Solid pseudopapillary tumor (SPT) is an indolent neoplasm with low-grade biological aggressiveness, making surgical treatment successful despite its large size.
Pancreatic serous microcystic adenomas (SCAs) are rare, benign tumors with a striking female preference. Virtually no information is available about chromosomal or genetic anomalies in this disease. We performed extensive molecular characterization of 21 cases of formalin-fixed, paraffin-embedded sporadic SCAs consisting in genome-wide allelic loss analysis with 79 microsatellite markers covering all 22 autosomes, assessment of microsatellite instability, and mutational analysis of the VHL, K-ras, and p53 genes in nine cases for which frozen tissue was available. Although no case showed microsatellite instability of the type seen in mismatch repair-deficient tumors, a relatively low fractional allelic loss of 0.08 was found. Losses on chromosome 10q were the most frequent event in SCAs (50% of cases), followed by allelic losses on chromosome 3p (40% of cases). Moderately frequent losses (>25% of cases) were found on chromosomes 1q, 2q, and 7q. The VHL gene, located on chromosome 3p, had somatic inactivating mutations in two of nine cases (22%), whereas no mutations were found in either K-ras or p53, in agreement with the finding that all 21 cases stained negative for p53 by immunohistochemistry. Our study indicates that the involvement of chromosomal arms 10q and 3p is characteristic of SCAs and that the VHL gene is involved in a subset of sporadic cases.
p63, a member of the p53 family, is involved in the survival and differentiation of reserve/stem cells in different epithelia. To unveil the possible role of p63 in thymic physiology and pathology, we investigated the expression of p63 isoforms in normal thymus, thymomas and other mediastinal tumours. All samples were analysed using immunohistochemistry with three different antibodies: 4A4 antibody recognising all p63 isoforms, p40 antibody reacting only with truncated dominant-negative isoforms (DeltaN-p63) and H-129 antibody recognising all alpha-isoforms. Reverse-transcription polymerase chain reaction (RT-PCR), and real-time PCR analyses were performed on RNA extracted from frozen samples of four thymomas and two primary-mediastinal large-B-cell lymphoma (PMLBCL). In normal thymus, DeltaN-p63alpha was expressed in all cortical and medullary epithelial cells, with decreasing intensity in Hassall's corpuscles. This phenotype was conserved in neoplastic transformation since all 54 investigated thymomas (World Health Organization types A, AB, B1, B2, B3, C) expressed DeltaN-p63alpha (virtually 100% cells). The predominance of DeltaN-p63alpha isoform mRNA was confirmed by real-time PCR. Among other mediastinal tumours, DeltaN-p63alpha was only expressed in those displaying either a stratified epithelial component (teratomas) or epidermoid differentiation (lung carcinoma). Among lymphomas, T-cell-precursor lymphomas did not express p63, whereas most PMLBCL expressed TA-p63alpha (7/8).
Our findings indicate that care should be taken when energy expenditure during climbing is estimated from the f vs [Formula: see text] relationship determined in the laboratory. The level of climbing experience significantly affects the energy cost of exercise. Last, the similar aerobic demands of cycling and climbing at peak exercise, suggest that maximum [Formula: see text]may play an important role in climbing performance. Specific training methodologies should be implemented to improve aerobic power in climbers.
Extrafollicular B-cell activation is the morphological correlate of rapid B-cell responses that do not involve the germinal centres. It is pathogenetically heterogeneous, comprising primary responses that occur prior to, or independent of, germinal centre reaction or memory cell activation in recall responses.
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