Validation of automated docking programs for docking and database screening against RNA drug targets

The increasing awareness of the essential role of RNA in controlling viral replication and in bacterial protein synthesis emphasizes the potential of ribonucleoproteins as targets for developing new antibacterial and antiviral drugs. RNA forms well defined three-dimensional structures with clefts and binding pockets reminiscent of the active sites of proteins. Furthermore, it precedes proteins in the translation pathway; inhibiting the function of a single RNA molecule would result in inhibition of multiple proteins. Thus, small molecules that bind RNA specifically would combine the advantages of antisense and RNAi strategies with the much more favorable medicinal chemistry of small-molecule therapeutics. The discovery of small-molecule inhibitors of RNA with attractive pharmacological potential would be facilitated if we had available effective computational tools of structure-based drug design. Here, we systematically test automated docking tools developed for proteins using existing three-dimensional structures of RNA-small molecule complexes. The results show that the native structures can generally be reproduced to within 2.5 angstroms more than 50-60% of the time. For more than half of the test complexes, the native ligand ranked among the top 10% compounds in a database-scoring test. Through this work, we provide parameters for the validated application of automated docking tools to the discovery of new inhibitors of RNA function.     

Blood lead levels, clinico-pathological findings and erythrocyte metabolism in dogs from different habitats

Biological markers of lead exposure were measured in 20 dogs from five different habitats chosen on the basis of the degree of anthropogenic influence. None of the dogs had clinical signs of lead poisoning. Compared to controls, blood lead concentrations were significantly higher in dogs from industrial areas, confirming the role of lead emissions in environmental pollution and the possible role of dogs as biomonitors of lead exposure in these areas. Whole blood lead concentrations were similar in dogs living in urban and rural areas, probably due to "indirect" lead sources and due to decreased urban lead contamination. As in humans, individual variability was detected. No significant correlation between clinico-pathological changes (hematology, clinical chemistry, Delta-aminolevulinic acid dehydratase activity and other intra-erythrocytic metabolic parameters) and lead concentration were observed. Our findings suggest dogs can be useful as sentinels of environmental lead exposure.     

MSCRAMM--targeted vaccines and immunotherapy for staphylococcal infection

Hospital-acquired infections are associated with prolonged hospitalization and an increase in both healthcare costs and resources. Advances in sophisticated medical procedures, an increase in the number of immunocompromised patients, and the continued emergence of resistance to conventional antibiotic therapy has created a need for alternative strategies to prevent and treat infectious bacterial diseases. Immunoprevention and immunotherapy targeting microbial surface components recognizing adhesive matrix molecule (MSCRAMM) proteins are viable approaches to potentially impede bacterial adherence, eliminate colonization, and minimize hematogenous dissemination, thereby halting the inception and progression of infection. This review summarizes several investigative efforts where staphylococcal MSCRAMM proteins are being utilized in the design of subunit vaccines and in the development of innovative therapeutic strategies that could be implemented following the onset of infection to manage severe and life-threatening disease.     

Herbal mixtures in the traditional medicine of eastern Cuba

Herbal mixtures in the traditional medicine of Eastern Cuba. Traditional herbal mixtures in Eastern Cuba are investigated through interviews with 130 knowledgeable people and traditional healers of the provinces of Santiago de Cuba and Guantánamo. One hundred seventy plant species and other products are used in 199 formulas, galones being the more complex. Cocos nucifera L. (Arecaceae), Bidens pilosa L. (Asteraceae), Cissus sicyoides L. (Vitaceae), Erythroxylum havanense Jacq. (Erythroxylaceae) and Stachytarpheta jamaicensis (L.) Vahl. (Verbenaceae) are the species most frequently cited. The ecological distribution of the taxa and cultural and anthropological aspects of mixtures are highlighted; particularly American and African influences that have shaped local knowledge about plant combinations are discussed.     

