Interacción de la peroxisomicina A1 con el factor de necrosis tumoral alfa in vitro

Tesis (Doctorado en Ciencias con Especialidad en Farmacología y Toxicología) UANL

Pathological Investigations in penaeid Prawns

The thesis embodies the results of the studies carried out on certain diseases affecting the commercially important penaeid prawns in the capture and culture fisheries of the southwest and southeast coasts of india during october, 1981 to april 1985.initially a survey is conducted to obtain information and to understand the commom diseases and abnormalities occurring in the penaeid prawms in nature and those farmed. A result of the survey then cases of diseases and abnormalities are reported. These include tumour like growth soft prawm syndrome, tail necrosis brown spot disease, red rostrum, ciliate infestation ,helminth parasitisation,metacercarial infestation and bopyrid infestation in the penaeid prawns such as penaeus indicus p. monodon , p. semisulcatus ,Metapenaeus dobsoni and m.affinis.The symptoms ,occurrence and incidence of each of the above cases are provided along with the information on environmental factors such as salinity,dissolved oxygen,temperature and ph of the water from the collection sites. The nature of the disease,the tissuse of the host that are affected by the infection or infestation or by the pathogen ,and the actors influencing the infection in each of the ten cases are studied histopathologically and discussed. In the light of the available published information, the control measures for the different diseases of penaeid prawns are presented and discussed.

Factors associated to avascular necrosis of the femoral head and non-union in patients younger than 65 years old with displaced femoral neck fractures treated with reduction and internal fixation.

Pocos estudios han evaluado el tratamiento de las fracturas desplazadas de cuello femoral en pacientes menores de 65 años de edad, y no han sido claramente definidos los factores de riesgo para necrosis avascular o no-unión dentro de este rango de edad. Para determinar los factores asociados a la necrosis avascular de la cabeza femoral (AVN) y no-unión en pacientes menores de 65 años de edad con fracturas desplazadas del cuello femoral tratados con reducción y fijación interna, se realizó un estudio retrospectivo de 29 fracturas desplazadas del cuello femoral en 29 pacientes consecutivos tratados en una sola institución. La influencia de la edad, la energía del trauma, tipo de reducción, y el tiempo entre la fractura y el tratamiento en desarrollo de la AVN y no-unión fueron evaluados. Los pacientes que desarrollaron NAV fueron significativamente mayores y sufrieron un trauma de más baja energía que en los casos sin AVN. Ninguna variable fue asociada con la no-unión. La regresión logística determinó que sólo la edad se asoció de forma independiente a NAV. La edad es un buen predictor para el desarrollo de NAV, con un C-estadístico de 0.861, y un mejor corte-determinado en 53,5 años. Conclusión: Los pacientes de entre 53,5 y 65 años presentan un riesgo más alto de NAV. La artroplastia primaria se debe considerar en este subgrupo.

Resultados en reducción abierta de cadera por via interna: necrosis avascular y concordancia interobservador

Introducción: la luxación típica de la cadera es una patología con alta incidencia, de ahí la necesidad de métodos efectivos para lograr una reducción de esta. Han surgido varios métodos de reducción, uno de estos métodos es la reducción abierta por vía interna. Metodología Estudió descriptivo retrospectivo, incluyo los casos operados de reducción abierta por vía interna en el Instituto de Ortopedia Infantil Roosevelt y Clínica Jorge Piñeros Corpas por uno de los tutores, desde enero de 2006 hasta junio de 2011, valorando estas caderas según los criterios de Salter de necrosis avascular (NAV), con un seguimiento mínimo de 18 meses. Se evaluó la concordancia interobservador para la clasificación de Salter en tres ortopedistas infantiles. Resultados Se evaluaron 20 caderas en 16 pacientes a los que se realizo reducción abierta de luxación típica de cadera por vía interna. El 40 % de las caderas presentaron NAV, el 75% de estas caderas presentan NAV tipo I según la clasificación de Kalamchi. El índice Kappa para la clasificación de Salter en tres ortopedistas infantiles fue 0.6. Discusión El abordaje por vía interna para la reducción de luxación de cadera típica en niños menores de 18 meses es una alternativa más para el manejo de estos pacientes, que puede producir NAV en la cadera, pero esta NAV es tipo I de Kalamchi en la mayoría de casos. La reproducibilidad de la radiografía para la evaluación de NAV, realizada por personas expertas es buena, medida con índice kappa de 0.6.

