RESUMEN
PURPOSE: The aim of the study is to present the first results of molecular characterization of thalassaemias in Valencian Community and their relationship with the haematological parameters. PATIENTS AND METHODS: The study includes 87 thalassemic patients: 30 alpha-thalassaemias, 40 beta-thalassaemias and 17 delta beta-thalassaemias. The molecular alterations were studied in white cell blood DNA, either following different PCR methods or by testing the digestion of the amplified PCR products with selective restriction enzymes. RESULTS: The molecular characterization of beta-thalassaemias was achieved in 94% of the subjects, being the transition C-->T in CD-39 the most frequent (44%) of the mutations studied. 94% of the delta beta-thalassaemias studied corresponded to the delta beta-Spanish type. All the alpha thalassaemias characterized (64%) corresponded to the -alpha 3.7 deletion. The reamining 36% were negative for the alpha 0 deletions --MED, --20.5, or the non deletional mutations Hph I and NocI. DISCUSSION: In the Valencian Community, like what has been described for the beta-thalassaemias in other Mediterranean regions of Spain (Barcelona, Granada and Mallorca), a high incidence in C-->T transition in CD-39 was observed, in contrast with central and south-western regions of Spain, where the G-->A IVS-I-1 is the most frequent mutation. Our study supports that the IVS-I-6 mutations is the one with lower repercussions on the haematological parameters. Our study confirms the Spanish type of delta beta-thalassaemia as the most frequent in the Valencian Community, and that the 3.7 kb alpha deletion is the most frequent mutation for the alpha-thalassaemia, although alpha thalassaemia is also the poorly characterized form of thalassaemia.
Asunto(s)
Mutación , Talasemia alfa/genética , Talasemia beta/genética , Análisis Mutacional de ADN , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Femenino , Humanos , Masculino , Fenotipo , Reacción en Cadena de la Polimerasa , Eliminación de Secuencia , España/epidemiología , Talasemia alfa/epidemiología , Talasemia beta/epidemiologíaRESUMEN
We analysed in mice why the salivary gland extract (SGE-2) from Ornithodoros erraticus and O. moubata induce a protective response with Freund's adjuvants (FAs) in swine while the saliva, in natural conditions, does not. Such protection has been ascribed to the fact that administration of SGE-2 plus FAs permits the recognition of certain salivary components that under natural conditions are not immunogenic. The present findings confirm this hypothesis since in mice, which are unable to recognize the above components, the SGE-2-FAs do not induce any protection. We rule out the possibility that the cause of this could lie in the absence of prostaglandin E2 in the SGE-2 (vs saliva) since it is not present in either fluid. Neither could it be due to a change in antibody isotype since those induced by parasites bites and by the SGE-2-FAs are the same (IgG2a > IgG1 > IgG2b; not IgG3, IgM, IgE). No IgG2a were seen when the SGE-2 were administered alone or with alum or ricin. It is therefore suggested that first responses would be Th1 and the second ones Th2, although no IgE is seen in the latter responses either. The parasites do not require complement to feed; by contrast, they block its activation and skin cellular infiltrates, such as those elicited by IL-8, MCP-1 and C5a, do not affect them, regardless of the presence or not of antitick antibodies.
Asunto(s)
Garrapatas/inmunología , Compuestos de Alumbre/farmacología , Animales , Anticuerpos/inmunología , Antígenos/inmunología , Western Blotting , Proteínas del Sistema Complemento/inmunología , Dinoprostona/análisis , Conducta Alimentaria , Adyuvante de Freund/farmacología , Isotipos de Inmunoglobulinas/clasificación , Isotipos de Inmunoglobulinas/inmunología , Ratones , Ricina/farmacología , Saliva/química , Porcinos , Garrapatas/metabolismo , Vacunas/inmunologíaRESUMEN
On pig farms, elimination of the argasid ticks acting as reservoirs and vectors for African swine fever greatly favours the eradication of this disease. The elimination of Ornithodoros erraticus involves many problems, most of which could be easily solved by the development of an anti-O. erraticus vaccine. With a view to developing this vaccine, we have tested the protective value of the immune response induced in swine by seven 'concealed' antigens and one soluble salivary gland extract. The latter extract was also prepared from Ornithodoros moubata specimens and tested against this tick. Our results indicate that the immune response elicited by the concealed antigens has no protective value against O. erraticus. The immune response induced by the salivary gland extracts against adults of O. erraticus and O. moubata was apparent in a reduced ingestion of blood (40-60%; P < 0.01) (except in males of O. erraticus) and in a significant decrease (40-60%; P < 0.01) in fecundity in 100% of the females of both species. The good results obtained with salivary antigens, which in situations of natural contact have no protective value, are attributed to the fact that when these antigens are injected with adjuvants, the immune system recognizes certain salivary components (probably those which enable the parasite to feed) which it does not recognize under natural conditions of exposure.
