282 research outputs found
Heredity and colorectal cancer
No full textColorectal cancer is the second leading cause of death from malignancies in Western Countries. In spite of advances in treatment, little change in survival has been accomplished in last decades and this mandates greater importance to prevention and early detection. Although dietary factors have received primary attention familial clustering suggests that susceptibility to KCR is inherited. Hereditary colorectal cancer can arise on Familial Adenomatous Polyposis (HCC) or not on polyposis (HNPCC) and members of these families are at high risk of such neoplasias. Anyway, even in "sporadic" forms of KCR first-degree relatives have a 2 to 3-fold increased risk of the same cancer. The most desirable screening protocol would be a simple procedure involving only a blood test to identify gene defect by molecular biology techniques. Unfortunately, this is not practically possible, for lack of specific genetic alterations, out of FAP, and only the study of family history can enable targeted surveillance and cost-effective management strategies
Update on epidemiology and risk factors of colorectal carcinoma [Attualità in tema di epidemiologia e fattori di rischio del carcinoma colo-rettale]
No full textEtiology of colorectal cancer is not completely clear. Epidemiologic studies, especially those on migrant populations, demonstrate the importance of environmental factors, particularly dietary, in cancerogenesis. Anyway, familial aggregation within a given population shows that genetic factors play an important role. General risk factors are represented by age, sex, physical activity... while some pathologies increased the risk of developing KCR or are frankly precancerous (adenomas, ulcerative colitis, Crohn's disease...)
Blood gastrin and colorectal neoplasms
No full textGastrin has a trophic effect on the mucosa of the gastrointestinal tract and seems to have the potential for promoting colonic cancerogenesis through a chronic stimulation of the epithelial proliferation. Plasma gastrin has been reported to be elevated in patients with colorectal neoplasms. The aim of the present study was to verify this observation. Presurgical serum levels of gastrin were compared between 49 patients with colorectal neoplasms and 47 controls hospitalized for other surgical lesions. Results show significantly higher gastrin levels of case group than controls: 72.72 + 85.41 vs. 46.79 + 24.09 pg/ml (p < 0.05), and provide support for the hypothesis of a gastrin-stimulated neoplastic growth enhancing at the same time the potential therapeutic role of reducing gastrin secretion
Papillary Thyroid carcinoma in three siblings with familial adenomatous polyposis
No full textThe authors report three siblings (two sisters and their aunt, aged 20, 22 and 36, respectively) with familial adenomatous polyposis (FAP) and papillary thyroid carcinoma. After diagnosis of FAP, a single, non palpable nodule was revealed in each patient by routine screening ultrasonography of the gland, The diagnosis of papillary carcinoma was made by fine-needle-aspiration biopsy of the nodules and confirmed by histologic examination of surgical specimens. A review of the literature reveals about 40 reports of such an association, that is considered not fortuitous. Nevertheless, in this family the association seems to be a distinctive, clinical feature of the syndrome, affecting three out of five members intensively screened for extracolonic lesions
Non-seagrass meadow sedimentary facies of the Pontinian Islands, Tyrrhenian Sea: A modem example of mixed carbonate-silicielastic sedimentation
No full textThe soft bottom of the Mediterranean continental shelf is characterized by a heterozoan skeletal assemblage (sensu [James, N.P., 1997. The cool-water carbonate depositional realm. In: James, N.P., Clarke, J. (Eds), Cool-water Carbonates. Spec. Publ. Soc. Sediment. Geol., vol. 56, pp. 1 -20.]). Although the contemporary presence of terrigenous and skeletal carbonate sediments has been well established [Tortora, P., 1996. Depositional and erosional coastal processes during the last postglacial sea-level rise: an example from the Central Tyrrhenian continental shelf (Italy). J. Sed. Res. 66, 391-405.; Fornos, J.J., Ahr, W.M., 1997. Temperate carbonates on a modem, low-energy, isolated ramp: the Balearic Platform, Spain. Journal of Sedimentary Research, 67, 364-373.; Fornos, J.J., Ahr, W.M., 2006. Present-day temperate carbonate sedimentation on the Balearic Platform, western Mediterranean: compositional and textural variation along a low-energy isolated ramp. In: Pedley, H.M., Carannante, G. (Eds.) 2006, Cool-water Carbonates: Depositional Systems and Palaeoenvironmental Controls. Geological Society, London, Special Publications, 255, pp. 121-135], the interactions between carbonate and terrigenous-siliciclastic sedimentation has not been documented well enough. A total of 33 surface sediment samples from the Pontinian shelf (Tyrrhenian Sea, central Mediterranean) have been analysed. Sampling stations range from 15 to 250 mwd (meter water depth) and are located along five transects (PonzaW, PonzaNW, Ponza NE, Ponza E, Zannone), plus four samples collected around Palmarola Island. Sectors colonized by seagrass meadows have not been sampled. A total of 6 sedimentary facies (F) and 10 microfacies (mo have been recognized by using component analyses, grain size percentage, sorting, carbonate content and authigenic mineralization rate. These facies and trucrofacies represent the Pontian Islands shelf sedimentation, in the interval between the upper infralittoral and the epibathyal zones that represent shelf-break and upper slope sedimentation. The Maerl facies (F4a,b; mf4a,b) and the skeletal sands (F2a,b -1 mf2a 1, mf2a2, mf2b) fall within the circalittoral zone. The circalittoral zone in the water depth interval between 82 m and 112 m display relict facies (F6, mf6). Finally facies F5 (Siliciclastic sands) includes subfacies F5b (mf5b), located in the circalittoral zone at depths of 49 to 101 mwd and restricted to the western and eastern sectors of Ponza, and subfacies F5a in the upper infralittoral zone (15 mwd/25 mwd) where erosional processes prevail. Carbonate content analyses indicate that maximum carbonate production on the Pontinian shelf took place in the 60-80 mwd interval. Facies F4 (Maerl) represents the environment characterized by the highest carbonate production rates. In the Pontian area siliciclastic-carbonate mixing took place in the infralittoral zone and in the lower circalittoral zone. In the infralittoral zone erosional processes on the rocky shoreline produced lithoclasts and vulcanoclastic deposits that were reworked by wave-induced near-shore currents. In the lower circalittoral zone the prolific production by photic biota (red algae) ends, while skeletal remains of the aphotic environment mixes with planktonic sediments characterized by low carbonate values. Sand (63 mu m-2 mm) is the dominant grain size class, however gravel-dominated facies (F4 Maerl) are present in water depths (50 to H 2 mwd) which are significantly below the storm wave base. Glauconite mineralization appears on the Pontinian shelf from 50 mwd and increases in abundance along the deeper bathymetries. The compositional characteristics of relict facies F6 shows the concurrence of biota assemblages of the infralittoral and circalittoral zones, likely representing the record of the last Holocene transgressive event (18 ky) and expressed by the overlapping of components of different environments. (c) 2007 Elsevier B.V. All rights reserved
Germline mutations of mismatch repair genes (MMR) in patients with HNPCC-LIKE syndrome: preliminary results
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Chromosomal rearrangement, reproductive isolation and speciation in Mammals. The case of Mus musculus.
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