Merkel cell carcinoma of the lip: report of a case.
Explore the source record for details and available documents.
Aged↗
Biomedical subjects
G Orsini
Publications and source records attributed to G Orsini.
Idiopathic root resorption: report of a case.
A case of multiple idiopathic apical root resorption in a 26-yr-old female patient is presented. A review of the literature revealed that extensive idiopathic root resorption is unusual. Neither local nor systemic etiological factors were found in our case. Examination of parents and siblings did not reveal a familiar tendency. Radiographs and clinical evaluation showed a very poor prognosis for most of the teeth present in the mouth of our patient.
Adult↗
Hemangioma of the mandible presenting as a periapical radiolucency.
A case of an hemangioma of the mandible in a 53-yr-old female patient is presented. The lesion was removed, and no atypia or mitotic cells were found. The excision was curative, and the overall prognosis was excellent. A differential diagnosis of radiolucent periapical lesions of the mandibular symphysis is presented.
Diagnosis, Differential↗
Central (intraosseous) adenoid cystic carcinoma of the mandible: report of a case with periapical involvement.
Primary intraosseous salivary gland tumors are rare, with mucopidermoid carcinoma being the most frequent histotype. The authors present a case of adenoid cystic carcinoma, located in the mandibular incisor region, associated with pain. Endodontic treatment resulted in increased pain and progressive mandibular expansion. An apicoectomy was conducted, and an intraosseous adenoid cystic carcinoma was diagnosed at histological examination. The patient was treated by wide surgical resection, and is alive and well without recurrences or distant metastases 14 yr after the original diagnosis. The case presented herein calls attention to the preoperative clinical diagnosis of periapical lesions. Radiologically, focal sclerosing osteitis, cementoblastoma, cementifying and ossifying fibroma, periapical cemental dysplasia, complex odontoma, and calcifying epithelial odontogenic tumor should be considered in the differential diagnosis. In addition the unusual occurrence of salivary gland tumors in intraosseous location stresses the importance of systematic histological examination of any tissue sample obtained after endodontic procedures.
Apicoectomy↗
Peripheral ameloblastoma: a report of 2 cases.
Peripheral ameloblastoma (PA) is a rare odontogenic tumor most common in elderly patients. They are usually solitary; red or pink granular, nodular, or papillary lesions; up to 1.5 cm in diameter; and either not resorb bone or produce a shallow erosion. Peripheral ameloblastoma should be included in the differential diagnosis of soft tissue lumps on the gingiva or edentulous alveolus.
Ameloblastoma↗
Peripheral clear cell calcifying epithelial odontogenic tumor. Report of a case.
Calcifying epithelial odontogenic tumor (CEOT) is an uncommon, locally aggressive odontogenic tumor representing less than 1% of all odontogenic tumors. Clear cells have been described in CEOT, ameloblastomas, calcifying odontogenic cysts, lateral periodontal, and gingival cysts. It is not yet clear if the clear cell variants of the odontogenic tumors have a different biologic behavior, even if it seems that these tumors are more aggressive with an higher recurrence rate. The authors present a case of a peripheral clear cell CEOT (CCCEOT). It is a rare lesion with only 9 cases reported in the literature. The lesion was removed by excision and no recurrence was found after a 4-year follow-up.
Adult↗
[The effects of menopausal replacement therapy in women with uterine myomas].
BACKGROUND: The aim of this study was to compare the effects of two different therapies in menopausal women with uterine fibroids. METHODS: Thirty menopausal women with uterine fibroids were evaluated. They were randomized into two groups: the patients included in Group A were treated with transdermal hormonal therapy with 50 micrograms of ethynilestradiol and 5 mg of MAP; the patients in Group B with 2.5 mg of tibolone. The patients of both the groups have been treated for one year. Plasmatic levels of E2, FSH and LH were evaluated before and after treatment and the volume of fibroids was compared by transvaginal ultrasonography at the beginning of the study, after 6 months and after 1 year. RESULTS AND CONCLUSIONS: The results suggest that transdermal hormonal therapy increases significantly the volume of the fibroids while tibolone does not.
Antineoplastic Agents, Hormonal↗
Preparation and characterization of the recombinant selenomethionine analogue of insulin-like growth factor-I.
