Terrestrial edible land snails as vectors for geographic dissemination of Brachylaima species.

Cornu aspersum (= syn. Helix aspersa ) snails imported into NE Spain from Algeria and South Africa, and intended for human consumption via sale in public markets, were analyzed to assess their contribution to geographic dissemination of Brachylaima species. Prevalence and viability studies of metacercariae were performed on Algerian and South African Brachylaima adults. Morphometric studies were performed by measuring 16 variables in metacercariae and 18 variables in adults. Principal component analyses (PCA) were performed to assess the contribution of each variable in the separation of the different groups. A MANOVA test performed on morphometric data from Brachylaima llobregatensis and Brachylaima mascomai Algerian and South African adults, revealed a significant multivariate main effect (P < 0.001) and univariate effects in 13 variables (P ≤ 0.001). Pairwise comparisons revealed significant differences in 13 variables between B. mascomai and Algerian adults, as opposed to 3 variables (testis I width, testis II width, and egg width) when compared with B. llobregatensis. South African adults had significant differences in 5 variables (body length, oral sucker length, oral sucker width, egg length, and egg width) when compared with B. llobregatensis, as opposed to 1 variable (testis II width) when compared with B. mascomai. Results from PCA showed 2 different groups: B. llobregatensis/Algerian adults (overlapped) and B. mascomai/South African adults (overlapped). Imported edible C. aspersum specimens can contribute significantly to the geographic spread of Brachylaima species by harboring infective metacercariae which could easily infect animals, given their heteroxenous character. Brachylaima llobregatensis has previously been detected in NE Spain only, and now this species appears to be parasitizing C. aspersum in Algeria (North Africa). This geographic dispersion could be favored by commerce in terrestrial snails such as C. aspersum.

The novel Akt inhibitor Palomid 529 (P529) enhances the effect of radiotherapy in prostate cancer.

Radiotherapy (RT) is a common treatment for localised prostate cancer, but can cause important side effects. The therapeutic efficacy of RT can be enhanced by pharmacological compounds that target specific pathways involved in cell survival. This would elicit a similar therapeutic response using lower doses of RT and, in turn, reducing side effects. This study describes the antitumour activity of the novel Akt inhibitor 8-(1-Hydroxy-ethyl)-2-methoxy-3-(4-methoxy-benzyloxy)-benzo[c]chromen-6-one (Palomid 529 or P529) as well as its ability to decrease radiation-activated phospho-Akt (p-Akt) signalling in a prostate cancer model. P529 showed a potent antiproliferative activity in the NCI-60 cell lines panel, with growth inhibitory 50 (GI50) <35 microM. In addition, P529 significantly enhanced the antiproliferative effect of radiation in prostate cancer cells (PC-3). Analysis of signalling pathways targeted by P529 exhibited a decrease in p-Akt, VEGF, MMP-2, MMP-9, and Id-1 levels after radiation treatment. Moreover, the Bcl-2/Bax ratio was also reduced. Treatment of PC-3 tumour-bearing mice with 20 mg kg(-1) P529 or 6 Gy radiation dose decreased tumour size by 42.9 and 53%, respectively. Combination of both treatments resulted in 77.4% tumour shrinkage. Decreased tumour growth was due to reduced proliferation and increased apoptosis (as assessed by PCNA and caspase-3 immunostaining). Our results show the antitumour efficacy of P529 alone, and as a radiosensitiser, and suggest that this compound could be used in the future to treat human prostate cancer.

Identification of VEGF-regulated genes associated with increased lung metastatic potential: functional involvement of tenascin-C in tumor growth and lung metastasis.