Molecular mechanisms associated with chromosomal and microsatellite instability in sporadic glioblastoma multiforme

OBJECTIVE: Two chromosomal instability (CIN) pathways are described in glioblastoma multiforme (GBM), type 1 and type 2, which can be observed in up to 70% of the cases. Microsatellite instability (MSI) plays a pathogenic role in sporadic cancers such as colon, gastric and endometrial carcinomas with deficient mismatch repair (MMR). We aimed to perform a comprehensive analysis of the relationship between CIN and MSI mechanisms in sporadic glioblastomas. METHODS: 129 GBMs were examined (109 newly diagnosed and 20 relapses) investigating MSI, immunohistochemical expression of MMR proteins as well as sequencing and promoter methylation of hMLH1. We characterized the molecular changes frequently correlated with CIN in MSI+ GBMs and compared them with 26 microsatellite-stable tumors. RESULTS: Low-level MSI was observed in 11 of 129 (8.5%) cases and was higher in relapses than in primary GBMs (25 vs. 5.5%, p = 0.027). High-level MSI was not found in any case. A deficient expression of MLH1 and PMS2 without hMLH1 inactivation was observed only in one giant cell GBM. 55% of the MSI+ GBMs showed a profile which did not correspond to one of the known CIN pathways. An inverse association was observed between MSI and mutations of both p53 and PTEN. CONCLUSIONS: Our data suggest that CIN and MSI contribute to the genomic instability in GBMs via independent pathways. Since MSI was significantly more frequent in relapses, it might play a role in the malignant progression of GBM.     

Immunohistochemical and molecular study of radiation-induced multiple meningiomas with pleural and pulmonary metastasis

In the present study, the telomerase activity and the putative alterations of genes involved in cell-cycle control (p53, Fas and pRb) were investigated in a radiation-induced meningioma with multiple recurrences and pleural-pulmonary metastases (the patient, a 34-year-old male, had a history of carcinoma of the tongue of testicular lymphocytic lymphoma). Expression of VEGF and vasculature pattern were also studied. Expression of VEGF, pRb and p53 were evaluated by immunohistochemistry on formalin-fixed, paraffin-embedded samples of the tumor. VEGFmRNA was determined by competitive PCR. Fas, FasL and hTERT were evaluated by RT-PCR. Telomerase activity was examined by the TRAP assay. An intense vascularization was observed, supported by high expression of VEGFmRNA (isoforms 121 and 165). pRb and p53 were overexpressed. Fas was undetectable with PCR, whereas FasL was positive. Furthermore, the lesion showed an elevated telomerase activity (TPG, 22), according to the high expression of hTERT. These findings emphasized that even among generally benign neoplasms, such as meningiomas, some highly malignant tumors may develop, as in our case, in which several mechanisms were activated in the cancer progression to guarantee the immortalization of cellular clones (angiogenic phenomenon, activation of telomerase and of anti-apoptotic mechanisms) and the blood spread. Thus, the data illustrate the importance of searching for genetic aberrations (which are a hallmark of malignancy) in meningiomas, as predictive and reliable factors of the possibility to recur and to metastasize.     

External beam irradiation in the palliation of bone metastases: a practice analysis among Sicilian Departments of Radiation Oncology

BACKGROUND: In the treatment of bone metastases, the choice of radiation fractionation, total radiation dose, delivery technique, and imaging studies before treatment varies among radiation oncologists. Surveys on this issue, using case scenarios, have been published by groups from Europe, North America, and Australia-New Zealand. Our objective was to analyze retrospectively the "real" practice in nine radiotherapy centers located in Sicily. METHOD: A questionnaire including 17 items was distributed to 30 practicing radiation oncologists working in seven departments of four Sicilian cities (Messina, Catania, Ragusa and Palermo) during a meeting of the Sicilian Division of the Associazione Italiana Radioterapia Oncologica (AIRO). Participants were asked to answer the questions using a card for every patient treated with external beam irradiation from 1 January to 31 December, 2000. RESULTS: Six centers returned the questionnaires; 332 cards were valuable for a total of 5644 responses. All six responding departments used linear accelerators for treatment delivery. The most common dose fractionation was 30 Gy in 10 fractions and the most common technique used was opposed parallel local fields. Before the start of irradiation a bone scan was performed in 325 of the 332 (98%) patients treated and CT and/or MRI was performed in 320 (96%); surprisingly, standard roentgenograms were used in only 142 of 332 patients (42.8%). CONCLUSION: The "real" radiation practice for bone metastases in the region of Sicily confirms the results of the previously reported international surveys: there is a clear preference for fractionated treatment and local field therapy. The results of randomized studies, which demonstrated both the efficacy and the feasibility of a single 6-8 Gy fraction in the palliation of bone metastases, have little or no impact on the pattern of practice.