Primary cardiac and pericardial neoplasms are rare lesions and include both benign and malignant histologic types. Myxoma is the most frequent primary cardiac neoplasm, but other benign tumors include papillary fibroelastoma, rhabdomyoma, fibroma, hemangioma, lipoma, and paraganglioma. Cardiac sarcoma represents the second most common primary cardiac neoplasm. Lymphoma can also affect the heart primarily. Pericardial tumors that affect the heart include benign teratomas and malignant mesotheliomas. Patients affected with cardiac or pericardial neoplasms often present with cardiovascular compromise or embolic phenomena and exhibit cardiomegaly at chest radiography. Benign cardiac tumors typically manifest as intracavitary, mural, or epicardial focal masses, whereas malignant tumors demonstrate invasive features and may involve the heart diffusely. Benign lesions can usually be successfully excised, but patients with malignant lesions have an extremely poor prognosis.
ResearchCryopreserved spermatozoa demonstrate reduced conception rates compared with fresh spermatozoa when used for artificial insemination. The preliminary stage of cryopreservation of spermatozoa involves cooling to 5ЊC, during which spermatozoa experience a capacitation-like change, which may be partially responsible for the reduced conception rate observed. The aim of this study was to determine the nature of these capacitation-like changes and how much this process resembles true capacitation. Boar spermatozoa, cooled to 5ЊC and rewarmed to physiological temperatures (39ЊC), were compared with spermatozoa capacitated in Tyrode's complete medium (TALP) for 2 h at 39ЊC. Fluorescent probes, and SDS-PAGE and western blotting were used to visualize events known to occur during capacitation in vitro. Chlortetracycline staining of membrane domains and Fluo-3 detection of changes in intracellular free calcium by flow cytometry in cooled and re-warmed spermatozoa showed similarities to those of capacitated spermatozoa. Alterations to lipid bilayer fluidity assessed by merocyanine fluorescence staining and intracellular signalling pathways detected by tyrosine phosphorylation of cooled and re-warmed spermatozoa, did not completely reflect the changes detected during capacitation in vitro. Thus, cooling spermatozoa to 5ЊC results in a similar endpoint to that observed in capacitated cells in terms of reactive membranes and changes in intracellular ion concentrations, which may account for their comparable functionality. However, these modifications are not completely analogous and should not be considered true capacitation, but rather a by-passing of the capacitation process.
ResearchAfter mating, mammalian spermatozoa are transported to the lower oviductal isthmus. Spermatozoa are sequestered at the isthmus by attaching and interacting with oviductal epithelial cells, hence forming a sperm reservoir. In several mammalian species, specific carbohydrates mediate spermoviductal epithelial cell binding. A quantitative in vitro free cell bioassay was developed to investigate the involvement of carbohydrate recognition in pig spermoviductal epithelial cell interactions. This assay was validated. The sensitivity of the assay was such that it was possible to discriminate between different sperm concentrations and sperm-oviductal epithelial cell co-incubation periods, spermatozoa with damaged plasma membranes and epithelial cells of non-reproductive origin. Optimal conditions were used to incubate spermatozoa and oviductal epithelial cells in the presence of six hexose sugars at concentrations of 0, 2, 10 and 50 mmol l -1 . A significant (P р 0.05) reduction in the binding of spermatozoa to the oviductal epithelium was detected with 2, 10 and 50 mmol maltose l -1 , 50 mmol lactose l -1 and 50 mmol mannose l -1 . These findings support the hypothesis that attachment of pig spermatozoa to oviductal epithelium before fertilization is mediated by carbohydrate recognition.
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