Modulation of phosphofructokinase (PFK) from Setaria cervi, a bovine filarial parasite, by different effectors and its interaction with some antifilarials

<p>Abstract</p> <p>Background</p> <p>Phosphofructokinase (ATP: D-fructose-6-phosphate-1-phosphotransferase, EC 2.7.1.11, PFK) is of primary importance in the regulation of glycolytic flux. This enzyme has been extensively studied from mammalian sources but relatively less attention has been paid towards its characterization from filarial parasites. Furthermore, the information about the response of filarial PFK towards the anthelmintics/antifilarial compounds is lacking. In view of these facts, PFK from <it>Setaria cervi</it>, a bovine filarial parasite having similarity with that of human filarial worms, was isolated, purified and characterized.</p> <p>Results</p> <p>The <it>S. cervi </it>PFK was cytosolic in nature. The adult parasites (both female and male) contained more enzyme activity than the microfilarial (Mf) stage of <it>S. cervi</it>, which exhibited only 20% of total activity. The <it>S. cervi </it>PFK could be modulated by different nucleotides and the response of enzyme to these nucleotides was dependent on the concentrations of substrates (F-6-P and ATP). The enzyme possessed wide specificity towards utilization of the nucleotides as phosphate group donors. <it>S. cervi </it>PFK showed the presence of thiol group(s) at the active site of the enzyme, which could be protected from inhibitory action of para-chloromercuribenzoate (p-CMB) up to about 76% by pretreatment with cysteine or β-ME. The sensitivity of PFK from <it>S. cervi </it>towards antifilarials/anthelmintics was comparatively higher than that of mammalian PFK. With suramin, the Ki value for rat liver PFK was 40 times higher than PFK from <it>S. cervi</it>.</p> <p>Conclusions</p> <p>The results indicate that the activity of filarial PFK may be modified by different effectors (such as nucleotides, thiol group reactants and anthelmintics) in filarial worms depending on the presence of varying concentrations of substrates (F-6-P and ATP) in the cellular milieu. It may possess thiol group at its active site responsible for catalysis. Relatively, 40 times higher sensitivity of filarial PFK towards suramin as compared to the analogous enzyme from the mammalian system indicates that this enzyme could be exploited as a potential chemotherapeutic target against filariasis.</p

Juvenile intraoral mucoepidermoid carcinoma

Purpose: The purpose of this study was to assess the clinicopathologic, treatment, and outcome features of a series of intraoral mucoepidermoid carcinomas (MECs) affecting children and adolescents. Patients and Methods: Between 1953 and 2006, from 102 intraoral MECs, 9 (8.8%) affected patients under 18 years of age. Clinical data were retrieved from the medical records, the microscopical slides reviewed, and the tumors graded in low, intermediate, and high grades of malignancy. Results: Five cases occurred in females and 4 in males, with a mean age of 14 years. Seven cases affected the palate, and the other 2 Occurred in the buccal mucosa and retromolar area. Most patients presented in initial clinical stages and all cases were surgically treated. Microscopically, 7 tumors were classified as histologically low-grade malignancies. Eight patients did not show tumor recurrence after a mean follow-up of 98.4 months (range, 4 to 278 months), and I patient developed local and neck recurrences and died after 15 years of initial treatment. Conclusion: juvenile MEC are rare tumors, most occur in the palate and present as a low-grade malignancy with excellent prognosis. Although rare, MEC should be considered in the differential diagnosis of intraoral submucous nodule in young patients. (c) 2008 American Association of Oral and Maxillofacial Surgeons.66230831

Juvenile intraoral pleomorphic adenoma: report of five cases and review of the literature

The aim of this study is to report on five cases of intraoral pleomorphic adenoma (PA) in patients under 18 years of age and to review the literature. Intraoral salivary gland tumours were reviewed in two Brazilian institutions and five cases of PA in patients under 18 years of age were found. Clinical data were obtained from the medical records and paraffin-embedded tissues were sectioned for proliferating cell nuclear antigen (PCNA) and p53 immunohistochemical analysis. Four patients were female and one was male; two cases affected the palate, two the upper lip and one the tongue. All five patients were treated surgically and after long follow-up periods no recurrences were observed. Tumour cells were weakly positive for PCNA and negative for p53. PA should be considered in the differential diagnosis of submucosal nodules in young patients. In youngsters, PA seems to have similar biological characteristics as in adults, with low recurrence rates after surgical resection.31327327

Electroweak parameters of the z0 resonance and the standard model

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