Metastasis is the primary cause of death in patients with breast cancer. Overexpression of c-myc in humans correlates with metastases, but transgenic mice only show low rates of micrometastases. We have generated transgenic mice that overexpress both c-myc and vascular endothelial growth factor (VEGF) (Myc/VEGF) in the mammary gland, which develop high rates of pulmonary macrometastases. Gene expression profiling revealed a set of deregulated genes in Myc/VEGF tumors compared to Myc tumors associated with the increased metastatic phenotype. Cross-comparisons between this set of genes with a human breast cancer lung metastasis gene signature identified five common targets: tenascin-C(TNC), matrix metalloprotease-2, collagen-6-A1, mannosidase-alpha-1A and HLA-DPA1. Signaling blockade or knockdown of TNC in MDA-MB-435 cells resulted in a significant impairment of cell migration and anchorage-independent cell proliferation. Mice injected with clonal MDA-MB-435 cells with reduced expression of TNC demonstrated a significant decrease (P<0.05) in (1) primary tumor growth; (2) tumor relapse after surgical removal of the primary tumor and (3) incidence of lung metastasis. Our results demonstrate that VEGF induces complex alterations in tissue architecture and gene expression. The TNC signaling pathway plays an important role in mammary tumor growth and metastases, suggesting that TNC may be a relevant target for therapy against metastatic breast cancer.

[Significance of human mitochondrial genome in medicine]. / Importancia del genoma mitocondrial humano en Medicina.

Mitochondrial function is necessary for energy production, but also plays important roles in oxidative stress and apoptosis. Part of the complexes responsible for mitochondrial metabolism are encoded in mitochondrial DNA (mtDNA). Knowledge of the structure and function of mtDNA affords a better understanding of (1) the physiopathology of mitochondrial disorders; (2) the pattern of inheritance of mitochondrial diseases; and (3) the strategies that can be employed in the molecular diagnosis of these disorders. In the near future important breakthroughs are expected regarding the understanding of the cross-talk between nuclear and mitochondrial genomes, and its relevance in the biogenesis and maintenance of mitochondria.

Importancia del enoma mitocondrial humano en Medicina / Medical relevance of the human mitochondrial genome

La función mitocondrial es necesaria para la producción de energía, pero también juega un papel importante en el estrés oxidativo y en la apoptosis. Parte de los complejos responsables del metabolismo mitocondrial están codificados en el ADN mitocondrial (mtDNA). El conocimiento de la estructura y función del mtDNA ayuda a comprender (1) los rasgos fisio-patológicos de las enfermedades mitocondriales; (2) el patrón hereditario de las mismas; y (3) las estrategias de diagnóstico molecular que se pueden emplear en estas enfermedades. En el futuro próximo, se esperan importantes avances en la comprensión de las interacciones entre el genoma nuclear y el genoma mitocondrial, y su papel en la biogénesis y mantenimiento de las mitocondrias. (AU)

Actin cytoskeleton in adults and metacercariae of Brachylaima sp.

Experimental adults and natural metacercariae of Brachylaima sp. (Digenea: Brachylaimidae) were processed for transmission and scanning electron microscopy, for tetramethyl rhodamine isothiocyanate phalloidin fluorescence, conventional and confocal microscopy and for monoclonal anti-actin antibody immunoelectron microscopy, to describe the ultrastructural features of the tegument and to localize actin in several regions of the body. The general body tegument is spinous and contains membrane-bound disc-shaped biconcave vesicles in adults and metacercariae. Spines are flat and apically indented in the adult. A thick glycocalyx covers the body of the metacercaria. Direct fluorescence revealed filamentous actin in the spines and the subtegumental musculature of the adult. The subtegumental musculature comprises two systems consisting of an outer circular layer and an inner layer composed of cross-linked longitudinal and diagonal fibres. Immunoreactivity in adults and metacercariae revealed the presence of actin in the spines and subtegumental musculature but not in the tegumental matrix, interstitial fibrous material nor the parenchyma. Actin was detected in the dense collar and bulb matrix of the tegumental ciliated sensilla and, for the first time, in the apical cytoplasmatic projections of the digestive cell of the adult.

The occurrence of Cryptosporidium parvum and C. muris in wild rodents and insectivores in Spain.

