Abstract: Focal fibrous hyperplasia (FFH) is an oral mucosal localized non-neoplastic enlargement representing a reaction to chronic local irritations or injuries. The purpose of this report is to describe the management of an asymptomatic fibrotic lesion located in the tongue, in a preschooler boy. A 7-year-6-month old boy attended our clinic for the evaluation of an exophytic pedunculated tumor-like round mass located in the dorsal surface of the tongue. Based on the initial examination and the natural history of the lesion, the presumptive clinical diagnosis determined an irritation FFH. The lesion was surgically excised with a diode laser device, and the postoperative period evolution occurred without any complication. The appropriate treatment of FFH in children initially consists of the removal of local irritant factors. Excellent oral hygiene maintenance and close follow-up care are strongly suggested. Surgical excision is the most frequent modality for persistent lesions. Early diagnosis and proper management of FFH can reduce the risk of future recurrences or complications.

Resumen: La hiperplasia fibrosa focal (HFF) es un agrandamiento no neoplásico localizado en la mucosa oral que representa una reacción a irritaciones o lesiones locales crónicas. El propósito de este informe es describir el tratamiento de una lesión fibrótica asintomática ubicada en la lengua, en un niño en edad preescolar. Un niño de 7 años y 6 meses de edad asistió a nuestra clínica para la evaluación de una masa redonda exofítica y pedunculada con forma de tumor ubicada en la superficie dorsal de la lengua. Basado en el examen inicial y la historia natural de la lesión, el diagnóstico clínico presuntivo determinó una irritación HFF. La lesión se extirpó quirúrgicamente con un láser de diodo, y la evolución en el período postoperatorio se produjo sin ninguna complicación. El tratamiento apropiado de HFF en niños inicialmente consiste en la eliminación de factores irritantes locales. Se recomienda un excelente mantenimiento de la higiene bucal y una estrecha atención de seguimiento. La escisión quirúrgica es la modalidad más frecuente para lesiones persistentes. El diagnóstico temprano y el manejo adecuado de la HFF pueden reducir el riesgo de futuras recurrencias o complicaciones.

Actividad antioxidante y marcha fitoquímica de los capítulos de Tagetes filifolia Lag. "pacha anís" / Antioxidant activity and phytochemical screening of capitula of Tagetes filifolia Lag. or "pacha anís"

Objetivo: Estudiar la actividad antioxidante y marcha fitoquímica de los capítulos de Tagetes filifolia Lag. "pacha anís".Materiales y métodos: Estudio de tipo experimental en el cual se empleó 5 kg de los capítulos de la planta medicinal Tagetes filifolia lag., provenientes de Junín. Se usó el método de cribado fitoquímico de Olga Lock para la marcha fitoquímica y el método DPPH para la determinación de la actividad antioxidante. Se dividió la muestra en 3 grupos: etéreo, alcohol etílico y agua destilada a concentraciones de 100, 50 y 5 µg/ml.Resultados: Se encontró fenoles en cantidades abundantes tanto en el extracto en agua destilada como en el extracto en alcohol etílico, además este último tuvo cantidades moderadas de quinonas. Por otro lado, el extracto en alcohol etílico fue el que presentó el mayor porcentaje de captación de radicales libres (91.26%) a una concentración de 100 µg/ml, similares resultados se encontró con el extracto etéreo (88.94%) y el extracto en agua destilada (75.58%).Conclusiones: Los principales componentes químicos fueron fenoles y quinonas. El mayor efecto antioxidante se obtuvo del extracto etanólico de la planta Tagetes filifolia a una concentración de 100 µg/ml.

Mantenedor telescópico anterior en pérdida dental prematura en dentición decidua: caso clíncio / Anterior telescopic maintainer in premature loss of teeth in deciduous dentition: case report

Los dientes deciduos son los responsables de conservar el espacio para alinear los dientes permanentes. Sin embargo, aunque en el sector anterior no haya perdida de espacio, si un paciente presenta una perdida prematura de un incisivo superior deciduo y las piezas definitivas presentan una escasa calcificación de su raíz, es conveniente la mantención del espacio, de lo contrario realizar el control. Si sólo se ha perdido un incisivo, se puede indicar el uso de un mantenedor telescópico. Se presenta el caso de un niño de 5 años de edad, que acudió al Servicio de Operatoria Dental del Instituto Nacional de Salud del Niño (INSN), par fractura de corona de incisivo superior anteriormente tratada. El tratamiento consistió en la confección de un mantenedor telescópico anterior para suplir la carencia de este...