Insulin-like growth factor-I (IGF-I), a single-chain polypeptide consisting of 70 amino acids and 3 disulfide bridges, is a member of a class of growth factors that are involved in many proliferative and metabolic processes. To assist in solving the crystallographic three-dimensional structure, we have expressed a recombinant fusion protein precursor of IGF-I in a methionine auxotrophic strain of Escherichia coli grown in the presence of selenomethionine. An homogeneous preparation of selenomethionyl-IGF-I was then obtained by chemical cleavage of the fusion protein. The selenomethionine analogue of IGF-I was characterized by electrospray mass spectrometry, peptide mapping, analytical chromatography, and electrophoresis as well as by biological assays. The final preparation of IGF-I was found to incorporate about 90% of selenium and fully retained the functional activity.
Chromatography, High Pressure Liquid↗
The bacteriophage T4 AsiA protein: a molecular switch for sigma 70-dependent promoters.
The AsiA protein, encoded by bacteriophage T4, inhibits Esigma70-dependent transcription at bacterial and early-phage promoters. We demonstrate that the inhibitory action of AsiA involves interference with the recognition of the -35 consensus promoter sequence by host RNA polymerase. In vitro experiments were performed with a C-terminally labelled sigma factor that is competent for functional holoenzyme reconstitution. By protease and hydroxyl radical protein footprinting, we show that AsiA binds region 4.2 of sigma70, which recognizes the -35 sequence. Direct interference with the recognition of the promoter at this locus is supported by two parallel experiments. The stationary-phase sigma factor containing holoenzyme, which can initiate transcription at promoters devoid of a -35 region, is insensitive to AsiA inhibition. The recognition of a galP1 promoter by Esigma70 is not affected by the presence of AsiA. Therefore, we conclude that AsiA inhibits transcription from Escherichia coli and T4 early promoters by counteracting the recognition of region 4.2 of sigma70 with the -35 hexamer.
Amino Acid Sequence↗
The interaction between the AsiA protein of bacteriophage T4 and the sigma70 subunit of Escherichia coli RNA polymerase.
The AsiA protein of bacteriophage T4 binds to the sigma70 subunit of Escherichia coli RNA polymerase and plays a dual regulatory role during T4 development: (i) inhibition of host and phage early transcription, and (ii) coactivation of phage middle-mode transcription, which also requires the T4 DNA binding transcriptional activator, MotA. We report that the interaction between AsiA and sigma70 occurs with a 1:1 stoichiometry. When preincubated with RNA polymerase, AsiA is a potent inhibitor of open complex formation at the lac UV5 promoter, whereas it does not perturb preformed open or intermediate promoter complexes. DNase I footprinting and electrophoretic mobility shift analyses of RNA polymerase-DNA complexes formed at the T4 early promoter P15.0 show that AsiA blocks the initial RNA polymerase binding step that leads to the formation of specific closed promoter complexes. A contrasting result is obtained on the T4 middle promoter PrIIB2, where AsiA stimulates the formation of both closed complexes and open complexes. Therefore, we propose that AsiA modulates initial DNA binding by the RNA polymerase, switching promoter usage at the level of closed complex formation.
Bacterial Proteins↗
Protein purification in multicompartment electrolyzers with isoelectric membranes.
Preparative purification of proteins under isoelectric conditions is reviewed, with particular regard to novel equipment, a multicompartment electrolyzer with isoelectric membranes, which can capture any desired protein into an isoelectric trap as the sole, ultra-pure component. This novel machine is based on the Immobiline chemistry, i.e. the novel generation of non-amphoteric buffers, based on the chemistry of acrylamides, which can be insolubilized onto polyacrylamide supports. After a description of the instrument and of its performance, a number of protein purification protocols are described, leading to truly homogeneous (by the most stringent criterion of surface charge) protein fractions. Such a high charge purity has been found to be often a fundamental prerequisite for the growth of protein crystals. Interfacing the electrolyzer with mass spectrometry has permitted the decoding of the structure of minor components generated from a parental molecule, especially ones having a higher pI. It was found that these species were often generated either by proteolytic cleavage or by the formation of a trisulphide bridge between two Cys residues. A unique application of the electrolyzer is finally described: its use as an immobilized enzyme reactor under an electric field. The performance of this reaction is outstanding, in that the kinetic parameters of the immobilized enzyme are identical to those of a free enzyme form.
Amino Acid Sequence↗
Recombinant human IL-2 is cytotoxic to oligodendrocytes after in vitro self aggregation.
