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Frequent Phenomenon (frequent + phenomenon)
Selected AbstractsCOX-2 mRNA expression in esophageal squamous cell carcinoma (ESCC) and effect by NSAIDDISEASES OF THE ESOPHAGUS, Issue 1 2008X. Liu SUMMARY., To investigate cyclooxygenase-2 (COX-2) mRNA expression in human esophageal squamous cell carcinoma and the effect of a non-steroidal anti-inflammatory drug (NSAID) on it, in order to explore the mechanism of COX-2 in esophageal squamous cell carcinoma (ESCC) carcinogenesis and the ability of NSAID to prevent or treat ESCC. Frozen specimens of human ESCC and adjacent normal esophageal squamous epithelium pairs (n = 22) were examined for COX-2 mRNA expression by reverse-transcription polymerase chain reaction (RT-PCR). After incubation with aspirin (a non-selective COX inhibitor) or Nimesulide (a selective COX-2 inhibitor), the proliferation status of two human esophageal squamous cancer cell lines, EC-9706 and EC-109, was quantified by 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyltetrazolium bromide assay. The expression of COX-2 mRNA in these cells was detected by RT-PCR. COX-2 mRNA was expressed in 12 of 22 (54.5%) ESCC tissue samples, but it was undetectable in all the specimens of adjacent normal esophageal squamous epithelium COX-2 mRNA expression. Both aspirin (5,20 mmol/L) and Nimesulide (0.1,0.8 mmol/L) inhibited EC-9706 cell line proliferation and suppressed its COX-2 mRNA expression dose-dependently. However, only aspirin (5,20 mmol/L) could inhibit proliferation in the EC-109 cell line and suppress COX-2 mRNA expression. Nimesulide (0.1,0.8 mmol/L) could neither inhibit EC-109 cell growth nor suppress COX-2 mRNA expression. COX-2 mRNA expression is a frequent phenomenon in human ESCC tissue samples and plays an important role in the carcinogenesis of ESCC. NSAID may be useful in the chemoprevention and therapy of human ESCC and its effects are likely to be mediated by modulating COX-2 activity. [source] HMGA2 and the p19Arf -TP53-CDKN1A axis: A delicate balance in the growth of uterine leiomyomas,GENES, CHROMOSOMES AND CANCER, Issue 8 2010Dominique Nadine Markowski Pathogenetically, uterine leiomyomas (ULs) can be interpreted as the result of a monoclonal abnormal proliferation of myometrial cells. Oncogene-induced senescence (OIS) is a frequent phenomenon in premalignant lesions that leads to a growth arrest mainly by the activation of two potent growth-inhibitory pathways as represented by p16Ink4a and p19Arf. The relevance of OIS for the development of UL has not been addressed, but HMGA2, encoded by a major target gene of recurrent chromosomal abnormalities in UL, has been implicated in the repression of the Ink4a/Arf (CDKN2A) locus. This prompted us to examine if HMGA2 contributes to the growth of leiomyomas by repressing this locus. Contrary to the expectations, we were able to show that generally ULs express significantly higher levels of p19Arf mRNA than myometrium and that UL with 12q14,15 rearrangements showed higher expression levels than UL with other cytogenetic aberrations. Furthermore, the finding of a significant correlation between the expressions of p19Arf and CDKN1A shows that p19Arf triggers senescence rather than apoptosis in UL. Furthermore, the expression levels of HMGA2, p19Arf, and CDKN1A were found to be correlated with the size of the tumors, indicating that an enhanced growth potential is counterbalanced by the p19Arf pathway. Mechanistically, the UL may thus execute a program already present in their cell of origin, where it is activated to protect the genome, for example, in the case of enhanced proliferation. In summary, the results identify the p19Arf -TP53-CDKN1A pathway as a major player in the growth control and genomic stability of uterine fibroids. © 2010 Wiley-Liss, Inc. [source] He Came, He Saw, He Stayed.INTERNATIONAL MIGRATION, Issue 2 2000Guest Worker Programmes, the Issue of Non-Return Critics of guest worker programmes have pointed out that many temporary workers do not return home when their contracts expire and thus end up swelling the ranks of undocumented workers in a host country. This article argues that this outcome is not inevitable. Whether or not guest workers return home or stay behind depends to a large extent on how the guest worker programme is administered. By comparing the US Bracero Program with the Canadian Mexican Agricultural Seasonal Workers' Program, it is shown that three aspects of programme administration account for why so many Braceros stayed in the US illegally, while almost all temporary workers employed in