The deciduos teeth are responsible for preserving the space to align the permanent teeth. However, while in the anterior region is no loss of space, if a patient has a premature loss of a maxillary incisor deciduos and permanent teeth have poor root calcification, is appropriate space maintenance, otherwise make a control. If only it is lost one incisor, may be indicate the use of a telescopic maintainer. We present a case of a 5 year old boy, who attended the Operative Dental Service of the National Institute of Child Health, because he had a crown fracture previously treated in maxillary incisor. The treatment consisted in making an anterior telescopic maintainer to supply this deficiency...

HGF/c-Met signaling promotes liver progenitor cell migration and invasion by an epithelial-mesenchymal transition-independent, phosphatidyl inositol-3 kinase-dependent pathway in an in vitro model.

Oval cells constitute an interesting hepatic cell population. They contribute to sustain liver regeneration during chronic liver damage, but in doing this they can be target of malignant conversion and become tumor-initiating cells and drive hepatocarcinogenesis. The molecular mechanisms beneath either their pro-regenerative or pro-tumorigenic potential are still poorly understood. In this study, we have investigated the role of the HGF/c-Met pathway in regulation of oval cell migratory and invasive properties. Our results show that HGF induces c-Met-dependent oval cell migration both in normal culture conditions and after in vitro wounding. HGF-triggered migration involves F-actin cytoskeleton reorganization, which is also evidenced by activation of Rac1. Furthermore, HGF causes ZO-1 translocation from cell-cell contact sites to cytoplasm and its concomitant activation by phosphorylation. However, no loss of expression of cell-cell adhesion proteins, including E-cadherin, ZO-1 and Occludin-1, is observed. Additionally, migration does not lead to cell dispersal but to a characteristic organized pattern in rows, in turn associated with Golgi compaction, providing strong evidence of a morphogenic collective migration. Besides migration, HGF increases oval cell invasion through extracellular matrix, a process that requires PI3K activation and is at least partly mediated by expression and activation of metalloproteases. Altogether, our findings provide novel insights into the cellular and molecular mechanisms mediating the essential role of HGF/c-Met signaling during oval cell-mediated mouse liver regeneration.

Myosin isoform expression in the prehensile tails of didelphid marsupials: functional differences between arboreal and terrestrial opossums.

Prehensile tails are defined as having the ability to grasp objects and are commonly used as a fifth appendage during arboreal locomotion. Despite the independent evolution of tail prehensility in numerous mammalian genera, data relating muscle structure, physiology, and function of prehensile tails are largely incomplete. Didelphid marsupials make an excellent model to relate myosin heavy chain (MHC) isoform fiber type with structure/function of caudal muscles, as all opossums have a prehensile tail and tail use varies between arboreal and terrestrial forms. Expanding on our previous work in the Virginia opossum, this study tests the hypothesis that arboreal and terrestrial opossums differentially express faster versus slower MHC isoforms, respectively. MHC isoform expression and percent fiber type distribution were determined in the flexor caudae longus (FCL) muscle of Caluromys derbianus (arboreal) and Monodelphis domestica (terrestrial), using a combination of gel electrophoresis and immunohistochemistry analyses. C. derbianus expresses three MHC isoforms (1, 2A, 2X) that are distributed (mean percentage) as 8.2% MHC-1, 2.6% 1/2A, and 89.2% 2A/X hybrid fibers. M. domestica also expresses MHC-1, 2A, and 2X, in addition to the 2B isoform, distributed as 17.0% MHC-1, 1.3% 1/2A, 9.0% 2A, 75.2% 2A/X, and 0.3% 2X/B hybrid fibers. The distribution of similar isoform fiber types differed significantly between species (P < 0.001). Although not statistically significant, C. derbianus was observed to have larger cross-sectional area (CSA) for each corresponding fiber type along with a greater amount of extra-cellular matrix. An overall faster fiber type composition (and larger fibers) in the tail of an arboreal specialist supports our hypothesis, and correlates with higher muscle force required for tail hanging and arboreal maneuvering on terminal substrates. Conversely, a broader distribution of highly oxidative fibers in the caudal musculature is well suited for tail nest building/remodeling behaviors of terrestrial opossums.

