ABSTRACT
Subcutaneous Panniculitis-like T-cell Lymphoma (SPTL) is a rare cutaneous neoplasm of mature cytotoxic T cells, first described in 1991 by Gonzalez et al. The incidence of SPTL in Asian countries ranges from 2.3% to 3%. In Malaysia, only 5 cases were reported from 2001 to 2004 in Hospital Kuala Lumpur, Malaysia. SPTL typically presents as skincoloured or erythematous subcutaneous nodules, most often on the extremities and trunk, but it can also involve the face, back and neck. Diagnosis of SPTL is made based on correlation of clinical findings and subcutaneous tissue biopsy along with immunohistochemical staining patterns.
Subject(s)
Lymph Nodes/pathology , Lymphoma, T-Cell/diagnosis , Panniculitis/diagnosis , Skin Neoplasms/diagnosis , Biopsy , Diagnosis, Differential , Humans , Male , Subcutaneous Tissue , Young AdultABSTRACT
p53 has a crucial role in governing cellular mechanisms in response to a broad range of genotoxic stresses. During DNA damage, p53 can either promote cell survival by activating senescence or cell-cycle arrest and DNA repair to maintain genomic integrity for cell survival or direct cells to undergo apoptosis to eliminate extensively damaged cells. The ability of p53 to execute these two opposing cell fates depends on distinct signaling pathways downstream of p53. In this study, we showed that under DNA damage conditions induced by chemotherapeutic drugs, gamma irradiation and hydrogen peroxide, p53 upregulates a novel protein, proline-rich acidic protein 1 (PRAP1). We identified functional p53-response elements within intron 1 of PRAP1 gene and showed that these regions interact directly with p53 using ChIP assays, indicating that PRAP1 is a novel p53 target gene. The induction of PRAP1 expression by p53 may promote resistance of cancer cells to chemotherapeutic drugs such as 5-fluorouracil (5-FU), as knockdown of PRAP1 increases apoptosis in cancer cells after 5-FU treatment. PRAP1 appears to protect cells from apoptosis by inducing cell-cycle arrest, suggesting that the induction of PRAP1 expression by p53 in response to DNA-damaging agents contributes to cancer cell survival. Our findings provide a greater insight into the mechanisms underlying the pro-survival role of p53 in response to cytotoxic treatments.
Subject(s)
Apoptosis , DNA Damage , Pregnancy Proteins/metabolism , Tumor Suppressor Protein p53/metabolism , Cell Cycle , Cell Line, Tumor , Cell Survival , Humans , Introns , Pregnancy Proteins/genetics , Tumor Suppressor Protein p53/geneticsABSTRACT
This paper summarizes the results of a series of studies on the various factors that affect the leaching of lead from unplasticized poly(vinyl chloride) (UPVC) pipes. Factors that were studied include temperature, pH and extractants. Results showed that, for a given UPVC pipe, the rate of leaching of lead depended primarily on temperature and the nature of extractants. While the rate of leaching of lead was quite low with distilled water, it was very much enhanced by the presence of low concentration of anions such as Cl(-), HPO inf4 (sup2-) HCO inf3 (sup-) , NO inf3 (sup-) , SO inf4 (sup2-) and EDTA. EDTA, being a strong complexing agent, was most effective. Rates of leaching were found to be higher at elevated temperature except in the cases of HPO inf4 (sup2-) and EDTA. Effect of pH was not pronounced. The temperature at which the UPVC pipes were extruded was found to affect the rate of leaching of lead. Pipes extruded at 190°C were found to have lower rate of leaching than those extruded at 180°C and 170°C. Analysis of the pipes by Scanning Electron Microscopy showed that the distribution of lead in the pipes extruded at 190°C was more uniform than those extruded at 170°C.
ABSTRACT
The Sr/Ca ratios in molluscan shells in Singapore waters were measured using the X-ray fluorescence (XRF) technique. Our results show that the Sr/Ca ratio varies greatly among different species. However, within the same species, this ratio is practically the same for samples collected from sites close together but varies significantly for samples from sites far apart. Furthermore, this study shows that whole shell analysis using the XRF technique is simple and quick and that its application to environmental monitoring seems feasible.
