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S Selleri

Publications and source records attributed to S Selleri.

At least 19 recordsLinked to original sources
PubMed2006

Improved synthesis of the peripheral benzodiazepine receptor ligand [11C]DPA-713 using [11C]methyl triflate.

Recently, the pyrazolopyrimidine, [11C] N,N-Diethyl-2-[2-(4-methoxyphenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl]acetamide (DPA-713) has been reported as a new promising marker for the study of peripheral benzodiazepine receptors with positron emission tomography. In the present study, DPA-713 has been labelled from the corresponding nor-analogue using [11C]methyl triflate (CH3OTf). Conditions for HPLC were also modified to include physiological saline (aq. 0.9% NaCl)/ethanol:60/40 as mobile phase making it suitable for injection. The total time of radiosynthesis, including HPLC purification, was 18-20 min. This reported synthesis of [11C]DPA-713, using [11C]CH3OTf, resulted in an improved radiochemical yield (30-38%) compared to [11C]methyl iodide (CH3I) (9) with a simpler purification method. This ultimately enhances the potential of [11C]DPA-713 for further pharmacological and clinical evaluation. These improvements make this radioligand more suitable for automated synthesis which is of benefit where multi-dose preparations and repeated syntheses of radioligand are required.

Acetamides↗
PubMed2005

Caveolin-1 is expressed on multipotent cells of hair follicles and might be involved in their resistance to chemotherapy.

BACKGROUND: Caveolin-1 is the principal protein that composes caveolae, which are vesicular invaginations present on the plasma membrane of different cell types. Caveolae are involved in a variety of cellular functions including regulation of proliferation rate and resistance to chemotherapeutic drugs. Chemotherapy frequently induces alopecia which is reversible most probably due to the low proliferative rate of hair follicle stem cells and due to the expression of proteins which confer resistance. OBJECTIVES: Using a specific animal model and immunohistochemistry, we analysed the expression of both caveolin-1 and the cell proliferation marker beta-catenin, at different stages of the hair follicle cycle, both before and after doxorubicin (DXR) -induced alopecia. METHODS: Seven-week-old C57BL/6 mice were depilated in order to synchronize hair follicle cycle in the anagen phase. Chemotherapy with DXR 15 mg kg(-1) was used to induce alopecia. Control and treated mice were then sacrificed at precise time points and caveolin-1 expression in hairs at different stages of the cycle were analysed by immunohistochemistry. By double immunofluorescence, colocalization of caveolin-1 and cytokeratin-15 was confirmed in the bulge region. The state of proliferation of cells composing hair follicle was assessed by beta-catenin immunohistochemistry. RESULTS: Caveolin-1 was expressed by the cells of the bulge area, the multipotent compartment of the hair follicle, during all phases of growth (anagen), regression (catagen) and resting (telogen). During the anagen phases, nuclear beta-catenin labelling was not observed in bulge cells, but rather in the deeper portion of the follicle. Damaged hair follicles from DXR-treated mice presented bulge cells which still expressed caveolin-1, suggesting that this protein might play a role in their drug resistance. As expected, no beta-catenin nuclear staining was detectable in DXR-treated hair follicles, indicating the complete lack of proliferative processes. The differential localization of caveolin-1 and beta-catenin suggests that the mutually exclusive expression of these proteins is useful for correct hair regrowth, whether during the physiological cycle or after chemotherapy-induced alopecia. CONCLUSIONS: Expression of caveolin-1 within the multipotent cell compartment of the hair follicle can explain the resistance of bulge cells to many chemotherapeutics, suggested by the reversibility of chemotherapy-induced alopecia.

Alopecia↗
PubMed2005

Single-mode regime of square-lattice photonic crystal fibers.

The modal cutoff of square-lattice photonic crystal fibers with a finite number of air-hole rings has been accurately investigated to our knowledge for the first time. By analyzing the leaky behavior of the second-order mode, we have obtained a phase diagram that describes the regions of single-mode and multimode operation as well as the endlessly single-mode regime. Furthermore, starting from these results, we have obtained the cutoff normalized frequency according to two different formulations of the V parameter previously adopted for fibers with a triangular lattice. A final comparison of the cutoff properties of fibers characterized by a square lattice and a triangular lattice has been carried out.