Brain Tumour, Mood Disorder and Encephalopathy. Discusion of the Clinical Case Presented in Volume 6, Number 2

We report a case of a 65 years old female patient, who was admitted to the hospital with non specific neurological symptoms and who had preliminary imagenological findings of an extra-axial tumor mass (a meningioma of the sphenoid’s wing), which was taken to complete surgical removal. Afterwards, she developed progressive neurologic deterioration until her death. The final diagnosis was acute spongiform encephalophaty, and was obtained by cerebral biopsy. Spongiform encephalopathy was described, almost a century ago, as the Creutzfeldt-Jakob Disease, poorly diagnosed in our environment because of its low frequency and uncommon onset, which starts with a mood disorder followed by a phase of dementia and a final fatal outcome. The gold standard for the diagnosis is based on a biopsy or an autopsy of the brain, with immunohistochemical stains for the prionic abnormal protein.

Brain Tumour, Mood Disorder and Encephalopathy. Discusion of the Clinical Case Presented in Volume 6, Number 2

We report a case of a 65 years old female patient, who was admitted to the hospital with non specific neurological symptoms and who had preliminary imagenological findings of an extra-axial tumor mass (a meningioma of the sphenoid’s wing), which was taken to complete surgical removal. Afterwards, she developed progressive neurologic deterioration until her death. The final diagnosis was acute spongiform encephalophaty, and was obtained by cerebral biopsy. Spongiform encephalopathy was described, almost a century ago, as the Creutzfeldt-Jakob Disease, poorly diagnosed in our environment because of its low frequency and uncommon onset, which starts with a mood disorder followed by a phase of dementia and a final fatal outcome. The gold standard for the diagnosis is based on a biopsy or an autopsy of the brain, with immunohistochemical stains for the prionic abnormal protein.

Glycan alterations of serum proteins as tumour markers. Prostate-specific antigen in prostate cancer and acute-phase proteins in pancreatic cancer

Els pacients amb càncer presenten una taxa de supervivència superior si es diagnostiquen a estadis inicials, per la qual cosa és indispensable disposar de marcadors tumorals adequats. Glicoformes de proteïnes específiques es podrian utilizar com marcadors tumorals. S’han investigat les subformes i glicosilació de l’Antígen Prostàtic Específic (PSA) per millorar la seva capacitat de diagnosis de pacients amb càncer de pròstata vs aquells amb hiperplàsia benigna prostàtica. També s’han avaluat glicoproteïnes sèriques amb alteracions glucídiques en pacients de càncer de pàncrees, comparat amb pacients amb pancreatitis crònica i controls. S’ha observat una disminució de la fucosilació core i sialilació del PSA en càncer de pròstata i un augment de la fucosilació core i Sialyl-Lewis X en algunes Proteïnes de fase Aguda en càncer de pàncrees. Aquest canvis s’haurien d’avaluar en un cohort de pacients més gran per determinar el seu paper en el cribratge, diagnòstic o monitorització dels cancers estudiats.

Modelling the formation of necrotic regions in avascular tumours

The mechanisms underlying the formation of necrotic regions within avascular tumours are not well understood. In this paper, we examine the relative roles of nutrient deprivation and of cell death, from both the proliferating phase of the cell cycle via apoptosis and from the quiescent phase via necrosis, in changing the structure within multicellular tumour spheroids and particularly the accumulation of dead cell material in the centre. A mathematical model is presented and studied that accounts for nutrient diffusion, changes in cell cycling rates, the two different routes to cell death as well as active motion of cells and passive motion of the dead cell material. In studying the accumulation of dead cell matter we do not distinguish between the route by which each was formed. The resulting mathematical model is examined for a number of scenarios. Results show that in many cases the size of the necrotic core is closely correlated with low levels in nutrient concentration. However, in certain cases, particularly where the rate of necrosis is large, the resulting necrotic core can lead to regions of non-negligible nutrient concentration-dependent upon the mode of cell death.

Apical leaf necrosis as a defence mechanism against pathogen attack: effects of high nutrient availability on onset and rate of necrosis

An outdoor experiment was conducted to increase understanding of apical leaf necrosis in the presence of pathogen infection. Holcus lanatus seeds and Puccinia coronata spores were collected from two adjacent and otherwise similar habitats with differing long-term N fertilization levels. After inoculation, disease and necrosis dynamics were observed during the plant growing seasons of 2003 and 2006. In both years high nutrient availability resulted in earlier disease onset, a higher pathogen population growth rate, earlier physiological apical leaf necrosis onset and a reduced time between disease onset and apical leaf necrosis onset. Necrosis rate was shown to be independent of nutrient availability. The results showed that in these nutrient-rich habitats H. lanatus plants adopted necrosis mechanisms which wasted more nutrients. There was some indication that these necrosis mechanisms were subject to local selection pressures, but these results were not conclusive. The findings of this study are consistent with apical leaf necrosis being an evolved defence mechanism.

