439 research outputs found

    Essential Programs and Services Review: The Special Education Funding Model

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    The purpose of this document is to review the special education funding component of the Essential Programs and Services funding model. This component was first implemented in 2005 -2006 and first reviewed in 2007-08. In order to establish a context for this second review, the sections below include an overview of special education and funding in the U.S. and in Maine

    The requirement of matrix ATP for the import of precursor proteins into the mitochondrial matrix and intermembrane space

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    The role of ATP in the matrix for the import of precursor proteins into the various mitochondrial subcompartments was investigated by studying protein translocation at experimentally defined ATP levels. Proteins targeted to the matrix were neither imported or processed when matrix ATP was depleted. Import and processing of precytochrome b2, (pb2), a precursor carrying a bipartite presequence, into the intermembrane space was also strongly dependent on matrix ATP. Preproteins, consisting of 220 or more residues of pb2 fused to dihydrofolate reductase, showed the same requirement for matrix ATP, whereas the import of shorter fusion proteins (up to 167 residues of pb2) was largely independent of matrix ATP. For those intermembrane-space-targeted proteins that did need matrix ATP, the dependence could be relieved either by unfolding these proteins prior to import or by introducing a deletion into the mature portion of the protein thereby impairing the tight folding of the cytochrome b5 domain. These results suggest the following: (a) The import of matrix-targeted preproteins, in addition to a membrane potential ΔΨ, requires matrix ATP [most likely to facilitate reversible binding of mitochondrial heat-shock protein 70 (mt-Hsp70) to incoming precursors], for two steps, securing the presequence on the matrix side of the inner membrane and for the completion of translocation; (b) in the case of intermembrane-space-targeted precursors with bipartite signals, the function of ATP/mt-Hsp70 is not obligatory, as components of the intermembrane-space-sorting pathway may substitute for ATP/mt-Hsp70 function (however, if a tightly folded domain is present in the precursor, ATP/mt-Hsp70 is indispensable); (c) unfolding on the mitochondrial surface of tightly folded segments of preproteins is facilitated by matrix-ATP/mt-Hsp70

    A crucial role of the mitochondrial protein import receptor MOM19 for the biogenesis of mitochondria

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    The novel genetic method of "sheltered RIP" (repeat induced point mutation) was used to generate a Neurospora crassa mutant in which MOM19, a component of the protein import machinery of the mitochondrial outer membrane, can be depleted. Deficiency in MOM19 resulted in a severe growth defect, but the cells remained viable. The number of mitochondrial profiles was not grossly changed, but mutant mitochondria were highly deficient in cristae membranes, cytochromes, and protein synthesis activity. Protein import into isolated mutant mitochondria was decreased by factors of 6 to 30 for most proteins from all suborganellar compartments. Proteins like the ADP/ATP carrier, MOM19, and cytochrome c, whose import into wild-type mitochondria occurs independently of MOM19 became imported normally showing that the reduced import activities are solely caused by a lack of MOM19. Depletion of MOM19 reveals a close functional relationship between MOM19 and MOM22, since loss of MOM19 led to decreased levels of MOM22 and reduced protein import through MOM22. Furthermore, MOM72 does not function as a general backup receptor for MOM19 suggesting that these two proteins have distinct precursor specificities. These findings demonstrate that the import receptor MOM19 fulfills an important role in the biogenesis of mitochondria and that it is essential for the formation of mitochondria competent in respiration and phosphorylation

    Pleomorphic Adenoma of the Parotid: Extracapsular Dissection Compared with Superficial Parotidectomy—A 10-Year Retrospective Cohort Study

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    The purpose of this study was to investigate the complication rates and effectiveness of extracapsular dissection compared with superficial parotidectomy for pleomorphic adenomas of the parotid gland from 2002 to 2012. The authors carried out a retrospective cohort study of 198 patients with pleomorphic adenomas of the parotid gland. Extracapsular dissection (ED) or superficial parotidectomy (SP) was performed. The recurrence rate and complications of the two surgical techniques were measured with a univariate analysis of each variable using the appropriate statistical analysis (chi-squared test or t-test). A total of 198 patients were enrolled between January 2003 and December 2012. The study included 97 females (48.99%) and 101 males (51.01%) whose mean age was 50.97 years (range 14–75). The type of surgery performed was ED in 153 patients (77.27%, 80 males and 73 females) and SP in 45 patients (22.73%, 21 males and 24 females). The mean follow-up time was 61.02 +/− 4.9 months for the patients treated with ED and 66.4 +/− 4.5 months for the patients treated with SP. Transient facial nerve injury and facial paralysis were significantly more frequent after SP than after ED (P=0.001 and P=0.065, resp.). No significant differences in capsular rupture, recurrence, and salivary fistula were observed after SP or ED: 2.2% versus 3.9%, 2.2% versus 3.3%, and 2.2% versus 0.65%, respectively. Extracapsular dissection may be considered the treatment of choice for pleomorphic adenomas located in the superficial portion of the parotid gland because this technique showed similar effectiveness and fewer side effects than superficial parotidectomy

    Myoepithelioma of the parotid gland: A case report with review of the literature

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    Myoepithelioma is a rare tumor of the salivary glands belonging to a distinct category of neoplasms according to World Health Organization. It represents about 1% of all tumors that develop in the salivary glands. Generally the majority of myoepitheliomas are benign but malignant transformation can take place in untreated or recurrent cases. We present a case of a rare myoepithelioma of the left parotid gland, with review of literature. Keywords: Parotid gland, Salivary glands myoepithelioma, Benign salivary glands tumors, Myoepithelioma, Spindle cells myoepitheliom

    An Engineered Yeast Efficiently Secreting Penicillin

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    This study aimed at developing an alternative host for the production of penicillin (PEN). As yet, the industrial production of this β-lactam antibiotic is confined to the filamentous fungus Penicillium chrysogenum. As such, the yeast Hansenula polymorpha, a recognized producer of pharmaceuticals, represents an attractive alternative. Introduction of the P. chrysogenum gene encoding the non-ribosomal peptide synthetase (NRPS) δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine synthetase (ACVS) in H. polymorpha, resulted in the production of active ACVS enzyme, when co-expressed with the Bacillus subtilis sfp gene encoding a phosphopantetheinyl transferase that activated ACVS. This represents the first example of the functional expression of a non-ribosomal peptide synthetase in yeast. Co-expression with the P. chrysogenum genes encoding the cytosolic enzyme isopenicillin N synthase as well as the two peroxisomal enzymes isopenicillin N acyl transferase (IAT) and phenylacetyl CoA ligase (PCL) resulted in production of biologically active PEN, which was efficiently secreted. The amount of secreted PEN was similar to that produced by the original P. chrysogenum NRRL1951 strain (approx. 1 mg/L). PEN production was decreased over two-fold in a yeast strain lacking peroxisomes, indicating that the peroxisomal localization of IAT and PCL is important for efficient PEN production. The breakthroughs of this work enable exploration of new yeast-based cell factories for the production of (novel) β-lactam antibiotics as well as other natural and semi-synthetic peptides (e.g. immunosuppressive and cytostatic agents), whose production involves NRPS's
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