Journal Article↗
PubMed2001

2-Arylpyrazolo[1,5-a]pyrimidin-3-yl acetamides. New potent and selective peripheral benzodiazepine receptor ligands.

A new class of N,N-diethyl-(2-arylpyrazolo[1,5-a]pyrimidin-3-yl)acetamides (3f-y), as azaisosters of Alpidem, was prepared following a novel synthetic method and their affinities for both the peripheral (PBR) and the central (CBR) benzodiazepine receptors were evaluated. Binding assays were carried out using both [3H]PK 11195 and [3H]Ro 5-4864 as radioligands for PBR, whereas [3H]Ro 15-1788 was used for CBR, in rat kidney and rat cortex, respectively. The tested compounds exhibited a broad range of binding affinities from as low as 0.76 nM to inactivity and most of them proved to be high selective ligands for PBR. The preliminary SAR studies suggested some of the structural features required for high affinity and selectivity; particularly the substituents on the pyrimidine moiety seemed to play an important role in PBR versus CBR selectivity. A subset of the highest affinity compounds was also tested for their ability to stimulate steroid biosynthesis in C6 glioma rat cells and some of these were found to increase pregnenolone formation with potency similar to Ro 5-4864 and PK 11195.

Acetamides↗
PubMed2000

Gene therapy of experimental brain tumors using neural progenitor cells.

Glioblastomas, the most frequent and malignant of primary brain tumors, have a very poor prognosis. Gene therapy of glioblastomas is limited by the short survival of viral vectors and by their difficulty in reaching glioblastoma cells infiltrating the brain parenchyma. Neural stem/progenitor cells can be engineered to produce therapeutic molecules and have the potential to overcome these limitations because they may travel along the white matter, like neoplastic cells, and engraft stably into the brain. Retrovirus-mediated transfer of the gene for interleukin-4 is an effective treatment for rat brain glioblastomas. Here, we transferred the gene for interleukin-4 into C57BL6J mouse primary neural progenitor cells and injected those cells into established syngeneic brain glioblastomas. This led to the survival of most tumor-bearing mice. We obtained similar results by implanting immortalized neural progenitor cells derived from Sprague-Dawley rats into C6 glioblastomas. We also documented by magnetic resonance imaging the progressive disappearance of large tumors, and detected 5-bromodeoxyuridine-labeled progenitor cells several weeks after the injection. These findings support a new approach for gene therapy of brain tumors, based on the grafting of neural stem cells producing therapeutic molecules.

Animals↗
PubMed2000

Three-dimensional finite-element beam propagation method: assessments and developments

In recent years the finite-element method (FEM) has been widely applied to three-dimensional beam propagation analysis, and several FEM propagators have been presented. Up to now, as far as we know, an exhaustive, deep, and comparative analysis of these formulations and of the related algorithms has never been presented. We critically analyze and numerically compare, to our knowledge for the first time, different vectorial, semivectorial, and scalar formulations in order to check their performances, point out weaknesses, and suggest future developments. The results obtained highlight once more the inadequacy of scalar approaches in dealing with actual photonics devices and suggest vector formulations worthy of further development and future research.

Journal Article↗
PubMed1999

Benzodiazepine receptor ligands. III. Synthesis and biological evaluation of 2- and/or 3-substituted pyrazolo[5,1-c][1,2,4]benzotriazine 5-oxides.

A new series of 2- and/or 3-substituted pyrazolo [5,1-c][benzotriazine 5-oxides and their 8-chloro derivatives were synthesized, and their benzodiazepine receptor (BZR) affinities were evaluated in vitro in comparison to lead compound 3-ethoxycarbonyl-8-chloropyrazolo[5,1-c][1,2,4]benzotriazine 5-oxide (29) [1,2]. None of the new compounds showed significant affinity for BZR. On the basis of a pharmacophore/receptor model suggested for lead compound 29, some hypotheses to explain the inactivity of new derivatives are discussed.

Animals↗
PubMed1999

Benzodiazepine receptor ligands. 4. Synthesis and pharmacological evaluation of 3-heteroaryl-8-chloropyrazolo[5,1-c][1,2,4] benzotriazine 5-oxides.