Interleukin 2 (IL-2) is a cytokine produced by activated T cells that plays a crucial role in the immune response and exerts multiple functions in different tissues including the nervous system. The present study was carried out to investigate the effect of recombinant human IL-2 (rhIL-2) on the survival of differnet glial cells type and of cortical neurons in culture. The results demonstrate that rhIL-2 is selectively cytotoxic to oligodendrocytes only if preincubated in aqueous solution (1200 U/ml) for at least two days before being added to the culture. Other glial and neuronal cells were unaffected. The cytotoxic effect was temperature- and concentration-dependent occurring only when rhIL-2 was reincubated at 37 degrees C and was dose-dependently neutralized by antibodies raised against IL-2 indicating that an immunoreactive IL-2 like compound is the active principle. Polyacrilamide gel electrophoresis under native (PAGE) and denaturing (SDS-PAGE) conditions and gel filtration analysis of the rhIL-2 incubated solution suggest that rhIL-2 is cytotoxic to oligodendrocytes only after association into soluble high weight molecular aggregates.
Animals↗
Hydroxylamine-induced cleavage of the asparaginyl-glycine motif in the production of recombinant proteins: the case of insulin-like growth factor I.
Hydroxylamine-induced cleavage at the asparaginyl-glycine dipeptide site inserted between the two moieties of recombinant fusion proteins has been used at both the analytical and the preparative scale to obtain the mature protein. In this study a model protein containing a fusion precursor of insulin-like growth factor I was used to investigate the influence of the operating conditions on the cleavage reaction and the formation of undesired side products such as hydroxamate and deamidated analogs. Moreover, the stability of the cleavage site toward deamidation was examined and a chemometric study performed to define the effect of the reaction conditions on the cleavage yield and on the formation of side products.
Amino Acid Sequence↗
Investigation on minor degraded derivatives of the recombinant hirudin variant HM2 from Hirudinaria manillensis isolated by isoelectric focusing in multicompartment electrolyzers.
On isoelectric focusing in immobilized pH gradients (IPG) a preparation of recombinant hirudin from Hirudinaria manillensis, purified to homogeneity, was found to still contain a total of 5% minor components: three with higher pI values (pIs 4.10, 4.25 and 4.31), one with a lower pI value (pI 3.98) as compared with the main form (pI 4.03). Multicompartment electrolyzers with isoelectric membranes and micropreparative IPG gel slabs allowed the recovery of pure fractions of such minor components, which were further characterized by electrospray mass spectra, limited proteolysis, and sequence analysis. All four minor isoforms were found to be cleavage products of the parent, full-length hirudin molecule (molecular mass 6797 Da), as follows: the pI 4.31 (5032 Da) had lost sixteen amino acids from the N-terminus, the pI 4.25 (6212 Da) lacked five amino acids from the C-terminus, the pI 4.10 (2980 Da) was a cleavage product at residue Cys37, and the pI 3.98 (6610 Da) lacked the dipeptide Val-Ser at the N-terminus. Combining the extreme resolving power of IPGs with the high accuracy of mass spectra was found to be an attractive strategy in decoding post-synthetic modifications often encountered in r-DNA proteins.
Amino Acid Sequence↗
Detection of traces of a trisulphide derivative in the preparation of a recombinant truncated interleukin-6 mutein.
A new mutein of interleukin-6, called delta 22-IL-6 Cys 3,4, characterized by the deletion of the first 22 amino acids at the N-terminal end and by the substitution of the first two cysteines (Cys23 and Cys29) with serine residues, was produced in Escherichia coli and was found to maintain the structural and functional properties of the human native form. A partially purified preparation still showed in isoelectric focusing a minor acidic component (pI 6.10) and a more basic component (pI 6.70), the native form having a pI of 6.56. This preparation was further fractionated in a multi-compartment electrolyser with isoelectric membranes, which allowed the collection of the more alkaline species for characterization. Mass spectra of the pI 6.70 form gave an additional mass of 32 atomic mass units (amu), suggesting the addition of two oxygen atoms (a potential oxidation of two methionine residues to sulphoxide). However, the five methionine residues in this higher pI form were identified after enzymatic hydrolysis and peptide mapping and were found to be in a reduced state. In addition, the pI 6.70 form was quickly converted into the native form by mild reductive treatment. On digestion and fingerprinting, the peptide from residues 50 to 65 of the pI 6.70 species (containing the only two cysteine residues of the molecule) exhibited a more hydrophobic behaviour in reversed-phase high-performance liquid chromatography and retained a mass increase of 32 amu. These experimental findings more likely suggest the addition of an extra sulphur atom to the only disulphide bridge to give an unusual protein trisulphide molecule.