Apical leaf necrosis and leaf nitrogen dynamics in diseased leaves: a model study

Apical leaf necrosis is a physiological process related to nitrogen (N) dynamics in the leaf. Pathogens use leaf nutrients and can thus accelerate this physiological apical necrosis. This process differs from necrosis occurring around pathogen lesions (lesion-induced necrosis), which is a direct result of the interaction between pathogen hyphae and leaf cells. This paper primarily concentrates on apical necrosis, only incorporating lesion-induced necrosis by necessity. The relationship between pathogen dynamics and physiological apical leaf necrosis is modelled through leaf nitrogen dynamics. The specific case of Puccinia triticina infections on Triticum aestivum flag leaves is studied. In the model, conversion of indirectly available N in the form of, for example, leaf cell proteins (N-2(t)) into directly available N (N-1(t), i.e. the form of N that can directly be used by either pathogen or plant sinks) results in apical necrosis. The model reproduces observed trends of disease severity, apical necrosis and green leaf area (GLA) and leaf N dynamics of uninfected and infected leaves. Decreasing the initial amount of directly available N results in earlier necrosis onset and longer necrosis duration. Decreasing the initial amount of indirectly available N, has no effect on necrosis onset and shortens necrosis duration. The model could be used to develop hypotheses on how the disease-GLA relation affects yield loss, which can be tested experimentally. Upon incorporation into crop simulation models, the model might provide a tool to more accurately estimate crop yield and effects of disease management strategies in crops sensitive to fungal pathogens.

Analysis of void volumes in proteins and application to stability of the p53 tumour suppressor protein

We have developed a new method for the analysis of voids in proteins (defined as empty cavities not accessible to solvent). This method combines analysis of individual discrete voids with analysis of packing quality. While these are different aspects of the same effect, they have traditionally been analysed using different approaches. The method has been applied to the calculation of total void volume and maximum void size in a non-redundant set of protein domains and has been used to examine correlations between thermal stability and void size. The tumour-suppressor protein p53 has then been compared with the non-redundant data set to determine whether its low thermal stability results from poor packing. We found that p53 has average packing, but the detrimental effects of some previously unexplained mutations to p53 observed in cancer can be explained by the creation of unusually large voids. (C) 2004 Elsevier Ltd. All rights reserved.

Pectin and pectic-oligosaccharides induce apoptosis in in vitro human colonic adenocarcinoma cells

Background: Dietary fibres have been associated with decreased risk of various cancers, although the mechanisms are unclear. Induction of apoptosis in tumour cells is thought to be an important protective mechanism against colorectal cancer. This work investigates the effects of pectins and pecticoligosaccharides (POS) on the human colonic adenocarcinoma cell line HT29. Materials and Methods: The anti-proliferative effects of pectin and POS were studied by testing the HT29 cells for cytotoxicity, differentiation and/or apoptosis by lactate dehydrogenase, alkaline phosphatase and caspase-3 activity assays. DNA agarose gel electrophoresis was also carried out. Results: A significant reduction in attached cell numbers was observed after three days incubation. This decrease was neither due to cells undergoing necrosis nor differentiation. Increased apoptosis frequency, after incubation with 1% (w/v) pectin andlor POS, was demonstrated by caspase-3 activity and DNA laddering on agarose gel electrophoresis. Conclusion: Dietary pectins and their degradation products may contribute to the reported protective effects of fruits against colon cancer.

Gut fermentation products of insulin-derived prebiotics beneficially modulate markers of tumour progression in human colon tumour cells

Insulin is a prebiotic food ingredient, which suppresses colon tumour growth and development in rats. In the gut lumen, it is fermented to lactic acid and short chain fatty acids (SCFA). Of these, butyrate has suppressing agent activities, but little is known concerning cellular responses to complex fermentation samples. To investigate the effects of fermentation products of insulin on cellular responses related to colon carcinogenesis. Fermentations were performed in anaerobic batch cultures or in a three-stage fermentation model that simulates conditions in colon-segments (proximal, transverse, distal). Substrate was insulin enriched with oligofructose (Raftilose® Synergy1), fermented with probiotics (Bifidobacterium lactis Bb12, Lactobacillus rhamnosus GG), and/or faecal inocula. HT29 or CaCo-2 cells were incubated with supernatants of the fermented samples (2.5%-25% v/v, 24-72 hours). Cellular parameters of survival, differentiation, tumour progression, and invasive growth were determined. Fermentation supernatants derived from probiotics and Synergy1 were more effective than with glucose. The additional fermentation with faecal slurries produced supernatants with lower toxicity, higher SCFA contents, and distinct cellular functions. The supernatant derived from the gut model vessel representing the distal colon, was most effective for all parameters, probably on account of higher butyrate-concentrations. Biological effects of insulin upon colon cells may be mediated not only by growth stimulation of the lactic acid-producing bacteria and/or production of butyrate, but also by other bacteria and products of the gut lumen. These newly reported properties of the supernatants to inhibit growth and metastases in colon tumour cells are important mechanisms of tumour suppression.