Asunto(s)
Fiebre Porcina Africana/inmunología , Fiebre Porcina Africana/prevención & control , Enfermedades por Picaduras de Garrapatas/veterinaria , Garrapatas/inmunología , Vacunas , Animales , Reservorios de Enfermedades/veterinaria , Ensayo de Inmunoadsorción Enzimática , Femenino , Inmunización/veterinaria , Glándulas Salivales/inmunología , Porcinos , Enfermedades por Picaduras de Garrapatas/inmunología , Enfermedades por Picaduras de Garrapatas/prevención & controlRESUMEN
For some time it has been known that the tick Ornithodoros erraticus might be one of the causes of the persistence of African swine fever in the Iberian Peninsula since its introduction in 1960. In the province of Salamanca serological methods have been used to study the relationship between the presence of the tick in different townships and the outbreaks of African swine fever in these townships between 1987 and 1992. The results showed that there was a statistically significant association between the presence of the parasite and the persistence of African swine fever. In townships without O erraticus traditional methods of control are in most cases enough to avoid new outbreaks of the disease, but in areas with O erraticus the traditional methods should be reinforced by other methods for preventing contact between pigs and the parasite.
Asunto(s)
Fiebre Porcina Africana/epidemiología , Fiebre Porcina Africana/parasitología , Vectores Artrópodos , Garrapatas , Animales , Anticuerpos/sangre , Prevalencia , España/epidemiología , Porcinos , Garrapatas/inmunologíaRESUMEN
Ornithodoros erraticus is the European vector of African Swine Fever. It is therefore essential to know on which pig farms the tick is present in order to prevent contact with swine. Currently, studies are being made to ascertain this through the detection of anti-O. erraticus antibodies in the sera of swine, using three extracts from the salivary glands of the parasite (SGE): a complete extract (SGE-1), a soluble antigens extract (SGE-2), and a tissue antigens extract (SGE-3). The results of the present work show that SGE-2 gives the best differentiation between swine bitten by O. erraticus and unbitten swine in the enzyme-linked immunosorbent assay (ELISA). Using this extract, an optical density (OD) five-fold higher than the basal OD indicates that the pigs carry anti-O. erraticus antibodies. A serological study carried out in Salamanca with 8083 sera from 1756 pig farms revealed the presence of the parasite on 135 farms. However, during this study we noticed that some sera of unbitten animals gave false-positive reactions. Western blot analysis of SGE-2 of these false-positive sera demonstrated the same bands (except for two) as the real anti-O. erraticus sera. We observed, in ELISA and Western blot analysis, that such false-positive sera only recognised carbohydrate epitopes on SGE-2. This reactivity disappeared on deglycosylated SGE-2 (SGE-2-P). Therefore, SGE-2-P is the antigen that confers the greatest specificity to serology. In this study it was also observed that the low levels of anti-O. erraticus antibodies found in some cases may be because the swine were bitten some months previously on a different farm or that the current farm harboured only a few specimens of O. erraticus, so pig-tick contact is unlikely and hence the pigs either only develop a primary response or the time between contacts is very long and the levels of antibodies fall. Since pigs could be bitten on a different farm, the presence of low levels of anti-O. erraticus antibodies in pig sera do not necessarily indicate the presence of the tick on the farm where sampling was carried out.