Efecto antinociceptivo del extracto etanólico de las hojas de Maytenus macrocarpa (Ruiz & Pav.) Briq. ôchuchuhuasiõ mediante la prueba de contorsiones abdominales en ratones / Antinociceptive effect of the ethanol extract of the leaves of Maytenus macrocarpa (Ruiz & Pav.) Briq. ôchuchuhuasiõ Through the Writhing Test in mice

Objetivo: Determinar el efecto y actividad antinociceptiva de las hojas de Maytenus macrocarpa (Ruiz & Pav) Briq. ôchuchuhuasiõ mediante la prueba de contorsiones abdominales en roedor. Material y Métodos: Se utilizaron 40 ratones albinos machos, con pesos medios de 25g, se empleó la prueba de contorsiones abdominales para determinar la actividad antinociceptiva. El grupo Control, no recibió ninguna sustancia. Se administró extracto etanólico de las hojas de M. macrocarpa (Ruiz & Pav.) Briq. 2000 mg/kg, Tramadol 10 mg/kg y Diclofenaco sódico 10 mg/kg. Las sustancias fueron administradas por la vía oral una hora antes de la inducción de dolor. Para la validación estadística se usó la prueba de Shapiro-Wilk, ANOVA de una cola, Tukey, y Newman-Keuls. Resultados: El número de contorsiones abdominales fue 41+/- 3.04, 27+/- 3.55, 9 +/- 4.14, y 18 +/- 2.65 respectivamente. El porcentaje de inhibición de la conducta nociceptiva fue: 0%, 34%, 77%, y 55%. La prueba de ANOVA de una vía, demostró diferencias estadísticas (p<0.05, IC 95%), y la prueba de Tukey y Newman-Keuls, demostraron diferencias significativas entre los grupos, frente al control. Conclusiones: Se comprobó el efecto antinociceptivo de las hojas de Maytenus macrocarpa (Ruiz & Pav.) Briq. ôchuchuhuasiõ, en dosis de 2000 mg/kg.

Objetives: To determine the effect and antinociceptive activity of the leaves of Maytenus macrocarpa (Ruiz & Pav ) Briq . ôChuchuhuasi ô by the writhing test in rodents. Material and Methods: 40 male albino mice were used, with average weights of 25g, the writhing test was used to determine the antinociceptive activity. The experimental groups were: Control; received no substance, ethanol extract of the leaves of M. macrocarpa Briq (Ruiz & Pav.) 2000 mg/kg, Tramadol 10 mg/kg and 10mg Sodium Diclofenac /kg. The substances were administered orally one hour before the induction of pain. For statistical validation the Shapiro -Wilk test, one-tailed ANOVA, Tukey, and Newman -Keuls was used. Results: Writhing number was 41 +/- 3.04, 27 +/- 3.55, 9 +/- 4.14, and 18 +/- 2.65 respectively. The inhibition percentage of the nociceptive behavior was: 0%, 34%, 77% and 55%. The test of one-way ANOVA showed statistical differences (p < 0.05, 95% CI), and the Tukey and Newman-Keuls test showed significant differences between groups versus control. Conclusions: Antinociceptive effect of the leaves of Maytenus macrocarpa (Ruiz & Pav.) Briq ôChuchuhuasiô was found at doses of 2000 mg/kg.

Testosterone regulates bone response to inflammation.