Canada return to Mexico at the end of the season. The three aspects are recruitment policies and procedures, enforcement of employment and housing-related minimum standards, and the size of the programme. It is suggested that the administration of the programme, in turn, reflects various interests that shape the State's position on foreign labour. Whereas in the US the Bracero Program was tailored to meet the needs of agribusinesses, the Canadian state responds to a wider variety of interests, including its own concern with the definition of ideal citizenship, as well as the need to protect domestic workers and the Mexican Government's interest in assisting those who are most needy. Additionally, unlike the US, where braceros were employed mainly in agribusinesses, in Canada Mexicans are brought to work on family farms. While desertion was a frequent phenomenon in the US, the paternalistic relationships that Canada-bound workers develop with their employers make desertion unlikely. [source] Hypercalcaemia of malignancy: an undiagnosed and undertreated diseaseJOURNAL OF INTERNAL MEDICINE, Issue 1 2001O. Lamy Lamy O, Jenzer-Closuit A, Burckhardt P (University Hospital, Lausanne, Switzerland). Hypercalcaemia of malignancy: an undiagnosed and undertreated disease. J Intern Med 2001; 250: 73,79. Background.,Hypercalcaemia of malignancy, a relatively frequent phenomenon, seems to be insufficiently recognized and treated. Its symptoms are not specific, but they affect the quality of life. Methods.,A prospective study to analyse the influence of symptoms caused by hypercalcaemia on the decision of the admitting physician, the motivation for treatment, and the effect of the treatment on the given symptoms in hospitalized patients with oncologic disease in progression, where confounding causes of similar symptoms such as cerebral metastasis, radiotherapy, treatment with opioids, etc., were excluded. Results.,A total of 71 patients, mean age 65 + 11 years, fulfilled the strict inclusion criteria. About 42% were hospitalized because of symptoms caused by hypercalcaemia, but none of the medical reports mentioned hypercalcaemia as reason for hospitalization. Specific antihypercalcaemic therapy was given to only 37% of patients, and only 25% got an adequate rehydratation. Antihypercalcaemic treatment was guided by the severity of hypercalcaemia (>3.00 mmol L,1), not by the symptoms. Polyuria-polydipsia, nausea-vomiting and constipation were correlated with hypercalcaemia. These symptoms, as well as confusion-stupor and bone pains improved significantly when calcaemia was normalized. Patients with calcaemia normalized returned home most frequently (P < 0.03). Conclusions.,Malignant hypercalcaemia remains mostly undiagnosed in medical praxis. Specific treatment occurs in too small fractions of the patients. As the normalization of calcaemia significantly improves the symptoms because of hypercalcaemia and the quality of life, rapid rehydration and specific calcium lowering treatments should be part of palliative measures in all patients with malignant hypercalcaemia. [source] Dynamics of intracohort cannibalism in cultured fishAQUACULTURE RESEARCH, Issue 7 2002E Baras Abstract Cannibalism is a frequent phenomenon in fish, especially in culture environments where fish are unable to escape predation via habitat segregation or migration. Not all cultured fish species start to exhibit cannibalism at the same age or size, nor is cannibalism equally intense in different species or life stages. Predator to prey size ratios vary substantially between species and life stages, chiefly because cannibalism is governed by gape size limitations and allometric growth of mouthparts. The development of sense organs, hard body parts, swimming and escape capacities in both the predator and the prey also influence prey size selectivity. The dynamics of cannibalism are influenced by these, as well as by environmental, factors that have effects on feed intake, growth depensation and facilitate or complicate the displaying of cannibalistic behaviour. Knowledge about cannibalistic behaviour and the logistics of cannibalism along with environmental enhancement are prerequisites for the mitigation of cannibalism in aquaculture. Also, within the context of strain selection, it is of importance to determine whether cannibals are natural-born killers or just lottery winners. These factors are discussed, chiefly as they apply to intracohort cannibalism. In addition, guidelines are suggested for cannibalistic risk assessment, and methods for mitigation of cannibalism are discussed. [source] | ||||||||||