Amino Acid Sequence↗
Bacteriophage T4 MotA and AsiA proteins suffice to direct Escherichia coli RNA polymerase to initiate transcription at T4 middle promoters.
Development of bacteriophage T4 in Escherichia coli requires the sequential recognition of three classes of promoters: early, middle, and late. Recognition of middle promoters is known to require the motA gene product, a protein that binds specifically to the "Mot box" located at the -30 region of these promoters. In vivo, the asiA gene product is as critical for middle mode RNA synthesis as is that of the motA gene. In vitro, AsiA protein is known to loosen the sigma 70-core RNA polymerase interactions and to inhibit some sigma 70-dependent transcription, presumably through binding to the sigma 70 subunit. Here we show that, in vitro, purified MotA and AsiA proteins are both necessary and sufficient to activate transcription initiation at T4 middle promoters by the E. coli RNA polymerase in a sigma 70-dependent manner. AsiA is also shown to inhibit recognition of T4 early promoters and may play a pivotal role in the recognition of all three classes of phage promoters.
Bacteriophage T4↗
Structure, stability and biological properties of a N-terminally truncated form of recombinant human interleukin-6 containing a single disulfide bond.
A mutant species of the 185-residue chain of human interleukin-6 lacking 22-residues at its N-terminus and with a Cys-->Ser substitution at positions 45 and 51 was produced in Escherichia coli. The 163-residue protein des-(A1-S22)-[C45S, C51S]interleukin-6, containing a single disulfide bridge, formed inclusion bodies. Mutant interleukin-6 was solubilized in 6 M guanidine hydrochloride, subjected to oxidative refolding and purified to homogeneity by ammonium sulfate precipitation and hydrophobic chromatography. The purity of the mutant species was established by electrophoresis, isoelectrofocusing and reverse-phase HPLC and its structural identity was checked by N-terminal sequencing of both the intact protein and several of its proteolytic fragments. Electrospray mass spectrometry analysis of mutant interleukin-6 gave a molecular mass of 18,695 +/- 2 Da in excellent agreement with the calculated value. Circular dichroic, fluorescence emission and second-derivative ultraviolet absorption spectra indicated that mutant interleukin-6 maintains the overall secondary and tertiary structure, as well as stability characteristics, of the recombinant wild-type human interleukin-6. The urea-induced unfolding of mutant interleukin-6, monitored by circular dichroic measurements in the far-ultraviolet region, occurs as a highly cooperative process with a midpoint of denaturation at 5.5 M urea. The data of the reversible unfolding of mutant interleukin-6 mediated by urea were used to calculate a value of 20.9 +/- 0.4 kJ.mol-1 for the thermodynamic stability of the protein at 25 degrees C in the absence of denaturant. The biological activity of mutant interleukin-6 was evaluated in vitro by the hybridoma proliferation assay, and in vivo by measuring thrombopoiesis in monkeys. Dose/response effects of the mutant were comparable or even higher than those of the wild-type protein. Overall the results of this study show that mutant interleukin-6 is a biologically active cytokine, which could find practical use as a therapeutic agent.
Amino Acid Sequence↗
Characterization of proteins by sequential isoelectric focusing on immobilized pH gradients and electrospray mass spectrometry.
The coupling of isoelectric focusing on immobilized pH gradients (IPG) with electrospray-mass spectrometry (ES-MS) was applied to the characterization of proteins according to two different and important properties, such as net surface charge and molecular mass. From a technical point of view, these methods are complementary, since ES-MS requires ion-free samples as usually supplied by isoelectric focusing on IPGs. This report describes the experiments carried out on model proteins to demonstrate the feasibility of the sequential application of these two techniques for the characterization of proteins. A minimum of 5 micrograms protein was needed for good signal by mass spectrometry. The following proteins were studied: myoglobin, truncated interleukin-6-mutein, recombinant cytochrome c551 and insulin-like growth factor I. Extraction from the IPG matrix was carried out in 70% acetonitrile/30% water/0.05% trifluoroacetic acid either by passive diffusion or by centrifugation through a 0.22 micron Amicon membrane, with protein recoveries of 80-85%.
Animals↗