This study evaluated the alveolar bone response to testosterone and the impact of Resolvin D2 (RvD2) on testosterone-induced osteoblast function. For the in vivo characterization, 60 male adult rats were used. Treatments established sub-physiologic (L), normal (N), or supra-physiologic (H) concentrations of testosterone. Forty rats were subjected to orchiectomy; 20 rats received periodical testosterone injections while 20 rats received testicular sham-operation. Four weeks after the surgeries, 10 rats in each group received a subgingival ligature around the lower first molars to induce experimental periodontal inflammation and bone loss. In parallel, osteoblasts were differentiated from neonatal mice calvariae and treated with various doses of testosterone for 48 h. Cell lysates and conditioned media were used for the determination of alkaline phosphatase, osteocalcin, RANKL, and osteoprotegerin. Micro-computed tomography linear analysis demonstrated that bone loss was significantly increased for both L and H groups compared to animals with normal levels of testosterone. Gingival IL-1ß expression was increased in the L group (p<0.05). Ten nM testosterone significantly decreased osteocalcin, RANKL, and OPG levels in osteoblasts; 100 nM significantly increased the RANKL:OPG ratio. RvD2 partially reversed the impact of 10 nM testosterone on osteocalcin, RANKL, and OPG. These findings suggest that both L and H testosterone levels increase inflammatory bone loss in male rats. While low testosterone predominantly increases the inflammatory response, high testosterone promotes a higher osteoblast-derived RANKL:OPG ratio. The proresolving mediator RvD2 ameliorates testosterone-derived downregulation of osteocalcin, RANKL, and OPG in primary murine osteoblasts suggesting a direct role of inflammation in osteoblast function.

Interacciones farmacológicas de las hojas de Maytenus macrocarpa o ôchuchuhuasiõ con fármacos inhibitorios y estimuladores de la motilidad intestinal / Pharmacological interactions from the leaves of Maytenus macrocarpa \"chuchuhuasi\" with inhibitory and stimulating bowel motility drugs

Objetivo: Determinar las posibles interacciones farmacológicas de las hojas de Maytenus macrocarpa, con fármacos estimulantes e inhibitorios de la motilidad intestinal. Métodos: Se utilizaron 110 ratones albinos machos, con pesos medios de 25 g, se empleó el método de Arbos y col, se administró carbón activado al 5

vía oral, dosis de 0.1ml/10g, como marcador intestinal. Los grupos experimentales fueron: control (agua destilada 0,3ml), hojas de chuchuhuasi 1 (500mg/kg), hojas de chuchuhuasi 2 (3000mg/kg), atropina (1,5mg/kg), loperamida (5mg/kg), neostigmina (0,4mg/kg), metoclopramida (10mg/kg), hojas de chuchuhuasi 1 con metoclopramida, hojas de chuchuhuasi 1 con loperamida, hojas de chuchuhuasi 2 con metoclopramida y hojas de chuchuhuasi 2 con loperamida. Para la validación estadística se usó la prueba de Wilconxon, ANOVA y Tukey. Resultados: El porcentaje de recorrido intestinal de carbón activado fue de 27,04, 34,15, 31,66, 25,57, 15,89, 43,30, 33,99, 32,40, 27,90, 49,34 y 25,36 respectivamente, el test de ANOVA de dos colas revelo una p=0,0007. El test de Tukey indico p<0.05 versus el control para neostigmina, loperamida y la interacción chuchuhuasi 3000 mg/kg con metoclopramida, en este último, el test de Wilconxon presento un valor p<0,05. Conclusiones: Se observó interacciones farmacológicas de antagonismo sobre la motilidad intestinal, entre chuchuhuasi y Loperamida y sinergismo entre chuchuhuasi y metoclopramida.

Objectives: To determine the possible pharmacological interactions from the leaves of Maytenus macrocarpa with inhibitory and stimulating bowel motility drugs. Methods: We used 110 male albino mice with average weight of 25g, Arbos and others method was applied. Activated charcoal was administered at 5

at dose of 0.1ml/10g, as an intestinal marker. The experimental groups included 0.1 ml/10 g of distilled water, leave extract of M. macrocarpa 1 (500mg/kg), leave extract of M. macrocarpa 2 (3000 mg/kg), 1,5mg/kg of atropine, 5mg/kg of loperamide, 0.4mg/kg of neostigmine, 10mg/kg of metoclopramide, leave extract of M. macrocarpa 1 with metoclopramide, leave extract of M. macrocarpa 1 with loperamide, leave extract of M. macrocarpa 2 with metoclopramide and leave extract of M. macrocarpa 2 with loperamide. The statistical validation was based on Wilconxon, ANOVA and Tukey test. Results: The intestinal charcoal run percentage was 27.04, 34.15, 31.66, 25.57, 15.89, 43.30, 33.99, 32.40, 27.9, 49.34 and 25.36 respectively. The ANOVA test result in p= 0.0007. The Tukey test indicated p <0.05 versus the control group for neostigmine, loperamide, and the interaction between leave extract of M. macrocarpa 2 with metoclopramide, for the last the Wilcoxon test result in p <0.05. Conclusions: It was observed antagonism drug interactions on gastrointestinal motility between leaves extract of M. macrocarpa with loperamide and synergism interactions with metoclopramide.