The synthesis of new 3-heteroaryl-8-chloropyrazolo[5,1-c][1,2, 4]benzotriazine 5-oxides and their binding activities at the central benzodiazepine receptor (BZR) are reported. The derivatives substituted at the 3-position with electron-rich five-membered rings, such as pyrrole 11, 2-thiophene 13c, or 3-thiophene 13d, showed good affinity values for BZR. In in vivo tests the 3-(thien-3-yl)-8-chloropyrazolo[5,1-c][1,2,4] benzotriazine 5-oxide (13d) showed selective anticonvulsant activity.

Animals↗
PubMed1998

Conservative surgical management of perforating Crohn's disease: side-to-side enteroenteric neoileocolic anastomosis: report of two cases.

Conservative surgical management of jejunoileal Crohn's disease is the first-choice treatment in plurioperated patients with high risk of small-bowel syndrome. Treatment is more controversial in patients with a limited disease and no previous surgery, especially in those with terminal ileitis. Even in those cases we advocate conservative surgical management because we have demonstrated regression of both symptoms and morphologic lesions. Contraindications to nonresectional surgery include the presence of abscesses and fistulas. Impending short-bowel syndrome represents a partial exception to this approach. In this article two cases of conservative surgery performed in plurioperated patients with perianastomotic perforating recurrent disease are presented. We have named this procedure "side-to-side enteroenteric neoileocolic anastomosis," which is a combination of small resections and conservative procedure. This operative strategy leads us to believe that nonresectional surgery could be selectively performed even in patients with perforating Crohn's disease.

Adult↗
PubMed1997

Duodenal involvement of Crohn's disease: three different clinicopathologic patterns.

PURPOSE: This study was designed to assess clinical and pathologic features of duodenal Crohn's disease (CD) and address its management according to different patterns of disease. METHODS: Twelve cases of duodenal involvement in CD are reported out of 336 patients treated between 1978 and 1993. They represent 3.6 percent of all cases. Three patients had a duodenal fistula, and nine had an intrinsic duodenal lesion. The duodenal fistula was in all cases a manifestation of recurrent CD involving an ileocolic anastomosis and the third portion of the duodenum. RESULTS: Treatment consisted of resection of the fistula's source and primary closure of duodenal breach. Of nine patients with intrinsic CD, five had stenosis and the remaining four had peptic ulcer-like lesions. Duodenal stenosis was treated with strictureplasty in three cases and duodenojejunostomy in two. No patient with ulcer-like lesions underwent surgery. CONCLUSIONS: Differences encountered in intrinsic duodenal lesions apparently reflect two different clinical patterns. Stenosis is not usually associated with multifocal disease and is often the first evidence of disease. Ulcer-like lesions are not specific; they do not evolve into stenosis as do ulcers in other sites of the disease, spontaneously disappear and relapse, and do not require surgery, except for complications. They are always associated with other locations of the disease.

Adult↗
PubMed1997

Conservative surgical management of terminal ileitis: side-to-side enterocolic anastomosis.

PURPOSE: Terminal ileitis is the most frequent presentation of Crohn's disease. Resection of the terminal ileum and cecum with ileocolic anastomosis has always been considered the "gold standard" in the surgical treatment of this condition. This study illustrates an alternative technique referred to as "side-to-side enterocolic anastomosis." METHODS: It consists of a longitudinal section of the terminal ileum starting 1 to 2 cm away from the beginning of the stricture and continued for a similar length on the ascending colon. A side-to-side anastomosis is then fashioned, in a kind of Finney-shaped strictureplasty. A series of five patients is reported. RESULTS: Average length of the anastomosis was 18.4 (range, 12-25) cm. Postoperative course was uneventful. Colonoscopy and large-bowel enema performed on some patients six months after surgery revealed a complete morphologic regression of the disease. All patients are presently in good condition, with no evidence of recurrence after an average follow-up of 8.9 (range, 6-15) months. CONCLUSIONS: "Side-to-side enterocolic anastomosis" can be a possible alternative option for the surgical management of Crohn's disease of the terminal ileum, providing at least regression of the morphologic aspects of the disease. Contraindications are presence of abscesses, fistulas, or rigid and fibrotic stricture. This technique can be considered a further example of nonresectional surgery such as strictureplasty. This makes it possible to conceive surgical treatment of Crohn's disease without resection in selected cases for the whole length of the small bowel and suggests the introduction of the new definition of "conservative surgical management of small-bowel Crohn's disease."