Five rodent and two insectivore species were investigated for Cryptosporidium at seven sites in north-eastern Spain. Of the 442 animals studied, 82 Apodemus sylvaticus, 1 A. flavicollis, 5 Mus spretus, 1 Rattus rattus, 8 Clethrionomys glareolus and 13 Crocidura russula were infected with only C. parvum. Eleven A. sylvaticus and 2 C. glareolus were infected with only C. muris and 16 A. sylvaticus, 1 M. spretus and 2 C. glareolus showed mixed infections. Both cryptosporidial species were found in most study areas. No causal relationship was found between intrinsic host factors (age and sex) and the parasitic prevalence in the most captured host species (A. sylvaticus and C. russula). Extrinsic factors such as collection site of host, seasonality and covering vegetation exerted different influence on the prevalence of Cryptosporidium. Small mammals could become one of the most important sources of cryptosporidial oocysts in those areas where neither farm animals nor significant human activity are present. This is the first study to report the infection of M. spretus and C. russula by C. parvum and the first finding of C. muris in M. spretus.

Further report on Cryptosporidium in Barcelona zoo mammals.

The prevalence of fecal shedding of Cryptosporidium in 36 primates (21 species and subspecies) and 62 herbivores (36 species and subspecies) housed at the Barcelona zoo was studied. Cryptosporidial oocysts were found in stool samples of 14 Primate, 18 Artiodactyla, 2 Perissodactyla, and 1 Proboscidea species. None of them showed symptoms related to the parasite. Neither the sex nor the group condition (alone or in a group) of the animals studied appeared to be correlated with parasitic prevalence. The results extend the host species range of the protozoan to 18 new animals (6 Primate, 10 Artiodactyla, 1 Perissodactyla, and 1 Proboscidea species) and confirm the endemic status of Cryptosporidium at the Barcelona zoo. We conclude that maintenance of the parasitic endemic status is probably due to the presence of animal carriers as well as to the physical features of some facilities where oocysts could remain viable and infectious.

Ultrastructural study of spermatogenesis and the spermatozoon in Postorchigenes gymnesicus (Trematoda, Lecithodendriidae).

An ultrastructural study of spermatogenesis, spermiogenesis, and spermatozoa in Postorchigenes gymnesicus is presented. Cytoplasmic projections originating in nurse cells surround the spermatogonia, which are located at the periphery of the testes. Primary spermatocytes attached to a cytophore show synaptonemal complexes and a pair of centrioles. Spermiogenesis begins with the appearance of a cytoskeletal structure formed by an intercentriolar body and two perpendicular centrioles. An axoneme and a striated rootlet emerge from each centriole. The progressive rotation and fusion of both flagella with the median process occurs simultaneously with the migration of nucleus to the distal tip of the forming spermatozoon. The mature spermatozoon consists of three regions: (1) the nuclear region, containing the nucleus, one mitochondrion, two 9+1 axonemes, and cortical microtubules; (2) the intermitochondrial region, containing two axonemes; and (3) the mitochondrial region with another mitochondrion, two axonemes, cortical microtubules, and external ornamentation symmetrically and asymmetrically arranged coincidental with the cortical microtubules. Glycogen particles, absent in testicular cells, are abundant in the spermatozoon. Ultrastructural features of the non-nuclear region of the spermatozoon are specific for P. gymnesicus and are proposed to characterize the spermatozoon of digenean species. J. Morphol. 234:223-232, 1997. © 1997 Wiley-Liss, Inc.

Ultrastructural observations of the tegument of Postorchigenes gymnesicus (Digenea: Lecithodendriidae).

The tegument of Postorchigenes gymnesicus has been studied by scanning and transmission electron microscopy. The general body tegument is spinous and contains mitochondria, biconcave disc-shaped vesicles bounded by an unitary membrane and displaying a protein content, and scarce spherical bodies. The tegument covering specialized body regions is aspinous. Few vesicles were evident in the tegument covering the suckers and oesophagus, being more abundant in the metraterm and cirrus where the tegument is thicker. Laurer's canal has a thick tegument with sparse vesicles, mostly arranged close to the apical membrane. A direct association was evident between the basal lamina underlying the spines and the muscular subtegumental fibres, suggesting a motile character for the spine.