EGFR is dispensable for c-Met-mediated proliferation and survival activities in mouse adult liver oval cells.

Liver progenitor cells rise as potential critical players in hepatic regeneration but also carcinogenesis. It is therefore mandatory to define the signals controlling their activation and expansion. Recently, by using a novel in vitro model of oval cell lines expressing a mutant tyrosine kinase-inactive form of c-Met we demonstrated that autocrine c-Met signalling plays an essential role in promoting oval cell survival. Here, we investigated the significance of the epidermal growth factor receptor (EGFR) signalling in oval cell proliferation and survival, as well as a potential functional crosstalk between the c-Met and the EGFR pathways. We found an autocrine activation of the EGFR-triggered pathway in Met(flx/flx) and Met(-/-) oval cells as judged by constitutive expression of the EGFR ligands, transforming growth factor-alpha (TGF-α) and heparin-binding EGF like growth factor (HB-EGF), and activation of EGFR. On the other hand, treatment with AG1478, a specific inhibitor of EGFR, effectively blocked endogenous and EGF-induced proliferation, while increased serum withdrawal and transforming growth factor-beta (TGF-ß)-induced apoptosis. These results suggest that constitutively activated EGFR might promote oval cell proliferation and survival. We found that hepatocyte growth factor (HGF) does not transactivate EGFR nor EGF transactivates c-Met. Furthermore, treatment with AG1478 or EGFR gene silencing did not interfere with HGF-mediated activation of target signals, such as protein kinase B (AKT/PKB), and extracellular signal-regulated kinases 1/2 (ERK 1/2), nor did it have any effect on HGF-induced proliferative and antiapoptotic activities in Met(flx/flx) cells, showing that HGF does not require EGFR activation to mediate such responses. EGF induced proliferation and survival equally in Met(flx/flx) and Met(-/-) oval cells, proving that EGFR signalling does not depend on c-Met tyrosine kinase activity. Together, our results provide strong evidence that in normal, untransformed oval cells, c-Met and EGFR represent critical molecular players to control proliferation and survival that function independent of one another.

Association of UV radiation with multiple sclerosis prevalence and sex ratio in France.

BACKGROUND: French farmers and their families constitute an informative population to study multiple sclerosis (MS) prevalence and related epidemiology. We carried out an ecological study to evaluate the association of MS prevalence and ultraviolet (UV) radiation, a candidate climatologic risk factor. METHODS: Mean annual and winter (December-March) UVB irradiation values were systematically compared to MS prevalence rates in corresponding regions of France. UVB data were obtained from the solar radiation database (SoDa) service and prevalence rates from previously published data on 2,667 MS cases registered with the national farmer health insurance system, Mutualité Sociale Agricole (MSA). Pearson correlation was used to examine the relationship of annual and winter UVB values with MS prevalence. Male and female prevalence were also analyzed separately. Linear regression was used to test for interaction of annual and winter UVB with sex in predicting MS prevalence. RESULTS: There was a strong association between MS prevalence and annual mean UVB irradiation (r = -0.80, p < 0.001) and average winter UVB (r = -0.87, p < 0.001). Both female (r = -0.76, p < 0.001) and male (r = -0.46, p = 0.032) prevalence rates were correlated with annual UVB. Regression modeling showed that the effect of UVB on prevalence rates differed by sex; the interaction effect was significant for both annual UVB (p = 0.003) and winter UVB (p = 0.002). CONCLUSIONS: The findings suggest that regional UVB radiation is predictive of corresponding MS prevalence rates and supports the hypothesis that sunlight exposure influences MS risk. The evidence also supports a potential role for gender-specific effects of UVB exposure.