Adult↗
PubMed1997

Pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones. II. Synthesis and in vitro antimicrobial evaluation.

A series of Pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones (4a-p) was prepared by a simple synthetic procedure based on the reaction of hydroxylamine or methoxyamine with 2,3-substituted ethyl 7-dimethylaminovinyl pyrazolo[1,5-a]pyrimidin-6-carboxylates (3a-p). The antimicrobial activity of the obtained compounds was evaluated on a series of standard strains of Gram positive, Gram negative bacteria and fungi. None of the tested compounds showed significant activity.

Anti-Bacterial Agents↗
PubMed1996

Factors affecting recurrence in Crohn's disease. Results of a prospective audit.

It has been suggested that certain clinical and morphological features can modify the outcome of Crohn's disease, particularly regarding recurrence after surgery. A series of 233 patients was followed prospectively. They underwent a resectional surgical procedure for both primary and recurrent Crohn's disease during a fifteen-year period with a minimum follow-up of eighteen months. Possible risk factors for recurrence were studied. They included duration of disease before primary surgery, the type of clinical presentation at onset (whether "Perforating" or "Non-perforating"), the initial anatomical location, the presence of microscopic disease at the resection edges, the type of surgical procedure (anastomosis vs stoma), post-operative surgical complications and the age of the patient. The duration of the disease before the initial operation was the only significant factor related to the recurrence rate.

Adult↗
PubMed1996

Pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones. I. Synthesis and in vitro antimicrobial evaluation.

A series of pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones (9-36) was prepared by a simple synthetic procedure based on the reaction of ethyl 7-dimethylaminovinyl pyrazolo[1,5-a]pyrimidin-6-carboxylates (1-8) and reagents (a-n) containing a primary amino group. When this set of compounds was subjected to "in vitro" antimicrobial screening, it showed no significant activity.

Anti-Bacterial Agents↗
PubMed1995

New 2,3-substituted 4,7-dihydro-6-(1'H-pyrazol-3'-yl)pyrazolo[1,5-a] pyrimidin-7-ones and related compounds: synthesis and benzodiazepine receptor binding study.

The reaction between two series of 7-dimethylaminovinyl pyrazolo[1,5-a]pyrimidines 4(a-r) 7a, 7d, 7f, 7(h-j) and hydrazine in acetic acid is investigated. The structure of 4,7-dihydro-6-(1'H-pyrazol-3'-yl)pyrazolo[1,5-a]pyrimidin-7- ones 5(a-r) and 7-methyl-6-(1'H-pyrazol-3'-yl)pyrazolo[1,5-a]pyrimidines 8a, 8d, 8f, 8(h-j) are attributed to the isolated products and the pathway of this reaction is suggested. The in vitro benzodiazepine receptor (BzR) affinity of the title compounds are determined by testing their ability to displace 3H-flunitrazepam from its specific binding in bovine brain membranes. The IC50 and GABA (gamma-aminobutyric acid) ratio values give valuable indications about affinity and behavioural profile of these new BzR ligands. Included in this investigation are indicated several structure-affinity relationships of the title compounds.

Animals↗
PubMed1994

Functional outcome in handsewn versus stapled ileal pouch-anal anastomosis.

Eighty-eight of 119 patients who underwent ileal pouch-anal anastomosis for ulcerative colitis were evaluated. Forty patients had a handsewn anastomosis (Hs) with mucosectomy, and 48 had a stapled anastomosis (St). In each patient, we evaluated operative, morphologic, functional, and manometric features. The results in the Hs and St groups were similar when the anastomosis was within 1 cm of the dentate line. In particular, there was no correlation between the type of anastomosis and the number of bowel movements in a 24-hour period, the presence of the urge to defecate, and the use of antidiarrheal drugs. Leakage was significantly higher in the Hs group, even when the anastomosis was less than 1 cm from the dentate line. Pouchitis was more frequent in the Hs group, and, within this group, among those with a short distance between the anastomosis and the dentate line. No correlations were found between the presence of columnar epithelium or active colitis in the mucosa below the anastomosis, the functional outcomes, and the incidence of pouchitis.

Adenomatous Polyposis Coli↗