Antitumour activity of [1,2-di(cyclopentadienyl)-1,2-di(p-N,N-dimethylaminophenyl)-ethanediyl] titanium dichloride in xenografted Ehrlich's ascites tumour

The effects of a new titanocene compound with an ansa ligand in the cyclopentadienyl rings, the 1,2-di(cyclopentadienyl)-1,2-di(p-NNdimethylaminophenyl)-ethanediyl] titanium dichloride (TITANOCENE X), on the growth and differentiation of granulocyte-macrophage progenitor cells [colony-forming unit-granulocyte-macrophage (CFU-GM)] and Natural killer (NK) cell activity in Ehrlich's ascites tumour (EAT)-bearing mice were studied. Myelosuppression concomitant with increased numbers of spleen CFU-GM was observed in tumour-bearing mice. Treatment of these animals with TITANOCENE X (2.5-50mg/kg/day) produced an increase in myelopoicsis, in a dose-dependent manner, and reduced spleen colony formation. In addition, the treatment of EAT-bearing mice with 3 doses of 20 or 50 mg/kg TITANOCENE X restored to normal values the reduced Natural killer cell function observed during tumour growth. In parallel, TITANOCENE X prolonged, in a dose-dependent manner, the survival of mice inoculated with Ehrlich's ascites tumour. The highest dose of 50 mg/kg prolonged in 50% the survival time of EAT-bearing mice, compared to non-treated tumour-bearing controls. In comparison with previous results from our laboratory addressing the effects of titanocenes on haematopoiesis, we observed with TITANOCENE X a similar effective profile as for bis(cyclopentadienyl) dithiocyanate titanium(IV), being both less effective than di(cyclopentadienyl) dichloro titanium(IV), since the latter not only prolonged, but also increased the rate of survival. These differences in efficacy may be due to the nature of the ansa-cyclopentadienyl ligand used in TITANOCENE X, since the C, bridge between the two cyclopentadienyl groups will increase the hydrolytic stability by an organometallic chelate effect. Also, the introduction of two dimethylamino substituents increases the water solubility of TITANOCENE X when compared to titanocene dichloride itself (c) 2006 Elsevier B.V. All rights reserved.

MARCKS functions as a novel growth/tumour suppressor in cells of melanocyte origin

Protein kinase C (PKC) plays a pivotal role in modulating the growth of melanocytic cells in culture. We have shown previously that a major physiological substrate of PKC, the 80 kDa myristoylated alanine-rich C-kinase substrate (MARCKS), can be phosphorylated in quiescent, non-tumorigenic melanocytes exposed transiently to a biologically active phorbol ester, but cannot be phosphorylated in phorbol ester-treated, syngeneic malignant melanoma cells. Despite its ubiquitous distribution, the function of MARCKS in cell growth and transformation remains to be demonstrated clearly. We report here that MARCKS mRNA and protein levels are down-regulated significantly in the spontaneously derived murine B16 melanoma cell line compared with syngeneic normal Mel-ab melanocytes. In contrast, the tumourigenic v-Ha-ras-transfonned melan-ocytic line, LTR Ras 2, showed a high basal level of MARCKS phosphorylation which was not enhanced by treatment of cells with phorbol ester. Furthermore, protein levels of MARCKS in LTR Ras 2 cells were similar to those expressed in Mel-ab melanocytes. However, in four out of six murine tumour cell lines investigated, levels of MARCKS protein were barely detectable. Transfection of B16 cells with a plasmid containing the MARCKS cDNA in the sense orientation produced two neomycin-resistant clones displaying reduced proliferative capacity and decreased anchorage-independent growth compared with control cells. In contrast, transfection with the antisense MARCKS construct produced many colonies which displayed enhanced growth and transforming potential compared with control cells. Thus, MARCKS appears to act as a novel growth suppressor in the spontaneous transformation of cells of melanocyte origin and may play a more general role in the tumour progression of other carcinomas.