Performance of a flameless combustion furnace using biogas and natural gas.

Flameless combustion technology has proved to be flexible regarding the utilization of conventional fuels. This flexibility is associated with the main characteristic of the combustion regime, which is the mixing of the reactants above the autoignition temperature of the fuel. Flameless combustion advantages when using conventional fuels are a proven fact. However, it is necessary to assess thermal equipments performance when utilizing bio-fuels, which usually are obtained from biomass gasification and the excreta of animals in bio-digesters. The effect of using biogas on the performance of an experimental furnace equipped with a self-regenerative Flameless burner is reported in this paper. All the results were compared to the performance of the system fueled with natural gas. Results showed that temperature field and uniformity are similar for both fuels; although biogas temperatures were slightly lower due to the larger amount of inert gases (CO(2)) in its composition that cool down the reactions. Species patterns and pollutant emissions showed similar trends and values for both fuels, and the energy balance for biogas showed a minor reduction of the efficiency of the furnace; this confirms that Flameless combustion is highly flexible to burn conventional and diluted fuels. Important modifications on the burner were not necessary to run the system using biogas. Additionally, in order to highlight the advantages of the Flameless combustion regime, some comparisons of the burner performance working in Flameless mode and working in conventional mode are presented.

Short-term induction of thrombocytopenia delays periodontal healing in rats with periodontal disease: participation of endostatin and vascular endothelial growth factor.

BACKGROUND AND OBJECTIVE: Platelets contain factors, including VEGF and endostatin, that can modulate the healing process. We evaluated the effects of severe thrombocytopenia on periodontal healing in rats and determined the contribution of VEGF and endostatin to the healing process. MATERIAL AND METHODS: Rats were distributed into three test groups and two control groups. Cotton ligatures were placed at the gingival margin level of the lower first molar in the test groups. Sham-operated rats and rats in one of the periodontitis groups were killed 15 days later. Rats in the remaining two periodontitis groups had the ligatures removed in order to study the spontaneous recovery from the periodontal disease 15 days later, and these rats were treated with rabbit antiplatelet serum, in order to induce thrombocytopenia, or normal rabbit serum. An additional group without ligatures received antiplatet serum in the same period. RESULTS: After ligature removal, rats treated with normal rabbit serum showed reduced myeloperoxidase activity, decreased alveolar bone loss and increased numbers of blood vessels. Thrombocytopenia caused a delay in alveolar bone regeneration, a decrease in the number of vessels and a modest decrease in myeloperoxidase activity. In the rats with periodontitis, serum endostatin concentrations were slightly decreased and serum VEGF remained unchanged compared with sham-operated animals. After ligature removal, a significant VEGF increase and endostatin decrease were observed in the rats treated with normal rabbit serum. Thrombocytopenia led to a dramatic fall in both VEGF and endostatin concentrations. CONCLUSION: Thrombocytopenia leads to a delay of periodontal healing in the situation of experimental periodontitis, which might be mediated in part by a decrease in the serum concentration of VEGF and endostatin derived from the platelets. However, other factors derived from the platelets may also have contributed to a delay of periodontal healing in the rats with thrombocytopenia.

An extremes of outcome strategy provides evidence that multiple sclerosis severity is determined by alleles at the HLA-DRB1 locus.

Multiple sclerosis (MS) is a common inflammatory disease of the central nervous system unsurpassed for variability in disease outcome. A cohort of sporadic MS cases (n = 163), taken from opposite extremes of the distribution of long-term outcome, was used to determine the role of the HLA-DRB1 locus on MS disease severity. Genotyping sets of benign and malignant MS patients showed that HLA-DRB1*01 was significantly underrepresented in malignant compared with benign cases. This allele appears to attenuate the progressive disability that characterizes MS in the long term. The observation was doubly replicated in (i) Sardinian benign and malignant patients and (ii) a cohort of affected sibling pairs discordant for HLA-DRB1*01. Among the latter, mean disability progression indices were significantly lower in those carrying the HLA-DRB1*01 allele compared with their disease-concordant siblings who did not. The findings were additionally supported by similar transmission distortion of HLA-DRB1*04 subtypes closely related to HLA-DRB1*01. The protective effect of HLA-DRB1*01 in sibling pairs may result from a specific epistatic interaction with the susceptibility allele HLA-DRB1*1501. A high-density (>700) SNP examination of the MHC region in the benign and malignant patients could not identify variants differing significantly between the two groups, suggesting that HLA-DRB1 may itself be the disease-modifying locus. We conclude that HLA-DRB1*01, previously implicated in disease resistance, acts as an independent modifier of disease progression. These results closely link susceptibility to long-term outcome in MS, suggesting that shared quantitative MHC-based mechanisms are common to both, emphasizing the central role of this region in pathogenesis.

The role of hereditary spastic paraplegia related genes in multiple sclerosis. A study of disease susceptibility and clinical outcome.

Multiple sclerosis (MS) is a common inflammatory disease of the central nervous system unsurpassed for its variability in disease outcome. It has been observed that axonal loss in MS is significant and that irreversible clinical disability relates to such axonal loss. The clinical similarities between Hereditary Spastic Paraplegia (HSP) and progressive MS, along with their analogous profiles of axonal loss in the long tracts, make the genes known to cause HSP biologically relevant candidates for the study of clinical outcome in MS. A cohort of sporadic MS cases and a set of unaffected controls were used to determine the role of HSP genes on MS susceptibility and disease severity. The MS cases were taken from opposite extremes of the putative distribution of long-term outcome using the most stringent clinical criteria to date. Genotyping the two sets of MS patients and controls could not provide any evidence to suggest that genes involved in the pathogenesis of HSP (Paraplegin, NIPA1, KIF5A, HSPD1, Atlastin, Spartin, Spastin, PLP1, L1CAM, Maspardin and BSCL2) play a role in susceptibility to, or modifying the course of, MS, although small effects of these genes cannot be ruled out.

No effect of APOE and PVRL2 on the clinical outcome of multiple sclerosis.

Multiple sclerosis (MS) is a common inflammatory disease of the central nervous system unsurpassed for its variability in disease outcome. Apolipoprotein E (APOE) is involved in neuronal remodelling and several studies have attempted to examine the effect of APOE on MS disease severity, but its function in modifying the course of MS is controversial. It has been suggested recently that PVRL2, not APOE, is the locus on chromosome 19 which influences clinical outcome of MS. A cohort of sporadic MS cases, taken from opposite extremes of the putative distribution of long-term outcome using the most stringent clinical criteria to date, was used to determine the role of APOE and PVRL2 on MS disease severity. The MS cases selected represent the prognostic best 5% (benign MS) and worst 5% (malignant MS) of cases in terms of clinical outcome assessed by the EDSS. Genotyping the two sets of MS patients (112 benign and 51 malignant) and a replication cohort from Sardinia provided no evidence to suggest that APOE or PVRL2 have any outcome modifying activity. We conclude that APOE and PVRL2 have little or no effect on the clinical outcome of MS.

Role of elastic fibers in cooling-induced relaxation.

The objective of this work was to confirm the main role of elastic fibers in differing responses of certain vessels during cooling from 37 to 8 degrees C. Previous results have shown that the nature of the vessel (conduit vessel vs muscular vessel) determines the different behavior (dilatation vs contraction) of isolated vessel segments when temperature decreases from 37 to 8 degrees C. In this work, it has been demonstrated that vessels with a great amount of elastic fibers show a dilatation when cooling. On the other hand, muscular vessels with fewer elastic fibers, such as the renal artery, undergo a contraction. The output of calcium from intracellular stores causes contraction of the renal artery during cooling. In this vessel, vasodilatation occurs only when mechanisms of smooth muscle contraction are inactive, as is the case with vessels that have undergone a cold storage period of 48 h. The results presented in this work confirm that there are two main effects, which directly depend on the vessel origin. In conduit arteries, the decrease of temperature induces a vascular relaxation, dependent on the elastic component of the vessel wall. In muscular vessels, the predominant effect is cooling-induced contraction due to an increase of intracellular calcium. This cooling-induced contraction needs the vessel to be in optimal conditions with an active metabolism of the muscular cells. These results are a crucial issue in the sense of explaining several biomedical mechanisms where hypothermia is implicated. The type of vessel implicated in procedures, such as isolated organ perfusion, extracorporeal circulation, and bypass surgery, must be taken into account.

Albumin-derived advanced glycation end-products trigger the disruption of the vascular endothelial cadherin complex in cultured human and murine endothelial cells.

Endothelial cell (EC) junctions regulate in large part the integrity and barrier function of the vascular endothelium. Advanced glycation end-products (AGEs), the irreversibly formed reactive derivatives of non-enzymic glucose-protein condensation reactions, are strongly implicated in endothelial dysfunction that distinguishes diabetes- and aging-associated vascular complications. The aim of the present study was to determine whether AGEs affect EC lateral junction proteins, with particular regard to the vascular endothelial cadherin (VE-cadherin) complex. Our results indicate that AGE-modified BSA (AGE-BSA), a prototype of advanced glycated proteins, disrupts the VE-cadherin complex when administered to ECs. AGE-BSA, but not unmodified BSA, was found to induce decreases in the levels of VE-cadherin, beta-catenin and gamma-catenin in the complex and in total cell extracts, as well as a marked reduction in the amount of VE-cadherin present at the cell surface. In contrast, the level of platelet endothelial cell adhesion molecule-1 (PECAM-1), which is located at lateral junctions, was not altered. Supplementation of the cellular antioxidative defences abolished these effects. Finally, the loss of components of the VE-cadherin complex was correlated with increases in vascular permeability and in EC migration. These findings suggest that some of the AGE-induced biological effects on the endothelium could be mediated, at least in part, by the weakening of intercellular contacts caused by decreases in the amount of VE-cadherin present.

Activation of caspases occurs downstream from radical oxygen species production, Bcl-xL down-regulation, and early cytochrome C release in apoptosis induced by transforming growth factor beta in rat fetal hepatocytes.

Most of the morphologic changes that are observed in apoptotic cells are caused by a set of cysteine proteases (caspases) that are activated during this process. In previous works from our group we found that treatment of rat fetal hepatocytes with transforming growth factor beta1 (TGF-beta1) is followed by apoptotic cell death. TGF-beta1 mediates radical oxygen species (ROS) production that precedes bcl-xL down-regulation, loss of mitochondrial transmembrane potential, release of cytochrome c, and activation of caspase-3 (Herrera et al., FASEB J 2001;15:741-751). In this work, we have analyzed how TGF-beta1 activates the caspase cascade and whether or not caspase activation precedes the oxidative stress induced by this factor. Our results show that TGF-beta1 activates at least caspase-3, -8, and -9 in rat fetal hepatocytes, which are not required for ROS production, glutathione depletion, bcl-xL down-regulation, and initial cytochrome c release. However, caspase activation mediates cleavage of Bid and Bcl-xL that could originate an amplification loop on the mitochondrial events. An interesting result is that transmembrane potential disruption occurs later than the initial cytochrome c release and is mostly blocked by the pan-caspase inhibitor Z-VAD.fmk, indicating that the decrease in mitochondrial transmembrane potential (Delta(Psi)m) may be a consequence of caspase activity rather than the mechanism by which TGF-beta induces cytochrome c efflux. Finally, although Z-VAD.fmk completely blocks nucleosomal DNA fragmentation, it only delays cell death, which suggests that activation of the apoptotic program by TGF-beta in fetal hepatocytes inevitably leads to death, with or without caspases.

Activation of p38MAPK by TGF-beta in fetal rat hepatocytes requires radical oxygen production, but is dispensable for cell death.

We have previously found that transforming growth factor-beta (TGF-beta) induces an increase in radical oxygen species (ROS) production that mediates its apoptotic effects in fetal hepatocytes. In this paper we show that TGF-beta activates p38 mitogen-activated protein kinase (p38MAPK) and ROS may be responsible for this activation. Activation of p38MAPK occurs late, coincident with the maximal production of ROS, it is inhibited by radical scavengers and it is accentuated by the presence of glutathione synthesis inhibitors. However, p38MAPK does not appear to be involved in any of the apoptotic events: loss of Bcl-x(L) levels, cytochrome c release, cleavage of caspase substrates and loss of cell viability.